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Biology subjects

Finn, A. V.

Publications and source records attributed to Finn, A. V..

5 recordsLinked to original sources

RNA polymerase loss by nuclear rupture drives LMNA cardiomyopathy

Localized rupture of the nuclear envelope has recently been reported in various pathologies, including cancer 1,2, neurodegenerative disease 3-5, myocardial infarction 6, as well as dilated cardiomyopathy caused by Lamin A/C gene mutations (LMNA-DCM) 7. Whether and how nuclear rupture contributes to disease remains unknown. Here, we report that nuclear rupture causes global transcriptional deficiency in a mouse model of LMNA-DCM. We observed that ruptured nuclei lost RNA polymerase II, leading to downregulation of numerous genes essential for cardiomyocyte structure and function. We identified endogenous resealing of nuclear rupture as a cardioprotective mechanism in LMNA-DCM mouse hearts. Resealing involved the ESCRT-III membrane remodeling complex recruited to nuclear rupture sites. Resealed nuclei restored transcription while inhibiting ESCRT-III activity accelerated cardiomyopathy. However, resealed nuclei were short-lived: they re-ruptured at twice the rate of resealing. A kinetic model predicted progressive accumulation of ruptured nuclei despite ongoing resealing. Consistently, a human LMNA-DCM heart contained numerous ruptured nuclei at disease presentation. These findings linked nuclear rupture to organ deterioration through global transcriptional deficiency and suggested rupture resealing as a critical modifier of nuclear rupture-associated conditions.

molecular biology↗

Polygenic Risk Score Associates with Atherosclerotic Plaque Characteristics at Autopsy

BackgroundPolygenic risk scores (PRS) for coronary artery disease (CAD) potentially improve cardiovascular risk prediction. However, their relationship with histopathologic features of CAD has never been examined systematically. MethodsFrom 4,327 subjects referred to CVPath by the State of Maryland Office Chief Medical Examiner (OCME) for sudden death between 1994 and 2015, 2,455 cases were randomly selected for genotyping. We generated PRS from 291 known CAD risk loci. Detailed histopathologic examination of the coronary arteries was performed in all subjects. The primary study outcome measurements were histopathologic plaque features determining severity of atherosclerosis, including %stenosis, calcification, thin-cap fibroatheromas (TCFA), and thrombotic CAD. ResultsAfter exclusion of cases with insufficient DNA sample quality or with missing data, 954 cases (mean age 48.8{+/-}14.7; 75.7% men) remained in the final study cohort. Subjects in the highest PRS quintile exhibited more severe atherosclerosis compared to subjects in the lowest quintile, with greater %stenosis (80.3%{+/-}27.0% vs. 50.4%{+/-}38.7%; adjusted p<0.001) and a higher frequency of calcification (69.6% vs. 35.8%; adjusted p=0.004) and TCFAs (26.7% vs. 9.5%; adjusted p=0.007). Even after adjustment for traditional CAD risk factors subjects within the highest PRS quintile had higher odds of severe atherosclerosis (i.e., [&ge;]75% stenosis; adjusted OR 3.77; 95%CI 2.10-6.78; p<0.001) and plaque rupture (adjusted OR 4.05; 95%CI 2.26-7.24; p<0.001). Moreover, subjects within the highest quintile had higher odds of CAD-associated cause of death, especially among those aged 50 years and younger (adjusted OR 4.08; 95%CI 2.01-8.30; p<0.001). No associations were observed with plaque erosion. ConclusionsThis is the first autopsy study investigating associations between PRS and atherosclerosis severity at the histopathologic level in subjects with sudden death. Our pathological analysis suggests PRS correlates with plaque burden and features of advanced atherosclerosis and may be useful as a method for CAD risk stratification, especially in younger subjects. HighlightsO_LIIn this autopsy study including 954 subjects within the CVPath Sudden Death Registry, high PRS correlated with plaque burden and atherosclerosis severity. C_LIO_LIThe PRS showed differential associations with plaque rupture and plaque erosion, suggesting different etiologies to these two causes of thrombotic CAD. C_LIO_LIPRS may be useful for risk stratification, particularly in the young. Further examination of individual risk loci and their association with plaque morphology may help understand molecular mechanisms of atherosclerosis, potentially revealing new therapy targets of CAD. C_LI Graphic AbstractA polygenic risk score, generated from 291 known CAD risk loci, was assessed in 954 subjects within the CVPath Sudden Death Registry. Histopathologic examination of the coronary arteries was performed in all subjects. Subjects in the highest PRS quintile exhibited more severe atherosclerosis as compared to subjects in the lowest quintile, with a greater plaque burden, more calcification, and a higher frequency of plaque rupture.

genetics↗

Cell-specific chromatin landscape of human coronary artery resolves regulatory mechanisms of disease risk

Coronary artery disease (CAD) is a complex inflammatory disease involving genetic influences across several cell types. Genome-wide association studies (GWAS) have identified over 170 loci associated with CAD, where the majority of risk variants reside in noncoding DNA sequences impacting cis-regulatory elements (CREs). Here, we applied single-cell ATAC-seq to profile 28,316 cells across coronary artery segments from 41 patients with varying stages of CAD, which revealed 14 distinct cellular clusters. We mapped ~320,000 accessible sites across all cells, identified cell type-specific elements, transcription factors, and prioritized functional CAD risk variants via quantitative trait locus and sequence-based predictive modeling. We identified a number of candidate mechanisms for smooth muscle cell transition states and identified putative binding sites for risk variants. We further employed CRE to gene linkage to nominate disease-associated key driver transcription factors such as PRDM16 and TBX2. This single cell atlas provides a critical step towards interpreting cis-regulatory mechanisms in the vessel wall across the continuum of CAD risk.

genomics↗

Sub-lethal radiation-induced senescence impairs resolution programs and drives cardiovascular inflammation

Radiation is associated with tissue damage and increased risk of atherosclerosis but there are currently no treatments and a very limited mechanistic understanding of how radiation impacts tissue repair mechanisms. We uncovered that radiation significantly delayed temporal resolution programs that was associated with decreased efferocytosis in vivo. Resolvin D1 (RvD1), a known pro-resolving ligand, promoted swift resolution and restored efferocytosis in sub-lethally irradiated mice. Irradiated macrophages exhibited several features of senescence, including increased expression of p16INK4A and p21, heightened levels of SA-{beta}-gal, COX-2, and oxidative stress (OS) in vitro, and when transferred to mice exacerbated inflammation in vivo. Mechanistically, heightened OS in senescent macrophages led to impairment in their ability to carry out efficient efferocytosis and treatment with RvD1 reduced OS and improved efferocytosis. Sub-lethally irradiated Ldlr-/- mice exhibited increased plaque necrosis and p16INK4A cells compared with non-irradiated controls and treatment with RvD1 significantly reduced these endpoints. Removal of p16INK4A hematopoietic cells during advanced atherosclerosis with p16-3MR mice reduced plaque necrosis and increased production of key intraplaque resolving mediators. Our results demonstrate that sub-lethal radiation drives macrophage senescence and efferocytosis defects and suggest that RvD1 may be a new therapeutic strategy to limit radiation-induced tissue damage.

immunology↗

Digital spatial profiling of coronary plaques from persons living with HIV reveals high levels of STING and CD163 in macrophage enriched regions

BackgroundChronic innate and adaptive immune activation may contribute to high prevalence of cardiovascular disease in persons living with HIV (PLWH). MethodsWe assessed coronary plaques from deceased PLWH (n=6) and HIV-negative (n=6) persons matched by age and gender. Formalin-fixed, paraffin-embedded 5m thick sections were processed using Movat, hematoxylin and eosin, immunohistochemical and immunofluorescence stains. Immune cell populations were measured using surface antibodies, and immune-related protein expression from macrophage rich, T-cell rich and perivascular adipose tissue regions using GeoMx(R) digital spatial profiling. ResultsCoronary plaques from PLWH and HIV-negative persons had similar plaque area and percent stenosis. Percent CD163+ cells as measured by immunohistochemical staining was significantly higher in PLWH, median 0.29% (IQR 0.11-0.90) vs. 0.01% (IQR 0.0013-0.11) in HIV-negative plaque, p = 0.02 (Figure 1A). Other surface markers of innate cells (CD68 +, p=0.18), adaptive immune cells (CD3+, p=0.39; CD4+, p=0.09; CD8+, p=0.18) and immune trafficking markers (CX3CR1+, p=0.09) within the coronary plaque trended higher in HIV-positive plaques but did not reach statistical significance. GeoMx(R) digital spatial profiling showed higher differential protein expression of CD163 (scavenger receptor for hemoglobin-haptoglobin complex), stimulator of interferon gamma (STING, a cytosolic DNA sensor), CD25 and granzyme-B in the HIV-positive compared to HIV-negative, p<0.05(Figure 1B). O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=141 SRC="FIGDIR/small/221325v1_fig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@1a4757forg.highwire.dtl.DTLVardef@1e2236org.highwire.dtl.DTLVardef@582f4borg.highwire.dtl.DTLVardef@188f376_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO Characterization of coronary plaques. Representative coronary plaques from three HIV-positive and three HIV-negative individuals were stained with H&E and Movat stain (A). Plaque area (m2) and % plaque stenosis were measured and calculated in 6 individuals per group (B). Statistical analysis, Mann-Whitney; ns not significant C_FIG ConclusionsIncreased inflammation within the coronary plaques of PLWH is characterized by more innate and adaptive immune cells. Higher STING expression in PLWH suggests that immune response to viral antigens within the plaque might be a driver above other stimulants. STING inhibitors are available and could be investigated as a future therapeutic target in PWH if these results are replicated with a larger number of plaques. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=146 SRC="FIGDIR/small/221325v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@27fa00org.highwire.dtl.DTLVardef@8e4a65org.highwire.dtl.DTLVardef@1b65320org.highwire.dtl.DTLVardef@10b7c9a_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIImmunohistochemical and fluorescent stains combined with GeoMx(R) digital spatial profiling allowed for deep characterization of immune cells within intact coronary plaques and perivascular adipose tissue C_LIO_LICoronary plaques from HIV-positive persons had higher proportion of CD163+ immune cells compared to HIV-negative persons C_LIO_LIDifferential protein expression of immune-rich regions of interest within intact 5m sections of coronary plaques revealed higher levels of stimulator of interferon gamma (STING) in HIV-positive persons C_LI

immunology↗