The most common metabolic diseases, such as type 2 diabetes or fatty liver disease leading to metabolic dysfunction-associated steatohepatitis (MASH), a fibrotic condition of the liver, are consequences of the dysfunctional state of metabolism that results from being overweight and sedentary. These conditions are rare in thin, fit people, even in later life when the damage of aging makes metabolism more vulnerable and inflammatory. Excess visceral fat tissue is known to promote the accumulation of senescent cells. While cells become senescent throughout life, in youth they are promptly cleared by the immune system. That clearance falters with age, allowing senescent cells to linger and accumulate. The metabolic dysfunction produced as a consequence of being overweight accelerates this process.
In today's open access paper researchers review what is known of the bidirectional relationship between metabolic dysfunction and the burden of senescent cells. Metabolic dysfunction promotes senescence, and in turn the inflammatory secretions of senescent cells further disrupt the operation of metabolically active tissues such as the liver. While a fair number of companies are presently developing senolytic drugs capable of clearing a meaningful fraction of senescent cells from the body, and while cheap first generation senolytic treatments, such as the dasatinib and quercetin combination, are readily available for anyone willing to put in a little effort to obtain them, metabolic disease is fairly low on the research and development communities' priority list. It seems unlikely that clinical trials will take place any time soon, but an increasing number of people are choosing to use senolytics off-label, an option that unfortunately generates very little solid data on whether or not a therapy is effective in any given use case.
Metabolically Active but Dysfunctional: The Impact of Senescent Cells and SASP
Cellular senescence and its secretory phenotype (SASP) have emerged as important contributors to chronic inflammation and metabolic dysfunction across multiple tissues. In adipose tissue, a combination of telomere attrition, oxidative stress, and pro-inflammatory signals pushes preadipocytes and mature adipocytes into premature senescence. These senescent adipocytes secrete a complex SASP, rich in cytokines, chemokines, and matrix-remodeling enzymes, that perpetuates local "metaflammation," impairs insulin signaling, and promotes systemic lipotoxicity.
In the liver, hepatocyte and stellate cell senescence similarly contribute to the progression of steatosis to MASH and cirrhosis, as SASP factors drive fibrosis, immune cell infiltration, and metabolic reprogramming. In the pancreas and skeletal muscle, senescence undermines β-cell function and glucose uptake, respectively, further exacerbating insulin resistance and hyperglycemia. Collectively, the cumulative burden of senescence and chronic SASP underscores a feed-forward cycle: metabolic stress induces senescence, and persistent SASP amplifies tissue dysfunction and accelerates disease progression.
Despite the protective role that acute, transient senescence can play in wound healing and tumor suppression, the accumulation of senescent cells in aged or obese individuals creates a pathogenic SASP milieu, often termed "inflammaging", that underlies obesity, type 2 diabetes, MASLD/MASH, and related cardiometabolic disorders. In rodent models, reducing senescent-cell marker burden has been associated with improved metabolic parameters, reduced fibrosis, and improved insulin sensitivity. These findings suggest translational potential for senotherapy in metabolic disease, although whether it can delay or reverse disease onset in humans remains to be established.
View the full article at FightAging
