Association Between PDGFs MRNA Expression In Peripheral Blood Platelets And Acute Myocardial Infarction: A Case-control Study

Backgrounds and objectivesAcute myocardial infarction（AMI）,a severe type of coronary heart disease,is a major cause of death and disability.The formation of atherosclerotic（AS）plaques typically takes a long time,starting with thickening of the intima,cholesterol deposition,and formation of lipid streaks,gradually leading to unstable plaques.The rupture of unstable plaques leads to platelet aggregation and activation,forming acute intravascular thrombi,which is the main pathological mechanism of AMI.Platelet-derived growth factors（PDGFs）are mainly secreted by epithelial cells,endothelial cells,macrophages,and are stored in platelets,and released upon degranulation,promoting and aggravating AS.Messenger RNA（m RNA）molecules can encode proteins through the translation function of ribosomes,and changes in m RNA expression levels in different cell types are associated with certain diseases.Therefore,m RNA has become a valuable biomarker for various disease diagnoses.Seeking molecular biomarkers of susceptibility to disease at the RNA level can provide a scientific basis for early prediction and intervention of AMI.MethodsIn this case-control study,144 patients diagnosed with acute myocardial infarction（AMI）who were admitted to Yixing Hospital Affiliated to Jiangsu University from November 2018 to January 2021 were selected as the case group.Additionally,65healthy controls matched for age and gender were selected from the same geographic area,with exclusion of patients with coronary heart disease（CHD）.All participants had no tumors or severe liver or renal dysfunction.Clinical data and biochemical results of patients were recorded in detail,and peripheral blood platelet samples were taken before anticoagulant drug use upon admission for both control and AMI groups,and RNA was extracted and the m RNA expression levels of platelet-derived growth factors（PDGFA,PDGFB,PDGFC,and PDGFD）were measured.The relative gene expression level was calculated using theΔCT method,and the outlier values were corrected by mean±3×standard deviation before calculation.The independent samples Mann-Whitney U test was used to compare the relative m RNA expression levels(2^-ΔΔCT)between the case and control groups;propensity score analysis was conducted to evaluate the robustness of the results.Stratified analysis was performed by subgroups based on age（<65 years and≥65 years）,gender,smoking,drinking,hypertension,diabetes,and dyslipidemia,and the differences in PDGFs m RNA expression levels between the case and control groups in different subgroups were compared using the Mann-Whitney U test.Generalized linear models were used to compare the heterogeneity between subgroups.Restricted cubic spline regression（RCS）was used to explore the dose-response relationship between gene expression levels and the risk of AMI.Based on the RCS analysis results,the gene expression levels were further divided into four groups based on quartiles（P25,P50,P75）,and logistic regression models were used to adjust for age,gender,smoking,drinking,hypertension,diabetes,and dyslipidemia to explore the impact of different gene expression levels on the risk of AMI.Spearman rank correlation was used to analyze the correlation between gene expression levels and blood pressure,blood glucose,blood lipid levels,and platelet parameters.Results1.There were no significant differences in levels of dyslipidemia,blood glucose（GLU）,triglycerides（TG）,mean platelet volume（MPV）,and platelet distribution width（PDW）between the case and control groups（P>0.05）.The case group had a higher mean age and incidence rates of hypertension and diabetes compared to the control group（P<0.05）,while the proportion of males,smoking rate,alcohol consumption rate,systolic blood pressure,diastolic blood pressure,total cholesterol（TC）,high-density lipoprotein cholesterol（HDL-C）,low-density lipoprotein cholesterol（LDL-C）,platelet count（PLT）,and plateletcrit（PCT）were lower in the case group than in the control group（P<0.05）.2.Using the Mann-Whitney U test,our analysis revealed that there were no significant differences in the expression levels of PDGFA,PDGFB,and PDGFC between the control and case groups（P>0.05）.However,for PDGFD,the expression level in the case group was significantly higher than that in the control group（P=0.038）,with a fold change of 4.705.3.Sensitivity analysis was conducted using propensity score matching to match75 cases and 53 controls.The histogram of propensity score distribution indicated improved balance between the two groups.Sensitivity analysis of the matched data showed that there was a significant difference in PDGFD m RNA expression between the case and control groups,with the case group exhibiting a 7.371-fold increase in expression compared to the control group（P<0.05）.This result was consistent with our initial findings and suggests that our analysis is robust.4.Stratified analysis showed that in different age groups,PDGFD expression levels were significantly different between cases and controls in the group aged 65 years and older（P=0.044）,with high expression levels in cases and a fold difference of 8.312compared to controls.In different gender groups,PDGFA and PDGFD expression levels were statistically significant between female cases and controls（P<0.05）,with higher expression levels in cases than controls,and PDGFA showed heterogeneity in the differences between case and control groups in different gender groups(P_{heterogeneity}=0.038).Stratified analysis of different smoking behaviors showed that the expression levels of PDGFA,PDGFC,and PDGFD were statistically significant between non-smokers in cases and controls（P<0.05）,with higher expression levels in cases than controls,and PDGFC and PDGFD showed heterogeneity in the differences between case and control groups in different smoking behaviors(P_{heterogeneity}<0.05).In different alcohol consumption groups,PDGFD expression levels were statistically significant between non-drinkers in cases and controls（P=0.009）,with higher expression levels in cases than controls.Stratification results of hypertension showed that PDGFD expression levels were statistically significant between normal blood pressure groups in cases and controls（P=0.017）,with higher expression levels in cases than controls,while PDGFA showed heterogeneity in the differences between case and control groups in different hypertension groups(P_{heterogeneity}=0.039).In subgroups with different diabetes conditions,there was no significant difference in PDGFs m RNA expression levels between cases and controls（P>0.05）.In subgroups with different blood lipid abnormality conditions,PDGFA expression levels were statistically significant between cases and controls in the blood lipid abnormality group（P=0.049）,with higher expression levels in cases than controls,while for PDGFD,its expression levels were statistically significant between cases and controls in the normal blood lipid group（P=0.034）,with higher expression levels in cases than controls.5.The RCS analysis of gene expression levels revealed a significant nonlinear association between PDGFs expression and AMI(P_non-linear<0.05).The risk of AMI was highest when PDGFs expression was around 1,and it gradually decreased as the expression level increased or decreased.For PDGFA,the risk of AMI increased first and then decreased with increasing expression levels,and the risk leveled off when the expression level exceeded 5.For PDGFB,PDGFC,and PDGFD,the risk of AMI increased first and then decreased with increasing expression levels,and the risk slightly increased or leveled off when the expression level reached a higher level.6.After grouping gene expression by quartiles into logistic regression models and adjusting for relevant covariates,the results showed that there was no statistically significant increase in the risk of AMI in the PDGFA gene groups Q2,Q3 and Q4compared to the low expression Q1 group（P>0.05）;PDGFB expression levels in the second quartile range（Q3）were associated with an increased risk of AMI compared to the low expression Q1 group with an OR（95%CI）of 4.340（1.344-14.018）.PDGFB expression level in the second quartile range（Q3）was associated with an increased risk of AMI compared to the low expression Q1 group with an OR（95%CI）of 4.340（1.344-14.018）,while the Q2 and Q4 groups were not statistically associated with an increased risk of AMI with an OR（95%CI）of 2.906（0.974-8.667）and 1.684（0.620-4.575）,respectively;PDGFC was associated with an increased risk in the Q3 group compared to the low expression Q1 group with an OR（95%CI）of increased risk in the Q2 and Q4 groups compared to the low expression Q1 group,with an OR（95%CI）of4.097（1.324-12.677）and a non-statistically significant increased risk in the Q2 and Q4groups,with ORs（95%CI）of 2.554（0.910-7.166）and 2.726（0.893-8.326）,respectively;PDGFD compared to the low expression Q1 group,with an increased risk in the Q2 and Q3 groups,with OR（95%CI）was 11.539（3.238-41.123）and 10.571（3.076-36.328）,respectively,and the increased risk in the Q4 group was not statistically significant,with an OR（95%CI）of 2.614（0.889-7.683）.7.Correlation analysis showed that PDGFA showed a weak negative correlation with TC in the total population（r=-0.12,P<0.05）and no correlation with SBP,DBP,GLU,TG,HDL-C,LDL-C,PLT,MPV,PCT,and PDW（P>0.05）;PDGFB,PDGFC,and PDGFD showed no correlation with SBP,DBP,GLU,TC,TG,HDL-C,LDL-C,PLT,MPV,PCT,and PDW were not correlated（P>0.05）.In both case and control populations,PDGFs did not correlate with SBP,DBP,GLU,TC,TG,HDL-C,LDL-C,PLT,MPV,PCT,and PDW（P>0.05）.ConclusionsThe m RNA expression of PDGFs in peripheral blood platelets showed a non-linear dose-response relationship with the risk of AMI,where the medium expression levels of PDGFB,PDGFC,and PDGFD genes were associated with an increased risk of AMI.