Yale Psychiatry Grand Rounds: "Harnessing Translational Approaches to Fight the Transgenerational Transmission of Stress"

Transcript

• 00:00John, for having me see, I I I did it.
• 00:04I didn't call you Doctor Crystal and
• 00:06Arena Esterlis for also reaching out,
• 00:08which I really appreciate it.
• 00:10I'll just share my slides.
• 00:13And so, you know,
• 00:16I I've come a long way for my PhD as,
• 00:19as you were introducing me,
• 00:20I was reflecting on my path.
• 00:21And I think one of my,
• 00:22one of my absolutely favorite
• 00:23parts of being a scientist is just
• 00:25going where the science takes you.
• 00:27And I think that's really
• 00:28a gift that we have,
• 00:29those of us who do research and
• 00:31our physicians as well as we just
• 00:33get to go where the science and
• 00:34our lived experience take us.
• 00:36So I'm very passionate about the field
• 00:38of reproductive psychiatry and I'm
• 00:40very passionate about helping women.
• 00:42Has the best way to help help babies, right?
• 00:44I appreciate all child psychiatrists,
• 00:46child adolescent psychiatrists.
• 00:48I I just really admire it.
• 00:50I found myself during my rotations,
• 00:52during not being able to
• 00:54compartmentalize the trauma of children.
• 00:56And I thought to myself the best way to
• 00:58help children is by helping their mothers.
• 00:59So that's really was the nice for my work.
• 01:01And so I'm really delighted to be
• 01:04talking to you today about the progress
• 01:06that we've made and I'm very pleased
• 01:07in fact that we've made some progress.
• 01:09So I'd like to start,
• 01:10I had the pleasure and honor of guest
• 01:13editing an issue of biological psychiatry.
• 01:15Thanks to John with Elaine Sao,
• 01:16who's a nationally recognized expert,
• 01:19really put the microbiome on the map
• 01:22for us in psychiatry on the exposome,
• 01:25the microbiome and psychiatric disorder.
• 01:27So this is a figure from our commentary.
• 01:30And when I really think about the exposome,
• 01:33I really think about all the things
• 01:35that you encounter from the womb to the
• 01:37grave that could impact your health.
• 01:39And we really see the microbiome
• 01:41as being a real, a real,
• 01:42a really key transducer of that stimuli.
• 01:44So illustrated here, we have diet,
• 01:46we have medication, we have pollution.
• 01:47And what I'm going to be focusing on
• 01:49for you today is stress and how we
• 01:51think of stress as part of the exposome.
• 01:53We all encounter,
• 01:55stress,
• 01:55everything from daily hassles to major life
• 01:58events to wars and things of that nature.
• 02:02And how can that impact us?
• 02:04And then how does that impact our health?
• 02:06And so I'd love to call all of your
• 02:08attention to the special issue,
• 02:10which really just has a number of wonderful
• 02:13contributions Internet from across the world,
• 02:15across the lifespan.
• 02:16Thinking about how they expose them
• 02:18really shapes our risk for psychiatric
• 02:20disorders or shapes the path that,
• 02:21you know, the contributes to the
• 02:24pathogenesis of psychiatric disorders.
• 02:25And so I think it's worth a download,
• 02:28worth a read,
• 02:28and I really encourage you to
• 02:30think about that.
• 02:31So as I said,
• 02:32I'll be focusing today on stress.
• 02:34So and specifically in pregnancy.
• 02:37So when we think about stress,
• 02:39what do we think about?
• 02:40Well, there's several layers to type,
• 02:42different types of stress,
• 02:43and I think it's important to think
• 02:44about each of these individually
• 02:45as well as collectively.
• 02:46So there's interpersonal stress.
• 02:48This is things like the amount
• 02:50of sleep you're able to get or
• 02:52if you have difficulty sleeping,
• 02:53whether or not you are getting
• 02:55a diet that's rich in fruits and
• 02:57vegetables and minerals and important
• 02:59fibers and things of that nature.
• 03:01Or whether you have a more deprived diet,
• 03:04interpersonal stressors,
• 03:05so your social relationships,
• 03:06your financial state,
• 03:08your your workplace or work stressors.
• 03:11And then there's structural
• 03:13and institutional things like
• 03:15racism can impact an individual.
• 03:18Things like climate change,
• 03:19pollution in the neighbourhood you live in,
• 03:22the built,
• 03:23you're built environment can all impact
• 03:25a pregnant person during pregnancy
• 03:26as well as the next generation.
• 03:29And So what I really started to
• 03:30think about and thinking about
• 03:31the special issue and just in
• 03:33general in my career is we can't.
• 03:34I can't fix all those things.
• 03:36We were talking before everyone
• 03:38came on about how it's going to
• 03:39be 60° today here in Columbus,
• 03:41OH, and I wasn't sure if that I
• 03:42was going to enjoy it,
• 03:43but I didn't know if that was a sign,
• 03:44a portent of our climate changing too much.
• 03:49But I can't change that.
• 03:50I do have started composting.
• 03:51I can't change that.
• 03:53But can I change personally,
• 03:54how these adverse exposures
• 03:56and their contribution,
• 03:57contribution to pathophysiology,
• 03:58Can I do anything to positively
• 04:01impact that in that space?
• 04:02If we can, as researchers,
• 04:04as scientists, as psychiatrists,
• 04:07psychologists,
• 04:08help the individual deal
• 04:10with the sequela of stress,
• 04:13Is that the best way of helping them?
• 04:15And I I happen to think so.
• 04:16Spoiler.
• 04:18And so when we think mechanistically about
• 04:21pregnancy and how prenatal stress is shaping
• 04:24the pregnancy and the next generation,
• 04:28why do we even think about it?
• 04:29Well, it used to be, though.
• 04:30It used to be thought, you know,
• 04:32women used to be told that pregnancy
• 04:34was just this time of elation.
• 04:35I guess we were thought to float
• 04:36around on these clouds of pink,
• 04:38you know,
• 04:38pink pheromones the entire time,
• 04:40blissfully awaiting our bundle of joy.
• 04:42But the the the case,
• 04:43it's not actually the case.
• 04:45There's actually women experience
• 04:46depression and anxiety at the
• 04:48same rate during pregnancy as
• 04:49they do outside of pregnancy.
• 04:51So up to 1/4 of women do experience either
• 04:54depression or anxiety during pregnancy.
• 04:56And I have some statistics for you here.
• 04:57So the reason we think about
• 05:00stress and sequela of stress,
• 05:01which is how as I conceive of
• 05:03depression and anxiety amidst
• 05:05those stress is a known trigger
• 05:07for many psychiatric disorders.
• 05:09Beyond depression and anxiety,
• 05:12we we it's important because it's
• 05:15relevant because there's prevalent
• 05:17and so that's why this is worth worth
• 05:19your time today with me this morning.
• 05:22You're going to encounter this at
• 05:23some point either in your personal
• 05:25or in your professional life,
• 05:26depending on your patient population.
• 05:29And so most of the focus until about
• 05:32a decade ago was on these mechanisms.
• 05:34Really stellar work from Tracy
• 05:36Bale and Petit Guadwa have really
• 05:38focused on epigenetic programming.
• 05:39So it's not just the genes you inherit,
• 05:41it's how they're expressed that can
• 05:42contribute to your risk of disease.
• 05:44So epigenetic modifications can go a
• 05:47long way to increasing or reducing your
• 05:50risk of what's in your genetic code.
• 05:53There's been a lot of focus
• 05:54on the immune function.
• 05:55So there's a broad epidemiological and
• 05:57clinical research that demonstrates
• 05:59that infection with the influenza
• 06:01during pregnancy is is known as is
• 06:03known to be associated with increased
• 06:05risk of developing schizophrenia
• 06:07in the offspring exposed to that.
• 06:09And there's other
• 06:12lines of evidence that also
• 06:14suggests that the immune system
• 06:15during pregnancy plays a key role
• 06:17in the transmission of stress.
• 06:19HPA access regulation.
• 06:20That makes sense, right?
• 06:22That changes in your HPA access
• 06:24work from Tim Oberland up in Canada
• 06:26has shown that the offspring
• 06:28born to women with depression
• 06:29or anxiety during pregnancy have
• 06:31dysregulation in their HPA access.
• 06:33Then about a decade ago,
• 06:34right as I was coming on the scene,
• 06:36there was some work.
• 06:38The new contender in this field is
• 06:40now the the gut brain axis is also
• 06:43thought to play a role in how prenatal
• 06:45stress might be underlying some
• 06:47of the mechanisms in transmission
• 06:48of stress to the next generation,
• 06:50which will be really the focus
• 06:52of my talk today.
• 06:53So when I first started
• 06:55giving talks in this space,
• 06:57I remember I was at SOBP one year.
• 06:59Someone asked me, you know,
• 07:01the brains all the way up here and you know,
• 07:03the guts all the way down here.
• 07:05How?
• 07:06How, You know what,
• 07:08how are the two connected?
• 07:09And so I spent a lot of time thinking
• 07:11about that and writing about that
• 07:13and making slides about that.
• 07:15So I'm going to explain that to you.
• 07:16So hopefully today you'll leave
• 07:18with a better understanding of
• 07:19how how that might be working.
• 07:20And so really it's a it's $1,000,000
• 07:23question or multi $1,000,000 question.
• 07:25How are peripheral changes in
• 07:27the microbiome And when I say
• 07:29microbiome with something no more,
• 07:31no less than all the collective
• 07:33community of microbes that are
• 07:34present in different orifices in
• 07:36your body and the gut microbiome
• 07:38specifically is thought to have an
• 07:40important role in your overall health.
• 07:43So our how are changes in your
• 07:45gut microbiome being transduced.
• 07:47And so we really think about in
• 07:49pregnancy three major ways that this
• 07:51is being transduced to the developing brain.
• 07:53And so this is an illustration
• 07:54from a review I wrote a few years
• 07:56back now with a very talented MD,
• 07:57PhD student in my lab,
• 07:59which we'll be hearing more about.
• 08:01So the three major ways are
• 08:03through the first of all,
• 08:04it's thought that stress is shifting
• 08:06the microbes and I'll just like
• 08:07to illustrate this in a moment.
• 08:09The three major ways is that
• 08:11through vertical transmission.
• 08:12So at delivery,
• 08:13not to be too graphic before lunch,
• 08:15but during delivery the mother
• 08:17bequeaths her microbiome to the infant
• 08:19through a standard vaginal delivery
• 08:21or through C-section is one way
• 08:23that it's thought to shape the the
• 08:24governing axis of the next generation.
• 08:26The 2nd way is through
• 08:28modulation of the immune system,
• 08:30because microbes at the end of
• 08:32the day are microbes and they
• 08:33elicit an immune response.
• 08:35And then through the metabolites,
• 08:36they're not just sitting there
• 08:38quietly twiddling their thumbs,
• 08:39they're actually producing
• 08:40really bio active metabolites,
• 08:43and I'll be talking more about that as well.
• 08:46So to illustrate for you this even further,
• 08:48we have here a pregnant person
• 08:50and they're undergoing stress.
• 08:52What happens next is that there's
• 08:55activation of the HPA axis, release of ACTH,
• 08:58release of glucocorticoids from
• 08:59the adrenals as well as sympathetic
• 09:02nervous system activation.
• 09:04How this impacts the host,
• 09:06which is the pregnant person
• 09:08in this illustration is it can
• 09:10modulate their immune system.
• 09:12So lead to the recruitment of immune cells
• 09:15and the activation of immune cells to trans.
• 09:20You've raised something called cytokines
• 09:21which if there's any immunologists,
• 09:22I apologize in the audience,
• 09:24but I I sometimes think of cytokines as
• 09:27the neurotransmitter of the immune system.
• 09:28So these can travel and recruit
• 09:31additional immune cells and cytokines
• 09:32themselves can have impact on neurons
• 09:35and other and other cells in your brain.
• 09:39And then it also all these together,
• 09:41both the immune system activation
• 09:43as well the sympathetic nervous
• 09:45system activation has an effect
• 09:47on the intestinal epithelium.
• 09:48And so the impact on the intestinal
• 09:50epithelium can also give rise to and it
• 09:53can also separately impact the microbes.
• 09:54So the idea is that during stress,
• 09:56there's a shift from 1 homeostatic
• 09:58population of microbes.
• 10:00There's dysbiosis.
• 10:01So it gives rise to a shift in the community
• 10:04of microbes that are present in your gut.
• 10:07And why is this important?
• 10:08Well, for a few reasons.
• 10:09One, as I mentioned, they're not just
• 10:11sitting there twiddling their thumbs.
• 10:12They're making metabolites.
• 10:13If there's anyone in the audience
• 10:14that wants to guess.
• 10:15But these are.
• 10:16These are two of my favorite metabolites.
• 10:18This is I guess actually
• 10:19you you you can't unmute,
• 10:21it's actually serotonin and butyrate
• 10:23which butyrate for those of you
• 10:26interested in epigenetics is a very
• 10:28important epigenetic modifier and
• 10:30serotonin we all we all know and
• 10:32love and so they're actually major
• 10:35metabolizers of tryptophan and
• 10:36producers of short chain fatty acids.
• 10:39So it's incredibly important These
• 10:41together can have an immunomodulatory impact,
• 10:43these metabolites as well as well as
• 10:47at delivery the baby is going to be
• 10:51seated as I mentioned by the mother.
• 10:52So this sets up the next generation's
• 10:54got brain access in a way that
• 10:57could be maladaptive.
• 10:58And then why we worry about
• 11:00that is because Mycoglia,
• 11:01which are the innate immune
• 11:03cells of your brain,
• 11:05are increasingly understood to
• 11:07have an incredibly important role
• 11:10in psychiatric disorders like
• 11:11anxiety and depression.
• 11:13So a shift in microglia,
• 11:14both in terms of their population
• 11:16as well as their level of activity
• 11:19could understandably contribute to the
• 11:20emergence of psychiatric disorders.
• 11:22So this is sort of the 1000 foot
• 11:24view or 10,000 foot view of what
• 11:27I'll be speaking to you about today.
• 11:28And I really just wanted to give you
• 11:30a framework in which to put all the
• 11:31data I'm about to present to you.
• 11:32So this is sort of how I conceive
• 11:35of the gut brain access during
• 11:36pregnancy and how it might be
• 11:39impacting the developing brain.
• 11:41So one of the wonderful things
• 11:42about working with rodents,
• 11:44and this is an illustration
• 11:46from the special issue that I
• 11:48co-authored with Mary Kimmel,
• 11:49a close friend and colleague
• 11:50at the University of North
• 11:51Carolina, Chapel Hill,
• 11:52is that we can test some of these things.
• 11:54You know, human pregnancies
• 11:55take nine months, give or take.
• 11:57Mouse pregnancies or 21 days, give or take.
• 11:59And we can mechanistically get AT and
• 12:01over using a variety of tools that
• 12:02I'll be showing you today some of these
• 12:04bigger questions on a micro scale.
• 12:06And so this if you're interested
• 12:08in reading more about this,
• 12:10please go ahead and look at this review.
• 12:11But what I wanted to highlight for
• 12:13you now is that I'm really going to
• 12:15be focusing on this shift in maternal
• 12:17gut microbes as well as the upper
• 12:19left hand portion of this figure,
• 12:21which is the cytokine production.
• 12:24CCL 2 which is a chemokine that recruits
• 12:26immune cells to the site of injury
• 12:28like a cut or is also been shown by
• 12:30work from a colleague here Jonathan
• 12:32Godbout to be really important in
• 12:34increasing anxiety following a stressor.
• 12:38So within the absence of CCL 2,
• 12:40I work from Godbout's lab and
• 12:42Michael Bailey's labs and others have
• 12:43shown that you no longer see the
• 12:45emergence of anxiety like behaviour
• 12:47after a social defeat stress.
• 12:48So it's it's a critically
• 12:50important chemokine.
• 12:51So I just wanted to give you the,
• 12:53the,
• 12:53the basic framework and the
• 12:55clinical framework for what what
• 12:57we'll be talking about today.
• 12:59So how again we can model this in mice.
• 13:01And one of the reasons that I became
• 13:03so interested in this field is
• 13:05because I saw the high translational
• 13:07nature of the microbiome.
• 13:08I saw that it was both in in mouse
• 13:10and man or woman in this case.
• 13:12And so I really thought that we could really,
• 13:15I could really advance the advance
• 13:16the field in a way that was unique
• 13:19because there there are limits,
• 13:21translatability.
• 13:21And so I was really drawn to the
• 13:23microbiome for a variety of reasons,
• 13:25but that was one of them.
• 13:26So how do we model this in mice?
• 13:29And I'm just going to have to move
• 13:31my little zoom bar here so that
• 13:32I can see my slide.
• 13:34This is how we we model it.
• 13:35So in our lab,
• 13:36we do a restraint stress,
• 13:37which is not that mice are placed
• 13:40in conical tubes with air holes for
• 13:42two hours a day between gestational
• 13:44day 10 and gestational day 16,
• 13:45which you can see here is roughly
• 13:47correlated to the second trimester in humans,
• 13:48which has been shown in a variety of
• 13:51epidemiological and clinical studies
• 13:52to be critically important for
• 13:54neurodevelopment and increasing risk
• 13:56of psychiatric disorders in terms of stress.
• 13:59And then one cohort of mice is a
• 14:01sacrifice at gestational day 17.
• 14:03Another cohort is allowed to go through
• 14:04parturition and an age into adulthood.
• 14:06We don't have a second hit in this model.
• 14:09It's just the only stressor they
• 14:11experience is in utero and then we
• 14:13do behavioral testing in adulthood.
• 14:14You can see that a few things to
• 14:16point out is that mouse pregnancy
• 14:18is besides the duration
• 14:19of pregnancy has other differences.
• 14:22So in in mice and I'll be showing
• 14:24you a video in a little bit,
• 14:26there's it's like a Pearl necklace
• 14:27or like a necklace like the one
• 14:29I'm wearing where each mouse,
• 14:30each fetus is individually housed with
• 14:33a placenta and its own amniotic SAC
• 14:35and and there's litter sizes between
• 14:378:00 and 10:00 are quite normal.
• 14:39Whereas obviously in humans
• 14:41Singleton pregnancies are the norm.
• 14:42Though of course there's you know
• 14:44twins and triplets out there and more.
• 14:46There's just several structural
• 14:48differences between the placenta as well
• 14:50and so there's absolutely differences.
• 14:53And another important difference to
• 14:54point out to you is that a lot of
• 14:57neurodevelopment occurs X utero in mice.
• 14:59So at post Natal day one that's roughly
• 15:01equivalent to the third trimester.
• 15:03So mice of course are not little people,
• 15:05but we can draw some mechanistic
• 15:08conclusions nevertheless from this model.
• 15:11So what we found,
• 15:12I'll tackle a few of the a few of the
• 15:16findings in rapid succession so that
• 15:18I can try to walk you through what
• 15:20I believe is the most exciting part,
• 15:22which is the translate translational
• 15:24nature of this research.
• 15:25But I'm happy to answer questions
• 15:27afterwards in the Q&A.
• 15:29So the first thing that was important
• 15:31to establish in this model was
• 15:33does this stress actually change?
• 15:34Does it actually lead to dysbiosis,
• 15:36a change in the microbes?
• 15:38And the answer, the short answer is yes.
• 15:39So what I see here on the left
• 15:41is the is the dam,
• 15:43which is what we call mouse moms.
• 15:45And this is PCOA plot.
• 15:47So this is no more,
• 15:47no less than the entire genome,
• 15:49microbiome genome of a specific mouse.
• 15:52So each dot represents the grand
• 15:54sum total of the genes expressed
• 15:56in the microbes of the mom.
• 15:58And this is taken on day 17 of gestation.
• 16:03So after the stressor is completed
• 16:05and what you can see here is that
• 16:07there's a significant effect of stress.
• 16:09So red is stress, blue is control,
• 16:11and there's a shift in the microbiome
• 16:13of the dams that were exposed to
• 16:15prenatal stress and those that weren't.
• 16:17Next,
• 16:17I'll turn your attention to male
• 16:19and female offspring.
• 16:21And what you can see is, again,
• 16:22blue is control, red is stress.
• 16:24There's a significant shift in adulthood.
• 16:27So these samples were taken in adulthood.
• 16:30So even though they were never
• 16:31stressed again,
• 16:32just the fact that they were
• 16:33exposed to stress in utero gave
• 16:35them a significantly different
• 16:37microbiome into adulthood.
• 16:38So it really does look like the gut.
• 16:40Brain access was shifted in these
• 16:42offspring who are exposed to
• 16:43prenatal stress and the citations
• 16:45are in the bottom right hand corner.
• 16:47In case you're interested in
• 16:49reading more next I'm turning my
• 16:51attention to adulthood.
• 16:52In the interest of time I'm just going
• 16:53to show you social behaviour today,
• 16:54but we have found increased in
• 16:57increased anxiety like behaviour in
• 16:58female and changes in cognitive tasks
• 17:00as well in the female offspring.
• 17:02This changes in social behaviours were
• 17:04found in both male and females and we've
• 17:06now replicated and extended these findings.
• 17:08But for the purpose of today,
• 17:10for those of you that might not have
• 17:11had the pleasure of doing mouse
• 17:12behaviour during your training,
• 17:13I thought I would share a video.
• 17:15So this is a social approach paradigm.
• 17:18It's the three chamber social behaviour test.
• 17:19So in one of these little
• 17:21chambers this is a mouse.
• 17:22I'm blinded so I do not know if this
• 17:24mouse was exposed to stress or not,
• 17:26but it can either choose to investigate.
• 17:28In this little cage is either a mouse or,
• 17:31and in this little cage is an object,
• 17:33and we simply measure the amount of
• 17:36time prefers to spend approaching a
• 17:38it's a mouse from a very docile mouse.
• 17:40Strain a DBA mouse and of the same
• 17:44sex as the test mouse and it's able to
• 17:46poke its little nose between the bars.
• 17:49But it's not able to engage in aggressive
• 17:51or sexual behavior with a mouse or an object.
• 17:54And what you can see here is that
• 17:56I'm showing this is a heat map of
• 17:58where it chooses to spend time.
• 17:59So what you can see is that there
• 18:01was a significant reduction and
• 18:03now we've extended this to other
• 18:04social paradigms as well.
• 18:05There's a significant reduction in the
• 18:08social behaviour demonstrated by both
• 18:10male and female offspring exposed to
• 18:12prenatal stress compared to the control mice.
• 18:15And so this showed us that yes,
• 18:17so check there's changes in the microbiome,
• 18:20check there's changes in
• 18:22behaviours in adulthood.
• 18:23And the next thing we wanted to
• 18:24examine was that whether or not there
• 18:26was changes in neuroinflammation.
• 18:27So we did this in a number of ways.
• 18:29So I'm showing two of them here.
• 18:31We've done this now with full cytometry,
• 18:33immunohistochemistry as well
• 18:35as gene expression.
• 18:37And I if you invite me back in a few years,
• 18:39we currently are working on our single
• 18:40cell RNA seek data and we're finding some
• 18:42very exciting changes there as well.
• 18:44So we've now interrogated this
• 18:46in several different ways.
• 18:47What I'm showing you here is that
• 18:49there's a significant increase here
• 18:50on the left side in fetal brain
• 18:52gene expression of Illinois 6,
• 18:53which is a key cytokine that's
• 18:55been implicated in a variety of
• 18:57psychiatric disorders,
• 18:58including anxiety and depression.
• 18:59So this is in fetal brain and
• 19:01embryonic day 17 and then half.
• 19:03There's also a significant
• 19:04increase in TNF alpha.
• 19:06Next,
• 19:06we did immuno labeling for IBA one,
• 19:09which is a marker for microglia.
• 19:12And what we found was a significant increase
• 19:15in IBA one staining in the prefrontal cortex
• 19:18in mice taken from stress pregnancies.
• 19:22And compared to controls,
• 19:23we also looked as a control region in
• 19:25the motor cortex where we did not have
• 19:27an A priori hypothesis that we would
• 19:28see a change in neuro inflammation
• 19:30or in microglia labeling there.
• 19:32And in fact,
• 19:33we did not see an
• 19:34an increase there.
• 19:35So this isn't just global neuro inflammation,
• 19:37it's specific to brain regions
• 19:39that are implicated in behavior.
• 19:41And we also saw an increase in loops,
• 19:42IL 1 beta in that in the prefrontal cortex as
• 19:45well as Illinois 6 and this is an adulthood.
• 19:48So on the left side of the slide
• 19:49we have embryonic offspring.
• 19:50And what I'm showing you here on the right
• 19:52is that this continues into adulthood.
• 19:54So the microbiome changes
• 19:55continue into adulthood,
• 19:56the behavioural changes
• 19:57continue into adulthood,
• 19:59and neuro inflammation continue
• 20:01into adulthood as well.
• 20:03So as I mentioned,
• 20:05CCL 2 is an important chemokine
• 20:07that recruits immune cells to a
• 20:09site of injury or to or and also
• 20:12increases in response to stress.
• 20:14And So what we hypothesized was that,
• 20:16and it has been shown to be
• 20:18required for behavioural changes
• 20:19following a social defeat stressor.
• 20:21So then we simply set to set up,
• 20:22we simply set out to test whether
• 20:24or not CCL 2 was required for
• 20:27the behavioural changes and the
• 20:29inflammatory changes that we
• 20:31saw following period of stress.
• 20:33So to do that we took CCL 2 knockout mice,
• 20:35which are commercially available and
• 20:37constitutively have CCL 2 knocked out.
• 20:39And we put them through the same stress
• 20:42paradigm that I showed you earlier
• 20:44with the regular wild type mice.
• 20:46And the first thing we found was
• 20:47that there was no longer that
• 20:49increase in Illinois six in the
• 20:50fetal brains or the increase in
• 20:52TNF alpha in those fetal brains.
• 20:54And when we looked at behaviour,
• 20:55we no longer saw a significant reduction
• 20:58in social behaviour in the adult
• 21:01offspring following prenatal stress,
• 21:03which was very different than what we
• 21:05had seen in the wild type medicine
• 21:07that came out during the pandemic
• 21:09and translational psychiatry.
• 21:12So then Helen, my very talented MD,
• 21:14PhD student that I've mentioned
• 21:16who's going to match in the
• 21:18next month in Pediatrics,
• 21:19didn't succeed in recruiting
• 21:20her into psychiatry.
• 21:21But that's OK.
• 21:22She'll be a phenomenal pediatrician and she's
• 21:24still interested in the developing brain.
• 21:25So I'll consider that a win.
• 21:27I wanted to ask a daring question,
• 21:29which is whether or not an increase
• 21:31in fetal CCL 2 would be sufficient.
• 21:33So it's required, but is it sufficient
• 21:36to induce the changes that we saw?
• 21:38So how was she going to do that?
• 21:41Well, she decided.
• 21:44We decided that she would
• 21:47inject intraemniotic CCL 2,
• 21:49recombinant CCL 2,
• 21:50mouse CCL 2,
• 21:51or saline on embryonic day 16 1/2.
• 21:54She did a whole bunch of
• 21:56experiments leading up to this.
• 21:57Wish I'll spare you a time course.
• 21:59And we found that CCL 2 peaked on day 16.5,
• 22:02and so she wanted to emulate that
• 22:05with a injection of recombinant
• 22:07CCL 2 on embryonic day 16.5.
• 22:10And I'll show you a video in a moment
• 22:12to show you exactly how she did that.
• 22:14And then one cohort.
• 22:15And then she sewed the mice back up again.
• 22:17They recovered nicely from
• 22:18anaesthesia and from the surgery or.
• 22:20And then we one cohort we collected samples
• 22:23on embryonic day 17 1/2 and the other
• 22:26went through parturition, no problem.
• 22:28And then we looked at behaviour in adulthood.
• 22:31So for any of you who are squeamish,
• 22:32you might just want to look away
• 22:34for the next 1015 seconds or so,
• 22:36because what I'm going to show
• 22:38you is her surgery.
• 22:39So she would anesthetize the mice,
• 22:42do an incision remove.
• 22:43You can see this Pearl necklace,
• 22:45as I mentioned, of all the different fetus
• 22:47individually housed in their amniotic sacs.
• 22:49And this is her very gently
• 22:51and capably doing an injection.
• 22:52So you can see she holds it
• 22:54carefully with the tweezers.
• 22:55This has been labeled with dye so
• 22:56that you can see it and it's going.
• 22:58It's basically you could see
• 22:59the dye migrating from one side
• 23:04all the way through the other,
• 23:07so following and here it's coming
• 23:09all the way back through so and then
• 23:13after that she carefully taps it.
• 23:15There's no blood and we
• 23:17continue on with our day.
• 23:18So if you were looking away,
• 23:19you can look again.
• 23:21The exposed mouse fetuses are no
• 23:24no longer on screen and so we
• 23:25were very excited to have this
• 23:27work come out a couple months
• 23:29back in behavioural beta immunity,
• 23:31which is a leading journal in the
• 23:34field of psycho neuro immunology.
• 23:36And what we found is first all
• 23:38direct your attention here to
• 23:39the middle amniotic fluid.
• 23:40So we were thankful to see that
• 23:42there was a significant increase
• 23:43in CCL 2 in the amniotic fluid.
• 23:46So she successfully injected them.
• 23:48And then I think it's really interesting
• 23:50to note here on the left hand side
• 23:51that it stayed in the fetal compartment.
• 23:53There was no travelling of this
• 23:55protein into the maternal compartment.
• 23:57So we looked both at the plasma There,
• 23:59we looked at the maternal plasma.
• 24:01There was no,
• 24:01there was no change in CCL 2.
• 24:03And then we looked at the placenta.
• 24:05There was no increase in CCL 2.
• 24:07So this was really contained
• 24:08in the fetal compartment.
• 24:09When we looked at the fetal plasma,
• 24:10we saw a significant increase in CCL 2.
• 24:13We looked at the fetal liver,
• 24:14which we've identified as being
• 24:16an important source of CCL 2.
• 24:18I didn't have time to show you that
• 24:19data I originally thought and we
• 24:20spent about five years in the lab.
• 24:22So any new PIS out there don't feel bad.
• 24:23In my lab spent about five years worth
• 24:26of money trying to prove that those
• 24:28CCL 2 is coming from the placenta.
• 24:29But in fact it's not.
• 24:30It's actually coming from the fetal liver,
• 24:31which is fascinating.
• 24:32I don't have time to get into today,
• 24:35but it was up in the fetal liver
• 24:37when we looked at the fetal brain.
• 24:38It was also significantly increased and
• 24:41finally in so in terms of the behavior,
• 24:44so in what you see here on the left
• 24:46side side of the part of this graph
• 24:48in green circle of social squares
• 24:51object with a saline injection,
• 24:53there's a significant in the
• 24:55significant preference for engaging
• 24:56with a social con specific.
• 24:59Whereas with the CCL 2 mice they no
• 25:01longer had preference for social interaction.
• 25:03So there is a reduction in social
• 25:05behaviors with just this intra
• 25:07amniotic injection of CCL 2,
• 25:09which I really believe confirms our
• 25:12our belief or confirms our hypothesis
• 25:15that CCL 2 is integral to the it's an
• 25:18integral part of how prenatal stress
• 25:20is transmitting these behavioral
• 25:22changes to the next generation.
• 25:25So next I really struggled,
• 25:27or not.
• 25:28Next,
• 25:28this entire time I was really struggling
• 25:30with a question of does this translate.
• 25:33I'll never forget in medical school
• 25:35during my OBGYN rotation that the
• 25:37big paper came out suggesting that
• 25:39hormonal replacement therapy was
• 25:42potentially not advantageous for women.
• 25:45And so that a lot of the literature
• 25:46that had
• 25:47supported the use of and of course
• 25:49the pendulum has swung wildly back
• 25:50and forth a few times since then.
• 25:52But a lot of the literature at the
• 25:54time had been the world at work
• 25:56suggesting that hormone replacement
• 25:57therapy was very important.
• 25:58So I remember as a medical student thinking,
• 26:00I don't want that.
• 26:01I don't want to spend decades of my
• 26:03life doing something in mice and then
• 26:05bring it to clinic and find out that
• 26:07it's completely irrelevant in humans.
• 26:09And so we thought of a lot of
• 26:11different ways in lab to figure
• 26:13out whether or not it translated.
• 26:15And so we simultaneously collaborated with
• 26:18a group at UCLA who had an funded RO one.
• 26:22And we also launched our
• 26:23own clinical studies.
• 26:24So I'll be sharing, sharing data from both.
• 26:26So this is first of all,
• 26:27a graph of maternal health.
• 26:28So this is where I'm sitting right now,
• 26:30right in the middle of Ohio.
• 26:31So my kids like to say 4
• 26:33hours from anything good.
• 26:34No offense to Ohio, but right smack
• 26:36in the middle in Franklin County,
• 26:38Ohio and a priority here.
• 26:40Unfortunately,
• 26:40Ohio is right behind Mississippi in
• 26:43terms of morbidity and mortality during
• 26:46pregnancy and especially this is of
• 26:48concern in the African American community.
• 26:50So it's a major issue here in
• 26:52Franklin County and in fact,
• 26:53depression is a major issue
• 26:54here in Franklin County as well.
• 26:56And you can see that almost 20%
• 26:58of women here have a diagnosis of
• 27:00depression during pregnancy in 2022.
• 27:02So it's a met.
• 27:04Postpartum depression or prenatal
• 27:05depression is considered a many issue in
• 27:08many communities here in Franklin County.
• 27:10And also there's a major issue,
• 27:12as I mentioned,
• 27:13with morbidity and mortality
• 27:14during pregnancy.
• 27:14So preterm birth is a negative sequela
• 27:18of having depression or significant
• 27:20depression or anxiety during pregnancy.
• 27:22And there's other
• 27:23contributing factors to that.
• 27:24And the low birth weight or intriguing
• 27:26growth restriction is a major issue as well.
• 27:28So this is unfortunately a good
• 27:30place to study some of these,
• 27:32some of the issues that
• 27:33we're concerned about.
• 27:35And in addition,
• 27:37COVID-19 absolutely impacted
• 27:38the population here as it did
• 27:40I think throughout the world.
• 27:41And there was just a lot of restrictions
• 27:43here on who you could bring to delivery
• 27:46and a variety of other restrictions
• 27:48during pregnancies that really
• 27:50aggravated and stressed our patients.
• 27:52And so we conceived of much of the work
• 27:55to date in the field of the microbiome
• 27:58in pregnancy had one time point,
• 28:00so the second trimester or the 3rd trimester.
• 28:02And what I had grown to appreciate was that
• 28:05it was really the longitudinal changes
• 28:07in the microbiome that could be important.
• 28:09And so we set out to do a
• 28:11longitudinal study of the microbiome
• 28:13through pregnancy and delivery.
• 28:15You can see the inclusion criteria on the
• 28:17left and our exclusion criteria on the right.
• 28:19When we collected,
• 28:20we enrolled.
• 28:21So this started many years ago now I think in
• 28:252019, so before the
• 28:27pandemic at two locations.
• 28:28So the Campbell Hall here
• 28:29on the left is the rest,
• 28:30the OBGYN resident clinic.
• 28:32So these are underinsured patients,
• 28:35insured but underinsured
• 28:36members of the community.
• 28:38And then the member of the picture
• 28:39on the right is on the Kenny Road.
• 28:41One of the faculty practices
• 28:42which tends to be OU insurance
• 28:45or well insured patients,
• 28:47was on the right.
• 28:48And I have to take the moment to
• 28:50thank Teresa Teresa Regisigura,
• 28:51who started in my lab as an undergraduate
• 28:53and is now completing a short postdoc
• 28:55in my lab as she applies for postdocs.
• 28:57If anyone on the call is interested in a
• 28:59really talented postdoctoral researcher,
• 29:01let me know.
• 29:03She's interested in going to the East Coast.
• 29:05And then the person on the right
• 29:06is my my wonderful husband,
• 29:08who is the world's tallest
• 29:10gynecologist at six foot 10,
• 29:11but also a really hard worker and
• 29:14collected all of these samples by hand,
• 29:16as it were that I'm about to show you.
• 29:18And so he was the faculty member at
• 29:20the practice that was collecting and
• 29:22he also overseas the resident clinic.
• 29:23So he was collecting samples at both places,
• 29:25which gave us a really cleanly
• 29:28gathered sample set to my my
• 29:32my deep gratitude for them.
• 29:35So what?
• 29:35I just want to shift your attention
• 29:36and give you some background about
• 29:38the human maternal microbiome.
• 29:39So I've shown you some data from mice.
• 29:41But just speaking in,
• 29:42in generalities, in terms of the gut,
• 29:44greater diversity is generally
• 29:47seen as beneficial.
• 29:49And a lot of this work, however,
• 29:50has come from C Clostridium difficile,
• 29:53which is a terrible, terrible once,
• 29:55if you ever encountered it clinically,
• 29:56you'll never forget it.
• 29:57Terrible, terrible form of diarrhoea.
• 30:00And so C diff happens when a
• 30:02patient has been treated with
• 30:03antibiotics in the hospital.
• 30:05So what we know about diversity in
• 30:07the gut is actually somewhat flawed
• 30:09in the sense that a lot of the
• 30:10literature comes from antibiotic use
• 30:12and that's not exactly what we're
• 30:14seeing necessarily out in the community.
• 30:16But in general,
• 30:16a greater diversity is seen as being
• 30:19beneficial and there's also known
• 30:20to be shifts in composition across
• 30:23pregnancy under normal conditions,
• 30:24under normal pregnancy conditions.
• 30:26And I have some citations for
• 30:27you in the bottom right there.
• 30:29When we turn our attention
• 30:31to the vaginal microbiome,
• 30:32diversity is actually decreased
• 30:34about across pregnancy and a
• 30:36more diverse vaginal microbiome
• 30:38community can actually increase
• 30:40risk of adverse OB outcomes.
• 30:42So less diversity in the
• 30:44vaginal microbiome community.
• 30:45So just there's a lot of Lactobacillus
• 30:47in the vaginal community and
• 30:49that's seen as beneficial.
• 30:51So there's a difference
• 30:52already between the gut and the
• 30:54vaginal microbiome community.
• 30:56But what we were trying to ask is
• 30:58how does stress impact this and
• 30:59really does it impact both the
• 31:01gut and the vaginal community?
• 31:03And how might this be impacting
• 31:06the community that the infant
• 31:07is exposed to at our
• 31:08tradition And unfortunately we did not
• 31:10have because of the pandemic coming in
• 31:11the midst of the study we did, we had.
• 31:13So I won't be able to answer
• 31:15for you today with this study.
• 31:16What's going on in the infant
• 31:17though we do have a collaboration,
• 31:18so I'll be able to give you some
• 31:20insight about the impact on the infant.
• 31:22So this is again our study design.
• 31:23We what we lacked for in sample size,
• 31:26we tried to make up for in again this
• 31:28is a pilot study we made-up for in the
• 31:30longitudinal nature of this study.
• 31:31So first, second, third,
• 31:33trimester delivery and nest,
• 31:34if when possible, postpartum visits.
• 31:37So the these are the study visits,
• 31:38these are the psychometric scales
• 31:40we obtained and these are the
• 31:41biospecimens that we obtained at these.
• 31:43And so we've got both rectal
• 31:45and vaginal swabs.
• 31:45Microbiome can be collected
• 31:47in all sorts of ways.
• 31:49Many studies use at home kits.
• 31:51I had some concerns about that
• 31:53for a variety of reasons I'm
• 31:54happy to get into in AQ and A.
• 31:55And so we just decided that my
• 31:57husband would have to collect all
• 31:58the samples and that worked out
• 32:00just fine for this pilot study
• 32:01and he did the rectal and vaginal
• 32:03swabs himself and then we obtained
• 32:05maternal blood and umbilical
• 32:07cord blood as demonstrated here.
• 32:09And so just for a moment about
• 32:11our sample demographics,
• 32:11we are very pleased There's been a
• 32:14historical exclusion of people of
• 32:15color from biomedical research and
• 32:17we were very pleased that we were
• 32:19able to recruit and study non weight
• 32:22individuals as well as reflected here.
• 32:24And you can see overall as I
• 32:25mentioned into the pilot study.
• 32:26So we have a small number of people,
• 32:28but the fact that we're able
• 32:29to get a signal from that,
• 32:30as I'll show you shortly,
• 32:32was we're still able to get a
• 32:34signal from even a small sample size
• 32:37suggesting that we are on to something.
• 32:39So we got stress scores and
• 32:42depression scores.
• 32:42And what you can see here is this
• 32:44is the scale of PSS and CSD.
• 32:46If you're not familiar with them,
• 32:48low is 0 to 13.
• 32:49So these were not,
• 32:52they were not clinically
• 32:54depressed individuals in general.
• 32:57So this is just all
• 32:59comers to an OBGYN clinic.
• 33:00These were not psychiatric
• 33:01patients coming to for psychiatric
• 33:03care or psychological care.
• 33:05So we really were setting out to ask
• 33:07if stress and depressive symptoms
• 33:08are associated with differential
• 33:10abundance of specific maternal
• 33:12microbial taxes or specific microbes.
• 33:15And So what we found is that there was
• 33:18in the third trimester Lactobacillus
• 33:20specifically Lactobacillus einers
• 33:23was significantly shifted with
• 33:26with stress and this was actually
• 33:28contrary to general expectation.
• 33:30They're generally thought to be beneficial.
• 33:32So this we were intrigued to see
• 33:34this and we also found that these
• 33:36are also known to be a dominant
• 33:38tax of the vaginal community
• 33:39especially during pregnancy.
• 33:40So as I mentioned Lactobacillus
• 33:43is a major vaginal microbe.
• 33:45And so one of the ways that preterm
• 33:47birth is thought of just in the
• 33:50obstetrical community is that
• 33:52others maturation is happens more
• 33:54rapidly both in the brain and
• 33:56the lungs and potentially what
• 33:57we're seeing here in the in the in
• 34:01the vaginal and gut microbiome.
• 34:03And so the idea is that preterm birth
• 34:06happens for for still unknown reasons,
• 34:08but part of what's seen in preterm
• 34:10birth is that the fetus and the the
• 34:14maternal pregnancy mature more rapidly.
• 34:16So is that in fact,
• 34:17maybe what we're seeing here is that
• 34:19there's an earlier migration of
• 34:21vaginal microbes to the gut microbiomes.
• 34:22That's that's something we're
• 34:24interested at in pursuing.
• 34:25At delivery,
• 34:26we saw a significant increase
• 34:28in these microbes,
• 34:29which are in fact pathogenic and
• 34:32associated with gestational complications
• 34:34as well as intrauterine inflammation.
• 34:36So we were interested to see a
• 34:39significant increase of those with
• 34:41stress at delivery and Gardinella is
• 34:44also associated with complications
• 34:47and we were also interested in to see
• 34:49an increase in Gardinella Gardinarella.
• 34:51Next,
• 34:52when we turn our attention to the plasma
• 34:56CCL 2 that the chemokine that I kept
• 34:58talking about in my mouse studies,
• 35:00we actually did a panel for a
• 35:02variety of inflammatory factors,
• 35:04some of which I'm showing you here.
• 35:05And yet CCL 2 emerged as being
• 35:09associated with stress and depressive
• 35:11symptoms in the third trimester.
• 35:12So I was very fascinated to see
• 35:15that this chemokine that plays such
• 35:17an important role in rodent models
• 35:19of stress was also here in humans.
• 35:21So it was associated with
• 35:23significant increases.
• 35:24So this is maternal plasma
• 35:27in the third trimester.
• 35:29So just to summarize,
• 35:30what I'm showing you so far is
• 35:31that an increase in stress and
• 35:33depressive scores was associated
• 35:34with an increase in maternal CCL 2.
• 35:36Next,
• 35:37when we looked at CCL 2 and its
• 35:39relationship to Lactobacillus,
• 35:41we were very heartened to see that
• 35:43there was a a relationship between these two.
• 35:46So in an extended previous findings
• 35:48that Lactobacilli are found in
• 35:50greater abundance and infants
• 35:51of mothers with lower prenatal
• 35:53anxiety and depression.
• 35:54So again if Lactobacillus is beneficial,
• 35:57it's very interesting that the
• 36:00more Lactobacillus there was the
• 36:02less CCL 2.
• 36:02So that extends our previous findings.
• 36:06So in summary, increased stress
• 36:07and depression. I'm sorry,
• 36:09I'm struggling to move this zoom bar.
• 36:11Increased stress and depressive
• 36:13scores were increased associated with
• 36:16increased maternal CCL 2 and umbilical
• 36:18CCL 2 and a reduction in lactobacilli.
• 36:22And again, this is exciting to me personally
• 36:24because this is mirroring what we were
• 36:26seeing in our rodent model as well,
• 36:28suggesting that we have found something
• 36:30that is translatable and important.
• 36:32It wasn't just in mice that we were
• 36:34starting to see signals that it
• 36:35could be important in humans as well.
• 36:39So this is what I've been showing you
• 36:42now in humans that there's an increase
• 36:44in natively vaginal taxon opportunistic
• 36:46pathogens just in the small pilot study,
• 36:48an increase.
• 36:49You know,
• 36:50there's a relationship between
• 36:52psychometric scores and maternal
• 36:53CCL 2 in the third trimester.
• 36:55And finally in AD delivery.
• 36:57There's also this relationship
• 36:59between CCL 2 and lactobacilli.
• 37:01So it really looks like we've hit upon
• 37:03something that we might be able to target,
• 37:05which of course my,
• 37:07my,
• 37:07my hope and my dream and my goal
• 37:09as a psychiatrist is to actually
• 37:10be able to target something that
• 37:13will help my patients endure stress
• 37:15during pregnancy and overcome it.
• 37:17So I want to shift our attention a
• 37:20little bit to microbial metabolites,
• 37:22which as you'll remember from
• 37:23the beginning of my talk,
• 37:24we think is an important way that
• 37:26the microbiome is transmitted
• 37:27to the next generation.
• 37:29So I want to focus on a particular
• 37:31metabolite, which is tryptophan.
• 37:33And so tryptophan has a very
• 37:35mixed history in psychiatry.
• 37:37It's been tried over the years to
• 37:40cure a variety low tryptophan diets
• 37:42have been tried high tryptophan
• 37:43diets with mixed results.
• 37:45And So what we think is that in in my
• 37:47lab is that this one of the reasons
• 37:49that there might be mixed results
• 37:51is because there might be a lack of,
• 37:53there is a lack of consideration for the
• 37:55microbes that might be metabolizing it.
• 37:57So if you're giving a boatload of
• 37:59tryptophan to an individual who has a
• 38:01lower level of tryptophan metabolizers,
• 38:03they might not be using it and
• 38:04utilizing it in the same way that an
• 38:07individual with a healthy number of
• 38:08tryptophan metabolizers might be able to.
• 38:10So the hypothesis that we're going
• 38:12to be testing in the last portion
• 38:14of my talk is that maternal stress
• 38:16is reducing tryptophan metabolizers
• 38:17in a way that shifts,
• 38:19that disregulates the production
• 38:20of really key metabolites.
• 38:22Here in red are some metabolites that are
• 38:25known to be neurotoxic or Mal disadvantage,
• 38:27disadvantageous for your health.
• 38:29And in green on the right are some
• 38:32beneficial tryptophan metabolites.
• 38:33And it gets a little bit confusing.
• 38:34So don't worry,
• 38:35I'll be helping you remember
• 38:37all your serotonin metabolism.
• 38:39So that's our hypothesis that prenatal
• 38:42stress might be influencing neurodevelopment
• 38:44through changes in metabolism.
• 38:46And so how do we go ahead and test that?
• 38:48So the tryptophan story
• 38:49again is complex and has a
• 38:51missed mixed history in psychiatry.
• 38:52But just to refresh your memory,
• 38:54the majority of the tryptophan,
• 38:56virtually all of it comes from
• 38:58your diet and it's either taken
• 39:00up by enterocytes in your gut,
• 39:02you as the host or it's
• 39:03metabolized by gut microbes.
• 39:04And it's thought that might the gut
• 39:07microbes are metabolizing tryptophan
• 39:08differently than the host is.
• 39:10So the metabolites of kind of tryptophan,
• 39:12Probably the most famous is serotonin,
• 39:15which of course is important in adulthood,
• 39:17but in the fetus is incredibly important
• 39:19for things like external migration,
• 39:21sceptogenesis just of a host
• 39:24of different mental processes.
• 39:26And then kinuranine,
• 39:27which is known to have a role
• 39:28in immune function and indulse,
• 39:30which is known to be anti-inflammatory
• 39:31and associated with health.
• 39:33And of note,
• 39:34microbes in terms of producing
• 39:35indulse is the major source,
• 39:37if not the only source of indulse.
• 39:38It's a little bit of a controversy.
• 39:40Every field has its controversy.
• 39:41This is one of the controversies
• 39:43in the field.
• 39:45So I'm going to be focusing now
• 39:46on some of these key metabolites.
• 39:48And so we were excited to see
• 39:51this is a few years ago now and
• 39:53pictured here is Jeff Galley,
• 39:54who's a really talented
• 39:56research scientist in my group.
• 39:58We were excited to see that on
• 40:00a collaboration we had with
• 40:01Chris Dunkel shedder at UCLA,
• 40:02which I mentioned earlier,
• 40:04Bifidobacteria dentium,
• 40:05which is a major triptophan metabolizer,
• 40:08this is AR1.
• 40:09They had funded to look
• 40:11at maternal infant dyads.
• 40:13They were very generous and sent us
• 40:16all their samples from the infant.
• 40:18So these are now infants.
• 40:20We're examining the infant's
• 40:22microbiome that were sent to us,
• 40:24and then looking back and looking at
• 40:26the relationship to maternal anxiety
• 40:28and depression during pregnancy.
• 40:30And what we found was that there
• 40:32was a significant reduction in
• 40:34bifidobacteria dentium in infants
• 40:36born to mothers with higher levels of
• 40:39depression and anxiety during pregnancy.
• 40:41And we were excited about that
• 40:42because we have been seeing for
• 40:44several years in our mouth studies
• 40:45that there's a significant reduction.
• 40:47And I'll point your attention
• 40:49here to the central figure,
• 40:51but we've now shown this over and
• 40:53over again that there's a significant
• 40:55reduction in Paracetarella,
• 40:56which is another major tryptophan
• 40:57metabolizer in our mouse model.
• 40:59So we now had two converging
• 41:00lines of evidence,
• 41:01one from humans collected across
• 41:02the country as well as our mice
• 41:05here in Ohio that tryptophan
• 41:07metabolizers were significantly
• 41:08reduced with stress during pregnancy.
• 41:10And so we also looked at,
• 41:15so if there's a reduction in metabolizers,
• 41:16is there an increase in tryptophan
• 41:18because it's not being,
• 41:19it's not being metabolized.
• 41:20The short answer is yes.
• 41:21This is now content from the maternal gut,
• 41:24the ileal content.
• 41:25There's a significant increase
• 41:26with stress of tryptophan,
• 41:27which dovetails nicely with that.
• 41:29And so we went ahead and looked
• 41:32at Bifidobacterium in our mice
• 41:33and what we found is there's a
• 41:35significant reduction into adulthood.
• 41:37So these are now offspring at
• 41:40week three-week four and week 5,
• 41:41which is adolescence and we
• 41:43continue to see a a significant
• 41:44reduction of this in mice.
• 41:46So again, we're seeing it in humans,
• 41:49in infants and we're also seeing it in in,
• 41:52in rodent offspring that there's a
• 41:54significant reduction in stress.
• 41:55And this is also true for the Parasiterella.
• 41:58So in two major electric treatment
• 42:00metabolizers we're seeing in the
• 42:02reduction during pregnancy as
• 42:04well as during the services here
• 42:05in the mothers and then we're
• 42:07also seeing it in the offspring.
• 42:09So we decided to focus on this.
• 42:11We looked at other aspects
• 42:13of tryptophan metabolism.
• 42:14So just to refresh everyone's memory,
• 42:16this is the the pathway so
• 42:18tryptophan can be metabolized to
• 42:20serotonin or kinurine and then
• 42:22go down the kinurine pathway.
• 42:24And what we're finding is I'm
• 42:25showing you here data that there's
• 42:27changes in the different enzymes.
• 42:29So these are increased with stress.
• 42:31You can see here in the maternal
• 42:33colon as well as in the placenta.
• 42:35There's also changes in the
• 42:37arrow hydrocarbon receptor,
• 42:39which is mediated by the change
• 42:41in tryptophan metabolite.
• 42:42So it really looks like we're on
• 42:44several key aspects of this pathway.
• 42:46We are seeing shifts.
• 42:47So I'm just trying to explain to
• 42:49you that there's shifts not just
• 42:50in tryptophan but as well as the
• 42:52enzymes that are metabolizing
• 42:53it and in several key locations,
• 42:55including the gut,
• 42:56the placenta and in the colon.
• 43:00We then looked in the fetal brain
• 43:02because we wanted to see if there
• 43:03was a shift there as well.
• 43:04And the short answer is yes.
• 43:05I'm not reminding you that tryptophan
• 43:08goes into the cells through transporters.
• 43:10And all along this pathway
• 43:12illustrated here on the right,
• 43:13we're seeing significant changes in
• 43:16tryptophan related gene expression.
• 43:18So this is all gene expression data
• 43:21from the fenial brain on embryonic day 17.
• 43:24So it's disrupted now.
• 43:25I'm now showing you it both on
• 43:27the maternal side and the placenta
• 43:29as well as in the fetal brain.
• 43:30So we decided to continue on this pathway.
• 43:33So what I've shown you so fire is
• 43:35that there's changes in tryptophan
• 43:37with maternal stress.
• 43:38And then we're looking at these
• 43:39metabolites and this is pilot data
• 43:41that we're actively replicating.
• 43:42But it does look like, yes,
• 43:44there's a significant increase in
• 43:47these more toxic metabolites in
• 43:50both the fetal plasma as well as
• 43:52in the ileal content of the fetus.
• 43:54And So what I think that the one
• 43:57of the exciting but also complex
• 43:59things that
• 43:59we face is that it's not just I can't,
• 44:01we can't just think of things as good,
• 44:02as bad it, but it's really the dysregulation.
• 44:04So even cytokines aren't just good or bad,
• 44:06but it's the dysregulation of the cytokine.
• 44:08And I don't think tryptophan is
• 44:09either good or bad, but it's,
• 44:11it's dysregulation and the shifting of
• 44:13the balance of its metabolites that we
• 44:15think might be shaping neurodevelopment.
• 44:17And so just to remind you,
• 44:19I showed you now it seems like
• 44:21lifetime ago there is a significant
• 44:23increase in neuroinflammation,
• 44:24which is the bottom part
• 44:26of this hypothesis here.
• 44:27So we are seeing key checks,
• 44:29checkpoints being met here
• 44:32along our hypothesis.
• 44:33So we really wanted to ask
• 44:35can we orchestrate this?
• 44:36Can we take advantage of what we're seeing
• 44:39and try to target this with the long
• 44:41term goal of bringing this to clinic.
• 44:43And so of course we have to start in mice,
• 44:45but if maternal stress is
• 44:47changing tryptophan metabolizers,
• 44:48can we then address this and shifting
• 44:52the balance towards more neurotoxic or
• 44:55less maladaptive tryptophan metabolites
• 44:57and this is impacting neuroinflammation.
• 44:59Can we hear,
• 45:01buffer the pregnancy in the developing
• 45:03fetus in a way that would be beneficial?
• 45:06And just to remind you that we do
• 45:08see changes in the HR which is the,
• 45:10among other things is a receptor
• 45:12for these metabolites.
• 45:12So This is why we're driven to
• 45:14do the following experiment.
• 45:16So what we did is we took our regular
• 45:19model of stress and we added a probiotic
• 45:21so that mice were administered A probiotic.
• 45:23I'll be showing you data
• 45:25both from parasitorella,
• 45:26which again we had seen reduced
• 45:27in the mouse pregnancies,
• 45:28and Bifido bacteria redemption,
• 45:29which we had seen reduced in human
• 45:32pregnancies and then we replaced it.
• 45:33So if it's reduced, simple question.
• 45:35If it goes down with stress,
• 45:36if we give it back,
• 45:38can we benefit some of the outcomes
• 45:40I've shown you in the course of my talk?
• 45:42And so the first thing that's
• 45:44important to me is whether or
• 45:45not it's going to stick around.
• 45:46So spoiler alert,
• 45:47if you go to Whole Foods and
• 45:48buy some probiotics,
• 45:49probably going to go right through you.
• 45:50If I were to do an experiment
• 45:53similar to this for you,
• 45:54you wouldn't see any change because it's
• 45:56actually they would just pass through.
• 45:58So that's part of why we were
• 46:00givaging and that's why we repeatedly
• 46:01administrated it as we really wanted
• 46:03it to stick around during this critical
• 46:05neurodevelopmental time points.
• 46:06So yes,
• 46:07you can see here that administration
• 46:09of Bifidobacterium dentium.
• 46:10We then looked at the colonic stool,
• 46:12it stuck around,
• 46:12which is critically important
• 46:14to us in this experiment.
• 46:15Next we wanted to see if it was beneficial.
• 46:18And you think four years into
• 46:20this pandemic I wouldn't be
• 46:21struggling with this silly zoom bar,
• 46:23but it's literally over my graph
• 46:25and I cannot
• 46:27move it, so I can't see what this graph says.
• 46:30Here we go. This is one of the important
• 46:34findings is that we have consistently
• 46:35seen and one of the ways we know that
• 46:38we're stressing the animals is that
• 46:39we see a change in weight even when
• 46:41we standardize it to litter size.
• 46:43So when we look at the weight gain
• 46:46of the dams of the rodent moms,
• 46:47significant weight loss or lack of
• 46:49weight gain is what we find with stress.
• 46:51And what we found is that when
• 46:53we administered Bifida bacteria,
• 46:54dentium, this was ameliorated.
• 46:55So we were very excited about that.
• 46:57Nothing we've ever done in the
• 46:58course of our lab work has ever
• 47:01prevented this weight loss.
• 47:02So this is really positive in our opinion.
• 47:05And then we also saw a significant
• 47:07reduction of levels of CCL 2 in the
• 47:10maternal plasma with the administration
• 47:11of Bifida bacteria dentium.
• 47:13Next we looked at the liver and we and
• 47:15this is now switching to parasitorella.
• 47:17We found a significant effect of
• 47:19parasitorella in both the fetal liver
• 47:21as well in the as well as the fetal
• 47:23grain in terms of reducing Illinois 6.
• 47:25And then finally and most importantly
• 47:28perhaps is that the reduction in social
• 47:31behavior that we see with stress was
• 47:33ameliorated as well in in females,
• 47:36not in males,
• 47:37which I'm happy to discuss during the Q&A.
• 47:39But we saw a significant,
• 47:41we saw a significant amelioration of that.
• 47:43So they won't,
• 47:44they went back to preferring to engage
• 47:46with a social with a con specific
• 47:48with another rodent over an object.
• 47:50Next we're turning our attention
• 47:52to some of these metabolites.
• 47:53So again to remind you here on the
• 47:55left kineric acid is thought to be
• 47:57beneficial and we saw a significant
• 47:58increase kryonic acid in the maternal
• 48:00plasma here on the left as and we
• 48:03saw a significant increase with
• 48:05Parasiterella in the fetal plasma
• 48:07of another beneficial metabolite
• 48:09which is Indo 3 acetic acid.
• 48:11So we were very excited about
• 48:13that and finally can urinate in
• 48:15the maternal ileal content.
• 48:17What we saw,
• 48:19we saw that Parasiterella reversed the
• 48:21significant increase of that with stress,
• 48:23which is very promising.
• 48:25And then finally Tryptophan school was
• 48:28normalized with the treatment of with
• 48:30paracettorella in the maternal gut content.
• 48:32So it really does appear that we have
• 48:35hit on a translatable target that we
• 48:38can then work to prevent the negative
• 48:40sequela of stress during pregnancy.
• 48:43So this is my main conclusion.
• 48:45I haven't wasted a decade of my life,
• 48:46which is quite the relief.
• 48:48But more seriously,
• 48:51there's both converging preclinical and
• 48:53clinical evidence that prenatal stress,
• 48:55it is associated with ultra microbiome
• 48:57in both human and rodent pregnancies on
• 48:58the mom as well as in the offspring.
• 49:01We have evidence that CCL 2 is a key
• 49:04factor in all of this and is both
• 49:06influenced by stress and the microbiome.
• 49:08And at least in in rodent we
• 49:10have shown that
• 49:11it is sufficient to induce changes.
• 49:13And in humans we are seeing an
• 49:14emerging signal that it might also be
• 49:16influenced by stress and potentially
• 49:18playing a role there as well.
• 49:19And that I hopefully have uncovered
• 49:21something that could be a translational
• 49:23target for me to focus on in
• 49:24this next a decade of my career.
• 49:26With that, I'll stop and I would
• 49:30wouldn't be a good talk without thanking
• 49:31the wonderful members of my lab.
• 49:33I feel really lucky to work with
• 49:34some really bright, dedicated
• 49:37scientists. I'd like to thank my husband
• 49:39again for manually collecting all the
• 49:41samples I showed you from our study, as well
• 49:43as and generally being very supportive.
• 49:45My mentor, Mike Bailey,
• 49:46who's at Nationwide Children's Hospital
• 49:48who taught me everything I Googled,
• 49:49I googled Ohio State stress
• 49:51microbiome back in 20, 14.
• 49:53And his name came up and I called,
• 49:55emailed him and he's been a
• 49:57wonderful mentor ever since.
• 49:58And then, of course,
• 49:59I'd love to thank my fund,
• 50:01my funding sources,
• 50:01and then all of you for your time,
• 50:04thank you for listening to me today.