Histone deacetylase 6 (HDAC6) is an essential factor for oocyte maturation and asymmetric division in mice

Area of Science:

• Reproductive Biology
• Cell Biology
• Epigenetics

Background:

• Tubastatin A (Tub-A) is a selective histone deacetylase 6 (HDAC6) inhibitor used in cancer and asthma treatments.
• The impact of Tub-A on oocyte maturation and asymmetric division remains largely unknown.
• Understanding Tub-A's effects is crucial for reproductive toxicology and fertility research.

Purpose of the Study:

• To investigate the effects of Tub-A on meiotic maturation in mouse oocytes.
• To elucidate the potential regulatory role of Tub-A in oocyte development.
• To determine the molecular mechanisms underlying Tub-A's impact on oocyte division.

Main Methods:

• Treatment of mouse oocytes with varying concentrations of Tubastatin A.
• Microscopic analysis of spindle structure, chromosome alignment, and actin cap formation.
• Assessment of protein expression levels for key regulators like mTOR and mDia1.
• Evaluation of first polar body extrusion as an indicator of successful maturation.

Main Results:

• Tub-A treatment increased α-tubulin acetylation and impaired spindle migration and actin cap formation.
• Oocytes treated with Tub-A showed dose-dependent arrest at MI-like or GVBD-like stages with decondensed chromosomes.
• Tub-A reduced mTOR and mDia1 protein expression in an HDAC6-dependent manner.
• A significant failure in first polar body extrusion was observed in Tub-A treated oocytes.

Conclusions:

• Histone deacetylase 6 (HDAC6) is essential for proper oocyte maturation and asymmetric division in mice.
• Tub-A disrupts oocyte maturation by interfering with the HDAC6/mTOR and HDAC6/mDia1 pathways.
• These findings reveal a novel role for HDAC6 in regulating key events of female meiosis.