Ferroptosis is a nonapoptotic cell death process that requires cellular iron and the accumulation of lipid peroxides. In progressive rheumatoid arthritis (RA), synovial fibroblasts proliferate ...abnormally in the presence of reactive oxygen species (ROS) and elevated lipid oxidation. Here we show, using a collagen-induced arthritis (CIA) mouse model, that imidazole ketone erastin (IKE), a ferroptosis inducer, decreases fibroblast numbers in the synovium. Data from single-cell RNA sequencing further identify two groups of fibroblasts that have distinct susceptibility to IKE-induced ferroptosis, with the ferroptosis-resistant fibroblasts associated with an increased TNF-related transcriptome. Mechanistically, TNF signaling promotes cystine uptake and biosynthesis of glutathione (GSH) to protect fibroblasts from ferroptosis. Lastly, low dose IKE together with etanercept, a TNF antagonist, induce ferroptosis in fibroblasts and attenuate arthritis progression in the CIA model. Our results thus imply that the combination of TNF inhibitors and ferroptosis inducers may serve as a potential candidate for RA therapy.
In face of the everlasting battle toward COVID-19 and the rapid evolution of SARS-CoV-2, no specific and effective drugs for treating this disease have been reported until today. ...Angiotensin-converting enzyme 2 (ACE2), a receptor of SARS-CoV-2, mediates the virus infection by binding to spike protein. Although ACE2 is expressed in the lung, kidney, and intestine, its expressing levels are rather low, especially in the lung. Considering the great infectivity of COVID-19, we speculate that SARS-CoV-2 may depend on other routes to facilitate its infection. Here, we first discover an interaction between host cell receptor CD147 and SARS-CoV-2 spike protein. The loss of CD147 or blocking CD147 in Vero E6 and BEAS-2B cell lines by anti-CD147 antibody, Meplazumab, inhibits SARS-CoV-2 amplification. Expression of human CD147 allows virus entry into non-susceptible BHK-21 cells, which can be neutralized by CD147 extracellular fragment. Viral loads are detectable in the lungs of human CD147 (hCD147) mice infected with SARS-CoV-2, but not in those of virus-infected wild type mice. Interestingly, virions are observed in lymphocytes of lung tissue from a COVID-19 patient. Human T cells with a property of ACE2 natural deficiency can be infected with SARS-CoV-2 pseudovirus in a dose-dependent manner, which is specifically inhibited by Meplazumab. Furthermore, CD147 mediates virus entering host cells by endocytosis. Together, our study reveals a novel virus entry route, CD147-spike protein, which provides an important target for developing specific and effective drug against COVID-19.
Keratin 17 (K17), a marker of keratinocyte hyperproliferation, is a type I intermediate filament that is overexpressed in psoriatic epidermis and plays a critical pathogenic role by stimulating T ...cells. However, the posttranslational modification of K17, which is reversible and targetable, has not been elucidated. Herein, we reported that K17 could be modified through ubiquitination that controlled its stability and led to the phosphorylation and nuclear translocation of its interactor signal transducers and activators of transcription 3 (STAT3), which is a key regulator of cell proliferation in psoriasis. First, we stimulated human keratinocyte cell line HaCaT cells with psoriasis (pso)-mix, which is a cytokine pool (IL-17, IL-22, tumor necrosis factor-α, and IFN-γ) mimicking the in vitro “psoriasis-like” status and found that the ubiquitination of K17 was essential to stabilize its protein expression in pso-mix-treated HaCaT cells. Subsequently, tripartite motif-containing protein 21 was identified as the E3 ligase of K17, which ubiquitylated K17 via K63 linkage to maintain K17 stabilization. More importantly, we uncovered that K17 was a direct interactor of STAT3, and K17 ubiquitination could promote STAT3 activation in pso-mix-treated HaCaT cells. Our study demonstrated that targeting K17 ubiquitination may be a potential therapeutic approach by attenuating STAT3 signaling in psoriasis.
Hepatocytes are epithelial cells with highly specialized polarity. The disorder and loss of hepatocyte polarity leads to a weakness of cell adhesion and connection, the induction of ...epithelial–mesenchymal transition, and eventually the occurrence of hepatocellular carcinoma (HCC). Cluster of differentiation 147 (CD147), a tumor‐related glycoprotein, promotes epithelial–mesenchymal transition and the invasion of HCC. However, the function of CD147 in hepatocyte depolarization is unknown. Here we identified that CD147 was basolaterally polarized in hepatocyte membrane of liver tissues and HepG2 cells. CD147 not only promoted transforming growth factor‐β1–mediated hepatocyte polarity loss but also directly induced endocytosis and down‐regulation of E‐cadherin which contributed to hepatocyte depolarization. Overexpression of CD147 induced Src activation and subsequently recruited ubiquitin ligase Hakai for E‐cadherin ubiquitination and lysosomal degradation, leading to decreases of partitioning defective 3 expression and β‐catenin nuclear translocation. This signal transduction was initiated by competitive binding of CD147 with integrin β1 that interrupted the interaction between the Arg‐Gly‐Asp motif of fibronectin and integrin β1. The specific antibodies targeting integrin α5 and β1 reversed the decrease of E‐cadherin and partitioning defective 3 levels induced by CD147 overexpression. In human liver tissues, CD147 polarity rates significantly declined from liver cirrhosis (71.4%) to HCC (10.4%). CD147‐polarized localization negatively correlated with Child‐Pugh scores in human liver cirrhosis (r = –0.6092, P < 0.0001) and positively correlated with differentiation grades in HCC (r = 0.2060, P = 0.004). HCC patients with CD147‐polarized localization had significantly better overall survival than patients with CD147 nonpolarity (P = 0.021). Conclusion: The ectopic CD147‐polarized distribution on basolateral membrane promotes hepatocyte depolarization by activation of the CD147–integrin α5β1–E‐cadherin ubiquitination–partitioning defective 3 decrease and β‐catenin translocation signaling cascade, replenishing a molecular pathway in hepatic carcinogenesis. (Hepatology 2018;68:317‐332).
Breast cancer is the most common cancer in women for which the metastatic process is still poorly understood. CD147 is upregulated in breast cancer and has been associated with tumor progression, but ...little is known about its regulatory mechanisms. In this study, we demonstrated that CD147 was overexpressed in breast cancer tissues and cell lines, and the high expression correlated with tumor invasion and metastasis. We also found that the transcription factors Sp1 and c-Myc could bind to the CD147 promoter and enhance its expression. The CD147 mRNA has a 748-bp 3'-untranslated region (UTR) with many miRNA target sites, suggesting possible regulation by miRNAs. We discovered that miR-22 repressed CD147 expression by directly targeting the CD147 3'UTR. We also determined that miR-22 could indirectly participate in CD147 modulation by downregulating Sp1 expression. miR-22 could form an autoregulatory loop with Sp1, which repressed miR-22 transcription by binding to the miR-22 promoter. Together with the c-Myc-mediated inhibition of miR-22 expression, our investigation identified a miR-22/Sp1/c-Myc network that regulates CD147 gene transcription. In addition, miR-22 overexpression suppressed breast cancer cell invasion, metastasis, and proliferation by targeting CD147 in vitro and in vivo. Furthermore, we found that miR-22 was significantly downregulated in breast cancer tissues and that its expression was inversely correlated with the tumor-node-metastasis stage and lymphatic metastasis in patients. Our study provides the first evidence that an miR-22/Sp1/c-Myc network regulates CD147 upregulation in breast cancer and that miR-22 represses breast cancer invasive and metastatic capacities.
Abstract
SARS-CoV-2 mutations contribute to increased viral transmissibility and immune escape, compromising the effectiveness of existing vaccines and neutralizing antibodies. An in-depth ...investigation on COVID-19 pathogenesis is urgently needed to develop a strategy against SARS-CoV-2 variants. Here, we identified CD147 as a universal receptor for SARS-CoV-2 and its variants. Meanwhile, Meplazeumab, a humanized anti-CD147 antibody, could block cellular entry of SARS-CoV-2 and its variants—alpha, beta, gamma, and delta, with inhibition rates of 68.7, 75.7, 52.1, 52.1, and 62.3% at 60 μg/ml, respectively. Furthermore, humanized CD147 transgenic mice were susceptible to SARS-CoV-2 and its two variants, alpha and beta. When infected, these mice developed exudative alveolar pneumonia, featured by immune responses involving alveoli-infiltrated macrophages, neutrophils, and lymphocytes and activation of IL-17 signaling pathway. Mechanistically, we proposed that severe COVID-19-related cytokine storm is induced by a “spike protein-CD147-CyPA signaling axis”: Infection of SARS-CoV-2 through CD147 initiated the JAK-STAT pathway, which further induced expression of cyclophilin A (CyPA); CyPA reciprocally bound to CD147 and triggered MAPK pathway. Consequently, the MAPK pathway regulated the expression of cytokines and chemokines, which promoted the development of cytokine storm. Importantly, Meplazumab could effectively inhibit viral entry and inflammation caused by SARS-CoV-2 and its variants. Therefore, our findings provided a new perspective for severe COVID-19-related pathogenesis. Furthermore, the validated universal receptor for SARS-CoV-2 and its variants can be targeted for COVID-19 treatment.
Negative regulation of antitumor T-cell-immune responses facilitates tumor-immune escape. Here, we show that deletion of CD147, a type I transmembrane molecule, in T cells, strongly limits in vivo ...tumor growth of mouse melanoma and lung cancer in a CD8
T-cell-dependent manner. In mouse tumor models, CD147 expression was upregulated on CD8
tumor-infiltrating lymphocytes (TILs), and CD147 was coexpressed with two immune-checkpoint molecules, Tim-3 and PD-1. Mining publicly available gene-profiling data for CD8
TILs in tumor biopsies from metastatic melanoma patients showed a higher level of CD147 expression in exhausted CD8
TILs than in other subsets of CD8
TILs, along with expression of PD-1 and TIM-3. Additionally, CD147 deletion increased the abundance of TILs, cytotoxic effector function of CD8
T cells, and frequency of PD-1
CD8
TILs, and partly reversed the dysfunctional status of PD-1
Tim-3
CD8
TILs. The cytotoxic transcription factors Runx3 and T-bet mediation enhanced antitumor responses by CD147
CD8
T cells. Moreover, CD147 deletion in T cells increased the frequency of T
-like cells and the expression of the T-cell chemokines CXCL9 and CXCL10 in the tumor microenvironment. Analysis of tumor tissue samples from patients with non-small-cell lung cancer showed negative correlations between CD147 expression on CD8
TILs and the abundance of CD8
TILs, histological grade of the tumor tissue samples, and survival of patients with advanced tumors. Altogether, we found a novel function of CD147 as a negative regulator of antitumor responses mediated by CD8
TILs and identified CD147 as a potential target for cancer immunotherapy.
Non-small cell lung cancer (NSCLC) is a fatal disease, and its metastatic process is poorly understood. Although aberrant methylation is involved in tumor progression, the mechanisms underlying ...dynamic DNA methylation remain to be elucidated. It is significant to study the molecular mechanism of NSCLC metastasis and identify new biomarkers for NSCLC early diagnosis. Here, we performed MeDIP-seq and hMeDIP-seq analyses to detect the genes regulated by dynamic DNA methylation. Comparison of the 5mC and 5hmC sites revealed that the CD147 gene underwent active demethylation in NSCLC tissues compared with normal tissues, and this demethylation upregulated CD147 expression. Significantly high levels of CD147 expression and low levels of promoter methylation were observed in NSCLC tissues. Then, we identified the CD147 promoter as a target of KLF6, MeCP2, and DNMT3A. Treatment of cells with TGF-β triggered active demethylation involving loss of KLF6/MeCP2/DNMT3A and recruitment of Sp1, Tet1, TDG, and SMAD2/3 transcription complexes. A dCas9-SunTag-DNMAT3A-sgCD147-targeted methylation system was constructed to reverse CD147 expression. The targeted methylation system downregulated CD147 expression and inhibited NSCLC proliferation and metastasis in vitro and in vivo. Accordingly, we used cfDNA to detect the levels of CD147 methylation in NSCLC tissues and found that the CD147 methylation levels exhibited an inverse relationship with tumor size, lymphatic metastasis, and TNM stage. In conclusion, this study clarified the mechanism of active demethylation of CD147 and suggested that the targeted methylation of CD147 could inhibit NSCLC invasion and metastasis, providing a highly promising therapeutic target for NSCLC.
Genomic sequencing analysis of tumors provides potential molecular therapeutic targets for precision medicine. However, identifying a key driver gene or mutation that can be used for hepatocellular ...carcinoma (HCC) treatment remains difficult. Here, we performed whole-exome sequencing on genomic DNA obtained from six pairs of HCC and adjacent tissues and identified two novel somatic mutations of UBE2S (p. Gly57Ala and p. Lys63Asn). Predictions of the functional effects of the mutations showed that two amino-acid substitutions were potentially deleterious. Further, we observed that wild-type UBE2S, especially in the nucleus, was significantly higher in HCC tissues than that in adjacent tissues and closely related to the clinicopathological features of patients with HCC. Functional assays revealed that overexpression of UBE2S promoted the proliferation, invasion, metastasis, and G1/S phase transition of HCC cells in vitro, and promoted the tumor growth significantly in vivo. Mechanistically, UBE2S interacted with TRIM28 in the nucleus, both together enhanced the ubiquitination of p27 to facilitate its degradation and cell cycle progression. Most importantly, the small-molecule cephalomannine was found by a luciferase-based sensitive high-throughput screen (HTS) to inhibit UBE2S expression and significantly attenuate HCC progression in vitro and in vivo, which may represent a promising strategy for HCC therapy.
Nonalcoholic fatty liver disease (NAFLD) represents a global health problem. Impaired autophagy has been implicated in the pathogenesis of NAFLD, and CD147 is recognized to regulate lipid metabolism ...in a variety of cell types. This study was initiated with the aim to identify molecular makers expressed in hepatocytes that are significantly altered during the pathogenesis of NAFLD and closely associated with hepatic steatosis and autophagy. In this study, CD147 was found to be significantly associated with steatosis and autophagy in both clinical patients with NAFLD and NAFLD mouse models. In high-fat-diet-induced NAFLD mice, hepatic-specific CD147 knockout markedly reduced body weight, liver weight, serum aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT), and liver steatosis. In addition, hepatic CD147 gene knockout noticeably promoted autophagy in NAFLD mice (LC3 expression was increased with decreased P62 expression; molecular markers of autophagy). Moreover, we found that CD147 expression was significantly associated with AKT/mTOR signaling pathway; thus, suggesting that CD147 is involved in the regulation of autophagy and steatosis in NAFLD. In conclusion, this study has provided in vivo evidence for the putative role of CD147 in the pathogenesis of NAFLD and a valuable experimental basis for considering CD147 as a therapeutic target to prevent hepatic steatosis in patients with NAFLD.
•CD147 is a potential target of treatment in the early stage of nonalcoholic fatty liver disease.•The increased expression of hepatic CD147 is accompanied by increased steatosis and decreased autophagy in NAFLD patients.•Hepatic CD147 gene knockout attenuates liver steatosis and alleviates liver autophagy in high-fat-diet-induced NAFLD mice.•CD147 reduces liver autophagy and alters the AKT/mTOR signaling pathway in high-fat-diet-induced NAFLD mice.
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