Publications by authors named "Fumiko Shimizu"

20 Publications

  • Page 1 of 1

A CRAF/glutathione-S-transferase P1 complex sustains autocrine growth of cancers with and mutations.

Proc Natl Acad Sci U S A 2020 08 27;117(32):19435-19445. Epub 2020 Jul 27.

Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY 10461.

The Ras/RAF/MEK/ERK pathway is an essential signaling cascade for various refractory cancers, such as those with mutant (m) and (m). However, there are unsolved ambiguities underlying mechanisms for this growth signaling thereby creating therapeutic complications. This study shows that a vital component of the pathway CRAF is directly impacted by an end product of the cascade, glutathione transferases (GST) P1 (GSTP1), driving a previously unrecognized autocrine cycle that sustains proliferation of m and m cancer cells, independent of oncogenic stimuli. The CRAF interaction with GSTP1 occurs at its N-terminal regulatory domain, CR1 motif, resulting in its stabilization, enhanced dimerization, and augmented catalytic activity. Consistent with the autocrine cycle scheme, silencing GSTP1 brought about significant suppression of proliferation of m and m cells in vitro and suppressed tumorigenesis of the xenografted m tumor in vivo. GSTP1 knockout mice showed significantly impaired carcinogenesis of m colon cancer. Consequently, hindering the autocrine loop by targeting CRAF/GSTP1 interactions should provide innovative therapeutic modalities for these cancers.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1073/pnas.2000361117DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7430992PMC
August 2020

Chromatin-informed inference of transcriptional programs in gynecologic and basal breast cancers.

Nat Commun 2019 09 25;10(1):4369. Epub 2019 Sep 25.

Computational & Systems Biology Program, Memorial Sloan Kettering Cancer Center, New York, NY, USA.

Chromatin accessibility data can elucidate the developmental origin of cancer cells and reveal the enhancer landscape of key oncogenic transcriptional regulators. We develop a computational strategy called PSIONIC (patient-specific inference of networks informed by chromatin) to combine chromatin accessibility data with large tumor expression data and model the effect of enhancers on transcriptional programs in multiple cancers. We generate a new ATAC-seq data profiling chromatin accessibility in gynecologic and basal breast cancer cell lines and apply PSIONIC to 723 patient and 96 cell line RNA-seq profiles from ovarian, uterine, and basal breast cancers. Our computational framework enables us to share information across tumors to learn patient-specific TF activities, revealing regulatory differences between and within tumor types. PSIONIC-predicted activity for MTF1 in cell line models correlates with sensitivity to MTF1 inhibition, showing the potential of our approach for personalized therapy. Many identified TFs are significantly associated with survival outcome. To validate PSIONIC-derived prognostic TFs, we perform immunohistochemical analyses in 31 uterine serous tumors for ETV6 and 45 basal breast tumors for MITF and confirm that the corresponding protein expression patterns are also significantly associated with prognosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41467-019-12291-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6761109PMC
September 2019

A study of the prebiotic effect of lactulose at low dosages in healthy Japanese women.

Biosci Microbiota Food Health 2019 29;38(2):69-72. Epub 2018 Dec 29.

Life Science for Living System, Graduate School, Showa Women's University, 1-7 Taishidou, Setagaya-ku, Tokyo 154-8533, Japan.

To investigate the prebiotic effect of lactulose at low dosages, we assessed changes in defaecation frequency following ingestion of 1, 2, or 3 g/day of lactulose for 2 weeks. Each test was carried out after a 2-week washout period. This was an open-label, before-after trial that enrolled 26 healthy Japanese women. The defaecation frequency, number of defaecation days, and number of faecal bifidobacteria increased significantly compared with before ingestion of 1, 2, and 3 g/day of lactulose. These results suggest that even 1 g/day of lactulose could have a prebiotic effect.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.12938/bmfh.18-013DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6502711PMC
December 2018

Comparison of plasma levels of different species of trans fatty acids in Japanese male patients with acute coronary syndrome versus healthy men.

Atherosclerosis 2019 05 13;284:173-180. Epub 2019 Mar 13.

The International Projects on Food and Health (NPO), Tokyo, Japan.

Background And Aims: It remains unclear how trans fatty acid (TFA) at low-level intake affect lipid levels and the development of acute coronary syndrome (ACS). The study aimed to investigate how plasma TFA composition differs between male patients with ACS and healthy men.

Methods: Plasma fatty acid (FA) composition (as determined by gas chromatography) was analyzed in ACS patients on hospital admission and compared to that of age-adjusted healthy men.

Results: Total FA and TFA levels were similar between ACS and control subjects. Palmitelaidic acid, ruminant-derived TFA (R-TFA), levels were lower in ACS patients (0.17 ± 0.06 vs. 0.20 ± 0.06 of total FA, in ACS and control, respectively, p<0.01), and were significantly directly associated with HDL cholesterol (HDL-C) (rho = 0.269) and n-3 polyunsaturated FA (n-3 PUFA) (rho = 0.442). Linoleic trans isomers (total C18:2 TFA), primary industrially-produced TFA (IP-TFAs), were significantly higher in ACS patients (0.68 ± 0.17 vs. 0.60 ± 0.20 of total FA, in ACS and control, respectively). Total trans-C18:1 isomers were comparable between ACS and control. Differences between ACS and controls in C18:1 trans varied by specific C18:1 trans species. Absolute concentrations of trans-C18:2 isomers were significantly directly associated with LDL-C and non-HDL-C in ACS men. The ACS patients showed significantly lower levels of both n-6 and n-3 PUFA (i.e., eicosapentaenoic, docosahexaenoic and arachidonic acids).

Conclusions: There were several case-control differences in specific TFA that could potential affect risk for ACS. Japanese ACS patients, especially middle-aged patients, may consume less R-TFA.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.atherosclerosis.2019.02.025DOI Listing
May 2019

[Tryptophan Metabolites in Plasma of Patients with Depression].

Brain Nerve 2018 Sep;70(9):1025-1031

NPO "International Projects on Food and Health".

There are two major pathways in tryptophan metabolism. The serotonin pathway mediates mood, anxiety, memory, cognition, and is impaired in depression. The kynurenine pathways are involved in immunity, inflammation, muscle movement, and mental health. We investigated changes in tryptophan metabolites in plasma from depressed patients. Plasma levels of serotonin were very low or undetectable in patients with monopolar depression. 5-hydroxyindole acetic acid (5-HIAA)/tryptophan ratios or kynurenine/tryptophan ratios were not different between healthy controls and depressive patients, indicating rapid degradation of serotonin into 5-HIAA. However, there were no significant changes in kynurenine levels in depressed patients. It is important to examine the roles of tryptophan metabolites in monopolar and bipolar depression since both require different treatments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.11477/mf.1416201123DOI Listing
September 2018

Difficult Management of a Double-Lumen Endotracheal Tube and Difficult Ventilation during Robotic Thymectomy with Carbon Dioxide Insufflation.

Case Rep Surg 2017 26;2017:3403045. Epub 2017 Apr 26.

Department of Anesthesiology and Resuscitology, Shinshu University School of Medicine, Matsumoto, Japan.

Robotic surgery with carbon dioxide (CO) insufflation to the thorax is frequently performed to gain a better operative field of view, although its intraoperative complications have not yet been discussed in detail. We treated two patients with difficult ventilation caused by distal migration of a double-lumen endotracheal tube (DLT) during robotic thymectomy. In the first case, migration of the DLT during one-lung ventilation (OLV) occurred after CO insufflation to the bilateral thoraxes was started. Oxygenation rapidly deteriorated because dependent lung expansion was restricted by CO insufflation. In the second case, migration of the DLT during OLV occurred while CO insufflation to a unilateral thorax and mediastinum was performed. In both cases, once migration of the DLT during OLV occurred with CO insufflation, readjusting the DLT became very difficult because our manipulation of bronchofiberscopy was prevented by the robot arms located above the patient's head and because deformation of the trachea/bronchus induced by CO insufflation caused a poor image of the bronchofiberscopic view. Thus, during robotic-assisted thoracoscopic surgery with CO insufflation, since there is a potential risk of difficult ventilation with a DLT and since readjustment of the DLT is very difficult, discontinuing CO insufflation and switching to double-lung ventilation are needed in such a situation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1155/2017/3403045DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5424183PMC
April 2017

The epichaperome is an integrated chaperome network that facilitates tumour survival.

Nature 2016 Oct 5;538(7625):397-401. Epub 2016 Oct 5.

Program in Chemical Biology, Sloan Kettering Institute, New York, New York 10065, USA.

Transient, multi-protein complexes are important facilitators of cellular functions. This includes the chaperome, an abundant protein family comprising chaperones, co-chaperones, adaptors, and folding enzymes-dynamic complexes of which regulate cellular homeostasis together with the protein degradation machinery. Numerous studies have addressed the role of chaperome members in isolation, yet little is known about their relationships regarding how they interact and function together in malignancy. As function is probably highly dependent on endogenous conditions found in native tumours, chaperomes have resisted investigation, mainly due to the limitations of methods needed to disrupt or engineer the cellular environment to facilitate analysis. Such limitations have led to a bottleneck in our understanding of chaperome-related disease biology and in the development of chaperome-targeted cancer treatment. Here we examined the chaperome complexes in a large set of tumour specimens. The methods used maintained the endogenous native state of tumours and we exploited this to investigate the molecular characteristics and composition of the chaperome in cancer, the molecular factors that drive chaperome networks to crosstalk in tumours, the distinguishing factors of the chaperome in tumours sensitive to pharmacologic inhibition, and the characteristics of tumours that may benefit from chaperome therapy. We find that under conditions of stress, such as malignant transformation fuelled by MYC, the chaperome becomes biochemically 'rewired' to form a network of stable, survival-facilitating, high-molecular-weight complexes. The chaperones heat shock protein 90 (HSP90) and heat shock cognate protein 70 (HSC70) are nucleating sites for these physically and functionally integrated complexes. The results indicate that these tightly integrated chaperome units, here termed the epichaperome, can function as a network to enhance cellular survival, irrespective of tissue of origin or genetic background. The epichaperome, present in over half of all cancers tested, has implications for diagnostics and also provides potential vulnerability as a target for drug intervention.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature19807DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5283383PMC
October 2016

Concentrations of various tryptophan metabolites are higher in patients with diabetes mellitus than in healthy aged male adults.

Diabetol Int 2017 Mar 9;8(1):69-75. Epub 2016 Aug 9.

NPO "International Projects on Food and Health", Sumidaku Ishiwara 1-30-6-802, Tokyo, 130-0011 Japan.

Tryptophan metabolites in plasma samples from 20 male subjects with type 2 diabetes mellitus (T2DM) and 20 nondiabetic reference males were analyzed by ultra high performance liquid chromatography. Tryptophan levels in the diabetic subjects were significantly lower than those in nondiabetic subjects. The concentrations of 5-hydroxytryptophan, 5-hydroxyindoleacetic acid, kynurenic acid, 3-hydroxykynurenine, 3-hydroxyanthranilic acid, and xanthurenic acid were found to be higher in the diabetic patients. When the diabetic patients were divided into higher- and lower-tryptophan groups, the concentrations of 5-hydroxytryptophan, indole-3-acetic acid, kynurenine, 5-hydroxykynurenine, and kynurenic acid were found to be higher in the diabetic patients with higher tryptophan levels. However, diabetic patients with lower plasma tryptophan levels had higher levels of 5-hydroxyindoleacetic acid than the patients with higher tryptophan levels. These results suggest that tryptophan was metabolized more in T2DM patients than in nondiabetic subjects. In the kynurenine pathway, the degradation of tryptophan seems to be accelerated in patients with higher plasma levels of tryptophan than in patients with lower levels of tryptophan. In the serotonin pathway, when the level of tryptophan is low, the conversion of serotonin to 5-hydroxyindoleacetic acid appears to be accelerated. In conclusion, our results suggest that T2DM patients may be exposed to stress constantly.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s13340-016-0282-yDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6224928PMC
March 2017

Molecular and Clinical Effects of Notch Inhibition in Glioma Patients: A Phase 0/I Trial.

Clin Cancer Res 2016 Oct 6;22(19):4786-4796. Epub 2016 May 6.

Department of Neurology, Memorial Sloan Kettering Cancer Center, New York, New York.

Purpose: High-grade gliomas are associated with a dismal prognosis. Notch inhibition via the gamma-secretase inhibitor RO4929097 has emerged as a potential therapeutic option based on modulation of the cancer-initiating cell (CIS) population and a presumed antiangiogenic role.

Experimental Design: In this phase 0/I trial, 21 patients with newly diagnosed glioblastoma or anaplastic astrocytoma received RO4929097 combined with temozolomide and radiotherapy. In addition to establishing the MTD, the study design enabled exploratory studies evaluating tumor and brain drug penetration and neuroimaging parameters. We also determined functional effects on the Notch pathway and targeting of CISs through analysis of tumor tissue sampled from areas with and without blood-brain barrier disruption. Finally, recurrent tumors were also sampled and assessed for Notch pathway responses while on treatment.

Results: Treatment was well tolerated and no dose-limiting toxicities were observed. IHC of treated tumors showed a significant decrease in proliferation and in the expression of the Notch intracellular domain (NICD) by tumor cells and blood vessels. Patient-specific organotypic tumor explants cultures revealed a specific decrease in the CD133 CIS population upon treatment. Perfusion MRI demonstrated a significant decrease in relative plasma volume after drug exposure. Gene expression data in recurrent tumors suggested low Notch signaling activity, the upregulation of key mesenchymal genes, and an increase in VEGF-dependent angiogenic factors.

Conclusions: The addition of RO4929097 to temozolomide and radiotherapy was well tolerated; the drug has a variable blood-brain barrier penetration. Evidence of target modulation was observed, but recurrence occurred, associated with alterations in angiogenesis signaling pathways. Clin Cancer Res; 22(19); 4786-96. ©2016 AACR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5050072PMC
http://dx.doi.org/10.1158/1078-0432.CCR-16-0048DOI Listing
October 2016

Cox-2-derived PGE2 induces Id1-dependent radiation resistance and self-renewal in experimental glioblastoma.

Neuro Oncol 2016 10 28;18(10):1379-89. Epub 2016 Mar 28.

Cancer Biology and Genetics Program, Memorial Sloan Kettering Cancer Center, New York, New York (P.J.C., R.T., R.B.); Department of Molecular Biology, Weill Cornell Graduate School of Medical Sciences of Cornell University, New York, New York (R.T.); Departments of Biochemistry, Chemistry, and Pharmacology, A.B. Hancock Jr. Memorial Laboratory for Cancer Research, Vanderbilt Institute of Chemical Biology, Vanderbilt University School of Medicine, Nashville, Tennessee (P.J.K., L.J.M.); Department of Neurosurgery, Memorial Sloan Kettering Cancer Center, New York, New York (F.S., V.S.T); Department of Medicine, Weill Cornell Medical College, New York, (D.C.M, A.J.D.)

Background: In glioblastoma (GBM), Id1 serves as a functional marker for self-renewing cancer stem-like cells. We investigated the mechanism by which cyclooxygenase-2 (Cox-2)-derived prostaglandin E2 (PGE2) induces Id1 and increases GBM self-renewal and radiation resistance.

Methods: Mouse and human GBM cells were stimulated with dimethyl-PGE2 (dmPGE2), a stabilized form of PGE2, to test for Id1 induction. To elucidate the signal transduction pathway governing the increase in Id1, a combination of short interfering RNA knockdown and small molecule inhibitors and activators of PGE2 signaling were used. Western blotting, quantitative real-time (qRT)-PCR, and chromatin immunoprecipitation assays were employed. Sphere formation and radiation resistance were measured in cultured primary cells. Immunohistochemical analyses were carried out to evaluate the Cox-2-Id1 axis in experimental GBM.

Results: In GBM cells, dmPGE2 stimulates the EP4 receptor leading to activation of ERK1/2 MAPK. This leads, in turn, to upregulation of the early growth response1 (Egr1) transcription factor and enhanced Id1 expression. Activation of this pathway increases self-renewal capacity and resistance to radiation-induced DNA damage, which are dependent on Id1.

Conclusions: In GBM, Cox-2-derived PGE2 induces Id1 via EP4-dependent activation of MAPK signaling and the Egr1 transcription factor. PGE2-mediated induction of Id1 is required for optimal tumor cell self-renewal and radiation resistance. Collectively, these findings identify Id1 as a key mediator of PGE2-dependent modulation of radiation response and lend insight into the mechanisms underlying radiation resistance in GBM patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/neuonc/now049DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5035519PMC
October 2016

Severe Re-expansion Pulmonary Edema Induced by One-Lung Ventilation.

Respir Care 2015 Aug 17;60(8):e134-40. Epub 2015 Feb 17.

Department of Anesthesiology and Resuscitology, Shinshu University School of Medicine, Matsumoto, Nagano, Japan.

We present 2 cases of severe re-expansion pulmonary edema (RPE) after one-lung ventilation (OLV) for thoracic surgery. A 32-y-old woman with multiple lung metastases developed severe RPE after OLV during lung resection surgery. A 37-y-old man with infective endocarditis also developed severe RPE after OLV for mitral valve plasty with minimally invasive cardiac surgery. In both cases, results of a preoperative pulmonary function test and oxygenation were almost normal, and pleural effusion or pulmonary congestion was not detected in preoperative computed tomography; however, there was a possibility that subclinical lung injury existed before surgery. The levels of interleukin-8 and monocyte chemotactic protein-1, which are thought to play important roles in the development of lung injury, in bronchial secretions were extremely high after the onset of RPE. These results suggest that the pathogenesis of RPE shares, at least in part, a common pathophysiology of acute lung injury.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4187/respcare.03759DOI Listing
August 2015

Organotypic explant culture of glioblastoma multiforme and subsequent single-cell suspension.

Curr Protoc Stem Cell Biol 2011 Dec;Chapter 3:Unit3.5

Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, New York, USA.

Glioblastoma multiforme (GBM) is one of the most aggressive brain tumors. GBM cell lines used in laboratory studies are frequently passaged in various culture media at high proliferation rates, resulting in significant genetic and molecular alterations. Thus, data obtained in cell lines are often inapplicable to patient tumors. Furthermore, recent studies suggest that there is a stem cell-like hierarchy among GBM cell populations and a crucial role for tumor vasculature in stem cells, as well as tumor growth, which cannot be reproduced in cell line cultures. Our laboratory has developed a novel three-dimensional (3D) organotypic "explant" system of surgical GBM specimens that preserves tumor cells in their original milieu, as well as the cytoarchitecture of the tumor stroma. Our previous study on the role of Notch inhibition has demonstrated a definitive effect on the tumor endothelium that could only be highlighted by this system. In this unit, we describe a detailed protocol for preparing GBM explants, and discuss strengths, as well as limitations of the explant system as an in vitro 3D model of GBM.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/9780470151808.sc0305s19DOI Listing
December 2011

Preparation, properties, and crystal structures of organometallic ionic liquids comprising 1-ferrocenyl-3-alkylimidazolium-based salts of bis(trifluoromethanesulfonyl)amide and hexafluorophosphate.

Inorg Chem 2010 Nov;49(21):10032-40

Department of Chemistry, Graduate School of Science, Kobe University, Rokkodai, Nada, Hyogo 657-8501, Japan.

Bis(trifluoromethanesulfonyl)amide (TFSA), hexafluorophosphate (PF(6)(-)), and iodide salts of 1-ferrocenyl-3-alkylimidazolium were prepared and their thermal and physical properties, including the dependence on alkyl chain length (methyl-hexadecyl), were investigated. The TFSA salts were highly viscous ionic liquids with melting points around room temperature. 1-Ferrocenyl-4-methyltriazolium salts were also prepared for comparison. The ferrocenylimidazolium and ferrocenyltriazolium cations showed redox waves for both the ferrocenyl moiety and the azolium moiety and exhibited corresponding charge-transfer bands at around 330 nm, which were analyzed using the Marcus-Hush model. Crystal structure determinations at low temperature revealed that the PF(6) and iodide salts form layerlike structures composed of ionic layers of the charged moieties. The TFSA salt exhibited short hydrogen-bond-like intermolecular contacts between the hydrogen atoms of the cation and oxygen atoms of the anion.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1021/ic1013363DOI Listing
November 2010

Inhibition of notch signaling in glioblastoma targets cancer stem cells via an endothelial cell intermediate.

Stem Cells 2010 Jun;28(6):1019-29

Department of Neurosurgery, Memorial Sloan Kettering Cancer Center and Weill Cornell Medical College, New York, NY, USA.

Glioblastoma multiforme (GBM) is a highly heterogeneous malignant tumor. Recent data suggests the presence of a hierarchical organization within the GBM cell population that involves cancer cells with stem-like behavior, capable of repopulating the tumor and contributing to its resistance to therapy. Tumor stem cells are thought to reside within a vascular niche that provides structural and functional support. However, most GBM studies involve isolated tumor cells grown under various culture conditions. Here, we use a novel three-dimensional organotypic "explant" system of surgical GBM specimens that preserves cytoarchitecture and tumor stroma along with tumor cells. Notch inhibition in explants results in decreased proliferation and self-renewal of tumor cells but is also associated with a decrease in endothelial cells. When endothelial cells are selectively eliminated from the explants via a toxin conjugate, we also observed a decrease in self-renewal of tumor stem cells. These findings support a critical role for tumor endothelial cells in GBM stem cell maintenance, mediated at least in part by Notch signaling. The explant system further highlighted differences in the response to radiation between explants and isolated tumor neurospheres. Combination treatment with Notch blockade and radiation resulted in a substantial decrease in proliferation and in self-renewal in tumor explants while radiation alone was less effective. This data suggests that the Notch pathway plays a critical role in linking angiogenesis and cancer stem cell self-renewal and is thus a potential therapeutic target. Three-dimensional explant systems provide a novel approach for the study of tumor and microenvironment interactions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1002/stem.429DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5532884PMC
June 2010

Modelling pathogenesis and treatment of familial dysautonomia using patient-specific iPSCs.

Nature 2009 Sep 19;461(7262):402-6. Epub 2009 Aug 19.

Developmental Biology Program, Sloan-Kettering Institute, 1275 York Ave, USA.

The isolation of human induced pluripotent stem cells (iPSCs) offers a new strategy for modelling human disease. Recent studies have reported the derivation and differentiation of disease-specific human iPSCs. However, a key challenge in the field is the demonstration of disease-related phenotypes and the ability to model pathogenesis and treatment of disease in iPSCs. Familial dysautonomia (FD) is a rare but fatal peripheral neuropathy, caused by a point mutation in the IKBKAP gene involved in transcriptional elongation. The disease is characterized by the depletion of autonomic and sensory neurons. The specificity to the peripheral nervous system and the mechanism of neuron loss in FD are poorly understood owing to the lack of an appropriate model system. Here we report the derivation of patient-specific FD-iPSCs and the directed differentiation into cells of all three germ layers including peripheral neurons. Gene expression analysis in purified FD-iPSC-derived lineages demonstrates tissue-specific mis-splicing of IKBKAP in vitro. Patient-specific neural crest precursors express particularly low levels of normal IKBKAP transcript, suggesting a mechanism for disease specificity. FD pathogenesis is further characterized by transcriptome analysis and cell-based assays revealing marked defects in neurogenic differentiation and migration behaviour. Furthermore, we use FD-iPSCs for validating the potency of candidate drugs in reversing aberrant splicing and ameliorating neuronal differentiation and migration. Our study illustrates the promise of iPSC technology for gaining new insights into human disease pathogenesis and treatment.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature08320DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2784695PMC
September 2009

Circadian phosphorylation of ATF-2, a potential activator of Period2 gene transcription in the chick pineal gland.

J Neurochem 2007 Dec 13;103(5):1834-42. Epub 2007 Sep 13.

Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Bunkyo-Ku, Tokyo, Japan.

Stimulus-induced transcription of the Period gene is a critical step for phase-shift of vertebrate circadian systems. The promoter region of chicken Period2 contains a canonical calcium/cAMP-responsive element, but its functional relevance is not known. The present study shows that cAMP-responsive element-binding protein (CREB) and activating transcription factor-2 (ATF-2) bind to the promoter region of the Period2 gene in the chick pineal gland. In transient transfection assays, a reporter construct containing 0.7-kbp upstream region of chicken Period2 was transactivated by ATF-2, but it was poorly responsive to CREB. In the chick pineal gland, phosphorylation of CREB protein at the kinase-inducible domain was negatively regulated by light. On the other hand, phosphorylation of ATF-2 at the amino-terminal transactivation domain exhibited a circadian rhythm with a daytime peak, suggesting a role for ATF-2 in circadian rhythmicity in the chick pineal gland.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/j.1471-4159.2007.04900.xDOI Listing
December 2007

The histone H3K4 demethylase SMCX links REST target genes to X-linked mental retardation.

Nature 2007 May 29;447(7144):601-5. Epub 2007 Apr 29.

Division of Endocrinology, Diabetes, and Hypertension, Department of Medicine and BCMP, Brigham and Women's Hospital and Harvard Medical School, 221 Longwood Avenue Boston, Massachusetts 02115, USA.

Gene transcription is critically influenced by chromatin structure and the modification status of histone tails. Methylation of lysine residues in histone tails is dynamically regulated by the opposing activities of histone methyltransferases and histone demethylases. Here we show that JARID1C/SMCX, a JmjC-domain-containing protein implicated in X-linked mental retardation and epilepsy, possesses H3K4 tri-demethylase activity and functions as a transcriptional repressor. An SMCX complex isolated from HeLa cells contains additional chromatin modifiers (the histone deacetylases HDAC1 and HDAC2, and the histone H3K9 methyltransferase G9a) and the transcriptional repressor REST, suggesting a direct role for SMCX in chromatin dynamics and REST-mediated repression. Chromatin immunoprecipitation reveals that SMCX and REST co-occupy the neuron-restrictive silencing elements in the promoters of a subset of REST target genes. RNA-interference-mediated depletion of SMCX derepresses several of these targets and simultaneously increases H3K4 trimethylation at the sodium channel type 2A (SCN2A) and synapsin I (SYN1) promoters. We propose that loss of SMCX activity impairs REST-mediated neuronal gene regulation, thereby contributing to SMCX-associated X-linked mental retardation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/nature05823DOI Listing
May 2007

p38 mitogen-activated protein kinase regulates oscillation of chick pineal circadian clock.

J Biol Chem 2003 Jul 28;278(27):25166-71. Epub 2003 Apr 28.

Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Japan.

Extracellular signal-regulated kinase (ERK) and p38 are members of the mitogen-activated protein kinase (MAPK) family, and in some cases these kinases serve for closely related cellular functions within a cell. In a wide range of animal clock structures, ERK plays an important role in the circadian time-keeping mechanism. Here we found that immunoreactivity to p38 protein was uniformly distributed among cells in the chick pineal gland. On the other hand, a constant level of activated p38 was detected over the day, predominantly in the follicular and parafollicular pinealocytes that are potential circadian clock-containing cells. Chronic application of SB203580, a selective and reversible inhibitor of p38, to the cultured chick pineal cells markedly lengthened the period of the circadian rhythm of the melatonin release (up to 28.7 h). Noticeably, despite no significant temporal change of activated p38 level, a 4-h pulse treatment with SB203580 delayed the phase of the rhythm only when delivered during the subjective day. These results indicate a time-of-day-specific role of continuously activated p38 in the period length regulation of the chick pineal clock and suggest temporally separated regulation of the clock by two MAPKs, nighttime-activated ERK and daytime-working p38.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1074/jbc.M212726200DOI Listing
July 2003

Purification and immunohistochemical analysis of calcium-binding proteins expressed in the chick pineal gland.

J Pineal Res 2003 Apr;34(3):208-16

Department of Biophysics and Biochemistry, Graduate School of Science, The University of Tokyo, Tokyo 113-0033, Japan.

The pineal gland is a site of melatonin production, of which intracellular calcium ions (Ca2+) are likely involved in various aspects. To investigate the identity of molecules responsible for the Ca2+-dependent processes in the pineal cells, we prepared a cellular extract from 2000 chick pineal glands and isolated a series of Ca2+-binding proteins by taking advantage of their Ca2+-dependent hydrophobic interaction with phenyl-Sepharose beads. The proteins identified by micro-sequencing analysis included calmodulin, neurocalcin, sorcin, annexin II and annexin V. Immunohistochemical analysis of the chick pineal sections revealed that both calmodulin and sorcin are expressed in the follicular and parafollicular pinealocytes. On the other hand, neurocalcin was expressed in a few neuron-like cells located predominantly in the parafollicular layer of the pineal follicle. These results suggest that calmodulin and sorcin may contribute to cellular functions in the chick pinealocytes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1034/j.1600-079x.2003.00031.xDOI Listing
April 2003