Browsing by Author "Amitabh Krishna"

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Adiponectin and Chemerin: Contrary Adipokines in Regulating Reproduction and Metabolic Disorders
(SAGE Publications Inc., 2018) Anusha Singh; Mayank Choubey; Puran Bora; Amitabh Krishna
Metabolic disorders such as obesity and type 2 diabetes are one of the most familiar risk factors in the present time among every age-group. It is associated with altered levels of adipokines such as adiponectin, chemerin, leptin, resistin, visfatin, and so on. Adiponectin is one of the adipocyte-specific protein with novel applications pertaining to metabolism by promoting insulin sensitivity and regulating glucose and fatty acid catabolism, while chemerin is considered as an inhibitor of insulin signaling and glucose catabolism. Other than these established functions, both the adipokines are intimately involved in coordinating reproductive activities, but they exhibit contrary functions. This review is an amalgamation of recent information related to adiponectin and chemerin in male and female reproduction and further its association with metabolism-related reproductive disorders. The direct effect of adiponectin and chemerin on various reproductive parameters has been investigated, but there was a rampant failure to account for in vivo data which gives a broad outlook on the regulatory mechanism of both adiponectin and chemerin related to male and female reproductive functions. Adiponectin is known to promote gonadal activities, while chemerin exerts antigonadal actions. Recent research suggests that high chemerin/low adiponectin ratio plays a vital role in causing dyslipidemia and metabolic syndrome in patients. The dysregulated ratio of adiponectin to chemerin during various metabolic disorders makes it really worthy in relation to an application for therapeutics. Still, a lot regarding both the adipokines has to be explored and brought forward in order to deal with therapeutics of metabolism-related reproductive disorders. © The Author(s) 2018.
Adiponectin/AdipoRs signaling as a key player in testicular aging and associated metabolic disorders
(Academic Press Inc., 2021) Mayank Choubey; Ashutosh Ranjan; Amitabh Krishna
Aging undergoes serious worsening of peripheral organs and vital physiological processes including reproductive performances. Altered white adipose tissue and adipocyte functioning during aging results in ectopic lipid storage/obesity or metabolic derangements, leading to insulin resistance state. Eventually, accelerating cellular senescence thereby enhancing the high risk of age-associated metabolic alterations. Such alterations may cause derangement of numerous physiologically active obesity hormones, known as “adipokines.” Specifically, adiponectin exhibits insulin sensitizing action causing anti-aging and anti-obesity effects via activation of adiponectin receptors (AdipoRs). The male reproductive physiology from reproductive mature stage to advanced senescent stage undergoes insidious detrimental changes. The mechanisms by which testicular functions decline with aging remain largely speculative. Adiponectin has also recently been shown to regulate metabolism and longevity signaling thus prolonging lifespan. Therefore, the strategy for activating adiponectin/AdipoRs signaling pathways are expected to provide a solid basis for the prevention and treatment of aging and obesity-associated reproductive dysfunctions, as well as for ensuring healthy reproductive longevity in humans. © 2021 Elsevier Inc.
Adiposity associated changes in serum glucose and adiponectin levels modulate ovarian steroidogenesis during delayed embryonic development in the fruit bat, Cynopterus sphinx
(Academic Press Inc., 2018) Anuradha; Amitabh Krishna
The aim of the present study was to evaluate the mechanism by which embryonic development in Cynopterus sphinx is impaired during the period of increased accumulation of white adipose tissue during winter scarcity of food. The change in the mass of white adipose tissue during adipogenesis showed significant positive correlation with the circulating glucose level. But increase in circulating glucose level during the adipogenesis showed negative correlation with circulating progesterone and adiponectin levels. The in vivo study showed increased glucose uptake by the adipose tissue during adipogenesis due to increased expression of insulin receptor (IR) and glucose transporter (GLUT) 4 proteins. This study showed decline in the adiponectin level during fat accumulation. In the in vitro study, ovary treated with high doses of glucose showed impaired progesterone synthesis. This is due to decreased glucose uptake mediated decrease in the expression of luteinizing hormone-receptor, steroidogenic acute regulatory protein, IR, GLUT4 and AdipoR1 proteins. But the ovary treated with adiponectin either alone or with higher concentration of glucose showed improvement in progesterone synthesis due to increased expression of IR, GLUT4 and AdipoR1 mediated increased glucose uptake. In conclusion, increased circulating glucose level prior to winter dormancy preferably transported to white adipose tissue for fat accumulation diverting glucose away from the ovary. Consequently the decreased availability of adiponectin and glucose to the ovary and utero-embryonic unit may be responsible for impaired progesterone synthesis and delayed embryonic development. The delayed embryonic development in Cynopterus sphinx may have evolved, in part, as a mechanism to prevent pregnancy loss during the period of decreased energy availability. © 2018 Elsevier Inc.
Adiposity associated rise in leptin impairs ovarian activity during winter dormacy in vespertilinoid bat, Scotophilus heathi
(2007) Raj Kamal Srivastava; Amitabh Krishna
The aim of the study was to evaluate the seasonal variation in serum leptin levels in a natural population of the female bat, Scotophilus heathi and their relationship to the changes in the body mass, serum insulin level, and ovarian activity. Circulating leptin level varied significantly over the season and correlated positively with the changes in body mass, and circulating insulin and androstenedione (A4) levels. Circulating leptin concentrations showed two peaks; one coincides with the maximum fat accumulation prior to winter dormancy, whereas the second shorter peak coincides with late pregnancy. The in vivo study in S. heathi showed that the increased circulating leptin level during winter dormancy coincides with the decreased expression of ovarian steroidogenic acute regulatory (StAR) protein, and low circulating estradiol (E2) level. At the same time, increased circulating leptin level coincides with increased expression of ovarian insulin receptor and high circulating A4 level. The low circulating leptin level during preovulatory period coincides with the increase in StAR protein but decrease in insulin receptor protein. The in vitro study confirmed the in vivo observations of inhibitory effect of leptin on LH induced StAR expression and E2 production, whereas the stimulatory effect of leptin (high dose) on LH induced expression of insulin receptor protein and A4 production. However, pharmacological dose of leptin produced inhibitory effect on the expression of insulin receptor protein. The results of the present study thus suggest that high circulating leptin level during winter dormancy promotes adiposity and impairs ovarian activity by suppressing StAR-mediated E2 production as well as by enhancing insulin receptor-mediated A4 synthesis thereby contributing anovulatory condition of delayed ovulation in S. heathi. © 2007 Society for Reproduction and Fertility.
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.
Asprosin promotes steroidogenesis and spermatogenesis with improved glucose metabolism in adult mice testis
(John Wiley and Sons Inc, 2022) Sangeeta Maurya; Amitabh Krishna; Bechan Lal; Ajit Singh
Asprosin is an orexigenic adipokine that regulates appetite and glucose homeostasis in mammals. To date, only fragmentary findings are reported regarding its role in testicular activities. In the current investigation, immunolocalization and direct action of asprosin in adult mice testis was evaluated. Immunohistochemical and immunoblot studies were performed to analyse the testicular expression of asprosin. Intratesticular treatment of asprosin (0.1 μg and 1.0 μg per testis) was given to evaluate its direct action on testicular functions. Sertoli and Leydig cells were found to be immuno-positive for asprosin. Intratesticular administration of asprosin resulted into a significant increase in glucose and lactate levels along with enhanced expression of asprosin receptor OLFR734, insulin receptor (IR), glucose transporter 8 (GLUT 8), lactate dehydrogenase (LDH) activity and monocorboxylate transporters (MCT2 and 4). In addition, asprosin administration increased the testicular expression of cell proliferation (proliferating cell nuclear antigen: PCNA), cell survival (B cell lymphoma 2: Bcl2) and decreased germ cell apoptosis (Cysteine aspartic acid protease 3: Caspase 3) leading to increased sperm counts. Further, asprosin treatment resulted into increased level of total cholesterol, testosterone and steroidogenic markers (steroidogenic acute regulatory protein: StAR; 3beta-hydroxysteroid dehydrogenases: 3β HSD and 17beta-hydroxysteroid dehydrogenases: 17β HSD). Asprosin treatment promotes testicular glucose uptake and lactate synthesis to provide energy for steroidogenesis and spermatogenesis. The significant correlation between the asprosin-induced increased IR expression and increased testosterone, glucose and lactate levels suggests its role in increased survival and proliferation but decrease in germ cell apoptosis. This study proposed asprosin's role as an autocrine/paracrine regulator of testicular functions in adult mice. © 2022 Wiley-VCH GmbH.
Asynchrony of the reproductive organs of the male vespertilionid bat, Scotophilus heathi: Role of gonadotrophins
(1999) Amitabh Krishna; Kavita Singh
Changes in the LH-cells of the anterior pituitary in relation to the reproductive cycle in the male Scotophilus heathi (Hotsfield, 1831) are described. Immunocytochemical studies of the pituitary suggested two annual peaks of LH accumulation and release each associated with a period of active spermatogenesis and testosterone secretion. Further, in vitro study showed differences in testicular responsiveness to LH stimulation during November (a period of active spermatogenesis) and December (winter dormancy). Present study further showed that FSH is also capable of stimulating androgen secretion from the testis. Testicular FSH responsiveness varies from recrudescence to winter dormancy and this may be responsible for maintaining high circulating androstenedione production in S. heathi during this period.
Carnitine-mediated antioxidant enzyme activity and Bcl2 expression involves peroxisome proliferator-activated receptor-γ coactivator-1α in mouse testis
(CSIRO, 2017) Vikas Kumar Roy; Rachna Verma; Amitabh Krishna
The protective effects of carnitine have been attributed to inhibition of apoptosis, alleviating oxidative stress and DNA repair mechanism by decreasing oxidative radicles. Carnitine also increases mitochondrial biogenesis via peroxisome proliferator-activated receptor-γ coactivator-1α (PGC1α). The role of carnitine in testicular PGC1α expression has not been documented. We hypothesised that the effects of carnitine as an antioxidant, inhibitor of apoptosis and controller of steroidogenesis in mouse testis may involve PGC1α as a regulator. The present study was designed to evaluate the localisation of PGC1α and the effects of carnitine treatment on the expression of PGC1α, Bcl2 and antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx)) in mouse testis and serum testosterone concentrations. PGC1α was primarily immunolocalised to the Leydig cells and primary spermatocytes. Western blot analysis showed that carnitine (50mgkg-1 and 100mgkg-1 for 7 days) significantly increased PGC1α and Bcl2 expression in the testis in a dose-dependent manner. In addition, carnitine treatment significantly increased antioxidant enzyme (CAT, SOD and GPx) levels. The carnitine-induced changes in PGC1α in the testis were significantly correlated with changes in serum testosterone concentrations, as well as with changes in Bcl2 expression and antioxidant enzyme activity in the testis, as evaluated by electrophoresis. Therefore, the results of the present study suggest that carnitine treatment of mice increases PGC1α levels in the testis, which may, in turn, regulate steroidogenesis by increasing expression of Bcl2 and antioxidant enzymes. © 2017 CSIRO.
Cellular localization and seasonal variation of GnRH and Bradykinin in the ovary of Heteropneustes fossilis (Bloch.) during its reproductive cycle
(Elsevier Inc., 2024) Padmasana Singh; Vrajesh Tripathi; Raj Kamal Srivastava; Amitabh Krishna
The present study investigates the distribution and dynamics of gonadotropin-releasing hormone I (GnRH I) and bradykinin in the air-breathing catfish, Heteropneustes fossilis, in relation to the reproductive cycle. Changes in bradykinin, bradykinin B2-receptor, and ovarian GnRH I regulation were demonstrated during the reproductive cycle. The localization of GnRH I, bradykinin, and their respective receptors in the ovaries was investigated by immunohistochemistry, while their levels were quantified by slot/western blot followed by densitometry. GnRH I and its receptor were mainly localized in the cytoplasm of oocytes during the early previtellogenic phase. However, as the follicles grew larger, immunoreactivity was observed in the granulosa and theca cells of the late previtellogenic follicles. The ovaries showed significantly higher expression of GnRH I protein and its receptor during the early to mid-previtellogenic phase, suggesting their involvement in follicular development. Bradykinin and bradykinin B2-receptor showed a distribution pattern similar to that of GnRH I and its receptor. This study further suggested the possibility that bradykinin regulates GnRH I synthesis in the ovary. Thus, we show that the catfish ovary has a GnRH-bradykinin system and plays a role in follicular development and oocyte maturation in H. fossilis. © 2024
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.
Changes in bradykinin and bradykinin B2-receptor during estrous cycle of mouse
(2011) Padmasana Singh; Amitabh Krishna; Rajagopala Sridaran
The aim of the study was to investigate changes in the abundance of bradykinin and bradykinin B2-receptor in the ovary of mice during its estrous cycle. Changes in the abundance of bradykinin were correlated with changes in bradykinin B2-receptor in order to determine the functional significance of this peptide for follicular development, ovulation and luteinization. Bradykinin immunoreactivity was mainly observed in the granulosa cells of antral follicles, especially around the oocytes and lining the antral cavity during proestrus and estrus phases of the cycle. Recently formed corpora lutea showed mild immunoreactivity for both bradykinin and bradykinin B2-receptor. During diestrus 1 and diestrus 2, bradykinin and bradykinin B2-receptor immunostaining was mainly found in the corpora lutea and mildly in the antral follicles. Immunoblot analysis for bradykinin and bradykinin B2-receptor attained a peak during late evening in proestrus, which may be the time of the LH surge. Thereafter bradykinin and bradykinin B2-receptor declined sharply during the estrus phase. When the concentration of bradykinin was correlated with bradykinin B2-receptor throughout the estrous cycle, they showed strong positive correlation. Thus, this study indicates that the levels of bradykinin and bradykinin B2-receptor both simultaneously regulate estrous cycle and are important components for the reproductive process. © 2010 Elsevier GmbH.
Changes in glucose and carnitine levels and their transporters in utero-tubal junction in relation to sperm storage in the vespertilionid bat, Scotophilus heathi
(2013) Vikas Kumar Roy; Amitabh Krishna
Prolonged sperm storage over winter is a common feature of reproduction in some bats. In order to understand how sperm storage in the female genital tract of the vespertilionid bat, Scotophilus heathi (Greater yellow bat), is controlled, we compared concentrations of glucose and the fatty-acid carrier carnitine in the blood, and carnitine concentrations and levels of expression of the glucose transporters (GLUTs) and the carnitine transporter OCTN2 in the utero-tubal junction of females during non-storage (early winter) and sperm-storage periods (late winter-early spring). During the sperm-storage period (December-January) blood glucose concentrations declined, as did the expression of GLUT3 and GLUT5 in the utero-tubal junction. At the same time there were increases in the concentration of carnitine, and expression of OCTN2 and hormone-sensitive lipase (HSL) in the utero-tubal junction. These results suggest that prolonged sperm storage is enhanced by decreased glucose availability but increased free fatty acid availability at the site of sperm storage. Increases in expression of GLUT4 and GLUT8 in late winter suggest a role for these GLUTs in increasing sperm motility prior to fertilization. © 2013 Wiley Periodicals, Inc.
Changes in GnRH I, bradykinin and their receptors and GnIH in the ovary of Calotes versicolor during reproductive cycle
(Academic Press Inc., 2008) Padmasana Singh; Amitabh Krishna; Rajagopala Sridaran; Kazuyoshi Tsutsui
The aim of this study was to investigate changes in the abundance of gonadotrophin releasing hormone I (GnRH I) and GnRH I receptor in the ovary of Calotes versicolor during the reproductive cycle and correlate them with the changes in gonadotrophin inhibitory hormone (GnIH), bradykinin and bradykinin B2 receptor in order to understand their interaction during ovarian cycle. GnRH I, bradykinin and their receptors and GnIH, were localized immunohistochemically in the ovary. Relative intensity of these peptides was estimated from the contralateral ovary using slot/Western blot followed by densitometry. The immunostaining of GnRH I, bradykinin and their receptors and GnIH were localized in the granulosa cells of previtellogenic follicles and stroma cells, whereas in the peripheral part of the cytoplasm in oocytes of vitellogenic and ovulatory follicles. The GnRH I immunostaining was relatively higher in inactive phase, but was low during active preovulatory phase suggesting inverse correlation with circulating estradiol level. The study showed a positive correlation between the expression pattern of GnRH I and GnIH, but showed a negative correlation between GnIH with GnRH I receptor in the ovary. This study further suggests a possibility for bradykinin regulating GnRH I synthesis in the ovary. An increase in the immunostaining of both GnRH I and GnIH in the oocyte prior to ovulation suggests their involvement in the oocyte maturation. It is thus concluded that the ovary of C. versicolor possesses GnRH I-GnIH-bradykinin system and interaction between these neuropeptides may be involved in the regulation of follicular development and oocyte maturation. © 2008 Elsevier Inc.
Changes in the expression of HSL and OCTN2 in the female reproductive tract of the bat, Scotophilus heathii in relation to sperm storage
(2012) Vikas Kumar Roy; Amitabh Krishna
The aim of this study was to compare the changes in the expression of hormone sensitive lipase (HSL) and organic cation transporter 2 (OCTN2) in different regions of the female reproductive tract of bats (. Scotophilus heathii) during the period of sperm storage. Western blot analysis revealed that both HSL and OCTN2 showed elevated expression in the utero-tubal junction, the site of sperm storage, compared to the vagina, cervix and uterus. An immunohistochemical study showed localization of HSL and OCTN2 in the cytoplasm of luminal epithelial cells in the utero-tubal junction of . S. heathii, which suggests a role of fatty acids metabolism at the site of sperm storage. Furthermore, this study showed the presence OCTN2 immunostaining in the tail of stored sperm, which suggests a direct role of carnitine in sperm physiology. However, the role of carnitine in sperm storage needs further investigation. It is hypothesized that the utero-tubal junction may be finely tuned with fat depletion to support sperm storage in the female genital tract of . S. heathii. © 2011 Elsevier GmbH.
Comparative Effects of Estrogen and Phytoestrogen, Genistein on Testicular Activities of Streptozotocin-Induced Type 2 Diabetic Mice
(SAGE Publications Inc., 2019) Rachna Verma; Rusa Samanta; Amitabh Krishna
The aim of this study was to compare the effect of synthetic estrogen (E2) with a phytoestrogen and genistein in ameliorating type 2 diabetes mellitus (T2D)-mediated testicular dysfunction in mice. The streptozotocin (STZ)-induced type 2 diabetic mice were treated exogenously with either E2 or genistein for 2 durations and compared their effects on testicular activities, serum glucose, and insulin level. Type 2 diabetic mice treated with E2 for only short term (14 days) improved regressive changes in the testicular histology by increasing testosterone synthesis and improving insulin sensitivity, whereas those treated for longer duration (28 days) failed to improve testicular dysfunctions. On the other hand, genistein treated for both short- and long term was useful in improving T2D-induced adverse effects on testicular functions. This study further suggests that treatment with genistein improves spermatogenesis in type 2 diabetic mice by increasing insulin-induced formation of lactate and antioxidative enzymes, which contributes to prevent germ cell apoptosis. Thus, genistein can be used to ameliorate T2D-induced testicular dysfunction. © The Author(s) 2018.
Corrigendum: Effects of chronic Bhang (cannabis) administration on the reproductive system of male mice
(2011) Arnab Banerjee; Ajit Singh; Puneet Srivastava; Helen Turner; Amitabh Krishna
[No abstract available]
CURRENT STRATEGIES FOR MANAGEMENT OF GESTATIONAL DIABETES MELLITUS
(Nova Science Publishers, Inc., 2021) Anusha Singh; Amitabh Krishna
Gestational diabetes mellitus (GDM) is a common threat to the life of mother and fetus as a long-term risk of obesity and glucose intolerance in the offspring. Maternal hyperglycemia results in fetal problems like macrosomia, respiratory issues, hyperbilirubinemia, hyperglycemia, and many other complications. GDM is linked with several complications in pregnancy such as premature birth, preeclampsia, and difficult labor. The intricate pathophysiology of the disorder limits the management of this disorder. Medical and obstetrics management has been explored for the cure of GDM with the use of biomarkers at the maternal, placental, and fetal level. Long-term management strategies at both maternal and fetal levels are crucial for the mitigation of obesity-related complications in GDM. An effort of targeted therapeutics will probably open new avenues for its management covering new horizons in science. © 2021 by Nova Science Publishers, Inc.
Delayed embryonic development in the Indian short-nosed fruit bat, Cynopterus sphinx
(Elsevier GmbH, 2005) Karukayil J. Meenakumari; Amitabh Krishna
The unusual feature of the breeding cycle of Cynopterus sphinx at Varanasi is the significant variation in gestation length of the two successive pregnancies of the year. The aim of this study was to investigate whether the prolongation of the first pregnancy in C. sphinx is due to delayed embryonic development. The first (winter) pregnancy commences in late October and lasts until late March and has a gestation period of about 150 days. The second (summer) pregnancy commences in April and lasts until the end of July or early August with a gestation period of about 125 days. Changes in the size and weight of uterine cornua during the two successive pregnancies suggest retarded embryonic growth during November and December. Histological analysis during the period of retarded embryonic development in November and December showed a slow gastrulation process. The process of amniogenesis was particularly slow. When the embryos attained the early primitive streak stage, their developmental rate suddenly increased considerably. During the summer pregnancy, on the other hand, the process of gastrulation was much faster and proceeded quickly. A comparison of the pattern of embryonic development for 4 consecutive years consistently showed retarded or delayed embryonic development during November and December. The time of parturition and post-partum oestrus showed only a limited variation from 1 year to another. This suggests that delayed embryonic development in C. sphinx may function to synchronize parturition among females. The period of delayed embryonic development in this species clearly coincides with the period of fat deposition. The significance of this correlation warrants further investigation. © 2005 Elsevier GmbH. All rights reserved.
Direct action of adiponectin ameliorates increased androgen synthesis and reduces insulin receptor expression in the polycystic ovary
(Elsevier B.V., 2017) Anusha Singh; Puran Bora; Amitabh Krishna
Polycystic ovary syndrome (PCOS) is a common endocrine and metabolic disorder of reproductive age females, leading to infertility. Despite extensive research, the exact pathophysiology and treatment are lacking. The aim of the current study was to evaluate the direct role of adiponectin either alone or together with luteinizing hormone (LH) on sex hormone synthesis and changes in insulin receptor (IR) in the ovary of dehydroepiandrosterone (DHEA)–treated PCOS-mice. Immunohistochemical study showed decreased expression of adiponectin receptor (AdipoR1) in PCOS-ovary which correlated with increased synthesis of androgen and decreased expression of IR. The treatment with adiponectin with or without LH to PCOS-ovary in vitro caused significant decline in androgen synthesis and increase in IR. This study showed the direct role of adiponectin in ameliorating hyperandrogenism and reducing IR in the ovary of PCOS-mice. Thus adiponectin treatment may be a novel therapeutic strategy for combating PCOS. © 2017 Elsevier Inc.
Direct actions of adiponectin on changes in reproductive, metabolic, and anti-oxidative enzymes status in the testis of adult mice
(Academic Press Inc., 2019) Mayank Choubey; Ashutosh Ranjan; Puran S. Bora; Fátima Baltazar; Amitabh Krishna
Obesity is a major health problem that is linked to decreased sperm count. It is hypothesized that an obesity-associated reduction in adiponectin secretion may be responsible for impairment of spermatogenesis. Therefore, the aim of the study was to evaluate the direct role of adiponectin in spermatogenesis and steroid synthesis in adult mice. This study showed that adiponectin receptors (AdipoR1 and AdipoR2)were localized in Leydig cells and seminiferous tubules in the testis of adult mice. The result of the in vitro study showed the direct action of adiponectin on spermatogenesis by stimulating cell proliferation (PCNA)and survival (Bcl2)and by suppressing cell apoptosis. Treatment of testis with adiponectin also enhanced transport of the energetic substrates glucose and lactate to protect cells from undergoing apoptosis. Adiponectin treatment further showed a significant reduction in oxidative stress and nitric oxide. Our findings suggest that adiponectin effectively facilitates cell survival and proliferation, as well as protects from apoptosis. Thus, adiponectin treatment may be responsible for enhancing sperm counts. Interestingly, this study showed the stimulatory effect of adiponectin in spermatogenesis but showed an inhibitory effect on testosterone and estradiol synthesis in the testes. Based on the present study, it is hypothesized that systemic adiponectin treatment may be a promising therapeutic strategy for the improvement of spermatogenesis and sperm count. © 2018 Elsevier Inc.