Aging-related olfactory loss is associated with olfactory stem cell transcriptional alterations in humans
Allison D. Oliva, … , Hiroaki Matsunami, Bradley J. Goldstein
Allison D. Oliva, … , Hiroaki Matsunami, Bradley J. Goldstein
Published January 6, 2022
Citation Information: J Clin Invest. 2022;132(4):e155506. https://doi.org/10.1172/JCI155506.
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Clinical Medicine Aging Neuroscience

Aging-related olfactory loss is associated with olfactory stem cell transcriptional alterations in humans

Abstract

BACKGROUND Presbyosmia, or aging-related olfactory loss, occurs in a majority of humans over age 65 years, yet remains poorly understood, with no specific treatment options. The olfactory epithelium (OE) is the peripheral organ for olfaction and is subject to acquired damage, suggesting a likely site of pathology in aging. Adult stem cells reconstitute the neuroepithelium in response to cell loss under normal conditions. In aged OE, patches of respiratory-like metaplasia have been observed histologically, consistent with a failure in normal neuroepithelial homeostasis.Methods Accordingly, we have focused on identifying cellular and molecular changes in presbyosmic OE. The study combined psychophysical testing with olfactory mucosa biopsy analysis, single-cell RNA-Sequencing (scRNA-Seq), and culture studies.Results We identified evidence for inflammation-associated changes in the OE stem cells of presbyosmic patients. The presbyosmic basal stem cells exhibited increased expression of genes involved in response to cytokines or stress or the regulation of proliferation and differentiation. Using a culture model, we found that cytokine exposure drove increased TP63, a transcription factor acting to prevent OE stem cell differentiation.Conclusions Our data suggest aging-related inflammatory changes in OE stem cells may contribute to presbyosmia via the disruption of normal epithelial homeostasis. OE stem cells may represent a therapeutic target for restoration of olfaction.Funding NIH grants DC018371, NS121067, DC016224; Office of Physician-Scientist Development, Burroughs-Wellcome Fund Research Fellowship for Medical Students Award, Duke University School of Medicine.

Authors

Allison D. Oliva, Rupali Gupta, Khalil Issa, Ralph Abi Hachem, David W. Jang, Sebastian A. Wellford, E. Ashley Moseman, Hiroaki Matsunami, Bradley J. Goldstein

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Figure 1

Integrated analysis of 36,091 cells from human olfactory epithelial biopsies of normosmic and presbyosmic adults.

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Integrated analysis of 36,091 cells from human olfactory epithelial biop...
(A) Schematic illustration of cell types in human olfactory and respiratory nasal epithelium. (B) Human OE from an 80-year-old presbyosmic subject; brackets and asterisks indicate areas containing TUJ1+ OE neurons (green); a patch of aneuronal respiratory-like metaplasia is marked by the white arrow; HBCs are labeled with anti-KRT5 (magenta). Nuclei are stained with DAPI (blue). Scale bar: 50 μM. (C) UMAP projection showing integrated data set split into separate plots by sample. (D) UMAP projection of combined data set; clusters are annotated according to canonical markers. (E) Contributions from normosmic or presbyosmic cohorts are quantified for indicated cell categories. Data are represented as mean ± SEM. n = 3 samples per cohort.