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1.
Cardiovasc Res ; 2020 Feb 17.
Artigo em Inglês | MEDLINE | ID: mdl-32065618

RESUMO

AIM: Adenosine receptors and extracellular adenosine have been demonstrated to modulate vascular smooth muscle cell (VSMC) proliferation and neointima formation. Adenosine kinase (ADK) is a major enzyme regulating intracellular adenosine levels, but is function in VSMC remains unclear. Here, we investigated the role of ADK in vascular injury-induced smooth muscle proliferation and delineated the mechanisms underlying its action. METHODS AND RESULTS: We found that ADK expression was higher in the neointima of injured vessels and in PDGF-treated VSMCs. Genetic and pharmacological inhibition of ADK was enough to attenuate arterial injury-induced neointima formation due to inhibition of VSMC proliferation. Mechanistically, using infinium methylation assays and bisulfite sequencing, we showed that ADK metabolized the intracellular adenosine and potentiated the transmethylation pathway, then induced the aberrant DNA hypermethylation. Pharmacological inhibition of aberrant DNA hypermethylation increased KLF4 expression and suppressed VSMC proliferation as well as the neointima formation. Importantly, in human femoral arteries, we observed increased ADK expression and DNA hypermethylation as well as decreased KLF4 expression in neointimal VSMCs of stenotic vessels suggesting that our findings in mice are relevant for human disease and may hold translational significance. CONCLUSIONS: Our study unravels a novel mechanism by which ADK promotes VSMC proliferation via inducing aberrant DNA hypermethylation, thereby downregulating KLF4 expression and promoting neointima formation. These findings advance the possibility of targeting ADK as an epigenetic modulator to combat vascular injury. TRANSLATIONAL PERSPECTIVE: Abnormal proliferation of vascular smooth muscle cell (VSMC) is key to abundant occlusive vascular diseases in humans, such as atherosclerosis and intimal hyperplasia associated with restenosis. Adenosine has been shown to combat abnormal smooth muscle proliferation. Here, we demonstrate that increased catabolism of adenosine by adenosine kinase (ADK) promotes abnormal VSMC proliferation. The pathological ADK overexpression in both mice and humans with vascular disease promotes VSMC proliferation via inducing aberrant DNA hypermethylation and KLF4 downregulation. Our study suggests that pharmacological augmentation of endogenous adenosine by targeting ADK represents a promising therapeutic strategy for occlusive vascular diseases.

2.
Immunotherapy ; 12(1): 63-74, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31914839

RESUMO

Aim: To assess the efficacy of dendritic cells-cytokine induced killer (DC-CIK) and natural killer (NK) cell-based immunotherapy in treating the low- and intermediate-risk acute myeloid leukemia. Patients & methods: DC-CIK or NK cells were infused once every 3 months for 2-4 cycles to 85 patients. Results & conclusion: The 5-year overall survival (OS) and relapse-free survival (RFS) rates were 90.5 and 65.2%, respectively. The OS of the very favorable, the favorable and the intermediate-risk groups was 94.4, 86.3 and 93.3% (p = 0.88), and the RFS 83.3, 81.8 and 62.2% (p = 0.14), respectively. The OS and RFS of the 60 patients treated with DC-CIK alternating with NK cells were better than the 25 patients treated with DC-CIK or NK alone (96.5 vs 71.2%; p = 0.003. 79.5 vs 28.9%; p < 0.001).

3.
Artigo em Inglês | MEDLINE | ID: mdl-31917615

RESUMO

RATIONALE: Vascular remodeling, including smooth muscle cell hypertrophy and proliferation, is the key pathological feature of pulmonary arterial hypertension (PAH). Prostaglandin (PG) I2 analogs (baraprost, iloprost, and treprostinil) are effective in the treatment of PAH. Of note, the clinically favorable effects of treprostinil in severe PAH may be attributable to concomitant activation of PGD2 receptor subtype 1 (DP1). OBJECTIVES: To study the role of DP1 in the progression of PAH and its underlying mechanism. METHODS AND RESULTS: DP1 expression was downregulated in hypoxia-treated PASMCs and in pulmonary arteries (PAs) from rodent PAH models and idiopathic PAH patients. DP1 deletion exacerbated PA remodeling in hypoxia-induced PAH, whereas pharmacological activation or forced expression of DP1 receptor had the opposite effect in different rodent models. DP1 deficiency promoted PASMC hypertrophy and proliferation in response to hypoxia via induction of mammalian target of rapamycin complex (mTORC) 1 activity. Rapamycin, an inhibitor of mTORC1, alleviated the hypoxia-induced exacerbation of PAH in DP1-/- mice. DP1 activation facilitated raptor dissociation from mTORC1 complex and suppressed mTORC1 activity through protein kinase A (PKA)-dependent phosphorylation of raptor at Ser791. Moreover, treprostinil treatment blocked the progression of hypoxia-induced PAH in mice in part by targeting DP1 receptor. CONCLUSION: DP1 activation attenuates hypoxia-induced PA remodeling and PAH through PKA-mediated dissociation of raptor from the mTORC1 complex. These results suggest that DP1 receptor may serve as a therapeutic target for the management of PAH.

4.
Proc Natl Acad Sci U S A ; 116(27): 13394-13403, 2019 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-31213542

RESUMO

Increased glycolysis in the lung vasculature has been connected to the development of pulmonary hypertension (PH). We therefore investigated whether glycolytic regulator 6-phosphofructo-2-kinase/fructose-2, 6-bisphosphatase (PFKFB3)-mediated endothelial glycolysis plays a critical role in the development of PH. Heterozygous global deficiency of Pfkfb3 protected mice from developing hypoxia-induced PH, and administration of the PFKFB3 inhibitor 3PO almost completely prevented PH in rats treated with Sugen 5416/hypoxia, indicating a causative role of PFKFB3 in the development of PH. Immunostaining of lung sections and Western blot with isolated lung endothelial cells showed a dramatic increase in PFKFB3 expression and activity in pulmonary endothelial cells of rodents and humans with PH. We generated mice that were constitutively or inducibly deficient in endothelial Pfkfb3 and found that these mice were incapable of developing PH or showed slowed PH progression. Compared with control mice, endothelial Pfkfb3-knockout mice exhibited less severity of vascular smooth muscle cell proliferation, endothelial inflammation, and leukocyte recruitment in the lungs. In the absence of PFKFB3, lung endothelial cells from rodents and humans with PH produced lower levels of growth factors (such as PDGFB and FGF2) and proinflammatory factors (such as CXCL12 and IL1ß). This is mechanistically linked to decreased levels of HIF2A in lung ECs following PFKFB3 knockdown. Taken together, these results suggest that targeting PFKFB3 is a promising strategy for the treatment of PH.

5.
Pharmacol Res ; 146: 104292, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31167111

RESUMO

Acute lung injury (ALI) is one of the leading causes of death in sepsis. Endothelial inflammation and dysfunction play a prominent role in development of ALI. Glycolysis is the predominant bioenergetic pathway for endothelial cells (ECs). However, the role of EC glycolysis in ALI of sepsis remains unclear. Here we show that both the expression and activity of PFKFB3, a key glycolytic activator, were markedly increased in lipopolysaccharide (LPS)-treated human pulmonary arterial ECs (HPAECs) in vitro and in lung ECs of mice challenged with LPS in vivo. PFKFB3 knockdown significantly reduced LPS-enhanced glycolysis in HPAECs. Compared with LPS-challenged wild-type mice, endothelial-specific Pfkfb3 knockout (Pfkfb3ΔVEC) mice exhibited reduced endothelium permeability, lower pulmonary edema, and higher survival rate. This was accompanied by decreased expression of intracellular adhesion molecule-1 (Icam-1) and vascular cell adhesion molecule 1 (Vcam-1), as well as decreased neutrophil and macrophage infiltration to the lung. Consistently, PFKFB3 silencing or PFKFB3 inhibition in HPAECs and human pulmonary microvascular ECs (HPMVECs) significantly downregulated LPS-induced expression of ICAM-1 and VCAM-1, and monocyte adhesion to human pulmonary ECs. In contrast, adenovirus-mediated PFKFB3 overexpression upregulated ICAM-1 and VCAM-1 expression in HPAECs. Mechanistically, PFKFB3 silencing suppressed LPS-induced nuclear translocation of nuclear factor κB (NF-κB)-p65, and NF-κB inhibitors abrogated PFKFB3-induced expression of ICAM-1 and VCAM-1. Finally, administration of the PFKFB3 inhibitor 3PO also reduced the inflammatory response of vascular endothelium and protected mice from LPS-induced ALI. Overall, these findings suggest that targeting PFKFB3-mediated EC glycolysis is an efficient therapeutic strategy for ALI in sepsis.

6.
Antioxid Redox Signal ; 31(12): 804-818, 2019 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-31088299

RESUMO

Aims: Airway and pulmonary vascular remodeling is an important pathological feature in the pathogenesis of chronic obstructive pulmonary disease (COPD). Tobacco smoke (TS) induces the production of large amounts of reactive oxygen species (ROS) in COPD lungs. We investigated how ROS lead to airway and pulmonary vascular remodeling in COPD. Results: We used in vitro bronchial and pulmonary artery smooth muscle cells (BSMCs and PASMCs), in vivo TS-induced COPD rodent models, and lung tissues of COPD patients. We found that H2O2 and TS extract (TSE) induced calpain activation in BSMCs and PASMCs. Calpain activation was elevated in smooth muscle of bronchi and pulmonary arterioles in COPD patients and TS-induced COPD rodent models. Calpain inhibition attenuated H2O2- and TSE-induced collagen synthesis and proliferation of BSMCs and PASMCs. Exposure to TS causes increases in airway resistance, right ventricular systolic pressure (RVSP), and thickening of bronchi and pulmonary arteries. Calpain inhibition by smooth muscle-specific knockout of calpain and the calpain inhibitor MDL28170 attenuated increases in airway resistance, RVSP, and thickening of bronchi and pulmonary arteries. Moreover, smooth muscle-specific knockout of calpain did not reduce TS-induced emphysema in the mouse model, but MDL28170 did reduce TS-induced emphysema in the rat model. Innovation: This study provides the first evidence that ROS-induced calpain activation contributes to airway and pulmonary vascular remodeling in TS-induced COPD. Calpain might be a novel therapeutic target for the treatment of COPD. Conclusion: These results indicate that ROS-induced calpain activation contributes to airway and pulmonary vascular remodeling and pulmonary hypertension in COPD.

7.
Am J Physiol Renal Physiol ; 317(1): F116-F123, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31091124

RESUMO

Stress granules (SGs) are a type of cytoplasmic structures formed in eukaryotic cells upon cell stress, which mainly contain RNA-binding proteins and RNAs. The formation of SGs is generally regarded as a mechanism for cells to survive a harsh insult. However, little is known about SG formation and function in kidneys. To address this, we applied different kinds of stressors to cultured proximal tubular cells as well as a short period of ischemia-reperfusion to mouse kidneys. It was found that glycolytic inhibitors such as 2-deoxy-d-glucose and 3-(3-pyridinyl)-1-(4-pyridinyl)-2-propen-1-one induced SG formation within 30 min in these cells. Similarly, SGs were induced by inhibitors of mitochondrial respiration such as sodium azide and CCCP. Renal ischemia-reperfusion induced SG formation in the cells of proximal tubules. To test the role of SGs, we stably knocked down G3bp1, a SG core protein, in renal tubular cells by shRNA viral transduction. As expected, knockdown of G3bp1 largely disrupted the assembly of SGs. After azide or cisplatin treatment, more dead cells were found in knockdown cells compared with controls, accompanied by increases in cleaved/active caspase-3. Reintroduction of exogenous G3bp1 into knockdown cells could rescue the cell death phenotype. Taken together, our data provide the first evidence of SG formation in renal tubular cells during metabolic stress and acute kidney injury. SGs are formed to protect proximal tubular cells under these conditions. Modulation of SG biogenesis may provide a novel approach to lessen the severity of renal diseases.

8.
Am J Respir Crit Care Med ; 200(5): 617-627, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-30817168

RESUMO

Rationale: Glycolytic shift is implicated in the pathogenesis of pulmonary arterial hypertension (PAH). It remains unknown how glycolysis is increased and how increased glycolysis contributes to pulmonary vascular remodeling in PAH.Objectives: To determine whether increased glycolysis is caused by 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3) and how PFKFB3-driven glycolysis induces vascular remodeling in PAH.Methods: PFKFB3 levels were measured in pulmonary arteries of patients and animals with PAH. Lactate levels were assessed in lungs of animals with PAH and in pulmonary artery smooth muscle cells (PASMCs). Genetic and pharmacologic approaches were used to investigate the role of PFKFB3 in PAH.Measurements and Main Results: Lactate production was elevated in lungs of PAH rodents and in platelet-derived growth factor-treated PASMCs. PFKFB3 protein was higher in pulmonary arteries of patients and rodents with PAH, in PASMCs of patients with PAH, and in platelet-derived growth factor-treated PASMCs. PFKFB3 inhibition by genetic disruption and chemical inhibitor attenuated phosphorylation/activation of extracellular signal-regulated kinase (ERK1/2) and calpain-2, and vascular remodeling in PAH rodent models, and reduced platelet-derived growth factor-induced phosphorylation/activation of ERK1/2 and calpain-2, collagen synthesis and proliferation of PASMCs. ERK1/2 inhibition attenuated phosphorylation/activation of calpain-2, and vascular remodeling in Sugen/hypoxia PAH rats, and reduced lactate-induced phosphorylation/activation of calpain-2, collagen synthesis, and proliferation of PASMCs. Calpain-2 inhibition reduced lactate-induced collagen synthesis and proliferation of PASMCs.Conclusions: Upregulated PFKFB3 mediates collagen synthesis and proliferation of PASMCs, contributing to vascular remodeling in PAH. The mechanism is through the elevation of glycolysis and lactate that results in the activation of calpain by ERK1/2-dependent phosphorylation of calpain-2.

9.
Am J Physiol Lung Cell Mol Physiol ; 316(5): L784-L797, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30724100

RESUMO

A defining characteristic of pulmonary hypertension (PH) is the extensive remodeling of pulmonary arteries (PAs), which results in progressive increases in vascular resistance and stiffness and eventual failure of the right ventricle. There is no cure for PH and identification of novel molecular mechanisms that underlie increased proliferation, reduced apoptosis, and excessive extracellular matrix production in pulmonary artery smooth muscle cells (PASMCs) is a vital objective. Galectin-3 (Gal-3) is a chimeric lectin and potent driver of many aspects of fibrosis, but its role in regulating PASMC behavior in PH remains poorly understood. Herein, we evaluated the importance of increased Gal-3 expression and signaling on PA vascular remodeling and cardiopulmonary function in experimental models of PH. Gal-3 expression was quantified by qRT-PCR, immunoblotting, and immunofluorescence imaging, and its functional role was assessed by specific Gal-3 inhibitors and CRISPR/Cas9-mediated knockout of Gal-3 in the rat. In rat models of PH, we observed increased Gal-3 expression in PASMCs, which stimulated migration and resistance to apoptosis, whereas silencing or genetic deletion reduced cellular migration and PA fibrosis and increased apoptosis. Gal-3 inhibitors attenuated and reversed PA remodeling and fibrosis, as well as hemodynamic indices in monocrotaline (MCT)-treated rats in vivo. These results were supported by genetic deletion of Gal-3 in both MCT and Sugen Hypoxia rat models. In conclusion, our results suggest that elevated Gal-3 levels contribute to inappropriate PA remodeling in PH by enhancing multiple profibrotic mechanisms. Therapeutic strategies targeting Gal-3 may be of benefit in the treatment of PH.


Assuntos
Apoptose , Proliferação de Células , Galectina 3/biossíntese , Regulação da Expressão Gênica , Hipertensão Pulmonar/metabolismo , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Fibrose Pulmonar/metabolismo , Animais , Modelos Animais de Doenças , Galectina 3/genética , Humanos , Hipertensão Pulmonar/genética , Hipertensão Pulmonar/patologia , Masculino , Músculo Liso Vascular/patologia , Miócitos de Músculo Liso/patologia , Fibrose Pulmonar/genética , Fibrose Pulmonar/patologia , Ratos , Ratos Sprague-Dawley
10.
Front Immunol ; 9: 1309, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29951058

RESUMO

Pneumonia is a leading cause of death in children and the elderly worldwide, accounting for 15% of all deaths of children under 5 years old. Streptococcus pneumoniae is a common and aggressive cause of pneumonia and can also contribute to meningitis and sepsis. Despite the widespread use of antibiotics, mortality rates for pneumonia remain unacceptably high in part due to the release of bacterial toxins. Pneumolysin (PLY) is a cholesterol-dependent toxin that is produced by Streptococcus, and it is both necessary and sufficient for the development of the extensive pulmonary permeability edema that underlies acute lung injury. The mechanisms by which PLY disrupts the pulmonary endothelial barrier are not fully understood. Previously, we found that reactive oxygen species (ROS) contribute to the barrier destructive effects of PLY and identified an unexpected but potent role of Hsp70 in suppressing ROS production. The ability of Hsp70 to influence PLY-induced barrier dysfunction is not yet described, and the goal of the current study was to identify whether Hsp70 upregulation is an effective strategy to protect the lung microvascular endothelial barrier from G+ bacterial toxins. Overexpression of Hsp70 via adenovirus-mediated gene transfer attenuated PLY-induced increases in permeability in human lung microvascular endothelial cells (HLMVEC) with no evidence of cytotoxicity. To adopt a more translational approach, we employed a pharmacological approach using geranylgeranylacetone (GGA) to acutely upregulate endogenous Hsp70 expression. Following acute treatment (6 h) with GGA, HLMVECs exposed to PLY displayed improved cell viability and enhanced endothelial barrier function as measured by both Electric Cell-substrate Impedance Sensing (ECIS) and transwell permeability assays compared to control treated cells. PLY promoted increased mitochondrial ROS, decreased mitochondrial oxygen consumption, and increased caspase 3 cleavage and cell death, which were collectively improved in cells pretreated with GGA. In mice, IP pretreatment with GGA 24 h prior to IT administration of PLY resulted in significantly less Evans Blue Dye extravasation compared to vehicle, indicating preserved endothelial barrier integrity and suggesting that the acute upregulation of Hsp70 may be an effective therapeutic approach in the treatment of lung injury associated with pneumonia.

11.
Cell Death Dis ; 9(3): 322, 2018 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-29476062

RESUMO

Histone deacetylase inhibitors (HDACi) have therapeutic effects in models of various renal diseases including acute kidney injury (AKI); however, the underlying mechanism remains unclear. Here we demonstrate that two widely tested HDACi (suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA)) protect the kidneys in cisplatin-induced AKI by enhancing autophagy. In cultured renal proximal tubular cells, SAHA and TSA enhanced autophagy during cisplatin treatment. We further verified the protective effect of TSA against cisplatin-induced apoptosis in these cells. Notably, inhibition of autophagy by chloroquine or by autophagy gene 7 (Atg7) ablation diminished the protective effect of TSA. In mice, TSA increased autophagy in renal proximal tubules and protected against cisplatin-induced AKI. The in vivo effect of TSA was also abolished by chloroquine and by Atg7 knockout specifically from renal proximal tubules. Mechanistically, TSA stimulated AMPK and inactivated mTOR during cisplatin treatment of proximal tubule cells and kidneys in mice. Together, these results suggest that HDACi may protect kidneys by activating autophagy in proximal tubular cells.


Assuntos
Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/prevenção & controle , Autofagia , Cisplatino/efeitos adversos , Inibidores de Histona Desacetilases/uso terapêutico , Túbulos Renais Proximais/patologia , Lesão Renal Aguda/patologia , Adenilato Quinase/metabolismo , Animais , Autofagia/efeitos dos fármacos , Proteína 7 Relacionada à Autofagia/metabolismo , Cloroquina/farmacologia , Citoproteção/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/uso terapêutico , Túbulos Renais Proximais/efeitos dos fármacos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Substâncias Protetoras/farmacologia , Substâncias Protetoras/uso terapêutico , Serina-Treonina Quinases TOR/metabolismo , Vorinostat/farmacologia , Vorinostat/uso terapêutico
12.
Sci Rep ; 8(1): 3114, 2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29449621

RESUMO

Because of the serious side effects of the currently used bronchodilators, new compounds with similar functions must be developed. We screened several herbs and found that Polygonum aviculare L. contains ingredients that inhibit the precontraction of mouse and human airway smooth muscle (ASM). High K+-induced precontraction in ASM was completely inhibited by nifedipine, a selective blocker of L-type voltage-dependent Ca2+ channels (LVDCCs). However, nifedipine only partially reduced the precontraction induced by acetylcholine chloride (ACH). Additionally, the ACH-induced precontraction was partly reduced by pyrazole-3 (Pyr3), a selective blocker of TRPC3 and stromal interaction molecule (STIM)/Orai channels. These channel-mediated currents were inhibited by the compounds present in P. aviculare extracts, suggesting that this inhibition was mediated by LVDCCs, TRPC3 and/or STIM/Orai channels. Moreover, these channel-mediated currents were inhibited by quercetin, which is present in P. aviculare extracts. Furthermore, quercetin inhibited ACH-induced precontraction in ASM. Overall, our data indicate that the ethyl acetate fraction of P. aviculare and quercetin can inhibit Ca2+-permeant LVDCCs, TRPC3 and STIM/Orai channels, which inhibits the precontraction of ASM. These findings suggest that P. aviculare could be used to develop new bronchodilators to treat obstructive lung diseases such as asthma and chronic obstructive pulmonary disease.


Assuntos
Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Extratos Vegetais/farmacologia , Polygonum/química , Quercetina/farmacologia , Acetilcolina/farmacologia , Animais , Cálcio/metabolismo , Canais de Cálcio Tipo L/metabolismo , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Músculo Liso/metabolismo , Nifedipino/farmacologia , Canais de Cátion TRPC/metabolismo
14.
J Gastrointest Surg ; 22(2): 366-367, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28785931

RESUMO

CASE PRESENTATION: A 33-year-old man had fever for 2 months. He was admitted by the physician with the suspicion of pneumonia. However, both chest X-ray and computed tomography (CT) showed no abnormality. Tuberculosis and hematological and autoimmune diseases were all excluded. A giant hepatic lesion (20 cm) was detected by ultrasonography with the diagnosis of hemangioma. Contrast enhanced CT scan was conducted and hepatic hemangioma was confirmed. Some areas of the hepatic lesion had lower density compared to surrounding tissues and necrosis of the tumor was suspected. TREATMENT: Right trisectionectomy was then performed and the symptom of fever disappeared after the operation. No bacteria grew in the culture of the necrosis tissue. Pathological examination confirmed the diagnosis of hemangioma and the necrosis. RESULTS: He was followed up for 5 months and no fever occurred.


Assuntos
Febre de Causa Desconhecida/etiologia , Hemangioma/complicações , Neoplasias Hepáticas/complicações , Fígado/patologia , Adulto , Hemangioma/cirurgia , Humanos , Neoplasias Hepáticas/cirurgia , Masculino , Necrose , Tomografia Computadorizada por Raios X , Ultrassonografia
15.
Pulm Pharmacol Ther ; 48: 46-52, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29107090

RESUMO

Pleural fibrosis is associated with various inflammatory processes such as tuberculous pleurisy and bacterial empyema. There is currently no ideal therapeutic to attenuate pleural fibrosis. Some pro-fibrogenic mediators induce fibrosis through inflammatory processes, suggesting that blockage of these mediators might prevent pleural fibrosis. The MeT-5A human pleural mesothelial cell line (PMC) was used in this study as an in vitro model of fibrosis; and intra-pleural injection of bleomycin with carbon particles was used as an in vivo mouse model of pleural fibrosis. Calpain knockout mice, calpain inhibitor (calpeptin), and angiotensin (Ang) II type 1 receptor (AT1R) antagonist (losartan) were evaluated in prevention of experimental pleural fibrosis. We found that bleomycin and carbon particles induced calpain activation in cultured PMCs. This in vitro response was associated with increased collagen-I synthesis, and was blocked by calpain inhibitor or AT1R antagonist. Calpain genetic or treatment with calpeptin or losartan prevented pleural fibrosis in a mouse model induced by bleomycin and carbon particles. Our findings indicate that Ang II signaling and calpain activation induce collagen-I synthesis and contribute to fibrotic alterations in pleural fibrosis. Inhibition of Ang II and calpain might therefore be a novel strategy in treatment of pleural fibrosis.


Assuntos
Calpaína/genética , Dipeptídeos/farmacologia , Losartan/farmacologia , Doenças Pleurais/tratamento farmacológico , Angiotensina II/efeitos dos fármacos , Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Animais , Bleomicina/toxicidade , Calpaína/antagonistas & inibidores , Carbono/toxicidade , Linhagem Celular , Colágeno Tipo I/metabolismo , Modelos Animais de Doenças , Fibrose , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Doenças Pleurais/fisiopatologia
16.
Adv Exp Med Biol ; 967: 139-160, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29047085

RESUMO

The calcium-dependent cytosolic, neutral, thiol endopeptidases, calpains, perform limited cleavage of their substrates thereby irreversibly changing their functions. Calpains have been shown to be involved in several physiological processes such as cell motility, proliferation, cell cycle, signal transduction, and apoptosis. Overactivation of calpain or mutations in the calpain genes contribute to a number of pathological conditions including neurodegenerative disorders, rheumatoid arthritis, cancer, and lung diseases. High concentrations of reactive oxygen and nitrogen species (RONS) originated from cigarette smoke or released by numerous cell types such as activated inflammatory cells and other respiratory cells cause oxidative and nitrosative stress contributing to the pathogenesis of COPD. RONS and calpain play important roles in the development of airway and pulmonary vascular remodeling in COPD. Published data show that increased RONS production is associated with increased calpain activation and/or elevated calpain protein level, leading to epithelial or endothelial barrier dysfunction, neovascularization, lung inflammation, increased smooth muscle cell proliferation, and deposition of extracellular matrix protein. Further investigation of the redox-dependent calpain signaling may provide future targets for the prevention and treatment of COPD.


Assuntos
Calpaína/metabolismo , Artéria Pulmonar/metabolismo , Doença Pulmonar Obstrutiva Crônica/metabolismo , Sistema Respiratório/metabolismo , Transdução de Sinais , Remodelação Vascular , Animais , Calpaína/genética , Humanos , Mutação , Oxirredução , Artéria Pulmonar/fisiopatologia , Doença Pulmonar Obstrutiva Crônica/genética , Doença Pulmonar Obstrutiva Crônica/fisiopatologia , Espécies Reativas de Nitrogênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sistema Respiratório/fisiopatologia
17.
Cell Rep ; 21(4): 1089-1101, 2017 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-29069590

RESUMO

G-protein-coupled receptors (GPCRs) constitute the largest superfamily of cell-surface signaling proteins. However, mechanisms underlying their surface targeting and sorting are poorly understood. Here, we screen the Rab family of small GTPases in the surface transport of multiple GPCRs. We find that manipulation of Rab43 function significantly alters the surface presentation and signaling of all GPCRs studied without affecting non-GPCR membrane proteins. Rab43 specifically regulates the transport of nascent GPCRs from the endoplasmic reticulum (ER) to the Golgi. More interestingly, Rab43 directly interacts with GPCRs in an activation-dependent fashion. The Rab43-binding domain identified in the receptors effectively converts non-GPCR membrane protein transport into a Rab43-dependent pathway. These data reveal a crucial role for Rab43 in anterograde ER-Golgi transport of nascent GPCRs, as well as the ER sorting of GPCR members by virtue of its ability to interact directly.


Assuntos
Retículo Endoplasmático/genética , Complexo de Golgi/metabolismo , Proteínas rab de Ligação ao GTP/metabolismo , Sítios de Ligação , Células HEK293 , Humanos , Células MCF-7 , Ligação Proteica , Transporte Proteico , Receptores Acoplados a Proteínas-G/química , Receptores Acoplados a Proteínas-G/metabolismo , Proteínas rab de Ligação ao GTP/química , Proteínas rab de Ligação ao GTP/genética
18.
Front Immunol ; 8: 842, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28785264

RESUMO

BACKGROUND: Streptococcus pneumoniae is a major etiologic agent of bacterial pneumonia. Autolysis and antibiotic-mediated lysis of pneumococci induce release of the pore-forming toxin, pneumolysin (PLY), their major virulence factor, which is a prominent cause of acute lung injury. PLY inhibits alveolar liquid clearance and severely compromises alveolar-capillary barrier function, leading to permeability edema associated with pneumonia. As a consequence, alveolar flooding occurs, which can precipitate lethal hypoxemia by impairing gas exchange. The α subunit of the epithelial sodium channel (ENaC) is crucial for promoting Na+ reabsorption across Na+-transporting epithelia. However, it is not known if human lung microvascular endothelial cells (HL-MVEC) also express ENaC-α and whether this subunit is involved in the regulation of their barrier function. METHODS: The presence of α, ß, and γ subunits of ENaC and protein phosphorylation status in HL-MVEC were assessed in western blotting. The role of ENaC-α in monolayer resistance of HL-MVEC was examined by depletion of this subunit by specific siRNA and by employing the TNF-derived TIP peptide, a specific activator that directly binds to ENaC-α. RESULTS: HL-MVEC express all three subunits of ENaC, as well as acid-sensing ion channel 1a (ASIC1a), which has the capacity to form hybrid non-selective cation channels with ENaC-α. Both TIP peptide, which specifically binds to ENaC-α, and the specific ASIC1a activator MitTx significantly strengthened barrier function in PLY-treated HL-MVEC. ENaC-α depletion significantly increased sensitivity to PLY-induced hyperpermeability and in addition, blunted the protective effect of both the TIP peptide and MitTx, indicating an important role for ENaC-α and for hybrid NSC channels in barrier function of HL-MVEC. TIP peptide blunted PLY-induced phosphorylation of both calmodulin-dependent kinase II (CaMKII) and of its substrate, the actin-binding protein filamin A (FLN-A), requiring the expression of both ENaC-α and ASIC1a. Since non-phosphorylated FLN-A promotes ENaC channel open probability and blunts stress fiber formation, modulation of this activity represents an attractive target for the protective actions of ENaC-α in both barrier function and liquid clearance. CONCLUSION: Our results in cultured endothelial cells demonstrate a previously unrecognized role for ENaC-α in strengthening capillary barrier function that may apply to the human lung. Strategies aiming to activate endothelial NSC channels that contain ENaC-α should be further investigated as a novel approach to improve barrier function in the capillary endothelium during pneumonia.

19.
Sci Rep ; 7: 44892, 2017 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-28317867

RESUMO

Interstitial fibrosis, a common pathological feature of chronic kidney diseases, is often associated with apoptosis in renal tissues. To determine the associated apoptotic pathway and its role in renal interstitial fibrosis, we established a mouse model in which Bax and Bak, two critical genes in the intrinsic pathway of apoptosis, were deleted specifically from kidney proximal tubules and used this model to examine renal apoptosis and interstitial fibrosis following unilateral urethral obstruction (UUO). It was shown that double knockout of Bax and Bak from proximal tubules attenuated renal tubular cell apoptosis and suppressed renal interstitial fibrosis in UUO. The results indicate that the intrinsic pathway of apoptosis contributes significantly to the tubular apoptosis and renal interstitial fibrosis in kidney diseases.


Assuntos
Apoptose/genética , Túbulos Renais Proximais/metabolismo , Obstrução Uretral/genética , Obstrução Uretral/patologia , Proteína Killer-Antagonista Homóloga a bcl-2/deficiência , Proteína X Associada a bcl-2/deficiência , Animais , Colágeno/metabolismo , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Fibrose , Camundongos , Camundongos Knockout
20.
J Allergy Clin Immunol ; 140(6): 1550-1561.e8, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28238747

RESUMO

BACKGROUND: C/EBP homologous protein (Chop), a marker of endoplasmic reticulum (ER) stress, exhibits aberrant expression patterns during asthma development. However, its exact role in asthma pathogenesis is not fully understood. OBJECTIVES: We aimed to determine the function and mechanism of Chop in the pathogenesis of allergic asthma in patients and animals. METHODS: Studies were conducted in asthmatic patients and Chop-/- mice to dissect the role of Chop and ER stress in asthma pathogenesis. An ovalbumin (OVA)-induced allergic airway inflammation model was used to address the effect of Chop deficiency on asthma development. Next, the effect of Chop deficiency on macrophage polarization and related signaling pathways was investigated to demonstrate the underlying mechanisms. RESULTS: Asthmatic patients and mice after OVA induction exhibited aberrant Chop expression along with ER stress. Specifically, Chop was noted to be specifically overexpressed in macrophages, and mice deficient in Chop were protected from OVA-induced allergic airway inflammation, as manifested by attenuated airway inflammation, remodeling, and hyperresponsiveness. Chop was found to exacerbate allergic airway inflammation by enhancing M2 programming in macrophages. Mechanistic studies characterized an IL-4/signal transducer and activator of transcription 6/transcription factor EC (Tfec)/IL-4 receptor α positive feedback regulatory loop, in which IL-4 induces Chop expression, which then promotes signal transducer and activator of transcription 6 signaling to transcribe Tfec expression. Finally, Tfec transcribes IL-4 receptor α expression to promote M2 programming in macrophages. CONCLUSIONS: Chop and ER stress are implicated in asthma pathogenesis, which involves regulation of M2 programming in macrophages.


Assuntos
Asma/imunologia , Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos/metabolismo , Estresse do Retículo Endoplasmático/imunologia , Macrófagos/imunologia , Fator de Transcrição CHOP/metabolismo , Adulto , Animais , Proteínas Estimuladoras de Ligação a CCAAT/metabolismo , Diferenciação Celular , Células Cultivadas , Progressão da Doença , Retroalimentação Fisiológica , Feminino , Humanos , Interleucina-4/metabolismo , Masculino , Camundongos , Camundongos Knockout , Pessoa de Meia-Idade , Receptores de Superfície Celular/metabolismo , Fator de Transcrição STAT6/metabolismo , Fator de Transcrição CHOP/genética
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