An easy prepared probe, BHMMP, was designed and synthesized, which displayed a significant fluorescence enhancement (over 38-fold) and obvious color change in the recognition of Al³⁺. The binding ratio of probe BHMMP to Al³⁺ was determined as 1:1, according to Job plot. The binding mechanism was fully clarified by the experiments, such as FT-IR spectrum, ESI–MS analysis, and ¹H NMR titration. A DFT study further confirmed the binding mode of BHMMP to Al³⁺. The limit of detection (LOD) for Al³⁺ was determined as low as 0.70 µM, based on the fluorescence titration of BHMMP. Moreover, the results from real sample experiments, including real water samples, test papers, and cell images, well-demonstrated that BHMMP was capable of sensing Al³⁺ in environmental and biological systems.

Multiple morphological abnormalities of the sperm flagellum (MMAF) have been reported to be an important cause of male infertility and reflect a heterogeneous genetic disorder. Previous studies have identified dozens of candidate pathogenic genes for MMAF, but the aetiology in approximately 50% of cases remains unexplained. The present study aimed to identify novel potentially pathogenic gene variants of MMAF. A Chinese family with a 32-year-old infertile proband presenting with MMAF was recruited, and sperm morphology of the patient was examined by Papanicolaou staining. Whole exome sequencing was performed on the proband and Sanger sequencing was used to identify genetic variants in the family. The frequencies of variants were assessed using public databases and the effects on protein structure and function were predicted by online bioinformatics tools. The patient exhibited asthenozoospermia and a MMAF phenotype. Novel compound heterozygous variants (c.5368C > T, p.R1790C and c.13183C > T, p.R4395W) of the DNAH17 gene were identified in the patient, and showed autosomal recessive inheritance in this family. These variants were very rare in the GnomAD database. The two mutated amino acids were located in a highly conserved region of the DNAH17 protein. In silico analysis revealed that the compound heterozygous variants may compromise the function of DNAH17. Our findings expand upon the spectrum of pathogenic DNAH17 variants that are responsible for MMAF, and provide new knowledge for genetic counselling of male infertility due to MMAF.

Aluminum has been recognized as a reproductive toxin, yet the precise mechanisms by which embryonic exposure impairs male offspring development remain largely unclear. The key point is that no systematic adverse outcome pathway (AOP) network has yet been established to link aluminum exposure with reproductive disorders. This study employed an integrated approach-combining network toxicology and non-targeted metabolomics, and in vivo/in vitro experiments-to establish a novel AOP elucidating how aluminum induces spermatogenesis impairment in mice. Mechanistically, in vitro studies using mouse TM3 and primary Leydig cells demonstrated that aluminum chloride (AlCl₃) triggers oxidative stress, leading to endoplasmic reticulum stress (ERS), via the IRE1α/XBP1s pathway. We identified that the transcription factor XBP1s directly binds to and transactivates the promoter of N-acylphosphatidyl-ethanolamine-specific phospholipase D (Nape-pld). This cascade results in overactivation of the cannabinoid receptor 1 (CB1) and the downregulation of key steroidogenic proteins, Luteinizing Hormone Receptor (LHR) and Steroidogenic Acute Regulatory Protein (StAR). These findings provide compelling evidence for our AOP model, wherein aluminum induces ERS via oxidative stress, subsequently impairing testosterone synthesis through the endocannabinoid system (ECS). Our research advances the assessment of heavy metal reproductive risks by offering a robust methodology for identifying key events (KEs) and constructing causal AOP networks.

Exposure to environmental pollutants during development has been implicated in causing reproductive dysfunction in adult male mice, yet the specific molecular mechanisms by which certain pollutants induce such damage remain poorly understood. Methyl ester sulfonate (MES), a widely used anionic surfactant marketed as a "green" alternative, lacks a comprehensive assessment of its reproductive toxicity. To address this knowledge gap, we established a mouse model of developmental exposure, administering MES (0.06, 0.6, and 6 mg/L) via drinking water from gestational day (GD) 8.5 to postnatal day (PND) 56. Our results showed that developmental MES exposure induced significant histopathological alterations in adult male testes, including impaired blood-testis barrier (BTB) integrity, disorganized spermatocyte alignment, seminiferous tubule vacuolation, and testicular fibrosis. These structural defects were accompanied by significantly reduced serum testosterone and impaired spermatogenesis. Mechanistically, we combined RNA sequencing, molecular docking, and cell thermal shift assay-Western blotting (CETSA-WB) to uncover a novel pathway in Leydig cells (LCs). We demonstrated that MES directly bound to and stabilized the transcription factor GATA binding protein 2 (GATA2), which in turn activated the transforming growth factor-β1 (TGF-β1)/SMAD signaling pathway. This cascade suppressed luteinizing hormone receptor (LHR) expression, ultimately impairing testosterone synthesis. This study provides the first mechanistic evidence of MES induced reproductive toxicity in mammals, challenging its safety profile and highlighting a novel GATA2/TGF-β1/LHR axis that governs steroidogenesis. Our findings underscore the urgent need for a thorough environmental risk assessment of MES.