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Antagomir
Antagomirs, also known as anti-miRs, are a class of chemically engineered oligonucleotides designed to silence endogenous microRNAs (also known as miRNAs or miRs). Antagomirs are a kind of antisense oligonucleotide, as their sequence is complementary to their specific miRNA target. Their structure has modifications so as to make them more resistant to degradation. These include 2'-methoxy groups on the ribose sugar, backbones with phosphorothioate bonds, and cholesterol conjugation on the 3' end. Mechanism of action Antagomirs are microRNA inhibitors that bind miRNAs and prevent them from binding to a target mRNA molecule, and the consequent degradation of that mRNA via the RNA-induced silencing complex (RISC). Due to the promiscuity of microRNAs, each of which regulate multiple mRNAs, antagomirs can potentially affect the expression of many different mRNA molecules besides the desired target. Blockmirs are similarly engineered molecules which, on the other hand, are designed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MicroRNA
MicroRNA (miRNA) are small, single-stranded, non-coding RNA molecules containing 21 to 23 nucleotides. Found in plants, animals and some viruses, miRNAs are involved in RNA silencing and post-transcriptional regulation of gene expression. miRNAs base-pair to complementary sequences in mRNA molecules, then gene silence said mRNA molecules by one or more of the following processes: (1) cleavage of mRNA strand into two pieces, (2) destabilization of mRNA by shortening its poly(A) tail, or (3) translation of mRNA into proteins. This last method of gene silencing is the least efficient of the three, and requires the aid of ribosomes. miRNAs resemble the small interfering RNAs (siRNAs) of the RNA interference (RNAi) pathway, except miRNAs derive from regions of RNA transcripts that fold back on themselves to form short hairpins, whereas siRNAs derive from longer regions of double-stranded RNA. The human genome may encode over 1900 miRNAs, although more recent analysis sugges ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MIRN21
microRNA 21 also known as hsa-mir-21 or miRNA21 is a mammalian microRNA that is encoded by the ''MIR21'' gene. MIRN21 was one of the first mammalian microRNAs identified. The mature miR-21 sequence is strongly conserved throughout evolution. The human microRNA-21 gene is located on plus strand of chromosome 17q23.2 (55273409–55273480) within a coding gene TMEM49 (also called vacuole membrane protein). Despite being located in intronic regions of a coding gene in the direction of transcription, it has its own promoter regions and forms a ~3433-nt long primary transcript of miR-21 (known as pri-miR-21) which is independently transcribed. The stem–loop precursor of miR-21(pre-miR-21) resides between nucleotides 2445 and 2516 of pri-miR-21. Mature miR-21 Pri-miR-21 is cut by the endonuclease Drosha in the nucleus to produce pre-miR-21, which is exported into the cytosol. This pre-miR-21 is then cut into a short RNA duplex by Dicer in the cytosol. Although abundance of both str ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MiR-122
miR-122 is a miRNA that is conserved among vertebrate species. miR-122 is not present in invertebrates, and no close paralogs of miR-122 have been detected. miR-122 is highly expressed in the liver, where it has been implicated as a regulator of fatty-acid metabolism in mouse studies. Reduced miR-122 levels are associated with hepatocellular carcinoma. miR-122 also plays an important positive role in the regulation of hepatitis C virus replication. Expression and regulation miR-122 was originally identified by cloning of tissue-specific microRNAs in mouse, where its expression is restricted to the liver. The liver-specific expression of miR-122 is conserved in zebrafish. miR-122 expression increases during embryogenesis until it constitutes 72% of total miRNA in adult human liver, making it one of the most highly expressed miRNAs in any tissue. In humans, miR-122 is encoded at a single genomic locus in chromosome 18. The primary miR-122 transcript (pri-miR-122) is a long non- ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-density Lipoprotein
High-density lipoprotein (HDL) is one of the five major groups of lipoproteins. Lipoproteins are complex particles composed of multiple proteins which transport all fat molecules (lipids) around the body within the water outside cells. They are typically composed of 80–100 proteins per particle (organized by one, two or three ApoA. HDL particles enlarge while circulating in the blood, aggregating more fat molecules) and transporting up to hundreds of fat molecules per particle. Overview Lipoproteins are divided into five subgroups, by density/size (an inverse relationship), which also correlates with function and incidence of cardiovascular events. Unlike the larger lipoprotein particles, which deliver fat molecules to cells, HDL particles remove fat molecules from cells. The lipids carried include cholesterol, phospholipids, and triglycerides, amounts of each are variable. Increasing concentrations of HDL particles are associated with decreasing accumulation of atheroscleros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ABCA1
ATP-binding cassette transporter ABCA1 (member 1 of human transporter sub-family ABCA), also known as the ''cholesterol efflux regulatory protein'' (CERP) is a protein which in humans is encoded by the ''ABCA1'' gene. This transporter is a major regulator of cellular cholesterol and phospholipid homeostasis. Tangier disease It was discovered that a mutation in the ABCA1 protein is responsible for causing Tangier disease by several groups in 1998. Gerd Schmitz's group in Germany and Michael Hayden's group in British Columbia were using standard genetics techniques and DNA from family pedigrees to locate the mutation. Richard Lawn's group at CV Therapeutics in Palo Alto, CA used cDNA microarrays, which were relatively new at the time, to assess gene expression profiles from cell lines created from normal and affected individuals. They showed cell lines from patients with Tangier's disease showed differential regulation of the ABCA1 gene. Subsequent sequencing of the gene identifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Macrophage
Macrophages (abbreviated as M φ, MΦ or MP) ( el, large eaters, from Greek ''μακρός'' (') = large, ''φαγεῖν'' (') = to eat) are a type of white blood cell of the immune system that engulfs and digests pathogens, such as cancer cells, microbes, cellular debris, and foreign substances, which do not have proteins that are specific to healthy body cells on their surface. The process is called phagocytosis, which acts to defend the host against infection and injury. These large phagocytes are found in essentially all tissues, where they patrol for potential pathogens by amoeboid movement. They take various forms (with various names) throughout the body (e.g., histiocytes, Kupffer cells, alveolar macrophages, microglia, and others), but all are part of the mononuclear phagocyte system. Besides phagocytosis, they play a critical role in nonspecific defense ( innate immunity) and also help initiate specific defense mechanisms (adaptive immunity) by recruiting othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipoprotein
A lipoprotein is a biochemical assembly whose primary function is to transport hydrophobic lipid (also known as fat) molecules in water, as in blood plasma or other extracellular fluids. They consist of a triglyceride and cholesterol center, surrounded by a phospholipid outer shell, with the hydrophilic portions oriented outward toward the surrounding water and lipophilic portions oriented inward toward the lipid center. A special kind of protein, called apolipoprotein, is embedded in the outer shell, both stabilising the complex and giving it a functional identity that determines its role. Many enzymes, transporters, structural proteins, antigens, adhesins, and toxins are lipoproteins. Examples include plasma lipoprotein particles ( HDL, LDL, IDL, VLDL and chylomicrons). Subgroups of these plasma particles are primary drivers or modulators of atherosclerosis. Scope Transmembrane lipoproteins Some transmembrane proteolipids, especially those found in bacteria, are referre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherosclerosis
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise stress test, amo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligonucleotide
Oligonucleotides are short DNA or RNA molecules, oligomers, that have a wide range of applications in genetic testing, research, and forensics. Commonly made in the laboratory by solid-phase chemical synthesis, these small bits of nucleic acids can be manufactured as single-stranded molecules with any user-specified sequence, and so are vital for artificial gene synthesis, polymerase chain reaction (PCR), DNA sequencing, molecular cloning and as molecular probes. In nature, oligonucleotides are usually found as small RNA molecules that function in the regulation of gene expression (e.g. microRNA), or are degradation intermediates derived from the breakdown of larger nucleic acid molecules. Oligonucleotides are characterized by the sequence of nucleotide residues that make up the entire molecule. The length of the oligonucleotide is usually denoted by " -mer" (from Greek ''meros'', "part"). For example, an oligonucleotide of six nucleotides (nt) is a hexamer, while one of 25 nt w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MiR-33
miR-33 is a family of microRNA precursors, which are processed by the Dicer enzyme to give mature microRNAs. miR-33 is found in several animal species, including humans. In some species there is a single member of this family which gives the mature product mir-33. In humans there are two members of this family called mir-33a and mir-33b, which are located in intronic regions within two gene, protein-coding genes for Sterol regulatory element-binding proteins (SREBP-2 and SREBP-1) respectively. Function miR-33 plays a role in lipid metabolism; it downregulates a number of ABC transporters, including ABCA1 and ABCG1, which in turn regulate cholesterol and High-density lipoprotein, HDL generation. Further related roles of miR-33 have been proposed in fatty acid degradation and in macrophage response to low-density lipoprotein. It has been suggested that miR-33a and miR-33b regulates genes Involved in fatty acid metabolism and insulin signalling. Potential binding sites for mir-33 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caveolin 1
Caveolin-1 is a protein that in humans is encoded by the ''CAV1'' gene. Function The scaffolding protein encoded by this gene is the main component of the caveolae plasma membranes found in most cell types. The protein links integrin subunits to the tyrosine kinase FYN, an initiating step in coupling integrins to the Ras-ERK pathway and promoting cell cycle progression. The gene is a tumor suppressor gene candidate and a negative regulator of the Ras-p42/44 MAP kinase cascade. CAV1 and CAV2 are located next to each other on chromosome 7 and express colocalizing proteins that form a stable hetero-oligomeric complex. By using alternative initiation codons in the same reading frame, two isoforms (alpha and beta) are encoded by a single transcript from this gene. Interactions Caveolin 1 has been shown to interact with heterotrimeric G proteins, Src tyrosine kinases ( Src, Lyn) and H-Ras, cholesterol, TGF beta receptor 1, endothelial NOS, androgen receptor, amyloid precursor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MiR-27
miR-27 is a family of microRNA precursors found in animals, including humans. MicroRNAs are typically transcribed as ~70 nucleotide precursors and subsequently processed by the Dicer enzyme to give a ~22 nucleotide product. The excised region or, mature product, of the miR-27 precursor is the microRNA mir-27. '' Herpesvirus saimiri'' expresses several non-coding RNAs ( HSURs) which have been found to significantly reduce the level of mir-27 in a host cell. It has been proposed that miR-27 operates together with miR-23 and mir-24 in a co-operative cluster. Regulation of adipocyte differentiation miR-27 is one of a number of microRNAs implicated in cholesterol homeostasis and fatty acid metabolism. The miR-27 gene family has been shown to be downregulated during the differentiation of adipocytes. miR-27 inhibits adipocyte formation when overexpressed, acting by blocking the expression of two main regulators of adipogenesis. MicroRNAs miR-27a and -27b have been found to negatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
