Atherosclerosis and cancer are chronic diseases considered two of the main causes of death all over the world. Taking into account that both diseases are multifactorial, they share not only several important molecular pathways but also many ethiological and mechanistical processes from the very early stages of development up to the advanced forms in both pathologies. Factors involved in their progression comprise genetic alterations, inflammatory processes, uncontrolled cell proliferation and oxidative stress, as the most important ones. The fact that external effectors such as an infective process or a chemical insult have been proposed to initiate the transformation of cells in the artery wall and the process of atherogenesis, emphasizes many similarities with the progression of the neoplastic process in cancer. Deregulation of cell proliferation and therefore cell cycle progression, changes in the synthesis of important transcription factors as well as adhesion molecules, an alteration in the control of angiogenesis and the molecular similarities that follow chronic inflammation, are just a few of the processes that become part of the phenomena that closely correlates atherosclerosis and cancer. The aim of the present study is therefore, to provide new evidence as well as to discuss new approaches that might promote the identification of closer molecular ties between these two pathologies that would permit the recognition of atherosclerosis as a pathological process with a very close resemblance to the way a neoplastic process develops, that might eventually lead to novel ways of treatment.

Metabolic overload by saturated fatty acids (SFA), which comprises β-cell function, and impaired glucose-stimulated insulin secretion are frequently observed in patients suffering from obesity and type 2 diabetes mellitus. The increase of intracellular Ca2+ triggers insulin granule release, therefore several mechanisms regulate Ca2+ efflux within the β-cells, among others, the plasma membrane Ca2+-ATPase (PMCA). In this work, we describe that lipotoxicity mediated mainly by the saturated palmitic acid (PA) (16C) is associated with loss of protein homeostasis (proteostasis) and potentially cell viability, a phenomenon that was induced to a lesser extent by stearic (18C), myristic (14C) and lauric (12C) acids. PA was localized on endoplasmic reticulum, activating arms of the unfolded protein response (UPR), as also promoted by lipopolysaccharides (LPS)-endotoxins. In particular, our findings demonstrate an alteration in PMCA1/4 expression caused by PA and LPS which trigger the UPR, affecting not only insulin release and contributing to β-cell mass reduction, but also increasing reactive nitrogen species. Nonetheless, stearic acid (SA) did not show these effects. Remarkably, the proteolytic degradation of PMCA1/4 prompted by PA and LPS was avoided by the action of monounsaturated fatty acids such as oleic and palmitoleic acid. Oleic acid recovered cell viability after treatment with PA/LPS and, more interestingly, relieved endoplasmic reticulum (ER) stress. While palmitoleic acid improved the insulin release, this fatty acid seems to have more relevant effects upon the expression of regulatory pumps of intracellular Ca2+. Therefore, chain length and unsaturation of fatty acids are determinant cues in proteostasis of β-cells and, consequently, on the regulation of calcium and insulin secretion.

Liver regeneration is a compensatory hyperplasia produced by several stimuli that promotes proliferation in order to provide recovery of the liver mass and architecture. This process involves complex signalling cascades that receive feedback from autocrine and paracrine pathways, recognized by parenchymal as well as non‐parenchymal cells. Nowadays the dynamic role of lipids in biological processes is widely recognized; however, a systematic analysis of their importance during liver regeneration is still missing. Therefore, in this review we address the role of lipids including the bioactive ones such as sphingolipids, but with special emphasis on cholesterol. Cholesterol is not only considered as a structural component but also as a relevant lipid involved in the control of the intermediate metabolism of different liver cell types such as hepatocytes, hepatic stellate cells and Kupffer cells. Cholesterol plays a significant role at the level of specific membrane domains, as well as modulating the expression of sterol‐dependent proteins. Moreover, several enzymes related to the catabolism of cholesterol and whose activity is down regulated are related to the protection of liver tissue from toxicity during the process of regeneration. This review puts in perspective the necessity to study and understand the basic mechanisms involving lipids during the process of liver regeneration. On the other hand, the knowledge acquired in this area in the past years, can be considered invaluable in order to provide further insights into processes such as general organogenesis and several liver‐related pathologies, including steatosis and fibrosis.

Recently, pipecolic acid (PA) has been involved in the functioning of the GABAergic system. In the present work we have studied the effect of PA on GABA uptake and release in cerebral cortex slices. PA (100 microM) was able to increase the release of [3H]GABA (90%) stimulated by mild depolarization with 15 mM potassium. If during the labeling of the tissue with [3H]GABA, beta-alanine was present, PA also enhanced the release (42%). However, when nipecotic acid was present instead beta-alanine, no stimulation of [3H]GABA release by potassium was observed neither in the control nor in the presence of PA. Spontaneous release was not affected by PA in any of the experimental conditions tested. In uptake experiments, only when beta-alanine was present in the medium PA significantly diminished the uptake (36%) of [3H]GABA. These results suggest that the effect of PA is mostly at the presynaptic level, inhibiting the neuronal GABA uptake and/or enhancing its release.

The plasma membrane Ca2+ -ATPase (PMCA) is responsible for the fine, long-term regulation of the cytoplasmic calcium concentration by extrusion of this cation from the cell. Although the general kinetic mechanisms for the action of both, well coordinated hydrolytic activity and calcium transport are reasonably understood in the majority of cell types, due to the complex physiologic and biochemical characteristics shown by the hepatocyte, the study of this enzyme in this cell type has become a real challenge. Here, we review the various molecular aspects known to date to be associated with liver PMCA activity, and outline the strategies to follow for establishing the role of this enzyme in the overall physiology of the hepatocyte. In this way, we first concentrate on the basic biochemical aspects of liver cell PMCA, and place an important emphasis on expression of its molecular forms to finally focus on the critical hormonal regulation of the enzyme. Although these complex aspects have been studied mainly under normal conditions, the significance of PMCA in the calcium homeostasis of an abnormal liver cell is also reviewed.

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Atherosclerosis together with multiple sclerosis, psoriasis and rheumatoid arthritis can be used as examples of chronic inflammatory diseases associated with multifactorial components that evolve over the years. Nevertheless, an important difference between these diseases relies on the fact that atherosclerosis develops from early ages where inflammation dominates the very beginning of the disease. This review highlights the inflammatory nature of atherosclerosis and the role the immune system plays in the process of atherogenesis. Although treatment of atherosclerosis has been for years based on lipid-lowering therapies reducing a series of risk factors, the degree of success has been only limited because cardiovascular complications related to the evolution of atherosclerotic lesions continue to appear in the population worldwide. In this sense, alternative treatments for atherosclerosis have come into play where both innate and adaptive immunity have been proposed to modulate atherosclerosis-associated inflammatory phenomena. When tested for their atheroprotective properties, several immunogens have been studied through passive and active immunization with good results and, therefore, the strategy through vaccination to control the disease has been made possible. Many experimental pre-clinical studies demonstrating proof of concept that vaccination using DNA and protein with an effective use of adjuvants and the optimal route of administration now provide a tangible new therapeutic approach that sets the stage for several of these vaccines to be tested in large, randomized, long-term clinical studies. A vaccine ready for human use will only be accomplished through the close association between academia, regulatory government organizations and private industry, allowing the reality of a simple and successful therapy to reduce atherosclerosis and its severe clinical complications.

BackgroundAlthough nowadays it is well known that the human transcriptome can importantly vary according to external or environmental condition, the reflection of this concept when studying oxidative stress and its direct relationship with gene expression profiling during the process of atherogenesis has not been thoroughly achieved.ObjectiveThe ability to analyze genome-wide gene expression through transcriptomics has shown that the genome responds dynamically to diverse stimuli. Here, we describe the transcriptome of human vascular smooth muscle cells (hVSMC) stimulated by native and oxidized low-density lipoprotein (nLDL and oxLDL respectively), with the aim of assessing the early molecular changes that induce a response in this cell type resulting in a transcriptomic transformation. This expression has been demonstrated in atherosclerotic plaques in vivo and in vitro, particularly in the light of the oxidative modification hypothesis of atherosclerosis.Approach and ResultsTotal RNA was isolated with TRIzol reagent (Life Technologies) and quality estimated using an Agilent 2100 bioanalyzer. The transcriptome of hVSMC under different experimental conditions (1,5 and 24 hours for nLDL and oxLDL) was obtained using the GeneChip Human Gene 1.0 ST (Affymetrix) designed to measure gene expression of 28,869 well-annotated genes. A fixed fold-change cut-off corresponding to ± 2 was used to identify genes exhibiting the most significant variation and statistical significance (P< 0.05), and 8 genes validated by qPCR using Taqman probes.Conclusions10 molecular processes were significantly affected in hVSMC: Apoptosis and cell cycle, extracellular matrix remodeling, DNA repair, cholesterol efflux, cGMP biosynthesis, endocytic mechanisms, calcium homeostasis, redox balance, membrane trafficking and finally, the immune response to inflammation. The evidence we present supporting the hypothesis for the involvement of oxidative modification of several processes and metabolic pathways in atherosclerosis is strengthen by the fact that gene expression patterns obtained when hVSMC are incubated for a long period of time in the presence of nLDL, correspond very much the same as when cells are incubated for a short period of time in the presence of chemically modified oxLDL. Our results indicate that under physiological conditions and directly related to specific environmental conditions, LDL particles most probably suffer chemical modifications that initially serve as an alert signal to overcome a harmful stimulus that with time might get transformed to a pathological pattern and therefore consolidate a pathological condition.