Tissue Barriers最新文献

Vocal fold organoids recapitulate critical structural and functional features of native vocal fold mucosa, providing a physiologically relevant model for investigating vocal fold biology and disease mechanisms. However, conventional histological processing of these organoids remains technically demanding, often resulting in substantial sample loss, inadequate visualization during embedding and difficult retrieval the blocks from Eppendorf tubes. To address these issues, we established a comprehensive protocol that integrates direct eosin pre-staining, agarose pre-embedding and fine-needle-assisted retrieval of agarose-embedded blocks. This optimized workflow increases processing efficiency, enables enhanced visual monitoring and better preserves cytoarchitectural integrity. Consequently, sectioning is facilitated, and both hematoxylin and eosin (HE) staining and immunofluorescence (IF) exhibit superior quality and reproducibility, producing highly consistent morphological details and robust signal resolution. The proposed method provides a standardized and reliable platform for high-resolution histological and IF examination of epithelial organoids, thereby extending its utility in vocal fold research and related organoid applications.

Diabetic neuropathy (DN) is a multifaceted and progressive complication of diabetes mellitus, characterized by functional and structural damage to peripheral, autonomic, and sensory nerves. Despite its high prevalence and debilitating consequences, current therapeutic approaches remain largely symptomatic, with limited disease-modifying strategies available. The pathogenesis of DN is driven by a complex network of molecular, cellular, and enzymatic interactions, primarily instigated by chronic hyperglycemia. This review unravels the intricate molecular and cellular crosstalk underlying DN, emphasizing the roles of specific cellular and enzymatic mediators in disease progression. Key cellular players, including neurons, Schwann cells, satellite glial cells, macrophages, and bone marrow-derived cells, orchestrate and respond to pathogenic stimuli, contributing to neuroinflammation, demyelination, and axonal degeneration. Chronic hyperglycemia activates several enzymatic pathways that exacerbate oxidative stress, mitochondrial dysfunction, and vascular impairment. Among the pivotal enzymes involved is aldose reductase, which drives the polyol pathway and sorbitol accumulation; diacylglycerol (DAG)-mediated protein kinase C (PKC), linked to vascular dysfunction; poly(ADP-ribose) polymerase (PARP), which amplifies DNA damage responses; and endogenous antioxidants, such as superoxide dismutase (SOD), catalase, and glutathione peroxidase, whose dysregulation further fuels oxidative injury. Additionally, growth factors (e.g. NGF, IGF-1, and VEGF), along with metabolic regulators (like AMPK), play pivotal roles in maintaining neuronal growth, survival, and function by modulating cellular energy homeostasis, oxidative balance, and inflammatory responses. By examining these interconnected molecular mechanisms, this review highlights potential therapeutic targets and proposes future directions for mechanism-based interventions aimed at halting or reversing the progression of diabetic neuropathy.

Glomerular podocytes, specialized epithelial cells, are central to the filtration function of vertebrate kidneys. Through their interdigitating foot processes, podocytes provide epithelial coverage to capillaries. They maintain selective filtration by allowing water, ions, and small solutes to filter while retaining proteins and larger molecules in the blood. The slit diaphragm (SD), a specialized junction between podocyte foot processes, along with glomerular basement membrane (GBM) and fenestrated endothelium, serves as a glomerular filtration barrier (GFB). Injury to GFB, such as loss of SD integrity and foot process effacement, compromises permselectivity and results in proteinuria. The SD consists of junctional proteins (nephrin, Neph1), adaptors (podocin, CD2AP), and channels (e.g. TRPC6), which assemble into a molecular sieve and a dynamic signaling hub. Monogenic mutations and resultant structural defects in SD components perturb podocyte filtration function, leading to proteinuria, nephrotic syndrome, and focal segmental glomerulosclerosis. This review summarizes structural and functional insights into SD architecture and emphasizes advances from biochemical, biophysical, and high-resolution imaging approaches. We particularly discuss the role of intrinsically disordered regions in mediating oligomerization and protein - protein networks within the SD. Emerging Cryo-EM studies further provide new perspectives on the stoichiometry of Nephrin - Neph1 complexes and their implications for SD ultrastructure. Finally, we outline unresolved questions regarding SD composition, assembly, and signaling, proposing how integrative structural biology may illuminate mechanisms underlying proteinuric kidney diseases.

Despite its widespread application in the treatment of cancer and autoimmune diseases, methotrexate (MTX) is associated with several adverse effects. Selenium nanoparticles (SeNPs) have antioxidant and anti-inflammatory effects. This study aimed to investigate the ameliorating effects of SeNPs against MTX-induced gastric fundus damage and the possible underlying mechanisms. Rats were randomly allocated into five groups: control group, SeNPs group, MTX group, and two SeNPs administered groups either prophylactic or concomitant. Physical and macroscopic evaluations were performed. Gastric fundus specimens were collected for biochemical and histological changes. The Methotrexate group showed a significant decrease in weight gain, food intake, and gastric total antioxidant capacity (TAC). Also, there was a disruption of the gastric epithelial barrier indicated by the significant decrease in occludin, E-cadherin gastric levels, and zonula occludens-1 (ZO-1) immune-expression, together with mucous barrier alteration indicated by a significant decrease in Periodic acid-Schiff (PAS) stain mean area fraction. While gastric malondialdehyde (MDA), toll-like receptors 4 (TLR4), and Myeloid differentiation primary response 88 (MYD88) levels, the nuclear factor kappa B (NF-κB) and cleaved caspase 3 immune-expression were significantly increased. Furthermore, histological assessment revealed mucosal ulceration, vascular congestion, and inflammatory cellular infiltration with a significant increase in mast cells. Surprisingly, SeNPs administration attenuated oxidative stress, apoptosis, and TLR4/NF-κB signaling. Moreover, a significant increase in occludin, E-cadherin, and ZO-1 and a significant decrease in mast cell number were noticed with SeNPs administration together with histological structure preservation. Notably, the prophylactic treatment with SeNPs caused more improvement than its concomitant administration.

Blood-brain barrier (BBB) dysfunction is an early event observed in Alzheimer's disease (AD). Two characteristics of AD brain and brain vasculature contribute to BBB dysfunction: the accumulation of aggregated amyloid-β protein (Aβ) and an increase in oxidative stress. This work uses a BBB model of primary human brain microvascular endothelial cells to investigate the individual and synergistic influence of both pathogenic Aβ oligomers and oxidative stress on BBB transendothelial electrical resistance (TEER), an indicator of barrier integrity. Results indicate that nontoxic, physiological concentrations of Aβ oligomers reduce TEER, while Aβ monomer remains inert. Moreover, introducing mild oxidative stress, which alone does not influence monolayer integrity, exacerbates the effect of Aβ oligomers on TEER within this BBB model. These findings advance the understanding of BBB dysfunction in AD and point toward therapeutic strategies targeting this early event that contributes to a currently irreversible disease.

Blood-tissue barriers (BTBs) are highly specialized, selectively permeable surfaces that separate the circulatory system from delicate tissues and organs. Critical examples include the blood-brain barrier (BBB), blood-retinal barrier (BRB), blood-testis barrier (BTB), and other organ-specific barriers, including the alveolar-capillary interface in the lungs and the glomerular filtration barrier in the kidneys. These barriers regulate the bidirectional transport of nutrients, gases, and waste while restricting pathogens, toxins, and immune cells to maintain physiological balance. Nevertheless, viruses have evolved multiple strategies to circumvent or compromise these barriers, facilitating viral entry, evading immune surveillance, and establishing infection within protected compartments. Neurotropic viruses, including the West Nile virus and Japanese encephalitis virus, impair the blood-brain barrier by disrupting tight junction proteins and cytokine storms. In contrast, respiratory viruses such as influenza and SARS-CoV-2 affect the lung barrier, resulting in alveolar injury and systemic inflammation. Other viruses, such as the Zika virus, affect the BTB and placental barriers, presenting significant risks to fetal development and reproductive health. Such breaches facilitate viral spread, exacerbate tissue damage, and complicate therapeutic interventions. This review provides a comprehensive overview of blood-tissue barrier architecture, function, and mechanisms of viral disruption, highlighting their dual role in protection and susceptibility during viral infections. By elucidating interactions between viruses and blood-tissue barriers, this work highlights emerging research directions to mitigate viral pathogenesis and enhance treatment efficacy for barrier-associated diseases.

Chronic rhinosinusitis with nasal polyps (CRSwNP) is a type 2 inflammatory disease associated with epithelial dysfunction and impaired mucosal barrier integrity. Dupilumab, an IL-4 receptor alpha antagonist, has shown clinical efficacy, but its cellular effects on nasal epithelium remain poorly understood. Advanced in vitro models such as 3D spheroid cultures may provide insight into epithelial organization under treatment. We conducted a preliminary study using nasal epithelial cells obtained from three patient groups: CRSwNP treated with Dupilumab for 16 weeks (n = 3), untreated CRSwNP (n = 3), and turbinate hypertrophy controls (n = 3). Cells were isolated by enzymatic digestion and cultured in ultra-low attachment plates using sphere-promoting medium to assess spheroid formation. Observations were performed using phase-contrast microscopy. Due to the limited sample size, data were analyzed qualitatively without statistical testing. Control cells formed compact spheroids, while untreated CRSwNP cells failed to generate structured spheroids, showing only aggregates. Cells from Dupilumab-treated patients produced well-organized spheroids, suggesting improved epithelial organization. Occasional surface movement was observed but not quantitatively assessed. No molecular or ultrastructural assays were performed to confirm mechanistic hypotheses. Our preliminary findings indicate that Dupilumab treatment may be associated with improved epithelial organization in CRSwNP, as shown by spheroid formation in 3D culture. However, these observations are preliminary and based on a small cross-sectional cohort. Future studies should include longitudinal sampling, functional assays, and molecular analyses to confirm mechanisms and validate these results.

Background: Parkinson's disease (PD) is the second most common neurodegenerative disorder, characterized by motor symptoms and progressive degeneration of dopaminergic neurons. Accumulating evidence indicates that mitochondrial dysfunction and oxidative stress are major contributors to PD pathogenesis.

Objectives: This review explores the molecular mechanisms underlying PD, emphasizing mitochondrial dysfunction and oxidative stress. It also examines genetic and environmental contributors, emerging biomarkers, and future treatment strategies.

Methods: An extensive literature review was conducted, focusing on mitochondrial biology, oxidative stress, genetic mutations, and environmental toxins relevant to PD. Investigations into treatment options - including redox therapies, gene therapies, and lifestyle approaches - were also examined.

Results: Mitochondrial dysfunction in PD includes disrupted oxidative phosphorylation and elevated reactive oxygen species (ROS). This also affects calcium homeostasis, especially in substantia nigra neurons. Genetic mutations (PINK1, Parkin, DJ-1, LRRK2, GBA) impair mitophagy and antioxidant defenses. Environmental toxins (e.g. MPTP, rotenone) further damage mitochondrial function and contribute to dopaminergic neuron loss. Emerging biomarkers involve measurements of lipid peroxidation and mitochondrial DNA damage. Promising therapeutic strategies include mitochondria-targeted antioxidants (e.g. MitoQ), PINK1-based gene therapy, Parkin activation, ketogenic diet, and exercise-induced mitochondrial biogenesis.

Conclusions: Mitochondrial dysfunction and oxidative stress are central to PD pathophysiology. Strategies targeting these mechanisms may slow disease progression. Future research should emphasize combination therapies and early intervention trials, alongside biomarker integration, to enhance clinical outcomes.

Tight junctions (TJ) comprise protein complexes that help with the movement of ions and molecules through the paracellular pathway, thus maintaining both epithelial and endothelial integrity. The TJ proteins are diverse and include claudins, occludins, tricellulins, cingulins, and junctional adhesion molecules (JAM). Claudins are transmembrane proteins that serve as critical components of TJs in epithelial and endothelial cells. The human genome comprises 23 claudin genes, with 27 transmembrane domains recognized in mammals. Ovarian cancer (OC) is the most lethal form of all gynecologic malignancies worldwide, characterized by poor prognosis and a recurrence rate of up to 75%. In OC, several claudins are overexpressed relative to normal ovarian tissue. These elevated expression observed among OC subtypes indicates their potential utility as diagnostic biomarkers. Claudins represent potential targets for innovative therapeutic strategies. Though their exact involvement in OC is still not well understood, they are believed to be crucial for cancer invasion and therapy resistance. Recent studies show that claudins are involved in the EMT pathway and ERK, enlightening the effect of claudins in drug resistance. Clostridium perfringens enterotoxin (CPE) demonstrates potential as a therapy targeting claudins, specifically claudin-3 and -4, which serve as receptors for this toxin. Despite these advancements, challenges remain in comprehensively understanding claudin functions and in the development of effective claudin-targeted therapies. This review consolidates existing knowledge regarding claudins in OC, focusing on their expression patterns, biological functions, diagnostic and prognostic significance, and therapeutic implications. A thorough understanding of claudins in OC establishes a basis for enhancing diagnostic, predictive, and therapeutic approaches, which may result in improved therapy outcomes.

The restoration of cutaneous barrier function following deep skin injury remains a critical challenge in regenerative medicine. In this study, we developed a semi-occlusive wound dressing by combining sodium alginate hydrogel with platelet-rich plasma (PRP), using 3D bioprinting technology to ensure structural precision and consistent bioactive distribution. This hybrid system was engineered to support tissue repair by enhancing re-epithelialization, stimulating angiogenesis, and promoting organized extracellular matrix remodeling. In vivo experiments using full-thickness skin wounds in mice revealed that the PRP enriched dressings accelerated wound contraction and epithelial closure, especially during the early stages of healing. Histological analyses showed increased formation of capillary-like structures, a shift toward type I collagen dominance, and reduced inflammation in PRP treated groups. These effects point to a more mature and functional regenerative process. Importantly, the combination of PRP with a bioprinted hydrogel scaffold not only facilitated structural recovery but also contributed to restoring the physiological integrity of the skin barrier. This approach offers a low-cost and adaptable platform with strong translational potential for the treatment of complex skin wounds.