Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 103
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Appl Opt ; 62(18): 5023-5027, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37707280

RESUMO

In this paper, the graphdiyne (GDY)-polymethyl methacrylate (PMMA) films are prepared by a spin-coating method. The PMMA films have the function of isolating GDY from air and protecting the GDY from mechanical damage. The nonlinear optical properties of GDY-PMMA films are probed experimentally. The nonlinear optical responses of GDY-PMMA films with a modulation depth of ∼4.94% and saturated magnetization of ∼0.3M W/c m 2 are proved. When the GDY-PMMA films are applied to an erbium-doped hybrid passively mode-locked fiber laser (saturable absorber), the bound-state solitons, which are also called soliton molecules, can be obtained. The soliton molecule has a time separation of 13.31 ps, and the spectral modulation period of 0.58 nm. Along with the pump power increase, the separation of bound-state pulses becomes larger. When the pump power is fixed, stable bound solitons can be observed without any degeneration for more than 4.5 h. It is demonstrated that GDY-PMMA films have excellent nonlinear optical performance in a near-infrared regime, which we believe can be a novel type of photonics instrument and has a number of properties that are potentially promising in the ultrafast properties of laser.

2.
Heart Surg Forum ; 26(5): E628-E638, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37920089

RESUMO

OBJECTIVES: For a long time, the association of the false lumen status and the outcomes of patients suffering from aortic dissection has been unclear, so this review article aims to study whether the unobstructed of the false lumen is related to the outcome of patients suffering from aortic dissection. METHODS: We performed this systematic review and meta-analysis according to the Preferred Reporting Items for Systematic Reviews and Meta Analyzes Protocols (PRISMA) statement 2009 and registered with PROSPERO (CRD42022381869). We searched PubMed, the Cochrane library, Web of Science and Embase to collect potential studies. The Newcastle-Ottawa Scale was used to assess the quality of the included studies. The main outcome is long-term survival. Data included in the study were summarized using the risk ratio or mean difference and 95% confidence interval. RESULTS: There were 16 trials, 2829 patients in total, with a mean age of 62.1 years. Compared with completely thrombosed false lumen, patent group has better long-term survival (risk ratio (RR), 0.88; 95% CI, 0.79 to 0.97; p = 0.01; I2 = 58%) and smaller yearly aortic growth rate (mean difference (MD), 1.03; 95% CI, 0.23 to 1.82; p = 0.01; I2 = 98%). In addition, patients with a patent false lumen had a lower risk of aortic event (RR, 0.81; 95% CI, 0.68 to 0.97; p = 0.02; I2 = 37%), but higher risk of aortic rupture (RR, 7.02; 95% CI, 2.55 to 19.3; p = 0.0002; I2 = 0) and hospital death (RR, 2.72; 95% CI, 1.45 to 5.08; p = 0.002; I2 = 0). CONCLUSION: Completely thrombosed of the false lumen is more beneficial to the long-term survival of patients with aortic dissection. And the risk of aortic rupture and hospital death in patients with patent false lumen is 7 times and 3 times that of patients with complete thrombosed false lumen. It is expected to provide individualized medical care for different types of patients according to different false lumen status to minimize death and related complications.


Assuntos
Aneurisma da Aorta Torácica , Dissecção Aórtica , Ruptura Aórtica , Procedimentos Endovasculares , Trombose , Humanos , Pessoa de Meia-Idade , Dissecção Aórtica/diagnóstico , Dissecção Aórtica/cirurgia , Ruptura Aórtica/etiologia , Ruptura Aórtica/prevenção & controle , Estudos Retrospectivos , Trombose/complicações , Resultado do Tratamento
3.
Am J Physiol Renal Physiol ; 322(5): F498-F511, 2022 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-35285274

RESUMO

In independent studies, our laboratory has shown the importance of the degenerin proteins ß-epithelial Na+ channel (ßENaC) and acid-sensing ion channel 2 (ASIC2) in pressure-induced constriction (PIC) in renal interlobar arteries. Most, but not all, of the PIC response is abolished in mice lacking normal levels of ßENaC or in ASIC2-null mice, indicating that the functions of ßENaC and ASIC2 cannot fully compensate for the loss of the other. Degenerin proteins are known to associate and form heteromeric channels in expression systems, but whether they interact biochemically and functionally in vascular smooth muscle cells is unknown. We hypothesized that ßENaC and ASIC2 interact to mediate PIC responses in renal vessels. To address this possibility, we 1) used biochemical approaches to show that ßENaC associates into high-molecular-weight complexes and immunoprecipitants with ASIC2 in vascular smooth muscle cells and then 2) examined PIC in renal afferent arterioles in mice lacking normal levels of ßENaC (ßENaCm/m) or/and ASIC2 (ASIC2-/-) using the isolated afferent arteriole-attached glomerulus preparation. We found that the sensitivity of the PIC response (slope of the relationship between intraluminal pressure and percent myogenic tone) decreased to 26%, 27%, and -8% of wild-type controls in ASIC2-/-, ßENaCm/m, and ASIC2-/-/ßENaCm/m groups, respectively, suggesting that the PIC response was totally abolished in mice deficient in both ASIC2 and ßENaC. Surprisingly, we found that resting internal diameters were 20-30% lower (60 mmHg, Ca2+ free) in ASIC2-/-/ßENaCm/m (11.3 ± 0.5 µm) mice compared with control (14.4 ± 0.6 µm, P = 0.0007, independent two-tailed t test) or singly modified (15.7 ± 1.0 to 16.3 ± 1.1 µm) mice, suggesting compensatory vasoconstriction or remodeling. We then examined mean arterial blood pressure (MAP) using radiotelemetry and glomerular injury using histological examination of renal sections. We found that 24-h MAP was mildly elevated (+8 mmHg) in ASIC2-/-/ßENaCm/m mice versus wild-type controls and the glomerular injury score was modestly increased by 38%. These findings demonstrate that myogenic constriction in afferent arterioles is dependent on normal expression of ßENaC and ASIC2 and that mice lacking normal levels of ASIC2 and ßENaC have mild renal injury and increased MAP.NEW & NOTEWORTHY Transmission of systemic blood pressure to delicate renal microvessels is a primary determinant of vascular injury in chronic kidney disease progression to end-stage renal disease. Here, we identified two degenerin family members, with an evolutionary link to mechanosensing, that interact biochemically and functionally to regulate systemic blood pressure and renal injury. Thus, degenerin proteins may serve as a target for the development of therapies to prevent or delay renal disease progression.


Assuntos
Rim , Músculo Liso Vascular , Animais , Arteríolas , Constrição , Camundongos , Músculo Liso Vascular/metabolismo , Vasoconstrição
4.
Kidney Int ; 101(3): 541-550, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34843754

RESUMO

An increase of glomerular filtration rate (GFR) is a common observation in early diabetes and is considered a key risk factor for subsequent kidney injury. However, the mechanisms underlying diabetic hyperfiltration have not been fully clarified. Here, we tested the hypothesis that macula densa neuronal nitric oxide synthase (NOS1) is upregulated via sodium glucose cotransporter type 1 (SGLT1) in diabetes, which then inhibits tubuloglomerular feedback (TGF) promoting glomerular hyperfiltration. Therefore, we examined changes in cortical NOS1 expression and phosphorylation, nitric oxide production in the macula densa, TGF response, and GFR during the early stage of insulin-deficient (Akita) diabetes in wild-type and macula densa-specific NOS1 knockout mice. A set of sophisticated techniques including microperfusion of juxtaglomerular apparatus in vitro, micropuncture of kidney tubules in vivo, and clearance kinetics of plasma fluorescent-sinistrin were employed. Complementary studies tested the role of SGLT1 in SGLT1 knockout mice and explored NOS1 expression and phosphorylation in kidney biopsies of cadaveric donors. Diabetic mice had upregulated macula densa NOS1, inhibited TGF and elevated GFR. Macula densa-selective NOS1 knockout attenuated the diabetes-induced TGF inhibition and GFR elevation. Additionally, deletion of SGLT1 prevented the upregulation of macula densa NOS1 and attenuated inhibition of TGF in diabetic mice. Furthermore, the expression and phosphorylation levels of NOS1 were increased in cadaveric kidneys of diabetics and positively correlated with blood glucose as well as estimated GFR in the donors. Thus, our findings demonstrate that the macula densa SGLT1-NOS1-TGF pathway plays a crucial role in the control of GFR in diabetes.


Assuntos
Diabetes Mellitus Experimental , Transportador 1 de Glucose-Sódio/metabolismo , Animais , Diabetes Mellitus Experimental/metabolismo , Retroalimentação , Taxa de Filtração Glomerular/fisiologia , Glomérulos Renais/metabolismo , Túbulos Renais/metabolismo , Camundongos , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo I/metabolismo
5.
J Am Soc Nephrol ; 32(10): 2485-2500, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34127535

RESUMO

BACKGROUND: Regulation of renal hemodynamics and BP via tubuloglomerular feedback (TGF) may be an important adaptive mechanism during pregnancy. Because the ß-splice variant of nitric oxide synthase 1 (NOS1ß) in the macula densa is a primary modulator of TGF, we evaluated its role in normal pregnancy and gestational hypertension in a mouse model. We hypothesized that pregnancy upregulates NOS1ß in the macula densa, thus blunting TGF, allowing the GFR to increase and BP to decrease. METHODS: We used sophisticated techniques, including microperfusion of juxtaglomerular apparatus in vitro, micropuncture of renal tubules in vivo, clearance kinetics of plasma FITC-sinistrin, and radiotelemetry BP monitoring, to determine the effects of normal pregnancy or reduced uterine perfusion pressure (RUPP) on macula densa NOS1ß/NO levels, TGF responsiveness, GFR, and BP in wild-type and macula densa-specific NOS1 knockout (MD-NOS1KO) mice. RESULTS: Macula densa NOS1ß was upregulated during pregnancy, resulting in blunted TGF, increased GFR, and decreased BP. These pregnancy-induced changes in TGF and GFR were largely diminished, with a significant rise in BP, in MD-NOS1KO mice. In addition, RUPP resulted in a downregulation in macula densa NOS1ß, enhanced TGF, decreased GFR, and hypertension. The superimposition of RUPP into MD-NOS1KO mice only caused a modest further alteration in TGF and its associated changes in GFR and BP. Finally, in African green monkeys, renal cortical NOS1ß expression increased in normotensive pregnancies, but decreased in spontaneous gestational hypertensive pregnancies. CONCLUSIONS: Macula densa NOS1ß plays a critical role in the control of renal hemodynamics and BP during pregnancy.


Assuntos
Pressão Arterial , Hipertensão Induzida pela Gravidez/fisiopatologia , Glomérulos Renais/fisiopatologia , Túbulos Renais Distais/fisiopatologia , Óxido Nítrico Sintase Tipo I/metabolismo , Animais , Chlorocebus aethiops , Retroalimentação Fisiológica , Feminino , Taxa de Filtração Glomerular , Hipertensão Induzida pela Gravidez/metabolismo , Hipertensão Induzida pela Gravidez/patologia , Isoenzimas , Túbulos Renais Distais/metabolismo , Camundongos , Camundongos Knockout , Óxido Nítrico Sintase Tipo I/genética , Gravidez , Circulação Renal , Regulação para Cima , Útero/irrigação sanguínea
6.
Microcirculation ; 28(3): e12661, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33025626

RESUMO

Kidneys are highly vascular organs that despite their relatively small size receive 20% of the cardiac output. The highly intricate, delicately organized structure of renal microcirculation is essential to enable renal function and glomerular filtration rate through the local modulation of renal blood flow and intraglomerular pressure. Not surprisingly, the dysregulation of blood flow within the microvessels (abnormal vasoreactivity), fibrosis driven by disordered vascular-renal cross talk, or the loss of renal microvasculature (rarefaction) is associated with kidney disease. In addition, kidney disease can cause microcirculatory dysfunction in distant organs such as the heart and brain, mediated by mechanisms that remain to be elucidated. The objective of this review is to highlight the role of renal microvasculature in kidney disease. The overview will outline the impetus to study renal microvasculature, the bidirectional relationship between kidney disease and microvascular dysfunction, the key pathways driving microvascular diseases such as vasoreactivity, the cell dynamics coordinating fibrosis, and vessel rarefaction. Finally, we will also briefly highlight new therapies targeting the renal microvasculature to improve renal function.


Assuntos
Nefropatias , Microcirculação , Fibrose , Humanos , Rim/patologia , Nefropatias/patologia , Microvasos/patologia
7.
Zhong Nan Da Xue Xue Bao Yi Xue Ban ; 46(2): 217-220, 2021 Feb 28.
Artigo em Inglês, Zh | MEDLINE | ID: mdl-33678662

RESUMO

Type A aortic dissection (AD) is a critical and severe disease with high mortality. The Sun's operation is a standard surgical method for this kind of disease at present. For the procedure, an elephant trunk stent is inserted into the true lumen of the descending aorta and the aortic arch is replaced. A patient was admitted to the First Hospital of Lanzhou University due to sudden chest and back pain for 6 days. Computed tomography angiography (CTA) showed type A AD. Ascending aorta replacement, Sun's operation, and ascending aorta to right femoral artery bypass grafting were performed. After surgery, the patient's condition was worsened. The digital subtraction angiography (DSA) showed the elephant trunk stent was inserted into the false lumen of AD, leading to the occlusion of the large blood vessel at the distal part of the abdominal aorta and below. Although we performed intima puncture and endovascular aortic repair, the patient was still dead.


Assuntos
Dissecção Aórtica , Implante de Prótese Vascular , Dissecção Aórtica/diagnóstico por imagem , Dissecção Aórtica/cirurgia , Aorta Abdominal , Aorta Torácica/cirurgia , Implante de Prótese Vascular/efeitos adversos , Humanos , Stents/efeitos adversos , Resultado do Tratamento
8.
Am J Physiol Renal Physiol ; 319(5): F908-F919, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-33044868

RESUMO

Females are protected against the development of angiotensin II (ANG II)-induced hypertension compared with males, but the mechanisms have not been completely elucidated. In the present study, we hypothesized that the effect of ANG II on the macula densa nitric oxide (NO) synthase 1ß (NOS1ß)-mediated tubuloglomerular feedback (TGF) mechanism is different between males and females, thereby contributing to the sexual dimorphism of ANG II-induced hypertension. We used microperfusion, micropuncture, clearance of FITC-inulin, and radio telemetry to examine the sex differences in the changes of macula densa NOS1ß expression and activity, TGF response, natriuresis, and blood pressure (BP) after a 2-wk ANG II infusion in wild-type and macula densa-specific NOS1 knockout mice. In wild-type mice, ANG II induced higher expression of macula densa NOS1ß, greater NO generation by the macula densa, and a lower TGF response in vitro and in vivo in females than in males; the increases of glomerular filtration rate, urine flow rate, and Na+ excretion in response to an acute volume expansion were significantly greater and the BP responses to ANG II were significantly less in females than in males. In contrast, these sex differences in the effects of ANG II on TGF, natriuretic response, and BP were largely diminished in knockout mice. In addition, tissue culture of human kidney biopsies (renal cortex) with ANG II resulted in a greater increase in NOS1ß expression in females than in males. In conclusion, macula densa NOS1ß-mediated TGF is a novel and important mechanism for the sex differences in ANG II-induced hypertension.


Assuntos
Hipertensão/metabolismo , Túbulos Renais/efeitos dos fármacos , Óxido Nítrico Sintase/metabolismo , Caracteres Sexuais , Angiotensina II/farmacologia , Animais , Retroalimentação , Feminino , Taxa de Filtração Glomerular/efeitos dos fármacos , Hipertensão/induzido quimicamente , Córtex Renal/metabolismo , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/metabolismo , Túbulos Renais/metabolismo , Masculino , Camundongos Knockout , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo
9.
Am J Physiol Renal Physiol ; 319(2): F304-F311, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32567350

RESUMO

Acute kidney injury (AKI) significantly increases the risk of development of chronic kidney disease (CKD). Recently, our laboratory generated a mouse model with the typical phenotypes of AKI to CKD transition in the unilateral kidney. However, AKI, CKD, and even the transition from AKI to CKD usually occur bilaterally rather than unilaterally in patients. Therefore, in the present study, we further modified the strategy and developed a new model of CKD transitioned from bilateral ischemia-reperfusion injury (IRI) in C57BL/6 mice. In this new model, unilateral severe IRI was performed in one kidney while the contralateral kidney was kept intact to maintain animal survival; then, following 14 days of recovery, when the renal function of the injured kidney restored above the survival threshold, the contralateral intact kidney was subjected to a similar IRI. Animals of these two-stage bilateral IRI models with pedicle clamping of 21 and 24 min at a body temperature of 37°C exhibited incomplete recovery from AKI and subsequent development of CKD with characteristics of progressive decline in glomerular filtration rate, increases in plasma creatinine, worsening of proteinuria, and deleterious histopathological changes, including interstitial fibrosis and glomerulosclerosis, in both kidneys. In conclusion, a new bilateral AKI to CKD transition animal model with a typical phenotype of CKD was generated in C57BL/6 mice.


Assuntos
Injúria Renal Aguda/complicações , Injúria Renal Aguda/patologia , Insuficiência Renal Crônica/patologia , Traumatismo por Reperfusão/patologia , Animais , Modelos Animais de Doenças , Fibrose/metabolismo , Taxa de Filtração Glomerular/fisiologia , Rim/patologia , Masculino , Camundongos Endogâmicos C57BL , Proteinúria/fisiopatologia , Traumatismo por Reperfusão/complicações
10.
Langmuir ; 36(1): 3-8, 2020 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-31800254

RESUMO

Bismuthene, as a new two-dimensional material made up of diazo metal elements, has drawn massive attention for its unique electronic, mechanical, quantum, and nonlinear optical properties. In recent years, researchers have increasingly turned their attention to the ultrafast photonics fields based on bismuthene. However, the internal ultrashort pulse dynamics has seldom been explored yet. In this work, the nonlinear optical properties of bismuthene nanosheets have been studied and applied in a passively mode-locked fiber laser. The saturation intensity and modulation depth of a saturable absorber (SA) device are about 2.4 MW/cm2 and 1%, respectively. Thanks to the narrow band gap of bismuthene and tapered fiber structure, a special kind of noise-like multipulses has been obtained. The evolution of the pulsed laser is also studied. This proposed pulsed fiber laser based on a bismuthene SA device is well suitable for some applications such as material processing, optical logics, and so forth.

11.
J Am Soc Nephrol ; 30(4): 578-593, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30867247

RESUMO

BACKGROUND: Glomerular hyperfiltration is common in early diabetes and is considered a risk factor for later diabetic nephropathy. We propose that sodium-glucose cotransporter 1 (SGLT1) senses increases in luminal glucose at the macula densa, enhancing generation of neuronal nitric oxide synthase 1 (NOS1)-dependent nitric oxide (NO) in the macula densa and blunting the tubuloglomerular feedback (TGF) response, thereby promoting the rise in GFR. METHODS: We used microperfusion, micropuncture, and renal clearance of FITC-inulin to examine the effects of tubular glucose on NO generation at the macula densa, TGF, and GFR in wild-type and macula densa-specific NOS1 knockout mice. RESULTS: Acute intravenous injection of glucose induced hyperglycemia and glucosuria with increased GFR in mice. We found that tubular glucose blunts the TGF response in vivo and in vitro and stimulates NO generation at the macula densa. We also showed that SGLT1 is expressed at the macula densa; in the presence of tubular glucose, SGLT1 inhibits TGF and NO generation, but this action is blocked when the SGLT1 inhibitor KGA-2727 is present. In addition, we demonstrated that glucose increases NOS1 expression and NOS1 phosphorylation at Ser1417 in mouse renal cortex and cultured human kidney tissue. In macula densa-specific NOS1 knockout mice, glucose had no effect on NO generation, TGF, and GFR. CONCLUSIONS: We identified a novel mechanism of acute hyperglycemia-induced hyperfiltration wherein increases in luminal glucose at the macula densa upregulate the expression and activity of NOS1 via SGLT1, blunting the TGF response and promoting glomerular hyperfiltration.


Assuntos
Glucose/metabolismo , Hiperglicemia/fisiopatologia , Glomérulos Renais/fisiopatologia , Túbulos Renais Distais/metabolismo , Óxido Nítrico Sintase Tipo I/metabolismo , Transportador 1 de Glucose-Sódio/metabolismo , Animais , Retroalimentação Fisiológica , Taxa de Filtração Glomerular , Glucosídeos/farmacologia , Humanos , Inulina/metabolismo , Glomérulos Renais/metabolismo , Túbulos Renais Distais/fisiopatologia , Masculino , Camundongos , Camundongos Knockout , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo I/genética , Fosforilação , Pirazóis/farmacologia , Transdução de Sinais , Transportador 1 de Glucose-Sódio/antagonistas & inibidores
12.
Mikrochim Acta ; 187(7): 373, 2020 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-32504133

RESUMO

A new series of 9-plex chemical isotope-labeling reagents, levofloxacin-based mass tags (LMTs) named as LMT359, 360, 361, 362, 363, 373, 375, 376, and 378, was firstly designed and synthesized for the high-throughput labeling of globotriaosylsphingosine (lyso-Gb3), a disease biomarker of Fabry disease. Creatively based on derivatization strategy-dummy template technique, dummy magnetic molecularly imprinted polymers (DMMIPs) were designed and prepared using LMT387-labeled lyso-Gb3 as a dummy template. The novel DMMIP material was used as sorbents for magnetic dispersive solid-phase extraction of 9-plexed LMT derivatives of lyso-Gb3 from equally mixed derivatization solutions. The enriched 8-plexed lyso-Gb3 derivatives from 8 real samples were quantified by ultra-high-performance liquid chromatography tandem mass spectrometry in a single run using simultaneously extracted LMT359-labeled standard lyso-Gb3 as internal standards. DMMIPs were characterized by using the transmission electron microscope (TEM), Fourier transform infrared, X-ray photoelectron spectroscopy, and some other characterization techniques. TEM micrograph showed that the prepared DMMIPs had an apparent imprinting layer. Triple-recognition abilities of DMMIPs towards LMT-lyso-Gb3 mainly rely on the hydrogen bonding, electrostatic attraction, hydrophobic interaction, and boronate affinity. The imprinting factor of DMMIPs towards LMT-lyso-Gb3 was 5.1. This method shows the advantages of high selectivity (triple recognition), high sensitivity, high accuracy (recovery 93.5-108.8%), and high throughput (8 samples in a single run). The proposed method was successfully applied to the determination of lyso-Gb3 in plasma samples with spiked recoveries in the range of 95.0-102.4%. This indicates that the method is promising in bioanalysis and medical testing of lyso-Gb3 in the future. Graphical abstract Synthesis of multiplexed derivatization reagents and its correlative molecularly imprinted polymers for magnetic extraction of globotriaosylsphingosine.

13.
Am J Physiol Renal Physiol ; 317(2): F286-F295, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31116604

RESUMO

Acute kidney injury (AKI) significantly increases the risk of development of chronic kidney disease (CKD), which is closely associated with the severity of AKI. However, the underlying mechanisms for the AKI to CKD transition remain unclear. Several animal models with AKI to CKD transition have been generated and widely used in research; however, none of them exhibit the typical changes in glomerular filtration rate or plasma creatinine, the hallmarks of CKD. In the present study, we developed a novel model with a typical phenotype of AKI to CKD transition in C57BL/6 mice. In this model, life-threatening ischemia-reperfusion injury was performed in one kidney, whereas the contralateral kidney was kept intact to maintain animal survival; then, after 2 wk of recovery, when the renal function of the injured kidney restored above the survival threshold, the contralateral intact kidney was removed. Animals of this two-stage unilateral ischemia-reperfusion injury model with pedicle clamping of 21 and 24 min exhibited an incomplete recovery from AKI and subsequent progression of CKD with characteristics of a progressive decline in glomerular filtration rate, increase in plasma creatinine, worsening of proteinuria, and deleterious histopathological changes, including interstitial fibrosis and glomerulosclerosis. In conclusion, a new model of the AKI to CKD transition was generated in C57BL/6 mice.


Assuntos
Injúria Renal Aguda/etiologia , Rim , Insuficiência Renal Crônica/etiologia , Traumatismo por Reperfusão/complicações , Injúria Renal Aguda/metabolismo , Injúria Renal Aguda/patologia , Injúria Renal Aguda/fisiopatologia , Animais , Biomarcadores/sangue , Constrição , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Fibrose , Taxa de Filtração Glomerular , Rim/metabolismo , Rim/fisiopatologia , Rim/ultraestrutura , Camundongos Endogâmicos C57BL , Nefrectomia , Tamanho do Órgão , Fenótipo , Proteinúria/etiologia , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/patologia , Insuficiência Renal Crônica/fisiopatologia , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Fatores de Tempo
14.
Am J Physiol Renal Physiol ; 317(3): F616-F622, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31291121

RESUMO

Transplanted kidneys usually experience several episodes of ischemia, including cold ischemia during allograft storage in preservation solution. However, previous studies focusing on cold renal ischemia were only carried out in vitro or ex vivo. In the present study, we developed and characterized an in vivo mouse model of renal ischemia-reperfusion injury (IRI) induced exclusively by cold ischemia. C57BL/6 mice underwent right kidney nephrectomy, and the left kidney was kept cool with circulating cold saline in a kidney cup, while body temperature was maintained at 37°C. We clamped the renal pedicle and flushed out the blood inside the kidney with cold saline via an opening on the renal vein. The severity of renal IRI was examined with different ischemic durations. We found that the mice with <2 h of cold ischemia exhibited no significant changes in renal function or histopathology; animals with 3 or 4 h of cold ischemia developed into mild to moderate acute kidney injury with characteristic features, including the elevation in plasma creatinine concentration and reduction in glomerular filtration rate and tubular necrosis, followed by a subsequent recovery. However, mice with 5 h of cold ischemia died in a few days with severe acute kidney injury. In summary, we generated a mouse model of renal IRI induced exclusively by cold ischemia, which mimics graft cold storage in preservation solution, and renal function can be evaluated in vivo.


Assuntos
Injúria Renal Aguda/etiologia , Isquemia Fria , Transplante de Rim , Rim/irrigação sanguínea , Traumatismo por Reperfusão/etiologia , Injúria Renal Aguda/sangue , Injúria Renal Aguda/patologia , Injúria Renal Aguda/fisiopatologia , Animais , Antígenos CD/metabolismo , Biomarcadores/sangue , Caderinas/metabolismo , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Taxa de Filtração Glomerular , Rim/metabolismo , Rim/patologia , Rim/fisiopatologia , Masculino , Camundongos Endogâmicos C57BL , Necrose , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/patologia , Traumatismo por Reperfusão/fisiopatologia , Fatores de Tempo
15.
Am J Physiol Renal Physiol ; 317(1): F207-F217, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31091127

RESUMO

Na+-glucose cotransporter (SGLT)1 mediates glucose reabsorption in late proximal tubules. SGLT1 also mediates macula densa (MD) sensing of an increase in luminal glucose, which increases nitric oxide (NO) synthase 1 (MD-NOS1)-mediated NO formation and potentially glomerular filtratrion rate (GFR). Here, the contribution of SGLT1 was tested by gene knockout (-/-) in type 1 diabetic Akita mice. A low-glucose diet was used to prevent intestinal malabsorption in Sglt1-/- mice and minimize the contribution of intestinal SGLT1. Hyperglycemia was modestly reduced in Sglt1-/- versus littermate wild-type Akita mice (480 vs. 550 mg/dl), associated with reduced diabetes-induced increases in GFR, kidney weight, glomerular size, and albuminuria. Blunted hyperfiltration was confirmed in streptozotocin-induced diabetic Sglt1-/- mice, associated with similar hyperglycemia versus wild-type mice (350 vs. 385 mg/dl). Absence of SGLT1 attenuated upregulation of MD-NOS1 protein expression in diabetic Akita mice and in response to SGLT2 inhibition in nondiabetic mice. During SGLT2 inhibition in Akita mice, Sglt1-/- mice had likewise reduced blood glucose (200 vs. 300 mg/dl), associated with lesser MD-NOS1 expression, GFR, kidney weight, glomerular size, and albuminuria. Absence of Sglt1 in Akita mice increased systolic blood pressure, associated with suppressed renal renin mRNA expression. This may reflect fluid retention due to blunted hyperfiltration. SGLT2 inhibition prevented the blood pressure increase in Sglt1-/- Akita mice, possibly due to additive glucosuric/diuretic effects. The data indicate that SGLT1 contributes to diabetic hyperfiltration and limits diabetic hypertension. Potential mechanisms include its role in glucose-driven upregulation of MD-NOS1 expression. This pathway may increase GFR to maintain volume balance when enhanced MD glucose delivery indicates upstream saturation of SGLTs and thus hyperreabsorption.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Tipo 1/enzimologia , Nefropatias Diabéticas/enzimologia , Taxa de Filtração Glomerular , Rim/enzimologia , Óxido Nítrico Sintase Tipo I/metabolismo , Transportador 1 de Glucose-Sódio/deficiência , Albuminúria/enzimologia , Albuminúria/genética , Albuminúria/fisiopatologia , Animais , Biomarcadores/sangue , Glicemia/efeitos dos fármacos , Pressão Sanguínea , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/sangue , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/fisiopatologia , Nefropatias Diabéticas/sangue , Nefropatias Diabéticas/tratamento farmacológico , Nefropatias Diabéticas/fisiopatologia , Taxa de Filtração Glomerular/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/fisiopatologia , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Camundongos Knockout , Óxido Nítrico Sintase Tipo I/genética , Reabsorção Renal , Renina/sangue , Renina/genética , Transdução de Sinais , Transportador 1 de Glucose-Sódio/genética , Transportador 2 de Glucose-Sódio , Inibidores do Transportador 2 de Sódio-Glicose/farmacologia , Regulação para Cima
16.
Eur J Clin Pharmacol ; 75(12): 1685-1693, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31444512

RESUMO

PURPOSE: Factors influencing responsiveness to warfarin at treatment onset time were not well identified in Chinese patients undergoing heart valve replacement. We sought to select the most relevant factors that associated with patient response to warfarin early after heart valve surgery. METHODS: In this observational study, 289 patients starting warfarin therapy early after heart valve replacement surgery were enrolled. CYP2C9 *1, *2, *3, and *5; VKORC1-1639 G>A, CYP4F2 V433M, and GGCX rs11676382 genotypes; clinical characteristics, response to therapy, and bleeding and thrombosis events were collected. The primary outcomes were the time to the first INR equal to or more than lower limit of therapeutic range and the warfarin dose requirements. Stepwise multiple linear regression was performed to develop a dosing algorithm to predict the warfarin dose requirements. RESULTS: The results of univariate analysis showed lone VKORC1-1639 G>A, CYP2C9 *1/*3, cefazolin, cefoperazone-sulbactam, increased BMI, Δhemoglobin, and white blood cell count could significantly affect patient responsiveness to warfarin in the initial period of anticoagulation. Multivariate analysis resulted in an equation: Accumulated warfarin doses (mg) = 17.068 VKORC1-1639 G>A - 4.261 hypertension + 0.593 BMI - 0.115 age - 4.852 CYP2C9 *1/*3 - 2.617 cefazolin - 4.902 cefoperazone-sulbactam - 4.537, which could explain 40.2% of the variability in warfarin dose needed to reach the first INR equal to or more than lower limit of therapeutic range. CONCLUSIONS: Both genetic and clinical factors contributed to anticoagulation effect of warfarin in the initial period of treatment. Our findings could provide a basis for the personalized management of warfarin use in the early stage of anticoagulation in northern Chinese patients.


Assuntos
Anticoagulantes/administração & dosagem , Carbono-Carbono Ligases/genética , Citocromo P-450 CYP2C9/genética , Família 4 do Citocromo P450/genética , Implante de Prótese de Valva Cardíaca/métodos , Vitamina K Epóxido Redutases/genética , Varfarina/administração & dosagem , Adulto , Coagulação Sanguínea/efeitos dos fármacos , Feminino , Implante de Prótese de Valva Cardíaca/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Trombose/etiologia , Trombose/prevenção & controle
17.
Am J Physiol Renal Physiol ; 314(3): F381-F387, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29141940

RESUMO

storage is the most prevalent method for graft preservation in kidney transplantation (KTX). The protective effects of various preservation solutions have been studied extensively in both clinical trials and experimental animal models. However, a paucity of studies have examined the effect of different preservation solutions on graft function in mouse KTX; in addition, the tolerance of the transplanted grafts to further insult has not been evaluated, which was the objective of the present study. We performed mouse KTX in three groups, with the donor kidneys preserved in different solutions for 60 min: saline, mouse serum, and University of Wisconsin (UW) solution. The graft functions were assessed by kidney injury markers and glomerular filtration rate (GFR). The grafts that were preserved in UW solution exhibited better functions, reflected by 50 and 70% lower plasma creatinine levels as well as 30 and 55% higher plasma creatinine levels in GFR than serum and saline groups, respectively, during the first week after transplants. To examine the graft function in response to additional insult, we induced ischemia-reperfusion injury (IRI) by clamping the renal pedicle for 18 min at 4 wk after KTX. We found that the grafts preserved in UW solution exhibited ~30 and 20% less injury assessed by kidney injury markers and histology than in other two preservation solutions. Taken together, our results demonstrated that UW solution exhibited a better protective effect in transplanted renal grafts in mice. UW solution is recommended for use in mouse KTX for reducing confounding factors such as IRI during surgery.


Assuntos
Transplante de Rim , Rim/efeitos dos fármacos , Rim/cirurgia , Soluções para Preservação de Órgãos/farmacologia , Preservação de Órgãos/métodos , Traumatismo por Reperfusão/prevenção & controle , Solução Salina/farmacologia , Adenosina/farmacologia , Alopurinol/farmacologia , Animais , Biomarcadores/sangue , Creatinina/sangue , Citoproteção , Taxa de Filtração Glomerular/efeitos dos fármacos , Glutationa/farmacologia , Receptor Celular 1 do Vírus da Hepatite A/sangue , Insulina/farmacologia , Rim/metabolismo , Rim/fisiopatologia , Transplante de Rim/efeitos adversos , Lipocalina-2/sangue , Masculino , Camundongos Endogâmicos C57BL , Preservação de Órgãos/efeitos adversos , Rafinose/farmacologia , Traumatismo por Reperfusão/sangue , Traumatismo por Reperfusão/etiologia , Traumatismo por Reperfusão/fisiopatologia , Fatores de Tempo
18.
Am J Physiol Renal Physiol ; 314(5): F1008-F1019, 2018 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-29412703

RESUMO

Chronic kidney disease (CKD) is a major health issue in the US. The typical five-sixths nephrectomy (typical 5/6 NX) is a widely used experimental CKD model. However, the typical 5/6 NX model is hypertensive in rats but strain dependent in mice. In particular, C57BL/6 mice with the typical 5/6 NX exhibits normal blood pressure and well-preserved renal function. The goal of the present study was to create a new hypertensive CKD model in C57BL/6 mice. We first characterized the vascular architecture originated from each renal artery branch by confocal laser-scanning microscopy with fluorescent lectin. Then, a novel 5/6 NX-BL model was generated by uninephrectomy combined with 2/3 renal infarction via a ligation of upper renal artery branch on the contralateral kidney. Compared with 5/6 NX-C, the 5/6 NX-BL model exhibited elevated mean arterial pressure (137.6 ± 13.9 vs. 104.7 ± 8.2 mmHg), decreased glomerular filtration rate (82.9 ± 19.2 vs. 125.0 ± 13.9 µl/min) with a reciprocal increase in plasma creatinine (0.31 ± 0.03 vs. 0.19 ± 0.04 mg/dl), and significant renal injury as assessed by proteinuria, histology with light, and transmission electron microscopy. In addition, inflammatory status, as indicated by the level of proinflammatory cytokine TNFα and the leukocyte counts, was significantly upregulated in 5/6 NX-BL compared with the 5/6 NX-C. In summary, we developed a new hypertensive CKD model in C57BL/6 mice with 5/6 renal mass reduction by uninephrectomy and upper renal artery branch ligation on the contralateral kidney. This 5/6 NX-BL model exhibits an infarction zone-dependent hypertension and progressive deterioration of the renal function accompanied by enhanced inflammatory response.


Assuntos
Pressão Arterial , Taxa de Filtração Glomerular , Hipertensão Renovascular/fisiopatologia , Inflamação/fisiopatologia , Rim/irrigação sanguínea , Rim/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Albuminúria/etiologia , Albuminúria/fisiopatologia , Albuminúria/urina , Animais , Biomarcadores/sangue , Biomarcadores/urina , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Hipertensão Renovascular/sangue , Hipertensão Renovascular/etiologia , Hipertensão Renovascular/patologia , Inflamação/sangue , Inflamação/etiologia , Inflamação/patologia , Mediadores da Inflamação/sangue , Rim/ultraestrutura , Ligadura , Camundongos Endogâmicos C57BL , Nefrectomia , Artéria Renal/fisiopatologia , Artéria Renal/cirurgia , Insuficiência Renal Crônica/sangue , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/patologia , Renina/sangue , Fatores de Tempo , Fator de Necrose Tumoral alfa/sangue
19.
Am J Physiol Renal Physiol ; 315(6): F1592-F1600, 2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30089032

RESUMO

Myogenic contraction of renal arterioles is an important regulatory mechanism for renal blood flow autoregulation. We have previously demonstrated that integrin-mediated mechanical force increases the occurrence of Ca2+ sparks in freshly isolated renal vascular smooth muscle cells (VSMCs). To further test whether the generation of Ca2+ sparks is a downstream signal of mechanotransduction in pressure-induced myogenic constriction, the relationship between Ca2+ sparks and transmural perfusion pressure was investigated in intact VSMCs of pressurized rat afferent arterioles. Spontaneous Ca2+ sparks were found in VSMCs when afferent arterioles were perfused at 80 mmHg. The spark frequency was significantly increased when perfusion pressure was increased to 120 mmHg. A similar increase of spark frequency was also observed in arterioles stimulated with ß1-integrin-activating antibody. Moreover, spark frequency was significantly higher in arterioles of spontaneous hypertensive rats at 80 and 120 mmHg. Spontaneous membrane current recorded using whole cell perforated patch in renal VSMCs showed predominant activity of spontaneous transient inward currents instead of spontaneous transient outward currents when holding potential was set close to physiological resting membrane potential. Real-time PCR and immunohistochemistry confirmed the expression of Ca2+-activated Cl- channel (ClCa) TMEM16A in renal VSMCs. Inhibition of TMEM16A with T16Ainh-A01 impaired the pressure-induced myogenic contraction in perfused afferent arterioles. Our study, for the first time to our knowledge, detected Ca2+ sparks in VSMCs of intact afferent arterioles, and their frequencies were positively modulated by the perfusion pressure. Our results suggest that Ca2+ sparks may couple to ClCa channels and trigger pressure-induced myogenic constriction via membrane depolarization.


Assuntos
Anoctamina-1/metabolismo , Pressão Arterial , Sinalização do Cálcio , Hipertensão/metabolismo , Rim/irrigação sanguínea , Mecanotransdução Celular , Músculo Liso Vascular/metabolismo , Miócitos de Músculo Liso/metabolismo , Vasoconstrição , Animais , Anoctamina-1/genética , Arteríolas/metabolismo , Arteríolas/fisiopatologia , Modelos Animais de Doenças , Hipertensão/genética , Hipertensão/fisiopatologia , Masculino , Potenciais da Membrana , Músculo Liso Vascular/fisiopatologia , Ratos Endogâmicos SHR , Ratos Sprague-Dawley
20.
Am J Physiol Renal Physiol ; 315(3): F628-F636, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29790388

RESUMO

Animal models of kidney transplantation (KTX) are widely used in studying immune response of hosts to implanted grafts. Additionally, KTX can be used in generating kidney-specific knockout animal models by transplantation of kidneys from donors with global knockout of a gene to wild-type recipients or vice versa. Dual-kidney transplantation (DKT) provides a more physiological environment for recipients than single-kidney transplantation (SKT). However, DKT in mice is rare due to technical challenges. In this study, we successfully performed DKT in mice and compared the hemodynamic response and graft function with SKT. The surgical time, complications, and survival rate of DKT were not significantly different from SKT, where survival rates were above 85%. Mice with DKT showed less injury and quicker recovery with lower plasma creatinine (Pcr) and higher glomerular filtration rate (GFR) than SKT mice (Pcr = 0.34 and 0.17 mg/dl in DKT vs. 0.50 and 0.36 mg/dl in SKT at 1 and 3 days, respectively; GFR = 215 and 131 µl/min for DKT and SKT, respectively). In addition, the DKT exhibited better renal functional reserve and long-term outcome of renal graft function than SKT based on the response to acute volume expansion. In conclusion, we have successfully generated a mouse DKT model. The hemodynamic responses of DKT better mimic physiological situations with less kidney injury and better recovery than SKT because of reduced confounding factors such as single nephron hyperfiltration. We anticipate DKT in mice will provide an additional tool for evaluation of renal significance in physiology and disease.


Assuntos
Taxa de Filtração Glomerular , Hemodinâmica , Transplante de Rim/métodos , Rim/fisiopatologia , Rim/cirurgia , Animais , Biomarcadores/sangue , Creatinina/sangue , Sobrevivência de Enxerto , Receptor Celular 1 do Vírus da Hepatite A/sangue , Rim/patologia , Transplante de Rim/efeitos adversos , Lipocalina-2/sangue , Masculino , Camundongos Endogâmicos C57BL , Modelos Animais , Natriurese , Recuperação de Função Fisiológica , Eliminação Renal , Sódio/urina , Fatores de Tempo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA