Production and secretion of interleukin-1alpha proteins by rat testis.
The present study characterizes constitutively expressed rat testicular interleukin-1alpha (IL-1alpha) proteins. IL-1 bioactivity of crude testis protein was completely neutralized by IL-1alpha antiserum, IL-1 receptor antagonist, and soluble type I IL-1 receptor. Upon non-denaturating gel permeation chromatography, bioactive IL-1 eluted at molecular sizes of 45, 31, and 17kDa and at charges of pH 5.7 and 6.0 after chromatofocusing. SDS-PAGE/Western blot analysis of proteins extracted from whole testis, seminiferous tubules, interstitial, and seminiferous tubule fluids all demonstrated IL-1alpha immunoreactivity at 45, 24, and 19kDa. Activated macrophages and tissue proteins from endotoxin treated rats showed immunoreactive 31 and 19kDa IL-1alpha. The results indicate that the testis produces three isoforms of IL-1alpha proteins that are secreted into the interstitial compartment and tubular lumen where they may exert paracrine functions. The testicular IL-1alpha isoforms may represent posttranslationally modified precursor, mature IL-1alpha, and a 24-kDa alternate splice form.
Gustafsson
Katarina
K
Pediatric Endocrinology Unit, Q2: 08, Department of Woman and Child Health, Astrid Lindgren Children's Hospital, SE-171 76 Stockholm, Sweden.
Sultana
Taranum
T
Zetterström
Cecilia K
CK
Setchell
Brian P
BP
Siddiqui
Arif
A
Weber
Günther
G
Söder
Olle
O
D000818:Animals; D002455:Cell Division; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000096:biosynthesis; D007375:Interleukin-1 / Q000096:biosynthesis* / Q000302:isolation & purification / Q000378:metabolism; D008297:Male; D051379:Mice; D008970:Molecular Weight; D051381:Rats; D017207:Rats, Sprague-Dawley; D013737:Testis / Q000276:immunology*
D007375:Interleukin-1; D004247:DNA