Stimulation of rat mesangial cell proliferation by macrophage interleukin 1.
Conditioned media from LPS-activated rat peritoneal macrophages enhanced the proliferation rates of cultured rat glomerular mesangial cells. This macrophage-derived activity extensively co-purified with interleukin 1 (IL 1) activity through sequential ammonium sulfate precipitation, S-200 gel chromatography, DEAE-cellulose anion exchange chromatography, and phenyl-Sepharose chromatography. In addition, the macrophage-derived factor was heat-labile (80 degrees C) and inactivated by phenylglyoxal, thus allowing tentative identification as IL 1. Macrophage supernatants and purified IL 1 enhanced the proliferative rates of mesangial cells only in the presence of serum; the use of platelet-poor plasma or serum depleted of platelet-derived growth factor was without effect. IL 1 acted to increase the percentage of cycling cells, without a change in the length of the individual cell cycle times. These findings provide a potential mechanism whereby activated macrophages, in combination with platelet factors, enhance mesangial cell proliferation. Such processes may contribute to the mesangial hypercellularity frequently found in immune-mediated glomerulonephritis.
D000818:Animals; D001345:Autoradiography; D002452:Cell Count; D002455:Cell Division; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D003470:Culture Media; D006133:Growth Substances / Q000302:isolation & purification / Q000502:physiology; D007375:Interleukin-1 / Q000302:isolation & purification / Q000502:physiology*; D007678:Kidney Glomerulus / Q000166:cytology*; D008262:Macrophage Activation; D008264:Macrophages / Q000276:immunology*; D008297:Male; D010982:Platelet-Derived Growth Factor / Q000502:physiology; D051381:Rats; D011919:Rats, Inbred Strains
D003470:Culture Media; D006133:Growth Substances; D007375:Interleukin-1; D010982:Platelet-Derived Growth Factor