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26 result(s) for "Baek, Seung-Kuk"
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Usefulness of matrix metalloproteinase-7 in saliva as a diagnostic biomarker for laryngopharyngeal reflux disease
Several diagnostic methods are currently being used to diagnose LPRD (laryngopharyngeal reflux disease), but have the disadvantage of being invasive, subjective, or expensive. Our purpose in this study was to investigate the correlation between pepsin and MMP-7 (Matrix Metalloproteinase-7) in pharyngeal secretions of subjects according to RSI (Reflux Symptom Index) score to find out the diagnostic value of MMP-7. We recruited 173 subjects aged between 19 and 85 years who completed the RSI scale. All samples were taken after waking up, and the amount of the pepsin and MMP-7 in saliva were measured by means of an enzyme activity assay. There was a significant increase of pepsin and MMP-7 activity in the study group with an RSI score of 13 or higher. The sensitivity and specificity of MMP-7 for predicting the possibility of an RSI of 13 or more was higher than that of pepsin. When MMP-7 and pepsin were combined, this sensitivity and specificity increased. An enzyme assay of MMP-7 in saliva may be a noninvasive and easy technique for diagnosing LPRD.
Establishing a Non-Surgical Mouse Model of Laryngopharyngeal Reflux Disease: Acid-Induced Epithelial Disruption and Protective Role of N-Acetylcysteine
Laryngopharyngeal reflux disease (LPRD) results from the retrograde flow of gastric contents into the upper aerodigestive tract, causing epithelial injury. Progress in its management has been limited by the lack of objective biomarkers and reproducible in vivo models. This study aimed to establish a chronic, non-surgical mouse model of LPRD and to investigate the protective effect of N-acetylcysteine (NAC). Female C57BL/6 mice were randomly assigned to three groups: control (standard drinking water), study (acidified water, pH 3.0, for 12 weeks), and treatment (acidified water for 12 weeks plus NAC supplementation during the final 4 weeks). Body weight, food intake, and water consumption were monitored weekly. Pharyngeal tissues were analyzed by immunohistochemistry and Western blotting. Chronic acid exposure resulted in loss of membrane-localized E-cadherin, cytoplasmic redistribution, and upregulation of matrix metalloproteinase-7 (MMP-7). These molecular alterations were accompanied by enhanced phosphorylation of ERK and c-Jun, consistent with activation of the ROS–ERK–c-Jun signaling pathway. NAC supplementation was associated with partial restoration of E-cadherin, reduced MMP-7 expression, and attenuation of ERK/c-Jun phosphorylation. No systemic toxicity or weight loss was observed, indicating good tolerability of the model. This non-surgical ingestion-based model faithfully recapitulates key epithelial features of LPRD and provides a feasible platform for mechanistic investigation and exploratory therapeutic studies. NAC may exert protective effects against acid-induced epithelial injury in this model.
The Inhibitory Effect of Hedera helix and Coptidis Rhizome Mixture in the Pathogenesis of Laryngopharyngeal Reflux: Cleavage of E-Cadherin in Acid-Exposed Primary Human Pharyngeal Epithelial Cells
Laryngopharyngeal reflux disease (LPRD) is a prevalent upper airway disorder characterized by inflammation and epithelial damage due to the backflow of gastric contents. Current treatments, primarily proton pump inhibitors (PPIs), often show variable efficacy, necessitating the exploration of alternative or adjunctive therapies. This study investigates the therapeutic potential of a mixture of Hedera helix and Coptidis rhizome (HHCR) in mitigating the pathophysiological mechanisms of LPRD. Using an in vitro model of human pharyngeal epithelial cells exposed to acidic conditions, we observed that acid exposure significantly increased the expression of adenosine A3 receptor (adenosine A3) and matrix metalloproteinase-7 (MMP-7), leading to E-cadherin cleavage and compromised epithelial integrity. Treatment with the HHCR mixture effectively suppressed adenosine A3 expression and MMP-7 activity, thereby reducing E-cadherin cleavage and preserving cellular cohesion. These results highlight the HHCR mixture’s ability to modulate the adenosine A3–MMP-7–E-cadherin pathway, suggesting its potential as a valuable adjunctive therapy for LPRD, particularly for patients unresponsive to conventional PPI treatment. This study provides new insights into the molecular interactions involved in LPRD and supports further clinical evaluation of HHCR as a complementary treatment option.
Identification of urban particulate matter-induced disruption of human respiratory mucosa integrity using whole transcriptome analysis and organ-on-a chip
Background Exposure to air particulate matter (PM) is associated with various diseases in the human respiratory system. To date, most in vitro studies showing cellular responses to PM have been performed in cell culture using a single cell type. There are few studies considering how multicellular networks communicate in a tissue microenvironment when responding to the presence of PM. Here, an in vitro three-dimensional (3D) respiratory mucosa-on-a-chip, composed of human nasal epithelial cells, fibroblasts, and endothelial cells, is used to recapitulate and better understand the effects of urban particulate matter (UPM) on human respiratory mucosa. Results We hypothesized that the first cells to contact with UPM, the nasal epithelial cells, would respond similar to the tissue microenvironment, and the 3D respiratory mucosa model would be a suitable platform to capture these events. First, whole transcriptome analysis revealed that UPM induced gene expression alterations in inflammatory and adhesion-related genes in human nasal epithelial cells. Next, we developed an in vitro 3D respiratory mucosa model composed of human nasal epithelial cells, fibroblasts, and endothelial cells and demonstrated that the model is structurally and functionally compatible with the respiratory mucosa. Finally, we used our model to expose human nasal epithelial cells to UPM, which led to a disruption in the integrity of the respiratory mucosa by decreasing the expression of zonula occludens-1 in both the epithelium and endothelium, while also reducing vascular endothelial cadherin expression in the endothelium. Conclusions We demonstrate the potential of the 3D respiratory mucosa model as a valuable tool for the simultaneous evaluation of multicellular responses caused by external stimuli in the human respiratory mucosa. We believe that the evaluation strategy proposed in the study will move us toward a better understanding of the detailed molecular mechanisms associated with pathological changes in the human respiratory system.
WBP5 Expression Influences Prognosis and Treatment Response in Head and Neck Squamous Cell Carcinoma
Objectives: Head and neck squamous cell carcinoma (HNSCC) is characterized by complex genetic alterations. This study aimed to identify WBP5 as a promising therapeutic target and evaluate the effect of WBP5 expression on prognosis and treatment response in HNSCC. Methods: Publicly available datasets were comprehensively analyzed to investigate WBP5 expression through comprehensive bioinformatics analysis and functional validation. Results: WBP5 was particularly overexpressed in HNSCC, as analyzed through the Gene Expression Profiling Interactive Analysis version 2 (GEPIA2) database and validated using multiple Gene Expression Omnibus (GEO) datasets. Analysis with UALCAN confirmed that WBP5 expression was significantly higher in advanced cancer stages and tumor grades than that of normal samples. A Kaplan–Meier analysis demonstrated that patients overexpressing WBP5 had a poor prognosis. Moreover, WBP5 expression correlated with the overexpression of the epidermal growth factor receptor in HNSCC. In vitro experiments revealed that WBP5 knockdown significantly reduced FaDu cell proliferation and viability. Furthermore, silencing WBP5 enhanced cisplatin sensitivity, indicating its potential role in chemoresistance. Conclusions: These results indicate that WBP5 could act as a prognostic marker and a viable therapeutic target in HNSCC. Modulating WBP5 expression may represent a novel strategy to enhance treatment efficacy. Future studies should elucidate the precise mechanisms of WBP5 action and develop targeted therapies. This integrated approach, combining a comprehensive analysis of publicly available datasets with in vitro experimental validation provides strong evidence for the clinical significance of WBP5 in HNSCC.
Role of Matrix Metalloproteinases 7 in the Pathogenesis of Laryngopharyngeal Reflux: Decreased E-cadherin in Acid exposed Primary Human Pharyngeal Epithelial Cells
Cleavage of E-cadherin and the resultant weakness in the cell-cell links in the laryngeal epithelium lining is induced by exposure to acidic contents of the refluxate. Herein, we aimed to evaluate the role of matrix metalloproteinases (MMPs) in inducing E-cadherin level changes following acid exposure to the human pharyngeal mucosal cells. E-cadherin levels were inversely correlated with the duration of acid exposure. Treatment with actinonin, a broad MMP inhibitor, inhibited this change. Immunocytochemical staining and transepithelial permeability test revealed that the cell surface staining of E-cadherin decreased and transepithelial permeability increased after acid exposure, which was significantly inhibited by the MMP inhibitor. Among the various MMPs analyzed, the mRNA for MMP-7 in the cellular component was upregulated, and the secretion and enzymatic activity of MMP-7 in the culture media increased with the acid treatment. Consequently, MMP-7 plays a significant role in the degradation of E-cadherin after exposure to a relatively weak acidic condition that would be similar to the physiologic condition that occurs in Laryngopharyngeal reflux disease patients.
Objective Assessment of Postoperative Swallowing Difficulty Through Ultrasound in Patients Undergoing Thyroidectomy
Swallowing discomfort is a common postoperative complaint in patients undergoing thyroidectomy. Contraction of the strap muscles might cause resistance to elevation of the laryngotracheal unit, and downward movement of the laryngotracheal unit may lead to swallowing discomfort. However, few studies have evaluated the mechanism related to limited laryngotracheal elevation after thyroidectomy. We aimed to objectively verify the presence of postoperative impaired laryngotracheal elevation through ultrasound evaluation in patients undergoing thyroidectomy and evaluate its relationship with limitation of laryngotracheal elevation. This is a prospective clinical study. Among patients undergoing hemithyroidectomy and total thyroidectomy, the patients who were followed up for ≥ 6 months were selected (N = 40). Ultrasound evaluation was done preoperatively and at 1, 3, and 6 months postoperatively. Laryngotracheal movement was recorded and the length of elevation was measured. Symptom after thyroidectomy was evaluated through swallowing-related items of thyroidectomy-related voice questionnaire. Ultrasound evaluation verified the presence of limited laryngotracheal elevation postoperatively in patients undergoing thyroidectomy. After thyroidectomy, the swallowing-related score was significantly increased, and was recovered time-dependently at 1 month. Laryngotracheal elevation showed significant decrease after thyroidectomy. The symptom score of swallowing was significantly correlated with the length of laryngotracheal elevation. Post-thyroidectomy ultrasound evaluation verified that laryngotracheal elevation was significantly impaired. Presence of adhesion between the laryngotracheal unit and the superficial soft tissue was the probable cause of the limitation at 6 months after thyroidectomy. The length of laryngotracheal elevation was related to the symptom score of swallowing after thyroid surgery.
Non-surgical animal model of gastroesophageal reflux disease by overeating induced in mice
Previous animal models of gastroesophageal reflux disease (GERD) were not physiological and required a variety of surgical procedures. Therefore, the animal model developed by conditions that are similar to the pathogenesis of GERD is necessary. The aim is to establish a non-surgical animal model with GERD caused by overeating induced in mice. To induce mice to overeat, we designed dietary control protocols including repetitive fasting and feeding. The esophageal tissues were evaluated with GERD markers to prove the establishment of a GERD animal model. Mice fasted every other day (group 2) showed more pronounced overeating feature and demonstrated evident changes similar to the macroscopic and microscopic findings of GERD, the expressions of inducible nitric oxide synthase and substance P were stronger. The higher frequency of fasting and overeating could cause GERD effectively. The dietary control can make mice overeat, which elicits the change of lower esophageal mucosa similar to GERD. Thus, the overeating-induced mouse may be used as a GERD mouse model.
Collective pulsatile expansion and swirls in proliferating tumor tissue
Understanding the dynamics of expanding biological tissues is essential to a wide range of phenomena in morphogenesis, wound healing and tumor proliferation. Increasing evidence suggests that many of the relevant phenomena originate from complex collective dynamics, inherently nonlinear, of constituent cells that are physically active. Here, we investigate thin disk layers of proliferating, cohesive, monoclonal tumor cells and report the discovery of macroscopic, periodic, soliton-like mechanical waves with which cells are collectively ratcheting, as in the traveling-wave chemotaxis of dictyostelium discodium amoeba cells. The relevant length-scale of the waves is remarkably large (∼1 mm), compared to the thickness of a mono-layer tissue ( ∼ 10 m ). During the tissue expansion, the waves are found to repeat several times with a quite well defined period of approximately 4 h. Our analyses suggest that the waves are initiated by the leading edge that actively pulls the tissue in the outward direction, while the cells within the bulk tissue do not seem to generate a strong self-propulsion. Subsequently, we demonstrate that a simple mathematical model chain of nonlinear springs that are constantly pulled in the outward direction at the leading edge recapitulates the observed phenomena well. As the areal cell density becomes too high, the tissue expansion stalls and the periodic traveling waves yield to multiple swirling vortices. Cancer cells are known to possess a broad spectrum of migration mechanisms. Yet, our finding has established a new unusual mode of tumor tissue expansion, and it may be equally applicable for many different expanding thin layers of cell tissues.