title: Expression and Immunohistochemical Localisation of the Gβγ-activated and Calcineurin-Inhibited Adenylyl Cyclase Isoforms in Rat Articular Chondrocytes.
abstract: OBJECTIVE
  To determine the expression and localisation of the Gβγ-activated adenylyl cyclase (AC) isoforms 2, 4, and 7 and calcineurin-inhibited AC isoform 9 in rat articular chondrocytes.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Jumma Research Laboratory and Histology Laboratory, The Aga Khan University, Karachi, from 2009 to 2011.
  
  
  METHODS
  Fresh slices of articular cartilage were taken from various synovial joints of rats of different age groups. The expression of AC isoforms was determined by RT-PCR and immunohistochemistry was performed to localise these isoforms in articular chondrocytes. Tissue sections were processed for immunostaining with respective antibodies. The color was developed by diaminobenzidine.
  
  
  RESULTS
  All the studied AC isoforms were found to be differentially expressed in different zones of the rat articular cartilage. Generally, expression of all AC isoforms studied increased with age. The expression of the AC isoforms through PCR was almost consistent with the localisation of these isoforms by immunohistochemistry.
  
  
  CONCLUSIONS
  These data add to the information about signalling cascades possibly involved in articular chondrocytes. Variable expression of AC isoforms 2, 4, 7, and 9 suggest a role for the signalling cascades regulated by the AC isoforms in articular chondrocytes.
authors.affiliation: Department of Basic Sciences, College of Science and Health Professions, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia.
authors.forename: Ismail
authors.initials: I
authors.lastname: Memon
authors.affiliation: Department of Anatomy, Faculty of Medicine, Kuwait University, Kuwait.
authors.forename: Khalid M
authors.initials: KM
authors.lastname: Khan
authors.affiliation: Department of Biological and Biomedical Sciences, The Aga Khan University, Karachi.
authors.forename: Sammer
authors.initials: S
authors.lastname: Siddiqui
authors.affiliation: Department of Biological and Biomedical Sciences, The Aga Khan University, Karachi.
authors.forename: Siddiqa
authors.initials: S
authors.lastname: Perveen
authors.affiliation: Department of Biochemistry, United Medical and Dental College, Korangi, Karachi.
authors.forename: Muhammad
authors.initials: M
authors.lastname: Ishaq
mesh_terms: D000262:Adenylyl Cyclases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D019703:Calcineurin; D002358:Cartilage, Articular / Q000201:enzymology*; D002478:Cells, Cultured; D019902:Chondrocytes / Q000201:enzymology* / Q000276:immunology; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D020033:Protein Isoforms; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000502:physiology
chemical_list: D020033:Protein Isoforms; D012333:RNA, Messenger; D019703:Calcineurin; D000262:Adenylyl Cyclases; C100622:adenylyl cyclase 2