International Meeting on The Neuroendocrine and Intragonadal Regulation of Testicular Function: Recent Progress and International Workshop on Interactions Between Sex-Steroids and Catecholamine Secretion in Vivo and in Vitro

1993 ◽  
Vol 16 (7) ◽  
pp. 504-504
Keyword(s):  
Sex Steroids ◽  
Recent Progress ◽  
International Workshop ◽  
Catecholamine Secretion ◽  
Testicular Function ◽  
International Meeting

scholarly journals The Anticancer Effects of Paeoniflorin and Its Underlying Mechanisms

2019 ◽  
Vol 14 (9) ◽  
pp. 1934578X1987640
Author(s):  
Li-Juan Deng ◽  
Yu-He Lei ◽  
Tsz-Fung Chiu ◽  
Ming Qi ◽  
Hua Gan ◽  
...  
Keyword(s):  
Recent Progress ◽  
Antitumor Effect ◽  
Molecular Mechanisms ◽  
Experimental Studies ◽  
Future Prospects ◽  
Anticancer Effects ◽  
Wide Range ◽  
Underlying Mechanisms

Paeoniflorin (PF) is an important pharmacological component of some Chinese traditional herbal formulas, such as Bai Shao, Chi Shao, and Dan Pi, which have been clinically used for centuries. Although many experimental studies have explored a wide range of pharmacological properties of PF, including anticancer, anti-inflammatory, antioxidant, immunoregulatory, and prevention of insulin resistance, there is no review to describe these reported effects systematically, especially the antitumor effect and the underlying mechanisms. In this review, we summarize the recent progress on the anticancer profiles both in vitro and in vivo of PF. Moreover, we highlight the integrated molecular mechanisms of PF and contemplate its future prospects as a potential anticancer drug.

scholarly journals Challenges and perspectives for structural biology of lncRNAs—the example of the Xist lncRNA A-repeats

2019 ◽  
Vol 11 (10) ◽  
pp. 845-859 ◽  
Author(s):  
Alisha N Jones ◽  
Michael Sattler
Keyword(s):  
High Resolution ◽  
Structural Biology ◽  
Recent Progress ◽  
Molecular Mechanisms ◽  
Rna Binding ◽  
Rna Binding Proteins ◽  
Structural Features ◽  
Molecular Features

Abstract Following the discovery of numerous long non-coding RNA (lncRNA) transcripts in the human genome, their important roles in biology and human disease are emerging. Recent progress in experimental methods has enabled the identification of structural features of lncRNAs. However, determining high-resolution structures is challenging as lncRNAs are expected to be dynamic and adopt multiple conformations, which may be modulated by interaction with protein binding partners. The X-inactive specific transcript (Xist) is necessary for X inactivation during dosage compensation in female placental mammals and one of the best-studied lncRNAs. Recent progress has provided new insights into the domain organization, molecular features, and RNA binding proteins that interact with distinct regions of Xist. The A-repeats located at the 5′ end of the transcript are of particular interest as they are essential for mediating silencing of the inactive X chromosome. Here, we discuss recent progress with elucidating structural features of the Xist lncRNA, focusing on the A-repeats. We discuss the experimental and computational approaches employed that have led to distinct structural models, likely reflecting the intrinsic dynamics of this RNA. The presence of multiple dynamic conformations may also play an important role in the formation of the associated RNPs, thus influencing the molecular mechanism underlying the biological function of the Xist A-repeats. We propose that integrative approaches that combine biochemical experiments and high-resolution structural biology in vitro with chemical probing and functional studies in vivo are required to unravel the molecular mechanisms of lncRNAs.

Estrogens and progestins: molecular effects on brain cells

2010 ◽  
Vol 4 (3) ◽  
Author(s):  
Paolo Mannella ◽  
Tommaso Simoncini ◽  
Andrea Riccardo Genazzani
Keyword(s):  
Sex Steroids ◽  
Molecular Mechanisms ◽  
Neural Cells ◽  
Protective Effects ◽  
Complete Knowledge ◽  
Molecular Effects ◽  
In Vivo Effects ◽  
The Brain

AbstractSex steroids are known to regulate brain function and their role is so important that several diseases are strictly correlated with the onset of menopause when estrogen-progesterone deficiency makes neural cells much more vulnerable to toxic stimuli. Although in the past years several scientists have focused their studies on in vitro and in vivo effects of sex steroids on the brain, we are still far from complete knowledge. Indeed, contrasting results from large clinical trials have made the entire issue much more complicated. Currently we know that protective effects exerted by sex steroids depend on several factors among which the dose, the health of the cells and the type of molecule being used. In this review, we present an overview of the direct and indirect effects of estrogen and progesterone on the brain with specific focus on the molecular mechanisms by which these molecules act on neural cells.

Glutamate Monitoring In Vitro and In Vivo: Recent Progress in the Field of Glutamate Biosensors

2009 ◽  
Vol 1 (2) ◽  
pp. 100-115 ◽  
Author(s):  
Nathalie Rieben ◽  
Nadia Cherouati ◽  
Karen L. Martinez
Keyword(s):  
Recent Progress

scholarly journals Sex steroids influence organizational but not functional decidualization of feline endometrial cells in a 3D culture system†

2019 ◽  
Vol 101 (5) ◽  
pp. 906-915 ◽  
Author(s):  
Kathryn Wilsterman ◽  
Xinmiao Bao ◽  
Allegra D Estrada ◽  
Pierre Comizzoli ◽  
George E Bentley
Keyword(s):  
Sex Steroids ◽  
Culture System ◽  
Three Dimensional ◽  
3D Culture ◽  
In Vitro Models ◽  
Sex Steroid ◽  
Endometrial Cells ◽  
Organizational Patterns

Abstract Successful implantation requires complex signaling between the uterine endometrium and the blastocyst. Prior to the blastocyst reaching the uterus, the endometrium is remodeled by sex steroids and other signals to render the endometrium receptive. In vitro models have facilitated major advances in our understanding of endometrium preparation and endometrial–blastocyst communication in mice and humans, but these systems have not been widely adapted for use in other models which might generate a deeper understanding of these processes. The objective of our study was to use a recently developed, three-dimensional culture system to identify specific roles of female sex steroids in remodeling the organization and function of feline endometrial cells. We treated endometrial cells with physiologically relevant concentrations of estradiol and progesterone, either in isolation or in combination, for 1 week. We then examined size and density of three-dimensional structures, and quantified expression of candidate genes known to vary in response to sex steroid treatments and that have functional relevance to the decidualization process. Combined sex steroid treatments recapitulated organizational patterns seen in vivo; however, sex steroid manipulations did not induce expected changes to expression of decidualization-related genes. Our results demonstrate that sex steroids may not be sufficient for complete decidualization and preparation of the feline endometrium, thereby highlighting key areas of opportunity for further study and suggesting some unique functions of felid uterine tissues.

Comparing in vivo and in vitro approaches to study the hormonal regulation of sea urchin reproduction

2016 ◽  
Vol 96 (6) ◽  
pp. 1363-1372 ◽  
Author(s):  
Silvia Mercurio ◽  
Michela Sugni
Keyword(s):  
Sea Urchin ◽  
Sex Steroids ◽  
Hormonal Regulation ◽  
Gonad Development ◽  
Hormonal Treatment ◽  
Paracentrotus Lividus ◽  
Sex Steroid ◽  
Future Research

Although in vivo and in vitro approaches appear to be very different, they are related and complementary techniques and both are essential for the investigation of diverse biological topics. The employment of both techniques was considered particularly appropriate to investigate the role of 17β-oestradiol and testosterone in echinoid reproductive biology. The relationship between sex-steroids and echinoid reproduction has not been clearly determined yet, due to the highly variable and sometimes contrasting results obtained from steroid administration experiments. These might be due to the activation of protective metabolic mechanisms that can prevent the exogenous molecules from exerting their biological functions, as observed in our previous research. To clarify these aspects, in the present study we explored sex-steroid involvement in the reproduction of the sea urchin Paracentrotus lividus, employing both in vivo and in vitro approaches: (1) an experiment involving hormone dietary administration was performed and different reproductive parameters were deeply analysed; (2) ovarian cells were cultured in the presence of the same steroids and morphological and biochemical analyses were carried out. According to our results, sex-steroids appear not to be involved in sea urchin gonad development and gamete maturation, as neither in vivo administration nor in vitro exposure influenced gonad and gamete growth. In addition, in vitro hormonal treatment did not affect sea urchin Major Yolk Protein content. Overall, the present work complements our previous research providing information on sex-steroid involvement in echinoid reproduction and illustrates new methodological approaches that will be useful for future research on invertebrate biology and physiology.

Sex steroids and the initiation of puberty in male African catfish (Clarias gariepinus)

1998 ◽  
Vol 275 (6) ◽  
pp. R1793-R1802 ◽  
Author(s):  
J. Eduardo B. Cavaco ◽  
Cécile Vilrokx ◽  
Vance L. Trudeau ◽  
Rüdiger W. Schulz ◽  
Henk J. T. Goos
Keyword(s):  
Sex Steroids ◽  
Histological Analysis ◽  
Clarias Gariepinus ◽  
African Catfish ◽  
Direct Effects ◽  
Control Groups ◽  
Estradiol 17Β ◽  
Testis Tissue

The effects of sex steroids on spermatogenesis and testicular androgen secretion were studied in juvenile (spermatogonia present in testes) African catfish. Fish were implanted with Silastic pellets containing 11-ketotestosterone (KT), 11β-hydroxyandrostenedione (OHA), androstenetrione (OA), androstenedione (A), testosterone (T), 5α-dihydrotestosterone (DHT), or estradiol-17β (E2). Control groups received steroid-free pellets. Two weeks later, testis tissue fragments were incubated with African catfish luteinizing hormone (LH) and the amount of OHA secreted in vitro (the main androgen produced by African catfish testes) was quantified. Tissue fragments were then fixed for histological analysis of spermatogenesis. Treatment with KT, OHA, and OA stimulated testicular growth and spermatogenesis (spermatocytes and spermatids were found), whereas T, DHT, A, or E2 had no such effects. All steroids, except for DHT and E2, reduced OHA secretion in the absence and presence of LH to ∼10% of the control values. Previous studies have shown that KT, OHA, and OA have little effect on circulating LH levels in juvenile male African catfish, so that these androgens probably had direct effects on the testis. Inasmuch as OHA, OA, and KT have largely similar effects and because OHA and OA are converted to KT in vivo, we suggest that KT is physiologically the most relevant androgen for the initiation of spermatogenesis in African catfish.

scholarly journals Spermatogonial Stem Cells for In Vitro Spermatogenesis and In Vivo Restoration of Fertility

Cells ◽  
2020 ◽  
Vol 9 (3) ◽  
pp. 745 ◽  
Author(s):  
Fahar Ibtisham ◽  
Ali Honaramooz
Keyword(s):  
Stem Cells ◽  
Germ Cells ◽  
Recent Progress ◽  
Male Germ Cells ◽  
Culture Systems ◽  
In Vitro Spermatogenesis ◽  
Haploid Male ◽  
Restoration Of Fertility

Spermatogonial stem cells (SSCs) are the only adult stem cells capable of passing genes onto the next generation. SSCs also have the potential to provide important knowledge about stem cells in general and to offer critical in vitro and in vivo applications in assisted reproductive technologies. After century-long research, proof-of-principle culture systems have been introduced to support the in vitro differentiation of SSCs from rodent models into haploid male germ cells. Despite recent progress in organotypic testicular tissue culture and two-dimensional or three-dimensional cell culture systems, to achieve complete in vitro spermatogenesis (IVS) using non-rodent species remains challenging. Successful in vitro production of human haploid male germ cells will foster hopes of preserving the fertility potential of prepubertal cancer patients who frequently face infertility due to the gonadotoxic side-effects of cancer treatment. Moreover, the development of optimal systems for IVS would allow designing experiments that are otherwise difficult or impossible to be performed directly in vivo, such as genetic manipulation of germ cells or correction of genetic disorders. This review outlines the recent progress in the use of SSCs for IVS and potential in vivo applications for the restoration of fertility.

Action, localization and structure-function relationship of growth factors and their receptors in the prostate

1996 ◽  
Vol 5 (2) ◽  
pp. 73-105 ◽  
Author(s):  
S Chevalier ◽  
AG Aprikian ◽  
G Beauregard ◽  
I Defoy ◽  
LT Nguyen ◽  
...  
Keyword(s):  
Growth Factors ◽  
Cell Division ◽  
Sex Steroids ◽  
Steroid Receptors ◽  
Direct Action ◽  
Culture Conditions ◽  
Mitogenic Activity ◽  
Prostate Cell

Whereas the direct action of sex steroids, namely of androgens, on prostate cell division was questioned as early as in the 1970s, and remains so, the interest in prostatic growth factors (GFs) is rather recent but has expanded tremendously in the last five years. This lag period can be partly explained by the fact that, at the time, androgen receptors had just been discovered, and newly developed hormonal regimens or strategies to treat patients with prostate carcinoma (PCa) or epithelioma had generated great enthusiasm and hopes in the medical and scientific community. Another point to consider was the difficulty in maintaining prostate tissues in organ cultures and the relative novelty of culturing prostate epithelial cells in monolayers. Failures of sex steroids to elicit a direct positive response on prostate cell division in vitro, as seen in vivo, were interpreted as resulting from inappropriate models or culture conditions. However, the increasing number of reports confirming the lack of mitogenic activity of sex steroids in vitro, coupled with the powerful mitogenic activity of GFs displayed in other systems, the discovery of GF receptors (GF-Rs), and the elucidation of their signalling pathways showing sex steroid receptors as potential substrates of GF-activated protein kinases gradually led to an increased interest in the putative role of GFs in prostate physiopathology. Of utmost importance was the recognition that hormone refractiveness was responsible for PCa progression, and for the poor outcome of patients with advanced disease under endocrine therapies. This problem remains a major issue and it raises several key questions that need to be solved at the fundamental and clinical levels.

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