Increased glycolysis affects β-cell function and identity in aging and diabetes

Naoya Murao, Norihide Yokoi, Harumi Takahashi, Tomohide Hayami, Yasuhiro Minami, Susumu Seino

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)

Abstract

Objective: Age is a risk factor for type 2 diabetes (T2D). We aimed to elucidate whether β-cell glucose metabolism is altered with aging and contributes to T2D. Methods: We used senescence-accelerated mice (SAM), C57BL/6J (B6) mice, and ob/ob mice as aging models. As a diabetes model, we used db/db mice. The glucose responsiveness of insulin secretion and the [U-13C]-glucose metabolic flux were examined in isolated islets. We analyzed the expression of β-cell-specific genes in isolated islets and pancreatic sections as molecular signatures of β-cell identity. β cells defective in the malate-aspartate (MA) shuttle were previously generated from MIN6-K8 cells by the knockout of Got1, a component of the shuttle. We analyzed Got1 KO β cells as a model of increased glycolysis. Results: We identified hyperresponsiveness to glucose and compromised cellular identity as dysfunctional phenotypes shared in common between aged and diabetic mouse β cells. We also observed a metabolic commonality between aged and diabetic β cells: hyperactive glycolysis through the increased expression of nicotinamide mononucleotide adenylyl transferase 2 (Nmnat2), a cytosolic nicotinamide adenine dinucleotide (NAD)-synthesizing enzyme. Got1 KO β cells showed increased glycolysis, β-cell dysfunction, and impaired cellular identity, phenocopying aging and diabetes. Using Got1 KO β cells, we show that attenuation of glycolysis or Nmnat2 activity can restore β-cell function and identity. Conclusions: Our study demonstrates that hyperactive glycolysis is a metabolic signature of aged and diabetic β cells, which may underlie age-related β-cell dysfunction and loss of cellular identity. We suggest Nmnat2 suppression as an approach to counteract age-related T2D.

Original languageEnglish
Article number101414
JournalMolecular Metabolism
Volume55
DOIs
Publication statusPublished - 01-2022

All Science Journal Classification (ASJC) codes

  • Molecular Biology
  • Cell Biology

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