Dynamic Changes in Gut Microbiome of Ulcerative Colitis: Initial Study from Animal Model.

Background: An animal model of DSS-induced UC has been widely used in basic research, and the dysbiosis of gut microbiome is one of the important pathogenetic mechanisms of DSS-induced UC, but its dynamic changes and correlation with inflammatory factors are not clear yet. Methods: Clinical signs and tissue damage degree of C57BL/6 ulcerative colitis mice model induced by different concentrations of DSS were compared with that of normal mice, and finally the optimal concentration of DSS was determined. Then we analyzed the sequencing results of gut microbiome and inflammatory factors to determine the dynamic patterns of gut microbiome and their correlation with the inflammatory factors. Results: DSS at 2.5% and 3.0% concentration could cause intestinal injury and induce colitis. However, 3.0% DSS resulted in higher mortality. In addition, there were dynamic changes of gut microbiome in DSS-induced UC model: the relative abundance of intestinal flora increased first and then decreased in Bacteroides, Parabacteroides, Romboutsia, Clostridium_sensu_stricto_1, Lachnospiraceae_NK4A136_group, norank_f_norank_o_Clostridia_UCG-014, Parasutterella, and decreased first and then increased in Lactobacillus, Muribaculum, norank_f_Muribaculaceae, in addition, Bifidobacterium, Coriobacteriaceae_UCG-002 and Enterorhabdus did not change in the first 14 days but increased significantly on day 21. Moreover, inflammatory cytokines were closely associated with the imbalance of the intestinal microbiota in mice with UC: most pathogenic bacteria in the intestinal tract of the UC animal model were positively correlated with pro-inflammatory factors and negatively correlated with anti-inflammatory factors, while beneficial bacteria were the opposite. Conclusion: Intestinal microecology plays an important role in DSS-induced UC model, and the relative abundance of gut microbiome changes dynamically in the occurrence and development of ulcerative colitis.

Mussel-inspired bioactive 3D-printable poly(styrene-butadiene-styrene) and the in vitro assessment of its potential as cranioplasty implants.

Challenges in cranial defect reconstruction after craniotomy arise from insufficient osteogenesis and biofilm infection, which requires novel biomaterials. Herein, we propose a mussel-inspired bioactive poly(styrene-butadiene-styrene) (SBS) as a promising cranioplasty material. The catechol-modified quaternized chitosan (QCSC) was employed in the bio-inert surface of 3D-printed SBS to provide the contact-killing ability against bacterial biofilms. The polydopamine-decorated zeolitic imidazolate framework-8 (pZIF-8) and polydopamine hybrid hydroxyapatite (pHA) were further modified on the surface to further enhance the antibacterial property and osteogenesis activity, effectively killing bacteria by no less than two orders of magnitude and significantly facilitating osteogenic gene expression and mineralization. Due to the lack of research using SBS as a cranioplasty material, we believe that the modified SBS materials developed in this study and the in vitro assessment may be beneficial for developing novel cranioplasty implants.

[Effect of Banxia Xiexin Decoction on intestinal flora of mice with ulcerative colitis induced by dextran sodium sulfate].

The aim of this paper was to investigate the effect of Banxia Xiexin Decoction(BXD) on inflammatory factors and intestinal flora in a dextran sulfate sodium induced ulcerative colitis(DSS-UC) mouse model, and to explore the mechanism of BXD in treating ulcerative colitis from the perspective of flora disorder. Forty C57 BL/6 J mice were randomly divided into control group, model group and BXD group. A 2.5% DSS-induced ulcerative colitis model was established. On the 8 th day, normal saline, normal saline, and BXD were given daily for 14 days. After 14 days, HE staining was used to observe histopathological changes of the colon. Serum inflammatory factor content was detected by ELISA, and the change of intestinal flora in mice feces was detected by 16 S rRNA sequencing technology. Compared with control group, the colonic tissue of mice in model group was damaged seriously, and the contents of IL-6 and TNF-α in serum were significantly increased(P<0.05). Compared with model group, mice in BXD group had less colonic damage, and the contents of IL-6, TNF-α in serum were decreased significantly(P<0.05). After creation, the richness of Patescibacteria was increased significantly at the phylum level(P<0.05). At the same time, the richness of Faecalibaculum(P<0.01), norank_f_Muribaculaceae(P<0.01) were decreased significantly at the genus level, while the richness of Turicibacter(P<0.01), Romboutsia(P<0.01), Clostridium_sensu_stricto_1(P<0.01) were increased significantly. After the intervention with BXD, the content of Patescibacteria was significantly reduced at the phylum level(P<0.05), and the contents of Lactobacillus(P<0.01), Clostri-dium_sensu_stricto_1(P<0.01), Enterorhabdus(P<0.01), Candidatus_Saccharimonas(P<0.05), Eubacterium_fissicatena_group(P<0.05) were decreased significantly at the genus level, while the contents of Dubosiella, Bacteroides and Allobaculum were increased significantly. Therefore, BXD could significantly improve the symptoms of DSS-UC mice. It not only could reduce the contents of IL-6 and TNF-α, but also could reduce the richness of Patescibacteria at the phylum level, and those of Clostridium_sensu_stricto_1, Candidatus_Saccharimonas, Eubacterium_fissicatena_group at the genus level. Inaddition, BXD could increase the richness of Bacteroides and Bifidobacterium. It suggested that BXD could play a role in the treatment of ulcerative colitis partially through reducing inflammatory factors and regulating the structure of the gut microbiota.

Urine metabolomics of rats with chronic atrophic gastritis.

BACKGROUND/AIM: To use liquid chromatography-mass spectrometry (LC-MS) to identify endogenous differential metabolites in the urine of rats with chronic atrophic gastritis (CAG). MATERIALS AND METHODS: Methylnitronitrosoguanidine (MNNG) was used to produce a CAG model in Wistar rats, and HE staining was used to determine the pathological model. LC-MS was used to detect the differential metabolic profiles in rat urine. Diversified analysis was performed by the statistical method. RESULTS: Compared with the control group, the model group had 68 differential metabolites, 25 that were upregulated and 43 that were downregulated. The main metabolic pathways were D-glutamine and D-glutamic acid metabolism, histidine metabolism and purine metabolism. CONCLUSION: By searching for differential metabolites and metabolic pathways in the urine of CAG rats, this study provides effective experimental data for the pathogenesis and clinical diagnosis of CAG.

Genetic analysis and major quantitative trait locus mapping of leaf widths at different positions in multiple populations.

BACKGROUND: Leaf width is an important agricultural trait in maize. Leaf development is dependent on cell proliferation and expansion, and these processes exhibit polarity with respect to the longitudinal and transverse axes of the leaf. However, the molecular mechanism of the genetic control of seed vigor remains unknown in maize, and a better understanding of this mechanism is required. METHODOLOGY/PRINCIPAL FINDINGS: To reveal the genetic architecture of leaf width, a comprehensive evaluation using four RIL populations was performed, followed by a meta-analysis. Forty-six QTLs associated with the widths of leaves at different positions above the uppermost ear were detected in the four RIL populations in three environments. The individual effects of the QTLs ranged from 4.33% to 18.01% of the observed phenotypic variation, with 14 QTLs showing effects of over 10%. We identified three common QTLs associated with leaf width at all of the examined positions, in addition to one common QTL associated with leaf width at three of the positions and six common QTLs associated with leaf width at two of the positions. The results indicate that leaf width at different leaf positions may be affected by one QTL or several of the same QTLs. Such traits may also be regulated by many different QTLs. Thirty-one of the forty-six initial QTLs were integrated into eight mQTLs through a meta-analysis, and 10 of the 14 initial QTLs presenting an R2>10% were integrated into six mQTLs. CONCLUSIONS/SIGNIFICANCE: mQTL1-2, mQTL3-1, mQTL7, and mQTL8 were composed of the initial QTLs showing an R2>10% and included four to six of the initial QTLs that were associated with two to four positions in a single population. Therefore, these four chromosome regions may be hot spots for important QTLs for these traits. Thus, they warrant further studies and may be useful for marker-assisted breeding.

Dissection of the genetic architecture underlying the plant density response by mapping plant height-related traits in maize (Zea mays L.).

Plant height is one of the most heritable traits in maize (Zea mays L.). Understanding the genetic control of plant height is important for elucidating the molecular mechanisms that regulate maize development. To investigate the genetic basis of the plant height response to density in maize, we evaluated the effects of two different plant densities (60,000 and 120,000 plant/hm(2)) on three plant height-related traits (plant height, ear height, and ear height-to-plant height ratio) using four sets of recombinant inbred line populations. The phenotypes observed under the two-plant density treatments indicated that high plant density increased the phenotypic performance values of the three measured traits. Twenty-three quantitative trait loci (QTLs) were detected under the two-plant density treatments, and five QTL clusters were located. Nine QTLs were detected under the low plant density treatment, and seven QTLs were detected under the high plant density treatment. Our results suggested that plant height may be controlled mainly by a common set of genes that could be influenced by additional genetic mechanisms when the plants were grown under high plant density. Fine mapping for genetic regions of the stable QTLs across different plant density environments may provide additional information about their different responses to density. The results presented here provide useful information for further research and will help to reveal the molecular mechanisms related to plant height in response to density.

Genetic dissection of internode length above the uppermost ear in four RIL populations of maize (Zea mays L.).

The internode length above the uppermost ear (ILAU) is an important influencing factor for canopy architecture in maize. Analyzing the genetic characteristics of internode length is critical for improving plant population structure and increasing photosynthetic efficiency. However, the genetic control of ILAU has not been determined. In this study, quantitative trait loci (QTL) for internode length at five positions above the uppermost ear were identified using four sets of recombinant inbred line (RIL) populations in three environments. Genetic maps and initial QTL were integrated using meta-analyses across the four populations. Seventy QTL were identified: 16 in population 1; 14 in population 2; 25 in population 3; and 15 in population 4. Individual effects ranged from 5.36% to 26.85% of phenotypic variation, with 27 QTL >10%. In addition, the following common QTL were identified across two populations: one common QTL for the internode length of all five positions; one common QTL for the internode length of three positions; and one common QTL for the internode length of one position. In addition, four common QTL for the internode length of four positions were identified in one population. The results indicated that the ILAU at different positions above the uppermost ear could be affected by one or several of the same QTL. The traits may also be regulated by many different QTL. Of the 70 initial QTL, 46 were integrated in 14 meta-QTL (mQTLs) by meta-analysis, and 17 of the 27 initial QTL with R(2) >10% were integrated in 7 mQTLs. Four of the key mQTLs (mQTL2-2, mQTL3-2, mQTL5-1, mQTL5-2, and mQTL9) in which the initial QTL displayed R(2) >10% included four to 11 initial QTL for an internode length of four to five positions from one or two populations. These results may provide useful information for marker-assisted selection to improve canopy architecture.

QTLs for seed vigor-related traits identified in maize seeds germinated under artificial aging conditions.

High seed vigor is important for agricultural production due to the associated potential for increased growth and productivity. However, a better understanding of the underlying molecular mechanisms is required because the genetic basis for seed vigor remains unknown. We used single-nucleotide polymorphism (SNP) markers to map quantitative trait loci (QTLs) for four seed vigor traits in two connected recombinant inbred line (RIL) maize populations under four treatment conditions during seed germination. Sixty-five QTLs distributed between the two populations were identified and a meta-analysis was used to integrate genetic maps. Sixty-one initially identified QTLs were integrated into 18 meta-QTLs (mQTLs). Initial QTLs with contribution to phenotypic variation values of R(2)>10% were integrated into mQTLs. Twenty-three candidate genes for association with seed vigor traits coincided with 13 mQTLs. The candidate genes had functions in the glycolytic pathway and in protein metabolism. QTLs with major effects (R(2)>10%) were identified under at least one treatment condition for mQTL2, mQTL3-2, and mQTL3-4. Candidate genes included a calcium-dependent protein kinase gene (302810918) involved in signal transduction that mapped in the mQTL3-2 interval associated with germination energy (GE) and germination percentage (GP), and an hsp20/alpha crystallin family protein gene (At5g51440) that mapped in the mQTL3-4 interval associated with GE and GP. Two initial QTLs with a major effect under at least two treatment conditions were identified for mQTL5-2. A cucumisin-like Ser protease gene (At5g67360) mapped in the mQTL5-2 interval associated with GP. The chromosome regions for mQTL2, mQTL3-2, mQTL3-4, and mQTL5-2 may be hot spots for QTLs related to seed vigor traits. The mQTLs and candidate genes identified in this study provide valuable information for the identification of additional quantitative trait genes.