Mesenteric Adipose Tissue-Derived Klebsiella variicola Disrupts Intestinal Barrier and Promotes Colitis by Type VI Secretion System

Mesenteric adipose tissue (MAT) in Crohn's disease (CD) is associated with transmural inflammation. Extended mesenteric excision can reduce surgical recurrence and improve long-term outcomes, indicating that MAT plays an important role in the pathogenesis of CD. Bacterial translocation has been reported to occur in the MAT of patients with CD (CD-MAT), but the mechanisms by which translocated bacteria lead to intestinal colitis remain unclear. Here it is shown that members of Enterobacteriaceae are highly enriched in CD-MAT compared with non-CD controls. Viable Klebsiella variicola in Enterobacteriaceae is isolated exclusively in CD-MAT and can induce a pro-inflammatory response in vitro and exacerbates colitis both in dextran sulfate sodium (DSS)-induced colitis mice model and IL-10^-/- spontaneous colitis mice model. Mechanistically, active type VI secretion system (T6SS) is identified in the genome of K. variicola, which can impair the intestinal barrier by inhibiting the zonula occludens (ZO-1) expression. Dysfunction of T6SS by CRISPR interference system alleviates the inhibitory effect of K. variicola on ZO-1 expression and attenuated colitis in mice. Overall, these findings demonstrate that a novel colitis-promoting bacteria exist in the mesenteric adipose tissue of CD, opening a new therapeutic avenue for colitis management.

Microbiota in mesenteric adipose tissue from Crohn's disease promote colitis in mice

BACKGROUND

Mesenteric adipose tissue (mAT) hyperplasia, known as creeping fat is a pathologic characteristic of Crohn's disease (CD). The reserve of creeping fat in surgery is associated with poor prognosis of CD patients, but the mechanism remains unknown.

METHODS

Mesenteric microbiome, metabolome, and host transcriptome were characterized using a cohort of 48 patients with CD and 16 non-CD controls. Multidimensional data including 16S ribosomal RNA gene sequencing (16S rRNA), host RNA sequencing, and metabolome were integrated to reveal network interaction. Mesenteric resident bacteria were isolated from mAT and functionally investigated both in the dextran sulfate sodium (DSS) model and in the Il10 gene-deficient (Il10^-/-) mouse colitis model to validate their pro-inflammatory roles.

RESULTS

Mesenteric microbiota contributed to aberrant metabolites production and transcripts in mATs from patients with CD. The presence of mAT resident microbiota was associated with the development of CD. Achromobacter pulmonis (A. pulmonis) isolated from CD mAT could translocate to mAT and exacerbate both DSS-induced and Il10 gene-deficient (Il10^-/-) spontaneous colitis in mice. The levels of A. pulmonis in both mAT and mucous layer from CD patients were higher compared to those from the non-CD group.

CONCLUSIONS

This study suggests that the mesenteric microbiota from patients with CD sculpt a detrimental microenvironment and promote intestinal inflammation. Video abstract.

Genome-wide single nucleotide polymorphism array and whole-genome sequencing reveal the inbreeding progression of Banna minipig inbred line

Inbred pigs are promising animal models for biomedical research and xenotransplantation. Established in 1980, the Banna minipig inbred (BMI) line originated from a sow and its own male offspring. It was selected from a small backcountry minority Lahu village, where records show that no other pig breed has ever been introduced. During the inbreeding process, we perfomed extreme inbreeding over 23 consecutive generations using full-sibling or parent-offspring mating. In order to investigate the inbreeding effects in BMI pigs across generations over the past 40 years, in this study we conducted a genome-wide SNP genotyping of the last 10 generations, representing generations 14-23. In total, we genotyped 57,746 SNPs, corresponding to an average decrease in heterozygosity rate of 0.0078 per generation. Furthermore, we were only able to identify 18,216 polymorphic loci with a MAF larger than 0.05, which is substantially lower than the values in previous reports on other pig breeds. In addition, we sequenced the genome of the first pig in the twenty-third generation (inbreeding coefficient 99.28%) to an average coverage of 12.4× to evaluate at the genome level the impact of advanced inbreeding. ROH analysis indicates that BMI pigs have longer ROHs than Wuzhishan and Duroc pigs. Those long ROH regions in BMI pigs are enriched for distinct functions compared with the highly polymorphic regions. Our study reveals a genome-wide allele diversity loss during the progress of inbreeding in BMI pigs and characterizes ROH and polymorphic regions as a result of inbreeding. Overall, our results indicate the successful establishment of the BMI line, which paves the way for further in-depth studies.

Incidence and mortality of nasopharyngeal carcinoma: interim analysis of a cluster randomized controlled screening trial (PRO-NPC-001) in southern China

BACKGROUND

Previous mass screening studies have shown that IgA antibodies against Epstein-Barr Virus (EBV) can facilitate early detection of nasopharyngeal carcinoma (NPC), but the impact of EBV-antibody screening for NPC-specific mortality remains unknown.

PATIENTS AND METHODS

A prospective, cluster randomized, controlled trial for NPC screening (PRO-NPC-001) was conducted in 3 selected towns of Zhongshan City and 13 selected towns of Sihui City in southern China beginning in 2008. Serum samples of the screening group were tested for two previously selected anti-EBV antibodies. Subjects with serological medium risk were subsequently retested annually for 3 years, and those with serological high risk were referred to otorhinolaryngologists for diagnostic check-up. An interim analysis was carried out to evaluate the primary end points of the NPC-specific mortality and the early diagnostic rate, and the secondary end point of the NPC incidence, through linkage with the database of Zhongshan City.

RESULTS

Among 70 296 total subjects, 29 413 screened participants (41.8% of the total subjects) in the screening group and 50 636 in the control group, 153 (43.3 per 100 000 person-year), 62 (55.3 per 100 000 person-year) and 99 (33.1 per 100 000 person-year) NPC cases were identified. The early diagnostic rates of NPC were significantly higher in the participants (79.0%, P < 0.0001) and the screening group (45.9%, P < 0.0001) compared with the control group (20.6%). Although no differences were found between NPC-specific mortality of the screening group and the control group [relative risk (RR)= 0.82, 95% confidence interval (CI) 0.37-1.79], lower NPC-specific mortality was noticed among participants from the screening group versus the control group (RR = 0.22, 95% CI 0.09-0.49).

CONCLUSION

IgA antibodies against EBV can identify high-risk population and was effective in screening for early asymptomatic NPC. Although the mortality reduction was not significant in the primary end point, we noted encouraging evidence of a mortality reduction in screening participants in this interim analysis.

CLINICAL TRIAL NUMBER

NCT00941538.

Screening and identification of various components in Thalictrum fortunei using a combination of liquid chromatography/time-of-flight tandem mass spectrometry

An approach for screening and identification of various components in a traditional Chinese medicine (TCM), using a combination of LC/TOF-MS technique was described in this paper. The chemical profile of Thalictrum fortunei, well-known in TCM, was studied using the established method. The possibilities of screening and identifying non-target components inside TCM with modern data acquisition methods of acceleration time of flight mass spectrometers, such as data-dependent MS to MS/MS switching were investigated. As a result, 27 components were identified. This study was aimed to screen and identify the main components of T. fortunei using LC/TOF-MS, expecting to provide a rapid, sensitive, economical and systematical method for the identification and further quality evaluation of TCM preparation.

Effect of triterpene acids of Eriobotrya japonica (Thunb.) Lindl. leaf and MAPK signal transduction pathway on inducible nitric oxide synthase expression in alveolar macrophage of chronic bronchitis rats

The goal of this study was to investigate the possible therapy mechanism of triterpene acids of Eriobotrya japonica (Thunb.) Lindl. Leaf (TAL) in alveolar macrophage (AM) of chronic bronchitis (CB) rats. CB model was established by injection of bacillus calmette guein (BCG) plus lipopolisacharide (LPS) in rats. TAL significantly inhibited the increased NO concentration, iNOS expression and phosphorylation of p38 MAPK in alveolar macrophages (AMs) of CB rats. Using in vivo test, we found that SB203580, a p38 MAPK inhibitor, (10 muM) significantly inhibited inducible nitric oxide synthase (iNOS) mRNA expression in AM. This data indicate that TAL highly decreases excessive iNOS expression and NO induction, and p38 MAPK signal transduction participates in iNOS expression and NO induction in AM of CB rats. The effect of TAL on iNOS expression in AM may be related to its inhibition of p38 MAPK signal transduction.

Fasting regulates the expression of adiponectin receptors in young growing pigs

Adiponectin is an adipocyte-derived hormone that can improve insulin sensitivity. Its functions in regulating glucose utilization and fatty acid metabolism in mammals are mediated by 2 subtypes of adiponectin receptors (AdipoR1 and AdipoR2). This study was conducted to determine the effect of fasting on the expression of adiponectin and its receptors. The expression of adiponectin was not affected in s.c. adipose tissue, but adiponectin expression increased in visceral adipose tissue after fasting. In contrast, expression of both AdipoR mRNA was increased in the liver and s.c. adipose tissue of 24-h-fasted pigs compared with fed pigs, but the mRNA in muscle and visceral adipose tissue was not affected by fasting. A third putative adiponectin receptor, T-cadherin, was cloned and the mRNA expression was determined. T-Cadherin has been recognized to act as a vascular adiponectin receptor in vascular endothelial and smooth muscle cells. Our data showed that the expression of T-cadherin was decreased in the muscle of fasted pigs, suggesting that the expression of T-cadherin can be regulated by feeding status. In summary, in young pigs, adiponectin mRNA was up-regulated by fasting in visceral, but not s.c., adipose tissue, whereas AdipoR1 and AdipoR2 mRNA were increased in s.c., but not visceral, adipose tissue. The adiponectin receptor, T-cadherin, was expressed in s.c. and visceral adipose tissue and in muscle, but only muscle mRNA expression was decreased by fasting.

Sustained elevation of Epstein-Barr virus antibody levels preceding clinical onset of nasopharyngeal carcinoma

We have monitored Epstein–Barr virus (EBV) IgA antibody levels of 39 nasopharyngeal carcinoma (NPC) cases for up to 15 years before clinical onset of NPC, and assessed preclinical serologic status of another 68 cases. Our results identify a serologic window preceding diagnosis when antibody levels are raised and sustained. This window can persist for as long as 10 years, with a mean duration estimated to as 37±28 months. Ninety-seven of these 107 NPC cases exhibited such a window. Cases that did not may reflect individual antibody response to EBV. Serologic screening at enrollment identified those cases who had already entered the window and became clinically manifested earlier (median=28 months) than those who entered the window after enrollment (median=90 months). The former account for 19 of 21 cases diagnosed within 2 years of screening. Nasopharyngeal carcinoma risk levels among seropositive subjects were also highest during this period. Both prediction rates and risk levels declined thereafter; cases detected at later times were composed of increasing proportions of individuals who entered the serological window after screening. Our findings establish EBV antibody as an early marker of NPC and suggest that repeated screening to monitor cases as they enter this window has considerable predictive value, with practical consequences for cancer treatment.

[Chemical constituents of Rosa laevigata Michx]

Six compounds were isolated from Rosa laevigata. Five of them were obtained from the ethanolic extract and identified as 2 alpha, 3 beta, 19 alpha, 23-tetrahydroxyurs-12-en-28-oic acid, 2 alpha, 3 alpha, 19 alpha, 23-tetrahydroxyurs-12-en-28-oic acid, euscaphic acid, beta-sitosterol and daucosterol. The other one was obtained from the acetate of emulsive layer of the petroleum ether and elucidared as 2 alpha, 3 beta-dihydrolup-28-methyl ester diacetate.