Readily releasable β cells with tight Ca2+-exocytosis coupling dictate biphasic glucose-stimulated insulin secretion

© 2024. The Author(s), under exclusive licence to Springer Nature Limited..

Biphasic glucose-stimulated insulin secretion (GSIS) is essential for blood glucose regulation, but a mechanistic model incorporating the recently identified islet β cell heterogeneity remains elusive. Here, we show that insulin secretion is spatially and dynamically heterogeneous across the islet. Using a zinc-based fluorophore with spinning-disc confocal microscopy, we reveal that approximately 40% of islet cells, which we call readily releasable β cells (RRβs), are responsible for 80% of insulin exocytosis events. Although glucose up to 18.2 mM fully mobilized RRβs to release insulin synchronously (first phase), even higher glucose concentrations enhanced the sustained secretion from these cells (second phase). Release-incompetent β cells show similarities to RRβs in glucose-evoked Ca2+ transients but exhibit Ca2+-exocytosis coupling deficiency. A decreased number of RRβs and their altered secretory ability are associated with impaired GSIS progression in ob/ob mice. Our data reveal functional heterogeneity at the level of exocytosis among β cells and identify RRβs as a subpopulation of β cells that make a disproportionally large contribution to biphasic GSIS from mouse islets.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:6

Enthalten in:

Nature metabolism - 6(2024), 2 vom: 27. Feb., Seite 238-253

Sprache:

Englisch

Beteiligte Personen:

Peng, Xiaohong [VerfasserIn]
Ren, Huixia [VerfasserIn]
Yang, Lu [VerfasserIn]
Tong, Shiyan [VerfasserIn]
Zhou, Renjie [VerfasserIn]
Long, Haochen [VerfasserIn]
Wu, Yunxiang [VerfasserIn]
Wang, Lifen [VerfasserIn]
Wu, Yi [VerfasserIn]
Zhang, Yongdeng [VerfasserIn]
Shen, Jiayu [VerfasserIn]
Zhang, Junwei [VerfasserIn]
Qiu, Guohua [VerfasserIn]
Wang, Jianyong [VerfasserIn]
Han, Chengsheng [VerfasserIn]
Zhang, Yulin [VerfasserIn]
Zhou, Mengxuan [VerfasserIn]
Zhao, Yiwen [VerfasserIn]
Xu, Tao [VerfasserIn]
Tang, Chao [VerfasserIn]
Chen, Zhixing [VerfasserIn]
Liu, Huisheng [VerfasserIn]
Chen, Liangyi [VerfasserIn]

Links:

Volltext

Themen:

Biphasic Insulins
Glucose
IY9XDZ35W2
Insulin
Journal Article

Anmerkungen:

Date Completed 28.02.2024

Date Revised 28.02.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1038/s42255-023-00962-0

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM367693577