Fabp3 as a Biomarker of Skeletal Muscle Toxicity in the Rat: Comparison with Conventional Biomarkers

Abstract

Fatty acid binding protein 3 (Fabp3) has been used as a serological biomarker of cardiac injury, but its utility as a preclinical biomarker of injury to skeletal muscle is not well described. Fabp3 concentrations were determined for tissues from Sprague-Dawley rats and found to occur at highest concentrations in cardiac muscle and in skeletal muscles containing an abundance of type I fibers, such as the soleus muscle. Soleus is also a primary site of skeletal muscle (SKM) injury caused by lipid-lowering peroxisome proliferator-activated receptor alpha (PPAR-alpha) agonists. In rats administered repeat doses of a PPAR-alpha agonist, the kinetics and amplitude of plasma concentrations of Fabp3 were consistent with plasma compound concentrations and histopathology findings of swollen, hyalinized, and fragmented muscle fibers with macrophage infiltration. Immunohistochemical detection of Fabp3 revealed focal depletion of Fabp3 protein from injured SKM fibers which is consistent with increased serum Fabp3 concentrations in treated rats. We then assessed the predictivity of serological Fabp3 for SKM necrosis in short duration toxicology studies. Rats were treated with various doses of 27 different compounds, and the predictivity of serological biomarkers was assessed relative to histology in individual rats and in treatment groups. Under these study conditions, Fabp3 was the most useful individual biomarker based on concordance, sensitivity, positive and negative predictive values, and false negative rate. In addition, the combination of Fabp3 and aspartate aminotransferase (AST) had greater diagnostic value than the conventional combination of creatine kinase-MM isoenzyme (CK) and AST.

Impact of different blood sampling techniques on plasma biomarkers for skeletal myopathy in conscious rats

“…In contrast, plasma AST, FABP3, Myl3 and miR-133a were drastically elevated after TMPD treatment and the extent of the change was similar in both techniques. The large signalto-noise ratios seen with these biomarkers regardless of sampling technique indicate their diagnostic accuracy in line with the previous work (Pritt et al, 2008;Tonomura et al, 2009;Tonomura et al, 2012;Laterza et al, 2009). The kinetics of these biomarkers were somewhat different; plasma CK-MM and FABP3 were drastically elevated 7 hr after the TMPD treatment, whereas plasma AST, Myl3 and miR-133 reached maximum at 24 hr after the TMPD treatment.…”

“…Thus, it is critical that investigators should consider the kinetics of each biomarker response to various types of compounds depending on their mode of action when interpreting results of the studies. Overall, combinational measurement of these biomarkers could supply useful information for detecting potential toxicity and target tissues for new chemical entities in nonclinical toxicological studies as several authors pointed out (Pritt et al, 2008;Tonomura et al, 2009;Tonomura et al, 2012).…”

“…Recently, fatty acid binding protein 3 (FABP3) and myosin light chain 3 (Myl3) have been introduced into the toxicological field as promising biomarkers for skeletal myopathy (Pritt et al, 2008;Tonomura et al, 2009Tonomura et al, , 2012. Additionally, muscle specific microRNAs (e.g., miR-133a) have also been suggested as useful and reliable biomarkers for skeletal muscle injury in experimental animals (Laterza et al, 2009;Mizuno et al, 2011).…”

Qualification of Cardiac Troponin I Concentration in Mouse Serum Using Isoproterenol and Implementation in Pharmacology Studies to Accelerate Drug Development

“…TOXICOLOGIC PATHOLOGY AST, CK, Fabp3, and cTnI AST activity and total CK activity in serum were analyzed using a Roche/Hitachi 917 automated analyzer (Indianapolis, IN) according to the manufacturer's protocol. Fabp3 concentration in serum was measured by a mouse/rat-specific ELISA (Cat# HK403 Hycult Biotechnology, Uden, the Netherlands) as previously described (Pritt et al 2008). Cardiac TnI concentration in serum was measured by a mouse-specific ELISA (Cat# 2010-1-HS, Life Diagnostics, Inc., West Chester, PA).…”

Toxic Myopathies

“…Such a biomarker would allow identification of patients at risk before rhabdomyolysis occurs and also obviate the need for statin discontinuation in patients whose symptoms are not due to myonecrosis. Several candidate biomarkers of skeletal muscle toxicity are under study, including troponin 1 [43], fatty acid-binding protein 3 [44], and 1-and 3-methyl histidine [45], but all of these are still in early preclinical testing and none has as yet advanced to rigorous clinical validation for statin-induced myonecrosis. An imaging biomarker that may have utility as a research tool is measurement of phosphocreatine exercise recovery kinetics using 31 P-magnetic resonance spectroscopy, which has been used to demonstrate prolonged metabolic recovery in patients after statin administration, indicating (secondary) impairment of mitochondrial oxidative function.…”