Scientists at the Spinal Muscular Atrophy (SMA) Foundation, New York, and several US-based pharmaceutical companies have developed a sandwich enzyme-linked immunosorbent assay (ELISA) that measures the level of survival motor neuron (SMN) protein in the blood. In the developmental process the researchers tested a selection of antibodies from several companies including Proteintech, but found our SMN antibody 11708-1-AP, “had [a] 4-fold greater reactance to the protein standard” than the others tested. This previous blog post sheds more light on why this might be the case.
A deletion or mutational inactivation of the SMN1 gene causes the SMA disease, a progressive neuromuscular condition. The disease leads to the degeneration of alpha motor neurons in the anterior horn of the spinal cord and atrophy of the musculature due to denervation.
As well as SMN1, humans also have a “back-up” copy of the gene: the highly similar SMN2, though the amount of functional protein produced by SMN2 is approximately 70 to 90% less than SMN1. The difference between the two SMN genes is one base: a C to T replacement in exon 7 of SMN2. This small alteration promotes an alternative splicing pattern that excludes exon 7 from the resulting protein, an unstable, but partially functional truncated SMNΔ7. There are several forms of SMA which vary in severity. Patients with the milder forms of SMA tend to have higher copies of the SMN2 gene, though SMN2 can never compensate for SMN1 fully. Yet there is hope; there are a number of potential therapies under evaluation as potential treatments for SMA. Despite this fact however, there has been a critical lack in the development of methods to evaluate SMN-targeting therapies, particulary those therapies that upregulate SMN protein. To this end, the SMA foundation researchers set out to rectify the lack of SMN diagnostics, and with the help of our SMN antibody 11708-1-AP, have succeeded in developing a rapid assay that reliably and quantitatively detects SMN in both healthy and SMA subject’s blood samples. The results were able to show a 90% reduction in SMN protein compared to normal test subjects. Encouragingly, the researchers conclude that their newly developed SMN ELISA, “has general translational applicability to both preclinical and clinical research efforts.” Heartening news indeed!
You can also read about our other SMN antibody, a mouse monoclonal version, here.