Browsing by Author "Alka Sharma"

Now showing 1 - 14 of 14

Autophagy in hypoxic ovary
(Birkhauser Verlag AG, 2019) Anil Kumar Yadav; Pramod K. Yadav; Govind R. Chaudhary; Meenakshi Tiwari; Anumegha Gupta; Alka Sharma; Ashutosh N. Pandey; Ajai K. Pandey; Shail K. Chaube
Oxygen deprivation affects human health by modulating system as well as cellular physiology. Hypoxia generates reactive oxygen species (ROS), causes oxidative stress and affects female reproductive health by altering ovarian as well as oocyte physiology in mammals. Hypoxic conditions lead to several degenerative changes by inducing various cell death pathways like autophagy, apoptosis and necrosis in the follicle of mammalian ovary. The encircling somatic cell death interrupts supply of nutrients to the oocyte and nutrient deprivation may result in the generation of ROS. Increased level of ROS could induce granulosa cells as well as oocyte autophagy. Although autophagy removes damaged proteins and subcellular organelles to maintain the cell survival, irreparable damages could induce cell death within intra-follicular microenvironment. Hypoxia-induced autophagy is operated through 5′ AMP activated protein kinase–mammalian target of rapamycin, endoplasmic reticulum stress/unfolded protein response and protein kinase C delta–c-junN terminal kinase 1 pathways in a wide variety of somatic cell types. Similar to somatic cells, we propose that hypoxia may induce granulosa cell as well as oocyte autophagy and it could be responsible at least in part for germ cell elimination from mammalian ovary. Hypoxia-mediated germ cell depletion may cause several reproductive impairments including early menopause in mammals. © 2019, Springer Nature Switzerland AG.
Correction: Intervention of Phytochemicals During Endometriosis and Their Conceivable Mechanisms (Revista Brasileira de Farmacognosia, (2023), 33, 6, (1126-1140), 10.1007/s43450-023-00426-2)
(Springer Science and Business Media Deutschland GmbH, 2023) Safiya Ayesha; Alka Sharma; Jayhind Kumar Chauhan; Vivek Pandey; Garima Tripathi; Pawan K. Dubey; Anima Tripathi
The graphical abstract in the original online version of this article was incorrect. It has been corrected. © 2023, The Author(s) under exclusive licence to Sociedade Brasileira de Farmacognosia.
Cyclic nucleotide phosphodiesterase inhibitors: possible therapeutic drugs for female fertility regulation
(Elsevier B.V., 2020) Anumegha Gupta; Ashutosh N. Pandey; Alka Sharma; Meenakshi Tiwari; Pramod K. Yadav; Anil K. Yadav; Ajai K. Pandey; Tulsidas G. Shrivastav; Shail K. Chaube
Cyclic nucleotide phosphodiesterases (PDEs) are group of enzymes responsible for the hydrolysis of cyclic adenosine 3′, 5′ monophosphate (cAMP) and cyclic guanosine 3′, 5′ monophosphate (cGMP) levels in wide variety of cell types. These PDEs are detected in encircling granulosa cells or in oocyte with in follicular microenvironment and responsible for the decrease of cAMP and cGMP levels in mammalian oocytes. A transient decrease of cAMP level initiates downstream pathways to cause spontaneous meiotic resumption from diplotene arrest and induces oocyte maturation. The nonspecific PDE inhibitors (caffeine, pentoxifylline, theophylline, IBMX etc.) as well as specific PDE inhibitors (cilostamide, milrinone, org 9935, cilostazol etc.) have been used to elevate cAMP level and inhibit meiotic resumption from diplotene arrest and oocyte maturation, ovulation, fertilization and pregnancy rates both in vivo as well as under in vitro culture conditions. The PDEs inhibitors are used as powerful experimental tools to demonstrate cyclic nucleotide mediated changes in ovarian functions and thereby fertility. Indeed, non-hormonal nature and reversible effects of nonspecific as well as specific PDE inhibitors hold promise for the development of novel therapeutic drugs for female fertility regulation. © 2020
Germ cell depletion from mammalian ovary: Possible involvement of apoptosis and autophagy
(BioMed Central Ltd., 2018) Pramod K. Yadav; Meenakshi Tiwari; Anumegha Gupta; Alka Sharma; Shilpa Prasad; Ashutosh N. Pandey; Shail K. Chaube
Mammalian ovary contains millions of germ cells during embryonic life but only few of them are culminated into oocytes that achieve meiotic competency just prior to ovulation. The majority of germ cells are depleted from ovary through several pathways. Follicular atresia is one of the major events that eliminate germ cells from ovary by engaging apoptotic as well as non-apoptotic pathways of programmed cell death. Apoptosis is characterized by several morphological changes that include cell shrinkage, nuclear condensation, membrane blebbing and cytoplasmic fragmentation by both mitochondria- as well as death receptor-mediated pathways in encircling granulosa cells and oocyte. Although necroapoptosis have been implicated in germ cell depletion, autophagy seems to play an active role in the life and death decisions of ovarian follicles. Autophagy is morphologically characterized by intracellular reorganization of membranes and increased number of autophagic vesicles that engulf bulk cytoplasm as well as organelles. Autophagy begins with the encapsulation of cytoplasmic constituents in a membrane sac known as autophagosomes. The autophagic vesicles are then destroyed by the lysosomal enzymes such as hydrolases that results in follicular atresia. It seems that apoptosis as well as autophagy could play active roles in germ cells depletion from ovary. Hence, it is important to prevent these two pathways in order to retain the germ cells in ovary of several mammalian species that are either threatened or at the verge of extinction. The involvement of apoptosis and autophagy in germ cell depletion from mammalian ovary is reviewed and possible pathways have been proposed. © 2018 The Author(s).
Identification and molecular characterization of genes modulating progression of an oocyte from M-I to M-II in rat ovary
(John Wiley and Sons Inc, 2024) Alka Sharma; Pawan K. Dubey; Pradeep Kumar; Kavindra Nath Tiwari; Anima Tripathi
Background: To achieve oocyte competence for successful fertilization, bidirectional communication between oocyte and granulosa cells is crucial. The acquisition of meiotic competency in oocyte is facilitated by various regulatory genes however, expression pattern of these genes is not well documented during meiotic transition from Metaphase-I to Metaphase-II stage. Therefore, the present research analyzed the expression pattern of regulatory genes that are involved in the transition from M-I to M-II stages in rat oocyte. Methods: The analysis of the data was conducted by applying an array of bioinformatic tools. The investigation of gene group interactions was carried out by employing the STRING database, which relies on co-expression information. The gene ontology (GO) analysis was performed utilizing the comparative GO database. Functional annotation for GO and pathway enrichment analysis were performed for genes involved in networking. The GO obtained through computational simulations was subsequently validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR) analysis. Results: The findings of our study suggest that there is a distinct gene expression pattern in both the oocyte and granulosa cells. This pattern indicates that oocyte-secreted factors, such as BMP15 and GDF9, play a crucial role in regulating the progression of the meiotic cell cycle from the M-I to M-II stages. We have also examined the level of mRNA expression of genes including CYP11A1, CYP19A1, and STAR, which are crucial for the steroidogenesis. Conclusions: It is fascinating to observe that the oscillatory pattern of specific key genes may hold significance in the process of in vitro oocyte maturation, specifically during the transition from the M-I to M-II stage. It might be useful for determining biomarker genes and potential pathways that play a role in attaining oocyte competency, thereby aiding in the assessment of oocyte quality for the purpose of achieving successful fertilization. © 2024 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
Impact of stress on female reproductive health disorders: Possible beneficial effects of shatavari (Asparagus racemosus)
(Elsevier Masson SAS, 2018) Ajai K Pandey; Anumegha Gupta; Meenakshi Tiwari; Shilpa Prasad; Ashutosh N. Pandey; Pramod K. Yadav; Alka Sharma; Kankshi Sahu; Syed Asrafuzzaman; Doyil T. Vengayil; Tulsidas G. Shrivastav; Shail K Chaube
Stress is deeply rooted in the society and women are frequently exposed to psychological, physical and physiological stressors. Psychological stress disturbs reproductive health by inducing generation of reactive oxygen species (ROS) and thereby oxidative stress (OS). The increased OS may affect physiology of ovary, oocyte quality and cause female reproductive health disorders. To overcome stress-mediated reproductive health disorders in women, shatavari (Asparagus racemosus) is frequently recommended in Ayurvedic system of medicine. Although shatavari is one of the major health tonics and most popular rasayana drugs to treat reproductive ailments of women, underlying mechanism of shatavari action at the level of ovary remains poorly understood. Based on the existing studies, we propose that shatavari may improve female reproductive health complications including hormonal imbalance, polycystic ovarian syndrome (PCOS), follicular growth and development, oocyte quality and infertility possibly by reducing OS level and increasing antioxidants level in the body. Further studies are required to elucidate the mechanism of shatavari actions at the level of ovary and oocyte that directly impacts the reproductive health of women. © 2018 Elsevier Masson SAS
Intervention of Phytochemicals During Endometriosis and Their Conceivable Mechanisms
(Springer Science and Business Media Deutschland GmbH, 2023) Safiya Ayesha; Alka Sharma; Jayhind Kumar Chauhan; Vivek Pandey; Garima Tripathi; Pawan K. Dubey; Anima Tripathi
Endometriosis is a chronic and complex endocrine disorder that affects women of reproductive age. This syndrome is benign and is characterized by a combination of ovarian dysfunction and estrogen dependency symptoms, as well as pain and infertility. The most commonly stated symptoms include dysmenorrhea, significant dyspareunia, dyschezia, and dysuria. It is a severe public health issue. The prevalence rate is quite high and continues to rise on a daily basis. Starting with its diagnosis, pathophysiology, repercussions, and treatment options, there are numerous areas of disagreement. This study aims to provide an overview of the development of endometriosis diagnosis, symptoms, risk factors, etiology, medicinal plants, phytochemicals, and treatment, with a focus on research and the creation of novel therapeutic strategies. We conclude by making predictions and recommendations for the future of endometriosis-related research and prospective therapy approaches. Graphical Abstract: [Figure not available: see fulltext.] © 2023, The Author(s) under exclusive licence to Sociedade Brasileira de Farmacognosia.
Journey of oocyte from metaphase-I to metaphase-II stage in mammals
(Wiley-Liss Inc., 2018) Alka Sharma; Meenakshi Tiwari; Anumegha Gupta; Ashutosh N. Pandey; Pramod K. Yadav; Shail K. Chaube
In mammals, journey from metaphase-I (M-I) to metaphase-II (M-II) is important since oocyte extrude first polar body (PB-I) and gets converted into haploid gamete. The molecular and cellular changes associated with meiotic cell cycle progression from M-I to M-II stage and extrusion of PB-I remain ill understood. Several factors drive oocyte meiosis from M-I to M-II stage. The mitogen-activated protein kinase3/1 (MAPK3/1), signal molecules and Rho family GTPases act through various pathways to drive cell cycle progression from M-I to M-II stage. The down regulation of MOS/MEK/MAPK3/1 pathway results in the activation of anaphase-promoting complex/cyclosome (APC/C). The active APC/C destabilizes maturation promoting factor (MPF) and induces meiotic resumption. Several signal molecules such as, c-Jun N-terminal kinase (JNK2), SENP3, mitotic kinesin-like protein 2 (MKlp2), regulator of G-protein signaling (RGS2), Epsin2, polo-like kinase 1 (Plk1) are directly or indirectly involved in chromosomal segregation. Rho family GTPase is another enzyme that along with cell division cycle (Cdc42) to form actomyosin contractile ring required for chromosomal segregation. In the presence of origin recognition complex (ORC4), eccentrically localized haploid set of chromosomes trigger cortex differentiation and determine the division site for polar body formation. The actomyosin contractile activity at the site of division plane helps to form cytokinetic furrow that results in the formation and extrusion of PB-I. Indeed, oocyte journey from M-I to M-II stage is coordinated by several factors and pathways that enable oocyte to extrude PB-I. Quality of oocyte directly impact fertilization rate, early embryonic development, and reproductive outcome in mammals. © 2018 Wiley Periodicals, Inc.
Meiotic Instability Generates a Pathological Condition in Mammalian Ovum
(Springer, 2021) Karuppanan V. Premkumar; Shilpa Prasad; Meenakshi Tiwari; Ashutosh N. Pandey; Anumegha Gupta; Alka Sharma; Pramod K. Yadav; Anil K. Yadav; Devendra K. Pandey; Ajai K. Pandey; Shail K. Chaube
Maintenance of metaphase-II (M-II) arrest in ovum is required to present itself as a right gamete for successful fertilization in mammals. Surprisingly, instability of meiotic cell cycle results in spontaneous exit from M-II arrest, chromosomal scattering and incomplete extrusion of second polar body (PB-II) without forming pronuclei so called abortive spontaneous ovum activation (SOA). It remains unclear what causes meiotic instability in freshly ovulated ovum that results in abortive SOA. We propose the involvement of various signal molecules such as reactive oxygen species (ROS), cyclic 3′,5′ adenosine monophosphate (cAMP) and calcium (Ca2+) in the induction of meiotic instability and thereby abortive SOA. These signal molecules through their downstream pathways modulate phosphorylation status and activity of cyclin dependent kinase (cdk1) as well as cyclin B1 level. Changes in phosphorylation status of cdk1 and its activity, dissociation and degradation of cyclin B1 destabilize maturation promoting factor (MPF). The premature MPF destabilization and defects in other cell cycle regulators possibly cause meiotic instability in ovum soon after ovulation. The meiotic instability results in a pathological condition of abortive SOA and deteriorates ovum quality. These ova are unfit for fertilization and limit reproductive outcome in several mammalian species including human. Therefore, global attention is required to identify the underlying causes in greater details in order to address the problem of meiotic instability in ova of several mammalian species icluding human. Moreover, these activated ova may be used to create parthenogenetic embryonic stem cell lines in vitro for the use in regenerative medicine. Graphical abstract[Figure not available: see fulltext.] © 2020, Springer Science+Business Media, LLC, part of Springer Nature.
Necroptosis in stressed ovary
(BioMed Central Ltd., 2019) Govind R. Chaudhary; Pramod K. Yadav; Anil K. Yadav; Meenakshi Tiwari; Anumegha Gupta; Alka Sharma; Ashutosh N. Pandey; Ajai K. Pandey; Shail K. Chaube
Stress is deeply rooted in the modern society due to limited resources and large competition to achieve the desired goal. Women are more frequently exposed to several stressors during their reproductive age that trigger generation of reactive oxygen species (ROS). Accumulation of ROS in the body causes oxidative stress (OS) and adversely affects ovarian functions. The increased OS triggers various cell death pathways in the ovary. Beside apoptosis and autophagy, OS trigger necroptosis in granulosa cell as well as in follicular oocyte. The OS could activate receptor interacting protein kinase-1(RIPK1), receptor interacting protein kinase-3 (RIPK3) and mixed lineage kinase domain-like protein (MLKL) to trigger necroptosis in mammalian ovary. The granulosa cell necroptosis may deprive follicular oocyte from nutrients, growth factors and survival factors. Under these conditions, oocyte becomes more susceptible towards OS-mediated necroptosis in the follicular oocytes. Induction of necroptosis in encircling granulosa cell and oocyte may lead to follicular atresia. Indeed, follicular atresia is one of the major events responsible for the elimination of majority of germ cells from cohort of ovary. Thus, the inhibition of necroptosis could prevent precautious germ cell depletion from ovary that may cause reproductive senescence and early menopause in several mammalian species including human. © 2019 The Author(s).
Necrosis and necroptosis in germ cell depletion from mammalian ovary
(Wiley-Liss Inc., 2019) Govind R. Chaudhary; Pramod K. Yadav; Anil K. Yadav; Meenakshi Tiwari; Anumegha Gupta; Alka Sharma; Kankshi Sahu; Ashutosh N. Pandey; Ajai K. Pandey; Shail K. Chaube
The maximum number of germ cells is present during the fetal life in mammals. Follicular atresia results in rapid depletion of germ cells from the cohort of the ovary. At the time of puberty, only a few hundred (<1%) germ cells are either culminated into oocytes or further get eliminated during the reproductive life. Although apoptosis plays a major role, necrosis as well as necroptosis, might also be involved in germ cell elimination from the mammalian ovary. Both necrosis and necroptosis show similar morphological features and are characterized by an increase in cell volume, cell membrane permeabilization, and rupture that lead to cellular demise. Necroptosis is initiated by tumor necrosis factor and operated through receptor interacting protein kinase as well as mixed lineage kinase domain-like protein. The acetylcholinesterase, cytokines, starvation, and oxidative stress play important roles in necroptosis-mediated granulosa cell death. The granulosa cell necroptosis directly or indirectly induces susceptibility toward necroptotic or apoptotic cell death in oocytes. Indeed, prevention of necrosis and necroptosis pathways using their specific inhibitors could enhance growth/differentiation factor-9 expression, improve survivability as well as the meiotic competency of oocytes, and prevent decline of reproductive potential in several mammalian species and early onset of menopause in women. This study updates the information and focuses on the possible involvement of necrosis and necroptosis in germ cell depletion from the mammalian ovary. © 2018 Wiley Periodicals, Inc.
Role of granulosa cell mitogen-activated protein kinase 3/1 in gonadotropin-mediated meiotic resumption from diplotene arrest of mammalian oocytes
(Taylor and Francis Ltd, 2018) Kankshi Sahu; Anumegha Gupta; Alka Sharma; Meenakshi Tiwari; Ashutosh N. Pandey; Shilpa Prasad; Pramod K. Yadav; Ajai K. Pandey; Tulsidas G. Shrivastav; Shail K. Chaube
In mammals, preovulatory oocytes are encircled by several layers of granulosa cells (GCs) in follicular microenvironment. These follicular oocytes are arrested at diplotene arrest due to high level of cyclic nucleotides from encircling GCs. Pituitary gonadotropin acts at the level of encircling GCs and increases adenosine 3′,5′-cyclic monophosphate (cAMP) and guanosine 3′,5′-cyclic monophosphate (cGMP) and activates mitogen-activated protein kinase 3/1 (MAPK3/1) signaling pathway. The MAPK3/1 disrupts the gap junctions between encircling GCs and oocyte. The disruption of gap junctions interrupts the transfer of cyclic nucleotides to the oocyte that results a drop in intraoocyte cAMP level. A transient decrease in oocyte cAMP level triggers maturation promoting factor (MPF) destabilization. The destabilized MPF finally triggers meiotic resumption from diplotene arrest in follicular oocyte. Thus, MAPK3/1 from GCs origin plays important role in gonadotropin-mediated meiotic resumption from diplotene arrest in follicular oocyte of mammals. © 2018, © 2018 Informa UK Limited, trading as Taylor & Francis Group.
Role of Mitogen Activated Protein Kinase and Maturation Promoting Factor During the Achievement of Meiotic Competency in Mammalian Oocytes
(Wiley-Liss Inc., 2018) Meenakshi Tiwari; Anumegha Gupta; Alka Sharma; Shilpa Prasad; Ashutosh N. Pandey; Pramod K. Yadav; Ajai K. Pandey; Tulsidas G. Shrivastav; Shail K. Chaube
The oocyte quality remains as one of the major problems associated with poor in vitro fertilization (IVF) rate and assisted reproductive technology (ART) failure worldwide. The oocyte quality is dependent on its meiotic maturation that begins inside the follicular microenvironment and gets completed at the time of ovulation in most of the mammalian species. Follicular oocytes are arrested at diplotene stage of first meiotic prophase. The resumption of meiosis from diplotene arrest, progression through metaphase-I (M-I) and further arrest at metaphase-II (M-II) are important physiological requirements for the achievement of meiotic competency in mammalian oocytes. The achievement of meiotic competency is dependent upon cyclic stabilization/destabilization of maturation promoting factor (MPF). The mitogen-activated protein kinase3/1 (MAPK3/1) modulates stabilization/destabilization of MPF in oocyte by interacting either with signal molecules, transcription and post-transcription factors in cumulus cells or cytostatic factors (CSFs) in oocyte. MPF regulates meiotic cell cycle progression from diplotene arrest to M-II arrest and directly impacts oocyte quality. The MAPK3/1 activity is not reported during spontaneous meiotic resumption but its activity in cumulus cells is required for gonadotropin-induced oocyte meiotic resumption. Although high MAPK3/1 activity is required for the maintenance of M-II arrest in several mammalian species, its cross-talk with MPF remains to be elucidated. Further studies are required to find out the MAPK3/1 activity and its impact on MPF destabilization/stabilization during achievement of meiotic competency, an important period that decides oocyte quality and directly impacts ARTs outcome in several mammalian species including human. J. Cell. Biochem. 119: 123–129, 2018. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.
Shatavarin-IV rescues the Di (2-ethylhexyl) phthalate (DEHP) induced oxidative stress in rat granulosa cells in vitro
(Elsevier Inc., 2024) Vivek Pandey; Alka Sharma; Sonal Tiwari; Yashvant Patel; Jayhind Kumar Chauhan; Safiya Ayesha; Alakh N. Sahu; Rashmi Gupta; Anima Tripathi; Pawan K. Dubey
Studies provide notable evidence that oxidative stress (OS) mediated reactive oxygen species (ROS) disturb reproductive health. We have shown in our previous publication that exposure of Di-(2-ethylhexyl) phthalate (DEHP), induces OS mediated ROS generation which inhibits steroid synthesis. In the present study, we demonstrated the ameliorative/protective effects of one of the steroidal saponins, i.e., Shatavarin-IV, isolated from the roots of Asparagus racemosus against DEHP induced OS in rat granulosa cells. Granulosa cells were exposed with DEHP alone (400 μM), Shatavarin-IV alone (8 μg/ml), and a combination of DEHP + Shatavarin-IV (400 μM + 8 μg/ml) in vitro for 24 hrs. Intracellular ROS, OS/hypoxia, mitochondrial membrane potential, steroid-responsive genes expression were analyzed. The results revealed that the effective dose of DEHP (400 µg) significantly increased OS compared to the control by increasing ROS levels, mitochondrial membrane potential, and β-galactosidase activity with a higher level of apoptotic genes (Bax, Caspase-3) expression at mRNA level. Further, DEHP significantly (p < 0.05) reduced mRNA expression of steroidogenic responsive genes (StAR, CYP17A1, and CYP19A1) in granulosa cells treated with above combination compared to control. Interestingly, co-treatment of DEHP + Shatavarin-IV significantly suppressed the DEHP induced OS, ROS, β-galactosidase levels and enhanced steroidogeneic and apoptotic gene expression activities, which suggests that Shatavarin-IV rescued DEHP-induced changes that may useful for the prevention of DEHP- induced reproductive toxicity. © 2024 Elsevier Inc.