A genome-wide functional investigation into the roles of receptor-like proteins in Arabidopsis

Receptor-like proteins (RLPs) are cell surface receptors that typically consist of an extracellular leucine-rich repeat domain, a transmembrane domain, and a short cytoplasmatic tail. In several plant species, RLPs have been found to play a role in disease resistance, such as the tomato (Solanum lycopersicum) Cf and Ve proteins and the apple (Malus domestica) HcrVf2 protein that mediate resistance against the fungal pathogens Cladosporium fulvum, Verticillium spp., and Venturia inaequalis, respectively. In addition, RLPs play a role in plant development; Arabidopsis (Arabidopsis thaliana) TOO MANY MOUTHS (TMM) regulates stomatal distribution, while Arabidopsis CLAVATA2 (CLV2) and its functional maize (Zea mays) ortholog FASCINATED EAR2 regulate meristem maintenance. In total, 57 RLP genes have been identified in the Arabidopsis genome and a genome-wide collection of T-DNA insertion lines was assembled. This collection was functionally analyzed with respect to plant growth and development and sensitivity to various stress responses, including susceptibility toward pathogens. A number of novel developmental phenotypes were revealed for our CLV2 and TMM insertion mutants. In addition, one AtRLP gene was found to mediate abscisic acid sensitivity and another AtRLP gene was found to influence nonhost resistance toward Pseudomonas syringae pv phaseolicola. This genome-wide collection of Arabidopsis RLP gene T-DNA insertion mutants provides a tool for future investigations into the biological roles of RLPs.     

A comparative study of oculomotor,trochlear and abducens nerves in Arabian foals

We investigated the microscopic structure of transverse sections of the oculomotor, trochlear and abducens nerves of Arabian foals using stereological methods. Bilateral nerve pairs from 2-month-old female Arabian foals were analyzed. The tissues were embedded in plastic blocks, then 1 µm thick sections were cut and stained with osmium tetroxide and methylene blue-azure II. Stereology was performed using light microscopy. Morphometry showed that the right and left pairs of nerves were similar. The transverse sectional areas of the oculomotor, trochlear and abducens nerves were 1.93 ± 0.19 mm², 0.32 ± 0.06 mm² and 0.70 ± 0.08 mm², respectively. The oculomotor nerve exhibited a significantly greater number of myelinated axons (16755 ± 1279) and trochlear (2656 ± 494) and the abducens nerves (4468 ± 447). The ratio of the axon diameter to myelinated nerve fiber diameter was 0.58, 0.55 and 0.55 for the oculomotor, trochlear and abducens nerves, respectively. Of the three nerves studied, the abducens nerve exhibited the greatest nerve fiber area, myelin area, nerve and axon diameters, and myelin thickness. The ratio of small myelinated nerve fibers was greatest in the oculomotor nerve.     

Isolation and characterization of stem cells from pancreatic islet: pluripotency,differentiation potential and ultrastructural characteristics

Background aimsStem cells (SC) in different locations have individual characteristics. Important questions to be answered include how these specialties are generated, what the mechanism underlying their generation is, and what their biologic and clinical merits are. A basic approach to answering these questions is to make comparisons between the differences and similarities among the various SC types. They may focus on aspects of biologic marker discovery, capacity of proliferation and differentiation, along with other characteristics. The aim of this study was to characterize in detail the SC isolated from pancreatic islet (PI) and compare their properties with bone marrow (BM)-derived mesenchymal stromal cells (MSC) of the rat.MethodsImmunophenotypic characteristics, proliferation capacities, telomerase activities, pluripotent-related gene expressions, ultrastructure and the potential for multilineage differentiation of PI SC and BM MSC were studied.ResultsWe found that PI SC expressed markers of embryonic SC (Oct-4, Sox-2 and Rex-1) and had a high proliferation capacity, proven also by high telomerase activities. Surprisingly, markers belonging to differentiated cells were expressed by these cells in a constitutive manner. PI SC ultrastructure showed more developed and metabolically active cells.ConclusionsThe immunocytochemical identification of both PI SC and BM MSC was demonstrated to be typical MSC. Without stimulation of differentiation markers of adipogenic, chondrogenic, neurogenic, myogenic and osteogenic cells in these SC, the expression of those markers might explain their multilineage differentiation potential. We suggest that, by reason of the respectively high telomerase activity in PI SC, they could be better candidates than BM MSC for cell replacement therapy of type 1 diabetes.     

Three New Iridoid Glycosides from the Aerial Parts of Asperula involucrata

Three new iridoid glycosides, named involucratosides A – C ( 1  –  3 ), were isolated from the H₂O subextract of crude MeOH extract prepared from the aerial parts of Asperula involucrata along with a known iridoid glycoside (adoxoside), three flavone glycosides (apigenin 7‐O‐β‐glucopyranoside, luteolin 7‐O‐β‐glucopyranoside, apigenin 7‐O‐rutinoside) as well as two phenolic acid derivatives (chlorogenic acid and ferulic acid 4‐O‐β‐glucopyranoside). Their chemical structures were established by UV, IR, 1D‐ (¹H, ¹³C and JMOD) and 2D‐ (COSY, HSQC, HMBC and NOESY) NMR experiments and HR‐ESI‐MS. In addition, the crude extract, subextracts and isolates were evaluated for their xanthine oxidase inhibitory and antioxidant activities in in vitro tests. This is the first report on the chemical composition and bioactivities of A. involucrata.     

An approach for prediction of optimum reaction conditions for laccase-catalyzed bio-transformation of 1-naphthol by response surface methodology (RSM)

Response surface methodology (RSM) was successfully applied to enzymatic bio-transformation of 1-naphthol. The experiments were conducted in a closed system containing acetone and sodium acetate buffer, with laccase enzyme. Laccase enzyme used as catalyst was derived from Trametes versicolor (ATCC 200801). The enzymatic bio-transformation rate of 1-naphthol, based on measurements of initial dissolved oxygen (DO) consumption rate in the closed system, was optimized by the application of RSM. The independent variables, which had been found as the most effective variables on the initial DO consumption rate by screening experiments, were determined as medium temperature, pH and acetone content. A quadratic model was developed through RSM in terms of related independent variables to describe the DO consumption rate as the response. Based on contour plots and variance analysis, optimum operational conditions for maximizing initial DO consumption rate, while keeping acetone content at its minimum value, were 301 K of temperature, pH 6 and acetone content of 7% to obtain 9.17 x 10(-3) mM DO/min for initial oxidation rate.     

Gastroprotective effect of leptin on gastric mucosal injury induced by ischemia-reperfusion is related to gastric histamine content in rats

Leptin has cytoprotective effect to gastric mucosal injury in rats. We aimed to test the hypothesis that leptin induced histamine is involved in the prevention of ischemia-reperfusion (I/R) induced gastric mucosal injury in rats. At the end of the 30 min celiac artery occlusion and 12h reperfusion process, serum and gastric tissue samples were taken from three group of rats to measure oxidative status, histamine levels and for histological examinations. Leptin decreased ulcer and polymorphonuclear leukocyte (PMNL) index, and serum malondialdehyde (MDA) and protein carbonyl content but increased gastric tissue histamine levels. We concluded that leptin exerts a protective effect on gastric mucosa to I/R induced gastric injury probably through increasing tissue histamine content which, in turn, maintain the gastric mucosal blood flow.     

Global gene expression profiling in congenital diaphragmatic hernia (CDH) patients

Functional & Integrative Genomics - Congenital diaphragmatic hernia (CDH) is an anomaly characterized by a defect in the diaphragm, leading to the passage of intra-abdominal organs into the...