Osteopontin-driven T-cell accumulation and function in adipose tissue and liver promoted insulin resistance and MAFLD

OBJECTIVE

This study investigated the contribution of osteopontin/secreted phosphoprotein 1 (SPP1) to T-cell regulation in initiation of obesity-driven adipose tissue (AT) inflammation and macrophage infiltration and the subsequent impact on insulin resistance (IR) and metabolic-associated fatty liver disease (MAFLD) development.

METHODS

SPP1 and T-cell marker expression was evaluated in AT and liver according to type 2 diabetes and MAFLD in human individuals with obesity. The role of SPP1 on T cells was evaluated in Spp1-knockout mice challenged with a high-fat diet.

RESULTS

In humans with obesity, elevated SPP1 expression in AT was parallel to T-cell marker expression (CD4, CD8A) and IR. Weight loss reversed AT inflammation with decreased SPP1 and CD8A expression. In liver, elevated SPP1 expression correlated with MAFLD severity and hepatic T-cell markers. In mice, although Spp1 deficiency did not impact obesity, it did improve AT IR associated with prevention of proinflammatory T-cell accumulation at the expense of regulatory T cells. Spp1 deficiency also decreased ex vivo helper T cell, subtype 1 (Th1) polarization of AT CD4+ and CD8+ T cells. In addition, Spp1 deficiency significantly reduced obesity-associated liver steatosis and inflammation.

CONCLUSIONS

Current findings highlight a critical role of SPP1 in the initiation of obesity-driven chronic inflammation by regulating accumulation and/or polarization of T cells. Early targeting of SPP1 could be beneficial for IR and MAFLD treatment.

Therapeutic Physical Exercise Programs in the Context of NASH Cirrhosis and Liver Transplantation: A Systematic Review

In recent years, various physical exercise interventions have been developed with a view to reducing comorbidity and morbidity rates among patients with chronic diseases. Regular physical exercise has been shown to reduce hypertension and mortality in patients with type 2 diabetes. Diabetes and obesity are often associated with the development of nonalcoholic fatty liver disease, which can lead to liver fibrosis and then (in some cases) nonalcoholic steatohepatitis cirrhosis. We searched the literature for publications on personalized physical exercise programs in cirrhotic patients before and after liver transplantation. Eleven studies in cirrhotic patients and one study in liver transplant recipients were included in the systematic review, the results of which were reported in compliance with the preferred reporting items for systematic reviews and meta-analyses guidelines. The personalized physical exercise programs lasted for 6 to 16 weeks. Our review evidenced improvements in peak oxygen consumption and six-minute walk test performance and a reduction in the hepatic venous pressure gradient. In cirrhotic patients, personalized physical exercise programs improve quality of life, are not associated with adverse effects, and (for transplant recipients) might reduce the 90-day hospital readmission rate. However, none of the literature data evidenced reductions in the mortality rates before and after transplantation. Further prospective studies are needed to evaluate the benefit of long-term physical exercise programs in cirrhotic patients before and after liver transplantation.