Atherosclerosis: perspectives of anti-inflammatory therapy

Shikonin Alleviates Endothelial Cell Injury Induced by ox-LDL via AMPK/Nrf2/HO-1 Signaling Pathway

The present study aimed to explore the effects of shikonin (SKN) on the damage of human venous endothelial cells (HUVECs) induced by ox-LDL and the underlying molecular mechanism. The HUVECs were randomly divided into six groups: control, ox-LDL, SKN + ox-LDL, SKN + ox-LDL + compound C, SKN + ox-LDL + si-Nrf2, and SKN + ox-LDL + si-HO-1. The MTT method was used to detect cell viability, flow cytometry was used to detect cell apoptosis and reactive oxygen species (ROS) levels, and Western blot was used to detect protein levels. Compared to the control group, the cell viability of the ox-LDL group decreased, the apoptosis rate increased, the level of cleaved caspase-3 was upregulated, and the level of Bcl-2 protein was downregulated. The level of TNF-α, IL-1β, IL-6, vascular cell adhesion molecule-1 (VCAM1), intercellular adhesion molecule-1 (ICAM1), and E-selectin (E-sel) was increased, ROS levels increased, and superoxide dismutase (SOD) level decreased. Moreover, the protein levels of p-AMPK, Nrf2, and HO-1 were decreased. Compared to the ox-LDL group, SKN treatment improves cell viability, alleviates cell apoptosis and oxidative stress injury, and upregulates the protein levels of p-AMPK, Nrf2, and HO-1. Compound C, si-Nrf2, and si-HO-1 administration inhibits the AMPK/Nrf2/HO-1 signaling pathway, increases ROS generation, and inhibits the antagonistic effect of SKN on ox-LDL-induced HUVECs damage. In summary, SKN suppressed ox-LDL-induced ROS production and improved cell viability and cell apoptosis via the AMPK/Nrf2/HO-1 pathway.

Molecular mechanism of the anti-inflammatory effects of Sophorae Flavescentis Aiton identified by network pharmacology

Inflammation, a protective response against infection and injury, involves a variety of biological processes. Sophorae Flavescentis (Kushen) is a promising Traditional Chinese Medicine (TCM) for treating inflammation, but the pharmacological mechanism of Kushen’s anti-inflammatory effect has not been fully elucidated. The bioactive compounds, predicted targets, and inflammation-related targets of Kushen were obtained from open source databases. The “Component-Target” network and protein–protein interaction (PPI) network were constructed, and hub genes were screened out by topological analysis. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed on genes in the PPI network. Furthermore, nitric oxide (NO) production analysis, RT-PCR, and western blot were performed to detect the mRNA and protein expression of hub genes in LPS-induced RAW264.7 cells. An immunofluorescence assay found that NF-κB p65 is translocated. A total of 24 bioactive compounds, 465 predicted targets, and 433 inflammation-related targets were identified and used to construct “Component-Targets” and PPI networks. Then, the five hub genes with the highest values-IL-6, IL-1β, VEGFA, TNF-α, and PTGS2 (COX-2)- were screened out. Enrichment analysis results suggested mainly involved in the NF-κB signaling pathway. Moreover, experiments were performed to verify the predicted results. Kushen may mediate inflammation mainly through the IL-6, IL-1β, VEGFA, TNF-α, and PTGS2 (COX-2), and the NF-κB signaling pathways. This finding will provide clinical guidance for further research on the use of Kushen to treat inflammation.

Plant-Based Nutritional Supplementation Attenuates LPS-Induced Low-Grade Systemic Activation

Plant-based nutritional supplementation has been shown to attenuate and reduce mortality in the processes of both acute and chronic disorders, including diabetes, obesity, cardiovascular disease, cancer, inflammatory diseases, and neurological and neurodegenerative disorders. Low-level systemic inflammation is an important contributor to these afflictions and diets enriched in phytochemicals can slow the progression. The goal of this study was to determine the impact of lipopolysaccharide (LPS)-induced inflammation on changes in glucose and insulin tolerance, performance enhancement, levels of urinary neopterin and concentrations of neurotransmitters in the striatum in mouse models. Both acute and chronic injections of LPS (2 mg/kg or 0.33 mg/kg/day, respectively) reduced glucose and insulin tolerance and elevated neopterin levels, which are indicative of systemic inflammatory responses. In addition, there were significant decreases in striatal neurotransmitter levels (dopamine and DOPAC), while serotonin (5-HT) levels were essentially unchanged. LPS resulted in impaired execution in the incremental loading test, which was reversed in mice on a supplemental plant-based diet, improving their immune function and maintaining skeletal muscle mitochondrial activity. In conclusion, plant-based nutritional supplementation attenuated the metabolic changes elicited by LPS injections, causing systemic inflammatory activity that contributed to both systemic and neurological alterations.

Serum Heparanase: A New Clinical Biomarker Involved in Senile Metabolic Inflammatory Syndrome

AIM

Metabolic inflammation syndrome (MIS) can lead to a series of complications, but its exact inflammatory mechanism is still unclear. The aim of this study was to explore the correlation between heparanase (HPA) and MIS, and the close relationship between HPA and other chronic low-grade inflammation index, such as C-reactive protein (CRP) and interleukin-6 (IL-6).

METHODS

A total of 105 patients with MIS in the physical examination population of Huashan Hospital affiliated to Fudan University from May to June 2018 were selected as the MIS group, and 52 patients who were relatively healthy during the same period were used as the control group. The basic clinical data of the selected candidates were collected, the levels of serum HPA, CRP and IL-6 were measured by ELISA, and the levels of blood glucose and blood lipids were also detected.

RESULTS

Compared with the control group, the levels of HPA, CRP, IL-6, FBG, HbA_1C, and TG of MIS group were all significantly elevated (all P<0.05), and HDL-C levels were considerably reduced (P<0.05). Correlation analysis showed that there was a noticeably positive correlation between serum HPA level and CRP, IL-6 levels (P<0.05).

CONCLUSION

Higher HPA levels might play a certain role in the occurrence and development of MIS. There was a certain close correlation between serum HPA level and CRP and IL-6 levels, and which indicated that HPA was involved in the chronic low-grade inflammatory reaction process of MIS.

Exosomes: Multifaceted Messengers in Atherosclerosis

PURPOSE OF REVIEW

Atherosclerosis (AS) is a chronic inflammatory disease that contributes to the development of coronary artery disease, which has become a leading health burden worldwide. Though several strategies such as pharmacological treatment, exercise intervention, and surgery have been used in clinical practice, there is still no effective strategy to cure AS. Exosomes are extensively studied both as diagnostic markers as well as for therapeutic purposes due to their role in pathological processes related to AS. To elucidate the role of exosomes in AS and thus provide a new insight into AS therapy, we review recent advances concerning exosome targets and their function in mediating intercellular communication in AS, and expect to provide a reference for novel effective strategies to cure AS.

RECENT FINDINGS

Exosomes exert important roles in the diagnosis, development, and potential therapy of AS. For AS development, (1) activation of CD-137 in endothelial cells represses exosomal-TET2 production, causing a phenotypic switch of vascular smooth muscle cells (VSMC) and promoting plaque formation; (2) exosomal-MALTA1 derived from endothelial cells causes neutrophil extracellular traps (NETs) and M2 macrophage polarization, which aggravates AS; and (3) exosomal-miR-21-3p derived from macrophages inhibits PTEN expression and further promotes VSMC migration/proliferation, leading to AS development. For AS diagnosis, plasma exosomal-miR30e and miR-92a are considered to be potential diagnostic markers. For AS therapy, adipose mesenchymal stem cell-derived exosomes protect endothelial cells from AS aggravation, via inhibiting miR-342-5p. Exosome-mediated cross-talk between different cells within the vasculature exerts crucial roles in regulating endothelial function, proliferation and differentiation of vascular smooth muscle cells, and platelet activation as well as macrophage activation, collectively leading to the development and progression of AS. Exosomes can potentially be used as diagnostic biomarkers and constitute as a new therapeutic strategy for AS.

Comparison of the Protective Effects of Ginsenosides Rb1 and Rg1 on Improving Cognitive Deficits in SAMP8 Mice Based on Anti-Neuroinflammation Mechanism

This present study was designed to investigate the different effects of ginsenosides Rb1 and Rg1 on improving cognitive deficits in 4-month-old SAMP8 mice. Mice were divided into six groups, including the SAMP8 group, the SAMP8 + Donepezil (1.6 mg/kg) group, the SAMP8 + Rb1 (30 and 60 µmol/kg), and SAMP8 + Rg1 (30 and 60 µmol/kg) groups. SAMR1 mice of the same age were used as the control group. Ginsenosides and donepezil were administrated orally to animals for 8 weeks, then the learning and memory ability of mice were measured by using Morris water maze (MWM) test, object recognition test and passive avoidance experiments. The possible mechanisms were studied including the anti-glial inflammation of Rb1 and Rg1 using HE staining, immunohistochemistry and western blot experiments. Results revealed that Rb1 and Rg1 treatment significantly improved the discrimination index of SAMP8 mice in the object recognition test. Rb1 (60 µmol/kg) and Rg1 (30, 60 µmol/kg) could significantly shorten the escape latency in the acquisition test of the MWM test in SAMP8 mice. Furthermore, Rb1 and Rg1 treatments effectively reduced the number of errors in the passive avoidance task in SAMP8 mice. Western blot experiments revealed that Rb1 showed higher effect than Rg1 in decreasing protein expression levels of ASC, caspase-1 and Aβ in the hippocampus of SAMP8 mice, while Rg1 was more effective than Rb1 in decreasing the protein levels of iNOS. In addition, although Rb1 and Rg1 treatments showed significant protective effects in repairing neuronal cells loss and inhibiting the activation of astrocyte and microglia in hippocampus of SAMP8 mice, Rb1 was more effective than Rg1. These results suggest that Rb1 and Rg1 could improve the cognitive impairment in SAMP8 mice, and they have different mechanisms for the treatment of Alzheimer's disease.

Interleukin-1β Regulates Lipid Homeostasis in Human Glomerular Mesangial Cells

BACKGROUND

Recent studies have shown that hyperlipidemia is closely related to the progression of kidney disease and glomerulosclerosis has similar pathophysiological mechanisms with atherosclerosis. Atherosclerosis is essentially a chronic inflammatory process and various kidney diseases are characterized by a micro-inflammatory state. Hyperlipidemia levels are not parallel to the degree of glomerulosclerosis, inflammatory factors together with lipids may contribute to the pathogenesis of glomerulosclerosis. Therefore, it is key to clarify lipid-mediated renal injury through studying the mechanism by which inflammation affects cholesterol homeostasis at the cellular level. Intracellular lipid homeostasis involves both lipid uptake and excretion, therefore in this study, we aimed to explore whether interleukin-1β (IL-1β) promotes the uptake of oxidized low-density lipoprotein (Ox-LDL) to increase in intracellular lipid levels, and to clarify the effect of IL-1β on the expression of lectin-like oxidized LDL receptor 1 (LOX-1) and ATP-binding cassette transporter A1 (ABCA1), which may regulate cholesterol homeostasis in human mesangial cells (HMCs).

METHODS

The effect of IL-1β on uptake of Ox-LDL labeled with fluorescent Dil (Dil-Ox-LDL) by HMCs was observed using laser confocal microscopy. The effect of IL-1β on LOX-1 and ABCA1 expression in HMCs was detected by polymerase chain reaction and western blotting.

RESULTS

Laser confocal microscopy revealed that HMCs took up Dil-Ox-LDL. Treatment of HMCs with 5 ng/ml IL-1β for 24 h significantly increased uptake of Dil-Ox-LDL. IL-1β also promoted LOX-1 mRNA and protein expression in a dose-dependent manner. Moreover, ABCA1 mRNA and protein expression were reduced by IL-1β in lipid-loaded HMCs in a dose-dependent manner.

CONCLUSIONS

IL-1β promotes the uptake of Ox-LDL and expression of LOX-1 in HMCs, whereas it inhibits expression of ABCA1 under lipid load. The imbalance in intracellular cholesterol resulted by IL-1β can in turn transform HMCs into foam cells and aggravate glomerulosclerosis.

Interleukin-1β Promotes Ox-LDL Uptake by Human Glomerular Mesangial Cells via LOX-1

The aim of this study was to determine whether interleukin-1β (IL-1β) promotes oxidised low-density lipoprotein (Ox-LDL) uptake by human glomerular mesangial cells (HMCs) and its effect on the expression of lectin-like Ox-LDL receptor 1 (LOX-1) and to identify pathways through which IL-1β affects lipid uptake. Confocal laser scanning microscopy and flow cytometry were used to observe the effect of IL-1β on lipid uptake by HMCs and the pathway by which IL-1β may mediate lipid uptake. Real-time polymerase chain reaction (PCR) and western blotting were used to evaluate the effect of IL-1β on LOX-1 expression. Confocal laser scanning microscopy and flow cytometry revealed that IL-1β promoted uptake of fluorescent Dil-labelled Ox-LDL(Dil-Ox-LDL) by HMCs and the enhanced uptake of Dil-Ox-LDL was partially inhibited by an anti-LOX-1 antibody evaluated by flow cytometry. Further, IL-1β promoted LOX-1 mRNA and protein expression of HMCs in a dose- and time-dependent manner. Thus, Ox-LDL is ingested by HMCs under basic conditions. Inflammatory cytokine IL-1β promotes Ox-LDL uptake by HMCs. Furthermore, IL-1β promotes the mRNA and protein expression of LOX-1, a specific receptor of Ox-LDL, suggesting that the enhancement of Ox-LDL uptake may be mediated by LOX-1 pathway. Anti-LOX-1 therapy may be a promising option for treatment of glomerulosclerosis.