Steroid biosynthesis

About: Steroid biosynthesis is a research topic. Over the lifetime, 1721 publications have been published within this topic receiving 58977 citations.

Monoclonal antibodies against rat adrenocortical cell antigens.

Abstract: Cell lines secreting antibodies directed against rat adrenocortical cell antigens have been produced using hybridoma techniques. As tested by immunofluorescent staining, eleven of these antibodies were specific for rat adrenocortical cells in that they did not interact with rat adrenal medulla, liver, muscle, ovary or kidney cells. Two of these antibodies were studied in greater detail. One interacted with an antigen present only in adrenal fasciculata and reticularis cells (inner zone antibody, IZA). The expression of the antigen with which this antibody interacted was increased by in vivo treatment with ACTH. The other antibody interacted with an antigen present in all three adrenocortical cell types (adrenocortical antibody ACA). Expression of this antigen was unaffected by ACTH treatment. The effect of both antibodies on steroid biosynthesis by mitochondrial and microsomal preparations of zona glomerulosa and inner zone tissue was tested. For these experiments, the antibodies were purified from culture media by Protein-A-Sepharose affinity chromatography. ACA had no effect on steroidogenesis by any preparation. IZA specifically decreased the production of 18-hydroxydeoxycorticosterone from deoxycorticosterone by the inner zone microsomal and mitochondrial fraction. The results suggest that the IZA antigen is found predominantly in the rat adrenal inner zone and that the antibody may be useful in monitoring adrenocortical zonation. In addition, the antigen would appear to have a functional role in steroid metabolism.

Identification of two novel ACTH-responsive genes encoding manganese-dependent superoxide dismutase (SOD2) and the zinc finger protein TIS11b [tetradecanoyl phorbol acetate (TPA)-inducible sequence 11b].

Abstract: ACTH is the major trophic factor regulating and maintaining adrenocortical function, affecting such diverse processes as steroidogenesis, cell proliferation, cell migration, and cell survival We used differential display RT-PCR to identify genes that are rapidly induced by ACTH in the bovine adrenal cortex Of 42 PCR products differentially amplified from primary cultures of bovine adrenocortical cells treated with 10 nM ACTH, six identified mRNAs that were confirmed by Northern blot analysis to be induced by ACTH Four of these amplicons encoded noninformative repetitive sequences Of the other two sequenced amplicons, one encoded a partial sequence for mitochondrial manganese-dependent superoxide dismutase (SOD2), an enzyme that is likely to protect adrenocortical cells from the cytotoxic effects of radical oxygen species generated during steroid biosynthesis The second was identified as TIS11b (phorbol-12-myristate-13-acetate-inducible sequence 11b)/ERF-1/cMG, a member of the CCCH double-zinc finger protein family SOD2 induction by ACTH was independent of extracellular steroid concentration or oxidative stress SOD2 and TIS11b mRNA expressions were rapidly induced by ACTH, reaching a maximal level after 8 h and 3 h of treatment, respectively These ACTH effects were mimicked by forskolin but appeared independent of cortisol secretion Upon ACTH treatment, induction of TIS11b expression closely followed the previously characterized peak of vascular endothelial growth factor (VEGF) expression Transfection of a TIS11b expression plasmid into 3T3 fibroblasts induced a decrease in the expression of a reporter gene placed upstream of the VEGF 3'-untranslated region, indicating that TIS11b may be an important regulator of VEGF expression through interaction with its 3'-untranslated region

Dynamic transcriptome and DNA methylome analyses on longissimus dorsi to identify genes underlying intramuscular fat content in pigs

Abstract: The intramuscular fat content (IMF) refers to the amount of fat within muscles, including the sum of phospholipids mainly found in cell membranes, triglycerides and cholesterol, and is determined both by hyperplasia and hypertrophy of adipocyte during the development of pigs. The IMF content is an important economic trait that is genetically controlled by multiple genes. The Laiwu pig is an indigenous fatty pig breed distributed in North China, characterized by excessively higher level of IMF content (9%~12%), therefore, is suitable for the identification of genes controlling IMF variations. To identify genes underlying IMF deposition, we performed genome-wide transcriptome and methylome analyses on longissimus dorsi (LD) muscle in Laiwu pigs across four developmental stages. A total of 22,524 expressed genes were detected and 1158 differentially expressed genes (DEGs) were hierarchically clustered in the LD muscle over four developmental stages from 60 d to 400 d. These genes were significantly clustered into four temporal expression profiles, and genes participating in fat cell differentiation and lipid biosynthesis processes were identified. From 120 d to 240 d, the period with the maximum IMF deposition rate, the lipid biosynthesis related genes (FOSL1, FAM213B and G0S2), transcription factors (TFs) (EGR1, KLF5, SREBF2, TP53 and TWIST1) and enriched pathways (steroid biosynthesis and fatty acid biosynthesis) were revealed; and fat biosynthesis relevant genes showing differences in DNA methylation in gene body or intergenic region were detected, such as FASN, PVALB, ID2, SH3PXD2B and EGR1. This study provides a comprehensive landscape of transcriptome of the LD muscle in Laiwu pigs ranging from 60 to 400 days old, and methylome of the LD muscle in 120 d and 240 d Laiwu pigs. A set of candidate genes and TFs involved in fat biosynthesis process were identified, which were probably responsible for IMF deposition. The results from this study would provide a reference for the identification of genes controlling IMF variation, and for exploring molecular mechanisms underlying IMF deposition in pigs.