Regulation of protein function through oxidative modification has emerged as an important molecular mechanism modulating various biological processes. Here, we report a proteomic study of redox-sensitive proteins in Arabidopsis cells subjected to H2O2 treatment. Four gel-based approaches were employed, leading to the identification of four partially overlapping sets of proteins whose thiols underwent oxidative modification in the H2O2-treated cells. Using a method based on differential labeling of thiols followed by immunoprecipitation and Western blotting, five of the six selected putative redox-sensitive proteins were confirmed to undergo oxidative modification following the oxidant treatment in Arabidopsis leaves. Another method, which is based on differential labeling of thiols coupled with protein electrophoretic mobility shift assay, was adopted to reveal that one of the H2O2-sensitive proteins, a homologue of cytokine-induced apoptosis inhibitor 1 (AtCIAPIN1), also underwent oxidative modification in Arabidopsis leaves after treatments with salicylic acid or the peptide elicitor flg22, two inducers of defense signaling. The redox-sensitive proteins identified from the proteomic study are involved in various biological processes such as metabolism, the antioxidant system, protein biosynthesis and processing, and cytoskeleton organization. The identification of novel redox-sensitive proteins will be helpful toward understanding of cellular components or pathways previously unknown to be redox-regulated.

BackgroundTo estimate the prognostic value of inflammatory markers in patients with laryngeal squamous cell carcinoma (LSCC).MethodsA total of 361 resected LSCC patients were included. The preoperative and postoperative neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio (MLR), alkaline phosphatase (ALP) and l actate dehydrogenase (LDH) were assessed. The Kaplan-Meier survival analysis and Cox regression analysis were conducted on overall survival (OS) and progression-free survival (PFS).ResultsBoth Kaplan-Meier analysis and univariate analysis demonstrated significant prognostic value of preoperative and postoperative NLR, PLR and MLR. However, only preoperative ALP was predictive of OS and PFS, and LDH failed to be predictor of OS and PFS. The multivariate analysis showed that preoperative NLR (OS: HR = 1.64, 95%CI: 1.06–2.54, p = 0.026; PFS: HR = 1.52, 95%CI: 1.04–2.23, p = 0.029) and postoperative MLR (OS: HR = 2.02, 95%CI: 1.29–3.14, p = 0.002; PFS: HR = 1.57, 95%CI: 1.05–2.34, p = 0.026) were independently related with survival.ConclusionsThe elevated preoperative NLR, PLR, MLR and ALP were significantly associated with worse survival and cancer progression. The preoperative NLR and postoperative MLR might be independent prognostic markers of OS and PFS in LSCC patients undergoing surgical resection.Electronic supplementary materialThe online version of this article (10.1186/s12885-018-4730-x) contains supplementary material, which is available to authorized users.

SUMMARYAtNUDT7 was reported to be a negative regulator of EDS1-mediated immunity in Arabidopsis. However, the underlying molecular and genetic mechanism of the AtNUDT7-regulated defense pathway remains elusive. Here we report that AtNUDT7 and its closest paralog AtNUDT6 function as novel negative regulators of SNC1, a TIR-NB-LRR-type R gene. SNC1 is upregulated at transcriptional and possibly post-transcriptional levels in nudt6-2 nudt7. The nudt6-2 nudt7 double mutant exhibits autoimmune phenotypes that are modulated by temperature and fully dependent on EDS1. The nudt6-2 nudt7 mutation causes EDS1 nuclear accumulation shortly after the establishment of autoimmunity caused by the temperature shift. We found that a low ammonium/nitrate ratio in growth media leads to a higher level of nitrite-dependent nitric oxide (NO) production in nudt6-2 nudt7, and NO acts in a positive feedback loop with EDS1 to promote the autoimmunity. The low ammonium/nitrate ratio also enhances autoimmunity in snc1-1 and cpr1, two other autoimmune mutants in Arabidopsis. Our study indicates that Arabidopsis senses the ammonium/nitrate ratio as an input signal to determine the amplitude of the EDS1-mediated defense response, probably through the modulation of NO production.