Small Extracellular Vesicle-Associated MiRNAs in Polarized Retinal Pigmented Epithelium.

Purpose: Oxidative stress in the retinal pigmented epithelium (RPE) has been implicated in age-related macular degeneration by impacting endocytic trafficking, including the formation, content, and secretion of extracellular vesicles (EVs). Using our model of polarized primary porcine RPE (pRPE) cells under chronic subtoxic oxidative stress, we tested the hypothesis that RPE miRNAs packaged into EVs are secreted in a polarized manner and contribute to maintaining RPE homeostasis.

Methods: Small EVs (sEVs) enriched for exosomes were isolated from apical and basal conditioned media from pRPE cells grown for up to four weeks with or without low concentrations of hydrogen peroxide using two sEV isolation methods, leading to eight experimental groups.

Transcriptome Analysis of Pterygium and Pinguecula Reveals Evidence of Genomic Instability Associated with Chronic Inflammation.

Solar damage due to ultraviolet radiation (UVR) is implicated in the development of two proliferative lesions of the ocular surface: pterygium and pinguecula. Pterygium and pinguecula specimens were collected, along with adjacent healthy conjunctiva specimens. RNA was extracted and sequenced.

Classification and Nomenclature of Metacaspases and Paracaspases: No More Confusion with Caspases.

Metacaspases and paracaspases are proteases that were first identified as containing a caspase-like structural fold (Uren et al., 2000). Like caspases, meta- and paracaspases are multifunctional proteins regulating diverse biological phenomena, such as aging, immunity, proteostasis and programmed cell death.

HSD18B7 Enzyme Assay Technique Using a Triple Quadrupole Mass Spectrometer.

Enzymes exist in all biological systems to catalyze vital biochemical reactions. The reactivity of an enzyme and the extent of its influence on product formation can give insight to understanding the physiological changes that can take place. The enzyme HSD17B7, involved in the cholesterol biosynthesis pathway, may play a role in influencing underlying changes during transition of disease, specifically in eyes at normal state to eyes that have glaucoma.

Protein-Lipid Complex Separation Utilizing a Capillary Electrophoresis System.

The separation and analysis of protein-lipid complexes has proven to be challenging due to the harsh conditions required by conventional methods of protein or lipid isolation, which disrupt the fine forces that govern the interactions between lipid head groups and protein side chains. The method described in this publication presents an alternative for the separation of protein-lipid complexes while maintaining the integrity of their interactions. The method exploits the specific electrophoretic forces that are unique to the geometry of the capillary system and allows purification of intact complexes and the systematic analysis of its constituents.

Phospholipidomic Studies in Human Cornea From Climatic Droplet Keratopathy.

Climatic droplet keratopathy (CDK) is an acquired degenerative disease predominantly affecting males over 40 years old. It results in progressive corneal opacities usually affecting both eyes. CDK is multifactorial and its etiology remains unknown.

Climatic Droplet Keratopathy in Argentina: Involvement of Environmental Agents in Its Genesis Which Would Open the Prospect for New Therapeutic Interventions.

Climatic droplet keratopathy (CDK) is a degenerative corneal disease of unknown etiology. We described CDK for the first time in Latin America in the Argentinean Patagonia (El Cuy). A deeper knowledge of CDK pathogenic mechanisms will provide new therapeutic strategies.

[Validation of the Schizophrenia Quality Of Life Scale (SQLS) to Measure Quality of Life in Patients Diagnosed With Schizophrenia in Colombia].

Objective: To validate the SQLS scale in Colombian patients diagnosed with schizophrenia.

Method: The self-report scale was applied to 251 patients. Measures of test-retest reliability, internal consistency and correlation inter-scales with the SF-12 were made by applying the scale 2 days later in 28 patients, and 30 days later in 38; 50 patients filled-out the SF-12 scale to determine the concurrent validity.

Molecular modeling and site-directed mutagenesis reveal essential residues for catalysis in a prokaryote-type aspartate aminotransferase.

We recently reported that aspartate (Asp) biosynthesis in plant chloroplasts is catalyzed by two different Asp aminotransferases (AAT): a previously characterized eukaryote type and a prokaryote type (PT-AAT) similar to bacterial and archaebacterial enzymes. The available molecular and kinetic data suggest that the eukaryote-type AAT is involved in the shuttling of reducing equivalents through the plastidic membrane, whereas the PT-AAT could be involved in the biosynthesis of the Asp-derived amino acids inside the organelle. In this work, a comparative modeling of the PT-AAT enzyme from Pinus pinaster (PpAAT) was performed using x-ray structures of a bacterial AAT (Thermus thermophilus; Protein Data Bank accession nos.

The aspartate aminotransferase family in conifers: biochemical analysis of a prokaryotic-type enzyme from maritime pine.

Plant aspartate aminotransferase (AAT, EC 2.6.1.

Identification and functional analysis of a prokaryotic-type aspartate aminotransferase: implications for plant amino acid metabolism.

In this paper, we report the identification of genes from pine (PpAAT), Arabidopsis (AtAAT) and rice (OsAAT) encoding a novel class of aspartate aminotransferase (AAT, EC 2.6.1.

Expression patterns of two glutamine synthetase genes in zygotic and somatic pine embryos support specific roles in nitrogen metabolism during embryogenesis.

Here, embryo-specific patterns of glutamine synthetase (GS) genes were studied for the first time using pine somatic and zygotic embryogenesis as model systems. GS1a expression was absent in zygotic embryos whereas it was detected in the cotyledons of somatic embryos at late developmental stages along with transcripts for photosynthesis genes and arginase. These findings suggest that germination was initiated in maturing somatic embryos.

Molecular aspects of nitrogen mobilization and recycling in trees.

Plants have developed a variety of molecular strategies to use limiting nutrients with a maximum efficiency. N assimilated into biomolecules can be released in the form of ammonium by plant metabolic activities in various physiological processes such as photorespiration, the biosynthesis of phenylpropanoids or the mobilization of stored reserves. Thus, efficient reassimilation mechanisms are required to reincorporate liberated ammonium into metabolism and maintain N plant economy.

Molecular and enzymatic analysis of ammonium assimilation in woody plants.

Ammonium is assimilated into amino acids through the sequential action of glutamine synthetase (GS) and glutamate synthase (GOGAT) enzymes. This metabolic pathway is driven by energy, reducing power and requires the net supply of 2-oxoglutarate that can be provided by the reaction catalysed by isocitrate dehydrogenase (IDH). Most studies on the biochemistry and molecular biology of N-assimilating enzymes have been carried out on annual plant species and the available information on woody models is far more limited.

The promoter of a cytosolic glutamine synthetase gene from the conifer Pinus sylvestris is active in cotyledons of germinating seeds and light-regulated in transgenic Arabidopsis thaliana.

We have isolated and characterized a genomic clone encoding Scots pine (Pinus sylvestris) cytosolic glutamine synthetase (GS). The clone contains the 5' end half of the gene including part of the coding region and 980 bp upstream of the translation initiation codon. The major transcription start site (+1) was mapped around 180 nucleotides upstream of the translation initiation codon.