title: Quantification of gene expression after painful nerve injury: validation of optimal reference genes.
abstract: Stably expressed housekeeping genes (HKGs) are necessary for standardization of transcript measurement by quantitative real-time polymerase chain reaction (qRT-PCR). Peripheral nerve injury disrupts expression of numerous genes in sensory neurons, but the stability of conventional HKGs has not been tested in this context. We examined the stability of candidate HKGs during nerve injury, including the commonly used 18S ribosomal RNA, β-tubulin I and β-tubulin III, actin, glyceraldehyde 3-phosphate dehydrogenase (GAPDH) and hypoxanthine phosphoribosyltransferase 1 (HPRT1), and mitogen-activated protein kinase 6 (MAPK6). Total RNA for cDNA synthesis was isolated from dorsal root ganglia of rats at 3, 7, and 21 days following either skin incision alone or spinal nerve ligation, after which the axotomized and adjacent ganglia were analyzed separately. Relative stability of HKGs was determined using statistical algorithms geNorm and NormFinder. Both analyses identified MAPK6 and GAPDH as the two most stable HKGs for normalizing gene expression for qRT-PCR analysis in the context of peripheral nerve injury. Our findings indicate that a prior analysis of HKG expression levels is important for accurate normalization of gene expression in models of nerve injury.
authors.affiliation: Department of Anesthesiology, Medical College of Wisconsin, Milwaukee, WI 53226, USA. mbangaru@mcw.edu
authors.forename: Madhavi Latha Yadav
authors.initials: ML
authors.lastname: Bangaru
authors.forename: Frank
authors.initials: F
authors.lastname: Park
authors.forename: Andy
authors.initials: A
authors.lastname: Hudmon
authors.forename: J Bruce
authors.initials: JB
authors.lastname: McCallum
authors.forename: Quinn H
authors.initials: QH
authors.lastname: Hogan
mesh_terms: D000818:Animals; D004195:Disease Models, Animal; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D018390:Gene Targeting; D020043:Genes, Essential / Q000235:genetics; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics; D048053:Mitogen-Activated Protein Kinase 6 / Q000235:genetics; D009437:Neuralgia / Q000201:enzymology / Q000235:genetics*; D011506:Proteins / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D012015:Reference Standards; D011984:Sensory Receptor Cells / Q000201:enzymology / Q000502:physiology*; D000071737:Stromal Interaction Molecule 1
chemical_list: D008562:Membrane Glycoproteins; D011506:Proteins; C518857:Stim1 protein, rat; D000071737:Stromal Interaction Molecule 1; C546203:TUB protein, rat; D048053:Mitogen-Activated Protein Kinase 6