Background: Pheochromocytoma and paraganglioma (PHEO/PGL) are rare neuroendocrine tumors which may cause potentially life-threatening complications, with about a third of cases found to harbor specific gene mutations. Thus, early diagnosis, treatment, and meticulous monitoring are of utmost importance. Because of low incidence of succinate dehydrogenase complex subunit A (SDHA)-related metastatic PHEO/PGL, currently there exists insufficient clinical information, especially with regards to its diagnostic and treatment characteristics. Methods: Ten patients with SDHA-related metastatic PHEO/PGL were followed-up prospectively and/or retrospectively between January 2010-July 2018. They underwent biochemical tests (n = 10), 123I-MIBG (n = 9) scintigraphy, and multiple whole-body positron emission tomography/computed tomography (PET/CT) scans with 68Ga-DOTATATE (n = 10), 18F-FDG (n = 10), and 18F-FDOPA (n = 6). Results: Our findings suggest that these tumors can occur early and at extra-adrenal locations, behave aggressively, and have a tendency to develop metastatic disease within a short period of time. None of our patients had a family history of PHEO/PGL, making them appear sporadic. Nine out of 10 patients showed abnormal PHEO/PGL-specific biochemical markers with predominantly noradrenergic and/or dopaminergic phenotype, suggesting their utility in diagnosing and monitoring the disease. Per patient detection rates of 68Ga-DOTATATE (n = 10/10), 18F-FDG (n = 10/10), 18F-FDOPA (n = 5/6) PET/CT, and 123I-MIBG (n = 7/9) scintigraphy were 100, 100, 83.33, and 77.77%, respectively. Five out of 7 123I-MIBG positive patients had minimal 123I-MIBG avidity or detected very few lesions compared to widespread metastatic disease on 18F-FDG PET/CT, implying that diagnosis and treatment with 123/131I-MIBG is not a good option. 68Ga-DOTATATE PET/CT was found to be superior or equal to 18F-FDG PET/CT in 7 out of 10 patients and hence, is recommended for evaluation and follow-up of these patients. All 7 out of 7 patients who received conventional therapies (chemotherapy, somatostatin analog therapy, radiation therapy, 131I-MIBG, peptide receptor radionuclide therapy) in addition to surgery showed disease progression. Conclusion: In our cohort of patients, SDHA-related metastatic PHEO/PGL followed a disease-course similar to that of SDHB-related metastatic PHEO/PGL, showing highly aggressive behavior, similar imaging and biochemical phenotypes, and suboptimal response to conventional therapies. Therefore, we recommend careful surveillance of the affected patients and a search for effective therapies.

• Publikační typ
• časopisecké články MeSH

Mitochondrial complex II or succinate dehydrogenase (SDH) is at the crossroads of oxidative phosphorylation and the tricarboxylic acid cycle. It has been shown that Sdh5 (SDHAF2/SDH5 in mammals) is required for flavination of the subunit Sdh1 (SDHA in human cells) in yeast. Here we demonstrate that in human breast cancer cells, SDHAF2/SDH5 is dispensable for SDHA flavination. In contrast to yeast, CRISPR-Cas9 nickase-mediated SDHAF2 KO breast cancer cells feature flavinated SDHA and retain fully assembled and functional complex II, as well as normal mitochondrial respiration. Our data show that SDHA flavination is independent of SDHAF2 in breast cancer cells, employing an alternative mechanism.

• MeSH
• flaviny MeSH
• genový knockdown MeSH
• lidé MeSH
• mitochondriální proteiny genetika   metabolismus   MeSH
• mitochondrie genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• nádory prsu genetika   metabolismus   MeSH
• posttranslační úpravy proteinů * MeSH
• respirační komplex II genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Complex II of the respiratory chain (RC) recently emerged as a prominent regulator of cell death. In both cancer cells as well as neurodegenerative diseases, mutations in subunits have been found along with other genetic alterations indirectly affecting this complex. Anticancer compounds were developed that target complex II and cause cell death in a tumor-specific way. Our mechanistic understanding of how complex II is activated for cell death induction has recently been made clearer in recent studies, the results of which are covered in this review. This protein assembly is specifically activated for cell death via the dissociation of its SDHA and SDHB subunits from the membrane-anchoring proteins through pH change or mitochondrial Ca(2+) influx. The SDH activity contained in the SDHA/SDHB subcomplex remains intact and then generates, in an uncontrolled fashion, excessive amounts of reactive oxygen species (ROS) for cell death. Future studies on this mitochondrial complex will further elucidate it as a target for cancer treatments and reveal its role as a nexus for many diverse stimuli in cell death signaling.

• MeSH
• buněčná smrt fyziologie   MeSH
• elektronový transportní řetězec fyziologie   MeSH
• energetický metabolismus fyziologie   MeSH
• mitochondrie fyziologie   MeSH
• regulace genové exprese fyziologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Early neonatal adaptation to extrauterine life is i.a. dependent on effective mitochondrial biogenesis during foetal development. Understanding of mitochondrial biogenesis is limited, because only scarce data are available from prenatal studies including RNA analyses in human foetal tissues. Aims of the study were focused on the factors affecting RNA quality in human placental tissue (HPT) including temperature, time period before HPT freezing and the Apgar score. In addition, optimal reference genes for mRNA quantification by real-time PCR in HPT were studied. Samples of HPT were obtained after the birth of 20 term neonates. Seven HPT were used for the time-course study of RNA degradation in two different temperatures (0 °C and 24 °C). Various instruments NanoDrop (NanoDrop Technologies), Experion (Bio-Rad Laboratories), Agilent 2100 Bioanalyzer (Agilent Technologies) were used for analysis of RNA integrity, purity and yield. Identification of suitable reference genes was achieved by analysing six candidate genes (ATP5O, SDHA, TBP, HPRT, PMBS, ATP6) for their expression stability (GeNorm application). The results showed that the HPT samples for RNA analyses must be frozen immediately after birth in –80 °C or stored at 0 °C maximally for 1 hour. The reference genes ATP50 and SDHA were the most stable for mRNA quantification in HPT. Human placenta represents easily obtainable source of foetal tissue for studies concerning mitochondrial biogenesis. We demonstrated that the critical limit for optimal storage and handling of HPT are the temperature and the time period before freezing of the samples.

• MeSH
• Apgar skóre MeSH
• financování organizované MeSH
• lidé MeSH
• novorozenec MeSH
• placenta chemie   MeSH
• plod MeSH
• polymerázová řetězová reakce MeSH
• RNA analýza   MeSH
• těhotenství MeSH
• teplota MeSH
• uchovávání tkání MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• novorozenec MeSH
• těhotenství MeSH
• ženské pohlaví MeSH

Complex II (CII) activity controls phenomena that require crosstalk between metabolism and signaling, including neurodegeneration, cancer metabolism, immune activation, and ischemia-reperfusion injury. CII activity can be regulated at the level of assembly, a process that leverages metastable assembly intermediates. The nature of these intermediates and how CII subunits transfer between metastable complexes remains unclear. In this work, we identify metastable species containing the SDHA subunit and its assembly factors, and we assign a preferred temporal sequence of appearance of these species during CII assembly. Structures of two species show that the assembly factors undergo disordered-to-ordered transitions without the appearance of significant secondary structure. The findings identify that intrinsically disordered regions are critical in regulating CII assembly, an observation that has implications for the control of assembly in other biomolecular complexes.

• MeSH
• katalytická doména * MeSH
• sekundární struktura proteinů MeSH
• Publikační typ
• časopisecké články MeSH

Cell growth and survival depend on a delicate balance between energy production and synthesis of metabolites. Here, we provide evidence that an alternative mitochondrial complex II (CII) assembly, designated as CIIlow, serves as a checkpoint for metabolite biosynthesis under bioenergetic stress, with cells suppressing their energy utilization by modulating DNA synthesis and cell cycle progression. Depletion of CIIlow leads to an imbalance in energy utilization and metabolite synthesis, as evidenced by recovery of the de novo pyrimidine pathway and unlocking cell cycle arrest from the S-phase. In vitro experiments are further corroborated by analysis of paraganglioma tissues from patients with sporadic, SDHA and SDHB mutations. These findings suggest that CIIlow is a core complex inside mitochondria that provides homeostatic control of cellular metabolism depending on the availability of energy.

• MeSH
• biosyntetické dráhy fyziologie   MeSH
• energetický metabolismus fyziologie   MeSH
• fyziologický stres * MeSH
• genový knockout MeSH
• HEK293 buňky MeSH
• kontrolní body fáze S buněčného cyklu fyziologie   MeSH
• lidé MeSH
• malá interferující RNA metabolismus   MeSH
• mitochondrie metabolismus   MeSH
• mutace MeSH
• myši inbrední BALB C MeSH
• myši nahé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• paragangliom genetika   patologie   MeSH
• respirační komplex II genetika   metabolismus   MeSH
• sukcinátdehydrogenasa genetika   metabolismus   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Adaptation to chronic hypoxia renders the heart more tolerant to ischemia/reperfusion injury. To evaluate changes in gene expression after adaptation to chronic hypoxia by RT-qPCR, it is essential to select suitable reference genes. In a chronically hypoxic rat model, no specific reference genes have been identified in the myocardium. This study aimed to select the best reference genes in the left (LV) and right (RV) ventricles of chronically hypoxic and normoxic rats. Sprague-Dawley rats were adapted to continuous normobaric hypoxia (CNH; 12% O2 or 10% O2) for 3 weeks. The expression levels of candidate genes were assessed by RT-qPCR. The stability of genes was evaluated by NormFinder, geNorm and BestKeeper algorithms. The best five reference genes in the LV were Top1, Nupl2, Rplp1, Ywhaz, Hprt1 for the milder CNH and Top1, Ywhaz, Sdha, Nupl2, Tomm22 for the stronger CNH. In the RV, the top five genes were Hprt1, Nupl2, Gapdh, Top1, Rplp1 for the milder CNH and Tomm22, Gapdh, Hprt1, Nupl2, Top1 for the stronger CNH. This study provides validation of reference genes in LV and RV of CNH rats and shows that suitable reference genes differ in the two ventricles and depend on experimental protocol.

• MeSH
• chronická nemoc MeSH
• hypoxie genetika   MeSH
• myokard metabolismus   patologie   MeSH
• potkani Sprague-Dawley MeSH
• referenční standardy MeSH
• regulace genové exprese * MeSH
• srdeční komory metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Succinate dehydrogenase (SDH), formed by four subunits SDHA, SDHB, SDHC, SDHD, and an assembly factor SDHAF2, functions as a key respiratory enzyme. Biallelic inactivation of genes encoding any of the components, almost always in the presence of a germline mutation, causes loss of function of the entire enzyme complex (so-called SDH deficiency) and subsequent development of SDH-deficient neoplasms which include pheochromocytoma/paraganglioma, gastrointestinal stromal tumor, and renal cell carcinoma (RCC). These tumors may occur in the same patient or kindred. SDH-deficient RCC shows distinctive morphological features with vacuolated eosinophilic cytoplasm due to distinctive cytoplasmatic inclusions containing flocculent material. The diagnosis is confirmed by loss of SDHB on immunohistochemistry with positive internal control. The majority of tumors occur in the setting of germline mutations in one of the SDH genes, most commonly SDHB. The prognosis is excellent for low-grade tumors but worse for high-grade tumors with high-grade nuclei, sarcomatoid change, or coagulative necrosis. Awareness of the morphological features and low-threshold for applying SDHB immunohistochemistry help identify patients with SDH-deficient RCC and hereditary SDH-deficient tumor syndromes. In this review we summarize recent development on the clinical and genetic features, diagnostic approach, and pitfalls of SDH-deficient syndrome, focusing on SDH-deficient renal cell carcinomas.

• MeSH
• dědičné nádorové syndromy * genetika   MeSH
• karcinom z renálních buněk * genetika   MeSH
• lidé MeSH
• nádory ledvin * genetika   patologie   MeSH
• sarkom * MeSH
• sukcinátdehydrogenasa genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

V období let 1990-2000 došlo v ČR k prodloužení střední délky života mužské populace nově narozených o 4,1 roku, ženské populace 2,9 roku.K prodloužení SDŽ došlo i ve vyšších věkových skupinách. Přes tento pozitivní vývoj je SDŽ v ČR významně nižší v porovnání s průměrnými hodnotami populací zemí EU (rozdíl činí více než 4 roky u SDŽ mužů a 3 roky u SDŽ žen). Pozitivních změn v růstu SDŽ v ČR bylo dosaženo spíše rozšířením technologických možností poskytovatelů péče a zlepšením ekologických podmínek, než zlepšením vztahu obyvatel k vlastnímu zdraví. Marginální náklady zdravotnického systému související s prodloužením života o 1 rok se pohybují u populace nově narozených kolem 13 000 Kč, je to podstatně méně než v zemích EU. Možnosti dalšího prodlužování SDŽ obyvatelstva ČR jsou především ve snižování úmrtnosti na nemoci oběhového systému, zhoubné nádory a vnější příčiny smrti. Pro rok 2003 se dá očekávat další zlepšení ukazatelů SDŽ; pro muže v intervalu 73-75 let, pro ženy 80-83 let.

During the period between 1990 and 2000 the mean life span in the Czech Republic increased by 4.1 in the new born male population and by 2.9 years in the female population. Prolongation of the mean life span occurred also in the older age groups. Despite this positive development the mean life span in the Czech Republic is significantly shorter as compared with mean values of theEUcountries (the difference is more than 4 years in alems and 3 years in females).Positive changes of the increase in the mean life span were achieved in the CR rather by extension of technological conditions than by an improved attitude of the population to their own health. The marginal costs of the healthcare system associated with prolongation of life by one year are in the population of the new born approximately 13 000 crowns which is substantially less than in the EU countries. Possibilities of further prolongation of the life span of the population in the CR involve in particular reduction of the mortality rate from cardiovascular diseases, malignant tumours and external causes of death. For 2003 further improvement of indicators of the mean life span may be foreseen: for men in the age bracket from 73-75 years, for women from 80 to 83 years.

• MeSH
• dítě MeSH
• dospělí MeSH
• Evropská unie MeSH
• finanční podpora výzkumu jako téma MeSH
• lidé středního věku MeSH
• lidé MeSH
• naděje dožití MeSH
• populace MeSH
• postoj ke zdraví MeSH
• příčina smrti MeSH
• senioři MeSH
• ukazatele zdravotního stavu MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• přehledy MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH

Mitochondria play a pivotal role in apoptosis: permeabilization of the outer mitochondrial membrane and the release of pro-apoptotic proteins from the intermembrane space of mitochondria are regarded as the key event in apoptosis induction. Here we demonstrate how non-toxic doses of the mitochondrial Complex II inhibitor thenoyltrifluoroacetone (TTFA), which specifically inhibits the ubiquinone-binding site of succinate dehydrogenase (SDH), synergistically stimulated cell death, induced by harmless doses of cisplatin in a panel of chemoresistant neuroblastoma cell lines. Apoptotic cell death was confirmed by cytochrome c release from the mitochondria, cleavage of poly ADP-ribose polymerase, processing of caspase-3, which is an important executive enzyme in apoptosis, and caspase-3-like activity. Methyl malonate, an inhibitor of the SDHA subunit partially reversed apoptosis stimulated by TTFA in SK-N-BE(2) neuroblastoma cells (NB), indicating that sensitization requires oxidation of succinate. In contrast, in IMR-32 NB cells, the same concentrations of TTFA markedly suppressed cisplatin-induced apoptosis. Comparison of oxygen consumption in cisplatin-resistant SK-N-BE(2) and cisplatin-sensitive IMR-32 cells clearly demonstrated impaired Complex II activity in IMR-32 cells. We also found that in SK-N-BE(2) cells co-treatment with cisplatin and TTFA markedly stimulated formation of reactive oxygen species (ROS), whereas in IMR cells, cisplatin-mediated ROS production was attenuated by TTFA, which explains apoptosis suppression in these cells. Thus, functionally active SDH is a prerequisite for the ROS-mediated sensitization to treatment by TTFA.

• MeSH
• antitumorózní látky farmakologie   MeSH
• apoptóza účinky léků   MeSH
• chemorezistence MeSH
• cílená molekulární terapie * MeSH
• cisplatina farmakologie   MeSH
• kyselina jantarová metabolismus   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• mitochondrie účinky léků   enzymologie   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny antagonisté a inhibitory   MeSH
• neuroblastom patologie   MeSH
• oxidace-redukce MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• respirační komplex II antagonisté a inhibitory   MeSH
• spotřeba kyslíku účinky léků   MeSH
• superoxidy metabolismus   MeSH
• synergismus léků MeSH
• thenoyltrifluoraceton farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH