Short Wave - Why The Bladder Is Number One!

Episode Date: September 29, 2022

When's the last time you thought about your bladder? We're going there today! In this Short Wave episode, Emily talks to bladder expert Dr. Indira Mysorekar about one of our stretchiest organs: how it can expand so much, the potential culprit behind recurrent urinary tract infections and the still-somewhat-mysterious link between the aging brain and the aging bladder. --------------------------------------------------------------------Our third birthday is coming up on October 15th and we want your voice on our show! Send us a voice recording with your name, where you're located, a one-sentence birthday wish, and this exact sentence: "You're listening to Short Wave, from NPR." E-mail it to us at [e-mail] and we may put it at the top of one of our birthday shows. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

Mark your calendars, everyone. Shortwave's third birthday is coming up, October 15th. Our team is in the audio kitchen baking up a bunch of birthday episodes that will drop that week, and we want your voice on the show. Whether you've been with us since day one or the gravity well of our show has sucked you in anew. Here's what I'd love. Use a voice recording app on your phone, any recording device really, and make a short memo. Say your name, where you're located, a one-sentence birthday wish, and this exact same. sentence. You're listening to Shortwave from NPR. Email it to us at shortwave at npr.org. Thanks so much. Love You're listening to Shortwave from NPR. When you think of your bladder, what do you imagine? A blob in your belly. Just another organ competing for your attention. Friends, your beautiful bladder is so much more than a

storage room for pee. Think about how often it speaks to you. Multiple times a day. Multiple times a day. from the moment we are born until we die. That's Dr. Indira, my sorker, a urinary bladder expert. And she beseeches us to behold the bladder for what it is. A powerful, dynamic balloon. So, you know, it has the dome, which is the upper part, the rounded part. And then, as you know, a balloon tapers into a little cone that opens out into the outside. And that's pretty much how your bladder it looks like when it's full of urine.

And when it is not full, what does it look like? It looks like a parachute that's collapsed on the ground after you've arrived safely on the ground. And if you think about it, this highly specialized organ deserves way more respect. For starters, it has to be watertight. So our kidneys are filtering our blood and keeping all the good stuff. And then all the waste products are sent down into the bladder where they're collected and store as urine. And our bladders are made of smooth. muscle. So unlike skeletal muscles, think biceps, glutes, calf muscles, bladders are

stretchy. It maintains this stretchability to be able to expand multiple sizes over when it's storing urine and then releasing it and then doing it in a controlled fashion. So buckle up, don't squish the bladder, because we're going to take a little tour of this organ that is keeping it together for you more than you may realize. We'll investigate how it's so stretchy. why it's so smart, and how to keep it happy for life. I'm Emily Kwong, and you're listening to Shortwave, the LA Science podcast from NPR. So, Dr. Mysor, the bladder is this amazing organ. It keeps all of these waste products from leaking out into our bodies.

And it's doing this, like, dance of stretch, contract, stretch, contract all day. Related to this stretching, I came across a term called mechanotransduction. What is that? Just simply put, mechanotransduction is feeling a stretch. feeling a pressure, right? And so the bladder senses that it's being stretched. That's how information is sent back to the brain or the brain sends signals back to the bladder, like, okay, you can keep stretching even a little bit more, or now you have to stop, or now you have to go. So mechanotransduction means our ability to sense our fullness. And the muscles that allow us to do that,

say more about that. So the bladder has only smooth muscle. It has basically three layers. of smooth muscle cells. There's two layers on the outskirts of long muscle cells. And then in the center are a little circular bundles. And then together or rather in tandem, they work to allow us to stretch when the bladder is filling and then contract when the bladder is voiding. It's called the detruser muscle. And once again, with age and with childbirth, the activity of the detruser can be affected. Is there an example of like a cell in the bladder that you find particularly cool whose life and legacy you're interested in? Oh gosh, yes. Yes. One of my favorite set of cells in the bladder are the urethelial cells or urethelial umbrella cells.

Urethelial cells. Yes, urethelial. So the epithelium is basically the lining of the bladder. And these are barrier cells of the bladder. So they are critical for normal bladder function because they essentially block transfer of any waste products from the urine back into the bloodstream. And the second thing they're also critical for bladder function is the stretching. And these umbrella cells, they are one of the largest cells in the human body.

So the reason they're big is, because then these clamshell like things come up to the surface and open, and then the bladder can stretch. So they sense when everything is stretched to the max, and that's how you know you're full and you have to go. And then when you do go, then all these clamshell containing these proteins go back inside and get recycled and then new proteins get made.

This aspect changes with age. Infections are already pretty common, and early in life, and then get worse, especially in postmenopausal people. And many years ago when I was a trainee, a student, I actually had shown that Europathogenic E. coli, which are the bacteria, the bad bugs that cause UTIs predominantly, they are able to form reservoirs inside our bladder cells, these same umbrella cells. So they can actually hide inside our bladder cells. And while they're there, of course, you know, they escape all kinds of scrutiny from our immune system because they're invisible.

These reservoirs can come back out and cause a recurrent infection. So this was actually quite a paradigm shift at the time because it suggested that the bladder itself could be a source of recurrent infections. So in your research on urinary tract infections, what was kind of the dominant thinking about how they happened? And what did your research? find? So the dominant thinking has always been that every UTI is caused by exposure to bacteria that live in our colones and our intestines. And this was also used to explain why people with vaginas are much more likely to have UTIs because the space between the urethra, the vaginal opening, and the anal opening are so close together. And that still remains the case. But

My research showed that the bladder itself could harbor these reservoirs. So the bacteria can basically take up residence in your bladder and just keep reinfecting you? Exactly. That just seems unfair. And I totally. And guess what? As people age, these spots where the bacteria can hide increase significantly. So we think, and we haven't proven this yet, but we think that it's not a coincidence.

that, you know, people who get multiple recurrent UTIs and more frequent UTIs have many more reservoirs inside their bladders. So given your research, you are proposing a more multimodal approach to treating UTIs. How is that different from the course of antibiotics that people normally pursue? We've learned so much more. So if it's an acute infection, you treat it with antibiotics, sure, we have that. But, you know, if there's pain, you treat that. And if a person is older, you take that into consideration.

And you treat the bacteria. You treat the bladder cells. You treat the immune cells. You treat the pain, the connection with the brain and so on and so forth. So that way, you actually holistically improving bladder health for people. Another way getting older changes our relationship to our bladders is through our brains, the brain-bladder-connected. The older we get, the more dysfunction can arise. We need more research to identify ways to support the aging bladder.

And that includes conditions you might not ordinarily associate with it, like Alzheimer's and Parkinson's disease. But many of the changes that occur in our brain cells during conditions like Alzheimer's and Parkinson's actually also occur in our bladder cells. And that is a big area of research in my own research group, we understand how the cells of the bladder that line where the urine is, basically, those cells undergo significant changes with age that are very similar to what happens in our brain cells. And the muscle cells that we discussed in a second also undergo age-associated

processes that are, you know, at a molecular level or cellular level, as we say, are similar to what's happening in our brain cells. Wow, that just, it really shows how the bladder is not hanging out on an island all by itself. It's connected to so many other parts of our body, so many other organs. And the thing that's fascinating, fascinating in older postmenopausal people, like, you know, 85 plus in nursing homes, this has been observed and reported on that if they don't have any dementia normally, And if they start acting like they have dementia symptoms, they become forgetful and they don't know where they are and a lot of confusion and delirium, then people know that within 24 hours they're going to test positive for a urinary tract infection. And that connection is so interesting.

Like how are those two related? I think that's a huge question in the field to be able to really understand and dissect. the brain-bladder connection. The possibility of an evidence-based bladder treatment future is pretty thrilling. I think when people think about bladder health, you know, we should be drinking water. We should definitely go when we need to go and not be holding it. If there was one piece of advice you could give to people to show love to their bladder, what would it be?

And what do you want people to know about the bladder and why they should show it love at all? Sure. If we can't go or go all the time or leak, it has pretty devastating consequences for our lives. Even if it's not deadly like cancer, we don't die from this. But, you know, decades of pain and discomfort is pretty awful and very poor quality of life. So, so yes, definitely keep yourself hydrated, you know, do your Kegel exercises to keep your... Help that pelvic floor. Muscle, pelvic floor, keep your pelvic floor strong, especially those who have given birth. But leaky bladders or inability to go or difficulty avoiding completely and everything is something that pretty much every person faces as they get older. So this is something that goes into health care, normal health care and maintenance. Reducing stress that also helps. And then talk to your doctors.

talk to your Congress people to invest more research in the lower urinary track because it's a fairly neglected area. And then finally, a lot of things that are happening in our aging brain are also happening in our aging bladder. So I think the more we understand, the better we can treat our bodies and be healthier overall. Dr. Mysortoker, thank you so much for coming on to give the bladder its flowers. They're long overdue. Thank you so much for having me. This episode was produced by Burley McCoy.

It was edited by Gabriel Spitzer and fact-checked by Britt Hansen. The audio engineer was Josh Newell. Chazelle Grayson is our senior supervising editor. Brendan Crump is our podcast coordinator. Our senior director of programming is Beth Donovan. And the senior vice president of programming is Anya Grunman. I'm Emily Kwong. You're listening to Shortwave, the Daily Science Podcast from NPR.