Browsing by Author "Shabana Anjum"

Now showing 1 - 7 of 7

Alteration in expression of estrogen receptor isoforms alpha and beta, and aromatase in the testis and its relation with changes in nitric oxide during aging in mice
(2012) Arnab Banerjee; Shabana Anjum; Rachna Verma; Amitabh Krishna
The aim of present study was to investigate the changes in the testicular expression of aromatase, ER alpha, ER beta and iNOS protein and correlate these with serum testosterone and nitric oxide levels, to elucidate the role of estrogen and nitric oxide in the testis during aging. This study showed localization of aromatase and ER alpha mainly in the Leydig cell and showed close correlation of testicular aromatase level with circulating testosterone level suggesting that estrogen may be modulating testicular steroidogenesis. Localization ER alpha mainly in the mitotically active germ cell suggest possible role of estrogen in germ cell proliferation. This study showed basal level of nitric oxide during reproductively active period, whereas increased serum nitric oxide coincides with decreased testicular activity in old age. This study showed inverse correlation between aromatase and NO level. Treatment with either SNP or L-NAME on testicular steroidogenic factor (3-beta HSD/ StAR) or germ cell survival factor (Bcl2) showed that increased NO causes decreased steroidogenesis and increased germ cell apoptosis. In conclusion this study suggest that estrogen modulate steroidogenesis and germ cell survival in reproductively active period whereas in old age decreased estrogen concentration causes increased nitric oxide which in turn decreases testicular steroidogenesis and germ cell apoptosis. © 2012 Elsevier Inc. All rights reserved.
Central and peripheral neuropeptide RFRP-3: A bridge linking reproduction, nutrition, and stress response
(Academic Press Inc., 2022) Padmasana Singh; Shabana Anjum; Raj Kamal Srivastava; Kazuyoshi Tsutsui; Amitabh Krishna
This article is an amalgamation of the current status of RFRP-3 (GnIH) in reproduction and its association with the nutrition and stress-mediated changes in the reproductive activities. GnIH has been demonstrated in the hypothalamus of all the vertebrates studied so far and is a well-known inhibitor of GnRH mediated reproduction. The RFRP-3 neurons interact with the other hypothalamic neurons and the hormonal signals from peripheral organs for coordinating the nutritional, stress, and environmental associated changes to regulate reproduction. RFRP-3 has also been shown to regulate puberty, reproductive cyclicity and senescence depending upon the nutritional status. A favourable nutritional status and the environmental cues which are permissive for the successful breeding and pregnancy outcome keep RFRP-3 level low, whereas unfavourable nutritional status and stressful conditions increase the expression of RFRP-3 which impairs the reproduction. Still our knowledge about RFRP-3 is incomplete regarding its therapeutic application for nutritional or stress-related reproductive disorders. © 2022 Elsevier Inc.
Inhibitory roles of the mammalian GnIH ortholog RFRP3 in testicular activities in adult mice
(BioScientifica Ltd., 2014) Shabana Anjum; Amitabh Krishna; Kazuyoshi Tsutsui
The aim of this study was to evaluate the effects of in vivo and in vitro treatments with RFamide-related peptide 3 (RFRP3), a mammalian gonadotropin-inhibitory hormone ortholog, on testicular activities, i.e. spermatogenesis and steroidogenesis, in mice. Mice were treated in vivo with different doses of RFRP3 (control: 0.02 μg, 0.2 μg, and 2.0 μg/day) for 8 days. For in vitro study, the testes of mice were evaluated with different doses of RFRP3 (control: 1 and 10 ng/ml) with or without LH (control: 10 and 100 ng/ml) for 24 h at 37 °C. RFRP3 treatment produced significant changes in the body mass, circulating steroid level, and testicular activity in mice. RFRP3 treatment also caused dose-dependent histological changes in spermatogenesis, such as decline in germ cell proliferation and survival markers and increase in apoptotic markers in testis. Both in vivo and in vitro studies showed the inhibitory effect of RFRP3 on testosterone synthesis in the testis. RFRP3 inhibited the expression of the receptor for LH (LHCGR), STAR protein, cytochrome P450 side-chain cleavage (CYP11A1) and 3ß-hydroxysteroid dehydrogenase in the testis, and testosterone secretion dose dependently. This study also suggested that the inhibitory effect of RFRP3 in the testis may be mediated through local production of GnRH. Thus, RFRP3 inhibits testicular steroidogenesis and spermatogenesis either indirectly through GnRH or by directly influencing germ cell proliferation, survival, and apoptosis. © 2014 Society for Endocrinology.
Localization of Gonadotropin-Releasing Hormone (GnRH), Gonadotropin-Inhibitory Hormone (GnIH), Kisspeptin and GnRH Receptor and Their Possible Roles in Testicular Activities From Birth to Senescence in Mice
(2012) Shabana Anjum; Amitabh Krishna; Rajagopala Sridaran; Kazuyoshi Tsutsui
The changes in distribution and concentration of neuropeptides, gonadotropin-releasing hormone (GnRH), gonadotropin-inhibitory hormone (GnIH), kisspeptin, and gonadotropin-releasing hormone receptor (GnRH-R) were evaluated and compared with reproductive parameters, such as cytochrome P450 side-chain cleavage (P450 SCC) enzyme activity, androgen receptors (AR) in the testis and serum testosterone levels, from birth to senescence in mice. The results showed the localization of these molecules mainly in the interstitial and germ cells as well as showed significant variations in immunostatining from birth to senescence. It was found that increased staining of testicular GnRH-R coincided with increased steroidogenic activity during pubertal and adult stages, whereas decreased staining coincides with decreased steroidogenic activity during senescence. Similar changes in immunostaining were confirmed by Western/slot blot analysis. Thus, these results suggest a putative role of GnRH during testicular pubertal development and senescence. Treatment with a GnRH agonist ([DTrp6, Pro9-NEt] GnRH) to mice from prepubertal to pubertal period showed a significant increase in steroidogenic activity of the mouse testis and provided further support to the role of GnRH in testicular pubertal maturation. The significant decline in GnRH-R during senescence may be due to a significant increase in GnIH synthesis during senescence causing the decrease in GnRH-R expression. It is considered that significant changes in the levels of GnRH-R may be responsible for changes in steroidogenesis that causes either pubertal activation or senescence in testis of mice. Furthermore, changes in the levels of GnRH-R may be modulated by interactions among GnRH, GnIH, and kisspeptin in the testis. © 2012 Wiley Periodicals, Inc.
Oxytocin as a modulator for puberty development and its role in social cognition
(Nova Science Publishers, Inc., 2020) Shabana Anjum; Anuradha; Amitabh Krishna
Oxytocin (OXT) is a nine amino acid neuropeptide produced in the hypothalamus and released by the posterior pituitary of the brain. OXT are mainly involved in neurotransmitter/neuro-modulatory function in central nervous system. Traditionally OXT was considered as female hormone due to its involvement in uterine contraction during parturition and milk ejection during lactation. But in males, OXT modulates sexual/mating, behaviour, ejaculation and participates in contractile activity of seminiferous tubules (ST) that helps in transfer of sperm to epididymis. Recent study provide an evidence that OXT plays an important role during peri-pubertal development and affects social behaviour by altering neural structure and function. It is now revealed that OXT modulates hypothalamic-pituitary-gonadal axis during puberty. Earlier study showed expression of OXT in gonads during puberty in male. However, recently OXT is also known to be involved in the in the regulation and release of gonadotropin releasing hormone (GnRH). Hormonal events play a significant role in brain-behaviour interactions. However, only limited studies are known about the mechanism by which OXT link with various behavioural activities of childhood, adolescence and adult life. The present review suggests involvement of oxitocinergic system in the regulation of HPG axis during pubertal development and social cognition in the mammals. © 2020 by Nova Science Publishers, Inc. All rights reserved.
Possible role of GnIH as a mediator between adiposity and impaired testicular function
(Frontiers Media S.A., 2016) Shabana Anjum; Amitabh Krishna; Kazuyoshi Tsutsui
The aim of the present study was to evaluate the roles of gonadotropin-inhibitory hormone (GnIH) as an endocrine link between increasing adiposity and impaired testicular function in mice. To achieve this, the effect of GnIH on changes in nutrients uptake and hormonal synthesis/action in the adipose tissue and testis was investigated simultaneously by in vivo study and separately by in vitro study. Mice were treated in vivo with different doses of GnIH for 8 days. In the in vitro study, adipose tissue and testes of mice were cultured with different doses of GnIH with or without insulin or LH for 24 h at 37°C. The GnIH treatment in vivo showed increased food intake, upregulation of glucose transporter 4 (GLUT4), and increased uptake of triglycerides (TGs) in the adipose tissue. These changes may be responsible for increased accumulation of fat in white adipose tissue, resulting in increase in the body mass. Contrary to the adipose tissue, treatment with GnIH both in vivo and in vitro showed decreased uptake of glucose by downregulation of glucose transporter 8 (GLUT8) expressions in the testis, which in turn resulted in the decreased synthesis of testosterone. The GnIH treatment in vivo also showed the decreased expression of insulin receptor protein in the testis, which may also be responsible for the decreased testicular activity in the mice. These findings thus suggest that GnIH increases the uptake of glucose and TGs in the adipose tissue, resulting in increased accumulation of fat, whereas simultaneously in the testis, GnIH suppressed the GLUT8-mediated glucose uptake, which in turn may be responsible for decreased testosterone synthesis. This study thus demonstrates GnIH as mediator of increasing adiposity and impaired testicular function in mice. © 2016 Anjum, Krishna and Tsutsui.
RF-amide related peptide-3 (RFRP-3): a novel neuroendocrine regulator of energy homeostasis, metabolism, and reproduction
(Springer Science and Business Media B.V., 2021) Shabana Anjum; Muhammad Nasir Khan Khattak; Kazuyoshi Tsutsui; Amitabh Krishna
A hypothalamic neuropeptide, RF-amide related peptide-3 (RFRP-3), the mammalian ortholog of the avian gonadotropin-inhibitory hormone (GnIH) has inhibitory signals for reproductive axis via G-protein coupled receptor 147 in mammals. Moreover, RFRP-3 has orexigenic action but the mechanism involved in energy homeostasis and glucose metabolism is not yet known. Though, the RFRP-3 modulates orexigenic action in co-operation with other neuropeptides, which regulates metabolic cues in the hypothalamus. Administration of GnIH/RFRP-3 suppresses plasma luteinizing hormone, at the same time stimulates feeding behavior in birds and mammals. Likewise, in the metabolically deficient conditions, its expression is up-regulated suggests that RFRP-3 contributes to the integration of energy balance and reproduction. However, in many other metabolic conditions like induced diabetes and high-fat diet obesity, etc. its role is still not clear while, RFRP-3 induces the glucose homeostasis by adipocytes is reported. The physiological role of RFRP-3 in metabolic homeostasis and the metabolic effects of RFRP-3 signaling in pharmacological studies need a detailed discussion. Further studies are required to find out whether RFRP-3 is associated with restricted neuroendocrine function observed in type II diabetes mellitus, aging, or sub-fertility. In this context, the current review is focused on the role of RFRP-3 in the above-mentioned mechanisms. Studies from search engines including PubMed, Google Scholar, and science.gov are included after following set inclusion/exclusion criteria. As a developing field few mechanisms are still inconclusive, however, based on the available information RFRP-3 seems to be a putative tool in future treatment strategies towards metabolic disease. © 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature.