CHI3L1 nuclear localization in monocyte derived dendritic cells. Immunobiology. 2016;221:347-356. [PMID: 26466985 DOI: 10.1016/j.imbio.2015.09.023]

Single-cell profile reveals the landscape of cardiac immunity and identifies a cardio-protective Ym-1hi neutrophil in myocardial ischemia-reperfusion injury

Myocardial ischemia-reperfusion injury (MIRI) is a major hindrance to the success of cardiac reperfusion therapy. Although increased neutrophil infiltration is a hallmark of MIRI, the subtypes and alterations of neutrophils in this process remain unclear. Here, we performed single-cell sequencing of cardiac CD45+ cells isolated from the murine myocardium subjected to MIRI at six-time points. We identified diverse types of infiltrating immune cells and their dynamic changes during MIRI. Cardiac neutrophils showed the most immediate response and largest changes and featured with functionally heterogeneous subpopulations, including Ccl3hi Neu and Ym-1hi Neu, which were increased at 6 h and 1 d after reperfusion, respectively. Ym-1hi Neu selectively expressed genes with protective effects and was, therefore, identified as a novel specific type of cardiac cell in the injured heart. Further analysis indicated that neutrophils and their subtypes orchestrated subsequent immune responses in the cardiac tissues, especially instructing the response of macrophages. The abundance of Ym-1hi Neu was closely correlated with the therapeutic efficacy of MIRI when neutrophils were specifically targeted by anti-Lymphocyte antigen 6 complex locus G6D (Ly6G) or anti-Intercellular cell adhesion molecule-1 (ICAM-1) neutralizing antibodies. In addition, a neutrophil subtype with the same phenotype as Ym-1hi Neu was detected in clinical samples and correlated with prognosis. Ym-1 inhibition exacerbated myocardial injury, whereas Ym-1 supplementation significantly ameliorated injury in MIRI mice, which was attributed to the tilt of Ym-1 on the polarization of macrophages toward the repair phenotype in myocardial tissue. Overall, our findings reveal the anti-inflammatory phenotype of Ym-1hi Neu and highlight its critical role in myocardial protection during the early stages of MIRI.

Chitinase 3-like 1 plays a pivotal role in airway response of RSV infection via regulating DC functional transition

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Our data show that CHI3L1 promotes RSV induced immune imbalance and airway hyperresponsiveness by regulating the functional transformation of DCs.

[YKL-40 Promotes the Expression of Inflammatory Factors in Type Ⅱ Alveolar Epithelial Cell Model of A549 Cell Line]

Objective

YKL-40, also known as chitinase-3-like-1 (CHI3L1), is a human cartilage glycoprotein-39, with its N-terminus consisting of tyrosine (Y), lysine (K), and leucine (L), hence the name YKL-40. In this study, we explored whether YKL-40 could promote the expression of inflammatory factors in type Ⅱ alveolar epithelial cells.

Methods

A549 cells were cultured in vitro with interleukin (IL)-1β (20 ng/mL), IL-6 (20 ng/mL), tumor necrosis factor-alpha (TNF-α) (20 ng/mL), and interferon-gamma (IFN-γ) (20 ng/mL). The expression of YKL-40 transcription was determined by RT-qPCR. A549 cells were cultured with IL-1β at 5, 10, and 20 ng/mL and the expression of YKL-40 protein was determined by Western blot. A549 cells were cultured with recombinant YKL-40 protein at 0, 100, 500, and 1 000 ng/mL and the expression levels of IL-6 and IL-8 were measured by RT-qPCR. Three pairs of small interfering RNAs targeting YKL-40 (si- YKL-40-1/2/3) and the negative control (NC) were designed and used to transfect A549 cells, respectively, and the expression of YKL-40 was determined by RT-qPCR and Western blot. si- YKL-40-3 was screened out for subsequent experiments. In A549 cells, si- YKL-40-3 and si-NC were transfected and, then, IL-1β (20 ng/mL) was added in for culturing. The expression of YKL-40, IL-6, and IL-8 was determined by RT-qPCR and the expression of multiple factors in the supernatant was measured with the QAH-INF-1 kit.

Results

RT-qPCR results showed that IL-1β could up-regulate YKL-40 protein transcription level compared with that of the control group and the difference was statistically significant ( P<0.01), but IL-6, TNF-α, and IFN-γ could not up-regulate YKL-40 protein transcription level. Western blot results showed that IL-1β (20 ng/mL) could significantly promote the expression of YKL-40 and, compared with that of the control group, the differences showed by groups treated with different concentrations of IL-1β were all statistical significant ( P<0.01). After adding human recombinant YKL-40 protein to A549 cells, the results showed that the expression of inflammatory factors IL-6 and IL-8 was significantly increased and the difference was statistically significant compared with that of the control group ( P<0.05). After the expression of YKL-40 was decreased by si- YKL-40-3 transfection, the expression of IL-6 ( P<0.05), IL-8 ( P<0.05), and other inflammatory factors was inhibited compared with that of the control group.

Conclusion

YKL-40 can promote the expression and secretion of IL-6, IL-8, and other acute inflammatory factors in A549 cell line, a type Ⅱ alveolar epithelial cell model, thus aggravating the inflammatory response. Targeted inhibition of YKL-40 expression may effectively inhibit inflammatory response.

Potential role of chitinase-3-like protein 1 (CHI3L1/YKL-40) in neurodegeneration and Alzheimer's disease

Chitinase-3-like protein 1 (CHI3L1/YKL-40) has long been known as a biomarker for early detection of neuroinflammation and disease diagnosis of Alzheimer's disease (AD). In the brain, CHI3L1 is primarily provided by astrocytes and heralds the reactive, neurotoxic state triggered by inflammation and other stress signals. However, how CHI3L1 acts in neuroinflammation or how it contributes to AD and relevant neurodegenerative conditions remains unknown. In peripheral tissues, our group and others have uncovered that CHI3L1 is a master regulator for a wide range of injury and repair events, including the innate immunity pathway that resembles the neuroinflammation process governed by microglia and astrocytes. Based on assessment of current knowledge regarding CHI3L1 biology, we hypothesize that CHI3L1 functions as a signaling molecule mediating distinct neuroinflammatory responses in brain cells and misfunctions to precipitate neurodegeneration. We also recommend future research directions to validate such assertions for better understanding of disease mechanisms.

Sex-dependent neuro-deconvolution analysis of Alzheimer's disease brain transcriptomes according to CHI3L1 expression levels

Glial activation and related neuroinflammatory processes play a key role in the aging and progression of Alzheimer's disease (AD). CHI3L1/ YKL40 is a widely investigated chitinase in neurodegenerative diseases and recent studies have shown its involvement in aging and AD. Nevertheless, the biological function of CHI3L1 in AD is still unknown. Here, we collected microarray datasets from the National Center for Biotechnology Information (NCBI) brain samples of not demented healthy controls (NDHC) who died from causes not attributable to neurodegenerative disorders (n = 460), and of deceased patients suffering from Alzheimer's disease (AD) (n = 697). The NDHC and AD patients were stratified according to CHI3L1 expression levels as a cut-off. We identified two groups both males and females, subsequently used for our statistical comparisons: the high CHI3L1 expression group (HCEG) and the low CHI3L1 expression group (LCEG). Comparing HCEG to LCEG, we attained four signatures according to the sex of patients, in order to identify the healthy and AD brain cellular architecture, performing a genomic deconvolution analysis. We used neurological signatures (NS) belonging to six neurological cells populations and nine signatures that included the main physiological neurological processes. We discovered that, in the brains of NDHC the high expression levels of CHI3L1 were associated with astrocyte activation profile, while in AD males and females we showed an inflammatory profile microglia-mediated. The low CHI3L1 brain expression levels in NDHC and AD patients highlighted a neuronal activation profile. Furthermore, using drugs opposing CHI3L1 transcriptomic signatures, we found a specific drug profile for AD males and females characterized by high levels of CHI3L1 composed of fostamatinib, rucaparib, cephaeline, prednisolone, and dinoprostone. Brain levels of CHI3L1 in AD patients represent a biological signature that allows distinguishing between males and females and their likely cellular brain architecture.

A sex-stratified analysis of neuroimmune gene expression signatures in Alzheimer's disease brains

Alzheimer's disease (AD) is the most common form of progressively disabling dementia. The chitinases CHI3L1 and CHI3L2 have long been known as biomarkers for microglial and astrocytic activation in neurodegeneration. Here, we collected microarray datasets from the National Center for Biotechnology Information (NCBI) brain samples of non-demented controls (NDC) (n = 460), and of deceased patients with AD (n = 697). The AD patients were stratified according to sex. Comparing the high CHI3L1 and CHI3L2 expression group (75^th percentile), and low CHI3L1 and CHI3L2 expression group (25^th percentile), we obtained eight signatures according to the sex of patients and performed a genomic deconvolution analysis using neuroimmune signatures (NIS) belonging to twelve cell populations. Expression analysis revealed significantly higher CHI3L1 and CHI3L2 expression in AD compared with NDC, and positive correlations of these genes with GFAP and TMEM119. Furthermore, deconvolution analysis revealed that CHI3L1 and CHI3L2 high expression was associated with inflammatory signatures in both sexes. Neuronal activation profiles were significantly activated in AD patients with low CHI3L1 and CHI3L2 expression levels. Furthermore, gene ontology analysis of common genes regulated by the two chitinases unveiled immune response as a main biological process. Finally, microglia NIS significantly correlated with CHI3L2 expression levels and were more than 98% similar to microglia NIS determined by CHI3L1. According to our results, high levels of CHI3L1 and CHI3L2 in the brains of AD patients are associated with inflammatory transcriptomic signatures. The high correlation between CHI3L1 and CHI3L2 suggests strong co-regulation.

The Value of Serum CHI3L1 for the Diagnosis of Chronic Liver Diseases

Objective

To explore the value of chitinase-3-like protein 1 (CHI3L1) for the diagnosis of patients with chronic liver diseases such as chronic viral hepatitis B, liver cirrhosis and hepatocellular carcinoma (HCC), and analyze the correlation between serum CHI3L1 level and Child–Pugh grading of chronic liver diseases.

Methods

The serum CHI3L1 levels of 154 cases of chronic viral hepatitis B, 132 cases of liver cirrhosis and 88 cases of HCC were detected by ELISA, and 92 healthy subjects were taken as the control.

Results

The –serum CHI3L1 levels in HCC group, liver cirrhosis group and chronic viral hepatitis B group were higher than in healthy control group (P < 0.001). Serum CHI3L1 level showed a trend of increase in patients with chronic hepatitis to liver cirrhosis and to HCC. The diagnostic efficacy of serum CHI3L1 level on liver cirrhosis showed the sensitivity of 64.4% and the specificity of 96.7%. The diagnostic efficacy of serum CHI3L1 level on HCC showed the sensitivity of 86.8% and the specificity of 97.8%. Serum CHI3L1 level was higher in Child–Pugh grade B and C patients than in Child–Pugh grade A patients, and was positively correlated with Child–Pugh grading of liver function (rs = 0.301, P < 0.001).

Conclusion

Serum CHI3L1 level increased in chronic liver diseases and showed an increase trend with the progression of liver diseases. Serum CHI3L1 could be a biomarker for the auxiliary diagnosis of chronic liver diseases.

The Dual Effect of Rho-Kinase Inhibition on Trabecular Meshwork Cells Cytoskeleton and Extracellular Matrix in an In Vitro Model of Glaucoma

The trabecular meshwork (TM) is the main site of drainage of the aqueous humor, and its dysfunction leads to intraocular pressure elevation, which is one of the main risk factors of glaucoma. We aimed to compare the effects on cytoskeleton organization and extracellular matrix (ECM) of latanoprost (LT) and a Rho-kinase inhibitor (ROCKi) on a transforming growth factor beta2 (TGF-β2)-induced glaucoma-like model developed from primary culture of human TM cells (pHTMC). The TGF-β2 stimulated pHTMC were grown and incubated with LT or a ROCKi (Y-27632) for 24 h. The expression of alpha-smooth muscle actin (αSMA) and fibronectin (FN), and phosphorylation of the myosin light chain (MLC-P) and Cofilin (Cofilin-P) were evaluated using immunofluorescence and Western blot. The architectural modifications were studied in a Matrigel^TM 3D culture. TGF-β2 increased the expression of αSMA and FN in pHTMC and modified the cytoskeleton with cross-linked actin network formation. LT did not alter the expression of αSMA but decreased FN deposition. The ROCKi decreased TGF-β2-induced αSMA and FN expression, as well as MLC-P and Cofilin-P, and stimulated the cells to recover a basal cytoskeletal arrangement. In the preliminary 3D study, pHTMC organized in a mesh conformation showed the widening of the TM under the effect of Y-27632. By simultaneously modifying the organization of the cytoskeleton and the ECM, with fibronectin deposition and overexpression, TGF-β2 reproduced the trabecular degeneration described in glaucoma. The ROCKi was able to reverse the TGF-β2-induced cytoskeletal and ECM rearrangements. LT loosened the extracellular matrix but had no action on the stress fibers.

ILF3 Is a Negative Transcriptional Regulator of Innate Immune Responses and Myeloid Dendritic Cell Maturation

APCs such as myeloid dendritic cells (DCs) are key sentinels of the innate immune system. In response to pathogen recognition and innate immune stimulation, DCs transition from an immature to a mature state that is characterized by widespread changes in host gene expression, which include the upregulation of cytokines, chemokines, and costimulatory factors to protect against infection. Several transcription factors are known to drive these gene expression changes, but the mechanisms that negatively regulate DC maturation are less well understood. In this study, we identify the transcription factor IL enhancer binding factor 3 (ILF3) as a negative regulator of innate immune responses and DC maturation. Depletion of ILF3 in primary human monocyte-derived DCs led to increased expression of maturation markers and potentiated innate responses during stimulation with viral mimetics or classic innate agonists. Conversely, overexpression of short or long ILF3 isoforms (NF90 and NF110) suppressed DC maturation and innate immune responses. Through mutagenesis experiments, we found that a nuclear localization sequence in ILF3, and not its dual dsRNA-binding domains, was required for this function. Mutation of the domain associated with zinc finger motif of ILF3's NF110 isoform blocked its ability to suppress DC maturation. Moreover, RNA-sequencing analysis indicated that ILF3 regulates genes associated with cholesterol homeostasis in addition to genes associated with DC maturation. Together, our data establish ILF3 as a transcriptional regulator that restrains DC maturation and limits innate immune responses through a mechanism that may intersect with lipid metabolism.

Brain CHID1 Expression Correlates with NRGN and CALB1 in Healthy Subjects and AD Patients

Alzheimer’s disease is a progressive, devastating, and irreversible brain disorder that, day by day, destroys memory skills and social behavior. Despite this, the number of known genes suitable for discriminating between AD patients is insufficient. Among the genes potentially involved in the development of AD, there are the chitinase-like proteins (CLPs) CHI3L1, CHI3L2, and CHID1. The genes of the first two have been extensively investigated while, on the contrary, little information is available on CHID1. In this manuscript, we conducted transcriptome meta-analysis on an extensive sample of brains of healthy control subjects (n = 1849) (NDHC) and brains of AD patients (n = 1170) in order to demonstrate CHID1 involvement. Our analysis revealed an inverse correlation between the brain CHID1 expression levels and the age of NDHC subjects. Significant differences were highlighted comparing CHID1 expression of NDHC subjects and AD patients. Exclusive in AD patients, the CHID1 expression levels were correlated positively to calcium-binding adapter molecule 1 (IBA1) levels. Furthermore, both in NDHC and in AD patient’s brains, the CHID1 expression levels were directly correlated with calbindin 1 (CALB1) and neurogranin (NRGN). According to brain regions, correlation differences were shown between the expression levels of CHID1 in prefrontal, frontal, occipital, cerebellum, temporal, and limbic system. Sex-related differences were only highlighted in NDHC. CHID1 represents a new chitinase potentially involved in the principal processes underlying Alzheimer’s disease.

Chitinases and chitinase-like proteins as biomarkers in neurologic disorders

Chitinases are hydrolytic enzymes widely distributed in nature. Despite their physiologic and pathophysiologic roles are not well understood, chitinases are emerging as biomarkers in a broad range of neurologic disorders, where in many cases, protein levels measured in the CSF have been shown to correlate with disease activity and progression. In this review, we will summarize the structural features of human chitinases and chitinase-like proteins and their potential physiologic and pathologic functions in the CNS. We will also review existing evidence for the role of chitinases and chitinase-like proteins as diagnostic and prognostic biomarkers in inflammatory, neurodegenerative diseases, and psychiatric disorders. Finally, we will comment on future perspectives of chitinase studies in neurologic conditions.

Postsynaptic damage and microglial activation in AD patients could be linked CXCR4/CXCL12 expression levels

Alzheimer's disease (AD) is one of the most common forms of dementia with still unknown pathogenesis. Several cytokines and chemokines are involved in the pathogenesis of AD. Among the chemokines, the CXCR4/CXCL12 complex has been shown to play an important role in the pathogenetic development of AD. We investigated the expression levels of CXCR4 / CXCL12 in fifteen brain regions of healthy non-demented subjects (NDHC) (2139 sample) and AD patients (1170 sample) stratified according to sex and age. Furthermore, we correlated their expressions with the Neurogranin (NRGN) and CHI3L1 levels, two inflamm-aging markers. We highlighted that CXCR4 gene expression levels were age-correlated in the brain of NDHC subjects and that AD nullified this correlation. A similar trend, but diametrically opposite was observed for CXCL12. Its expression was decreased during the aging in both sexes, and in the brains of AD patients, it underwent an inversion of the trend, only and exclusively in females. Brains of AD patients expressed high CXCR4 and CHI3L1, and low CXCL12 and Neurogranin levels compared to NDHC subjects. Both CXCR4 and CXCL12 correlated significantly with CHI3L1 and Neurogranin expression levels, regardless of disease. Furthermore, we showed a selective modulation of CXCL12 and CXCR4 only in specific brain regions. Taken together our results demonstrate that CXCL12 and CXCR4 are linked to Neurogranin and CHI3L1 expression levels and the relationship between postsynaptic damage and microglial activation in AD could be shown using all these genes. Further confirmations are needed to demonstrate the close link between these genes.

Chitinase-3 like-protein-1 function and its role in diseases

Non-enzymatic chitinase-3 like-protein-1 (CHI3L1) belongs to glycoside hydrolase family 18. It binds to chitin, heparin, and hyaluronic acid, and is regulated by extracellular matrix changes, cytokines, growth factors, drugs, and stress. CHI3L1 is synthesized and secreted by a multitude of cells including macrophages, neutrophils, synoviocytes, chondrocytes, fibroblast-like cells, smooth muscle cells, and tumor cells. It plays a major role in tissue injury, inflammation, tissue repair, and remodeling responses. CHI3L1 has been strongly associated with diseases including asthma, arthritis, sepsis, diabetes, liver fibrosis, and coronary artery disease. Moreover, following its initial identification in the culture supernatant of the MG63 osteosarcoma cell line, CHI3L1 has been shown to be overexpressed in a wealth of both human cancers and animal tumor models. To date, interleukin-13 receptor subunit alpha-2, transmembrane protein 219, galectin-3, chemo-attractant receptor-homologous 2, and CD44 have been identified as CHI3L1 receptors. CHI3L1 signaling plays a critical role in cancer cell growth, proliferation, invasion, metastasis, angiogenesis, activation of tumor-associated macrophages, and Th2 polarization of CD4⁺ T cells. Interestingly, CHI3L1-based targeted therapy has been increasingly applied to the treatment of tumors including glioma and colon cancer as well as rheumatoid arthritis. This review summarizes the potential roles and mechanisms of CHI3L1 in oncogenesis and disease pathogenesis, then posits investigational strategies for targeted therapies.

CHI3L2 Expression Levels Are Correlated with AIF1, PECAM1, and CALB1 in the Brains of Alzheimer's Disease Patients

Alzheimer's disease (AD) represents one of the main forms of dementia that afflicts our society. The expression of several genes has been associated with disease development. Despite this, the number of genes known to be capable of discriminating between AD patients according to sex remains deficient. In our study, we performed a transcriptomes meta-analysis on a large court of brains of healthy control subjects (n = 2139) (NDHC) and brains of AD patients (n = 1170). Our aim was to verify the brain expression levels of CHI3L2 and its correlation with genes associated with microglia-mediated neuroinflammation (IBA1), alteration of the blood-brain barrier (PECAM1), and neuronal damage (CALB1). We showed that the CHI3L2, IBA1, PECAM1, and CALB1 expression levels were modulated in the brains of patients with AD compared to NDHC subjects. Furthermore, both in NDHC and in AD patient's brains, the CHI3L2 expression levels were directly correlated with IBA1 and PECAM1 and inversely with CALB1. Additionally, the expression levels of CHI3L2, PECAM1, and CALB1 but not of IBA1 were sex-depended. By stratifying the samples according to age and sex, correlation differences emerged between the expression levels of CHI3L2, IBA1, PECAM1, and CALB1 and the age of NDHC subjects and AD patients. CHI3L2 represents a promising gene potentially involved in the key processes underlying Alzheimer's disease. Its expression in the brains of sex-conditioned AD patients opens up new possible sex therapeutic strategies aimed at controlling imbalance in disease progression.

Abnormal polarization of macrophage-like cells in the peripheral blood of patients with glioma

Glioma is a type of malignant tumor arising from glial cells of the brain or the spine. Circulation-derived macrophage infiltration is a characteristic of the glioma microenvironment. The polarization status of circulation-derived macrophages in patients with glioma remains unclear. Therefore, the present study aimed to evaluate the polarization status of circulation-derived macrophages in patients with glioma. A total of 40 patients with glioma and 38 healthy volunteers were recruited. The polarization status of macrophage-like cells in the peripheral blood of patients with glioma was evaluated. In addition, the associations between the polarization status of macrophage-like cells and glioma stage or the expression levels of the glioma tumor marker chitinase-3-like protein 1 (also termed YKL-40) were evaluated. The number of macrophage-like cells (CD115+CD1c-CD2-CD15-CD19-CD14+CD16+CD11b+) was higher in the peripheral blood of patients with glioma compared with that of healthy volunteers. There were fewer M1 macrophage-like cells, and more M2 macrophage-like cells were induced in the peripheral blood of patients with glioma compared with healthy controls. Specifically, the number of M2a/M2b macrophage-like cells increased, whereas that of M2c macrophage-like cells decreased in the peripheral blood of patients with glioma compared with healthy controls. The polarization status of macrophage-like cells in patients with glioma was not significantly associated with glioma stage or with the glioma marker YKL-40. Overall, the results of the present study revealed that the polarization status of macrophage-like cells in the peripheral blood of patients with glioma was abnormal, offering potential novel diagnostic and therapeutic targets, such as different macrophage subsets, for glioma.

The expression levels of CHI3L1 and IL15Rα correlate with TGM2 in duodenum biopsies of patients with celiac disease

OBJECTIVE AND DESIGN

Celiac disease (CD) is an intestinal inflammatory disorder of the small intestine. Gliadins are a component of gluten and there are three main types (α, γ, and ω). Recent studies indicate that gliadin peptides are able to activate an innate immune response. IL15 is a major mediator of the innate immune response and is involved in the early alteration of CD mucosa. The chitinase molecules are highly expressed by the innate immune cells during the inflammatory processes.

MATERIAL OR SUBJECTS

We analyzed several microarray datasets of PBMCs and duodenum biopsies of CD patients and healthy control subjects (HCs). We verified the modulation CHI3L1 in CD patients and correlated the expression levels to the IL15, IL15Rα, TGM2, IFNγ, and IFNGR1/2. Duodenal biopsy samples belonged to nine active and nine treated children patients (long-term effects of gliadin), and 17 adult CD patients and 10 adults HCs. We also selected 169 samples of PBMCs from 127 CD patients on adherence to a gluten-free diet (GFD) for at least 2 years and 44 HCs.

RESULTS

Our analysis showed that CHI3L1 and IL15Rα were significantly upregulated in adult and children's celiac duodenum biopsies. In addition, the two genes were correlated significantly both in children than in adults CD duodenum biopsies. No significant modulation was observed in PBMCs of adult CD patients compared to the HCs. The correlation analysis of the expression levels of CHI3L1 and IL15Rα compared to TGM showed significant values both in adults and in children duodenal biopsies. Furthermore, the IFNγ expression levels were positively correlated with CHI3L1 and IL15Rα. Receiver operating characteristic (ROC) analysis confirmed the diagnostic ability of CHI3L1 and IL15Rα to discriminate CD from HCs.

CONCLUSION

Our data suggest a role for CHI3L1 underlying the pathophysiology of CD and represent a starting point aiming to inspire new investigation that proves the possible use of CHI3L1 as a diagnostic factor and therapeutic target.

Chitinase 3 like 1 suppresses the stability and activity of p53 to promote lung tumorigenesis

Background

Chitinase 3 like 1 protein (Chi3L1) is expressed in several cancers, and a few evidences suggest that the secreted Chi3L1 contributes to tumor development. However, the molecular mechanisms of intracellular Chi3L1 are unknown in the lung tumor development. Methods: In the present study, we generated Chi3L1 knockout mice (Chi3L1^KO(−/−)) using CRISPR/Cas9 system to investigate the role of Chi3L1 on lung tumorigenesis.

Results

We established lung metastasis induced by i.v. injections of B16F10 in Chi3L1^KO(−/−). The lung tumor nodules were significantly reduced in Chi3L1^KO(−/−) and protein levels of p53, p21, BAX, and cleaved-caspase 3 were significantly increased in Chi3L1^KO(−/−), while protein levels of cyclin E1, CDK2, and phsphorylation of STAT3 were decreased in Chi3L1^KO(−/−). Allograft mice inoculated with B16F10 also suppressed tumor growth and increased p53 and its target proteins including p21 and BAX. In addition, knockdown of Chi3L1 in lung cancer cells inhibited lung cancer cell growth and upregulated p53 expression with p21 and BAX, and a decrease in phosphorylation of STAT3. Furthermore, we found that intracellular Chi3L1 physically interacted and colocalized with p53 to inhibit its protein stability and transcriptional activity for target genes related with cell cycle arrest and apoptosis. In lung tumor patient, we clinically found that Chi3L1 expression was upregulated with a decrease in p53 expression, as well as we validated that intracellular Chi3L1 was colocalized, reversely expressed, and physically interacted with p53, which results in suppression of the expression and function of p53 in lung tumor patient.

Conclusions

Our studies suggest that intracellular Chi3L1 plays a critical role in the lung tumorigenesis by regulating its novel target protein, p53 in both an in vitro and in vivo system.

Elevated plasma YKL-40 level is found in the dogs with cancer and is related to poor prognosis

YKL-40, a secreted glycoprotein, may serve as an autoantigen, which mediates multiple inflammatory diseases and cancers. A high YKL-40 serum level is correlated with metastasis and poor survival in a variety of human cancers. However, the role of YKL-40 in dogs is still under evaluation. Herein, we examined the associations between plasma YKL-40 level and YKL-40 autoantibody (YAA) titers with malignancy and prognosis in canine cancer. Plasma levels of YKL-40 in healthy dogs (n = 20) and in dogs (n = 82) with cancer were evaluated using enzyme-linked immunosorbent assay. Our results indicated that plasma YKL-40 levels were significantly higher (p < 0.01) in dogs with cancer than in healthy dogs. A significant decrease in the YAA titers was detected in the dogs with cancer when compared with those of the healthy dogs (p < 0.05), although the change was not correlated with the YKL-40 levels. Among the dogs with cancer, plasma YKL-40 levels in the dogs that later relapsed or had metastasis were significantly higher than in the dogs with no signs of relapse (p < 0.01) or metastasis (p <0.05). The relapse and metastasis rates were significantly higher in the high YKL-40 group (> 180 pg/mL) than in the low YKL-40 group (< 180 pg/mL). The results imply that plasma YKL-40 levels might have the potential to be developed as a marker of malignancy progression and prognosis in canine cancers.

Roles of chitinase 3-like 1 in the development of cancer, neurodegenerative diseases, and inflammatory diseases

Chitinase 3-like 1 (CHI3L1) is a secreted glycoprotein that mediates inflammation, macrophage polarization, apoptosis, and carcinogenesis. The expression of CHI3L1 is strongly increased by various inflammatory and immunological conditions, including rheumatoid arthritis, multiple sclerosis, Alzheimer's disease, and several cancers. However, its physiological and pathophysiological roles in the development of cancer and neurodegenerative and inflammatory diseases remain unclear. Several studies have reported that CHI3L1 promotes cancer proliferation, inflammatory cytokine production, and microglial activation, and that multiple receptors, such as advanced glycation end product, syndecan-1/αVβ3, and IL-13Rα2, are involved. In addition, the pro-inflammatory action of CHI3L1 may be mediated via the protein kinase B and phosphoinositide-3 signaling pathways and responses to various pro-inflammatory cytokines, including tumor necrosis factor-α, interleukin-1β, interleukin-6, and interferon-γ. Therefore, CHI3L1 could contribute to a vast array of inflammatory diseases. In this article, we review recent findings regarding the roles of CHI3L1 and suggest therapeutic approaches targeting CHI3L1 in the development of cancers, neurodegenerative diseases, and inflammatory diseases.

Development and Characterization of a Novel Monoclonal Antibody Against Chitinase-like Protein CHID1 Applicable for Immunohistochemistry on Formalin Fixed Paraffin-Embedded Sections

CHID1 has been recently described as a predictive marker of different malignant tumors. Thus, monoclonal antibodies (mAbs) for CHID1 detection in different human liquids and in tissues are an important tool for the diagnosis of CHID1-positive cancers. However, only few mAbs have been established to date. In this study we describe the generation of a new hybridoma clone 3D4 producing anti-CHID1 antibodies. 3D4 mAb specifically binds human CHID1 and was successfully used in enzyme-linked immunosorbent assay, immunoblotting, immunofluorescence on paraformaldehyde-fixed cells, and in immunohistochemistry of paraffin-embedded tissue specimens. These results indicate that this new anti-CHID1 mAb 3D4 will be useful in the diagnosis of CHID1-related cancers and is a strong tool for both basic and clinical research on chitinase-like proteins.

Regulation of chitinase-3-like-1 in T cell elicits Th1 and cytotoxic responses to inhibit lung metastasis

Chitinase-3-like-1 (Chi3l1) is known to play a significant role in the pathogenesis of Type 2 inflammation and cancer. However, the function of Chi3l1 in T cell and its clinical implications are largely unknown. Here we show that Chi3l1 expression was increased in activated T cells, especially in Th2 cells. In addition, Chi3l1-deficient T cells are hyper-responsive to TcR stimulation and are prone to differentiating into Th1 cells. Chi3l1-deficient Th1 cells show increased expression of anti-tumor immunity genes and decreased Th1 negative regulators. Deletion of Chi3l1 in T cells in mice show reduced melanoma lung metastasis with increased IFNγ and TNFα-producing T cells in the lung. Furthermore, silencing of Chi3l1 expression in the lung using peptide-siRNA complex (dNP2-siChi3l1) efficiently inhibit lung metastasis with enhanced Th1 and CTL responses. Collectively, this study demonstrates Chi3l1 is a regulator of Th1 and CTL which could be a therapeutic target to enhance anti-tumor immunity.

Chitinase-like proteins as regulators of innate immunity and tissue repair: helpful lessons for asthma?

Chitinases and chitinase-like proteins (CLPs) belong to the glycoside hydrolase family 18 of proteins. Chitinases are expressed in mammals and lower organisms, facilitate chitin degradation, and hence act as host-defence enzymes. Gene duplication and loss-of-function mutations of enzymatically active chitinases have resulted in the expression of a diverse range of CLPs across different species. CLPs are genes that are increasingly associated with inflammation and tissue remodelling not only in mammals but also across distant species. While the focus has remained on understanding the functions and expression patterns of CLPs during disease in humans, studies in mouse and lower organisms have revealed important and overlapping roles of the CLP family during physiology, host defence and pathology. This review will summarise recent insights into the regulatory functions of CLPs on innate immune pathways and discuss how these effects are not only important for host defence and tissue injury/repair after pathogen invasion, but also how they have extensive implications for pathological processes involved in diseases such as asthma.

Antimicrobial and Anti-Proliferative Effects of Skin Mucus Derived from Dasyatis pastinaca (Linnaeus, 1758)

Resistance to chemotherapy occurs in various diseases (i.e., cancer and infection), and for this reason, both are very difficult to treat. Therefore, novel antimicrobial and chemotherapic drugs are needed for effective antibiotic therapy. The aim of the present study was to assess the antimicrobial and anti-proliferative effects of skin mucus derived from Dasyatis pastinaca (Linnaeus, 1758). Our results showed that skin mucus exhibited a significant and specific antibacterial activity against Gram-negative bacteria but not against Gram-positive bacteria. Furthermore, we also observed a significant antifungal activity against some strains of Candida spp. Concerning anti-proliferative activity, we showed that fish mucus was specifically toxic for acute leukemia cells (HL60) with an inhibition of proliferation in a dose dependent manner (about 52% at 1000 μg/mL of fish skin mucous, FSM). Moreover, we did not observe effects in healthy cells, in neuroblastoma cells (SH-SY5Y), and multiple myeloma cell lines (MM1, U266). Finally, it exhibited strong expression and activity of chitinase which may be responsible, at least in part, for the aforementioned results.

Vitamin D3 regulates LAMP3 expression in monocyte derived dendritic cells

The family of lysosome-associated membrane proteins (LAMPs) encompassing LAMP1, LAMP2 and DC-LAMP (LAMP3) are the major constituents of the glycoconjugates coat present on the inside of the lysosomal membrane. LAMP3 is highly expressed only in certain cell types and during the differentiation stages. Its expression is linked the maturation of dendritic cells, inflammation, poor prognosis of certain tumors, and the locus where it is encoded was identified as a risk factor for Parkinson's disease (PD). Here, we investigated the capacity of Vitamin D3 to modulate the expression of LAMP3 during the dendritic cells differentiation and maturation. Our results demonstrated that the Vitamin D3 reduce the LAMP3 mRNA/protein expression during the dendritic cells differentiation and maturation, via NFκB pathways. Furthermore, we demonstrated that the Vitamin D3 was able to modulate the expression of LAMP3 likewise to in vitro tolerogenic dendritic cells. In summary, these data showed that the decrease of LAMP3 expression by Vitamin D3could enhance the tolerogenic characteristic of dendritic cells.

Inflammatory landscape of human brain tumors reveals an NFκB dependent cytokine pathway associated with mesenchymal glioblastoma

The tumor microenvironment is being increasingly recognized as a key factor in cancer aggressiveness. In this study, we characterized the inflammatory gene signatures altered in glioma cell lines and tumor specimens of differing histological and molecular subtypes. The results showed that glioblastoma multiforme (GBM) shows upregulation of a subset of inflammatory genes when compared to astrocytomas and oligodendrogliomas. With molecular subtypes of GBM, the expression of inflammatory genes is heterogeneous, being enriched in mesenchymal and downregulated in Proneural/GCIMP. Other inflammation-associated processes such as tumor-associated macrophage (TAM) signatures are upregulated in mesenchymal, and a subset of 33 mesenchymal-enriched inflammatory and TAM markers showed correlation with poor survival. We found that various GBM tumor-upregulated genes such as IL6, IL8 and CCL2 are also actively expressed in glioma cell lines, playing differential and cooperative roles in promoting proliferation, invasion, angiogenesis and macrophage polarization in vitro. These genes can be stimulated by pathways typically altered in GBM, including the EGFR, PDGFR, MEK1/2-ERK1/2, PI3K/Akt and NFκB cascades. Taken together, the results presented herein depict some inflammatory pathways altered in gliomas and highlight potentially relevant targets to therapy improvement.

New insights on chitinases immunologic activities

Mammalian chitinases and the related chilectins (ChiLs) belong to the GH18 family, which hydrolyse the glycosidic bond of chitin by a substrate-assisted mechanism. Chitin the fundamental component in the coating of numerous living species is the most abundant natural biopolymer. Mounting evidence suggest that the function of the majority of the mammalian chitinases is not exclusive to catalyze the hydrolysis of chitin producing pathogens, but include crucial role specific in the immunologic activities. The chitinases and chitinase-like proteins are expressed in response to different proinflammatory cues in various tissues by activated macrophages, neutrophils and in different monocyte-derived cell lines. The mechanism and molecular interaction of chitinases in relation to immune regulation embrace bacterial infection, inflammation, dismetabolic and degenerative disease. The aim of this review is to update the reader with regard to the role of chitinases proposed in the recent innate and adaptive immunity literature. The deep scrutiny of this family of enzymes could be a useful base for further studies addressed to the development of potential procedure directing these molecules as diagnostic and prognostic markers for numerous immune and inflammatory diseases.