Characterization of human adrenal cytochrome P450 11B2 products of progesterone and androstenedione oxidation

Recent developments in the enzymatic modifications of steroid scaffolds

Steroids are an important family of bioactive compounds. Steroid drugs are renowned for their multifaceted pharmacological activities and are the second-largest category in the global pharmaceutical market. Recent developments in biocatalysis and biosynthesis have led to the increased use of enzymes to enhance the selectivity, efficiency, and sustainability for diverse modifications of steroids. This review discusses the advancements achieved over the past five years in the enzymatic modifications of steroid scaffolds, focusing on enzymatic hydroxylation, reduction, dehydrogenation, cascade reactions, and other modifications for future research on the synthesis of novel steroid compounds and related drugs, and new therapeutic possibilities.

Investigating the biosynthesis and metabolism of 11β-hydroxyandrostenedione

The "rediscovery" 11β-hydroxyandrostenedione (11OHA4) placed the spotlight on this unique adrenal-derived hormone with researchers and clinicians once again focusing on the steroid's presence in endocrine pathology. Little was known about the steroid other than its chemical characterisation and that a mitochondrial cytochrome P450 enzyme catalysed the 11β-hydroxylation of 11OHA4. The fact that neither the biosynthesis nor metabolism of 11OHA4 had been fully characterised presented an ideal opportunity to investigate the metabolic pathways. In addition, methodologies and analytical tools have improved vastly since 11OHA4 was first identified in the 1950s. Cell models, recombinant DNA technology and steroid quantification using liquid chromatography mass spectrometry have greatly facilitated investigations in the field of steroidogenesis. Evident from the structure is that 11OHA4 can be metabolised by hydroxysteroid dehydrogenases and reductases acting on the C4/C5 double bond and on functional moieties at specific carbons on the cyclopentane-perhydro-phenanthrene backbone of the steroid. In this chapter, the biosynthesis and metabolism of 11OHA4 is followed using two strategies that complement each another; (i) human cell models either transiently transfected with recombinant DNA or expressing endogenous steroidogenic enzymes and (ii) steroid identification and quantification using high resolution mass spectrometry. These methodologies have proven invaluable in the determination of 11OHA4's metabolic route. Both strategies are presented with the focus on the accurate identification and quantification of steroids using UHPLC-MS/MS and UPC2-MS/MS. The protocols described in this chapter lay a sound foundation which can aid the researcher and be adapted and implement in future studies.

The Role of Cytochrome P450 Enzymes in COVID-19 Pathogenesis and Therapy

Coronavirus disease 2019 (COVID-19) has become a new public health crisis threatening the world. Dysregulated immune responses are the most striking pathophysiological features of patients with severe COVID-19, which can result in multiple-organ failure and death. The cytochrome P450 (CYP) system is the most important drug metabolizing enzyme family, which plays a significant role in the metabolism of endogenous or exogenous substances. Endogenous CYPs participate in the biosynthesis or catabolism of endogenous substances, including steroids, vitamins, eicosanoids, and fatty acids, whilst xenobiotic CYPs are associated with the metabolism of environmental toxins, drugs, and carcinogens. CYP expression and activity are greatly affected by immune response. However, changes in CYP expression and/or function in COVID-19 and their impact on COVID-19 pathophysiology and the metabolism of therapeutic agents in COVID-19, remain unclear. In this analysis, we review current evidence predominantly in the following areas: firstly, the possible changes in CYP expression and/or function in COVID-19; secondly, the effects of CYPs on the metabolism of arachidonic acid, vitamins, and steroid hormones in COVID-19; and thirdly, the effects of CYPs on the metabolism of therapeutic COVID-19 drugs.

Back where it belongs: 11β-hydroxyandrostenedione compels the re-assessment of C11-oxy androgens in steroidogenesis

Adrenal steroidogenesis has, for decades, been depicted as three biosynthesis pathways -the mineralocorticoid, glucocorticoid and androgen pathways with aldosterone, cortisol and androstenedione as the respective end products. 11β-hydroxyandrostenedione was not included as an adrenal steroid despite the adrenal output of this steroid being twice that of androstenedione. While it is the end of the line for aldosterone and cortisol, as it is in these forms that they exhibit their most potent receptor activities prior to inactivation and conjugation, 11β-hydroxyandrostenedione is another matter entirely. The steroid, which is weakly androgenic, has its own designated pathway yielding 11-ketoandrostenedione, 11β-hydroxytestosterone and the potent androgens, 11-ketotestosterone and 11-ketodihydrotestosterone, primarily in the periphery. Over the last decade, these C11-oxy C₁₉ steroids have once again come to the fore with the rising number of studies contradicting the generally accepted notion that testosterone and it's 5α-reduced product, dihydrotestosterone, are the principal potent androgens in humans. These C11-oxy androgens have been shown to contribute to the androgen milieu in adrenal disorders associated with androgen excess and in androgen dependant disease progression. In this review, we will highlight these overlooked C11-oxy C₁₉ steroids as well as the C11-oxy C₂₁ steroids and their contribution to congenital adrenal hyperplasia, polycystic ovarian syndrome and prostate cancer. The focus is on new findings over the past decade which are slowly but surely reshaping our current outlook on human sex steroid biology.

Antifungal therapy with azoles and the syndrome of acquired mineralocorticoid excess

The syndromes of mineralocorticoid excess describe a heterogeneous group of clinical manifestations leading to endocrine hypertension, typically either through direct activation of mineralocorticoid receptors or indirectly by impaired pre-receptor enzymatic regulation or through disturbed renal sodium homeostasis. The phenotypes of these disorders can be caused by inherited gene variants and somatic mutations or may be acquired upon exposures to exogenous substances. Regarding the latter, the symptoms of an acquired mineralocorticoid excess have been reported during treatment with azole antifungal drugs. The current review describes the occurrence of mineralocorticoid excess particularly during the therapy with posaconazole and itraconazole, addresses the underlying mechanisms as well as inter- and intra-individual differences, and proposes a therapeutic drug monitoring strategy for these two azole antifungals. Moreover, other therapeutically used azole antifungals and ongoing efforts to avoid adverse mineralocorticoid effects of azole compounds are shortly discussed.