Down's syndrome (DS), a common chromosomal disease caused by chromosome 21 trisomy, is the main cause of cognitive impairment in children worldwide. Emerging evidence suggests that the microbiota–gut–brain axis plays a potential role in cognitive impairment. However, data regarding gut microbiota alterations in DS patients remain scarce, especially data from children with DS. This case–control study was conducted to explore the gut microbiota composition in Chinese DS children. Additionally, the potential association between gut microbiota and cognitive function in DS was evaluated. Microbiota communities in the feces of 15 DS subjects and 15 matched controls were investigated using high-throughput Illumina Miseq sequencing targeting the V3–V4 region of 16S rRNA gene. The relationships between gut microbiota composition and DS cognitive function scores were analyzed. The structure and richness of the gut microbiota differed between DS patients and healthy controls. The abundance of Acidaminococcaceae was decreased in DS patients. Moreover, the Kyoto Encyclopedia of Genes and Genomes analysis showed increased modules related to peptidases and pyrimidine metabolism. Overall, we confirmed that gut microbiota alterations occurred in Chinese patients with DS. Additionally, the fecal microbiota was closely related to DS cognitive impairment. Larger cohorts are needed to confirm these findings and to clarify the mechanisms involved. Elucidating these novel findings in the field of microbiota-gut-brain axis will provide a promising strategy for future studies of DS cognitive impairment.

Introduction: Down syndrome (DS), the presence of a supernumerary chromosome 21, is associated with cognitive dysfunction caused by early neurodegenerative processes. Alterations in the gut microbiota were observed in Chinese children with DS, and the genus Blautia was associated with cognitive function in these children. Therefore, it is crucial to understand the detailed composition of this group at the species level and to explore the effect of specific species on cognitive function.Methods: In this study, Blautia-specific amplicon sequencing was conducted to identify the specific Blautia species in 15 children with DS and 15 matched healthy children.Results: The taxonomic analyses suggested that the Blautia taxa were clustered by disease status. The diversity of Blautia at the species level differed between DS patients and healthy controls, with the abundances of Blautia massiliensis and Blautia argi decreasing in DS children, while Blautia faecis was increased. Acetic acid, one of the metabolites of Blautia, was significantly reduced in the DS group. Of particular interest, Kyoto Encyclopaedia of Genes and Genomes analysis revealed decreased modules related to starch and sucrose metabolism and glycolysis. In addition, B. argi was positively related to DS cognitive scores, and B. faecis was negatively related to cognitive function, implying its role on the DS cognitive impairments. Discussion: Our study has important implications for understanding the important effects of specific species of Blautia on cognitive function and thus possibly provides a new strategy for future studies of cognitive improvement in individuals with DS.

Background: Increasing evidence suggests that lncRNA (Long non‐coding RNA, lncRNA)‐mediated ceRNA (competing endogenous RNA, ceRNA) networks are involved in the occurrence and progression of colorectal cancer (CRC). However, the roles of the lncRNA–miRNA–mRNA ceRNA network in distant metastasis of CRC are still unclear.Methods: In this study, we constructed a specific ceRNA network to identify potential biomarkers and therapeutic targets for distant metastasis of CRC. Specifically, RNA‐Seq data from The Cancer Genome Atlas (TCGA) were used to screen for differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) related to metastasis. After validation and selection by qRT–PCR and univariate and multivariate analysis of the metastasis‐ and prognosis‐related lncRNAs, the regulated microRNAs (miRNAs) and coexpressed mRNAs were used to construct a ceRNA network for distant metastasis of CRC.Results: Two key distant metastasis‐related DElncRNAs, AP002498.1 and LINC01871, were identified by univariate and multivariate analysis in combination with analyses of clinical data and expression levels. Furthermore, lncRNA‐associated ceRNA subnetworks were constructed from the predicted miRNAs and 13 coexpressed DEmRNAs (SERPINA1, ITLN1, REG4, L1TD1, IGFALS, MUC5B, CIITA, CXCL9, CXCL10, GBP4, GNLY, IDO1, and NOS2). The AP002498.1‐ and LINC01871‐associated ceRNA subnetworks regulated the expression of the target genes SERPINA1 and MUC5B and GNLY, respectively, through the associated miRNAs.Conclusion: The DElncRNA AP002498.1 and the LINC01871/miR‐4644 and miR‐185‐5p/GNLY axes were identified as being closely associated with distant metastasis and could represent independent prognostic biomarkers or therapeutic targets in colorectal adenocarcinoma.

Histone acetylation and mitochondrial function contribute importantly to neural differentiation, which is critically associated with neurodevelopmental disorders such as Down Syndrome (DS). However, whether and how histone acetylation regulates mitochondrial function and further affects neural differentiation has not been well described. In this study, when treated with retinoid acid (RA), the human neuroblastoma SH-SY5Y cell line was used as a neural differentiation model. We found that the acetylation of histone H3, especially H3 lysine 14 acetylation (H3K14ac), and mitochondrial function, including biogenesis and electron transport chain, were enhanced during neural differentiation. Specific inhibition of histone acetyltransferases (HATs) induced neural differentiation deficits, accompanied by downregulation of mitochondrial function. Furthermore, RA receptors (RARs) interacting with HATs were involved in the increased H3K14ac and the enhanced mitochondrial function during the neural differentiation process. Finally, receptor-interacting protein 140 (RIP140), a co-repressor of RARs, was also involved in regulating histone acetylation. RIP140 overexpression inhibited histone acetylation and mediated negative feedback on target genes which are involved in RA signaling. These findings evidenced that when interacting with RARs which had been negatively regulated by RIP140, RA promoted neural differentiation by promoting H3K14ac and enhanced mitochondrial function. This provides a molecular foundation for further investigations into abnormal neural development.