Aluminum exposure promotes histopathological and pro-oxidant damage to the prostate and gonads of male and female adult gerbils

Airborne Aluminum as an Underestimated Source of Human Exposure: Quantification of Aluminum in 24 Human Tissue Types Reveals High Aluminum Concentrations in Lung and Hilar Lymph Node Tissues

Aluminum (Al) is the most abundant metal in the earth's crust, and humans are exposed to Al through sources like food, cosmetics, and medication. So far, no comprehensive data on the Al distribution between and within human tissues were reported. We measured Al concentrations in 24 different tissue types of 8 autopsied patients using ICP-MS/MS (inductively coupled plasma-tandem mass spectrometry) under cleanroom conditions and found surprisingly high concentrations in both the upper and inferior lobes of the lung and hilar lymph nodes. Al/Si ratios in lung and hilar lymph node samples of 12 additional patients were similar to the ratios reported in urban fine dust. Histological analyses using lumogallion staining showed Al in lung erythrocytes and macrophages, indicating the uptake of airborne Al in the bloodstream. Furthermore, Al was continuously found in PM2.5 and PM10 fine dust particles over 7 years in Upper Austria, Austria. According to our findings, air pollution needs to be reconsidered as a major Al source for humans and the environment.

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.

Histological alterations and oxidative stress in adult zebrafish muscle after aluminium exposure

Aluminium (Al) is among the most abundant metals in nature, and its presence in the environment is further increasing by anthropogenic activities. In water bodies, the Al concentrations ranged between 0.001 and 50 mg/L, raising concerns about the health of aquatic organisms. For this reason, zebrafish was chosen as the model, since it is well suited for ecotoxicological studies. Adult specimens were exposed to 11 mg/L of Al for 10, 15 and 20 days to assess both the morphology and the oxidative state of muscle tissue. Considering the involvement of ROS, the activity of the main antioxidant enzymes, metallothioneins contents, but also oxidative damage and enzymes involved in energy consumption and neuromuscular transmission were assessed. Collected data showed an increase in the thickness of the endomysium and resorbed myofibrils in the organisms exposed to Al for 10 days, and an increase of myotomes' size in the organisms exposed to Al for 15 days. Moreover, the organisms exposed for less time to Al, it was evident an activation of anaerobic metabolism and the increased activity of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase and glutathione S-transferases. However, these effects stabilized with increasing exposure time. In addition, only after 20 days of treatment did the oxidative damage to the proteins and the activity of acetylcholinesterase increase while the levels of metallothioneins and the lipid peroxidation were lower for all treated animals when compared to the control group. Overall, the biochemical and histological changes induced by aluminium exposure in the muscular tissue represent a relevant contribution to understanding the environmental risk due to the diffusion of this metal within the aquatic compartment.

Subacute exposure to aluminum chloride causes prolonged morphological insults in the ventral male prostate and in the female prostate of adult gerbils

Aluminum (Al) is a widespread metal in the environment, and is found in fresh or processed foods, household utensils, packaging, and medicines. In addition to its high toxicity, Al can also have estrogenic agonistic effects on target organs. Considering that the Al effects on the prostate are little known, the aim of this study was to evaluate the impact of aluminum chloride (AlCl₃ ) subacute exposure on the morphophysiology of the male ventral prostate and the female prostate of adult gerbils. Furthermore, the glandular restoration capacity in face of the Al insults was evaluated in gerbils that were submitted to 30 days of recovery. Male and female gerbils were orally exposed to AlCl₃ (10 mg/kg) for 30 consecutive days. The animals were euthanized 1 day (Al1D) or 30 days (Al30D) after the end of treatment. Prostates were dissected out and processed for structural, ultrastructural and immunohistochemical analyses. Male ventral prostates and female prostates of the Al1D group showed increased cell proliferation, glandular hyperplasia, increased secretory activity and greater androgen receptor immunoreactivity. In males, Al withdrawal (Al30D) allowed a partial recovery of the prostate, as the glandular secretory activity, and frequency of androgen receptor positive cells were similar to the control group. In females, the recuperation interval (Al30D) was not enough to restore the prostatic morphology, since the gland remained hyperplastic, proliferative, and with greater androgen and estrogen receptor immunoreactivity. These data alert to the importance of avoiding Al exposure, since this metal can have a harmful and prolonged action on the prostate.

Elemental composition of blood of infertile patients participating in assisted reproduction programs

The association between levels of trace elements, endocrine diseases and reproductive impairments is actively investigated currently. In this connection, it seems relevant to study elemental status (elemental composition of blood and amounts of elements therein) of infertile patients enlisted in programs employing assisted reproductive technologies (ART). This study aimed to analyze trace elements in blood of infertile patients, relationship between the level of such trace elements and parameters of the ART programs they are in. The study included 30 infertile patients aged 18–39 years. Relying on inductively coupled plasma mass spectrometry, we identified concentrations of 31 chemical element in blood of the participants. Two elements out of 31 (antimony and beryllium) were not found in any blood sample; 10 elements (titanium, chromium, cobalt, nickel, arsenic, mercury, barium, gold, vanadium) were detected in some blood samples, the remaining 19 elements were found in all samples. Age of the patients correlated negatively with the level of silicon (r = –0.384; p = 0.036) and positively with the level of molybdenum (r = 0.384; p = 0.036). The level of anti-mullerian hormone was in a significant negative correlation with the level of lithium (r = –0.367; p = 0.046). The level of free thyroxine was in a significant negative correlation with the level of boron (r = –0.402; p = 0.028) and a positively correlated with the levels of iron (r = 0.410; p = 0.024) and silver (r = 0.432; p = 0.017). Considering the embryological cycle, we noted a positive correlation between the level of silicon and the number of blastocysts obtained (r = 0.387; p = 0.034). There was no statistical relationship registered between elemental composition of blood the frequency of pregnancy in ART cycles.