Steroid biosynthesis

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

Genetics of the mineralocorticoid system in primary hypertension.

Abstract: Abnormalities in steroid biosynthesis have been known for years to cause hypertension in some cases of congenital adrenal hyperplasia. In these patients hypertension usually accompanies a characteristic phenotype with abnormal sexual differentiation. Recently, the molecular basis of four forms of severe hypertension transmitted on an autosomal basis but without additional phenotypic features has been elucidated. All these conditions are characterized primarily by low plasma renin, normal or low serum potassium, and salt-sensitive hypertension, indicating an increased mineralocorticoid effect. These four disorders, the glucocorticoid remediable aldosteronism, the syndrome of apparent mineralocorticoid excess, the activating mutation of the mineralocorticoid receptor, and the Liddle syndrome are a consequence of either abnormal biosynthesis, metabolism, or action of steroid hormones, and are ultimately characterized by an overactivation of the epithelial sodium channel in distal renal tubules. Hyperactivity of this channel results in increased sodium reabsorption and volume expansion leading to an increase in blood pressure as well as potassium loss. With the advent of molecular biology in clinical practice, it has become evident that some genetic defect may present with a more discrete phenotype, with only moderate hypertension with or without hypokalemia as the sole feature. A search for genetic disorders of the mineralocorticoid axis should be an integral part of the diagnostic work-up, particularly in young adults with hypertension.

On the histogenesis of the ovarian interstitial gland in rabbits. I. Primary interstitial gland.

Abstract: Ovaries from rabbits one to three months old were examined to demonstrate the histogenesis of ovarian interstitial cells. Electron micrographs showed that “primary interstitial gland cells” with abundant agranular endoplasmic reticulum were present prior to appearance of follicular atresia and that extensive development of the agranular endoplasmic reticulum and accumulation of lipid droplets occurred in the epithelial cells of medullary cords and granulosal cell nests. Therefore, it was concluded that the “primary interstitial gland” of juvenile rabbit ovaries is of epithelial origin, derived from the medullary cords and the granulosal nests, although the “secondary interstitial gland” is considered to arise from the theca interna of atretic follicles. This conclusion was confirmed by biochemical and histochemical demonstration of 3β-hydroxysteroid dehydrogenase, an enzyme system necessary for steroid biosynthesis. The activity of 3β-hydroxysteroid dehydrogenase increased significantly at two months when the agranular reticulum began to devlop in epithelial cells. Histochemical findings showed that the cells having the enzyme activity were consistent with the cells containing a large quantity of lipid.

Enteric lactoferrin attenuates the development of high-fat and high-cholesterol diet-induced hypercholesterolemia and atherosclerosis in Microminipigs

Abstract: Previously, we found that enteric lactoferrin (eLF) could reduce the visceral fat accumulation known to associate strongly with metabolic syndrome symptoms and consequently with an increased risk of atherosclerosis. In this study, the atherosclerosis-preventive potential of LF was assessed in a high-fat and high-cholesterol diet (HFCD)-induced hypercholesterolemia and atherosclerosis model using Microminipig™. Eight-week orally administered eLF remarkably reduced the HFCD-induced serum total and low-density lipoprotein cholesterol levels but not high-density lipoprotein cholesterol levels. A histological analysis of 15 arteries revealed that eLF systemically inhibited the development of atherosclerotic lesions. Pathway analysis using identified genes that characterized eLF administration in liver revealed significant changes in the steroid biosynthesis pathway (ssc00100) and all affected genes in this pathway were upregulated, suggesting that cholesterol synthesis inhibited by HFCD was recovered by eLF. In summary, eLF could potentially prevent the hypercholesterolemia and atherosclerosis through protecting homeostasis from HFCD-induced dysfunction of cholesterol metabolism.

Membrane disruption of Fusarium oxysporum f. sp. niveum induced by myriocin from Bacillus amyloliquefaciens LZN01.

Abstract: Myriocin, which is produced by Bacillus amyloliquefaciens LZN01, can inhibit the growth of Fusarium oxysporum f. sp. niveum (Fon). In the present study, the antifungal mechanism of myriocin against Fon was investigated with a focus on the effects of myriocin on the cell membrane. Myriocin decreased the membrane fluidity and destroyed the membrane integrity of Fon. Significant microscopic morphological changes, including conidial shrinkage, the appearance of larger vacuoles and inhomogeneity of electron density, were observed in myriocin-treated cells. A membrane-targeted mechanism of action was also supported by transcriptomic and proteomic analyses; a total of 560 common differentially expressed genes (DEGs) and 285 common differentially expressed proteins (DEPs) were identified. The DEGs were further verified by using RT-qPCR. The combined analysis between the transcriptome and proteome revealed that the expression of some membrane-related genes and proteins, mainly those related to sphingolipid metabolism, glycerophospholipid metabolism, steroid biosynthesis, ABC transporters and protein processing in the endoplasmic reticulum, was disordered. Myriocin affected the serine palmitoyl transferase (SPT) activity as evidenced through molecular docking. Our results indicate that myriocin has significant antifungal activity owing to its ability to induce membrane damage in Fon.

Comparative Metabolomic and Proteomic Analyses Reveal the Regulation Mechanism Underlying MeJA-Induced Bioactive Compound Accumulation in Cutleaf Groundcherry (Physalis angulata L.) Hairy Roots

Abstract: Cutleaf groundcherry (Physalis angulata L.) is an annual plant with a number of medicinal ingredients. However, studies about the secondary metabolism of P. angulata are very limited. An integrated metabolome and proteome approach was used to reveal the variations in the metabolism associated with bioactive compounds under methyl-jasmonate (MeJA) treatment. Application of MeJA to the hairy roots could significantly increase the accumulation of most active ingredients. A targeted approach confirmed the variations in physalins D and H between MeJA treatment and the controls. Increases in the levels of a number of terpenoid backbone biosynthesis and steroid biosynthesis related enzymes, cytochrome P450 monooxygenases and 3β-hydroxysterioid dehydrogenase might provide a potential explanation for the MeJA-induced active ingredient synthesis. Our results may contribute to a deeper understanding of the regulation mechanism underlying the MeJA-induced active compound accumulation in P. angulata.