Citations

Significance Statement Fractalkine receptor 1 (CX3CR1) mediates macrophage infiltration into the vasculature. In this study, we used humanized mice knocked in with the human CX3CR1 gene and inhibited CX3CR1 signaling using a variable domains of camelid heavy-chain-only molecule (BI 655088) to test the hypothesis that blockade of CX3CR1 results in less of the venous neointimal hyperplasia formation that is associated with arteriovenous fistula (AVF) failure. We also used human samples removed from failed AVFs combined with cell culture experiments. Our results demonstrate a novel role for CX3CR1 in reducing venous stenosis formation in AVFs. Background Fractalkine receptor 1 (CX3CR1) mediates macrophage infiltration and accumulation, causing venous neointimal hyperplasia (VNH)/venous stenosis (VS) in arteriovenous fistula (AVF). The effect of blocking CX3CR1 using an anti–human variable VHH molecule (hCX3CR1 VHH, BI 655088) on VNH/VS was determined using a humanized mouse in which the human CX3CR1 ( hCX3CR1 ) gene was knocked in (KI). Methods Whole-transcriptomic RNA sequencing with bioinformatics analysis was used on human stenotic AVF samples, C57BL/6J, hCX3CR1 KI mice with AVF and CKD, and in in vitro experiments to identify the pathways involved in preventing VNH/VS formation after hCX3CR1 VHH administration. Results Accumulation of CX3CR1 and CD68 was significantly increased in stenotic human AVFs. In C57BL/6J mice with AVF, there was increased Cx3cr1, Cx3cl1, Cd68 , and Tnf-α gene expression, and increased immunostaining of CX3CR1 and CD68. In hCX3CR1-KI mice treated with hCX3CR1 VHH molecule (KI-A), compared with vehicle controls (KI-V), there was increased lumen vessel area and patency, and decreased neointima in the AVF outflow veins. RNA-seq analysis identified TNF- α and NF- κ B as potential targets of CX3CR1 inhibition. In KI-A–treated vessels compared with KI-V, there was decreased gene expression of Tnf- α , Mcp-1 , and Il-1 β ; with reduction of Cx3cl1 , NF- κ B, and Cd68 ; decreased M1, Ly6C, smooth muscle cells, fibroblast-activated protein, fibronectin, and proliferation; and increased TUNEL and M2 staining. In cell culture, monocytes stimulated with PMA and treated with hCX3CR1 VHH had decreased TNF- α , CD68 , proliferation, and migration. Conclusions CX3CR1 blockade reduces VNH/VS formation by decreasing proinflammatory cues.

Background: Heart failure with preserved ejection fraction (HFpEF) is a global public health problem with important regional differences. We investigated these differences in the PARAGON-HF trial (Prospective Comparison of Angiotensin Receptor Neprilysin Inhibitor With Angiotensin Receptor Blocker Global Outcomes in HFpEF), the largest and most inclusive global HFpEF trial. Methods: We studied differences in clinical characteristics, outcomes, and treatment effects of sacubitril/valsartan in 4796 patients with HFpEF from the PARAGON-HF trial, grouped according to geographic region. Results: Regional differences in patient characteristics and comorbidities were observed: patients from Western Europe were oldest (mean 75±7 years) with the highest prevalence of atrial fibrillation/flutter (36%); Central/Eastern European patients were youngest (mean 71±8 years) with the highest prevalence of coronary artery disease (50%); North American patients had the highest prevalence of obesity (65%) and diabetes (49%); Latin American patients were younger (73±9 years) and had a high prevalence of obesity (53%); and Asia-Pacific patients had a high prevalence of diabetes (44%), despite a low prevalence of obesity (26%). Rates of the primary composite end point of total hospitalizations for HF and death from cardiovascular causes were lower in patients from Central Europe (9 per 100 patient-years) and highest in patients from North America (28 per 100 patient-years), which was primarily driven by a greater number of total hospitalizations for HF. The effect of treatment with sacubitril-valsartan was not modified by region (interaction P >0.05). Conclusions: Among patients with HFpEF recruited worldwide in PARAGON-HF, there were important regional differences in clinical characteristics and outcomes, which may have implications for the design of future clinical trials. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01920711.

Abstract Although lung cancer is known to be caused by environmental factors, it has also been shown to have genetic components, and the genetic etiology of lung cancer remains understudied. We previously identified a lung cancer risk locus on 6q23-25 using microsatellite data in families with a history of lung cancer. To further elucidate that signal, we performed targeted sequencing on nine of our most strongly linked families. Two-point linkage analysis of the sequencing data revealed that the signal was heterogeneous and that different families likely had different risk variants. Three specific haplotypes were shared by some of the families: 6q25.3-26 in families 42 and 44, 6q25.2-25.3 in families 47 and 59, and 6q24.2-25.1 in families 30, 33, and 35. Region-based logarithm of the odds scores and expression data identified the likely candidate genes for each haplotype overlap: ARID1B at 6q25.3, MAP3K4 at 6q26, and UTRN (6q24.1) and PHACTR2 (6q24.2). Further annotation was used to zero in on potential risk variants in those genes. All four genes are good candidate genes for lung cancer risk, having been linked to either lung cancer specifically or other cancers. However, this is the first time any of these genes has been implicated in germline risk. Functional analysis of these four genes is planned for future work. Significance: This study identifies four genes associated with lung cancer risk, which could help guide future lung cancer prevention and treatment approaches.

Abstract Background Limited data exist on high-sensitivity cardiac troponin (hs-cTn) for risk-stratification in COVID-19. Methods We conducted a multicenter, retrospective, observational, US-based study of COVID-19 patients undergoing hs-cTnT. Outcomes included short-term mortality (in-hospital and 30-days post-discharge) and a composite of major adverse events, including respiratory failure requiring mechanical ventilation, cardiac arrest, and shock within the index presentation and/or mortality during the index hospitalization or within 30-days post-discharge. Results Among 367 COVID-19 patients undergoing hs-cTnT, myocardial injury was identified in 46%. They had a higher risk for mortality (20% vs 12%, P < 0.0001; unadjusted HR 4.44, 95% CI 2.13–9.25, P < 0.001) and major adverse events (35% vs. 11%, P < 0.0001; unadjusted OR 4.29, 95% CI 2.50–7.40, P < 0.0001). Myocardial injury was associated with major adverse events (adjusted OR 3.84, 95% CI 2.00–7.36, P < 0.0001) but not mortality. Baseline (adjusted OR 1.003, 95% CI 1.00–1.007, P = 0.047) and maximum (adjusted OR 1.005, 95% CI 1.001–1.009, P = 0.0012) hs-cTnT were independent predictors of major adverse events. Most (95%) increases were due to myocardial injury, with 5% (n = 8) classified as type 1 or 2 myocardial infarction. A single hs-cTnT <6 ng/L identified 26% of patients without mortality, with a 94.9% (95% CI 87.5–98.6) negative predictive value and 93.1% sensitivity (95% CI 83.3–98.1) for major adverse events in those presenting to the ED. Conclusions Myocardial injury is frequent and prognostic in COVID-19. While most hs-cTnT increases are modest and due to myocardial injury, they have important prognostic implications. A single hs-cTnT <6 ng/L at presentation may facilitate the identification of patients with a favorable prognosis.

Abstract Objective: Fibromuscular dysplasia (FMD) is an arteriopathy that presents mainly by hypertension, stroke or dissection. Diagnosis is often made in middle-aged women with few cardiovascular risk factors. We aim at identifying common genetic variants associated to FMD. Design and method: We tested ∼6.5 million common genetic variants (MAF > 0.01) in 1962 cases and 7100 controls from 6 studies using variants and gene-based association analyses. Participants were of European ancestry, with similar characteristics (91% multifocal, 88% women), diagnosis methods and inclusion/exclusion criteria. Transcriptome-wide association (TWAS), eQTL, gene expression by sex and colocalization analyses used expression data in arteries from GTEx and/or FMD patients and matched controls. Open chromatin regions were defined using ATAC-Seq on primary human fibroblasts, smooth muscle and endothelial cells. Genetic correlations were assessed using summary statistics from UKBiobank and/or published studies by linkage disequilibrium score regression and multi-trait-based conditional and joint analyses (mtCOJO). Results: We confirmed the previously identified PHACTR1 locus and identified three new loci (LRP1, ATP2B1, and LIMA1) associated with FMD. TWAS in arteries identified one additional locus (SLC24A3). Through integration of annotation datasets, we provided prioritization of variants and genes. These are consistently and specifically expressed in fibroblasts, smooth muscle cells, and arterial tissues. PHACTR1 and SLC24A3 showed sex differences in gene expressions consistent with the direction of effects of FMD risk alleles. FMD genes are involved in regulatory mechanisms related to actin cytoskeleton and intracellular calcium homeostasis, two mechanisms central to vascular contraction. We found significant genetic overlaps between FMD and blood pressure traits, for the associated loci and globally at the genome level, but demonstrated that hypertension is not driving the genetic association with FMD. We also found positive genetic correlations with migraine and intracranial aneurysm, and an inverse correlation with coronary artery disease, independently from the genetics of blood pressure. Conclusions: We describe robustly associated loci and genes with FMD and provide several new leads toward understanding biological mechanisms of stenosis and dissection in young women in the absence of atherosclerosis, which shares part of its genetic basis with more common cardiovascular and neurovascular diseases.

Background and aim Mechanical thrombectomy (MT) for large vessel occlusion often requires multiple passes to retrieve the entire thrombus load. In this multi-institutional study we sought to examine the composition of thrombus fragments retrieved with each pass during MT. Methods Patients who required multiple passes during thrombectomy were included. Histopathological evaluation of thrombus fragments retrieved from each pass was performed using Martius Scarlet Blue staining and the composition of each thrombus component including RBC, fibrin and platelet was determined using image analysis software. Results 154 patients underwent MT and 868 passes was performed which resulted in 263 thrombus fragments retrieval. The analysis of thrombus components per pass showed higher RBC, lower fibrin and platelet composition in the pass 1 and 2 when compared to pass 3 and passes 4 or more combined (P values <0.05). There were no significant differences between thrombus fragments retrieved in pass 1 and pass 2 in terms of RBC, WBC, fibrin, and platelet composition (P values >0.05). Similarly, when each composition of thrombus fragments retrieved in pass 3 and passes 4 or more combined were compared with each other, no significant difference was noted (P values >0.05). Conclusion Our findings confirm that thrombus fragments retrieved with each pass differed significantly in histological content. Fragments in the first passes were associated with lower fibrin and platelet composition compared to fragments retrieved in passes three and four or higher. Also, thrombus fragments retrieved after failed pass were associated with higher fibrin and platelet components.

BackgroundEarly detection and grading of pancreatic fibrosis (PF) are important and challenging clinical goals.PurposeTo determine main pancreatic duct (MPD) diameter, pancreatic thickness, and grades of PF via magnetic resonance elastography (MRE), T1 mapping, and intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI), assessing respective diagnostic performances.Study TypeProspective.SubjectsHistopathologic and imaging records (MRE, T1 mapping, and IVIM‐DWI) generated by 144 patients between December 2018 and May 2020 were collected for analysis. Grades of PF were distributed as follows: F0, 82; F1, 22; F2, 22; and F3, 18.Field Strength/Sequence3 T pancreatic MRI, encompassing MRE, T1 mapping, and IVIM‐DWI.AssessmentIn all patients, T1 relaxation times, pancreatic stiffness values, IVIM‐DWI parameters, MPD diameter, and pancreatic thickness were measured.Statistical TestsReceiver operating characteristic (ROC) analysis served to assess imaging parameters useful in diagnosing PF. To identify relations between specific parameters and grades of PF, logistic regression analysis was invoked.ResultsBoth pancreatic stiffness (r = 0.754; P < 0.001) and T1 relaxation time (r = 0.433; P < 0.001) correlated significantly with PF (%). To determine PF grades ≥F1, a combined model (area under the curve [AUC] = 0.906) performed significantly better than pancreatic stiffness (AUC = 0.855; P < 0.001) or T1 relaxation time (AUC = 0.754; P < 0.001) alone. For PF grades ≥F2 or grade F3, both the combined model (≥F2: AUC = 0.910; F3: AUC = 0.939) and pancreatic stiffness (≥F2: AUC = 0.906; F3: AUC = 0.929) outperformed T1 relaxation time (≥F2: AUC = 0.768 [P = 0.005 and P = 0.004, respectively]; F3: AUC = 0.816 [both P < 0.005]). All IVIM‐DWI parameters generated AUC values <0.700.Data ConclusionA combination of MRE and T1 mapping seems promising in diagnosing various grades of PF, particularly at an early stage.Level of Evidence1Technical EfficacyStage 2

Background: Percutaneous transluminal renal angioplasty (PTRA) confers clinical and mortality benefits in select ‘high-risk’ patients with renovascular disease (RVD). Intra-renal-delivered extracellular vesicles (EVs) released from mesenchymal stem/stromal cells (MSCs) protect the kidney in experimental RVD, but have not been compared side-by-side to clinically applied interventions, such as PTRA. We hypothesized that MSC-derived EVs can comparably protect the post-stenotic kidney via direct tissue effects. Methods: Five groups of pigs (n = 6 each) were studied after 16 weeks of RVD, RVD treated 4 weeks earlier with either PTRA or MSC-derived EVs, and normal controls. Single-kidney renal blood flow (RBF) and glomerular filtration rate (GFR) were assessed in vivo with multi-detector CT, and renal microvascular architecture (3D micro CT) and injury pathways ex vivo. Results: Despite sustained hypertension, EVs conferred greater improvement of intra-renal microvascular and peritubular capillary density compared to PTRA, associated with attenuation of renal inflammation, oxidative stress, and tubulo-interstitial fibrosis. Nevertheless, stenotic kidney RBF and GFR similarly rose in both PTRA- and EV-treated pigs compared RVD + Sham. mRNA sequencing reveled that EVs were enriched with pro-angiogenic, anti-inflammatory, and antioxidants genes. Conclusion: MSC-derived EVs elicit a better preservation of the stenotic kidney microvasculature and greater attenuation of renal injury and fibrosis compared to PTRA, possibly partly attributed to their cargo of vasculo-protective genes. Yet, both strategies similarly improve renal hemodynamics and function. These observations shed light on diverse mechanisms implicated in improvement of post-stenotic kidney function and position EVs as a promising therapeutic intervention in RVD.