Effects of miR-214 on adenosine A2A receptor and carboxymethyl chitosan nanoparticles on the function of keloid fibroblasts and their mechanisms

This work prepared and investigated the impact of carboxymethyl chitosan nanoparticles (MC-NPs) on the proliferative capability of keloid fibroblasts (KFBs) while analyzing the mechanistic roles of miR-214 and adenosine A2A receptor (A2AR) in fibroblasts within hypertrophic scars. MC-NPs were synthesized through ion cross-linking, were characterized using transmission electron microscopy (TEM) and laser particle size scattering. The influence of MC-NPs on the proliferation capacity of KFBs was assessed using the MTT method. Changes in the expression levels of miR-214 and A2AR in KFBs, normal skin fibroblasts (NFBs), hypertrophic scar tissue, and normal skin tissue were analyzed. KFBs were categorized into anti-miR-214, anti-miR-NC, miR-214 mimics, miR-NC, si-A2AR, si-con, anti-miR-214+ si-con, and anti-miR-214+ si-A2AR groups. Bioinformatics target prediction was conducted to explore the interaction between miR-214 and A2AR. Real-time quantitative PCR and immunoblotting (WB) were employed to detect the expression levels of miR-214, A2AR, apoptotic protein Bax, and TGF-β in different cells. Cell counting kit-8 (CCK8) and flow cytometry were employed to assess cell proliferation activity and apoptosis. The results indicated that MC-NPs exhibited spherical particles with an average diameter of 236.47 ± 4.98 nm. The cell OD value in the MC-NPs group was lower than that in KFBs (P < 0.05). The mRNA levels of miR-214 in KFBs and hypertrophic scar tissue were lower than those in NFBs and normal tissue (P < 0.001), while the mRNA and protein levels of A2AR were significantly elevated (P < 0.05). Compared to the control group and anti-miR-NC, the anti-miR-214 group showed significantly increased cell OD values and Bcl-2 protein expression (P < 0.001), decreased levels of apoptotic gene Bax protein, TGF-β gene mRNA, and protein expression (P < 0.001). Continuous complementary binding sites were identified between miR-214 and A2AR. Compared to the control group, the si-A2AR group exhibited a significant decrease in A2AR gene mRNA and protein expression levels (P < 0.001), reduced cell viability (P < 0.001), increased apoptosis rate (P < 0.001), and a significant elevation in TGF-β protein expression (P < 0.001). miR-214 targetedly regulated the expression of A2AR, inducing changes in TGF-β content, promoting the proliferation of keloid fibroblasts, and inhibiting cell apoptosis.