Serum amyloid P component therapeutically attenuates atherosclerosis in mice via its effects on macrophages

Potential plasma biomarkers at low altitude for prediction of acute mountain sickness

Background

Ascending to high altitude can induce a range of physiological and molecular alterations, rendering a proportion of lowlanders unacclimatized. The prediction of acute mountain sickness (AMS) prior to ascent to high altitude remains elusive.

Methods

A total of 40 participants were enrolled for our study in the discovery cohort, and plasma samples were collected from all individuals. The subjects were divided into severe AMS-susceptible (sAMS) group, moderate AMS-susceptible (mAMS) group and non-AMS group based on the Lake Louise Score (LLS) at both 5000m and 3700m. Proteomic analysis was conducted on a cohort of 40 individuals to elucidate differentially expressed proteins (DEPs) and associated pathways between AMS-susceptible group and AMS-resistant group at low altitude (1400m) and middle high-altitude (3700m). Subsequently, a validation cohort consisting of 118 individuals was enrolled. The plasma concentration of selected DEPs were quantified using ELISA. Comparative analyses of DEPs among different groups in validation cohort were performed, followed by Receiver Operating Characteristic (ROC) analysis to evaluate the predictive efficiency of DEPs for the occurrence of AMS.

Results

The occurrence of the AMS symptoms and LLS differed significantly among the three groups in the discovery cohort (p<0.05), as well as in the validation cohort. Comparison of plasma protein profiles using GO analysis revealed that DEPs were primarily enriched in granulocyte activation, neutrophil mediated immunity, and humoral immune response. The comparison of potential biomarkers between the sAMS group and non-AMS group at low altitude revealed statistically higher levels of AAT, SAP and LTF in sAMS group (p=0.01), with a combined area under the curve(AUC) of 0.965. Compared to the mAMS group at low altitude, both SAP and LTF were found to be significantly elevated in the sAMS group, with a combined AUC of 0.887. HSP90-α and SAP exhibited statistically higher levels in the mAMS group compared to the non-AMS group at low altitude, with a combined AUC of 0.874.

Conclusion

Inflammatory and immune related biological processes were significantly different between AMS-susceptible and AMS-resistant groups at low altitude and middle high-altitude. SAP, AAT, LTF and HSP90-α were considered as potential biomarkers at low altitude for the prediction of AMS.

The prognostic capability of inflammatory proteins in predicting peripheral artery disease related adverse events

Background

Levels of inflammatory proteins and their prognostic potential have been inadequately studied in patients with peripheral artery disease (PAD). In this study, we quantified and assessed the ability of inflammatory proteins in predicting PAD-related adverse events.

Methods

In this prospective case-control study, blood samples were collected from patients without PAD (n = 202) and patients with PAD (n = 275). The PAD cohort was stratified by disease severity based on ankle brachial index (ABI): mild (n = 49), moderate (n = 164), and severe (n = 62). Patients were followed for 2 years. Plasma concentrations of 5 inflammatory proteins were measured: Alpha-2-Macroglobulin (A2M), Fetuin A, Alpha-1-Acid Glycoprotein (AGP), Serum Amyloid P component (SAP), and Adipsin. The primary outcome of our study was major adverse limb event (MALE), defined as the need for vascular intervention (open or endovascular revascularization) or major amputation. The secondary outcome was worsening PAD status, defined as a drop in ABI greater than or equal to 0.15 over the study period. Multivariable logistic regression was performed to assess the prognostic value of inflammatory proteins in predicting MALE, adjusting for confounding variables.

Results

Compared to patients without PAD, three inflammatory proteins were differentially expressed in patients with PAD (AGP, Fetuin A, and SAP). The primary outcome (MALE) and secondary outcome (worsening PAD) status were noted in 69 (25%) and 60 (22%) patients, respectively. PAD-related adverse events occurred more frequently in severe PAD patients. Based on our data, the inflammatory protein AGP was the most reliable predictor of primary and secondary outcomes. On multivariable analysis, there was a significant association between AGP and MALE in all PAD disease states [mild: adjusted HR 1.13 (95% CI 1.05-1.47), moderate: adjusted HR 1.23 (95% CI 1.16-1.73), severe: adjusted HR 1.37 (95% CI 1.25-1.85)]. High levels of AGP were associated with lower 2-year MALE-free survival in all PAD disease states [mild (64% vs. 100%, p = 0.02), moderate (64% vs. 85%, p = 0.02), severe (55% vs. 88%, p = 0.02), all PAD (62% vs. 88%, p = 0.01)].

Conclusion

Levels of inflammatory protein AGP may help in risk stratifying PAD patients at high risk of MALE and worsening PAD status and subsequently facilitate further vascular evaluation and initiation of aggressive medical/surgical management.

Functional Characterization of Serum Amyloid P Component (SAP) in Host Defense against Bacterial Infection in a Primary Vertebrate

Serum amyloid P component (SAP), an ancient short pentraxin of the pentraxin family, plays an essential role in resistance to bacterial infection. In this study, the expression and functional characterization of SAP (OnSAP) in Nile tilapia (Oreochromis niloticus), a primary vertebrate, are investigated. The open reading frame of OnSAP is 645 bp of a nucleotide sequence encoding a polypeptide of 214 amino acids. As a calcium-binding protein, the structure and relative motif of OnSAP is highly similar to those of humans, containing amino acid residues Asn, Glu, Gln and Asp. In healthy fish, OnSAP mRNA is extensively distributed in all eleven tissues examined, with the highest level in spleen. The mRNA expression of OnSAP was significantly up-regulated after being challenged with gram-positive bacterium Streptococcus agalactiae and gram-negative bacterium Aeromonas hydrophila in vivo. In addition, recombinant OnSAP ((r)OnSAP) protein had capacities of binding S. agalactiae or A. hydrophila in the presence of Ca²⁺. Further, (r)OnSAP helped monocytes/macrophages to efficiently phagocytize bacteria. Moreover, the (r)OnSAP was able to enhance the complement-mediated lysis of the chicken red blood cells. Collectively, the evidence of SAP in tilapia, based on the results including its evolutionary conserved protein structure, bacterial binding and agglutination, opsonophagocytosis of macrophage and hemolysis enhancement, enriches a better understanding of the biological functions of the pentraxin family.

Deficiency of proline/serine-rich coiled-coil protein 1 (PSRC1) accelerates trimethylamine N-oxide-induced atherosclerosis in ApoE-/- mice

AIMS

The main therapeutic strategies for coronary artery disease (CAD) are mainly based on the correction of abnormal cholesterol levels; however, residual risks remain. The newly proven gut microbial metabolite trimethylamine N-oxide (TMAO) linked with CAD has broadened our horizons. In this study, we determined the role of proline/serine-rich coiled-coil protein 1 (PSRC1) in TMAO-driven atherosclerosis.

METHODS AND RESULTS

We first analyzed the levels of TMAO and PSRC1 in patients with or without atherosclerosis with a target LDL-C < 1.8 mmol/L. Plasma TMAO levels were increased and negatively associated with decreased PSRC1 in peripheral blood mononuclear cells. Animals and in vitro studies showed that TMAO inhibited macrophage PSRC1 expression due to DNA hypermethylation of CpG islands. ApoE^-/- mice fed a choline-supplemented diet exhibited reduced PSRC1 expression accompanied by increased atherosclerotic lesions and plasma TMAO levels. We further deleted PSRC1 in apoE^-/- mice and PSRC1 deficiency significantly accelerated choline-induced atherogenesis, characterized by increased macrophage infiltration, foam cell formation and M1 macrophage polarization. Mechanistically, we overexpressed and knocked out PSRC1 in cultured macrophages to explore the mechanisms underlying TMAO-induced cholesterol accumulation and inflammation. PSRC1 deletion impaired reverse cholesterol transport and enhanced cholesterol uptake and inflammation, while PSRC1 overexpression rescued the proatherogenic phenotype observed in TMAO-stimulated macrophages, which was partially attributed to sulfotransferase 2B1b (SULT2B1b) inhibition.

CONCLUSIONS

Herein, clinical data provide evidence that TMAO may participate in the development of CAD beyond well-controlled LDL-C levels. Our work also suggests that PSRC1 is a negative regulator mediating the unfavorable effects of TMAO-containing diets. Therefore, PSRC1 overexpression and reduced choline consumption may further alleviate atherosclerosis.

Plasma proteomics reveals crosstalk between lipid metabolism and immunity in dairy cows receiving essential fatty acids and conjugated linoleic acid

Essential fatty acids (EFA) and conjugated linoleic acids (CLA) are unsaturated fatty acids with immune-modulatory effects, yet their synergistic effect is poorly understood in dairy cows. This study aimed at identifying differentially abundant proteins (DAP) and their associated pathways in dairy cows supplied with a combination of EFA and CLA during the transition from antepartum (AP) to early postpartum (PP). Sixteen Holstein cows were abomasally infused with coconut oil as a control (CTRL) or a mixture of EFA (linseed + safflower oil) and CLA (Lutalin, BASF) (EFA + CLA) from − 63 to + 63 days relative to parturition. Label-free quantitative proteomics was performed on plasma samples collected at days − 21, + 1, + 28, and + 63. During the transition time, DAP, consisting of a cluster of apolipoproteins (APO), including APOE, APOH, and APOB, along with a cluster of immune-related proteins, were related to complement and coagulation cascades, inflammatory response, and cholesterol metabolism. In response to EFA + CLA, specific APO comprising APOC3, APOA1, APOA4, and APOC4 were increased in a time-dependent manner; they were linked to triglyceride-enriched lipoprotein metabolisms and immune function. Altogether, these results provide new insights into metabolic and immune adaptation and crosstalk between them in transition dairy cows divergent in EFA + CLA status.

Decreased Iron Ion Concentrations in the Peripheral Blood Correlate with Coronary Atherosclerosis

(1) Background: Obesity and diabetes continue to reach epidemic levels in the population with major health impacts that include a significantly increased risk of coronary atherosclerosis. The imbalance of trace elements in the body caused by nutritional factors can lead to the progression of coronary atherosclerosis. (2) Methods: We measured the concentrations of sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), Zinc (Zn), and iron (Fe) in peripheral blood samples from 4243 patients and performed baseline analysis and propensity matching of the patient datasets. The patients were grouped into acute myocardial infarction (AMI, 702 patients) and stable coronary heart disease (SCAD1, 253 patients) groups. Both of these groups were included in the AS that had a total of 1955 patients. The control group consisted of 2288 patients. The plasma concentrations of calcium, magnesium, and iron were measured using a colorimetric method. For comparison, 15 external quality assessment (EQA) samples were selected from the Clinical Laboratory Center of the Ministry of Health of China. SPSS software was used for statistical analysis. The average values and deviations of all of the indicators in each group were calculated, and a p-value threshold of <0.05 was used to indicate statistical significance. (3) Results: The iron ion concentrations of the acute myocardial infarction (AMI) group were significantly lower than the control group (p < 0.05, AUC = 0.724, AUC = 0.702), irrespective of tendency matching. Compared to the data from the stable coronary artery disease (SCAD) group, the concentration of iron ions in the acute myocardial infarction group was significantly lower (p < 0.05, AUC = 0.710, AUC = 0.682). Furthermore, the iron ion concentrations in the (AMI + SCAD) group were significantly lower (p < 0.05) than in the control group. (4) Conclusions: The data presented in this study strongly indicate that the concentration of iron ions in the peripheral blood is related to coronary atherosclerosis. Decreases in the levels of iron ions in the peripheral blood can be used as a predictive biomarker of coronary atherosclerosis.

Proteomic Studies of Blood and Vascular Wall in Atherosclerosis

The review is devoted to the analysis of literature data related to the role of proteomic studies in the study of atherosclerotic cardiovascular diseases. Diagnosis of patients with atherosclerotic plaques before clinical manifestations is an arduous task. The review presents the results of research on the new proteomic potential biomarkers of coronary heart disease, coronary atherosclerosis, acute coronary syndrome, myocardial infarction, carotid artery atherosclerosis. Also, the analysis of literature data on proteomic studies of the vascular wall was carried out. To assess the involvement of proteins in the pathological process of atherosclerosis, it is important to investigate the specific relationships between proteins in the arteries, expression and concentration of proteins. The development of proteomic technologies has made it possible to analyse the number of proteins associated with the development of the disease. Analysis of the proteomic profile of the vascular wall in atherosclerosis can help to detect possible diagnostically significant protein structures or potential biomarkers of the disease and develop novel approaches to the diagnosis of atherosclerosis and its complications.

Effect of renal function on high-density lipoprotein particles in patients with coronary heart disease

BACKGROUND

Although renal insufficiency and dyslipidemia are known to be closely associated, the effect of kidney function on the size and clinical value of high-density lipoprotein (HDL) particles remains largely unknown, especially in patients with coronary heart disease.

METHODS

A total of 419 coronary heart disease patients and 105 non-coronary heart disease patients were included. HDL particle size, represented by HDL-C/apoA-I, was compared between groups stratified by estimated glomerular filtration rate (eGFR) and Gensini scores using standard Student's t test and one-way ANOVA. Pearson's correlation test was performed to analyze the association between eGFR and HDL-C/apoA-I in patients with coronary heart disease. The relationship between HDL particle size and the occurrence of coronary heart disease was explored using Univariate logistic regression analysis.

RESULTS

In patients with coronary heart disease, between-group analysis revealed that HDL-C/apoA-I increased as eGFR declined, and significance appeared as eGFR declined to under 60 ml/min·1.73 m² (P < 0.001), and Pearson's correlation test also confirmed an inverse correlation between eGFR and HDL-C/apoA-I levels in coronary heart disease patients. When stratified by Gensini scores, in coronary heart disease patients with eGFR ≥ 90 mL/(min·1.73 m²), those with higher Gensini scores had smaller HDL-C/apoA-I. However, with or without kidney insufficiency, smaller HDL-C/apoA-I was associated with a higher occurrence of coronary heart disease (P < 0.05).

CONCLUSION

With the presence of renal insufficiency, HDL-C/apoA1 was higher in patients with coronary heart disease. Lower HDL-C/apoA1 was still associated with a higher occurrence of coronary heart disease, but the original association between lower HDL-C/apoA1 and more severe coronary artery stenosis was lost in patients with renal insufficiency.

Yin-xing-tong-mai decoction attenuates atherosclerosis via activating PPARγ-LXRα-ABCA1/ABCG1 pathway

Atherosclerosis is now the major cause of mortality and morbidity worldwide. Formation of macrophage-derived foam cells is a hallmark of atherosclerosis, which is regulated by cholesterol uptake, intracellular metabolism, and efflux. PPARγ-LXRα-ABCA1/ABCG1 pathway plays an important part in regulating cholesterol efflux and this pathway could be a promising target for treating atherosclerosis. However, due to undesirable systemic effects, PPARγ agonist therapy for atherosclerosis remains challenging. Many traditional Chinese medicine has been well accepted and applied in atherosclerosis treatment. Yin-xing-tong-mai decoction (YXTMD) has been applied for treating atherosclerosis for decades. However, the mechanism remains to be explored. Here, we showed that YXTMD effectively attenuated atherosclerosis in ApoE^-/- mice. YXTMD increased cholesterol efflux of foam cell by upregulation of ABCA1 and ABCG1 in vivo and in vitro. Through bioinformatic analysis and experimental validation, we found that PPARγ was an important downstream effector of YXTMD in macrophages. Reduction of PPARγ significantly decreased LXRα, ABCA1, and ABCG1 expression in macrophages, with reduced cholesterol efflux. In conclusion, these findings confirmed that YXTMD attenuated atherosclerosis by activating the PPARγ-LXRα- ABCA1/ABCG1 pathway to enhance cholesterol efflux.

A CD209 ligand and a sialidase inhibitor differentially modulate adipose tissue and liver macrophage populations and steatosis in mice on the Methionine and Choline-Deficient (MCD) diet

Non-alcoholic fatty liver disease (NAFLD) is associated with obesity and type 2 diabetes and is characterized by the accumulation of fat in the liver (steatosis). NAFLD can transition into non-alcoholic steatohepatitis (NASH), with liver cell injury, inflammation, and an increased risk of fibrosis. We previously found that injections of either 1866, a synthetic ligand for the lectin receptor CD209, or DANA, a sialidase inhibitor, can inhibit inflammation and fibrosis in multiple animal models. The methionine and choline-deficient (MCD) diet is a model of NASH which results in the rapid induction of liver steatosis and inflammation. In this report, we show that for C57BL/6 mice on a MCD diet, injections of both 1866 and DANA reversed MCD diet-induced decreases in white fat, decreases in adipocyte size, and white fat inflammation. However, these effects were not observed in type 2 diabetic db/db mice on a MCD diet. In db/db mice on a MCD diet, 1866 decreased liver steatosis, but these effects were not observed in C57BL/6 mice. There was no correlation between the ability of 1866 or DANA to affect steatosis and the effects of these compounds on the density of liver macrophage cells expressing CLEC4F, CD64, F4/80, or Mac2. Together these results indicate that 1866 and DANA modulate adipocyte size and adipose tissue macrophage populations, that 1866 could be useful for modulating steatosis, and that changes in the local density of 4 different liver macrophages cell types do not correlate with effects on liver steatosis.

Endothelial to mesenchymal transition contributes to nicotine-induced atherosclerosis

Rationale: Nicotine exposure via cigarette smoking is strongly associated with atherosclerosis. However, the underlying mechanisms remain poorly understood. The current study aimed to identify whether endothelial to mesenchymal transition (EndMT) contributes to nicotine-induced atherosclerosis. Methods: ApoE-/- mice were administered nicotine in their drinking water for 12 weeks. The effects of nicotine on EndMT were determined by immunostaining on aortic root and RNA analysis in aortic intima. In vitro nicotine-treated cell model was established on human aortic endothelial cells (HAECs). The effects of nicotine on the expression of EndMT-related markers, ERK1/2 and Snail were quantified by real-time PCR, western blot and immunofluorescent staining. Results: Nicotine treatment resulted in larger atherosclerotic plaques in ApoE-/- mice. The vascular endothelial cells from nicotine-treated mice showed mesenchymal phenotype, indicating EndMT. Moreover, nicotine-induced EndMT process was accompanied by cytoskeleton reorganization and impaired barrier function. The α7 nicotine acetylcholine receptor (α7nAChR) was highly expressed in HAECs and its antagonist could effectively relieve nicotine-induced EndMT and atherosclerotic lesions in mice. Further experiments revealed that ERK1/2 signaling was activated by nicotine, which led to the upregulation of Snail. Blocking ERK1/2 with inhibitor or silencing Snail by small interfering RNA efficiently preserved endothelial phenotype upon nicotine stimulation. Conclusion: Our study provides evidence that EndMT contributes to the pro-atherosclerotic property of nicotine. Nicotine induces EndMT through α7nAChR-ERK1/2-Snail signaling in endothelial cells. EndMT may be a therapeutic target for smoking-related endothelial dysfunction and cardiovascular disease.

Molecular signatures of atherosclerotic plaques: An up-dated panel of protein related markers

Atherosclerosis remains the leading cause of ischemic syndromes such as myocardial infarction or brain stroke, mainly promoted by plaque rupture and subsequent arterial blockade. Identification of vulnerable or high-risk plaques constitutes a major challenge, being necessary to identify patients at risk of occlusive events in order to provide them with appropriate therapies. Clinical imaging tools have allowed the identification of certain structural indicators of prone-rupture plaques, including a necrotic lipidic core, intimal and adventitial inflammation, extracellular matrix dysregulation, and smooth muscle cell depletion and micro-calcification. Additionally, alternative approaches focused on identifying molecular biomarkers of atherosclerosis have also been applied. Among them, proteomics has provided numerous protein markers currently investigated in clinical practice. In this regard, it is quite uncertain that a single molecule can describe plaque rupture, due to the complexity of the process itself. Therefore, it should be more accurate to consider a set of markers to define plaques at risk. Herein, we propose a selection of 76 proteins, from classical inflammatory to recently related markers, all of them identified in at least two proteomic studies analyzing unstable atherosclerotic plaques. Such panel could be used as a prognostic signature of plaque instability.

SULT2B1b inhibits reverse cholesterol transport and promotes cholesterol accumulation and inflammation in lymphocytes from AMI patients with low LDL-C levels

The current main treatment for coronary artery disease (CAD) is to reduce low-density lipoprotein cholesterol (LDL-C) by statins, which could decrease the incidence of major adverse cardiovascular events (MACEs) by 30%. However, many residual risks still remain. To clarify the mechanism involved, we studied patients with acute myocardial infarction (AMI) with low LDL-C levels. Lymphocytes were isolated, and it was found that despite no difference in plasma LDL-C level, the lymphocyte cholesterol content was higher in AMI patient than those in non-CAD patients; thus, the decrease in intracellular cholesterol content was inconsistent with that in the plasma. Additionally, [3H]-cholesterol efflux rates were lower and mRNA levels of the inflammatory factors tumour necrosis factor-α (TNF-α) and interferon-γ (IFN-γ) higher in AMI lymphocytes. It was found that sulphotransferase 2B1b (SULT2B1b) expression was higher in AMI lymphocytes. Further research using Jurkat T lymphocytes confirmed that SULT2B1b knockdown increased cholesterol efflux capacity and decreased mRNA levels of TNF-α and IFN-γ by increasing liver X receptor (LXR)-β levels. Furthermore, the degree of CpG island methylation in the SULT2B1b promoter was reduced in cells from AMI patients. In conclusion, SULT2B1b up-regulation due to hypomethylation of its promoter promotes cholesterol accumulation and inflammation by inhibiting LXR-β in lymphocytes of AMI patients with low LDL-C levels. Therefore, reducing intracellular cholesterol is also important as plasma cholesterol levels. Therapeutic approaches to decrease SULT2B1b expression might be potentially beneficial for CAD prevention by decreasing intracellular cholesterol.

LCK inhibitor attenuates atherosclerosis in ApoE-/- mice via regulating T cell differentiation and reverse cholesterol transport

Lots of studies demonstrated that CD4⁺ T cells regulate the development of atherosclerosis (AS). Previously, we reported that LCK, a key molecule in activation of T cell receptor (TCR) signalling and T cells, adversely affects reverse cholesterol transport (RCT), which ameliorates AS in vitro. To investigate the effect of LCK on AS in vivo, we injected the LCK inhibitor, PP2, into ApoE^-/- mice fed a chow diet or a high-fat diet (HFD). Although, AS plaques were not affected by PP2 in chow diet-fed mice, PP2 significantly reduced the lesion percentage and necrotic core areas in HFD-fed mice. We further analysed the plaque contents and found that the accumulation of lipids and macrophages were decreased, while the contents of collagen and smooth muscle cells were increased by the LCK inhibitor. Thus, inhibiting LCK enhanced the plaque stability. We also found the LCK inhibitor improved cholesterol efflux capacity of HDL and up-regulated RCT regulatory proteins in the spleen. Moreover, inhibiting LCK regulated differentiation of T cells by increasing regulatory T (Treg) cells and decreasing the number of T helper 1 (Th1) cells in the aorta, thymus and spleen. Consistent with these results, infiltration of CD4⁺ T cells in plaques, secretion of pro-atherosclerotic cytokines, INF-γ and TNF-α synthesized mostly by Th1 cells, and the activation of PI3K/AKT/mTOR signalling were inhibited by the LCK inhibitor. Moreover, the effect of LCK inhibitor on the ratio of Th1 to Treg cells were compromised by activation of mTOR. Together, these data indicate that inhibiting LCK in TCR signalling attenuated the development of AS and promoted plaque stability. Improving RCT by upregulating RCT regulatory proteins and decreasing the Th1/Treg ratio by inhibiting PI3K/AKT/mTOR signalling may contribute to the anti-atherosclerotic effects of LCK inhibition.

Mief1 augments thyroid cell dysfunction and apoptosis through inhibiting AMPK-PTEN signaling pathway

Objective: Inflammation-mediated thyroid cell dysfunction and apoptosis increases the like-hood of hypothyroidism.Aim: Our aim in the present study is to explore the role of mitochondrial elongation factor 1 (Mief1) in thyroid cell dysfunction induced by TNFα.Materials and methods: Different doses of TNFα were used to incubate with thyroid cells in vitro. The survival rate, apoptotic index and proliferation capacity of thyroid cells were measured. Cellular energy metabolism and endoplasmic reticulum function related to protein synthesis were detected.Results: In response to TNFα treatment, the levels of Mief1 were increased, coinciding with a drop in the viability of thyroid cells in vitro. Loss of Mief1 attenuates TNFα-induced cell death through reducing the ratio of cell apoptosis. Further, we found that Mief1 deletion reversed cell energy metabolism and this effect was attributable to mitochondrial protection. Mief1 knockdown sustained mitochondrial membrane potential and reduced mitochondrial ROS overproduction. In addition, Mief1 knockdown also reduced endoplasmic reticulum stress, as evidenced by decreased levels of Chop and Caspase-12. Finally, our data verified that TNFα treatment inhibited the activity of AMPK-PTEN pathway whereas Mief1 deletion reversed the activity of AMPK and thus promoted the upregulation of PTEN. However, inhibition of AMPK-PTEN pathways could abolish the beneficial effects exerted by Mief1 deletion on thyroid cells damage and dysfunction.Conclusions: Altogether, our data indicate that immune abnormality-mediated thyroid cell dysfunction and death are alleviated by Mief1 deletion possible driven through reversing the activity of AMPK-PTEN pathways.

Formononetin attenuates atherosclerosis via regulating interaction between KLF4 and SRA in apoE-/- mice

Background and Purpose: Atherosclerosis is an underlying cause of coronary heart disease. Foam cell, a hallmark of atherosclerosis, is prominently derived from monocyte-differentiated macrophage, and vascular smooth muscle cells (VSMCs) through unlimitedly phagocytizing oxidized low-density lipoprotein (oxLDL). Therefore, the inhibition of monocyte adhesion to endothelium and uptake of oxLDL might be a breakthrough point for retarding atherosclerosis. Formononetin, an isoflavone extracted from Astragalus membranaceus, has exhibited multiple inhibitory effects on proatherogenic factors, such as obesity, dyslipidemia, and inflammation in different animal models. However, its effect on atherosclerosis remains unknown. In this study, we determined if formononetin can inhibit atherosclerosis and elucidated the underlying molecular mechanisms.

Methods: ApoE deficient mice were treated with formononetin contained in high-fat diet for 16 weeks. After treatment, mouse aorta, macrophage and serum samples were collected to determine lesions, immune cell profile, lipid profile and expression of related molecules. Concurrently, we investigated the effect of formononetin on monocyte adhesion, foam cell formation, endothelial activation, and macrophage polarization in vitro and in vivo.

Results: Formononetin reduced en face and aortic root sinus lesions size. Formononetin enhanced lesion stability by changing the composition of plaque. VSMC- and macrophage-derived foam cell formation and its accumulation in arterial wall were attenuated by formononetin, which might be attributed to decreased SRA expression and reduced monocyte adhesion. Formononetin inhibited atherogenic monocyte adhesion and inflammation. KLF4 negatively regulated the expression of SRA at transcriptional and translational level.

Conclusions: Our study demonstrate that formononetin can substantially attenuate the development of atherosclerosis via regulation of interplay between KLF4 and SRA, which suggests the formononetin might be a novel therapeutic approach for inhibition of atherosclerosis.

A Proteomic Study of Atherosclerotic Plaques in Men with Coronary Atherosclerosis

Background: To study the changes in protein composition of atherosclerotic plaques at different stages of their development in coronary atherosclerosis using proteomics. Methods: The object of research consisted of homogenates of atherosclerotic plaques from coronary arteries at different stages of development, obtained from 15 patients. Plaque proteins were separated by two-dimensional electrophoresis. The resultant protein spots were identified by the matrix-assisted laser desorption ionization method with peptide mass mapping. Results: Groups of differentially expressed proteins, in which the amounts of proteins differed more than twofold (p < 0.05), were identified in pools of homogenates of atherosclerotic plaques at three stages of development. The amounts of the following proteins were increased in stable atherosclerotic plaques at the stage of lipidosis and fibrosis: vimentin, tropomyosin β-chain, actin, keratin, tubulin β-chain, microfibril-associated glycoprotein 4, serum amyloid P-component, and annexin 5. In plaques at the stage of fibrosis and calcification, the amounts of mimecan and fibrinogen were increased. In unstable atherosclerotic plaque of the necrotic–dystrophic type, the amounts of human serum albumin, mimecan, fibrinogen, serum amyloid P-component and annexin were increased. Conclusion: This proteomic study identifies the proteins present in atherosclerotic plaques of coronary arteries by comparing their proteomes at three different stages of plaque development during coronary atherosclerosis.

Serum Amyloid P and a Dendritic Cell-Specific Intercellular Adhesion Molecule-3-Grabbing Nonintegrin Ligand Inhibit High-Fat Diet-Induced Adipose Tissue and Liver Inflammation and Steatosis in Mice

High-fat diet (HFD)-induced inflammation is associated with a variety of health risks. The systemic pentraxin serum amyloid P (SAP) inhibits inflammation. SAP activates the high-affinity IgG receptor Fcγ receptor I (FcγRI; CD64) and the lectin receptor dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN; CD209). Herein, we show that for mice on an HFD, injections of SAP and a synthetic CD209 ligand (1866) reduced HFD-increased adipose and liver tissue inflammation, adipocyte differentiation, and lipid accumulation in adipose tissue. HFD worsened glucose tolerance test results and caused increased adipocyte size; for mice on an HFD, SAP improved glucose tolerance test results and reduced adipocyte size. Mice on an HFD had elevated serum levels of IL-1β, IL-23, interferon (IFN)-β, IFN-γ, monocyte chemoattractant protein 1 [MCP-1; chemokine (C-C motif) ligand 2 (CCL2)], and tumor necrosis factor-α. SAP reduced serum levels of IL-23, IFN-β, MCP-1, and tumor necrosis factor-α, whereas 1866 reduced IFN-γ. In vitro, SAP, but not 1866, treated cells isolated from white fat tissue (stromal vesicular fraction) produced the anti-inflammatory cytokine IL-10. HFD causes steatosis, and both SAP and 1866 reduced it. Conversely, compared with control mice, SAP knockout mice fed on a normal diet had increased white adipocyte cell sizes, increased numbers of inflammatory cells in adipose and liver tissue, and steatosis; and these effects were exacerbated on an HFD. SAP and 1866 may inhibit some, but not all, of the effects of a high-fat diet.