COVID-19 and hepatic injury: cellular and molecular mechanisms in diverse liver cells

The coronavirus disease 2019(COVID-19)represents a global health and economic challenge.Hepatic injuries have been approved to be associated with severe acute respiratory syndrome coronavirus(SARS-CoV-2)infection.The viral tropism pattern of SARS-CoV-2 can induce hepatic injuries either by itself or by worsening the conditions of patients with hepatic diseases.Besides,other factors have been reported to play a crucial role in the pathological forms of hepatic injuries induced by SARS-CoV-2,including cytokine storm,hypoxia,endothelial cells,and even some treatments for COVID-19.On the other hand,several groups of people could be at risk of hepatic COVID-19 complications,such as pregnant women and neonates.The present review outlines and discusses the interplay between SARS-CoV-2 infection and hepatic injury,hepatic illness comorbidity,and risk factors.Besides,it is focused on the vaccination process and the role of developed vac-cines in preventing hepatic injuries due to SARS-CoV-2 infection.

Study progress on mechanism of severe acute pancreatitis complicated with hepatic injury

Study on the action mechanism of inflammatory mediators generated by the severe acute pancreatitis （SAP） in multiple organ injury is a hotspot in the surgical field. In clinical practice, the main complicated organ dysfunctions are shock, respiratory failure, renal failure, encephalopathy, with the rate of hepatic diseases being closely next to them. The hepatic injury caused by SAP cannot only aggravate the state of pancreatitis, but also develop into hepatic failure and cause patient death, lts complicated pathogenic mechanism is an obstacle in clinical treatment. Among many pathogenic factors, the changes of vasoactive substances, participation of inflammatory mediators as well as OFR （oxygen free radical）, endotoxin, etc. may play important roles in its progression.

Study on protecting effects of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis

AIM: To investigate the protective effects and mechanisms of Baicalin and Octreotide on hepatic injury in rats with severe acute pancreatitis (SAP). METHODS: The SAP rat models were prepared and randomly assigned to the model control group, Baicalin treated group, and Octreotide treated group while other healthy rats were assigned to the sham-operated group. Rat mortality, levels of ALT, AST, liver and pancreas pathological changes in all groups were observed at 3, 6 and 12 h after operation. Tissue microarray (TMA) sections of hepatic tissue were prepared to observe expression levels of Bax, Bcl-2 protein and Caspase-3, and changes of apoptotic indexes.RESULTS: Rat survival at 12 h, expression levels of Bax, Caspase-3 protein and apoptotic indexes of liver were all significantly higher in treated groups than in model control group. While the liver and pancreas pathological scores, contents of ALT, AST, and expression levels of Bcl-2 protein were all lower in treated groups than in the model control group. CONCLUSION: Both Baicalin and Octreotide can protect rats with SAP by decreasing the contents of ALT, AST and expression levels of Bcl-2 protein, and improving the expression levels of Bax protein, Caspase-3 protein, and inducing apoptosis.

Two clinically relevant pressures of carbon dioxide pneumoperitoneum cause hepatic injury in a rabbit model

AIM:To observe the hepatic injury induced by carbon dioxide pneumoperitoneum(CDP) in rabbits,compare the eects olow-and high-pressure pneumoperitoneum,and to determine the degree o hepatic injury induced by these two clinically relevant CDP pressures.METHODS:Thirty healthy male New Zealand rabbits weighing 3.0 to 3.5 kg were randomly divided into three groups(n = 10 for each group) and subjected to the ollowing to CDP pressures:no gas control,10 mmHg,or 15 mmHg.Histological changes in liver tissues were observed with hematoxylin and eosin staining and transmission electron microscopy.Liver unction was evaluated using an automatic biochemical analyzer.Adenine nucleotide translocator(ANT) activity in liver tissue was detected with the atractyloside-inhibitor stop technique.Bax and Bcl-2 expression levels were detected bywestern blotting.RESULTS:Liver Functions in the 10 mmHg and 15 mmHg experimental groups were significantly disturbed compared with the control group.After CDP,the levels or alanine transaminase and aspartate transaminase were 77.3 ± 14.5 IU/L and 60.1 ± 11.4 IU/L,respectively,in the 10 mmHg experimental group and 165.1 ± 19.4 IU/L and 103.8 ± 12.3 IU/L,respectively,in the 15 mmHg experimental group,which were all higher than those of the control group(p < 0.05).There was no difference in pre-albumin concentration between the 10 mmHg experimental group and the control group,but the prealbumin level of the 15 mmHg experimental group was significantly lower than that of the control group(p < 0.05).No significant differences were observed in the levels of total bilirubin or albumin among the three groups.After 30 and 60 min of CDP,pH was reduced(p < 0.05) and fa CO2 was elevated(p < 0.05) in the 10 mmHg group compared with controls,and these changes were more pronounced in the 15 mmHg group.Hematoxylin and eosin staining showed no significant change in liver morphology,except for mild hyperemia in the two experimental groups.Transmission electron microscopy showed mild mitochondrial swelling in hepatocytes of the 10 mmHg group,and this was more pronounced in the 15 mmHg group.No significant difference in ANT levels was found between the control and 10 mmHg groups.However,ANT concentration was significantly lower in the 15 mmHg group compared with the control group.The expression of hepatic Bax was significantly increased in the two experimental groups compared with the controls,but there were no differences in Bcl-2 levels among the three groups.Twelve hours after CDP induction,the expression of hepatic Bax was more significant in the 15 mmHg group than in the 10 mmHg group.CONCLUSION:A CDP pressure of 15 mmHg caused more substantial hepatic injury,such as increased levels of acidosis,mitochondrial damage,and apoptosis;therefore,10 mmHg CDP is preferable for laparoscopic operations.

Hepatic injury induced by carbon dioxide pneumoperitoneum in experimental rats

AIM： To observe the hepatic injury induced by carbon dioxide pneumoperitoneum in rats and to explore its potential mechanism.METHODS： Thirty healthy male SD rats were randomly divided into control group （n = 10）, 0 h experimental group （n = 10） and 1 h experimental group （n = 10） after sham operation with carbon dioxide pneumoperitoneum. Histological changes in liver tissue were observed with hematoxylineosin staining. Liver function was assayed with an automatic biochemical analyzer. Concentration of malonyldialdehyde （MDA） and activity of superoxide dismutase （SOD） were assayed by colorimetry. Activity of adenine nucleotide translocator in liver tissue was detected with the atractyloside-inhibitor stop technique. Expression of hypoxia inducible factor-1 （HIF-1） mRNA in liver tissue was detected with in situ hybridization.RESULTS： Carbon dioxide 60 min could induce liver pneumoperitoneum for injury in rats. Alanine aminotransferase and aspartate aminotransferase were 95.7 ± 7.8 U/L and 86.8 ± 6.9 U/L in 0 h experimental group, and 101.4 ± 9.3 U/L and 106.6 ±8.7 U/L in 1 h experimental group. However, no significant difference was found in total billirubin, albumin, and pre-albumin in the three groups. In 0 h experimental group, the concentration of MDA was 9.83 ±2.53 μmol/g in liver homogenate and 7.64 ± 2.19 μmol/g in serum respectively, the activity of SOD was 67.58±9.75 nu/mg in liver and 64.47 ± 10.23 nu/mg in serum respectively. In 1 h experimental group, the concentration of MDA was 16.57±3.45 μmol/g in liver tissue and 12.49 ±4.21 μmol/g in serum respectively, the activity of SOD was 54.29 ±7.96 nu/mg in liver tissue and 56.31 ±9.85 nu/mg in serum respectively. The activity of ANT in liver tissue was 9.52 ± 1.56 in control group, 6.37± 1.33 in 0 h experimental group and 7.2 8±1.45 （10^-9 mol/min per gram protein） in 1 h experimental group, respectively. The expression of HIF-1 mRNA in liver tissue was not detected in control group, and its optical density difference value was 6.14±1.03 in 0 h experimental group and 9.51 ± 1.74 in 1 h experimental group, respectively. CONCLUSION： Carbon dioxide pneumoperitoneum during the sham operation can induce hepatic injury in rats. The probable mechanisms of liver injury include anoxia, ischemia reperfusion and oxidative stress. Liver injury should be avoided during clinical laparoscopic operation with carbon dioxide pneumoperitoneum.

Effect of naked eukaryotic expression plasmid encoding rat augmenter of liver regeneration on acute hepatic injury and hepatic failure in rats

AIM: To study the protective effect of eukaryotic expression plasmid encoding augmenter of liver regeneration (ALR) on acute hepatic injury and hepatic failure in rats. METHODS: The PCR-amplified ALR gene was recombined with pcDNA3 plasmid, and used to treat rats with acute hepatic injury. The rats with acute hepatic injury induced by intraperitoneal injection of 2 mL/kg 50% carbon tetrachloride (CCl4) were randomly divided into saline control group and recombinant pcDNA3-ALR plasmid treatment groups. Recombinant pcDNA3-ALR plasmid DNA (50 or 200 μg/kg) was injected into the rats with acute hepatic injury intravenously, intraperitoneally, or intravenously and intraperitoneally in combination 4 h after CCl4 administration, respectively. The recombinant plasmid was injected once per 12 h into all treatment groups four times, and the rats were decapitated 12 h after the last injection. Hepatic histopathological alterations were observed after HE staining, the expression of proliferating cell nuclear antigen (PCNA) in liver tissue was detected by immunohistochemical staining, and the level of serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) was determined by biochemical method. The recombinant plasmid DNA (200 μg/kg) and saline were intraperitoneally injected into the rats with acute hepatic failure induced by intraperitoneal injection of 4 mL/kg 50% CCl4 after 4 h of CCl4 administration, respectively. Rats living over 96 h were considered as survivals.RESULTS: The sequence of ALR cDNA of recombinant pcDNA3-ALR plasmid was accordant with the reported sequence of rat ALR cDNA. After the rats with acute hepatic injury were treated with recombinant pcDNA3-ALR plasmid, the degree of liver histopathological injury markedly decreased. The pathologic liver tissues, in which hepatic degeneration and necrosis of a small amount of hepatocytes and a large amount of infiltrating inflammatory cells were observed, and they became basically normal in the most effective group after four times of injection of recombinant pcDNA3-ALR plasmid. The indexes of PCNA significantly increased in the recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The level of serum AST and ALT remarkably reduced in recombinant pcDNA3-ALR plasmid treatment groups compared to model group. The results showed that the effect of 200 μg/kg recombinant pcDNA3-ALR plasmid in the rats with acute liver injury was stronger than that of 50μg/kg pcDNA3-ALR DNA.The effect of intravenous injection of recombinant pcDNA3ALR plasmid was better. After the rats with acute hepatic failure were treated with recombinant pcDNA3-ALR plasmid,the survival rate (40%) significantly increased in treatment groups compared to control group (15%, P＜0.01).CONCLUSION: The ALR gene may play an important role in relieving acute hepatic injury and hepatic failure by promoting hepatic cell proliferation and reducing level ofAST and ALT in CCl4-intoxicated rats.

Ex vivo-expanded bone marrow stem cells home to the liver and ameliorate functional recovery in a mouse model of acute hepatic injury

BACKGROUND:Stem cell transplantation provides a theoretical approach for liver regeneration medicine;it may promote liver regeneration and self-repair.However,the transplantation of bone marrow-mesenchymal stem cells expanded ex vivo as a therapy for liver disease has rarely been investigated.This study aimed to explore whether bone marrow stem cells expanded ex vivo home to the liver and foster hepatic recovery after CCl 4 injury.METHODS:Bone marrow cells from BALB/c mice were expanded ex vivo by multiple-passage cultivation,characterized by cytoflow immunofluorescence,and pre-labeled with PKH26 before intravenous infusion into animals treated with CCl 4.The integration of bone marrow cells into the liver was examined microscopically,and plasma hepatic enzymes were determined biochemically.RESULTS:Cultured bone marrow cells exhibited antigenic profiles comparable to those of primary medullary stem cells.Double immunofluorescence showed colocalization of these cells with proliferative activity and albumin expression in the liver of CCl 4 -treated mice.Densitometry showed increased in situ cell proliferation (50±14 vs 20±3 cells/high-power field,P<0.05) and albumin expression (149±25 vs 20±5 cells/high-power field,P<0.05) in the liver,as well as reduced serum aminotransferase levels (P<0.05) and better survival rates (P<0.05) in animals receiving cultured bone marrow cells relative to controls.CONCLUSIONS:Ex vivo-expanded bone marrow cells are capable of relocating to and proliferating in the chemically- injured liver.Transplantation of these pluripotent stem cells appears to improve serum indices of liver function and survival rate in mice after CCl4-induced hepatic damage.

Pathological and MR-DWI study of the acute hepatic injury model after stem cell transplantation

AIM： To investigate apparent diffusion coefficient （ADC） values as an indication of reconditioning of acute hepatic injury （AHI） after allogeneic mononuclear bone marrow cell （MBMC） transplantation. METHODS： Three groups were used in our study： a cell transplantation group （n = 21）, transplantation control group （n = 21） and normal control group （n = 10）. AHI model rabbits in the cell transplantation group were injected with 5 mL of MBMC suspension at multiple sites in the liver and the transplantation controls were injected with 5 mL D-Hanks solution. At the end of the 1st, 2nd and 4th wk, 7 rabbits were randomly selected from the cell transplantation group and trans- plantation control group for magnetic resonance diffu- sion-weighted imaging （MR-DWI） and measurement of the mean ADC values of injured livers. After MR-DWI examination, the rabbits were sacrificed and the livers subjected to pathological examination. Ten healthy rab- bits from the normal control group were used for MR- DWI examination and measurement of the mean ADC value of normal liver. RESULTS： At all time points, the liver pathological scores from the cell transplantation group were significantly lower than those in the transplantation control group （27.14± 1.46 vs 69.29± 6.16, 22.29 ± 2.29 vs 57.00± 1.53, 19.00 ± 2.31 vs 51.86 ± 6.04, P = 0.000）. The mean ADC values of the cell transplantation group were significantly higher than the transplantation con- trol group （（1.07± 0.07） ×10^-3 mm2/s vs （0.69 ± 0.05） ×10^-3 mm2/s, （1.41± 0.04） ×10^-3 mm2/s vs （0.84± 0.03） ×10^-3 mm2/s, （1.68 ± 0.04） ×10^-3 mm2/s vs （0.86± 0.04） ×10^-3 mm2/s, P = 0.000）. The pathological scores of the cell transplantation group and transplantation control group gradually decreased. However, their mean ADC values gradually increased to near that of the normal control. At the end of the 1st wk, the mean ADC values of the cell transplantation group and transplantation control group were significantly lower than those of the normal control group [（1.07 ± 0.07） ×10^-3 mm2/s vs （± 0.03） ×10^-3 mm2/s, （0.69± 0.05） ×10^-3 mm2/s vs （1.76 ± 0.03） ×10^-3 mm2/s, P = 0.000]. At any 2 time points, the pathological scores and the mean ADC values of the cell transplantation group were significantly different （P = 0.000）. At the end of the 1st wk, the pathological scores and the mean ADC values of the transplantation control group were significantly different from those at the end of the 2nd and 4th wk （P = 0.000）. However, there was no significant difference between the 2nd and 4th wk （P = 0.073 and 0.473, respectively）. The coefficient of correlation between the pathological score and the mean ADC value in the cell transplantation group was -0.883 （P = 0.000） and -0.762 （P = 0.000） in the transplantation control group. CONCLUSION： Tracking the longitudinally dynamic change in the mean ADC value of the AHI liver may reflect hepatic injury reconditioning after allogeneic MBMC transplantation.

Dimethylacetamide-induced Hepatic Injury in Vitro: Mechanism and Potential Preventive Strategy

N,N-Dimethylacetamide （DMAc） is a widely used organic solvent in modern chemical industry with low to moderate hepatotoxicity to occupational health of employees. But so far, there are fewer and less conclusive data concerning its pathogenic mechanism in detail. In current study, the toxicity of DMAc was firstly investigated on human normal hepatocytes （LO-2）, using a series of molecular biology measurements to ananlyze the effect and mechanism of DMAc-induced hepatic cell injury and explore effective prophylactic measures. We found that DMAc triggered LO-2 apoptosis in a obviously dose-dependent manner, caused by increased ROS generation and activation of Bcl-2 pathway. Significantly, glutathione （GSH） rather than vitamin C （Vit C） could partially inhibit DMAc-induced apoptosis thus showing potential as a effective precaution for workers.

Protective effects of 5,4'-dihydroxy-3',5'- dimethoxy-7-O-β-D -glucopyranosyloxy-flavone on experimental hepatic injury

AIM: To investigate the pharmacological effects of rice flavone (5,4'-dihydroxy-3',5'-dimethoxy-7-0-β-D-glucopyranosyloxy-flavone, RF) separated from panicle-differentiating to flowing rice on rat experimental hepatic injury. METHODS: Models of rat acute hepatic injury induced by carbon tetrachloride (CCl4) administration, rat hepatic fibrosis induced by thioacetamide, injury of primary cultured rat hepatocytes induced by CCl4, respectively, were established. After treated with RF, content of serum alanine transaminase (ALT), aspartate aminotransferase (AST) and albumin (Alb), hyaluronic acid (HA), the activity of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD), and hydroxyproline (Hyp) were measured and liver tissue was observed pathologically by hematoxylin-eosin (HE) staining. Effects of RF on pathological changes, function index, enzyme of scavenging free radicals and blood rheology were evaluated. RESULTS: In model of rat acute hepatic injury induced by CCI4, RF can significantly decrease the contents of serum ALT, AST, increase the content of Alb, improve the dropsy and fat denaturalization of hepatocytes. In model of rat hepatic fibrosis induced by thioacetamide, RF can inhibit the increase of HA, Hyp and whole blood viscosity, and improve the activities of GSH-Px and SOD, and inauricular microcirculation. CONCLUSION: RF has apparent protective effects on hepatic injury by increasing activity of GSH-Px and SOD, scavenging free radicals produced by CCI4, reducing blood viscosity, and improving microcirculation and blood supply.

Protective Effect of Extract Powder of Turmeric on Carbon Tetrachloride Induced Acute Hepatic Injury in Mice

To explore the protective effect of extract powder of turmeric on carbon tetrachloride （CCl4）-induced acute hepatic injury, the mice were administrated with extract powder of turmeric with different doses （50, 100, 200 mg/kg） for 7 d. Then the mice were treated with 0.12% CCl4 by intraperitoneal injection. The levels of ALT, AST in serum and activities of SOD, CAT, MDA, GSH-Px in liver tissue were detected and the liver lesions were examined. The results showed that the activities of ALT, AST and the level of MDA in extract powder of turmeric group were signif- icantly decreased, and the activities of SOD, CAT, GSH-Px were significantly increased, and liver pathology were improved compared with the injured group （P〈 0.05 or P〈0.01）. It indicated that the extract powder of turmeric had significant protective effect against CCl4 induced acute hepatic injury in mice.

Kupffer cells contribute to concanavalin A-induced hepatic injury through a Th1 but not Th17 type response-dependent pathway in mice

BACKGROUND:Increasing evidence suggests that a close interaction of Kupffer cells with T cells plays a central role in concanavalin A-induced hepatic injury in mice,but the underlying mechanisms remain obscure.The present study aimed to determine the relative roles of Th1 and Th17 type responses in concanavalin A-induced hepatic injury in mice, and to investigate whether or not Kupffer cells contribute to hepatic injury via a Th1 or Th17 type response-dependent pathway. METHODS:Immune-mediated hepatic injury was induced in C57BL/6 mice by intravenous injection of concanavalin A. Kupffer cells were inactivated by pretreatment with gadolinium chloride 24 hours before the concanavalin A injection.The interferon-gamma(IFN-γ)and interleukin-17(IL-17)pathways were blocked by specific neutralizing antibodies.Hepatic injury was assessed using serum transferase activity and pathological analysis.Expression of inflammatory cytokines within the liver was detected by real-time polymerase chain reaction and immunohistochemistry. RESULTS:Neutralization of IFN-γsignificantly attenuated concanavalin A-induced hepatic injury.However,neutralization of IL-17 failed to suppress the injury.Inactivation of Kupffer cells by gadolinium chloride pretreatment protected against concanavalin A-induced injury and significantly reduced hepatic cytokine levels including TNF-α,IL-6 and IFN-γbut not IL-17.CONCLUSION:Our findings suggest that Kupffer cells contribute to concanavalin A-induced hepatic injury via a Th1 type response-dependent pathway and production of inflammatory cytokines including TNF-α,IL-6 and IFN-γ.

Development of a novel rat model of heterogeneous hepatic injury by injection with colchicine via the splenic vein

AIM To develop a novel rat model of heterogeneous hepatic injury.METHODS Seventy male Sprague-Dawley rats were randomly divided into a control group(n = 10) and a colchicine group(n =60). A 0.25% colchicine solution(0.4 mL/kg) was injected via the splenic vein in the colchicine group to develop a rat model of heterogeneous hepatic injury. An equal volume of normal saline was injected via the splenic vein in the control group. At days 3, 7, and 14 and weeks 4, 8, and 12 after the operation, at least seven rats of the colchicine group were selected randomly for magnetic resonance imaging(MRI) examinations, and then they were euthanized. Ten rats of the control group underwent MRI examinations at the same time points, and then were euthanized at week 12. T2-weighted images(T2 WI) and diffusion weighted imaging(DWI) were used to evaluate the heterogeneous hepatic injury. The heterogeneous injury between the left and right hepatic lobes was assessed on liver sections according to the histological scoring criteria, and correlated with the results of MRI study. RESULTS Obvious pathological changes occurred in the hepatic parenchyma in the colchicine group. Hepatic injury scores were significantly different between the left and right lobes at each time point(P < 0.05). There was a significant difference in apparent diffusion coefficient(ADC) of DWI and liver-to-muscle ratio(LMR) of T2 WI between the left and right lobes of rats in the colchicine group(P < 0.05) at each time point, and similar results were observed between the colchicine and control groups. Besides, there was a significant correlation between hepatic injury scores and ADC values or LMR(r =-0.682, P = 0.000; r =-0.245, P = 0.018).CONCLUSION Injection with colchicine via the splenic vein can be used to successfully develop a rat model of heterogeneous hepatic injury. DWI and T2 WI may help evaluate the heterogeneous injury among liver lobes.

Research status of the mechanism and treatment for acute pancreatitis complicated with hepatic injury

Acute pancreatitis（AP） is characterized by its sudden onset and rapid progression and is often complicated by liver injury. APinduced liver injury may develop into hepatic failure and even result in death. Thus, it is of importance to protect liver function and block injury-related pathways. In the pathogenesis of liver injury in AP, inflammatory cytokines, nuclear factor-kappa B（NF- κB） and oxygen free radicals play important roles. The complexity of the mechanism underlying the development of liver injury exerts, to some extent, a contribution to the difficulties in the treatment of this disease. Currently, the drugs used to treat the disease include L-arginine （L-Arg）, calcium ion antagonists, somatostatin and a variety of inflammatory mediator inhibitors. Additionally, some traditional Chinese medicines such as tfipterygium, wilfordii, rhubarb and salvia milfiorrhizae may also have some effects. In this article, the pathogenesis of liver injury in AP and its therapy are reviewed.

The new antioxidant 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2- dihydroquinoline has a protective effect against carbon tetrachloride-induced hepatic injury in rats

Liver diseases with the central pathogenetic mechanism of oxidative stress are one of the main causes of mortality worldwide.Therefore,dihydroquinoline derivatives,which are precursors of hepatoprotectors and have antioxidant activity,are of interest.We have previously found that some compounds in this class have the ability to normalize redox homeostasis under experimental conditions.Here,we initially analyzed the hepatoprotective potential of the dihydroquinoline derivative 1-benzoyl-6-hydroxy-2,2,4-trimethyl-1,2-dihydroquinoline(BHDQ)for carbon tetrachloride(CCl4)-induced liver injury in rats.Results suggested that BHDQ normalized the alanine aminotransferase,aspartate aminotransferase,and gamma-glutamyl transpeptidase in serum.We also observed an improvement in liver tissue morphology related to BHDQ.Animals with CCl4-induced liver injuries treated with BHDQ had less oxidative stress compared to animals with CCl4-induced liver injury.BHDQ promoted activation changes in superoxide dismutase,catalase,glutathione peroxidase,glutathione reductase,and glutathione transferase on control values in animals with CCl4-induced liver injury.BHDQ also activated gene transcription in Sod1 and Gpx1 via nuclear factor erythroid 2-related factor 2 and forkhead box protein O1 factors.Therefore,the compound of concern has a hepatoprotective effect by inhibiting the development of necrotic processes in the liver tissue,through antioxidation.

Roles of Protein Kinase C and Fructose in Hepatic Injury Caused by Obstructive Jaundice

Summary： The regulating mechanism in hepatic injury caused by obstructive jaundice （OJ） was examined in this study. Rat hepatocytes were harvested by in situ collagenase perfusion and subjected to primary culture. The heptocytes were pre-treated with various concentrations of protein kinase C （PKC） agonist PMA and its inhibitor chelerythrine and cultured for 20 min. After the treatment, 50μmol/L glycochenodeoxycholate （GCDC） was added and the cells were cultured for an additional 24 h. Cells were then detected by flow cytometry （FCM） and TUNEL. After hepatocytes were treated with different concentrations of fructose and 100μM GCDC, the cells were examined by FCM and TUNEL. Experimental obstructive jaundice （BDL） was induced by double ligation of the bile duct. After BDL, the rats were fed with or without fructos and sacrificed 3, 7, 14 and 21 days after the ligation. The apoptotic status was observed in liver of all rats with TUNEL and PKC protein in liver of OJ was studied by immunohistochemical method. Our results showed that PMA increased GCDC-induced apoptosis and chelerythrine decreased GCSX-induced apoptosis in a concentration-dependent manner. After the treatment with fructose of different concentrations, 100μM GCDC decreased the apoptotic rate and the apoptotic rate decreased with the increase of fructose concentration. The apoptotic rate of liver was related to the time of OJ. Without the treatment of fructose, PKC and apoptosis index （AI） were highest 14 days after the bile duct ligation. With the treatment of fructose, apoptosis index （AI） and PKC were decreased from the 14th day after the bile duct ligation. It is concluded that PKC is involved in the regulation of apoptosis in the liver cells with OJ and plays important roles in the development and progression of liver injury caused by OJ. Fructose can protect hepatocytes in the bile salt-induced apoptosis by regulating PKC.

Undifferentiated connective tissue diseases-related hepatic injury

Hepatic injury is rarely associated with undifferentiated connective tissue diseases (UCTD). We report, here, a case of a middle-aged woman with UCTD-related hepatic injury, including its case history, clinical manifestations, laboratory findings, treatment and its short-term effect. The patient was admitted to the hospital with symptoms of fatigue, anorexia, low-grade fever and skin rashes. She had a past history of left knee joint replacement. Laboratory tests showed elevated levels of serum transaminase, IgG and globulin, accelerated erythrocyte sedimentation rate, eosinophilia and a high titer of antinuclear antibodies (1:320). Imaging studies showed interstitial pneumonitis and hydropericardium. Liver biopsy showed the features which were consistent with those of connective tissue diseases-related polyangitis. After treatment with a low-dose of oral prednisone, both symptoms and laboratory findings were significantly improved. UCTD-related hepatic injury should be considered in the differential diagnosis of connective tissue diseases with abnormal liver function tests. Low- dose prednisone may effectively improve both symptoms and laboratory tests.

Polydatin ameliorates hepatic ischemia-reperfusion injury by modulating macrophage polarization

Background:Polydatin,a glucoside of resveratrol,has shown protective effects against various diseases.However,little is known about its effect on hepatic ischemia-reperfusion(I/R)injury.This study aimed to elucidate whether polydatin protects liver against I/R-induced injury and to explore the underlying mechanism.Methods:After gavage feeding polydatin once daily for a week,mice underwent a partial hepatic I/R procedure.Serum alanine aminotransferase(ALT)/aspartate aminotransferase(AST),hematoxylin-eosin(H&E)and TdT-mediated dUTP nick-end labeling(TUNEL)staining were used to evaluate liver injury.The severity related to the inflammatory response and reactive oxygen species(ROS)production was also investigated.Furthermore,immunofluorescence and Western blotting were used to detect macrophage polarization and the NF-κB signaling pathway in macrophages.Results:Compared with the I/R group,polydatin pretreatment significantly attenuated I/R-induced liver damage and apoptosis.The oxidative stress marker(dihydroethidium fluorescence,malondialdehyde,superoxide dismutase and glutathione peroxidase)and I/R related inflammatory cytokines(interleukin1β,interleukin-10 and tumor necrosis factor-α)were significantly suppressed after polydatin treatment.In addition,the result of immunofluorescence indicated that polydatin reduced the polarization of macrophages toward M1 macrophages both in vivo and in vitro.Western blotting showed that polydatin inhibited the pro-inflammatory function of RAW264.7 via down-regulating the NF-κB signaling pathway.Conclusions:Polydatin protects the liver from I/R injury by remodeling macrophage polarization via NFκB signaling.

Research progress of lncRNA and miRNA in hepatic ischemia-reperfusion injury

Background:Hepatic ischemia-reperfusion injury(HIRI)is a common complication of liver surgeries,such as hepatectomy and liver transplantation.In recent years,several non-coding RNAs(nc RNAs)including long non-coding RNAs(lnc RNAs)and micro RNAs(mi RNAs)have been identified as factors involved in the pathological progression of HIRI.In this review,we summarized the latest research on lnc RNAs,mi RNAs and the lnc RNA-mi RNA regulatory networks in HIRI.Data sources:The Pub Med and Web of Science databases were searched for articles published up to December 2021 using the following keywords:“hepatic ischemia-reperfusion injury”,“lnc RNA”,“long noncoding RNA”,“mi RNA”and“micro RNA”.The bibliography of the selected articles was manually screened to identify additional studies.Results:The mechanism of HIRI is complex,and involves multiple lnc RNAs and mi RNAs.The roles of lnc RNAs such as AK139328,CCAT1,MALAT1,TUG1 and NEAT1 have been established in HIRI.In addition,numerous mi RNAs are associated with apoptosis,autophagy,oxidative stress and cellular inflammation that accompany HIRI pathogenesis.Based on the literature,we conclude that four lnc RNA-mi RNA regulatory networks mediate the pathological progression of HIRI.Furthermore,the expression levels of some lnc RNAs and mi RNAs undergo significant changes during the progression of HIRI,and thus are potential prognostic markers and therapeutic targets.Conclusions:Complex lnc RNA-mi RNA-m RNA networks regulate HIRI progression through mutual activation and antagonism.It is necessary to screen for more HIRI-associated lnc RNAs and mi RNAs in order to identify novel therapeutic targets.

Non-coding RNAs:The potential biomarker or therapeutic target in hepatic ischemia-reperfusion injury

Hepatic ischemia-reperfusion injury(HIRI)is the major complication of liver surgery and liver transplantation,that may increase the postoperative morbidity,mortality,tumor progression,and metastasis.The underlying mechanisms have been extensively investigated in recent years.Among these,oxidative stress,inflammatory responses,immunoreactions,and cell death are the most studied.Non-coding RNAs(ncRNAs)are defined as the RNAs that do not encode proteins,but can regulate gene expressions.In recent years,ncRNAs have emerged as research hotspots for various diseases.During the progression of HIRI,ncRNAs are differentially expressed,while these dysregulations of ncRNAs,in turn,have been verified to be related to the above pathological processes involved in HIRI.ncRNAs mainly contain microRNAs,long ncRNAs,and circular RNAs,some of which have been reported as biomarkers for early diagnosis or assessment of liver damage severity,and as therapeutic targets to attenuate HIRI.Here,we briefly summarize the common pathophysiology of HIRI,describe the current knowledge of ncRNAs involved in HIRI in animal and human studies,and discuss the potential of ncRNA-targeted therapeutic strategies.Given the scarcity of clinical trials,there is still a long way to go from pre-clinical to clinical application,and further studies are needed to uncover their potential as therapeutic targets.