Testicular Toxicity in Rats Exposed to AlCl3: a Proteomics Study.

Aluminum contamination is a growing environmental and public health concern, and aluminum testicular toxicity has been reported in male rats; however, the underlying mechanisms of this toxicity are unclear. The objective of this study was to investigate the effects of exposure to aluminum chloride (AlCl3) on alterations in the levels of sex hormones (testosterone [T], luteinizing hormone [LH], and follicle-stimulating hormone [FSH]) and testicular damage. Additionally, the mechanisms of toxicity in the testes of AlCl3-exposed rats were analyzed by proteomics. Three different concentrations of AlCl3 were administered to rats. The results demonstrated a decrease in T, LH, and FSH levels with increasing concentrations of AlCl3 exposure. HE staining results revealed that the spermatogenic cells in the AlCl3-exposed rats were widened, disorganized, or absent, with increased severe tissue destruction at higher concentrations of AlCl3 exposure. Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses revealed that differentially expressed proteins (DEPs) after AlCl3 exposure were primarily associated with various metabolic processes, sperm fibrous sheath, calcium-dependent protein binding, oxidative phosphorylation, and ribosomes. Subsequently, DEPs from each group were subjected to protein-protein interaction (PPI) analysis followed by the screening of interactional key DEPs. Western blot experiments validated the proteomics data, revealing the downregulation of sperm-related DEPs (AKAP4, ODF1, and OAZ3) and upregulation of regulatory ribosome-associated protein (UBA52) and mitochondrial ribosomal protein (MRPL32). These findings provide a basis for studying the mechanism of testicular toxicity due to AlCl3 exposure.

Reactive Oxygen Species-Mediated Mitophagy and Cell Apoptosis are Involved in the Toxicity of Aluminum Chloride Exposure in GC-2spd.

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.

Associations of serum estradiol level, serum estrogen receptor-alpha level, and estrogen receptor-alpha polymorphism with male infertility: A retrospective study.

ABSTRACT: Estradiol regulates spermatogenesis partly via estrogen receptor-alpha (ESRα). This study aimed to analyze the associations of serum estradiol level, serum ESRα level, and ESRα gene polymorphisms with sperm quality.This retrospective study included infertile men attending the Reproductive Center, Affiliated Hospital of Youjiang Medical University for Nationalities, and a control group without a history of fertility (October, 2016 to March, 2017). Data regarding sperm quality, serum levels of estradiol and ESRα, and rs2234693C/T genotype were extracted from the medical records. Pearson/Spearman correlations (as appropriate) between estradiol level, ESRα level, and sperm quality parameters were evaluated.The analysis included 215 men with infertility and 83 healthy controls. The infertile group had higher serum levels of estradiol (147.57 ±â€Š35.3 vs 129.62 ±â€Š49.11 pg/mL, P < .05) and ESRα (3.02 ±â€Š2.62 vs 1.33 ±â€Š0.56 pg/mL, P < .05) than the control group. For the infertile group, serum estradiol level was negatively correlated with sperm concentration, percentage of progressively motile sperm, and percentage of sperm with normal morphology (r = 0.309, 0.211, and 0.246, respectively; all P < .05). Serum estradiol and ESRα levels were lower in infertile men with normozoospermia than in those with azoospermia, oligozoospermia, mild azoospermia, or malformed spermatozoa (all P < .05). Sperm concentration, percentage of progressively motile sperm, serum ESRα level, and serum estradiol level did not differ significantly among the rs2234693 CC, CT, and TT genotypes.Elevated serum levels of estradiol and possibly ESRα might have a negative impact on sperm quality and fertility, whereas single nucleotide polymorphisms at rs2234693 of the ESRα gene had little or no effect.

[Impacts of aluminum on sperm quality and sperm mitochondria in male rats].

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 AlCl3・6H2O in drinking water, we randomly assigned 96 male Wistar rats weighing 180－200 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 = －0.819, 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.

Effects of copper source and concentration on in vitro phytate phosphorus hydrolysis by phytase.

Five copper (Cu) sources were studied at pH 2.5, 5.5, and 6.5 to determine how Cu affects phytate phosphorus (PP) hydrolysis by phytase at concentrations up to 500 mg/kg diet (60 min, 40-41 degrees C). Subsequently, Cu solubility with and without sodium phytate was measured. Adding Cu inhibited PP hydrolysis at pH 5.5 and pH 6.5 (P < 0.05). This inhibition was greater with higher concentrations of Cu. Tri-basic copper chloride and copper lysinate inhibited PP hydrolysis much less than copper sulfate pentahydrate, copper chloride, and copper citrate (P < 0.05). A strong negative relationship was observed between PP hydrolysis and soluble Cu at pH 5.5 (r = -0.76, P < 0.0001) and 6.5 (r = -0.54, P < 0.0001). In conclusion, pH, Cu concentration, and source influenced PP hydrolysis by phytase in vitro and were related to the amount of soluble Cu and the formation of insoluble copper-phytin complexes.