Melatonin/Nrf2/NLRP3 Connection in Mouse Heart Mitochondria during Aging

Area of Science:

• Cardiovascular Biology
• Aging Research
• Mitochondrial Medicine

Background:

• Aging is a primary risk factor for cardiovascular diseases (CVD).
• Age-related cardiac dysfunction involves oxidative stress, mitochondrial dysfunction, and innate immune pathway activation, including NF-κB/NLRP3.
• Molecular mechanisms linking cardiac aging and these pathways require further elucidation.

Purpose of the Study:

• To investigate the role of the NLRP3 inflammasome in cardiac aging.
• To determine if melatonin can counteract NLRP3-mediated effects in the aging myocardium.
• To analyze the impact of NLRP3 inflammasome and melatonin on mitochondrial dynamics, autophagy, apoptosis, and antioxidant responses in aged hearts.

Main Methods:

• Analysis of protein expression related to mitochondrial dynamics, autophagy, apoptosis, and Nrf2 antioxidant response.
• Assessment of mitochondrial ultrastructure in wild-type and NLRP3-knockout mice at different ages (3, 12, 24 months).
• Evaluation of melatonin treatment effects on these parameters in aged mice.

Main Results:

• NLRP3 deficiency prevented age-related mitochondrial dynamic alterations and reduced mitochondrial damage in cardiac muscle.
• NLRP3 absence minimally affected cardiac autophagy but influenced the Bax/Bcl2 ratio, not p53 or caspase 9.
• Melatonin treatment restored age-related mitochondrial dynamics, exhibited anti-apoptotic effects, and improved mitochondrial ultrastructure.

Conclusions:

• The NLRP3 inflammasome plays a significant role in cardiac aging, particularly in mitochondrial dysfunction.
• Melatonin effectively counteracts age-related cardiac mitochondrial damage and apoptosis, suggesting therapeutic potential.
• Targeting the NLRP3 inflammasome and utilizing melatonin may offer strategies to mitigate age-related cardiovascular decline.