The Effects of miR-22-3p on Differentiation of Human Dental Pulp Stem Cells into Neural Progenitor-Like Cells

Stem cell treatment shows promise in treating conditions such as neurodegenerative disorders and spinal injuries, but its effectiveness is hampered by cell death and apoptosis. Improving the differentiation of MSCs into neural cells could enhance their therapeutic potential. The role of miR-22-3p in human dental pulp stem cells (HDPSCs), a superior alternative to treat neurodegenerative disorders, and its molecular mechanisms during neural differentiation remain elusive. Therefore, we investigated the miR-22-3p transfections during HDPSC differentiation into neural progenitor-like cells (NPCs) and elucidated the molecular processes through transcriptomic analysis. HDPSCs were differentiated into NPCs after transfection with a miR-22-3p mimic and inhibitor; the differentiation process was assessed by cell viability and expression of Nestin protein. mRNA sequencing on days 1, 3, and 7 of the differentiation process identified several differentially expressed genes (DEGs). Cytoscape and functional enrichment analysis pinpointed central hub genes among the DEGs and uniquely expressed genes. miR-22-3p mimic hindered HDPSC differentiation by reducing proliferation and increasing apoptosis. It downregulated genes linked to extracellular matrix, synaptic and vesicle functions, lipid metabolism, JAK-STAT, and cell cycle pathways across all days while activating proteasome and digestion pathways. In contrast, miR-22-3p inhibition boosts NPC proliferation and elevates Nestin neural marker protein expression. Altogether, miR-22-3p disrupts synapse functioning and lipid metabolism pathways, resulting in apoptosis and death. Conversely, inhibiting miR-22-3p enhances neural differentiation and proliferation of HDPSCs, suggesting its potential application in generating a greater quantity of NPCs and neurons.