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1.
Int J Nanomedicine ; 15: 8495-8506, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33154639

RESUMO

Objective: Traumatic brain injury (TBI) is a serious health problem with few available treatment options. Rh-erythropoietin (rh-EPO) is a potential therapeutic drug for TBI, but it cannot cross the blood-brain barrier (BBB) directly. In this regard, a novel strategy to deliver rh-EPO for enhanced TBI treatment is via the development of Tween 80 modified albumin nanoparticles using electrostatic spray technology. Methods: The rh-EPO loaded Tween 80 modified albumin nanoparticles (rh-EPO-Tw-ABNPs) were prepared by electrostatic spray technology, while the process parameters were optimized via a single factor design. Investigation of physicochemical properties, bioactivity and stability of rh-EPO-Tw-ABNPs was carried out. The in vitro release and biocompatibility with nerve cells were also analyzed. The in vivo brain targeting efficiency, brain edema relieving effect and the expression of aquaporin 4 (AQP4) and glial fibrillary acidic protein (GFAP) in the brain were evaluated in TBI model rats. Results: The particle size of optimal rh-EPO-Tw-ABNPs was about 438 ± 45 nm, with a zeta potential of -25.42 ± 0.8 mv. The average drug loading ratio of rh-EPO-Tw-ABNPs was 21.3± 3.7 IU/mg with a relative bioactivity of 91.6 ± 4.1%. The in vitro release of rh-EPO from the nanoparticles was rather slow, while neither the blank Tw-ABNPs nor rh-EPO-Tw-ABNPs exhibited toxicity on the microglia cells. Furthermore, in vivo experiments indicated that the rh-EPO-Tw-ABNPs could enhance the distribution of EPO in the brain and relieve brain edema more effectively. Moreover, compared with an rh-EPO injection, the rh-EPO-Tw-ABNPs could increase the AQP4 level but reduced GFAP expression in the brain with more efficiency. Conclusion: The rh-EPO-Tw-ABNPs could enhance the transport of rh-EPO into the brain with superior therapeutic effect for TBI.


Assuntos
Albuminas/química , Lesões Encefálicas Traumáticas/tratamento farmacológico , Eritropoetina/uso terapêutico , Nanopartículas/química , Proteínas Recombinantes/uso terapêutico , Animais , Aquaporina 4/metabolismo , Encéfalo/efeitos dos fármacos , Encéfalo/patologia , Edema Encefálico/tratamento farmacológico , Liberação Controlada de Fármacos , Eritropoetina/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Humanos , Masculino , Nanopartículas/ultraestrutura , Neurônios/patologia , Tamanho da Partícula , Ratos Sprague-Dawley , Proteínas Recombinantes/farmacologia , Reologia , Eletricidade Estática
2.
Nat Commun ; 11(1): 4411, 2020 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-32879313

RESUMO

The glymphatic system is a network of perivascular spaces that promotes movement of cerebrospinal fluid (CSF) into the brain and clearance of metabolic waste. This fluid transport system is supported by the water channel aquaporin-4 (AQP4) localized to vascular endfeet of astrocytes. The glymphatic system is more effective during sleep, but whether sleep timing promotes glymphatic function remains unknown. We here show glymphatic influx and clearance exhibit endogenous, circadian rhythms peaking during the mid-rest phase of mice. Drainage of CSF from the cisterna magna to the lymph nodes exhibits daily variation opposite to glymphatic influx, suggesting distribution of CSF throughout the animal depends on time-of-day. The perivascular polarization of AQP4 is highest during the rest phase and loss of AQP4 eliminates the day-night difference in both glymphatic influx and drainage to the lymph nodes. We conclude that CSF distribution is under circadian control and that AQP4 supports this rhythm.


Assuntos
Aquaporina 4/metabolismo , Líquido Cefalorraquidiano/metabolismo , Ritmo Circadiano/fisiologia , Sistema Glinfático/metabolismo , Animais , Astrócitos/metabolismo , Encéfalo/metabolismo , Cisterna Magna/metabolismo , Linfonodos/metabolismo , Camundongos
3.
Artigo em Chinês | MEDLINE | ID: mdl-32746587

RESUMO

Critical poisoning is a critical illness. Cerebral edema after poisoning is one of the important factors that cause the patient's condition to worsen and affect the prognosis of patients after acute brain injury. Aquaporin 4 (AQP-4) is an important member of the aquaporin family and is abundantly expressed in the central nervous system, playing a pivotal role in the formation of cerebral edema. Brain injury can cause the secretion of inflammatory transmitters, causing or aggravating cerebral edema. Tumor necrosis factor-alpha (TNF-α) has been confirmed to be most closely related to cerebral edema, and can participate in the formation and development of brain edema by regulating AQP-4.


Assuntos
Aquaporina 4/metabolismo , Edema Encefálico/metabolismo , Lesões Encefálicas , Fator de Necrose Tumoral alfa/metabolismo , Animais , Humanos , Ratos , Ratos Sprague-Dawley
4.
Bratisl Lek Listy ; 121(8): 600-604, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32726124

RESUMO

AIM: To investigate the changes of water content in brain tissue, the expression of AQP4mRNA after cerebral hemorrhage in rats, and the intervention effect of Protease activated receptor 1 inhibitor (PAR1 inhibitor) on both. METHODS: Establish sham operation group (Sham group), ICH group, ICH+PAR1 inhibitor high-dose group (PI(H)group), ICH+PAR1 inhibitor low-dose group (PI(L)group), 25 in each group. Neural dysfunction scores were performed at 1d, 3d, 7d, 14d, and 21d after surgery, and brain water content and AQP4mRNA content were measured. RESULTS: Results: The neurological dysfunction and cerebral edema of rats with cerebral hemorrhage reached the peak at 3 days after operation. With the increase of time, the water content and AQP4mRNA content in the PL(H)group were higher than those in the PI(L)group. The differences were statistically significant. CONCLUSIONS: Appropriate inhibition of PAR1 can alleviate cerebral edema around the hematoma and play a role in improving the function of nerve defects. The mechanism may be realized by down-regulating the expression of AQP4mRNA in brain tissue (Tab. 3, Fig. 3, Ref. 25).


Assuntos
Edema Encefálico , Hemorragia Cerebral , Receptor PAR-1 , Animais , Aquaporina 4/metabolismo , Encéfalo , Modelos Animais de Doenças , Hematoma , Ratos , Receptor PAR-1/metabolismo
5.
C R Biol ; 343(1): 89-99, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32720491

RESUMO

In the present study we hypothesize that aquaporin 4 (AQP4) expression in the chicken oviduct would change during a pause in egg laying that was induced by fasting. Accordingly, the aim of this investigation was to examine the AQP4 mRNA and protein expression, and immunolocalization in the chicken oviduct during the course of regression. The experiment was carried out on laying hens subjected to a pause in laying that was induced by food deprivation for 5 days. Control hens were fed ad libitum. The birds were sacrificed on day 6 of the experiment and all segments of the oviduct were isolated, including the infundibulum, magnum, isthmus, shell gland, and vagina. Subsequently, the gene and protein expressions of AQP4 in the tissues were tested by real-time PCR and Western blot, respectively. The relative mRNA expression of AQP4 was the highest in the infundibulum and vagina and the lowest, and least detectable, in the magnum. The level of AQP4 protein was the highest in the infundibulum and the lowest in the magnum. Fasting resulted in a decrease of the AQP4 mRNA expression (P<0.001) in the infundibulum, a decrease in protein abundance (P<0.01) in the shell gland, and an increase in protein level (P<0.001) in the vagina. Immunohistochemistry demonstrated tissue- and cell-dependent localization of AQP4 protein in the oviductal wall. The intensity of staining was as follows: the infundibulum > shell gland > vagina ≥ isthmus ≫ magnum. In the control hens, the immunoreactivity for AQP4 in the vagina was similar, whereas in other oviductal segments, the immunoreactivity was stronger when compared with the chickens subjected to a pause in laying. In summary, these findings suggest that the AQP4 is an essential protein involved in the regulation of water transport required to create a proper microenvironment for fertilization and egg formation in the hen oviduct.


Assuntos
Aquaporina 4/metabolismo , Galinhas/fisiologia , Privação de Alimentos , Animais , Galinhas/genética , Feminino , Humanos , Imuno-Histoquímica , Oviductos/fisiologia , Oviposição , RNA Mensageiro/genética
6.
PLoS One ; 15(5): e0229702, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32413082

RESUMO

The Glymphatic System (GS) has been proposed as a mechanism to clear brain tissue from waste. Its dysfunction might lead to several brain pathologies, including the Alzheimer's disease. A key component of the GS and brain tissue water circulation is the astrocyte which is regulated by acquaporin-4 (AQP4), a membrane-bound water channel on the astrocytic end-feet. Here we investigated the potential of diffusion MRI to monitor astrocyte activity in a mouse brain model through the inhibition of AQP4 channels with TGN-020. Upon TGN-020 injection, we observed a significant decrease in the Sindex, a diffusion marker of tissue microstructure, and a significant increase of the water diffusion coefficient (sADC) in cerebral cortex and hippocampus compared to saline injection. These results indicate the suitability of diffusion MRI to monitor astrocytic activity in vivo and non-invasively.


Assuntos
Aquaporina 4/metabolismo , Astrócitos/metabolismo , Encéfalo/efeitos dos fármacos , Niacinamida/análogos & derivados , Tiadiazóis/farmacologia , Animais , Aquaporina 4/antagonistas & inibidores , Astrócitos/efeitos dos fármacos , Encéfalo/citologia , Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Imagem de Difusão por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Niacinamida/farmacologia
7.
PLoS Biol ; 18(5): e3000623, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32369477

RESUMO

Cerebrospinal fluid (CSF) flow through the brain parenchyma is facilitated by the astrocytic water channel aquaporin 4 (AQP4). Homeostatically regulated electroencephalographic (EEG) slow waves are a hallmark of deep non-rapid eye movement (NREM) sleep and have been implicated in the regulation of parenchymal CSF flow and brain clearance. The human AQP4 gene harbors several single nucleotide polymorphisms (SNPs) associated with AQP4 expression, brain-water homeostasis, and neurodegenerative diseases. To date, their role in sleep-wake regulation is unknown. To investigate whether functional variants in AQP4 modulate human sleep, nocturnal EEG recordings and cognitive performance were investigated in 123 healthy participants genotyped for a common eight-SNP AQP4-haplotype. We show that this AQP4-haplotype is associated with distinct modulations of NREM slow wave energy, strongest in early sleep and mirrored by changes in sleepiness and reaction times during extended wakefulness. The study provides the first human evidence for a link between AQP4, deep NREM sleep, and cognitive consequences of prolonged wakefulness.


Assuntos
Aquaporina 4/genética , Sono de Ondas Lentas/genética , Aquaporina 4/metabolismo , Eletroencefalografia , Haplótipos , Voluntários Saudáveis , Homeostase , Humanos , Vigília
8.
Life Sci ; 251: 117638, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32251636

RESUMO

AIMS: Brain edema is a common threat to life in ischaemic brain injury. The NLRP3 inflammasome promotes the inflammatory injury after ischaemic stroke. Previous studies have shown that aquaporin-4 (AQP4) modulates brain water transport and endothelin-1 (ET-1) induces cerebral edema. However, the contribution of the NLRP3 inflammasome to regulation of brain edema and blood-brain barrier (BBB) disruption in cerebral ischaemia-reperfusion is elusive. The aim of this study is to investigate the effect of inhibition of the NLRP3 inflammasome by MCC950 on regulation of cerebral edema, BBB disruption and the expression of AQP4 and ET-1 in cerebral ischaemia-reperfusion. MAIN METHODS: The male C57BL/6 mice were used to establish the experimental transient middle cerebral artery occlusion (tMCAO) model. The mice were intraperitoneally injected with MCC950. Changes in NLRP3, IL-1ß, IL-18, the pyroptosis protein gasdermin D (GSDMD), brain water content, AQP4 and ET-1 in brain tissue were detected. KEY FINDINGS: MCC950 inhibited NLRP3 and GSDMD after tMCAO. MCC950 improved cerebral edema and alleviated the damage of BBB after tMCAO. The levels of AQP4 and ET-1 were decreased by MCC950. In addition, MCC950 regulated the distribution of AQP4 after tMCAO in mice. SIGNIFICANCE: The NLRP3 inflammasome facilitated brain edema and BBB disruption after cerebral ischaemia-reperfusion in mice, and NLRP3 inflammasome inhibition with MCC950 regulated the expression and distribution of AQP4 in the infarct area. Hence, the NLRP3 inflammasome is considered to be an important target for the treatment of brain edema in cerebral ischaemia-reperfusion, and MCC950 has potential value for ischaemic stroke treatment.


Assuntos
Edema Encefálico/tratamento farmacológico , Isquemia Encefálica/tratamento farmacológico , Furanos/farmacologia , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Acidente Vascular Cerebral/tratamento farmacológico , Sulfonamidas/farmacologia , Animais , Aquaporina 4/metabolismo , Barreira Hematoencefálica/metabolismo , Edema Encefálico/patologia , Isquemia Encefálica/patologia , Modelos Animais de Doenças , Furanos/administração & dosagem , Compostos Heterocíclicos de 4 ou mais Anéis , Inflamassomos/efeitos dos fármacos , Inflamassomos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Traumatismo por Reperfusão/tratamento farmacológico , Traumatismo por Reperfusão/patologia , Acidente Vascular Cerebral/patologia , Sulfonamidas/administração & dosagem , Sulfonas
9.
J Biomed Sci ; 27(1): 40, 2020 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-32138732

RESUMO

BACKGROUND: The present study aimed to verify whether long noncoding RNA (lncRNA) MALAT1 is involved in brain tissue damage induced by ischemia-reperfusion injury, and to explore the mechanism by which MALAT1 regulates aquaporin 4 (AQP4). METHODS: In this study, we established glucose deprivation (OGD)/reoxygenation (RX) astrocyte cell model and middle cerebral artery occlusion (MCAO)/reperfusion mouse model in vitro and in vivo. Then cell counting kit-8 assay, flow cytometry analysis, Triphenyltetrazolium chloride (TTC) staining, and western blotting were used to determine cell viability, cell apoptosis, cerebral infarction volume, and the abundance of AQP4, respectively. RESULTS: We found that the level of MALAT1 was significantly upregulated in both the MCAO/reperfusion model and OGD/RX model. Knockdown of MALAT1 increased cell viability and reduced cell apoptosis in MA-C cells, while an AQP4 siRNA combined with a siRNA targeting MALAT1 could not enhance this effect. Further experiments showed that MALAT1 positively regulated AQP4 expression via miR-145. The MALAT1 siRNA did not alleviate the exacerbation of damage after miR-145 inhibitor action. However, an miR-145 inhibitor reversed the protection effects of MALAT1, indicating that MALAT1 silencing protects against cerebral ischemia-reperfusion injury through miR-145. TTC staining showed that the infracted area of whole brain was significantly attenuated in treated with sh-MALAT1 group in vivo. CONCLUSION: Taken together, our study confirmed that MALAT1 promotes cerebral ischemia-reperfusion injury by affecting AQP4 expression through competitively binding miR-145, indicating that MALAT1 might be a new therapeutic target for treatment cerebral ischemic stroke.


Assuntos
Aquaporina 4/genética , Regulação da Expressão Gênica , Inativação Gênica , MicroRNAs/genética , RNA Longo não Codificante/genética , Traumatismo por Reperfusão/genética , Animais , Aquaporina 4/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , RNA Longo não Codificante/metabolismo , Regulação para Cima
10.
PLoS One ; 15(3): e0229274, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32160197

RESUMO

Despite many years of research efforts and clinical trials the prognosis of patients diagnosed with glioblastoma remains very poor. The oligodendrocyte transcription factor 2 (Olig2) was identified as a marker for glioma stem cells, which are believed to be responsible for glioma recurrence and therapy resistance. In this retrospective analysis we assessed the prognostic value of oligodendroglial and glioma stem cell markers in 113 IDH-wildtype glioblastomas. Immunohistochemical staining for Olig2, NogoA, AQP4 and Nestin was performed in combination with sequencing of IDH1 and IDH2 as well as promotor methylation analysis of the MGMT gene. Even though differences in overall survival according to Olig2 expression were observed, univariate and multivariate survival analysis did not reveal a firm significant prognostic impact of Olig2, NogoA, AQP4 or Nestin expression. Additionally, no differences in the expression of these markers depending on clinical status, age or gender were found. The established independent prognostic factors age<65, Karnofsky Performance Status> = 70 and methylated MGMT gene promoter were significant in the multivariate analysis. In conclusion expression of oligodendroglial and glioma stem cell markers do not have an independent prognostic effect in IDH-wildtype glioblastoma.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/mortalidade , Glioblastoma/genética , Glioblastoma/mortalidade , Isocitrato Desidrogenase/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Aquaporina 4/genética , Aquaporina 4/metabolismo , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/terapia , Feminino , Glioblastoma/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Recidiva Local de Neoplasia/diagnóstico , Nestina/genética , Nestina/metabolismo , Proteínas Nogo/genética , Proteínas Nogo/metabolismo , Fator de Transcrição 2 de Oligodendrócitos/genética , Fator de Transcrição 2 de Oligodendrócitos/metabolismo , Prognóstico , Regiões Promotoras Genéticas , Estudos Retrospectivos , Adulto Jovem
11.
J Neuropathol Exp Neurol ; 79(4): 419-429, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32167542

RESUMO

Gerstmann-Sträussler-Scheinker (GSS) disease with P102L mutation and familial Creutzfeldt-Jakob disease (CJD) with V180I mutation are 2 major hereditary prion diseases in Japan. GSS and some familial CJD [V180I] exhibit characteristic prion protein (PrP) plaques. Overexpression of the astrocytic water channel proteins aquaporin (AQP) 1 and AQP4 was recently reported in sporadic CJD. To clarify the pathological characteristics of AQP1 and AQP4 in prion disease patient brains with plaque-type deposition, we investigated 5 patients with GSS, 2 patients with CJD [V180I], and 2 age-matched control cases without neurological diseases using immunohistochemistry and double immunofluorescence methods. We demonstrated that there is the intense expression of AQP1 and AQP4 around prion plaques, especially in distal astrocytic processes deep inside these plaques. Similar results have been reported in the senile plaques and ghost tangles of Alzheimer disease brains and a protective role of AQP4 in which AQP4 is redistributed toward the plaques and works as a barrier against the deleterious effects of these plaques has been suggested. Our results, which show a similar clustering of AQPs around PrP plaques, therefore support the possibility that AQPs also have a protective role in plaque formation in prion diseases.


Assuntos
Aquaporina 1/metabolismo , Aquaporina 4/metabolismo , Astrócitos/patologia , Encéfalo/patologia , Síndrome de Creutzfeldt-Jakob/patologia , Doença de Gerstmann-Straussler-Scheinker/patologia , Proteínas Priônicas/metabolismo , Idoso , Idoso de 80 Anos ou mais , Astrócitos/metabolismo , Encéfalo/metabolismo , Síndrome de Creutzfeldt-Jakob/metabolismo , Feminino , Doença de Gerstmann-Straussler-Scheinker/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Agregação Patológica de Proteínas/metabolismo , Agregação Patológica de Proteínas/patologia , Substância Branca/metabolismo , Substância Branca/patologia
12.
Int J Mol Sci ; 21(3)2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32033173

RESUMO

The role exerted by Aquaporin 4 (AQP4) as a regulator of astrocyte immune functions has been poorly explored. A recent report demonstrates that under neuroinflammatory conditions, the expression of Aqp4 on murine astrocytes is mandatory for the effective control of acute inflammation in the central nervous system. Such an immunomodulatory function appears to be mediated by a promotion of the transforming growth factor beta 1 (Tgfb1) pathway. Here, these results are discussed in the context of neuromyelitis optica (NMO) and multiple sclerosis (MS) progressive forms. It is proposed that NMO and progressive MS might rely on opposite molecular mechanisms involving, in NMO, an acutely-defective AQP4/TGFB1 pathway and, in progressive MS, a chronically-stimulated AQP4/TGFB1 pathway. Data supporting the involvement of angiotensin II as a molecular link between AQP4 and TGFB1 are also reviewed.


Assuntos
Aquaporina 4/metabolismo , Astrócitos/metabolismo , Esclerose Múltipla/metabolismo , Neuromielite Óptica/metabolismo , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta1/metabolismo , Angiotensina II/metabolismo , Animais , Astrócitos/patologia , Progressão da Doença , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Esclerose Múltipla/patologia , Neuromielite Óptica/patologia
13.
Int J Mol Sci ; 21(3)2020 Feb 02.
Artigo em Inglês | MEDLINE | ID: mdl-32024231

RESUMO

Aquaporins (AQPs) are involved in hypoxia-induced angiogenesis and retinal damage. Bumetanide is a diuretic agent, Na+/K+/Cl- cotransporter (NKCC1), and AQP 1-4 inhibitor. We tested the hypothesis that early postnatal treatment with bumetanide suppresses biomarkers of angiogenesis and decreases severe retinopathy oxygen-induced retinopathy (OIR). Neonatal rats were exposed at birth (P0) to either (1) room air (RA); (2) hyperoxia (50% O2); or (3) intermittent hypoxia (IH) consisting of 50% O2 with brief, clustered episodes of 12% O2 from P0 to postnatal day 14 (P14), during which they were treated intraperitoneally (IP) with bumetanide (0.1 mg/kg/day) or an equivalent volume of saline, on P0-P2. Pups were examined at P14 or allowed to recover in RA from P14-P21. Retinal angiogenesis, morphometry, pathology, AQPs, and angiogenesis biomarkers were determined at P14 and P21. Bumetanide reduced vascular abnormalities associated with severe OIR. This was associated with reductions in AQP-4 and VEGF. Bumetanide suppressed sVEGFR-1 in the serum and vitreous fluid, but levels were increased in the ocular tissues during recovery. Similar responses were noted for IGF-I. In this model, early systemic bumetanide administration reduces severe OIR, the benefits of which appear to be mediated via suppression of AQP-4 and VEGF. Further studies are needed to determine whether bumetanide at the right doses may be considered a potential pharmacologic agent to treat retinal neovascularization.


Assuntos
Bumetanida/farmacologia , Modelos Animais de Doenças , Diuréticos/farmacologia , Neovascularização Patológica/prevenção & controle , Oxigênio/efeitos adversos , Neovascularização Retiniana/prevenção & controle , Retinopatia da Prematuridade/tratamento farmacológico , Animais , Animais Recém-Nascidos , Aquaporina 4/metabolismo , Feminino , Masculino , Neovascularização Patológica/etiologia , Neovascularização Patológica/patologia , Ratos , Ratos Sprague-Dawley , Neovascularização Retiniana/etiologia , Neovascularização Retiniana/patologia , Retinopatia da Prematuridade/etiologia , Retinopatia da Prematuridade/patologia , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
Int J Mol Sci ; 21(4)2020 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-32102323

RESUMO

Translational readthrough (TRT) of aquaporin-4 (AQP4) has remarkably expanded the importance of this new post-transcriptional mechanism, as well as the regulation potential of AQP4. The TRT isoform of AQP4, named AQP4ex, is central for both AQP4 polarization and water channel activity in the central nervous system (CNS). Here we evaluate the relevance of the TRT mechanism by analyzing whether AQP4ex is also expressed in peripheral tissues and whether the expression of AQP4ex is necessary for its polarized expression as it occurs in perivascular astrocyte processes. To this purpose, AQP4ex null mice were used, and analysis was performed by immunolocalization and immunoblot. The results demonstrate that AQP4ex is expressed in kidney, stomach, trachea and skeletal muscle with the same localization pattern as the canonical AQP4 isoforms. AQP4ex protein levels vary from 6% to about 13% of the total AQP4 protein levels in peripheral tissues. Immunogold electron microscopy experiments demonstrated the localization of AQP4ex at the astrocytic endfeet, and experiments conducted on AQP4ex null mice CNS confirmed that the expression of AQP4ex is necessary for anchoring of the perivascular AQP4. Without the readthrough isoform, AQP4 assemblies are mis-localized, being uniformly distributed on the astrocyte processes facing the neuropile. No alteration of AQP4 polarization was found in AQP4ex null kidney, stomach, trachea or skeletal muscle, suggesting that AQP4ex does not have a role for proper membrane localization of AQP4 in peripheral tissues. We conclude that a dual role for AQP4ex is limited to the CNS.


Assuntos
Aquaporina 4/genética , Astrócitos/metabolismo , Sistema Nervoso Central/metabolismo , Regulação da Expressão Gênica , Animais , Aquaporina 4/metabolismo , Astrócitos/ultraestrutura , Sistema Nervoso Central/ultraestrutura , Immunoblotting , Rim/metabolismo , Camundongos , Camundongos Knockout , Microscopia Imunoeletrônica , Músculo Esquelético/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estômago/química , Traqueia/metabolismo
15.
Nat Commun ; 11(1): 175, 2020 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924752

RESUMO

Challenges in drug development of neurological diseases remain mainly ascribed to the blood-brain barrier (BBB). Despite the valuable contribution of animal models to drug discovery, it remains difficult to conduct mechanistic studies on the barrier function and interactions with drugs at molecular and cellular levels. Here we present a microphysiological platform that recapitulates the key structure and function of the human BBB and enables 3D mapping of nanoparticle distributions in the vascular and perivascular regions. We demonstrate on-chip mimicry of the BBB structure and function by cellular interactions, key gene expressions, low permeability, and 3D astrocytic network with reduced reactive gliosis and polarized aquaporin-4 (AQP4) distribution. Moreover, our model precisely captures 3D nanoparticle distributions at cellular levels and demonstrates the distinct cellular uptakes and BBB penetrations through receptor-mediated transcytosis. Our BBB platform may present a complementary in vitro model to animal models for prescreening drug candidates for the treatment of neurological diseases.


Assuntos
Transporte Biológico/fisiologia , Engenharia Biomédica/métodos , Barreira Hematoencefálica/metabolismo , Dispositivos Lab-On-A-Chip , Nanopartículas/química , Nanotecnologia/métodos , Animais , Aquaporina 4/metabolismo , Astrócitos/metabolismo , Engenharia Biomédica/instrumentação , Técnicas de Cultura de Células/métodos , Sistemas de Liberação de Medicamentos , Descoberta de Drogas , Citometria de Fluxo , Expressão Gênica , Gliose , Humanos , Modelos Animais , Nanotecnologia/instrumentação , Permeabilidade , Transcitose
16.
Cell Prolif ; 53(1): e12732, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31746080

RESUMO

OBJECTIVES: Temozolomide (TMZ) is one of the most commonly used clinical drugs for glioblastoma (GBM) treatment, but its drug sensitivity needs to be improved. Gamabufotalin (CS-6), the primary component of the traditional Chinese medicine "ChanSu," was shown to have strong anti-cancer activity. However, more efforts should be directed towards reducing its toxicity or effective treatment doses. METHODS: Target fishing experiment, Western blotting, PCR, confocal immunofluorescence and molecular cloning techniques were performed to search for possible downstream signalling pathways. In addition, GBM xenografts were used to further determine the potential molecular mechanisms of the synergistic effects of CS-6 and TMZ in vivo. RESULTS: Mechanistic research revealed a negative feedback loop between ATP1A3 and AQP4 through which CS-6 inhibited GBM growth and mediated the synergistic treatment effect of CS-6 and TMZ. In addition, by mutating potential amino acid residues of ATP1A3, which were predicted by modelling and docking to interact with CS-6, we demonstrated that abrogating hydrogen bonding of the amino acid Thr794 interferes with the activation of ATP1A3 by CS-6 and that the Thr794Ala mutation directly affects the synergistic treatment efficacy of CS-6 and TMZ. CONCLUSIONS: As the main potential target of CS-6, ATP1A3 activation critically depends on the hydrogen bonding of Thr794 with CS-6. The combination of CS-6 and TMZ could significantly reduce the therapeutic doses and promote the anti-cancer efficacy of CS-6/TMZ monotherapy.


Assuntos
Aquaporina 4/metabolismo , Bufanolídeos/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma/tratamento farmacológico , Proteínas de Neoplasias/biossíntese , ATPase Trocadora de Sódio-Potássio/biossíntese , Temozolomida/farmacologia , Animais , Aquaporina 4/genética , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/genética , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Camundongos , Proteínas de Neoplasias/genética , ATPase Trocadora de Sódio-Potássio/genética , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Brain Pathol ; 30(1): 13-25, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31587392

RESUMO

Neuromyelitis optica spectrum disorders (NMOSD) is a heterogeneous group of neuroinflammatory conditions associated with demyelination primarily in spinal cord and optic nerve, and to a lesser extent in brain. Most NMOSD patients are seropositive for IgG autoantibodies against aquaporin-4 (AQP4-IgG), the principal water channel in astrocytes. There has been interest in establishing experimental animal models of seropositive NMOSD (herein referred to as NMO) in order to elucidate NMO pathogenesis mechanisms and to evaluate drug candidates. An important outcome of early NMO animal models was evidence for a pathogenic role of AQP4-IgG. However, available animal models of NMO, based largely on passive transfer to rodents of AQP4-IgG or transfer of AQP4-sensitized T cells, often together with pro-inflammatory maneuvers, only partially recapitulate the clinical and pathological features of human NMO, and are inherently biased toward humoral or cellular immune mechanisms. This review summarizes current progress and shortcomings in experimental animal models of seropositive NMOSD, and opines on the import of advancing animal models.


Assuntos
Aquaporina 4/imunologia , Neuromielite Óptica/metabolismo , Neuromielite Óptica/patologia , Animais , Aquaporina 4/metabolismo , Aquaporina 4/fisiologia , Astrócitos/patologia , Autoanticorpos/imunologia , Encéfalo/patologia , Modelos Animais de Doenças , Humanos , Imunoglobulina G/imunologia , Neuromielite Óptica/genética , Nervo Óptico/metabolismo , Nervo Óptico/patologia , Medula Espinal/patologia
18.
Intern Med ; 59(1): 55-60, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31484905

RESUMO

Objective Oryeongsan (Goreisan), a formula composed of five herbal medicines, has long been used to treat impairments of the regulation of body fluid homeostasis. Goreisan has been revealed to have anti-inflammatory actions and inhibit a water channel, the aquaporin (AQP). We herein report the therapeutic effect of Goreisan on experimental autoimmune encephalomyelitis (EAE in, an animal model of inflammatory demyelinating diseases. Materials and Methods EAE mice immunized with MOG35-55 peptide were divided into Goreisan- and sham-treated groups. The clinical EAE score and histopathological finding of the central nervous system (CNS) were analyzed. For the proliferation assay, prepared spleen cells from immunized mice were cultured and analyzed for the [3H]-thymidine uptake and cytokine concentrations of the culture supernatant. The relative quantification of AQP4 mRNA in the CNS of EAE mice was analyzed quantitatively. Results The EAE score of the Goreisan-treated mice was significantly lower than that of the sham-treated mice. The CD4-positive cell number in the CNS of Goreisan-treated mice was lower than that of sham-treated mice. In the recall response to MOG35-55 peptide, the cell proliferation did not differ markedly between the spleen cells from Goreisan- and sham-treated mice. Furthermore, Goreisan decreased the mRNA level of AQP4 in the spinal cord during EAE. Conclusion Goreisan prevented the disease activity of EAE by inhibiting the migration of pathogenic cells into the CNS by suppressing the AQP4 expression in the CNS. Goreisan may have a therapeutic effect on inflammatory demyelinating diseases.


Assuntos
Aquaporina 4/efeitos dos fármacos , Linfócitos T CD4-Positivos/efeitos dos fármacos , Citocinas/efeitos dos fármacos , Medicamentos de Ervas Chinesas/farmacologia , Encefalomielite Autoimune Experimental/metabolismo , Medula Espinal/efeitos dos fármacos , Animais , Aquaporina 4/genética , Aquaporina 4/metabolismo , Proliferação de Células , Sistema Nervoso Central/efeitos dos fármacos , Sistema Nervoso Central/metabolismo , Sistema Nervoso Central/patologia , Citocinas/metabolismo , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/patologia , Feminino , Humanos , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Medula Espinal/metabolismo , Medula Espinal/patologia
19.
Int J Mol Sci ; 20(23)2019 Nov 29.
Artigo em Inglês | MEDLINE | ID: mdl-31795399

RESUMO

Status epilepticus (a prolonged seizure activity, SE) differently affects vasogenic edema formation and dystrophin-aquaporin 4 (AQP4) expressions between the rat hippocampus and the piriform cortex (PC). In the present study, we explored whether the 67-kDa laminin receptor (LR) expression was relevant to the regional specific susceptibility of vasogenic edema at 3 days after SE. In spite of no difference in expression levels of 67-kDa LR, dystrophin, and AQP4 under physiological conditions, SE-induced serum extravasation was more severe in the PC than the hippocampus. Western blots demonstrated that SE reduced expression levels of 67-kDa LR, dystrophin, and AQP4 in the PC, but not in the hippocampus proper. Immunofluorescent studies revealed that SE increased 67-kDa LR expression in reactive CA1 astrocyte, but reduced it in the PC and the molecular layer of the dentate gyrus due to massive astroglial loss. Furthermore, SE decreased expressions of endothelial 67-kDa LR and SMI-71 (endothelial brain barrier antigen) in these regions. The 67-kDa LR neutralization evoked serum extravasation in these regions of normal animals without astroglial loss. Similar to SE, 67-kDa LR neutralization also reduced dystrophin-AQP4 expressions in the PC more than the total hippocampus. Furthermore, 67-kDa LR IgG infusion increased phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), but not c-Jun N-terminal kinase, independent of phosphoprotein enriched in astrocytes of 15 kDa (PEA15) activity. Co-treatment of U0126 (an ERK1/2 inhibitor) alleviated vasogenic edema formation and the reduced dystrophin-AQP4 expressions induced by 67-kDa LR neutralization. The 67-kDa LR IgG infusion also increased the susceptibility to SE induction. Therefore, our findings suggested that the cellular specific alterations in 67-kDa LR expression might be involved in the severity of SE-induced vasogenic edema formation in regional specific manners, which might affect the susceptibility to SE induction.


Assuntos
Astrócitos/patologia , Barreira Hematoencefálica/patologia , Células Endoteliais/patologia , Receptores de Laminina/análise , Estado Epiléptico/patologia , Animais , Aquaporina 4/análise , Aquaporina 4/metabolismo , Astrócitos/metabolismo , Barreira Hematoencefálica/metabolismo , Permeabilidade Capilar , Distrofina/análise , Distrofina/metabolismo , Células Endoteliais/metabolismo , Masculino , Ratos Sprague-Dawley , Receptores de Laminina/metabolismo , Estado Epiléptico/metabolismo
20.
Xi Bao Yu Fen Zi Mian Yi Xue Za Zhi ; 35(9): 823-827, 2019 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-31750825

RESUMO

Objective To study the characteristics of the expression of aquaporin-4 (AQP4) in the brains and astrocytes of rats with thermoplegia. Methods Sixty healthy male Sprague-Dawley rats weighing (250±30) g were randomly divided into control group and model group. The quiet exposure method with high temperature (40DegreesCelsius) and high humidity (70%) was used to make a typical rat model of thermoplegia to monitor rectal temperature and record onset time every 10 minutes. When the temperature of stressed rats reached 42.5 DegreesCelsius, it was regarded as onset time of the disease. The rats in both groups were placed at 26DegreesCelsius with humidity 60% later. After 5-hour observation and their behavior evaluation, the rats were killed and their brain tissues were taken for measuring the water content of the tissues. The astrocytes of the rats were cultured at 37DegreesCelsius and 41DegreesCelsius. AQP4 mRNA and protein expression were detected by reverse-transcription PCR and Western blot analysis. Results Compared with the control group, the expression of AQP4 mRNA and protein were significantly lower in the model group than in the control group. Conclusion High temperature may lead to the destruction of blood-brain barrier and the down-regulation of AQP4 mRNA and protein expression in experimental rats, which can induce the occurrence and development of cerebral edema in experimental rats.


Assuntos
Aquaporina 4/metabolismo , Barreira Hematoencefálica , Edema Encefálico/patologia , Golpe de Calor/patologia , Animais , Astrócitos , Encéfalo/metabolismo , Temperatura Alta , Masculino , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley
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