The mechanism of action of mitochondrial dysfunction in the development of non-alcoholic fatty liver disease / 临床肝胆病杂志

Nonalcoholic fatty liver disease （NAFLD） has gradually become the main reason affecting human liver health， and many factors are involved in the development and progression of NAFLD. Mitochondria， as the “energy factory” of cells， plays an important role in maintaining normal physiological functions. Studies have shown that hepatic mitochondrial dysfunction promotes the development and progression of NAFLD. This article briefly introduces the latest research advances in the basic characteristics and physiological function of liver mitochondria and reviews new research findings in the association of mitochondrial dysfunction with obesity， simple fatty liver disease， and nonalcoholic steatohepatitis， in order to provide new ideas for the research on targeted mitochondrial therapy for NAFLD.

Traditional Chinese Medicine Regulating Mitochondrial Function in Prevention and Treatment of Liver Failure：A Review / 中国实验方剂学杂志

Liver failure （LF）， as a clinical syndrome of severe hepatocyte damage and liver dysfunction， has become a major obstacle to human health due to the triple superposition of high mortality， high morbidity， and high medical resource depletion. It is of great significance to further study the core factors of the disease and supplementary treatment methods to improve the survival rate of patients with LF. The pathogenesis of LF is complex， and mitochondrion is one of the sensitive organelles in hepatocytes and the central link of intracellular energy metabolism. A large number of studies have shown that the structure and function of mitochondria in hepatocytes are changed in LF， and the abnormal structure and function of mitochondria play an important role in the process of LF disease. Among them， multiple factors such as mitochondrial respiratory chain disorder， mitochondrial DNA damage， mitochondrial permeability transition pore opening， mitochondrial quality control imbalance， and mitochondrial oxidative stress are intertwined， forming a complex and unified whole network， which becomes the key node affecting the progression of LF. In recent years， researchers have begun to study drugs that can regulate the function of liver mitochondria to prevent and treat LF. With the deepening of research， traditional Chinese medicine has made breakthroughs in the prevention and treatment of LF. Many studies have confirmed that traditional Chinese medicine can play a role in the prevention and treatment of LF by protecting mitochondrial function， which can be summarized as reducing liver cell damage， inhibiting liver cell death， and promoting liver cell regeneration， so as to effectively compensate for liver function and promote the recovery of liver parenchyma quality and function. This article summarized the structure and function of mitochondria， the relationship between LF and mitochondria， and the research on the intervention of mitochondrial function in the field of traditional Chinese medicine to prevent and treat LF， so as to provide certain ideas and references for the clinical treatment of LF with traditional Chinese medicine.

Effect of Endometriosis on Cumulus ATP, Number of Mitochondria and Oocyte Maturity in Cumulus Oocyte Complex in Mice / Efeito da endometriose no cumulus ATP, número de mitocôndrias e maturidade oocitária no complexo oocitário cumulus em camundongos

Abstract Objective Endometriosis causes a decrease in oocyte quality. However, this mechanism is not fully understood. The present study aimed to analyze the effect of endometriosis on cumulus cell adenosine triphosphate ATP level, the number of mitochondria, and the oocyte maturity level. Methods A true experimental study with a post-test only control group design on experimental animals. Thirty-two mice were divided into control and endometriosis groups. Cumulus oocyte complex (COC) was obtained from all groups. Adenosine triphosphate level on cumulus cells was examined using the Elisa technique, the number of mitochondria was evaluated with a confocal laser scanning microscope and the oocyte maturity level was evaluated with an inverted microscope. Results The ATP level of cumulus cells and the number of mitochondria in the endometriosis group increased significantly (p < 0.05; p < 0.05) while the oocyte maturity level was significantly lower (p < 0.05). There was a significant relationship between ATP level of cumulus cells and the number of mitochondrial oocyte (p < 0.01). There was no significant relationship between cumulus cell ATP level and the number of mitochondrial oocytes with oocyte maturity level (p > 0.01; p > 0.01). The ROC curve showed that the number of mitochondrial oocytes (AUC = 0.672) tended to be more accurate than cumulus cell ATP level (AUC = 0.656) in determining the oocyte maturity level. Conclusion In endometriosis model mice, the ATP level of cumulus cells and the number of mitochondrial oocytes increased while the oocyte maturity level decreased. There was a correlation between the increase in ATP level of cumulus cells and an increase in the number of mitochondrial oocytes.

Over-expression of gastrin inhibits apoptosis of gastric cancer cells via reactive oxygen species and annexin A2-mediated mitochondrial dysfunction / La sobreexpresión de gastrina inhibe la apoptosis de las células de cáncer gástrico a través de especies reactivas de oxígeno y disfunción mitocondrial mediada por anexina A2

SUMMARY: Gastrin plays a vital role in the development and progression of gastric cancer (GC). Its expression is up-regulated in GC tissues and several GC cell lines. Yet, the underlying mechanism remains to be investigated. Here, we aim to investigate the role and mechanism of gastrin in GC proliferation. Gastrin-overexpressing GC cell model was constructed using SGC7901 cells. Then the differentially expressed proteins were identified by iTRAQ analysis. Next, we use flow cytometry and immunofluorescence to study the effect of gastrin on the mitochondrial potential and mitochondria-derived ROS production. Finally, we studied the underlying mechanism of gastrin regulating mitochondrial function using Co-IP, mass spectrometry and immunofluorescence. Overexpression of gastrin promoted GC cell proliferation in vitro and in vivo. A total of 173 proteins were expressed differently between the controls and gastrin- overexpression cells and most of these proteins were involved in tumorigenesis and cell proliferation. Among them, Cox17, Cox5B and ATP5J that were all localized to the mitochondrial respiratory chain were down-regulated in gastrin-overexpression cells. Furthermore, gastrin overexpression led to mitochondrial potential decrease and mitochondria-derived ROS increase. Additionally, gastrin-induced ROS generation resulted in the inhibition of cell apoptosis via activating NF-kB, inhibiting Bax expression and promoting Bcl-2 expression. Finally, we found gastrin interacted with mitochondrial membrane protein Annexin A2 using Co-IP and mass spectrometry. Overexpr ession of gastrin inhibits GC cell apoptosis by inducing mitochondrial dysfunction through interacting with mitochondrial protein Annexin A2, then up-regulating ROS production to activate NF-kB and further leading to Bax/Bcl-2 ratio decrease.

La gastrina juega un papel vital en el desarrollo y progresión del cáncer gástrico (CG). Su expresión está regulada al alza en tejidos de CG y en varias líneas celulares de CG. Sin embargo, el mecanismo subyacente aun no se ha investigado. El objetivo de este estudio fue investigar el papel y el mecanismo de la gastrina en la proliferación de CG. El modelo de células CG que sobre expresan gastrina se construyó usando células SGC7901. Luego, las proteínas expresadas diferencialmente se identificaron mediante análisis iTRAQ. A continuación, utilizamos la citometría de flujo y la inmunofluorescencia para estudiar el efecto de la gastrina en el potencial mitocondrial y la producción de ROS derivada de las mitocondrias. Finalmente, estudiamos el mecanismo subyacente de la gastrina que regula la función mitocondrial utilizando Co-IP, espectrometría de masas e inmunofluorescencia. La sobreexpresión de gastrina promovió la proliferación de células CG in vitro e in vivo. Un total de 173 proteínas se expresaron de manera diferente entre los controles y las células con sobreexpresión de gastrina y la mayoría de estas proteínas estaban implicadas en la tumorigenesis y la proliferación celular. Entre estas, Cox17, Cox5B y ATP5J, todas localizadas en la cadena respiratoria mitocondrial, estaban reguladas a la baja en las células con sobreexpresión de gastrina. Además, la sobreexpresión de gastrina provocó una disminución del potencial mitocondrial y un aumento de las ROS derivadas de las mitocondrias. Por otra parte, la generación de ROS inducida por gastrina resultó en la inhibición de la apoptosis celular mediante la activación de NF-kB, inhibiendo la expresión de Bax y promoviendo la expresión de Bcl-2. Finalmente, encontramos que la gastrina interactuaba con la proteína de membrana mitocondrial Anexina A2 usando Co-IP y espectrometría de masas. La sobreexpresión de gastrina inhibe la apoptosis de las células CG al inducir la disfunción mitocondrial a través de la interacción con la proteína mitocondrial Anexina A2, luego regula el aumento de la producción de ROS para activar NF-kB y conduce aún más a la disminución de la relación Bax/Bcl-2.

Coordinated Regulation of Myelination by Growth Factor and Amino-acid Signaling Pathways / 神经科学通报·英文版

Myelin-forming oligodendrocytes in the central nervous system (CNS) and Schwann cells in the peripheral nervous system (PNS) are essential for structural and functional homeostasis of nervous tissue. Albeit with certain similarities, the regulation of CNS and PNS myelination is executed differently. Recent advances highlight the coordinated regulation of oligodendrocyte myelination by amino-acid sensing and growth factor signaling pathways. In this review, we discuss novel insights into the understanding of differential regulation of oligodendrocyte and Schwann cell biology in CNS and PNS myelination, with particular focus on the roles of growth factor-stimulated RHEB-mTORC1 and GATOR2-mediated amino-acid sensing/signaling pathways. We also discuss recent progress on the metabolic regulation of oligodendrocytes and Schwann cells and the impact of their dysfunction on neuronal function and disease.

AIFM1 variants associated with auditory neuropathy spectrum disorder cause apoptosis due to impaired apoptosis-inducing factor dimerization / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Auditory neuropathy spectrum disorder (ANSD) represents a variety of sensorineural deafness conditions characterized by abnormal inner hair cells and/or auditory nerve function, but with the preservation of outer hair cell function. ANSD represents up to 15% of individuals with hearing impairments. Through mutation screening, bioinformatic analysis and expression studies, we have previously identified several apoptosis-inducing factor (AIF) mitochondria-associated 1 (AIFM1) variants in ANSD families and in some other sporadic cases. Here, to elucidate the pathogenic mechanisms underlying each AIFM1 variant, we generated AIF-null cells using the clustered regularly interspersed short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) system and constructed AIF-wild type (WT) and AIF-mutant (mut) (p.‍T260A, p.‍R422W, and p.‍R451Q) stable transfection cell lines. We then analyzed AIF structure, coenzyme-binding affinity, apoptosis, and other aspects. Results revealed that these variants resulted in impaired dimerization, compromising AIF function. The reduction reaction of AIF variants had proceeded slower than that of AIF-WT. The average levels of AIF dimerization in AIF variant cells were only 34.5%‍‒‍49.7% of that of AIF-WT cells, resulting in caspase-independent apoptosis. The average percentage of apoptotic cells in the variants was 12.3%‍‒‍17.9%, which was significantly higher than that (6.9%‍‒‍7.4%) in controls. However, nicotinamide adenine dinucleotide (NADH) treatment promoted the reduction of apoptosis by rescuing AIF dimerization in AIF variant cells. Our findings show that the impairment of AIF dimerization by AIFM1 variants causes apoptosis contributing to ANSD, and introduce NADH as a potential drug for ANSD treatment. Our results help elucidate the mechanisms of ANSD and may lead to the provision of novel therapies.

Flavonoid-Rich Extract of Oldenlandia diffusa (Willd.) Roxb. Inhibits Gastric Cancer by Activation of Caspase-Dependent Mitochondrial Apoptosis / 中国结合医学杂志

OBJECTIVE@#To evaluate the apoptosis and cycle arrest effects of Oldenlandia diffusa flavonoids on human gastric cancer cells, determine the action mechanisms in association with the mitochondrial dependent signal transduction pathway that controls production of reactive oxygen species (ROS), and evaluate the pharmacodynamics of a mouse xenotransplantation model to provide a reference for the use of flavonoids in prevention and treatment of gastric cancer.@*METHODS@#Flavonoids were extracted by an enzymatic-ultrasonic assisted method and purified with D-101 resin. Bioactive components were characterized by high-performance liquid chromatography. Cell lines MKN-45, AGS, and GES-1 were treated with different concentrations of flavonoids (64, 96, 128, 160 µg/mL). The effect of flavonoids on cell viability was evaluated by MTT method, and cell nuclear morphology was observed by Hoechst staining. The apoptosis rate and cell cycle phases were measured by flow cytometry, the production of ROS was detected by laser confocal microscope, the mitochondrial membrane potential (MMP) were observed by fluorescence microscope, and the expression of apoptotic proteins related to activation of mitochondrial pathway were measured by immunoblotting. MKN-45 cells were transplanted into BALB/c nude mice to establish a xenograft tumor model. Hematoxylin and eosin staining was used to reveal the subcutaneous tumor tissue. The tumor volume and tumor weight were measured, the expression levels of proliferation markers proliferating cell nuclear antigen (PCNA) and Ki-67 were detected by immunohistochemistry, and the expression levels of CA72-4 were measured by enzyme linked immunosorbent assay.@*RESULTS@#Oldenlandia diffusa flavonoids inhibited proliferation of MKN-45 and AGS human gastric cancer cells, arrested the cell cycle in G1/S phase, induced accumulation of ROS in the process of apoptosis, and altered MMP. In addition, flavonoids increased Apaf-1, Cleaved-Caspase-3, and Bax, and decreased Cyclin A, Cdk2, Bcl-2, Pro-Caspase-9, and Mitochondrial Cytochrome C (P<0.05). The MKN-45 cell mouse xenotransplantation model further clarified the growth inhibitory effect of flavonoids towards tumors. The expression levels of PCNA and Ki-67 decreased in each flavonoid dose group, the expression level of CA72-4 decreased (P<0.05).@*CONCLUSION@#Flavonoids derived from Oldenlandia diffusa can inhibit proliferation and induce apoptosis of human gastric cancer cells by activating the mitochondrial controlled signal transduction pathway.

Regulation of AMPA receptor on propofol induced hippocampal mitochondrial injury in neonatal rats / 中华危重病急救医学

Objective:To investigate whether propofol can cause injury to hippocampal mitochondria in neonatal rats and the regulation of excitatory amino acid receptor AMPA receptor.Methods:Forty-eight Sprague-Dawley (SD) rats aged 7 days were randomly divided into control group, propofol group, propofol+AMPA receptor agonist AMPA group (propofol+AMPA group) and propofol+AMPA receptor inhibitor CNQX group (propofol+CNQX group), with 12 rats in each group. The rats in the propofol groups were intraperitoneally injected with 30 mg/kg propofol, while in control group with 3 mg/kg normal saline. Each group was given 1/2 of the first dose every 20 minutes after the first administration, three times a day, for three consecutive days. The rats in the propofol+AMPA group and the propofol+CNQX group were injected with 1 g/L AMPA or CNQX 5 μL through left ventricle after the first administration. Three days after administration, the rats were sacrificed to obtain brain tissue. Western blotting was used to determine the expression of AMPA receptor glutamate receptors (GluR1, GluR2) subunit totally (T) and on membrane (M) in hippocampus. The expression of dynamin-related protein-1 (DRP-1) and phosphorylated-DRP-1 (p-DRP-1) and mitofusin 2 (Mfn2) related to mitochondrial fission and fusion were determined. The adenosine triphosphate (ATP) content and ATPase activity were determined.Results:Compared with the control group, GluR1 expression and its M/T ratio were significantly increased after treatment of propofol, GluR2 expression and its M/T ratio were significantly decreased, the ATP content and ATP-related enzyme activity were decreased significantly, while the expression of DRP-1 and its phosphorylation was significantly increased, and the expression of Mfn2 was significantly decreased. The changes indicated that repeated intraperitoneal injection of 30 mg/kg propofol leading to the injury of mitochondria in neural cells. Compared with the propofol group, the GluR1 expression and its M/T ratio further increased after AMPA agonist administration [T-GluR1 protein (T-GluR1/β-actin): 2.41±0.29 vs. 1.72±0.11, M-GluR1 protein (M-GluR1/β-actin): 1.18±0.15 vs. 0.79±0.09, M/T ratio: 0.78±0.12 vs. 0.46±0.08, all P < 0.01], GluR2 expression was significantly increased [T-GluR2 protein (T-GluR2/β-actin): 0.65±0.13 vs. 0.30±0.14, P < 0.01; M-GluR2 protein (M-GluR2/β-actin): 0.17±0.05 vs. 0.13±0.07, P > 0.05], but its M/T ratio was further decreased (0.27±0.10 vs. 0.41±0.08, P < 0.05). The ATP-related enzyme activity was further decreased, and the ATP content was further decreased (μmol/g: 0.32±0.07 vs. 0.70±0.10, P < 0.01). Mitochondria DRP-1 expression and its phosphorylation were further increased [DRP-1 protein (DRP-1/GAPDH): 2.75±0.36 vs. 1.70±0.19, p-DRP-1 protein (p-DRP-1/GAPDH): 0.99±0.14 vs. 0.76±0.15, both P < 0.05], and Mfn2 expression was further decreased (Mfn2/GAPDH: 0.23±0.12 vs. 0.54±0.12, P < 0.05). This indicated that the AMPA agonist increased the expression of the AMPA receptor GluR1 subunit on the cell membrane and shifted the GluR2 into the cell, thus increasing the mitochondrial injury caused by propofol. Compared with the propofol group, the GluR1 expression and its M/T ratio decreased significantly after AMPA inhibitor administration [T-GluR1 protein (T-GluR1/β-actin): 0.99±0.14 vs. 1.72±0.11, M-GluR1 protein (M-GluR1/β-actin): 0.21±0.07 vs. 0.79±0.09, M/T ratio: 0.21±0.07 vs. 0.46±0.08, all P < 0.01], the change of GluR2 expression was not significant, but its M/T ratio was significantly increased (0.59±0.09 vs. 0.41±0.08, P < 0.05). The ATP-related enzyme activity was increased significantly, and the ATP content was increased significantly (μmol/g: 0.87±0.12 vs. 0.70±0.10, P < 0.05). Mitochondria DRP-1 expression and its phosphorylation were significantly decreased [DRP-1 protein (DRP-1/GAPDH): 1.18±0.17 vs. 1.70±0.19, p-DRP-1 protein (p-DRP-1/GAPDH): 0.37±0.10 vs. 0.76±0.10, both P < 0.05], and Mfn2 expression was significantly increased (Mfn2/GAPDH: 0.78±0.10 vs. 0.54±0.12, P < 0.05). This indicated that AMPA inhibitor promoted the movement to the cell membrane of GluR2 subunits meanwhile inhibited the expression of GluR1 subunits, thus alleviating the injury of mitochondrial caused by propofol in the brain. Conclusions:Repeated intraperitoneal injection of 30 mg/kg propofol for 3 days can increase the expression of GluR1 subunits of AMPA receptor in 7-day neonatal rats hippocampus mainly distributing in the cell membrane, decrease the expression of GluR2 subunits moving into the cell, thus causing injury of mitochondrial function and dynamics, which can be aggravated by AMPA receptor agonist and alleviated by AMPA receptor inhibitors.

Research progress on the skeletal muscle mitochondrial alterations and the treatment in cancer cachexia / 中华临床营养杂志

Cancer cachexia is a multifactorial syndrome characterized by the continuous loss of skeletal muscle. The pathogenic mechanism of cancer cachexia remains unknown, and the effectiveness of routine nutritional therapy is limited. The mitochondrial disorder is demonstrated to play an important role in the mechanism of tumor-induced skeletal muscle atrophy, including alterations to the mitochondrial ultrastructure, biogenesis, dynamics, mitophagy, and functions. Interventions targeting mitochondrial alterations provide a potential solution to cancer cachexia and represent a new focus in this research field.

Characteristics and clinical significance of mitochondrial injury of T lymphocyte subsets in patients with autoimmune hepatitis / 中国医师进修杂志

Objective:To study the characteristics and clinical significance of mitochondrial injury of T lymphocyte subsets in patients with autoimmune hepatitis (AIH).Methods:The clinical data of 57 patients with AIH (AIH group) from June to December 2021 in Hangzhou Xixi Hospital were retrospectively analyzed, while 60 healthy physical examiners were included as healthy group. The peripheral blood T lymphocyte subsets (CD 8+ T lymphocyte count and CD 4+ T lymphocyte count) were detected by flow cytometry, and matched mitochondrial staining value according to certain algorithm was used to determine the mitochondrial damage of helper T lymphocyte (Th cell) and suppressor T lymphocyte (Ts cell). The levels of IgG, alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were measured using a Roche E170 automatic electrochemiluminescence immunoassay. Anti-nuclear antibody (ANA) titer was measured by immunofluorescence. Multivariate Logistic regression was used to analyze the independent risk factors of mitochondrial damage of Th cell and Ts cell in patients with AIH. Results:The ALT, AST, IgG, positive rate of ANA titer, CD 4+ T lymphocyte count, CD 8+ T lymphocyte count, rate of Th cell mitochondrial injury and rate of Ts cell mitochondrial injury in AIH group were significantly higher than those in healthy group: (118.90 ± 37.61) U/L vs. (30.96 ± 14.37) U/L, (102.40 ± 36.51) U/L vs. (31.12 ± 14.06) U/L, (18.40 ± 3.71) g/L vs. (13.89 ± 1.98) g/L, 96.49% (55/57) vs. 16.67% (10/60), 438 (323, 637) × 10 6/L vs. 398 (272, 469) × 10 6/L, 296 (211, 296) × 10 6/L vs. 270 (193, 322) × 10 6/L, 61.40% (35/57) vs. 8.33% (5/60) and 82.46% (47/57) vs. 11.67% (7/60), and there were statistical differences ( P<0.01 or <0.05). Multivariate Logistic regression analysis result showed that the AST elevated and CD 8+ T lymphocyte count reduced were the independent risk factors of Ts cell mitochondrial injury in patients with AIH ( OR = 1.06 and 0.99, 95% CI 1.01 to 1.10 and 0.99 to 1.00, P<0.05); the ALT elevated and IgG elevated were the independent risk factors of Th cell mitochondrial injury in patients with AIH ( OR = 1.08 and 1.66, 95% CI 1.02 to 1.14 and 1.11 to 2.48, P<0.05). Conclusions:It is of positive clinical significance to measure the T lymphocyte subtype mitochondrial injury in patients with AIH. The probability of mitochondrial injury of T lymphocyte subtype can be predicted by biochemical indexes such as ALT, AST and IgG, so as to indirectly evaluate the liver cell necrosis.

PRE-084 ameliorated learning and memory impairment in T1DM via regulating neuronal MAM / 西安交通大学学报(医学版)

【Objective】 Diabetic mice could show learning and memory dysfunction, and we aimed to investigate the effect of Sigma-1 receptor agonist, PRE-084, on neurons and cognitive impairment in mice with type 1 diabetes (T1DM). 【Methods】 Twenty mice with T1DM induced by streptozocin, aged 8-10 weeks, and 20 control mice (CON) were randomly divided into four groups (CON+Vehicle, CON+PRE-084, T1DM+Vehicle and T1DM+PRE-084). Mouse primary neurons were cultured in high glucose medium with PRE-084 and control solvent, respectively. The body weight, food and water intake, and fasting blood glucose level of mice in each group were detected and recorded. The learning and memory abilities of mice were detected by new object recognition experiment. The mitochondria-associated endoplasmic reticulum membrane (MAM) structure of neurons in hippocampal CA1 area of mice was detected by transmission electron microscope. And the expression levels of ATP and reactive oxygen species (ROS) in hippocampus of mice were detected by biochemical kit. Cell viability and ROS level of primary neurons were detected by CCK8 and cellular ROS kit. 【Results】 PRE-084 reduced the increase of body weight, food and water intake, and blood glucose caused by diabetes. PRE-084 significantly ameliorated the learning and memory impairment of the mice with T1DM, improved the changes of MAM structure in neurons of hippocampal CA1 area of diabetic mice, increased the level of ATP in hippocampus of diabetic mice, and decreased the increase of ROS expression in diabetic hippocampus and neurons under high glucose conditions. 【Conclusion】 Sigma-1 receptor agonist, PRE-084, could improve learning and memory impairment in the mice with T1DM, which might be related to the structural changes of MAM, the increase of ATP production, and the decrease of ROS production in hippocampal neurons.

Cytotoxic Activity of Ethanolic Extract Aquilaria malaccensis Leaves Against MCF-7 Cells

@#Introduction: Aquilaria malaccensis, also known as “Pokok Karas” in Malaysia, is widely used in Southeast Asian countries for the treatment of joint pain, diarrhoea and inflammatory diseases, and has shown beneficial effects as an anticancer agent. The aim of this study was to investigate the effect of ethanol leaf extracts of A. malaccensis on MCF-7 cells. Methods: MTT-based cytotoxic and antiproliferative assay was used to determine the outcome of ethanolic extract toward MCF-7 cells. The mode of cell death was determined by the AO/PI double staining assay and the depolarisation of the mitochondria membrane potential. Results: IC50 value of the extract against MCF-7 cells treated for 72 hours was 4.1 ± 2.08 µg/mL, while the IC50 value for doxorubicin was 2.92 ± 0.12 µg/mL. The extract showed a lower cytotoxic effect against the NIH/3T3 cells and inhibited the growth of MCF-7 cells in a dose dependent manner. AO/PI double stain showed that the ethanolic extract of A. malaccensis leaves induced MCF-7 cells into apoptotic cell death. The present study showed that the ethanolic extract of A. malaccensis induced apoptosis through mitochondrial pathway as indicated by its ability to take up JC-1. Conclusion: The study found that ethanolic extract obtained from A. malaccensis leaves is cytotoxic on MCF-7 cells, resulting to apoptotic cell death of the cells.

Research progress of risk factors of Leber’s hereditary optic neuropathy / 中华眼底病杂志

Leber’s hereditary optic neuropathy (LHON) is a paradigm maternal hereditary eye disease, mainly involving the retinal and macular fibers of the optic disc in the anterior ethmoid plate of the sclera. LHON has the characteristics of sex bias among males and incomplete penetrance. Primary mitochondrial DNA mutations m.11778G>A, m. 14484T>C, m.3460G>A are the molecular basis of LHON. However, other risk factors, such as secondary mitochondrial DNA mutations, mitochondrial haplotypes, nuclear modification genes, estrogen, vitamin B12 and environmental factors, work together to affect its phenotypic expression. The clinical diagnosis of LHON mainly limited to the detection of the primary mutation site of mitochondrial DNA. Therefore, comprehensive analysis of multiple risk factors of LHON will facilitate to construct multi-dimensional model of prevention, diagnosis and treatment system, which provide accurate and individualized medical services for patients. These may alleviate the incidence in LHON families. It also provides new ideas and different angles for the in-depth study of the pathogenesis of LHON.

Relationship between BNIP3L and mitochondrial dysfunction in hippocampus of mice with sepsis-associated encephalopathy / 中华麻醉学杂志

Objective:To evaluate the relationship between B-cell lymphoma/adenovirus E1B19 kDa-interacting protein 3-like protein (BNIP3L)/adenovirus E1B-interacting protein and mitochondrial dysfunction in the hippocampus of mice with sepsis-associated encephalopathy (SAE).Methods:One hundred and eighty C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=45 each) using a random number table method: control group (C group), sham operation group (Sham group), SAE group, and SAE+ BNIP3L agonist carfilzomib group (SC group). The sepsis model was developed by cecal ligation and puncture (CLP) in anesthetized animals. In SC group, carfilzomib 2 mg/kg was intraperitoneally injected at 2 h after CLP. Twenty mice in each group were selected, and the survival at 7 days after operation was recorded. Eight surviving mice in each group were selected at 1 week after CLP for Morris water maze test. The remaining mice were sacrificed at 24 h after surgery, and the hippocampal tissues were harvested for determination of the expression of BNIP3L (by immunofluorescence) and BNIP3L in mitochondrial protein (by Western blot) and for microscopic examination of the morphological structure of mitochondria. The mitochondrial ATP content was measured by fluorescein-fluorescence enzyme luminescence method, and the mitochondrial membrane potential (MMP) was measured by fluorescence spectrophotometry. Results:Compared with C and Sham groups, the survival rate was significantly decreased, the escape latency was prolonged, the time of staying at the original platform quadrant was shortened, and the number of crossing the original platform region was decreased, the expression of BNIP3L in the hippocampal mitochondria was down-regulated, the MMP and content of mitochondrial ATP were decreased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was marked in SAE group. Compared with SAE group, the survival rate was significantly increased, the escape latency was shortened, the time of staying at the original platform quadrant was prolonged, and the number of crossing the original platform region was increased, the expression of BNIP3L in the hippocampal mitochondria was up-regulated, the MMP and content of mitochondrial ATP were increased ( P<0.05), the intensity of fluorescence of BNIP3L in the hippocampus was decreased, and the damage to mitochondrial ultrastructure was attenuated in SC group. Conclusions:BNIP3L-mediated mitochondrial dysfunction may be involved in the mechanism of SAE developed in mice.

Role of succinate dehydrogenase in hypoxic postconditioning-induced reduction of hypoxia-reoxygenation injury in myocardial cells of rats and the relationship with mito-K ATP / 中华麻醉学杂志

Objective:To evaluate the role of succinate dehydrogenase (SDH) in hypoxic postconditioning (HPC)-induced reduction of hypoxia-reoxygenation (H/R) injury in myocardial cells of rats and the relationship with mitochondrial ATP-sensitive potassium channels (mito-K ATP). Methods:Myocardial cells isolated from adult male Sprague-Dawley rats were cultured for 48 h and then divided into 7 groups ( n=24 each) using a random number table method: blank control group (Nor group), H/R group, SDHA-siRNA adenovirus+ H/R group (siRNA+ H/R group), HPC group, SDHA-siRNA adenovirus+ HPC group (siRNA+ HPC group), 5-HD+ HPC group, and SDHA-siRNA adenovirus+ 5-HD+ HPC group (siRNA+ 5-HD+ HPC group). Nor group was continuously cultured for 195 min under normoxic conditions. The H/R injury model was prepared by exposing the cells to hypoxia for 45 min in 5% CO 2 + 1% O 2 + 94% N 2, followed by reoxygenation for 150 min. The HPC method involved three cycles of 5 min reoxygenation/5 min hypoxia at the end of 45 min ischemia before 120 min reoxygenation. The mito-K ATP blocker 5-HD administration method involved adding 5-HD at a final concentration of 100 μmol/L at 30 min of hypoxia. The myocardial cells in each siRNA group were successfully transfected with SDHA-siRNA adenovirus to silence SDHA expression. The cell viability, calcium ion level, SDH activity, ATP content, degree of mitochondrial permeability transition pore (mPTP) opening, and mitochondrial membrane potential (MMP) were measured at the end of reoxygenation. Results:Compared with Nor group, the cell viability, ATP content and MMP were significantly decreased, and the degree of mPTP opening, level of calcium ion and activity of SDH were increased in H/R group ( P<0.05). Compared with H/R group, the cell viability, ATP content and MMP were significantly increased, and the degree of mPTP opening, calcium ion level and SDH activity were decreased in siRNA+ H/R group and HPC group ( P<0.05). Compared with HPC group, the cell viability, ATP content and MMP were significantly decreased, and the degree of mPTP opening, calcium ion level and SDH activity were increased in 5-HD+ HPC group ( P<0.05), and the cell viability, ATP content and MMP were significantly increased, and the degree of mPTP opening, calcium ion level and SDH activity were decreased in siRNA+ HPC group ( P<0.05). Compared with siRNA+ HPC group, the cell viability, ATP content and MMP were significantly decreased, the opening degree of mPTP and calcium ion level were increased ( P<0.05), and no significant change was found in the SDH activity in siRNA+ 5-HD+ HPC group ( P>0.05). Compared with 5-HD+ HPC group, the SDH activity was significantly decreased, and no significant change was found in the other parameters in siRNA+ 5-HD+ HPC group ( P>0.05). Conclusions:HPC alleviates H/R injury probably by reducing SDH activity and opening mito-K ATP in myocardial cells of rats.

Role of SIRT1 in mitochondrial dysfunction in mice with lipopolysaccharide-induced brain injury / 中华麻醉学杂志

Objective:To evaluate the role of silent information regulator sirtuin 1 (SIRT1) in mitochondrial dysfunction in mice with lipopolysaccharide (LPS)-induced brain injury.Methods:Eighty clean-grade male C57BL/6 mice, aged 6-8 weeks, were divided into 4 groups ( n=20 each) by the random number table method: control group (group C), LPS-induced brain injury group (LPS group), LPS-induced brain injury plus SIRT1 inhibitor EX527 group (LPS+ E group), and LPS-induced brain injury plus SIRT1 agonist SRT1720 group (LPS+ S group). Brain injury was induced by intravenous injection of LPS 10 mg/kg. EX527 10 mg/kg was intraperitoneally injected at 72 h before LPS injection in group LPS+ E, and the equal volume of dimethyl sulfoxide was intraperitoneally injected instead in the other three groups. SRT1720 100 mg/kg was intraperitoneally injected at 30 min before LPS injection in group LPS+ S, and the equal volume of dimethyl sulfoxide was intraperitoneally injected instead in the other three groups. The novel object recognition test was performed at 24 h after LPS injection, then the mice were sacrificed, and hippocampal tissues were harvested for determination of the number of the normal neurons in the hippocampal CA1 area, ATP content and activities of mitochondrial respiratory chain complexes Ⅰ, Ⅱ, Ⅲ and Ⅳ (by spectrophotometry), and mitochondrial membrane potential (MMP) (by Jc-1 staining) and for microscopic examination of pathological changes (by Nissl staining) and ultrastructure of neuronal mitochondria (with a transmission electron microscope). Results:Compared with group C, the preference index in novel object recognition, normal neuron count, activities of mitochondrial respiratory chain complexes Ⅰ, Ⅱ, Ⅲ and Ⅳ, MMP and ATP content were significantly decreased ( P<0.05), damage to hippocampal neurons was found, mitochondrial swelling was observed and cristae structure ruptured in LPS, LPS+ S and LPS+ E groups. Compared with group LPS, the preference index in novel object recognition, activities of mitochondrial respiratory chain complexes, MMP and ATP content were significantly decreased ( P<0.05), neuronal damage was aggravated, the mitochondrial swelling and fracture of crista structure were accentuated in group LPS+ E; the preference index in novel object recognition, activities of mitochondrial respiratory chain complexes, MMP and ATP content were significantly increased ( P<0.05), neuronal damage was alleviated, and the mitochondrial swelling and fracture of crista structure were ameliorated in group LPS+ S. Conclusions:Activation of SIRT1 can improve mitochondrial dysfunction and alleviate LPS-induced brain injury in mice.

Effects of inhalation of high-concentration hydrogen on acute kidney injury and mitochondrial dynamics in septic mice / 中华麻醉学杂志

Objective:To evaluate the effects of inhalation of high-concentration hydrogen on acute kidney injury (AKI) and mitochondrial dynamics in septic mice.Methods:One hundred and twenty-eight male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=32 each) using a random number table method: sham operation group (group Sham), sham operation + hydrogen group (group Sham+ H), sepsis AKI group, and sepsis AKI+ hydrogen group (group S-AKI+ H). A mouse model of sepsis-induced AKI was developed by cecal ligation and puncture in anesthetized animals. In Sham+ H and S-AKI+ H groups, 67% H 2+ 33% O 2 was inhaled for 1 h starting from 1 and 6 h after sham operation or developing the model, respectively. Twenty mice were selected to observe the survival at 7 days after developing the model. At 24 h after developing the model, blood samples were collected for determination of serum BUN and Cr concentrations (by colorimetric analysis), and renal tissues were obtained for determination of the contents of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and high mobility group protein B1 (HMGB1) (by enzyme-linked immunosorbent assay), activities of superoxide dismutase (SOD) and catalase (CAT) (by spectrophotometry) and expression of dynamin-related protein 1 (Drp1) and mitofusin 2 (Mfn2) (by Western blot). The damage to the renal tubules was scored after HE staining. Results:Compared with Sham group, the survival rate was significantly decreased, the serum BUN and Cr concentrations, renal tubular damage score and contents of TNF-α, IL-1β and HMGB1 were increased, the activities of SOD and CAT were decreased, the expression of Drp1 was up-regulated, and the expression of Mfn2 was down-regulated in S-AKI group ( P<0.05), and no significant change was found in the parameters mentioned above in Sham+ H group ( P>0.05). Compared with S-AKI group, the survival rate was significantly increased, the serum BUN and Cr concentrations, renal tubular injury score and contents of TNF-α, IL-1β and HMGB1 were decreased, the activities of SOD and CAT were increased, the expression of Drp1 was down-regulated, and the expression of Mfn2 was up-regulated in S-AKI+ H group ( P<0.05). Conclusions:Inhalation of high-concentration hydrogen can alleviate AKI in septic mice, and the mechanism may be related to inhibition of renal mitochondrial fission and promotion of mitochondrial fusion.

Effects of inhaling high concentration hydrogen on myocardial injury and mitochondrial biogenesis in septic mice / 中华麻醉学杂志

Objective:To evaluate the effects of inhaling high concentration hydrogen on myocardial injury and mitochondrial biogenesis in septic mice.Methods:One hundred and twenty-eight clean-grade healthy male C57BL/6J mice, aged 6-8 weeks, weighing 20-25 g, were divided into 4 groups ( n=32 each) using a random number table method: sham operation group (group Sham), sham operation + hydrogen group (group Sham+ H), sepsis group (group Sep), and sepsis+ hydrogen group (group Sep+ H). The sepsis model was developed by cecal ligation and puncture in anesthetized animals. In Sham+ H and Sep+ H groups, 67% H 2 was inhaled for 1 h starting from 1 and 6 h after operation, respectively. Twenty mice in each group were randomly selected to observe the survival conditions at 7 days after operation. Blood samples were taken from the remaining mice at 24 h after operation for determination of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), cardiac troponin I (cTnI) and creatine kinase isoenzyme (CK-MB) (by enzyme-linked immunosorbent assay), for examination of the pathological changes of myocardial tissues (by HE staining), and for determination of the mitochondrial membrane potential (MMP) (by fluorescence spectrophotometry), ATP content (by luciferase assay), and expression of myocardial peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α), nuclear respiratory factor 2 (NRF2) and mitochondrial transcription factor A (TFAM) (by Western blot). Results:Compared with Sham group, the survival rate was significantly decreased, the serum concentrations of TNF-α, IL-1β, cTnI and CK-MB and pathological score were increased, the MMP and content of ATP in myocardial mitochondria were decreased, and the expression of PGC-1α, NRF2 and TFAM in myocardial tissues was down-regulated in Sep group ( P<0.05), and no significant change was found in the parameters mentioned above in Sham+ H group ( P>0.05). Compared with group Sep, the survival rate was significantly increased, the serum concentrations of TNF-α, IL-1β, cTnI and CK-MB and pathological score were decreased, the MMP and content of ATP in myocardial mitochondria were increased, and the expression of PGC-1α, NRF2 and TFAM in myocardial tissues was up-regulated in group Sep+ H ( P<0.05). Conclusions:Inhaling high concentration hydrogen can attenuate sepsis-induced myocardial injury in mice, and the mechanism may be related to promotion of mitochondrial biosynthesis and improvement in mitochondrial function.

Irisin and skeletal muscle mitochondrial function and sarcopenia / 中华老年医学杂志

Irisin is a muscle factor that plays a crucial role in exercise-induced metabolic responses.Recent studies have revealed that it can boost the metabolic rate of both myocytes and adipocytes, while also enhancing mitochondrial content and dynamics.This ultimately helps to safeguard skeletal muscle, promote muscle growth, and maintain optimal muscle function.Therefore, irisin has the potential to serve as both a predictor and a biomarker for sarcopenia.In this paper, we delve into the impact of irisin on skeletal muscle, specifically exploring the synergistic relationship between irisin and mitochondria.Additionally, we investigate the effectiveness of irisin in reversing and restoring muscle atrophy, ultimately establishing irisin as a valuable target for treating sarcopenia.

Remote ischemic preconditioning-induced late cardioprotection: possible role of melatonin-mitoKATP-H2S signaling pathway

Purpose: Remote ischemic preconditioning (RIPC) confers cardioprotection against ischemia reperfusion (IR) injury. However, the precise mechanisms involved in RIPC-induced cardioprotection are not fully explored. The present study was aimed to identify the role of melatonin in RIPC-induced late cardioprotective effects in rats and to explore the role of H2 S, TNF-α and mitoKATP in melatoninmediated effects in RIPC. Methods: Wistar rats were subjected to RIPC in which hind limb was subjected to four alternate cycles of ischemia and reperfusion of 5 min duration by using a neonatal blood pressure cuff. After 24 h of RIPC or ramelteon-induced pharmacological preconditioning, hearts were isolated and subjected to IR injury on the Langendorff apparatus. Results: RIPC and ramelteon preconditioning protected the hearts from IR injury and it was assessed by a decrease in LDH-1, cTnT and increase in left ventricular developed pressure (LVDP). RIPC increased the melatonin levels (in plasma), H2 S (in heart) and decreased TNF-α levels. The effects of RIPC were abolished in the presence of melatonin receptor blocker (luzindole), ganglionic blocker (hexamethonium) and mitochondrial KATP blocker (5-hydroxydecanoic acid). Conclusion: RIPC produce delayed cardioprotection against IR injury through the activation of neuronal pathway, which may increase the plasma melatonin levels to activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2 S levels. Ramelteon-induced pharmacological preconditioning may also activate the cardioprotective signaling pathway involving the opening of mitochondrial KATP channels, decrease in TNF-α production and increase in H2 S levels.