MAPPING THE PARKINSONS BRAIN IN SPACE AND TIME
March 31, 2025Information
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- 12954
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- 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.