This study explored the effect of the Mycobacterium tuberculosis(Mtb)PE/PPE family protein PE_PGRS37 on the growth of Mycobacterium smegmatis(Ms)and macrophage autophagy during Mtb infection.The pe_pgrs37 gene was amplified from Mtb genome through PCR,and the recombinant vector pAIN-PE_PGRS37 was successfully constructed through homologous recombi-nation.pAIN-PE_PGRS37 and pAIN were integrated into Ms through electroshock to construct pAIN-PGRS37/Ms and pAIN/Ms re-combinant bacteria.Western blotting indicated that the PE_PGRS37 protein was correctly expressed in pAIN-PE_PGRS37/Ms.The re-combinant bacteria were inoculated in 7H9/7H10 medium,and their colony morphology and growth curves were observed.No signifi-cant difference in colony morphology was observed between pAIN-PE_PGRS37/Ms and pAIN/Ms.The growth rate significantly in-creased between 10 and 16 h,and a plateau was reached at 26 h.After infection of U937 cells with pAIN-PE_PGRS37/Ms and pAIN/Ms,macrophage autophagy flow was detected with western blotting and immunofluorescence.In the pAIN-PE_PGRS37/Ms-infected group,compared with the pAIN/Ms-infected group,macrophage LC3-II and p62 protein expression was significantly up-regulated(P<0.001)and inhibited autophagosome and lysosome fusion.The intracellular survival of the recombinant bacteria was detected through colony counting,and pAIN-PE_PGRS37/Ms showed significantly greater survival in macrophages at 12 h,24 h,and 48 h than pAIN/Ms(P<0.05).Our results suggested that PE_PGRS37 protein promotes Mycobacterium survival in macrophages by blocking macro-phage autophagy flow,thus inhibiting macrophage autophagy.

This study explored the effect of the Mycobacterium tuberculosis(Mtb)PE/PPE family protein PE_PGRS37 on the growth of Mycobacterium smegmatis(Ms)and macrophage autophagy during Mtb infection.The pe_pgrs37 gene was amplified from Mtb genome through PCR,and the recombinant vector pAIN-PE_PGRS37 was successfully constructed through homologous recombi-nation.pAIN-PE_PGRS37 and pAIN were integrated into Ms through electroshock to construct pAIN-PGRS37/Ms and pAIN/Ms re-combinant bacteria.Western blotting indicated that the PE_PGRS37 protein was correctly expressed in pAIN-PE_PGRS37/Ms.The re-combinant bacteria were inoculated in 7H9/7H10 medium,and their colony morphology and growth curves were observed.No signifi-cant difference in colony morphology was observed between pAIN-PE_PGRS37/Ms and pAIN/Ms.The growth rate significantly in-creased between 10 and 16 h,and a plateau was reached at 26 h.After infection of U937 cells with pAIN-PE_PGRS37/Ms and pAIN/Ms,macrophage autophagy flow was detected with western blotting and immunofluorescence.In the pAIN-PE_PGRS37/Ms-infected group,compared with the pAIN/Ms-infected group,macrophage LC3-II and p62 protein expression was significantly up-regulated(P<0.001)and inhibited autophagosome and lysosome fusion.The intracellular survival of the recombinant bacteria was detected through colony counting,and pAIN-PE_PGRS37/Ms showed significantly greater survival in macrophages at 12 h,24 h,and 48 h than pAIN/Ms(P<0.05).Our results suggested that PE_PGRS37 protein promotes Mycobacterium survival in macrophages by blocking macro-phage autophagy flow,thus inhibiting macrophage autophagy.

Objective To establish an appropriate diabetic retinopathy (DR) risk assessment model for patients with type 2 diabetes mellitus (T2DM).Methods A retrospective clinical analysis.From January 2016 to December 2017,753 T2DM patients in the Third Affiliated Hospital of Southern Medical University were analyzed retrospectively.Digital fundus photography was taken in all patients.Fasting plasma glucose (FPG),HbA1c,total bilirubin (TB),blood platelet,total cholesterol (TC),triglyceride (TG),high density lipoprotein cholesterol (HDL-c),low density lipoprotein cholesterol (LDL-c),apolipoprotein-A (apoA),apolipoprotein-B (apoB),serum creatinine,blood urea nitrogen (BUN),blood uric acid,fibrinogen (Fg),estimated glomerular filtration (eGFR) were collected.The patients were randomly assigned to model group and testify group,each had 702 patients and 51 patients respectively.Logistic regression was used to screen risk factors of DR and develop an assessment scale that can be used to predict DR.Goodness of fit was examined using the Hosmer-Lemeshow test and the area under the receiver operating characteristic (ROC) curve.Results Among 702 patients in the model group,483 patients were DR,219 patients were NDR.The scores for DR risk were duration of diabetes ≥4.5 years,4 points;total bilirubin ＜6.65 mol/L,2 points;apoA≥ 1.18 g/L,2 points;blood urea≥6.46 mmol/L,1 points;HbA1c ≥7.75％,2 points;HDL-c＜ 1.38 mmol/L,2 points;diabetic neplropathy,3 points;fibrinogen,1 point.The area under the receiver operating characteristic curve was 0.787.The logistic regression analysis showed that the risk factors independently associated with DR were duration of diabetes (β=1.272,OR=3.569,95％CI 2.283-5.578,P＜0.001),TB (β=0.744,OR=2.104,95％CI 1.404-3.152,P＜0.001,BUN (β=0.401,OR=1.494,95％CI 0.996-2.240,P=0.052),HbA1c (β=0.545,OR=1.724,95％CI 1.165-2.55,P=0.006),HDL-c (β=0.666,OR=1.986,95％CI 1.149-3.298,P=0.013),diabetic nephropathy (β=1.151,OR=3.162,95％CI2.080-4.806,P=0.013),Fg (β=0.333,OR=1.396,95％CI 0.945-2.061,P=0.094).The risk model was P=1/[1+exp-(-3.799+1.272X1+0.744X2+0.769X3+0.401X4+0.545X5+0.666X6+1.151X7+0.333X8)].X1=duration of diabetes,X2=TB,X3=apoA,X4=BUN,X5=HbA1c,X6=HDL-c,X7=diabetic nephropathy,X8=Fg.The area under the ROC curve was 0.787 and the Hosmer-Lemeshow test suggested excellent agreement (x2=10.125,df=8,P=0.256) in model group.The area under the ROC curve was 0.869 and the Hosmer-Lemeshow test suggested excellent agreement (x2=5.345,df=7,P=0.618) in model group.Conclusion The area under the ROC curve for DR was 0.787.The duration of diabetes,TB,BUN,HbAlc,HDL-c,diabetic nephropathy,apoA,Fg are the risk factors of DR in T2DM patients.