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Published: Feb. 3, 2015, 1:15 a.m.

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Hello, and welcome to Episode Thirty of Multiple Sclerosis Discovery, the podcast of the MS Discovery Forum. I\u2019m your host, Dan Keller.

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This week\u2019s podcast features an interview with Dr. Seema Tiwari-Woodruff about estrogen in animal models of MS. But to begin, here\u2019s a brief summary of some of the latest developments on the MS Discovery Forum at msdiscovery.org.

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Last week, we reported on the results of another clinical trial for hematopoietic stem cell transplantation in relapsing-remitting MS. Compared to the \u201chalt-MS\u201d trial, which we reported on in January, this study used a less aggressive conditioning approach. Patients involved in the study demonstrated improvement in EDSS scores, and eighty percent of them were relapse-free at four years. The results raised important questions about how to prep MS patients for the transplant. Visit our \u201cNews and Future Directions\u201d section to read the full story.

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A recent study published in the Multiple Sclerosis Journal demonstrated a potential new way to monitor lesion repair using standard MRI techniques. Clinical trials usually look for new lesions in brain scans to monitor drug efficacy. Lead author, Daniel Reich, told MSDF it\u2019s more important than ever to be able to visualize changes in tissue since drug development is shifting towards neuroprotection and repair.

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We\u2019re also pleased to announce that Daniel Reich is one of two new members of our Scientific Advisory Board. Dr. Reich is the director of the Translational Neuroradiology Unit in the National Institute of Neurological Disorders and Stroke, part of NIH. Our other new board member is Deborah Backus, an expert on rehabilitation who is Director of Multiple Sclerosis Research at the Shepherd Center in Atlanta, Georgia. Read their full bios in our \u201cWho We Are\u201d section under the \u201cAbout Us\u201d tab.

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Now to the interview. Dr. Tiwari-Woodruff is an associate professor of biomedical sciences at the University of California, Riverside. She met with MSDF editor-in-chief, Bob Finn, to talk about her research on estrogen and multiple sclerosis.

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Interviewer \u2013 Robert Finn

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Dr. Tiwari-Woodruff, welcome.

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Interviewee \u2013 Seema Tiwari-Woodruff

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Thank you.

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MSDF

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So what is the connection between estrogen and MS?

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Dr. Tiwari-Woodruff

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It\u2019s an interesting connection between estrogen and MS, because estrogen is actually a part of life in a way that our brains require it, our bodies require it at every moment of our life, I should say. Many years ago it was found that relapsing-remitting patients had less relapses when they were pregnant, and the causes of that was potentially estrogens \u2013 high levels of them \u2013 or progesterone or vitamin D. Many researchers went ahead and looked at those high levels of pregnancy estrogens called estriol and found that high levels of estriol were the reason why these women patients had lower levels of MS symptoms.

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So eventually down the line, estrogens were parsed out of which estrogen was better. And it turns out that one type of estrogen, which is the estrogen of the alpha, is more immunomodulatory \u2013 it actually suppresses the immune response \u2013 and that is probably what makes MS symptoms better versus estrogens of the beta ligand was known not to have that much immunomodulatory effect; instead, it was actually directly neuroprotective. So estrogens of the alpha and beta both seem to have an effect on various cell types which are involved in multiple sclerosis.

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MSDF

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So if estrogen seems to be protective in pregnant women with MS, why not just use estrogen, or an analog like estriol or estradiol, as a treatment?

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Dr. Tiwari-Woodruff

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That\u2019s a very good question. And, first, these therapies were thought that we were going to use those first, and a lot of clinical trials were going through with that. But what happens with high levels of estrogen is there are two things which are important to know. One is they have a feminizing effect, and the second one is they have a preponderance for causing uterine cancer or breast cancer. So you don\u2019t want to stimulate those two types of cancer. So high levels of estrogen could be dangerous in that aspect. So that is why we don\u2019t want to use that as potential therapy.

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MSDF

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So you\u2019ve done a lot of work with a specific estrogen receptor agonist called indazole chloride. First, tell me how you came upon this compound.

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Dr. Tiwari-Woodruff

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So estrogens of the beta ligands are not just being looked at for multiple sclerosis, they were being looked at as a potential therapeutic for menopause \u2013 hot flashes included \u2013 rheumatoid arthritis, and other impairments like prostate cancer, etc. So there were quite a few chemists who were coming up with various different types of estrogen receptor beta ligands. So while I was doing my work with mouse models of MS in generic estrogen receptor beta ligand, which was the DPN \u2013 diarylpropionitrile \u2013 a study came out which was actually on indazole chloride which was developed by a chemist, John Katzenellenbogen; he\u2019s done a lot of work on developing these molecules. And this particular compound showed that it decreased activation of astrocytes and microglia; this was published in Cell a few years back. And we met at a meeting, John Katzenellenbogen and myself \u2013 we were giving a talk at the same time in a meeting in Stockholm \u2013 and we decided to talk to each other. And he said, \u201cYour research is very intriguing on estrogen receptor beta ligand, would you like to try this out?\u201d And that\u2019s how I got my hands on the indazole chloride. And we did some preliminary studies and showed good results. Then we decided to embark on a full-fledged study which was published in PNAS.

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MSDF

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So you used indazole chloride in two different mouse models of MS, and you used it both prophylactically and in mice that are already showing symptoms. What did you find?

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Dr. Tiwari-Woodruff

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So prophylactically when you use a compound, you are actually trying to see if you can inhibit the symptoms which are going to come up when you induce a disease, and that is all good. But when you are talking about patients who come to see the doctor, they\u2019re always coming in with symptoms, so they already have the disease ongoing. So the second paradigm where you give the drug when the disease symptoms are already there is closer to what humans are going to be able to see. So the nice thing about indazole chloride was that, prophylactically, definitely it made the mice better, but therapeutically also; they were able to decrease the disease symptoms by nearly 50%.

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MSDF

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What is the significance of the fact that it seems to work on two different mouse models of MS?

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Dr. Tiwari-Woodruff

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So when you\u2019re looking at a drug especially in a disease like multiple sclerosis which has two major components \u2013 one is inflammatory component and another one is a neurodegenerative component \u2013 if you can show that this drug is working in one way or both ways would be very useful for developing better drugs or better treatments. So what we did was when we treated the mice with indazole chloride, in one mouse model which is the experimental autoimmune encephalomyelitis which contains both the inflammatory and the neurodegenerative component, we saw a decrease in the disease symptoms. But we couldn\u2019t tell if the indazole chloride was working in the inflammatory component or the neurodegeneration component, because it showed effect on both.

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So we went to a second mouse model which is the toxic cuprizone diet model which doesn\u2019t have a primary inflammatory component. The disease starts with oligodendrocytes, the cells which make the myelin. They die when you feed this diet to the mice, so they have massive demyelination in regions of the brain. When we gave the drug during the remyelination phase, we found that indazole chloride was able to remyelinate the axons better when the drug was present versus when it was absent. So this actually showed us that indazole chloride has two arms to it. One, it inhibits the inflammatory component and the second, it inhibits the neurodegenerative component independent of the inflammatory component.

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MSDF

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Is it also sort of confirmatory? The EAE is not a perfect model of MS and neither is the cuprizone mouse model, but does it make you feel better that these two completely different models are showing similar effects?

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Dr. Tiwari-Woodruff

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Absolutely, you really hit the point where\u2026 We are always looking for the best model for multiple sclerosis, but because the disease is so complex no one model can be said that it\u2019s 100% mimicking multiple sclerosis. So for us to see that demyelination which occurs both in EAE and the cuprizone model was improved \u2013 we actually saw remyelination in both models \u2013 really gave us hope that this drug could be directly acting on oligodendrocytes which are forming the myelin, which is the cause of major mode of dysfunction in multiple sclerosis.

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MSDF

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So does indazole chloride help these mice a little bit, or does it help them a lot?

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Dr. Tiwari-Woodruff

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So that\u2019s a very good question. Similar to what you might see in the patient population, in the mouse model of MS, especially in the EAE model, the disease is not consistent. So the lesions which appear in the brain of EAE animals are very diverse, unlike the cuprizone model where the demyelination is very consistent. So when you\u2019re looking at these mice, especially in the EAE cohort, if the animal is really, really sick, you actually see the disease symptoms go down just a little bit. But if the animals were sick to the middle level, they actually showed a bigger difference, they showed better recovery. And we hypothesize that the axons which have been injured to the point of no return, if the axons have been demyelinated and injured, it doesn\u2019t matter now when you give them therapeutic drugs, these are not going to improve. So there are certain number of axons in the brain which drop out and we don\u2019t see recovery in those. But said that, overall we still saw a significant increase with indazole chloride treatment in both models.

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MSDF

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Have you done histology?

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Dr. Tiwari-Woodruff

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Yes. We\u2019ve done histology, we\u2019ve done electron microscopy. And we do one more thing my lab is very good at, we do electrophysiology. Because one of the things we always think is when you look at remyelination you can see myelin coming up, but is the myelin functional? If the axons can conduct faster or better, then you know that the myelin which has covered the axons is functional. So we do all three. And we also include behavioral testing. So one of the tests we included which a lot of people use is a Rota rod; it\u2019s a motor test to show that the mice can stay on the Rota rod much longer after treatment with indazole versus just the vehicle.

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MSDF

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Do you see any side effects?

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Dr. Tiwari-Woodruff

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So that\u2019s interesting. We did not see any side effects in these mice. Agreed, we treated them up to 60 days, we haven\u2019t treated them longer than that, plus we were giving them at a 5 mg/kg/day concentration. So we didn\u2019t see any kind of toxicity. But said that, we still need to do those studies in a thorough way before we can safely say that they had no side effects.

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MSDF

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So what\u2019s next in the development of indazole chloride as a potential MS treatment?

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Dr. Tiwari-Woodruff

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So indazole chloride is a good target. And while these studies were going on last year, John Katzenellenbogen and myself, we were talking about how are we going to proceed with this because we were seeing really good results; this is even before I published the paper. And he said what would you like to do? And one of the things we said was is it possible to make better analogs of this compound which are going to be more specific, could be used in a lower concentration and may have a better therapeutic outcome?

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So he came up with four analogs which he has sent to me, and we did some preliminary studies to see if they were toxic to cells in culture, because that\u2019s the first thing you do. And they have no toxicity in cells, they actually have shown to behave well with proliferation \u2013 depreciation of the cell \u2013 and we haven\u2019t seen more cell death or less cell death with them. So we are very excited about that. So coming next month, we are actually going to start treatment of EAE animals, and once that goes through the goal is to do toxicity studies on the two best compounds and see if we can find a company so we can have a backing on these drugs for potential human trials. It\u2019s a couple years from now, at least \u2013 it could be even more \u2013 but we are actually moving in that direction.

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MSDF

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Dr. David Baker in a commentary on his multiple sclerosis research blog seemed less than enthusiastic about indazole chloride. He suggested that many compounds seem to work similarly in mouse models. How do you respond to that criticism?

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Dr. Tiwari-Woodruff

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So Dr. Baker has a very good point on saying that there could be many compounds which are good in EAE but they fizzle out and they don\u2019t go up to clinical trial. I disagree on one point where it comes to indazole chloride, because we have precedence of estrogens showing good therapeutic indication in humans; there were clinical trials done in UCLA where they showed that there was improvement with estriol treatment. And estriol does target both ER-alpha and ER-beta \u2013 ER-beta a little more than ER-alpha \u2013 so I\u2019m very confident that what we are seeing with estrogen receptor beta is not a fluke. And because it\u2019s a steroid and a small molecule, it does not seem to have a lot of toxicity involved which could be somewhat which is brand new. So we\u2019ll see. I hope Dr. Baker\u2019s wrong and we do manage to get this drug to human patients and we see therapeutic efficacy in them.

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MSDF

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Dr. Baker also said that a critical experiment had not yet been done. And let me quote from his blog post. He said, \u201cThe development of demyelination should be allowed to occur after this damage has abated, then punitive remyelinating drugs should be given.\u201d How do you respond to that?

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Dr. Tiwari-Woodruff

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Very good point made by Dr. Baker, but I have actually addressed those in the PNAS paper. We part off particularly this aspect of the disease. So the prophylactic treatment was before the disease started; that is what he\u2019s mentioning in the blog. The second part is what is important where EAE disease was induced, and after peak disease had occurred we gave the drug, indazole chloride. At the peak disease, we actually see increased inflammation, but alongside with that we see demyelination and axon degeneration. So the damage has already started. The drug treatment after that is what caused the disease to get better. We saw increased conduction, we saw increased remyelination, and less axon damage.

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Similar to that, we also did the experiment in cuprizone. The treatment paradigm was as such: We actually had nine week of demyelination ongoing in the cuprizone model, which is very chronic; it\u2019s chronically ongoing where you have quite a bit of damage of the axons and you have acute demyelination. During the remyelination phases where we gave the drug either to one group and vehicle to the other group, what we saw was that the drug treatment, indazole chloride, actually increased remyelination and decreased axon damage. So I think Dr. Baker was trying to make a point on we haven\u2019t done the right experiment, but I think we have done the right experiment. And further research with indazole chloride will let us know if this is a good drug or not.

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MSDF

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Dr. Tiwari-Woodruff, is there anything you\u2019d like to add?

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Dr. Tiwari-Woodruff

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I would like to add one more thing. We have actually looked at indazole chloride in optic neuritis \u2013 EAE-induced optic neuritis \u2013 and we are going to be publishing a paper fairly soon showing that in optic neuritis we see less inflammation in the retina and increased remyelination in the optic nerve. So I\u2019m very confident that it\u2019s not just a phenomenology in one part of the brain which we picked last time \u2013 it was the corpus callosum \u2013 that we see increased remyelination and decreased damage caused by EAE with treatment of indazole chloride.

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MSDF

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Well, thank you very much.

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Dr. Tiwari-Woodruff

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Thank you.

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Thank you for listening to Episode Thirty of Multiple Sclerosis Discovery. This podcast was produced by the MS Discovery Forum, MSDF, the premier source of independent news and information on MS research. MSDF\u2019s executive editor is Robert Finn. Msdiscovery.org is part of the non-profit Accelerated Cure for Multiple Sclerosis. Robert McBurney is our President and CEO, and Hollie Schmidt is vice president of scientific operations.

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Msdiscovery.org aims to focus attention on what is known and not yet known about the causes of MS and related conditions, their pathological mechanisms, and potential ways to intervene. By communicating this information in a way that builds bridges among different disciplines, we hope to open new routes toward significant clinical advances.

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We\u2019re interested in your opinions. Please join the discussion on one of our online forums or send comments, criticisms, and suggestions to editor@msdiscovery.org.

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