On-target action of anti-tropomyosin drugs regulates glucose metabolism

Area of Science:

• Biochemistry
• Cell Biology
• Metabolic Research

Background:

• Tropomyosin 3.1 (Tpm3.1) is implicated in cellular functions, including actin dynamics.
• Understanding Tpm3.1's role in glucose metabolism is crucial for metabolic disease research.

Purpose of the Study:

• To investigate the effects of novel anti-Tpm (ATM) small molecule inhibitors on glucose metabolism in mice.
• To determine if ATM compounds target Tpm3.1 to regulate glucose homeostasis.

Main Methods:

• Administration of ATM compounds (TR100, ATM1001) to wild-type (WT) and Tpm3.1 knockout (KO) mice.
• Assessment of glucose clearance and glucose-stimulated insulin secretion (GSIS) in vivo.
• Examination of insulin-stimulated glucose uptake (ISGU) in skeletal muscle ex vivo and in MIN6 β-cells.

Main Results:

• ATM compounds decreased glucose clearance in WT mice, primarily by suppressing GSIS.
• The effect of ATM compounds on GSIS was reduced in Tpm3.1 KO mice, indicating on-target action.
• ATM drugs disrupted cortical actin cytoskeleton in MIN6 β-cells, affecting GSIS.
• Tpm3.1 plays a role in ISGU, with ATM compounds suppressing ISGU in WT but not KO muscle.

Conclusions:

• ATM drugs effectively inhibit Tpm3.1 function, impacting glucose metabolism.
• The primary mechanism involves Tpm3.1's role in regulating insulin secretion and glucose uptake.
• ATM compounds show specific, on-target effects on glucose metabolism with limited off-target consequences.