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1.
Am J Transplant ; 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-39002782

RESUMO

A transplant of a portion of the bladder with an en bloc kidney from a 2-year-old donor was previously reported in a 12-month-old girl due to her extremely small bladder. Bilateral kidneys were transplanted en bloc with their ureters connected to a patch of the donor bladder (bladder patch technique). The long-term outcomes and complications of this technique have not been documented. Here, we report a long-term, 17-year follow-up of this patient with an evaluation of whole bladder functions at 18 years of age. The patient has had no episodes of urinary tract infections. Cystoscopy showed a viable transplanted bladder with a well-perfused mucosa. We observed that the native bladder has stretched over time, forming more than half of the bladder wall. Urodynamic studies showed preserved bladder compliance at 43 mL/cmH2O, and native bladder contractility was preserved. Prolonged voiding time and postvoid residual urine were also observed. These findings were suggestive of detrusor underactivity. No reflux across the donor ureterovesical junctions was observed. The recipient was instructed to continue timed voiding and double voiding to empty the bladder. In conclusion, en bloc kidney transplantation with a bladder patch is a feasible and safe option for kidney transplant recipients with a small bladder capacity.

2.
Int J Mol Sci ; 25(14)2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-39063222

RESUMO

Migraine is a complex disorder characterized by episodes of moderate-to-severe, often unilateral headaches and generally accompanied by nausea, vomiting, and increased sensitivity to light (photophobia), sound (phonophobia), and smell (hyperosmia). Photophobia is considered the most bothersome symptom of migraine attacks. Although the underlying mechanism remains unclear, the intrinsically photosensitive retinal ganglion cells (ipRGCs) are considered to be involved in photophobia associated with migraine. In this study, we investigated the association between the sensitivity of ipRGCs and migraines and cortical spreading depression (CSD), which may trigger migraine attacks. The pupillary responses closely associated with the function of ipRGCs in patients with migraine who were irradiated with lights were evaluated. Blue (486 nm) light irradiation elicited a response from ipRGCs; however, red light (560 nm) had no such effect. Melanopsin, a photosensitive protein, phototransduces in ipRGCs following blue light stimulation. Hypersensitivity of ipRGCs was observed in patients with migraine. CSD was more easily induced with blue light than with incandescent light using a mouse CSD model. Moreover, CSD was suppressed, even in the presence of blue light, after injecting opsinamide, a melanopsin inhibitor. The hypersensitivity of ipRGCs in patients with migraine may induce CSD, resulting in migraine attacks.


Assuntos
Depressão Alastrante da Atividade Elétrica Cortical , Transtornos de Enxaqueca , Células Ganglionares da Retina , Opsinas de Bastonetes , Transtornos de Enxaqueca/metabolismo , Animais , Células Ganglionares da Retina/patologia , Humanos , Camundongos , Masculino , Feminino , Adulto , Opsinas de Bastonetes/metabolismo , Luz/efeitos adversos , Fotofobia/etiologia , Pessoa de Meia-Idade , Modelos Animais de Doenças , Camundongos Endogâmicos C57BL
3.
Genet Med ; 25(2): 100335, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36507973

RESUMO

The U.S. Food and Drug Administration recently approved lonafarnib as the first treatment for Hutchinson-Gilford progeria syndrome (HGPS) and processing-deficient progeroid laminopathies. This approval was primarily based on a comparison of patients with HGPS treated with lonafarnib in 2 open-label trials with an untreated patient cohort. With up to 11 years of follow-up, it was found that the lonafarnib treated patients with HGPS had a survival benefit of 2.5 years compared with the untreated patients with HGPS. This large treatment effect on the objective endpoint of mortality using a well-matched comparator group mitigated potential sources of bias and together with other evidence, established compelling evidence of a drug effect with benefits that outweighed the risks. This approval is an example of U.S. Food and Drug Administration's regulatory flexibility for a rare disease while ensuring that standards for drug approval are met.


Assuntos
Progéria , Estados Unidos , Humanos , Progéria/tratamento farmacológico , Progéria/genética , Lamina Tipo A/genética , Piperidinas/uso terapêutico , Piridinas/uso terapêutico
4.
Biol Pharm Bull ; 46(8): 1049-1056, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37532556

RESUMO

Bortezomib, an anticancer drug for multiple myeloma and mantle cell lymphoma, causes severe adverse events and leads to peripheral neuropathy. The associated neuropathy limits the use of bortezomib and could lead to discontinuation of the treatment; therefore, effective intervention is crucial. In the present study, we statistically searched for a drug that could alleviate bortezomib-induced peripheral neuropathy using adverse event self-reports. We observed that specific inhibitors of the mechanistic target of rapamycin (mTOR) lowered the incidence of bortezomib-induced peripheral neuropathy. These findings were experimentally validated in mice, which exhibited long-lasting mechanical hypersensitivity after repeated bortezomib treatment. This effect was inhibited for hours after a systemic injection with rapamycin or everolimus in a dose-dependent manner. Bortezomib-induced allodynia was accompanied by the activation of spinal astrocytes, and intrathecal injection of mTOR inhibitors or an inhibitor of ribosomal protein S6 kinase 1, a downstream target of mTOR, exhibited considerable analgesic effects in a dose-dependent manner. These results suggest that mTOR inhibitors, which are readily available to patients prescribed bortezomib, are one of the most effective therapeutics for bortezomib-induced peripheral neuropathy.


Assuntos
Antineoplásicos , Bortezomib , Doenças do Sistema Nervoso Periférico , Animais , Camundongos , Antineoplásicos/efeitos adversos , Bortezomib/efeitos adversos , Inibidores de MTOR , Doenças do Sistema Nervoso Periférico/induzido quimicamente , Doenças do Sistema Nervoso Periférico/tratamento farmacológico , Doenças do Sistema Nervoso Periférico/metabolismo , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
5.
BMC Biol ; 19(1): 43, 2021 03 11.
Artigo em Inglês | MEDLINE | ID: mdl-33706787

RESUMO

BACKGROUND: Amyloids are ordered, insoluble protein aggregates, characterized by a cross-ß sheet quaternary structure in which molecules in a ß-strand conformation are stacked along the filament axis via intermolecular interactions. While amyloids are typically associated with pathological conditions, functional amyloids have also been identified and are present in a wide variety of organisms ranging from bacteria to humans. The cytoplasmic polyadenylation element-binding (CPEB) prion-like protein is an mRNA-binding translation regulator, whose neuronal isoforms undergo activity-dependent aggregation, a process that has emerged as a plausible biochemical substrate for memory maintenance. CPEB aggregation is driven by prion-like domains (PLD) that are divergent in sequence across species, and it remains unknown whether such divergent PLDs follow a similar aggregating assembly pathway. Here, we describe the amyloid-like features of the neuronal Aplysia CPEB (ApCPEB) PLD and compare them to those of the Drosophila ortholog, Orb2 PLD. RESULTS: Using in vitro single-molecule and bulk biophysical methods, we find transient oligomers and mature amyloid-like filaments that suggest similarities in the late stages of the assembly pathway for both ApCPEB and Orb2 PLDs. However, while prior to aggregation the Orb2 PLD monomer remains mainly as a random coil in solution, ApCPEB PLD adopts a diversity of conformations comprising α-helical structures that evolve to coiled-coil species, indicating structural differences at the beginning of their amyloid assembly pathways. CONCLUSION: Our results indicate that divergent PLDs of CPEB proteins from different species retain the ability to form a generic amyloid-like fold through different assembly mechanisms.


Assuntos
Amiloide/metabolismo , Aplysia/metabolismo , Príons/metabolismo , Animais , Aplysia/química , Poliadenilação , Príons/química
6.
Int J Mol Sci ; 23(3)2022 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-35163450

RESUMO

α-Synuclein (αSyn) plays a major role in the pathogenesis of Parkinson's disease (PD), which is the second most common neurodegenerative disease after Alzheimer's disease. The accumulation of αSyn is a pathological hallmark of PD, and mutations in the SNCA gene encoding αSyn cause familial forms of PD. Moreover, the ectopic expression of αSyn has been demonstrated to mimic several key aspects of PD in experimental model systems. Among the various model systems, Drosophila melanogaster has several advantages for modeling human neurodegenerative diseases. Drosophila has a well-defined nervous system, and numerous tools have been established for its genetic analyses. The rapid generation cycle and short lifespan of Drosophila renders them suitable for high-throughput analyses. PD model flies expressing αSyn have contributed to our understanding of the roles of various disease-associated factors, including genetic and nongenetic factors, in the pathogenesis of PD. In this review, we summarize the molecular pathomechanisms revealed to date using αSyn-expressing Drosophila models of PD, and discuss the possibilities of using these models to demonstrate the biological significance of disease-associated factors.


Assuntos
Mutação , Doença de Parkinson/genética , alfa-Sinucleína/genética , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Drosophila melanogaster/genética , Drosophila melanogaster/crescimento & desenvolvimento , Humanos , Doença de Parkinson/metabolismo , alfa-Sinucleína/metabolismo
7.
Brain ; 143(6): 1811-1825, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32436573

RESUMO

The polyglutamine (polyQ) diseases are a group of inherited neurodegenerative diseases that include Huntington's disease, various spinocerebellar ataxias, spinal and bulbar muscular atrophy, and dentatorubral pallidoluysian atrophy. They are caused by the abnormal expansion of a CAG repeat coding for the polyQ stretch in the causative gene of each disease. The expanded polyQ stretches trigger abnormal ß-sheet conformational transition and oligomerization followed by aggregation of the polyQ proteins in the affected neurons, leading to neuronal toxicity and neurodegeneration. Disease-modifying therapies that attenuate both symptoms and molecular pathogenesis of polyQ diseases remain an unmet clinical need. Here we identified arginine, a chemical chaperone that facilitates proper protein folding, as a novel compound that targets the upstream processes of polyQ protein aggregation by stabilizing the polyQ protein conformation. We first screened representative chemical chaperones using an in vitro polyQ aggregation assay, and identified arginine as a potent polyQ aggregation inhibitor. Our in vitro and cellular assays revealed that arginine exerts its anti-aggregation property by inhibiting the toxic ß-sheet conformational transition and oligomerization of polyQ proteins before the formation of insoluble aggregates. Arginine exhibited therapeutic effects on neurological symptoms and protein aggregation pathology in Caenorhabditis elegans, Drosophila, and two different mouse models of polyQ diseases. Arginine was also effective in a polyQ mouse model when administered after symptom onset. As arginine has been safely used for urea cycle defects and for mitochondrial myopathy, encephalopathy, lactic acid and stroke syndrome patients, and efficiently crosses the blood-brain barrier, a drug-repositioning approach for arginine would enable prompt clinical application as a promising disease-modifier drug for the polyQ diseases.


Assuntos
Arginina/metabolismo , Arginina/farmacologia , Peptídeos/metabolismo , Animais , Caenorhabditis elegans/metabolismo , Modelos Animais de Doenças , Drosophila/metabolismo , Feminino , Transtornos Heredodegenerativos do Sistema Nervoso/genética , Doença de Huntington/genética , Masculino , Camundongos , Camundongos Endogâmicos , Chaperonas Moleculares/genética , Peptídeos/genética , Agregação Patológica de Proteínas , Conformação Proteica/efeitos dos fármacos , Dobramento de Proteína/efeitos dos fármacos , Ataxias Espinocerebelares/genética
8.
Hum Mol Genet ; 27(5): 823-836, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29309590

RESUMO

Mutations in DNAJC13 gene have been linked to familial form of Parkinson's disease (PD) with Lewy pathology. DNAJC13 is an endosome-related protein and believed to regulate endosomal membrane trafficking. However, the mechanistic link between DNAJC13 mutation and α-synuclein (αSYN) pathology toward neurodegeneration remains poorly understood. In this study, we showed that PD-linked N855S-mutant DNAJC13 caused αSYN accumulation in the endosomal compartment, presumably due to defective cargo trafficking from the early endosome to the late and/or recycling endosome. In vivo experiments using human αSYN transgenic flies showed that mutant DNAJC13 not only increased the amount of insoluble αSYN in fly head but also induced dopaminergic neurodegeneration, rough eye phenotype and age-dependent locomotor impairment. Together, these findings suggest that DNAJC13 mutation perturbs multi-directional endosomal trafficking, resulting in the aberrant endosomal retention of αSYN, which might predispose to the neurodegenerative process that leads to PD.


Assuntos
Endossomos/metabolismo , Proteínas de Filamentos Intermediários/metabolismo , Chaperonas Moleculares/genética , Mutação , Doença de Parkinson/genética , Actinas/metabolismo , Animais , Animais Geneticamente Modificados , Transporte Biológico , Células COS , Chlorocebus aethiops , Neurônios Dopaminérgicos/patologia , Drosophila/genética , Endossomos/genética , Olho/patologia , Humanos , Proteínas de Filamentos Intermediários/genética , Locomoção/genética , Chaperonas Moleculares/metabolismo , Síndromes Neurotóxicas/etiologia , Síndromes Neurotóxicas/genética , Doença de Parkinson/fisiopatologia
9.
Histochem Cell Biol ; 153(2): 111-119, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31734714

RESUMO

Glycolaldehyde (GA) is a highly reactive hydroxyaldehyde and one of the glycolytic metabolites producing advanced glycation endproducts (AGEs), but its toxicity toward neurons and Schwann cells remains unclear. In the present study, we found that GA exhibited more potent toxicity than other AGE precursors (glyceraldehyde, glyoxal, methylglyoxal and 3-deoxyglucosone) against immortalized IFRS1 adult rat Schwann cells and ND7/23 neuroblastoma × neonatal rat dorsal root ganglion (DRG) neuron hybrid cells. GA affected adult rat DRG neurons and ND7/23 cells more severely than GA-derived AGEs, and exhibited concentration- and time-dependent toxicity toward ND7/23 cells (10 < 100 < 250 < 500 µM; 6 h < 24 h). Treatment with 500 µM GA significantly up-regulated the phosphorylation of c-jun N-terminal kinase (JNK) and p-38 mitogen-activated kinase (p-38 MAPK) in ND7/23 cells. Furthermore, GA-induced ND7/23 cell death was significantly inhibited due to co-treatment with 10 µM of the JNK inhibitor SP600125 or the p-38 MAPK inhibitor SB239063. These findings suggest the involvement of JNK and p-38 MAPK-signaling pathways in GA-induced neuronal cell death and that enhanced GA production under diabetic conditions might be involved in the pathogenesis of diabetic neuropathy.


Assuntos
Acetaldeído/análogos & derivados , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Células Receptoras Sensoriais/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Acetaldeído/farmacologia , Animais , Morte Celular/efeitos dos fármacos , Células Cultivadas , Ativação Enzimática/efeitos dos fármacos , Feminino , Ratos , Ratos Wistar , Células Receptoras Sensoriais/metabolismo
10.
Brain ; 142(9): 2845-2859, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31312839

RESUMO

Mutations in lysosomal genes increase the risk of neurodegenerative diseases, as is the case for Parkinson's disease. Here, we found that pathogenic and protective mutations in arylsulfatase A (ARSA), a gene responsible for metachromatic leukodystrophy, a lysosomal storage disorder, are linked to Parkinson's disease. Plasma ARSA protein levels were changed in Parkinson's disease patients. ARSA deficiency caused increases in α-synuclein aggregation and secretion, and increases in α-synuclein propagation in cells and nematodes. Despite being a lysosomal protein, ARSA directly interacts with α-synuclein in the cytosol. The interaction was more extensive with protective ARSA variant and less with pathogenic ARSA variant than wild-type. ARSA inhibited the in vitro fibrillation of α-synuclein in a dose-dependent manner. Ectopic expression of ARSA reversed the α-synuclein phenotypes in both cell and fly models of synucleinopathy, the effects correlating with the extent of the physical interaction between these molecules. Collectively, these results suggest that ARSA is a genetic modifier of Parkinson's disease pathogenesis, acting as a molecular chaperone for α-synuclein.


Assuntos
Cerebrosídeo Sulfatase/fisiologia , Chaperonas Moleculares/metabolismo , Mutação de Sentido Incorreto , Doença de Parkinson/metabolismo , Mutação Puntual , alfa-Sinucleína/metabolismo , Adulto , Idoso , Animais , Animais Geneticamente Modificados , Encéfalo/enzimologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Células Cultivadas , Cerebrosídeo Sulfatase/sangue , Cerebrosídeo Sulfatase/genética , Demência/sangue , Demência/etiologia , Proteínas de Drosophila/deficiência , Proteínas de Drosophila/genética , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Feminino , Técnicas de Inativação de Genes , Genes Dominantes , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/genética , Doença de Parkinson/psicologia , Linhagem , Agregação Patológica de Proteínas/genética , Mapeamento de Interação de Proteínas , Proteínas Recombinantes/metabolismo
11.
PLoS Biol ; 14(1): e1002361, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26812143

RESUMO

Amyloids are ordered protein aggregates that are typically associated with neurodegenerative diseases and cognitive impairment. By contrast, the amyloid-like state of the neuronal RNA binding protein Orb2 in Drosophila was recently implicated in memory consolidation, but it remains unclear what features of this functional amyloid-like protein give rise to such diametrically opposed behaviour. Here, using an array of biophysical, cell biological and behavioural assays we have characterized the structural features of Orb2 from the monomer to the amyloid state. Surprisingly, we find that Orb2 shares many structural traits with pathological amyloids, including the intermediate toxic oligomeric species, which can be sequestered in vivo in hetero-oligomers by pathological amyloids. However, unlike pathological amyloids, Orb2 rapidly forms amyloids and its toxic intermediates are extremely transient, indicating that kinetic parameters differentiate this functional amyloid from pathological amyloids. We also observed that a well-known anti-amyloidogenic peptide interferes with long-term memory in Drosophila. These results provide structural insights into how the amyloid-like state of the Orb2 protein can stabilize memory and be nontoxic. They also provide insight into how amyloid-based diseases may affect memory processes.


Assuntos
Proteínas Amiloidogênicas/metabolismo , Proteínas de Drosophila/metabolismo , Consolidação da Memória , Fatores de Transcrição/metabolismo , Fatores de Poliadenilação e Clivagem de mRNA/metabolismo , Animais , Células COS , Chlorocebus aethiops , Proteínas de Drosophila/química , Proteínas de Drosophila/genética , Drosophila melanogaster , Feminino , Masculino , Mutação , Oligopeptídeos , Estrutura Terciária de Proteína , Fatores de Transcrição/química , Fatores de Transcrição/genética , Leveduras , Fatores de Poliadenilação e Clivagem de mRNA/química , Fatores de Poliadenilação e Clivagem de mRNA/genética
12.
Pediatr Nephrol ; 34(2): 295-299, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30255447

RESUMO

BACKGROUND: The purpose of this study was to resolve the clinical question as to whether all patients with unilateral multicystic dysplastic kidney (MCDK) should receive voiding cystourethrography (VCUG). METHODS: This is a retrospective study using cross-sectional analysis. Seventy-five children with unilateral MCDK were enrolled, excluding patients with other genetic or chromosome abnormalities, spinal cord diseases, or anal atresia. We reviewed their records from medical charts and calculated risk factors for abnormal VCUG using multivariate logistic regression analysis. RESULTS: Abnormal VCUG findings were present in 24 of 75 patients (32.0%), specifically, vesicoureteral reflux (VUR) in 8 (10.6%), including high-grade VUR in 2 (2.7%), and only lower urinary tract or bladder disease in 16 (21.3%). In multivariate analysis, only abnormal findings by ultrasonography was an independent risk factor for abnormal VCUG findings with statistical significance in multivariate analysis (OR 6.57; 95% CI 1.99-26.26; P = 0.002). When we excluded five patients who showed similar findings by ultrasonography and VCUG, abnormal findings by ultrasonography were again calculated as an independent risk factor (OR 4.44; 95% CI 1.26-28.42; P = 0.02). Sensitivity, specificity, positive predictive value, and negative predictive value of abnormal findings by ultrasonography to predict urologic anomalies by VCUG in these children were 83%, 59%, 49%, and 88%, respectively. Two children required a third ultrasonography to detect abnormal findings. CONCLUSIONS: We can select, using only abnormal findings by ultrasonography, children with unilateral MCDK who should undergo VCUG. We would also like to emphasize that ultrasonography should be performed repeatedly to detect congenital anomalies of the urinary tract.


Assuntos
Cistografia , Rim Displásico Multicístico/complicações , Uretra/diagnóstico por imagem , Bexiga Urinária/diagnóstico por imagem , Refluxo Vesicoureteral/diagnóstico por imagem , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Lactente , Recém-Nascido , Modelos Logísticos , Imageamento por Ressonância Magnética , Masculino , Análise Multivariada , Seleção de Pacientes , Estudos Retrospectivos , Fatores de Risco , Ultrassonografia , Uretra/fisiopatologia , Bexiga Urinária/fisiopatologia , Micção/fisiologia , Refluxo Vesicoureteral/etiologia , Refluxo Vesicoureteral/fisiopatologia , Adulto Jovem
13.
Endocr J ; 66(4): 359-368, 2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-30880294

RESUMO

The Japan Endocrine Society (JES) has the largest ratio of female membership among societies associated with Internal Medicine in Japan; half of female members are in their 20s or 30s at present. In 2009, JES organized the "JES-We-Can" committee to promote women's career development. To evaluate the effectiveness of JES-We-Can, we investigated the gender balance of various activities at JES in fiscal 2009 and 2017. Significant gender-differences were not observed in the acquisition rate of board-certified endocrinologists (BCEs) aged <40 y in 2009 and 2017. However, the acquisition rate of BCEs among women aged ≥40 y was significantly lower than men in 2009. In 2017, the gender-difference among BCEs in this group (currently aged ≥50 y) has considerably improved, but is not resolved. The acquisition rate of certificated endocrine educators (CEEs) among women was still significantly lower than men at all ages in 2017. Since the ratio of women oral speakers or poster presenters at annual academic meetings have grown to equal or surpass the membership ratio, female members make efficient contributions to JES. The numbers of women chairpersons, symposiasts, lecturers and invited speakers have increased, but remain limited. JES-We-Can was found to be effective in reducing the gender gap in academic activities at JES, but JES-We-Can should support women more intensely to raise the rate of CEEs among all ages and BCEs currently over 50 y, and to promote more women into higher positions in JES in the future. These actions are expected to introduce new and diverse perspectives into academia.


Assuntos
Endocrinologistas , Sexismo , Sociedades Científicas , Feminino , Humanos , Japão , Masculino , Fatores Sexuais
15.
Proc Natl Acad Sci U S A ; 112(19): E2497-506, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25918398

RESUMO

The heat shock response (HSR), a transcriptional response that up-regulates molecular chaperones upon heat shock, is necessary for cell survival in a stressful environment to maintain protein homeostasis (proteostasis). However, there is accumulating evidence that the HSR does not ubiquitously occur under stress conditions, but largely depends on the cell types. Despite such imbalanced HSR among different cells and tissues, molecular mechanisms by which multicellular organisms maintain their global proteostasis have remained poorly understood. Here, we report that proteostasis can be maintained by molecular chaperones not only in a cell-autonomous manner but also in a non-cell-autonomous manner. We found that elevated expression of molecular chaperones, such as Hsp40 and Hsp70, in a group of cells improves proteostasis in other groups of cells, both in cultured cells and in Drosophila expressing aggregation-prone polyglutamine proteins. We also found that Hsp40, as well as Hsp70 and Hsp90, is physiologically secreted from cells via exosomes, and that the J domain at the N terminus is responsible for its exosome-mediated secretion. Addition of Hsp40/Hsp70-containing exosomes to the culture medium of the polyglutamine-expressing cells results in efficient suppression of inclusion body formation, indicating that molecular chaperones non-cell autonomously improve the protein-folding environment via exosome-mediated transmission. Our study reveals that intercellular chaperone transmission mediated by exosomes is a novel molecular mechanism for non-cell-autonomous maintenance of organismal proteostasis that could functionally compensate for the imbalanced state of the HSR among different cells, and also provides a novel physiological role of exosomes that contributes to maintenance of organismal proteostasis.


Assuntos
Exossomos/metabolismo , Chaperonas Moleculares/metabolismo , Animais , Animais Geneticamente Modificados , Linhagem Celular , Drosophila , Drosophila melanogaster , Proteínas de Choque Térmico HSP40/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/metabolismo , Proteínas de Choque Térmico/metabolismo , Homeostase , Camundongos , Microscopia Eletrônica , Doenças Neurodegenerativas/patologia , Peptídeos/química , Dobramento de Proteína , Estrutura Terciária de Proteína , Transdução de Sinais , Transcrição Gênica , Transfecção
16.
Hum Mol Genet ; 24(23): 6675-86, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26362253

RESUMO

Alpha-synuclein (αSyn) plays a central role in the pathogenesis of Parkinson's disease (PD) and dementia with Lewy bodies (DLB). Recent multicenter genetic studies have revealed that mutations in the glucocerebrosidase 1 (GBA1) gene, which are responsible for Gaucher's disease, are strong risk factors for PD and DLB. However, the mechanistic link between the functional loss of glucocerebrosidase (GCase) and the toxicity of αSyn in vivo is not fully understood. In this study, we employed Drosophila models to examine the effect of GCase deficiency on the neurotoxicity of αSyn and its molecular mechanism. Behavioral and histological analyses showed that knockdown of the Drosophila homolog of GBA1 (dGBA1) exacerbates the locomotor dysfunction, loss of dopaminergic neurons and retinal degeneration of αSyn-expressing flies. This phenotypic aggravation was associated with the accumulation of proteinase K (PK)-resistant αSyn, rather than with changes in the total amount of αSyn, raising the possibility that glucosylceramide (GlcCer), a substrate of GCase, accelerates the misfolding of αSyn. Indeed, in vitro experiments revealed that GlcCer directly promotes the conversion of recombinant αSyn into the PK-resistant form, representing a toxic conformational change. Similar to dGBA1 knockdown, knockdown of the Drosophila homolog of ß-galactosidase (ß-Gal) also aggravated locomotor dysfunction of the αSyn flies, and its substrate GM1 ganglioside accelerated the formation of PK-resistant αSyn. Our findings suggest that the functional loss of GCase or ß-Gal promotes the toxic conversion of αSyn via aberrant interactions between αSyn and their substrate glycolipids, leading to the aggravation of αSyn-mediated neurodegeneration.


Assuntos
Glucosilceramidase/genética , Transtornos Parkinsonianos/etiologia , alfa-Sinucleína/metabolismo , Animais , Modelos Animais de Doenças , Proteínas de Drosophila/genética , Drosophila melanogaster/metabolismo , Endopeptidase K/metabolismo , Técnicas de Silenciamento de Genes , Glucosilceramidase/deficiência , Glucosilceramidase/metabolismo , Glucosilceramidas/metabolismo , Humanos , Masculino , Transtornos Parkinsonianos/metabolismo , Transtornos Parkinsonianos/fisiopatologia , Agregação Patológica de Proteínas , Dobramento de Proteína , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
17.
Biochem Biophys Res Commun ; 485(2): 261-266, 2017 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-28235482

RESUMO

Activation-induced cytidine deaminase (AID) is essential for diversification of the Ig variable region (IgV). AID is excluded from the nucleus, where it normally functions. However, the molecular mechanisms responsible for regulating AID localization remain to be elucidated. The SR-protein splicing factor SRSF1 is a nucleocytoplasmic shuttling protein, a splicing isoform of which called SRSF1-3, has previously been shown to contribute to IgV diversification in chicken DT40 cells. In this study, we examined whether SRSF1-3 functions in IgV diversification by promoting nuclear localization of AID. AID expressed alone was localized predominantly in the cytoplasm. In contrast, co-expression of AID with SRSF1-3 led to the nuclear accumulation of both AID and SRSF1-3 and the formation of a protein complex that contained them both, although SRSF1-3 was dispensable for nuclear import of AID. Expression of either SRSF1-3 or a C-terminally-truncated AID mutant increased IgV diversification in DT40 cells. However, overexpression of exogenous SRSF1-3 was unable to further enhance IgV diversification in DT40 cells expressing the truncated AID mutant, although SRSF1-3 was able to form a protein complex with the AID mutant. These results suggest that SRSF1-3 promotes nuclear localization of AID probably by forming a nuclear protein complex, which might stabilize nuclear AID and induce IgV diversification in an AID C-terminus-dependent manner.


Assuntos
Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Galinhas/genética , Citidina Desaminase/metabolismo , Região Variável de Imunoglobulina/genética , Fatores de Processamento de Serina-Arginina/metabolismo , Hipermutação Somática de Imunoglobulina , Transporte Ativo do Núcleo Celular , Animais , Linhagem Celular , Núcleo Celular/genética , Núcleo Celular/metabolismo , Galinhas/metabolismo , Conversão Gênica
18.
J Biol Chem ; 290(3): 1442-53, 2015 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-25480790

RESUMO

Oligomer formation and accumulation of pathogenic proteins are key events in the pathomechanisms of many neurodegenerative diseases, such as Alzheimer disease, ALS, and the polyglutamine (polyQ) diseases. The autophagy-lysosome degradation system may have therapeutic potential against these diseases because it can degrade even large oligomers. Although p62/sequestosome 1 plays a physiological role in selective autophagy of ubiquitinated proteins, whether p62 recognizes and degrades pathogenic proteins in neurodegenerative diseases has remained unclear. In this study, to elucidate the role of p62 in such pathogenic conditions in vivo, we used Drosophila models of neurodegenerative diseases. We found that p62 predominantly co-localizes with cytoplasmic polyQ protein aggregates in the MJDtr-Q78 polyQ disease model flies. Loss of p62 function resulted in significant exacerbation of eye degeneration in these flies. Immunohistochemical analyses revealed enhanced accumulation of cytoplasmic aggregates by p62 knockdown in the MJDtr-Q78 flies, similarly to knockdown of autophagy-related genes (Atgs). Knockdown of both p62 and Atgs did not show any additive effects in the MJDtr-Q78 flies, implying that p62 function is mediated by autophagy. Biochemical analyses showed that loss of p62 function delays the degradation of the MJDtr-Q78 protein, especially its oligomeric species. We also found that loss of p62 function exacerbates eye degeneration in another polyQ disease fly model as well as in ALS model flies. We therefore conclude that p62 plays a protective role against polyQ-induced neurodegeneration, by the autophagic degradation of polyQ protein oligomers in vivo, indicating its therapeutic potential for the polyQ diseases and possibly for other neurodegenerative diseases.


Assuntos
Autofagia , Proteínas de Drosophila/metabolismo , Doenças Neurodegenerativas/metabolismo , Peptídeos/química , Células Fotorreceptoras de Invertebrados/metabolismo , Fatores Associados à Proteína de Ligação a TATA/metabolismo , Fator de Transcrição TFIID/metabolismo , Animais , Citoplasma/metabolismo , Drosophila , Imuno-Histoquímica , Microscopia Eletrônica de Varredura , Fosforilação , Células Fotorreceptoras de Invertebrados/ultraestrutura , Desnaturação Proteica , Dobramento de Proteína , Transgenes , Proteínas Ubiquitinadas/química
19.
BMC Urol ; 15: 2, 2015 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-25604159

RESUMO

BACKGROUND: To investigate the expression of parathyroid hormone (PTH)/PTH-related peptide (PTHrP) receptor 1 (PTH1R) in clinical specimens of normal and diseased bladders. PTHrP is a unique stretch-induced endogenous detrusor relaxant that functions via PTH1R. We hypothesized that suppression of this axis could be involved in the pathogenesis of bladder disease. METHODS: PTH1R expression in clinical samples was examined by immunohistochemistry. Normal kidney tissue from a patient with renal cancer and bladder specimens from patients undergoing ureteral reimplantation for vesicoureteral reflux or partial cystectomy for urachal cyst were examined as normal control organs. These were compared with 13 diseased bladder specimens from patients undergoing bladder augmentation. The augmentation patients ranged from 8 to 31 years old (median 15 years), including 9 males and 4 females. Seven patients had spinal disorders, 3 had posterior urethral valves and 3 non-neurogenic neurogenic bladders (Hinman syndrome). RESULTS: Renal tubules, detrusor muscle and blood vessels in normal control bladders stained positive for PTH1R. According to preoperative urodynamic studies of augmentation patients, the median percent bladder capacity compared with the age-standard was 43.6% (range 1.5-86.6%), median intravesical pressure at maximal capacity was 30 cmH2O (range 10-107 cmH2O), and median compliance was 3.93 ml/cmH2O (range 0.05-30.3 ml/cmH2O). Detrusor overactivity was observed in five cases (38.5%). All augmented bladders showed negative stainings in PTH1R expression in the detrusor tissue, but positive staining of blood vessels in majority of the cases. CONCLUSIONS: Downregulation of PTH1R may be involved in the pathogenesis of human end-stage bladder disease requiring augmentation.


Assuntos
Hormônio Paratireóideo/metabolismo , Receptor Tipo 1 de Hormônio Paratireóideo/metabolismo , Doenças da Bexiga Urinária/metabolismo , Bexiga Urinária/metabolismo , Adolescente , Adulto , Criança , Regulação para Baixo , Feminino , Humanos , Imuno-Histoquímica , Masculino , Bexiga Urinária/fisiopatologia , Doenças da Bexiga Urinária/fisiopatologia , Urodinâmica , Adulto Jovem
20.
J Man Manip Ther ; 23(4): 205-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26917938

RESUMO

BACKGROUND: We suggested a standing back extension exercise 'One Stretch' based on the McKenzie method, to examine the ability to improve or prevent low back pain (LBP) in Japanese care workers. METHODS: We conducted a single-center, non-randomized, controlled study in Japan. Care workers in an intervention group received an exercise manual and a 30-minute seminar on LBP and were encouraged with a group approach, while care workers in a control group were given only the manual. All care workers answered questionnaires at the baseline and end of a 1-year study period. The subjective improvement of LBP and compliance with the exercise were evaluated. RESULTS: In all, 64 workers in the intervention group and 72 in the control group participated in this study. More care workers in the intervention group exercised regularly and improved or prevented LBP than in the control group (P = 0·003 and P<0·0001, respectively). In the intervention group, none had a first medical consultation or were absent from disability for LBP by the end of the study period. CONCLUSION: The exercise 'One Stretch' would be effective to improve or prevent LBP in care workers. Our group approach would lead to better compliance with the exercise.

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