The number of revertants with restored ability to form colony increases in a time-dependent manner during long-term selective starvation of dense mutant microbial cultures. This is due to starvation-associated (also called adaptive) mutations that arise in a replication independent manner. Here we report that in Saccharomyces cerevisiae the frequency of starvation-associated reversions of mutant genes whose products are necessary for amino acids biosynthesis are influenced by Ras2/cAMP signaling pathway. This signaling pathway is a yeast general regulatory pathway involved in nutritional sensing, UV response, sporulation control and life span control and its changes are manifested in both, cell cycle and life cycle. Inactivation of the RAS2 gene causes an increase in number of starvation-associated revertants in comparison to an isogenic wild type strain and a strain with constitutively activated Ras2/cAMP signaling pathway. Therefore, we suggest that starvation-associated mutagenesis is different from spontaneous mutagenesis and is related to the cellular capacity to adopt distinct physiological states in response to environmental signals.

• MeSH
• AMP cyklický metabolismus   MeSH
• fungální proteiny * MeSH
• kultivační média MeSH
• lysin metabolismus   MeSH
• mutace MeSH
• mutageneze * MeSH
• Ras proteiny genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny * MeSH
• Saccharomyces cerevisiae fyziologie   MeSH
• signální transdukce MeSH
• tryptofan metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• AMP cyklický MeSH
• fungální proteiny * MeSH
• kultivační média MeSH
• lysin MeSH
• Ras proteiny MeSH
• RAS2 protein, S cerevisiae MeSH Prohlížeč
• Saccharomyces cerevisiae - proteiny * MeSH
• tryptofan MeSH

The signaling pathway mediated by Wingless-type (Wnt) proteins is highly conserved in evolution. This pivotal pathway is known to regulate cell fate decisions, cell proliferation, morphology, migration, apoptosis, differentiation and stem cell self-renewal. It currently includes the canonical or Wnt/beta-catenin pathway in which Wnt proteins bind to 'frizzled' receptors, which leads to downstream activation of gene transcription by beta-catenin. Second, the noncanonical or beta-catenin-independent pathways are now known to be mediated by three possible mechanisms: (1) the Wnt/Ca(2+) pathway, (2) the Wnt/G protein signaling pathway, and (3) the Wnt/PCP or planar cell polarity pathway. Wnt signaling is implicated at several stages of mammary gland growth and differentiation, and possibly in the involution of mammary gland following lactation. Recent evidence suggests the role of Wnt signaling in human breast cancer involves elevated levels of nuclear and/or cytoplasmic beta-catenin using immunohistochemistry, overexpression or downregulation of specific Wnt proteins, overexpression of CKII and sFRP4, downregulation of WIF-1 and sFRP1, as well as amplification of DVL-1. Further research is required to determine how Wnt signaling is involved in the development of different histological types of breast cancer and whether it promotes the viability of cancer stem cells or not.

• MeSH
• lidé MeSH
• mléčné žlázy lidské růst a vývoj   metabolismus   MeSH
• nádorová transformace buněk genetika   metabolismus   MeSH
• nádory prsu genetika   metabolismus   MeSH
• proteiny Wnt genetika   metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• proteiny Wnt MeSH

AIM: Valproic acid (VPA) is a widely-used anticonvulsant and mood-stabilizing agent. VPA is also known to inhibit histone deacetylases (HDACs) affecting the expression of numerous genes. METHODS: In the present study, we examined the effect of VPA on the extracellular signal-related kinase (ERK, p42/p44) pathway (Ras-Raf-MEK-ERK) belonging to the mitogen-activated protein kinases (MAPKs) pathways in primary human hepatocytes. In the liver, the pathway is associated with progression of hepatocellular carcinoma. RESULTS: We found that VPA in a therapeutically relevant concentration (500 µM) activates the ERK pathway, as indicated by increased ERK Thr202/Tyr204 phosphorylation. Interestingly, a prototype HDAC inhibitor, trichostatin A, also activated ERK phosphorylation in primary human hepatocytes. These data suggest that HDAC inhibition might be the primary stimulus for ERK pathway activation in primary human hepatocytes. Notably, U0126, a MEK1 inhibitor, was ineffective in inhibiting ERK pathway activation, likely due to its metabolic deactivation in metabolically competent primary human hepatocytes. CONCLUSION: We conclude that VPA activates the ERK pathway in primary human hepatocytes.

• MeSH
• fosforylace účinky léků   MeSH
• hepatocyty účinky léků   metabolismus   MeSH
• inhibitory histondeacetylas farmakologie   MeSH
• kultivované buňky MeSH
• kyselina valproová farmakologie   MeSH
• kyseliny hydroxamové farmakologie   MeSH
• lidé MeSH
• MAP kinasový signální systém účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibitory histondeacetylas MeSH
• kyselina valproová MeSH
• kyseliny hydroxamové MeSH
• trichostatin A MeSH Prohlížeč

Establishment of asymmetry along the left-right (LR) body axis in vertebrates requires interplay between Nodal and Bmp signaling pathways. In the basal chordate amphioxus, the left-sided activity of the Nodal signaling has been attributed to the asymmetric morphogenesis of paraxial structures and pharyngeal organs, however the role of Bmp signaling in LR asymmetry establishment has not been addressed to date. Here, we show that Bmp signaling is necessary for the development of LR asymmetric morphogenesis of amphioxus larvae through regulation of Nodal signaling. Loss of Bmp signaling results in loss of the left-sided expression of Nodal, Gdf1/3, Lefty and Pitx and in gain of ectopic expression of Cerberus on the left side. As a consequence, the larvae display loss of the offset arrangement of axial structures, loss of the left-sided pharyngeal organs including the mouth, and ectopic development of the right-sided organs on the left side. Bmp inhibition thus phenocopies inhibition of Nodal signaling and results in the right isomerism. We conclude that Bmp and Nodal pathways act in concert to specify the left side and that Bmp signaling plays a fundamental role during LR development in amphioxus.

• Klíčová slova
• Amphioxus, Bmp signaling, Left-right asymmetry, Mouth, Nodal pathway,
• MeSH
• embryo nesavčí cytologie   embryologie   MeSH
• faktory určující pravo-levou symetrii biosyntéza   MeSH
• kopinatci cytologie   embryologie   MeSH
• kostní morfogenetické proteiny metabolismus   MeSH
• protein nodal metabolismus   MeSH
• signální transdukce fyziologie   MeSH
• vývojová regulace genové exprese fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• faktory určující pravo-levou symetrii MeSH
• kostní morfogenetické proteiny MeSH
• protein nodal MeSH

In melanoma and other cancers, invasion, epithelial-to-mesenchymal transition, metastasis and cancer stem cell maintenance are regulated by transcription factors including the Snail family. Slug (Snail2) protein generally supports migration and apoptosis resistance. However, its role in melanoma is not completely understood. The present study investigated the transcriptional regulation of the SLUG gene in melanoma. It demonstrated that SLUG is under the control of the Hedgehog/GLI signaling pathway and is activated predominantly by the transcription factor GLI2. The SLUG gene promoter contains a high number of GLI-binding sites. Slug expression is activated by GLI factors in reporter assays and inhibited by GANT61 (GLI inhibitor) and cyclopamine (SMO inhibitor). SLUG mRNA levels are lowered by GANT61 as assessed by reverse transcription-quantitative PCR. Chromatin immunoprecipitation revealed abundant binding of factors GLI1-3 in the four subregions of the proximal SLUG promoter. Notably, melanoma-associated transcription factor (MITF) is an imperfect activator of the SLUG promoter in reporter assays, and downregulation of MITF had no effect on endogenous Slug protein levels. Immunohistochemical analysis confirmed the above findings and showed MITF-negative regions in metastatic melanoma that were positive for GLI2 and Slug. Taken together, the results demonstrated a previously unrecognized transcriptional activation mechanism of the SLUG gene, which may represent its main regulation of expression in melanoma cells.

• Klíčová slova
• GLI family zinc finger, Hedgehog signaling, Slug, melanoma, melanoma-associated transcription factor,
• MeSH
• apoptóza MeSH
• lidé MeSH
• melanom * genetika   MeSH
• proteiny hedgehog * genetika   MeSH
• signální transdukce MeSH
• transkripční faktory genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• proteiny hedgehog * MeSH
• transkripční faktory MeSH

Acute liver failure (ALF) is known for extremely high mortality rate, the result of widespread damage of hepatocytes. Orthotopic liver transplantation is the only effective therapy but its application is limited by the scarcity of donor organs. Given the importance in the liver biology of Wnt/beta-catenin signaling pathway, we hypothesized that its stimulation could enhance hepatocyte regeneration and attenuate the course of thioacetamide (TAA)-induced ALF in Lewis rats. Chronic treatment with Wnt agonist was started either immediately after hepatotoxic insult ("early treatment") or when signs of ALF had developed ("late treatment"). Only 23 % of untreated Lewis rats survived till the end of experiment. They showed marked increases in plasma alanine aminotransferase (ALT) activity and bilirubin and ammonia (NH3) levels; plasma albumin decreased significantly. "Early" and "late" Wnt agonist treatment raised the final survival rate to 69 % and 63 %, respectively, and normalized ALT, NH3, bilirubin and albumin levels. In conclusion, the results show that treatment with Wnt agonist attenuates the course of TAA-induced ALF in Lewis rats, both with treatment initiated immediately after hepatotoxic insult and in the phase when ALF has already developed. Thus, the pharmacological stimulation of Wnt/beta-catenin signaling pathway can present a new approach to ALF treatment.

• MeSH
• akutní selhání jater chemicky indukované   farmakoterapie   metabolismus   MeSH
• beta-katenin metabolismus   MeSH
• játra účinky léků   metabolismus   MeSH
• potkani inbrední LEW MeSH
• preklinické hodnocení léčiv MeSH
• proteiny Wnt agonisté   MeSH
• signální dráha Wnt účinky léků   MeSH
• thioacetamid MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-katenin MeSH
• proteiny Wnt MeSH
• thioacetamid MeSH

Thioacetamide (TAA) is widely used in the production of drugs, pesticides and dyeing auxiliaries. Moreover, it is a chemical that can cause liver damage and cancer. TAA has recently been identified to cause bone damage in animal models. However, the type of bone damage that TAA causes and its potential pathogenic mechanisms remain unclear. The toxic effects of TAA on the femurs of New Zealand white rabbits and the underlying toxicity mechanism were investigated in this study. Serum samples, the heart, liver, kidney and femurs were collected from rabbits after intraperitoneal injection of TAA for 5 months (100 and 200 mg/kg). The New Zealand white rabbits treated with TAA showed significant weight loss and femoral shortening. The activities of total bilirubin, total bile acid and gamma-glutamyl transpeptidase in the serum were increased following treatment with TAA. In addition, thinned cortical bone and significantly decreased trabecular thickness of TAA-treated rabbits was observed, which was accompanied by significantly decreased mineral density of the cortical and trabecular bone. Moreover, there was a significant decrease in modulus of elasticity and maximum load on bone stress in TAA-treated rabbits. The western blotting results showed that the expression of phosphorylated (p)-p38 and p-ERK in femur tissues of rabbits were increased after TAA administration. Collectively, these results suggested that TAA may lead to femoral damage in rabbits by activating the p38/ERK signaling pathway.

• MeSH
• femur MeSH
• játra * metabolismus   MeSH
• králíci MeSH
• MAP kinasový signální systém MeSH
• signální transdukce MeSH
• thioacetamid * MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• thioacetamid * MeSH

BACKGROUND: Autosomal-dominant mutations in the Park8 gene encoding Leucine-rich repeat kinase 2 (LRRK2) have been identified to cause up to 40% of the genetic forms of Parkinson's disease. However, the function and molecular pathways regulated by LRRK2 are largely unknown. It has been shown that LRRK2 serves as a scaffold during activation of WNT/β-catenin signaling via its interaction with the β-catenin destruction complex, DVL1-3 and LRP6. In this study, we examine whether LRRK2 also interacts with signaling components of the WNT/Planar Cell Polarity (WNT/PCP) pathway, which controls the maturation of substantia nigra dopaminergic neurons, the main cell type lost in Parkinson's disease patients. METHODS: Co-immunoprecipitation and tandem mass spectrometry was performed in a mouse substantia nigra cell line (SN4741) and human HEK293T cell line in order to identify novel LRRK2 binding partners. Inhibition of the WNT/β-catenin reporter, TOPFlash, was used as a read-out of WNT/PCP pathway activation. The capacity of LRRK2 to regulate WNT/PCP signaling in vivo was tested in Xenopus laevis' early development. RESULTS: Our proteomic analysis identified that LRRK2 interacts with proteins involved in WNT/PCP signaling such as the PDZ domain-containing protein GIPC1 and Integrin-linked kinase (ILK) in dopaminergic cells in vitro and in the mouse ventral midbrain in vivo. Moreover, co-immunoprecipitation analysis revealed that LRRK2 binds to two core components of the WNT/PCP signaling pathway, PRICKLE1 and CELSR1, as well as to FLOTILLIN-2 and CULLIN-3, which regulate WNT secretion and inhibit WNT/β-catenin signaling, respectively. We also found that PRICKLE1 and LRRK2 localize in signalosomes and act as dual regulators of WNT/PCP and β-catenin signaling. Accordingly, analysis of the function of LRRK2 in vivo, in X. laevis revelaed that LRKK2 not only inhibits WNT/β-catenin pathway, but induces a classical WNT/PCP phenotype in vivo. CONCLUSIONS: Our study shows for the first time that LRRK2 activates the WNT/PCP signaling pathway through its interaction to multiple WNT/PCP components. We suggest that LRRK2 regulates the balance between WNT/β-catenin and WNT/PCP signaling, depending on the binding partners. Since this balance is crucial for homeostasis of midbrain dopaminergic neurons, we hypothesize that its alteration may contribute to the pathophysiology of Parkinson's disease.

• Klíčová slova
• CELSR1, DVL, Dopaminergic neurons, Endocytosis, Immunoprecipitation, PRICKLE1, Parkinson’s disease, Signalosomes, Substantia nigra, WNT/planar cell polarity,
• MeSH
• beta-katenin metabolismus   MeSH
• dopaminergní neurony metabolismus   MeSH
• kadheriny metabolismus   MeSH
• lidé MeSH
• LRRK2 genetika   metabolismus   MeSH
• mutace genetika   MeSH
• polarita buněk fyziologie   MeSH
• protein-serin-threoninkinasy metabolismus   MeSH
• proteomika metody   MeSH
• signální dráha Wnt fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• beta-katenin MeSH
• CELSR1 cadherin, human MeSH Prohlížeč
• CTNNB1 protein, human MeSH Prohlížeč
• integrin-linked kinase MeSH Prohlížeč
• kadheriny MeSH
• LRRK2 protein, human MeSH Prohlížeč
• LRRK2 MeSH
• protein-serin-threoninkinasy MeSH

BACKGROUND AND AIMS: Glucocorticoids and the GR serve as an essential molecular mediator of stress and different physiologic processes. This review summarizes main findings from studies on the role of the GC/GR signaling in the modulation of genes for nutrient processing by the different organs involved in metabolic diseases. METHODS: Descriptive review of relevant papers known to the author was conducted. RESULTS: Several high-throughput screenings in the past 15 years have identified potential GR DNA-binding regions in different cell types with genes that are annotated to be important for the control of metabolism. Transcriptional regulation of these GC-responsive genes provides links between the hypothalamic-pituitary-adrenal axis (HPA) and systemic energy homeostasis in both physiological and pathophysiological states. Future studies must reconsider the use of agonist, the utilization of animal models of stress and metabolic disorders, and validation in humans. CONCLUSION: This review recapitulates the significant role of the GC/GR signaling in molecular metabolic control and metabolic disorders. Potential future research focus and optimizations have also been identified.

• Klíčová slova
• Glucocorticoid receptor, Glucocorticoids, Metabolic disorders, Metabolism,
• MeSH
• fyziologický stres * MeSH
• glukokortikoidy metabolismus   MeSH
• lidé MeSH
• metabolické nemoci etiologie   metabolismus   patologie   MeSH
• signální transdukce * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• glukokortikoidy MeSH

Wnt signaling comprises a group of pathways emanating from the extracellular environment through cell-surface receptors into the intracellular milieu. Wnt signaling cascades can be divided into two main branches, the canonical/β-catenin pathway and the non-canonical pathways containing the Wnt/planar cell polarity and Wnt/calcium signaling. Syndecans are type I transmembrane proteoglycans with a long evolutionary history, being expressed in all Bilateria and in almost all cell types. Both Wnt pathways have been extensively studied over the past 30 years and shown to have roles during development and in a multitude of diseases. Although the first evidence for interactions between syndecans and Wnts dates back to 1997, the number of studies connecting these pathways is low, and many open questions remained unanswered. In this review, syndecan's involvement in Wnt signaling pathways as well as some of the pathologies resulting from dysregulation of the components of these pathways are summarized.

• Klíčová slova
• canonical Wnt pathway, disease, heparan sulfate, non-canonical Wnt pathway, syndecan,
• MeSH
• lidé MeSH
• nemoc MeSH
• signální dráha Wnt * MeSH
• syndekany chemie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• syndekany MeSH