Inhibition of mitochondrial complex I improves glucose metabolism independently of AMPK activation

Abstract

Accumulating evidences showed metformin and berberine, well‐known glucose‐lowering agents, were able to inhibit mitochondrial electron transport chain at complex I. In this study, we aimed to explore the antihyperglycaemic effect of complex I inhibition. Rotenone, amobarbital and gene silence of NDUFA13 were used to inhibit complex I. Intraperitoneal glucose tolerance test and insulin tolerance test were performed in db/db mice. Lactate release and glucose consumption were measured to investigate glucose metabolism in HepG2 hepatocytes and C2C12 myotubes. Glucose output was measured in primary hepatocytes. Compound C and adenoviruses expressing dominant negative AMP‐activated protein kinase (AMPK) α1/2 were exploited to inactivate AMPK pathway. Cellular NAD +/NADH ratio was assayed to evaluate energy transforming and redox state. Rotenone ameliorated hyperglycaemia and insulin resistance in db/db mice. It induced glucose consumption and glycolysis and reduced hepatic glucose output. Rotenone also activated AMPK. Furthermore, it remained effective with AMPK inactivation. The enhanced glycolysis and repressed gluconeogenesis correlated with a reduction in cellular NAD +/NADH ratio, which resulted from complex I suppression. Amobarbital, another representative complex I inhibitor, stimulated glucose consumption and decreased hepatic glucose output in vitro, too. Similar changes were observed while expression of NDUFA13, a subunit of complex I, was knocked down with gene silencing. These findings reveal mitochondrial complex I emerges as a key drug target for diabetes treatment. Inhibition of complex I improves glucose homoeostasis via non‐AMPK pathway, which may relate to the suppression of the cellular NAD +/NADH ratio.

Inhibition of mitochondrial complex 1 by the S6K1 inhibitor PF-4708671 partly contributes to its glucose metabolic effects in muscle and liver cells

“…In L6 muscle cells, the ability of PF to enhance glucose uptake was partially reversed by stable NDI1 expression, indicating that the decrease of mitochondrial complex 1 activity contributes to the stimulatory effect of the compound on muscle glucose uptake. This conclusion is also supported by previous studies showing that inhibition of mitochondrial complex 1 by a very low dose of rotenone or siRNA-mediated silencing of NADH:Ubiquinone Oxidoreductase Subunit A13, a subunit of complex I, can reduce hepatic glucose production and stimulate glucose consumption in muscle cells, independently of AMPK (28). In addition, other studies have reported similar mechanisms.…”

“…(NADH:ubiquinone oxidoreductase) plasmid was a gift from David Sabatini (Addgene plasmid #72876) and the pMXS-control vector was kindly provided by Kivanc Birsoy (Rockefeller University, USA). Plasmids were amplified as previously described in Phoenix-Eco cells (ATCC #CRL-3214) (28). Undifferentiated rat L6 myoblasts were infected with the amplified retrovirus and selected with 5 µg/ml of blasticidin to generate L6-pMXS and L6-NDI1 stably transfected myoblasts.…”

Utilizing Synergistic Potential of Mitochondria-Targeting Drugs for Leukemia Therapy

“…Interestingly, both IACS/VIN and RT/2-DG combinations significantly enhanced ECAR (extracellular acidification rate) by 27-234% in MOLM-13 cells and studied patient samples (n = 5/6), as well as in PBMCs in case of IACS/VIN (Table S8). Previous reports have shown that inhibiting Complex I of the ETC with IACS-010759 or rotenone upregulates glucose consumption and glycolysis (42,43). As expected, normalized coupling efficiency was also significantly associated (r = 0.786, p < 0.001) with ATP-linked OCR ( Figure 7E).…”

Sennoside A induces GLP-1 secretion through activation of the ERK1/2 pathway in L-cells

“…Cell viability was measured using the cell counting kit -CCK8 assay Kit(Dojindo, Japan)(n = 6/group). The percentage of living cells was calculated as previously described in a study [16].…”