Diabetic foot ulcer (DFU) is a serious complication of diabetes and hyperbaric oxygen therapy (HBOT) is also considered in comprehensive treatment. The evidence supporting the use of HBOT in DFU treatment is controversial. The aim of this work was to introduce a DFU model in ZDF rat by creating a wound on the back of an animal and to investigate the effect of HBOT on the defect by macroscopic evaluation, quantitative histological evaluation of collagen (types I and III), evaluation of angiogenesis and determination of interleukin 6 (IL6) levels in the plasma. The study included 10 rats in the control group (CONT) and 10 in the HBOT group, who underwent HBOT in standard clinical regimen. Histological evaluation was performed on the 18th day after induction of defect. The results show that HBOT did not affect the macroscopic size of the defect nor IL6 plasma levels. A volume fraction of type I collagen was slightly increased by HBOT without reaching statistical significance (1.35±0.49 and 1.94±0.67 %, CONT and HBOT, respectively). In contrast, the collagen type III volume fraction was ~120 % higher in HBOT wounds (1.41±0.81 %) than in CONT ones (0.63±0.37 %; p=0.046). In addition, the ratio of the volume fraction of both collagens in the wound ((I+III)w) to the volume fraction of both collagens in the adjacent healthy skin ((I+III)h) was ~65 % higher in rats subjected to HBOT (8.9±3.07 vs. 5.38±1.86 %, HBOT and CONT, respectively; p=0.028). Vessels density (number per 1 mm2 ) was found to be higher in CONT vs. HBOT (206.5±41.8 and 124±28.2, respectively, p<0.001). Our study suggests that HBOT promotes collagen III formation and decreases the number of newly formed vessels at the early phases of healing., Jiří Růžička, Martina Grajciarová, Lucie Vištejnová, Pavel Klein, Filip Tichánek, Zbyněk Tonar, Jiří Dejmek, Jiří Beneš, Lukáš Bolek, Robert Bajgar, Jitka Kuncová., and Obsahuje bibliografii
Chronic wound is a serious medical issue due to its high prevalence and complications; hyperbaric oxygen therapy (HBOT) is also considered in comprehensive treatment. Clinical trials, including large meta-analyses bring inconsistent results about HBOT efficacy. This review is summarizing the possible effect of HBOT on the healing of chronic wound models at the cellular level. HBOT undoubtedly escalates the production of reactive oxygen and nitrogen radicals (ROS and RNS), which underlie both the therapeutic and toxic effects of HBOT on certain tissues. HBOT paradoxically elevates the concentration of Hypoxia inducible factor (HIF) 1 by diverting the HIF-1 degradation to pathways that are independent of the oxygen concentration. Elevated HIF-1 stimulates the production of different growth factors, boosting the healing process. HBOT supports synthesis of Heat shock proteins (HSP), which are serving as chaperones of HIF-1. HBOT has antimicrobial effect, increases the effectiveness of some antibiotics, stimulates fibroblasts growth, collagen synthesis and suppresses the activity of proteolytic enzymes like matrix metalloproteinases. All effects of HBOT were investigated on cell cultures and animal models, the limitation of their translation is discussed at the end of this review
Mitochondria are considered central regulator of the aging process; however, majority of studies dealing with the impact of age on mitochondrial oxygen consumption focused on skeletal muscle concluding (although not uniformly) a general declining trend with advancing age. In addition, gender related differences in mitochondrial respiration have not been satisfactorily described yet. The aim of the present study was to evaluate mitochondrial oxygen consumption in various organs of aging male and female Fischer 344 rats at the ages of 6, 12 and 24 months. Mitochondrial respiration of homogenized (skeletal muscle, left and right heart ventricle, hippocampus, cerebellum, kidney cortex), gently mechanically permeabilized (liver) tissue or intact cells (platelets) was determined using high-resolution respirometry (oxygraphs O2k, Oroboros, Austria). The pattern of age-related changes differed in each tissue: in the skeletal muscle and kidney cortex of both sexes and in female heart, parameters of mitochondrial respiration significantly declined with age. Resting respiration of intact platelets displayed an increasing trend and it did not correlate with skeletal muscle respiratory states. In the heart of male rats and brain tissues of both sexes, respiratory states remained relatively stable over analyzed age categories with few exceptions of lower mitochondrial oxygen consumption at the age of 24 months. In the liver, OXPHOS capacity was higher in females than in males with either no difference between the ages of 6 and 24 months or even significant increase at the age of 24 months in the male rats. In conclusion, the results of our study indicate that the concept of general pattern of age-dependent decline in mitochondrial oxygen consumption across different organs and tissues could be misleading. Also, the statement of higher mitochondrial respiration in females seems to be conflicting, since the genderrelated differences may vary with the tissue studied, combination of substrates used and might be better detectable at younger ages than in old animals.
Five-sixths nephrectomy is a widely used experimental model of chronic kidney disease (CKD) that is associated with severe mitochondrial dysfunction of the remnant tissue. In this study, we assessed the effect of CKD on mitochondrial respiration separately in the rat kidney cortex and medulla 10 weeks after induction of CKD by subtotal 5/6 nephrectomy (SNX). Mitochondrial oxygen consumption was evaluated on mechanically permeabilized samples of kidney cortex and medulla using high-resolution respirometry and expressed per mg of tissue wet weight or IU citrate synthase (CS) activity. Mitochondrial respiration in the renal cortex of SNX rats was significantly reduced in all measured respiratory states if expressed per unit wet weight and remained lower if recalculated per IU citrate synthase activity, i.e. per mitochondrial mass. In contrast, the profound decrease in the activity of CS in SNX medulla resulted in significantly elevated respiratory states expressing the OXPHOS capacity when Complexes I and II or II only are provided with electrons, LEAK respiration after oligomycin injection, and Complex IV-linked oxygen consumption per unit CS activity suggesting compensatory hypermetabolic state in remaining functional mitochondria that is not sufficient to fully compensate for respiratory deficit expressed per tissue mass. The results document that CKD induced by 5/6 nephrectomy in the rat is likely to cause not only mitochondrial respiratory dysfunction (in the kidney cortex), but also adaptive changes in the medulla that tend to at least partially compensate for mitochondria loss.
The objective of the present study was to evaluate platelet mitochondrial oxygen consumption using high-resolution respirometry (HRR) and metabolic flux analysis (MFA) and to verify the effect of advanced age on these parameters. HRR was used to analyze permeabilized and intact platelets, MFA to measure oxygen consumption rates (OCR), extracellular acidification rates (ECAR) and ATP production rate in intact fixed platelets. Two groups of healthy volunteers were included in the study: YOUNG (20-42 years, n=44) and older adults (OLD; 70-89 years; n=15). Compared to YOUNG donors, platelets from group OLD participants displayed significantly lower values of oxygen consumption in the Complex II-linked phosphorylating and uncoupled states and the Complex IV activity in HRR protocols for permeabilized cells and significantly lower resting and uncoupled respirations in intact cells when analyzed by both methods. In addition, mitochondrial ATP production rate was also significantly lower in platelets isolated from older adults. Variables measured by both methods from the same bloods correlated significantly, nevertheless those acquired by MFA were higher than those measured using HRR. In conclusion, the study verifies compromised mitochondrial respiration and oxidative ATP production in the platelets of aged persons and documents good compatibility of the two most widely used methods for determining the global performance of the electron-transporting system, i.e. HRR and MFA
Hlavní stanovisko práce: Nově odvozená chemorezistentní buněčná linie karcinomu močového měchýře jako experimentální model pro studium mechanizmů mnohočetné terapeutické rezistence pokročilých nádorů močového měchýře. Cíl: Cílem práce bylo odvodit a charakterizovat novou progresivní chemorezistentní buněčnou linii uroteliálního karcinomu. Materiál a metody: Mateřská buněčná linie uroteliálního karcinomu BC44 byla odvozena z papilárně diferencované části pokročilého karcinomu močového měchýře (pT4 G3) a z ní ustanovená dceřiná linie BC44DoxoR byla získána selekcí rezistentních klonů po aplikaci zvyšujících se koncentrací doxorubicinu. Mikroskopická analýza chemorezistentního fenotypu byla fotograficky dokumentována po aplikaci jednotlivých cytostatik (doxorubicin, metotrexát, vinblastin, cisplatina a gemcitabin). Pro stanovení viability buněk v prostředí různých koncentrací cytostatik byl použit test funkce mitochondriálních dehydrogenáz. Ke kvantitativnímu vyhodnocení mitochondriální funkce byla využita metoda absorpční spektrofotometrie a výsledné naměřené hodnoty absorbancí byly zhodnoceny pomocí neparametrického Mann- -Whitney U testu pro hladinu významnosti α = 0,05. Výsledky: Podařilo se nám odvodit z mateřské buněčné linie karcinomu močového měchýře BC44 dceřinou buněčnou linii BC44DoxoR, která vykazuje mnohočetnou lékovou rezistenci vůči všem cytostatikům používaným ve standardní systémové chemoterapii uroteliálního karcinomu (doxorubicin, metotrexát, vinblastin, cisplatina a gemcitabin). Závěr: Nově ustanovená chemorezistentní nádorová buněčná linie BC44DoxoR představuje cenný modelový systém, jehož další molekulární analýza může přinést důležité nové poznatky pro pochopení terapeutické rezistence pokročilých nádorů močového měchýře, Major statement: New chemoresistant urothelial bladder cancer cell line as an experimental model for studying the mechanisms of multidrug resistance in advanced bladder cancer. Aim: The aim of the study was to establish and characterize a new multidrug resistant urothelial cancer cell line. Materials and methods: The parental cancer cell line BC44 was previously established from the large exophytic and better differentiated papillary part of a progressive tumor (pT4 G3) of a female patient. The daughter cell line BC44DoxoR has been derived by prolonged culture in increasing doxorubicin concentrations. Morphological response of parental and daughter cells after application of the individual drugs (doxorubicin, methotrexate, vinblastine, cisplatin, and gemcitabine) has been followed by phase-contrast microscopy. Cell viability has been determined using mitochondrial dehydrogenases assay and quantified by absorption spectrophotometry. Man-Whitney U Test (significance level α = 0.05) has been applied for statistical evaluation. Results: The derivative cell line BC44DoxoR exhibited chemoresistance to all cytostatics tested. To the best of our knowledge, this is the first report of such a multidrug resistant urothelial carcinoma cell line. Conclusion: The new multidrug resistant urothelial bladder cancer cell line could provide important new insights into understanding the therapeutic resistance of advanced bladder cancer., Michaela Kripnerová, Pavel Dvořák, Martin Pešta, Jitka Kuncová, Tomáš Vlas, Martin Leba, Luboš Holubec, Jiří Hatina, and Literatura