Ischemia Reperfusion Research Articles

Renoprotective Effects of Daprodustat in Patients with Chronic Kidney Disease and Renal Anemia.

Many large-scale studies revealed that exogenous erythropoietin, erythropoiesis-stimulating agents, have no renoprotective effects. We reported the renoprotective effects of endogenous erythropoietin production on renal function in ischemic reperfusion injury (IRI) of the kidney using the prolyl hydroxylase domain (PHD) inhibitor, Roxadustat. The purpose of this study was to investigate the effects of daprodustat on the progression of chronic renal failure. We retrospectively investigated the effects of daprodustat on the progression of chronic renal failure and renal anemia in patients with stages 3a-5 chronic kidney diseases (estimated glomerular filtration rate, eGFR < 60 mL/min/1.73 m2). The results show that daprodustat largely slowed the reduction in eGFR. The recovery of renal function was observed in some patients. Daprodustat is useful not only for renal anemia but also for the preservation of renal function. The renoprotective effect of daprodustat was small in patients with serum creatinine larger than 3-4 mg/dL because of low residual renal function. The appearance of renal anemia would be a sign of the time to start using daprodustat.

FBXW7-Mediated Downregulation of GPX4 Aggravates Acute Kidney Injury Following Ischemia‒Reperfusion.

Acute kidney injury (AKI) is a prevalent and potentially life-threatening complication characterized by a high incidence and mortality. A large number of studies have emphasized the role of ferroptosis in AKI. Moreover, FBXW7, a ubiquitin ligase, has been implicated in acute organ injury. Analysis of the GEO database (GSE98622) revealed increased FBXW7 mRNA levels in the kidney following ischemia‒reperfusion (IR). However, the role of FBXW7 in AKI has not been elucidated. Therefore, this study aimed to investigate the role of FBXW7 in IR-AKI and its underlying mechanisms. Here, we found that IR could induce AKI and increase FBXW7 expression, while the ferroptosis inhibitor Fer-1 alleviated AKI and decreased FBXW7 expression. Furthermore, we treated HK-2 cells with hypoxia for 12h and reoxygenation for 4h (H12R4) to simulate IR-AKI and investigated the impact of modulating FBXW7 expression on ferroptosis by employing ferroptosis-related agonists or inhibitors. Our findings revealed that H12R4 induced HK2 ferroptosis and increased the expression of FBXW7. FBXW7 overexpression in control cells exacerbated erastin-induced ferroptosis, and FBXW7 knockdown inhibited ferroptosis in H12R4-treated cells. Mechanistically, we confirmed that FBXW7 can bind to GPX4, a key molecule that inhibits ferroptosis. The half-life of the GPX4 protein decreased after FBXW7 overexpression, GPX4 ubiquitination increased after H12R4, and GPX4 degradation decreased after FBXW7 knockdown. In conclusion, our results indicated that FBXW7 plays an important role in the development of IR-AKI by promoting ferroptosis through the downregulation of GPX4 expression. This study provides new insight into FBXW7 as a potential target for treating AKI.

Cordycepin ameliorates kidney injury by inhibiting gasdermin D-mediated pyroptosis of renal macrophages through nuclear factor kappa-B.

To explain the effect and mechanism of cordycepin (COR) in resisting acute kidney injury (AKI). Network pharmacology was employed to analyze the correlations between COR, AKI, and pyroptosis, as well as the action target of COR. A mouse model of AKI was established by ischemia reperfusion injury (IRI), andafter treatment with COR, the renal function, tissue inflammatory cytokine levels, and pyroptosis-related signals were detected in mice. In in-vitro experiments, damage of renal macrophages was caused bythe oxygen-glucose deprivationmodel, and pyroptosis indicators and inflammatory cytokine levels were assayed after COR treatment. Network pharmacological analysis revealed that nuclear factor kappa-B (NF-κB) was the primary action target of CORand that COR could inhibit kidney injury and tissue inflammation during IRI by inhibiting NF-κB-mediated gasdermin D cleavage. When NF-κB was inhibited, the effect of COR was weakened. COR in renal macrophages could inhibit pyroptosis and lower the levels of inflammatory cytokines, whose effect was associated with NF-κB. Our study finds that COR can play an anti-inflammatory role and inhibit the progression of AKI through the NF-κB-mediated pyroptosis, which represents its nephroprotective mechanism.

Deficiency of flavin-containing monooxygenase 3 protects kidney function after ischemia–reperfusion in mice

The kidney is vulnerable to ischemia and reperfusion (I/R) injury that can be fatal after major surgery. Currently, there are no effective treatments for I/R-induced kidney injury. Trimethylamine N-oxide (TMAO) is a gut-derived metabolite linked to many diseases, but its role in I/R-induced kidney injury remains unclear. Here, our clinical data reveals an association between preoperative systemic TMAO levels and postoperative kidney injury in patients after post-cardiopulmonary bypass surgery. By genetic deletion of TMAO-producing enzyme flavin-containing monooxygenase 3 (FMO3) and dietary supplementation of choline to modulate TMAO levels, we found that TMAO aggravated acute kidney injury through the triggering of endoplasmic reticulum (ER) stress and worsened subsequent renal fibrosis through TGFβ/Smad signaling activation. Together, our study underscores the negative role of TMAO in I/R-induced kidney injury and highlights the therapeutic potential through the modulation of TMAO levels by targeting FMO3, thereby mitigating acute kidney injury and preventing subsequent renal fibrosis.

Renal protective effects of helix B surface polypeptide in rats with puromycin aminonucleoside nephropathy

Background Recent studies have reported that helix B surface polypeptide (HBSP), an erythropoietin derivative, exhibits strong tissue protective effects, independent of erythropoietic effects, in a renal ischemia-reperfusion (IR) injury model. Meanwhile, the transforming growth factor-β (TGF-β) superfamily member glial cell line-derived neurotrophic factor (GDNF) demonstrated protective effect on podocytes in vitro. Using a rat puromycin aminonucleoside nephropathy (PAN) model, this study observed the renal protective effect of HBSP and investigated its renal protective effect on podocytes and mechanism related to GDNF. Methods Rats nephropathy model was induced by injection of 60 mg/kg of PAN via the tail vein. Rats in the PAN + HBSP group were injected intraperitoneally with HBSP (8 nmol/kg) 4 h before the model was induced, followed by intraperitoneal injections of HBSP once every 24 h for 7 consecutive days. The 24-hour urinary protein level was measured once every other day, and blood and renal tissue samples were collected on the 7th day for the examination of renal function, complete blood count, renal pathological changes and the expression levels of GDNF. Results Compared with the control group, the PAN nephropathy rat model showed a large amount of urinary protein. The pathological manifestations were mainly extensive fusion and disappearance of foot processes, along with vacuolar degeneration of podocytes and their separation from the glomerular basement membrane. GDNF expression was upregulated. Compared with the PAN + vehicle group, the PAN + HBSP group showed decreased urinary protein (p < 0.05). Pathological examination revealed ameliorated glomerular injury and vacuolar degeneration of podocytes. The expression of GDNF in the PAN nephropathy group was increased, when compared with the control group. The greatest expression of GDNF observed in the PAN + HBSP group (p < 0.05). Conclusions The expression of GDNF in the kidney of PAN rat model was increased. HBSP reduced urinary protein, ameliorated pathological changes in renal podocytes, increased the expression of GDNF in the PAN rat model. HBSP is likely to exert its protective effects on podocytes through upregulation of GDNF expression.

Multiparametric MRI based assessment of kidney injury in a mouse model of ischemia reperfusion injury

Kidney diseases pose a global healthcare burden, with millions requiring renal replacement therapy. Ischemia/reperfusion injury (IRI) is a common pathology of acute kidney injury, causing hypoxia and subsequent inflammation-induced kidney damage. Accurate detection of acute kidney injury due to IRI is crucial for timely intervention. We used longitudinal, multi-parametric magnetic resonance imaging (MRI) employing arterial spin labelling (ASL), diffusion weighted imaging (DWI), and dynamic contrast enhanced (DCE)-MRI to assess IRI induced changes in both the injured and healthy contralateral kidney, in a unilateral IRI mouse model (n = 9). Multi-parametric MRI demonstrated significant differences in kidney volume (p = 0.001), blood flow (p = 0.002), filtration coefficient (p = 0.038), glomerular filtration rate (p = 0.005) and apparent diffusion coefficient (p = 0.048) between the injured kidney and contralateral kidney on day 1 post-IRI surgery. Identification of the injured kidney using principal component analysis including most of the imaging parameters demonstrated an area under the curve (AUC) of 0.97. These results point to the utility of multi-parametric MRI in early detection of IRI-induced kidney damage suggesting that the combination of various MRI parameters may be suitable for monitoring the extent of injury in this model.

An injectable multicomponent integrated microgel promotes cardiomyocyte regeneration and heart function after ischemia reperfusion injury

Myocardial ischemia reperfusion (I/R) injury frequently impacts the outcome of patients with coronary heart disease and lacks effective therapeutic strategies. We have summarized the challenges in treating IR injury into three aspects, namely inflammatory reaction, fibrosis, and impaired proliferation ability of myocardial tissue. To address these issues, we have developed an injectable composite microgel called DMP@mgel by integrating three types of biomaterials: placental-derived mesenchymal stem cells loaded microgel, PEDOT:PSS loaded microgel, and siRNA-loaded carrier DP7-C. Upon injection into the injured area, DMP@mgel could regulate the inflammatory microenvironment, promote angiogenesis by the function of stem cells paracrine. Additionally, it enhances coupling between myocardial cells due to its high electrical conductivity. Moreover, DP7-C/siRNA complex can efficiently transfect into myocardial cells to inhibit Hippo pathway activity and promote cell proliferation. The electrostatic interaction enables DP7-C to combine all components into a stable delivery system. In vitro and in vivo experiments confirmed that each ingredient of DMP@mgel exhibits their respective functions such as neovascularization promotion, Hippo pathway inhibition, and antioxidation capability. Finally, administration of DMP@mgel in I/R injured rats significantly improved heart function while reducing fibrosis as evidenced by echocardiography results along with Evans blue staining and histological examination.

Inhibitors of NLRP3 Inflammasome Formation: A Cardioprotective Role for the Gasotransmitters Carbon Monoxide, Nitric Oxide, and Hydrogen Sulphide in Acute Myocardial Infarction.

Myocardial ischaemia reperfusion injury (IRI) occurring from acute coronary artery disease or cardiac surgical interventions such as bypass surgery can result in myocardial dysfunction, presenting as, myocardial "stunning", arrhythmias, infarction, and adverse cardiac remodelling, and may lead to both a systemic and a localised inflammatory response. This localised cardiac inflammatory response is regulated through the nucleotide-binding oligomerisation domain (NACHT), leucine-rich repeat (LRR)-containing protein family pyrin domain (PYD)-3 (NLRP3) inflammasome, a multimeric structure whose components are present within both cardiomyocytes and in cardiac fibroblasts. The NLRP3 inflammasome is activated via numerous danger signals produced by IRI and is central to the resultant innate immune response. Inhibition of this inherent inflammatory response has been shown to protect the myocardium and stop the occurrence of the systemic inflammatory response syndrome following the re-establishment of cardiac circulation. Therapies to prevent NLRP3 inflammasome formation in the clinic are currently lacking, and therefore, new pharmacotherapies are required. This review will highlight the role of the NLRP3 inflammasome within the myocardium during IRI and will examine the therapeutic value of inflammasome inhibition with particular attention to carbon monoxide, nitric oxide, and hydrogen sulphide as potential pharmacological inhibitors of NLRP3 inflammasome activation.

ST2 + T-Regulatory Cells in Renal Inflammation and Fibrosis after Ischemic Kidney Injury.

Inflammation is a major cause of kidney injury. The Interleukin (IL)-1 family cytokine IL-33 is released from damaged cells and modulates the immune response through its receptor ST2 expressed on many cell types, including regulatory T-cells (Tregs). While a proinflammatory role of IL-33 has been proposed, exogenous IL-33 expanded Tregs and suppressed renal inflammation. However, the contribution of endogenous IL-33/ST2 for the role of Tregs in the resolution of kidney injury has not been investigated. We used murine renal ischemia-reperfusion injury and kidney organoids to delineate the role of the ST2 and amphiregulin (AREG) specifically in Treg cells using targeted deletion. Bulk and single-cell RNA sequencing was performed on flow-sorted Tregs from spleen and CD4 T-cells from post-ischemic kidneys respectively. The protective role of ST2-sufficient Tregs was analyzed using a novel co-culture system of syngeneic kidney organoids and Treg cells under hypoxic conditions. Bulk RNA-sequencing of splenic and single-cell-RNA-sequencing of kidney T-cells showed that ST2+ Tregs are enriched for genes related to Treg proliferation and function. Genes for reparative factors such as AREG were also enriched in ST2+ Tregs. Treg-specific deletion of ST2 or AREG exacerbated kidney injury and fibrosis in the unilateral ischemia reperfusion injury model. In co-culture studies, WT but not ST2-deficient Tregs preserved the hypoxia-induced loss of kidney-organoid viability, which was restored by AREG supplementation. Our study identified the role of the IL-33/ST2 pathway in Tregs for resolution of kidney injury. The transcriptome of ST2+ Tregs was enriched for reparative factors including AREG. Lack of ST2 or AREG in Tregs worsened kidney injury. Tregs protected kidney organoids from hypoxia in ST2 and AREG-dependent manner. Thus Treg-based approaches could be of benefit for resolution of renal injury.

Exogenous leptin alleviates glutamate-excitotoxic injury caused by cerebral ischemia–reperfusion in mice by affecting the expression of glutamate transporters

Ischemic stroke is characterized by high morbidity and mortality and a lack of effective therapeutic interventions. Leptin plays an important role in regulating oxidative stress, angiogenesis, hematopoiesis, etc. Although recent studies have found a neuroprotective effect of leptin, little is known about its role in cerebral ischemia. This study explores the possible roles and potential preventative mechanisms of leptin in cerebral ischemia–reperfusion injury (CIRI). An in vivo middle cerebral artery occlusion/reperfusion (MCAO/R) mouse model was used to replicate the CIRI model, low (0.5 mg/kg), medium (1 mg/kg) and high (2 mg/kg) concentrations of leptin were injected intraperitoneally immediately after inserting the embolic line. After 1.5 h of ischemia and 24 h of reperfusion, we examined the neural function of the mice, collected brain tissue for histological examination, and screened for the optimal concentrations of leptin intervention. On this basis, we observed the changes of cortical apoptosis injury, intracellular calcium fluorescence intensity and astrocyte glial fibrillary acidic protein (GFAP) expression and morphological changes. In addition, we also tested the expression of transporters and metabolism-related enzymes (VGLUT-1, VGLUT-2, GLAST, GLT-1, GS, ATP1α1), the expression of inflammatory factors and the content of glutamate (Glu). Compared with the I/R group, we found that leptin improved neurological deficits, reduced the area of infarcts, maintained the normal morphology of astrocytes (AST), downregulated the expression of VGLUT-1, and upregulates the expression of GLT-1 and GLAST, thereby reducing the content of Glu in the synaptic cleft. Our studies suggest that leptin may have a neuroprotective effect by decreasing the excitotoxicity of glutamate.

Suppression of inner blood-retinal barrier breakdown and pathogenic Müller glia activation in ischemia retinopathy by myeloid cell depletion

Ischemic retinopathies including diabetic retinopathy are major causes of vision loss. Inner blood-retinal barrier (BRB) breakdown with retinal vascular hyperpermeability results in macular edema. Although dysfunction of the neurovascular unit including neurons, glia, and vascular cells is now understood to underlie this process, there is a need for fuller elucidation of the underlying events in BRB dysfunction in ischemic disease, including a systematic analysis of myeloid cells and exploration of cellular cross-talk. We used an approach for microglia depletion with the CSF-1R inhibitor PLX5622 (PLX) in the retinal ischemia-reperfusion (IR) model. Under non-IR conditions, PLX treatment successfully depleted microglia in the retina. PLX suppressed the microglial activation response following IR as well as infiltration of monocyte-derived macrophages. This occurred in association with reduction of retinal expression of chemokines including CCL2 and the inflammatory adhesion molecule ICAM-1. In addition, there was a marked suppression of retinal neuroinflammation with reduction in expression of IL-1b, IL-6, Ptgs2, TNF-a, and Angpt2, a protein that regulates BRB permeability. PLX treatment significantly suppressed inner BRB breakdown following IR, without an appreciable effect on neuronal dysfunction. A translatomic analysis of Müller glial-specific gene expression in vivo using the Ribotag approach demonstrated a strong suppression of Müller cell expression of multiple pro-inflammatory genes following PLX treatment. Co-culture studies of Müller cells and microglia demonstrated that activated microglia directly upregulates Müller cell-expression of these inflammatory genes, indicating Müller cells as a downstream effector of myeloid cells in retinal IR. Co-culture studies of these two cell types with endothelial cells demonstrated the ability of both activated microglia and Müller cells to compromise EC barrier function. Interestingly, quiescent Müller cells enhanced EC barrier function in this co-culture system. Together this demonstrates a pivotal role for myeloid cells in inner BRB breakdown in the setting of ischemia-associated disease and indicates that myeloid cells play a major role in iBRB dysregulation, through direct and indirect effects, while Müller glia participate in amplifying the neuroinflammatory effect of myeloid cells.

Gastrodin against oxidative stress-inflammation crosstalk via inhibiting mtDNA/TLR9 and JAK2/STAT3 signaling to ameliorate ischemic stroke injury

The pathway of Janus-activated kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) (termed as JAK2/STAT3) plays an active role in stroke-related inflammation induced by ischemic stress. Gastrodin, the primary compound in Gastrodia elata Bl, has been identified for its notable neuroprotective effects and demonstrated to ameliorate cerebral ischemia–reperfusion but its exact mechanisms governing this defense are still unclear. This study aims to investigate whether gastrodin can regulate mitochondrial function via the JAK2/STAT3 pathway to limit cerebral ischemia–reperfusion. In vivo, gastrodin significantly reduced infarct volume, improved neurobiological function, attenuated neuronal apoptosis, oxidative stress, mitochondrial impairment, mtDNA leakage, and inflammatory responses. At the cellular level, gastrodin administration rescued OGD/R-induced cell apoptosis, oxidative stress, and mitochondrial dysfunction. Mechanistically, gastrodin notably suppressed Toll-like receptor 9 (TLR9) expression, important for the recognition of disrupted endogenous DNA to produce inflammatory reactions. Furthermore, gastrodin mitigated inflammation by inhibiting JAK2/STAT3 signaling, influencing inflammatory factors to aggravate inflammation. Notably, the effects of gastrodin were abolished by Coumermycin A1 (C-A1), a JAK2 agonist, validating the role of JAK2/STAT3 signaling. In summary, gastrodin enhances the protective effect against mitochondrial damage in ischemic stroke by inhibiting JAK2/STAT3 signaling. Gastrodin is a possible therapy for cerebral ischemia.

Investigation of preconditioning and the protective effects of nicotinamide against cerebral ischemia-reperfusion injury in rats

This study investigated the antioxidant and neuroprotective effects of nicotinamide combined with ischemic preconditioning against cerebral ischemia reperfusion (CIR) injury. Thirty-five Wistar albino male rats were randomly divided into five groups: sham, preconditioned ischemia/reperfusion (IP+IR), ischemia/reperfusion (IR), preconditioned ischemia/reperfusion + nicotinamide (IP+IR+N), and ischemia/reperfusion + nicotinamide (IR+N). CIR was achieved with bilateral common carotid artery occlusion. IP+IR and IP+IR+N groups 30 min before ischemia; Three cycles of 10 sec ischemia/30 sec reperfusion followed by 20 min IR were applied. The IP+IR+N and IR+N groups received 500 mg/kg nicotinamide intraperitoneally. After 24 h of reperfusion, a neurological evaluation was performed and vertıcal pole test. Biochemically, malondialdehyde (MDA), glutathione (GSH) levels and catalase (CAT) activity were measured in blood and brain tissue samples. Rates of red neurons, sateliosis and spongiosis were determined histopathologically in the prefrontal cortex areas.After CIR, MDA levels increased significantly in serum and brain tissue in the IR group compared to the sham group, while GSH and CAT activity decreased in the brain tissue (p < 0.05). MDA levels in the tissues were found significantly decreased in the IR+N group compared to the IR group (p < 0.05). Administration of nicotinamide together with IP significantly decreased MDA levels in brain tissue and increased GSH and CAT activity (p < 0.05). Compared to the IR group, the morphological and neurological damage in the prefrontal cortex areas decreased in the IP+IR, IP+IR+N, and IR+N groups (p < 0.05). In addition, red neuron, sateliosis and spongiosis rates increased significantly in the IR group compared to the Sham, IP+IR+N, IR+N groups (p < 0.001 for all). In neurological evaluation, while the neurological score increased and the time on the vertical pole decreased significantly in the IR group, preconditioning, and nicotinamide groups reversed (p < 0.05). The study’s results show that nicotinamide administration with ischemic preconditioning alleviates cerebral ischemia/reperfusion injury.

Canagliflozin Mitigates Acute Kidney Injury Secondary to Resuscitative Endovascular Balloon Occlusion of the Aorta in a Porcine Model of Hemorrhagic Shock.

We investigated the potential of acute canagliflozin administration to mitigate acute kidney injury (AKI) and attenuate deleterious pro-inflammatory cytokine release in a clinically relevant swine model of severe renal ischemia reperfusion injury (IRI) induced by hemorrhage and aortic occlusion. Long-term canagliflozin use attenuates renal function decline and reduces AKI in diabetes mellitus and heart failure patients. Whilst several reports indicate prophylactic SGLT2 inhibition prevents AKI in IRI, the efficacy of acute administration on IRI and inflammation is not known. Female swine (n=16) underwent controlled hemorrhage of 25% blood volume, followed by 90 min of aortic occlusion at the level of the renal ostia (via Resuscitative Endovascular Balloon Occlusion of the Aorta). A single 300mg dose of oral canagliflozin or vehicle (saline) was delivered 5 mins into aortic occlusion. Hemodynamic monitoring, markers of renal function (serum creatinine, blood urea nitrogen, proteinuria and urinary neutrophil gelatinase-associated lipocalin) and serum cytokine concentrations (including interleukins: IL-1RA, IL-6, IL-8, IL-10, IL-18; and Tumor necrosis factor alpha) were analyzed after IRI, and during a 6h critical care phase. Compared to controls, animals receiving canagliflozin had less severe AKI, improved creatinine clearance, reduced proteinuria, and significantly lower tubular damage as evidenced by histopathology and urinary NGAL. Furthermore, the pro-inflammatory cytokine IL-6 was markedly attenuated without reduction in anti-inflammatory cytokines (IL-1RA and IL-10). A single dose of canagliflozin administered shortly into ischemic insult mitigates AKI and attenuates harmful pro-inflammatory cytokine release following trauma or surgery. These findings suggest a potential novel therapeutic role for canagliflozin in mitigating the effects of renal IRI worthy of further investigation.

Shexiang Tongxin dropping pill ameliorates microvascular obstruction via downregulating ALOX12 after myocardial ischemia-reperfusion

BackgroundMicrovascular dysfunction (MVD) is common in patients with myocardial infarction receiving reperfusion therapy and is associated with adverse cardiac prognosis. Accumulating evidence suggests a protective role of Shexiang Tongxin dropping pill (STDP) in MVD. However, the specific effects and the underlying mechanisms of STDP in the context of MVD after myocardial ischemia-reperfusion (IR) remains unclear. AimsWe aimed to elucidate the role of STDP in MVD induced by IR and the potential mechanisms involved. MethodsMice were orally administered with STDP or normal saline for 5 days before receiving myocardial IR. Cardiac function and microvascular obstruction was measured. Proteomics and single-cell RNA sequencing was performed on mouse hearts. In vitro hyoxia/reoxygenation model was established on mouse cardiac microvascular endothelial cells (MCMECs). ResultsSTDP improved cardiac function and decreased microvascular obstruction (MVO) in mice after myocardial IR. Proteomics identified ALOX12 as an important target of STDP. Single-cell RNA sequencing further revealed that downregulation of ALOX12 by STDP mainly occurred in endothelial cells. The involvement of ALOX12 in the effect of STDP on MVO was validated by manipulating ALOX12 via endothelial-specific adeno-associated virus transfection in vivo and in vitro. In vivo, overexpression of ALOX12 increased whereas knockdown of ALOX12 decreased MVO and thrombus formation. STDP treatment alleviated the detrimental effects of overexpression of ALOX12. In vitro, overexpression of ALOX12 increased endothelial cell inflammation and platelet adhesion to endothelial cells, which was abolished by STDP treatment. ConclusionOur findings suggest that STDP alleviates MVO after IR, with ALOX12 playing a crucial role.

Kirenol alleviates inflammation and oxidative stress to improve myocardial ischemia/reperfusion injury in rats.

The ischemic heart disease gravely threatens human health and even results in death. Kirenol is predominantly derived from the Herba Siegesbeckiae plant species and possesses a wide range of biological effects (such as antibacterial, anti-inflammatory, anti-cancer and cardioprotective). However, the regulatory effects and associated mechanisms of kirenol in myocardial ischemia/reperfusion injury (MI/RI) remain unclear. In this study, firstly, the MI/RI rat model was established. It was demonstrated that kirenol protected against the aggravation of cardiac function in MI/RI rats. In addition, the inflammation was induced by ischemia reperfusion (IR), which was likewise affected by kirenol (5 or 10 mg/kg). Moreover, IR enhanced oxidative stress, a process that was counteracted by kirenol. Next, cell apoptosis was discovered to be heightened after IR, but this effect was neutralized by kirenol. Finally, it was uncovered that kirenol has the ability to block the activation of the NF-κB pathway. In conclusion, it was disclosed that kirenol alleviated inflammation and oxidative stress through modulating the NF-κB pathway to improve MI/RI in rats. This work may offer novel insights for searching useful drugs for treating MI/RI.

A comparative study of the efficiency of mitochondria-targeted antioxidants MitoTEMPO and SKQ1 under oxidative stress

MitoTEMPO (MT) and Visomitin (SKQ1) are regareded as mitochondria-targeted antioxidants, which inhibit production of mitochondrial reactive oxygen species (ROS). However, the differences in function between MT and SKQ1 remain unexplored. Herein, we investigated the differential potency of MT and SKQ1 in mitigating oxidative stress under different conditions. The results indicated that high levels of SKQ1 induced cell death. The appropriate concentrations of MT and SKQ1 can prevent or rescue cell damage triggered by hydrogen peroxide (H2O2) and menadione (MEN). MT and SKQ1 reduced ROS levels and reversed the down-regulation of antioxidant defence genes and enzymes. These effects can alleviate the damage to lipids, proteins, and deoxyribonucleic acid (DNA) caused by oxidative stress and restore adenosine 5′ triphosphate (ATP) generation. Subsequently, we found that MT administration in ischemic reperfusion kidney injury in mice provided superior renal protection compared to SKQ1, as evidenced by reduced plasma levels of kidney injury markers, improved renal morphology, decreased apoptosis, restored mitochondrial function, and enhanced antioxidant capacity. Overall, our findings suggest that MT is safer and has greater potential than SKQ1 as a therapeutic agent to mitigate oxidative stress damage or oxidative renal injury.

Danggui-Shaoyao-San (DSS) ameliorating cognitive impairment in ischemia–reperfusion vascular dementia mice through miR-124 regulating PI3K/Akt signaling pathway

Vascular dementia (VD) is a disease characterized by cognitive impairment and memory loss due to brain cell damage caused by cerebral vascular ischemia. Danggui-Shaoyao-San (DSS) has been used clinically to treat diseases for centuries. The VD model was established by bilateral common carotid artery (BCCA) repeated ischemia–reperfusion (I/R) and caudal bleeding. Target prediction of DSS and miR-124 in PI3K/Akt signaling pathway by network pharmacology. The effect of DSS on cognitive dysfunction were evaluated through methods such as behavioral experiments, cerebral blood flow monitoring, HE and Nissl staining, western blot, and q-PCR. Prediction result showed that both DSS and miR-124 could target Akt1. DSS treatment significantly reduced hippocampal cell damage, improved learning and memory ability. Mechanically, DSS treatment up-regulated the expression levels of PI3K and Akt protein, and its gene. Bcl-2/Bax index is up-regulated and cell apoptosis reduced. LC3II/LC3I index decreased and autophagy of brain cells increased. Moreover, DSS down-regulated the expression level of miR-124. And inhibition of miR-124 up-regulate the expression of PI3K, Akt. These results suggested that DSS can reduce the content of miR-124 in the hippocampus of VD mice, thus regulating the PI3K/Akt signaling pathway and improving the learning and memory ability of VD mice.

Pinobanksin Attenuates Cerebral Ischemia–Reperfusion Injury in Rats Through Mitigating the Inflammatory Responses

Pinobanksin Attenuates Cerebral Ischemia–Reperfusion Injury in Rats Through Mitigating the Inflammatory Responses

The effects and significance of Dicyclopentadiene on the expression of Intersectin-1 after cerebral ischemia-reperfusion in rats

ObjectiveThis study mainly observed the changes in Intersectin-1 (ITSN-1) expression in rat brain tissue after ischemia-reperfusion intervened by Dicyclopentadiene. MethodsSD rats were randomly divided into non-middle Cerebral Artery Occlusion model group (normal group, sham operation group) and Middle Cerebral Artery Occlusion (MCAO) model group [Ischemia reperfusion (cerebral ischemia reperfusion)] reperfusion,IR) (6h, 24h, 72h, 1w, 2w) group, butylphthalein intervention group], First of all, Use Western The expression of ITSN-1 in the cerebral tissue of infarction side after ischemia-reperfusion injury in each group was measured by blotting, and then the loss and degree of nerve function after ischemia-reperfusion injury in each group was evaluated by Zea-Longa scoring method. The morphological changes of cells in the ischemic penumbra region in the normal group and the MCAO model group for 24h were observed by HE staining. Next, 24h was selected as the reperfusion point for intervention with butylphthalein sodium chloride injection. Finally, Zea-Longa scoring method was used to evaluate whether the rats had neurological impairment and its degree, TTC (Triphenyltetrazolium chloride) staining was used to determine whether the rats had cerebral infarction and its extent, and Western The expression of ITSN-1 in the cerebral tissue of infarcted rats after ischemia-reperfusion injury was measured by blotting. Results1. Zea-Longa scoring: Scores, except for the normal group and sham operation group (which scored 0), ranged between 2.75 ± 0.46 in the ischemia-reperfusion 24h group and 1.88 ± 0.35 in the Dicyclopentadiene intervention group, showing statistically significant decreases (P<0.05). 2. HE staining results: The cell structures in the brain tissues of normal group rats were normal with regular nuclear shapes and sizes. There were no obvious abnormal changes. Rats in the ischemia-reperfusion 24h group showed obviously swollen cells, reduced and aggregated nucleus, and cell necrosis in the ischemic penumbra. 3. TTC staining results: Except for the normal group and the sham operation group, which had no infarcts, the ischemia-reperfusion 24h group had the largest volume ratio of cerebral infarction. The volume ratio of cerebral infarction in the Dicyclopentadiene intervention group relatively reduced, making a difference with statistical significance (P<0.05). 4. Western blotting results: After cerebral ischemia-reperfusion in rats, ITSN-1 expression in the infarction-side brain tissue dynamically changed. ITSN-1 expression in the ischemia-reperfusion 24h group was significantly lower among other groups compared to the normal group (P<0.05). After 24 hours, the expression gradually increased after using Dicyclopentadiene intervention, the difference was statistically significant (P<0.05). ConclusionAfter cerebral ischemia-reperfusion in rats, ITSN-1 expression dynamically changed in the infarction-side brain tissue. Dicyclopentadiene can alleviate ischemia-reperfusion injuries in rats, which might be related to the regulation of ITSN-1 expression.