YKL-40 Promotes Proliferation of Cutaneous T-Cell Lymphoma Tumor Cells through Extracellular Signal-Regulated Kinase Pathways

YKL-40 immunoexpression as a prognosticator of mycosis fungoides

BACKGROUND

YKL-40 is a 40 kDa chitinase-like glycoprotein that is predicted to contribute to the pathogenesis of several inflammatory and neoplastic conditions.

OBJECTIVES

To assess YKL-40 immunoexpression in different stages of mycosis fungoides (MF) to find out if YKL-40 is playing a possible role in disease pathophysiology and progression.

METHODS

This work included 50 patients with different stages of MF diagnosed on the basis of clinical, histopathological, and both CD4 and CD8 immunophenotyping, in addition to 25 normal control skin. The Immune Reactive Score (IRS) of YKL-40 expression was determined in all specimens and statistically analyzed.

RESULTS

YKL-40 expression reported a significant rise in MF lesions compared to control skin. Among MF specimens, the mildest expression was observed in the early patch stage followed by the plaque stage, while the strongest was in tumor stages. Positive correlations were discovered between IRS of YKL-40 expression in MF specimens and patients' age, disease chronicity, clinical staging, and TNMB classification.

CONCLUSION

YKL-40 might participate in MF pathophysiology, and the highest expression is associated with advanced stages of the disease and poor outcomes. Therefore, it might be of value as a prognosticator for monitoring high-risk MF patients and follow-up assessment of treatment success.

Possible mechanism of CHI3L1 promoting tonsil lymphocytes proliferation in children with obstructive sleep apnea syndrome

BACKGROUND

The typical characteristic of pediatric obstructive sleep apnea syndrome (OSAS) is systemic inflammation and adenotonsillar hypertrophy (ATH), but the inflammatory markers and mechanism of adenotonsillar proliferation are unclear.

METHODS

IHC, qPCR, and western blotting were used to identify the expression of CHI3L1 in the tonsils of children with OSAS. The primary tonsil lymphocytes (PTLCs) from children with OSAS were cultured and recombinant human CHI3L1 protein was added to culture media. After the stimulation with CHI3L1 protein of different concentrations and time points, lymphocyte proliferation was assessed by CCK-8 kits and flow cytometry. The activation of ERK1/2 and the effects on the proliferation of PTLCs were observed by western blotting.

RESULTS

The expression of CHI3L1 was higher in the OSAS group than in the PS group. CHI3L1 (100 ng/mmol for 24 h) resulted in a significant increase in the proliferation rate. The ERK1/2 activator (PMA) promoted the proliferation of PTLCs and inhibitor AG126 significantly inhibited proliferation.

CONCLUSIONS

CHI3L1 can promote the proliferation of tonsil lymphocytes via ERK1/2 pathways. This result indicates that CHI3L1 may play an important role in the pathogenesis of OSAS in children. Inhibition of CHI3L1 or ERK1/2 may be potential therapeutic targets for CHI3L1-induced proliferation in childhood OSAS.

IMPACT

CHI3L1 may be an inflammatory marker in childhood OSAS. CHI3L1 can promote the proliferation of PTLCs in a concentration and time-dependent condition. CHI3L1 can promote the proliferation of tonsil lymphocytes via ERK1/2 pathways.

CD147-Cyclophilin a Interactions Promote Proliferation and Survival of Cutaneous T-Cell Lymphoma

CD147, a transmembrane glycoprotein that belongs to the immunoglobulin superfamily, and cyclophilin A (CypA), one of the binding partners of CD147, are overexpressed in tumor cells and associated with the progression of several malignancies, including both solid and hematological malignancies. However, CD147 and CypA involvement in cutaneous T-cell lymphoma (CTCL) has not been reported. In this study, we examined CD147 and CypA expression and function using clinical samples of mycosis fungoides (MF) and Sézary syndrome (SS) and CTCL cell lines. CD147 and CypA were overexpressed by tumor cells of MF/SS, and CypA was also expressed by epidermal keratinocytes in MF/SS lesional skin. Serum CypA levels were increased and correlated with disease severity markers in MF/SS patients. Anti-CD147 antibody and/or anti-CypA antibody suppressed the proliferation of CTCL cell lines, both in vitro and in vivo, via downregulation of phosphorylated extracellular-regulated kinase 1/2 and Akt. These results suggest that CD147-CypA interactions can contribute to the proliferation of MF/SS tumor cells in both a autocrine and paracrine manner, and that the disruption of CD147-CypA interactions could be a new therapeutic strategy for the treatment of MF/SS.

Inhibition of Chitinase-3-like-1 by K284-6111 Reduces Atopic Skin Inflammation via Repressing Lactoferrin

Chitinase-3-like-1 (CHI3L1) is known to induce inflammation in the progression of allergic diseases. Previous our studies revealed that 2-({3-[2-(1-cyclohexen-1-yl)ethyl]-6,7-dimethoxy-4-oxo-3,4-dihydro-2-quinazolinyl}sulfanyl)-N-(4-ethylphenyl)butanamide (K284-6111; K284), the CHI3L1 inhibiting compound, has the anti-inflammatory effect on neuroinflammation. In this study, we investigated that K284 treatment could inhibit the development of atopic dermatitis (AD). To identify the effect of K284, we used phthalic anhydride (5% PA)-induced AD animal model and in vitro reconstructed human skin model. We analyzed the expression of AD-related cytokine mediators and NF-κB signaling by Western blotting, ELISA and quantitative real-time PCR. Histological analysis showed that K284 treatment suppressed PA-induced epidermal thickening and infiltration of mast cells. K284 treatment also reduced PA-induced release of inflammatory cytokines. In addition, K284 treatment inhibited the expression of NF-κB activity in PA-treated skin tissues and TNF-α and IFN-γ-treated HaCaT cells. Protein-association network analysis indicated that CHI3L1 is associated with lactoferrin (LTF). LTF was elevated in PA-treated skin tissues and TNF-α and IFN-γ-induced HaCaT cells. However, this expression was reduced by K284 treatment. Knockdown of LTF decreased the expression of inflammatory cytokines in TNF-α and IFN-γ-induced HaCaT cells. Moreover, anti-LTF antibody treatment alleviated AD development in PA-induced AD model. Our data demonstrate that CHI3L1 targeting K284 reduces AD-like skin inflammation and K284 could be a promising therapeutic agent for AD by inhibition of LTF expression.

Adenovirus vector-mediated YKL-40 shRNA attenuates eosinophil airway inflammation in a murine asthmatic model

Recent studies have revealed that YKL-40 is involved in the pathogenesis of asthma. However, its specific mechanism remains unclear. The present study aims to investigate the effect of adenovirus vector-mediated YKL-40 short hairpin RNA (shRNA) on regulation of airway inflammation in a murine asthmatic model. Mice were assessed for airway hyperresponsiveness (AHR), total leukocytes and the percentage of eosinophil cells in bronchoalveolar lavage fluid (BALF). YKL-40 mRNA and protein expression levels were detected using quantitative real-time PCR and western blot assays. Enzyme-linked immunosorbent assay (ELISA) was used to detect YKL-40 and eosinophil-related chemokine expression levels in BALF and serum. Lung histology analyses were performed to evaluate the degree of inflammatory cell infiltration around the airway and airway mucus secretion.YKL-40 shRNA significantly inhibited the YKL-40 gene expression in asthmatic mice. In addition, YKL-40 shRNA alleviated eosinophilic airway inflammation, AHR, airway mucus secretion and decreased the levels of YKL-40 in BALF and serum in a murine asthmatic model. The levels and mRNA expression of IL-5, IL-13 in asthmatic mice lung tissues, eotaxin, and GM-CSF in BALF and serum significantly decreased. Bone marrow signaling molecules including IL-5, eotaxin, and GM-CSF were correlated with decreased levels of YKL-40. The study reveals that YKL-40 could be involved in asthma inflammation by altering bone marrow signaling molecules. YKL-40 gene RNA interference could provide new therapeutic strategies for asthma.

Cellular Interactions and Inflammation in the Pathogenesis of Cutaneous T-Cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) comprises a group of lymphoproliferative diseases characterized by the accumulation of malignant T cells in chronically inflamed skin lesions. In early stages, the disease presents as skin patches or plaques covering a limited area of the skin and normally follows an indolent course. However, in a subset of patients the cutaneous lesions develop into tumors and the malignant T cells may spread to the lymphatic system, blood and internal organs with fatal consequences. Despite intensive research, the mechanisms driving disease progression remain incompletely understood. While most studies have focused on cancer cell-intrinsic oncogenesis, such as genetic and epigenetic events driving malignant transformation and disease progression, an increasing body of evidence shows that the interplay between malignant T cells and non-malignant cells plays a crucial role. Here, we outline some of the emerging mechanisms by which tumor, stromal and epidermal interactions may contribute to the progression of CTCL with particular emphasis on the crosstalk between fibroblasts, keratinocytes and malignant T cells.