The IGFBP3/TMEM219 pathway regulates beta cell homeostasis

Area of Science:

• Endocrinology
• Cell Biology
• Diabetes Research

Background:

• Pancreatic beta cell loss is a hallmark of type 1 (T1D) and type 2 diabetes (T2D).
• Effective therapeutic strategies to preserve beta cell mass are currently lacking.
• The insulin-like growth factor binding protein 3 (IGFBP3)/TMEM219 signaling axis's role in beta cell homeostasis is not fully understood.

Purpose of the Study:

• To investigate the role of the IGFBP3/TMEM219 pathway in pancreatic beta cell function and survival.
• To determine if targeting this pathway could be a therapeutic approach for T1D and T2D.

Main Methods:

• Analysis of TMEM219 expression on pancreatic beta cells.
• Assessment of IGFBP3 levels in patients and preclinical models of diabetes.
• In vitro and in vivo studies involving short-term and long-term inhibition of IGFBP3/TMEM219 signaling.
• Genetic ablation of TMEM219 in experimental models.
• Evaluation of beta cell function and diabetes onset.

Main Results:

• TMEM219 is expressed on pancreatic beta cells, and its ligand IGFBP3 promotes beta cell loss and dysfunction.
• Elevated IGFBP3 levels were observed in patients and models of T1D/T2D, indicating disrupted IGFBP3/TMEM219 signaling.
• Inhibition or genetic ablation of TMEM219 preserved beta cells, delayed diabetes onset, and promoted beta cell expansion with long-term blockade.
• Restoration of IGFBP3 levels correlated with improved beta cell function in patient cohorts.

Conclusions:

• The IGFBP3/TMEM219 pathway is a critical regulator of pancreatic beta cell homeostasis.
• Dysfunctional IGFBP3/TMEM219 signaling is implicated in the pathogenesis of T1D and T2D.
• Targeting the IGFBP3/TMEM219 pathway represents a promising therapeutic strategy for preserving and potentially expanding beta cell mass in diabetes.