Distinct RNA transcriptome patterns are potentially associated with angiogenesis in Tie2-expressing monocytes

Area of Science:

• Immunology
• Molecular Biology
• Oncology

Background:

• Tie2-expressing monocytes (TEMs) are a novel monocyte subset with proposed pro-angiogenesis roles in tumors.
• The molecular mechanisms underlying TEMs' pro-angiogenesis capacity are not well understood.
• The role of non-coding RNAs (miRNAs, lncRNAs) in TEM differentiation and function remains largely unexplored.

Purpose of the Study:

• To comprehensively analyze the RNA transcriptome of TEMs, including non-coding RNAs.
• To identify differentially expressed mRNAs, lncRNAs, and miRNAs in TEMs compared to Tie2(-) monocytes.
• To elucidate the functional implications of these transcriptomic changes, particularly in relation to angiogenesis.

Main Methods:

• Isolation of TEMs and Tie2(-) monocytes from peripheral blood of healthy adults.
• High-throughput RNA sequencing using Agilent miRNA and lncRNA microarrays.
• Hierarchical clustering for transcriptome pattern analysis.
• Quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) for gene expression validation.
• Gene Ontology (GO) functional annotation and pathway analysis.
• Prediction of miRNA targets and analysis of lncRNA cis/trans-regulation.

Main Results:

• A distinct RNA transcriptome profile was identified in TEMs compared to Tie2(-) monocytes.
• Significant dysregulation of 141 mRNAs, 142 lncRNAs, and 75 miRNAs was observed in TEMs.
• Up-regulated mRNAs in TEMs were associated with blood vessel remodeling and epithelial cell proliferation.
• Insulin-like growth factor 1 (IGF1) mRNA was identified as a key player in these pathways.

Conclusions:

• TEMs possess a unique transcriptome characterized by dysregulated coding and non-coding RNAs.
• These transcriptomic alterations suggest a role for TEMs in pathways relevant to tumor angiogenesis.
• Further investigation into the identified non-coding RNAs and their regulatory roles is warranted to understand TEM function in angiogenesis.