Integrated multi-omics analysis reveals gut microbiota dysbiosis and systemic disturbance in major depressive disorder.

Major depressive disorder (MDD) involves systemic changes in peripheral blood and gut microbiota, but the current understanding is incomplete. Herein, we conducted a multi-omics analysis of fecal and blood samples obtained from an observational cohort including MDD patients (n = 99) and healthy control (HC, n = 50). 16S rRNA sequencing of gut microbiota showed structural alterations in MDD, as characterized by increased Enterococcus. Metagenomics sequencing of gut microbiota showed substantial functional alterations including upregulation in the superpathway of the glyoxylate cycle and fatty acid degradation and downregulation in various metabolic pathways in MDD. Plasma metabolomics revealed decreased amino acids and bile acids, together with increased sphingolipids and cholesterol esters in MDD. Notably, metabolites involved in arginine and proline metabolism were decreased while sphingolipid metabolic pathway were increased. Mass cytometry analysis of blood immune cell subtypes showed rises in proinflammatory immune subsets and declines in anti-inflammatory immune subsets in MDD. Furthermore, our findings revealed disease severity-related factors of MDD. Interestingly, we classified MDD into two immune subtypes that were highly correlated with disease relapse. Moreover, we established discriminative signatures that differentiate MDD from HC. These findings contribute to a comprehensive understanding of the MDD pathogenesis and provide valuable resources for the discovery of biomarkers.

GV-971 attenuates the progression of neuromyelitis optica in murine models and reverses alterations in gut microbiota and associated peripheral abnormalities.

AIMS: Growing evidence suggests that an imbalanced gut microbiota composition plays a crucial role in the development of neuromyelitis optica spectrum disorders (NMOSD), an inflammatory demyelinating disease primarily affecting the optic nerves and central nervous system (CNS). In light of this, we explored the potential therapeutic benefits of GV-971 in NMOSD. GV-971 is a drug used for treating mild-to-moderate Alzheimer's disease, which targets the gut-brain axis and reduces neuroinflammation. METHODS: To evaluate GV-971's effects, we employed the experimental autoimmune encephalomyelitis (EAE) mouse model to establish NMOSD animal models. This was achieved by injecting NMO-IgG into aged mice (11 months old) or using NMO-IgG along with complement injection and microbubble-enhanced low-frequency ultrasound (MELFUS) techniques in young mice (7 weeks old). We assessed the impact of GV-971 on incidence rate, clinical scores, body weight, and survival, with methylprednisolone serving as a positive control. In NMOSD models of young mice, we analyzed spinal cord samples through H&E staining, immunohistochemistry, and Luxol Fast Blue staining. Fecal samples collected at different time points underwent 16S rRNA gene sequencing, while plasma samples were analyzed using cytokine array and untargeted metabolomics analysis. RESULTS: Our findings indicated that GV-971 significantly reduced the incidence of NMOSD, alleviated symptoms, and prolonged survival in NMOSD mouse models. The NMOSD model exhibited substantial neuroinflammation and injury, accompanied by imbalances in gut microbiota, peripheral inflammation, and metabolic disorders, suggesting a potentially vicious cycle that accelerates disease pathogenesis. Notably, GV-971 effectively reduces neuroinflammation and injury, and restores gut microbiota composition, as well as ameliorates peripheral inflammation and metabolic disorders. CONCLUSIONS: GV-971 attenuates the progression of NMOSD in murine models and reduces neuroinflammation and injury, likely through its effects on remodeling gut microbiota and peripheral inflammation and metabolic disorders.

Ultrasound deep brain stimulation decelerates telomere shortening in Alzheimer's disease and aging mice.

Telomere length is a reliable biomarker for health and longevity prediction in both humans and animals. The common neuromodulation techniques, including deep brain stimulation (DBS) and optogenetics, have excellent spatial resolution and depth penetration but require implementation of electrodes or optical fibers. Therefore, it is important to develop methods for noninvasive modulation of telomere length. Herein, we reported on a new method for decelerating telomere shortening using noninvasive ultrasound deep brain stimulation (UDBS). Firstly, we found that UDBS could activate the telomerase-associated proteins in normal mice. Then, in the Alzheimer's disease mice, UDBS was observed to decelerate telomere shortening of the cortex and myocardial tissue and to effectively improve spatial learning and memory abilities. Similarly, UDBS was found to significantly slow down telomere shortening of the cortex and peripheral blood, and improve motor and cognitive functions in aging mice. Finally, transcriptome analysis revealed that UDBS upregulated the neuroactive ligand-receptor interaction pathway. Overall, the present findings established the critical role of UDBS in delaying telomere shortening and indicated that ultrasound modulation of telomere length may constitute an effective therapeutic strategy for aging and aging-related diseases.