<ORIGINAL ARTICLE>Histochemical Localization of Carbonic Anhydrase in the Taste Buds of the Mouse and Goldfish

The activity of carbonic anhydrase in the taste buds of the mouse and goldfish was examined by enzyme histochemistry. An intense reaction of carbonic anhydrase was observed in the middle and basal regions of the taste buds in the mouse circumvallate papillae. Under the electron microscope, the reaction product was found in the cytoplasm of type-I cells which are characterized by the presence of ribosomes and rough endoplasmic reticulum. In other cell types (type-II and type-Ill cells), no reaction was detected. In the fungiform papillae, the reactivity was similar to that in the circumvallate ones; however, only a few cells were positively stained. In the goldfish, the receptor cells, which are characterized by the presence of tubular system, showed strong carbonic anhydrase activity. The results suggest that the activity of carbonic anhydrase, which is usually associated with H^+ or HCOs transport, is present in a specific type of taste bud cells

<ORIGINAL ARTICLE>Stem cells of olfactory cells during embryonic development

胎生期のマウスの嗅上皮と鋤鼻器の嗅細胞の幹細胞についてブロモデオキシウリジン(BrdU)と神経細胞接着分子(NCAM)の抗体を用いた二重染色と電顕により調べた。妊娠マウスにBrdUを投与し1時間後屠殺すると,胎生12日目の嗅上皮と鋤鼻器では上皮全体にBrdU標識細胞が多数みられ,活発に分裂していることが示唆された。これらの細胞は円柱形で,少数のリボゾーム,粗面小胞体を有しNCAM陰性であった。これらの細胞の間にNCAM陽性の嗅細胞が少数みられた。胎生14日目には,円柱形細胞は上皮の基底側に限局するようになった。円柱形細胞のBrdU標識は,BrdU投与24時間後には大部分,上皮中央の嗅細胞層へ移動することから,この円柱形細胞が嗅細胞へ分化することが示唆された。胎生17～19日目には,円柱形細胞は,鋤鼻器ではNCAM陽性の丸い細胞に,嗅上皮では二種類の基底細胞(globose basal cells, basal cells proper)に置き代るようになる。Stem cells of olfactory (receptor) cells in the olfactory epithelium and vomeronasal organ during embryonic development of mice were investigated by double immunostaining using anti-neural cell adhesion molecule (NCAM) and anti-bromodeoxyuridine (BrdU) antibodies and by electron microscopy. The columnar-shaped cells which were negative for NCAM and located throughout the epithelium on embryonic day (E) 12 and then in the basal region after E 14, were numerously labeled with BrdU, indicating active division, when BrdU was injected 1 hr before sacrifice. These cells are presumed to develop into NCAM-immunoreactive olfactory (receptor) cells of the middle region of the epithelium since numerous labelings appeared in the middle region 24 hrs after injection of BrdU. Evidence of migration of the columnar cells from olfactory epithelium along the axons was observed. On E 17, the columnar cells in the vomeronasal organ became round-shaped, located above the processes of the supporting cells, and were stained with NCAM. On the other hand, the columnar cells in the olfactory epithelium differentiated into round-shaped cells and pyramidal-shaped cells on E 19, which respectively corresponded to globose basal cells and basal cells proper seen in postnatal epithelium, although the round-shaped cells were negative for NCAM. The result suggests that the columnar cells as stem cells of olfactory (recepetor) cells observed in embryonic days differentiate into round-shaped cells in late embryonic days and that cells in the olfactory epithelium mature at a later stage than those in the VNO

Micro(mi) RNA-34a targets protein phosphatase (PP)1γ to regulate DNA damage tolerance.

The DNA damage response (DDR) triggers widespread changes in gene expression, mediated partly by alterations in micro(mi) RNA levels, whose nature and significance remain uncertain. Here, we report that miR-34a, which is upregulated during the DDR, modulates the expression of protein phosphatase 1γ (PP1γ) to regulate cellular tolerance to DNA damage. Multiple bio-informatic algorithms predict that miR-34a targets the PP1CCC gene encoding PP1γ protein. Ionising radiation (IR) decreases cellular expression of PP1γ in a dose-dependent manner. An miR-34a-mimic reduces cellular PP1γ protein. Conversely, an miR-34a inhibitor antagonizes IR-induced decreases in PP1γ protein expression. A wild-type (but not mutant) miR-34a seed match sequence from the 3' untranslated region (UTR) of PP1CCC when transplanted to a luciferase reporter gene makes it responsive to an miR-34a-mimic. Thus, miR-34a upregulation during the DDR targets the 3' UTR of PP1CCC to decrease PP1γ protein expression. PP1γ is known to antagonize DDR signaling via the ataxia-telangiectasia-mutated (ATM) kinase. Interestingly, we find that cells exposed to DNA damage become more sensitive - in an miR-34a-dependent manner - to a second challenge with damage. Increased sensitivity to the second challenge is marked by enhanced phosphorylation of ATM and p53, increased γH2AX formation, and increased cell death. Increased sensitivity can be partly recapitulated by a miR-34a-mimic, or antagonized by an miR-34a-inhibitor. Thus, our findings suggest a model in which damage-induced miR-34a induction reduces PP1γ expression and enhances ATM signaling to decrease tolerance to repeated genotoxic challenges. This mechanism has implications for tumor suppression and the response of cancers to therapeutic radiation.Work in ARV's laboratory is funded by the Medical Research Council.This is the author accepted manuscript. The final version is available from Taylor & Francis via http://dx.doi.org/10.1080/15384101.2015.106420

Making Skeletal Muscle from Human Pluripotent Stem Cells

Human pluripotent stem cells (hPSCs) proliferate in vitro for long periods without losing pluripotency and can be induced to differentiate into various cell types including skeletal muscle cells (SMCs). Human embryonic stem cells (hESCs) are generated from a preimplantation-stage embryo. Human-induced pluripotent stem cells (hiPSCs) are derived from somatic cells of both healthy donors and patients with muscle diseases of any age using reprogramming factors. Currently, there are two kinds of protocols to induce skeletal muscle from hPSCs. One type utilizes overexpression of a potent myogenic master regulator, MyoD, to directly induce skeletal muscle. Stepwise induction of skeletal muscle has also been reported by many research groups, but hiPSC-based cell therapy for muscular dystrophy is still experimental. On the other hand, hiPSCs derived from patients with muscle disease are widely used for disease modeling in vitro. Here, we review the recent literature on derivation of skeletal muscle from human pluripotent stem cells and discuss their application

Process of parenting a child with RB

Background : Retinoblastoma（RB） occurs at a very young age. Since the disease is diagnosed at an early age, the family is responsible for the care of the childʼs disease acceptance. Objective : This study aims to explore the parenting process of children with RB toward disease acceptance. Methods : Parents of eleven children with RB living in Japan were interviewed, and the data were analyzed using the Modified Grounded Theory Approach of Kinoshita（M-GTA）. Results : There were twenty-one concepts representing the process of parenting a child with RB while guiding him or her toward disease acceptance, and nineteen of them were classified into ten categories based on semantic similarities. The two other concepts showed similar interpretability to categories. These categories and concepts were summarized into two core categories : “Helping the child develop a positive mindset to define the disease as a part of him/herself ” and “Paving the way in advance for the child to live comfortably when his or her living space expands”. Conclusions : In a cyclical framework of parenting, consisting of two core categories described in Results, the parents coordinated these two approaches while maintaining balance by “Avoiding saying anything that does not need to be said” and established their process of parenting a child with RB while guiding him or her toward disease acceptance, according to their household situation. The results suggest the necessity of recognizing that in childhood-onset cancers, such as RB, and diseases involving genetic issues, problems tend to occur not only during the treatment period but also at the time of life events and providing support from a comprehensive perspective

Dose-Dependent Effects of Barley Cooked with White Rice on Postprandial Glucose and Desacyl Ghrelin Levels

White rice is an indispensable staple food in Japan, although it is a high glycemic index food. The objective of this study was to estimate how barley cooked with white rice might affect postprandial glucose, insulin and desacyl ghrelin concentrations as well as fullness. The study was conducted in randomized crossover design with nine healthy subjects. Blood glucose, insulin, free fatty acid and desacyl ghrelin concentrations and subjective levels of fullness and hunger were measured for 240 min after intake of glucose, white rice, 30% rolled barley (30BAR), 50% rolled barley (50BAR) and 100% rolled barley (100BAR) containing 75 g of available carbohydrate. Postprandial glucose and insulin levels were suppressed by intake of 30BAR, 50BAR and 100BAR comparing with those of white rice. Area under the curves of plasma glucose and insulin concentrations was reduced by barley intake in a dose-dependent manner. Although plasma desacyl ghrelin levels decreased postprandially, the degree of reduction was suppressed by barley intake in a dose-dependent manner. Postprandial desacyl ghrelin levels can be a sensitive biomarker of carbohydrate metabolism. The combination of white rice with barley plays a beneficial role in preventing and treating type 2 diabetes, obesity and other metabolic diseases