Novus Biologicals | Antibody News

Not everyone knows how antibodies influence animal life, so this article is, in part, a very brief introduction. Novus Biologicals offers a printed version of their Apoptosis Catalog that contains additional information on apoptotic mechanisms; email promotions@novusbio.com to get a copy.

Apoptosis is triggered by a variety of signals and takes place by one of several mechanisms. These involve cell surface receptors, cytokines, tumour necrosis factors, proteins such as Bcl-2, Bax and Apaf-1, the caspase cascade, and apoptosis-inducing factors.

Specific antibodies can assist in pinpointing exactly which factors and signals are involved in any particular situation.

Apoptosis is vital in the breakdown of early embryonic structures, so as to permit development and maturation. Without apoptosis, the caterpillar cannot metamorphose into the butterfly, the tadpole cannot lose its tail and neural synapses cannot form.

The detachment of the uterine endometrium at the start of menstruation involves apoptosis. Lymphocytes proliferating in response to an antigenic stimulus undergo apoptosis when this immune response is no longer required.

Apoptosis is also defensive. Virus-infected cells are set on the apoptotic path by cytotoxic T cells. Likewise, cells with damaged DNA are induced to undergo apoptosis by the p53 protein.

Defects in apoptosis occur in autoimmune disease. Mutation of one of the apoptosis genes results in autoimmune lymphoproliferative syndrome.

Some cancer cells can avoid apoptosis and continue their abnormal proliferation, sometimes due to the action of a cancer virus such as HPV or EBV. In contrast, the loss of CD4+ cells in AIDS is due to excessive apoptosis.

Apoptosis raises fascinating questions in fundamental research and questions of importance for understanding disease and developing new therapies. In its antibody catalog, Novus Biologicals offers investigators more than 5500 products of relevance to this research.

We have seen that antibody research can deliver progress in areas where other methods have not enjoyed such success.

Caspase 3 is primarily known as an effector molecule in apoptosis, the process of programmed cell death. However, a study by Jeyasuria et al (Biol. Reprod. 2009, 80(5) pp. 928-934) has found that caspase 3 may have a role in preventing excessive uterine contractions before pregnancy reaches term. This is essential to preventing premature labour. The authors used immunological techniques with a group of antibodies to demonstrate this phenomenon. Smooth muscle γ-actin is a protein found only in smooth muscle. Thus, antibody to smooth muscle γ-actin (ACTG2) from Novus Biologicals was chosen to identify caspase 3 action in the smooth muscle of the uterus.

On the basis of their results, the authors concluded that the elevated activity of caspase 3 seen in the pregnant mouse uterus is not associated with apoptosis.

Caspase 3 activity is maintained at a high level by progesterone (P4). It promotes cleavage of smooth muscle actins. Consequently, the contractile architecture of the uterus is maintained in a degraded state. This makes the uterus less capable of contracting during the course of the pregnancy.

As progesterone levels fall at the end of pregnancy, there is a parallel decrease in caspase 3 activity. The contractile architecture of the uterus is subsequently fully restored and the uterus becomes ready for the contractions of labour.

The Novus Biologicals antibody catalog offers a range of antibodies, including caspase 3 and its precursor to facilitate research into its apoptotic and non-apoptotic activities.

Autism is a condition which demands more research – even if some autistic people do not want their condition to be ‘cured’, most would like some of their symptoms to be alleviated.

Fatemi and colleagues (J Autism Dev Disord. 2009, 39(2) pp. 223–230) subjected brain tissue from autistic and control subjects to SDS-PAGE followed by Western blotting and incubation with antibodies to four GABA-A receptor subunits.

Levels of GABRB3, which was identified using an antibody from the Novus Biologicals antibody catalog, were decreased in the cerebellum and parietal cortex of autistic subjects. The cerebellum also showed decreased levels of GABRA1. The parietal cortex showed decreased levels of GABRA1, GABRA2 and GABRA3. Only GABRA1 was decreased in the frontal cortex of autistic subjects.

Autism has been associated with structural abnormalities in these same regions of the brain. It is thought that abnormalities in the cerebellum may cause motor system dysfunction found in autism. Defects of the parietal cortex could account for language problems, disturbed visuo-spatial integration and slowed attention shift. Frontal cortical abnormalities may lead to the linguistic, cognitive and emotional deficits typical of autism.

The authors suggest that the decrease in GABA-A receptor subunits may contribute to the development of these abnormalities. They cite the finding that GABRB3 knockout mice also show abnormalities. Moreover, on the basis of other data in the literature, they consider the gene for GABRB3 to show the greatest potential for identifying the genetic basis of autism.

This preliminary demonstration of changes in GABA-A receptor subunits opens the door for increased understanding of autism. Anti-GABA receptor antibodies will undoubtedly contribute to future studies.

Researchers can manipulate antibodies to yield very impressive research outcomes, which may prove highly relevant to the medical treatment of the future.

Severson et al (MBC 2009, 20(7) pp. 1916-1925) used antibodies, including monoclonal rabbit anti-JAM-A and monoclonal rabbit anti-β1 integrin from Novus Biologicals to investigate epithelial cell migration.

In a previous study, this team demonstrated that cell migration is regulated by junctional adhesion molecule A. JAM-A is a transmembrane protein in tight junctions, namely areas where membranes of adjacent cells join closely together. In epithelial cells, JAM-A is thought to decrease paracellular permeability and favour epithelial cell migration. These functions maintain the barrier function of intestinal epithelium. Barrier function is compromised in some intestinal diseases. Stress can cause further dysfunction. The net result is increased uptake of harmful toxins and antigens from the intestinal lumen, leading to further exacerbation. Greater understanding of the mechanisms maintaining intestinal barrier function may identify new therapeutic strategies in intestinal disease.

The study was performed in monolayers of a human epithelial colonic cell line and in isolated colonic epithelial cells from JAM-A-deficient and control mice. The results indicated that dimerisation of JAM-A acts as a signal to regulate epithelial cell migration. The dimers interact with Afadin and PDZ-GEF2 to activate the DNA-binding protein Rap1A. This in turn stabilises β1 integrin and thus regulates cell migration.

The authors state that further studies are required to establish the mechanism by which Rap1A stabilizes β1 integrin levels in epithelial cells. It may be that antibodies to both these substances, available from the Novus Biologicals antibody catalog, will contribute to this research.

Antibodies to beclin 1 may help elucidate the significance of this protein and its role in autophagy.

Autophagy is the lysosomal degradation of cell constituents. It occurs in malnutrition, enabling the body to recycle cell components to provide metabolic precursors. Autophagy is also involved in the response to pathogens and in other processes. Some aspects are summarised here.

Homozygous beclin 1-/- embryos from chimeric beclin 1+/- mice all died in early embryogenesis. This was considered to be due to defective visceral endoderm, in which beclin 1 is normally strongly expressed. Furthermore, the beclin 1+/- mice had a higher incidence of tumours (Yue et al, PNAS 2003, 100(25) pp. 15077-15082).

A review by Sun and Peng (Laboratory Medicine 2008, 39(5):287-290) emphasises the deletion of beclin 1 in 75% of human ovarian cancers, 50% of breast cancers and 40% of prostate cancers and its decreased expression in some other human cancers. The authors’ own studies lead them to conclude that beclin 1 could be a critical switch regulating the balance between autophagy and apoptosis. Thus beclin 1 might be a target for gene therapy of cancer.

Spencer et al. (J. Neurosci. 2009 29(43) pp. 13578-13588) injected a lentivirus expressing beclin 1 into the brains of alpha-synuclein transgenic mice, thereby improving cerebral pathology. They argue beclin 1 may be a novel therapeutic target for Parkinsonism and Lewy body disease.

Researchers interested in beclin 1 will find 57 different polyclonal and monoclonal anti-beclin antibodies in the Novus Biologicals antibody catalog, in addition to Beclin 2 antibodies. This impressive antibody catalog is a resource which has the potential to benefit the work of researchers involved in many spheres of ‘cutting edge’ health-related activity.

Treating cancer is a major health priority in western society. Coupled with attempts to alter unhealthy behaviour, it is hoped that better cancer treatment can reduce premature deaths.

Anti-APE1 mouse monoclonal antibodies from Novus Biologicals were antibodies used to investigate drug resistance in non-small cell lung carcinoma (Wang et al., Lung Cancer 2009, 65(3), pp. 298-304). Tumour drug resistance results in less successful chemotherapy.

Apurinic/apyrimidinic endonuclease (APE1) has a key role in the repair of DNA damage. By protecting cells from the genotoxic and cytotoxic effects of oxidising agents, APE1 counters the development of a number of pathologies.

Conversely, in the case of tumour cells, the protective effects of APE1 will have negative consequences if they result in the tumour having an increased capacity to resist anti-cancer treatment.

Wang and colleagues used anti-APE1 antibodies in immunohistochemical and Western blot studies to investigate APE1 protein expression in tumour samples from patients with non-small cell lung carcinoma. The tumours varied in their resistance to cisplatin chemotherapy. High levels of APE1 expression were seen in 83.3% of resistant tumours, but in only 8.3% of sensitive tumours. Low expression levels of APE1 correlated with longer overall survival and disease-free survival of the patients.

Further studies in a human lung adenocarcinoma cell line showed that cisplatin increased APE1 expression in these cells. Treatment of the cells with an adenoviral vector carrying APE1 siRNA (small interfering RNA) inhibited APE1 expression and increased cell sensitivity to cisplatin.

Anti-AGE antibodies are not the elixir of youth as their name might imply! They have nevertheless provided new information about Alzheimer’s disease, the major cause of dementia in old age.

Advanced glycation end products (AGE) are produced by glycation and oxidation reactions between sugars and free amino groups on proteins and amino acids. They are implicated in a wide range of pathologies. AGE can form in cooked foods. In addition, glycation reactions within the blood form endogenous AGE. High blood sugar levels favour endogenous AGE production.

Diabetes is a risk factor for Alzheimer’s. This motivated a study by Burdo et al (Neurobiol. Aging 2009, 30(12), pp. 1910-1917). The authors used anti-AGE antibodies from Novus Biologicals to detect AGE.

Firstly, they demonstrated synergistic interactions between glucose and beta amyloid peptide leading to increased AGE accumulation in cultured brain microvascular endothelial cells.

They then investigated the relationship between AGE accumulation and elevated blood glucose in transgenic mice expressing mutant human amyloid precursor protein and presenilin. These mice are a model for presymptomatic Alzheimer’s disease.

Mice that were made diabetic showed decreased cognitive functions compared to controls. This was associated with increased levels of AGE in cerebral microvessels. On the other hand, no amyloid plaques or tangles were apparent in the brains of these mice.

The role of diabetes in presymptomatic Alzheimer’s and early loss of cognitive function has thus been further elucidated with the aid of anti-AGE antibodies from Novus Biologicals. This has to be recognised as a meaningful advance in attempts to understand the connections between two conditions that have considerable impact on well being in contemporary society.