MUC5AC Research Articles

Bioactive fraction of Musa balbisiana seed mitigates D-galactose-induced brain aging via SIRT1/PGC-1α/FoxO3a activation and intestinal barrier dysfunction by modulating gut microbiota and core metabolites

Aging is an inevitable biological process, and emerging research has highlighted the potential of dietary and pharmacological interventions to decelerate the trajectory of age-related diseases and prolong the health span. This study evaluates the protective effects of Musa balbisiana seed on healthy aging using D-galactose-induced accelerated aging rats. The results suggested that the bioactive ethyl acetate fraction of Musa balbisiana seed extract (BF) exhibited protective effects against aging-induced oxidative stress by reducing oxidative DNA damage, advanced glycation end-product formation, and malondialdehyde levels while restoring antioxidant and glyoxalase enzyme activities. BF also ameliorated neurodegeneration by decreasing acetylcholinesterase enzyme activity and amyloid beta plaque formation. Histopathological analysis demonstrated the protective effects of BF against brain aging, liver disruption, renal damage, and intestinal barrier dysfunction. BF further restored intestinal permeability by upregulating the tight junctions (zonula occludens 1 and 2, claudin 1,2,3 and 4, and occludin) and mucin (mucin 2 and mucin 5ac) gene expression while downregulating the expression of inflammatory cytokines (IL-1β, IL-6, and TNF-α). BF significantly induced the phosphorylation of FoxO3a proteins and upregulated the gene expression of SIRT1, PGC-1α, and TFAM in the hippocampus. Next-generation sequencing (NGS) of 16s rRNA amplicons of fecal metagenomics DNA and metabolites profiling showed that BF intervention restructured the gut microbiota and altered core metabolites related to cholesterol metabolism. Overall, our findings demonstrated the multifaceted protective effects of Musa balbisiana seed against D-galactose-induced aging.

Targeting TMEM16A ion channels suppresses airway hyperreactivity, inflammation, and remodeling in an experimental Guinea pig asthma model

Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness, inflammation, and remodeling. Calcium (Ca2+)-activated chloride (Cl−) channels, such as TMEM16A, are inferred to be involved in asthma. Therefore, the present study investigated the therapeutic potential of TMEM16A inhibition in a guinea pig model of ovalbumin (OVA)-induced allergic asthma. Guinea pigs were treated with a specific blocker, CaCCinh-A01 (10 μM), administered via inhalation. A significant reduction in cough reflex sensitivity and specific airway resistance was observed in animals treated with CaCCinh-A01, highlighting its potential to improve airway function. Despite a reduction in ciliary beating frequency (CBF), CaCCinh-A01 reduced airway mucus viscosity by decreasing the production of mucin-5AC (MUC5AC). The nonspecific reduction in the Th1/Th2 cytokine spectrum following CaCCinh-A01 treatment indicated the suppression of airway inflammation. Additionally, markers associated with airway remodeling were diminished, suggesting that CaCCinh-A01 may counteract structural changes in airway tissues. Therefore, inhibition appears to mitigate the pathological aspects of asthma, including airway hyperresponsiveness, inflammation, and remodeling. However, further studies are required to comprehensively evaluate the potential of TMEM16A as a therapeutic target for asthma.

Tangeretin inhibits airway inflammatory responses by reducing early growth response 1 (EGR1) expression in mice exposed to cigarette smoke and lipopolysaccharide

BackgroundTangeretin, a natural polymethoxyflavone compound, possesses potent anti-inflammatory activity that improves respiratory inflammation in chronic obstructive pulmonary disease (COPD). However, the molecular mechanisms underlying the anti-COPD effects of tangeretin remain unclear. In this study, we aimed to investigate the key molecular mechanisms by which tangeretin suppresses COPD-related inflammatory responses. MethodsWe conducted the investigation in phorbol-12-myristate-13-acetate (PMA)-stimulated human airway epithelial cells (in vitro) and cigarette smoke (CS)/lipopolysaccharide (LPS)-exposed mice (in vivo). ResultsTangeretin decreased the release of inflammatory mediators, including tumor necrosis factor-α (TNF-α), interleukin 6 (IL-6), and mucin 5AC (MUC5AC), by suppressing early growth response 1 (EGR1) expression in vitro. Tangeretin and EGR1 small interfering ribonucleic acid (siRNA) combination showed a synergistic reduction in MUC5AC and TNF-α secretion. Tangeretin administration significantly inhibited the levels of reactive oxygen species (ROS) production, elastase activity, TNF-α, IL-6, and monocyte chemoattractant protein-1 (MCP-1) secretion, and macrophage and neutrophil numbers in the bronchoalveolar lavage fluid of CS/LPS-exposed mice. Tangeretin also prevented CS/LPS-induced abnormal pathological changes and excessive MUC5AC and EGR1 expression in lung tissue. ConclusionComprehensively, tangeretin inhibits the lung inflammatory response associated with COPD by reducing EGR1 expression in PMA-induced human epithelial cells and in a CS/LPS-stimulated mouse model. This study shows that tangeretin has anti-COPD properties and can be a promising alternative (or complementary) treatment for inflammatory lung disease.

Investigating the binding affinity, molecular dynamics, and ADMET properties of curcumin-IONPs as a mucoadhesive bioavailable oral treatment for iron deficiency anemia

Iron deficiency anemia (IDA) is a common health issue, and researchers are interested in overcoming it. Nanotechnology green synthesis is one of the recent approaches to making efficient drugs. In this study, we modeled curcumin-coated iron oxide nanoparticles (cur-IONPs) to study their predicted toxicity and drug-likeness properties, then to investigate mucoadhesive behavior by docking cur-IONPs with two main mucin proteins in gastrointestinal tract (GIT) mucosa (muc 5AC and muc 2). Furthermore, the stability of cur-IONPs/protein complexes was assessed by molecular dynamics. Our in-silico studies results showed that cur-IONPs were predicted to be potential candidates to treat IDA due to its mucoadhesive properties, which could enhance the bioavailability, time residency, and iron absorbance through GIT, in addition to its high safety profile with high drug-likeness properties and oral bioavailability. Finally, molecular dynamic simulation studies revealed stable complexes supporting strength docking studies. Our results focus on the high importance of in-silico drug design studies; however, they need to be supported with in vitro and in vivo studies to reveal the efficacy, toxicity, and bioavailability of cur-IONPs.

PM2.5 Exposure Aggravates Inflammatory Response and Mucus Production in 16HBE Cells through Inducing Oxidative Stress and RAGE Expression.

Particulate matter 2.5 (PM2.5)-induced oxidative stress has been extensively proposed as a pivotal event in lung diseases. Receptor for advanced glycation end-products (RAGE) is a receptor of pro-inflammatory ligands that has been supported to be implied in the progression of multiple lung diseases. This study attempts to delineate the specific effects of PM2.5 on human bronchial epithelial 16HBE cells in vitro and figure out whether PM2.5 functions via mediating oxidative stress and RAGE. In PM2.5-challenged 16HBE cells, MTT assay detected cell viability. ELISA estimated inflammatory levels. Flow cytometry analysis measured ROS activity and related assay kits examined oxidative stress levels. Western blot tested nuclear factor E2-related factor 2 (Nrf2), RAGE, β-catenin, and mucin 5AC (MUC5AC) expression. Immunofluorescence staining evaluated nuclear translocation of β-catenin. It was noticed that PM2.5 exposure exacerbated inflammatory response, oxidative stress, and mucus production. Additionally, PM2.5 elevated RAGE expression while declined Nrf2 expression as well as stimulated the nuclear translocation of β-catenin. Furthermore, RAGE inhibition or nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor VAS2870 mitigated inflammatory response, oxidative stress, and mucus generation in PM2.5-exposed 16HBE cells. In addition, RAGE inhibition or VAS2870 raised Nrf2 expression, reduced RAGE expression, and hampered β-catenin nuclear translocation. Briefly, PM2.5 might act as a leading driver of inflammatory response and mucus production in lung injury, the mechanism of which might be related to the activation of oxidative stress and the up-regulation of RAGE.

Abstract A015: Tissue MUC5AC expression predicts recurrence patterns following resection in pancreatic ductal adenocarcinoma

Abstract Pancreatic ductal adenocarcinoma (PDA) has consistently poor outcomes, even for early-stage tumors that undergo resection (>70%), despite completion of prescribed perioperative systemic therapy. Mucin 5AC (MUC5AC), a heavy glycoprotein, exists in two major glycoforms: heavily glycosylated mature (MM) and less glycosylated immature (IM) forms. MM is located in the apical region and extracellular space, whereas IM is in the perinuclear region. Our previous work demonstrated the association between MM and treatment response and outcomes in resected PDA after neoadjuvant therapy (NAT). In this study, we investigate the impact of MUC5AC tissue expression in resected PDA samples on recurrence site characteristics (local (LR) vs. distant metastasis (mets) vs. both LR and mets). Resected PDA formalin-fixed paraffin-embedded tissue blocks from January 2010 to June 2021 were obtained from the Ohio State University biorepository. Immunohistochemistry was performed to study the expression for MM and IM using monoclonal antibodies 45M1 and CLH2, respectively, and H-scores (0-300) were calculated. Logistic regression was used to study this association of interest. We had 100 R-PDA (43 received NAT, and 57 had upfront surgery (UpS)) available for testing. The median age of diagnosis was 65 years, and 50% were males. Most of the patients in the NAT group received FOLFIRINOX (n=36) and received gemcitabine/nab-paclitaxel (n=5) or FOLFOX (n=2). The median number of doses received is 6 (range 2-9). The results in these groups can be summarized as follows: a) 35/43 had recurrence (LR=7, mets=21, and LR+mets=7), with the liver being the most common site of metastasis (13/28) followed by lung (5/28) and peritoneum (5/28), b) Higher IM expression (mean H-score) was significantly (p=0.0275) higher in LR+mets (H-score 196) than in LR (H-score 69) or mets (H-score 115) groups, c) Higher MM expression (mean H-score) was also significantly different among these groups (LR vs. mets vs. LR+mets = 81 vs. 120 vs. 206, p= 0.0358), e) similar trend of mean H-scores was noted in FOLFIRINOX sub-group (LR vs. mets vs. LR+mets = 205 vs. 109 vs. 60, p=0.0185 for IM and 65 vs. 116 vs. 205, p=0.0329 for MM). No significant association between recurrence patterns and tissue MUC5AC expression in the UpS group. These findings concur with our prior observations, underscoring the clinical significance of MUC5AC in resected PDA post-NAT and suggesting its potential role in facilitating pancreatic tumor cell metastasis. Although larger prospective studies are needed to confirm these results, our study highlights MUC5AC as a potential therapeutic target to prevent metastasis in early-stage PDA, potentially improving overall outcomes. Citation Format: Ashish Manne, Lianbo Yu, Ashwini Esnakula. Tissue MUC5AC expression predicts recurrence patterns following resection in pancreatic ductal adenocarcinoma [abstract]. In: Proceedings of the AACR Special Conference in Cancer Research: Advances in Pancreatic Cancer Research; 2024 Sep 15-18; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2024;84(17 Suppl_2):Abstract nr A015.

Mature MUC5AC Expression in Resected Pancreatic Ductal Adenocarcinoma Predicts Treatment Response and Outcomes.

Neoadjuvant therapy (NAT) for early-stage pancreatic ductal adenocarcinoma (PDA) has recently gained prominence. We investigated the clinical significance of mucin 5 AC (MUC5AC), which exists in two major glycoforms, a less-glycosylated immature isoform (IM) and a heavily glycosylated mature isoform (MM), as a biomarker in resected PDA. Immunohistochemistry was performed on 100 resected PDAs to evaluate the expression of the IM and MM of MUC5AC using their respective monoclonal antibodies, CLH2 (NBP2-44455) and 45M1 (ab3649). MUC5AC localization (cytoplasmic, apical, and extra-cellular (EC)) was determined, and the H-scores were calculated. Univariate and multivariate (MVA) Cox regression models were used to estimate progression-free survival (PFS) and overall survival (OS). Of 100 resected PDA patients, 43 received NAT, and 57 were treatment-naïve with upfront surgery (UpS). In the study population (n = 100), IM expression (H-scores for objective response vs. no response vs. UpS = 104 vs. 152 vs. 163, p = 0.01) and MM-MUC5AC detection rates (56% vs. 63% vs. 82%, p = 0.02) were significantly different. In the NAT group, MM-MUC5AC-negative patients had significantly better PFS according to the MVA (Hazard Ratio: 0.2, 95% CI: 0.059-0.766, p = 0.01). Similar results were noted in a FOLFIRINOX sub-group (n = 36). We established an association of MUC5AC expression with treatment response and outcomes.

Effects of Benzo[α]pyrene on Mucus Secretion and Tissue Remodeling in a Rat Model of Allergic Rhinitis.

Exposure to benzo[α]pyrene (BaP) increases the incidence and severity of allergic rhinitis (AR), but the underlying mechanisms remain unclear. Thus, we investigated the in vivo effects of BaP exposure on mucus hypersecretion and tissue remodeling in a rat model of AR. Female Sprague-Dawley rats were randomly divided into 4 groups: a negative control group, a group of healthy rats exposed to BaP, a group of rats with ovalbumin (OVA)-induced AR, and a group of AR model rats exposed to BaP. Nasal symptoms and levels of OVA-specific serum immunoglobulin E (IgE) were measured in each individual rat. Moreover, examination of goblet cell hyperplasia and collagen deposition was carried out with periodic acid-Schiff (PAS) staining and Masson trichrome (MT) staining. Mucin 5AC (MUC5AC) expression was assessed by immunohistochemistry. BaP significantly increased the number of sneezes, the number of nasal rubs and the levels of OVA-specific serum IgE in rats with AR. Statistically significant differences in goblet cell hyperplasia and collagen deposition were observed between the BaP-exposed AR model group and the AR model group. Immunohistochemical results showed that the nasal mucosa of AR model rats displayed markedly elevated MUC5AC expression after BaP exposure. Our data indicate that mucus hypersecretion and the development of nasal remodeling might be pathophysiologic mechanisms underlying increased susceptibility to AR after exposure to BaP.

In mouse model of mixed granulocytic asthma with corticosteroid refractoriness, Bronchom mitigates airway hyperresponsiveness, inflammation and airway remodeling

BackgroundAsthma is a heterogeneous, inflammatory disease with several phenotypes and endotypes. Severe asthmatics often exhibit mixed granulocytosis with reduced corticosteroid sensitivity. Bronchom is a newly developed Ayurvedic prescription medicine, indicated for the treatment of obstructive airway disorders. The purpose of the present study was to evaluate the in-vivo efficacy of Bronchom in mouse model of mixed granulocytic asthma with steroidal recalcitrance.MethodsHigh-performance thin layer chromatography (HPTLC) and Ultra-high performance liquid chromatography (UHPLC) were employed to identify and quantitate the phytometabolites present in Bronchom. The preclinical effectiveness of Bronchom was assessed in house dust mite (HDM) and Complete Freund’s adjuvant (CFA)-induced mixed granulocytic asthma model in mice. High dose of dexamethasone was tested parallelly. Specific-pathogen-free C57BL/6 mice were immunized with HDM and CFA and nineteen days later, they were intranasally challenged with HDM for four consecutive days. Then the mice were challenged with nebulized methacholine to evaluate airway hyperresponsiveness (AHR). Inflammatory cell influx was enumerated in the bronchoalveolar lavage fluid (BALF) followed by lung histology. Additionally, the concentrations of Th2 and pro-inflammatory cytokines was assessed in the BALF by multiplexed immune assay. The mRNA expression of pro-inflammatory cytokines and Mucin 5AC (MUC5AC) was also evaluated in the lung.ResultsHPTLC fingerprinting and UHPLC quantification of Bronchom revealed the presence of bioactive phytometabolites, namely, rosmarinic acid, gallic acid, methyl gallate, piperine, eugenol and glycyrrhizin. Bronchom effectively reduced AHR driven by HDM-CFA and the influx of total leukocytes, eosinophils and neutrophils in the BALF. In addition, Bronchom inhibited the infiltration of inflammatory cells in the lung as well as goblet cell metaplasia. Further, it also suppressed the elevated levels of Th2 cytokines and pro-inflammatory cytokines in the BALF. Similarly, Bronchom also regulated the mRNA expression of pro-inflammatory cytokines as well as MUC5AC in mice lungs. Reduced effectiveness of a high dose of the steroid, dexamethasone was observed in the model.ConclusionsWe have demonstrated for the first time the robust pharmacological effects of an herbo-mineral medicine in an animal model of mixed granulocytic asthma induced by HDM and CFA. The outcomes suggest the potential utility of Bronchom in severe asthmatics with a mixed granulocytic phenotype.

Clinical ocular surface characteristics and expression of MUC5AC in diabetics: a population-based study.

To investigate the clinical characteristics and the expression of mucin 5AC (MUC5AC) in in diabetic and non-diabetic subjects with or without dry eye disease. A total of 399 participants (796 eyes) aged 50-80 years were enrolled in this study. Participants were divided into 4 groups: non-diabetic without dry eye group (normal group), non-diabetic with dry eye group, diabetic without dry eye group and diabetic with dry eye group. Demographic information, fasting plasma glucose (FBG), and glycated haemoglobin A1C (HbA1C) data were collected. Additionally, ocular surface disease index (OSDI) questionnaire, signs of dry eye, tear osmolarity, and meibomian glands were evaluated. Tear MUC5AC expression and conjunctival goblet cells density (GCD) were tested. Compared with non-diabetic with dry eye group, diabetic with dry eye group showed significantly lower tear film osmolarity (TFO), but higher corneal fluorescein and conjunctival lissamine green staining scores. In comparison with diabetic without dry eye group, diabetic with dry eye group showed significantly higher TFO, corneal fluorescein and conjunctival lissamine green staining scorers. The MUC5AC concentration and GCD of diabetic with dry eye group was significantly lower than those of the non-diabetic with dry eye group. Diabetic subjects with higher HbA1c levels (≥7.8%) showed higher TFO and shorter fluorescein tear break time. Diabetics with dry eye exhibited notably higher corneal fluorescein and conjunctival lissamine green staining scores. Conjunctival goblet cells and MUC5AC were significantly reduced in diabetics. Higher TFO was associated with the duration of diabetes and HbA1c levels.

Polysaccharides, the active component of Dendrobiumofficinale flower, ameliorates chronic pharyngitis in rats via TLR4/NF-κb pathway regulation

Ethnopharmacological relevanceChronic pharyngitis persistently afflicts a large population and accounts for approximately one-third of otolaryngology patients. Currently, the treatment of CP remains controversial because of the poor outcomes. Dendrobium officinale is a well-used “Yin-nourishing” traditional Chinese medicinal and edible herb used for thousands of years in China. The flowers of D. officinale are often used in folk of China to make tea for voice protection on and throat clearing. Aim of the studyThis study was to evaluate beneficial effects of polysaccharides from D. officinale flower (DOFP) on CP and its potential mechanisms. MethodsChemical characterization of DOFP, including polysaccharide content and monosaccharide composition, structural characterization using Fourier transform infrared spectroscopy were performed. A CP model was established in rats by administering a mixture of Chinese Baijiu and chili pepper liquid, combined with low-concentration ammonia spraying. The general states, amount of oral secretion, and apparent state of the pharynx of CP rats were observed during the period of DOFP administration. Furthermore, hemorheological parameters were measured using an automatic hematology analyzer. The levels of tumor necrosis factor-α (TNF-α), interleukin 1β (1L-1β), lipopolysaccharide (LPS), and D-lactate (D-LA) in the serum were measured by enzyme-linked immunosorbent assay. Morphological changes in the pharynx and colon were observed by hematoxylin-eosin staining. The expression of nuclear factor-κB p65 (NF-κB p65), p-NF-κB p65, cyclooxygenase-2 (COX-2), interleukin 1β（IL-1β）and mucin 5AC (MUC5AC) in the pharynx,Claudin-1, Occludin, and interleukin 6 (IL-6) in the colon was detected by immunohistochemistry and Western Blot. The mRNA expression of TLR4, COX-2, and IL-1β in the pharynx were determined using reverse transcription quantitative real-time PCR. ResultsIn this study, DOFP with a total polysaccharide content of 71.44% and a composition of D-mannose, galacturonic acid, glucose, galactose, and arabinose in a molar ratio of 3.95:2.19:1.00:0.74:1.30, was isolated from the flowers of D. officinale. DOFP improved the general state and exhibited significant effects on reducing oral secretion, alleviating pharyngeal injury, suppressing inflammatory cell infiltration in the pharynx, decreasing the serum levels of TNF-α and IL-1β, and reducing the number of white blood cells and lymphocytes in the model rats. Moreover, the expressions of TLR4, p-NF-κB p65, COX-2, IL-1β and MUC5AC in the pharynx of model rats were obviously inhibited. In addition, the levels of LPS, D-LA in the serum and the protein expression of IL-6 in the colon were downregulated when the protein expression of Occludin and Claudin-1 in the colon were upregulated. ConclusionsDOFP exerts significant ameliorating effects on CP and it likely acts by inhibiting LPS/TLR4-associated inflammatory mediator activation and reducing excessive secretion of mucus by repairing the intestinal barrier in CP rats.

Analysis of naproxen activation of cell death pathways in Colo320 cells.

Colorectal cancer is a life-threatening and prevalent type of cancer. However, a number of current treatments have serious side effects, which increase the need for alternatives. Non-steroidal anti-inflammatory drugs have potential chemopreventive capabilities. The present study aimed to confirm this, as well as to investigate potential pathways and reasons for this trait. To accomplish this, cancerous Colo320 and healthy CCD-18 cells were treated with various concentrations of naproxen sodium (NS). A caspase-3 assay revealed a statistically significant increase in caspase-3 activity in Colo320 cells (300%; P<0.01), but not in CCD-18 cells. This chemical was also associated with a significant decrease in Colo320 cell survival (-72.888%; P<0.01), but not CCD-18 cell survival. Furthermore, NS was found to significantly decrease the migration of Colo320 cells (86.58%; P<0.01). Finally, RNA sequencing of cells treated with NS revealed the statistically significant downregulation of the mucin 5B, oligomeric mucus/gel-forming, S100 calcium binding protein A9 and mucin 5AC, oligomeric mucus/gel-forming genes, which are upregulated in colorectal cancer and are known to contribute to cancer proliferation, stemness and drug resistance. These novel biological pathway results were further confirmed using ELISAs. The present study identified a novel molecular mechanism of the anti-colorectal cancer activity of NS.

Sivelestat sodium inhibits neutrophil elastase to regulate intrahepatic biliary mucin 5AC expression

To explore whether sivelestat sodium could reduce the expression of mucin 5AC (MUC5AC) in intrahepatic bile duct epithelial cells by inhibiting neutrophil elastase (NE) and thus provide new potential therapeutic ideas for the treatment of intrahepatic bile duct stone (IBDS). (1) Bioinformatics analysis: differential gene analysis was performed on gallbladder stone cholecystitis sequencing data based on the gene expression omnibus (GEO) to screen for significantly different genes related to neutrophils and mucins. The search tool for the retrieval of interacting genes database (STRING) was used for protein interaction analysis to predict whether there was an interaction between NE and MUC5AC genes. (2) Animal experiment: a total of 18 male SD rats were divided into the sham-operated group, cholangitis model group and sivelestat sodium treatment group according to the random number table method, with 6 rats in each group. The cholangitis rat model was established by a one-time injection of 1.25 mg/kg lipopolysaccharide (LPS) into the right anterior lobe of the liver of rats in combination with the pre-experiment; the liver of the sham-operated group was injected with an equal volume of saline. After the modelling, 100 mg/kg of sivelestat sodium was injected into the tail vein of the cevalexin treatment group once a day for 5 days, and an equal volume of saline was injected into the tail vein of the sham-operated group and the cholangitis model group. Two weeks later, the rats were euthanized and their liver and bile duct tissues were taken. The pathological changes in the liver and bile duct tissues were observed under the light microscope. Immunohistochemical staining was used to detect the expressions of NE and MUC5AC in liver and bile duct tissues. The protein expressions of NE, MUC5AC and Toll-like receptor 4 (TLR4) were detected by Western blotting. (3) Cell experiment: primary human intrahepatic biliary epithelial cell line (HiBEpiC) was divided into blank control group, NE group (10 nmol/L NE), NE+sivelestat sodium low dose group (10 nmol/L NE+1×10-8 g/L sivelestat sodium 1 mL), NE+sivelestat sodium medium dose group (10 nmol/L NE+1×10-7 g/L sivelestat sodium 1 mL), NE+sivelestat sodium high dose group (10 nmol/L NE+1×10-6 g/L sivelestat sodium 1 mL). Cells were collected after 48 hours of culture, and EdU was performed to detect the proliferative activity of cells; enzyme linked immunosorbent assay (ELISA) and Western blotting were performed to detect the expression of MUC5AC in cells. (1) Bioinformatics analysis: the NE gene (ELANE) had a reciprocal relationship with MUC5AC. (2) Animal experiment: light microscopy showed that hepatocyte edema, hepatocyte diffuse point and focal necrosis, confluent area fibrous tissue and intrahepatic bile ducts hyperplasia and inflammatory cell infiltration in the cholangitis model group; hepatic lobule structure of sivelestat sodium treatment group was clear, and the degree of peripheral inflammatory cell infiltration was reduced compared with the cholangitis model group. Immunohistochemical staining showed that the expressions of NE and MUC5AC were increased in the cholangitis model group compared with the sham-operated group, and the expressions of NE and MUC5AC were decreased in the sivelestat sodium group compared with the cholangitis model group [NE (A value): 5.23±2.02 vs. 116.67±23.06, MUC5AC (A value): 5.40±3.09 vs. 23.81±7.09, both P < 0.05]. Western blotting showed that the protein expressions of NE, MUC5AC, and TLR4 in the hepatic biliary tissues of the cholangitis model group were significantly higher than those of the sham-operated group; and the protein expressions of NE, MUC5AC, and TLR4 in the liver biliary tissues of the sivelestat sodium treatment group were significantly higher than those of the sham-operated group (NE/β-actin: 0.38±0.04 vs. 0.70±0.10, MUC5AC/β-actin: 0.37±0.03 vs. 0.61±0.05, TLR4/β-actin: 0.39±0.10 vs. 0.93±0.15, all P < 0.05). (3) Cell experiment: fluorescence microscopy showed that the proliferation of HiBEpiC cells in each group was good, and there was no significant difference in the proportion of positive cells. ELISA and Western blotting showed that the expressions of MUC5AC in cells of the NE group were significantly higher than those of the blank control group. The expressions of MUC5AC in the NE+different dose of sivelestat sodium group were significantly lower than those in the NE group, and showed a decreasing trend with the increase of sevastatin sodium concentration, especially in the highest dose group [MUC5AC (μg/L): 3.46±0.20 vs. 6.33±0.52, MUC5AC/β-actin: 0.45±0.07 vs. 1.75±0.10, both P < 0.05]. LPS can upregulate the expression of NE and MUC5AC in rats with cholangitis, while sodium sivelestat can reduce the expression of MUC5AC in in intrahepatic biliary epithelial cells by inhibiting NE, providing a new direction for the treatment of IBDS.

Dissecting the MUC5AC/ANXA2 signaling axis: implications for brain metastasis in lung adenocarcinoma

Non-small cell lung carcinoma (NSCLC) exhibits a heightened propensity for brain metastasis, posing a significant clinical challenge. Mucin 5ac (MUC5AC) plays a pivotal role in the development of lung adenocarcinoma (LUAD); however, its role in causing brain metastases remains unknown. In this study, we aimed to investigate the contribution of MUC5AC to brain metastasis in patients with LUAD utilizing various brain metastasis models. Our findings revealed a substantial increase in the MUC5AC level in LUAD brain metastases (LUAD-BrM) samples and brain-tropic cell lines compared to primary samples or parental control cell lines. Intriguingly, depletion of MUC5AC in brain-tropic cells led to significant reductions in intracranial metastasis and tumor growth, and improved survival following intracardiac injection, in contrast to the observations in the control groups. Proteomic analysis revealed that mechanistically, MUC5AC depletion resulted in decreased expression of metastasis-associated molecules. There were increases in epithelial-to-mesenchymal transition, tumor invasiveness, and metastasis phenotypes in tumors with high MUC5AC expression. Furthermore, immunoprecipitation and proteomic analysis revealed a novel interaction of MUC5AC with Annexin A2 (ANXA2), which activated downstream matrix metalloproteases and facilitated extracellular matrix degradation to promote metastasis. Disrupting MUC5AC-ANXA2 signaling with a peptide inhibitor effectively abrogated the metastatic process. Additionally, treatment of tumor cells with an astrocyte-conditioned medium or the chemokine CCL2 resulted in upregulation of MUC5AC expression and enhanced brain colonization. In summary, our study demonstrates that the MUC5AC/ANXA2 signaling axis promotes brain metastasis, suggesting a potential therapeutic paradigm for LUAD patients with high MUC5AC expression.

Ubiquitin-specific protease-7 promotes expression of airway mucin MUC5AC via the NF-κB signaling pathway

Chronic obstructive pulmonary disease (COPD) and other respiratory diseases frequently present with airway mucus hypersecretion, which not only affects the patient's quality of life but also poses a constant threat to their life expectancy. Ubiquitin-specific protease 7 (USP7), a deubiquitinating enzyme, affects cell differentiation, tissue growth, and disease development. However, its role in airway mucus hypersecretion induced by COPD remains elusive. In this study, USP7 expression was significantly upregulated in airway epithelial samples from patients with COPD, and USP7 was also overexpressed in mouse lung and human airway epithelial cells in models of airway mucus hypersecretion. Inhibition of USP7 reduced the expression of nuclear factor kappa B (NF-κB), phosphorylated-NF-κB (p-NF-κB), and phosphonated inhibitor of nuclear factor kappa B (p-IκBα), and alleviated the airway mucus hypersecretion in vivo and in vitro. Further research revealed that USP7 stimulated airway mucus hypersecretion through the activation of NF-κB nuclear translocation. In addition, the expression of mucin 5AC (MUC5AC) was suppressed by the NF-κB inhibitor erdosteine. These findings suggest that USP7 stimulates the NF-κB signaling pathway, which promotes airway mucus hypersecretion. This study identifies one of the mechanisms regulating airway mucus secretion and provides a new potential target for its prevention and treatment.

Evaluation of mucin changes between daily and extended wear silicone hydrogel contact lenses

Background: Initially, contact lenses were recommended only for daily wear because of infection and discomfort concerns. With rising demand, particularly for overnight use, extended wear lenses have gained significance. Despite concerns, intensive development of materials like Lotrafilcon B aims to meet this demand, focusing on comfort and safety.Aim: This study aimed to evaluate the mucin quantity and quality changes between daily and extended wear (Lotrafilcon B), impacting eye health and comfort.Setting: The study was conducted at Kirana Eye Center, Cipto Mangunkusumo Hospital, Jakarta, Indonesia.Methods: This study was a single-blinded randomised clinical trial with two parallel groups. Forty (40) eligible subjects willingly participated. Mucin 5AC (MUC5AC) and Ferning-type tests were conducted. The 40 subjects with moderate myopia were then divided into a daily wear and an extended wear group. The MUC5AC test was performed at pre-fitting and at 4 weeks, whereas the Ferning-type tests were taken at pre-fitting and 1st and 4th weeks.Results: For both groups, there was a significant increase in MUC5AC levels from pre-fitting to week four, but with no significant difference between them in final MUC5AC levels. Additionally, the comparison of eyes with normal and abnormal Ferning-types between the two groups showed no significant differences at pre-fitting, 1st and 4th weeks.Conclusion: There is no significant difference in MUC5AC levels with the use of daily or extended wear (with Lotrafilcon B).Contribution: This study compares the impact of daily and extended wear Lotrafilcon B contact lenses on eye health and comfort in moderate myopia patients.

INDICATORS OF MUC 5AC AND MUC 1 MUCOPOLYSACCHARIDE EXPRESSION IN THE NASAL MUCOSA OF PATIENTS WITH POSTNASAL DRIP SYNDROME AND NASAL SEPTUM DEVIATION

Introduction. Determining the cause of postnasal drip syndrome can be quite challenging. Nasal septum deformation has been recognized as one possible factor. Understanding the fundamental processes of postnasal drip syndrome is crucial for developing targeted therapeutic strategies for treating this pathology. In our study, we examined the clinical and histological features of postnasal drip syndrome in individuals with nasal septum deformation and investigated the expression of mucopolysaccharides, specifically the indicators of MUC 5AC and MUC 1.&#x0D; The aim. This study aims to investigate the clinical and histological aspects of postnasal drip syndrome (PNDS) in patients with nasal septum deformation. Specifically, the study aims to explore the expression levels of MUC5AC and MUC1 in biopsies of the nasal turbinate mucosa.&#x0D; Materials and methods. A total of 29 samples of nasal mucosa from the lower nasal turbinates were collected. These samples were divided into two groups: patients with nasal septum deviation with and without postnasal drip syndrome. Levels of MUC5AC and MUC1 were determined using Western blot analysis.&#x0D; Results. Upon analysis of histological sections, we identified a significant increase in tissue metaplasia and lymphoid infiltration in the nasal mucosa of patients with postnasal drip syndrome compared to the control group. The levels of mucopolysaccharides, MUC5AC and MUC1, were higher in the nasal mucosa of the research group compared to the control group.&#x0D; Conclusions. The obtained data suggest that anatomical changes in the nasal cavity may play a role in the development of postnasal drip syndrome through alterations in mucin secretion.

The Efficacy & Molecular Mechanisms of a Terpenoid Compound Ganoderic Acid C1 on Corticosteroid-Resistant Neutrophilic Airway Inflammation: In vivo and in vitro Validation.

Neutrophil predominant airway inflammation is associated with severe and steroid-resistant asthma clusters. Previously, we reported efficacy of ASHMI, a three-herb TCM asthma formula in a steroid-resistant neutrophil-dominant murine asthma model and further identified Ganoderic Acid C1 (GAC1) as a key ASHMI active compound in vitro. The objective of this study is to investigate GAC1 effect on neutrophil-dominant, steroid-resistant asthma in a murine model. In this study, Balb/c mice were systematically sensitized with ragweed (RW) and alum and intranasally challenged with ragweed. Unsensitized/PBS challenged mice served as normal controls. Post sensitization, mice were given 4 weeks of oral treatment with GAC1 or acute dexamethasone (Dex) treatment at 48 hours prior to challenge. Pulmonary cytokines were measured by ELISA, and lung sections were processed for histology by H&E staining. Furthermore, GAC1 effect on MUC5AC expression and on reactive oxygen species (ROS) production in human lung epithelial cell line (NCI-H292) was determined by qRT-PCR and ROS assay kit, respectively. Computational analysis was applied to select potential targets of GAC1 in steroid-resistant neutrophil-dominant asthma. Molecular docking was performed to predict binding modes between GAC1 and Dex with TNF-α. The result of the study showed that chronic GAC1 treatment, significantly reduced pulmonary inflammation (P < 0.01-0.001 vs Sham) and airway neutrophilia (P < 0.01 vs Sham), inhibited TNF-α, IL-4 and IL-5 levels (P < 0.05-0.001 vs Sham). Acute Dex treatment reduced eosinophilic inflammation and IL-4, IL-5 levels, but had no effect on neutrophilia and TNF-α production. GAC1 treated H292 cells showed decreased MUC5AC gene expression and production of ROS (P < 0.001 vs stimulated/untreated cells). Molecular docking results showed binding energy of complex GAC1-TNF was -10.8 kcal/mol. GAC1 may be a promising anti-asthma botanical drug for treatment of steroid-resistant asthma.

Abstract 2667: Mucin 5AC inhibition via intratracheal RNAi delivery as an effective alternative strategy for prevention and treatment of Kras mutant lung cancer

Abstract Lung cancer, including lung adenocarcinoma (LUAD), is the leading cause of cancer-related deaths in the United States. KRAS mutations are the most prevalent oncogenic driver alteration in human LUAD. We have previously shown that high expression of Mucin 5 AC (MUC5AC), a main airway secretory mucin, is significantly associated with poor prognosis. Mucins are essential for mucociliary clearance and the maintenance of airway homeostasis, however, their overproduction could negatively affect the lung immune microenvironment and has been shown to promote airway diseases such as chronic obstructive pulmonary disease (COPD) and lung cancer. Previously, we have shown that genetic deletion of MUC5AC in a murine model of K-ras mutant lung adenocarcinoma (KM-LUAD) impedes tumor development and reduces pro-tumor inflammatory and immune phenotypes. These findings indicate that MUC5AC is a potential druggable target against KM-LUAD. In this study, we sought a translational approach and inhibited MUC5AC in our K-rasG12D mutant mouse model of LUAD via RNA interference (RNAi). Six-week-old mice were given RNAi (5mg/kg) or vehicle (saline) via biweekly intratracheal administration for 8 weeks. This approach led to a significant decrease in tumor burden (40%) and a trending increase in total white blood cell counts, predominantly macrophages in the lung tumor microenvironment which was associated with phenotypic changes in macrophages characterized by reduced expression of Fizz1, and M2 pro-tumor macrophage marker. Additionally, RNAi-treated mice had reduced expression of Siglec-E, a mucin receptor and known inhibitor of the TLR4 endocytosis and promoter of NF-ĸB signaling, as well as a significant decrease in IL-6, a product of the NF-ĸB pathway and promoter of STAT3 signaling which we have previously shown to have an essential role in promotion of KM-LUAD. In summary, these findings elucidate a potential mechanism by which MUC5AC protects tumor cells from apoptosis and immune-mediated cytotoxic activity but also highlights how MUC5AC RNAi is an effective indirect preventive and therapeutic strategy in high-risk individuals (smokers with COPD) and patients with early stage KM-LUAD, respectively. Citation Format: Melvin Zarghooni, Maria T. Grimaldo, Avantika Krishna, Michael J. Clowers, Linda Phan, Yasmina H. Rezai, Arnav Gaitonde, Carlos Rodriguez Reyna, Walter Velasco Torrez, Erik Bush, Seyed Javad Moghaddam. Mucin 5AC inhibition via intratracheal RNAi delivery as an effective alternative strategy for prevention and treatment of Kras mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 2667.

Abstract 6675: Dissecting the relationship between mucin 5AC and the lung/gut microbiome in the pathogenesis of K-ras mutant lung cancer

Abstract Non-small cell lung cancer, including its most common subtype, lung adenocarcinoma (LUAD), is one of the most prevalent and lethal forms of cancer worldwide. This is largely due to patients having progressed to an advanced stage of disease by the time of diagnosis. Thus, better understanding the pathogenesis of early LUAD is paramount for the identification of key targets and development of preventive and therapeutic strategies for clinical management of the disease. KRAS mutations are the most common oncogenic driver alteration in human LUAD. Previously, we have found that KRAS mutant LUAD patients whose tumors harbor high expression of Mucin 5 AC (MUC5AC), a main airway secretory mucin, have significantly lower survival and poor prognosis. Mucins are membrane-bound and secreted hydrophilic proteins essential in clearance of allergens, pathogens, and debris in the lung airway. However, overproduction of mucins, such as MUC5AC, plays roles in the pathogenesis of airway diseases such as chronic obstructive pulmonary disease (COPD) and lung cancer. Given the known effect of mucin polymers on bacterial growth and the immune microenvironment in the context of other airway inflammatory diseases, in this study, our objective is to better understand the MUC5AC-to-microbiome relationship using a lung epithelial specific mouse model of KRAS-mutant LUAD (CC-LR) and test the combinatorial effects of genetic deletion of MUC5AC (CC-LR/Muc5ac−/−) and the pan-microbiome depletion on tumor progression, the lung immune contexture, and microbiome (lung and gut). Thus far, we found that genetic deletion of MUC5AC or pan-microbiome depletion significantly decreases the tumor burden (66% vs 50%, respectively). Additionally, both groups show to have a significantly decreased percentage of tumor-specific Ki67+ cells, a cell proliferation marker, and ERG+ cells, an angiogenesis marker, in comparison to the CC-LR controls. The combination of the lack of MUC5AC with pan-microbiome depletion has also shown to reduce tumor development that needs further investigation. These findings highlight the need to better understand the mechanistic interaction between mucins and the lung/gut microbiome in the context of KRAS-mutant lung cancer which we are currently exploring. It also suggests that their relationship could be a key target for modulation, potentially leading to the development of a minimally invasive alternative preventive and/or treatment modality against KRAS-mutant LUAD. Citation Format: Maria T. Grimaldo, Michael J. Clowers, Avantika Krishna, Katherine E. Larsen, Nastaran Karimi, Yasmina H. Rezai, Arnav Gaitonde, Farbod Khalaj, Haoyue Liu, Florencia McAllister, Seyed Javad Moghaddam. Dissecting the relationship between mucin 5AC and the lung/gut microbiome in the pathogenesis of K-ras mutant lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6675.