Association study between interleukin-12 receptor beta1/beta2 genes and type 1 diabetes or asthma in the Japanese population

Interleukin-12 (IL-12) secreted from macrophages or dendritic cells plays an important role in the protection against intracellular pathogens as well as the developmental commitment of T helper 1 cells. IL-12 exerts its biological effects through binding to specific IL-12 receptors (IL-12Rs) termed IL-12Rbeta1 and IL 12Rbeta2. In this paper, we performed association studies between the three reported polymorphisms (Q214R, M365T and G378R) of the IL-12Rbeta1 gene or the newly identified polymorphisms (P238L, IVS9 -7G>A, IVS13 -121G>A, A643T, P779P and c.3283T>G) of the IL-12Rbeta2 gene, and the development of type 1 diabetes or atopic asthma as representative Th1- and Th2- dominant diseases, respectively. The association study of each polymorphism of the IL-12Rbeta1 or IL-12Rbeta2 gene and type 1 diabetes or asthma showed that these IL-12R genes did not contribute to the development of type 1 diabetes or asthma in the Japanese population. Further analysis in individuals with susceptibility to intracellular pathogens may elucidate the importance of the IL-12R genes.     

Localization of Microtubule-Associated Protein (MAP) 1B in the Postsynaptic Densities of the Rat Cerebral Cortex

1. Although microtubule-associated protein (MAP) 1B and its phosphorylation have been suggested to be important for synapse formation among cortical neurons, the localization of MAP1B in synapses has not yet been confirmed. In this report, we examine the localization of MAP1B in synaptic regions. 2. The localization of MAP1B was observed by immunohistochemical and electron microscopic techniques using specific antibodies against MAP1B. 3. MAP1B immunoreactivities were widely distributed in the cerebral cortex and were observed in the postsynaptic area but not in presynaptic terminals. 4. These synapses were classified as the asymmetrical type. 5. Only some synapses exhibited MAP1B immunoreactivities. MAP1B-immunopositive synapses accounted for about half of the total synapses. 6. Such a localization suggests MAP1B's important roles in synaptic functions.     

Hormone replacement therapy decreases insulin resistance and lipid metabolism in Japanese postmenopausal women with impaired and normal glucose tolerance

OBJECTS: To investigate the effect of combined estrogen and progesterone therapy on insulin resistance (IR) and carbohydrate and lipid metabolism in postmenopausal women (PMW) with impaired (IGT) and normal glucose tolerance (NGT). METHODS: Sixteen Japanese PMW with IGT and 33 with NGT received daily oral hormone replacement therapy (HRT; 0.625 mg of conjugated equine estrogen plus 2.5 mg of medroxyprogesterone acetate) for 12 months. As controls, 13 Japanese PMW with IGT and 31 with NGT were enrolled and not treated by HRT. Fasting plasma glucose (FPG), fasting immunoreactive insulin (IRI), and IR were measured in each subject at study initiation and 12 months later. We used homeostasis model assessment (HOMA) to determine IR. RESULTS: FPG and HOMA IR were decreased in both HRT groups, and fasting IRI was reduced in the HRT-NGT group. In controls, FPG, fasting IRI, and HOMA IR were unaltered. Total and low-density lipoprotein cholesterol were decreased and high-density lipoprotein cholesterol was increased in both HRT groups, but triglyceride was unchanged. In controls, lipid metabolism was unaltered. CONCLUSION: HRT decreased IR and improved carbohydrate and lipid metabolism in Japanese PMW with IGT and NGT. These beneficial effects argue for the use of HRT in PMW with IGT as well as NGT.     

Firing activities of neurosecretory cells producing diapause hormone and its related peptides in the female silkmoth,Bombyx mori. II. mandibular and maxillary cells

A gene encoding a precursor polyprotein of diapause hormone (DH) and four related peptides is expressed by three groups of neurosecretory cells in the suboesophageal ganglion (SOG) of Bombyx mori. Long-term chronic recordings of firing activities were made from a common axonal tract (the maxillary nerve) of two groups of cells localized in the mandibular and maxillary neuromeres of SOG during pupal-adult development. Mandibular and maxillary cells usually produced a cluster of action potentials at an interval of 30-60 min during pupal-adult development and there was no significant difference in the firing activity profile between diapause-egg and non-diapause-egg producers. We suggest that rather than DH secretion, pupal mandibular and maxillary cells are involved in the secretion of DH-related neuropeptides. DH secretion seems to be assigned to the third group of cells (labial cells); hence, there may be different posttranslational processing of the precursor polyprotein in different neurosecretory cell groups.     

Firing activities of neurosecretory cells producing diapause hormone and its related peptides in the female silkmoth,Bombyx mori. I. labial cells

There are three known clusters of neurosecretory cells expressing a gene encoding diapause hormone (DH) and four related peptides in the suboesophageal ganglion (SOG) of Bombyx mori. Long-term chronic recordings were made from the axonal tract (NCC-3) of a pair of cells localized in the labial (posterior) neuromere of SOG during pupal-adult development. There was a significant difference in firing activity patterns of the labial neurosecretory cells between diapause-egg and non-diapause-egg producers: labial cells in the former were active throughout pupal-adult development, whereas the same cells in the latter usually maintained an inactive state until the last quarter of pupal-adult development, a time at which a secretion of DH seems to be too late to act on the developing ovary for the induction of diapausing eggs. This observation strongly supports the notion that labial cells release DH and are responsible for determination of embryonic diapause in the silkmoth.     

Polycation liposome enhances the endocytic uptake of photosensitizer into cells in the presence of serum

To construct a novel drug delivery carrier that possesses high therapeutic efficacy with low dosage, we designed polyethylenimine-modified liposome (polycation liposome, PCL) and examined the entrapment of photosensitizer, benzoporphyrin derivative monoacid ring A (BPD-MA), for antiangiogenic photodynamic therapy (PDT). Photosensitizer entrapped in PCLs showed enhanced phototoxicity for a human vascular endothelial cell line, ECV304, in comparison with that for nonmodified control liposome. Interestingly, phototoxicity of control liposomal BPD-MA was suppressed in the presence of serum, but PCL maintained the phototoxicity in the presence of serum following PCL-mediated PDT treatment due to the stability of PCL and the reduced detachment of encapsulated photosensitizer from liposome to serum. In fact, PCL enhanced the uptake level of BPD-MA to ECV304 cells despite the presence or absence of serum. Since polycation modification enhances bioavailability of the liposomal photosensitizer and this property is maintained in the presence of serum, PCL would be useful for antiangiogenic PDT.     

Growth of large polymer-actin complexes

Polymer-actin complexes as large as 10-50 microm with filamentous, branched, stranded, and ring shapes are obtained when fluorescent phalloidin-labeled F-actin is mixed with some synthetic polymers carrying positive charges such as poly-L-lysine, x,y-ionene bromide polymers. All growth of these complexes occurs cooperatively at some certain critical polymer concentrations, regardless of the chemical structure of the polymer, while the morphology of the complexes is substantially influenced by the chemical structure of the polymer. Poly-Lys-actin complex grows preferentially along the filament axis even above the critical concentration. 3,3-ionene-actin complexes show completely homogeneous filaments below the critical concentration but forms bundles at a higher concentration. Occasionally, ring shape complexes can be observed in the 6,6-ionene-actin complex.     

Synthesis and biological activity of sulphostin analogues, novel dipeptidyl peptidase IV inhibitors

The structure of sulphostin (1), a novel dipeptidyl peptidase IV (DPP-IV) inhibitor, is consisted of three key functional groups, including a characteristic amino(sulfoamino)phosphinyl group, on a piperidine ring. To examine the relationship between its structure and the inhibitory activity against DPP-IV, various analogues were synthesized and their activities were investigated. These results indicated that all of the functional groups on the piperidine ring were crucial to the DPP-IV inhibitory activity of sulphostin, and that the sulfonic acid group, which constructed the amino(sulfoamino)phosphinyl group, contributed to the stability of the compound. Moreover, those functional groups should be adjoined on the piperidine ring for the inhibitory activity. The size of the nitrogen-containing heterocyclic ring including piperidine appeared to scarcely affect the activity. In the present study, the sulfonic acid-deficient five-membered ring analogue 27a showed the strongest inhibitory activity (IC50=11 nM).     

Identification of genes regulating colorectal carcinogenesis by using the algorithm for diagnosing malignant state method

We studied the expression profiles of various stages of colorectal tumors (adenoma (AD), seven samples; carcinoma (CA), 16 samples) by using cDNA microarrays and developed ADMS (algorithm for diagnosing malignant state) method, selecting 335 clones characteristic of CA state. We, then, applied ADMS to 12 additional samples (five from primary lesions with metastasis and seven metastases); all 16 CAs and 12 metastatic tumors were diagnosed correctly as cancerous states. Although three of the seven ADs were diagnosed as "cancerous," the large size of two of these tumors suggested their potential malignancy. Our strategy for selecting clones characteristic of the malignant state is widely applicable to diagnosis and for predicting the stage of progression during multistep carcinogenesis. Of the 335 clones we selected, 135 were known genes. Included in the 135 genes were tumor suppressor and growth factor-related genes and were consistent with the literature. ADMS is a reliable means for identifying genes useful for the diagnosis of cancer.     

Glucosylceramide synthesis and synthase expression protect against ceramide-induced stress

Ceramides (Cers), critical for epidermal barrier function, also can inhibit keratinocyte proliferation, while glucosylceramides (GlcCers) exert pro-mitogenic effects. Since alterations in Cer-to-GlcCer ratios appear to modulate cellular growth versus apoptosis, we assessed whether keratinocytes up-regulate GlcCer synthesis as a protective mechanism against Cer-induced stress. Exogenous sphingomyelinase (SMase) treatment of cultured human keratinocytes (CHK) initially decreased proliferation and cellular sphingomyelin (50-60% decrease; P < 0.001), and increased Cer levels (6.1- to 6.8-fold; P < 0.001). Proliferation recovered to normal rates by 24 h, in parallel with increased cellular GlcCer. Both GlcCer synthesis and GlcCer synthase activity increased significantly by 8 h following SMase (8.2- and 2.4-fold, respectively; P < 0.01 each vs. control), attributed to antecedent increases in GlcCer synthase mRNA and protein expression. Further evidence that GlcCer production is responsible for normalized CHK proliferation includes: a) attenuation of SMase-induced inhibition of proliferation by exogenous GlcCer; and b) enhancement of the SMase effect in cells cotreated with the GlcCer synthase inhibitor, PDMP (D-threo-1-phenyl-2(decanoylamino)-3-morpholino-1-propanol). Finally, although proliferation in immortalized, nontransformed keratinocytes (HaCaT) also was inhibited by SMase, HaCaT cells that overexpress GlcCer synthase were resistant to this effect. Thus, SMase-induced stress initiates a response in keratinocytes that includes upregulation of GlcCer synthesis which may protect against the deleterious effects of excess Cer.