Resistance to chemotherapeutics and targeted drugs is one of the main problems in successful cancer therapy. Various mechanisms have been identified to contribute to drug resistance. One of those mechanisms is lysosome-mediated drug resistance. Lysosomes have been shown to trap certain hydrophobic weak base chemotherapeutics, as well as some tyrosine kinase inhibitors, thereby being sequestered away from their intracellular target site. Lysosomal sequestration is in most cases followed by the release of their content from the cell by exocytosis. Lysosomal accumulation of anticancer drugs is caused mainly by ion-trapping, but active transport of certain drugs into lysosomes was also described. Lysosomal low pH, which is necessary for ion-trapping is achieved by the activity of the V-ATPase. This sequestration can be successfully inhibited by lysosomotropic agents and V-ATPase inhibitors in experimental conditions. Clinical trials have been performed only with lysosomotropic drug chloroquine and their results were less successful. The aim of this review is to give an overview of lysosomal sequestration and expression of acidifying enzymes as yet not well known mechanism of cancer cell chemoresistance and about possibilities how to overcome this form of resistance.

• MeSH
• antitumorózní látky farmakologie   MeSH
• chemorezistence * účinky léků   MeSH
• exocytóza MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• lyzozomy účinky léků   enzymologie   MeSH
• nádorové buněčné linie MeSH
• nádory farmakoterapie   enzymologie   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• vakuolární protonové ATPasy antagonisté a inhibitory   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Mucopolysaccharidosis type II (MPSII) is a rare X-linked lysosomal storage disorder caused by mutations in the iduronate-2-sulfatase (IDS) gene (IDS, Xq28). MPSII is characterized by skeletal deformities, hearing loss, airway obstruction, hepatosplenomegaly, cardiac valvular disease, and progressive neurological impairment. At the cellular level, IDS deficiency leads to lysosomal storage of glycosaminoglycans (GAGs), dominated by accumulation of dermatan and heparan sulfates. Human induced pluripotent stem cells (iPSC) represent an alternative system that complements the available MPSII murine model. Herein we report on the reprogramming of peripheral white blood cells from male and female MPSII patients into iPSC using a non-integrating protocol based on the Sendai virus vector system. We differentiated the iPSC lines into IDS deficient and GAG accumulating β-Tubulin III+ neurons, GFAP+ astrocytes, and CNPase+ oligodendrocytes. The lysosomal system in these cells displayed structural abnormalities reminiscent of those previously found in patient tissues and murine IDS deficient neuronal stem cells. Furthermore, quantitative determination of GAGs revealed a moderate increase in GAG levels in IDS deficient neurons and glia. We also tested the effects of recombinant IDS and found that the exogenous enzyme was internalized from the culture media and partially decreased the intracellular GAG levels in iPSC-derived neural cells; however, it failed to completely prevent accumulation of GAGs. In summary, we demonstrate that this human iPSC based model expresses the cellular and biochemical features of MPSII, and thus represents a useful experimental tool for further pathogenesis studies as well as therapy development and testing.

• MeSH
• astrocyty enzymologie   patologie   MeSH
• buněčný rodokmen MeSH
• fenotyp MeSH
• glykosaminoglykany metabolismus   MeSH
• iduronátsulfatasa genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky enzymologie   patologie   MeSH
• kultivované buňky MeSH
• lidé MeSH
• lyzozomy enzymologie   patologie   MeSH
• mukopolysacharidóza II enzymologie   genetika   patologie   MeSH
• nervové kmenové buňky enzymologie   patologie   MeSH
• neurogeneze * MeSH
• neuroglie enzymologie   patologie   MeSH
• neurony enzymologie   patologie   MeSH
• oligodendroglie enzymologie   patologie   MeSH
• prekurzorové buňky oligodendrocytů enzymologie   patologie   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

To ensure successful feeding tick saliva contains a number of inhibitory proteins that interfere with the host immune response and help to create a permissive environment for pathogen transmission. Among the potential targets of the salivary cystatins are two host cysteine proteases, cathepsin S, which is essential for antigen- and invariant chain-processing, and cathepsin C (dipeptidyl peptidase 1, DPP1), which plays a critical role in processing and activation of the granule serine proteases. Here, the effect of salivary cystatin OmC2 fromOrnithodoros moubatawas studied using differentiated MUTZ-3 cells as a model of immature dendritic cells of the host skin. Following internalization, cystatin OmC2 was initially found to inhibit the activity of several cysteine cathepsins, as indicated by the decreased rates of degradation of fluorogenic peptide substrates. To identify targets, affinity chromatography was used to isolate His-tagged cystatin OmC2 together with the bound proteins from MUTZ-3 cells. Cathepsins S and C were identified in these complexes by mass spectrometry and confirmed by immunoblotting. Furthermore, reduced increase in the surface expression of MHC II and CD86, which are associated with the maturation of dendritic cells, was observed. In contrast, human inhibitor cystatin C, which is normally expressed and secreted by dendritic cells, did not affect the expression of CD86. It is proposed that internalization of salivary cystatin OmC2 by the host dendritic cells targets cathepsins S and C, thereby affecting their maturation.

• MeSH
• antigeny CD86 MeSH
• antigeny diferenciační B-lymfocytární MeSH
• buněčné linie MeSH
• cystatiny metabolismus   MeSH
• dendritické buňky imunologie   metabolismus   MeSH
• epoxidové sloučeniny imunologie   metabolismus   MeSH
• geny MHC třídy II imunologie   MeSH
• histokompatibilita - antigeny třídy II MeSH
• kathepsin C metabolismus   MeSH
• kathepsiny chemie   imunologie   metabolismus   MeSH
• klíšťata enzymologie   MeSH
• lidé MeSH
• lyzozomy enzymologie   MeSH
• Ornithodoros enzymologie   MeSH
• rekombinantní proteiny MeSH
• sliny enzymologie   MeSH
• tyrosin analogy a deriváty   imunologie   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nine new compounds having five- and modified six-member carbohydrate core derived from D-lyxose or D-mannose, and non-hydrolysable aglycones (benzylsulfonyl or aryl(alkyl)triazolyl) were synthesised to investigate their ability to inhibit the recombinant Drosophila melanogaster homologs of two human GH38 family enzymes: Golgi mannosidase II (dGMIIb) and lysosomal mannosidase (dLMII). Two compounds were weak selective dGMIIb inhibitors showing IC50 at mM level. Moreover, it was found that another GH38 enzyme, commercial jack bean α-mannosidase, was inhibited by triazole conjugates regardless of the carbohydrate core while the corresponding sulfones were inactive.

• MeSH
• Drosophila melanogaster enzymologie   genetika   MeSH
• inhibitory enzymů chemická syntéza   chemie   farmakologie   MeSH
• lidé MeSH
• lyzozomy enzymologie   MeSH
• mannosa chemie   MeSH
• mannosidasy antagonisté a inhibitory   genetika   MeSH
• molekulární modely MeSH
• proteiny Drosophily antagonisté a inhibitory   genetika   MeSH
• rekombinantní proteiny metabolismus   MeSH
• vazebná místa MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Autophagy-lysosomal pathway is a cellular mechanism ensuring degradation of various macromolecules like proteins or triacylglycerols (TAG). Its disruption is related to many pathological states, including liver steatosis. We compared the effect of short- and long-established steatosis on the intensity of autophagy-lysosomal pathway in rat liver. The experiments were carried out on 3-month old Wistar rats fed standard (SD) or highfat diet for 2 (HF-2) or 10 (HF-10) weeks. HF diet administered animals accumulated an increased amount of TAG in the liver (HF-2→HF-10). Autophagy flux was up-regulated in HF-2 group but nearly inhibited after 10 weeks of HF administration. The expression of autophagy related genes was up-regulated in HF-2 but normal in HF-10. In contrast, total activities of two lysosomal enzymes, lysosomal lipase (LAL) and acid phosphatase, were unaffected in HF-2 but significantly increased in HF-10 groups. mRNA expression of lysosomal enzymes was not affected by the diet. We conclude that in a state of metabolic unbalance (steatosis), autophagy machinery and lysosomal enzymes expression are regulated independently. The accumulation of TAG in the liver is associated with the increase of total LAL activity and protein expression. In contrast, the autophagy response is bi-phasic and after rapid increase it is significantly diminished. This may represent an adaptive mechanism that counteracts the excessive degradation of substrate, i.e. TAG, and eliminate over-production of potentially hazardous lipiddegradation intermediates.

• MeSH
• autofagie MeSH
• časové faktory MeSH
• dieta s vysokým obsahem tuků * MeSH
• dietní tuky farmakologie   MeSH
• játra * metabolismus   MeSH
• krysa rodu rattus MeSH
• lyzozomy enzymologie   metabolismus   MeSH
• messenger RNA metabolismus   MeSH
• potkani Wistar MeSH
• triglyceridy metabolismus   MeSH
• ztučnělá játra * metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

• Klíčová slova
• sval,
• MeSH
• cytokiny metabolismus   MeSH
• forkhead transkripční faktory metabolismus   MeSH
• glukokortikoidy farmakologie   škodlivé účinky   MeSH
• hormony štítné žlázy farmakologie   MeSH
• hypoxie MeSH
• imobilizace škodlivé účinky   MeSH
• insulinu podobný růstový faktor I metabolismus   MeSH
• kachexie etiologie   metabolismus   MeSH
• katecholaminy farmakologie   škodlivé účinky   MeSH
• komplexy ubikvitinligas metabolismus   MeSH
• kosterní svaly enzymologie   metabolismus   patofyziologie   MeSH
• lyzozomy enzymologie   metabolismus   MeSH
• myostatin biosyntéza   MeSH
• oxidační stres MeSH
• proteolýza MeSH
• proteosyntéza MeSH
• receptor IGF typ 1 metabolismus   MeSH
• svalová atrofie etiologie   metabolismus   patofyziologie   MeSH
• svalové proteiny metabolismus   účinky léků   MeSH
• zánět imunologie   metabolismus   MeSH

Ultrastructural and histochemical studies of bioptic and postmortem tissue samples from ten Fabry hemizygotes showed lysosomal storage in adipocytes as a constant feature of the classic phenotype of α-galactosidase (GLA) deficiency. The storage was represented by a crescent-shaped line of storage lysosomes of varying thicknesses restricted to the perinuclear subplasmalemmal area. The ultrastructure of the storage lysosomes was dominated by concentric lipid membranes modified by simultaneous deposition of autofluorescent ceroid. Storage was widely expressed in adipose tissue. The number of storage lysosomes was increased, and the lysosomes were more clustered in adipocytes with less voluminous lipid content. The findings should attract interest to studies of adipose tissue biology in Fabry disease, a topic that has not been studied so far. In terms of cell biology, the observations represent indirect evidence of significant lysosomal turnover of α-galactose lipid conjugates in adipocytes demasked by GLA deficiency. The results extend the thus far limited information on the adipocyte lysosomal system and its participation in lysosomal storage disorders.

• MeSH
• alfa-galaktosidasa genetika   metabolismus   MeSH
• biopsie MeSH
• Fabryho nemoc enzymologie   genetika   patologie   MeSH
• fenotyp MeSH
• genetická predispozice k nemoci MeSH
• glykogen metabolismus   MeSH
• hemizygot MeSH
• lidé MeSH
• lyzozomy enzymologie   ultrastruktura   MeSH
• mutace MeSH
• pitva MeSH
• tukové buňky enzymologie   ultrastruktura   MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

This study was designed to test the role of liver lipases in the degradation of liver triacylglycerols (TAG) and to determine the effect of dietary induced TAG accumulation in the liver on regulation of their lipolysis. Male Wistar rats were administered high-fat or high-sucrose diet for two weeks. Individual lipases (HL; TGH; LAL) were identified according to their different pH optimum. Administration of both diets resulted in liver TAG accumulation (HFD >>> HSD). The only lipase capable to hydrolyse intracellular TAG was LAL. On standard diet, LAL activity towards both endogenous and exogenous substrates was up-regulated in fasting and downregulated in fed state. The intensity of autophagy determined according to the LC3-II/LC3-I protein ratio followed a similar pattern. HFD led to an increase of this ratio, elevation of LAL activity in phagolysosomal fraction and abolishment of fasting/fed-dependent differences. LAL activity significantly correlated with ketogenesis in all groups (r = 0.86; P < 0.01). In the HFD group, we determined the enhanced release of lysosomal enzymes (glucuronidase, LAL) into the cytosol. Dgat-1 expression was up-regulated in HFD- and HSD-fed groups, which indicates increased FFA esterification. We demonstrated that LAL is a dominant enzyme involved in degradation of intracellular TAG in the liver and its translocation into the fraction of active (auto)phagolysosomes is stimulated by diet-induced TAG accumulation. Autophagy is stimulated under the same conditions as LAL and may represent the mechanism ensuring the substrate- -enzyme contact in autophagolysosomes. In fatty liver, destabilization of (auto)phagolysosomes may contribute to their susceptibility to further stress factors.

• MeSH
• autofagie fyziologie   MeSH
• dietní tuky aplikace a dávkování   farmakologie   MeSH
• financování organizované MeSH
• játra enzymologie   metabolismus   účinky léků   MeSH
• konzumní sacharóza aplikace a dávkování   farmakologie   MeSH
• krysa rodu rattus MeSH
• lyzozomy enzymologie   fyziologie   MeSH
• potkani Wistar MeSH
• sterolesterasa metabolismus   MeSH
• triglyceridy metabolismus   MeSH
• ztučnělá játra metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

• MeSH
• infarkt myokardu diagnóza   patologie   prevence a kontrola   MeSH
• ischemické přivykání metody   MeSH
• isoprenalin farmakologie   MeSH
• krysa rodu rattus MeSH
• léčivé rostliny fyziologie   MeSH
• lyzozomy enzymologie   fyziologie   účinky léků   MeSH
• modely nemocí na zvířatech MeSH
• rostlinné extrakty terapeutické užití   MeSH
• Terminalia MeSH
• výsledek terapie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH

Autoři ve své práci demonstrují soubor nemocných vyšetřených magnetickou rezonancí s diagnózou mukopolysacharidózy. Upozorňují na typické projevy onemocnění. I když není kauzální léčba onemocnění známa, zobrazení patologických změn, zvláště komprese míšních struktur nebo obstrukce dýchacích cest (není přítomna u souboru našich nemocných) může pomoci při symptomatické léčbě, která prodlužuje délku a především zlepšuje kvalitu života nemocných.

The purpose of this study was to present the results of MRI examinations in patients with mucopolysaccharidosis. The description of pathological findings, in particular a compression of medullar structures or obstruction of respiratory pathways can help to symptomatic treatment, which prolongs and improves the quality of life.

• MeSH
• dítě MeSH
• lidé MeSH
• lyzozomy enzymologie   fyziologie   patologie   MeSH
• magnetická rezonanční tomografie MeSH
• mladiství MeSH
• mortalita MeSH
• mozek patologie   MeSH
• mukopolysacharidózy etiologie   terapie   MeSH
• příznaky a symptomy MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• kazuistiky MeSH
• přehledy MeSH