bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 502: Trem2 Regulates Foamy Macrophage Formation In Atherosclerotic Plaque Formation
Authors: Patterson Michael T , Xu Yingzheng , Schrank Patricia , Firulyov Maria , Ronayne Christine , Bishop Courtney , Zhu Alisha , Bold Tyler , Zaitsev Konstantin , Williams Jesse W
Published: November 2022

Atherosclerosis is driven by the accumulation of lipid in artery walls, leading to plaque formation. Plaque expansion is driven by monocyte infiltration where they differentiate into heterogeneous macrophage populations, including foamy macrophages. To understand genes that regulate monocyte differentiation toward foamy macrophages, we performed pseudotime analysis of murine scRNA-seq from atherosclerotic plaques. This analysis identified Trem2, a lipid sensor expressed on myeloid cells, as a potential regulator of foamy cell formation. These results were further supported by an in vitro genome-wide crispr screen performed on oxLDL-treated foamy macrophages, which identified Trem2 as a candidate regulator for oxLDL uptake. To test the role of macrophage Trem2 in atherosclerotic plaque formation, we generated Trem2
fl/fl
CX3CR1
CreER
LDLR
-/-
mice that delete Trem2 only in macrophages upon tamoxifen treatment (TAM). TAM enriched Western Diet (WD) feeding for 8 weeks lead to significantly decreased plaque formation in the aortic arch and aortic sinus of Trem-deficient mice compared to litermate control. Importantly, Trem2flox animals displayed comparable serum cholesterol levels to control mice following WD feeding. Finally, to determine whether Trem2 is required for foamy macrophage formation in vivo, we performed mixed bone marrow chimera of 50% Trem2
-/-
marrow and 50% control marrow into Ldlr
-/-
recipients fed with western diet. Plaque associated Trem2-deficient macrophages failed to develop into foamy macrophages when in competition with WT macrophages, despite normal ratios of circulating monocytes. Overall, this data identifies Trem2 as a novel regulator of foamy macrophage formation and atherosclerotic plaque growth that could be targeted therapeutically to treat CVD.
Abstract 507: Adipocyte-specific Cytokine Signaling Regulates Inflammation And Atherosclerosis
Authors: Mazitova Aleksandra , Peshkova Iuliia , Pozharskaia Vasilisa , Koltsova Ekaterina
Published: November 2022

Adipose tissue inflammation has been implicated in various chronic inflammatory diseases and cancer. Perivascular adipose tissue (PVAT) surrounds the aorta as a fourth layer and was previously shown to regulate the function of endothelial and vascular smooth muscle cells. Moreover, PVAT contains various immune cells and therefore could contribute to the inflammatory environment in the aorta during atherosclerosis development via cross-talk with adventitia. We found that Western diet (WD) feeding increases the accumulation of immune cells in PVAT of atherosclerosis-prone
Ldlr
-/-
mice and increases the expression of IL-1β. As IL-1 is essential for atherosclerosis development and its inhibition in patients in CANTOS trial reduced inflammation and cardiovascular events, we further evaluated the potential role of IL1R signaling in adipocytes of PVAT.We found that adipocyte-specific ablation of IL1R in

Il1r
fl/fl
Ldlr
-/-
AdipoCre
+

mice fed with Western Diet for 16 weeks led to significant reduction in atherosclerosis when compared to

Il1r
fl/fl
Ldlr
-/-
AdipoCre
-

controls. Gene expression analysis of isolated adipocytes revealed a significant reduction of expression of several chemokines, including
Ccl2, Ccl5, Ccl7
as well as pro-atherogenic cytokines
IL-6
and
IL-1β
. The analysis of immune cell composition by Flow cytometry and scRNA sequencing further demonstrated reduced representation of key pro-inflammatory cell subsets in PVAT of

l1r
fl/fl
Ldlr
-/-
AdipoCre
+

which also reflected in their reduced accumulation in the aorta and atherosclerotic plaques. Our data suggest novel adipocyte-specific mechanisms controlling inflammation in atherosclerosis. IL1R signaling therefore directly regulates pro-inflammatory chemokines and cytokines in adipocytes thereby controlling immune cell recruitment to PVAT and aortic wall, which in turn contributes to the enhanced aortic inflammation and atherosclerosis.
Abstract 508: Combined Lipoprotein Lipase And Ldl Receptor Deficiency Increases Atherosclerosis: Hyperchylomicronemia Is Not Benign
Authors: Izquierdo Maria Concepcion , Basu Debapriya , Kanter Jenny E , Gonzalez Ainara , Gjini Jana , Huggins Lesley-Ann , Mullick Adam , Fisher Edward , Bornfeldt Karin E , Goldberg Ira
Published: November 2022

We tested whether accumulation of chylomicrons as an addition to LDL would enhance atherosclerosis. To do this, whole body LpL deficiency was combined with LDL receptor (LDLR) deficiency. Induced global LpL deficiency (i
Lpl
-/-
) was created by tamoxifen injections to activate beta actin-driven cre recombinase in mice. To knock down hepatic LDLR we utilized anti-sense oligonucleotides (ASOs) or a PCSK9 expressing AAV. i
Lpl
-/-
mice on chow diet have elevated plasma TGs, increased VLDL cholesterol, and lower LDL-C compared to control
Lpl
fl/fl
mice. In contrast, when hepatic LDLR was knocked down, the mice displayed elevated LDL-C (~150 mg/dl), similar to the levels seen in control mice with LDLR knockdown. i
Lpl
-/-
mice fed a Western diet for 12 weeks developed severe hypertriglyceridemia (1400-7000 mg/dl) and increased total cholesterol reaching ~1500 mg/dl. LDL-C levels were lower in

iLpL
-/-

mice (160 mg/dl
vs
359 mg/dl) and the increase in cholesterol was primarily in chylomicrons compared to the control mice with LDLR knockdown (1064 mg/dl
vs
238 mg/dl). i
Lpl
-/-
mice had bigger lesions in the brachiocephalic artery (46000 um
2
vs
13000 um
2
) but macrophage content was lower than the control LDLR-deficient mice (24%
vs
69%). Aortic root lesion size was larger (60000 um
2
vs
26000 um
2
), due to a greater the percentage of collagen (34%
vs
23%), but not macrophages (60%
vs
58%) or neutral lipid content (34%
vs
35%). The lack of differences in macrophage accumulation and neutral lipid content and the increase in the collagen content indicates an advanced lesion in the
iLpl
-/-
mice. Thus, our data suggest that intact chylomicrons contribute to atherosclerosis.
Abstract 510: Immune-regulatory Mechanism Of P210-complexed Nanoparticle Immunization For Atherosclerosis
Authors: Zhao Xiaoning , Zhou Jianchang , Chyu Kuang-yuh , Lio Wai Man , Dimayuga Paul C , Cercek Bojan , Trac Noah , Chung Eun Ji , Shah Prediman K
Published: November 2022

Background:
The use of nanoparticles for efficient delivery of therapeutic modalities in humans is rapidly increasing. We have previously reported that a nanovaccine consisting of apoB-100 peptide P210 complexed with amphiphilic micelles (P210-PAM) significantly reduces atherosclerosis in apoE-/- mice. In this study, we defined the mechanistic pathway for the atheroprotective effect of P210-PAM.

Methods and Results:
Seven-week male apoE-/- mice were immunized with P210-PAM or mouse serum albumin peptide amphiphile micelles (MSA-PAM) at a dose of 100ug per injection at 7, 10, and 12 weeks of age. One week after the second booster, mice were euthanized and the splenocytes were collected for immune profiling and immune assays. A second group of immunized mice were injected with thioglycolate to elicit peritoneal macrophages. Splenocytes from P210-PAM mice collected 1 week after the second booster had significantly increased CD4+CD25+FoxP3+ Treg cells and CD8+CTLA-4+ T cells compared to MSA-PAM mice (N=9 each; P≤0.05). Splenocytes from P210-PAM mice had reduced CD4+ T cell proliferation and CD8+CD107a+ T cells in response to P210 recall compared to MSA-PAM (N=8 and 9, respectively; P<0.05). No effects were observed with non-specific PMA/ionomycin stimulation indicating antigen-specificity. Splenic mRNA expression of IL-1β was unchanged but there was significant reduction in IL-1R1, IL-6, and IL-17a in P210-PAM mice (N=12 each; P<0.05). Flow cytometric analysis indicated that the reduced IL-1R1 expression was specific to F4/80+ macrophages (N=10 each; P<0.05). Macrophages enriched from the peritoneal exudate showed significantly reduced iNOS, IL-6, IL-12 and IL-10 mRNA expression in P210-PAM mice compared to MSA-PAM (N=4 each; P<0.05).

Conclusion:
The mechanism of the protective effect of P210-PAM nanoparticles in reducing the immune-inflammatory response in atherosclerosis is at the level of both adaptive T cell response as well as innate macrophage response. The use of P210-PAM in future investigations as potential clinical therapy for atherosclerosis is thus warranted.
Abstract 527: Loss Of Hepatic Insulin Signaling Promotes Apolipoprotein Ai Retention In Liver And Alters HDL In Plasma In Mice
Authors: Vilardo Ava , Anspach Garrett , Li Ailing , Gordon Scott , Graf Gregory A
Published: November 2022

Background:
Insulin signaling regulates a variety of features of hepatic lipid and lipoprotein metabolism. Liver-specific deletion of insulin receptor (LIRKO) reduces plasma HDL, an effect attributed to a reduction in deiodinase 2 expression and apolipoprotein (Apo) AI mRNA expression. We report a concomitant accumulation of ApoAI protein in the liver of LIRKO mice in a yet to be fully characterized compartment within hepatocytes.

Methods:
Mice harboring loxP sites within the insulin receptor gene (IR
fl/fl
) were administered a control adenoassociated viral vector (AAV-Empty) or an AAV encoding Cre recombinase under the control of a liver-specific promoter (AAV_TBG-Cre) at 8 weeks of age to generate Control and LIRKO mice. Male and female mice were evaluated for the abundance of ApoAI in liver and total and FPLC-fractionated plasma. ApoAI secretion rates were evaluated in primary hepatocytes from both genotypes. Subcellular localization of ApoAI in liver of Control and LIRKO mice was evaluated by immunofluorescence microscopy and biochemical fractionation.

Results:
The loss of hepatic insulin receptor and signaling was confirmed by rtPCR, immunoblot analysis and glucose tolerance test. Whereas ApoAI was unaffected in LIRKO mice compared to controls, protein levels were reduced in plasma and elevated in liver. In contrast, no changes were observed for ApoB or ApoE in either liver or plasma. FPLC fractionation of plasma indicates a shift in HDL size and an accumulation of ApoM in the HDL fractions. Secretion rates of newly synthesized ApoAI were modestly reduced in primary hepatocytes isolated from LIRKO mice. Immunolocalization of ApoAI demonstrated accumulation in large, membrane-bound organelles located peripherally in cells. These organelles stained positively for LampI and other markers of the endosomal-lysosomal system. However, markers of the endosomal-lysosomal compartment in perinuclear regions of the cells were negative for ApoAI.

Conclusions:
Insulin signaling is a regulator of ApoAI secretion that alters the intracellular itinerary of ApoAI in the secretory and endocytic pathways and alters the plasma HDL proteome in mice.
Abstract 529: The Intra-molecular Pathway Of Nck1 In Atherogenic Endothelial Activation
Authors: Alfaidi Mabruka , Reddick Milla , Shen Xinggui , Orr A. Wayne
Published: November 2022

Rational:
Atherosclerosis, a chronic progressive disease, is the underlying disease process in ischemic heart disease (IHD). Despite our advances, IHD is still the leading cause of disease mortality worldwide. Endothelial Activation due to disturbed blood flow (d-flow) is one of the earliest changes in atherosclerosis. However, the molecular pathway whereby d-flow induces endothelial activation is unclear.

Methodology & Results:
Herein we identified the signaling protein Nck1 as a key regulator to atherogenic endothelial activation. Nck1 is an adaptor molecule with a multi-domain structure, and in response to d-flow, we found that the Nck1 SH2 (phosophotyrosine binder) and the Nck1 SH3.1 (with a high affinity to bind to proline rich peptides) are critical domains of Nck1 to regulate the prolinflammatory signal activation. In addition, the small molecule inhibitor, AX-024 (50 nM), which occupies the DY pocket of the Nck1 SH3.1, prevents d-flow induced endothelial activation, suggesting downstream mediator that binds to the Nck1 SH3.1 and mediates the activation. In order to determine the Nck1 specific signaling partners, we used affinity purification-mass spectrometry and we identified 6 signaling proteins that significantly interact with Nck1 in response to d-flow. In vivo, our endothelial-specific Nck1 knock out mice show significantly less atherosclerosis lesion burden compared to their littermate controls.

Conclusions:
A recent GWAS analysis linked Nck1 to IHD, underscoring its importance as a potential therapeutic target. AX-024 is a first-in-class a small molecule inhibitor to Nck1, and is currently being tested in clinical trials. Our data confirms a role for AX-024 in preventing endothelial activation after d-flow exposure and sheds light on a previously uncharacterized function of Nck1 adaptor protein in atherogenic endothelial activation.
Abstract 532: Dioxin Modifies The Transcriptomic And Epigenetic Landscape Of Smooth Muscle Cells Leading To Adverse Remodeling Of Atherosclerosis
Authors: Qin Guyu , Easwaran Meena , Damiani Isabella , Zhao Quanyi , Kundu Ramendra K , Nguyen Trieu , Cheng Paul , Quertermous Thomas , Kim Juyong B
Published: November 2022

Background:
Environmental exposure to dioxin, an active component of cigarette smoke and air pollution has been linked to increased myocardial infarction. Smooth muscle cells (SMC) in the coronary vasculature play a critical role in atherosclerotic plaque remodeling due to their phenotypic plasticity. We have previously found strong dioxin response element activity in modulated SMC of atherosclerotic lesion. In this study, we aimed to understand the effect of dioxin on vascular SMC and atherosclerosis phenotype.

Methods:
Primary human coronary artery SMC (HCASMC) treated in culture with 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) or vehicle control were used to perform RNA-Seq and ATAC-Seq. ChIP-Seq was performed with antibodies against Aryl-hydrocarbon receptor (AHR) and TCF21. Tamoxifen inducible SMC-lineage tracing reporter mice were used to assess the in-vivo effect of TCDD on aortic SMC. After 8 weeks of high fat diet (HFD), followed by 8 weeks of TCDD injection and HFD, the aortic sinus was collected for histology and single-cell sequencing (10X Genomics).

Results:
Analysis of the RNA-Seq from TCDD treated HCASMC showed differential enrichment of pathways related to cell migration and vascular development. Further, ATAC-Seq data showed a significant enrichment for pathways regulating vascular development, cell migration, and apoptosis. There was an overall increase in chromatin accessibility suggesting transcriptional activation with TCDD. We observed enrichment for AHR ChIP-Seq peaks in the open chromatin regions along with a significant reciprocal reduction in TCF21 occupancy. The scRNA-Seq of mice treated with TCDD exposure showed differential gene expression of SMC-lineage cells enriching for extracellular matrix (ECM) organization, inflammation, unfolded protein response, and apoptotic process, and histological analysis of the aortic sinus showed increased lesion area with increased presence of SMC-lineage cells and
Cd68
+ cells compared to control.

Conclusion:
Dioxin adversely remodels atherosclerotic plaque affecting pathways of ECM organization, inflammation and unfolded protein response in SMC, partly by modifying chromatin accessibility and occupancy of key transcription factors of phenotypic modulation.
Abstract 544: Single-Cell RNA Sequencing Suggests Roles For Cell-Matrix Interactions And Inflammation In The Pathogenesis Of Aortopathy In Loeys-Dietz Syndrome
Authors: Sanford Nicole , liu li , Cheng Paul , Quertermous Thomas , Dichek David
Published: November 2022

Background:
Humans with Loeys-Dietz syndrome (LDS; caused by heterozygous loss-of-function mutations in
TGFBR2
or other TGF-β signaling molecules) develop proximal aortic aneurysms and dissections. The mechanisms through which heterozygosity for these mutations causes aortic disease are poorly understood. Roles for decreased and increased TGF-β signaling in SMC have been suggested.

Methods:
To investigate the pathogenesis of aortopathy caused by heterozygosity for a
TGFBR2
loss-of-function variant found in humans with LDS, we used mice with an orthologous variant (
Tgfbr2
G357W/+
). We performed single-cell RNA sequencing with pathway analysis on proximal aortas of 17-20-wk-old mice and histology on aortic roots of 30–50-wk-old mice.

Results:
ScRNA-seq showed either mildly decreased (less than 50%) or equivalent expression of TGF-β signaling targets (
Serpine1, Ctgf, Col1a1, Col1a2
) in proximal aortic SMC of
Tgfbr2
G357W/+
mice vs WT littermate controls. Moreover,
Tgfbr2
G357W/+
SMC had no significant changes in expression of transcripts encoding any of the three TGF-β ligands. Pathway analysis of SMC transcriptomes showed upregulation of genes involved in focal adhesion and extracellular matrix (ECM) interactions (FDR<0.05 for both) in
Tgfbr2
G357W/+
mice. ScRNA-seq also identified a unique cluster of fibroblast-like cells present only in
Tgfbr2
G357W/+
aortas. These cells had increased expression of genes related to immune activation and macrophage recruitment
(Saa3, Ccl2, Cxcl12
; ~2-fold change and p<0.001 for all) and increased mRNA encoding
Mmp3
(>3-fold change, p<0.001). The percentage of immune cells identified by scRNA-seq was ~3-fold higher in
Tgfbr2
G357W/+
versus WT proximal aortas (p=0.03). These immune cells included macrophages that express
Ccr2
and
Cxcr4
(receptors for CCL2 and CXCL12). Aortic root sections of older
Tgfbr2
G357W/+
mice had significant adventitial inflammation.

Conclusions:
We found evidence for decreased—but not increased—TGF-β signaling in proximal aortas of
Tgfbr2
G357W/+
mice. Emergence of a proinflammatory and potentially destructive fibroblast-like cell type and infiltration of inflammatory cells may play roles in aortopathy caused by a heterozygous loss-of-function variant of
Tgfbr2
.
Abstract 546: Investigation Of The Role Of LRP1 Patient Mutations On Abdominal Aortic Aneurysms
Authors: Wani Mashhood , Au Dianaly T , Migliorini Mary , Hampton Brian , Strickland Dudley
Published: November 2022

LRP1 (low density lipoprotein receptor-related protein 1) is a large endocytic receptor that binds over 100 structurally unrelated ligands. Our lab has demonstrated that a sm22 promoter-driven, smooth muscle specific knock-out of LRP1 (smLRP1-/-) results in aortic aneurysms in mice due to fragmentation and degradation of the elastic fibers, further implicating LRP1 in vascular development. Furthermore, the identification of a patient with abdominal aortic aneurysm (AAA) harboring missense mutations in LRP1 has allowed for investigations into the role of LRP1 in aneurysm formation. Utilizing a combination of biochemical and proteomic techniques, we sought to understand the role of these mutations in cellular function. By means of a receptor-ligand binding assay, we quantified the internalization and degradation of
125
I-activated alpha-2-macroglobulin (a2M*) in LRP1-deficient cells transfected with mutant LRP1 and aortic smooth muscle cells isolated from a patient with an abdominal aortic aneurysm and LRP1 missense mutations. The results showed defects in LRP1-mediated internalization of a
2
M* in LRP1 variants when compared to wild type LRP1. Furthermore, through extensive proteomic analysis of primary patient cells harboring these mutations, multiple dysregulated pathways of interest have been identified along with elevated levels of MMP-1 in the cultured media. In total, our data highlights the biochemical deficits in different variants of LRP1 that may contribute to the pathogenesis of AAA. Pinpointing the role of LRP1 in aneurysm mechanisms will allow for non-invasive interventions to be employed before aortic rupture.
Abstract 548: Prolonging The Viability Of Induced Pluripotent Stem Cell-derived Endothelial Cells For Treatment Of Peripheral Arterial Disease Using Engineered Biomaterials
Authors: Yang Guang , Alcazar Cynthia , Hu Caroline , Zaitseva Tatiana , Paukshto Michael , Huang Ngan F
Published: November 2022

Dysfunctional endothelial cells (EC) can restrict flow in the extremities, leading to limb ischemia. We aim to improving revascularization of ischemic limbs using cell therapy, augmented with spatially patterned scaffolds that promote survival. The purpose was to evaluate the effect spatially patterned scaffolds on endothelial cell survival. The biophysical parameters of collagen scaffolds (alignment, crosslinking, and fibril diameter) were characterized with atomic force microscopy and degradation assays. Cytoskeletal arrangement of primary human coronary artery ECs and human induced pluripotent stem cell (iPSC)-derived ECs on collagen scaffolds was evaluated by F-actin staining. To evaluate the effect of mechanical properties on cell viability
in vitro,
Live/Dead and MTS assays were used. Cell seeded scaffolds were implanted into a mouse hindlimb ischemia model, and cell survival was tracked by bioluminescent imaging. Both primary EC and iPSC-ECs reorganized their F-actin cytoskeleton corresponding to the alignment of the fibrils, irrespective of crosslinking degree, stiffness or fibril diameter. When cells were grown in hypoxic mimicking ischemia however, viability was improved using aligned scaffolds with 200 nm fibril diameter. Degradation assays showed that scaffolds with higher crosslinking had significantly more durability. When cell-seeded scaffolds were implanted to the ischemic limb, the aligned scaffolds with 200nm fibril diameter had the highest survival, confirming
in vitro
studies. Aligned collagen scaffolds with 200nm fibril diameter and high cross-linking degree led to improved viability of primary and iPSC-ECs in a mouse model of PAD.
Abstract 552: Sustained Inhibition Of High Mobility Box 1 By Antisense Oligonucleotide
Authors: Mohammadmoradi Shayan , Sawada Hisashi , Ito Sohei , Mullick Adam , Howatt Deborah , Franklin Micheal , Lu Hong , Daugherty Alan
Published: November 2022

Background:
High-mobility group box 1 (HMGB1), a highly conserved nonhistone DNA-binding nuclear protein, may contribute to vascular diseases including atherosclerosis, pulmonary hypertension, and abdominal aortic aneurysm. Since whole-body genetic deletion of HMGB1 is embryonic lethal, pharmacological approaches, such as neutralizing antibodies and functional inhibitors, have been used to manipulate HMGB1 in mice. However, it remains desirable to genetically manipulate HMGB1 for further understanding its role. In the current study, we assessed the efficacy of a novel antisense oligonucleotides (ASOs) approach to deplete HMGB1 in mice.

Methods and Results:
First, abundance of HMGB1 mRNA was assessed by qPCR in major organs and tissues of male C57BL/6J mice (N=6).
Hmgb1
mRNA was expressed ubiquitously, but it was most highly abundant in the lung, while least abundant in the testes. Next, we examined the efficacy of ASOs to reduce HMGB1 protein abundance at selected intervals. Either ASOs (25 mg/kg/day) or phosphate-buffered saline (PBS) were injected intraperitoneally into male C57BL/6J mice (8-10-week-old) at day 0 and 3 in the initial week and then once a week during the remainder of the study. Mice were terminated at either 2, 6, or 12 weeks after the initial injection of ASOs (N=5/group). Subsequently, mRNA and protein abundance of HMGB1 were determined in the lungs. Since previous studies have shown that systemic administration of ASOs mainly targets kidney and liver, HMGB1 mRNA or protein abundance was also examined in these organs. We also assessed HMGB1 protein abundance in the heart. In lungs, kidney, and liver, ASO administration resulted in a consistent >90% decrease of
Hmgb1
mRNA abundance at 2 weeks of ASO injection (P>0.001). The decreased
Hmbg1
mRNA abundance was also consistent at both weeks 6 and 12 (P>0.001). ASOs decreased HMGB1 protein abundance significantly at 6- and 12-week time intervals. Heart tissue also indicated a consistent
Hmgb1
mRNA decrease in response to ASO administration.

Conclusion:
ASO approach decreased HMGB1 at mRNA and protein abundance for 12 weeks in the liver, kidney, lungs, and heart. This mode may provide more clear insights into understanding the biological functions of HMGB1.
Abstract 560: Fludrocortisone Induces Aortic Pathologies In Mice
Authors: Liang Ching L , Ye Dien , Wu Congqing , Howatt Debroah , Daugherty Alan , Lu Hong
Published: November 2022

Objective:
Fludrocortisone, a corticosteroid, is used to treat adrenocortical insufficiency. In a previous study to determine associations between fludrocortisone-induced high blood pressure and angiotensin regulation, we observed aortic aneurysms in some fludrocortisone-infused mice. The purpose of this study was to investigate fludrocortisone-induced aortic pathologies in normocholesterolemic and hypercholesterolemic mice.

Methods and Results:
To determine whether fludrocortisone induces aortic aneurysms in normocholesterolemic mice, male C57BL/6J at 8 - 9 weeks of age were infused with either vehicle (85% polyethylene glycol 400 (PEG-400) and 15% dimethyl sulfoxide (DMSO); N=5) or fludrocortisone (12 mg/kg/day dissolved in 85% PEG-400 and 15% DMSO; N=15) for 28 days. Fludrocortisone-infused mice had higher systolic blood pressure, compare to mice infused with vehicle. Fludrocortisone induced aortic pathologies in 4 of 15 mice with 3 having pathologies in the ascending/arch region and 1 having pathology in both the ascending and descending thoracic aorta. No pathologies were noted in abdominal aortas. To determine whether hypercholesterolemia augments fludrocortisone-induced aortic pathologies, we infused either vehicle (N=5/group) or fludrocortisone (N=15/group) into male ApoE -/- mice fed a normal diet or LDL receptor -/- mice fed either normal or Western diet. Fludrocortisone increased systolic blood pressure, irrespective of mouse strain or diet. In ApoE -/- mice infused with fludrocortisone, 2 of 15 had ascending aortic pathologies, but no mice had abdominal aortic pathologies. In LDL receptor -/- mice fed normal diet, 4 had ascending/arch aortic pathologies, 1 had pathologies in the ascending, arch and abdominal regions. In LDL receptor -/- mice fed Western diet, 2 died of aortic rupture, 4 had ascending/arch aortic pathologies, and 1 had pathologies in the ascending, arch and suprarenal aortic regions. Aortic pathologies were hemorrhage, wall thickening or thinning, or dilation. Given the low incidence, no quantification of aortic pathologies reached statistical significance.

Conclusion:
Fludrocortisone induces aortic pathologies with low incidence in both normo- and hypercholesterolemic mice.
Abstract 561: Micro-CT Visualizes Extensive Vascular Pathologies In Smooth Muscle Cell-specific LRP1 Deficient Mice
Authors: Franklin Michael , Howatt Debroah , Moorleghen Jessica J , Sawada Hisashi , Lu Hong , Daugherty Alan
Published: November 2022

Objective:
Low-density lipoprotein receptor-related protein 1 (LRP1) is a multifunctional protein that is abundant in vascular smooth muscle cells (SMCs). SMC-specific deletion of LRP1 leads to vascular pathologies in the aorta and superior mesenteric artery (SMA) of mice. Although other vascular beds have not been explored. Micro-computed tomography (CT) enables scanning in a high spatial resolution (~20 μm). To determine the regional effects of SMC-specific LRP1 deficiency in mice, we performed detailed morphometric analyses of vascular pathologies using micro-CT.

Approach and Results:
Male and female wild-type and SMC-specific LRP1 deficient mice were monitored for aortic and SMA dilatations from 6 weeks through 40 weeks of age using ultrasonography. Progressive luminal dilatations of the ascending aorta were detected in both male and female SMC-specific LRP1 deficient mice, compared to their wild type littermates. Ultrasound was only able to detect the superior mesenteric artery within ~2 mm of the branch from the abdominal aorta. Therefore, ultrasonography is not optimal for monitoring the SMA. At the age of 40 weeks, mice were euthanized, perfused with saline and injected with Microfil silicone rubber through the left ventricle. Subsequently, each mouse was scanned by a Bruker SkyScan 1276 high-resolution desktop micro-CT and 3 dimensional images were generated. Aortic CT images showed profound dilatations of the entire aorta and its main branches, with more pronounced changes in the ascending thoracic and infrarenal aortic regions. Micro-CT also detected longer and tortuous aortic structure, compared to their wild type littermates. The most striking pathologies, including both dilation and tortuosity, were observed in the SMA and its branches with more depth and detailed insights, compared to ultrasonography.

Conclusions:
The ability to visualize the entire vasculature of mice using micro-CT technology demonstrated that SMC-specific deficiency of LRP1 has marked heterogeneity in development of vascular pathologies.
Praliciguat Promotes Ischemic Leg Reperfusion in Leptin Receptor-Deficient Mice
Authors: Foussard Ninon , Rouault Paul , Cornuault Lauriane , Reynaud Annabel , Buys Emmanuel S. , Chapouly Candice , Gadeau Alain-Pierre , Couffinhal Thierry , Mohammedi Kamel , Renault Marie-Ange
Published: November 2022

Background:

Lower-limb peripheral artery disease is one of the major complications of diabetes. Peripheral artery disease is associated with poor limb and cardiovascular prognoses, along with a dramatic decrease in life expectancy. Despite major medical advances in the treatment of diabetes, a substantial therapeutic gap remains in the peripheral artery disease population. Praliciguat is an orally available sGC (soluble guanylate cyclase) stimulator that has been reported both preclinically and in early stage clinical trials to have favorable effects in metabolic and hemodynamic outcomes, suggesting that it may have a potential beneficial effect in peripheral artery disease.

Methods:

We evaluated the effect of praliciguat on hind limb ischemia recovery in a mouse model of type 2 diabetes. Hind limb ischemia was induced in leptin receptor-deficient (Lepr

db/db

) mice by ligation and excision of the left femoral artery. Praliciguat (10 mg/kg/day) was administered in the diet starting 3 days before surgery.

Results:

Twenty-eight days after surgery, ischemic foot perfusion and function parameters were better in praliciguat-treated mice than in vehicle controls. Improved ischemic foot perfusion was not associated with either improved traditional cardiovascular risk factors (ie, weight, glycemia) or increased angiogenesis. However, treatment with praliciguat significantly increased arteriole diameter, decreased ICAM1 (intercellular adhesion molecule 1) expression, and prevented the accumulation of oxidative proangiogenic and proinflammatory muscle fibers. While investigating the mechanism underlying the beneficial effects of praliciguat therapy, we found that praliciguat significantly downregulated
Myh2
and
Cxcl12
mRNA expression in cultured myoblasts and that conditioned medium form praliciguat-treated myoblast decreased
ICAM1
mRNA expression in endothelial cells. These results suggest that praliciguat therapy may decrease
ICAM1
expression in endothelial cells by downregulating
Cxcl12
in myocytes.

Conclusions:

Our results demonstrated that praliciguat promotes blood flow recovery in the ischemic muscle of mice with type 2 diabetes, at least in part by increasing arteriole diameter and by downregulating ICAM1 expression.
How long do laelapid mites (Acari: Mesostigmata: Laelapidae) live?
Authors: ZHANG NA , LIU XIAOYING , LU WENZHI , TAN YANYING , XIE LIXIA , YAN YI
Published: November 2022

The family Laelapidae includes over 1500 morphologically and behaviorally diverse species that are free-living predatory mites or associated with mammals, birds, and arthropods. So far, however, only 29 species of laelapid mites have been studied for their lifespan or developmental period of immature stages. In this review, we provide a survey of the lifespan and immature stage developmental period of Laelapidae. This review summarized previously published data on the developmental time from egg to adult under different conditions, primarily diet, temperature, and relative humidity, and between sex, when the data is available. The longest-lived can survive more than 500 days, while the short-lived is only in stock for 2 days. All these biotic and abiotic factors affect lifespan and immature developmental period of laelapid mites.
The role of acid phosphatase during sucking blood of Haemaphysalis longicornis
Authors: WANG KUANG , GAO ZHIHUA , ZHANG SONGBO , SHI YANQING , DONG KEXIN , LV WENXIA , YANG XIAOLONG
Published: November 2022

In this study, a novel acid phosphatase was isolated from Haemaphysalis longicornis which may affect the reproductive development of the tick. The gene was isolated from a cDNA library named HLACP and analyzed by bioinformatics. Then, the spatial and temporal expression patterns of the genes were analyzed by real-time PCR.  In addition, combined with RNAi interference platform and protein modification omics, the changes of protein expression and modification level of H. longicornis before and after blood feeding were analyzed after interference with HLACP.
Anatomy of a border: transition between Southwestern Atlantic tropical and Warm Temperate marine provinces as revealed by marine mites
Authors: PEPATO ALMIR R. , VIDIGAL TEOFÂNIA H. D. A. , KLIMOV PAVEL B.
Published: November 2022

A previous study found that the division between the Southwestern Atlantic Tropical and Warm Temperate Provinces for marine mites do not occur in Cabo Frio (~23°S), as usually assumed in marine biogeographical studies, but somewhere around the Abrolhos Plateau and the Vitória-Trindade Chain (~20-15°S). New sampling localities along this section of Brazilian coast and sequences from mitochondrial and nuclear genes of three species or species complexes of halacarids (Agauopsis legionium, A. bilophus and Rhombognathus levigatoides) deepened the understanding of this region by showing different scenarios for the different species.
The role of salivary proteins from Tetranychus evansi in the mite-plant interaction
Authors: CUI JIA-RONG , BING XIAO-LI , HONG XIAO-YUE
Published: November 2022

Herbivores and plants have been engaged in a tight co-evolutionary arms race, and saliva played important roles in this process. Some herbivore-derived small molecules or proteins called herbivore-associated molecular patterns (HAMPs) can be recognized by plants and thus trigger plant immune responses. Another type of salivary proteins, called effectors, utilize various strategies to suppress plant defense responses to establish successful feeding. The tomato red spider mite Tetranychus evansi is a worldwide pest of Solanaceous crops and causes enormous economic damage in many regions of the world. During the feeding process, T. evansi secretes saliva into plant cells through cheliceral stylets. Secreted saliva plays crucial roles in modulating plant-mite interaction, such as effectors Te28 and Te84 (Villarroel et al., 2016). We previously identified 136 salivary proteins from T. evansi by transcriptome and LC-MS/MS analyses (Huang et al., 2018). However, the role of these salivary proteins in mite-plant interaction was unknown. Here, we identified a salivary protein involved in the mite-plant interaction (Cui et al., 2022). This protein encodes a protein disulfide isomerase (TePDI) and acts as a HAMP that triggers plant defenses by inducing ROS burst, callose deposition and plant defense-related genes in Nicotiana benthamiana. TePDI can be recognized by multiple Solanaceae plants such as tomato, pepper, and eggplant. TePDI-mediated cell death in N. benthamiana is dependent on the plant signaling molecules SGT1 (suppressor of the G2 allele of skp1) and HSP90 (heat shock protein 90). To better feed on plants, T. evansi inhibited TePDI-triggered cell death and plant defense responses by secreting effectors Te28 and Te84. Further analysis revealed that PDI from phylogenetically distinct herbivorous and non-herbivorous arthropods all triggered cell death and immune response in N. benthamiana. Moreover, silencing PDI gene in spider mites and whiteflies resulted in the reduced survival rate of both pests. Altogether, our study revealed that PDI is a double-edged sword. On the one hand, it is functionally conserved in herbivores and required for their survival; on the other hand, it is recognized by Solanaceae plants and enhances plant resistance against herbivores. Our findings indicate that plants utilize evolutionarily conserved HAMPs to activate plant defense and resist pest damage, providing a potential strategy for pest management.
Roles of salivary proteins in bacteria-mediated reproductive manipulation in spider mites
Authors: BING XIAO-LI
Published: November 2022

Arthropods host a diverse range of microbes. Some symbiotic bacteria are important in influencing the performance of arthropods, especially when facing biotic and abiotic challenges. The symbiont Wolbachia is a genus of intracellular bacteria (Rickettsiaceae) found in about 40% of terrestrial arthropods. It causes a variety of reproductive alterations in arthropod hosts, such as inducing parthenogenesis, killing males, feminizing genetic males, and inducing cytoplasmic incompatibility (CI), and is well known as a reproductive manipulator in arthropods. Recent studies show that Wolbachia can also affect host fitness by mediating interactions between plant and herbivores. But it remains unclear whether saliva proteins are involved in this process. The two-spotted spider mite (Tetranychus urticae), a notorious cosmopolitan agricultural pest, harbors Wolbachia (Xie et al., 2006). In this study, we explored the effects of Wolbachia on biological performance of T. urticae (Bing et al., 2022). We showed that the Wolbachia-infected T. urticae decreased the number of deposited eggs but increased the egg hatching rate compared with Wolbachia-uninfected mites. With transcriptomic analysis data, we further demonstrated that Wolbachia infection upregulated the gene expression levels of many T. urticae salivary proteins, which include a cluster of Tetranychidae-specific, functionally uncharacterized SHOT1s (secreted host-responsive proteins of Tetranychidae). These SHOT1 genes were highly enriched in the proterosomas (Jonckheere et al., 2018) and were expressed more in the feeding stages (nymphs and adults) of mites than in eggs. RNAi experiments showed that knocking down SHOT1s could significantly decrease Wolbachia titer, increase the number of deposited eggs and decrease the egg hatching rate. Altogether, our results suggest that host salivary proteins are related to Wolbachia-mediated manipulations of host reproduction.
Regulation of three subtypes of SOD gene in Aleuroglyphus ovatus (Acari: Acaridae) under lead stress
Authors: AI HUI , ZHU PEIPEI , XIONG WENHUI , XIA BIN , ZOU ZHIWEN
Published: November 2022

Superoxide dismutase (SOD) is an important enzyme that acts as the first line of protection in the mite antioxidant defense system and involves in eliminating reactive oxygen species (ROS) under harsh environmental conditions. Lead pollution is becoming increasingly serious and poses a serious hazard to the health and survival and reproduction of organisms. Nevertheless, the SOD gene family was yet to be reported in stored grain pest mite (Aleuroglyphus ovatus). In the present study, A. ovatus was reared on artificial diets treated with different concentrations of lead (12.5, 25, 50 and 100 mg/kg); the treatment fed on artificial diet without lead was marked as the control group (CK). Then three different subtypes of SOD were cloned, including AoSOD1 (Cu-ZnSOD), AoSOD2 and AoSOD3 (MnSOD). Enzyme activity of the egg stage was the lowest, and that of the protonymph stage was the highest. The enzyme activity of A. ovatus increased initially before dropping with increasing lead concentration, nevertheless, it was still substantially higher than that in CK. The analysis of SOD enzyme activity specified that it was higher at 25 mg/kg lead in each mite stage compared to other concentration groups. All three genes were up-regulated and thereafter reduced in the embryonic stage, according to an examination of mRNA expression levels; tritonymphs, in particular, attained the highest level. The expression level of the SOD genes also changed with lead concentration. It increased after an initial decline trend with increasing lead concentration, and then peaked in the 100 mg/kg lead group, which were 3.1 times (AoSOD1), 4.1 times (AoSOD2), and 2.3 times (AoSOD3) the control group, respectively. In this study, three AoSOD genes had developmental stage-specific mRNA expressions, and the expression of SOD enzyme activity was encouraged by the higher lead concentration, and the mRNA expression level of the AoSODs genes was not synchronized with the enzyme activity.
Monitoring mites in orchards: absence or non-detection?
Authors: RAHMANI HASAN , LEFOE GREG , KWONG RAELENE
Published: November 2022

Successful integrated pest management (IPM) programs rely on effective and efficient methods of monitoring pest and beneficial species, including mites. Several methods have been proposed for monitoring mites in Australian orchards, mainly based on examining leaves in situ. During the 2021–2022 growing season we flagged 1–2 pear trees Pyrus communis in each of 192 panels (a panel being trees in a 14 m length of a row) in a pear orchard at Tatura, Victoria, Australia. For each flagged tree we examined mite species occurrence and prevalence using three methods, (1) non-destructive visual examination of 10 leaves per panel using a 10x hand lens (current industry standard), (2) destructive lab-based examination of 4 leaves per flagged tree(s) using a stereo microscope, and (3) destructive lab-based examination of 2 leaves per flagged tree(s) using a stereo microscope. The presence and prevalence of pest mites and the previously released predatory mite Neoseiulus californicus were recorded. Throughout the season we observed various pest mites in the orchard including Tetranychus urticae, Panonychus ulmi, Eriophyes pyri, and Bryobia rubrioculus and the predatory mite N. californicus. However, the number of species detected and the prevalence of detected species on leaves were dependant on sampling method used. Both destructive sampling methods, method (2) and method (3), performed better than the current non-destructive industry standard in terms of species detection and prevalence. The largest differences were seen during the early stages of infestation for mite species other than E. pyri. Early detection of certain mite species is important because it can provide a more accurate estimate of the starting point for Cumulative Leaf Infested Days (CLIDs) calculations, resulting in better informed management decisions. Importantly, detection and prevalence results were similar for methods (2) and (3) despite the greatly reduced sampling effort (time required) for method (3), and overall sampling effort for method (3) was similar to that required for method (1). Therefore, in terms of both accuracy and sampling effort, method (3) outperformed the other two methods we trialled. An obvious limitation of method (3) when compared to current practice is the requirement for a stereo microscope and access to a laboratory or similar facility. Therefore, the method may be more useful for appropriately trained consultants who monitor pests in orchards on behalf of growers. Another limitation with our study was that it was limited to a single growing season in one pear orchard. We therefore recommend further research to validate our observations, and to support recommendations for growers and consultants.
Effects of inbreeding on development, growth, reproduction and survival in a predatory mite Stratiolaelaps scimitus
Authors: XIE LIXIA , ZHANG NA , ZHANG XU , WANG LI , YAN YI
Published: November 2022

Stratiolaelaps scimitus living in microhabitats (e.g., soil, humus and litter), is an important predatory mite (Zhang et al., 2022) used in biological control of pests, such as the thrips pupae (Satio and Brownbridge, 2016; Mouden et al., 2017), fungus gnat larvae (Castilho et al., 2009; Wen et al., 2017; Zhou et al., 2018) and snout moth eggs (Xie et al., 2018). It has been commercially produced (Knapp et al., 2018). However, commercial production of predatory mites inducing inbreeding is inevitable, which may lead to inbreeding inhibition and lower fitness of offspring (Slate et al., 2000), for example, the decline of vitality, fecundity, stress resistance, adaptability and retardation of growth.
Harassment-experienced Tetranychus kanzawai females skillfully refuse male courtships
Authors: WADA TOMOMI , YANO SHUICHI
Published: November 2022

Because persistent male courtships and multiple mating (i.e. male mating harassment) generally impose fitness costs to females (Köhler et al. 2011), females are considered to have developed adaptive strategies to avoid such troubles (Breed et al. 2015). Although only the first mating is effective for females in the Kanzawa spider mite Tetranychus kanzawai, males frequently court already mated females. To examine the effects of previously experienced male mating harassment on mating avoidance by T. kanzawai females, we experimentally compared mating avoidance behaviors of mated females that had cohabited with three adult males for three days (harassment+) and mated females that had been isolated for the same period after the first mating (harassment-). We found that significantly more harassment+ T. kanzawai females refused male courtships compared to harassment- females, suggesting that T. kanzawai females that had experienced male mating harassment learned at least in part how to refuse male courtships. The mechanism by which harassment-experienced T. kanzawai females refuse male courtships will be discussed.
First detection of numerical variations in aggenital setae of female Eustigmaeus segnis (Koch) (Acariformes: Stigmaeidae)
Authors: DOĞAN SALİH , FAN QING-HAI , UĞURLU ŞİFANUR , ERMAN ORHAN
Published: November 2022

Eustigmaeus segnis (Koch, 1836) (Stigmaeidae) (Fig. 1) has a widespread distribution and was recorded from many countries including Turkey (Fan et al. 2016; Doğan et al. 2018a; Doğan 2019). This species can be recognized by having dorsal dimples in uniform size, dorsal body setae long, falciform with marginal spinules, dorsal setae c1 widely spaced in both sexes, metasternal shield fused with (Fig. 2A) or partly separated from endopodal shields (Fig. 2B) in female and a pair of aggenital setae in both sexes (Doğan 2005; Bayrak et al. 2019).