OBJECTIVE: To explore the role of reactive oxygen species (ROS) and lactate dehydrogenase isoenzyme X (LDH-X) in the changes of sperm mitochondrial membrane potential (MMP) in infertility patients with varicocele (VC). METHODS: This study included 38 infertility patients with VC (VCinf), 35 non-VC infertile males (NVCinf), and 30 normal fertile men as controls. We obtained the routine semen parameters using the sperm quality analysis system, examined the contents of LDH-X in the seminal plasma and sperm with the automatic biochemical analyzer, measured the level of malondialdehyde (MDA) in seminal plasma by thiobarbituric acid (TBA) colorimetry, and determined the expressions of mitochondrial membrane potential (MMP) and LDH-X mRNA in the sperm using JC-1 fluorescence probe and RT-PCR. RESULTS: No statistically significant differences were observed among the three groups of subjects in age, semen pH value, semen volume and sperm concentration (P > 0.05). Compared with the normal fertile controls, the patients in the VCinf and NVCinf groups showed significantly decreased sperm motility (［52.36 ± 12.48］% vs ［34.74 ± 15.23］% vs ［25.76 ± 13.73］%, P< 0.05), percentage of progressively motile sperm (PMS) (［42.54 ± 13.58］% vs ［29.10 ± 14.17］% vs ［20.95 ± 12.33］%, P< 0.05), sperm LDH-X (［16.46 ± 5.47］ vs ［13.63 ± 4.50］ vs ［10.18 ± 3.00］ mU/106, P< 0.05), sperm MMP (［48.04 ± 11.62］% vs ［40.86 ± 12.69］% vs ［34.41 ± 13.93］%, P< 0.05) and expression of sperm LDH-X mRNA (P< 0.05). but increased seminal plasma LDH-X (［935.36 ± 229.48］ vs ［1241.05 ± 337.07］ vs ［1425.08 ± 469.35］ U/L, P< 0.05), seminal plasma/whole sperm LDH-X (［1.06 ± 0.35］ vs ［1.40 ± 0.34］ vs ［1.63 ± 0.66］, P< 0.05), and content of seminal plasma MDA (［1.10 ± 0.19］ vs ［1.59 ± 0.27］ vs ［2.00 ± 0.22］ nmol/ml, P< 0.05). CONCLUSION Excessive ROS in the reproductive system of VCinf patients reduces the content of MMP and causes the overflow of LDH-X out of sperm cells. Therefore the decrease of sperm LDH-X may be accompanied by that of MMP.
Humans ; Male ; Infertility, Male/etiology* ; Varicocele/metabolism* ; Adult ; Reactive Oxygen Species/metabolism* ; Spermatozoa/metabolism* ; L-Lactate Dehydrogenase/metabolism* ; Membrane Potential, Mitochondrial ; Isoenzymes/metabolism* ; Case-Control Studies ; Young Adult ; Mitochondrial Membranes/metabolism*

Mitochondria-associated endoplasmic reticulum membranes (MAMs) are the physical connection sites between mitochondria and endoplasmic reticulum (ER). As the compartments controlling substance and information communications between ER and mitochondria, MAMs were involved in the regulation of various pathophysiological processes, such as calcium homeostasis, mitochondrial morphology and function, lipid metabolism and autophagy. In the past decades, accumulating lines of evidence have revealed the pivotal role of MAMs in diverse cardiovascular diseases (CVD). Aging is one of the major independent risk factors for CVD, which causes progressive degeneration of the cardiovascular system, leading to increased morbidity and mortality of CVD. This review aims to summarize the research progress of MAMs in age-related CVD, and explore new targets for its prevention and treatment.
Humans ; Mitochondrial Membranes ; Cardiovascular Diseases/metabolism* ; Calcium Signaling/physiology* ; Mitochondria/physiology* ; Endoplasmic Reticulum/metabolism*

Objective To study the effect and mechanism of blueberry on regulating the mitochondrial inner membrane protein mitofilin/Mic60 in an in vitro model of metabolic dysfunction-associated liver disease (MAFLD). Methods L02 human hepatocytes were induced by free fatty acids (FFA) to establish MAFLD cell model. A normal group, a model group, an 80 μg/mL blueberry treatment group, a Mic60 short hairpin RNA (Mic60 shRNA) transfection group, and Mic60 knockdown combined with an 80 μg/mL blueberry treatment group were established. The intracellular lipid deposition was observed by oil red O staining, and the effect of different concentrations of blueberry pulp on the survival rate of L02 cells treated with FFA was measured by MTT assay. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), triglyceride (TG), total cholesterol (TC), superoxide dismutase (SOD) activity, glutathione (GSH) and malondialdehyde (MDA) contents were measured by visible spectrophotometry. The expression of reactive oxygen species (ROS) in hepatocytes was observed by fluorescence microscopy, and the mRNA and protein expression of Mic60 were detected by real-time quantitative PCR and Western blot analysis, respectively. Results After 24 hours of FFA stimulation, a large number of red lipid droplets in the cytoplasm of L02 cells was observed, and the survival rate of L02 cells treated with 80 μg/mL blueberry was higher. The results of ALT, AST, TG, TC, MDA and the fluorescence intensity of ROS in blueberry treated group were lower than those in model group, while the levels of SOD, GSH, Mic60 mRNA and protein in blueberry treated group were higher than those in model group. Conclusion Blueberry promotes the expression of Mic60, increases the levels of SOD and GSH in hepatocytes, and reduces the production of ROS, thus alleviating the injury of MAFLD hepatocytes and regulating the disorder of lipid metabolism.
Humans ; Blueberry Plants/chemistry* ; Hepatocytes/metabolism* ; Liver/metabolism* ; Liver Diseases/metabolism* ; Reactive Oxygen Species/metabolism* ; Superoxide Dismutase/metabolism* ; Superoxides/metabolism* ; Mitochondrial Membranes/metabolism* ; Mitochondrial Proteins/metabolism* ; Plant Extracts/pharmacology*

Mitochondrial injury and endoplasmic reticulum (ER) stress are considered to be the key mechanisms of renal ischemia-reperfusion (I/R) injury. Mitochondria are membrane-bound organelles that form close physical contact with a specific domain of the ER, known as mitochondrial-associated membranes. The close physical contact between them is mainly restrained by ER-mitochondria tethering complexes, which can play an important role in mitochondrial damage, ER stress, lipid homeostasis, and cell death. Several ER-mitochondria tethering complex components are involved in the process of renal I/R injury. A better understanding of the physical and functional interaction between ER and mitochondria is helpful to further clarify the mechanism of renal I/R injury and provide potential therapeutic targets. In this review, we aim to describe the structure of the tethering complex and elucidate its pivotal role in renal I/R injury by summarizing its role in many important mechanisms, such as mitophagy, mitochondrial fission, mitochondrial fusion, apoptosis and necrosis, ER stress, mitochondrial substance transport, and lipid metabolism.
Endoplasmic Reticulum/metabolism* ; Endoplasmic Reticulum Stress ; Humans ; Mitochondria ; Mitochondrial Membranes/metabolism* ; Mitophagy ; Reperfusion Injury/metabolism*

The aim of the present study was to investigate the role of ferroptosis in acute lung injury (ALI) mouse model induced by oleic acid (OA). ALI was induced in the mice via the lateral tail vein injection of pure OA. The histopathological score of lung, lung wet-dry weight ratio and the protein content of bronchoalveolar lavage fluid (BALF) were used as the evaluation indexes of ALI. Iron concentration, glutathione (GSH) and malondialdehyde (MDA) contents in the lung tissues were measured using corresponding assay kits. The ultrastructure of pulmonary cells was observed by transmission electron microscope (TEM), and the expression level of prostaglandin-endoperoxide synthase 2 (PTGS2) mRNA was detected by quantitative polymerase chain reaction (q-PCR). Protein expression levels of glutathione peroxidase 4 (GPX4), ferritin and transferrin receptor 1 (TfR1) in lung tissues were determined by Western blot. The results showed that histopathological scores of lung tissues, lung wet-dry weight ratio and protein in BALF in the OA group were higher than those of the control group. In the OA group, the mitochondria of pulmonary cells were shrunken, and the mitochondrial membrane was ruptured. The expression level of PTGS2 mRNA in the OA group was seven folds over that in the control group. Iron overload, GSH depletion and accumulation of MDA were observed in the OA group. Compared with the control group, the protein expression levels of GPX4 and ferritin in lung tissue were down-regulated in the OA group. These results suggest that ferroptosis plays a potential role in the pathogenesis of ALI in our mouse model, which may provide new insights for development of new drugs for ALI.
Acute Lung Injury ; chemically induced ; pathology ; Animals ; Apoptosis ; Bronchoalveolar Lavage Fluid ; chemistry ; Cyclooxygenase 2 ; metabolism ; Ferritins ; metabolism ; Glutathione ; analysis ; Glutathione Peroxidase ; metabolism ; Iron ; analysis ; Iron Overload ; physiopathology ; Lung ; cytology ; pathology ; Malondialdehyde ; analysis ; Mice ; Microscopy, Electron, Transmission ; Mitochondrial Membranes ; ultrastructure ; Oleic Acid

Erythrocytes ; metabolism ; Humans ; Kidney Diseases ; genetics ; metabolism ; Mitochondria ; genetics ; Mitochondrial Membranes ; metabolism ; Oxidative Stress ; genetics ; physiology

BACKGROUND AND PURPOSE: The pathogenesis of mitochondrial disease (MD) involves the disruption of cellular energy metabolism, which results from defects in the mitochondrial respiratory chain complex (MRC). We investigated whether infants with MRC I defects showed ultrastructural changes in skeletal muscle. METHODS: Twelve infants were enrolled in this study. They were initially evaluated for unexplained neurodegenerative symptoms, myopathies, or other progressive multiorgan involvement, and underwent muscle biopsies when MD was suspected. Muscle tissue samples were subjected to biochemical enzyme assays and observation by transmission electron microscopy. We compared and analyzed the ultrastructure of skeletal muscle tissues obtained from patients with and without MRC I defects. RESULTS: Biochemical enzyme assays confirmed the presence of MRC I defects in 7 of the 12 patients. Larger mitochondria, lipid droplets, and fused structures between the outer mitochondrial membrane and lipid droplets were observed in the skeletal muscles of patients with MRC I defects. CONCLUSIONS: Mitochondrial functional defects in MRC I disrupt certain activities related to adenosine triphosphate synthesis that produce changes in the skeletal muscle. The ultrastructural changes observed in the infants in this study might serve as unique markers for the detection of MD.
Adenosine Triphosphate ; Biopsy ; Electron Transport* ; Energy Metabolism ; Enzyme Assays ; Humans ; Infant* ; Lipid Droplets ; Microscopy, Electron, Transmission ; Mitochondria ; Mitochondrial Diseases ; Mitochondrial Membranes ; Muscle, Skeletal* ; Muscular Diseases

Mammalian mitochondrial genome encodes a small set of tRNAs, rRNAs, and mRNAs. The RNA synthesis process has been well characterized. How the RNAs are degraded, however, is poorly understood. It was long assumed that the degradation happens in the matrix where transcription and translation machineries reside. Here we show that contrary to the assumption, mammalian mitochondrial RNA degradation occurs in the mitochondrial intermembrane space (IMS) and the IMS-localized RNASET2 is the enzyme that degrades the RNAs. This provides a new paradigm for understanding mitochondrial RNA metabolism and transport.
Cell Line ; Humans ; Mitochondrial Membranes ; metabolism ; Protein Transport ; RNA ; biosynthesis ; chemistry ; metabolism ; RNA Stability ; RNA, Mitochondrial ; Ribonucleases ; metabolism ; Tumor Suppressor Proteins ; metabolism

A small proportion of cancer cells have stem-cell-like properties, are resistant to standard therapy and are associated with a poor prognosis. The metabolism of such drug-resistant cells differs from that of nearby non-resistant cells. In this study, the metabolism of drug-resistant lung adenocarcinoma cells was investigated. The expression of genes associated with oxidative phosphorylation in the mitochondrial membrane was negatively correlated with the prognosis of lung adenocarcinoma. Because the mitochondrial membrane potential (MMP) reflects the functional status of mitochondria and metastasis is the principal cause of death due to cancer, the relationship between MMP and metastasis was evaluated. Cells with a higher MMP exhibited greater migration and invasion than those with a lower MMP. Cells that survived treatment with cisplatin, a standard chemotherapeutic drug for lung adenocarcinoma, exhibited increased MMP and enhanced migration and invasion compared with parental cells. Consistent with these findings, inhibition of mitochondrial activity significantly impeded the migration and invasion of cisplatin-resistant cells. RNA-sequencing analysis indicated that the expression of mitochondrial complex genes was upregulated in cisplatin-resistant cells. These results suggested that drug-resistant cells have a greater MMP and that inhibition of mitochondrial activity could be used to prevent metastasis of drug-resistant lung adenocarcinoma cells.
Adenocarcinoma* ; Cause of Death ; Cisplatin ; Humans ; Lung* ; Membrane Potential, Mitochondrial ; Metabolism ; Mitochondria ; Mitochondrial Membranes ; Neoplasm Metastasis ; Oxidative Phosphorylation ; Parents ; Prognosis

OBJECTIVETo observe the effects of water extract of Zuojin Pill ([characters: see text], ZJP) on inhibiting the growth of human gastric cancer cell line SGC-7901 and its potential mechanism.

METHODSEffects of ZJP on SGC-7901 cells growth were determined by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT) assay, cell apoptosis and cell cycle were determined by flow cytometry, and apoptosis induction was detected by means of DNA gel electrophoresis. The cellular mechanism of drug-induced cell death was unraveled by assaying oxidative injury level of SGC-7901 cell, mitochondrial membrane potentials, expression of apoptosis-related genes, such as B cell lymphoma/lewkmia-2 (Bcl-2), Bcl-2 associated X protein (Bax) and cleaved caspase-3 and caspase-9.

RESULTSZJP exerted evident inhibitory effect on SGC-7901 cells by activating production of reactive oxygen species and elevating Bax/Bcl-2 ratio in SGC-7901 cells, leading to attenuation of mitochondrial membrane potential and DNA fragmentation.

CONCLUSIONSZJP inhibits the cancer cell growth via activating mitochondria-dependent apoptosis pathway. ZJP can potentially serve as an antitumor agent.

Antineoplastic Agents ; pharmacology ; Apoptosis ; drug effects ; Blotting, Western ; Cell Line, Tumor ; Cell Survival ; Colorimetry ; Comet Assay ; DNA Fragmentation ; Drugs, Chinese Herbal ; pharmacology ; Flow Cytometry ; Humans ; Mitochondrial Membranes ; drug effects ; Reactive Oxygen Species ; metabolism