2-methoxyestradiol enhances p53 protein transduction therapy-associated inhibition of the proliferation of oral cancer cells through the suppression of NFkappaB activity.

Protein transduction therapy using poly-arginine peptide can deliver the biologically active proteins. A previous study showed that 11 poly-arginine fused p53 protein (11R-p53) effectively penetrated across the plasma membrane and inhibited the proliferation of oral cancer cells. However, the intracellular half-life of the delivered protein was less than 36 h. Previous studies also showed that 2-methoxyestradiol (2-ME), an endogenous non-toxic estrogenic metabolite, induces the stabilization of the wild-type p53 protein in human cancer cells posttranscriptionally. In the present study, we examined whether 2-ME induced the stabilization of 11R-p53 and had an inhibitory effect on the proliferation of oral cancer cells. The application of 2-ME significantly enhanced the inhibitory effect of 11R-p53 on the proliferation of oral cancer cells. However, 2-ME had no effect on the intracellular half-life of 11R-p53 in oral cancer cells. Of interest is the finding that 2-ME suppressed the transcriptional activity of NFkappaB, which has an important role in tumorigenesis, but did not affect p53 transcriptional activity. These results suggest that 2-ME synergistically enhances the 11R-p53-induced inhibition of the proliferation of oral cancer cells through the suppression of NFkB transcription.</p

Exposure of mouse to high gravitation forces induces long-term potentiation in the hippocampus.

The central nervous system is highly plastic and has been shown to undergo both transient and chronic adaptive changes in response to environmental influences. The purpose of this study was to investigate the effect of hypergravic field on long-term potentiation (LTP) in the mouse hippocampus. Exposure of mice to 4G fields for 48 h had no effect on input-output coupling during extracellular stimulation of Schaffer collaterals and paired pulse facilitation, suggesting that the hypergravic exposure had no detrimental effect on basal neurotransmission in the hippocampus. However, the exposure to 4G fields for 48 h significantly induced LTP compared with the control mouse hippocampus. In contrast, no significant changes of late-phase LTP (L-LTP) were found in the hippocampi of mice exposed to the hypergravic field. Exposure of mice to 4G fields for 48 h enhanced AMPA receptor phosphorylation but not cyclic AMP-responsive element binding protein (CREB) phosphorylation. These results suggest that exposure to hyperdynamic fields influences the synaptic plasticity in the hippocampus.</p

Regulation of Mitochondrial Dynamics and Neurodegenerative Diseases

Mitochondria are important cellular organelles in most metabolic processes and have a highly dynamic nature, undergoing frequent fission and fusion. The dynamic balance between fission and fusion plays critical roles in mitochondrial functions. In recent studies, several large GTPases have been identified as key molecular factors in mitochondrial fission and fusion. Moreover, the posttranslational modifications of these large GTPases, including phosphorylation, ubiquitination and SUMOylation, have been shown to be involved in the regulation of mitochondrial dynamics. Neurons are particularly sensitive and vulnerable to any abnormalities in mitochondrial dynamics, due to their large energy demand and long extended processes. Emerging evidences have thus indicated a strong linkage between mitochondria and neurodegenerative diseases, including Alzheimer's disease, Parkinson's disease and Huntington's disease. In this review, we will describe the regulation of mitochondrial dynamics and its role in neurodegenerative diseases

Colocalization of oxytocin and phosphorylated form of elongation factor 2 in the rat hypothalamus

Oxytocin (OT) is one of the neuropituitary hormones and is synthesized in the neurons of the paraventricular nucleus (PVN) and supraoptic nucleus (SON). Previous studies have shown that the mRNAs encoding OT are delivered from the soma to both dendrites and axons of the neurons in the PVN and SON. However, it has not been elucidated whether a translational regulation mechanism to enable local synthesis of the hormone exists in the axons of the neurons of PVN and SON. Elongation factor 2 (EF2) is essential for polypeptide synthesis during protein translation. Moreover, phosphorylation of EF2 by EF2 kinase enhances the translation of certain mRNA species. In the present study, in order to shed light on the mechanisms involved in the translational regulation of OT synthesis, we investigated the localization of phosphorylated EF2. Phospho-EF2 was localized in the soma of the neurons in PVN and SON, and in the swellings of the median eminence where axonal tracts of the neurons in the PVN and SON exist. The phosphorylated form was also observed in the rat hypophysis. Moreover, phospho-EF2 and OT were colocalized in a part of the neurons in the PVN and SON. These results suggest that OT may be partially translated in the axons of neurons in the PVN and SON, and then secreted from the pituitary

Bayesian inference to identify crystalline structures for XRD

Crystalline phase structure is essential for understanding the performance and properties of a material. Therefore, this study identified and quantified the crystalline phase structure of a sample based on the diffraction pattern observed when the crystalline sample was irradiated with electromagnetic waves such as X-rays. Conventional analysis necessitates experienced and knowledgeable researchers to shorten the list from many candidate crystalline phase structures. However, the Conventional diffraction pattern analysis is highly analyst-dependent and not objective. Additionally, there is no established method for discussing the confidence intervals of the analysis results. Thus, this study aimed to establish a method for automatically inferring crystalline phase structures from diffraction patterns using Bayesian inference. Our method successfully identified true crystalline phase structures with a high probability from 50 candidate crystalline phase structures. Further, the mixing ratios of selected crystalline phase structures were estimated with a high degree of accuracy. This study provided reasonable results for well-crystallized samples that clearly identified the crystalline phase structures

Immunosuppression for islet transplantation.

The development by the Edmonton group of a sirolimus-based, steroid-free, low-tacrolimus regimen is a significant breakthrough that allows the rate of insulin independence after islet transplantation to increase from 13% to 80% at 1 year ; however, the rate is reduced to 50% at 3 years, attributed to prolonged tacrolimus exposure. Recently, immunosuppression agents such as cyclosporine, mycophenolate mofetil, and the novel agent FTY 720 have been used instead of tacrolimus. Lymphocytedepleting antibodies such as anti-thymocyte globulin, alemtuzumab, and hOKT3gamma 1 (ala, ala) have been launched, and a costimulatory blockade of anti-CD40 monoclonal antibodies and CTLA4-Ig will be attempted in the near future. Moreover, the potential of a novel immunosuppressing peptide could now be realized using new technology called the protein transduction system. In this review, we show some of the most recent contributions to the advancement of knowledge in this field

subacute combined spinal cord degeneration

We report a case of subacute combined spinal cord degeneration (SCD) caused by vegetarianism and autoimmune gastritis, which is rarely reported in Japan, and which showed improvement in symptoms and imaging findings after vitamin B12 administration. As delayed treatment can lead to irreversible damage, we suggest that patients with characteristic abnormal signals in the posterior cervical cord should be examined while considering the possibility that SCD may occur even in the absence of a history of gastrectomy or heavy drinking. We also describe the patient’s reversible abnormal signals in the cerebral white matter on magnetic resonance imaging, indicative of an early sign of leukoencephalopathy associated with vitamin B12 deficiency

Self-assembling A6K peptide nanotubes as a mercaptoundecahydrododecaborate (BSH) delivery system for boron neutron capture t (BNCT)

Boron neutron capture therapy (BNCT) is a tumor selective therapy, the effectiveness of which depends on sufficient 10B delivery to and accumulation in tumors. In this study, we used self-assembling A6K peptide nanotubes as boron carriers and prepared new boron agents by simple mixing of A6K and BSH. BSH has been used to treat malignant glioma patients in clinical trials and its drug safety and availability have been confirmed; however, its contribution to BNCT efficacy is low. A6K nanotube delivery improved two major limitations of BSH, including absence of intracellular transduction and non-specific drug delivery to tumor tissue. Varying the A6K peptide and BSH mixture ratio produced materials with different morphologies—determined by electron microscopy—and intracellular transduction efficiencies. We investigated the A6K/BSH 1:10 mixture ratio and found high intracellular boron uptake with no toxicity. Microscopy observation showed intracellular localization of A6K/BSH in the perinuclear region and endosome in human glioma cells. The intracellular boron concentration using A6K/BSH was almost 10 times higher than that of BSH. The systematic administration of A6K/BSH via mouse tail vein showed tumor specific accumulation in a mouse brain tumor model with immunohistochemistry and pharmacokinetic study. Neutron irradiation of glioma cells treated with A6K/BSH showed the inhibition of cell proliferation in a colony formation assay. Boron delivery using A6K peptide provides a unique and simple strategy for next generation BNCT drugs

Proliferation of parathyroid cells negatively correlates with expression of parathyroid hormone–related protein in secondary parathyroid hyperplasia

Proliferation of parathyroid cells negatively correlates with expression of parathyroid hormone-related protein in secondary parathyroid hyperplasia.BackgroundParathyroid hormone–related protein (PTHrP) is now suspected to act as an autocrine or paracrine regulator of cell growth or differentiation, although it was originally reported as a hypercalcemic substance in malignancies. This study was performed to assess the relationship between PTHrP expression and cell proliferation in human parathyroid glands.MethodsThe localization of PTH and PTHrP was studied in 42 samples of hyperplastic parathyroid from 14 long-term hemodialysis cases with immunohistochemistry and in situ hybridization. Results were compared with proliferative activity (proliferating cell nuclear antigen index: counts of proliferating cell nuclear antigen-positive cells/100 cells). The localization of the PTH/PTHrP receptor was also examined. Ten normal glands were studied as controls.ResultsIn hyperplasia, cells positive for PTH, PTHrP, or both were observed immunohistochemically. The areas expressing PTHrP mRNA completely coincided with those positive for PTHrP immunohistochemically. Oxyphilic or transitional oxyphilic cells were consistently positive for PTHrP. PTH/PTHrP receptors were located in the cytoplasmic membrane in most parathyroid cells. Proliferating cell nuclear antigen-positive cells were rare in normal glands with an index of 0.22 ± 0.09 (mean ± sem). They were significantly increased in hyperplastic cases but less for PTHrP-positive than for -negative cells (1.25 ± 0.16 as compared with 7.80 ± 0.52; P < 0.0001).ConclusionThe observed low level of proliferation of PTHrP-positive cells suggests a functional role for PTHrP as a possible growth suppressor in the human parathyroid

CaM kinase Iα–induced phosphorylation of Drp1 regulates mitochondrial morphology

Mitochondria are dynamic organelles that frequently move, divide, and fuse with one another to maintain their architecture and functions. However, the signaling mechanisms involved in these processes are still not well characterized. In this study, we analyze mitochondrial dynamics and morphology in neurons. Using time-lapse imaging, we find that Ca2+ influx through voltage-dependent Ca2+ channels (VDCCs) causes a rapid halt in mitochondrial movement and induces mitochondrial fission. VDCC-associated Ca2+ signaling stimulates phosphorylation of dynamin-related protein 1 (Drp1) at serine 600 via activation of Ca2+/calmodulin-dependent protein kinase Iα (CaMKIα). In neurons and HeLa cells, phosphorylation of Drp1 at serine 600 is associated with an increase in Drp1 translocation to mitochondria, whereas in vitro, phosphorylation of Drp1 results in an increase in its affinity for Fis1. CaMKIα is a widely expressed protein kinase, suggesting that Ca2+ is likely to be functionally important in the control of mitochondrial dynamics through regulation of Drp1 phosphorylation in neurons and other cell types