RESUMO
The Notch signaling pathway is a highly evolutionarily-conserved cell-cell signaling pathway that regulates many events during development. It plays a pivotal role in the regulation of fundamental cellular processes, such as cell proliferation, stem cell maintenance, and differentiation during embryonic and adult development. However, functions of Notch signaling in Aedes aegypti, the major mosquito vector for dengue, are largely unknown. In this study, we identified a unique feature of A. aegypti Notch (AaNotch) in the control of the sterile-like phenotype in female mosquitoes. Silencing AaNotch with a reverse genetic approach significantly reduced the fecundity and fertility of the mosquito. Silencing AaNotch also resulted in the prevention of micropyle formation, which led to impaired fertilization. In addition, JNK phosphorylation (a signaling molecule in the non-canonical Notch signaling pathway) was inhibited in the absence of AaNotch. Furthermore, treatment with a JNK inhibitor in the mosquito resulted in impaired fecundity and fertility. Taken together, our results demonstrate that non-canonical Notch signaling is essential for controlling fertility in the A. aegypti mosquito.
Assuntos
Aedes/fisiologia , Proteínas de Insetos/metabolismo , Receptores Notch/metabolismo , Transdução de Sinais , Aedes/efeitos dos fármacos , Aedes/crescimento & desenvolvimento , Animais , Feminino , Fertilidade , Inativação Gênica , Proteínas de Insetos/genética , Inibidores de Janus Quinases/farmacologia , MAP Quinase Quinase 4/antagonistas & inibidores , MAP Quinase Quinase 4/metabolismo , Óvulo , Fosforilação , Receptores Notch/genética , Genética ReversaRESUMO
Patients who have liver cirrhosis are at increased risk of bacterial infections, such as bacteremia, meningitis, pneumonia, urinary tract infections, and spontaneous bacterial peritonitis, due to immunodeficiency associated with the severity of the cirrhosis. Although bacterial infections are frequent in cirrhotic patients, only isolated cases of brain abscess have been reported. In these cirrhotic patients, the initial presentation of brain abscess may not be fever or leukocytosis, but focal neurologic deficits. In addition, for consideration of blood-brain barrier penetration, the anti-biotic choice postoperatively is also quite different from other infections outside the central nervous system. We will discuss two cases of brain abscess in cirrhotic patients with special emphasis on the clinical presentation, magnetic resonance spectroscopic findings, organism encountered, therapeutic strategy, and prognosis.