ABSTRACT
To investigate the expressions of mucosal barrier proteins in colon cell line DLD-1 under hypoxic environment and its mechanism. Methods After DLD-1 cells were treated separately with hypoxia(l% O),vitamin D(100 nmol/L),or vitamin D plus hypoxia for 48 hours,the expressions of vitamin D receptor(VDR),tight junction proteins zonula occludens-1(ZO-1),occludin,Claudin-1,and adherent junction protein(E-cadherin)were determined by Western blot.Stable VDR knock-down(Sh-VDR)DLD-1 cell line and control DLD-1 cell line were established by lentivirus package technology and the protein expressions after hypoxia treatment were detected. Results Compared with control group,the expressions of occludin,Claudin-1,and VDR increased significantly after hypoxia treatment(all <0.001).In addition to the protein expressions of occludin,Claudin-1 and VDR,the expressions of ZO-1 and E-cadherin were also obviously higher in vitamin D plus hypoxia group than in single vitamin D treatment group(all <0.001).After hypoxia treatment,Sh-VDR cell line showed significantly decreased expressions of ZO-1(<0.001),occludin(<0.05),Claudin-1(<0.01)and E-cadherin(<0.001)when compared with untreated Sh-VDR cell line. Conclusion VDR acts as a regulator for the expressions of intestinal mucosal barrier proteins under hypoxia environment in DLD-1 colon cell line,indicating that VDR pathway may be another important protective mechanism for gut barrier in low-oxygen environment.
Subject(s)
Humans , Antigens, CD , Metabolism , Cadherins , Metabolism , Cell Hypoxia , Cell Line , Claudin-1 , Metabolism , Colon , Cell Biology , Occludin , Metabolism , Receptors, Calcitriol , Metabolism , Tight Junctions , Vitamin D , Pharmacology , Zonula Occludens-1 Protein , MetabolismABSTRACT
<p><b>OBJECTIVE</b>To study clinical effects of the over-articular external fixator combined with limited internal fixation for the treatment of Pilon fractures caused by high energy.</p><p><b>METHODS</b>From September 2003 to April 2011, 36 patients with Pilon fractures caused by high energy were treated with the over-articular external fixator combined with limited internal fixator. There were 25 males and 11 females, ranging in age from 16 to 72 years old,with an average of 38 years old. The diagnoses of all patients were determined by conventional X-ray examination or three-dimensional spiral CT examination. The AOFAS scoring criteria was used to evaluate the therapeutic effects. The patients with comminuted fractures were treated with screw or Kirschner wire fixation without uncovering periost so as to enhance stability between fracture end and bone blocks,followed by the fixation with over-articular external fixators.</p><p><b>RESULTS</b>All the patients were followed up, and the duration ranged from 4 to 27 months, with an average of 13 months. Thirty-two patients got wound healing at the first stage. And the bone union duration ranged from 2 to 6 months, with a mean of 3 months. According to the AOFAS ankle-hindfoot subjective scoring standard, 13 patients got an excellent result, 20 good and 3 fair, with an score of 88.2 +/- 3.6. Twelve patients had infections at pinhole, 5 patients had pinhole pain. One patient had the fixator broken induced by over loading, who was cured after treatment. There were no complications such as nerve or vascular injuries, or osteomyelitis.</p><p><b>CONCLUSION</b>The over-articular external fixation combined with limited internal fixation for the treatment of Pilon fractures caused by high energy is an ideal method, which has such advantages as reliable fixation, simple operation, coincidence with principles of biomechanical fixation, and benefit for fracture healing.</p>