Objectives-We tested for synergy between pravastatin and D-4F by administering oral doses of each in combination that were predetermined to be ineffective when given as single agents. Methods and Results-The combination significantly increased high-density lipoprotein (HDL)-cholesterol levels, apolipoprotein (apo)A-I levels, paraoxonase activity, rendered HDL antiinflammatory, prevented lesion formation in young (79% reduction in en face lesion area; PϽ0.0001) and caused regression of established lesions in old apoE null mice (ie, mice receiving the combination for 6 months had lesion areas that were smaller than those before the start of treatment (Pϭ0.019 for en face lesion area; Pϭ0.004 for aortic root sinus lesion area). After 6 months of treatment with the combination, en face lesion area was 38% of that in mice maintained on chow alone; PϽ0.00004) with a 22% reduction in macrophage content in the remaining lesions (Pϭ0.001), indicating an overall reduction in macrophages of 79%. The combination increased intestinal apoA-I synthesis by 60% (Pϭ0.011). In monkeys, the combination also rendered HDL antiinflammatory. Key Words: atherosclerosis Ⅲ lipoproteins Ⅲ HDL Ⅲ apoA-I mimetic peptides Ⅲ statins S tatins and apolipoprotein (apo)A-I have similar antiinflammatory properties. 1 Ansell et al 2 reported that the inflammatory/antiinflammatory properties of high-density lipoprotein (HDL) identified patients with coronary heart disease (CHD) or CHD equivalents better than HDL-cholesterol levels. Treatment with 40 mg pravastatin daily for 6 weeks significantly improved the inflammatory/antiinflammatory properties of HDL in these patients. 2 However, even after treatment, 40% to 50% of the patients still had frankly pro-inflammatory HDL. 2 Moreover, after pravastatin only 4 of 26 patients achieved HDL that was antiinflammatory to the degree seen in 24 of 26 age-and gender-matched controls. 2 Conclusions-These

Abstract-Previous studies suggest that high-density lipoprotein and apoAI inhibit lipopolysaccharide (LPS)-induced inflammatory responses. The goal of the current study was to test the hypothesis that the apoAI mimetic peptide L-4F exerts antiinflammatory effects similar to apoAI. Pretreatment of human umbilical vein endothelial cells (HUVECs) with LPS induced the adhesion of THP-1 monocytes. Incubation of cells with LPS and L-4F (1 to 50 g/mL) reduced THP-1 adhesion in a concentration-dependent manner. This response was associated with a significant reduction in the synthesis of cytokines, chemokines, and adhesion molecules. L-4F reduced vascular cell adhesion molecule-1 expression induced by LPS or lipid A, whereas a control peptide (Sc-4F) showed no effect. In contrast to LPS treatment, L-4F did not inhibit IL-1␤-or tumor necrosis factor-␣-induced vascular cell adhesion molecule-1 expression. 1 Approximately 50% of patients in intensive care units develop severe sepsis, and the overall mortality rate of all affected patients is 29%. 1 Mortality is attributable, in large part, to the cytotoxic actions of lipopolysaccharide (LPS) (endotoxin), a component of the outer membrane of Gram-negative bacteria. LPS is composed of a core oligosaccharide, a repeating polysaccharide side chain, and the glycolipid moiety lipid A. 2 Proinflammatory and cytotoxic effects of LPS are mediated by lipid A. 3 LPS is released from bacterial membranes into the circulation where it interacts with lipopolysaccharide binding protein (LBP), a member of the superfamily of phospholipid binding proteins. LBP binds to lipid A and mediates the disaggregation of LPS to form an LBP-LPS complex. 4 LBP directs LPS to membrane-associated CD14 receptors (mCD14) on myeloid cells 5 including monocytes and neutrophils. mCD14 is a cell surface-anchored protein that facilitates the binding of LPS and activation of Toll-like receptor (TLR) 4 which acts as the cellular transducer of LPS action. 2,6 Plasma LPS-LBP may also interact with soluble CD14 to form a complex that activates TLRs on endothelial, epithelial, Kuppfer, and other cells. 7 By activating nuclear factor B-dependent signaling mechanisms, LPS stimulates the synthesis/release of inflammatory cytokines, which play an important role in the innate immune response. 8,9 Dysregulation of this response leads to the development of endothelial dysfunction, intravascular coagulation, pulmonary injury, multiple organ failure, and death.The acute-phase response to bacterial infection induces changes in plasma lipoprotein levels that are characterized by Original

Recent evidence indicates that inflammation may significantly contribute to the pathogenesis of Alzheimer’s disease (AD). Since the apo A-I mimetic peptide D-4F has been shown to inhibit atherosclerotic lesion formation and regress already existing lesions (in the presence of pravastatin) and the peptide also decreases brain arteriole inflammation, we undertook a study to evaluate the efficacy of oral D-4F co-administered with pravastatin on cognitive function and amyloid β (Aβ) burden in the hippocampus of APPSwe-PS1ΔE9 mice. Three groups of male mice were administered D-4F and pravastatin, Scrambled D-4F (ScD-4F, a control peptide) and pravastatin in drinking water, while drinking water alone served as control. The escape latency in the Morris Water Maze test was significantly shorter for the D-4F+statin administered animals compared to the other two groups. While the hippocampal region of the brain was covered with 4.2±0.5 and 3.8±0.6% of Aβ load in the control and ScD-4F+statin administered groups, in the D-4F+statin administered group Aβ load was only 1.6±0.1%. Furthermore, there was a significant decrease in the number of activated microglia (p<0.05 vs the other two groups) and activated astrocytes (p<0.05 vs control) upon oral D-4F+statin treatment. Inflammatory markers TNFα and IL-1β levels were decreased significantly in the D-4F+statin group compared to the other two groups (for IL-1β p<0.01 vs the other two groups and for TNF-α p<0.001 vs control) and the expression of MCP-1 were also less in D-4F+statin administered group compared to the other two groups. These results suggest that the apo A-I mimetic peptide inhibits amyloid β deposition and improves cognitive function via exerting anti-inflammatory properties in the brain.

Recently, attention has been focused on pharmacological treatments that increase HDL cholesterol to prevent coronary artery disease. Despite three decades of extensive research of human apolipoprotein A-I (apoA-I), the major protein component of HDL, the molecular basis for its antiatherogenic and anti-inflammatory functions remain elusive. Another protein component of HDL, apoA-II, has structural features similar to those of apoA-I but does not possess atheroprotective properties. To understand the molecular basis for the effectiveness of apoA-I, we used model synthetic peptides. We designed analogs of the class A amphipathic helical motif in apoA-I that is responsible for solubilizing phospholipids. None of these analogs has sequence homology to apoA-I, but all are similar in their lipid-associating structural motifs. Although all of these peptide analogs interact with phospholipids to form peptide:lipid complexes, the biological properties of these analogs are different. Physical-chemical and NMR studies of these peptides have enabled the delineation of structural requirements for atheroprotective and anti-inflammatory properties in these peptides. It has been shown that peptides that interact strongly with lipid acyl chains do not have antiatherogenic and anti-inflammatory properties. In contrast, peptides that associate close to the lipid head group (and hence do not interact strongly with the lipid acyl chain) are antiatherogenic and anti-inflammatory. Understanding the structure and function of apoA-I and HDL through studies of the amphipathic helix motif may lead to peptide-based therapies for inhibiting atherosclerosis and other related inflammatory lipid disorders.