Reduced pericellular sensitivity to IGF-I in fibroblasts from girls with Turner syndrome: a mechanism to impair clinical responses to GH.
Pediatr Res
; 70(1): 25-30, 2011 Jul.
Article
en En
| MEDLINE
| ID: mdl-21430600
ABSTRACT
Girls with Turner syndrome (TS) are treated with supraphysiological doses of growth hormone (GH) to improve final height; however in some girls, the growth response can be poor. This may reflect aberrations in GH and/or IGF-I actions at the cellular level, and thus this study compared the response of skin fibroblasts from normal children (n = 5) and girls with TS (n = 8) to GH, IGF-I, or a combination, by assessing the IGF binding protein (IGFBP) profile of conditioned medium harvested over 7 d. The two cell types had a comparable IGFBP profile; IGFBP-3 and IGFBP-4 were the most abundant species. TS fibroblasts produced more IGFBP-3 (d 7, 51.4 ± 45 ng/mL versus 20 ± 22 ng/mL; p < 0.05) than control cells; levels of IGFBP-4 were similar (21 ± 12 ng/mL versus 30 ± 21 ng/mL). GH did not influence IGFBP production. IGF-I treatment did not affect IGFBP-4 levels but enhanced the production of IGFBP-3 by both cell types (p < 0.05). However, the response of TS fibroblasts to IGF-I was approximately half that observed in normal cells (p < 0.05). Altered IGF-I activity, because of reduced bioavailability and/or reduced sensitivity, could contribute to the need for high GH doses in TS and for the poor response to GH in some girls with TS.
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Banco de datos:
MEDLINE
Asunto principal:
Piel
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Síndrome de Turner
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Factor I del Crecimiento Similar a la Insulina
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Hormona del Crecimiento
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Fibroblastos
Tipo de estudio:
Diagnostic_studies
Límite:
Female
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Humans
Idioma:
En
Año:
2011
Tipo del documento:
Article