RESUMO
Inhibiting oxidative stress is key for ensuring sperm motility during semen cryopreservation. The aim of this study was to investigate the effect of adding alpha-lipoic acid (ALA) as an extender in rooster semen cryopreservation. Different concentrations of ALA were added to the frozen diluent of rooster semen; subsequently, computer-aided semen analysis was used to determine membrane functional integrity, acrosome integrity, antioxidant capacity (based on T-AOC, GSH-Px, SOD, CAT, and MDA contents), and mitochondrial integrity. The frozen sperm ultrastructure was observed using transmission electron microscopy. The results showed that the addition of different concentrations of ALA partially to greatly improved the quality of frozen sperm; in particular, 8 µg/mL ALA significantly improved multiple parameters of sperm quality, including sperm motility and antioxidant enzyme activity, after freeze-thaw. The results of this study provide empirical and theoretical support for effective rooster semen cryopreservation and can inform the development of new protective agents in the field of livestock reproduction.
Assuntos
Antioxidantes , Galinhas , Criopreservação , Estresse Oxidativo , Preservação do Sêmen , Ácido Tióctico , Animais , Criopreservação/veterinária , Preservação do Sêmen/veterinária , Preservação do Sêmen/métodos , Masculino , Ácido Tióctico/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Galinhas/fisiologia , Antioxidantes/farmacologia , Análise do Sêmen/veterinária , Crioprotetores/farmacologia , Sêmen/efeitos dos fármacos , Sêmen/fisiologia , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Motilidade dos Espermatozoides/efeitos dos fármacosRESUMO
Aeromonas veronii is a pathogen which can induce diseases in humans, animals and aquatic organisms, but its pathogenic mechanism and virulence factors are still elusive. In this study, we successfully constructed a mutant strain (ΔascP) by homologous recombination. The results showed that the deletion of the ascP gene significantly down-regulated the expression of associated effector proteins in A. veronii compared to its wild type. The adhesive and invasive abilities of ΔascP to EPC cells were 0.82-fold lower in contrast to the wild strain. The toxicity of ΔascP to cells was decreased by about 2.91-fold (1 h) and 1.74-fold (2 h). Furthermore, the LD50 of the mutant strain of crucian carp was reduced by 19.94-fold, and the virulence was considerably attenuated. In contrast to the wild strain, the ΔascP content in the liver and spleen was considerably lower. The titers of serum cytokines (IL-8, TNF-α, and IL-1ß) in crucian carp after the infection of the ΔascP strain were considerably lower in contrast to the wild strain. Hence, the ascP gene is essential for the etiopathogenesis of A. veronii TH0426.
Assuntos
Carpas , Doenças dos Peixes , Infecções por Bactérias Gram-Negativas , Humanos , Animais , Aeromonas veronii/genética , Aeromonas veronii/metabolismo , Virulência/genética , Fatores de Virulência/genética , Fatores de Virulência/metabolismo , Infecções por Bactérias Gram-Negativas/veterináriaRESUMO
Aeromonas veronii is one of the main pathogens causing freshwater fish sepsis and ulcer syndrome. This bacterium has caused serious economic losses in the aquaculture industry worldwide, and it has become an important zoonotic and aquatic agent. However, little is known about the molecular mechanism of pathogenesis of A. veronii. In this study, we first constructed an unmarked mutant strain (ΔpreA) by generating an in-frame deletion of the preA gene, which encodes a periplasmic binding protein, to investigate its role in A. veronii TH0426. Our results showed that the motility and biofilm formation ability of ΔpreA were similar to those of the wild-type strain. However, the adhesion and invasion ability in epithelioma papulosum cyprini (EPC) cells were significantly enhanced (2.0-fold). Furthermore, the median lethal dose (LD50) of ΔpreA was 7.6-fold higher than that of the wild-type strain, which illustrates that the virulence of the mutant was significantly enhanced. This finding is also supported by the cytotoxicity test results, which showed that the toxicity of ΔpreA to EPC cells was enhanced 1.3-fold relative to the wild type. Conversely, tolerance test results showed that oxidative stress resistance of ΔpreA decreased 5.9-fold compared to with the wild-type strain. The results suggest that preA may negatively regulate the virulence of A. veronii TH0426 through the regulation of resistance to oxidative stress. These insights will help to further elucidate the function of preA and understand the pathogenesis of A. veronii.
