Perilipin 2 Protects against Lipotoxicity-Induced Islet Fibrosis by Inducing Islet Stellate Cell Activation Phenotype Changes.

Aims: We explored whether and how perilipin 2 () protected islets against lipotoxicity-induced islet dysfunction by regulating islet stellate cells (ISCs) activation.

Methods: Six-week-old male rats were given a high-fat diet or a control diet for 28 weeks. Glucose metabolic phenotypes were assessed using glucose/insulin tolerance tests, masson, and immunohistochemical staining. ISCs activation levels were assessed from rats and palmitic acid- (PA-) treated cultured ISCs by immunofluorescence, Oil red O staining, electron microscopy, quantitative PCR, and western blotting. Changes in ISCs phenotype of activation degree and its underlying mechanisms were assessed by target gene lentiviral infection, high-performance liquid chromatography (HPLC), and western blotting.

Results: Obese rats showed glucose intolerance, decreased endocrine hormone profiles, and elevated expression of -smooth muscle actin (-SMA), a polygonal appearance without cytoplasmic lipid droplets of ISCs in rats and isolated islets. PA-treated cultured ISCs exhibited faster proliferation and migration abilities with the induction of mRNA levels of lipid metabolism proteins, especially . The overexpression of resulted in ISCs "re-quiescent" phenotypes associated with inhibition of the Smad3-TGF- signaling pathways.

Conclusions: Our observations suggest a protective role of in weakening ISCs activation. It may serve as a novel therapeutic target for preventing islet fibrosis for T2DM.