Interleukin 6: insights to its function in skin by overexpression in transgenic mice.
Interleukin 6 (IL-6) is a cytokine that mediates a wide range of inflammatory and immune responses. Its expression is elevated in inflammatory or immunodeficient diseases, including psoriasis, rheumatoid arthritis, and AIDS. To explore the role of IL-6 in skin, we utilized a human keratin 14 (K14) promoter to express IL-6 in the basal cells of stratified squamous epithelia of transgenic mice. Mice expressing the K14-IL-6 transgene were smaller than normal and exhibited retarded hair growth. Surprisingly, IL-6 expression did not lead to enhanced epidermal proliferation, but it did result in a thicker stratum corneum, with an otherwise seemingly normal program of differentiation. IL-6 expression did not lead to leukocytic infiltration, making it unlikely that it has direct proinflammatory activity in skin. Based on this study, one role of IL-6 relevant to host defense may be to enhance the stratum corneum, thereby providing increased protection from injurious stimuli or infection. If IL-6 plays additional roles in the skin, it is likely to act synergistically with factors that IL-6 alone cannot induce.
Turksen
K
K
Howard Hughes Medical Institute, Department of Molecular Genetics and Cell Biology, University of Chicago, IL 60637.
Kupper
T
T
Degenstein
L
L
Williams
I
I
Fuchs
E
E
D000818:Animals; D001483:Base Sequence; D004848:Epithelium / Q000502:physiology; D015870:Gene Expression; D007249:Inflammation / Q000473:pathology; D015850:Interleukin-6 / Q000502:physiology*; D015603:Keratinocytes / Q000502:physiology; D007633:Keratins / Q000235:genetics; D007962:Leukocytes / Q000166:cytology; D051379:Mice; D008822:Mice, Transgenic; D008969:Molecular Sequence Data; D009693:Nucleic Acid Hybridization; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D010641:Phenotype; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D012867:Skin / Q000166:cytology; D012879:Skin Physiological Phenomena
D015850:Interleukin-6; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D007633:Keratins