Study On The Changes Of Peripheral Blood Immune Cells In The Heart And Spleen And The Role Of LncRNA Sros1 In The Occurrence And Development Of Heart Failur

Background:Heart failure(HF)is a severe or advanced form of heart disease.In recent years,more and more studies have shown that the immune system[including immune cells,immune factors(such as cytokines)and immune organs]plays an important role in the occurrence and development of HF.The imbalance can accelerate the progress of HF and produce adverse prognosis.Produced in various immune organs(such as bone marrow and spleen),immune cells and their secreted immune factors can be transported to the heart through peripheral blood and affect cardiovascular homeostasis.It is found that the heart and spleen can interact or "talk"with each other,called "cardiosplenic axis",which takes part in the pathophysiology of ischemic HF.However,the mechanism has not been clarified.How immune cells and their immunoreactive substances of immune organs affect the occurrence and development of HF caused by different aetiologies and make different prognosis remains to be explored.Long chain noncoding RNA(lncRNAs)Srosl(Srosl)is a newly discovered microRNA-1 targeted lncRNA.The induced degradation or deletion of Sros1 can promote promoted macrophages interferon(IFN)-γ/STAT1 signaling pathway,that enhanced marcophages to clear Listeria monocytogenes.Previous studies found that there was an increase in cardiac fibrosis in Sros1 gene deleted mice(Sros1-/-).Therefore,we studied the expression and possible mechanism of immune cells and lncRNA Sros1 in the developmenet of HF.Objective:(1)To investigate the expression,changes and the influenced factors of the count and ratio of peripheral blood total leukocytes and their subtypes in CHF patients.(2)To explore whether there were any changes in immune cells among different types of HF mouse models after 28-day surgery.(3)To explore whether Sros1 plays a role in the occurrence and development of cardiac fibrosis and HF.Method:(1)Used the public database[National Health and Nutrition Survey(NHANES)]to apply the outpatient follow-up data of community patients with CHF.(2)Used mass cytometry(CyTOF)and flow cytometry(FACS)to detect immune cell changes[neutrophils,macrophages,natural killer(NK)cells,dendritic cells(DCs),CD4+T cells,CD8+T cells,Treg cells and B cells]in hearts,spleens and peripheral blood in a myocardial infarction-induced HF mouse model(MI group),transverse aortic constriction-induced HF mouse model(TAC group),and chronic isoproterenol infusion-induced HF mouse model(ISO group).(3)Compared the expression levels of RNA and protein related to myocardial fibrosis in Sros1-/-and wild-type(WT)mice;Observed the changes of Srosl and expression related molecules of myocardial fibrosis in myocardium as well as cardiac function of both chronic isoproterenol infusion-induced HF(ISO-HF)and Srosl gene deleted mice.Results:(1)Immune imbalance existed in CHF patients,characterized by increased counts of total leukocytes,granulocytes and monocytes in peripheral blood,decreased lymphocyte count and significantly increased neutrophil to lymphocyte ratio(NLR).At the same time,patients with CHF showed higher BMI,lower energy and macronutrient intake,cholesterol and water intake,lower physical activity level,longer rest time and hemodilution(decreased hematocrit and hemoglobin).Secondly,except that the level of neutrophils in peripheral blood increased slightly,there was no difference in the counts of total leukocytes and other subtypes and NLR ratio between CHF patients with obese and non-obese CHF patients.Finally,the increase of energy intake could increase the number of total leukocytes,neutrophils and monocytes in peripheral blood of CHF patients,while the elevation of exercise reduced NLR in patients with CHF.The rest time did not affect the count and ratio of total leukocytes and their subtypes in peripheral blood of patients with CHF.(2)At 28 days after surgery,the adapted immune cells,mainly CD4+T cells and their subtypes,changed in the failing myocardium in all three types of HF groups.In MI group,CD4+T cells in myocardium increased,mainly CD3+CD4+CD69+MHCI+T cells and B cells.In ISO group,CD4+T cells increased,mainly CD4+CD44+CD161+T cells,while CD4+CD69+CD117+IL-17A+T cells(Th17 cells)decreased.The total number of CD4+T cells in the heart of TAC group did not change significantly.The subtypes,CD4+IL10+T cells elevated,while CD4+CD44+CD161+ T cells and CD4+CD25+CD44+CD161+Foxp3+T cells(Treg cells)dimished.DCs and CD8+T cells in the spleen changed only in the ISO group.Significant changes in the NK cells or DCs in PBMCs were only observed in the TAC or ISO groups.(3)Both of Sirius red,and Masson staining,as well as the expression of genes of transforming growth factor(TGF)-β/SMAD signaling pathway showed increased cardiac fibrosis in Sros1-/-mice.Srosl significantly decreased in the heart in ISO-HF mice at 28 days after operation.Compared with the ISO-HF model,the myocardial fibrosis of Sros1-/-ISO-HF model was significantly increased,and genes of TGF-β/SMAD signaling pathway also elevated importantly,but there was no significant difference in the decline of cardiac systolic function between two groups.Conclusion:(1)There is immune imbalance in CHF patients,which is characterized by the increase of peripheral blood total leukocyte,granulocytes,monocyte count and NLR,as well as the decrease of lymphocyte count.Obesity and lifestyle have certain effects on the total number and subtypes of peripheral blood leukocytes in patients with CHF.Obesity has little effect on the total number,subtypes and NLR in patients with CHF,while the increase of energy intake can increase the number of total leukocytes,neutrophils and monocytes in patients with CHF.Also,physical activities reduced NLR in CHF patients.(2)Adaptive immune cells(mainly different subtypes of CD4+T cells)changed in the myocardium in each HF mouse model aferr 28-day surgery.(3)Cardiac fibrosis were increased in Sros1-/-mice,and Srosl decreased significantly in the ISO-HF mice after 28-day surgery.The elevation of cardiac fibrosis in Sros1-/-ISO-HF mice was more obvious,suggesting that Sros1 can play a role in the occurrence and development of cardiac fibrosis.It may be through regulating TGF-β/SMAD2/3 signaling pathway.