Enzymatic component of antioxidative system in succulent plant Tacitus bellus as a response to hemibiotroph Fusarium verticillioides infection in vitro

Fungi and plants interact in different ways, creating a scale of associations. Hemibiotrophic fungi represent the most interesting group, as they use sequential biotrophic and necrotrophic infection strategies. The co-evolution of plant and fungal life-styles has not been well characterized. We present changes of enzymatic component of antioxidative system in succulent plant Tacitus bellus that specifically correspond to subsequent phases (spore germination, biotrophic phase, and necrotrophic phase) of hemibiotroph Fusarium verticillioides infection. T. bellus response to F. verticillioides spore germination was characterized by transient increase in catalase (CAT), but decrease in superoxide dismutase (SOD) and peroxidase (POD) activity. During biotrophic phase of F. verticillioides infection, when hyphae spread intercellularly in epidermal and mesophyll tissue, host antioxidative system was suppressed. The transition from biotrophic to necrotrophic phase (inter and intracellular colonization and sporulation) triggered the host plant cells to create a highly defensive environment: CAT, SOD and POD activities were significantly stimulated, slowing, or even currently arresting, colonization of T. bellus mesophyll cells. CAT, showing the most pronounced activity increase, could be suggested as the main enzyme responsible for slowing the progression of necrotrophic phase of F. verticillioides growth. However, contrary to host CAT and SOD which isoenzyme profile didn’t change, new highly acidic POD isoforms replaced the two mildly acidic isoforms, suggesting their specific role in slowing the progression of infection. Presented results add to knowledge of events and mechanisms related to hemibiotrophic fungi pathogenicity in succulent plants grown under high relative humidity, similar to conditions in greenhouse

Efekti selenita na metabolizam glutationa kod gljive Phycomyces blakesleeanus

Elementarni selen je najmanje biotoksičan oblik selena u prirodi, dok selen-oksianjoni mogu biti toksični zbog značajne pokretljivosti i rastvorljivosti u vodi. Mikrobiološka redukcija selena +4 (selenit) u elementarni selen je stoga od presudnog značaja za smanjenje bioraspoloživosti ovog elementa.1 Visoka reaktivnost selen-oksianjona sa tiolnim grupama, kao i formiranje kiseoničnih radikala u reakciji sa glutationom implicira da oksidativni stres doprinosi toksičnosti selena.2 Tokom biološke redukcije selenita se proizvodi velika količina peroksida čime se indukuje ekspresija gena koji kodiraju enzime antioksidativnog metabolizma, što uključuje i enzime metabolizma glutationa.1 Micelijum gljive Phycomyces blakesleeanus star 24 sata je tretiran 10 mM rastvorom selenita. Uzorci su nakon određenih vremenskih intervala (1, 5, 10, 30, 60 minuta, 24 i 96 sati) ispirani i homogenizovani, nakon čega je meren sadržaj glutationa i specifična aktivnost enzima: peroksidaza (POD), katalaza (CAT), superoksid dismutaza (SOD), glutation peroksidaze (GPx), glutation-S-transferaze (GST) i glutation reduktaze (GR). Nakon dodavanja selenita utvrđen je pad količine ukupnog glutationa u micelijumu. Aktivnost POD i SOD je rasla do 60 minuta, nakon čega je opadala. Aktivnost CAT opadala je odmah po dodatku selenita. Najizraženija je bila promena aktivnosti GPx gde je zabeležen značajan porast, dok su promene aktivnosti GST i GR bile manje izražen

PRODUCTION AND CHARACTERISATION OF SELENIUM NANOPARTICLES BY MYCELIUM OF FUNGUS PHYCOMYCES BLAKESLEEANUS

In this study, mycelium of fungus Phycomyces blakesleeanus was exposed to soluble toxic form of selenium, selenite (Se+4), to examine its ability to reduce it to nanoparticles. Red coloration appeared after only a few hours of incubation with 10 mM Se+4 indicating formation of selenium nanoparticles (SeNPs). SEM-EDS confirmed pure selenium NPs with an average diameter of 57 nm, which indicates to potentially very good medical, optical and photoelectric characteristics. Raman spectroscopy showed several structural forms of SeNPs formed in the extracellular space with a monoclinic Se8 chain as the most represented, and the other observed forms were trigonal Se polymer chain, Se8 ring and Se6 chain structures

SELENITE METABOLISM IN THE MYCELIUM OF THE FUNGUS PHYCOMYCES BLAKESLEEANUS

In this study, mycelium of fungus Phycomyces blakesleeanus was exposed to soluble toxic form of selenium, selenite (Se+4), with the aim of determining the flow and products of its biotransformation. Selenite is reduced to Se0 in the form selenium nanoparticles (SeNPs) and Se-2 in the form of methylated volatile selenides. Low concentrations of Se+4 in the mycelium form RSSeSR type compounds, which could be a step in the process of SeNPs formation, or incorporation of Se into metabolites such as Se-amino acids

Usvajanje i redukcija selenita u micelijama Phycomyces blakesleeanus: uticaj na aktivnost enzima antioksidativne zaštite

Селенити могу бити веома токсични услед оксидативног стреса изазваног интеракцијама са унутарћелијским тиолима. Микробиолошка редукција селенита у елементарни селен, који је најмање токсичан облик селена, је од пресудног значаја за смањење биорасположивости овог елемента. Недавно је потврђено да гљива Phycomyces blakesleeanus има способност редукције селенита до елементарног селена. У овом раду је утврђено да селенит има инхибиторан ефекат на раст мицелије P. blakesleeanus при концентрацијама вишим од 500 μМ. Мицелије су усвајале око 30% селенита који се налазио у медијуму, а плато усвајања је достигнут на медијуму са 1 mM селенитом. Садржај глутатиона и активности ензима мерени су у мицелијама које су гајене у медијуму са 100 μM селенитом који није показивао токсичност. Већ након 3 ч третмана селенитом повећан је садржај оксидованог глутатиона код третираних мицелија у односу на контролу. Уочене су старосно зависне промене у активности ензима и концентрацији глутатиона које су се јављале код третираних мицелија и у контроли: смањење активности каталазе, смањење садржаја укупног глутатиона и повећање активности глутатион редуктазе 24 ч након преношења на свеж медијум са или без селенита. Активност каталазе, глутатион-редуктазе и -трансферазе се статистички значајно повећала у односу на контролу почев од 24 ч третмана селенитом, док је активност глутатион пероксидазе показала двофазни одговор, са повећањем активности 1 ч и 48 ч након преношења на медијум са селенито

Effects of vanadate on glutathione metabolism in mycelium of fungus Phycomyces blakesleeanus

Vanadium enters mycelium of fungus P. blakesleeanus in both +5 and +4 oxidation states. Mycelium in three stages of growth (20h, 36h and 56h) was treated with three concentrations of V+5 (1, 5 and 10 mM) for 1h or 5h. The decrease in viability of mycelium was noticed only at 36h for all applied concentrations. Glutathione has a role in reduction of V+5 to a less toxic form V+4 , so we assayed the changes in total glutathione. Mycelium in early exponential phase of growth (20 h), after 1h or 5h treatment, showed concentration dependent decrease in glutathione, with the largest decrease of 40±4% after 1h and 22±9% after 5h treatment induced by 10 mM V+5. In stationary phase of growth (56h), changes in glutathione concentration were noticed only after 1h of treatment, and the largest decrease (36±6%) was induced by 1 mM V+5. Activities of glutathione reductase (GR), glutathione transferase (GST) and glutathione peroxidase (GPx), have also been examined. Increase in the activities of GPx and GST was noticed in 56h old mycelia treated for 5h with 5 mM and 10 mM V+5, but the only statistically significant increase (54±20%) was noticed in GST activity after 5h of 10 mM V+5 treatment

Lipoprotein(a) in Cardiovascular Diseases

Lipoprotein(a) (Lp(a)) is an LDL-like molecule consisting of an apolipoprotein B-100 (apo(B-100)) particle attached by a disulphide bridge to apo(a). Many observations have pointed out that Lp(a) levels may be a risk factor for cardiovascular diseases. Lp(a) inhibits the activation of transforming growth factor (TGF) and contributes to the growth of arterial atherosclerotic lesions by promoting the proliferation of vascular smooth muscle cells and the migration of smooth muscle cells to endothelial cells. Moreover Lp(a) inhibits plasminogen binding to the surfaces of endothelial cells and decreases the activity of fibrin-dependent tissue-type plasminogen activator. Lp(a) may act as a proinflammatory mediator that augments the lesion formation in atherosclerotic plaques. Elevated serum Lp(a) is an independent predictor of coronary artery disease and myocardial infarction. Furthermore, Lp(a) levels should be a marker of restenosis after percutaneous transluminal coronary angioplasty, saphenous vein bypass graft atherosclerosis, and accelerated coronary atherosclerosis of cardiac transplantation. Finally, the possibility that Lp(a) may be a risk factor for ischemic stroke has been assessed in several studies. Recent findings suggest that Lp(a)-lowering therapy might be beneficial in patients with high Lp(a) levels. A future therapeutic approach could include apheresis in high-risk patients in order to reduce major coronary events

Lipoprotein(a) in Cardiovascular Diseases

Lipoprotein(a) (Lp(a)) is an LDL-like molecule consisting of an apolipoprotein B-100 (apo(B-100)) particle attached by a disulphide bridge to apo(a). Many observations have pointed out that Lp(a) levels may be a risk factor for cardiovascular diseases. Lp(a) inhibits the activation of transforming growth factor (TGF) and contributes to the growth of arterial atherosclerotic lesions by promoting the proliferation of vascular smooth muscle cells and the migration of smooth muscle cells to endothelial cells. Moreover Lp(a) inhibits plasminogen binding to the surfaces of endothelial cells and decreases the activity of �brin-dependent tissue-type plasminogen activator. Lp(a) may act as a proin�ammatory mediator that augments the lesion formation in atherosclerotic plaques. Elevated serum Lp(a) is an independent predictor of coronary artery disease and myocardial infarction. Furthermore, Lp(a) levels should be a marker of restenosis aer percutaneous transluminal coronary angioplasty, saphenous vein bypass gra atherosclerosis, and accelerated coronary atherosclerosis of cardiac transplantation. Finally, the possibility that Lp(a) may be a risk factor for ischemic stroke has been assessed in several studies. Recent �ndings suggest that Lp(a)-lowering therapy might be bene�cial in patients with high Lp(a) levels. A future therapeutic approach could include apheresis in high-risk patients in order to reduce major coronary events

Cardiac fatty acid uptake and metabolism in the rat model of polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is associated with an altered plasma lipid profile and increased risk for cardiovascular diseases. We hypothesized that molecular mechanisms underlying cardiac pathology in PCOS involve changes in expression and subcellular localization of several key proteins involved in cardiac lipid transport and metabolism, such as fatty acid transporter CD36, lipin 1, peroxisome proliferator-activated receptor alpha (PPAR alpha), peroxisome proliferator-activated receptor gamma coactivator-1 (PGC1), and carnitine palmitoyltransferase 1 (CPT1). We used the animal model of PCOS obtained by treating female rats with dihydrotestosterone (DHT). Protein levels of CD36, lipin 1, PPAR alpha, PGC1, and antioxidative enzymes were assessed by Western blot in different cardiac cell compartments. Cardiac triglycerides (TG) and lipid peroxidation were also measured. The content of CD36 was decreased in both the cardiac plasma membranes and intracellular pool. On the other hand, total content of cardiac lipin 1 in DHT-treated rats was elevated, in contrast to decreased microsomal lipin 1 content. An increase in nuclear content of lipin 1 was observed together with elevation of nuclear PPAR alpha and PGC1, and an increase in CPT1 expression. However, lipid peroxidation was reduced in the heart, without alterations in antioxidative enzymes expression and cardiac TG content. The results indicate that treatment of female rats with DHT is accompanied by a decrease of fatty acid uptake and a reduction of lipid peroxidation in the heart. The observed elevation of lipin 1, PPAR alpha, PGC1, and CPT1 expression suggests that cardiac fatty acid metabolism is shifted toward mitochondrial beta oxidation.Ministry of Education, Science and Technological Development, Republic of Serbia {[}III41009