title: Expression and regulation of the prointerleukin-1alpha processing enzymes calpain I and II in the rat testis.
abstract: Interleukin-1alpha (IL-1alpha) is constitutively expressed in an age- and stage-dependent manner by rat Sertoli cells. However, the mechanism of regulation of IL-1alpha is unclear in testis. We studied this regulation at the level of the enzyme calpain, a potential regulator that cleaves 32 kDa proIL-1alpha to produce mature 17 kDa IL-1alpha. Both calpain I and II were found to cleave recombinant rat testis 32proIL-1alpha in vitro. A temporary age-related increase in messenger RNA (mRNA) levels of calpain I was found in testis of 20- and 25-day-old rats, coinciding with important events of spermatogenesis and a gradual increase in IL-1alpha, while calpain II expression was constant. In response to lipopolysaccharide (LPS), calpain I protein levels were down-regulated in the seminiferous tubules, while calpain II was less affected. By contrast, the liver after LPS treatment showed up-regulated calpain I and II immunoreactive protein and reverse transcriptase chain reaction (RT-PCR) signal. Depleting Leydig cells by ethane 1,2-dimethane sulphonate treatment resulted in down-regulated calpain I mRNA and protein expression, whereas calpain II remained unchanged. In summary, there is a differential expression of calpain I and II under pathological conditions induced either by endotoxin stimuli or Leydig cell depletion, which may produce a differential effect on IL-1alpha processing.
authors.affiliation: Department of Molecular Medicine, Tumor Biochemistry Unit, Karolinska Institutet and Hospital, Stockholm, Sweden. taranum.sultana@kbh.ki.se
authors.forename: Taranum
authors.initials: T
authors.lastname: Sultana
authors.forename: Aida
authors.initials: A
authors.lastname: Wahab-Wahlgren
authors.forename: Monique
authors.initials: M
authors.lastname: Assmus
authors.forename: Martti
authors.initials: M
authors.lastname: Parvinen
authors.forename: Günther
authors.initials: G
authors.lastname: Weber
authors.forename: Olle
authors.initials: O
authors.lastname: Söder
mesh_terms: D000367:Age Factors; D000818:Animals; D002154:Calpain / Q000235:genetics* / Q000378:metabolism*; D015971:Gene Expression Regulation, Enzymologic; D007249:Inflammation / Q000201:enzymology; D007375:Interleukin-1 / Q000378:metabolism*; D007985:Leydig Cells / Q000201:enzymology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D011498:Protein Precursors / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017207:Rats, Sprague-Dawley; D012671:Seminiferous Tubules / Q000201:enzymology; D012708:Sertoli Cells / Q000201:enzymology; D013091:Spermatogenesis / Q000502:physiology; D013737:Testis / Q000166:cytology / Q000201:enzymology*
chemical_list: D007375:Interleukin-1; D008070:Lipopolysaccharides; D011498:Protein Precursors; D012333:RNA, Messenger; C043830:interleukin 1 precursor; D002154:Calpain