Leucine Rich Repeat-containing Protein LRG
Detection of LRG protein enables biomedical research
Leucine-rich alpha 2-glycoprotein 1 (known as LRG1 or LRG) contains a leucine rich repeat domain and was first sequenced in 1985. Although LRG is the first leucine rich repeat domain-containing protein to have been identified, its biological function is still under active investigation. LRG is expressed in brain tissue and cerebrospinal fluid, and expression of LRG is induced by inflammation. Several studies suggest that LRG protein may be a useful biomarker for disease states including idiopathic normal pressure hydrocephalus (INPH), biliary tract cancer, Parkinson's disease with dementia (PDD), and progressive supranuclear palsy (PSP). To support research on LRG, we offer anti-LRG antibody reagents and LRG ELISA kits.
LRG antibody and LRG ELISA kit products
Anti-LRG antibody products1 allow detection of the leucine rich repeat-containing LRG protein by Western blot or immunohistochemistry. LRG ELISA kits enable quantification of LRG protein in serum, EDTA plasma, urine, or cerebrospinal fluid from human, mouse, or rat in research2 studies.
|28069A||WB, IHC||Polyclonal Ab against rat LRG1 synthetic peptide.|
|28085A||WB, IHC||Polyclonal Ab raised against synthetic peptide corresponding to C-terminal region of human LRG1.|
|27769A||ELISA||Specific quantitation of human LRG1 in serum, EDTA plasma, urine, or CSF. Sensitivity: 0.17 ng/mL|
|27770A||ELISA||Specific quantitation of rat LRG1 in serum, EDTA plasma, urine, or CSF. Sensitivity: 1.68 ng/mL|
|27785A||ELISA||Specific quantitation of mouse LRG1 in serum, EDTA plasma, urine, or CSF. Sensitivity: 0.06 ng/mL|
1 Offered in partnership with IBL Co., Ltd., Japan. References listed below cite IBL or Immuno-Biological Laboratories as the kit manufacturer.
2 Products sold by Clontech Laboratories are for Research Use Only. Not for use in Diagnostic Procedures.
3 WB, Western Blot; IHC, Immunohistochemistry; ELISA, Enzyme-linked Immunosorbant Assay; CSF, cerebrospinal fluid.
|Figure 1. Detection of LRG protein by Western blot using LRG1 antibodies. Rat LRG expressed in a CHO cell line is analyzed using anti-rat LRG polyclonal antibodies.|
|Figure 2. Immunohistochemistry using LRG antibody on cerebral tissue. Anti-rat LRG polyclonal antibodies were used for immunohistochemistry, staining cilia of ependymal cells and choroid plexus cells.|
LRG and idiopathic normal pressure hydrocephalus (INPH)
- Nakajima, M., et al. (2012) Brain localization of leucine-rich alpha2-glycoprotein and its role. Acta Neurochirurgica Supplementum 113:97.
While examining the expression of LRG protein in cerebral tissue using histological sections of autopsied brain specimens from ten human subjects, the authors found expression of LRG throughout the entire brain, with particularly high expression in the deep cerebral cortex. By assessing expression of LRG protein relative to age of the subject, the researchers concluded that LRG expression in resident astrocytes increased with age. Antibodies to human LRG were used.
- Li, X., et al. (2006) Analysis of potential diagnostic biomarkers in cerebrospinal fluid of idiopathic normal pressure hydrocephalus by proteomics. Acta Neurochir (Wien). 148(8):859.
In an effort to identify potential biomarkers for idiopathic normal pressure hydrocephalus (INPH), researchers compared the proteome of cerebrospinal fluid from INPH patients and controls. LRG protein was found to be elevated in samples from INPH patients. Subsequently, an LRG ELISA was used to quantify LRG in CSF samples of diseased and healthy individuals. The authors suggested that LRG be further evaluated for use in the identification of CSF shunting occurring in INPH.
LRG and Biliary Tract Cancer (BTC)
- Sandanayake, N.S., et al. (2011) A combination of serum leucine-rich alpha-2-glycoprotein 1, CA19-9 and interleukin-6 differentiate biliary tract cancer from benign biliary strictures. Br J Cancer. 105(9): 1370.
Two conditions, cholangiocarcinoma (CCA) and gallbladder carcinoma, are often grouped together and termed biliary tract cancer (BTC). To identify better biomarker candidates for these disorders, the authors performed proteomic profiling of immunodepleted serum samples collected from patients with BTC, primary sclerosing cholangitis (PSC), immunoglobulin G4-associated cholangitis and healthy volunteers. LRG1 was identified as a potential biomarker for BTC, and levels of LRG1 were further assessed using the LRG ELISA kit.
LRG and neurodegenerative disease
- Miyajima, M., et al. (2013) Leucine-rich alpha 2-glycoprotein is a novel biomarker of neurodegenerative disease in human cerebrospinal fluid and causes neurodegeneration in mouse cerebral cortex. PLoS ONE 8(9): e74453.
To assess the role of LRG in aging and neurodegenerative disease, the authors used the human LRG ELISA assay to quantify LRG concentration in cerebrospinal fluid samples and performed immunohistochemistry on post-mortem cerebral cortex samples. The level of human LRG in CSF samples of patients with Parkinson's disease with dementia or progressive supranuclear palsy was found to be higher than that of LRG levels in CSF samples of healthy patients or individuals with other neurodegenerative diseases. The authors suggested that LRG be further studied for use as a biomarker.