Stárnutí lze definovat jako progresivní, ireverzibilní ztrátu vitality a stoupající mortalitu nevyhnutelně přicházejícím s věkem. Jde o stochastický proces, nikoliv program. Biochemická podstata stárnutí spočívá v nemožnosti zabránit nahromadění náhodných chyb v důležitých biomolekulách, tj. v DNA a v bílkovinách. Svou roli v komplikovaném procesu stárnutí hrají reaktivní formy kyslíku, mitochondriální dysfunkce, reaktivní karbonyly, poškození genomové DNA včetně telomer, epigenetické alterace, buněčná senescence a selhání proteostázy. I když všechny tkáně lidského těla stárnou, biologické limity údržby a oprav nejvíce dopadají na buňky, které se nedělí. Jelikož klíčové orgány lidského organismu, mozek, srdce a kosterní sval jsou založeny na postmitotických buňkách, lidská bytost ve svém biologickém těle nesmrtelnosti nikdy dosáhnout nemůže. V rámci svých biologických limitů jsou organismy vybaveny důležitými adaptabilními mechanismy tělesné údržby a oprav, jako je stresem stimulovaná buněčná odolnost vůči stresu (hormeze), autofagie či reakce na poškození DNA. Vhled do těchto mechanismů poskytuje vysvětlení pro příznivé působení faktorů životního stylu, jako je kalorická restrikce a fyzická aktivita, a do budoucna může přinést i léky schopné stárnutí zpomalit.
Aging can be defined as progressive and irreversible loss of vitality and increasing mortality coming inescapably with age. It is a stochastic process, rather than a program. The biochemical essence of aging lies in impossibility to prevent accumulation of random errors in important biomolecules, such as DNA and proteins. In the complicated process of aging, there are roles for reactive oxygen species, mitochondrial dysfunction, reactive carbonyls, and damage to genomic DNA including telomeres, epigenetic alterations, cell senescence, and collapse of proteostasis. Although all tissues of human body age, the biological limits of maintenance and repair affect the non-dividing cells the most. As the key organs of human body, brain, heart, and skeletal muscle, are based on postmitotic cells, a human being in his biological body can never reach immortality. Within the biological limits, organisms are equipped with important adaptable mechanisms for body maintenance and repair, such as stress-induced cellular resistance to stress (hormesis), autophagy and DNA damage response. Insight into these mechanisms provides rationale for benefits of life style interventions, such as caloric restriction and physical exercise, and in future might even bring drugs that could slow aging.
- MeSH
- homeostáze proteinů MeSH
- lidé MeSH
- mitochondrie MeSH
- poškození DNA MeSH
- pyruvaldehyd MeSH
- reaktivní formy kyslíku MeSH
- stárnutí * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
- Klíčová slova
- EMPAGLIFLOZIN,
- MeSH
- benzhydrylové sloučeniny * aplikace a dávkování farmakologie metabolismus MeSH
- diabetické angiopatie farmakoterapie chemicky indukované metabolismus MeSH
- glifloziny aplikace a dávkování farmakologie metabolismus MeSH
- glukosidy * aplikace a dávkování farmakologie metabolismus MeSH
- hypoglykemika * aplikace a dávkování farmakologie metabolismus MeSH
- klinická studie jako téma MeSH
- modely nemocí na zvířatech * MeSH
- potkani Wistar MeSH
- prediabetes * farmakoterapie chemicky indukované metabolismus MeSH
- pyruvaldehyd aplikace a dávkování škodlivé účinky MeSH
- sacharosa škodlivé účinky MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
A side effect of diabetes is formation of glycated proteins and, from them, production of advanced early glycation end products that could determine aberrant immune responses at the systemic level. We investigated a relevant aberrant post-translational modification (PTM) in diabetes based on synthetic peptides modified on the lysine side chain residues with 1-deoxyfructopyranosyl moiety as a possible modification related to glycation. The PTM peptides were used as molecular probes for detection of possible specific autoantibodies developed by diabetic patients. The PDC-E2(167-186) sequence from the pyruvate dehydrogenase complex was selected and tested as a candidate peptide for antibody detection. The structure-based designed type I' β-turn CSF114 peptide was also used as a synthetic scaffold. Twenty-seven consecutive type 1 diabetic patients and 29 healthy controls were recruited for the study. In principle, the 'chemical reverse approach', based on the use of patient sera to screen the synthetic modified peptides, leads to the identification of specific probes able to characterize highly specific autoantibodies as disease biomarkers of autoimmune disorders. Quite surprisingly, both peptides modified with the (1-deoxyfructosyl)-lysine did not lead to significant results. Both IgG and IgM differences between the two populations were not significant. These data can be rationalized considering that i) IgGs in diabetic subjects exhibit a high degree of glycation, leading to decreased functionality; ii) IgGs in diabetic subjects exhibit a privileged response vs proteins containing advanced glycation products (e.g., methylglyoxal, glyoxal, glucosone, hydroimidazolone, dihydroxyimidazolidine) and only a minor one with respect to (1-deoxyfructosyl)-lysine.
- MeSH
- diabetes mellitus 1. typu metabolismus MeSH
- glykosylace MeSH
- glyoxal metabolismus MeSH
- imidazoly metabolismus MeSH
- imunoanalýza MeSH
- ketosy metabolismus MeSH
- lidé MeSH
- lysin chemie metabolismus MeSH
- peptidy chemie metabolismus MeSH
- posttranslační úpravy proteinů MeSH
- produkty pokročilé glykace metabolismus MeSH
- pyruvaldehyd metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
The great research interest in the quantification of reactive carbonyl compounds (RCCs), such as methylglyoxal (MGO) in biological and environmental samples, is reflected by the fact that several publications have described specific strategies to perform this task. Thus, many reagents have also been reported for the derivatization of RCCs to effectively detect and quantify the resulting compounds using sensitive techniques such as liquid chromatography coupled with mass spectrometry (LC-MS). However, the choice of the derivatization protocol is not always clear, and a comparative evaluation is not feasible because detection limits from separate reports and determined with different instruments are hardly comparable. Consequently, for a systematic comparison, we tested 21 agents in one experimental setup for derivatization of RCCs prior to LC-MS analysis. This consisted of seven commonly employed reagents and 14 similar reagents, three of which were designed and synthesized by us. All reagents were probed for analytical responsiveness of the derivatives and stability of the reaction mixtures. The results showed that derivatives of 4-methoxyphenylenediamine and 3-methoxyphenylhydrazine-reported here for the first time for derivatization of RCCs-provided a particularly high responsiveness with ESI-MS detection. We applied the protocol to investigate MGO contamination of laboratory water and show successful quantification in a lipoxidation experiment. In summary, our results provide valuable information for scientists in establishing accurate analysis of RCCs.
Reactive dicarbonyls stimulate production of advanced glycation endproducts, increase oxidative stress and inflammation and contribute to the development of vascular complications. We measured concentrations of dicarbonyls - methylglyoxal (MG), glyoxal (GL) and 3-deoxyglucosone (3-DG) - in the heart and kidney of a model of metabolic syndrome - hereditary hypertriglyceridemic rats (HHTg) and explored its modulation by metformin. Adult HHTg rats were fed a standard diet with or without metformin (300 mg/kg b.w.) and dicarbonyl levels and metabolic parameters were measured. HHTg rats had markedly elevated serum levels of triacylglycerols (p<0.001), FFA (p<0.01) and hepatic triacylglycerols (p<0.001) along with increased concentrations of reactive dicarbonyls in myocardium (MG: p<0.001; GL: p<0.01; 3-DG: p<0.01) and kidney cortex (MG: p<0.01). Metformin treatment significantly reduced reactive dicarbonyls in the myocardium (MG: p<0.05, GL: p<0.05, 3-DG: p<0.01) along with increase of myocardial concentrations of reduced glutathione (p<0.01) and glyoxalase 1 mRNA expression (p<0.05). Metformin did not have any significant effect on dicarbonyls, glutathione or on glyoxalase 1 expression in kidney cortex. Chronically elevated hypertriglyceridemia was associated with increased levels of dicarbonyls in heart and kidney. Beneficial effects of metformin on reactive dicarbonyls and glyoxalase in the heart could contribute to its cardioprotective effects.
- MeSH
- deoxyglukosa analogy a deriváty metabolismus MeSH
- dieta MeSH
- fyziologický stres MeSH
- glutathion metabolismus MeSH
- glyoxal metabolismus MeSH
- hypertriglyceridemie farmakoterapie genetika patofyziologie MeSH
- hypoglykemika terapeutické užití MeSH
- krysa rodu rattus MeSH
- laktoylglutathionlyasa metabolismus MeSH
- metformin terapeutické užití MeSH
- myokard metabolismus MeSH
- potkani Wistar MeSH
- pyruvaldehyd metabolismus MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Methylglyoxal production is increased in diabetes. Methylglyoxal is efficiently detoxified by enzyme glyoxalase 1 (GLO1). The aim was to study the effect of diabetic and CKD milieu on (a) GLO1 gene expression in peripheral blood mononuclear cells; (b) GLO1 protein levels in whole blood; and (c) GLO1 activity in RBCs in vivo in diabetic vs. non-diabetic subjects with normal or slightly reduced vs. considerably reduced renal function (CKD1-2 vs. CKD3-4). A total of 83 subjects were included in the study. Gene expression was measured using real-time PCR, and protein levels were quantified using Western blotting. Erythrocyte GLO1 activity was measured spectrophotometrically. GLO1 gene expression was significantly higher in subjects with CKD1-2 compared to CKD3-4. GLO1 protein level was lower in diabetics than in non-diabetics. GLO1 activity in RBCs differed between the four groups being significantly higher in diabetics with CKD1-2 vs. healthy subjects and vs. nondiabeticsfig with CKD3-4. GLO1 activity was significantly higher in diabetics compared to nondiabetics. In conclusion, both diabetes and CKD affects the glyoxalase system. It appears that CKD in advanced stages has prevailing and suppressive effects compared to hyperglycaemia. CKD decreases GLO1 gene expression and protein levels (together with diabetes) without concomitant changes of GLO1 activity.
- MeSH
- chronická renální insuficience krev patologie MeSH
- diabetes mellitus krev patologie MeSH
- diabetické nefropatie krev patologie MeSH
- laktoylglutathionlyasa krev MeSH
- lidé středního věku MeSH
- lidé MeSH
- pyruvaldehyd krev MeSH
- senioři MeSH
- studie případů a kontrol MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson's disease (PD), are increasing in prevalence. Currently, there are no effective and specific treatments for these disorders. Recently, positive effects of the orexigenic hormone ghrelin on memory and learning were demonstrated in mouse models of AD and PD. In this study, we tested the potential neuroprotective properties of a stable and long-lasting ghrelin analog, Dpr(3)ghrelin (Dpr(3)ghr), in SH-SY5Y neuroblastoma cells stressed with 1.2 mM methylglyoxal (MG), a toxic endogenous by-product of glycolysis, and we examined the impact of Dpr(3)ghr on apoptosis. Pre-treatment with both 10(-5) and 10(-7) M Dpr(3)ghr resulted in increased viability in SH-SY5Y cells (determined by MTT staining), as well as reduced cytotoxicity of MG in these cells (determined by LDH assay). Dpr(3)ghr increased viability by altering pro-apoptotic and viability markers: Bax was decreased, Bcl-2 was increased, and the Bax/Bcl-2 ratio was attenuated. The ghrelin receptor GHS-R1 and Dpr(3)ghr-induced activation of PBK/Akt were immuno-detected in SH-SY5Y cells to demonstrate the presence of GHS-R1 and GHS-R1 activation, respectively. We demonstrated that Dpr(3)ghr protected SH-SY5Y cells against MG-induced neurotoxicity and apoptosis. Our data suggest that stable ghrelin analogs may be candidates for the effective treatment of neurodegenerative disorders.
- MeSH
- apoptóza účinky léků MeSH
- ghrelin analogy a deriváty farmakologie MeSH
- glykolýza účinky léků MeSH
- L-laktátdehydrogenasa metabolismus MeSH
- lidé MeSH
- MAP kinasový signální systém účinky léků MeSH
- membránový potenciál mitochondrií účinky léků MeSH
- nádorové buněčné linie MeSH
- neuroprotektivní látky farmakologie MeSH
- neurotoxické syndromy prevence a kontrola MeSH
- proteiny regulující apoptózu biosyntéza genetika MeSH
- pyruvaldehyd toxicita MeSH
- receptory ghrelinu biosyntéza MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
An electrophoretic apparatus with a flow-gating interface has been developed, enabling hydrodynamic sequence injection of the sample into the separation capillary from the liquid flow by underpressure generated in the outlet electrophoretic vessel. The properties of the apparatus were tested on an artificial sample of an equimolar mixture of 100μM potassium and sodium ions and arginine. The repeatability of the injection of the tested ions expressed as RSD (in%) for the peak area, peak height and migration time was in the range 0.76-2.08, 0.18-0.68 and 0.28-0.48, respectively. Under optimum conditions, the apparatus was used for sequence monitoring of the reaction between the antidiabetic drug phenyl biguanide and the glycation agent methyl glyoxal. The reaction solution was continuously sampled by a microdialysis probe from a thermostated external vessel using a syringe pump at a flow rate of 3μLmin(-1) and was injected into a separation capillary at certain time intervals. The electrophoretic separation progressed in a capillary with an internal diameter of 50μm with a length of 11.5cm and was monitored using a contactless conductivity detector.
- MeSH
- diabetes mellitus metabolismus MeSH
- dyslipidemie diagnóza etiologie metabolismus MeSH
- hypertriglyceridemie etiologie klasifikace MeSH
- inzulin aplikace a dávkování metabolismus MeSH
- krysa rodu rattus MeSH
- metabolický syndrom * metabolismus MeSH
- modely nemocí na zvířatech MeSH
- produkty pokročilé glykace metabolismus škodlivé účinky MeSH
- pyruvaldehyd * izolace a purifikace metabolismus toxicita MeSH
- statistika jako téma MeSH
- tuková tkáň * chemie metabolismus účinky léků MeSH
- zvířata MeSH
- Check Tag
- krysa rodu rattus MeSH
- mužské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- MeSH
- albuminurie diagnóza etiologie MeSH
- diabetické nefropatie * diagnóza etiologie metabolismus MeSH
- experimenty na zvířatech * MeSH
- glutathion izolace a purifikace metabolismus MeSH
- metabolomika metody MeSH
- oxidační stres imunologie účinky léků MeSH
- polymerázová řetězová reakce s reverzní transkripcí metody využití MeSH
- potkani inbrední SHR MeSH
- produkty pokročilé glykace izolace a purifikace metabolismus MeSH
- proteomika metody MeSH
- pyruvaldehyd * metabolismus škodlivé účinky terapeutické užití MeSH
- stanovení celkové genové exprese metody využití MeSH
- vysokoúčinná kapalinová chromatografie metody využití MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
