RESUMO
Substance P (SP) selectively activates mast cells that reside in connective tissues. We studied the reactions of bone marrow-derived mast cells (BMMC) of three mouse strains, cultured with or without fibroblasts. BMMC co-cultured with fibroblasts, but not those cultured alone, increased intracellular Ca(2+), released LTB(4) and histamine in response to SP. PD098059 significantly inhibited the release of LTB(4), but not histamine in all strains. SB203580 failed to reduce or slightly impaired the release of LTB(4). These results suggest that mast cells undergo maturation under the influence of fibroblasts, acquiring the responsiveness to SP with Ca(2+) signals and predominantly ERK-MAP kinase.
Assuntos
Sinalização do Cálcio/efeitos dos fármacos , Leucotrieno B4/metabolismo , Mastócitos/efeitos dos fármacos , Mastócitos/metabolismo , Substância P/imunologia , Substância P/farmacologia , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Cálcio/metabolismo , Sinalização do Cálcio/imunologia , Técnicas de Cocultura , Inibidores Enzimáticos/farmacologia , Fibroblastos/citologia , Flavonoides/farmacologia , Liberação de Histamina/efeitos dos fármacos , Imidazóis/farmacologia , Masculino , Mastócitos/citologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Células NIH 3T3 , Piridinas/farmacologia , Especificidade da Espécie , Substância P/metabolismoRESUMO
Immortal mast cell lines, such as RBL-2H3 and HMC-1 cells, are commonly utilized to investigate the function of mast cells. However, they are tumor cells carrying a gain-of-function mutation of Kit. We established an immortal mast cell line without Kit mutation, NCL-2, derived from NC mouse bone marrow. NCL-2 cells could be maintained without additional growth factors and thus could respond to exogenous growth signals. Moreover, NCL-2 cells expressed FcεRI and KIT, and release histamine and LTB4 in response to antigen stimulation. This cell line could be a useful tool to analyze proliferation, differentiation, and function of normal mast cells.
RESUMO
We describe the fourth reported case involving "Mycobacterium ulcerans subsp. shinshuense." Compared to previous cases, the infection was more invasive with extensive ulceration from the elbow to the forearm. Definitive identification involved IS2404 detection, 16S rRNA gene sequencing, and analysis of the 16S rRNA gene 3'-terminal region and the virulence plasmid pMUM001.