Expression of the growth hormone receptor isoforms and its correlation with the metabolic profile in morbidly obese subjects
- 52 Downloads
Background and aim of the study
Given the lipolytic effect of GH and its potential role in determining adipose tissue distribution, we evaluated the expression of the GH hormone receptor (GHR) isoforms in patients with morbid obesity seeking associations with metabolic parameters.
262 morbidly obese subjects (mean age 42.5 ± 11 years, 75% women) underwent PCR-genotyping of the exon 3 GHR polymorphism. In 17 of these subjects, who proved to be heterozygous for the exon 3 genotype (+3/−3), subcutaneous and visceral adipose tissue was obtained during bariatric surgery; total RNA was extracted, reversely transcribed, and the different isoforms of the GHR (exon 3 containing and lacking flGHR as well as the trGHR) were PCR-amplified using specific primers.
27% were +3/+3 homozygous, 20% −3/−3 homozygous and 53% were +3/−3 heterozygous. Compared to subjects homozygous for the +3 genotype, homozygous and heterozygous carriers of the −3 genotype were significantly heavier and tended to have a higher HOMA 2-IR. Expression of the flGHR and trGHR mRNA was demonstrated in all evaluated samples of subcutaneous and visceral adipose tissue from the 17 patients. The exon 3+ isoform was expressed in all adipose tissue samples, whereas only six subjects expressed the 3− isoform as well. The only distinctive feature of these six patients was a higher HbA1c.
The heterozygous GHR +3/−3 genotype is more prevalent in subjects with morbid obesity. Patients expressing the exon +3 and exon −3 isoforms in adipose tissue had a higher HbA1c, than those expressing only the exon −3 isoform.
KeywordsMorbid obesity GH GH Receptor Metabolic syndrome Adipose tissue Exon 3 GHR
This study was funded by two institutional grants from Instituto Mexicano del Seguro Social: R-2013-3601-227 and R-2015-785-015.
Compliance with ethical standards
Conflict of interest
The authors declare that they have no conflict of interest.
All procedures involving human paricipants were in accordance to the ethical standards of the Institutional Research Committee and with the 1964 Helsinki Declaration and its later amendments.
Informed consent was obtained from all individual participants.
- 12.L. Audí, C. Esteban, A. Carrascosa, et al., Exon 3-deleted/full-length growth hormone receptor polymorphism genotype frequencies in Spanish short small-for-gestational-age (SGA) children and adolescents (n = 247) and in an adult control population (n = 289) show increased fl/fl in short SGA. J. Clin. Endocrinol. Metab. 91, 5038–5043 (2006)CrossRefPubMedGoogle Scholar
- 16.A.A. Jorge, F.G. Marchissotti, L.R. Montenegro, L.R. Carvalho, B.B. Mendonca, I.J. Arnhold, Growth hormone (GH) pharmacogenetics: influence of GH receptor exon 3 retention or deletion on first year growth response and final height in patients with severe GH deficiency. J. Clin. Endocrinol. Metab. 91, 1076–1080 (2006)CrossRefPubMedGoogle Scholar
- 17.L. Audi, A. Carrascosa, C. Esteban, M. Fernandez-Cancio, P. Andaluz, D. Yeste, R. Eespadero, M.L. Granada, H. Wollmann, L. Dryklund, The exón 3-deleted/full-length growth hormone receptor polymorphism does not influence the effect of puberty or growth hormone therapy on glcose homeostasis in short, non-growth hormone deficient small-for-gestationla-age children: Results from a two-year controlled prospective study. J. Clin. Endocrinol. Metab. 93, 2709–2715 (2008)CrossRefPubMedGoogle Scholar
- 18.W.F. Blum, K. Machinis, E.P. Shavrikova, A. Keller, H. Stobbe, R.W. Pfaefle, S. Amselem, The growth response to growth hormone (GH) treatment in children with isolated GH deficiency is independent of the exon-3 minus isoform of the GHR receptor. J. Clin. Endocrinol. Metab. 91, 4171–4174 (2006)CrossRefPubMedGoogle Scholar
- 19.M. Mormando, S. Chiloiro, A. Bianchi, A. Giampetro, F. Angelini, L. Tartaglione, L. Nasto, D. Milardi, A.M. Formenti, A. Giustina, L. De Marinis, Growth hormone receptor isoforms and fracture risk in adult-onset growth hormone deficient patients. Clin. Endocrinol. 85, 717–724 (2016)CrossRefGoogle Scholar