Islet Pericytes Are Required for β-Cell Maturity.

Islet cells depend on their surrounding environment to maintain function and quantity. Blood vessels in islets include endothelial cells and pericytes. Much is known about how endothelial cells support islet cells. But the role of pericytes remains unclear. This uncertainty drives the need for focused investigation. Prior studies have not fully addressed pericyte involvement. Researchers have not yet determined if pericytes influence β-cell behavior. This gap motivates a closer look at pericyte-β-cell interactions. Understanding these interactions may reveal new insights into islet function.

This study aimed to explore the role of pericytes in β-cell function. The researchers wanted to determine if pericytes influence β-cell maturity. They focused on whether pericytes support β-cell gene expression. The motivation came from the lack of data on pericyte contributions. The study tested the hypothesis that pericytes affect β-cell behavior. They used a mouse model to remove pericytes and observe effects. The goal was to assess β-cell function in the absence of pericytes. This approach allowed them to isolate the role of pericytes directly.

The team used a transgenic mouse system to remove pericytes. Diphtheria toxin was used to deplete pericytes selectively. They analyzed islets from these mice for changes in β-cell function. Isolated islets were tested for insulin content and gene expression. They measured glucose-stimulated insulin secretion in vitro. The researchers compared gene expression before and after pericyte removal. They focused on transcription factors like MafA and Pdx1. This method allowed them to assess pericyte effects directly.

Islets without pericytes showed lower insulin content and expression. Glucose-stimulated insulin secretion was impaired in these islets. Gene expression of β-cell markers was reduced in the absence of pericytes. Levels of MafA and Pdx1 were significantly decreased in pericyte-depleted islets. These findings suggest β-cell dedifferentiation occurred. Ex vivo pericyte depletion led to similar gene expression changes. The results support a direct role for pericytes in β-cell function. These effects were independent of blood flow or vascular changes.

The study suggests pericytes are essential for β-cell maturity. Pericyte removal leads to reduced β-cell function and gene expression. These findings point to a role for pericytes in islet niche support. The results indicate that pericytes maintain β-cell identity. Dedifferentiation appears to occur when pericytes are absent. The effects observed were not due to vascular changes alone. This study highlights the importance of pericytes in islet biology. The findings may help explain β-cell dysfunction in type 2 diabetes.