The destruction of blood-brain barrier (BBB) and blood-nerve barrier (BNB) has been considered to be a key step in the disease process of a number of neurological disorders including cerebral ischemia, Alzheimer's disease, multiple sclerosis, and diabetic neuropathy. Although glial cell line-derived neurotrophic factor (GDNF) and brain-derived neurotrophic factor (BDNF) facilitate neuronal or axonal regeneration in the brain or peripheral nerves, their action in the BBB and BNB remains unclear. The purpose of the present study was to elucidate whether these neurotrophic factors secreted from the brain or peripheral nerve pericytes increase the barrier function of the BBB or BNB, using our newly established human brain microvascular endothelial cell (BMEC) line or peripheral nerve microvascular endothelial cell (PnMEC) line. GDNF increased the expression of claudin-5 and the transendothelial electrical resistance (TEER) of BMECs and PnMECs, whereas BDNF did not have this effect. Furthermore, we herein demonstrate that the GDNF secreted from the brain and peripheral nerve pericytes was one of the key molecules responsible for the up-regulation of claudin-5 expression and the TEER value in the BBB and BNB. These results indicate that the regulation of GDNF secreted from pericytes may therefore be a novel therapeutic strategy to modify the BBB or BNB functions and promote brain or peripheral nerve regeneration.

Sera from NMO patients reduce expression of tight junction proteins and disrupt the BBB. Autoantibodies against BMECs other than anti-AQP4 antibodies may disrupt the BBB through upregulation of VEGF in BMECs.

ABSTRACT. The blood-nerve barrier (BNB) is a highly specialized unit that maintains the microenvironments of the peripheral nervous system. Since the breakdown of the BNB has been considered a key step in autoimmune neuropathies such as Guillain-Barré syndrome and chronic inflammatory demyelinating polyraduculoneuropathy, it is important to understand the cellular properties of the peripheral nerve microvascular endothelial cells (PnMECs) which constitute the BNB. For this purpose, we established an immortalized cell line derived from human PnMECs. The human PnMECs were transduced with retroviral vectors encoding the temperaturesensitive SV40 large T antigen and human telomerase. This cell line, termed FH-BNB, showed a spindle fibershaped morphology, expression of von Willebrand factor and uptake of acetylated low density lipoprotein. These cells expressed tight junction proteins including occludin, claudin-5, ZO-1 and ZO-2 at the cell-cell boundaries. P-glycoprotein and GLUT-1 were also detected by a Western blot analysis and the cells exhibited the functional expression of p-glycoprotein. In addition, transendothelial electrical resistance experiments and paracellular permeabilities of sodium fluorescein and fluorescein isothiocyanate-labeled dextran of molecular weight 4 kDa across these cells demonstrated that FH-BNBs had functional tight junctions. These results indicated that FHBNBs had highly specialized barrier properties and they might therefore be a useful tool to analyze the pathophysiology of various neuropathies.

Carnivora is a successful taxon in terms of dietary diversity. We investigated the dietary adaptations of carnivoran dentition and the developmental background of their dental diversity, which may have contributed to the success of the lineage. A developmental model was tested and extended to explain the unique variability and exceptional phenotypes observed in carnivoran dentition. Carnivorous mammalian orders exhibited two distinct patterns of dietary adaptation in molars and only Carnivora evolved novel variability, exhibiting a high correlation between relative molar size and the shape of the first molar. Studies of Bmp7-hetero-deficient mice, which may exhibit lower Bmp7 expression, suggested that Bmp7 has pleiotropic effects on these two dental traits. Its effects are consistent with the pattern of dietary adaptation observed in Carnivora, but not that observed in other carnivorous mammals. A molecular evolutionary analysis revealed that Bmp7 sequence evolved by natural selection during ursid evolution, suggesting that it plays an evolutionary role in the variation of carnivoran dentition. Using mouse experiments and a molecular evolutionary analysis, we extrapolated the causal mechanism of the hitherto enigmatic ursid dentition (larger M2 than M1 and M3). Our results demonstrate how carnivorans acquired novel dental variability that benefits their dietary divergence.

We previously showed that side population (SP) cells, characterized by specific Hoechst dye efflux pattern in flow cytometric analysis, were present in teleost kidney hematopoietic tissue, and that kidney SP cells were enriched in hematopoietic stem cells (HSCs). ABCG2/Abcg2 is an ATP-binding cassette (ABC) transporter that is known to be associated with Hoechst dye efflux activity of mammalian HSCs. In the present study, we examined the expression and function of Abcg2 in kidney SP cells from zebrafish (Danio rerio). Although the zebrafish genome has 4 paralogous copies of ABCG2 (zAbcg2a, b, c, and d), zAbcg2a and zAbcg2c mRNA was expressed in kidney SP cells. Transfection of COS-7 cells with zAbcg2a and zAbcg2c showed that zAbcg2a was directly associated with the SP phenotype. These results indicate that zAbcg2a mRNA is a useful marker for zebrafish HSCs. In situ hybridization in kidney tissue showed that zAbcg2a-posi- IntroductionSide population (SP) cells are identified from bone marrow based on their capacity to efflux of the fluorescent dye Hoechst 33342 (Hoechst), and are enriched in hematopoietic stem cells (HSCs). 1 Since the Hoechst dye efflux activity of HSCs is widely conserved in mammals, SP cell purification has been extensively used to enrich mammalian HSCs. [2][3][4] Recently, we showed that the hematopoietic activity of teleost SP cells isolated from kidney, the main hematopoietic organ in teleosts, 5,6 using the transplantation model system of clonal ginbuna (Carassius auratus langsdorfii, S3n strain) and ginbuna goldfish (Carassius auratus) hybrids (S4n strain). The SP cell population was clearly identified from ginbuna kidney. When the kidney SP cells from S3n were injected into S4n, all types of donor-derived blood cells (erythrocytes, neutrophils, basophils, monocytes, thrombocytes, and T and B lymphocytes) were detected in the recipient blood over a period of 9 months. 7 These findings indicate that SP cell purification can be used to enrich HSCs from not only mammals but also teleosts.Zebrafish (Danio rerio) has recently emerged as a powerful genetic model in which forward genetic screens can uncover novel genes involved in development, hematopoiesis, and human disease. 8 Although many homologues of human genes, including hematopoietic genes, have been identified, 9,10 stem-cell markers have not been shown in zebrafish. Therefore, little is known about the localization of HSCs and about stem-cell niche, a microenvironment supporting the maintenance and self-renewal of stem cells, in teleost kidney hematopoietic tissue. In murine bone marrow, ABCG2/Abcg2, an ATP-binding cassette (ABC) transporter associated with Hoechst dye efflux activity of HSCs, 11-15 is highly expressed in the most primitive HSCs and is sharply downregulated with differentiation. 11 In addition, the expression of Abcg2 gene in stem cells is highly conserved from various sources such as mouse skin, skeletal muscle, mammary grand, and testis, as well as human bone marrow. 11,[16][17][18] Abcg2 is thus used as a gener...

A method was developed for the preparation of genomic DNA from clotted blood that is usually discarded after extraction, for other laboratory tests. The method, which involves proteinase K digestion, salt/chloroform extraction and 90% ethanol precipitation of DNA from clotted blood, is rapid, sinple, and easy because it does not inpose an extra burden on the patient.

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