Effects of a single subanesthetic dose of esketamine on postoperative subthreshold depressive symptoms in patients undergoing unilateral modified radical mastectomy: a randomised, controlled, double-blind trial.

BACKGROUND: Breast cancer is the most common malignant tumor in females worldwide. During disease development, breast cancer patients suffer anxious and depressed, which may lead to worse quality of life or even higher mortality. Esketamine has been regarded as an antidepressant in breast cancer patients with mild or moderate depression. Here, we wonder whether the administration of esketamine could reduce the postoperative depressive symptom score of breast cancer patients who have no preoperative depression. METHODS: A total of 64 patients treated with unilateral modified radical mastectomy were randomly divided into an experimental group (esketamine group, Group E) and a control group (Group C), with 32 cases in each one. After anesthesia induction, Group C received 0.2 ml/kg of normal saline intravenously and Group E was administered 0.2 mg/kg intravenous esketamine. The primary outcome was the Patient Health Questionnaire-9 (PHQ-9) scores. The secondary outcomes included the Visual Analogue Scale (VAS) scores for pain, inflammatory markers, perioperative-related indicators, and the incidence of postoperative delirium, nausea and vomiting. RESULTS: The PHQ-9 score on postoperative day (POD) 1 in Group E declined from the preoperative level, while the score in Group C was higher than before, and the former was far lower than the latter (P = 0.047). There is no statistically significant difference in PHQ-9 scores between Group E and Group C on POD 3, 7, and 30. Moreover, the postoperative leukocyte level of Group E was higher than that of Group C, and the difference was statistically significant (P = 0.030). CONCLUSIONS: A single subanesthetic dose of esketamine can result in lower postoperative score on subthreshold depressive symptoms compared to the Group C on POD 1, without increasing the occurrence of postoperative adverse reactions. TRIAL REGISTRATION: Registration number: Chinese Clinical Trial Registry ChiCTR2200057028. Date of registration: 26/02/2022.

Purification and characterization of a novel metalloprotease from fruiting bodies of Oudemansiella radicata.

In this study, a 39-kDa metalloprotease was purified from a rare edible mushroom with health-promoting activities, Oudemansiella radicata, using a purification protocol which entailed anion exchange chromatography on DEAE-cellulose and Q-Sepharose columns and gel filtration by fast protein liquid chromatography on a Superdex 75 column. Some peptide sequences were obtained by LC-MS/MS analysis and one of the sequences, DAWIQADVNR, manifested 90% identity to Coprinopsis cinerea metalloprotease. The optimal reaction pH and temperature for Oudemansiella radicata protease were pH 7.0 and 50°C, respectively. The protease was purified 79-fold and demonstrated a specific protease activity of 2.42 U/mg. The Km of the purified protease for the casein substrate was 0.65 mg/mL at pH 7.0 and 50°C. The activity of the protease was inhibited by Cd2+, Hg2+, Cu2+, Pb2+ and Fe3+ ions, but was enhanced by K+, Mn2+ and Fe2+ ions. The marked suppression of the protease activity by EDTA indicates that the protease is a metalloprotease.

Metabolomic analysis of the salt-sensitive mutants reveals changes in amino acid and fatty acid composition important to long-term salt stress in Synechocystis sp. PCC 6803.

Early studies in cyanobacteria have found that few genes induced by short-term salt shock (15-60 min) display a stable induction in the long-term (>1 day) salt-acclimated cells; meanwhile, most of the genes responsive to long-term salt stress were different from those by short-term salt shock, suggesting that different regulatory mechanisms may be involved for short-term and long-term salt stress responses. In our previous work using the model cyanobacterium Synechocystis sp. PCC 6803, sll1734 encoding CO2 uptake-related protein (CupA) and three genes encoding hypothetical proteins (i.e., ssr3402, slr1339, and ssr1853) were found induced significantly after a 3-day salt stress, and the corresponding gene knockout mutants were found salt sensitive. To further decipher the mechanisms that these genes may be involved, in this study, we performed a comparative metabolomic analysis of the wild-type Synechocystis and the four salt-sensitive mutants using a gas chromatography-mass spectrometry (GC-MS) approach. A metabolomic data set that consisted of 60 chemically classified metabolites was then subjected to a weighted correlation network analysis (WGCNA) to identify the metabolic modules and hub metabolites specifically related to each of the salt-stressed mutants. The results showed that two, one, zero, and two metabolic modules were identified specifically associated with the knockout events of sll1734, ssr3402, slr1339, and ssr1853, respectively. The mutant-associated modules included metabolites such as lysine and palmitic acid, suggesting that amino acid and fatty acid metabolisms are among the key protection mechanisms against long-term salt stresses in Synechocystis. The metabolomic results were further confirmed by quantitative reverse-transcription PCR analysis, which showed the upregulation of lysine and fatty acid synthesis-related genes. The study provided new insights on metabolic networks involved in long-term salt stress response in Synechocystis.

Complementary iTRAQ proteomics and RNA-seq transcriptomics reveal multiple levels of regulation in response to nitrogen starvation in Synechocystis sp. PCC 6803.

Sequential adaptation to environmental stress needs complex regulation at different cellular levels in cyanobacteria. To uncover the regulatory mechanism in response to nitrogen starvation, we investigated the genome-wide correlation between protein abundance and gene expression in a model cyanobacterium Synechocystis sp. PCC 6803 using complementary quantitative iTRAQ proteomics and RNA-seq transcriptomics. Consistent with the cell growth inhibition, proteomic analysis indicated phase-dependent down-regulation of proteins related to nitrogen metabolism, ribosome complexes, glycolysis pathway and tricarboxylic acid (TCA) cycles by nitrogen starvation. Transcriptomic analysis also showed that genes related to "Photosynthesis", "Protein synthesis" and "Energy metabolism" were significantly down-regulated by nitrogen starvation. Interestingly, the concordance between protein abundances and their corresponding mRNAs exhibited a functional categories-dependent pattern, with some categories, such as "Protein synthesis" and "Energy metabolism", having a relatively high correlation, while others even with numerous discordant changes in protein-mRNA pairs, indicated divergent regulation of transcriptional and post-transcriptional processes. In particular, an increased abundance of proteins related to "Photosynthesis" upon nitrogen starvation was found to be reversely correlated with the down-regulation of their corresponding mRNAs. In addition, two metabolic modules highly correlated with nitrogen starvation were identified by a co-expression network analysis, and were found to contain mostly photosynthetic proteins and hypothetical proteins, respectively. We further confirmed the involvement of the photosynthetic genes in nitrogen starvation tolerance by constructing and analyzing the psbV gene deletion mutant.

Integrated proteomic and transcriptomic analysis reveals novel genes and regulatory mechanisms involved in salt stress responses in Synechocystis sp. PCC 6803.

Salt stress is a common stress that limits growth and productivity of photosynthetic microbes in natural environments. Although cellular responses of a model cyanobacterium Synechocystis sp. PCC6803 to high and changing salt concentration have been studied, it remains undefined of the gene components and their regulation in the long-term salt acclimation networks. In this study, we performed an integrated study coupling a quantitative iTRAQ-LC-MS/MS proteomics and a next-generation sequencing-based RNA-seq transcriptomics on Synechocystis under salt stress for an extended period of time. Comparative quantification of protein abundances led to the identification of 68 and 108 proteins differentially regulated by salt treatment at 24 and 48 h, respectively. RNA-seq transcriptomic analysis showed that genes involved in energy metabolism and protein synthesis, and genes encoding hypothetical proteins responded to salt stress in a phase-dependent pattern. Notably, a gene encoding CO2-uptake-related protein (CupA) and three genes encoding hypothetical proteins were induced significantly at either transcript or protein level after long-term salt stress. Gene knockout and comparative growth analysis demonstrated that these four genes were involved in salt tolerance in Synechocystis. In addition, a complementary proteome and transcriptome analysis showed that concordance between protein abundances and their corresponding mRNAs varied significantly between various gene-protein pairs, indicating divergent regulation of transcriptional and post-transcriptional processes during salt stress adaptation in Synechocystis. The study provided new insights on genes and regulatory mechanism involved in salt stress response in Synechocystis.