Matrix metalloproteinase inhibition impairs murine adipose tissue development independently of leptin

Area of Science:

• Biochemistry
• Physiology
• Pharmacology

Background:

• Leptin deficiency in ob/ob mice leads to obesity.
• Matrix metalloproteinases (MMPs), particularly gelatinases, play roles in tissue remodeling and development.
• The role of MMPs in adipose tissue development, especially in the context of leptin deficiency, requires further investigation.

Purpose of the Study:

• To investigate the effect of MMP inhibition on body weight and adipose tissue development in leptin-deficient mice.
• To determine if MMP inhibition impacts adipocyte size, vascularization, and collagen content in adipose tissue.
• To explore whether MMP inhibition can reduce adiposity independently of leptin.

Main Methods:

• Administration of Tolysam (MMP inhibitor) to leptin-deficient (ob/ob) mice on a high-fat diet for 15 weeks.
• Assessment of body weight, food intake, physical activity, and body temperature.
• Analysis of subcutaneous (SC) and gonadal (GON) fat pad weights, adipocyte morphology, blood vessel density, and collagen content via zymography and Sirius red staining.

Main Results:

• Tolysam treatment significantly reduced body weight gain and overall body weight.
• Reduced SC and GON fat mass were observed in Tolysam-treated mice.
• MMP-2 activity was decreased, accompanied by mild adipocyte hypotrophy and reduced blood vessel density in adipose tissues.
• Collagen content and organization in adipose tissue remained comparable between treated and control groups.

Conclusions:

• Gelatinase inhibition using Tolysam effectively reduced body and fat pad weights in leptin-deficient mice.
• MMP inhibition appears to impair adipose tissue development, leading to reduced adiposity and adipocyte size.
• These findings suggest that MMP inhibition may be a potential therapeutic strategy for obesity, acting independently of leptin signaling.