Inhibition of Neurite Outgrowth by a Neuropilin-1 Binding Peptide Derived from Semaphorin 3A

Semaphorin 3A (Sema3A), an axon guidance molecule, inhibits neurite outgrowth of sensory neurons. Recombinant Sema3A protein has also inhibited scratching behavior and improved skin inflammation in an atopic dermatitis model. In the present study, we investigated whether Sema3A-derived peptides could bind its receptor, neuropilin-1 (NRP1), to inhibit neurite outgrowth. Here, two candidate NRP1-binding (NPB) peptides, NPB7 and NPB15, were found to inhibit NGF-induced survival and neurite outgrowth of PC12 cells and rat primary neurons in serum-free medium. To investigate the preventive effect of the two NPB peptides in vivo, we assessed whether they could inhibit skin inflammation induced by repeated topical application of oxazolone in mice. NPB15 peptide, but not NPB7, inhibited ear swelling. The NPB15 peptide solution and Vaseline ointment groups showed slightly decreased epidermal nerve densities compared with controls. The combination of NPB15 peptide and Vaseline ointment increased the inhibitory effect of NPB15 peptide on epidermal nerve densities. These results suggest that Sema3A-derived peptides can bind to NRP1 and inhibit neurite outgrowth both in vitro and in vivo. Thus, these peptides may be potent candidates for the treatment of atopic dermatitis.     

An analysis of various aspects of atomic bomb dose estimation at RERF using data on acute radiation symptoms

The dose-response curves for acute radiation symptoms reported by atomic bomb survivors are compared by dose estimation method (the method used to calculate the transmission factor), shielding category, and city. Circular symmetry is also investigated. It is found that response rates for acute symptoms differ considerably by dose estimation method and shielding category even after controlling for both gamma and neutron exposure as well as for city, sex, and age at the time of the bomb. One explanation of these results is that the doses of survivors in Japanese type houses estimated by the nine parameter method are subject to less random measurement error, while doses of those survivors who were in the open and shielded by terrain, who were totally shielded by concrete buildings, and who were in factories are subject to especially large random errors. The degree to which systematic bias contributes to these differences could not be determined. These results have important implications for comparisons between cities since Nagasaki includes a far greater proportion of survivors in shielding categories showing weak dose-response relationships than does Hiroshima. The hypothesis that doses might be higher in the westerly direction in Hiroshima is not supported by acute effects analyses, but excess acute effects are found in the north of Hiroshima.     

3D spheroid cultures improve the metabolic gene expression profiles of HepaRG cells

3D (three-dimensional) cultures are considered to be an effective method for toxicological studies; however, little evidence has been reported whether 3D cultures have an impact on hepatocellular physiology regarding lipid or glucose metabolism. In the present study, we conducted physiological characterization of hepatoma cell lines HepG2 and HepaRG cells cultured in 3D conditions using a hanging drop method to verify the effect of culture environment on cellular responses. Apo (Apolipoprotein)B as well as albumin secretion was augmented by 3D cultures. Expression of genes related to not only drug, but also glucose and lipid metabolism were significantly enhanced in 3D cultured HepaRG spheroids. Furthermore, mRNA levels of CYP (cytochrome P450) enzymes following exposure to corresponding inducers increased under the 3D condition. These data suggest that this simple 3D culture system without any special biomaterials can improve liver-specific characteristics including lipid metabolism. Considering that the system enables high-throughput assay, it may become a powerful tool for compound screening concerning hepatocellular responses in order to identify potential drugs.     

Effects of aspirin on gastric mucus glycoprotein in fed and fasted rats

Gastric lesions induced by aspirin increased the ulcer index and incidence with prolongation of fasting time. Aspirin decreased gastric mucus glycoprotein in both the corpus and antrum. However, the rate of decrease in mucus glycoprotein induced by aspirin differed according to feeding habits and the gastric region. Qualitative change in corpus mucus glycoprotein was induced by aspirin.     

Interferon-gamma inhibits the action of B cell stimulatory factor (BSF)-1 on resting B cells

B cell stimulatory factor-1 (BSF-1) stimulates resting B cells to increase in volume and prepares these cells to enter the S phase in response to anti-IgM and other B cell mitogens. Interferon-gamma (IFN-gamma) blocks both the volume enlargement and preparation for DNA synthesis caused by BSF-1, although it has little effect on B cells already stimulated by BSF-1. The capacity of IFN-gamma to inhibit the action of BSF-1 on resting B cells suggests a mutual regulatory interaction between these two T cell-derived products.     

Analysis of adipimidate-crosslinked lysine

The chromatographic conditions for separation of N,N′-bislysyl(?-N)adipamidine and N-lysyl(?-N)adipamidinic acid, which were the products of acid hydrolysis of proteins treated with adipimidate esters, from other amino acids on an amino acid analyzer were established including their ninhydrin color values. Kinetics of decomposition of these lysine derivatives under the conditions of total acid hydrolysis of protein are also reported.     

Role of B cell stimulatory factor 1/interleukin 4 in clonal proliferation of B cells

B cell stimulatory factor 1 (BSF-1)/interleukin 4 (IL-4) has striking effects on colony formation in soft agar by small resting B lymphocytes. BSF-1 alone induces colony formation in this cell population, presumably in costimulation with a mitogenic substance present in bacto-agar. In costimulation with anti-IgM antibodies, BSF-1 caused initial proliferation of 8 to 10% of B cells, resulting in a large number of cell clusters (10 to 40 cells/clone) after 3 to 4 days of incubation. However, substantial number of colonies (greater than 40 cells/clone) developed only from these clusters when IL-1 was added to the cultures. Using a modified immunoperoxidase staining technique for the determination of IgM allotype, evidence was obtained that B cell colonies stimulated with BSF-1 are derived from a single progenitor cell. Neutralization of BSF-1 with 11B11 after a culture period of 1 to 4 days inhibits further proliferation of B cell colonies, indicating that the action of BSF-1 extends for several cell generations beyond initial stimulation from the resting state. Furthermore, it is demonstrated that the synergistic action of IL-1 with BSF-1 is confined to the late culture period, indicating a growth-promoting effect by IL-1 for activated B cells.     

Gastric mucus glycoprotein in different rat strains

The extent of gastric damage induced by aspirin was found to differ according to rat strain. The occurrence of ulcers varied, from high to low, in the following strain order: Donryu, Sprague-Dawley (SD) and Wistar. The content of corpus mucus glycoprotein was essentially the same in all the strains: about 6 mg as hexose of dry tissue. Antral mucus glycoprotein content increased in the order Wistar, SD and Donryu: 7.1, 8.3 and 9.1 mg, respectively. Gastric mucus glycoprotein carbohydrate composition was essentially the same in all three strains. The relatively low proportions of N-acetylglucosamine, galactose and sialic acid from the antrum was a characteristic feature in contrast to mucus glycoprotein from the corpus which contained a high proportion of these sugars.