TRIF Regulates BIC/miR-155 via the ERK Signaling Pathway to Control the ox-LDL-Induced Macrophage Inflammatory Response

Monocytes reprogrammed by 4-PBA potently contribute to the resolution of inflammation and atherosclerosis

Background

Chronic inflammation initiated by inflammatory monocytes underlies the pathogenesis of atherosclerosis. However, approaches that can effectively resolve chronic low-grade inflammation targeting monocytes are not readily available. The small chemical compound 4-phenylbutyric acid (4-PBA) exhibits broad anti-inflammatory effects in reducing atherosclerosis. Selective delivery of 4-PBA reprogrammed monocytes may hold novel potential in providing targeted and precision therapeutics for the treatment of atherosclerosis.

Methods

Systems analyses integrating single-cell RNA-sequencing and complementary immunological approaches characterized key resolving characteristics as well as defining markers of reprogrammed monocytes trained by 4-PBA. Molecular mechanisms responsible for monocyte reprogramming was assessed by integrated biochemical and genetic approaches. The inter-cellular propagation of homeostasis resolution was evaluated by co-culture assays with donor monocytes trained by 4-PBA and recipient naïve monocytes. The in vivo effects of monocyte resolution and atherosclerosis prevention by 4-PBA were assessed with the high fat diet-fed ApoE -/- mouse model with i.p. 4-PBA administration. Furthermore, the selective efficacy of 4-PBA trained monocytes were examined by i.v. transfusion of ex vivo trained monocytes by 4-PBA into recipient high fat diet-fed ApoE -/- mice.

Results

In this study, we found that monocytes can be potently reprogrammed by 4-PBA into an immune-resolving state characterized by reduced adhesion and enhanced expression of anti-inflammatory mediator CD24. Mechanistically, 4-PBA reduced the expression of ICAM-1 via reducing peroxisome stress and attenuating SYK-mTOR signaling. Concurrently, 4-PBA enhanced the expression of resolving mediator CD24 through promoting PPARγ neddylation mediated by TOLLIP. 4-PBA trained monocytes can effectively propagate anti-inflammation activity to neighboring monocytes through CD24. Our data further demonstrated that 4-PBA trained monocytes effectively reduce atherosclerosis pathogenesis when administered in vivo .

Conclusion

Our study describes a robust and effective approach to generate resolving monocytes, characterizes novel mechanisms for targeted monocyte reprogramming, and offers a precision-therapeutics for atherosclerosis based on delivering reprogrammed resolving monocytes.

Inflammatory microRNAs in cardiovascular pathology: another brick in the wall

The regulatory role of microRNAs (miRNAs) is mainly mediated by their effect on protein expression and is recognized in a multitude of pathophysiological processes. In recent decades, accumulating evidence has interest in these factors as modulatory elements of cardiovascular pathophysiology. Furthermore, additional biological processes have been identified as new components of cardiovascular disease etiology. In particular, inflammation is now considered an important cardiovascular risk factor. Thus, in the present review, we will focus on the role of a subset of miRNAs called inflamma-miRs that may regulate inflammatory status in the development of cardiovascular pathology. According to published data, the most representative candidates that play functional roles in thromboinflammation are miR-21, miR-33, miR-34a, miR-146a, miR-155, and miR-223. We will describe the functions of these miRNAs in several cardiovascular pathologies in depth, with specific emphasis on the molecular mechanisms related to atherogenesis. We will also discuss the latest findings on the role of miRNAs as regulators of neutrophil extracellular traps and their impact on cardiovascular diseases. Overall, the data suggest that the use of miRNAs as therapeutic tools or biomarkers may improve the diagnosis or prognosis of adverse cardiovascular events in inflammatory diseases. Thus, targeting or increasing the levels of adequate inflamma-miRs at different stages of disease could help mitigate or avoid the development of cardiovascular morbidities.

Oxidative Stress and Inflammation in Cardiovascular Diseases and Cancer: Role of Non-coding RNAs

High oxidative stress, Th1/Th17 immune response, M1 macrophage inflammation, and cell death are associated with cardiovascular diseases. Controlled oxidative stress, Th2/Treg anti-tumor immune response, M2 macrophage inflammation, and survival are associated with cancer. MiR-21 protects against cardiovascular diseases but may induce tumor growth by retaining the anti-inflammatory M2 macrophage and Treg phenotypes and inhibiting apoptosis. Down-regulation of let-7, miR-1, miR-9, miR-16, miR-20a, miR-22a, miR-23a, miR-24a, miR-26a, miR-29, miR-30a, miR-34a, miR-124, miR-128, miR-130a, miR-133, miR-140, miR-143-145, miR-150, miR-153, miR-181a, miR-378, and miR-383 may aid cancer cells to escape from stresses. Upregulation of miR-146 and miR-223 may reduce anti-tumor immune response together with miR-21 that also protects against apoptosis. MiR-155 and silencing of let-7e, miR-125, and miR-126 increase anti-tumor immune response. MiR expression depends on oxidative stress, cytokines, MYC, and TGF-β, and expression of silencing lncRNAs and circ-RNAs. However, one lncRNA or circ-RNA may have opposite effects by targeting several miRs. For example, PVT1 induces apoptosis by targeting miR-16a and miR-30a but inhibits apoptosis by silencing miR-17. In addition, levels of a non-coding RNA in a cell type depend not only on expression in that cell type but also on an exchange of microvesicles between cell types and tumors. Although we got more insight into the function of a growing number of individual non-coding RNAs, overall, we do not know enough how several of them interact in functional networks and how their expression changes at different stages of disease progression.

The Role of miR-155 in Nutrition: Modulating Cancer-Associated Inflammation

Nutrition plays an important role in overall human health. Although there is no direct evidence supporting the direct involvement of nutrition in curing disease, for some diseases, good nutrition contributes to disease prevention and our overall well-being, including energy level, optimum internal function, and strength of the immune system. Lately, other major, but more silent players are reported to participate in the body’s response to ingested nutrients, as they are involved in different physiological and pathological processes. Furthermore, the genetic profile of an individual is highly critical in regulating these processes and their interactions. In particular, miR-155, a non-coding microRNA, is reported to be highly correlated with such nutritional processes. In fact, miR-155 is involved in the orchestration of various biological processes such as cellular signaling, immune regulation, metabolism, nutritional responses, inflammation, and carcinogenesis. Thus, this review aims to highlight those critical aspects of the influence of dietary components on gene expression, primarily on miR-155 and its role in modulating cancer-associated processes.

Propofol Regulates the TLR4/NF-κB Pathway Through miRNA-155 to Protect Colorectal Cancer Intestinal Barrier

Surgery for colorectal cancer (CRC) can cause damage to the intestinal mucosal barrier and lead to bacterial invasion. This study mainly analyzed whether propofol (PPF) could protect the intestinal mucosal barrier damage caused by CRC surgery, and explored its molecular mechanism. A mouse CRC model was constructed using azomethane and dextran sulfate sodium. During anesthesia, continuous intravenous injection of PPF was used for intervention. The influences of PPF on intestinal mucosal permeability and bacterial invasion were detected. The levels of microRNA (miR)-155, Toll-like receptor 4 (TLR4)/NF-κB in the intestinal mucosa, and the location of miR-155 were detected by fluorescence in situ hybridization (FISH). Mouse macrophages were used to analyze the regulation of miR-155 on the secretion of inflammatory cytokines through the TLR4/NF-κB pathway. PPF treatment promoted the expression of tight junction protein in the intestinal mucosa, protected the intestinal barrier, inhibited the translocation of intestinal bacteria, and increased the level of the beneficial bacterium Lactobacillus on the mucosal surface. In addition, PPF treatment could inhibit the expression of miR-155, TLR4/NF-KB, and reverse inflammatory response. miR-155 was expressed in macrophages of intestinal mucosa tissue. Overexpression of miR-155 promoted the nuclear translocation of NF-κB and the expression of inflammatory cytokines in macrophages. The use of VIPER to inhibit TLR4 reversed the pro-inflammatory effects of miR-155. PPF might inhibit the activation of the NF-κB pathway by downregulating miR-155 expression, thereby reducing the secretion of inflammatory cytokines. This might be the mechanism by which PPF protected the intestinal barrier of CRC surgical model mice.

Effects of Bunao-Fuyuan decoction serum on proliferation and migration of vascular smooth muscle cells in atherosclerotic

Atherosclerosis (AS) is a chronic inflammatory disease, the main causes of which include abnormal lipid metabolism, endothelial injury, physical and chemical injury, hemodynamic injury, genetic factors and so on. These causes can lead to inflammatory injury of blood vessels and local dysfunction. Bunao-Fuyuan decoction (BNFY) is a traditional Chinese medicine compound that can treat cardiovascular and cerebrovascular diseases, but its effect on AS is still unknown. The aim of this study was to investigate the effect and mechanism of BNFY in proliferation and migration of vascular smooth muscle cells (VSMCs) on AS. At first, the expression of α-SMA protein in ox-LDL-induced VSMCs, which was detected by immunofluorescence staining and western blot. CCK-8 technique and cloning technique were used to detect the cell proliferation of ox-LDL-induced VSMCs after adding BNFY. Meanwhile, the expression of proliferating protein Ki67 was detected by immunofluorescence staining. Western blot was also used to detect the expression of proliferation-related proteins CDK2, CyclinE1 and P27. Flow cytometry was used to detect the effect of BNFY on cell cycle. The effects of BNFY on proliferation and migration of cells were detected by cell scratch test and Transwell. Western blot was used to detect the expression of adhesion factors ICAM1, VCAM1, muc1, VE-cadherin and RHOA/ROCK-related proteins in cells. We found that the expression of AS marker α-SMA protein increased significantly and cells shriveled and a few floated on the medium after induction of ox-LDL on VSCMs. The proliferation rate of ox-LDL VSMCs decreased significantly after adding different doses of BNFY, and BNFY can inhibit cell cycle. Meanwhile, we also found that cell invasion and migration rate were significantly inhibited and related cell adhesion factors ICAM1, VCAM1, muc1 and VE-cadherin were inhibited too by BNFY. Finally, we found that BNFY inhibited the expression of RHOA, ROCK1, ROCK2, p-MLC proteins in the RHOA/ROCK signaling pathway. Therefore, we can summarize that BNFY may inhibit the proliferation and migration of atherosclerotic vascular smooth muscle cells by inhibiting the activity of RHOA/ROCK signaling pathway.

MicroRNA-155 inhibits dengue virus replication by inducing heme oxygenase-1-mediated antiviral interferon responses

MicroRNAs (miRNAs) have been reported to directly alter the virus life cycle and virus-host interactions, and so are considered promising molecules for controlling virus infection. In the present study, we observed that miR-155 time-dependently downregulated upon dengue virus (DENV) infection. In contrast, exogenous overexpression of miR-155 appeared to limit viral replication in vitro, suggesting that the low levels of miR-155 would be beneficial for DENV replication. In vivo, overexpression of miR-155 protected ICR suckling mice from the life-threatening effects of DENV infection and reduced virus propagation. Further investigation revealed that the anti-DENV activity of miR-155 was due to target Bach1, resulting in the induction of the heme oxygenase-1 (HO-1)-mediated inhibition of DENV NS2B/NS3 protease activity, ultimately leading to induction of antiviral interferon responses, including interferon-induced protein kinase R (PKR), 2'-5'-oligoadenylate synthetase 1 (OAS1), OAS2, and OAS3 expression, against DENV replication. Collectively, our results provide a promising new strategy to manage DENV infection by modulation of miR-155 expression.

CD13 deficiency leads to increased oxidative stress and larger atherosclerotic lesions

BACKGROUND AND AIMS

Atherosclerosis is an inflammatory cardiovascular disorder characterized by accumulation of lipid-loaded macrophages in the intima. Prolonged accumulation leads to apoptosis of macrophages and eventually to progression of lesion development. Prevention of macrophage accumulation within the intima has been shown to reduce lesion formation. Since CD13 mediates trafficking of macrophages to sites of injury and repair, we tested the role of CD13 in atherosclerosis.

METHODS

CD13+/+Ldlr-/- and CD13-/-Ldlr-/- (low density lipoprotein receptor) mice were fed basal or high fat diet (HFD) for 9, 12 and 15 weeks. Mice were euthanized and aortic roots along with innominate arteries were analyzed for atherosclerotic lesions. Cellular mechanisms were determined in vitro using CD13+/+ and CD13-/- bone marrow derived macrophages (BMDMs) incubated with highly oxidized low-density lipoprotein (oxLDL).

RESULTS

At the 9 and 12 week time points, no differences were observed in the average lesion size, but at the 15 week time point, CD13-/-Ldlr-/- mice had larger lesions with exaggerated necrotic areas. CD13+/+ and CD13-/- macrophages endocytosed similar amounts of oxLDL, but CD13-/- macrophages generated higher amounts of oxidative stressors in comparison to CD13+/+ macrophages. This increased oxidative stress was due to increased nitric oxide production in oxLDL treated CD13-/- macrophages. Accumulated oxidative stress subsequently led to accelerated apoptosis and enhanced necrosis of oxLDL treated CD13-/- macrophages.

CONCLUSIONS

Contrary to our prediction, CD13 deficiency led to larger atherosclerotic lesions with increased areas of necrosis. Mechanistically, CD13 deficiency led to increased nitric oxide production and consequently, greater oxidative stress.