mtDNA Haplogroup N9a Increases the Risk of Type 2 Diabetes by Altering Mitochondrial Function and Intracellular Mitochondrial Signals.

Mitochondrial DNA (mtDNA) haplogroups have been associated with the incidence of type 2 diabetes (T2D); however, their underlying role in T2D remains poorly elucidated. Here, we report that mtDNA haplogroup N9a was associated with an increased risk of T2D occurrence in Southern China (odds ratio 1.999 [95% CI 1.229-3.251], P = 0.005). By using transmitochondrial technology, we demonstrated that the activity of respiratory chain complexes was lower in the case of mtDNA haplogroup N9a (N9a1 and N9a10a) than in three non-N9a haplogroups (D4j, G3a2, and Y1) and that this could lead to alterations in mitochondrial function and mitochondrial redox status. Transcriptome analysis revealed that OXPHOS function and metabolic regulation differed markedly between N9a and non-N9a cybrids. Furthermore, in N9a cybrids, insulin-stimulated glucose uptake might be inhibited at least partially through enhanced stimulation of ERK1/2 phosphorylation and subsequent TLR4 activation, which was found to be mediated by the elevated redox status in N9a cybrids. Although it remains unclear whether other signaling pathways (e.g., Wnt pathway) contribute to the T2D susceptibility of haplogroup N9a, our data indicate that in the case of mtDNA haplogroup N9a, T2D is affected, at least partially through ERK1/2 overstimulation and subsequent TLR4 activation.

Oncogenic HSP60 regulates mitochondrial oxidative phosphorylation to support Erk1/2 activation during pancreatic cancer cell growth.

HSP60 is a mitochondrial localized quality control protein responsible for maintaining mitochondrial function. Although HSP60 is considered both a tumor suppressor and promoter in different types of cancer, the role of HSP60 in human pancreatic ductal adenocarcinoma (PDAC) remains unknown. In this study, we demonstrated that HSP60 was aberrantly expressed in human pancreatic cancer tissues and cell lines. Analysis of the Cancer Genome Atlas database revealed that HSP60 expression is positively correlated with pancreatic cancer. Further, knockdown of HSP60 attenuated pancreatic ductal cancer cell proliferation and migration/invasion, whereas ectopic expression of HSP60 increased tumorigenesis. Using an in vivo tumorigenicity assay, we confirmed that HSP60 promoted the growth of pancreatic ductal cancer cells. Functional analyses demonstrated that HSP60 plays a key role in the regulation of mitochondrial function. Mechanistically, both HSP60 knockdown and oxidative phosphorylation (OXPHOS) inhibition by metformin decreased Erk1/2 phosphorylation and induced apoptosis and cell cycle arrest, whereas Erk1/2 reactivation with EGF promoted cell proliferation. Intriguingly, in vitro ATP supplementation partially restored Erk1/2 phosphorylation and promoted proliferation in PDAC cells with HSP60 knockdown and OXPHOS inhibition. These results suggest that mitochondrial ATP is an important sensor of Erk1/2 regulated apoptosis and the cell cycle in PDAC cells. Thus, our findings indicate for the first time that HSP60 may serve as a novel diagnostic target of human pancreatic cancer, and that inhibition of mitochondrial function using drugs such as metformin may be a beneficial therapeutic strategy targeting pancreatic cancer cells with aberrant function of the HSP60/OXPHOS/Erk1/2 phosphorylation axis.

Risk factors for postoperative pancreatic fistula: Analysis of 170 consecutive cases of pancreaticoduodenectomy based on the updated ISGPS classification and grading system.

This study was designed to analyze the risk factors for postoperative pancreatic fistula (POPF) after pancreaticoduodenectomy (PD).Between September 2015 and August 2017, 170 successive patients underwent a radical PD in the Department of Pancreatic Surgery, Union Hospital, Wuhan. We carried out a retrospective study of these cases and the prospective conditions, which might be related to POPF, were examined with univariate and multivariate analysis. POPF was defined as a drain output of any measurable volume of fluid with an amylase level more than 3 times the upper limit of serum amylase activity on postoperative day 3, accompanied by a clinically relevant condition according to the 2016 update of the International Study Group for Pancreatic Surgery (ISGPS) definition. In our study, the POPF was just referred to as grade B and grade C pancreatic fistula in accordance with the ISGPS consensus, because the former grade A pancreatic fistula is now redefined as a biochemical leak, namely no-POPF, which has no clinical impact and needs no other special therapy.Pancreatic fistula occurred in 44 (25.9%) patients after PD, with a mean length of hospital stay of 24.98 ±â€Š14.30 days. Thirty-six patients (21.2%) developed grade B pancreatic fistula, and 8 patients (4.7%) had grade C pancreatic fistula. Among patients with grade C pancreatic fistula, 4 patients died, 3 patients were operated on again, and 3 patients developed multiple organ failure.Univariate analysis showed a significantly important association between POPF and the following factors: pancreas texture (soft vs hard: 39.1% vs 10.3%, P < .0001) and fasting blood glucose level (<108.0 mg/dL vs ≥108.0 mg/dL: 32.5% vs 12.5%, P = .005). Multivariate logistic regression analysis identified 2 independent factors related to POPF: soft pancreas texture and fasting blood glucose level <108.0 mg/dL.A soft pancreas and a fasting blood glucose level of <108.0 mg/dL are risk factors for the development of a POPF.