Melastoma dodecandrum lour. Protects against cerebral ischemia-reperfusion injury by ameliorating oxidative stress and endoplasmic reticulum stress.

ETHNOPHARMACOLOGICAL RELEVANCE: Melastoma dodecandrum Lour. (MD), a traditional Chinese medicine used by the She ethnic group, has been used to treat cerebral ischemia-reperfusion (CIR) injury due to its efficacy in promoting blood circulation and removing blood stasiss; however, the therapeutic effects and mechanisms of MD in treating CIR injury remain unclear. AIM: To investigate the protective effects of MD on CIR injury, in addition to its impact on oxidative stress, endoplasmic reticulum (ER) stress, and cell apoptosis. MATERIALS AND METHODS: The research was conducted using both cell experiments and animal experiments. The CCK-8 method, immunofluorescence staining, and flow cytometry were used to analyze the effects of MD-containing serum on oxygen-glucose deprivation/reperfusion (OGD/R)-induced PC12 cell viability, reactive oxygen species (ROS) clearance, anti-inflammatory, neuroprotection and inhibition of apoptosis. Furthermore, 2,3,5-Triphenyl tetrazolium chloride staining, hematoxylin and eosin staining, Nissl staining, and immunohistochemistry were used to detect infarct size, pathological changes, Nissl corpuscula and neuronal protein expression in middle cerebral artery occlusion (MCAO) rats. Polymerase chain reaction and Western Blotting were conducted in cell and animal experiments to detect the expression levels of ER stress-related genes and proteins. RESULTS: The MD extract enhanced the viability of PC12 cells under OGD/R modeling, reduced ROS and IL-6 levels, increased MBP levels, and inhibited cell apoptosis. Furthermore, MD improved the infarct area in MCAO rats, increased the number of Nissl bodies, and regulated neuronal protein levels including Microtubule-Associated Protein 2 (MAP-2), Myelin Basic Protein (MBP), Glial Fibrillary Acidic Protein (GFAP), and Neurofilament 200 (NF200). Additionally, MD could regulate the expression levels of oxidative stress proteins malondialdehyde (MDA), nitric oxide (NO), superoxide dismutase (SOD), and catalase (CAT). Both cell and animal experiments demonstrated that MD could inhibit ER stress-related proteins (GRP78, ATF4, ATF6, CHOP) and reduce cell apoptosis. CONCLUSION: This study confirmed that the therapeutic mechanism of the MD extract on CIR injury was via the inhibition of oxidative stress and the ER stress pathway, in addition to the inhibition of apoptosis.

Naoxintong capsule accelerates mitophagy in cerebral ischemia-reperfusion injury via TP53/PINK1/PRKN pathway based on network pharmacology analysis and experimental validation.

ETHNOPHARMACOLOGICAL RELEVANCE: The incidence and mortality of cerebrovascular diseases are increasing year by year. Cerebral ischemia-reperfusion injury (CIRI) is common in patients with ischemic stroke. Naoxintong (NXT) is composed of a variety of Chinese medicines and has the ability to treat CIRI. AIM OF THE STUDY: The aim of this study is to investigate whether NXT regulates mitophagy in CIRI based on network pharmacology analysis and experimental validation. MATERIALS AND METHODS: Oxygen and glucose deprivation/re-oxygenation (OGD/R, 2/22 h) model of PC12 cells and transient middle cerebral artery occlusion (tMCAO, 2/22 h) model of rats were established. Pharmacodynamic indicators include neurological deficit score, 2,3,5-triphenyte-trazoliumchloride (TTC) staining, hematoxylin-eosin (HE) staining and cell viability. Network pharmacology was used to predict pharmacological mechanisms. Pharmacological mechanism indexes include transmission electron microscopy (TEM), drug affinity responsive target stability (DARTS), cellular thermal shift assay (CETSA), immunohistochemistry (IHC), western blot (WB) and immunofluorescence (IF). Kevetrin (an agonists of p53) and pifithrin-α (an inhibitor of p53) used to detect the key role of p53 in mitophagy of NXT. RESULTS: NXT (1% serum containing NXT and 110 mg/kg) improved the damage of OGD/R PC12 cells and tMCAO rats, and this protective effect was related to the anti-oxidation and ability to promote mitophagy of NXT. NXT and pifithrin-α increased the expression of promoting-mitophagy targets (PINK1, PRKN and LC3B) and inhibited the expression of inhibiting-mitophagy targets (p52) via restraining p53, and finally accelerated mitophagy caused by CIRI. CONCLUSION: This study demonstrates that NXT promotes mitophagy in CIRI through restraining p53 and promoting PINK1/PRKN in vivo and in vitro.

Alpha B-crystallin Ameliorates Imbalance of Redox Homeostasis, Inflammation and Apoptosis in an Acute Lung Injury Model with Rats.

Objective: Ischemia-reperfusion (IR) of the aorta is a significant contributor to the development of postoperative acute lung damage after abdominal aortic surgery. The aim of the present study was to examine the effect of alpha B-crystallin, a small heat shock protein (known as HspB5), on lung injury induced by abdominal aortic IR in rats. Methods: Male Sprague-Dawley rats were divided into three groups: control, ischemia-reperfusion (IR, 90 min ischemia and 180 min reperfusion), and alpha B-crystallin +IR. Alpha B-crystallin (50 µg/100 g) was intraperitoneally administered 1 h before IR. Lung tissue samples were obtained for histological and biochemical analyses of oxidative stress and cytokine and apoptosis parameters in plasma, lung tissues, and bronchoalveolar lavage (BAL) fluid. Results: The levels of malondialdehyde, reactive oxygen species, total oxidant status, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1ß), nuclear factor kappa B (NFKß), caspase-9 (CASP-9), 8-hydroxy-2'-deoxyguanosine, total antioxidant status, superoxide dismutase, and interleukin-10 levels in lung tissues, plasma, and BAL fluid (p<0.05 versus control) increased in Aortic IR. However, alpha B-crystallin significantly reduced the lung tissue levels of oxidative, inflamatuvar, and apoptotic parameters in the plasma, lung tissues, and BAL fluid (p<0.05 versus aortic IR). Histopathological results showed that alpha B-crystallin ameliorated the morphological changes related to lung injury (p<0.001). Conclusion: Alpha B-crystallin substantially restored disrupted the redox balance, inflammation, and apoptotic parameters in rats exposed to IR. The cytoprotective effect of alpha B-crystallin on redox balance might be attributed to improved lung injury.

Deubiquitinase USP5 regulates RIPK1 driven pyroptosis in response to myocardial ischemic reperfusion injury.

BACKGROUND: Gasdermin D (GSDMD) mediated pyroptosis plays a significant role in the pathophysiology of myocardial ischemia/reperfusion (I/R) injury. However, the precise mechanisms regulating pyroptosis remain unclear. In the study, we aimed to investigate the underlying mechanism of pyroptosis in myocardial I/R injury. METHODS: In the present study, we analyzed the effects of USP5 on the RIPK1 kinase activity mediated pyroptosis in vitro after H/R (hypoxia/reoxygenation) and in vivo in a MI/R mouse model. TTC and Evan's blue dye, Thioflavin S and immunohistochemistry staining were performed in wild-type, RIPK1flox/flox Cdh5-Cre and USP5 deficiency mice. CMEC cells were transfected with si-USP5. HEK293T cells were transfected with USP5 and RIPK1 overexpression plasmid or its mutants. The levels of USP5, RIPK1, Caspase-8, FADD and GSDMD were determined by Western blot. Protein interactions were evaluated by immunoprecipitation. The protein colocalization in cells was monitored using a confocal microscope. RESULTS: In this study, our data demonstrate that RIPK1 is essential for limiting cardiac endothelial cell (CMEC) pyroptosis mediated by caspase-8 in response to myocardial I/R. Additionally, we investigate the role of ubiquitin-specific protease 5 (USP5) as a deubiquitinase for RIPK1. Mechanistically, USP5 interacts with RIPK1, leading to its deubiquitination and stabilization. CONCLUSIONS: These findings offer new insights into the role of USP5 in regulating RIPK1-induced pyroptosis.

First Experience With Catheter-Directed Thrombolysis for Massive Pulmonary Embolism at Teaching Hospital Jaffna, Sri Lanka: A Case Report.

Catheter-directed thrombolysis (CDT) is one of the modes of treatment for massive pulmonary embolism (PE). This case report shares the new experience of CDT for massive PE at Teaching Hospital Jaffna, Sri Lanka. A 54-year-old woman developed massive PE two days after a traumatic tibial fracture. She was hemodynamically unstable with hypotension and hypoxemia. The multidisciplinary team decided to go for CDT, administering alteplase. Follow-up imaging demonstrated complete thrombus resolution and significant clinical improvement. This case emphasizes the efficacy and safety of CDT for massive PE, particularly in patients at high risk for bleeding. Our experience at Teaching Hospital Jaffna accentuates the significance of individualized treatment strategies and the adoption of advanced techniques in resource-limited settings.

Assessment, Management and Quality of Care of Patients Presenting with Non-Traumatic Acute Chest Pain in the Emergency Room who had Acute Coronary Syndrome.

BACKGROUND: Non-traumatic Acute Chest pain (NTACP) is a common presentation in the emergency services of many hospitals and a key presenting symptom of acute coronary syndrome (ACS). However, there is a dearth of data on the system of care of ACS patients in our facilities. OBJECTIVE: Our objective was to evaluate the process of care of patients presenting with NTACP at a Tertiary Hospital emergency department (ED) in sub-Saharan Africa, using quality indicators of a universal chain of survival to identify any care gaps in the diagnosis and management of those with life-threatening ACS. METHODS: This was a retrospective cross-sectional study of adult patients ≥18 years of age, seen between July 2020 and June 2023 at the ED of the University College Hospital (UCH), Ibadan, Nigeria. We used this information to determine the frequency of ACS amongst those presenting with NTACP. From this subset, we assessed the main domains of quality indicators of the universal chain of survival in ACS care. These were, early symptom recognition and call for help; emergency medical service (EMS) evaluation and treatment; ED evaluation and treatment; and reperfusion therapy. RESULTS: We assessed a total of 4,306 patients who presented to the ED during the study period. Of these, 225 patients presented with NTACP. The mean ± SD age of these patients was 45.9 ± 18.4 years, with most between the ages of 40-49 years (20.9%) and males (50.7%). More than 80% of the patients presented to ED 12 hours after the onset of chest pain. Only 4.0% presented via an ambulance service which offered no prehospital guideline-directed medical treatment, and 70.7% were non-referred patients. Only 37.3%, 57.8%, 12.4%, and 8.9% had ECG, chest x-ray, echocardiography, and cardiac enzyme evaluation, respectively, in the acute phase of care. There were 29 (12.9%) patients who had a diagnosis of ACS. Two (6.9%) had medical revascularization with thrombolytic agents, while 8 (27.6%) and 19 (65.5%) were referred for primary and secondary PCI respectively. CONCLUSION: We found a high burden of late presentation and significant barriers to recommended guideline management of ACS patients, presenting with clinical features of NTACP in our hospital's ED.

CONTEXTE: La douleur thoracique aiguë non traumatique (NTACP) est une présentation courante dans les services d'urgence de nombreux hôpitaux et un symptôme clé du syndrome coronarien aigu (SCA). Cependant, il y a peu de données sur le système de soins des patients atteints de SCA dans nos établissements. OBJECTIF: Notre objectif était d'évaluer le processus de prise en charge des patients présentant une NTACP dans un service d'urgence d'un hôpital tertiaire en Afrique subsaharienne, en utilisant des indicateurs de qualité de la chaîne universelle de survie pour identifier les lacunes dans le diagnostic et la gestion de ceux présentant un SCA potentiellement mortel. MÉTHODES: Il s'agit d'une étude rétrospective transversale sur des patients adultes âgés de ≥18 ans, vus entre juillet 2020 et juin 2023 aux urgences de l'Hôpital Universitaire de l'Université d'Ibadan (UCH), Nigeria. Nous avons utilisé ces informations pour déterminer la fréquence du SCA parmi ceux présentant une NTACP. À partir de ce sous-ensemble, nous avons évalué les principaux domaines des indicateurs de qualité de la chaîne universelle de survie dans les soins du SCA. Ces domaines comprenaient la reconnaissance précoce des symptômes et l'appel à l'aide, l'évaluation et le traitement par les services médicaux d'urgence (SMU), l'évaluation et le traitement aux urgences, et la thérapie de reperfusion. RÉSULTATS: Nous avons évalué un total de 4 306 patients qui se sont présentés aux urgences au cours de la période d'étude. Parmi eux, 225 patients présentaient une NTACP. L'âge moyen ± écart-type de ces patients était de 45,9 ± 18,4 ans, la plupart ayant entre 40 et 49 ans (20,9%) et étant des hommes (50,7%). Plus de 80% des patients se sont présentés aux urgences 12 heures après le début de la douleur thoracique. Seulement 4,0% sont arrivés via un service d'ambulance qui n'a pas offert de traitement médical préhospitalier dirigé par des lignes directrices, et 70,7% étaient des patients non référés. Seuls 37,3%, 57,8%, 12,4% et 8,9% ont eu un ECG, une radiographie thoracique, une échocardiographie et une évaluation des enzymes cardiaques, respectivement, dans la phase aiguë des soins. Vingt-neuf patients (12,9%) ont été diagnostiqués avec un SCA. Deux (6,9%) ont subi une revascularisation médicale avec des agents thrombolytiques, tandis que 8 (27,6%) et 19 (65,5%) ont été référés pour une ICP primaire et secondaire, respectivement. CONCLUSION: Nous avons constaté une forte prévalence de présentation tardive et des obstacles significatifs à la gestion recommandée par les lignes directrices des patients atteints de SCA, se présentant avec des caractéristiques cliniques de NTACP dans les urgences de notre hôpital. MOTS CLÉS: Qualité des soins, Douleur thoracique non traumatique, Syndrome coronarien aigu, Troponines, Reperfusion, Intervention coronarienne percutanée, Département/salle d'urgence, Protocoles de diagnostic, Assurance santé.

Naringenin alleviates intestinal ischemia/reperfusion injury by inhibiting ferroptosis via targeting YAP/STAT3 signaling axis.

BACKGROUND: Intestinal ischemia/reperfusion injury (IRI) is a significant clinical emergency, and investigating novel therapeutic approaches and understanding their underlying mechanisms is essential for improving patient outcomes. Naringenin (Nar), a flavanone present in tomatoes and citrus fruits, is frequently consumed in the human diet and recognized for having immunomodulatory, anti-inflammatory, and antioxidant properties. Despite Nar being able to alleviate intestinal IRI, the exact molecular mechanisms remain elusive. PURPOSE: To investigate Nar's protective properties on intestinal IRI and elucidate the mechanisms, a comprehensive approach that combines network pharmacology analysis with experimental verification in vitro and in vivo was adopted. METHODS: The oxygen-glucose deprivation/reoxygenation (OGD/R) model in IEC-6 cells and a murine model of intestinal IRI were used. Nar's effects on intestinal IRI were assessed through histological analysis using H&E staining and tight junction (TJ) protein expression. Ferroptosis-related parameters, including iron levels, superoxide dismutase (SOD), glutathione (GSH), reactive oxygen species (ROS), malondialdehyde (MDA), and mitochondrial morphology, were analyzed. Network pharmacology was utilized to predict the pathways through which Nar exerts its anti-ferroptosis effects. Further mechanistic insights were obtained through si-RNA transfection, YAP inhibitor (verteporfin, VP) treatment, ferroptosis inhibitor (Ferrostatin-1) and ferroptosis inducer (Erastin) application, co-immunoprecipitation (Co-IP) and Western blotting. RESULTS: Our results revealed that pretreatment with Nar significantly mitigated intestinal tissue damage and improved gut barrier function, as evidenced by increased TJ proteins (ZO-1 and Occludin). Nar reduced iron, MDA, and ROS, while it increased GSH and SOD levels. Additionally, Nar alleviated mitochondrial damage in mice. Nar treatment increased GPX4 and SLC7A11, while decreasing ACSL4 levels both in vivo and in vitro. Network pharmacology analysis suggested that Nar may target the Hippo signaling pathway. Notably, YAP, a key transcriptional co-activator within the Hippo pathway, was downregulated in intestinal IRI mice and OGD/R-induced IEC-6 cells. Nar pretreatment activated YAP, thereby augmenting anti-ferroptosis effects. The inhibition of YAP activation by VP or YAP knockdown increased p-STAT3 expression, thereby diminishing Nar's efficacy. Co-IP and immunofluorescence studies confirmed the interaction between YAP and STAT3. CONCLUSION: This study shows that Nar can inhibit ferroptosis in intestinal IRI via activating YAP, which in turn suppresses STAT3 phosphorylation, thereby unveiling a novel mechanism and supporting Nar's potential to be a promising therapeutic agent for intestinal IRI.

Nrf2 inhibits M1 macrophage polarization to ameliorate renal ischemia-reperfusion injury through antagonizing NF-κB signaling.

Renal ischemia-reperfusion injury (IRI) is a condition that arises from a sudden interruption of the blood flow to the kidney for a period of time followed by restoration of the blood supply. This process contributes to acute kidney injury (AKI), increases morbidity and mortality, and is a major risk factor for chronic kidney disease (CKD). Nuclear factor erythroid-derived 2-like 2 (Nrf2) has been shown to exhibit strong anti-oxidative and anti-inflammatory effects, which are reciprocally regulated by the pro-inflammatory actions of nuclear factor-kappa B (NF-κB) signaling. In this study, we established a model of AKI caused by renal IRI in mice lacking the Nrf2 gene (KO-Nrf2) and mice pre-injected with ML385 (Nrf2 inhibitor). In addition, LPS- or IL-4-induced M1- or M2-type polarized macrophages (RAW264.7), respectively, were also treated with Nrf2 activation and inhibition. The results demonstrated a more pronounced activation of the NF-κB signaling pathway in the Nrf2 inhibition model, accompanied by a more severe inflammatory effect. In cultured macrophages and renal IRI mice, Nrf2 inhibition activated M1 macrophage polarization, thereby increasing the release of proinflammatory cell factors (iNOS and TNF-α) and aggravating renal IRI. Notably, the inhibitory effect of Nrf2 on M1 macrophage polarization was related to the downregulation of the NF-κB signaling pathway activity, resulting in partial relief of renal IRI. Consequently, our findings indicated that Nrf2 inhibits M1 macrophage polarization to ameliorate renal IRI through antagonizing NF-κB signaling. Targeted activation of Nrf2 may be one of the important strategies for renal IRI treatment.

Stroke: Evolution of newer treatment modalities for acute ischemic stroke.

Acute ischemic stroke is one of the leading causes of morbidity and mortality worldwide. Restoration of cerebral blood flow to affected ischemic areas has been the cornerstone of therapy for patients for eligible patients as early diagnosis and treatment have shown improved outcomes. However, there has been a paradigm shift in the management approach over the last decade, and with the emphasis currently directed toward including newer modalities such as neuroprotection, stem cell treatment, magnetic stimulation, anti-apoptotic drugs, delayed recanalization, and utilization of artificial intelligence for early diagnosis and suggesting algorithm-based management protocols.

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.

Cardiovascular events in crush syndrome: on-site therapeutic strategies and pharmacological investigations.

Crush syndrome often occurs after severe crush injury caused by disasters or accidents, and is associated with high mortality and poor prognosis. Cardiovascular complications, such as cardiac arrest, hypovolemic shock, and hyperkalemia-related cardiac dysfunction, are the primary causes of on-site death in crush syndrome. Prehospital evaluation, together with timely and correct treatment, is of great benefit to crush syndrome patients, which is difficult in most cases due to limited conditions. Based on current data and studies, early fluid resuscitation remains the most important on-site treatment for crush syndrome. Novel solutions and drugs used in fluid resuscitation have been investigated for their effectiveness and benefits. Several drugs have proven effective for the prevention or treatment of cardiovascular complications in crush syndrome, such as hypovolemic shock, hyperkalemia-induced cardiac complications, myocardial ischemia/reperfusion injury, ventricular dysfunction, and coagulation disorder experimentally. Moreover, these drugs are beneficial for other complications of crush syndrome, such as renal dysfunction. In this review, we will summarize the existing on-site treatments for crush syndrome and discuss the potential pharmacological interventions for cardiovascular complications to provide clues for clinical therapy of crush syndrome.

Ultra-Small Copper-Based Multienzyme-Like Nanoparticles Protect Against Hepatic Ischemia-Reperfusion Injury Through Scavenging Reactive Oxygen Species in Mice.

Hepatic ischemia-reperfusion injury (IRI) is a severe complication that occurs in the process of liver transplantation, hepatectomy, and other end-stage liver disease surgery, often resulting in the failure of surgery operation and even patient death. Currently, there is no effective way to prevent hepatic IRI clinically. Here, it is reported that the ultra-small copper-based multienzyme-like nanoparticles with catalase-like (CAT-like) and superoxide dismutase-like (SOD-like) catalytic activities significantly scavenge the surge-generated endogenous reactive oxygen species (ROS) and effectively protects hepatic IRI. Density functional theory calculations confirm that the nanoparticles efficiently scavenge ROS through their synergistic effects of the ultra-small copper SOD-like activity and manganese dioxides CAT-like activity. Furthermore, the results show that the biocompatible CMP NPs significantly protected hepatocytes from IRI in vitro and in vivo. Importantly, their therapeutic effect is much stronger than that of N-acetylcysteamine acid (NAC), an FDA-approved antioxidative drug. Finally, it is demonstrated that the protective effects of CMP NPs on hepatic IRI are related to suppressing inflammation and hepatocytic apoptosis and maintaining endothelial functions through scavenging ROS in liver tissues. The study can provide insight into the development of next-generation nanomedicines for scavenging ROS.

Ozone therapy mitigates parthanatos after ischemic stroke.

BACKGROUND: Stroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia-reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism. METHODS: Hydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. RESULTS: The findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos. CONCLUSIONS: These findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Loss of Nr4a1 ameliorates endothelial cell injury and vascular leakage in lung transplantation from circulatory-death donor.

BACKGROUND: Ischemia-reperfusion injury (IRI) stands as a major trigger for primary graft dysfunction (PGD) in lung transplantation (LTx). Especially in LTx from donation after cardiac death (DCD), effective control of IRI following warm ischemia (WIRI) is crucial to prevent PGD. This study aimed to identify the key factors affecting WIRI in LTx from DCD. METHODS: Previously reported RNA-sequencing dataset of lung WIRI was reanalyzed to identify nuclear receptor subfamily 4 group A member 1 (NR4A1) as the immediate early gene for WIRI. Dynamics of NR4A1 expression were verified using a mouse hilar clamp model. To investigate the role of NR4A1 in WIRI, a mouse model of LTx from DCD was established using Nr4a1 knockout (Nr4a1-/-) mice. RESULTS: NR4A1 was located around vascular cells, and its protein levels in the lungs increased rapidly and transiently during WIRI. LTｘ from Nr4a1-/- donors significantly improved pulmonary graft function compared to wild-type donors (P < 0.001). Histological analysis showed decreased microvascular endothelial cell death (P = 0.007), neutrophil infiltration (P < 0.001), and albumin leakage (P < 0.001). Evans blue permeability assay demonstrated maintained pulmonary microvascular barrier integrity in grafts from Nr4a1-/- donors, correlating with diminished pulmonary edema (P < 0.001). However, NR4A1 did not significantly affect the inflammatory response during WIRI, and IRI was not suppressed when a wild-type donor lung was transplanted into the Nr4a1-/- recipient. CONCLUSIONS: Donor NR4A1 plays a specialized role in the positive regulation of endothelial cell injury and microvascular hyperpermeability. These findings demonstrate the potential of targeting NR4A1 interventions to alleviate PGD and improve outcomes in LTx from DCD.

Correlation between prognosis and peripheral blood levels of NLRP3 and triglyceride-glucose index after myocardial ischemia-reperfusion injury.

OBJECTIVE: We aim to investigate the association between prognosis and outcomes following myocardial ischemia-reperfusion injury, as well as peripheral blood levels of NLRP3 and the triglyceride-glucose index (TyG). METHODS: A total of 100 patients who underwent emergency coronary intervention following myocardial infarction confirmed by coronary angiography at our hospital between October 2021 and May 2023 were included in this study. Patients were stratified into two groups based on their prognoses: the control group (n = 73), which did not experience new myocardial infarctions or require hospitalization for heart failure or suffer sudden cardiac death post-interventional treatment; and the observation group (n = 27), which experienced one or more cardiovascular events post-treatment. Patient demographics were obtained from clinical records while biochemical analyses assessed peripheral blood triglycerides, blood glucose levels, and TyG index. Additionally, ELISA measurements determined levels of NLRP3 as well as inflammatory factors IL-6, TNF-α, and CRP in peripheral blood samples. Cardiac function was evaluated according to NYHA standards. Univariable Cox regression analysis identified factors influencing patient prognosis while Pearson correlation analysis examined relationships among prognosis, outcomes following myocardial ischemia-reperfusion injury, TyG index, and peripheral blood NLRP3. RESULTS: No significant differences were observed in the general characteristics between the two patient groups (P > 0.05). However, the observation group exhibited higher levels of peripheral blood triglycerides, blood glucose, and TyG index compared to the control group (P < 0.05). Additionally, levels of NLRP3 and inflammatory factors IL-6, TNF-α, and CRP were elevated in the observation group compared to the control group (P < 0.05). Cardiac function impairment was more pronounced in the observation group (P < 0.05). Notably, TyG index and peripheral blood NLRP3 demonstrated higher risk ratios compared to other biomarkers (P < 0.05), indicating their significance in prognosis and outcomes. Elevated levels of NLRP3 and TyG index were associated with poorer recovery of cardiac function, increased rehospitalization rates, and higher mortality (P < 0.05). CONCLUSION: Elevated NLRP3 levels and an increased TyG index are strongly associated with impaired cardiac function and heightened risk of cardiovascular events. These findings suggest that these biomarkers may serve as crucial prognostic indicators following myocardial ischemia-reperfusion injury.

A gradient model of renal ischemia reperfusion injury to investigate renal interstitial fibrosis.

Background: The progression from acute kidney injury to chronic kidney disease poses a significant health challenge. Nonetheless, a constraint in existing animal models of renal ischemia/reperfusion (I/R) injury is the necessity for a severe injury, almost reaching a life-threatening level, to trigger the subsequent onset of renal fibrosis. Hence, we explored an adapted gradient approach to induce I/R injury, aiming to promote the progression of renal fibrosis while preserving the overall normal functioning of the kidney. Methods: In each group, 6-8 male C57BL/6 mice were used for model construction, with all undergoing sodium pentobarbital anesthesia and left kidney removal. Subsequently, a silk thread was passed beneath the lower renal branch, elevating the right kidney under a 20-g weight's tension via a pulley system for durations of 30, 40, or 60 min. Afterwards, we lowered the kidney, sutured the wound, and administered intraperitoneal saline. Mice in different groups were euthanized following reperfusion for 1, 3, 7, or 28 days. Results: We observed a complete cessation of blood flow in the lower pole, while an incomplete cessation in the upper pole in the elevated kidney. Significant renal impairment was evident on day 1 with a 60min ischemic period (187.0 ± 65.3 vs 17.9 ± 4.8 µmol/L serum creatinine in normal; p < .001), but not with 30 or 40min. On day 1, tubular necrosis and hyaline cast formation was evident in both lower and upper poles. On day 3, renal function returned to normal and remained normal through day 28. Histologic damage resolved in the upper pole over days 3 to 7, resulting in normal histology on day 28. By contrast, there was sustained tubular damage tubular in the lower pole on days 3 and 7, which failed to resolve and led to significant renal fibrosis by day 28. Conclusion: We created a model demonstrating clinically "silent" renal fibrosis.

PCSK9 inhibitor attenuates cardiac fibrosis in reperfusion injury rat by suppressing inflammatory response and TGF-ß1/Smad3 pathway.

Progressive cardiac fibrosis, a hallmark of heart failure, remains poorly understood regarding Proprotein convertase subtilisin/kexin type 9 (PCSK9) 's role. This study aims to elucidate PCSK9's involvement in cardiac fibrosis. After ischemia/reperfusion (I/R) injury surgery in rats, PCSK9 inhibitors were used to examine their effects on the transforming growth factor-ß1 (TGF-ß1)/small mother against decapentaplegic 3 (Smad3) pathway and inflammation. Elevated PCSK9, TGF-ß1, and Smad3 levels were observed in cardiac tissues post-I/R injury, indicating fibrosis. PCSK9 inhibition reduced pro-fibrotic protein expression, protecting the heart and mitigating I/R-induced damage and fibrosis. Additionally, it ameliorated cardiac inflammation and reduced post-myocardial infarction (MI) size, improving cardiac function and slowing heart failure progression. PCSK9 inhibitors significantly attenuate myocardial fibrosis induced by I/R via the TGF-ß1/Smad3 pathway.

Pharmacological upregulation of macrophage-derived itaconic acid by pubescenoside C attenuated myocardial ischemia-reperfusion injury.

INTRODUCTION: Myocardial ischemia-reperfusion injury (MIRI) remains a prevalent clinical challenge globally, lacking an ideal therapeutic strategy. Macrophages play a pivotal role in MIRI pathophysiology, exhibiting dynamic inflammatory and resolutive functions. Macrophage polarization and metabolism are intricately linked to MIRI, presenting potential therapeutic targets. Pubescenoside C (PBC) from Ilex pubescens showed significantly anti-inflammatory effects, however, the effect of PBC on MIRI is unknown. OBJECTIVES: This study aimed to assess the cardioprotective effects of PBC against MIRI and elucidate the underlying mechanisms. METHODS: Sprague-Dawley rats, H9c2 and RAW264.7 macrophages were used to establish the in vitro and in vivo models of MIRI. TTC/Evans blue staining, immunohistochemical staining, metabonomics analysis, chemical probe, surface plasmon resonance (SPR), co-immunoprecipitation (CO-IP) assays were used for pharmacodynamic and mechanism study. RESULTS: PBC administration effectively reduced myocardial infarct size, decreased ST-segment elevation, and lowered CK-MB levels, concurrently promoting macrophage M2 polarization in MIRI. Furthermore, PBC-treated macrophages and their conditioned culture medium attenuated the apoptosis of H9c2 cells induced by oxygen-glucose deprivation/reoxygenation (OGD/R). Metabonomics analysis revealed that PBC increased the production of itaconic acid (ITA) and malic acid (MA) in macrophages, which conferred protection against OGD/R injury in H9c2 cells. Mechanistic investigations indicated that ITA exerted its effects by covalently modifying pyruvate kinase M2 (PKM2) at Cys474, Cys424, and Lys151, thereby facilitating PKM2's mitochondrial translocation and enhancing the PKM2/Bcl2 interaction, subsequently leading to decreased degradation of Bcl2. SPR assays further revealed that PBC bound to HSP90, facilitating the interaction between HSP90 and GSK3ß and resulting in the inactivation of GSK3ß activity and upregulation of key metabolic enzymes for ITA and MA production (Acod1 and Mdh2). CONCLUSION: PBC alleviates MIRI-induced cardiomyocyte apoptosis by modulating the HSP90/ITA/PKM2 axis. Furthermore, pharmacological upregulation of ITA emerges as a promising therapeutic approach for MIRI, hinting at PBC's potential as a candidate drug for MIRI therapy.