Pervasive migration of organellar DNA to the nucleus in plants

A surprisingly large number of plant nuclear DNA sequences inferred to be remnants of chloroplast and mitochondrial DNA migration events were detected through computer-assisted database searches. Nineteen independent organellar DNA insertions, with a median size of 117 by (range of 38 to >785 bp), occur in the proximity of 15 nuclear genes. One fragment appears to have been passed through a RNA intermediate, based on the presence of an edited version of the mitochondrial gene in the nucleus. Tandemly arranged fragments from disparate regions of organellar genomes and from different organellar genomes indicate that the fragments joined together from an intracellular pool of RNA and/or DNA before they integrated into the nuclear genome. Comparisons of integrated sequences to genes lacking the insertions, as well as the occurrence of coligated fragments, support a model of random integration by end joining. All transferred sequences were found in noncoding regions, but the positioning of organellar-derived DNA in introns, as well as regions 5 and 3 to nuclear genes, suggests that the random integration of organellar DNA has the potential to influence gene expression patterns. A semiquantitative estimate was performed on the amount of organellar DNA being transferred and assimilated into the nucleus. Based on this database survey, we estimate that 3–7% of the plant nuclear genomic sequence files contain organellar-derived DNA. The timing and the magnitude of genetic flux to the nuclear genome suggest that random integration is a substantial and ongoing process for creating sequence variation.Correspondence to: J.L. Blanchard     

Revisiting the use of Iprodione and Trichoderma in the integrated management of onion white rot

The biocontrol properties of Trichoderma species are well documented, but their effectiveness in antagonism of the problematic Sclerotium cepivorum, the causal agent of white rot in Allium species, appears limited with reports of significant control only relating to deliberately-mutated strains of Trichoderma. Our previous studies have indicated the possibility of using selected naturally-occurring strains of the antagonist in the suppression of other diseases; now in vitro and controlled environment in vivo studies have indicated that a degree of control of Onion White Rot is possible, and that the selected antagonist strains can be used in integrated treatments with Iprodione to good effect. The possible value of such treatments is considered in light of other approaches to the suppression of this continuing problem.     

Delphinidin induces antiproliferation and apoptosis of endometrial cells by regulating cytosolic calcium levels and mitochondrial membrane potential depolarization

Endometriosis is a benign gynecological disease of women of reproductive ages, wherein endometrial cells grow ectopically, decreasing their quality of life due to chronic pelvic pain and severe dysmenorrhea. Although surgery and hormone therapies are gold standards for treating endometriosis, side effects are common and the recurrence rate is nearly 50%. Recent studies are exploring phytochemicals as pharmacological adjuvants for treating endometriosis. Delphinidin is an anthocyanin with anti-inflammatory, antioxidative, and anticancerous properties. In this study, delphinidin showed antiproliferative and apoptotic effects on human endometrial cells. Additionally, treatment with delphinidin decreased the mitochondrial membrane potential and increased cytosolic calcium levels in VK2/E6E7 and End1/E6E7 cells. Delphinidin decreased the phosphorylation of proliferative signaling molecules, including ERK1/2, AKT, P70S6K, and S6, while increasing the phosphorylation of P38 MAPK and P90RSK. These results imply that delphinidin is a novel therapeutic agent for treating and managing endometriosis, and has fewer side effects.     

Over-expression of Roquin aggravates T cell mediated hepatitis in transgenic mice using T cell specific promoter

Chronic hepatitis is a major cause of liver cancer, so earlier treatment of hepatitis might be reducing liver cancer incidence. Hepatitis can be induced in mice by treatment with Concanavalin A (Con A); the resulting liver injury causes significant CD4⁺ T cell activation and infiltration. In these T cells, Roquin, a ring-type E3 ubiquitin ligase, is activated. To investigate the role of Roquin, we examined Con A-induced liver injury and T cell infiltration in transgenic (Tg) mice overexpressing Roquin specifically in T cells. In Roquin Tg mice, Con A treatment caused greater increases in both the levels of liver injury enzymes and liver tissue apoptosis, as revealed by TUNEL and H&E staining, than wild type (WT) mice. Further, Roquin Tg mice respond to Con A treatment with greater increases in the T cell population, particularly Th17 cells, though Treg cell counts are lower. Roquin overexpression also enhances increases in pro-inflammatory cytokines, including IFN-γ, TNF-α and IL-6, upon liver injury. Furthermore, Roquin regulates the immune response and apoptosis in Con A induced hepatitis via STATs, Bax and Bcl2. These findings suggest that over-expression of Roquin exacerbates T-cell mediated hepatitis.     

Convenient synthesis of GOLD and MOLD and identification of their oxidation products in vitro and in vivo

Summary. Two Lys–Lys crosslinks, 1,3-bis-(5-amino-5-carboxypentyl)-1H-imidazolium (GOLD) and 1,3-bis(5-amino-5-carboxypentyl)-4-methyl-1H-imidazolium (MOLD) salts, have been synthesized by the reaction of imidazole or 4(5)-methyl imidazole with 5-(4-bromobutyl)-hydantoin followed by the hydrolysis of 1,3-substituted imidazolium derivatives by 6.0 N HCL at 110 °C. Treatment of GOLD and MOLD with hydrogen peroxide in acetic acid leads to MOLD oxidation only. The oxidation product of MOLD was detected in cataractous lens proteins.     

Signal transduction in receptor for advanced glycation end products (RAGE): solution structure of C-terminal rage (ctRAGE) and its binding to mDia1

The receptor for advanced glycation end products (RAGE) is a multiligand cell surface macromolecule that plays a central role in the etiology of diabetes complications, inflammation, and neurodegeneration. The cytoplasmic domain of RAGE (C-terminal RAGE; ctRAGE) is critical for RAGE-dependent signal transduction. As the most membrane-proximal event, mDia1 binds to ctRAGE, and it is essential for RAGE ligand-stimulated phosphorylation of AKT and cell proliferation/migration. We show that ctRAGE contains an unusual α-turn that mediates the mDia1-ctRAGE interaction and is required for RAGE-dependent signaling. The results establish a novel mechanism through which an extracellular signal initiated by RAGE ligands regulates RAGE signaling in a manner requiring mDia1.     

Association of the ACE-II genotype with the risk of nephrotic syndrome in Pakistani children

Nephrotic syndrome is a common pediatric glomerular disease associated with heavy proteinuria. Since, the angiotensin converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism is a putative genetic risk factor for NS, in this study, ACE (I/D) polymorphism was analyzed in 268 NS and 223 control samples by a PCR-based method. The genotypic and allelic frequencies were determined and the association between ACE I/D polymorphism and NS was evaluated. The frequency distribution of the II, ID and DD genotypes was 82 (30.6%), 128 (47.8%) and 58 (21.6%) in the NS patients and 9 (4.0%), 171 (76.7%) and 43 (19.3%) in the control samples respectively. In the Pakistani pediatric NS population, the II genotypic and allelic frequencies were found to be significantly associated with the disease (OR = 6.755; C.I = 3-14.9). No significant association was found between this polymorphism and the response to standard steroid therapy. Thus, in contrast to reports from other parts of the world, the II genotype was found to be significantly associated with NS in the Indian and Malay populations and in the Pakistani population described here. To our knowledge, this is the first report from Pakistan describing the association of the ACE I/D polymorphism with pediatric NS. On the basis of these results, it is suggested that analysis of the ACE (I/D) polymorphism should be performed for the early diagnosis in the high risk NS patients in South Asia.     

Simple and easy method for the determination of fungal growth and decolourative capacity in solid media

A technique was developed for studying the biodegradative ability of white rot fungi in different solid media. This technique enables the gravimetric determination of fungal growth (increase of biomass) and the spectrometric measurement of fungal decolourization ability (both by the determination of the production of the extracellular enzyme manganese-dependent peroxidase (MnP) and by the rate of decolourization of dyes). Bjerkandera sp., strain BOS55, was grown in different solid media. Its growth rate, decolourization of solophenil blue 2BL (azoic dye), neutral red (eurhodin dye), methyl green and crystal violet (triphenylmethane dyes) and the production of MnP were determined. Application of this technique enabled a spectrometric quantification of enzymatic activity. Assays indicate that greater amounts of MnP were present in agar plate cultures of Bjerkandera sp. than in liquid cultures.