scholarly journals RAGE Mediates Cholesterol Efflux Impairment in Macrophages Caused by Human Advanced Glycated Albumin

2020 ◽  
Vol 21 (19) ◽  
pp. 7265
Author(s):  
Adriana Machado-Lima ◽  
Raquel López-Díez ◽  
Rodrigo Tallada Iborra ◽  
Raphael de Souza Pinto ◽  
Gurdip Daffu ◽  
...  

We addressed the involvement of the receptor for advanced glycation end products (RAGE) in the impairment of the cellular cholesterol efflux elicited by glycated albumin. Albumin was isolated from type 1 (DM1) and type 2 (DM2) diabetes mellitus (HbA1c > 9%) and non-DM subjects (C). Moreover, albumin was glycated in vitro (AGE-albumin). Macrophages from Ager null and wild-type (WT) mice, or THP-1 transfected with siRNA-AGER, were treated with C, DM1, DM2, non-glycated or AGE-albumin. The cholesterol efflux was reduced in WT cells exposed to DM1 or DM2 albumin as compared to C, and the intracellular lipid content was increased. These events were not observed in Ager null cells, in which the cholesterol efflux and lipid staining were, respectively, higher and lower when compared to WT cells. In WT, Ager, Nox4 and Nfkb1, mRNA increased and Scd1 and Abcg1 diminished after treatment with DM1 and DM2 albumin. In Ager null cells treated with DM-albumin, Nox4, Scd1 and Nfkb1 were reduced and Jak2 and Abcg1 increased. In AGER-silenced THP-1, NOX4 and SCD1 mRNA were reduced and JAK2 and ABCG1 were increased even after treatment with AGE or DM-albumin. RAGE mediates the deleterious effects of AGE-albumin in macrophage cholesterol efflux.

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Adriana Machado-Lima ◽  
Erika R Oliveira ◽  
Rodrigo T Iborra ◽  
Gabriela Castilho ◽  
Edna R Nakandakare ◽  
...  

Advanced glycation end products (AGE) are elevated in diabetes mellitus (DM) and predict the development of atherosclerosis. In vitro produced AGE-albumin induces oxidative stress that is linked to the reduction in ABCA-1 levels and cholesterol efflux mediated by apo A-I and HDL-subfractions, leading to macrophage cholesterol accumulation. We characterized the glycation level/profile of human serum albumin (HSA) isolated by fast protein liquid chromatography from poorly controlled type 1 (DM1) and type 2 (DM2) diabetes mellitus patients (HbA1c > 8%) in comparison to control (C) individuals, and how these AGE-albumin can interfere in macrophage lipid accumulation. The glycation level of HSA from C, DM1 and DM2 was analyzed by MALDI mass spectrometry and was similar between DM1 and DM2-HSA. An increased mean mass was observed in DM1-HSA (68,544 ± 192 Da; n=6) and DM2-HSA (68,547 ± 132 Da; n=6) compared to C-HSA (67,846 ± 301 Da; n=6), reflecting the condensation of at least 8 and 5 units of glucose, respectively. The tryptic digestion of C-HSA generated a number of peptide species higher than those originated from DM1 and DM2-HSA. Macrophages isolated from peritoneal wild-type mice were treated for 18 h with C, DM1 or DM2-HSA in order to measure the 14C-cholesterol efflux and the mRNA expression of NOX-4 (NADPHoxidase4), ABCA-1 (Abca1) and ABCG-1 (Abcg1). Data were compared by one-way ANOVA and Dunnet′s post test. In comparison to cells treated with C-HSA the expression of NADPHoxidase4 (p<0.05; n=3) mRNA was increased after cell treatment with DM1 (3.2x) and DM2-HSA (0.7x), confirming oxidative stress. Abcg1 mRNA was reduced by DM2-HSA (26%; p<0.05; n=3); Abca1 mRNA was unchanged but ABCA-1 protein content was greatly reduced (82 and 25%, respectively in DM1 and DM2-HAS; p<0.05; n=12). The % of apo A-I mediated cholesterol efflux was impaired in DM1 (1.3 ± 0.3) and DM2-HSA-treated cells (2.4 ± 0.5) as compared to C-HSA (4.4 ± 0.5; n= 5; p<0.05). The level of advanced glycation that takes place in vivo was similar between DM1 and DM2-HSA and induced macrophage oxidative stress and impairment in cholesterol efflux that may contribute to atherogenesis in DM. Funding: FAPESP, Brazil (2012/19112-0)


Nutrients ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 3633
Author(s):  
Carlos André Minanni ◽  
Adriana Machado-Lima ◽  
Rodrigo Tallada Iborra ◽  
Lígia Shimabukuro Okuda ◽  
Raphael de Souza de Souza Pinto ◽  
...  

Advanced glycated albumin (AGE-albumin) impairs cholesterol efflux and contributes to inflammation in macrophages. The current study evaluated: (1) the persistence of the deleterious effect of AGE-albumin in cholesterol efflux and in inflammation, and (2) how metabolic control in diabetes mellitus (DM) contributes to attenuate the deleterious role of AGE-albumin in macrophage cholesterol homeostasis. Methods: AGE-albumin was produced in vitro or isolated from uncontrolled DM subjects’ serum before (bGC) and after improved glycemic control (aGC). Albumin samples were incubated with bone marrow-derived macrophages and 14C-cholesterol efflux or LPS- induced cytokine secretion were determined immediately, or after cell resting in culture media alone. The ABCA-1 degradation rate was determined after cell incubation with cycloheximide, and ABCA1 protein level by immunoblot. Oil Red O staining was used to assess intracellular lipid accumulation. Results: A persistent effect of AGE-albumin was observed in macrophages in terms of the secretion of inflammatory cytokines and reduced cholesterol efflux. HDL-mediated 14C-cholesterol efflux was at least two times higher in macrophages treated with aCG-albumin as compared to bGC-albumin, and intracellular lipid content was significantly reduced in aGC-albumin-treated cells. As compared to bGC-albumin, the ABCA-1 protein content in whole cell bulk was 94% higher in aCG-albumin. A 20% increased ABCA-1 decay rate was observed in macrophages treated with albumin from poorly controlled DM. AGE-albumin has a persistent deleterious effect on macrophage lipid homeostasis and inflammation. The reduction of AGEs in albumin ameliorates cholesterol efflux.


2019 ◽  
Vol 93 (13) ◽  
Author(s):  
Satoshi Hirose ◽  
Shaohui Wang ◽  
Kati Tormanen ◽  
Yizhou Wang ◽  
Jie Tang ◽  
...  

ABSTRACTInnate lymphoid cells (ILCs) play important roles in host defense and inflammation. They are classified into three distinct groups based on their cytokine and chemokine secretion patterns and transcriptome profiles. Here, we show that ILCs isolated from mice can be infected with herpes simplex virus 1 (HSV-1) but that subsequent replication of the virus is compromised. After infection, type 2 ILCs expressed significantly higher levels of granulocyte colony-stimulating factor (G-CSF), interleukin 1α (IL-1α), IL-6, IL-9, RANTES, tumor necrosis factor alpha (TNF-α), CXCL1, CXCL2, CXCL10, CCL3, and CCL4 than infected type 1 or type 3 ILCs. Transcriptome-sequencing (RNA-seq) analysis of the ILCs 24 h after HSV-1 infection revealed that 77 herpesvirus genes were detected in the infected type 3 ILCs, whereas only 11 herpesvirus genes were detected in infected type 1 ILCs and 27 in infected type 2 ILCs. Compared with uninfected cells, significant upregulation of over 4,000 genes was seen in the HSV-1-infected type 3 ILCs, whereas 414 were upregulated in the infected type 1 ILCs and 128 in the infected type 2 ILCs. In contrast, in all three cell types, only a limited number of genes were significantly downregulated. Type 1, type 2, and type 3 ILC-deficient mice were used to gain insights into the effects of the ILCs on the outcome of ocular HSV-1 infection. No significant differences were found on comparison with similarly infected wild-type mice or on comparison of the three strains of deficient mice in terms of virus replication in the eyes, levels of corneal scarring, latency-reactivation in the trigeminal ganglia, or T-cell exhaustion. Although there were no significant differences in the survival rates of infected ILC-deficient mice and wild-type mice, there was significantly reduced survival of the infected type 1 or type 3 ILC-deficient mice compared with type 2 ILC-deficient mice. Adoptive transfer of wild-type T cells did not alter survival or any other parameters tested in the infected mice. Our results indicate that type 1, 2, and 3 ILCs respond differently to HSV-1 infectionin vitroand that the absence of type 1 or type 3, but not type 2, ILCs affects the survival of ocularly infected mice.IMPORTANCEIn this study, we investigated for the first time what roles, if any, innate lymphoid cells (ILCs) play in HSV-1 infection. Analysis of isolated ILCsin vitrorevealed that all three subtypes could be infected with HSV-1 but that they were resistant to replication. The expression profiles of HSV-1-induced cytokines/chemokines and cellular and viral genes differed among the infected type 1, 2, and 3 ILCsin vitro. While ILCs play no role or a redundant role in the outcomes of latency-reactivation in infected mice, absence of type 1 and type 3, but not type 2, ILCs affects the survival of infected mice.


Foods ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 514
Author(s):  
Hilal Demirkesen-Bicak ◽  
Muhammet Arici ◽  
Mustafa Yaman ◽  
Salih Karasu ◽  
Osman Sagdic

This study aimed to evaluate the influence of sourdough fermentation on the estimated glycemic index (eGI), in vitro starch digestibility, and textural and sensory properties of eight experimentally prepared sourdough breads. Wheat and whole wheat flour bread samples were produced under different fermentation conditions (25 °C and 30 °C) and fermentation methods (type-1 and type-2). In type-1 fermentation, sourdough was obtained via spontaneous fermentation. Indigenous strains (Lactobacillus brevis ELB99, Lactiplantibacillus plantarum ELB75, and Saccharomyces cerevisiae TGM55) were used for type-2 fermentation. Fermentation type and temperature significantly affected eGI, the hydrolysis index (HI), the starch fraction, and the textural properties of the samples (p < 0.05). The resistant starch (RS) content increased after fermentation, while rapidly digestible starch (RDS), HI, and eGI decreased. RS values were significantly higher in type-2 than in type-1 at the same temperature for both flour types (p < 0.05). At 25 °C, RS values were higher in both fermentation types. In the white flour samples, eGI values were in the range of 60.8–78.94 and 62.10–78.94 for type-1 and type-2, respectively. The effect of fermentation type on eGI was insignificant (p < 0.05). In the whole flour samples, fermentation type and temperature significantly affected eGI (p < 0.05). The greatest eGI decreases were in whole wheat sourdough bread at 30 °C using type-2 (29.74%). The 30 °C and type-2 samples showed lower hardness and higher specific volume. This study suggests that fermentation type and temperature could affect the eGI and the textural and sensory properties of sourdough bread, and these factors should be considered during bread production. The findings also support the consumption of wheat and whole wheat breads produced by type-2 fermentation due to higher RS and slowly digestible starch (SDS) and lower RDS and eGI values.


2019 ◽  
Vol 476 (6) ◽  
pp. 991-1003 ◽  
Author(s):  
Vijaykumar Pillalamarri ◽  
Tarun Arya ◽  
Neshatul Haque ◽  
Sandeep Chowdary Bala ◽  
Anil Kumar Marapaka ◽  
...  

Abstract Natural product ovalicin and its synthetic derivative TNP-470 have been extensively studied for their antiangiogenic property, and the later reached phase 3 clinical trials. They covalently modify the conserved histidine in Type 2 methionine aminopeptidases (MetAPs) at nanomolar concentrations. Even though a similar mechanism is possible in Type 1 human MetAP, it is inhibited only at millimolar concentration. In this study, we have discovered two Type 1 wild-type MetAPs (Streptococcus pneumoniae and Enterococcus faecalis) that are inhibited at low micromolar to nanomolar concentrations and established the molecular mechanism. F309 in the active site of Type 1 human MetAP (HsMetAP1b) seems to be the key to the resistance, while newly identified ovalicin sensitive Type 1 MetAPs have a methionine or isoleucine at this position. Type 2 human MetAP (HsMetAP2) also has isoleucine (I338) in the analogous position. Ovalicin inhibited F309M and F309I mutants of human MetAP1b at low micromolar concentration. Molecular dynamics simulations suggest that ovalicin is not stably placed in the active site of wild-type MetAP1b before the covalent modification. In the case of F309M mutant and human Type 2 MetAP, molecule spends more time in the active site providing time for covalent modification.


2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Bae Huey Tee ◽  
See Ziau Hoe ◽  
Swee Hung Cheah ◽  
Sau Kuen Lam

AlthoughEurycoma longifoliahas been studied for erectile function, the blood pressure- (BP-) lowering effect has yet to be verified. Hence, this study aims at investigating the BP-lowering properties of the plant with a view to develop an antihypertensive agent that could also preserve erectile function. Ethanolic root extract was partitioned by hexane, dichloromethane (DCM), ethyl acetate, butanol, and water. The DCM fraction, found to be potent in relaxing phenylephrine- (PE-) precontracted rat aortic rings, was further purified by column chromatography. Subfraction DCM-II, being the most active in relaxing aortae, was studied for effects on the renin-angiotensin and kallikrein-kinin systems in aortic rings. The effect of DCM-II on angiotensin-converting enzyme (ACE) activity was also evaluatedin vitro. Results showed that DCM-II reduced (p<0.05) the contractions evoked by angiotensin I and angiotensin II (Ang II). In PE-precontracted rings treated with DCM-II, the Ang II-induced contraction was attenuated (p<0.05) while bradykinin- (BK-) induced relaxation enhanced (p<0.001).In vitro, DCM-II inhibited (p<0.001) the activity of ACE. These data demonstrate that the vasodilatory effect of DCM-II appears to be mediatedviainhibition of Ang II type 1 receptor and ACE as well as enhancement of Ang II type 2 receptor activation and BK activity.


1998 ◽  
Vol 6 (3-4) ◽  
pp. 331-342 ◽  
Author(s):  
Christoph Specht ◽  
Hans-Gerd Pauels ◽  
Christian Becker ◽  
Eckehart Kölsch

The involvement of counteractiveCD8+T-cell subsets during tumor-specific immune responses was analyzed in a syngeneic murine plasmacytoma model.CD8+Tc cells against the immunogenic IL-10-producing BALB/c plasmacytoma ADJ-PC-5 can be easily induced by immunization of BALB/c mice with X-irradiated ADJ-PC-5 tumor cellsin vivoandin vitro. However, the failure of recipient mice to mount a protective Tc response against the tumor during early stages of a real or simulated tumor growth is not due to immunological ignorance, but depends on the induction of tumor-specific tolerance, involving a population of tumorinducedCD8+T cells that are able to inhibit the generation of tumor-specific Tc cells in a primary ADJ-PC-5-specific MLTC, using IFN-γas a suppressive factor. Whereas most longterm cultivated CD8+ADJ-PC-5-specific Tc lines produce type-1 cytokines on stimulation, at least two of them, which were derived from a primary MLTC, display a type-2 cytokine spectrum. Furthermore, the primaryin vitroTc response against ADJ-PC-5 cells shows characteristics of a Tc2 response. The Tc response is strictly depending on tumor-derived IL-10.CD8+Tc cells that are induced in a primary MLTC do not produce IFN-γ, and the tumor-specific Tc response is enhanced by IL-4 but suppressed by IFN-γor IL-12. In contrast, ADJ-PC- 5-specificCD8+Tc cells from immunized mice are IFN-γproducing Tc1 cells. Since the primaryin vitroTc response against the tumor is suppressed even by the smallest numbers of irradiated ADJ-PC-5-specific Tc1 cells via IFN-γthese Tc1 cells behave similar to the suppressiveCD8+T cells that are induced during early stages of ADJ-PC-5 tumorigenesis.


2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Hussein Yassine ◽  
Olgica Trenchevska ◽  
Chad Borges ◽  
Dobrin Nedelkov ◽  
Randall W Nelson ◽  
...  

Serum Amyloid A (SAA) is an acute phase reactant protein that exists in multiple isoforms, can form HDL, and participates in cholesterol efflux. In vitro studies suggest that the SAA 2.1 isoform has an increased capacity to mediate cholesterol efflux compared to the other isoforms. We examined SAA isoforms using a novel mass spectrometric immunoassay (MSIA) and HDL’s cholesterol efflux capacity (via ABCA-1 and SR-BI) in samples from 59 subjects with (n=33) and without type 2 diabetes (n=26). SAA 1.1 levels were detectable in 58, SAA 2.1 in 14 and SAA 2.2 in 36 of the 59 subjects. SAA 2.1 levels significantly correlated with SR-BI cholesterol efflux (r=0.71, p=0.01, n=14), but not ABCA-1 mediated efflux (r=0.1, P=0.1). This correlation was not explained by changes in HDL phospholipids, Apo A-I or HDL cholesterol levels. In contrast, SAA 2.2 or 1.1 levels did not correlate with changes in SR-BI or ABCA-1 mediated efflux. Although the SAA 2.1 isoform is less frequently detected in plasma, our data confirm that it is closely linked with HDL mediated cholesterol efflux, particularly that is SR-BI mediated.


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