NADH Dehydrogenase Activity Research Articles

Modifications of the respiratory chain of Bacillus licheniformis as an alkalophilic and cyanide-degrading microorganism.

Bacillus licheniformis can use cyanide as a nitrogen source for its growth. However, it can also carry out aerobic respiration in the presence of this compound, a classic inhibitor of mammalian cytochrome c oxidase, indicating that B. licheniformis has a branched respiratory chain with various terminal oxidases. Here, we studied the modifications in the respiratory chain of B. licheniformis when cells were cultured in Nutrient Broth, an alkaline medium with ammonium, or an alkaline medium with cyanide. Then, we measured oxygen consumption in intact cells and membranes, enzyme activities, carried out 1D and 2D-BN-PAGE, followed by mass spectrometry analysis of BN-PAGE bands associated with NADH, NADPH, and succinate dehydrogenase activities. We found that cell growth was favored in a nutrient medium than in an alkaline medium with cyanide. In parallel, respiratory activity progressively decreased in cells cultured in the rich medium, alkaline medium with ammonium, and the lowest activity was in the cells growing in the alkaline medium with cyanide. B. licheniformis membranes contain NADH, NADPH, and succinate dehydrogenases, and the proteomic analysis detected the nitrate reductase and the bc, caa3, aa3, and bd complexes. The succinate dehydrogenase migrated with a molecular mass of 375kDa, indicating its association with the nitrate reductase (115kDa + 241kDa, respectively). The NADH dehydrogenase of B. licheniformis forms aggregates of different molecular mass.

Olduvai domain expression downregulates mitochondrial pathways: implications for human brain evolution and neoteny.

Encoded by the NBPF gene family, Olduvai (formerly DUF1220) protein domains have undergone the largest human lineage-specific copy number expansion of any coding region in the genome. Olduvai copy number shows a linear relationship with several brain size-related measures and cortical neuron number among primates and with normal and disease-associated (micro- and macrocephaly) variation in brain size in human populations. While Olduvai domains have been shown to promote proliferation of neural stem cells, the mechanism underlying such effects has remained unclear. Here, we investigate the function of Olduvai by transcriptome and proteome analyses of cells overexpressing NBPF1 , a gene encoding 7 Olduvai domains. Our results from both RNAseq and mass spectrometry approaches suggest a potential downregulation of mitochondria. In our proteomics study, a Gene Ontology (GO) enrichment analysis for the downregulated proteins revealed a striking overrepresentation of the biological process related to the mitochondrial electron transport chain ( p value: 1.81e-11) and identified deregulation of the NADH dehydrogenase activity ( p value: 2.43e-11) as the primary molecular function. We verify the reduction of apparent mitochondria via live-cell imaging experiments. Given these and previous Olduvai findings, we suggest that the Olduvai-mediated, dosage-dependent reduction in available energy via mitochondrial downregulation may have resulted in a developmental slowdown such that the neurogenic window among primates, and most extremely in humans, was expanded over a greater time interval, allowing for production of greater numbers of neurons and a larger brain. We further suggest that such a slowdown may extend to other developmental processes that also exhibit neotenic features.

Cucumeropsis mannii seed oil (CMSO) restores testicular mitochondrial dysfunctions by modulating the activities of dysregulated testicular mitochondrial enzymes in male albino rats exposed to bisphenol A.

Bisphenol A, a traditional endocrine disruptor, has been implicated in male infertility. This study investigated the effect of Cucumeropsis mannii seed oil (CMSO) on bisphenol A (BPA)-induced biochemical toxicity in the testicular mitochondria of male albino rats. The rats were assigned randomly to six experimental groups (n = 6), A, B, C, D, E, and F. Group A received 1 mL of olive oil. Groups B and C received 100 mL/kg body weight (BW) of BPA and 7.5 mL/kg BW CMSO, respectively. Rats in groups D, E, and F received preadministered doses of 100 mL/kg BW of BPA, 5 mL/kg BW of BPA, and 2.5 mL/kg BW of CMSO, respectively, followed by 6 weeks of exposure to those doses. Some mitochondrial enzymes, mitochondrial membrane potential (MMP), mitochondria testicular protein, and body weight of rats were determined using standard methods. BPA significantly reduced succinate dehydrogenase, malate dehydrogenase, isocitrate dehydrogenase, NADH dehydrogenase, and monoamine oxidase activity. Also, BPA prominently decreased the MMP, mitochondrial testicular protein, and body weight of rats. Interestingly, coadministration of BPA and CMSO restored the dysregulated activities of the enzymes and levels of other biomarkers. We postulated that CMSO may be a promising drug for treating systemic toxicity caused by environmental toxicants such as BPA.

Exposure to 6-PPD quinone causes damage on mitochondrial complex I/II associated with lifespan reduction in Caenorhabditis elegans

N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine quinone (6-PPDQ) is an emerging pollutant transformed from 6-PPD. However, the effect of 6-PPDQ exposure on mitochondrion and underlying mechanism remains largely unclear. Using Caenorhabditis elegans as animal model, exposed to 6-PPDQ at 0.1–10 μg/L was performed form L1 larvae to adult day-1. Exposure to 6-PPDQ (1 and 10 μg/L) could increase oxygen consumption rate and decease adenosine 5′-triphosphate (ATP) content, suggesting induction of mitochondrial dysfunction. Activities of NADH dehydrogenase (complex I) and succinate dehydrogenase (complex II) were inhibited, accompanied by a decrease in expressions of gas-1, nuo-1, and mev-1. RNAi of gas-1 and mev-1 enhanced mitochondrial dysfunction and reduced lifespan of 6-PPDQ exposed nematodes. GAS-1 and MEV-1 functioned in parallel to regulate 6-PPDQ toxicity to reduce the lifespan. Insulin peptides and the insulin signaling pathway acted downstream of GAS-1 and MEV-1 to control the 6-PPDQ toxicity on longevity. Moreover, RNAi of sod-2 and sod-3, targeted genes of daf-16, caused susceptibility to 6-PPDQ toxicity in reducing lifespan and in causing reactive oxygen species (ROS) production. Therefore, 6-PPDQ at environmentally relevant concentrations (ERCs) potentially caused mitochondrial dysfunction by affecting mitochondrial complexes I and II, which was associated with lifespan reduction by affecting insulin signaling in organisms.

High expression of TBRG4 in relation to unfavorable outcome and cell ferroptosis in hepatocellular carcinoma

BackgroundHepatocellular carcinoma (HCC) is the most common type of malignant liver tumor with poor prognosis. In this study, we investigated the expression of transforming growth factor beta regulator 4 (TBRG4) in HCC and its effects on the proliferation, invasion, and metastasis of HCC cells, and analyzed the possible molecular mechanisms.MethodDownloading the expression and clinical information of HCC samples in the TCGA database, analyzing the expression differences of TBRG4 by bioinformatics methods, analyzing the clinical relevance and prognostic significance. Performing GO, KEGG and GSEA enrichment analysis on the TBRG4-related gene set in patient HCC tissues. Applying cell counting, scratch test and Transwell experiment to study the biological function of TBRG4 in HCC. Mitochondrial membrane potential, apoptosis and ROS levels were evaluated to assess cell iron death. Western blot, RT-PCR, laser confocal microscopy and co-immunoprecipitation were used to detect and analyze the downstream signaling pathways and interacting molecules of TBRG4.ResultsBioinformatics analysis revealed that TBRG4 was abnormally highly expressed in HCC tumor tissues and was associated with poor prognosis and metastasis in HCC patients. GO and KEGG functional enrichment analysis showed that TBRG4 was related to oxidative stress and NADH dehydrogenase (ubiquinone) activity. GSEA enrichment analysis showed that TBRG4 was associated with Beta catenin independent wnt signaling and B cell receptor. Functional experiments confirmed that knocking down TBRG4 could inhibit the proliferation, migration, and invasion of HCC cells. Mechanistically, TBRG4 inhibited the function of HCC cells through the DDX56/p-AKT/GSK3β signaling pathway. In addition, interference with TBRG4 expression could reduce the mitochondrial membrane potential and accumulate ROS in HCC cells, leading to increased ferroptosis. Co-IP analysis showed that TBRG4 specifically bound to Beclin1.ConclusionTBRG4 is highly expressed in HCC tumor tissues and is associated with poor prognosis. It may regulate the proliferation, invasion, and metastasis of HCC cells through the DDX56/p-AKT/GSK3β signaling pathway. TBRG4 may interact with Beclin1 to regulate the ferroptosis of HCC cells.

Early-Life Fecal Transplantation from High Muscle Yield Rainbow Trout to Low Muscle Yield Recipients Accelerates Somatic Growth through Respiratory and Mitochondrial Efficiency Modulation.

Previous studies conducted in our lab revealed microbial assemblages to vary significantly between high (ARS-FY-H) and low fillet yield (ARS-FY-L) genetic lines in adult rainbow trout. We hypothesized that a high ARS-FY-H donor microbiome can accelerate somatic growth in microbiome-depleted rainbow trout larvae of the ARS-FY-L line. Germ-depleted larvae of low ARS-FY-L line trout reared in sterile environments were exposed to high- or low-fillet yield-derived microbiomes starting at first feeding for 27 weeks. Despite weight-normalized diets, somatic mass was significantly increased in larvae receiving high fillet yield microbiome cocktails at 27 weeks post-hatch. RNA-seq from fish tails reveals enrichment in NADH dehydrogenase activity, oxygen carrier, hemoglobin complex, gas transport, and respiratory pathways in high fillet yield recolonized larvae. Transcriptome interrogation suggests a relationship between electron transport chain inputs and body weight assimilation, mediated by the gut microbiome. These findings suggest that microbiome payload originating from high fillet yield adult donors primarily accelerates juvenile somatic mass assimilation through respiratory and mitochondrial input modulation. Further microbiome studies are warranted to assess how increasing beneficial microbial taxa could be a basis for formulating appropriate pre-, pro-, or post-biotics in the form of feed additives and lead to fecal transplantation protocols for accelerated feed conversion and fillet yield in aquaculture.

MAD2L2, a key regulator in ovarian cancer and promoting tumor progression

Ovarian cancer (OVCA), a prevalent gynecological malignancy, ranks as the fourth most common cancer among women. Mitotic Arrest Deficient 2 Like 2 (MAD2L2), a chromatin-binding protein and a component of DNA polymerase ζ, has been previously identified as an inhibitor of tumor growth in colorectal cancer. However, the roles of MAD2L2 in OVCA, including its expression, impact, and prognostic significance, remain unclear. We employed bioinformatics tools, Cox Regression analysis, and in vitro cell experiments to investigate its biological functions. Our findings reveal that MAD2L2 typically undergoes genomic alterations, such as amplifications and deep deletions. Moreover, we observed an overexpression of MAD2L2 mRNA in OVCA patients, correlating with reduced survival rates, particularly in those with Grade IV tumors. Furthermore, analysis of mRNA biofunctions indicated that MAD2L2 is predominantly localized in the organellar ribosome, engaging mainly in NADH dehydrogenase activity. This was deduced from the results of gene ontology enrichment analysis, which also identified its role as a structural constituent in mitochondrial translation elongation. These findings were corroborated by KEGG pathway analysis, further revealing MAD2L2’s involvement in tumor metabolism and the cell death process. Notably, MAD2L2 protein expression showed significant associations with various immune cells, including CD4+T cells, CD8+T cells, B cells, natural killer cells, and Myeloid dendritic cells. Additionally, elevated levels of MAD2L2 were found to enhance cell proliferation and migration in OVCA cells. The upregulation of MAD2L2 also appears to inhibit the ferroptosis process, coinciding with increased mTOR signaling activity in these cells. Our study identifies MAD2L2 as a novel regulator in ovarian tumor progression and offers new insights for treating OVCA.

Unveiling Immune Infiltration Characterizing Genes in Hypertrophic Cardiomyopathy Through Transcriptomics and Bioinformatics.

Hypertrophic cardiomyopathy (HCM) is a dominantly inherited disease associated with sudden immune cell associations that remain unclear. The aim of this study was to comprehensively screen candidate markers associated with HCM and immune cells and explore potential pathogenic pathways. First, download the GSE32453 dataset to identify differentially expressed genes (DEGs) and perform Gene Ontology and pathway enrichment analysis using DAVID and GSEA. Next, construct protein-protein interaction (PPI) networks using String and Cytoscape to identify hub genes. Afterward, use CIBERSORT to determine the proportion of immune cells attributed to key genes in HCM and conduct ROC analysis based on the external dataset GSE36961 to evaluate their diagnostic value. Finally, validate the expression of key genes in the hypertrophic cardiomyocyte model through qRT-PCR using data from the HPA database. Comprehensive analysis revealed that there were 254 upregulated genes and 181 downregulated genes in HCM. The enrichment study underscored pathways of inflammatory signaling, including MAPK and PI3K-Akt pathways. Pathways abundant in genes associated with HCM encompassed myocardial contraction and NADH dehydrogenase activity. Additionally, the analysis of immune infiltration revealed a notable increase in macrophages, NK cells, and monocytes in the HCM group, showing statistically significant variances in CD4 memory resting T cell infiltration when compared to the healthy control group. Within the validation dataset GSE36961, the Area Under the Curve (AUC) scores for eight crucial genes (FOS, CD86, CD68, BDNF, PIK3R1, PLEK, RAC2, CCL2) each exceeded 0.8. The HPA database revealed the positioning traits and paths of these eight crucial genes in smooth muscle cells, myocardial cells, and fibroblasts. The outcomes of the qRT-PCR were aligned with the sequencing findings. Bioinformatics analysis unveiled pivotal genes, pathways, and immune involvement, illuminating the molecular underpinnings of HCM. These findings suggest promising therapeutic targets for clinical applications.

Effect of the overexpression of external alternative NADH dehydrogenase gene in Arabidopsis on the resistance of transformed tobacco plants to negative temperatures

The study aims to confirm the functional activity and localization of the At_NDB2 transgenic protein of Arabidopsis in tobacco cells and to evaluate the effect produced by the permanent expression of external alternative NADH dehydrogenase on the resistance of a heat-loving plant to low temperatures. Proteins and mitochondria were isolated from the leaves of tobacco plants grown at 25 °С (day/night) at the 7-leaf stage. At_NDB2 protein localization in mitochondria was determined via electrophoresis and immunoblotting. The functional activity of At_NDB2 was confirmed through the polarography of isolated mitochondria and the specific mitochondrial complex I inhibitor (rotenone). It was also found that the cyanide-resistant respiration rate and the activity of an alternative oxidase enzyme were significantly higher in transgenic plants than in wild-type plants. In order to determine the resistance to low temperatures, the parent and transgenic tobacco plants were grown in soil until the 2–3 and 6–7 leaf stages, after which they were kept at 3 to -3 °С for a day in the dark and left to regrow at 25 °С for seven days. Although it was previously shown that oxidative stress is reduced in transgenic plants at low temperatures as compared to wild-type plants, it was established that the tolerance of transgenic and nontransformed plants does not differ. Thus, alternative NADH dehydrogenase activity was found to reduce oxidative stress and increase alternative oxidase activity, without enhancing the resistance of Nicotiana tabacum to negative temperatures.

Artemisinin protects dopaminergic neurons against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced neurotoxicity in a mouse model of Parkinson’s disease

Artemisinin is an antimalarial drug that has been used for almost half a century. However, the anti-Parkinson's disease (PD) effects of artemisinin with respect to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced oxidative stress have not yet been investigated while focusing on NF-E2–related factor 2 (Nrf2) signaling. Thus, we sought to assess the behavioral and oxidative mechanistic effects of artemisinin on MPTP-induced toxicity via the Nrf2 signaling pathway. We explored this through immunohistochemical assays, ELISA, in differentiated PC12 cells treated with siRNA, and with a PD mouse model. Artemisinin increased Nrf2 DNA-binding activity and HO-1 and NQO1 expression. Artemisinin treatment protected cells against MPP+ -induced neuronal death signaling, including NADH dehydrogenase activity, reactive oxygen species, mitochondrial membrane potential, and cleaved caspase-3. Moreover, it protected cells against MPTP-induced behavioral impairments and significantly reduced dopaminergic neuronal loss. Additionally, Nrf2 pre-inhibition using ML385 neutralized the inhibitory effects of artemisinin on dopaminergic neuronal damage and behavioral impairments induced by MPTP. Our results suggest that artemisinin inhibits MPTP-induced behavioral and neurotoxic effects in mice. This provides a foundation for further research to evaluate artemisinin as a potential therapeutic agent for PD.

Mitochondrial tRNA Pseudouridylation Regulates Erythropoiesis Via the mTOR Signaling Pathway: Implications for Mlasa and Treatment Strategies

Pseudouridine, the most abundant RNA modification found in various RNA molecules, is crucial for cellular functions. Pseudouridylation is the process of converting uridine to pseudouridine, catalyzed by pseudouridine synthases (PUSs), and abnormal pseudouridylation has been linked to human diseases, including mitochondrial myopathy, lactic acidosis, and sideroblastic anemia syndrome (MLASA). MLASA is associated with genetic mutations in the PUS1 gene, leading to progressive exercise intolerance, sideroblastic anemia, hyperlactatemia, and muscle weakness. The underlying mechanism of anemia in MLASA remains unclear. In this study, we identified a novel homozygous frameshift deletion (c.523delC, p.P175fs*8) in the PUS1 gene in an MLASA patient with progressive anemia in our hospital. We investigated the role of pseudouridylation in erythropoiesis and its impact on MLASA using in vitro and in vivo approaches. We established an MLASA patient-derived inducible pluripotent stem cell (iPSC) line (referred to as MLASA-iPSCs) with the mutation, as well as a repaired line (MLASA-Res iPSC), and a corresponding mutant mouse model for the investigation. During erythroid differentiation, MLASA-iPSCs showed a significant decrease in the production of erythroblasts compared to the repaired line. Also, MLASA-iPSCs exhibited a lower ratio of mitochondrial membrane potential to mitochondrial mass, decreased oxygen consumption rates, reduced ATP production, and elevated levels of ROS. Attenuated activities of NADH dehydrogenase (Complex I) and cytochrome c reductase (Complex III) were also observed in MLASA-iPSCs, indicating compromised mitochondrial functions. Further analysis revealed a reduction in mitochondrial tRNA levels and abnormal mitochondrial translation in MLASA-iPSCs due to the specific loss of pseudouridylation. Screening of mitochondrial supplements, which could boost mitochondrial function or modulating protein synthesis, revealed that nicotinamide ribose (NR) and mitoquinone (MitoQ) improved mitochondrial function but failed to promote erythroid differentiation in MLASA-iPSCs. Interestingly, rapamycin, an mTOR inhibitor, improved erythroid differentiation in MLASA-iPSCs. Furthermore, MLASA-iPSCs showed activated mTOR signaling, increased protein synthesis and higher translation efficiency of mTOR1 targets, all of which could be rescued by rapamycin treatment, suggesting mTOR-associated translation stress. Consistently, the corresponding PUS1 mutant mouse model exhibited anemia with blocked erythropoiesis at four weeks of age. Serial competitive transplantation experiments revealed an intrinsic impairment in the reconstitution of red blood cells. Mutant erythroblasts showed impaired oxidative phosphorylation and aberrant activation of the mTOR signaling pathway. Rapamycin treatment partially alleviated the anemia phenotype in mice. Significantly, in the MLASA patient, sirolimus (rapamycin) administration under strict supervision and medical guidance effectively alleviated anemia symptoms and improved blood routine profile. In summary, our findings provide insights into the critical role of mitochondrial tRNA pseudouridylation in governing erythropoiesis via mTOR signaling pathway. We propose rapamycin as potential therapeutic strategies for anemia patients experiencing protein translation pressure, such as those with MLASA. #These authors contributed equally: Chu Y, Wang B, Shi D and Lian Y. Correspondence to: wpyuan@ihcams.ac.cn, shijun@ihcams.ac.cn Fig. 1 Schematic illustration of erythropoiesis regulated by PUS1-mediated pseudouridylation. Under physiological conditions (left), PUS1 regulates mt-tRNA abundance by catalyzing the pseudouridine synthesis of specific mt-tRNAs, thereby regulating mitochondrial translation, and ultimately affecting mitochondrial function and erythroid differentiation. In MLASA disease states (right), PUS1 deficiency causes the loss of pseudouridine modifications of specific tRNAs and thus affects the amount of PUS1 targeted tRNAs and its corresponding mitochondrial protein products, leading to mitochondrial dysfunction. The defects resulted in aberrant activation of the mTOR signaling pathway and accelerated global translation rate, ultimately leading to a blockage in erythroid differentiation, which could be relieved with rapamycin treatment.

270 Cellular Response to Heat Exposure: Influences on the Growth Potential of Bovine Skeletal Muscle and Adipose Tissue

Abstract Our lack of understanding regarding how heat exposure affects major tissue growth and meat attributes impedes our ability to counteract more frequent climate extremes and promote profitability in the beef cattle industry. The objective of the study was to determine pathways that heat shock proteins (HSPs) regulate in beef cattle’s skeletal muscle and adipose tissue growth and metabolism. Bovine satellite cells (BSCs) were isolated from the longissimus muscle of 3-month-old Holstein bulls (n = 5). Preadipose cells were isolated from the subcutaneous fat of 18-month-old Angus steers (n = 5) and induced adipogenic differentiation. Satellite, myofibers, and adipose cells were incubated at 38°C (control; CON), 39.5°C (moderate heat stress; MHS), and 41°C (extreme heat stress; EHS) and harvested for mRNA gene expressions, protein level, proteomics, immunostaining. Heat exposure cued bovine satellite cell proliferation and may increase the self-renewing satellite cell population. After 3 h of heat exposure, the mRNA gene expression and protein levels of Pax3 and Myf5 were downregulated, while HSPs 20, 27, 70, and 90 were upregulated. Small heat shock proteins, especially HSP27, appear to be essential in regulating satellite cell activity under heat stress. When HSP27 knock-down BSCs were exposed to EHS for 3 h, Myf5 gene expressions and protein levels returned to normal. This may indicate that HSP27 directly regulates Myf5 under heat stress and temporarily activates the self-renewal mechanism instead of committing myogenic differentiation. Results from proteomics showed that pathways related to oxidative phosphorylation, NADH dehydrogenase activity, and transmembrane transport were upregulated by EHS while MHS upregulated biosynthesis of amino acids, PI3K-Akt signaling pathway. Heat exposure during myogenic differentiation of satellite cells seemingly stimulates the commitment of myogenesis. Heat treatments increased mRNA gene expressions of IGF I, MHC I, MyoD, and myogenin and protein levels. Heat exposure also improved the muscle protein synthesis pathway by regulating the phosphorylation of mTOR, Akt, and P70S6. Heat stress triggered adipogenic differentiation and lipid storage, followed by increased expression of HSP. Extreme heat stress increased adipose cell growth by upregulating C/EBPα and PPARγ, key regulators of adipogenesis. Lipogenic genes FAS and SCD were also increased, accompanied by HSPs. Adipocytes exposed to EHS also increased intracellular lipid accumulation. Proteomic analysis revealed that carbon and pyruvate metabolism pathways were upregulated by MHS, whereas glycolysis/ gluconeogenesis, protein processing in the endoplasmic reticulum, RNA transport, and biosynthesis of amino acids were upregulated by EHS. Cellular mechanisms related to skeletal muscle hypertrophy and adipose tissue growth are responsive in in-vitro settings; however, the results are controversial depending on cell type and animal species. Various factors such as metabolic, hormonal, and immunologic regulation need to be considered to accurately assess the effect of HS on the postnatal growth of major tissues at the animal level.

Differential effects of OATP2B1 on statin accumulation and toxicity in a beta cell model

An increased risk of new-onset diabetes mellitus has been recently reported for statin therapy, and experimental studies have shown reduced glucose-stimulated insulin secretion (GSIS) and mitochondrial dysfunction in beta cells with effects differing among agents. Organic anion transporting polypeptide (OATP) 2B1 contributes to hepatic uptake of rosuvastatin, atorvastatin and pravastatin, three known substrates. Since OATP2B1 is present in beta cells of the human pancreas, we investigated if OATP2B1 facilitates the local accumulation of statins in a rat beta cell model INS-1 832/13 (INS-1) thereby amplifying statin-induced toxicity. OATP2B1 overexpression in INS-1 cells via adenoviral transduction showed 2.5-, 1.8- and 1.4-fold higher cellular retention of rosuvastatin, atorvastatin and pravastatin, respectively, relative to LacZ control, while absolute intracellular concentration was about twice as high for the lipophilic atorvastatin compared to the more hydrophilic rosuvastatin and pravastatin. After 24 h statin treatment at high concentrations, OATP2B1 enhanced statin toxicity involving activation of intrinsic apoptosis (caspase 3/7 activation) and mitochondrial dysfunction (NADH dehydrogenase activity) following rosuvastatin and atorvastatin, which was partly reversed by isoprenoids. OATP2B1 had no effect on statin-induced reduction in GSIS, mitochondrial electron transport chain complex expression or caspase 9 activation. We confirmed a dose-dependent reduction in insulin secretion by rosuvastatin and atorvastatin in native INS-1 with a modest change in cellular ATP. Collectively, our results indicate a role of OATP2B1, which is abundant in human beta cells, in statin accumulation and statin-induced toxicity but not insulin secretion of rosuvastatin and atorvastatin in INS-1 cells.

Biofilm metagenomic characteristics behind high coulombic efficiency for propanethiol deodorization in two-phase partitioning microbial fuel cell

Hydrophobic volatile organic sulfur compounds (VOSCs) are frequently found during sewage treatment, and their effective management is crucial for reducing malodorous complaints. Microbial fuel cells (MFC) are effective for both VOSCs abatement and energy recovery. However, the performance of MFC on VOSCs remains limited by the mass transfer efficiency of MFC in aqueous media. Inspired by two-phase partitioning biotechnology, silicone oil was introduced for the first time into MFC as a non-aqueous phase (NAP) medium to construct two-phase partitioning microbial fuel cell (TPPMFC) and augment the mass transfer of target VOSCs of propanethiol (PT) in the liquid phase. The PT removal efficiency within 32 h increased by 11–20% compared with that of single-phase MFC, and the coulombic efficiency of TPPMFC (11.01%) was 4.32–2.68 times that of single-phase MFC owing to the fact that highly active desulfurization and thiol-degrading bacteria (e.g., Pseudomonas, Achromobacter) were attached to the silicone oil surface, whereas sulfur-oxidizing bacteria (e.g., Thiobacillus, Commonas, Ottowia) were dominant on the anodic biofilm. The outer membrane cytochrome-c content and NADH dehydrogenase activity improved by 4.15 and 3.36 times in the TPPMFC, respectively. The results of metagenomics by KEGG and COG confirmed that the metabolism of PT in TPPMFC was comprehensive, and that the addition of a NAP upregulates the expression of genes related to sulfur metabolism, energy generation, and amino acid synthesis. This finding indicates that the NAP assisted bioelectrochemical systems would be promising to solve mass-transfer restrictions in low solubility contaminates removal.

Yeast NDI1 reconfigures neuronal metabolism and prevents the unfolded protein response in mitochondrial complex I deficiency.

Mutations in subunits of the mitochondrial NADH dehydrogenase cause mitochondrial complex I deficiency, a group of severe neurological diseases that can result in death in infancy. The pathogenesis of complex I deficiency remain poorly understood, and as a result there are currently no available treatments. To better understand the underlying mechanisms, we modelled complex I deficiency in Drosophila using knockdown of the mitochondrial complex I subunit ND-75 (NDUFS1) specifically in neurons. Neuronal complex I deficiency causes locomotor defects, seizures and reduced lifespan. At the cellular level, complex I deficiency does not affect ATP levels but leads to mitochondrial morphology defects, reduced endoplasmic reticulum-mitochondria contacts and activation of the endoplasmic reticulum unfolded protein response (UPR) in neurons. Multi-omic analysis shows that complex I deficiency dramatically perturbs mitochondrial metabolism in the brain. We find that expression of the yeast non-proton translocating NADH dehydrogenase NDI1, which reinstates mitochondrial NADH oxidation but not ATP production, restores levels of several key metabolites in the brain in complex I deficiency. Remarkably, NDI1 expression also reinstates endoplasmic reticulum-mitochondria contacts, prevents UPR activation and rescues the behavioural and lifespan phenotypes caused by complex I deficiency. Together, these data show that metabolic disruption due to loss of neuronal NADH dehydrogenase activity cause UPR activation and drive pathogenesis in complex I deficiency.

A Multifunctional Nanozyme with NADH Dehydrogenase-like Activity and Nitric Oxide Release Under Near Infrared Light Irradiation as an Efficient Therapeutic for Antimicrobial Resistance Infection and Wound Healing.

In recent years, antimicrobial resistance (AMR) has become one of the greatest threats to human health. There is an urgent need to develop new antibacterial agents to effectively treat AMR infection. Herein, a novel nanozyme platform {Cu, N-GQDs@Ru-NO} was prepared, where Cu, N-doped graphene quantum dots (Cu, N-GQDs) were covalently functionalized with a nitric oxide (NO) donor, ruthenium nitrosyl (Ru-NO). Under 808nm near infrared (NIR) light irradiation, {Cu, N-GQDs@Ru-NO} demonstrated nicotinamide adenine dinucleotide (NADH) dehydrogenase-like activity for photo-oxidizing NADH to NAD+ , thus disrupting the redox balance in bacterial cells and resulting in bacterial death; meanwhile, the onsite NIR light-delivered NO effectively eradicated the methicillin-resistant staphylococcus aureus (MRSA) bacterial and biofilms, and promoted wound healing; furthermore, the nanozyme showed excellent photothermal effect that enhanced the antibacterial efficacy as well. With the combination of NADH dehydrogenase activity, photothermal therapy, and NO gas therapy, the Cu, N-GQDs@Ru-NO nanozyme displayed both in vitro and in vivo excellent efficacy for MRSA infection and biofilm eradication, which provides a new therapeutic modality for effectively treating MRSA inflammatory wounds. This article is protected by copyright. All rights reserved.

An Exploration of the Coherent Effects between METTL3 and NDUFA10 on Alzheimer's Disease.

Alzheimer's disease (AD) is a neurodegenerative disorder characterized primarily by a decline in cognitive function. However, the etiopathogenesis of AD is unclear. N6-methyladenosine (m6A) is abundant in the brain, and it is interesting to explore the relationship between m6A and AD causes. In this paper, the gene expression of METTL3 and NDUFA10 were found to correlate with the Mini-mental State Examination (MMSE), which is a clinical indicator of the degree of dementia. METTL3 is involved in post-transcriptional methylation and the formation of m6A. NDUFA10 encodes the protein with NADH dehydrogenase activity and oxidoreductase activity in the mitochondrial electron transport chain. The following three characteristics were observed in this paper: 1. The lower the expression level of NDUFA10, the smaller the MMSE, and the higher the degree of dementia. 2. If the expression level of METTL3 dropped below its threshold, the patient would have a risk of AD with a probability close to 100%, suggesting a basic necessity for m6A to protect mRNA. 3. The lower the expression levels of both METTL3 and NDUFA10, the more likely the patient would suffer from AD, implying the coherence between METTL3 and NDUFA10. Regarding the above discovery, the following hypothesis is presented: METTL3 expression level is downregulated, then the m6A modification level of NDUFA10 mRNA is also decreased, thereby reducing the expression level of NDUFA10-encoded protein. Furthermore, the abnormal expression of NDUFA10 contributes to the assembly disorder of mitochondrial complex I and affects the process of the electron respiratory chain, with the consequent development of AD. In addition, to confirm the above conclusions, the AI Ant Colony Algorithm was improved to be more suitable for discovering the characteristics of AD data, and the SVM diagnostic model was applied to mine the coherent effects on AD between METTL3 and NDUFA10. In conclusion, our findings suggest that dysregulated m6A leads to altered expression of its target genes, thereby affecting AD's development.

Alleviative effects of pinostrobin against cadmium-induced renal toxicity in rats by reducing oxidative stress, apoptosis, inflammation, and mitochondrial dysfunction.

Cadmium (Cd) is a highly toxic heavy metal that can be found everywhere in the environment and can have harmful effects on both human and animal health. Pinostrobin (PSB) is a bioactive natural flavonoid isolated from Boesenbergia rotunda with several pharmacological properties, such as antiinflammatory, anticancer, antioxidant, and antiviral. This investigation was intended to assess the therapeutic potential of PSB against Cd-induced kidney damage in rats. In total, 48 Sprague Dawley rats were divided into four groups: a control, a Cd (5 mg/kg), a Cd + PSB group (5 mg/kg Cd and 10 mg/kg PSB), and a PSB group (10 mg/kg) that received supplementation for 30 days. Exposure to Cd led to a decrease in the activities of catalase (CAT), glutathione reductase (GSR), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX), whereas levels of reactive oxygen species (ROS) and malondialdehyde (MDA) increased. Cd exposure also caused a substantial increase in urea, kidney injury molecule-1 (KIM-1), neutrophil gelatinase-associated lipocalin (NGAL), and creatinine levels. Moreover, a noticeable decline was noticed in creatinine clearance. Moreover, Cd exposure considerably increased the levels of inflammatory indices, including interleukin-1b (IL-1b), tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), nuclear factor kappa-B (NF-kB), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) activity. Cd treatment decreased the expression of the antiapoptotic markers (Bcl-2) while increasing the expression of apoptotic markers (Bax and Caspase-3). Furthermore, Cd treatment substantially reduced the TCA cycle enzyme activity, such as alpha-ketoglutarate dehydrogenase, succinate dehydrogenase, malate dehydrogenase, and isocitrate dehydrogenase. Moreover, mitochondrial electron transport chain enzymes, succinatedehydrogenase, NADH dehydrogenase, cytochrome c-oxidase, and coenzyme Q-cytochrome reductase activities were also decreased following Cd exposure. PSB administration substantially reduced the mitochondrial membrane potential while inducing significant histological damage. However, PSB treatment significantly reduced Cd-mediated renal damage in rats. Thus, the present investigation discovered that PSB has ameliorative potential against Cd-induced renal dysfunction in rats.

Involvement of a flavoprotein, acetohydroxyacid synthase, in growth and riboflavin production in riboflavin-overproducing Ashbya gossypii mutant

BackgroundPreviously, we isolated a riboflavin-overproducing Ashbya gossypii mutant (MT strain) and discovered some mutations in genes encoding flavoproteins. Here, we analyzed the riboflavin production in the MT strain, in view of flavoproteins, which are localized in the mitochondria.ResultsIn the MT strain, mitochondrial membrane potential was decreased compared with that in the wild type (WT) strain, resulting in increased reactive oxygen species. Additionally, diphenyleneiodonium (DPI), a universal flavoprotein inhibitor, inhibited riboflavin production in the WT and MT strains at 50 µM, indicating that some flavoproteins may be involved in riboflavin production. The specific activities of NADH and succinate dehydrogenases were significantly reduced in the MT strain, but those of glutathione reductase and acetohydroxyacid synthase were increased by 4.9- and 25-fold, respectively. By contrast, the expression of AgGLR1 gene encoding glutathione reductase was increased by 32-fold in the MT strain. However, that of AgILV2 gene encoding the catalytic subunit of acetohydroxyacid synthase was increased by only 2.1-fold. These results suggest that in the MT strain, acetohydroxyacid synthase, which catalyzes the first reaction of branched-chain amino acid biosynthesis, is vital for riboflavin production. The addition of valine, which is a feedback inhibitor of acetohydroxyacid synthase, to a minimal medium inhibited the growth of the MT strain and its riboflavin production. In addition, the addition of branched-chain amino acids enhanced the growth and riboflavin production in the MT strain.ConclusionThe significance of branched-chain amino acids for riboflavin production in A. gossypii is reported and this study opens a novel approach for the effective production of riboflavin in A. gossypii.

The Effects of Manual Acupuncture on Mitochondrial Fusion and Fission Gene Expression in Rat Spleen

A significant amount of research has been conducted to establish the validity of acupuncture, and it has been demonstrated through animal disease model studies that acupuncture influences mitochondrial changes. However, to more accurately examine the mechanisms of acupuncture treatment effectiveness in pathological models, it is crucial to investigate changes in disease-free animals. Among various hypotheses regarding the effects of acupuncture on the body, we focused on the result that acupuncture stimulation is related to mitochondria. We examined the effects of acupuncture mitochondrial fission and fusionrelated mediators in disease-free Sprague Dawley (SD) rats' spleen meridian acupoints. SD rats were divided into control, SP1, SP2, SP3, SP5, and SP9 acupuncture groups. Acupuncture was performed at each point for 10 minutes daily for four days. Peroxisome proliferator-activated receptor-gamma coactivator 1-α (PGC-1α) and fission protein 1 (Fis1) levels were evaluated using quantitative real-time polymerase chain reaction (qRT-PCR), while dynamin-related protein 1 (DRP1), optic atrophy-1 (OPA1), mitofusin-1 (MFN1), and mitofusin-2 (MFN2) levels were assessed via western blotting. Mitochondria protein concentrations and NADH dehydrogenase activity in spleen tissues were measured using enzyme-linked immunosorbent assay (ELISA). PGC-1α expression decreased in the SP1 (p < 0.01), SP5 (p < 0.05), and SP9 (p < 0.05) groups, while Fis1 expression increased in the SP1 (p < 0.01), SP5 (p < 0.01), and SP9 (p < 0.05) groups. DRP1, OPA1, MFN1, and MFN2 levels exhibited no significant changes. Mitochondrial protein concentrations decreased in the SP2 (p < 0.01), SP3 (p < 0.01), SP5 (p < 0.01), and SP9 (p < 0.01) groups, while NADH dehydrogenase activity decreased in the SP2 (p < 0.05) and SP9 (p < 0.05) groups. Acupuncture at the SP9 acupoint influenced the mitochondrial fission pathway by modulating PGC-1α and Fis1 mediators in the rat spleen under non-disease conditions.