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1.
Cardiovasc Res ; 2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31782769

RESUMO

AIMS: Overactivated B cells secrete pathological antibodies, which in turn accelerate the formation of abdominal aortic aneurysms (AAAs). Hyperhomocysteinemia (HHcy) aggravates AAA in mice; however, the underlying mechanisms remain largely elusive. In this study, we further investigated whether homocysteine (Hcy)-activated B cells produce antigen-specific antibodies that ultimately contribute to AAA formation. METHODS AND RESULTS: ELISA assays showed that HHcy induced the secretion of anti-beta 2 glycoprotein I (anti-ß2GPI) antibody from B cells both in vitro and in vivo. Mechanistically, Hcy increased the accumulation of various lipid metabolites in B cells tested by LC-MS/MS, which contributed to elevated anti-ß2GPI IgG secretion. By using the Toll-like receptor 4 (TLR4)-specific inhibitor TAK-242 or TLR4-deficient macrophages, we found that culture supernatants from Hcy-activated B cells and HHcy plasma IgG polarized inflammatory macrophages in a TLR4-dependent manner. In addition, HHcy markedly increased the incidence of elastase- and CaPO4-induced AAA in male BALB/c mice, which was prevented in µMT mice. To further determine the importance of IgG in HHcy-aggravated AAA formation, we purified plasma IgG from HHcy or control mice and then transferred the IgG into µMT mice, which were subsequently subjected to elastase- or CaPO4-induced AAA. Compared with µMT mice that received plasma IgG from control mice, µMT mice that received HHcy plasma IgG developed significantly exacerbated elastase- or CaPO4-induced AAA accompanied by increased elastin degradation, MMP2/9 expression, and anti-ß2GPI IgG deposition in vascular lesions, as shown by immunofluorescence histochemical staining. CONCLUSION: Our findings reveal a novel mechanism by which Hcy-induced B cell-derived pathogenic anti-ß2GPI IgG might, at least in part, contribute to HHcy-aggravated chronic vascular inflammation and AAA formation. TRANSLATIONAL PERSPECTIVE: HHcy is an independent risk factor for cardiovascular diseases in which B cell secretion of IgG antibodies play a key role. However, whether the antigen specific antibody production is changed during HHcy-accelerated AAA remains unclear. Our results provided the first evidence supporting the important role of activated B cell-derived anti-ß2GPI IgG in HHcy-aggravated chronic vascular inflammation and AAA formation. It sheds new light on understanding pathogenesis of HHcy-accelerated AAA. In addition, anti-ß2GPI IgG may be a potential diagnostic marker and therapeutic target for HHcy-related vascular injury.

2.
FASEB J ; 33(11): 12780-12799, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31480861

RESUMO

Intercellular communication between lymphocytes plays a fundamental role in numerous immune responses. Previously, we demonstrated that hyperhomocysteinemia (HHcy) induced T cell intracellular glycolytic-lipogenic reprogramming and IFN-γ secretion via pyruvate kinase muscle isozyme 2 (PKM2) to accelerate atherosclerosis. Usually, B cells partially obtain help from T cells in antibody responses. However, whether PKM2 activation in T cells regulates B cell antibody production is unknown. Extracellular vesicles (EVs) are important cellular communication vehicles. Here, we found that PKM2 activator TEPP46-stimulated T-cell-derived EVs promoted B-cell IgG secretion. Conversely, EVs secreted from PKM2-null T cells were internalized into B cells and markedly inhibited B-cell mitochondrial programming, activation, and IgG production. Mechanistically, lipidomics analyses showed that increased ceramides in PKM2-activated T-cell EVs were mainly responsible for enhanced B cell IgG secretion induced by these EVs. Finally, quantum dots (QDs) were packaged with PKM2-null T cell EVs and anti-CD19 antibody to exert B-cell targeting and inhibit IgG production, eventually ameliorating HHcy-accelerated atherosclerosis in vivo. Thus, PKM2-mediated EV ceramides in T cells may be an important cargo for T-cell-regulated B cell IgG production, and QD-CD19-PKM2-null T cell EVs hold high potential to treat B cell overactivation-related diseases.-Yang, J., Dang, G., Lü, S., Liu, H., Ma, X., Han, L., Deng, J., Miao, Y., Li, X., Shao, F., Jiang, C., Xu, Q., Wang, X., Feng, J. T-cell-derived extracellular vesicles regulate B-cell IgG production via pyruvate kinase muscle isozyme 2.

3.
Biomed Res Int ; 2016: 6701249, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27689087

RESUMO

rLj-RGD3 is a 14.5 kDa recombinant protein with 3 RGD (Arg-Gly-Asp) motifs from the salivary gland secretions of Lampetra japonica, which is a histidine-rich and arginine-rich protein. Previous reports indicated that rLj-RGD3 has typical functions of RGD-toxin protein, such as platelet aggregation suppression tumour metastasis and angiogenesis inhibition. Because histidine and arginine have cerebral ischemia-reperfusion and neuroprotective functions, we investigated whether rLj-RGD3 has such activities and studied the mechanism. The effects of rLj-RGD3 on neuroprotection and antiapoptosis were determined. The expression level of focal adhesion kinase (FAK), p-FAK, Caspase-3, and Bcl-2 after oxygen-glucose deprivation and reperfusion (OGD-R) was examined. The viability of PC12 cells incubated with rLj-RGD3 at high concentrations (16 µmol/L) increased significantly due to its ability to protect the cells from apoptosis after OGD-R-induced injury. Furthermore, rLj-RGD3 attenuated the damage due to OGD-R. Most of the PC12 cells were apoptotic after OGD-R. In contrast, the number of apoptotic PC12 cells was significantly decreased in the group treated with a high-dose of rLj-RGD3. In addition, rLj-RGD3 activated FAK and p-FAK protein. rLj-RGD3 inhibited Caspase-3 and upregulated Bcl-2 protein expression in PC12 cells after OGD-R. The study provides the first evidence for neuroprotective effects of rLj-RGD3 in ischemic injury that may be partly mediated through inhibition of Caspase-3 and upregulation of Bcl-2, FAK, and p-FAK protein expression.

4.
Biochimie ; 119: 183-91, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26549486

RESUMO

PURPOSE: The objective of this study is to investigate the antiproliferative activity and mechanism of integrin-binding rLj-RGD4 in a Hep-2 human laryngeal carcinoma-bearing nude mouse model. METHODS: Human laryngeal squamous carcinoma cells (Hep-2) were inoculated subcutaneously into the axilla of nude mice to generate a Hep-2 human laryngeal carcinoma-bearing nude mouse model. When the Hep-2 xenograft model was successfully established, the animals were randomly separated into five groups. Three groups were treated with different dosages of rLj-RGD4. Cisplatin was administered to the positive control group, and normal saline (NaCl) was administered to the negative control group for 3 weeks. The body weights and the survival of the nude mice were evaluated, and the volumes and weights of the solid tumours were measured. The mechanism underlying rLj-RGD4 inhibition of tumour growth in transplanted Hep-2 human laryngeal carcinoma-bearing nude mice was evaluated by haematoxylin-eosin (HE) staining, terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL), measurement of intratumoural microvessel density (MVD), Western blotting, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR). RESULTS: The tumour volumes and weights of the treatment groups were reduced compared with the model group, and survival times were improved by rLj-RGD4 treatment in Hep-2 human laryngeal carcinoma-bearing nude mice. The number of apoptotic Hep-2 human cells and intratumoural MVD significantly decreased after the administration of rLj-RGD4. In the xenograft tissue of animals treated with rLj-RGD4, FAK, PI3K, and Akt expression was unaltered, whereas P-FAK, P-PI3K, Bcl-2, P-Akt, and VEGF levels were down-regulated. In addition, activated caspase-3, activated caspase-9, and Bax levels were up-regulated. CONCLUSION: rLj-RGD4 exhibits potent in vivo activity and inhibits the growth of transplanted Hep-2 human laryngeal carcinoma cells in a nude mouse model. Thus, these results indicate that the recombinant RGD toxin protein rLj-RGD4 may serve as a potent clinical therapy for human laryngeal squamous carcinoma.


Assuntos
Inibidores da Angiogênese/uso terapêutico , Apoptose/efeitos dos fármacos , Carcinoma de Células Escamosas/tratamento farmacológico , Proteínas de Peixes/uso terapêutico , Venenos de Peixe/química , Lampreias , Neoplasias Laríngeas/tratamento farmacológico , Toxinas Marinhas/uso terapêutico , Motivos de Aminoácidos , Inibidores da Angiogênese/administração & dosagem , Inibidores da Angiogênese/efeitos adversos , Inibidores da Angiogênese/química , Animais , Peso Corporal/efeitos dos fármacos , Carcinoma de Células Escamosas/irrigação sanguínea , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proteínas de Peixes/administração & dosagem , Proteínas de Peixes/efeitos adversos , Proteínas de Peixes/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/irrigação sanguínea , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/metabolismo , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Neoplasias Laríngeas/irrigação sanguínea , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patologia , Toxinas Marinhas/administração & dosagem , Toxinas Marinhas/efeitos adversos , Toxinas Marinhas/genética , Camundongos Nus , Microvasos/efeitos dos fármacos , Microvasos/patologia , Oligopeptídeos/química , Distribuição Aleatória , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/efeitos adversos , Proteínas Recombinantes/química , Proteínas Recombinantes/uso terapêutico , Carcinoma de Células Escamosas de Cabeça e Pescoço , Análise de Sobrevida , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Oncol Rep ; 33(3): 1358-64, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25592110

RESUMO

Recombinant hirudin (rH) is a highly potent and specific inhibitor of thrombin, and has been shown to inhibit the growth and metastasis of several types of cancers in experimental tumor models. The objective of this study was to evaluate the antitumor effects and explore the underlying mechanisms of rH in Hep-2 human laryngeal carcinoma (LC) cells. Hep-2 cells were treated with various concentrations of rH for 24 h. The cell viability was evaluated by a water-soluble tetrazolium salt (WST) assay. The adhesion ability of the cells was evaluated by cell adhesion to fibronectin. Cell migration and invasion were measured with the Boyden chamber assay. Cell apoptosis was detected by Hoechst 33324 fluorescence staining. A chicken chorioallantoic membrane (CAM) assay was used to assess the effects of rH on angiogenesis in vivo. Western blotting was used to detect the expression levels of vascular endothelial growth factor receptor (VEGF-R), focal adhesion kinase (FAK), Bcl-2-associated agonist of cell death (Bad) and B-cell CLL/lymphoma 2 (Bcl-2) proteins. rH significantly inhibited the cell viability and induced apoptosis in LC Hep-2 cells in a dose-dependent manner, as compared with phosphate-buffered saline (PBS) as control. These results were accompanied by a decrease in the anti-apoptotic protein Bcl-2 and an increase in the pro-apoptotic protein Bad. Moreover, rH dose-dependently inhibited the adhesion, migration and invasion of the Hep-2 cells, compared to the vehicle PBS. In addition, rH robustly suppressed angiogenesis in the CAM assay. Importantly, the expression of adhesion and angiogenesis-associated proteins FAK and VEGF-R was significantly downregulated by rH in a dose-dependent manner. The present findings demonstrate that rH exerts antitumor effects in Hep-2 human laryngeal cancer cells via multiple mechanisms and suggests that targeting thrombin by rH is a potential strategy for the treatment of LC.


Assuntos
Antitrombinas/farmacologia , Hirudinas/farmacologia , Neoplasias Laríngeas/tratamento farmacológico , Neoplasias Laríngeas/patologia , Proteínas Recombinantes/farmacologia , Animais , Apoptose/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Embrião de Galinha , Fibronectinas/metabolismo , Quinase 1 de Adesão Focal/biossíntese , Humanos , Invasividade Neoplásica/patologia , Neovascularização Patológica/induzido quimicamente , Proteínas Proto-Oncogênicas c-bcl-2/biossíntese , Receptores de Fatores de Crescimento do Endotélio Vascular/biossíntese , Trombina/antagonistas & inibidores , Proteína de Morte Celular Associada a bcl/biossíntese
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