DNA Amplification and Nucleotide Sequence Determination of a Region of Mitochondrial DNA in the Sea Snake, Laticauda Semifasciata

We determined the nucleotide sequence of a region of the 12S ribosomal RNA (rRNA) gene in the mitochondrial DNA (mtDNA) of the sea snake, Laticauda semifasciata, using the polymerase chain reaction (PCR). We synthesized oligonucleotide primers according to the nucleotide sequence of human mt DNA 12S rRNA gene and found that the target sequence (386bp) of the sea snake mtDNA could be amplified with these primers. The nucleotide sequence of the amplified region of the sea snake mt DNA was determined on six separate plasmid clones for each individual snake DNA and matched completely among the DNA samples of three sea snakes. The sequence homology in the region of the mtDNA 12S rRNA gene between L. semifasciata and human is 69.1%

Neural Activity Changes Underlying the Working Memory Deficit in Alpha-CaMKII Heterozygous Knockout Mice

The alpha-isoform of calcium/calmodulin-dependent protein kinase II (α-CaMKII) is expressed abundantly in the forebrain and is considered to have an essential role in synaptic plasticity and cognitive function. Previously, we reported that mice heterozygous for a null mutation of α-CaMKII (α-CaMKII+/−) have profoundly dysregulated behaviors including a severe working memory deficit, which is an endophenotype of schizophrenia and other psychiatric disorders. In addition, we found that almost all the neurons in the dentate gyrus (DG) of the mutant mice failed to mature at molecular, morphological and electrophysiological levels. In the present study, to identify the brain substrates of the working memory deficit in the mutant mice, we examined the expression of the immediate early genes (IEGs), c-Fos and Arc, in the brain after a working memory version of the eight-arm radial maze test. c-Fos expression was abolished almost completely in the DG and was reduced significantly in neurons in the CA1 and CA3 areas of the hippocampus, central amygdala, and medial prefrontal cortex (mPFC). However, c-Fos expression was intact in the entorhinal and visual cortices. Immunohistochemical studies using arc promoter driven dVenus transgenic mice demonstrated that arc gene activation after the working memory task occurred in mature, but not immature neurons in the DG of wild-type mice. These results suggest crucial insights for the neural circuits underlying spatial mnemonic processing during a working memory task and suggest the involvement of α-CaMKII in the proper maturation and integration of DG neurons into these circuits

Autoantibodies to insulin, insulinoma-associated antigen-2, and zinc transporter 8 improve the prediction of early insulin requirement in adult-onset autoimmune diabetes

Objective: The aim of this study was to indentify the predictive marker for early insulin requirement in adult-onset autoimmune diabetes in the Japanese populations.Design/Patients: We analyzed insulin autoantibodies (IAA), IA-2 autoantibodies (IA-2icA), and ZnT8 autoantibodies (ZnT8A) by radioimmunoassay in 47 Japanese patients with adult-onset autoimmune diabetes who were identified by native GAD autoantibody (nGADA) screening in ~3,000 non-insulin-requiring diabetes and in 302 nGADA-negative type 2 diabetes. Furthermore, GAD65 autoantibody-specific epitopes were also analyzed using GAD65/GAD67 chimeric constructs.Results: The prevalence of IAA, IA-2icA and ZnT8A in nGADA-positive patients was 26%, 15%, and 19%, respectively, which was significantly higher than that in nGADA-negative type 2 diabetes (2%, 2%, and 2%, P<0.0001). Among nGADA-positive patients, 38% had one or more of IAA, IA-2icA, or ZnT8A, and 15% had two or more of these autoantibodies, compared with none of the nGADA-negative patients (P<0.0001). Thirty-six % of nGADA-positive patients subsequently required insulin therapy, and high nGADA titer (log-rank P=0.003), middle epitope recognition of GAD65A (P=0.002), and the presence of one or more of IAA, IA-2icA, or ZnT8A (P=0.002) at diagnosis marked the risk for early requirement of insulin therapy. Multivariate logistic regression analysis showed the multiple islet autoantibodeis to be independently associated with the risk for insulin requirement (Odds ratio=13.77, 95%CI: 2.77-68.45, P=0.001).Conclusions: These results indicate that the determination of IAA, IA-2icA, and ZnT8A improves the prediction of a future insulin insufficiency in adult-onset autoimmune diabetes, which appears to be superior to GADA titer and GAD65A-specific epitopes

Identification of nesfatin-1 as a satiety molecule in the hypothalamus

The brain hypothalamus contains certain secreted molecules that are important in regulating feeding behaviour. Here we show that nesfatin, corresponding to NEFA/nucleobindin2 (NUCB2), a secreted protein of unknown function, is expressed in the appetite-control hypothalamic nuclei in rats. Intracerebroventricular (i.c.v.) injection of NUCB2 reduces feeding. Rat cerebrospinal fluid contains nesfatin-1, an amino-terminal fragment derived from NUCB2, and its expression is decreased in the hypothalamic paraventricular nucleus under starved conditions. I.c.v. injection of nesfatin-1 decreases food intake in a dose-dependent manner, whereas injection of an antibody neutralizing nesfatin-1 stimulates appetite. In contrast, i.c.v. injection of other possible fragments processed from NUCB2 does not promote satiety, and conversion of NUCB2 to nesfatin-1 is necessary to induce feeding suppression. Chronic i.c.v. injection of nesfatin-1 reduces body weight, whereas rats gain body weight after chronic i.c.v. injection of antisense morpholino oligonucleotide against the gene encoding NUCB2. Nesfatin-1-induced anorexia occurs in Zucker rats with a leptin receptor mutation, and an anti-nesfatin-1 antibody does not block leptin-induced anorexia. In contrast, central injection of alpha-melanocyte-stimulating hormone elevates NUCB2 gene expression in the paraventricular nucleus, and satiety by nesfatin-1 is abolished by an antagonist of the melanocortin-3/4 receptor. We identify nesfatin-1 as a satiety molecule that is associated with melanocortin signalling in the hypothalamus

Humoral immune response to islet autoantigens in Japanese patients with type 1 diabetes.

In this study, we evaluated autoantibodies to IA-2 (IA-2As), glutamic acid decarboxylase 65 (GADAs), and islet cell antibodies (ICAs) in 233 patients with type 1 diabetes (M:F = 90:143, mean duration 4.0 +/- 6.7 yr) as a cross-sectional study. Of 233 patients with type 1 diabetes, IA-2A was detected in 58% of patients with duration within 2 weeks, 61% of patients with duration or=10 yr. These prevalences were similar to those of ICA, while the prevalence of GADA was not influenced by duration of diabetes with positivity of 63-74%. Thus, as the duration of diabetes became longer, the frequency of GADA(+)/IA-2A(-) patients increased and the frequency of GADA(+)/IA-2A(+) patients decreased. However, the frequency of GADA(-)/IA-2A(+) patients was not influenced by duration of diabetes. The prevalence of IA-2A was significantly higher in abrupt-onset group (68%, n= 79) compared to the slowly progressive group (23%, n= 22) in new-onset patients (P= 0.0001). However, there was no difference in the IA-2A frequency between these two groups (abrupt-onset 26%, n= 53 vs. slowly progressive 24%, n= 21) in patients with long-standing disease, suggesting that IA-2A positivity might persist in patients with slowly progressive type 1 diabetes. These results emphasize the heterogeneity of humoral autoimmunity to protein tyrosine phosphatase-like molecules, but not to GAD, in patients with type 1 diabetes

Semaphorin 4D promotes bone invasion in head and neck squamous cell carcinoma

Head and neck squamous cell carcinomas (HNSCCs) frequently invade the bones of the facial skeleton. Semaphorin 4D (Sema4D) is an axon guidance molecule produced by oligodendrocytes. Sema4D was also identified in the bone microenvironment and many cancer tissues including HNSCC. To date, however, the role of Sema4D in cancer-associated bone disease is still unknown. This is the first study to demonstrate the role of Sema4D in bone invasion of cancer. In the clinical tissue samples of bone lesion of HNSCC, Sema4D was detected at high levels, and its expression was correlated with insulin-like growth factor-I (IGF-I) expression. In vitro experiments showed that IGF-I regulates Sema4D expression and Sema4D increased proliferation, migration and invasion in HNSCC cells. Sema4D also regulated the expression of receptor activator of nuclear factor κβ ligand (RANKL) in osteoblasts, and this stimulated osteoclastgenesis. Furthermore, knockdown of Sema4D in HNSCC cells inhibited tumor growth and decreased the number of osteoclasts in a mouse xenograft model. Taken together, IGF-I-driven production of Sema4D in HNSCCs promotes osteoclastogenesis and bone invasion

Combined insulin B:9-23 self-peptide and polyinosinic-polycytidylic acid accelerate insulitis but inhibit development of diabetes by increasing the proportion of CD4+Foxp3+ regulatory T cells in the islets in non-obese diabetic mice.

Insulin peptide B:9-23 is a major autoantigen in type 1 diabetes. Combined treatment with B:9-23 peptide and polyinosinic-polycytidylic acid (poly I:C), but neither alone, induce insulitis in normal BALB/c mice. In contrast, the combined treatment accelerated insulitis, but prevented diabetes in NOD mice. Our immunofluorescence study with anti-CD4/anti-Foxp3 revealed that the proportion of Foxp3 positive CD4(+)CD25(+) regulatory T cells (Tregs) was elevated in the islets of NOD mice treated with B:9-23 peptide and poly I:C, as compared to non-treated mice. Depletion of Tregs by anti-CD25 antibody hastened spontaneous development of diabetes in non-treated NOD mice, and abolished the protective effect of the combined treatment and conversely accelerated the onset of diabetes in the treated mice. These results indicate that poly I:C combined with B:9-23 peptide promotes infiltration of both pathogenic T cells and predominantly Tregs into the islets, thereby inhibiting progression from insulitis to overt diabetes in NOD mice