BACKGROUND & AIMS: :Aquaporins, major intrinsic proteins (MIPs) present in the plasma and intracellular membranes, facilitate the transport of small neutral molecules across cell membranes in higher plants. Recently, progress has been made in understanding the mechanisms of aquaporin subcellular localization, transport selectivity, and gating properties. Although the role of aquaporins in maintaining the plant water status has been addressed, the interactions between plant aquaporins and mineral nutrients remain largely unknown. This review highlights the roles of various aquaporin orthologues in mineral nutrient uptake and transport, as well as the regulatory effects of mineral nutrients on aquaporin expression and activity, and an integrated link between aquaporins and mineral nutrient metabolism was identified.

背景与目标： 水通道蛋白，存在于血浆和细胞内膜中的主要内在蛋白 (MIPs)，促进高等植物中小中性分子跨细胞膜的运输。最近，在了解水通道蛋白亚细胞定位，转运选择性和门控特性的机制方面取得了进展。尽管已经解决了水通道蛋白在维持植物水分状态中的作用，但植物水通道蛋白与矿物质营养素之间的相互作用仍然未知。本文重点介绍了各种水通道蛋白直系同源物在矿物质营养吸收和运输中的作用，以及矿物质营养对水通道蛋白表达和活性的调节作用，并确定了水通道蛋白与矿物质营养代谢之间的综合联系。

BACKGROUND & AIMS: PURPOSE/AIM:The development of retinal edema is the main reason of impaired vision in non-proliferative diabetic retinopathy. Water transport through aquaporins (AQPs) has been suggested to facilitate the development of ischemic edema in the retina. Here, we investigated whether experimental diabetic retinopathy in rats results in alterations of the AQP expression in the neural retina and retinal pigment epithelium (RPE). MATERIALS AND METHODS:Experimental diabetes in rats was induced by a single intravenous injection of streptozotocin (65 mg/kg body weight). The gene expression of AQPs in tissues from control and diabetic rats was examined by real-time RT-PCR. Retinal cryosections were immunostained against AQP5, 6, and 9. RESULTS:The total RNAs extracted from the neural retina and RPE contained gene transcripts for AQP0, 1, 3, 4, 5, 6, 8, 9, 11, and 12. Experimental diabetes was associated with an upregulation of AQP1 in the neural retina, and of AQP5, 9, 11, and 12 in the RPE. Furthermore, diabetes was associated with a downregulation of AQP6 and AQP11 in the neural retina, and of AQP0 in the RPE. AQP5 and AQP9 immunolabelings of the RPE were increased, and AQP6 labeling of the outer plexiform layer was decreased in retinal slices from diabetic rats in comparison to slices from control rats. CONCLUSIONS:The data suggest that experimental diabetic retinopathy is associated with a complex pattern of alteration in the retinal AQP expression. These alterations might be involved in the adaptation of retinal cells to hyperglycemic conditions and the development and/or resolution of retinal edema.

背景与目标：

BACKGROUND & AIMS: BACKGROUND:To study the expression pattern, localisation and potential clinical significance of aquaporin water channels (AQP) both in prostate cancer (PC) cell lines and in benign and malignant human prostate tissue. METHODS:The AQP transcript and protein expression of HPrEC, LNCaP, DU-145 and PC3 cell lines was investigated using reverse transcriptase polymerase chain reaction (RT-PCR) and immunofluorescence (IF) microscopy labelling. Immunohistochemistry (IHC) was performed to assess AQP protein expression in surgical specimens of benign prostatic hyperplasia as well as in PC. Tissue mRNA expression of AQPs was quantified by single-step reverse transcriptase quantitative polymerase chain reaction (qPCR). Relative gene expression was determined using the 40-ΔCT method and correlated to clinicopathological parameters. RESULTS:Transcripts of AQP 1, 3, 4, 7, 8, 10 and 11 were expressed in all four cell lines, while AQP 9 transcripts were not detected in malignant cell lines. IF microscopy confirmed AQP 3, 4, 5, 7 and 9 protein expression. IHC revealed highly heterogeneous AQP 3 protein expression in PC specimens, with a marked decrease in expression in tumours of increasing malignancy. Loss of AQP 9 was shown in PC specimens. mRNA expression of AQP3 was found to be negatively correlated to PSA levels (ρ = - 0.354; p = 0.013), D'Amico risk stratification (ρ = - 0.336; p = 0.012), ISUP grade (ρ = - 0.321; p = 0.017) and Gleason score (ρ = - 0.342; p = 0.011). CONCLUSIONS:This is the first study to systematically characterize human prostate cell lines, benign prostatic hyperplasia and PC in relation to all 13 members of the AQP family. Our results indicate the differential expression of several AQPs in benign and malignant prostate tissue. A significant correlation was observed between AQP 3 expression and tumour grade, with progressive loss in more malignant tumours. Taken together, AQPs may play a role in the progression of PC and AQP expression patterns may serve as a prognostic marker.

背景与目标：

BACKGROUND & AIMS: :This article reviews bone adaptation to microgravity, during manned space missions, in humans undergoing Head Down Tilt (HDT) and in Hind-Limb-Suspended Rats. Under microgravity conditions, bone loss occurs in association with hypercalciuria, which in turn modulates Aquaporin 2 (AQP2) excretion in urine, thus avoiding stone forming in space. This report discloses the need to prevent bone loss in order to prepare for long stays at lunar bases or voyages to Mars.

背景与目标： : 本文回顾了载人航天任务期间，经历头朝下倾斜 (HDT) 的人类和后肢悬吊大鼠的骨骼对微重力的适应。在微重力条件下，骨质流失与高钙尿症相关，从而调节尿液中水通道蛋白2 (AQP2) 的排泄，从而避免在太空中形成结石。该报告披露了防止骨质流失的必要性，以便为长期停留在月球基地或前往火星的航行做准备。

BACKGROUND & AIMS: :The membrane phosphoproteome in plant seed changes dynamically during embryo development. We examined the patterns of Phaseolus vulgaris (common bean) seed membrane protein phosphorylation from the mid-maturation stage until two days after germination. Serine and threonine phosphorylation declined during seed maturation while tyrosine phosphorylation remained relatively constant. We discovered that the aquaporin PvTIP3;1 is the primary seed membrane phosphoprotein, and PvTIP3;2 shows a very low level of expression. The level of phosphorylated Ser7 in PvTIP3;1 increased four-fold after seed maturation. Since phosphorylation increases water channel activity, we infer that water transport by PvTIP3;1 is highest in dry and germinating seeds, which would be optimal for seed imbibition. By the use of isoform-specific, polyclonal peptide antibodies, we found that PvTIP3;2 is expressed in a developmental pattern similar to PvTIP3;1. Unexpectedly, PvTIP3;2 is tyrosine phosphorylated following seed maturation, which may suggest a mechanism for the regulation of PvTIP3;2 following seed germination. Analysis of protein secondary structure by circular dichroism spectroscopy indicated that the amino-terminal domain of PvTIP3;1 is generally unstructured, and phosphorylation increases polyproline II (PPII) helical structure. The carboxy-terminal domain also gains PPII character, but in a pH-dependent manner. These structural changes are a first step to understand TIP3 aquaporin regulation.

背景与目标： : 植物种子中的膜磷酸蛋白质组在胚胎发育过程中动态变化。我们检查了从成熟中期到发芽后两天的菜豆 (普通豆) 种子膜蛋白磷酸化的模式。种子成熟过程中丝氨酸和苏氨酸磷酸化下降，而酪氨酸磷酸化保持相对恒定。我们发现水通道蛋白PvTIP3;1是主要的种子膜磷蛋白，而PvTIP3;2显示出非常低的表达水平。PvTIP3中磷酸化Ser7的水平; 1在种子成熟后增加了四倍。由于磷酸化增加了水通道的活性，因此我们推断PvTIP3;1在干燥和发芽的种子中最高，这对于种子吸收是最佳的。通过使用同工型特异性的多克隆肽抗体，我们发现PvTIP3;2以类似于PvTIP3的发育模式表达; 1。出乎意料的是，PvTIP3;2在种子成熟后被酪氨酸磷酸化，这可能暗示了调节PvTIP3的机制; 2在种子发芽后。通过圆二色光谱对蛋白质二级结构的分析表明，PvTIP3;1的氨基末端结构域通常是非结构化的，并且磷酸化会增加polyproline II (PPII) 螺旋结构。羧基末端结构域也具有PPII特性，但具有pH依赖性。这些结构变化是了解TIP3水通道蛋白调控的第一步。

BACKGROUND & AIMS: PURPOSE/AIM:To determine the transcriptional regulation of retinal aquaporins (AQPs) in rat models of transient and permanent retinal ischemia, and to prove the effects of chemical hypoxia, oxidative stress, glucose, and osmotic alterations on the expression of AQP9 in cultured human retinal pigment epithelium (RPE) cells. MATERIALS AND METHODS:Transient retinal ischemia-reperfusion in rats was induced by elevation of the intraocular pressure for 1 hour. Permanent retinal ischemia was induced by argon laser-induced retinal vein occlusion. The mRNA levels were determined one day after ischemia. RESULTS:Transient and permanent ischemia of the rat retina resulted in downregulation of AQPs 1, 3, 4, 5, 6, 8, and 11 in the RPE and/or neural retina. Pressure-induced transient retinal ischemia-induced upregulation of AQP9 in the neuroretina and RPE, and of AQ12 in the neuroretina. Retinal vein occlusion induced upregulation of AQP0 in the neuroretina and RPE, and of AQP9 and AQP12 in the neuroretina. In cultured human RPE cells, transcriptional expression of AQP9 was stimulated by chemical hypoxia, oxidative stress, VEGF, and high glucose. CONCLUSIONS:The data may suggest that the expression of retinal AQP9 is regulated by metabolic and oxidative stress. Upregulation of AQP9 in RPE cells may prevent lactic acidosis and subretinal edema under ischemic and oxidative stress conditions.

背景与目标：

BACKGROUND & AIMS: :The arbuscular mycorrhizal (AM) symbiosis has been shown to modulate the same physiological processes as the phytohormone abscisic acid (ABA) and to improve plant tolerance to water deficit. The aim of the present research was to evaluate the combined influence of AM symbiosis and exogenous ABA application on plant root hydraulic properties and on plasma-membrane intrinsic proteins (PIP) aquaporin gene expression and protein accumulation after both a drought and a recovery period. Results obtained showed that the application of exogenous ABA enhanced osmotic root hydraulic conductivity (L) in all plants, regardless of water conditions, and that AM plants showed lower L values than nonAM plants, a difference that was especially accentuated when plants were supplied with exogenous ABA. This effect was clearly correlated with the accumulation pattern of the different PIPs analyzed, since most showed reduced expression and protein levels in AM plants fed with ABA as compared to their nonAM counterparts. The possible involvement of plant PIP aquaporins in the differential regulation of L by ABA in AM and nonAM plants is further discussed.

背景与目标： : 丛枝菌根 (AM) 共生已被证明可以调节与植物激素脱落酸 (ABA) 相同的生理过程，并提高植物对缺水的耐受性。本研究的目的是评估干旱和恢复期后AM共生和外源ABA施用对植物根系水力特性以及质膜内在蛋白 (PIP) 水通道蛋白基因表达和蛋白质积累的综合影响。获得的结果表明，无论水分条件如何，外源ABA的施用均提高了所有植物的渗透根水力传导率 (L)，并且AM植物的L值低于nonAM植物，当向植物供应外源ABA时，这种差异尤其突出。这种效果与所分析的不同pip的积累模式明显相关，因为与nonAM对应物相比，大多数在饲喂ABA的AM植物中显示出降低的表达和蛋白质水平。进一步讨论了植物PIP水通道蛋白可能参与AM和nonAM植物中ABA对L的差异调节。

BACKGROUND & AIMS: :We compared the diffusion conductance to CO2 from the intercellular air space to the chloroplasts (internal conductance (g i)) between tobacco leaves acclimated to long-term drought (drought-acclimated (DA)) and those grown under sufficient irrigation (well-watered (WW)), and analysed the changes in g i in relation to the leaf anatomical characteristics and a possible CO2 transporter, aquaporin. The g i, which was estimated by combined analyses of CO2 gas exchange with chlorophyll fluorescence, in the DA plants was approximately half of that in the WW plants. The mesophyll and chloroplast surface areas exposing the intercellular air space, which potentially affect g i, were not significantly different between the WW and DA plants. The amounts of plasma membrane aquaporins (PIP), immunochemically determined using radish PIP antibodies, were unrelated to g i. After treatment with HgCl2, an aquaporin inhibitor, the water permeability of the leaf tissues (measured as the weight loss of fully-turgid leaf disks without the abaxial epidermis in 1 m sorbitol) in WW plants decreased with an increase in HgCl2 concentration. The g i in the WW plants decreased to similar levels to the DA plants when the detached leaflets were fed with 0.5 mm HgCl2. In contrast, both water permeability and g i were insensitive to HgCl2 treatments in DA plants. These results suggest that deactivation of aquaporins is responsible for the significant reduction in g i observed in plants growing under long-term drought.

背景与目标： : 我们比较了适应长期干旱 (干旱适应 (DA)) 的烟叶与在充足灌溉下生长的烟叶之间从细胞间空气空间到叶绿体 (内部电导 (g i)) 的CO2扩散电导 (WW))，并分析了g i与叶片解剖特征和可能的CO2转运蛋白水通道蛋白的关系。通过对DA植物中的CO2气体交换与叶绿素荧光的结合分析估算的g i大约是WW植物中的一半。暴露于细胞间空气空间的叶肉和叶绿体表面积可能会影响g i，在WW和DA植物之间没有显着差异。使用萝卜PIP抗体免疫化学测定的质膜水通道蛋白 (PIP) 的量与g i无关。用水通道蛋白抑制剂HgCl2处理后，随着HgCl2浓度的增加，WW植物叶片组织的透水性 (以1  m山梨糖醇中没有背面表皮的完全膨化的叶盘的重量损失来衡量) 降低。当分离的小叶饲喂0.5  mm hgcl2时，WW植物中的g i降低到与DA植物相似的水平。相反，透水性和g i对DA植物中的HgCl2处理均不敏感。这些结果表明，在长期干旱下生长的植物中，水通道蛋白的失活是导致g i显着降低的原因。

BACKGROUND & AIMS: :Skin function deteriorates with aging, and the dermal water content decreases. In this study, we have analyzed the mechanism of aging-related skin dryness focusing on aquaporins (AQPs), which are the water channels. Mice aged 3 and 20 months were designated as young and aged mice, respectively, to be used in the experiments. No differences were observed in transepidermal water loss between the young mice and aged mice. However, the dermal water content in aged mice was significantly lower than that in young mice, thus showing skin dryness. The expression of AQP1, AQP3, AQP4, AQP7, and AQP9 was observed in the skin. All the mRNA expression levels of these AQPs were significantly lower in aged mice. For AQP3, which was expressed dominantly in the skin, the protein level was lower in aged mice than in young mice. The results of the study showed that the expression level of AQPs in the skin decreased with aging, suggesting the possibility that this was one of the causes of skin dryness. New targets for the prevention and treatment of aging-related skin dryness are expected to be proposed when the substance that increases the expression of AQP3 is found.

背景与目标： : 皮肤功能随老化而恶化，真皮含水量下降。在这项研究中，我们分析了与衰老有关的皮肤干燥的机制，重点是水通道 (AQPs)，水通道是水通道。将3个月和20个月大的小鼠分别指定为年轻小鼠和老年小鼠，以用于实验。在年轻小鼠和老年小鼠之间的经表皮失水没有观察到差异。但是，老年小鼠的真皮水分含量显着低于年轻小鼠，因此显示出皮肤干燥。观察到AQP1，AQP3，AQP4，AQP7和AQP9在皮肤中的表达。在老年小鼠中，这些aqp的所有mRNA表达水平均显着降低。对于在皮肤中主要表达的AQP3，老年小鼠的蛋白质水平低于年轻小鼠。研究结果表明，AQPs在皮肤中的表达水平随着衰老而降低，这可能是皮肤干燥的原因之一。当发现增加AQP3表达的物质时，有望提出预防和治疗与衰老有关的皮肤干燥的新目标。

BACKGROUND & AIMS: :Aquaporins (AQPs) facilitate water transport across epithelia and play an important role in normal physiology and disease in the human airways. We used in situ hybridization and immunofluorescence to determine the expression and cellular localization of AQPs 5, 4, and 3 in human airway sections. In nose and bronchial epithelia, AQP5 is expressed at the apical membrane of columnar cells of the superficial epithelium and submucosal gland acinar cells. AQP4 was detected in basolateral membranes in ciliated ducts and by in situ in gland acinar cells. AQP3 is present on basal cells of both superficial epithelium and gland acinus. In these regions AQPs 5, 4, and 3 are appropriately situated to permit transepithelial water permeability. In the small airways (proximal and terminal bronchioles) AQP3 distribution shifts from basal cell to surface expression (i.e., localized to the apical membrane of proximal and terminal bronchioles) and is the only AQP identified in this region of the human lung. The alveolar epithelium has all three AQPs represented, with AQP5 and AQP4 localized to type I pneumocytes and AQP3 to type II cells. This study describes an intricate network of AQP expression that mediates water transport across the human airway epithelium.

背景与目标： : 水通道蛋白 (AQPs) 促进水跨上皮细胞的运输，并在人类呼吸道的正常生理和疾病中起重要作用。我们使用原位杂交和免疫荧光来确定人气道切片中AQPs 5、4和3的表达和细胞定位。在鼻和支气管上皮中，AQP5在浅表上皮和粘膜下腺泡细胞的柱状细胞的顶膜上表达。在纤毛导管的基底外侧膜中以及腺泡细胞的原位检测到AQP4。AQP3存在于浅表上皮和腺泡的基底细胞上。在这些区域中，AQPs 5、4和3的位置适当，以允许跨上皮透水。在小气道 (近端和末端细支气管) 中，AQP3的分布从基底细胞转移到表面表达 (即，定位于近端和末端细支气管的顶膜)，并且是在人类肺的该区域中唯一鉴定的AQP。肺泡上皮具有所有三个aqp代表，其中AQP5和AQP4定位于I型肺细胞，AQP3定位于II型细胞。这项研究描述了一个复杂的AQP表达网络，该网络介导水跨人类气道上皮的运输。

BACKGROUND & AIMS: :Aquaporins (AQPs) constitute an ancient and diverse protein family present in all living organisms, indicating a common ancient ancestor. However, during evolution, these organisms appear and evolve differently, leading to different cell organizations and physiological processes. Amongst the eukaryotes, an important distinction between plants and animals is evident, the most conspicuous difference being that plants are sessile organisms facing ever-changing environmental conditions. In addition, plants are mostly autotrophic, being able to synthesize carbohydrates molecules from the carbon dioxide in the air during the process of photosynthesis, using sunlight as an energy source. It is therefore interesting to analyze how, in these different contexts specific to both kingdoms of life, AQP function and regulation evolved. This review aims at highlighting similarities and differences between plant and mammal AQPs. Emphasis is given to the comparison of isoform numbers, their substrate selectivity, the regulation of the subcellular localization, and the channel activity.

背景与目标： : 水通道蛋白 (AQPs) 构成了一个古老而多样的蛋白质家族，存在于所有生物中，表明了一个共同的古老祖先。然而，在进化过程中，这些生物出现和进化不同，导致不同的细胞组织和生理过程。在真核生物中，植物和动物之间的重要区别是显而易见的，最明显的区别是植物是面对不断变化的环境条件的无梗生物。此外，植物大多是自养的，能够在光合作用的过程中，利用阳光作为能量来源，从空气中的二氧化碳中合成碳水化合物分子。因此，有趣的是，在这两个生命王国特有的不同环境中，AQP的功能和调节是如何演变的。这篇综述旨在强调植物和哺乳动物aqp之间的异同。重点是同工型数的比较，它们的底物选择性，亚细胞定位的调节和通道活性。

BACKGROUND & AIMS: :Xenopus laevis oocytes are a valuable tool for investigating the function of membrane proteins. However, regulations around the world, specifically in Brazil, render the import of Xenopus laevis frogs impractical, and, in some cases, impossible. Here, as an alternative, we evaluate the usefulness of the North American aquatic bullfrog Lithobates catesebeianus, which is commercially available in Brazil, for the heterologous expression of aquaporin (AQP) proteins. We have developed a method that combines a brief collagenase treatment and mechanical defolliculation for isolating individual oocytes from Lithobates ovaries. We find that they have a similar size, shape, and appearance to Xenopus oocytes and can tolerate and survive following injections with cRNA or water. Furthermore, surface biotinylation, western blot analysis, and measurements of osmotic water permeability (Pf) show that Lithobates oocytes can express AQPs to the plasma membrane and significantly increase the Pf of the oocytes. In fact, the Pf values are similar to historical values gathered from Xenopus oocytes. Due to the presence of a mercury sensitive cysteine (Cys or C) in the throat of the water channel, the Pf of oocytes expressing human (h) AQP1, hAQP1FLAG [FLAG, short protein tag (DYKDDDDK) added to the N-terminus of AQP1], hAQP8, and rat (r) AQP9 was inhibited with the mercurial compound p-chloromercuribenzene sulfonate (pCMBS), whereas AQPs lacking this Cys - hAQP1C189S mutant [residue Cys 189 was replaced by a serine (Ser or S)] and hAQP7 - were mercury insensitive. Contrary to previous studies with Xenopus oocytes, rAQP3 was also found to be insensitive to mercury, which is consistent with the mercury-sensitive Cys (Cys 11) being located intracellularly. Thus, we consider Lithobates oocytes to be a readily accessible system for the functional expression and study of membrane proteins for international researchers who do not currently have access to Xenopus oocytes.

背景与目标： 非洲爪蟾卵母细胞是研究膜蛋白功能的有价值的工具。然而，世界各地的法规，特别是巴西的法规，使得非洲爪蟾青蛙的进口不切实际，在某些情况下是不可能的。在这里，作为替代方案，我们评估了在巴西市售的北美水生牛蛙Lithobates catesebeianus对水通道蛋白 (AQP) 蛋白异源表达的有用性。我们已经开发了一种结合了简短的胶原酶治疗和机械去卵泡术的方法，用于从litobates卵巢中分离单个卵母细胞。我们发现它们的大小，形状和外观与非洲爪蟾卵母细胞相似，并且在注射cRNA或水后可以耐受并存活。此外，表面生物素化，蛋白质印迹分析和渗透水渗透率 (Pf) 的测量表明，岩质卵母细胞可以在质膜上表达AQPs，并显着增加卵母细胞的Pf。实际上，Pf值与从非洲爪蟾卵母细胞收集的历史值相似。由于水通道的喉咙中存在对汞敏感的半胱氨酸 (Cys或C)，表达人 (h) AQP1，hAQP1FLAG [FLAG，短蛋白标签 (DYKDDDDK) 的卵母细胞的Pf添加到AQP1的N端]，hAQP8，并且大鼠 (r) AQP9被汞化合物对氯代苯磺酸盐 (pCMBS) 抑制，而缺少该Cys-hAQP1C189S突变体的aqp [残基Cys 189被丝氨酸 (Ser或S) 取代] 和hAQP7-对汞不敏感。与先前对非洲爪蟾卵母细胞的研究相反，rAQP3也被发现对汞不敏感，这与汞敏感的Cys (Cys 11) 位于细胞内是一致的。因此，我们认为，对于目前无法获得非洲爪蟾卵母细胞的国际研究人员来说，这些卵母细胞是一种易于获得的膜蛋白功能表达和研究系统。

BACKGROUND & AIMS: :The phenotype analysis of transgenic mice deficient in specific aquaporin water channels has provided new insights into the role of aquaporins in organ physiology. AQP1-deficient mice are polyuric and are unable to concentrate their urine in response to water deprivation or vasopressin administration. AQP1 deletion reduces osmotic water permeability in the proximal tubule, thin descending limb of Henle and vasa recta, resulting in defective proximal tubule fluid absorption and medullary countercurrent exchange. Mice lacking AQP3, a basolateral membrane water channel expressed mainly in the cortical collecting duct, are remarkably polyuric but are able to generate a partly concentrated urine after water deprivation. In contrast, mice lacking AQP4, a water channel expressed mainly in the inner medullary collecting duct, manifest only a mild defect in maximum urinary concentrating ability. These data, together with phenotype analyses of the brain, lung, salivary gland, and gastrointestinal organs, support the paradigm that aquaporins can facilitate near-isosmolar transepithelial fluid absorption/secretion as well as rapid vectorial water movement driven by osmotic gradients. The phenotype data obtained from aquaporin knockout mice suggest the utility of aquaporin blockers as novel diuretic agents.

背景与目标： : 对缺乏特定水通道蛋白水通道的转基因小鼠的表型分析为水通道蛋白在器官生理学中的作用提供了新的见解。AQP1-deficient小鼠是多尿的，并且由于缺水或加压素给药而无法集中尿液。AQP1缺失降低了近端小管，Henle的细下降肢和血管直肠的渗透水渗透性，导致近端小管液吸收和髓质逆流交换有缺陷。缺乏AQP3 (主要在皮质收集管中表达的基底外侧膜水通道) 的小鼠具有明显的多尿性，但在缺水后能够产生部分浓缩的尿液。相反，缺乏AQP4 (主要在髓质内收集管中表达的水通道) 的小鼠仅表现出最大尿液浓缩能力的轻度缺陷。这些数据以及对大脑，肺，唾液腺和胃肠道器官的表型分析支持了水通道蛋白可以促进近等摩尔的跨上皮流体吸收/分泌以及由渗透梯度驱动的快速矢量水运动的范例。从水通道蛋白敲除小鼠获得的表型数据表明，水通道蛋白阻滞剂可作为新型利尿剂。

BACKGROUND & AIMS: :The brain maintains its mass and physiological functional capacity compared with other organs under harsh conditions such as starvation, a mechanism termed the 'selfish brain' theory. To further investigate this phenomenon, mice were examined following water and/or food deprivation. Although the body weights of the mice, the weight of the organs except the brain and blood glucose levels were significantly reduced in the absence of water and/or food, the brain weight maintained its original state. Furthermore, no significant differences in the water content of the brain or its energy balance were observed when the mice were subjected to water and/or food deprivation. To further investigate the mechanism underlying the brain maintenance of water and substance homeostasis, the expression levels of aquaporins (AQPs) and autophagy‑specific protein long‑chain protein 3 (LC3) were examined. During the process of water and food deprivation, no significant differences in the transcriptional levels of AQPs were observed. However, autophagy activity levels were initially stimulated, then suppressed in a time‑dependent manner. LC3 and AQPs have important roles for the survival of the brain under conditions of food and water deprivation, which provided further understanding of the mechanism underlying the 'selfish brain' phenomenon. Although not involved in the energy regulation of the 'selfish brain', AQPs were observed to have important roles in water and food deprivation, specifically with regards to the control of water content. Additionally, the brain exhibits an 'unselfish strategy' using autophagy during water and/or food deprivation. The present study furthered current understanding of the 'selfish brain' theory, and identified additional regulating target genes of AQPs and autophagy, with the aim of providing a basis for the prevention of nutrient shortage in humans and animals.

背景与目标： : 与其他器官相比，在饥饿等恶劣条件下，大脑保持其质量和生理功能能力，这种机制被称为 “自私的大脑” 理论。为了进一步研究这种现象，在缺水和/或食物缺乏后对小鼠进行了检查。尽管在没有水和/或食物的情况下，小鼠的体重，除大脑和血糖水平外的器官的重量显着降低，但大脑重量仍保持其原始状态。此外，当小鼠遭受水和/或食物剥夺时，没有观察到大脑含水量或其能量平衡的显着差异。为了进一步研究大脑维持水和物质稳态的机制，检查了水通道蛋白 (AQPs) 和自噬特异性蛋白长链蛋白3 (LC3) 的表达水平。在缺水和缺粮的过程中，没有观察到AQPs转录水平的显着差异。然而，自噬活性水平最初被刺激，然后以时间依赖的方式被抑制。LC3和aqp在食物和水匮乏的条件下对大脑的生存具有重要作用，这进一步了解了 “自私的大脑” 现象的潜在机制。尽管没有参与 “自私的大脑” 的能量调节，但据观察，aqp在水和食物匮乏中具有重要作用，特别是在控制水含量方面。此外，在缺水和/或食物匮乏期间，大脑表现出使用自噬的 “无私策略”。本研究进一步加深了对 “自私大脑” 理论的理解，并确定了其他调节AQPs和自噬的靶基因，旨在为预防人类和动物的营养短缺提供依据。

BACKGROUND & AIMS: :The proteins belonging to the aquaporin family play a fundamental role in water and solute transport across biological membranes. While the presence of these proteins has been extensively studied in somatic cells, their function in mammalian spermatozoa has been studied less. The present study was designed to identify and localise aquaglyceroporin 3 (AQP3) in boar spermatozoa. With this purpose, 29 fresh ejaculates from post-pubertal Piétrain boars were classified into two groups based upon their sperm quality and subsequently evaluated through western blot and immunofluorescence assessments. Western blotting showed the specific signal band of AQP3 at 25 kDa, whereas immunofluorescence assessments allowed us to identify two different AQP3 localisation patterns: (1) spermatozoa presenting a clear labelling located only in the mid-piece and (2) spermatozoa exhibiting a distribution pattern in the head and along the entire tail. The first staining pattern was predominant in all studied ejaculates. Despite individual differences in AQP3 content and localisation between boar ejaculates, these differences were not correlated with sperm quality. In conclusion, although AQP3 is present in boar spermatozoa in two different localisation patterns, neither the AQP3 content nor its localisation have been found to be associated with conventional sperm parameters.

背景与目标： : 水通道蛋白家族的蛋白质在跨生物膜的水和溶质运输中起着重要作用。尽管已在体细胞中广泛研究了这些蛋白质的存在，但对它们在哺乳动物精子中的功能的研究却较少。本研究旨在鉴定和定位野猪精子中的水甘油卟啉3 (AQP3)。为此，根据精子质量将来自青春期后pi é train公猪的29个新鲜射精分为两组，然后通过蛋白质印迹和免疫荧光评估进行评估。Western印迹显示AQP3的特定信号带为25 kDa，而免疫荧光评估使我们能够识别两种不同的AQP3定位模式 :( 1) 精子仅在中段显示清晰的标记，(2) 精子显示头部和整个尾部的分布模式。在所有研究的射精中，第一种染色模式均占主导地位。尽管AQP3含量和野猪射精之间的位置存在个体差异，但这些差异与精子质量无关。总之，尽管AQP3以两种不同的定位模式存在于野猪精子中，但尚未发现AQP3的含量及其定位与常规精子参数有关。