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Biomedical subjects

Noriyuki Satoh

Publications and source records attributed to Noriyuki Satoh.

11 recordsLinked to original sources
PubMed2026

Developmental Fates of Progenitor/Undifferentiated Cells With Histone Trimethylation Tags in the Stony Coral, Acropora tenuis.

The stony coral, Acropora tenuis, possesses progenitor/undifferentiated cells similar to other anthozoans; however, their developmental potential and fate remain obscure. The present study initially showed that nerve progenitors and undifferentiated-like cells were both tagged with histone H3 trimethylation at Lys 4 and Lys 27, suggesting that Acropora progenitor/undifferentiated cells might be multipotent. A rabbit anti-reverse transcriptase (anti-AtRTase) antibody recognized undifferentiated-like cells in the middle region of the ectodermal layer in embryos 60-85 h post-fertilization. At the larval stages, AtRTase signals were concentrated around the oral pole where the larval ectoderm invaginated to form the pharyngeal stomodeum. Undifferentiated-like cells, but not the apical-most glandular epithelium in the ectoderm, appeared to enter the pharynx. Consistent with this hypothesis, AtRTase signals were continuous from undifferentiated-like cells to the stomodeum. Nerve progenitors (neuroblasts) expressed nerve-specific tubulin beta-III (TUBB3). They differentiated into nerve cells and expressed a neuroblast differentiation-associated protein around the aboral pole of larvae. On the other hand, non-aboral neuroblasts expressed the autophagy-related protein 10 in addition to TUBB3 and developed into vacuolated hyaline cells (VHCs) that penetrated through the ectoderm apicobasally. The present study suggests strongly that ectodermal undifferentiated cells in A. tenuis have the potential to form the stomodeum. In contrast, nerve progenitors possess the dual potential to differentiate into nerve cells and VHCs, which appears to depend on aboral and non-aboral positions.

Animals↗
PubMed2025

The genomic origin of the unique chaetognath body plan.

The emergence of animal phyla, each with their unique body plan, was a rapid event in the history of animal life, yet its genomic underpinnings are still poorly understood1. Here we investigate at the genomic, regulatory and cellular levels, the origin of one of the most distinctive animal phyla, the chaetognaths, whose organismal characteristics have historically complicated their phylogenetic placement2,3. We show that these characteristics are reflected at the cell-type level by the expression of genes that originated in the chaetognath lineage, contributing to adaptation to planktonic life at the sensory and structural levels4. Similarly to other members of gnathiferans (which also include rotifers and several other microscopic phyla)5,6, chaetognaths have undergone accelerated genomic evolution with gene loss and chromosomal fusions7,8. Furthermore, they secondarily duplicated thousands of genes9,10, without evidence for a whole-genome duplication, yielding, for instance, tandemly expanded Hox genes, as well as many phylum-specific genes. We also detected repeat-rich highly methylated neocentromeres and a simplified DNA methylation toolkit that is involved in mobile element repression rather than transcriptional control. Consistent with fossil evidence11,12, our observations suggest that chaetognaths emerged after a phase of morphological simplification through a reinvention of organ systems paralleled by massive genomic reorganization, explaining the uniqueness of their body plan.

Animals↗
PubMed2006

Synthesis and in vitro cytotoxicity of 1,2,3,4-tetrahydroisoquinoline derivatives.

Several 1-alkyl-1,2,3,4-tetrahydroisoquinoline (TIQ) derivatives, which may play a role in Parkinson's disease, have been synthesized via Pummerer-type cyclization of the sulfonium ion formed in situ from N-formyl sulfoxide. Using an in vitro trypan blue exclusion assay, high concentrations of TIQ derivatives possessing bulky alkyl group substituents such as 1-cyclobutyl-, 1-cyclohexyl-, 1-phenyl- or 1-benzyl- at the C-1 position were found to significantly affect the viability of PC12 cells. Moreover, TIQ derivatives that moderately or strongly induced apoptosis (e.g., 1-phenyl-TIQ and 1-cyclohexyl-TIQ, respectively) paralleled the results obtained using the trypan blue exclusion assay. These results suggest that the size and electron-donating properties of functional groups may affect the cytotoxicity of TIQ derivatives.

Animals↗
PubMed2005

A saturation screen for cis-acting regulatory DNA in the Hox genes of Ciona intestinalis.

A screen for the systematic identification of cis-regulatory elements within large (>100 kb) genomic domains containing Hox genes was performed by using the basal chordate Ciona intestinalis. Randomly generated DNA fragments from bacterial artificial chromosomes containing two clusters of Hox genes were inserted into a vector upstream of a minimal promoter and lacZ reporter gene. A total of 222 resultant fusion genes were separately electroporated into fertilized eggs, and their regulatory activities were monitored in larvae. In sum, 21 separable cis-regulatory elements were found. These include eight Hox linked domains that drive expression in nested anterior-posterior domains of ectodermally derived tissues. In addition to vertebrate-like CNS regulation, the discovery of cis-regulatory domains that drive epidermal transcription suggests that C. intestinalis has arthropod-like Hox patterning in the epidermis.

Animals↗
PubMed2004

Effects of incremental curing on contraction stresses associated with various resin composite buildups.

OBJECTIVE: The purpose of this study was to photoelastically evaluate contraction stresses associated with various resin composite build-up procedures, including incremental curing and the use of flowable composite for pulpless molars. METHOD AND MATERIALS: Life-sized photoelastic models of an endodontically treated molar were fabricated. The cavity represented a conservative access preparation and included four lateral walls. The following materials were used for buildup: dual-cured hybrid composite (Cleafil DC Core [DC], BIS-CORE [BC]); light-cured flowable composite (AELITEFLO LV [ALV]); and chemical-cured flowable composite (CORE-FLO [CF]). The photoelastic models were built up with the following techniques: bulk-cured (BDd [dual-cured DC], BDc [chemically-cured DC], BBd [dual-cured BC], and BC [CF]); and incremental-cured (1 mm gingivally + 3.5 mm occlusally; IAB [ALV + BC], ICB [CF + BC], and IBB [BC + BC]). Isochromatic fringes developed in the models were recorded photographically in the field of a circular polariscope, and maximum fringe order was determined. Five specimens were tested for each condition. RESULTS: Stress intensity of the build-up methods fell into two categories: high (BDd, BBd, BC, and IAB) and low (BDc, ICB, and IBB). The difference between high and low groups was statistically significant, except between BC and ICB. The maximum fringe order was developed around the point angles at the cavity floor for all the conditions tested. CONCLUSIONS: Type and setting mechanism of resin composite build-up technique had considerable influence on contraction stress. Incremental buildup using composites with low elastic modulus did not reduce contraction stress intensity compared with bulk-cured techniques.

Barium Compounds↗
PubMed2003

Regulation of ascidian Rel by its alternative splice variant.

The Rel/NF-kappaB family of transcription factors play key roles in morphogenesis and immune responses. We reported previously that As-rel1 and As-rel2 of the ascidian Halocynthia roretzi are involved in notochord formation. The As-rel1 protein is a typical Rel/NF-kappaB family member, whereas the As-rel2 protein is a novel truncated product of As-rel1 that lacks a nuclear localization signal and the unique C-terminal region. Here, we present conclusive evidence that As-rel1 and As-rel2 are generated from a single gene by alternative splicing. We analyzed the roles of As-rel2 using cells transfected with As-rel1 or As-rel2 or both. As-rel1 was localized in the nucleus and As-rel2 in the cytoplasm when they were transfected individually. In contrast, when they were transfected simultaneously, both were localized in the nucleus because of the association of As-rel2 with As-rel1. In this case, the transcriptional activity of As-rel1 was suppressed by As-rel2. Ascidian IkappaB was found to sequester As-rel1 in the cytoplasm and suppress its transcriptional activity when As-rel1 and IkappaB were transfected simultaneously. In contrast, when As-rel1 and IkappaB were transfected together with As-rel2, As-rel1 was transported into the nucleus and its transcriptional activity was rescued from inhibition by IkappaB, whereas As-rel2 remained localized in the cytoplasm, suggesting IkappaB sequestration in the cytoplasm by As-rel2. From these findings, we conclude that the alternative splice variant, As-rel2, regulates the nuclear localization and transcriptional activity of As-rel1.

Alternative Splicing↗
PubMed2003

Contraction stress of composite resin build-up procedures for pulpless molars.

PURPOSE: The purpose of this study was to photoelastically evaluate contraction stresses associated with various resin composite build-up procedures for pulpless molars. MATERIALS AND METHODS: Photoelastic models of endodontically treated mandibular molars were fabricated to simulate a preparation for a full-cast crown. The model configuration included three lateral walls, but no post space. The buildups were made with dual-curing resin composite using the following procedures: 1) bulk dual cure, 2) bulk chemical cure, 3) horizontal two increments, dual cure, and 4) indirect. Five specimens were fabricated for each condition. The stresses developed in the models were recorded photographically in the field of a circular polariscope. RESULTS: The build-up procedures tested generated widely different stress distributions and intensities. The highest stresses were seen with the bulk dual-cure method. The slower polymerization chemical-cure group developed distributions similar to the bulk dual-cure group with a significantly lower fringe order. The two horizontal increments dual-cure techniques developed an individual group of fringes for each layer. Compared with the bulk dual-cure group, stresses around the occlusal margin were reduced by incrementalization, while fringes were more closely spaced at the line angles with a slightly lower fringe order. The indirect method demonstrated the lowest stress which extended over the smallest area. CONCLUSION: Contraction stress in resin composite buildups varied significantly depending upon the procedures of fabrication. The bulk dual-cure method developed the most severe contraction stresses, while the indirect technique resulted in significantly lower contraction stresses than the other techniques tested.

Analysis of Variance↗
PubMed2002

The renin-angiotensin and adrenergic nervous system in cardiac hypertrophy in fructose-fed rats.

BACKGROUND: Hyperinsulinemia and insulin resistance are associated with left ventricular hypertrophy (LVH) and cardiovascular complications in hypertensive subjects. The aim of this study was to explore the mechanisms for LVH including activation of the renin-angiotensin system system (RAS) and the sympathetic nervous system and their activation by insulin using a rat model of hyperinsulinemia and insulin resistance. METHODS: Male Sprague-Dawley rats were fed a high-fructose or control diet. The fructose-fed rats (FFR) were divided into four subgroups that were administrated either vehicle or the following antihypertensive drugs (n = 6-8) for 4 weeks: 1) olmesartan, an angiotensin II type 1 (AT1) receptor antagonist; 2) bunazosin, an alpha1-receptor blocker; and 3) hydralazine, a direct vasodilator. RESULTS: Fructose feeding induced significant increases in mean systolic blood pressure (BP) levels at 4 weeks (control, 117 v fructose, 131 mm Hg), left ventricular weight, and the sum of the insulin level in response to a glucose tolerance test (2 g/kg). Fructose feeding also increased urinary excretion of epinephrine and norepinephrine, the density of cardiac alpha1-adrenergic receptors, and the content of angiotensin II in the left ventricle. All antihypertensive drugs decreased systolic BP, but only the AT1 receptor antagonist attenuated the development of LVH in FFR. The AT1 receptor antagonist did not affect glucose-mediated insulin responses, but did suppress urinary catecholamine excretion and cardiac alpha1-adrenergic receptor density. CONCLUSIONS: Left ventricular hypertrophy in FFR may be less dependent on systemic elevations of BP and more dependent on the RAS and the sympathetic nervous system. Use of an AT1 receptor antagonist might be the most beneficial way to prevent progression of LVH through direct effects on tissue RAS and the sympathetic nervous system in FFR. As these changes occur in a rat model with hyperinsulinemia, insulin may have a role in promoting LVH by activating the local RAS and sympathetic nervous system activity.

Adrenergic alpha-Antagonists↗