AIM: Atrial fibrosis, one of the most striking features in the pathology of atrial fibrillation (AF), is promoted by local and systemic inflammation. Electrophilic fatty acid nitroalkenes, endogenously generated by both metabolic and inflammatory reactions, are anti-inflammatory mediators that in synthetic form may be useful as drug candidates. Herein we investigate whether an exemplary nitro-fatty acid can limit atrial fibrosis and AF. METHODS AND RESULTS: Wild-type C57BL6/J mice were treated for 2 weeks with angiotensin II (AngII) and vehicle or nitro-oleic acid (10-nitro-octadec-9-enoic acid, OA-NO2, 6 mg/kg body weight) via subcutaneous osmotic minipumps. OA-NO2 significantly inhibited atrial fibrosis and depressed vulnerability for AF during right atrial electrophysiological stimulation to levels observed for AngII-naive animals. Left atrial epicardial mapping studies demonstrated preservation of conduction homogeneity by OA-NO2. The protection from fibrotic remodelling was mediated by suppression of Smad2-dependent myofibroblast transdifferentiation and inhibition of Nox2-dependent atrial superoxide formation. CONCLUSION: OA-NO2 potently inhibits atrial fibrosis and subsequent AF. Nitro-fatty acids and possibly other lipid electrophiles thus emerge as potential therapeutic agents for AF, either by increasing endogenous levels through dietary modulation or by administration as synthetic drugs.

• MeSH
• akční potenciály účinky léků   MeSH
• angiotensin II farmakologie   MeSH
• dusíkaté sloučeniny farmakologie   MeSH
• fibrilace síní prevence a kontrola   MeSH
• fibróza MeSH
• konexin 43 analýza   MeSH
• kultivované buňky MeSH
• kyseliny linolové farmakologie   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• protein Smad2 antagonisté a inhibitory   MeSH
• remodelace síní účinky léků   MeSH
• srdeční síně patologie   MeSH
• transdiferenciace buněk účinky léků   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

BACKGROUND: Tumor heterogeneity and the plasticity of cancer cells present challenges for effective clinical diagnosis and therapy. Such challenges are epitomized by neuroendocrine transdifferentiation (NED) and the emergence of neuroendocrine-like cancer cells in prostate tumors. This phenomenon frequently arises from androgen-depleted prostate adenocarcinoma and is associated with the development of castration-resistant prostate cancer and poor prognosis. RESULTS: In this study, we showed that NED was evoked in both androgen receptor (AR)-positive and AR-negative prostate epithelial cell lines by growing the cells to a high density. Androgen depletion and high-density cultivation were both associated with cell cycle arrest and deregulated expression of several cell cycle regulators, such as p27Kip1, members of the cyclin D protein family, and Cdk2. Dual inhibition of Cdk1 and Cdk2 using pharmacological inhibitor or RNAi led to modulation of the cell cycle and promotion of NED. We further demonstrated that the cyclic adenosine 3', 5'-monophosphate (cAMP)-mediated pathway is activated in the high-density conditions. Importantly, inhibition of cAMP signaling using a specific inhibitor of adenylate cyclase, MDL-12330A, abolished the promotion of NED by high cell density. CONCLUSIONS: Taken together, our results imply a new relationship between cell cycle attenuation and promotion of NED and suggest high cell density as a trigger for cAMP signaling that can mediate reversible NED in prostate cancer cells.

• MeSH
• AMP cyklický metabolismus   MeSH
• androgenní receptory metabolismus   MeSH
• androgeny farmakologie   MeSH
• cyklin-dependentní kinasa 2 metabolismus   MeSH
• cyklin-dependentní kinasy metabolismus   MeSH
• epitelové buňky účinky léků   enzymologie   patologie   MeSH
• imunohistochemie MeSH
• inhibitory proteinkinas farmakologie   MeSH
• kontrolní body buněčného cyklu účinky léků   MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory prostaty patologie   MeSH
• neuroendokrinní buňky účinky léků   patologie   MeSH
• počet buněk MeSH
• signální transdukce účinky léků   MeSH
• transdiferenciace buněk * účinky léků   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Phthalate esters are ubiquitous environmental pollutants widely used as plasticizers, which have been shown to interfere with both endocrine regulation and development of reproductive organs. In the present study, we examined the impact of diethylhexyl phthalate (DEHP) and dibutyl phthalate (DBP) on the proliferation of androgen-sensitive human prostate carcinoma LNCaP cells and related events. The results showed that both compounds were able to inhibit cell cycle progression in a dose-dependent manner. However, only DEHP was found to weakly reduce androgen receptor (AR) protein levels after long-term exposure, while only DBP partially inhibited expression of the prostate-specific antigen (KLK3) gene, a model AR transcriptional target. This indicated that inhibition of cell proliferation was likely independent of any AR modulations. Both phthalates induced suppression of cell proliferation, but none of them affected the levels of markers associated with neuroendocrine transdifferentiation (NED) in LNCaP cells. Taken together, the presented data indicate that phthalates may exert long-term negative effects on the proliferation of prostate epithelial cells derived from the carcinoma model, which are, nevertheless, largely independent of the modulation of AR expression/activity, and which do not alter further processes associated with NED.

• MeSH
• biologické modely * MeSH
• buněčný cyklus účinky léků   MeSH
• dibutylftalát toxicita   MeSH
• diethylhexylftalát toxicita   MeSH
• kyseliny ftalové toxicita   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory prostaty genetika   patologie   MeSH
• neuroendokrinní buňky účinky léků   patologie   MeSH
• počet buněk MeSH
• proliferace buněk účinky léků   MeSH
• prostatický specifický antigen genetika   metabolismus   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• transdiferenciace buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Aims: The aim of this research was to set up an in vitro system to trans-diff erentiate haematopoietic stem cells(HSCs) into embryo-like stem cells in order to de-diff erentiate them. In this more naive state they should be cultivatedmore easily in order to augment them for consecutive diff erentiation and autologous transplantation for use in clinicalpractice. Methods: Using the principle of the methodology of blastocyst injection, HSCs were co-cultivated with mouseembryonic stem cells (mES) with and without cell to cell contact. After co-cultivation HSCs were analyzed by fl owcytometryusing haematopoietic markers (CD34, CD45, CD133) and embryonic stem cell markers (SSEA-4, Tra-1-60,Tra-1-81). Results: No ES cell markers were detected on the former HSCs. A decrease in HSC marker intensity was the onlyfi nding. This implies that no de-diff erentiation took place. Conclusions: We hypothesize that the unnatural situation of a mixture of two cell types originating in diff erentspecies may have led to this outcome. To achieve our goal of in vitro de-diff erentiation we need to use a purely humanculture system without animal additives.

• MeSH
• dediferenciace buněk fyziologie   účinky léků   MeSH
• embryonální kmenové buňky fyziologie   MeSH
• fetální krev fyziologie   MeSH
• financování organizované MeSH
• hematopoetické kmenové buňky fyziologie   MeSH
• imunohistochemie metody   využití   MeSH
• kultivační techniky metody   využití   MeSH
• lidé MeSH
• myši MeSH
• průtoková cytometrie metody   využití   MeSH
• regenerativní lékařství metody   trendy   MeSH
• transdiferenciace buněk fyziologie   účinky léků   MeSH
• Check Tag
• lidé MeSH
• myši MeSH