Xanthomonas campestris pathovar campestris (Xcc) is the causative agent of crucifer black rot disease, which causes severe losses in agricultural yield world-wide. This bacterium is a model organism for studying plant-bacteria interactions. We sequenced the complete genome of Xcc 8004 (5,148,708 bp), which is highly conserved relative to that of Xcc ATCC 33913. Comparative genomics analysis indicated that, in addition to a significant genomic-scale rearrangement cross the replication axis between two IS1478 elements, loss and acquisition of blocks of genes, rather than point mutations, constitute the main genetic variation between the two Xcc strains. Screening of a high-density transposon insertional mutant library (16,512 clones) of Xcc 8004 against a host plant (Brassica oleraceae) identified 75 nonredundant, single-copy insertions in protein-coding sequences (CDSs) and intergenic regions. In addition to known virulence factors, full virulence was found to require several additional metabolic pathways and regulatory systems, such as fatty acid degradation, type IV secretion system, cell signaling, and amino acids and nucleotide metabolism. Among the identified pathogenicity-related genes, three of unknown function were found in Xcc 8004-specific chromosomal segments, revealing a direct correlation between genomic dynamics and Xcc virulence. The present combination of comparative and functional genomic analyses provides valuable information about the genetic basis of Xcc pathogenicity, which may offer novel insight toward the development of efficient methods for prevention of this important plant disease.

Background: Neuroblastoma (NB) is the most frequent pediatric malignant neoplasm that originates from embryonic neural crest cells. Urinary catecholamines in 24-h urine are most commonly analyzed for the diagnosis of neuroblastoma at good sensitivity; however, it is challenging to collect 24-h urine samples in a pediatric population. Therefore, development of more rapid, non-invasive and cost-effective tools for the diagnosis of NB remains needed. Serum immunoglobulin G (IgG) galactosylation have been found highly associated with adult cancers in our previous study.Methods: To explore the potential use of serum IgG galactosylation in aiding diagnosis of neuroblastoma, serum IgG galactosylation profiles of 26 neuroblastoma cases and 30 age-matched non-malignant controls were analyzed by MALDI MS. The alteration of IgG galactosylation in neuroblastoma patients was measured by a Gal-ratio formula: G0/(G1+G2×2), calculating the relative intensities of agalactosylated N-glycan (G0) vs mono-galactosyl N-glycan (G1) and digalactosyl N-glycan (G2).Results: The results showed that IgG Gal-ratios were significantly higher in neuroblastoma cases compared with non-malignant controls (p=5.0×10-4). And the Gal-ratio data generated sensitivity and specificity of 84.62% and 60.00%, combined with an AUC (area under the curve) of 0.80.Conclusions: The analysis of serum IgG galactosylation distribution may play a suggestive role for neuroblastoma diagnosis, or serve as a potential biomarker for NB diagnosis.

2020 Background: Lung cancer is one of the most common causes of brain metastases (BMs) and is always associated with poor prognosis. To evaluate the characteristics of the tumor immune microenvironment in brain metastases of non-small-cell lung cancer (NSCLC), we investigated the immunophenotype of primary NSCLC and paired brain metastases. Methods: Forty-three Chinese patients with NSCLC who had BMs at presentation or during the course of their disease were admitted to the Sun Yat-Sen University Cancer Center (Guangzhou, China) from 2000 to 2019. RNA sequencing (RNA-seq) of eighty-six formalin-fixed, paraffin embedded (FFPE) samples from primary lung tumors and paired brain metastases of 43 patients was conducted to comprehensively analyze the tumor immune microenvironment. Results: Our data revealed that brain metastases compared with primary lung tumors exhibited reduced tumor infiltrating lymphocytes (TILs) (all 28 immune cell subtypes P < 0.05), lower fraction of activated CD8 T cell and effector memory CD8 T cell in total TILs (P = 0.028, P < 0.001, respectively); higher fraction of macrophage and neutrophil in total TILs (P < 0.001, P < 0.01, respectively). Comparing with the primary lung tumors, the scores of some immune related signatures, including MHC non-class signature, IFN gamma signature and T-cell-inflamed gene-expression profile (GEP) signature, were significantly lower in brain metastases (P = 0.004, P = 0.009, P = 0.004, respectively), while the score of MHC class-II signature was higher in brain metastases (P = 0.045). We found the distributions of tumor microenvironment immune types (TMIT) in brain metastases and primary lung tumors were different. Brain metastases contained significantly lower proportion of TMIT I (high PD-L1/ high CD8A) (23%) than primary lung tumors (47%) (P < 0.05). Besides, we found three immune inhibitory checkpoint molecules, namely C10orf54 (VISTA), CTLA4 and CD274 (PD-L1) were downregulated in brain metastases than in primary lung tumors (P < 0.001, P < 0.001, P = 0.034, respectively). Moreover, there was poor correlation of PD-L1 expression between paired brain metastases and primary lung tumors (R = 0.28, P = 0.068). Unsupervised hierarchic cluster analysis revealed the primary lung tumors had two distinct patterns of immune gene signatures, namely Cluster A and Cluster B, and the tumors in Cluster B were immune rich, but associated with poor prognosis (log-rank P = 0.021). Conclusions: Our work illustrates the immune landscape of brain metastases from NSCLC, and suggests that the tumor immune microenvironment in brain metastases compared with primary lung tumors is further immunosuppressed, that may help guide immunotherapeutic strategies for NSCLC brain metastases.

Objective: Sevoflurane is a common anesthetic and is widely used in pediatric clinical surgery to induce and maintain anesthesia through inhalation. Increasing studies have revealed that sevoflurane has neurotoxic effects on neurons, apoptosis, and memory impairment. miR-384 is involved in the process of neurological diseases.However, the role of miRNA-384-3p in sevoflurane-induced nerve injury is not clear.This study focused on exploring the roles and mechanisms of miRNA-384-3p in sevoflurane-induced nerve injury.Methods: Seven-day-old rats were exposed to 2.3% sevoflurane to induce nerve injury.The morphological changes in neurons in the hippocampal CA1 region were detected by HE staining and Nissl staining. Neuronal apoptosis was detected by TUNEL and Western blot assays. Spatial memory and learning ability were detected by the Morris water maze assay. The target gene of miRNA-384-3p was verified through a luciferase reporter assay. A rescue experiment was used to confirm the miRNA-384-3p pathway in sevoflurane-induced nerve injury.Results: Sevoflurane reduced miRNA-384-3p expression in the rat hippocampus. miRNA-384-3p alleviated sevoflurane-induced morphological changes in hippocampal neurons and apoptosis of neurons in the hippocampal CA1 region. Meanwhile, miRNA-384-3p attenuated the decline in spatial memory and learning ability induced by sevoflurane. miRNA-384-3p alleviated sevoflurane-induced nerve injury by inhibiting the expression of adaptor-associated kinase 1 (Aak1). Conclusion:Our findings revealed the role and mechanism of miRNA-384-3p in sevoflurane-induced nerve injury, suggesting that miRNA-384-3p could be a novel and promising strategy for reducing sevoflurane-induced neurotoxicity.

BackgroundNeuroblastoma is the most common extracranial childhood solid tumor which accounts for 10% of the malignancies and 15% of the cancer fatalities in children. N-glycosylation is one of the most frequent post-translation protein modification playing a vital role in numerous cancers. N-glycosylation changes in neuroblastoma patient serum have not been studied in existing reports. The comprehensive analyses of serum N-glycomics in neuroblastoma can provide useful information of potential disease biomarkers and new insights of the pathophysiology in neuroblastoma.MethodsThe total serum protein N-glycosylation was analyzed in 33 neuroblastoma patients and 40 age- and sex-matched non-malignant controls. N-glycans were enzymatically released, derivatized to discriminate linkage-specific sialic acid, purified by HILIC-SPE, and identified by MALDI-TOF-MS. Peak areas were acquired by the software of MALDI-MS sample acquisition, processed and analyzed by the software of Progenesis MALDI.ResultsThree glyco-subclasses and six individual N-glycans were significantly changed in neuroblastoma patients compared with controls. The decreased levels of high mannose N-glycans, hybrid N-glycans, and increased levels of α2,3-sialylated N-glycans, multi-branched sialylated N-glycans were observed in neuroblastoma patients. what is more, a glycan panel combining those six individual N-glycans showed a strong discrimination performance, with an AUC value of 0.8477.ConclusionsThis study provides new insights into N-glycosylation characteristics in neuroblastoma patient serum. The analyses of total serum protein N-glycosylation could discriminate neuroblastoma patients from non-malignant controls. The alterations of the N-glycomics may play a suggestive role for neuroblastoma diagnosis and advance our understanding of the pathophysiology in neuroblastoma.