Citations

BACKGROUND: Whereas antiphospholipid syndrome (APS) is best known for increasing the risk of macrovascular thrombosis, APS vasculopathy is characterized by the abnormal proliferation of endothelial and smooth muscle cells, leading to occlusion of small blood vessels in the skin, kidneys, and heart, among other organs. The underlying mechanisms remain unclear, and targeted treatment options for patients with APS are lacking. METHODS: To identify and analyze APS microvascular endothelial cells (MVECs), skin biopsies of patients with APS complicated by livedo racemosa were characterized using single-cell RNA sequencing. CCN1 (cellular communication network factor 1) and CCN2 were identified in skin and kidney biopsies by immunofluorescence microscopy and in plasma by ELISA. Healthy dermal MVECs were cultured with APS patient–derived serum or immunoglobulin G (IgG), and relevant signaling pathways were characterized using quantitative PCR, immunoblotting, and immunofluorescence microscopy. The proliferation and migration of vascular smooth muscle cells were determined after exposure to conditioned medium from APS IgG–stimulated MVECs. A mouse model of APS IgG–accelerated neointima formation was developed. Anti-CCN2 monoclonal antibodies were tested in vascular smooth muscle cell functional assays and the mouse model. RESULTS: Increased endothelial cell expression of CCN1 and CCN2 was identified by single-cell RNA sequencing and further confirmed in APS skin by microscopy as well as in APS plasma by ELISA. Exposure of healthy MVECs to patient IgG triggered the upregulation of CCN1 and CCN2 via Toll-like receptor 4– and YAP1 (yes-associated protein 1)–mediated signaling. CCN2, originating from APS IgG–stimulated MVECs led to the proliferation and migration of vascular smooth muscle cells, phenotypes that were inhibited by an anti-CCN2 antibody or depletion of EGFR (epidermal growth factor receptor). We further observed increased expression of CCN2, along with evidence of YAP1 nuclear translocation, in kidney vessels of APS nephropathy biopsies. Finally, CCN2 inhibition with an anti-CCN2 monoclonal antibody significantly reduced neointima thickening and cell proliferation in a mouse model of APS IgG–accelerated neointima formation. CONCLUSIONS: This study revealed activation of YAP1-mediated signaling in APS dermal microvessels and demonstrated that the YAP1 target CCN2 plays a role in facilitating pro-proliferative communication between MVECs and vascular smooth muscle cells. These findings offer insights into the cellular and molecular mechanisms underlying APS vasculopathy, providing potential therapeutic targets for patients.

Objectives: The development and evaluation of percutaneous thrombectomy devices for pulmonary embolism (PE) pose a need for standardized large in vivo models with representative anatomical and physiological conditions and clots analogs. In this study, we present a swine model of PE model employing human-derived clot analogs. Material and Methods: Baseline angiographic and physiological pressure measurements were obtained in six adult Yorkshire pigs (45–65 kg) and results were benchmarked for interspecies comparison with published human data using fluoroscopic examinations, intra-arterial pressure measurements, and histologic studies. Then, clot analogs were created ex vivo employing banked human blood and a subset incubated in iodinated contrast for fluoroscopic visualization. Clot analogs were then embolized via a femoral venous access and angiographic/physiological consequences were evaluated. Results: The main, right, and left pulmonary artery diameters were 24 ± 1.1 mm, 16.5 ± 0.8 mm, and 12.6 ± 1.2 mm, respectively. The angle between the main pulmonary artery at the bifurcation point was approximately 90–95°. The clot analogs were heterogeneous and had increased fibrin content along the clot length. The overall composition was 96.63% red blood cell (RBC)/3.37% fibrin in the initial section, 48.85% RBC/51.15% fibrin in the intermediate section, and 3.44% RBC/96.56% fibrin in the final section. Embolization of the clot analogs resulted in distal occlusion of the right and left pulmonary arteries. Conclusions: This swine model coupled with clot analog is able to accurately mimic human anatomical and physiological conditions in PE making it feasible for the evaluation of pulmonary thrombectomy devices.

Two lysine acyltransferases govern histone H3 propionylation at lysine 23 in normal and pathological conditions.

Abstract Background Vedolizumab effectiveness estimates immediately after Food and Drug Administration (FDA) approval for ulcerative colitis (UC) and Crohn’s disease (CD) are limited by use in refractory populations. We aimed to compare treatment patterns and outcomes of vedolizumab in 2 time frames after FDA approval. Methods We used 2 data sets for time trend analysis, an academic multicenter vedolizumab consortium (VICTORY) and the Truven MarketScan database, and 2 time periods, May 2014–June 2015 (Era 1) and July 2015–June 2017 (Era 2). VICTORY cumulative 12-month clinical remission, corticosteroid-free remission, and mucosal healing rates, and Truven 12-month hospitalization and surgery rates, were compared between Eras 1 and 2 using time-to-event analyses. Results A total of 3661 vedolizumab-treated patients were included (n = 1087 VICTORY, n = 2574 Truven). In both cohorts, CD and UC patients treated during Era 2 were more likely to be biologic naïve. Compared with Era 1, Era 2 CD patients in the VICTORY consortium had higher rates of clinical remission (31% vs 40%, P = 0.03) and mucosal healing (42% vs 58%, P < 0.01). These trends were not observed for UC. In the Truven database, UC patients treated during Era 2 had lower rates of inflammatory bowel disease–related hospitalization (22.4% vs 9.6%, P < 0.001) and surgery (17.2% vs 9.4%, P = 0.008), which was not observed for CD. Conclusion Since FDA approval, remission and mucosal healing rates have increased for vedolizumab-treated CD patients, and vedolizumab-treated UC patients have had fewer hospitalizations and surgeries. This is likely due to differences between patient populations treated immediately after drug approval and those treated later.