Abstract 263: Role of Micro RNA-21 in Atherosclerosis

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Rihab E Hamed-Berair ◽  
Srinivas D Sithu ◽  
Nalinie Wickramasinghe ◽  
Jasmit Shah ◽  
Abhinav Agawral ◽  
...  

Micro RNAs (miR) are short non-coding RNAs that regulate several genes under pathophysiological conditions. Accumulating evidence suggest the involvement of miR in atherogenesis. However, limited information is available about atherogenic miR and the underling mechanisms by which miR affect atherogenesis. Our data shows that 12 weeks of western diet (WD) in LDL receptor-knockout (LDLR-KO) mice upregulated 99 and downregulated 50 miR in the aorta. Among the 41 differentially expressed miR associated with macrophage inflammation and apoptosis, expression of micro RNA-21 (miR-21) was increased by 1.4-fold (P<0.05). WD also increased the expression of miR-21 by 1.5-fold in bone marrow derived macrophages (BMDM). In vitro , LDL, oxidized LDL, acetylated LDL and LPS induced miR-21 by 2-3-fold (P<0.05) and down regulated its target protein PDCD4 in BMDM. Basally, miR-21 deficient BMDM showed increased secretion of IL-6, IL-9 and CXCL-2,-3,-4, and -10 (P<0.05)); and increased early and late apoptosis (2-3-fold, P<0.05). We also observed 40% decrease in the survival of F4/80+ cells during differentiation of bone marrow derived cells isolated from miR-21-KO mice. Stimulation of miR-21-KO BMDM with LPS significantly increased the activation of NF-κB and enhanced the secretion of several pro-inflammatory cytokines including TNFα, IL-6, IL-12 and CXCL-2 (2-10 fold; P<0.05); interferon gamma+LPS polarized the macrophages to pro-inflammatory M1 phenotype (increased expression of CD11c and CD86). Staurosporin and oxidized lipids derived aldehyde 4-hydroxynonenal significantly increased both early and late apoptosis of miR-21-KO BMDM (2-4-fold, P<0.05). This was accompanied by increased cleavage of caspase -3, -7 and -9. Transplantation of bone marrow cells from miR-21-KO into LDLR-KO mice, followed by 12 weeks of WD increased the lesion formation (1.7-fold, P<0.05), apoptosis (3-fold, P<0.05) and necrosis (1.6-fold, P<0.05) in the aortic valve of the chimeric mice. Collectively, these data suggest that miR-21 prevents atherosclerosis, at least in parts, by preventing macrophage apoptosis and inflammation.

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Rihab E Hamed-Berair ◽  
Abhinav Agarwal ◽  
Marcin Wysoczynski ◽  
Srinivas D Sithu ◽  
Nalinie S Wickramasinghe ◽  
...  

Micro RNA-21 (miR-21), an evolutionary conserved micro RNA has been implicated in the pathogenesis of restenosis, myocardial infarction and heart failure. However, little is known about the role of miR-21 in atherosclerosis. Our data show that in vitro, LDL, oxidized LDL, acetylated LDL and LPS induced miR-21 by 2-3-fold (P<0.05) and down regulated its target protein PDCD4 in bone marrow derived macrophages (BMDM). Feeding the LDL receptor-knockout (LDLR-KO) mice with western diet (WD, 8-20 weeks) increased the abundance of miR-21 in BMDM by 1.5-fold (P<0.05). Basally, BMDM isolated from miR-21-KO mice showed induction of TNF alpha, interferon gamma, M-CSF, RANTES, IP10 and LIF by (1.5-3.0-fold); increased early and late apoptosis (2-3-fold, P<0.05); and induced PDCD4 and PTEN. We also observed 40% decrease in the survival of F4/80+ cells during differentiation of bone marrow derived cells isolated from miR-21-KO mice. Stimulation of miR-21-KO BMDM with interferon gamma+LPS polarized the macrophages to pro-inflammatory M1 phenotype (increased expression of CD11c and CD86) and decreased IL-10 formation as compared with WT BMDM. Staurosporin and oxidized lipids derived aldehyde 4-hydroxynonenal significantly increased both early and late apoptosis of miR-21-KO BMDM (2-4-fold, P<0.05). This was accompanied by increased cleavage of caspase 3. Characterization of miR-21-KO mice showed 30% decrease in white blood cells and neutrophils in KO mice. However, levels of circulating immune cells and common progenitor cells in bone marrow of miR-21-KO mice were comparable with wild type mice. Transplantation of bone marrow cells from miR-21-KO into LDLR-KO mice, followed by 12 weeks of WD increased the lesion formation (1.7-fold, P<0.05), apoptosis (3-fold, P<0.05) and necrosis (1.6-fold, P<0.05) in the aortic valve of the chimeric mice. This was accompanied by increased accumulation of macrophages in the non-necrotic areas of the lesion and decrease in lesional smooth muscle cells. Plasma cholesterol levels, and lesional collagen and T-cell levels in the miR-21 chimeric mice were comparable with wild type chimeric mice. Collectively, these data suggest that miR-21 prevents atherosclerosis by inhibiting macrophage apoptosis, necrosis and inflammation.


Blood ◽  
1978 ◽  
Vol 52 (4) ◽  
pp. 712-718 ◽  
Author(s):  
SD Smith ◽  
EM Uyeki ◽  
JT Lowman

Abstract An assay system in vitro for the growth of malignant lymphoblastic colony-forming cells (CFC) was established. Growth of malignant myeloblastic CFC has been previously reported, but this is the first report of growth of malignant lymphoblastic CFC. Established assay systems in vitro have been very helpful in elucidating the control of growth and differentiation of both normal and malignant bone marrow cells. Lymphoblastic CFC were grown from the bone marrow aspirates of 20 children with acute lymphoblastic leukemia. Growth of these colonies was established on an agar assay system and maintained in the relative hypoxia (7% oxygen) of a Stulberg chamber. The criteria for malignancy of these colonies was based upon cellular cytochemical staining characteristics, the presence of specific cell surface markers, and the ability of these lymphoid cells to grow without the addition of a lymphoid mitogen. With this technique, specific nutritional requirements and drug sensitivities can be established in vitro, and these data may permit tailoring of individual antileukemic therapy.


Blood ◽  
1989 ◽  
Vol 73 (7) ◽  
pp. 1836-1841 ◽  
Author(s):  
M Kobayashi ◽  
BH Van Leeuwen ◽  
S Elsbury ◽  
ME Martinson ◽  
IG Young ◽  
...  

Abstract Human bone marrow cells cultured for 21 days in the presence of recombinant human interleukin-3 (IL-3) produced up to 28 times more colony-forming cells (CFC) than could be obtained from cultures stimulated with granulocyte colony stimulating factor (G-CSF) or granulocyte-macrophage CSF (GM-CSF). IL-3-cultured cells retained a multipotent response to IL-3 in colony assays but were restricted to formation of granulocyte colonies in G-CSF and granulocyte or macrophage colonies in GM-CSF. Culture of bone marrow cells in IL-3 also led to accumulation of large numbers of eosinophils and basophils. These data contrast with the effects of G-CSF, GM-CSF, and IL-3 in seven-day cultures. Here both GM-CSF and IL-3 amplified total CFC that had similar multipotential colony-forming capability in either factor. G-CSF, on the other hand, depleted IL-3-responsive colony-forming cells dramatically, apparently by causing these cells to mature into granulocytes. The data suggest that a large proportion of IL-3- responsive cells in human bone marrow express receptors for G-CSF and can respond to this factor, the majority becoming neutrophils. Furthermore, the CFC maintained for 21 days in IL-3 may be a functionally distinct population from that produced after seven days culture of bone marrow cells in either IL-3 or GM-CSF.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3395
Author(s):  
Ting Bei ◽  
Xusong Cao ◽  
Yun Liu ◽  
Jinmei Li ◽  
Haihua Luo ◽  
...  

Total body irradiation is a standard procedure of bone marrow transplantation (BMT) which causes a rapid increase in reactive oxygen species (ROS) in the bone marrow microenvironment during BMT. The increase in ROS reduces the engraftment ability of donor cells, thereby affecting the bone marrow recovery of recipients after BMT. In the early weeks following transplantation, recipients are at high risk of severe infection due to weakened hematopoiesis. Thus, it is imperative to improve engraftment capacity and accelerate bone marrow recovery in BMT recipients. In this study, we constructed recombinant copper/zinc superoxide dismutase 1 (SOD1) fused with the cell-penetrating peptide (CPP), the trans-activator of transcription (Tat), and showed that this fusion protein has penetrating ability and antioxidant activity in both RAW264.7 cells and bone marrow cells in vitro. Furthermore, irradiated mice transplanted with SOD1-Tat-treated total bone marrow donor cells showed an increase in total bone marrow engraftment capacity two weeks after transplantation. This study explored an innovative method for enhancing engraftment efficiency and highlights the potential of CPP-SOD1 in ROS manipulation during BMT.


1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.


1996 ◽  
Vol 90 (2) ◽  
pp. 176-178 ◽  
Author(s):  
Luba Trakhtenbrot ◽  
Yoram Neumann ◽  
Matilda Mandel ◽  
Amos Toren ◽  
Nelly Gipsh ◽  
...  

1999 ◽  
Vol 18 (5) ◽  
pp. 327-335
Author(s):  
Davis H. Daiker ◽  
Jonathan B. Ward ◽  
Heidi A. Schoenfeld ◽  
Gisela Witz ◽  
Mary Treinen Moslen

Although the CD-1 mouse strain has been used to investigate the toxicity of numerous substrates of Cyp2e1, limited information is available about responses of this strain to ethanol, a potent and clinically relevant inducer of this cytochrome P450 isozyme. Our goal was to characterize a dietary ethanol protocol for greater than threefold induction of hepatic Cyp2e1 in CD-1 mice without confounding alterations to other biotransformation enzymes or injury to known target tissues. Female CD-1 mice were fed the Lieber-DeCarli liquid diet containing 1.4 to 6.4% ethanol (v/v) for time periods of 1 to 12 weeks. A series of range-finding experiments indicated that the stock 6.4% ethanol diet caused rapid weight loss, whereas dietary ethanol concentrations less than or equal to 3.2% produced inadequate (i.e., less than threefold) induction of hepatic Cyp2e1. Suitable responses were observed in mice fed a 4.1% ethanol diet, namely, body weight gain equivalent to both pair-fed or rodent chow control groups plus consistent and stable induction of hepatic Cyp2e1 activities by greater than threefold without evidence of hepatic lipid peroxidation or histopathology. Evaluations of other representative biotransformation activities, including bone marrow quinone reductase and hepatic aldehyde dehydrogenase, showed no alterations with the 4.1% ethanol diet, except for a modest 20% decline in hepatic glutathione peroxidase. Unlike observations in other species, Cyp2e1 induction was not evident in bone marrow or spleen by Western blot. Mice given the 4.1% ethanol diet for 6 and/or 12 weeks showed no changes in cellularity of the spleen or bone marrow, frequency of hprt mutations in splenic lymphocytes, or percentage of DNA-protein crosslinks in bone marrow cells. These parameters were monitored because ethanol at high exposures is known to cause immunosuppression and mild genotoxicity. Female CD-1 mice fed a 4.1% ethanol liquid diet showed substantial (greater than threefold) induction of hepatic Cyp2e1 without confounding detrimental effects on the fiver, spleen, or bone marrow. Thus, this dietary ethanol protocol should be useful for future investigations of the role of Cyp2e1 induction on genotoxicity responses to Cyp2e1 substrates.


1980 ◽  
Vol 210 (1180) ◽  
pp. 397-409 ◽  

A comparative study of seven independently isolated defective leukaemia viruses has been carried out. Phenotypic analysis of the chicken bone marrow cells transformed in vitro allowed the separation of these seven viruses into three groups based on the differentiation phenotype of the transformed cell. Nucleic acid hybridization studies revealed that these seven viruses had acquired cellular sequences. Interestingly, these studies also showed that the viruses within the same biological grouping had acquired related sequences. This indicates that viruses that have acquired the same or similar cellular sequences have very similar oncogenic capabilities. Analysis of proteins expressed in cells transformed by these viruses demonstrated that the cellular sequences were usually inserted within the gene for the viral core proteins, gag . Therefore the cellular sequences are expressed as a gag -related fusion protein which has an amino-terminal region derived from the gag gene and a carboxy-terminal half derived from the cellular sequences. Two exceptions to this are discussed. The general conclusion from these studies is that defective leukaemia viruses transform cells by virtue of acquired host cellular sequences. The ability of these viruses to transform cells and the target cell specificity of the transformation depends on these cellular sequences.


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