Artículos de revistas
Regulation of hypoxia-inducible factor-1 alpha (HIF-1 alpha) expression by interleukin-1 beta (IL-1 beta), insulin-like growth factors I (IGF-I) and II (IGF-II) in human osteoarthritic chondrocytes
Registro en:
Clinics. Hospital Clinicas, Univ Sao Paulo, v. 67, n. 1, n. 35, n. 40, 2012.
1807-5932
1980-5322
WOS:000299126500006
10.6061/clinics/2012(01)06
Autor
Sartori-Cintra, AR
de Mara, CS
Argolo, DL
Coimbra, IB
Institución
Resumen
Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) OBJECTIVE: Hypoxia-inducible factor 1 alpha regulates genes related to cellular survival under hypoxia. This factor is present in osteroarthritic chondrocytes, and cytokines, such as interleukin-1 beta, participate in the pathogenesis of osteoarthritis, thereby increasing the activities of proteolytic enzymes, such as matrix metalloproteinases, and accelerating cartilage destruction. We hypothesize that Hypoxia Inducible Factor-1 alpha (HIF-1 alpha) can regulate cytokines (catabolic action) and/or growth factors (anabolic action) in osteoarthritis. The purpose of this study was to investigate the modulation of HIF-1 alpha in human osteoarthritic chondrocytes by interleukin-1 beta (IL-1 beta) and insulin-like growth factors I (IGF-I) and II (IGF-II) and to determine the involvement of the phosphatidylinositol-3kinase (PI-3K) pathway in this process. METHODS: Human osteroarthritic chondrocytes were stimulated with IL-1 beta, IGF-I and IGF-II and LY294002, a specific inhibitor of PI-3K. Nuclear protein levels and gene expression were analyzed by western blot and quantitative reverse transcription-polymerase chain reaction analyses, respectively. RESULTS: HIF-1 alpha expression was upregulated by IL-1 beta at the protein level but not at the gene level. IGF-I treatment resulted in increases in both the protein and mRNA levels of HIF-1 alpha, whereas IGF-II had no effect on its expression. However, all of these stimuli exploited the PI-3K pathway. CONCLUSION: IL-1 beta upregulated the levels of HIF-1 alpha protein post-transcriptionally, whereas IGF-I increased HIF-1a at the transcript level. In contrast, IGF-II did not affect the protein or gene expression levels of HIF-1a. Furthermore, all of the tested stimuli exploited the PI-3K pathway to some degree. Based on these findings, we are able to suggest that Hypoxia inducible Factor-1 exhibits protective activity in chondrocytes during osteoarthritis. 67 1 35 40 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) FAPESP [02/14132-1, 05/00985-0]