Angiotensin-converting enzyme 2 and hepatic SARS-CoV-2 infection:Regulation,association,and therapeutic implications

Severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)enters host cells via the angiotensin-converting enzyme 2(ACE2)receptor.Mounting evidence has indicated the presence of hepatic SARS-CoV-2 infection and liver injury in pa-tients with coronavirus disease 2019(COVID-19).Understanding the mechanisms of hepatic SARS-CoV-2 infection is crucial for addressing COVID-19–related liver pathology and developing targeted therapies.This editorial discusses the signi-ficance of ACE2 in hepatic SARS-CoV-2 infection,drawing on the research by Jacobs et al.Their findings indicate that hepatic ACE2 expression,frequency of hepatic SARS-CoV-2 infection,and severity of liver injury are elevated in patients with pre-existing chronic liver diseases.These data suggest that hepatic ACE2 could be a promising therapeutic target for COVID-19.

Angiotensin-converting enzyme 2 alleviates liver fibrosis through the renin-angiotensin system

The present letter to the editor is related to the study titled‘Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells’.Angiotensin-converting enzyme 2 can alleviate liver fibrosis by regulating autophagy of hepatic stellate cells and affecting the renin-angiotensin system.

Hepatic angiotensin-converting enzyme 2 expression in metabolic dysfunction-associated steatotic liver disease and in patients with fatal COVID-19

BACKGROUND Metabolic dysfunction-associated steatotic liver disease(MASLD),characterised by hepatic lipid accumulation,causes inflammation and oxidative stress accompanied by cell damage and fibrosis.Liver injury(LI)is also frequently reported in patients hospitalised with coronavirus disease 2019(COVID-19),while preexisting MASLD increases the risk of LI and the development of COVID-19-associated cholangiopathy.Mechanisms of injury at the cellular level remain unclear,but it may be significant that severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)which causes COVID-19,uses angiotensin-converting expression enzyme 2(ACE2),a key regulator of the‘anti-inflammatory’arm of the renin-angiotensin system,for viral attachment and host cell invasion.AIM To determine if hepatic ACE2 levels are altered during progression of MASLD and in patients who died with severe COVID-19.METHODS ACE2 protein levels and localisation,and histological fibrosis and lipid droplet accumulation as markers of MASLD were determined in formalin-fixed liver tissue sections across the MASLD pathological spectrum(isolated hepatocellular steatosis,metabolic dysfunction-associated steatohepatitis(MASH)+/-fibrosis,end-stage cirrhosis)and in post-mortem tissues from patients who had died with severe COVID-19,using ACE2 immunohistochemistry and haematoxylin and eosin and picrosirius red staining of total collagen and lipid droplet areas,followed by quantification using machine learning-based image pixel classifiers.RESULTS ACE2 staining is primarily intracellular and concentrated in the cytoplasm of centrilobular hepatocytes and apical membranes of bile duct cholangiocytes.Strikingly,ACE2 protein levels are elevated in non-fibrotic MASH compared to healthy controls but not in the progression to MASH with fibrosis and in cirrhosis.ACE2 protein levels and histological fibrosis are not associated,but ACE2 and liver lipid droplet content are significantly correlated across the MASLD spectrum.Hepatic ACE2 levels are also increased in COVID-19 patients,especially those showing evidence of LI,but are not correlated with the presence of SARS-CoV-2 virus in the liver.However,there is a clear association between the hepatic lipid droplet content and the presence of the virus,suggesting a possible functional link.CONCLUSION Hepatic ACE2 levels were elevated in nonfibrotic MASH and COVID-19 patients with LI,while lipid accumulation may promote intra-hepatic SARS-CoV-2 replication,accelerating MASLD progression and COVID-19-mediated liver damage.

Extracellular vesicles and angiotensin-converting enzyme 2 in COVID-19 disease

Extracellular vesicles(EVs)are membranous vesicular structures released from almost all eukaryotic cell types under different physiological or pathological conditions.Growing evidence demonstrates that EVs can serve as mediators of intercellular communication between donor and recipient cells or microorganism-infected and noninfected cells.Coronavirus disease 2019(COVID-19)disease is caused by infection of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)of host cells in the respiratory system and various extra-pulmonary tissue/organs,resulting in complications of multiple organ systems.As the cell surface receptor,angiotensin-converting enzyme 2(ACE2)mediates cellular entry of SARS-CoV-2 into the host cells in patients with COVID-19.Recent studies have found that ACE2 can be released with EVs,which have been shown to interfere with the entry of the virus into host cells and thus may be involved in COVID-19 pathophysiology.In addition,ACE2,neprilysin(NEP),and thimet oligopeptidase(TOP)are the key enzymes that regulate angiotensin metabolism by converting angiotensin II or angiotensin I to angiotensin 1-7,the latter of which has protective effects in counterbalancing the harmful effects of angiotensin II in COVID-19 disease.This review summarizes the recent research progress regarding EV-associated ACE2,NEP,and TOP and the perspectives of their potential involvement in the pathophysiology of COVID-19 disease.

Role of renin-angiotensin system/angiotensin converting enzyme-2 mechanism and enhanced COVID-19 susceptibility in type 2 diabetes mellitus

Coronavirus disease 2019(COVID-19)is a disease that caused a global pandemic and is caused by infection of severe acute respiratory syndrome coronavirus 2 virus.It has affected over 768 million people worldwide,resulting in approx-imately 6900000 deaths.High-risk groups,identified by the Centers for Disease Control and Prevention,include individuals with conditions like type 2 diabetes mellitus(T2DM),obesity,chronic lung disease,serious heart conditions,and chronic kidney disease.Research indicates that those with T2DM face a hei-ghtened susceptibility to COVID-19 and increased mortality compared to non-diabetic individuals.Examining the renin-angiotensin system(RAS),a vital regulator of blood pressure and pulmonary stability,reveals the significance of the angiotensin-converting enzyme(ACE)and ACE2 enzymes.ACE converts angiotensin-I to the vasoconstrictor angiotensin-II,while ACE2 counters this by converting angiotensin-II to angiotensin 1-7,a vasodilator.Reduced ACE2 exp-ression,common in diabetes,intensifies RAS activity,contributing to conditions like inflammation and fibrosis.Although ACE inhibitors and angiotensin receptor blockers can be therapeutically beneficial by increasing ACE2 levels,concerns arise regarding the potential elevation of ACE2 receptors on cell membranes,potentially facilitating COVID-19 entry.This review explored the role of the RAS/ACE2 mechanism in amplifying severe acute respiratory syndrome cor-onavirus 2 infection and associated complications in T2DM.Potential treatment strategies,including recombinant human ACE2 therapy,broad-spectrum antiviral drugs,and epigenetic signature detection,are discussed as promising avenues in the battle against this pandemic.

Double enzyme mimetic activities of multifunctional Ag nanoparticle-decorated Co_(3)V_(2)O_(8)hollow hexagonal prismatic pencils for application in colorimetric sensors and disinfection

Since the catalytic activity of most nanozymes is still far lower than the corresponding natural enzymes,there is urgent need to discover novel highly efficient enzyme-like materials.In this work,Co_(3)V_(2)O_(8)with hollow hexagonal prismatic pencil structures were prepared as novel artificial enzyme mimics.They were then decorated by photo-depositing Ag nanoparticles(Ag NPs)on the surface to further improve its catalytic activities.The Ag NPs decorated Co_(3)V_(2)O_(8)(ACVPs)showed both excellent oxidase-and peroxidase-like catalytic activities.They can oxidize the colorless 3,3’,5,5’-tetramethylbenzidine rapidly to induce a blue change.The enhanced enzyme mimetic activities can be attributed to the surface plasma resonance(SPR)effect of Ag NPs as well as the synergistic catalytic effect between Ag NPs and Co_(3)V_(2)O_(8),accelerating electron transfer and promoting the catalytic process.ACVPs were applied in constructing a colorimetric sensor,validating the occurrence of the Fenton reaction,and disinfection,presenting favorable catalytic performance.The enzyme-like catalytic mechanism was studied,indicating the chief role of⋅O_(2)-radicals in the catalytic process.This work not only discovers a novel functional material with double enzyme mimetic activity but also provides a new insight into exploiting artificial enzyme mimics with highly efficient catalytic ability.

Angiotensin-converting enzyme 2 improves liver fibrosis in mice by regulating autophagy of hepatic stellate cells

BACKGROUND Liver fibrosis is the common pathological process associated with the occurrence and development of various chronic liver diseases.At present,there is still a lack of effective prevention and treatment methods in clinical practice.Hepatic stellate cell(HSC)plays a key role in liver fibrogenesis.In recent years,the study of liver fibrosis targeting HSC autophagy has become a hot spot in this research field.Angiotensin-converting enzyme 2(ACE2)is a key negative regulator of reninangiotensin system,and its specific molecular mechanism on autophagy and liver fibrosis needs to be further explored.AIM To investigate the effect of ACE2 on hepatic fibrosis in mice by regulating HSC autophagy through the Adenosine monophosphate activates protein kinases(AMPK)/mammalian target of rapamycin(mTOR)pathway.METHODS Overexpression of ACE2 in a mouse liver fibrosis model was induced by injection of liver-specific recombinant adeno-associated virus ACE2 vector(rAAV2/8-ACE2).The degree of liver fibrosis was assessed by histopathological staining and the biomarkers in mouse serum were measured by Luminex multifactor analysis.The number of apoptotic HSCs was assessed by terminal deoxynucleoitidyl transferase-mediated dUTP nick-end labeling(TUNEL)and immunofluorescence staining.Transmission electron microscopy was used to identify the changes in the number of HSC autophagosomes.The effect of ACE2 overexpression on Wu Y et al.ACE2 improves liver fibrosis through autophagy WJG https://www.wjgnet.com 4976 September 7,2023 Volume 29 Issue 33 autophagy-related proteins was evaluated by multicolor immunofluorescence staining.The expression of autophagy-related indicators and AMPK pathway-related proteins was measured by western blotting.RESULTS A mouse model of liver fibrosis was successfully established after 8 wk of intraperitoneal injection of carbon tetrachloride(CCl4).rAAV2/8-ACE2 administration reduced collagen deposition and alleviated the degree of liver fibrosis in mice.The serum levels of platelet-derived growth factor,angiopoietin-2,vascular endothelial growth factor and angiotensin II were decreased,while the levels of interleukin(IL)-10 and angiotensin-(1-7)were increased in the rAAV2/8-ACE2 group.In addition,the expression of alpha-smooth muscle actin,fibronectin,and CD31 was down-regulated in the rAAV2/8-ACE2 group.TUNEL and immunofluorescence staining showed that rAAV2/8-ACE2 injection increased HSC apoptosis.Moreover,rAAV2/8-ACE2 injection notably decreased the number of autophagosomes and the expression of autophagy-related proteins(LC3I,LC3II,Beclin-1),and affected the expression of AMPK pathway-related proteins(AMPK,p-AMPK,p-mTOR).CONCLUSION ACE2 overexpression can inhibit HSC activation and promote cell apoptosis by regulating HSC autophagy through the AMPK/mTOR pathway,thereby alleviating liver fibrosis and hepatic sinusoidal remodeling.

Increasing angiotensin-converting enzyme(ACE)2/ACE axes ratio alleviates early pulmonary vascular remodeling in a porcine model of acute pulmonary embolism with cardiac arrest

BACKGROUND:Acute pulmonary embolism(APE)with cardiac arrest(CA)is characterized by high mortality in emergency due to pulmonary arterial hypertension(PAH).This study aims to determine whether early pulmonary artery remodeling occurs in PAH caused by massive APE with CA and the protective effects of increasing angiotensin-converting enzyme(ACE)2-angiotensin(Ang)(1-7)-Mas receptor axis and ACE-Ang II-Ang II type 1 receptor(AT1)axis(ACE2/ACE axes)ratio on pulmonary artery lesion after return of spontaneous circulation(ROSC).METHODS:To establish a porcine massive APE with CA model,autologous thrombus was injected into the external jugular vein until mean arterial pressure dropped below 30 mmHg(1 mmHg=0.133 kPa).Cardiopulmonary resuscitation and thrombolysis were delivered to regain spontaneous circulation.Pigs were divided into four groups of five pigs each:control group,APE-CA group,ROSC-saline group,and ROSC-captopril group,to examine the endothelial pathological changes and expression of ACE2/ACE axes in pulmonary artery with or without captopril.RESULTS:Histological analysis of samples from the APE-CA and ROSC-saline groups showed that pulmonary arterioles were almost completely occluded by accumulated endothelial cells.Western blotting analysis revealed a decrease in the pulmonary arterial ACE2/ACE axes ratio and increases in angiopoietin-2/angiopoietin-1 ratio and expression of vascular endothelial growth factor(VEGF)in the APE-CA group compared with the control group.Captopril significantly suppressed the activation of angiopoietin-2/angiopoietin-1 and VEGF in plexiform lesions formed by proliferative endothelial cells after ROSC.Captopril also alleviated endothelial cell apoptosis by increasing the B-cell lymphoma-2(Bcl-2)/Bcl-2-associated X(Bax)ratio and decreasing cleaved caspase-3 expression.CONCLUSION:Increasing the ACE2/ACE axes ratio may ameliorate pulmonary arterial remodeling by inhibiting the apoptosis and proliferation of endothelial cells after ROSC induced by APE.

New perspectives on angiotensin-converting enzyme 2 and its related diseases

Since the worldwide outbreak of coronavirus disease 2019,angiotensin-converting enzyme 2(ACE2)has received widespread attention as the cell receptor of the severe acute respiratory syndrome coronavirus 2 virus.At the same time,as a key enzyme in the renin-angiotensin-system,ACE2 is considered to be an endogenous negative regulator of vasoconstriction,proliferation,fibrosis,and proinflammation caused by the ACE-angiotensin II-angiotensin type 1 receptor axis.ACE2 is now implicated as being closely connected to diabetes,cardiovascular,kidney,and lung diseases,and so on.This review covers the available information on the host factors regulating ACE2 and discusses its role in a variety of pathophysiological conditions in animal models and humans.

Angiotensin-converting enzyme 2 connects COVID-19 with cancer and cancer immunotherapy

The coronavirus disease 2019(COVID-19)pandemic caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)has resulted in more than two million deaths.Underlying diseases,including cancer,are high-risk factors for severe COVID-19 outcomes.Angiotensin-converting enzyme 2(ACE2),as a SARS-CoV-2 host cell receptor,plays a crucial role in SARS-CoV-2 invading human cells.ACE2 also has significant associations with cancer.Recent studies showed that ACE2 was inversely correlated with the activities of multiple oncogenic pathways and tumor progression phenotypes,and was positively correlated with antitumor immune response and survival prognosis in diverse cancers,suggesting a potential protective role of ACE2 in cancer progression.Positive expression of ACE2 is also correlated with programmed death-ligand 1(PD-L1)in cancer.The positive associations of ACE2 expression with antitumor immune signatures and PD-L1 expression indicate that ACE2 expression is a positive predictor for the response to immune checkpoint inhibitors(ICIs).This was evidenced in multiple cancer cohorts treated with ICIs.Thus,ACE2 may build potential connections between COVID-19 and cancer and cancer immunotherapy.The potential connections suggest that ACE2 inhibitors may not be a good option for treating COVID-19 patients with cancer,particularly in cancer patients who are receiving immunotherapy.Furthermore,the relationships between ACE2,COVID-19,and cancer are worth confirming by more experimental and clinical data,considering that many cancer patients are at high risk for COVID-19.

Angiotensin-converting enzyme 2 receptors,chronic liver diseases,common medications,and clinical outcomes in coronavirus disease 2019 patients

The severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),the virus responsible for coronavirus disease 2019(COVID-19),enters affected cells through the angiotensin-converting enzyme 2(ACE2)receptor,which is highly expressed in type II alveolar cells,enterocytes,and cholangiocytes.SARS-CoV-2 infection causes fever,dry cough,and breathing difficulty,which can progress to respiratory distress due to interstitial pneumonia,and hepatobiliary injury due to COVID-19 is increasingly recognized.The hepatobiliary injury may be evident at presentation of the disease or develop during the disease progression.The development of more severe clinical outcomes in patients with chronic liver diseases(CLD)with or without cirrhosis infected with SARS-CoV-2 has not been elucidated.Moreover,there is limited data related to common medications that affect the disease severity of COVID-19 patients.Additionally,ACE2 receptor expression of hepatobiliary tissue related to the disease severity also have not been clarified.This review summarized the current situation regarding the clinical outcomes of COVID-19 patients with chronic liver diseases who were treated with common medications.Furthermore,the association between ACE2 receptor expression and disease severity in these patients is discussed.

Plasma Levels of Angiotensin-Converting Enzymes 1 and 2 and <i>AGTR</i>2 (T1247G and A5235G) Gene Polymorphisms Are Associated to Breast Cancer Progression

Background: Breast cancer is the most common type of cancer among women. Diagnosed and treated timely, patients may have good prognostics. In Brazil, in 2012, the estimate of new cases was 52,680 and the number of registered deaths in 2012 was 12,852. The Renin-Angiotensin System (RAS) is known for its role in arterial hypertension and in other cardiovascular diseases. Angiotensin-Converting Enzyme 2 (ACE2) is the key to Ang-(1-7) formation, and counterbalances the ACE1/AngII/AGTR1 axis actions. RAS components have complex interactions with different tissues and their actions are not restricted to the cardiovascular system. Recently, the RAS has been associated with different types of cancers and in particular with gynecological cancers. Objectives: Our aim is to investigate possible associations between allelic distribution of two genetic polymorphisms in the AGTR2 receptor with ACEs 1 and 2 plasma levels among women with breast cancer. Patients and Methods: Patients with breast cancer were genotyped for two polymorphisms of the AGTR2 (T1247G and A5235G). Genotyping assays (TaqMan) were performed with genomic DNA extracted from blood cells. ACEs plasma level measurements were conducted in women from the breast-cancer group (N = 53). ACEs were measured in the plasma of these patients using ELISA kits. Results: SNPs genotype distribution is correlated with ACEs plasma levels. ACEs plasma levels are also correlated with clinical variables and ACE2 high levels are associated with better prognostics. Conclusions: Changes in circulating levels of ECA1/AngII ECA2/ Ang-(1-7) determine the magnitude of the inflammatory response that an individual can trigger and the variation in ACE 1 and 2 plasma level measurements in the blood of breast cancer patients suggests an association with the process of mammary carcinogenesis. Thus, the RAS may be associated with the process of mammary carcinogenesis by both genotypic variations of RAS components and by circulating levels of ACEs.

AT1a Receptor Has Interacted with Angiotensin-converting Enzymes 2 mRNA Expression in Mouse Brainstem

Objectives To examine in vivo interactions between angiotensin Ⅱ （Ang Ⅱ ） AT1 a receptor （AT1 aR）, angiotensin-converting enzymes （ACE） and ACE2 using small hairpin RNA （shRNA） gene-silencing methods in mice brainstem nucleus tractus solitarius （NTS）. Methods C57BL mice （n = 8 ） were used as animal model. Method of micro-injection in the nucleus of NTS was adopted. After ten days, mice were killed and their brain tissue were fixed and sectioned. The expression levels of AT1 aR, ACE and ACE2 mRNA at both sides of NTS were examined by in situ hybridization. Based on compared t-test, the changing for mRNA expression was examined. Results After the expression of ATlaR mRNA was significantly inhibited （61.6% ± 6.8% ） by ATlaR-shRNA, it was associated with decreases in ACE2 mRNA expression from （ 1.05 ± 0. 12） μCi/mg to （0. 74 ± 0.09 ） μCi/mg （ 29.0% ± 14. 5% , P 〈 0. 01 ） on the same side of the brainstem. ACE mRNA expression was consistent at both sides （ 0. 50 μCi/mg ± 0. 09μCi/mg and 0. 53 μCi/mg ± 0. 08 μCi/mg）, with insignificant difference （ P 〉 0. 05 ）. Conclusions The gene silencing result showed that there were interactions between brainstem AT1 aR and ACE2. ACE mRNA expression was not altered by RNA interference treatment at AT1 aR.

Effects of long-term elevated CO_2 on N_2-fixing,denitrifying and nitrifying enzyme activities in forest soils under Pinus sylvestriformis in Changbai Mountain

A study was conducted to determine the effects of elevated CO2 on soil N process at Changbai Mountain in Jilin Province, northeastern China （42°24＂N, 128°06＂E, and 738 m elevation）. A randomized complete block design of ambient and elevated CO2 was established in an open-top chamber facility in the spring of 1999. Changpai Scotch pine （Pinus sylvestris var. sylvestriformis seeds were sowed in May, 1999 and CO2 fumigation treatments began after seeds germination. In each year, the exposure started at the end of April and stopped at the end of October. Soil samples were collected in June and August 2006 and in June 2007, and soil nitrifying, denitrifying and N2-fixing enzyme activities were measured. Results show that soil nitrifying enzyme activities （NEA） in the 5-10 cm soil layer were significantly increased at elevated CO2 by 30.3% in June 2006, by 30.9% in August 2006 and by 11.3% in June 2007. Soil denitrifying enzyme activities （DEA） were significantly decreased by elevated CO2 treatment in June 2006 （P 〈 0.012） and August 2006 （P 〈 0.005） samplings in our study; no significant difference was detected in June 2007, and no significant changes in N2-fixing enzyme activity were found. This study suggests that elevated CO2 can alter soil nitrifying enzyme and denitrifying enzyme activities.

Responses of soil enzymes to long-term CO_2 enrichment in forest ecosystems of Changbai Mountains

A study was conducted to determine the responses of soil enzymes （invertase, polyphenol oxidase, catalase, and dehydrogenase） to long-term CO2 enrichment at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences （42°24＇N, 128°28＇E; 738 m in elevation） in the northeast China during 1999-2006. Three treatments of the CO2 enrichment, designed as 500 μmol·mol-1 CO2 open-top chamber （OTC）, ambient control chamber and unchambered field （approx. 370 μmol·mol^-1CO2）, were conducted with Pinus koraiensis and Pinus sylvestriformis tree species. Soil sampling was made and analyzed separately in spring, summer and autumn in 2006 after the soil enzymes were exposed to elevated CO2 concentration （500 μmol·mol^-1） for eight growing seasons. Results showed that, at elevated CO2 concentration （500 μmol·mol^-1）, the activities of invertase （except for the summer samples of P. koraiensis） presented a remarkable decline in all growing seasons, while the activities of dehydrogenase had an increase but only part of the results was remarkable; the activities of polyphenol oxidase in P. sylvestriformis rhizosphere showed a remarkable decrease; the catalase activities increased in spring, while in turn were decline in other seasons. This study also revealed that the soil enzyme activities are significantly correlated with the tree species under the CO2 enhancement.

新型倒置A^(2)/O耦联MBR组合工艺处理农村低C/N废水的研究

针对农村低C/N污水污染物和营养盐去除率差的问题,以倒置A^(2)/O耦联膜生物反应器(MBR)组合工艺为探究对象,通过控制进水污染物浓度,在中温条件下考察了有机负荷(OLR)对倒置A^(2)/O耦联MBR组合工艺处理农村低C/N污水的影响。结果表明,OLR由150 mg/L提高至450 mg/L时,总氮(TN)和溶解性磷酸盐(SOP)去除率分别由67.6%和86.6%提高至72.4%和94.3%,进一步提高OLR降低了组合工艺对污染物和营养盐的去除。此外,OLR能影响新工艺内污泥特征,提高OLR促进了胞外聚合物(EPS)分泌,尤其在OLR为600 mg/L组别内,EPS含量提高至139.6 mg/g。进水OLR对缺氧池内EPS的影响要大于其对厌氧池内EPS的影响。OLR能影响新工艺内污染物和营养盐去除相关关键酶的活性,当OLR为450 mg/L时,污染物和营养盐去除相关关键活性酶最强。研究结果为农村低C/N污水的高效处理提供了理论依据和数据支撑。

急性肺栓塞患者外周血循环ACE2和Mas表达及其对内皮损伤的影响

目的探究急性肺栓塞(APE)患者治疗前后外周血循环内皮细胞(CECs)凋亡数量及ACE2、Mas蛋白表达变化。方法收集2023年1月—2023年10月本院急诊科接收的APE患者82例,根据疾病严重程度将其分为中高危组42例、低危组40例,另选取40例于本院体检的健康受试者为对照组。取APE患者入院时、出院时及健康受试者外周血。流式细胞术分析APE患者及健康受试者CECs数量、凋亡水平。Western blotting检测CECs内凋亡蛋白Bax、Bcl2、caspase 3/9水平变化及蛋白ACE2、Mas表达变化。结果入院时中高危组、低危组患者入院时外周血CECs数量及凋亡率均显著高于对照组,且中高危组CECs数量及凋亡率均显著高于低危组水平(P<0.05)。出院时中高危组及低危组患者CECs数量及凋亡率均显著低于入院时水平(P<0.05)。入院时中高危组、低危组患者CECs中Bax/Bcl2蛋白比值、切割caspase 3/9蛋白水平显著高于对照组,且中高危组这些指标水平显著高于低危组,同时出院时中高危组、低危组患者CECs上述指标水平显著低于入院时水平(P<0.05)。进一步发现入院时中高危组、低危组CECs中ACE2、Mas水平显著低于对照组,且中高危组上述指标水平显著低于低危组(P<0.05)。结论APE患者外周血CECs数量及凋亡率显著增加,治疗后CECs数量及凋亡率减少,提示CECs可能与APE发病及预后相关,同时ACE2-Mas轴可能参与调控CECs凋亡。

补肾活血针刺法对SAMP8小鼠认知功能及海马神经元沉默信息调节因子2调控作用的研究

目的探究补肾活血针刺法对加速衰老的小鼠模型SAMP8小鼠认知功能和海马神经元沉默信息调节因子2(SIRT2)介导的内质网蛋白4B(RTN4B)/β淀粉样前体蛋白裂解酶1(BACE1)通路的影响。方法6只SAMR1小鼠为正常对照组,18只SAMP8小鼠随机分为模型对照组、针刺治疗组、非针刺治疗组,各6只。针刺治疗组血海、膈俞施捻转泻法,肾俞、百会施捻转补法,运针1 min,留针10 min;非针刺治疗组在非经非穴点进行抓捉刺激;均干预8周。通过Morris水迷宫试验评估小鼠认知功能。采用免疫组织化学染色和酶联免疫吸附试验评估海马神经元小胶质细胞的激活和β淀粉样蛋白(Aβ)沉积。通过蛋白质免疫印迹检测SIRT2途径相关蛋白SIRT2、RTN4B、BACE1和β淀粉样前体蛋白C-末端片段(APP-CTF)的表达水平。结果与正常对照组比较,模型对照组逃避潜伏期延长,目标象限停留时间减少,穿越平台次数减少(P<0.05),海马组织Aβ42和CD68阳性面积增大(P<0.01),血清Aβ42水平增高,海马组织中SIRT2、BACE1和APP-CTF表达明显增加,RTN4B表达降低(P<0.05)。与模型对照组及非针刺治疗组比较,针刺治疗组逃避潜伏期缩短[第1天:(37.80±10.42)s比(49.80±6.14)s、(44.60±7.40)s,P<0.05;第2天:(36.80±12.69)s比(48.80±5.97)s、(44.20±7.72)s,P<0.05;第3天:(38.60±9.71)s比(51.20±5.54)s、(43.60±6.46)s,P<0.05;第4天:(36.00±11.20)s比(46.40±5.81)s、(45.20±7.36)s,P<0.05;第5天:(36.60±11.37)s比(47.80±5.31)s、(43.80±9.44)s,P<0.05],目标象限停留时间增加[(7.83±0.98)s比(1.00±0.63)s、(3.33±0.52)s,P<0.05],穿越平台次数增加[(13.33±1.03)次比(3.17±1.17)次、(7.33±0.52)次,P<0.05];海马组织Aβ42和CD68阳性面积减少(P<0.01),血清Aβ42水平显著降低[(11.38±1.57)μg/mL比(23.14±2.41)μg/mL、(17.16±1.27)μg/mL,P<0.05];海马组织中SIRT2[(1.98±0.19)比(4.21±0.31)、(3.22±0.23),P<0.05或P<0.01]、BACE1[(1.81±0.14)比(2.80±0.19)、(2.43±0.13),P<0.05或P<0.01]和APP-CTF[(2.56±0.26)比(4.53±0.33)、(3.48±0.25),P<0.05或P<0.01]表达降低,RTN4B[(0.79±0.06)比(0.27±0.03)、(0.46±0.05),P<0.05或P<0.01]表达增高。结论补肾活血针刺法通过抑制SIRT2介导的RTN4B/BACE1途径,改善SAMP8小鼠的认知功能和Aβ沉积。

Timosaponin AⅢ induces drug-metabolizing enzymes by activating constitutive androstane receptor (CAR) via dephosphorylation of the EGFR signaling pathway

The current study aimed to assess the effect of timosaponin AⅢ(T-AⅢ)on drug-metabolizing enzymes during anticancer therapy.The in vivo experiments were conducted on nude and ICR mice.Following a 24-day administration of T-AⅢ,the nude mice exhibited an induction of CYP2B10,MDR1,and CYP3A11 expression in the liver tissues.In the ICR mice,the expression levels of CYP2B10 and MDR1 increased after a three-day T-AⅢ administration.The in vitro assessments with HepG2 cells revealed that T-AⅢ induced the expression of CYP2B6,MDR1,and CYP3A4,along with constitutive androstane receptor(CAR)activation.Treatment with CAR siRNA reversed the T-AⅢ-induced increases in CYP2B6 and CYP3A4 expression.Furthermore,other CAR target genes also showed a significant increase in the expression.The up-regulation of murine CAR was observed in the liver tissues of both nude and ICR mice.Subsequent findings demonstrated that T-AⅢ activated CAR by inhibiting ERK1/2 phosphorylation,with this effect being partially reversed by the ERK activator t-BHQ.Inhibition of the ERK1/2 signaling pathway was also observed in vivo.Additionally,T-AⅢ inhibited the phosphorylation of EGFR at Tyr1173 and Tyr845,and suppressed EGF-induced phosphorylation of EGFR,ERK,and CAR.In the nude mice,T-AⅢ also inhibited EGFR phosphorylation.These results collectively indicate that T-AⅢ is a novel CAR activator through inhibition of the EGFR pathway.

Serum angiotensin-converting enzyme level for evaluating significant fibrosis in chronic hepatitis B

AIM To evaluate the diagnostic performance of angiotensinconverting enzyme(ACE)on significant liver fibrosis in patients with chronic hepatitis B(CHB). METHODS In total,100 patients with CHB who underwent liver biopsy in our hospital were enrolled,and 70 patients except for 30 patients with hypertension,fatty liver or habitual alcoholic consumption were analyzed.We compared histological liver fibrosis and serum ACE levels and evaluated the predictive potential to diagnose significant liver fibrosis by comparison with several biochemical marker-based indexes such as the aspartate aminotransferase(AST)-to-platelet ratio index(APRI),the fibrosis index based on four factors(FIB-4),the Mac-2 binding protein glycosylation isomer(M2BPGi)level and the number of platelets(Plt). RESULTS Serum ACE levels showed moderately positive correlation with liver fibrotic stages(R2=0.181).Patients with significant,advanced fibrosis and cirrhosis(F2-4)had significantly higher serum ACE levels than those with early-stage fibrosis and cirrhosis(F0-1).For significant fibrosis(≥F2),the 12.8 U/L cut-off value of ACE showed 91.7%sensitivity and 75.0%specificity.The receiver-operating characteristic(ROC)curves analysis revealed that the area under the curve(AUC)value of ACE was 0.871,which was higher than that of APRI,FIB-4,M2BPGi and Plt. CONCLUSION The serum ACE level could be a novel noninvasive,easy,accurate,and inexpensive marker of significant fibrosis stage in patients with CHB.