Research progress of proximity labeling technology based on biotin ligase in proteomics / 中国药科大学学报

@#Proximity-dependent biotinylation (PDB) uses biotin ligase fused to the protein of interest to biotinylate adjacent proteins, purify them with streptavidin beads, and then identify the biotinylated protein by mass spectrometry.This technology can be used to detect transient and/or low affinity interactions, provide a chance to learn more about membrane-less organelles and other subcellular structures that cannot be easily isolated or purified, and fill the gap in traditional methods.This article summarizes the technological development and application of PDB in recent years.

ROLE OF TUMOR MARKERS IN CERVICAL CARCINOGENESIS

Various types of tumor markers are currently being investigated to ascertain their capability in discriminating pre-cancerous lesions of cervix who have tendency for progression. The adequate treatment of such cases will check any chances of occurrence of carcinoma cervix in the population. The micro- RNAs are sensitive tumor markers but their high cost and sophisticated technique make them not feasible to be introduced in any cervical cancer screening program under Indian setup. Other tumor markers like claudins, p16, Ki67 etc are also very expensive. AgNOR pleomorphic counts and micronuclei counts are cheaper, the farmer being more reliable can be introduced in cytological screening program to identify high risk cases and can easily replace costly Human papilloma virus (HPV)- DNA testing.

Analysis of protein expression profiling in a mouse model of oxygen-induced retinopathy / 中华实验眼科杂志

Background Retinal neovascularization (RNV) is one of the major causes of blindness worldwide,but the pathogenic mechanism of this disease remains unclear, and therapeutic modalities need to be improved.Therefore,it is necessary to identify ocular protein markers with significant expression changes during RNV, thereby providing novel therapeutic targets for neovascular retinopathies.Objective This study was to investigate retinal vessel morphological characteristics and protein expression profiling in a mouse model of oxygen-induced retinopathy (OIR).Methods Forty four C57BL/6J mouse pups were randomly divided into normal control group and OIR group at postnatal day 7 (P7).The mice in the normal control group were raised under the normal air for 10 days.The mice of the OIR group were exposed to (75±2)％ oxygen for 5 days.The mother mice were alternated between the two groups every day.The mice of the OIR group returned to normal air at P12.Fluorescein isothiocyanate-dextran (FITC-dextran) was retrobulbarly injected at P17 mice from both groups, and the retinal flatmounts were prepared after fixation.The FITC-dextran-labeled retinal vessels were observed and quantified;the paraffin sections of eyeballs were processed for hematoxylin and eosin staining,and the number of pre-retinal vascular cell nuclei was quantified.The total proteins were extracted from the eyes, and the expression profiling was analyzed by a customized protein array and verified by Western blot and ELISA.Results The retinal flatmounts labeled with FITC-dextran showed that the peripheral retinal microvessels in the OIR group were tortuous, disorganized with neovascular buds,and the vascular obliteration was prominent in the center of retina.Contrastly,the vessels were smooth,organized, and evenly distributed in the normal control group.The percentage of vascular obliteration area in the OIR group was (25.53±2.16)％ ,which was significantly higher than (0.66±0.36)％ in the normal control group (t=-27.61 ,P＜ 0.01).The number of pre-retinal vascular cell nuclei,as revealed by hematoxylin and eosin staining, was (28.41 ± 3.97)/slide in the OIR group, which was substantially higher than (0.16±0.31)/slide in the normal control group (t =-54.42,P＜0.001).Protein array showed that 10 out of the 62 examined pro-inflammatory, pro-angiogenic cytokines exhibited more than 1.5-fold expression changes,including 3 up-regulated cytokines and 7 down-regulated cytokines;4 cytokines showed more than 2-fold expression changes,in which 3 cytokines were down-regulated and 1 cytokine was up-regulated.The differential expressions were verified by Western blot and ELISA.The expression trends of platelet factor 4 (PF-4), vascular endothelial growth factor A (VEGF-A), selectin P (SELP), vascular cell adhesion molecule 1 (VCAM-1) ,soluble tumor necrosis factor receptor Ⅱ (sTNF-RⅡ) and chemokine C-X-C motif ligand 16 (CXCL16) were consistent with those revealed by protein array.PF-4,VEGF-A and SELP were up-regulated,and the other 3 were significantly down-regulated (all at P＜0.05).Conclusions Differential expression patterns of the cytokines,including PF-4,VEGF-A, SELP, VCAM-1, sTNF-RⅡ and CXCL16, are identified between normal and OIR mouse eyes.These differential expression patterns suggest that under the condition of OIR,the platelet system is activated,and proinflammatory factors are down-regulated.PF-4 might become a new target for VEGF-independent therapeutic strategy against RNV.

Urinary protein markers predict the severity of renal histological lesions in children with IgA nephropathy and IgM nephropathy / 中华实用儿科临床杂志

Objective To compare the clinical manifestations,renal histological lesions,and the levels of urinary protein markers between the children with IgA nephropathy (IgAN) and those with IgM nephropathy (IgMN), and to determine whether urinary protein markers could predict the severity of renal histological lesions in children with IgAN and IgMN.Methods Seventy-four children with renal biopsy-proven IgAN and IgMN from January 2002 to October 2014 were enrolled in the study.The levels of IgG, albumin (Alb), transferrin (TRF), α1-microglobulin (α1-MG) ,β2-microglobulin (β2-MG) and N-acetyl-β-glucosaminidase (NAG) in morning urine samples before biopsy were measured.The semi-quantitative scores of mesangial hypercellularity (MC), glomerulosclerosis (GS), and tubule-interstitial damage (TID) were used to assess renal histological lesions.Multivariate Logistic regression analysis was used to determine whether urinary protein levels were independently associated with renal histological lesions.The area under the receiver-operating-characteristic curve (AUC) was calculated to assess the predictive ability of urinary protein markers.Results Seventy-four children (44 cases with IgAN,30 cases with IgMN) were included.The urinary levels of α1-MG and Alb were significantly higher in children with IgAN as compared to those with IgMN.The differences, however, did not remain significant after adjustment for age.The urine protein, as an independent factor associated with severe MC(＞ 5 mesangial cells per mesangial area) was TRF(B =0.010), and severe GS (≥ 10％ glomeruli showing segmental adhesion or sclerosis) was significantly correlated with Alb(B =0.001) ,and severe TID (focal or diffuse tubular and interstitial lesions) was significantly correlated with NAG(B =0.038).Urinary β2-MG was not significantly associated with severe MC, GS and TID.Urinary TRF, Alb and NAG achieved the best AUC of 0.85 (P ＜ 0.001) ,0.78 (P =0.002), and 0.78 (P =0.003), respectively, for predicting severe MC, GS, and TID.Conclusions Urinary proteins are useful to predict the severity of renal histological lesions in children with IgAN and IgMN.Urinary TRF, Alb and NAG have better predictive value.