Pathological Roles of Mitochondrial Oxidative Stress and Mitochondrial Dynamics in Cardiac Microvascular Ischemia/Reperfusion Injury

Effect of modified citrus pectin on galectin-3 inhibition in cisplatin-induced cardiac and renal toxicity

This study evaluated the effect of pharmacological inhibition of galectin 3 (Gal-3) with modified citrus pectin (MCP) on the heart and kidney in a model of cisplatin-induced acute toxicity. Male Wistar rats were divided into four groups (n = 6/group): SHAM, which received sterile saline intraperitoneally (i.p.) for three days; CIS, which received cisplatin i.p. (10 mg/kg/day) for three days; MCP, which received MCP orally (100 mg/kg/day) for seven days, followed by sterile saline i.p. for three days; MCP+CIS, which received MCP orally for seven days followed by cisplatin i.p. for three days. The blood, heart, and kidneys were collected six hours after the last treatment. MCP treatment did not change Gal-3 protein levels in the blood and heart, but it did reduce them in the kidneys of the MCP groups compared to the SHAM group. While no morphological changes were evident in the cardiac tissue, increased malondialdehyde (MDA) levels and deregulation of the mitochondrial oxidative phosphorylation system were observed in the heart homogenates of the MCP+CIS group. Cisplatin administration caused acute tubular degeneration in the kidneys; the MCP+CIS group also showed increased MDA levels. In conclusion, MCP therapy in the acute model of cisplatin-induced toxicity increases oxidative stress in cardiac and renal tissues. Further investigations are needed to determine the beneficial and harmful roles of Gal-3 in the cardiorenal system since it can act differently in acute and chronic diseases/conditions.

The Neuroprotective Effects of Curcumin Nanoparticles on The Cerebral Ischemia-Reperfusion Injury in The Rats-The Roles of The Protein Kinase RNA-Like ER Kinase/Extracellular Signal-Regulated Kinase and Transcription Factor EB proteins

OBJECTIVE

Reduction of cerebral ischemia-reperfusion injury (IRI)/re-oxygenation injury, is defined as the paradoxical exacerbation of the cellular dysfunction and death, following restoration of the blood flow to previously ischemic tissues. The re-establishment of blood flow is essential to salvage the ischemic tissues. As a result, the treatment of IRI with novel therapies, which have fewer side effects, are of great importance. Therefore, this study aimed to investigate the effects of curcumin nanoparticle (CN) pre-treatment on the cerebral I/R rat model.

MATERIALS AND METHODS

In this experimental study, CN was administered to rats orally five days before the bilateral common carotid artery occlusion (BCCAO) and continued for three days. The intensity of oxidative stress, the activities of antioxidant enzymes, glutathione (GSH) content, the activity of mitochondrial enzymes, including succinate dehydrogenase (SDH), malate dehydrogenase (MDH) and lactate dehydrogenase (LDH), curcumin bioavailability, pERK/ERK expression ratio and TFEB protein were studied. Data analysis was performed using Graphpad Prism V.8 software, one-way analysis of variance (ANOVA) with the statistical package for the social sciences (SPSS V.26 software).

RESULTS

Cerebral IRI-damage significantly increased the oxidative stress (P=0.0008) and decreased the activity of the antioxidant enzymes including catalase (CAT) (P<0.001), super oxide dismutase (SOD) (P<0.001), reduced GSH (P<0.001), mitochondrial enzymes, pERK/ERK expression ratio (P=0.002) and TEFB protein (P=0.005) in rats' brains. In addition, the pre-treatment of the rats with CN resulted in a decrease in the reactive oxygen species (ROS), and an increase in the activities of antioxidants and mitochondrial enzymes. This in turn up-regulated the pERK/ERK expression ratio and TEFB expression.

CONCLUSION

CN has neuroprotective effects on the cerebral IRI condition due to its antioxidant properties and is able to overexpress the pERK and TFEB proteins; thus, it can be considered as a suitable treatment option during and after the incidence of stroke.

Luteolin Pretreatment Ameliorates Myocardial Ischemia/Reperfusion Injury by lncRNA-JPX/miR-146b Axis

Background

In the present study, we aimed to find out whether luteolin (Lut) pretreatment could ameliorate myocardial ischemia/reperfusion (I/R) injury by regulating the lncRNA just proximal to XIST (JPX)/microRNA-146b (miR-146b) axis.

Methods

We established the models in vitro (HL-1 cells) and in vivo (C57BL/6J mice) to certify the protection mechanism of Lut pretreatment on myocardial I/R injury. Dual luciferase reporter gene assay was utilized for validating that JPX could bind to miR-146b. JPX and miR-146b expression levels were determined by RT-qPCR. Western blot was utilized to examine apoptosis-related protein expression levels, including cleaved caspase-9, caspase-9, cleaved caspase-3, caspase-3, Bcl-2, Bax, and BAG-1. Apoptosis was analyzed by Annexin V-APC/7-AAD dualstaining, Hoechst 33342 staining, as well as flow cytometry. Animal echocardiography was used to measure cardiac function (ejection fraction (EF) and fractional shortening (FS) indicators).

Results

miR-146b was demonstrated to bind and recognize the JPX sequence site by dual luciferase reporter gene assay. The expression level of miR-146b was corroborated to be enhanced by H/R using RT-qPCR (P < 0.001 vs. Con). Moreover, JPX could reduce the expression of miR-146b, whereas inhibiting JPX could reverse the alteration (P < 0.001 vs. H/R, respectively). Western blot analysis demonstrated that Lut pretreatment increased BAG-1 expression level and Bcl-2/Bax ratio, but diminished the ratio of cleaved caspase 9/caspase 9 and cleaved caspase 3/caspase 3 (P < 0.001 vs. H/R, respectively). Moreover, the cell apoptosis change trend, measured by Annexin V-APC/7-AAD dualstaining, Hoechst 33342 staining, along with flow cytometry, was consistent with that of apoptosis-related proteins. Furthermore, pretreatment with Lut improved cardiac function (EF and FS) (P < 0.001 vs. I/R, respectively), as indicated in animal echocardiography.

Conclusion

Our results demonstrated that in vitro and in vivo, Lut pretreatment inhibited apoptosis via the JPX/miR-146b axis, ultimately improving myocardial I/R injury.

Involvement of mitochondrial dynamics and mitophagy in diabetic endothelial dysfunction and cardiac microvascular injury

Endothelial cells (ECs), found in the innermost layer of blood vessels, are crucial for maintaining the structure and function of coronary microcirculation. Dysregulated coronary microcirculation poses a fundamental challenge in diabetes-related myocardial microvascular injury, impacting myocardial blood perfusion, thrombogenesis, and inflammation. Extensive research aims to understand the mechanistic connection and functional relationship between cardiac EC dysfunction and the development, diagnosis, and treatment of diabetes-related myocardial microvascular injury. Despite the low mitochondrial content in ECs, mitochondria act as sensors of environmental and cellular stress, influencing EC viability, structure, and function. Mitochondrial dynamics and mitophagy play a vital role in orchestrating mitochondrial responses to various stressors by regulating morphology, localization, and degradation. Impaired mitochondrial dynamics or reduced mitophagy is associated with EC dysfunction, serving as a potential molecular basis and promising therapeutic target for diabetes-related myocardial microvascular injury. This review introduces newly recognized mechanisms of damaged coronary microvasculature in diabetes-related microvascular injury and provides updated insights into the molecular aspects of mitochondrial dynamics and mitophagy. Additionally, novel targeted therapeutic approaches against diabetes-related microvascular injury or endothelial dysfunction, focusing on mitochondrial fission and mitophagy in endothelial cells, are summarized.

Tongguan capsule for treating myocardial ischemia-reperfusion injury: integrating network pharmacology and mechanism study

CONTEXT

Although Tongguan capsule (TGC) is used in the treatment of coronary atherosclerotic disease, the exact mechanism remains unclear.

OBJECTIVE

Network pharmacology and experimental validation were applied to examine the mechanism of TGC for treating myocardial ischemia-reperfusion injury (MIRI).

MATERIALS AND METHODS

The components and candidate targets were searched based on various databases such as TCMSP, TCMID, BATMAN-TCM. The binding ability was determined by molecular docking. The ischemia-reperfusion (I/R) model was constructed by ligating the left anterior descending (LAD) coronary artery. APOE^-/- mice were divided into three groups (n = 6): Sham group, I/R group, and TGC group (1 g/kg/d). To further verification, HCAEC cells were subjected to hypoxia-reoxygenation (H/R) to establish in vitro model.

RESULTS

The compounds, such as quercetin, luteolin, tanshinone IIA, kaempferol and bifendate, were obtained after screening. The affinity values of the components with GSK-3β, mTOR, Beclin-1, and LC3 were all <-5 kcal/mol. In vivo, TGC improved LVEF and FS, reducing infarct size. In vitro, Hoechst 33258 staining result showed TGC inhibited apoptosis. Compare with the H/R model, TGC treatment increased the levels of GSK-3β, LC3, and Beclin1, while decreasing the expression of mTOR and p62 (p < 0.05).

DISCUSSION AND CONCLUSION

The findings revealed that TGC exerted a cardioprotective effect by up regulating autophagy-related proteins through the mTOR pathway, which may be a therapeutic option for MIRI. However, there are still some limitations in this research. It is necessary to search more databases to obtain information and further demonstrated through randomized controlled trials for generalization.

Myocardial ischemia-reperfusion injury; Molecular mechanisms and prevention

Cardiovascular diseases are one of the leading causes of mortality in developed countries. Among cardiovascular disorders, myocardial infarction remains a life-threatening problem predisposing to the development and progression of ischemic heart failure. Ischemia/reperfusion (I/R) injury is a critical cause of myocardial injury. In recent decades, many efforts have been made to find the molecular and cellular mechanisms underlying the development of myocardial I/R injury and post-ischemic remodeling. Some of these mechanisms are mitochondrial dysfunction, metabolic alterations, inflammation, high production of ROS, and autophagy deregulation. Despite continuous efforts, myocardial I/R injury remains a major challenge in medical treatments of thrombolytic therapy, heart disease, primary percutaneous coronary intervention, and coronary arterial bypass grafting. The development of effective therapeutic strategies to reduce or prevent myocardial I/R injury is of great clinical significance.

Mitophagy as a mitochondrial quality control mechanism in myocardial ischemic stress: from bench to bedside

Myocardial ischemia reduces the supply of oxygen and nutrients to cardiomyocytes, leading to an energetic crisis or cell death. Mitochondrial dysfunction is a decisive contributor to the reception, transmission, and modification of cardiac ischemic signals. Cells with damaged mitochondria exhibit impaired mitochondrial metabolism and increased vulnerability to death stimuli due to disrupted mitochondrial respiration, reactive oxygen species overproduction, mitochondrial calcium overload, and mitochondrial genomic damage. Various intracellular and extracellular stress signaling pathways converge on mitochondria, so dysfunctional mitochondria tend to convert from energetic hubs to apoptotic centers. To interrupt the stress signal transduction resulting from lethal mitochondrial damage, cells can activate mitophagy (mitochondria-specific autophagy), which selectively eliminates dysfunctional mitochondria to preserve mitochondrial quality control. Different pharmacological and non-pharmacological strategies have been designed to augment the protective properties of mitophagy and have been validated in basic animal experiments and pre-clinical human trials. In this review, we describe the process of mitophagy in cardiomyocytes under ischemic stress, along with its regulatory mechanisms and downstream effects. Then, we discuss promising therapeutic approaches to preserve mitochondrial homeostasis and protect the myocardium against ischemic damage by inducing mitophagy.

Protective effects of Shen Yuan Dan on myocardial ischemia-reperfusion injury via the regulation of mitochondrial quality control

Background

Myocardial cell death resulting from ischemia-reperfusion (I/R) injury has been a predominant contributor to morbidity and mortality globally. The mitochondria-centered mechanism plays an important role in the formation of I/R injury. This study intended to discuss the protective mechanism of Shen Yuan Dan (SYD) on cardiomyocytes hypoxia-reoxygenation (H/R) injury via the regulation of mitochondrial quality control (MQC). Additionally, this study clarified the mechanism by which SYD suppressed mitophagy activity through the suppression of the PTEN-induced kinase 1 (PINK1)/Parkin pathway.

Methods

To induce cellular injury, H9c2 cardiomyocytes were exposed to H/R stimulation. Following the pretreatment with SYD, cardiomyocytes were subjected to H/R stimulation. Mitochondrial membrane potential (MMP), adenosine triphosphate (ATP), superoxide dismutase (SOD), and methane dicarboxylic aldehyde (MDA) were detected to evaluate the degree of cardiomyocyte mitochondrial damage. Laser confocal microscopy was applied to observe the mitochondrial quality, and the messenger (mRNA) levels of mitofusin 1 (Mfn1), mitofusin 2 (Mfn2), optic atrophy protein 1 (Opa1), dynamin-related protein 1 (Drp1), fission 1 (Fis1), and peroxisome proliferator-activated receptor gamma coactivator-1α (PGC-1α) in cardiomyocytes were assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Western blotting was employed for the estimation of light chain 3 (LC3)-I, LC3-II, PINK1, and Parkin in cardiomyocytes.

Results

It was discovered that SYD pretreatment elevated MMP in H/R injury cardiomyocytes, enhanced ATP content, activated SOD activity, and reduced MDA level. SYD treatment increased the mRNA levels of Mfn1, Mfn2, Opa1 and PGC-1α decreased the mRNA levels of Drp1 and Fis1, and reduced the protein levels of LC3, PINK1, and Parkin.

Conclusions

SYD plays a protective role in H/R injury to cardiomyocytes by regulating mitochondrial quality. Meanwhile, SYD may inhibit mitophagy activity through inhibiting the PINK1/Parkin pathway. This study provides insights into the underlying mechanism of SYD in alleviating myocardial I/R injury.

Tingli Dazao Decoction pretreatment ameliorates mitochondrial damage induced by oxidative stress in cardiomyocytes

ETHNOPHARMACOLOGICAL RELEVANCE

Tingli Dazao Decoction (TLDZD) recorded in "Synopsis of Prescriptions of the Golden Chamber" is a classical prescription used for the treatment of heart failure nowadays. The studies of TLDZD were mainly focused on clinical practice where the formula was usually combined with other medicinal herbs. Chemical composition and cardiovascular pharmacological research of TLDZD were still insufficient.

AIM OF THE STUDY

This study aimed to investigate the chemical constituents of TLDZD, evaluate the effects of TLDZD on mitochondria of myocardial cells under oxidative stress, and identify its potential cardioprotective components.

MATERIALS AND METHODS

Chemical composition analysis of TLDZD was performed by ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry. An in vitro oxidative stress model of cardiomyocytes was established by treating H9c2 cells with tert-butyl hydroperoxide (tBHP). The impact of TLDZD and its components on the production of cellular reactive oxygen species (ROS) and mitochondrial ROS (mROS), the level of malonaldehyde as well as the structure and function of mitochondria were evaluated. The effect of TLDZD on AKT/Nrf2/HO-1 signaling pathway in cardiomyocytes under oxidative stress were observed.

RESULTS

Seventy-eight compounds were characterized from TLDZD, among which flavonoids, glucosinolates and phenylpropanoids were abundant, and a small number of cardiac glycosides and alkaloids also existed in TLDZD. Pretreatment with TLDZD significantly attenuated cell death, accompanied by decreased ROS and mROS production, reduced malonaldehyde level, lower mitochondrial membrane potential and adenosine triphosphate content in H9c2 cells stimulated with tBHP. The active components were mainly flavonoids of TLZ represented by quercetin-3-O-β-D-glucose-7-O-β-D-gentiobioside. In mechanism, the cardioprotective effect of TLDZD was proved to be associated with the activation of the AKT/Nrf2/HO-1 signaling pathway.

CONCLUSIONS

The chemical profile of TLDZD was comprehensively investigated. Flavonoids with quercetin-3-O-β-D-glucose-7-O-β-D-gentiobioside as the representative, were the main component in TLDZD responsible for attenuating mitochondrial oxidative damage in cardiomyocytes.

Shenlian extract decreases mitochondrial autophagy to regulate mitochondrial function in microvascular to alleviate coronary artery no-reflow

Shenlian (SL) extract has been proven to be effective in the prevention and treatment of atherosclerosis and myocardial ischemia. However, the function and molecular mechanisms of SL on coronary artery no-reflow have not been fully elucidated. This study was designed to investigate the contribution of SL extract in repressing excessive mitochondrial autophagy to protect the mitochondrial function and prevent coronary artery no-reflow. The improvement of SL on coronary artery no-reflow was observed in vivo experiments and the molecular mechanisms were further explored through vitro experiments. First, a coronary artery no-reflow rat model was built by ligating the left anterior descending coronary artery for 2 hr of ischemia, followed by 24 hr of reperfusion. Thioflavin S (6%, 1 ml/kg) was injected into the inferior vena cava to mark the no-reflow area. Transmission electron microscopy was performed to observe the cellular structure, mitochondrial structure, and mitochondrial autophagy of the endothelial cells. Immunofluorescence was used to observe the microvascular barrier function and microvascular inflammation. Cardiac microvascular endothelial cells (CMECs) were isolated from rats. The CMECs were deprived of oxygen-glucose deprivation (OGD) for 2 hr and reoxygenated for 4 hr to mimic the Myocardial ischemia-reperfusion (MI/R) injury-induced coronary artery no-reflow in vitro. Mitochondrial membrane potential was assessed using JC-1 dye. Intracellular adenosine triphosphate (ATP) levels were determined using an ATP assay kit. The cell total reactive oxygen species (ROS) levels and cell apoptosis rate were analyzed by flow cytometry. Colocalization of mitochondria and lysosomes indirectly indicated mitophagy. The representative ultrastructural morphologies of the autophagosomes and autolysosomes were also observed under transmission electron microscopy. The mitochondrial autophagy-related proteins (LC3II/I, P62, PINK, and Parkin) were analyzed using Western blot analysis. In vivo, results showed that, compared with the model group, SL could reduce the no-reflow area from 37.04 ± 9.67% to 18.31 ± 4.01% (1.08 g·kg^-1 SL), 13.79 ± 4.77% (2.16 g·kg^-1 SL), and 12.67 ± 2.47% (4.32 g·kg^-1 SL). The extract also significantly increased the left ventricular ejection fraction (EF) and left ventricular fractional shortening (FS) (p < 0.05 or p < 0.01). The fluorescence intensities of VE-cadherin, which is a junctional protein that preserves the microvascular barrier function, decreased to ~74.05% of the baseline levels in the no-reflow rats and increased to 89.87%(1.08 g·kg^-1 SL), 82.23% (2.16 g·kg^-1 SL), and 89.69% (4.32 g·kg^-1 SL) of the baseline levels by SL treatment. SL administration repressed the neutrophil migration into the myocardium. The oxygen-glucose deprivation/reoxygenation (OGD/R) model was induced in vitro to mimic microvascular ischemia-reperfusion injury. The impaired mitochondrial function after OGD/R injury led to decreased ATP production, calcium overload, the excessive opening of the Mitochondrial Permeability Transition Pore, decreased mitochondrial membrane potential, and reduced ROS scavenging ability (p < 0.05 or p < 0.01). The normal autophagosomes (double-membrane vacuoles with autophagic content) in the sham group were rarely found. The large morphology and autophagosomes were frequently observed in the model group. By contrast, SL inhibited the excessive activation of mitochondrial autophagy. The mitochondrial autophagy regulated by the PINK/Parkin pathway was excessively activated. However, administration of SL prevented the activation of the PINK/Parkin pathway and inhibited excessive mitochondrial autophagy to regulate mitochondrial dysfunction. Results also demonstrated that mitochondrial dysfunction stimulated endothelial cell barrier dysfunction, but Evans blue transmission was significantly decreased and transmembrane resistance was increased significantly by SL treatment (p < 0.05 or p < 0.01). Carbonylcyanide-3-chlorophenylhydrazone (CCCP) could activate the PINK/Parkin pathway. CCCP reversed the regulation of SL on mitochondrial autophagy and mitochondrial function. SL could alleviate coronary artery no-reflow by protecting the microvasculature by regulating mitochondrial function. The underlying mechanism was related to decreased mitochondrial autophagy by the PINK/Parkin pathway.

Heart failure with preserved ejection fraction: the role of microvascular dysfunction

Aim. To evaluate the relationship between coronary microvascular dysfunction (CMD), biomarkers of cardiac fibrosis and cardiac remodeling (soluble ST2 (sST2), fibroblast growth factor-23 (FGF-23), matrix metalloproteinase-9 (MMP-9), tissue inhibitor of metalloproteinase-1 (TIMP-1), and NT-proBNP), parameters of diastolic dysfunction (DD), and the presence of heart failure with preserved ejection fraction (HFpEF) in symptomatic patients.

Materials and methods. Study participants were 59 patients with non-obstructive coronary artery disease (CAD) and preserved left ventricular ejection fraction (LVEF) of 62 (56; 67) %. Non-obstructive CAD was verified by coronary computed tomography angiography. Stress-and rest-myocardial blood flow (MBF) and coronary flow reserve (CFR) parameters were evaluated by CZT SPECT. Serum levels of cardiac biomarkers were measured by the enzyme immunoassay. Two-dimensional transthoracic echocardiography was used to assess DD parameters.

Results. Decreased CFR was defined as CFR ≤ 2. Therefore, CMD was defined as the presence of decreased CFR in the absence of flow-limiting CAD. Distribution of patients was performed by CFR values: group 1 included patients with preserved CFR (>2, n = 35), and group 2 encompassed patients with decreased CFR (≤2, n = 24). In 87.5% of cases, patients with CMD were diagnosed with HFpEF, whereas in patients with preserved CFR, heart failure was diagnosed only in 51.4% of cases (p < 0.0001). CFR values were correlated with the left atrial volume (r = –0.527; p = 0.001), E / A ratio (r = –0.321, p = 0.012), and E / e’ (r = –0.307; p = 0.021). Following the ROC analysis, the levels of sST2 ≥ 31.304 ng / ml (AUС = 0.730; р = 0.004) and NT-proBNP ≥ 0.034 pg / ml (AUС = 0.815; р = 0.034) were identified as cut-off values for the presence of CMD in patients with non-obstructive CAD.

Conclusion. The obtained data suggest that CMD may play an essential role in HFpEF. The values of CFR were correlated with DD parameters, and decreased CFR was associated with overexpression of biomarkers of cardiac fibrosis and cardiac remodeling. Serum levels of sST2 and NT-proBNP were identified as cut-off values for the presence of CMD in patients with non-obstructive CAD.

Nuanxinkang prevents the development of myocardial infarction-induced chronic heart failure by promoting PINK1/Parkin-mediated mitophagy

BACKGROUND

Mitochondrial dysfunction is an important pathological feature of chronic heart failure (CHF). Regulation of mitophagy can effectively maintain mitochondrial homeostasis and energy metabolism, thereby inhibiting the development of CHF. Nuanxinkang (NXK), a Chinese herbal compound preparation, has significant cardioprotective effects on CHF; however, its underlying mechanism on mitophagy has not been completely clarified. This research intended to investigate the mechanism of NXK in treating myocardial infarction (MI)-induced CHF.

METHODS

The left anterior descending coronary artery (LAD) ligation surgery was performed to establish an MI-induced CHF model in male C57BL/6 mice. From 1 day after surgery, mice were given NXK (0.41, 0.82 or 1.65 g/kg/d), Perindopril (PDPL, 0.607 mg/kg/d), or an equivalent amount of sterile water by gavage for 28 continuous days. Then, mice were examined for cardiac function, myocardial fibrosis, cardiomyocyte apoptosis, mitochondrial structure and mitophagy levels of cardiomyocytes, etc. In addition, a hypoxic injury model was created using HL-1 cardiomyocytes from wild-type (WT) mice. HL-1 cells were pretreated with or without NXK-containing serum. Mitochondrial function and mitophagy levels were examined in HL-1 cells.

RESULTS

In MI-induced CHF mice, cardiac dysfunction, severe cardiac remodeling, elevated levels of oxidative stress, reduced ATP levels, and inhibition of PINK1/Parkin-mediated mitophagy were observed. High-dose NXK treatment (1.65 g/kg/d) significantly improved myocardial energy metabolism, inhibited cardiac remodeling, improved cardiac function, and restored cardiac PINK1/Parkin-mediated mitophagy levels to some extent in MI mice. In vitro, elevated levels of mitochondrial reactive oxygen species (ROS) with impaired mitochondrial membrane potential (ΔΨm) were observed in hypoxic HL-1 cells. While NXK treatment significantly protected cardiomyocytes from hypoxia-induced mitochondrial dysfunction, which is consistent with the in vivo results. Further studies showed that NXK could increase PINK1/Parkin-mediated mitophagy levels in cardiomyocytes, which could be blocked by the mitophagy inhibitor Mdivi-1.

CONCLUSION

In conclusion, NXK could prevent cardiac mitochondrial dysfunction and improve cardiac function against MI-induced CHF by promoting Pink1/Parkin-mediated mitophagy, which represents a very prospective strategy for the treatment of CHF.

Research Progress of Chinese Medicine in the Treatment of Myocardial Ischemia-Reperfusion Injury

Vascular recanalization is the essential procedure in which severe coronary artery stenosis is diagnosed. However, the blood flow recovery associated with this procedure may cause myocardial ischemia-reperfusion injury (MIRI), which aggravates heart failure. Unfortunately, the mechanism of MIRI has historically been poorly understood. As we now know, calcium overloading, oxidative stress, mitochondrial dysfunction, inflammatory responses, and ferroptosis take part in the process of MIRI. Modern medicine has shown through clinical studies its own limited effects in the case of MIRI, whereas Chinese traditional medicine demonstrates a strong vitality. Multiple-target effects, such as anti-inflammatory, anti-oxidant, and cardio-protection effects, are central to this vitality. In our clinic center, Yixin formula is commonly used in patients with MIRI. This formula contains Astragalus, Ligusticum Wallichii, Salvia, Rhodiola Rosea, Radix Angelicae Sinensis, Cyperus Rotundus, and Cassia Twig. Its effects include warming yang energy, activating blood circulation, and eliminating blood stasis. In our previous laboratory studies, we have proved that it can reduce MIRI and oxidative stress injury in rats suffering from ischemia myocardiopathy. It can also inhibit apoptosis and protect myocardium. In this paper, we review the research of Yixin formula and other related herbal medicines in MIRI therapy.

Pathological Roles of Oxidative Stress in Cardiac Microvascular Injury

Cardiac microvascular injury can be a fundamental pathological process that causes high incidence cardiovascular diseases such heart failure, diabetic cardiomyopathy, and hypertension. It is also an independent risk factor for cardiovascular disease. Oxidative stress is a significant pathological process in which the body interferes with the balance of the endogenous antioxidant defense system by producing reactive oxygen species, leading to property changes and dysfunction. It has been demonstrated that oxidative stress is one of the major causes of cardiac microvascular disease. Therefore, additional investigation into the relationship between oxidative stress and cardiac microvascular injury will direct clinical management in the future. In order to give suggestions and support for future in-depth studies, we give a basic overview of the cardiac microvasculature in relation to physiopathology in this review. We also summarize the role of oxidative stress of mitochondrial and non-mitochondrial origin in cardiac microvascular injury and related drug studies.

Dynamic Metabolic Changes During Prolonged Ex Situ Heart Perfusion Are Associated With Myocardial Functional Decline

Ex situ heart perfusion (ESHP) was developed to preserve and evaluate donated hearts in a perfused beating state. However, myocardial function declines during ESHP, which limits the duration of perfusion and the potential to expand the donor pool. In this research, we combine a novel, minimally-invasive sampling approach with comparative global metabolite profiling to evaluate changes in the metabolomic patterns associated with declines in myocardial function during ESHP. Biocompatible solid-phase microextraction (SPME) microprobes serving as chemical biopsy were used to sample heart tissue and perfusate in a translational porcine ESHP model and a small cohort of clinical cases. In addition, six core-needle biopsies of the left ventricular wall were collected to compare the performance of our SPME sampling method against that of traditional tissue-collection. Our state-of-the-art metabolomics platform allowed us to identify a large number of significantly altered metabolites and lipid species that presented comparable profile of alterations to conventional biopsies. However, significant discrepancies in the pool of identified analytes using two sampling methods (SPME vs. biopsy) were also identified concerning mainly compounds susceptible to dynamic biotransformation and most likely being a result of low-invasive nature of SPME. Overall, our results revealed striking metabolic alterations during prolonged 8h-ESHP associated with uncontrolled inflammation not counterbalanced by resolution, endothelial injury, accelerated mitochondrial oxidative stress, the disruption of mitochondrial bioenergetics, and the accumulation of harmful lipid species. In conclusion, the combination of perfusion parameters and metabolomics can uncover various mechanisms of organ injury and recovery, which can help differentiate between donor hearts that are transplantable from those that should be discarded.

Protection Against Post-resuscitation Acute Kidney Injury by N-Acetylcysteine via Activation of the Nrf2/HO-1 Pathway

Background and Objective

Acute kidney injury (AKI), the common complication after cardiopulmonary resuscitation (CPR), seriously affects the prognosis of cardiac arrest (CA) patients. However, there are limited studies on post-resuscitation AKI. In addition, it has been demonstrated that N-acetylcysteine (N-AC) as an ROS scavenger, has multiorgan-protective effects on systemic and regional ischaemia-reperfusion injuries. However, no studies have reported its protective effects against post-resuscitation AKI and potential mechanisms. This study aimed to clarify the protective effects of N-AC on post-resuscitation AKI and investigate whether its potential mechanism was mediated by activating Nrf-2/HO-1 pathway in the kidney.

Methods

We established cardiac arrest models in rats. All animals were divided into four groups: the sham, control, N-AC, and ZnPP groups. Animals in each group except for the ZnPP group were assigned into two subgroups based on the survival time: 6 and 48 h. The rats in the control, N-AC, and ZnPP groups underwent induction of ventricular fibrillation (VF), 8 min untreated VF and cardiopulmonary resuscitation. Renal function indicators, were detected using commercial kits. Renal pathologic changes were assessed by haematoxylin–eosin (HE) staining. Oxidative stress and inflammatory responses were measured using the corresponding indicators. Apoptosis was evaluated using terminal uridine nick-end labeling (TUNEL) staining, and expression of proteins associated with apoptosis and the Nrf-2/HO-1 pathway was measured by western blotting.

Results

N-AC inhibited post-resuscitation AKI. We observed that N-AC reduced the levels of biomarkers of renal function derangement; improved renal pathological changes; and suppressed apoptosis, oxidative stress, and inflammatory response. Additionally, the production of ROS in the kidneys markedly decreased by N-AC. More importantly, compared with the control group, N-AC further upregulated the expression of nuclear Nrf2 and endogenous HO-1 in N-AC group. However, N-AC-determined protective effects on post-resuscitation AKI were markedly reversed after pretreatment of the HO-1 inhibitor zinc protoporphyrin (ZnPP).

Conclusions

N-AC alleviated renal dysfunction and prolonged survival in animal models of CA. N-AC partially exerts beneficial renal protection via activation of the Nrf-2/HO-1 pathway. Altogether, all these findings indicated that N-AC as a common clinical agent, may have the potentially clinical utility to improve patients the outcomes in cardiac arrest.

FUN14 Domain Containing 1 (FUNDC1): A Promising Mitophagy Receptor Regulating Mitochondrial Homeostasis in Cardiovascular Diseases

Mitochondria, the intracellular organelles for cellular aerobic respiration and energy production, play an important role in the regulation of cell metabolism and cell fate. Mitophagy, a selective form of autophagy, maintains dynamic homeostasis of cells through targeting long-lived or defective mitochondria for timely clearance and recycling. Dysfunction in mitophagy is involved in the molecular mechanism responsible for the onset and development of human diseases. FUN14 domain containing 1 (FUNDC1) is a mitochondrial receptor located in the outer mitochondria membrane (OMM) to govern mitophagy process. Emerging evidence has demonstrated that levels and phosphorylation states of FUNDC1 are closely related to the occurrence, progression and prognosis of cardiovascular diseases, indicating a novel role for this mitophagy receptor in the regulation of mitochondrial homeostasis in cardiovascular system. Here we review mitophagy mediated by FUNDC1 in mitochondria and its role in various forms of cardiovascular diseases.

Mechanisms and clinical implications of endothelium-dependent vasomotor dysfunction in coronary microvasculature

Coronary microvascular disease (CMD), which affects the arterioles and capillary endothelium that regulate myocardial perfusion, is an increasingly recognized source of morbidity and mortality, particularly in the setting of metabolic syndrome. The coronary endothelium plays a pivotal role in maintaining homeostasis, though factors such as diabetes, hypertension, hyperlipidemia, and obesity can contribute to endothelial injury and consequently arteriolar vasomotor dysfunction. These disturbances in the coronary microvasculature clinically manifest as diminished coronary flow reserve, which is a known independent risk factor for cardiac death, even in the absence of macrovascular atherosclerotic disease. Therefore, a growing body of literature has examined the molecular mechanisms by which coronary microvascular injury occurs at the level of the endothelium and the consequences on arteriolar vasomotor responses. This review will begin with an overview of normal coronary microvascular physiology, modalities of measuring coronary microvascular function, and clinical implications of CMD. These introductory topics will be followed by a discussion of recent advances in the understanding of the mechanisms by which inflammation, oxidative stress, insulin resistance, hyperlipidemia, hypertension, shear stress, endothelial cell senescence, and tissue ischemia dysregulate coronary endothelial homeostasis and arteriolar vasomotor function.

PPARβ/δ priming enhances the anti-apoptotic and therapeutic properties of mesenchymal stromal cells in myocardial ischemia-reperfusion injury

BACKGROUND

Mesenchymal Stromal Cells (MSC) have been widely used for their therapeutic properties in many clinical applications including myocardial infarction. Despite promising preclinical results and evidences of safety and efficacy in phases I/ II, inconsistencies in phase III trials have been reported. In a previous study, we have shown using MSC derived from the bone marrow of PPARβ/δ (Peroxisome proliferator-activated receptors β/δ) knockout mice that the acute cardioprotective properties of MSC during the first hour of reperfusion are PPARβ/δ-dependent but not related to the anti-inflammatory effect of MSC. However, the role of the modulation of PPARβ/δ expression on MSC cardioprotective and anti-apoptotic properties has never been investigated.

OBJECTIVES

The aim of this study was to investigate the role of PPARβ/δ modulation (inhibition or activation) in MSC therapeutic properties in vitro and ex vivo in an experimental model of myocardial infarction.

METHODS AND RESULTS

Naïve MSC and MSC pharmacologically activated or inhibited for PPARβ/δ were challenged with H₂O₂. Through specific DNA fragmentation quantification and qRT-PCR experiments, we evidenced in vitro an increased resistance to oxidative stress in MSC pre-treated by the PPARβ/δ agonist GW0742 versus naïve MSC. In addition, PPARβ/δ-priming allowed to reveal the anti-apoptotic effect of MSC on cardiomyocytes and endothelial cells in vitro. When injected during reperfusion, in an ex vivo heart model of myocardial infarction, 3.75 × 10⁵ PPARβ/δ-primed MSC/heart provided the same cardioprotective efficiency than 7.5 × 10⁵ naïve MSC, identified as the optimal dose in our experimental model. This enhanced short-term cardioprotective effect was associated with an increase in both anti-apoptotic effects and the number of MSC detected in the left ventricular wall at 1 h of reperfusion. By contrast, PPARβ/δ inhibition in MSC before their administration in post-ischemic hearts during reperfusion decreased their cardioprotective effects.

CONCLUSION

Altogether these results revealed that PPARβ/δ-primed MSC exhibit an increased resistance to oxidative stress and enhanced anti-apoptotic properties on cardiac cells in vitro. PPARβ/δ-priming appears as an innovative strategy to enhance the cardioprotective effects of MSC and to decrease the therapeutic injected doses. These results could be of major interest to improve MSC efficacy for the cardioprotection of injured myocardium in AMI patients.

Receptor-Interacting Protein Kinase 3 Suppresses Mitophagy Activation via the Yes-Associated Protein/Transcription Factor EB Pathways in Septic Cardiomyopathy

Mitophagy, known as the main mechanism of mitochondrial quality control, determines the pathophysiology of septic cardiomyopathy, although the precise regulatory mechanisms remain elusive. Data from the present study suggested that receptor-interacting protein kinase 3 (RIPK3) expression could be enhanced in response to lipopolysaccharide (LPS) challenge. Upregulated RIPK3 expression was accompanied by severe cardiac injury and cardiac dysfunction. Further examination revealed that elevated RIPK3 expression subsequently inhibited the Yes-associated protein (YAP) pathway, which was accompanied by reduced transcription factor EB (TFEB) expression. Inhibition of TFEB would reduce mitophagy, which ultimately induced cardiomyocyte death under LPS challenge. In contrast, loss of RIPK3 induced the YAP/TFEB/mitophagy pathway alleviated the sensitivity of cardiomyocytes to LPS-induced cytotoxicity. Collectively, the RIPK3/YAP/TFEB axis was confirmed to be responsible for the pathogenesis of septic cardiomyopathy by inhibiting mitophagy. These findings have potential significance for the progression of new approaches to the treatment of septic cardiomyopathy.

Transcription factor JDP2 activates PDE4B to participate in hypoxia/reoxygenation‑induced H9c2 cell injury

Myocardial ischemia/reperfusion (I/R) injury is a clinical challenge in the treatment of acute myocardial infarction (AMI). Phosphodiesterase 4B (PDE4B) expression is upregulated in AMI tissues. Thus, the present study aimed to investigate the role of PDE4B in myocardial I/R injury. H9c2 cardiomyocytes were subjected to hypoxia/reoxygenation (H/R) to establish an in vitro myocardial I/R model. PDE4B expression was detected via reverse transcription-quantitative PCR (RT-qPCR) and western blotting before and after transfection with PDE4B interference plasmids in H/R-stimulated H9c2 cells. Cell viability and cytotoxicity were assessed using the Cell Counting Kit-8 and lactate dehydrogenase assays, respectively. Furthermore, oxidative stress was assessed using malondialdehyde, superoxide dismutase and glutathione/glutathione oxidized ratio detection kits. Cell apoptosis was detected via a TUNEL assay and western blotting. c-Jun dimerization protein 2 (JDP2) expression was also detected via RT-qPCR and western blotting. The dual luciferase reporter and chromatin immunoprecipitation assays were performed to verify the interaction between JDP2 and PDE4B. Following co-transfection with PDE4B interference plasmid and JDP2 overexpression plasmid, cell viability, cytotoxicity, oxidative stress and cell apoptosis were assessed. The results demonstrated that PDE4B knockdown reversed H/R-induced loss of viability and cytotoxicity of H9c2 cells. H/R-induced oxidative stress and cardiomyocyte apoptosis were also alleviated by PDE4B knockdown. In addition, the transcription factor JDP2 was expressed at high levels in H/R-stimulated H9c2 cells, and JDP2 overexpression upregulated PDE4B expression. Notably, JDP2 overexpression partly reversed the ameliorative effect of PDE4B knockdown on H/R-induced H9c2 injury. Taken together, the results of the present study suggested that JDP2-activated PDE4B contributed to H/R-induced H9c2 cell injury.

Oxidative Stress, Inflammation and Connexin Hemichannels in Muscular Dystrophies

Muscular dystrophies (MDs) are a heterogeneous group of congenital neuromuscular disorders whose clinical signs include myalgia, skeletal muscle weakness, hypotonia, and atrophy that leads to progressive muscle disability and loss of ambulation. MDs can also affect cardiac and respiratory muscles, impairing life-expectancy. MDs in clude Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy and limb-girdle muscular dystrophy. These and other MDs are caused by mutations in genes that encode proteins responsible for the structure and function of skeletal muscles, such as components of the dystrophin-glycoprotein-complex that connect the sarcomeric-actin with the extracellular matrix, allowing contractile force transmission and providing stability during muscle contraction. Consequently, in dystrophic conditions in which such proteins are affected, muscle integrity is disrupted, leading to local inflammatory responses, oxidative stress, Ca²⁺-dyshomeostasis and muscle degeneration. In this scenario, dysregulation of connexin hemichannels seem to be an early disruptor of the homeostasis that further plays a relevant role in these processes. The interaction between all these elements constitutes a positive feedback loop that contributes to the worsening of the diseases. Thus, we discuss here the interplay between inflammation, oxidative stress and connexin hemichannels in the progression of MDs and their potential as therapeutic targets.

Mitophagy alleviates ischemia/reperfusion-induced microvascular damage through improving mitochondrial quality control

The coronary arteries mainly function to perfuse the myocardium. When coronary artery resistance increases, myocardial perfusion decreases and myocardial remodeling occurs. Mitochondrial damage has been regarded as the primary cause of microvascular dysfunction. In the present study, we explored the effects of mitophagy activation on microvascular damage. Hypoxia/reoxygenation injury induced mitochondrial oxidative stress, thereby promoting mitochondrial dysfunction in endothelial cells. Mitochondrial impairment induced apoptosis, reducing the viability and proliferation of endothelial cells. However, supplementation with the mitophagy inducer urolithin A (UA) preserved mitochondrial function by reducing mitochondrial oxidative stress and stabilizing the mitochondrial membrane potential in endothelial cells. UA also sustained the viability and improved the proliferative capacity of endothelial cells by suppressing apoptotic factors and upregulating cyclins D and E. In addition, UA inhibited mitochondrial fission and restored mitochondrial fusion, which reduced the proportion of fragmented mitochondria within endothelial cells. UA enhanced mitochondrial biogenesis in endothelial cells by upregulating sirtuin 3 and peroxisome proliferator-activated receptor gamma coactivator 1-alpha. These results suggested that activation of mitophagy may reduce hypoxia/reoxygenation-induced cardiac microvascular damage by improving mitochondrial quality control and increasing cell viability and proliferation.

Melatonin Attenuates Ischemia/Reperfusion-Induced Oxidative Stress by Activating Mitochondrial Fusion in Cardiomyocytes

Myocardial ischemia/reperfusion (I/R) injury can stimulate mitochondrial reactive oxygen species production. Optic atrophy 1- (OPA1-) induced mitochondrial fusion is an endogenous antioxidative mechanism that preserves the mitochondrial function. In our study, we investigated whether melatonin augments OPA1-dependent mitochondrial fusion and thus maintains redox balance during myocardial I/R injury. In hypoxia/reoxygenation- (H/R-) treated H9C2 cardiomyocytes, melatonin treatment upregulated OPA1 mRNA and protein expression, thereby enhancing mitochondrial fusion. Melatonin also suppressed apoptosis in H/R-treated cardiomyocytes, as evidenced by increased cell viability, diminished caspase-3 activity, and reduced Troponin T secretion; however, silencing OPA1 abolished these effects. H/R treatment augmented mitochondrial ROS production and repressed antioxidative molecule levels, while melatonin reversed these changes in an OPA1-dependent manner. Melatonin also inhibited mitochondrial permeability transition pore opening and maintained the mitochondrial membrane potential, but OPA1 silencing prevented these outcomes. These results illustrate that melatonin administration alleviates cardiomyocyte I/R injury by activating OPA1-induced mitochondrial fusion and inhibiting mitochondrial oxidative stress.

Pterostilbene alleviates liver ischemia/reperfusion injury via PINK1-mediated mitophagy

Hepatic ischemia/reperfusion (I/R) injury contributes to morbidity and mortality during liver resection or transplantation, with limited effective treatments available. Here, we investigated the potential benefits and underlying mechanisms of pterostilbene (Pt), a natural component of blueberries and grapes, in preventing hepatic I/R injury. Male C57BL/6 mice subjected to partial warm hepatic I/R and human hepatocyte cell line L02 cells exposed to anoxia/reoxygenation (A/R) were used as in vivo and in vitro models, respectively. Our findings showed that pretreatment with Pt ameliorated hepatic I/R injury by improving liver histology, decreasing hepatocyte apoptosis, and reducing plasma ALT and AST levels. Likewise, cell apoptosis, mitochondrial membrane dysfunction, and mitochondrial ROS overproduction in L02 cells triggered by the A/R challenge in vitro were reduced due to Pt administration. Mechanistically, Pt treatment efficiently enhanced mitophagy and upregulated PINK1, Parkin, and LC3B expression. Notably, the protective effect of Pt was largely abrogated after cells were transfected with PINK1 siRNA. Moreover, Pt pretreatment promoted hepatocyte proliferation and liver regeneration in the late phase of hepatic I/R. In conclusion, our findings provide evidence that Pt exerts hepatoprotective effects in hepatic I/R injury by upregulating PINK1-mediated mitophagy.

BI-1 ameliorates myocardial injury by activating the mitochondrial unfolded protein response and FUNDC1-related mitophagy in cardiorenal syndrome type 3

It has been suggested that mitochondrial dysfunction underlies the myocardial injury seen following cardiorenal syndrome type 3 (CRS-3). Both mitophagy and the mitochondrial unfolded protein response (UPR^mt) are protective programs that preserve mitochondrial homeostasis. Here, we explored whether Bax inhibitor-1 (BI-1) overexpression attenuates CRS-3-related myocardial injury through activation of mitophagy and the UPR^mt in cardiomyocytes. Following CRS-3 induction via renal ischemia-reperfusion injury, BI-1 transgenic (BI1^TG) mice showed greater preservation of myocardial integrity and relaxation function and less cardiomyocyte apoptosis than wild-type (WT) mice. Moreover, BI-1 overexpression attenuated CRS-3-mediated myocardial inflammation, as indicated by decreased MCP-1 and IL-6 expression and normalized ATP production in cardiomyocytes. After CRS-3 induction, mitophagy was inhibited in cardiomyocytes from WT mice, as indicated by both decreased Fundc1 transcription and mt-Keima fluorescence, and modest activation of the UPR^mt, denoted by a slight increase in Atf6 mRNA levels. By contrast, activation of mitophagy and marked UPR^mt upregulation were observed in cardiac tissue from BI1^TG mice. shRNA-mediated silencing of Fundc1 or Atf6 greatly impaired mitochondrial metabolism and survival in cultured cardiomyocytes overexpressing BI-1. Thus, upregulation of BI-1 expression aimed at activating mitophagy and the UPR^mt may represent a useful therapeutic approach for the treatment of CRS-3.

Febuxostat treatment attenuates oxidative stress and inflammation due to ischemia-reperfusion injury through the necrotic pathway in skin flap of animal model

BACKGROUND

Ischemia-reperfusion (I/R) injury is a major contributor to skin flap necrosis, which is a serious complication of reconstructive surgery. The purpose of this study was to evaluate the protective effect of treatment with febuxostat, a selective xanthine oxidase inhibitor, on I/R injury in the skin flap of an animal (rat) model.

METHODS

Superficial epigastric flaps were raised in Sprague-Dawley rats and subjected to ischemia for 3 h. Febuxostat at a dose of 10 mg/kg/day was administered to rats in drinking water from 1 week before the surgery (Feb group). Control animals received no drugs (Con group). The mean ratio of flap survival and contraction was evaluated and compared between animals with and without administration of febuxostat on day 5 after the surgery. In addition, infiltration by polymorphonuclear leukocytes and muscles of the panniculus carnosus in the flap were histologically evaluated using hematoxylin-eosin staining. Furthermore, xanthine oxidase activity, ATP levels, superoxide dismutase activity, and expression of 8-hydroxy-2'-deoxyguanosine (8-OHdG), tumor necrosis factor-α, and interleukin-1β were quantitatively assessed in the skin flap 24 h after the surgery.

RESULTS

In the Feb group, the survival and contraction rates at the 5 d timepoint post-surgery were significantly higher and lower than those in the Con group, respectively. Histological analysis showed significant reduction in polymorphonuclear leukocyte infiltration and muscle injury scores due to I/R injury in the Feb group. The expression of 8-OHdG was also significantly inhibited in animals administered febuxostat. Biochemical analysis showed a significant reduction in xanthine oxidase activity and significant increases in ATP levels and superoxide dismutase activity in the Feb group. Furthermore, the expression of interleukin-1β was significantly lower in the Feb group than in the Con group.

CONCLUSION

Febuxostat, which is clinically used for the treatment of hyperuricemia, was effective against necrosis of the skin flap via inhibition of oxidative stress and inflammation caused by I/R injury.

Lycopene Regulates Dietary Dityrosine-Induced Mitochondrial-Lipid Homeostasis by Increasing Mitochondrial Complex Activity

SCOPE

Dityrosine (DT), a marker of protein oxidation, is widely found in many high-protein foods. Dietary intake of DT induces myocardial oxidative stress injury and impairs energy metabolism. Lycopene is a common dietary supplement with antioxidant and mitochondrial-lipid homeostasis modulating abilities. This study aimed to examine the effects of lycopene on DT-induced disturbances in myocardial function and energy metabolism.

METHODS AND RESULTS

Four-week-old C57BL/6J mice received intragastric administration of either tyrosine (420 µg kg^-1 BW), DT (420 µg kg^-1 BW), or lycopene at high (10 mg kg^-1 BW) and low (5 mg kg^-1 BW) doses for 35 days. Lycopene administration effectively reduced oxidative stress, cardiac fatty acid accumulation, and cardiac hypertrophy and improved mitochondrial performance in DT-induced mice. In vitro experiments in H9c2 cells showed that DT directly inhibited the activity of the respiratory chain complex, whereas oxidative phosphorylation and β-oxidation gene expression is upregulated. Lycopene enhanced the activity of the complexes and inhibited ROS production caused by compensatory regulation.

CONCLUSION

Lycopene improves DT-mediated myocardial energy homeostasis disorder by promoting the activity of respiratory chain complexes I and IV and alleviates the accumulation of cardiac fatty acids and myocardial hypertrophy.

MKP-1 Overexpression Reduces Postischemic Myocardial Damage through Attenuation of ER Stress and Mitochondrial Damage

Mitochondrial dysfunction and endoplasmic reticulum (ER) stress contribute to postischemic myocardial damage, but the upstream regulatory mechanisms have not been identified. In this study, we analyzed the role of mitogen-activated protein kinase (MAPK) phosphatase 1 (MKP-1) in the regulation of mitochondrial function and ER stress in hypoxic cardiomyocytes. Our results show that MKP-1 overexpression sustains viability and reduces hypoxia-induced apoptosis among H9C2 cardiomyocytes. MKP-1 overexpression attenuates ER stress and expression of ER stress genes and improves mitochondrial function in hypoxia-treated H9C2 cells. MKP-1 overexpression also increases ATP production and mitochondrial respiration and attenuates mitochondrial oxidative damage in hypoxic cardiomyocytes. Moreover, our results demonstrate that ERK and JNK are the downstream signaling targets of MKP-1 and that MKP-1 overexpression activates ERK, while it inhibits JNK. Inhibition of ERK reduces the ability of MKP-1 to preserve mitochondrial function and ER homeostasis in hypoxic cardiomyocytes. These results show that MKP-1 plays an essential role in the regulation of mitochondrial function and ER stress in hypoxic H9C2 cardiomyocytes through normalization of the ERK pathway and suggest that MKP-1 may serve as a novel target for the treatment of postischemic myocardial injury.

Levosimendan in rats decreases acute kidney injury after cardiopulmonary resuscitation by improving mitochondrial dysfunction

Background

Acute kidney injury (AKI), the most common complication after cardiac resuscitation, is highly prevalent and harmful. There is increasing evidence that levosimendan can improve cardiac output, increase renal blood flow, and prevent AKI. As a novel calcium sensitizer, levosimendan may exert its protective effect via mitochondria.

Methods

Rat models of asphyxia-induced cardiac arrest and cardiopulmonary resuscitation (CPR) were set up. Thirty healthy adult male SD rats were randomly divided into CPR group (CPR group, n=10), levosimendan-treated group (levo group, n=10), and sham-operated group (sham group, n=10). Twelve hours after CPR, serum renal function indicators were measured, the kidney injury and mitochondrial morphological changes were observed. Oxygen uptake of the mitochondria, mitochondrial adenosine triphosphate (ATP) and mitochondrial free Ca²⁺ concentration were measured. Oxidative stress-related indicator levels in rat kidney tissues were further detected to analyze the differences in apoptosis rates among these three groups. Mitochondrial optic atrophy 1 (Opa1), dynamin-related protein 1 (Drp1), and apoptosis-related proteins were detected using Western blotting.

Results

Compared with the sham group, the CPR group had a significant increase in renal tissue damage. PAS staining and HE stains confirmed that CPR led to renal histopathological damage and destruction of the mitochondrial structure. Levosimendan improved the histopathological and ultrastructural damages of kidneys. Further analysis revealed that mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (CSH-Px) decreased. Free Ca²⁺ concentration and malondialdehyde (MDA) significantly increased (all P<0.05) in the kidney tissues of rats in the CPR group. However, mitochondrial ATP content, NADH dehydrogenase, succinate dehydrogenase/cytochrome C oxidase, SOD, CAT, and CSH-Px increased, whereas free Ca²⁺ concentration and MDA decreased (all P<0.05) in the levo group. The apoptosis rate increased in the CPR group. There were significantly increased levels of Drp1 protein levels, and significantly decreased Opa1 expression (all P<0.05). However, the levo group showed the opposite effects (all P<0.05).

Conclusions

Levosimendan can alleviate AKI following CPR, which may be achieved by improving mitochondrial dysfunction and suppressing the mitochondrial apoptosis pathway.

LATS2 Deletion Attenuates Myocardial Ischemia-Reperfusion Injury by Promoting Mitochondrial Biogenesis

Reperfusion therapy is the most effective treatment for acute myocardial infarction, but it can damage cardiomyocytes through a mechanism known as myocardial ischemia/reperfusion injury (MIRI). In this study, we investigated whether the large tumor suppressor kinase 2 (LATS2) contributes to the development of myocardial MIRI by disrupting mitochondrial biogenesis. Our in vitro data demonstrate that cardiomyocyte viability was reduced and apoptosis was increased in response to hypoxia/reoxygenation (H/R) injury. However, suppression of LATS2 by shRNA sustained cardiomyocyte viability by maintaining mitochondrial function. Compared to H/R-treated control cardiomyocytes, cardiomyocytes transfected with LATS2 shRNA exhibited increased mitochondrial respiration, improved mitochondrial ATP generation, and more stable mitochondrial membrane potential. LATS2 suppression increased cardiomyocyte viability and mitochondrial biogenesis in a manner dependent on PGC1α, a key regulator of mitochondrial metabolism. These results identify LATS2 as a new inducer of mitochondrial damage and myocardial MIRI and suggest that approaches targeting LATS2 or mitochondrial biogenesis may be beneficial in the clinical management of cardiac MIRI.

LncRNA HCP5 in hBMSC-derived exosomes alleviates myocardial ischemia reperfusion injury by sponging miR-497 to activate IGF1/PI3K/AKT pathway

Ischemia/reperfusion (I/R) injury is an inevitable process during heart transplant and suppressing I/R injury could greatly improve the survival rate of recipients. Mesenchymal stem cells (MSCs) have positive effects on I/R. We aimed to investigate the mechanisms underlying the protective roles of MSCs in I/R. Both cell model and rat model of myocardial I/R were used. MTT assay and flow cytometry were used to measure cell viability and apoptosis, respectively. QRT-PCR and western blotting were employed to measure levels of lncRNA HCP5 (HLA complex P5), miR-497, apoptosis-related proteins, and insulin-like growth factor (IGF1)/PI3K/AKT pathway. Dual luciferase assay was used to validate interactions of HCP5 and miR-497, miR-497 and IGF1. Echocardiography was performed to evaluate cardiac function of rats. Serum levels of CK-MB and LDH were measured. H&E and Masson staining were used to examine morphology of myocardial tissues. hBMSC-derived exosomes (hBMSC-Exos) increased the viability of cardiomyocytes following hypoxia/reperfusion (H/R) and decreased apoptosis. H/R diminished HCP5 expression in cardiomyocytes while hBMSC-Exos recovered the level. Overexpression of HCP5 in hBMSC-Exos further enhanced the protective effects in H/R while HCP5 knockdown suppressed. HCP5 directly bound miR-497 and miR-497 targeted IGF1. miR-497 mimics or si-IGF1 blocked the effects of HCP5 overexpression. Further, hBMSC-Exos alleviated I/R injury in vivo and knockdown of HCP5 in hBMSC-Exos decreased the beneficial effects. AntagomiR-497 blocked the effects of HCP5 knockdown. HCP5 from hBMSC-Exos protects cardiomyocytes against I/R injury via sponging miR-497 to disinhibit IGF1/PI3K/AKT pathway. These results shed light on mechanisms underlying the protective role of hBMSC-Exos in I/R.

Protective Effect of Nicorandil on Cardiac Microvascular Injury: Role of Mitochondrial Integrity

A major shortcoming of postischemic therapy for myocardial infarction is the no-reflow phenomenon due to impaired cardiac microvascular function including microcirculatory barrier function, loss of endothelial activity, local inflammatory cell accumulation, and increased oxidative stress. Consequently, inadequate reperfusion of the microcirculation causes secondary ischemia, aggravating the myocardial reperfusion injury. ATP-sensitive potassium ion (KATP) channels regulate the coronary blood flow and protect cardiomyocytes from ischemia-reperfusion injury. Studies in animal models of myocardial ischemia-reperfusion have illustrated that the opening of mitochondrial KATP (mito-KATP) channels alleviates endothelial dysfunction and reduces myocardial necrosis. By contrast, blocking mito-KATP channels aggravates microvascular necrosis and no-reflow phenomenon following ischemia-reperfusion injury. Nicorandil, as an antianginal drug, has been used for ischemic preconditioning (IPC) due to its mito-KATP channel-opening effect, thereby limiting infarct size and subsequent severe ischemic insult. In this review, we analyze the protective actions of nicorandil against microcirculation reperfusion injury with a focus on improving mitochondrial integrity. In addition, we discuss the function of mitochondria in the pathogenesis of myocardial ischemia.

Mitophagy coordinates the mitochondrial unfolded protein response to attenuate inflammation-mediated myocardial injury

Mitochondrial dysfunction is a fundamental challenge in septic cardiomyopathy. Mitophagy and the mitochondrial unfolded protein response (UPR^mt) are the predominant stress-responsive and protective mechanisms involved in repairing damaged mitochondria. Although mitochondrial homeostasis requires the coordinated actions of mitophagy and UPR^mt, their molecular basis and interactive actions are poorly understood in sepsis-induced myocardial injury. Our investigations showed that lipopolysaccharide (LPS)-induced sepsis contributed to cardiac dysfunction and mitochondrial damage. Although both mitophagy and UPR^mt were slightly activated by LPS in cardiomyocytes, their endogenous activation failed to prevent sepsis-mediated myocardial injury. However, administration of urolithin A, an inducer of mitophagy, obviously reduced sepsis-mediated cardiac depression by normalizing mitochondrial function. Interestingly, this beneficial action was undetectable in cardiomyocyte-specific FUNDC1 knockout (FUNDC1^CKO) mice. Notably, supplementation with a mitophagy inducer had no impact on UPR^mt, whereas genetic ablation of FUNDC1 significantly upregulated the expression of genes related to UPR^mt in LPS-treated hearts. In contrast, enhancement of endogenous UPR^mt through oligomycin administration reduced sepsis-mediated mitochondrial injury and myocardial dysfunction; this cardioprotective effect was imperceptible in FUNDC1^CKO mice. Lastly, once UPR^mt was inhibited, mitophagy-mediated protection of mitochondria and cardiomyocytes was partly blunted. Taken together, it is plausible that endogenous UPR^mt and mitophagy are slightly activated by myocardial stress and they work together to sustain mitochondrial performance and cardiac function. Endogenous UPR^mt, a downstream signal of mitophagy, played a compensatory role in maintaining mitochondrial homeostasis in the case of mitophagy inhibition. Although UPR^mt activation had no negative impact on mitophagy, UPR^mt inhibition compromised the partial cardioprotective actions of mitophagy. This study shows how mitophagy modulates UPR^mt to attenuate inflammation-related myocardial injury and suggests the potential application of mitophagy and UPR^mt targeting in the treatment of myocardial stress.

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Mitochondrial dysfunction is a fundamental challenge in septic cardiomyopathy.

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LPS-induced sepsis contributes to cardiac dysfunction and mitochondrial damage.

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Endogenous UPR^mt and mitophagy could be slightly activated by myocardial stress.

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Mitophagy modulates UPR^mt to attenuate inflammation-related myocardial injury.

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Mitophagy and UPR^mt targeting can be applied in treatment of myocardial stress.

Protective Effect of Optic Atrophy 1 on Cardiomyocyte Oxidative Stress: Roles of Mitophagy, Mitochondrial Fission, and MAPK/ERK Signaling

Myocardial infarction is associated with oxidative stress and mitochondrial damage. However, the regulatory mechanisms underlying cardiomyocyte oxidative stress during myocardial infarction are not fully understood. In the present study, we explored the cardioprotective action of optic atrophy 1- (Opa1-) mediated mitochondrial autophagy (mitophagy) in oxidative stress-challenged cardiomyocytes, with a focus on mitochondrial homeostasis and the MAPK/ERK pathway. Our results demonstrated that overexpression of Opa1 in cultured rat H9C2 cardiomyocytes, a procedure that stimulates mitophagy, attenuates oxidative stress and increases cellular antioxidant capacity. Activation of Opa1-mediated mitophagy suppressed cardiomyocyte apoptosis by downregulating Bax, caspase-9, and caspase-12 and upregulating Bcl-2 and c-IAP. Using mitochondrial tracker staining and a reactive oxygen species indicator, our assays showed that Opa1-mediated mitophagy attenuated mitochondrial fission and reduced ROS production in cardiomyocytes. In addition, we found that inhibition of the MAPK/ERK pathway abolished the antioxidant action of Opa1-mediated mitophagy in these cells. Taken together, our data demonstrate that Opa1-mediated mitophagy protects cardiomyocytes against oxidative stress damage through inhibition of mitochondrial fission and activation of MAPK/ERK signaling. These findings reveal a critical role for Opa1 in the modulation of cardiomyocyte redox balance and suggest a potential target for the treatment of myocardial infarction.

Reactive Oxygen Species-Induced TRPM2-Mediated Ca2+ Signalling in Endothelial Cells

Endothelial cells form the innermost layer of blood vessels with a fundamental role as the physical barrier. While regulation of endothelial cell function by reactive oxygen species (ROS) is critical in physiological processes such as angiogenesis, endothelial function is a major target for interruption by oxidative stress resulting from generation of high levels of ROS in endothelial cells by various pathological factors and also release of ROS by neutrophils. TRPM2 is a ROS-sensitive Ca²⁺-permeable channel expressed in endothelial cells of various vascular beds. In this review, we provide an overview of the TRPM2 channel and its role in mediating ROS-induced Ca²⁺ signaling in endothelial cells. We discuss the TRPM2-mediated Ca²⁺ signaling in vascular endothelial growth factor-induced angiogenesis and in post-ischemic neovascularization. In particular, we examine the accumulative evidence that supports the role of TRPM2-mediated Ca²⁺ signaling in endothelial cell dysfunction caused by various oxidative stress-inducing factors that are associated with tissue inflammation, obesity and diabetes, as well as air pollution. These findings provide new, mechanistic insights into ROS-mediated regulation of endothelial cells in physiology and diseases.

RIPK3 Induces Cardiomyocyte Necroptosis via Inhibition of AMPK-Parkin-Mitophagy in Cardiac Remodelling after Myocardial Infarction

Receptor-interacting protein 3- (RIPK3-) modulated necroptosis plays a critical role in cardiac remodelling after myocardial infarction (MI). However, the precise regulatory mechanism is not fully elucidated yet. In the present study, we showed that RIPK3 expression was upregulated in myocardial tissue after MI in a mouse model by coronary artery ligation, as well as in the cardiomyocytes following hypoxic injury in vitro. The increase of RIPK3 expression was found to be accompanied by severe cardiac remodelling, cardiac dysfunction, and higher mortality. Elevated RIPK3 expression subsequently abrogated the AMPK pathway that was accompanied by inhibition of Parkin-mediated mitophagy. Loss of mitophagy increased the opening of mitochondrial permeability transition pore (mPTP), which ultimately induced the cardiomyocyte necroptosis. In contrast, genetic ablation of Ripk3 induced the AMPK/Parkin-mitophagy pathway, favouring a prosurvival state that eventually inhibited mPTP opening and induced the necroptosis of cardiomyocytes in the post-MI cardiac remodelling. In conclusion, our results revealed a key mechanism by which necroptosis could be mediated by RIPK3 via the AMPK/Parkin-mitophagy/mPTP opening axis, which provides a potential therapeutic target in the management of heart failure after MI.

Bevacizumab-Induced Mitochondrial Dysfunction, Endoplasmic Reticulum Stress, and ERK Inactivation Contribute to Cardiotoxicity

The molecular mechanisms underlying the cardiotoxicity associated with bevacizumab, a first-line immunotherapeutic agent used to treat lung cancer, are not fully understood. Here, we examined intracellular signal transduction in cardiomyocytes after exposure to different doses of bevacizumab in vitro. Our results demonstrated that bevacizumab significantly and dose-dependently reduces cardiomyocyte viability and increases cell apoptosis. Bevacizumab treatment also led to mitochondrial dysfunction in cardiomyocytes, as evidenced by the decreased ATP production, increased ROS production, attenuated antioxidative enzyme levels, and reduced respiratory complex function. In addition, bevacizumab induced intracellular calcium overload, ER stress, and caspase-12 activation. Finally, bevacizumab treatment inhibited the ERK signaling pathway, which, in turn, significantly reduced cardiomyocyte viability and contributed to mitochondrial dysfunction. Together, our results demonstrate that bevacizumab-mediated cardiotoxicity is associated with mitochondrial dysfunction, ER stress, and ERK pathway inactivation. These findings may provide potential treatment targets to attenuate myocardial injury during lung cancer immunotherapy.

Mitochondrial quality surveillance as a therapeutic target in myocardial infarction

Myocardial infarction (MI) is a leading cause of morbidity and mortality worldwide. As mitochondrial dysfunction critically contributes to the pathogenesis of MI, intensive research is focused on the development of therapeutic strategies targeting mitochondrial homeostasis. Mitochondria possess a quality control system which maintains and restores their structure and function by regulating mitochondrial fission, fusion, biogenesis, degradation and death. In response to slight damage such as transient hypoxia or mild oxidative stress, mitochondrial metabolism shifts from oxidative phosphorylation to glycolysis, in order to reduce oxygen consumption and maintain ATP output. Mitochondrial dynamics are also activated to modify mitochondrial shape and structure, in order to meet cardiomyocyte energy requirements through augmenting or reducing mitochondrial mass. When damaged mitochondria cannot be repaired, poorly structured mitochondria will be degraded through mitophagy, a process which is often accompanied by mitochondrial biogenesis. Once the insult is severe enough to induce lethal damage in the mitochondria and the cell, mitochondrial death pathway activation is an inevitable consequence, and the cardiomyocyte apoptosis or necrosis program will be initiated to remove damaged cells. Mitochondrial quality surveillance is a hierarchical system preserving mitochondrial function and defending cardiomyocytes against stress. A failure of this system has been regarded as one of the potential pathologies underlying MI. In this review, we discuss the recent findings focusing on the role of mitochondrial quality surveillance in MI, and highlight the available therapeutic approaches targeting mitochondrial quality surveillance during MI.

Puerarin Attenuates LPS-Induced Inflammatory Responses and Oxidative Stress Injury in Human Umbilical Vein Endothelial Cells through Mitochondrial Quality Control

Atherosclerosis is closely associated with the inflammatory reaction of vascular endothelial cells. Puerarin (Pue), the main active component isolated from the rhizome of Pueraria lobata, is an isoflavone compound with potent antioxidant properties. Although Pue exhibits promising antiatherosclerotic pharmacological effects, only a few studies have reported its protective effect on endothelial cells. This study found that Pue could partly regulate mitochondrial function in human umbilical vein endothelial cells (HUVECs) and reduce or inhibit lipopolysaccharide-induced inflammatory reactions and oxidative stress injury in HUVECs, likely via mitochondrial quality control. Furthermore, the protective effect of Pue on HUVECs was closely related to the SIRT-1 signaling pathway. Pue increased autophagy and mitochondrial antioxidant potential via increased SIRT-1 expression, reducing excessive production of ROS and inhibiting the expression of inflammatory factors and oxidative stress injury. Therefore, Pue may improve mitochondrial respiratory function and energy metabolism, increasing the vulnerability of HUVECs to an inflammatory state.

MicroRNA mediated regulation of the major redox homeostasis switch, Nrf2, and its impact on oxidative stress-induced ischemic/reperfusion injury

Ischemia/reperfusion injury (IRI) initiates from oxidative stress caused by lack of blood supply and subsequent reperfusion. It is often associated with sterile inflammation, cell death and microvascular dysfunction, which ultimately results in myocardial, cerebral and hepatic IRIs. Reportedly, deregulation of Nrf2 pathway plays a significant role in the oxidative stress-induced IRIs. Further, microRNAs (miRNAs/miRs) are proved to regulate the expression and activation of Nrf2 by targeting either the 3'-UTR or the upstream regulators of Nrf2. Additionally, compounds (crocin, ZnSO4 and ginsenoside Rg1) that modulate the levels of the Nrf2-regulating miRNAs were found to exhibit a protective effect against IRIs of different organs. Therefore, the current review briefs the impact of ischemia reperfusion (I/R) pathogenesis in various organs, role of miRNAs in the regulation of Nrf2 and the I/R protective effect of compounds that alter their expression.

Matrine Protects Cardiomyocytes Against Hyperglycemic Stress by Promoting Mitofusin 2-Induced Mitochondrial Fusion

Matrine, an active component of Sophora flavescens Ait root extracts, has been used in China for years to treat cancer and viral hepatitis. In the present study, we explored the effects of matrine on hyperglycemia-treated cardiomyocytes. Cardiomyocyte function, oxidative stress, cellular viability, and mitochondrial fusion were assessed through immunofluorescence, quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assays, and RNA interference. Matrine treatment suppressed hyperglycemia-induced oxidative stress in cardiomyocytes by upregulating transcription of nuclear factor erythroid 2-like 2 and heme oxygenase-1. Matrine also improved cardiomyocyte contractile and relaxation function during hyperglycemia, and it reduced hyperglycemia-induced cardiomyocyte death by inhibiting mitochondrial apoptosis. Matrine treatment increased the transcription of mitochondrial fusion-related genes and thus attenuated the proportion of fragmented mitochondria in cardiomyocytes. Inhibiting mitochondrial fusion by knocking down mitofusin 2 (Mfn2) abolished the cardioprotective effects of matrine during hyperglycemia. These results demonstrate that matrine could be an effective drug to alleviate hyperglycemia-induced cardiomyocyte damage by activating Mfn2-induced mitochondrial fusion.

Coronary Endothelium No-Reflow Injury Is Associated with ROS-Modified Mitochondrial Fission through the JNK-Drp1 Signaling Pathway

Coronary artery no-reflow is a complex problem in the area of reperfusion therapy, and the molecular mechanisms underlying coronary artery no-reflow injury have not been fully elucidated. In the present study, we explored whether oxidative stress caused damage to coronary endothelial cells by inducing mitochondrial fission and activating the JNK pathway. The hypoxia/reoxygenation (H/R) model was induced in vitro to mimic coronary endothelial no-reflow injury, and mitochondrial fission, mitochondrial function, and endothelial cell viability were analyzed using western blotting, quantitative polymerase chain reaction (qPCR), enzyme-linked immunosorbent assay (ELISA), and immunofluorescence. Our data indicated that reactive oxygen species (ROS) were significantly induced upon H/R injury, and this was followed by decreased endothelial cell viability. Mitochondrial fission was induced and mitochondrial bioenergetics were impaired in cardiac endothelial cells after H/R injury. Neutralization of ROS reduced mitochondrial fission and protected mitochondrial function against H/R injury. Our results also demonstrated that ROS stimulated mitochondrial fission via JNK-mediated Drp1 phosphorylation. These findings indicate that the ROS-JNK-Drp1 signaling pathway may be one of the molecular mechanisms underlying endothelial cell damage during H/R injury. Novel treatments for coronary no-reflow injury may involve targeting mitochondrial fission and the JNK-Drp1 signaling pathway.

Mitochondria as a therapeutic target for cardiac ischemia‑reperfusion injury (Review)

Acute myocardial infarction is the leading cause of cardiovascular-related mortality and chronic heart failure worldwide. As regards treatment, the reperfusion of ischemic tissue generates irreversible damage to the myocardium, which is termed 'cardiac ischemia-reperfusion (IR) injury'. Due to the large number of mitochondria in cardiomyocytes, an increasing number of studies have focused on the roles of mitochondria in IR injury. The primary causes of IR injury are reduced oxidative phosphorylation during hypoxia and the increased production of reactive oxygen species (ROS), together with the insufficient elimination of these oxidative species following reperfusion. IR injury includes the oxidation of DNA, incorrect modifications of proteins, the disruption of the mitochondrial membrane and respiratory chain, the loss of mitochondrial membrane potential (∆Ψm), Ca²⁺ over-load, mitochondrial permeability transition pore formation, swelling of the mitochondria, and ultimately, cardiomyocyte necrosis. The present review article discusses the molecular mechanisms of IR injury, and summarizes the metabolic and dynamic changes occurring in the mitochondria in response to IR stress. The mitochondria are strongly recommended as a target for the development of therapeutic agents; however, the appropriate use of agents remains a challenge.

Voice perturbations under the stress overload in young individuals: phenotyping and suboptimal health as predictors for cascading pathologies

Verbal communication is one of the most sophisticated human motor skills reflecting both-the mental and physical health of an individual. Voice parameters and quality changes are usually secondary towards functional and/or structural laryngological alterations under specific systemic processes, syndrome and pathologies. These include but are not restricted to dry mouth and Sicca syndromes, body dehydration, hormonal alterations linked to pubertal, menopausal, and andropausal status, respiratory disorders, gastrointestinal reflux, autoimmune diseases, endocrinologic disorders, underweight versus overweight and obesity, and diabetes mellitus. On the other hand, it is well-established that stress overload is a significant risk factor of cascading pathologies, including but not restricted to neurodegenerative and psychiatric disorders, diabetes mellitus, cardiovascular disease, stroke, and cancers. Our current study revealed voice perturbations under the stress overload as a potentially useful biomarker to identify individuals in suboptimal health conditions who might be strongly predisposed to associated pathologies. Contextually, extended surveys applied in the population might be useful to identify, for example, persons at high risk for respiratory complications under pandemic conditions such as COVID-19. Symptoms of dry mouth syndrome, disturbed microcirculation, altered sense regulation, shifted circadian rhythm, and low BMI were positively associated with voice perturbations under the stress overload. Their functional interrelationships and relevance for cascading associated pathologies are presented in the article. Automated analysis of voice recordings via artificial intelligence (AI) has a potential to derive digital biomarkers. Further, predictive machine learning models should be developed that allows for detecting a suboptimal health condition based on voice recordings, ideally in an automated manner using derived digital biomarkers. Follow-up stratification and monitoring of individuals in suboptimal health conditions are recommended using disease-specific cell-free nucleic acids (ccfDNA, ctDNA, mtDNA, miRNA) combined with metabolic patterns detected in body fluids. Application of the cost-effective targeted prevention within the phase of reversible health damage is recommended based on the individualised patient profiling.

Total Glucosides of Peony Protect Cardiomyocytes against Oxidative Stress and Inflammation by Reversing Mitochondrial Dynamics and Bioenergetics

Total glucosides of peony (TGP) are used to treat rheumatoid arthritis and systemic lupus erythematosus. We explored the protective effects of TGP on cardiomyocyte oxidative stress and inflammation in the presence of hydrogen peroxide by focusing on mitochondrial dynamics and bioenergetics. Our study demonstrated that hydrogen peroxide significantly repressed cardiomyocyte viability and promoted cell apoptosis through induction of the mitochondrial death pathway. TGP treatment sustained cardiomyocyte viability, reduced cardiomyocyte apoptosis, and decreased inflammation and oxidative stress. Molecular investigation indicated that hydrogen peroxide caused mitochondrial dynamics disruption and bioenergetics reduction in cardiomyocytes, but this alteration could be normalized by TGP. We found that disruption of mitochondrial dynamics abolished the regulatory effects of TGP on mitochondrial bioenergetics; TGP modulated mitochondrial dynamics through the AMP-activated protein kinase (AMPK) pathway; and inhibition of AMPK alleviated the protective effects of TGP on mitochondria. Our results showed that TGP treatment reduces cardiomyocyte oxidative stress and inflammation in the presence of hydrogen peroxide by correcting mitochondrial dynamics and enhancing mitochondrial bioenergetics. Additionally, the regulatory effects of TGP on mitochondrial function seem to be mediated through the AMPK pathway. These findings are promising for myocardial injury in patients with rheumatoid arthritis and systemic lupus erythematosus.

A Preclinical Systematic Review of Curcumin for Protecting the Kidney with Ischemia Reperfusion Injury

Renal ischemia-reperfusion injury (RIRI) refers to a phenomenon associated with dysfunction of the kidney and tissue damage. Unfortunately, no specific drugs have been found that effectively prevent and treat RIRI. Curcumin (Cur), a polyphenol extracted from turmeric, possesses a variety of biological activities involving antioxidation, inhibition of apoptosis, inhibition of inflammation, and reduction of lipid peroxidation. Eight frequently used databases were searched using prespecified search strategies. The CAMARADES 10-item quality checklist was used to evaluate the risk of bias of included studies, and the RevMan 5.3 software was used to analyze the data. The risk of bias score of included studies ranged from 3 to 6 with an average score of 5.22. Compared with the control group, Cur significantly alleviated renal pathology, reduced blood urea nitrogen and serum creatinine levels, and improved inflammatory indexes, oxidant, and apoptosis in RIRI animal models. Despite the heterogeneity of the response to Cur in terms of serum creatinine, BUN, TNF-alpha, and SOD, its effectiveness for improving the injury of RIRI was remarkable. In the mouse model subgroup of serum creatinine, the effect size of the method of unilateral renal artery ligation with contralateral nephrectomy and shorter ischemic time showed a greater effect than that of the control group. No difference was seen in the methods of model establishment, mode administration, or medication times. The preclinical systematic review provided preliminary evidence that Cur partially improved RIRI in animal models, probably via anti-inflammatory, antioxidant, antiapoptosis, and antifibrosis activities and via improving microperfusion. ARRIVE guidelines are recommended; blinding and sample size calculation should be focused on in future studies. These data suggest that Cur is a potential renoprotective candidate for further clinical trials of RIRI.

Oxidized LDL Causes Endothelial Apoptosis by Inhibiting Mitochondrial Fusion and Mitochondria Autophagy

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial dysfunction is an initial step toward atherosclerosis development. Mitochondria damage correlates with ox-LDL-induced endothelial injury through an undefined mechanism. We explored the role of optic atrophy 1 (Opa1)-related mitochondrial fusion and mitophagy in ox-LDL-treated endothelial cells, focusing on mitochondrial damage and cell apoptosis. Oxidized low-density lipoprotein treatment reduced endothelial cell viability by increasing apoptosis. Endothelial cell proliferation and migration were also impaired by ox-LDL. At the molecular level, mitochondrial dysfunction was induced by ox-LDL, as demonstrated by decreased mitochondrial membrane potential, increased mitochondrial reactive oxygen species production, augmented mitochondrial permeability transition pore openings, and elevated caspase-3/9 activity. Mitophagy and mitochondrial fusion were also impaired by ox-LDL. Opa1 overexpression reversed this effect by increasing endothelial cell viability and decreasing apoptosis. Interestingly, inhibition of mitophagy or mitochondrial fusion through transfection of siRNAs against Atg5 or Mfn2, respectively, abolished the protective effects of Opa1. Our results illustrate the role of Opa1-related mitochondrial fusion and mitophagy in sustaining endothelial cell viability and mitochondrial homeostasis under ox-LDL stress.