GATA2 functions in adrenal chromaffin cells

Catecholamine synthesized in the sympathoadrenal system, including sympathetic neurons and adrenal chromaffin cells, is vital for cardiovascular homeostasis. It has been reported that GATA2, a zinc finger transcription factor, is expressed in murine sympathoadrenal progenitor cells. However, a physiological role for GATA2 in adrenal chromaffin cells has not been established. In this study, we demonstrate that GATA2 is specifically expressed in adrenal chromaffin cells. We examined the consequences of Gata2 loss- of- function mutations, exploiting a Gata2 conditional knockout allele crossed to neural crest- specific Wnt1- Cre transgenic mice (Gata2 NC- CKO). The vast majority of Gata2 NC- CKO embryos died by embryonic day 14.5 (e14.5) and exhibited a decrease in catecholamine- producing adrenal chromaffin cells, implying that a potential catecholamine defect might lead to the observed embryonic lethality. When intercrossed pregnant dams were fed with synthetic adrenaline analogs, the lethality of the Gata2 NC- CKO embryos was partially rescued, indicating that placental transfer of the adrenaline analogs complements the lethal catecholamine deficiency in the Gata2 NC- CKO embryos. These results demonstrate that GATA2 participates in the development of neuroendocrine adrenaline biosynthesis, which is essential for fetal survival.GATA2 is specifically expressed in adrenal chromaffin cells in which GATA2 plays a role for catecholamine biosynthesis.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162786/2/gtc12795_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162786/1/gtc12795.pd

Insulin-producing cells derived from ‘induced pluripotent stem cells’ of patients with fulminant type 1 diabetes: vulnerability to cytokine insults and increased expression of apoptosis-related genes

Aims/Introduction: The present study was carried out to generate induced pluripotent stem cells (iPSCs) from patients with fulminant type 1 diabetes, and evaluate the cytokine‐induced apoptotic reactions of β‐like insulin‐producing cells differentiated from the iPSCs.Materials and Methods: iPSCs were generated from fibroblasts of patients with fulminant type 1 diabetes by inducing six reprogramming factors. Insulin‐producing cells were differentiated from the iPSCs in vitro. The proportion of cleaved caspase‐3‐positive or terminal deoxynucleotidyl transferase 2′‐deoxyuridine, 5′‐triphosphate nick end labeling‐positive cells among insulin (INS)‐positive cells derived from fulminant type 1 diabetes iPSC and control human iPSC lines was evaluated under treatment with tumor necrosis factor‐α, interleukin‐1β and interferon‐γ. Ribonucleic acid sequencing was carried out to compare gene expressions in INS‐positive cells derived from fulminant type 1 diabetes iPSC and control human iPSC lines.Results: Two iPSC clones were established from each of three patients with fulminant type 1 diabetes. The differentiation of insulin‐producing cells from fulminant type 1 diabetes iPSC was confirmed by immunofluorescence analysis and KCl‐induced C‐peptide secretion. After treatment with pro‐inflammatory cytokines, these INS‐positive cells showed higher expression of cleaved caspase‐3 than those derived from control human iPSCs. Altered expression levels of several apoptosis‐related genes were observed in INS‐positive cells derived from the fulminant type 1 diabetes iPSCs by ribonucleic acid sequencing.Conclusions: We generated iPSCs from patients with fulminant type 1 diabetes and differentiated them into insulin‐producing cells. This in vitro disease model can be used to elucidate the disease mechanisms of fulminant type 1 diabetes

Lunatic fringe promotes the lateral inhibition of neurogenesis

Previous studies have identified roles of the modulation of Notch activation by Fringe homologues in boundary formation and in regulating the differentiation of vertebrate thymocytes and Drosophila glial cells. We have investigated the role of Lunatic fringe (Lfng) expression during neurogenesis in the vertebrate neural tube. We find that in the zebrafish hindbrain, Lfng is expressed by progenitors in neurogenic regions and downregulated in cells that have initiated neuronal differentiation. Lfng is required cell autonomously in neural epithelial cells to limit the amount of neurogenesis and to maintain progenitors. By contrast, Lfng is not required for the role of Notch in interneuronal fate choice, which we show is mediated by Notch1a. The expression of Lfng does not require Notch activity, but rather is regulated downstream of proneural genes that are widely expressed by neural progenitors. These findings suggest that Lfng acts in a feedback loop downstream of proneural genes, which, by promoting Notch activation, maintains the sensitivity of progenitors to lateral inhibition and thus limits further proneural upregulation

Heatstroke risk informing system using wearable perspiration ratemeter on users undergoing physical exercise

Abstract We constructed an informing system to users for the heatstroke risk using a wearable perspiration ratemeter and the users’ thirst responses. The sweating ratemeter was constructed with a capacitive humidity sensor in the ventilated capsule. The timing point for informing heatstroke risk was decided to change from positive to negative on the second derivative of sweating curve. In addition, a wearable self-identification and -information system of thirst response was constructed with a smartphone. To evaluate the validity of wearable apparatus, we aimed to conduct human experiments of 16 healthy subjects with the step up and down physical exercises. The blood and urine samples of the subjects were collected before and after the 30-min physical exercise. The concentrations of TP, Alb, and RBC increased slightly with the exercise. In contrast, the concentrations of vasopressin in all subjects remarkably increased with the exercise. In almost subjects, they identified their thirst response until several min after the informing for heatstroke risk. In conclusion, the wearable ratemeter and self-information system of thirst response were suitable for informing system of heatstroke risk. The validity of timing point for informing heatstroke risk was confirmed with changes in the thirst response and concentrations of vasopressin in blood

Abscopal Activation of Microglia in Embryonic Fish Brain Following Targeted Irradiation with Heavy-Ion Microbeam

Microglia remove apoptotic cells by phagocytosis when the central nervous system is injured in vertebrates. Ionizing irradiation (IR) induces apoptosis and microglial activation in embryonic midbrain of medaka (Oryzias latipes), where apolipoprotein E (ApoE) is upregulated in the later phase of activation of microglia In this study, we found that another microglial marker, l-plastin (lymphocyte cytosolic protein 1), was upregulated at the initial phase of the IR-induced phagocytosis when activated microglia changed their morphology and increased motility to migrate. We further conducted targeted irradiation to the embryonic midbrain using a collimated microbeam of carbon ions (250 μm diameter) and found that the l-plastin upregulation was induced only in the microglia located in the irradiated area. Then, the activated microglia might migrate outside of the irradiated area and spread through over the embryonic brain, expressing ApoE and with activated morphology, for longer than 3 days after the irradiation. These findings suggest that l-plastin and ApoE can be the biomarkers of the activated microglia in the initial and later phase, respectively, in the medaka embryonic brain and that the abscopal and persisted activation of microglia by IR irradiation could be a cause of the abscopal and/or adverse effects following irradiation

Live imaging of AO-stained apoptosis and the assessment of cell proliferation after low dose irradiation during a period of extreme growth of tectum mesencephali in the Medaka

The 2nd Asian Congress of Radiation Researc

An Approach to Elucidate NBS1 Function in DNA Repair Using Frequent Nonsynonymous Polymorphism in Wild Medaka (Oryzias latipes) Populations.

Nbs1 is one of the genes responsible for Nijmegen breakage syndrome, which is marked with high radiosensitivity. In human NBS1 (hNBS1), Q185E polymorphism is known as the factor to cancer risks, although its DSB repair defect has not been addressed. Here we investigated the genetic variations in medaka (Oryzias latipes) wild populations, and found 40 nonsynonymous single nucleotide polymorphisms (SNPs) in medaka nbs1 (olnbs1) gene within 5 inbred strains. A mutation to histidine in Q170 residue in olNbs1, which corresponds to Q185 residue of hNBS1, was widely distributed in the closed colonies derived from the eastern Korean population of medaka. Overexpression of H170 type olNbs1 in medaka cultured cell lines resulted in the increased accumulation of olNbs1 at laser-induced DSB sites. Autophosphorylation of DNA-dependent protein kinase at T2609 was suppressed after the γ-ray irradiation, which was followed by prolonged formation of γ-H2AX foci and delayed DSB repair. These findings suggested that the nonsynonymous SNP (Q170H) in olnbs1, which induced DSB repair defects, is specifically distributed in the eastern Korean population of medaka. Furthermore, examination using the variation within wild populations might provide a novel method to characterize a driving force to spread the disease risk alleles