Sprouty1 Prevents Cellular Senescence Maintaining Proliferation and Differentiation Capacity of Human Adipose Stem/Progenitor Cells

Area of Science:

• Cellular Biology
• Molecular Biology
• Aging Research

Background:

• The role of Ras-Mitogen-activated protein kinase (MAPK) signaling in cellular aging is not fully understood.
• Sprouty1 (SPRY1) was previously identified as a weight-loss target gene crucial for adipogenesis in human adipose stem/progenitor cells (ASCs).

Purpose of the Study:

• To investigate the function of Sprouty1 (SPRY1) in regulating cellular senescence and proliferation in human ASCs.
• To elucidate the mechanism by which SPRY1 loss impacts MAPK signaling and adipogenesis.

Main Methods:

• CRISPR/Cas9 genome editing was used to create Sprouty1 knockout (SPRY1 KO) human ASCs.
• Analysis included cell cycle arrest assessment, senescence-associated β-galactosidase staining, DNA damage markers, heterochromatin foci, p53, p21Cip1, Retinoblastoma (Rb) protein, NFκB and C/EBPβ activation, and IL-8/CXCL1 secretion.
• Adipogenesis assays were performed on senescent SPRY1 KO ASCs.

Main Results:

• SPRY1 KO ASCs exhibited hyper-activated MAPK signaling, irreversible cell cycle arrest, and a senescence phenotype.
• SPRY1 deficiency led to DNA double-strand breaks, increased senescence-associated heterochromatin foci, and induction of p53 and p21Cip1.
• SPRY1 KO induced a senescence-associated secretory phenotype (SASP) with elevated IL-8 and CXCL1, and abrogated adipogenesis.

Conclusions:

• Sprouty1 (SPRY1) plays a critical role in preventing cellular senescence in human ASCs.
• Loss of SPRY1 results in MAPK hyper-activation, senescence induction, and impaired adipogenesis.
• This study reveals SPRY1 as a novel regulator preventing senescence and maintaining the proliferative and differentiation capacity of human ASCs.