RESUMO
With the progressive increase in the use of reproductive biotechnologies in the cattle industry, like artificial insemination and in vitro embryo production, the accurate determination of fertilizing competence of cryopreserved sperm samples is an essential issue. The routine methodology to assess bull sperm quality relies primarily on count, viability and motility of spermatozoa. However, these parameters do not tightly predict the reproductive success of samples. Therefore, identification of complementary markers of sperm functionality to strengthen the predictability of traditional spermogram is desirable to improve livestock reproduction practices. Previous results from our laboratory indicated that α5ß1 integrin plays a key role in bovine sperm function and mediates their interaction with the female reproductive tract. Thus, this study aimed to investigate whether the localization of α5ß1 held a correlation with fertilizing ability of bovine cryopreserved semen samples. Firstly, we assessed the quality of samples from six different bulls (A-F). We determined motility and viability of sperm samples after thawing and selection. Additionally, we measured the capacitation state of the samples by chlortetracycline (CTC) assay in the presence or absence of heparin, as an indicator of their responsiveness to a capacitating stimulus. Based on these assays, samples were classified being A the bull with the lowest quality and F the bull with the highest quality. Then, we studied the presence and localization of α5ß1 integrin. This protein showed a distribution pattern in the acrosomal (A), post-acrosomal (P) and acrosomal + post-acrosomal (A + P) regions with different localization percentages among the studied samples. Next, we determined the fertilizing ability of the samples in in vitro fertilization (IVF) assays and performed correlation analyses between IVF outcome and the routine spermogram parameters or α5ß1 integrin localization patterns. When the percentage of cells showing α5ß1 integrin was compared to fertilization rate, no correlation was observed. However, the presence of α5ß1 integrin in P and A + P regions (PA pattern), positively correlated with IVF rate (p < 0.05). These results suggest that while routine semen analyses failed to predict sperm reproductive competence, integrin localization in post-acrosomal region (PA pattern) showed a positive correlation with IVF outcome, thus posing an attractive marker to predict more accurately the reproductive performance of an individual.
Assuntos
Integrinas , Motilidade dos Espermatozoides , Animais , Bovinos , Criopreservação/veterinária , Feminino , Fertilidade , Masculino , EspermatozoidesRESUMO
La osteoartritis (OA) es una enfermedad crónica, degenerativa, muy invalidante, que destruye en forma gradual y progresiva el cartílago articular en diversas regiones: rodillas, caderas, hombros, manos, tobillos y columna vertebral. En este sentido, el ejercicio ha sido descrito como la intervención no farmacológica más recomendada para pacientes con OA. La práctica regular de ejercicio es considerada un componente integral del estilo de vida saludable; sin embargo, su efecto en el cartílago se mantiene como objeto de debate y especulaciones, así como la relación del ejercicio con el desarrollo de OA. Algunos estudios de modelos animales sugieren que el ejercicio puede ser beneficioso para la salud del cartílago, mientras otros demuestran su efecto nocivo. Una explicación general a estos resultados inconsistentes es que el correr a intensidad moderada tiene efectos beneficiosos, mientras que correr "vigorosamente" o de manera "extenuante" lleva a un efecto nocivo. El objetivo de este trabajo consistió en realizar una revisión de la literatura acerca de los efectos del ejercicio sobre el cartílago artícular, especialmente enfocado a modelos animales experimentales con ratas.
Osteoarthritis (OA) is a chronic, degenerative, and very disabling disease that gradually and progressively destroys articular cartilage in various regions: knees, hips, shoulders, hands, ankles and spine. In this sense, exercise has been described as the most recommended non-pharmacological intervention for patients with OA. Regular exercise is considered an integral component of the healthy lifestyle. However, its effect on cartilage remains the subject of debate and speculation, as well as the relationship between exercise and the development of OA. Some animal model studies suggest that exercise may be beneficial for cartilage health, while others demonstrate its harmful effect. A general explanation for these inconsistent results is that running at moderate intensity has beneficial effects, while running "vigorously" or "strenuously" leads to a harmful effect. The aim of this work was to make a literature review about the effects of exercise on cartilage, especially focused on experimental animal models with rats.