Single-cell analysis reveals transcriptional dynamics in primary parathyroid tissue

Studies on human parathyroid tissue are often limited to adenomatous tissue due to difficulty obtaining healthy tissue. We obtained nonhuman primate parathyroids to provide a suitable alternative for sequencing analysis that would bear the closest semblance to human organs as possible. We analyzed four M. mulatta normal parathyroid specimens to that show a continuous trajectory of cell states comprising the normal adult parathyroid. We calculated the predicted pseudotime progression based on transcriptomic signatures that were reflective of repopulating progenitors, progressing to chief cells, and ultimately oxyphils, and clustered genes based on their expression dynamics along this axis. As a comparator, we histologically characterized and sequenced four human adenomas with varying oxyphil and chief cell abundance to highlight similarities and differences to normal parathyroid cell expression dynamics. We noted abundant RARRES2 transcripts that were detected in both human adenoma and normal primate parathyroid cells, and provided co-immunostaining validation of Chemerin presence in PTH-expressing cells, which could play a previously unrecognized role in parathyroid endocrine function.