Bornstein, S. | bioRxiv Science

bioRxiv2023

In vitro differentiation of mouse pluripotent stem cells into glucocorticoid-producing adrenocortical cells

Directed differentiation of pluripotent stem cells into specialized cell types represents an invaluable tool for a wide range of applications. Here, we have exploited single-cell transcriptomic data to develop a step-wise in vitro differentiation system from mouse embryonic stem cells into adrenocortical cells. We show that during development the adrenal primordium is embedded in an extracellular matrix containing tenascin and fibronectin. Culturing cells on fibronectin during differentiation increased the expression of the steroidogenic marker NR5A1. Furthermore, 3D cultures in the presence of PKA-pathway activators led to the formation of aggregates composed of different cell types expressing adrenal progenitor or steroidogenic markers, including the adrenocortical specific enzyme Cyp21a1. Importantly, in vitro differentiated cells secreted the zona Fasciculata specific corticosterone in response to cAMP activators, but not gonadal hormones, thus confirming the specificity of differentiation towards the adrenal lineage. HighlightsO_LIMouse adrenal progenitors differentiate in a tenascin/fibronectin-rich extracellular matrix C_LIO_LIStepwise differentiation of ES cells yields NR5A1+ adrenocortical cells C_LIO_LI3D aggregates produce glucocorticoids in response to cAMP signalling C_LI

developmental biology↗

bioRxiv2019

Islet macrophages drive islet remodeling and compensatory hyperinsulinemia in the early diabetes

{beta}-cells respond to peripheral insulin resistance by increasing circulating insulin in early type-2 diabetes (T2D). Islet remodeling supports this compensation but the drivers of this process remain poorly understood. Infiltrating macrophages have been implicated in late stage T2D but relatively little is known on islet resident macrophages, especially in early T2D. We hypothesize that islet resident macrophages contribute to islet vascular remodeling and hyperinsulinemia, the failure of which results in a rapid progression to T2D. Using genetic and diet-induced models of compensatory hyperinsulinemia we show that its depletion significantly compromises islet remodeling in terms of size, vascular density and insulin secretion capacity. Depletion of islet macrophages reduces VEGF-A secretion from both human and mouse islets ex vivo and the impact of reduced VEGF-A functionally translates to delayed re-vascularization upon transplantation in vivo. Hence, we show a new role of islet resident macrophages in the context of early T2D and suggest that there is considerable utility in harnessing islet macrophages to promote islet remodeling and islet insulin secretion capacity.\n\nHighlightsO_LIThe compensatory hyperinsulinemic phase of type-2 diabetes is accompanied with significant pancreatic islet remodeling.\nC_LIO_LIBona fide islet resident macrophages are increased during the diabetic compensation phase by largely in situ proliferation.\nC_LIO_LIAblating macrophages severely compromises the islet remodeling process and exacerbates glycemic control in vivo.\nC_LIO_LIMouse and human islet macrophages contribute VEGF-A to the islet environment.\nC_LIO_LISpecific removal of islet macrophages delays islet vascularization in compensatory hyperinsulinemic mice.\nC_LI

molecular biology↗