Objective: PCSK9 (proprotein convertase subtilisin/kexin type 9) plays a critical role in cholesterol metabolism via the PCSK9-LDLR (low-density lipoprotein receptor) axis in the liver; however, evidence indicates that PCSK9 directly contributes to the pathogenesis of various diseases through mechanisms independent of its LDL-cholesterol regulation. The objective of this study was to determine how PCSK9 directly acts on vascular smooth muscle cells (SMCs), contributing to degenerative vascular disease. Approach and Results: We first examined the effects of PCSK9 on cultured human aortic SMCs. Overexpression of PCSK9 downregulated the expression of ApoER2 (apolipoprotein E receptor 2), a known target of PCSK9. Treatment with soluble recombinant human ApoER2 or the DNA synthesis inhibitor, hydroxyurea, inhibited PCSK9-induced polyploidization and other cellular responses of human SMCs. Treatment with antibodies against ApoER2 resulted in similar effects to those observed with PCSK9 overexpression. Inducible, SMC-specific knockout of accelerated neointima formation in mouse carotid arteries and reduced age-related arterial stiffness. PCSK9 was expressed in SMCs of human atherosclerotic lesions and abundant in the "shoulder" regions of vulnerable atherosclerotic plaques. PCSK9 was also expressed in SMCs of abdominal aortic aneurysm, which was inversely related to the expression of smooth muscle α-actin.
Conclusions: Our findings demonstrate that PCSK9 inhibits proliferation and induces polyploidization, senescence, and apoptosis, which may be relevant to various degenerative vascular diseases.
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http://dx.doi.org/10.1161/ATVBAHA.121.316902 | DOI Listing |
Exp Physiol
January 2025
Robinson Research Institute, University of Adelaide, Adelaide, South Australia, Australia.
The mechanisms linking maternal asthma (MA) exposure in utero and subsequent risk of asthma in childhood are not fully understood. Pathological airway remodelling, including reticular basement membrane thickening, has been reported in infants and children who go on to develop asthma later in childhood. This suggests altered airway development before birth as a mechanism underlying increased risk of asthma in children exposed in utero to MA.
View Article and Find Full Text PDFInt J Gynecol Pathol
January 2025
Departments of Pathology.
The morphologic features of uterine smooth muscle tumors (USMTs) are subject to interobserver variability and are complicated by consideration of features of fumarate hydratase deficiency (FHd) and other morphologic subtypes, with difficult cases occasionally diagnosed as smooth muscle tumor of uncertain malignant potential (STUMP). We compare immunohistochemical findings and detailed morphologic analysis of 45 USMTs by 4 fellowship-trained gynecologic pathologists with comprehensive molecular analysis, focusing on FHd leiomyomas (n=15), compared to a variety of other USMTs with overlapping morphologic features, including 9 STUMPs, 8 usual-type leiomyomas (ULM), 11 apoplectic leiomyomas, and 2 leiomyomas with bizarre nuclei (LMBN). FHd leiomyomas, defined by immunohistochemical (IHC) loss of FH and/or 2SC accumulation, showed FH mutations and/or FH copy loss in all cases, with concurrent TP53 mutations in 2 tumors.
View Article and Find Full Text PDFAnal Chem
January 2025
Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, China.
Microelectrodes offer exceptional sensitivity, rapid response, and versatility, making them ideal for real-time detection and monitoring applications. Photoelectrochemical (PEC) sensors have shown great value in many fields due to their high sensitivity, fast response, and ease of operation. Nevertheless, conventional PEC sensing relies on cumbersome external light sources and bulky electrodes, hindering its miniaturization and implantation, thereby limiting its application in real-time disease monitoring.
View Article and Find Full Text PDFRationale: Airflow obstruction refractory to β2 adrenergic receptor (β2AR) agonists is an important clinical feature of infant respiratory syncytial virus (RSV) bronchiolitis, with limited treatment options. This resistance is often linked to poor drug delivery and potential viral infection of airway smooth muscle cells (ASMCs). Whether RSV inflammation causes β2AR desensitization in infant ASMCs is unknown.
View Article and Find Full Text PDFFront Pharmacol
January 2025
Respiratory Department II, National Clinical Research Center for Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
Multisystemic smooth muscle dysfunction syndrome (MSMDS) is an autosomal dominant disorder caused by mutations in the gene, resulting in variable clinical manifestation and multi-organ dysfunction. Interstitial lung disease (ILD) is a rare phenotype of this condition. We describe a rare infant case of an 8-month-old boy who presented with progressively worsening dyspnea, along with intermittent episodes of respiratory distress and cyanosis since birth.
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