ELMO1 ameliorates intestinal epithelial cellular senescence via SIRT1/p65 signaling in inflammatory bowel disease-related fibrosis.

Background: Intestinal fibrosis is a common complication in inflammatory bowel disease (IBD), which still lacks of reliable markers and therapeutic options. Cellular senescence has been considered an important mechanism of intestinal fibrosis, but the underlying molecular link remains elusive. Methods: Tissues were stained using α-smooth muscle actin (α-SMA), fibronectin, and collagen I as markers of myofibroblastic differentiation. Cellular senescence was confirmed through Lamin B1 staining, senescence-associated ß-galactosidase staining, and the expression of senescence-associated secretory phenotype (SASP) factors. We explored the relationship between senescence of intestinal epithelial cells (IECs) and intestinal fibrosis, as well as the molecular mechanism underlying this interaction. The effects of irisin on cellular senescence and fibrosis were determined. Results: Here, we identify engulfment and cell motility protein 1 (ELMO1) as a novel biomarker for intestinal cellular senescence and fibrosis. In fibrostrictured tissues from patients and murine models with IBD, significantly high levels of cellular senescence score and factors were noted, which positively correlated with the fibrotic regulator fibronectin. Senescent IECs, not fibroblast itself, released SASP factors to regulate fibroblast activation. Prolonging exposure to severe and persistent injurious stimuli decreased ELMO1 expression, which dampened SIRT1 deacetylase activity, enhanced NF-κB (p65) acetylation, and thereby accelerated cellular senescence. Deletion of ELMO1 led to senescent IECs accumulation and triggered premature fibrosis in murine colitis. Furthermore, irisin, inhibiting the degradation of ELMO1, could downregulate p65 acetylation, reduce IECs senescence, and prevent incipient intestinal fibrosis in murine colitis models. Conclusions: This study reveals ELMO1 downregulation is an early symbol of intestinal senescence and fibrosis, and the altered ELMO1-SIRT1-p65 pathway plays an important role in intestinal cellular senescence and IBD-related fibrosis.

IL-17 is a Potential Therapeutic Target in a Rodent Model of Otitis Media with Effusion.

BACKGROUND: Otitis media with effusion (OME) is a non-suppurative inflammation of the middle ear that is characterized by middle ear effusion and hearing loss. However, the mechanisms of OME are not fully understood. The aim of this study was to determine the function and the mechanism of the IL-17 cytokine in the pathogenesis of OME and to investigate IL-17 as a potential strategy for the treatment of OME. METHODS: In this study, the OME rat model was induced by ovalbumin (OVA) as previously described. The severity of OME was determined with an oto-endoscope, by histochemical analysis, and by acoustic immittance. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis of RNA-sequencing (RNA-seq) data was carried out to analyze the signaling pathways related to the pathogenesis of OME, which indicated that IL-17 is involved in OME. The anti-IL-17A monoclonal antibody was administrated by nasal drip to block IL-17 to treat OME in the rat model. The rats were finally injected intraperitoneally with the inhibitor of Notch signaling pathway to study the mechanisms of IL-17-induced inflammation. Serum and lavage fluid were collected for the detection of related cytokines, and middle ear tissue was collected for Western blot, quantitative real-time PCR (qRT-PCR), and immunohistochemical and immunofluorescence analysis. RESULTS: KEGG analysis of RNA-seq data suggested that the IL-17 signaling pathway might be involved in the onset of OME. IL-17 expression was confirmed to be increased in both the serum and the middle ear of the rat model. The monoclonal antibody against IL-17 neutralized IL-17, inhibited the inflammation in the middle ear, and reduced the overall severity of OME in vivo. Furthermore, the Notch signaling pathway was activated upon IL-17 upregulation in OME and was suppressed by IL-17 blockage. However, there was no change in IL-17 expression after Notch inhibitor treatment, which reduced the severity of OME in the rat middle ear. CONCLUSION: IL-17 plays a key role in the pathogenesis of the OVA-induced OME rat model. IL-17 induced inflammatory responses via the Notch signaling pathway and targeting IL-17 might be an effective approach for OME therapy.

Asiatic Acid Improves Extracellular Matrix Remodeling in Vocal Fold Scarring Via SMAD7 Activation.

OBJECTIVES/HYPOTHESIS: Vocal fold (VF) fibroblasts are the central target for developing new strategies for the treatment of VF scarring and fibrosis. Asiatic acid (AA) is a triterpenoid derivate with antifibrotic properties. However, the effect of AA in VF scarring is poorly understood. The objective of this study was to investigate the potential application of AA as a therapeutic treatment in VF scarring. STUDY DESIGN: Xxxxx. METHODS: The functional expression of SMAD7 was knocked down with recombinant adenoviruses and adeno-associated viruses carrying shRNAs in the in vitro and in vivo models, which were constructed to investigate AA's antifibrotic function. The expression of collagens and SMADs in cultured human and rabbit cell lines and animal models was evaluated with quantitative reverse transcription polymerase chain reaction and immunohistochemistry labeling, respectively. Cell migration capacity and contraction in VF fibroblast cell lines were also evaluated. RESULTS: AA downregulated the downstream fibrotic activation in a dose-dependent manner. Meanwhile, AA attenuated VF scarring/fibrosis by reducing collagen deposition. Furthermore, the antifibrotic effects of AA were associated with the upregulation of SMAD7. In contrast, knockdown of SMAD7 inhibited the effect of AA on transforming growth factor-beta-1 (TGF-ß1) stimulation, which suggests a central role for SMAD7 in AA-induced antifibrotic activities during VF fibrosis. CONCLUSION: We concluded that AA, which is a novel therapeutic candidate for preventing VF scarring/fibrosis, might exert its antifibrotic effect via the TGF-ß1/SMAD signaling pathway. LEVEL OF EVIDENCE: NA Laryngoscope, 132:1237-1244, 2022.

Laryngopharyngeal Reflux and Inflammatory Responses in Mucosal Barrier Dysfunction of the Upper Aerodigestive Tract.

The upper aerodigestive tract (UAT) is the first line of defense against environmental stresses such as antigens, microbes, inhalants, foods, etc., and mucins, intracellular junctions, epithelial cells, and immune cells are the major constituents of this defensive mucosal barrier. Laryngopharyngeal reflux (LPR) is recognized as an independent risk factor for UAT mucosal disorders, and in this review, we describe the components and functions of the mucosal barrier and the results of LPR-induced mucosal inflammation in the UAT. We discuss the interactions between the refluxate and the mucosal components and the mechanisms through which these damaging events disrupt and alter the mucosal barriers. In addition, we discuss the dynamic alterations in the mucosal barrier that might be potential therapeutic targets for LPR-induced disorders.

Clinical Significance of Low 2-Methoxyestradiol Levels in Serum and Tissue of Recurrent Juvenile-Onset Laryngeal Papillomatosis.

Objective We aim to explore the correlation between serum and tissue 2-methoxyestradiol (2-ME-2) levels and recurrence of juvenile-onset respiratory papillomatosis (JORRP). Study Design Retrospective cohort studies. Settings Laboratory of Otolaryngology, Department of Head and Neck Surgery, Renji Hospital, School of Medicine, Shanghai Jiaotong University. Subjects and Methods Sixty-four patients diagnosed with JORRP in our department from January 2007 to December 2012 were enrolled. Patients were divided into recurrence and nonrecurrence groups, with 32 patients in each group. ELISA detected the concentration of 2-ME-2 in serum and tissue samples collected during the first surgical procedure. Mann-Whitney analysis, receiver operating characteristic curves, logistic regression model, and Kaplan-Meier method were used for data processing. Results There was no difference in the serum 2-ME-2 concentration between the groups ( P = .237), while the tissue 2-ME-2 concentration of the recurrent group was significantly lower than that of the nonrecurrence group ( P = .0001). When the area under the curve was 0.752, the cutoff value of tissue 2-ME-2 at 670.02 pg/mL yielded the highest predictive sensitivity (71.9%) and specificity (71.9%). Regrouped by this cutoff point, patients with a lower tissue 2-ME-2 level (n = 26) had shorter disease-free survival and a higher recurrence odds ratio than patients with a higher tissue 2-ME-2 level (n = 38; P = .0408, odds ratio = 7.667). Conclusion A low tissue 2-ME-2 level is associated with a higher recurrence rate of JORRP. Tissue 2-ME-2 may be an effective target for JORRP treatment and a convenient measure for recurrence monitoring.