Tissue Barriers最新文献

Traumatic brain injury (TBI) is a leading cause of death and disability in patients. Brain microvasculature endothelial cells form the blood-brain barrier (BBB) which functions to maintain a protective barrier for the brain from the passive entry of systemic solutes. As a result of the cellular disruption caused by TBI, the BBB is compromised. Tight junction disruption in the endothelium of the BBB has been implicated in this response, but the underlying mechanisms remain unresolved. We utilized various in vivo models of severe to mild TBI as well as in vitro exposure of brain endothelial cells (bEND.3) to analyze conditions encountered following TBI to gain mechanistic insight into alterations observed at the BBB. We found that claudin-1 (CLDN1), was significantly increased in the brain endothelium both in vivo and in vitro. The observed increase of CLDN1 expression correlated with down-regulation of claudin-5 (CLDN5), occludin (OCLN), and zonula occludens (ZO-1), thereby altering BBB integrity by decreasing TEER and increasing permeability. Knockdown of CLDN1 in these pathogenic conditions showed stability of the endothelial junctional proteins. A decline in the epigenetic regulator silent information regulator family protein 1 (SIRT1), a member of the NAD+ dependent protein deacetylases, coincided with this upregulation of CLDN1. Indeed, the quenching of oxidative stress through NAC treatment was able to reduce injury-induced upregulation of CLDN1 in vitro. Mechanistically, an SRC-dependent tyrosine phosphorylation of OCLN and ZO-1 in CLDN1-modulated conditions was observed. Our findings will provide new insights into BBB deregulation and new possible treatment opportunities for TBI.

Adenoid organoids, as the primary immune barrier of the airway, provide valuable models for studying lymphatic tissue function, but their histological processing remains challenging due to their fragile structure and lack of adhesion. Here, we introduce a novel approach that combines eosin pre-staining with agarose pre-embedding to enhance visibility and structural integrity during paraffin embedding. This method simplifies sectioning and improves the quality of hematoxylin and eosin (HE) and immunofluorescence (IF) staining, yielding clear and stable signals. By addressing key limitations in lymphatic organoid processing, this technique provides a reliable solution for histological and IF studies, facilitating future research on adenoid organoids.

Ginseng, a well-known herbal supplement, is widely recognized for its pharmacological properties, including anti-inflammatory, antioxidant, and immune-modulatory effects. This review explores the potential therapeutic benefits of ginseng, particularly its active compounds, ginsenosides, in promoting nasal mucosa health. The nasal mucosa plays a crucial role in respiratory defense, acting as a barrier to pathogens and particulate matter, while also orchestrating immune responses. Ginseng's bioactive compounds have shown promise in modulating inflammation, reducing oxidative stress, and enhancing immune functions, which could be beneficial in conditions such as allergic rhinitis, chronic rhinosinusitis, and viral infections. Histological studies highlight the impact of ginseng on nasal mucosal cells, particularly in regulating immune responses and promoting tissue resilience. Research demonstrates that ginseng can reduce inflammation in the nasal passages by inhibiting pro-inflammatory cytokines and pathways like NF-κB, while enhancing the activity of immune cells such as natural killer cells and macrophages. Furthermore, ginseng's antioxidant properties help protect nasal tissue from oxidative damage, which is common in chronic nasal conditions. Although promising, the evidence base is still developing, with many studies limited by small sample sizes and variations in ginseng preparations. Further clinical trials are needed to substantiate ginseng's efficacy, optimal dosage, and delivery methods for treating nasal conditions. This review provides insights into the potential of ginseng as a complementary therapeutic approach for enhancing nasal mucosa health and improving respiratory outcomes.

Friedreich's Ataxia (FRDA) is a neurodegenerative disease that affects a variety of different organ systems. The disease is caused by GAA repeat expansions in intron 1 of the Frataxin gene (FXN), which results in a decrease in the expression of the FXN protein. FXN is needed for the biogenesis of iron-sulfur clusters (ISC) which are required by key metabolic processes in the mitochondria. Without ISCs those processes do not occur properly. As a result, reactive oxygen species accumulate, and the mitochondria cease to function. Iron is also thought to accumulate in the cells of certain tissue types. These processes are thought to be intimately related to the pathologies affecting a myriad of tissues in FRDA. Most FRDA patients suffer from loss of motor control, cardiomyopathy, scoliosis, foot deformities, and diabetes. In this review, we discuss the known features of FRDA pathology and the current understanding about the basis of these alterations.

Arrestins and integrin-linked kinase (ILK) are important scaffold proteins that regulate myriad cell functions in metazoans. β-arrestins, first identified as critical components in G-protein-coupled receptor (GPCR) signaling pathways, participate in inflammatory, immunomodulatory and tissue repair processes in GPCR-dependent and -independent manners. ILK is a central mediator of signaling cascades elicited by activation of integrins, regulating cell motility, proliferation, and mechanotransduction. In the epidermis, ILK is essential for maintenance of barrier function, hair follicle development, melanocyte colonization and regeneration after injury. In this tissue, β-arrestin 2 mitigates inflammatory processes and development of allergic dermatitis, which also is associated with loss of epidermal barrier function. However, the functional role of β-arrestin 1 in epidermal cells is poorly understood. We now report that β-arrestin 1 directly binds ILK, forming hitherto unidentified protein complexes in epidermal keratinocytes. In the absence of exogenous GPCR ligand stimulation, β-arrestin 1 and ILK are found throughout the cytoplasm in epidermal keratinocytes, and also co-localize to plasma membrane regions associated with cell protrusions. Inactivation of the genes that encode both β-arrestin 1 and 2 attenuates forward cell migration, whereas expression of ILK together with β-arrestin 1 restores cell motility. The cooperative effect of ILK and β-arrestin 1 in promoting directional cell migration may have important implications for epidermal regeneration and reestablishment of barrier function after injury.

Eph receptor-interacting proteins (ephrin) ligands and their erythropoietin-producing human hepatocellular (Eph) receptors elicit bidirectional signals that regulate cell migration, angiogenesis, neuronal plasticity, and other developmental processes in the embryo. In adulthood, ephrin-Eph signaling regulates numerous homeostatic events, including epithelial cell proliferation and differentiation. Epithelial surfaces, including those of skin and vagina, are lined by layers of stratified squamous epithelium (SSE) that protect against mechanical stress and microbial pathogen invasion. Ephrin-Eph signaling is known to promote cutaneous epithelial barrier function by regulating the expression of specialized cell-cell adhesion junctions termed desmosomes, but the role of this signaling system in maintaining epithelial integrity and barrier function in the vagina is less explored. This review summarizes current understanding of ephrin-Eph signaling that regulates desmosome expression and barrier function in the skin and considers evidence that suggests ephrin-Eph signaling similarly regulates these processes in vaginal SSE.

Modulation of claudin-based bicellular tight junction (TJ) and angulin-based tricellular TJ seals has been shown to enhance mucosal permeation of macromolecules, by using the receptor-binding fragments of Clostridium perfringens enterotoxin (C-CPE194, C-CPEmt, and C-CPEm19) and Clostridium perfringens iota-toxin (angubindin-1) as claudin modulators and an angulin modulator, respectively. Here, we compared the activity of these modulators on the TJ in human intestinal Caco-2 cells. All the claudin modulators loosened TJ integrity more potently compared to angubindin-1 with the order of potency being C-CPEm19 > C-CPE194 > C-CPEmt, and results for permeation enhancement were similar. Treatment with C-CPEmt and C-CPE194 at 100 µg/mL for 48 h enhanced the permeation of dextran sized 20 kDa and 70 kDa, respectively. Treatment with C-CPEm19 at 30 µg/mL for 48 h enhanced permeation of dextran with a molecular mass of up to 150 kDa. Furthermore, co-treatment of bicellular TJ modulators, such as C-CPEmt, C-CPE194, and C-CPEm19, and tricellular TJ modulators, such as angubindin-1, showed additive TJ-loosening and permeation-enhancing activities compared with individual treatments; specifically, C-CPEm19 and angubindin-1 co-treatment increased permeation of large molecules (70 kDa and 150 kDa). These findings indicate that TJ modulators may be used as size-selective permeation enhancers.

Crohn's disease is a form of inflammation that affects the gastrointestinal (GI) tract. It is characterized by persistent inflammation in the gut, which can lead to the formation of abnormal connections called fistulas. These fistulas can occur between the GI tract and the abdominal cavity, adjacent organs, or the skin. The most prevalent type of fistula in Crohn's disease patients is the perianal fistula, which forms between the rectum and the skin near the anus. Although the exact cause of fistula formation is not fully understood, research suggests that factors such as epithelial to mesenchymal transition, matrix metalloproteinase, immune system dysregulation, and microbiota may contribute to their development. There is currently no definitive treatment for fistula closure, but options include surgery, endoscopic procedures, antibiotics, biologic agents, and immunosuppressive drugs. These treatments can be used alone or in combination. However, recurrence is a significant challenge that needs to be addressed in the case of fistula treatment. This review provides an overview of the common types of fistulas, their characteristics, the main factors and mechanisms of fistula formation, and available therapeutic options.

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are the result of an exaggerated inflammatory response triggered by a variety of pulmonary and systemic insults. The lung tissues are comprised of a variety of cell types, including alveolar epithelial cells, pulmonary vascular endothelial cells, macrophages, neutrophils, and others. There is mounting evidence that these diverse cell populations within the lung interact to regulate lung inflammation in response to both direct and indirect stimuli. The aim of this review is to provide a summary and discussion of recent advances in the understanding of the importance of cell-cell crosstalk in the pathogenesis of ALI/ARDS, with a specific focus on the cell-cell interactions that may offer prospective therapeutic avenues for ALI/ARDS.

Cardiovascular diseases are a significant global health challenge and pervasive cause of mortality worldwide. Heart failure due to cardiovascular disease is characterized by the inability of the heart to pump blood efficiently to meet the metabolic demands of the body. The pathophysiology of heart failure involves myocardial remodeling due to excessive deposition of extracellular matrix proteins by cardiac myofibroblasts - structural changes which impair contractility, reduce compliance, and ultimately reduce stroke volume. Now, a recent report has uncovered an essential role for Iroquois homeobox 2 in the transcriptional regulation of cardiac fibrosis, illuminating new mechanistic insights that can be applied to developing future clinical therapies.