BBS Faculty Member - Rohit Kulkarni

Rohit Kulkarni

Department of Cell Biology

Joslin Diabetes Center
Research, Room 410
One Joslin Place
Boston, MA 02215
Tel: 617-309-3460
Fax: 617-309-3476
Email: rohit.kulkarni@joslin.harvard.edu
Lab Members: 1 instructor, 7 postdoctoral fellows, 2 students, 1 lab manager, 1 research assistant



INTERROGATING GROWTH FACTOR (INSULIN/IGF-I) SIGNALLING PATHWAYS IN THE REGULATION OF ISLET CELL and HEPATIC BIOLOGY.

The Kulkarni Lab has a major investment in investigating the significance of growth factor (e.g. insulin and insulin like growth factor-1) signaling pathways in the modulation of glucose sensing of beta cells, proinsulin processing, mitochondrial function, protection against apoptosis and ER stress and in regulating the expression of transcription factors in islet cells. We create genetic models to examine the roles of insulin and IGF-1 and -2 receptors and their substrates (insulin receptor substrates; IRS-1,2,3,4) and proteins downstream (e.g. Akt, FoxO1, PDX-1) in islet biology. We use Cre-LoxP and Flp-Frt techniques to create islet-cell-specific knockout (or knockin) of multiple proteins to complement in vitro models using primary islets from humans and rodents and derived beta and alpha cell lines from the genetically engineered models. Using these powerful and unique reagents we are investigating cross-talk between insulin, IGF-I, glucose, incretin (glucagon like-peptide-1) and leptin signaling pathways in islet cells. A major effort is directed towards evaluating specificity of insulin versus IGF signaling and their substrates and their actions in the nucleus in islet cells and hepatocytes during embryonic and adult life. We are studying pathways utilized by lymphocytes that allow regeneration of beta cells. Recently we have focused our efforts on investigating dynamic modifications of RNA methylation in islet cells and hepatocytes in models of diabetes. These studies will advance the field on several fronts - first, it will provide greater insights into the fundamental physiology that governs the normal proliferation of the cell types and secretory function of the islets; second, it will provide a physiological basis to identify proteins that can be harnessed to design potential therapeutic strategies to prevent islet cell death and to plan alternative approaches to generate new beta cells to prevent and/or cure human type 1 and type 2 diabetes.

2. USING INDUCED PLURIPOTENT STEM CELLS TO INVESTIGATE CELL REGENERATION.

A second area of focus in the Kulkarni Lab is to derive induced pluripotent stem (iPS) cells from skin fibroblasts and/or blood cells derived from living human donors (MODY and type 1 and type 2 diabetes patients) and rodent models with the long term goal of differentiating them into mature islet cells. There is also a focus on differentiating iPS cells into cells that are targets for complications observed in patients with type 1 and type 2 diabetes (e.g. vascular endothelial cells, neuronal cells, kidney cells, retinal pericytes). These approaches allow us to generate unique cells that maintain the genetic make-up of the living individual that would otherwise be unavailable, with the potential for characterizing their signaling properties, and for screening drugs to identity the most effective medications for individual patients.

3. IDENTIFICATION OF CIRCULATING ISLET CELL GROWTH FACTORS.

We are using transplantation and parabiotic approaches and techniques that allow us to investigate inter-organ communication for the identification of circulating islet cell growth factors (e.g. between islets and liver or white/brown adipose). Identification of these putative factors have the potential for harnessing them into therapeutics to enhance functional beta cell mass to counter human type 1 and type 2 diabetes.



Last Update: 7/28/2017



Publications

For a complete listing of publications click here.

 


 

Valdez IA, Dirice E, Gupta MK, Shirakawa J, Teo AKK, Kulkarni RN. Proinflammatory cytokines induce endocrine differentiation in pancreatic ductal cells via STAT3-dependent Ngn-3-activation. Cell Reports 15(3):460-470, 2016. PMID:27068459;PMCID:PMC4838491

Mezza T, Shirakawa J, Martinez R, Hu J, Giaccari A,
Kulkarni RN. Nuclear export of FoxO1 is linked to ERK signaling in β-cells lacking insulin receptors. J Biol Chem 291:21485-21495, 2016 PMID:27535223; PMCID:PMC5076820

Teo AKK, Lau HH, Valdez I, Dirice E, Tjora E, Raeder H,
Kulkarni RN. Early developmental perturbations in a human stem cell model of MODY5/HNF1B pancreatic hypoplasia. Stem Cell Rep 6(3):357-367, 2016. PMID:26876668; PMCID:PMC4788763

El Ouaamari A, Dirice E, Gedeon N, Hu J, Zhou J-Y, Shirakawa J, Hou L, Goodman J, Karampelias C, Qiang G, Boucher J, Martinez R, Gritsenko MA, De Jesus DF, Kahraman S, Bhatt S, Smith RD, Beer H-D, Jungtrakoon, P, Gong Y, Goldfine AB, Liew CW, Doria A, Andersson O, Qian W-J, Remold-O’Donnell E,
Kulkarni RN. SerpinB1 promotes pancreatic β-cell proliferation. Cell Metabolism 23(1):194-205, 2016. PMID:26701651 PMCID:PMC4715773

Shirakawa T, Fernandez M, Takatani T, ElOuaamari A, Jungtrakoon P, Okawa E, Zhang W, Yi P, Doria A,
Kulkarni RN. Insulin signaling regulates the FoxM1-CENPA-PLK1 pathway to modulate adaptive β-cell proliferation. Cell Metabolism 25(4):868-882,e5, 2017. PMID:28286049; PMCID:PMC5382039

Kawamori D, Shirakawa J, Liew CW, Hu J, Morioka T, Duttaroy A, Burkey B,
Kulkarni RN. GLP-1 signaling compensates for impaired insulin signaling in regulating β-cell proliferation in βIRKO mice. Diabetologia 2017. doi.10.1007/s00125-017-4303-6. PMID:28526921



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