43 research outputs found
Anterior urethral strictures - actual questions of treatment
The article presents data on modern methods of reconstructive surgery of the anterior urethra stricture. Compared the effectiveness of various methods of graft augmentation urethroplasty techniques (ventral, dorsal, lateral bulbar augmentation urethroplasty, Asopa and Palminteri techniques). Authors give recommendation of technical advantages of using a particular surgery method. Provides information on the graft selection and some features of its fixation. Highlight aspects of the treatment of urethra stricture in the future.В статье представлены данные о современных реконструктивно-пластических методиках хирургического лечения стриктур передней уретры. Представлен анализ данных 66 статей, посвященных сравнению эффективности различных методик заместительной пластики уретры (вентральная, дорсальная, латеральная методика, техники Asopa и Palminteri и др.) и их отдаленных результатов. Даются рекомендации по технике и преимуществам использования той или иной методики. Приведена информация по вопросам выбора трансплантата и так же особенностям его забора и фиксации. Освещены аспекты развития методов лечения стриктурной болезни уретры в будущем
GADD34 keeps the mTOR pathway inactivated in endoplasmic reticulum stress related autophagy
The balance of protein synthesis and proteolysis (i.e. proteostasis) is maintained by a complex regulatory network in which mTOR (mechanistic target of rapamycin serine/threonine kinase) pathway and unfolded protein response are prominent positive and negative actors. The interplay between the two systems has been revealed; however the mechanistic details of this crosstalk are largely unknown. The aim of the present study was to investigate the elements of crosstalk during endoplasmic reticulum stress and to verify the key role of GADD34 in the connection with the mTOR pathway. Here, we demonstrate that a transient activation of autophagy is present in endoplasmic reticulum stress provoked by thapsigargin or tunicamycin, which is turned into apoptotic cell death. The transient phase can be characterized by the elevation of the autophagic marker LC3II/I, by mTOR inactivation, AMP-activated protein kinase activation and increased GADD34 level. The switch from autophagy to apoptosis is accompanied with the appearance of apoptotic markers, mTOR reactivation, AMP-activated protein kinase inactivation and a decrease in GADD34. Inhibition of autophagy by 3-methyladenine shortens the transient phase, while inhibition of mTOR by rapamycin or resveratrol prolongs it. Inhibition of GADD34 by guanabenz or transfection of the cells with siGADD34 results in down-regulation of autophagy-dependent survival and a quick activation of mTOR, followed by apoptotic cell death. The negative effect of GADD34 inhibition is diminished when guanabenz or siGADD34 treatment is combined with rapamycin or resveratrol addition. These data confirm that GADD34 constitutes a mechanistic link between endoplasmic reticulum stress and mTOR inactivation, therefore promotes cell survival during endoplasmic reticulum stress. © 2016 Holczer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Expression of phosphorylated eIF4E-binding protein 1, but not of eIF4E itself, predicts survival in male breast cancer
Background: Male breast cancer is rare and treatment is based on data from females. High expression/activity of eukaryotic initiation factor 4E (eIF4E) denotes a poor prognosis in female breast cancer, and the eIF4E pathway has been targeted therapeutically. eIF4E activity in female breast cancer is deregulated by eIF4E over-expression and by phosphorylation of its binding protein, 4E-BP1, which relieves inhibitory association between eIF4E and 4E-BP1. The relevance of the eIF4E pathway in male breast cancer is unknown. Methods: We have assessed expression levels of eIF4E, 4E-BP1, 4E-BP2 and phosphorylated 4E-BP1 (p4E-BP1) using immunohistochemistry in a large cohort of male breast cancers (n=337) and have examined correlations with prognostic factors and survival. Results: Neither eIF4E expression or estimated eIF4E activity were associated with prognosis. However, a highly significant correlation was found between p4E-BP1 expression and disease-free survival, linking any detectable p4E-BP1 with poor survival (univariate log rank p=0.001; multivariate HR 8.8, p=0.0001). Conclusions: Our data provide no support for direct therapeutic targeting of eIF4E in male breast cancer, unlike in females. However, as p4E-BP1 gives powerful prognostic insights that are unrelated to eIF4E function, p4E-BP1 may identify male breast cancers potentially suitable for therapies directed at the upstream kinase, mTOR
Phosphoproteomics Reveals Resveratrol-Dependent Inhibition of Akt/mTORC1/S6K1 Signaling
Resveratrol, a plant-derived
polyphenol, regulates many cellular
processes, including cell proliferation, aging and autophagy. However,
the molecular mechanisms of resveratrol action in cells are not completely
understood. Intriguingly, resveratrol treatment of cells growing in
nutrient-rich conditions induces autophagy, while acute resveratrol
treatment of cells in a serum-deprived state inhibits autophagy. In
this study, we performed a phosphoproteomic analysis after applying
resveratrol to serum-starved cells with the goal of identifying the
acute signaling events initiated by resveratrol in a serum-deprived
state. We determined that resveratrol in serum-starved conditions
reduces the phosphorylation of several proteins belonging to the mTORC1
signaling pathway, most significantly, PRAS40 at T246 and S183. Under
these same conditions, we also found that resveratrol altered the
phosphorylation of several proteins involved in various biological
processes, most notably transcriptional modulators, represented by
p53, FOXA1, and AATF. Together these data provide a more comprehensive
view of both the spectrum of phosphoproteins upon which resveratrol
acts as well as the potential mechanisms by which it inhibits autophagy
in serum-deprived cells