Dataset Information

Single Cell Peptide Heterogeneity of Rat Islets of Langerhans.

ABSTRACT: Measuring the chemical composition of individual cells in mammalian organs can provide critical insights toward understanding the mechanisms leading to their normal and pathological function. In this work, single cell heterogeneity of islets of Langerhans is characterized with high throughput by microscopy-guided single cell matrix-assisted laser desorption/ionization mass spectrometry. Two levels of chemical heterogeneity were observed from the analysis of more than 3000 individual cells. Within a single islet, cellular heterogeneity was evident from the exclusive expression of the canonical biomarkers glucagon, insulin, pancreatic polypeptide (PP), and somatostatin within ?-, ?-, ?-, and ?-cells, respectively. We localized the neuropeptide WE-14, a known cell-to-cell signaling molecule, to individual ?-cells. Moreover, several unreported endogenous peptides generated by dibasic site cleavages of PP were detected within individual ?-cells. Of these, PP(27-36) was previously shown to activate the human Y4 receptor, suggesting it has a signaling role in vivo. Heterogeneity in cell composition was also observed between islets as evidenced by a 50-fold larger ?-cell population in islets of the dorsal pancreas compared to the ventral-derived pancreatic islets. Finally, PP(27-36) was more abundant in ?-cells from the ventral region of the pancreas, indicating differences in the extent of PP-prohormone processing in the two regions of the pancreas.

SUBMITTER: Jansson ET

PROVIDER: S-EPMC5104495 | biostudies-literature | 2016 Sep

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Single Cell Peptide Heterogeneity of Rat Islets of Langerhans.

Jansson Erik T ET Comi Troy J TJ Rubakhin Stanislav S SS Sweedler Jonathan V JV

ACS chemical biology 20160729 9

Measuring the chemical composition of individual cells in mammalian organs can provide critical insights toward understanding the mechanisms leading to their normal and pathological function. In this work, single cell heterogeneity of islets of Langerhans is characterized with high throughput by microscopy-guided single cell matrix-assisted laser desorption/ionization mass spectrometry. Two levels of chemical heterogeneity were observed from the analysis of more than 3000 individual cells. Withi ...[more]

PMID: 27414158

Similar Datasets

Project description:1. Protein kinase activities in homogenates of rat islets of Langerhans were studied. 2. On incubation of homogenates with [gamma-32P]ATP, incorporation of 32P into protein occurred: this phosphorylation was neither increased by cyclic AMP nor decreased by the cyclic AMP-dependent protein kinase inhibitor described by Ashby & Walsh [(1972) J. Biol. Chem. 247, 6637--6642]. 3. On incubation of homogenates with [gamma-32P]ATP and histone as exogenous substrate for phosphorylation, incorporation of 32P into protein was stimulated by cyclic AMP (approx. 2.5-fold) and was inhibited by the cyclic AMP-dependent protein kinase inhibitor. In contrast, when casein was used as exogenous substrate, incorporation of 32P into protein was not stimulated by cyclic AMP, nor was it inhibited by the cyclic AMP-dependent protein kinase inhibitor. 4. DEAE-cellulose ion-exchange chromatography resolved four peaks of protein kinase activity. One species was the free catalytic subunit of cyclic AMP-dependent protein kinase, two species corresponded to 'Type I' and 'Type II' cyclic AMP-dependent protein kinase holoenzymes [see Corbin, Keely & Park (1975) J. Biol. Chem. 250, 218--225], and the fourth species was a cyclic AMP-independent protein kinase. 5. Determination of physical and kinetic properties of the protein kinases showed that the properties of the cyclic AMP-dependent activities were similar to those described in other tissues and were clearly distinct from those of the cyclic AMP-independent protein kinase. 6. The cyclic AMP-independent protein kinase had an s20.w of 5.2S, phosphorylated a serine residue(s) in casein and was not inhibited by the cyclic AMP-dependent protein kinase inhibitor. 7. These studies demonstrate the existence in rat islets of Langerhans of multiple forms of cyclic AMP-dependent protein kinase and also the presence of a cyclic AMP-independent protein kinase distinct from the free catalytic subunit of cyclic AMP-dependent protein kinase. The presence of the cyclic AMP-independent protein kinase may account for the observed characteristics of 32P incorporation into endogenous protein in homogenates of rat islets.

Dataset Information

Single Cell Peptide Heterogeneity of Rat Islets of Langerhans.

Publications

Single Cell Peptide Heterogeneity of Rat Islets of Langerhans.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets