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Hideki Kimura

Publications and source records attributed to Hideki Kimura.

At least 19 recordsLinked to original sources
PubMed2006

The role of G-protein-coupled receptor kinase 5 in pathogenesis of sporadic Parkinson's disease.

Sporadic Parkinson's disease (sPD) is a common neurodegenerative disorder, characterized by selective degeneration of dopaminergic neurons in the substantia nigra. Although the pathogenesis of the disease remains undetermined, phosphorylation of alpha-synuclein and its oligomer formation seem to play a key role. However, the protein kinase(s) involved in the phosphorylation in the pathogenesis of sPD has not been identified. Here, we found that G-protein-coupled receptor kinase 5 (GRK5) accumulated in Lewy bodies and colocalized with alpha-synuclein in the pathological structures of the brains of sPD patients. In cotransfected cells, GRK5 phosphorylated Ser-129 of alpha-synuclein at the plasma membrane and induced translocation of phosphorylated alpha-synuclein to the perikaryal area. GRK5-catalyzed phosphorylation also promoted the formation of soluble oligomers and aggregates of alpha-synuclein. Genetic association study revealed haplotypic association of the GRK5 gene with susceptibility to sPD. The haplotype contained two functional single-nucleotide polymorphisms, m22.1 and m24, in introns of the GRK5 gene, which bound to YY1 (Yin Yang-1) and CREB-1 (cAMP response element-binding protein 1), respectively, and increased transcriptional activity of the reporter gene. The results suggest that phosphorylation of alpha-synuclein by GRK5 plays a crucial role in the pathogenesis of sPD.

Aged↗
PubMed2006

Spontaneous regression of bone metastasis from renal cell carcinoma; a case report.

BACKGROUND: Spontaneous regression of metastatic renal cell carcinoma is rarely observed. CASE PRESENTATION: Metastatic renal cell carcinoma was identified in a 70-year-old male using computed tomography-guided percutaneous needle biopsy. Two months after the diagnosis, a partial resection of the sternal bone was performed. Pathological examination revealed granulated tissue with bleeding and necrosis but no carcinogenic cells. CONCLUSION: We report a pathologically identified case in which a sternal bone metastasis that was noticed two years after radical nephrectomy regressed completely and spontaneously.

Aged↗
PubMed2006

Aberrant methylation of RASGRF2 and RASSF1A in human non-small cell lung cancer.

Aberrant methylation of promoter CpG that causes silencing of tumor suppressor genes (TSGs) may play a key role in the carcinogenesis of many cancer types. RASSF1A, regarded as a TSG, has been extensively studied in lung cancer and other malignant tumors, whereas RASGRF2 has only been reported to possibly play a role in the pathogenesis of pancreatic cancer cell lines. The aims of our study were to i) determine the methylation profile of RASGRF2 and ii) compare the methylation profiles of RASGRF2 with RASSF1A in lung cancer. We examined RASGRF2 expression by reverse transcription PCR and aberrant methylation of RASGRF2 by methylation-specific PCR in lung cancer cell lines. Loss of RASGRF2 expression was presented in 36% lung cancer cell lines while aberrant methylation of RASGRF2 was present in 30% (3/10) non-small cell lung cancer (NSCLC) cell lines and in 25% (1/4) small cell lung cancer (SCLC) cell lines. The concordance between loss of expression and aberrant methylation of RASGRF2 was 86% (12/14). RASGRF2 expression was restored after treatment with the demethylating agent, 5-aza-2'-deoxycytidine in all four cell lines tested that downregulated RASGRF2 expression. Among primary NSCLC, RASGRF2 and RASSF1A methylation was observed in 34% (39/114) and 39% (44/114) of cases respectively, while it was observed in only 7% (4/57) and none of the corresponding non-malignant lung tissue. There is no correlation between RASGRF2 and RASSF1A methylation status. Both RASGRF2 and RASSF1A methylation did not associate with clinical characteristics. Frequent methylation and silencing of RASGRF2 in tumor cells may play an important role, different from that of RASSF1A, in the carcinogenesis of NSCLC.

Aged↗
PubMed2006

[Changes in autonomic function and EEG power during mental arithmetic task and their mutual relationship].

Meditation is a specific consciousness state in which deep relaxation and increased internalized attention coexist. Autonomic nervous activity during meditation was reported to be characterized by decreased sympathetic activity and increased parasympathetic activity. And concerning EEG power, slow alpha power and fast theta power increased during meditation. On the other hand, mental arithmetic (MA) tasks have been reported to induce an increase in blood pressure and heart rate with enhanced sympathetic activity. However, changes in autonomic nervous activity and EEG power during MA tasks and their mutual relationship have not been adequately studied. In the present study, we quantitatively analyzed the changes in autonomic nervous activity using heart rate variability (HRV) and EEG power during MA task in 30 healthy volunteers. MA task induced significant increases in normalized LF, LF/HF ratio (as a sympathetic index), and a decrease in normalized HF (as a parasympathetic index). On the other hand, significant decrease in EEG power (slow theta: 4-6 Hz and fast alpha: 10-13 Hz in the posterior region and fast theta: 6-8 Hz and slow alpha: 8-10 Hz in all the regions) were induced by MA task. Further evaluation of these changes showed a negative correlation between the change rates (with the control resting condition as the baseline) in fast alpha power and that in LF/HF. These results suggest that specific correlated relationships exist between the change in autonomic nervous activity and EEG power depending on the difference in mental task (i.e., meditation or MA).

Adult↗
PubMed2005

Hypoxia reduces constitutive and TNF-alpha-induced expression of monocyte chemoattractant protein-1 in human proximal renal tubular cells.

Chronic hypoxia has been reported to be associated with macrophage infiltration in progressive forms of kidney disease. Here, we investigated the regulatory effects of hypoxia on constitutive and TNF-alpha-stimulated expression of monocyte chemoattractant protein-1 (MCP-1) in cultured human proximal renal tubular cells (HPTECs). Hypoxia reduced constitutive MCP-1 expression at the mRNA and protein levels in a time-dependent fashion for up to 48 h. Hypoxia also inhibited MCP-1 up-regulation by TNF-alpha. Treatment with actinomycin D showed that hypoxic down-regulation of MCP-1 expression resulted mainly from a decrease in the transcription but not the mRNA stability. Immunoblot and immunofluorescence analyses revealed that treatment with hypoxia or an iron chelator, desferrioxamine, induced nuclear accumulation of hypoxia-inducible factor-1alpha (HIF-1alpha) in HPTECs. Desferrioxamine mimicked hypoxia in the reduction of MCP-1 expression. However, overexpression of a dominant negative form of HIF-1alpha did not abolish the hypoxia-induced reduction of MCP-1 expression in HPTECs. These results suggest that hypoxia is an important negative regulator of monocyte chemotaxis to the renal inflamed interstitium, by reducing MCP-1 expression partly via hypoxia-activated signals other than the HIF-1 pathway.

Cell Hypoxia↗
PubMed2005

Neuroprotective effect of oxidized galectin-1 in a transgenic mouse model of amyotrophic lateral sclerosis.

Abnormal accumulation of neurofilaments in motor neurons is a characteristic pathological finding in amyotrophic lateral sclerosis (ALS). Recently, we revealed that galectin-1, whose oxidized form has axonal regeneration-enhancing activity, accumulates in the neurofilamentous lesions in ALS. To investigate whether oxidized galectin-1 has a beneficial effect on ALS, oxidized recombinant human galectin-1 (rhGAL-1/ox) or physiological saline was injected into the left gastrocnemius muscle of the transgenic mice over-expressing a mutant copper/zinc superoxide dismutase (SOD1) with a substitution of histidine to arginine at position 46 (H46R SOD1). The H46R SOD1 transgenic mice, which represented a new animal model of familial ALS, were subsequently assessed for their disease onset, life span, duration of illness, and motor function. Furthermore, the number of remaining large anterior horn cells of spinal cords was also compared between the two groups. The results showed that administration of rhGAL-1/ox to the mice delayed the onset of their disease and prolonged the life of the mice and the duration of their illness. Motor function, as evaluated by a Rotarod performance, was improved in rhGAL-1/ox-treated mice. Significantly more anterior horn neurons of the lumbar and cervical cords were preserved in the mice injected with rhGAL-1/ox than in those injected with physiological saline. The study suggests that rhGAL-1/ox administration could be a new therapeutic strategy for ALS.

Age of Onset↗
PubMed2005

Aberrant methylation of FBN2 in human non-small cell lung cancer.

FBN2, a large modular extracellular matrix glycoprotein, is known to be a key component of human elastic fiber. A loss of FBN2 expression due to promoter methylation was recently identified in pancreatic cancer. We examined FBN2 expression by reverse transcription PCR and aberrant methylation of FBN2 by methylation specific PCR in lung cancer cell lines. Aberrant methylation of FBN2 was present in 55% (6 of 11) of non-small cell lung cancer (NSCLC) cell lines, but it absent in small cell lung cancer cell lines. The concordance between loss of expression and aberrant methylation of FBN2 was 88% (14 of 16) in the cell lines. FBN2 expression was restored after treatment with the demethylating agent, 5-aza-2'-deoxycytidine in all six cell lines tested that lacked FBN2 expression. Among primary NSCLC, 49% (62/126) of cases had FBN2 methylation, but only 7% (5/69) of the corresponding nonmalignant lung tissues had it. Although FBN2 methylation was detected even in patients with early stage disease, it occurred frequently in large tumors (p=0.022), with nodal metastasis (p=0.037), or with advanced stages of NSCLC (p=0.014). Methylation and silencing of FBN2 in tumor cells may play an important role in carcinogenesis, invasion, and metastasis of NSCLC.

Aged↗
PubMed2005

Synergistic effect of hypoxia and TNF-alpha on production of PAI-1 in human proximal renal tubular cells.

BACKGROUND: Chronic hypoxia has been newly proposed as a common mechanism of tubulointerstitial fibrosis in the progression of various chronic inflammatory renal diseases, where plasminogen activator inhibitor-1 (PAI-1) plays an important role in the accumulation of extracellular matrix (ECM) through inhibition of plasmin-dependent ECM degradation. In the present study, we investigated the presence of PAI-1 in renal tubular cells by immunostaining renal biopsy samples. We also closely examined the effects of hypoxia and tumor necrosis factor-alpha (TNF-alpha) on PAI-1 expression in cultured human proximal renal tubular cells (HPTECs). METHODS: Confluent cells growth-arrested in Dulbecco's modified Eagle's medium (DMEM) for 24 hours were exposed to hypoxia (1% O(2)) and/or TNF-alpha at 10 ng/mL for up to 48 hours. Amounts of PAI-1 protein and mRNA after stimulation were measured by enzyme-linked immunosorbent assay (ELISA) and TaqMan quantitative polymerase chain reaction (PCR) or cDNA array analysis, respectively, and compared to those in cells incubated under control conditions (18% O(2) without TNF-alpha). Hypoxia-inducible factor-1alpha (HIF-1alpha) was demonstrated by immunoblot and immunofluorescence analyses. Human PAI-1 promoter activity was estimated by luciferase reporter gene assay. RESULTS: In crescentic glomerulonephritis, clusters of proximal tubules were specifically stained for PAI-1. cDNA array analysis identified PAI-1 as a major gene highly induced by hypoxia in HPTECs. Treatment of 24 hours with hypoxia, TNF-alpha, and their combination induced a 2.8-fold, a 1.8-fold, and a 4.6-fold increase in PAI-1 protein secretion, and produced a 3.6-fold, a 3.3-fold, and a 12.1-fold increase at the PAI-1 mRNA level, respectively. Immunoblot analysis and immunocytochemistry revealed that hypoxia-inducible factor-1alpha (HIF-1alpha) was markedly accumulated in the cell lysates and exclusively translocated to nuclei after 16 hours' exposure of HPTECs to hypoxia but not to TNF-alpha. Luciferase reporter gene assay showed that hypoxia, TNF-alpha, and their combination increased PAI-1 transcription activity by 1.8-fold, 1.4-fold, and 2.2-fold, respectively. A dominant-negative form of HIF-1alpha significantly suppressed PAI-1 transcription activity induced by hypoxia. Inhibition of nuclear factor-kappaB (NF-kappaB) caused a moderate decrease in PAI-1 production under hypoxia. CONCLUSION: Hypoxia induces PAI-1 expression via remarkable nuclear accumulation of HIF-1alpha and partially via NF-kappaB activation in HPTECs. TNF-alpha can synergistically enhance this hypoxia-induced PAI-1 expression.

Antineoplastic Agents↗
PubMed2005

[Effects of hypoxia and tumor necrosis factor-alpha on production of plasminogen activator inhibitor-1 in human proximal renal tubular cells].

Chronic hypoxia has been newly proposed as a common mechanism of tubulointerstitial fibrosis in the progression of various chronic inflammatory renal diseases, where PAI-1 plays an important role in the accumulation of extracellular matrix (ECM) through inhibition of plasmin-dependent ECM degradation. In the present study, we investigated the presence of PAI-1 in renal tubular cells by immunostaining renal biopsy samples. We also closely examined the effects of hypoxia and TNF-alpha on PAI-1 expression in cultured human proximal renal tubular cells (HRCs). Confluent cells growth-arrested in DMEM for 24h were exposed to hypoxia (1% O2) and/or TNF-alpha at 10 ng/ml for 24 hours. Amounts of PAI-1 protein and mRNA after stimulation were measured by ELISA and TaqMan quantitative PCR, respectively and compared to those in cells incubated under control conditions (18% O2 without TNF-alpha). HIF-1alpha was demonstrated by immunoblot analysis. In crescentic glomerulonephritis, clusters of proximal tubules were specifically stained for PAI-1. Treatment of 24 hours with hypoxia, TNF-alpha and their combination induced a 2.7-fold, a 1.8-fold, and a 4.6-fold increase in PAI-1 protein secretion, and produced a 3.6-fold, a 3.3-fold, and a 12.1-fold increase at the PAI-1 mRNA level, respectively. Immunoblot analysis revealed that hypoxia-inducible factor-1alpha (HIF-1alpha) was markedly accumulated in the nuclear fraction after 16-hours exposure of HPTECs to hypoxia but not to TNF-alpha. In conclusion, hypoxia induces PAI-1 expression via remarkable nuclear accumulation of HIF-1alpha in HRCs. TNF-alpha can enhance this hypoxia-induced PAI-1 expression.

Cells, Cultured↗
PubMed2005

Multimodality therapy and significance of serum CYFRA21-1 for thymic carcinoma.

Thymic carcinoma is a rare mediastinal neoplasm with a poor prognosis due to delayed diagnosis and highly malignant behavior. To evaluate 7 serum tumor markers and the outcome of treatment, 11 stage III-IVb thymic carcinomas undergoing multimodality treatment were reviewed. High levels of serum CYFRA21-1 were detected in 5 patients (45%) and correlated with the progression of disease. Of the patients, 6 underwent surgery. The median survival time was 38.4 months, and the 5-year survival rate was 15.6%. The metastatic stage (IVb) and treatment without resection were significantly associated with poorer overall survival (p=0.0034 and p=0.0041, respectively). Our data demonstrated that serum CYFRA21-1 may represent a potential new biomarker in thymic carcinoma. Stage may provide a basis for prognosis in stage III-IVb thymic carcinoma, and resection is one of the most important parts of multimodality treatment for advanced thymic carcinoma. Effective neoadjuvant treatment is therefore essential.

Aged↗
PubMed2005

Phase I study of vinorelbine plus gemcitabine as third-line chemotherapy for refractory non-small cell lung cancer.

For non-small cell lung cancer (NSCLC), which is refractory for both platinum-based chemotherapy and docetaxel, no standard regimen has yet been established. We conducted a phase I study of a combination of vinorelbine and gemcitabine as third-line chemotherapy for refractory NSCLC to determine both the maximum tolerated dose (MTD) and the recommended dose (RD). Twenty patients with NSCLC refractory for both platinum and docetaxel were enrolled, and all patients were eligible for this phase I study. Cohorts of three to seven patients received vinorelbine at doses ranging from 20 to 25 mg/m(2), and gemcitabine at doses ranging from 600 to 1000 mg/m(2), on days 1 and 8 every 3 weeks. The dose-limiting toxicities were treatment delay, serum gammaGTP elevation, diarrhea and cerebral infarction, which were resolved without serious sequela, and there was no treatment-related death. The MTD was vinorelbine at 25 mg/m(2) and gemcitabine at 1000 mg/m(2) and the RD was vinorelbine at 25 mg/m(2) and gemcitabine at 800 mg/m(2). The median overall survival time was 6.8 months for all 20 patients eligible. As third-line chemotherapy, the combination of vinorelbine and gemcitabine was feasible and promising for NSCLC which is refractory for both platinum and docetaxel.

Adult↗
PubMed2005

[Increased expression of plasminogen activator inhibitor-1 in hypoxic renal injury and its pathological significance in progression of advanced renal disease].

Chronic hypoxia has been newly proposed as a common mechanism of progressive renal fibrosis where PAI-1 plays important roles in the accumulation of extracellular matrix (ECM) through inhibition of plasmin-dependent ECM degradation. Hypoxia is also presumably associated with macrophage recruitment and angiogenesis that form fibrotic lesions. In the present study, we examined the effects of hypoxia and TNF-alpha on PAI-1, MCP-1 and VEGF expression in cultured human proximal renal tubular cells (HPTECs). We also investigated the presence of PAI-1 in renal tubular cells by immunostaining renal biopsy samples and measuring urinary PAI-1 levels in different kidney diseases. cDNA array analysis identified PAI-1 as a major gene highly induced by hypoxia in HPTECs. Hypoxia, TNF-alpha and their combination induced a 2.8-fold, a 1.8-fold, and a 4.6-fold increase in PAI-1 protein secretion, and produced a 3.6-fold, a 3.3-fold, and a 12.1-fold increase at the PAI-1 mRNA level, respectively. Similar results were confirmed by luciferase assay. Immunoblot analysis and immunocytochemistry revealed that hypoxia-inducible factor-1alpha (HIF-1alpha) was markedly accumulated in nuclei after 16-hours of hypoxia. Hypoxia reduced basal and TNF-alpha-stimulated MCP-1 expression, while it induced VEGF expression in HPTECs. In crescentic glomerulonephritis (CrGN) or diabetic nephropathy (DN) with severe proteinuria, clusters of proximal tubules and a part of the fibrotic interstitium were specifically stained for PAI-1, while no stainings were found in minor glomerular abnormality or minimal change nephrotic syndrome. Urinary PAI-1 levels were significantly higher in CrGN and DN than in healthy controls. In DN, urinary TNF-alpha levels were significantly correlated with urinary PAI-1 levels. PAI-1 induced by hypoxia and inflammation may contribute to further progression of advanced kidney disease, CrGN or DN. Hypoxia together with inflammation may also be involved in promotion of renal fibrosis in part by modulating MCP-1 and VEGF expression.

Cell Hypoxia↗
PubMed2005

Aberrant methylation: common in thymic carcinomas, rare in thymomas.

Thymic carcinoma, which is a rare epithelial neoplasm of the thymus gland, is different from thymoma in its clinical and pathological features. To clarify the mechanism underlying the aggressive behavior of thymic carcinoma, we examined the clinicopathologic features, aberrant methylation patterns of the tumor suppressor genes, and epidermal growth factor receptor (EGFRs) mutation in both thymic carcinomas and thymomas. Clinical data of 11 thymic cancers and 13 thymomas were reviewed. Resected samples of 5 thymic cancers and 6 thymomas selected from 24 cases were used for methylation and mutation studies. Positive tumor markers were more frequent in thymic cancers than in thymomas (p=0.0233), and the methylation index, which reflects the overall methylation pattern, was significantly higher in thymic carcinomas (p=0.0053). No tumors showed a mutation of EGFR, KRAS, and HER2. Thymic carcinoma is distinct from thymoma not only with respect to clinicopathological features, but also aberrant methylation patterns of the tumor suppressor genes.

Adult↗
PubMed2004

A human granin-like neuroendocrine peptide precursor (proSAAS) immunoreactivity in tau inclusions of Alzheimer's disease and parkinsonism-dementia complex on Guam.

The deposition of tau inclusions is one of the neuropathological hallmarks in neurodegenerative disorders with dementia. We have reported that the N-terminal fragment of a human granin-like neuroendocrine peptide precursor (N-proSAAS) is accumulated in Pick bodies. However, it is unknown whether N-proSAAS is widely accumulated in tau inclusions in other tauopathies. Here, we performed an immunohistochemical examination using antibodies against both the N- and C-terminal sequence of proSAAS in the brains of patients with Alzheimer's disease and parkinsonism-dementia complex on Guam. The antibody against N-proSAAS immunostained neurofibrillary tangles and neuritic plaques in both diseases, whereas the antibody against the C-terminal sequence of proSAAS did not. The results of the present study suggest that N-proSAAS or proSAAS-like molecules were trapped within the tau fibrils and accumulated in tau inclusions.

Aged↗
PubMed2004

DNA polymerase theta is preferentially expressed in lymphoid tissues and upregulated in human cancers.

DNA polymerase theta (Pol theta) is a recently identified family A polymerase that contains an intrinsic helicase domain. Drosophila Pol theta mutants are hypersensitive to bifunctional DNA crosslinking agents and exhibit an elevated frequency of spontaneous chromosomal aberrations, suggesting a role for Pol theta in repair of DNA interstrand crosslinks and in the general maintenance of genome stability. To investigate a possible involvement of Pol theta in tumorigenesis, we have examined its expression in various normal and malignant tissues. Paired tumor and adjacent nontumorous tissues from patients with lung (n = 27), stomach (n = 28) and colon (n = 26) cancer, as well as 26 normal human tissues, were examined for Pol theta expression by RT-PCR, Northern or Western blot analysis. Pol theta was predominantly expressed in primary lymphoid organs including the fetal liver, thymus and bone marrow where lymphocyte progenitors undergo V(D)J rearrangements of their antigen receptor genes. In addition, Pol theta expression was upregulated in germinal center B cells, in which class switch recombination of the immunoglobulin genes occurs. Examination of Pol theta expression in matched cancer specimens revealed that Pol theta was barely detectable in the nontumorous tissues but was upregulated in 17 of 27 (63%) lung, 11 of 28 (39%) stomach and 20 of 26 (77%) colon cancers. Moreover, patients with high levels of Pol theta expression had a significantly poorer clinical outcome compared with those expressing low levels of Pol theta. These results implicate that Pol theta may have a specialized function in lymphocytes and that its overexpression may contribute to tumor progression.

Adult↗
PubMed2004

Liver-type fatty acid-binding protein is highly expressed in intestinal metaplasia and in a subset of carcinomas of the stomach without association with the fatty acid synthase status in the carcinoma.

OBJECTIVE: To investigate the relation of liver-type fatty-acid-binding protein (L-FABP) expression to the clinicopathological characteristics or the fatty acid synthase status of gastric cancers. METHODS: L-FABP expression was examined immunohistochemically in 667 gastric cancers, 60 gastric adenomas, and non-neoplastic epithelium contiguous with cancer tissue including normal foveolae, intestinal metaplasia, regenerative epithelium, and gastric glands. RESULTS: L-FABP was positive in 38% (high in 9% and low in 29%) of gastric cancers. It occurred preferentially in papillary carcinomas, female cases, and in patients under 50 years. In gastric cancers, L-FABP expression had no intimate correlation with the FAS status, and it showed no relationship with prognosis and cancer progression as indicated by venous and lymphatic permeation, and nodal or hepatic metastasis. Gastric tubular adenomas mainly revealed low (22%) expression of L-FABP while intestinal metaplasia showed the most frequent (>95%) and intense L-FABP expression. Normal foveolae and gastric glands showed no or less L-FABP expression. CONCLUSIONS: L-FABP is highly and intensely expressed in metaplasia and in a subset of gastric adenocarcinomas, without association with progression, prognosis and fatty acid synthase status of the carcinoma.

Adenocarcinoma↗