Effect of whole-plant corn silage treated with lignocellulose-degrading bacteria on growth performance, rumen fermentation, and rumen microflora in sheep.

Lignification of cellulose limits the effective utilisation of fibre in plant cell wall. Lignocellulose-degrading bacteria secrete enzymes that decompose lignin and have the potential to improve fibre digestibility. Therefore, this study aimed to investigate the effect of whole-plant corn silage inoculated with lignocellulose-degrading bacteria on the growth performance, rumen fermentation, and rumen microbiome in sheep. Twelve 2-month-old male hybrid sheep (Dorper ♂ × small-tailed Han ♀) were randomly assigned into two dietary groups (n = 6): (1) untreated whole-plant corn silage (WPCS) and (2) WPCS inoculated with bacterial inoculant (WPCSB). Whole-plant corn silage inoculated with bacterial inoculant had higher in situ NDF digestibility than WPCS. Sheep in the WPCSB group had significantly higher average daily gain, DM intake, and feed conversion rate than those in the WPCS group (P < 0.05). Furthermore, higher volatile fatty acid concentrations were detected in WPCSB rumen samples, leading to lower ruminal pH (P < 0.05). The WPCSB group showed higher abundance of Bacteroidetes and lower abundance of Firmicutes in the rumen microbiome than the WPCS group (P < 0.05). Multiple differential genera were identified, with Prevotella being the most dominant genus and more abundant in WPCSB samples. Moreover, the enriched functional attributes, including those associated with glycolysis/gluconeogenesis and citrate cycle, were more actively expressed in the WPCSB samples than in the WPCS samples. Additionally, certain glucoside hydrolases that hydrolyse the side chains of hemicelluloses and pectins were also actively expressed in the WPCSB microbiome. These findings suggested that WPCSB increased NDF digestibility in three ways: (1) by increasing the relative abundance of the most abundant genera, (2) by recruiting more functional features involved in glycolysis/gluconeogenesis and citrate cycle pathways, and (3) by increasing the relative abundance and/or expression activity of the glucoside hydrolases involved in hemicellulose and pectin metabolism. Our findings provide novel insights into the microbial mechanisms underlying improvement in the growth performance of sheep/ruminants. However, the biological mechanisms cannot be fully elucidated using only metagenomics tools; therefore, a combined multi-omics approach will be used in subsequent studies.

[Chordoid glioma: a clinicopathological study].

Objective: To analyze the clinicopathological features of chordoid glioma. Methods: A total of 12 cases of chordoid gliomas from 2009 to 2020 in Xuanwu Hospital of Capital Medical University and General Hospital of Chinese People's Liberation Army were retrospectively analyzed. The clinical and imaging characteristics, pathologic and molecular characteristics were analyzed, and the relevant literature was reviewed. Results: All 12 patients (4 males and 8 females) aged from 25 to 67 years (mean 39 years) and mainly had a history of headache or/and vision loss. MRI showed that the lesions located in the third ventricle, and they showed abnormal enhancement. Pathologically, these 12 cases displayed the morphologic characteristics of chordoid gliomas, including papillary structures in two cases. Immunohistochemically, GFAP and vimentin were expressed in all 12 cases (12/12). TTF1 was also expressed in all cases (10/10). CD34 and CKpan were seen in 11 cases (11/12). EMA with dot-and/or-ring like positivity was seen in 9 cases (9/10). Tissues were available in nine chordoid gliomas for Sanger sequencing to detect PRKCA and IDH gene mutation, and eight cases (8/9) showed PRKCA gene D463H mutation. None of these cases showed IDH1 R132 and IDH2 R172 mutation. All 12 patients underwent surgery, and four were lost to follow up. The remaining eight patients were progression or recurrence free at last follow-up in January 2021. Conclusions: Chordoid gliomas have relatively distinguishing clinical and histopathological features. PRKCA gene mutation in chordoid gliomas can be considered as a biomarker for the diagnosis and differential diagnosis of chordoid gliomas, and may provide a direction for future targeted therapy.

[miR-449a is a potential epigenetic biomarker for WNT subtype of medulloblastoma].

Objective: To identify the candidate epigenetic biomarkers of Wnt subtype of medulloblastoma(MB). Methods: MicroRNAs(miRNAs) expression array was used to detect the expression of miRNAs in MB cell lines with or without treatment by demethylation reagent. Nanostring gene expression array was used to detect the expression level of mRNA in 45 samples of primary MB. Molecular subtyping was performed based on the NanoString data. The status of methylation was confirmed by methylation specific PCR. The expression of candidate miRNA was confirmed by real-time PCR. Results: All 45 MBs except one were classified into the four molecular groups: 4 in WNT group, 8 in SHH group, 16 were in Group3 and 16 in Group4. Methylation specific PCR (MSP) assay confirmed miR-449a was silenced due to aberrant DNA methylation in MB cell lines.WNT subtype of MBs showed relatively higher expression of miR-449a comparing with other subgroups. Conclusion: MiR-449a, a candidate tumor suppressor gene regulated by hypermethylation, is a novel potential epigenetic marker for WNT subtype of MBs.