タイセイ ハイ サイボウ ユライ ノ シンキン サイボウ ニオケル ナトリウム リニョウ ペプチド ト チュウスウ シンケイケイ ニオケル ナトリウム リニョウ ペプチド ジュヨウタイ ニツイテ 1) サル Eサイボウ カラ ブンカサセタ シンキン サイボウ ハ in vitro デ ナトリウム リニョウ ペプチド ヲ ハツゲンスル 2) サル ノウカンブ ニオケル Aガタ ナトリウム リニョウ ペプチド ジュヨウタイ ノ メンエキ ソシキ カガクホウ ニヨル ブンプズ

学位授与機関：　滋賀医科大学　博士（医学）第585号　平成21年3月25日Biochem. Biophys. Res. Commun.340(2), p.689-695

Natriuretic peptides in embryonic stem cell-derived cardiomyocytes and their receptors in the CNS.

The natriuretic peptides (NPs) are a family of related hormones that play important roles inthe cardiovascular homeostasis, cell growth and neuroendocrine functions. Recently, theyhave emerged as potentially important clinical biomarkers in heart failure. The heartsecretes two major natriuretic peptides: atrial natriuretic peptide (ANP) and brainnatriuretic peptide (BNP), while C-type natriuretic peptide (CNP) is mainly secretedfrom the brain and blood vessels. The physiological effects of NPs are initiated bybinding to natriuretic peptide receptors (NPRs), which are widely distributed inseveral organs. This review describes: the expression of natriuretic peptides in thecardiomyocytes differentiated from ES cells and their role in the cardiomyocytedevelopment. We also describe the detailed distribution of NPRs in the centralnervous system and their possible functions in various brain regions

Altered Regulation of the Glucose Transporter GLUT3 in PRDX1 Null Cells Caused Hypersensitivity to Arsenite

Targeting tumour metabolism through glucose transporters is an attractive approach. However, the role these transporters play through interaction with other signalling proteins is not yet defined. The glucose transporter SLC2A3 (GLUT3) is a member of the solute carrier transporter proteins. GLUT3 has a high affinity for D-glucose and regulates glucose uptake in the neurons, as well as other tissues. Herein, we show that GLUT3 is involved in the uptake of arsenite, and its level is regulated by peroxiredoxin 1 (PRDX1). In the absence of PRDX1, GLUT3 mRNA and protein expression levels are low, but they are increased upon arsenite treatment, correlating with an increased uptake of glucose. The downregulation of GLUT3 by siRNA or deletion of the gene by CRISPR cas-9 confers resistance to arsenite. Additionally, the overexpression of GLUT3 sensitises the cells to arsenite. We further show that GLUT3 interacts with PRDX1, and it forms nuclear foci, which are redistributed upon arsenite exposure, as revealed by immunofluorescence analysis. We propose that GLUT3 plays a role in mediating the uptake of arsenite into cells, and its homeostatic and redox states are tightly regulated by PRDX1. As such, GLUT3 and PRDX1 are likely to be novel targets for arsenite-based cancer therapy

Expression and Localization of Mitochondrial Ferritin mRNA in Alzheimer's Disease Cerebral Cortex

Mitochondrial ferritin (MtF) has been identified as a novel ferritin encoded by an intron-lacking gene with specific mitochondrial localization located on chromosome 5q23.1. MtF has been associated with neurodegenerative disorders such as Friedreich ataxia and restless leg syndrome. However, little information is available about MtF in Alzheimer's disease (AD). In this study, therefore, we investigated the expression and localization of MtF messenger RNA (mRNA) in the cerebral cortex of AD and control cases using real-time polymerase chain reaction (PCR) as well as in situ hybridization histochemistry. We also examined protein expression using western-blot assay. In addition, we used in vitro methods to further explore the effect of oxidative stress and β-amyloid peptide (Aβ) on MtF expression. To do this we examined MtF mRNA and protein expression changes in the human neuroblastoma cell line, IMR-32, after treatment with Aβ, H2O2, or both. The neuroprotective effect of MtF on oxidative stress induced by H2O2 was measured by MTT assay. The in situ hybridization studies revealed that MtF mRNA was detected mainly in neurons to a lesser degree in glial cells in the cerebral cortex. The staining intensity and the number of positive cells were increased in the cerebral cortex of AD patients. Real-time PCR and western-blot confirmed that MtF expression levels in the cerebral cortex were significantly higher in AD cases than that in control cases at both the mRNA and the protein level. Cell culture experiments demonstrated that the expression of both MtF mRNA and protein were increased by treatment with H2O2 or a combination of Aβ and H2O2, but not with Aβ alone. Finally, MtF expression showed a significant neuroprotective effect against H2O2-induced oxidative stress (p<0.05). The present study suggests that MtF is involved in the pathology of AD and may play a neuroprotective role against oxidative stress

Genome-wide differential expression profiling of long non-coding RNAs in FOXA2 knockout iPSC-derived pancreatic cells

Abstract Background Our recent studies have demonstrated the crucial involvement of FOXA2 in the development of human pancreas. Reduction of FOXA2 expression during the differentiation of induced pluripotent stem cells (iPSCs) into pancreatic islets has been found to reduce α-and β-cell masses. However, the extent to which such changes are linked to alterations in the expression profile of long non-coding RNAs (lncRNAs) remains unraveled. Methods Here, we employed our recently established FOXA2-deficient iPSCs (FOXA2 −/− iPSCs) to investigate changes in lncRNA profiles and their correlation with dysregulated mRNAs during the pancreatic progenitor (PP) and pancreatic islet stages. Furthermore, we constructed co-expression networks linking significantly downregulated lncRNAs with differentially expressed pancreatic mRNAs. Results Our results showed that 442 lncRNAs were downregulated, and 114 lncRNAs were upregulated in PPs lacking FOXA2 compared to controls. Similarly, 177 lncRNAs were downregulated, and 59 lncRNAs were upregulated in islet cells lacking FOXA2 compared to controls. At both stages, we observed a strong correlation between lncRNAs and several crucial pancreatic genes and TFs during pancreatic differentiation. Correlation analysis revealed 12 DE-lncRNAs that strongly correlated with key downregulated pancreatic genes in both PPs and islet cell stages. Selected DE-lncRNAs were validated using RT-qPCR. Conclusions Our data indicate that the observed defects in pancreatic islet development due to the FOXA2 loss is associated with significant alterations in the expression profile of lncRNAs. Therefore, our findings provide novel insights into the role of lncRNA and mRNA networks in regulating pancreatic islet development, which warrants further investigations. Video Abstrac

Correction to: Enhanced differentiation of human pluripotent stem cells into pancreatic progenitors co-expressing PDX1 and NKX6.1

The original article [1] contains a number of small errors which the authors would like to clarify

Enhanced differentiation of human pluripotent stem cells into pancreatic progenitors co-expressing PDX1 and NKX6.1

Abstract Background Pancreatic progenitors (PPs) co-expressing the two transcription factors (TFs) PDX1 and NKX6.1 are recognized as the indispensable precursors of functional pancreatic β cells. Here, we aimed to establish an efficient protocol for maximizing generation of PDX1+/NKX6.1+ PPs from human pluripotent stem cells (hPSCs). Methods In order to enhance the PDX1+/NKX6.1+ population, we manipulated in vitro culture conditions during differentiation by dissociating densely formed endodermal cells and re-plating them at different densities. These dissociated cells were subjected to an augmented duration of retinoid and fibroblast growth factor (FGF)10 signaling to induce higher PDX1 and NKX6.1 expression. Results Our optimized protocol dramatically increased the expression of NKX6.1, leading to an increase in the proportion of PDX1+/NKX6.1+ progenitors (~90%) in monolayer, higher than the previously published protocols, as well as upregulated key TFs controlling pancreatic development. The improved efficiency of pancreatic differentiation was complemented by an inhibited hepatic specification and an increased proliferation of NKX6.1+ cells. Interestingly, we were able to enrich a novel PDX1–/NKX6.1+ population by manipulating the re-plating density; these oriented themselves in three-dimensional clusters. Further differentiation validated the ability of our PDX1+/NKX6.1+ progenitors to generate NGN3+ endocrine progenitors. Conclusions We provide a novel technique that facilitates appropriate cellular rearrangement in monolayer culture to yield a high proportion of PDX1+/NKX6.1+ PPs with an elevated self-replicating capacity, thereby aiding scalable production of functional β cells from hPSCs in vitro. Our innovative method also enriches a novel NKX6.1+/PDX1– population, with characteristics of proposed endocrine precursors, allowing further studies on deciphering routes to β-cell development

Fourier-Transform Infrared Imaging Spectroscopy and Laser Ablation -ICPMS New Vistas for Biochemical Analyses of Ischemic Stroke in Rat Brain

Objective: Stroke is the main cause of adult disability in the world, leaving more than half of the patients dependent on daily assistance. Understanding the post-stroke biochemical and molecular changes are critical for patient survival and stroke management. The aim of this work was to investigate the photo-thrombotic ischemic stroke in male rats with particular focus on biochemical and elemental changes in the primary stroke lesion in the somatosensory cortex and surrounding areas, including the corpus callosum.Materials and Methods: FT-IR imaging spectroscopy and LA-ICPMS techniques examined stroke brain samples, which were compared with standard immunohistochemistry studies.Results: The FTIR results revealed that in the lesioned gray matter the relative distribution of lipid, lipid acyl and protein contents decreased significantly. Also at this locus, there was a significant increase in aggregated protein as detected by high-levels Aβ1-42. Areas close to the stroke focus experienced decrease in the lipid and lipid acyl contents associated with an increase in lipid ester, olefin, and methyl bio-contents with a novel finding of Aβ1-42 in the PL-GM and L-WM. Elemental analyses realized major changes in the different brain structures that may underscore functionality.Conclusion: In conclusion, FTIR bio-spectroscopy is a non-destructive, rapid, and a refined technique to characterize oxidative stress markers associated with lipid degradation and protein denaturation not characterized by routine approaches. This technique may expedite research into stroke and offer new approaches for neurodegenerative disorders. The results suggest that a good therapeutic strategy should include a mechanism that provides protective effect from brain swelling (edema) and neurotoxicity by scavenging the lipid peroxidation end products

Neuropathy of type 1 diabetes in the Arab world: A systematic review and meta-analysis

Abstract AimsAlthough type 1 diabetes (T1D) is a common disease in the Arab nations, there is no data available on the prevalence of peripheral neuropathy (PN) among T1D subjects in Arab countries. The aim of this study is to analyze the prevalence of PN in T1D subjects via published literature and to draw attention to the dearth of the published work in this serious complication of T1D. MethodsA meta-analysis was performed on studies representing different Arab countries with a total number of 2243 T1D subjects. ResultsThe pooled prevalence of PN among T1D subjects in the Arab region was estimated as 18% with 95% confidence intervals (CI): 0.09–0.34. The PN prevalence was significantly higher in the >16-yr age group, with 59.1% (95% CI: 0.45–0.72) compared to 9.5% (95% CI: 0.05–0.19) in the 16years) with T1D are affected more with PN than younger age Arab people (<16years). PN is more frequently present in Arab subjects with a longer duration of T1D diabetes than in those with shorter duration.This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sector