Mast Cells Stimulated with Peptidoglycan from Staphylococcus aureus Augment the Development of Th1 Cells.

BACKGROUND: The skin of patients with atopic dermatitis (AD) is superficially colonized by Staphylococcus aureus. We have previously found that percutaneous permeation of peptidoglycan (PEG) from S. aureus increases the number of mast cells in the dermis, as seen in skin lesions of AD patients. The purpose of the present study was to clarify the influence of PEG on T helper type 1 (Th1)/ T helper type 2 (Th2) cell development mediated by mast cells. METHODS: Mast cells were induced by long-term culture of murine spleen cells in medium supplemented with tumor necrosis factor (TNF)- a. Ovalbumin (OVA) peptide-pulsed mast cells were incubated with naïve Th cells in the presence or absence of PEG. Five days later, Th cells in the culture were stimulated with phorbol 12-myristate 13-acetate (PMA) and ionomycin, and Th1/Th2 cytokine production was investigated by enzyme-linked immunosorbent assay. RESULTS: It was confirmed that the mast cells we obtained had surface expression of I-Ad, worked as antigen-presenting cells, and induced Th1 cell and Th2 cell development. The stimulation of mast cells with PEG enhanced the development of Th1 cells but not that of Th2 cells. The increase of Th1 cell development stimulated by PEG was associated with an increase in the expression of Notch ligand Delta 1 in the mast cells. Furthermore, treatment of mast cells with the macrolide antibiotic josamycin suppressed Th1 cell development and this was correlated with a reduction of both Delta 1 expression and interleukin (IL)-12 production in mast cells. CONCLUSIONS: Colonization of S. aureus on the lesioned skin of AD patients contributes to not only an increase in the number of mast cells but also Th1 cell development mediated by mast cells in the dermis and subsequent induction of chronic inflammation, which is characterized by up-regulation of the Th1 cytokine, interferon (IFN)- g. Therefore, application of josamycin to the lesional skin of AD patients may provide relief from chronic inflammation mediated by mast cells.

Eicosapentaenoic acid reduces warfarin-induced arterial calcification in rats.

BACKGROUND: Eicosapentaenoic acid (EPA), a major n-3 polyunsaturated fatty acid, is reported to have various protective effects for cardiovascular disease. However, few studies have focused on the influence of EPA on vascular calcification. METHODS AND RESULTS: Arterial medial calcification (AMC) was induced by administering warfarin (3 mg/g food) and vitamin K1 (1.5 mg/g food) for 2 weeks in Sprague-Dawley rats (control group), and EPA (1 g/kg/day) was administered for 2 weeks simultaneously with warfarin and vitamin K1 (EPA group) or after initiation of AMC (late EPA group). EPA showed a marked reduction of medial calcification in the EPA group, and showed a similar effect in the late EPA group. Immunohistochemical and RT-PCR analyses showed that EPA lowered the expression of osteogenetic markers, such as osteopontin, alkaline phosphatase and core binding factor-α1 in the aorta. Significant migration of macrophages with expression of matrix-metalloproteinase (MMP)-2 or MMP-9 was observed in the aortic adventitia around calcification. EPA also reduced macrophage infiltration, MMP-9 expression as well as gene expression of monocyte chemotactic protein (MCP)-1. CONCLUSIONS: These observations indicate that EPA attenuates arterial medial calcification through an effect associated with the suppression of MMP-9 activity and inhibition of macrophage infiltration as well as osteogenic protein expression in warfarin-induced rat models.

Histopathological aspects of cardiac biopsy in pediatric patients with dilated cardiomyopathy.

BACKGROUND: Dilated cardiomyopathy (DCM) is a heart muscle disease with cardiac dysfunction and a heterogeneous disorder. This disease may show various histopathological aspects of the myocardium, but little is known about these in children. METHODS: Histopathological findings of endomyocardial biopsy from 20 pediatric patients with DCM were analyzed and compared with those in adult patients. RESULTS: Advanced histopathology, including myocytolysis and/or fragmentation of muscle bundles, was frequently observed in patients with poor prognosis. Patchy fibrosis was predominantly demonstrated in the pediatric patients, whereas perivascular fibrosis was mostly observed in the older adults. The myocarditic index, assessed in terms of the findings of fibrosis, size variation of myocytes, disarrangement of muscle bundles and mononuclear cell infiltration was higher in the pediatric patients than in the older adults (P < 0.05). Bizarre myocardial hypertrophy with disorganization, which tends to be frequently demonstrated in hypertrophic cardiomyopathy, was revealed in 30% of the pediatric patients, whereas it was disclosed in none of the older adult patients (P < 0.05). CONCLUSION: These results suggest that the major pathogenetic factors of DCM in children may be different from those in adults.

Recombinant bovine zona pellucida glycoproteins ZP3 and ZP4 coexpressed in Sf9 cells form a sperm-binding active hetero-complex.

The zona pellucida (ZP) is a transparent envelope that surrounds the mammalian oocyte and mediates species-selective sperm-egg interactions. Porcine and bovine ZPs are composed of the glycoproteins ZP2, ZP3, and ZP4. We previously established an expression system for porcine ZP glycoproteins (ZPGs) using baculovirus in insect Sf9 cells. Here we established a similar method for expression of bovine ZPGs. The recombinant ZPGs were secreted into the medium and purified by metal-chelating column chromatography. A mixture of bovine recombinant ZP3 (rZP3) and rZP4 coexpressed in Sf9 cells exhibited inhibitory activity for bovine sperm-ZP binding similar to that of a native bovine ZPG mixture, whereas neither bovine rZP3 nor rZP4 inhibited binding. An immunoprecipitation assay revealed that the coexpressed rZP3/rZP4 formed a hetero-complex. We examined the functional domain structure of bovine rZP4 by constructing ZP4 mutants lacking the N-terminal domain or lacking both the N-terminal and trefoil domains. When either of these mutant proteins was coexpressed with bovine rZP3, the resulting mixtures exhibited inhibitory activity comparable to that of the bovine rZP3/rZP4 complex. Hetero-complexes of bovine rZP3 and porcine rZP4, or porcine rZP3 and bovine rZP4, also inhibited bovine sperm-ZP binding. Our results demonstrate that the N-terminal and trefoil domains of bovine rZP4 are dispensable for formation of the sperm-binding active bovine rZP3/rZP4 complex and, furthermore, that the molecular interactions between rZP3 and rZP4 are conserved in the bovine and porcine systems.

Crystallization and preliminary X-ray analysis of human S100A13.

S100A13 is a member of the S100 family of EF-hand-containing calcium-binding proteins and plays an important role in the secretion of fibroblast growth factor-1 and interleukin 1alpha, two pro-angiogenic factors released by the endoplasmic reticulum/Golgi-independent non-classical secretory pathway. Human S100A13 was heterologously expressed in Escherichia coli, purified and crystallized by the hanging-drop vapour-diffusion method using PEG 3350 as the precipitant. The crystals diffracted X-rays from a synchrotron-radiation source to 1.8 A resolution and the space group was assigned as primitive orthorhombic P2(1)2(1)2(1).

Recombinant porcine zona pellucida glycoproteins expressed in Sf9 cells bind to bovine sperm but not to porcine sperm.

The zona pellucida, which surrounds the mammalian oocyte, consists of the ZPA, ZPB, and ZPC glycoproteins and plays roles in species-selective sperm-egg interactions via its carbohydrate moieties. In the pig, this activity is conferred by tri- and tetraantennary complex type chains; in cattle, it is conferred by a chain of 5 mannose residues. In this study, porcine zona glycoproteins were expressed as secreted forms, using the baculovirus-Sf9 insect cell system. The sperm binding activities of the recombinant proteins were examined in three different assays. The assays clearly demonstrated that recombinant ZPB bound bovine sperm weakly but did not bind porcine sperm; when recombinant ZPC was also present, bovine sperm binding activity was greatly increased, but porcine sperm still was not bound. The major sugar chains of ZPB were pauci and high mannose type chains that were similar in structure to the major neutral N-linked chain of the bovine zona. In fact, the nonreducing terminal alpha-mannose residues were necessary for the sperm binding activity. These results show that the carbohydrate moieties of zona glycoproteins, but not the polypeptide moieties, play an essential role in species-selective recognition of porcine and bovine sperm. Moreover, Asn to Asp mutations at either of two of the N-glycosylation sites of ZPB, residue 203 or 220, significantly reduced the sperm binding activity of the ZPB/ZPC mixture, whereas a similar mutation at the third N-glycosylation site, Asn-333, had no effect on binding. These results suggest that the N-glycans located in the N-terminal half of the ZP domain of porcine ZPB are involved in sperm-zona binding.