RESUMO
Intestinal barrier immunity is essential for controlling gut microbiota without eliciting harmful immune responses, while its defect contributes to the breakdown of intestinal homeostasis and colitis development. Chemerin, which is abundantly expressed in barrier tissues, has been demonstrated to regulate tissue inflammation via CMKLR1, its functional receptor. Several studies have reported the association between increased expression of chemerin-CMKLR1 and disease severity and immunotherapy resistance in inflammatory bowel disease (IBD) patients. However, the pathophysiological role of endogenous chemerin-CMKLR1 signaling in intestinal homeostasis remains elusive. We herein demonstrated that deficiency of chemerin or intestinal epithelial cell (IEC)-specific CMKLR1 conferred high susceptibility to microbiota-driven neutrophilic colon inflammation and subsequent tumorigenesis in mice following epithelial injury. Unexpectedly, we found that lack of chemerin-CMKLR1 signaling specifically reduced expression of lactoperoxidase (LPO), a peroxidase that is predominantly expressed in colonic ECs and utilizes H2O2 to oxidize thiocyanates to the antibiotic compound, thereby leading to the outgrowth and mucosal invasion of gram-negative bacteria and dysregulated CXCL1/2-mediated neutrophilia. Importantly, decreased LPO expression was causally linked to aggravated microbiota-driven colitis and associated tumorigenesis, as LPO supplementation could completely rescue such phenotypes in mice deficient in epithelial chemerin-CMKLR1 signaling. Moreover, epithelial chemerin-CMKLR1 signaling is necessary for early host defense against bacterial infection in an LPO-dependent manner. Collectively, our study reveals that the chemerin-CMKLR1/LPO axis represents an unrecognized immune mechanism that potentiates epithelial antimicrobial defense and restricts harmful colonic neutrophilia and suggests that LPO supplementation may be beneficial for microbiota dysbiosis in IBD patients with a defective innate antimicrobial mechanism.
Assuntos
Carcinogênese , Quimiocinas , Colite , Colo , Microbioma Gastrointestinal , Peptídeos e Proteínas de Sinalização Intercelular , Lactoperoxidase , Receptores de Quimiocinas , Animais , Carcinogênese/imunologia , Transformação Celular Neoplásica , Quimiocinas/genética , Quimiocinas/metabolismo , Colite/imunologia , Colite/microbiologia , Colo/imunologia , Colo/microbiologia , Peróxido de Hidrogênio/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiologia , Lactoperoxidase/metabolismo , Camundongos , Neutrófilos/imunologia , Receptores de Quimiocinas/genética , Receptores de Quimiocinas/metabolismoRESUMO
Desmoplasia is a hallmark of intrahepatic cholangiocarcinoma (ICC), which constitutes a barrier to infiltration of lymphocyte, but not myeloid cells. Given that dense desmoplastic stroma has been reported to be a barrier to infiltration of lymphocyte, but not myeloid cells. We here investigated whether fibroblastic FAP influenced ICC progression via non-T cell-related immune mechanisms. We demonstrated fibroblastic FAP expression was critical for STAT3 activation and CCL2 production, and ICC-CAFs were the primary source of CCL2 in human ICC microenvironment by using ICC-Fbs from six ICC patients. Fibroblastic knockdown of FAP significantly impaired the ability of ICC-CAFs to promote ICC growth, MDSCs infiltration and angiogenesis, which was restored by adding exogenous CCL2. Furthermore, interestingly, the tumor-promoting effect of fibroblastic FAP is dependent on MDSCs via secretion of CCL2, as depletion of Gr-1+ cells reversed the restoring effects of exogenous CCL2 on tumor growth and angiogenesis. In vitro migration assay confirmed that exogenous CCL2 could rescue the impaired ability of ICC-Fbs to attract Gr-1+ cells caused by fibroblastic FAP knockdown. In contrast, fibroblastic FAP knockdown had no effect on ICC cell proliferation and apoptotic resistance. Depletion MDSCs by anti-Gr-1 monoclonal antibody in subcutaneous transplanted tumor model abrogated tumor promotion by ICC-CAFs suggested that the pro-tumor function of Fibroblastic FAP relied on MDSCs. Mechanical, flow cytometry and chamber migration assay were conducted to find Fibroblastic FAP was required by the ability of ICC-CAFs to promote MDSC migration directly. Moreover, fibroblastic FAP knockdown had no effect on cell proliferation and apoptotic resistance. Here, we revealed the T-cell independent mechanisms underlying the ICC-promoting effect of fibroblastic FAP by attracting MDSCs via CCL2, which was mainly attributed to the ability of FAP to attract MDSCs and suggests that specific targeting fibroblastic FAP may represent a promising therapeutic strategy against ICC.
Assuntos
Neoplasias dos Ductos Biliares/etiologia , Neoplasias dos Ductos Biliares/metabolismo , Colangiocarcinoma/etiologia , Colangiocarcinoma/metabolismo , Gelatinases/genética , Proteínas de Membrana/genética , Células Supressoras Mieloides/metabolismo , Serina Endopeptidases/genética , Animais , Antígenos Ly/metabolismo , Apoptose/genética , Neoplasias dos Ductos Biliares/patologia , Linhagem Celular Tumoral , Movimento Celular/genética , Proliferação de Células , Colangiocarcinoma/patologia , Modelos Animais de Doenças , Endopeptidases , Fibroblastos/metabolismo , Gelatinases/metabolismo , Técnicas de Silenciamento de Genes , Xenoenxertos , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Células Supressoras Mieloides/imunologia , Fator de Transcrição STAT3/metabolismo , Serina Endopeptidases/metabolismo , Microambiente Tumoral/genéticaRESUMO
Enhanced gut permeability due to dysregulated epithelial tight junction is often associated with inflammatory bowel diseases (IBD), which have a greater risk for developing colorectal cancer. STAT6 activation was detected in inflamed colonic epithelium of active IBD patients, suggesting a role of epithelial STAT6 in colitis development. Here, we demonstrated that non-hematopoietic STAT6, but not hematopoietic STAT6, triggered DSS-induced colitis and subsequent tumorigenesis. This could be due to the enhancing-effect of STAT6 on gut permeability and microbiota translocation via interruption of epithelial tight junction integrity. Mechanistically, long-myosin light-chain kinase (MLCK1) was identified as a target of STAT6, leading to epithelial tight junction dysfunction and microbiota-driven colitis. Furthermore, neutralization of IL-13, which was primarily derived from type 2 innate lymphoid cells (ILC2) in a microbiota-dependent way, inhibited epithelial STAT6 activation and improved gut permeability and DSS-induced colitis. Importantly, pharmacological inhibition of STAT6 reduces murine intestinal tumor formation, and tumoral p-STAT6 levels positively correlated to the clinical stage and poor prognosis of human colorectal cancer. Thus, our study reveals a direct role of STAT6 in the disruption of epithelial tight junction integrity and colitis development, and suggests STAT6 as a potential therapeutic and prophylactic target for IBD and colitis-associated cancer.
Assuntos
Colite/metabolismo , Colo/metabolismo , Neoplasias do Colo/metabolismo , Mucosa Intestinal/metabolismo , Fator de Transcrição STAT6/metabolismo , Junções Íntimas/metabolismo , Animais , Translocação Bacteriana , Células CACO-2 , Colite/genética , Colite/microbiologia , Colite/patologia , Colo/efeitos dos fármacos , Colo/microbiologia , Colo/patologia , Neoplasias do Colo/microbiologia , Neoplasias do Colo/patologia , Neoplasias do Colo/prevenção & controle , Modelos Animais de Doenças , Impedância Elétrica , Microbioma Gastrointestinal , Genes APC , Humanos , Interleucina-13/metabolismo , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/microbiologia , Mucosa Intestinal/patologia , Linfócitos/metabolismo , Linfócitos/patologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Quinase de Cadeia Leve de Miosina/genética , Quinase de Cadeia Leve de Miosina/metabolismo , Permeabilidade , Fosforilação , Pirimidinas/farmacologia , Fator de Transcrição STAT6/antagonistas & inibidores , Fator de Transcrição STAT6/deficiência , Fator de Transcrição STAT6/genética , Transdução de Sinais , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/microbiologia , Junções Íntimas/patologia , Técnicas de Cultura de TecidosRESUMO
Cisplatin is an effective chemotherapeutic agent and widely used in treatment of various solid organ malignancies, including head and neck, ovarian, and testicular cancers. However, the induction of acute kidney injury (AKI) is one of its main side effects. Leukotriene B4 receptor 1 (BLT1) mediates the majority of physiological effects of leukotriene B4 (LTB4), a potent lipid chemoattractant generated at inflammation sites, but the role of the LTB4-BLT1 axis in cisplatin-induced AKI remains unknown. Here we found upregulated LTB4 synthesis and BLT1 expression in the kidney after cisplatin administration. Cisplatin was found to directly upregulate gene expression of leukotriene A4 hydrolase and stimulate LTB4 production in renal tubular epithelial cells. Reduced kidney structural/functional damage, inflammation, and apoptosis were observed in BLT1-/- mice, as well as in wild-type mice treated with the LTA4H inhibitor SC-57461A and the BLT1 antagonist U-75302. Neutrophils were likely the target of this pathway, as BLT1 absence induced a significant decrease in infiltrating neutrophils in the kidney. Adoptive transfer of neutrophils from wild-type mice restored kidney injury in BLT1-/- mice following cisplatin challenge. Thus, the LTB4-BLT1 axis contributes to cisplatin-induced AKI by mediating kidney recruitment of neutrophils, which induce inflammation and apoptosis in the kidney. Hence, the LTB4-BLT1 axis could be a potential therapeutic target in cisplatin-induced AKI.
Assuntos
Injúria Renal Aguda/metabolismo , Quimiotaxia de Leucócito , Cisplatino , Rim/metabolismo , Leucotrieno B4/metabolismo , Infiltração de Neutrófilos , Neutrófilos/metabolismo , Receptores do Leucotrieno B4/metabolismo , Injúria Renal Aguda/induzido quimicamente , Injúria Renal Aguda/patologia , Injúria Renal Aguda/prevenção & controle , Transferência Adotiva , Animais , Apoptose , Linhagem Celular , Quimiotaxia de Leucócito/efeitos dos fármacos , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/metabolismo , Predisposição Genética para Doença , Humanos , Rim/efeitos dos fármacos , Rim/patologia , Antagonistas de Leucotrienos/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos/efeitos dos fármacos , Neutrófilos/efeitos dos fármacos , Neutrófilos/patologia , Neutrófilos/transplante , Fenótipo , Receptores do Leucotrieno B4/antagonistas & inibidores , Receptores do Leucotrieno B4/deficiência , Receptores do Leucotrieno B4/genética , Transdução de Sinais , Fatores de TempoRESUMO
Cancer-associated fibroblasts (CAF) are components of the tumor microenvironment whose contributions to malignant progression are not fully understood. Here, we show that the fibroblast activation protein (FAP) triggers induction of a CAF subset with an inflammatory phenotype directed by STAT3 activation and inflammation-associated expression signature marked by CCL2 upregulation. Enforcing FAP expression in normal fibroblasts was sufficient to endow them with an inflammatory phenotype similar to FAP(+)CAFs. We identified FAP as a persistent activator of fibroblastic STAT3 through a uPAR-dependent FAK-Src-JAK2 signaling pathway. In a murine liver tumor model, we found that FAP(+)CAFs were a major source of CCL2 and that fibroblastic STAT3-CCL2 signaling in this setting promoted tumor growth by enhancing recruitment of myeloid-derived suppressor cells (MDSC). The CCL2 receptor CCR2 was expressed on circulating MDSCs in tumor-bearing subjects and FAP(+)CAF-mediated tumor promotion and MDSC recruitment was abrogated in Ccr2-deficient mice. Clinically, we observed a positive correlation between stromal expression of FAP, p-STAT3, and CCL2 in human intrahepatic cholangiocarcinoma, a highly aggressive liver cancer with dense desmoplastic stroma, where elevated levels of stromal FAP predicted a poor survival outcome. Taken together, our results showed how FAP-STAT3-CCL2 signaling in CAFs was sufficient to program an inflammatory component of the tumor microenvironment, which may have particular significance in desmoplasia-associated cancers. Cancer Res; 76(14); 4124-35. ©2016 AACR.
Assuntos
Fibroblastos Associados a Câncer/fisiologia , Quimiocina CCL2/fisiologia , Gelatinases/fisiologia , Tolerância Imunológica , Proteínas de Membrana/fisiologia , Fator de Transcrição STAT3/fisiologia , Serina Endopeptidases/fisiologia , Transdução de Sinais/fisiologia , Microambiente Tumoral , Animais , Movimento Celular , Endopeptidases , Feminino , Proteína-Tirosina Quinases de Adesão Focal/fisiologia , Janus Quinase 2/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Receptores de Ativador de Plasminogênio Tipo Uroquinase/fisiologiaRESUMO
Thymic stromal lymphopoietin (TSLP) has recently been suggested in several epithelial cancers, either pro-tumor or anti-tumor. However, the role of TSLP in colon cancer remains unknown. We here found significantly decreased TSLP levels in tumor tissues compared with tumor-surrounding tissues of patients with colon cancer and TSLP levels negatively correlated with the clinical staging score of colon cancer. TSLPR, the receptor of TSLP, was expressed in all three colon cancer cell lines investigated and colon tumor tissues. The addition of TSLP significantly enhanced apoptosis of colon cancer cells in a TSLPR-dependent manner. Interestingly, TSLP selectively induced the apoptosis of colon cancer cells, but not normal colonic epithelial cells. Furthermore, we demonstrated that TSLP induced JNK and p38 activation and initiated apoptosis mainly through the extrinsic pathway, as caspase-8 inhibitor significantly reversed the apoptosis-promoting effect of TSLP. Finally, using a xenograft mouse model, we demonstrated that peritumoral administration of TSLP greatly reduced tumor growth accompanied with extensive tumor apoptotic response, which was abolished by tumor cell-specific knockdown of TSLPR. Collectively, our study reveals a novel anti-tumor effect of TSLP via direct promotion of the apoptosis of colon cancer cells, and suggests that TSLP could be of value in treating colon cancer.
Assuntos
Adenoma/patologia , Apoptose/efeitos dos fármacos , Neoplasias do Colo/patologia , Citocinas/farmacologia , Animais , Apoptose/fisiologia , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Humanos , Camundongos , Camundongos Nus , Receptores de Citocinas/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Linfopoietina do Estroma do TimoRESUMO
Leukotriene B4 (LTB4 ) is a lipid mediator that is rapidly generated in inflammatory sites, and its functional receptor, BLT1, is mostly expressed on immune cells. Contact dermatitis is a common inflammatory skin disease characterized by skin oedema and abundant inflammatory infiltrates, primarily including neutrophils and CD8(+) T cells. The role of the LTB4 -BLT1 axis in contact dermatitis remains largely unknown. In this study, we found up-regulated gene expression of 5-lipoxygenase and leukotriene A4 hydrolase, two critical enzymes for LTB4 synthesis, BLT1 and elevated LTB4 levels in skin lesions of oxazolone (OXA)-induced contact dermatitis. BLT1 deficiency or blockade of LTB4 and BLT1 by the antagonists, bestatin and U-75302, respectively, in the elicitation phase caused significant decreases in ear swelling and skin-infiltrating neutrophils and CD8(+) T cells, which was accompanied by significantly reduced skin expression of CXCL1, CXCL2, interferon-γ and interleukin-1ß. Furthermore, neutrophil depletion during the elicitation phase of OXA-induced contact dermatitis also caused significant decreases in ear swelling and CD8(+) T-cell infiltration accompanied by significantly decreased LTB4 synthesis and gene expression of CXCL2, interferon-γ and interleukin-1ß. Importantly, subcutaneous injection of exogenous LTB4 restored the skin infiltration of CD8(+) T cells in neutrophil-depleted mice following OXA challenge. Collectively, our results demonstrate that the LTB4 -BLT1 axis contributes to OXA-induced contact dermatitis by mediating skin recruitment of neutrophils, which are a major source of LTB4 that sequentially direct CD8(+) T-cell homing to OXA-challenged skin. Hence, LTB4 and BLT1 could be potential therapeutic targets for the treatment of contact dermatitis.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Dermatite de Contato/imunologia , Leucotrieno B4/imunologia , Neutrófilos/imunologia , Receptores do Leucotrieno B4/imunologia , Animais , Araquidonato 5-Lipoxigenase/biossíntese , Quimiocina CXCL1/biossíntese , Quimiocina CXCL2/biossíntese , Dermatite de Contato/tratamento farmacológico , Epóxido Hidrolases/biossíntese , Álcoois Graxos/farmacologia , Feminino , Glicóis/farmacologia , Inflamação/tratamento farmacológico , Inflamação/imunologia , Interferon gama/biossíntese , Interleucina-1beta/biossíntese , Leucina/análogos & derivados , Leucina/farmacologia , Leucotrieno B4/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Oxazolona , Receptores do Leucotrieno B4/antagonistas & inibidores , Receptores do Leucotrieno B4/biossíntese , Pele/citologia , Pele/imunologiaRESUMO
Chemerin is present in various inflammatory sites and is closely involved in tissue inflammation. Recent studies have demonstrated that chemerin treatment can cause either anti-inflammatory or pro-inflammatory effects according to the disease model being investigated. Elevated circulating chemerin was recently found in patients with inflammatory bowel disease (IBD); however, the role of chemerin in intestinal inflammation remains unknown. In this study, we demonstrated that the administration of exogenous chemerin (aa17-156) aggravated the severity of dextran sulfate sodium (DSS)-induced colitis, which was characterized by higher clinical scores, extensive mucosal damage and significantly increased local and systemic production of pro-inflammatory cytokines, including IL-6, TNF-α and interferon (IFN-γ). Interestingly, chemerin did not appear to influence the magnitudes of inflammatory infiltrates in the colons, but did result in significantly decreased colonic expression of M2 macrophage-associated genes, including Arginase 1 (Arg-1), Ym1, FIZZ1 and IL-10, following DSS exposure, suggesting an impaired M2 macrophage skewing in vivo. Furthermore, an in vitro experiment showed that the addition of chemerin directly suppressed M2 macrophage-associated gene expression and STAT6 phosphorylation in IL-4-stimulated macrophages. Significantly elevated chemerin levels were found in colons from DSS-exposed mice and from ulcerative colitis (UC) patients and appeared to positively correlate with disease severity. Moreover, the in vivo administration of neutralizing anti-chemerin antibody significantly improved intestinal inflammation following DSS exposure. Taken together, our findings reveal a pro-inflammatory role for chemerin in DSS-induced colitis and the ability of chemerin to suppress the anti-inflammatory M2 macrophage response. Our study also suggests that upregulated chemerin in inflamed colons may contribute to the pathogenesis of IBD.
Assuntos
Quimerina 1/administração & dosagem , Colite Ulcerativa/imunologia , Colite/imunologia , Colo/imunologia , Macrófagos/imunologia , Fragmentos de Peptídeos/administração & dosagem , Animais , Arginase/genética , Arginase/metabolismo , Diferenciação Celular/genética , Células Cultivadas , Colite/induzido quimicamente , Citocinas/metabolismo , Sulfato de Dextrana/imunologia , Modelos Animais de Doenças , Progressão da Doença , Regulação para Baixo , Feminino , Humanos , Mediadores da Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/genética , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Lectinas/genética , Lectinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fator de Transcrição STAT6/metabolismo , beta-N-Acetil-Hexosaminidases/genética , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
This study investigated the effects of seahorse (Hippocampus spp.) extracts in a rat model of benign prostatic hyperplasia (BPH) and mouse model of oligospermatism. Compared to the sham operated group, castration and testosterone induced BPH, indicated by increased penile erection latency; decreased penis nitric oxide synthase (NOS) activity; reduced serum acid phosphatase (ACP) activity; increased prostate index; and epithelial thickening, increased glandular perimeter, increased proliferating cell nuclear antigen (PCNA) index and upregulation of basic fibroblast growth factor (bFGF) in the prostate. Seahorse extracts significantly ameliorated the histopathological changes associated with BPH, reduced the latency of penile erection and increased penile NOS activity. Administration of seahorse extracts also reversed epididymal sperm viability and motility in mice treated with cyclophosphamide (CP). Seahorse extracts have potential as a candidate marine drug for treating BPH without inducing the side effects of erectile dysfunction (ED) or oligospermatism associated with the BPH drug finasteride.