Effects of 2-APB on Store-operated Ca^(2+) Channel Currents of Hepatocytes after Hepatic Ischemia/Reperfusion Injury in Rats

The effects of hepatic ischemia/reperfusion (I/R) injuries on hepatocellular viability and store-operated calcium current (Isoc) in isolated rat hepatocytes and the effects of 2-APB on store-operated calcium current (Isoc) in isolated rat hepatocytes after hepatic ischemia/reperfusion injuries were studied. Hepatic ischemia and reperfusion injury model was established and whole cell patch-clamp techniques were used to investigate the effects of 2-APB on Isoc. The results showed that ischemia/reperfusion injuries could significantly reduce hepatocellular viability and further increase Isoc in hepatocytes and 2-APB (20, 40, 60, 80, 100 μmol/L) produced a concentration-dependent decrease of Isoc with IC 50 value of 64.63±10.56 μmol/L (n=8). It was concluded that ischemia/reperfusion injuries could reduce hepatocellular viability, probably through increased Isoc in hepatocytes and 2-APB had a protective effect on ischemia/reperfusion-induced liver injury, probably though inhibiting Isoc.

Peptidomic Analysis Reveals that Novel Peptide LDP2 Protects Against Hepatic Ischemia/Reperfusion Injury

Background and Aims:Hepatic ischemia/reperfusion(I/R)injury has become an inevitable issue during liver transplantation,with no effective treatments available.However,peptide drugs provide promising regimens for the treatment of this injury and peptidomics has gradually attracted increasing attention.This study was designed to analyze the spectrum of peptides in injured livers and explore the potential beneficial peptides involved in I/R injury.Methods:C57BL/6 mice were used to establish a liver I/R injury animal model.Changes in peptide profiles in I/R-injured livers were analyzed by mass spectrometry,and the functions of the identified peptides were predicted by bioinformatics.AML12 cells were used to simulate hepatic I/R injury in vitro.After treatment with candidate liver-derived peptides(LDPs)1–10,the cells were collected at various reperfusion times for further study.Results:Our preliminary study demonstrated that 6 h of reperfusion caused the most liver I/R injury.Peptidomic results suggested that 10 down-regulated peptides were most likely to alleviate I/R injury by supporting mitochondrial function.Most importantly,a novel peptide,LDP2,was identified that alleviated I/R injury of AML12 cells.It increased cell viability and reduced the expression of inflammation-and apoptosis-related proteins.In addition,LDP2 inhibited the expression of proteins related to autophagy.Conclusions:Investigation of changes in the profiles of peptides in I/R-injured livers led to identification of a novel peptide,LDP2 with potential function in liver protection by inhibiting inflammation,apoptosis,and autophagy.

The gut microbial metabolite, 3,4-dihydroxyphenylpropionic acid, alleviates hepatic ischemia/reperfusion injury via mitigation of macrophage pro-inflammatory activity in mice

Hepatic ischemia/reperfusion injury(HIRI) is a serious complication that occurs following shock and/or liver surgery. Gut microbiota and their metabolites are key upstream modulators of development of liver injury. Herein, we investigated the potential contribution of gut microbes to HIRI.Ischemia/reperfusion surgery was performed to establish a murine model of HIRI. 16 S r RNA gene sequencing and metabolomics were used for microbial analysis. Transcriptomics and proteomics analysis were employed to study the host cell responses. Our results establish HIRI was significantly increased when surgery occurred in the evening(ZT12, 20:00) when compared with the morning(ZT0, 08:00);however, antibiotic pretreatment reduced this diurnal variation. The abundance of a microbial metabolite3,4-dihydroxyphenylpropionic acid was significantly higher in ZT0 when compared with ZT12 in the gut and this compound significantly protected mice against HIRI. Furthermore, 3,4-dihydroxyphenylpropionic acid suppressed the macrophage pro-inflammatory response in vivo and in vitro. This metabolite inhibits histone deacetylase activity by reducing its phosphorylation. Histone deacetylase inhibition suppressed macrophage pro-inflammatory activation and diminished the diurnal variation of HIRI. Our findings revealed a novel protective microbial metabolite against HIRI in mice. The potential underlying mechanism was at least in part, via 3,4-dihydroxyphenylpropionic acid-dependent immune regulation and histone deacetylase(HDAC) inhibition in macrophages.

The Effect of Nitric Oxide/Endothelins System on the Hepatic Ischemia/Reperfus ion Injury

The relationship between the hepatic ischemia/reperfusion (I/R) injury and the b alance of nitric oxide/endothelins (NO/ET) was studied. The changes of the ratio of NO/ET and the hepatic injury were observed in a rat hepatic I/R model pretre ated with several tool drugs. In the acute phase of hepatic I/R injury, the rati o of plasma NO/ET was reduced from 1.58 ± 0.20 to 0.29 ± 0.05 ( P < 0.01) a nd the hepatic damage deteriorated. NO donor L Arg and ET receptor antagonist T AK 044 cou ld alleviate the hepatic I/R injury to some degree, whereas NO synthase inhibito r L NAME aggravated the damage. It was concluded that the hepatic I/R injury mi ght be related with the disturbance of the NO/ET balance. Regulation of this bal ance might have an effect on the I/R injury.

The effects of ischemia-reperfusion injury and hepatic artery ischemia on CD14 expression in canine auto-transplantation livers

Objective： To study the effect of ischemia-reperfusion injury（IRI） and hepatic artery ischemia（HAI） on CD14 expression in canine auto-transplantation livers. Methods：Liver orthotopic auto-transplantation models were applied with 30 healthy male Xi＇ an canines which were randomly divided into a control group, simultaneous reperfusion（SR） group and HAI group, CD14 protein expression, Malonaldehyde （MDA） Contents in hepatic tissues and ALT values in serum were detected, and the pathological changes of hepatic tissues was investigated under the light microscopy. Results：The level of CD14 protein expression in SR and HAI group tended to be time-dependent and both higher than controls with statistical significance（P 〈 0.01）; The peak values of these two groups both occurred at 4 h, but the level in HAI group （11.94 ± 0.43） was evidently higher than that in SR group（3.04 ± 0.34）. MDA contents in liver tissue, ALT values in serum and pathological changes showed the same changing tendency as CD 14 expression. Conclusion：（1） Up-regulation of CD14 expression may be the receptor-mechanism of Kupffer cells（KCs） activation in liver transplantation. （2） HAI can upregulate CD14 expression after portal vein reperfusion, improve the activity of KCs further more, increase OFRs production and cooperate with portal reperfusion, and finally aggravate the grafts injury.

Effects of Salvia miltiorrhiza on intestinal microflora in rats with ischemia/reperfusion liver injury

BACKGROUND: Hepatic ischemia/reperfusion injury may induce intestinal microflora imbalance. Salvia miltiorrhiza is effective in promoting blood circulation and counteracting peroxidation in tissues. The aim of the present study was to determine the effects of Salvia miltiorrhiza on intestinal mi- croflora, endotoxemia, and bacterial translocation in rats with hepatic I/R injury. METHODS: Sprague-Dawley rats in specific pathogen free grade were divided into 3 groups: group I(n =6) for sham operation: groups ( n = 7) for liver ische- mia for 20 minutes and reperfusion for 22 hours. Group was also pretreated with 4 ml/day of Salvia miltiorrhiza solu- tion (250 mg/kg) by daily gavage for 7 days. The levels of serum alanine aminotransferase (ALT), aspartate amino- transferase (AST), malondialdehyde ( MDA) and supero- xide dismutase ( SOD ) in liver tissues, serum endotoxin, intestinal bacterial counts, intestinal mucosal histology and bacterial translocation were studied. RESULTS: The levels of ALT, AST, plasma endotoxin and MDA in liver tissues were decreased more markedly in group (57.57 ± 18.08 U/L, 147.57 ±40.84 U/L, 0.42 ± 0.144 EU/ml and 0. 52 ±0.19 nmol/mg-prot respectively) in group 295.9±216.92 U/L, 0.80± 0.262 EU/ml and 0.72±0.12 nmol/mg-prot; P <0.05-0.01 respectively). Liver SOD activity was increased more sig- nificantly in group (318.47±64.62 U/mg-prot) than in group U/mg-prot, P<0.05). The counts of Bifidobacteria and Bacteroides increased more significantly in group than in group but were similar to those in group I. Bacterial translocation to the kidney in group was 50% (5/10), whereas no bacterial translocation to the kidney occurred in the other two groups (P <0. 01). Ileal mucosal structure was markedly ameliorated in group as compared with group CONCLUSIONS: Salviae miltiorrhiza could partially restore intestinal microflora balance, improve intestinal mucosal integrity, and reduce bacterial translocation and plasma en- dotoxin in rats with hepatic ischemia/reperfusion injury.

Experimental study on inhibitory effect of bridgy duct of hepatic artery on apoptosis of liver and bile duct cells

Objective： To investigate whether the method of bridgy duct established between the recipient＇s spleen artery and the donor＇s gastroduodenal artery could inhibit the apoptosis of liver and bile duct cells caused by hepatic artery ischemia. Methods： Twenty-four mongrel dogs from Xi＇an area were used to establish simplified models of dog orthotopic liver transplantation and divided into three groups randomly： HAI group （hepatic artery ischemia group）,BBB group（bypassing the blood by a bridgy duct） and control group. After cold perfusion, The samples were collected from liver and bile duct in each group at different time and fixed in glutaraldehyde and 4% polyformaldehyde respectively. At last, the apoptosis of liver and bile duct cells were observed and the apoptotic indexes were calculated. Results： Two hours after cold perfusion, apoptotic phenomenon was common in HAI group, rare in BBB group, while no apoptotic phenomenon was observed in control group. TUNEL staining showed that there was no significant difference in apoptotic index among the three groups immediately after cold perfusion. However, with time going, the apoptotic cells were increased in three groups, and the difference in apoptotic index was significant among three groups （P 〈 0.01 ）. Conclusions： Bridgy duct of hepatic artery can inhibit the apoptosis of liver and bile duct cells caused by HAI significantly.