Metformin to treat Huntington disease: A pleiotropic drug against a multi-system disorder

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• Huntington disease (HD) is a fatal neurodegenerative disorder caused by CAG repeat expansion in the HTT gene, leading to toxic mutant huntingtin (mHtt) protein aggregation.
• mHtt aggregates primarily in the frontal cortex and striatum, causing involuntary movements, cognitive decline, and psychiatric issues, but also affects other cell types.
• Metformin, a common anti-diabetic medication, has demonstrated neuroprotective effects in preclinical HD models.

Purpose of the Study:

• To review the therapeutic potential of metformin for treating Huntington disease.
• To explore the molecular mechanisms underlying metformin's neuroprotective effects in HD.
• To discuss the role of metformin in modulating cellular functions and the gut microbiome relevant to HD.

Main Methods:

• Literature review of studies investigating metformin's effects on HD models.
• Analysis of metformin's known targets, including AMPK and insulin signaling pathways.
• Examination of metformin's impact on cellular processes like autophagy and chaperone expression.
• Review of metformin's influence on gut microbiome composition and function.

Main Results:

• Metformin modulates key cellular pathways (e.g., AMPK, insulin signaling) that reduce mHtt toxicity.
• The drug promotes cellular protective mechanisms such as autophagy and chaperone expression.
• Metformin alters the gut microbiome, potentially influencing disease progression.
• These combined effects contribute to the observed neuroprotection in HD models.

Conclusions:

• Metformin exhibits significant therapeutic potential for Huntington disease through multifaceted mechanisms.
• Targeting pathways modulated by metformin, host-microbiome interactions, and pharmacogenomics could lead to personalized HD treatments.
• Further research into these areas may pave the way for novel therapeutic strategies for HD.