Infrared spectroscopy of dystrophic mdx mouse muscle tissue distinguishes among treatment groups

Methods and biomarkers for the diagnosis and prognosis of cancer and other diseases: towards personalized medicine

The rapid development of new diagnostic procedures, the mapping of the human genome, progress in mapping genetic polymorphisms, and recent advances in nucleic acid- and protein chip technologies are driving the development of personalized therapies. This breakthrough in medicine is expected to be achieved largely due to the implementation of "lab-on-the-chip" technology capable of performing hundreds, even thousands of biochemical, cellular and genetic tests on a single sample of blood or other body fluid. Focusing on a few disease-specific examples, this review discusses selected technologies and their combinations likely to be incorporated in the "lab-on-the-chip" and to provide rapid and versatile information about specific diseases entities. Focusing on breast cancer and after an overview of single-nucleotide polymorphism (SNP)-screening methodologies, we discuss the diagnostic and prognostic importance of SNPs. Next, using Duchenne muscular dystrophy (DMD) as an example, we provide a brief overview of powerful and innovative integration of traditional immuno-histochemistry techniques with advanced biophysical methods such as NMR-spectroscopy or Fourier-transformed infrared (FT-IR) spectroscopy. A brief overview of the challenges and opportunities provided by protein and aptamer microarrays follows. We conclude by highlighting novel and promising biochemical markers for the development of personalized treatment of cancer and other diseases: serum cytochrome c, cytokeratin-18 and -19 and their proteolytic fragments for the detection and quantitation of malignant tumor mass, tumor cell turn-over, inflammatory processes during hepatitis and Epstein-Barr virus (EBV)-induced hemophagocytic lymphohistiocytosis and apoptotic/necrotic cancer cell death.

Metabolic shifts and myocyte hypertrophy in deflazacort treatment of mdx mouse cardiomyopathy

We tested the hypothesis that treatment of mdx mouse muscular dystrophy with the glucocorticoid deflazacort prevents cardiomyopathic lesions and is accompanied by changes in metabolism and gene expression that reflect the improved tissue integrity. Cardiac muscle pathology, expression of alpha-cardiac myosin heavy chain, DNA synthesis, laminin, and basic fibroblast growth factor (bFGF) were examined to characterize dystrophy and changes with treatment. The potential of proton magnetic resonance spectroscopy (H-NMRS) to track cardiac dystrophy and deflazacort effects was also studied. Deflazacort (but not equipotent prednisone) reproducibly decreased lesion prevalence and severity. Treatment also produced cardiomyocyte hypertrophy and a 5.4-fold increase in alpha-cardiac myosin content. Expression of bFGF messenger RNA (mRNA), notable around lesions, rose 3.3-fold, and laminin expression rose 2.1-fold after deflazacort. Studies using H-NMRS showed a cardiac "signature" with less glycine and taurine than limb muscle or diaphragm and shifts with progression of dystrophy (distinct from normal aging) in many metabolites. Increased taurine, acetate, and succinate were present after 2 weeks of deflazacort treatment but were not present after 4 weeks. Although paired kinetic and functional studies of myocardium will be needed to determine the origin of such changes, these results demonstrate the potential application of H-NMRS to monitor clinical heart disease and treatment. In addition, the metabolic effects of deflazacort were substantial in preventing the progression of cardiomyopathy in mdx mice and included increased expression of protectant and stabilizing factors and hypertrophy of cardiac myocytes.

Nuclear magnetic resonance spectroscopy study of muscle growth, mdx dystrophy and glucocorticoid treatments: correlation with repair

Proton nuclear magnetic resonance spectroscopy (1H NMR) can be used to study skeletal muscle metabolism. The mdx mouse is a unique animal for studies of muscle regeneration, and models the disease of Duchenne muscular dystrophy (DMD). The goals of this study were to determine the potential of 1H NMR spectroscopy as an alternative to conventional histology in monitoring: (1) normal growth in control muscle and the progression of dystrophy in mdx muscle, and (2) beneficial treatments (glucocorticoids) on mdx dystrophy. Ex vivo 1H NMR spectra of limb and diaphragm muscles were obtained from different ages of control and mdx mice, and from mice which were treated with prednisone or deflazacort. Peaks with contributions from creatine, taurine and lipids were examined. Lower levels of taurine and creatine characterized predystrophy and active dystrophy intervals in mdx muscle compared to control. Levels of taurine increased with stabilization of the disease by repair. A measure of accumulated muscle repair, fiber centronucleation and many spectral peaks were highly and significantly correlated. Greater amounts of lipids were found in the diaphragm compared to limb spectra. Treatment of dystrophy, which improved muscle phenotype, resulted in greater levels of taurine and creatine, especially in the limb muscle. Therefore, 1H NMR differentially discriminates: (1) control and mdx muscle; (2) the progression of mdx dystrophy and developmental stages in normal growth; (3) mild and severe dystrophic phenotypes (diaphragm vs limb); and (4) changes associated with improved muscle phenotype and regeneration (due to treatment or injury). The results focus on monitoring muscle repair, not degeneration. We conclude that 1H NMR is a reliable tool in the objective investigation of muscle repair status during muscular dystrophy.