Thu, 21 Aug 2008 17:21:03 BST CiteULike: jyuh Pasquali http://www.citeulike.org/user/jyuh/author/Pasquali CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/jyuh/article/1594916 <i>Mol Cell Proteomics (7 July 2007)</i><br /><br />Prior work employing lipid-based affinity matrices has been used to investigate distinct sets of lipid-binding proteins and one series of experiments has proven successful in mammalian cells for their proteome-wide identification. However, most lipid-based proteomics screens require scaled up sample preparation, are often composed of multiple cell types and are not adapted for simultaneous signal transduction studies. Herein, we provide a chemical proteomics strategy that uses cleavable lipid "baits" with broad applicability to diverse biological samples. The novel baits were designed to avoid preparative steps in order to allow functional proteomics studies when biological source is a limiting factor. This makes this experimental strategy applicable to virtually any primary cell type. Validation of the chemical baits was first confirmed by the selective isolation of several known endogenous PI3K signaling proteins using primary bone marrow-derived macrophages. The use of this technique for cellular proteomics and MS/MS analysis was then demonstrated by the identification of known and potential novel lipid-binding protein, which was confirmed in vitro for several by direct lipid-protein interactions. Further to the identification, the method is also compatible with subsequent signal transduction studies, notably for protein kinase profiling of the isolated lipid-bound protein complexes. Taken together, this integration of minimal scale proteomics, lipid chemistry and activity-based readouts provides a significant advancement in the ability to identify and study the lipid-proteome of single, relevant cell types. A chemical proteomics approach to pi3k signaling in macrophages. Christian Pasquali Dominique Bertschy-Meier Christian Chabert Marie-Laure Curchod Christian Arod Randy Booth Karl Mechtler Francis Vilbois Ioannis Xenoarios Colin G Ferguson Glenn D Prestwich Montserrat Camps Christian Rommel doi:10.1074/mcp.T600066-MCP200 Mol Cell Proteomics (7 July 2007) 2007-08-26T14:39:54-00:00 2007 Mol Cell Proteomics 1535-9476 no-tag http://www.citeulike.org/user/jyuh/article/1512752 <i>Biomed Pharmacother, Vol. 61, No. 1. (January 2007), pp. 86-90.</i><br /><br />Epidemiological data suggest an association between kidney stones and some features of metabolic syndrome such as an overweight condition, arterial hypertension or glucose intolerance. However, mechanisms remain to be elucidated. This study aimed to evaluate insulin resistance, as assessed by homeostasis model assessment (HOMA-IR), and urine composition analysis in patients affected by calcium nephrolithiasis. A cohort of 61 (38 male, 29-57 years of age) non-diabetic calcium stone formers was studied. Data about body mass index, arterial blood pressure, serum biochemistry including parathyroid hormone and calcitriol were recorded in all the patients; fasting glucose and insulin were determined to calculate HOMA-IR value and accordingly the patients were grouped into tertiles. Urine pH and urinary excretion of calcium, citrate, phosphate, oxalate, uric acid, urea and creatinine were measured on 24h urine samples. Patients of the highest HOMA-IR tertile showed lower urine citrate levels than patients of the lowest HOMA-IR tertile (475+/-243 vs. 630+/-187 mg/24h, p<0.05), whereas no difference was detected as far as urinary oxalate, calcium, uric acid, phosphate, and urine pH and urine volume output were concerned. HOMA-IR values were positively related to uric acid serum levels (r=0.31, p<0.05) and negatively to urinary citrate excretion (r=-0.26, p<0.05). Hypocitraturic patients showed higher levels of HOMA-IR than normocitraturic ones (3.03+/-0.92 vs. 2.25+/-1.19, p<0.05). This study shows that a higher level of insulin resistance is associated with lower urinary citrate excretion, and that hypocitraturic patients show a greater insulin resistance than normocitraturic calcium stone formers. This may be related to changes in citrate, Na(+)-K(+) and H(+) renal tubule transports, which have been described in insulin resistance. In conclusion, insulin resistance may contribute to an increased risk of calcium stone formation by lowering urinary citrate excretion. This finding suggests the need for a careful metabolic assessment in patients known to form calcium stones in order to ensure stone recurrence prevention and cardiovascular protection. Insulin resistance and low urinary citrate excretion in calcium stone formers. A Cupisti M Meola C D'Alessandro G Bernabini E Pasquali A Carpi G Barsotti doi:10.1016/j.biopha.2006.09.012 Biomed Pharmacother, Vol. 61, No. 1. (January 2007), pp. 86-90. 2007-07-30T12:40:35-00:00 2007 Biomed Pharmacother 0753-3322 61 1 86 90 no-tag