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.

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.

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.

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.

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.

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.

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.

Histopathological impact of SARS-CoV-2 on the liver:Cellular damage and long-term complications

Coronavirus disease 2019(COVID-19),caused by the highly pathogenic severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),primarily impacts the respiratory tract and can lead to severe outcomes such as acute respiratory distress syndrome,multiple organ failure,and death.Despite extensive studies on the pathogenicity of SARS-CoV-2,its impact on the hepatobiliary system remains unclear.While liver injury is commonly indicated by reduced albumin and elevated bilirubin and transaminase levels,the exact source of this damage is not fully understood.Proposed mechanisms for injury include direct cytotoxicity,collateral damage from inflammation,drug-induced liver injury,and ischemia/hypoxia.However,evidence often relies on blood tests with liver enzyme abnormalities.In this comprehensive review,we focused solely on the different histopathological manifestations of liver injury in COVID-19 patients,drawing from liver biopsies,complete autopsies,and in vitro liver analyses.We present evidence of the direct impact of SARS-CoV-2 on the liver,substantiated by in vitro observations of viral entry mechanisms and the actual presence of viral particles in liver samples resulting in a variety of cellular changes,including mitochondrial swelling,endoplasmic reticulum dilatation,and hepatocyte apoptosis.Additional ly,we describe the diverse liver pathology observed during COVID-19 infection,encompassing necrosis,steatosis,cholestasis,and lobular inflammation.We also discuss the emergence of long-term complications,notably COVID-19-related secondary sclerosing cholangitis.Recognizing the histopathological liver changes occurring during COVID-19 infection is pivotal for improving patient recovery and guiding decision-making.

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.

Ferrets: A powerful model of SARS-CoV-2

The rapid spread of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2) in recent years not only caused a global pandemic but resulted in enormous social,economic,and health burdens worldwide.Despite considerable efforts to combat coronavirus disease 2019(COVID-19),various SARS-CoV-2 variants have emerged,and their underlying mechanisms of pathogenicity remain largely unknown.Furthermore,effective therapeutic drugs are still under development.Thus,an ideal animal model is crucial for studying the pathogenesis of COVID-19 and for the preclinical evaluation of vaccines and antivirals against SARS-CoV-2 and variant infections.Currently,several animal models,including mice,hamsters,ferrets,and nonhuman primates(NHPs),have been established to study COVID-19.Among them,ferrets are naturally susceptible to SARS-CoV-2 infection and are considered suitable for COVID-19 study.Here,we summarize recent developments and application of SARS-CoV-2 ferret models in studies on pathogenesis,therapeutic agents,and vaccines,and provide a perspective on the role of these models in preventing COVID-19 spread.

ACE and ACE2 in kidney disease

Renin angiotensin system （RAS） activation has a significant influence on renal disease progression. The classical angiotensin-converting enzyme （ACE）-angio-tensin Ⅱ （Ang Ⅱ）-Ang Ⅱ type 1 （AT1） axis is considered to control the effects of RAS activation on renal disease. However, since its discovery in 2000 ACE2 has also been demonstrated to have a significant impact on the RAS. The synthesis and catabolism of Ang Ⅱ are regulated via a complex series of interactions, which involve ACE and ACE2. In the kidneys, ACE2 is expressed in the proximal tubules and less strongly in the glomeruli. The synthesis of inactive Ang 1-9 from Ang Ⅰ and the catabolism of Ang Ⅱ to produce Ang 1-7 are the main functions of ACE2. Ang 1-7 reduces vasoconstriction, water retention, salt intake, cell proliferation, and reactive oxygen stress, and also has a renoprotective effect. Thus, in the non-classical RAS the ACE2-Ang 1-7-Mas axis counteracts the ACE-Ang Ⅱ-AT1 axis. This review examines recent human and animal studies about renal ACE and ACE2.

Angiotensin-converting enzyme 2(ACE2):SARS-CoV-2 receptor and RAS modulator

The coronavirus disease 2019(COVID-19)outbreak is caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Angiotensin-converting enzyme 2(ACE2)was rapidly identified as the critical functional receptor for SARS-CoV-2.ACE2 is well-known as a counter-regulator of the renin-angiotensin system(RAS)and plays a key role in the cardiovascular system.Given that ACE2 functions as both a SARS-CoV-2 receptor and a RAS modulator,the treatment for COVID-19 presents a dilemma of how to limit virus entry but protect ACE2 physiological functions.Thus,an in-depth summary of the recent progress of ACE2 research and its relationship to the virus is urgently needed to provide possible solution to the dilemma.Here,we summarize the complexity and interplay between the coronavirus,ACE2 and RAS(including anti-RAS drugs).We propose five novel working modes for functional receptor for SARS-CoV-2 infection and the routes of ACE2-mediated virus entering host cells,as well as its regulatory mechanism.For the controversy of anti-RAS drugs application,we also give theoretical analysis and discussed for drug application.These will contribute to a deeper understanding of the complex mechanisms of underlying the relationship between the virus and ACE2,and provide guidance for virus intervention strategies.

Angiotensin-converting enzyme 2 activation protects against pulmonary arterial hypertension through improving early endothelial function and mediating cytokines levels

Background Increasing evidences indicate that an activated renin-angiotensin system （RAS） causes an imbalance between the vasoconstrictive and vasodilator mechanisms involving the pulmonary circulation leading to the development of pulmonary arterial hypertension （PAH）. Angiotensin-converting enzyme 2 （ACE2）, a primary component of the vasoprotective axis in RAS, is recently identified that it has regulatory actions in lung pathophysiology, but the mechanism in these processes is uncertain yet. Methods Severe PAH was induced by monocrotaline injection one week following pneumonectomy in rats. The activation of ACE2 by continuous injection of resorcinolnaphthalein was studied by real time-polymerase chain reaction （RT-PCR）, Western blotting and fluorogenic peptide assay. Endothelial functions were evaluated by the response to acetylcholine and cytokines were measured by RT-PCR seven days after monocrotaline injection. The PAH-related hemodynamics and pathological changes were examined at day 21 when severe PAH was completely established. Results Resorcinolnaphthalein caused significant activation of ACE2 in both normal and diseased rats in 7 days after treatment. The pulmonary arterial pressure （PAP） started to increase at least 7 days after monocrotaline injection, and the rats developed severe PAH in 21 days with high PAP, right ventricular hypertrophy and neointimal formation. Treatment with resorcinolnaphthalein prevented these features. Resorcinolnaphthalein caused an improved endothelia-dependent vasorelaxation and decrease in proinflammatory cytokines （tumor necrosis factor （TNF）-a, monocyte chemoattractant protein-1 （MCP-1）, interleukin （IL）-6） and increase in anti-inflammatory cytokine IL-10 in the early stage of the pathogenesis. Conclusions These results demonstrated that activation of ACE2 by continuous injection of resorcinolnaphthalein prevented the development of PAH through improving early endothelial dysfunction and mediating the level of proinflammatory and anti-inflammatory cytokines.

Polymorphisms of angiotensin-converting enzyme 2 gene associated with magnitude of left ventricular hypertrophy in male patients with hypertrophic cardiomyopathy

Background Even carrying an identical gene mutation, inter- and intra-family variations have been noticed worldwide in the presence and the severity of left ventricular hypertrophy and sudden death in patients with hypertrophic cardiomyopathy （HCM）. Modifier genes may contribute to the diversity. Angiotensin-converting enzyme 2 （ACE2） gene has been established to be associated with parameters of left ventricular hypertrophy in community based male subjects. The objective of the present study was to investigate the association of ACE2 gene polymorphisms with the phenotype of HCM. Methods A total of 261 consecutive HCM patients and 609 healthy controls were enrolled into this study. The polymorphism of rs2106809 and rs6632677 were genotyped by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and confirmed by sequencing. Logistic regression model and multivariate analysis were used to determine the odds ratio （OR） and 95% confidence intervals （CO of variations of ACE2 for HCM. Results The T allele of rs2106809 and C allele of rs6632677 conferred increasing risk for HCM （OR 1.34, 95%C/ 1.01-1.77, P=0.04; OR 1.11, 95%C/ 1.03-1.21, P=0.002, respectively）, and the 2 single nucleotide polymorphisms （SNPs） were in strong linkage disequilibrium （LD）, the TC haplotype was independently associated with a higher OR for HCM （OR=1.59, 95%C/1.21-1.87） after adjusted for conventional risk factors. And the risk alleles were associated with thicker interventricular septal thickness of HCM （（20.0±6.3） mm vs （17.9±5.5） mm, P=0.03 and （21.3±5.9） mm vs （17.9±5.8） mm, P=0.04, respectively）. No association was found between the two polymorphisms with female patients with HCM. Conclusion Minor alleles of ACE2 gene might be the genetic modifier for the magnitude of left ventricular hypertrophy in male patients with HCM.

Traditional Chinese medicine for treatment of coronavirus disease 2019:a review

prevalence.A number of clinical workers and researchers have made great efforts to understand the pathogenesis and clinical characteristics and develop effective drugs for treatment.However,no effective drugs with antiviral effects on severe acute respiratory syndrome coronavirus 2 have been discovered currently.Traditional Chinese medicine(TCM)has gained abundant experience in the treatment of infectious diseases for thousands of years.In this review,the authors summarized the clinical outcome,pathogensis and current application of TCM on coronavirus disease 2019.Further,we discussed the potential mechanisms and the future research directions of TCM against severe acute respiratory syndrome coronavirus 2.

Effects of combination of irbesartan and perindopril on calcineurin expression and sarcoplasmic reticulum Ca^(2+)-ATPase activity in rat cardiac pressure-overload hypertrophy

Aim： To observe effects of angiotensin （Ang） II receptor antagonist （ATI） irbesartan and angiotensin-converting enzyme （ACE） inhibitor perindopril on rat myocardium calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity in the model of pressure-overload cardiac hypertrophy. Methods： Forty male adult Sprague Dawley rats were divided into 5 groups One group was treated by sham operation; four groups were myocardium hypertrophy cases caused by banding aortic above renal artery. Drugs were given one week after operation. Group 1： sham group, rats （n=8） were gavaged with normal saline 2 ml/（kg·d） （ig）; Group 2： control group, rats （n=8） were treated with normal saline 2 ml/（kg·d） （ig）; Group 3： rats （n=8） were given perindopril 2 mg/（kg·d） （ig）; Group 4： rats （n=8） were treated with irbesartan 20 mg/（kg·d） （ig）; Group 5： rats （n=8） were given irbesartan 20 mg/（kg·d） plus perindopril 2 mg/（kg·d） （ig）. Morphometric determination, calcineurin expression and sarcoplasmic reticulum Ca^2＋-ATPase activity were done at the end of 6 week of drug intervention. Expression of calcineurin in myocardium was detected by immunohistochemistry. Results： Left ventricular mass index （LVMI）, transverse diameter of myocardial cell （TDM）, calcineurin activity were remarkably decreased after drug intervention and this decrease was most remarkable in the combination drug therapy group. Sarcoplasmic reticulum Ca^2＋-ATPase activity was increased after drug intervention, especially in the combined drug therapy group. Calcineurin expression in myocardium was remarkably decreased after drug intervention. LVMI was positively correlated with TDM and calcineurin, negatively correlated with sarcoplasmic reticulum Ca^2＋-ATPase. Conclusion： These data suggest that irbesartan and perindopril inhibit cardiac hypertrophy through the increased activity of sarcoplasmic reticulum Ca^2＋-ATPase and decreased expression of calcineurin. Their combination had better effects on regressing of ventricular hypertrophy.

Network pharmacology studies on the effect of Chai-Ling decoction incoronavirus disease 2019

Background:Chai-Ling decoction(CLD),derived from a modification of Xiao-Chai-Hu(XCH)decoction and Wu-Ling-San(WLS)decoction,has been used to treat the early-stage of coronavirus disease 2019(COVID-19).However,the mechanisms of CLD in COVID-19 remain unknown.In this study,the potential mechanisms of CLD in COVID-19 were preliminarily investigated based on network pharmacology and molecular docking method.Methods:Initially,the active components and targets of CLD were screened based on Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform and PharmMapper database.The targets of COVID-19 were obtained from GeneCards database.The protein-protein interaction network was established using STRING database to analyze the key targets.Gene Oncology(GO)analysis and Kyoto Encyclopedia of Genes and Genomes analysis were also conducted to evaluate the pathways related to the targets of CLD on COVID-19.Moreover,the compound-target-pathway network was established using Cytoscape 3.2.7.Subsequently,the molecular docking method was performed to select the active compounds with high binding affinity on severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and angiotensin-converting enzyme 2(ACE2),which is the key target of SARS-CoV-2 in entering target cells.The possible binding sites were also visualized by a three-dimensional graph.Results:Network pharmacology analysis showed that there were 106 active components and 160 targets of CLD.Additionally,251 targets related to COVID-19 were identified,and 24 candidates of CLD on COVID-19 were selected.A total of 283 GO terms of CLD on COVID-19 were identified,and 181 pathways were screened based on GO and Kyoto Encyclopedia of Genes and Genomes analyses.CLD might alleviate the inflammatory response and improve lung injury to treat COVID-19 through interleukin 17 signaling,T helper cell 17 differentiation,tumor necrosis factor signaling,and hypoxia inducible factor-1 signaling.Besides,molecular docking indicated that beta-sitosterol,kaempferol,and stigmasterol were the top three candidates in CLD with the highest affinity to SARS-CoV-2 and ACE2.Conclusion:Our study identifies the potential mechanisms of CLD on COVID-19 and beta-sitosterol,kaempferol,and stigmasterol may be the key compounds that exert antiviral effects against SARS-CoV-2.

Single-cell analysis of angiotensin-converting enzyme II expression in human kidneys and bladders reveals a potential route of 2019 novel coronavirus infection

Background::Since 2019,a novel coronavirus named 2019 novel coronavirus(2019-nCoV)has emerged worldwide.Apart from fever and respiratory complications,acute kidney injury has been observed in a few patients with coronavirus disease 2019.Furthermore,according to recent findings,the virus has been detected in urine.Angiotensin-converting enzyme II(ACE2)has been proposed to serve as the receptor for the entry of 2019-nCoV,which is the same as that for the severe acute respiratory syndrome.This study aimed to investigate the possible cause of kidney damage and the potential route of 2019-nCoV infection in the urinary system.Methods::We used both published kidney and bladder cell atlas data and new independent kidney single-cell RNA sequencing data generated in-house to evaluate ACE2 gene expression in all cell types in healthy kidneys and bladders.The Pearson correlation coefficients between ACE2 and all other genes were first generated.Then,genes with r values larger than 0.1 and P values smaller than 0.01 were deemed significant co-expression genes with ACE2.Results::Our results showed the enriched expression of ACE2 in all subtypes of proximal tubule(PT)cells of the kidney.ACE2 expression was found in 5.12%,5.80%,and 14.38%of the proximal convoluted tubule cells,PT cells,and proximal straight tubule cells,respectively,in three published kidney cell atlas datasets.In addition,ACE2 expression was also confirmed in 12.05%,6.80%,and 10.20%of cells of the proximal convoluted tubule,PT,and proximal straight tubule,respectively,in our own two healthy kidney samples.For the analysis of public data from three bladder samples,ACE2 expression was low but detectable in bladder epithelial cells.Only 0.25%and 1.28%of intermediate cells and umbrella cells,respectively,had ACE2 expression.Conclusion::This study has provided bioinformatics evidence of the potential route of 2019-nCoV infection in the urinary system.

Angiotensin converting enzymes inhibitors or angiotensin receptor blockers should be continued in COVID-19 patients with hypertension

BACKGROUND Recent studies have revealed that sustained ingestion of angiotensin converting enzymes inhibitors or angiotensin receptor blockers(ACEIs/ARBs)had no harmful effects on coronavirus disease 2019(COVID-19)patients complicated with hypertension.AIM To investigate the impact on COVID-19 patients complicated with hypertension who discontinued using ACEIs/ARBs.METHODS All COVID-19 patients complicated with hypertension admitted to our isolated unit were consecutively recruited in this study.Some patients switched from ACEIs/ARBs to calcium channel blocker(CCBs)after admission,while others continued using non-ACEIs/ARBs.We compared characteristics and clinical outcomes between these two groups of patients.RESULTS A total of 53 patients were enrolled,27 patients switched from ACEIs/ARBs to CCBs while 26 patients continued with non-ACEIs/ARBs.After controlling potential confounding factors using the Cox proportional hazards model,hospital stay was longer in patients who discontinued ACEIs/ARBs,with a hazard ratio of 0.424(95%confidence interval:0.187-0.962;P=0.040),upon discharge than patients using other anti-hypertensive drugs.A sub-group analysis showed that the effect of discontinuing use of ACEIs/ARBs was stronger in moderate cases[hazard ratio=0.224(95%confidence interval:0.005-0.998;P=0.0497)].CONCLUSION Patients in the discontinued ACEIs/ARBs group had longer hospital stays.Our findings suggest that COVID-19 patients complicated with hypertension should continue to use ACEIs/ARBs.