998 resultados para Satellite observations
Resumo:
Savary's ulcer is a rare and little known peptic ulcer situated just above Barrett's esophagus. It is predominant in elderly women, bleeds less than Barrett's ulcer and is almost always associated with peptic stenosis. It is, like Barrett's and Wolf's ulcers, a complication of gastroesophageal reflux and not of Barrett's esophagus.
Resumo:
Comprend : Observations
Resumo:
TGF-β and myostatin are the two most important regulators of muscle growth. Both growth factors have been shown to signal through a Smad3-dependent pathway. However to date, the role of Smad3 in muscle growth and differentiation is not investigated. Here, we demonstrate that Smad3-null mice have decreased muscle mass and pronounced skeletal muscle atrophy. Consistent with this, we also find increased protein ubiquitination and elevated levels of the ubiquitin E3 ligase MuRF1 in muscle tissue isolated from Smad3-null mice. Loss of Smad3 also led to defective satellite cell (SC) functionality. Smad3-null SCs showed reduced propensity for self-renewal, which may lead to a progressive loss of SC number. Indeed, decreased SC number was observed in skeletal muscle from Smad3-null mice showing signs of severe muscle wasting. Further in vitro analysis of primary myoblast cultures identified that Smad3-null myoblasts exhibit impaired proliferation, differentiation and fusion, resulting in the formation of atrophied myotubes. A search for the molecular mechanism revealed that loss of Smad3 results in increased myostatin expression in Smad3-null muscle and myoblasts. Given that myostatin is a negative regulator, we hypothesize that increased myostatin levels are responsible for the atrophic phenotype in Smad3-null mice. Consistent with this theory, inactivation of myostatin in Smad3-null mice rescues the muscle atrophy phenotype.
Resumo:
Comprend : Remarques sur le théâtre espagnol
Resumo:
The role of the Hippo pathway effector YAP1 in soft tissue sarcomas is poorly defined. Here we report that YAP1 activity is elevated in human embryonal rhabdomyosarcoma (ERMS). In mice, sustained YAP1 hyperactivity in activated, but not quiescent, satellite cells induces ERMS with high penetrance and short latency. Via its transcriptional program with TEAD1, YAP1 directly regulates several major hallmarks of ERMS. YAP1-TEAD1 upregulate pro-proliferative and oncogenic genes and maintain the ERMS differentiation block by interfering with MYOD1 and MEF2 pro-differentiation activities. Normalization of YAP1 expression reduces tumor burden in human ERMS xenografts and allows YAP1-driven ERMS to differentiate in situ. Collectively, our results identify YAP1 as a potent ERMS oncogenic driver and a promising target for differentiation therapy.