Biosynthesis of steroidal intermediates using Mycobacteria: a review / 生物工程学报

Steroids are a class of medicines with important physiological and pharmacological effects. In pharmaceutical industry, steroidal intermediates are mainly prepared through Mycobacteria transformation, and then modified chemically or enzymatically into advanced steroidal compounds. Compared with the "diosgenin-dienolone" route, Mycobacteria transformation has the advantages of abundant raw materials, cost-effective, short reaction route, high yield and environmental friendliness. Based on genomics and metabolomics, the key enzymes in the phytosterol degradation pathway of Mycobacteria and their catalytic mechanisms are further revealed, which makes it possible for Mycobacteria to be used as chassis cells. This review summarizes the progress in the discovery of steroid-converting enzymes from different species, the modification of Mycobacteria genes and the overexpression of heterologous genes, and the optimization and modification of Mycobacteria as chassis cells.

Identification of a new C-23 metabolite in sterol degradation of Mycobacterium neoaurum HGMS2 and analysis of its metabolic pathways / 生物工程学报

Mycobacterium neoaurum has the ability to produce steroidal intermediates known as 22-hydroxy-23, 24-bisnorchol-4-en-3-one (BA) upon the knockout of the genes for either the hydroxyacyl-CoA dehydrogenase (Hsd4A) or acyl-CoA thiolase (FadA5). In a previous study, we discovered a novel metabolite in the fermentation products when the fadA5 gene was deleted. This research aims to elucidate the metabolic pathway of this metabolite through structural identification, homologous sequence analysis of the fadA5 gene, phylogenetic tree analysis of M. neoaurum HGMS2, and gene knockout. Our findings revealed that the metabolite is a C23 metabolic intermediate, named 24-norchol-4-ene-3, 22-dione (designated as 3-OPD). It is formed when a thioesterase (TE) catalyzes the formation of a β-ketonic acid by removing CoA from the side chain of 3, 22-dioxo-25, 26-bisnorchol-4-ene-24-oyl CoA (22-O-BNC-CoA), followed by spontaneously undergoing decarboxylation. These results have the potential to contribute to the development of novel steroid intermediates.

Endocrine integration of fetal ovaries grafted under kidney capsule of unilaterally or bilaterally orchidectomized male hamster / Integración endocrina de ovarios fetales trasplantados bajo la cápsula renal de hámster machos uni o bilateralmente castrados

Mammalian ovary development undergoes important changes during the perinatal period, moment when follicles are assembled and start to develop in a process not well known, involving endocrine and paracrine factors. In order to investigate the effect of two different hormonal environments on the early development of the ovary, we used an autologous transplant model in which Syrian hamster fetal ovaries were grafted under the kidney capsule of males hosts previously unilaterally or bilaterally orchidectomized. After 35 days of graft, ovaries and kidney parenchyme of the host male did not present signs of rejection. Ovaries contained primordial, primary follicles, secondary follicles and few tertiary follicles with morphological features similar to ovaries of control females of 35 days of age. Healthy primary and secondary follicles of experimental groups had frequency distribution and size similar to control ovaries but tertiary follicles were scarce in control as well as in grafts where they were mainly atretic. PCNA, marker of proliferation, was immuno detected in granulosa cells of growing follicles and the marker of apoptosis, Caspase 3 active, was evident mainly in secondary follicles. Immunoreactivity for steroidogenic proteins, StAR, 3-bHSD and aromatase detected in the follicular wall cells and the decreased serum levels of FSH without important changes in testosterone in bilateral orchidectomized males that received ovarian graft, and testosterone decreased without changes in FSH levels in unilateral orchidectomized males (UO) with ovarian graft, all together suggest the effect of steroid hormones produced by the ovary. In conclusion, the experimental model of autologous transplant presents evidence of early ovary development under the kidney capsule and its functional integration to the endocrine axis of the host male.

El desarrollo del ovario en mamíferos sufre importantes cambios durante el periodo perinatal, momento en el cual los folículos se ensamblan y comienzan a desarrollarse en un proceso no muy dilucidado que involucra señales endocrinas y paracrinas. Con el objetivo de investigar el efecto de dos ambientes hormonales sobre el desarrollo temprano del ovario de hamster, usamos un modelo de trasplante autólogo en el que ovarios fetales fueron trasplantados bajo la cápsula renal de machos receptores previamente castrados y hemicastrados. Después de 35 días de trasplante, los ovarios y el parénquima renal de los machos receptores no presentaron señales de rechazo. El ovario presentó folículos primordiales, primarios, secundarios y algunos folículos terciarios con características morfológicas similares a los ovarios de hembras controles de 35 días de edad. Folículos primarios y secundarios sanos de ambos grupos experimentales se encontraron en frecuencia y tamaño similar al de ovarios controles, los folículos terciarios fueron escasos tanto en controles como en ovarios trasplantados, siendo en éstos principalmente atrésicos. PCNA, un marcador de proliferación celular, fue detectado por inmunohistoquímica en células granulosas de folículos en crecimiento, mientras que caspasa 3 activa, un marcador de apoptosis, fue evidente en folículos secundarios. Por otra parte, inmunoreactividad para proteínas esteroidogénicas, StAR, 3-bHSD y aromatasa, fue detectada en la pared folicular. Esta observación, junto a la disminución de niveles séricos de FSH, sin cambios importantes en los niveles de testosterona en machos castrados que recibieron trasplantes ováricos, y la disminución en los niveles de testosterona sin cambios en los niveles de FSH en machos hemicastrados con trasplantes ováricos, sugiere que el ovario no solo produce hormonas esteroidales sino que además éstas modifican los niveles hormonales del macho receptor del trasplante. En conclusión, este modelo de trasplante autólogo agrega información del desarrollo ovárico temprano cuando éste se desarrolla bajo la cápsula renal de machos entregando evidencia de la integración funcional del ovario trasplantado al eje endocrino de los machos receptores.

Regulation of luteinizing hormone receptor in hippocampal neurons following different long-lasting treatments of castrated adult rats.

The aim of this study was to investigate the effects of different Luteinizing hormone (LH) and steroid hormones levels on LH receptor (LHR) expression in the hippocampal cells. Rats (24 males and 24 females) were assigned to four groups: one control and three experimental [gonadectomy (GDX), gonadectomy + gonadotropin releasing hormone analogue (GDX+GnRHa) and GDX+GnRHa+estradiol (E2) or testosterone (T)] independently for each gender. All experimental rats were gonadectomized; then GnRHa was administrated to GDX+GnRHa group, and GnRHa plus steroid hormone to GDX+GnRHa+E2 or T group in both genders for four-month. LHR mRNA expression and its protein level in hippocampal cells were measured using QRT-PCR and Western blotting. Quantification of mRNA revealed a decrease in LHR transcripts level in GDX+GnRHa group of females. A significant change was observed between GDX groups and GDX+GnRHa+E2 or T versus GDX+GnRHa group in females. High levels of LH decreased significantly the immature isoform of LHR in GDX group compared to control group in both genders, but low LH concentrations in GDX+GnRHa group induced immature LHR isoform production only in females. Therefore increased LH concentration induces production of incomplete LHR transcripts in hippocampal cells and decreases immature LHR at the protein level. This implies that LH decreases the efficiency of translation through either producing non-functional LHR molecules or preventing their translation.

Endometrial receptivity to implantation in humans: biochemical and molecular aspects

The success rate of several advanced basic and clinical techniques in the field of mammalian biotechnology, including cloning, pre-implantation genetic diagnosis, and assisted reproductive techniques [ART] depends mainly on the success rate of pregnancy following in vitro fertilization-embryo transfer [IVF-ET]. The techniques used in ART have advanced considerably since the first in vitro fertilization birth in 1978. However, despite these advances, pregnancy rates are still relatively low and have not increased significantly in the last decade. Based on the facts that embryo implantation is considered as the last barrier in ART and that inadequate endometrial receptivity is responsible for approximately two-thirds of implantation failures, intensive research work has been performed to understand the physiology, regulation, and the clinical assessments of the endometrial receptivity to improve the success rate of IVF-ET. This and the ongoing reviews tend to cover the different aspects of the endometrial receptivity mainly in human model. The present part of this series primarily concerns with biochemical and molecular events in the endometrium coordinated within its receptivity period termed as the window of implantation. Successive sections will deal with its ultrastructural changes, biomarkers, clinical assessments and regulators of endometrium within the window of implantation

Cytosolic sulfotransferases.

Sulfoconjugation (Sulfation or Sulfonation) is an important reaction in the phase II biotransformation of a wide number of endogenous and foreign chemicals, including: drugs, toxic chemicals, hormones, and neurotransmitters. The reaction is catalyzed by the members of the cytosolic sulfotransferase (SULT) superfamily, consisting of ten functional genes in humans. Sulfation reaction in living cells is reversed by sulfatase, which hydrolyses the sulfonated conjugates. It has a major role in regulating the endocrine status of an individual by modulating the activity of steroid hormones, their biosynthesis, and the metabolism of catecholamines. Sulfonation is a key reaction in the body's 'chemical' defense against xenobiotics. Although the primary function of sulfoconjugation is to permit detoxification of the compound, it also results in the activation of chemical procarcinogens, such as certain dietary and environmental agents into carcinogens. In this review, we summarize our current understanding of the structure of mammalian cytosolic sulfotransferases and their role in human steroid associated cancers and in the bioactivation of chemical carcinogens.

Leydig cells, thyroid hormones and steroidogenesis.

Leydig cells are the primary source of androgens in the mammalian testis. It is established that the luteinizing hormone (LH) produced by the anterior pituitary is required to maintain the structure and function of the Leydig cells in the postnatal testis. Until recent years, a role by the thyroid hormones on Leydig cells was not documented. It is evident now that thyroid hormones perform many functions in Leydig cells. For the process of postnatal Leydig cell differentiation, thyroid hormones are crucial. Thyroid hormones acutely stimulate Leydig cell steroidogenesis. Thyroid hormones cause proliferation of the cytoplasmic organelle peroxisome and stimulate the production of steroidogenic acute regulatory protein (StAR) and StAR mRNA in Leydig cells; both peroxisomes and StAR are linked with the transport of cholesterol, the obligatory intermediate in steroid hormone biosynthesis, into mitochondria. The presence of thyroid hormone receptors in Leydig cells and other cell types of the Leydig lineage is an issue that needs to be fully addressed in future studies. As thyroid hormones regulate many functions of Sertoli cells and the Sertoli cells regulate certain functions of Leydig cells, effects of thyroid hormones on Leydig cells mediated via the Sertoli cells are also reviewed in this paper. Additionally, out of all cell types in the testis, the thyrotropin releasing hormone (TRH), TRH mRNA and TRH receptor are present exclusively in Leydig cells. However, whether Leydig cells have a regulatory role on the hypothalamo-pituitary-thyroid axis is currently unknown.

Effect of nifedipine and amlodipine on dead space wound healing in rats.

Effect of two calcium channel blockers (CCBs) nifedipine and amlodipine, was studied on normal and steroid depressed wound healing in albino rats, using the dead space wound model. The drugs enhanced normal healing as evidenced by increase in tensile strength of 10 days old granulation tissue. There was neither a significant change in the hydroxyproline level (or collagen) nor a change in the glycosaminoglycan content in granulation tissue. However, lysyloxidase level was increased significantly. The increase in tensile strength could thus be attributed to better cross-linking and maturation of collagen rather than collagen synthesis per se. The drugs were also able to overcome steroid depressed wound healing. It is likely that the prohealing effects may be related to the improved antioxidant status too, since superoxide dismutase levels were observed to be higher in the CCB- treated animals.

Secretion from neuropeptide-treated splenocytes modifies ovarian steroidogenesis

There are evidences for modulation of immune function by the sympathetic nervous system and its principal neurotransmitter norepinephrine (NE) throgugh superior ovarian nerve (SON)-coeliac ganglionnoradrenergic postganglionic innervation of the spleen. Seven days after SON transection at 53 days of age, the rat splenocytes were isolated and then cultured for 48h. These culture media, used to simulate ovaries from 60-day- old intact rats (neither SON-transected nor sham-operated) at diestrus 2 stage, in in vitro incubations, showed adecrease in progesterone release, an increase in estradiol release and no change in androstenedione release in relation to splenocyte culture media from control (sham-operated) rats.When esplenocytes from SON transected (SON-t) rats were treated with vasoactive intestinal peptide (VIP) or neuropeptide Y (NPY), both at 16-6M for 24h, their secretions increased the progesterone release while decreasing the estradiol release from the intact ovaries, compared with the secretions of untreated splenocytes from SON-t rats. Although the secretions of splenocytes treated with VIP decrease the androstenedione release from de ovaries, the treatment with NPY produced no change in hormone release. In the present paper the ovarian steroidogenic response, which was modified by the effects of an in vivo SON transection on spleen cells, was reverted by an in vitro system in which the splenocytes were treated with VIP or NPY. This could indicate that the spleen of SON-t rats does not receive those neuropeptides by neural route however, when they are added to splenocyte culture in vitro, the cell secretions revert the profile of steroid hormones released from the intact ovary. We also present functional evidence for modulation of the immune function by sympathetic nervous system and neurotransmitters other than NE.

Mecanismos moleculares de açäo hormonal / Molecular mechanisms of hormonal action

A característica principal dos hormônios é a sua habilidade em interagir com receptores altamente seletivos e ativar vias intracelulares do sinalizaçäo nos órgaos específicos. Após a interaçäo dos hormônios com seus receptores, uma seqüência de reaçöes pode levar ao aumento ou diminuiçäo na atividade de determinadas enzimas que, por sua vez, produzem a resposta fisiológica. Os hormônios säo bioquimicamente classificados em esteróides, peptídeos ou aminas e seus receptores diferem, basicamente, por sua localizaçäo, intra ou extracelular. No presente trabalho, o mecanismo molecular de açäo dos hormônios peptídicos (hidrofílicos) e esteróides (lipofílicos) é discutido.

Stress, steroids, and "ojas": neuroendocrine mechanisms and current promise of ancient approaches to disease prevention.

Recent research on causes of disease and aging has increasingly supported the importance of stress. One theory of the relationship between stress and disease is based on the concept of homeostasis, a term coined by Cannon over 50 years ago to signify those states and mechanisms responsible for the "staying power of the body". Bernard, Cannon, Selye and other leading researchers held that full, normal function of the self-regulating or homeostatic power of the body maintains the balanced, integrated condition we recognize as health. Failures in this capacity, such as those produced by frequent stressful experiences, can result in disease or death. Theories of health and disease surprisingly similar to this have existed since ancient times, and in widely different cultures. This review discusses both the fundamental elements of these theories and the current neuroendocrine research supporting their validity and immediate relevance. The connections between ancient and modern knowledge described herein were made possible largely by the work of Maharishi Mahesh Yogi, a scholar and teacher of the ancient vedic tradition of India. A key part of Ayurveda that has been obscure to modern science is the substance "ojas", which the classical texts say maintains balance of the physiology. In this article, specific steroids or steroid classes are proposed as likely candidates for both the "ordinary" and the "superior" types of ojas described in Ayurveda. Current evidence for the functions of these steroids, as well as their role in stress, disease and the maintenance of health, is reviewed. The knowledge of Ayurveda, as recently brought to light by Maharishi, includes methods for recovering and maintaining optimal function of steroidal systems. Such effects may help mediate the improvements in health and increased longevity attributed to Ayurveda and other ancient methods.

Alteraçöes do humor relacionadas às variaçöes hormonais: II. Síndrome pré-menstrual / Humor changes related to hormonal variations: II. Premenstrual syndrome

Os autores apresentam revisäo sobre o termo Síndrome Pré-Menstrual (SPM) e questöes relativas ao seu diagnóstico diferencial com outras patologias clínicas e distúrbios do humor. Correlacionam as ligaçöes entre açäo dos esteróides sexuais, opióides, prostaglandians e secotonina no cérebro e as alteraçöes do humor na SPM e sugerem de forma crítica manejo clínico da SPM.

Evaluation of levonogestrel action on the flank organ and the sebaceous gland lipogenesis of female hamsters

Se investigaron la función de la testerona y la acción del levonorgestrel sobre el órgano del flanco mediante medición de la lipogénesis de las glándulas sebáceas de hamsters hembras por incorporación metabólica de C-glucosa. Adémas, se obtuvo una caracterización parcial de la fracción lípida radiomarcada. Se evaluaron los efectos de la administración de esteroides in vivo mediante incorporación metabólica de C-U-glucosa en lípidos por los órganos del flanco del hamster hembra en condiciones de cultivo en presencia o en ausencia de LNG, T o ambos en el medio de incubación. Los lípidos radiactivos se identificaron mediante cromatografía de capa delgada. Levonorgesrel, aisladamente o en conjunto con testosterona, disminuyó el peso y el contenido de sebo de los órganos del flanco en el hamster hembra cuando se efectuaron comparaciones con los resultados del tratamiento con T nada más. Cuando se administró T en condiciones de cultivo se Observó un incremento rápido y significativo de la glucosa radiomarcada. En contraste, cuando estaba presente LNG en el medio de incubación, no se observaron diferencias en la incorporación de C-U-glucosa cuando se efectuaron comparaciones con sus controles. Cuando se añadieron T + LNG, se observaron resultados similares a los obtenidos cuando se empleó LNG nada más. La testosterona incrementó las concentraciones de glicéridos y ácidos grados libres, pero disminuyó las de lípidos polares; en contraste, el LNG careciïde efecto sobre las proporciones relativas de incorporación de C-U-glucosa en las diferentes clases de lípidos cuando se efectuaron comparaciones con sus controles. Los resultados indicaron qu el LNG abole el efecto de incremento de la incorporación de C glucosa producido por T y cambia la composición de los lípidos inducida en los órganos del flanco del hamster hembra

Efecto de las gonodotropinas sobre la esteroidogenesis de células de granulosa de ratas inmaduras en condiciones de cultivo / Effects of gonadotropins on steroidogeneis of cultured granulosa cells from inmature rats

Se evaluó la acción de diferentes efectores sobre la actividad esteroidogénica de células de granulosa procedentes de ratas inmaduras en condiciones de cultivo. Se encontró que las células son capaces de responder a la hormona estimulante del folículo con un incremento en la secreción de estradiol dependiente de la concentración de gonadotropina y del tiempo de incubación. La expresión de este efecto requirió de la presencia de androstenediona. Las células tambien aumentaron la secreción de esteroides en presencia de gonadotropina coriónica y de análogos del adenosín 3(1),5(1) monofostato cíclico. Los resultados sugieren que este sistema de cultivo podría evaluar los moduladores potenciales de la actividad esterogénica de las células de granulosa

Acute administration of human chorionic gonadotropin reverts some of the inhibitory effects of an LH-RH agonist on testicular steroidogenesis

An LH-RH agonist, des-Gly10, [DTrp6]-LH-RH ethylamide (LH-RH A), was administered chronically to adult male cats in order to determine its effect on the steroidogenesis of the testis during the stimulatory action of human chorionic gonadotropin (hCG). Measurement of plasma testosterone levels were combined with the histochemical analysis of some steps of the testicular steroidogenic pathway. Chronic daily treatment with LH-RH A(20 *g/kg) for 67 days inhibited the early testicular response to hCG during the initial 0.5,1 and 24 h, whereas the inhibitory egffect was not observed 48 and 72 h after hCG administration.The maximal responses to hCG were obtained both in LH-RH A-treated animals and in their control group 48 and 72 h after hCG adnministration. Under these conditions, LH-RH A-treated cats showed no alteration in 3ß-hydroxysteroid dehydrogenase (3ß-Host-D) activity, whereas a marked inhibition was observed in the activity of alcohol dehydrogenase (ADII) which reflects the activity of 20,22-desmolase and/or 17,20-desmolase.

Técnica de incubaçäo do estroma do ovário / Technique of ovarian stroma incubation

O tecido estonal ovariano fresco foi incubado numa soluçäo de Krebs-Ringer fosfato, com precursores conhecidos, durante quatro horas. A síntese foi interrompida com acetona e o precipitado removido por filtraçäo. O meio de incubaçäo extraído com éter etílico foi filtrado e secado. O tecido seco foi levantado em metanol 90% e particionado com éter sulfúrico. Depois da evaporaçäo, o resíduo seco foi dissolvido em hexano, filtrado em algodäo de vidro e posto para secar. o resíduo foi levantado em tolueno e particionado com NaOH, 1N. A porçäo de tolueno contendo os esteróides neutros (androgênios) foi decada. O ph da fraçäo de NaOH, contendo os esteróides fenólicos (estrogênios), foi ajustado para 8,0 e entäo esta fraçäo foi extraída com éter etílico; o seu pH ajustado para 2,0 e ela foi posta para secar. Ambas as fraçioes, neutra e fenólica, foram levantadas em etanol e submetidas a cromatografia em papel com padröes. Depois de sua identificaçäo nos cromatogramas por reaçöes de cor específicas, os esteróides foram quantificados por colorimetria, com índice de sensibilidade de 0,40 x 10-3 mg/g de tecido incubado