Expression profiles and circulation dynamics of rat mesenteric lymph microRNAs

Area of Science:

• Immunology
• Molecular Biology
• Physiology

Background:

• Mesenteric lymph is crucial for immune cell transport and homeostasis.
• Limited research exists on mesenteric lymph microRNA (miRNA) profiles and circulation.
• Understanding lymph miRNA dynamics is vital for immune and metabolic research.

Purpose of the Study:

• To comprehensively analyze miRNAs in normal rodent mesenteric lymph.
• To investigate the presence and circulation of lymph miRNAs, particularly in exosomes.
• To determine the in vivo fate and organ distribution of mesenteric lymph miRNAs.

Main Methods:

• Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) array analysis of 375 miRNAs in rat mesenteric lymph.
• Differential centrifugation to assess exosomal presence of miR-150.
• In vivo tracing of cel-miR-238-3p-labeled exosomes derived from rat small intestine epithelial cells (IEC-6).

Main Results:

• Detected 287 miRNAs in mesenteric lymph, with 21 significantly different from plasma.
• Identified cell-free miR-150 within the exosome-containing microsomal fraction.
• In vivo studies showed exosomal cel-miR-238-3p predominantly accumulating in the lungs, indicating lung as the primary clearance organ.

Conclusions:

• Mesenteric lymph harbors a distinct miRNA profile compared to plasma.
• miRNAs are present in exosomes within mesenteric lymph.
• Exosomal miRNAs from mesenteric lymph are cleared primarily by the lungs, suggesting a role in lung gene expression modulation.