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Objective The aim of this study was to investigate the gut microbial signatures and related pathophysiological implications in patients with Cushing's disease (CD). Design and methods Twenty-seven patients with CD and 45 healthy controls were enrolled. Based on obtained metagenomics data, we performed correlation, network study, and genome interaction group (GIG) analysis. Fecal metabolomics and serum enzyme linked immunosorbent assay (ELISA) analysis were conducted in dichotomized CD patients. Caco-2 cells were incubated with gradient concentrations of cortisol for subsequent transepithelial electrical resistance (TEER) measurement, FITC-dextran transwell permeability assay, qPCR, and western blot analysis. Results Gut microbial composition in patients with CD was notably different from that in healthy controls. Network analysis revealed that Eubacterium siraeum might serve as the core specie in the gut microbial system of CD patients. Subsequent GIG analysis identified the positive correlations between GIG9 and UFC. Further serum ELISA and fecal metabolomics uncovered that CD patients with elevated UFC levels were characterized with increased lipopolysaccharide binding protein (LBP). Moreover, remarkable positive association was found between LBP level and relative abundance of E. siraeum. TEER and FITC-dextran transwell assays demonstrated that hypercortisolism induced increased gut permeability. Further qPCR and western blot analysis suggested that dysregulated AhR/Claudin 2 axis might be involved in the development of hypercortisolism-induced defective gut barrier function Conclusions Disease activity associated dysbiosis and defective gut barrier might jointly facilitate the development of systemic inflammation in patients with CD. [ABSTRACT FROM AUTHOR]

Craniopharyngioma (CP) is an intracranial tumor with high mortality and morbidity. Though biologically benign, CP will damage the hypothalamus, inducing comorbidities such as obesity, metabolic syndrome, and cognitive impairments. The roles of gut microbiome and serum metabolome in CP‐associated hypothalamic comorbidities are aimed to be explored. Patients with CP are characterized by increased Shannon diversity, Eubacterium, Clostridium, and Roseburia, alongside decreased Alistipes and Bacteroides. CP‐enriched taxa are positively correlated with dyslipidemia and cognitive decline, while CP‐depleted taxa are negatively associated with fatty liver. Subsequent serum metabolomics identified notably up‐regulated purine metabolism, and integrative analysis indicated an association between altered microbiota and elevated hypoxanthine. Phenotypic study and multi‐omics analysis in the Rax‐CreERT2::BrafV600E/+::PtenFlox/+ mouse model validated potential involvement of increased Clostridium and dysregulated purine metabolism in hypothalamic comorbidities. To further consolidate this, intervention experiments are performed and it is found that hypoxanthine co‐variated with the severity of hypothalamic comorbidities and abundance of Clostridium, and induced dysregulated purine metabolism along with redox imbalance in target organs (liver and brain cortex). Overall, the study demonstrated the potential of increased Clostridium and up‐regulated purine metabolism as signatures of CP‐associated hypothalamic‐comorbidities, and unveiled that elevated Clostridium, dysregulated purine metabolism, and redox imbalance may mediate the development and progression of CP‐associated hypothalamic‐comorbidities. [ABSTRACT FROM AUTHOR]

Background: Remote ischemic postconditioning (RIPostC) is an effective strategy for preventing key organs from becoming impaired due to an ischemia/reperfusion injury. In the current study, we investigated how remote exosome transfer of microRNAs (miRs) may contribute to the treatment effect of RIPostC on the central nerve system (CNS)., Methods: Human umbilical vein endothelial cells (HUVECs) were subjected to hypoxia/reoxygenation (H/R) and their miR expression profiles were investigated using the microarray method. The pathways associated with dysregulated miRs were analyzed by gene ontology (GO) annotation of the target genes and a Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. The role played by the most significantly down-regulated miR (miR-21-3p) in the protective effect of HUVEC-derived exosomes on H/R-treated neural cells was further investigated. The pathway mediating the effect of miR-21-3p was then explored by focusing on activity of autophagy-related 12 (ATG12) protein., Results: The miR expression profile of HUVECs significantly changed after H/R administration, with 104 miRs becoming upregulated and 249 miRs becoming downregulated. Based on the GO and KEGG analyses, the target genes of 8 selected miRs were involved in multiple biological pathways, including the hippo signaling pathway and longevity regulating pathway. Further studies showed that inhibition of miR-21-3p by HUVEC-derived exosomes or a specific inhibitor could the block apoptotic process in H/R-treated neural cells. Molecular level studies showed that the effect of miR-21-3p inhibition depended on the restored function of ATG12, which resulted in the activation of autophagy and suppression of apoptosis., Conclusion: Taken together, these results suggest that H/R caused significant changes of miR expression in exosomes derived from H/R-treated HUVECs, and the exosomes protect neurons against H/R-induced injuries by suppressing miR-21-3p., Competing Interests: None.