Application of Nanotechnology for Sensitive Detection of Low-Abundance Single-Nucleotide Variations in Genomic DNA: A Review

Single-nucleotide polymorphisms (SNPs) are the simplest and most common type of DNA variations in the human genome. This class of attractive genetic markers, along with point mutations, have been associated with the risk of developing a wide range of diseases, including cancer, cardiovascular diseases, autoimmune diseases, and neurodegenerative diseases. Several existing methods to detect SNPs and mutations in body fluids have faced limitations. Therefore, there is a need to focus on developing noninvasive future polymerase chain reaction (PCR)–free tools to detect low-abundant SNPs in such specimens. The detection of small concentrations of SNPs in the presence of a large background of wild-type genes is the biggest hurdle. Hence, the screening and detection of SNPs need efficient and straightforward strategies. Suitable amplification methods are being explored to avoid high-throughput settings and laborious efforts. Therefore, currently, DNA sensing methods are being explored for the ultrasensitive detection of SNPs based on the concept of nanotechnology. Owing to their small size and improved surface area, nanomaterials hold the extensive capacity to be used as biosensors in the genotyping and highly sensitive recognition of single-base mismatch in the presence of incomparable wild-type DNA fragments. Different nanomaterials have been combined with imaging and sensing techniques and amplification methods to facilitate the less time-consuming and easy detection of SNPs in different diseases. This review aims to highlight some of the most recent findings on the aspects of nanotechnology-based SNP sensing methods used for the specific and ultrasensitive detection of low-concentration SNPs and rare mutations

α2B-ADRENOCEPTORS IN THE REGULATION OF VASCULAR SMOOTH MUSCLE CELL CONTRACTION AND PROLIFERATION

α2-Adrenoceptors (α2-ARs) belong to the large superfamily of G protein-coupled receptors (GPCRs). They mediate important actions of the endogenous catecholamines adrenaline and noradrenaline. All three α2-AR subtypes are involved in the regulation of blood pressure and vascular tone. α2-ARs can regulate both vascular smooth muscle contraction and remodeling of the blood vessel wall, but the intracellular signaling mechanisms involved in these functions have remained largely unknown. The aim of this thesis was to investigate the involvement of the α2B-AR subtype in the regulation of the contraction and proliferation of vascular smooth muscle cells (VSMC), and to clarify the related cellular signaling mechanisms. In order to characterize the effects of α2B-AR activation on VSMC contraction and proliferation and to investigate whether these functions could be altered by drug treatment, a VSMC line stably expressing the human α2B-AR was generated by transfection of rat A7r5 cells. Characterization of the novel A7r5-α2B cell line indicated that the localization and ligand binding properties of the expressed α2B-ARs were in line with earlier studies of α2B-ARs in different host cell environments, and that the receptors had the expected pharmacological characteristics. Therefore, the generated A7r5-α2B cell line was regarded as a useful tool for investigating the functions and regulation of α2B-ARs in VSMCs. α2B-ARs were demonstrated to be capable of mediating VSMC contraction by using a functional assay measuring myosin light chain phosphorylation, which is a biochemical readout of VSMC contraction. The network of signaling pathways involved in α2B-AR-mediated contraction of A7r5 VSMCs appeared to be complex and seemed to involve many mediators, such as Gi proteins, Gβγ subunits, phospholipase C (PLC), protein kinase C (PKC) and L-type Ca2+ channels. Different screening assays, namely DNA microarray, small inhibitor compound library screening and kinase activity profiling, were used to investigate the genetic regulation and intracellular signaling mechanisms involved in α2BAR-evoked proliferation of A7r5 VSMCs. The cellular mechanisms and signal transduction pathways participating in this response appeared to be complex and included redundancy. The employed screening assays and their respective data analysis approaches were found to be useful as tools to map the activation of cellular signaling networks in a situation where the exact mechanisms still remain unknown. These screening tools were considered suitable for hypothesis generation, but additional approaches will be required for further hypothesis testing.α2-Adrenergiset reseptorit (α2-AR) ovat G-proteiinikytkentäisiä reseptoreita (GPCR). Ne aktivoituvat adrenaliinin ja noradrenaliinin vaikutuksesta ja välittävät monia tärkei- tä elimistön säätelytehtäviä. Kaikki kolme α2-AR-alatyyppiä osallistuvat verenpaineen säätelyyn. Ne voivat säädellä sekä verisuonen sileän lihaksen (VSL) supistumista että verisuonen seinämän rakenteessa tapahtuvia muutoksia. Näihin toimintoihin liittyvät solusisäiset viestintämekanismit ovat vielä suurelta osin tuntemattomia. Tämän väi- töstutkimuksen tavoitteena oli selvittää α2B-reseptorialatyypin merkitystä VSL-solujen supistumisen ja proliferaation säätelyssä ja näitä vaikutuksia välittäviä solutason vies- tintämekanismeja. Rotan A7r5-solulinjan VSL-soluihin siirrettiin ihmisen α2B-reseptoria koodittava geeni. Tämä tuotti VSL-solumallin, jonka avulla voitiin tutkia α2B-reseptorien vaikutuksia VSL-so- lujen supistumiseen ja proliferaatioon. Kehitetyn A7r5-α2B -solulinjan reseptorien sijainti ja farmakologiset ominaisuudet olivat odotuksia vastaavat. Tämän validoinnin perusteella A7r5-α2B-solulinjan todettiin soveltuvan α2B-reseptorien toiminnan tutkimiseen VSL-so- luissa. Väitöstutkimuksessa osoitettiin, että α2B-reseptorit välittävät VSL-solujen supistus- vasteita. Tätä tutkittiin mittaamalla myosiinin kevytketjujen fosforylaatiota, sillä myosiinin kevytketjujen fosforylaatio on VSL-solujen supistuksen kannalta keskeinen biokemialli- nen tapahtuma. A7r5-soluissa α2B-välitteiseen supistusvasteeseen liittyvät solunsisäiset viestintämekanismit osoittautuivat monimutkaisiksi ja niihin osallistui monia viestinvälit- täjiä, kuten Gi-proteiinit, Gβγ-alayksiköt, fosfolipaasi C, proteiinikinaasi C ja L-tyypin kal- siumkanavat. DNA-mikrosirumäärityksillä, kinaasi/fosfataasi-inhibiittorikirjaston seulon- nalla ja kinaasiaktivaatiota mittaavilla mikrosirumäärityksillä selvitettiin α2B-välitteiseen VSL-solujen proliferaatiovasteeseen liittyvää geenien ilmentymisen säätelyä ja solunsisäi- siä viestintämekanismeja. VSL-solujen proliferaatiovasteen syntyyn liittyvät mekanismit ja viestintäreitit osoittautuivat monimutkaisiksi ja osittain päällekkäisiksi. Käytetyt seulonta- menetelmät ja niihin sovellettavat analyysit todettiin käytännölliseksi lähestymistavaksi tilanteessa, jossa halutaan kartoittaa ennalta tuntemattomia solunsisäisiä viestintämeka- nismeja. Seulontamenetelmät todettiin hyödyllisiksi uusien havaintojen tuottamisessa, mutta havaintojen tuottamien hypoteesien testaamiseen tarvitaan muita, kohdennettuja menetelmiä

Advances in Bioengineering

The technological approach and the high level of innovation make bioengineering extremely dynamic and this forces researchers to continuous updating. It involves the publication of the results of the latest scientific research. This book covers a wide range of aspects and issues related to advances in bioengineering research with a particular focus on innovative technologies and applications. The book consists of 13 scientific contributions divided in four sections: Materials Science; Biosensors. Electronics and Telemetry; Light Therapy; Computing and Analysis Techniques

40th Rocky Mountain Conference on Analytical Chemistry

Final program, abstracts, and information about the 40th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 25 - August 1, 1998

Role of adipose tissue in the pathogenesis and treatment of metabolic syndrome

© Springer International Publishing Switzerland 2014. Adipocytes are highly specialized cells that play a major role in energy homeostasis in vertebrate organisms. Excess adipocyte size or number is a hallmark of obesity, which is currently a global epidemic. Obesity is not only the primary disease of fat cells, but also a major risk factor for the development of Type 2 diabetes, cardiovascular disease, hypertension, and metabolic syndrome (MetS). Today, adipocytes and adipose tissue are no longer considered passive participants in metabolic pathways. In addition to storing lipid, adipocytes are highly insulin sensitive cells that have important endocrine functions. Altering any one of these functions of fat cells can result in a metabolic disease state and dysregulation of adipose tissue can profoundly contribute to MetS. For example, adiponectin is a fat specific hormone that has cardio-protective and anti-diabetic properties. Inhibition of adiponectin expression and secretion are associated with several risk factors for MetS. For this purpose, and several other reasons documented in this chapter, we propose that adipose tissue should be considered as a viable target for a variety of treatment approaches to combat MetS

38th Rocky Mountain Conference on Analytical Chemistry

Final program, abstracts, and information about the 38th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 21-26, 1996