Pepsin and Laryngeal and Hypopharyngeal Carcinomas

Correlation between serum levels of cyclooxygenase-2, aquaporin-1, pepsinogen I, gastrin-17 and pathological features of Laryngeal Cancer

Objective

To explore the association between the levels of cyclooxygenase-2 (COX-2), aquaporin-1 (AQP1), pepsinogen I (PGI), and gastrin-17 (G17) and pathological features of laryngeal cancer (LC).

Methods

Clinical data of 120 patients with LC, treated in Shanghai Jiao Tong University School of Medicine from May 2022 to May 2023, as well as 120 healthy individuals who underwent physical examinations during the same period, were retrospectively analyzed. Serum levels of COX-2, AQP1, PGI, and G17 of LC patients and the healthy cohort were compared, and their association with pathological features of LC was investigated.

Results

LC was associated with significantly higher serum levels of COX-2, AQP1, and G17 and lower of PGI compared to the control group (P<0.05). Levels of COX-2, AQP1, and G17 positively correlated with the tumor, node and metastasis (TNM) staging, infiltration depth, and the lymph node metastases, and negatively correlated with the degree of differentiation (P<0.05). There was a significant negative correlation between the level of PGI and TNM staging, infiltration depth, and lymph node metastases. PG1 also positively correlated with the degree of differentiation (P<0.05). Area under curve (AUC) of combined COX-2, AQP1, PG-I, and G17 was significantly higher than that of each index alone (P<0.05).

Conclusions

Levels of COX-2, AQP1, PGI, and G17 showed significant association with specific pathological features of LC. Serum levels of COX-2, AQP1, PGI, and G17 have certain predictive value for LC, and the combined predictive value of these four indicators is higher than that of a single indicator.

Global Transcriptomic Analysis of Topical Sodium Alginate Protection against Peptic Damage in an In Vitro Model of Treatment-Resistant Gastroesophageal Reflux Disease

Breakthrough symptoms are thought to occur in roughly half of all gastroesophageal reflux disease (GERD) patients despite maximal acid suppression (proton pump inhibitor, PPI) therapy. Topical alginates have recently been shown to enhance mucosal defense against acid-pepsin insult during GERD. We aimed to examine potential alginate protection of transcriptomic changes in a cell culture model of PPI-recalcitrant GERD. Immortalized normal-derived human esophageal epithelial cells underwent pretreatment with commercial alginate-based anti-reflux medications (Gaviscon Advance or Gaviscon Double Action), a matched-viscosity placebo control, or pH 7.4 buffer (sham) alone for 1 min, followed by exposure to pH 6.0 + pepsin or buffer alone for 3 min. RNA sequencing was conducted, and Ingenuity Pathway Analysis was performed with a false discovery rate of ≤0.01 and absolute fold-change of ≥1.3. Pepsin-acid exposure disrupted gene expressions associated with epithelial barrier function, chromatin structure, carcinogenesis, and inflammation. Alginate formulations demonstrated protection by mitigating these changes and promoting extracellular matrix repair, downregulating proto-oncogenes, and enhancing tumor suppressor expression. These data suggest molecular mechanisms by which alginates provide topical protection against injury during weakly acidic reflux and support a potential role for alginates in the prevention of GERD-related carcinogenesis.

Laryngopharyngeal Reflux Pathophysiology, Clinical Presentation, and Management: A Narrative Review

Laryngopharyngeal reflux (LPR) is a common and often misinterpreted clinical entity responsible for various symptoms affecting the upper aerodigestive tract. This narrative literature review aims to review the pathophysiology, symptoms, and management of LPR, emphasizing the emerging understanding of gastric content reflux in aerodigestive tissue irritation. Understanding the pathophysiology of LPR will allow general practitioners and specialists to accurately recognize and treat a condition that causes substantial morbidity in the affected patients. Using evidence-based findings from randomized controlled trials, clinical studies, and meta-analyses, the present investigation aims to outline and unify previous research into LPR. A review of anatomical structures, pathogenic mechanisms, endoscopic findings in LPR, and clinical manifestations and treatment options are also discussed. Though controversy around the diagnosis and management of LPR persists, emerging research in cellular damage and diagnostic tools promises to provide increasingly accurate and reliable modalities for characterizing LPR. Hopefully, future research will unify the field and provide overarching guidelines for both primary care and specialists. The present investigation provides an integrated perspective on LPR, a clinically prevalent and complex disease.

Pepsin Inhibitors Prevent Inflammation and Loss of Laryngeal Barrier Function in Mice with Gastroesophageal Reflux

OBJECTIVE

This study aimed to evaluate the role of pepsin inhibitors in the inflammatory response and their effects on laryngeal mucosal integrity during gastroesophageal reflux (GERD) under in vivo conditions.

METHODS

A surgical model of GERD was used, in which mice were treated with pepstatin (0.3 mg/kg) or darunavir (8.6 mg/kg) for 3 days. On the third day after the experimental protocol, the laryngeal samples were collected to assess the severity of inflammation (wet weight and myeloperoxidase activity) and mucosal integrity (transepithelial electrical resistance and paracellular epithelial permeability to fluorescein).

RESULTS

The surgical GERD model was reproduced. It showed features of inflammation and loss of barrier function in the laryngeal mucosa. Pepstatin and darunavir administration suppressed laryngeal inflammation and preserved laryngeal mucosal integrity.

CONCLUSION

Pepsin inhibition by the administration of pepstatin and darunavir improved inflammation and protected the laryngeal mucosa in a mouse experimental model of GERD.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:3080-3085, 2024.

Pepsin Increases the Proliferation of Vocal Cord Leukoplakia Epithelial Cells by Inducing Autophagy

OBJECTIVE

To investigate the role of H+ /K+ ATPase in the proliferation of pepsin-induced vocal cord leukoplakia (VCL) cells.

STUDY DESIGN

Translation research.

SETTING

Affiliated Hospital of University.

METHODS

Immunohistochemistry was used to detect pepsin, H+ /K+ ATPase (ATP4A and ATP4B subunits) in VCL cells with varying degrees of dysplasia. After primary cultures of VCL cells had been established, the effects of acidified pepsin on the proliferation, autophagy, and H+ /K+ -ATPase distribution of VCL cells were investigated.

RESULTS

The levels of pepsin, ATP4A, and ATP4B were significantly higher in VCL tissue with moderate-to-severe dysplasia than in normal tissue (p < .05); these levels gradually increased according to dysplasia severity. The expression levels of ATP4A and ATP4B were significantly correlated with the amount of pepsin in VCL cells (p < .01). Acidified pepsin enhanced the levels of proliferation and autophagy in human VCL epithelial cells. The cloning- and autophagy-promoting effects of acidified pepsin on VCL cells were partially reversed by pantoprazole; these effects were completely blocked by the autophagy inhibitor chloroquine. Finally, acidified pepsin promoted the colocalization of H+ /K+ -ATPase and lysosomes in VCL cells; it also mediated lysosome acidification.

CONCLUSION

Pepsin and H+ /K+ -ATPase may contribute to the progression of VCL. Specifically, acidified pepsin may regulate lysosome acidification by promoting lysosomal localization of H+ /K+ -ATPase.

3-Hydroxyflavone - bovine serum albumin complex used as fluorescent probe for the detection of pepsin

In this study, a method for the determination of pepsin using a 3-hydroxyflavone (3-HF)-bovine serum albumin (BSA) complex as a fluorescent probe was established. Under acidic conditions, 3-HF can react with BSA to emit strong green fluorescence, which involves an excited state intramolecular proton transfer and fluorescence resonance energy transfer. After pepsin is added, the fluorescence of the 3-HF-BSA system is quenched due to the hydrolysis of BSA. The degree of 3-HF-BSA fluorescence quenching has a good linear relationship with the concentration of pepsin in the range of 10-80 μg/mL. The correlation coefficient was R² = 0.9932 and the detection limit was 2.41 μg/mL. This method has high selectivity and good stability and has been used to determine pepsin in real samples with satisfactory results.

Comparative study of the binding between chlorogenic acid and four proteins by isothermal titration calorimetry, spectroscopy and docking methods

As a polyphenolic compound, chlorogenic acid has antioxidant, anti-inflammatory, antiviral, anti-obesity and other effects. Based on the interactions between chlorogenic acid and the proteins (human serum albumin (HSA), pepsin (Pep), trypsin (Try), fat mass and obesity-associated protein (FTO)), results will provide clues for screening effective inhibitors. The interaction between chlorogenic acid and the four proteins (HSA, Pep, Try, FTO) was analyzed by the aid of fluorescence quenching, synchronous fluorescence, three-dimensional fluorescence, isothermal titration calorimetry, and molecular docking. It can be concluded that there is no obvious interaction between chlorogenic acid and FTO. The binding affinity between chlorogenic acid and three proteins is HSA > Try > Pep. The binding process is spontaneous, and the quenching type is static quenching. Hydrophobic interaction and hydrogen bonding is observed in the binding process. This study provides valuable information for understanding the interaction mechanism between chlorogenic acid and proteins, and provides clues for screening inhibitors.

The role of Glut-1 and H+/K+-ATPase expression in hyperplasia of mice laryngeal epithelium induced by pepsin

Purpose

To explore the role played by Glut-1 and H⁺/K⁺-ATPase in pepsin-induced, mouse laryngeal epithelial proliferation, growth, and development.

Methods

We established a mouse model of laryngopharyngeal reflux and measured Glut-1 and H⁺/K⁺-ATPase expression levels in mouse laryngeal epithelium treated with artificial gastric juice containing pepsin.

Results

Artificial pepsin-containing gastric juice induced significant hyperplastic changes in mouse laryngeal epithelium compared to control mice at 15, 30, and 45 days. Inhibition of Glut-1 expression by 2-DG significantly suppressed such hyperplasia compared to mice exposed to artificial gastric juice containing pepsin at 15, 30, and 45 days. After treatment with pepsin-containing artificial gastric juice, RT-PCR and Western blotting showed that the levels of Glut-1 and H⁺/K⁺-ATPase α, β increased significantly.

Conclusions

Pepsin-containing artificial gastric juice promoted mouse laryngeal epithelial hyperplasia associated with abnormal expression of Glut-1 and H⁺/K⁺-ATPase α, β.

Effects of acids, pepsin, bile acids, and trypsin on laryngopharyngeal reflux diseases: physiopathology and therapeutic targets

PURPOSE

Laryngopharyngeal reflux disease (LPRD) is a general term for the reflux of gastroduodenal contents into the laryngopharynx, oropharynx and even the nasopharynx, causing a series of symptoms and signs. Currently, little is known regarding the physiopathology of LPRD, and proton pump inhibitors (PPIs) are the drugs of choice for treatment. Although acid reflux plays a critical role in LPRD, PPIs fail to relieve symptoms in up to 40% of patients with LPRD. The influence of other reflux substances on LPRD, including pepsin, bile acid, and trypsin, has received increasing attention. Clarification of the substances involved in LPRD is the basis for LPRD treatment.

METHODS

A review of the effects of acids, pepsin, bile acids, and trypsin on laryngopharyngeal reflux diseases was conducted in PubMed.

RESULTS

Different reflux substances have different effects on LPRD, which will cause various symptoms, inflammatory diseases and neoplastic diseases of the laryngopharynx. For LPRD caused by different reflux substances, 24-h multichannel intraluminal impedance combined with pH-metry (MII-pH), salivary pepsin, bile acid and other tests should be established so that different drugs and treatment courses can be used to provide patients with more personalized treatment plans.

CONCLUSION

This article summarizes the research progress of different reflux substances on the pathogenesis, detection index and treatment of LPRD and lays a theoretical foundation to develop target drugs and clinical diagnosis and treatment.

Role and mechanism of Glut-1 and H+/K+-ATPase expression in pepsin-induced development of vocal cord leukoplakia

PURPOSE

We investigated the role of Glut-1 and H⁺/K⁺-ATPase expression in pepsin-induced development of human vocal cord leukoplakia cells (HVCLCs). Next, we analyzed the relationship between Glut-1 and H⁺/K⁺-ATPase expression with the clinicopathological features of laryngeal carcinoma.

METHODS

Glut-1 and H⁺/K⁺-ATPase expression levels in HVCLCs were determined after treatment with artificial gastric juice containing pepsin and laryngeal carcinoma tissues.

RESULTS

Exposure to pepsin-containing artificial gastric juice significantly enhanced the migration and proliferation of VSCLCs in a time-dependent manner. The apoptotic rate of VSCLCs decreased over time after exposure to pepsin and reached a nadir on day 7 (p < 0.01). With increasing duration of exposure to pepsin, the proportion of VSCLCs in G0/G1 phase decreased and the proportions in the S and G2/M phases significantly increased (p < 0.05). After treatment with pepsin-containing artificial gastric juice, RT-PCR and Western blotting showed that the expression of Glut-1 and H⁺/K⁺-ATPase α, β significantly increased in HVCLCs compared to in the absence of pepsin (p < 0.05). The expression of Glut-1 and H⁺/K⁺-ATPase α, β gradually increased from vocal cord leukoplakia (VLC) to laryngeal carcinoma (p < 0.05). Lentivirus-mediated inhibition of Glut-1 expression in VCL significantly inhibited the cells' migration and proliferation (p < 0.05) but enhanced their apoptosis (p < 0.05). Also, inhibition of Glut-1 expression resulted in an increased proportion of cells in G0/G1 phase and a significantly decreased proportion in G2/M phase (p < 0.05).

CONCLUSIONS

Elevated Glut-1 expression may promote the development of VCL by upregulating laryngeal H⁺/K⁺-ATPase expression to reactivate absorbed pepsin, thus damaging the laryngeal mucosa.

The Association between Free Sugars Consumption and Laryngopharyngeal Reflux: A Cross-Sectional Study among Chinese Adolescents

There is a lack of evidence to show prevalence of laryngopharyngeal reflux (LPR) and the association between LPR and dietary factors. Adolescents consume the most amount of free sugars among the Chinese population. We conducted this study to investigate the prevalence of LPR in Chinese adolescents and explore the association between free sugars consumption and LPR. A cross-sectional study was conducted on 1517 middle school students in Hunan, China. An online questionnaire was applied to collect data on the condition of LPR, consumption of free sugars and other self-reported covariates. Height, weight and waist circumference were collected by anthropometric measurements. Logistic regression was applied to assess the association between LPR and free sugars consumption. The mean and standard deviation of free sugars consumption was 53.14 ± 44.75 (g/d). The prevalence of LPR was 8.11%. A positive association was observed between LPR and higher free sugars consumption after adjusted multiple covariates, with adjusted odds ratio (95% confident interval) of 1.656 (1.125–2.438). The prevalence of LPR among Chinese adolescents was high. Further analytic studies with strict design are required to test the association between LPR and free sugar consumption. Systematic strategies and policies should to be developed to reduce the intake of free sugars in order to prevent LPR.