Modification of the nitric oxide concentration regulates the development of the apoptosis in the eye retina

Using model elaborated it was shown that the retinal ischemia initiated the development of the apoptosis in the inner layers of the retina. Administration of NOS inhibitor prevented the development of the apoptosis in the retina. To ascertain if nitric oxide could induce the retinal apoptosis by itself the nontoxic donor of nitric oxide (dinitrosyl iron complex) was injected intravitreally. Administration of DNIC in low concentrations induced the development of the apoptosis in the same retinal layers as in ischemia. The injection of dinitrosyl iron complex at the higher concentration resulted in the decrease of the apoptosis level. Administration of dinitrosyl iron complex with excess of glutathione didn't lead to the development of the retinal apoptosis. The obtained data demonstrates the neurotoxic properties of the excess of nitric oxide in the retina.     

A functional analysis of Wnt inducible signalling pathway protein ?1 (WISP-1/CCN4)

Wnt-1 inducible signalling pathway protein 1 (WISP-1/CCN4) is an extracellular matrix protein that belongs to the Cyr61 (cysteine-rich protein 61), CTGF (connective tissue growth factor) and NOV (CCN) family and plays a role in multiple cellular processes. No specific WISP-1 receptors have been identified but emerging evidence suggests WISP-1 mediates its downstream effects by binding to integrins. Here we describe a functional analysis of integrin receptor usage by WISP-1. Truncated WISP-1 proteins were produced using a baculovirus expression system. Full length WISP-1 and truncated proteins were evaluated for their ability to induce adhesion in A549 epithelial cells and β-catenin activation and CXCL3 secretion in fibroblasts (NRK49-F cells). Subsequent inhibition of these responses by neutralising integrin antibodies was evaluated. A549 cells demonstrated adhesion to full-length WISP-1 whilst truncated proteins containing VWC, TSP or CT domains also induced adhesion, with highest activity observed with proteins containing the C-terminal TSP and CT domains. Likewise the ability to induce β-catenin activation and CXCL3 secretion was retained in truncations containing C-terminal domains. Pre-treatment of A549s with either integrin αVβ5, αVβ3 or β1 neutralising antibodies partially inhibited full length WISP-1 induced adhesion whilst combining integrin αVβ5 and β1 antibodies increased the potency of this effect. Incubation of NRK49-F cells with integrin neutralising antibodies failed to effect β-catenin translocation or CXCL3 secretion. Analysis of natural WISP-1 derived from human lung tissue showed the native protein is a high order oligomer. Our data suggest that WISP-1 mediated adhesion of A549 cells is an integrin-driven event regulated by the C-terminal domains of the protein. Activation of β-catenin signalling and CXCL3 secretion also resides within the C-terminal domains of WISP-1 but are not regulated by integrins. The oligomeric nature of native WISP-1 may drive a high avidity interaction with these receptors in vivo.     

Hepatics from Rovno amber (Ukraine), 6. Frullania rovnoi,sp. nov.

A fossil species of the extant liverwort genus Frullania Raddi is described and illustrated, based on a single inclusion in a piece of Rovno amber (Ukraine) that shares its age with Late Eocene Baltic amber, its northern contemporary. Frullania rovnoi is characterised by leaves with a rounded dorsal lobe and the absence of ocelli. The ventral lobe is inflated and forms a saclike lobule, which is bell-shaped and somewhat constricted above the mouth. The bifid underleaves have several blunt teeth or angulations along the shoulder. The Rovno fossil differs sufficiently from morphologically similar species preserved in Baltic and Bitterfeld amber as to be described as new to science. The shape of the lobules and underleaves, as well as the absence of ocelli, indicate an affiliation to F. sect. Australes, hitherto represented in Eocene amber inclusions solely by F. schumannii (Casp.) Grolle. The Rovno fossil is distinguished from extant species of F. subg. Australes and from F. schumannii by having roughly and irregularly dentate-angulate underleaf margins.     

Properties of endoribonuclease activity of proteasomes from K562 cells. II. Analysis of specific mRNA nucleolysis by proteasomes

The ability of 26S proteasomes from the human proerythroleukaemic cell line K562 to degrade high-molecular-weight cytoplasmic RNAs, particularly specific messenger RNA, has been detected. The addition of hemin to K562 cells in the culture media leads to redistribution of proteasomes and their migration mainly to the cytoplasm. The human wild type p53 gene mRNA was shown to be specifically nucleolized by proteasomes. These particles displayed endoribonuclease activity towards mRNA for Renilla sp. luciferase. Proteasomes also specifically degraded Alu-containing mRNAs. A supposition is made about the involvement of proteasomes in stability control of specific RNA groups.     

Mesenchymal stem cell-based HSP70 promoter-driven VEGFA induction by resveratrol promotes angiogenesis in a mouse model

Several studies of stem cell-based gene therapy have indicated that long-lasting regeneration following vessel ischemia may be stimulated through VEGFA gene therapy and/or MSC transplantation for reduction of ischemic injury in limb ischemia and heart failure. The therapeutic potential of MSC transplantation can be further improved by genetically modifying MSCs with genes which enhance angiogenesis following ischemic injury. In the present study, we aimed to develop an approach in MSC-based therapy for repair and mitigation of ischemic injury and regeneration of damaged tissues in ischemic disease. HSP70 promoter-driven VEGFA expression was induced by resveratrol (RSV) in MSCs, and in combination with known RSV biological functions, the protective effects of our approach were investigated by using ex vivo aortic ring coculture system and a 3D scaffolds in vivo model. Results of this investigation demonstrated that HSP promoter-driven VEGFA expression in MSC increased approximately 2-fold over the background VEGFA levels upon HSP70 promoter induction by RSV. Exposure of HUVEC cells to medium containing MSC in which VEGFA had been induced by cis-RSV enhanced tube formation in the treated HUVEC cells. RSV-treated MSC cells differentiated into endothelial-like phenotypes, exhibiting markedly elevated expression of endothelial cell markers. These MSCs also induced aortic ring sprouting, characteristic of neovascular formation from pre-existing vessels, and additionally promoted neovascularization at the MSC transplantation site in a mouse model. These observations support a hypothesis that VEGFA expression induced by cis-RSV acting on the HSP70 promoter in transplanted MSC augments the angiogenic effects of stem cell gene therapy. The use of an inducible system also vastly reduces possible clinical risks associated with constitutive VEGFA expression.     

Capacity of N- and C-domains of <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> flo1p cell wall protein homologue to expose lip2 lipase on cell surface of <Emphasis Type="Italic">Yarrowia lipolytica</Emphasis> yeast

The closest homologue of the Saccharomyces cerevisiae Flo1p cell wall protein was detected in Yarrowia lipolytica yeast (YALI0C09031p) by the method of genomic analysis, and capacity of its N- and C-domains to expose the Lip2 lipase on the cell surface was studied. The efficient fixation of the enzyme on the Y. lipolytica cell wall surface was demonstrated. The activity of the cell-bound lipase was 9170 and 3200 units per 1 g of dry solid matter when using N- and C-domains of the cell wall protein, respectively. At the same time, in the case of immobilization using the N-domain, approximately 30% of the total lipase activity was detected in the culture medium, whereas when using C-domain of the cell wall protein YALI0C09031p, practically all lipase was in the immobilized state. Obtained values of the level of the cell-bound lipase activity considerably exceed previously published data opening a prospect for new technological solutions which meet industrial needs.     

Specificity of changes in proteasome properties in diethylmaleate-induced apoptosis of K562 cells

The participation of proteasome in the programmed cells death is now extensively investigated. Studies using selective inhibitors of proteasomes have provided a direct evidence of both pro- and anti-apoptotic functions of proteasomes. Such opposite roles of 26S proteasomes in regulation of apoptosis may be defined by the proliferative state of cell. The induction of apoptosis in K562 cells by diethylmaleate was used as a model to investigate changes in the subunit composition, phosphorylation state and enzymatic activities of 26S proteasomes undergoing the programmed cell death. Here we have shown that proteasomes isolated from the cytoplasm of control and diethylmaleate treated K562 cells differ in their subunit patterns, as well as in the phosphorylation state of subunits on threonine and tyrosine residues. It has been shown for the first time that proteolytic activity of 26S proteasomes is decreased, and endoribonuclease activity of 26S proteasomes is affected under diethylmaleate action on K562 cells. Treatment of K562 cells with an inductor of apoptosis--diethylmaleate--leads to modification of a proteasomal subunit (zeta/alpha5) associated with RNase activity of proteasomes. These data suggest the subunit composition and enzymatic activities of 26S proteasomes to be changed in K562 cells undergoing apoptosis, and that specific subtypes of 26S proteasomes participate in execution of programmed death of these cells.     

Self-assembly of fibrin monomers and fibrinogen aggregation during ozone oxidation

The mechanism of self-assembly of fibrin monomers and fibrinogen aggregation during ozone oxidation has been studied by the methods of elastic and dynamic light-scattering and viscosimetry. Fibrin obtained from oxidized fibrinogen exhibits higher average fiber mass/length ratio compared with native fibrin. Fibrinogen ozonation sharply reduced the latent period preceding aggregation of protein molecules; however, the mechanism of self-assembly of ozonated and non-ozonated fibrinogen cluster was identical. In both cases flexible polymers are formed and reaching a certain critical length they form densely packed structures and aggregate. Using infrared spectroscopy, it has been shown that free radical oxidation of amino acid residues of fibrinogen polypeptide chains catalyzed by ozone results in formation of carbonyl, hydroxyl, and ether groups. It is concluded that fibrinogen peripheral D-domains are the most sensitive to ozonation, which causes local conformational changes in them. On one hand, these changes inhibit the reaction of longitudinal polymerization of monomeric fibrin molecules; on the other hand, they expose reaction centers responsible for self-assembly of fibrinogen clusters.