Intervertebral disc degeneration (IVDD) is a common cause of low back pain. Procyanidin C1 (PCC1) has been demonstrated to exert a protective effect on nucleus pulposus (NP) cells, and therefore, plays a critical role in the prevention and therapy of IVDD. Clarifying the pathophysiological characteristics and molecular mechanisms of IVDD may be helpful in establishing novel preventive and therapeutic strategies. This study aimed to investigate the probable mechanisms underlying the protection against acidic pH stress induced human NP cell injury. In vitro, acidic pH stress induced degeneration, mitochondrial dynamics imbalance, mitophagy, and mitochondria-mediated apoptosis in NP cells, all of which were ameliorated by PCC1. Autophagy inhibition partially eliminated the protective effects of PCC1 on mitochondrial homeostasis in NP cells. Moreover, PCC1 activated the sirtuin 3 (SIRT3)/forkhead box O3 (FOXO3) signaling pathway, a pivotal signaling pathway involved in the regulation of mitochondrial homeostasis in NP cells. In vivo, PCC1 ameliorated IVDD in a rat model and preserved the extracellular matrix of NP cells. Consequently, the protective effects of PCC1 on NP cells may inhibit IVDD progression via regulation of the SIRT3/FOXO3 signaling pathway. Therefore, regulation of the SIRT3/FOXO3 signaling pathway may be a novel preventive and therapeutic strategy for IVDD.
Copper (Cu) and zinc (Zn) are essential trace elements for terrestrial animals. Studies suggested that single dietary Cu- or Zn- deficiency lead to liver lipid deposition and cause metabolic dysfunction-associated steatotic liver disease (MASLD). However, the mechanisms by which dietary Cu and Zn co-deficiency promote hepatic lipid deposition and metabolism remain unknown. Our study found that, compared to single Cu- or Zn- deficiency, Cu and Zn co-deficiency significantly increased lipid deposition, induced mitochondrial oxidative stress, disrupted mitochondrial structure and function, and inhibited lipolysis in hepatocytes and whole liver tissue. Mechanistically, Cu and Zn co-deficiency-induced lipotoxicity was mediated by sirtuin 3 (Sirt3). Sirt3 inhibited the acetylation and degradation of forkhead box O3 (Foxo3), preventing its binding to the peroxisome proliferator-activated receptor alpha (PPARα) promoter, which accordingly increased lipid deposition. Overall, for the first time, we elucidated the mechanism by which Cu and Zn co-deficiency aggravates hepatic lipotoxicity and identified the critical regulatory role of the Sirt3/Foxo3/PPARα pathway during this process, with the fish as the model.
危险品化学品经营许可证（带存储）