Nasal Mucosa

BackgroundParkinson's disease (PD) is a neurodegenerative disorder characterized by the degeneration of dopaminergic neurons in the substantia nigra (SN). Activation of the neuroinflammatory response has a pivotal role in PD. Mesenchymal stem cells (MSCs) have emerged as a promising therapeutic approach for various nerve injuries, but there are limited reports on their use in PD and the underlying mechanisms remain unclear.MethodsWe investigated the effects of clinical-grade hypoxia-preconditioned olfactory mucosa (hOM)-MSCs on neural functional recovery in both PD models and patients, as well as the preventive effects on mouse models of PD. To assess improvement in neuroinflammatory response and neural functional recovery induced by hOM-MSCs exposure, we employed single-cell RNA sequencing (scRNA-seq), assay for transposase accessible chromatin with high-throughput sequencing (ATAC-seq) combined with full-length transcriptome isoform-sequencing (ISO-seq), and functional assay. Furthermore, we present the findings from an initial cohort of patients enrolled in a phase I first-in-human clinical trial evaluating the safety and efficacy of intraspinal transplantation of hOM-MSC transplantation into severe PD patients.ResultsA functional assay identified that transforming growth factor-β1 (TGF-β1), secreted from hOM-MSCs, played a critical role in modulating mitochondrial function recovery in dopaminergic neurons. This effect was achieved through improving microglia immune regulation and autophagy homeostasis in the SN, which are closely associated with neuroinflammatory responses. Mechanistically, exposure to hOM-MSCs led to an improvement in neuroinflammation and neural function recovery partially mediated by TGF-β1 via activation of the anaplastic lymphoma kinase/phosphatidylinositol-3-kinase/protein kinase B (ALK/PI3K/Akt) signaling pathway in microglia located in the SN of PD patients. Furthermore, intraspinal transplantation of hOM-MSCs improved the recovery of neurologic function and regulated the neuroinflammatory response without any adverse reactions observed in patients with PD.ConclusionsThese findings provide compelling evidence for the involvement of TGF-β1 in mediating the beneficial effects of hOM-MSCs on neural functional recovery in PD. Treatment and prevention of hOM-MSCs could be a promising and effective neuroprotective strategy for PD. Additionally, TGF-β1 may be used alone or combined with hOM-MSCs therapy for treating PD.

The Drosophila melanogaster olfactory system is one of the most intensively studied parts of the nervous system in any animal. Composed of ~50 independent olfactory neuron classes, with several associated hygrosensory and thermosensory pathways, it has been subject to diverse types of experimental analyses. However, synthesizing the available information is limited by the incomplete data and inconsistent nomenclature found in the literature. In this work, we first "complete" the peripheral sensory map through the identification of a previously uncharacterized antennal sensory neuron population expressing Or46aB, and the definition of an exceptional "hybrid" olfactory neuron class comprising functional Or and Ir receptors. Second, we survey developmental, anatomical, connectomic, functional, and evolutionary studies to generate an integrated dataset and associated visualizations of these sensory neuron pathways, creating an unprecedented resource. Third, we illustrate the utility of the dataset to reveal relationships between different organizational properties of this sensory system, and the new questions these stimulate. Such examples emphasize the power of this resource to promote further understanding of the construction, function, and evolution of these neural circuits.

Chronic rhinosinusitis (CRS) is a common chronic inflammatory disease of the sinonasal cavity affecting millions worldwide. Its complex pathophysiology remains poorly understood, with emerging evidence implicating interactions between diverse immune and epithelial cells in disease progression. We applied single-cell RNA sequencing (scRNA-seq) and spatial transcriptomics to both dissociated and intact human tissues from individuals with CRS with and without nasal polyps and compared them with controls. We revealed mechanisms of macrophage-eosinophil recruitment, CD4+ and CD8+ T cell dysregulation, and mast cell enrichment. We identified key immune-epithelial interactions in tissue remodeling, particularly involving basal progenitor and tuft cells. A distinct basal cell trajectory was implicated in nasal polyp formation. Orthogonal validation with spatial transcriptomics from >100 individuals with CRS revealed conserved tissue remodeling features. Our study provides insights into CRS pathophysiology, highlighting immune-epithelial interactions as potential therapeutic targets in chronic inflammation, also serving as a resource for dissecting immune disease mechanisms.

Akkermansia muciniphila is recognized as a promising probiotic that improves the symptoms of a variety of diseases. However, the role and mechanism of A. muciniphila in regulating intestinal homeostasis remain to be explored. Here, we discovered that A. muciniphila was dramatically increased during colitis recovery, and its colonization greatly increased goblet cells to protect the intestinal barrier in mice. Amuc_0904, a previously uncharacterized A. muciniphila outer membrane protein, was identified to induce goblet cell differentiation. Mechanistically, Amuc_0904 directly interacted with MET and decreased its phosphorylation in epithelia, leading to decreased Wnt/β-catenin signaling and enhanced oxidative phosphorylation and mitochondrial function. Furthermore, Amuc_0904 and engineered probiotic Escherichia coli Nissle 1917 expressing Amuc_0904 were demonstrated to protect mice from colitis and colitis-associated colorectal cancer. The study reveals a previously unknown mechanism of A. muciniphila-mediated intestinal homeostasis recovery and provides a bioactive molecule with the potential to treat intestinal disorders.