The roles and mechanisms of A-kinase anchoring protein 1 (AKAP1) in vascular smooth muscle cell (VSMC) phenotypic modulation and neointima formation are currently unknown. AKAP1 is a mitochondrial PKA-anchored protein and maintains mitochondrial homeostasis. This study aimed to investigate how AKAP1/PKA signaling plays a protective role in inhibiting VSMC phenotypic transformation and neointima formation by regulating mitochondrial fission. The results showed that both PDGF-BB treatment and balloon injury reduced the transcription, expression, and mitochondrial anchoring of AKAP1. In vitro, the overexpression of AKAP1 significantly inhibited PDGF-BB mediated VSMC proliferation and migration, whereas AKAP1 knockdown further aggravated VSMC phenotypic transformation. Additionally, in the balloon injury model in vivo, AKAP1 overexpression reduced neointima formation, the muscle fiber area ratio, and rat VSMC proliferation and migration. Furthermore, PDGF-BB and balloon injury inhibited Drp1 phosphorylation at Ser637 and promoted Drp1 activity and mitochondrial midzone fission; AKAP1 overexpression reversed these effects. AKAP1 overexpression also inhibited the distribution of mitochondria at the plasma membrane and the reduction of PKARIIβ expression induced by PDGF-BB, as evidenced by an increase in mitochondria-plasma membrane distance as well as PKARIIβ protein levels. Moreover, the PKA agonist promoted Drp1 phosphorylation (Ser637) and inhibited PDGF-BB-mediated mitochondrial fission, cell proliferation, and migration. The PKA antagonist reversed the increase in Drp1 phosphorylation (Ser637) and the decline in mitochondrial midzone fission and VSMC phenotypic transformation caused by AKAP1 overexpression. The results of this study reveal that AKAP1 protects VSMCs against phenotypic modulation by improving Drp1 phosphorylation at Ser637 through PKA and inhibiting mitochondrial fission, thereby preventing neointima formation.

Chronic hepatitis C is a serious liver disease that often results in cirrhosis or hepatocellular carcinoma. The aim of this study was to assess the association of human leukocyte antigen-DP (HLA-DP) variants with risk of chronic hepatitis C virus (HCV) or anti-F antibody generation. We selected two single nucleotide polymorphisms (SNPs) in a region including HLA-DPA1 (rs3077) and HLA-DPB1 (rs9277534) and genotyped SNPs in 702 cases and 342 healthy controls from the Chinese population using TaqMan SNP genotyping assay. Moreover, the exon 2 of the HLA-DPA1 and HLA-DPB1 genes were amplified and determined by sequencing-based typing (SBT). The results showed that rs3077 significantly increased the risk of chronic HCV infection in additive models and dominant models (odds ratio (OR) = 1.32 and 1.53). The rs3077 also contributed to decrease the risk of anti-F antibody generation in additive models and dominant models (OR = 0.46 and 0.56). Subsequent analyses revealed the risk haplotypes (DPA1*0103-DPB1*0501 and DPA1*0103-DPB1*0201) and protective haplotypes (DPA1*0202-DPB1*0501 and DPA1*0202-DPB1*0202) to chronic HCV infection. Moreover, we also found that the haplotype of DPA1*0103-DPB1*0201 and DPA1*0202-DPB1*0202 were associated with the anti-F antibody generation. Our findings show that genetic variants in HLA-DP gene are associated with chronic HCV infection and anti-F antibody generation.

Vascular restenosis, a pathological recurrence of lumen narrowing following interventions, remains a major limitation to the long-term success of vascular procedures. Its development is centrally driven by neointimal hyperplasia, a process orchestrated by endothelial injury, phenotypic switching of vascular smooth muscle cells (VSMCs) from a contractile to a synthetic state, and a coordinated inflammatory response. Despite advancements, the molecular mechanisms are not fully elucidated, and specific, effective pharmacotherapies are still lacking. This review systematically delineates the pathophysiology, focusing on these three core elements, and provides a comprehensive landscape of the complex signaling networks and molecular targets. We extensively cover protein-based regulators—including pro-proliferative factors (e.g., LSD1, FGF10), protective mediators (e.g., CGRP, A20), dual-action molecules with isoform-specific or context-dependent effects (e.g., KLFs, HDACs), endothelial repair targets (e.g., VEGF), and molecules that coordinately target both VSMCs and endothelial cells (ECs) (e.g., PERK, METTL3). We place significant focus on non-coding RNAs, particularly microRNAs (miRNAs) like miR-221/222, which fine-tune multiple targets in both VSMCs and ECs, offering unique precision. We critically evaluate the therapeutic significance and clinical translation potential, while addressing formidable challenges: functional duality within protein families (e.g., KLFs, HDACs), difficulties in cell-specific delivery and stability for miRNA therapies, and a narrow therapeutic window. Additionally, we highlight the emerging role of the vascular adventitia as a key source of regulatory signals (e.g., FGF10). By integrating insights from molecular mechanisms to therapeutic interventions, this work serves as a valuable reference for identifying novel strategies to combat neointima formation and vascular restenosis.