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 observe the influence of resveratrol on superoxide dismutase (SOD), malondialdehyde (MDA), intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) of intestinal mucosal ischemia-reperfusion injury protection in rats with severe acute pancreatitis (SAP). Methods Fifty-four rats were divided into three groups randomly: sham operation group (SO group), SAP model group (SAP group) and resveratrol-treated group (Res group). SAP model was made by injecting sodium taurocholate 50 mg/kg to pancreatic bile duct and resveratrol was given intravenously at 5 min after inducing SAP model. The rats were sacrificed at 3 h, 6 h and 12 h after inducing SAP model respectively by equal number. The levels of MDA, SOD, ICAM-1 and VCAM-1 and histological changes of small intestine were measured. Results The level of MDA in small intestine tissue in SAP group was significantly higher than that in SO group (P＜0.05), while the activity of SOD was significantly lower in the relevant tissues (P＜0.05). The expressions of ICAM-1 and VCAM-1 in SAP group were higher than those of SO group (P＜0.05). The activity of SOD in small intestine tissue in Res group was significantly higher than that in SAP group (P＜0.05); while the level of MDA was significantly lower in the relevant tissues (P＜0.05). The expressions of ICAM-1 and VCAM-1 in Res group were lower than those of SAP group (P＜0.05). Conclusions Oxygen free radicals are concerned with the process of pathological changes in intestinal mucosal ischemia-reperfusion in rats with SAP. Resveratrol might increase SOD activity and decrease MDA level to attenuate lipid peroxidation in small intestine of SAP, and reduce the expressions of ICAM-1 and VCAM-1 in intestine, thus diminish the damage of the intestine in SAP. And it acts as a protective effect to small intestinal ischemia-reperfusion injury.
Acute kidney injury (AKI) is characterized by a sudden and rapid decline of renal function and associated with high morbidity and mortality. AKI can be caused by various factors, and ischemia-reperfusion injury (IRI) is one of the most common causes of AKI. An increasing number of studies found out that exosomes of mesenchymal stem cells (MSCs) could alleviate IRI-AKI by the adjustment of the immune response, the suppression of oxidative stress, the reduction of cell apoptosis, and the promotion of tissue regeneration. This article summarizes the effect and mechanism of MSC-derived exosomes in the treatment of renal ischemia-reperfusion injury, in order to provide useful information for the researches on this field.
ObjectiveTo summarize the research advances of pyroptosis in hepatic ischamia-reperfusion injury (IRI).MethodThe literatures about the studies of mechanism of pyroptosis in hepatic IRI were retrieved and analyzed.ResultsPyroptosis, also known as inflammatory necrocytosis, was proven to play an important role in the hepatic IRI. When hepatic ischemia-reperfusion occurred, the classical pathway of pyroptosis dependenting on caspase-1 and the non-classical pathway of pyroptosis dependenting on caspase-11 were initiated by specific stimulants, and leaded to the activation of gasdermin D, releases of proinflammatory factors such as interleukin-1β, interleukin-18, etc., and the recruitment and activation of neutrophils. Consequently, pyroptosis caused more severe hepatic inflammation and aggravated existing cell injury and dysfunction of liver during hepatic IRI.ConclusionsPyroptosis plays an important role in liver IRI. Further researches about mechanism of pyroptosis will be beneficial to the prevention and treatment of the pyroptosis of related diseases.
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).
Objective To summarize the mechanism and research progress of Kruppel-like factor 2 (KLF2) in various liver diseases and related drug development, providing theoretical basis for further mechanism exploration and clinical application. Method The literatures on the mechanism of KLF2 in liver diseases at home and abroad were collected and summarized. Results KLF2 was widely distributed and had various functions in human body, mainly regulating the growth, differentiation and function of endothelial cells, inhibiting pro-inflammatory and pro-thrombotic gene expression, and participating in important physiological processes such as liver inflammation, oxidative stress and thrombosis, and affecting the occurrence and development of various liver diseases. The regulation of KLF2 expression by statins had been widely used in the treatment of liver diseases. Conclusion KLF2 regulates the expression of related molecules through a variety of pathways and affects the functions of various cells in the liver, which is the focus of research on improving liver injury.
ObjectiveTo compare the myocardial protective effect of HTK solution and St.ThomasⅡ(STH) solution in immature rabbit myocardium at different cardiac arrest time. MethodsAccording to cardioplegia and cardiac arrest time, 32 immature New Zealand white rabbits (aged 2-3 weeks) were randomly divided into four groups. A group SO (8 rabbits) underwent 1 hour cardiac arrest with STH solution, a group ST (8 rabbits) underwent 2 hours cardiac arrest with STH solution, a group HO (8 rabbits) underwent 1 hour cardiac arrest with HTK solution, a group Ht (8 rabbits) underwent 2 hours cardiac arrest with HTK solution. Compare the myocardial protective effect of HTK and STH solution in immature myocardium at different cardiac arrest time. ResultsThe Langendorff models were successfully established in 30 cases (8 cases in the group SO and HO, 7 cases in the group ST and HT). There were no statistical differences in hemodynamics and myocardial enzyme (CK-MB, LDH) (P > 0.05), but HTK solution reduced the activity of nitric oxide synthase (NOS) and content of malonaldehyde (MDA) and NO, maintained high activity of superoxide dismutase (SOD) and Ca2+-ATPase (P < 0.05), performed more effective myocardial protection for immature myocardium. ConclusionHTK solution has more effective myocardial protection for immature myocardium than STH solution does, but STH solution still has good outcomes within short cardiac arrest time (1h).
ObjectiveTo understand the current research progress on the role of hydrogen sulfide (H2S) in liver diseases. MethodThe relevant literature on the role of H2S in the liver diseases published in recent years was retrieved and reviewed. ResultsCurrent research focused primarily on exploring the mechanisms of H2S in various liver diseases. Studies had shown that H?S played an important role in the occurrence and development of liver diseases through mechanisms such as antioxidative stress, anti-inflammatory effects, regulation of autophagy, endoplasmic reticulum stress, angiogenesis, and cell death. ConclusionsBy supplementing exogenous H2S, adjusting the gut microbiota, or inhibiting key enzymes involved in H?S synthesis, the concentration of H2S in the body can be modulated, providing new strategies for treating liver diseases. However, the related mechanisms are still controversial. Future research should further investigate the specific role of H2S in different liver diseases and how to precisely control its level in the body to achieve targeted drug delivery.
Objective To investigate the mechanism of AMP-activated protein kinase (AMPK) in hepatic ischemia-reperfusion injury (HIRI). Methods ① Grouping. Forty-two mice were randomly divided into Sham group, 4 ischemia reperfusion (IR) group of different times (2, 6, 12, and 24 h), Compound C group, and Compound C+repamycin (Rapa) group, each group enrolled in 6 mice. Compound C group: mice were modeled at 1 h after intraperitoneal injection of Compound C (25 mg/kg). Compound C+Rapa group: mice were modeled at 1 h after intraperitoneal injection of rapamycin (1 mg/kg) and Compound C (25 mg/kg). Mice of 4 IR groups, Compound C group, and Compound C+Rapa group were used to prepare HIRI model. Mice of Sham group were treated only for laparotomy, freeing the first portal hepatis and closing peritoneal. ② To filter the best IR time. The levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum of mice in Sham group and IR groups of 4 different reperfusion time points were measured. The pathological changes of liver tissues were observed by HE staining, and the expressions of related proteins in liver tissue of mice were detected by Western blot. Considering the results of blood biochemical test, HE staining, and Western blot together to determine the best IR point. ③ The exploration of signal pathway for AMPK. The expressions of proliferating cell nuclear antigen (PCNA) were observed by immunohistochemical staining in the liver tissues of IR-12 h group, Compound C group (12 h after IR) and compound C+Rapa group (12 h after IR). The mitochondrial damage was observed by rhodamine 123 staining, and the apoptotic status of liver cells was detected by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay (TUNEL). Results ① The 12 h after IR was the best observation time point. Compared with IR-12 h group, the levels of ALT and AST in Sham group, IR-2, 6, and 24 h groups were lower (P<0.05). HE staining showed that liver tissue destruction in IR-12 h group was the most severe. Western blot showed that, expressions of AMPKα, phosphorylated adenylate activated protein kinase α (p-AMPKα), Nip3-like protein X (Nix), BCL-2 homologous water-soluble protein (Bax), as well as ratio of autophagy microtubule-associated protein light chain 3 (LC3)Ⅱto LC3Ⅰof Sham group, IR-2, 6, and 24 h group were all lower than those of IR-12 h group (P<0.05), but the expressions of phosphorylated mammalian target of Rapa (p-mTOR) of Sham group, IR-2, 6, and 24 h group were all higher (P<0.05). Therefore, 12 h after IR was the best time to observe. ② Compared with IR-12 h group, the expression level of PCNA protein in liver tissue of Compound C group was lower (P<0.05), the mitochondrial luminescence intensity was weaker and the apoptotic cells were more. Compared with Compound C group, the expression of PCNA protein in the liver tissue of the Compound C+Rapa group was higher (P<0.05), the mitochondrial intensity was stronger and the apoptotic cells were less. ③ Compared with IR-12 h group, the expressions of Nix and p-AMPKα, and ratio of LC3Ⅱ to LC3Ⅰ in liver tissue of Compound C group decreased (P<0.05), while the expressions of p-mTOR, Caspase-3, and Cleaved Caspase-3 increased (P<0.05). Compared with Compound C group, the expressions of p-AMPKα and Nix in the liver tissue of Compound C+Rapa group increased (P<0.05), while the expressions of p-mTOR, Caspase-3, and Cleaved Caspase-3 decreased (P<0.05). Conclusion During the HIRI in mouse, AMPK regulates mitophagy and apoptosis through the mTOR/Nix pathway.
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.