Biomedical subjects

Yoshiyuki Ishii

Publications and source records attributed to Yoshiyuki Ishii.

At least 19 recordsLinked to original sources

PubMed2007

The combination of ubiquitous transcription factors AP-1 and Sp1 directs keratinocyte-specific and differentiation-specific gene expression in vitro.

Previous studies of epidermal-specific gene promoters suggested that a limited set of transcription factors regulate keratinocyte-specific and differentiation-specific gene expression in the epidermis. In the present study, we investigated the functional importance of AP-1- and Sp1-binding elements in the determination of cell type-specific and differentiation-specific gene expression by transient transfection into undifferentiated and differentiated keratinocytes as well as into various non-epidermal cell lines. Synthesized short AP-1- and/or Sp1-binding elements were inserted into a minimal reporter vector, and the artificial promoter containing both AP-1 and Sp1 elements showed high levels of transcriptional activity only when transfected into differentiated keratinocytes. Promoters containing either the AP-1 or the Sp1 motif alone showed little activity in any of the cells examined. We also found that close proximity of the Sp1 and AP-1 sites is essential for transcriptional activity, suggesting that the physical interaction between Sp1 and AP-1 factors is important for functional activity. These results clearly demonstrate that the combination of ubiquitously expressed transcription factors AP-1 and Sp1 confers keratinocyte specificity and differentiation specificity on the gene expression. Our findings also provide a simple model of the mechanisms underlying regulation of cell type-specific and cell differentiation-specific gene expression by ubiquitously expressed transcription factors.

Animals↗

PubMed2006

The gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, is mutated in inherited anonychia.

Anonychia and hyponychia congenita (OMIM 206800) are rare autosomal recessive conditions in which the only presenting phenotype is the absence or severe hypoplasia of all fingernails and toenails. After determining linkage to chromosome 20p13, we identified homozygous or compound heterozygous mutations in the gene encoding R-spondin 4 (RSPO4), a secreted protein implicated in Wnt signaling, in eight affected families. Rspo4 expression was specifically localized to developing mouse nail mesenchyme at embryonic day 15.5, suggesting a crucial role in nail morphogenesis.

Amino Acid Sequence↗

PubMed2006

Neutralization of HPV16, 18, 31, and 58 pseudovirions with antisera induced by immunizing rabbits with synthetic peptides representing segments of the HPV16 minor capsid protein L2 surface region.

Neutralizing antibody against human papillomavirus (HPV) minor capsid protein L2 can cross-neutralize different HPV genotypes in vitro. To identify the segments containing the cross-neutralization epitopes of HPV16 L2, we characterized antisera obtained by immunizing two rabbits with each of the ten synthetic peptides of 14 to 20 amino acids (aa) long, which represents a part of the HPV16 L2 sequence from aa 14 to 144. The antisera against the peptides within the region from aa 18 to 144 efficiently bound to HPV16 L1/L2-capsids and neutralized HPV16 pseudovirions, indicating that the region is displayed on the surface of the capsids and contains several neutralization epitopes. Antiserum against the peptide from aa 18 to 38 (anti-P18/38) cross-neutralized HPV18. Anti-P56/75 cross-neutralized HPV18, 31, and 58. Anti-P61/75 and anti-P64/81 cross-neutralized HPV18 and 58. Anti-P96/115 and the antiserum induced by a mutant P96/115 (S and T at aa 101 and 112 were replaced with L and S, respectively) cross-neutralized HPV31 and 58. The mixture of equal volumes of three antisera, anti-P18/38, anti-P56/75, and anti-mutant P96/115, neutralized HPV16, 18, 31, and 58 more efficiently than anti-P56/75 alone, suggesting that there is a synergistic effect of antibodies on the cross-neutralization. The cross-neutralization appears to be correlated with conserved aa sequences among HPV types. The data in this study provide a basis for designing vaccine antigens effective against a broader spectrum of the high-risk HPVs.

Amino Acid Sequence↗

PubMed2006

Sequence analysis of major histocompatibility complex class-II DQB1 (Patr-DQB1) alleles in chimpanzees by polymerase chain reaction-based methods.

The major histocompatibility complex (MHC) class-II genes are described as the genes that encode the antigen-presenting molecule. In particular, functional alleles of MHC class-II genes in nonhuman primates have been analyzed as part of the study of infectious and immune-mediated diseases in animal models and as part of efforts to understand the molecular evolution of human leukocyte antigen. The polymorphisms and sequence analysis of MHC class-II genes in a large number of subjects is necessary for the group management of nonhuman primates. In the present study, we attempted to analyze the DQB1 polymorphism in the common chimpanzee (Pan troglodytes) by exon 2 sequencing. For exact typing of Patr-DQB1 alleles, we carried out polymerase chain reaction-restriction fragment length polymorphism and sequence analysis. In the genomic DNA of 25 chimpanzees, 6 Patr-DQB1 alleles, including 2 new alleles, were detected. Identification and analysis of Patr-DQB1 alleles using this method may contribute to our understanding of Patr-DQB1 allelic diversity in individual chimpanzees and should be useful in facilitating colony management of chimpanzee groups in Japan.

Amino Acid Sequence↗

PubMed2006

Genetic networks responsive to sodium butyrate in colonic epithelial cells.

We performed microarray and computational gene network analyses to identify the detailed mechanisms by which sodium butyrate (SB) induces cell growth arrest and the differentiation of mouse colonic epithelial MCE301 cells. Two thousand six hundred four differentially expressed probe sets were identified in the cells treated with 2mM SB and were classified into four groups. Of these, the gradually increased group and the gradually and remarkably decreased group contained the genetic networks for cellular development and cell cycles or canonical pathways for fatty acid biosynthesis and pyrimidine metabolism, respectively. The present results provide a basis for understanding the detailed molecular mechanisms of action of SB in colonic epithelial cells.

Acetylation↗

PubMed2006

Molecular cloning and sequencing of the cDNA encoding the bat CD4.

Chiroptera is thought to be a vector or a natural reservoir of various pathogenic microbes. However, there are few basic studies on the subject of chiroptera immune systems. This is the first report to determine the sequence of bat CD4 cDNA. Comparison with other animals' CD4 and phylogenetic analysis have shown that bat CD4 had a higher homology to cat and dog CD4 than to human and mouse CD4. Moreover, from the analysis of the structure of the CD4 Ig-like C-type 1 region, in bat CD4 there was an insertion of 18 extra amino acids. In addition, bat CD4 lacked cystein, which suggested that the disulfide bond could not be formed. Human, monkey and mouse CD4 have the cystein and the disulfide bond, but pig, cat, whale and dog CD4, like that of the bat, lacked the cystein. We conducted the present study in order to help elucidate the infectious diseases derived from the bat as well as bat immune systems.

Amino Acid Sequence↗

PubMed2006

Gene expression profiling of mouse embryonic stem cell progeny differentiated by Lumelsky's protocol.

Successful conversion of embryonic stem (ES) cells into insulin-producing cells has been reported by Lumelsky et al. (Science 2001;292:1389-1394); however, it remains controversial. In this study, we investigated the properties of ES cell progeny-induced differentiation according to Lumelsky's protocol by immunocytochemistry, oligonucleotide microarray and real-time RT-PCR. Insulin-positive cells were observed at stages 3, 4 and 5. Microarray analysis demonstrated upregulation and appearance of some genes involved in pancreatic development but not beta-cell-specific functional genes in cells at stage 5. Similarly, real-time RT-PCR revealed that expression of beta-cell-specific functional genes such as islet amyloid polypeptide, insulin I and II was not increased in cells at stage 5. These results suggest that terminal differentiation of ES cell progeny toward functional pancreatic beta-cell is insufficient. This study also demonstrates the usefulness of multiple time-course expression profiles for validating differentiation fates of ES cell progeny.

Animals↗

PubMed2006

Evaluation of clinical efficacy of Maeda's nomogram for vancomycin dosage adjustment in adult Japanese MRSA pneumonia patients.

The clinical efficacy of Maeda's nomogram for vancomycin dosage adjustment was evaluated by comparison with a standard dosage regimen (package insert information: vancomycin dose reduced in elderly patients and patients with renal dysfunction, with Moellering's nomogram used for renal-dysfunction patients) in adult Japanese MRSA pneumonia patients. Using Maeda's nomogram, the vancomycin dose is fixed at 1,000 mg while the dosing interval is varied in accordance with individual creatinine clearance. Using a standard dosage regimen, 5 patients out of 27 (18.5%) achieved target plasma levels of vancomycin (25-40 microg/mL for peak and 5-15 microg/mL for trough) within 2-6 days. Using Maeda's nomogram, 38 patients out of 53 (71.7%) achieved target levels in that time. A higher clinical response (complete resolution of all signs and symptoms of MRSA infection) to vancomycin therapy was also obtained with Maeda's nomogram when evaluated approximately 2-weeks after discontinuation of vancomycin therapy (43.4% versus 18.5% for the standard regimen). In conclusion, the Maeda's nomogram regimen with a 1,000 mg vancomycin dose was shown to achieve target plasma levels of vancomycin at a higher rate and provide higher clinical efficacy in vancomycin therapy of MRSA pneumonia patients, as compared with the currently available standard dosage regimen.

Adult↗

PubMed2006

The critical roles of serum/glucocorticoid-regulated kinase 3 (SGK3) in the hair follicle morphogenesis and homeostasis: the allelic difference provides novel insights into hair follicle biology.

Mutation in the serum/glucocorticoid regulated kinase 3 (Sgk3, also known as Sgkl or Cisk) gene causes both defective hair follicle development and altered hair cycle in mice. We examined Sgk3-mutant YPC mice (YPC-Sgk3(ypc)/Sgk3(ypc)) and found expression of SGK3 protein with altered function. In the hair follicles of YPC mice, the aberrant differentiation and poor proliferation of hair matrix keratinocytes during the period of postnatal hair follicle development resulted in a complete lack of hair medulla and weak hair. Surprisingly, the length of postnatal hair follicle development and anagen term was shown to be dramatically shortened. Also, phosphorylation of GSK3beta at Ser9 and the nuclear accumulation of beta-catenin were reduced in the developing YPC hair follicle, suggesting that phosphorylation of GSK3beta and WNT-beta-catenin pathway takes part in the SGK3-dependent regulation of hair follicle development. Moreover, the above-mentioned features, especially the hair-cycling pattern, differ from those in other Sgk3-null mutant strains, suggesting that the various patterns of dysfunction in the SGK3 protein may result in phenotypic variation. Our results indicate that SGK3 is a very important and characteristic molecule that plays a critical role in both hair follicle morphogenesis and hair cycling.

Alleles↗

PubMed2006

Localization of ubiquitin C-terminal hydrolase L1 in mouse ova and its function in the plasma membrane to block polyspermy.

Protein degradation is essential for oogenesis and embryogenesis. The ubiquitin-proteasome system regulates many cellular processes via the rapid degradation of specific proteins. Ubiquitin carboxyl-terminal hydrolase L1 (UCH-L1) is exclusively expressed in neurons, testis, ovary, and placenta, each of which has unique biological activities. However, the functional role of UCH-L1 in mouse oocytes remains unknown. Here, we report the expression pattern of UCH-L1 and its isozyme UCH-L3 in mouse ovaries and embryos. Using immunocytochemistry, UCH-L1 was selectively detected on the plasma membrane, whereas UCH-L3 was mainly detected in the cytoplasm, suggesting that these isozymes have distinct functions in mouse eggs. To further investigate the functional role of UCH-L1 in mouse eggs, we analyzed the fertilization rate of UCH-L1-deficient ova of gad female mice. Female gad mice had a significantly increased rate of polyspermy in in vitro fertilization assays, although the rate of fertilization did not differ significantly from wild-type mice. In addition, the litter size of gad female mice was significantly reduced compared with wild-type mice. These results may identify UCH-L1 as a candidate for a sperm-oocyte interactive binding or fusion protein on the plasma membrane that functions during the block to polyspermy in mouse oocytes.

Animals↗

PubMed2005

Gestational and lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin affects social behaviors between developing rhesus monkeys (Macaca mulatta).

Pregnant rhesus monkeys (Macaca mulatta) were exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) at 30 and 300 ng/kg by subcutaneous injection at gestational day 20, followed by additional injections of TCDD (1.5 and 15 ng/kg, respectively) every 30 days till 90 days after parturition. The offspring delivered from these experimentally TCDD-exposed mothers were subjected to a series of behavioral tests after the weaning at 12-14 months old (MO): a finger maze learning task (12-15 MO), encounter tests between two monkeys (at 12-15 and 24-27 MO), and an eye-contact test (23-26 MO) to estimate learning ability, social interaction with a peer subject, and interest or hostility to a human observer, respectively. TCDD exposure had no significant effect on learning ability or interest/hostility to an observer. It did, however, significantly affect behavioral characteristics in the encounter tests. In the first encounter test, monkeys exposed to TCDD showed more visual exploration and mutual proximity but less stereotypy behavior compared to control monkeys. In the second encounter test, these differences seemed to disappear, suggesting that the behavioral effects of TCDD exposure in the encounter tests might disappear as the monkey develops. This study produced evidence of the behavioral toxicity of TCDD in social interactions using non-human primates.

Animals↗

PubMed2005

Hair cycle induction by hair plucking in Mini rats.

Jcl:WistarTGN(ARGHGEN)1Nts rat (Mini rat) is a transgenic rat in which the growth hormone (GH) expression is suppressed by the presence of an antisense transgene for the rat GH gene, and the hair cycle of male Mini rats enters a long-lasting telogen phase after 8 weeks old. In the present study, effects of hair plucking on the hair cycle in the dorsal skin of 11-week-old male Mini rats were examined up to 54 days after the hair plucking. As a result, hair plucking brought about an anagen phase, and hair cycle arrest in telogen phase occurred again. Male Mini rats, having follicles in anagen-inducible long-lasting telogen phase, will offer a powerful tool for investigating the molecular nature and organization of the so-called hair cycle clock.

Animals↗

PubMed2005

Human papillomavirus 16 minor capsid protein L2 helps capsomeres assemble independently of intercapsomeric disulfide bonding.

The human papillomavirus (HPV) capsomeres (pentamers of major capsid protein L1), which constitute along with L2 the virion capsid, can assemble themselves alone into the L1-capsid particles in vivo and in vitro, depending on intercapsomeric disulfide bonds. To study a possible role of L2 in capsid assembly, we examined the interaction between HPV16 L2 and capsomeres under the conditions that inhibit the formation of disulfide bonds in vitro and in vivo. The purified L2 bound to free capsomeres prepared by disassembling L1-capsids but not to the L1-capsids in vitro. And the L2 was found to help capsomeres assemble into smaller capsid-like particles independently of intercapsomeric disulfide bonding. Similar particles were obtained from the Sf9 cells co-infected with baculoviruses expressing L2 and an L1 mutant that lacks a C-terminal cysteine (C428S) and can form capsomeres but no capsids when expressed alone. These findings suggest that L2, which is known to bind both viral DNA and L1, may contribute to the formation of the virion by linking viral DNA and capsomeres and by helping capsomeres assemble before the virion capsid structure is completed by dintercapsomeric disulfide bonding.

Animals↗

PubMed2005

Histopathological studies of aortic dissection in streptozotocin-induced diabetic APA hamsters.

Syrian hamsters of the APA strain (APA hamsters) are known to show continuous diabetes accompanied by its complications, such as glomerulosclerosis and atherosclerosis, following a single injection of streptozotocin (SZ). Recently, we observed Stanford type B aortic dissection in three diabetic APA hamsters and histopathological analysis was performed. The histopathologic observations in the false lumen, such as proliferation of granulation tissues, neointima and pseudoneointima, corresponded to the non-thrombosed type of human aortic dissection, and blood clots of the thrombosed type were similar to the remodeling structures of aortic dissection found in human cases. Thus, this model may be useful for investigating the etiology and pathogenesis of aortic dissection accompanying diabetes mellitus in humans.

Aortic Dissection↗

PubMed2005

[A case of colorectal cancer effectively treated with UFT/LV].

5-FU/LV therapy has been standard chemotherapy for advanced and recurrent colorectal cancer. Several studies reported that a new alternative chemotherapy, UFT/LV, had anti-cancer effects the same as with conventional 5-FU/LV therapy. We report a patient who had advanced and recurrent colorectal cancer treated with UFT/ LV. This 70-year-old male was admitted to our hospital because of a right lower abdominal mass, which was diagnosed as a peritoneal recurrence of transverse colon cancer by abdominal CT. UFT/LV therapy was started on an outpatient basis. After one course of chemotherapy, the intra-abdominal mass disappeared, and this therapy was continued for three courses. He did not suffer from any adverse effect during chemotherapy. Although this therapy was resumed because of the recurrence at the same site after nine months, it was refractory to chemotherapy. Thereafter, surgical resection was performed, and it was diagnosed as lymph node metastasis of previous surgery.

Adenocarcinoma↗

PubMed2004

A mutation in the serum and glucocorticoid-inducible kinase-like kinase (Sgkl) gene is associated with defective hair growth in mice.

YPC is a mutant mouse strain with defective hair growth characterized by thin, short hairs and poorly developed hair bulbs and dermal papillae. To identify the gene associated with the phenotype, we performed genome-wide linkage analysis using 1010 backcross progeny and 123 microsatellite markers covering all chromosomes. The mutant locus (ypc) was mapped to a 0.2-cM region in the proximal part of mouse chromosome 1. This 0.2-cM region corresponds to a 450-kb region of genome sequence that contains two genes with known functions and five ESTs or predicted genes with unknown functions. Sequence analysis revealed a single C-to-A nucleotide substitution at nucleotide 1382 in the Sgkl gene, causing a nonsense mutation at codon 461. Sgkl encodes serum and glucocorticoid-inducible kinase-like kinase (SGKL), which belongs to a subfamily of serine/threonine protein kinases and has been suggested to have a role downstream of lipid signals produced by activation of phosphoinositide 3-kinase (PI3K). In the mutant SGKL, a serine residue in the C-terminal end of the protein (Ser486), which is indispensable for activation of SGKL upon phosphorylation, is abolished by premature termination. Specific expression of the Sgkl gene in the inner root sheath of growing hair follicles was also identified by in situ hybridization. Therefore, we concluded that the nucleotide substitution in the Sgkl gene is the causative mutation for defective hair growth in the ypc mutant mouse and that the signaling pathway involving SGKL plays an essential role in mammalian hair development.

Animals↗

PubMed2004

Attention-deficit and hyperactive neurobehavioural characteristics induced by perinatal hypothyroidism in rats.

Thyroid hormone is essential for the proper development of the mammalian central nervous system (CNS). In the present study, we examined behavioural alterations caused by transient perinatal hypothyroidism induced by an anti-thyroid drug, propylthiouracil (PTU). This drug produces perinatal disruption of the thyroid system and subsequent behavioural changes, which we investigated using a series of behavioural tests and focusing particularly on attention-deficit/hyperactivity disorder (ADHD)-like behaviours. In the open field test, both male and female rats that had experienced perinatal hypothyroidism (HT rats) showed an increased percent of locomotion behaviour and reduced grooming behaviour, suggesting that HT rats may be hyperactive and show fewer anxiety characteristics. Neither male nor female HT rats showed retention in the passive avoidance test. Male HT rats showed a significantly lower rate of correct avoidance responses than control rats in earlier sessions in the active avoidance test. In addition, we observed significant increases in the number of times that rats crossed the partition during inter-trial intervals and the percent of failure of avoidance during 5 s electrical stimuli in HT rats, suggesting that HT rats are restless, have a shortened attention span and panic easily. In measuring spontaneous motor activity during a period of darkness, male HT rats appeared to plunge into active phase with short, quick steps, while male control rats showed only long active phases during a stress-free period of darkness. These abnormal behavioural characteristics in HT rats might coincide with those found in some cases of ADHD.

Animals↗

PubMed2004

Developmental regulation of ubiquitin C-terminal hydrolase isozyme expression during spermatogenesis in mice.

The ubiquitin pathway functions in the process of protein turnover in eukaryotic cells. This pathway comprises the enzymes that ubiquitinate/deubiquitinate target proteins and the proteasome that degrades ubiquitin-conjugated proteins. Ubiquitin C-terminal hydrolases (UCHs) are thought to be essential for maintaining ubiquitination activity by releasing ubiquitin (Ub) from its substrates. Mammalian UCH-L1 and UCH-L3 are small proteins that share considerable homology at the amino acid level. Both of these UCHs are highly expressed in the testis/ ovary and neuronal cells. Our previous work demonstrated that UCH-L1-deficient gracile axonal dystrophy (gad) mice exhibit progressively decreasing spermatogonial stem cell proliferation, suggesting that UCH isozymes in the testis function during spermatogenesis. To analyze the expression patterns of UCH isozymes during spermatogenesis, we isolated nearly homogeneous populations of spermatogonia, spermatocytes, spermatids, and Sertoli cells from mouse testes. Western blot analysis detected UCH-L1 in spermatogonia and Sertoli cells, whereas UCH-L3 was detected in spermatocytes and spermatids. Moreover, reverse transcription-polymerase chain reaction analysis of UCH isozymes showed that UCH-L1 and UCH-L4 mRNAs are expressed in spermatogonia, whereas UCH-L3 and UCH-L5 mRNAs are expressed mainly in spermatocytes and spermatids. These results suggest that UCH-L1 and UCH-L3 have distinct functions during spermatogenesis, namely, that UCH-L1 may act during mitotic proliferation of spermatogonial stem cells whereas UCH-L3 may function in the meiotic differentiation of spermatocytes into spermatids.

Animals↗