Sertoli-secreted FGF-2 induces PFKFB4 isozyme expression in mouse spermatogenic cells by activation of the MEK/ERK/CREB pathway

Abstract

In this study, we investigated how the hormonal regulation of spermatogenesis modulates 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB) isozyme expression in two mouse spermatogenic cell lines, GC-1 spg and GC-2 spd (ts). For this purpose, TM4 Sertoli cells were used to obtain conditioned medium that was treated or not with dihydrotestosterone for 2 days [dihydrotestosterone conditioned medium (TCM) and basal conditioned medium (BCM), respectively]. We observed an increase in the expression of PFKFB4 along with a decrease in PFKFB3 in spermatogenic cell lines treated with TCM. These effects were inhibited by the antiandrogen drug flutamide and by heat-inactivated TCM, indicating the protein nature of the TCM mediator and its dependence on Sertoli cell stimulation by dihydrotestosterone. In addition, adult rat testes treated with the GnRH antagonist Degarelix exhibited a reduction in the expression of PFKFB4 in germ cells. Addition of exogenous FGF-2 mimicked the changes in the Pfkfb gene expression, whereas neutralizing antibodies against FGF-2 abolished them. Interestingly, similar effects on Pfkfb gene expression were observed using different MAPK inhibitors (U-0126, PD-98059, and H-89). Luciferase analysis of Pfkfb4 promoter constructs demonstrated that a putative CRE-binding sequence located at Ϫ1,463 relative to the transcription start site is required to control Pfkfb4 gene expression after TCM treatment. Pulldown assays showed the binding of the CREB transcription factor to this site. Altogether, these results show how the paracrine regulation orchestrated by Sertoli cells in response to testosterone controls glycolysis in germ cells.fibroblast growth factor; 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase; mitogen-activated protein kinase kinase; extracellular signal-regulated kinase; cAMP response element-binding protein; fructose-2,6-bisphosphate; glycolysis; spermatogenesis; sperm production

Fructose 2,6-Bisphosphate in Cancer Cell Metabolism

“…Several splice variants have been reported, with the PFK-2 core domain being conserved among all of them ( 162 , 164 ). The PFKFB4 gene encodes an isoenzyme that is expressed in the testis under the regulation of testosterone ( 165 , 166 ). Moreover, it has been demonstrated that PFKFB4 mRNA and protein levels are regulated by hypoxia and glucose levels in different cancer cell lines from the prostate, liver, colon, bladder, stomach and pancreas ( 86 , 87 , 167 – 171 ).…”

Differential expression of miR-23a/b-3p and its target genes in male patients with subfertility

“…In total, 115 men who presented themselves to an infertility clinic were included in this study, as described below. A total of 66 men were recruited into the study (mean age AE SD, 25.09 AE 3.84 year; range, [20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], including 33 subfertile (oligoasthenozoospermia) men who attended the IVF lab for infertility treatment and 33 age-matched donor men with normal semen parameters (normozoospermia), and were analyzed by reverse transcription quantitative polymerase chain reaction (RT-qPCR).…”

Silibinin declines blue light-induced apoptosis and inflammation through MEK/ERK/CREB of retinal ganglion cells

“…In addition, some studies demonstrated that neuroprotective function increases the Bcl-2 level to an anti-apoptotic state and activates autophagy through the induction of silibinin through the Notch pathway [24]. ERK and NF-rB pathways are known to alter the expression of pro-apoptotic and antiapoptotic genes such as Bax and Bcl-2 by regulating the activity of transcription factors including CREB [25,26]. Therefore, MEK/ERK/CREB pathway is considered to play a critical role in apoptosis, but the regulation effect of silibinin on the MEK/ERK/CREB pathway remains unclear.…”