Collaterals and stroke reperfusion: Too few leads to too much.

Adequate reperfusion after ischemic stroke is a major determinant of functional outcome yet remains unpredictable and insufficient for most survivors. In this issue of Neuron, Binder et al.1 identify leptomeningeal collaterals (LMCs) in mice and human patients as a key factor in regulating reperfusion and hemorrhagic transformation following stroke.

Asystolic donor warm ischemia time is associated with development of postreperfusion syndrome in donation after circulatory death liver transplant.

BACKGROUND: Individual events during donation after circulatory death (DCD) procurement, such as hypotensive or hypoxic warm ischemia, or circulatory arrest are all a part of donor warm ischemia time (dWIT), and may have differing effects on the outcome of the liver graft. This study aimed to identify risk factors for postreperfusion syndrome (PRS), a state of severe hemodynamic derangement following graft reperfusion, and its impact on DCD liver transplantation (LT) outcomes. METHODS: This was a retrospective analysis using 106 DCD LT. Detailed information for events during procurement (withdrawal of life support; systolic blood pressure < 80 mmHg; oxygen saturation < 80%; circulatory arrest; aortic cold perfusion) and their association with the development of PRS were examined using logistic regression. RESULTS: The overall incidence of PRS was 26.4%, occurring in 28 patients. Independent risk factors for PRS were asystolic dWIT (odds ratio (OR) 3.65, 95% confidence interval (CI) 1.38-9.66) and MELD score (OR 1.06, 95% CI 1.01-1.10). Total bilirubin was significantly higher in the PRS group at postoperative day (POD) 1 (p = .02; 5.2 mg/dL vs. 3.4 mg/dL), POD 3 (p = .049; 4.5 mg/dL vs. 2.8 mg/dL), and POD 7 (p = .04; 3.1 mg/dL vs. 1.9 mg/dL). Renal replacement therapy after LT was more likely to be required in the PRS group (p = .01; 48.2% vs. 23.1%). CONCLUSION: Asystolic dWIT is a risk factor for the development of PRS in DCD LT. Our results suggest that asystolic dWIT should be considered when selecting DCD liver donors.

Two surgical strategies (early carotid reperfusion vs. Central aortic repair-first) of acute type a aortic dissection complicated with cerebral malperfusion syndrome: a meta-analysis and systematic review.

OBJECTIVE: Cerebral malperfusion (CM) is a common comorbidity in acute type A aortic dissection (ATAAD), which is associated with high mortality and poor neurological prognosis. This meta-analysis investigated the surgical strategy of ATAAD patients with CM, aiming to compare the difference in therapeutic effectiveness between the central repair-first and the early reperfusion-first according to clinical outcomes. METHODS: The meta-analysis and systematic review was conducted based on studies sourced from the PubMed, Embase, and Cochrane literature database, in which cases of ATAAD with CM underwent surgical repair were included. Data for baseline characteristics, mortality, survival were extracted, and risk ratio (RR) values and the pooled mortality were calculated. RESULTS: A total of 17 retrospective studies were analyzed, including 1010 cases of ATAAD with CM underwent surgical repair. The pooled early mortality in early reperfusion group was lower (8.1%; CI, 0.02 to 0.168) than that in the central repair group (16.2%; CI, 0.115 to 0.216). The pooled long-term mortality was 7.9% in the early reperfusion cohort and 17.4% the central repair-first cohort, without a statistically significant heterogeneity (I [2] = 51.271%; p = 0.056). The mean time of symptom-onset-to-the-operation-room in all the reports was 8.87 ± 12.3 h. CONCLUSION: This meta-analysis suggested that early reperfusion-first may achieved better outcomes compared to central repair-first in ATAAD patients complicated with CM to some extent. Early operation and early restoration of cerebral perfusion may reduce the occurrence of some neurological complications. TRIAL REGISTRATION: The meta-analysis was registered in the International Prospective Register of Systematic Reviews database (No. CRD CRD42023475629) on Nov. 8th, 2023.

Time­dependent changes in blood cells, NIHSS and mRS according to reperfusion treatment type in stroke patients who developed hemorrhagic complication.

Hemorrhagic complications may be seen following reperfusion therapy with rtPA and/or thrombectomy after acute ischemic stroke (AIS). Neutrophils, lymphocytes, and platelets have important roles in the inflammatory and immune responses that develop in these patients. We investigated time­dependent changes in blood cells, NIHSS and mRS values according to type of reperfusion therapy in AIS patients who developed cerebral hemorrhage. In AIS patients who underwent rtPA and/or thrombectomy and developed cerebral hemorrhage within the first 24 hours after treatment, leukocyte, neutrophil, lymphocyte, platelet counts and their ratios were recorded on admission, 1st, 3rd, and 7th days. NIHSS values on admission, 3rd days and mRS values on admission, discharge, and the 3rd month were recorded. These values were compared according to the type of reperfusion therapy. Out of 436 AIS patients, rtPA was applied in 50.5%, thrombectomy in 28.2%, and rtPA+thrombectomy in 21.3%. Hemorrhage developed in 25.5% of the patients. Patients treated with thrombectomy had a greater rate of cerebral hemorrhage. Pre­stroke mRS values were lower in all therapy types than mRS scores at discharge and the 3rd month. The NIHSS scores did not differ significantly in 3 days. Depending on the type of reperfusion treatment, there are a few time­dependent significant changes observed in the blood cell counts and ratios. In conclusion, there is a relation between the type of reperfusion therapy and the time­dependent changes in blood cells and ratios as well as mRS scores among AIS patients who have undergone rtPA and/or thrombectomy and developed cerebral hemorrhage.

Dynamically changed HSP70 after reperfusion following cerebral infarction in human and rats: correlation with p38 MAPK.

We aimed to clarify the correlation between dynamic change of blood HSP70 and the prognosis of thrombolysis in human and rats, so as to explain the neuroprotection and early warning role of HSP70 in cerebral ischemia-reperfusion. Forty-two patients with acute ischemic stroke were divided into two groups according to the time from onset to thrombolytic therapy: 0 h-3 h (27 patients) and 3-4.5 h group (15 patients). The level of HSP70 in serum before and after thrombolysis was detected by ELISA. Furthermore, a rat model was also used to mimic the ischemic stroke and reperfusion. Peripheral blood of rat samples was collected to detect the level of HSP70 using Elisa. Several signal proteins from MAPK signaling pathway including JNK, p38, ERK (p42/44) were detected at different time points by Western blot of brain tissue. Patients who underwent thrombolytic therapy within 0-3 h had the highest HSP70 level at 1 h after thrombolysis. The higher HSP70 after thrombolysis, the better the patient prognosis. NIHSS scores showed HSP70 was positively correlated with cerebral ischemia. The levels of ERK family (p42/44 MAPK) and p-JNK were decreased gradually along with the time suffering cerebral ischemia. P-ERK, JNK, p-p38 had dynamic changes with increased ischemic time in the middle cerebral artery occlusion model. Dynamic change of HSP70 level in blood may be a biological index that reflects the functional condition of cell survival for cerebral ischemia and estimating the prognostic conditions. Importantly, HSP70 levels in blood were positively correlated with the p38 MAPK pathway in brain tissue.

Resveratrol protects cardiomyocytes against ischemia/reperfusion-induced ferroptosis via inhibition of the VDAC1/GPX4 pathway.

The present study aimed to explore how resveratrol (Res) confers myocardial protection by attenuating ferroptosis. In vivo and in vitro myocardial ischemia/reperfusion injury (MIRI) models were established, with or without Res pretreatment. The results showed that Res pretreatment effectively attenuated MIRI, as evidenced by increased cell viability, reduced lactate dehydrogenase activity, decreased infarct size, and maintained cardiac function. Moreover, Res pretreatment inhibited MIRI-induced ferroptosis, as shown by improved mitochondrial integrity, increased glutathione level, decreased prostaglandin-endoperoxide synthase 2 level, inhibited iron overload, and abnormal lipid peroxidation. Of note, Res pretreatment decreased or increased voltage-dependent anion channel 1/glutathione peroxidase 4 (VDAC1/GPX4) expression, which was increased or decreased via anoxia/reoxygenation (A/R) treatment, respectively. However, the overexpression of VDAC1 via pAd/VDAC1 and knockdown of GPX4 through Si-GPX4 reversed the protective effect of Res in A/R-induced H9c2 cells, whereas the inhibition of GPX4 with RSL3 abolished the protective effect of Res on mice treated with ischemia/reperfusion.Interestingly, knockdown of VDAC1 by Si-VDAC1 promoted the protective effect of Res on A/R-induced H9c2 cells and the regulation of GPX4. Finally, the direct interaction between VDAC1 and GPX4 was determined using co-immunoprecipitation. In conclusion, Res pretreatment could protect the myocardium against MIRI-induced ferroptosis via the VDAC1/GPX4 signaling pathway.

Long term outcome after endovascular treatment for large ischemic core acute stroke is associated with hypoperfusion intensity ratio and onset-to-reperfusion time.

BACKGROUND: Endovascular treatment (EVT) is effective for large vessel occlusion (LVO) stroke with smaller volumes of CT perfusion (CTP)-defined core. However, the influence of perfusion imaging during thrombectomy on the functional outcomes of patients with large ischemic core (LIC) stroke at both early and late time windows is uncertain in real-world practice. METHOD: A retrospective analysis was performed on 99 patients who underwent computed tomography angiography (CTA) and CT perfusion (CTP)-Rapid Processing of Perfusion and Diffusion (RAPID) before EVT and had a baseline ischemic core ≥ 50 mL and/or Alberta Stroke Program Early CT Score (ASPECTS) score of 0-5. The primary outcome was the three-month modified Rankin Scale (mRS) score. Data were analyzed by binary logistic regression and receiver operating characteristic (ROC) curves. RESULTS: A fair outcome (mRS, 0-3) was found in 34 of the 99 patients while 65 had a poor prognosis (mRS, 4-6). The multivariate logistic regression analysis showed that onset-to-reperfusion (OTR) time (odds ratio [OR], 1.004; 95% confidence interval [CI], 1.001-1.007; p = 0.008), ischemic core (OR, 1.066; 95% CI, 1.024-1.111; p = 0.008), and the hypoperfusion intensity ratio (HIR) (OR, 70.898; 95% CI, 1.130-4450.152; p = 0.044) were independent predictors of outcome. The combined results of ischemic core, HIR, and OTR time showed good performance with an area under the ROC curve (AUC) of 0.937, significantly higher than the individual variables (p < 0.05) using DeLong's test. CONCLUSIONS: Higher HIR and longer OTR time in large core stroke patients were independently associated with unfavorable three-month outcomes after EVT.

Intracoronary microcatheter indwelling for continuous pumping of low-dose thrombolytic drugs: A new approach to reperfusion in acute myocardial infarction.

Reperfusion therapy of acute myocardial infarction (AMI) refers to physical or chemical recanalization and restoration of blood flow to an occluded coronary artery, and current techniques for reperfusion therapy include intravenous thrombolysis, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). The number of patients receiving emergency CABG in the real world is decreasing due to the disadvantages of CABG and the improvement in PCI procedures. Thrombolytic therapy has some disadvantages such as low recanalization rate, high risk of reocclusion and bleeding, and short time window. On the other hand, intracoronary interventional therapy may meet the requirements of "early, complete and persistent" patency of coronary arteries at different time points. However, in the emergency PCI, although thrombus aspiration via a catheter or balloon dilation is performed, residual thrombus with heavy or low TIMI (thrombolysis in myocardial infarction) myocardial perfusion grading is still observed in some patients, suggesting disordered microcirculation. Currently, the treatment of microcirculatory disturbance in emergency PCI mainly employed injection of tirofiban, adenosine, thrombolytic agent or other drugs into the local area via a microcatheter in a short time, all of which can significantly reduce the thrombus load and improve TIMI perfusion. Herein, we report that a microcatheter was indwelled in the coronary artery for continuous pumping of low-dose thrombolytic drugs as reperfusion therapy in 12 patients with acute and subacute MI.

Effect of smoking status on clinical outcomes after reperfusion therapy for acute ischemic stroke.

Smoking has detrimental effects on the cardiovascular system; however, some studies have reported better clinical outcomes after thrombolysis for ischemic stroke in smokers than in nonsmokers, a phenomenon known as the smoking paradox. Therefore, this study aimed to examine the smoking paradox in patients with ischemic stroke receiving reperfusion therapy. Data were collected from a multicenter hospital-based acute stroke registry in Fukuoka, Japan. The 1148 study patients were categorized into current and noncurrent smokers. The association between smoking and clinical outcomes, including neurological improvement (≥ 4-point decrease in the National Institutes of Health Stroke Scale during hospitalization or 0 points at discharge) and good functional outcomes (modified Rankin Scale score of 0-2) at 3 months, was evaluated using logistic regression analysis and propensity score-matched analysis. Among the participants, 231 (20.1%) were current smokers. The odds ratios (ORs) of favorable outcomes after adjusting for potential confounders were not significantly increased in current smokers (OR 0.85, 95% confidence interval [CI] 0.60-1.22 for neurological improvement; OR 0.95, 95% CI 0.65-1.38 for good functional outcome). No significant association was found in the propensity score-matched cohorts. Smoking cessation is strongly recommended since current smoking was not associated with better outcomes after reperfusion therapy.

Effect of 2-Week Naringin Supplementation on Neurogenesis and BDNF Levels in Ischemia-Reperfusion Model of Rats.

BACKGROUND: Ischemic stroke is the leading cause of mortality and disability worldwide with more than half of survivors living with serious neurological sequelae; thus, it has recently attracted a lot of attention in the field of medical study. PURPOSE: The aim of this study was to determine the effect of naringin supplementation on neurogenesis and brain-derived neurotrophic factor (BDNF) levels in the brain in experimental brain ischemia-reperfusion. STUDY DESIGN: The research was carried out on 40 male Wistar-type rats (10-12 weeks old) obtained from the Experimental Animals Research and Application Center of Selçuk University. Experimental groups were as follows: (1) Control group, (2) Sham group, (3) Brain ischemia-reperfusion group, (4) Brain ischemia-reperfusion + vehicle group (administered for 14 days), and (5) Brain ischemia-reperfusion + Naringin group (100 mg/kg/day administered for 14 days). METHODS: In the ischemia-reperfusion groups, global ischemia was performed in the brain by ligation of the right and left carotid arteries for 30 min. Naringin was administered to experimental animals by intragastric route for 14 days following reperfusion. The training phase of the rotarod test was started 4 days before ischemia-reperfusion, and the test phase together with neurological scoring was performed the day before and 1, 7, and 14 days after the operation. At the end of the experiment, animals were sacrificed, and then hippocampus and frontal cortex tissues were taken from the brain. Double cortin marker (DCX), neuronal nuclear antigen marker (NeuN), and BDNF were evaluated in hippocampus and frontal cortex tissues by Real-Time qPCR analysis and immunohistochemistry methods. RESULTS: While ischemia-reperfusion increased the neurological score values, DCX, NeuN, and BDNF levels decreased significantly after ischemia in the hippocampus and frontal cortex tissues. However, naringin supplementation restored the deterioration to a certain extent. CONCLUSION: The results of the study show that 2 weeks of naringin supplementation may have protective effects on impaired neurogenesis and BDNF levels after brain ischemia and reperfusion in rats.

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial.

BACKGROUND: Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT. METHODS: This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 µg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days. DISCUSSION: This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden. TRIAL REGISTRATION: ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

Neuroprotective and Anti-Inflammatory Activities of Hybrid Small-Molecule SA-10 in Ischemia/Reperfusion-Induced Retinal Neuronal Injury Models.

Embolism, hyperglycemia, high intraocular pressure-induced increased reactive oxygen species (ROS) production, and microglial activation result in endothelial/retinal ganglion cell death. Here, we conducted in vitro and in vivo ischemia/reperfusion (I/R) efficacy studies of a hybrid antioxidant-nitric oxide donor small molecule, SA-10, to assess its therapeutic potential for ocular stroke. METHODS: To induce I/R injury and inflammation, we subjected R28 and primary microglial cells to oxygen glucose deprivation (OGD) for 6 h in vitro or treated these cells with a cocktail of TNF-α, IL-1ß and IFN-γ for 1 h, followed by the addition of SA-10 (10 µM). Inhibition of microglial activation, ROS scavenging, cytoprotective and anti-inflammatory activities were measured. In vivo I/R-injured mouse retinas were treated with either PBS or SA-10 (2%) intravitreally, and pattern electroretinogram (ERG), spectral-domain optical coherence tomography, flash ERG and retinal immunocytochemistry were performed. RESULTS: SA-10 significantly inhibited microglial activation and inflammation in vitro. Compared to the control, the compound SA-10 significantly attenuated cell death in both microglia (43% vs. 13%) and R28 cells (52% vs. 17%), decreased ROS (38% vs. 68%) production in retinal microglia cells, preserved neural retinal function and increased SOD1 in mouse eyes. CONCLUSION: SA-10 is protective to retinal neurons by decreasing oxidative stress and inflammatory cytokines.

The Relevance of Reperfusion Stroke Therapy for miR-9-3p and miR-9-5p Expression in Acute Stroke-A Preliminary Study.

Reperfusion stroke therapy is a modern treatment that involves thrombolysis and the mechanical removal of thrombus from the extracranial and/or cerebral arteries, thereby increasing penumbra reperfusion. After reperfusion therapy, 46% of patients are able to live independently 3 months after stroke onset. MicroRNAs (miRNAs) are essential regulators in the development of cerebral ischemia/reperfusion injury and the efficacy of the applied treatment. The first aim of this study was to examine the change in serum miRNA levels via next-generation sequencing (NGS) 10 days after the onset of acute stroke and reperfusion treatment. Next, the predictive values of the bioinformatics analysis of miRNA gene targets for the assessment of brain ischemic response to reperfusion treatment were explored. Human serum samples were collected from patients on days 1 and 10 after stroke onset and reperfusion treatment. The samples were subjected to NGS and then validated using qRT-PCR. Differentially expressed miRNAs (DEmiRNAs) were used for enrichment analysis. Hsa-miR-9-3p and hsa-miR-9-5p expression were downregulated on day 10 compared to reperfusion treatment on day 1 after stroke. The functional analysis of miRNA target genes revealed a strong association between the identified miRNA and stroke-related biological processes related to neuroregeneration signaling pathways. Hsa-miR-9-3p and hsa-miR-9-5p are potential candidates for the further exploration of reperfusion treatment efficacy in stroke patients.

Effect of IQ-1 on the Infarct Size and the Parameters of Cardiodynamic Indicators in the Acute Period after Myocardial Ischemia/Reperfusion in Rats.

The effect of a new JNK inhibitor IQ-1 (11H-indeno[1,2-b]quinoxalin-11-one oxime) was studied in male Wistar rats in a model of acute myocardial ischemia/reperfusion. Area at risk and myocardial infarct zones were studied in two series of experiments: 16 h after a single dose of IQ-1 (25 mg/kg intraperitoneally during cardiac ischemia) and on day 5 after its course administration (25 mg/kg intraperitoneally during cardiac ischemia and daily over 4 days). On day 5 after ischemia/reperfusion, cardiodynamic indicators were also studied: systolic, end-diastolic, and minimum pressure in the left ventricle, stress-time index, as well as the maximum rates of pressure rise and fall in the left ventricle (+dP/dtmax and -dP/dtmax). In 16 h after ischemia/reperfusion, the infarct area in the control was 24±2% of the total area of the sections, while after administration of IQ-1 this parameter was 14±1% (p<0.05). On day 5, the infarct area in the control group was 25±1% of the total area of myocardial sections. A course of IQ-1 administration led to a significant reduction in the infarct area to 10±2% of the total area of myocardial slices. Course administration of IQ-1 led to improvement in contractile function and weakening of the diastolic dysfunction of the left ventricle: systolic pressure in the left ventricle increased by 20%, +dP/dtmax by 23%, voltage-time index by 12%, -dP/dtmax by 43%, and the minimum pressure in the left ventricle decreased by 3.4 times.

Edaravone dexborneol protects against cerebral ischemia/reperfusion-induced blood-brain barrier damage by inhibiting ferroptosis via activation of nrf-2/HO-1/GPX4 signaling.

PURPOSE: Ferroptosis has recently been recognized as a mechanism of cerebral ischemia-reperfusion (I/R) injury, attributed to blood-brain barrier (BBB) disruption. Edaravone dexboneol (Eda.B) is a novel neuroprotective agent widely employed in ischemic stroke, which is composed of edaravone (Eda) and dexborneol. This study aimed to investigate the protective effects of Eda.B on the BBB in cerebral I/R and explore its potential mechanisms. METHODS: Transient middle cerebral artery occlusion (tMCAO) Sprague-Dawley-rats model was used. Rats were randomly assigned to sham-operated group (sham, n = 20), model group (tMCAO, n = 20), Eda.B group (Eda.B, n = 20), Eda group (Eda, n = 20) and dexborneol group (dexborneol, n = 20), and Eda.B + Zinc protoporphyria group (Eda.B + ZnPP, n = 5). Infarct area, cellular apoptosis and neurofunctional recovery were accessed through TTC staining, TUNEL staining, and modified Garcia scoring system, respectively. BBB integrity was evaluated via Evans blue staining. Nuclear factor E2 related factor 2 (Nrf-2)/heme oxygenase 1 (HO-1)/glutathione peroxidase 4 (GPX4) signaling were qualified by Western blot. Transmission electron microscopy (TEM) revealed alterations in ipsilateral brain tissue among groups. Glutathione (GSH) and malondialdehyde (MDA) levels, and Fe2+ tissue content determination were detected. RESULTS: Eda.B effectively improved neurological deficits, diminished infarct area and cellular apoptosis, as well as ameliorated BBB integrity in tMCAO rats. Further, Eda.B significantly inhibited ferroptosis, as evidenced by ameliorated pathological features of mitochondria, down-regulated of MDA and Fe2+ levels and up-regulated GSH content. Mechanistically, Eda.B attenuated BBB disruption via Nrf-2-mediated ferroptosis, promoting nuclear translocation of Nrf-2, increasing HO-1, GPX4 expression, alleviating the loss of zonula occludens 1 (ZO-1) and occludin as well as decreasing 4-hydroxynonenal (4-HNE) level. CONCLUSIONS: This study revealed for the first time that Eda.B safeguarded the BBB from cerebral I/R injury by inhibiting ferroptosis through the activation of the Nrf-2/HO-1/GPX4 axis, providing a novel insight into the neuroprotective effect of Eda.B in cerebral I/R.

Renoprotective effects of laxative linaclotide: Inhibition of acute kidney injury and fibrosis in a rat model of renal ischemia-reperfusion.

Ischemia-reperfusion (I/R) leads to tissue damage in transplanted kidneys, resulting in acute kidney injury (AKI) and chronic graft dysfunction, which critically compromises transplant outcomes, such as graft loss. Linaclotide, a guanylate cyclase C agonist clinically approved as a laxative, has recently been identified to exhibit renoprotective effects in a chronic kidney disease (CKD) model. This study evaluates the therapeutic effects of linaclotide on AKI triggered by I/R in a rat model with an initial comparison with other laxatives. Here, we show that linaclotide administration resulted in substantial reduction in serum creatinine levels, reflective of enhanced renal function. Histological examination revealed diminished tubular damage, and Sirius Red staining confirmed less collagen deposition, collectively indicating preserved structural integrity and mitigation of fibrosis. Further analysis demonstrated lowered expression of TGF-ß and associated fibrotic markers, α-SMA, MMP2, and TIMP1, implicating the downregulation of the fibrogenic TGF-ß pathway by linaclotide. Furthermore, one day after I/R insult, linaclotide profoundly diminished macrophage infiltration and suppressed critical pro-inflammatory cytokines such as TNF, IL-1ß, and IL-6, signifying its potential to disrupt initial inflammatory mechanisms integral to AKI pathology. These findings suggest that linaclotide, with its established safety profile, could extend its benefits beyond gastrointestinal issues and potentially serve as a therapeutic intervention for organ transplantation. Additionally, it could provide immediate and practical insights into selecting laxatives for managing patients with AKI or CKD, regardless of the cause, and for those receiving dialysis or transplant therapy.

Ischemia and reperfusion-injured liver-derived exosomes elicit acute lung injury through miR-122-5p regulated alveolar macrophage polarization.

Acute lung injury (ALI) is a common postoperative complication, particularly in pediatric patients after liver transplantation. Hepatic ischemia-reperfusion (HIR) increases the release of exosomes (IR-Exos) in peripheral circulation. However, the role of IR-Exos in the pathogenesis of ALI induced by HIR remains unclear. Here, we explored the role of exosomes derived from the HIR-injured liver in ALI development. Intravenous injection of IR-Exos caused lung inflammation in naive rats, whereas pretreatment with an inhibitor of exosomal secretion (GW4869) attenuated HIR-related lung injury. In vivo and in vitro results show that IR-Exos promoted proinflammatory responses and M1 macrophage polarization. Furthermore, miRNA profiling of serum identified miR-122-5p as the exosomal miRNA with the highest increase in young rats with HIR compared with controls. Additionally, IR-Exos transferred miR-122-5p to macrophages and promoted proinflammatory responses and M1 phenotype polarization by targeting suppressor of cytokine signaling protein 1(SOCS-1)/nuclear factor (NF)-κB. Importantly, the pathological role of exosomal miR-122-5p in initiating lung inflammation was reversed by inhibition of miR-122-5p. Clinically, high levels of miR-122-5p were found in serum and correlated to the severity of lung injury in pediatric living-donor liver transplant recipients with ALI. Taken together, our findings reveal that IR-Exos transfer liver-specific miR-122-5p to alveolar macrophages and elicit ALI by inducing M1 macrophage polarization via the SOCS-1/NF-κB signaling pathway.

Mechanism of astragaloside IV regulating NLRP3 through LOC102555978 to attenuate cerebral ischemia reperfusion induced microglia pyroptosis.

Astragaloside IV(ASⅣ), the main component of Radix Astragali, has been used to treat cerebral ischemia reperfusion injury (CIRI). However, the molecular mechanism of ASIV in CIRI needs to be further elucidated. Long non-coding RNA (lncRNA) is considered to be an important kind of regulatory molecule in CIRI. In this work, the biological effect and molecular mechanism of ASIV in CIRI through lncRNA were analyzed by using rat middle cerebral artery occlusion and reperfusion (MCAO/R) model and primary rat microglia (RM) cells oxygen and glucose deprivation/reoxygenation (OGD/R) model. The neurological deficit score was evaluated, the volume of cerebral infarction was calculated, and pyroptosis related molecules were detected by qPCR and western blot. Then, high-throughput sequencing was performed in sham and MCAO/R groups. The competitive endogenous RNA (ceRNA) networks associated with pyroptosis were constructed by functional enrichment analysis. CCK-8 detection of cell survival rate, qPCR and western blot were used to determine the specific molecular mechanism of ASⅣ through ceRNA in vitro. Results showed thatASⅣ could decrease the neurological deficit score, reduce the volume of cerebral infarction, inhibit inflammatory reaction and pyroptosis in MCAO/R model rats. Next, the ceRNA network was established, including the LOC102555978/miR-3584-5p/NLRP3 regulatory network. In vitro experiments showed that LOC102555978 promotes NLRP3 mediated pyroptosis of RM cells through sponge adsorption of miR-3584-5p, which may provide a potential therapeutic target for post-CIRI inflammation regulation. ASⅣ could inhibit pyroptosis of RM cells by down-regulating LOC102555978. LOC102555978/miR-3584-5p/NLRP3 may be the molecular mechanism of ASⅣ's CIRI protective effect.

Tanshinone IIA Alleviates Traumatic Brain Injury by Reducing Ischemia‒Reperfusion via the miR-124-5p/FoxO1 Axis.

Background: Cerebral ischemia-reperfusion injury is a common complication of ischemic stroke that affects the prognosis of patients with ischemic stroke. The lipid-soluble diterpene Tanshinone IIA, which was isolated from Salvia miltiorrhiza, has been indicated to reduce cerebral ischemic injury. In this study, we investigated the molecular mechanism of Tanshinone IIA in alleviating reperfusion-induced brain injury. Methods: Middle cerebral artery occlusion animal models were established, and neurological scores, tetrazolium chloride staining, brain volume quantification, wet and dry brain water content measurement, Nissl staining, enzyme-linked immunosorbent assay, flow cytometry, western blotting, and reverse transcription-quantitative polymerase chain reaction were performed. The viability of cells was measured by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide assays, while cell damage was measured by lactate dehydrogenase release in the in vitro oxygen glucose deprivation model. In addition, enzyme-linked immunosorbent assay, flow cytometry, western blotting, and reverse transcription-quantitative polymerase chain reaction were used to evaluate the therapeutic effect of Tanshinone IIA on ischemia/reperfusion (I/R) induced brain injury, as well as its effects on the inflammatory response and neuronal apoptosis, in vivo and in vitro. Furthermore, this study validated the targeting relationship between miR-124-5p and FoxO1 using a dual luciferase assay. Finally, we examined the role of Tanshinone IIA in brain injury from a molecular perspective by inhibiting miR-124-5p or increasing FoxO1 levels. Results: After treatment with Tanshinone IIA in middle cerebral artery occlusion-reperfusion (MCAO/R) rats, the volume of cerebral infarction was reduced, the water content of the brain was decreased, the nerve function of the rats was significantly improved, and the cell damage was significantly reduced. In addition, Tanshinone IIA effectively inhibited the I/R-induced inflammatory response and neuronal apoptosis, that is, it inhibited the expression of inflammatory cytokines IL-1ß, IL-6, TNF-α, decreased the expression of apoptotic protein Bax and Cleaved-caspase-3, and promoted the expression of antiapoptotic protein Bcl-2. In vitro oxygen-glucose deprivation/reoxygenation (OGD/R) cell model, Tanshinone IIA also inhibited the expression of inflammatory factors in neuronal cells and inhibited the occurrence of neuronal apoptosis. In addition, Tanshinone IIA promoted the expression of miR-124-5p. Transfection of miR-124-5p mimic has the same therapeutic effect as Tanshinone IIA and positive therapeutic effect on OGD cells, while transfection of miR-124-5p inhibitor has the opposite effect. The targeting of miR-124-5p negatively regulates FoxO1 expression. Inhibition of miR-124-5p or overexpression of FoxO1 can weaken the inhibitory effect of Tanshinone IIA on brain injury induced by I/R, while inhibition of miR-124-5p and overexpression of FoxO1 can further weaken the effect of Tanshinone IIA. Conclusion: Tanshinone IIA alleviates ischemic-reperfusion brain injury by inhibiting neuroinflammation through the miR-124-5p/FoxO1 axis. This finding provides a theoretical basis for mechanistic research on cerebral ischemia-reperfusion injury.