Fig 2: Changes in protein abundance induced by diabetes implicated in KEGG sulphur metabolism pathway and H2S production. (A) The proteins involved in sulphate activation and degradation, in clearance and H2S endogenous production are separately represented. Note that the following enzymes are up-regulated in diabetic kidney of double transgenic (dTg) samples vs wild-type (WT) renal homogenates: Papss2 (by ~1.7-fold, P = .001), Sqrdl (by ~1.9-fold, P = .001), Tst (by ~1.8-fold, P = .001), Suox (by ~1.7-fold, P = .001), Ethe1 (by ~1.3-fold, P = .001), Cth (by ~1.7-fold, P = .001). In contrast, decreased abundance was detected for four enzymes (Bpnt1 by ~1.6-fold, P = .001; Cbs by ~1.6-fold, P = .001; Mpst by ~1.3-fold, P = .001 and Dao by ~2.9-fold, P = .001) induced by the transgenic intervention leading towards diabetes. Dashed lines represent the 1.5-fold regulation factor over the control samples. (B) Validation by Western blot of some protein markers identified by mass spectrometry: cystathionine ß-synthase (Cbs), sulphite oxidase, mitochondrial (Suox) and thiosulphate sulphurtransferase (Tst). Representative immunoblots and densitometric analysis for each enzyme are shown. Statistical analysis was made using Student's t test, and the results are expressed as means ± SD; *P < .05; **P < .01; ***P < .01. (C) Table display the references and main functions of enzyme involved in sulphur metabolism identified by the proteomic results. Papps2: bifunctional 3'-phosphoadenosine 5'-phosphosulphate synthase 2, Sqrdl: sulphidequinoneoxido reductase, Ethe1: protein Ethe1_mitochondrial; Cth: cystathionine ?-lyase; Bpnt1: 3(2)5 bisphosphate nucleotidase 1, Mpst: 3-mercaptopyruvate sulphur transferase; Dao: D-amino acid oxidase