Crosstalk between TRPV1 and immune regulation in Fuchs endothelial corneal dystrophy

Fuchs endothelial corneal dystrophy (FECD) is the leading indication for corneal transplantation worldwide. Our aim was to investigate the role of transient receptor potential vanilloid subtype 1 (TRPV1) and the associated immune regulation contributing to this pathological condition. Significant upregulation of TRPV1 was detected in the H2O2-induced in vitro FECD model. Based on gene expression microarray dataset GSE142538 and in vitro results, a comprehensive immune landscape was studied and a negative correlation was found between TRPV1 with different immune cells, especially regulatory T cells (Tregs). Functional analyses of the 313 TRPV1-related differentially expressed genes (DEGs) revealed the involvement of TRP-regulated calcium transport, as well as inflammatory and immune pathways. Four TRPV1-related core genes (MAPK14, GNB1, GNAQ, and ARRB2) were screened, validated by microarray dataset GSE112039 and the combined validation dataset E-GEAD-399 & 564, and verified by in vitro experiments. Our study suggested a potential crosstalk between TRPV1 and immune regulation contributing to FECD pathogenesis. The identified pivotal biomarkers and immune-related pathways provide a novel framework for future mechanistic and therapeutic studies of FECD.

Protein phosphatase 2A catalytic subunit β suppresses PMA/ionomycin-induced T-cell activation by negatively regulating PI3K/Akt signaling

The precise regulation of the T-cell activation process is critical for overall immune homeostasis. Although protein phosphatase 2A (PP2A) is required for T-cell development and function, the role of PPP2CB, which is the catalytic subunit β isoform of PP2A, remains unknown. In the present study, using a T cell-specific knockout mouse of PPP2CB (PPP2CB^fl/fl Lck-Cre⁺ ), we demonstrated that PPP2CB was dispensable for T-cell development in the thymus and peripheral lymphoid organs. Furthermore, PPP2CB deletion did not affect T-cell receptor (TCR)-induced T-cell activation or cytokine-induced T-cell responses; however, it specifically enhanced phorbol myristate acetate (PMA) plus ionomycin-induced T-cell activation with increased cellular proliferation, elevated CD69 and CD25 expression, and enhanced cytokine production (inteferon-γ, interleukin-2 and tumor necrosis factor). Mechanistic analyses suggested that the PPP2CB deletion enhanced activation of the phosphoinositide 3-kinase/Akt signaling pathway and Ca²⁺ flux following stimulation with PMA plus ionomycin. Moreover, the specific PI3K inhibitor rescued the augmented cell activation in PPP2CB-deficient T cells. Using mass spectrometry-based phospho-peptide analysis, we identified potential substrates of PPP2CB during PMA plus ionomycin-induced T-cell activation. Collectively, our study provides evidence of the specific role of PPP2CB in controlling PMA plus ionomycin-induced T-cell activation.

CRISPR/Cas9 genome editing reveals an essential role for basigin in maintaining a nonkeratinized squamous epithelium in cornea

One of the primary functions of nonkeratinized stratified squamous epithelia is to protect underlying tissues against chemical, microbial, and mechanical insult. Basigin is a transmembrane matrix metalloproteinase inducer commonly overexpressed during epithelial wound repair and cancer but whose physiological significance in normal epithelial tissue has not been fully explored. Here we used a CRISPR/Cas9 system to study the effect of basigin loss in a human cornea model of squamous epithelial differentiation. We find that epithelial cell cultures lacking basigin change shape and fail to produce a flattened squamous layer on the apical surface. This process is associated with the abnormal expression of the transcription factor SPDEF and the decreased biosynthesis of MUC16 and involucrin necessary for maintaining apical barrier function and structural integrity, respectively. Expression analysis of genes encoding tight junction proteins identified a role for basigin in promoting physiological expression of occludin and members of the claudin family. Functionally, disruption of basigin expression led to increased epithelial cell permeability as evidenced by the decrease in transepithelial electrical resistance and increase in rose bengal flux. Overall, these results suggest that basigin plays a distinct role in maintaining the normal differentiation of stratified squamous human corneal epithelium and could have potential implications to therapies targeting basigin function.

CD147 Expressed on Memory CD4+ T Cells Limits Th17 Responses in Patients With Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a common autoimmune disease in which T helper-type 17 (Th17) cells have been critically involved. CD147 is a T cell activation-associated molecule and is involved in T cell development. However, it remains unclear whether CD147 participates in Th17 responses in RA patients. In this study, we demonstrated that in both the RA and healthy controls (HC) groups, CD147 expression on CD4⁺ T cells was increased in CCR6⁺ and CD161⁺ subsets, and was associated with IL-17 production. Ligation of CD147 with its monoclonal antibody (mAb) strongly inhibited Th17 responses, and knock down of CD147 expression on CD4⁺ Tm cells specifically enhanced Th17 responses, triggered by coculture with in vitro activated monocytes from HC. Further functional studies showed that anti-CD147 mAb decreased the activation of AKT, mTORC1 and STAT3 signaling, which is known to enhance Th17 responses. Ligation of CD147 with its mAb on CD4⁺ Tm cells specifically reduced Th17 responses induced by in vitro or in vivo activated monocytes from RA patients. In collagen-induced arthritis model, anti-CD147 mAb treatment reduced the Th17 levels and severity of arthritis in vivo. These data suggest that CD147 plays a negative role in regulating human Th17 responses. Anti-CD147 mAb can limit the extraordinary proliferation of Th17 cells and may be a new therapeutic option in RA.

CD147 promotes proliferation and migration of oral cancer cells by inhibiting junctions between E-cadherin and β-catenin

BACKGROUND

Although association between oral squamous cell carcinoma (OSCC) with epithelial-mesenchymal transition (EMT) has been demonstrated, we found CD147, one transmembrane protein we previously studied in oral submucous fibrosis, was correlated with E-cadherin, one marker of EMT. Here, we investigated CD147 expression in the different stages of OSCC and assessed its association with epithelial-mesenchymal transition (EMT).

MATERIALS AND METHODS

CD147 and E-cadherin expression in tissue microarrays containing 48 OSCC specimens and matched adjacent tissues was analysed using immunohistochemistry. CD147 was overexpressed or knocked down using exogenous cloning vector and RNA interference, respectively, in OSCC cell lines. Cell proliferation and migration were measured using the CCK8 assay and scratch test, respectively. The expression and localization of EMT-associated proteins was analysed by Western blotting and immunofluorescence.

RESULTS

CD147 expression in OSCC tissues was significantly higher than that in adjacent tissues and was markedly higher in cancer tissues with metastasis (P < .05). CD147 expression showed significant negative correlation with E-cadherin expression. CD147 overexpression downregulated E-cadherin and inhibited its complex with β-catenin and then upregulated N-cadherin and vimentin. Additionally, alterations in CD147 protein expression affected proliferation and migration ability in OSCC cells and were related to β-catenin nuclear translocation.

CONCLUSION

CD147 plays an important role in tumorigenesis and metastasis by promoting EMT progression in OSCC. It may be considered as a novel potential diagnostic and therapeutic target for OSCC.

Experimental study on TGF-β1-mediated CD147 expression in oral submucous fibrosis

OBJECTIVE

Although previous evidence indicates that CD147 is closely involved in the progression of organ fibrosis and various signaling pathways have been proven to regulate its expression, the role of CD147 in oral submucous fibrosis (OSF) remains largely unknown.

METHODS

In this study, we investigated the expression of CD147 and transforming growth factor β1 (TGF-β1) in human samples of an OSF tissue array by immunohistopathology. Pearson's correlation analysis was conducted to explore the correlation between CD147 and TGF-β1. Immunofluorescence and Western blotting were used to investigate to levels of CD147 in Human Oral Keratinocytes (HOKs) followed by TGF-β1 or LY2157299, an inhibitor of TGF-β1 receptor and arecoline stimulation.

RESULTS

We found that CD147 was highly expressed in both HOKs and the fibrotic oral mucosa and that this expression was correlated with TGF-β1 expression. Additionally, CD147 levels were significantly associated with the fibrosis stage. The TGF-β1 signaling pathway was found to be mainly responsible for CD147 up-regulation after arecoline treatment whereas inhibition of TGF-β1 down-regulated CD147 expression.

CONCLUSION

Our findings suggest arecoline promotes CD147 expression via the TGF-β1 signaling pathway in HOKs, whereas overexpression of CD147 may promote OSF progression.

In vivo systems biology approaches to chronic immune/inflammatory pathophysiology

Systems biology offers an emphasis on integrative computational analysis of complex multi-component processes to enhance capability for predictive insights concerning operation of those processes. The immune system represents a prominent arena in which such processes are manifested for vital roles in physiology and pathology, encompassing dozens of cell types and hundreds of reciprocal interactions. Chronic, debilitating pathologies involving immune system dysregulation have become recognized as increasing in incidence over recent decades. While clinical consequences of immune dysregulation in such pathologies are well characterized, treatment options remain limited and focus on ameliorating symptoms. Because it is difficult to recapitulate more than a severely limited facet of the immune system in vitro, application of systems biology approaches to autoimmune and inflammatory pathophysiology in vivo has opened a new door toward discerning disease sub-groups and developing associated stratification strategies for patient treatment. In particular, early instances of these approaches have demonstrated advances in uncovering previously under-appreciated dysregulation of signaling networks between immune system and tissue cells, raising promise for improving upon current therapeutic approaches.