RESUMO
Regulated neural-metabolic-inflammatory responses are essential for maintaining physiological homeostasis. However, the molecular machinery that coordinates neural, metabolic, and inflammatory responses is largely unknown. Here, we show that semaphorin 6D (SEMA6D) coordinates anxiogenic, metabolic, and inflammatory outputs from the amygdala by maintaining synaptic homeostasis. Using genome-wide approaches, we identify SEMA6D as a pleiotropic gene for both psychiatric and metabolic traits in human. Sema6d deficiency increases anxiety in mice. When fed a high-fat diet, Sema6d-/- mice display attenuated obesity and enhanced myelopoiesis compared with control mice due to higher sympathetic activity via the ß3-adrenergic receptor. Genetic manipulation and spatial and single-nucleus transcriptomics reveal that SEMA6D in amygdalar interneurons is responsible for regulating anxiogenic and autonomic responses. Mechanistically, SEMA6D is required for synaptic maturation and γ-aminobutyric acid transmission. These results demonstrate that SEMA6D is important for the normal functioning of the neural circuits in the amygdala, coupling emotional, metabolic, and inflammatory responses.
RESUMO
Progressive pulmonary fibrosis (PPF), defined as the worsening of various interstitial lung diseases (ILDs), currently lacks useful biomarkers. To identify novel biomarkers for early detection of patients at risk of PPF, we performed a proteomic analysis of serum extracellular vesicles (EVs). Notably, the identified candidate biomarkers were enriched for lung-derived proteins participating in fibrosis-related pathways. Among them, pulmonary surfactant-associated protein B (SFTPB) in serum EVs could predict ILD progression better than the known biomarkers, serum KL-6 and SP-D, and it was identified as an independent prognostic factor from ILD-gender-age-physiology index. Subsequently, the utility of SFTPB for predicting ILD progression was evaluated further in 2 cohorts using serum EVs and serum, respectively, suggesting that SFTPB in serum EVs but not in serum was helpful. Among SFTPB forms, pro-SFTPB levels were increased in both serum EVs and lungs of patients with PPF compared with those of the control. Consistently, in a mouse model, the levels of pro-SFTPB, primarily originating from alveolar epithelial type 2 cells, were increased similarly in serum EVs and lungs, reflecting pro-fibrotic changes in the lungs, as supported by single-cell RNA sequencing. SFTPB, especially its pro-form, in serum EVs could serve as a biomarker for predicting ILD progression.
Assuntos
Biomarcadores , Progressão da Doença , Vesículas Extracelulares , Fibrose Pulmonar , Proteína B Associada a Surfactante Pulmonar , Vesículas Extracelulares/metabolismo , Humanos , Animais , Biomarcadores/sangue , Camundongos , Masculino , Feminino , Fibrose Pulmonar/sangue , Fibrose Pulmonar/metabolismo , Fibrose Pulmonar/patologia , Proteína B Associada a Surfactante Pulmonar/sangue , Proteína B Associada a Surfactante Pulmonar/metabolismo , Pessoa de Meia-Idade , Idoso , Doenças Pulmonares Intersticiais/sangue , Doenças Pulmonares Intersticiais/diagnóstico , Doenças Pulmonares Intersticiais/patologia , Doenças Pulmonares Intersticiais/metabolismo , Pulmão/patologia , Pulmão/metabolismo , Proteômica/métodos , Modelos Animais de Doenças , Prognóstico , Precursores de Proteínas , Proteínas Associadas a Surfactantes PulmonaresRESUMO
Immune checkpoint inhibitors (ICIs) are indicated for a diverse range of cancer types, and characterizing the tumor immune microenvironment is critical for optimizing therapeutic strategies, including ICIs. T cell infiltration and activation status in the tumor microenvironment greatly affects the efficacy of ICIs. Here, we show that semaphorin 6D (Sema6D) forward signaling, which is reportedly involved in coordinating the orientation of cell development and migration as a guidance factor, impaired the infiltration and activation of tumor-specific CD8+ T cells in murine oral tumors. Sema6D expressed by nonhematopoietic cells was responsible for this phenotype. Plexin-A4, a receptor for Sema6D, inhibited T cell infiltration and partially suppressed CD8+ T cell activation and proliferation induced by Sema6D stimulation. Moreover, mouse oral tumors, which are resistant to PD-1-blocking treatment in wild-type mice, showed a response to the treatment in Sema6d-KO mice. Finally, analyses of public data sets of human head and neck squamous cell carcinoma, pan-cancer cohorts, and a retrospective cohort study showed that SEMA6D was mainly expressed by nonhematopoietic cells such as cancer cells, and SEMA6D expression was significantly negatively correlated with CD8A, PDCD1, IFNG, and GZMB expression. Thus, targeting Sema6D forward signaling is a promising option for increasing ICI efficacy.
Assuntos
Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Animais , Humanos , Camundongos , Proliferação de Células , Neoplasias de Cabeça e Pescoço/genética , Estudos Retrospectivos , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Microambiente TumoralRESUMO
Semaphorins were originally identified as guidance molecules in neural development. However, accumulating evidence indicates that 'immune semaphorins' are critically involved in regulating immune cell activation, differentiation, mobility and migration. Semaphorins are also intimately associated with the pathogenesis of allergic diseases including asthma, allergic rhinitis, atopic dermatitis, allergic conjunctivitis, and eosinophilic chronic rhinosinusitis. Interestingly, reflecting their function in positive or negative regulation of immune cells, levels of some semaphorins are increased while others are decreased in patients with allergic diseases. This review presents the pathogenic functions of immune semaphorins in allergic inflammation and discusses the potential use of these molecules as therapeutic targets for allergic diseases.
Assuntos
Asma , Semaforinas , Sinusite , Humanos , Asma/patologia , InflamaçãoRESUMO
BACKGROUND: Mycobacterium obuense (M. obuense) is a rapidly growing mycobacterium (RGM) which has been considered nonpathogenic. Here, we report a case of disseminated non-tuberculous mycobacterial (NTM) infection caused by M. obuense in an immunocompromised patient. CASE PRESENTATION: A 16-year-old boy was referred to our hospital due to acute myeloid leukemia. During the treatment of leukemia, the patient exhibited continuous fever, and diffuse miliary nodules with random distribution were found on chest computed tomography. Repeated examinations of bacterial culture tests revealed sputum and urine samples to be smear-positive for acid-fast bacillus, and blood culture from a peripherally inserted central catheter line showed the growth of NTM. The NTM species was identified as M. obuense by mass spectrometry and confirmed by genome sequencing. Combination therapy with amikacin, rifampicin, azithromycin, and moxifloxacin significantly improved the patient's symptoms and radiological findings. CONCLUSION: We report a case of disseminated NTM infection caused by M. obuense for which combination anti-microbial therapy was effective. An immunocompromised host indwelling catheter is at risk of RGM bloodstream infections. Although relatively rare, M. obuense may be considered as a potential pathogen causing infectious diseases, especially in high-risk patients.
Assuntos
Infecções por Mycobacterium não Tuberculosas , Mycobacterium , Tuberculose , Masculino , Humanos , Adolescente , Micobactérias não Tuberculosas/genética , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Hospedeiro ImunocomprometidoRESUMO
Since the discovery of group 2 innate lymphoid cells (ILC2s) in 2010, subsequent studies have revealed their developmental pathways, mechanisms of activation and regulation, and immunological roles in tissue homeostasis and tissue-specific diseases in various organs. Although ILC2s are known to express tissue-specific features depending on where they reside, how the surrounding environment affects the functions of ILC2s remains to be fully elucidated. Recent histologic analyses revealed that ILC2s resides in specific perivascular regions in peripheral tissues with their function being controlled by the surrounding cells via cytokines, lipid mediators, neurotransmitters, and cell-cell interactions through surface molecules. This review summarizes the interactions between ILC2s and surrounding cells, including epithelial cells, neurons, immune cells, and mesenchymal cells, with the objective of promoting the development of novel diagnostic and therapeutic methods for ILC2-related diseases.
RESUMO
Group 2 innate lymphoid cells (ILC2s) have been implicated in both physiologic tissue remodeling and allergic pathology, yet the niche signaling required for ILC2 properties is poorly understood. Here, we show that an axonal guidance cue semaphorin 6D (Sema6D) plays critical roles in the maintenance of IL-10-producing ILC2s. Sema6d -/- mice exhibit a severe steady-state reduction in ILC2s in peripheral sites such as the lung, visceral adipose tissue, and mesentery. Interestingly, loss of Sema6D results in suppressed alarmin-driven type 2 cytokine production but increased IL-10 production by lung ILC2s both in vitro and in vivo. Consequently, Sema6d -/- mice are resistant to the development of allergic lung inflammation. We further found that lung mesenchymal cells highly express Sema6D, and that niche-derived Sema6D is responsible for these phenotypes through plexin A1. Collectively, these findings suggest that niche-derived Sema6D is implicated in physiological and pathological characteristics of ILC2s.
Assuntos
Imunidade Inata , Semaforinas , Animais , Interleucina-10 , Interleucina-33 , Pulmão/patologia , Linfócitos , Camundongos , Semaforinas/genéticaRESUMO
BACKGROUND: Eosinophilic chronic rhinosinusitis (ECRS) is a subtype of chronic rhinosinusitis. Clinical markers for ECRS disease activity and treatment strategies have not been sufficiently established. Although semaphorins are originally identified as neuronal guidance factors, it is becoming clear that they play key roles in immune regulation and inflammatory diseases. OBJECTIVE: We sought to investigate the pathological functions and therapeutic potential of semaphorin 4D (SEMA4D) in ECRS. METHODS: Serum soluble SEMA4D levels in patients with paranasal sinus diseases were measured by ELISA. The expression of SEMA4D in blood cells and nasal polyp tissues was assessed by flow cytometry and immunohistochemistry, respectively. Generation of soluble SEMA4D was evaluated in matrix metalloproteinase-treated eosinophils. Endothelial cells were stimulated with recombinant SEMA4D, followed by eosinophil transendothelial migration assays. Allergic chronic rhinosinusitis was induced in mice using Aspergillus protease with ovalbumin. The efficacy of treatment with anti-SEMA4D antibody was evaluated histologically and by nasal lavage fluid analysis. RESULTS: Serum soluble SEMA4D levels were elevated in patients with ECRS and positively correlated with disease severity. Tissue-infiltrated eosinophils in nasal polyps from patients with ECRS stained strongly with anti-SEMA4D antibody. Cell surface expression of SEMA4D on eosinophils from patients with ECRS was reduced, which was due to matrix metalloproteinase-9-mediated cleavage of membrane SEMA4D. Soluble SEMA4D induced eosinophil transendothelial migration. Treatment with anti-SEMA4D antibody ameliorated eosinophilic infiltration in sinus tissues and nasal lavage fluid in the ECRS animal model. CONCLUSIONS: Eosinophil-derived SEMA4D aggravates ECRS. Levels of serum SEMA4D reflect disease severity, and anti-SEMA4D antibody has therapeutic potential as a treatment for ECRS.
Assuntos
Antígenos CD/metabolismo , Eosinofilia/metabolismo , Rinite/metabolismo , Semaforinas/metabolismo , Sinusite/metabolismo , Adulto , Animais , Antígenos CD/imunologia , Antígenos CD/farmacologia , Doença Crônica , Eosinofilia/imunologia , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Eosinófilos/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Proteínas Recombinantes/farmacologia , Rinite/imunologia , Semaforinas/imunologia , Semaforinas/farmacologia , Sinusite/imunologia , Migração Transendotelial e Transepitelial/efeitos dos fármacosRESUMO
BACKGROUND: In recent years, the anti-programmed cell death 1 (PD-1) drug pembrolizumab (Keytruda) was approved for treatment of unresectable advanced non-small cell lung cancer (NSCLC) as first- or second-line therapy depending on the clone 22C3-programmed death-ligand 1 (PD-L1) immunohistochemical expression score by the companion diagnostic assay. We herein evaluated 22C3-PD-L1 expression of NSCLC in a single institution experience and compared it with clinicopathologic features. MATERIALS AND METHODS: We assessed 22C3-PD-L1 expressions of 411 patients with NSCLC from our institution, including in past specimens. Programmed death-ligand 1 immunohistochemistry (IHC) testing was performed using the PD-L1 clone 22C3 pharmDx kit (Agilent Technologies/Dako, Carpinteria, CA, USA). Patients were separated into 3 groups with <1% (no expression), 1% to 49% (low expression), or ⩾50% (high expression) positive tumor cells. RESULTS: In all, 137 patients (33%) did not express PD-L1, 155 (38%) showed low expression, and 119 (29%) demonstrated high expression. Archival samples showed lower PD-L1 expression than that of recent samples, and the ratios of no expression case significantly increased by using paraffin blocks embedded particularly in more than 4 years ago. Programmed death-ligand 1 positivity was significantly associated with male sex, smoking, higher tumor grade, squamous cell carcinoma in histologic type, wild-type EGFR, and ALK rearrangement positive. CONCLUSIONS: The rate of 22C3-PD-L1 expression of NSCLC detected in this study was similar to the frequencies of the previous reports, although the ratio of expression case decreased when using old paraffin blocks.
RESUMO
Objective Pleomorphic carcinoma (PC) is a rare pulmonary epithelial malignant tumor with a poor prognosis. The objective of the present study was to investigate the programmed death-ligand 1 (PD-L1) expression in PC and its correlation between the clinicopathological factors and prognosis. Methods Clinical and pathological data of 35 patients with surgically resected PC encountered from 2002 to 2016 at our institution were collected. The PD-L1 expression on tumor cells was evaluated via immunohistochemistry (clone 22C3). We examined the correlation between the PD-L1 expression and patients' clinicopathological factors and their prognosis. Results A high PD-L1 expression (≥50%) was seen in 21 (60%) patients, and parietal-pleural invasion was significantly correlated with a high PD-L1 expression (p=0.012). The 5-year overall survival and relapse-free survival were 68.2% and 43.2%, respectively. Tumor size ≥50 mm (p=0.021), lymph node metastasis (p=0.023), and a high PD-L1 expression (p=0.047) were correlated with a short relapse-free survival. Since lymph node metastasis was an independent risk factor of a poor overall survival (p=0.012), patients with a high PD-L1 expression also tended to have a worse overall survival than those with low levels (p=0.081). Conclusion A high PD-L1 expression is frequently seen in PC. The PD-L1 expression is associated with parietal-pleural invasion and might indicate a poor prognosis.
Assuntos
Adenocarcinoma/patologia , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/metabolismo , Neoplasias Pulmonares/patologia , Adenocarcinoma/diagnóstico , Adenocarcinoma/secundário , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Imuno-Histoquímica , Neoplasias Pulmonares/diagnóstico , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica , Proteínas de Neoplasias/metabolismo , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Pleura/patologia , PrognósticoRESUMO
An aortic mural thrombus (AMT) on a non-atherosclerotic wall is a rare but important cause of arterial thromboembolism. We herein report two cases of AMT in the thoracic aorta. Both showed multiple hypercoagulable factors (case 1: protein S deficiency and positive finding of anti-cardiolipin antibody; case 2: protein C deficiency, gastric cancer, and cisplatin-based chemotherapy) and were successfully treated with anticoagulation. Hypercoagulable states, including malignancy, can influence the formation of AMT; therefore, the accurate assessment of a hypercoagulable condition is necessary when we encounter patients with AMT.
Assuntos
Anticoagulantes/uso terapêutico , Aorta Torácica/fisiopatologia , Doenças da Aorta/tratamento farmacológico , Cardiopatias/complicações , Tromboembolia/complicações , Trombose/tratamento farmacológico , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Resultado do TratamentoRESUMO
BACKGROUND: Pulmonary non-tuberculous mycobacterial disease (PNTM) is a known risk factor for chronic pulmonary aspergillosis (CPA). However, few studies have focused on the prognosis of PNTM-associated CPA. In the present investigation, we aimed to elucidate the clinical course and prognostic factors of CPA in patients with PNTM. METHODS: We retrospectively investigated the medical records of 62 patients with CPA and a history of PNTM who were admitted to Kinki-chuo Chest Medical Center between 2010 and 2015. Co-morbidities, causative microorganisms, radiological findings, and outcomes were evaluated. RESULTS: The patients' median age was 69.5 years, and the median follow-up period was 4.2 years. The major underlying diseases, other than PNTM and CPA, were old pulmonary tuberculosis, chronic obstructive pulmonary disease, and interstitial pneumonia. The most common causative NTM species were Mycobacterium avium complex (MAC; 37 patients; 59.7%) and Mycobacterium kansasii (20 patients; 32.3%). Survival was 83% after 1 year and 61% after 5 years. Use of systemic corticosteroids (hazard ratio: 3.32, 95% confidence interval: 1.23-9.51; P=0.00177) and C-reactive protein levels ≥â¯5.0â¯mg/dL (hazard ratio: 8.96, 95% confidence interval: 2.15-62.9; P=0.0014) at the time of CPA diagnosis were associated with increased over-all mortality. CONCLUSIONS: CPA frequently developed in patients with MAC and M. kansasii PNTM. The treatment course of PNTM was not associated with all-cause mortality. However, systemic corticosteroid use and high CRP levels were negative prognostic factors of CPA in patients with PNTM. Since the prognosis is poor, early diagnosis and treatment of CPA are important in patients with PNTM.
Assuntos
Infecções por Mycobacterium não Tuberculosas/complicações , Aspergilose Pulmonar/etiologia , Tuberculose Pulmonar/complicações , Corticosteroides/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Proteína C-Reativa , Doença Crônica , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/microbiologia , Infecções por Mycobacterium não Tuberculosas/mortalidade , Complexo Mycobacterium avium/patogenicidade , Mycobacterium kansasii/patogenicidade , Prognóstico , Aspergilose Pulmonar/diagnóstico , Estudos Retrospectivos , Fatores de Risco , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/mortalidadeRESUMO
Background: Among Mycobacterium abscessus complex infections, patients with M. abscessus subsp. abscessus (MAA) lung disease are difficult to treat and no standard therapy has been established. Few reports have investigated the drug susceptibility of these strains. We retrospectively investigated how in vitro drug susceptibility testing (DST) of MAA affects the induction of sputum conversion using pharmacotherapy. Methods: Patients with MAA lung disease diagnosed and treated between 2010 and 2014 at our hospital were enrolled and divided into Group A (sputum conversion without relapse within 1 year) and Group B (persistent positive cultured or negative conversion with relapse). MAA was identified in M. abscessus using sequence with genotyping, and DST of MAA was performed. Results: We assessed 23 patients (9 males and 14 females). There were 8 patients in Group A and 15 in Group B. Higher prevalence of susceptible isolates for clarithromycin (CAM) susceptibility on day 14 was noted in Group A than in Group B (P = 0.03) and no significant difference observed in the two groups for other drugs. Conclusions: In vitro DST of MAA, especially CAM susceptibility on day 14, affected the results of negative conversion. No other drugs were found to affect sputum culture negative conversion.
Assuntos
Antibacterianos/farmacologia , Farmacorresistência Bacteriana , Pneumopatias/microbiologia , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium abscessus/isolamento & purificação , Escarro/microbiologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
Objective The incidence of pulmonary nontuberculous mycobacterial (NTM) infections has increased in recent decades. Nevertheless, NTM pleurisy is still a rare disease. The objective of the present study was to elucidate the clinical features and outcomes of NTM pleurisy. Methods A retrospective study was undertaken of consecutive patients whose pleural effusion culture yielded NTM, from 2002 to 2016 at a respiratory hospital in Japan. The clinical features, treatment, and outcomes of these patients were analyzed. Result The 12 patients with NTM pleurisy were predominantly male, with a median age of 69 years (range, 48-93 years). They included eight patients with a history of smoking and six patients with immunosuppressive comorbidities such as malignancy, diabetes mellitus, and conditions requiring steroid administration. Fibrocavitary disease was the most common radiographic feature of these patients, and Mycobacterium avium complex was the most common pathogen. Pneumothorax was complicated in 11 patients. Surgery was performed on seven patients, in addition to thoracic drainage for the treatment of pleurisy and pneumothorax. Three patients died of respiratory failure. Conclusion Pneumothorax is a frequent complication of NTM pleurisy, often making the condition difficult to treat. Surgery at an appropriate time should therefore considered for refractory cases.
Assuntos
Infecções por Mycobacterium não Tuberculosas/microbiologia , Infecções por Mycobacterium não Tuberculosas/terapia , Micobactérias não Tuberculosas/isolamento & purificação , Pleurisia/microbiologia , Pleurisia/terapia , Pneumotórax/microbiologia , Pneumotórax/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Japão , Masculino , Pessoa de Meia-Idade , Infecções por Mycobacterium não Tuberculosas/diagnóstico , Infecções por Mycobacterium não Tuberculosas/fisiopatologia , Pleurisia/etiologia , Pneumotórax/etiologia , Pneumotórax/fisiopatologia , Estudos Retrospectivos , Resultado do TratamentoRESUMO
BACKGROUND/AIM: Although immune checkpoint inhibitors play an important role in the therapy of lung cancer, they are associated with various immune-related adverse events and predictive factors of them are unclear. In this study, we investigated predictive factors of nivolumab-induced hypothyroidism which is one of the adverse events in patients with lung cancer. PATIENTS AND METHODS: Patients with non-small-cell lung cancer who were administered nivolumab at our hospital between December 2015 and May 2016 were retrospectively enrolled. The thyroid-stimulating hormone, free triiodothyronine, free thyroxine, thyroid peroxidase (TPO) antibody, and thyroglobulin antibody levels of each patient were analyzed. RESULTS: Of the 64 patients enrolled, 5 (7.8%) developed hypothyroidism after treatment with nivolumab. The TPO and thyroglobulin antibodies were significantly positive in patients who developed primary hypothyroidism. CONCLUSION: TPO and thyroglobulin antibody levels at baseline may be predictive of hypothyroidism.
Assuntos
Anticorpos Monoclonais/efeitos adversos , Antineoplásicos Imunológicos/efeitos adversos , Carcinoma Pulmonar de Células não Pequenas/complicações , Hipotireoidismo/diagnóstico , Hipotireoidismo/etiologia , Neoplasias Pulmonares/complicações , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Biomarcadores , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Feminino , Humanos , Hipotireoidismo/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Nivolumabe , Prognóstico , Testes de Função TireóideaRESUMO
Insulin resistance and smoking are significant risk factors for cardiac and cerebral vascular diseases. Because vascular smooth muscle cells play a key role in the development and progression of atherosclerosis, we investigated the effect of nicotine on insulin-induced mitogenic signaling in aortic vascular smooth muscle cells isolated from Sprague Dawley rats. RT-PCR revealed the expression of alpha2-7, alpha10, beta1-3, delta, and epsilon subunits of the nicotinic acetylcholine receptor (nAChR) in the cells. Short-term nicotine treatment stimulated phosphorylation of p44/42-MAPK, p38-MAPK, and signal transducer and activator of transcription 3. However, an additive effect of nicotine pretreatment on insulin stimulation was only observed on p44/42-MAPK. The nicotine-induced phosphorylation of p44/42-MAPK and [methyl-(3)H]thymidine incorporation were effectively suppressed by a alpha7-nAChR-selective antagonist, methyllycaconitine, and the phosphorylation of p44/42-MAPK was stimulated by a alpha7-nAChR-specific agonist, GTS21. Furthermore, the phosphorylation was mediated via calmodulin kinase II, Src, and Shc. Interestingly, long-term (48-h) pretreatment with nicotine increased the amount of alpha7-AChR in the plasma membrane and insulin-induced phosphorylation of p44/42-MAPK. These results provide the first evidence that acute exposure to nicotine enhances insulin-induced mitogenesis predominantly by affecting the phosphorylation of p44/42-MAPK and that chronic exposure further augments the insulin signal via up-regulation of alpha7-nAChR, which may be crucial for the development and progression of atherosclerosis in large vessels.
Assuntos
Aorta/metabolismo , Insulina/farmacologia , Mitose/fisiologia , Músculo Liso Vascular/metabolismo , Receptores Nicotínicos/metabolismo , Transdução de Sinais/fisiologia , Animais , Aorta/citologia , Células Cultivadas , DNA/biossíntese , Ativação Enzimática/fisiologia , Humanos , Masculino , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Músculo Liso Vascular/citologia , Miócitos de Músculo Liso/metabolismo , Nicotina/farmacologia , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/fisiologia , Receptor Nicotínico de Acetilcolina alfa7RESUMO
This study provides new perspectives of the unique aspects of platelet-derived growth factor beta-receptor (PDGFR-beta) signaling and biological responses through the establishment of a mutant mouse strain in which two loxP sequences were inserted into the introns of PDGFR-beta genome sequences. Isolation of skin fibroblasts from the mutant mice and Cre recombinase transfection in vitro induced PDGFR-beta gene deletion (PDGFR-betaDelta/Delta). The resultant depletion of the PDGFR-beta protein significantly attenuated platelet-derived growth factor (PDGF)-BB-induced cell migration, proliferation, and protection from H2O2-induced apoptosis of the cultured PDGFR-betaDelta/Delta dermal fibroblasts. PDGF-AA and fetal bovine serum were mitogenic and anti-apoptotic but were unable to induce the migration in PDGFR-beta Delta/Delta fibroblasts. Concerning the PDGF signaling, PDGF-BB-induced phosphorylation of Akt, ERK1/2, and JNK, but not p38, decreased in PDGFR-betaDelta/Delta fibroblasts, but PDGF-AA-induced signaling was not altered. Overexpression of the phospholipid phosphatases, SHIP2 and/or PTEN, inhibited PDGF-BB-induced phosphorylation of Akt and ERK1/2 in PDGFR-betaDelta/Delta fibroblasts but did not affect that of JNK and p38. These results indicate that disruption of distinct PDGFR-beta signaling pathways in PDGFR-betaDelta/Delta dermal fibroblasts impaired their proliferation and survival, but completely inhibits migratory response, and that PDGF-BB-induced phosphorylation of Akt and ERK1/2 possibly mediated by PDGFR-alpha is regulated, at least in part, by the lipid phosphatases SHIP2 and/or PTEN. Thus, the PDGFR-beta function on dermal fibroblasts appears to be critical in PDGF-BB action for skin wound healing and is clearly distinctive from that of PDGFR-alpha in the ligand-induced biological responses and the underlying properties of cellular signaling.