scholarly journals Bone Marrow Ts65Dn Trisomy-Induced Changes in Platelet Functionality and Lymphocytopenia Do Not Impact Atherosclerosis Susceptibility in Mice

2021 ◽  
Vol 8 (9) ◽  
pp. 110
Author(s):  
Suzanne J. A. Korporaal ◽  
Ronald J. van der Sluis ◽  
Miranda Van Eck ◽  
Menno Hoekstra

The genetic disorder Down syndrome is associated with a decreased susceptibility for atherosclerotic cardiovascular disease. Hematological and immune abnormalities occur frequently in Down syndrome patients. We evaluated, in a preclinical setting, the impact of a Down syndrome-like hematological / immune phenotype on atherosclerosis susceptibility. Hereto, hypercholesterolemic low-density lipoprotein receptor knockout mice were transplanted with bone marrow from either a trisomic Ts65Dn mouse or euploid wild-type control and subsequently fed a Western-type diet to induce the development of atherosclerotic lesions. T and B cell concentrations were markedly reduced in blood of Ts65Dn bone marrow recipients (p < 0.001). Expression levels of the pro-atherogenic scavenger receptor CD36 were respectively 37% and 59% lower (p < 0.001) in trisomic monocytes and macrophages. However, these combined effects did not translate into an altered atherosclerosis susceptibility. Notably, blood platelet numbers were elevated in Ts65Dn bone marrow recipients (+57%; p < 0.001), which was paralleled by higher platelet GPVI protein expression (+35%; p < 0.001) and an enhanced collagen-induced platelet activation (p < 0.001). In conclusion, we have shown that providing mice with a Down syndrome-like hematological profile does not change the susceptibility to atherosclerosis. Furthermore, our studies have uncovered a novel effect of the trisomy on platelet functionality that may be relevant in human clinical settings.

Blood ◽  
2008 ◽  
Vol 111 (7) ◽  
pp. 3468-3478 ◽  
Author(s):  
Adoración Venceslá ◽  
María Ángeles Corral-Rodríguez ◽  
Manel Baena ◽  
Mónica Cornet ◽  
Montserrat Domènech ◽  
...  

Abstract Hemophilia A (HA) is an X-linked bleeding disorder caused by a wide variety of mutations in the factor 8 (F8) gene, leading to absent or deficient factor VIII (FVIII). We analyzed the F8 gene of 267 unrelated Spanish patients with HA. After excluding patients with the common intron-1 and intron-22 inversions and large deletions, we detected 137 individuals with small mutations, 31 of which had not been reported previously. Eleven of these were nonsense, frameshift, and splicing mutations, whereas 20 were missense changes. We assessed the impact of the 20 substitutions based on currently available information about FV and FVIII structure and function relationship, including previously reported results of replacements at these and topologically equivalent positions. Although most changes are likely to cause gross structural perturbations and concomitant cofactor instability, p.Ala375Ser is predicted to affect cofactor activation. Finally, 3 further mutations (p.Pro64Arg, p.Gly494Val, and p.Asp2267Gly) appear to affect cofactor interactions with its carrier protein, von Willebrand factor, with the scavenger receptor low-density lipoprotein receptor–related protein (LRP), and/or with the substrate of the FVIIIapi•FIXa (Xase) complex, factor X. Characterization of these novel mutations is important for adequate genetic counseling in HA families, but also contributes to a better understanding of FVIII structure-function relationship.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Miao Wang ◽  
Jane Stubbe ◽  
Eric Lee ◽  
Wenliang Song ◽  
Emanuela Ricciotti ◽  
...  

Microsomal (m) prostaglandin (PG) E 2 synthase(S)-1, an enzyme that catalyzes the isomerization of the cyclooxygenase (COX) product, PGH 2 , into PGE 2 , is a major source of PGE 2 in vivo . mPGES-1 deletion in mice was found to modulate experimentally evoked pain and inflammation and atherogenesis is retarded in mPGES-1 knockout (KO) mice. The impact of mPGES-1 deletion on formation of angiotensin II (Ang II)-induced abdominal aortic aneurysms (AAA) was studied in mice lacking the low density lipoprotein receptor (LDLR −/− ). AngII infusion increased aortic macrophage recruitment and nitrotyrosine staining while upregulating both mPGES-1 and COX-2 and urinary excretion of the major metabolite of PGE 2 (PGE-M). Deletion of mPGES-1 decreased both the incidence and severity of AAA and depressed excretion of both PGE-M and 8, 12-iso-iPF 2a -VI, which reflects lipid peroxidation in vivo . While Ang II infusion augmented prostaglandin biosynthesis, deletion of mPGES-1 resulted in rediversion to PGD 2 , reflected by its major urinary metabolite. However, deletion of the PGD 2 receptor, DP1, did not affect AAA in Ang II infused LDLR −/− mice. These observations indicate that deletion of mPGES-1 protects against AAA formation by AngII in hyperlipidemic mice, perhaps by decreasing oxidative stress. Inhibition of mPGES-1 may represent an effective treatment to limit aneurysm occurrence and expansion.


Nutrients ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 2069 ◽  
Author(s):  
Abigail E. Cullen ◽  
Ann Marie Centner ◽  
Riley Deitado ◽  
Javier Fernandez ◽  
Gloria Salazar

The purpose of this review is to highlight current research on the benefits of supplementation with foods with a diverse polyphenol composition, including fruits, vegetables, nuts, grains, oils, spices, and teas in blunting atherosclerosis. We searched PubMed for publications utilizing whole food or polyphenols prepared from whole foods in Apolipoprotein E (ApoE) or Low-Density Lipoprotein Receptor (LDLR) knockout mice, and identified 73 studies in which plaque was measured. The majority of the studies reported a reduction in plaque. Nine interventions showed no effect, while three using Agaricus blazei mushroom, HYJA-ri-4 rice variety, and safrole-2’, 3’-oxide (SFO) increased plaque. The mechanisms by which atherosclerosis was reduced include improved lipid profile, antioxidant status, and cholesterol clearance, and reduced inflammation. Importantly, not all dietary interventions that reduce plaque showed an improvement in lipid profile. Additionally, we found that, out of 73 studies, only 9 used female mice and only 6 compared both sexes. Only one study compared the two models (LDLR vs. ApoE), showing that the treatment worked in one but not the other. Not all supplementations work in both male and female animals, suggesting that increasing the variety of foods with different polyphenol compositions may be more effective in mitigating atherosclerosis.


2018 ◽  
Vol 47 (1) ◽  
pp. 265-270 ◽  
Author(s):  
Sinan Sarsam ◽  
Abeer Berry ◽  
George Degheim ◽  
Robby Singh ◽  
Marcel Zughaib

Objective Hyperlipidemia is an important risk factor for atherosclerotic cardiovascular disease. Many patients are intolerant to or have limited benefit from statins. Proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors have been approved for treating hyperlipidemia in these patients. We sought to investigate the impact of these medications in a real-world cardiology practice. Methods This was a retrospective study of 17 patients with either heterozygous familial hypercholesterolemia or established atherosclerotic cardiovascular disease with low-density lipoprotein cholesterol (LDL-C) levels above the treatment target despite maximally tolerated statins. Baseline lipid profile was compared with a repeat lipid profile obtained 4 to 6 weeks after initiating treatment with a PCSK9 inhibitor. Results The average duration of PCSK9 inhibitor treatment was 10.7 months. Lipid profile comparison showed that total cholesterol decreased from 243 ± 72 to 148 ± 39 (mg/dL) (39% reduction), triglycerides decreased from 185 ± 86 to 149 ± 62 (mg/dL) (19.5% reduction), high-density lipoprotein cholesterol increased from 56 ± 20 to 62 ± 26 (mg/dL) (10.7% increase), and LDL-C decreased from 154 ± 30 to 57 ± 32 (mg/dL) (63% reduction) from baseline. Conclusions PCSK9 inhibitors as add-on therapy to maximally tolerated statins resulted in an approximately 63% reduction in LDL-C.


2019 ◽  
Vol 116 (7) ◽  
pp. 1254-1274 ◽  
Author(s):  
Chieko Mineo

Abstract The founding member of the lipoprotein receptor family, low-density lipoprotein receptor (LDLR) plays a major role in the atherogenesis through the receptor-mediated endocytosis of LDL particles and regulation of cholesterol homeostasis. Since the discovery of the LDLR, many other structurally and functionally related receptors have been identified, which include low-density lipoprotein receptor-related protein (LRP)1, LRP5, LRP6, very low-density lipoprotein receptor, and apolipoprotein E receptor 2. The scavenger receptor family members, on the other hand, constitute a family of pattern recognition proteins that are structurally diverse and recognize a wide array of ligands, including oxidized LDL. Among these are cluster of differentiation 36, scavenger receptor class B type I and lectin-like oxidized low-density lipoprotein receptor-1. In addition to the initially assigned role as a mediator of the uptake of macromolecules into the cell, a large number of studies in cultured cells and in in vivo animal models have revealed that these lipoprotein receptors participate in signal transduction to modulate cellular functions. This review highlights the signalling pathways by which these receptors influence the process of atherosclerosis development, focusing on their roles in the vascular cells, such as macrophages, endothelial cells, smooth muscle cells, and platelets. Human genetics of the receptors is also discussed to further provide the relevance to cardiovascular disease risks in humans. Further knowledge of the vascular biology of the lipoprotein receptors and their ligands will potentially enhance our ability to harness the mechanism to develop novel prophylactic and therapeutic strategies against cardiovascular diseases.


2019 ◽  
Vol 20 (20) ◽  
pp. 5202 ◽  
Author(s):  
Chen ◽  
Tsui ◽  
Chuang ◽  
Chiang ◽  
Chen ◽  
...  

Carvedilol (Cav), a nonselective β-blocker with α1 adrenoceptor blocking effect, has been used as a standard therapy for coronary artery disease. This study investigated the effects of Cav on exosome expression and function, ATP-binding cassette transporter A1 (ABCA1) expression, and cholesterol efflux that are relevant to the process of atherosclerosis. Human monocytic (THP-1) cell line and human hepatic (Huh-7) cells were treated with Cav, and cholesterol efflux was measured. Exosomes from cell culture medium or mice serum were isolated using glycan-coated recognition beads. Low-density lipoprotein receptor knockout (ldlr−/−) mice were fed with high-fat diet and treated with Cav. Cav accentuated cholesterol efflux and enhanced the expressions of ABCA1 protein and mRNA in both THP-1 and Huh-7 cells. In addition, Cav increased expression and function of exosomal ABCA1 in THP-1 macrophage exosomes. The mechanisms were associated with inhibition of nuclear factor-κB (NF-κB) and protein kinase B (Akt). In hypercholesterolemic ldlr−/− mice, Cav enhanced serum exosomal ABCA1 expression and suppressed atherosclerosis by inhibiting lipid deposition and macrophage accumulation. Cav halts atherosclerosis by enhancing cholesterol efflux and increasing ABCA1 expression in macrophages and in exosomes, possibly through NF-κB and Akt signaling, which provides mechanistic insights regarding the beneficial effects of Cav on atherosclerotic cardiovascular disease.


2020 ◽  
Author(s):  
Xiangyi Cao ◽  
Qiong Kang ◽  
Deng Jiang ◽  
Jun Xiao ◽  
Yanyu Zhang ◽  
...  

Abstract Background: Hepatitis C virus is the major cause of chronic hepatitis which may deteriorate into liver cirrhosis or hepatocellular carcinoma. A number of studies have demonstrated that HCV cell entry is a complex multi-step process involving several cellular proteins, such as scavenger receptor class B type I (SR-BI), tetraspanin CD81, tight junction protein claudin-1 (CLDN-1) and occludin (OCLN). The low-density lipoprotein receptor (LDLR) is an important factor during the initial HCV particle-binding step, which interacts with the complex formed between the virus particle and the lipoprotein in the blood. However, the process of HCV early infection is not well-established, with many details remaining to be elucidated.This research aimed to study the early entry stage of HCV virus particles and the role of LDLR more effectively.Methods: Recombinant murine cell models of HCV infection in vitro was constructed, that expressed human HCV receptors, such as LDLR, CD81, SR BI, CLDN-1, and OCLN. These factors were also introduced to mice by hydrodynamic delivery to construct a humanized mouse model of HCV infection in vivo.Expression levels of the mRNA of HCV entry factors in recombinant cells were measured by qRT-PCR.Western blotting was used to determine whether the recombinant cells successfully expressed cellular proteins. HCV RNA was assayed by q-PCR following the incublation of HCVsd and HCVcc with the transgenice.Results: Transgenic murine cell lines and mice were developed successfully, and expressed four or five human HCV entry factors in tandem or individually, respectively. We found that all of these transgenic cells and mice were susceptible to HCV, and five entry factors (5EF) rendered higher infectivity. Additionally, we observed that four entry factors (4EF/hLDLR-) could facilitate abundant HCV entry, but four other factors (4EF/hSR-BI-) were less effective.Conclusions: Whether in vitro or in vivo, SR-BI is an essential factor in HCV invasion, and target cells and mice were more vulnerable to the virus in the presence of SR-BI than LDLR. These results suggested that SR-BI may be a potential drug target to inhibit HCV early infection, and the absence of LDLR could reduce the infectivity to the virus.


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