Ancistrocladus tectorius Extract Inhibits Obesity by Promoting Thermogenesis and Mitochondrial Dynamics in High-Fat Diet-Fed Mice.

Root extracts of Ancistrocladus tectorius (AT), a shrub native to China, have been shown to have antiviral and antitumor activities, but the anti-obesity effects of AT aerial parts, mainly the leaves and stems, have not been investigated. This study is the first to investigate the anti-obesity effects and molecular mechanism of AT 70% ethanol extract in 3T3-L1 adipocytes and high-fat diet (HFD)-fed C57BL/6J mice. Treatment with AT extract inhibited lipid accumulation in 3T3-L1 cells and decreased the expression of adipogenesis-related genes. AT extract also upregulated the mRNA expression of genes related to mitochondrial dynamics in 3T3-L1 adipocytes. AT administration for 12 weeks reduced body weight and organ weights, including liver, pancreas, and white and brown adipose tissue, and improved plasma profiles such as glucose, insulin, homeostasis model assessment of insulin resistance, triglyceride (TG), and total cholesterol in HFD-fed mice. AT extract reduced HFD-induced hepatic steatosis with levels of liver TG and lipogenesis-related genes. AT extract upregulated thermogenesis-related genes such as Cidea, Pgc1α, Ucp1, Prdm16, Adrb1, and Adrb3 and mitochondrial dynamics-related genes such as Mff, Opa1, and Mfn2 in brown adipose tissue (BAT). Therefore, AT extract effectively reduced obesity by promoting thermogenesis and the mitochondrial dynamics of BAT in HFD-fed mice.

DHEA down-regulates mitochondrial dynamics and promotes apoptosis of lung adenocarcinoma cells through FASTKD2.

Background: DHEA is a steroid hormone produced by the gonads, adrenal cortex, brain, and gastrointestinal tract. While the anti-obesity, anti-atherosclerosis, anti-cancer, and memory-enhancing effects of DHEA have been substantiated through cell experiments, animal studies, and human trials, the precise mechanisms underlying these effects remain unclear. Altered mitochondrial dynamics can lead to mitochondrial dysfunction, which is closely related to many human diseases, especially cancer and aging. This study was to investigate whether DHEA inhibits lung adenocarcinoma through the mitochondrial pathway and its molecular mechanism. Methods: Through animal experiments and cell experiments, the effect of DHEA on tumor inhibition was determined. The correlation between FASTKD2 expression and DHEA was analyzed by Western blot, Reverse transcription-quantitative PCR, Immunohistochemistry, and TCGA database. Results: In this study, DHEA supplementation in the diet can inhibit the tumor size of mice, and the effect of adding DHEA one week before the experiment is the best. DHEA limits the glycolysis process by inhibiting G6PDH activity, increases the accumulation of reactive oxygen species, and initiates apoptosis in the mitochondrial pathway of cancer cells. Conclusion: DHEA suppresses mitochondrial fission and promotes mitochondrial fusion by downregulating the expression of FASTKD2, thereby inhibiting tumor growth and prolonging the overall survival of lung adenocarcinoma patients, which also provides a new target for the prevention and treatment of lung adenocarcinoma.

MCU complex: Exploring emerging targets and mechanisms of mitochondrial physiology and pathology.

BACKGROUND: Globally, the onset and progression of multiple human diseases are associated with mitochondrial dysfunction and dysregulation of Ca2+ uptake dynamics mediated by the mitochondrial calcium uniporter (MCU) complex, which plays a key role in mitochondrial dysfunction. Despite relevant studies, the underlying pathophysiological mechanisms have not yet been fully elucidated. AIM OF REVIEW: This article provides an in-depth analysis of the current research status of the MCU complex, focusing on its molecular composition, regulatory mechanisms, and association with diseases. In addition, we conducted an in-depth analysis of the regulatory effects of agonists, inhibitors, and traditional Chinese medicine (TCM) monomers on the MCU complex and their application prospects in disease treatment. From the perspective of medicinal chemistry, we conducted an in-depth analysis of the structure-activity relationship between these small molecules and MCU and deduced potential pharmacophores and binding pockets. Simultaneously, key structural domains of the MCU complex in Homo sapiens were identified. We also studied the functional expression of the MCU complex in Drosophila, Zebrafish, and Caenorhabditis elegans. These analyses provide a basis for exploring potential treatment strategies targeting the MCU complex and provide strong support for the development of future precision medicine and treatments. KEY SCIENTIFIC CONCEPTS OF REVIEW: The MCU complex exhibits varying behavior across different tissues and plays various roles in metabolic functions. It consists of six MCU subunits, an essential MCU regulator (EMRE), and solute carrier 25A23 (SLC25A23). They regulate processes, such as mitochondrial Ca2+ (mCa2+) uptake, mitochondrial adenosine triphosphate (ATP) production, calcium dynamics, oxidative stress (OS), and cell death. Regulation makes it a potential target for treating diseases, especially cardiovascular diseases, neurodegenerative diseases, inflammatory diseases, metabolic diseases, and tumors.

Alpha-ketoglutaric acid attenuates oxidative stress and modulates mitochondrial dynamics and autophagy of spleen in a piglet model of lipopolysaccharide-induced sepsis.

Alpha-ketoglutaric acid (2-ketoglutaric acid or 2-oxoglutaric acid, AKG), a crucial intermediate in the tricarboxylic acid cycle, is pivotal in animal antioxidative process. The purpose of this study was to investigate whether AKG has the efficacy to mitigate spleen oxidative stress in lipopolysaccharide (LPS)-induced sepsis piglets through the modulation of mitochondrial dynamics and autophagy. Utilizing a 2 × 2 factorial design, the study encompassed 24 piglets subjected to varying diets (basal or 1% AKG) and immune stimulations (saline or LPS) over 21 days. Subsequently, they were injected intraperitoneally with either LPS or saline solution. The results showed that LPS decreased antioxidant capacity, whereas AKG supplementation increased antioxidant activities compared to control group. LPS elevated mitochondrial fission factor, mitochondrial elongation factor 1, mitochondrial elongation factor 2, dynamin-related protein 1, voltage-dependent anion channel 1, and fission 1 mRNA abundance, but reduced mRNA abundance of mitofusin 1, mitofusin 2, and optic atrophy 1 compared to controls. LPS elevated mRNA abundance of autophagy related protein 5, autophagy related protein 7, P62, Beclin1, and interleukin-1ß mRNA abundance compared to controls. However, AKG supplementation mitigated these effects induced by LPS. Additionally, AKG intake was associated with lower protein expressions of microtubule-associated protein light chain 3, Parkin, and PTEN-induced putative kinase 1 compared to LPS-challenged piglets. These results suggested that AKG could alleviate spleen oxidative stress caused by LPS by regulating mitochondrial dynamics and autophagy.

Vitamin B12-folic acid supplementation improves memory by altering mitochondrial dynamics, dendritic arborization, and neurodegeneration in old and amnesic male mice.

Memory impairment during aging and amnesia is attributed to compromised mitochondrial dynamics and mitophagy and other mitochondrial quality control mechanisms. Mitochondrial dynamics involves the continuous process of fission and fusion of mitochondria within a cell and is a fundamental mechanism for regulating mitochondrial quality and function. An extensive range of potential nutritional supplements has been shown to improve mitochondrial health, synaptic plasticity, and cognitive functions. Previous findings revealed that supplementation of vitamin B12-folic acid reduces locomotor deficits and mitochondrial abnormalities but enhances mitochondrial and neuronal health. The present study aims to explore the impact of combined vitamin B12-folic acid supplementation on mitochondrial dynamics, neuronal health, and memory decline in old age and scopolamine-induced amnesia, which remains elusive. The results demonstrated that supplementation led to a noteworthy increase in recognition and spatial memory and expression of memory-related protein BDNF in old and amnesic mice. Moreover, the decrease in the fragmented mitochondrial number was validated by the downregulation of mitochondrial fission p-Drp1 (S616) protein and the increase in elongated mitochondria by the upregulation of mitochondrial fusion Mfn2 protein. The increased spine density and dendritic arborization in old and amnesic mice upon supplementation were confirmed by the enhanced expression level of PSD95 and synaptophysin. Furthermore, supplementation reduced ROS production, inhibited Caspase-3 activation, mitigated neurodegeneration, and enhanced mitochondrial membrane potential, ATP production, Vdac1 expression, myelination, in old and amnesic mice. Collectively, our findings imply that combined supplementation of vitamin B12-folic acid improves mitochondrial dynamics and neuronal health, and leads to recovery of memory during old age and amnesia.

Ginger Supplementation Attenuated Mitochondrial Fusion and Improved Skeletal Muscle Size in Type 2 Diabetic Rats.

BACKGROUND/AIM: Oxidative stress, regulated by SOD2 and mitochondrial dynamics, contributes to muscle atrophy in diabetes. Ginger root extract (GRE) reduces oxidative stress. However, its effect on oxidative stress, mitochondrial dynamics, and muscle atrophy is not known in the diabetic muscle. This study examined the effect of GRE on intramuscular oxidative stress, mitochondrial dynamics, and muscle size in diabetic rats. MATERIALS AND METHODS: Twenty-six male Sprague-Dawley rats were randomly divided into control diet (CON; n=10), high-fat diet with one dose of 35 mg/kg streptozotocin (HFD; n=9), and high-fat diet with one dose of 35 mg/kg streptozotocin and 0.75% w/w GRE (GRE; n=7) fed for seven weeks. Subsequently, the muscle was analyzed for cross-sectional area (CSA), H2O2 concentration, and DRP-1, MFN2, Parkin, PINK1, SOD2 mRNA. Additionally, the protein levels of SOD2, DRP-1, DRP-1ser616, LC3AB, MFN2, OPA1, Parkin, and PINK1 were analyzed. CSA, H2O2 concentration, and gene and protein expression levels were analyzed using a one-way ANOVA. Correlations among intramuscular H2O2, CSA, and SOD2 protein were assessed using Pearson's bivariate correlation test. RESULTS: In the soleus, the GRE group had a greater CSA and lower intramuscular H2O2 concentration compared to the HFD group. Compared to the HFD group, the GRE group had higher SOD2 and DRP-1 mRNA levels and lower MFN2 and total OPA1 protein levels. H2O2 concentration was negatively correlated with CSA and positively correlated with SOD2. CONCLUSION: GRE attenuated intramuscular H2O2, mitochondrial fusion, and muscle size loss. These findings suggest that GRE supplementation in diabetic rats reduces oxidative stress, which may contribute to muscle size preservation.

The impact of 60 days of -6° head down tilt bed rest on mitochondrial content, respiration and regulators of mitochondrial dynamics.

It is unclear how skeletal muscle metabolism and mitochondrial function adapt to long duration bed rest and whether changes can be prevented by nutritional intervention. The present study aimed (1) to assess the effect of prolonged bed rest on skeletal muscle mitochondrial function and dynamics and (2) to determine whether micronutrient supplementation would mitigate the adverse metabolic effect of bed rest. Participants were maintained in energy balance throughout 60 days of bed rest with micronutrient supplementation (INT) (body mass index: 23.747 ± 1.877 kg m-2 ; 34.80 ± 7.451 years; n = 10) or without (control) (body mass index: 24.087 ± 2.088 kg m-2 ; 33.50 ± 8.541 years; n = 10). Indirect calorimetry and dual-energy x-ray absorptiometry were used for measures of energy expenditure, exercise capacity and body composition. Mitochondrial respiration was determined by high-resolution respirometry in permeabilized muscle fibre bundles from vastus lateralis biopsies. Protein and mRNA analysis further examined the metabolic changes relating to regulators of mitochondrial dynamics induced by bed rest. INT was not sufficient in preserving whole body metabolic changes conducive of a decrease in body mass, fat-free mass and exercise capacity within both groups. Mitochondrial respiration, OPA1 and Drp1 protein expression decreased with bed rest, with an increase pDrp1s616 . This reduction in mitochondrial respiration was explained through an observed decrease in mitochondrial content (mtDNA:nDNA). Changes in regulators of mitochondrial dynamics indicate an increase in mitochondrial fission driven by a decrease in inner mitochondrial membrane fusion (OPA1) and increased pDrp1s616 . KEY POINTS: Sixty days of -6° head down tilt bed rest leads to significant changes in body composition, exercise capacity and whole-body substrate metabolism. Micronutrient supplementation throughout bed rest did not preserve whole body metabolic changes. Bed rest results in a decrease in skeletal muscle mitochondrial respiratory capacity, mainly as a result of an observed decrease in mitochondrial content. Prolonged bed rest ensues changes in key regulators of mitochondrial dynamics. OPA1 and Drp1 are significantly reduced, with an increase in pDrp1s616 following bed rest indicative of an increase in mitochondrial fission. Given the reduction in mitochondrial content following 60 days of bed rest, the maintenance of regulators of mitophagy in line with the increase in regulators of mitochondrial fission may act to maintain mitochondrial respiration to meet energy demands.

Pectolinarigenin Improves Oxidative Stress and Apoptosis in Mouse NSC-34 Motor Neuron Cell Lines Induced by C9-ALS-Associated Proline-Arginine Dipeptide Repeat Proteins by Enhancing Mitochondrial Fusion Mediated via the SIRT3/OPA1 Axis.

Amyotrophic lateral sclerosis (ALS) is considered a fatal progressive degeneration of motor neurons (MN) caused by oxidative stress and mitochondrial dysfunction. There are currently no treatments available. The most common inherited form of ALS is the C9orf72 mutation (C9-ALS). The proline-arginine dipeptide repeat protein (PR-DPR) produced by C9-ALS has been confirmed to be a functionally acquired pathogenic factor that can cause increased ROS, mitochondrial defects, and apoptosis in motor neurons. Pectolinarigenin (PLG) from the traditional medicinal herb Linaria vulgaris has antioxidant and anti-apoptotic properties. I established a mouse NSC-34 motor neuron cell line model expressing PR-DPR and confirmed the neuroprotective effect of PLG. The results showed that ROS production and apoptosis caused by PR-DPR could be improved by PLG treatment. In terms of mechanism research, PR-DPR inhibited the activity of the mitochondrial fusion proteins OPA1 and mitofusin 2. Conversely, the expression of fission protein fission 1 and dynamin-related protein 1 (DRP1) increased. However, PLG treatment reversed these effects. Furthermore, I found that PLG increased the expression and deacetylation of OPA1. Deacetylation of OPA1 enhances mitochondrial fusion and resistance to apoptosis. Finally, transfection with Sirt3 small interfering RNA abolished the neuroprotective effects of PLG. In summary, the mechanism by which PLG alleviates PR-DPR toxicity is mainly achieved by activating the SIRT3/OPA1 axis to regulate the balance of mitochondrial dynamics. Taken together, the potential of PLG in preclinical studies for C9-ALS drug development deserves further evaluation.

In an experimental myocardial infarction model, L-arginine pre-intervention may exert cardioprotective effects by regulating OTULIN levels and mitochondrial dynamics.

The experimental myocardial infarction (MI) model originating from isoproterenol (ISO) is frequently preferred in research due to its similarity to MI-induced damage in humans. Beneficial effects of L-arginine (L-Arg), a semi-essential amino acid, in cardiovascular diseases have been shown in many studies. This study was carried out to determine whether L-Arg pre-intervention has protective effects on heart tissue in the experimental MI model. The 28 rats used in the study were randomly divided into 4 equal groups: control, L-Arg, ISO, and L-Arg+ISO. Upon completion of all applications, cardiac markers in serum and biochemical, histopathological, and immunohistochemical examinations in cardiac tissues were performed. Cardiac markers, histopathological changes, oxidative stress, inflammation, and apoptosis were increased in the experimental MI model. In addition, administration of ISO deregulated OTULIN levels and mitochondrial dynamics in heart tissue. However, L-Arg pre-intervention showed a significant protective effect against changes in ISO-induced MI. L-Arg supplementation with cardioprotective effect may reduce the risks of possible pathophysiological processes in MI.

Blood and liver telomere length, mitochondrial DNA copy number, and hepatic gene expression of mitochondrial dynamics in mid-lactation cows supplemented with l-carnitine under systemic inflammation.

The current study was conducted to examine the effect of l-carnitine (LC) supplementation on telomere length and mitochondrial DNA copy number (mtDNAcn) per cell in mid-lactation cows challenged by lipopolysaccharide (LPS) in blood and liver. The mRNA abundance of 31 genes related to inflammation, oxidative stress, and the corresponding stress response mechanisms, the mitochondrial quality control and the protein import system, as well as the phosphatidylinositol 3-kinase/protein kinase B pathway, were assessed using microfluidics integrated fluidic circuit chips (96.96 dynamic arrays). In addition to comparing the responses in cows with or without LC, our objectives were to characterize the oxidative and inflammatory status by assessing the circulating concentration of lactoferrin (Lf), haptoglobin (Hp), fibrinogen, derivates of reactive oxygen metabolites (dROM), and arylesterase activity (AEA), and to extend the measurement of Lf and Hp to milk. Pluriparous Holstein cows were assigned to either a control group (CON, n = 26) or an LC-supplemented group (CAR; 25 g LC/cow per day; d 42 ante partum to d 126 postpartum (PP), n = 27). On d 111 PP, each cow was injected intravenously with LPS (Escherichia coli O111:B4, 0.5 µg/kg). The mRNA abundance was examined in liver biopsies of d -11 and +1 relative to LPS administration. Plasma and milk samples were frequently collected before and after the challenge. After LPS administration, circulating plasma fibrinogen and serum dROM concentrations increased, whereas AEA decreased. Moreover, serum P4 initially increased by 3 h after LPS administration and declined thereafter irrespective of grouping. The Lf concentrations increased in both groups after LPS administration, with the CAR group showing greater concentrations in serum and milk than the CON group. After LPS administration, telomere length in blood increased, whereas mtDNAcn per cell decreased; however, both remained unaffected in liver. For mitochondrial protein import genes, the hepatic mRNA abundance of the translocase of the mitochondrial inner membrane (TIM)-17B was increased in CAR cows. Moreover, TIM23 increased in both groups after LPS administration. Regarding the mRNA abundance of genes related to stress response mechanisms, 7 out of 14 genes showed group × time interactions, indicating a (local) protective effect due to the dietary LC supplementation against oxidative stress in mid-lactating dairy cows. For mtDNAcn and telomere length, the effects of the LPS-induced inflammation were more pronounced than the dietary supplementation of LC. Dietary LC supplementation affected the response to LPS primarily by altering mitochondrial dynamics. Regarding mRNA abundance of genes related to the mitochondrial protein import system, the inner mitochondrial membrane translocase (TIM complex) seemed to be more sensitive to dietary LC than the outer mitochondrial membrane translocase (TOM complex).

Dendrobine rescues cognitive dysfunction in diabetic encephalopathy by inhibiting ferroptosis via activating Nrf2/GPX4 axis.

BACKGROUND: Ferroptosis playsa crucial role in the development of dementia and dendrobine (Den)possesseshypoglycemic and neuroprotective effects. However, the character of ferroptosis in diabetic encephalopathy (DE) and Den's therapeutic effect remains unclear. PURPOSE: This study aimed to verify the effects of Den on ferroptosis in treating DE and underlying mechanisms. STUDY DESIGN: Den's therapeutic effect was assessed in db/db mice and advanced glycation end products (AGEs)-induced HT22 cells. METHODS: After oral administration with Den orMetformin for 8-week, behavioral tests were used to assess cognitive capacity. Then, biochemical analysis was preformed to detect glucose and lipid metabolism levels; histological analysis and transmission electron microscope were applied to evaluate pathological injuries. Meanwhile, EdU staining and flow cytometry were applied to test cell apoptosis. Furthermore, mitochondrial dynamics, iron transport, and Nrf2/GPX4 axis related proteins were detected by western blot or immunofluorescence. RESULTS: Our results demonstrated that Den remarkably alleviated glucose and lipid metabolism disorders, as well as ameliorated mnemonic deficits of db/db mice. Meanwhile, Den could protect AGEs-induced HT22 cells from death and apoptosis. In addition, we noted that Den inhibited lipid peroxidation by restoring mitochondrial function and reducing reactive oxygen species production. Furthermore, ferroptosis was proven to exist in db/db mice brain and Den could inhibit it via activating Nrf2/GPX4 axis. CONCLUSION: These findings indicated that Den could rescue cognitive dysfunction in DE by inhibiting ferroptosis via activating Nrf2/GPX4 axis.

[Mechanism of tonifying Qi by traditional Chinese medicine from mitochondrial dynamics].

According to the traditional Chinese medicine(TCM) theory, Qi is the essential component maintaining life. Mitochondria are the cellular organelles that generate energy. Qi exhibits abundant common characteristics in bioenergetics compared with mitochondria which control the cellular energy through fusion and fission. Studies have proven that the qi-tonifying function of Chinese medicinal plants and their components facilitates mitochondrial fusion, therefore enhancing ATP synthesis. These studies provide a framework for deciphering the pharmacological mechanisms of Qi-tonifying herbs. This article introduces the common source and function shared by Qi and mitochondria and the regulatory effects of herbal remedies on energy from mitochondria dynamics. This review aims to interpret the connotation of tonifying qi in TCM theory based on the modern biomedical theory.

The Chinese herbal medicine Fufang Zhenzhu Tiaozhi ameliorates diabetic cardiomyopathy by regulating cardiac abnormal lipid metabolism and mitochondrial dynamics in diabetic mice.

Diabetic cardiomyopathy (DCM) is an important complication leading to the death of patients with diabetes, but there is no effective strategy for clinical treatments. Fufang Zhenzhu Tiaozhi (FTZ) is a patent medicine that is a traditional Chinese medicine compound preparation with comprehensive effects for the prevention and treatment of glycolipid metabolic diseases under the guidance of "modulating liver, starting pivot and cleaning turbidity". FTZ was proposed by Professor Guo Jiao and is used for the clinical treatment of hyperlipidemia. This study was designed to explore the regulatory mechanisms of FTZ on heart lipid metabolism dysfunction and mitochondrial dynamics disorder in mice with DCM, and it provides a theoretical basis for the myocardial protective effect of FTZ in diabetes. In this study, we demonstrated that FTZ protected heart function in DCM mice and downregulated the overexpression of free fatty acids (FFAs) uptake-related proteins cluster of differentiation 36 (CD36), fatty acid binding protein 3 (FABP3) and carnitine palmitoyl transferase 1 (CPT1). Moreover, FTZ treatment showed a regulatory effect on mitochondrial dynamics by inhibiting mitochondrial fission and promoting mitochondrial fusion. We also identified in vitro that FTZ could restore lipid metabolism-related proteins, mitochondrial dynamics-related proteins and mitochondrial energy metabolism in PA-treated cardiomyocytes. Our study indicated that FTZ improves the cardiac function of diabetic mice by attenuating the increase in fasting blood glucose levels, inhibiting the decrease in body weight, alleviating disordered lipid metabolism, and restoring mitochondrial dynamics and myocardial apoptosis in diabetic mouse hearts.

Buyang Huanwu Decoction alleviates cerebral ischemic injury through modulating caveolin-1-mediated mitochondrial quality control.

Introduction: Mitochondrial quality control (MQC) is an important mechanism of neural repair after cerebral ischemia (CI). Recent studies have shown that caveolin-1 (Cav-1) is an important signaling molecule in the process of CI injury, but its mechanism of regulating MQC after CI is still unclear. Buyang Huanwu Decoction (BHD) is a classic traditional Chinese medicine formula that is often used to treat CI. Unfortunately, its mechanism of action is still obscure. Methods: In this study, we tested the hypothesis that BHD can regulate MQC through Cav-1 and exert an anti-cerebral ischemia injury effect. We used Cav-1 knockout mice and their homologous wild-type mice, replicated middle cerebral artery occlusion (MCAO) model and BHD intervention. Neurobehavioral scores and pathological detection were used to evaluate neurological function and neuron damage, transmission electron microscopy and enzymology detection of mitochondrial damage. Finally, western blot and RT-qPCR expression of MQC-related molecules were tested. Results: After CI, mice showed neurologic impairment, neuronal damage, and significant destruction of mitochondrial morphology and function, and MQC was imbalanced. Cav-1 deletion aggravated the damage to neurological function, neurons, mitochondrial morphology and mitochondrial function after CI, aggravated the imbalance of mitochondrial dynamics, and inhibited mitophagy and biosynthesis. BHD can maintain MQC homeostasis after CI through Cav-1 and improve CI injury. Discussion: Cav-1 can affect CI injury by regulating MQC, and this mechanism may be another target of BHD for anti-cerebral ischemia injury.

Pharmacological ascorbate induces sustained mitochondrial dysfunction.

Pharmacological ascorbate (P-AscH-; high dose given intravenously) generates H2O2 that is selectively cytotoxic to cancer compared to normal cells. The RAS-RAF-ERK1/2 is a major signaling pathway in cancers carrying RAS mutations and is known to be activated by H2O2. Activated ERK1/2 also phosphorylates the GTPase dynamin-related protein (Drp1), which then stimulates mitochondrial fission. Although early generation of H2O2 leads to cytotoxicity of cancer cells, we hypothesized that sustained increases in H2O2 activate ERK-Drp1 signaling, leading to an adaptive response; inhibition of this pathway would enhance the toxicity of P-AscH-. Increases in phosphorylated ERK and Drp1 induced by P-AscH- were reversed with genetic and pharmacological inhibitors of ERK and Drp1, as well as in cells lacking functional mitochondria. P-AscH- increased Drp1 colocalization to mitochondria, decreased mitochondrial volume, increased disconnected components, and decreased mitochondrial length, suggesting an increase in mitochondrial fission 48 h after treatment with P-AscH-. P-AscH- decreased clonogenic survival; this was enhanced by genetic and pharmacological inhibition of both ERK and Drp1. In murine tumor xenografts, the combination of P-AscH- and pharmacological inhibition of Drp1 increased overall survival. These results suggest that P-AscH- induces sustained changes in mitochondria, through activation of the ERK/Drp1 signaling pathway, an adaptive response. Inhibition of this pathway enhanced the toxicity P-AscH- to cancer cells.

Mitochondrial dysfunction in glaucomatous degeneration.

Glaucoma is a kind of optic neuropathy mainly manifested in the permanent death of retinal ganglion cells (RGCs), atrophy of the optic nerve, and loss of visual ability. The main risk factors for glaucoma consist of the pathological elevation of intraocular pressure (IOP) and aging. Although the mechanism of glaucoma remains an open question, a theory related to mitochondrial dysfunction has been emerging in the last decade. Reactive oxygen species (ROS) from the mitochondrial respiratory chain are abnormally produced as a result of mitochondrial dysfunction. Oxidative stress takes place when the cellular antioxidant system fails to remove excessive ROS promptly. Meanwhile, more and more studies show that there are other common features of mitochondrial dysfunction in glaucoma, including damage of mitochondrial DNA (mtDNA), defective mitochondrial quality control, ATP reduction, and other cellular changes, which are worth summarizing and further exploring. The purpose of this review is to explore mitochondrial dysfunction in the mechanism of glaucomatous optic neuropathy. Based on the mechanism, the existing therapeutic options are summarized, including medications, gene therapy, and red-light therapy, which are promising to provide feasible neuroprotective ideas for the treatment of glaucoma.

Buyang huanwu decoction inhibits diabetes-accelerated atherosclerosis via reduction of AMPK-Drp1-mitochondrial fission axis.

ETHNOPHARMACOLOGICAL RELEVANCE: Traditional Chinese drugs, including Buyang Huanwu decoction (BYHWD), have been used in traditional practice to manage cardiovascular and cerebrovascular diseases. However, the effect and mechanisms by which this decoction alleviates diabetes-accelerated atherosclerosis are unknown and require exploration. AIM OF THE STUDY: This study aims to investigate the pharmacological effects of BYHWD on preventing diabetes-accelerated atherosclerosis, and elucidate its underlying mechanism. MATERIALS AND METHODS: Streptozotocin (STZ)-induced diabetic ApoE-/- mice were treated with BYHWD. Atherosclerotic aortic lesions, endothelial function, mitochondrial morphology, and mitochondrial dynamics-related proteins were evaluated in isolated aortas. High glucose-exposed human umbilical endothelial cells (HUVECs) were treated with BYHWD and its components. AMPK siRNA transfection, Drp1 molecular docking, Drp1 enzyme activity measurement, and so on were used to explore and verify the mechanism. RESULT: BYHWD treatment inhibited the worsening of diabetes-accelerated atherosclerosis by lessening atherosclerotic lesions in diabetic ApoE-/- mice, by impeding endothelial dysfunction under diabetic conditions, and by inhibiting mitochondrial fragmentation by lowering protein expression levels of Drp1 and mitochondrial fission-1 protein (Fis1) in diabetic aortic endothelium. In high glucose-exposed HUVECs, BYHWD treatment also downgraded reactive oxygen species, promoted nitric oxide levels, and abated mitochondrial fission by reducing protein expression levels of Drp1 and fis1, but not mitofusin-1 and optic atrophy-1. Interestingly, we found that BYHWD's protective effect against mitochondrial fission is mediated by AMPK activation-dependent reduction of Drp1 levels. The main serum chemical components of BYHWD, ferulic acid, and calycosin-7-glucoside, can reduce the expression of Drp1 by regulating AMPK, and can inhibit the activity of GTPase of Drp1. CONCLUSION: The above findings support the conclusion that BYHWD suppresses diabetes-accelerated atherosclerosis by reducing mitochondrial fission through modulation of the AMPK/Drp1 pathway.

QiShenYiQi dripping pill alleviates myocardial ischemia-induced ferroptosis via improving mitochondrial dynamical homeostasis and biogenesis.

ETHNOPHARMACOLOGICAL RELEVANCE: QiShenYiQi is a Chinese herbal formula composed of Astragalus membranaceus Fisch. ex Bunge, root; Slauia miltiorrhiza Bunge, root and rhizome; Panax notoginseng (Burkill) F.H.Chen, root; and Dalbergia odorifera T.C.Chen, heartwood of trunk and root with a proportion of 10:5:1:0.067. Its dripping pills were approved by the National Medical Products Administration (NMPA) in 2003 and could be used in the clinical treatment of ischemic heart diseases. Ferroptosis is an important pathological mechanism in the process of myocardial ischemia (MI). Whether QSYQ can improve ferroptosis induced by myocardial ischemia is still unclear. AIM OF THE STUDY: In this study, the potential mechanisms of QSYQ against ferroptosis in MI-induced injury were investigated. MATERIALS AND METHODS: The main components of QSYQ were analyzed by HPLC-Q-TOF-MS/MS. MI model was established by ligation of the left anterior descending coronary artery and then treated with QSYQ dropping pills for 14 days. The cardiac function of mice was evaluated by echocardiography. Hematoxylin and eosin (H&E) staining and Masson's trichrome staining were used to detect the pathological changes in heart tissue. Serum biochemical indexes were analyzed by biochemical kit. Transmission electron microscope (TEM) was used to observe the mitochondria ultrastructure and mitochondrial ROS was detected by immunofluorescence. Then, photoacoustic imaging was used to observe the redox status of the mice' hearts. Finally, the mitochondrial dynamics and biogenesis related proteins and the proteins of ferroptosis were analyzed by western blotting. RT-PCR was used to detect the mRNA expression changes of ferroptosis. RESULTS: A total of 20 principal components of QSYQ were characterized by HPLC-Q-TOF-MS/MS. QSYQ significantly improved cardiac function and myocardial injury in MI mice. Furthermore, the lipid peroxidation change levels (MDA, 4-HNE, and GSH) in serum were attenuated and myocardial iron content was reduced after QSYQ treatment. On this basis, QSYQ also improved the expression changes of ferroptosis related mRNA and proteins. In addition, QSYQ promoted mitochondrial biogenesis (PGC-1α, Nrf1, and TFAM) and mitochondrial fusion (MFN-2 and OPA1) and inhibited mitochondrial excessive fission (Phosphorylation of Drp1 at ser616) in vitro and in vivo, indicating that the cardioprotection of QSYQ might be related to promoting mitochondrial biogenesis and dynamic homeostasis. CONCLUSION: In summary, QSYQ could alleviate MI-induced ferroptosis by improving mitochondrial biogenesis and dynamic homeostasis.

Asiatic acid attenuates tubular injury in diabetic kidney disease by regulating mitochondrial dynamics via the Nrf-2 pathway.

BACKGROUND: Mitochondrial dynamics plays a crucial role in tubular injury in diabetic kidney disease (DKD). Asiatic acid (AA) has demonstrated renal protective effects in DKD; however, its therapeutic effect on tubular injury in DKD remains unclear. PURPOSE: This study aimed to verify the effects of AA on tubular injury in DKD and underlying mechanisms. STUDY DESIGN: In the present study, the effects of AA on tubular injury were assessed in rats with streptozotocin-induced diabetes and advanced glycation end products (AGEs)-stimulated HK-2 cells models. METHODS: After oral administration with or without AA for ten weeks, body weight and levels of fast blood glucose, serum creatinine (sCr), blood urea nitrogen (BUN), urinary albumin, and kidney injury molecule-1 (KIM-1) were detected. Histological analysis was performed to evaluate the renal function of rats. Moreover, the expression of proteins associated with the Nrf-2 pathway and mitochondrial dynamics was analyzed. AGEs-stimulated HK-2 cells were examined to evaluate the tubular protection and the mechanism of AA in vitro. RESULTS: AA remarkably decreased albumin levels, KIM-1 levels in urine, and serum Cr, and BUN levels. In addition, AA prevented tubular injury and mitochondrial injury by regulating the Nrf-2 pathway and mitochondrial dynamics. Furthermore, the effects of AA on mitochondrial dynamics and tubular protection were eliminated after treatment with ML385 (Nrf2 inhibitor). CONCLUSION: These findings suggested that AA might be developed as a potential candidate for the treatment of tubular injury in DKD, and its effects are potentially mediated via the regulation of the Nrf-2 pathway and mitochondrial dynamics.