The cellular waste in your blood can tell you a lot about your health -any immune activation, mineral deficits, or stress hormones circulating through you. So, what do you think it means when chunks of cells, knocked loose by the shear stress of your own blood pressure, start turning up?
Dr Ramani Ramchandran at the Medical College of Wisconsin and his team are developing new tests for these cellular fragments in blood to determine what they can tell us about your whole-body health.
Read the original article: https://doi.org/10.1172/jci.insight.151813
Image Credit: SciePro/Shutterstock
The following transcript is automatically generated.
00:00:01 Will Mountford
Hello, I’m Will, welcome to Researchpod. By the end of this very podcast, your heart will beat something in the region of 1500 times, and moved around 130 litres of blood. That’s a lot of oxygen and sugars moving to nourish your cells, and a lot of cellular waste being cleared.
That waste can tell you a lot about your health – any immune activiation, mineral deficits, or stress hormones you have circulating. So, what do you think it means when chunks of cells , knocked loose by the shear stress of your own blood pressure, start turning up?
Dr Ramani Ramchandran at the Medical College of Wisconsin and his team are developing new tests for these cellular fragments in blood to determine what they can tell us about your whole-body health.
00:00:56 Will Mountford
Doctor Ramchandran, Hello there.
00:00:58 Dr Ramchandran
00:00:59 Will Mountford
Alright, thanks so much for your time today. Just kind of by way of introduction for the listeners at home and for a little bit of my benefit as well.
00:01:06 Will Mountford
Can you tell us a bit about your career trajectory so far? What’s going to lead you to medicine or through clinical research or if there’s anything personal that you’ve been striving after?
00:01:16 Dr Ramchandran
I started my career in India and I did my Bachelors and masters in in biochemistry and microbiology in India and then came.
00:01:26 Dr Ramchandran
To the United States to go to Graduate School.
00:01:30 Dr Ramchandran
And got my pH. D At the Augusta University, where I study the transcription of beta globin genes.
00:01:37 Dr Ramchandran
And very basic biology.
00:01:39 Dr Ramchandran
Really what I wanted to do at that point was really apply my research into the clinic and that’s been my quest all through my career.
00:01:47 Dr Ramchandran
And so that led me to a fellowship at Harvard, where I work with Vikas Sukhatme, and where we we’re studying how blood vessels are formed in tumours.
00:02:00 Dr Ramchandran
And so that was our focus, but.
00:02:02 Dr Ramchandran
Soon I realised that
00:02:04 Dr Ramchandran
The tumour vessels were a lot.
00:02:07 Dr Ramchandran
Different than normal vessels. And so and we didn’t really know a lot more about normal vessels.
00:02:12 Dr Ramchandran
So I decided to go and study normal vessels first, and that’s where I my passion for using zebrafish, a tiny fish from a Native India, came in, and that’s where I.
00:02:23 Dr Ramchandran
Focused on studying blood vessels in zebrafish.
00:02:26 Dr Ramchandran
That took me onto.
00:02:28 Dr Ramchandran
The next step of my academic career, where I went to the National Cancer Institute, National Institutes of Health in Bethesda as an NCI.
00:02:36 Dr Ramchandran
Scholar where I established the zebrafish model for studying vascular development in the trunk blood vessels actually in Bethesda, and soon I got recruited from there to the Medical College of Wisconsin, where I’ve established a programme in vascular biology. And this is where I’m.
00:02:56 Dr Ramchandran
Currently a professor in paediatrics and I study vessels, mostly in the brain and in the heart.
00:03:06 Dr Ramchandran
And so our today’s discussion is about these very tiny little structures called cilia that are found on these endothelial cells that lines the blood vessels of the brain and the.
00:03:16 Dr Ramchandran
Heart this project is a team effort and we have numerous labs in various parts of the United States that.
00:03:26 Dr Ramchandran
Play a critical role in this project and I’d like to specifically mention some of their name.
00:03:30 Dr Ramchandran
Doctor Surya Nauli from Chapman University. He was instrumental in working on cilia proteomics and and he’s a major component of this project. Doctor Sean Palecek, from the University of Wisconsin, Madison, he works on the role of cilia.
00:03:51 Dr Ramchandran
In vascular stability from a question of blood brain barrier and.
00:03:57 Dr Ramchandran
So he’s got a very critical role to play there.
00:04:01 Dr Ramchandran
Doctor Kevin Rarick from the Medical College of Wisconsin, who is developing traumatic brain injury models and trying to understand the role of ciliary protein as a biomarker of vascular health in those injury conditions.
00:04:19 Dr Ramchandran
And finally, Doctor Rahima Zanardi from Duke University in North Carolina, who is focused on understanding the role of cilia on red blood cells in the blood and how that might influence removal of cilia from the endothelium.
00:04:37 Dr Ramchandran
This postdoctoral fellows and technicians in these labs are also an integral part of this particular project, and each one is obviously working on the questions that I’ve already described in their respective labs. So this is the team, and we are also ably supported by a statistician, doctor Amy Pan.
00:04:58 Dr Ramchandran
And this work is funded by the National Institutes of Health. So that’s.
00:05:04 Dr Ramchandran
Sort of his story so far.
00:05:06 Will Mountford
I can mention that studying blood vessels for diseases, that makes a lot of sense, but I didn’t realise there was that much not known about blood vessels in healthy or regular tissue because it seems kind of like a fundamental part of biology of medicine that blood is transported around the body effectively and well, and that we should, you know, be on the best foot to understand that.
00:05:27 Will Mountford
Before we deal with when it goes wrong.
00:05:29 Will Mountford
If we could start by talking about, like you say, blood and blood vessels normally are working as healthily as they can do and when disease or dysfunction starts to come into that.
00:05:39 Dr Ramchandran
Yeah, so as you rightly pointed out, blood flow is and is a really a vital component of all organs and without flow most organs will fail.
00:05:51 Dr Ramchandran
In some ways, you would think that one would know a lot about this process already, but our ability to study blood vessels from a developmental perspective has been partly hamper by this fact that you need flow in order for the Organism to live.
00:06:11 Dr Ramchandran
But luckily in the fish.
00:06:14 Dr Ramchandran
Fish can survive without circulation, blood flow. And so they have their own sort of source of food, which is their yolk that gives them the food and so they can survive and they don’t need blood flow. So that allows us to probe more deeply into blood vessel formation, live inside.
00:06:33 Dr Ramchandran
In embryo and and the fish being transparent in an embryonic state, we can actually do microscopy where we don’t have to do anything invasive because it’s so transparent and it’s easy to view.
00:06:46 Dr Ramchandran
So I think the development of model systems, especially like zebrafish, facilitated the growth of or the development or studies of of blood vessels in in more debt.
00:06:58 Dr Ramchandran
And so we started to be able to understand how they form. We could take live images, live microscopy of vessels forming.
00:07:05 Dr Ramchandran
As they were developing, how they were connecting, how they were pruning, so these things were not as amenable as subsequently some some of this work.
00:07:14 Dr Ramchandran
Has matured into the mouse.
00:07:16 Dr Ramchandran
Blood vessels as well.
00:07:18 Dr Ramchandran
But obviously the mouse is is a is an opaque Organism and so it’s hard to look through them. But I would have to say before zebrafish chick did contribute a lot to blood vessel development.
00:07:30 Will Mountford
So cilia and endothelium, if we could start off with a high school biology approach to what those cells are and get into what happens when things go wrong.
00:07:39 Dr Ramchandran
Sure. So as I mentioned, our interest is this tiny structures called cilia. They almost like hairlike projection that come out of the endothelial cell, which lines the blood vessel and it faces the area of the floor, which is the lumen or the tube, where in the centre of the tube the blood is flowing, it’s projecting into that.
00:08:00 Dr Ramchandran
Lumen and so it is originally thought of as a blood flow sensor, so it senses the blow.
00:08:08 Dr Ramchandran
Now, silly is not only found in endothelial cells, there’s also found in most cells in the body. So it’s not just unique to individual cells, but in the endothelium it’s.
00:08:17 Dr Ramchandran
It was often thought of as a flow sensor, so when the flow is sensing it would bend and this bending would cause some changes to the cellular calcium and that.
00:08:28 Dr Ramchandran
Would lead to some downstream signals that would either lead to contraction and other sort of functions inside.
00:08:34 Dr Ramchandran
The cell now, the our interests and those of many others have. It has primarily come from studies where ciliary genes functions are lost in certain developmental conditions, such as Joubert syndrome and so on so on there.
00:08:54 Dr Ramchandran
Often these these patients have severe neurological deficits and other cognitive deficits. Cilia has been implicated in various human pathologies. That’s where the interest for.
00:09:08 Dr Ramchandran
Has sort of like enhanced in the biological sphere with so many different.
00:09:13 Dr Ramchandran
Organs where it is found, we have identified it associated with diseases, for example congenital heart disease, brain malformations.
00:09:22 Dr Ramchandran
I just talked to you.
00:09:23 Dr Ramchandran
About cognitive deficits, there are other conditions.
00:09:26 Dr Ramchandran
As well so.
00:09:27 Will Mountford
Going to think that something so small has such an impact on those massive structural damages later.
00:09:33 Dr Ramchandran
That’s right. That’s right. So especially in the heart with a lot of the congenital heart defect.
00:09:40 Dr Ramchandran
Mutations that have been identified in mice are all on insulin gene and most of them are in cilia genes.
00:09:46 Dr Ramchandran
What exactly do they do to cause the structural deficits? They just thought that they might be altering some structural elements of the cardiomyocytes or the way they are developing during.
00:10:00 Dr Ramchandran
In the heart and that might cause.
00:10:02 Dr Ramchandran
Different functional deficits in those cells, but it’s really not fully clear how they function in those organs to kind of express their disease phenotypes.
00:10:11 Will Mountford
Besides just the turning off of cilia genes causing them to not be expressed in all of those knock on effects, your research also looks at the desolation that when cilia are knocked off by I guess typically a mechanical force, either something you know knocking into them through the blood, another cell tumbling through, or maybe shear like pressure of blood moving. Is that right?
00:10:31 Dr Ramchandran
That’s right. So.
00:10:33 Dr Ramchandran
What’s been observed in a decade or so ago is that.
00:10:38 Dr Ramchandran
So not only silly, I would sense low blood flow, but if the blood flow goes higher and above a certain shear stress which is what the tangential force of the blood on the vascular on the vessel and if that flow increases, so like for example hypertension, you know blood pressure, where there is increased blood pressure you will get increased blood flow.
00:10:58 Dr Ramchandran
It was noticed that cilia from those endothelial cells were lost.
00:11:04 Dr Ramchandran
And so the.
00:11:06 Dr Ramchandran
Point was, what happens and why would cilia get lost from these cells?
00:11:11 Dr Ramchandran
And that was a first question, right? And second question was?
00:11:14 Dr Ramchandran
Where do these cilia go if they are lost?
00:11:16 Dr Ramchandran
These cells and then few years later, a couple of years ago, a group in Stanford published a very nice paper where they showed that most cells lose the entire cilium in the mammalian cells. And so these two sort of disparate observations kind of made us.
00:11:37 Dr Ramchandran
Realise that perhaps is a much more widespread phenomenon where ciliary loss from these cells could perhaps be tracked in some fashion.
00:11:48 Dr Ramchandran
So our logic was if there is our conditions where there is high floor, we could mimic that in the laboratory.
00:11:55 Dr Ramchandran
Setting could we detect cilia in the supernatants from these cells or in the fluid?
00:12:02 Dr Ramchandran
Where they are.
00:12:03 Dr Ramchandran
Bathing. And so that was our really our question and it turns out you indeed can. So when they are lost from these cells, we can actually detect them and their proteins.
00:12:15 Dr Ramchandran
In the supernatant from some of these cells, including not only endothelial cells.
00:12:20 Dr Ramchandran
Roger, Kidney epithelial cells.
00:12:22 Dr Ramchandran
Which is a primary source of psyllium and is associated with a with a very important genetic condition called the polycystic kidney disease, where there have numerous cysts in the kidney and it’s often associated with the ciliary dysfunction in the kidney cells.
00:12:36 Will Mountford
Are there any instances of cilia being trafficked to organs and causing some accumulation, some blockage? You mentioned that there was a link between silly loss and neurodegeneration. Is that similar to everything that I’ve heard about Alzheimer’s plaque buildup?
00:12:51 Dr Ramchandran
That’s a very interesting point, will I? I think that whether ciliary loss in cell types.
00:12:59 Dr Ramchandran
Such as let’s say for example in the brain in astrocytes and neurons and these cells that comprise the neuromuscular unit, whether those would cause the exacerbation of the Alzheimer disease phenotype where you have these proteins accumulating and maybe celery?
00:13:19 Dr Ramchandran
Fragments disruption, further exacerbating these processes or disrupting the normal functioning of these cells could clearly be influenced in my view.
00:13:30 Will Mountford
Have there been any instances of taking a lung sample or some kind of tissue biopsy and finding cilia that you know have come from elsewhere in the body that you know they’ve come adrift and got lodged?
00:13:41 Dr Ramchandran
That’s a very interesting point. I we don’t have that information yet, but but cilia do secrete these vesicles. These are small little sort of membrane parts that come out of this.
00:13:55 Dr Ramchandran
Cells and so it’s thought that these can travel long distances and perhaps and there is this concept of exosomes that people may be familiar with, with a similar kind of vesicles or or membrane structures which carry proteins and and RNA and lots of other things. Although we are in the infancy we believe that the sum of these extra.
00:14:15 Dr Ramchandran
Cellular vesicles or membrane fragments, carriers of proteins and RNA from cilia could be long distance communicated with other celebrity yet to to find their deposition in other cell types. It’s it’s ongoing research.
00:14:35 Will Mountford
What does it take to detect cilia?
00:14:38 Dr Ramchandran
Cilia contains a few 1000 proteins. Exact numbers are still not known and these proteins are native to cilia, meaning they are coming from the cell that they reside in.
00:14:50 Dr Ramchandran
So they’re not, they don’t make these proteins, they’re already in the cell and then they are transported inside into the cilium, so they carry a signature.
00:14:58 Dr Ramchandran
Of the cells that they represent.
00:15:01 Dr Ramchandran
And these proteins are can be identified. When this Penicillium breaks down you can think about blood being a place that you could identify these proteins.
00:15:11 Dr Ramchandran
CSF or cerebrospinal fluid is another place. A urine is another place that others have been able to detect. So we normally can detect these in various places. Various.
00:15:21 Dr Ramchandran
Fluids. And what we have noticed is that we use antibodies against these proteins and their fragments today.
00:15:27 Dr Ramchandran
Cheque them. Currently we are doing them with very traditional Western blotting methods to detect these proteins, but we are on our way to generate specific antibodies that would be used to detect them in a sort of a chip based format where we could put a.
00:15:44 Dr Ramchandran
A little bit.
00:15:45 Dr Ramchandran
Of blood or a little bit of fluid and then.
00:15:47 Dr Ramchandran
Have the chip with the.
00:15:48 Dr Ramchandran
Antibody specific to these ciliary.
00:15:50 Dr Ramchandran
Proteins and then you would.
00:15:51 Dr Ramchandran
Be able to get an answer whether the protein levels are high or low.
00:15:55 Dr Ramchandran
Which would perhaps inform the clinician or the care provider of an impending crisis or crisis that occurred where they’ve had an injury to the brain and suddenly they’re all their cells are disrupted in the city of proteins have gone up dramatically and then one could use.
00:16:15 Dr Ramchandran
That as a point of care test.
00:16:18 Will Mountford
It sounds like would be a very useful biomarker. I mean are there any plans to take that forwards in the near future? Like what’s the step between knowing what you know now and having that test available in clinics in hospitals for people in exactly those circumstances?
00:16:32 Dr Ramchandran
Yes, that is our very much our immediate plan. So what we want to now.
00:16:38 Dr Ramchandran
Do is we are in the phase where we need to collect patient samples with sort of brain injury for which is our focus.
00:16:46 Dr Ramchandran
And correlate these levels that we are seeing to a scan to see what was the extent of the injury when the values were a certain number.
00:16:56 Dr Ramchandran
So once we have that correlation, then one would be able to sort of incorporate these antibodies into an existing format.
00:17:05 Dr Ramchandran
Where one could sort of detect these in these.
00:17:09 Dr Ramchandran
Chips that I.
00:17:10 Dr Ramchandran
Talked about a few minutes ago.
00:17:12 Dr Ramchandran
So there are companies out there that have these chips and they have certain other proteins that they are looking at, but then we would think the ciliary proteins would be.
00:17:23 Dr Ramchandran
Added to that complement set of proteins and perhaps we could get a different set of information from solid footing then we could get from the other proteins and combined with these knowledge we could perhaps tailor the treatment.
00:17:35 Will Mountford
They mentioned the development and traumatic brain injuries cases when these will be knocked off and when they’ll be most readily did.
00:17:43 Will Mountford
Are there any other conditions where people should be aware that this could be a biomarker for the future? If there’s anything that can happen eventfully like traumatic brain injury or any lifelong conditions that this could be a complement to the care strategy there is at the moment in the future?
00:17:57 Dr Ramchandran
From the perspective of auxiliary loss, any disease condition where there is a flow component and a disruption of.
00:18:08 Dr Ramchandran
Flow is fair game.
00:18:10 Dr Ramchandran
So I would say that opens up the whole can of worms here. But I would say immediately I can think of preeclampsia, which is a which is a very important condition in pregnant women and with with sudden increase in hypertension.
00:18:26 Dr Ramchandran
Is a classic.
00:18:27 Dr Ramchandran
Area where we could see this develop.
00:18:28 Dr Ramchandran
That’s a biomarker.
00:18:30 Dr Ramchandran
Type general hypertension, any Atheros sclerosis, any areas where flow is compromised. So these are all areas where one could see an application we developed in, in our in our study we’ve also looked at.
00:18:45 Dr Ramchandran
Sickle cell disease, a disease where the red blood cells are sickle in shape and they seem to clog these different vasculature and these patients have these episodes of seizures.
00:18:56 Dr Ramchandran
Or we could perhaps detect in these patients their ciliary profile by looking at their red blood cells. So it turns out.
00:19:05 Dr Ramchandran
In these patients, the red blood cells carry silly fragments, which was unexpected because these red blood cells often interact the blood vessel wall.
00:19:14 Dr Ramchandran
Normally they flow right through the middle of the lumen, but in these patients they kind of bounce off the blood vessel wall and by doing so they are knocking off this cilia and Akuma.
00:19:23 Dr Ramchandran
Getting them. And so that could be another sort of application for these patients when they come in for routine checkups to see if their cerebral vasculature is about to leak and so on.
00:19:37 Dr Ramchandran
And maybe the sillitti profile could predict whether that’s going to happen or not in these patients. So there’s another.
00:19:44 Dr Ramchandran
Immediate applications we can see.
00:19:45 Will Mountford
Are there any conditions or regular biological processes that might confound silly detection like I’m thinking of just immune clearance if they’re getting swept up by immune cells, or if they are regenerating at such a rate that their loss is not readily detectable?
00:20:00 Will Mountford
Or I mean if they are being lost that they are replaced and there?
00:20:02 Will Mountford
00:20:03 Will Mountford
That much going wrong immediately, even if it’s a symptom of something to come later.
00:20:07 Dr Ramchandran
Sure, it’s possible that the immune system will begin to start to clear these silly proteins, but in some ways that is actually a good thing, because the level of selenoproteins dropping in a rapid fashion would be indication of a sort of going back to normalcy.
00:20:27 Dr Ramchandran
Indeed, the rapid clearance of the ciliated protein is an indication that system is coming back to returning back to normal, and so that’s actually not a bad thing. But.
00:20:36 Dr Ramchandran
A good thing.
00:20:37 Will Mountford
Is the regeneration of cilia something that could also be a therapeutic target, or something that could?
00:20:41 Will Mountford
Just be encouraged through adnot diet and exercise.
00:20:45 Dr Ramchandran
Yeah, well this is something that is conceptually an idea that is really plausible because we think that the ciliary regeneration, but this is a dynamic structure it it is formed in a cell and it gets broken down periodically and we believe that as one ages.
00:21:05 Dr Ramchandran
This process perhaps gets a little bit off the rails and so as the regeneration capacity goes down.
00:21:14 Dr Ramchandran
On the cellular regeneration capacity in this?
00:21:16 Dr Ramchandran
Case the cell.
00:21:17 Dr Ramchandran
Starts to lose some of its functional characteristics and gets weakened. And so on.
00:21:22 Dr Ramchandran
And and and that leads to perhaps.
00:21:24 Dr Ramchandran
Some long term issues.
00:21:27 Dr Ramchandran
And so yeah, I would imagine that no, if one could figure out a way to take some fruits or some diet changes.
00:21:35 Dr Ramchandran
That would keep reverse some of these cilia regeneration to baseline. Perhaps one could see a benefit.
00:21:43 Dr Ramchandran
To the health.
00:21:49 Dr Ramchandran
The immediate application of this new knowledge, which is the loss of ciliary proteins, can be detected upon change in flow.
00:21:58 Dr Ramchandran
It can be detected in blood as far reaching implications and as I mentioned from a brain injury or traumatic brain injury perspective.
00:22:07 Dr Ramchandran
This concept will allow people to make a decision on whether or not with the knowledge that their ciliary proteins are.
00:22:17 Dr Ramchandran
Are abruptly very high post injury, whether or not they are going to hopefully subject themselves to an LCD or an MRI scan.
00:22:29 Dr Ramchandran
And so that’s an immediate sort of decision tree there, whether you want to subject your child to that or not and secondly.
00:22:38 Dr Ramchandran
We are hoping that from our experiments we’ve already know that in preclinical models.
00:22:44 Dr Ramchandran
That the extent of injury.
00:22:47 Dr Ramchandran
Correlate through the amount of sillitti proteins that are in the blood. So what I mean by that is a mild injury.
00:22:55 Dr Ramchandran
You get less proteins, more injury, you a severe injury, you got more proteins. And so that would also predict whether somebody is going to have a.
00:23:07 Dr Ramchandran
Long term problems with cognitive deficits or cognitive decline or persistent concussion related symptoms and that might alter the course of treatment as well. So.
00:23:18 Dr Ramchandran
I would think that.
00:23:19 Dr Ramchandran
That our research will immediately benefit patients or undergoing brain injury and with the development of the biomarker test which we hope to incorporate via this, this chip where we can detect ciliary proteins will be immediately.
00:23:39 Dr Ramchandran
Translatable into point of care tests in the.
00:23:42 Dr Ramchandran
Like and so it’s a 15 minute test of the plasma and then you’d have results and hopefully less than 30 minutes and then you would be.
00:23:49 Dr Ramchandran
Off and running.
00:23:49 Dr Ramchandran
So that’s the immediate sort of benefit, I would say.
00:23:54 Dr Ramchandran
For patients who have had preeclampsia, their first pregnancy and maybe they want to have a second child and they’re worried about that.
00:24:02 Dr Ramchandran
Again, in their course of their next pregnancy, they may want to consider incorporating ASILIA biomarker test as a way to predict whether this episode of hypertension is going to occur when.
00:24:15 Dr Ramchandran
Is it going to occur?
00:24:17 Dr Ramchandran
And so it could be a sort of prognosticator of things to come in that population and that could be very beneficial for the clinician to know when they should take the next course of action and appropriate course of action and and again we think that.
00:24:32 Dr Ramchandran
I don’t want to say that Julia can stand alone as a readout for some of these things, but we we do believe that it can serve in a complement fashion to existing biomarkers in these fields and perhaps in some cases it could be a standalone as well. So it’s but these are all very active working.
00:24:52 Dr Ramchandran
I’m not aware of any clinical trials right now that patients can enrol in, but we are clearly looking for samples associated with these various conditions that I just described.
00:25:04 Dr Ramchandran
And if you are in part of an economic medical centre or you can clearly cheque with your local researchers.
00:25:12 Dr Ramchandran
And doctors and and if you’re interested, connect with us and we can also provide some code.
00:25:18 Dr Ramchandran
Attacks and from our own research perspective in the next month or so we have very exciting information that at least in the brain haemorrhage field we know that cilia is wenix expressed at a very specific time.
00:25:38 Dr Ramchandran
In the developing brain, and that is associated with vascular stability.
00:25:44 Dr Ramchandran
So that concept will really open up the field of cilia biology we believe, and also in conditions like paediatric intra ventricular haemorrhage. It’s the devastating condition that they really don’t have a whole lot of treatment options. We believe that the cilia.
00:26:05 Dr Ramchandran
And his detection and maybe restoration of cilia at a particular time in development would prevent the development of haemorrhage, and that, in our view, would be a quite satisfying outcome of our research.
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