Heterogeneity study on MiRNA expression in islet cells of rat pancreatic head and tail

As a vital endocrine organ, the pancreas exhibits differences in anatomical structure and microenvironment between its head and tail. However, whether there is heterogeneity in miRNA expression within the islet cells of these two regions and what biological significance this heterogeneity may entail remain unclear.

This study utilized high-throughput sequencing to analyze the miRNA expression profiles in the islet cells from the pancreatic head and tail in rats. The TargetScan and miRDB databases were used to predict target genes of the differentially expressed miRNAs (DEmiRNAs). The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases were utilized to analyze the target genes. The key miRNA was verified by qRT-PCR.

A total of 445 miRNAs were detected in the islet cells of the pancreatic head and tail, among which 69 showed significant differences (|log2 fold change|>0.585 and P<0.05). Compared with the pancreatic tail, 28 miRNAs were upregulated and 41 miRNAs were downregulated in the pancreatic head. Bioinformatics analysis revealed that these target genes were significantly enriched in functions such as negative regulation of cellular process, anatomical structure development, intracellular organelle, pancreatic cancer, insulin resistance, MAPK signaling, Wnt signaling, and Hippo signaling. In addition, KEGG analysis of target genes showed that miR-124-3p was in several pathways, such as the insulin signaling pathway, endocrine resistance, small cell lung cancer, and other pathways in cancer. qRT-PCR results showed that miR-124-3p was significantly upregulated in the pancreatic head.

Our findings provide novel insights into the heterogeneity of miRNA expression in the pancreas and the molecular mechanisms underlying pancreatic cancer, offering potential targets for future diagnostic and therapeutic strategies.