Differential effects of androgens and estrogens over cellular GH sensitivity in HEPG2 cells

Copyright © 2021 Elsevier Ltd. All rights reserved..

Testosterone and estrogen concentrations progressively increase during puberty, and in association with growth hormone (GH), lead to the increase in height velocity known as the pubertal growth spurt. Very limited information is available however, regarding the possible effects of sex steroids over GH cellular sensitivity.

OBJECTIVE: To investigate the effects of different concentrations of testosterone, estradiol and dihydrotestosterone over the GH intracellular signaling pathway.

METHODS: We evaluated the effects of these sex steroids on the nuclear phosphorylation of STAT5b and IGF-1 expression, in HEPG2 human hepatoma cells. In addition, we studied whether Tamoxifen (TAM), can modulate these effects.

RESULTS: The highest concentration of T tested (10 ng/mL) co-incubated with a fixed concentration of GH (40 ng/mL) increased nuclear STAT5b phosphorylation compared with GH alone (1.34 ± 0.2 vs 0.6 ± 0.09 AU; *p < 0.05), as well as IGF-1 expression (0.6 ± 0.03 vs 0.32 ± 0.05 AU; *p < 0.05). This effect was not observed with lower concentrations of T tested (1 and 5 ng/mL). A similar increase in nuclear STAT5b phosphorylation was observed with the lowest concentration of E2 tested (20 pg/mL), co-incubated with the same fixed concentration of GH (3.6 ± 0.5 vs 1.28 ± 0.33 AU; *p < 0.05). This effect was also associated with an increase in IGF-1 expression (0.73 ± 0.02 vs 0.39 ± 0.04 AU; *p < 0.05). These results were not observed with higher concentrations of E2 tested (75 and 200 pg/mL). DHT at concentrations of 0.1, 0.25 and 0.5 ng/mL, co-stimulated with GH, did not change cytoplasmic STAT5b phosphorylation, nuclear STAT5b or IGF-1 expression. In addition, the co-incubation of TAM with the highest concentration of T tested (10 ng/mL) and GH (40 ng/mL) did not change cytoplasmic, nuclear pSTAT5 levels or IGF-1 expression.

CONCLUSIONS: T and E2 potentiate the GH signaling pathway in a concentration-dependent fashion. The observation that the non-aromatizable androgen dihydrotestosterone does not stimulate this pathway, and that the effects of T are blocked with TAM, suggests that the effects of T over the GH signaling pathway appear to be mediated by estrogen.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:57-58

Enthalten in:

Growth hormone & IGF research : official journal of the Growth Hormone Research Society and the International IGF Research Society - 57-58(2021) vom: 15. Apr., Seite 101390

Sprache:

Englisch

Beteiligte Personen:

Ocaranza, Paula [VerfasserIn]
Íñiguez, Germán [VerfasserIn]
Johnson, M Cecilia [VerfasserIn]
Cassorla, Fernando [VerfasserIn]

Links:

Volltext

Themen:

08J2K08A3Y
094ZI81Y45
12629-01-5
3XMK78S47O
4TI98Z838E
67763-96-6
Androgens
Aromatase
Dihydrotestosterone
EC 1.14.14.1
Estradiol
Estrogen Antagonists
Estrogens
GH signal transduction
Human Growth Hormone
Insulin-Like Growth Factor I
Journal Article
Receptors, Estrogen
Receptors, Somatotropin
Research Support, Non-U.S. Gov't
STAT5 Transcription Factor
STAT5B protein, human
Tamoxifen
Testosterone

Anmerkungen:

Date Completed 09.02.2022

Date Revised 09.02.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.ghir.2021.101390

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM325267308