Combined exposure to environmental noise and carbon monoxide (CO) poses a growing threat to male reproductive health, yet the mechanisms underlying their combined toxicity remain incompletely understood. This study investigated the effects of combined noise and CO exposure on Sertoli cells and the blood-testis barrier (BTB), explored the potential epigenetic mechanisms involved, and evaluated the protective efficacy of pterostilbene (PTE) in male rats. Animals were exposed to noise (85 dB), CO (410 ppm), or both for 2 h/day over 60 days, with a subset receiving PTE (80 mg/kg/day). Combined exposure, but neither stressor alone, induced significant Sertoli cell loss, suppressed inhibin-B(INH-B) secretion, and disrupted BTB ultrastructure, accompanied by the coordinated downregulation of multiple junctional proteins including ZO-1, N-cadherin, and Claudin family members. Integrative transcriptomic and methylomic analyses suggested that this multi-target junctional impairment was associated with promoter hypermethylation-mediated transcriptional silencing, with Cldn5, Cldn9, Cldn18, and Cldn22 identified as representative targets. PTE co-treatment attenuated the aberrant methylation, restored junctional protein expression, and preserved BTB structural integrity. These findings suggest that promoter hypermethylation of BTB junctional genes may represent an important epigenetic mechanism underlying co-exposure-induced reproductive toxicity, and that PTE may serve as a promising protective intervention for populations at risk of combined environmental exposure.

Tannic acid (TA) emerges as a promising anti-osteosarcoma agent. The application of TA in combination with cisplatin demonstrated promising synergistic activity with significant growth inhibitory and apoptotic effects. However, detailed surface ultramorphological alterations and the underlying mechanism of action are yet to be elucidated. Therefore, this study investigated the ultramorphological alterations and key mechanistic actions of TA and its combination with cisplatin against human osteosarcoma (U2OS) cells. The ultramorphological alteration of U2OS cells was evaluated using a scanning electron microscope (SEM). The mRNA expressions of key markers in mitogen-activated protein kinase (MAPK) and apoptotic pathways were evaluated using reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). Although surface ultramorphological alteration of U2OS cells was noted across all treatment groups, the combination treatment induced more prominent alteration. The cells appeared shrunk, with blebbed membranes and reduced appearance of lamellipodia and filopodia. Mechanistically, the combination of TA and cisplatin enhanced the former's anti-proliferative and apoptotic effects by upregulating the mRNA expression of ERK2, BAX, caspase-9, and caspase-3, and downregulating JNK1 and BCL-2. Therefore, the findings suggested that TA and its combination with cisplatin might exerted anti-proliferative and pro-apoptotic effects and induced surface ultrastructural changes in U2OS cells. These effects may be associated with ERK2, JNK1, and intrinsic apoptosis pathways, although further protein-level validation is required.

Eggshell quality is an important indicator of the nutritional status, health, and welfare of laying hens and plays a key role in minimizing economic losses and maintaining egg marketability during extended laying cycles. During the late laying period, aged hens commonly exhibit progressive eggshell thinning and reduced shell strength, which increase egg breakage and limit productive lifespan. Although shell gland dysfunction has been implicated in eggshell deterioration, how intestinal microbial remodeling, host metabolism, and shell gland function are coordinated during this process remains unclear. In this study, we integrated eggshell phenotyping, shell gland histology, cecal microbiota profiling, metabolomics, and transcriptomics in Guizhou Recessive White-feather chickens at peak and late laying stages. We found that late-laying hens displayed impaired eggshell ultrastructure and shell gland mucosal degeneration, accompanied by a shift from Lactobacillus- and Limosilactobacillus-enriched microbiota to a dysbiotic community characterized by increased Escherichia-Shigella. Multi-omics analyses revealed disrupted tryptophan metabolism, altered indole-3-pyruvic acid and indoleacetic acid levels, and extensive remodeling of shell gland energy metabolism, including oxidative phosphorylation and the tricarboxylic acid cycle. Key genes related to mitochondrial function and calcium transport, including MFN1, MDH1, ATP2A3, and SLC8A1, were dysregulated, suggesting impaired mitochondrial homeostasis and calcium handling in the shell gland. Integrated analysis further linked microbial genera, tryptophan-related metabolites, shell gland genes, and eggshell quality traits, supporting a coordinated gut microbiota-host metabolism-shell gland axis. These findings provide a systems-level view of eggshell deterioration in aged laying hens and identify potential microbial and metabolic targets for improving eggshell quality during extended laying cycles.

The double-membrane nature of mitochondria generates an intermembrane volume through which ions, reactive oxygen species, and metabolites must flux to reach the matrix or cytosol, but whether this volume is a genetically specified structure remains unknown. We identify SPRIZ (spatial regulator of the intermembrane zone), the product of Ccdc127, a gene conserved across deuterostome animals. SPRIZ assembles into an ∼18-nanometer homodimeric tether anchored in the outer mitochondrial membrane (OMM) and inserted into the inner mitochondrial membrane (IMM) through vertebrate-specific hydrophobic loops, physically spacing the two membranes and setting local intermembrane volume. Cryo-electron tomography of native mitochondria revealed rod-like densities spanning the intermembrane space (IMS), consistent with SPRIZ's predicted rigid coiled-coil architecture and membrane-spanning topology. In mouse liver, two-dimensional morphometry measured ∼3-fold expansion of IMS area with SPRIZ and ∼5.5-fold with lengthened mitochondrial artificial increaser of the IMS (MARTINI); 3D electron tomography confirmed MARTINI's greater OMM-IMM separation and normalized IMS volume. This expansion was functionally validated by increased 14C-mannitol accessibility to the IMS and by impaired mitochondrial Ca2+ uptake. Constitutive Ccdc127/SPRIZ knockout produced viable mice and, in liver mitochondria, preserved overall ultrastructure but caused modest IMS expansion, consistent with loss of local OMM-IMM constraints that stabilize membrane geometry at discrete sites. We therefore identify IMS volume as a genetically encoded and tunable architectural parameter of vertebrate mitochondria. In this model, SPRIZ is a molecular spacing system that locally sets OMM-IMM separation, shaping the environment through which metabolites, ions, and signals diffuse and establishing local gradients within the IMS.

Neonatal bacterial meningitis (NBM) is a severe neonatal infectious disease associated with a high incidence of neurological sequelae. Lipopolysaccharide (LPS) and inflammatory cytokines aggravate cerebral injury, whereas the mechanism of ferroptosis in the pathogenesis of NBM remains unclear. Melatonin (MT), an endogenous neurohormone, provides anti-ferroptotic neuroprotection in models of cerebral injury; however, its mechanism of action against NBM-related injury through ferroptosis has not been clarified. This study investigated the protective effects mediated by MT in vivo and in vitro. Rat models of LPS-induced inflammatory brain injury were established through intracerebroventricular (i.c.v.) injection, and Escherichia coli (E. coli)-infected cell models were developed to investigate the neuroprotective effects of MT against TFRC-related ferroptosis. CCK-8 assays, Western blotting, transmission electron microscopy (TEM), iron detection, and immunofluorescence, BODIPY staining were used to assess cell viability, inflammatory factors, mitochondrial ultrastructure, iron accumulation, and GPX4 expression. E. coli infection induced typical ferroptotic mitochondrial damage. MT alleviated neuroinflammation and reduced the expression of ferroptosis-related proteins both in vitro and in vivo. MT treatment increased mitochondrial GPX4 expression. The ferroptosis agonist RSL3 reversed the neuroprotective effects of MT. MT inhibited TFRC-related ferroptosis and alleviated neuronal damage. MT protects against E. coli/Lipopolysaccharide induced neuronal injury by regulating TFRC-related ferroptosis, indicating that MT may be a promising therapeutic agent for NBM.

Aminoglycoside-induced hearing loss is closely associated with oxidative stress and mitochondrial dysfunction in cochlear hair cells, but the upstream epigenetic mechanisms remain incompletely understood. This study investigated whether histone deacetylase 1 (HDAC1) contributes to neomycin-induced cochlear injury through transcriptional repression of NRF2. In HEI-OC1 cells, neomycin increased apoptosis, reactive oxygen species accumulation, mitochondrial depolarization, and mitochondrial superoxide production, accompanied by HDAC1 upregulation and NRF2 suppression. HDAC1 silencing attenuated these alterations and restored NRF2 expression. ChIP-qPCR demonstrated increased HDAC1 occupancy and reduced H3K27ac enrichment at the proximal NRF2 promoter after neomycin exposure, whereas HDAC1 knockdown reversed these changes. Consistently, HDAC1 silencing increased NRF2 promoter activity, while HDAC1 overexpression further suppressed NRF2 transcription and reduced H3K27ac levels. HDAC1 knockdown also restored nuclear NRF2 abundance and increased the downstream antioxidant proteins HO-1 and NQO1. Importantly, NRF2 overexpression partially rescued the reductions in cell viability and ATP content caused by HDAC1 overexpression, supporting a functional role for NRF2 downstream of HDAC1. In vivo, valproic acid partially preserved auditory thresholds, reduced cochlear hair cell apoptosis, restored NRF2 expression, and ameliorated mitochondrial ultrastructural damage in neomycin-treated mice. Collectively, these findings identify HDAC1-associated H3K27ac remodeling at the NRF2 promoter as an epigenetic mechanism contributing to neomycin-induced cochlear hair cell injury and support HDAC1-NRF2 regulation as a potential target for otoprotection.

Acquired corneal subepithelial hypertrophy (ACSH) is a rare corneal condition whose ultrastructural features have not previously been characterized. We report the first detailed ultrastructural analysis of ACSH in a 57-year-old man with a history of penetrating keratoplasty for corneal trauma followed by Descemet stripping automated endothelial keratoplasty who presented with progressive visual decline due to a superficial corneal opacity. Clinical evaluation included slitlamp biomicroscopy, anterior segment optical coherence tomography, corneal topography, and pachymetry, which localized the lesion to the subepithelial compartment. The lesion was managed with selective surgical peeling, and the excised tissue was examined by light microscopy and transmission electron microscopy. Surgical removal led to restoration of best-corrected visual acuity with no recurrence at 1-year follow-up. Histopathological analysis demonstrated irregular epithelial thickening, complete absence of Bowman layer, and subepithelial fibrosis with myofibroblast proliferation, without evidence of inflammation or neovascularization. Ultrastructural examination revealed epithelial mitochondrial damage with mitophagy, disruption of intercellular junctions, and subepithelial myofibroblasts containing abundant rough endoplasmic reticulum, consistent with active fibrotic remodeling. These findings support ACSH as an acquired corneal fibrotic process driven by wound healing mechanisms, with clinical, epidemiological, and histopathological features distinct from other corneal degenerations and confirmed that surgical peeling of the thickened epithelial and subepithelial tissue can be curative.

Triatomines are the primary vectors of Trypanosoma cruzi (Chagas), the causative organism of Chagas disease, one of the most important vector-borne diseases in Mexico. Triatomine dispersal encompasses a broad spectrum of flight capacities, ranging from short-distance, low-altitude flights to active, sustained dispersal in certain species. Although recent studies have examined the phenotypic and genetic variability of flight-related traits, the specific morphological constraints hindering their aerodynamic efficiency remain poorly understood. Therefore, this study aimed to provide a comparative ultrastructural description of the wing-coupling apparatus (coaptor) in seven North American triatomine species: Triatoma bassolsae (Alejandre et al.), T. picturata (Usinger), T. pallidipennis (Stål), T. longipennis (Usinger), T. rubida (Uhler), T. mazzottii (Usinger), and Paratriatoma lecticularia (Stål). Using light and scanning electron microscopy (SEM), the topography of the ctenidia, the mechanical gap, and imbricated scale-like structures were characterized. The results revealed a consistent tripartite morphological pattern across all species; however, all the species exhibited a central morphological discontinuity separating the ctenidium from the posterior rugose prominence. Ctenidial bristle count showed interspecific variation, ranging from 16 visible bristles in T. rubida to 33 in T. bassolsae. These counts corresponded to the anterior row of the ctenidium captured in SEM micrographs at 500× magnification. These findings provide high-resolution diagnostic cuticular characters for species differentiation and led to the hypothesis that a structural discontinuity along the hemelytron margin may influence functional wing coupling. This study highlights the importance of ultrastructural analysis in providing high-resolution diagnostic traits to complement traditional taxonomy and understanding Triatominae functional morphology.

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most prevalent chronic liver disease. Due to its complex pathophysiology, treatment options remain limited. Transforming growth factor β (TGF-β) is a pleiotropic cytokine involved in the regulation of liver fibrosis and metabolism. Previously, we have demonstrated the antifibrotic effect of TβRII-SE/Fc delivered by a lentiviral vector (Lv) in a liver fibrosis model. TβRII-SE/Fc is a fusion protein composed of the soluble isoform of the TGF-β type II receptor (TβRII-SE) and the human IgG-Fc domain. In this study, we evaluated the potential of TβRII-SE/Fc to attenuate key metabolic and hepatic features in an early stage MASLD model using lentiviral-mediated hepatic overexpression. We studied the effect of intrahepatic administration of Lv.TβRII-SE/Fc in a rat MASLD model induced by a Western diet. To achieve that, body composition-related parameters, biochemical, histological, ultrastructural, and RT-qPCR analyses were performed. Intrahepatic delivery of Lv.TβRII-SE/Fc is associated with improvements in several features of MASLD: (i) Attenuated liver microvesicular steatosis. (ii) Reduced liver fibrosis, together with decreased IL-6 and TGF-β2 gene expression. (iii) Changes in the expression of genes associated with free fatty acid (FFA) utilization, uptake, and de novo lipogenesis in the liver. (iv) Reduced lipid droplet accumulation and mitochondrial swelling, consistent with preserved hepatocellular ultrastructure. (v) Ameliorated insulin resistance (IR) and decreased basal serum glycemia, and (vi) reduced abdominal circumference (AC) and epididymal fat mass. Our findings suggest that TβRII-SE/Fc may represent a promising therapeutic candidate for early stage MASLD, with beneficial effects on liver steatosis, fibrosis, and metabolic dysfunction.

Myocardial fibrosis (MF), characterized by excessive collagen deposition, represents an inevitable pathological progression toward end-stage heart disease, underscoring the urgent clinical need for effective reversal strategies. In recent years, the mitochondrial quality control (MQC) system has emerged as a central regulatory hub for maintaining cardiac homeostasis, offering novel insights into the prevention and treatment of MF. This review bridges classical Traditional Chinese Medicine (TCM) therapeutic concepts with modern MQC mechanisms, primarily aiming to evaluate the intervention targets and efficacy of TCM monomers and formulas by detecting alterations in mitochondrial-associated protein expression, gene transcription levels, and organelle ultrastructure. By systematically reviewing experimental evidence of TCM-mediated MQC modulation, this paper highlights the multi-target and systematic advantages of TCM in combating MF, thereby injecting new momentum into the development of contemporary anti-MF therapeutics.