Intracellular collagen-like material in mouse embryonic mesenchymal cells incubated with TNF-alpha and IL-1 beta in organoid culture.
Blastemal cells of embryonic mouse limb buds (day 12) were cultivated in organoid cultures in the presence of the human recombinant cytokines interleukin-1 beta (IL-1 beta) and tumour necrosis factor alpha (TNF-alpha). The effects of both cytokines (applied alone or together) on mesenchymal cells were demonstrated by electron microscopy. Cultures treated with TNF-alpha (alone or in combination with IL-1 beta) showed several mesenchymal cells with numerous irregularly shaped membrane-bordered cavities containing thick bundled tannic-acid-positive fibrillar structures that resembled loosened collagen fibrils, whereas cells exposed to IL-1 beta alone did not exhibit such changes. These findings are discussed in the light of two hypotheses: the phagocytosis of extracellular collagen fibrils, and fibrillogenesis resulting from incongruity of synthesis and secretion rates of procollagen; our results favour the former.
Mohamed-Ali
H
H
Institute of Anatomy, Free University of Berlin, Germany.
Scholz
P
P
Merker
H J
HJ
D000818:Animals; D003094:Collagen / Q000032:analysis*; D004622:Embryo, Mammalian / Q000737:chemistry / Q000166:cytology; D006801:Humans; D007375:Interleukin-1 / Q000494:pharmacology*; D018878:Limb Buds / Q000737:chemistry / Q000166:cytology*; D008648:Mesoderm / Q000737:chemistry* / Q000187:drug effects / Q000648:ultrastructure; D051379:Mice; D008854:Microscopy, Electron; D009924:Organ Culture Techniques; D011994:Recombinant Proteins / Q000494:pharmacology; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D007375:Interleukin-1; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; D003094:Collagen