Project Abstracts - CTAR

Benjamin Glaser, MD, Investigator, Hadassah-Hebrew University                
Dana Avrahami-Tzfati, PhD, co-Investigator, Hadassah-Hebrew University  

Start Date: September 30, 2014

End Date: June 30, 2019

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Abstract

The prevalence of Diabetes Mellitus has reached epidemic proportions world-wide and is predicted to increase rapidly in the years to come, putting a tremendous strain on health care budgets in both developed and developing countries. There are two major forms of diabetes and both are associated with decreased beta-cell mass. No treatments have been devised that increase beta-cell mass in vivo in humans, and transplantation of beta-cells is extremely limited due to lack of appropriate donors. For these reasons, increasing functional beta-cell mass in vitro, or in vivo prior to or after transplantation, has become a “Holy Grail” of diabetes research. Our previous studies clearly show that adult human beta-cells can be induced to replicate, and – importantly – that cells can maintain normal glucose responsiveness after cell division. However, the replication rate achieved was still low, likely due in part to the known age-related decline in the ability of the beta-cell to replicate. W propose to build on our previous findings and to develop more efficacious methods to increase functional beta-cell mass by inducing replication of adult beta-cells, and by restoring juvenile functional properties to aged beta-cells. We will focus on mechanisms derived from studies of non- neoplastic human disease as well as age-related phenotypic changes in human beta-cells. In Aim 1, we will target the genes altered in patients with marked beta-cell hyperplasia, such as those suffering from Focal Hyperinsulinism of Infancy, Beckwith-Wiedemann Syndrome or Multiple Endocrine Neoplasia. Expression of these genes will be altered in human beta-cells via shRNA-mediated gene suppression and locus-specific epigenetic targeting. Success will be assessed in transplanted human islets by determination of beta-cell replication rate and retention of function. In Aim 2, we will determine the mechanisms of age-related decline in beta-cell function and replicative capacity, by mapping the changes in the beta-cell epigenome that occur with age. Selected genes will then be targeted as in Aim 1 to improve human beta-cell function, as assessed by glucose responsiveness. To accomplish these aims, we will use cutting-edge and emerging technologies that are already established or are being developed in our laboratories. The research team combines clinical experience with expertise in molecular biology and extensive experience in genomic modification aimed at enhancing beta-cell replication. By basing interventions on changes found in human disease and normal aging, this approach will increase the chances that discoveries made can be translated more rapidly into clinically relevant protocols.

Publications

• Glycemic control releases regenerative potential of pancreatic beta cells blocked by severe hyperglycemia
• Paternal Exercise Improves the Metabolic Health of Offspring via Epigenetic Modulation of the Germline
• Biphasic dynamics of beta cell mass in a mouse model of congenital hyperinsulinism: implications for type 2 diabetes
• Islet transplantation in the subcutaneous space achieves long-term euglycaemia in preclinical models of type 1 diabetes
• Single cell transcriptomics of human islet ontogeny defines the molecular basis of β cell dedifferentiation in T2D
• The dynamic methylome of islets in health and disease
• Everything in its right place: resident memory CD8+ T cell immunosurveillance of HIV infection
• Multiplexed In Situ Imaging Mass Cytometry Analysis of the Human Endocrine Pancreas and Immune System in Type 1 Diabetes
• Single-Cell RNA-Seq of the Pancreatic Islets–a Promise Not yet Fulfilled?
• Examining How the MAFB Transcription Factor Affects Islet β-Cell Function Postnatally
• Targeted demethylation at the CDKN1C/p57 locus induces human β cell replication
• GABA and Artesunate Do Not Induce Pancreatic α-to-β Cell Transdifferentiation In Vivo
• The Dysregulation of the DLK1-MEG3 Locus in Islets From Patients With Type 2 Diabetes Is Mimicked by Targeted Epimutation of Its Promoter With TALE-DNMT Constructs
• Postnatal DNA demethylation and its role in tissue maturation
• Overexpression of ST5, an activator of Ras, has no effect on β-cell proliferation in adult mice
• β-Cells are not uniform after all-Novel insights into molecular heterogeneity of insulin-secreting cells
• Beta cell heterogeneity: an evolving concept
• Pancreatic β-Cells Express the Fetal Islet Hormone Gastrin in Rodent and Human Diabetes
• High-fidelity Glucagon-CreER mouse line generated by CRISPR-Cas9 assisted gene targeting
• Epigenetic control of β-cell function and failure
• Epigenetic Analysis of Endocrine Cell Subtypes from Human Pancreatic Islets
• Single-Cell Mass Cytometry Analysis of the Human Endocrine Pancreas
• Single-Cell Transcriptomics of the Human Endocrine Pancreas
• The Genetic Program of Pancreatic β-Cell Replication In Vivo
• Integration of ATAC-seq and RNA-seq identifies human alpha cell and beta cell signature genes
• Aging-Dependent Demethylation of Regulatory Elements Correlates with Chromatin State and Improved β Cell Function
• The BisPCR(2) method for targeted bisulfite sequencing
• TALE-mediated epigenetic suppression of CDKN2A increases replication in human fibroblasts