Shail Chaube - Academia.edu (original) (raw)

Papers by Shail Chaube

In vitro cellular & developmental biology. Animal, 2015

The present study was aimed to find out whether roscovitine reduces phosphorylated Thr-161 of cyc... more The present study was aimed to find out whether roscovitine reduces phosphorylated Thr-161 of cyclin-dependent kinase 1 (Cdk1) level and induces egg apoptosis through Fas ligand (FasL)-mediated pathway. For this purpose, ovulated eggs were cultured in media 199 with or without various concentrations of roscovitine (0, 25, 50, 100, 200 μM) for 3 h in vitro. The morphological apoptotic changes, phosphorylation status of Cdk1, FasL concentration, caspase-8 and caspase-3 activities, and DNA fragmentation were analyzed. Data of the present study suggest that roscovitine significantly reduced Thr-161 phosphorylated Cdk1 level without altering the total level of Cdk1 and induced cytoplasmic fragmentation, a morphological apoptotic feature in a concentration-dependent manner. The roscovitine-induced cytoplasmic fragmentation was associated with increased FasL concentration. The increased FasL concentration induced caspase-8 followed by caspase-3 activities. The increased caspases activity f...

SpringerPlus, 2013

The goal of this study was to understand the molecular event in the brain caused by hanging death... more The goal of this study was to understand the molecular event in the brain caused by hanging death (HD). Animals were subjected to either cervical dislocation (CD) or HD. Brain was collected at various times (0, 1, 3, 6 and 12 h) after death. Brain expression of p53 and Bax, cytochrome c concentration, caspases activity and DNA fragmentation were analyzed. Compared to that of CD, HD increased p53 and Bax proteins expressions, cytochrome c concentration, caspases activity and DNA fragmentation during the early period (0-6 h) of HD, whereas CD induced necrosis 3 h post-CD and thereafter. These data support that HD induces neuronal cell apoptosis, in part, through mitochondria-mediated pathways. These data also suggest that neuronal apoptosis could be a potential marker and an aid to forensic science of HD.

Clinica Chimica Acta, 2006

BackgroundIn hapten enzyme immunoassays (EIA), there is an increase or decrease of labeled hapten... more BackgroundIn hapten enzyme immunoassays (EIA), there is an increase or decrease of labeled hapten recognition by antibody that affects sensitivity of the assay. We incorporated a spacer between a hapten derivative and enzyme to test its influence on the sensitivity and specificity of enzyme immunoassays.

Free Radical Research, 2008

The present study was designed to investigate whether calcium ionophore-induced activation and ap... more The present study was designed to investigate whether calcium ionophore-induced activation and apoptosis are associated with the generation of hydrogen peroxide (H(2)O(2)) in rat eggs cultured in vitro. Culture of metaphase-II (M-II) arrested eggs in Ca(2+)/Mg(2+)-deficient medium did not induce egg activation, while a second polar body was observed in 20% of eggs when cultured in Ca(2+)/Mg(2+)-supplemented medium. In Ca(2+)/Mg(2+)-deficient medium, lower concentrations of calcium ionophore (0.2,0.4 and 0.8 microm) not only induced egg activation in a dose-dependent manner but also generation of intracellular H(2)O(2) (84.40+/-0.50 ng/egg) when compared to control eggs (80.46+/-1.34 ng/egg). The higher concentration of calcium ionophore (1.6 microm) induced apoptosis and pronounced generation of intracellular H(2)O(2) (92.43+/-0.93 ng/egg) in treated eggs. Conversely, cell-permeant antioxidant such as 2(3)-tert-butyl-4-hydroxyanisole (BHA) reduced intracellular H(2)O(2) level (81.20+/-1.42 ng/egg) and protected against calcium ionophore-induced morphological changes characteristics of egg activation and apoptosis. These results clearly suggest that calcium ionophore-induced activation and apoptosis are associated with the generation of intracellular H(2)O(2) in rat eggs.

Cell Biology International, 2009

Non-specific L-type calcium channel blockers, such as verapamil (!50 mM), induce metaphase-II (M-... more Non-specific L-type calcium channel blockers, such as verapamil (!50 mM), induce metaphase-II (M-II) arrest and apoptosis in aged rat eggs cultured in Ca 2þ -deficient medium. However, the effects of extracellular Ca 2þ on verapamil-induced M-II arrest and apoptosis have not yet been reported. We have demonstrated that postovulatory aging induced exit from M-II arrest by extruding a second polar body, a morphological sign of spontaneous egg activation (SEA). Verapamil inhibited SEA and induced egg apoptosis in a dose-dependent manner in Ca 2þ -deficient medium. The initiation of apoptotic features was observed at 50 mM of verapamil. Extracellular Ca 2þ (1.80 mM) reduced intracellular H 2 O 2 level, bax protein expression, caspase-3 activity, DNA fragmentation and protected against 50 mM, but not higher concentrations of !100 mM in verapamil-induced egg apoptosis. These results suggest that extracellular Ca 2þ ions have a role during SEA and protect against verapamilinduced apoptosis in aged rat eggs. Ó

Brain research bulletin, 2013

Present study was aimed to find out whether hanging death (HD) induces generation of reactive oxy... more Present study was aimed to find out whether hanging death (HD) induces generation of reactive oxygen species (ROS) and neuronal cell apoptosis in the dentate gyrus (DG) region of rat brain. Permanent global brain ischemia was generated by HD in experimental rats and the brain was isolated after 0, 1, 2, 3, 4, 5, 6, 9, 12 and 24h post- HD and cervical dislocation (CD). The histology, hydrogen peroxide (H2O2) concentration, catalase, caspase-9 and caspase-3 activities and DNA fragmentation were analyzed in neuronal cells of DG region of the brain. Permanent global brain ischemia generated due to HD induced generation of H2O2 as well as catalase activity. The increased level of H2O2 was associated with the increased caspase-9 and caspase-3 activities. The increased caspase-3 activity induced neuronal cell apoptosis during early period (0-9h) of HD as compare to CD group. The neuronal cells necrosis was observed only 12h post-HD, while CD induced necrosis as early as 3h post-CD and the histoarchitecture of DG region was gradually disrupted after 6h of CD. In conclusion, data of the present study suggest that the permanent global brain ischemia induces neuronal cell apoptosis during early period of HD through ROS-mediated pathway, while CD induces neuronal cell necrosis and disruption of the histoarchitecture of the DG region. Thus, neuronal cell apoptosis may be used to develop a cellular marker to find out the exact timing of HD.

Free radical …, 2009

The objective was to find out the functional roles of hydrogen peroxide (H(2)O(2)) and nitric oxi... more The objective was to find out the functional roles of hydrogen peroxide (H(2)O(2)) and nitric oxide (NO) during various stages of meiotic cell cycle and apoptosis in rat oocytes. For this purpose, 30 oocytes from each stage such as diplotene, metaphase-I (M-I), metaphase-II (M-II) and apoptosis were collected and intracellular H(2)O(2), total nitrite level and inducible nitric oxide synthase (iNOS) expression were analysed. This study demonstrated that generation of a tonic level of H(2)O(2) induces meiotic resumption in diplotene-arrested oocytes and further increase may lead to apoptosis. Conversely, reduction in iNOS expression and total nitrite level are associated with meiotic resumption in diplotene-arrested oocytes, but induce apoptosis in aged oocytes. These results suggest that generation of a tonic level of H(2)O(2), reduced iNOS expression and total nitrite level are associated with meiotic resumption, while more generation of H(2)O(2) and sustained reduced total nitrite level are linked with oocyte apoptosis in rat.

Redox report : communications in free radical research, Jan 17, 2015

The aim of this study was to determine whether an increase of intracellular nitric oxide (NO) lev... more The aim of this study was to determine whether an increase of intracellular nitric oxide (NO) level signals postovulatory aging-induced abortive spontaneous egg activation (SEA) in the rat. For this purpose, freshly ovulated eggs (arrested at metaphase-II stage; M-II) were cultured in vitro for 3 hours to induce postovulatory egg aging. The morphological changes, inducible nitric oxide synthase (iNOS) expression, NO, cytosolic free Ca(2+), 3',5' cyclic guanosine monophosphate (cGMP), cell division cycle 25B (Cdc25B) and Wee1 levels, specific phosphorylation (pThr-14/Tyr-15) as well as total cyclin-dependent kinases-1 (Cdk1) (PSTAIRE) were analyzed. The data suggest that postovulatory aging induced generation of NO, possibly through an iNOS-mediated pathway. Further, the increase in NO level was associated with augmented cytosolic free Ca(2+) as well as cGMP levels in aged eggs. In addition, a significant increase in Wee1 level and decrease of Cdc25B level were observed in ag...

Cloning and stem cells, 2007

The present study was designed to investigate whether verapamil could inhibit spontaneous parthen... more The present study was designed to investigate whether verapamil could inhibit spontaneous parthenogenetic activation in aged rat eggs cultured in vitro. Eggs collected from oviduct after 19 h post human chorionic gonadotropin (hCG) were arrested at the metaphase-II (M-II) stage and exhibited a first polar body. Culture of these aged eggs in calcium/magnesium (Ca(2+)/Mg(2+))-deficient and serum-free medium for 3 h induced exit from M-II, a morphological sign of spontaneous parthenogenetic activation in all eggs. However, verapamil reversibly inhibited spontaneous parthenogenetic activation in a dose-dependent manner. Further, lower doses (6.25, 12.5, and 25 muM) of verapamil induced egg survival, while higher doses (50 and 100 muM) were associated with the appearance of morphological apoptotic features such as shrinkage, membrane blebbing and cytoplasmic granulation prior to degeneration. The DNA fragmentation was induced [as evidenced by terminal deoxynucleotidyl transferase (TdT) n...

BioResearch open access, 2014

Hydrogen peroxide (H2O2) acts as a signaling molecule and modulates various aspects of cell funct... more Hydrogen peroxide (H2O2) acts as a signaling molecule and modulates various aspects of cell functions in a wide variety of cells including mammalian germ cells. We examined whether a decreased level of intra-oocyte cyclic 3',5'-adenosine monophosphate (cAMP) leads to accumulation of H2O2, and if so, whether a moderate increase of H2O2 inactivates maturation promoting factor (MPF) during spontaneous resumption of meiosis in rat oocytes cultured in vitro. Removal of cumulus cells and culture of denuded oocytes in vitro significantly decreased oocyte cAMP level and led to spontaneous meiotic resumption from diplotene arrest. The reduced oocyte cAMP level was associated with an increased oocyte H2O2 level and reduced catalase activity. Exogenous supplementation of H2O2 induced meiotic resumption from diplotene arrest in a concentration- and time-dependent manner in oocytes treated with 0.1 mM of 3-isobutyl-1-methylxanthine, while dibutyryl-cAMP and 3-t-butyl-4-hydroxyanisole inh...

Journal of Immunoassay & Immunochemistry, 2005

Development of polyclonal antisera is still a choice in some hard‐pressed budget laboratories. In... more Development of polyclonal antisera is still a choice in some hard‐pressed budget laboratories. In the present study, an attempt was made to isolate α‐ and β‐subunits from peak‐I hCG, generation of polyclonal antisera and their characterization. The anti‐hCG‐α antisera showed titres of 1∶8000 and anti‐hCG‐β antisera 1∶16,000 at 50% binding to radiolabelled hCG in RIA. Studies on specificity using anti

Contraception, 2002

In vitro spermicidal property of the polymer, styrene maleic anhydride (SMA), a compound under cl... more In vitro spermicidal property of the polymer, styrene maleic anhydride (SMA), a compound under clinical trial as an intravasal male contraceptive, is already established. The present study was designed to evaluate the effect of the polymer (SMA) on the viability and integrity of rat oocytes in vitro. The pH-lowering effect of this polymer was evident following precipitation in Medium 199.

Comparative Biochemistry and Physiology Part C: Pharmacology, Toxicology and Endocrinology, 1996

The effects of an adenylate cyclase activator (forskolin, FK), phosphodiesterase inhibitor (3-iso... more The effects of an adenylate cyclase activator (forskolin, FK), phosphodiesterase inhibitor (3-isobutyl-1-methyl-xanthine, IBMX) and an inhibitor of steroidogenesis (cyanoketone, CK) on germinal vesicle breakdown (GVBD) in the catfish (Clarias batrachus) were investigated in vitro. In most of the experiments GVBD was induced by using 1 μg/ml 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP), which is the maturation-inducing steroid (MIS) for this species. Adenosine 3′:5′-Cyclic monophosphate

Fertility and Sterility, 2006

To determine whether aqueous neem leaf extract (NLE) could induce degeneration of rat oocytes and... more To determine whether aqueous neem leaf extract (NLE) could induce degeneration of rat oocytes and, if so, whether apoptosis is involved during NLE-induced degeneration of oocytes cultured in vitro. Design: A controlled prospective study. Setting: Laboratory research setting at Department of Reproductive Biomedicine of the Institute. Animal(s): Fifty-four sexually immature female rats that were 24 -25 days of age. Intervention(s): The immature female rats were injected with 10 IU pregnant mare serum gonadotropin for 48 h followed by 10 IU human chorionic gonadotropin (hCG) for 16 h. After 16 h, the rats were killed and ovulated cumulus oocyte complexes were collected from the oviduct. Cumulus-enclosed as well as denuded oocytes were used in the present study. Main Outcome Measure(s): Rates of shrinkage, membrane leakage, degeneration, assessment of morphological apoptotic changes, bax protein expression, and DNA fragmentation.

Journal of Biosciences, 1995

The effects of theophylline (a phosphodiesterase inhibitor) and cAMP on 17α, 20ß-dihydroxy-4-preg... more The effects of theophylline (a phosphodiesterase inhibitor) and cAMP on 17α, 20ß-dihydroxy-4-pregnen-3-one-induced germinal vesicle breakdown was investigatedin vitro in catfish (Clarias batrachus) oocytes. Folliculated oocytes incubated with 17α, 20ß-dihydroxy-4-pregnen-3-one at the concentration of 1 μg/ml induced 93.2 ± 2.23% germinal vesicle breakdown. When the oocytes were prestimulated with 17α,20ß-dihydroxy-4-pregnen-3-one for 6 h and then treated with different concentrations of theophylline,

Journal of Immunoassay & Immunochemistry, 2006

The present study demonstrated the development of a solid phase competitive enzyme linked immunos... more The present study demonstrated the development of a solid phase competitive enzyme linked immunosorbent assay (ELISA) for direct estimation of human chorionic gonadotropin (hCG) in serum and urine. Polyclonal antisera raised against the β‐ subunit of peak‐I hCG was used in the assay. The Peak‐IA hCG‐penicillinase was used as tracer. The performance of this antiserum and tracer was compared against

Journal of Immunoassay & Immunochemistry, 2010

Homologous and heterologous combinations of enzyme conjugate with immunogen in steroid enzyme imm... more Homologous and heterologous combinations of enzyme conjugate with immunogen in steroid enzyme immunoassay (EIA) influence labeled steroid recognition by an antibody that affects the sensitivity of the assay. To develop dehydroepiandrosterone (DHEA) enzyme linked immunosorbent assay (ELISA), antibodies were generated against dehydroepiandrosterone-17-carboxymethyloxime-bovine serum albumin (DHEA-17-CMO-BSA) and dehydroepiandrosterone-7-carboxymethyloxime- bovine serum albumin (DHEA-7-CMO-BSA). Two dehydroepiandrosterone (DHEA) horse radish peroxidise (HRP) enzyme conjugates

Journal of Immunoassay & Immunochemistry, 2012

The introduction of spacers in coating steroid antigen or enzyme conjugates or immunogen is known... more The introduction of spacers in coating steroid antigen or enzyme conjugates or immunogen is known to exert an influence on the sensitivity of steroid enzyme immunoassays. We have introduced different homobifunctional spacers having varying atomic length (3 to 10) between enzyme and dehydroepiandrosterone (DHEA) moiety and studied their effects on functional parameters such as sensitivity and specificity of DHEA enzyme

SpringerPlus, 2014

Neem (Azadirachta indica L.) leaf has been widely used in ayurvedic system of medicine for fertil... more Neem (Azadirachta indica L.) leaf has been widely used in ayurvedic system of medicine for fertility regulation for a long time. The molecular mechanism by which neem leaf regulates female fertility remains poorly understood. Animal studies suggest that aqueous neem leaf extract (NLE) induces reactive oxygen species (ROS) -mediated granulosa cell apoptosis. Granulosa cell apoptosis deprives oocytes from nutrients, survival factors and cell cycle proteins required for the achievement of meiotic competency of follicular oocytes prior to ovulation. Under this situation, follicular oocyte becomes more susceptible towards apoptosis after ovulation. The increased level of hydrogen peroxide (H 2 O 2 ) inside the follicular fluid results in the transfer of H 2 O 2 from follicular fluid to the oocyte. The increased level of H 2 O 2 induces p53 activation and over expression of Bax protein that modulates mitochondrial membrane potential and trigger cytochrome c release. The increased cytosolic cytochrome c level induces caspase-9 and caspase-3 activities that trigger destruction of structural and specific proteins leading to DNA fragmentation and thereby oocyte apoptosis. Based on these animal studies, we propose that NLE induces generation of ROS and mitochondria-mediated apoptosis both in granulosa cells as well as in follicular oocyte. The induction of apoptosis deteriorates oocyte quality and thereby limits reproductive outcome in mammals.

The Journal of Experimental Zoology, 1997

ABSTRACT A decrease in cyclic AMP (cAMP) level within the catfish follicle occurs during oocyte m... more ABSTRACT A decrease in cyclic AMP (cAMP) level within the catfish follicle occurs during oocyte maturation (Haider and Chaube [1995] Comp. Biochem. Physiol., 112A:379–385). Experiments described in this report were performed to evaluate the modulations in oocyte phosphodiesterase (PDE) activity during maturation in the catfish Clarias batrachus. An increase in PDE activity was found in extracts of oocytes which were incubated for 36 hr with different concentrations of 17α,20β-dihydroxy-4-pregnen-3-one (17α,20β-DP; the naturally occurring maturation-inducing steroid of this catfish), and this increase was in a dose-dependent manner. Evaluation of the time course of response to 1 μg/ml 17α,20β-DP revealed that PDE activity increased in a time-dependent manner. A minimum detectable PDE activity was observed at 2 hr, the half-maximal activity at 6 hr, and maximum at 36 hr of incubation of oocytes with 17α,20β-DP. The two different known inhibitors (isobutylmethylxanthine and theophylline) inhibited catfish oocyte PDE activity in a dose-dependent manner. These studies suggest that the 17α,20β-DP-induced increase in PDE is involved in the decrease in cAMP in catfish oocytes during maturation. J. Exp. Zool. 277:166–170, 1997. © 1997 Wiley-Liss, Inc.