Comparative genomic and metabolomic analysis reveals the potential of a newly isolated Enterococcus faecium B6 involved in lipogenic effects.

Evidence has indicated that Enterococcus plays a vital role in non-alcoholic fatty liver disease (NAFLD) development. However, the microbial genetic basis and metabolic potential in the disease are yet unknown. We previously isolated a bacteria Enterococcus faecium B6 (E. faecium B6) from children with NAFLD for the first time. Here, we aim to systematically investigate the potential of strain B6 in lipogenic effects. The lipogenic effects of strain B6 were explored in vitro and in vivo. The genomic and functional characterizations were investigated by whole-genome sequencing and comparative genomic analysis. Moreover, the metabolite profiles were unraveled by an untargeted metabolomic analysis. We demonstrated that strain B6 could effectively induce lipogenic effects in the liver of mice. Strain B6 contained a circular chromosome and two circular plasmids and posed various functions. Compared to the other two probiotic strains of E. faecium, strain B6 exhibited unique functions in pathways of ABC transporters, phosphotransferase system, and amino sugar and nucleotide sugar metabolism. Moreover, strain B6 produced several metabolites, mainly enriched in the protein digestion and absorption pathway. The unique potential of strain B6 in lipogenic effects was probably associated with glycolysis, fatty acid synthesis, and glutamine and choline transport. This study pioneeringly revealed the metabolic characteristics and specific detrimental traits of strain B6. The findings provided new insights into the underlying mechanisms of E. faecium in lipogenic effects, and laid essential foundations for further understanding of E. faecium-related disease.

Low caveolin-1 levels and symptomatic intracranial haemorrhage risk in large-vessel occlusive stroke patients after endovascular thrombectomy.

BACKGROUND AND PURPOSE: Caveolin-1 (Cav-1) is reported to mediate blood-brain barrier integrity after ischaemic stroke. Our purpose was to assess the role of circulating Cav-1 levels in predicting symptomatic intracranial haemorrhage (sICH) amongst ischaemic stroke patients after endovascular thrombectomy (EVT). METHODS: Patients with large-vessel occlusive stroke after EVT from two stroke centres were prospectively included. Serum Cav-1 level was tested after admission. sICH was diagnosed according to the Heidelberg Bleeding Classification. RESULTS: Of 325 patients (mean age 68.6 years; 207 men) included, 47 (14.5%) were diagnosed with sICH. Compared with patients without sICH, those with sICH had a lower concentration of Cav-1. After adjusting for potential confounders, multivariate regression analysis demonstrated that the increased Cav-1 level was associated with a lower sICH risk (odds ratio 0.055; 95% confidence interval 0.005-0.669; p = 0.038). Similar results were obtained when Cav-1 levels were analysed as a categorical variable. Using a logistic regression model with restricted cubic splines, a linear and negative association of Cav-1 concentration was found with sICH risk (p = 0.001 for linearity). Furthermore, the performance of the conventional risk factors model in predicting sICH was substantially improved after addition of the Cav-1 levels (integrated discrimination index 2.7%, p = 0.002; net reclassification improvement 39.7%, p = 0.007). CONCLUSIONS: Our data demonstrate that decreased Cav-1 levels are related to sICH after EVT. Incorporation of Cav-1 into clinical decision-making may help to identify patients at a high risk of sICH and warrants further consideration.

Cultivated Enterococcus faecium B6 from children with obesity promotes nonalcoholic fatty liver disease by the bioactive metabolite tyramine.

Gut microbiota plays an essential role in nonalcoholic fatty liver disease (NAFLD). However, the contribution of individual bacterial strains and their metabolites to childhood NAFLD pathogenesis remains poorly understood. Herein, the critical bacteria in children with obesity accompanied by NAFLD were identified by microbiome analysis. Bacteria abundant in the NAFLD group were systematically assessed for their lipogenic effects. The underlying mechanisms and microbial-derived metabolites in NAFLD pathogenesis were investigated using multi-omics and LC-MS/MS analysis. The roles of the crucial metabolite in NAFLD were validated in vitro and in vivo as well as in an additional cohort. The results showed that Enterococcus spp. was enriched in children with obesity and NAFLD. The patient-derived Enterococcus faecium B6 (E. faecium B6) significantly contributed to NAFLD symptoms in mice. E. faecium B6 produced a crucial bioactive metabolite, tyramine, which probably activated PPAR-γ, leading to lipid accumulation, inflammation, and fibrosis in the liver. Moreover, these findings were successfully validated in an additional cohort. This pioneering study elucidated the important functions of cultivated E. faecium B6 and its bioactive metabolite (tyramine) in exacerbating NAFLD. These findings advance the comprehensive understanding of NAFLD pathogenesis and provide new insights for the development of microbe/metabolite-based therapeutic strategies.

Association of Chinese visceral adiposity index with clinical outcome in patients after endovascular thrombectomy.

BACKGROUND AND PURPOSE: The Chinese Visceral Adiposity Index (CVAI) is a reliable indicator of visceral adiposity dysfunction in the Chinese population. We aimed to evaluate the association between CVAI and clinical outcome in Chinese ischemic stroke patients who received endovascular thrombectomy (EVT). METHODS: This study retrospectively included patients with large vessel occlusive stroke receiving EVT treatment in 2 China stroke centers. Baseline CVAI was calculated after admission. Patients with a modified Rankin scale score ≥ 3 at 3 months after ischemic stroke were defined as poor outcome. Binary multivariate logistic regression models were utilized to explore the association between CVAI and the risk of 90-day unfavorable outcome. RESULTS: A total of 453 patients (mean age, 70.4  ± 12.1 years; 280 male) were included. During the 90-day follow-up, 236 (52.1 %) patients experienced poor outcome. After multivariable adjustment for potential confounders, increasing CVAI was associated with an increased risk of 90-day poor outcome (odds ratios, per-standard deviation increase: 1.521; 95 % confidence interval, 1.127-2.052; P = 0.006). Similar significant results were observed when the CVAI was analyzed as a categorical variable. Furthermore, the multiple-adjusted spline regression model showed an inverted J-shape association between CVAI and risk of unfavorable outcome (P = 0.048 for non-linearity). CONCLUSIONS: This study demonstrated that CVAI is positively correlated with 90-day poor outcome in Chinese ischemic stroke patients after EVT.

Prevotella histicola Transplantation Ameliorates Cognitive Impairment and Decreases Oxidative Stress in Vascular Dementia Rats.

Vascular dementia is a type of dementia from brain damage caused by cerebrovascular lesions and vascular risk factors. Prevotella histicola is a species of Prevotella, belonging to the category of obligate anaerobe. The purpose of our work was to study the protection of Prevotella histicola on cognitive function in rats subjected to vascular dementia (VaD) and investigate underlying molecular mechanisms. The rats were randomly divided into three groups: control group, 2VO group and 2VO + Prevotella histicola group. The VaD rats (the 2VO group and 2VO + Prevotella histicola group) were generated by bilateral common carotid artery occlusion (2VO). Rats in the 2VO+ Prevotella histicola group were administered with Prevotella histicola twice daily. In comparison with the rats in the 2VO group, rats in the 2VO + Prevotella histicola group presented an enhanced cognitive ability, increased synapse-associated protein expression, a downregulation of proinflammatory factors and an upregulation of neurotrophic factors. The relevant mechanism of the protective effect of Prevotella histicola may be associated with the inhibition of glial cell-associated inflammation by regulating phosphorylation of CaMKII. In conclusion, Prevotella histicola attenuates neurological impairments via regulating synapse-associated protein expression and the liberation of inflammatory elements in vascular dementia rats. The findings above might benefit the development of Prevotella histicola transplantation as a promising treatment of VaD.

An automatic recognition method of nematode survival rate based on bright field and dark field experimental images.

BACKGROUND: The survival rate of experimental animals is a very important index in chemical toxicity evaluation experiments. The calculation of nematode survival rate is used in many experiments. OBJECTIVE: Traditional survival rate quantification methods require manual counting. This is a time-consuming and laborious work when using 384-well plate for high-throughput chemical toxicity assessment experiments. At present, there is a great need for an automatic method to identify the survival rate of nematodes in the experiment of chemical toxicity evaluation. METHODS: We designed an automatic nematode survival rate recognition method by combining the bright field experimental image of nematodes and the dark field image of nematodes which is captured after adding Propidium Iodide dye, and used it to calculate the nematode survival rate in different chemical environments. Experiment results show that the survival rate obtained by our automatic counting method is very similar to the survival rate obtained by manual counting. RESULTS: Through several different chemical experiments, we can see that chemicals with different toxicity have different effects on the survival rate of nematodes. And the survival rate of nematodes under different chemical concentrations has an obvious gradient trend from high concentration to low concentration. In addition, our method can quantify the motility of nematodes. There are also significant differences in the motility of nematodes cultured in different chemical environments. Moreover, the nematode motility under different chemical concentrations showed an obvious gradient change trend from high concentration to low concentration. CONCLUSION: Our study provides an accurate and efficient nematode survival rate recognition method for chemical toxicology research.

Identification of core genes in prefrontal cortex and hippocampus of Alzheimer's disease based on mRNA-miRNA network.

Alzheimer's disease (AD) is a neurodegenerative disorder with cognitive impairment and abnormal mental behaviour. There is currently no effective cure. The development of early diagnostic markers and the mining of potential therapeutic targets are one of the important strategies. This study aimed to explore potential biomarkers or therapeutic targets related to AD in the hippocampus and prefrontal cortex, two brain regions highly related to AD. Differentially expressed genes and miRNAs between AD patients and healthy controls were obtained from the Gene Expression Omnibus database. The mRNA-miRNA network was constructed and key genes involved in AD were screened out by protein-protein interaction analysis, and were subsequently verified by independent datasets and qPCR in an AD mouse model. Our findings showed that six hub genes including CALN1, TRPM7, ATR, SOCS3, MOB3A and OGDH were believed to be involved in the pathogenesis of AD. Western blot analysis further determined that CALN1, ATR and OGDH were the possible biomarkers and therapeutic targets for AD. In addition, 6 possible miRNAs biomarkers have also been verified by qPCR on AD animal models. Our findings may benefit clinical diagnosis and early prevention of AD.

Associations between serum placental leucine aminopeptidase and pregnancy outcomes.

OBJECTIVE: To investigate the association between serum concentrations of placental leucine aminopeptidase (P-LAP) and hypertensive disorders in pregnancy (HDP), gestational diabetes mellitus (GDM), and perinatal mortality. METHODS: In a prospective study, women with singleton pregnancies and affected by HDP, GDM, or fetal death, and those who were healthy, were enrolled at Shenzhen Seventh People's Hospital, Shenzhen, China, between January 2014 and July 2015. Serum P-LAP concentrations at delivery/fetal death were compared among the groups. The predictive value of serum P-LAP levels in fetal death was evaluated. RESULTS: Serum P-LAP concentrations were (mean ± SEM) 74.02 ± 8.45 U/L in the HDP group (n=38), 72.57 ± 12.03 U/L in the GDM group (n=35), and 3.76 ± 3.02 U/L in the fetal death group (n=14), all of which were significantly lower than the mean concentration of 107.11 ± 30.68 U/L in the control group (n=30; P=0.031, P=0.042, and P<0.001, respectively). On the basis of the receiver operating characteristic curve, low serum P-LAP levels had high sensitivity and specificity for predicting fetal death (100% and 78.9%, respectively, for a serum P-LAP cutoff of 47.07 U/L). CONCLUSION: Serum P-LAP levels were reduced among patients with HDP and GDM, and extremely low among patients affected by fetal death. Serum P-LAP is potentially a viable predictor of fetal death.