Insufficient TRPM5 Mediates Lipotoxicity-induced Pancreatic β-cell Dysfunction

© 2024. Huazhong University of Science and Technology..

OBJECTIVE: While the reduction of transient receptor potential channel subfamily M member 5 (TRPM5) has been reported in islet cells from type 2 diabetic (T2D) mouse models, its role in lipotoxicity-induced pancreatic β-cell dysfunction remains unclear. This study aims to study its role.

METHODS: Pancreas slices were prepared from mice subjected to a high-fat-diet (HFD) at different time points, and TRPM5 expression in the pancreatic β cells was examined using immunofluorescence staining. Glucose-stimulated insulin secretion (GSIS) defects caused by lipotoxicity were mimicked by saturated fatty acid palmitate (Palm). Primary mouse islets and mouse insulinoma MIN6 cells were treated with Palm, and the TRPM5 expression was detected using qRT-PCR and Western blotting. Palm-induced GSIS defects were measured following siRNA-based Trpm5 knockdown. The detrimental effects of Palm on primary mouse islets were also assessed after overexpressing Trpm5 via an adenovirus-derived Trpm5 (Ad-Trpm5).

RESULTS: HFD feeding decreased the mRNA levels and protein expression of TRPM5 in mouse pancreatic islets. Palm reduced TRPM5 protein expression in a time- and dose-dependent manner in MIN6 cells. Palm also inhibited TRPM5 expression in primary mouse islets. Knockdown of Trpm5 inhibited insulin secretion upon high glucose stimulation but had little effect on insulin biosynthesis. Overexpression of Trpm5 reversed Palm-induced GSIS defects and the production of functional maturation molecules unique to β cells.

CONCLUSION: Our findings suggest that lipotoxicity inhibits TRPM5 expression in pancreatic β cells both in vivo and in vitro and, in turn, drives β-cell dysfunction.

Medienart:

E-Artikel

Erscheinungsjahr:

2024

Erschienen:

2024

Enthalten in:

Zur Gesamtaufnahme - volume:44

Enthalten in:

Current medical science - 44(2024), 2 vom: 22. Apr., Seite 346-354

Sprache:

Englisch

Beteiligte Personen:

Wang, Kai-Yuan [VerfasserIn]
Wu, Shi-Mei [VerfasserIn]
Yao, Zheng-Jian [VerfasserIn]
Zhu, Yun-Xia [VerfasserIn]
Han, Xiao [VerfasserIn]

Links:

Volltext

Themen:

β-cell dysfunction
Glucose
IY9XDZ35W2
Insulin
Journal Article
Lipotoxicity
TRPM5
Type 2 diabetes

Anmerkungen:

Date Completed 22.04.2024

Date Revised 22.04.2024

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1007/s11596-023-2795-5

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM37007243X