Angiotensin I converting enzyme(ACE)inhibitory activity and antihypertensive effects of rice peptides

In this paper,the antihypertension effect of rice peptide(RP)was studied.With spontaneously hypertensive rats(SHR)and Wistar Kyoto(WKY)as the research objects,RP disposable gastric and long-term gastric irrigation experiments were carried out and systolic blood pressure(SBP)was measured.At the end of the long-term gastric irrigation experiment,the content of nitric oxide(NO),angiotensin-converting enzyme(ACE),angiotensin II(Ang II)and renin in the plasma and the activity of ACE were determined.The results showed that RP could reduce systolic pressure of SHR and had time-dose dependence while high-dose RP signifi cantly reduced systolic pressure by 24.6 and 17.2 mm Hg,respectively after a single and long-term gastric irrigation test.RP also could inhibit the activity of ACE and increase the release of NO.These results suggested that the decompression mechanism of RP is likely to be related to the regulation of the renin-angiotensin system(RAS)and NO.

Correlation of angiotensin converting enzyme gene polymorphism with perioperative myocardial protection under extracorporeal circulation

Objective:To observe the expression of angiotensin converting enzyme(ACE),angiotensinⅡ(AngⅡ),cardiac troponin 【cTnⅠ),creatine kinase isozymes(CK-MB) and muscle red protein(Myo) after cardiopulmonary bypass(CPB),and to investigate the association of polymorphisms in angiotensin converting enzyme genes and myocardial injury.Methods:Sixty-three patients suffered from rheumatic mitral stenosis and scheduled for mitral valve replacement with CPB, were randomly divided into three groups according polymorphisms in angiotensin converting enzyme genes:typeⅡ,type ID,type DD(each=21).Blood samples were withdrawn from artery before operation(T1),at the beginning of CPB(T2),30 min after CPB(T3),(T4) at the end of CPB(T5), 2 h after CPB(T6),6 h after CPB(17) to measure the expression of ACE,AngⅡ,cTnⅠ,CK-MB, Myo.Results:The level of ACE during and after CPB were significantly higher than those before CPB(P【0.05).As extension of CPB time,the expression of ACE was increased.The level of cTnⅠ, CK-MB,Myo after CPB were significantly higher than those before CPB(P【0.05).The level of cTnⅠ,CK-MB and Myo were highest at T7,T6 and T5 and T7,respectively.The level of ACE,AngⅡ,cTnⅠin patients with DD genotype was significantly higher than the ID andⅡgenotype(P【 0.05).Besides,the level of ACE,AngⅡin patients with ID genotype was significantly higher than the II(P【 0.05).Conclusions:There is certain correlation between CPB perioperative midterm ACE and cTnⅠ,Myo,CK-MB.ACE DD genotype is a susceptibility gene of the CPB perioperative myocardial injury.

Study of angiotensin converting enzyme and genotype among Egyptian preeclampsia patients

Preeclampsia is a frequent disorder with reported incidence in pregnancies. In Egypt, it complicates 6%-8% of pregnancies and reaches 15% in referral centers. The renin-angiotensin system activation during the early stages of Preeclampsia proved to be a direct cause. Women carrying the D allele of the ACE-I/D polymorphism have higher measures of uterine artery resistance, which is a marker for development of intrauterine growth retardation and preeclampsia. The maternal syndrome of preeclampsia (PE) during the latter half of pregnancy is believed to result from impaired placentation in early gestation and a failure to develop low resistance uteroplacental circulation. Aim: The aim of this study was to evaluate the association with angiotensin converting enzyme gene polymorphism and changes in its enzyme serum level in preeclamptic patients compared to non preeclamptic control group together with studying the changes in umbilical artery and uterine artery Doppler. Subjects: The study was conducted on 180 pregnant women allocated into two groups having the same inclusion and exclusion criteria except for hypertension and proteinuria;each group comprised of 90 pregnant women with matched age. Methods: Doppler study of umbilical and uterine arteries and the detection of Angiotensin converting gene polymorphism by PCR with Estimation of serum ACE in serum by ELISA technique. Results: The distribution of the ACE-I/D genotypes and allelic frequencies in the present study of polymorphism was 37.8% for the DD, 48.9% for the ID, 13.3% for the II in preeclampsia group while it was 33.3% for the DD, 46.7% for the ID, and 20% for the II in the control group. There was no significant difference between cases and controls regarding the cumulative D effect. Conclusions: No existence of a relation between preeclampsia and ACE gene polymorphism considering different modes of inheritance whether is dominance or recessiveness. No effect of ACE gene polymorphism is on ACE serum level. Positive correlation between ACE gene polymorphism and the uterine artery Doppler changes gives strong evidence that ACE gene may have a role in the histopathological changes taking place in these vessels, therefore affecting maternal prognosis. It is unclear to explain this mismatched ACE genetic influence on the incidence of preeclampsia, but the multifactorial pathogenesis of the development and complication in preeclampsia and also physician’s intervention may contribute to the pregnancy outcome. Recommendations: International collaborations, particularly among countries with a high incidence of preeclampsia, may help to include participants with different cultural and genetic backgrounds, which can provide further insight into the etiology of the disease both genetic and environmental.

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.

SARS coronavirus entry into host cells through a novel clathrin- and caveolae-independent endocytic pathway

While severe acute respiratory syndrome coronavirus （SARS-CoV）~as initially thought to enter cells through direct fusion with the plasma membrane, more recent evidence suggests that yirus entry may also involve endocytosis. We have found that SARS-CoV enters cells viapH- and receptor-dependent endocytosis. Treatment of cells with either SARS-COV spike protein or spike-bearing pseudoviruses resulted in the translocation of angiotensin-converting enzyme 2 （ACE2）, the functional receptor of SARS-CoV, from the cell surface to endosomes. In addition, the spike-bearing pseudoviruses and early endosome antigen 1 were found to colocalize in endosomes. Further analyses using specific endocytic path- way inhibitors and dominant-negative Epsl5 as well as caveolin-1 colocalization study suggested that virus entry was mediated by a clathrin- and caveolae-independent mechanism. Moreover, cholesterol- and sphingolipid-rich lipid raft microdomains in the plasma membrane, which have been shown to act as platforms for many physiological signaling pathways, were shown to be involved in virus entry. Endocytic entry of SARS-CoV may expand the cellular range of SARS-CoV infection, and our findings here contribute to the understanding of SARS-CoV pathogenesis, providing new information for anti-viral drug research.

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.

Identification of therapeutic drugs against COVID-19 through computational investigation on drug repurposing and structural modification

Global prevalence of coronavirus disease 2019(COVID-19)calls for an urgent development of anti-viral regime.Compared with the development of new drugs,drug repurposing can significantly reduce the cost,time,and safety risks.Given the fact that coronavirus harnesses spike protein to invade host cells through angiotensinconverting enzyme 2(ACE2),hence we see if any previous anti-virtual compounds can block spike-ACE2 interaction and inhibit the virus entry.The results of molecular docking and molecular dynamic simulations revealed that remdesivir exhibits better than expected anti-viral invasion potential against COVID-19 among the three types of compounds including remdesivir,tenofovir and lopinavir.In addition,a positive correlation between the surface area occupied by remdesivir and anti-viral invasion potential was also found.As such,the structure of remdesivir was modified by linking an N-benzyl substituted diamidine derivative to its hydroxyl group through an ester bond.It was found that this compound has a higher anti-viral invasion potential and greater specificity.

Inhibitory mechanism of angiotensin-converting enzyme inhibitory peptides from black tea

The aim of this work is to discover the inhibitory mechanism of tea peptides and to analyse the affinities between the peptides and the angiotensin-converting enzyme(ACE)as well as the stability of the complexes using in vitro and in silico methods.Four peptide sequences identified from tea,namely peptides I,II,III,and IV,were used to examine ACE inhibition and kinetics.The half maximal inhibitory concentration(IC_(50))values of the four peptides were(210.03±18.29),(178.91±5.18),(196.31±2.87),and(121.11±3.38)μmol/L,respectively.The results of Lineweaver-Burk plots showed that peptides I,II,and IV inhibited ACE activity in an uncompetitive manner,which requires the presence of substrate.Peptide III inhibited ACE in a noncompetitive manner,for which the presence of substrate is not necessary.The docking simulations showed that the four peptides did not bind to the active sites of ACE,indicating that the four peptides are allosteric inhibitors.The binding free energies calculated from molecular dynamic(MD)simulation were-72.47,-42.20,-52.10,and-67.14 kcal/mol(1 kcal=4.186 kJ),r espectively.The lower IC_(50)value of peptide IV may be attributed to its stability when docking with ACE and changes in the flexibility and unfolding of ACE.These four bioactive peptides with ACE inhibitory ability can be incorporated into novel functional ingredients of black tea.

The Study of Molecular Mechanisms of Xuanbai Chengqi Decoction(宣白承气汤)in the Treatment of Coronavirus Disease 2019 Based on Network Pharmacology and Molecular Docking Method

Objective:To explore the molecular mechanism of Xuanbai Chengqi Decoction(宣白承气汤)in the treatment of Coronavirus Disease 2019(COVID-19)based on network pharmacology,and to verify by molecular docking technology.Methods:The components and targets of Xuanbai Chengqi Decoction(宣白承气汤)were obtained by TCMSP,targets’information was corrected based on the databases such as UniP rot and DrugBank,and the software Cytoscape3.7.1 was adopted to construct TCM-Component-Target and Component-Target network.The main targets were mapped to the KEGG pathway and the GO biological process with the help of DAVID to further elucidate the potential relationship between the main targets and Xuanbai Chengqi Decoction(宣白承气汤)therapy for COVID-19.In the end,the Swiss Dock platform was adopted for the molecular docking verification of key components and targets.Results:The Component-Target network consists of 35 components and 106 corresponding targets,the main targets include COX-2,NCOA2,PTGS1,HSP90 AB1,PRKACA and PGR,etc.There are 561 GO entries of target mapping(P 0.05),including 155 entries for Biological Processes(BP),147 entries for Cell Composition(CC),and 259 entries for Molecular Function(MF).There are 38 KEGG mapping pathways(P 0.05),including many aspects of infectious disease,immune system and endocrine system,as well as Calcium signaling pathway,VEGF signaling pathway,PI3K-Akt signaling pathway and other processes.Conclusion:The result of molecular docking shows that the affinity of the key components such as beta-sitosterol and stigmasterol are similar to recommended medications for COVID-19.Its effect in the treatment of middle stage of COVID-19 may be related to the blocking of the binding of COVID-19 virus and ACE2,antivirus,and relieving inflammatory storm.

Cytoplasmic domain and enzymatic activity of ACE2 are not required for PI4KB dependent endocytosis entry of SARS-CoV-2 into host cells

The recent COVID-19 pandemic poses a global health emergency.Cellular entry of the causative agent SARS-CoV-2 is mediated by its spike protein interacting with cellular receptor-human angiotensin converting enzyme 2(ACE2).Here,by using lentivirus based pseudotypes bearing spike protein,we demonstrated that entry of SARS-CoV-2 into host cells was dependent on clathrin-mediated endocytosis,and phosphoinositides played essential roles during this process.In addition,we showed that the intracellular domain and the catalytic activity of ACE2 were not required for efficient virus entry.Finally,we showed that the current predominant Delta variant,although with high infectivity and high syncytium formation,also entered cells through clathrin-mediated endocytosis.These results provide new insights into SARS-CoV-2 cellular entry and present proof of principle that targeting viral entry could be an effective way to treat different variant infections.

Angiotensin Converting Enzyme as a Possible Biomarker to Predict Effect of Obstetric Anesthesia on Pregnant Women with COVID-19 Infection

We retrospectively investigated 68 parturients with or without COVID-19 undergone emergency cesarean section with combined spinal-epidural anesthesia(CSEA)from a single tertiary university hospital in Wuhan,China.The cases were divided into 2 groups:patients with COVID-19 pneumonia(Group 1)and cases without COVID-19 pneumonia(Group 2).The patients in Group 1 were later divided into 2 groups:patients with low-angiotensin converting enzyme(ACE)(Group 3)and patients with normal-ACE(Group 4).The ACE levels,blood pressure and anesthesia management between the patients of Group 1 and Group 2,Group 3 and Group 4 were recorded as the primary outcome.The secondary outcome included perioperative symptoms,laboratory parameters and vital signs.Compared with Group 2,the patients in Group 1 had different ACE level and lower blood pressure after CSEA.Compared with Group 4,the patients in Group 3 showed lower SBP after CSEA(127 vs.130 mm Hg,p=0.028),accompanied with more partus matures and younger age(28 vs.32 years,p=0.007).ACE may be a possible biomarker to predict the anesthesia effects on patients with COVID-19 infections undergoing emergency cesarean delivery.

CHRONIC EFFECTS OF EARLY ANGIOTENSIN-CONVERTING ENZYME INHIBITOR (QUINAPRIL) OR ANGIOTENSIN II RECEPTOR BLOCKADE (LOSARTAN) ON HEMODYNAMICS AND REMODELING IN RATS AFTER EXPERIMENTAL MYOCARDIAL INFARCTION

The long-term effects of an angiotensin-converting enzyme (ACE) inhibitor on hemodynamics and remodeling

Cardiomyopathy protection in Chagas Disease

There is some published evidence suggesting micro vascular endothelial dysfunction and dysautonomia involvement in Chagas disease in association with cardiomyocyte changes favoring disease progression. The combined treatment between angiotensin converting enzyme (ACE) inhibitor drugs;Simvastatin, muscarinic antibody immunoadsorbent together with fungicidal drugs would open therapeutic possibilities in this disease.

Al-Akidi Therapeutic Protocol for Severe Infections Associated with Covid-19:Potential and Effective Treatment by Levofloxacin and Vitamin D3 and Zinc(Part 1)

Background:The emergence of Coronavirus SARS-CoV-2 evoked an unprecedented threat globally.Ever since the spread of this pandemic research and clinical trials have concentrated on the repurposing of already exciting FDA drugs to find a successful candidate to combat Covid-19.Objective:The objective of this study is to propose a therapeutic protocol that may have a potential solution to treat the severe infections associated with coronavirus.The clinical application of this protocol(Al-Akidi Therapeutic Protocol,A-TP)is highly recommended,as there are several scientific evidences that support this trusted protocol to be of great potential.Methods and Materials:This A-TP includes the use of one of the respiratory Fluoroquinolones(Levofloxacin or Moxifloxacin)in doses of 500 mg twice daily for 7-10 days,together with high doses of Vitamin D3(10000 IU/day)and Zinc(50 mg daily)for few weeks.This protocol is based on the previous antiviral activity of those Fluoroquinolones towards few viruses,the potent antibacterial activity on respiratory infections and high available concentrations in the lungs.It is also based on molecular docking of Levofloxacin and Moxifloxacin on various viral enzymes.Results:Molecular docking showed encouraging and very interesting docking scores and binding affinity of Levofloxacin and Moxifloxacin to certain viral enzymes,such as,RNA dependent RNA polymerase(RdRp),3-Cysteine-Like protease,Neuraminidase,Replicase polyproteins and Trans-Membrane Protease Serine 2 inhibitor(TMPRSS2).The highly expected clinical results of using this protocol are:reduce infection,control of temperature,improve breathing with less dependent on supplemented oxygen,and remarkable reduction of the pro-inflammatory cytokine storm,and hence,reduce hospitalization and mortality.Conclusion:Levofloxacin is highly recommended in managing the severe infections associated with Corona virus and has a remarkable reduction of pro-inflammatory cytokine storm as an immuomodulating agent.Levofloxacin is superior in this protocol over Moxifloxacin,due to its high excretion(≤83%)as unchanged through the kidneys,while Moxifloxacin is only 20%is excreted unchanged.It is an extra advantage of Levofloxacin to manage coronavirus in the kidneys.High doses of Vitamin D3 and Zinc are very useful to provide additional effective measures to combat Corona virus.Therefore,the use of this A-TP is highly and strongly recommended,as it serves the full requirements for excellent and potential therapy for the severe infections associated with Covid-19.

Interferon Regulatory Factor 5 and Renin-Angiotensin-Aldosterone System Polymorphisms in Coronary Artery Disease: An Overview of Experimental and Clinical Studies

Heart diseases are the main cause of mortality in Mexico, being coronary heart disease the most frequent in the country. Its high prevalence makes important the study of the pathophysiology and the search for prognostic factors. Different genes and polymorphisms promote atherogenesis and coronary artery disease, they affect inflammatory and vascular pathological processes. Interferon regulatory factor 5 (IRF5) is associated with coronary heart disease, it promotes chronic inflammation and cytokines release;it could trigger immune reactions and its activating receptors express in the vascular endothelium. Besides, polymorphisms in the renin-angiotensin-aldosterone system (RAAS) are implied with coronary disease, they are found in angiotensinogen (AGT), angiotensin II type 1 receptor (AT1R), angiotensin II type 2 receptor (AT2R), and angiotensin-converting enzyme (ACE) genes. These genetic polymorphisms are associated with a prothrombotic state, endothelial dysfunction, and immune activation. Multiple experimental studies showed that chronic activation of RAAS and chronic expression of IRF5 generates an environment prone to the development of atherosclerosis, and autoimmune and cardiovascular diseases. Studying these specific genes and their relationship with coronary heart disease will allow a better understanding of the pathological process and possibly the quest for new treatments.

Screening, ACE-inhibitory mechanism and structure-activity relationship of a novel ACE-inhibitory peptide from Lepidium meyenii (Maca) protein hydrolysate

Maca is an edible functional plant with antihypertensive activity.However,there is still no clear understanding of angiotensin-converting enzyme(ACE)inhibitory substances in maca.In the present study,six novel angiotensin-converting enzyme inhibitor(ACEI)peptides(RSRGVFF,LGHPVFRNK,HGSCNYR,KANLGFRF,GGGHKRLY and SSYLGRN)were found in maca protein hydrolysates using in silico tools and molecular docking.RSRGVFF revealed prominent ACE inhibitory activity with an IC_(50) value of 5.01μM as a mixed-type ACE inhibitor.An analysis of the structure-activity connection demonstrated that the arginine at N-terminal is the most likely active residue in RSRGVFF,and two phenylalanines at the C-terminal also contributed to its inhibitory activity.Thus,these results indicate that maca protein may be one of the substances that leads to antihypertensive activity.This provides a new perspective to understanding the ACE inhibitory activity of maca and offers valuable insights to enlighten the structure-activity relationship of ACEI peptides.

Antibody Cocktail Exhibits Broad Neutralization Activity Against SARS-CoV-2 and SARS-CoV-2 Variants

Severe acute respiratory syndrome coronavirus 2(SARS-Co V-2)has precipitated multiple variants resistant to therapeutic antibodies.In this study,12 high-affinity antibodies were generated from convalescent donors in early outbreaks using immune antibody phage display libraries.Of them,two RBD-binding antibodies(F61 and H121)showed high-affinity neutralization against SARS-Co V-2,whereas three S2-target antibodies failed to neutralize SARS-Co V-2.Following structure analysis,F61 identified a linear epitope located in residues G446–S494,which overlapped with angiotensinconverting enzyme 2(ACE2)binding sites,while H121 recognized a conformational epitope located on the side face of RBD,outside from ACE2 binding domain.Hence the cocktail of the two antibodies achieved better performance of neutralization to SARS-Co V-2.Importantly,these two antibodies also showed efficient neutralizing activities to the variants including B.1.1.7 and B.1.351,and reacted with mutations of N501 Y,E484 K,and L452 R,indicated that it may also neutralize the recent India endemic strain B.1.617.The unchanged binding activity of F61 and H121 to RBD with multiple mutations revealed a broad neutralizing activity against variants,which mitigated the risk of viral escape.Our findings revealed the therapeutic basis of cocktail antibodies against constantly emerging SARS-Co V-2 variants and provided promising candidate antibodies to clinical treatment of COVID-19 patients infected with broad SARS-Co V-2 variants.

Long Term Culture of Human Kidney Proximal Tubule Epithelial Cells Maintains Lineage Functions and Serves as an Ex vivo Model for Coronavirus Associated Kidney Injury

The mechanism of how SARS-CoV-2 causes severe multi-organ failure is largely unknown. Acute kidney injury(AKI) is one of the frequent organ damage in severe COVID-19 patients. Previous studies have shown that human renal tubule cells could be the potential host cells targeted by SARS-CoV-2. Traditional cancer cell lines or immortalized cell lines are genetically and phenotypically different from host cells. Animal models are widely used, but often fail to reflect a physiological and pathogenic status because of species tropisms. There is an unmet need for normal human epithelial cells for disease modeling. In this study, we successfully established long term cultures of normal human kidney proximal tubule epithelial cells(KPTECs) in 2 D and 3 D culture systems using conditional reprogramming(CR) and organoids techniques.These cells had the ability to differentiate and repair DNA damage, and showed no transforming property. Importantly, the CR KPTECs maintained lineage function with expression of specific transporters(SLC34 A3 and cubilin). They also expressed angiotensin-converting enzyme 2(ACE2), a receptor for SARS-CoV and SARS-CoV-2. In contrast, cancer cell line did not express endogenous SLC34 A3, cubilin and ACE2. Very interestingly, ACE2 expression was around twofold higher in 3 D organoids culture compared to that in 2 D CR culture condition. Pseudovirion assays demonstrated that SARS-CoV spike(S) protein was able to enter CR cells with luciferase reporter. This integrated 2 D CR and 3 D organoid cultures provide a physiological ex vivo model to study kidney functions, innate immune response of kidney cells to viruses, and a novel platform for drug discovery and safety evaluation.

Macrophage exosomes transfer angiotensin Ⅱ type 1 receptor to lung fibroblasts mediating bleomycin-induced pulmonary fibrosis

Background:Macrophages are involved in the pathogenesis of idiopathic pulmonary fibrosis,partially by activating lung fibroblasts.However,how macrophages communicate with lung fibroblasts is largely unexplored.Exosomes can mediate intercellular communication,whereas its role in lung fibrogenesis is unclear.Here we aim to investigate whether exosomes can mediate the crosstalk between macrophages and lung fibroblasts and subsequently induce fibrosis.Methods:In vivo,bleomycin(BLM)-induced lung fibrosis model was established and macrophages infiltration was examined.The effects of GW4869,an exosomes inhibitor,on lung fibrosis were assessed.Moreover,macrophage exosomes were injected into mice to observe its pro-fibrotic effects.In vitro,exosomes derived from angiotensin Ⅱ(Ang Ⅱ)-stimulated macrophages were collected.Then,lung fibroblasts were treated with the exosomes.Twenty-four hours later,protein levels ofα-collagen I,angiotensin Ⅱ type 1 receptor(AT1R),transforming growth factor-β(TGF-β),and phospho-Smad2/3(p-Smad2/3)in lung fibroblasts were examined.The Student's t test or analysis of variance were used for statistical analysis.Results:In vivo,BLM-treated mice showed enhanced infiltration of macrophages,increased fibrotic alterations,and higher levels of Ang Ⅱ and AT1R.GW4869 attenuated BLM-induced pulmonary fibrosis.Mice with exosomes injection showed fibrotic features with higher levels of Ang Ⅱ and AT1R,which was reversed by irbesartan.In vitro,we found that macrophages secreted a great number of exosomes.The exosomes were taken by fibroblasts and resulted in higher levels of AT1R(0.22±0.02 vs.0.07±0.02,t=8.66,P=0.001),TGF-β(0.54±0.05 vs.0.09±0.06,t=10.00,P<0.001),p-Smad2/3(0.58±0.06 vs.0.07±0.03,t=12.86,P<0.001)andα-collagen I(0.27±0.02 vs.0.16±0.01,t=7.01,P=0.002),and increased Ang Ⅱ secretion(62.27±7.32 vs.9.56±1.68,t=12.16,P<0.001).Interestingly,Ang Ⅱ increased the number of macrophage exosomes,and the protein levels of Alix(1.45±0.15 vs.1.00±0.10,t=4.32,P=0.012),AT1R(4.05±0.64 vs.1.00±0.09,t=8.17,P=0.001),and glyceraldehyde-3-phosphate dehydrogenase(2.13±0.36 vs.1.00±0.10,t=5.28,P=0.006)were increased in exosomes secreted by the same number of macrophages,indicating a positive loop between Ang Ⅱ and exosomes production.Conclusions:Exosomes mediate intercellular communication between macrophages and fibroblasts plays an important role in BLM-induced pulmonary fibrosis.

Effects of angiotensin Ⅱ receptor blocker usage on viral load,antibody dynamics, and transcriptional characteristics among COVID-19 patients with hypertension

Epidemiological evidence suggests that patients with hypertension infected with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)are at increased risk of acute lung injury.However,it is still not clear whether this increased risk is related to the usage of renin-angiotensin system(RAS)blockers.We collected medical records of coronavirus disease 2019(COVID-19)patients from the First Affiliated Hospital,Zhejiang University School of Medicine(Hangzhou,China),and evaluated the potential impact of an angiotensin II receptor blocker(ARB)on the clinical outcomes of COVID-19 patients with hypertension.A total of 30 hypertensive COVID-19 patients were enrolled,of which 17 were classified as non-ARB group and the remaining 13 as ARB group based on the antihypertensive therapies they received.Compared with the non-ARB group,patients in the ARB group had a lower proportion of severe cases and intensive care unit(ICU)admission as well as shortened length of hospital stay,and manifested favorable results in most of the laboratory testing.Viral loads in the ARB group were lower than those in the non-ARB group throughout the disease course.No significant difference in the time of seroconversion or antibody levels was observed between the two groups.The median levels of soluble angiotensin-converting enzyme 2(sACE2)in serum and urine samples were similar in both groups,and there were no significant correlations between serum sACE2 and biomarkers of disease severity.Transcriptional analysis showed 125 differentially expressed genes which mainly were enriched in oxygen transport,bicarbonate transport,and blood coagulation.Our results suggest that ARB usage is not associated with aggravation of COVID-19.These findings support the maintenance of ARB treatment in hypertensive patients diagnosed with COVID-19.