AgRP neurons shape the sperm small RNA payload

Area of Science:

• Epigenetics
• Reproductive Biology
• Metabolic Health

Background:

• Paternal diet and obesity can influence offspring health through epigenetic mechanisms.
• Sperm RNA, including small noncoding RNAs, is a potential mediator of these effects.
• The role of specific neuronal pathways in mediating these paternal influences is not fully understood.

Purpose of the Study:

• To investigate how activating hypothalamic Agouti-related peptide (AgRP) neurons, simulating obesity, affects the small noncoding RNA content of sperm.
• To determine if these changes in sperm RNA are similar to those induced by dietary factors.
• To explore the role of AgRP neurons in metabolic epigenetic inheritance.

Main Methods:

• Utilized a mouse model to activate hypothalamic AgRP neurons, mimicking obesity-associated metabolic changes.
• Analyzed the small noncoding RNA profile of sperm from treated and control mice.
• Compared observed RNA alterations with those previously reported following high-fat diet interventions.

Main Results:

• Activation of AgRP neurons led to significant changes in the sperm's small noncoding RNA payload.
• Alterations were particularly pronounced in transfer RNA-derived small RNAs (tsRNAs).
• The observed tsRNA changes mirrored those induced by short-term high-fat diets in previous studies.

Conclusions:

• Hypothalamic AgRP neurons play a role in modifying sperm RNA content in response to metabolic challenges.
• AgRP neuron-mediated changes in sperm tsRNAs suggest a common regulatory pathway linking paternal metabolic state to offspring epigenetics.
• These findings highlight a potential mechanism for metabolic epigenetic inheritance influenced by paternal obesity and diet.