Endocrine Abstracts

Recent results from us and others have shown that concentrations of sex steroids in serum/circulation do not always reflect their intra-tissue levels in hormone-dependent tissues. This proposes that sex steroid metabolism plays a key role in determining the final concentration of active sex steroids in their target tissues. According to the current knowledge, members of three enzyme families, namely cytochrome P450 (CYP), aldo-keto reductase (AKR) and short-chain dehydrogenase...

Recent data from us and others have evidently shown that steroid metabolism at the target tissues is a key determinant regulating the availability of high affinity ligands for steroid receptors. Thus, the serum concentrations of the steroids do not necessary mimic their target tissue concentrations in several physiological and pathophysiological settings. Accordingly, among the other steroid metabolizing enzymes, the expression of hydroxysteroid dehydrogenase- (HSD17B) enzymes...

Mice have been used as a model system in biomedicine for several decades. As mammals their relevance to human endocrinology is substantially greater than many other model systems such as flies, worms and yeast. Mice are also easily adapted to various experimental conditions with human relevance. Most importantly, the mouse genome is well annotated, it can be precisely engineered by several powerful ways, and international consortia have recently produced variety novel tools fo...

Epididymis is an androgen dependent organ with four main segments; initial segment (IS), caput, corpus and cauda. It is an essential site for post-testicular sperm maturation, as spermatozoa acquire fertilizing capacity during epididymal transit. Post-testicular maturation is dependent on the proteins expressed and secreted to the lumen by epididymal cells. Androgens regulate gene expression in epididymis in a segment-specific manner. Caput-specific genes are androgen regulate...

Recent findings revealed 3,5-diiodo-L-thyronine (3,5-T2) as a metabolically active iodothyronine affecting hepatic energy and lipid metabolism. Therefore, 3,5-T2 has been proposed as a potential hypolipidemic agent for treatment of obesity and its hepatic aftermath. So far only limited data exists relating to the effects of 3,5-T2 on metabolism in euthyroid mammals maintained on high-fat diet from the day of weaning onwards. Therefore, we performed a study in wh...

: Hydroxysteroid (17beta) dehydrogenase 1 (Hsd17b1) is a steroidogenic enzyme catalyzing the conversion of estrone (E1) to estradiol (E2), and androstenedione (A-dione) to testosterone (T). We have shown that the deletion of Hsd17b1 gene in mice resulted in the failure of ovarian estrogen production and subfertility. In this study, we clarified the role of Hsd17b1 in male reproduction. The data revealed that in mice Hsd17b1 mRNA is highly expressed in the Sertoli cells at the ...

Hydroxysteroid 17-beta dehydrogenase 1 (HSD17B1) is an enzyme catalyzing the reduction of estrone (E1) to estradiol (E2), as well as androstenedione (Adione) to testosterone (T). To elucidate the physiological function of HSD17B1, we generated knockout mice with disrupted Hsd17b1 gene using targeted ES cells (clone 10231) obtained from KOMP repository (www.komp.org). In these ES cells the whole coding region of Hsd17b1 was replaced with LacZ/Neo cass...

The androgen receptor (AR) signaling pathway is central to the emergence of castration-resistant prostate cancer (CRPC). miR-32 is an androgen regulated miRNA which is differentially expressed in CRPC compared to benign prostatic hyperplasia (BPH) and able to provide a significant growth advantage to LNCaP cells. To study how increased miR-32 expression contributes to prostate cancer formation and/or progression in vivo, we have established transgenic mice expressing ...

Spermatozoa are dependent on the proximal epididymis environment to complete their maturation. However, no single specific factor crucial for this process has been identified. Rnase9 and Rnase10 are expressed specifically in the murine proximal epididymis. Located on chromosome 14C1 only 28 kb apart, they do not show high homology with each other. An orthologue of both genes exist in the rat and human, and ‘Train A’ (porcine orthologue) is the most abun...

Hypersecretion of hCG in transgenic mice produces profound alterations in the ovary, thus triggering failures in ovulation and affecting fertility. The objective of this study was to analyze the response of immature female mice overexpressing moderated (hCGβ+; 0.1 IU/ml) and elevated (hCGαβ+; 7 IU/ml) levels of hCG to an ovulation induction protocol (PMSG 7.5 IU i.p.; after 48 h, hCG 7.5 IU i.p). Wild-type (WT) females subjected to the same protocol were used as...