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MAPPING THE PARKINSONS BRAIN IN SPACE AND TIME

March 31, 2025
ID
12954

Transcript

  • 00:00It's my pleasure to introduce
  • 00:03doctor Sanjun Dong. He's an
  • 00:05associate professor in neurology
  • 00:07and in,
  • 00:08biomedical
  • 00:09informatics and data science.
  • 00:12He he I was fortunate
  • 00:13to recruit
  • 00:14him from Harvard where he
  • 00:16was directing,
  • 00:17the genomics and bioinformatics
  • 00:19hub,
  • 00:20and, I'm thrilled that you're
  • 00:23here. Actually, your lab is
  • 00:26now fifteen people already or
  • 00:27something. It's really, amazing, and
  • 00:29I can't can't wait
  • 00:31to to hear more about
  • 00:32your work. Thank you, Clemens.
  • 00:35So honored to be here.
  • 00:36Last time I was so
  • 00:37excited and nervous was when
  • 00:39I was giving a speech
  • 00:39on my wedding, actually.
  • 00:41But, let's see. So,
  • 00:45good afternoon, everybody
  • 00:46everybody. And, at first, I'd
  • 00:48like to, welcome and, of
  • 00:50course, congratulations to Clemens for
  • 00:52the Adam Center. Welcome here.
  • 00:54Ladies and gentlemen, and, today,
  • 00:56I'm going to report you
  • 00:58what one of the project
  • 00:59that, we are working here
  • 01:01with Clemens about the spatial
  • 01:02transformers of human brain.
  • 01:06As we know,
  • 01:07Clemens already give good enough,
  • 01:09enough intro introduction about the
  • 01:11the disease of progression when
  • 01:14the Parkinson progress
  • 01:15and basically
  • 01:16moving start with, like, a
  • 01:18a non motor symptom and
  • 01:19then motor symptom and then
  • 01:20later dimensional, like, cognitive impairment.
  • 01:23But, that's clinically happened. But
  • 01:25pathologically,
  • 01:26when you look into the
  • 01:27brain,
  • 01:28the Lewy body, which is
  • 01:29a whole marker for,
  • 01:30pathologic whole marker of Parkinson's
  • 01:32is aggregate of alpha synuclein
  • 01:34protein, also spread across the
  • 01:36brain from the,
  • 01:38olfactory bulb to the stem
  • 01:40brain stem to, limbic system
  • 01:42and then eventually go to
  • 01:43the cortex areas.
  • 01:45So,
  • 01:48how this has happened,
  • 01:50how this happening,
  • 01:52this kind of transition,
  • 01:54clinically and, pathologically
  • 01:56are whether they are driven
  • 01:58by any marker or or
  • 01:59driver molecularly.
  • 02:01So that's a question we
  • 02:02want to understand. So few
  • 02:03years back when I was
  • 02:04working with Clemens, in Harvard,
  • 02:07we look at this human
  • 02:08postmortem brain,
  • 02:09a one hundred nineteen brain,
  • 02:11and we dive into the
  • 02:12specific brain regions and use
  • 02:14a laser capture microdissection,
  • 02:16which is, this this technology
  • 02:18become available before the single
  • 02:19cell is available there. So
  • 02:21we manually do this capture
  • 02:22single cell and specific brain
  • 02:24region
  • 02:25and, target to three brain
  • 02:27regions like a middle brain
  • 02:28for dopant
  • 02:30dopant neuron and the corticoster
  • 02:32regions for upper middle neurons.
  • 02:34And, then we pull the
  • 02:35neuron together, each type of
  • 02:37neuron together and do the
  • 02:38total RNA and deep RNA
  • 02:39sequencing.
  • 02:41And there are several interesting
  • 02:42messages from the work. One
  • 02:43of the main message is,
  • 02:45we found many,
  • 02:47known,
  • 02:48polycholine gene and link RNA
  • 02:50or non coding RNA expressed
  • 02:51in the in the brain,
  • 02:52of course. For example, seventeen
  • 02:53thousand of polygonal gene and
  • 02:55seven thousand known non coding
  • 02:57RNA expressed. But we also
  • 02:58identified many novel
  • 03:00non coding RNA that nobody
  • 03:01had found them before also
  • 03:03highly expressed in document neuron.
  • 03:05For example, we found, like,
  • 03:06around twenty six thousand of
  • 03:07enhanced RNA and around ten,
  • 03:10eleven thousand
  • 03:11of circular RNA in the
  • 03:13in the brain.
  • 03:14So I want to spend
  • 03:15a minute here to talk
  • 03:16about one of the RNA,
  • 03:17which is circular RNA.
  • 03:19Usually, the DNA can be
  • 03:21transcribed linearly to linear RNA
  • 03:23like this happened. But they
  • 03:24also,
  • 03:25show that,
  • 03:27since, around two thousand fourteen,
  • 03:29two found there's the RNA
  • 03:30can also,
  • 03:31form circular RNA through back
  • 03:33splicing as you can see
  • 03:35here. And this circular RNA,
  • 03:36because their shape is circular,
  • 03:38there's no free end. They
  • 03:39are more stable. The half
  • 03:40life is ten times longer
  • 03:41than the linear RNA. So
  • 03:43they're perfect candidate for biomarker.
  • 03:45And this circular RNA, very
  • 03:46interesting to show they're dominant
  • 03:48in brain versus the other,
  • 03:50tissues. And more interestingly, as
  • 03:53you can see in the
  • 03:54bottom right corner here,
  • 03:55comparing the synapsosome versus neuron
  • 03:58soma, this sarcoid RNA is
  • 03:59more enriched in the synapses
  • 04:02which is, kind of puzzling
  • 04:04too.
  • 04:05And in our data, we
  • 04:07look at this, eleven southern
  • 04:09circle RNA. We found many
  • 04:10of them actually transcribed from,
  • 04:12Parkinson risk gene. For example,
  • 04:13snoopling GBA log two and
  • 04:16the rims two, rims one,
  • 04:18and, VPS thirteen c, for
  • 04:20example.
  • 04:21And, also, many of them
  • 04:22also transcribe from a synaptic
  • 04:23genes. Like, out of, eleven
  • 04:26hundred synaptic gene,
  • 04:28nine hundred of them transcribed
  • 04:29in, circular RNA.
  • 04:31And many circular RNA actually
  • 04:33when we look at this,
  • 04:34brain sample between different stage
  • 04:36of Parkinson's, like, control versus
  • 04:38late stage and early stage,
  • 04:40some sarcoRNA even start to
  • 04:41show
  • 04:42changes
  • 04:43even in early stage of
  • 04:44prodromal stage of PD.
  • 04:46And one of the targets
  • 04:47one of the candidates from,
  • 04:49this study is,
  • 04:52is DNA j c six.
  • 04:53We are quite interested in.
  • 04:55As you can see here,
  • 04:56the DNA j c six,
  • 04:57the messenger RNA does not
  • 04:59change between PD control, but
  • 05:01the circular RNA as the
  • 05:02the
  • 05:03form, it it changes significantly
  • 05:05and drop a lot in
  • 05:06PD. And DNA j c
  • 05:07six, I mean, there's the
  • 05:09following talk talking about this
  • 05:11two but, DNA j c
  • 05:13six is a known, a
  • 05:14protein also known as auxilin.
  • 05:16It's a very important,
  • 05:18player in the,
  • 05:19encoding of the cholesterol mediate
  • 05:22endocytosis.
  • 05:23So this, Vasco in the
  • 05:25snatches need to be encoded
  • 05:27and then be reused, recycled.
  • 05:28If this encoding is not
  • 05:30working,
  • 05:30then there's a lot of
  • 05:31buildup or accumulation of coated
  • 05:34vesicle and then then a
  • 05:35neurotransmitter like dopamine cannot be
  • 05:37released timely. So that's a
  • 05:38very important player there. Of
  • 05:40course, the protein itself. But
  • 05:41whether circular RNA play a
  • 05:43function in that step of,
  • 05:44for example, synaptic loss in
  • 05:46early stage of PD that's
  • 05:47still a question mark. So
  • 05:49in my lab we follow-up
  • 05:50this
  • 05:51discovery. Now we go to
  • 05:52the white lab. I mean
  • 05:53this is something really I
  • 05:54start to learn from after
  • 05:56moving here with using a
  • 05:58build organoid model.
  • 06:00We want to,
  • 06:01inject or or treat this
  • 06:03organoid p d organoid model
  • 06:04with DNA j c c
  • 06:05circular RNA to see whether
  • 06:07they can rescue the p
  • 06:08d symptom. This is really
  • 06:10pioneered by, one of the
  • 06:12Thailand poster in, Maria in
  • 06:13my lab, and, we are
  • 06:14testing different way of deliver
  • 06:17circular RNA. For example, using
  • 06:18EV to wrap into the
  • 06:20axon extracellular vesicle and, put
  • 06:22a surface marker to make
  • 06:24the brain target specific and
  • 06:25also try another way, the
  • 06:26lipid nanoparticle there is too.
  • 06:28So please stay in tune
  • 06:30on this, research and there's
  • 06:31really a lot of risk
  • 06:33on the on the way
  • 06:34I can see. Okay. Back
  • 06:35to today's focus.
  • 06:38We more previously, we focused
  • 06:39on specific brain regions and
  • 06:41like middle brain or cortex,
  • 06:43but the brain region is
  • 06:44not just one piece of
  • 06:45block. Right? If you look
  • 06:46at this, very famous, figure
  • 06:49from Santiago,
  • 06:51Ramani
  • 06:53Haaha's figure is drawing.
  • 06:55And you see the the
  • 06:56the cortex region is actually
  • 06:57formed by different layers or
  • 06:59sub layers. They are not
  • 07:00exactly the same uniform. Right?
  • 07:02And, so that's why we
  • 07:04studied spatial transformics.
  • 07:06And spatial transform is we
  • 07:07use technology called ten x
  • 07:08vision and cut the brain
  • 07:10slice and put barcode on
  • 07:11each spot of the x
  • 07:13y coordinate of the of
  • 07:14the slice and it measures
  • 07:15RNA each coordinate. And then
  • 07:17and then meanwhile, we do
  • 07:18single cell RNA seek
  • 07:20to to match up the
  • 07:21same data to see whether
  • 07:22the cell type deconvolution there's.
  • 07:24So for those that are
  • 07:25less familiar with single cell
  • 07:26and and spatial,
  • 07:28I borrowed this analog for
  • 07:29you to understand. Basically, if
  • 07:31you do the bulk is
  • 07:32you make it a smoothie
  • 07:33for everything together. A single
  • 07:35cell, you mix the different
  • 07:36things together, but they are
  • 07:37still like a mix but
  • 07:38individually.
  • 07:39And spatial, you form a
  • 07:40pattern there based on the
  • 07:42the location of of the,
  • 07:44of the cells and the
  • 07:45expression levels there.
  • 07:48So we start with around
  • 07:49hundred brains, and this brain
  • 07:52are very well characterized clinically
  • 07:54and pathologically.
  • 07:55And they can span the
  • 07:57whole ten post,
  • 07:58trajectory of Parkinson's, development
  • 08:01from healthy control
  • 08:03to the late stage PD
  • 08:04and also some, one third
  • 08:06of sample, we have also
  • 08:07called instant Lewy body, which
  • 08:09means they are clinically healthy.
  • 08:10No tremor, no, dementia. But
  • 08:13pathologically, there's brain already had
  • 08:14Lewy body found in the
  • 08:15brain. So this is very
  • 08:16unique sample to help us
  • 08:18identify those markers on early
  • 08:19PD.
  • 08:22So j a is a
  • 08:23very talented post scientist
  • 08:25in my lab. He developed
  • 08:26this computational advanced computational,
  • 08:28algorithm or pipelines
  • 08:30to look into those spatial
  • 08:31data, and we identify seven
  • 08:34clusters in the space, based
  • 08:36on the spot data. And
  • 08:37these seven cluster align pretty
  • 08:38well to the seven layers
  • 08:40of cortical like layer one
  • 08:41to six and why matters.
  • 08:43And we also benchmark with
  • 08:44another data set which is
  • 08:45manually annotated by a pathologist
  • 08:48and our layer marker gene
  • 08:50highly correlated with what they
  • 08:51found in their manual annotations.
  • 08:54And,
  • 08:55we also, he also developed
  • 08:57a a machine learning based
  • 08:58tool called layer smoother. As
  • 09:00you can see, the original
  • 09:01data looks
  • 09:02sparse and and very,
  • 09:04kind of noisy noisy in
  • 09:06some layer boundary.
  • 09:07And with this layer smoother,
  • 09:09the border is much cleaner
  • 09:10and, data is cleaner too.
  • 09:12So we enhance the data
  • 09:13a lot based on this,
  • 09:14machine learning algorithm.
  • 09:17And it also show this
  • 09:18algorithm works pretty well when
  • 09:20we compare their benchmark or
  • 09:21ground truth tools
  • 09:23ground truth annotation based on
  • 09:25the based on the from
  • 09:26the pathologist
  • 09:28our layer smoother actually improved
  • 09:31the original clustering a lot.
  • 09:33And also, we also identify
  • 09:35some of the,
  • 09:36regions. For example, here is
  • 09:38not really annotated by the
  • 09:39even by the pathologist, but
  • 09:40we identified those substructure stairs
  • 09:43based on our laser smoother.
  • 09:46So next question we ask
  • 09:47is what kind of cells
  • 09:49presented in each layers. Right?
  • 09:51And whether, they're uniform distributed
  • 09:54or some cells are more,
  • 09:57presented in, certain layers. So
  • 09:59this joint work between
  • 10:01my lab and Clem's lab
  • 10:03and Jacob and Jay, a
  • 10:04team of very beautifully to
  • 10:06get this
  • 10:07cell type convolution
  • 10:09in a spatial wise and
  • 10:10we see each major cell
  • 10:11types
  • 10:12they, their relative location in
  • 10:15each layers. And one of
  • 10:16the take home message here
  • 10:17is when you look at
  • 10:18the glu glutamatergic
  • 10:20neurons and the glutamatergic neuron
  • 10:23have show very strong
  • 10:25layer specificity.
  • 10:26Meaning,
  • 10:27the subtype of glutaminergic neurons,
  • 10:30they can present in certain
  • 10:31layers.
  • 10:32On the other hand, if
  • 10:33you look at the GABAergic
  • 10:34neuron, they don't have so
  • 10:36strong layer specificity as glutaminergic
  • 10:38neurons.
  • 10:40Maybe this figure is not
  • 10:41so, intuitive. Let's look at
  • 10:43the movie here.
  • 10:45This is one of the
  • 10:46sample we found and you
  • 10:47can still see the layer
  • 10:49marker gene for certain,
  • 10:51sub cell types. They are
  • 10:53highly
  • 10:54presented. I wanna show this
  • 10:56again but it's kind of
  • 10:57positive and
  • 10:58you can imagine the the
  • 11:00different
  • 11:01subtype of marker gene. They're
  • 11:02highly correlated or highly specific
  • 11:04in certain layers.
  • 11:07And there are more samples
  • 11:08there and we have a
  • 11:10hundred samples but there's a
  • 11:11few other samples we show
  • 11:13the glucanergic neuron show very
  • 11:14strong layer specific copper neuron
  • 11:17more
  • 11:17uniform relatively and other glial
  • 11:20cells also show there's their
  • 11:22own, cell layer specificity there.
  • 11:25Now next question is, of
  • 11:26course, we wanna study Parkinson.
  • 11:27Right? We may want to
  • 11:29understand how this location or
  • 11:31this, marker molecular signal change
  • 11:34along the Parkinson progressions.
  • 11:36So we viewed a, using
  • 11:38the a metric binomial model
  • 11:40to test each gene and
  • 11:41each layers and see whether
  • 11:43any gene show
  • 11:45a link to the Parkinson
  • 11:46progression by regress with the
  • 11:48Lewy body scores and also
  • 11:50with just other covariance here
  • 11:51as you can see.
  • 11:53So what we found very
  • 11:54we found a lot of
  • 11:55gene, but this gene formed
  • 11:56very interesting pathway. So this
  • 11:58figure I'm sorry. I apologize
  • 11:59for the busy figure, but,
  • 12:01the the the figure is
  • 12:03a circle plot. Each layer
  • 12:05is a,
  • 12:07each circle is a layer.
  • 12:08So layer one to to
  • 12:09six and then y matters.
  • 12:11And the pathway if the
  • 12:12pathway
  • 12:13is operate regulated
  • 12:15in, that layer along the
  • 12:17Parkinson's progression, it will show
  • 12:19a purple color. If it's
  • 12:20down regulated
  • 12:21along the progression, it show
  • 12:23the the yellow color. As
  • 12:24you can see, this pathway
  • 12:26are clustered based on their
  • 12:28similarity of the leading adenines
  • 12:29and we show some group
  • 12:31are are highly significant across
  • 12:33multiple multiple region. For example,
  • 12:35this is octave, oxidative phosphorylation
  • 12:38is a critical role for
  • 12:40mitochondrial energy,
  • 12:41generation
  • 12:42and for ATP
  • 12:43metabolic. And see this pathway
  • 12:45kind
  • 12:47of, getting,
  • 12:49downregulated
  • 12:50in along Parkinson reg regression.
  • 12:53There's other pathway linked to
  • 12:55this, energy
  • 12:56generation.
  • 12:57For example, the the protein
  • 12:58synthesis is a ribosome,
  • 13:00biogenesis.
  • 13:01They also get down spatially
  • 13:03in Parkinson across multiple layers.
  • 13:06And
  • 13:07meanwhile, we see other pathway
  • 13:09which is for example, immune
  • 13:11related pathway like t t
  • 13:12seventeen activation
  • 13:14and immune response and and
  • 13:16t cell regulation and and
  • 13:17also b cell top six
  • 13:19path response
  • 13:20they also get upregulated
  • 13:22in the along the pro
  • 13:23three d progression.
  • 13:25But we also see some
  • 13:27kind of,
  • 13:28hard to explain,
  • 13:29since, like, a neutrophil mediated
  • 13:31immunity
  • 13:32pathway that actually get down
  • 13:34here. So this is kind
  • 13:35of a little bit puzzling
  • 13:35for us too.
  • 13:38Another thing we see many
  • 13:40parts that relate to cell
  • 13:41response to the environment to
  • 13:43the, external stimuli
  • 13:45or environment of surveillance, they
  • 13:47also get go up,
  • 13:50including a drug response to
  • 13:52virus infection
  • 13:55to a biotic
  • 13:57infection there's this this pathway
  • 13:59the purple color show they
  • 14:00go up too.
  • 14:02And lastly, we see the
  • 14:03cell cell communication, synaptic activity,
  • 14:06those pathway go up along
  • 14:07progression, especially in the white
  • 14:09matter. This is likely to
  • 14:11do a, compensatory
  • 14:13response of neural degeneration that
  • 14:15the neural neural connection need
  • 14:17to go up at, along
  • 14:18the progression.
  • 14:21So last question we'll try
  • 14:22to address here is, do
  • 14:24those pathway change already early
  • 14:27of the PD or they
  • 14:28happen later?
  • 14:29So because we have well
  • 14:31characterized a sample in different
  • 14:32stage of Parkinson's,
  • 14:34we specifically look at the
  • 14:35early PD versus control.
  • 14:37And this group, as you
  • 14:38can see,
  • 14:39we when we,
  • 14:42when we look at late
  • 14:43PD and, versus control,
  • 14:45the the pathway looks pretty
  • 14:48mimic well with the Lewy
  • 14:50body progression.
  • 14:51But if you look at
  • 14:52the early PD
  • 14:53and some of the pathway
  • 14:55actually flipped the direction
  • 14:57as for example, in this
  • 14:58category highlight here, these are
  • 15:00energy generation like mitochondrial,
  • 15:02like,
  • 15:03oxygen phosphorylation.
  • 15:04They they speed up first
  • 15:07and pump up energy, but
  • 15:08later they get exhausted and
  • 15:10then they get, power off
  • 15:11globally. That's what we see
  • 15:13from this,
  • 15:15example.
  • 15:17And we also give live
  • 15:19a, this is ongoing work,
  • 15:21actually. This is a prototype.
  • 15:22We've had to build a
  • 15:23online open source web portal
  • 15:25to integrate all this data
  • 15:27to so biologists and neurologists
  • 15:28can
  • 15:29look into this system and
  • 15:31type their favorite gene and
  • 15:32check our sample and and
  • 15:33their how the gene change.
  • 15:35And this work is really
  • 15:36ongoing. I think this is
  • 15:37going to build a foundation
  • 15:38for for the AI model
  • 15:40in the future too.
  • 15:43So by that, I want
  • 15:43to wrap up my, presentation
  • 15:45today. PD five d provide
  • 15:47a unique, resources
  • 15:49and also hopefully build a
  • 15:50foundation
  • 15:51for precision medicine in the
  • 15:53future. And we look at
  • 15:54this Parkinson brain in multi
  • 15:56omics view and, glucanergic
  • 15:58neuron show very strong layer
  • 16:00specificity where GABAergic neuron is
  • 16:02more, relatively uniform, spatially distributed.
  • 16:05And as PD progress, we
  • 16:07see many interesting pathway
  • 16:08either go up down,
  • 16:10some will go up or
  • 16:11go up like synapses or
  • 16:13neurotransmission
  • 16:14communication or vesicle trafficking and
  • 16:16neuroinflammation
  • 16:17and the cell response to
  • 16:18external stimuli. Some go down
  • 16:20for some energy generations and
  • 16:22protein synthesis and metabolisms
  • 16:24and neutral field pathway too.
  • 16:26And we only see very
  • 16:27marginal cell composition change along
  • 16:29PD progression. This data is
  • 16:31not included in this slide.
  • 16:32And, energy related pathway appear,
  • 16:36activating in early stage of
  • 16:38PD but later become depleted
  • 16:39in, in the PD.
  • 16:41So this hopefully,
  • 16:43I can,
  • 16:44just show this, data as,
  • 16:47convince you really build up
  • 16:48data and get knowledge there
  • 16:50as a training center for
  • 16:51next phase of AI based
  • 16:53modeling there.
  • 16:54So lastly, I want to
  • 16:55thank everybody here to hear
  • 16:57my talk and, also like
  • 16:59to thank all the members
  • 17:00in my lab. This work
  • 17:02largely driven by, done by
  • 17:04by j in my lab
  • 17:05and a few other member
  • 17:06working on different aspect ASO
  • 17:08project. I also like especially
  • 17:09like to thank Clemens to
  • 17:10bring me to the stage
  • 17:11and to the field. This
  • 17:13is really great to follow
  • 17:14the whole scenes that you
  • 17:15lead in the years and
  • 17:16the many collaborator in ASOP,
  • 17:18also Brainco project.
  • 17:21And, and thank all the
  • 17:22sponsors here too including APDA.
  • 17:25I see Rebecca here at
  • 17:27is, where I gave my
  • 17:28first grant to start my
  • 17:29lab. Thank you so much.