Objective CXCR4-overexpressing bone marrow-derived mesenchymal stem cells (CXCR4-BMSC) were constructed and co-cultured with hypoxia/re-oxygenation pretreated renal tubular epithelial cells (HR-RTEC).Repair of HR-RTEC was detected and the possible mechanism was also discussed.Methods CXCR4-BMSC (CXCR4-BMSC/eGFP,eGFP as the tracer gene) and null-BMSC (BMSC/eGFP) were obtained by gene transfection technique,and the level of CXCR4 in the transfected cells was detected.RTEC was cultured under hypoxia/re-oxygenation condition for 12 h,respectively,to obtain HR-RTEC,which was used to simulate AKI in vitro.BMSC and HR-RTEC were co-cultured for 12 h,and the proportion of apoptotic cells among the HR-RTEC was assayed by immunofluorescence technique.Western blot was used to test the protein levels of cleaved Caspase-3 and Bcl-2.The number of migrating BMSC was also assayed.After culturing with the HR-RTEC culture supernatant,the expression of cytokeratin 18 (CK18) in BMSC was tested by immunofluorescence staining.Cytokines including bone morphogenetic protein-7 (BMP-7),hepatic growth factor (HGF) and interleukin-10 (IL-10) in the BMSC culture supernatant were detected by ELISA method.Results Expression of CXCR4 was enhanced in CXCR4-BMSC.Proportions of the apoptotic cells among HR-RTEC after being co-cultured with BMSC,CXCR4-BMSC and null-BMSC were all decreased,especially in the C/H group.The decreased cleaved Caspase-3 and enhanced Bcl-2 were also observed in HR-RTEC.The number of migrating CXCR4-BMSC was the highest.Proportions of CK18+ cells in BMSC,CXCR4-BMSC and null-BMSC were all low and showed no difference.However,CXCR4 overexpression in BMSC stimulated secretions of BMP-7,HGF and IL-10.Conclusions CXCR4-overexpressing BMSC has more repair effect on the co-cultured HR-RTEC,the enhanced migration ability and secretion ability of CXCR4-BMSC are the possible mechanisms.

Objective To compare the effect of video‐assisted thoracoscopic(VAT) surgery and conventional thoracotomy in emergency treatment of multiple rib fracture complicating pulmonary laceration to provide the reference for clinical treatment .Meth‐ods Forty‐seven cases of multiple rib fracture complicating pulmonary laceration in our hospital from April 2013 to April 2014 were selected and divided into the VAT group(n=32) and thoracotomy group(n=15) according to the willingness of patients .The two groups performed the thoracoscopic and traditional thoracotomy titanium nickel alloy rib plate treatment respectively .The sur‐gery situation ,complications and changes of perioperative blood gas levels were compared between the two groups .Results The op‐eration time ,intraoperative bleeding volume ,ICU hospitalization time ,total hospitalization time and postoperative analgesic in the VAT group were lower than those in the thoracotomy group ,the differences were statistically significant (P<0 .05);the VAS score on postoperative 1 d had statistical difference(P<0 .01) .Compared with before operation ,arterial PaO2 ,SaO2 and PaO2/FiO2 at postoperative 12 h in the two groups were increased ,while PaCO2 was decreased ,and the differences were statistically significant (P<0 .05);PaO2 ,SaO2 and PaO2/FiO2 at postoperative 12 h in the VAT group were higher than those in the thoracotomy group , while PaCO2 was lower than that in the thoracotomy group ,and the differences were statistically significant (P<0 .05) .The occur‐rence rate of complications had no statistical difference between the VAT group and thoracotomy group (3 .1% vs .6 .7% ,P>0 .05) .The excellent rate in the VAT group was 90 .6% ,which was higher than 66 .7% in the thoracotomy group ,and the differ‐ence was statistically significant (P<0 .05) .Conclusion Thoracoscopic internal fixation for the treatment of multiple rib fractures complicating laceration has the advantages of minimal trauma ,convenient operation and high safety ,could effectively alleviate the patient′s sufferring ,improve the living quality ,and be a better way of treatment .

Objective To investigate the migration of bone-marrow mesenchymal stem cells (BMSCs) under acute kidney injury (AKI) microenvironment in vitro and the effect of erythropoietin (EPO) intervention,and to explore its underlying mechanism.Methods Renal tubular epithelial cells (RTECs) were cultured in hypoxia/re-oxygenation (HR) condition for 12 h,respectively,in order to establish HR-RTEC.BMSCs and RTECs were co-cultured by Transwell system and were divided into 7 groups:control group (group①,only BMSC cultured),BMSC-RTEC co-culturing group (group ②),BMSC-HR-RTEC co-culturing + EPO intervention groups (group ③to group ⑦,EPO concentration:0,1,5,10,50 IU/ml).All the groups were cultured for 48 h and the number of migrating BMSCs was detected.Western blotting was applied for the detection of SDF-1 expression in RTECs and pMAPK and MAPK levels in BMSCs.SDF-1 concentration in the RTECs culture supernatant was tested by ELISA.Results The number of BMSCs migrating to the low chamber where HR-RTECs were cultured was increased,and EPO intervention further enhanced this migration which reached the peak at the concentration of 10 IU/ml [Compared with group③,(46.67±7.37) cells vs (19.00±2.37) cells,P ＜ 0.05].Intracellular expression level and the secreated level of SDF-1 in HR-RTECs in group③ were higher than those in RTECs of group② [0.37±0.01 vs 0.19±0.01,P ＜ 0.05; (61.64±4.88) μg/L vs (35.26±8.78) μg/L,P ＜ 0.05].EPO intervention increased above SDF-1 levels and reached the peak at the concentration of 10 IU/ml [group⑥ vs group③:(173.53± 14.66) μg/L vs (61.64±4.88) μg/L,P＜0.05],accompanied with enhanced phosphorylation of MAPK in BMSCs.Conclusions AKI microenvironment has obvious chemotaxis effect on BMSCs,and EPO intervention can strengthen this effect.The increased SDF-1 level and enhanced phosphorylation of MAPK,the downstream signal protein of SDF-1/CXCR4 axis,are the possible mechanism for EPO performance.

Objective There are a few reports on rats with spontaneous congenital cataract in China .The purpose of this study was to investigate the morphological changes of lens in rats with spontaneous congenital cataract . Methods 24 d, 1-year rats with cataract and microphthalmos cataract and normal rats (n=5) were selected as research objects .Their lens were observed by a slit lamp microscope and taken photos in front of them , followed by examination through light micrograph and transmission electron micros-copy. Results Rats with microphthalmos cataract showed narrowed palpebral fissure and broaden nucleus while rats with cataract showed normal palpebral fissure and narrowed nucleus .As for 24 d,1-year rats with microphthalmos cataract , the fibers of their lens showed derangement and vacuole-like degeneration by light microscope , in addition, the abnormal connection between fiber cells were observed by electron microscopy .As for 1-year normal rats , the fibers were in consistent structure and regular arrangement without cell ingredient . Conclusion The appearance and morphological changes of the lens in rats with spontaneous congenital cataracts are in consistence with the pathological changes of cataracts , which is appli-cable in further research on the pathogenesis of cataract .

OBJECTIVETo observe the developing changes of adventitia in restenosis after precutaneous transluminal angioplasty(PTA), and investigate the effect of androgen on restenosis through contrasting the castrated male rat models and its mechanism.

METHODSModels were constructed of castrated male rats and restenosis of the common carotid artery, and specimens were collected at the 3rd, 7th, 14th and 28th day respectively after modeling. Hematoxylin and eosin staining, immunohistochemical staining, and electronic microscopy were performed to observe the condition of restenosis.

RESULTSProliferating cells occurred in adventitia first and phenotype of adventitial cells was changed at the 3rd day after PTA. The adventitial proliferating index was the highest at the 7th day after PTA, and proliferating migration towards intimal was observed. The proliferating cells mostly occurred in the middle layer and neointima at the 14th day after PTA. The areas of adventitia and neointima were larger and the degrees of restenosis were higher in the castrated rats than in the non-castrated ones at different time points. Take the 14 d group, the adventitial area was[(3,566 +/- 337) micron2 vs (2,751 +/- 401) micron2, P = 0.008], the neointimal area[(3,553 +/- 477) micron2 vs (2,757 +/- 435) micron2, P = 0.025], the restenosis rate[(76 +/- 2)% vs (60 +/- 8)%, P = 0.005], and the proliferating index [(29 +/- 2)% vs (13 +/- 1)%, P < 0.001].

CONCLUSIONAdventitial proliferation and migration contribute to restenosis after PTA; Androgen in rats can physiologically relieve restenosis, probably through intervening in the activation of adventitia.

Actins ; analysis ; Androgens ; physiology ; Angioplasty, Balloon, Coronary ; Animals ; Bromodeoxyuridine ; metabolism ; Coronary Restenosis ; etiology ; pathology ; Coronary Vessels ; pathology ; ultrastructure ; Immunohistochemistry ; Male ; Orchiectomy ; Rats ; Rats, Sprague-Dawley

Bacterial Outer Membrane Proteins ; chemistry ; genetics ; metabolism ; Escherichia coli Proteins ; chemistry ; genetics ; metabolism ; Glutamic Acid ; genetics ; metabolism ; Histidine ; genetics ; Hydrogen-Ion Concentration ; Ion Channel Gating ; genetics ; Lipid Bilayers ; metabolism ; Mutant Proteins ; chemistry ; genetics ; metabolism ; Mutation ; Porins ; chemistry ; genetics ; metabolism

Electron Spin Resonance Spectroscopy ; Glycerol ; chemistry ; Mesylates ; chemistry ; Muramidase ; chemistry ; Protein Structure, Tertiary ; Proteins ; chemistry ; Spin Labels ; Temperature ; Viscosity

Electron Spin Resonance Spectroscopy ; Magnetic Resonance Spectroscopy ; Models, Molecular ; Protein Structure, Tertiary ; Proteins ; chemistry

Mycosin-1 protease (MycP1) is a serine protease anchored to the inner membrane of Mycobacterium tuberculosis, and is essential in virulence factor secretion through the ESX-1 type VII secretion system (T7SS). Bacterial physiology studies demonstrated that MycP1 plays a dual role in the regulation of ESX-1 secretion and virulence, primarily through cleavage of its secretion substrate EspB. MycP1 contains a putative N-terminal inhibitory propeptide and a catalytic triad of Asp-His-Ser, classic hallmarks of a subtilase family serine protease. The MycP1 propeptide was previously reported to be initially inactive and activated after prolonged incubation. In this study, we have determined crystal structures of MycP1 with (MycP1²⁴⁻⁴²²) and without (MycP1⁶³⁻⁴²²) the propeptide, and conducted EspB cleavage assays using the two proteins. Very high structural similarity was observed in the two crystal structures. Interestingly, protease assays demonstrated positive EspB cleavage for both proteins, indicating that the putative propeptide does not inhibit protease activity. Molecular dynamic simulations showed higher rigidity in regions guarding the entrance to the catalytic site in MycP1²⁴⁻⁴²² than in MycP1⁶³⁻⁴²², suggesting that the putative propeptide might contribute to the conformational stability of the active site cleft and surrounding regions.
Amino Acid Sequence ; Bacterial Proteins ; chemistry ; Bacterial Secretion Systems ; Crystallography, X-Ray ; Humans ; Molecular Dynamics Simulation ; Molecular Sequence Data ; Mycobacterium smegmatis ; metabolism ; Protein Precursors ; chemistry ; Protein Structure, Tertiary ; Subtilisins ; chemistry

Escherichia coli ; enzymology ; Fluorine Radioisotopes ; analysis ; Lipid Bilayers ; chemistry ; Magnetic Resonance Spectroscopy ; Maleates ; chemistry ; Nanoparticles ; chemistry ; Phosphorylation ; Polystyrenes ; chemistry ; Protein Conformation ; Protein-Tyrosine Kinases ; chemistry ; metabolism ; Tyrosine ; metabolism