The importance of locally produced insulin-like growth factor-I (IGF-I) in connective tissues has recently been recognized. It has been postulated that the action of anabolic hormones on bone may be mediated through local IGF-I release. However, whether IGF-I can also be modulated by other locally acting cytokines has not been addressed. Transforming growth factor-beta (TGF beta) is a polypeptide thought to be involved in the regulation of tissue growth and repair. Although the occurrence of TGF beta is ubiquitous, particularly high amounts are found in bone and cartilage. In this study the effect of TGF beta-1 on immunoreactive IGF-I production by osteoblasts and chondrocytes was investigated and compared to that of PTH on osteoblasts or basic fibroblast growth factor (bFGF) on chondrocytes. Both TGF beta-1 and PTH stimulated IGF-I release from osteoblasts, which was further enhanced when both were consecutively present. Contrastingly, although bFGF stimulated IGF-I release by chondrocytes, TGF beta-1 was inhibitory and also blunted the effect of bFGF when both were present concurrently. These findings demonstrate that the regulation of local IGF-I production in bone and cartilage may differ and illustrate the complex nature of local cytokine interactions.
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http://dx.doi.org/10.1210/endo-127-4-1635 | DOI Listing |
Anim Reprod Sci
February 2025
ICAR-Central Inland Fisheries Research Institute, Barrackpore, Kolkata, West Bengal 700 120, India.
Fish oocyte maturation (FOM) is a critical biological process that occurs before ovulation and is influenced by gonadotropins, particularly luteinizing hormone (LH). The release of LH stimulates the ovarian follicle to produce a maturation-inducing hormone (MIH), specifically 17α, 20β-dihydroxy-4-pregnen-3-one (17α, 20β-DP), which initiates the formation of maturation-promoting factor (MPF) through the activation of cyclin B and cdc2 kinase. Insulin-like growth factor I (IGF-I) significantly regulates ovarian functions, including steroidogenesis, by activating its membrane receptors and the tyrosine kinase pathway.
View Article and Find Full Text PDFRev Endocr Metab Disord
November 2024
Maimonides Institute for Biomedical Research of Córdoba (IMIBIC), IMIBIC Building. Av. Menéndez Pidal S/N. 14004, Cordoba, Spain.
Background: Pituitary lesions after traumatic brain injury (TBI) are frequent in children and adolescents, but the rate of post-TBI central hypothyroidism remains uncertain.
Objective: To identify the long-term incidence of post-TBI CH and the clinical and laboratory characteristics of this complication in children and adolescents.
Methods: The analysis included 31 patients with a history of TBI with at least 1 year of follow-up.
Front Horm Res
November 2024
Department of Medicine (DIMED), Clinica Medica 3, Padua University, Padua, Italy.
Acromegaly is a chronic and progressive disorder caused by growth hormone (GH) and insulin-like growth factor 1 (IGF-1) excess, responsible for the onset of multiple systemic complications. Targets of acromegaly treatment are the normalization of hormonal (GH/IGF-1) parameters, the removal/reduction/stabilization of the pituitary mass, the control of existing conditions, and the prevention of new ones, so to improve quality of life and normalize life expectancy. Patients often require a multimodal therapeutic approach, including surgery, medical therapy, and radiotherapy, that allows disease cure/control in the majority of the cases.
View Article and Find Full Text PDFNat Commun
November 2024
Institute of Transfusion Medicine - Transfusion Center, Johannes Gutenberg University Medical Center, 55131, Mainz, Germany.
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