Omega-3 fatty acids modulate collagen signaling in human platelets

Dietary intake of the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) results in cardioprotective benefits. However, the cellular and physiological bases for these benefits remain unclear. We hypothesized that EPA and DHA treatments would interfere with collagen-mediated platelet signaling. Thirty healthy volunteers received 28 days of 3.4 g/d EPA+DHA with and without a single dose of aspirin. Clinical hematologic parameters were then measured along with assays of collagen-stimulated platelet activation and protein phosphorylation. Omega-3 therapy led to a small but significant reduction in platelets (6.3%) and red blood cells (1.7%), but did not impair clinical time-to-closure assays. However, collagen-mediated platelet signaling events of integrin activation, α-granule secretion, and phosphatidylserine exposure were all reduced by roughly 50% after omega-3 incorporation, and collagen-induced tyrosine phosphorylation was significantly impaired. The diminished platelet response to collagen may account for some of the cardioprotective benefits provided by DHA and EPA.     

Changes in antioxidant activities and phenol content in tomato plants subjected to partial root drying and regulated deficit irrigation

Abstract

Partial rootzone drying (PRD) and regulated deficit irrigation (RDI) are water saving irrigation systems that have been developed to increase water use efficiency (WUE) without significant yield reduction. To examine whether tomato responded differently to RDI and PRD, we compared the changes in antioxidative defenses in tomato plants using a split-root system. Tomato plants were grown for 21 days under controlled conditions with their roots separated equally between two soil compartments. Three irrigation treatments were imposed: Control, receiving an amount of water equivalent to 100% of plant transpiration; PRD in which one compartment was watered with 50% of the amount of water supplied to the controls, allowing one-half of the root system to be exposed to dry soil, and switching irrigation between sides weekly; RDI in which 50% of the amount of water given to the controls was supplied, half to each side of the root system. Relative water content (RWC), midday leaf Ψ and chlorophyll content decreased largely in RDI-treated plants, whereas the PRD plants exhibited relatively higher Ψ and RWC values. An enhanced level of lipid peroxidation in both roots and leaves indicated that PRD and RDI caused oxidative stress in tomato plants. In leaves, superoxide dismutase (SOD), soluble peroxidase (POX) and polyphenol oxidase (PPO) activities showed an increase in the early phase of water deficit, and then decreased in the remaining phase of the drying cycle. However, the increase was more pronounced under RDI. Catalase (CAT) activity declined continuously from the onset of PRD and RDI treatments to below the control level, and the reduction was less under PRD than RDI. POX cell-wall associated activities exceeded the control level by 450% and 230%, respectively, under RDI and PRD. At the root level, while CAT activity also decreased under both PRD and RDI, the activities of SOD, POX and PPO significantly increased and their activities showed an alternating increase/decrease paralleling the alternating irrigation in PRD-treated roots. As a result of the difference in POX and PPO activities between the two water treatments applied, PRD-treated plants accumulated more soluble and cell-wall bound phenolic compounds.     

DockRank: Ranking docked conformations using partner‐specific sequence homology‐based protein interface prediction

Selecting near‐native conformations from the immense number of conformations generated by docking programs remains a major challenge in molecular docking. We introduce DockRank, a novel approach to scoring docked conformations based on the degree to which the interface residues of the docked conformation match a set of predicted interface residues. DockRank uses interface residues predicted by partner‐specific sequence homology‐based protein–protein interface predictor (PS‐HomPPI), which predicts the interface residues of a query protein with a specific interaction partner. We compared the performance of DockRank with several state‐of‐the‐art docking scoring functions using Success Rate (the percentage of cases that have at least one near‐native conformation among the top m conformations) and Hit Rate (the percentage of near‐native conformations that are included among the top m conformations). In cases where it is possible to obtain partner‐specific (PS) interface predictions from PS‐HomPPI, DockRank consistently outperforms both (i) ZRank and IRAD, two state‐of‐the‐art energy‐based scoring functions (improving Success Rate by up to 4‐fold); and (ii) Variants of DockRank that use predicted interface residues obtained from several protein interface predictors that do not take into account the binding partner in making interface predictions (improving success rate by up to 39‐fold). The latter result underscores the importance of using partner‐specific interface residues in scoring docked conformations. We show that DockRank, when used to re‐rank the conformations returned by ClusPro, improves upon the original ClusPro rankings in terms of both Success Rate and Hit Rate. DockRank is available as a server at http://einstein.cs.iastate.edu/DockRank/ . Proteins 2014; 82:250–267. © 2013 Wiley Periodicals, Inc.     

Thymol and Carvacrol Prevent Cisplatin‐Induced Nephrotoxicity by Abrogation of Oxidative Stress,Inflammation, and Apoptosis in Rats

The aim of the present study is to assess the possible protective effects of thymol and carvacrol against cisplatin (CP)‐induced nephrotoxicity. A single dose of CP {6 mg/kg, intraperitoneally (i.p.)} injected to male rats revealed significant increases in serum urea, creatinine, and tumor necrosis factor alpha levels. It also increased kidney contents of malondialdehyde and caspase‐3 activity with significant reduction in serum albumin, kidney content of reduced glutathione as well as catalase, and superoxide dismutase activity as compared to that of the control group. In contrast, administration of thymol {20 mg/kg, orally (p.o.)} and/or carvacrol (15 mg/kg, p.o.) for 14 days before CP injection and for 7 days after CP administration restored the kidney function and examined oxidative stress parameters. In conclusion, thymol was more effective nephroprotective than carvacrol. Moreover, a combination of thymol and carvacrol had a synergistic nephroprotective effect that might be attributed to antioxidant, anti‐inflammatory, and antiapoptotic activities.     

Potentiality of Different Seed Priming Agents to Mitigate Cold Stress of Winter Rice Seedling

Seed priming has proved to be an effective pre-germination seed invigoration technique for different crops to improve seed and seedling performance under different abiotic stresses. In Bangladesh, winter rice is very often exposed to cold waves just after sowing in the nursery bed resulting in poor seed germination and seedling emergence, yellowish and thin seedlings production, and a very low survival rate. Seed priming may mitigate the cold stress during seed germination and seedling emergence and helps in the quality seedling production of winter rice. To evaluate the efficacy of different seed priming techniques in increasing seedling emergence, growth, vigor and survivability of winter rice cultivars under cold stress, a pot experiment was conducted at the Department of Agronomy, Bangladesh Agricultural University during December 2018 to January 2019. The experiment comprised two factors, (A) Winter rice variety namely, i) BRRI dhan29 and ii) BRRI dhan36; (B) Seed priming agent namely i) Control (no priming), ii) 20000 ppm NaCl, iii) 30000 ppm NaCl, iv) 20000 ppm KCl, v) 30000 ppm KCl, vi) 20000 ppm CaCl₂, vii) 30000 ppm CaCl₂, viii) 50 ppm CuSO₄, ix) 75 ppm CuSO₄, x) 10000 ppm ZnSO₄, xi) 15000 ppm ZnSO₄, xii) 2 ppm Na₂MoO₄, xiii) 3 ppm Na₂MoO₄, xiv) 100 ppm PEG (Polyethylene glycol 4000) and xv) 150 ppm PEG. Seeds were sown on two different dates viz., 1st December and 1st January so that seedlings are exposed to cold stress at different stages. The experiment was laid out in a completely randomized design (CRD) with three replications. Results indicated that (in most of the cases) seed priming has a positive impact on seedling emergence rate (%), root length, shoot length, root shoot ratio, root dry weight, shoot dry weight, seedling dry weight and survival rate (%). Among the priming agents, KCl and CaCl₂ performed best; while priming with NaCl and PEG showed no advantages over no priming for both the sowing dates. In general, BRRI dhan36 performed better than BRRI dhan29 in terms of seedling growth because of its higher tolerance to cold stress. But, both the varieties performed similarly in terms of emergence rate and survival rate. Thus, priming is an effective tool to increase seed germination, better seedling growth, and higher seedling survivability of winter rice under cold stress, and KCl (20000 ppm) or CaCl₂ (20000 ppm) can be considered as a viable priming agent.     

Lactosylceramide induced by elastin-derived peptides decreases adipocyte differentiation

Journal of Physiology and Biochemistry - Elastin, the major protein of the extracellular matrix, is specially found in cardiovascular tissues and contributing to 30–50% of the dry weight of...     

Oxidative Stress Tolerance Mechanism in Rice under Salinity

The research was conducted to investigate comparative oxidative damage including probable protective roles of antioxidant and glyoxalase systems in rice (Oryza sativa L.) seedlings under salinity stress. Seedlings of two rice genotypes: Pokkali (tolerant) and BRRI dhan28 (sensitive) were subjected to 8 dSm⁻¹ salinity stress for seven days in a hydroponic system. We observed significant variation between Pokkali and BRRI dhan28 in phenotypic, biochemical and molecular level under salinity stress. Carotenoid content, ion homeostasis, antioxidant enzymes, ascorbate and glutathione redox system and proline accumulation may help Pokkali to develop defense system during salinity stress. However, the activity antioxidant enzymes particularly superoxide dismutase (SOD), catalase (CAT) and non-chloroplastic peroxidase (POD) were observed significantly higher in Pokkali compared to salt-sensitive BRRI dhan28. Higher glyoxalase (Gly-I) and glyoxalase (Gly-II) activity might have also accompanied Pokkali genotype to reduce potential cytotoxic MG through non-toxic hydroxy acids conversion. However, the efficient antioxidants and glyoxalase system together increased adaptability in Pokkali during salinity stress.     

High-Speed Cell Sorting of Infectious Trophic and Cystic Forms of Pneumocystis carinii

ABSTRACT. The separation of Pneumocystis carinii life-cycle stages while preserving infectivity is a hitherto unresolved challenge. We describe an original, reproducible, and efficient method for separating trophic from cystic forms of P. carinii using a high-speed cell sorter. The large amounts of highly purified (99.6±0.3%) infectious trophic and cystic forms can now be used to elucidate the poorly understood P. carinii life cycle.     

Genetic footprints of late Quaternary climate change in the diversity of Patagonian‐Fueguian rodents

Species are impacted by climate change at both ecological and evolutionary time scales. Studies in northern continents have provided abundant evidence of dramatic shifts in distributions of species subsequent to the last glacial maximum (LGM), particularly at high latitudes. However, little is known about the history of southern continents, especially at high latitudes. South America is the only continent, other than Antarctica, that extends beyond 40 °S. Genetic studies of a few Patagonian species have provided seemingly conflicting results, indicating either postglacial colonization from restricted glacial refugia or persistence through glacial cycles and in situ differentiation. Using mitochondrial DNA sequences of 14 species of sigmodontine rodents, a major faunal ensemble of Patagonia and Tierra del Fuego, we show that at least nine of these species bear genetic footprints of demographic expansion from single restricted sources. However, timing of demographic expansion precedes the LGM in most of these species. Four species are fragmented phylogeographically within the region. Our results indicate that (i) demographic instability in response to historical climate change has been widespread in the Patagonian‐Fueguian region, and is generally more pronounced at high latitudes in both southern and northern continents; (ii) colonization from lower latitudes is an important component of current Patagonian‐Fueguian diversity; but (iii) in situ differentiation has also contributed to species diversity.