Východiska: Metastazování, relaps a rezistence k chemoterapii jsou celosvětově hlavními důvody většiny úmrtí na malignitu. Proces metastazování je velmi precizně organizovaný a orgánově specifický. Mechanizmy metastazování nejsou stále přesně známy, ale některé z nich jsou zprostředkovány programem epitelo-mezenchymální tranzice (EMT). Poprvé byl tento proces popsán v průběhu embryogeneze. Tento buněčný program vede ke změně epiteliálního fenotypu buňky v mezenchymální typ. V průběhu této tranzice dochází ke změně tvaru epiteliální buňky, která ztrácí svoji polaritu, závislost na buněčných spojích a celou řadu epiteliálních markerů. Naopak získává vřetenovitý tvar a stává se mechanicky odolnější a je schopnější vycestovat z buněčné kolonie. Tato změna fenotypu je provázena i změnou exprese proteinů a genů, jako jsou transkripční faktory, cadheriny, cateniny, matrix metaloproteinázy nebo receptory pro růstové faktory. Známky aktivace programu EMT byly již popsány v různých typech nádorů, např. u karcinomu prsu, vaječníků, karcinomu tlustého střeva a jícnu, a jejich přítomnost byla asociována s horší prognózou onemocnění a častějším metastatickým šířením. Také rezistence k cytostatické léčbě je spojována s reaktivací těchto embryonálních procesů. Porozumění tomuto programu je nezbytné k lepšímu chápání procesu progrese maligního onemocnění, stejně jako k hledání nových léčebných cílů a prognostických faktorů. Závěr: Tento článek shrnuje dosud známé molekulární kaskády zapojené do procesu EMT u nádorových onemocnění.

Background: Metastasis, recurrence, and resistance to chemotherapy are leading causes of the majority of cancer-related mortality worldwide. The process of metastasis can be artificially divided into a series of sequential, highly organized, and organ-specific steps. The underlying mechanisms are still poorly understood, but are believed to be mediated by epithelial-mesenchymal transition (EMT). First described in embryogenesis, EMT is a cellular reprogramming process in which epithelial cells acquire a mesenchymal phenotype. During this transformation, epithelial cells lose their shape, epithelial markers, and ability to grow in colonies. They acquire a spindle-shaped morphology and exhibit more motile and invasive behavior. These phenotypic changes are associated with modifications in different interconnected protein and gene families, such as transcription factors, cadherins, catenins, matrix metalloproteases, and growth receptors. EMT has been observed in many cancers, such as breast, ovarian, colon, and esophageal cancers, and is associated with poor prognosis and metastasis. Also, resistance to cytotoxic treatments is associated with reactivation of embryonic programs. Understanding this process is necessary to provide a better understanding of cancer progression and could lead to the development of new therapeutic or prognostic strategies for the treatment of cancer. Conclusion: This article summarizes the known molecular pathways involved in EMT in cancer.

• MeSH
• epitelo-mezenchymální tranzice * fyziologie   účinky léků   MeSH
• fenotyp MeSH
• hojení ran MeSH
• kadheriny fyziologie   MeSH
• karcinom patologie   MeSH
• lékové interakce MeSH
• lidé MeSH
• metastázy nádorů * patofyziologie   MeSH
• mikro RNA fyziologie   MeSH
• nádorová transformace buněk MeSH
• neurální trubice fyziologie   MeSH
• proliferace buněk fyziologie   MeSH
• receptory Notch MeSH
• signální dráha Wnt fyziologie   MeSH
• transkripční faktory fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

BACKGROUND: Natural bioproducts are invaluable resources in drug discovery. Isoquinoline alkaloids of Chelidonium majus constitute a structurally diverse family of natural products that are of great interest, one of them being their selectivity for human telomeric G-quadruplex structure and telomerase inhibition. METHODS: The study focuses on the mechanism of telomerase inhibition by stabilization of telomeric G-quadruplex structures by berberine, chelerythrine, chelidonine, sanguinarine and papaverine. Telomerase activity and mRNA levels of hTERT were estimated using quantitative telomere repeat amplification protocol (q-TRAP) and qPCR, in MCF-7 cells treated with different groups of alkaloids. The selectivity of the main isoquinoline alkaloids of Chelidonium majus towards telomeric G-quadruplex forming sequences were explored using a sensitive modified thermal FRET-melting measurement in the presence of the complementary oligonucleotide CT22. We assessed and monitored G-quadruplex topologies using circular dichroism (CD) methods, and compared spectra to previously well-characterized motifs, either alone or in the presence of the alkaloids. Molecular modeling was performed to rationalize ligand binding to the G-quadruplex structure. RESULTS: The results highlight strong inhibitory effects of chelerythrine, sanguinarine and berberine on telomerase activity, most likely through substrate sequestration. These isoquinoline alkaloids interacted strongly with telomeric sequence G-quadruplex. In comparison, chelidonine and papaverine had no significant interaction with the telomeric quadruplex, while they strongly inhibited telomerase at transcription level of hTERT. Altogether, all of the studied alkaloids showed various levels and mechanisms of telomerase inhibition. CONCLUSIONS: We report on a comparative study of anti-telomerase activity of the isoquinoline alkaloids of Chelidonium majus. Chelerythrine was most effective in inhibiting telomerase activity by substrate sequesteration through G-quadruplex stabilization. GENERAL SIGNIFICANCE: Understanding structural and molecular mechanisms of anti-cancer agents can help in developing new and more potent drugs with fewer side effects. Isoquinolines are the most biologically active agents from Chelidonium majus, which have shown to be telomeric G-quadruplex stabilizers and potent telomerase inhibitors.

• MeSH
• alkaloidy farmakologie   MeSH
• benzofenantridiny farmakologie   MeSH
• Chelidonium chemie   MeSH
• cirkulární dichroismus MeSH
• G-kvadruplexy * MeSH
• isochinoliny farmakologie   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• molekulární modely MeSH
• rezonanční přenos fluorescenční energie metody   MeSH
• telomerasa antagonisté a inhibitory   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Advanced atherosclerotic changes can often resist even to very aggressive treatment. Although basic mechanisms of its origin and development are known, some important steps in this process are still waiting for more detailed explanation. Therefore, in addition to already proved aggressive lowering of LDL cholesterol, appropriate timing of atherosclerosis treatment is of the essence. Revealing different stages of atherosclerotic process, less or more sensitive to treatment is of primary importance; however, its detection is complicated by several facts including not exactly identifiable periods of quiescence and progression of atherosclerotic process. One of populations, study of which could add valuable information regarding this problem, are women in menopausal transition. Previously unsuccessful therapy with hormone replacement therapy is restudied with focus on the time of/after menopause. Now, it is supposed to be favorable in women soon, approximately less than 8 years, after menopause. In addition, the same principle - optimal timing of the intervention of traditional cardiovascular risk factors, especially lipids, could be also of importance. Therefore, menopausal transition could be optimal period for the intervention in women at risk. However, this approach is to be proved by evidence from controlled prospective studies focused on lifestyle and/or pharmacological intervention.

• MeSH
• ateroskleróza diagnóza   metabolismus   prevence a kontrola   MeSH
• časové faktory MeSH
• hormonální substituční terapie metody   trendy   MeSH
• kardiovaskulární nemoci diagnóza   metabolismus   prevence a kontrola   MeSH
• lidé MeSH
• menopauza účinky léků   metabolismus   MeSH
• postmenopauza účinky léků   metabolismus   MeSH
• rizikové faktory MeSH
• rozvrh dávkování léků MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

SIGNIFICANCE: Machine learning is increasingly being applied to the classification of microscopic data. In order to detect some complex and dynamic cellular processes, time-resolved live-cell imaging might be necessary. Incorporating the temporal information into the classification process may allow for a better and more specific classification. AIM: We propose a methodology for cell classification based on the time-lapse quantitative phase images (QPIs) gained by digital holographic microscopy (DHM) with the goal of increasing performance of classification of dynamic cellular processes. APPROACH: The methodology was demonstrated by studying epithelial-mesenchymal transition (EMT) which entails major and distinct time-dependent morphological changes. The time-lapse QPIs of EMT were obtained over a 48-h period and specific novel features representing the dynamic cell behavior were extracted. The two distinct end-state phenotypes were classified by several supervised machine learning algorithms and the results were compared with the classification performed on single-time-point images. RESULTS: In comparison to the single-time-point approach, our data suggest the incorporation of temporal information into the classification of cell phenotypes during EMT improves performance by nearly 9% in terms of accuracy, and further indicate the potential of DHM to monitor cellular morphological changes. CONCLUSIONS: Proposed approach based on the time-lapse images gained by DHM could improve the monitoring of live cell behavior in an automated fashion and could be further developed into a tool for high-throughput automated analysis of unique cell behavior.

• MeSH
• algoritmy MeSH
• časosběrné zobrazování MeSH
• epitelo-mezenchymální tranzice * MeSH
• holografie * MeSH
• strojové učení MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• antipsychotika * terapeutické užití   MeSH
• lidé MeSH
• psychotické poruchy * farmakoterapie   prevence a kontrola   MeSH
• rizikové faktory MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Cell death is one of the most important mechanisms of maintaining homeostasis in our body. Ferroptosis and pyroptosis are forms of necrosis-like cell death. These cell death modalities play key roles in the pathophysiology of cancer, cardiovascular, neurological diseases, and other pathologies. Transition metals are abundant group of elements in all living organisms. This paper presents a summary of ferroptosis and pyroptosis pathways and their connection to significant transition metals, namely zinc (Zn), copper (Cu), molybdenum (Mo), lead (Pb), cobalt (Co), iron (Fe), cadmium (Cd), nickel (Ni), mercury (Hg), uranium (U), platinum (Pt), and one crucial element, selenium (Se). Authors aim to summarize the up-to-date knowledge of this topic.In this review, there are categorized and highlighted the most common patterns in the alterations of ferroptosis and pyroptosis by transition metals. Special attention is given to zinc since collected data support its dual nature of action in both ferroptosis and pyroptosis. All findings are presented together with a brief description of major biochemical pathways involving mentioned metals and are visualized in attached comprehensive figures.This work concludes that the majority of disruptions in the studied metals' homeostasis impacts cell fate, influencing both death and survival of cells in the complex system of altered pathways. Therefore, this summary opens up the space for further research.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• Klíčová slova
• mitochondriální pór přechodné propustnosti,
• MeSH
• akutní nekrotizující pankreatitida patologie   MeSH
• Alzheimerova nemoc etiologie   MeSH
• amyotrofická laterální skleróza etiologie   MeSH
• buňky metabolismus   MeSH
• Huntingtonova nemoc etiologie   MeSH
• ionty chemie   MeSH
• kardiovaskulární nemoci MeSH
• mitochondriální membrány patologie   MeSH
• mitochondrie fyziologie   patologie   MeSH
• nealkoholová steatóza jater etiologie   MeSH
• oxidační stres MeSH
• Parkinsonova nemoc etiologie   MeSH
• reperfuzní poškození myokardu farmakoterapie   MeSH
• Reyeův syndrom etiologie   MeSH
• salicylany toxicita   MeSH
• syndromy suchého oka etiologie   MeSH
• vápník chemie   metabolismus   MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH

The oocyte-to-embryo transition (OET) arguably initiates with formation of a primordial follicle and culminates with reprogramming of gene expression during the course of zygotic genome activation. This transition results in converting a highly differentiated cell, i.e. oocyte, to undifferentiated cells, i.e. initial blastomeres of a preimplantation embryo. A plethora of changes occur during the OET and include, but are not limited to, changes in transcription, chromatin structure, and protein synthesis; accumulation of macromolecules and organelles that will comprise the oocyte's maternal contribution to the early embryo; sequential acquisition of meiotic and developmental competence to name but a few. This review will focus on transcriptional and post-transcriptional changes that occur during OET in mouse because such changes are likely the major driving force for OET. We often take a historical and personal perspective, and highlight how advances in experimental methods often catalyzed conceptual advances in understanding the molecular bases for OET. We also point out questions that remain open and therefore represent topics of interest for future investigation.

• MeSH
• buněčná diferenciace fyziologie   MeSH
• embryonální vývoj fyziologie   MeSH
• genom MeSH
• myši MeSH
• oocyty fyziologie   MeSH
• ovariální folikul fyziologie   MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, N.I.H., Intramural MeSH

BACKGROUND: Leishmania development in sand flies is confined to the alimentary tract and is closely connected with blood meal digestion. Previously, it has been published that activities of sand fly midgut proteases are harmful to Leishmania, especially to amastigote-promastigote transition forms. However, our experiments with various Leishmania-sand fly pairs gave quite opposite results. METHODS: We evaluated the effect of semi-digested midgut content on different life stages of Leishmania donovani and Leishmania major in vitro. Various morphological forms of parasites, including macrophage-derived amastigotes and transition forms, were incubated 2 h with midguts dissected at various intervals (6-72 h) post-blood meal or with commercially available proteinase, and their viability was determined using flow cytometry. In parallel, using amastigote-initiated experimental infections, we compared development of L. donovani in sand flies that are either susceptible (Phlebotomus argentipes and P. orientalis) or refractory (P. papatasi and Sergentomyia schwetzi) to this parasite. RESULTS: In vitro, sand fly midgut homogenates affected L. major and L. donovani in a similar way; in all sand fly species, the most significant mortality effect was observed by the end of the blood meal digestion process. Surprisingly, the most susceptible Leishmania stages were promastigotes, while mortality of transforming parasites and amastigotes was significantly lower. Parasites were also susceptible to killing by rabbit blood in combination with proteinase, but resistant to proteinase itself. In vivo, L. donovani developed late-stage infections in both natural vectors; in P. argentipes the development was much faster than in P. orientalis. On the other hand, in refractory species P. papatasi and S. schwetzi, promastigotes survived activity of digestive enzymes but were lost during defecation. CONCLUSIONS: We demonstrated that Leishmania transition forms are more resistant to the killing effect of semi-digested blood meal than 24 h-old promastigotes. Data suggest that Leishmania mortality is not caused directly by sand fly proteases, we assume that this mortality results from toxic products of blood meal digestion. Survival of L. donovani promastigotes in refractory sand flies until blood meal defecation, together with similar mortality of Leishmania parasites incubated in vitro with midgut homogenates of susceptible as well as refractory species, contradict the previously raised hypotheses about the role of midgut proteases in sand fly vector competence to Leishmania.

• MeSH
• gastrointestinální trakt enzymologie   parazitologie   MeSH
• králíci MeSH
• krev metabolismus   MeSH
• Leishmania donovani fyziologie   MeSH
• Leishmania major fyziologie   MeSH
• Phlebotomus parazitologie   MeSH
• proteasy metabolismus   MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Oocyte-to-embryo transition is a process during which an oocyte ovulates, is fertilized, and becomes a developing embryo. It involves the first major genome reprogramming event in life of an organism where gene expression, which gave rise to a differentiated oocyte, is remodeled in order to establish totipotency in blastomeres of an early embryo. This remodeling involves replacement of maternal RNAs with zygotic RNAs through maternal RNA degradation and zygotic genome activation. This review is focused on expression and function of long noncoding RNAs (lncRNAs) and small RNAs during oocyte-to-embryo transition in mammals. LncRNAs are an assorted rapidly evolving collection of RNAs, which have no apparent protein-coding capacity. Their biogenesis is similar to mRNAs including transcriptional control and post-transcriptional processing. Diverse molecular and biological roles were assigned to lncRNAs although most of them probably did not acquire a detectable biological role. Since some lncRNAs serve as precursors for small noncoding regulatory RNAs in RNA silencing pathways, both types of noncoding RNA are reviewed together.

• MeSH
• blastomery chemie   MeSH
• gastrulace MeSH
• lidé MeSH
• malá nekódující RNA genetika   MeSH
• RNA dlouhá nekódující genetika   MeSH
• savci embryologie   genetika   MeSH
• stabilita RNA MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH