Alendronate promotes the gene expression of extracellular matrix mediated by SP-1/SOX-9

Background and purpose: Osteoarthritis (OA) is a disease with significant degenerative changes of articular cartilage, which is reported to be closely related to the integrity of chondrocytes extracellular matrix (ECM). Alendronate belongs to the family of bisphosphonates with promising cartilage repair function. In the present study, the effects of Alendronate on the gene expression of chondrocytes ECM and the potential mechanism will be investigated to explore the potential therapeutic property of Alendronate on OA. Methods: Human SW1353 chondrocytes were stimulated with 1 and 2 μM Alendronate for 12 h. The gene expression of Col2α1, COL9α2, and Acan in the treated chondrocytes was determined by qRT-PCR. QRT-PCR and western blot analysis were used to evaluate the expression level of SOX-9 in the treated chondrocytes. The expression level of SP-1 was checked by qRT-PCR and immunostaining. SiRNA against SP-1 was transfected into chondrocytes to knockdown the expression of SP-1. The levels of p-ERK1/2 and total ERK1/2 were examined using western blot analysis. TNF-α was used to induce an OA-like in vitro model in the chondrocytes for therapeutic evaluations. Results: Treatment with Alendronate increased the levels of ECM related genes ( Col2α1, COL9α2, and Acan) in a dose-dependent manner through increasing the expression of SOX-9, a central regulator of ECM genes. Additionally, our findings demonstrate that the effects of Alendronate in the expression of SOX-9 are mediated by SP-1 as silencing of SP-1 abolished these effects. Notably, Alendronate increased the phosphorylation of ERK1/2 and inhibition of ERK1/2 using its specific inhibitor U0126 blocked the expression of SP-1. Finally, we found that treatment with Alendronate could rescue TNF-α-induced reduction of Col2α1, COL9α2, Acan and SOX-9. Conclusion: Our data indicated that Alendronate might promote the gene expression of extracellular matrix through SOX-9 mediated by the ERK1/2/SP1 signaling pathway.

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PIP4KIIα Gene Silencing by Lentivirus-Mediated Delivery of shRNA in Human K562 Cells,

Blood ◽

10.1182/blood.v118.21.3200.3200 ◽

2011 ◽

Vol 118 (21) ◽

pp. 3200-3200

Author(s):

Tânia Regina Zaccariotto ◽

Daniela Maria Ribeiro ◽

Joao Machado-Neto ◽

Magnun N N Santos ◽

Carolina Lanaro ◽

...

Keyword(s):

Gene Expression ◽

Protein Expression ◽

Western Blot ◽

Blot Analysis ◽

Western Blot Analysis ◽

Globin Gene ◽

K562 Cells ◽

Globin Genes ◽

Qrt Pcr ◽

Globin Gene Expression

Abstract Abstract 3200 Background: Phosphatidylinositol-phosphate-kinase type II alpha (PIP4KIIα) belongs to a family of lipid kinases responsible for the production of a variety of lipid second messengers, such as PI4,5P2 (phosphatidylinositol 4,5-biphosphate), and appears to be implicated in the regulation of gene expression, pre-mRNA processing and mRNA export. In a previous study, two transcripts, PIP4KIIα and β-globin, were found to be overexpressed in reticulocytes from two siblings with Hb H disease, suggesting a possible relationship between this enzyme and the production of globins, particularly β-globin. Recently, we established a gene expression pattern for PIP4KIIα in healthy individuals during in vitro erythropoiesis and observed a gradual increase in the expression of this gene during erythroid differentiation similar to that observed for globin genes, reinforcing the hypothesis of a relationship between PIP4KIIα and globin expression. Aim: To investigate the effects of PIP4KIIα gene silencing on the expression of α- and γ-globin genes in human K562 cells. Methods: Two different human K562 cells cultures were transduced with a lentiviral vector encoding PIP4KIIα-specific shRNA or non-relevant control shRNA. After transduction the positive cells were selected by adding puromycin to the culture and collected 2, 6, 8 and 10 days later to analyze gene and protein expression. PIP4KIIα and α- and γ-globin gene expression was assessed by qRT-PCR and quantified using the equation RQ=2−ΔΔCt. Western blot analysis was performed to determine PIP4KIIα protein expression. β-actin and GAPDH were used as endogenous controls in the qRT-PCR, and β-actin in the Western blot. Results: Analysis of the results showed that there was a statistically significant reduction in PIP4KIIα mRNA levels in knockdown cells (79%) (0.208 ± 0.048; p<0.0001) compared with the control culture. Western blot analysis corroborated these findings. PIP4KIIα silencing resulted in an 18% (0.927 ± 0.244; p=0.09) and 44% (0.625 ± 0.124; p=0.03) reduction in the expression of α- and γ-globin genes, respectively, compared with the control. Conclusion: Although the reduction in α-globin gene expression did not achieve statistical significance, our results revealed alterations in α- and γ-globin gene expression in PIP4KIIα knockdown cells, suggesting a parallelism between the expression of PIP4KIIα and globin genes and reinforcing the hypothesis that the former may be involved in regulation of the latter. This work was supported by FAPESP, CNPq and INCTS. Disclosures: No relevant conflicts of interest to declare.

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Hypoxia-inducible erythropoietin gene expression in human neuroblastoma cells

Blood ◽

10.1182/blood-2001-12-0169 ◽

2002 ◽

Vol 100 (7) ◽

pp. 2623-2628 ◽

Cited By ~ 48

Author(s):

Ineke Stolze ◽

Utta Berchner-Pfannschmidt ◽

Patricia Freitag ◽

Christoph Wotzlaw ◽

Jochen Rössler ◽

...

Keyword(s):

Gene Expression ◽

Western Blot ◽

Blot Analysis ◽

Western Blot Analysis ◽

Hepatoma Cell ◽

Hepatoma Cell Line ◽

Dependent Manner ◽

Independent Manner ◽

Human Neuroblastoma ◽

Α Subunit

Two human neuroblastoma (NB) cell lines, SH-SY5Y and Kelly, were found to express the gene for erythropoietin (EPO) in an oxygen (O2)-dependent manner. However, NB cells had maximal production of EPO with lower partial pressure of O2 values than the well-characterized hepatoma cell line HepG2. This maximal EPO expression was preceded by accumulation of the O2-sensitive α subunit of the heterodimeric transcription-factor complex hypoxia-inducible factor 1 (HIF-1). Western blot analysis revealed that the amount of the β subunit of HIF-1, identical to aryl hydrocarbon receptor nuclear translocator 1 (ARNT1), and the homolog ARNT2 increased in nuclear extracts from SH-SY5Y cells exposed to anoxia. In neuronal cells, ARNT1 and ARNT2 can form a heterodimer with HIF-1α, generating a functional HIF-1 complex. Using the hypoxia response element of the human EPO enhancer, we conducted electrophoretic mobility shift assays that showed accumulation and binding of HIF-1 complexes containing both ARNT1 and ARNT2 in NB cells. In addition to the HIF-1 complex, hepatocyte nuclear factor 4α (HNF4α) was found to be indispensable for hypoxia-induced EPO gene expression in hepatoma cells. Western blot analysis and polymerase chain reaction assessment showed that NB cells express neither HNF4α nor the splicing variant HNF4α7 and thus express EPO in an HNF4α-independent manner. Together, SH-SY5Y and Kelly cells may provide a new in vitro model for studying the mechanism of tissue-specific, hypoxia-inducible EPO gene expression.

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Sinoacutine inhibits inflammatory responses to attenuates acute lung injury by regulating NF-κB and JNK signaling pathways

BMC Complementary Medicine and Therapies ◽

10.1186/s12906-021-03458-0 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Yuancui Zhao ◽

Lili Cui ◽

Xing Xin Yang ◽

Xingqian Sun ◽

Yunkuan Liu ◽

...

Keyword(s):

Gene Expression ◽

Nitric Oxide ◽

Acute Lung Injury ◽

Lung Injury ◽

Western Blot ◽

Blot Analysis ◽

Western Blot Analysis ◽

Signalling Pathway ◽

Tnf Α ◽

Anti Inflammatory

Abstract Background Stephania yunnanensis H. S. Lo is widely used as an antipyretic, analgesic and anti-inflammatory herbal medicine in SouthWest China. In this study, we investigated the anti-inflammatory activity and mechanism of sinoacutine (sino), one of the primary components extracted from this plant. Methods A RAW264.7 cell model was established using lipopolysaccharide (LPS) induced for estimation of cytokines in vitro, qPCR was used to estimate gene expression, western blot analysis was used to estimate protein level and investigate the regulation of NF- κB, JNK and MAPK signal pathway. In addition, an acute lung injury model was established to determine lung index and levels of influencing factors. Results Using the RAW264.7 model, we found that sino reduced levels of nitric oxide (NO), tumour necrosis factor-α (TNF-α), interleukin (IL)-1β and prostaglandin E2 (PGE2) but increased levels of IL-6. qPCR analysis revealed that sino (50, 25 μg/ml) inhibited gene expression of nitric oxide synthase (iNOS). western blot analysis showed that sino significantly inhibited protein levels of both iNOS and COX-2. Further signalling pathway analysis validated that sino also inhibited phosphorylation of p65 in the NF-κB and c-Jun NH2 terminal kinase (JNK) signalling pathways but promoted the phosphorylation of extracellular signal regulated kinase (ERK) and p38 in the MAPK signalling pathway. In addition, in a mouse model induced by LPS, we determined that sino reduced the lung index and the levels of myeloperoxidase (MPO), NO, IL-6 and TNF-α in lung tissues and bronchoalveolar lavage fluid (BALF) in acute lung injury (ALI). Conclusion Taken together, our results demonstrate that sino is a promising drug to alleviate LPS-induced inflammatory reactions.

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Semaphorin 3A Inhibits Inflammation in Chondrocytes under Excessive Mechanical Stress

Mediators of Inflammation ◽

10.1155/2018/5703651 ◽

2018 ◽

Vol 2018 ◽

pp. 1-9 ◽

Cited By ~ 13

Author(s):

Chikako Sumi ◽

Naoto Hirose ◽

Makoto Yanoshita ◽

Mami Takano ◽

Sayuri Nishiyama ◽

...

Keyword(s):

Gene Expression ◽

Western Blot ◽

Mechanical Stress ◽

Inflammatory Cytokines ◽

Blot Analysis ◽

Western Blot Analysis ◽

Dependent Manner ◽

Semaphorin 3A ◽

Neuropilin 1 ◽

Dose Dependent

Background. Excessive mechanical stress causes inflammation and destruction of cartilage and is considered one of the cause of osteoarthritis (OA). Expression of semaphorin 3A (Sema3A), which is an axon guidance molecule, has been confirmed in chondrocytes. However, there are few reports about Sema3A in chondrocytes, and the effects of Sema3A on inflammation in the cartilage are poorly understood. The aim of this study was to examine the role of Sema3A in inflammation caused by high magnitude cyclic tensile strain (CTS). Methods. Expression of Sema3A and its receptors neuropilin-1 (NRP-1) and plexin-A1 (PLXA1) in ATDC5 cells was examined by Western blot analysis. ATDC5 cells were subjected to CTS of 0.5 Hz, 10% elongation with added Sema3A for 3 h. Gene expression of IL-1β, TNF-ɑ, COX-2, MMP-3, and MMP-13 was examined by qPCR analysis. Furthermore, the phosphorylation of AKT, ERK, and NF-κB was detected by Western blot analysis. Results. Added Sema3A inhibited the gene expression of inflammatory cytokines upregulated by CTS in a dose-dependent manner. Addition of Sema3A suppressed the activation of AKT, ERK, and NF-κB in a dose-dependent manner. Conclusions. Sema3A reduces the gene expression of inflammatory cytokines by downregulating the activation of AKT, ERK, and NF-κB pathways in ATDC5 cells under CTS.

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TAT/HDL Induces the Phospholylation of Cofilin in the Process of Platelet Production of Megakaryocytes.

Blood ◽

10.1182/blood.v104.11.2186.2186 ◽

2004 ◽

Vol 104 (11) ◽

pp. 2186-2186

Author(s):

Yoji Ishida ◽

Syugo Kowata ◽

Kazunori Murai ◽

Tatsuo Oyake ◽

Shigeki Ito

Keyword(s):

Western Blot ◽

Blot Analysis ◽

Western Blot Analysis ◽

Specific Inhibitor ◽

Density Lipoprotein ◽

Bound State ◽

Dependent Manner ◽

Lim Kinase ◽

Serum Free ◽

Platelet Production

Abstract In the previous ASH Meetings, we have reported that thrombin/antithrombin complex in association with high density lipoprotein (TAT/HDL) directly stimulated proplatelet formation (PPF) of human or murine megakaryocytes. In this study, we investigated the signal transduction pathways responsible for platelet production from megakaryocytes using human megakaryoblastic cell line (MEG). TAT/HDL stimulated MEGs to induce the many platelet-like particles (PP) around the cells in the serum free culture during 12~24 hrs (Fig. 1). The frequency of MEGs with PP increased with the increase of TAT/HDL in a dose dependent manner (0 μg/ml: 1.8±0.5%, 50 μg/ml: 30.8±4.5%, 100 μg/ml: 46.5±7.8%, 200 μg/ml: 57.8±8.3%, mean±SD, n=4). The frequency of MEGs with PP, expressed as a pecentage of the control, was significantly decreased after the incubation with TAT/HDL(150 μg/ml) and Y27632, a specific inhibitor for Rho kinase(ROCK), (Y27632 10 μM: 61.3±7.9% of the control (p<0.01), 100 μM: 12.5±5.9% of the control (p<0.01), mean±SD, n=4). MEGs were incubated with TAT/HDL (150 μg/ml) in serum free condition for 5, 10, 15, 30, 60, 90, 120, 150 and 180 min. MEGs were havested, washed twice and lysed by the lysis buffer (50mM Tris/HCl, 150 mM NaCl. 0.5% Nonidet P-40 pH 6.8 with protease inhibitors’ cocktail) for the Western blot analysis. Activated Rho (GTP-bound state Rho), measured by the Western blot using Rhotekin-Rho binding domain (RBD) beads and anti-Rho antibody, increased at 90, 120 and 150 min after the incubation. ROCK was co-precipitated with activated Rho using Rhotekin-RBD beads and detected by the Western blot analysis using anti-ROCK antibody at 90, 120 and 150 min. LIM kinase was immunoprecipitated with ROCK/anti-ROCK antibody and protein G sepharose. Western blot analysis using anti-phosphothreonine antibody revealed that LIM-kinase was phospholylated at 90, 120 and 150 min after the incubation. Phospholylated cofilin (Ser3) expression was detected by the Western blot using anti-phosphocofilin antibody at 60 min, peaked at 120 min and tapered at 150 min after the incubation (Fig.2). The intensity of the phospholylated cofilin (Ser3) band decreased in the incubation of MEGs with TAT/HDL and Y27632 (100 μM) at each time. These results strongly suggested the platelet-like particles production from MEGs, stimulated by TAT/HDL, was involved in the pathway from Rho activation, ROCK activation, LIM kinase phospholylation and cofilin phospholylation, based on the evidence that phospholylated cofilin showed the inhibition of actin depolymerization and the stabilization of actin filaments. Fig.1 (a) MEGs with no stimulation (b) MEGs with TAT/HDL (200 μg/ml) for 24h Fig.2 Expression of phospholylated cofilin (Ser3). Figure Figure Figure Figure

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Punicalagin Prevents Inflammation in LPS-Induced RAW264.7 Macrophages by Inhibiting FoxO3a/Autophagy Signaling Pathway

Nutrients ◽

10.3390/nu11112794 ◽

2019 ◽

Vol 11 (11) ◽

pp. 2794 ◽

Cited By ~ 8

Author(s):

Cao ◽

Chen ◽

Ren ◽

Zhang ◽

Tan ◽

...

Keyword(s):

Western Blot ◽

Signaling Pathway ◽

Inflammatory Cytokines ◽

Blot Analysis ◽

Western Blot Analysis ◽

Inflammatory Responses ◽

Raw264.7 Macrophages ◽

Tnf Α ◽

Autophagy Inhibition ◽

Pro Inflammatory Cytokines

Punicalagin, a hydrolysable tannin of pomegranate juice, exhibits multiple biological effects, including inhibiting production of pro-inflammatory cytokines in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In this study, we investigated the anti-inflammatory potential of punicalagin in lipopolysaccharide (LPS) induced RAW264.7 macrophages and uncovered the underlying mechanisms. Punicalagin significantly attenuated, in a concentration-dependent manner, LPS-induced release of NO and decreased pro-inflammatory cytokines TNF-α and IL-6 release at the highest concentration. We found that punicalagin inhibited NF-κB and MAPK activation in LPS-induced RAW264.7 macrophages. Western blot analysis revealed that punicalagin pre-treatment enhanced LC3II, p62 expression, and decreased Beclin1 expression in LPS-induced macrophages. MDC assays were used to determine the autophagic process and the results worked in concert with Western blot analysis. In addition, our observations indicated that LPS-induced releases of NO, TNF-α, and IL-6 were attenuated by treatment with autophagy inhibitor chloroquine, suggesting that autophagy inhibition participated in anti-inflammatory effect. We also found that punicalagin downregulated FoxO3a expression, resulting in autophagy inhibition. Overall these results suggested that punicalagin played an important role in the attenuation of LPS-induced inflammatory responses in RAW264.7 macrophages and that the mechanisms involved downregulation of the FoxO3a/autophagy signaling pathway.

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Abstract 2671: Thymosin Beta 4 Induced Oligodendrogenesis Is Associated With Upregulation Of Serum Response Factor

Stroke ◽

10.1161/str.43.suppl_1.a2671 ◽

2012 ◽

Vol 43 (suppl_1) ◽

Author(s):

Daniel C Morris ◽

Benjamin Buller ◽

Manoranjan Santra ◽

Michael Chopp ◽

Zheng Gang Zhang

Keyword(s):

Western Blot ◽

Progenitor Cells ◽

Rat Model ◽

Blot Analysis ◽

Western Blot Analysis ◽

Embolic Stroke ◽

Early Gene ◽

Dependent Manner ◽

Thymosin Beta 4 ◽

Serum Response

Background: Thymosin beta 4 (Tβ4) is a G-actin sequestering peptide that improves neurological functional outcome when administered 24 hours after onset of stroke to a rat model of embolic stroke. Tβ4 increases the number of oligodendrocyte progenitor cells (OPCs) as well as mature oligodendrocytes (OLs). Mechanisms of Tβ4 induced oligodendrogenesis (OLG) remain unclear. Serum response growth factor (SRF) is a transcriptional factor which binds with ternary complex co-factors to primarily convey an immediate early gene response to influence and orchestrate neuronal migration and differentiation. Hypothesis: We tested the hypothesis that Tβ4 upregulates SRF with subsequent increase in the markers of OL differentiation. Results: We employed a mouse OPC line (N20.1) to investigate the mechanisms of Tβ4-induced OLG. The cells were plated at a density of 100,000 cells/ml and grown in the presence of 0, 12.5, 25 and 50 ng/ml of Tβ4 (RegeneRx Biopharmaceuticals, Inc.) for 14 days (n=3). Western blot analysis revealed that SRF was dose-dependently upregulated by a factor of 4. Quantitative real time PCR and Western blot analysis showed that Tβ4 treatment induced myelin basic protein (MBP) and 2’, 3’-cyclic nucleotide, 3’-phosphodiesterase (CNPase) expression in a dose-dependent manner by ∼2 fold, indicating the stimulation of OLG. In order to independently demonstrate that SRF promotes the differentiation of progenitor cells into mature oligodendrocytes, SRF was over expressed in the N20.1 cells using a plasmid encoding the SRF gene. After six days SRF over expressed N20.1 cells (n=3) demonstrated an increase of expression of MBP (26 ± 3%) and CNPase (23 ± 3%) when compared to cells transfected with an empty expression plasmid (n=3, MBP, 14 ± 3% and CNPase, 10 ± 4%, p<0.05). Conclusions: In this mouse model of OPCs, SRF was upregulated by Tβ4 and may be involved in Tβ4 induced OLG. Further in vivo investigation of SRF is warranted in our rat model of embolic stroke.

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P–543 Inhibition of cell proliferation and extracellular matrix formation in human uterine leiomyomas by 5-aza–2’-deoxycitidine via Wnt/ β-catenin pathway

Human Reproduction ◽

10.1093/humrep/deab130.542 ◽

2021 ◽

Vol 36 (Supplement_1) ◽

Author(s):

M C Carbajo-García ◽

A Corachán ◽

M Segura ◽

J Monleón ◽

J Escrig ◽

...

Keyword(s):

Gene Expression ◽

Dna Methylation ◽

Extracellular Matrix ◽

Cell Proliferation ◽

Protein Expression ◽

Hormonal Treatment ◽

Dependent Manner ◽

Dnmt Inhibitors ◽

Qrt Pcr ◽

Dose Dependent

Abstract Study question Is DNA methylation reversion through DNA methyltransferases (DNMT) inhibitors, such as 5-aza–2’-deoxycitidine, a potential therapeutic option for treatment of patients with uterine leiomyomas (UL)? Summary answer 5-aza–2’-deoxycitidine reduces proliferation and extracellular matrix (ECM) formation by inhibition of Wnt/ β-catenin pathway on UL cells, suggesting DNMT inhibitors as an option to treat UL. What is known already: UL is a multifactorial disease with an unclear pathogenesis and inaccurate treatment. Aberrant DNA methylation have been found in UL compared to myometrium (MM) tissue, showing hypermethylation of tumor suppressor genes, which contributes to the development of this tumor. The use of DNMT inhibitors, such as 5-aza–2’-deoxycytidine (5-aza-CdR), has been suggested to treat tumors in which altered methylation pattern is related to tumor progression, as occurs in UL. Based on this, we aimed to evaluate whether DNA methylation reversion through 5-aza-CdR reduces cell proliferation and ECM formation in UL cells, being a potential option for UL medical treatment. Study design, size, duration Prospective study comparing UL versus MM tissue and human uterine leiomyoma primary (HULP) cells treated with/without 5-aza-CdR at 0 µM (control), 2 µM, 5 µM and 10 µM for 72 hours. UL and MM tissue were collected from women without any hormonal treatment for the last 3 months (n = 16) undergoing myomectomy or hysterectomy due to symptomatic leiomyoma pathology. Participants were recruited between January 2019 and February 2020 at Hospital Universitario y Politecnico La Fe (Spain). Participants/materials, setting, methods Samples were collected from Caucasian premenopausal women aged 31–48 years, with a body mass index of < 30 and without hormonal treatment. DNMT1 gene expression was analysed in UL vs MM tissue by qRT-PCR and activity of DNMT was measured in UL and MM tissue and cells by ELISA. 5-aza-CdR effect on proliferation was assessed by CellTiter test and Western blot (WB), apoptosis and ECM analyzed by WB and Wnt/ β-catenin pathway by qRT-PCR and WB. Main results and the role of chance: DNMT1 gene expression was increased in UL compared to MM tissue (fold change [FC]=2.49, p-value [p]=0.0295). Similarly, DNMT activity was increased in both UL compared to MM tissue and HULP cells versus MM cells (6.50 vs 3.76 OD/h/mg, p = 0.026; 211.30 vs 63.67 OD/h/mg, p = 0.284, respectively). After 5-aza-CdR treatment, cell viability of HULP cells was reduced in a dose dependent manner, being statistically significant at 10 µM (85.25%, p = 0.0001). Accordantly, PCNA protein expression was significantly decreased at 10 µM in HULP cells (FC = 0.695, p = 0.034), demonstrating cell proliferation inhibition. Additionally, 5-aza-CdR inhibited ECM protein expression in HULP cells in a dose-dependent manner being statistically significant at 10 µM for COLLAGEN I (FC = 0.654, p = 0.023) and PAI–1 (FC = 0.654, p = 0.023), and at 2 µM and 10 µM for FIBRONECTIN (FC = 0.812, p = 0.020; FC = 0.733, p = 0.035; respectively). Final targets of Wnt/ β-catenin pathway were decreased after 5-aza-CdR treatment, protein expression of WISP1 was significantly inhibited at 10 µM (FC = 0.699, p = 0.026), while expression levels of Wnt/ β-catenin target genes C-MYC (FC = 0.745, p = 0.028 at 2 µM; FC = 0.728, p = 0.019 at 10 µM) and MMP7 (FC = 0.520, p = 0.003 at 5 µM, FC = 0.577, p = 0.007 at 10 µM) were also significantly downregulated in HULP-treated cells vs untreated cells. Limitations, reasons for caution: This study has strict inclusion criteria to diminish epigenetic variability, thereby we should be cautious extrapolating our results to general population. Besides, this is a proof of concept with the inherent cell culture limitations. Further studies are necessary to determine 5-aza-CdR dose and adverse effects on UL in vivo. Wider implications of the findings: 5-aza-CdR treatment reduces cell proliferation and ECM formation through Wnt/ β-catenin pathway inhibition, suggesting that inhibition of DNA methylation could be a promising new therapeutic approach to treat UL. Trial registration number Not applicable

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Abstract 663: Identification of 2 Novel Candidate Genes of Atherosclerosis Susceptibility on Mouse Chromosome 3: Pla2g12a and Elovl6

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvb.34.suppl_1.663 ◽

2014 ◽

Vol 34 (suppl_1) ◽

Author(s):

Alexandros Nicolaou ◽

Kristina Sass ◽

Bernd H Northoff ◽

Daniel Teupser ◽

Lesca M Holdt

Keyword(s):

Western Blot ◽

Candidate Genes ◽

Mouse Chromosome ◽

Blot Analysis ◽

Western Blot Analysis ◽

Ldl Receptor ◽

Atherosclerotic Lesion ◽

Lesion Size ◽

Specific Expression ◽

Qrt Pcr

Quantitative trait locus (QTL) mapping in an F2 intercross (n=452) of atherosclerosis-susceptible C57BL/6 (B6) and atherosclerosis-resistant FVB mice on the LDL-receptor deficient background revealed a novel atherosclerosis susceptibility locus on mouse chromosome (Chr) 3. In previous work the susceptible genetic region on Chr3 was narrowed to 80 - 160 MB and validated by congenic FVB.Chr3 B6/B6 mice. We hypothesized that underlying genetic variation in this region leads to differential expression of causal genes, thereby affecting atherosclerosis susceptibility. We performed transcriptome-wide expression analyses in livers of congenic FVB.Chr3 B6/B6 and FVB mice (n=4/4) using Illumina Ref-8 arrays followed by validation in livers of congenic FVB.Chr3 B6/B6 and FVB mice (n=8/9) as well as in livers of B6 and FVB mice (n=5/5) by quantitative real-time PCR (qRT-PCR). C is -regulation was investigated in F2 livers (n=47) by correlating the expression to the genotype. Tissue-specific expression of genes was examined by qRT-PCR in parental B6 and FVB mice. Western blot analysis and immunohistochemical staining (IHC) were performed. Mechanisms of atherogenesis were investigated by RNAi. Pla2g12a and Elovl6 were identified as candidate genes co-segregating with the atherosclerosis QTL at marker rs13464244. Pla2g12a mRNA expression was inversely correlated (r 2 =0.2, p=0.002) with atherosclerotic lesion size in F2 mice while Elovl6 expression was positively correlated (r 2 =0.18, p=0.002). qRT-PCR revealed a strong expression of Pla2g12a in muscle and fat tissues whereas Elovl6 was highly expressed in liver and fat tissues. Western blot analysis revealed significantly decreased protein expression of Pla2g12a in livers of B6 compared to FVB and an increased expression of Elovl6 in B6 mice. IHC staining of Pla2g12a and Elovl6 in aortic roots indicated high expression in macrophages and predominantly in endothelial cells. siRNA knockdown of Elovl6 was associated with reduced adhesion and increased apoptosis. In conclusion, we identified Elovl6 and Pla2g12a as promising candidate genes of atherosclerosis susceptibility on mouse Chr3. Further work is necessary to better understand the influence of these two genes on atherosclerosis development.

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