Congenital disorders of glycosylation (CDG) represent a wide range of >140 inherited metabolic diseases, continually expanding not only with regards to the number of newly identified causative genes, but also the heterogeneity of the clinical and molecular presentations within each subtype. The deficiency of ATP6AP1, an accessory subunit of the vacuolar H+ -ATPase, is a recently characterised N- and O-glycosylation defect manifesting with immunodeficiency, hepatopathy and cognitive impairment. At the cellular level, the latest studies demonstrate a complex disturbance of metabolomics involving peroxisomal function and lipid homeostasis in the patients. Our study delineates a case of two severely affected siblings with a new hemizygous variant c.221T>C (p.L74P) in ATP6AP1 gene, who both died due to liver failure before reaching 1 year of age. We bring novel pathobiochemical observations including the finding of increased reactive oxygen species in the cultured fibroblasts from the older boy, a striking copper accumulation in his liver, as well as describe the impact of the mutation on the protein in different organs, showing a tissue-specific pattern of ATP6AP1 level and its posttranslational modification.

• Klíčová slova
• ATP6AP1, congenital disorders of glycosylation, copper metabolism, glycosylation, metabolic disorder, oxidative stress,
• MeSH
• fatální výsledek MeSH
• fenotyp MeSH
• kojenec MeSH
• lidé MeSH
• měď metabolismus   MeSH
• metabolomika MeSH
• mutace MeSH
• nemoci jater diagnóza   genetika   metabolismus   MeSH
• oxidační stres genetika   MeSH
• posttranslační úpravy proteinů MeSH
• sourozenci MeSH
• syndromy imunologické nedostatečnosti diagnóza   genetika   metabolismus   MeSH
• vakuolární protonové ATPasy nedostatek   genetika   MeSH
• vrozené poruchy glykosylace diagnóza   genetika   metabolismus   MeSH
• Check Tag
• kojenec MeSH
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ATP6AP1 protein, human MeSH Prohlížeč
• měď MeSH
• vakuolární protonové ATPasy MeSH

To examine reciprocal or unilateral implications between two cell destruction processes, autophagy and apoptosis, in 5-Fluorouracil (5-FU)-treated tumor cells, a combination of chemical inhibitors, RNAi and genetic approaches were used. In contrast to cancer cells harboring obstructed apoptosis, either at the DISC or the mitochondrial level, p53-deficiency generated signs of autophagy deregulation upon chemotherapy. On the other, hand disruption of lysosomal function by chloroquine, caused a profound decrease in apoptotic markers appearing in response to 5-FU. DR5, which is essential for 5-FU-induced apoptosis, accumulated in lysosomes and autophagosomes upon chloroquine treatment. Since neither 3-MA, RNAi of critical autophagy regulators or inhibition of cathepsins reversed apoptosis in a similar manner, it is likely that not autophagy per se but rather correct receptor transport is an important factor for 5-FU cytotoxicity. We found that apoptosis generated by TRAIL, the cognate ligand for DR5, remained unchanged upon chloroquine lysosomal interference, indicating that 5-FU activates the receptor by a discrete mechanism. In support, depletion of membrane cholesterol or hampering cholesterol transport drastically reduced 5-FU cytotoxicity. We conclude that targeting of lysosomes by chloroquine deregulates DR5 trafficking and abrogates 5-FU- but not TRAIL-stimulated cell elimination, hence suggesting a novel mechanism for receptor activation.

• Klíčová slova
• DR5, apoptosis, autophagy, chloroquine, lysosomes,
• MeSH
• apoptóza MeSH
• autofagie * MeSH
• buněčná membrána metabolismus   MeSH
• chlorochin chemie   MeSH
• cholesterol chemie   MeSH
• fagozomy MeSH
• fluoruracil chemie   MeSH
• HCT116 buňky MeSH
• lidé MeSH
• ligandy MeSH
• lyzozomy metabolismus   MeSH
• makrolidy chemie   MeSH
• mitochondrie metabolismus   MeSH
• nádorový supresorový protein p53 metabolismus   MeSH
• protein TRAIL farmakologie   MeSH
• protinádorové antimetabolity farmakologie   MeSH
• RNA interference MeSH
• signální transdukce účinky léků   MeSH
• TRAIL receptory metabolismus   MeSH
• transport proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• bafilomycin A MeSH Prohlížeč
• chlorochin MeSH
• cholesterol MeSH
• fluoruracil MeSH
• ligandy MeSH
• makrolidy MeSH
• nádorový supresorový protein p53 MeSH
• protein TRAIL MeSH
• protinádorové antimetabolity MeSH
• TNFRSF10B protein, human MeSH Prohlížeč
• TP53 protein, human MeSH Prohlížeč
• TRAIL receptory MeSH