title: Glomerular expression of connexin 40 and connexin 43 in rat experimental glomerulonephritis.
abstract: BACKGROUND
  Gap junctional intercellular communication is thought to play an important role in the maintenance of cell differentiation and homeostasis. Gap junctions connect glomerular mesangial cells to each other. In this study, we examined the glomerular expression of connexins (Cxs) 40 and 43 at both the protein and transcript levels in anti-Thy1.1 glomerulonephritis (GN).
  
  
  METHODS
  Anti-Thy1.1 GN was induced by intravenous injection of anti-Thy1.1 monoclonal antibody 1-22-3. Cx protein expression was examined by immunofluorescence, immunoelectron microscopy, and Western blotting. Changes in mRNA levels were detected by real-time reverse transcriptase-polymerase chain reaction.
  
  
  RESULTS
  Cx40 was detected in mesangial cells in normal rat glomeruli; its expression was reduced on days 3 and 7 and recovered to normal on day 14 following GN induction. Cx43 was detected in mesangial cells and podocytes in normal rat glomeruli, and its expression did not change during the disease course of GN. Expression of Cx40 and Cx43 was also detected in extraglomerular mesangial cells; this expression did not change during the disease course. Opposing patterns of expression between Cx40 and smooth muscle actin (SMA) were observed with double-immunofluorescence labeling. SMA is a differentiation marker of mesangial cells; it is often expressed during proliferation but not under physiological conditions.
  
  
  CONCLUSIONS
  These results suggest that Cx40 expression in mesangial cells is related to mesangial cell regeneration. Thus, Cx expression regulation could be a therapeutic target for glomerular diseases.
authors.affiliation: Department of Cellular Physiology, Institute of Nephrology, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan. tmorioka@d4.dion.ne.jp
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Morioka
authors.forename: Shinichi
authors.initials: S
authors.lastname: Okada
authors.forename: Masaaki
authors.initials: M
authors.lastname: Nameta
authors.forename: Fadia
authors.initials: F
authors.lastname: Kamal
authors.forename: Nadia T
authors.initials: NT
authors.lastname: Yanakieva-Georgieva
authors.forename: Jian
authors.initials: J
authors.lastname: Yao
authors.forename: Ayako
authors.initials: A
authors.lastname: Sato
authors.forename: Honglan
authors.initials: H
authors.lastname: Piao
authors.forename: Takashi
authors.initials: T
authors.lastname: Oite
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D015153:Blotting, Western; D018031:Connexin 43 / Q000096:biosynthesis*; D017630:Connexins / Q000096:biosynthesis*; D005455:Fluorescent Antibody Technique; D005921:Glomerulonephritis / Q000139:chemically induced / Q000378:metabolism*; D007678:Kidney Glomerulus / Q000378:metabolism*; D008297:Male; D016253:Microscopy, Immunoelectron; D051381:Rats; D017208:Rats, Wistar; D060888:Real-Time Polymerase Chain Reaction; D000097003:Gap Junction alpha-5 Protein
chemical_list: D000911:Antibodies, Monoclonal; D018031:Connexin 43; D017630:Connexins; D000097003:Gap Junction alpha-5 Protein