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1.
Clin Nephrol ; 101(5): 250-256, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38329919

RESUMO

We report on a 53-year-old Japanese man diagnosed with gastric Burkitt's monomorphic post-transplant lymphoproliferative disorder (B-PTLD) after endoscopy for gastric discomfort 28 months after the patient underwent renal transplantation in Ethiopia. Serum Epstein-Barr virus (EBV) tests were negative before transplantation, but the tumor cells collected from a gastric biopsy showed positive EBV-encoded small RNAs (EBER) at B-PTLD onset. Intensive treatment started with R(rituximab)-CHOP therapy and continued with DA-EPOCH-R therapy has been effective, and relapse has not yet occurred. Burkitt lymphoma has a poor prognosis, but B-PTLD may be effectively treated with high-dose chemotherapy. This is a rare case of gastric B-PTLD in a Japanese patient.


Assuntos
Infecções por Vírus Epstein-Barr , Transplante de Rim , Transtornos Linfoproliferativos , Humanos , Masculino , Pessoa de Meia-Idade , Infecções por Vírus Epstein-Barr/complicações , Infecções por Vírus Epstein-Barr/diagnóstico , Herpesvirus Humano 4 , Transplante de Rim/efeitos adversos , Transtornos Linfoproliferativos/diagnóstico , Transtornos Linfoproliferativos/tratamento farmacológico , Transtornos Linfoproliferativos/etiologia , Rituximab/uso terapêutico
2.
Kidney Int Rep ; 9(2): 323-333, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38344735

RESUMO

Introduction: Data on longitudinal trajectory of kidney function decline and fluctuation in albuminuria leading to end-stage kidney disease (ESKD) is sparse in patients with type 2 diabetes. Methods: Using data from an observational study of patients with type 2 diabetes and biopsy-confirmed diabetic kidney disease (DKD), generalized additive mixed models (GAMMs) were performed to quantify patterns of longitudinal trajectory of estimated glomerular filtration rate (eGFR) decline to ESKD associated with repeated measures of urine albumin-to-creatinine ratio (ACR). Results: Over a median follow-up period of 3.3 years, 155 of 319 patients progressed to ESKD. Among these patients, 91.6% exhibited a curvilinear pattern in their eGFR trajectory. The median coefficient of variation for ACR, representing the variability in ACR measurements, was 48.9 (interquartile range: 36.9, 68.2). The median compound annual growth rate (CAGR) for ACR, reflecting the variation in ACR progression over time, was 43.6% (interquartile range: 0.0, 102.5); and 84.5% of patients developed nephrotic-range albuminuria, with a majority remaining nephrotic and subsequently progressing to ESKD. There was a positive association between the instantaneous speed of eGFR decline and ACR. Conclusion: The observed curvilinear pattern in eGFR trajectory, high variability in ACR progression over time, and positive correlation between the speed of eGFR decline and ACR highlight the complex dynamics of disease progression and emphasize close monitoring of ACR fluctuation over time in patients with DKD.

3.
BMJ Case Rep ; 16(11)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37923332

RESUMO

A man in his late 50s without notable medical background was admitted with subacute onset of bilateral lower extremity weakness. Blood and physiological examinations revealed no significant abnormalities. Cerebrospinal fluid (CSF) examination revealed elevated cell count and protein levels and an immunoglobulin G index of 2.01. T1-weighted MRI showed swelling and enhancement of the cauda equina. After admission, the patient developed bowel and bladder incontinence, deteriorated to manual muscle test 0 and developed right trochlear, trigeminal and facial nerve palsy. He underwent a cauda equina biopsy and was diagnosed with neurosarcoidosis. After methylprednisolone pulse therapy and corticosteroid treatment, cauda equina syndrome including lower extremity weakness and cerebral nerve palsy improved. The patient's daily activities improved to the baseline level over 2 months after discharge. Serum and CSF soluble interleukin-2 receptor levels were within the reference range and decreased with the improvement of neurological and imaging findings.


Assuntos
Cauda Equina , Doenças do Sistema Nervoso Central , Humanos , Masculino , Cauda Equina/patologia , Doenças do Sistema Nervoso Central/diagnóstico , Doenças do Sistema Nervoso Central/diagnóstico por imagem , Debilidade Muscular/patologia , Paralisia , Pessoa de Meia-Idade
4.
BMJ Case Rep ; 16(6)2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37316284

RESUMO

A man in his early 70s with a 4-year history of diffuse large B cell lymphoma (DLBCL) was admitted to our hospital with diplopia and achromatopsia. Neurological examination revealed visual impairment, ocular motility disorder and diplopia on looking to the left. Blood and cerebrospinal fluid investigations showed no significant findings. MRI revealed diffusely thickened dura mater and contrast-enhanced structures in the left apical orbit, consistent with hypertrophic pachymeningitis (HP). We performed an open dural biopsy to distinguish the diagnosis from lymphoma. The pathological diagnosis was idiopathic HP, and DLBCL recurrence was ruled out. Following methylprednisolone pulse and oral prednisolone therapy, his neurological abnormalities gradually receded. Open dural biopsy played an important role not only in diagnosing idiopathic HP but also in relieving the pressure on the optic nerve.


Assuntos
Linfoma Difuso de Grandes Células B , Meningite , Masculino , Humanos , Diplopia , Linfoma Difuso de Grandes Células B/complicações , Linfoma Difuso de Grandes Células B/diagnóstico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Pacientes , Biópsia , Meningite/diagnóstico , Meningite/tratamento farmacológico
5.
Intern Med ; 62(14): 2099-2102, 2023 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-36418100

RESUMO

We encountered an 86-year-old Japanese woman who presented with proteinuria (0.4 g/day) and hematuria (red blood cell sediment >100/high-power field), a decreased renal function (serum creatinine, 1.51 mg/dL), and elevated myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) levels (231 IU/mL) during treatment of rheumatoid arthritis with abatacept (a cytotoxic T-lymphocyte-associated antigen 4 agent) and adalimumab (a tumor necrosis factor-α agent). A kidney biopsy showed pauci-immune necrotizing glomerulonephritis, and ANCA-associated vasculitis was diagnosed. Treatment with tocilizumab (an interleukin 6 receptor antibody) monotherapy resulted in the improvement of renal findings and normalization of rheumatoid arthritis disease activity and serum ANCA levels. Tocilizumab can also suppress ANCA-associated vasculitis.


Assuntos
Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos , Artrite Reumatoide , Glomerulonefrite , Nefrite , Feminino , Humanos , Idoso de 80 Anos ou mais , Anticorpos Anticitoplasma de Neutrófilos , Abatacepte/efeitos adversos , Adalimumab/efeitos adversos , Glomerulonefrite/induzido quimicamente , Glomerulonefrite/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/induzido quimicamente , Vasculite Associada a Anticorpo Anticitoplasma de Neutrófilos/tratamento farmacológico , Peroxidase
6.
Front Nephrol ; 3: 1331757, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38318200

RESUMO

We present a 51-year-old male patient with a history of Child-Pugh Grade B alcoholic liver cirrhosis (ALC) who developed renal impairment (serum creatinine of 2.00 mg/dL) and nephrotic syndrome (a urinary protein level of 4.35 g/gCr). The patient was diagnosed with immunoglobulin A nephropathy (IgAN) associated with ALC based on findings from comprehensive evaluations, including markedly elevated serum IgA levels (883.7 mg/dL), a kidney biopsy revealing significant IgA deposition in the para-mesangial area, and a liver diagnosis showing long-standing advanced ALC. Our treatment approach involved initiating dapagliflozin therapy, a sodium-glucose cotransporter-2 (SGLT2) inhibitor, alongside strict alcohol abstinence. Remarkably, the patient demonstrated a dramatic reduction in proteinuria within one week of dapagliflozin administration. No hypoglycemic events were observed. This case adds valuable clinical insights into the potential therapeutic role of SGLT2 inhibitors in IgAN associated with ALC. Specifically, in cases where conventional steroid therapies may be contraindicated due to coexisting comorbidities such as diabetes or obesity, dapagliflozin emerges as a potentially efficacious alternative. Further investigations are warranted to validate these preliminary observations.

7.
Kidney Med ; 4(6): 100477, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35637924

RESUMO

A 59-year-old Japanese woman with a 22-year history of long-term hemodialysis was admitted to our hospital for further examination of hyperglycemia and anemia. Five months before hospitalization, her fasting plasma glucose value was 99 mg/dL and her glycated hemoglobin was 5.7%. On admission, her fasting plasma glucose value was 873 mg/dL, glycated hemoglobin was 16.2%, C-peptide reactivity was 22.3 ng/mL (reference range, 0.5-3.0), and homeostasis model assessment of insulin resistance (HOMA-IR) was 10.6 (reference range, <2.0); the high HOMA-IR indicated high insulin resistance. Intensive insulin therapy was started for hyperglycemia, which required more than 40 units/day. Computed tomography showed a hypervascular lesion 2.2 cm in diameter on the right kidney; therefore, right nephrectomy was performed. Complete resection was confirmed, and the lesion was diagnosed as a clear cell type of renal cell carcinoma (RCC). Immediately after nephrectomy, glycemic control normalized and administration of insulin was discontinued. Fourteen days after nephrectomy, the HOMA-IR decreased to 2.96. RCC that develops in patients receiving long-term hemodialysis has been reported to be dialysis-related RCC, but there have been no reports suggesting a relationship between dialysis-related RCC and diabetes. To our knowledge, this is the first report of RCC presenting with the paraneoplastic syndrome of acute-onset diabetes because of insulin resistance.

8.
Intern Med ; 61(23): 3547-3552, 2022 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-35569979

RESUMO

We encountered a 77-year-old Japanese man who presented with nephrotic-range proteinuria 20 days after receiving ramucirumab treatment for metastatic sigmoid colon cancer. A kidney biopsy showed two characteristic histological findings. The first finding was podocyte injury with cellular crescent-like formation, although focal segmental glomerulosclerosis (FSGS) (collapsing variant) according to the Columbia classification may have been a more appropriate name for this injury, as hypertrophy and hyperplasia of epithelial cells, presumably resulting from podocyte injury, were seen between Bowman's capsule and the glomerular basement membrane (GBM); these changes appeared to be due to the collapse of the GBM rather than to GBM destruction with fibrinoid necrosis. The second finding was endotheliopathy characterized by prominent mesangial interposition via enlargement of the mesangial matrix with mesangiolysis. Proteinuria and renal dysfunction subsided after discontinuation of ramucirumab. Bevacizumab has been reported to induce glomerular microangiopathy with endothelial damage and swelling six months after treatment, but in this case, ramucirumab may have induced focal segmental glomerulosclerosis (FSGS) collapsing variant and glomerular microangiopathy with endotheliopathy via mesangial damage within 1 month. We believe that the damage to the glomerular podocyte and endothelial cells via mesangial damage secondary to ramucirumab in our patient was a different type of glomerular microangiopathy than the endothelial cell damage with enlargement of the subendothelial space caused by bevacizumab.


Assuntos
Glomerulosclerose Segmentar e Focal , Neoplasias do Colo Sigmoide , Masculino , Humanos , Idoso , Células Endoteliais/patologia , Bevacizumab/efeitos adversos , Proteinúria , Membrana Basal Glomerular/patologia , Ramucirumab
9.
J Endocr Soc ; 6(5): bvac038, 2022 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-35402762

RESUMO

Among the side effects of methimazole (MMI) for the treatment of Graves' disease, MMI-induced acute pancreatitis (MIP) is a rare adverse reaction, with only 7 cases being reported to date. However, 2 large-scale population-based studies recently revealed that the risk of MIP was significantly higher, ranging from 0.02% to 0.56%. Although MIP is common in middle-aged and elderly Asian women, its pathogenesis remains largely unknown. We herein present a case of a 72-year-old Japanese woman with Graves' disease who developed MIP 12 days after the initiation of MMI. The MMI was discontinued, the patient was switched to propylthiouracil (PTU) therapy, and pancreatitis gradually resolved. Serological human leukocyte antigen (HLA) typing identified HLA-DRB1*08:03:02. This HLA allele was previously detected in a patient with MIP and is one of the major risk factors for agranulocytosis induced by antithyroid drugs, including PTU as well as MMI. In cases of MIP, PTU is being considered as an alternative to MMI; however, its safety needs further investigation and patients require close monitoring after the switch to PTU. Further studies are warranted, particularly on the relationship between MIP and the presence of HLA alleles causing antithyroid drug-induced agranulocytosis.

10.
Colloids Surf B Biointerfaces ; 205: 111853, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34098366

RESUMO

Thermodynamic studies on protein adsorption onto chromatographic surfaces mainly focus on the molecular level interaction between proteins and ligands. Yet, not much attention is given to the study of polymer grafted ligand architecture effect on thermodynamic parameters, nor to the relation between chromatographic parameters and the directly obtained thermodynamic parameters. These relations are needed in order to confer meaning and to ease future data interpretation of thermodynamic studies of protein adsorption. In this study, the adsorption of bovine serum albumin monomer (BSAm) onto chromatographic surfaces with grafted ligands was studied from a thermodynamic point of view together with chromatographic data. Isothermal titration calorimetry (ITC) results showed that BSAm adsorption is exothermic (ΔH¯ads < 0) when adsorbs onto Toyopearl GigaCapQ 650 M, Toyopearl Q600AR, and Q Sepharose XL, but endothermic (ΔH¯ads > 0) when adsorbs onto Toyopearl SuperQ and a conventional resin (Q Sepharose Fast Flow), showing clear differences in the driving forces of adsorption caused by different ligand architectures. In addition, we found a new relation between the salt required for protein elution and the change in adsorption enthalpy (ΔH¯ads) directly measured with ITC, intrinsically connecting both adsorption and desorption mechanisms.


Assuntos
Cromatografia , Polímeros , Adsorção , Ânions , Calorimetria , Termodinâmica
11.
Ann Vasc Dis ; 14(4): 407-410, 2021 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-35082952

RESUMO

Chronic mesenteric ischemia (CMI) involving occlusion and/or stenosis of multiple mesenteric arteries is rare. We report our experience with a 66-year-old man who presented with a more than 3 months history of abdominal pain and vomiting/diarrhea. A diagnosis of CMI due to occlusion of the superior mesenteric artery (SMA) and severe stenosis of the celiac artery by median arcuate ligament syndrome was made. Complete revascularization through iliac artery-SMA bypass grafting and arcuate ligament dissection assisted with staged-catheter intervention successfully alleviated the patient's symptoms. The patient has maintained a normal daily diet for 6 months postoperatively.

12.
Steroids ; 162: 108695, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32649998

RESUMO

A variety of metabolites derived from 25-hydroxyvitamin D3 [25(OH)D3], including its 3-epimer [Epi-25(OH)D3] and 3-O-sulfate [25(OH)D3-3S], is found in human plasma/serum. We hypothesized that the 3-O-sulfate of Epi-25(OH)D3 [Epi-25(OH)D3-3S] might be present in plasma/serum. Clarifying this point could improve our understanding of the metabolism of vitamin D3. In this study, we first carefully analyzed the cord plasma samples by derivatization-assisted liquid chromatography/electrospray ionization-tandem mass spectrometry and demonstrated the occurrence of Epi-25(OH)D3-3S in the plasma. However, the concentration ratio of Epi-25(OH)D3-3S to 25(OH)D3-3S (sulfated form) was infinitely lower than the ratio of Epi-25(OH)D3 to 25(OH)D3 (unconjugated form). To determine what caused this result, we next performed an in vitro experiment of the 3-O-sulfation for 25(OH)D3 and Epi-25(OH)D3 using the recombinant human sulfotransferase (SULT) 2A1. This in vitro experiment revealed that Epi-25(OH)D3 is a poor substrate for the 3-O-sulfation catalyzed by SULT2A1 as compared to 25(OH)D3. This substrate specificity of SULT2A1 would be the main cause for the result obtained from the analysis of the cord plasma samples.


Assuntos
Calcifediol/sangue , Calcifediol/metabolismo , Sangue Fetal/metabolismo , Proteínas Recombinantes/metabolismo , Sulfatos/metabolismo , Sulfotransferases/metabolismo , Humanos , Ligação Proteica
13.
JAMA Ophthalmol ; 138(1): 58-68, 2020 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31774457

RESUMO

Importance: The incidence of dry eye disease has increased; the potential for crowdsource data to help identify undiagnosed dry eye in symptomatic individuals remains unknown. Objective: To assess the characteristics and risk factors associated with diagnosed and undiagnosed symptomatic dry eye using the smartphone app DryEyeRhythm. Design, Setting, and Participants: A cross-sectional study using crowdsourced data was conducted including individuals in Japan who downloaded DryEyeRhythm and completed the entire questionnaire; duplicate users were excluded. DryEyeRhythm was released on November 2, 2016; the study was conducted from November 2, 2016, to January 12, 2018. Exposures: DryEyeRhythm data were collected on demographics, medical history, lifestyle, subjective symptoms, and disease-specific symptoms, using the Ocular Surface Disease Index (100-point scale; scores 0-12 indicate normal, healthy eyes; 13-22, mild dry eye; 23-32, moderate dry eye; 33-100, severe dry eye symptoms), and the Zung Self-Rating Depression Scale (total of 20 items, total score ranging from 20-80, with ≥40 highly suggestive of depression). Main Outcomes and Measures: Multivariate-adjusted logistic regression analysis was used to identify risk factors for symptomatic dry eye and to identify risk factors for undiagnosed symptomatic dry eye. Results: A total of 21 394 records were identified in our database; 4454 users, included 899 participants (27.3%) with diagnosed and 2395 participants (72.7%) with undiagnosed symptomatic dry eye, completed all questionnaires and their data were analyzed. A total of 2972 participants (66.7%) were women; mean (SD) age was 27.9 (12.6) years. The identified risk factors for symptomatic vs no symptomatic dry eye included younger age (odds ratio [OR], 0.99; 95% CI, 0.987-0.999, P = .02), female sex (OR, 1.99; 95% CI, 1.61-2.46; P < .001), pollinosis (termed hay fever on the questionnaire) (OR, 1.35; 95% CI, 1.18-1.55; P < .001), depression (OR, 1.78; 95% CI, 1.18-2.69; P = .006), mental illnesses other than depression or schizophrenia (OR, 1.87; 95% CI, 1.24-2.82; P = .003), current contact lens use (OR, 1.27; 95% CI, 1.09-1.48; P = .002), extended screen exposure (OR, 1.55; 95% CI, 1.25-1.91; P < .001), and smoking (OR, 1.65; 95% CI, 1.37-1.98; P < .001). The risk factors for undiagnosed vs diagnosed symptomatic dry eye included younger age (OR, 0.96; 95% CI, 0.95-0.97; P < .001), male sex (OR, 0.55; 95% CI, 0.42-0.72; P < .001), as well as absence of collagen disease (OR, 95% CI, 0.23; 0.09-0.60; P = .003), mental illnesses other than depression or schizophrenia (OR, 0.50; 95% CI, 0.36-0.69; P < .001), ophthalmic surgery other than cataract surgery and laser-assisted in situ keratomileusis (OR, 0.41; 95% CI, 0.27-0.64; P < .001), and current (OR, 0.64; 95% CI, 0.54-0.77; P < .001) or past (OR, 0.45; 95% CI, 0.34-0.58; P < .001) contact lens use. Conclusions and Relevance: This study's findings suggest that crowdsourced research identified individuals with diagnosed and undiagnosed symptomatic dry eye and the associated risk factors. These findings could play a role in earlier prevention or more effective interventions for dry eye disease.


Assuntos
Síndromes do Olho Seco/diagnóstico , Síndromes do Olho Seco/epidemiologia , Smartphone , Adulto , Estudos Transversais , Feminino , Humanos , Incidência , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Aplicativos Móveis , Razão de Chances , Fatores de Risco , Inquéritos e Questionários , Adulto Jovem
14.
J Orthop Sci ; 24(6): 1094-1104, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31492535

RESUMO

BACKGROUND: We developed the Locomonitor application (app), the world's first iOS app to study locomotive syndrome, using the ResearchKit and examined the prevalence and risk factors for locomotive syndrome in Japanese general individuals 20-69 years old in a nationwide cross-sectional observational study. METHODS: The participants were recruited from February to August 2016. The outcome measures for the locomotive function were evaluated by locomotive syndrome risk tests (LSRTs) using the Locomonitor app. The chi-squared test, a linear-by-linear association trend analysis, and Spearman's correlation test were performed as statistical analyses. RESULTS: A total of 2177 subjects from all prefectures in Japan were included (average 42.2 years old). The Locomo25 and Stand-Up test scores in female participants and the Two-Step test scores in male participants showed age-dependent deterioration. In the overall population, the incidence of Locomo stage 1 and 2, as evaluated by the Locomo25, Stand-Up test or Two-Step test, was 30.2% and 29.2%, respectively. In subjects without locomotive syndrome (40.5%), LSRT scores showed age-dependent deterioration in both sexes. Locomotive syndrome in participants with a body mass index (BMI) of ≥25 kg/m2 was more frequent than in those with a BMI of <25 kg/m2 (age- and gender-adjusted odds ratio [OR] 1.344 [95% confidence interval {CI} 1.03-1.75, p = 0.027]). Locomotive syndrome in participants with an exercise habit was less frequent than in those without an exercise habit (age- and gender-adjusted OR 0.499 [95% CI 0.33-0.755, p < 0.0001]). CONCLUSIONS: The Locomonitor app, a newly developed remote platform, revealed that approximately 20%-30% of Japanese individuals 20-69 years old in the general population met the definition of locomotive syndrome. Locomotive syndrome in participants with obesity was more frequent than those without obesity, while locomotive syndrome in participants with an exercise habit was less frequent than those without an exercise habit.


Assuntos
Locomoção , Programas de Rastreamento/métodos , Aplicativos Móveis , Limitação da Mobilidade , Adulto , Idoso , Estudos Transversais , Avaliação da Deficiência , Feminino , Humanos , Japão/epidemiologia , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Síndrome , Adulto Jovem
15.
Biomed Chromatogr ; 33(7): e4538, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30912169

RESUMO

A liquid chromatography/electrospray ionization-tandem mass spectrometry-based method was developed for the identification of the conjugation positions of the monoglucuronides of 25-hydroxyvitamin D3 [25(OH)D3 ] and 24,25-dihydroxyvitamin D3 [24,25(OH)2 D3 ] in human urine. The method employed derivatization with 4-(4-dimethylaminophenyl)-1,2,4-triazoline-3,5-dione to convert the glucuronides into fragmentable derivatives, which provided useful product ions for identifying the conjugation positions during the MS/MS. The derivatization also enhanced the assay sensitivity and specificity for urine sample analysis. The positional isomeric monoglucuronides, 25(OH)D3 -3- and -25-glucuronides, or 24,25(OH)2 D3 -3-, -24- and -25-glucuronides, were completely separated from each other under the optimized LC conditions. Using this method, the conjugation positions were successfully determined to be the C3 and C24 positions for the glucuronidated 25(OH)D3 and 24,25(OH)2 D3 , respectively. The 3-glucuronide was not present for 24,25(OH)2 D3 , unlike 25(OH)D3 , thus we found that selective glucuronidation occurs at the C24-hydroxy group for 24,25(OH)2 D3 .


Assuntos
Colecalciferol/urina , Cromatografia Líquida/métodos , Glucuronídeos/urina , Espectrometria de Massas em Tandem/métodos , Colecalciferol/química , Colecalciferol/metabolismo , Glucuronídeos/química , Glucuronídeos/metabolismo , Humanos , Espectrometria de Massas por Ionização por Electrospray/métodos
17.
J Neurochem ; 142(4): 534-544, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28547849

RESUMO

Adult neurogenesis in the subventricular zone of the lateral ventricle decreases with age. In the subventricular zone, the specialized extracellular matrix structures, known as fractones, contact neural stem cells and regulate neurogenesis. Fractones are composed of extracellular matrix components, such as heparan sulfate proteoglycans. We previously found that fractones capture and store fibroblast growth factor 2 (FGF-2) via heparan sulfate binding, and may deliver FGF-2 to neural stem cells in a timely manner. The heparan sulfate (HS) chains in the fractones of the aged subventricular zone are modified based on immunohistochemistry. However, how aging affects fractone composition and subsequent FGF-2 signaling and neurogenesis remains unknown. The formation of the FGF-fibroblast growth factor receptor-HS complex is necessary to activate FGF-2 signaling and induce the phosphorylation of extracellular signal-regulated kinase (Erk1/2). In this study, we observed a reduction in HS 6-O-sulfation, which is critical for FGF-2 signal transduction, and failure of the FGF-2-induced phosphorylation of Erk1/2 in the aged subventricular zone. In addition, we observed increased HS 6-O-endo-sulfatase, an enzyme that may be responsible for the HS modifications in aged fractones. In conclusion, the data revealed that heparan sulfate 6-O-sulfation is reduced and FGF-2-dependent Erk1/2 signaling is impaired in the aged subventricular zone. HS modifications in fractones might play a role in the reduced neurogenic activity in aging brains.


Assuntos
Envelhecimento/fisiologia , Proliferação de Células/efeitos dos fármacos , Fator 2 de Crescimento de Fibroblastos/metabolismo , Heparitina Sulfato/farmacologia , Ventrículos Laterais/efeitos dos fármacos , Neurogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Envelhecimento/efeitos dos fármacos , Animais , Matriz Extracelular/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Heparitina Sulfato/metabolismo , Masculino , Camundongos Endogâmicos C57BL
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