iTRAQ-based differential proteomic analysis of the brains in a rat model of delayedcarbon monoxide encephalopathy

Effect and molecular mechanism of Sulforaphane alleviates brain damage caused by acute carbon monoxide poisoning:Network pharmacology analysis, molecular docking, and experimental evidence

Sulforaphane (SFN) has attracted much attention due to its ability on antioxidant, anti-inflammatory, and anti-apoptotic properties, while its functional targets and underlying mechanism of action on brain injury caused by acute carbon monoxide poisoning (ACOP) have not been fully elucidated. Herein, we used a systematic network pharmacology approach to explore the mechanism of SFN in the treatment of brain damage after ACOP. In this study, the results of network pharmacology demonstrated that there were a total of 81 effective target genes of SFN and 36 drug-disease targets, which were strongly in connection with autophagy-animal signaling pathway, drug metabolism, and transcription disorders in cancer. Upon the further biological function and KEGG signaling pathway enrichment analysis, a large number of them were involved in neuronal death, reactive oxygen metabolic processes and immune functions. Moreover, based on the results of bioinformatics prediction associated with multiple potential targets and pathways, the AMP-activated protein kinase (AMPK) signaling pathway was selected to elucidate the molecular mechanism of SFN in the treatment of brain injury caused by ACOP. The following molecular docking analysis also confirmed that SFN can bind to AMPKα well through chemical bonds. In addition, an animal model of ACOP was established by exposure to carbon monoxide in a hyperbaric oxygen chamber to verify the predicted results of network pharmacology. We found that the mitochondrial ultrastructure of neurons in rats with ACOP was seriously damaged, and apoptotic cells increased significantly. The histopathological changes were obviously alleviated, apoptosis of cortical neurons was inhibited, and the number of Nissl bodies was increased in the SFN group as compared with the ACOP group (p < .05). Besides, the administration of SFN could increase the expressions of phosphorylated P-AMPK and MFN2 proteins and decrease the levels of DRP1, Caspase3, and Casapase9 proteins in the brain tissue of ACOP rats. These findings suggest that network pharmacology is a useful tool for traditional Chinese medicine (TCM) research, SFN can effectively inhibit apoptosis, protect cortical neurons from the toxicity of carbon monoxide through activating the AMPK pathway and may become a potential therapeutic strategy for brain injury after ACOP.

Investigation of the relationship between MBP gene polymorphisms and delayed encephalopathy after acute carbon monoxide poisoning

Increasing evidence reveals that delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) results from the combined effects of environmental and genetic factors. The main pathological feature of DEACMP was generalized demyelination of cerebral white matter. Myelin basic protein (MBP) levels in cerebrospinal fluid (CSF) and serum samples from DEACMP patients were elevated. This study investigated the association of MBP single nucleotide polymorphisms(SNPs) (rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336) with DEACMP. We genotyped 416 DEACMP patients and 785 age, educational level, and sex-matched ACMP patients for rs470555, rs470724, rs4890785, rs595997, rs76452994, and rs921336 SNPs using the Agena MassArray. There were no significant differences in the allele frequency distribution, four genetic models, and genotype distributions between the DEACMP and ACMP groups for rs470555, rs470724, rs4890785, and rs595997. However, significant differences were observed for rs76452994 and rs921336. This study revealed that the MBP polymorphisms, rs470555, rs470724, rs4890785, and rs595997, were not associated with DEACMP. Based on the codominant, dominant, and overdominant genetic inheritability patterns, the MBP rs76452994 and rs921366 polymorphisms were associated with DEACMP. Furthermore, the G allele of rs76452994 and T allele of rs921336 could lead to higher DEACMP risk.

Identification of proteins associated with treatment response of neoadjuvant chemoradiotherapy in rectal mucinous adenocarcinoma by co-expression network analysis based on proteomic analysis

For rectal mucinous adenocarcinoma (MAC), identifying biomarkers of neoadjuvant chemoradiotherapy (NCRT) response has become imperative. This study applied label-free mass spectrometry and weighted gene co-expression network analysis to identify hub proteins in association with the NCRT response in 20 rectal MAC patients. We identified 131 differentially abundant proteins and 7 candidate proteins associated with the NCRT response. The immunostaining expressions of six proteins (ENOA, ILEU, MDHM, RM11, PTGDS, and RL3) were significantly associated with the NCRT response. Logistic regression analysis revealed that ENOA (OR = 6.275, P = 0.006) was independent risk hub protein for the NCRT response. Tow hub proteins (ENOA and PTGDS) were identified as significant risk factors by Cox regression analysis. A prognostic risk score system was constructed: risk score = (0.910 × EXP_ENOA) + (-1.519 × EXP_PTGDS), and found to be an independent predictor of DFS in rectal MAC patients (HR = 10.308, P < 0.001). Our study suggested that ENOA may be a novel biomarker for the NCRT response and prognosis in rectal MAC patients. A two-hub-protein-based risk score system might be used for predicting tumor recurrence in rectal MAC patients. SIGNIFICANCE: NCRT resistance is a major problem in the treatment of rectal MAC patients. Identifying robust predictive biomarkers for NCRT resistance is beneficial to the stratified treatment of rectal MAC patients. In this study, label-free mass spectrometry and weighted gene co-expression network analysis identified ENOA as a potential novel biomarker for the NCRT response and prognosis. ENOA may be involved in the process of the NCRT resistance and tumor recurrence through the carbon metabolism pathway.

Neural precursor cells are decreased in the hippocampus of the delayed carbon monoxide encephalopathy rat model

The pathophysiology of delayed carbon monoxide (CO) encephalopathy remains unclear. In this study, the effects of CO exposure on the dentate gyrus (DG) were investigated in a Wistar rat model by histochemical and molecular methods. Model rats showed significant cognitive impairment in the passive-avoidance test beginning 7 days after CO exposure. Immunohistochemistry showed that compared to the control, the cell number of SRY (sex-determining region Y)-box 2 (SOX2)⁺/brain lipid binding protein (BLBP)⁺/glial fibrillary acidic protein (GFAP)⁺ cells in the DG was significantly less, but the number of SOX2⁺/GFAP⁻ cells was not, reflecting a decreased number of type 1 and type 2a neural precursor cells. Compared to the control, the numbers of CD11b⁺ cells and neuron glial antigen 2⁺ cells were significantly less, but the number of SOX2⁻/GFAP⁺ cells was not. Flow cytometry showed that the percent of live microglial cells isolated from the hippocampus in this CO rat model was significantly lower than in controls. Furthermore, mRNA expression of fibroblast growth factor 2 and glial cell-derived neurotrophic factor, which are neurogenic factors, was significantly decreased in that area. We conclude that, in this rat model, there is an association between delayed cognitive impairment with dysregulated adult hippocampal neurogenesis and glial changes in delayed CO encephalopathy.

Association between Neuron-Specific Enolase Gene Polymorphism and Delayed Encephalopathy after Acute Carbon Monoxide Poisoning

Objective

The aim of this study is to explore the relationship between neuron-specific enolase (NSE) gene polymorphism and delayed encephalopathy after acute carbon monoxide poisoning (DEACMP) and provide a theoretical basis for DEACMP pathogenesis, diagnosis, and prognosis.

Methods

To investigate this relationship, we screened 6 NSE single nucleotide polymorphisms (SNPs), based on the results of the previous genome-wide association studies (GWAS). A total of 1,201 patients, including 416 in the DEACMP group and 785 in the acute carbon monoxide poisoning (ACMP) group, were detected by the Sequenom MassARRAY® method. The genotype frequencies and alleles of the 6 NSE SNPs (rs2071074, rs2071417, rs2071419, rs11064464, rs11064465, and rs3213434) were compared using different genetic models.

Results

In the SNPs rs2071419 and rs3213434, we found that the genotypes and allele frequencies in the two groups significantly correlated with the grouping of patients (χ ² = 6.596, p = 0.037; χ ² = 8.769, p = 0.012). The haplotypes GGTTTC and CCTTTC of ACMP and DEACMP were different (χ ² = 6.563, p = 0.010; χ ² = 4.151, p = 0.042). We also observed that rs2071419 and rs3213434 significantly correlated with DEACMP-increased risk in the dominant, codominant, and overdominant genetic models. In addition, we speculated that the C allele of the rs2071419 polymorphism and the T allele of the rs3213434 polymorphism in NSE may increase the DEACMP risk (p = 0.011, p = 0.006).

Conclusions

The results show that rs2071419 and rs3213434 are susceptible sites of DEACMP. The NSE C allele of rs2071419 and T allele of rs3213434 and the haplotypes GGTTTC and CCTTTC may be risk factors for DEACMP.

iTRAQ‑based proteomics analysis of the therapeutic effects of combined anticancer bioactive peptides and oxaliplatin on gastric cancer cells

The combination of chemotherapeutic modalities may be more effective in treating gastric cancer compared with any modality alone. Previous studies have demonstrated that the combination of anticancer bioactive peptides (ACBP) and oxaliplatin (OXA) significantly inhibited the growth of the gastric cancer cell line MKN-45, promoted the apoptosis of MKN-45 cells, and caused an irreversible arrest of the MKN-45 cell cycle in the G2/M phase. In the present study, an isobaric tag for relative and absolute quantitation (iTRAQ)-based quantitative proteomics technique was used to determine the effect of ACBP-OXA treatment on the proteomics profile of MKN-45 cells. Notably, a total of 6,210 proteins were detected. Proteins with a >1.2-fold change in expression (either up- or downregulation) and P<0.05 were considered to be differentially expressed. A total of 256 differentially expressed proteins were identified through alignments with different groups. Compared with the control group, MKN-45 cells treated with ACBP, OXA and ACBP-OXA exhibited 17 (10 up- and 7 downregulated), 111 (27 up- and 84 downregulated) and 128 (53 up- and 75 downregulated) differentially expressed proteins, respectively. Of the 256 differentially expressed proteins, 6 (TPX2, NUSAP1, TOP2A, YAP, MKi-67 and GPC4) were verified by the parallel reaction monitoring method, which revealed that TPX2, NUSAP1, TOP2A, YAP, MKi-67 and GPC4 expression decreased with ACBP-OXA treatment. The cellular localization, functional annotation and biological pathways of differentially expressed proteins were examined by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analysis. The results indicated that ACBP-OXA may act through the ribosome or the AMP-activated protein kinase (AMPK) signaling pathway, and the AMPK signaling pathway may be an important mediator of the inhibitory effects of ACBP-OXA on MKN-45 gastric cancer cells. In summary, iTRAQ-based proteomics analysis of the effect of ACBP-OXA on MKN-45 cells may guide future therapeutic strategies for gastric cancer. In addition, the present study may help provide new insights into the therapeutic role of combined ACBP and OXA in gastric cancer.