AGK2 pre-treatment protects against thioacetamide-induced acute liver failure via regulating the MFN2-PERK axis and ferroptosis signaling pathway

Background:Acute liver failure(ALF)is an unpredictable and life-threatening critical illness.The pathological characteristic of ALF is massive necrosis of hepatocytes and lots of inflammatory cells infiltration which may lead to multiple organ failure.Methods:Animals were divided into 3 groups,normal,thioacetamide(TAA,ALF model)and TAA+AGK2.Cultured L02 cells were divided into 5 groups,normal,TAA,TAA+mitofusin 2(MFN2)-siRNA,TAA+AGK2,and TAA+AGK2+MFN2-siRNA groups.The liver histology was evaluated with hematoxylin and eosin staining,inositol-requiring enzyme 1(IRE1),activating transcription factor 6β(ATF6β),protein kinase R(PKR)-like endoplasmic reticulum kinase(PERK)and phosphorylated-PERK(p-PERK).C/EBP homologous protein(CHOP),reactive oxygen species(ROS),MFN2 and glutathione peroxidase 4(GPX4)were measured with Western blotting,and cell viability and liver chemistry were also measured.Mitochondriaassociated endoplasmic reticulum membranes(MAMs)were measured by immunofluorescence.Results:The liver tissue in the ALF group had massive inflammatory cell infiltration and hepatocytes necrosis,which were reduced by AGK2 pre-treatment.In comparison to the normal group,apoptosis rate and levels of IRE1,ATF6β,p-PERK,CHOP,ROS and Fe2+in the TAA-induced ALF model group were significantly increased,which were decreased by AGK2 pre-treatment.The levels of MFN2 and GPX4 were decreased in TAA-induced mice compared with the normal group,which were enhanced by AGK2 pretreatment.Compared with the TAA-induced L02 cell,apoptosis rate and levels of IRE1,ATF6β,p-PERK,CHOP,ROS and Fe2+were further increased and levels of MFN2 and GPX4 were decreased in the MFN2-siRNA group.AGK2 pre-treatment decreased the apoptosis rate and levels of IRE1,ATF6β,p-PERK,CHOP,ROS and Fe2+and enhanced the protein expression of MFN2 and GPX4 in MFN2-siRNA treated L02 cell.Immunofluorescence observation showed that level of MAMs was promoted in the AGK2 pre-treatment group when compared with the TAA-induced group in both mice and L02 cells.Conclusions:The data suggested that AGK2 pre-treatment had hepatoprotective role in TAA-induced ALF via upregulating the expression of MFN2 and then inhibiting PERK and ferroptosis pathway in ALF.

Sirtuin1 attenuates acute liver failure by reducing reactive oxygen species via hypoxia inducible factor 1α

BACKGROUND The occurrence and development of acute liver failure(ALF)is closely related to a series of inflammatory reactions,such as the production of reactive oxygen species(ROS).Hypoxia inducible factor 1α(HIF-1α)is a key factor that regulates oxygen homeostasis and redox,and the stability of HIF-1αis related to the ROS level regulated by Sirtuin(Sirt)family.The activation of Sirt1 will lead to a powerful antioxidant defense system and therapeutic effects in liver disease.However,little is known about the relationship between HIF-1αand Sirt1 in the process of ALF and the molecular mechanism.AIM To investigate whether HIF-1αmay be a target of Sirt1 deacetylation and what the effects on ALF are.METHODS Mice were administrated lipopolysaccharide(LPS)/D-gal and exposed to hypoxic conditions as animal model,and resveratrol was used as an activator of Sirt1.The cellular model was established with L02 cells stimulated by LPS.N-acetyl-Lcysteine was used to remove ROS,and the expression of Sirt1 was inhibited by nicotinamide.Western blotting was used to detect Sirt1 and HIF-1αactivity and related protein expression.The possible signaling pathways involved were analyzed by immunofluorescent staining,co-immunoprecipitation,dihydroethidium staining,and Western blotting.RESULTS Compared with mice stimulated with LPS alone,the expression of Sirt1 decreased,the level of HIF-1αacetylation increased in hypoxic mice,and the levels of carbonic anhydrase 9 and Bcl-2-adenovirus E1B interacting protein 3 increased significantly,which was regulated by HIF-1α,indicating an increase of HIF-1αactivity.Under hypoxia,the down-regulation of Sirt1 activated and acetylated HIF-1αin L02 cells.The inhibition of Sirt1 significantly aggravated this effect and the massive production of ROS.The regulation of ROS was partly through peroxisome proliferatoractivated receptor alpha or AMP-activated protein kinase.Resveratrol,a Sirt1 activator,effectively relieved ALF aggravated by hypoxia,the production of ROS,and cell apoptosis.It also induced the deacetylation of HIF-1αand inhibited the activity of HIF-1α.CONCLUSION Sirt1 may have a protective effect on ALF by inducing HIF-1α deacetylation to reduce ROS.

Bladder perforation injury after percutaneous peritoneal dialysis catheterization:A case report

BACKGROUND Insertion of a catheter into the bladder is a rare complication of peritoneal dialysis(PD),and is mainly related to surgical injury.This paper reports a case of bladder perforation that was caused by percutaneous PD catheterization.CASE SUMMARY A 64-year-old man underwent percutaneous PD catheterization for end-stage renal disease.On the second day after the operation,urgent urination and gross hematuria occurred.Urinalysis showed the presence of red and white blood cells.Empirical anti-infective treatment was given.On the third day after the operation,urgent urination occurred during PD perfusion.Ultrasound showed that the PD catheter was located in the bladder,and subsequent computed tomography(CT)showed that the PD catheter moved through the anterior wall into the bladder.The PD catheter was withdrawn from the bladder and catheterization was retained.Repeat CT on the fourth day after the operation showed that the PD catheter was removed from the bladder,but there was poor catheter function.The PD catheter was removed and the patient was changed to hemodialysis.CT cystography showed that the bladder healed well and the patient was discharged 14 d after the operation.CONCLUSION Bladder perforation injury should be considered and treated timeously in case of bladder irritation during and after percutaneous PD catheterization.The use of Doppler ultrasound and other related technologies may reduce the incidence of such complications.

Sulforaphane,an NRF2 agonist,alleviates ferroptosis in acute liver failure by regulating HDAC6 activity

Objective Acute liver failure(ALF)is characterized by severe liver dysfunction,rapid progression and high mortality and is difficult to treat.Studies have found that sulforaphane(SFN),a nuclear factor E2-related factor 2(NRF2)agonist,has anti-inflammatory,antioxidant and anticancer effects,and has certain protective effects on neurodegenerative diseases,cancer and liver fibrosis.This paper aimed to explore the protective effect of SFN in ALF and it possible mechanisms of action.Methods Lipopolysaccharide and D-galactosamine were used to induce liver injury in vitro and in vivo.NRF2 agonist SFN and histone deacetylase 6(HDAC6)inhibitor ACY1215 were used to observe the protective effect and possible mechanisms of SFN in ALF,respectively.Cell viability,lactate dehydrogenase(LDH),Fe2+,glutathione(GSH)and malondialdehyde(MDA)were detected.The expression of HDAC6,NRF2,glutathione peroxidase 4(GPX4),acyl-CoA synthetase long-chain family member 4(ACSL4)and solute carrier family 7 member 11(SLC7A11)were detected by Western blotting and immunofluorescence.Results Our results show that NRF2 was activated by SFN.LDH,Fe2+,MDA and ACSL4 were downregulated,while GSH,GPX4 and SLC7A11 were upregulated by SFN in vitro and in vivo,indicating the inhibitory effect of SFN on ferroptosis.Additionally,HDAC6 expression was decreased in the SFN group,indicating that SFN could downregulate the expression of HDAC6 in ALF.After using the HDAC6 inhibitor,ACY1215,SFN further reduced HDAC6 expression and inhibited ferroptosis,indicating that SFN may inhibit ferroptosis by regulating HDAC6 activity.Conclusion SFN has a protective effect on ALF,and the mechanism may include reduction of ferroptosis through the regulation of HDAC6.

心肺转流对冠状动脉旁路移植术后脑微栓子数量及认知功能障碍发生率的影响

背景手术后认知功能障碍（postoperative cognitive dysfunction，POCD）是冠状动脉旁路移植手术（CABG）后常见的并发症。心肺转流术（CPB）中的脑微栓子被认为是诱发POCD的一个重要原因。我们研究不使用体外循环的冠状动脉移植术能否减少中国人群CABG术后脑微栓子的数量及POCD发生率。方法227例患者参与了本次前瞻性队列研究。其中59例患者来自CPB组，另外168例加入非体外循环组。使用经颅多普勒超声持续测定双侧大脑中动脉内脑微栓子情况。分别在手术前、手术后1周及手术后3个月使用一套神经心理量表评估认知功能，该量表包括了7项测验，共9个小项。根据国际POCDl的研究定义来诊断POCD。结果CPB组和非体外循环组患者发生脑微栓子的平均数分别为430（155～2088）和2（0。66）（P〈0．001）。两组COPD的发生率在手术后I周及3个月均无明显差异，在第1周时CPB组发生率为55．2％（32／58，95％可信区间为41．5％-68．3％），非体外循环组发生率为47％（78/166，95％可信区间为39．2％～54．9％，P=0．283）；手术后3个月发生率分别为6．4％13／47，（1．3％～17．5％）]和13．1％[16／122，（7．7％-20．4％，P=0．214）]。年龄增长以及手术后住院天数缩短可能与手术后1周认知功能障碍独立相关。另外年龄增长以及糖尿病史则与手术后3个月认知功能障碍独立相关。CPB或者脑微栓子与POCD的发生率无显著相关性。结论在中国人群的CABG手术中，不使用CPB可明显减h脑微栓子数目，但并不降低手术后1周或手术后3个月时POCD的发生率。CPB或脑微栓子与POCD的发生率无明显相关性。