RESUMEN
BACKGROUND: It is established that the immune system, namely T cells, plays a role in the development of hypertension and renal damage in male Dahl salt-sensitive (SS) rats, but far less is known about this relationship in females. Rats with genetically deleted T cells via CD247 gene mutation on the Dahl SS background (SSCD247-/-) were utilized to interrogate the effect of sex and T cells on salt sensitivity. METHODS: We assessed the hypertensive and kidney injury phenotypes in male versus female SS and SSCD247-/- rats challenged with 3 weeks of high salt (4.0% NaCl). Differences in T cell activation genes were examined in renal T cells from male and female SS rats, and a sex-specific adoptive transfer was performed by injecting male or female splenocytes into either male or female SSCD247-/- recipients to determine the potential contribution of T cell sex. RESULTS: The lack of functional T cells in SSCD247-/- rats significantly reduced salt-induced hypertension and proteinuria in both sexes, although SSCD247-/- females exhibited greater protection from kidney damage. Adoptive transfer of either Dahl SS male or female splenocytes into SSCD247-/- male recipients exacerbated hypertension and proteinuria compared with controls, while in SSCD247-/- female recipients, exacerbation of disease occurred only upon transfer of male, but not female, SS splenocytes. CONCLUSIONS: The absence of T cells in the SSCD247-/- normalized sex differences in blood pressure, though sex differences in renal damage persisted. Splenocyte transfer experiments demonstrated that salt sensitivity is amplified if the sex of the T cell or the recipient is male.
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Hipertensión , Ratas Endogámicas Dahl , Linfocitos T , Animales , Masculino , Femenino , Ratas , Hipertensión/fisiopatología , Hipertensión/genética , Linfocitos T/inmunología , Factores Sexuales , Modelos Animales de Enfermedad , Cloruro de Sodio Dietético/efectos adversos , Presión Sanguínea/fisiología , Traslado Adoptivo , Riñón/patología , Riñón/metabolismoRESUMEN
BACKGROUND: AngII (angiotensin II)-dependent hypertension causes comparable elevations of blood pressure (BP), aldosterone levels, and renal ENaC (epithelial Na+ channel) activity in male and female rodents. Mineralocorticoid receptor (MR) antagonism has a limited antihypertensive effect associated with insufficient suppression of renal ENaC in male rodents with AngII-hypertension. While MR blockade effectively reduces BP in female mice with salt-sensitive and leptin-induced hypertension, MR antagonism has not been studied in female rodents with AngII-hypertension. We hypothesize that overstimulation of renal MR signaling drives redundant ENaC-mediated Na+ reabsorption and BP increase in female rats with AngII-hypertension. METHODS: We employ a combination of physiological, pharmacological, biochemical, and biophysical approaches to compare the effect of MR inhibitors on BP and ENaC activity in AngII-infused male and female Sprague Dawley rats. RESULTS: MR blockade markedly attenuates AngII-hypertension in female rats but has only a marginal effect in males. Spironolactone increases urinary sodium excretion and urinary sodium-to-potassium ratio in AngII-infused female, but not male, rats. The expression of renal MR and HSD11ß2 (11ß-hydroxysteroid dehydrogenase type 2) that determines the availability of MR to aldosterone is significantly higher in AngII-infused female rats than in males. ENaC activity is ≈2× lower in spironolactone-treated AngII-infused female rats than in males. Reduced ENaC activity in AngII-infused female rats on spironolactone correlates with increased interaction with ubiquitin ligase Nedd4-2 (neural precursor cell expressed developmentally down-regulated protein 4-2), targeting ENaC for degradation. CONCLUSIONS: MR-ENaC axis is the primary determinant of excessive renal sodium reabsorption and an attractive antihypertensive target in female rats with AngII-hypertension, but not in males.
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Hipertensión , Hipotensión , Femenino , Masculino , Ratas , Ratones , Animales , Antihipertensivos , Antagonistas de Receptores de Mineralocorticoides/farmacología , Aldosterona/farmacología , Espironolactona , Presión Sanguínea , Ratas Sprague-Dawley , Diuréticos , Hipertensión/inducido químicamente , Hipertensión/tratamiento farmacológico , SodioRESUMEN
Infiltrating T cells in the kidney amplify salt-sensitive (SS) hypertension and renal damage, but the mechanisms are not known. Genetic deletion of T cells (SSCD247-/-) or of the p67phox subunit of NADPH oxidase 2 (NOX2; SSp67phox-/-) attenuates SS hypertension in the Dahl SS rat. We hypothesized that reactive oxygen species produced by NOX2 in T cells drive the SS phenotype and renal damage. T cells were reconstituted by adoptively transferring splenocytes (â¼10 million) from the Dahl SS (SSâCD247) rat, the SSp67phox-/- rat (p67phoxâCD247), or only PBS (PBSâCD247) into the SSCD247-/- rat on postnatal day 5. Animals were instrumented with radiotelemeters and studied at 8 wk of age. There were no detectable differences in mean arterial pressure (MAP) or albuminuria between groups when rats were maintained on a low-salt (0.4% NaCl) diet. After 21 days of high-salt diet (4.0% NaCl), MAP and albuminuria were significantly greater in SSâCD247 rats compared with p67phoxâCD247 and PBSâCD247 rats. Interestingly, there was no difference between p67phoxâCD247 and PBSâCD247 rats in albuminuria or MAP after 21 days. The lack of CD3+ cells in PBSâCD247 rats and the presence of CD3+ cells in rats that received the T cell transfer demonstrated the effectiveness of the adoptive transfer. No differences in the number of CD3+, CD4+, or CD8+ cells were observed in the kidneys of SSâCD247 and p67phoxâCD247 rats. These results indicate that reactive oxygen species produced by NOX2 in T cells participates in the amplification of SS hypertension and renal damage.NEW & NOTEWORTHY Our current work used the adoptive transfer of T cells that lack functional NADPH oxidase 2 into a genetically T cell-deficient Dahl salt-sensitive (SS) rat model. The results demonstrated that reactive oxygen species produced by NADPH oxidase 2 in T cells participate in the amplification of SS hypertension and associated renal damage and identifies a potential mechanism that exacerbates the salt-sensitive phenotype.
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Hipertensión , Cloruro de Sodio , Ratas , Animales , Albuminuria , NADPH Oxidasa 2/genética , Especies Reactivas de Oxígeno , Linfocitos T , Ratas Endogámicas Dahl , Riñón , Hipertensión/genética , Cloruro de Sodio Dietético , NADPH Oxidasas/genéticaRESUMEN
BACKGROUND: TSP1 (thrombospondin-1)-a well-known angiogenesis inhibitor-mediates differential effects via interacting with cell surface receptors including CD36 (cluster of differentiation) and CD47. However, the role of TSP1 in regulating lymphangiogenesis is not clear. Our previous study suggested the importance of cell-specific CD47 blockade in limiting atherosclerosis. Further, our experiments revealed CD47 as a dominant TSP1 receptor in lymphatic endothelial cells (LECs). As the lymphatic vasculature is functionally linked to atherosclerosis, we aimed to investigate the effects of LEC TSP1-CD47 signaling inhibition on lymphangiogenesis and atherosclerosis. METHODS: Murine atherosclerotic and nonatherosclerotic arteries were utilized to investigate TSP1 expression using Western blotting and immunostaining. LEC-specific knockout mice were used to determine the in vivo role of LEC Cd47 in lymphangiogenesis and atherosclerosis. Various in vitro cell-based assays, in vivo Matrigel plug implantation, molecular biological techniques, and immunohistological approaches were used to evaluate the underlying signaling mechanisms. RESULTS: Elevated TSP1 expression was observed in mouse atherosclerotic aortic tissue compared with nonatherosclerotic control tissue. TSP1 at pathological concentrations suppressed both in vitro and in vivo lymphangiogenesis. Mechanistically, TSP1 inhibited VEGF (vascular endothelial growth factor)-C-induced AKT and eNOS activation in LEC and attenuated NO (nitric oxide) production. Further, CD47 silencing in LEC prevented the effects of TSP1 on lymphangiogenic AKT-eNOS signaling and lymphangiogenesis. Atheroprone AAV (adeno-associated virus) 8-PCSK9-injected LEC-specific Cd47 knockout mice (Cd47ΔLEC) had reduced atherosclerosis in both aorta and aortic root compared with control mice (Cd47ΔWT). However, no differences in metabolic parameters including body weight, plasma total cholesterol levels, and fasting blood glucose were observed. Additional immunostaining experiments performed on aortic root cross-sections indicated higher lymphatic vessel density in Cd47ΔLEC mice in comparison to controls. CONCLUSIONS: These findings demonstrate that TSP1 inhibits lymphangiogenesis via activation of CD47 in LEC, and loss of LEC Cd47 attenuates atherosclerotic lesion formation. Collectively, these results identify LEC CD47 as a potential therapeutic target in atherosclerosis.
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Aterosclerosis , Células Endoteliales , Animales , Ratones , Aterosclerosis/genética , Aterosclerosis/prevención & control , Aterosclerosis/metabolismo , Antígeno CD47/genética , Antígeno CD47/metabolismo , Células Endoteliales/metabolismo , Linfangiogénesis , Ratones Noqueados , Proproteína Convertasa 9/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Trombospondina 1/genética , Trombospondina 1/metabolismo , Factor A de Crecimiento Endotelial Vascular/metabolismoRESUMEN
Accumulation of lipid-laden foam cells in the arterial wall plays a central role in atherosclerotic lesion development, plaque progression, and late-stage complications of atherosclerosis. However, there are still fundamental gaps in our knowledge of the underlying mechanisms leading to foam cell formation in atherosclerotic arteries. Here, we investigated the role of receptor-independent macropinocytosis in arterial lipid accumulation and pathogenesis of atherosclerosis. Genetic inhibition of fluid-phase macropinocytosis in myeloid cells (LysMCre+ Nhe1fl/fl) and repurposing of a Food and Drug Administration (FDA)-approved drug that inhibits macrophage macropinocytosis substantially decreased atherosclerotic lesion development in low-density lipoprotein (LDL) receptor-deficient and Apoe-/- mice. Stimulation of macropinocytosis using genetic (H-RASG12V) and physiologically relevant approaches promoted internalization of unmodified native (nLDL) and modified [e.g., acetylated (ac) and oxidized (ox) LDL] lipoproteins in both wild-type and scavenger receptor (SR) knockout (Cd36-/-/Sra-/-) macrophages. Pharmacological inhibition of macropinocytosis in hypercholesterolemic wild-type and Cd36-/-/Sra-/- mice identified an important role of macropinocytosis in LDL uptake by lesional macrophages and development of atherosclerosis. Furthermore, serial section high-resolution imaging, LDL immunolabeling, and three-dimensional (3D) reconstruction of subendothelial foam cells provide visual evidence of lipid macropinocytosis in both human and murine atherosclerotic arteries. Our findings complement the SR paradigm of atherosclerosis and identify a therapeutic strategy to counter the development of atherosclerosis and cardiovascular disease.
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Aterosclerosis , Células Espumosas , Animales , Apolipoproteínas E/genética , Arterias/patología , Aterosclerosis/patología , Antígenos CD36 , Células Espumosas/metabolismo , Células Espumosas/patología , Humanos , Lipoproteínas LDL/metabolismo , Ratones , Ratones NoqueadosRESUMEN
Salt-sensitive hypertension, increases in blood pressure in response to increased salt intake, is associated with an increased risk of morbidity, mortality, and end-organ damage compared with salt-resistant hypertension. The Dahl salt-sensitive (SS) rat mimics the phenotypic characteristics observed in human hypertension when rats are challenged with a high-salt diet. Our previous work demonstrated that environmental factors, such as dietary protein, alter the severity of salt sensitivity in Dahl SS rats and should be an important consideration in experimental design. The present study investigated how the bedding on which animals were maintained (wood vs. corncob) could impact the SS phenotype in the Dahl SS rat. Animals that were maintained on corncob bedding exhibited a significant attenuation in blood pressure and renal end-organ damage in response to a high-salt diet compared with animals maintained on wood bedding. This attenuation was associated with an improvement in renal function and reduction in immune cell infiltration into the kidneys of Dahl SS rats maintained on corncob bedding. These results indicate that the type of bedding impacts the SS phenotype in the Dahl SS rat and that the bedding used in experiments can be a confounding factor to consider during data interpretation and experimental design.NEW & NOTEWORTHY Results from our present study demonstrate the profound effect of animal bedding on the severity of salt-sensitive hypertension, renal damage, and inflammation in Dahl salt-sensitive rats. This study highlights the important consideration that should be given to environmental factors, namely, the type of bedding in animal facilities, in experimental design and data interpretation.
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Hipertensión , Cloruro de Sodio Dietético , Humanos , Ratas , Animales , Cloruro de Sodio Dietético/metabolismo , Ratas Endogámicas Dahl , Riñón/metabolismo , Presión Sanguínea , Ropa de Cama y Ropa Blanca/efectos adversosRESUMEN
AIMS: Inhibitors of the anti-phagocytic CD47-SIRPα immune checkpoint are currently in clinical development for a variety of haematological and solid tumours. Application of immune checkpoint inhibitors to the cardiovascular field is limited by the lack of preclinical studies using genetic models of CD47 and SIRPα inhibition. In this study, we comprehensively analysed the effects of global and cell-specific SIRPα and CD47 deletion on atherosclerosis development. METHODS AND RESULTS: Here, we show that both SIRPα and CD47 expression are increased in human atherosclerotic arteries and primarily co-localize to CD68+ areas in the plaque region. Hypercholesterolaemic mice homozygous for a Sirpa mutant lacking the signalling cytoplasmic region (Sirpamut/mut) and myeloid cell-specific Sirpa-knockout mice are protected from atherosclerosis. Further, global Cd47-/- mice are protected from atherosclerosis but myeloid cell-specific deletion of Cd47 increased atherosclerosis development. Using a combination of techniques, we show that loss of SIRPα signalling in macrophages stimulates efferocytosis, reduces cholesterol accumulation, promotes lipid efflux, and attenuates oxidized LDL-induced inflammation in vitro and induces M2 macrophage phenotype and inhibits necrotic core formation in the arterial wall in vivo. Conversely, loss of myeloid cell CD47 inhibited efferocytosis, impaired cholesterol efflux, augmented cellular inflammation, stimulated M1 polarization, and failed to decrease necrotic core area in atherosclerotic vessels. Finally, comprehensive blood cell analysis demonstrated lower haemoglobin and erythrocyte levels in Cd47-/- mice compared with wild-type and Sirpamut/mut mice. CONCLUSION: Taken together, these findings identify SIRPα as a potential target in atherosclerosis and suggest the importance of cell-specific CD47 inhibition as a future therapeutic strategy.
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Aterosclerosis , Células Mieloides , Animales , Humanos , Ratones , InflamaciónRESUMEN
Terbinafine is a commonly used antifungal medication. Its side effects, while widely known, are rarely described and can be missed by the medical community. We present a 55-year-old woman who visited her primary care physician with onychomycosis. She started treatment with terbinafine, and 1 week later developed a rash in the left flank that extended to the chest, back, and upper part of lower extremities. Laboratory results showed elevated liver enzymes. A treatment with steroids did not improve the rash and she was admitted to our institution. She was started with intravenous dexamethasone, topical hydrocortisone and triamcinolone. Seven days later the liver enzymes normalised, and the rash resolved on the chest and back. Our patient had concurrent acute generalised exanthematous pustulosis and hepatitis that together has been very rarely associated with terbinafine.
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Pustulosis Exantematosa Generalizada Aguda/diagnóstico , Pustulosis Exantematosa Generalizada Aguda/etiología , Antifúngicos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico , Enfermedad Hepática Inducida por Sustancias y Drogas/etiología , Terbinafina/efectos adversos , Pustulosis Exantematosa Generalizada Aguda/terapia , Enfermedad Hepática Inducida por Sustancias y Drogas/terapia , Femenino , Humanos , Persona de Mediana Edad , Onicomicosis/tratamiento farmacológicoRESUMEN
Acute lung injury (ALI) is an acute inflammatory process arises from a wide range of lung insults. A major cause of ALI is dysfunction of the pulmonary vascular endothelial barrier but the mechanisms involved are incompletely understood. The therapeutic potential of histone deacetylase (HDAC) inhibitors for the treatment of cardiovascular and inflammatory diseases is increasingly apparent, but the mechanisms by which HDACs regulate pulmonary vascular barrier function remain to be resolved. We found that specific Class IIa HDACs inhibitor, TMP269, significantly attenuated the lipopolysaccharide (LPS)-induced human lung microvascular endothelial cells (HLMVEC) barrier compromise in vitro and improved vascular barrier integrity and lung function in murine model of ALI in vivo. TMP269 decreased LPS-induced myosin light chain phosphorylation suggesting the role for Class IIa HDACs in LPS-induced cytoskeleton reorganization. TMP269 did not affect microtubule structure and tubulin acetylation in contrast to the HDAC6-specific inhibitor, Tubastatin A suggesting that Class IIa HDACs and HDAC6 (Class IIb) regulate endothelial cytoskeleton and permeability via different mechanisms. Furthermore, LPS increased the expression of ArgBP2 which has recently been attributed to HDAC-mediated activation of Rho. Depletion of ArgBP2 abolished the ability of LPS to disrupt barrier function in HLMVEC and both TMP269 and Tubastatin A decreased the level of ArgBP2 expression after LPS stimulation suggesting that both Class IIa and IIb HDACs regulate endothelial permeability via ArgBP2-dependent mechanism. Collectively, our data strongly suggest that Class IIa HDACs are involved in LPS-induced ALI in vitro and in vivo via specific mechanism which involved contractile responses, but not microtubule reorganization.
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Lesión Pulmonar Aguda/inducido químicamente , Lesión Pulmonar Aguda/enzimología , Histona Desacetilasas/metabolismo , Lesión Pulmonar Aguda/fisiopatología , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Animales , Permeabilidad de la Membrana Celular/efectos de los fármacos , Modelos Animales de Enfermedad , Células Endoteliales/efectos de los fármacos , Células Endoteliales/metabolismo , Endotoxinas , Frecuencia Cardíaca/efectos de los fármacos , Inhibidores de Histona Desacetilasas/farmacología , Lipopolisacáridos , Pulmón/efectos de los fármacos , Pulmón/patología , Pulmón/fisiopatología , Ratones Endogámicos C57BL , Microvasos/patología , Modelos Biológicos , Oxígeno/metabolismo , Neumonía/complicaciones , Neumonía/patología , Transducción de Señal/efectos de los fármacos , Proteínas de Unión al GTP rho/metabolismoRESUMEN
AIMS: Impaired lymphatic drainage of the arterial wall results in intimal lipid accumulation and atherosclerosis. However, the mechanisms regulating lymphangiogenesis in atherosclerotic arteries are not well understood. Our studies identified elevated levels of matrix protein R-spondin 2 (RSPO2) in atherosclerotic arteries. In this study, we investigated the role of RSPO2 in lymphangiogenesis, arterial cholesterol efflux into lesion-draining lymph nodes (LNs) and development of atherosclerosis. METHODS AND RESULTS: The effect of RSPO2 on lymphangiogenesis was investigated using human lymphatic endothelial cells (LEC) in vitro and implanted Matrigel plugs in vivo. Cellular and molecular approaches, pharmacological agents, and siRNA silencing of RSPO2 receptor LGR4 were used to investigate RSPO2-mediated signalling in LEC. In vivo low-density lipoprotein (LDL) tracking and perivascular blockade of RSPO2-LGR4 signalling using LGR4-extracellular domain (ECD) pluronic gel in hypercholesterolemic mice were utilized to investigate the role of RSPO2 in arterial reverse cholesterol transport and atherosclerosis. Immunoblotting and imaging experiments demonstrated increased RSPO2 expression in human and mouse atherosclerotic arteries compared to non-atherosclerotic controls. RSPO2 treatment inhibited lymphangiogenesis both in vitro and in vivo. LGR4 silencing and inhibition of RSPO2-LGR4 signalling abrogated RSPO2-induced inhibition of lymphangiogenesis. Mechanistically, we found that RSPO2 suppresses PI3K-AKT-endothelial nitric oxide synthase (eNOS) signalling via LGR4 and inhibits activation of the canonical Wnt-ß-catenin pathway. ApoE-/- mice treated with LGR4-ECD developed significantly less atherosclerosis compared with control treatment. Finally, increased arterial lymphatic vessel density and improved lymphatic drainage of fluorescently labelled LDL to deep cervical LNs were observed in LGR4-ECD-treated mice. CONCLUSION: These findings demonstrate that RSPO2 inhibits lymphangiogenesis via LGR4 and downstream impairment of AKT-eNOS-nitric oxide signalling. These results may also inform new therapeutic strategies to promote lymphangiogenesis and improve cholesterol efflux from atherosclerotic arteries.
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Arterias/metabolismo , Aterosclerosis/metabolismo , Péptidos y Proteínas de Señalización Intercelular/metabolismo , Linfangiogénesis , Vasos Linfáticos/metabolismo , Trombospondinas/metabolismo , Anciano , Anciano de 80 o más Años , Animales , Arterias/patología , Aterosclerosis/genética , Aterosclerosis/patología , Células Cultivadas , Modelos Animales de Enfermedad , Células Endoteliales/metabolismo , Células Endoteliales/patología , Femenino , Humanos , Péptidos y Proteínas de Señalización Intercelular/genética , Vasos Linfáticos/patología , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Persona de Mediana Edad , Óxido Nítrico Sintasa de Tipo III/genética , Óxido Nítrico Sintasa de Tipo III/metabolismo , Placa Aterosclerótica , Proteínas Proto-Oncogénicas c-akt/metabolismo , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transducción de Señal , Trombospondinas/genéticaRESUMEN
Genomic sequence and gene expression association studies in animals and humans have identified genes that may be integral in the pathogenesis of various diseases. CD14 (cluster of differentiation 14)-a cell surface protein involved in innate immune system activation-is one such gene associated with cardiovascular and hypertensive disease. We previously showed that this gene is upregulated in renal macrophages of Dahl salt-sensitive animals fed a high-salt diet; here we test the hypothesis that CD14 contributes to the elevated pressure and renal injury observed in salt-sensitive hypertension. Using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats/clustered regularly interspaced short palindromic repeat-associated 9), we created a targeted mutation in the CD14 gene on the Dahl SS (SS/JrHSDMcwi) background and validated the absence of CD14 peptides via mass spectrometry. Radiotelemetry was used to monitor blood pressure in wild-type and CD14-/- animals challenged with high salt and identified infiltrating renal immune cells via flow cytometry. Germline knockout of CD14 exacerbated salt-sensitive hypertension and renal injury in female animals but not males. CD14-/- females demonstrated increased infiltrating macrophages but no difference in infiltrating lymphocytes. Transplant of CD14+/+ or CD14-/- bone marrow was used to isolate the effects of CD14 knockout to hematopoietic cells and confirmed that the differential phenotype observed was due to knockout of CD14 in hematopoietic cells. Ovariectomy was used to remove the influence of female sex hormones, which completely abrogated the effect of CD14 knockout. These studies provide a novel treatment target and evidence of a new dichotomy in immune activation between sexes within the context of hypertensive disease where CD14 regulates immune cell activation and renal injury.
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Hipertensión/inmunología , Riñón/patología , Receptores de Lipopolisacáridos/fisiología , Caracteres Sexuales , Lesión Renal Aguda , Animales , Estradiol/fisiología , Femenino , Hipertensión/complicaciones , Receptores de Lipopolisacáridos/genética , Masculino , Ratas , Ratas Endogámicas DahlRESUMEN
Squamous cell carcinoma (SCC) of the lip typically has a good prognosis when diagnosed at an early stage and treated properly. We present a 65-year-old man with a 3-month history of an ulcerative lesion of the lower lip. On physical examination, he had an ulceration of approximately 5×5 cm in the mucosa of the lower lip, extending through 50% of the lip, and multiple mandibular and neck lymph nodes. The biopsy confirmed SCC of the lip. Surgical treatment was recommended, but the patient was lost to follow-up. The patient eventually returned to the hospital for medical treatment. However, the physical examination, and the images obtained showed progression of the disease. Chemotherapy was started with improvement in the primary site, but he then developed a large submental mass compatible with SCC. The tumour was considered incurable at that time. Palliative radiation therapy was offered; however, he refused any further procedures or treatment.
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Neoplasias de los Labios/diagnóstico , Labio/patología , Metástasis Linfática/diagnóstico , Carcinoma de Células Escamosas de Cabeza y Cuello/diagnóstico , Anciano , Biopsia , Humanos , Neoplasias de los Labios/patología , Neoplasias de los Labios/terapia , Metástasis Linfática/terapia , Masculino , Cuidados Paliativos , Carcinoma de Células Escamosas de Cabeza y Cuello/secundario , Carcinoma de Células Escamosas de Cabeza y Cuello/terapiaRESUMEN
Lipopolysaccharide (LPS), a component of the outer membrane of gram-negative bacteria, disrupts the alveolar-capillary barrier, triggering pulmonary vascular leak thus inducing acute lung injury (ALI). Extracellular purines, adenosine and ATP, protected against ALI induced by purified LPS. In this study, we investigated whether these purines can impact vascular injury in more clinically-relevant E.coli (non-sterile LPS) murine ALI model. Mice were inoculated with live E. coli intratracheally (i.t.) with or without adenosine or a non-hydrolyzable ATP analog, adenosine 5'-(γ-thio)-triphosphate (ATPγS) added intravenously (i.v.). After 24 h of E. coli treatment, we found that injections of either adenosine or ATPγS 15 min prior or adenosine 3 h after E.coli insult significantly attenuated the E.coli-mediated increase in inflammatory responses. Furthermore, adenosine prevented weight loss, tachycardia, and compromised lung function in E. coli-exposed mice. Accordingly, treatment with adenosine or ATPγS increased oxygen saturation and reduced histopathological signs of lung injury in mice exposed to E. coli. Lastly, lung-targeting gene delivery of adenosine or ATPγS downstream effector, myosin phosphatase, significantly attenuated the E. coli-induced compromise of lung function. Collectively, our study has demonstrated that adenosine or ATPγS mitigates E. coli-induced ALI in mice and may be useful as an adjuvant therapy in future pre-clinical studies.
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Lesión Pulmonar Aguda/prevención & control , Adenosina Trifosfato/análogos & derivados , Adenosina/farmacología , Escherichia coli/patogenicidad , Neumonía Bacteriana/complicaciones , Vasodilatadores/farmacología , Lesión Pulmonar Aguda/etiología , Adenosina Trifosfato/farmacología , Marcadores de Afinidad/farmacología , Animales , Masculino , Ratones , Ratones Endogámicos C57BLRESUMEN
The vasa vasorum (VV), the microvascular network around large vessels, has been recognized as an important contributor to the pathological vascular remodeling in cardiovascular diseases. In bovine and rat models of hypoxic pulmonary hypertension (PH), we have previously shown that chronic hypoxia profoundly increased pulmonary artery (PA) VV permeability, associated with infiltration of inflammatory and progenitor cells in the arterial wall, perivascular inflammation, and structural vascular remodeling. Extracellular adenosine was shown to exhibit a barrier-protective effect on VV endothelial cells (VVEC) via cAMP-independent mechanisms, which involved adenosine A1 receptor-mediated activation of Gi-phosphoinositide 3-kinase-Akt pathway and actin cytoskeleton remodeling. Using VVEC isolated from the adventitia of calf PA, in this study we investigated in more detail the mechanisms linking Gi activation to downstream barrier protection pathways. Using a small-interference RNA (siRNA) technique and transendothelial electrical resistance assay, we found that the adaptor protein, engulfment and cell motility 1 (ELMO1), the tyrosine phosphatase Src homology region 2 domain-containing phosphatase-2, and atypical Gi- and Rac1-mediated protein kinase A activation are implicated in VVEC barrier enhancement. In contrast, the actin-interacting GTP-binding protein, girdin, and the p21-activated kinase 1 downstream target, LIM kinase, are not involved in this response. In addition, adenosine-dependent cytoskeletal rearrangement involves activation of cofilin and inactivation of ezrin-radixin-moesin regulatory cytoskeletal proteins, consistent with a barrier-protective mechanism. Collectively, our data indicate that targeting adenosine receptors and downstream barrier-protective pathways in VVEC may have a potential translational significance in developing pharmacological approach for the VV barrier protection in PH.
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Proteínas Adaptadoras Transductoras de Señales/metabolismo , Adenosina/metabolismo , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Células Endoteliales/metabolismo , Subunidades alfa de la Proteína de Unión al GTP Gi-Go/metabolismo , Vasa Vasorum/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Adenosina/farmacología , Animales , Bovinos , Células Endoteliales/efectos de los fármacos , Líquido Extracelular/efectos de los fármacos , Líquido Extracelular/metabolismo , Masculino , Arteria Pulmonar/efectos de los fármacos , Arteria Pulmonar/metabolismo , Transducción de Señal/efectos de los fármacos , Transducción de Señal/fisiología , Vasa Vasorum/efectos de los fármacosRESUMEN
The Cre/loxP recombination system has revolutionized the ability to genetically manipulate animal genomes in order to conditionally control gene expression. With recent advances in genome editing, barriers to manipulating the rat genome have been overcome and it is now possible to generate new rat strains (Cre drivers) in which Cre recombinase expression is carefully controlled temporally and/or spatially. However, the ability to evaluate and characterize these Cre driver strains is limited by the availability of reliable reporter rat strains. Here, we describe the generation and characterization of a new transgenic rat strain in which conditional expression of the ZsGreen fluorescent protein gene requires the presence of exogenous Cre recombinase. Breeding Cre-expressing rat strains to this stable ZsGreen reporter strain provides an ideal method for validating new rat Cre driver lines and will greatly accelerate the characterization pipeline.
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Genes Reporteros/genética , Ingeniería Genética/métodos , Integrasas/genética , Proteínas Luminiscentes/genética , Animales , Femenino , Expresión Génica , Regulación de la Expresión Génica/genética , Genoma/genética , Integrasas/biosíntesis , Masculino , Ratas , Ratas Endogámicas F344 , Ratas Transgénicas , Recombinación Genética/genéticaRESUMEN
Neurofibromin, the protein product of the neurofibromatosis type 1 (NF1) tumor suppressor gene, is a negative regulator of Ras signaling. Patients with mutations in NF1 have a strong predisposition for cardiovascular disease, which contributes to their early mortality. Nf1 heterozygous (Nf1+/-) bone marrow to wild type chimeras and mice with heterozygous recombination of Nf1 in myeloid cells recapitulate many of the vascular phenotypes observed in Nf1+/- mutants. Although these results suggest that macrophages play a central role in NF1 vasculopathy, the underlying mechanisms are currently unknown. In the present study, we employed macrophages isolated from either Nf1+/- or Lysm Cre+/Nf1f/f mice to test the hypothesis that loss of Nf1 stimulates macropinocytosis in macrophages. Scanning electron microscopy and flow cytometry analysis of FITC-dextran internalization demonstrated that loss of Nf1 in macrophages stimulates macropinocytosis. We next utilized various cellular and molecular approaches, pharmacological inhibitors and genetically modified mice to identify the signaling mechanisms mediating macropinocytosis in Nf1-deficient macrophages. Our results indicate that loss of Nf1 stimulates PKCδ-mediated p47phox phosphorylation via RAS activation, leading to increased NADPH oxidase 2 activity, reactive oxygen species generation, membrane ruffling and macropinocytosis. Interestingly, we also found that Nf1-deficient macrophages internalize exosomes derived from angiotensin II-treated endothelial cells via macropinocytosis in vitro and in the peritoneal cavity in vivo. As a result of exosome internalization, Nf1-deficient macrophages polarized toward an inflammatory M1 phenotype and secreted increased levels of proinflammatory cytokines compared to controls. In conclusion, the findings of the present study demonstrate that loss of Nf1 stimulates paracrine endothelial to myeloid cell communication via macropinocytosis, leading to proinflammatory changes in recipient macrophages.
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Comunicación Celular/fisiología , Proteínas Activadoras de GTPasa/metabolismo , Neurofibromatosis 1/metabolismo , Comunicación Paracrina/fisiología , Pinocitosis/fisiología , Animales , Línea Celular , Células Endoteliales/metabolismo , Exosomas/metabolismo , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Células Mieloides/metabolismo , NADPH Oxidasa 2/metabolismo , Fosforilación/fisiología , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal/fisiologíaRESUMEN
Many organisms live in complex environments that vary geographically in resource availability. This environmental heterogeneity can lead to changes within species in their phenotypic traits. For example, in many herbivorous insects, variation in host plant availability has been shown to influence insect host preference behavior. This behavior can be mediated in part through the insect olfactory system and the odor-evoked responses of olfactory sensory neurons (OSNs), which are in turn mediated by their corresponding odorant receptor genes. The desert dwelling fly Drosophila mojavensis is a model species for understanding the mechanisms underlying host preference in a heterogeneous environment. Depending on geographic region, one to multiple host plant species are available. Here, we conducted electrophysiological studies and found variation in responses of ORNs to host plant volatiles both within and between 2 populations-particularly to the odorant 4-methylphenol. Flies from select localities within each population were found to lack a response to 4-methylphenol. Experiments then assessed the extent to which these electrophysiological differences were associated with differences in several odor-mediated behavioral responses. No association between the presence/absence of these odor-evoked responses and short range olfactory behavior or oviposition behavior was observed. However, differences in odor-induced feeding behavior in response to 4-methylphenol were found. Localities that exhibit an odor-evoked response to the odorant had increased feeding behavior in the presence of the odorant. This study sets the stage for future work examining the functional genetics underlying variation in odor perception.
Asunto(s)
Drosophila/fisiología , Preferencias Alimentarias , Olfato , Animales , Cactaceae/parasitología , Cresoles/metabolismo , Ecosistema , Femenino , Neuronas Receptoras Olfatorias/fisiologíaRESUMEN
Macropinocytosis is an actin-dependent endocytic mechanism mediating internalization of extracellular fluid and associated solutes into cells. The present study was designed to identify the specific protein kinase C (PKC) isoform(s) and downstream effectors regulating actin dynamics during macropinocytosis. We utilized various cellular and molecular biology techniques, pharmacological inhibitors and genetically modified mice to study the signaling mechanisms mediating macropinocytosis in macrophages. The qRT-PCR experiments identified PKCδ as the predominant PKC isoform in macrophages. Scanning electron microscopy and flow cytometry analysis of FITC-dextran internalization demonstrated the functional role of PKCδ in phorbol ester- and hepatocyte growth factor (HGF)-induced macropinocytosis. Western blot analysis demonstrated that phorbol ester and HGF stimulate activation of slingshot phosphatase homolog 1 (SSH1) and induce cofilin Ser-3 dephosphorylation via PKCδ in macrophages. Silencing of SSH1 inhibited cofilin dephosphorylation and macropinocytosis stimulation. Interestingly, we also found that incubation of macrophages with BMS-5, a potent inhibitor of LIM kinase, does not stimulate macropinocytosis. In conclusion, the findings of the present study demonstrate a previously unidentified mechanism by which PKCδ via activation of SSH1 and cofilin dephosphorylation stimulates membrane ruffle formation and macropinocytosis. The results of the present study may contribute to a better understanding of the regulatory mechanisms during macrophage macropinocytosis.