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1.
Cell Mol Life Sci ; 80(9): 265, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37615749

RESUMO

Transient receptor potential cation channel-6 (TRPC6) gene mutations cause familial focal segmental glomerulosclerosis (FSGS), which is inherited as an autosomal dominant disease. In patients with TRPC6-related FSGS, all mutations map to the N- or C-terminal TRPC6 protein domains. Thus far, the majority of TRPC6 mutations are missense resulting in increased or decreased calcium influx; however, the fundamental molecular mechanisms causing cell injury and kidney pathology are unclear. We report a novel heterozygous TRPC6 mutation (V691Kfs*) in a large kindred with no signs of FSGS despite a largely truncated TRPC6 protein. We studied the molecular effects of V691Kfs* TRPC6 mutant using the tridimensional cryo-EM structure of the tetrameric TRPC6 protein. The results indicated that V691 is localized at the pore-forming transmembrane region affecting the ion conduction pathway, and predicted that V691Kfs* causes closure of the ion-conducting pathway leading to channel inactivation. We assessed the impact of V691Kfs* and two previously reported TRPC6 disease mutants (P112Q and G757D) on calcium influx in cells. Our data show that the V691Kfs* fully inactivated the TRCP6 channel-specific calcium influx consistent with a complete loss-of-function phenotype. Furthermore, the V691Kfs* truncation exerted a dominant negative effect on the full-length TRPC6 proteins. In conclusion, the V691Kfs* non-functional truncated TRPC6 is not sufficient to cause FSGS. Our data corroborate recently characterized TRPC6 loss-of-function and gain-of-function mutants suggesting that one defective TRPC6 gene copy is not sufficient to cause FSGS. We underscore the importance of increased rather than reduced calcium influx through TRPC6 for podocyte cell death.


Assuntos
Glomerulosclerose Segmentar e Focal , Humanos , Glomerulosclerose Segmentar e Focal/genética , Canal de Cátion TRPC6/genética , Cálcio , Mutação com Perda de Função , Mutação/genética
2.
Nature ; 551(7682): 585-589, 2017 11 30.
Artigo em Inglês | MEDLINE | ID: mdl-29143823

RESUMO

A Western lifestyle with high salt consumption can lead to hypertension and cardiovascular disease. High salt may additionally drive autoimmunity by inducing T helper 17 (TH17) cells, which can also contribute to hypertension. Induction of TH17 cells depends on gut microbiota; however, the effect of salt on the gut microbiome is unknown. Here we show that high salt intake affects the gut microbiome in mice, particularly by depleting Lactobacillus murinus. Consequently, treatment of mice with L. murinus prevented salt-induced aggravation of actively induced experimental autoimmune encephalomyelitis and salt-sensitive hypertension by modulating TH17 cells. In line with these findings, a moderate high-salt challenge in a pilot study in humans reduced intestinal survival of Lactobacillus spp., increased TH17 cells and increased blood pressure. Our results connect high salt intake to the gut-immune axis and highlight the gut microbiome as a potential therapeutic target to counteract salt-sensitive conditions.


Assuntos
Microbioma Gastrointestinal/efeitos dos fármacos , Lactobacillus/efeitos dos fármacos , Lactobacillus/isolamento & purificação , Cloreto de Sódio/farmacologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Animais , Autoimunidade/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/induzido quimicamente , Encefalomielite Autoimune Experimental/microbiologia , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/terapia , Fezes/microbiologia , Humanos , Hipertensão/induzido quimicamente , Ácidos Indolacéticos/metabolismo , Indóis/metabolismo , Intestinos/citologia , Intestinos/efeitos dos fármacos , Intestinos/imunologia , Intestinos/microbiologia , Lactobacillus/imunologia , Ativação Linfocitária/efeitos dos fármacos , Contagem de Linfócitos , Masculino , Camundongos , Projetos Piloto , Cloreto de Sódio/administração & dosagem , Simbiose , Células Th17/citologia , Triptofano/metabolismo
3.
Int J Mol Sci ; 23(12)2022 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-35743312

RESUMO

Metabolic syndrome is a significant worldwide public health challenge and is inextricably linked to adverse renal and cardiovascular outcomes. The inhibition of the transient receptor potential cation channel subfamily C member 6 (TRPC6) has been found to ameliorate renal outcomes in the unilateral ureteral obstruction (UUO) of accelerated renal fibrosis. Therefore, the pharmacological inhibition of TPRC6 could be a promising therapeutic intervention in the progressive tubulo-interstitial fibrosis in hypertension and metabolic syndrome. In the present study, we hypothesized that the novel selective TRPC6 inhibitor SH045 (larixyl N-methylcarbamate) ameliorates UUO-accelerated renal fibrosis in a New Zealand obese (NZO) mouse model, which is a polygenic model of metabolic syndrome. The in vivo inhibition of TRPC6 by SH045 markedly decreased the mRNA expression of pro-fibrotic markers (Col1α1, Col3α1, Col4α1, Acta2, Ccn2, Fn1) and chemokines (Cxcl1, Ccl5, Ccr2) in UUO kidneys of NZO mice compared to kidneys of vehicle-treated animals. Renal expressions of intercellular adhesion molecule 1 (ICAM-1) and α-smooth muscle actin (α-SMA) were diminished in SH045- versus vehicle-treated UUO mice. Furthermore, renal inflammatory cell infiltration (F4/80+ and CD4+) and tubulointerstitial fibrosis (Sirius red and fibronectin staining) were ameliorated in SH045-treated NZO mice. We conclude that the pharmacological inhibition of TRPC6 might be a promising antifibrotic therapeutic method to treat progressive tubulo-interstitial fibrosis in hypertension and metabolic syndrome.


Assuntos
Hipertensão , Nefropatias , Síndrome Metabólica , Obstrução Ureteral , Animais , Modelos Animais de Doenças , Fibrose , Hipertensão/metabolismo , Rim/metabolismo , Nefropatias/etiologia , Nefropatias/genética , Síndrome Metabólica/complicações , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/metabolismo , Camundongos , Camundongos Obesos , Nova Zelândia , Obesidade/complicações , Obesidade/tratamento farmacológico , Obesidade/metabolismo , Canal de Cátion TRPC6/metabolismo , Obstrução Ureteral/complicações , Obstrução Ureteral/tratamento farmacológico , Obstrução Ureteral/genética
4.
Circulation ; 142(2): 133-149, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32524868

RESUMO

BACKGROUND: High blood pressure is the primary risk factor for cardiovascular death worldwide. Autosomal dominant hypertension with brachydactyly clinically resembles salt-resistant essential hypertension and causes death by stroke before 50 years of age. We recently implicated the gene encoding phosphodiesterase 3A (PDE3A); however, in vivo modeling of the genetic defect and thus showing an involvement of mutant PDE3A is lacking. METHODS: We used genetic mapping, sequencing, transgenic technology, CRISPR-Cas9 gene editing, immunoblotting, and fluorescence resonance energy transfer. We identified new patients, performed extensive animal phenotyping, and explored new signaling pathways. RESULTS: We describe a novel mutation within a 15 base pair (bp) region of the PDE3A gene and define this segment as a mutational hotspot in hypertension with brachydactyly. The mutations cause an increase in enzyme activity. A CRISPR/Cas9-generated rat model, with a 9-bp deletion within the hotspot analogous to a human deletion, recapitulates hypertension with brachydactyly. In mice, mutant transgenic PDE3A overexpression in smooth muscle cells confirmed that mutant PDE3A causes hypertension. The mutant PDE3A enzymes display consistent changes in their phosphorylation and an increased interaction with the 14-3-3θ adaptor protein. This aberrant signaling is associated with an increase in vascular smooth muscle cell proliferation and changes in vessel morphology and function. CONCLUSIONS: The mutated PDE3A gene drives mechanisms that increase peripheral vascular resistance causing hypertension. We present 2 new animal models that will serve to elucidate the underlying mechanisms further. Our findings could facilitate the search for new antihypertensive treatments.


Assuntos
Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/genética , Estudos de Associação Genética , Predisposição Genética para Doença , Hipertensão/genética , Mutação , Alelos , Substituição de Aminoácidos , Animais , Animais Geneticamente Modificados , Pressão Arterial , Biomarcadores/sangue , Biomarcadores/urina , Braquidactilia/diagnóstico , Braquidactilia/genética , Sistemas CRISPR-Cas , Nucleotídeo Cíclico Fosfodiesterase do Tipo 3/metabolismo , Análise Mutacional de DNA , Modelos Animais de Doenças , Ativação Enzimática , Marcação de Genes , Estudos de Associação Genética/métodos , Genótipo , Imuno-Histoquímica , Isoenzimas , Masculino , Linhagem , Fenótipo , Radiografia , Ratos , Sistema Renina-Angiotensina/genética
5.
Inorg Chem ; 60(23): 18141-18153, 2021 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-34784207

RESUMO

The oxygen nonstoichiometry, δ, and oxidation enthalpy, ΔHox, of double perovskites RBaCo2O6-δ (R = Sm or Eu) were simultaneously measured depending on the temperature and oxygen partial pressure, pO2. Theoretical equations for ΔHox(T, δ) and pO2(T, δ) were derived from the defect structure model based on the oxygen exchange and cobalt disproportionation reactions. These equations were fitted independently to each of the experimental ΔHox(T, δ) and pO2(T, δ) data sets. The resulting enthalpies of defect reactions were found to be almost the same irrespective of the calculation method. In other words, the models, describing satisfactorily the data, can be used to calculate both compositional dependences and redox thermodynamics of RBaCo2O6-δ (R = Sm or Eu). In addition, from the previously published data and the data presented here, trends were determined in the defect reaction thermodynamics of RBaCo2O6-δ (R = La, Pr, Nd, Sm, Eu, Gd, or Y). Drop calorimetric measurements were performed in air to obtain enthalpy increments for RBaCo2O6-δ (R = Sm or Eu) with variable oxygen content because the samples lost oxygen upon being heated in the calorimetric cell. As-obtained data were used to calculate the functional dependences of enthalpy increments of EuBaCo2O5.56 and SmBaCo2O5.6 with a constant oxygen content. In addition, as an example of practical application-oriented calculations for solar energy conversion and oxygen storage, the performances at equilibrium of RBaCo2O6-δ (R = Pr, Sm, Eu, or Gd) were evaluated and compared to those of SrFeO3-δ as a reference material.

6.
Angew Chem Int Ed Engl ; 60(34): 18694-18703, 2021 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-34009717

RESUMO

We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated. The compounds are cyclic peptides with a unique peptide core and several remarkable structural features, including unusual positions of d-amino acids, lack of the Ca2+ -binding Asp-X-Asp-Gly (DXDG) motif, tyrosine glycosylation with arabinose, presence of 2-amino-4-hydroxy-4-phenylbutyric acid (Ahpb) and chlorinated kynurenine (ClKyn), and N-acylation of the ornithine side chain. Gausemycins have pronounced activity against Gram-positive bacteria. Mechanistic studies highlight significant differences compared to known glyco- and lipopeptides. Gausemycins exhibit only slight Ca2+ -dependence of activity and induce no pore formation at low concentrations. Moreover, there is no detectable accumulation of cell wall biosynthesis precursors under treatment with gausemycins.


Assuntos
Lipoglicopeptídeos/isolamento & purificação , Streptomyces/química , Lipoglicopeptídeos/química , Conformação Molecular
7.
Circulation ; 139(11): 1407-1421, 2019 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-30586752

RESUMO

BACKGROUND: Arterial hypertension and its organ sequelae show characteristics of T cell-mediated inflammatory diseases. Experimental anti-inflammatory therapies have been shown to ameliorate hypertensive end-organ damage. Recently, the CANTOS study (Canakinumab Antiinflammatory Thrombosis Outcome Study) targeting interleukin-1ß demonstrated that anti-inflammatory therapy reduces cardiovascular risk. The gut microbiome plays a pivotal role in immune homeostasis and cardiovascular health. Short-chain fatty acids (SCFAs) are produced from dietary fiber by gut bacteria and affect host immune homeostasis. Here, we investigated effects of the SCFA propionate in 2 different mouse models of hypertensive cardiovascular damage. METHODS: To investigate the effect of SCFAs on hypertensive cardiac damage and atherosclerosis, wild-type NMRI or apolipoprotein E knockout-deficient mice received propionate (200 mmol/L) or control in the drinking water. To induce hypertension, wild-type NMRI mice were infused with angiotensin II (1.44 mg·kg-1·d-1 subcutaneous) for 14 days. To accelerate the development of atherosclerosis, apolipoprotein E knockout mice were infused with angiotensin II (0.72 mg·kg-1·d-1 subcutaneous) for 28 days. Cardiac damage and atherosclerosis were assessed using histology, echocardiography, in vivo electrophysiology, immunofluorescence, and flow cytometry. Blood pressure was measured by radiotelemetry. Regulatory T cell depletion using PC61 antibody was used to examine the mode of action of propionate. RESULTS: Propionate significantly attenuated cardiac hypertrophy, fibrosis, vascular dysfunction, and hypertension in both models. Susceptibility to cardiac ventricular arrhythmias was significantly reduced in propionate-treated angiotensin II-infused wild-type NMRI mice. Aortic atherosclerotic lesion area was significantly decreased in propionate-treated apolipoprotein E knockout-deficient mice. Systemic inflammation was mitigated by propionate treatment, quantified as a reduction in splenic effector memory T cell frequencies and splenic T helper 17 cells in both models, and a decrease in local cardiac immune cell infiltration in wild-type NMRI mice. Cardioprotective effects of propionate were abrogated in regulatory T cell-depleted angiotensin II-infused mice, suggesting the effect is regulatory T cell-dependent. CONCLUSIONS: Our data emphasize an immune-modulatory role of SCFAs and their importance for cardiovascular health. The data suggest that lifestyle modifications leading to augmented SCFA production could be a beneficial nonpharmacological preventive strategy for patients with hypertensive cardiovascular disease.


Assuntos
Anti-Inflamatórios/farmacologia , Doenças da Aorta/tratamento farmacológico , Arritmias Cardíacas/prevenção & controle , Aterosclerose/tratamento farmacológico , Cardiomegalia/prevenção & controle , Hipertensão/tratamento farmacológico , Propionatos/farmacologia , Angiotensina II , Animais , Doenças da Aorta/genética , Doenças da Aorta/imunologia , Doenças da Aorta/patologia , Arritmias Cardíacas/imunologia , Arritmias Cardíacas/fisiopatologia , Pressão Arterial/efeitos dos fármacos , Aterosclerose/genética , Aterosclerose/imunologia , Aterosclerose/patologia , Cardiomegalia/imunologia , Cardiomegalia/fisiopatologia , Modelos Animais de Doenças , Hipertensão/induzido quimicamente , Hipertensão/imunologia , Hipertensão/fisiopatologia , Masculino , Camundongos Knockout para ApoE , Placa Aterosclerótica , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia
8.
Chemistry ; 26(55): 12549-12552, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32757334

RESUMO

Mechanochemical synthesis of CsPbI3 , as a model system for ABX3 halides, was studied. Water was shown to strongly promote the kinetics of formation of CsPbI3 from the CsI+PbI2 mixture through increased mobility of the constituting ionic species. Since many binary and ternary halides are hygroscopic, it was concluded that the presence of small, uncontrollable and unintentional additions of water should often occur in both precursor mixtures and synthesized complex halides boosting the kinetics of formation of many, if not all, ternary organic-inorganic hybrid halides such as, for example, MAPbX3 (X=Cl, Br, I). In addition, trace amounts of water should influence the transport characteristics of complex halides. Thus, the presence of water explains, at least partially, the huge scatter in both the reported mechanochemical reaction times necessary for obtaining single-phase APbX3 perovskite halides and the activation energies of ionic diffusion in APbX3 .

9.
Inorg Chem ; 57(19): 12409-12416, 2018 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-30216058

RESUMO

The disordered La0.5Ba0.5CoO3-δ ↔ ordered LaBaCo2O6-δ transition was studied in detail using several complementary in situ (X-ray diffraction, thermogravimetry, and coulometric titration) and ex situ (transmission electron microscopy) techniques. This transition was found to proceed through the formation of complex domain textured intermediate products. They were shown to have strong affinity to oxygen and exhibit its fast absorption from ambient atmosphere (oxygen partial pressure ( pO2) 0.21 atm) at a temperature as low as 70 °C. The thermodynamic stability limits of the cubic and double perovskites were determined by coulometric titration. The stability diagram of the LaBaCo2O6-δ - La0.5Ba0.5CoO3-δ system was plotted as a result. Oxygen nonstoichiometry of the thermodynamically stable cubic perovskite La0.5Ba0.5CoO3-δ was measured as a function of pO2 in the temperature range between 1000 and 1100 °C using a coulometric titration technique.

11.
STAR Protoc ; 5(1): 102845, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38294910

RESUMO

The isolated perfused kidney is a classic ex vivo preparation for studying renal physiology in general and vascular function. Here, we present a protocol for assessing myogenic tone in isolated mouse kidneys as well as vasodilatory and vasoconstrictive responses, expressed as perfusion pressure. We describe steps for pre-operative preparation, kidney and renal artery isolation, and connection of renal artery with glass cannula. We then detail how to measure pressure changes in perfused kidneys and the myogenic tone. For complete details on the use and execution of this protocol, please refer to Cui et al.1.


Assuntos
Rim , Vasoconstrição , Camundongos , Animais , Pressão Sanguínea/fisiologia , Perfusão
12.
Hypertension ; 81(3): 561-571, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38354270

RESUMO

BACKGROUND: Small arteries exhibit resting tone, a partially contracted state that maintains arterial blood pressure. In arterial smooth muscle cells, potassium channels control contraction and relaxation. Perivascular adipose tissue (PVAT) has been shown to exert anticontractile effects on the blood vessels. However, the mechanisms by which PVAT signals small arteries, and their relevance remain largely unknown. We aimed to uncover key molecular components in adipose-vascular coupling. METHODS: A wide spectrum of genetic mouse models targeting Kcnq3, Kcnq4, and Kcnq5 genes (Kcnq3-/-, Kcnq4-/-, Kcnq5-/-, Kcnq5dn/dn, Kcnq4-/-/Kcnq5dn/dn, and Kcnq4-/-/Kcnq5-/-), telemetry blood pressure measurements, targeted lipidomics, RNA-Seq profiling, wire-myography, patch-clamp, and sharp-electrode membrane potential measurements was used. RESULTS: We show that PVAT causes smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels to hyperpolarize the membrane potential. This effect relaxes small arteries and regulates blood pressure. Oxygenation of polyunsaturated fats generates oxylipins, a superclass of lipid mediators. We identified numerous oxylipins released by PVAT, which potentiate vasodilatory action in small arteries by opening smooth muscle cell KV7.5 family of voltage-gated potassium (K+) channels. CONCLUSIONS: Our results reveal a key molecular function of the KV7.5 family of voltage-gated potassium (K+) channels in the adipose-vascular coupling, translating PVAT signals, particularly oxylipins, to the central physiological function of vasoregulation. This novel pathway opens new therapeutic perspectives.


Assuntos
Oxilipinas , Vasodilatação , Animais , Camundongos , Tecido Adiposo , Canais de Potássio KCNQ/genética , Canais de Potássio KCNQ/metabolismo , Oxilipinas/metabolismo , Potássio/metabolismo
13.
Cardiovasc Res ; 119(6): 1441-1452, 2023 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35904261

RESUMO

AIMS: Hypertension (HTN) can lead to heart and kidney damage. The gut microbiota has been linked to HTN, although it is difficult to estimate its significance due to the variety of other features known to influence HTN. In the present study, we used germ-free (GF) and colonized (COL) littermate mice to quantify the impact of microbial colonization on organ damage in HTN. METHODS AND RESULTS: 4-week-old male GF C57BL/6J littermates were randomized to remain GF or receive microbial colonization. HTN was induced by subcutaneous infusion with angiotensin (Ang) II (1.44 mg/kg/day) and 1% NaCl in the drinking water; sham-treated mice served as control. Renal damage was exacerbated in GF mice, whereas cardiac damage was more comparable between COL and GF, suggesting that the kidney is more sensitive to microbial influence. Multivariate analysis revealed a larger effect of HTN in GF mice. Serum metabolomics demonstrated that the colonization status influences circulating metabolites relevant to HTN. Importantly, GF mice were deficient in anti-inflammatory faecal short-chain fatty acids (SCFA). Flow cytometry showed that the microbiome has an impact on the induction of anti-hypertensive myeloid-derived suppressor cells and pro-inflammatory Th17 cells in HTN. In vitro inducibility of Th17 cells was significantly higher for cells isolated from GF than conventionally raised mice. CONCLUSION: The microbial colonization status of mice had potent effects on their phenotypic response to a hypertensive stimulus, and the kidney is a highly microbiota-susceptible target organ in HTN. The magnitude of the pathogenic response in GF mice underscores the role of the microbiome in mediating inflammation in HTN.


Assuntos
Microbioma Gastrointestinal , Hipertensão , Microbiota , Animais , Masculino , Camundongos , Inflamação , Camundongos Endogâmicos C57BL
14.
Materials (Basel) ; 15(21)2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36363267

RESUMO

Hybrid organic-inorganic perovskite halides, and, in particular, their mixed halide solid solutions, belong to a broad class of materials which appear promising for a wide range of potential applications in various optoelectronic devices. However, these materials are notorious for their stability issues, including their sensitivity to atmospheric oxygen and moisture as well as phase separation under illumination. The thermodynamic properties, such as enthalpy, entropy, and Gibbs free energy of mixing, of perovskite halide solid solutions are strongly required to shed some light on their stability. Herein, we report the results of an experimental thermochemical study of the CH3NH3Pb(Cl1-xBrx)3 mixed halides by solution calorimetry. Combining these results with molecular dynamics simulation revealed the complex and irregular shape of the compositional dependence of the mixing enthalpy to be the result of a complex interplay between the local lattice strain, hydrogen bonds, and energetics of these solid solutions.

15.
Membranes (Basel) ; 13(1)2022 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-36676817

RESUMO

Differential scanning calorimetry studies of the complex oxide YBaCo2O6-δ (YBC), combined with the literature data, allowed outlining the phase behavior of YBC depending on the oxygen content and temperature between 298 K and 773 K. The oxygen nonstoichiometry of single-phase tetragonal YBC was measured at different temperatures and oxygen partial pressures by both thermogravimetric and flow reactor methods. The defect structure of YBC was analyzed. As a result, the thermodynamic functions (∆Hi○, ∆Si○) of the defect reactions in YBC were determined. Experimental data on the oxygen content and those calculated based on the theoretical model were shown to be in good agreement. Standard enthalpies of formation at 298.15 K (∆Hf○) were obtained for YBC depending on its oxygen content using solution calorimetry. It was found that ∆Hf○ = f(6-δ) function is linear in the range of (6-δ) from 5.018 to 5.406 and that its slope is close to the value of the enthalpy of the quasichemical reaction describing oxygen exchange between the oxide and ambient atmosphere, which confirms the reliability of the suggested defect structure model.

16.
Membranes (Basel) ; 12(12)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36557108

RESUMO

Mixed conducting cobaltites PrBaCo2-xFexO6-δ (x = 0-0.6) with a double perovskite structure are promising materials for ceramic semi-permeable membranes for oxygen separation and purification due to their fast oxygen exchange and diffusion capability. Here, we report the results of the detailed study of an interplay between the defect chemistry, oxygen nonstoichiometry and oxygen transport in these materials as a function of iron doping. We show that doping leads to a systematic variation of both the thermodynamics of defect formation reactions and oxygen transport properties. Thus, iron doping can be used to optimize the performance of mixed conducting oxygen-permeable double perovskite membrane materials.

17.
Sci Rep ; 12(1): 3038, 2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35194063

RESUMO

Transient receptor potential channel subfamily C, member 6 (TRPC6), a non-selective cation channel that controls influx of Ca2+ and other monovalent cations into cells, is widely expressed in the kidney. TRPC6 gene variations have been linked to chronic kidney disease but its role in acute kidney injury (AKI) is unknown. Here we aimed to investigate the putative role of TRPC6 channels in AKI. We used Trpc6-/- mice and pharmacological blockade (SH045 and BI-749327), to evaluate short-term AKI outcomes. Here, we demonstrate that neither Trpc6 deficiency nor pharmacological inhibition of TRPC6 influences the short-term outcomes of AKI. Serum markers, renal expression of epithelial damage markers, tubular injury, and renal inflammatory response assessed by the histological analysis were similar in wild-type mice compared to Trpc6-/- mice as well as in vehicle-treated versus SH045- or BI-749327-treated mice. In addition, we also found no effect of TRPC6 modulation on renal arterial myogenic tone by using blockers to perfuse isolated kidneys. Therefore, we conclude that TRPC6 does not play a role in the acute phase of AKI. Our results may have clinical implications for safety and health of humans with TRPC6 gene variations, with respect to mutated TRPC6 channels in the response of the kidney to acute ischemic stimuli.


Assuntos
Injúria Renal Aguda/genética , Variação Genética , Isquemia/genética , Rim/irrigação sanguínea , Resultados Negativos , Canal de Cátion TRPC6/genética , Canal de Cátion TRPC6/fisiologia , APACHE , Injúria Renal Aguda/patologia , Animais , Cálcio/metabolismo , Isquemia/patologia , Rim/metabolismo , Camundongos Transgênicos
18.
Front Physiol ; 12: 749709, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34899382

RESUMO

Aging is an independent risk factor for hypertension, cardiovascular morbidity, and mortality. However, detailed mechanisms linking aging to cardiovascular disease are unclear. We studied the aging effects on the role of perivascular adipose tissue and downstream vasoconstriction targets, voltage-dependent KV7 channels, and their pharmacological modulators (flupirtine, retigabine, QO58, and QO58-lysine) in a murine model. We assessed vascular function of young and old mesenteric arteries in vitro using wire myography and membrane potential measurements with sharp electrodes. We also performed bulk RNA sequencing and quantitative reverse transcription-polymerase chain reaction tests in mesenteric arteries and perivascular adipose tissue to elucidate molecular underpinnings of age-related phenotypes. Results revealed impaired perivascular adipose tissue-mediated control of vascular tone particularly via KV7.3-5 channels with increased age through metabolic and inflammatory processes and release of perivascular adipose tissue-derived relaxation factors. Moreover, QO58 was identified as novel pharmacological vasodilator to activate XE991-sensitive KCNQ channels in old mesenteric arteries. Our data suggest that targeting inflammation and metabolism in perivascular adipose tissue could represent novel approaches to restore vascular function during aging. Furthermore, KV7.3-5 channels represent a promising target in cardiovascular aging.

19.
Pain Res Manag ; 15(4): 224-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20808967

RESUMO

PURPOSE: The present study investigated whether the conceptualization of hip and knee osteoarthritis pain implicit in the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and Medical Outcomes Study Short-Form 36 (SF-36) scales is complete, or whether the addition of another scale, such as the Short-Form McGill Pain Questionnaire (MPQ-SF), provides a more complete characterization. Furthermore, the impact that mental health symptoms and catastrophizing had on these scales was investigated. METHODS: Before hip and knee arthroplasty, 200 patients completed surveys of demographic data, the WOMAC pain scale, the MPQ-SF, the SF-36 Bodily Pain scale, the Pain Catastrophizing Scale and the Hospital Anxiety and Depression Scale. Correlations between scales were calculated and linear regression modelling was used to determine the impact of mental health and catastrophizing on these three pain measures. RESULTS: A strong correlation between the WOMAC and SF-36 pain scales (r=-0.70) was found; however, both correlated only moderately with the MPQ-SF (r=0.36 and r=-0.36, respectively). Linear regression modelling showed that the Pain Catastrophizing Scale significantly predicted a greater score on all three pain scales (P<0.05). CONCLUSIONS: The addition of the MPQ-SF appears to add to a more complete quantification of the pain experience in hip and knee osteoarthritis.


Assuntos
Osteoartrite do Quadril/complicações , Osteoartrite do Joelho/complicações , Avaliação de Resultados em Cuidados de Saúde/métodos , Dor , Idoso , Feminino , Inquéritos Epidemiológicos , Humanos , Masculino , Pessoa de Meia-Idade , Dor/diagnóstico , Dor/etiologia , Dor/psicologia , Medição da Dor/métodos , Escalas de Graduação Psiquiátrica , Estudos Retrospectivos , Índice de Gravidade de Doença , Estatística como Assunto
20.
Can J Surg ; 53(3): 151-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20507785

RESUMO

BACKGROUND: The best measure of body habitus as a risk factor for chronic disease is not well defined. Our intent was to examine the relation between waist-hip ratio (WHR) and body mass index (BMI) as a measurement of body habitus in patients with end-stage knee osteoarthritis (OA). METHODS: We reviewed the data of 200 consecutive patients in our registry undergoing knee replacement surgery for demographic data of age, sex, BMI and WHR. We performed a stratified analysis by sex and calculated the risk ratios (RRs) to describe the risk of being classified as obese by WHR for those considered obese by the BMI criteria. RESULTS: A similar percentage of male and female patients were classified as obese by the BMI criteria (38% v. 42%, respectively). Men were classified as obese more often than women by WHR (92% v. 82%). The RR of being obese as determined by WHR if classified as obese by the BMI criteria was 1.04 (95% confidence interval [CI]0.91-1.18) for men and 1.23 (95% CI 1.03-1.46) for women. CONCLUSION: Among patients with knee OA, the overlap between BMI and WHR is greater in women than men. This difference has implications for defining the prevalence of metabolic syndrome in this population.


Assuntos
Índice de Massa Corporal , Obesidade/complicações , Osteoartrite do Joelho/etiologia , Relação Cintura-Quadril , Adulto , Idoso , Artroplastia do Joelho , Feminino , Humanos , Masculino , Síndrome Metabólica/etiologia , Pessoa de Meia-Idade , Osteoartrite do Joelho/cirurgia , Sistema de Registros , Fatores de Risco
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