Search bioRxiv⌕ Search
Home/Archive/bioRxiv

bioRxiv · 10.1101/2023.09.08.556709

Calcium-dependent transcriptional profiles of human pancreatic islet cells reveal functional diversity in islet subpopulations

Yoon, J. S.·Sasaki, S.·Velghe, J.·Zosel, K.·Lee, M. Y. Y.·Winata, H.·Nian, C.·Lynn, F. C.
View original source ↗Export metadata ↓

Abstract

Aims/hypothesisPancreatic islets depend on cytosolic calcium to trigger the secretion of glucoregulatory hormones and regulate the transcription of genes important for the response to stimuli. To date, there has not been an attempt to profile calcium-regulated gene expression in all islet cell types. Our aim was to construct a large single-cell transcriptomic dataset from human islets exposed to conditions that would acutely induce or inhibit intracellular calcium signalling, while preserving biological heterogeneity. MethodsWe exposed intact human islets from three donors to the following conditions: (1) 2.8 mM glucose; (2) 25 mM glucose and 40 mM KCl to maximally stimulate calcium signalling; and (3) 25 mM glucose, 40 mM KCl and 5 mM EGTA (calcium chelator) to inhibit calcium signalling, for 1 hour. We sequenced 43,909 cells from all islet cell types, and further subsetted the cells to form an endocrine cell-specific dataset of 32,486 cells expressing INS, GCG, SST or PPY. We compared transcriptomes across conditions to determine the differentially expressed calcium-regulated genes in each endocrine cell type, and in each endocrine cell subcluster of alpha and beta cells. ResultsBased on the number of calcium-regulated genes, we found that each alpha and beta cell cluster had a different magnitude of calcium response. We also showed that a polyhormonal cluster expressing INS, GCG, and SST is defined by calcium-regulated genes specific to this cluster. Finally, we identified the gene PCDH7 from the beta cell clusters that had the highest number of calcium-regulated genes, and showed that cells expressing cell surface PCDH7 protein have enhanced glucose-stimulated insulin secretory function. ConclusionsHere we use our single-cell dataset to show that human islets have cell-type-specific calcium-regulated gene expression profiles, some of them specific to subpopulations. In our dataset, we identify PCDH7 as a novel marker of beta cells having an increased number of calcium-regulated genes and enhanced insulin secretory function. Data availabilityA searchable and user-friendly format of the data in this study, specifically designed for rapid mining of single-cell RNA sequencing data, is available at https://lynnlab.shinyapps.io/Hislet_2023/. The raw data files are available at NCBI Gene Expression Omnibus (GSE196715).

Explore related subjects

physiologyPreprint

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yoon, J. S., Sasaki, S., Velghe, J., Zosel, K., Lee, M. Y. Y., Winata, H., Nian, C., Lynn, F. C.. 2023-09-12. Calcium-dependent transcriptional profiles of human pancreatic islet cells reveal functional diversity in islet subpopulations. https://doi.org/10.1101/2023.09.08.556709

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

bioRxiv2026

Thoracoabdominal pressure transmission during prone and supine cardiopulmonary resuscitation in fresh-frozen human cadavers

Background: Prone cardiopulmonary resuscitation (CPR) may be necessary when turning a prone patient supine would delay chest compressions. Although prone compressions can generate arterial pressures comparable with or greater than supine CPR, the pathway of pressure transmission is uncertain. We examined synchronized intrathoracic, intra-abdominal, and central arterial pressures in both supine and prone positions. Methods: Two thawed fresh-frozen adult cadavers underwent three, 2-minute mechanical CPR trials per position in a counterbalanced crossover sequence. Solid-state catheters recorded pleural, peritoneal, and central arterial pressures simultaneously. Trial-level outcomes included peak pressure, mean pressure, pressure-time area, and the mean peritoneal-to-pleural pressure gradient. Exploratory fixed-effects models included position, cadaver, and their interaction. Results: Prone CPR increased peak intrathoracic pressure by 7.04 mmHg, peak intra-abdominal pressure by 21.69 mmHg, and peak arterial pressure by 15.40 mmHg. Mean intra-abdominal and arterial pressures increased by 16.22 and 9.90 mmHg, respectively. The mean peritoneal-to-pleural gradient reversed direction from -8.46 mmHg supine to 4.85 mmHg prone. Intrathoracic pressure-time area increased 3.4-fold, from 1.62 to 5.46 mmHg{middle dot}s, and arterial pressure-time area increased 2.2-fold, from 2.96 to 6.42 mmHg{middle dot}s. Conclusions: Compared to supine, prone mechanical CPR generated higher arterial pressures and reversed the pressure relationship across the thoracoabdominal boundary in both cadavers. Higher abdominal pressure coincided with a larger intrathoracic pressure-time area, a pattern compatible with reduced caudal pressure dissipation.

physiology↗
bioRxiv2026

Genetic Variation, Iron Status, and FGF23 Signaling Converge to Regulate Renal Calcium Buffering in Sickle Cell Disease

Sickle cell disease (SCD) causes heterogeneous mineral imbalances including variable degrees of hypocalcemia. The kidney controls systemic calcium by reabsorbing calcium from the glomerular filtrate via paracellular transport and transcellular transport in the nephron tubules, yet it is unknown whether these processes are modulated by genetic or environmental factors or disrupted in SCD. Using SCD mouse models and single-cell multiomics, we identify the distal convoluted tubule (DCT) as the nephron segment most susceptible to calcium reabsorption dysfunction in SCD, mainly via reduction of calcium buffer protein calbindin 1 (CALB1). We show that CALB1 and its encoding mRNA are decreased in DCT cells in SCD, alongside decreased Klotho (KL)-dependent fibroblast growth factor (FGF) 23 signaling and intracellular calcium signaling. Dietary iron restriction reduces CALB1, KL, and calcium exporter SLC8A1 levels in SCD kidneys. Loss of CALB1 shifts DCT cells toward energy-inefficient glycolysis with the metabolite 2,3-diphosphoglycerate impairing KL-dependent FGF23 signaling to create a feed-forward loop suppressing calcium reabsorption. Analysis of gene expression and protein quantitative trait loci data from kidneys of genetically diverse mice revealed that Calb1 expression levels are highly heritable and co-regulated with Slc8a1, identifying a genetic axis that dictates differential capacities for calcium buffering and trafficking toward blood in the kidney. Together, these findings support a model in which genetic variation, dietary iron status, and FGF23 signaling converge on DCT calcium buffering to reduce renal calcium reabsorption in the SCD kidney. This points to personalized, genotype- and iron-dependent strategies for managing mineral metabolism in SCD patients.

physiology↗
bioRxiv2026

Silver spoon effect: early-life environment and adult survival in a primate.

Early environmental conditions can have long-lasting effects on survival and reproductive fitness. Using a 23 year-long monitoring data set of captive mouse lemur's life history traits, we tested a relationship between maternal allocation to offspring (N = 1365) and their adulthood survival. Maternal characteristics such as age or body condition did not affect allocation to offspring whatever the litter size (1 to 3). Although birth mass depended on size and composition of the litters, mouse lemur survival was highly correlated with body mass acquired after weaning in both sexes, through potential sibling competition. Moreover, female's reproductive success correlated with this body mass and was consistently associated with increased longevity. These findings suggest the presence of a silver spoon effect under constant captive conditions. However, cumulative effects of genetic and adulthood social conditions strongly interact to affect adult survival. Deaths related to intra- or inter-sexes aggressive social interactions may outweigh effect of early environment and therefore minimize the silver-spoon effect on captive mouse lemur's survival. However, having a high body mass after weaning appeared to be a determinant factor in individual survival for mouse lemurs.

physiology↗