Hypoxia-reoxygenation Injury Research Articles

Modulating the Biliverdin Reductase (BVR)/ERK1/2 Axis to Attenuate Oxidative Stress in Rat Arterial Rings

Background: Biliverdin reductase (BVR) plays a central role in bile pigment metabolism by reducing biliverdin (BV) to bilirubin (BR), a potent antioxidant that scavenges reactive oxygen species (ROS) under normal and pathological conditions. Elevated oxidative stress activates extracellular signal-regulated protein kinases 1/2 (ERK1/2) signaling, which strongly interacts with BVR’s C and D motifs, forming the BVR/ERK1/2 axis. In pathological states, increased ERK1/2 activity inhibits BVR’s ability to convert BV to BR, exacerbating oxidative damage and contributing to cardiovascular disease. Therefore, the interaction between BVR and ERK1/2 is critical in modulating oxidative stress. Objectives: This study aimed to evaluate the effects of BR and the ERK1/2 inhibitor PD-98059, both individually and in combination, on ROS levels, ERK1/2 activity, and vascular responses under normoxic and hypoxia-reoxygenation (H-R) injury conditions. Methods: Aortic rings from rats were subjected to equal distending pressure after oxidative stress induction using 22'-Azobis (2-amidinopropane) dihydrochloride (ABAP) in an organ bath. Different doses of BR were administered in combination with the ERK1/2 inhibitor PD-98059 to assess their impact on ROS depletion, vascular relaxation, and maximal effect (Emax). Results: The combination of BR and PD-98059 significantly enhanced aortic relaxation and Emax under both normoxic and H/R conditions compared to either treatment alone. Inhibiting ERK1/2 with PD-98059 appeared to upregulate BVR activity, increasing BR synthesis and reducing oxidative damage in aortic rings. Conclusions: Biliverdin reductase plays a vital role in defending against oxidative stress and endothelial dysfunction through its dual-specificity kinase activity and interaction with ERK1/2. ERK1/2 inhibition further enhances BR’s ROS-scavenging ability and vascular protective effects. Targeting the interaction between BVR and ERK1/2 holds potential as an effective therapeutic strategy for conditions characterized by excessive ROS levels, such as cardiovascular diseases.

Chitinase 3-like 1 overexpression aggravates hypoxia-reoxygenation injury in IEC-6 cells by inhibiting the PI3K/AKT signalling pathway.

Intestinal ischaemia-reperfusion (I/R) is a common clinical pathology with high incidence and mortality rates. However, the mechanisms underlying intestinal I/R injury remain unclear. In this study, we investigated the role and mechanism of chitinase 3-like 1 (CHI3L1) during intestinal I/R injury. Therefore, we analysed the expression levels of CHI3L1 in the intestinal tissue of an intestinal I/R rat model and explored its effects and mechanism in a hypoxia-reoxygenation (H/R) IEC-6 cell model. We found that intestinal I/R injury elevated CHI3L1 levels in the serum, ileum and duodenum, whereas H/R enhanced CHI3L1 expression in IEC-6 cells. The H/R-induced inhibition of proliferation and apoptosis was alleviated by CHI3L1 knockdown and aggravated by CHI3L1 overexpression. In addition, CHI3L1 knockdown alleviated, and CHI3L1 overexpression aggravated, the H/R-induced inflammatory response and oxidative stress. Mechanistically, CHI3L1 overexpression weakened the activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway, suppressed the nuclear translocation of Nrf2, and promoted the nuclear translocation of nuclear factor κB (NF-κB). Moreover, CHI3L1 knockdown had the opposite effect on the PI3K/AKT pathway, Nrf2, and NF-κB. Moreover, the PI3K inhibitor LY294002 blocked the effect of CHI3L1 knockdown on the H/R-induced inhibition of proliferation, apoptosis, inflammatory response and oxidative stress. In conclusion, CHI3L1 expression was induced during intestinal I/R and H/R injury in IEC-6 cells, and CHI3L1 overexpression aggravated H/R injury in IEC-6 cells by inhibiting the PI3K/AKT signalling pathway. Therefore, CHI3L1 may be an effective target for controlling intestinal I/R injury.

Unravelling pharmacological mechanisms and effects of Tianma Siwu Decoction-derived compounds on ischemic stroke by multidimensional network pharmacological analysis

Ethnopharmacological relevanceIschemic stroke (IS) a complex pathological event emerging as one of the most serious threats with huge economic impact in the 21st century. Following IS, multiple cascades and pathways are stimulated, culminating in long term consequences. One of Chinese Traditional Medicine, Tianma Siwu Decoction (TSD), is known to have sedative-hypnotic, anticonvulsant and anti-inflammatory effects, which is usually used to treat migraine and ischemic stroke, but its potential pharmacological mechanism remains unclear. Aim of the studyThis study is aimed to identify the active principles from TSD that has strong pharmacological effect on the treatment of IS. Materials and methodsBased on liquid chromatography-triple quadrupole mass spectrometry (LC-Q-MS/MS) technology, a new three-step-based approach integrating concentration parameters and Quality marker (Q-marker) with network pharmacology and bioactivity evaluation to explore the therapeutic effects and mechanisms of TSD on ischemic stroke. Ultimately, as the main herb of the TSD, high-concentration compounds from Gastrodia elata Blume (GEB) were identified and collected by LC-Q-MS/MS, and an optimized analytical model in multidimensional network pharmacology was introduced to more accurately explore the potential mechanisms by which TSD affects IS. ResultsThe results showed that 280 overlapping targets of TSD were obtained after the introduction of compound concentration parameters into the multidimensional network pharmacology analysis. Additionally, TSD might regulate IS through the AGE-RAGE and Rap1 signaling pathways. Through an in vitro hypoxia-reoxygenation injury cell model, it was discovered that as the Q-markers of GEB, gastrodin and parishin could effectively reduce neuronal hypoxic injury by modulating the expression levels of p-JNK and p-p38 proteins. According to the results of molecular docking, gastrodin and baicalin exhibits strong binding affinity to GAPDH and MAPK3, respectively (≦-7 kcal/mol). ConclusionWe discovered that compound concentration is a key factor that influence the activity of substances, affects the accuracy and reliability of predictive outcomes. Consequently, the study enhances the network pharmacology model by incorporating concentration factors, aiming for a more accurate understanding of the potential mechanisms behind TSD anti-ischemic stroke actions.

8071 Prevention Of Acute Kidney Injury By Reducing Mitochondrial Dysfunction In Diabetic Mice

Abstract Disclosure: M. Kim: None. C. Oh: None. A. Khang: None. J. Jeon: None. I. Lee: None. Background: Acute Kidney Injury (AKI) significantly contributes to the pathogenesis of diabetic kidney disease, often exacerbating chronic kidney disease (CKD) and accelerating the need for dialysis. Mitochondrial dysfunction, induced by an increase in reactive Oxygen Species (ROS) and inflammation, plays a crucial role in AKI. This study investigates the prevention of AKI by reducing mitochondrial dysfunction through pyruvate dehydrogenase kinase (PDK) inhibition in an ischemia-reperfusion (IR)-induced AKI model using streptozotocin (STZ)-induced diabetic mice. Methods: We utilized an IR-induced AKI model in STZ-induced diabetic C57BL6/J mice, subjecting them to IR by clamping both renal pedicles. Mitochondrial function tests, cellular apoptosis, and inflammatory markers were evaluated in NRK-52E cells and mouse primary tubular cells after hypoxia and reoxygenation using a hypoxia workstation. Results: In diabetic mice experiencing AKI following IR injury, there was a significant increase in pyruvate dehydrogenase E1α (PDHE1α) phosphorylation. This correlated with a notable increase in mitochondrial damage - TEM images of mice with IR-induced kidney injury revealed distension, loss of cristae, and fragmentation of the mitochondria. We also observed a decrease in oxygen consumption rate (OCR) accompanied by increased ROS, as well as increased production of inflammatory markers. Remarkably, the pan-PDK inhibitor, sodium dichloroacetate (DCA), mitigated apoptosis, attributable to the reduction of PDHE1α phosphorylation levels as well as normalized mitochondrial morphology and function. DCA treatment lessened oxidative stress and decreased the production of inflammatory markers following IR-induced AKI or hypoxia-reoxygenation injury. Conclusion: Restoration of mitochondrial function by DCA effectively alleviated renal injury by decreasing ROS production and inflammation, highlighting its critical role in IR-mediated damage. These results suggest another potential target for renal protection during AKI; therefore, the prevention of acute kidney injury through the inhibition of PDK could be a promising therapeutic approach for treating Diabetic Kidney Disease (DKD). Presentation: 6/1/2024

Retraction Note: Yap-Hippo pathway regulates cerebral hypoxia-reoxygenation injury in neuroblastoma N2a cells via inhibiting ROCK1/F-actin/mitochondrial fission pathways.

Retraction Note: Yap-Hippo pathway regulates cerebral hypoxia-reoxygenation injury in neuroblastoma N2a cells via inhibiting ROCK1/F-actin/mitochondrial fission pathways.

Di(2-ethylhexyl) phthalate exposure aggravates hypoxia/reoxygenation injury in cerebral endothelial cells by downregulating epithelial cadherin expression.

Di-(2-ethylhexyl) phthalate (DEHP) is a widely used plasticizer that has adverse health effects. Most phthalates exhibit reproductive toxicity and are associated with diseases such as cardiovascular disorders. However, the effect of DEHP exposure on acute hypoxia/reperfusion injury remains unknown. Therefore, we assessed whether hypoxia/reperfusion injury is aggravated by exposure to DEHP and investigated plausible underlying mechanisms, including oxidative stress and expression of cyclooxygenase-2 (COX-2)/prostaglandin E2 (PGE2) and endothelial junctional proteins. bEnd.3 cells were exposed to DEHP and subsequently subjected to oxygen-glucose deprivation (OGD). Cell viability was analyzed using 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) proliferation assay. The effect of DEHP/OGD/reoxygenation (R) was evaluated by assessing the levels of NO, reactive oxygen species (ROS), and PGE2. The expression of COX-2, cleaved caspase-3, cleaved PARP, inducible nitric oxide synthase (iNOS), and the endothelial tight junction proteins claudin-5 and ZO-1 was evaluated using quantitative polymerase chain reaction and western blotting. OGD/R decreased cell viability, and DEHP exposure before OGD/R further aggravated cell viability. DEHP/OGD/R significantly increased NO, PGE2, and ROS production following OGD/R. In the DEHP/OGD/R group, iNOS, COX-2, cleaved caspase-3, and cleaved PARP expression increased, and claudin-5 and ZO-1 levels decreased compared with those in the OGD/R group. E-Cadherin expression decreased significantly after DEHP/OGD/R exposure compared with that after OGD/R; this decrease in expression was recovered by treatment with the COX-2 inhibitor indomethacin and antioxidant N-acetylcysteine. Exposure to DEHP exacerbated hypoxia-reoxygenation injury. The enhanced damage upon DEHP exposure was associated with increased oxidative stress and COX-2 expression, leading to E-cadherin downregulation and increased apoptosis.

Curcumin Reduces Hypoxia/Reperfusion Injury of Cardiomyocytes byStimulating Vascular Endothelial Cells to Secrete FGF2.

Endothelial cells (ECs) can provide cell protection for cardiomyocytes (CMs) under hypoxia-reoxygenation (HR) conditions by secreting derived factors. This study aimed to explore the role of curcumin (CUR) in ECs for protecting CMs from HR injury. A co-culture system for ECs and CMs was set up, and subjected to HR. The transcription, expression, and secretion of FGF2 were detected by RT-qPCR, western blot, and ELISA, respectively. siRNAs specifically targeting FGF2 were transfected into ECs. FGF2 receptor- specific inhibitors (AZD4547) were used to treat CMs. The co-culture with ECs did not affect the proliferation of CMs, while CUR and ECs co-culture had a synergistic effect on promoting the proliferation of CMs in HR. Furthermore, the co-culture with ECs did not affect the apoptosis and autophagy of CMs in HR. However, the co-culture of ECs after CUR treatment inhibited the apoptosis and autophagy of CMs in HR. CUR treatment significantly enhanced FGF2 mRNA, protein, and secretion levels of ECs in HR. In addition, CUR treatment increased FGF2 levels in the CMs medium in the ECs and CMs co-culture system. The reduction of FGF2 levels in the medium and the inhibition of FGF2 receptors significantly inhibited the proliferation of CMs and significantly promoted the apoptosis and autophagy of CMs in HR. Focusing on the protective effects of CUR and ECs on cardiomyocytes is of great significance for the treatment of clinical myocardial HR injury.

Long Non-Coding RNA PCAT19 Suppresses Cell Proliferation and Angiogenesis in Coronary Artery Disease through Interaction with GCNT2.

LncRNAs involvement in heart disease, however, the effect of lncRNA prostate cancer-associated transcript 19 (PCAT19) in coronary artery disease (CAD) remains unclear. In the current study, we aimed to verify the role of PCAT19 in CAD. We first investigated the differentially expressed lncRNAs in different Genes Expression Omnibus (GEO) database. We then detected lncRNAs expression in healthy volunteers and acute myocardial infarction (AMI) patients by qRT‑PCR. The correlation of PCAT19 and Glucosaminyl (N-Acetyl) Transferase 2 (GCNT2) was analyzed. Human coronary artery endothelial cells (HCAECs) was used to conduct cell hypoxia-reoxygenation (H/R) injury model to imitate AMI injury. CCK8, BrdU, tube formation assay were used to detect cell viability, proliferation, and angiogenesis. Immunofluorescence, western blotting were used to detect ki67, VEGFA, PCNA, CD31, and GCNT2 expression, respectively. We obtained six different lncRNAs from GEO database and identified PCAT19 high expression in AMI patients. PCAT19 was positive correlation to GCNT2. Further experiments presented that PCAT19 knockdown promoted cell viability, proliferation and angiogenesis, GCNT2 knockdown also promoted cell viability, proliferation, and angiogenesis. These results confirmed by the inhibition of Ki67 and VEGFA. Importantly, PCAT19 overexpression suppressed cell proliferation and angiogenesis, these results also confirmed by the inhibition of PCNA and CD31. However, the inhibitory effect of PCAT19 overexpression was reversed by GCNT2 knockdown. Our study indicated that PCAT19 plays an important role in the CAD disease, its effects was related to GCNT2. Our research provides a novel sight for the effect of PCAT19 on CAD.

Gastrodin exerts perioperative myocardial protection by improving mitophagy through the PINK1/Parkin pathway to reduce myocardial ischemia-reperfusion injury

BackgroundAlthough blood flow is restored after treatment of myocardial infarction (MI), myocardial ischemia and reperfusion (I/R) can cause cardiac injury, which is a leading cause of heart failure. Gastrodin (GAS) exerts protective effects against brain, heart, and kidney I/R. However, its pharmacological mechanism in myocardial I/R injury (MIRI) remains unclear. PurposeGAS regulates autophagy in various diseases, such as acute hepatitis, vascular dementia, and stroke. We hypothesized that GAS could repair mitochondrial damage and regulate autophagy to protect against MIRI. Study designMale C57BL/6 mice and H9C2 cells were subjected to I/R and hypoxia-reoxygenation (H/R) injury after GAS administration, respectively, to assess the impact of GAS on cardiomyocyte phenotypes, heart, and mitochondrial structure and function. The effect of GAS on cardiac function and mitochondrial structure in patients undergoing cardiac surgery has been observed in clinical practice. MethodsThe effects of GAS on cardiac structure and function, mitochondrial structure, and expression of related molecules in an animal model of MIRI were evaluated using immunohistochemical staining, enzyme-linked immunosorbent assay (ELISA), transmission electron microscopy, western blotting, and gene sequencing. Its effects on the morphological, molecular, and functional phenotypes of cardiomyocytes undergoing H/R were observed using immunohistochemical staining, real-time quantitative PCR, and western blotting. ResultsGAS significantly reduces myocardial infarct size and improves cardiac function in MIRI mice in animal models and increases cardiomyocyte viability and reduces cardiomyocyte damage in cellular models. In clinical practice, myocardial injury was alleviated with better cardiac function in patients undergoing cardiac surgery after the application of GAS; improvements in mitochondria and autophagy activation were also observed. GAS primarily exerts cardioprotective effects through activation of the PINK1/Parkin pathway, which promotes mitochondrial autophagy to clear damaged mitochondria. ConclusionGAS can promote mitophagy and preserve mitochondria through PINK1/Parkin, thus indicating its tremendous potential as an effective perioperative myocardial protective agent.

Hypoxia-preconditioned WJ-MSC spheroid-derived exosomes delivering miR-210 for renal cell restoration in hypoxia-reoxygenation injury

BackgroundRecent advancements in mesenchymal stem cell (MSC) technology have paved the way for innovative treatment options for various diseases. These stem cells play a crucial role in tissue regeneration and repair, releasing local anti-inflammatory and healing signals. However, challenges such as homing issues and tumorigenicity have led to exploring MSC-exosomes as a promising alternative. MSC-exosomes have shown therapeutic potential in conditions like renal ischemia-reperfusion injury, but low production yields hinder their clinical use.MethodsTo address this limitation, we examined hypoxic preconditioning of Wharton jelly-derived MSCs (WJ-MSCs) 3D-cultured in spheroids on isolated exosome yields and miR-21 expression. We then evaluated their capacity to load miR-210 into HEK-293 cells and mitigate ROS production, consequently enhancing their survival and migration under hypoxia-reoxygenation conditions.ResultsMiR-210 overexpression was significantly induced by optimized culture and preconditioning conditions, which also improved the production yield of exosomes from grown MSCs. The exosomes enriched with miR-210 demonstrated a protective effect by improving survival, reducing apoptosis and ROS accumulation in damaged renal cells, and ultimately promoting cell migration.ConclusionThe present study underscores the possibility of employing advanced techniques to maximize the therapeutic attributes of exosomes produced from WJ-MSC spheroid for improved recovery outcomes in ischemia-reperfusion injuries.

P85α deficiency alleviates ischemia-reperfusion injury by promoting cardiomyocyte survival

Myocardial ischemia-reperfusion (I/R) injury is a prevalent cause of myocardial injury, involving a series of interconnected pathophysiological processes. However, there is currently no clinical therapy for effectively mitigating myocardial I/R injury. Here, we show that p85α protein levels increase in response to I/R injury through a comprehensive analysis of cardiac proteomics, and confirm this in the I/R-injured murine heart and failing human myocardium. Genetic inhibition of p85α in mice activates the Akt-GSK3β/Bcl-x(L) signaling pathway and ameliorates I/R-induced cardiac dysfunction, apoptosis, inflammation, and mitochondrial dysfunction. p85α silencing in cardiomyocytes alleviates hypoxia-reoxygenation (H/R) injury through activating the Akt-GSK3β/Bcl-x(L) signaling pathway, while its overexpression exacerbates the damage. Mechanistically, the interaction between MG53 and p85α triggers the ubiquitination and degradation of p85α, consequently enhancing Akt phosphorylation and ultimately having cardioprotective effects. Collectively, our findings reveal that substantial reduction of p85α and subsequently activated Akt signaling have a protective effect against cardiac I/R injury, representing an important therapeutic strategy for mitigating myocardial damage.

Nepetoidin B Alleviates Liver Ischemia/Reperfusion Injury via Regulating MKP5 and JNK/P38 Pathway.

Nepetoidin B (NB) has been reported to possess anti-inflammatory, antibacterial, and antioxidant properties. However, its effects on liver ischemia/reperfusion (I/R) injury remain unclear. In this study, a mouse liver I/R injury model and a mouse AML12 cell hypoxia reoxygenation (H/R) injury model were used to investigate the potential role of NB. Serum transaminase levels, liver necrotic area, cell viability, oxidative stress, inflammatory response, and apoptosis were evaluated to assess the effects of NB on liver I/R and cell H/R injury. Quantitative polymerase chain reaction (qPCR) and Western blotting were used to measure mRNA and protein expression levels, respectively. Molecular docking was used to predict the binding capacity of NB and mitogen-activated protein kinase phosphatase 5 (MKP5). The results showed that NB significantly reduced serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, liver necrosis, oxidative stress, reactive oxygen species (ROS) content, inflammatory cytokine content and expression, inflammatory cell infiltration, and apoptosis after liver I/R and AML12 cells H/R injury. Additionally, NB inhibited the JUN protein amino-terminal kinase (JNK)/P38 pathway. Molecular docking results showed good binding between NB and MKP5 proteins, and Western blotting results showed that NB increased the protein expression of MKP5. MKP5 knockout (KO) significantly diminished the protective effects of NB against liver injury and its inhibitory effects on the JNK/P38 pathway. NB exerts hepatoprotective effects against liver I/R injury by regulating the MKP5-mediated P38/JNK signaling pathway.

Tibetan-Origin Edible Chinese Herbal Prescription C18 Protects H9C2 Cardiomyocytes from Cobalt Chloride-induced Hypoxia Injury through the PI3K/AKT Signaling Pathway

Background Altitude sickness is often prone to occur during tourism or work in high-altitude areas. In China, traditional Tibetan medicines have a long history of preventing or treating altitude sickness, especially altitude hypoxia, which may lead to myocardial cell apoptosis and myocardial hypoxia-reoxygenation injury. Purpose This study investigated the effect of a Tibetan-origin edible Chinese herbal prescription (named C18) on protecting H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury and its potential mechanism. Materials and Methods In this study, a hypoxic injury model of H9C2 cardiomyocytes induced by cobalt chloride was established first. Then the cell viability, relevant antioxidant indicators malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and protein expression (hypoxia-inducible factor 1 alpha (HIF-1α), phosphoinositide 3-kinase (PI3K), phosphorylated protein kinase B (p-AKT)) were measured after pretreatment with or without C18. At last, the specific PI3K/AKT inhibitor LY294002 was applied to verify the antihypoxia signaling pathway. Results C18 could significantly promote normal H9C2 cardiomyocyte proliferation and inhibit apoptosis of hypoxic H9C2 cardiomyocytes, reduce the release of lactate dehydrogenase and MDA, and increase the levels of SOD and GSH-Px antioxidant enzymes. In addition, C18 could significantly downregulate the expression of HIF-1α protein and upregulate the expression of intracellular p-AKT. Moreover, these effects of C18 can be blocked by the specific PI3K/AKT inhibitor LY294002. Conclusion C18 protects H9C2 cardiomyocytes from cobalt chloride-induced hypoxia injury through the PI3K/AKT signaling pathway.

Regulating NCOA4-Mediated Ferritinophagy for Therapeutic Intervention in Cerebral Ischemia-Reperfusion Injury.

Ischemic stroke presents a global health challenge, necessitating an in-depth comprehension of its pathophysiology and therapeutic strategies. While reperfusion therapy salvages brain tissue, it also triggers detrimental cerebral ischemia-reperfusion injury (CIRI). In our investigation, we observed the activation of nuclear receptor coactivator 4 (NCOA4)-mediated ferritinophagy in an oxygen-glucose deprivation/reoxygenation (OGD/R) model using HT22 cells (P < 0.05). This activation contributed to oxidative stress (P < 0.05), enhanced autophagy (P < 0.05) and cell death (P < 0.05) during CIRI. Silencing NCOA4 effectively mitigated OGD/R-induced damage (P < 0.05). These findings suggested that targeting NCOA4-mediated ferritinophagy held promise for preventing and treating CIRI. Subsequently, we substantiated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway effectively regulated the NCOA4-mediated ferritinophagy, by applying the cGAS inhibitor RU.521 and performing NCOA4 overexpression (P < 0.05). Suppressing the cGAS-STING pathway efficiently curtailed ferritinophagy (P < 0.05), oxidative stress (P < 0.05), and cell damage (P < 0.05) of CIRI, while NCOA4 overexpression could alleviate this effect (P < 0.05). Finally, we elucidated the specific molecular mechanism underlying the protective effect of the iron chelator deferoxamine (DFO) on CIRI. Our findings revealed that DFO alleviated hypoxia-reoxygenation injury in HT22 cells through inhibiting NCOA4-mediated ferritinophagy and reducing ferrous ion levels (P < 0.05). However, the protective effects of DFO were counteracted by cGAS overexpression (P < 0.05). In summary, our results indicated that the activation of the cGAS-STING pathway intensified cerebral damage during CIRI by inducing NCOA4-mediated ferritinophagy. Administering the iron chelator DFO effectively attenuated NCOA4-induced ferritinophagy, thereby alleviating CIRI. Nevertheless, the role of the cGAS-STING pathway in CIRI regulation likely involves intricate mechanisms, necessitating further validation in subsequent investigations.

Panax quinquefolius saponins and panax notoginseng saponins attenuate myocardial hypoxia-reoxygenation injury by reducing excessive mitophagy.

Panax quinquefolius saponins (PQS) and Panax notoginseng saponins (PNS) are key bioactive compounds in Panax quinquefolius L. and Panax notoginseng, commonly used in the treatment of clinical ischemic heart disease. However, their potential in mitigating myocardial ischemia-reperfusion injury remains uncertain. This study aims to evaluate the protective effects of combined PQS and PNS administration in myocardial hypoxia/reoxygenation (H/R) injury and explore the underlying mechanisms. To investigate the involvement of HIF-1α/BNIP3 mitophagy pathway in the myocardial protection conferred by PNS and PQS, we employed small interfering BNIP3 (siBNIP3) to silence key proteins of the pathway. H9C2 cells were categorized into four groups: control, H/R, H/R + PQS + PNS, and H/R + PQS + PNS+siBNIP3. Cell viability was assessed by Cell Counting Kit-8, apoptosis rates determined via flow cytometry, mitochondrial membrane potential assessed with the JC-1 fluorescent probes, intracellular reactive oxygen species detected with 2',7'-dichlorodihydrofluorescein diacetate, mitochondrial superoxide production quantified with MitoSOX Red, and autophagic flux monitored with mRFP-GFP-LC3 adenoviral vectors. Autophagosomes and their ultrastructure were visualized through transmission electron microscopy. Moreover, mRNA and protein levels were analyzed via real-time PCR and Western blotting. PQS + PNS administration significantly increased cell viability, reduced apoptosis, lowered reactive oxygen species levels and mitochondrial superoxide production, mitigated mitochondrial dysfunction, and induced autophagic flux. Notably, siBNIP3 intervention did not counteract the cardioprotective effect of PQS + PNS. The PQS + PNS group showed downregulated mRNA expression of HIF-1α and BNIP3, along with reduced HIF-1α protein expression compared to the H/R group. PQS + PNS protects against myocardial H/R injury, potentially by downregulating mitophagy through the HIF-1α/BNIP3 pathway.

CircMIRIAF aggravates myocardial ischemia-reperfusion injury via targeting miR-544/WDR12 axis

Exploring and discovering novel circRNAs is one of the ways to develop innovative drugs for the diagnosis and treatment of myocardial ischemia-reperfusion injury (MI/RI). In the work, some dysregulated circRNAs were found by microarray screening analysis in AC16 cells, and hsa_circRNA_104852 named circMIRIAF was screened, which was up-regulated in AC16 cells damaged by hypoxia-reoxygenation injury (H/RI). The comprehensive analysis of ceRNA network revealed the potential relationship of circMIRIAF/miR-544/WDR12. Then, the results of interaction research confirmed that circMIRIAF acted as sponge of miR-544 to positively regulate WDR12 protein expression. Further, the validation results indicate that miR-544 silencing increased the expression of WDR12, and WDR12 activated Notch1 signal to aggravate H/RI of AC16 cells and MI/RI of mice via regulating oxidative stress and inflammation. Furthermore, silencing circMIRIAF caused the decreased circMIRIAF levels and the increased miR-544 levels in cardiomyocytes, while excessive miR-544 inhibited WDR12 expression to alleviate the disorder. On the contrary, excessive circMIRIAF increased WDR12 expression by adsorbing miR-544 to exacerbate H/RI in AC16 cells. In addition, circMIRIAF siRNA reversed the aggravation of H/RI in cells caused by WDR12 overexpression. Overall, circMIRIAF can serve as a drug target or treating MI/RI, and circMIRIAF could sponge miR-544 and enhance WDR12 expression to aggravate MI/RI, which may provide a novel therapeutic strategy for MI/RI treatment.

Dual-specificity phosphatase 26 protects against kidney injury caused by ischaemia-reperfusion through restraint of TAK1-JNK/p38-mediated apoptosis and inflammation of renal tubular epithelial cells

Dual-specificity phosphatase 26 (DUSP26) acts as a pivotal player in the transduction of signalling cascades with its dephosphorylating activity. Currently, DUSP26 attracts extensive attention due to its particular function in several pathological conditions. However, whether DUSP26 plays a role in kidney ischaemia-reperfusion (IR) injury is unknown. Aims of the current work were to explore the relevance of DUSP26 in kidney IR damage. DUSP26 levels were found to be decreased in renal tubular epithelial cells following hypoxia-reoxygenation (HR) and kidney samples subjected to IR treatments. DUSP26-overexpressed renal tubular epithelial cells exhibited protection against HR-caused apoptosis and inflammation, while DUSP26-depleted renal tubular epithelial cells were more sensitive to HR damage. Upregulation of DUSP26 in rat kidneys by infecting adenovirus expressing DUSP26 markedly ameliorated kidney injury caused by IR, while also effectively reducing apoptosis and inflammation. The mechanistic studies showed that the activation of transforming growth factor-β-activated kinase 1 (TAK1)-JNK/p38 MAPK, contributing to kidney injury under HR or IR conditions, was restrained by increasing DUSP26 expression. Pharmacological restraint of TAK1 markedly diminished DUSP26-depletion-exacebated effects on JNK/p38 activation and HR injury of renal tubular cells. The work reported a renal-protective function of DUSP26, which protects against IR-related kidney damage via the intervention effects on the TAK1-JNK/p38 axis. The findings laid a foundation for understanding the molecular pathogenesis of kidney IR injury and provide a prospective target for treating this condition.

Hydrogen Sulfide Exerted a Pro-Angiogenic Role by Promoting the Phosphorylation of VEGFR2 at Tyr797 and Ser799 Sites in Hypoxia-Reoxygenation Injury.

The protective effects of hydrogen sulfide (H2S) against ischemic brain injury and its role in promoting angiogenesis have been established. However, the specific mechanism underlying these effects remains unclear. This study is designed to investigate the regulatory impact and mechanism of H2S on VEGFR2 phosphorylation. Following expression and purification, the recombinant His-VEGFR2 protein was subjected to LC-PRM/MS analysis to identify the phosphorylation sites of VEGFR2 upon NaHS treatment. Adenovirus infection was used to transfect primary rat brain artery endothelial cells (BAECs) with the Ad-VEGFR2WT, Ad-VEGFR2Y797F, and Ad-VEGFR2S799A plasmids. The expression of VEGFR2 and recombinant Flag-VEGFR2, along with Akt phosphorylation, cell proliferation, and LDH levels, was assessed. The migratory capacity and tube-forming potential of BAECs were assessed using wound healing, transwell, and tube formation assays. NaHS notably enhanced the phosphorylation of VEGFR2 at Tyr797 and Ser799 sites. These phosphorylation sites were identified as crucial for mediating the protective effects of NaHS against hypoxia-reoxygenation (H/R) injury. NaHS significantly enhanced the Akt phosphorylation, migratory capacity, and tube formation of BAECs and upregulated the expression of VEGFR2 and recombinant proteins. These findings suggest that Tyr797 and Ser799 sites of VEGFR2 serve as crucial mediators of H2S-induced pro-angiogenic effects and protection against H/R injury.

Network pharmacology analysis and clinical efficacy of the traditional Chinese medicine Bu-Shen-Jian-Pi. Part2: Modulation of hypoxia, redox status, and mitochondrial protection ina neuroblastoma cell line, SH-SY5Y.

To examine the mitochondrial protective effects of icariin, naringenin, kaempferol, and formononetin, potentially active agents in Bu-Shen-Jian-Pi formula (BSJP) identified using network pharmacology analysis. Mitochondrial protection activity was determined using a hypoxia-reoxygenation in vitro model based on the neuroblastoma cell line SH-SY5Y and measurements of anti-ferroptotic activity. Icariin, naringenin, kaempferol, and formononetin showed mitochondrial protective activity involving diverse signaling pathways. The cytoprotective effects of formononetin depended on the inhibition of ferroptosis. Hypoxia-reoxygenation stimulation induced ferroptosis in SH-SY5Y cells. Ferroptosis is a key mechanism in nervous system diseases and is associated with hypoxia-reoxygenation injury. Naringenin and kaempferol were devoid of anti-ferroptotic activity. Evidence has been obtained showing that the core components: icariin, naringenin, kaempferol, and formononetin in BSJP formula have anti-hypoxic and mitochondrial protective activity of potential clinical importance in the treatment of amyotrophic lateral sclerosis and patients with symptoms of hypoxia.

Protecting cardiomyocytes from hypoxia-reoxygenation injury, empaglifozin and liraglutide alone or in combination?

Empagliflozin, a sodium-dependent glucose co-transporter 2 (SGLT2) inhibitor, and liraglutide, a GLP-1 receptor (GLP-1R) agonist, are commonly recognized for their cardiovascular benefits in individuals with type 2 diabetes (T2D). In prior studies, we have demonstrated that both drugs, alone or in combination, were able to protect cardiomyocytes from injury induced by diabetes. Mechanistic investigations also suggested that the cardioprotective effect may be independent of diabetes In this study, we utilized a hypoxia-reoxygenation (H/R) model to investigate the cardiovascular benefits of SGLT2 inhibitor empagliflozin and GLP-1 receptor (GLP-1R) agonist liraglutide, both alone and in combination, in the absence of T2D. Our hypothesis was that empagliflozin and liraglutide, either individually or in combination, would demonstrate cardioprotective properties against H/R-induced injury, with an additive and/or synergistic effect anticipated from combination therapy. In this study, the cardiac muscle cell line, HL-1 cells, were treated with vehicle, empagliflozin, liraglutide, or a combination of the two drugs. The cells were then subjected to a hypoxia-reoxygenation (H/R) protocol, consisting of 1 h of hypoxia followed by 24 h of reoxygenation. The effects of the treatments on cytotoxicity, oxidative stress, endothelial nitric oxide synthase (eNOS) activity, phospho-protein kinase C (PKC) beta and phospho-eNOS (Thr495) expression were subsequently evaluated at the end of the treatments. We found that H/R increased cytotoxicity and reduces eNOS activity, empagliflozin, liraglutide or combination treatment attenuated some or all of these effects with the combination therapy showing the greatest improvement. Empagliflozin, liraglutide or combination of these two have cardioprotective effect regardless of diabetes. Cardioprotective effects of SGLT2 inhibitor and GLP-1R agonist is additive and synergistic.