中年发福能逆转吗？《Science》重磅揭示：衰老致脂肪细胞激增5倍，全面拉高健康风险！

Core Viewpoint - The article discusses a recent study published in Science that reveals the underlying biological mechanisms contributing to abdominal fat accumulation in middle-aged individuals, particularly focusing on a specific type of fat cell that becomes more active with age [5][10]. Group 1: Mechanisms of Fat Accumulation - The study indicates that the increase in abdominal fat in middle-aged individuals is primarily due to the generation of new fat cells rather than the enlargement of existing ones, challenging the previous belief that fat cell numbers remain constant after adulthood [7]. - Researchers found that a specific subgroup of fat precursor cells, known as CP-A, significantly increases in number and activity in middle-aged mice, accounting for 34.23% of the visceral white adipose tissue [8][10]. - The proliferation and differentiation capabilities of CP-A cells are four times greater than those of another type of precursor cell, CP-1, indicating that CP-A plays a crucial role in the accumulation of visceral fat in middle age [9]. Group 2: Role of LIFR in Fat Cell Generation - The study identifies LIFR (leukemia inhibitory factor receptor) as a key gene that is highly expressed in CP-A cells and is associated with aging and fat generation [12]. - Inhibition of LIFR using a specific inhibitor (EC359) resulted in a 60% reduction in fat generation from CP-A cells, while having minimal effect on CP-1 cells, highlighting the dependency of CP-A on LIFR signaling [15]. - The activation of the JAK-STAT3 signaling pathway by LIFR is crucial for the proliferation and fat-generating capabilities of CP-A cells, suggesting that targeting LIFR could be a potential strategy to mitigate abdominal fat accumulation in middle-aged individuals [15].