[Objective] This study was to explore the subcellular localization of aquaporins OsPIP2-6 in rice. [Method] A key rice aquaporins gene OsPIP2-6 was cloned and used for construction of a transient expression vector,whi...[Objective] This study was to explore the subcellular localization of aquaporins OsPIP2-6 in rice. [Method] A key rice aquaporins gene OsPIP2-6 was cloned and used for construction of a transient expression vector,which was then transformed into onion epidermis via particle bombardment for confocal microscopy analysis using YFP gene as a reporter gene. [Result] The results showed that rice aquaporins OsPIP2-6 was mainly located in the plasma membrane. [Conclusion] Our results provided theoretical basis for further understanding plant aquaporins.展开更多
Objective: The objective of this study was to investigate the effects of EA on EH and the regulation of AQP2 and AQP7 protein expression in rats.Methods: Twenty-four rats were allocated randomly to four groups of blan...Objective: The objective of this study was to investigate the effects of EA on EH and the regulation of AQP2 and AQP7 protein expression in rats.Methods: Twenty-four rats were allocated randomly to four groups of blank group, EH group,EH+tolvaptan group and EH + EA group(n = 6 per group). EH rat model was established by intraperitoneally injection of arginine vasopressin(AVP). EA was administered at acupoints "Baihui(百会 GV 20)"and "Tinggong(听宫 SI 19)". Rats in the EH + tolvaptan group and EH+ EA group were treated with tolvaptan and EA, respectively, after EH establishment. Hematoxylin-eosin staining was used to measure the cochlear hydrops degree, and then the ratio of scala media(SM) area to SM + scala vestibuli(SV) area(R value) was calculated. Immunohistochemical method was used to observe AQP2/AQP7 protein expression in the rat cochlear lateral wall after treatment.Results: ①There was no endolymphatic hydrops in the blank group. Reissner' s membrane was extended markedly and bulged into SV in cochleae of the EH group and endolymphatic hydrops was noted. Statistical analysis revealed that R value in the EH group showed a significant increase compared with that in the blank group(0.42 ± 0.02 vs. 0.31 ± 0.05, P=0.000). The distension of Reissner's membrane was less obvious in the EH + tolvaptan group and EH + EA group when compared with the EH group. R value in the EH + tolvaptan group and the EH + EA group was significantly less than that in EH group(0.32±0.04 vs. 0.42 ± 0.02, =0.001;0.35 ± 0.05 vs. 0.42 ± 0.02, P=0.012). The degree of the hydrops in the EH + EA group was not different from that in the EH + tolvaptan group(0.35 ± 0.05 vs. 0.32 ±0.04,P= 1.000). ②The AQP2 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(12.74 ± 5.18 vs. 5.92 ± 1.52, P = 0.014). The AQP2 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(6.52 ± 2.73 vs. 12.74 ± 5.18. P = 0.029;6.95 ± 3.10 vs. 12.74 ± 5.18, P = 0.047).The AQP2 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(6.95 ± 3.10 vs. 6.52 ± 2.73, P= 1.000).③The AQP7 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(30.32 ± 6.39 vs 16.64 ± 3.21, P=0.000). The AQP7 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(18.32 ± 2.45 vs.30.32 ± 6.39, P= 0.001;19.54 ± 4.61 vs. 30.32 ± 6.39, P= 0.003). The AQP7 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(19.54 ±4.61 vs. 18.32 ± 2.45, P= 1.000).Conclusions: These results indicate that repeated EA stimulation exerted the same effects as tolvaptan application on AQPs levels and subsequent aquaretic effects. And dehydrating effect of EA on the inner ear might be associated with its down-regulation of both AQP2 and AQP7 protein expression, thereby provide a potential molecular mechanism involved in the treatment of Meniere's disease by EA.展开更多
OBJECTIVE:To investigate whether Hetong decoction(和通汤,HTT)alleviates constipation via regulating AQPs expression.METHODS:Constipation in rats was induced by loperamide,and rats were randomly assigned into model(sal...OBJECTIVE:To investigate whether Hetong decoction(和通汤,HTT)alleviates constipation via regulating AQPs expression.METHODS:Constipation in rats was induced by loperamide,and rats were randomly assigned into model(saline),HHT-low(95 g/kg),HTT-medium(190 g/kg),HTT-high(380 g/kg)and positive control(mosapride)groups.Then the defecation function,the concentration of serum arginine vasopressin(AVP)and cyclic adenosine monophosphate(cAMP),and the expression of AQP3 and AQP8 in colon tissues were assessed.NCM460 colon cells with AQP3 and AQP8 knockdown or overexpression were exposed to serum from rats that received low or high dose of HTT,followed by detection of AQP3 and AQP8 expression.RESULTS:The model group showed lower fecal weight and water content,weaker intestinal transit,higher serum concentration of AVP and cAMP,increased proximal and distal AQP8 expression,increased proximal but decreased distal AQP3 expression.However,these trends were reversed in both the HTT group(low,medium and high dose)and the positive control group.In NCM460 cells,HTT dose-dependently stabilized AQP3 and AQP8 expression under AQP3/8 plasmid interference or overexpression.CONCLUSIONS:HTT relieves constipation in rats through regulating AQP3 and AQP8 expression.展开更多
Background:Aquaporins(AQPs)are a family of transmembrane water channels that includes orthodox AQPs,aquaglyceroporins(GLPs)and super AQPs.AQP3,AQP7,AQP9 and AQP11 have been identified in boar sperm,and they are crucia...Background:Aquaporins(AQPs)are a family of transmembrane water channels that includes orthodox AQPs,aquaglyceroporins(GLPs)and super AQPs.AQP3,AQP7,AQP9 and AQP11 have been identified in boar sperm,and they are crucial for sperm maturation and osmoregulation.Water exchange is an important event in cryopreservation,which is the most efficient method for long-term storage of sperm.However,the freezethaw process leads to sperm damage and a loss of fertilizing potential.Assuming that the quality of frozenthawed sperm partially depends on the regulation of osmolality variations during this process,AQPs might play a crucial role in boar semen freezability.In this context,the aim of this study was to unravel the functional relevance of the different groups of AQPs for boar sperm cryotolerance through three different inhibitors.Results:Inhibition of different groups of AQPs was found to have different effects on boar sperm cryotolerance.Whereas the use of 1,3-propanediol(PDO),an inhibitor of orthodox AQPs and GLPs,decreased total motility(P<0.05),it increased post-thaw sperm viability,lowered membrane lipid disorder and increased mitochondrial membrane potential(MMP)(P<0.05).When acetazolamide(AC)was used as an inhibitor of orthodox AQPs,the effects on post-thaw sperm quality were restricted to a mild increase in MMP in the presence of the intermediate concentration at 30 min post-thaw and an increase in superoxide levels(P<0.05).Finally,the addition of phloretin(PHL),a GLP inhibitor,had detrimental effects on post-thaw total and progressive sperm motilities,viability and lipid membrane disorder(P<0.05).Conclusions:The effects of the different inhibitors suggest that GLPs rather than orthodox AQPs are relevant for boar sperm freezability.Moreover,the positive effect of PDO on sperm quality suggests a cryoprotective role for this molecule.展开更多
Rotavirus diarrhea is a major worldwide cause of infantile gastroenteritis; however, the mechanism responsible for intestinal fluid loss remains unclear. Water transfer across the intestinal epithelial membrane seems ...Rotavirus diarrhea is a major worldwide cause of infantile gastroenteritis; however, the mechanism responsible for intestinal fluid loss remains unclear. Water transfer across the intestinal epithelial membrane seems to occur because of aquaporins(AQPs). Accumulating evidence indicates that alterations in AQPs may play an important role in pathogenesis. Here, we focus on changes in AQPs in a mouse model of rotavirus diarrhea. In the present study, 32 of 35 mice developed diarrhea and mild dehydration within 24 hours after infection with rotavirus strain SA11. Intestinal epithelial cells demonstrated cytoplasmic vacuolation, malaligned villi, and atrophy. AQP1 expression was significantly attenuated in the ileum and colon in comparison with controls; likewise, AQP4 and-8 protein expression were significantly decreased in the colon of rotavirus diarrhea-infected mice. In contrast, AQP3 protein expression was significantly increased in the colon of rotavirus-infected mice in comparison with controls. These results indicate that rotavirus diarrhea is associated with the downregulation of AQP1,-4, and-8 expression. Therefore, AQPs play an important role in rotavirus diarrhea.展开更多
This review focuses on current knowledge on hepato-cyte aquaporins(AQPs)and their significance in bile formation and cholestasis.Canalicular bile secretion results from a combined interaction of several solute transpo...This review focuses on current knowledge on hepato-cyte aquaporins(AQPs)and their significance in bile formation and cholestasis.Canalicular bile secretion results from a combined interaction of several solute transporters and AQP water channels that facilitate water flow in response to the osmotic gradients created. During choleresis,hepatocytes rapidly increase their canalicular membrane water permeability by modulating the abundance of AQP8.The question was raised as to whether the opposite process,i.e.a decreased canalicular AQP8 expression would contribute to the development of cholestasis.Studies in several experimental models of cholestasis,such as extrahepatic obstructive cholestasis,estrogen-induced cholestasis, and sepsis-induced cholestasis demonstrated that the protein expression of hepatocyte AQP8 was impaired. In addition,biophysical studies in canalicular plasma membranes revealed decreased water permeability associated with AQP8 protein downregulation.The combined alteration in hepatocyte solute transporters and AQP8 would hamper the efficient coupling of osmotic gradients and canalicular water flow.Thus cholestasis may result from a mutual occurrence of impaired solute transport and decreased water permeability.展开更多
AIM: To investigate whether the regulation of aquaporin 3 (AQP3) and AQP9 induced by Auphen and dibutyryl cAMP (dbcAMP) inhibits hepatic tumorigenesis.METHODS: Expression of AQP3 and AQP9 was detected by Western blot,...AIM: To investigate whether the regulation of aquaporin 3 (AQP3) and AQP9 induced by Auphen and dibutyryl cAMP (dbcAMP) inhibits hepatic tumorigenesis.METHODS: Expression of AQP3 and AQP9 was detected by Western blot, immunohistochemistry (IHC), and RT-PCR in HCC samples and paired non-cancerous liver tissue samples from 30 hepatocellular carcinoma (HCC) patients. A xenograft tumor model was used in vivo. Nine nude mice were divided into control, Auphen-treated, and dbcAMP-treated groups (n = 3 for each group). AQP3 and AQP9 protein expression after induction of xenograft tumors was detected by IHC and mRNA by RT-PCR analysis. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and histological evaluation were used to detect apoptosis of tumor cells, and the concentration of serum α-fetoprotein (AFP) was measured using RT-PCR and an ELISA kit.RESULTS: The volumes and weights of tumors decreased significantly in the Auphen- and dbcAMP-treated mice compared with the control mice (P < 0.01). The levels of AQP3 were significantly lower in the Auphen treatment group, and levels of AQP9 were significantly higher in thedbcAMP treatment mice than in the control mice (P < 0.01). The reduction of AQP3 by Auphen and increase of AQP9 by dbcAMP in nude mice suppressed tumor growth of HCC, which resulted in reduced AFP levels in serum and tissues, and apoptosis of tumor cells in the Auphen- and dbcAMP-treated mice, when compared with control mice (P < 0.01). Compared with para-carcinoma tissues, AQP3 expression increased in tumor tissues whereas the expression of AQP9 decreased. By correlating clinicopathological and expression levels, we demonstrated that the expression of AQP3 and AQP9 was correlated with clinical progression of HCC and disease outcomes.CONCLUSION: AQP3 increases in HCC while AQP9 decreases. Regulation of AQP3 and AQP9 expression by Auphen and dbcAMP inhibits the development and growth of HCC.展开更多
Plasma membrane intrinsic proteins(PIPs)are conserved plant aquaporins that transport small molecules across the plasma membrane to trigger instant stress responses and maintain cellular homeostasis under biotic and a...Plasma membrane intrinsic proteins(PIPs)are conserved plant aquaporins that transport small molecules across the plasma membrane to trigger instant stress responses and maintain cellular homeostasis under biotic and abiotic stress.To elucidate their roles in plant immunity to pathogen attack,we characterized the expression patterns,subcellular localizations,and H_(2)O_(2)-transport ability of 11 OsPIPs in rice(Oryza sativa),and identified OsPIP2;6 as necessary for rice disease resistance.OsPIP2;6 resides on the plasma membrane and facilitates cytoplasmic import of the immune signaling molecule H_(2)O_(2).Knockout of OsPIP2;6 increases rice susceptibility to Magnaporthe oryzae,indicating a positive function in plant immunity.OsPIP2;6 interacts with OsPIP2;2,which has been reported to increase rice resistance to pathogens via H_(2)O_(2)transport.Our findings suggest that OsPIP2;6 cooperates with OsPIP2;2 as a defense signal transporter complex during plant–pathogen interaction.展开更多
Compared to other organisms,plants have evolved a greater number of aquaporins with diverse substrates and functions to adapt to ever-changing environmental and internal stimuli for growth and development.Although aqu...Compared to other organisms,plants have evolved a greater number of aquaporins with diverse substrates and functions to adapt to ever-changing environmental and internal stimuli for growth and development.Although aquaporins were initially identified as channels that allow water molecules to cross biological membranes,progress has been made in identifying various novel permeable substrates.Many studies have characterized the versatile physiological and biophysical functions of plant aquaporins.Here,we review the recent reports that highlight aquaporin-facilitated regulation of major physiological processes and stress tolerance throughout plant life cycles as well as the potential prospects and possibilities of applying aquaporins to improve agricultural productivity,food quality,environmental protection,and ecological conservation.展开更多
Background Aquaporins(AQPs)are integral membrane proteins belonging to the major intrinsic protein(MIP)family,playing a crucial role in water transport,cell elongation,and stress responses.However,their evolutionary d...Background Aquaporins(AQPs)are integral membrane proteins belonging to the major intrinsic protein(MIP)family,playing a crucial role in water transport,cell elongation,and stress responses.However,their evolutionary dynamics and functional roles in Gossypium species remain poorly characterized.Results In the present study,a total of 55,54,54,103,106,108,and 104 AQP genes were found in G.herbaceum,G.arboreum,G.raimondii,G.barbadense,G.tomentosum,G.mustelinum,and G.darwinii,respectively.Phylogenetic analysis classified them into five conserved subfamilies(PIP,TIP,NIP,SIP,and XIP),with 95 genes showing synteny across species and 17 displaying divergence,suggesting subgenome differentiation.Transcriptome analysis revealed that specific Gb AQP genes are involved in early salt stress responses and fiber development.Physiological assays demonstrated stronger salt tolerance in tetraploid cottons,particularly G.darwinii,compared with diploids.Co-expression network analysis linked AQPs to abiotic stress and fiber traits,and virus-induced gene silencing(VIGS)confirmed four AQP genes as critical for salt tolerance.Conclusion This study provides comprehensive insights into the evolution,expression,and functional roles of AQPs in cotton,identifying key candidate genes for improving salt tolerance and fiber quality in Gossypium species.展开更多
Objective To investigate the effects and mechanisms of leonurine,an active component of Chinese motherwort(Leonurus japonicus Houtt.)which capable of activating blood circulation and eliminating water-dampness,on acut...Objective To investigate the effects and mechanisms of leonurine,an active component of Chinese motherwort(Leonurus japonicus Houtt.)which capable of activating blood circulation and eliminating water-dampness,on acute kidney injury(AKI)from the perspective of aquaporins(AQP).Methods Forty C57BL/6 mice were randomly divided into control group,AKI model group,and leonurine treatment groups(low-dose,medium-dose and high-dose),with 8 mice in each group.Except for thecontro1lgroup,miceini eachgroup were intraperitoneally injected with cisplatin to construct the AKImodel.Theintervention1groups were preadministered with leonurine for 3 days before modeling,and lasted for 7 consecutive days,with the dosages of 20,40,80O mg/kg,respectively.Control group and model groupp were gavaged with the equal volume of purified water.After 72 hours of modeling,the serum creatinine and urea nitrogen levels of all mice were examined to determine the optimal dose of leonurine.HE staining was performed to observe the pathological changes of kidneys.Immunohistochemistry and Western Blot were performed to detect the location and relative expression of the AQPs(AQP1-4)among different groups.Results Compared with the control group,the creatinine and urea nitrogen levels in model group were significantly increased(P<0.05).Renal pathological staining showed that,compared with the control group,the renal tubules in the model group had focal lesions,with some of the luminal surfaces of tubular cells with brush border detachment and cell flattening,whereas the lesions in the leonurine-treated group were significantly reduced.Compared with the control group,the protein expressions of AQP1,AQP2 and AQP4 in mice of the model group were significantly reduced(P<0.01,P<0.05).Compared with the model group,the creatinine and urea nitrogen levels reduced,and the protein expressions of AQP1 and AQP3 were elevated in the high-dose leonurine treatment group(P<0.01,P<O.05).Conclusion Leonurine can reduce creatinine and urea nitrogen levels and alleviate renal pathological injury of AKI,which may be associated with the regulation of AQPs.展开更多
Aquaporins(AQPs)are highly conserved small transmembrane proteins,which are responsible for the water transport across the cell membrane.AQPs are abundantly expressed in numerous types of cells such as epithelial and ...Aquaporins(AQPs)are highly conserved small transmembrane proteins,which are responsible for the water transport across the cell membrane.AQPs are abundantly expressed in numerous types of cells such as epithelial and endothelial cells.The expression of AQP-1,-3,-4,-5,-8 and-9 were found in the digestive system,where these six AQP isoforms serve essen-tial roles including mediating the transmembrane water transport and regulating the secretion of gastrointestinal(GI)fluids,consequently facilitating the digestion and absorption of GI con-tents.In addition,the expression levels of AQPs are controlled by various factors,and AQPs can stimulate numerous signaling pathways;however,aberrant expression of AQPs in the GI tracts are associated with the initiation and development of numerous diseases.Thus,this re-view provides an overview of the expression and functions of AQPs in the digestive system.展开更多
With the support of the National Natural Science Foundation of China,Prof.Ye Qing’s laboratory at South China Botanical Garden,Chinese Academy of Sciences,reported differential regulatory mechanisms of AQPs in mediat...With the support of the National Natural Science Foundation of China,Prof.Ye Qing’s laboratory at South China Botanical Garden,Chinese Academy of Sciences,reported differential regulatory mechanisms of AQPs in mediating plant water transport under osmotic or salt stresses,which was published in Plant,Cell and Environment(2014,doi:10.1111/pce.12319).展开更多
Aquaporins are channels facilitating the diffusion of water and/or small uncharged solutes ecross biological membranes. They assemble as homotetramers but some of them also form heterotetramers, especially in plants. ...Aquaporins are channels facilitating the diffusion of water and/or small uncharged solutes ecross biological membranes. They assemble as homotetramers but some of them also form heterotetramers, especially in plants. In Zea mays, aquaporins belonging to the plasma membrane intrinsic protein （PIP） subfamily are clustered into two groups, PIP1 and PIP2, which exhibit different water-channel activities when expressed in Xenopus oocytes. When PIP1 and PIP2 isoforms are co-expressed, they physically interact to modulate their subcellular localization and channel activity. Here, we demonstrated by affinity chromatography purification that, when co-expressed in Xenopus oocytes, the maize PIP1;2 and PIP2;5 isoforms assemble as homo- and heterodimers within heterotetramers. We built the 3D structure of such heterotetramers by comparative modeling on the basis of the spinach SoPIP2;1 X-ray structure and identified amino acid residues in the transmembrane domains which putatively interact at the interfaces between monomers. Their roles in the water-channel activity, subcellular localization, protein abundance, and physical interac- tion were investigated by mutagenesis. We highlighted single-residue substitutions that either inactivated PIP2;5 or activated PIP1;2 without affecting their interaction. Interestingly, the Phe220Ala mutation in the transmembrane domain 5 of PIP1 ;2 activated its water-channel activity and, at the same time, inactivated PIP2;5 within a heterotetramer. Altogether, these data contribute to a better understanding of the interaction mechanisms between PIP isoforms and the role of heterotetramerization on their water-channel activity.展开更多
Background:Determining the expression and functions of aquaporins(AQPs)in the adult kidney has generated important information about the roles of this protein family in the renal regulation of water homeostasis.Howeve...Background:Determining the expression and functions of aquaporins(AQPs)in the adult kidney has generated important information about the roles of this protein family in the renal regulation of water homeostasis.However,limited information describes the expression of AQPs in fetal kidneys,and most reports on fetal renal AQPs originate from animal studies.Although there are the maturation and regulation of the renalconcentrating mechanism,the ways in which changes in the expression of AQPs contribute to the formation of urine during the perinatal period remain unclear.Data sources:This review summarizes current knowledge about the spatial and temporal expression patterns of AQP1,AQP2,AQP3,and AQP4 in the fetal and postnatal kidneys in different animal species and in human beings.Results:AQP1 and AQP2 expression can be detected earlier in gestation in human beings and sheep compared with mice and rats.AQP1 expression is detected earlier in the proximal tubules than the expression of AQP2,AQP3,and AQP4 in the collecting ducts.Conclusion:Further studies investigating the regulation of AQPs during kidney development may provide insights into normal water-handling mechanisms and the pathophysiology of fetal kidneys,which may determine new directions for the clinical treatment of kidney diseases.展开更多
Aquapodns are a group of membrane proteins, which are known as the passages of water molecules transforming through the biological membrane lipid bilayer and distributing in almost all of the organs and tissues of liv...Aquapodns are a group of membrane proteins, which are known as the passages of water molecules transforming through the biological membrane lipid bilayer and distributing in almost all of the organs and tissues of living creatures. Aquaporins play important roles in maintaining water balance and internal environment stability. As a new entry point, aquaporins are involved in the researches on water metabolism, physiological regulation and pathological essence in viscera-state more and more widely in recent years. The literature on traditional Chinese medical studies, which related to aquaporins and were published in the last decade, was reviewed and the progress on application of aquaporin in Chinese medicine was summarized in this paper.展开更多
Neonicotinoids(NEOs),a large class of organic compounds,are a type of commonly used pesticide for crop protection.Their uptake and accumulation in plants are prerequisites for their intra-and intercellular move-ments,...Neonicotinoids(NEOs),a large class of organic compounds,are a type of commonly used pesticide for crop protection.Their uptake and accumulation in plants are prerequisites for their intra-and intercellular move-ments,transformation,and function.Understanding the molecular mechanisms that underpin NEO uptake by plants is crucial for effective application,which remains elusive.Here,we demonstrate that NEOs enter plant cells primarily through the transmembrane symplastic pathway and accumulate mainly in the cytosol.Two plasma membrane intrinsic proteins discovered in Brassica rapa,BraPIP1;1 and BraPIP2;1,were found to encode aquaporins(AQPs)that are highly permeable to NEOs in different plant species and facilitate NEO subcellular diffusion and accumulation.Their conserved transport function was further demonstrated in Xenopus laevis oocyte and yeast assays.BraPIP1;1 and BraPIP2;1 gene knockouts and interaction as-says suggested that their proteins can form functional heterotetramers.Assessment of the potential of mean force indicated a negative correlation between NEO uptake and the energy barrier of BraPIP1;1 chan-nels.This study shows that AQPs transport organic compounds with greater osmolarity than previously thought,providing new insight into the molecular mechanisms of organic compound uptake and facilitating innovations in systemic pesticides.展开更多
Aquaporins are water channel proteins that mediate the fine-tuning of cell membrane water permeability during development or in response to environmental stresses. The present work focuses on the oxidative stress-indu...Aquaporins are water channel proteins that mediate the fine-tuning of cell membrane water permeability during development or in response to environmental stresses. The present work focuses on the oxidative stress-induced redistribution of plasma membrane intrinsic protein （PIP） aquaporins from the plasma membrane （PM） to intracellular membranes. This process was investigated in the Arabidopsis root. Su- crose density gradient centrifugation showed that exposure of roots to 0.5 mM H2O2 induces significant depletion in PM fractions of several abundant PIP homologs after 15 rain. Analyses by single-particle tracking and fluorescence correlative spectroscopy showed that, in the PM of epidermal cells, H2O2 treat- ment induces an increase in lateral motion and a reduction in the density of a fluorescently tagged form of the prototypal AtPIP2;1 isoform, respectively. Co-expression analyses of AtPIP2;1 with endomembrane markers revealed that H2O2 triggers AtPIP2;1 accumulation in the late endosomal compartments. Life- time analyses established that the high stability of PIPs was maintained under oxidative stress conditions, suggesting that H2O2 triggers a mechanism for intracellular sequestration of PM aquaporins without further degradation. In addition to information on cellular regulation of aquaporins, this study provides novel and complementary insights into the dynamic remodeling of plant internal membranes during oxida- tive stress responses.展开更多
基金Supported by Program for Science and Technology Development in Shijiazhuang City(10120803)Doctoral Research Fund of Shijiazhuang University(2007012)~~
文摘[Objective] This study was to explore the subcellular localization of aquaporins OsPIP2-6 in rice. [Method] A key rice aquaporins gene OsPIP2-6 was cloned and used for construction of a transient expression vector,which was then transformed into onion epidermis via particle bombardment for confocal microscopy analysis using YFP gene as a reporter gene. [Result] The results showed that rice aquaporins OsPIP2-6 was mainly located in the plasma membrane. [Conclusion] Our results provided theoretical basis for further understanding plant aquaporins.
基金Supported by the National Natural Science Foundation of China:81704153
文摘Objective: The objective of this study was to investigate the effects of EA on EH and the regulation of AQP2 and AQP7 protein expression in rats.Methods: Twenty-four rats were allocated randomly to four groups of blank group, EH group,EH+tolvaptan group and EH + EA group(n = 6 per group). EH rat model was established by intraperitoneally injection of arginine vasopressin(AVP). EA was administered at acupoints "Baihui(百会 GV 20)"and "Tinggong(听宫 SI 19)". Rats in the EH + tolvaptan group and EH+ EA group were treated with tolvaptan and EA, respectively, after EH establishment. Hematoxylin-eosin staining was used to measure the cochlear hydrops degree, and then the ratio of scala media(SM) area to SM + scala vestibuli(SV) area(R value) was calculated. Immunohistochemical method was used to observe AQP2/AQP7 protein expression in the rat cochlear lateral wall after treatment.Results: ①There was no endolymphatic hydrops in the blank group. Reissner' s membrane was extended markedly and bulged into SV in cochleae of the EH group and endolymphatic hydrops was noted. Statistical analysis revealed that R value in the EH group showed a significant increase compared with that in the blank group(0.42 ± 0.02 vs. 0.31 ± 0.05, P=0.000). The distension of Reissner's membrane was less obvious in the EH + tolvaptan group and EH + EA group when compared with the EH group. R value in the EH + tolvaptan group and the EH + EA group was significantly less than that in EH group(0.32±0.04 vs. 0.42 ± 0.02, =0.001;0.35 ± 0.05 vs. 0.42 ± 0.02, P=0.012). The degree of the hydrops in the EH + EA group was not different from that in the EH + tolvaptan group(0.35 ± 0.05 vs. 0.32 ±0.04,P= 1.000). ②The AQP2 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(12.74 ± 5.18 vs. 5.92 ± 1.52, P = 0.014). The AQP2 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(6.52 ± 2.73 vs. 12.74 ± 5.18. P = 0.029;6.95 ± 3.10 vs. 12.74 ± 5.18, P = 0.047).The AQP2 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(6.95 ± 3.10 vs. 6.52 ± 2.73, P= 1.000).③The AQP7 protein expression in the rat cochlear lateral wall of EH group was significantly increased when compared with the blank group(30.32 ± 6.39 vs 16.64 ± 3.21, P=0.000). The AQP7 protein expression in the rat cochlear lateral wall of EH + tolvaptan group and EH + EA group were all lower than that of the EH group(18.32 ± 2.45 vs.30.32 ± 6.39, P= 0.001;19.54 ± 4.61 vs. 30.32 ± 6.39, P= 0.003). The AQP7 protein expression in the rat cochlear lateral wall of EH + EA group was not different from that in the EH + tolvaptan group(19.54 ±4.61 vs. 18.32 ± 2.45, P= 1.000).Conclusions: These results indicate that repeated EA stimulation exerted the same effects as tolvaptan application on AQPs levels and subsequent aquaretic effects. And dehydrating effect of EA on the inner ear might be associated with its down-regulation of both AQP2 and AQP7 protein expression, thereby provide a potential molecular mechanism involved in the treatment of Meniere's disease by EA.
文摘OBJECTIVE:To investigate whether Hetong decoction(和通汤,HTT)alleviates constipation via regulating AQPs expression.METHODS:Constipation in rats was induced by loperamide,and rats were randomly assigned into model(saline),HHT-low(95 g/kg),HTT-medium(190 g/kg),HTT-high(380 g/kg)and positive control(mosapride)groups.Then the defecation function,the concentration of serum arginine vasopressin(AVP)and cyclic adenosine monophosphate(cAMP),and the expression of AQP3 and AQP8 in colon tissues were assessed.NCM460 colon cells with AQP3 and AQP8 knockdown or overexpression were exposed to serum from rats that received low or high dose of HTT,followed by detection of AQP3 and AQP8 expression.RESULTS:The model group showed lower fecal weight and water content,weaker intestinal transit,higher serum concentration of AVP and cAMP,increased proximal and distal AQP8 expression,increased proximal but decreased distal AQP3 expression.However,these trends were reversed in both the HTT group(low,medium and high dose)and the positive control group.In NCM460 cells,HTT dose-dependently stabilized AQP3 and AQP8 expression under AQP3/8 plasmid interference or overexpression.CONCLUSIONS:HTT relieves constipation in rats through regulating AQP3 and AQP8 expression.
基金the European Commission(H2020-MSCA-IF-79212)the Ministry of Science,Innovation and Universities,Spain(Grants:RYC-2014-15581,AGL2016–81890-REDT,AGL2017–88329-R and FJCI-2017-31689)the Regional Government of Catalonia,Spain(2017-SGR-1229).
文摘Background:Aquaporins(AQPs)are a family of transmembrane water channels that includes orthodox AQPs,aquaglyceroporins(GLPs)and super AQPs.AQP3,AQP7,AQP9 and AQP11 have been identified in boar sperm,and they are crucial for sperm maturation and osmoregulation.Water exchange is an important event in cryopreservation,which is the most efficient method for long-term storage of sperm.However,the freezethaw process leads to sperm damage and a loss of fertilizing potential.Assuming that the quality of frozenthawed sperm partially depends on the regulation of osmolality variations during this process,AQPs might play a crucial role in boar semen freezability.In this context,the aim of this study was to unravel the functional relevance of the different groups of AQPs for boar sperm cryotolerance through three different inhibitors.Results:Inhibition of different groups of AQPs was found to have different effects on boar sperm cryotolerance.Whereas the use of 1,3-propanediol(PDO),an inhibitor of orthodox AQPs and GLPs,decreased total motility(P<0.05),it increased post-thaw sperm viability,lowered membrane lipid disorder and increased mitochondrial membrane potential(MMP)(P<0.05).When acetazolamide(AC)was used as an inhibitor of orthodox AQPs,the effects on post-thaw sperm quality were restricted to a mild increase in MMP in the presence of the intermediate concentration at 30 min post-thaw and an increase in superoxide levels(P<0.05).Finally,the addition of phloretin(PHL),a GLP inhibitor,had detrimental effects on post-thaw total and progressive sperm motilities,viability and lipid membrane disorder(P<0.05).Conclusions:The effects of the different inhibitors suggest that GLPs rather than orthodox AQPs are relevant for boar sperm freezability.Moreover,the positive effect of PDO on sperm quality suggests a cryoprotective role for this molecule.
基金supported by funding from Guangdong Natural Science Foundation (grants:S2012010009211,S2012010009538)Key Specialty Projects of Guangzhou Board of Health (grant:20121A021014)
文摘Rotavirus diarrhea is a major worldwide cause of infantile gastroenteritis; however, the mechanism responsible for intestinal fluid loss remains unclear. Water transfer across the intestinal epithelial membrane seems to occur because of aquaporins(AQPs). Accumulating evidence indicates that alterations in AQPs may play an important role in pathogenesis. Here, we focus on changes in AQPs in a mouse model of rotavirus diarrhea. In the present study, 32 of 35 mice developed diarrhea and mild dehydration within 24 hours after infection with rotavirus strain SA11. Intestinal epithelial cells demonstrated cytoplasmic vacuolation, malaligned villi, and atrophy. AQP1 expression was significantly attenuated in the ileum and colon in comparison with controls; likewise, AQP4 and-8 protein expression were significantly decreased in the colon of rotavirus diarrhea-infected mice. In contrast, AQP3 protein expression was significantly increased in the colon of rotavirus-infected mice in comparison with controls. These results indicate that rotavirus diarrhea is associated with the downregulation of AQP1,-4, and-8 expression. Therefore, AQPs play an important role in rotavirus diarrhea.
基金Grant PICT 05-31670(R.A.Marinelli) from Agencia Nacional de Promoción Científica y Tecnológicaby Grant PIP 6440 from Consejo Nacional de Investigaciones Científicas y Técnicas
文摘This review focuses on current knowledge on hepato-cyte aquaporins(AQPs)and their significance in bile formation and cholestasis.Canalicular bile secretion results from a combined interaction of several solute transporters and AQP water channels that facilitate water flow in response to the osmotic gradients created. During choleresis,hepatocytes rapidly increase their canalicular membrane water permeability by modulating the abundance of AQP8.The question was raised as to whether the opposite process,i.e.a decreased canalicular AQP8 expression would contribute to the development of cholestasis.Studies in several experimental models of cholestasis,such as extrahepatic obstructive cholestasis,estrogen-induced cholestasis, and sepsis-induced cholestasis demonstrated that the protein expression of hepatocyte AQP8 was impaired. In addition,biophysical studies in canalicular plasma membranes revealed decreased water permeability associated with AQP8 protein downregulation.The combined alteration in hepatocyte solute transporters and AQP8 would hamper the efficient coupling of osmotic gradients and canalicular water flow.Thus cholestasis may result from a mutual occurrence of impaired solute transport and decreased water permeability.
基金Supported by Science and Technology Commission of Shanghai,No.13ZR1406700 and No.13DZ1930908
文摘AIM: To investigate whether the regulation of aquaporin 3 (AQP3) and AQP9 induced by Auphen and dibutyryl cAMP (dbcAMP) inhibits hepatic tumorigenesis.METHODS: Expression of AQP3 and AQP9 was detected by Western blot, immunohistochemistry (IHC), and RT-PCR in HCC samples and paired non-cancerous liver tissue samples from 30 hepatocellular carcinoma (HCC) patients. A xenograft tumor model was used in vivo. Nine nude mice were divided into control, Auphen-treated, and dbcAMP-treated groups (n = 3 for each group). AQP3 and AQP9 protein expression after induction of xenograft tumors was detected by IHC and mRNA by RT-PCR analysis. The terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay and histological evaluation were used to detect apoptosis of tumor cells, and the concentration of serum α-fetoprotein (AFP) was measured using RT-PCR and an ELISA kit.RESULTS: The volumes and weights of tumors decreased significantly in the Auphen- and dbcAMP-treated mice compared with the control mice (P < 0.01). The levels of AQP3 were significantly lower in the Auphen treatment group, and levels of AQP9 were significantly higher in thedbcAMP treatment mice than in the control mice (P < 0.01). The reduction of AQP3 by Auphen and increase of AQP9 by dbcAMP in nude mice suppressed tumor growth of HCC, which resulted in reduced AFP levels in serum and tissues, and apoptosis of tumor cells in the Auphen- and dbcAMP-treated mice, when compared with control mice (P < 0.01). Compared with para-carcinoma tissues, AQP3 expression increased in tumor tissues whereas the expression of AQP9 decreased. By correlating clinicopathological and expression levels, we demonstrated that the expression of AQP3 and AQP9 was correlated with clinical progression of HCC and disease outcomes.CONCLUSION: AQP3 increases in HCC while AQP9 decreases. Regulation of AQP3 and AQP9 expression by Auphen and dbcAMP inhibits the development and growth of HCC.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(2020A1515111101,2022A1515110431).
文摘Plasma membrane intrinsic proteins(PIPs)are conserved plant aquaporins that transport small molecules across the plasma membrane to trigger instant stress responses and maintain cellular homeostasis under biotic and abiotic stress.To elucidate their roles in plant immunity to pathogen attack,we characterized the expression patterns,subcellular localizations,and H_(2)O_(2)-transport ability of 11 OsPIPs in rice(Oryza sativa),and identified OsPIP2;6 as necessary for rice disease resistance.OsPIP2;6 resides on the plasma membrane and facilitates cytoplasmic import of the immune signaling molecule H_(2)O_(2).Knockout of OsPIP2;6 increases rice susceptibility to Magnaporthe oryzae,indicating a positive function in plant immunity.OsPIP2;6 interacts with OsPIP2;2,which has been reported to increase rice resistance to pathogens via H_(2)O_(2)transport.Our findings suggest that OsPIP2;6 cooperates with OsPIP2;2 as a defense signal transporter complex during plant–pathogen interaction.
基金supported by the National Key Research and Development Program of China(2021YFD1201104-02)National Natural Science Foundation of China(32272048)to Xiaodong Ding。
文摘Compared to other organisms,plants have evolved a greater number of aquaporins with diverse substrates and functions to adapt to ever-changing environmental and internal stimuli for growth and development.Although aquaporins were initially identified as channels that allow water molecules to cross biological membranes,progress has been made in identifying various novel permeable substrates.Many studies have characterized the versatile physiological and biophysical functions of plant aquaporins.Here,we review the recent reports that highlight aquaporin-facilitated regulation of major physiological processes and stress tolerance throughout plant life cycles as well as the potential prospects and possibilities of applying aquaporins to improve agricultural productivity,food quality,environmental protection,and ecological conservation.
基金supported by the National Natural Science Foundation of China(Grant No.32460522,32372128,and 32201713)。
文摘Background Aquaporins(AQPs)are integral membrane proteins belonging to the major intrinsic protein(MIP)family,playing a crucial role in water transport,cell elongation,and stress responses.However,their evolutionary dynamics and functional roles in Gossypium species remain poorly characterized.Results In the present study,a total of 55,54,54,103,106,108,and 104 AQP genes were found in G.herbaceum,G.arboreum,G.raimondii,G.barbadense,G.tomentosum,G.mustelinum,and G.darwinii,respectively.Phylogenetic analysis classified them into five conserved subfamilies(PIP,TIP,NIP,SIP,and XIP),with 95 genes showing synteny across species and 17 displaying divergence,suggesting subgenome differentiation.Transcriptome analysis revealed that specific Gb AQP genes are involved in early salt stress responses and fiber development.Physiological assays demonstrated stronger salt tolerance in tetraploid cottons,particularly G.darwinii,compared with diploids.Co-expression network analysis linked AQPs to abiotic stress and fiber traits,and virus-induced gene silencing(VIGS)confirmed four AQP genes as critical for salt tolerance.Conclusion This study provides comprehensive insights into the evolution,expression,and functional roles of AQPs in cotton,identifying key candidate genes for improving salt tolerance and fiber quality in Gossypium species.
文摘Objective To investigate the effects and mechanisms of leonurine,an active component of Chinese motherwort(Leonurus japonicus Houtt.)which capable of activating blood circulation and eliminating water-dampness,on acute kidney injury(AKI)from the perspective of aquaporins(AQP).Methods Forty C57BL/6 mice were randomly divided into control group,AKI model group,and leonurine treatment groups(low-dose,medium-dose and high-dose),with 8 mice in each group.Except for thecontro1lgroup,miceini eachgroup were intraperitoneally injected with cisplatin to construct the AKImodel.Theintervention1groups were preadministered with leonurine for 3 days before modeling,and lasted for 7 consecutive days,with the dosages of 20,40,80O mg/kg,respectively.Control group and model groupp were gavaged with the equal volume of purified water.After 72 hours of modeling,the serum creatinine and urea nitrogen levels of all mice were examined to determine the optimal dose of leonurine.HE staining was performed to observe the pathological changes of kidneys.Immunohistochemistry and Western Blot were performed to detect the location and relative expression of the AQPs(AQP1-4)among different groups.Results Compared with the control group,the creatinine and urea nitrogen levels in model group were significantly increased(P<0.05).Renal pathological staining showed that,compared with the control group,the renal tubules in the model group had focal lesions,with some of the luminal surfaces of tubular cells with brush border detachment and cell flattening,whereas the lesions in the leonurine-treated group were significantly reduced.Compared with the control group,the protein expressions of AQP1,AQP2 and AQP4 in mice of the model group were significantly reduced(P<0.01,P<0.05).Compared with the model group,the creatinine and urea nitrogen levels reduced,and the protein expressions of AQP1 and AQP3 were elevated in the high-dose leonurine treatment group(P<0.01,P<O.05).Conclusion Leonurine can reduce creatinine and urea nitrogen levels and alleviate renal pathological injury of AKI,which may be associated with the regulation of AQPs.
基金supported by grants from the National Nat-ural Science Foundation of China(grant number 81101827).
文摘Aquaporins(AQPs)are highly conserved small transmembrane proteins,which are responsible for the water transport across the cell membrane.AQPs are abundantly expressed in numerous types of cells such as epithelial and endothelial cells.The expression of AQP-1,-3,-4,-5,-8 and-9 were found in the digestive system,where these six AQP isoforms serve essen-tial roles including mediating the transmembrane water transport and regulating the secretion of gastrointestinal(GI)fluids,consequently facilitating the digestion and absorption of GI con-tents.In addition,the expression levels of AQPs are controlled by various factors,and AQPs can stimulate numerous signaling pathways;however,aberrant expression of AQPs in the GI tracts are associated with the initiation and development of numerous diseases.Thus,this re-view provides an overview of the expression and functions of AQPs in the digestive system.
文摘With the support of the National Natural Science Foundation of China,Prof.Ye Qing’s laboratory at South China Botanical Garden,Chinese Academy of Sciences,reported differential regulatory mechanisms of AQPs in mediating plant water transport under osmotic or salt stresses,which was published in Plant,Cell and Environment(2014,doi:10.1111/pce.12319).
文摘Aquaporins are channels facilitating the diffusion of water and/or small uncharged solutes ecross biological membranes. They assemble as homotetramers but some of them also form heterotetramers, especially in plants. In Zea mays, aquaporins belonging to the plasma membrane intrinsic protein （PIP） subfamily are clustered into two groups, PIP1 and PIP2, which exhibit different water-channel activities when expressed in Xenopus oocytes. When PIP1 and PIP2 isoforms are co-expressed, they physically interact to modulate their subcellular localization and channel activity. Here, we demonstrated by affinity chromatography purification that, when co-expressed in Xenopus oocytes, the maize PIP1;2 and PIP2;5 isoforms assemble as homo- and heterodimers within heterotetramers. We built the 3D structure of such heterotetramers by comparative modeling on the basis of the spinach SoPIP2;1 X-ray structure and identified amino acid residues in the transmembrane domains which putatively interact at the interfaces between monomers. Their roles in the water-channel activity, subcellular localization, protein abundance, and physical interac- tion were investigated by mutagenesis. We highlighted single-residue substitutions that either inactivated PIP2;5 or activated PIP1;2 without affecting their interaction. Interestingly, the Phe220Ala mutation in the transmembrane domain 5 of PIP1 ;2 activated its water-channel activity and, at the same time, inactivated PIP2;5 within a heterotetramer. Altogether, these data contribute to a better understanding of the interaction mechanisms between PIP isoforms and the role of heterotetramerization on their water-channel activity.
基金supported by the Karen Elise Jensens Foundation,Lundbeck Foundation,AP Møller Foundation,and the National Natural Science Foundation of China(No.81370869).
文摘Background:Determining the expression and functions of aquaporins(AQPs)in the adult kidney has generated important information about the roles of this protein family in the renal regulation of water homeostasis.However,limited information describes the expression of AQPs in fetal kidneys,and most reports on fetal renal AQPs originate from animal studies.Although there are the maturation and regulation of the renalconcentrating mechanism,the ways in which changes in the expression of AQPs contribute to the formation of urine during the perinatal period remain unclear.Data sources:This review summarizes current knowledge about the spatial and temporal expression patterns of AQP1,AQP2,AQP3,and AQP4 in the fetal and postnatal kidneys in different animal species and in human beings.Results:AQP1 and AQP2 expression can be detected earlier in gestation in human beings and sheep compared with mice and rats.AQP1 expression is detected earlier in the proximal tubules than the expression of AQP2,AQP3,and AQP4 in the collecting ducts.Conclusion:Further studies investigating the regulation of AQPs during kidney development may provide insights into normal water-handling mechanisms and the pathophysiology of fetal kidneys,which may determine new directions for the clinical treatment of kidney diseases.
基金Supported by the National Natural Science Foundation of China (No.81173378)
文摘Aquapodns are a group of membrane proteins, which are known as the passages of water molecules transforming through the biological membrane lipid bilayer and distributing in almost all of the organs and tissues of living creatures. Aquaporins play important roles in maintaining water balance and internal environment stability. As a new entry point, aquaporins are involved in the researches on water metabolism, physiological regulation and pathological essence in viscera-state more and more widely in recent years. The literature on traditional Chinese medical studies, which related to aquaporins and were published in the last decade, was reviewed and the progress on application of aquaporin in Chinese medicine was summarized in this paper.
基金supported in part by the National Natural Science Foundation of China (nos.32172448 and 3177219)the Jiangsu Agricultural Science and Technology Innovation Fund (CX (21)2002)the National Key Research and Development Program (2021YFD1700803),and the USDA (HAW05032R).
文摘Neonicotinoids(NEOs),a large class of organic compounds,are a type of commonly used pesticide for crop protection.Their uptake and accumulation in plants are prerequisites for their intra-and intercellular move-ments,transformation,and function.Understanding the molecular mechanisms that underpin NEO uptake by plants is crucial for effective application,which remains elusive.Here,we demonstrate that NEOs enter plant cells primarily through the transmembrane symplastic pathway and accumulate mainly in the cytosol.Two plasma membrane intrinsic proteins discovered in Brassica rapa,BraPIP1;1 and BraPIP2;1,were found to encode aquaporins(AQPs)that are highly permeable to NEOs in different plant species and facilitate NEO subcellular diffusion and accumulation.Their conserved transport function was further demonstrated in Xenopus laevis oocyte and yeast assays.BraPIP1;1 and BraPIP2;1 gene knockouts and interaction as-says suggested that their proteins can form functional heterotetramers.Assessment of the potential of mean force indicated a negative correlation between NEO uptake and the energy barrier of BraPIP1;1 chan-nels.This study shows that AQPs transport organic compounds with greater osmolarity than previously thought,providing new insight into the molecular mechanisms of organic compound uptake and facilitating innovations in systemic pesticides.
文摘Aquaporins are water channel proteins that mediate the fine-tuning of cell membrane water permeability during development or in response to environmental stresses. The present work focuses on the oxidative stress-induced redistribution of plasma membrane intrinsic protein （PIP） aquaporins from the plasma membrane （PM） to intracellular membranes. This process was investigated in the Arabidopsis root. Su- crose density gradient centrifugation showed that exposure of roots to 0.5 mM H2O2 induces significant depletion in PM fractions of several abundant PIP homologs after 15 rain. Analyses by single-particle tracking and fluorescence correlative spectroscopy showed that, in the PM of epidermal cells, H2O2 treat- ment induces an increase in lateral motion and a reduction in the density of a fluorescently tagged form of the prototypal AtPIP2;1 isoform, respectively. Co-expression analyses of AtPIP2;1 with endomembrane markers revealed that H2O2 triggers AtPIP2;1 accumulation in the late endosomal compartments. Life- time analyses established that the high stability of PIPs was maintained under oxidative stress conditions, suggesting that H2O2 triggers a mechanism for intracellular sequestration of PM aquaporins without further degradation. In addition to information on cellular regulation of aquaporins, this study provides novel and complementary insights into the dynamic remodeling of plant internal membranes during oxida- tive stress responses.
