Reperfusion Injury Research Articles

Mangiferin Attenuates Myocardial Ischemia Reperfusion Injury by Regulating the GAS6/Axl Signaling Pathway.

Ischemia reperfusion-induced myocardial injury is a prominent pathological feature in patients with coronary artery disease, contributing to significant mortality and morbidity rates. Mangiferin (MGF), the main active ingredient extracted from Anemarrhena asphodeloides Bge, has anti-inflammatory, anti-oxidation, anti-diabetes, and anti-tumor effects. The present study confirmed that the GAS6/Axl pathway was identified as a promising novel target for the treatment of myocardial ischemia reperfusion (IR) injury. However, whether MGF exerts anti-myocardial ischemia reperfusion injury through GAS6/Axl is still unclear. In this study, BALB/c male mice and HL-1 cardiomyocytes were used to construct a model of IR and hypoxia-reoxygenation (HR) (or H2O2) injury invivo and invitro, respectively. MGF significantly improved cardiac function indicators, myocardial structure, myocardial enzymes, and mitochondrial function, together with reduced oxidative stress and apoptosis in IR-injured mice. Invitro, MGF significantly increased cell viability, inhibited the release of LDH, reduced oxidative stress and apoptosis, and improved mitochondrial function in both HR and H2O2-injured HL-1 cells. In particular, the GAS6/Axl signaling pathway plays an important role in this process. Additionally, we also demonstrated that GAS6 gene knockout reversed the protective effect of MGF against HR and H2O2-injured cardiomyocytes. The present study confirmed that MGF has protective effects against myocardial IR injury by activating the GAS6/Axl pathway, providing a theoretical basis for MGF as a potential cardioprotective drug in the clinical setting of myocardial IR injury.

Arachidonic acid synergizes with aspirin preventing myocardial ischemia-reperfusion injury and mitigates bleeding risk.

The therapeutic efficacy of coronary revascularization is compromised by myocardial ischemia-reperfusion (MI/R) injury. Higher levels of circulating arachidonic acid (AA) are reportedly associated with lower risk of cardiovascular disease. The cyclooxygenase (COX) pathway metabolizes AA into prostaglandins (PGs) and the platelet-activating thromboxane A2 (TXA2), which is inhibited by aspirin. We aimed to explore whether AA or its combination with aspirin modulates MI/R injury and aspirin-caused gastric bleeding. Mice were subjected to 30min coronary artery ligation followed by reperfusion. AA reduced MI/R injury in mice, and its combination with aspirin provided further cardioprotection. Aspirin inhibited MI/R-triggered platelet activation and ameliorated microvascular obstruction immediately upon reperfusion, whereas AA improved microvascular perfusion at a later stage of reperfusion, coinciding with increased coronary vasodilatation. Co-administration of AA and aspirin markedly reduced cardiac neutrophil infiltration and vascular permeability and improved microcirculation. AA increased urinary metabolites of PGI2 and PGE2, not TXA2, and this selective augmentation was further enhanced by co-treatment with aspirin. Elevation in PGI2 and PGE2 correlated with reduced infarction and improved ventricular function, and inhibiting COX-2 attenuated the synergistic cadioprotection. Furthermore, oral administration of AA with aspirin after reperfusion provided a maximal cardioprotection and abolished aspirin-caused gastric bleeding. AA synergizes with aspirin in protecting against MI/R injury, while minimizing the related bleeding risk, a major concern for patients with acute myocardial infarction. This is attributable to the selective augmentation of PGI2 and PGE2 that is amplified by TXA2 suppression by aspirin, underscoring improved microcirculation and ameliorated inflammation.

Protective mechanism of safflower yellow injection on myocardial ischemia-reperfusion injury in rats by activating NLRP3 inflammasome

ObjectivesThis study intended to explore whether the protective effect safflower yellow injection (SYI) on myocardial ischemia-reperfusion (I/R) injury in rats mediated of the NLRP3 inflammasome signaling.MethodsThe I/R model was prepared by ligating the left anterior descending coronary artery for 45 min and then releasing the blood flow for 150 min. 96 male Wistar rats were randomly divided into sham group, I/R group, Hebeishuang group (HBS), SYI high-dose group (I/R + SYI-H), SYI medium-dose group (I/R + SYI-M) and SYI low-dose group (I/R + SYI-L). Cell experiments were divided into normal control group (NC), Oxygen glucose deprivation/reoxygenation group (OGD/R), OGD/R + SYI group, OGD/R + SYI + Chloroquine group (OGD/R + SYI + CQ). The area of myocardial ischemia infarction and pathological changes were observed by the Tetrazolium method (TTC) and HE staining. Myocardial enzymes such as aspartate aminotransferase (AST), lactate dehydrogenase (LDH) and creatine kinase (CK) were measured by chemiluminescence (CL) method. The inflammatory factors levels of TNF-α, IL-1β, MCP-1, and IL-6 were detected by ELISA. The expressions of inflammatory-related proteins (Caspase-1, NLRP3, TLR4, NF-κB), autophagosome-related proteins (LC3-I, LC3-II,LC3-II/LC3-I), apoptosis-related proteins (Bax, Bcl-2, Caspase-3, Bcl-2/Bax) and autophagy-related proteins (p62/SQSTM1, PI3K, p-Akt, mTOR) were detected by Western-Blot. Cell morphology and cell viability were detected by transmission electron microscopy and CCK-8.ResultsIn vivo, compared with sham group, the percentage of myocardial infarction area was increased and myocardial tissue arrangement was disordered in I/R group. In addition, the activities of myocardial enzymes, the contents of inflammatory factors, the expressions of inflammatory-related proteins, autophagy-related proteins, autophagosome-related proteins, Bax and Caspase-3 were increased, while Bcl-2 and Bcl-2/Bax were decreased. SYI treatment reversed these trends, except for the expression of autophagosome-related proteins. In vitro, SYI decreased the contents of inflammatory factors and the expressions of inflammatory-related proteins, autophagy-related proteins and autophagosome-related proteins caused by OGD/R. However, the contents of inflammatory factors and the expression of inflammatory-related proteins, p62/SQSTM1 and mTOR were increased, while PI3K, p-AKT, LC3-II/LC3-I were significantly decreased in OGD/R + SYI + CQ group.ConclusionsSYI can promote myocardial tissue autophagy by regulating NLRP3, thereby attenuating the myocardial inflammatory response and protecting damaged myocardium in I/R rats.

SNHG16 alleviates pulmonary ischemia-reperfusion injury by promoting the warburg effect through regulating MTCH2 expression: experimental studies.

Pulmonary ischemia-reperfusion injury (PIRI) is a major cause of fatality post-lung transplantation. Though some long non-coding RNAs (lncRNAs) have been studied in acute lung injury (ALI), their effects on PIRI remain undefined. The present study aims to explore the underlying mechanism of small nucleolar RNA host gene 16 (SNHG16) in PIRI. PIR mouse and OGD/R cell models were established. Exosomes were extracted from human pulmonary microvascular endothelial cells (HPMECs). Functional and rescue experiments were conducted in OGD/R-exposed HPMECs, OGD/R-exposed pulmonary alveolar epithelial type II cells (AECs), and I/R model mice. The relationships among SNHG16, miR-372-3p/miR-373-3p, and MTCH2 were also verified using dual luciferase reporter assay, RNA pull-down and RIP assay. SNHG16 was downregulated in OGD/R-exposed HPMECs, and SNHG16 overexpression accelerated proliferation, angiogenesis, and ameliorated mitochondrial respiration in OGD/R-exposed HPMECs. HPMEC-derived exosomal SNHG16 suppressed OGD/R-induced type II AEC injury. SNHG16 ameliorated lung injury in PIR mice. Mechanistically, SNHG16 targeted and negatively regulated miR-372-3p and miR-373-3p expression, and MTCH2, a target gene of miR-372-3p/miR-373-3p. SNHG16 was found to upregulate MTCH2 expression not only in a miR-372-3p and miR-373-3p-dependent manner but also suppress ubiquitination induced MTCH2 degradation. Our findings revealed that SNHG16 overexpression suppressed OGD/R-induced HPMEC apoptosis by promoting Warburg effect, and HPMEC-derived exosomal SNHG16 alleviated PIRI through the miR-372-3p/miR-373-3p/MTCH2 axis, suggesting that SNHG16 as a therapeutic target for PIRI.

Exploring Potential Complement Modulation Strategies for Ischemia–Reperfusion Injury in Kidney Transplantation

Exploring Potential Complement Modulation Strategies for Ischemia–Reperfusion Injury in Kidney Transplantation

Inhibition of HIF-prolyl hydroxylase promotes renal tubule regeneration via the reprogramming of renal proximal tubular cells.

The ability of the mammalian kidney to repair or regenerate after acute kidney injury (AKI) is very limited. The maladaptive repair of AKI promotes progression to chronic kidney disease (CKD). Therefore, new strategies to promote the repair/regeneration of injured renal tubules after AKI are urgently needed. Hypoxia has been shown to induce heart regeneration in adult mice. However, it is unknown whether hypoxia can induce kidney regeneration after AKI. In this study, we used a prolyl hydroxylase domain inhibitor (PHDI), MK-8617, to mimic hypoxic conditions and found that MK-8617 significantly ameliorated ischemia reperfusion injury (IRI)-induced AKI. We also showed that MK-8617 dramatically facilitated renal tubule regeneration by promoting the proliferation of renal proximal tubular cells (RPTCs) after IRI-induced AKI. We then performed bulk mRNA sequencing and discovered that multiple nephrogenesis-related genes were significantly upregulated with MK-8617 pretreatment. We also showed that MK-8617 may alleviate proximal tubule injury by stabilizing the HIF-1α protein specifically in renal proximal tubular cells. Furthermore, we demonstrated that MK-8617 promotes the reprogramming of renal proximal tubular cells to Sox9+ renal progenitor cells and the regeneration of renal proximal tubules. In summary, we report that the inhibition of prolyl hydroxylase improves renal proximal tubule regeneration after IRI-induced AKI by promoting the reprogramming of renal proximal tubular cells to Sox9+ renal progenitor cells.

Bundling Care in Comatose Post Cardiac Arrest Patients

Post cardiac arrest syndrome (PCAS), an inflammatory state resulting from an ischemia-reperfusion injury impacting multiple organ systems. Hospital teams from the ED to Cath Labs to the ICU must practice in synchrony to optimize care. Key priorities in patients who remain comatose following return of spontaneous circulation are imperative to reduce the impact of PCAS. The team must focus on interventions and coordinated care to limit the damage of reperfusion injury to the brain/body. The complexity and heterogeneity of this patient population presents the team with challenges related to time, place, intervention sequence and elements. This presentation will focus on delivering care to the cardiac arrest and comatose post-cardiac arrest patient, selecting interventions maximizing oxygenation/ventilation and hemodynamics while implementing the strategies of TTM, Neurologic care, seizure surveillance, and management to lessen the pathologic impact of PCAS in the form of bundles of care. Target goals, interventions, and outcomes for the bundle elements will be shared.

Lidocaine Alleviates Myocardial Ischemia-Reperfusion Injury in Rats through JNK Signaling Pathway

Lidocaine Alleviates Myocardial Ischemia-Reperfusion Injury in Rats through JNK Signaling Pathway

ProBDNF as a Myokine in Skeletal Muscle Injury: Role in Inflammation and Potential for Therapeutic Modulation of p75NTR

Brain-derived neurotropic factor (BDNF) is expressed by skeletal muscle as a myokine. Our previous work showed that the active precursor, proBDNF, is the predominant form of BDNF expressed in skeletal muscle, and that following skeletal muscle injury, proBDNF levels are significantly increased. However, the function of the muscle-derived proBDNF in injury-induced inflammation has yet to be fully understood. Using a model of tourniquet-induced ischemia–reperfusion (IR) injury of the hindlimb, this study presents, for the first time, strong and novel evidence that following IR injury, proBDNF is released from skeletal muscle into circulation as an endocrine signaling molecule. Further, this study shows that 1 day post-IR injury, the proBDNF receptor, p75NTR, is upregulated 12-fold in splenic monocytes, which are known to be quickly mobilized to the injury site. We demonstrate that p75NTR plays a role in the activation of splenic monocytes, and that treatment with a p75NTR small-molecule modulator, LM11A-31, significantly reduced monocyte inflammatory responses upon lipopolysaccharide stimulation. Overall, the present study establishes proBDNF as a myokine that plays a significant role in skeletal muscle injury-induced inflammation through its receptor, p75NTR, which may be modulated using LM11A-31 as potential translational therapeutic against injury and inflammation.

Novel Selective Cardiac Myosin-Targeted Inhibitors Alleviate Myocardial Ischaemia–Reperfusion Injury

Abstract Purpose Reperfusion of the ischaemic heart is essential to limit myocardial infarction. However, reperfusion can cause cardiomyocyte hypercontracture. Recently, cardiac myosin-targeted inhibitors (CMIs), such as Mavacamten (MYK-461) and Aficamten (CK-274), have been developed to treat patients with cardiac hypercontractility. These CMIs are well tolerated and safe in clinical trials. We hypothesised that, by limiting hypercontraction, CMIs may reduce hypercontracture and protect hearts in the setting of ischaemia and reperfusion (IR). Methods We investigated the ability of MYK-461 and CK-274 to inhibit hypercontracture of adult rat cardiomyocytes (ARVC) in vitro following ATP depletion. A suitable dose of CMIs for subsequent in vivo IR studies was identified using cardiac echocardiography of healthy male Sprague Dawley rats. Rats were anaesthetized and subject to coronary artery ligation for 30 min followed by 2 h of reperfusion. Prior to reperfusion, CMI or vehicle was administered intraperitoneally. Ischaemic preconditioning (IPC) was used as a positive control group. Infarct size was assessed by tetrazolium chloride staining and extent of hypercontracture was assessed by histological staining. Results Treatment with CMIs inhibited ARVC hypercontracture in vitro. MYK-461 (2 mg/kg) and CK-274 (0.5 mg/kg to 2 mg/kg) significantly reduced infarct size vs. vehicle. IR caused extensive contraction band necrosis, which was reduced significantly by IPC but not by CMIs, likely due to assay limitations. GDC-0326, an inhibitor of PI3Kα, abrogated CK-274-mediated protection following IR injury. GDC-0326 reduced phosphorylation of AKT when administered together with CK-274. Conclusion This study identifies CMIs as novel cardioprotective agents in the setting of IR injury.

Identifying Pyroptosis-Hub Genes and Inflammation Cell Type-Related Genes in Ischemic Stroke.

Stroke is the second-leading global cause of death. The damage attributed to the immune storm triggered by ischemia-reperfusion injury (IRI) post-stroke is substantial. However, data on the transcriptomic dynamics of pyroptosis in IRI are limited. This study aimed to analyze the expression of key pyroptosis genes in stroke and their correlation with immune infiltration. Pyroptosis-related genes were identified from the obtained middle cerebral artery occlusion (MCAO) datasets. Differential expression and functional analyses of pyroptosis-related genes were performed, and differences in functional enrichment between high-risk and low-risk groups were determined. An MCAO diagnostic model was constructed and validated using selected pyroptosis-related genes with differential expression. High- and low-risk MCAO groups were constructed for expression and immune cell correlation analysis with pyroptosis-related hub genes. A regulatory network between pyroptosis-related hub genes and miRNA was also constructed, and protein domains were predicted. The expression of key pyroptosis genes was validated using an MCAO rat model. Twenty-five pyroptosis genes showed differential expression, including four hub genes, namely WISP2, MELK, SDF2L1, and AURKB. Characteristic genes were verified using real-time quantitative PCR analyses. The high- and low-risk groups showed significant expression differences for WISP2, MELK, and SDF2L1. In immune infiltration analysis, 12 immune cells showed differences in expression in MCAO samples. Further analysis demonstrated significant positive correlations between the pyroptosis-related hub gene SDF2L1 and immune cell-activated dendritic cells in the high-risk group and immune cell natural killer cells in the low-risk group. This study identified four pyroptosis-related hub genes, with elevated WISP2, MELK, and SDF2L1 expression closely associated with the high-risk group. The analysis of inflammatory cell types in immune infiltration can predict ischemic stroke risk levels and help to facilitate treatment.

Inhibition of CCR2 attenuates NLRP3-dependent pyroptosis after myocardial ischaemia-reperfusion in rats via the NF-kB pathway.

Myocardial infarction (MI) is a leading cause of mortality worldwide, contributing significantly to long-term cardiac dysfunction and heart failure. Effective therapeutic strategies are urgently needed to mitigate the extensive damage caused by MI and subsequent ischemia-reperfusion (I/R) injury. This study investigates the role of the Chemokine receptor 2 (CCR2) in regulating NLRP3-dependent cardiomyocyte pyroptosis following myocardial ischemia-reperfusion (MIR), elucidating its molecular mechanisms. A myocardial ischemia-reperfusion model was established using 124 Sprague-Dawley rats by ligating the left coronary artery, inducing 30min of ischemia. Following ischemia, RS504393, a selective CCR2 antagonist, was administered intraperitoneally one hour after reperfusion. To further explore the underlying mechanisms, the NF-κB pathway agonist Phorbol 12-myristate 13-acetate (PMA) was administered 1h post-MIR. The results showed a marked increase in CCR2 expression in the heart, peaking on the first day of reperfusion. Treatment with RS504393 significantly improved short-term cardiac function and reduced myocardial infarction size, decreased myocardial pyroptosis and suppressed the expression of NLRP3, GSDMD, Caspase-1, IL-1β, and IL-18 through inhibition of the NF-κB signaling pathway. This effect was reversed with the administration of PMA. In summary, the inhibition of CCR2 shows potential in mitigating myocardial injury following MIR by modulating the NF-κB signaling pathway. These findings highlight CCR2 as a promising therapeutic target for myocardial ischemia-reperfusion injury.

MMP-2 inhibition attenuates ER stress-mediated cell death during myocardial ischemia-reperfusion injury by preserving IRE1α

Endoplasmic reticulum (ER) stress is one of the major events accompanying myocardial ischemia-reperfusion (IR) injury, as hypoxia and oxidative stress disrupt protein folding in the ER. As a result, the unfolded protein response (UPR) is activated through different sensors including inositol-requiring enzyme 1α (IRE1α) and protein kinase R-like ER kinase (PERK). Failure of the UPR to reduce ER stress induces cellular dysfunction. Matrix metalloproteinase-2 (MMP-2) is a ubiquitous protease that is activated intracellularly in response to oxidative stress and partially localizes near the ER. However, its role in ER homeostasis is unknown. We hypothesized that MMP-2 is involved in the regulation of the UPR and ER stress-mediated apoptosis during IR injury. Isolated mouse hearts subjected to IR injury showed impaired recovery of post-ischemic contractile function compared to aerobically perfused controls. Ventricular extracts from IR hearts had higher levels of glucose-regulated protein-78 and protein disulfide isomerase and lower levels of IRE1α and PERK compared to aerobic controls. MMP-2 inhibitors, ARP-100 or ONO-4817, given 10 min before ischemia, improved cardiac post-ischemic recovery and preserved IRE1α level in hearts subjected to 30 min ischemia/40 min reperfusion. IR also increased the levels of CHOP and mitochondrial Bax and caspase-3 and -9 activities, indicating induction of apoptosis, all of which were attenuated by MMP-2 inhibitors, regardless of the reperfusion time. Immunoprecipitation showed an association between MMP-2 and IRE1α in aerobic and IR hearts. During myocardial IR injury MMP-2 may impair the UPR and induce apoptosis by proteolysis of IRE1α. Inhibition of MMP-2 activity protects against cardiac contractile dysfunction in part by preserving IRE1α and preventing the progression to myocardial cell death.

Integrated Analysis and Validation of Ferroptosis-Related Genes Associated with Ischemia/Reperfusion Injury in Lung Transplantation.

Lung transplantation is the only effective therapeutic option for patients with end-stage lung disease. However, ischemia/reperfusion injury (IRI) during transplantation is a leading cause of primary graft dysfunction (PGD). Ferroptosis, a form of iron-dependent cell death driven by lipid peroxidation, has been implicated in IRI across various organs. This study aims to explore the role of ferroptosis in lung transplantation-related ischemia/reperfusion injury and to identify its potential molecular mechanisms through bioinformatics analysis. Transcriptome data from lung transplant patients were obtained from the Gene Expression Omnibus (GEO) database. Ferroptosis-related differentially expressed genes (FRGs) were identified by analyzing gene expression profiles before and after reperfusion. Weighted gene co-expression network analysis (WGCNA) was used to identify module genes, and overlapping genes were further analyzed using two machine learning algorithms. The CIBERSORT algorithm was applied to assess immune cell infiltration, while Mendelian randomization (MR) analysis was used to investigate causal relationships between candidate genes and PGD. Finally, Consensus clustering based on FRGs was performed to identify subtypes. We identified four candidate genes associated with ferroptosis during lung reperfusion: tumor necrosis factor alpha-induced protein 3 (TNFAIP3), C-X-C motif chemokine ligand 2 (CXCL2), neural precursor cell expressed developmentally down-regulated 4-like (NEDD4L), and sestrin 2 (SESN2). These genes were closely associated with immune cell infiltration. MR analysis suggested that SESN2 might play a protective role against PGD. Additionally, consensus clustering revealed distinct immune infiltration patterns across subtypes, providing insights for personalized therapeutic approaches to lung ischemia/reperfusion injury (LIRI). This study highlights TNFAIP3, CXCL2, NEDD4L, and SESN2 as candidate genes associated with ferroptosis during LIRI, with SESN2 potentially protecting against PGD. These findings offer promising therapeutic targets for preventing LIRI and improving outcomes in lung transplantation.

Electroacupuncture inhibits neuronal pyroptosis in ischemic brain injury through modulating SIRT5-mediated NEK7 succinylation.

Ischemic stroke is a leading cause of global death. The treatment of this disease can inevitably result in reperfusion, thereby triggering cerebral ischemia-reperfusion injury (IRI) and neuronal pyroptosis. Electroacupuncture derived from traditional acupuncture has been proven to have favorable effects on ameliorating brain IRI and pyroptosis. Hence, the goal of the current research was to elucidate the mechanism governing electroacupuncture in cerebral IRI. We employed middle cerebral artery occlusion (MCAO) model to induce brain IRI. Our results revealed that electroacupuncture attenuated IRI in MCAO mice by minishing brain damage and hindering neuronal pyroptosis. Strikingly, it was discovered that electroacupuncture provoked the decrease of succinylation level and enhanced expression of SIRT5. Then, we demonstrated that knockdown of SIRT5 reversed the role of electroacupuncture in cerebral infarct injury and pyroptosis. In terms of mechanism, SIRT5 impeded the succinylation modification of NEK7 at K81 site to downregulate its expression level. Eventually, overexpression of NEK7 abrogated the impacts of electroacupuncture on MCAO mice. In conclusion, this study provided the compelling evidence that electroacupuncture restrained neuronal pyroptosis to mitigate ischemic brain damage via desuccinylating NEK7 in a SIRT5-dependent manner.

Paraoxonase 1 ameliorates neurological symptoms and motor coordination impairment caused by cerebral ischemia-reperfusion injury.

The anti-atherosclerotic effects of high-density lipoprotein (HDL) prevent the onset of cerebral infarction and provide cerebroprotective effects against ischemia-reperfusion injury. These inhibitory effects have been attributed to its antioxidant, anti-inflammatory, and antithrombotic properties. However, pharmacotherapeutic strategies to clinically realize these effects have not been demonstrated. Therefore, we aimed to develop paraoxonase 1 (PON1), a hydrolytic enzyme associated with HDL that exhibits antioxidant and anti-inflammatory effects, as a novel therapeutic agent against ischemia-reperfusion injury in cerebral infarction. We established a method to extract PON1 from human plasma with high purity and recovery while maintaining its activity. The purified PON1 exhibited antioxidant activity against human-derived LDL and HDL. Furthermore, PON1 actively suppressed the oxidation chain reaction by hydrolyzing lipid peroxides. The HDL-binding ability of PON1 was evaluated based on its activity in fractionated HDL from mice administered PON1 intravenously, which showed that most intravenously administered PON1 specifically bound to HDL. The cerebroprotective effect of intravenously administered PON1 was assessed using a mouse middle cerebral artery ischemia-reperfusion model by measuring infarct volume, long-term neurological scores, and walking time on a rotarod. Administration of PON1 after reperfusion reduced infarct volume 24 h after ischemia-reperfusion. Additionally, daily administration of PON1 for three days significantly improved neurological scores and walking time by approximately one month. Analysis of gene arrays in brain tissue indicated that PON1 suppresses biological functions and pathways associated with oxidative stress, inflammation, vascular dysfunction, thrombosis, and fibrosis. PON1 enhances the cerebroprotective effects of HDL and is a potential candidate for acute stroke therapy.

FTO Alleviates Hepatic Ischemia-Reperfusion Injury by Regulating Apoptosis and Autophagy.

Objective: Despite N6-methyladenosine (m6A) being closely involved in various pathophysiological processes, its potential role in liver injury is largely unknown. We designed the current research to study the potential role of fat mass and obesity-associated protein (FTO), an m6A demethylase, on hepatic ischemia-reperfusion injury (IRI). Methods: Wild-type mice injected with an adeno-associated virus carrying fat mass and obesity-associated protein (AAV-FTO) or adeno-associated virus carrying green fluorescent protein (GFP) (AAV-GFP) were subjected to a hepatic IRI model in vivo. Hematoxylin-eosin staining was performed to observe IRI. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining was used to observe the cell apoptosis. Reverse transcription polymerase chain reaction (RT-PCR) was used to observe the expression of FTO. The protein levels of FTO, apoptosis, or autophagy-associated signaling proteins were detected by western blot. Reactive oxygen species (ROS) levels were determined by flow cytometry, and immunohistochemistry was used to detect the FTO and LC3-II expression. For in vitro experiments, cultured hepatocytes were subjected to hypoxia/reoxygenation (H/R) stimulation. Monodansylcadaverine (MDC) staining was used to visualize autophagic vesicles. Results: In the present study, we showed that FTO was involved in hepatic IRI, apoptosis, and autophagy. Specifically, the expression level of FTO was significantly reduced in the hepatic IRI. Besides, increasing FTO expression (AAV-FTO) ameliorated the hepatic IRI in animal models, accompanied by decreased apoptosis and autophagy. Furthermore, the FTO inhibitor (FB23-2) aggravated autophagy in hepatocytes upon H/R-induced damage. Conclusion: FTO could act as a protective effector during hepatic IRI, associated with decreased apoptosis and autophagy. FTO-mediated m6A demethylation modification may be an important therapeutic target for hepatic IRI.

Exosome Loaded in Microneedle Patch Ameliorates Renal Ischemia–Reperfusion Injury in a Mouse Model

Introduction: Renal dysfunction due to ischemia–reperfusion injury (IRI) is a common problem after kidney transplantation. In recent years, studies on animal models have shown that exosomes derived from mesenchymal stem cells (MSC‐Exo) play an important role in treating acute kidney injury (AKI) and promoting tissue repair. The microneedle patch provides a noninvasive and targeted delivery system for exosomes. The purpose of this innovative approach is to combine MSC‐Exo with microneedle patches.Method: Exosomes were isolated from MSCs, characterized, and placed in the prepared microneedle patch. Then this construct was applied to the IRI mice model. After 7 days, the gene expression of miR‐34a and its targets B‐cell lymphoma‐2 (BCL‐2) and BCL‐2‐associated X (BAX), along with reactive oxygen species (ROS) and lipid peroxidation (LPO) production, was investigated. Additionally, renoprotection was evaluated for measuring blood urea nitrogen (BUN) and creatinine (Cr) and histopathology detection.Results: After using microneedle patches containing exosomes, the reduction of miR‐34a and BAX and enhancement of BCL‐2 were observed. Moreover, treatment by this construct decreased the production of ROS, LPO, BUN, and Cr and improved tissue damage.Conclusion: The use of a microneedle patch containing exosomes is a noninvasive method that enables the release of exosomes in a slow manner. In comparison to exosome injection alone, microneedle patch‐exosome treatment offers a longer and more targeted effect that improves renal IRI dysfunction and reduces tissue damage, potentially facilitating the clinical application of exosomes and improving graft survival.

Dihydrotanshinone I improves cardiac function by promoting lymphangiogenesis after myocardial ischemia-reperfusion injury.

Dihydrotanshinone I (DHT) is an active ingredient derived from Salvia miltiorrhiza. Previous studies have demonstrated that DHT can improve cardiac function in rats with myocardial ischemia-reperfusion injury (IR). However, the mechanism by which DHT improves myocardial injury in rats still requires further research. Lymphangiogenesis can reduce myocardial edema, inflammation, and fibrosis after myocardial infarction in rats, and improve cardiac function. In this study, the changes in cardiac functions, collagen fiber deposition in the infarcted area and the level of relevant indicators of lymphangiogenesis were examined by echocardiography, Masson's trichrome staining, immunohistochemistry and Western blot, respectively. Human lymphatic endothelial cells (HLECs) were transfected with siVE-cadherin and siVEGFR-3, and the effects of DHT on HLEC cell viability, migration and tube formation were detected through CCK8, TUNEL, transwell, wound healing and tube formation assay. We found that in myocardial IR rats treated with DHT, the levels of LYVE-1, PROX1, VEGF-C, VEGFR-3, IGF-1, podoplanin and IGF-1R, which are associated with lymphangiogenesis, were increased, as well as the level of VE-cadherin, which maintains endothelial cell function. DHT reduced the levels of inflammatory factors and myocardial cell apoptosis, thereby improving cardiac function after I/R. To explore the mechanism of DHT promoting lymphangiogenesis, H2O2 and OGD/R injury models of HLECs were constructed to simulate the microenvironment of myocardial IR in vitro. The results proved that DHT could reduce the damage and apoptosis of HLECs. On the other hand, DHT enhanced the expression of VEGFR-3 and VE-cadherin in HLECs, promoted cell migration and tube formation. The effects of DHT on the tube formation and migration of HLECs were significantly decreased after knocking down VEGFR-3 or VE-cadherin. Our research proposed that DHT could improve the heart function after IR through the enhancement of lymphangiogenesis and contributed to the development of the treatment methods for myocardial IR.

Potential Signal Pathways and Therapeutic Effects of Mesenchymal Stem Cell on Oxidative Stress in Diseases.

Oxidative stress is a biological stress response produced by the destruction of redox equilibrium in aerobic metabolism in organisms, which is closely related to the occurrence of many diseases. Mesenchymal stem cells (MSCs) have been found to improve oxidative stress injury in a variety of diseases, including arthritis, chronic obstructive pulmonary disease, asthma, multiple sclerosis, focal segmental glomerulosclerosis, diabetic nephropathy, ischemia-reperfusion injury, hepatic fibrosis, myocardial infarction, diabetes, inflammatory bowel disease, etc. The antioxidant stress capacity of MSCs may be a breakthrough in the treatment of these diseases. This review found that MSCs have the ability to resist oxidative stress, which may be achieved through MSCs involvement in mediating the Nrf2, MAPK, NF-κB, AMPK, PI3K/AKT and Wnt/b-catenin signaling pathways.