During kidney transplant, the non-specific inflammatory response induced by ischemia-reperfusion injury (IRI) will lead to decreased survival ability of transplanted kidney. However, the effect of IRI on long-term survival rate of allograft is not sure. Here we illuminated the relationship between early IRI and decreased long-term survival ability of allograft by retrospectively analyzing the clinical evidences and laboratory investigations. Previous studies showed that early IRI resulted in the graft loss through reduction of renal functional mass, vascular injury, chronic hypoxia and subsequent fibrosis. IRI was also one of the main factors to induce dysfunction of transplanted kidney and acute rejection reaction, and to decrease the allograft survival. Therefore, it’s better to substitute traditional methods with novel measures during kidney transplant which may relieve the renal IRI much better.
Objective To investigate the effect of N-acetylserotonin (NAS) on the retinal microglia polarization in retinal ischemia-reperfusion injury (RIRI) rats and explore its mechanism via nucleotide-bound oligomeric domain 1 (NOD1)/receptor interacting protein 2 (Rip2) pathway. MethodsHealthy male Sprague Dawley rats were randomly divided into Sham (n=21), RIRI (n=21) and NAS (injected intraperitoneally 30 min before and after modeling with NAS, 10 mg/kg, n=18) groups, using random number table. And the right eye was used experimental eye. The RIRI model of rats in RIRI group and NAS group was established by anterior chamber high intraocular pressure method. Rats in NAS group were intraperitoneally injected with 10 mg/kg NAS before and 30 min after modeling, respectively. The retinal morphology and the number of retinal ganglion cell (RGC) in each group were detected by hematoxylin-eosin staining and immunohistochemical staining. The effect of NAS on polarization of retinal microglia was detected by immunofluorescence staining. Transcriptome sequencing technology was used to screen out the differentially expressed genes between Sham and RIRI groups. Western blot and real-time quantitative polymerase chain reaction (RT-PCR) were used to examine the differentially expressed genes. Immunohistochemical staining, Western blot and RT-PCR were used to investigate the effect of NAS on the expression of NOD1 and Rip2 protein and mRNA in retinal tissue and microglia of rats. General linear regression analysis was performed to determine the correlation between the number difference of NOD1+ cells and the number difference of M1 and M2 microglia in retinal tissues of rats in NAS group and RIRI group. ResultsA large number of RGC were observed in the retina of rats in Sham group. 24 h after modeling, compared with Sham group, the inner retinal thickness of rats in RIRI group was significantly increased and the number of RGC was significantly decreased. The thickness of inner retina in NAS group was significantly thinner and the number of RGC was significantly increased. Compared with Sham group, the number of retinal microglia of M1 and M2 in RIRI group was significantly increased. Compared with RIRI group, the number of M1 microglia decreased significantly and the number of M2 microglia increased significantly in NAS group. There was statistical significance in the number of M1 and M2 microglia in the retina of the three groups (P＜0.05). Transcriptome sequencing results showed that retinal NOD1 and Rip2 were important differential genes 24 h after modeling. The mRNA and protein relative expressions of NOD1 and Rip2 in retina of RIRI group were significantly higher than those of Sham group, with statistical significance (P＜0.05). The number of NOD1+ and Rip2+ cells and the relative expression of mRNA and protein in retinal microglia in RIRI group were significantly higher than those in Sham group, and NAS group was also significantly higher than that in Sham group, but lower than that in RIRI group, with statistical significance (P＜0.05). The number of Iba-1+/NOD1+ and Iba-1+/Rip2+ cells in retinal microglia in RIRI group was significantly increased compared with that in Sham group, and the number of Iba-1+/Rip2+ cells in NAS group was significantly decreased compared with that in RIRI group, but still significantly higher than that in Sham group, with statistical significance (P＜0.05). Correlation analysis results showed that the difference of retinal NOD1+ and Rip2+ cells in NAS group and RIRI group was positively correlated with that of M1 microglia (r=0.851, 0.895), and negatively correlated with that of M2 microglia (r=?0.797, ?0.819). The differences were statistically significant (P＜0.05). ConclusionNAS can regulate the microglial polarization from M1 to M2 phenotype, the mechanism is correlated with the NOD1/Rip2 pathway.
Objective To investigate the mechanism of bone morphogenetic protein-4 (BMP4) in promoting the recovery of small intestinal mucosal barrier function during the recovery period of small intestine ischemia-reperfusion (I/R) injury. Methods Twenty-eight C57BL/6J male mice aged 6–8 weeks were randomly selected and assigned to small intestine I/R group (n=24) and sham operation (SO) group (n=4) by random number table method. Small intestine I/R injury models of 24 mice were established, then 4 mice were randomly selected at 6, 12, 24 and 48 h after I/R established modeling and killed to observe the morphological changes of small intestinal mucosa and detect the expression of BMP4 mRNA in the jejunal epithelial cells, the other 8 mice were allocated for the experimental observation at the recovery period of small intestine I/R injury (24 h after I/R was selected as the observation time point of recovery period of small intestine I/R injury according to the pre-experimental results). Twelve mice were randomly divided into I/R-24 h-BMP4 group (recombinant human BMP4 protein was injected intraperitoneally), I/R-24 h-NS (normal saline) group (NS was injected intraperitoneally), and I/R-24 h-blank group (did nothing), 4 mice in each group. Then the small intestinal transmembrane electrical impedance (TER) was measured by Ussing chamber. The expressions of BMP4 protein and tight junction proteins (occludin and ZO-1), Notch signaling pathway proteins (Notch1 and Jagged1), and Smad6 protein were detected by Western blot. Results At 24 h after I/R injury, the injuries of villous epithelium, edema, and a small part of villi were alleviated. The BMP4 mRNA expressions at 6, 12, 24 and 48 h after I/R injury in the small intestinal epithelial cells were increased as compared with the SO group. Compared with the I/R-24 h-NS group and the I/R-24 h-blank group, the TER was increased, and the expression levels of occludin, ZO-1, p-Smad6, Notch1, Jagged1 were increased in the I/R-24 h-BMP4 group. Conclusion From the preliminary results of this study, during recovery period of small intestine I/R injury, the expression of BMP4 in small intestinal epithelial cells is increased, permeability of jejunal mucosal barrier is increased, which might promote the recovery of small intestinal mucosal barrier function by activating the Notch signaling pathway (Notch1 and Jagged1), Smad classic signaling pathway, and promoting the increase of tight junction protein expression (occludin and ZO-1).
ObjectiveTo investigate the effect of post-conditioning with fospropofol disodium on hepatic ischemiareperfusion (I/R) and its possible mechanism in rats.
MethodsForty-eight Sprague-Dawley rats were randomly divided into four groups, including sham group (S), control group (C), propofol group (P) and fospropofol disodium group (F). According to the different periods after reperfusion, each group was further divided into 2-hour and 4-hour reperfusion subgroups respectively (n=6 in each subgroup), named S2h, C2h, P2h, and F2h subgroups and S4h, C4h, P4h, and F4h subgroups. The livers of rats were reperfused after hepatic ischemia for one hour. In the beginning of reperfusion, normal saline was infused intravenously in group S and group C continuously, propofol was infused intravenously in group P continuously, fospropofol disodium was infused continuously in group F. The blood was sampled at the end of ischemia and reperfusion for assay of alanine aminotransferase (ALT) and aspartate aminotransferase (AST). The bcl-2 and bax protein contents in liver tissue were detected by immunohistochemical analysis, and liver samples were stained with hematoxylin-eosine for histological observation and damage degree evaluation by counting the proportion of necrosis cells.
ResultsThe activity of ALT and AST, the rate of necrosis cells and the amount of bcl-2 and bax protein after reperfusion in group C, group P and group F were higher than those in group S at matched reperfusion time points (P<0.05). The activity of ALT and AST, the proportion of necrosis cells and bax protein contents decreased in group P and group F, compared with group C at the same reperfusion time points, while the contents of bcl-2 protein were significantly increased (P<0.05).
ConclusionFospropofol disodium can alleviate hepatic injury induced by ischemia-reperfusion in rats, in which the bcl-2 and bax protein may play important roles.
ObjectiveTo investigate relationship between liver non-parenchymal cells and hepatic ischemia-reperfusion injury (HIRI).MethodThe relevant literatures on researches of the relationship between HIRI and liver non-parenchymal cells were analyzed and reviewed.ResultsDuring HIRI, hepatocytes could be severely damaged by aseptic inflammatory reaction and apoptosis. The liver non-parenchymal cells included Kupffer cells, sinusoidal endothelial cells, hepatic stellate cells, and dendritic cells, which could release a variety of cytokines and inflammatory mediators to promote the damage, and some liver non-parenchymal cells also had effect on reducing HIRI, for example: Kupffer cells could express heme oxygenase-1 to reduce HIRI, and hepatic stellate cells may participate in the repair process after HIRI. The role of liver non-parenchymal cells in HIRI was complex, but it also had potential therapeutic value.ConclusionLiver non-parenchymal cells can affect HIRI through a variety of mechanisms, which provide new goals and strategies for clinical reduction of HIRI.
Objective
To investigate the protective effect of the exosome on the organ damage induced by ische-mia-reperfusion (I/R) so as to provide a new way for the treatment of I/R damage.
Methods
The literature related to the treatment of I/R damage was reviewed and analyzed.
Results
The exosome volume is small and it is present in blood, cerebrospinal fluid, and urine, which has the function to cross the blood-brain barrier, and protect the heart, brain and other organs after I/R damage.
Conclusion
Exosome is a new material for the treatment of I/R organ injury, and it is important to understand the protective effect and possible mechanism.
ObjectiveTo investigate the protective effect of Shenfu injection on liver injury in rats with hind limb ischemia-reperfusion and its mechanism.
MethodsSixty-four male rats were randomly divided into sham operation group, ischemia-reperfusion group, Shenfu group〔Shenfu injection 7.5 mL/kg injection of peritoneal(ip), given 10 min before ischemia-reperfusion〕, Shenfu+Znpp group(Shenfu injection 7.5 mL/kg+Znpp 5 mg/kg ip, given 10 min before ischemia-reperfusion), 16 rats in each group. The rat model of hind limb ischemia-reperfusion injury was reproduced by occluding the hind limb artery of the rats for 3 h and subsequent reperfusing for 4 h. The liver tissues were gathered for malondialdehyde(MDA)and superoxide dismutase(SOD)determination. The expression of hemeoxygenase 1(HO-1)protein in the liver tissues was detected by immunohistochemistry. The pathological changes of liver were observed under the light microscope. The changes of serum glutamate-pyruvate transaminase(GPT)and glutamine oxaloacetic transaminase(GOT)were observed respectively.
Results①Compared with the sham operation group, the contents of MDA, GPT, GOT, and the expression of HO-1 protein were markedly increased in the ischemia-reperfusion group, Shenfu group, and Shenfu+Znpp group(P < 0.05), the activities of SOD were markedly decreased in the ischemia-reperfusion group and Shenfu+Znpp group(P < 0.05).②Compared with the ischemia-reperfusion group, the contents of MDA, serum GPT, GOT, and the expression of HO-1 protein were markedly decreased, the activity of SOD was markedly increased in the Shenfu group(P < 0.05).③Compared with the Shenfu group, the contents of MDA, GPT, GOT were markedly increased, the activity of SOD was markedly decreased in the Shenfu+Znpp group(P < 0.05). Unde ther light microscope, the pathological changes induced by ischemia-reperfusion were significantly attenuated by the Shenfu injection in the Shenfu group and were reversed by the Znpp in the Shenfu+Znpp group.
ConclusionShenfu injection inhibits liver tissue injury during hind limb ischemia-reperfusion, this protective effect might be partly through induction of HO-1.
ObjectiveTo analyze the protective mechanism of spinal cord ischemia-reperfusion injury mediated by N-methyl-D-aspartate (NMDA) receptor.MethodsA total of 42 SD rats were randomly assigned to 4 groups: a non-blocking group (n=6), a saline group (n=12), a NMDA receptor blocker K-1024 (25 mg/kg) group (n=12) and a voltage-gated Ca2+ channel blocker nimodipine (0.5 mg/kg) group (n=12). The medications were injected intraperitoneally 30 min before ischemia. The neural function was evaluated. The neuronal histologic change of spinal cord lumbar region, the release of neurotransmitter amino acids and expression of spinal cord neuronal nitric oxide synthase (nNOS) were compared.ResultsAt 8 h after reperfusion, the behavioral score of the K-1024 group was 2.00±0.00 points, which was statistically different from those of the saline group (5.83±0.41 points) and the nimodipine group (5.00±1.00 points, P<0.05). Compared with the saline group and nimodipine group, K-1024 group had more normal motor neurons (P<0.05). There was no significant difference in glutamic acid concentration in each group at 10 min after ischemia (P=0.731). The nNOS protein expression in the K-1024 group was significantly down-regulated compared with the saline group (P<0.01). After 8 h of reperfusion, the expression of nNOS protein in the K-1024 group was significantly up-regulated compared with the saline group (P<0.05).ConclusionK-1024 plays a protective role in spinal cord ischemia by inhibiting NMDA receptor and down-regulating nNOS protein expression; during the reperfusion, K-1024 has a satisfactory protective effect on spinal cord function, structure and biological activity of nerve cells.
Objective To identify the N6-methyladenosine (m6A)-related characteristic genes analyzed by gene clustering and immune cell infiltration in myocardial ischemia-reperfusion injury (MI/RI) after cardiopulmonary bypass through machine learning. Methods The differential genes associated with m6A methylation were screened by the dataset GSE132176 in GEO, the samples of the dataset were clustered based on the differential gene expression profile, and the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis of the differential genes of the m6A cluster after clustering were performed to determine the gene function of the m6A cluster. R software was used to determine the better models in machine learning of support vector machine (SVM) model and random forest (RF) model, which were used to screen m6A-related characteristic genes in MI/RI, and construct characteristic gene nomogram to predict the incidence of disease. R software was used to analyze the correlation between characteristic genes and immune cells, and the online website was used to build a characteristic gene regulatory network. Results In this dataset, a total of 5 m6A-related differential genes were screened, and the gene expression profiles were divided into two clusters for cluster analysis. The enrichment analysis of m6A clusters showed that these genes were mainly involved in regulating monocytes differentiation, response to lipopolysaccharides, response to bacteria-derived molecules, cellular response to decreased oxygen levels, DNA transcription factor binding, DNA-binding transcription activator activity, RNA polymerase Ⅱ specificity, NOD-like receptor signaling pathway, fluid shear stress and atherosclerosis, tumor necrosis factor signaling pathway, interleukin-17 signaling pathway. The RF model was determined by R software as the better model, which determined that METTL3, YTHDF1, RBM15B and METTL14 were characteristic genes of MI/RI, and mast cells, type 1 helper lymphocytes (Th1), type 17 helper lymphocytes (Th17), and macrophages were found to be associated with MI/RI after cardiopulmonary bypass in immune cell infiltration. Conclusion The four characteristic genes METTL3, YTHDF1, RBM15B and METTL14 are obtained by machine learning, while cluster analysis and immune cell infiltration analysis can better reveal the pathophysiological process of MI/RI.
ObjectiveTo observe the effects of overexpression of S100A4 protein on retinal capillary cells and retinal ganglion cells (RGC) after retinal ischemia-reperfusion injury (RIRI). MethodsOne hundred healthy adult male C57BL/6 mice were randomly divided into normal control group (group C), RIRI group, adeno-associated virus (AAV2)-S100A4 green fluorescent protein (GFP) intravitreal injection group (group S), RIRI+AAV2-GFP intravitreal injection group (group GIR), and RIRI+AAV2-S100A4-GFP intravitreal injection group (group SIR), with 20 mice in each group. The RIRI model was established using the high intraocular pressure anterior chamber method in the RIRI, GIR and SIR groups of mice. Eyes were enucleated 3 days after modelling by over anaesthesia. The number of retinal capillary endothelial cells and pericytes in the retinal capillaries of mice in each group was observed by retinal trypsinised sections and hematoxylin-eosin and periodic acid-Schiff staining; immunofluorescence staining was used to observe endothelial cell, pericyte coverage and RGC survival; The relative expression of Toll-like receptor 4 (TLR4), p38 MAPK and nuclear factor erythroid 2-related factor 2 (NRF2) in retinal tissues was measured by Western blot. One-way analysis of variance was used to compare data between groups. ResultsThree days after modeling, the endothelial cell to pericyte ratio in group C was compared with group S and SIR, and the difference was not statistically significant (F=106.30, P＞0.05); the SIR group was compared with group RIRI and GIR, and the difference was statistically significant (F=106.30, P＜0.000 1). Comparison of endothelial cell coverage in each group, the difference was not statistically significant (F=3.44, P＞0.05); compared with the pericyte coverage in group C, the RIRI group and the GIR group were significantly lower, and the difference was statistically significant (F=62.69, P＜0.001). Compared with the RGC survival rate in group C, it was significantly lower in RIRI and GIR groups, and the difference was statistically significant (F=171.60, P＜0.000 1); compared with RIRI and GIR groups, the RGC survival rate in SIR group was significantly higher, and the difference was statistically significant (F=171.60, P＜0.000 1). The relative expression levels of TLR4, p38 and NRF2 proteins were statistically significant among all groups (F=42.65, 20.78, 11.55; P＜0.05). ConclusionsPericytes are more sensitive to ischemia than endothelial cells after retinal RIRI in mice, and early vascular cell loss is dominated by pericytes rather than endothelial cells. The overexpression of S100A4 protein protects against loss of pericytes and RGC after RIRI by inhibiting the TLR4/p38/NRF2 signaling pathway.
