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An important intestinal bacterial strain Akkermansia muciniphila contributes to improving carbohydrate and lipid metabolism, thus alleviating obesity symptoms. Here, we find that the Akk membrane protein Amuc_1100 regulates lipid metabolism in 3T3-L1 preadipocytes.

Many studies have shown that gut microbiota is closely related to autoimmune diseases (ADs). Studies on gut microbiota and ADs have also increased significantly, but no bibliometric analysis has summarized the association between gut microbiota and ADs. This study aimed to conduct a bibliometric and visual analysis of published studies on gut microbiota and ADs. Based on the Web of Science Core Collection SCI-expanded database, we utilize Excel 2019 and visualization analysis tools VOSviewer and co-occurrence13.2 (COOC13.2) for analysis. A total of 2516 related kinds of literature were included, and the number of papers presented an overall increasing trend. The country/region with the most publications is the USA, the institution is the Harvard Medical School, and the author is Mikael Knip from the USA. Hot research areas include intestinal regulation (such as dysbiosis, short chain fatty acids, and probiotics), multisystem ADs (such as multiple sclerosis, rheumatoid arthritis, and inflammatory bowel disease), and immune-related cells (such as T cells, and dendritic cells). Psoriasis, dysbiosis, autoimmune liver disease, and fecal microbiota transplantation may be the future research direction. Our research results can help researchers grasp the current status of ADs and gut microbiota research and find new research directions in the future.

Natural products (NPs) are a consistent source of antimicrobial metabolites and pesticide leads and are largely produced by Pseudomonads-like soil-dwelling microorganisms. Herein we report the isolation of Pseudomonas mosselii strain 923 from rice rhizosphere soils of paddy fields; this strain specifically inhibited the growth of rice bacterial pathogens Xanthomonas oryzae pv. oryzae (Xoo) and X. oryzae pv. oryzicola (Xoc) and the fungal pathogen Magnaporthe oryzae. The antimicrobial compound produced by P. mosselii 923 was purified and identified as pseudoiodinine using HRMS, NMR and single-crystal X-ray diffraction. Genome-wide random mutagenesis, transcriptome analysis and biochemical assays were used to define the pseudoiodinine biosynthetic cluster as a seven-gene operon, which was designated psdABCDEFG. Pseudoiodinine biosynthesis is proposed to initiate from GTP, which is converted into 2,5-diamino-6-(5-phospho-d-ribosylamino) pyrimidin-4(3H)-one by PsdD and converted to 5-amino-6-(5-phospho-d-ribitylamino) uracil by PsdG, followed by cyclization with glycine by PsdC/PsdE and an unknown ring contraction and two methylation reactions by PsdA and PsdF. Transposon mutagenesis indicated that pseudoiodinine biosynthesis is mediated by the global regulator GacA. Further regulation is mediated by two noncoding small RNAs, rsmY and rsmZ, that positively regulate pseudoiodinine transcription, and the carbon storage regulators CsrA2 and CsrA3, which negatively regulate expression. A 22.4-fold increase in pseudoiodinine production was achieved by optimizing the media used for fermentation, overexpressing the biosynthetic operon, and removing the CsrA binding sites. Use of P. mosselii strain 923 and purified pseudoiodinine in planta revealed that both of them inhibited X. oryzae without affecting the rice host, suggesting that pseudoiodinine can be used to control plant diseases.

ObjectivesInsulin-like growth factor-1 (IGF-1) and bone morphogenetic protein 2 (BMP-2) both promote osteogenesis of bone marrow mesenchymal stem cells (BMSCs). IGF-1C, the C domain peptide of IGF-1, and P24, a BMP-2-derived peptide, both have similar biological activities as their parent growth factors. This study aimed to investigate the effects and their mechanisms of polypeptides IGF-1C and P24 on the osteogenic differentiation of BMSCs.MethodsThe optimum concentrations of IGF-IC and P24 were explored. The effects of the two polypeptides on the proliferation and osteogenic differentiation of BMSCs were examined using the Cell Counting Kit-8(CCK-8), Alkaline phosphatase (ALP) staining, ALP activity assay, alizarin red S staining, qPCR, and western blotting. In addition, specific pathway inhibitors were utilized to explore whether p38 and JNK pathways were involved in this process.ResultsThe optimal concentrations of action were both 50 μg/ml. IGF-1C and P24 synergistically promoted the proliferation of BMSCs, increased ALP activity and the formation of calcified nodules and upregulated the mRNA and protein levels of osterix (Osx), runt-related transcription factor 2 (Runx2), and osteocalcin (Ocn), phosphorylation level of p38 and JNK proteins also improved. Inhibition of the pathways significantly reduced the activation of p38 and JNK, blocked the expression of Runx2 while inhibiting ALP activity and the formation of calcified nodules.ConclusionsThese findings suggest IGF-1C and P24 synergistically promote the osteogenesis of BMSCs through activation of p38 and JNK signal pathways.

Olanzapine (OLZ) is one of the most effective atypical antipsychotics but is associated with severe metabolic side effects, in which the gut microbiota plays an important role. Akkermansia muciniphila (A. muciniphila; Akk), a Gram-negative anaerobic bacterium in the intestine, can potentially improve metabolic syndrome. This study investigated the effect and underlying mechanisms of an A. muciniphila subtype (A. muciniphilasub; Akksub) on OLZ-induced metabolic dysfunction in lean and obese mice. C57BL/6 female mice were fed a high-fat diet to induce obesity or normal chow for 8 weeks before OLZ treatment for 16 weeks. During the treatment period, mice in each group were orally administrated A. muciniphilasub. Weight gain, glucose and lipid metabolism, and inflammation were evaluated. A. muciniphilasub decreased OLZ-related weight gain only at week 16 in lean mice and significantly alleviated OLZ-induced hyperglycemia irrespective of diet. This was accompanied by reduced levels of glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK)—key enzymes in hepatic gluconeogenesis—and OLZ-associated insulin resistance. Moreover, OLZ-induced increases in serum interleukin (IL)-6 and tumor necrosis factor (TNF)-α levels were improved by A. muciniphilasub in both obese and lean mice. OLZ did not increase serum lipid levels or hepatic fat accumulation. A. muciniphilasub improves OLZ-related hyperglycemia via regulation of G6Pase and PEPCK levels and insulin resistance. Moreover, A. muciniphilasub alleviates systemic inflammation caused by OLZ. A. muciniphilasub is a promising probiotic treatment for OLZ-induced metabolic dysfunction.

The present study revealed the genomic architecture of Akkermansia in human gut by analyzing 1,119 near-complete metagenome-assembled genomes, 84 public available genomes, and 1 newly sequenced A. glycaniphila strain. We found that 1) the genomes of Akkermansia formed 4 species (including 2 candidate species) with distinct interspecies similarity and differed genomic characteristics, and 2) the population of A. muciniphila was structured by 3 previously identified phylogroups (Amuc I, II, and III) referring to 1,132 genomes and 1 new phylogroup (defined as Amuc IV) that contained 62 genomes. Amuc III was presented in Chinese population and Amuc IV was mainly distributed in western populations. A large number of gene of functions, pathways, and carbohydrate active enzymes that specifically associated to phylogroups. Our findings based on over a thousand genomes strengthened the previous knowledge and provided new insights into the population structure and ecology of Akkermansia in human gut.

Objective Alzheimer’s disease (AD) is a global health problem without effective methods to alleviate the disease progression. Amyloid β-protein (Aβ) is widely accepted as a key biomarker for AD. Metabolic syndromes, including obesity and insulin resistance, are key high risk factors for AD. Akkermansia muciniphila (Akk), the only representative human gut microbe in the genus Verrucomicrobia, can prevent the weight gain caused by a high-fat diet, repair the damaged integrity of the intestinal epithelium barrier, reduce endotoxin levels in blood and improve insulin resistance. The aim of this study is to explore the impact of Akk administration in AD model mice in different diets. Methods APP/PS1 mice were fed either a normal chow diet or a high-fat diet and were treated with Akk by gavage each day for 6 months. The impacts of Akk on glucose metabolism, intestinal barrier and lipid metabolism in the mouse model of AD were determined. Changes in brain pathology and neuroethology were also analyzed. Results Akk effectively reduced the fasting blood glucose and serum diamine oxidase levels, and alleviated the reduction of colonic mucus cells in APP/PS1 mice. After treatment with Akk, the APP/PS1 mice showed obviously reduced blood lipid levels, improved hepatic steatosis and scapular brown fat whitening. Moreover, Akk promoted the reduction of Aβ 40–42 levels in the cerebral cortex of APP/PS1 mice, shortened the study time and improved the completion rate in Y-maze tests. Conclusion Akk effectively improved glucose tolerance, intestine barrier dysfunction and dyslipidemia in AD model mice. Our study results suggested that Akk could delay the pathological changes in the brain and relieve impairment of spatial learning and memory in AD model mice, which provides a new strategy for prevention and treatment of AD., APP/PS1 mice display alterations in physiological processes after treated with Akk. It is showed that the damaged integrity of the intestinal epithelium barrier is repaired, leading to obviously reduced blood glucose and lipid levels, improved hepatic steatosis, insulin resistance and scapular brown fat whitening, which are beneficial to reduce Aβ 40–42 levels in the brain of APP/PS1 mice.

Objective This study aimed to identify the pathogenic mutation in a Chinese family with unexplained sudden death (USD) or occasional syncope. Materials and methods Whole exome sequencing and target capture sequencing were respectively conducted for two related patients. The genetic data was screened using the 1000 genomes project and SNP database (PubMed), and the identified mutations were assessed for predicted pathogenicity using the SIFT and Polyphen-2 algorithms. Results We identified a heterozygous mutation in the RYR2 gene at c.490C > T (p.P164S), highly conserved across all species, in three family members of USD, syncope and malignant ventricular tachycardias induced by treadmill exercise test, while another heterozygous de novo mutation in SCN5A at c.5576G > A p.R1859H was detected in one family member. Both variants were verified by Sanger sequencing. Importantly, RYR2 p.P164S is associated with the risk of sudden cardiac death, such as in catecholaminergic polymorphic ventricular tachycardia. Conclusions A pathogenic mutation in RYR2 (p.P164S) is the likely cause of USD in a Chinese family associated with malignant ventricular arrhythmias. Whole exome and target capture sequencing can be useful for discovering the genetic causes of USD.

Phascolarctobacterium can produce short-chain fatty acids, including acetate and propionate, and can be associated with the metabolic state and mood of the host. The present study investigated the colonization characteristics of Phascolarctobacterium faecium in healthy individuals 1 year old). The permillage of Phascolarctobacterium faecium in total bacteria ranged between 0.004–1.479. There was presence of Phascolarctobacterium faecium-like bacteria in younger individuals with a gradual increase in the number of bacteria maintained at a high level with increasing ages (between 1 and 60 years old), but with a decrease in elderly individuals (>60 years old). The results of the present study demonstrated that Phascolarctobacterium faecium is abundantly colonized in the human gastrointestinal tract.

Background The study aimed to investigate the differences of different Akkermansia muciniphila (A.muciniphila) genotypes on metabolic protective effects in mice with high-fat diet and explore possible mechanisms. Methods Male C57BL/6 mice were randomly divided into 6 groups, including high-fat diet (HFD)+ A.muciniphila I/II/PBS group, normal chow diet (NCD)+A.muciniphila I/ II /PBS group, respectively. Dietary intervention and A.muciniphila gavage were performed simultaneously. Blood glucose and lipid metabolism, brown adipose morphology and activities, and intestinal barrier function were examined after the mice were sacrificed. Results A.muciniphila gavage improved the impaired glucose tolerance, hyperlipidemia and liver steatosis in HFD mice, and that A.muciniphila II was not as effective as A.muciniphila I. This phenomenon might be because A.muciniphila I intervention significantly inhibited brown adipose tissue whitening and inflammation induced by HFD, by repairing the intestinal barrier and relieving endotoxemia. A.muciniphila II did not display the same results as A.muciniphila I in HFD mice, but had stronger effects in the NCD mice. Conclusions This study mainly reveals the distinct functions of different A.muciniphila genotypes on diet-induced obesity, suggesting that different A.muciniphila genotypes may play inequitable roles in pathological conditions through distinct action pathways.

The prevalence of obesity and diabetes, and their complicating mental disorders, severely affect public health. This study aimed to investigate the long-term effects of an Akkermansia muciniphila subtype (A. muciniphilasub) on high-fat diet-induced obesity and diabetes, and to evaluate whether this subtype can alleviate their complicated mental disorders. Whole genome sequencing and short chain fatty acid production analysis in supernatant of pure culture were performed. Female adult C57BL/6 mice were fed a high-fat diet or a normal chow diet and were gavaged with A. muciniphilasub or phosphate-buffered saline daily for 10 months. Body weight, food consumption and blood glucose were measured. At the end of the treatment period, all mice were subjected to the Y-maze test, sucrose preference test, analyses of serum, fecal microbiota analysis and histological examination. This A. muciniphilasub had 278 unique genes compared to the type strain (A. muciniphila ATCC BAA-835) and produced short chain fatty acids both. A. muciniphilasub administration significantly reduced body weight gain and improved the spatial memory of high-fat diet-fed mice. A. muciniphilasub increased Nissl bodies in neurons of the hippocampus, and restored the high-fat diet-inhibited tryptophan metabolism. The high-fat diet led to decreased serum 5-hydroxytryptamine and induced depression, which were not alleviated by A. muciniphilasub. A. muciniphilasub increased the relative fecal abundance of Bifidobacterium, and was negatively correlated with the fecal abundance of Bacteroides. The present study demonstrated the beneficial effects of this A. muciniphilasub on body weight, blood glucose control and the alleviation of the memory decay caused by a high-fat diet in mice.

Background Akkermansia muciniphila is one of the most dominant bacteria that resides on the mucus layer of intestinal tract and plays key role in human health, however, little is known about its genomic content. Results Herein, we for the first time characterized the genomic architecture of A. muciniphila based on whole-genome sequencing, assembling, and annotating of 39 isolates derived from human and mouse feces. We revealed a flexible open pangenome of A. muciniphila currently consisting of 5644 unique proteins. Phylogenetic analysis identified three species-level A. muciniphila phylogroups exhibiting distinct metabolic and functional features. Based on the comprehensive genome catalogue, we reconstructed 106 newly A. muciniphila metagenome assembled genomes (MAGs) from available metagenomic datasets of human, mouse and pig gut microbiomes, revealing a transcontinental distribution of A. muciniphila phylogroups across mammalian gut microbiotas. Accurate quantitative analysis of A. muciniphila phylogroups in human subjects further demonstrated its strong correlation with body mass index and anti-diabetic drug usage. Furthermore, we found that, during their mammalian gut evolution history, A. muciniphila acquired extra genes, especially antibiotic resistance genes, from symbiotic microbes via recent lateral gene transfer. Conclusions The genome repertoire of A. muciniphila provided insights into population structure, evolutionary and functional specificity of this significant bacterium. Electronic supplementary material The online version of this article (10.1186/s12864-017-4195-3) contains supplementary material, which is available to authorized users.

Orf virus (ORFV) is a typical member of the genus Parapoxvirus. The parapoxvirus genome consists of highly variable terminal regions and relatively conserved central regions with a high G + C content. In our previous study, a novel ORFV strain, NA1/11, was isolated from northeastern China. To fully characterize this strain, we sequenced the entire genome of NA1/11 and conducted a comparative analysis using multiple parapoxviruses. The genomic sequence of NA1/11 was found to consist of 137,080 nucleotides with a G + C content of 63.6 %, but it did not contain the terminal hairpin sequence. Alignment of ORFs from NA1/11 with NZ2, IA82 and SA00 revealed several highly variable ORFs, while the most evident ones are ORFs 001, 103, 109-110, 116 and 132. An odd phenomenon in the region of ORFs 118-120 is that the non-coding fragments are almost as long as the coding fragments. By comparative analysis of inverted terminal repeats, we identified one repeat motif and a long conserved fragment. By comparing the ITRs of SA00 with those of three other ORFVs, more clues were obtained about the correlation between ITR sequence and host adaption. Comparison of the NA1/11 genome with the sequences of other strains of ORFV revealed highly variable regions, thus providing new insights into the genetic diversity of ORFV.

Isolation, sequencing, assembly and gene prediction information of 39 A. muciniphila isolates and strain ATCC BAA-835. (XLSX 16 kb)

To construct a universal, highly attenuated orf virus expression vector for exogenous genes using green fluorescent protein (GFP) as the reporter gene.The flanking regions of the ORFV132 of orf virus DNA were amplified by PCR to construct the shuttle plasmid pSPV-132LF-EGFP-132RF. The shuttle plasmid was transfected into OFTu cells and GFP was incorporated into orf virus IA82Delta 121 by homologous recombination. The recombinant IA82Delta121-V was selected by green fluorescent signal. The deletion gene was identified by PCR and sequencing. The effects of ORFV132 knockout were evaluated by virus titration and by observing the proliferation of the infected vascular endothelial cells in vitro.The recombinant orf virus IA82Delta121-V was obtained successfully and quickly, and the deletion of ORFV132 did not affect the replication of the virus in vitro but reduced its virulence.Green fluorescent protein is a selectable marker for rapid, convenient and stable selection of the recombinant viruses. Highly attenuated recombinant orf virus IA82Delta121-V can serve as a new expression vector for exogenous genes.

Aim This study investigates the colonization rate of Akkermansia muciniphila in the gastrointestinal tracts of people living in southern China and applies a modified method for the isolation and subtyping of A. muciniphila strains from faecal samples. Methods and Results Fresh faecal samples were collected and bacterial DNA was extracted from these samples for real-time PCR analysis. Strains were separated using a culture-dependent sPCR-directed method and classified using an enterobacterial repetitive intergenic consensus (ERIC-PCR) DNA fingerprinting method. The colonization rate for the sample population from southern China was 51·74%. We isolated 22 strains from human faeces. The results revealed that all strains were identifiable as A. muciniphila with 99–100% identity to the type-strain ATCC BAA-835. ERIC-PCR resulted in grouping of the DNA fingerprints showed that 12 distinct clusters were distinguished with a delineation level of 100%. Conclusions Southern China has a high rate of A. muciniphila colonization and over 12 different subtype strains reside in faecal samples. Significance and Impact of the Study Akkermansia muciniphila has a beneficial role in human gastrointestinal tract. These studies provide a better understanding of A. muciniphila and details of its colonization in the human gastrointestinal tract.

To perform cytogenetic analysis for children, especially newborns suspected for chromosome abnormalities.Peripheral blood or born marrow specimens were respectively cultured in proper media. Karyograms were analyzed following G-banding.Of 154 blood specimens, numerical chromosomal abnormalities were identified in 20 patients, which included 19 with trisomy 21. Structural aberrations were identified in 13 patients, among which chromosome 9 aberrations were seen in 6 cases. These included 3 inversions, 1 deletion, 1 insertion and 1 duplication. All aberrations were located in pericentromere region of chromosome 9 with clinical manifestations including congenital heart disease, peculiar facial appearance, paralysis, dysplasia and/or movement disorder. Chromosome polymorphisms were found in 20 patients, most of which had absence of satellites or variation of heterochromatin on chromosome 9. Of 10 bone marrow specimens from children suspected for acute leukemia, chromosome abnormalities were identified in 5 patients.Cytogenetic analysis is useful for children featuring multiple congenital abnormalities. Chromosome 9 abnormalities and their clinical relevance should attract more attention.

Background Reporter genes are often used as a selectable marker for generation of recombinant viruses in order to investigate the mechanism of pathogenesis and to obtain candidate vaccine viruses. Routine selection of the recombinant parapoxvirus is time-consuming and labor intensive. Therefore, developing a novel method for selection is critical. Results In this study, we developed a rapid method to generate recombinant Orf viruses (ORFV) based on the enhanced green fluorescent protein (EGFP) reporter gene as a selectable marker. The coding sequence of EGFP gene was amplified from pEGFP-N1 vector and subcloned into the pZIPPY-neo/gus plasmid under the control of the early-late vaccinia virus (VACV) VV7.5 promoter and flanked by two multiple cloning sites (MCS) to generate a novel transfer vector pSPV-EGFP. Using the pSPV-EGFP, two recombination cassettes pSPV-113LF-EGFP-113RF and pSPV-116LF-EGFP-116RF were constructed by cloning the flanking regions of the ORFV113 and ORFV116 and inserted into two MCS flanking the EGFP gene. Using this novel system, two single gene deletion mutants OV-IA82Δ113 and OV-IA82Δ116 were successfully generated. Conclusions This approach shortens the time needed to generate recombinant ORFVs (rORFVs). Thus, the pSPV-EGFP vector provides a direct, fast, and convenient way to manipulate the recombinant viruses, indicating that it is highly suited for its designed purpose.

In this study, we analyzed the diversity of vaginal microbiota in 9 bacterial vaginosis (BV) positive and 11 healthy women from the metropolitan area of Guangzhou in Southern China using full-length 16S rDNA. Our data confirmed that a shift in the abundance of bacterial species present in the vaginal environment comparing the BV and non-BV groups. Each sequence read was assigned to a genus or a species when possible. Principal component analysis was performed at genus levels. Most BV+ samples clustered together while there were two clusters among the BV- samples. Several bacteria have been found to be highly associated with BV, including Gardnerella, Atopobium, Megasphaera, Leptotrichia/Sneathia, and Prevotella. We found that the presence of any BV-associated organisms alone did not necessary cause BV. We identified several additional non-lactobacillus bacteria associated with BV, including a Coriobacteriaceae bacterium and a Ruminococcaceae bacterium. Our results showed that analysis of vaginal microbiota and the clustering of microbial profile could help identification of bacterial vaginosis and assessment of women's vaginal health. The presence or absence of certain bacterial species is not adequate for disease diagnosis; rather the prevalence of multiple organisms collectively should be used as markers for a microbial diagnosis of BV.