Hepatocyte growth factor regulates neovascularization in developing fat pads.

Area of Science:

• Cell Biology
• Developmental Biology
• Endocrinology

Background:

• Adipose tissue development is a complex process involving preadipocyte proliferation, differentiation, and vascularization.
• Hepatocyte growth factor (HGF) is a signaling molecule implicated in various cellular processes, including cell growth, migration, and angiogenesis.

Purpose of the Study:

• To investigate the role of hepatocyte growth factor (HGF) secreted by preadipocytes in regulating fat pad development and neovascularization.
• To determine the long-term consequences of stable HGF silencing on adipose tissue growth and vascular structure.

Main Methods:

• Generation of a clonal 3T3-F442A preadipocyte cell line with stable silencing of HGF expression using lentiviral-delivered shRNA.
• Assessment of fat pad size, vascularization (TIE1 and PECAM1 gene expression), and preadipocyte differentiation in vivo following injection of HGF-silenced or control preadipocytes.
• Evaluation of fat pad development after knockdown of the HGF receptor, c-MET.

Main Results:

• Stable silencing of HGF in preadipocytes led to a significant reduction in HGF mRNA and secretion.
• Fat pads derived from HGF-silenced preadipocytes were significantly smaller than control fat pads at all measured time points (days 3, 7, and 14).
• HGF knockdown impaired the development of contiguous vascular structures and attenuated preadipocyte differentiation, while c-MET knockdown showed different effects on vasculature and differentiation.

Conclusions:

• Preadipocyte-secreted HGF is a critical regulator of neovascularization in developing fat pads.
• HGF signaling is essential for promoting both vascular development and the differentiation of preadipocytes into mature adipocytes.
• Targeting HGF or its receptor may offer therapeutic strategies for modulating adipose tissue development and vascularization.