BenU Faculty since 2007
Ph.D. – Physiology, University of Illinois at Chicago, IL (1999)
M.Phil – Crystallography and Biophysics, University of Madras, India (1991)
M.S. – Biophysics, University of Madras, India (1990)
B.S. – Physics, University of Madras, India (1988)

Courses Taught
Undergraduate Level
BIOL 258 – Human Physiology
BIOL 259 – Human Physiology Lab
BIOL 391 – Pathophysiology: Special topics
BIOL 340 – Cell Biology
BIOL 150 – Biology of Women

Graduate Level
EXPH 591/HLSC 392 – Exercise Biochemistry
EXPH 560/NUTR 560/HLSC 360 – Advanced Cardiovascular and Respiratory Physiology

Awards and Recognitions:
Dean’s Award for Teaching Excellence by an Adjunct Faculty 2010

Publications
Books/Chapters Published

1. Integrated Systems Physiology: Intestinal Absorption and Secretion by Rao, MC, Sarathy J, and Ao M, Publisher: Morgan and Claypool Life sciences, NJ. e-Book.
2. Venkatasubramanian J, Rao MC, and Sellin JH. Intestinal electrolyte absorption and secretion in Sleisenger and Fordtran’s Gastrointestinal and Liver Disease: Pathophysiology, Diagnosis, Management, 9th edition, Chapter 99, (2010).

Papers Published (Graduate and undergraduate students and Research Specialists mentored are italicized)

1. Anantamongol U, Ao M, Sarathy J (nee Venkatasubrmanian), Devi S, Krishnamra N, and Rao MC. Prolactin and Dexamethasone Regulate Second Messenger-Stimulated Cl− Secretion in Mammary Epithelia. Journal of Signal Transduction, Volume 2012 (2012), Article ID 192142, 15 pages. doi: 10.1155/2012/192142.
2. Ao M, Venkatasubramanian J, Ganesan Syed, Benya RV and Rao MC. Lubiprostone Activates Cl Secretion by Increasing CFTR in Apical Membrane in the Human Colon Carcinoma Cell Line, T84, Digestive Diseases in Science, 2011, 56(2):339-51.
3. Liu H, Singla A, Ao M, Gill RK, Venkatasubramanian J, Rao MC, Alrefai WA, Dudeja PK. Calcitonin Receptor-Mediated CFTR Activation in Human Intestinal Epithelial Cells J Cell Mol Med.; 2011; 10.1111/j.1582-4934.
4. Venkatasubramanian, J., Ao, M., and Rao M.C. Ion transport in the small intestine – Current Opinions    Gastroenterology, 2010 Mar;26(2):123-8.
5. Maria A Carlos, Chimnoya Nwagwu, Mei Ao, J Venkatasubramanian, Roli Prasad, Shamim Khan Chowdhury, Dharmapuri Vidyasagar, Mrinalini C Rao, Epidermal Growth Factor (EGF) stimulates chloride transport in primary cultures of weanling and adult rabbit colonocytes, Journal of Pediatric Gastroenterology and Nutrition, 44: 300-311, 2007.
6. Prasad, R., Venkatasubramanian, J., Amde, M., and Rao, M.C. Phospholipase C and src tyrosine kinases mediate neurotensin-stimulated Cl- secretion in rabbit proximal colon. Digestive Disease Sciences 49:1318-1326, 2004.
7. Venkatasubramanian, J., Nataraja, S. G., Carlos, M., Skaluba, S., Rasenick, M.M.R. and Rao, M. C. Differences in calcium signaling underlie age-specific effects of secretagogues on colonic chloride transport, 2001, American Journal Physiology: Cell Physiology, 280, 646-658. (Among Top 50 most read paper in month of Oct 2008)
8. Venkatasubramanian, J., Sahi, J., and Rao, M.C. Ion transport during growth and differentiaton, 2000, Annals of New York Academy of Sciences, 915, 357-372.
9. G. N. Desai, J. Sahi, P. M. Reddy, J. Venkatasubramanian, D. Vidyasagar, M. C. Rao., Chloride transport in primary cultures of rabbit colonocytes at different stages of development, 1996, Gastroenterology; 111, 1541-1550.

Peer-reviewed Abstracts

1. *Ao M, Sarathy J (nee Venkatasubramanian), Domingue J, Mathew J, Alrefai WA, Rao MC, ^Contributed equally, Chenodeoxycholic Acid (CDCA) Stimulates Cl- Secretion Across the Apical Membrane of Human Colonic Epithelial Cells, T84, via cAMP Signaling and Increases in the Phosphorylation of CFTR., May 2012, Poster Presentation in Digestive Diseases Week, San Diego
2. *J Sarathy (nee Venkatasubramanian), M Ao, J Syed, W. A Alrefai, MC Rao, Bile acid-induced Cl secretion involves cytoskeleton and activation of CFTR in colonic epithelial cells, T84., May 2011, Poster Presentation in Digestive Diseases Week, Chicago.

Research Area
My research interests are to elucidate, at a molecular level, the processes that modulate ion transport across epithelial cells. Epithelia, such as those lining the gastrointestinal tract, are multi-faceted and complex. For example, salt and water transport along the length of the intestine needs to be tightly regulated for normal function, and aberrations can result in some of the most devastating forms of diarrhea in a variety of species. Regulation of ion and water transport is also important in the mammary epithelia and aid with milk secretion. Therefore, studying the cellular and molecular regulation of ion transport by hormones, chemicals and drugs is important in defining fundamental physiological processes of fluid absorption and secretion, which can pertain to epithelial cells from mammalian mammary to the colonic epithelial cells. Model systems such as the human colon carcinoma cell-line (T84 cells) and mouse mammary epithelial cells (HC11) are used in these studies.

Current Research Projects

• Does bile acid modulate tight junction to increase paracellular permeability? Cells will be grown on inserts to form a monolayer, challenged with various doses of bile acid. Transepithelial resistance will be measured using anelectrical resistance system and paracellular permeability measured via mucosal to basolateral flux of 10-kDa fluorescence tagged dextran.
• Is the drop in resistance due to cytotoxic effects of bile acids? This will be assessed by measuring lactate dehydrogenase activity in the supernatant of cells treated with various doses of bile acids. Cytotoxicity is indicated if the LDH activity is increases in the solution. This is measured using a colorimetric assay.

Jayashree Sarathy, Ph.D.
Associate Professor, Biological Sciences
[email protected]

Rationale
High colonic bile acids and perturbations to the colonic microbiome play a role in pathogenesis of diarrheal diseases in ~1% of the population and probiotic supplements are commonly used to ameliorate these adverse symptoms. One of the research goals in the Sarathy lab is to identify the specific processes involved in bile acid-associated diarrhea (BAD).

Previous studies
We have studied the yin-yang in bile acid action using the human colonic epithelial cells, T84, and previously reported that the primary bile acid, chenodeoxycholic acid (CDCA; 500μM), altered the pore and leak functions of tight junction (TJ) and increased paracellular permeability while its secondary derivative, lithocholic acid (LCA; 50μM), did not. Further, CDCA action involves apoptosis, reactive

oxygen species generation, and release of proinflammatory cytokine IL-8. We then studied the effects of probiotic strains in Up & UpTM extra strength supplement containing 30 billion CFUs of Bifidobacterium and Lactobacillus strains on bile acid -induced dysfunction in human colonic epithelial cells, T84. We found that probiotics ± LCA ameliorated CDCA-induced apoptosis, oxidative stress (Faseb J, 36, S1, R5817, 2022) cytokine release, barrier disruption and increase in paracellular permeability (to be presented in April 2023) in T84 cells.

Understanding the role of probiotics in alleviating BAD

How is the supplement able to alleviate the symptoms? A primary mode by which probiotics have their beneficial effects in treating inflammatory diarrhea is via microbial metabolism of substrates to produce intermediate or end product metabolites. Thus, our hypothesis is that the protection provided by probiotics against CDCA’s deleterious effects is due to the bacterial alteration of CDCA into a benign intermediate.

This Summer, we will study the metabolites that may be derived from microbial conversion of bile acids. Particularly, we will study if CDCA structure may be modified or if it will be enzymatically broken down by the probiotic. There are other studies that have shown the role for the metabolites in exacerbating or alleviating symptoms in patients with inflammatory bowel disease1. Further, recent studies by Foley et al, 2021, have shown that probiotic Lactobaccilus strains use enzymes such as hydrolases to manipulate bile acids in the gut to promote their own survival2. Since our supplement has a predominance of L. bacillus, we will also study if bile acids alter the growth of the microbial strains in the probiotic supplement.

Project 1: To study the crosstalk between BA and microflora

Probiotic strains in Up & Up extra strength supplement (B. bacterium and L. bacillus strains; 30 billion CFUs) will be grown in T84 epithelial cell culture media ± CDCA± LCA under anaerobic conditions at 37°C. Up and Up extra strength probiotic supplement is a commercially available mixture (Manufacturer: Target) consisting of the following eight bacterial species: Streptococcus thermophilus, Bifidobacterium breve, Bifidobacterium longum, Bifidobacterium infantis, Lactobacillus acidophilus, Lactobacillus plantarum, Lactobacillus paracasei, and Lactobacillus delbrueckii subsp. Bulgaricus. A total of 4.5 × 1011 probiotic bacteria will be dissolved in 50 ml media and grown in T84 culture media in the presence or absence of bile acids. We have shown previously that the bacterial strains do grow in epithelial cell culture media.

1) Identify if the microbial species are altered in the presence of different bile acids

Project 2: To study the effect of probiotics on bile acid composition

This part of the study will be done in collaboration with Dr. Narayanan, the biochemist in our College of Science and Health. The expertise of Sarathy lab in bile acid physiology and that of Dr. Narayanan in biochemical assays and HPLC use will help bring this project to fruition. The results of these studies will shed light on the interaction of microbiome,

bile acids and intestinal epithelia. Studies from our lab will contribute to understanding the mechanisms by which probiotics restore barrier integrity will help identify novel therapeutic strategies to target symptoms in patients with bile acid-associated diarrhea.

Project 3: Determine the effect of probiotics ± bile acids on mucin production in T84 cells

There are several studies that show the importance of microbiota in maintaining epithelial barrier integrity. Supplements, such as Up and Up brands of probiotic formula, have been shown to alleviate symptoms in patients with inflammatory bowel disease (IBD). Although we have shown the disruptive effects of excess bile acids on colonic cell monolayers, we have to remember that the colonic cells in vivo have the mucin layer and microbiota which can help protect the epithelial layer form harmful molecules and pathogens. Though there are many studies on the beneficial effects of microbiome, much remains to be identified on how the microbiome interfaces with the protective mucous layer of the colon. The colonic T84 cells have been shown to secrete mucin in culture (McCool et al, Biochem J, 1990, 267) which could be stimulated by calcium secretagogues (Forstner et al, AJP-GI, 1993, 264). MUC-2 has been shown to be more abundant in epithelial cells of intestine. We and others have previously shown that bile acids increased [Ca2+]i, and we will study the effect of CDCA, and LCA on mucin production ± probiotics. Conditioned media have been shown to be more effective in inducing mucin expression.

Method: Therefore, in this study we will expose T84 cells apically to CM and qPCR and Western blotting will be used to analyze MUC2 gene and MUC-2 protein expression, respectively, in response to bile acids ± increasing concentrations of CM. A minimum of 4 wells of T84/treatment group will be assayed.