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Chitinase 3-like 1 (also known as CHI3L1 or YKL-40) is a mammalian chitinase that has no enzymatic activity, but has the ability to bind to chitin, the polymer of N-acetylglucosamine (GlcNAc). Chitin is a component of fungi, crustaceans, arthropods including insects and mites, and parasites, but it is completely absent from mammals, including humans and mice. In general, chitin-containing organisms produce mammalian chitinases, such as CHI3L1, to protect the body from exogenous pathogens as well as hostile environments, and it was thought that it had a similar effect in mammals. However, recent studies have revealed that CHI3L1 plays a pathophysiological role by inducing anti-apoptotic activity in epithelial cells and macrophages. Under chronic inflammatory conditions such as inflammatory bowel disease and chronic obstructive pulmonary disease, many groups already confirmed that the expression of CHI3L1 is significantly induced on the apical side of epithelial cells, and activates many downstream pathways involved in inflammation and carcinogenesis. In this review article, we summarize the expression of CHI3L1 under chronic inflammatory conditions in various disorders and discuss the potential roles of CHI3L1 in those disorders on various cell types. [ABSTRACT FROM AUTHOR]

Abstract Background Acute kidney injury (AKI) is a prevalent complication following acute type A aortic dissection (ATAAD) surgery and is closely associated with unfavorable prognostic outcomes. Hence, the development of a robust and efficient diagnostic approach to identify high-risk patients is of paramount importance. Methods We conducted a prospective study involving 328 patients who underwent ATAAD surgery at our institution, comprising three distinct cohorts. In addition, 52 patients undergoing alternative cardiopulmonary surgeries and 37 healthy individuals were enrolled as control groups. Employing proteomic analysis, we initially identified plasma proteins potentially linked to AKI occurrence within the plasma proteomic cohort. Subsequent validation was performed in an independent cohort. Utilizing predictors derived from multivariate logistic regression analysis, a nomogram was meticulously formulated and its efficacy was validated in the model construction cohort. Results Proteomics revealed significant elevation of plasma levels of S100A8/A9, pentraxin 3 (PTX3), and chitinase 3-like 1 (CHI3L1) immediately post-surgery in patients who developed ATAAD surgery-associated AKI (ASA-AKI). Receiver operating characteristic (ROC) curves demonstrated impressive predictive performance of S100A8/A9, PTX3, and CHI3L1 at 0 h post-surgery, yielding area under the curve (AUC) values of 0.823, 0.786, and 0.803, respectively, for ASA-AKI prediction. Furthermore, our findings exhibited positive correlations between plasma levels of S100A8/A9, PTX3, CHI3L1, and urinary neutrophil gelatinase-associated lipocalin (NGAL) at 0 h post-surgery, along with correlations between plasma S100A8/A9, CHI3L1 levels, and the Cleveland Clinic score. A logistic regression model incorporating plasma S100A8/A9, PTX3, CHI3L1 levels, urinary NGAL levels, and the Cleveland Clinic score facilitated the construction of a predictive nomogram for ASA-AKI. This nomogram demonstrated robust discriminative ability, achieving an AUC of 0.963 in the model construction cohort. Conclusions Our study underscored the augmentation of plasma S100A8/A9, PTX3, and CHI3L1 levels immediately post-surgery in patients developing ASA-AKI. The incorporation of these three biomarkers, in conjunction with the Cleveland Clinic score and NGAL, into a nomogram demonstrated commendable predictive efficacy. This presents a practical tool for identifying patients at an elevated risk of AKI following ATAAD surgery.

Background: Acute kidney injury (AKI) is a prevalent complication following acute type A aortic dissection (ATAAD) surgery and is closely associated with unfavorable prognostic outcomes. Hence, the development of a robust and efficient diagnostic approach to identify high-risk patients is of paramount importance. Methods: We conducted a prospective study involving 328 patients who underwent ATAAD surgery at our institution, comprising three distinct cohorts. In addition, 52 patients undergoing alternative cardiopulmonary surgeries and 37 healthy individuals were enrolled as control groups. Employing proteomic analysis, we initially identified plasma proteins potentially linked to AKI occurrence within the plasma proteomic cohort. Subsequent validation was performed in an independent cohort. Utilizing predictors derived from multivariate logistic regression analysis, a nomogram was meticulously formulated and its efficacy was validated in the model construction cohort. Results: Proteomics revealed significant elevation of plasma levels of S100A8/A9, pentraxin 3 (PTX3), and chitinase 3-like 1 (CHI3L1) immediately post-surgery in patients who developed ATAAD surgery-associated AKI (ASA-AKI). Receiver operating characteristic (ROC) curves demonstrated impressive predictive performance of S100A8/A9, PTX3, and CHI3L1 at 0 h post-surgery, yielding area under the curve (AUC) values of 0.823, 0.786, and 0.803, respectively, for ASA-AKI prediction. Furthermore, our findings exhibited positive correlations between plasma levels of S100A8/A9, PTX3, CHI3L1, and urinary neutrophil gelatinase-associated lipocalin (NGAL) at 0 h post-surgery, along with correlations between plasma S100A8/A9, CHI3L1 levels, and the Cleveland Clinic score. A logistic regression model incorporating plasma S100A8/A9, PTX3, CHI3L1 levels, urinary NGAL levels, and the Cleveland Clinic score facilitated the construction of a predictive nomogram for ASA-AKI. This nomogram demonstrated robust discriminative ability, achieving an AUC of 0.963 in the model construction cohort. Conclusions: Our study underscored the augmentation of plasma S100A8/A9, PTX3, and CHI3L1 levels immediately post-surgery in patients developing ASA-AKI. The incorporation of these three biomarkers, in conjunction with the Cleveland Clinic score and NGAL, into a nomogram demonstrated commendable predictive efficacy. This presents a practical tool for identifying patients at an elevated risk of AKI following ATAAD surgery. [ABSTRACT FROM AUTHOR]

Chitinase 3‐like 1 (CHI3L1 or YKL40) is a secreted glycoprotein highly expressed in advanced stages of several cancer types, including prostate cancer (PCa). Impacts of genetic variants of CHI3L1 on PCa development have not yet been investigated. The most common well‐studied genetic variations are single‐nucleotide polymorphisms (SNPs). Therefore, the objective of this study was to explore associations of CHI3L1 SNPs with both the susceptibility to PCa and its clinicopathological development. Three promoter SNPs, rs6691378 (−1371, G>A), rs10399805 (−247, G>A) and rs4950928 (−131, C>G), and one non‐synonymous SNP, rs880633 (+2950, T>C), were analysed using a TaqMan allelic discrimination assay for genotyping in a cohort of 701 PCa patients and 701 healthy controls. Results indicated that there were no significant associations of PCa susceptibility with these four CHI3L1 SNPs. However, among elderly PCa patients (aged >65 years), it was observed that polymorphic variants (GA + AA) of CHI3L1 rs6691378 and 10399805 were significantly linked to reduced risks of several clinicopathological characteristics, including a high Gleason grade, advanced pathologic T stage and tumour cell invasion. Moreover, analyses of The Cancer Genome Atlas database revealed that CHI3L1 expression levels were elevated in PCa tissues compared with normal tissues. Interestingly, higher CHI3L1 expression levels were found to be associated with longer progression‐free survival rates in PCa patients. Our findings indicated that levels of CHI3L1 may influence the progression of PCa, and the rs6691378 and 10399805 SNP genetic variants of CHI3L1 are linked to the clinicopathological development of PCa within a Taiwanese population. [ABSTRACT FROM AUTHOR]

AIM: To evaluate the potential of two trabecular meshwork (TM)-specific promoters, Chitinase 3-like 1 (Ch3L1) and matrix gla protein (MGP), for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2 (scAAV2) vector technologies. METHODS: An scAAV2 vector with C3 transferase (C3) as the reporter gene (scAAV2-C3) was selected. The scAAV2-C3 vectors were driven by Ch3L1 (scAAV2-Ch3L1-C3), MGP (scAAV2-MGP-C3), enhanced MGP (scAAV2-eMGP-C3) and cytomegalovirus (scAAV2-CMV-C3), respectively. The cultured primary human TM cells were treated with each vector at different multiplicities of infections. Changes in cell morphology were observed by phase contrast microscopy. Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining, real-time quantitative polymerase chain reaction and Western blot. Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively. In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope. Intraocular pressure (IOP) was monitored using a rebound tonometer. Ocular responses were evaluated by slit-lamp microscopy. Ocular histopathology analysis was examined by hematoxylin and eosin staining. RESULTS: In TM cell culture studies, the vector-mediated C3 expression induced morphologic changes, disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rho-associated protein kinase signaling pathway. At the same dose, these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3, but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3. At low-injected dose, the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGP-C3-injected and scAAV2-eMGP-C3-injected eyes. At high-injected dose, significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes. Similar to scAAV2-CMV-C3, scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium. In anterior segment tissues of scAAV2-eMGP-C3-injected eyes, no obvious morphological changes were found except for the TM. Inflammation was absent. CONCLUSION: In scAAV2-transduced TM cells, the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus, but obviously higher than that of MGP. In the anterior chamber of rat eye, the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter, but not by Ch3L1 promoter. These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector.

Caffeine (1,3,7-trimethylxanthine, also abbreviated to CAF) is a natural chemical with stimulant effects and is commonly included in many drinks and foods, including coffee, tea, cola, energy drinks, cocoa, chocolates, and so on. Our group previously reported that oral administration of CAF efficiently suppressed the development of intestinal inflammation in a dextran sulfate sodium (DSS)-induced murine acute colitis model by suppressing the expression of chitinase 3-like 1, one of the mammalian chitinases without enzymatic activity. Chitinases are hydrolytic enzymes that break down chitin, a polymer of N-acetylglucosamine, and chitinase-like proteins have no enzymatic activity with preserving chitin-binding ability. CAF binds a cleft of the chitinase active site and plays a role as a pan-chitinase inhibitor. Although CAF showed an anti-inflammatory effect in the above model, oral administration of low-dose CAF with 10% sucrose showed potentially neoplastic effects in colonic epithelial cells in a DSS-induced murine chronic colitis model. In this review, we would like to discuss the pros and cons of coffee/CAF in colonic inflammation and neoplasia with an example of pathological finding.

Chitinase 3-like 1 (also known as CHI3L1 or YKL-40) is a mammalian chitinase that has no enzymatic activity, but has the ability to bind to chitin, the polymer of N-acetylglucosamine (GlcNAc). Chitin is a component of fungi, crustaceans, arthropods including insects and mites, and parasites, but it is completely absent from mammals, including humans and mice. In general, chitin-containing organisms produce mammalian chitinases, such as CHI3L1, to protect the body from exogenous pathogens as well as hostile environments, and it was thought that it had a similar effect in mammals. However, recent studies have revealed that CHI3L1 plays a pathophysiological role by inducing anti-apoptotic activity in epithelial cells and macrophages. Under chronic inflammatory conditions such as inflammatory bowel disease and chronic obstructive pulmonary disease, many groups already confirmed that the expression of CHI3L1 is significantly induced on the apical side of epithelial cells, and activates many downstream pathways involved in inflammation and carcinogenesis. In this review article, we summarize the expression of CHI3L1 under chronic inflammatory conditions in various disorders and discuss the potential roles of CHI3L1 in those disorders on various cell types.

Chitinase 3‐like 1 (Chi3L1) is associated with various biological processes, such as inflammation, tissue repair, proliferation, cell survival, invasion, and extracellular matrix remodeling. Recent studies indicated that Chi3L1 is critical for cancer development and metastasis. In this study, we demonstrate that Chi3L1 serum and tissue levels were significantly increased in lung cancer patients compared with controls. We previously developed an anti‐Chi3L1‐humanized antibody, and here, we investigate its antitumor and antimetastatic effect. The anti‐Chi3L1 antibody attenuated tumor growth and metastasis both in vitro and in vivo in a lung cancer mouse model. These inhibitory effects are associated with signal transducer and activator of transcription 6 (STAT6)‐dependent M2 polarization inhibition. Proteomics analysis revealed that plasminogen (PLG) interacts with Chi3L1 and affects M2 polarization. Chi3L1 plays a critical role in lung cancer progression, and the anti‐Chi3L1 antibody could be a new anticancer therapy.

Objective: Anti-leucine-rich glioma inactivated 1(LGI1) encephalitis is one rare autoimmune encephalitis which is accompanied by inflammatory responses. (Anti-leucine-rich glioma inactivated 1 (anti-LGI1) encephalitis is an autoimmune disease mediated by inflammatory responses.)This study aimed to investigate the Chitinase 3-like 1(CHI3L1) in anti-LGI1encephalitis patients and evaluate its association with modified Rankin Scale (mRS) score in anti-LGI1 encephalitis at admission and 6 months follow-up.(This study looked into the relationship between Chitinase 3-like 1 (CHI3L1) and the modified Ranking Scale (mRS) score in anti-LGI1 encephalitis patients at admission and 6 months later.) Methods: Thirty-five patients with anti-LGI1 encephalitis and 22 patients with non-inflammatory neurological disease were enrolled in this study. (We enrolled 35 patients with anti-LGI1 encephalitis and 22 patients with noninflammatory neurological disease.)Cerebrospinal fluid (CSF) and serum levels of CHI3L1 were measured by enzyme-linked immunosorbent assay. (We quantified CHI3L1 in the serum and cerebrospinal fluid (CSF) by performing an enzyme-linked immunosorbent assay.)Patients were evaluated for mRS score at admission and at 6 months follow-up.(We recorded the mRS score of the patients at admission and 6 months later.) Results: CHI3L1 levels in CSF and serum were highly elevated in patients with anti-LGI1 encephalitis at admission compared those with the controls.(At admission, patients with anti-LGI1 encephalitis had elevated CHI3L1 levels in the CSF and serum.) Additionally, patients presenting with cognitive impairment had significantly higher CSF CHI3L1 levels and mRS scores than those without cognitive impairment symptoms. Patients presenting with only faciobrachial dystonic seizures at admission had lower CSF CHI3L1 levels than those with other symptoms. Finally, CSF CHI3L1 levels were positively correlated with CSF lactate levels. Conclusion: CHI3L1 level in CSF is correlated with the severity and prognosis of anti-LGI1 encephalitis. (CSF CHI3L1 levels are correlated with the severity and prognosis of anti-LGI1 encephalitis.) [ABSTRACT FROM AUTHOR]

Aims: The aim of this study was to evaluate the association of serum neurofilament heavy chain (sNfH) and chitinase 3-like 1 (sCHI3L1) with treatment response and disease activity in multiple sclerosis (MS)., Methods: This single-center, prospective, observational cohort study was conducted at the MS Centre, University Hospital Ostrava, Czech Republic, from May 2020 to August 2023. sNfH and sCHI3L1 were determined using ELISA. A mixed-effects linear model with a log-transformed outcome variable was applied., Results: We analyzed 459 samples from 57 people with MS. Patients were sampled an average of 8.05 times during 21.9 months of follow-up. Those experiencing a relapse at sampling had a sNfH concentration 50 % higher than those in remission (exp(β) 1.5, 95 % CI 1.15-1.96). A longer duration of treatment was associated with lower sNfH (exp(β) 0.95, 95 % CI 0.94-0.96). Patients switched from low- to high-efficacy disease-modifying therapies (DMTs) had higher sNfH than patients treated with low-efficacy DMTs only (exp(β) 1.95, 95 % CI 1.35-2.81). Higher sCHI3L1 was associated with older age (exp(β) 1.01, 95 % CI 1.00-1.02) and longer DMT use (exp(β) 1.01, 95 % CI 1.00-1.02). sCHI3L1 values were not associated with relapse at the time of sampling, renal function, sex, or type of DMT., Conclusion: In contrast to sCHI3L1, sNfH may be a potential biomarker for monitoring treatment response and confirming clinical relapse in MS. Further research is needed to determine the long-term dynamics of sNfH and develop related treatment strategies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Chitinase 3-like 1 (CHI3L1) is an important factor involved in the development of asthma. This meta-analysis assessed the association of the CHI3L1 polymorphisms rs4950928, rs10399931, rs883125, rs880633, and rs10399805 with asthma risk. Methods: The literature searches were conducted in PubMed, Web of Science, Wanfang, and China National Knowledge Infrastructure up until September 4, 2021, for relevant studies. Sixteen publications with 18 studies involving 5,005 asthma patients and 9,725 controls were included in this meta-analysis. Results: The meta-analyses showed that among East-Asian subjects, increased asthma risk was associated with CHI3L1 rs4950928 (GG + CG vs. CC: odds ratio [OR] = 1.43, 95% confidence interval [CI]: 1.09–1.88, p = 0.011; GG vs. CG + CC: OR = 1.64, 95% CI: 1.20–2.26, p = 0.002; GG vs. CC: OR = 1.97, 95% CI: 1.41–2.75, p = 0.000; and G vs. C: OR = 1.36, 95% CI: 1.12–1.66, p = 0.002) and rs883125 (G vs. C: OR = 1.42, 95% CI: 1.01–1.99, p = 0.043), whereas CHI3L1 rs10399931 was associated with reduced asthma risk (TT vs. CT + CC: OR = 0.79, 95% CI: 0.64–0.99, p = 0.038; TT vs. CC: OR = 0.77, 95% CI: 0.61–0.98, p = 0.030). In addition, we found an association between CHI3L1 rs4950928 and asthma risk in adult subjects but not children, while CHI3L1 rs883125 was associated with asthma risk in children. Conclusion: The CHI3L1 polymorphisms rs4950928, rs10399931, and rs883125 are important genetic factors for asthma among East-Asian subjects. [ABSTRACT FROM AUTHOR]

Background and Aims The mechanism of action of anti-tumour necrosis factor [anti-TNF] agents could implicate macrophage modulation in Crohn's disease [CD]. As CD macrophages are defective in controlling CD-associated adherent-invasive Escherichia coli [AIEC], anti-TNF agents could limit AIEC replication within macrophages. We assessed the effect of anti-TNF agents on AIEC survival within monocyte-derived macrophages [MDMs] from CD patients and attempted to identify the proteins involved. Methods Peripheral blood MDMs were obtained from 44 CD patients [22 with and 22 without anti-TNF agents]. MDMs were infected with reference strain AIEC-LF82. Proteomic analysis was performed before and 6 h after AIEC-LF82 infection. Results AIEC-LF82 survival was lower in MDMs from CD patients receiving anti-TNF agents compared to those who did not [−73%, p = 0.006]. After AIEC-LF82 infection, the levels of CD82 [ p = 0.007], ILF3 [Interleukin enhancer-binding factor 3; p = 0.001], FLOT-1 [Flotillin-1; p = 0.007] and CHI3L1 [Chitinase 3-like 1; p = 0.035] proteins were different within CD-MDMs depending on anti-TNF exposure. FLOT-1 [ϱ = −0.44; p = 0.038] and CHI3L1 [ϱ = 0.57, p = 0.006] levels were inversely and positively correlated with AIEC survival within MDMs from CD patients with or without anti-TNF, respectively. We observed a dose-dependent decrease of AIEC-LF82 survival after adjunction of anti-TNF within MDMs, inducing an increase of FLOT-1 and decrease of CHI3L1 mRNA levels. Neutralization of intra-macrophagic CHI3L1 protein using anti-CHI3L1 antibodies reduced AIEC survival within macrophages 6 h after infection [ p < 0.05]. Conclusion Anti-TNF agents are able to restrict replication of pathobionts, such as AIEC, within macrophages by modulating FLOT-1 and CHI3L1 expression in CD patients. [ABSTRACT FROM AUTHOR]

Chitinase 1 (CHIT1) and chitinase 3-like-1 (CHI3L1), two representative members of 18-Glycosyl hydrolases family, are significantly implicated in the pathogenesis of various human diseases characterized by inflammation and remodeling. Notably, dysregulated expression of CHIT1 and CHI3L1 was noted in the patients with pulmonary fibrosis and their levels were inversely correlated with clinical outcome of the patients. CHIT1 and CHI3L1, mainly expressed in alveolar macrophages, regulate profibrotic macrophage activation, fibroblast proliferation and myofibroblast transformation, and TGF-β signaling and effector function. Although the mechanism or the pathways that CHIT1 and CHI3L1 use to regulate pulmonary fibrosis have not been fully understood yet, these studies identify CHIT1 and CHI3L1 as significant modulators of fibroproliferative responses leading to persistent and progressive pulmonary fibrosis. These studies suggest a possibility that CHIT1 and CHI3L1 could be reasonable therapeutic targets to intervene or reverse established pulmonary fibrosis. In this review, we will discuss specific roles and regulatory mechanisms of CHIT1 and CHI3L1 in profibrotic cell and tissue responses as novel therapeutic targets of pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

OBJECTIVE: To probe into the correlation between chitinase 3-like 1 ( CHJ3Ll ) gene polymorphism and efficacy of inhaled glucocorticoid in children with bronchial asthma. METHODS: Totally 142 children with bronchial asthma treated in this hospital from 2019 to 2020 were extracted as the observation group and received inhaled glucocorticoid therapy. And 92 healthy children under physical examination during the same period were selected as the control group. Single nucleotide polymorphisms at rs883125, rs4950928, and rsl0399805 of CHJ3Ll gene were detected by Mass ARRAY-IPLEX mass spectrometry array method. Forced vital capacity ( FVC ), forced expiratory volume in one second( FEV1 ), FEV1/FVC before and after treatment were detected in the observation group by micron MAS-99 pulmonary function tester. The genotype frequency of rs883125, rs4950928 and rs10399805 of CHI3Ll gene was compared between the observation group and the control group. The genotype frequency of rs883125, rs4950928 and rs10399805 of CHI3Ll gene was compared in the observation group with different curative effects. The difference of pulmonary function indicators at rs883125, rs4950928 and rs10399805 of CHI3Ll gene was compared in the observation group before and after treatment. RESULTS: The frequency of GG gene distribution at rs883125 was significantly higher in the observation group than in the control group, the frequency of CC gene distribution at rs4950928 was significantly lower than that in the control group, and the frequency of CG gene distribution was significantly higher than that in the control group, with statistically significant differences( P 0. 05). After 12 weeks of inhaled glucocorticoid treatment in 142 children with bronchial asthma, the good control rate was 69. 01%(98/142), the frequency of GG gene distribution at rs883125 in the good curative effect group was significantly lower than that in the poor curative effect group, and the CC gene distribution frequency at rs4950928 was significantly higher than that in the poor curative effect group, with statistically significant differences ( P < 0. 05), there was no statistically significant difference in the genotype frequency of rsl0399805 in different therapeutic groups ( P > 0. 05 ) . The difference of CC type, CG type FVC, FEV 1, FEV 1 /FVC at rs883125 was significantly higher than that of GG type, the difference of CC type FVC, FEV 1, FEV 1 /FVC at rs4950928 was significantly higher than that of CG type and GG type, the difference of GG type FVC, FEV 1, FEV 1/FVC at rs4950928 was significantly higher than that of CG type, with statistically significant differences(PO. 05) . CONCLUSIONS : The single nucleotide polymorphisms at rs883125 and rs4950928 of CHJ3Ll gene are related to the efficacy of inhaled glucocorticoid in children with bronchial asthma. [ABSTRACT FROM AUTHOR]

Background: Liver biopsy is the gold-standard method for diagnosing and staging liver fibrosis, but the procedure is invasive, not available in the primary health care facilities, and not free from complications. Noninvasive serum biomarkers of hepatic fibrosis are the current research focus. Objectives: To assess the correlation between serum Chitinase 3-like 1 (CHI3L1) levels and histological severity in patients with Hepatitis B Virus (HBV)-related compensated chronic liver disease (CLD). Material and Methods: This cross-sectional study evaluated 50 treatment-naïve patients with chronic hepatitis B with compensated CLD. Liver biopsy was done, and hepatic fibrosis was categorized using the METAVIR scoring system; we divided the study subjects into three groups; group 1 included subjects with F0 and F1, group 2 having F2 group 3 having F3 and F4. Serum CHI3L1 was measured in all by immunoassay. Result: Among 50 patients, only one had METAVIR score F0, seven had F1, 33 had F2, nine had F3, and none had METAVIR score F4. The median value of CHI3L1 was 460.8 (IQR 340.1-570.3) in all study subjects; 359.5 (IQR 272.8-526.9) in group 1, 450.0 (IQR 307.75-5332.0) in group 2, and 1355.5 (IQR 530.75-1580.5) in the group 3. The difference in median CHI3L1 across the groups was statistically significant. Serum aspartate aminotransferase (AST) and the AST to Platelet Ratio Index (APRI) score had significant positive correlations with CHI3L1 levels. CHI3L1 also had significant positive correlations with METAVIR scores. Conclusion: This study found a positive correlation between serum CHI3L1 level and hepatic histological severity in patients with HBV-related compensated CLD. Further larger-scale research is needed to establish the fact.

Chitinase 1 (CHIT1) and chitinase 3-like-1 (CHI3L1), two representative members of 18-Glycosyl hydrolases family, are significantly implicated in the pathogenesis of various human diseases characterized by inflammation and remodeling. Notably, dysregulated expression of CHIT1 and CHI3L1 was noted in the patients with pulmonary fibrosis and their levels were inversely correlated with clinical outcome of the patients. CHIT1 and CHI3L1, mainly expressed in alveolar macrophages, regulate profibrotic macrophage activation, fibroblast proliferation and myofibroblast transformation, and TGF-β signaling and effector function. Although the mechanism or the pathways that CHIT1 and CHI3L1 use to regulate pulmonary fibrosis have not been fully understood yet, these studies identify CHIT1 and CHI3L1 as significant modulators of fibroproliferative responses leading to persistent and progressive pulmonary fibrosis. These studies suggest a possibility that CHIT1 and CHI3L1 could be reasonable therapeutic targets to intervene or reverse established pulmonary fibrosis. In this review, we will discuss specific roles and regulatory mechanisms of CHIT1 and CHI3L1 in profibrotic cell and tissue responses as novel therapeutic targets of pulmonary fibrosis.

Viral respiratory infection causes inflammatory lung disease. Chitinase 3-like 1 (CHI3L1) contributes to airway inflammation, but its role in human airway epithelial cells following viral infection is unclear. Thus, we investigated whether CHI3L1 regulates inflammatory responses caused by viral infections in airway epithelial cells. Human bronchial epithelial cells, BEAS-2B, were stimulated with a synthetic analog of viral double-stranded RNA, polyinosinic:polycytidylic acid (poly(I:C)). To confirm the specific role of CHI3L1, CHI3L1 was knocked down in BEAS-2B cells using shRNA lentivirus. The expression of CHI3L1 and proinflammatory cytokines such as IL-8 and phosphorylation of mitogen-activated protein kinase (MAPK) pathways were analyzed. In addition to poly(I:C), BEAS-2B cells were infected with the human respiratory syncytial virus (RSV) A2 strain, and CHI3L1 and IL-8 expression was analyzed. Stimulating the cells with poly(I:C) increased CHI3L1 and IL-8 expression, whereas IL-8 expression was abrogated in CHI3L1 knockdown BEAS-2B cells. Poly(I:C) stimulation of BEAS-2B cells resulted in phosphorylation of MAPK pathways, and inhibition of MAPK pathways significantly abolished IL-8 secretion. Phosphorylation of MAPK pathways was diminished in CHI3L1 knockdown BEAS-2B cells. Infection with RSV increased CHI3L1 and IL-8 expression. IL-8 expression induced by RSV infection was abrogated in CHI3L1 knockdown cells. In conclusion, CHI3L1 may be involved in IL-8 secretion by regulating MAPK pathways during respiratory viral infections in airway epithelial cells. • CHI3L1 and pro-inflammatory cytokines are associated with viral infections. • CHI3L1 is involved in IL-8 expression by regulating MAPK pathway activation. • We clarified the cell inflammatory mechanisms during respiratory viral infections. [ABSTRACT FROM AUTHOR]

Background: Liver biopsy is the gold-standard method for diagnosing and staging liver fibrosis, but the procedure is invasive, not available in the primary health care facilities, and not free from complications. Noninvasive serum biomarkers of hepatic fibrosis are the current research focus. Objectives: To assess the correlation between serum Chitinase 3-like 1 (CHI3L1) levels and histological severity in patients with Hepatitis B Virus (HBV)-related compensated chronic liver disease (CLD). Material and Methods: This cross-sectional study evaluated 50 treatment-naïve patients with chronic hepatitis B with compensated CLD. Liver biopsy was done, and hepatic fibrosis was categorized using the METAVIR scoring system; we divided the study subjects into three groups; group 1 included subjects with F0 and F1, group 2 having F2 group 3 having F3 and F4. Serum CHI3L1 was measured in all by immunoassay. Result: Among 50 patients, only one had METAVIR score F0, seven had F1, 33 had F2, nine had F3, and none had METAVIR score F4. The median value of CHI3L1 was 460.8 (IQR 340.1-570.3) in all study subjects; 359.5 (IQR 272.8-526.9) in group 1, 450.0 (IQR 307.75-5332.0) in group 2, and 1355.5 (IQR 530.75-1580.5) in the group 3. The difference in median CHI3L1 across the groups was statistically significant. Serum aspartate aminotransferase (AST) and the AST to Platelet Ratio Index (APRI) score had significant positive correlations with CHI3L1 levels. CHI3L1 also had significant positive correlations with METAVIR scores. Conclusion: This study found a positive correlation between serum CHI3L1 level and hepatic histological severity in patients with HBV-related compensated CLD. Further larger-scale research is needed to establish the fact. [ABSTRACT FROM AUTHOR]

In July 1992, my 24 years of studying abroad in the US as a researcher at Harvard Medical School started. During this period, I met many outstanding scholars who conducted some of the world's leading research projects. In particular, the opportunity to collaborate with Dr. Jack A. Elias, Professor and Dean Emeritus of the Faculty of Medicine at Brown University, on a project focusing on a molecule called Chitinase 3-like 1 was very helpful to my career, and eventually led to my current position as Professor in charge of international medical exchange at Kurume University School of Medicine. By strengthening the foundation of our exchange programs and actively promoting international joint research projects, I would like to raise the global name recognition of Kurume University.

Abstract Background Murine breast cancer models relying on intraductal tumor cell inoculations are attractive because they allow the study of breast cancer from early ductal carcinoma in situ to metastasis. Using a fully immunocompetent 4T1-based intraductal model for triple-negative breast cancer (TNBC) we aimed to investigate the immunological responses that guide such intraductal tumor progression, focusing on the prominent role of macrophages. Methods Intraductal inoculations were performed in lactating female mice with luciferase-expressing 4T1 mammary tumor cells either with or without additional RAW264.7 macrophages, mimicking basal versus increased macrophage-tumor cell interactions in the ductal environment. Imaging of 4T1-derived luminescence was used to monitor primary tumor growth and metastases. Tumor proliferation, hypoxia, disruption of the ductal architecture and tumor immune populations were determined immunohistochemically. M1- (pro-inflammatory) and M2-related (anti-inflammatory) cytokine levels were determined by Luminex assays and ELISA to investigate the activation state of the macrophage inoculum. Levels of the metastatic proteins matrix metalloproteinase 9 (MMP-9) and vascular endothelial growth factor (VEGF) as well as of the immune-related disease biomarkers chitinase 3-like 1 (CHI3L1) and lipocalin 2 (LCN2) were measured by ELISA to evaluate disease progression at the protein level. Results Mice intraductally co-injected with macrophages showed severe splenomegaly with faster ductal breakthrough of tumor cells and increased metastases in axillary lymph nodes and lungs. These mice showed higher M1-related cytokines in the early disease stages (at 1 to 3 weeks post-inoculation) due to the pro-inflammatory nature of RAW264.7 macrophages with increased Ly6G-positive neutrophils and decreased anti-inflammatory macrophages in the tumor microenvironment. However, upon metastasis (at 5 weeks post-inoculation), a prominent increase in M2-related cytokine levels was detected and established a tumor microenvironment with similar immune populations and cytokine responses as in mice which received only 4T1 tumor cells. The observed tumor-associated immune responses and the increased metastasis were associated with significantly induced local and systemic levels of MMP-9, VEGF, CHI3L1 and LCN2. Conclusions The current experimental study with an innovative immunocompetent intraductal model for TNBC pinpoints towards a metastasis-supporting M1 to M2 macrophage polarization in the mammary ducts mediated by 4T1-derived signaling. We propose to explore this process as immunotherapeutic target.

Abstract Background Single nucleotide polymorphisms (SNPs) in chitinase 3-like 1 (CHI3L1) are associated with bronchial severity and pulmonary function. CHI3L1 proteins are involved in both innate and adaptive immune responses; however, to date, the correlation of these SNPs and their age of onset of bronchial asthma has not been demonstrated. Methods To address the role of these genetic variations, 390 patients with well-controlled bronchial asthma and living in Japan were recruited, genotyped, and had a pulmonary function test performed on them in this study. To analyze the concentration levels of CHI3L1 protein, bronchial lavage fluids were examined. Results Forced expiratory volume in one second, %predicted (%FEV1), was significantly decreased in homozygotes of rs1214194 compared to heterozygotes and wild type. The age of onset of adult bronchial asthma was significantly younger in GG homozygotes of rs4950928 and AA homozygotes of rs1214194 than in the other two genotypes. The concentration of CHI3L1 protein in bronchial lavage fluid increased in both homozygotes of rs4950928 and rs1214194. Conclusions Our study demonstrated that the homozygotes of rs4950928 and rs1214194 of CHI3L1 might predict an early onset of bronchial asthma and have the propensity to promote airway remodeling. Trial registration JMA-IIA00045 remodeling-ICS

Abstract Background YKL-40 (also known as Chitinase 3-like 1) is a glycoprotein produced by inflammatory, cancer and stem cells. Its physiological role is not completely understood but YKL-40 is elevated in the brain and cerebrospinal fluid (CSF) in several neurological and neurodegenerative diseases associated with inflammatory processes. Yet the precise characterization of YKL-40 in dementia cases is missing. Methods In the present study, we comparatively analysed YKL-40 levels in the brain and CSF samples from neurodegenerative dementias of different aetiologies characterized by the presence of cortical pathology and disease-specific neuroinflammatory signatures. Results YKL-40 was normally expressed in fibrillar astrocytes in the white matter. Additionally YKL-40 was highly and widely expressed in reactive protoplasmic cortical and perivascular astrocytes, and fibrillar astrocytes in sporadic Creutzfeldt-Jakob disease (sCJD). Elevated YKL-40 levels were also detected in Alzheimer’s disease (AD) but not in dementia with Lewy bodies (DLB). In AD, YKL-40-positive astrocytes were commonly found in clusters, often around β-amyloid plaques, and surrounding vessels with β-amyloid angiopathy; they were also distributed randomly in the cerebral cortex and white matter. YKL-40 overexpression appeared as a pre-clinical event as demonstrated in experimental models of prion diseases and AD pathology. CSF YKL-40 levels were measured in a cohort of 288 individuals, including neurological controls (NC) and patients diagnosed with different types of dementia. Compared to NC, increased YKL-40 levels were detected in sCJD (p 0.05, AUC = 0.71) or in DLB/Parkinson’s disease dementia (PDD) (p > 0.05, AUC = 0.70). Further, two independent patient cohorts were used to validate the increased CSF YKL-40 levels in sCJD. Additionally, increased YKL-40 levels were found in genetic prion diseases associated with the PRNP-D178N (Fatal Familial Insomnia) and PRNP-E200K mutations. Conclusions Our results unequivocally demonstrate that in neurodegenerative dementias, YKL-40 is a disease-specific marker of neuroinflammation showing its highest levels in prion diseases. Therefore, YKL-40 quantification might have a potential for application in the evaluation of therapeutic intervention in dementias with a neuroinflammatory component.

Autoimmunity to chitinase 3-like 1 (CHI3L1) has recently been reported in hepatic and bowel inflammatory conditions. Considering that CHI3L1 plays a role as prognostic biomarker in multiple sclerosis (MS), here we investigated CHI3L1 as potential autoantigenic target in the disease. We determined serum CHI3L1 autoantibodies by enzyme-linked immunosorbent assay (ELISA) in a cohort of 60 untreated MS patients with different clinical forms of the disease and 20 healthy controls (HC). IgG levels to CHI3L1 were similar between patients with relapsing-remitting MS, primary and secondary progressive MS, and HC. These findings do not support a role for CHI3L1 autoantibodies in MS pathogenesis. [ABSTRACT FROM AUTHOR]

Aim: Chitinase 3‐like 1 (CHI3L1), an 18‐glycosyl hydrolase‐related molecule, is a member of the enzymatically inactive chitinase‐like protein family. Serum levels of CHI3L1 are strongly correlated with hepatic fibrosis progression during many liver diseases. Therefore, this protein could be involved in the development of hepatic fibrosis pathology; however, its role has not been elucidated. We aimed to elucidate its role in the pathophysiology of liver fibrosis. Methods: Chitinase 3‐like 1‐deficient (Chi3l1−/−) mice were given carbon tetrachloride twice per week for 4 weeks or fed a methionine choline‐deficient diet for 12 weeks to generate mouse liver fibrosis models. Human fibrotic liver tissues were also examined immunohistochemically. Results: In human and mouse fibrotic livers, CHI3L1 expression was mainly localized to hepatic macrophages, and the intrahepatic accumulation of CHI3L1+ macrophages was significantly enhanced compared to that in control livers. In the two mouse models, hepatic fibrosis was significantly ameliorated in Chi3l1−/− mice compared to that in wild‐type mice, which was dependent on hepatic macrophages. The accumulation and activation of hepatic macrophages was also significantly suppressed in Chi3l1−/− mice compared to that in wild‐type mice. Furthermore, apoptotic hepatic macrophages were significantly increased in Chi3l1−/− mice. Chitinase 3‐like 1 was found to inhibit hepatic macrophage apoptosis by suppressing Fas expression and activating Akt signaling in an autocrine manner, which resulted in hepatic macrophage accumulation and activation, exaggerating liver fibrosis. Conclusions: Chitinase 3‐like 1 exacerbates liver fibrosis progression by suppressing apoptosis in hepatic macrophages. Therefore, this might be a potential therapeutic target for the treatment of liver fibrosis. [ABSTRACT FROM AUTHOR]

Background: Atopic dermatitis (AD) is a chronic inflammatory skin disorder characterized by defective skin barrier and Th2 immune responses. Chitinase 3‐like 1 (CHI3L1), also known as breast regression protein 39 (BRP‐39) in mice and human homologue YKL‐40, plays important roles in Th2 inflammation and allergen sensitization. CHI3L1 has been implicated in a variety of diseases including asthma characterized by inflammation, apoptosis and tissue remodelling, but its role in AD remains elusive. Objective: The aim of this study was to investigate the role of CHI3L1 in the development and progression of AD. Results: We investigated YKL‐40 levels in the serum and skin of AD patients by ELISA and immunofluorescence, respectively. Using a murine model of AD induced by ovalbumin (OVA), we investigated Th2 immune responses, M2 macrophage activation and skin barrier gene expression using wild‐type (WT) and BRP‐39 null mutant (BRP‐39−/−) mice. YKL‐40 level was significantly increased in serum of AD patients. In addition, both mRNA and protein expression levels of BRP‐39 were higher in OVA‐sensitized WT mice than in control mice. OVA‐sensitized BRP‐39−/− mice showed decreased epidermal thickness, lower total serum IgE, Th2 cytokine levels and CD4+ effector T cell populations than OVA‐sensitized WT mice. Induction of BRP‐39 was dominant in dermal macrophages. BRP‐39 deficiency was found to be involved in M2 macrophage activation. Consistently, the YKL‐40 level in the skin of AD patients was higher than in normal subjects and it was expressed in dermal macrophages. BRP‐39 deficiency attenuated dysregulation of skin barrier and tight junction genes. Conclusions and Clinical Relevance: These findings demonstrate that CHI3L1 mediates the development of AD induced by OVA, affecting Th2 inflammation, M2 macrophage activation and skin barrier function. [ABSTRACT FROM AUTHOR]

Inflammatory bowel disease (IBD) is a dysregulated inflammatory condition induced by multiple factors. The etiology of IBD is largely unknown, and the disease progression and prognosis are variable and unpredictable with uncontrolled disease behavior. Monitoring the status of chronic colitis closely is challenging for physicians, because the assessment of disease activity and severity require invasive methods. Using laboratory biomarkers may provide a useful alternative to invasive methods in the diagnosis and management of IBD. Furthermore, patients with ulcerative colitis or Crohn’s disease are also at risk of developing cancer. Annual colonoscopies can help lower the risk for developing colorectal cancer. However, laboratory biomarkers may also be helpful as non-invasive indicators in predicting treatment responses, improving prognosis, and predicting possible tumors. This review addresses selected laboratory biomarkers (including ANCA, chitinase 3-like 1, S100A12/RAGE, calprotectin, and TNF/TNFR2), which are identified by utilizing two well-accepted animal models of colitis, dextran sodium sulfate-induced and T cell receptor alpha knockout colitis models. In addition to being useful for monitoring disease severity, these biomarkers are associated with therapeutic strategies. The factors may regulate the initiation and perpetuation of inflammatory factors in the gut.

RSV infection increased R L and respiratory inflammation in mice, including of CHI3L1 expression and phosphorylation of ERK1/2 and AKT, as well as the expression of markers (CD80, CD86, MHCII, OX40L). In RSV-infected mice with the silence of CHI3L1, R L and airway inflammation were attenuated, as did the phosphorylation levels of ERK1/2 and AKT and the expression of CD86 and OX40L. Frequencies of Th2 and Th17 cells, and the expression levels of their representative cytokines were decreased. Conversely, the proportion of Treg cells and IL-10 expression were increased. These were also verified by BMDCs and its supernatant in vitro. [Display omitted] • Dendritic cells (DCs) contribute to immune imbalance and airway hyperresponsiveness (AHR) induced by respiratory syncytial virus (RSV). RSV elevated CHI3L1 expression in lung DCs and bone marrow-derived dendritic cells (BMDCs). • Knockdown of CHI3L1 impeded RSV induced activation of MAPK/ERK and PI3K/AKT signaling pathways, reduced the proportion of Th2 and Th17 cells, and increased the proportion of Treg cells. • CHI3L1 promotes RSV induced immune imbalance and airway hyperresponsiveness by regulating the functional transformation of DCs. By blocking CHI3L1, RSV-infected mice shown relief of airway resistance, the downregulation of Th2/Th17 levels, and the upregulation of IL-10. Dendritic cells (DCs) contribute to immune imbalance and airway hyperresponsiveness (AHR) induced by respiratory syncytial virus (RSV). The aim of present study was to explore the mechanism of RSV regulating naive T cell differentiation through DCs. We generated a Lentivirus shRNA expression vector to knock down CHI3L1 in mouse lungs and bone marrow-derived dendritic cells (BMDCs). Then we investigated the effect of CHI3L1 knockdown on MAPK/ERK pathway, PI3K/AKT pathway, mature DCs represented by molecular markers, naive T cell differentiation and related cytokine expression in vitro and in vivo models of RSV. RSV elevated CHI3L1 expression in lung DCs and BMDCs. Knockdown of CHI3L1 impeded RSV-induced activation of MAPK/ERK and PI3K/AKT signaling pathways, attenuated CD86 and OX40L expression in mature DCs, reduced the proportion of Th2 and Th17 cells, and increased the proportion of Treg cells. In addition, by blocking CHI3L1, RSV-infected mice shown relief of airway resistance, the downregulation of Th2/Th17 like cytokines IL-4, IL-13 and IL-17 levels, and the upregulation of IL-10. Our data show that CHI3L1 promotes RSV induced immune imbalance and airway hyperresponsiveness by regulating the functional transformation of DCs. [ABSTRACT FROM AUTHOR]

Background/Aims: The chitinase 3-like 1 (CHI3L1) has an important role in cancer progression, and high CHI3L1 expression is associated with the development and progression of cancers. Previous studies had been controversial with respect to the association between CHI3L1 expression and lung cancer prognosis. Thus, we performed a meta-analysis to investigate the prognostic value of CHI3L1 expression in lung cancer. Methods: We searched Pubmed, Embase, and Wanfang databases to identify eligible studies. Overall survival and disease free survival were collected from included studies. Pooled hazard ratios (HRs) with 95% confidence interval (95%CI) were calculated to estimate the association. Seven studies comprising 911 lung cancer patients were included in this meta-analysis. Results: The results showed high CHI3L1 expression was independently associated with poorer overall survival in lung cancer patients (HR = 1.71, 95%CI 1.24-2.37, P = 0.001). Subgroup analysis by histological type showed that high CHI3L1 expression was independently associated with poorer overall survival in both non small-cell lung cancer patients (HR = 2.23,95%CI 1.43-3.47, P Conclusion: Our results suggest that elevated serum CHI3L1 concentration is an independent prognostic biomarker for poorer survival in lung cancer patients.

Chitin is a N-acetyl-d-glucosamine biopolymer that can be recognized by chitin-binding proteins. Although mammals lack chitin synthase, they induce proteins responsible for detecting chitin in response to bacterial infections. Our aim was to investigate whether chitinase 3-like 1 (CHI3L1) has a potential role in the innate immunity of the Escherichia coli (E. coli) infected mammary gland. CHI3L1 protein was found to be secreted in whey of naturally coliform-affected quarters compared to whey samples isolated from healthy udders. In addition, gene expression of CHI3L1 was confirmed in udder tissue of cows experimentally infected with a mammary pathogenic E. coli (MPEC) strain. Despite the known anatomical differences, the bovine udders’ innate immune response was mimicked by applying an experimental mouse model using MPEC or non-MPEC isolates. The effect of CHI3L1 expression in the murine mammary gland in response to coliform bacteria was investigated through the use of CHI3L1−/− mice as well as through treatment with either a pan-caspase inhibitor or chitin particles in wild-type mice. The local induction of CHI3L1 postinfection with different E. coli strains was demonstrated to be independent of both bacterial growth and mammary interleukin (IL)-8 levels. Indeed, CHI3L1 emerged as a regulator impacting on the transcytosis of Ly6G-positive cells from the interstitial space into the alveolar lumen of the mammary tissue. Furthermore, CHI3L1 was found to be upstream regulated by caspase activity and had a major downstream effect on the local pro-inflammatory cytokine profile, including IL-1beta, IL-6, and RANTES/CCL5. In conclusion, CHI3L1 was demonstrated to play a key role in the cytokine and caspase signaling during E. coli triggered inflammation of the mammary gland.

Highlights • Chitinase 3-like 1 and neurofilament light chain are increased in pediatric acquired demyelinating syndromes (ADS). • Chitinase 3-like 1 and neurofilament light chain better distinguish between ADS and non-ADS than oligoclonal bands alone. • Chitinase 3-like 1 is increased in ADEM compared with MS. Abstract Background Chitinase 3-like 1 (CHI3L1), neurofilament light chain (NFL) and oligoclonal bands (OCB) in cerebrospinal fluid are associated with central nervous system demyelination in adults. CHI3L1 and OCB are markers of central nervous system inflammation, whereas NFL is a marker of white-matter axonal injury. The aim was to examine whether CHI3L1 and NFL in cerebrospinal fluid are associated with acquired demyelinating syndromes at disease onset in a pediatric population. Methods Children (<18 years) referred to hospital for possible neuroinflammatory disease were retrospectively included from 2010 to 2016. Case ascertainment was by review of medical records. NFL and CHI3L1 were measured by enzyme-linked immunosorbent assays. Endpoints were differences in concentrations of cerebrospinal fluid NFL and CHI3L1. Results We included 193 children who all underwent cerebrospinal fluid OCB examination as part of their diagnostic work-up and classified these children into 5 groups: acquired demyelinating syndromes (n = 33), normal diagnostic work-up (n = 36), inflammatory neurological disease (n = 50), other neurological disease (n = 55), and systemic inflammatory diseases (n = 19). NFL and CHI3L1 in cerebrospinal fluid differed significantly between the five groups (p = 0.0001). CHI3L1 was significantly higher in acquired demyelinating syndromes than in all other groups, and NFL was significantly higher in acquired demyelinating syndromes than in the other groups except systemic inflammatory disease. Children with acute disseminated encephalomyelitis had significantly higher concentrations of CHI3L1 than did children with multiple sclerosis. Conclusion We provide class II evidence that CHI3L1 and NFL are associated with pediatric acquired demyelinating syndromes. CHI3L1 may help distinguishing between acute disseminated encephalomyelitis and multiple sclerosis, but this needs further confirmation. [ABSTRACT FROM AUTHOR]

Chitin is a N-acetyl-d-glucosamine biopolymer that can be recognized by chitin-binding proteins. Although mammals lack chitin synthase, they induce proteins responsible for detecting chitin in response to bacterial infections. Our aim was to investigate whether chitinase 3-like 1 (CHI3L1) has a potential role in the innate immunity of the Escherichia coli (E. coli) infected mammary gland. CHI3L1 protein was found to be secreted in whey of naturally coliform-affected quarters compared to whey samples isolated from healthy udders. In addition, gene expression of CHI3L1 was confirmed in udder tissue of cows experimentally infected with a mammary pathogenic E. coli (MPEC) strain. Despite the known anatomical differences, the bovine udders' innate immune response was mimicked by applying an experimental mouse model using MPEC or non-MPEC isolates. The effect of CHI3L1 expression in the murine mammary gland in response to coliform bacteria was investigated through the use of CHI3L1-/- mice as well as through treatment with either a pan-caspase inhibitor or chitin particles in wild-type mice. The local induction of CHI3L1 postinfection with different E. coli strains was demonstrated to be independent of both bacterial growth and mammary interleukin (IL)-8 levels. Indeed, CHI3L1 emerged as a regulator impacting on the transcytosis of Ly6G-positive cells from the interstitial space into the alveolar lumen of the mammary tissue. Furthermore, CHI3L1 was found to be upstream regulated by caspase activity and had a major downstream effect on the local pro-inflammatory cytokine profile, including IL-1beta, IL-6, and RANTES/CCL5. In conclusion, CHI3L1 was demonstrated to play a key role in the cytokine and caspase signaling during E. coli triggered inflammation of the mammary gland. [ABSTRACT FROM AUTHOR]

Aim: Non‐invasive assessment of changes in liver fibrosis is still an unmet medical need in the era of antiviral therapy. Therefore, we explore whether chitinase 3‐like 1 (CHI3L1), a serum marker of liver fibrosis, can be used as a non‐invasive surrogate marker of fibrosis change during treatment. Methods: We correlated serum CHI3L1 levels with liver tissue collagen proportionate area (CPA) in a cohort of 131 patients with chronic hepatitis B (CHB) receiving entecavir‐based antiviral therapy for 78 weeks. In addition, we compared this marker with the liver stiffness measurement (LSM). Multivariate regression analyses were undertaken to determine the clinical factors associated with the CHI3L1 levels. Results: Before treatment, correlation analysis showed that there were positive correlations between CHI3L1 levels and the CPA (r = 0.351, P < 0.001), and between CHI3L1 and LSM (r = 0.412, P < 0.001). After 78 weeks treatment, serum CHI3L1 levels decreased compared with that at baseline (87.8 vs. 69.6 ng/mL, P < 0.001), and CHI3L1 levels were also correlated with CPA (r = 0.293, P = 0.001) and LSM (r = 0.443, P < 0.001). Furthermore, there were positive correlations between the changes in CHI3L1 and CPA (r = 0.366, P<0.001), and changes in CHI3L1 and LSM (r = 0.438, P<0.001). Multivariate regression analyses indicated that CPA values were related with pre‐ (β = 5.450, P = 0.019) and post‐treatment CHI3L1 levels (β = 7.460, P = 0.023). Conclusions: Chitinase 3‐like 1 is not only a useful non­invasive marker for the assessment of liver fibrosis in CHB patients before treatment, but also a potential useful marker for monitoring the change in liver fibrosis during therapy. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is one of the most causative agents of mastitis and is associated with chronic udder infections. The persistency of the pathogen is believed to be the result of an insufficient triggering of local inflammatory signaling. In this study, the preclinical mastitis model was used, aiming to evaluate if lipopolysaccharide (LPS) or lipoteichoic acid (LTA) preconditioning could aid the host in more effectively clearing or at least limiting a subsequent S. aureus infection. A prototypic Gram-negative virulence factor, i.e., LPS and Gram-positive virulence factor, i.e., LTA were screened whether they were able to boost the local immune compartment. Compared to S. aureus-induced inflammation, both toxins had a remarkable high potency to efficiently induce two novel selected innate immunity biomarkers i.e., lipocalin 2 (LCN2) and chitinase 3-like 1 (CHI3L1). When combining mammary inoculation of LPS or LTA prior to a local S. aureus infection, we were able to modulate the innate immune response, reduce local bacterial loads, and induce either LCN2 or CHI3L1 at 24 h post-infection. Clodronate depletion of mammary macrophages also identified that macrophages contribute only to a limited extend to the LPS/LTA-induced immunomodulation upon S. aureus infection. Based on histological neutrophil influx evaluation, concomitant local cytokine profiles and LCN2/CHI3L1 patterns, the macrophage-independent signaling plays a major role in the LPS- or LTA-pretreated S. aureus-infected mouse mammary gland. Our results highlight the importance of a vigilant microenvironment during the innate immune response of the mammary gland and offer novel insights for new approaches concerning effective immunomodulation against a local bacterial infection.

Background: YKL-40 (also known as Chitinase 3-like 1) is a glycoprotein produced by inflammatory, cancer and stem cells. Its physiological role is not completely understood but YKL-40 is elevated in the brain and cerebrospinal fluid (CSF) in several neurological and neurodegenerative diseases associated with inflammatory processes. Yet the precise characterization of YKL-40 in dementia cases is missing. Methods: In the present study, we comparatively analysed YKL-40 levels in the brain and CSF samples from neurodegenerative dementias of different aetiologies characterized by the presence of cortical pathology and disease-specific neuroinflammatory signatures. Results: YKL-40 was normally expressed in fibrillar astrocytes in the white matter. Additionally YKL-40 was highly and widely expressed in reactive protoplasmic cortical and perivascular astrocytes, and fibrillar astrocytes in sporadic Creutzfeldt-Jakob disease (sCJD). Elevated YKL-40 levels were also detected in Alzheimer's disease (AD) but not in dementia with Lewy bodies (DLB). In AD, YKL-40-positive astrocytes were commonly found in clusters, often around β-amyloid plaques, and surrounding vessels with β-amyloid angiopathy; they were also distributed randomly in the cerebral cortex and white matter. YKL-40 overexpression appeared as a pre-clinical event as demonstrated in experimental models of prion diseases and AD pathology. CSF YKL-40 levels were measured in a cohort of 288 individuals, including neurological controls (NC) and patients diagnosed with different types of dementia. Compared to NC, increased YKL-40 levels were detected in sCJD (p < 0.001, AUC = 0.92) and AD (p < 0.001, AUC = 0.77) but not in vascular dementia (VaD) (p > 0.05, AUC = 0.71) or in DLB/Parkinson's disease dementia (PDD) (p > 0.05, AUC = 0.70). Further, two independent patient cohorts were used to validate the increased CSF YKL-40 levels in sCJD. Additionally, increased YKL-40 levels were found in genetic prion diseases associated with the PRNP-D178N (Fatal Familial Insomnia) and PRNP-E200K mutations. Conclusions: Our results unequivocally demonstrate that in neurodegenerative dementias, YKL-40 is a disease-specific marker of neuroinflammation showing its highest levels in prion diseases. Therefore, YKL-40 quantification might have a potential for application in the evaluation of therapeutic intervention in dementias with a neuroinflammatory component. [ABSTRACT FROM AUTHOR]

Staphylococcus aureus is one of the most causative agents of mastitis and is associated with chronic udder infections. The persistency of the pathogen is believed to be the result of an insufficient triggering of local inflammatory signaling. In this study, the preclinical mastitis model was used, aiming to evaluate if lipopolysaccharide (LPS) or lipoteichoic acid (LTA) preconditioning could aid the host in more effectively clearing or at least limiting a subsequent S. aureus infection. A prototypic Gram-negative virulence factor, i.e., LPS and Gram-positive virulence factor, i.e., LTA were screened whether they were able to boost the local immune compartment. Compared to S. aureusinduced inflammation, both toxins had a remarkable high potency to efficiently induce two novel selected innate immunity biomarkers i.e., lipocalin 2 (LCN2) and chitinase 3-like 1 (CHI3L1). When combining mammary inoculation of LPS or LTA prior to a local S. aureus infection, we were able to modulate the innate immune response, reduce local bacterial loads, and induce either LCN2 or CHI3L1 at 24 h post-infection. Clodronate depletion of mammary macrophages also identified that macrophages contribute only to a limited extend to the LPS/LTA-induced immunomodulation upon S. aureus infection. Based on histological neutrophil influx evaluation, concomitant local cytokine profiles and LCN2/CHI3L1 patterns, the macrophage-independent signaling plays a major role in the LPS- or LTA-pretreated S. aureus-infected mouse mammary gland. Our results highlight the importance of a vigilant microenvironment during the innate immune response of the mammary gland and offer novel insights for new approaches concerning effective immunomodulation against a local bacterial infection. [ABSTRACT FROM AUTHOR]

Chitinase 3-like 1 (CHI3L1) plays a prognostic role in patients with multiple sclerosis (MS). Here, we investigated a potential association between CHI3L1 and the response to interferon-beta (IFNβ) and glatiramer acetate (GA). Serum CHI3L1 levels were measured by ELISA in 117 relapsing-remitting MS (RRMS) patients, 76 IFNβ-treated and 41 GA-treated patients. CHI3L1 levels were increased by GA ( p = 0.014) but unchanged by IFNβ ( p = 0.830). CHI3L1 was associated with IFNβ response and levels were higher in non-responder group ( p = 0.020), while GA showed no responder effect ( p = 0.943). These results suggest a role for CHI3L1 as response biomarker to IFNβ in RRMS patients. [ABSTRACT FROM AUTHOR]

Aim: To evaluate the potential of two trabecular meshwork (TM)-specific promoters, Chitinase 3-like 1 (Ch3L1) and matrix gla protein (MGP), for improving specificity and safety in glaucoma gene therapy based on self-complementary AAV2 (scAAV2) vector technologies., Methods: An scAAV2 vector with C3 transferase (C3) as the reporter gene (scAAV2-C3) was selected. The scAAV2-C3 vectors were driven by Ch3L1 (scAAV2-Ch3L1-C3), MGP (scAAV2-MGP-C3), enhanced MGP (scAAV2-eMGP-C3) and cytomegalovirus (scAAV2-CMV-C3), respectively. The cultured primary human TM cells were treated with each vector at different multiplicities of infections. Changes in cell morphology were observed by phase contrast microscopy. Actin stress fibers and Rho GTPases/Rho-associated protein kinase pathway-related molecules were assessed by immunofluorescence staining, real-time quantitative polymerase chain reaction and Western blot. Each vector was injected intracamerally into the one eye of each rat at low and high doses respectively. In vivo green fluorescence was visualized by a Micron III Retinal Imaging Microscope. Intraocular pressure (IOP) was monitored using a rebound tonometer. Ocular responses were evaluated by slit-lamp microscopy. Ocular histopathology analysis was examined by hematoxylin and eosin staining., Results: In TM cell culture studies, the vector-mediated C3 expression induced morphologic changes, disruption of actin cytoskeleton and reduction of fibronectin expression in TM cells by inhibiting the Rho GTPases/Rho-associated protein kinase signaling pathway. At the same dose, these changes were significant in TM cells treated with scAAV2-CMV-C3 or scAAV2-Ch3L1-C3, but not in cells treated with scAAV2-eMGP-C3 or scAAV2-MGP-C3. At low-injected dose, the IOP was significantly decreased in the scAAV2-Ch3L1-C3-injected eyes but not in scAAV2-MGP-C3-injected and scAAV2-eMGP-C3-injected eyes. At high-injected dose, significant IOP reduction was observed in the scAAV2-eMGP-C3-injected eyes but not in scAAV2-MGP-C3-injected eyes. Similar to scAAV2-CMV-C3, scAAV2-Ch3L1-C3 vector showed efficient transduction both in the TM and corneal endothelium. In anterior segment tissues of scAAV2-eMGP-C3-injected eyes, no obvious morphological changes were found except for the TM. Inflammation was absent., Conclusion: In scAAV2-transduced TM cells, the promoter-driven efficiency of Ch3L1 is close to that of cytomegalovirus, but obviously higher than that of MGP. In the anterior chamber of rat eye, the transgene expression pattern of scAAV2 vector is presumably affected by MGP promoter, but not by Ch3L1 promoter. These findings would provide a useful reference for improvement of specificity and safety in glaucoma gene therapy using scAAV2 vector., (International Journal of Ophthalmology Press.)

Background: The current gold standard non-invasive test for detecting pre-cancerous changes is the faecal immunochemical test (FIT). However, this test can lack sensitivity and specificity and testing for another biomarker may address these limitations. Chitinase 3-like 1 (CHI3L1) is emerging as a potential biomarker of inflammation-associated carcinogenic changes in epithelial cells.  In this study CHI3L1 levels were analysed in patients and controls to determine their ability to improve detection of early CRC either alone or in combination with a FIT., Methods: CHI3L1 levels were measured by ELISA in serum and stool samples from cohorts of CRC and healthy donors as well as stool samples from a cohort of symptomatic primary care patients. Faecal haemoglobin was also analysed in the same primary care samples using FIT., Results: CHI3L1 levels were a good discriminatory marker of CRC, with no significant difference between levels detected in the stool and serum samples.  ROC curves that determined the optimal cut-point however identified that stool samples gave higher sensitivity (83% versus 69%) and specificity (89% versus 74%) than matched serum samples. Faecal CHI3L1 levels in the primary care patients were not significantly different (p=0.193) from those detected in the healthy controls. ROC curve analysis confirmed that faecal CHI3L1 levels had limited ability to discriminate between patients who did or didn't have evidence of lesions (AUC=0.52, p=0.74). Similarly, CHI3L1 levels did not reliably identify those symptomatic primary care patients who subsequently presented with early-stage disease (polyps and adenomas) or CRC. The discriminatory power of FIT was not increased by incorporating the CHI3L1 results in this setting., Conclusion: There was no evidence that measurement of faecal CHI3L1 has the potential to increase diagnostic accuracy, either alone or in combination with a FIT, in symptomatic primary care patients.

Caffeine (1,3,7-trimethylxanthine, also abbreviated to CAF) is a natural chemical with stimulant effects and is commonly included in many drinks and foods, including coffee, tea, cola, energy drinks, cocoa, chocolates, and so on. Our group previously reported that oral administration of CAF efficiently suppressed the development of intestinal inflammation in a dextran sulfate sodium (DSS)-induced murine acute colitis model by suppressing the expression of chitinase 3-like 1, one of the mammalian chitinases without enzymatic activity. Chitinases are hydrolytic enzymes that break down chitin, a polymer of N-acetylglucosamine, and chitinase-like proteins have no enzymatic activity with preserving chitin-binding ability. CAF binds a cleft of the chitinase active site and plays a role as a pan-chitinase inhibitor. Although CAF showed an anti-inflammatory effect in the above model, oral administration of low-dose CAF with 10% sucrose showed potentially neoplastic effects in colonic epithelial cells in a DSS-induced murine chronic colitis model. In this review, we would like to discuss the pros and cons of coffee/CAF in colonic inflammation and neoplasia with an example of pathological finding.

Breast tumorigenesis is classically studied in mice by inoculating tumor cells in the fat pad, the adipose compartment of the mammary gland. Alternatively, the mammary ducts, which constitute the luminal mammary gland compartment, also provide a suitable inoculation site to induce breast cancer in murine models. The microenvironments in these compartments influence tumor cell progression, yet this effect has not been investigated in an immunocompetent context. Here, we compared both mammary gland compartments as distinct inoculation sites, taking into account the immunological aspect by inoculating 4T1 tumor cells in immunocompetent mice. Following tumor cell inoculation in the adipose compartment of non-pretreated/naive, hormonally pretreated/naive and non-pretreated/lactating mice, the primary tumors developed similarly. However, a slower onset of primary tumor growth was found after inoculations in the luminal compartment of non-pretreated/lactating mice. Despite this difference in tumor development rate, metastasis to the liver and lungs was equally observed and was accompanied by lymphatic spreading of tumor cells and progressive splenomegaly with both inoculation types. Chitinase 3-like 1 (CHI3L1) and lipocalin 2 (LCN2) served as innovative biomarkers for disease progression showing increased levels in primary tumors and sera of the non-pretreated/lactating inoculation groups. A slower increase in circulating CHI3L1 but not LCN2 levels, was observed after inoculations in the luminal compartment which corroborated the slower tumor development at this inoculation site. Our results highlight the critical impact of different mammary gland compartments on tumor development in syngeneic murine models and support the use of novel tumor progression biomarkers in an immune-competent environment. [ABSTRACT FROM AUTHOR]

Background: Survival of glioma patients with the same tumor histology and grade can vary significantly, and some low-grade gliomas transform to a more malignant phenotype. There is a need of molecular signatures, which are better predictors of the patient diagnosis, outcome of treatment, and prognosis than the diagnosis provided by histopathology. We propose CHI3L1 mRNA expression as a prognostic biomarker for patients with glioma. Methods: We measured CHI3L1 expression with quantitative real time-polymerase chain reaction (qRT-PCR) in the cohort of 98 patients with different grade glioma: 10 grade I pylocytic astrocytomas, 30 grade II diffuse astrocytomas, 20 grade III anaplastic astrocytomas, and 38 grade IV astrocytomas (glioblastomas). Statistical analyses were conducted to investigate the association between CHI3L1 mRNA expression levels and patient clinical variables. Results: We demonstrated that mRNA expression of CHI3L1 was evidently higher in glioblastoma than in lower grade glioma tissues. We evaluated correlations between CHI3L1 expression, clinicopathological characteristics, and the outcomes of the patients. Patients with high CHI3L1 expression had a shorter overall survival (p < 0.001). Conclusions: Findings presented in our study showed that increased mRNA level of CHI3L1 could be associated with the progression of astrocytoma and poor patient survival not only for glioblastoma, but for lower grade astrocytoma tumors as well. Further investigation will be required to evaluate CHI3L1 value as a molecular marker for astrocytoma prognoses and for novel treatment strategies against all grade astrocytomas. [ABSTRACT FROM AUTHOR]

Background/Aims: The chitinase 3-like 1 (CHI3L1) has an important role in cancer progression, and high CHI3L1 expression is associated with the development and progression of cancers. Previous studies had been controversial with respect to the association between CHI3L1 expression and lung cancer prognosis. Thus, we performed a meta-analysis to investigate the prognostic value of CHI3L1 expression in lung cancer. Methods: We searched Pubmed, Embase, and Wanfang databases to identify eligible studies. Overall survival and disease free survival were collected from included studies. Pooled hazard ratios (HRs) with 95% confidence interval (95%CI) were calculated to estimate the association. Seven studies comprising 911 lung cancer patients were included in this meta-analysis. Results: The results showed high CHI3L1 expression was independently associated with poorer overall survival in lung cancer patients (HR = 1.71, 95%CI 1.24-2.37, P = 0.001). Subgroup analysis by histological type showed that high CHI3L1 expression was independently associated with poorer overall survival in both non small-cell lung cancer patients (HR = 2.23,95%CI 1.43-3.47, P < 0.001) and small-cell lung cancer patients (HR = 1.45, 95%CI 1.06-2.00, P = 0.021). In addition, sensitivity analysis by omitting single study by turns did not change the pooled outcomes obviously. Conclusion: Our results suggest that elevated serum CHI3L1 concentration is an independent prognostic biomarker for poorer survival in lung cancer patients. © 2016 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]

Background and purpose: Chitinase 3‐like 1 (CHI3L1) and neurofilament light chain (NF‐L) are promising biomarkers of disability in multiple sclerosis (MS). However, their role in cognitive dysfunction remains elusive. Here, we aimed to correlate cerebrospinal fluid (CSF) levels of CHI3L1 and NF‐L with cognitive status in MS. Methods: Fifty one recently diagnosed patients were cognitively evaluated and CSF was collected. Levels of CHI3L1 and NF‐L were determined by ELISA. Spearman's partial correlation coefficient was performed. Results: After adjusting cognitive scores by age, anxiety and EDSS, association was detected between CHI3L1 levels and Trail Making Test A (rs = 0.348; p = 0.016) and between NF‐L levels and Word List Generation (rs = −0.324; p = 0.025). Conclusion: High levels of CSF CHI3L1 and NF‐L are associated with cognitive impairment in the early phases of MS. [ABSTRACT FROM AUTHOR]

Objective: Anti-leucine-rich glioma inactivated 1(LGI1) encephalitis is one rare autoimmune encephalitis which is accompanied by inflammatory responses. (Anti-leucine-rich glioma inactivated 1 (anti-LGI1) encephalitis is an autoimmune disease mediated by inflammatory responses.)This study aimed to investigate the Chitinase 3-like 1(CHI3L1) in anti-LGI1encephalitis patients and evaluate its association with modified Rankin Scale (mRS) score in anti-LGI1 encephalitis at admission and 6 months follow-up.(This study looked into the relationship between Chitinase 3-like 1 (CHI3L1) and the modified Ranking Scale (mRS) score in anti-LGI1 encephalitis patients at admission and 6 months later.)., Methods: Thirty-five patients with anti-LGI1 encephalitis and 22 patients with non-inflammatory neurological disease were enrolled in this study. (We enrolled 35 patients with anti-LGI1 encephalitis and 22 patients with non-inflammatory neurological disease.)Cerebrospinal fluid (CSF) and serum levels of CHI3L1 were measured by enzyme-linked immunosorbent assay. (We quantified CHI3L1 in the serum and cerebrospinal fluid (CSF) by performing an enzyme-linked immunosorbent assay.)Patients were evaluated for mRS score at admission and at 6 months follow-up.(We recorded the mRS score of the patients at admission and 6 months later.)., Results: CHI3L1 levels in CSF and serum were highly elevated in patients with anti-LGI1 encephalitis at admission compared those with the controls.(At admission, patients with anti-LGI1 encephalitis had elevated CHI3L1 levels in the CSF and serum.) Additionally, patients presenting with cognitive impairment had significantly higher CSF CHI3L1 levels and mRS scores than those without cognitive impairment symptoms. Patients presenting with only faciobrachial dystonic seizures at admission had lower CSF CHI3L1 levels than those with other symptoms. Finally, CSF CHI3L1 levels were positively correlated with CSF lactate levels., Conclusion: CHI3L1 level in CSF is correlated with the severity and prognosis of anti-LGI1 encephalitis. (CSF CHI3L1 levels are correlated with the severity and prognosis of anti-LGI1 encephalitis.)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Li, Li, Wang, Zhao, Wang and Li.)