LYRM1, a novel gene promotes proliferation and inhibits apoptosis of preadipocytes.

Objective: To characterize a novel gene, Homo sapiens LYR motif containing 1 (LYRM1), that is highly expressed in omental adipose tissue of obese subjects.

Methods And Results: RT-PCR and western blot analysis confirmed that both mRNA and protein levels of LYRM1 were higher in omental adipose tissue of obese subjects than in normal weight subjects. RT-PCR analysis demonstrated that LYRM1 expression is widely distributed, with the highest levels of expression occurring in adipose tissue. A fusion protein of LYRM1 and green fluorescent protein as well as western blot analysis were used to identify the subcellular localization of LYRM1 in the nucleus. Based on Oil red O staining and the expression profile of specific differentiation markers, ectopic LYRM1 expression was not found to significantly affect adipogenesis. MTT assays and cell cycle analysis showed that LYRM1 promotes preadipocyte proliferation, and data from annexin V-FITC and caspase-3 activity assays further determined that LYRM1 can inhibit apoptosis of preadipocytes.

Conclusions: By increasing cell proliferation and lowering the rate of apoptosis, LYRM1 has the potential to modulate the size of the preadipocyte pool and influence adipose tissue homeostasis.