Diacerein mitigates renal ischemia/reperfusion injury via inhibition of renal inflammation, dendritic cells maturation and apoptosis: the role of TLR4/NF-kB/NLRP3/IL-1beta signaling pathway / La diacereína mitiga la lesión por isquemia/reperfusión renal a través de la inhibición de la inflamación renal, la maduración de las células dendríticas y la apoptosis: el papel de la vía de señalización TLR4/NF-kB/NLRP3/IL-1beta

SUMMARY: One of the reasons for acute kidney damage is renal ischemia. Nevertheless, there are limited protective and therapeutic approaches for this problem. Diacerein is an anti-inflammatory drug characterized by numerous biological activities. We aimed to determine the ameliorative impact of diacerein on renal ischemia/reperfusion injury (I/R) condition, exploring the underlying mechanisms. Twenty-four male rats were allotted into four groups (n= 6): sham group; Diacerein (DIA) group; I/R group, in which a non-crushing clamp occluded the left renal pedicle for 45 min, and the right kidney was nephrectomized for 5 min before the reperfusion process; I/R + diacerein group, injected intraperitoneally with 50 mg diacerein/kg i.m 30 minutes prior to I/R operation. Ischemia/ reperfusion was found to affect renal function and induce histopathological alterations. The flow cytometry analysis demonstrated an elevated expression of innate and mature dendritic cells in I/R renal tissues. Moreover, upregulation in the expression of the inflammatory genes (TLR4, Myd88, and NLRP3), and overexpression of the pro-inflammatory cytokines (IL-1β), apoptotic (caspase-3) and pyroptotic (caspase-1) markers were observed in I/R-experienced animals. The aforementioned deteriorations were mitigated by pre-I/R diacerein treatment. Diacerein alleviated I/R-induced inflammation and apoptosis. Thus, it could be a promising protective agent against I/R.

La isquemia renal es una de los motivos del daño renal agudo. Sin embargo, los enfoques protectores y terapéuticos para este problema son limitados. La diacereína es un fármaco antiinflamatorio caracterizado por numerosas actividades biológicas. Nuestro objetivo fue determinar el impacto de mejora de la diacereína en la condición de lesión por isquemia/ reperfusión renal (I/R), explorando los mecanismos subyacentes. Veinticuatro ratas macho se distribuyeron en cuatro grupos (n= 6): grupo simulado; grupo de diacereína (DIA); grupo I/R, en el que una pinza no aplastante ocluyó el pedículo renal izquierdo durante 45 min, y el riñón derecho fue nefrectomizado durante 5 min antes del proceso de reperfusión; Grupo I/R + diacereína, inyectado por vía intraperitoneal con 50 mg de diacereína/kg i.m. 30 min antes de la operación I/R. Se encontró que la isquemia/ reperfusión afecta la función renal e induce alteraciones histopatológicas. El análisis de citometría de flujo demostró una expresión elevada de células dendríticas innatas y maduras en tejidos renales I/R. Además, se observó una regulación positiva en la expresión de los genes inflamatorios (TLR4, Myd88 y NLRP3) y una sobreexpresión de las citoquinas proinflamatorias (IL-1β), marcadores apoptóticos (caspasa-3) y piroptóticos (caspasa-1) en animales con experiencia en I/R. Los deterioros antes mencionados fueron mitigados por el tratamiento previo a la diacereína I/R. La diacereína alivió la inflamación y la apoptosis inducidas por I/R. Por lo tanto, podría ser un agente protector prometedor contra I/R.

The antioxidant effect of preischemic dexmedetomidine in a rat model: increased expression of Nrf2/HO-1 via the PKC pathway

Abstract Background The precise underlying mechanism of antioxidant effects of dexmedetomidine-induced neuroprotection against cerebral ischemia has not yet been fully elucidated. Activation of Nuclear factor erythroid 2-related factor (Nrf2) and Heme Oxygenase-1 (HO-1) represents a major antioxidant-defense mechanism. Therefore, we determined whether dexmedetomidine increases Nrf2/HO-1 expression after global transient cerebral ischemia and assessed the involvement of Protein Kinase C (PKC) in the dexmedetomidine-related antioxidant mechanism. Methods Thirty-eight rats were randomly assigned to five groups: sham (n = 6), ischemic (n = 8), chelerythrine (a PKC inhibitor; 5 mg.kg-1 IV administered 30 min before cerebral ischemia) (n = 8), dexmedetomidine (100 µg.kg-1 IP administered 30 min before cerebral ischemia (n = 8), and dexmedetomidine + chelerythrine (n = 8). Global transient cerebral ischemia (10 min) was applied in all groups, except the sham group; histopathologic changes and levels of nuclear Nrf2 and cytoplasmic HO-1 were examined 24 hours after ischemia insult. Results We found fewer necrotic and apoptotic cells in the dexmedetomidine group relative to the ischemic group (p< 0.01) and significantly higher Nrf2 and HO-1 levels in the dexmedetomidine group than in the ischemic group (p< 0.01). Additionally, chelerythrine co-administration with dexmedetomidine attenuated the dexmedetomidine-induced increases in Nrf2 and HO-1 levels (p< 0.05 and p< 0.01, respectively) and diminished its beneficial neuroprotective effects. Conclusion Preischemic dexmedetomidine administration elicited neuroprotection against global transient cerebral ischemia in rats by increasing Nrf2/HO-1 expression partly via PKC signaling, suggesting that this is the antioxidant mechanism underlying dexmedetomidine-mediated neuroprotection.

The Protective Effects of Geraniol Against Damage of Short Term Renal Ischemia-Reperfusion in Rats

Abstract Ischemia/reperfusion (I/R) injury is one of the main causes of acute kidney injury. The pathological mechanisms underlying renal I/R injury are complex and remain uncertain. The protective effects of antioxidant properties of geraniol against renal ischemia reperfusion (I/R) damage were investigated in our study. 28 Wistar albino male rats were randomly selected and 4 groups of n = 7 were created. A right kidney nephrectomy surgery was conducted to all groups under anesthesia. 2 ml SF was given to Groups I and II, 50 mg/kg and 100 mg/ kg geraniol were administered intraperitoneally an hour before ischemia to Groups III and IV, respectively. Except for Group I, 45 minutes of ischemia and 4 hours of reperfusion were applied to the groups. At the end of the experiment, parameters related to oxidative stress and inflammation were determined by comparing kidney function, antioxidant enzyme activities and histological changes. Following comparison of BUN and CRE values with CAT and SOD values in tissue samples of Group I and Group II, an increase in Group II was observed and as a result I/R damage formation occurred. Values of geraniol-treated Group III and Group IV approximated to that of Group I, and that the 50 mg/kg geraniol dose proved more effective than 100 mg/kg geraniol.

Experimental model of nephropathy associated with diabetes mellitus in mice

Purpose: Nontransmissible chronic diseases, such as diabetes mellitus (DM) and nephropathy, affect a significant portion of the population, often treated due to injuries that require healing and regeneration. To create an experimental model of associated comorbidities, for healing and regeneration studies, protocols for induction of nephropathy by ischemia and reperfusion (I/R) and induction of DM by injection of streptozotocin (STZ) were associated. Methods: Sixty-four mice (Mus musculus), female, adult, Swiss strain, weighing approximately 20 g, were divided into four groups: G1: control (n = 24), G2: nephropathy group (N) (n = 7), G3, DM (n = 9), and G4: N+DM (n = 24). Arteriovenous stenosis (I/R) of the left kidney was performed as the first protocol. The animals received a hyperlipidemic diet for 7 days after the injection of STZ (150 mg/kg, via i.p.) and an aqueous glucose solution (10%) for 24 h. The animals in the G3 and G4 groups were observed for 14 days before receiving the diet and STZ. The evolution of nephropathy was observed using a urine test strip and the DM, through the analysis of blood glucose with a reagent strip on a digital monitor. Results: The ischemic induction protocols of nephropathy and DM with STZ, associated, were sustainable, low-cost, and without deaths. There were alterations compatible with initial renal alterations, in the first 14 days, such as increased urinary density, pH alteration, presence of glucose, proteins and leukocytes, when compared to the control group. DM was confirmed by the presence of hyperglycemia 7 days after induction and its evolution after 14 days. The animals in the G4 group showed constant weight loss when compared to the other groups. It was possible to observe morphological alterations in the kidneys submitted to I/R, regarding coloration, during surgery and after the end of the observation period, in the volume and size of the left kidney, when compared to the contralateral kidney. Conclusion: It was possible to induce nephropathy and DM associated in the same animal, in a simple way, confirmed with rapid tests, without losses, providing a basis for future studies.

Naringenin attenuates cerebral ischemia/reperfusion injury by inhibiting oxidative stress and inflammatory response via the activation of SIRT1/FOXO1 signaling pathway in vitro

Purpose: To explore the protection of naringenin against oxygen-glucose deprivation/reperfusion (OGD/R)-induced HT22 cell injury, a cell model of cerebral ischemia/reperfusion (I/R) injury in vitro, focusing on SIRT1/FOXO1 signaling pathway. Methods: Cytotoxicity, apoptosis, reactive oxygen species (ROS) generation, malondialdehyde (MDA) content, 4-hydroxynonenoic acid (4-HNE) level, superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT) activities were measured by commercial kits. Inflammatory cytokines levels were determined by enzyme-linked immunosorbent assay (ELISA). The protein expressions were monitored by Western blot analysis. Results: Naringenin significantly ameliorated OGD/Rinduced cytotoxicity and apoptosis in HT22 cells. Meanwhile, naringenin promoted SIRT1 and FOXO1 protein expressions in OGD/R-subjected HT22 cells. In addition, naringenin attenuated OGD/R-induced cytotoxicity, apoptosis, oxidative stress (the increased ROS, MDA and 4-HNE levels, and the decreased SOD, GSH-Px and CAT activities) and inflammatory response (the increased tumor necrosis factor-α, interleukin [IL]-1ß, and IL-6 levels and the decreased IL-10 level), which were blocked by the inhibition of the SIRT1/FOXO1 signaling pathway induced by SIRT1-siRNA transfection. Conclusion: Naringenin protected HT22 cells against OGD/R injury depending on its antioxidant and anti-inflammatory activities via promoting the SIRT1/FOXO1 signaling pathway.

Cyanidin-3-O-glucoside plays a protective role against renal ischemia/ reperfusion injury via the JAK/STAT pathway

Purpose: To investigate the role of cyanidin-3-O-glucoside (C3G) in renal ischemia/reperfusion (I/R) injury and the potential mechanisms. Methods: Mouse models were established by clamping the left renal vessels, and in vitro cellular models were established by hypoxic reoxygenation. Results: Renal dysfunction and tissue structural damage were significantly higher in the I/R group. After treatment with different concentrations of C3G, the levels of renal dysfunction and tissue structural damage decreased at different levels. And its protective effect was most pronounced at 200 mg/kg. The use of C3G reduced apoptosis as well as the expression of endoplasmic reticulum stress (ERS)-related proteins. Hypoxia/reoxygenation (H/R)-induced apoptosis and ERS are dependent on oxidative stress in vitro. In addition, both AG490 and C3G inhibited the activation of JAK/STAT pathway and attenuated oxidative stress, ischemia-induced apoptosis and ERS. Conclusions: The results demonstrated that C3G blocked renal apoptosis and ERS protein expression by preventing reactive oxygen species (ROS) production after I/R via the JAK/STAT pathway, suggesting that C3G may be a potential therapeutic agent for renal I/R injury.

Effects of local and remote ischemic postconditioning methods on ischemiareperfusion injury in a young animal model of acute mesenteric ischemia

Purpose: Acute mesenteric ischemia (AMI) is a condition in pediatric surgery that ranges from intestine necrosis to death. Ischemic postconditioning (IPoC) methods were developed to reduce the damage caused by revascularization. This study aimed to evaluate the efficacy of these methods in an experimental weaning rat model. Methods: Thirty-two 21-day-old Wistar rats were allocated into four groups according to the surgical procedure performed: control, ischemia-reperfusion injury (IRI), local (LIPoC) and remote IPoC (RIPoC). At euthanasia, fragments of the intestine, liver, lungs, and kidneys were submitted to histological, histomorphometric, and molecular analyses. Results: In the duodenum, intestines, and kidneys histological alterations promoted by IRI were reversed by remote postconditioning method. In the distal ileum, the histomorphometric alterations could be reversed by the postconditioning methods with more evident effects promoted by the remote method. The molecular analysis found that the levels of expression of Bax (proapoptotic) and Bcl-XL (antiapoptotic) genes in the intestine were increased by IRI. These alterations were equally reversed by the postconditioning methods, with more evident effects of the remote method. Conclusions: IPoC methods positively reduced the damage caused by IRI in weaning rats.

Research progress of ferroptosis in hypoxia-associated brain injury / 生理学报

Cerebral hypoxia often brings irreversible damage to the central nervous system, which seriously endangers human health. It is of great significance to further explore the mechanism of hypoxia-associated brain injury. As a programmed cell death, ferroptosis mainly manifests as cell death caused by excessive accumulation of iron-dependent lipid peroxides. It is associated with abnormal glutathione metabolism, lipid peroxidation and iron metabolism, and is involved in the occurrence and development of various diseases. Studies have found that ferroptosis plays an important role in hypoxia-associated brain injury. This review summarizes the mechanism of ferroptosis, and describes its research progress in cerebral ischemia reperfusion injury, neonatal hypoxic-ischemic brain damage, obstructive sleep apnea-induced brain injury and high-altitude hypoxic brain injury.

Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury / 中华医学杂志(英文版)

BACKGROUND@#Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys.@*METHODS@#In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining.@*RESULTS@#15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI.@*CONCLUSION@#Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.

Protective effect of Guanxin Danshen formula on myocardial ischemiareperfusion injury in rats

Purpose: Myocardial ischemia/reperfusion injury (MIRI) leads to myocardial tissue necrosis, which will increase the size of myocardial infarction. The study examined the protective effect and mechanism of the Guanxin Danshen formula (GXDSF) on MIRI in rats. Methods: MIRI model was performed in rats; rat H9C2 cardiomyocytes were hypoxia-reoxygenated to establish a cell injury model. Results: The GXDSF significantly reduced myocardial ischemia area, reduced myocardial structural injury, decreased the levels of interleukin (IL-1ß, IL-6) in serum, decreased the activity of myocardial enzymes, increased the activity of superoxide dismutase (SOD), and reduced glutathione in rats with MIRI. The GXDSF can reduce the expression of nucleotide- binding oligomerization domain, leucine-rich repeat and pyrin domain containing nod-like receptor family protein 3 (NLRP3), IL-1ß, caspase-1, and gasdermin D (GSDMD) in myocardial tissue cells. Salvianolic acid B and notoginsenoside R1 protected H9C2 cardiomyocytes from hypoxia and reoxygenation injury and reduced the levels of tumor necrosis factor α (TNF-α) and IL-6 in the cell supernatant, decreasing the NLRP3, IL-18, IL-1ß, caspase-1, and GSDMD expression in H9C2 cardiomyocytes. GXDSF can reduce the myocardial infarction area and alleviate the damage to myocardial structure in rats with MIRI, which may be related to the regulation of the NLRP3. Conclusion: GXDSF reduces MIRI in rat myocardial infarction injury, improves structural damage in myocardial ischemia injury, and reduces myocardial tissue inflammation and oxidative stress by lowering inflammatory factors and controlling focal cell death signaling pathways.

Stigmasterol protects human brain microvessel endothelial cells against ischemia-reperfusion injury through suppressing EPHA2 phosphorylation / 中国天然药物

Stigmasterol is a plant sterol with anti-apoptotic, anti-oxidative and anti-inflammatory effect through multiple mechanisms. In this study, we further assessed whether it exerts protective effect on human brain microvessel endothelial cells (HBMECs) against ischemia-reperfusion injury and explored the underlying mechanisms. HBMECs were used to establish an in vitro oxygen and glucose deprivation/reperfusion (OGD/R) model, while a middle cerebral artery occlusion (MCAO) model of rats were constructed. The interaction between stigmasterol and EPHA2 was detected by surface plasmon resonance (SPR) and cellular thermal shift assay (CETSA). The results showed that 10 μmol·L-1 stigmasterol significantly protected cell viability, alleviated the loss of tight junction proteins and attenuated the blood-brain barrier (BBB) damage induced by OGD/R in thein vitro model. Subsequent molecular docking showed that stigmasterol might interact with EPHA2 at multiple sites, including T692, a critical gatekeep residue of this receptor. Exogenous ephrin-A1 (an EPHA2 ligand) exacerbated OGD/R-induced EPHA2 phosphorylation at S897, facilitated ZO-1/claudin-5 loss, and promoted BBB leakage in vitro, which were significantly attenuated after stigmasterol treatment. The rat MCAO model confirmed these protective effects in vivo. In summary, these findings suggest that stigmasterol protects HBMECs against ischemia-reperfusion injury by maintaining cell viability, reducing the loss of tight junction proteins, and attenuating the BBB damage. These protective effects are at least meditated by its interaction with EPHA2 and inhibitory effect on EPHA2 phosphorylation.

Soybean isoflavones alleviate cerebral ischemia/reperfusion injury in rats by inhibiting ferroptosis and inflammatory cascade reaction / 南方医科大学学报

OBJECTIVE@#To explore the mechanism that mediates the effect of soybean isoflavones (SI) against cerebral ischemia/reperfusion (I/R) injury in light of the regulation of regional cerebral blood flow (rCBF), ferroptosis, inflammatory response and blood-brain barrier (BBB) permeability.@*METHODS@#A total of 120 male SD rats were equally randomized into sham-operated group (Sham group), cerebral I/R injury group and SI pretreatment group (SI group). Focal cerebral I/R injury was induced in the latter two groups using a modified monofilament occlusion technique, and the intraoperative changes of real-time cerebral cortex blood flow were monitored using a laser Doppler flowmeter (LDF). The postoperative changes of cerebral pathological morphology and the ultrastructure of the neurons and the BBB were observed with optical and transmission electron microscopy. The neurological deficits of the rats was assessed, and the severities of cerebral infarction, brain edema and BBB disruption were quantified. The contents of Fe2+, GSH, MDA and MPO in the ischemic penumbra were determined with spectrophotometric tests. Serum levels of TNF-α and IL-1βwere analyzed using ELISA, and the expressions of GPX4, MMP-9 and occludin around the lesion were detected with Western blotting and immunohistochemistry.@*RESULTS@#The rCBF was sharply reduced in the rats in I/R group and SI group after successful insertion of the monofilament. Compared with those in Sham group, the rats in I/R group showed significantly increased neurological deficit scores, cerebral infarction volume, brain water content and Evans blue permeability (P < 0.01), decreased Fe2+ level, increased MDA level, decreased GSH content and GPX4 expression (P < 0.01), increased MPO content and serum levels of TNF-α and IL-1β (P < 0.01), increased MMP-9 expression and lowered occludin expression (P < 0.01). All these changes were significantly ameliorated in rats pretreated with IS prior to I/R injury (P < 0.05 or 0.01).@*CONCLUSION@#SI preconditioning reduces cerebral I/R injury in rats possibly by improving rCBF, inhibiting ferroptosis and inflammatory response and protecting the BBB.

Forsythiaside B inhibits cerebral ischemia/reperfusion-induced oxidative stress injury in mice via the AMPK/DAF-16/FOXO3 pathway / 南方医科大学学报

OBJECTIVE@#To study the protective effect of forsythiaside B (FB) against cerebral oxidative stress injury induced by cerebral ischemia/reperfusion (I/R) in mice and explore the underlying mechanism.@*METHODS@#Ninety C57BL/6 mice were randomized into sham-operated group, middle cerebral artery occlusion (MCAO) model group, and low-, medium and highdose (10, 20, and 40 mg/kg, respectively) FB groups. The expression levels of MDA, ROS, PCO, 8-OHdG, SOD, GSTα4, CAT and GPx in the brain tissue of the mice were detected using commercial kits, and those of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 were detected with Western blotting. Compound C (CC), an AMPK inhibitor, was used to verify the role of the AMPK pathway in mediating the therapeutic effect of FB. In another 36 C57BL/6 mice randomized into 4 sham-operated group, MCAO model group, FB (40 mg/kg) treatment group, FB+CC (10 mg/kg) treatment group, TTC staining was used to examine the volume of cerebral infarcts, and the levels of ROS and SOD in the brain were detected; the changes in the protein expressions of AMPK, P-AMPK, DAF-16, FOXO3 and P-FOXO3 in the brain tissue were detected using Western blotting.@*RESULTS@#In mice with cerebral IR injury, treatment with FB significantly reduced the levels of ROS, MDA, PCO and 8-OHdG, increased the activities of antioxidant enzymes SOD, GSTα4, CAT and GPx, and enhanced phosphorylation of AMPK and FOXO3 and DAF-16 protein expression in the brain tissue (P < 0.01). Compared with FB treatment alone, the combined treatment with FB and CC significantly reduced phosphorylation of AMPK and FOXO3, lowered expression of DAF-16 and SOD activity, and increased cerebral infarction volume and ROS level in the brain tissue of the mice (P < 0.01).@*CONCLUSION@#FB inhibits oxidative stress injury caused by cerebral I/R in mice possibly by enhancing AMPK phosphorylation, promoting the downstream DAF-16 protein expression and FOXO3 phosphorylation, increasing the expression of antioxidant enzymes, and reducing ROS level in the brain tissue.

An improved 4-vessel intermittent occlusion method for establishing rat models of global cerebral ischemia-reperfusion injury / 南方医科大学学报

OBJECTIVE@#To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley.@*METHODS@#Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group.@*RESULTS@#Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected.@*CONCLUSION@#The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.

Naoluo Xintong Decoction activates caspase-1/Gasdermin D pathway to promote angiogenesis of rat brain microvascular endothelial cells after oxygen glucose deprivation/reperfusion injury / 南方医科大学学报

OBJECTIVE@#To investigate the effects of Naoluo Xintong Decoction (NLXTD) on pyroptosis and angiogenesis of brain microvascular endothelial cells (BMECs) and explore the possible mechanisms in rats with oxygen-glucose deprivation/ reperfusion (OGD/R).@*METHODS@#Rat BMECs with or without caspase-1 siRNA transfection were cultured in the presence of 10% medicated serum from NLXTD-treated rats (or blank serum) and exposed to OGD/R. CCK-8 assay, Transwell chamber assay, and tube formation assay were used to assess proliferation, migration, and tube-forming abilities of the cells. The activity of lactate dehydrogenase (LDH) in the culture supernatant was determined using a commercial assay kit, and the levels of inflammatory factors IL-1β and IL-18 were detected with ELISA. The cellular expressions of pro-caspase-1, caspase-1, NLRP3, Gasdermin D, and angiogenesis-related proteins VEGF and VEGFR2 were detected using Western blotting.@*RESULTS@#The BMECs showed obvious injuries after OGD/R exposure. Compared with the blank serum, the medicated serum significantly improved the cell viability, migration ability, and lumen-forming ability (P < 0.01) and lowered the levels of IL-1β and IL-18 and the LDH release (P < 0.01) of the cells with OGD/R exposure. Western blotting showed that in the BMECs exposed to OGD/R, the medicated serum strongly upregulated the expression of VEGF and VEGFR2 proteins (P < 0.01) and reduced the protein expressions of pro-caspase-1, caspase-1, NLRP3, and Gasdermin D (P < 0.01), and transfection of the cells with caspase-1 siRNA further promoted the expressions of VEGFR2 protein in the cells (P < 0.01).@*CONCLUSION@#NLXTD can improve the proliferation, migration, and tube- forming ability and promote angiogenesis of BMECs with OGD/R injury probably by inhibiting the caspase-1/Gasdermin D pathway in pyroptosis, alleviating cell injury, and upregulating the expressions of VEGF and VEGFR2.

Maresin1 inhibits the NF-κB/caspase-3/GSDME signaling pathway to alleviate hepatic ischemia-reperfusion injury / 中华肝脏病杂志

Objective: To investigate the role of Maresin1 (MaR1) in hepatic ischemia-reperfusion injury (HIRI). Methods: The HIRI model was established and randomly divided into a sham operation group (Sham group), an ischemia-reperfusion group (IR group), and a MaR1 ischemia-reperfusion group (MaR1+IR group). MaR1 80ng was intravenously injected into each mouse's tail veins 0.5h before anesthesia. The left and middle hepatic lobe arteries and portal veins were opened and clamped. The blood supply was restored after 1h of ischemia. After 6h of reperfusion, the mice were sacrificed to collect blood and liver tissue samples. The Sham's group abdominal wall was only opened and closed. RAW267.4 macrophages were administered with MaR1 50ng/ml 0.5h before hypoxia, followed by hypoxia for 8h and reoxygenation for 2h, and were divided into the control group, the hypoxia-reoxygenation group (HR group), the MaR1 hypoxia-reoxygenation group (MaR1 + HR group), the Z-DEVD-FMK hypoxia-reoxygenation group (HR+Z group), the MaR1 + Z-DEVD-FMK hypoxia-reoxygenation group (MaR1 + HR + Z group), and the Con group without any treatment. Cells and the supernatant above them were collected. One-way analysis of variance was used for inter-group comparisons, and the LSD-t test was used for pairwise comparisons. Results: Compared with the Sham group, the levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), interleukin (IL)-1β, and IL-18 in the IR group were significantly higher (P < 0.05), with remarkable pathological changes, while the level in the MaR1 + IR group was lower than before (P < 0.05), and the pathological changes were alleviated. Compared with the Con group, the HR group had higher levels of IL-1β and IL-18 (P < 0.05), while the MaR1 + HR group had lower levels of IL-1β and IL-18 (P < 0.05). Western blot showed that the expressions of caspase-3, GSDME, and GSDME-N were significantly higher in the HR group and IR group than in the other groups; however, the expression was lower following MaR1 pretreatment. The Z-DEVD-FMK exploration mechanism was inhibited by the expression of caspase-3 in HIRI when using MaR1. Compared with the HR group, the IL-1β and IL-18 levels and the expressions of caspase-3, GSDME, and GSDME-N in the HR + Z group were decreased (P < 0.05), while the expression of nuclear factor κB was increased, but following MaR1 pretreatment, nuclear factor κB was decreased. There was no significant difference in the results between the MaR1 + H/R group and the MaR1 + H/R + Z group (P > 0.05). Conclusion: MaR1 alleviates HIRI by inhibiting NF-κB activation and caspase-3/GSDME-mediated inflammatory responses.

Pharmacological properties and mechanisms of Notoginsenoside R1 in ischemia-reperfusion injury / 中华创伤杂志(英文版)

Panax notoginseng is an ancient Chinese medicinal plant that has great clinical value in regulating cardiovascular disease in China. As a single component of panax notoginosides, notoginsenoside R1 (NGR1) belongs to the panaxatriol group. Many reports have demonstrated that NGR1 exerts multiple pharmacological effects in ischemic stroke, myocardial infarction, acute renal injury, and intestinal injury. Here, we outline the available reports on the pharmacological effects of NGR1 in ischemia-reperfusion (I/R) injury. We also discuss the chemistry, composition and molecular mechanism underlying the anti-I/R injury effects of NGR1. NGR1 had significant effects on reducing cerebral infarct size and neurological deficits in cerebral I/R injury, ameliorating the impaired mitochondrial morphology in myocardial I/R injury, decreasing kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin in renal I/R injury and attenuating jejunal mucosal epithelium injury in intestinal I/R injury. The various organ anti-I/R injury effects of NGR1 are mainly through the suppression of oxidative stress, apoptosis, inflammation, endoplasmic reticulum stress and promotion of angiogenesis and neurogenesis. These findings provide a reference basis for future research of NGR1 on I/R injury.

Chrysin alleviates cerebral ischemia-reperfusion injury by inhibiting ferroptosis in rats / 中国中药杂志

The purpose of this study is to investigate whether chrysin reduces cerebral ischemia-reperfusion injury(CIRI) by inhi-biting ferroptosis in rats. Male SD rats were randomly divided into a sham group, a model group, high-, medium-, and low-dose chrysin groups(200, 100, and 50 mg·kg~(-1)), and a positive drug group(Ginaton, 21.6 mg·kg~(-1)). The CIRI model was induced in rats by transient middle cerebral artery occlusion(tMCAO). The indexes were evaluated and the samples were taken 24 h after the operation. The neurological deficit score was used to detect neurological function. The 2,3,5-triphenyl tetrazolium chloride(TTC) staining was used to detect the cerebral infarction area. Hematoxylin-eosin(HE) staining and Nissl staining were used to observe the morphological structure of brain tissues. Prussian blue staining was used to observe the iron accumulation in the brain. Total iron, lipid pero-xide, and malondialdehyde in serum and brain tissues were detected by biochemical reagents. Real-time quantitative polymerase chain reaction(RT-qPCR), immunohistochemistry, and Western blot were used to detect mRNA and protein expression of solute carrier fa-mily 7 member 11(SLC7A11), transferrin receptor 1(TFR1), glutathione peroxidase 4(GPX4), acyl-CoA synthetase long chain family member 4(ACSL4), and prostaglandin-endoperoxide synthase 2(PTGS2) in brain tissues. Compared with the model group, the groups with drug intervention showed restored neurological function, decreased cerebral infarction rate, and alleviated pathological changes. The low-dose chrysin group was selected as the optimal dosing group. Compared with the model group, the chrysin groups showed reduced content of total iron, lipid peroxide, and malondialdehyde in brain tissues and serum, increased mRNA and protein expression levels of SLC7A11 and GPX4, and decreased mRNA and protein expression levels of TFR1, PTGS2, and ACSL4. Chrysin may regulate iron metabolism via regulating the related targets of ferroptosis and inhibit neuronal ferroptosis induced by CIRI.

Bombyx Batryticatus extract promotes microglia polarization to improve neuron injury and behaviors of cerebral ischemia/reperfusion rats / 中国中药杂志

This study aims to investigate the effect of Bombyx Batryticatus extract(BBE) on behaviors of rats with global cerebral ischemia reperfusion(I/R) and the underlying mechanism. The automatic coagulometer was used to detect the four indices of human plasma coagulation after BBE intervention for quality control of the extract. Sixty 4-week-old male SD rats were randomized into sham operation group(equivalent volume of normal saline, ip), model group(equivalent volume of normal saline, ip), positive drug group(900 IU·kg~(-1) heparin, ip), and low-, medium-, and high-dose BBE groups(0.45, 0.9, and 1.8 mg·g~(-1)·d~(-1) BBE, ip). Except the sham operation group, rats were subjected to bilateral common carotid artery occlusion followed by reperfusion(BCCAO/R) to induce I/R. The administration lasted 7 days for all the groups. The behaviors of rats were examined by beam balance test(BBT). Morphological changes of brain tissue were observed based on hematoxylin-eosin(HE) staining. Immunofluorescence method was used to detect common leukocyte antigen(CD45), leukocyte differentiation antigen(CD11b), and arginase-1(Arg-1) in cerebral cortex(CC). The protein expression of interleukin-1β(IL-1β), interleukin-4(IL-4), interleukin-6(IL-6), and interleukin-10(IL-10) was detected by enzyme-linked immunosorbent assay(ELISA). The non-targeted metabonomics was employed to detect the levels of metabolites in plasma and CC of rats after BBE intervention. The results of quality control showed that the BBE prolonged the activated partial thromboplastin time(APTT), prothrombin time(PT), and thrombin time(TT) of human plasma, which was similar to the anticoagulation effect of BBE obtained previously. The results of behavioral test showed that the BBT score of the model group increased compared with that of the sham operation group. Compared with the model group, BBE reduced the BBT score. As for the histomorphological examination, compared with the sham operation group, the model group showed morphological changes of a lot of nerve cells in CC. The nerve cells with abnormal morphology in CC decreased after the intervention of BBE compared with those in the model group. Compared with the sham operation group, the model group had high average fluorescence intensity of CD45 and CD11b in the CC. The average fluorescence intensity of CD11b decreased and the average fluorescence intensity of Arg-1 increased in CC in the low-dose BBE group compared with those in the model group. The average fluorescence intensity of CD45 and CD11b decreased and the average fluorescence intensity of Arg-1 increased in medium-and high-dose BBE groups compared with those in the model group. The expression of IL-1β and IL-6 was higher and the expression of IL-4 and IL-10 was lower in the model group than in the sham operation group. The expression of IL-1β and IL-6 was lower and the expression of IL-4 and IL-10 was higher in the low-dose, medium-dose, and high-dose BBE groups than in the model group. The results of non-targeted metabonomics showed that 809 metabolites of BBE were identified, and 57 new metabolites in rat plasma and 45 new metabolites in rat CC were found. BBE with anticoagulant effect can improve the behaviors of I/R rats, and the mechanism is that it promotes the polarization of microglia to M2 type, enhances its anti-inflammatory and phagocytic functions, and thus alleviates the damage of nerve cells in CC.

Protective effects of three kinds of borneol on different brain regions in acute cerebral ischemia/reperfusion model rats / 中国中药杂志

This study compared the ameliorating effects of L-borneol, natural borneol, and synthetic borneol on the injury of different brain regions in the rat model of acute phase of cerebral ischemia/reperfusion(I/R) for the first time, which provides a reference for guiding the rational application of borneol in the early treatment of ischemic stroke and has important academic and application values. Healthy specific pathogen-free(SPF)-grade SD male rats were randomly assigned into 13 groups: a sham-operation group, a model group, a Tween model group, a positive drug(nimodipine) group, and high-, medium-, and low-dose(0.2, 0.1, and 0.05 g·kg~(-1), respectively) groups of L-borneol, natural borneol, and synthetic borneol according to body weight. After 3 days of pre-administration, the rat model of I/R was established by suture-occluded method and confirmed by laser speckle imaging. The corresponding agents in different groups were then administered for 1 day. The body temperature was monitored regularly before pre-administration, days 1, 2, and 3 of pre-administration, 2 h after model awakening, and 1 d after model establishment. Neurological function was evaluated based on Zea-Longa score and modified neurological severity score(mNSS) 2 h and next day after awakening. The rats were anesthetized 30 min after the last administration, and blood was collected from the abdominal aorta. Enzyme-linked immunoassay assay(ELISA) was employed to determine the serum levels of tumor necrosis factor-alpha(TNF-α), interleukin-6(IL-6), IL-4, and transforming growth factor-beta1(TGF-β1). The brain tissues were stained with triphenyltetrazolium chloride(TTC) for the calculation of cerebral infarction rate, and hematoxylin-eosin(HE) staining was used for observing and semi-quantitatively evaluating the pathological damage in different brain regions. Immunohistochemistry was employed to detect the expression of ionized calcium binding adapter molecule 1(IBA1) in microglia. q-PCR was carried out to determine the mRNA levels of iNOS and arginase 1(Arg1), markers of polarization phenotype M1 and M2 in microglia. Compared with the sham-operation group, the model group and the Tween model group showed significantly elevated body temperature, Zea-Longa score, mNSS, and cerebral infarction rate, severely damaged cortex, hippocampus, and striatum, increased serum levels of IL-6 and TNF-α, and decreased serum levels of IL-4 and TGF-β1. The three borneol products had a tendency to reduce the body temperature of rats 1 day after modeling. Synthetic borneol at the doses of 0.2 and 0.05 g·kg~(-1), as well as L-borneol of 0.1 g·kg~(-1), significantly reduced Zea-Longa score and mNSS. The three borneol products at the dose of 0.2 g·kg~(-1) significantly reduced the cerebral infarction rate. L-borneol at the doses of 0.2 and 0.1 g·kg~(-1) and natural borneol at the dose of 0.1 g·kg~(-1) significantly reduced the pathological damage of the cortex. L-borneol and natural borneol at the dose of 0.1 g·kg~(-1) attenuated the pathological damage of hippocampus, and 0.2 g·kg~(-1) L-borneol attenuated the damage of striatum. The 0.2 g·kg~(-1) L-borneol and the three doses of natural borneol and synthetic borneol significantly reduced the serum level of TNF-α, and the 0.1 g·kg~(-1) synthetic borneol reduced the level of IL-6. L-borneol and synthetic borneol at the dose of 0.2 g·kg~(-1) significantly inhibited the activation of cortical microglia, and 0.2 g·kg~(-1) L-borneol up-regulated the expression of Arg1 and down-regulated the expression level of iNOS. In conclusion, the three borneol products may alleviate inflammation to ameliorate the pathological damage of brain regions of rats in the acute phase of I/R by inhibiting the activation of microglia and promoting the polarization of microglia from M1 type to M2 type. The protective effect on brain followed a trend of L-borneol > synthetic borneol > natural borneol. We suggest L-borneol the first choice for the treatment of I/R in the acute phase.