Putative role of uncoupling proteins in mitochondria-nucleus communications and DNA damage response

Mitochondria-nucleus communications and DNA damage response (DDR) play roles in cellular stress and closely associate with a range of diseases. Mitochondrial uncoupling proteins (UCPs) are capable of uncoupling mitochondrial oxidative phosphorylation and protecting against oxidative stress. However, the potential role of UCPs in DDR and DDR-related mitochondria-nucleus communications remains unknown. The review deduces UCPs functions in mitochondria-nucleus communications implicated in metabolite regulation (e.g., reactive oxygen species) and Ca²⁺ signaling, and in DDR (e.g., base excision repair, double-strand DNA break repair, mitophagy and nuclear DNA degradation). Represented are shared microRNAs that regulate UCPs and DDR. It would provide novel insight into UCPs-mediated mitochondria-nucleus communications and DDR, and potentially promote drug target identification, drug discovery and clinical therapy of DDR-related diseases.

Mitochondrial uncoupling has no effect on microvascular complications in type 2 diabetes

Diabetic peripheral neuropathy (DPN), diabetic kidney disease (DKD), and diabetic retinopathy (DR) contribute to significant morbidity and mortality in diabetes patients. The incidence of these complications is increasing with the diabetes epidemic, and current therapies minimally impact their pathogenesis in type 2 diabetes (T2D). Improved mechanistic understanding of each of the diabetic complications is needed in order to develop disease-modifying treatments for patients. We recently identified fundamental differences in mitochondrial responses of peripheral nerve, kidney, and retinal tissues to T2D in BKS-db/db mice. However, whether these mitochondrial adaptations are the cause or consequence of tissue dysfunction remains unclear. In the current study BKS-db/db mice were treated with the mitochondrial uncoupler, niclosamide ethanolamine (NEN), to determine the effects of mitochondrial uncoupling therapy on T2D, and the pathogenesis of DPN, DKD and DR. Here we report that NEN treatment from 6-24 wk of age had little effect on the development of T2D and diabetic complications. Our data suggest that globally targeting mitochondria with an uncoupling agent is unlikely to provide therapeutic benefit for DPN, DKD, or DR in T2D. These data also highlight the need for further insights into the role of tissue-specific metabolic reprogramming in the pathogenesis of diabetic complications.