Aarthi Venkat1,10, Maximillian J. Carlino2,3,10, Betty R. Lawton2,3,10, Manju L. Prasad4, Matthew Amodio5,6, Courtney E. Gibson7, Caroline J. Zeiss8, Scott E. Youlten9, Smita Krishnaswamy1,2,5,9,11 and Diane S. Krause2,3,4,11 1Computational Biology and Bioinformatics Program, Yale University, New Haven, Connecticut 06511, USA; 2Yale Stem Cell Center, Yale School of Medicine, New Haven, Connecticut 06520, USA; 3Department of Laboratory Medicine, Yale School of Medicine, New Haven, Connecticut 06510, USA; 4Department of Pathology, Yale School of Medicine, New Haven, Connecticut 06520-8023, USA; 5Department of Computer Science, Yale University, New Haven, Connecticut 06511, USA; 6Broad Institute of MIT and Harvard, Cambridge, Massachusetts 02142, USA; 7Department of Surgery, Yale School of Medicine, New Haven, Connecticut 06520, USA; 8Department of Comparative Medicine, Yale School of Medicine, New Haven, Connecticut 06520, USA; 9Department of Genetics, Yale School of Medicine, New Haven, Connecticut 06510, USA

↵10 These authors contributed equally to this work.

↵11 These authors contributed equally to this work.

Corresponding authors: diane.krauseyale.edu, smita.krishnaswamyyale.edu Abstract

Studies on human parathyroids are generally limited to hyperfunctioning glands owing to the difficulty in obtaining normal human tissue. We therefore obtained non-human primate (NHP) parathyroids to provide a suitable alternative for sequencing that would bear a close semblance to human organs. Single-cell RNA expression analysis of parathyroids from four healthy adult M. mulatta reveals a continuous trajectory of epithelial cell states. Pseudotime analysis based on transcriptomic signatures suggests a progression from GCM2hi progenitors to mature parathyroid hormone (PTH)–expressing epithelial cells with increasing core mitochondrial transcript abundance along pseudotime. We sequenced, as a comparator, four histologically characterized hyperfunctioning human parathyroids with varying oxyphil and chief cell abundance and leveraged advanced computational techniques to highlight similarities and differences from non-human primate parathyroid expression dynamics. Predicted cell–cell communication analysis reveals abundant endothelial cell interactions in the parathyroid cell microenvironment in both human and NHP parathyroid glands. We show abundant RARRES2 transcripts in both human adenoma and normal primate parathyroid cells and use coimmunostaining to reveal high levels of RARRES2 protein (also known as chemerin) in PTH-expressing cells, which could indicate that RARRES2 plays an unrecognized role in parathyroid endocrine function. The data obtained are the first single-cell RNA transcriptome to characterize nondiseased parathyroid cell signatures and to show a transcriptomic progression of cell states within normal parathyroid glands, which can be used to better understand parathyroid cell biology.

Received July 1, 2023. Accepted June 3, 2024.