MCP-1 mRNA Research Articles

482-P: Linagliptin Induces M2 Macrophage Polarization and Suppresses Progression of Atherosclerosis in High-Fat-Fed ApoE-Deficient Mice

Background: Dipeptidyl peptidase-4 (DPP-4) inhibitors suppressed the progression of atherosclerosis in atherosclerotic mouse models. However, exact mechanism has been unclear. In this study, we investigated whether linagliptin suppressed progression of atherosclerosis in high fat diet (HFD)-fed apolipoprotein-E-deficient (ApoE KO) mice via anti-inflammatory effects on macrophages. Methods: HFD-fed ApoE KO mice were treated orally with linagliptin (10 mg/kg/day). After 8 weeks of treatment, whole aorta and aortic sinus were stained with Oil red O, or anti-4-Hydroxynonenal (4-HNE) and anti-F4/80 antibodies. Mouse bone marrow-derived macrophages were used in vitro study. Intracellular ROS generation was evaluated by H2DCF-DA assay. Expression of iNOS, MCP-1, TNF-α, arginase-1, Mgl2 and Ym1 mRNA, and macrophage polarization were evaluated by real-time RT-PCR and FACS scan, respectively. Results: There were no significant differences on food intake, body weight, blood glucose levels between each group, but cholesterol concentrations in VLDL and LDL particle were lower in linagliptin group. Oil-Red-O staining demonstrated that size of atherosclerotic lesions was decreased in linagliptin group. The 4-HNE-positive area and number of macrophages in plaques were decreased, and mRNA expression of arginase-1, Mgl2 and Ym1 in the aorta were higher in linagliptin groups than those in control groups. Linagliptin suppressed ROS generation, increased mRNA expression of arginase-1, Mgl2 and Ym1, and ameliorated LPS+IFNγ-induced reduction of M2 macrophages. Conclusion: This study suggests that linagliptin suppresses the progression of atherosclerosis in HFD-fed apoE KO mice. Moreover, linagliptin suppresses ROS generation and increases the polarization of M2 macrophages. These findings may indicate the beneficial effects of linagliptin for the prevention of diabetic macrovascular complications. Disclosure S. Nishida: None. T. Matsumura: None. T. Senokuchi: None. N. Ishii: None. S. Murakami-Nishida: None. S. Yamada: None. Y. Morita: None. T. Wada: None. H. Motoshima: None. T. Kondo: None. E. Araki: Research Support; Self; Astellas Pharma Inc., Boehringer Ingelheim Pharmaceuticals, Inc., Daiichi Sankyo Company, Limited, Novo Nordisk Inc., Takeda Pharmaceutical Company Limited. Speaker's Bureau; Self; Astellas Pharma Inc., Merck & Co., Inc., Novo Nordisk Inc., Ono Pharmaceutical Co., Ltd., Sanofi.

Lactobacillus rhamnosus GG Ameliorates Liver Injury and Hypoxic Hepatitis in Rat Model of CLP-Induced Sepsis.

Probiotic use to prevent gastrointestinal infections in critical care has shown great promise in recent clinical trials. Although well-documented benefits of probiotic use in intestinal disorders, the potential for probiotic treatment to ameliorate liver injury and hypoxic hepatitis following sepsis has not been well explored. In order to evaluate, if Lactobacillus rhamnosus GG (LGG) treatment in septic rats will protect against liver injury, this study used 20-22-week-old Sprague-Dawley rats which were subjected to cecal ligation and puncture to establish sepsis model and examine mRNA and protein levels of IL-1β, NLRP3, IL-6, TNF-a, VEGF, MCP1, NF-kB and HIF-1α in the liver via real-time PCR, Elisa and Western blot. This study showed that LGG treatment significantly ameliorated liver injury following experimental infection and sepsis. Liver mRNA and protein levels of IL-1β, NLRP3, IL-6, TNF-a, VEGF, MCP1, NF-kB and HIF-1α were significantly reduced in rats receiving LGG. Thus, our study demonstrated that LGG treatment can reduce liver injury following experimental infection and sepsis and is associated with improved hypoxic hepatitis. Probiotic therapy may be a promising intervention to ameliorate clinical liver injury and hypoxic hepatitis following systemic infection and sepsis.

Estrogen Modulates the Differential Expression of Cardiac Myocyte Chymase Isoforms and Diastolic Function

Background and objectiveCardiac angiotensin II (Ang II) is involved in the diastolic dysfunction in postmenopausal women. Chymases, a family of serine proteases with chymotryptic activity, play a significant role in cardiac Ang II formation from its substrate Ang‐(1–12) in both human and rodent models. While human tissue expresses only the α‐form of chymase, α‐ and β‐forms exist in rodents. Five of the ten rat mast cell proteases (rMCP‐1–5) display chymase activity, and rats express predominantly the β‐chymase isoforms. This study was designed to assess the differences in enzymatic activity among these rMCP isoforms in Ang II formation, particularly in the cardiomyocyte (CM), and the effects of estrogen status on MCP gene expression and activities in female rat models.Methods and resultsUsing conventional polymerase chain reaction (PCR) (Fig. 1A), real‐time PCR (Fig. 1B) and DNA sequencing (Fig. 1C), we demonstrated that MCP‐1, MCP‐2, MCP‐4, and MCP‐5 mRNAs are expressed in the CM of both spontaneously hypertensive rats (SHR) and normotensive Wistar‐Kyoto rats (WKY). While rMCP‐1 and rMCP‐5 gene transcripts were higher than other isoforms in both rat strains, WKY CM exhibits higher levels of rMCP‐1 and rMCP‐5 mRNAs compared to the SHR CM (Fig. 2). Ovariectomy (OVX) increased the expression of rMCP‐1 and rMCP‐5 mRNAs in WKY. In SHR, OVX was associated with a blunted increase in rMCP‐1 mRNA compared to OVX normotensive WKY. Chymase activity, measured by HPLC as Ang II formation from Ang‐(1–12), significantly correlated with rMCP‐1 and rMCP‐5 mRNA expression in both rat strains. Both rMCP‐1 and rMCP‐5 mRNA expressions were positively correlated with progressive diastolic dysfunction (increasing the ratio of early mitral inflow velocity‐to‐early mitral annular velocity, E/e′) and increases in left ventricular internal diameter end diastole.ConclusionThese data show rMCP‐1 and rMCP‐5 as the Ang II forming chymase isoforms participating in diastolic dysfunction due to ovariectomy in rodents.Support or Funding InformationThis work was funded by grants from the National Heart Lung and Blood Institute (CMF and LG) P01‐HL051952 and the National Institute on Aging (LG) AG033727 of the National Institute of Health.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Dynamic Profile of CD4+ T-Cell-Associated Cytokines/Chemokines following Murine Myocardial Infarction/Reperfusion.

CD4+ T-cells play crucial roles in the injured heart. However, the way in which different CD4+ T subtypes function in the myocardial infarction/reperfusion (MI/R) heart is still poorly understood. We aimed to detect the dynamic profile of distinct CD4+ subpopulation-associated cytokines/chemokines by relying on a closed-chest acute murine MI/R model. The protein levels of 26 CD4+ T-cell-associated cytokines/chemokines were detected in the heart tissues and serum of mice at day 7 and day 14 post-MI/R or sham surgery. The mRNA levels of IL-4, IL-6, IL-13, IL-27, MIP-1β, MCP-3, and GRO-α were measured in blood mononuclear cells. The protein levels of IL-4, IL-6, IL-13, IL-27, MIP-1β, MCP-3, and GRO-α increased in both injured heart tissues and serum, while IFN-γ, IL-12P70, IL-2, IL-1β, IL-18, TNF-α, IL-5, IL-9, IL-17A, IL-23, IL-10, eotaxin, MIP-1α, RANTES, MCP-1, and MIP-2 increased only in MI/R heart tissues in the day 7 and day 14 groups compared to the sham group. In serum, the IFN-γ, IL-23, and IL-10 levels were downregulated in the MI/R model at both day 7 and day 14 compared to the sham. Compared with the protein expressions in injured heart tissues at day 7, IFN-γ, IL-12P70, IL-2, IL-18, TNF-α, IL-6, IL-4, IL-5, IL-9, IL-17A, IL-23, IL-27, IL-10, eotaxin, IP-10, RANTES, MCP-1, MCP-3, and GRO-α were reduced, while IL-1β and MIP-2 were elevated at day 14. IL-13 and MIP-1β showed higher levels in the MI/R serum at day 14 than at day 7. mRNA levels of IL-4, IL-6, IL-13, and IL-27 were increased in the day 7 group compared to the sham, while MIP-1β, MCP-3, and GRO-α mRNA levels showed no significant difference between the MI/R and sham groups in blood mononuclear cells. Multiple CD4+ T-cell-associated cytokines/chemokines were upregulated in the MI/R hearts at the chronic stage. These results provided important evidence necessary for developing future immunomodulatory therapies after MI/R.

Oral cholecalciferol supplementation alleviates lipopolysaccharide-induced preterm delivery partially through regulating placental steroid hormones and prostaglandins in mice

Several epidemiological reports demonstrated that vitamin D deficiency elevated risk of preterm delivery. We investigate the effects of oral cholecalciferol (VD3) supplementation on lipopolysaccharide (LPS)-induced preterm delivery. Pregnant mice were randomly assigned to either oral VD3 (25 μg/kg) or corn oil once daily from gestational day (GD)13 to GD15, and were intraperitoneally injected with either LPS (200 μg/kg) or normal saline on GD15. As expected, LPS was effective in inducing preterm delivery and fetal death. LPS-induced preterm delivery and fetal death were alleviated in VD3-pretreated mice. LPS-induced down-regulation of genes for placental progesterone biosynthetic enzymes was blocked in VD3-pretreated mice. LPS-induced reduction of serum progesterone was correspondingly attenuated by VD3. Although oral VD3 had no effect on estradiol production, it attenuated LPS-induced up-regulation of placental ERβ in mice. LPS-induced placental COX-2 up-regulation and serum PGF2α elevation were alleviated in VD3-pretreated mice. Additionally, LPS-evoked elevations of the placental Tnfα, Il1β, Mcp1 and Mip2 mRNAs were attenuated by VD3. VD3 promoted placental vitamin D receptor nuclear translocation and simultaneously alleviated LPS-induced nuclear translocation of NF-κB p65 and p50 subunits. These results provide evidence that oral VD3 supplementation alleviates LPS-induced preterm delivery and fetal demise partially through regulating placental steroid hormones and prostaglandins.

Estrogen modulates the differential expression of cardiac myocyte chymase isoforms and diastolic function.

Chymases, a family of serine proteases with chymotryptic activity, play a significant role in cardiac angiotensin II (Ang II) formation from its substrate Ang-(1-12) in both human and rodent models. No studies, to date, have assessed the differences in enzymatic activity among these isoforms in Ang II formation, particularly in the cardiomyocyte (CM). Using PCR and DNA sequencing, we demonstrated that MCP-1, MCP-2, MCP-4, and MCP-5 mRNAs are expressed in the CM of both spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). While rMCP-1 and rMCP-5 gene transcripts were higher than that of other isoforms in both rat strains, WKY CM exhibits higher levels of rMCP-1 and rMCP-5 mRNAs compared to the SHR CM. Ovariectomy (OVX) increased the expression of rMCP-1 and rMCP-5 mRNAs in WKY. In SHR, OVX was associated with a blunted increase in rMCP-1 mRNA compared to OVX normotensive WKY. Chymase activity, measured as Ang II formation from Ang-(1-12), significantly correlated with rMCP-1 and rMCP-5 mRNA expression in both rat strains. Both rMCP-1 and rMCP-5 mRNA expressions were positively correlated with progressive diastolic dysfunction (increasing the ratio of early mitral inflow velocity-to-early mitral annular velocity, E/e') and expanding chamber dimensions or increasing left ventricular internal diameter end diastole. These data show rMCP-1 and rMCP-5 as the Ang II forming chymase isoforms participating in the loss of normal cardiac function due to OVX in rodents.

Glomerular Injury Is Exacerbated in Lupus-Prone MRL/lpr Mice Treated with a Protease-Activated Receptor 2 Antagonist.

Systemic lupus erythematosus (SLE) is characterized by the production of autoantibodies, which causes multi-organ injury such as lupus nephritis. SLE is associated with hypercoagulability. Activated coagulation factors such as tissue factor and VIIa complex and factor Xa activate protease-activated receptor 2 (PAR2). PAR2 promotes cytokine production through mitogen-activated protein kinase or nuclear factor kappa B signaling, and previous reports demonstrated that inhibition of PAR2 alleviated kidney injuries such as diabetic kidney disease and renal fibrosis in animal models. However, the involvement of PAR2 in the pathogenesis of SLE remains unclear. We therefore administered a selective PAR2 peptide antagonist, FSLLRY-NH2, to SLE-prone 4-month-old MRL-Faslpr mice for 4 weeks. Treatment with FSLLRY-NH2 caused the significant increases in the glomerular mesangial proliferation, glomerular deposition of both immunoglobulin G and complement factor C3d, and glomerular infiltration of Mac2-positive macrophages and CD3-positive T cells, compared with MRL-Faslpr mice treated with saline. In addition, the treatment with the PAR2 antagonist increased renal expression levels of tumor necrosis factor-α (Tnfa) and monocyte chemoattractant protein 1 (Mcp1) mRNA. Collectively, these results suggest that inhibition of PAR2 may increase the severity of inflammation in lupus nephritis; namely, opposite to previous observations, PAR2 has anti-inflammatory properties. We propose that activation of PAR2 could serve as a potential therapeutic option for patients with SLE.

Green tea extract inhibits early oncogenic responses in mice with nonalcoholic steatohepatitis.

Nonalcoholic steatohepatitis (NASH) increases hepatocellular carcinoma (HCC) risk. We hypothesized that the hepatoprotective anti-inflammatory benefits of catechin-rich green tea extract (GTE) would protect against HCC progression by inhibiting NASH-associated liver injury and pro-oncogenic responses. We used an HCC model in high-fat (HF)-fed mice that mimics early oncogenic events during NASH without inducing tumorigenesis and premature mortality. Male C57BL/6J mice (4-weeks old) were fed a HF diet containing GTE at 0% or 2%. Mice were administered saline or diethylnitrosamine (DEN; 60 mg kg-1, i.p.) at 5-weeks and 7-weeks of age. NASH, inflammation, fibrosis, and oncogenic responses were assessed at 25-weeks of age. Saline-treated mice showed prominent histopathological signs of steatosis and hepatocellular ballooning. Although DEN did not impact adiposity, steatosis, ballooning and hepatic lipid accumulation, these parameters were attenuated by GTE regardless of DEN. Hepatic lipid peroxidation and fibrosis that were increased by DEN were attenuated by GTE. Hepatic TLR4, MCP1 and TNFα mRNA levels were unaffected by DEN, whereas iNOS was increased by DEN. These transcripts were lowered by GTE. GTE attenuated the frequency of PCNA+ hepatocytes and mRNA expression of cyclin D1, MIB1 and Ki-67 that were otherwise increased by DEN. GTE increase APAF1 mRNA that was otherwise lowered by DEN. Relative to saline-treated mice, DEN increased mRNA levels of oncostatin M, gp130, c-Fos, c-Myc and survivin; each was lowered by GTE in DEN-treated mice. These findings indicate that GTE may protect against hepatic oncogenesis by limiting early steps in the carcinogenic cascade related to NASH-associated HCC.

Leukocyte cell-derived chemotaxin 2 inhibits development of atherosclerosis in mice.

Leukocyte cell-derived chemotaxin 2 (LECT2), a multifunctional hepatokine, is involved in many pathological conditions. However, its role in atherosclerosis remains undefined. In this study, we administered vehicle or LECT2 to male Apoe-/- mice fed a Western diet for 15 weeks. Atherosclerotic lesions were visualized and quantified with Oil-red O and hematoxylin staining. The mRNA expression levels of MCP-1, MMP-1, IL-8, IL-1β, and TNF-α were analyzed by quantitative real-time polymerase chain reaction. Serum TNF-α, IL-1β, IL-8, MCP-1, and MMP-1 concentrations were measured by enzyme-linked immunosorbent assay. CD68, CD31, and α-SMA, markers of macrophages, endothelial cells, and smooth muscle cells, respectively, were detected by immunostaining. Results showed that LECT2 reduced total cholesterol and low-density lipoprotein concentrations in serum and inhibited the development of atherosclerotic lesions, accompanied by reductions in inflammatory cytokines and lower MCP-1, MMP-1, TNF-α, IL-8, and IL-1β mRNA abundance. Furthermore, LECT2 decreased CD68, but increased α-SMA in atherosclerotic lesions, suggesting an increase in smooth muscle cells and reduction in macrophages. In summary, LECT2 inhibited the development of atherosclerosis in mice, accompanied by reduced serum total cholesterol concentration and lower inflammatory responses.

Higher Monocyte Chemoattractant Protein-1 Levels in Myelofibrosis Are Sustained By the rs1024611 Single Nucleotide Polymorphism and Correlate with Disease Subtype and Severity

Introduction: Host genetic variations have an essential role in the mutational landscape of Philadelphia-negative myeloproliferative neoplasm (MPNs), with JAK2 46/1 and TERT rs2736100 polymorphisms predisposing to disease onset (Tapper W et al, Nat Commun. 2015). However, the contribution of inherited factors in disease phenotype and evolution is poorly characterized. We recently demonstrated that the -2518 A/G SNP of the Monocyte Chemoattractant Protein-1 (MCP-1, rs1024611) is an inherited host genetic factor associated with secondary myelofibrosis (sMF) and a biomarker of disease severity in MF, correlating with adverse hematologic characteristics at the time of diagnosis, such as higher IPSS risk category (Masselli E et al, Leukemia 2018). Here we aimed to: i) provide a correlation between MF patients' genetic readout, chemokine expression/production and hematopoietic progenitor differentiation, ii) correlate MCP-1 levels with disease subtype and severity.Methods: 16 MF patients were genotyped for MCP-1 SNP by TaqMan Predesigned SNP Genotyping Assays and added to our previously reported dataset (Masselli E et al, Leukemia 2018), reaching 81 MF (20 prePMF, 36 overtPMF and 25 sMF). Samples from 15 therapy-naïve MF were dedicated to in vitro-experiments. Eleven healthy subjects and 4 apheresis bags were utilized as controls (CTRL). MF were stratified according to their rs1024611 genotype in A/A (wild types), A/G and G/G (polymorphics). Peripheral blood mononuclear cells (MNCs) were isolated by Ficoll-Hypaque gradient, in part pelleted (resting, T0) and in part seeded in RPMI-1640 medium and activated with 1.1 ng/ml of IL-1β for 20h (T1). CD34+-cells were purified from MF peripheral blood and from apheresis by immunomagnetic selection and differentiated toward the MK lineage as described in Masselli E et al, Leukemia 2015, up to 14 days. MK differentiation was assessed by CD41-flow cytometric expression. MCP-1 levels were evaluated by real-time PCR and western blot.Results: We confirmed, in a cohort of 81 MF patients, that polymorphic subjects were significantly more frequent in sMF vs. PMF (17/25, 68% vs. 21/56, 37.5%, respectively, P=.011, Fig.1A). Of note, sMF was significantly more frequent in A/G and G/G individuals than either prePMF (6/20, 30%, P=.011) or overtPMF (15/36, 41.7%, P=.034, Fig.1B). In overall MF patients, a higher frequency of allele-G carriers was also confirmed in IPSS int-2/high vs. low/int-1 risk group (17/25, 68% vs. 19/51, 37.3%, respectively, P=.011, Fig.1C - all comparisons made by Χ2 test).We proved that MF MNCs significantly over-expressed MCP-1 mRNA and protein as compared to CTRL MNCs at basal state (P=.04 and P=.006 by t-test, respectively, Fig.1D-E), consistently with reports from Tefferi et al. on serum ELISA (Tefferi A et al, JCO 2011). Of note, basal MCP-1 mRNA levels in MF correlated with genotypes, with polymorphic patients displaying significantly higher transcript levels vs. wild types (~20-times higher 2-ΔΔCT, P=.018 by t-test). When MF MNCs were stimulated ex-vivo with IL-1β, a dose-dependent effect of the SNP on MCP-1 expression was observed, with A/G patients displaying >20-times higher and G/G patients showing >60-times-higher fold-increase in MCP-1 expression as compared to wild types (P<.05 G/G vs. A/A by ANOVA and Dunnett test, Fig.1F). sMF patients, that we proved to be enriched in polymorphic genotypes as compared to overall PMF, prePMF and overtPMF patients, significantly over-expressed MCP-1 as compared to PMF (P<.0001 by t-test, Fig. 1G) and prePMF (P<.05 by Anova and Dunnett test, Fig. 1H). Similarly, IPSS intermediate-2/high risk MF patients, also enriched in the G allele, showed significantly higher MCP-1 mRNA levels vs. both IPSS low and intermediate-1 (P<.05 by ANOVA and Dunnett test, Fig. 1I). Finally, we demonstrated that polymorphic CD34+-cells displayed impaired megakaryocytic differentiation, indicated by a significantly lower number of CD41+-cells obtained in culture as compared to A/A (P=.04 by t-test, Fig.1L).Conclusions: Our data proved a dose-dependent effect of the rs1024611 SNP on MCP-1 production in MF and establish a correlation between patients' genetic readout and chemokine levels. These results suggest that MF patients harboring the G allele - and thus producing more MCP-1 - are genetically prone to a higher inflammatory burden, to display a more severe disease and abnormal MK differentiation. [Display omitted] DisclosuresAversa:Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees; Merck: Honoraria; Astellas: Honoraria; Basilea: Honoraria, Membership on an entity's Board of Directors or advisory committees; Pfizer: Honoraria, Membership on an entity's Board of Directors or advisory committees.

Leptin decreases circulating inflammatory IL-6 and MCP-1 in mice.

Leptin influences inflammation and immune response. Dose-dependent effects of leptin on biomarkers of inflammation have not been studied in vivo, so far. Leptin-deficient low-density lipoprotein receptor (LDLR) knockout (LDLR-/- ;ob/ob) female mice were treated with three different leptin doses or saline for 12 weeks. The effect of leptin on plasma interleukin (IL)-6 and monocyte chemoattractant protein (MCP)-1 concentrations and Il-6 and Mcp-1 mRNA expression in vivo were assessed. Macrophage infiltration in epididymal adipose tissue (epiAT) after leptin treatment was determined by quantitative immunohistochemical analysis. Aortic root atherosclerotic lesions were analyzed by oil red O staining. Mean plasma IL-6 and MCP-1 decreased significantly in the 3.0 mg/kg BW/day group as compared to control mice (both P < 0.01). Messenger RNA expression of Il-6 and Mcp-1 was significantly down-regulated by leptin treatment in different adipose tissues in vivo. Characteristic crown-like structures formed by adipose tissue macrophages were significantly reduced by leptin treatment in epiAT. Recombinant leptin dose-dependently diminished plaque area in the aortic root. Leptin administration within the subphysiological to physiological range diminishes circulating pro-inflammatory IL-6 and MCP-1. Reduction of Il-6 and Mcp-1 gene expression in adipose tissue, as well as decreased adipose tissue macrophage infiltration might contribute. © 2018 BioFactors, 45(1):43-48, 2019.

Early and Late Protective Effect of Bone Marrow Mononuclear Cell Transplantation on Radiation-Induced Vascular Dysfunction and Skin Lesions

Skin lesions caused by accidental exposure to radiation or by radiotherapy are a major clinical challenge. We evaluated the effect of bone marrow mononuclear cells (BMMNC) on collagen remodeling and vascular function in radiation-induced skin lesions in the acute and late phases in mice. We studied the effect of BMMNC transplantation in a mouse model of cutaneous radiation injury combining local skin gamma-irradiation and biopsy punch wound. Mice were first irradiated, punched and then BMMNC were intramuscularly administered. Seven days after injury, BMMNC promoted wound healing by (i) increasing re-epithelialization, tissue collagen density and mRNA levels of collagens 1A1, 1A2, and 3A1, and (ii) inhibiting the radiation-induced vascular activation and limiting interactions between leukocytes and the vascular endothelium compared with control. Importantly, BMMNC did not amplify the inflammatory response despite the infiltration of neutrophils and macrophages associated with the expression of IL-6 and MCP-1 mRNAs in the tissue. Remarkably, the beneficial effects of BMMNC therapy on matrix remodeling were maintained for 2 months. Furthermore, BMMNC injection restored vascular function in skin tissue by increasing vascular density and vascular permeability. This therapeutic strategy based on BMMNC injection protects against radiation-induced skin lesions by preventing vascular dysfunction and unfavorable remodeling in the acute and late phases.

Celastrol ameliorates inflammatory pain and modulates HMGB1/NF-κB signaling pathway in dorsal root ganglion

Evidences reported that high mobility group box 1 (HMGB1) played a pivotal role in the modulation of chronic inflammatory pain. Celastrol, a bioactive component extracted from Tripterygium wilfordii Hook, possesses anti-inflammatory activity, but the underlying mechanism remains to be fully clarified. We aim to investigate whether HMGB1 in dorsal root ganglion (DRG) participates in the effect of celastrol on inflammatory pain. Complete Freund’s adjuvant (CFA)-induced inflammatory pain rat model was used. Paw withdrawal latency (PWL) was detected to evaluate the effects of celastrol on CFA-evoked inflammatory pain. After application of celastrol (1mg/kg, i.p.) on day 1, 3, 7 and 14 post-CFA injection, the expression levels of HMGB1, NF-κB, some proinflammatory markers, GFAP and CD11b in DRG were determined by qRT-PCR and western blot analysis. These results showed that celastrol significantly suppressed HMGB1, NF-κB and IL-1β mRNA and protein expression in DRG and alleviated CFA-evoked thermal hyperalgesia. Furthermore, celastrol obviously inhibited COX-2 protein expression and down-regulated IL-6, IL-17, TNF-α, MCP-1, GFAP and CD11b mRNA levels in DRG of CFA rats. Collectively, the present study firstly provide evidences of the anti-inflammatory effect of celastrol via suppressing CFA-induced the activation of HMGB1/NF-κB signaling pathway in DRG, which maybe a potential therapeutic target for celastrol alleviating inflammatory pain.

Dietary saturated fatty acid type impacts obesity-induced metabolic dysfunction and plasma lipidomic signatures in mice

Saturated fatty acid (SFA) intake is associated with obesity, insulin resistance, and hepatic steatosis, but scant work examines the impact of SFA type upon these outcomes. We tested the hypothesis that an obesogenic diet prepared with medium chain SFA (MCSFA), mostly as lauric acid-derived from coconut oil, reduces obesity-induced outcomes compared to obesogenic diets prepared with increasing amounts long chain SFA (LCSFA), primarily palmitic acid. Mice were fed (16 weeks) a control, low fat diet or obesogenic diets prepared with differing content of MCSFA or LCSFA in which polyunsaturated and monounsaturated fatty acids (PUFA; MUFA) were kept constant. Inclusion of MCSFA in an obesogenic diet prevented hepatic lipid accumulation and lowered indices of insulin resistance. Obesogenic diets reduced hepatic levels of de novo lipogenesis proteins (SCD1 and FASN) but elevated the adipose levels of mRNA for the pro-inflammatory markers Mcp-1 and Tnfα. Lipidomic analysis of plasma indicated that MCSFA intake resulted in a different lipidomic signature than LCSFA intake, prevented elevation of pro-inflammatory ceramides, but elevated concentrations of some lipids associated with elevated cardiovascular disease risk. Intake of the obesogenic diets in an SFA-type dependent manner elevated plasma concentrations of several phosphatidylcholine (PC) lipids having the long chain PUFA (LCPUFA) arachidonic acid (ARA) and docosahexaenoic acid (DHA), altered phospholipid ethers, and changed the triacylglyceryl environments of these LCPUFA. Our data indicate that (1) MCSFA reduce the severity of some obesogenic co-morbidities, (2) SFA-type modulates lipidomic signatures associated with cardiovascular disease and diabetes, and (3) dietary SFA type impacts LCPUFA metabolism.

Inflammatory cytokine oncostatin M induces endothelial activation in macro- and microvascular endothelial cells and in APOE*3Leiden.CETP mice.

AimsEndothelial activation is involved in many chronic inflammatory diseases, such as atherosclerosis, and is often initiated by cytokines. Oncostatin M (OSM) is a relatively unknown cytokine that has been suggested to play a role in both endothelial activation and atherosclerosis. We comprehensively investigated the effect of OSM on endothelial cell activation from different vascular beds and in APOE*3Leiden.CETP mice.Methods and resultsHuman umbilical vein endothelial cells, human aortic endothelial cells and human microvascular endothelial cells cultured in the presence of OSM express elevated MCP-1, IL-6 and ICAM-1 mRNA levels. Human umbilical vein endothelial cells and human aortic endothelial cells additionally expressed increased VCAM-1 and E-selectin mRNA levels. Moreover, ICAM-1 membrane expression is increased as well as MCP-1, IL-6 and E-selectin protein release. A marked increase was observed in STAT1 and STAT3 phosphorylation indicating that the JAK/STAT pathway is involved in OSM signaling. OSM signals through the LIF receptor alfa (LIFR) and the OSM receptor (OSMR). siRNA knockdown of the LIFR and the OSMR revealed that simultaneous knockdown is necessary to significantly reduce MCP-1 and IL-6 secretion, VCAM-1 and E-selectin shedding and STAT1 and STAT3 phosphorylation after OSM stimulation. Moreover, OSM administration to APOE*3Leiden.CETP mice enhances plasma E-selectin levels and increases ICAM-1 expression and monocyte adhesion in the aortic root area. Furthermore, Il-6 mRNA expression was elevated in the aorta of OSM treated mice.ConclusionOSM induces endothelial activation in vitro in endothelial cells from different vascular beds through activation of the JAK/STAT cascade and in vivo in APOE*3Leiden.CETP mice. Since endothelial activation is an initial step in atherosclerosis development, OSM may play a role in the initiation of atherosclerotic lesion formation.

RA10.02: A NOVEL ROLE FOR THE COMPLEMENT CASCADE IN CHEMORADIATION THERAPY RESISTANT OESOPHAGEAL ADENOCARCINOMA

Abstract Background Resistance to chemoradiation therapy (CRT) in oesophageal adenocarcinoma (OAC) is an important clinical challenge. Elucidating underlying mechanisms of treatment resistance is crucial to improving survival rates. Methods OAC tumour biopsies were collected prior to neoadjuvant CRT. Tumour conditioned media was generated by culturing human explants for 24 h. Response to treatment was determined pathologically using the Mandard Grading System. C3, CFB and MCP-1 mRNA expression was assessed by qPCR. Secreted C3, C3a and MCP-1 were measured by ELISA. An isogenic model of radioresistant OAC was established by chronically irradiating OE33 cells with clinically-relevant doses of 2 Gy X-ray radiation. C5aR and C3aR expression was determined by flow cytometry. Results We demonstrate, for the first time, that the central factor of the complement cascade, complement component 3 (C3), is expressed in OAC tumours and is increased in pre-treatment OAC biopsies from patients (n = 13) who have a subsequent poor response to neoadjuvant CRT (P &lt; 0.05). In addition, C3 is secreted from ex vivo human OAC tumour explants (n = 13) and correlates with levels of the monocyte chemoattractant MCP-1 (P &lt; 0.008) and complement factor B (CFB) a component of the alternative pathway of complement activation (P &lt; 0.0001). In vitro, radioresistant OE33 R cells had increased mRNA levels of C3 (P &lt; 0.01), CFB (P &lt; 0.05) and MCP-1 (P &lt; 0.05) compared to radiosensitive OE33 P cells. OEE3 R cells expressed increased levels of secreted C3 and the anaphylatoxin C3a, compared to radiosensitive OE33P cells (both P &lt; 0.001). Furthermore, we demonstrate for the first time that the anaphylatoxin receptor C5aR is expressed by OAC cells, suggesting that OAC cells can respond to complement anaphylatoxins. Conclusion This study highlights, for the first time, a novel role for the complement cascade in the resistance of OAC to CRT and highlights C3 as a novel predictive marker of response to CRT in OAC. Disclosure All authors have declared no conflicts of interest.

MiR-374a Regulates Inflammatory Response in Diabetic Nephropathy by Targeting MCP-1 Expression.

The microRNA (mir)-374a has been implicated in several types of human cancer; however, its role in diabetic nephropathy (DN) remains unclear. Monocyte chemoattractant protein (MCP)-1 is a chemokine that recruits macrophages to inflammatory sites and is important for the development and progression of DN. However, the relationship between miR-374a and MCP-1 in DN is unknown. We addressed this in the present study by examining the expression of these factors in kidney tissue samples from DN patients and through loss- and gain-of-function experiments using HK2 human renal tubular epithelial cells. We found that miR-374a was downregulated whereas MCP-1 was upregulated in DN tissue. A bioinformatics analysis revealed that MCP-1 is a putative target of miR-374a. To confirm this relationship, HK2 cells treated with normal glucose (5.6 mmol/l D-glucose), high glucose (HG) (30 mmol/l D-glucose), or high osmotic pressure solution (5.6 mmol/l D-glucose + 24.4 mmol/l D-mannitol) were transfected with miR-374a mimic or inhibitor. miR-374a mimic reduced MCP-1 mRNA expression and migration of co-cultured U937 cells, whereas miR-374a inhibition had the opposite effects. Additionally, interleukin-6 and -18 and tumor necrosis factor-α levels were downregulated by transfection of miR-374a mimic. On the other hand, MCP-1 overexpression reversed the inhibitory effects of miR-374a in HK2 cells. Thus, miR-374a suppresses the inflammatory response in DN through negative regulation of MCP-1 expression. These findings suggest that therapeutic strategies that target the miR-374a/MCP-1 axis can be an effective treatment for DN.

Canagliflozin attenuates the progression of atherosclerosis and inflammation process in APOE knockout mice

BackgroundSodium glucose co-transporter2 inhibitors reduce the incidence of cardiovascular events in patients with type 2 diabetes mellitus based on the results of recent cardiovascular outcome studies. Herein, we investigated the effects of long-term treatment with canagliflozin on biochemical and immunohistochemical markers related to atherosclerosis and atherosclerosis development in the aorta of apolipoprotein E knockout (Apo-E(−/−)) mice.MethodsAt the age of 5 weeks, mice were switched from normal to a high-fat diet. After 5 weeks, Apo-E(−/−) mice were divided into control-group (6 mice) treated with 0.5% hydroxypropyl methylcellulose and Cana-group (7 mice) treated with canagliflozin (10 mg/kg per day) per os. After 5 weeks of intervention, animals were sacrificed, and heart and aorta were removed. Sections stained with hematoxylin–eosin (H&E) were used for histomorphometry whereas Masson’s stained tissues were used to quantify the collagen content. Immunohistochemistry to assess MCP-1, CD68, a-smooth muscle actin, MMP-2, MMP-9, TIMP-1 and TIMP-2 expression was carried out and q-PCR experiments were performed to quantify mRNA expression.ResultsCanagliflozin-group mice had lower total-cholesterol, triglycerides and glucose levels (P < 0.01), while heart rate was significantly lower (P < 0.05). Histomorphometry revealed that one in seven Cana-group mice versus four in six control mice developed atheromatosis, while aortic root plaque was significantly less, and collagen was 1.6 times more intense in canagliflozin-group suggesting increased plaque stability. Immunohistochemistry revealed that MCP-1 was significantly less expressed (P < 0.05) in the aortic root of canagliflozin-group while reduced expression of a-actin and CD68 was not reaching significance (P = 0.15). VCAM-1 and MCP-1 mRNA levels were lower (P = 0.02 and P = 0.07, respectively), while TIMP-1/MMP-2 ratio expression was higher in canagliflozin-group approaching statistical significance (P = 0.07).ConclusionsCanagliflozin attenuates the progression of atherosclerosis, reducing (1) hyperlipidemia and hyperglycemia, and (2) inflammatory process, by lowering the expression of inflammatory molecules such as MCP-1 and VCAM-1. Moreover, canagliflozin was found to increase the atherosclerotic plaque stability via increasing TIMP-1/MMP-2 ratio expression.

Mechanisms of macrophages accumulation in the process of immobilized-induced muscle contracture in rats

Skeletal muscle fibrosis is the main pathology of immobilized-induced muscle contracture. Our previous studies revealed that upregulation of interleukin-1β/transforming growth factor-β1 associated with macrophages accumulation was related to the development of skeletal muscle fibrosis. However, the mechanisms underlying the increase in the number of macrophages in the immobilized soleus muscle are unclear. In this study, we investigated the mechanisms of macrophages accumulation in the immobilized soleus muscle of rat ankle- joint contracture models. Rats were divided into immobilization and control groups. In the immobilization group, both ankle joints of each rats were immobilized in full plantar flexion with plaster casts for 1 and 2 weeks. To assess alterations of macrophages, the number of CD11b-positive cells and the monocyte chemotactic protein (MCP)-1 mRNA expression were measured. Additionally, to assess alterations of the myocyte, the number of myonuclei and TUNEL-positive cells, cross-sectional area (CSA) of myofibers, and the myonuclear domain size were measured. Immobilization resulted in a significant increase in the number of CD11b-positive cells and the MCP-1 mRNA expression at 1 and 2 weeks. The number of myonuclei and the CSA of myofibers were significantly decreased in the immobilization group compared to the control group at 1 and 2 weeks. Only the CSA of myofibers significantly decreased, depending on the immobilization period. The myonuclear domain size was significantly lower in the immobilization group at 2 weeks compared to the control group. TUNEL-positive cells were significantly increased in the immobilization group compared to the control group at 1 and 2 weeks. These results indicated that joint immobilization after 1 week induced macrophages accumulation and reduced the number of myonuclei associated with myocyte apoptosis, which caused a decrease in the CSA of myofibers. These changes suggest that immobilized-induced muscle fiber atrophy following myocyte apoptosis induce macrophage accumulation.

Lysyl oxidase like-2 contributes to renal fibrosis in Col4α3/Alport mice

Lysyl oxidase like-2 (LOXL2) is an amine oxidase with both intracellular and extracellular functions. Extracellularly, LOXL2 promotes collagen and elastin crosslinking, whereas intracellularly, LOXL2 has been reported to modify histone H3, stabilize SNAIL, and reduce cell polarity. Although LOXL2 promotes liver and lung fibrosis, little is known regarding its role in renal fibrosis. Here we determine whether LOXL2 influences kidney disease in COL4A3 (-/-) Alport mice. These mice were treated with a small molecule inhibitor selective for LOXL2 or with vehicle and assessed for glomerular sclerosis and fibrosis, albuminuria, blood urea nitrogen, lifespan, pro-fibrotic gene expression and ultrastructure of the glomerular basement membrane. Laminin α2 deposition in the glomerular basement membrane and mesangial filopodial invasion of the glomerular capillaries were also assessed. LOXL2 inhibition significantly reduced interstitial fibrosis and mRNA expression of MMP-2, MMP-9, TGF-β1, and TNF-α. LOXL2 inhibitor treatment also reduced glomerulosclerosis, expression of MMP-10, MMP-12, and MCP-1 mRNA in glomeruli, and decreased albuminuria and blood urea nitrogen. Mesangial filopodial invasion of the capillary tufts was blunted, as was laminin α2 deposition in the glomerular basement membrane, and glomerular basement membrane ultrastructure was normalized. There was no effect on lifespan. Thus, LOXL2 plays an important role in promoting both glomerular and interstitial pathogenesis associated with Alport syndrome in mice. Other etiologies of chronic kidney disease are implicated with our observations.