In this issue: Proteomics – Clinical Applications 7‐8/2008

In this issue of Proteomics – Clinical Applications you will find the following highlighted articles: Hi ho SELDI, away! That closing cry of the Lone Ranger meant that everything was under control. The bad guy was either dead or in jail, the good guy had his job or his ranch back. Here it means that O'Riordan et al. have begun to unearth some of the urinary proteome changes that result in chronic allograft nephropathy (CAN). Based on studies of 75 renal transplant patients and 20 healthy controls using surface enhanced laser desorption and ionization (SELDI), patients could be classified by stages. Advanced CAN associated proteins included α1‐microglobulin, β2 microglobulin, prealbumin, and endorepellin (the anti‐angiogenic C‐terminus of perlecan). Statistical analysis suggests that urinary endorepellin serves as a biomarker for advanced CAN. O'Riordan, E. et al., Proteomics 2008, 8 , 1025–1035. Contrast response prediction, detection: “First, do no harm” redux It is sometimes difficult to deal with the tradeoffs faced in medical practice…we may do harm while doing good. In this case, using a radio‐opaque contrast agent to determine the state of a child's heart in preparation for surgery may lead to acute kidney injury (AKI), requiring an extended stay, dialysis, or increased chance of death for the next 6 months to 5 years. Contrast‐induced nephropathy (CIN) is the third most frequent cause of hospital acquired AKI. Bennett et al. used proteomic tools (SELDI‐TOF‐MS) to examine urine for biomarkers that would predict possible difficulties and found two good candidates: a down‐regulated 41 amino acid variant of beta‐defensin‐1 and an up‐regulated protein of 4631 Da of unknown origin. Both predicted CIN before the procedure. At present, less toxic contrast agents are also less effective. Bennett, M. R. et al., Proteomics 2008, 8 , 1058–1064. Sugar, daddy! Regulation of glucose levels is a collaborative effort of the pancreas and kidneys. Excessive levels of the sugar lead to a variety of pathological conditions, including high levels of reactive oxygen species. So et al. have examined the changes that occur in protein expression in cultured kidney cell line HK‐2. They found high glucose caused twelve differential changes in HK‐2 cells, five of which were significant. Enolase 1 and triosephosphate isomerase are the two up‐regulated enzymes, while glyceraldehyde phosphate dehydrogenase, pyruvate dehydrogenase, and lactate dehydrogenase are down‐regulated. Mitochondrial ATP synthase subunit d is also affected by glucose levels. Knowing the names of some of the players in the diabetes game is a help, but much remains to be explored and explained before the “Case Closed” stamp is called for. So, E.‐J. et al., Proteomics 2008, 8 , 1118–1126.