Posts Tagged ‘antibody catalogue’

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Profiling the Profilin 1 Antibody

Monday, July 25th, 2011

Profilin-1, or Pfn-1, is a small actin-binding protein which plays an essential role controlling the growth of microfilaments. Profilin I and profilin II have similar biochemical properties but are expressed in different tissues. The profilin I antibody targets the more common form of the protein, which is expressed everywhere but the skeletal muscle. We at Novus Biologicals have an extensive range of profilin I antibody products in our antibody catalogue.

Profilin regulates the spatial and temporal growth of actin microfilaments, thus aiding cellular migration, changes in cellular morphology, and processes such as organ development and wound healing to take place. Profilin mainly binds to actin, but has over 50 binding partners in total. Profilin I antibody studies have shown that the protein may have other functions apart from actin regulation.

Profilin is mainly found in the cytosol, with the highest levels found in dynamic areas such as the leading edge and ruffling membranes. Although profilin is traditionally thought of as a promigratory molecule, recent profilin 1 antibody studies suggest the protein is down-regulated in certain adenocarcinomas, with reduced expression linked to increased motility of invasive tumour cells.

In 2010, Y.H Bae et al showed profilin1 negatively regulates lamellipodin (Lpd), an Ena/VASP ligand and PI(3,4)P2-binding protein, at the lamellipodium (actin protrusion found in highly motile cells). In breast cancer cells, phosphoinositide binding of profilin I inhibited cell motility by negative regulation of PI(3,4)P2. This in turn limited recruitment of lamellipodin and Ena/VASP to the leading edge, and therefore reduced motility.

Our profilin antibody catalog is helping to sculpt researchers’ understanding of profilin1-phosphoinositide interaction, and its effect on cell motility independent of actin-related effects.

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The Sox2 Antibody Aids Brain Cancer Research

Wednesday, June 22nd, 2011

The Sox2 antibody is widely used in sensory, neural and stem cell marker research. Recently, Sox2 antibody preparations identified the Sox2 protein as a marker for malignant neural gliomas in human surgical tissue. We at Novus Biologicals recently added three new Sox2 antibody products to our antibody catalog.

SOX2 (also known as SRY-related HMG BOX gene 2), encodes a transcription factor essential to embryonic stem cell pluripotency and early neural development. It forms a trimeric complex with OCT4, controlling expression of YES1, FGF4 and a number of other genes influencing embryonic development. In 2008, Zhao et al identified Sox2 as a key transcription factor for induced pluripotent stem cells, deducing its main function was to regulate Oct4 expression.

SOX2 mutations are associated with serious developmental and visual defects in children. Recently, the protein was found to up-regulate pepsinogen expression in the stomach; ectopic expression may play a role in the development of certain colorectal cancers. Now, scientists at Turin University have revealed a correlation between SOX2 expression and the development of malignant gliomas in human adults.

Annovazzi et al used Sox2 antibody preparations in immunohistochemistry, immunofluorescence and Western blot assays, to look at SOX2 expression in 16 glioblastoma cell lines, and in 133 surgical samples taken from brain gliomas of varying malignancy. SOX2 amplification correlated positively with hyperproliferation of glioblastoma cells, and the more severe grades of surgical glioma. However, SOX2 was not expressed in neuronal tumours, and its expression in medulloblastomas was dependant upon the degree of neuronal differentiation.

In future studies, the Sox2 antibody reagents in our antibody catalogue will further probe the development of glioblastomas and oligodendrogliomas in human patients.

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The Ki67 Antibody in Cell Marker Studies

Monday, May 30th, 2011

The MK167, or Ki67 antibody recognizes a nuclear protein encoded by the MK167 gene. Ki167 is involved with RNA transcription and essential to cellular proliferation, being expressed by proliferating cells at all stages of the active cell cycle; it is exclusively used as a marker for cellular proliferation. The Ki67 antibody is a useful tool in cancer research and neuronal studies; however, MIB-1 antibodies also target the Ki67 marker and are preferred for clinical use.

During interphase, Ki67 is exclusively located in the nucleus, but relocates to the chromosome surface during cell division. The Ki67 antibody is a highly useful aid for determining the growth faction of cell populations in neoplasms and tumours, particularly those of the brain, prostate and breast. The faction of Ki67-positive tumour cells is called the Ki-67 labelling index, the value of which strongly correlates to the clinical development of cancer. Low Ki67 indices are indicative of low-grade tumours and a more favourable outcome for the patient.

For determining the Ki67 index in clinical applications, the Ki67 antibody has largely been superseded by MIB1 antibodies. This is because they were found to target the Ki67 antigen in the same way, but with the added advantage of being viable for use in paraffin-embedded immunohistochemistry assays, following microwave-mediated antigen retrieval. This situation has improved, and today around half the Ki67 antibodies we at Novus Biologicals have in our antibody catalog can be used for paraffin embedded sections. However, these products are exclusively for research use only, and MIB1 antibodies remain the norm in the clinical environment.

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Signalling Advances in Adiponectin Antibody Research

Monday, May 16th, 2011

Adiponectin is an adipocytokine protein that positively regulates metabolism of lipids and glucose by suppressing glucose production from the liver, stimulating insulin sensitivity, and increasing the rate of fatty acid oxidation and glucose uptake. Insulin resistance, obesity and dyslipidemia (abnormal blood lipid levels) are all linked to Adiponectin deficiency. The Adiponectin antibody is also used in Type 2 Diabetes research.

In recent years, a number of antibody studies have focussed on the metabolic pathways governing Adiponectin. In 2003, Yamauchi et al identified two Adiponectin receptors, Adipo R1 and Adipo R2. Subsequent experiments showed Adipo R1 to be the primary receptor in skeletal muscle, which is the body’s main glucose-utilising tissue. However, the underlying mechanism of action remained unclear.

In 2010, M. Iwabu et al published a paper which significantly advanced Adiponectin antibody research, disclosing new facts about the Adipo R1 signalling pathway. Using mice depleted of skeletal muscle Adipo R1- (m-Adipo R1KO), the researchers were able to confirm Adipo R1 affected insulin sensitivity and glucose tolerance. Markedly higher insulin and plasma glucose levels were recorded in m-Adipo R1KO mice than wild-type controls, while antibody assays also revealed marked alterations in insulin-induced phosphorylation of key signalling molecules, including Akt, IRS-1, JNK and p70 S6 kinase. The m-Adipo R1KO group also showed decreased mitochondrial biogenesis, with reduced levels of mitochondrial proteins, PGC1 alpha transcription factor and mitochondrial DNA.

The m-Adipo R1KO mice also demonstrated enhanced oxidative stress coupled with impaired oxidation of fatty acids, a common occurrence with insulin resistance. These effects were partially reversed by exercise, showing exercise may be a useful therapeutic tool in cases of impaired Adiponectin function. We at Novus Biologicals have a wide range of Adiponectin antibody products in stock.

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Actin Nucleators and Other Developments in Actin Antibody Research

Friday, May 13th, 2011

A highly conserved, abundant protein found in practically all eukaryotic cells, actin is a monomeric subunit of skeletal muscle thin filaments, and cytoskeleton microfilaments. Actin antibody products are routinely used in cell marker and loading control assays. However, actin antibody reagents are also used for cytoskeleton, cell motility, cytokinesis and cell signalling research. Our antibody catalog covers all the actin isoforms, with an extensive range of alpha, beta and gamma actin antibody products.

Actin antibody studies have revealed polymerization and depolymerization of actin to be essential to chemotaxis (cell motility) and cytokinesis (cell division). Polymerization is dependent upon nucleating factors such as ARP and the formin protein family. The Arp1/2 complex has been widely studied by actin antibody researchers. The Arp1 and 2 proteins mimic the structure of monomeric actin, forming a complex which serves as a nucleation site for new microfilaments. The formins are, like actin, highly conserved proteins involved in actin remodelling, cellular morphology and coordination of microtubule and actin dynamics.

Recent actin antibody research has identified several cellular factors which modulate formin expression to affect actin nucleation and elongation. Formins with cellular functions apart from actin polymerization have also been discovered. Recent additions to the formin nucleator database include Cordon-Bleu, Cappuccino, Leiomodin and Spire. In addition, several proteins have been identified which stimulate ARP2/3 activity to affect actin nucleation and dynamics. These include WASH (the WASP and SCAR homologue); WHAMM (WASP homologue associated with actin, membranes and microtubules) and the junction-mediating regulatory protein JMY.

Actin antibody research continues to uncover new genetic facts about actin polymerization and the cytoskeleton. We at Novus Biologicals have an extensive antibody catalogue covering this area of research.

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The Akt Antibody and its Role in Cancer Research

Monday, May 9th, 2011

There are three human isoforms of the AKT gene, which plays a key role in several signalling pathways. Akt antibody studies have shown the Atk kinases to play a diverse number of roles within the cell, regulating angiogenesis, apoptosis, protein synthesis, intermediary metabolism and cellular differentiation. We at Novus Biologicals have a wide range of Akt products on our antibody database, targeting all three isoforms.

Akt antibody research has identified specific roles for the three isoforms of Akt. Akt2 plays an important role in insulin signalling, while Akt3 is thought to be involved with neuronal development. Akt1, the founding member of the family, is of major importance to cancer researchers. A key player in the PI3K/AKT/mTOR and several other pathways, Akt1 signalling promotes hypertrophy (growth) of skeletal muscle and other tissues, and promotes cell survival by inhibiting apoptotic processes.

Akt1 was originally identified as an oncogene in the AKT8 transforming retrovirus, and has since been shown to be critical to the growth and progression of a number of human neoplasms. It also plays an indirect role, acting on oncogenic signals resulting from mutations in tumour-suppressor genes and other oncogenes.

Today, the entire Akt antibody database is used in cancer research. Overexpression of Akt2 and Akt3 has been directly linked to the development of epithelial neoplasms, breast tumours, prostate cancer, ovarian cancer and skin cell melanomas. Researchers at the MORI Institute, Tufts University, are using insertional mutagenesis and other genetic techniques to probe the function of all three isoforms. Other groups are using Akt antibody products to develop antineoplastic drugs.

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How PARP Antibody Assays Aid Apoptosis Research

Friday, April 15th, 2011

The PARP (Poly(ADP-ribose) polymerase) protein is a zinc-dependant nuclear enzyme whose main role is to detect and repair DNA single-strand breaks (SSB). However, PARP antibody research has revealed there are at least 17 PARP proteins, which also play a major role in apoptosis (programmed cell death) and post-translational modification. We at Novus Biologicals have an extensive range of PARP antibody products in our antibody catalogue.

PARP is activated in response to metabolic, radiation or chemically-induced DNA SSBs. Once a break is detected, the enzyme binds to the DNA and begins synthesis of a poly ADP-ribose chain, or PAR, utilising NAD as a substrate. This is done in partnership with other repair proteins including DNA ligase III, DNA polymerase beta and the scaffolding protein XRCC1, resulting in a base excision repair. Once this is completed, PAR degradation takes place.

Recent PARP antibody studies have revealed PARP enzymes play an essential role in apoptosis, in a number of ways. Catalytic activity has been shown to be stimulated by the oligomerization of PARP-2 with PARP-1, which also plays a role in transcription by chromatin remodelling. Caspase 3 proteolytic cleavage of PARP is a key event in apoptosis.

Also, following DNA cleavage initiated by apoptotic enzymes, PARP can deplete cellular ATP to aid DNA repair; however, this also causes lysis and cell death. During DNA repair, overexpression of PARP can lead to cellular NAD-depletion, leading in turn to progressive ATP depletion, inhibition of glucose oxidation and necrotic cell death. PARP can also directly initiate apoptosis, and initiate expression of inflammatory proteins. Recently, the PARP antibody reagents in our antibody catalog have proven important to breast cancer research.

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ABCA1 Expression Down-regulated by SREBP microRNA

Friday, March 18th, 2011

The ABCA1 (ATP-binding cassette transporter-A1) gene encodes a transmembrane protein, which plays a major role in phospholipid homeostasis by regulating cholesterol efflux from the cell. ABCA1 antibody studies have shown ABCA1 expression is up/down regulated by the transcription factors LXR and SREBP2 respectively. Now, new evidence points to microRNA (mRNA) being integral to SREBP2 down-regulation of ABCA1. We at Novus Biologicals have a large number of LXR, SREBP2 and ABCA1 antibody products in our antibody catalogue.

ABCA1 is expressed on the Golgi body and plasma membrane. Expression is regulated by transcription factors in response to alterations in the cholesterol flux. Its role is to mediate transport of lipids between the two expression sites, and to moderate cholesterol and phospholipid efflux to the apo-A1 and apoE apolipoproteins, for HDL (high-density lipoprotein) formation. The protein is expressed in high levels in the liver, gut and adipose tissue.

SREBP-2 (sterol-regulatory-element-binding protein 2) controls cholesterol homeostasis by upregulation of genes involved in cholesterol synthesis and uptake, e.g. HMG-CoA, while LXR upregulates expression of ABCA1 and other cholesterol efflux genes. Oxysterols (cholesterol derivatives) inhibit SREBP2 activation whilst acting as LXR ligands. ABCA1 antibody studies conducted by J.Wang have suggested SREBP2 controls ABCA1 expression by maintaining a supply of oxysterol ligands for LXR.

Recently, miRNAs have been shown to play an important role in cholesterol homeostasis by post-transcriptional regulation of a number of lipid metabolism genes, with ABCA1 antibody studies demonstrating ABCA1 inhibition by miRNA action. A study conducted in 2010 showed inhibition was achieved by two miRNAs embedded in the SREBP2 host gene. This exciting development has opened new avenues of research for our antibody catalog.

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Caspase Antibody Study Shows Link to Heart Disease

Monday, February 28th, 2011

Caspase 3 is a member of the cysteine-aspartic acid protease family and an important mediator of apoptosis. Caspase 3 antibody reagents have been used in cancer, Alzheimer’s disease and stem cell research. A recent caspase 3 antibody ELISA study showed elevated levels of the p17 caspase 3 fragment were associated with myocardial infarction in humans. We at Novus Biologicals are one of the leading antibody suppliers of caspase products.

Caspase 3 is one of the effector group of caspases, initiating DNA fragmentation and chromatin condensation in apoptosis, via substrate cleavage following activation by either death ligand or mitochondrial action. It interacts with initiator caspases 8 and 9, and plays a predominant role in the cleavage of amyloid-beta 4A, which has been linked to neuronal cell death in Alzheimer’s patients. As well as its role in apoptosis, caspase 3 is now known to be important to normal brain cell development, and may be involved in the differentiation of embryonic and hematopoietic stem cells.

Research into acute Myocardial Infarction (AMI), has shown apoptosis of cardiac monocytes to follow development of infarcts in animal models. However, results have been uncertain in human patients. In January 2011, Mariela Agosto et al published a paper showing serum caspase 3 p17 fragments were elevated in patients with ST-segment elevation Myocardial Infarction (STEMI). STEMI has a high mortality risk, which can be reduced by reperfusion of the myocardium. However, injury can occur, which in animals leads to apoptosis – the end effector of which is p17 caspase 3.

Using p17 caspase 3 antibody ELISA techniques, Agosto was able to show a four-fold increase of p17 caspase 3 levels in patients undergoing treatment for STEMI, compared to healthy controls.

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Are ABCA1 Mutations a Risk Factor for Strokes?

Monday, February 21st, 2011

The ATP Binding Cassette Transporter (ABCA1) gene encodes the cholesterol regulatory efflux protein, which plays a key role in lipid metabolism. ABCA1 antibody products are an important part of any antibody catalog covering atherosclerosis disease research.

Atherosclerosis (narrowing of the arteries) is characterized by a build-up of fatty plaques, containing cholesterol, causing arteries to narrow. These plaques can then become ulcerated, causing blood clots to form. If this occurs in the carotid arteries the clots can travel to the brain, causing a stroke. In the general population, low plasma HDLC levels are well documented to increase the risk of coronary heart disease.

ABCA1 antibody studies in animal models have shown ABCA1 gene mutations increase the risk of atherosclerosis. Researchers also discovered that oxidation of LDL in the cells of the arterial wall is modulated by ABCA1. In atherosclerotic plaques, ABCA1 upregulation occurred, suggesting a link between ABCA1 expression and the formation of plaques. Results also suggested ABCA1 polymorphisms can affect lipid profiles, and that ABCA1 may play an essential role in regulating ApoA-I and ApoE levels in the brain.

In humans, a 2005 Hungarian study of stroke patients suggested two ABCA1 polymorphisms which may offer protection from strokes. However, a similar study by Pasdar et al in 2007 showed no significant effect – positive or negative – in four ABCA1polymorphisms, although they reported a change in serum lipid levels.

In 2009, P. Isoviita et al conducted CD36 and ABCA1 antibody assay studies on carotid plaques (CPs). The results suggested that an imbalance between lipid efflux and influx, represented by CD36 and ABCA1 levels, could lead to carotid plaque build-up, intraplaque hemorrhages and increased stroke risk. We at Novus Biologicals have an extensive antibody catalogue covering ABCA1 antibody research.

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