Currently, the incidence of Parkinson's disease (PD) is on the rise. More and more evidences suggest that mitochondrial dysfunction plays a crucial role in the etiology of PD, and dysfunction of mitochondrial complex I (MCI) is one of the most critical factors leading to mitochondrial dysfunction. On one hand, MCI dysfunction stimulates dopaminergic neurons to produce reactive oxygen species (ROS). On the other hand, MCI dysfunction decreases dopaminergic neuron viability and reduces ATP production. All these outcomes promote the pathological progression of PD. This review summarizes research progress on the role of MCI in the pathogenesis of PD, as well as PD treatment strategies based on MCI.
Parkinson Disease/metabolism* ; Humans ; Electron Transport Complex I/metabolism* ; Mitochondria/physiology* ; Reactive Oxygen Species/metabolism* ; Dopaminergic Neurons/metabolism* ; Animals ; Adenosine Triphosphate/metabolism*

This study explores the effect of total secondary ginsenosides(TSG) on apoptosis and energy metabolism in H9c2 cells under hypoxia and its potential mechanisms. H9c2 cell viability was observed and the apoptosis rate was calculated to determine suitable intervention concentrations of TSG, antimycin A complex(AMA), and coenzyme Q10(CoQ10), along with the duration of hypoxia. H9c2 cells at the logarithmic phase were divided into a normal group, a model group, a TSG group, an AMA group, a TSG+AMA group, and a CoQ10 group. All groups, except the normal group, were treated with their respective intervention drugs and cultured under hypoxic conditions. Adenosine triphosphate(ATP) content and creatine kinase(CK) activity were measured using an ATP chemiluminescence assay kit and a CK colorimetric assay kit. Flow cytometry was used to assess apoptosis rates, and Western blot evaluated the expression levels of apoptosis-related proteins, including B-cell lymphoma 2(Bcl-2), Bcl-2-associated X protein(Bax), cysteinyl aspartate-specific protease(caspase)-3, caspase-8, and caspase-9, as well as mitochondrial biogenesis-related proteins peroxisome proliferator-activated receptor-γ coactivator 1α(PGC-1α), estrogen-related receptor-α(ERRα), nuclear respiratory factor(NRF)-1, NRF-2, peroxisome proliferator activated receptor-α(PPARα), and Na~+-K~+-ATPase. RT-PCR was employed to analyze the mRNA expression of mitochondrial biogenesis factors, including PGC-1α, ERRα, NRF-1, NRF-2, PPARα, mitochondrial transcription factor A(TFAM), mitochondrial cytochrome C oxidase 1(COX1), and mitochondrial NADH dehydrogenase subunit 1(ND1), ND2. The selected intervention concentrations were 7.5 μg·mL~(-1) for TSG, 10 μmol·L~(-1) for AMA, and 1×10~(-4) mol·L~(-1) for CoQ10, with a hypoxia duration of 6 h. Compared with the normal group, the model group showed decreased ATP content and CK activity, increased apoptosis rates, decreased Bcl-2 expression, and increased Bax, caspase-3, caspase-8, and caspase-9 expression in H9c2 cells. Additionally, the protein and mRNA expression levels of mitochondrial biogenesis-related factors(PGC-1α, ERRα, NRF-1, NRF-2, PPARα), mRNA expression of TFAM, COX1, and ND1, ND2, and protein expression of Na~+-K~+-ATPase in mitochondrial DNA, were also reduced. In the TSG and CoQ10 groups, ATP content and CK activity increased, and apoptosis rates decreased compared with those in the model group. The TSG group showed decreased protein expression of apoptosis-related proteins Bax, caspase-3, caspase-8, and caspase-9, increased protein and mRNA expression of mitochondrial biogenesis factors PGC-1α, ERRα, NRF-1, and PPARα, and increased NRF-2 protein expression and TFAM mRNA expression in mitochondrial DNA. Conversely, in the AMA group, ATP content and CK activity decreased, the apoptosis rate increased, Bcl-2 expression decreased, and Bax, caspase-3, caspase-8, and caspase-9 expression increased, alongside reductions in PGC-1α, ERRα, NRF-1, NRF-2, PPARα protein and mRNA expression, as well as TFAM, COX1, ND1, ND2 mRNA expression and Na~+-K~+-ATPase protein expression. Compared with the TSG group, the TSG+AMA group exhibited decreased ATP content and CK activity, increased apoptosis rates, decreased Bcl-2 expression, and increased Bax, caspase-3, caspase-8, and caspase-9 expression, along with decreased PGC-1α, ERRα, NRF-1, NRF-2, and PPARα protein and mRNA expression and TFAM, COX1, and ND1, ND2 mRNA expression. Compared with the AMA group, the TSG+AMA group showed increased CK activity, decreased apoptosis rate, increased Bcl-2 expression, and decreased Bax, caspase-8, and caspase-9 expression. Additionally, the protein and mRNA expression of PGC-1α, ERRα, NRF-1, PPARα, mRNA expression of TFAM, COX1, ND1, ND2, and Na~+-K~+-ATPase protein expression increased. In conclusion, TSG enhance ATP content and CK activity and inhibit apoptosis in H9c2 cells under hypoxia, and the mechanisms may be related to the regulation of PGC-1α, ERRα, NRF-1, NRF-2, PPARα, and TFAM expression, thus promoting mitochondrial biogenesis.
Apoptosis/drug effects* ; Ginsenosides/pharmacology* ; Energy Metabolism/drug effects* ; Mitochondria/metabolism* ; Animals ; Rats ; Cell Line ; Cell Hypoxia/drug effects* ; Organelle Biogenesis ; Adenosine Triphosphate/metabolism* ; Humans ; Cell Survival/drug effects*

This article aims to explore the effect and mechanism of Liujunzi Pills on the intestinal microbiota of rats with spleen Qi deficiency syndrome. The raw Rhei Radix et Rhizoma water extract(1 g·mL~(-1)) was used to prepare spleen Qi deficiency rat models. A total of 44 SD male rats were randomly divided into a control group, a model group, Liujunzi Pills groups at high(3.24 g·kg~(-1)), medium(1.62 g·kg~(-1)), low(0.81 g·kg~(-1)) doses, and Shenling Baizhu San(2.50 g·kg~(-1)) group. The drug effect was evaluated by observing the following aspects: spleen index, fecal water content, body weight, and intestinal propulsion index. Gut microbiota analysis and 16S rRNA gene sequencing were conducted on feces. Enzyme-linked immunosorbent assay(ELISA) and UV spectrophotometry were used to detect interleukin-1β(IL-1β) and adenosine triphosphate(ATP) levels in small intestine tissues. Hematoxylin-eosin staining and transmission electron microscopy were employed to observe changes in intestinal pathology and microstructure. The results show that, compared with the control group, fecal moisture content is significantly increased while spleen index, body weight, and intestinal propulsion index are significantly reduced in rats of the model group, indicating the successful establishment of the model. The above symptoms can be improved by both Shenling Baizhu San and Liujunzi Pills. Compared with the control group, in the model group, the gut microbiota abundance is changed with an unbalanced development: the abundance of beneficial bacteria within the Bacteroidetes phylum is reduced, accompanied by a significantly decreased Shannon index, and reduced signal levels of nicotinamide adenine dinucleotide phosphate(NADPH)-related enzymes relevant to mitochondria. However, Liujunzi Pills and Shenling Baizhu San can significantly improve the Bacteroidetes phylum abundance in gut microbiota, microbial diversity, and NADPH activity in the model group. Additionally, compared with the control group, the ATP level is decreased and the IL-1β level is increased in small intestinal tissues of the model group, with shorter small intestinal epithelial villi and decreased mitochondrial number. The above symptoms can be improved by Liujunzi Pills and Shenling Baizhu San. In conclusion, Liujunzi Pills can treat spleen Qi deficiency syndrome by enhancing mitochondrial function to regulate gut microbiota balance and diversity.
Animals ; Gastrointestinal Microbiome/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Male ; Rats, Sprague-Dawley ; Rats ; Qi ; Spleen/metabolism* ; Splenic Diseases/metabolism* ; Humans ; Interleukin-1beta/genetics* ; Bacteria/drug effects* ; Feces/microbiology* ; Adenosine Triphosphate/metabolism*

Triclocarban (TCC) is a broad-spectrum antimicrobial widely used in various personal care products, textiles, and children's toys. TCC has potential reproductive and developmental toxicity in animals. However, little is known regarding the effect of TCC on human sperm function. In this study, an in vitro assay was used to investigate the effects of TCC on normal human spermatozoa and the possible underlying mechanisms involved. Semen from healthy male donors was collected and cultured in complete Biggers, Whitten and Whittingham (BWW) and low-sugar BWW media, followed by treatment with TCC at concentrations of 0, 0.1 µmol l -1 , 1 µmol l -1 , 10 µmol l -1 , and 100 µmol l -1 for 4 h. TCC was found to reduce the sperm total motility and progressive motility. Moreover, the sperm kinematic parameters, straight-line velocity (VSL), average path velocity (VAP), and curvilinear velocity (VCL) were affected in a dose-dependent manner. After treatment with TCC at the lowest effective concentration of 10 µmol l -1 , TCC caused a significant decrease in mitochondrial adenosine triphosphate (ATP) production and mitochondrial membrane potential (MMP) and a significant increase in reactive oxygen species (ROS), similar to the observations with the positive control carbonyl cyanide 4-(trifluoromethoxy) phenylhydrazone (FCCP), suggesting that TCC may decrease sperm motility by affecting the oxidative phosphorylation (OXPHOS) pathway. In a sugar-free and low-sugar BWW culture environment, TCC enhanced the damaging effect on sperm motility and ATP, MMP, and lactate decreased significantly, suggesting that TCC may also affect the glycolytic pathway that supplies energy to spermatozoa. This study demonstrates a possible mechanism of TCC toxicity in spermatozoa involving both the OXPHOS and glycolysis pathways.
Male ; Sperm Motility/drug effects* ; Humans ; Carbanilides/pharmacology* ; Oxidative Phosphorylation/drug effects* ; Glycolysis/drug effects* ; Membrane Potential, Mitochondrial/drug effects* ; Adenosine Triphosphate/metabolism* ; Spermatozoa/metabolism* ; Reactive Oxygen Species/metabolism* ; Mitochondria/metabolism*

Periodontitis is a common oral disease caused by bacteria coupled with an excessive host immune response. Stem cell therapy can be a promising treatment strategy for periodontitis, but the relevant mechanism is complicated. This study aimed to explore the therapeutic potential of mitochondria from human embryonic stem cell-derived mesenchymal stem cells (hESC-MSCs) for the treatment of periodontitis. The gingival tissues of periodontitis patients are characterized by abnormal mitochondrial structure. Human gingival fibroblasts (HGFs) were exposed to 5 μg/mL lipopolysaccharide (LPS) for 24 h to establish a cell injury model. When treated with hESC-MSCs or mitochondria derived from hESC-MSCs, HGFs showed reduced expression of inflammatory genes, increased adenosine triphosphate (ATP) level, decreased reactive oxygen species (ROS) production, and enhanced mitochondrial function compared to the control. The average efficiency of isolated mitochondrial transfer by hESC-MSCs was determined to be 8.93%. Besides, a therapy of local mitochondrial injection in mice with LPS-induced periodontitis showed a reduction in inflammatory gene expression, as well as an increase in both the mitochondrial number and the aspect ratio in gingival tissues. In conclusion, our results indicate that mitochondria derived from hESC-MSCs can reduce the inflammatory response and improve mitochondrial function in HGFs, suggesting that the transfer of mitochondria between hESC-MSCs and HGFs serves as a potential mechanism underlying the therapeutic effect of stem cells.
Humans ; Gingiva/cytology* ; Fibroblasts/metabolism* ; Mitochondria/physiology* ; Mesenchymal Stem Cells/cytology* ; Animals ; Periodontitis/therapy* ; Mice ; Reactive Oxygen Species/metabolism* ; Inflammation ; Lipopolysaccharides ; Human Embryonic Stem Cells/cytology* ; Cells, Cultured ; Adenosine Triphosphate/metabolism* ; Male

Energy metabolism regulation plays a pivotal role in metabolic engineering. It mainly achieves the balance of material and energy metabolism or maximizes the utilization of materials and energy by regulating the supply intensity and mode of ATP and reducing electron carriers in cells. On the one hand, the production efficiency can be increased by changing the distribution of material metabolic flow. On the other hand, the thermodynamic parameters of enzyme-catalyzed reactions can be altered to affect the reaction balance, and thus the production costs are reduced. Therefore, energy metabolism regulation is expected to become a favorable tool for the modification of microbial cell factories, thereby increasing the production of target metabolites and reducing production costs. This article introduces the commonly used energy metabolism regulation methods and their effects on cell factories, aiming to provide a reference for the efficient construction of microbial cell factories.
Energy Metabolism/physiology* ; Metabolic Engineering/methods* ; Adenosine Triphosphate/metabolism* ; Industrial Microbiology/methods*

Succinic acid is an important C4 platform chemical that is widely used in food, chemical, medicine sectors. The bottleneck of fermentative production of succinic acid by engineered Escherichia coli is the imbalance of intracellular cofactors, which often leads to accumulation of by-products, lower yield and low productivity. Stoichiometric analysis indicated that an efficient production of succinic acid by E. coli FMME-N-26 under micro-aeration conditions might be achieved when the TCA cycle provides enough ATP and NADH for the r-TCA pathway. In order to promote succinic acid production, a serial of metabolic engineering strategies include reducing ATP consumption, strengthening ATP synthesis, blocking NADH competitive pathway and constructing NADH complementary pathway were developed. As result, an engineered E. coli FW-17 capable of producing 139.52 g/L succinic acid and 1.40 g/L acetic acid in 5 L fermenter, which were 17.81% higher and 67.59% lower than that of the control strain, was developed. Further scale-up experiments were carried out in a 1 000 L fermenter, and the titer of succinic acid and acetic acid were 140.2 g/L and 1.38 g/L, respectively.
Escherichia coli/genetics* ; NAD ; Succinic Acid ; Acetic Acid ; Adenosine Triphosphate

ATP is an important cofactor involved in many biocatalytic reactions that require energy input. Polyphosphate kinases (PPK) can provide energy for ATP-consuming reactions due to their cheap and readily available substrate polyphosphate. We selected ChPPK from Cytophaga hutchinsonii for substrate profiling and tolerance analysis. By molecular docking and site-directed mutagenesis, we rationally engineered the dual-substrate channel cavity of polyphosphate kinase to improve the catalytic activity of PPK. Compared with the wild type, the relative enzyme activity of the screened mutant ChPPK_K81H-K103V increased by 326.7%. Meanwhile, the double mutation expanded the substrate utilization range and tolerance of ChPPK, and improved its heat and alkali resistance. Subsequently, we coupled the glutathione bifunctional enzyme GshAB and ChPPK_K81H-K103V based on this ATP regeneration system, and glutathione was produced by cell-free catalysis upon disruption of cells. This system produced (25.4±1.9) mmol/L glutathione in 6 h upon addition of 5 mmol/L ATP. Compared with the system before mutation, glutathione production was increased by 41.9%. After optimizing the buffer, bacterial mass and feeding time of this system, (45.2±1.8) mmol/L glutathione was produced in 6 h and the conversion rate of the substrate l-cysteine was 90.4%. Increasing the ability of ChPPK enzyme to produce ATP can effectively enhance the conversion rate of substrate and reduce the catalytic cost, achieving high yield, high conversion rate and high economic value for glutathione production by cell-free catalysis. This study provides a green and efficient ATP regeneration system that may further power the ATP-consuming biocatalytic reaction platform.
Molecular Docking Simulation ; Catalysis ; Glutathione ; Adenosine Triphosphate

Yeast autolysis affects the flavor and quality of beer. The regulation of yeast autolysis is a need for industrial beer production. Previous studies on brewer's yeast autolysis showed that the citric acid cycle-related genes had a great influence on yeast autolysis. To explore the contribution of isocitrate dehydrogenase genes in autolysis, the IDP1 and IDP2 genes were destroyed or overexpressed in typical lager yeast Pilsner. The destruction of IDP1 gene improved the anti-autolytic ability of yeast, and the anti-autolytic index after 96 h autolysis was 8.40, 1.5 times higher than that of the original strain. The destruction of IDP1 gene increased the supply of nicotinamide adenine dinucleotide phosphate (NADPH) and the NADPH/NADP⁺ ratio was 1.94. After fermentation, intracellular ATP level was 1.8 times higher than that of the original strain, while reactive oxygen species (ROS) was reduced by 10%. The destruction of IDP2 gene resulted in rapid autolysis and a decrease in the supply of NADPH. Anti-autolytic index after 96 h autolysis was 4.03 and the NADPH/NADP⁺ ratio was 0.89. After fermentation, intracellular ATP level was reduced by 8% compared with original strain, ROS was 1.3 times higher than that of the original strain. The results may help understand the regulation mechanism of citric acid cycle-related genes on yeast autolysis and provide a basis for the selection of excellent yeast with controllable anti-autolytic performance.
Humans ; Isocitrate Dehydrogenase/genetics* ; NADP ; Reactive Oxygen Species ; Autolysis ; Adenosine Triphosphate

Reducing lactate accumulation has always been a goal of the mammalian cell biotechnology industry. When animal cells are cultured in vitro, the accumulation of lactate is mainly the combined result of two metabolic pathways. On one hand, glucose generates lactate under the function of lactate dehydrogenase A (LDHA); on the other hand, lactate can be oxidized to pyruvate by LDHB or LDHC and re-enter the TCA cycle. This study comprehensively evaluated the effects of LDH manipulation on the growth, metabolism and human adenovirus (HAdV) production of human embryonic kidney 293 (HEK-293) cells, providing a theoretical basis for engineering the lactate metabolism in mammalian cells. By knocking out ldha gene and overexpression of ldhb and ldhc genes, the metabolic efficiency of HEK-293 cells was effectively improved, and HAdV production was significantly increased. Compared with the control cell, LDH manipulation promoted cell growth, reduced the accumulation of lactate and ammonia, significantly enhanced the efficiency of substrate and energy metabolism of cells, and significantly increased the HAdV production capacity of HEK-293 cells. Among these LDH manipulation measures, ldhc gene overexpression performed the best, with the maximum cell density increased by about 38.7%. The yield of lactate to glucose and ammonia to glutamine decreased by 33.8% and 63.3%, respectively; and HAdV titer increased by at least 16 times. In addition, the ATP production rate, ATP/O₂ ratio, ATP/ADP ratio and NADH content of the modified cell lines were increased to varying degrees, and the energy metabolic efficiency was significantly improved.
Animals ; Humans ; L-Lactate Dehydrogenase/genetics* ; Lactic Acid ; Adenoviruses, Human ; Ammonia ; HEK293 Cells ; Glucose/metabolism* ; Adenosine Triphosphate/metabolism* ; Kidney/metabolism* ; Mammals/metabolism*