Cover Picture: Proteomics – Clinical Applications 9/09

Abstract

AbstractThe kidney knowsBiomarkers hold the promise of being able to supply a broad spectrum of information: diagnostic, prospective, status/progress, toxicity, and these are just the obvious topics. How do we discover/release this information quickly and accurately? Mischak et al. developed a protocol for detection of nephrotoxicity after administration of cis‐Platin. Their experimental method involved the combination of capillary electrophoresis and electrospray ionization with TOF‐MS. Peaks were carefully screened statistically before analysis for discrimination capability in support vector machine software. The rat model statistics were very tight and yielded 34 distinguishing peptides. Human urine results cannot be expected to be as well clustered due to differences in diet, exercise, sleep and other factors but the authors argue that the markers should make a useful set of indicators for preliminary work on potential human drugs.Mischak, H. et al., Proteomics Clin. Appl. 2009, 3, 1062–1071.Can you say “Obese adipose secretory proteins” three times fast?If you can't, at least your tongue needs more exercise. It's more likely that all of you should get up out of the easy chair and chase your tongue around the block several times a day. It has been estimated that over 65% of the American population is overweight and at risk for insulin resistance, type 2 (adult onset) diabetes, and cardiovascular diseases. Managing the body's energy budget is in large part the responsibility of the adipose tissue both as a fat storage organ and as an endocrine source of a number of adipokines, including leptin, resistin and aponectin as well as low levels of inflammatory cytokines. In this study, Chen et al. looked at the response of the secretory cells to thiazolidindiones (TZD) using 1‐ and 2‐D LC‐MS/MS, and cDNA microarrays. Only fresh adipocytes and S‐V cells were used.Chen, X. et al., Proteomics Clin. Appl. 2009, 3, 1099–1111.The ghost of organs pastWhen is a kidney not a kidney? When it's a ghost that makes marker peak heights continue to grow or shrink for several months after removal of a diseased kidney or a living donor organ. Some more information: Sim et al. started out to find urinary biomarkers for renal cell carcinomas using urine samples that were prospectively collected for this purpose. Samples were collected pre‐ and post‐nephrectomy for each kidney. The researchers noted that 32 peaks from SELDI CM10‐ and 33 peaks from IMAC‐Cu‐chips were longitudinally differentially expressed. Differences ranged from less than 2‐fold to nearly 1000‐fold. (When this latter point was removed, other data looked much better.) Sample concentrations were normalized to creatinine levels, but caution must be used considering that the patients have abnormal kidney functions. A whole series of questions are raised by the authors that should be examined carefully by proteomics researchers and statisticians.Sim, S. H. et al., Proteomics Clin. Appl. 2009, 3, 1112–1122.