MitoSOX Staining Research Articles

20-HETE mediates Ang II-induced cardiac hypertrophy via ROS and Ca2+ signaling in H9c2 cells

In the vascular system, angiotensin II (Ang II) mediated vasoconstriction by inducing the production of 20-hydroxyeicosatetraenoic acid (20-HETE). However, the role of 20-HETE in Ang II-induced cardiac dysfunction had yet to be fully elucidated. This study investigated the effects of Ang II on CYP4A expression and 20-HETE production in H9c2 cells using RT-qPCR, Western blot, and ELISA. The role of 20-HETE in Ang II-induced cardiac hypertrophy was examined using DHE, MitoSOX, and JC-1 staining to evaluate reactive oxygen species (ROS) generation and mitochondrial membrane potential changes. The ERK/Akt and CaN/NFAT3 signaling pathways were analyzed through Western blot. Ang II was found to promote CYP4A expression and 20-HETE production in H9c2 cells via an AT1 receptor-dependent mechanism. Additionally, the upregulation of AT1 receptor expression by 20-HETE further confirms its facilitatory effect on the Ang II signaling pathway. Inhibition of 20-HETE synthesis or blockade of its receptor, G-protein-coupled receptor 75 (GPR75), significantly reversed Ang II-induced cardiac hypertrophy. This reversal was closely associated with 20-HETE-induced ROS production, oxidative stress, and activation of the Ca2+/CaN/NFAT3 signaling pathway. This study demonstrated that 20-HETE mediated Ang II-induced cardiac hypertrophy and, for the first time, highlighted the significant role of the GPR75 receptor in this process. These findings suggested that targeting 20-HETE reduction or blocking its receptor action could offer a novel therapeutic approach for cardiovascular diseases associated with Ang II.

Dnmt3a-mediated DNA Methylation Regulates P. gingivalis-suppressed Cementoblast Mineralization Partially Via Mitochondria-dependent Apoptosis Pathway.

DNA methyltransferase 3A (Dnmt3a) is an enzyme that catalyzes the de novo methylation of DNA, and plays essential roles in a wide range of physiological and pathological processes. However, it remains unclear whether Porphyromonas gingivalis affects cementoblasts, the cells responsible for cementum formation, through Dnmt3a. The samples were collected from models of mouse periapical lesions and mice of different ages, and the expression of Dnmt3a was detected through immunofluorescence. Porphyromonas gingivalis was co-cultured with cementoblasts that simultaneously overexpressed Dnmt3a. Additionally, cementoblasts were subjected to either Dnmt3a knockout or DNA methylation inhibition. Changes in global DNA methylation were analyzed, and quantitative PCR, western blotting, alkaline phosphatase (ALP) activity assays, and Alizarin Red staining were employed to evaluate alterations in the mineralization capacity of cementoblasts.RNA sequencing further showed the mechanisms by which Dnmt3a regulated mineralization. Flow cytometry, MitoSox, and TRMR staining were used to verify the participation of mitochondria-dependent apoptosis. The effect of P. gingivalis on Dnmt3a and global DNA methylation in cementoblasts was first verified.Dnmt3a expression and global DNA methylation were upregulated during cementoblast mineralization. Samples with periapical inflammation exhibited reduced Dnmt3a expression. P. gingivalis stimulation reduced the global DNA methylation and the mineralization ability of cementoblasts. Both the knockdown of Dnmt3a and using DNA methylation inhibitors suppressed cementoblast mineralization. In addition, Dnm3a depletion was significantly correlated with the mitochondria-dependent apoptosis pathway in cementoblasts. P. gingivalis blocks DNA methylation by silencing Dnmt3a in cementoblasts, thereby inducing mitochondrial-dependent apoptosis and, ultimately, impaired cementogenesis.

Ailanthone blocks mitophagy to promote mtDNA leakage through BAX-BAK1 pores and suppress hepatocellular carcinoma cell proliferation.

Hepatocellular carcinoma (HCC), the third leading cancer mortality worldwide, shows rising incidence. The mitochondria in HCC cells are prone to damage from metabolic stress and oxidative stress, necessitating heightened mitophagy for mitochondrial homeostasis and cell survival. Thus, mitophagy inhibition is a promising HCC therapy. The traditional Chinese medicinal herb ailanthone have proved promote mitochondrial dysfunction and inhibits HCC. However, the underlying mechanism remains unclear. CCK8 assay was applied to detect the proliferation. JC-1, MitoTracker Red/Green and MitoSOX staining were applied to detect the mitochondrial homeostasis. Inflammatory factors were analysed via ELISA and WB assay. Mitochondria and cytoplasm separation, genome extraction and qPCR were used to detect mitochondrial DNA (mtDNA) leakage. Mitochondria ultrastructure was detected by transmission electron microscopy. WB and IHC experiments were applied to detect protein expression. Protein-protein interactions detected by immunoprecipitation and immunofluorescence imaging. The in vivo antitumor effect was validated by the xenograft mouse model. In this study, we demonstrated the potent anti-HCC properties of ailanthone and revealed its molecular mechanism. In vitro studies demonstrated that ailanthone effectively inhibited PINK1-PRKN mediated mitophagy and promoted BAX-BAK1 mitochondrial pores formation through PRKN inhibition. This process led to the mitochondrial mtDNA leakage into the cytoplasm, which subsequently triggered the induction of inflammatory factors. The inhibition of mitophagy and the activation of inflammatory response ultimately led to HCC proliferation inhibition. In vivo studies demonstrated that ailanthone exhibited stronger anti-HCC activity than 5-Fluorouracil (5-FU), with no significant adverse effects on animal body weight or the physiological functions of vital organs. This study highlighted the efficacy of ailanthone against HCC and elucidated its underlying molecular mechanisms, suggesting the promising therapeutic potential of ailanthone for HCC.

FSTL1 Can Be a Promising Target in TMJ Osteoarthritis via Regulating Chondrocyte Mitophagy and Apoptosis.

Previous studies have shown that follistatin-like protein 1 (FSTL1) is elevated in the synovial fluid of osteoarthritis and whether it is associated with disease development progress in cartilage degeneration is still unclear. The experiment was performed to explore the effect and mechanism of FSTL1 on chondrocyte degeneration and its further impaction in osteoarthritis as well as its treatment method. The patients who were diagnosed with temporomandibular joint (TMJ) disc displacement and osteoarthritis (OA) group was divided into 2 groups, anterior disc displacement (ADD) without bone resorption and ADD with bone resorption group according to the radiologic examination. The ELISA kit was used to determine the expression level of FSTL1 in patients TMJ environment. The function of FSTL1 in promoting chondrocyte degeneration was tested by quantitative reverse transcription polymerase chain reaction (Rt-qPCR) and western blot. The chondrocyte apoptosis and mitophagy were further test by flow cytometry and mitosox staining by upregulating and downregulating of FSTL1. In the end, the effectiveness of regulating FSTL1 in OA procedure was further validated by hematoxylin-eosin (HE), safranin O, and immunohistochemical (IHC) staining in vivo. There were 56 samples collected from the patients were included into this study. According to the ELISA results, FSTL1 expression levels of ADD without bone resorption groups were significantly lower than that in ADD with bone resorption group. Furthermore, the rate of cell apoptosis cells and the mitophagy procedure were highly activated when FSTL1 was upregulated. The morphology analysis of mitochondria showed significant changes when FSTL1 was highly upregulated in vitro. The in vivo and in vitro experiments showed that suppressing FSTL1 could alleviate the cartilage degeneration in TMJ OA progression. To sum up, upregulated expression level of FSTL1 in synovial fluid promoted the progression of TMJ OA by upregulating accelerating the chondrocyte apoptosis and mitophagy, and suppressing the FSTL1 in TMJ can rescue the OA progression. Therefore, it may be a promising result to consider the FSTL1 as a therapeutic target in the future.

Abstract 4140181: Mechanisms of SGLT-2 Inhibitor Empagliflozin in Attenuating Intramitochondrial Stress and Restoring Mitochondrial Function in Hyperglycemic Cardiomyocyte

Systemic hyperglycemia causes tissue damage and triggers cardiovascular disease (CVD). Sodium-glucose cotransporter-2 inhibitors (SGLT-2i) are a novel class of glucose-lowering agents that have shown unexpected benefits in clinical trials for the treatment of CVDs. We aim to investigate the underlying mechanisms of how SGLT-2 inhibitors alleviate CVDs associated with elevated glucose stress. iPSC-derived cardiomyocytes (iPSC-CM) were incubated with high glucose concentrations for 72 hours. Mitochondrial function in these cardiomyocytes was assessed by flow cytometry with JC-1 staining and ATP luminescence assay. Intracellular reactive oxygen species (ROS) and intramitochondrial calcium stress were measured using CellROX, MitoSOX, and Rhod-2 AM staining. Patch clamp was employed to determine ion current changes in the cardiomyocytes. Mitochondrial oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were determined using the Seahorse XFe96 analyzer. In addition, qPCR, Western blot, and DM mouse heart histological analysis were performed to assess the regulation of associated molecules. The results indicated that exposure to a high glucose environment caused cardiomyocyte injury and impaired mitochondrial biosynthesis. Empagliflozin exhibited a beneficial effect on mitochondrial function by reducing ROS production and calcium deposition. It also mitigated the reduction in respiratory OCR of cardiomyocytes induced by high glucose incubation. Furthermore, molecular analysis revealed that Empagliflozin attenuated the dysregulation of mitochondrial calcium channels and biosynthesis by reducing associated gene expression, including Bcl2 , Mfn1 , Mx2 , Oas1 , Ant3 , Mcu , Micu1 , Vdac1 , Ryr2 , and Cypd-ppid . Histological analysis of DM mouse hearts demonstrated that reduced MFN2 and ZBP1 were target molecules for hyperglycemia-induced reduction of calcium channel currents in cardiomyocytes and could be restored by Empagliflozin treatment. This study concludes that high glucose stress diminishes mitochondrial calcium channel regulators MFN2 and ZBP1 in cardiomyocyte, which reduces calcium channel currents and leads to sensitization of cardiomyocyte to arrhythmogenesis, resulting in VT/VF. It provides experimental evidence for the clinical efficacy of Empagliflozin in ameliorating CVDs and managing diabetes-related CVDs.

Activation, regulation, and effects of the mitochondrial unfolded protein response in endothelial cells

Abstract Introduction Endoplasmic reticulum stress and the resulting unfolded protein response (UPRER) play significant roles in endothelial dysfunction and atherosclerosis. However, the understanding of the mitochondrial unfolded protein response (UPRMito) in endothelial dysfunction is limited. This study aims to characterize the activation, regulation, and effects of the UPRMito to provide a comprehensive understanding of endothelial UPRMito. Methods and Results RNA sequencing and quantitative proteomic analysis were employed to investigate the impact of stressors on mitochondrial (MitoBlock-6, CDDO) and endoplasmic (Tunicamycin) protein homeostasis on the transcriptome and proteome of Human Coronary Artery Endothelial cells (HCAEC, Fig.1). The analysis identified 12,745 unique transcripts and 7,891 unique proteins. Mitocarta annotation highlighted the regulatory effect induced by these stressors, particularly on mitochondrial proteins and transcripts (Fig. 2). Geneset enrichment analyses revealed upregulation of pathways regulated by activating transcription factors 4/5 (ATF4/5) and the integrated stress response marker CHOP. Analysis of protein expression changes unveiled that 21 proteins were upregulated by both CDDO and MitoBlock-6, including essential mitochondrial chaperones (HSP10 and HSP60). In contrast, the UPRER stressor Tunicamycin did not induce canonical UPRMito activation. Additionally, 142 proteins were commonly downregulated, affecting crucial biological processes such as mitochondrial translation, mitochondrial gene expression, and ribosome biogenesis. Importantly, NAD+ADP-ribosyltransferase activity was highly downregulated, involving PARP proteins with roles in DNA damage repair. On a functional level, mitochondrial stressors led to dose-dependent alterations in HCAEC viability, apoptosis, and reactive oxygen species formation (ROS) measured by resazurin-based assays, caspase 3/7 activity, and MitoSox staining, respectively. Low doses and short incubations with mitochondrial stressors promoted endothelial cell health through cytoprotective UPRMito pathways, while prolonged incubation led to unresolvable mitochondrial stress (exemplarily shown in Fig. 3). SiRNA-mediated gene silencing of the UPRMito regulators ATF4 and ATF5 promoted mitochondrial ROS formation in cells treated with mitochondrial stressors. These effects were particularly more pronounced after ATF5-Knockdown, suggesting that ATF5 is the main regulator of the UPRMito in HCAEC (Fig. 4). Moreover, high-dose UPRMito stressors led to an impairment in mitochondrial membrane integrity with cytosolic release of pro-inflammatory mtDNA. Conclusion UPRMito and UPRER lead to a different stress response. Depending on the underlying conditions, both stress responses can exert both cytoprotective and cytotoxic effects. Further studies are required to analyze the in vivo relevance and possible therapeutic exploitation of the UPRMito in endothelial dysfunction and atherosclerosis.Figures

The contributory role of GSK3β in hypertension exacerbating atherosclerosis by regulating the OMA1/PGC1α pathway.

Atherosclerosis is closely related to endothelial dysfunction and hypertension. GSK3β is a critical regulator in atherosclerosis. This study was carried out to investigate the effects of GSK3β on hypertension exacerbating atherosclerosis in vitro and in vivo. L-NAME + HFD-ApoE-/- mice were used for this study for 12 weeks, and their endothelial dysfunction and inflammation were analyzed. Oil red O and H&E staining revealed that treatment with LiCl, an inhibitor of GSK3β, reduced atherosclerotic lesions and lipid accumulation. The levels of lipid homeostasis and oxidation stress were attenuated following LiCl administration. LiCl-treated ApoE-/- mice showed lowered blood pressure. LiCl also suppressed the expressions of Drp1, Bax, ICAM1, VCAM1 and TNF-α compared to HFD + L-NAME induced mice and oxLDL + L-NAME-treated Human aorta endothelial cell line(HAECs). LiCl treatment increased the expressions of MFN2 and Bcl2. Mitotracker-red, MitoSOX and JC-1 staining indicated that LiCl treatment reduced mitochondrial division and ROS production, increased mitochondrial ΔΨm compared to oxLDL + L-NAME-treated HAECs. The expression of OMA1 was decreased by LiCl treatment, while PGC1α expression was increased. In HAECs, we found that OMA1 knockdown increased mitochondrial function and the expression of PGC1α. We also demonstrated LiCl increased OMA1 ubiquitination compared with the Control group, thus decreased OMA1 expression. Furthermore, siOMA1 antagonized the increased protein expressions of ICAM1, VCAM1, TNF-α, Bax and Drp1, decreased the protein expressions of Bcl2 and MFN2 by siPGC1α. Taken together, we demonstrated that GSK3β could play a contributory role in hypertension exacerbating atherosclerosis by regulating the OMA1/PGC1α pathway and inhibiting mitochondrial function.

12234 Gα13 Promotes Clonogenic Growth By Increasing Tolerance To Oxidative Metabolic Stress In Prostate Cancer Cells

Abstract Disclosure: D. Wu: None. W. Lim: None. X. Chai: None. V.P. Seshachalam: None. S.A. Rasheed: None. S. Ghosh: None. P.J. Casey: None. Gα13 and Gα12 are members of the G12 family of Gα proteins that, along with their associated Gβγ subunits, mediate signaling from specific G protein-coupled receptors. Analyses of tumor specimens indicate that Gα13 expression correlates with patient survival in several solid cancers. We previously reported a role for Gα13 in cell migration and invasion in prostate cancer cell lines. Interestingly, patient data supports the notion that mitochondrial superoxide dismutase 2 (SOD2) correlates with prostate cancer risk and prognostic Gleason scores. Gα13 lower-expressing LNCaP cells also have lower SOD2 protein levels compared to the Gα13 higher-expressing PC3 cells. Hence, we explored the role of Gα13 in prostate tumorigenesis, and its effect on cellular processes such as cell survival and mitochondrial metabolism, in human prostate cancer cell lines PC3 and LNCaP. We stably knocked-down GNA13 expression in PC3 cells and overexpressed GNA13 in LNCaP cells. We found that Gα13 promoted anchorage-independent cell growth in PC3 and LNCaP cell lines, as assessed by soft agar colony formation, spheroid formation, and xenograft tumor growth. Whole-genome transcriptome analyses suggested that Gα13-regulated genes are functionally enriched in the mitochondria compartment and that GNA13 expression positively correlated to SOD2 transcript levels in PC3 cells. We found that silencing GNA13 sensitized PC3 cells to long-term oxidative metabolic stress when cultured in media containing non-glycolytic metabolites, namely galactose, glutamate plus malate, and succinate. Furthermore, Gα13 levels impacted the abundance of SOD2 protein in the mitochondria, as well as SOD2 promoter activity and mRNA expression. In addition, silencing GNA13 increased mitochondrial superoxide levels in PC3 cells when cultured in galactose medium, as assessed by MitoSOX staining and flow cytometry. Moreover, overexpression of SOD2 could rescue the effect of Gα13 loss on suppression of anchorage-independent cell growth in PC3 cells. Importantly, anchorage-independent cell growth was not rescued when a catalytically-inactive SOD2(Q167A) mutant was expressed. Likewise, stable knockdown of SOD2 suppressed the effect of overexpression of Gα13 on anchorage-independent cell growth in LNCaP cells. We propose a novel biological route of Gα13-mediated anchorage-independent growth and response to oxidative metabolic stress through regulation of SOD2 expression in prostate cancer cells. Given that SOD2 protein levels correlate with prostate cancer Gleason grade, identifying the upregulated GPCRs that signal through Gα13 in prostate cancer could lead to novel preventive or therapeutic strategies. Presentation: 6/1/2024

Abstract 35: The Dual Endothelin-1 Antagonist Aprocitentan Attenuates Mitochondrial Oxidative Stress in Human Cardiac Fibroblasts

Endothelin-1 (ET-1) is a peptide hormone primarily produced by endothelial cells that functions as a potent vasoconstrictor through two receptors, ETA and ETB. While most research on ET-1 has focused on endothelial dysfunction and hypertension, increasing evidence shows that ET-1 is also involved in other physiological processes such as cell proliferation, inflammation, and tissue remodeling. Dysregulation of ET-1 has been implicated in the pathogenesis of various diseases, including heart failure, atherosclerosis, fibrosis, systemic sclerosis, and cancer. Aprocitentan (also known as ACT-132577) is a relatively new dual ET-1 receptor antagonist that prevents ET-1 from binding to both endothelin receptors and has been shown to significantly reduce blood pressure in patients with resistant hypertension. Our hypothesis was that aprocitentan could reduce the proliferation rate and mitochondrial ROS production induced by TGF-β in human cardiac fibroblasts (HCFs). HCFs were isolated from hearts from fully de-identified cadaveric donors and cultured in cardiac fibroblast growth medium. HCFs were treated with aprocitentan (4 μM) and/or TGF-β1 (10 ng/ml) for 72 hours (doses and times identified in preliminary dose-response and time-course assays). Aprocitentan reduced the TGF-β1-induced proliferation rate in HCFs by approximately 23% ( Figure 1A ). Our study also aimed to determine if aprocitentan could mitigate mitochondrial dysfunction. Since the mitochondrion is a major source of reactive oxygen species (ROS), which can promote myofibroblast differentiation, mitochondrial properties in HCFs were assessed using MitoTracker Green and MitoSOX staining. TGF-β1 treatment increased mitochondrial ROS production, which was significantly reduced by aprocitentan ( Figure 1BC ); furthermore, aprocitentan reduced mitochondrial fragmentation induced by TGF-β1 treatment ( Figure 1D ). To the best of our knowledge, we are the first to demonstrate that aprocitentan can reduce the increased production of mitochondrial ROS, mitochondrial fragmentation, and cell proliferation rate induced by TGF-β1 in HCFs. This discovery could pave the way for new research and therapeutic strategies for treating fibrosis in cardiovascular disorders.

Piceatannol reduces radiation-induced DNA double-strand breaks by suppressing superoxide production and enhancing ATM-dependent repair efficiency

In contemporary society, humans are susceptible to various radiation-borne hazards, including exposure to therapeutic modalities using low-linear energy transfer (low-LET) radiations (X-rays and γ-rays), natural high-LET radiation sourced from cosmic rays, as well as nuclear accidents such as the Fukushima Daiichi Nuclear Power Plant incident. Therefore, this threat incites an imminent necessity to develop novel radioprotective agents against a wide range of LET radiation and elucidate the underlying molecular mechanisms. This study aimed at assessing the radioprotectivity of Piceatannol (PIC), a potent antioxidant polyphenol present in abundance in passion fruit, by investigating its effects on radiation-induced reactive oxygen species (ROS) production and the consequent DNA double-strand break (DSB) capacity and cellular senescence. Specifically, total ROS was evaluated by DCFDA staining, mitochondrial superoxide by MitoSOX staining, DSB by γ-H2AX immunostaining, and cellular senescence by Senescence-associated-β-galactosidase staining.The results demonstrated that PIC administration prior to exposure to both X-ray and high-LET radiation impeded radiation-induced DSB by suppressing ROS production. Interestingly, post-irradiation PIC treatment did not alter ROS levels but enhanced the efficiency of Ataxia Telangiectasia Mutated (ATM)-mediated DSB repair. Additionally, post-irradiation PIC treatment diminished senescence-associated beta-galactosidase levels, indicating that it hinders cellular senescence.Conclusively, PIC exerts radioprotective effects against a wide range of LET radiation. The study findings validate the potential application of PIC not only as a radical scavenger but also as a novel DSB repair-activating radioprotective agent.

Synergistic Activation of LEPR and ADRB2 Induced by Leptin Enhances ROS Generation in TNBC Cells.

Leptin interacts not only with leptin receptor (LEPR) but also engages with other receptors. While the pro-oncogenic effects of the adrenergic receptor β2 (ADRB2) are well-established, the role of leptin in activating ADRB2 in triple-negative breast cancer (TNBC) remains unclear. The pro-carcinogenic effects of LEPR were investigated using murine TNBC cell lines, 4T1 and EMT6, and a tumor-bearing mouse model. Expression levels of LEPR, NOX4, and ADRB2 in TNBC cells and tumor tissues were analyzed via Western blot and qPCR. Changes in reactive oxygen species (ROS) levels were assessed using flow cytometry and MitoSox staining, while immunofluorescence double-staining confirmed the co-localization of LEPR and ADRB2. LEPR activation promoted NOX4-derived ROS and mitochondrial ROS production, facilitating TNBC cell proliferation and migration, effects which were mitigated by the LEPR inhibitor Allo-aca. Co-expression of LEPR and ADRB2 was observed on cell membranes, and bioinformatics data revealed a positive correlation between the two receptors. Leptin activated both LEPR and ADRB2, enhancing intracellular ROS generation and promoting tumor progression, which was effectively countered by a specific ADRB2 inhibitor ICI118551. In vivo, leptin injection accelerated tumor growth and lung metastases without affecting appetite, while treatments with Allo-aca or ICI118551 mitigated these effects. This study demonstrates that leptin stimulates the growth and metastasis of TNBC through the activation of both LEPR and ADRB2, resulting in increased ROS production. These findings highlight LEPR and ADRB2 as potential biomarkers and therapeutic targets in TNBC.

Ciprofloxacin Accelerates Angiotensin-II-Induced Vascular Smooth Muscle Cells Senescence Through Modulating AMPK/ROS pathway in Aortic Aneurysm and Dissection

Aortic aneurysm and dissection (AAD) is a cardiovascular disease that poses a severe threat to life and has high morbidity and mortality rates. Clinical and animal-based studies have irrefutably shown that fluoroquinolones, a commonly prescribed antibiotic for treating infections, significantly increase the risk of AAD. Despite this, the precise mechanism by which fluoroquinolones cause AAD remains unclear. Therefore, this study aims to investigate the molecular mechanism and role of Ciprofloxacin definitively—a type of fluoroquinolone antibiotic—in the progression of AAD. Aortic transcriptome data were collected from GEO datasets to detect the genes and pathways expressed differently between healthy donors and AAD patients. Human primary Vascular Smooth Muscle Cells (VSMCs) were isolated from the aorta. After 72 h of exposure to 110ug/ml Ciprofloxacin or 100 nmol/L AngII, either or combined, the senescent cells were identified through SA-β-gal staining. MitoTracker staining was used to examine the morphology of mitochondria in each group. Cellular Reactive Oxygen Species (ROS) levels were measured using MitoSox and DCFH-DA staining. Western blot assay was performed to detect the protein expression level. We conducted an analysis of transcriptome data from both healthy donors and patients with AAD and found that there were significant changes in cellular senescence-related signaling pathways in the latter group. We then isolated and identified human primary VSMCs from healthy donors (control-VSMCs) and patients' (AAD-VSMCs) aortic tissue, respectively. We found that VSMCs from patients exhibited senescent phenotype as compared to control-VSMCs. The higher levels of p21 and p16 and elevated SA-β-gal activity demonstrated this. We also found that pretreatment with Ciprofloxacin promoted angiotensin-II-induced cellular senescence in control-VSMCs. This was evidenced by increased SA-β-gal activity, decreased cell proliferation, and elevation of p21 and p16 protein levels. Additionally, we found that Angiotensin-II (AngII) induced VSMC senescence by promoting ROS generation. We used DCFH-DA and mitoSOX staining to identify that Ciprofloxacin and AngII pretreatment further elevated ROS levels than the vehicle or alone group. Furthermore, JC-1 staining showed that mitochondrial membrane potential significantly declined in the Ciprofloxacin and AngII combination group compared to others. Compared to the other three groups, pretreatment of Ciprofloxacin plus AngII could further induce mitochondrial fission, demonstrated by mitoTracker staining and western blotting assay. Mechanistically, we found that Ciprofloxacin impaired the balance of mitochondrial fission and fusion dynamics in VSMCs by suppressing the phosphorylation of AMPK signaling. This caused mitochondrial dysfunction and ROS generation, thereby elevating AngII-induced cellular senescence. However, treatment with the AMPK activator partially alleviated those effects. Our data indicate that Ciprofloxacin may accelerate AngII-induced VSMC senescence through modulating AMPK/ROS signaling and, subsequently, hasten the progression of AAD.

Acteoside alleviates lipid peroxidation by enhancing Nrf2-mediated mitophagy to inhibit ferroptosis for neuroprotection in Parkinson's disease

Increasing evidence underscores the pivotal role of ferroptosis in Parkinson's Disease (PD) pathogenesis. Acteoside (ACT) has been reported to possess neuroprotective properties. However, the effects of ACT on ferroptosis and its molecular mechanisms remain unknown. This study aimed to explore whether ACT can regulate ferroptosis in dopaminergic (DA) neurons within both in vitro and in vivo PD models and to elucidate the underlying regulatory mechanisms. PD models were established and treated with various concentrations of ACT. Cell viability assays, Western blot, lipid peroxidation assessments, immunohistochemistry, and transmission electron microscopy were employed to confirm ACT's inhibition of ferroptosis and its protective effect on DA neurons across PD models. Immunofluorescence staining, MitoSOX staining, and confocal laser scanning microscopy further validated ACT's regulation regulatory effects on ferroptosis via the Nrf2-mitophagy pathway. Four animal behavioral tests were used to assess behavioral improvements in PD animals. ACT inhibited ferroptosis in PD models in vitro, as evidenced by increased cell viability, the upregulation of GPX4 and SLC7A11, reduced lipid peroxides, and attenuation of mitochondrial morphological alterations typical of ferroptosis. By activating the Nrf2-mitophagy axis, ACT enhanced mitochondrial integrity and reduced lipid peroxidation, mitigating ferroptosis. These in vitro results were consistent with in vivo findings, where ACT treatment significantly preserved DA neurons, curbed ferroptosis in these cells, and alleviated cognitive and behavioral deficits. This study is the first demonstration of ACT's capability to inhibit neuronal ferroptosis and protect DA neurons, thus alleviating behavioral and cognitive impairments in both in vitro and in vivo PD models. Furthermore, The suppression of ferroptosis by ACT is achieved through the activation of the Nrf2-mitophagy signaling pathway. Our results show that ACT is beneficial for both treating and preventing PD. They also offer novel therapeutic options for treating PD and molecular targets for regulating ferroptosis.

Cannabidiol and Beta-Caryophyllene Combination Attenuates Diabetic Neuropathy by Inhibiting NLRP3 Inflammasome/NFκB through the AMPK/sirT3/Nrf2 Axis.

In this study, we investigated in detail the role of cannabidiol (CBD), beta-caryophyllene (BC), or their combinations in diabetic peripheral neuropathy (DN). The key factors that contribute to DN include mitochondrial dysfunction, inflammation, and oxidative stress. Briefly, streptozotocin (STZ) (55 mg/kg) was injected intraperitoneally to induce DN in Sprague-Dawley rats, and we performed procedures involving Randall Sellito calipers, a Von Frey aesthesiometer, a hot plate, and cold plate methods to determine mechanical and thermal hyperalgesia in vivo. The blood flow to the nerves was assessed using a laser Doppler device. Schwann cells were exposed to high glucose (HG) at a dose of 30 mM to induce hyperglycemia and DCFDA, and JC1 and Mitosox staining were performed to determine mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides in vitro. The rats were administered BC (30 mg/kg), CBD (15 mg/kg), or combination via i.p. injections, while Schwann cells were treated with 3.65 µM CBD, 75 µM BC, or combination to assess their role in DN amelioration. Our results revealed that exposure to BC and CBD diminished HG-induced hyperglycemia in Schwann cells, in part by reducing mitochondrial membrane potential, reactive oxygen species, and mitochondrial superoxides. Furthermore, the BC and CBD combination treatment in vivo could prevent the deterioration of the mitochondrial quality control system by promoting autophagy and mitochondrial biogenesis while improving blood flow. CBD and BC treatments also reduced pain hypersensitivity to hyperalgesia and allodynia, with increased antioxidant and anti-inflammatory action in diabetic rats. These in vivo effects were attributed to significant upregulation of AMPK, sirT3, Nrf2, PINK1, PARKIN, LC3B, Beclin1, and TFAM functions, while downregulation of NLRP3 inflammasome, NFκB, COX2, and p62 activity was noted using Western blotting. the present study demonstrated that STZ and HG-induced oxidative and nitrosative stress play a crucial role in the pathogenesis of diabetic neuropathy. We find, for the first time, that a CBD and BC combination ameliorates DN by modulating the mitochondrial quality control system.

LncRNA SNHG1 enhances cartilage regeneration by modulating chondrogenic differentiation and angiogenesis potentials of JBMMSCs via mitochondrial function regulation

BackgroundCartilage is a kind of avascular tissue, and it is difficult to repair itself when it is damaged. In this study, we investigated the regulation of chondrogenic differentiation and vascular formation in human jaw bone marrow mesenchymal stem cells (h-JBMMSCs) by the long-chain noncoding RNA small nucleolar RNA host gene 1 (SNHG1) during cartilage tissue regeneration.MethodsJBMMSCs were isolated from the jaws via the adherent method. The effects of lncRNA SNHG1 on the chondrogenic differentiation of JBMMSCs in vitro were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR), Pellet experiment, Alcian blue staining, Masson’s trichrome staining, and modified Sirius red staining. RT-qPCR, matrix gel tube formation, and coculture experiments were used to determine the effect of lncRNA SNHG1 on the angiogenesis in JBMMSCs in vitro. A model of knee cartilage defects in New Zealand rabbits and a model of subcutaneous matrix rubber suppositories in nude mice were constructed for in vivo experiments. Changes in mitochondrial function were detected via RT-qPCR, dihydroethidium (DHE) staining, MitoSOX staining, tetramethyl rhodamine methyl ester (TMRM) staining, and adenosine triphosphate (ATP) detection. Western blotting was used to detect the phosphorylation level of signal transducer and activator of transcription 3 (STAT3).ResultsAlcian blue staining, Masson’s trichrome staining, and modified Sirius Red staining showed that lncRNA SNHG1 promoted chondrogenic differentiation. The lncRNA SNHG1 promoted angiogenesis in vitro and the formation of microvessels in vivo. The lncRNA SNHG1 promoted the repair and regeneration of rabbit knee cartilage tissue. Western blot and alcian blue staining showed that the JAK inhibitor reduced the increase of STAT3 phosphorylation level and staining deepening caused by SNHG1. Mitochondrial correlation analysis revealed that the lncRNA SNHG1 led to a decrease in reactive oxygen species (ROS) levels, an increase in mitochondrial membrane potential and an increase in ATP levels. Alcian blue staining showed that the ROS inhibitor significantly alleviated the decrease in blue fluorescence caused by SNHG1 knockdown.ConclusionsThe lncRNA SNHG1 promotes chondrogenic differentiation and angiogenesis of JBMMSCs. The lncRNA SNHG1 regulates the phosphorylation of STAT3, reduces the level of ROS, regulates mitochondrial energy metabolism, and ultimately promotes cartilage regeneration.

Mitochondrial biogenesis disorder and oxidative damage promote refractory apical periodontitis in rat and human.

To elucidate whether mitochondrial biogenesis disorder and damage from oxidative stress promote refractory apical periodontitis (RAP) in rat and human. Twenty Enterococcus faecalis-induced RAPs were established in the maxillary first molars of male Wistar rats. Concurrently, 12 periapical lesion specimens from patients presenting with RAP were obtained by apicoectomy. Radiographic examination and histologic analysis were conducted to evaluate periapical bone tissue destruction and morphological changes. The expression of key regulators of mitochondrial biogenesis, PGC-1α and Nrf2, were detected by immunohistochemistry and double immunofluorescence staining, Western blot and real-time PCR were also assayed. Mitochondrial ROS (mtROS) was identified by MitoSOX staining. Mitochondrial function was detected by the quantification of ATP production, mitochondrial DNA (mtDNA) copy number and activities of mitochondrial respiratory chain complexes. Furthermore, mitochondrial oxidative stress was evaluated by the determination of 3-nitrotyrosine (3-NT), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-deoxyguanosine (8-OHdG) expression levels, as well as malondialdehyde (MDA) expression and antioxidant capacity. Student's t-test was performed to determine significance between the groups; p < .05 was considered significant. In the maxilla, significantly more bone resorption, greater number of periapical apoptotic cells and Tartrate-resistant acid phosphatase (TRAP)-positive multinucleated cells were observed in the RAP group compared with the control group (p < .01). PGC-1α and Nrf2 were significantly reduced in rat and human RAP lesions compared to the control group (p < .01) at both the mRNA and protein levels. Double immunofluorescence analysis of PGC-1α or Nrf2 with TOMM20 also indicated that mitochondrial biogenesis was impaired in RAP group (p < .01). Additionally, mitochondrial dysfunction was observed in RAP group, as reflected by increased mtROS, decreased ATP production, reduced mtDNA copy number and complexes of the mitochondrial respiratory chain. Finally, the expression levels of mitochondrial oxidative stress markers, 3-NT, 4-HNE and 8-OHdG, were significantly increased in the RAP group (p < .01). Consistent with this, systemic oxidative damage was also present in the progression of RAP, including increased MDA expression and decreased antioxidant activity (p < .01). Mitochondrial biogenesis disorder and damage from oxidative stress contribute to the development of RAP.

Mitochondrial DNA release via the mitochondrial permeability transition pore activates the cGAS-STING pathway, exacerbating inflammation in acute Kawasaki disease

BackgroundKawasaki disease (KD) is an immune vasculitis of unknown origin, characterized by transient inflammation. The activation of the cGAS-STING pathway, triggered by mitochondrial DNA (mtDNA) release, has been implicated in the onset of KD. However, its specific role in the progression of inflammation during KD's acute phase remains unclear.MethodsWe measured mtDNA and 2’3’-cGAMP expression in KD patient serum using RT-qPCR and ELISA. A murine model of KD was induced by injecting Lactobacillus casei cell wall extract (LCWE), after which cGAS-STING pathway activation and inflammatory markers were assessed via immunohistochemistry, western blot, and RT-qPCR. Human umbilical vein endothelial cells (HUVECs) were treated with KD serum and modulators of the cGAS-STING pathway for comparative analysis. Mitochondrial function was evaluated using Mitosox staining, mPTP opening was quantified by fluorescence microscopy, and mitochondrial membrane potential (MMP) was determined with JC-1 staining.ResultsKD patient serum exhibited increased mtDNA and 2’3’-cGAMP expression, with elevated levels of pathway-related proteins and inflammatory markers observed in both in vivo and in vitro models. TEM confirmed mitochondrial damage, and further studies demonstrated that inhibition of mPTP opening reduced mtDNA release, abrogated cGAS-STING pathway activation, and mitigated inflammation.ConclusionThese findings indicate that mtDNA released through the mPTP is a critical activator of the cGAS-STING pathway, contributing significantly to KD-associated inflammation. Targeting mtDNA release or the cGAS-STING pathway may offer novel therapeutic approaches for KD management.

Prolonged Hypoxic Exposure Impairs Endothelial Functions: Possible Mechanism of HIF-1α Signaling

PURPOSE: Hypoxic training enhances oxygen availability by elevating hemoglobin, red blood cells, and capillaries. hypoxia-inducible factor (HIF) stabilization under hypoxic conditions triggers glycolysis, erythropoiesis, and angiogenesis. However, prolonged hypoxic exposure causes endothelial cell dysfunction, contributing to cardiovascular diseases. Furthermore, endothelial mitochondria play a crucial role in maintaining endothelial cell homeostasis through the processes of biogenesis, signaling cellular response, mitochondrial dynamics, and calcium homeostasis. However, the molecular response of endothelial mitochondria has not been fully elucidated. Therefore, this study aimed to investigate the endothelial mitochondria functions and morphological change in response to hypoxia.METHODS: Cobalt chloride and 2% hypoxic condition were applied to HUVECs. The endothelial cell functions were assessed using BrdU-based proliferation assay and scratch wound healing assays. Mitochondrial functions were evaluated using Mitosox and MitoTracker staining for mitochondrial reactive oxygen species (mtROS) and mitochondrial morphology analysis, respectively.RESULTS: The hypoxic condition (2% of O2) significantly decreased endothelial proliferation/migration and mitochondrial function. Furthermore, CoCl2 treatment increased the mtROS levels and mitochondrial fragmentation in HUVECs. Additionally, hypoxic conditions were found to regulate the phosphorylation of eNOS, mitochondrial biogenesis, mitophagy, and cell cycle-related protein expression.CONCLUSIONS: These results suggest that the HIF-α pathway leads to endothelial dysfunction via mitochondrial dysfunction. Further mechanistic studies will be needed to elucidate the cellular and molecular mechanisms by which hypoxic-response pathways influence the health and homeostasis of endothelial cells. The findings reported herein underscore the importance of strategies for hypoxic training to prevent cardiovascular diseases.

A simplified herbal decoction attenuates myocardial infarction by regulating macrophage metabolic reprogramming and phenotypic differentiation via modulation of the HIF-1α/PDK1 axis

BackgroundMyocardial infarction (MI) poses a global public health challenge, often associated with elevated mortality rates and a grim prognosis. A crucial aspect of the inflammatory injury and healing process post-MI involves the dynamic differentiation of macrophages. A promising strategy to alleviate myocardial damage after MI is by modulating the inflammatory response and orchestrating the shift from pro-inflammatory (M1) to anti-inflammatory (M2) macrophages, aiming to achieve a reduced M1/M2 ratio. Nuanxinkang (NXK), a simplified herbal decoction, has demonstrated noteworthy cardioprotective, inflammation-regulating, and myocardial energy metabolism-regulating properties.MethodsIn this study, we constructed an MI model by ligating coronary arteries to investigate the efficacy of NXK in improving ventricular remodeling and cardiac function. Mice were administered NXK (1.65 g/kg/d) or an equivalent volume of regular saline via gavage for 28 consecutive days, commencing the day after surgery. Then, we conducted echocardiography to assess the cardiac function, Masson staining to illustrate the extent of myocardial fibrosis, TUNEL staining to reveal myocardial apoptosis, and flow cytometry to analyze the polarization of M1 and M2 macrophages in the hearts. Besides, a lipopolysaccharide (LPS)-induced pro-inflammatory macrophage (M1) polarization model was implemented in RAW264.7 cells to elucidate the underlying mechanism of NXK in regulating macrophage polarization. RAW264.7 cells were pre-treated with or without NXK-containing serum. Oxidative stress was detected by MitoSox staining, followed by Seahorse energy metabolism assay to evaluate alterations in mitochondrial metabolic patterns and ATP production. Both In vivo and in vitro, HIF-1α and PDK1 were detected by fluorescent quantitative PCR and Western blotting.ResultsIn vivo, MI mice exhibited a decline in cardiac function, adverse ventricular remodeling, and an increase in glycolysis, coupled with M1-dominant polarization mediated by the HIF-1α/PDK1 axis. Notably, robust responses were evident with high-dose NXK treatment (1.65 g/kg/day), leading to a significant enhancement in cardiac function, inhibition of cardiac remodeling, and partial suppression of macrophage glycolysis and the inflammatory phenotype in MI mice. This effect was achieved through the modulation of the HIF-1α/PDK1 axis. In vitro, elevated levels of mitochondrial ROS production and glycolysis were observed in LPS-induced macrophages. Conversely, treatment with NXK notably reduced the oxidative stress damage induced by LPS and enhanced oxidative phosphorylation (OXPHOS). Furthermore, NXK demonstrated the ability to modify the energy metabolism and inflammatory characteristics of macrophages by modulating the HIF-1α/PDK1 axis. The influence of NXK on this axis was partially counteracted by the HIF-1α agonist DMOG. And NXK downregulated PDK1 expression, curtailed glycolysis, and reversed LPS-induced M1 polarization in macrophages, similar to the PDK1 inhibitor DCA.ConclusionIn conclusion, NXK protects against MI-induced cardiac remodeling by inducing metabolic reprogramming and phenotypic differentiation of macrophages, achieved through the modulation of the HIF-1α/PDK1 axis. This provides a novel and promising strategy for the treatment of MI.

Cordycepin Enhanced Therapeutic Potential of Gemcitabine against Cholangiocarcinoma via Downregulating Cancer Stem-Like Properties.

Cordycepin, a valuable bioactive component isolated from Cordyceps militaris, has been reported to possess anti-cancer potential and the property to enhance the effects of chemotherapeutic agents in various types of cancers. However, the ability of cordycepin to chemosensitize cholangiocarcinoma (CCA) cells to gemcitabine has not yet been evaluated. The current study was performed to evaluate the above, and the mechanisms associated with it. The study analyzed the effects of cordycepin in combination with gemcitabine on the cancer stem-like properties of the CCA SNU478 cell line, including its anti-apoptotic, migratory, and antioxidant effects. In addition, the combination of cordycepin and gemcitabine was evaluated in the CCA xenograft model. The cordycepin treatment significantly decreased SNU478 cell viability and, in combination with gemcitabine, additively reduced cell viability. The cordycepin and gemcitabine co-treatment significantly increased the Annexin V+ population and downregulated B-cell lymphoma 2 (Bcl-2) expression, suggesting that the decreased cell viability in the cordycepin+gemcitabine group may result from an increase in apoptotic death. In addition, the cordycepin and gemcitabine co-treatment significantly reduced the migratory ability of SNU478 cells in the wound healing and trans-well migration assays. It was observed that the cordycepin and gemcitabine cotreatment reduced the CD44highCD133high population in SNU478 cells and the expression level of sex determining region Y-box 2 (Sox-2), indicating the downregulation of the cancer stem-like population. Cordycepin also enhanced oxidative damage mediated by gemcitabine in MitoSOX staining associated with the upregulated Kelch like ECH Associated Protein 1 (Keap1)/nuclear factor erythroid 2-related factor 2 (Nrf2) expression ratio. In the SNU478 xenograft model, co-administration of cordycepin and gemcitabine additively delayed tumor growth. These results indicate that cordycepin potentiates the chemotherapeutic property of gemcitabine against CCA, which results from the downregulation of its cancer-stem-like properties. Hence, the combination therapy of cordycepin and gemcitabine may be a promising therapeutic strategy in the treatment of CCA.