Our lab studies pancreas development and function, focusing on the role of the microenvironment in these processes.
Using in vivo mouse models, we focus on three main questions
How do mesenchymal cells regulate pancreas development in the embryo?
The pancreas comprises of various cell types that share common progenitors in the embryo. We showed that mesenchymal cells guide pancreas and beta-cell development, and are required to establish organ size and shape (Landsman et al., 2011). We further showed that mesenchymal cells dictate the ratio between pancreatic endocrine cell populations (Hibsher et al., 2016). Our findings facilitate cell replacement therapy for diabetes.
How do pericytes support beta-cell function and glucose regulation?
Insulin-producing beta-cells rely on their microenvironment for their functionality and mass. Pericytes, along with endothelial cells, make up the islets of Langerhans dense capillary network. We recently showed that pericytes promote beta-cell function and glucose-stimulated insulin secretion (Sasson, Rachi, Sakhneny, et al., 2016). Moreso, we found that in the neonatal pancreas, pericytes promote beta-cell proliferation (Epshtein et al., 2017). We now use transgenic mouse models to further define the pericyte/beta-cell axis and its requirement for glucose homeostasis.
Does abnormal pericyte function contribute to diabetes?
Impaired function of beta-cells is a critical factor in type 2 diabetes. We recently showed that TCF7L2, which confers a high genetic risk of type 2 diabetes through a yet to be described mechanism, is required for proper function of pancreatic pericytes. Inactivation of this transcription factor specifically in pancreatic pericytes leads to impaired glucose response due to impaired beta-cell function (Sakhneny et al., 2018). Our findings thus implicate abnormalities in the islet microenvironment as an underlying cause of diabetes.