Effect of erigeron on intercellular adhesion molecule-1 and its mRNA expression during cerebral ischemia and reperfusion in rats

AIM: To investigate the effect of erigeron on intercellular adhesion molecule-1 (ICAM-1) and mRNA expression during cerebral ischemia/reperfusion. METHODS: The rat models of middle cerebral artery (MCA) focal cerebral ischemic reperfusion were established with the suture method in the study. The ICAM-1 mRNA and protein expression were measured by RT-PCR and immunohistochemistry techniques, respectively. RESULTS: By down-regulating the expression of ICAM-1 protein and mRNA and alleviating inflammation in cerebral ischemic region, erigeron exerted a protective effect in cerebral ischemia and reperfusion. CONCLUSION: The results suggest that erigeron protects the brain against cerebral ischemia and reperfusion injury via inhibiting ICAM-1 expressino.     

Pretreatment of hypertonic saline attenuates the hepatic ischemia reperfusion injury induced by neutrophils

AIM: To explore the effect of the pretreatment of hypertonic saline (HTS) in hepatic ischemia reperfusion (I/R) injury.METHODS: The rats were divided into sham group (sham group), ischemia reperfusion group (IR group) and pretreatment of hypertonic saline group (HTS group). Partial hepatic ischemia reperfusion model was used. The rats were sacrificed at the time of 1 h, 3 h, 6 h, 12 h and 24 h after reperfusion in each group, respectively. Blood samples were obtained to examine ALT. The expression of the CD11b/CD18 (Mac-1) on the neutrophils was analyzed by flow cytometry. RT-PCR and Western blotting were used to examine the expression of intercellular adhesion molecule-1 (ICAM-1) in livers and chromatometry was performed to detect the activity of myeloperoxidase (MPO) in livers. The morphology of hepatocytes and the structure of sinusoid were observed by histological examinations. RESULTS: ① HTS pretreatment decreased the level of ALT at the time points of 3 h, 6 h and 12 h after reperfusion (P<0.05). ② Mac-1 expression in HTS group was lower at 6 h and 12 h after reperfusion compared with IR group (P<0.05). ③ MPO activity in HTS group was lower at 6 h, 12 h and 24 h compared with IR group (P<0.05). ④ RT-PCR and Western blotting analysis indicated that the pretreatment of HTS inhibited the expression of ICAM-1 in livers after reperfusion. ⑤ Moderate hepatocyte swelling and few neutrophil infiltration were observed in HTS group.CONCLUSION: Pretreatment with HTS has the effect on hepatic ischemia reperfusion injury by inhibiting the expression of Mac-1 on circulating neutrophils and the expression of ICAM-1 in the liver.     

Protective effect of fluvastatin on ischemic reperfused myocardium in rabbits

AIM: To investigate the protective effect of fluvastatin and its influence on ICAM-1 mRNA expression in ischemia/reperfusion myocardium of normocholesterolemic rabbits. METHODS: 24 rabbits were divided into three groups randomly and myocardial ischemia/reperfusion model in the rabbit was made. Rabbits were subjected to 45 min of regional myocardial ischemia and 2 h of reperfusion. 10 mg·kg－1·d－1 fluvastatin were administered for one week. Dynamic index of blood flow was recorded and analyzed. Serum activity of CK, CKMB, LDH and LDH-1 were measured. The expression of ICAM-1 mRNA in ischemic myocardium was detected with semi-quantitative RT-PCR. RESULTS: In comparison with control group, pretreatment with fluvastatin decreased LVEDP at the whole observed duration, and spontaneously increased ±dp/dtmax. Serum activities of CK, CKMB and LDH-1 in control group were significantly higher than those in sham group, but heavily reduced in fluvastatin group. Increased expression of ICAM-1 mRNA due to ischemia reperfusion was reduced significantly in fluvastatin group compare to control group. CONCLUSION: Pretreatment of fluvastatin may reduce inflammation reaction in reperfused myocardium, and this may contribute to its protective effect against experimental myocardial ischemia reperfusion injury.     

Effect of propofol on expression of PKC mRNA in pulmonary injury induced by ischemia-reperfusion in rabbits

AIM: To investigate the effect of propofol on expression of protein kinase C (PKC) mRNA during pulmonary ischemia and reperfusion injury (PIRI) in rabbits. METHODS: Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups (n=9 in each): sham operated group (sham), PIR group (I-R) and PIR+ propofol group (PPF). Changes of several parameters including malondialdehyde (MDA), superoxide dismutase (SOD), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA) were measured at 60 minutes after reperfusion in lung tissue. Meanwhile the location and expression of PKC mRNA were observed. Lung tissue was also prepared for light microscopic and electron microscopic observation at 60 minutes after reperfusion. RESULTS: As compared with group I-R, PKC mRNA strongly expressed in intima and extima of small pulmonary artery as well as thin-wall vessels (mostly small pulmonary veins) in PPF group. The average optical density values of PKC-α、δ and θ mRNA in small pulmonary veins PPF in group showed significantly higher than that in I-R group (all P<0.01). SOD increased and MDA, W/D and IQA decreased at 60 minutes after reperfusion in lung tissue (P<0.01 and P<0.05). Abnormal changes of the lung tissue in morphology were lessen markedly in PPF group. CONCLUSIONS: Propofol produces notable protective effects on PIRI in rabbits by activating PKC-α， δ and θ mRNA expression in lung tissue, raising NO level, dropping OFR level and decreasing lipid peroxidation.     

Effects of heat shock protein 70 on inflammation after hepatic local ischemia/reperfusion in rats

AIM:To study the effects of heat shock protein 70 (HSP70) induced by the heat stress pretreatment on inflammation after hepatic ischemia/resperfusion.METHODS:With the hepatic local ischemia/reperfusion model (IR group),heat stress pretreatment (H+IR group) and injecting quercetin before heat stress pretreatment (Q+H+IR group) were performed.The HSP70,intercellular adhesion molecule-1 (ICAM-1) and the myeloperoxidase (MPO) activity were detected.The levels of serum ALT and AST and histological changes of the hepatocytes were also observed.RESULTS:In H+IR group,the HSP70 expression was higher than that in other groups at each time point,after performing ischemia-perfusion,hepatic injury was slighter.The levels of serum ALT and AST were increased slightly (P<0.01).The expression of ICAM-1 and the changes of MPO activity increased and peaked respectively at 6 h and 12 h after reperfusion.However,they were lower in H+IR group than those in IR group and Q+H+IR group.CONCLUSION:The HSP70 induced by heat stress pretreament reduces the expression of ICAM-1 and the changes of MPO activity during hepatic ischemia-reperfusion,then hepatic injury is depressed from the inflammation.     

Riboflavin preconditioning alleviates hepatic ischemia/reperfusion injury in rats

AIM: To explore the protective effect of riboflavin preconditioning on hepatic ischemia/reperfusion injury in rats. METHODS: Twenty-four Sprague-Dawley rats wererandomly divided into 3 groups (n=8): sham group, ischemia/reperfusion (I/R) group and riboflavin preconditioning (R+I/R) group. The rats in sham group and I/R group received a standard chow,while the rats in R+I/R group received a chow supplemented with riboflavin. After 4 weeks, portal vein and hepatic artery supplying the middle and left hepatic lobes were clamped with a traumatic vascular clip for induction of partial hepatic ischemia in the rats in I/R group and R+I/R group. After 1 h of ischemia, 1 h of reperfusion was conducted by removal of the clip. The activity of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in serum,the activity of superoxide dismutase (SOD) and the level of malondialdehyde (MDA) in serum and liver were measured. Western blotting was employed to examine the protein expression of heme oxygenase-1(HO-1) in the liver. RESULTS: The results showed that ischemia/reperfusion injury markedly increased the activity of AST and ALT in serum, decreased the activity of SOD, and elevated the level of MDA and the activity of HO-1 in the liver as compared with sham group (P<0.01). The riboflavin pretreatment significantly decreased the activity of AST and ALT in serum, increased the activity of SOD and decreased the levels of MDA in serum and liver as compared with I/R group (P<0.01). In addition, the protein expression of HO-1 and the activity of HO-1 were elevated in R+I/R group (P<0.01). Cytoplasmic vacuolation and swelling of the hepatocytes were observed in I/R group. Treatment with riboflavin markedly alleviated the changes of liver structure. CONCLUSION: Riboflavin preconditioning has protective effect on hepatic ischemia/reperfusion injury. The mechanism may be correlated with enhancing the anti-oxidation and alleviating the reaction of lipid peroxidation.     

Polydatin downregulates TLR4 expression in lung ischemia reperfusion injury in rabbits

AIM: To explore the influence of polydatin (PD) on Toll-like receptor 4 (TLR4) signal transduction pathway during lung ischemia reperfusion injury in rabbits. METHODS: Rabbit lung model of ischemia reperfusion (IR) injury was constituted in vivo. Thirty rabbits were divided into groups randomly: control (C), IR and PD group, respectively. The concentration of endotoxin (ET) in plasma was analyzed by end-point chromogenic assay. The protein expressions of TLR4, nuclear factor (NF)-κB p65 and heat shock protein 70 (HSP70) were measured by immunohistochemistry. The intracellular adhesion molecule-1 (ICAM-1) mRNA expression was detected by in situ hybridization histochemistry. The ultrastructural changes were observed by electron microscope. RESULTS: No significant difference of ET concentration in plasma between groups (all P>0.05) was observed. The protein expressions of TLR-4, NF-κB p65, HSP70 and ICAM-1mRNA in IR group were significantly increased as compared to C group and PD group, while those expressions in PD group were evidently higher than those in C group (all P<0.01). The lung pathological injuries in PD group were obviously alleviated as compared to IR group under electron microscope. CONCLUSION: It suggests that lung ischemia reperfusion releases endogenous ligands of TLR4 as HSP70, then activates NF-κB, promotes the release of mediators of inflammation such as ICAM-1. PD might have a protective effect on lung ischemia reperfusion injury by regulating TLR4 signal transduction pathway.     

Effect of ischemic preconditioning on expression of nitric oxide synthase in rat small-for-size liver graft

AIM:To investigate the effect of ischemic preconditioning (IPC) on expression of nitric oxide synthase (NOS) in rat small-for-size liver graft and its significance. METHODS:Sixty SD rats were randomly divided into 3 groups (n=10 pairs/group):nonwarm ischemia group (NWI);warm ischemic group (WI);and ischemic preconditioning group (IPC). The models of rat small-for-size liver transplantation were set up by two-cuff technique. Expression of eNOS mRNA and iNOS mRNA in hepatic tissue were detected by fluorescence-quantitating-PCR. RESULTS:Heptic expression of eNOS mRNA post-IPC was higher than that pre-IPC (P<0.05). Heptic expression of eNOS mRNA in each group at 0.5, 1, 2 and 3 h post-reperfusion was higher than that pre-operation (P<0.05). It was not different significantly between NWI and WI group (P>0.05). It was higher in IPC group than that in NWI and WI group (P<0.05 or P<0.01). Hepatic expression of iNOS mRNA was detected 1 h after reperfusion of liver graft. It was lower in IPC group than that in WI group (P<0.05 or P<0.01) and lower in NWI group than that in IPC group (P<0.05 or P<0.01) 2 h and 3 h post-reperfusion. CONCLUSION:IPC might protect liver graft by increasing the expression of eNOS mRNA at early stage after reperfusion and decreasing the expression of iNOS mRNA at later stage after reperfusion.     

The protection of the hepatic ischemic preconditioning is concerned with the NO/ET-1 system

AIM: To study the relationship between the disturbance of nitric oxide/endothelin-1(NO/ET-1) and hepatic ischemia/reperfusion(I/R) injury as well as the regulation of NO/ET-1 system by hepatic ischemic preconditioning(IPC). METHODS: The changes of NO/ET-1 system and their relationship with hepatic I/R injury were compared between I/R group and IPC+I/R group in a rat hepatic I/R model. Two hours after reperfusion, the liver tissues were detected by RT-PCR to see whether there was inducible nitric oxide synthase (iNOS) mRNA expression. RESULTS:In the acute phase of hepatic reperfusion, the ratio of NO/ET-1 was reduced, which was due to a significant reduction of NO₂^-/NO₃^- (the metabolic product of NO) and significant elevation of ET-1 in the blood plasma. The content of ALT, AST, LDH and TNF-α in blood plasma, and of MDA in liver tissue were increased but ATP in liver tissue was reduced, the hepatic damage was deteriorated. The protection of the hepatic IPC was concerned with the elevation of the ratio of NO/ET-1 caused by the elevation of NO₂^-/NO₃^-, and reduction of ET-1 as well. There was no iNOS mRNA detected in the liver tissues.CONCLUSION: Hepatic I/R injury is related to the disturbance of NO/ET-1. The protection of the hepatic IPC in the acute phase might be conducted by its regulation of NO/ET-1 system. The cNOS rather than the iNOS generated the NO in this situation.     

Effect of L-arginine on expression of bcl-2 and bax mRNA in pulmonary injury induced by ischemia-reperfusion in rabbits

AIM:To investigate the effect of L-arginine (L-Arg) on expression of bcl-2, bax mRNA during pulmonary ischemia and reperfusion injury (PIRI) in rabbits.METHODS:Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups: sham operated group (sham, n=12), ischemia-reperfusion group (I/R, n=12) and I/R+ L-arginine group (L-Arg, n=12). Changes of several parameters, which included apoptotic index (AI), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA), were measured at 300 min after reperfusion in lung tissue. Meanwhile the location and expression of bcl-2, bax mRNA as well as the ratio of bcl-2 mRNA/bax mRNA were observed. The lung tissue was prepared for light microscopic and electron microscopic observation at 60, 180 and 300 min after reperfusion. RESULTS:As compared with I/R group, in intima and extima of small pulmonary artery, alveoli, and bronchiole epithelia, the expression of bcl-2 mRNA and the ratio of bcl-2 mRNA/bax mRNA were increased, and the expression of bax mRNA was decreased in L-Arg treatment group. The values of AI, W/D and IQA showed significantly lower than that in I/R group at 180 minutes after reperfusion in lung tissue (P<0.01 and P<0.05). Meanwhile, abnormal changes of the lung tissue in morphologically were markedly lessened in L-Arg treatment group.CONCLUSION:L-arginine produces a notable protective effect on PIRI in rabbits by up-regulating bcl-2 mRNA expression, down-regulating bax mRNA expression in lung tissue and regulating the balance of bcl-2 mRNA and bax mRNA to decrease apoptosis.     

Effects of c-myb antisense RNA on the proliferation and collagen Ⅰ gene expression in cultured hepatic stellate cells

AIM:To investigate the effects of c-myb antisense RNA on the proriferation and collagen Ⅰ gene expression in cultured hepatic stellate cells(HSC) in rats.METHODS:The c-myb antisense gene recombinant retroviral vector(pDOR-myb) was constructed, and then was transfected into retroviral package cell line PA 317 by means of N-[1-(2,3-Dioleoyloxy) propyl]-N, N, N-trimethylammonium methyl-sulfate(DOTAP) liposomal transfection reagent. The pseudoviruses produced from the resistant PA317 cells selected with G418 were collected, with which HSCs isolated from rat liver were infected. The cell proliferation was measured by MTT method, c-myb, α₁-Ⅰ collagen mRNA expression and c-myb protein in HSCs were detected with semi-quantitative RT-PCR and western-blot, respectively.RESULTS:HSCs from rats were isolated successfully with the viability >98%. In the pDOR-myb infected HSCs, c-myb expression levels, the cell proliferation, and α₁-Ⅰ collagen mRNA expression were repressed significantly.CONCLUSIONS:c-myb plays a key role in the activation and proliferation of HSC. c-myb antisense RNA can inhibit cell proliferation and α₁-Ⅰ collagen mRNA expression in the infected HSC. These data suggest that inhibition of c-myb gene expression would be a potential way for the treatment of liver fibrosis.     

Effect of intestinal endotoxemia on ICAM-1 expression in the liver of rats

AIM: To investigate the effect of intestinal endotoxemia on intercellular adhesion molecule-1(ICAM-1) expression in the hepatic tissue.METHODS:Rat intestinal endotoxemia was induced by thioacetamide(TAA).Changes in ICAM-1 protein in the liver were detected by Western blot. RESULTS: The molecular weight of the ICAM-1 is 95 kD.Western blot analysis of hepatic tissue from control rats and rats injected with TAA within 6 hours revealed low ICMA-1 expression. ICAM-1 expression upregulation occured in rats with intestinal endotoxemia in experimental liver injury induced by TAA 12 h after TAA injection. ICAM-1 expression, plasma endotoxin level and alanine transaminase activity is of equal rank.CONCLUSION: Intestinal endotoxemia can upregulate ICAM-1 expression in the hepatic tissue and the latter is related to liver injury.     

Effect of fat-specific protein 27 on activation of rat hepatic stellate cells in vitro

AIM：To investigate the effects of fat-specific protein 27 (Fsp27) on the proliferation and activation of hepatic stellate cells (HSCs) in vitro. METHODS：HSCs were isolated from the liver of SD rats. The mRNA and protein expression of Fsp27 in primary HSCs and activated HSCs was detected by real-time fluorescence quantitative PCR, immunofluorescence staining and Western blotting. After 72 h of transfection with Fsp27-carrying lentivirus (pLV-Fsp27), the proliferation of HSCs was tested by CCK-8 assay, the protein expression of α-smooth muscle actin (α-SMA) in HSCs was detected by Western blotting, and the mRNA expression of fibrosis-related proteins, including matrix metalloproteinase 2 (MMP-2), tissue inhibitor of metalloproteinase 1 (TIMP-1) and transforming growth factor beta 1 (TGF-β1), was determined by real-time fluorescence quantitative PCR. RESULTS：Rat HSCs were successfully isolated and cultured. The difference of Fsp27 expression between primary HSCs and activated HSCs was significant (P<0.01). The proliferation and activation of HSCs was inhibited 72 h after pLV-Fsp27 transfection (P<0.05). Fsp27 enhanced the mRNA expression of MMP-2 and down-regulate the mRNA expression of TIMP-1 and TGF-β1 in activated HSCs (P<0.05). CONCLUSION：Fsp27 inhibits the proliferation and activation of HSCs and regulates the expression of fibrosis-related proteins. Fsp27 may play an important role in maintenance of the quiescent phenotype of HSCs.     

Exogenous carbon monoxide protects against the lung injury induced by ischemia-reperfusion of hind limbs in rats

AIM: To study the mechanism of protective effect of exogenous carbon monoxide (CO) in the lung injury induced by ischemia-reperfusion (IR) of hind limbs in rats. METHODS: Thirty-two SD rats were randomly divided into 4 groups: control, control+CO, IR and IR+CO. A rat model of ischemia in hind limbs and the reperfusion lung injury was made. The rats in IR+CO and control+CO groups were exposed to air containing 2.5×10-8 CO for 1 h before reperfusion or the corresponding control time point, while the other two groups were exposed to the routine air. The lung tissue structure, polymorphonuclear leukocyte (PMN) count, wet-to-dry weight ratio (W/D), malondialdehyde (MDA) content and the animal survival rate were observed. The carboxyhemoglobin (COHb) levels in artery blood were detected with CO-oximeter and the expression of intercellular adhesion molecule-1 (ICAM-1) in the lung was detected by Western blotting. RESULTS: Compared to control, the animal mortality, lung PMNs number, W/D, MDA content and ICAM-1 expression were all significantly increased in IR group. Compared with the IR group, the blood COHb level was significantly increased and the animal mortality, lung PMNs number, W/D, MDA content and ICAM-1 expression were all significantly decreased in IR+CO group. CONCLUSION: These data suggest that exogenous CO attenuate limb IR-induced lung injury by down-regulatiny ICAM-1 expression and suppressing PMN sequestration in the lung following limb IR in rats.     

Role of IRAK-4 activity in inhibitory effects of lipopolysaccharide pretreatment on hepatic ischemia/reperfusion injury

AIM:To observe the changes of interleukin-1 receptor associated kinase-4 (IRAK-4) in ischemia/reperfusion (I/R) liver pretreated with lipopolysaccharide (LPS) and to explore the protective mechanisms of LPS pretreatment against hepatic I/R injury. METHODS:Male Sprague-Dawley rats, weighing 240-280 g, were divided into three groups:control, ischemia/reperfusion group (I/R group) and LPS-pretreated group (LPS group). On the first day, LPS group received 0.1 mg/kg LPS via the tail vein, followed by 0.5 mg/kg on the 2nd, 3rd, 4th and 5th day. I/R group received the equivalent volumes (0.5 mL) of sterile PBS. Experiments of I/R injury was induced by temporary ischemia of the left lateral liver lobe for 90 min followed by 3 h reperfusion on 2 days after the last LPS treatment. At 0 min, 60 min and 180 min after reperfusion, the expression of IRAK-4 gene and protein level were determined by RT-PCR and Western blotting. The activity of NF-κB and the serum TNF-α level were also detected by ELISA. RESULTS:Although the level of IRAK-4 gene and protein were higher in the LPS group than that in I/R group and control group (P<0.01), no difference of the activities of NF-κB and the TNF-α level was observed between the LPS group and I/R group (P>0.05) at 0 min after reperfusion. However, all those indexes were evidently lower in the LPS group than those in I/R group (P<0.01) at 60 min and 180 min after reperfusion. CONCLUSION:This data suggests that the protective effects induced by LPS pretreatment against hepatic I/R injury may be via down-regulation of IRAK-4 expression.     

Effect of puerarin on expression of Fas/FasL mRNA in lung tissue with pulmonary injury induced by ischemia-reperfusion in rabbits

AIM：To investigate the effect of puerarin (Pur) on expression of Fas/FasL mRNA in lung tissue during pulmonary ischemia and reperfusion injury (PIRI) in rabbits.METHODS：Single lung ischemia and reperfusion animal model was used.The rabbits were randomly divided into three groups,sham operated group (sham,n=10),PIR group (I-R,n=30) and PIR+ Pur group (Pur,n=30).Changes of several parameters included apoptotic index (AI),wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA) were measured at 60,180 and 300 minutes after reperfusion in lung tissue.Meanwhile,the location and expression of Fas/FasL mRNA were observed.Lung tissue was prepared for light microscopic and electron microscopic observation at 60,180,300 minutes after reperfusion.RESULTS：As compared with group I-R,Fas/FasL mRNA slightly expressed in intima and extima of small pulmonary artery,alveoli,and bronchiole epithelia in group Pur.The values of AI,W/D and IQA showed significantly lower than that in group I-R at 60,180,300 minutes after reperfusion in lung tissue (P<0.01 and P<0.05).Meanwhile,abnormal changes of the lung tissue in morphologically were lessen markedly in group Pur.CONCLUSION：Puerarin produces a notable protective effects on PIRI in rabbits by inhibiting Fas/FasL mRNA expression and decreasing apoptosis.     

Effect of ischemia/reperfusion on expression of endothelin in the rat ventral prostate and preventive measure

AIM:Effect of ischemia/reperfusion on expression of endothelin-1(ET-1) in the rat prostate and preventive measure were studied. METHODS:The abdominal aorta of rat was clipped briefly and repeatedly so as to treat the prostate with ischemia/reperfusion and expression of ET-1 mRNA in the ventral prostate was determined by RT-PCR.RESULTS:Expression of ET-1 mRNA in the ventral prostate was significantly increased at 1 h and 3 h after 90 min repeated ischemia/reperfusion (P＜0.05), and was not significantly changed after previous treatment of Dizocilpine maleate (MK-801) (P＞0.05). CONCLUSIONS:Expression of ET-1 in the prostate can be affected by repeated brief ischemia/reperfusion and it may play a role in the development of benign prostatic hyperplasia. Ischemia-reperfusion-induced ET-1 expression in the prostate of rats can be inhibited by prectreatment of MK-801.     

Changes of aquaporin 4 expression after hepatic ischemia-reperfusion injury in rats

AIM: To study the relationship between the changes of aquaporin 4 (AQP4) expression and the liver functions in the process of hepatic ischemia-reperfusion (I/R) injury in rats. METHODS: Forty-eight Wistar rats were used to establish the animal model of hepatic I/R injury. The rats were subject to ischemia for 30 min and were randomly divided into 4 groups according to the time of reperfusion: 2 h group, 1 day group, 3 days group and 7 days group. The corresponding control animals were also set up. The serum was collected for detecting direct bilirubin (DB), indirect bilirubin (IB) and alanine transaminase (ALT). The pathological changes of the liver tissues were observed under microscope with HE staining. The protein expression of AQP4 was measured by the method of immunohistochemistry and the mRNA expression of AQP4 was detected by RT-PCR. RESULTS: Under microscope, degeneration and necrosis of the hepatic cells were observed in the liver tissues in I/R injury groups. Compared with sham operation group, the concentrations of DB, IB and ALT activity in I/R injury groups increased obviously, peaking on the first day after operation, then declining continuously and restoring to the normal levels on the 7th day after operation. The expression of AQP4 were significantly decreased in I/R injury animals in 2 h group, 1 day group and 3 days group, and reached the minimum level on the first day. The mRNA expression levels of AQP4 were also deceased in hepatic I/R injury rats in 2 h group, 1 day group and 3 days group, and reached the minimum level on the first day after operation, then increased slowly and restored to the normal levels on the 7th day after operation. CONCLUSION: Hepatic ischemia-reperfusion induces a decrease in AQP4 expression and impairs the liver functions, indicating an important role of AQP4 in the pathogenesis of liver ischemia-reperfusion injury.     

Knockdown of Atg5 aggravates cerebral ischemia and reperfusion injury in mice

AIM: To study the role of autophagy-related gene 5 (Atg5) in cerebral ischemia and reperfusion injury in mice. METHODS: BALB/c male mice (weighing 18~22 g) were randomly divided into sham group, ischemia/reperfusion (I/R) group, Atg5 siRNA group and control siRNA group. Focal cerebral ischemia was performed using the method of middle cerebral artery occlusion (MCAO) for 60 min and reperfusion for 24 h. In siRNA group and control group, 5 μL Atg5 siRNA or scrambled siRNA was administered by intracerebroventricular injection 24 h before MCAO. The expression of Atg5 at mRNA and protein levels in ischemic cortex at 24 h after reperfusion was determined by real-time PCR and Western blot. The infarct volume and edema were evaluated by TTC staining, and motor deficits were evaluated by neurological scoring. RESULTS: The expression of Atg5 at mRNA and protein levels was significantly increased 24 h after reperfusion in I/R group compared with sham group. Atg5 siRNA obviously decreased the expression of Atg5 at mRNA and protein levels induced by I/R. Inhibition of Atg5 exacerbated the infarct volume and ameliorated the neurological symptoms. CONCLUSION: Atg5 has neuroprotective effect on focal cerebral ischemia and reperfusion injury.