Background Lipopolysaccharide (LPS) is widely recognized as a potent activator of monocytes/macrophages, and its effects include an altered production of key mediators, such as inflammatory cytokines and chemokines. The involvement of G i protein in mediating LPS effects has been demonstrated in murine macrophages and various cell types of human origin. Purpose The aim of the present work was to evaluate the potential of a G i -protein inhibitor encapsulated in liposomes in reducing the inflammatory effects induced by LPS in monocytes/macrophages. Materials and methods Guanosine 5′- O -(2-thiodiphosphate) (GOT), a guanosine diphosphate analog that completely inhibits G-protein activation by guanosine triphosphate and its analogs, was encapsulated into liposomes and tested for anti-inflammatory effects in LPS-activated THP1 monocytes or THP1-derived macrophages. The viability of monocytes/macrophages after incubation with different concentrations of free GOT or liposome-encapsulated GOT was assessed by MTT assay. MAPK activation and production of IL1β, TNFα, IL6, and MCP1 were assessed in LPS-activated monocytes/macrophages in the presence or absence of free or encapsulated GOT. In addition, the effect of free or liposome-encapsulated GOT on LPS-stimulated monocyte adhesion to activated endothelium and on monocyte chemotaxis was evaluated. Results We report here that GOT-loaded liposomes inhibited activation of MAPK and blocked the production of the cytokines IL1β, TNFα, IL6, and MCP1 induced by LPS in monocytes and macrophages. Moreover, GOT encapsulated in liposomes reduced monocyte adhesion and chemotaxis. All demonstrated events were in contrast with free GOT, which showed reduced or no effect on monocyte/macrophage activation with LPS. Conclusion This study demonstrates the potential of liposomal GOT in blocking LPS proinflammatory effects in monocytes/macrophages.

Chemokines are critically involved in the development of chronic inflammatory-associated diseases such as atherosclerosis. We hypothesised that targeted delivery of compounds to the surface of activated endothelial cells (EC) interferes with chemokine/receptor interaction and thereby efficiently blocks inflammation. We developed PEGylated target-sensitive liposomes (TSL) encapsulating a CCR2 antagonist (Teijin compound 1) coupled with a specific peptide recognized by endothelial VCAM-1 (Vp-TSL-Tj). TSL were characterized for size (by dynamic light scattering), the amount of peptide coupled at the surface of liposomes and Teijin release (by HPLC). We report that Vp-TSL-Tj binds specifically to activated EC in vitro and in vivo, release the entrapped Teijin and prevent the transmigration of monocytes through activated EC. This is the first evidence that nanocarriers transporting and releasing chemokine inhibitors at specific pathological sites reduce the chemokine-dependent inflammatory process. Abstract:Chemokines are critically involved in the development of chronic inflammatory-associated diseases such as atherosclerosis. We hypothesised that targeted delivery of compounds to the surface of activated endothelial cells (EC) interferes with chemokine/receptor interaction and thereby efficiently blocks inflammation. We developed PEGylated target-sensitive liposomes (TSL) encapsulating a CCR2 antagonist (Teijin compound 1) coupled with a specific peptide recognized by endothelial VCAM-1 (Vp-TSL-Tj). TSL were characterized for size (by dynamic light scattering), the amount of peptide coupled at the surface of liposomes and Teijin release (by HPLC). We report that Vp-TSL-Tj binds specifically to activated EC in vitro and in vivo, release the entrapped Teijin and prevent the transmigration of monocytes through activated EC. This is the first evidence that nanocarriers transporting and releasing chemokine inhibitors at specific pathological sites reduce the chemokine-dependent inflammatory process.

There is a stringent need to find means for risk stratification of coronary artery diseases (CAD) patients. We aimed at identifying alterations of plasma high-density lipoproteins (HDL) components and their validation as dysfunctional HDL that could discriminate between acute coronary syndrome (ACS) and stable angina (SA) patients. HDL2 and HDL3 were isolated from CAD patients’ plasma and healthy subjects. ApolipoproteinAI (apoAI), apoAII, apoCIII, malondialdehyde (MDA), myeloperoxidase (MPO), ceruloplasmin and paraoxonase1 (PON1) were assessed. The anti-inflammatory potential of HDL subfractions was tested by evaluating the secreted inflammatory molecules of tumor necrosis factor α-activated endothelial cells (EC) upon co-incubation with HDL2 or HDL3. We found in ACS versus SA patients: 40% increased MPO, MDA, apoCIII in HDL2 and HDL3, 35% augmented apoAII in HDL2, and in HDL3 increased ceruloplasmin, decreased apoAII (40%) and PON1 protein and activity (15% and 25%). Co-incubation of activated EC with HDL2 or HDL3 from CAD patients induced significantly increased levels of secreted inflammatory molecules, 15–20% more for ACS versus SA. In conclusion, the assessed panel of markers correlates with the reduced anti-inflammatory potential of HDL subfractions isolated from ACS and SA patients (mostly for HDL3 from ACS) and can discriminate between these two groups of CAD patients.

Our data support the administration of probiotics to humans because of their hypolipidemic (through decreasing intestinal NPC1L1 and MTTP) and antioxidant effects (stimulating HDL-associated paraoxonase-1).

Atherosclerosis is the main process behind cardiovascular diseases (CVD), maladies which continue to be responsible for up to 70% of death worldwide. Despite the ongoing development of new and potent drugs, their incomplete efficacy, partial intolerance and numerous side effects make the search for new alternatives worthwhile. The focus of the scientific world turned to the potential of natural active compounds to prevent and treat CVD. Essential for effective prevention or treatment based on phytochemicals is to know their mechanisms of action according to their bioavailability and dosage. The present review is focused on the latest data about phenolic compounds and aims to collect and correlate the reliable existing knowledge concerning their molecular mechanisms of action to counteract important risk factors that contribute to the initiation and development of atherosclerosis: dyslipidemia, and oxidative and inflammatory-stress. The selection of phenolic compounds was made to prove their multiple benefic effects and endorse them as CVD remedies, complementary to allopathic drugs. The review also highlights some aspects that still need clear scientific explanations and draws up some new molecular approaches to validate phenolic compounds for CVD complementary therapy in the near future.In the last decade the scientific researchers turned their attention to phytochemicals, as effective, safe and low-cost natural bioactive compounds for CVD treatment.Dyslipidemia consists of increased blood concentrations of total cholesterol (TC), low density lipoproteins-cholesterol (LDL-C) and/or triglycerides (TG), and decreased high density lipoproteins-cholesterol (HDL-C) [6]. The lipid metabolism is complex and the candidate mechanisms that could generate dyslipidemia include: (i) excessive dietary lipid absorption in the small intestine; (ii) packing of exogenous lipids with cholesterol and fatty acids produced de novo in the liver and their secretion as very low density lipoproteins (VLDL); (iii) hydrolysis of TG from VLDL by lipases and their conversion into LDL, which are taken up by the peripheral tissues through LDL receptor (LDL-R) and scavenger receptors; (iv) diminished production of HDL by the liver and small intestine, thereby decreasing reverse cholesterol transport (RCT) from the peripheral tissues to the liver; (v) lowered excess cholesterol excretion from the liver into gallbladder or to the intestinal lumen through the ATP-binding cassette G5 and G8 transporters (ABCG5/G8) that facilitate trans-intestinal cholesterol efflux (TICE). Dyslipidemia is associated with the accumulation of LDL in the sub-endothelium of the artery wall. At this site, LDL undergoes oxidative modifications (oxLDL) that trigger inflammatory responses, and is taken up by the monocyte-derived macrophages infiltrated in the sub-endothelium which thus become lipid-loaded foam cells, the hallmark of atheroma development [7]. Until now, the most effective lipid-lowering treatment for hyperlipidemic patients was the statin therapy. But recen...

Type 2 Diabetes Mellitus is a worldwide epidemic, and its atherosclerotic complications produce morbidity and mortality in affected patients. It is known that the vascular cell adhesion molecule-1 (VCAM-1) levels are increased in the sera of diabetic patients. Our aim was to investigate the impact of the endoplasmic reticulum stress (ERS) in VCAM-1 expression and secretion in human endothelial cells (HEC) exposed to glycated low-density lipoproteins (gLDL). The results showed that 24 h incubation of HEC with gLDL induces (i) stimulation of VCAM-1 expression and secretion, determining increased monocyte adhesion to HEC; (ii) RAGE up-regulation and free cholesterol loading; (iii) ERS activation (increased eIF2α phosphorylation and CHOP mRNA levels, and decreased GRP78 protein expression); and (iv) oxidative stress [increased levels of reactive oxygen species (ROS) and glutamate cysteine ligase catalytic unit gene expression]. Treatment of gLDL-exposed HEC with ERS inhibitors, salubrinal (Sal) and sodium phenylbutyrate (PBA), decreased intracellular ROS. Incubation of gLDL-exposed cells with the anti-oxidant N-acetyl-cysteine (NAC) reduced ERS, revealed by decreased eIF2α phosphorylation and CHOP gene expression and increased GRP78 expression, thus validating the interconnection between ERS and oxidative stress. Sal, PBA, NAC and inhibitors of p38 MAP kinase and NF-kB induced the decrease of VCAM-1 expression and of the ensuing monocyte adhesion induced by gLDL. In conclusion, in HEC, gLDL stimulate the expression of cellular VCAM-1, the secretion of soluble VCAM-1, and the adhesion of monocytes through mechanisms involving p38 MAP kinase and NF-kB signalling pathways activated by RAGE, ERS and oxidative stress, thus contributing to diabetic atherosclerosis.

Cell-penetrating peptides-functionalized CmLN have superior characteristics compared to their non-functionalized counterparts: are more efficiently internalized by the cells, produces anti-inflammatory effects in HEC and when administrated intravenously in mice exhibit increased accumulation in the liver and the lungs, suggesting their potential therapeutic applications in different inflammatory pathologies localized in the liver or the lungs.

Type 2 diabetes mellitus is a worldwide epidemic and its atherosclerotic complications determine the high morbidity and mortality of diabetic patients. Caffeic acid (CAF), a phenolic acid present in normal diets, is known for its antioxidant properties. The aim of this study was to investigate CAF's anti-inflammatory properties and its mechanism of action, using cultured human endothelial cells (HEC) incubated with glycated low-density lipoproteins (gLDL). Levels of the receptor for advanced glycation end-products (RAGE), inflammatory stress markers (C reactive protein, CRP; vascular cell adhesion molecule-1, VCAM-1; monocyte chemoattractant protein-1, MCP-1), and oxidative stress and endoplasmic reticulum stress (ERS) markers were evaluated in gLDL-exposed HEC, in the presence/absence of CAF. RAGE silencing or blocking, specific inhibitors for oxidative stress (apocynin, N-acetyl-cysteine), and ERS (salubrinal) were used. The results showed that: (i) gLDL induced CRP synthesis and secretion through mechanisms involving NADPH oxidase-dependent oxidative stress and ERS in HEC; (ii) gLDL-RAGE interaction, oxidative stress, and ERS stimulated the secretion of VCAM-1 and MCP-1 in HEC; and (iii) CAF reduced the secretion of CRP, VCAM-1, and MCP-1 in gLDL-exposed HEC by inhibiting RAGE expression, oxidative stress, and ERS. In conclusion, CAF might be a promising alternative to ameliorate a wide spectrum of disorders due to its complex mechanisms of action resulting in anti-inflammatory and antioxidative properties. © 2017 BioFactors, 43(5):685-697, 2017.