Dicer1-miR-328-Bace1 signalling controls brown adipose tissue differentiation and function

Area of Science:

• Metabolic research
• Molecular biology
• Aging research

Background:

• Brown adipose tissue (BAT) activation is crucial for energy balance and a therapeutic target for obesity and type 2 diabetes.
• Ageing and obesity are associated with brown fat dysfunction, characterized by reduced microRNA levels due to decreased Dicer1 expression.

Purpose of the Study:

• To investigate the role of microRNAs, specifically miR-328, in brown fat differentiation and function.
• To explore the therapeutic potential of targeting the Dicer1-miR-328-Bace1 signaling pathway for metabolic disorders.

Main Methods:

• Analysis of microRNA expression during preadipocyte differentiation.
• Utilized mouse models including those with Dicer1 heterozygosity, progeria, longevity, and diet-induced obesity (DIO).
• Investigated the effects of modulating miR-328 and Bace1 (beta-secretase 1) in vitro and in vivo.

Main Results:

• Reduced Dicer1 expression in brown fat impairs glucose metabolism, particularly in diet-induced obesity.
• miR-328 regulates brown adipocyte differentiation; its overexpression promotes BAT differentiation and impairs muscle progenitor commitment by silencing Bace1.
• Loss of Bace1 enhances brown preadipocyte differentiation, and Bace1 inhibition in vivo improves glucose tolerance and insulin sensitivity in DIO mice.

Conclusions:

• The Dicer1-miR-328-Bace1 signaling axis is a key determinant of brown adipose tissue function.
• Inhibition of Bace1 presents a promising therapeutic strategy for age- and obesity-related metabolic dysfunction, with potential benefits for neurodegenerative diseases as well.