Anabolic utilization of steroid hormones in Helicobacter pylori

In this study, we have demonstrated that Helicobacter pylori absorbs a steroid prehormone (pregnenolone) and two androgens (dehydroepiandrosterone and epiandrosterone), glucosylates these steroids, and utilizes glucosyl-steroid hormone compounds as the membrane lipid components. The only common structure among the steroid prehormone and the two androgens is a 3β-OH in the steroid framework. Our results indicate that the 3β-OH in the steroid hormones is a crucial conformation required for steroid glucosylation by H. pylori . In addition, we found that H. pylori absorbs and holds estrogens possessing 3-OH (estrone and estradiol) into the membrane. The effective absorption of estrogen into the membrane appeared to be controlled by the number of hydroxyl groups modifying the steroid framework. In contrast, H. pylori induced neither membrane absorption nor glucosylation of the other steroid hormones possessing 3=O (progesterone, androstenedione and testosterone) or 3α-OH (androsterone). These results indicate that H. pylori selectively absorbs 3β-OH and 3-OH steroid hormones, and utilizes only 3β-OH steroid hormones as the materials for glucosylation.     

Direct binding and activation of protein kinase C isoforms by steroid hormones

The non-genomic action of steroid hormones regulates a wide variety of cellular responses including regulation of ion transport, cell proliferation, migration, death and differentiation. In order to achieve such plethora of effects steroid hormones utilize nearly all known signal transduction pathways. One of the key signalling molecules regulating the non-genomic action of steroid hormones is protein kinase C (PKC). It is thought that rapid action of steroids hormones results from the activation of plasma membrane receptors; however, their molecular identity remains elusive. In recent years, an increasing number of studies have pointed at the selective binding and activation of specific PKC isoforms by steroid hormones. This has led to the hypothesis that PKC could act as a receptor as well as a transducer of the non-genomic effects of these hormones. In this review we summarize the current knowledge of the direct binding and activation of PKC by steroid hormones.     

Old experiments and new trends in avian sex differentiation

Summary The influence of steroid hormones on sex differentiation was first demonstrated in birds in 1935. Steroid female hormones injected in vivo into male embryos determined a partial or total feminization of gonads and genital ducts. Male hormones determined only the sex reversal of the ducts. Some substances of the group of androgens, such as dehydroandrosterone, had a paradoxical effect; they feminized males and masculinized females. Similar effects were observed later by several authors in all groups of vertebrates. In placentary mammals, only genital ducts were transformed. Castration of avian embryos also demonstrated the role of embryonic sexual hormones on genital ducts. These results, first obtained in vivo, were confirmed by experiments in vitro. Since then numerous studies have been undertaken on the nature of the hormone responsible for the regression of müllerian ducts in embryos of birds and other groups of vertebrates. Some authors assumed that these substances are proteins; many offered new evidence for the role of steroid sexual hormones during sex differentiation. Thus the problem appeared more complicated than it was thought at first. In recent years, synthesis of steroid sexual hormones have been demonstrated in young embryos during or even before sex differentiation; and enzymes that catalyze the synthesis of these hormones, such as hydroxysteroiddehydrogenase, also have been discovered. Further research has been oriented toward the characterization of steroid hormones by techniques of immunochemistry and labeled isotopes confirming the results obtained by other techniques. Specific proteins are being isolated in the effectors; they work as receptors of steroid hormones. Nuclear receptors of estradiol have been discovered in the embryonic gonads and in the cloacal wall at the time of sexual differentiation. Thus a mechanism can be conceived in which proteins and steroid hormones play mutual roles in the process of sex differentiation. Presented in the formal symposium on Sexual Differentiation in Vitro and in Vivo at the 29th Annual Meeting of the Tissue Culture Association, Denver, Colorado, June 4–8, 1978.     

Measurement of endogenous subcellular concentration of steroids in tissue

A reliable method for the extraction of steroid hormones from human uterine tissue and the subsequent measurement of these hormones in the subcellular compartments by radioimmunoassay is described. Extraction of radioactive steroid hormones from in vivo labelled human uterine tissue by different methods reveals that an almost quantitative extraction of steroid hormones from the nuclear fraction is obtained by sonication in ethanol-acetone. Extraction of steroid hormones with diethylether from a high speed cytosol is incomplete. Using a more potent denaturating agent prior to extraction with diethyl ether leads to complete extraction of unconjugated steroids.     

Hsd3b2 associated in modulating steroid hormone synthesis pathway regulates the differentiation of chicken embryonic stem cells into spermatogonial stem cells

Steroid hormones regulate differentiation of various types of cell during embryogenesis. Testosterone is one of the androgens that bind to receptors to regulate gene expression and promote spermatogenesis. Our results showed that testosterone, as a product of steroid hormones synthesis pathway, could facilitate the differentiation of embryonic stem cells (ESCs) into spermatogonial stem cells (SSCs). The analysis of the steroid hormones synthesis pathway demonstrated that 3beta‐hydroxysteroid dehydrogenase2 (Hsd3b2) plays a major role in the synthesis of testosterone. In the absence of Hsd3b2, the expression of downstream genes such as Cyp1a1, Ugt1a1, and Hsd17b7 was not maintained. This reduction is probably due to the down‐regulation of the steroid hormones synthesis pathway. Furthermore, qRT‐PCR, immunofluorescence, and flow cytometry analysis confirmed that the steroid hormones synthesis pathway could facilitate the differentiation of ESCs. Altogether, these results lead to a model in which Hsd3b2 regulates ESCs differentiation via modulating the activity of steroid hormones synthesis pathway.     

Immunochemical analysis of the interaction of the fertility alpha 2-microglobulin with steroid sex hormones

The interaction between the fertility alpha 2-microglobulin and steroid sex hormones (estrone, estriol, estradiol, progesterone, testosterone) was studied by the use of cross immunoelectrophoresis with intermediate gels. alpha 2-microglobulin was shown to bind to the above hormones, its affinity to testosterone being the highest. The ability of alpha 2-microglobulin to bind to steroid hormones can be used for its isolation by affinity chromatography with immobilized steroid hormones.     

Steroid hormones regulate programmed cell death: a review

Programmed cell death (PCD) is a physiologically active process which is essential for the proper functioning of any living tissue. The steroid hormones modulate the programme in the immunological and reproductive organs and tissues, such as the thymus gland, circulating thymocytes, uterus, vagina, testis, ovary and prostrate gland. The influence of steroid hormones on cell death is tissue specific; the same hormone can inhibit PCD in one tissue, and may promote PCD in another tissue. The roles of apoptosis and terminal differentiation have been examined, and the regulation of PCD by steroid hormones, assessed.     

Steroid Hormone Actions on the Brain: When Is the Genome Involved?

It has become customary to distinguish between so-called "genomic" actions of steroid hormones involving intracellular receptors and "non-genomic" effects of steroids that involve putative cell surface receptors. Whereas there is no doubt that this distinction has considerable validity, it does not go far enough in addressing the variety of mechanisms that steroid hormones use to produce their effects on cells. This is because cell surface receptors may signal changes in gene expression, while genomic actions sometimes affect neuronal excitability, often doing so quite rapidly. Moreover, steroid hormones and neurotransmitters may operate together to produce effects, and sometimes these effects involve collaborations between groups of neurons. As illustrations. evidence is reviewed in this article that a number of steroid actions in the hippocampus involves the co-participation of excitatory amino acids. These interactions are evident for the regulation of synaptogenesis by estradiol in the CA1 pyramidal neurons or hippocampus and for the induction of dendritic atrophy of CA3 neurons by repeated stress as well as by glucocorticoid injections. In addition, neurogenesis in the adult and developing dentate gyrus is "contained" by adrenal steroids as well as by excitatory amino acids. In each of these three examples, NMDA receptors are involved. These results not only point to a high degree of interdependency between certain neurotransmitters and the actions of steroid hormones but also emphasize the degree to which structural plasticity is an important aspect of steroid hormone action in the adult as well as developing nervous system.     

Sex steroid hormones enhance hypotensive effects of calcitonin gene-related Peptide in aged female rats

The aim of the present study is to investigate whether vascular protective effects of steroid hormones in aged female rats are mediated through calcitonin gene-related peptide (CGRP), a known potent vasodilator. This rat model reflects the postmenopausal state in humans. We examined whether blood pressure lowering effects of CGRP are enhanced in aged female rats when steroid hormone treatments are administered. We observed that 1) continuous infusion of CGRP lowered blood pressures in rats treated with estradiol-17beta and progesterone (P < 0.05), 2) acute hypotensive effects of CGRP were significantly (P < 0.05) greater in the presence of steroid hormones than in vehicle-treated groups, 3) blood pressure decreases in response to CGRP are lower in aged female rats than they are in young adult ovariectomized rats, and 4) age-related differences in the hypotensive effects of CGRP were nullified when animals were treated with steroid hormones. These data suggest that female sex steroid hormones may modulate arterial blood pressure by regulating the CGRP effector system in female rats regardless of age.     

综述与专论: 甾体激素核酸适配体的筛选与应用

核酸适配体作为新型的识别分子，在分析检测领域有极大的潜力。甾体激素是一类以环戊烷多氢菲为母核的激素，包括性激素和皮质激素，在维持生命、调节生理状态等方面有着极其重要的医药价值。监测体内外的甾体激素含量对于疾病监测和环境保护有着重要的意义。甾体激素的适配体筛选是将适配体应用到甾体激素的分析和检测的前提。目前研究者已通过筛选获得了雌激素（如雌二醇（estradiol，E2）、雌酮（estrone，E1））、雄激素（如睾酮（testosterone，TES）、去甲睾酮）、孕激素（如孕酮（progesterone，P4）），以及皮质激素（如皮质醇（cortisol，COR））的核酸适配体。本文总结了上述已报道的甾体激素适配体的筛选原理及策略；对适配体序列、平衡解离常数（equilibrium dissociation constants，K_D）及测定方法等进行了简要归纳；介绍了计算机模拟技术在适配体筛选和优化方面的新思路；对目前开发的各类甾体激素适配体传感器进行简要介绍，以期为后续研究提供参考。     

Effects of delayed phlebotomy on plasma steroid hormone concentrations in two elasmobranch species

Measuring circulating concentrations of steroid hormones can be used as a method for determining reproductive maturity and cycles in elasmobranchs. However, it is unknown how long steroid hormones remain stable in elasmobranch blood following capture, and thus how quickly these samples should be collected for the results of subsequent steroid hormone analyses to be accurate. The objectives of this study were to determine if the sex steroid hormones progesterone, testosterone and estradiol would remain at stable concentrations in the blood of the Spiny Dogfish (Squalus acanthias Linnaeus, 1758) and the Atlantic Sharpnose Sharks (Rhizoprionodon terraenovae Richardson, 1836) that were captured, left on deck and un‐refrigerated for 24 hr. Blood samples were serially drawn from five initially live sharks over a period of 24 hr. While concentrations of all three hormones did significantly fluctuate over the sampling period in both species, the resulting hormone concentrations from each sampling period still fell within the range of previously reported values for each species in their respective reproductive stage. Additionally, no significant changes in hematocrit were detected in either species over the 24‐hr period. This research represents an extreme situation in which sharks were left on deck and un‐refrigerated, and suggests that even when subjected to these conditions steroid hormone concentrations may fluctuate, but the resulting values may still be useful for assessing reproductive stage.     

Measurement of steroid sex hormones in serum: a comparison of radioimmunoassay and mass spectrometry

Concern has been raised about the adequacy of radioimmunoassays to measure steroid sex hormones in population studies. We compared steroid sex hormone measurements in serum by radioimmunoassay with mass spectrometry. Four male and four female serum pools with known relative concentrations of steroid sex hormones were measured multiple times by both methods. Because measurements are expected to increase linearly with concentration for each sex, we examined whether the linear regressions of hormone measurements on concentration were the same for radioimmunoassay and mass spectrometry. Estradiol, estrone, androstenedione, testosterone, and dehydroepiandrosterone sulfate were measured in female pools; testosterone, dihydrotestosterone, androstenedione, and dehydroepiandrosterone sulfate were measured in male pools. Regression slopes for radioimmunoassay and mass spectrometry measurements were comparable for all hormones except androstenedione, which had a steeper slope when measured by mass spectrometry (P < or = 0.02). Intercepts for radioimmunoassay and mass spectrometry were similar and close to zero for estradiol, androstenedione, dehydroepiandrosterone sulfate, and in male samples, testosterone. For testosterone in female samples, estrone, and dihydrotestosterone, radioimmunoassay and mass spectrometry intercepts differed significantly. Standard deviations of individual measurements by radioimmunoassay and mass spectrometry differed by hormone and serum concentration; neither method consistently measured hormone concentrations with less variability. Our findings suggest that although absolute concentrations may differ for some hormones, radioimmunoassay and mass spectrometry can yield similar estimates of between subject differences in serum concentrations of most steroid sex hormones commonly measured in population studies. Relative power of studies using radioimmunoassay and mass spectrometry will depend on the hormones measured and their serum concentrations.     

Gender-dimorphic regulation of antioxidant proteins in response to high-fat diet and sex steroid hormones in rats

Abstract

Despite the fact that gender dimorphism in diet-induced oxidative stress is associated with steroid sex hormones, there are some contradictory results concerning roles of steroid hormones in gender dimorphism. To evaluate the role of gender dimorphism as well as the effects of sex steroid hormones in response to high-fat diet (HFD)-induced oxidative stress, we measured cellular levels of major antioxidant proteins in the liver, abdominal white adipose tissue, and skeletal muscles of Sprague-Dawley rats following HFD or sex hormone treatment using Western blot analysis. Animal experiments revealed that 17β-estradiol, (E2) and dihydrotestosterone (DHT) negatively and positively affected body weight gain, respectively. Interestingly, plasma levels of malondialdehyde (MDA) increased in both E2- and DHT-treated rats. We also observed that cellular levels of classical antioxidant proteins, including catalase, glutathion peroxidase, peroxiredoxin, superoxide dismutase, and thioredoxin, were differentially regulated hormone- and gender-dependent manner in various metabolic tissues. In addition, tissue-specific expression of DJ-1 protein with respect to HFD-induced oxidative stress in association with sex steroid hormone treatment was observed for the first time. Taken together, our data show that females were more capable at overcoming oxidative stress than males through feasible expression of antioxidant proteins in metabolic tissues. Although the exact regulatory mechanism of sex hormones in diet-induced oxidative stress could not be fully elucidated, the current data will provide clues regarding the tissue-specific roles of antioxidant proteins during HFD-induced oxidative stress in association with sex steroid hormones.     

The effect of selected human steroid hormones upon the growth of dermatophytes with different adaptation to man

The inhibitory effect exerted by steroid hormones on thein vitro growth characteristics of dermatophytes is poorly understood. As a hypothesis this inhibition could result from fungal adaptation to the human host. Therefore, in this study the susceptibility of representative anthropophilic, zoophilic and geophilic dermatophytes to hormonal inhibition was compared. As a result, in agar dilution assaysprogesterone,testosterone, andestradiol proved to reduce fungal growth, whereashydrocortisone had no such effect. In general, anthropophilic dermatophytes were shown to be more responsive to steroid hormones than geophilic species, suggesting a correlation of steroid susceptibility with adaptation to human skin. However, since fungal response to hormones consisted of growth inhibition and occurred only at steroid concentrations much higher than present in human skin, it cannot be assumed to contribute to this adaptation.     

Local increase of ovarian steroid hormone concentration in blood supplying the oviduct and uterus during early pregnancy of sows

Countercurrent transfer in the ovarian vascular pedicle elevates the concentration of steroid hormones in blood supplying the oviduct and periovarian part of the uterus during the estrous cycle in the pig. This study was conducted to determine whether during early pregnancy the arterial blood supply to the oviduct and uterus carries greater concentration of steroid hormone than systemic blood. The concentration of ovarian steroid hormones (progesterone, estradiol-17 beta, estrone, androstenedione and testosterone) was measured in 40 gilts on Days 12, 18, 25 or 35 of pregnancy. Silastic catheters were inserted: a) into the jugular vein, b) into the branch of uterine artery close to the ovary (proximal to the ovary) and c) into the branch of the uterine artery close to the cervix (distal to the ovary). On the day following surgery simultaneous blood samples from cannulated vessels were collected every 20 min for 3 hours. The concentration of steroid hormones was determined by radioimmunoassay. The mean concentrations of studied hormones in branches of the uterine artery proximal and distal to the ovary were significantly greater than in the jugular vein (P < 0.001) by 18 to 69% and 7 to 31%, respectively. The concentrations of hormones in proximal and distal to the ovary branch of the uterine artery were also significantly different (P < 0.001). The increase in concentrations of the measured hormones did not differ considerably between investigated days of pregnancy. It is concluded that during maternal recognition of pregnancy, formation of the corpus luteum of pregnancy, implantation of the embryo and the placenta elongation the oviduct and uterus are supplied with locally elevated concentration of steroid hormones compared to systemic blood.     

The use of embryo transfer and steroid hormone replacement therapy in the study of prenatal mortality

Embryo transfer and steroid hormone replacement therapy have been used to advantage in studies on prenatal mortality, particularly in sheep.The form, timing and magnitude of loss, have been well documented and steroid hormone replacement therapy coupled with embryo transfer has clearly shown the involvement of the ovarian steroid hormones secreted before, during and after estrus in survival and development of embryos.However, little is known of the manner in which the steroid hormones exert their effects on the environment of pre-implantation embryos; a stage when most mortality occurs.     

Sex Steroids Mediate Bidirectional Interactions Between Hosts and Microbes

The outcome of microbial infections in mammals, including humans, is affected by the age, sex, and reproductive status of the host suggesting a role for sex steroid hormones. Testosterone, estradiol, and progesterone, signaling through their respective steroid receptors, affect the functioning of immune cells to cause differential susceptibility to parasitic, bacterial, and viral infections. Microbes, including fungi, bacteria, parasites, and viruses, can also use sex steroid hormones and manipulate sex steroid receptor signaling mechanisms to increase their own survival and replication rate. The multifaceted use of sex steroid hormones by both microbes and hosts during infection forms the basis of this review. In the arms race between microbes and hosts, both hosts and microbes have evolved to utilize sex steroid hormone signaling mechanisms for survival.     

Non-genomic,direct modulatory effect of 17β-estradiol,progesterone and their synthetic derivatives on the activity of human erythrocyte CuZn superoxide dismutase

Abstract

This study aimed to evaluate whether natural or synthetic steroid hormones could directly modulate the activity of the different superoxide dismutase (SOD) isoforms found in human blood fractions without changing enzyme expression. Enzyme samples of human erythrocytes, the human platelet-rich plasma fraction (PRP) or isolated CuZnSOD, which was purified from human erythrocytes were pre-incubated with natural steroids (17β-estradiol 17-acetate and progesterone) and their synthetic derivatives (β-estradiol 3-benzoate and medroxyprogesterone 17-acetate). Then, CuZn and MnSOD activities were measured using the xanthine/xanthine oxidase/nitroblue tetrazolium method. Hormones had no effect on MnSOD activity from the PRP, but we show for the first time that natural and synthetic steroid hormones have a direct, bell-shaped effect on the activity of CuZnSOD from both male and female human erythrocytes. Low (physiological) hormone concentrations caused a dose-dependent increase in enzyme activity, which disappeared at higher hormone concentrations. In addition, the combination of synthetic and natural estrogens and progestins had a synergistic stimulatory effect on the activity of CuZnSOD from human erythrocytes. The molecular interaction between CuZnSOD and steroid hormones was preliminarily studied. Natural hormones did not change the electrophoretic mobility of SOD under denaturing conditions, but they did increase the absorption spectra of SOD in the 230–290 nm range. These data suggest that hormone-mediated modulation of CuZnSOD is related to subtle changes in protein conformation, possibly related to Trp and Phe residues. We propose that this effect may account for the physiological regulation of enzyme activity during conditions where steroid hormones undergo alterations as the ovulatory cycle.     

Hormones in the Lives of Crustaceans: An Overview

We present an overview of the isolation and characterizationof three hormones (or hormone families) important for the growthand development of decapod crustaceans. These hormones includethe ecdysteroids (steroid molting hormones), the hyperglycemichormone neuropeptide family, and the terpenoid methyl farnesoate.Using examples primarily from our laboratory, we describe workon these hormones using various life stages of the lobster (Homarusamericanus) as the principal model.     

The endocrinology of pregnancy and fetal loss in wild baboons

An impressive body of research has focused on the mechanisms by which the steroid estrogens (E), progestins (P), and glucocorticoids (GC) ensure successful pregnancy. With the advance of non-invasive techniques to measure steroids in urine and feces, steroid hormones are routinely monitored to detect pregnancy in wild mammalian species, but hormone data on fetal loss have been sparse. Here, we examine fecal steroid hormones from five groups of wild yellow baboons (Papio cynocephalus) in the Amboseli basin of Kenya to compare the hormones of successful pregnancies to those ending in fetal loss or stillbirth. Using a combination of longitudinal and cross-sectional data, we analyzed three steroid hormones (E, P, GC) and related metabolites from 5 years of fecal samples across 188 pregnancies. Our results document the course of steroid hormone concentrations across successful baboon pregnancy in the wild and demonstrate that fecal estrogens predicted impending fetal loss starting 2 months before the externally observed loss. By also considering an additional 450 pregnancies for which we did not have hormonal data, we determined that the probability for fetal loss for Amboseli baboons was 13.9%, and that fetal mortality occurred throughout gestation (91 losses occurred in 656 pregnancies; rates were the same for pregnancies with and without hormonal data). These results demonstrate that our longstanding method for early detection of pregnancies based on observation of external indicators closely matches hormonal identification of pregnancy in wild baboons.