NCC

NCC
  • 文章类型: Case Reports
    神经囊虫病(NCC)是由猪带虫或猪肉tape虫引起的中枢神经系统感染。它影响全世界数百万人,是发展中国家癫痫的主要原因。NCC与颅内结核瘤的区分可能具有挑战性,结核病在发展中国家非常普遍。我们强调临床病史的重要性,包括暴露史和神经影像学,获得准确的诊断,以便及时治疗。本报告介绍了一名26岁男子的病例,该男子被诊断患有NCC,并表现为急性头晕和头痛。否则,无发热或全身症状史。神经影像学显示两个半球有多处脑部病变,大脑磁共振成像退化的脊柱。他口服阿苯达唑后恢复良好,吡喹酮,和皮质类固醇。此病例突出了NCC与颅内结核瘤的显着特征。早期和精确的诊断将确保患者获得最佳治疗,加速恢复,并防止进一步的并发症。
    Neurocysticercosis (NCC) is a central nervous system infection caused by Taenia solium or pork tapeworm. It affects millions worldwide and represents a leading cause of epilepsy in developing countries. NCC may be challenging to distinguish from intracranial tuberculomas, with tuberculosis being highly prevalent in developing countries. We highlight the importance of clinical history, including exposure history and neuroimaging, in obtaining an accurate diagnosis to enable prompt treatment. This report presents the case of a 26-year-old man diagnosed with NCC and presenting with acute giddiness and headache. Otherwise, there was no history of fever or constitutional symptoms. Neuroimaging demonstrated multiple cerebral lesions over both hemispheres, with degenerating scolex on brain MRI. He recovered well following a combination of oral albendazole, praziquantel, and corticosteroids. This case highlights the salient features that distinguish NCC from intracranial tuberculoma. Early and precise diagnosis will ensure that patients receive optimal treatment, expedite recovery, and prevent further complications.
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  • 文章类型: Case Reports
    脑囊虫病(NCC),一种由猪肉tape虫的幼虫形式引起的疾病,是全球获得性癫痫的常见原因,尤其是在卫生条件差的地区。虽然癫痫发作和头痛是常见的表现,导致单瘫的NCC病例极为罕见。这里,我们描述了一例42岁男性的特殊病例,他的左手突然出现无力和痉挛,而没有先前的损伤或其他全身症状.大脑的磁共振成像(MRI)显示右额顶叶单个囊性病变,表明NCC,这是他纯单瘫(PMM)的原因,没有任何感官损失。地塞米松和阿苯达唑治疗显著改善了他的运动能力,强调在单瘫的鉴别诊断中考虑NCC的必要性,特别是在流行地区。这个案例为NCC的临床谱增加了一个独特的视角,强调迅速和准确的诊断,然后适当的治疗在实现有利的结果的关键作用。
    Neurocysticercosis (NCC), a disease caused by the larval form of the pork tapeworm Taenia solium, is a common cause of acquired epilepsy globally, especially in areas with poor sanitation. While seizures and headaches are common manifestations, cases of NCC leading to monoparesis are exceedingly rare. Here, we describe a distinctive case of a 42-year-old male who developed sudden weakness and spasms in his left hand without prior injury or other systemic symptoms. Magnetic resonance imaging (MRI) of the brain revealed a single cystic lesion in the right frontoparietal lobe indicative of NCC, which was the cause of his pure motor monoparesis (PMM), without any sensory loss. Treatment with dexamethasone and albendazole substantially improved his motor abilities, highlighting the necessity of considering NCC in differential diagnoses for monoparesis, particularly in endemic areas. This case adds a unique perspective to the clinical spectrum of NCC, highlighting the critical role of prompt and accurate diagnosis followed by appropriate treatment in achieving favorable outcomes.
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  • 文章类型: Journal Article
    这篇综述强调了高血压中盐敏感性的分子基础,重点是调节远端肾单位的钠转运。该区域的钠重吸收通常与醛固酮的作用有关,尽管近年来已经报道了通过缺钾或钾负荷获得盐敏感性的醛固酮非依赖性途径的许多发现。这次讨论的关键是相互作用,通过细胞外钾浓度,在表达Na+-Cl-协同转运蛋白(NCC)的小管的第一部分和表达上皮钠通道(ENaC)的第二部分之间。分子途径如WNK-SPAK/OSR1信号,KLHL3-CUL3复合物,蛋白质磷酸酶和mTORC2-Nedd4L途径被描述为响应包括钾耗竭或负荷在内的生理条件变化而获得对血压的盐敏感性的机制。这篇综述强调了针对这些分子途径开发新的治疗盐敏感性高血压的治疗策略的潜力。其机制仍有待阐明。
    This review highlights the molecular basis of salt sensitivity in hypertension, with a focus on the regulation of sodium transport in the distal nephron. Sodium reabsorption in this region is often linked to the actions of aldosterone, although in recent years numerous findings have been reported on the aldosterone-independent pathway of acquiring salt sensitivity by potassium deficiency or potassium loading. The key to this discussion is the interplay, through extracellular potassium concentration, between the first part of the tubules expressing the Na+-Cl- cotransporter (NCC) and the second part expressing the epithelial sodium channel (ENaC). The molecular pathways such as WNK-SPAK/OSR1 signaling, KLHL3-CUL3 complex, protein phosphatases and mTORC2-Nedd4L pathway are described as the mechanism by which salt sensitivity on blood pressure is acquired in response to changes in physiological conditions including potassium depletion or loading. This review highlights the potential for targeting these molecular pathways to develop novel therapeutic strategies for the treatment of salt-sensitive hypertension, the mechanism of which remains to be elucidated.
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  • 文章类型: Journal Article
    近年来,几种理论的兴起表明,前额叶皮层(PFC)是视觉意识(NCC)的神经关联。这里特别流行的理论说PFC是视觉的“内容NCC”,即它包含那些不仅是意识所必需的大脑区域,但也要确定我们视觉体验的是什么(例如,我们体验的是绿色还是红色)。本文指出了PFC理论的这种“上层”形式与视觉体验的特征是不一致的:一方面,视觉意识似乎包含大量的内容,具有许多属性(例如对象,形状,或颜色)在视野的许多部分同时表示。另一方面,例如,PFC执行的功能(例如,注意力和工作记忆)各自专用于仅处理可用视觉刺激的相对小的子集。总之,PFC可能没有产生足够或正确的视觉表示来提供视觉体验中的所有内容,在这种情况下,PFC是视觉内容NCC的想法可能是错误的。本文还讨论了数据思想,以削弱视觉体验信息丰富(无意识失明,等。),与视觉理论一起使用“集合统计”来表示视野外围的特征。我认为,这些证据无法弥合视觉体验中所代表的视觉内容的数量与PFC中所代表的数量之间的巨大差距。
    Recent years have seen the rise of several theories saying that the prefrontal cortex (PFC) is a neural correlate of visual consciousness (NCC). Especially popular here are theories saying that the PFC is the \'content NCC\' for vision, i.e. it contains those brain areas that are not only necessary for consciousness, but also determine \'what\' it is that we visually experience (e.g. whether we experience green or red). This article points out how this \"upper-deck\" form of PFC theory is at odds with the character of visual experience: on the one hand, visual consciousness appears to contain copious amounts of content, with many properties (such as object, shape, or color) being simultaneously represented in many parts of the visual field. On the other hand, the functions that the PFC carries out (e.g. attention and working memory) are each dedicated to processing only a relatively small subset of available visual stimuli. In short, the PFC probably does not produce enough or the right kind of visual representations for it to supply all of the content found in visual experience, in which case the idea that the PFC is the content NCC for vision is probably false. This article also discusses data thought to undercut the idea that visual experience is informationally rich (inattentional blindness, etc.), along with theories of vision according to which \"ensemble statistics\" are used to represent features in the periphery of the visual field. I\'ll argue that these lines of evidence fail to close the apparently vast gap between the amount of visual content represented in the visual experience and the amount represented in the PFC.
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  • 文章类型: Journal Article
    钙调磷酸酶,蛋白磷酸酶2B(PP2B)或蛋白磷酸酶3(PP3),是钙依赖性丝氨酸/苏氨酸蛋白磷酸酶。钙调磷酸酶在肾脏中广泛表达并调节肾脏Na和K转运。在粗壮的上升肢体中,钙调神经磷酸酶通过促进协同转运蛋白和细胞内分选受体的去磷酸化来抑制NKCC2功能,称为排序相关受体与A型重复序列(SORLA),参与调节钙调磷酸酶对NKCC2的作用。钙调神经磷酸酶还参与调节远曲小管中的噻嗪敏感性NaCl协同转运蛋白(NCC)。钙调磷酸酶调节NCC的机制包括NCC的直接去磷酸化,调节Kelch样3/CUL3E3泛素连接酶复合物,负责WNK(无溶素激酶)泛素化,和抑制Kir4.1/Kir5.1,这决定了NCC的表达/活性。最后,钙调神经磷酸酶还参与调节皮质集合管中的ROMK(Kir1.1)通道和肾上腺肾小球带中的Cyp112表达。总之,钙调磷酸酶参与NKCC2、NCC、向内整流肾脏的K+通道,它还在调节肾上腺醛固酮合成中起作用,其调节上皮-Na+-通道表达/活性。因此,钙调磷酸酶抑制剂(CNIs)的应用有望突然钙调磷酸酶介导的肾脏跨上皮Na和K转运的调节。因此,CNIs导致高血压,损害肾脏K+排泄,并诱发高钾血症.
    Calcineurin, protein phosphatase 2B (PP2B) or protein phosphatase 3 (PP3), is a calcium-dependent serine/threonine protein phosphatase. Calcineurin is widely expressed in the kidney and regulates renal Na+ and K+ transport. In the thick ascending limb, calcineurin plays a role in inhibiting NKCC2 function by promoting the dephosphorylation of the cotransporter and an intracellular sorting receptor, called sorting-related-receptor-with-A-type repeats (SORLA), is involved in modulating the effect of calcineurin on NKCC2. Calcineurin also participates in regulating thiazide-sensitive NaCl-cotransporter (NCC) in the distal convoluted tubule. The mechanisms by which calcineurin regulates NCC include directly dephosphorylation of NCC, regulating Kelch-like-3/CUL3 E3 ubiquitin-ligase complex, which is responsible for WNK (with-no-lysin-kinases) ubiquitination, and inhibiting Kir4.1/Kir5.1, which determines NCC expression/activity. Finally, calcineurin is also involved in regulating ROMK (Kir1.1) channels in the cortical collecting duct and Cyp11 2 expression in adrenal zona glomerulosa. In summary, calcineurin is involved in the regulation of NKCC2, NCC, and inwardly rectifying K+ channels in the kidney, and it also plays a role in modulating aldosterone synthesis in adrenal gland, which regulates epithelial-Na+-channel expression/activity. Thus, application of calcineurin inhibitors (CNIs) is expected to abrupt calcineurin-mediated regulation of transepithelial Na+ and K+ transport in the kidney. Consequently, CNIs cause hypertension, compromise renal K+ excretion, and induce hyperkalemia.
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  • 文章类型: Journal Article
    高血压影响约2个美国成年人中的1个,性别在高血压的发病机理中起重要作用。氯化钠协同转运蛋白(NCC),由激酶网络调节,包括无赖氨酸激酶(WNK)1和WNK4,STE20/SPS1相关的脯氨酸富含丙氨酸激酶(SPAK),和氧化应激反应1(OxSR1)对于钠的重吸收和血压调节至关重要。膳食盐差异调节盐敏感性和耐盐大鼠的NCC,部分通过调节WNK/SPAK/OxSR1信号传导。在这些研究中,我们使用雄性和雌性SpragueDawley检验了NCC调节中的性别依赖性差异有助于血压盐敏感性的发展的假设,Dahl耐盐(DSR),和Dahl盐敏感(DSS)大鼠。在正常血压的耐盐SD和DSR大鼠中,高盐饮食引起NCC活性显着降低,表达式,和磷酸化。在男性中,这些变化与WNK1表达无变化,WNK4水平降低以及SPAK/OxSR1表达和磷酸化的抑制有关。相反,在女性中,与抑制SPAK/OxSR1表达和磷酸化相关的NCC活性降低。在高血压DSS大鼠中,雌性通过SPAK/OxSR1机制抑制NCC(与雄性相反)的能力可能有助于其盐敏感性高血压的幅度降低。总的来说,我们的发现支持在饮食盐摄入过程中NCC调节的雄性和雌性大鼠中存在性别差异,仅在雄性大鼠中抑制WNK4的表达,并且在雄性和雌性中都参与了SPAK/OxSR1信号传导。
    Hypertension affects approximately one in two United States adults and sex plays an important role in the pathogenesis of hypertension. The Na+-Cl- cotransporter (NCC), regulated by a kinase network including with-no-lysine kinase (WNK)1 and WNK4, STE20/SPS1-related proline alanine-rich kinase (SPAK), and oxidative stress response 1 (OxSR1), is critical to Na+ reabsorption and blood pressure regulation. Dietary salt differentially modulates NCC in salt-sensitive and salt-resistant rats, in part by modulation of WNK/SPAK/OxSR1 signaling. In this study, we tested the hypothesis that sex-dependent differences in NCC regulation contribute to the development of the salt sensitivity of blood pressure using male and female Sprague-Dawley (SD), Dahl salt-resistant (DSR), and Dahl salt-sensitive (DSS) rats. In normotensive salt-resistant SD and DSR rats, a high-salt diet evoked significant decreases in NCC activity, expression, and phosphorylation. In males, these changes were associated with no change in WNK1 expression, a decrease in WNK4 levels, and suppression of SPAK/OxSR1 expression and phosphorylation. In contrast, in females, there was decreased NCC activity associated with suppression of SPAK/OxSR1 expression and phosphorylation. In hypertensive DSS rats, the ability of females to suppress NCC (in opposition to males) via a SPAK/OxSR1 mechanism likely contributes to their lower magnitude of salt-sensitive hypertension. Collectively, our findings support the existence of sex differences in male versus female rats with NCC regulation during dietary salt intake involving suppression of WNK4 expression in male rats only and the involvement of SPAK/OxSR1 signaling in both males and females.NEW & NOTEWORTHY NCC regulation is sex dependent. In normotensive male and female Sprague-Dawley and Dahl salt-resistant rats, which exhibit dietary Na+-evoked NCC suppression, male rats exhibit decreased WNK4 expression and decreased SPAK and OxSR1 levels, whereas female rats only suppress SPAK and OxSR1. In hypertensive Dahl salt-sensitive rats, the ability of females to suppress NCC (in opposition to males) via a SPAK/OxSR1 mechanism likely contributes to their lower magnitude of salt-sensitive hypertension.
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  • 文章类型: Journal Article
    我们以前观察到延长雷帕霉素的给药时间,一种靶向哺乳动物雷帕霉素1(mTORC1)靶标的抑制剂,部分降低了Dahl盐敏感(SS)大鼠的高血压并减轻了肾脏炎症。相比之下,PP242是一种同时影响mTORC1/mTORC2的抑制剂,它不仅能完全预防高血压,还能对肾损伤提供实质性保护.值得注意的是,PP242表现出有效的利钠作用,而雷帕霉素则不明显。这项研究的主要目的是查明在接受0.4%NaCl(NS)或4.0%NaCl(HS)饮食的SS大鼠中,PP242的利钠作用的特定肾小管部位。PP242对利钠的急性影响,利尿剂,在未麻醉的SS大鼠中使用benzamil确定了利尿剂反应,呋塞米,或氢氯噻嗪(ENaC抑制剂,NKCC2或NCC,分别)单独或联合给药。研究结果表明,PP242对SS大鼠的利钠作用主要源于NCC的抑制和ENaC开放概率的降低。分子分析显示,mTORC2在体内通过蛋白磷酸化调节NCC活性和通过蛋白水解裂解调节ENaC活性。证据还表明,PP242还防止与NCC抑制相关的K+的损失。这些结果表明,PP242可能代表了抗高血压干预的一种改进的治疗方法。潜在的控制血压和减轻肾损伤的盐敏感的人类受试者。
    We have previously observed that prolonged administration of rapamycin, an inhibitor targeting the mammalian target of rapamycin complex (mTORC)1, partially reduced hypertension and alleviated kidney inflammation in Dahl salt-sensitive (SS) rats. In contrast, treatment with PP242, an inhibitor affecting both mTORC1/mTORC2, not only completely prevented hypertension but also provided substantial protection against kidney injury. Notably, PP242 exhibited potent natriuretic effects that were not evident with rapamycin. The primary objective of this study was to pinpoint the specific tubular sites responsible for the natriuretic effect of PP242 in SS rats subjected to either 0.4% NaCl (normal salt) or 4.0% NaCl (high salt) diet. Acute effects of PP242 on natriuretic, diuretic, and kaliuretic responses were determined in unanesthetized SS rats utilizing benzamil, furosemide, or hydrochlorothiazide [inhibitors of epithelial Na+ channel (ENaC), Na-K-2Cl cotransporter (NKCC2), or Na-Cl cotransporter (NCC), respectively] either administered alone or in combination. The findings indicate that the natriuretic effects of PP242 in SS rats stem predominantly from the inhibition of NCC and a reduction of ENaC open probability. Molecular analysis revealed that mTORC2 regulates NCC activity through protein phosphorylation and ENaC activity through proteolytic cleavage in vivo. Evidence also indicated that PP242 also prevents the loss of K+ associated with the inhibition of NCC. These findings suggest that PP242 may represent an improved therapeutic approach for antihypertensive intervention, potentially controlling blood pressure and mitigating kidney injury in salt-sensitive human subjects.NEW & NOTEWORTHY This study explored mechanisms underlying the natriuretic effects of mammalian target of rapamycin protein complex 2 inhibition using PP242 and revealed both epithelial Na+ channel and Na-Cl cotransporter in the distal tubular segments were potentially inhibited. These observations, with prior lab evidence, indicate that PP242 prevents hypertension via its potent inhibitory effects on these specific sodium transporters and by reducing renal immune responses. This dual action, coupled with potassium sparing effects, suggests an improved approach for managing hypertension and associated kidney damage.
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  • 文章类型: Journal Article
    先前对视觉感知中的意识神经相关性(NCC)的研究揭示了早期事件相关电位(ERP),视觉感知消极(VAN),与刺激意识相关联。然而,由于在以前的研究中使用了简短的刺激演示,目前尚不清楚意识相关阴性是否代表短暂的发作相关反应或对应于意识感知的持续时间。需要进行研究,以允许在有意识和无意识的条件下长时间呈现刺激。当前的ERP研究旨在通过使用新颖的刺激设计来应对这一挑战。男性和女性人类参与者(n=62)执行视觉任务,而与任务无关的线刺激在背景中呈现500或1000ms。线条刺激有时包含一张脸,这需要所谓的视觉一次性学习才能被看到。一半的参与者被告知面部的存在,导致面孔被知情的人感知,而不是被不知情的参与者感知。比较知情和不知情组之间的ERP显示,在整个刺激表现期间,枕颞叶电极的负电性增强。我们的结果表明,持续的视觉意识阴性(SVAN)与刺激呈现的持续时间有关。
    Previous research on the neural correlates of consciousness (NCC) in visual perception revealed an early event-related potential (ERP), the visual awareness negativity (VAN), to be associated with stimulus awareness. However, due to the use of brief stimulus presentations in previous studies, it remains unclear whether awareness-related negativities represent a transient onset-related response or correspond to the duration of a conscious percept. Studies are required that allow prolonged stimulus presentation under aware and unaware conditions. The present ERP study aimed to tackle this challenge by using a novel stimulation design. Male and female human participants (n = 62) performed a visual task while task-irrelevant line stimuli were presented in the background for either 500 or 1000 ms. The line stimuli sometimes contained a face, which needed so-called visual one-shot learning to be seen. Half of the participants were informed about the presence of the face, resulting in faces being perceived by the informed but not by the uninformed participants. Comparing ERPs between the informed and uninformed group revealed an enhanced negativity over occipitotemporal electrodes that persisted for the entire duration of stimulus presentation. Our results suggest that sustained visual awareness negativities (SVAN) are associated with the duration of stimulus presentation.
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  • 文章类型: Journal Article
    停止高血压(DASH)饮食的饮食方法,钠含量低,钾含量高,通过减少肾脏远曲小管中的钠再吸收而起到利尿剂的作用,但没有副作用。先前基于动物模型的研究没有探索人类离子通道蛋白的变化。最近对尿液细胞外囊泡(uEV)的见解表明,它们反映了肾脏组织和生理修饰。在我们的住院研究中,我们将高血压志愿者从美国饮食转变为DASH饮食,检查1期未经治疗的高血压患者的变化。我们分析了大量的纯uEV,从小到大,在三个时间点的九名志愿者的尿液样本中。这些uEV的质谱鉴定了1800种蛋白质,显示SCL12A3(NCC)增加,水通道蛋白2(AQP2)减少。免疫印迹显示从第5天到第11天,活化(磷酸化)NCC与总NCC的比率增加,AQP2降低,表明DASH饮食通过uEV蛋白丰度变化诱导可测量的肾脏反应。这种非侵入性方法为饮食的肾脏机制提供了新的见解。未来的研究应该在更大的队列中证实这些发现,澄清NCC和AQP2变化背后的驱动因素,它们对高血压的影响,并研究uEV是否也作为非活性蛋白质的废物途径,扩大我们对饮食对肾脏生理影响的理解。
    The dietary approach to stop hypertension (DASH) diet combines the antihypertensive effect of a low sodium and high potassium diet. In particular, the potassium component of the diet acts as a switch in the distal convoluted tubule to reduce sodium reabsorption, similar to a diuretic but without the side effects. Previous trials to understand the mechanism of the DASH diet were based on animal models and did not characterize changes in human ion channel protein abundance. More recently, protein cargo of urinary extracellular vesicles (uEVs) has been shown to mirror tissue content and physiological changes within the kidney. We designed an inpatient open label nutritional study transitioning hypertensive volunteers from an American style diet to DASH diet to examine physiological changes in adults with stage 1 hypertension otherwise untreated (Sacks FM, Svetkey LP, Vollmer WM, Appel LJ, Bray GA, Harsha D, Obarzanek E, Conlin PR, Miller ER 3rd, Simons-Morton DG, Karanja N, Lin PH; DASH-Sodium Collaborative Research Group. N Engl J Med 344: 3-10, 2001). Urine samples from this study were used for proteomic characterization of a large range of pure uEVs (small to large) to reveal kidney epithelium changes in response to the DASH diet. These samples were collected from nine volunteers at three time points, and mass spectrometry identified 1,800 proteins from all 27 samples. We demonstrated an increase in total SLC12A3 [sodium-chloride cotransporter (NCC)] abundance and a decrease in aquaporin-2 (AQP2) in uEVs with this mass spectrometry analysis, immunoblotting revealed a significant increase in the proportion of activated (phosphorylated) NCC to total NCC and a decrease in AQP2 from day 5 to day 11. This data demonstrates that the human kidney\'s response to nutritional interventions may be captured noninvasively by uEV protein abundance changes. Future studies need to confirm these findings in a larger cohort and focus on which factor drove the changes in NCC and AQP2, to which degree NCC and AQP2 contributed to the antihypertensive effect and address if some uEVs function also as a waste pathway for functionally inactive proteins rather than mirroring protein changes.NEW & NOTEWORTHY Numerous studies link DASH diet to lower blood pressure, but its mechanism is unclear. Urinary extracellular vesicles (uEVs) offer noninvasive insights, potentially replacing tissue sampling. Transitioning to DASH diet alters kidney transporters in our stage 1 hypertension cohort: AQP2 decreases, NCC increases in uEVs. This aligns with increased urine volume, reduced sodium reabsorption, and blood pressure decline. Our data highlight uEV protein changes as diet markers, suggesting some uEVs may function as waste pathways. We analyzed larger EVs alongside small EVs, and NCC in immunoblots across its molecular weight range.
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  • 文章类型: Journal Article
    钠-葡萄糖协同转运蛋白-2抑制剂(SGLT2i)降低高血压患者的血压(BP),然而精确的分子机制仍然难以捉摸。SGLT2i抑制血压正常的啮齿动物的近端小管(PT)NHE3介导的钠重吸收,然而,在这种情况下没有观察到降压作用。这项研究检查了依帕列净(EMPA)对正常血压和自发性高血压大鼠(SHR)肾小管钠转运的影响。它还检验了以下假设:正常血压大鼠中EMPA介导的PTNHE3抑制与远端肾单位顶端钠转运蛋白的上调有关。在12周龄的SHR中,EMPA给药14天可以降低BP,但在年龄匹配的Wistar大鼠中却没有。在Wistar和SHR中,通过EMPA处理抑制PTNHE3活性。在Wistar大鼠中,EMPA增加了NCC活动,mRNA表达,蛋白质丰度,和磷酸化水平,但不是在SHRs中。与Wistar大鼠相比,SHR显示出更高的NKCC2活性和切割的ENaCα和γ亚基的丰度,没有一个受到EMPA的影响。另一组雄性Wistar大鼠用EMPA治疗,NCC抑制剂氢氯噻嗪(HCTZ),EMPA联合HCTZ或媒介物14天。在这些老鼠身上,仅EMPA和HCTZ联合治疗观察到BP降低,不能单独使用任何一种药物。这些发现表明,在正常血压的雄性大鼠中,NCC上调抵消了EMPA介导的PTNHE3抑制,维持基线血压。此外,在实验模型和高血压患者中,NHE3活性降低而主要根尖钠转运体未进一步上调,这可能有助于SGLT2i的降低BP作用.
    Sodium-glucose cotransporter-2 inhibitors (SGLT2i) reduce blood pressure (BP) in patients with hypertension, yet the precise molecular mechanisms remain elusive. SGLT2i inhibits proximal tubule (PT) NHE3-mediated sodium reabsorption in normotensive rodents, yet no hypotensive effect is observed under this scenario. This study examined the effect of empagliflozin (EMPA) on renal tubular sodium transport in normotensive and spontaneously hypertensive rats (SHRs). It also tested the hypothesis that EMPA-mediated PT NHE3 inhibition in normotensive rats is associated with upregulation of distal nephron apical sodium transporters. EMPA administration for 14 days reduced BP in 12-wk-old SHRs but not in age-matched Wistar rats. PT NHE3 activity was inhibited by EMPA treatment in both Wistar and SHRs. In Wistar rats, EMPA increased NCC activity, mRNA expression, protein abundance, and phosphorylation levels, but not in SHRs. SHRs showed higher NKCC2 activity and an abundance of cleaved ENaC α and γ subunits compared with Wistar rats, none of which were affected by EMPA. Another set of male Wistar rats was treated with EMPA, the NCC inhibitor hydrochlorothiazide (HCTZ), and EMPA combined with HCTZ or vehicle for 14 days. In these rats, BP reduction was observed only with combined EMPA and HCTZ treatment, not with either drug alone. These findings suggest that NCC upregulation counteracts EMPA-mediated inhibition of PT NHE3 in male normotensive rats, maintaining their baseline BP. Moreover, the reduction of NHE3 activity without further upregulation of major apical sodium transporters beyond the PT may contribute to the BP-lowering effect of SGLT2i in experimental models and patients with hypertension.NEW & NOTEWORTHY This study suggests that reduced NHE3-mediated sodium reabsorption in the renal proximal tubule may account, at least in part, for the BP-lowering effect of SGLT2 inhibitors in the setting of hypertension. It also demonstrates that chronic treatment with SGLT2 inhibitors upregulates NCC activity, phosphorylation, and expression in the distal tubule of normotensive but not hypertensive rats. SGLT2 inhibitor-mediated upregulation of NCC seems crucial to counteract proximal tubule natriuresis in subjects with normal BP.
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