Cholesterol can be a causative factor in Type 2 diabetes, revealed by scientists at Canada’s Vancouver Child and Family Research Institute.
The study was based at Canada’s Vancouver Child and Family Research Institute at the University of British Columbia, and is published online in Nature Medicine.
Type 2 diabetes is characterized by both peripheral insulin resistance and reduced insulin secretion by -cells. The reasons for -cell dysfunction in this disease are incompletely understood but may include the accumulation of toxic lipids within this cell type.
Researchers examined the role of Abca1, a cellular cholesterol transporter, in cholesterol homeostasis and insulin secretion in -cells. Mice with specific inactivation of Abca1 in -cells had markedly impaired glucose tolerance and defective insulin secretion but normal insulin sensitivity. Islets isolated from these mice showed altered cholesterol homeostasis and impaired insulin secretion in vitro.
Researchers found that rosiglitazone, an activator of the peroxisome proliferator?activated receptor-, which upregulates Abca1 in -cells, requires -cell Abca1 for its beneficial effects on glucose tolerance.
These experiments establish a new role for Abca1 in -cell cholesterol homeostasis and insulin secretion, and suggest that cholesterol accumulation may contribute to -cell dysfunction in type 2 diabetes.