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Guler Okyay A.,Mustafa Kemal University | Aslan M.,Yuzuncu Yil University | Taskin A.,Harran University | Selek S.,Harran University | And 2 more authors.
Turkiye Klinikleri Journal of Medical Sciences | Year: 2014

Objective: Oxidative stress has been well recognized as a component in the pathogenesis of many diseases, including female infertility. In this study, we aimed to investigate serum paraoxonase (PON1), arylesterase and myeloperoxidase (MPO) activities, and lipid hydroperoxide (LOOH) levels as oxidative stress markers along with their relationship with the pregnancy rate in women undergoing in vitro fertilization (IVF) treatment. Material and Methods: Serum samples of 179 subjects were collected immediately before starting ovarian stimulation and on ovum pick-up (OPU) day during IVF treatment. Stimulation protocol and starting doses were determined individually. When the leading follicle reached at least 17 mm in size, recombinant human chorionic gonadotropin (Ovitrelle, 250 mcg, Serono) was administered for ovulation induction. Serum basal/salt-stimulated paraoxonase, arylesterase activities, myeloperoxidase activity, and lipid hydroperoxide levels were compared between two samples. Subjects were also divided into two groups according to the presence of pregnancy, and the groups were compared in terms of oxidative stress markers studied. Results: Serum MPO activity and LOOH levels were significantly higher on ovum pick up day (p<0.05, p<0.001, respectively), while basal/salt-stimulated paraoxonase and arylesterase activities were significantly lower (p=0.012, p=0.041, respectively) than those before ovarian stimulation. Serum LOOH levels on OPU day were significantly higher in non-pregnant group than pregnant one (p<0.001). Although basal/salt-stimulated paraoxonase, arylesterase and myeloperoxidase activities were higher in the non-pregnant group compared to the pregnant group, it was not statistically significant (p>0.05). Conclusion: Ovarian stimulation during IVF treatment resulted in increased oxidative stress and decreased PON1 activity. However, changes in the studied parameters were not found to be significantly associated with the pregnancy results. Further studies are required to clarify our results. © 2014 by Türkiye Klinikleri. Source

Kim J.-H.,Kyungpook National University | Park S.-J.,Kyungpook National University | Kim T.-S.,Embryology Laboratory | Kim J.-M.,Chungnam National University | Lee D.-S.,Kyungpook National University
Life Sciences | Year: 2016

Aims Leydig cells are characterized by their ability to produce testosterone. When the Leydig cells are unable to produce enough testosterone, spermatogenesis fails completely. Considering this, it is of great interest to investigate whether the expressions of steroidogenic enzymes are affected by testicular heat stress. This study aimed to demonstrate that heat induced ER-stress significantly influences steroidogenic enzyme expression and testosterone production in the Leydig cells. Main methods C57BL/6 mice were subjected to repetitive testicular heat-treatment at 42 °C for 15 min per day, and heat-treated mLTC-1 cells following hCG treatment for 1 h. The protein and RNA expressions were measured by Western blot, RT-PCR. The testosterone and progesterone levels were detected by EIA. The histological and pathological characteristics using hematoxylin and eosin (H&E) and antibody stains. Key findings The 3β-HSD expression was decreased by heat-stress and hCG treatment. While the GRP78/BiP and CHOP levels were increased by ER-stress inducers, those of the steroidogenic enzyme and progesterone were decreased. In contrast, an ER-stress inhibitor rescued the testosterone levels, even under heat-stress conditions. Moreover, the Leydig cells were randomly scattered, and severely damaged upon repetitive testicular heat-treatment. Additionally, immunohistochemical analyses revealed that cleaved caspase-3 was elevated in the testicular Leydig cells, and rescued by TUDCA. Thus, repetitive testicular heat-treatment in mice promotes excessive ER-stress, thereby leading to apoptosis of the Leydig cells and thus, decreased testosterone production. Significance Our findings help to provide an ER-stress mediate mechanistic explanation to the impairment of spermatogenesis upon elevation of the testicular temperature. © 2015 Elsevier Inc. All rights reserved. Source

Park S.-J.,Kyungpook National University | Kim T.-S.,Embryology Laboratory | Kim J.-M.,Chungnam National University | Chang K.-T.,Korea Research Institute of Bioscience and Biotechnology | And 2 more authors.
Molecules and Cells | Year: 2015

Superovulation induced by exogenous gonadotropin treatment (PMSG/hCG) increases the number of available oocytes in humans and animals. However, Superovulatory PMSG/hCG treatment is known to affect maternal environment, and these effects may result from PMSG/hCG treatment- induced oxidative stress. 2-Cys peroxiredoxins (2-Cys Prxs) act as antioxidant enzymes that protect cells from oxidative stress induced by various exogenous stimuli. Therefore, the objective of this study was to test the hypothesis that repeated PMSG/hCG treatment induces 2-Cys Prx expression and overoxidation in the reproductive tracts of female mice. Immunohistochemistry and western blotting analyses further demonstrated that, after PMSG/hCG treatment, the protein expression levels of 2-Cys Prxs increased most significantly in the ovaries, while that of Prx1 was most affected by PMSG/hCG stimulation in all tissues of the female reproductive tract. Repeated PMSG/hCG treatment eventually leads to 2-Cys Prxs overoxidation in all reproductive organs of female mice, and the abundance of the 2-Cys Prxs-SO2/3 proteins reported here supports the hypothesis that repeated superovulation induces strong oxidative stress and damage to the female reproductive tract. Our data suggest that excessive oxidative stress caused by repeated PMSG/hCG stimulation increases 2-Cys Prxs expression and overoxidation in the female reproductive organs. Intracellular 2-Cys Prx therefore plays an important role in maintaining the reproductive organ environment of female mice upon exogenous gonadotropin treatment. © The Korean Society for Molecular and Cellular Biology. All rights reserved. Source

Nation T.,Douglas Stephens Surgical Research Laboratory | Nation T.,University of Melbourne | Buraundi S.,Douglas Stephens Surgical Research Laboratory | Balic A.,Douglas Stephens Surgical Research Laboratory | And 6 more authors.
Journal of Pediatric Surgery | Year: 2011

Aim: During testicular descent (TD), the genitofemoral nerve (GFN) is masculinized by androgen. This study aimed to test whether androgen receptor (AR), estrogen receptorα (ERA), or estrogen receptor β (ERB) are expressed during TD in the GFN spinal segments and dorsal root ganglia (DRG) in normal and flutamide-treated rats. Methods: Time-mated Sprague-Dawley dams were injected with flutamide (75 mg/kg, subcutaneously (S/C) in sunflower oil) on embryonic (E) days 16 to 19. Embryonic and postnatal (P) male L1-2 spinal cord segments were collected (E16, E17, E19, P0, P2, and P4) in control and flutamide-treated groups (n = 5-10). Samples were fixed in 4% paraformaldehyde. Five-micrometer-thick sections were prepared immunohistochemically for AR, ERA, and ERB. Results: During TD, ERB was expressed in L1-2 DRG. Surprisingly, AR was not expressed in prenatal DRG, only after P2. There was no ERA expression. Flutamide had no effect on AR, ERB, or ERA expression in the L1-2 DRG during TD. Conclusion: During the E window of androgen sensitivity, the GFN is not directly masculinized, with little AR expression and no change with flutamide over this period. Estrogen receptor β is expressed in the DRG during TD. However, its relevance is yet to be determined. © 2011 Elsevier Inc. Source

Min H.,Embryology Laboratory | Lee J.-Y.,Embryology Laboratory | Bok J.,Embryology Laboratory | Chung H.J.,Embryology Laboratory | Kim M.H.,Embryology Laboratory
Biochemical and Biophysical Research Communications | Year: 2010

Hoxc8 is a member of Hox family transcription factors that play crucial roles in spatiotemporal body patterning during embryogenesis. Hox proteins contain a conserved 61 amino acid homeodomain, which is responsible for recognition and binding of the proteins onto Hox-specific DNA binding motifs and regulates expression of their target genes. Previously, using proteome analysis, we identified Proliferating cell nuclear antigen (Pcna) as one of the putative target genes of Hoxc8. Here, we asked whether Hoxc8 regulates Pcna expression by directly binding to the regulatory sequence of Pcna. In mouse embryos at embryonic day 11.5, the expression pattern of Pcna was similar to that of Hoxc8 along the anteroposterior body axis. Moreover, Pcna transcript levels as well as cell proliferation rate were increased by overexpression of Hoxc8 in C3H10T1/2 mouse embryonic fibroblast cells. Characterization of 2.3 kb genomic sequence upstream of Pcna coding region revealed that the upstream sequence contains several Hox core binding sequences and one Hox-Pbx binding sequence. Direct binding of Hoxc8 proteins to the Pcna regulatory sequence was verified by chromatin immunoprecipitation assay. Taken together, our data suggest that Pcna is a direct downstream target of Hoxc8. © 2010 Elsevier Inc. All rights reserved. Source

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