RESUMEN
Aluminum chloride is an inorganic polymeric coagulant commonly found in daily life and various materials. Although male reproductive toxicity has been associated with AlCl3 exposure, the underlying mechanism remains unclear. This study aimed to examine the impact of AlCl3 exposure on mitophagy and mitochondrial apoptosis in testicular tissue and mouse spermatocytes. Reactive oxygen species (ROS) and ATP levels were measured in GC-2spd after AlCl3 exposure using a multifunctional enzyme labeler. The changes in mitochondrial membrane potential (MMP) and TUNEL were observed through confocal laser microscopy, and the expression of proteins associated with mitophagy and apoptosis was analyzed using Western blot. Our results demonstrated that AlCl3 exposure disrupted mitophagy and increased apoptosis-related protein expression in testicular tissues. In the in vitro experiments, AlCl3 exposure induced ROS production, suppressed cell viability and ATP production, and caused a decrease in MMP, leading to mitophagy and cell apoptosis in GC-2spd cells. Intervention with N-acetylcysteine (NAC) reduced ROS production and partially restored mitochondrial function, thereby reversing the resulting mitophagy and cell apoptosis. Our findings provide evidence that ROS-mediated mitophagy and cell apoptosis play a crucial role in the toxicity of AlCl3 exposure in GC-2spd. These results contribute to the understanding of male reproductive toxicity caused by AlCl3 exposure and offer a foundation for future research in this area.
RESUMEN
OBJECTIVE: To study the impacts of aluminum chloride (AlCl3) on the sperm quality, sperm mitochondrial membrane potential (MMP) and sperm mitochondrial membrane permeability transition pore (MPTP) function of male rats, and the possible mechanisms of AlCl3 inducing the declination of sperm quality. METHODS: According to the median lethal dose (LD50) of AlCl3ã»6H2O in drinking water, we randomly assigned 96 male Wistar rats weighing 180ï¼200 g to four groups of equal number and fed them with AlCl3 aqueous drinking water at 256.72 mg/kg/d (1/5 LD50, high-dose group), 128.36 mg/kg/d (1/10 LD50, medium-dose group), 64.18 mg/kg/d (1/20 LD50, low-dose group) and 0 mg/kg/d (control group), respectively, all for 16 weeks. Then, we examined the quality of the epididymal sperm of the rats, observed the morphology of the sperm mitochondria under the transmission electron microscope, and determined the MMP level of the sperm mitochondria and the function of the MPTP by flow cytometry. RESULTS: The percentage of progressively motile sperm was significantly decreased in the low-, medium- and high-dose AlCl3 groups as compared with that in the control group (ï¼»46.49 ± 5.37ï¼½%, ï¼»33.50 ± 8.75ï¼½% and ï¼»16.94 ± 5.00ï¼½% vs ï¼»66.28 ± 5.68ï¼½%, P < 0.01), that of dead sperm was remarkably increased (ï¼»19.73 ± 5.57ï¼½%, ï¼»35.80 ± 5.90ï¼½% and ï¼»55.19 ± 4.97ï¼½% vs ï¼»12.71 ± 4.84ï¼½%, P < 0.01), and so was that of morphologically abnormal sperm (ï¼»19.06 ± 2.44ï¼½%, ï¼»23.78 ± 3.29ï¼½% and ï¼»32.06 ± 4.65ï¼½% vs ï¼»14.56 ± 1.62ï¼½%, P < 0.01). Sperm mitochondrial swelling was aggravated in the AlCl3-exposed rats in a dose-dependent manner. The sperm MMP level was significantly lower in the low-, medium- and high-dose AlCl3 groups than in the control (ï¼»60.88 ± 7.37ï¼½%, ï¼»51.54 ± 6.12ï¼½% and ï¼»37.70 ± 7.44ï¼½% vs ï¼»74.35±4.67ï¼½%, P < 0.01), with a negative correlation to the dose of AlCl3 (rs = ï¼0.819, P < 0.01), while the pathologically open MPTP was markedly higher in the former three than in the latter group (ï¼»27.80 ± 5.74ï¼½%, ï¼»36.58 ± 6.67ï¼½% and ï¼»64.95 ± 8.07ï¼½% vs ï¼»15.37 ± 7.13ï¼½%, P < 0.01), with a positive correlation to the dose of AlCl3 (rs = 0.867, P < 0.01). CONCLUSIONS: Exposure to aluminum can cause sperm mitochondrial swelling, decrease the sperm MMP level, induce pathological opening of the MPTP, and consequently reduce sperm quality in male rats.
