L-arginine attenuates Streptococcus uberis-induced inflammation by decreasing miR155 level

Area of Science:

• Immunology
• Microbiology
• Molecular Biology

Background:

• L-arginine is crucial for innate immunity.
• MicroRNA 155 (miR155) regulates immune cell homeostasis.
• The interaction between L-arginine and miR155 in bacterial infections remains unclear.

Purpose of the Study:

• Investigate miR155's role in inflammation during Streptococcus uberis infection.
• Elucidate L-arginine's molecular regulatory mechanisms in this context.
• Explore potential therapeutic strategies for bacterial mastitis.

Main Methods:

• Utilized a mouse mastitis model infected with Streptococcus uberis.
• Measured miR155 expression levels post-infection.
• Assessed L-arginine levels and amino acid metabolism.
• Investigated the p65 signaling pathway and SOCS6 interactions.
• Evaluated the effects of L-arginine supplementation.

Main Results:

• Streptococcus uberis infection led to increased miR155 and L-arginine depletion.
• Upregulated miR155 promoted inflammation by inhibiting SOCS6-mediated p65 degradation.
• L-arginine supplementation reduced miR155 expression and exerted anti-inflammatory effects.
• Observed severe tissue damage associated with miR155 upregulation and L-arginine depletion.

Conclusions:

• MiR155 plays a pro-inflammatory role in S. uberis infection by modulating the p65 pathway.
• L-arginine exhibits anti-inflammatory properties by inhibiting miR155 production.
• This research offers novel insights into managing bacterial mastitis and ensuring food safety.