Recreational scuba diving: negative or positive effects of oxidative and cardiovascular stress?

Environmental conditions and increased physical activity during scuba diving are followed by increased production of free radicals and disturbed redox balance. Redox balance disorder is associated with damage of cellular components, changes of cellular signaling pathways and alterations of gene expression. Oxidative stress leads to increased expression of sirtuins (SIRTs), molecules which play an important role in the antioxidant defense, due to their sensitivity to the changes in the redox status and their ability to regulate redox homeostasis. These facts make SIRTs interesting to be considered as molecules affected by scuba diving and in that sense, as potential biomarkers of oxidative status or possible drug targets in reduction of reactive oxygen species (ROS) accumulation. In addition, SIRTs effects through currently known targets make them intriguing molecules which can act positively on health in general and whose expression can be induced by scuba diving. A demanding physical activity, as well as other circumstances present in scuba diving, has the greatest load on the cardiovascular function (CV). The mechanisms of CV response during scuba diving are still unclear, but diving-induced oxidative stress and the increase in SIRTs expression could be an important factor in CV adaptation. This review summarizes current knowledge on scuba diving-induced oxidative and CV stress and describes the important roles of SIRTs in the (patho)physiological processes caused by the redox balance disorder

Digoksinom označeni lektini kao novo sredstvo za istraživanje glikokonjugata

In recent years it has become clear that carbohydrate portions of glycoconjugates are performing numerous vital physiological functions in higher organisms. However, since glycobiology is a relatively new science, and carbohydrate structures are highly complex, the continuous development of novel analytical techniques is necessary to support the process of understanding the intricate nature of glycoconjugate structure and function. The introduction of digoxin as a novel tag for labelling of lectins that are being used to analyse glycoconjugates in immunoassay-like techniques is described. Lectins labelled with digoxin have significant advantages over biotin- or digoxigenin-labelled lectins and will hopefully prove to be a useful addition to the repertoire of glycobiological tools.Istraživanja provedena tijekom posljednjih godina nedvojbeno su pokazala da šećerni dijelovi glikokonjugata imaju mnoge bitne fiziološke funkcije u viših organizama. Budući da je glikobiologija razmjerno nova znanost, a strukture šećera vrlo složene, potrebno je trajno razvijati nove analitičke postupke koji će unaprijediti spoznaje o zamršenoj strukturi i funkciji glikokonjugata. U ovom je radu opisano uvođenje digoksina kao novog biljega za lektine radi njihove primjene u analitičkim postupcima, kao što je »lectin-western blot« ili histokemija. Lektini obilježeni digoksinom imaju bitne prednosti pred onima obilježenim biotinom ili digoksigeninom i trebali bi biti korisni u glikobiološkim istraživanjima

Glycobiology of psychological stress

Kada je ljudski organizam izložen stresu, preraspodjeljuje svoje energetske izvore u očekivanju nadolazeće opasnosti. Pri tome se najviše aktiviraju motorički i osjetilni sustavi, dok su probavni, imuni, reproduktivni, te ostali sustavi koji nisu nužni u situaciji izravne opasnosti, privremeno prigušeni. To je, naravno, korisno u situaciji stvarne fizičke opasnosti, no, ukoliko takvo stanje traje predugo, ili se ponavlja previše često, neminovno dolazi do oštećenja prigušenih sustava. Stres i njegove posljedice jedan su od ključnih problema suvremenog društva. Između jedne i dvije trećine svih posjeta liječniku posljedica su stresa. Brojna epidemiološka i eksperimentalna ispitivanja, provedena tijekom proteklih godina, jasno su dokumentirala vezu između stresa i pojave, odnosno razvoja brojnih bolesti, a nedavne studije procjenjuju da su i do dvije trećine svih posjeta liječniku uzrokovane stresom. Intenzivna istraživanja molekularnih mehanizama odgovora na psihološki stres, koja se provode u velikom broju laboratorija, postupno razjašnjavaju vezu između stresa i njegovih posljedica. Čini se da su glikokonjugati i njihovi receptori lektini značajno uključeni u taj proces. Detaljno razumijevanje biokemijskih osnova tih složenih procesa otvorit će mogućnost razvoja novih lijekova kojima bi se mogle ublažiti neke od negativnih posljedica stresa.When exposed to stress, human organism re-distributes its sources of energy in the expectation of the coming danger. In such circumstances motor and sensory systems are activated at the most, whereas digestive, immune, reproductive and other systems, not essential in the situation of imminent danger remain temporarily suppressed. This, of course, is beneficial in case of real physical danger, however, if such a state lasts for too long or recurs too often, the suppressed systems inevitably get impaired. Stress and its consequences are one of key issues of the modem society. Somewhere between one and two thirds of all doctors\u27 visits is stress related. Numerous epidemiological and experimental researches in recent years have clearly documented the correlation between stress and incidence of many diseases. The most recent studies estimate two thirds of all doctors\u27 visits to be caused by stress. Intensive research into molecular mechanisms of responses to stress, conducted in many laboratories, gradually explains the correlation between stress and its consequences. Glycoconjugates and their receptors - the lectins seem to be directly involved in that process. Detailed understanding of the biochemical basis of those complex processes will create possibilities for the development of new drugs to alleviate some of the negative impacts of stress

Utjecaj aspirina i indometacina na galektin-3

Galectin-3, a β-galactoside binding lectin, acts as a strong pro inflammatory signal. Many immunomodulatory drugs affect signaling pathways that comprise transcription factors involved in regulation of galectin-3 gene (LGALS3) expression. The aim of this study was to investigate the effects of non-steroidal anti-inflammatory drugs aspirin and indomethacin on the expression of galectin-3, both on mRNA and protein levels. The human monocytic cell line THP-1 was exposed to various therapeutic concentrations of aspirin and indomethacin for 72 hours. Relative RT-PCR method and the GeneScan analysis software were used for assessing the galectin-3 mRNA level and chemiluminescent-western blot analysis was used for measuring the galectin-3 level. The results showed that galectin-3 is a new target molecule of NSAIDs, which cause reduction of both gene and protein expression of galectin-3, but the intensity and time-course of the changes strongly depend on the kind and concentration of the drugs.Galektin-3, lektin koji veže β-galaktozidne jedinice, djeluje kao jak proinflamatorni signal. Mnoge imunomodulatorne tvari utječu na signalne putove i transkripcijske faktore uključene i u regulaciju ekspresije gena za galektin-3 (LGALS3). Cilj je ovoga rada bio ispitati učinke nesteroidnih tvari s imunomodulatornim djelovanjem – aspirina i indometacina – na ekspresiju galektina-3, kako na razini mRNA tako i na razini proteina. Stanice humane stanične linije THP-1 izložene su različitim terapijskim koncentracijama aspirina i indometacina tijekom 72 sata. Količina mRNA za galektin-3 odre|ena je primjenom metode RT-PCR i analize programom GeneScan, a razina galektina-3 kemiluminescentnom western-blot analizom. Rezultati su pokazali da galektin-3 predstavlja novu ciljnu molekulu djelovanja nesteroidnih imunomodulatornih tvari, koje uzrokuju smanjenje ekspresije gena za galektin-3 i samoga proteina, premda jakost promjena i vrijeme njihove pojave jako ovise o vrsti i koncentraciji primijenjene tvari

Kurkumin – snažan inhibitor ekspresije galektina-3

The expression of galectin-3, a b-galactoside binding lectin, was found to be affected by different kinds of stressors, and is strongly modified in numerous physiological and pathophysiological conditions. Although no precise regulatory mechanisms of galectin-3 expression are unraveled, transcription factors AP-1 (activator protein 1) and NF-kB (nuclear factor kappa B) play an important role in these processes. Activities of both transcription factors are affected by curcumin, a biologically active compound extracted from rhizomes of Curcuma species. We have analyzed the impact of curcumin on the expression of galectin-3 in glioblastoma cells under basal conditions and under stress invoked by the cell exposure to alkylating agent N-methyl-N\u27-nitro-N-nitrosoguanidine (MNNG) and ultraviolet C (UV-C) light. Galectin-3 level was measured by western-blot technique using M3/38 monoclonal antibody. Curcumin has decreased the basal level of galectin-3, while the pretreatment of cells with curcumin has considerably reduced the inducible effect of UV-C radiation and abolished the inducible effect of alkylating agent. Thus, curcumin has been identified as a potent inhibitor of galectin-3 expression.Galektin-3, lektin koji specifično prepoznaje b-galaktozidne strukture glikoproteina, sudjeluje u različitim biološkim procesima. Patofiziološka stanja i različiti uzročnici stresa bitno utječu na ekspresiju galektina-3. Premda nisu poznati svi čimbenici u regulacijskom mehanizmu ekspresije galektina-3, pokazano je da u tom procesu sudjeluju transkripcijski faktori AP-1 i NF-kB. Kurkumin, biološki aktivan spoj izoliran iz biljnih podanaka vrste Curcuma, interferira s djelovanjem obaju transkripcijskih faktora. Istražili smo učinak kurkumina na ekspresiju galektina-3 u stanicama glioblastoma u bazalnim uvjetima te u stresu koji je bio izazvan izlaganjem stanica alkilirajućem agensu N-metil-N\u27-nitro-N-nitrozogvanidinu (MNNG) i ultraljubičastom C (UV-C) svjetlu. Razina galektina-3 određena je tehnikom western-blot uz uporabu monoklonskih protutijela M3/38. Utvrđeno je da kurkumin smanjuje bazalnu razinu galektina-3 te da predinkubacija stanica kurkuminom jako smanjuje inducibilni učinak UV-C zračenja, a potpuno uklanja induktivni učinak alkilirajućeg agensa MNNG. Rezultati nedvojbeno pokazuju da je kurkumin snažan inhibitor ekspresije galektina-3

Citotoksični i apoptotički učinci 17α-etinilestradiola i dietilstilbestrola na CHO-K1 stanice

There is considerable concern about the substances present in the environment and their potential to interfere with the endocrine system of vertebrates. Among these, the so-called endocrine-disrupting compounds, which can modulate or disrupt developmental and reproductive processes, substances with estrogenic activity have attracted most attention. Concerns about the presence of these compounds in the environment have led to the development of screening and testing assays that are able to detect such substances and evaluate their potential to induce adverse effects. In vitro systems such as mammalian and fish cell lines have become of growing importance in toxicity testing of such compounds. The cytotoxic and apoptotic effects induced by 17α-ethynylestradiol and diethylstilbestrol were studied on CHO-K1 cell line. Trypan blue exclusion method was used to determine the cell viability. Cytotoxicity of 17α-ethynylestradiol (0.34–34 μM) and diethylstilbestrol (0.37–37 μM) was found to be concentration-dependent with IC50 values of 12.8 and 10.4 μM after 72 h of exposure, respectively. In treated CHO-K1 culture cell death was assessed by determining morphological changes by haematoxilyn and eosin staining, nuclear morphology by fluorescein diacetate/propidium iodide staining and fluorescence microscopy, DNA fragmentation by TUNEL method and translocation of phosphatidyl serine by flow cytometry. The obtained results showed that 17α-ethynylestradiol induced apoptosis, while diethylstilbestrol induced necrosis in the treated CHO-K1 cells.Javnost sve više zabrinjavaju brojne tvari u okolišu koje mogu utjecati na endokrini sustav kralježnjaka. Među tzv. endokrinim modulatorima, koji mogu poremetiti ili potpuno narušiti razvojne i reproduktivne procese u organizmu, najveću pozornost privlače tvari što imaju estrogenu aktivnost. Ta je zabrinutost potaknula razvoj novih metoda za njihovo praćenje i određivanje te izbjegavanje neželjenih učinaka. Testovi in vitro sa staničnim linijama sisavaca i riba postali su važni modelni sustavi u ispitivanju toksičnosti tih spojeva. Citotoksični i apoptotički učinci 17α-etinilestradiola i dietilstilbestrola ispitani su na CHO-K1 staničnoj liniji. Za određivanje preživljavanja stanica upotrebljena je metoda tripan plavo. Citotoksičnost 17α-etinilestradiola (0,34-34 µM) i dietilstilbestrola (0,37-37 µM) ovisi o koncentraciji, a izračunate IC50 vrijednosti nakon 72 sata nakon tretmana iznosile su pojedinačno 12,8 i 10,4 µM. Smrt CHO-K1 stanica praćena je na temelju uočenih morfoloških promjena, bojenjem hematoksilinom i eozinom, zatim promjena u izgledu jezgre, bojenjem fluorescein diacetatom/propidijevim jodidom i fluorescentnom mikroskopijom, te prema fragmentaciji DNA TUNEL metodom i translokaciji fosfatidilserina protočnom citometrijom. Dobiveni rezultati upućuju na to da 17α-etinilestradiol uzrokuje apoptozu u CHO-K1 stanicama, a dietilstilbestrol njihovo odumiranje procesom nekroze

Association of pentraxin-3, galectin-3 and matrix metalloproteinase-9/TIMP-1 with cardiovascular risk in renal disease patients

Inflammation, apoptosis and extracellular remodeling play significant roles in cardiovascular disease (CVD) underlying the major causes of mortality in renal patients. In 19 pre-dialysis patients, 21 dialysis patients and 20 control subjects, the concentrations of pentraxin-3, galectin-3, MMP-9 and TIMP-1 were determined by ELISA. CVD risk was calculated according to the Framingham risk score algorithm. Pentraxin-3 was increased in renal patients compared to healthy controls (p lt 0.001). In contrast, galectin-3 was reduced in hemodialysis patients compared to pre-dialysis patients and controls (p lt 0.001). In addition, MMP-9 and TIMP-1 were elevated in renal patients compared to controls (p lt 0.01 and p lt 0.001, respectively). Logistic regression analyses disclosed associations of galectin-3, MMP-9, pentraxin-3 and glomerular filtration with calculated CVD risk score. Combined testing of pentraxin-3, galectin-3, MMP-9 and glomerular filtration rate can discriminate renal patients with high and low risk of a coronary event

Changes of Glycoprotein Patterns in Sera of Humans under Stress

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