Biological and biochemical characterization of an interleukin 1‐like factor from rat C₆ glioma cells

Abstract

It has been previously reported that lipopolysaccharide-stimulated murine astrocytes produce a factor which enhances the proliferative response of thymocytes to lectins. The present report demonstrates that a rat astrocytoma cell (C6 cells)-derived factor appears to be similar to macrophage-derived interleukin 1 (IL 1) in its biological activities and biochemical characteristics. Upon injection into mice, supernatants of C6 cells induce the production of serum amyloid A. The C6 cell-derived factors enhance the response of thymocytes to phytohemagglutinin and the growth of fibroblasts whereas no effect on the growth of neuroblasts and of a strictly interleukin 2 (IL 2)-dependent T cell line was observed. On an AcA 54 column the C6-derived factors acting on thymocytes and fibroblasts coeluted as a single peak of Mr = 13 500 to 18 000; the semipurified factor was found to enhance the lymphocytes' production of IL 2. These observations demonstrate that cells not belonging to the mononuclear phagocyte lineage are able to produce factors identical or closely related to IL 1.

Heightened expression of tumor necrosis factor alpha, interleukin 1 alpha, and glial fibrillary acidic protein in experimental Creutzfeldt-Jakob disease in mice.

“…The vacuolation of myelinated axons in experimental CJD (2), scrapie (3, 4), and kuru (5) closely resembles that induced by tumor necrosis factor a (TNF-a) in murine spinal cord organotypic cultures (6) and that found in demyelinating diseases, such as experimental allergic encephalitis (EAE) (7-11) and multiple sclerosis (MS) (12, 13). Moreover, our recent studies indicate similar pathological lesions in the optic nerves of mice after intraocular inoculation with recombinant murine TNF-a (14).TNF-a and interleukin la (IL-la) are synthesized in microglia and astrocytes (15)(16)(17)(18)(19)(20), and immunopositivity for these cytokines has been detected in neurons (20 …”

“…TNF-a and interleukin la (IL-la) are synthesized in microglia and astrocytes (15)(16)(17)(18)(19)(20), and immunopositivity for these cytokines has been detected in neurons (20 …”

The role of the ubiquitin/proteasome system in cellular responses to radiation

“…Genomic sequencing has recognized more than 90 deubiquitinylating cysteine protease enzymes (Fontana et al, 1982). Deubiquitinylating enzymes (DUBs) play roles in Ub recycling, can reverse Ub, and edit inappropriately ubiquitinylated proteins.…”

“…Families of Ub-like molecules (Ubl) are being discovered that act antagonistically to, or independently of, Ub to control the fate and function of proteins (Yeh et al, 2000). A plethora of deubiquitinylating enzymes (Fontana et al, 1982) have been identified that must play key roles in moderating and reversing Ub, although their physiological functions are still largely unknown (Chung and Baek, 1999;Wilkinson, 2000).…”

A central nervous system defect in biosynthesis of corticotropin-releasing hormone is associated with susceptibility to streptococcal cell wall-induced arthritis in Lewis rats.

“…rIL-la (1 fM to 1 ,uM) induced a 150% increase in iCRH secretion over baseline from F344/N hypothalami (P < 0.001, ANOVA) and a 10%o increase in iCRH secretion over baseline from LEW/N hypothalami (not significant, ANOVA). Bacterial endotoxin (lipopolysaccharide, similar to SCW) and IL-1 have been shown to augment levels ofCRH, ACTH, and corticosterone through stimulation of the HPA axis at multiple levels (35)(36)(37)(38)(39)(40)(41)(42)(43)(44). Since SCW induces IL-1 release (45), IL-1 is one probable mediator of SCW-induced HPA-axis stimulation.…”