bioRxiv Science⌕ Search

bioRxiv · 10.64898/2026.02.13.704343

Tirzepatide improves pancreatic β-cell function in mice and patients with type 2 diabetes.

Abstract

The dual incretin receptor agonist tirzepatide improves {beta}-cell function in T2D patients, but the underlying mechanism remains unclear. This study aimed to elucidate the molecular pathway through which tirzepatide restores {beta}-cell functional improvement. High-fat diet (HFD)-fed C57BL/6J mice were treated with vehicle, a GIP analogue, semaglutide or tirzepatide. Tirzepatide significantly reduced body weight and improved glucose tolerance in HFD-fed mice without altering {beta}-cell mass, proliferation, or apoptosis. Instead, tirzepatide reversed {beta}-cell dedifferentiation, as indicated by reduced ALDH1A3 expression and restored levels of the identity transcription factors PDX1 and MAFA. Single-cell RNA sequencing (scRNA seq) and in vitro studies revealed that tirzepatide up-regulated FOXO1, reactivating the FOXO1-PDX1/MAFA axis. In T2D patients, tirzepatide improved glycemic control, reduced insulin demand, increased HOMA-{beta}, and decreased HOMA-IR. Improvement in HOMA-{beta} correlated positively with baseline insulin resistance. Hence, our study suggested that tirzepatide restores {beta}-cell function in T2D by reprogramming stressed {beta} cells and re-establishing {beta}-cell identity through FOXO1-dependent transcriptional reactivation. These findings provide a mechanistic basis for the superior efficacy of dual incretin receptor agonism in T2D management. ARTICLE HIGHLIGHTSO_LITirzepatide restores {beta} cell identity and function without altering {beta} cell mass in HFD induced diabetic mice. C_LIO_LITirzepatide reverses {beta}-cell dedifferentiation and restores key {beta}-cell transcription factors (PDX1, MAFA) through reactivation of the AKT-FOXO1 signaling pathway. C_LIO_LITirzepatide increases HOMA-{beta} and decreases HOMA-IR in T2D patients, and improvements in HOMA-{beta} positively correlate with baseline insulin resistance. C_LIO_LIThese results demonstrate that tirzepatides therapeutic benefits are not only metabolic but also involve direct restoration of {beta}-cell identity and function. This highlights {beta}-cell reprogramming as a novel therapeutic avenue, thus supporting the broader clinical adoption of dual incretin receptor agonists. C_LI

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Li, Z., Guo, J., Cheng, Y., Zhang, T., Luo, X., Zhang, S., Ren, Q., Wu, Z., Chen, N., Li, M.. 2026-02-16. Tirzepatide improves pancreatic β-cell function in mice and patients with type 2 diabetes.. https://doi.org/10.64898/2026.02.13.704343

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related preprints

Hypothalamic Farnesoid X Receptor deficiency alters energy balance by modulating hepatic glucose production and adipose tissue metabolism through central insulin signaling.

Objectives: The bile acid nuclear receptor Farnesoid X Receptor (FXR, NR1H4) is a major regulator of metabolism and energy homeostasis in peripheral organs. It modulates bile acid, glucose, and lipid metabolism, as well as fat mass and body weight. However, FXR is also expressed in the brain, particularly in the hypothalamus, a key center for the regulation of energy homeostasis. Although one study has demonstrated a role for brain FXR activation in energy balance, its specific hypothalamic role is still unknown. Here, we examined the role of FXR in the mediobasal hypothalamus in the regulation of energy balance. Methods: We used a genetic approach combined with metabolic phenotyping to determine the effect of FXR invalidation in the mediobasal hypothalamus on metabolic parameters involved in the central regulation of energy homeostasis. Results: Our results demonstrate that hypothalamic FXR deficiency induces a positive energy balance, resulting in a reduction in energy expenditure due to alterations in glucose metabolism accompanied by structural changes in white adipose tissues. Conclusion: This study uncovers a previously unrecognized role for hypothalamic FXR in the central homeostatic control of energy balance, providing new insights into its contribution to peripheral glucose metabolism and adipose tissue structural remodeling.

physiology↗

Rad and Phospholamban are Key Drivers of the Ventricular Adrenergic Response and Stress-Induced Arrhythmia

The adrenergic response is a fundamental mechanism that regulates heart rate (chronotropy), cardiac contractility (inotropy) and relaxation (lusitropy). Adrenergic stress is also a recognized trigger of arrhythmia in disease. Yet, our understanding of the underlying molecular basis remains incomplete. Protein kinase A (PKA) and the calcium/calmodulin-dependent kinase II (CaMKII) phosphorylate multiple targets proposed to participate in the adrenergic response, including the GTP-binding protein Rad, phospholamban (PLB) and ryanodine receptor 2 (RyR2). Here we demonstrate that phosphorylation of both Rad and PLB is necessary for inotropy and lusitropy. We show that changes in cardiac contractility and relaxation are primarily dependent on intracellular calcium handling. Finally, we report that Rad and PLB control stress-induced arrhythmogenesis, despite the phosphorylation of other pro-arrhythmic targets. We have identified the essential molecular components of the adrenergic response, resolving a long-standing debate in cardiac excitation-contraction coupling and refining current models of sympathetic regulation in health and disease.

physiology↗

Light-cycle time-restricted feeding remodels a hidden layer of the cardiac transcriptome through sex-specific transcript switching

Light-cycle time-restricted feeding disrupts daily cardiovascular and thermoregulatory rhythms, but the molecular effects of light-cycle time-restricted feeding on the heart have been measured only at the level of total gene expression. We used Oxford Nanopore long-read RNA sequencing to resolve the full-length ventricular transcriptome from male and female mice under ad libitum feeding or light-cycle time-restricted feeding across the 24-hour cycle. Greater than 20% of cardiac transcripts represent unannotated variants of known genes absent from the current GENCODE reference annotation. Light-cycle time-restricted feeding reorganizes transcript usage across hundreds of genes, including genes encoding splicing regulators, largely without changing total gene expression. The genes affected are sex-specific, with fewer than 2% of changes shared at the gene, transcript, and transcript-usage levels. We show that transcript-level regulation is a previously underrecognized component of the cardiac response to altered feeding behavior, undetected by conventional short-read approaches.

physiology↗