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BACKGROUND: Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance has emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen crosslinking enzyme lysyl oxidase like 2 (LOXL2) in this study. METHODS AND RESULTS: Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from pulmonary arteries of the rat Sugen5416 + hypoxia (SuHx) model of severe PH. Similarly, LOXL2 protein and mRNA levels were increased in pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in-vivo with PAT-1251. Importantly PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. CONCLUSION: Hypoxia induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH, as well as pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 could be a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH.
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Hypertension, a disease with known sexual dimorphism, accelerates aging-associated arterial stiffening, partly because of the activation of matrix remodeling caused by increased biomechanical load. In this study, we tested the effect of biological sex and the role of the matrix remodeling enzyme lysyl oxidase-like 2 (LOXL2) in hypertension-induced arterial stiffening. Hypertension was induced by angiotensin II (ANG II) infusion via osmotic minipumps in 12- to 14-wk-old male and female mice. Blood pressure and pulse wave velocity (PWV) were measured noninvasively. Wire myography and uniaxial tensile testing were used to test aortic vasoreactivity and mechanical properties. Aortic wall composition was examined by histology and Western blotting. Uniaxial stretch of cultured cells was used to evaluate the effect of biomechanical strain. LOXL2's catalytic function was examined using knockout and inhibition. ANG II infusion-induced hypertension in both genotypes and sexes. Wild-type (WT) males exhibited arterial stiffening in vivo and ex vivo. Aortic remodeling with increased wall thickness, intralamellar distance, higher LOXL2, and collagen I and IV content was noted in WT males. Female mice did not exhibit increased PWV despite the onset of hypertension. LOXL2 depletion improved vascular reactivity and mechanics in hypertensive males. LOXL2 depletion improved aortic mechanics but worsened hypercontractility in females. Hypertensive cyclic strain contributed to LOXL2 upregulation in the cell-derived matrix in vascular smooth muscle cells (VSMCs) but not endothelial cells. LOXL2's catalytic function facilitated VSMC alignment in response to biomechanical strain. In conclusion, in males, arterial stiffening in hypertension is driven both by VSMC response and matrix remodeling. Females are protected from PWV elevation in hypertension. LOXL2 depletion is protective in males with improved mechanical and functional aortic properties. VSMCs are the primary source of LOXL2 in the aorta, and hypertension increases LOXL2 processing and shifts to collagen I accumulation. Overall, LOXL2 depletion offers protection in young hypertensive males and females.NEW & NOTEWORTHY We examined the effect of sex on the evolution of angiotensin II (ANG II)-induced hypertension and the role of lysyl oxidase-like 2 (LOXL2), an enzyme that catalyzes matrix cross linking. While ANG II led to hypertension and worsening vascular reactivity in both sexes, aortic remodeling and stiffening occurred only in males. LOXL2 depletion improved outcomes in males but not females. Thus males and females exhibit a distinct etiology of hypertension and LOXL2 is an effective target in males.
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Aminoácido Oxidorreductasas , Angiotensina II , Hipertensión , Ratones Endogámicos C57BL , Ratones Noqueados , Remodelación Vascular , Rigidez Vascular , Animales , Masculino , Femenino , Aminoácido Oxidorreductasas/metabolismo , Aminoácido Oxidorreductasas/genética , Hipertensión/inducido químicamente , Hipertensión/fisiopatología , Hipertensión/enzimología , Hipertensión/metabolismo , Hipertensión/patología , Factores Sexuales , Ratones , Músculo Liso Vascular/fisiopatología , Músculo Liso Vascular/enzimología , Músculo Liso Vascular/patología , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/efectos de los fármacos , Aorta/fisiopatología , Aorta/patología , Aorta/enzimología , Aorta/efectos de los fármacos , Aorta/metabolismo , Modelos Animales de Enfermedad , Células Cultivadas , Miocitos del Músculo Liso/enzimología , Miocitos del Músculo Liso/patología , Miocitos del Músculo Liso/metabolismo , Miocitos del Músculo Liso/efectos de los fármacosRESUMEN
Fibrosis is an important and essential reparative response to injury that, if left uncontrolled, results in the excessive synthesis, deposition, remodeling, and stiffening of the extracellular matrix, which is deleterious to organ function. Thus, the sustained activation of enzymes that catalyze matrix remodeling and cross linking is a fundamental step in the pathology of fibrotic diseases. Recent studies have implicated the amine oxidase lysyl oxidase like-2 (LOXL2) in this process and established significantly elevated expression of LOXL2 as a key component of profibrotic conditions in several organ systems. Understanding the relationship between LOXL2 and fibrosis as well as the mechanisms behind these relationships can offer significant insights for developing novel therapies. Here, we summarize the key findings that demonstrate the link between LOXL2 and fibrosis and inflammation, examine current therapeutics targeting LOXL2 for the treatment of fibrosis, and discuss future directions for experiments and biomedical engineering.
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Enfermedades Cardiovasculares , Proteína-Lisina 6-Oxidasa , Humanos , Proteína-Lisina 6-Oxidasa/genética , Enfermedades Cardiovasculares/genética , Fibrosis , Matriz ExtracelularRESUMEN
Semiliquidambar cathayensis Chang roots (SC) are traditional Chinese medicine for treating rheumatoid arthritis (RA). However, the effect and potential mechanism of SC remain unclear. This study aims to reveal the anti-RA constituents and mechanisms of SC based on network pharmacology, molecular docking, and adjuvant-induced arthritis (AIA) model rat experiment. In this work, 9â potential active constituents, including kaempferol, quercetin, naringenin, paeoniflorin, catechin, fraxin, gentianin, hesperetin, and ellagic acid 3,3',4-trimethyl ether, in SC crossed 65 target genes of RA. In addition, 28 core targets were enriched in inflammation and others, among which interleukin-17 (IL-17) and tumor necrosis factor (TNF) were the major targets. The binding of bio-constituents with IL-17 and TNF were performed using molecular docking. Rat experiment demonstrated that the extract of SC restored body weight loss, reduced arthritis score and the indices of thymus and spleen, alleviated ankle joint histopathology, decreased the levels of rheumatoid factor (RF), C-reactive protein (CRP), IL-17, TNF-α, IL-1ß, IL-6, cyclooxygenase-2 (COX-2), 5-lipoxygenase (5-LOX), and matrix metalloproteinase-2 (MMP-2), whereas elevated the levels of IL-4 and IL-10. Collectively, it was the first time to comprehensively reveal the anti-RA efficacy and mechanism of SC via suppressing the inflammatory pathway based on network pharmacology, molecular docking, and experimental verification, which provide chemical and pharmacological evidences for the clinical application of SC.
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Artritis Reumatoide , Medicamentos Herbarios Chinos , Ratas , Animales , Interleucina-17/uso terapéutico , Simulación del Acoplamiento Molecular , Metaloproteinasa 2 de la Matriz , Antiinflamatorios/farmacología , Farmacología en Red , Artritis Reumatoide/tratamiento farmacológico , Artritis Reumatoide/metabolismo , Factor de Necrosis Tumoral alfa , Medicamentos Herbarios Chinos/farmacologíaRESUMEN
Aquaporins (AQPs) and vasopressin type 2 receptor (V2R) play a crucial role in urine excretion and are widely used to explore novel diuretics. In this study, three phenylpropanoids including stachysoside A (L1), acteoside (L2), and glucopyranosyl (1 â 6) martynoside (L3) were isolated from Lagopsis supina (Steph. ex Willd.) lk. -Gal. ex Knorr. Their diuretic activity, mechanism, molecular docking, and structure-activity relationships were explored. The results suggest that L1, L2, and L3 exhibit acute (6 h) and prolonged (6 d) activities including increased urinary excretion volume, diuretic action, and diuretic activity, without affecting the urinary pH and minor altering the electrolyte balance in saline-loaded rats. Further, L1, L2, and L3 significantly reduced the levels of angiotensin II (Ang II), anti-diuretic hormone (ADH), and aldosterone (ALD), AQPs 1-4 and 7, and V2R, and remarkably elevated the atriopeptin (ANP) level. Besides, L1, L2, and L3 obviously suppressed mRNA and protein levels of AQPs 1-4 and 7, and V2R. The hypothetical binding modes of L1, L2, and L3 with these proteins were determined by molecular docking, and a tight structure-activity relationship was also proposed. Collectively, L1, L2, and L3 represent three natively novel phenylethanoid glycoside diuretics, which inhibit AQP and V2R-mediated molecular mechanisms. They are superior to furosemide as long-term diuretics.
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Diuréticos , Glicósidos , Ratas , Animales , Diuréticos/farmacología , Simulación del Acoplamiento Molecular , Glicósidos/farmacología , Furosemida/farmacología , Relación Estructura-ActividadRESUMEN
Vascular stiffening and its sequelae are major causes of morbidity and mortality in the elderly. The increasingly accepted concept of "smooth muscle cell (SMC) stiffness syndrome" along with matrix deposition has emerged in vascular biology to account for the mechanical phenotype of arterial aging, but the molecular targets remain elusive. In this study, using an unbiased proteomic analysis, we identified lysyl oxidase-like 2 (LOXL2) as a critical SMC mediator for age-associated vascular stiffening. We tested the hypothesis that loss of LOXL2 function is protective in aging-associated vascular stiffening. We determined that exogenous and endogenous nitric oxide markedly decreased LOXL2 abundance and activity in the extracellular matrix of isolated SMCs and LOXL2 endothelial cells suppress LOXL2 abundance in the aorta. In a longitudinal study, LOXL2+/- mice were protected from age-associated increase in pulse-wave velocity, an index of vascular stiffening, as occurred in littermate wild-type mice. Using isolated aortic segments, we found that LOXL2 mediates vascular stiffening in aging by promoting SMC stiffness, augmented SMC contractility, and vascular matrix deposition. Together, these studies establish LOXL2 as a nodal point for a new therapeutic approach to treat age-associated vascular stiffening. NEW & NOTEWORTHY Increased central vascular stiffness augments risk of major adverse cardiovascular events. Despite significant advances in understanding the genetic and molecular underpinnings of vascular stiffening, targeted therapy has remained elusive. Here, we show that lysyl oxidase-like 2 (LOXL2) drives vascular stiffening during aging by promoting matrix remodeling and vascular smooth muscle cell stiffening. Reduced LOXL2 expression protects mice from age-associated vascular stiffening and delays the onset of isolated systolic hypertension, a major consequence of stiffening.
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Aminoácido Oxidorreductasas/deficiencia , Enfermedades de la Aorta/enzimología , Músculo Liso Vascular/enzimología , Miocitos del Músculo Liso/enzimología , Remodelación Vascular , Rigidez Vascular , Factores de Edad , Aminoácido Oxidorreductasas/genética , Animales , Aorta Torácica/enzimología , Aorta Torácica/fisiopatología , Enfermedades de la Aorta/genética , Enfermedades de la Aorta/fisiopatología , Células Cultivadas , Técnicas de Cocultivo , Células Endoteliales/metabolismo , Matriz Extracelular/metabolismo , Femenino , Humanos , Masculino , Ratones Noqueados , Músculo Liso Vascular/fisiopatología , Óxido Nítrico/metabolismo , Comunicación Paracrina , Transducción de Señal , VasoconstricciónRESUMEN
The lysyl oxidase (LOX) family of enzymes regulates collagen cross-linking. LOX is upregulated in hypertension, increasing vascular stiffness. In vivo human research is sparse, as long-term LOX inhibition in animals causes vascular instability. Our aim was to evaluate the effects of LOX inhibition on cutaneous microvascular function to determine whether LOX function was upregulated in hypertensive humans. Four intradermal microdialysis fibers were placed in the forearm of 10 young [age: 24 ± 1 yr, mean arterial pressure (MAP): 87 ± 2 mmHg], 10 normotensive (age: 50 ± 2 yr, MAP: 84 ± 1 mmHg), and 10 hypertensive (age: 53 ± 2 yr, MAP: 112 ± 2 mmHg) subjects. Two sites were perfused with 10 mM ß-aminopropionitrile (BAPN) to inhibit LOX. The remaining two sites were perfused with lactated Ringer solution (control). A norepinephrine dose response (10-12-10-2 M) was performed to examine receptor-mediated vasoconstrictor function. A sodium nitroprusside dose response (10-8-10-1.3 M) was performed to examine vascular smooth muscle vasodilator function. Red blood cell flux was measured via laser-Doppler flowmetry and normalized to cutaneous vascular conductance (flux/MAP). LogEC50 values were calculated to determine changes in vasosensitivity. Skin tissue samples were analyzed for both extracellular matrix-bound and soluble LOX. LOX inhibition augmented vasoconstrictor sensitivity in young (control: -6.0 and BAPN: -7.1, P = 0.03) and normotensive (control: -4.8 and BAPN: -7.0, P = 0.01) but not hypertensive (control: -6.0 and BAPN: -6.1, P = 0.79) men and women. Relative to young subjects, extracellular matrix-bound LOX expression was higher in hypertensive subjects (young: 100 ± 8 and hypertensive: 162 ± 8, P = 0.002). These results suggest that upregulated LOX may contribute to the vascular stiffness and microvascular dysfunction characteristic in hypertension. NEW & NOTEWORTHY Matrix-bound lysyl oxidase (LOX) and LOX-like 2 expression are upregulated in the microvasculature of hypertensive men and women. Microvascular responsiveness to exogenous stimuli is altered with localized LOX inhibition in healthy men and women but not hypertensive adults. The LOX family differentially affects microvascular function in hypertensive and normotensive men and women.
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Aminopropionitrilo/administración & dosificación , Inhibidores Enzimáticos/administración & dosificación , Hipertensión/fisiopatología , Microcirculación/efectos de los fármacos , Microvasos/efectos de los fármacos , Proteína-Lisina 6-Oxidasa/antagonistas & inhibidores , Piel/irrigación sanguínea , Adulto , Aminoácido Oxidorreductasas/antagonistas & inhibidores , Aminoácido Oxidorreductasas/metabolismo , Presión Sanguínea , Femenino , Humanos , Hipertensión/diagnóstico , Masculino , Microdiálisis , Microvasos/enzimología , Microvasos/fisiopatología , Persona de Mediana Edad , Proteína-Lisina 6-Oxidasa/metabolismo , Vasoconstricción/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Adulto JovenRESUMEN
Hydrogen sulfide (H2S) has emerged as an important gasotransmitter in the vasculature. In this study, we tested the hypothesis that H2S contributes to coronary vasoregulation and evaluated the physiological relevance of two sources of H2S, namely, cystathionine-γ-lyase (CSE) and 3-mercaptypyruvate sulfertransferase (MPST). MPST was detected in human coronary artery endothelial cells as well as rat and mouse coronary artery; CSE was not detected in the coronary vasculature. Rat coronary artery homogenates produced H2S through the MPST pathway but not the CSE pathway in vitro. In vivo coronary vasorelaxation response was similar in CSE knockout mice, wild-type mice (WT), and WT mice treated with the CSE inhibitor propargylglycine, suggesting that CSE-produced H2S does not have a significant role in coronary vasoregulation in vivo. Ex vivo, the MPST substrate 3-mercaptopyruvate (3-MP) and H2S donor sodium hydrosulfide (NaHS) elicited similar coronary vasoreactivity responses. Pyruvate did not have any effects on vasoreactivity. The vasoactive effect of H2S appeared to be nitric oxide (NO) dependent: H2S induced coronary vasoconstriction in the presence of NO and vasorelaxation in its absence. Maximal endothelial-dependent relaxation was intact after 3-MP and NaHS induced an increase in preconstriction tone, suggesting that endothelial NO synthase activity was not significantly inhibited. In vitro, H2S reacted with NO, which may, in part explain the vasoconstrictive effects of 3-MP and NaHS. Taken together, these data show that MPST rather than CSE generates H2S in coronary artery, mediating its effects through direct modulation of NO. This has important implications for H2S-based therapy in healthy and diseased coronary arteries.
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Vasos Coronarios/enzimología , Cistationina gamma-Liasa/metabolismo , Sulfuro de Hidrógeno/metabolismo , Sulfurtransferasas/metabolismo , Animales , Células Cultivadas , Vasos Coronarios/efectos de los fármacos , Cistationina gamma-Liasa/antagonistas & inhibidores , Cistationina gamma-Liasa/deficiencia , Cistationina gamma-Liasa/genética , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/farmacología , Humanos , Cinética , Masculino , Ratones Noqueados , Óxido Nítrico/metabolismo , Ratas Sprague-Dawley , Transducción de Señal/efectos de los fármacos , Vasodilatación/efectos de los fármacos , Vasodilatadores/farmacologíaRESUMEN
A thermostable xylanase is encoded by xynA from fungus Thermomyces lanuginosus. The problem emerged from overexpression of xynA in Escherichia coli has been the formation of inclusion bodies. Here we describe the xynA was fused with the hyperosmotically inducible periplasmic protein of E. coli, OsmY. The fusion protein OsmY-xynA was expressed as almost all soluble form. The soluble expression level of fusion protein reached 98±6U/ml when cells containing pET-OsmY-xynA were expressed without IPTG induction at 37°C. The induction is probably due to auto-induction due to lactose in the medium (Studier (2005) [21]). The cells harboring pET-OsmY-xynA expressed an activity level about 24 times higher than that expressed from pET-20b-xynA. Xylanase activity was observed in the extracellular (36±1.3U/ml) and the periplasmic (42±4U/ml) when cells containing pET-OsmY-xynA were induced without IPTG addition. After the cold osmotic shock procedure followed by nickel affinity chromatography, the purified fusion protein showed a single band on SDS-PAGE gel with a molecular mass of 44kDa. The purified fusion enzyme exhibited the highest activity at 65°C and pH 6.0.
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Endo-1,4-beta Xilanasas/biosíntesis , Ascomicetos/enzimología , Endo-1,4-beta Xilanasas/genética , Endo-1,4-beta Xilanasas/aislamiento & purificación , Estabilidad de Enzimas , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Vectores Genéticos , Calor , Proteínas de Unión Periplasmáticas/genética , Proteínas Recombinantes de Fusión/biosíntesis , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/aislamiento & purificación , SolubilidadRESUMEN
BACKGROUND: Hypertension, a disease with known sexual dimorphism, accelerates aging associated arterial stiffening, in part due to the activation of matrix remodeling caused by increased biomechanical load. In this study, we tested the effect of biological sex and the role of the matrix remodeling enzyme lysyl oxidase like 2 (LOXL2) in hypertension induced arterial stiffening. METHODS: Angiotensin II (Ang II) was delivered using osmotic pumps in Loxl2+/- and WT male and female mice. Blood pressure and pulse wave velocity (PWV) were measured noninvasively to assess hypertension and aortic stiffness. Wire myography and uniaxial tensile testing were used to test aortic vasoreactivity and mechanical properties. Aortic wall composition was examined by histology and Western blotting. The effect of biomechanical strain on LOXL2 expression and secretion by vascular smooth muscle (VSMC) and endothelial cells (EC) was evaluated by uniaxial cyclic stretching of cultured cells. The role of LOXL2 catalytic function on VSMC alignment in response to mechanical loading was determined with LOXL2 inhibition and knockout. RESULTS: Ang II infusion induced hypertension in WT and Loxl2+/- mice of both sexes and increased PWV in WT males but not in Loxl2+/- males, WT females, or Loxl2+/- females. LOXL2 depletion protected males from Ang II mediated potentiation of vasoconstriction but worsened in females and improved aortic mechanical properties in both sexes. Histological analysis showed increased aortic wall thickness in hypertensive WT males but not females and increased intralamellar distance in both sexes, that was ameliorated in Loxl2+/- mice. Western blotting revealed increased collagen I, decreased collagen IV, and increased LOXL2 accumulation and processing in hypertensive mice. Hypertensive cyclic strain contributed to LOXL2 upregulation in the cell-derived matrix in VSMCs but not ECs. LOXL2 catalytic function facilitated VSMC alignment in response to biomechanical strain. CONCLUSIONS: In males, arterial stiffening in hypertension is driven both by VSMC response and matrix remodeling. Females exhibit a delayed onset of Ang II-induced hypertension with minimal ECM remodeling but with VSMC dysfunction. LOXL2 depletion ameliorates arterial stiffening and preserves functional contractility and aortic structure in male hypertensive mice. LOXL2 depletion improves aortic mechanics but worsens aortic contractility in hypertensive females. VSMCs are the primary source of LOXL2 in the aorta and hypertension increases LOXL2 processing and shifts to collagen I accumulation. Overall, LOXL2 depletion offers protection in young hypertensive males and females.
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ETHNOPHARMACOLOGICAL RELEVANCE: Hosta plantaginea (Lam.) Aschers flower is an important Mongolian medicine beneficial in the treatment of chronic prostatitis (CP) in the absence of scientific evidence. AIM OF THE STUDY: The aim of this study was to reveal the therapeutical effects and potential mechanisms of H. plantaginea flowers extract (HP) and its different polarity fractions (HPAâ¼D) on autoimmune CP (ACP) model rats. MATERIALS AND METHODS: Sprague-Dawley male rats were randomly assigned to 13 groups (n = 6/group). Except the sham group, all rats were injected with a mixture of prostate antigen and complete Freund's adjuvant on days 0, 7, and 21 to establish ACP model rats. Afterwards, ACP model rats were orally gavaged with HP or HPAâ¼D (1 and 4 g/kg of raw herbal material) or positive drug (Prostat, 200 mg/kg) daily from day 21 to day 50 for 30 days, while the sham and model groups were treated simultaneously with isopyknic of 0.3% sodium carboxymethyl cellulose. Histopathological analysis, biochemical parameters, and protein expression of prostate tissues were investigated. RESULTS: In comparison with the model group, all fraction groups experienced improved CP effects, including restored body weight, reduced prostate gland edema and prostate index, decreased prostatic leukocytes, increased prostatic lecithin bodies, and alleviated histopathological damage to prostate tissue. Furthermore, all fraction groups markedly inhibited the phosphorylated protein of nuclear factor kappa-B p65 (NF-κB p65), NF-κB inhibitor alpha (IκBα), c-Jun N-terminal kinase (JNK), p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase (Erk), just another kinase 1 (JAK1), signal transducer and activator of transcription 3 (STAT3), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) than the model group. CONCLUSION: All fractions of HP exerted significant anti-CP effects by inhibiting NF-κB, MAPKs, JAK-STAT and PI3K-Akt pathways in ACP model rats. These findings provide scientific evidence that H. plantaginea flowers can be used as a pivotal Mongolian medicine in clinical applications for the treatment of CP.
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Hosta , Prostatitis , Animales , Masculino , Ratas , Flores/metabolismo , Hosta/metabolismo , Medicina Tradicional Mongoliana , FN-kappa B/metabolismo , Fosfatidilinositol 3-Quinasa/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Ratas Sprague-Dawley , Transducción de SeñalRESUMEN
Lysyl oxidase-like 2 (LOXL2) has been identified as an essential mediator of extracellular matrix (ECM) remodeling in several disease processes including cardiovascular disease. Thus, there is growing interest in understanding the mechanisms by which LOXL2 is regulated in cells and tissue. While LOXL2 occurs both in full length and processed forms in cells and tissue, the precise identity of the proteases that process LOXL2 and the consequences of processing on LOXL2's function remain incompletely understood. Here we show that Factor Xa (FXa) is a protease that processes LOXL2 at Arg-338. Processing by FXa does not affect the enzymatic activity of soluble LOXL2. However, in situ in vascular smooth muscle cells, LOXL2 processing by FXa results in decreased cross-linking activity in the ECM and shifts substrate preference of LOXL2 from type IV collagen to type I collagen. Additionally, processing by FXa increases the interactions between LOXL2 and prototypical LOX, suggesting a potential compensatory mechanism to preserve total LOXs activity in the vascular ECM. FXa expression is prevalent in various organ systems and shares similar roles in fibrotic disease progression as LOXL2. Thus, LOXL2 processing by FXa could have significant implications in pathologies where LOXL2 is involved.
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Factor Xa , Proteína-Lisina 6-Oxidasa , Proteína-Lisina 6-Oxidasa/metabolismo , Factor Xa/metabolismo , Matriz Extracelular/metabolismo , Miocitos del Músculo Liso/metabolismoRESUMEN
Background: Conduit pulmonary arterial stiffening and the resultant increase in pulmonary vascular impedance has emerged as an important underlying driver of pulmonary arterial hypertension (PAH). Given that matrix deposition is central to vascular remodeling, we evaluated the role of the collagen crosslinking enzyme lysyl oxidase like 2 (LOXL2) in this study. Methods and Results: Human pulmonary artery smooth muscle cells (PASMCs) subjected to hypoxia showed increased LOXL2 secretion. LOXL2 activity and expression were markedly higher in primary PASMCs isolated from pulmonary arteries of the rat Sugen 5416 + hypoxia (SuHx) model of severe PH. Similarly, LOXL2 protein and mRNA levels were increased in pulmonary arteries (PA) and lungs of rats with PH (SuHx and monocrotaline (MCT) models). Pulmonary arteries (PAs) isolated from rats with PH exhibited hypercontractility to phenylephrine and attenuated vasorelaxation elicited by acetylcholine, indicating severe endothelial dysfunction. Tensile testing revealed a a significant increase in PA stiffness in PH. Treatment with PAT-1251, a novel small-molecule LOXL2 inhibitor, improved active and passive properties of the PA ex vivo. There was an improvement in right heart function as measured by right ventricular pressure volume loops in-vivo with PAT-1251. Importantly PAT-1251 treatment ameliorated PH, resulting in improved pulmonary artery pressures, right ventricular remodeling, and survival. Conclusion: Hypoxia induced LOXL2 activation is a causal mechanism in pulmonary artery stiffening in PH, as well as pulmonary artery mechanical and functional decline. LOXL2 inhibition with PAT-1251 is a promising approach to improve pulmonary artery pressures, right ventricular elastance, cardiac relaxation, and survival in PAH. New & Noteworthy: Pulmonary arterial stiffening contributes to the progression of PAH and the deterioration of right heart function. This study shows that LOXL2 is upregulated in rat models of PH. LOXL2 inhibition halts pulmonary vascular remodeling and improves PA contractility, endothelial function and improves PA pressure, resulting in prolonged survival. Thus, LOXL2 is an important mediator of PA remodeling and stiffening in PH and a promising target to improve PA pressures and survival in PH.
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Hypoxia in the neonatal period is associated with early manifestations of adverse cardiovascular health in adulthood including higher risk of hypertension and atherosclerosis. We hypothesize that this occurs due to activation of lysyl oxidases (LOXs) and the remodeling of the large conduit vessels, leading to early arterial stiffening. Newborn C57Bl/6 mice were exposed to hypoxia (FiO2 = 11.5%) from postnatal day 1 (P1) to postnatal day 11 (P11), followed by resumption of normoxia. Controls were maintained in normoxia. Using in vivo (pulse wave velocity; PWV) and ex vivo (tensile testing) arterial stiffness indexes, we determined that mice exposed to neonatal hypoxia had significantly higher arterial stiffness compared with normoxia controls by young adulthood (P60), and it increased further by P120. Echocardiography performed at P60 showed that mice exposed to hypoxia displayed a compensated dilated cardiomyopathy. Western blotting revelated that neonatal hypoxia accelerated age-related increase in LOXL2 protein expression in the aorta and elevated LOXL2 expression in the PA at P11 with a delayed decay toward normoxic controls. In the heart and lung, gene and protein expression of LOX/LOXL2 were upregulated at P11, with a delayed decay when compared to normoxic controls. Neonatal hypoxia results in a significant increase in arterial stiffness in early adulthood due to aberrant LOX/LOXL2 expression. This suggests an acceleration in the mechanical decline of the cardiovascular system, that contributes to increased risk of hypertension in young adults exposed to neonatal hypoxia that may increase susceptibility to further insults.
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Hipertensión , Rigidez Vascular , Ratones , Animales , Proteína-Lisina 6-Oxidasa/genética , Proteína-Lisina 6-Oxidasa/metabolismo , Análisis de la Onda del Pulso , Hipoxia , Aorta/metabolismo , Rigidez Vascular/fisiologíaRESUMEN
Widespread application of synthetic dyes could generate colored wastewaters causing a range of serious environmental problems. Due to the complex nature of effluents from textile industries, it is difficult to obtain satisfactory treatment of dyes-contaminated wastewater using one single method. Biohybrids coupling of photocatalysts and biocatalysts have great potential in environmental purification. However, how to select suitable organisms and enhance the hybrid's catalytic activities remain challenging. Here, a novel biohybrid system (Clostridium thermocellum-CdS), created for light-driven biodecolorization under thermophilic treatment by using non-photosynthetic microorganism C. thermocellum self-photosensitized with CdS nanoparticles was established. The biohybrids exhibited remarkable decolorization effects on triphenylmethane dyes. The highest decolorization rate was 0.206 min-1. More importantly, enhanced catalytic activities of cadmium sulfide (CdS)-based biohybrids by controlling the particle sizes of semiconductors were demonstrated. Biohybrids systems (Clostridium thermocellum-CdS) through the self-precipitation of CdS with different particle sizes not only showed dramatic changes in the optical properties but also exhibited a very different decolorization rate. This work can not only further broaden targeted applications of CdS-based biohybrids but also demonstrate a promising route for improving biohybrids corresponding photocatalytic capabilities through in situ precipitation CdS with different particle sizes.
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Compuestos de Cadmio , Clostridium thermocellum , Colorantes , Sulfuros , Compuestos de Tritilo , Aguas ResidualesRESUMEN
Kaempferol 3-O-(2G-glucosylrutinoside)-7-O-glucoside (KGG) has isolated from Hosta plantaginea flowers and possessed an inhibitory effect on cyclooxygenase 2 (COX-2), could be effective in inhibiting inflammation. However, the anti-inflammatory activity and mechanism of KGG remain unknown. In this study, for the first time, the anti-inflammatory effect of KGG and its potential molecular mechanisms were explored in cells. KGG had no cytotoxicity at concentrations of 1.25, 2.5, 5, 10, 20, and 40 µM by Cell Counting kit-8 assay in RAW 264.7 cells. Besides, KGG concentration-dependently (1.25, 2.5, and 5 µM) inhibited secretions of nitric oxide (NO), prostaglandin E2 (PGE2), tumor necrosis factor α (TNF-α), interleukin 1ß (IL-1ß), and IL-6 in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells. Western blot showed that the phosphorylation of nuclear factor kappa-B (NF-κB) p65, inhibitor of NF-κB (IκB), p38 MAPK, c-Jun N-terminal kinases (JNK), extracellular signal-regulated kinase (Erk), and protein kinase B (Akt), together with inducible nitric oxide synthase (iNOS) and COX-2 were significantly attenuated by KGG (1.25, 2.5, and 5 µM) in a concentration-dependent relationship. Meanwhile, KGG remarkably enhanced the protein expression of IκB. Taken together, KGG may be one of bioactive phytochemicals from H. plantaginea flowers, and be an anti-inflammatory agent via inhibiting NF-κB, mitogen-activated protein kinases (MAPKs), and Akt signaling pathways.
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Hosta , FN-kappa B , Animales , Antiinflamatorios/metabolismo , Antiinflamatorios/farmacología , Ciclooxigenasa 2/metabolismo , Flores , Glucósidos/metabolismo , Glucósidos/farmacología , Hosta/metabolismo , Proteínas I-kappa B/metabolismo , Quempferoles/farmacología , Lipopolisacáridos/metabolismo , Lipopolisacáridos/farmacología , Macrófagos , Ratones , Proteínas Quinasas Activadas por Mitógenos/metabolismo , FN-kappa B/metabolismo , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Células RAW 264.7RESUMEN
Background: Lagopsis supina (Steph. ex Willd.) Ikonn.-Gal. has been a traditional Chinese medicine (TCM) for the treatment of blood stasis, inflammation, and diuresis. Moreover, Huo Xue Li Shui theory was an important TCM theory that used to treat many ailments. Nevertheless, the scientific connotation of this theory has not been clearly elucidated so far. Aim of the study: The aim of this study was to explore the scientific connotation of Huo Xue Li Shui with promoting blood circulation and removing blood stasis (PBCRBS), anti-inflammatory and diuretic effects in trauma-induced blood stasis model (TBSM) rats, taking microporous adsorption resin with water (LSB) and 30% ethanol (LSC) elution fractions from L. supina as a classical demonstration. Materials and methods: 48 rats were randomly assigned into six groups (n = 8/group): the control group, the model group, and model groups treatment with LSB or LSC. The biochemical parameters and protein expression were measured using kit method and Western blot assay, respectively. Results: Both LSB and LSC were effective in elevating body weight, food consumption, and water intake in model rats. In PBCRBS efficacy evaluation, LSB and LSC remarkably improved histopathological tissues. On the other hand, LSB and LSC prominently decreased the contents of plasma viscosity, platelet aggregation rate, thrombin time, prothrombin time, activated partial thromboplastin time (APTT), fibrinogen, thromboxane B2, thromboxane B2/6-keto-prostaglandin F1α, urokinase-type plasminogen activator (u-PA), plasminogen activator inhibitor-1(PAI-1), PAI-1/tissue-type plasminogen activator (t-PA), and PAI-1/u-PA, while significantly enhanced the contents of antithrombin III, 6-keto-prostaglandin F1α, and t-PA. In parallel, LSB and LSC obviously down-regulated the levels of tumor necrosis factor alpha (TNF-α), interleukin-6 (IL-6), and IL-8, and remarkably up-regulated the level of IL-10. In determining diuretic activities, LSB and LSC prominently elevated urinary excretion volume and the level of atriopeptin, and remarkably reduced the levels of angiotensin II, anti-diuretic hormone, aldosterone, aquaporin 1 (AQP1), AQP2, and AQP3. In addition, LSB and LSC clearly suppressed protein expressions of AQP1, AQP2, and AQP3. Finally, LSB and LSC did not caused urinary pH, Na+, and Cl- electrolytes and had minor effects on K+ and Ca2+ concentrations. Conclusions: LSB and LSC exhibited prominent PBCRBS, anti-inflammatory, and diuretic effects in TBSM rats, thereby supported the traditional folk use of L. supina. This study successfully provided an experimental basis for the scientific connotation of Huo Xue Li Shui.
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Heavy metals are considered as hazardous substances to human because of their toxicity, persistence and bioaccumulation, and the level in serum is an important factor to evaluate the caused health risk, which depends on efficient and sensitive analytical methods. Here, a triple signal-amplified electrochemical sensing platform based on metal-dependent DNAzymes was fabricated for sensitive determination of heavy metals in serum (copper as a model target). Under the optimized conditions, the proposed method showed good sensitivity (limit of detection, 0.33 fM for Cu2+) with excellent selectivity and stability, which is ascribed to: (i) tetrahedral DNA nanostructures (TDNs) that was used as a promising scaffold to adjust the selective transformation between heterogeneous and homogeneous reactions, preventing the nonspecific binding of electrodes surface and DNA probes; (ii) the magnetic beads (MBs) used which led to signal amplification and decreased background owing to its excellent properties of extracting equivalent targets from the complex samples; (iii) two signal amplification strategy of catalytic hairpin assembly (CHA) and hybridization chain reaction (HCR). In addition, the proposed sensing platform displayed satisfactory accuracy through the validation with inductively coupled plasma-mass spectrometry (ICP-MS) and a spike-recovery analysis (recoveries, 87.92-111.61%; RSD, 4.89-8.85%), indicating the great potential for rapid and sensitive detection of Cu2+ or other metal ions.
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Técnicas Biosensibles , Metales Pesados , Cobre , Técnicas Electroquímicas , Humanos , Límite de Detección , Hibridación de Ácido NucleicoRESUMEN
The lysyl oxidase family of enzymes (LOXs) catalyze oxidative deamination of lysine side chains on collagen and elastin to initialize cross-linking that is essential for the formation of the extracellular matrix (ECM). Elevated expression of LOXs is highly associated with diverse disease processes. To date, the inability to detect total LOX catalytic function in situ has limited the ability to fully elucidate the role of LOXs in pathobiological mechanisms. Using LOXL2 as a representative member of the LOX family, we developed an in situ activity assay by utilizing the strong reaction between hydrazide and aldehyde to label the LOX-catalyzed allysine (-CHO) residues with biotin-hydrazide. The biotinylated ECM proteins are then labeled via biotin-streptavidin interaction and detected by fluorescence microscopy. This assay detects the total LOX activity in situ for both overexpressed and endogenous LOXs in cells and tissue samples and can be used for studies of LOXs as therapeutic targets.
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Pruebas de Enzimas/métodos , Proteína-Lisina 6-Oxidasa/metabolismo , Aminoácido Oxidorreductasas/genética , Aminoácido Oxidorreductasas/metabolismo , Animales , Aorta/enzimología , Biocatálisis , Western Blotting , Línea Celular , Fluorometría/métodos , Humanos , Masculino , Ratones Endogámicos C57BL , Ratones Noqueados , Proteína-Lisina 6-Oxidasa/genética , RatasRESUMEN
Tissue transglutaminase (TG2), a multifunctional protein of the transglutaminase family, has putative transamidation-independent functions in aging-associated vascular stiffening and dysfunction. Developing preclinical models will be critical to fully understand the physiologic relevance of TG2's transamidation-independent activity and to identify the specific function of TG2 for therapeutic targeting. Therefore, in this study, we harnessed CRISPR-Cas9 gene editing technology to introduce a mutation at cysteine 277 in the active site of the mouse Tgm2 gene. Heterozygous and homozygous Tgm2-C277S mice were phenotypically normal and were born at the expected Mendelian frequency. TG2 protein was ubiquitously expressed in the Tgm2-C277S mice at levels similar to those of wild-type (WT) mice. In the Tgm2-C277S mice, TG2 transglutaminase function was successfully obliterated, but the transamidation-independent functions ascribed to GTP, fibronectin, and integrin binding were preserved. In vitro, a remodeling stimulus led to the significant loss of vascular compliance in WT mice, but not in the Tgm2-C277S or TG2-/- mice. Vascular stiffness increased with age in WT mice, as measured by pulse-wave velocity and tensile testing. Tgm2-C277S mice were protected from age-associated vascular stiffening, and TG2 knockout yielded further protection. Together, these studies show that TG2 contributes significantly to overall vascular modulus and vasoreactivity independent of its transamidation function, but that transamidation activity is a significant cause of vascular matrix stiffening during aging. Finally, the Tgm2-C277S mice can be used for in vivo studies to explore the transamidation-independent roles of TG2 in physiology and pathophysiology.