Browsing by Author "Orellana, Renan"

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    A decrease of docosahexaenoic acid in testes of mice fed a high-fat diet is associated with impaired sperm acrosome reaction and fertility
    (2021) Bunay, Julio; Gallardo, Luz-Maria; Luis Torres-Fuentes, Jorge; Veronica Aguirre-Arias, M.; Orellana, Renan; Sepulveda, Nestor; Moreno, Ricardo D.
    Obesity is a major worldwide health problem that is related to most chronic diseases, including male infertility. Owing to its wide impact on health, mechanisms underlying obesity-related infertility remain unknown. In this study, we report that mice fed a high-fat diet (HFD) for over 2 months showed reduced fertility rates and increased germ cell apoptosis, seminiferous tubule degeneration, and decreased intratesticular estradiol (E2) and E2-to-testosterone ratio. Interestingly, we also detected a decrease in testicular fatty acid levels, behenic acid (C22:0), and docosahexaenoic acid (DHA, 22:6n-3), which may be related to the production of dysfunctional spermatozoa. Overall, we did not detect any changes in the frequency of seminiferous tubule stages, sperm count, or rate of in vitro capacitation. However, there was an increase in spontaneous and progesterone-induced acrosomal exocytosis (acrosome reaction) in spermatozoa from HFD-fed mice. These data suggest that a decrease in E2 and fatty acid levels influences spermatogenesis and some steps of acrosome biogenesis that will have consequences for fertilization. Thus, our results add new evidence about the adverse effect of obesity in male reproduction and suggest that the acrosomal reaction can also be affected under this condition.
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    Antigen retrieval by citrate solution improves western blot signal
    (2019) Patino-Garcia, Daniel; Rocha-Perez, Nadia; Moreno, Ricardo D.; Orellana, Renan
    In the present work, we describe and evaluate an additional step to the standard western blot protocol to increase signal strength after revealing. Weak or absence of signal is a common issue in western blot protocol leading to unexpected results. In our Antigen Retrieval for Western Blot Method (ARWB method), after transfer, the membrane was incubated in a citrate buffer following normal antigen retrieval procedure used for immunohistochemistry. Later, standard protocol was performed in order to reveal and compare with unexposed membranes to this antigen retrieval step. Signal in bands obtained by the modified protocol resulted significantly higher (in all 13 antibodies analyzed) compared to standard protocol. Some bands were only visible after citrate incubation. This method is a simple and economical way to improve results in western blot analysis.
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    Daily exposure to phthalates and alkylphenols alters miR biogenesis and expression in mice ovaries
    (2020) Patino-Garcia, Daniel; Cruz-Fernandes, Leonor; Bunay, Julio; Orellana, Renan; Moreno, Ricardo D.
    Reproductive hormone imbalance in infertile women is correlated to high levels of phthalates and alkylphenols, which are among endocrine-disrupting chemicals (EDCs). Previous studies have shown that they interfere with gene expression by deregulating levels of microRNAs (miRs), small non-coding RNAs targeting mRNAs encoding enzymes in the hormone biosynthesis pathway. However, this effect depends on the target organ, dose and whether or not they are alone or in mixtures. Our goal was to study whether the biosynthesis, and a specific group of miRs targeting mRNAs encoding enzymes in steroid hormone biosynthesis, are deregulated in the ovaries of female mice chronically exposed to a mixture of three phthalates (DEHP+DBP+BBP) and two alkylphenols (NP+OP) at a human environmentally relevant dose. We performed qPCR and Western blot assays along with a bioinformatics approach and found that this mixture modified the biogenesis machinery of miRs, inducing an increase in the mRNA levels of Drosha and Dicerl and DROSHA protein levels. In addition, we found changes in the precursor and mature forms of miR-96-5p, miR-200b-3p, miR-365-3p, miR-378a-3p and miR-503-5p which target steroidogenic pathway enzymes. Finally, using primary granulosa cell culture, we confirmed that miR-200b-3p targets Cyp19a1, transcript encoding CYP19A1, the enzyme that produces estradiol (E-2). These results indicate that chronic exposure to phthalates and alkylphenols mixture alters the biogenesis of ovary miRs and increases the expression of miRs implicated in the control of steroidal hormone synthesis in female mice, thus contributing to reproductive pathologies.
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    Embryo Buoyancy and Cell Death Gene Expression During Embryogenesis of Yellow-Tail Kingfish Seriola lalandi
    (2021) Palomino, Jaime; Gomez, Camila; Otarola, Maria Teresa; Dettleff, Phillip; Patino-Garcia, Daniel; Orellana, Renan; Moreno, Ricardo D.
    In pelagic fish, embryo buoyancy is a noteworthy aspect of the reproductive strategy, and is associated with overall quality, survival, and further developmental success. In captivity, the loss of buoyancy of early embryos correlates with high mortality that might be related to massive cell death. Therefore, the aim of this study was to evaluate under captivity conditions the expression of genes related to the apoptosis process during the early embryonic development of the pelagic fish Seriola lalandi, and its relationship to the buoyancy of embryos. The relative expression of bcl2, bax-like, casp9, casp8, and casp3 was evaluated by RT-qPCR and FasL/Fas protein levels by western blot in five development stages of embryos sorted as floating or low-floating. All genes examined were expressed in both floating and low-floating embryos up to 24 h of development. Expression of the pro-apoptotic factors bax, casp9, casp8, and casp3 was higher in low-floating as compared with floating embryos in a developmental stage-specific manner. In contrast, there was no difference in expression of bcl2 between floating and low-floating embryos. Fas protein was detected as a single band in floating embryos without changes in expression throughout development; however, in low-floating embryos, three higher intensity reactive bands were detected in the 24-h embryos. Interestingly, FasL was only detected at 24-h in floating embryos, whereas in low-floating samples this ligand was present at all stages, with a sharp increase as development progressed. Cell death, as evaluated by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, was highly increased in low-floating embryos as compared to floating embryos throughout all developmental stages, with the highest levels observed during the gastrula stage and at 24 h. The results of this study suggest that an increase in cell death, probably associated with the intrinsic and extrinsic apoptosis pathways, is present in low-floating embryos that might explain their lower developmental potential under captivity conditions.
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    Estetrol Increases Progesterone Genetic Response without Triggering Common Estrogenic Effects in Endometriotic Cell Lines and Primary Cultures
    (2023) Patino-Garcia, Daniel; Palomino, Jaime; Pomes, Cristian; Celle, Claudia; Torres-Estay, Veronica; Orellana, Renan
    Estetrol (E4), a natural estrogen produced by the human fetal liver, is actively studied for menopause and breast cancer treatment. It has low side effects and preferential estrogen receptor alpha (ER alpha) affinity. There are no data about its effects on endometriosis, a common gynecological disease affecting 6-10% of cycling women, generating painful pelvic lesions and infertility. Current combined hormone treatment (progestins and estrogens) is safe and efficient; nevertheless, one-third of patients develop progesterone (P4) resistance and recurrence by reducing P4 receptors (PRs) levels. We aimed to compare E4 and 17 beta-estradiol (E2) effects using two human endometriotic cell lines (epithelial 11Z and stromal Hs832 cells) and primary cultures from endometriotic patients. We evaluated cell growth (MTS), migration (wound assay), hormone receptors levels (Western blot), and P4 response by PCR array. Compared to E2, E4 did not affect cell growth or migration but increased estrogen receptor alpha (ER alpha) and PRs, and reduced ER beta. Finally, the incubation with E4 improved the P4 gene response. In conclusion, E4 increased PRs levels and genetic response without inducing cell growth or migration. These results suggest that E4 might be useful for endometriosis treatment avoiding P4 resistance; however, evaluating its response in more complex models is required.