In previous research, we revealed that murine leukemia cells L1210 with induced expression of P-glycoprotein (P-gp, a membrane drug transporter, product of the Abcb1 gene) are better able to withstand endoplasmic reticulum (ER) stress (ERS) than their P-gp negative counterparts. This was associated with increased GRP78/BiP expression and modulation of the expression of several other proteins active in the cellular response to ERS (like CHOP, spliced XBP1, 50-kDa ATF6 protein fragment and others) in P-gp positive cells. Wolframin is an ER transmembrane protein, product of the WFS1 gene whose mutations are associated with Wolfram syndrome. However, this protein is frequently overexpressed in cells undergoing ERS and its expression may accompany changes in the above ERS markers. Therefore, our aim in this work was to investigate wolframin expression in P-gp-negative and P-gp-positive murine leukemia L1210 cells in relation to ERS related proteins in normal or ERS condition. We induced ERS in cells either by blocking N-glycosylation in the ER with tunicamycin or by blocking ER Ca2+-ATPase activity with thapsigargin, as known ER stressors. The results of this paper demonstrated increased wolframin expression in P-gp positive cells compared to P-gp negative cells. Immunoprecipitation experiments revealed the formation of complexes between wolframin and ERS related proteins (PERK, ATF6 and GRP78/BiP), the amount of which varied depending on the presence of the above ER stressors.
- Publikační typ
- časopisecké články MeSH
Ribozomy jsou buněčné struktury zodpovědné za syntézu proteinů. Utvářejí se během složitého procesu, který se nazývá biogeneze ribozomů. Vrozené ribozomopatie jsou heterogenní skupinou onemocnění, jejichž příčinou jsou genetické abnormality způsobující narušení biogeneze a funkce ribozomů. Mutovány mohou být geny ribozomálních proteinů i dalších faktorů podílejících se na ribozomální biogenezi. Charakteristickým znakem vrozených ribozomopatií jsou tkáňově specifická poškození a zvýšené riziko rozvoje nádorových onemocnění. Nedávný výzkum navíc odhalil, že klinicky významné jsou i somatické mutace v genech pro ribozomální proteiny, jelikož se podílejí na procesu nádorové transformace. V tomto souhrnném článku je popsáno patofyziologické působení ribozomálních defektů na buněčné a molekulární úrovni i možné mechanizmy podporující onkogenezi. Článek dále pojednává o léčbě ribozomopatií a představuje nové terapeutické možnosti.
Ribosomes are cellular structures responsible for protein synthesis. They are formed during a complex process called ribosome biogenesis. Congenital ribosomopathies are a heterogeneous group of diseases caused by genetic abnormalities that disrupt ribosome biogenesis and function with causative mutations affecting genes encoding for ribosomal proteins or other factors involved in ribosome biogenesis. A hallmark of congenital ribosomopathies is tissue-specific damage and an increased risk of cancer development. In addition, recent research has revealed that somatic mutations in genes for ribosomal proteins are also clinically relevant as they are involved in the process of malignant transformation. In this review article, we describe the pathophysiological effects of ribosome dysfunction at the cellular and molecular level, as well as possible mechanisms promoting oncogenesis. The article also discusses current treatment of ribosomopathies and presents new therapeutic options.
- Klíčová slova
- ribozomopatie,
- MeSH
- biogeneze organel MeSH
- Diamondova-Blackfanova anemie genetika patofyziologie patologie terapie MeSH
- genetické nemoci vrozené farmakoterapie genetika klasifikace patofyziologie terapie MeSH
- krevní nemoci * farmakoterapie genetika klasifikace patofyziologie terapie MeSH
- lidé MeSH
- mutace MeSH
- nádorový supresorový protein p53 MeSH
- ribozomy * patologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- přehledy MeSH
Congenital erythrocytoses represent a heterogenous group of rare defects of erythropoiesis characterized by elevated erythrocyte mass. We performed molecular-genetic analysis of 21 Czech patients with congenital erythrocytosis and assessed the mutual link between chronic erythrocyte overproduction and iron homoeostasis. Causative mutations in erythropoietin receptor (EPOR), hypoxia-inducible factor 2 alpha (HIF2A) or Von Hippel-Lindau (VHL) genes were detected in nine patients, including a novel p.A421Cfs*4 EPOR and a homozygous intronic c.340+770T>C VHL mutation. The association and possible cooperation of five identified missense germline EPOR or Janus kinase 2 (JAK2) variants with other genetic/non-genetic factors in erythrocytosis manifestation may involve variants of Piezo-type mechanosensitive ion channel component 1 (PIEZO1) or Ten-eleven translocation 2 (TET2), but this requires further research. In two families, hepcidin levels appeared to prevent or promote phenotypic expression of the disease. No major contribution of heterozygous haemochromatosis gene (HFE) mutations to the erythrocytic phenotype or hepcidin levels was observed in our cohort. VHL- and HIF2A-mutant erythrocytosis showed increased erythroferrone and suppressed hepcidin, whereas no overproduction of erythroferrone was detected in other patients regardless of molecular defect, age or therapy. Understanding the interplay between iron metabolism and erythropoiesis in different subgroups of congenital erythrocytosis may improve current treatment options.
- MeSH
- hepcidiny genetika MeSH
- iontové kanály genetika MeSH
- kyslík metabolismus MeSH
- lidé MeSH
- mutace MeSH
- polycytemie * genetika MeSH
- receptory erythropoetinu genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
