Biomolecules

Vascular remodeling is a characteristic pathological feature of various vascular diseases, including atherosclerosis, restenosis following vascular injury, hypertension, and aneurysms. The phenotypic switching of vascular smooth muscle cells (VSMCs) acts as a key driver of vascular remodeling. Under specific pathological stimuli, VSMCs rapidly transition from a contractile to a dedifferentiated phenotype, characterized by enhanced proliferation, migration, and secretory activity. Chromatin remodeling, a core mechanism of epigenetic regulation, orchestrates dynamic changes in chromatin structure and function through ATP-dependent remodeling complexes, histone-modifying enzymes, and DNA methyltransferases. These components collectively translate mechanical stress, metabolic disturbances, and inflammatory signals into reversible epigenetic modifications, thereby precisely regulating VSMC phenotypic switching. As such, chromatin remodeling represents a critical node for therapeutic intervention in vascular remodeling-related diseases. In recent years, a growing body of research has focused on the role of chromatin remodelers in regulating VSMC phenotype. In this review, we focus on the roles of ATP-dependent chromatin-remodeling factors and chromatin-modifying enzymes in the control of gene expression of VSMC phenotype switching. Firstly, we summarize the latest insights into chromatin remodeling and VSMC phenotypic switching, and then discuss recent advances in the identification and functional characterization of chromatin remodeling molecules, emphasizing their implications for VSMC behavior. Finally, we highlight the translational potential of targeting chromatin remodelers in the development of clinical therapies for vascular remodeling diseases and outline future directions for research in this field.

Electronic cigarettes (e-cigarettes) have emerged as a prevalent substitute for conventional cigarettes, garnering perceptions of being a safer option for health. Nicotine addicts use e-cigarettes to cease smoking. These products have also become common among young people because of their taste, smell, and attractive appearance. However, accumulating experimental and clinical evidence indicates that e-cigarette use is not risk-free. The inhalation of e-cigarette aerosols exposes users and their non-using peers to a complex mixture of chemical compounds, including aldehydes, heavy metals, and flavoring agents, many of which possess pro-oxidative and pro-inflammatory properties. This review summarizes and critically analyzes current evidence on the molecular and cellular mechanisms underlying the biological effects of e-cigarette aerosols. Particular attention is given to excessive production of reactive oxygen species, mitochondrial dysfunction, DNA damage, and the activation of redox-sensitive signaling pathways, including NF-κB and NRF2. These molecular alterations may trigger acute and, with prolonged exposure, chronic oxidative stress and inflammation, which in turn can affect gene expression, protein function, and metabolic pathways. While molecular and experimental studies often demonstrate adverse biological responses to e-cigarette aerosols, the translation of these findings into long-term clinical outcomes remains an area of ongoing investigation.

Human prostamide/prostaglandin F synthase (PGFS) catalyzes the NADPH-dependent conversion of prostaglandin H₂ (PGH2) to prostaglandin F₂α that plays a key role in regulating intraocular pressure and labor. Despite its physiological importance, structural and biochemical information of the human PGFS has been limited because of difficulties in obtaining sufficient quality of PGFS wild-type crystal and short half-life of PGH2. Here, we report the crystal structure of human PGFS with two active site mutations, C44S/C47S double mutant (DM), which mimics the reduced active form of the CXXC motif of human PGFS. Structural analysis revealed that PGFS DM adopts a typical thioredoxin (Trx)-like fold. Analysis of B-factors and MD simulations reveals that Tyr108–Asp124 is an intrinsically flexible region, devoid of any stabilizing crystal contacts. Unlike canonical Trx-like proteins, Pro167 in PGFS adopts a trans-conformation, inducing a specific Arg40 side chain localization that creates a positive charge near the CXXC motif. Activation of PGFS by reduction of disulfide bond in the CXXC motif enhanced the thermal stability via core stabilization, yet an unexpected increase in the structural disorder was detected with CD spectroscopy, especially upon ligand binding. These findings collectively establish PGFS as a structurally distinct and redox-regulated enzyme. Our results provide novel molecular insights into PGFS as an underexplored but promising therapeutic target.