COX-2 and atherosclerosis

Genetics of inflammation in age-related atherosclerosis: its relevance to pharmacogenomics

In response to tissue injury elicited by trauma or infection, the inflammatory response, as a complex network of molecular and cellular interactions, sets an answer directed to facilitate a return to physiological homeostasis and tissue repair. The role of the genetic background and the subsequent predisposition toward the extent of the inflammatory response is determined by gene variability encoding endogenous mediators involved in the inflammatory pathway. Due to its clinical relevance, the genetics of inflammation in aging will be studied using an inflammatory disease like atherosclerosis as an example. Several studies have reported a significant difference in distribution, between patients and controls, of genes involved in inflammation. So, the proinflammatory alleles are underrepresented in control subjects and overrepresented in patients affected by atherosclerosis. These studies will allow building a risk profile that potentially enables the early identification of individuals susceptible to disease and the possible design or use of drug at the right dose for a desired effect, that is, a pharmacogenomic approach for this disease.

Polymorphisms of pro-inflammatory genes and Alzheimer's disease risk: A pharmacogenomic approach

Clinically and pathologically Alzheimer's disease (AD) represents a sequential progressive neurodegenerative disorder. AD is etiologically heterogeneous and accounts for a majority of dementia in western societies. Inflammation clearly occurs in pathologically vulnerable regions of the AD brain and the search for genetic factors influencing the pathogenesis of AD has lead to the identification of numerous gene polymorphisms that might act as susceptibility modifiers. Accordingly, several reports have indicated that the risk of AD is substantially influenced by several genetic polymorphisms in the promoter region, or other untranslated regions, of genes encoding inflammatory mediators, although not all the studies were replied. Here, we review several data suggesting that inflammatory genetic variation may contribute to AD susceptibility. All together this information may represent the basis both for future recognition of individuals at risk and for the pharmacogenomic driving of drug responsiveness.

Prostanoids in nociception and pain

Prostaglandins are lipid mediators produced by cyclooxygenases from arachidonic acid, which serve pivotal functions in inflammation and pain. Inhibition of their production is the major analgesic mechanism of action of non-steroidal anti-inflammatory drugs (NSAIDs)-but also the source of most of their unwanted effects. While the development of selective inhibitors of inducible cyclooxygenase (COX)-2 (so called coxibs) has greatly reduced gastrointestinal side effects, the recent disappointment about a potential cardiovascular toxicity of COX-2-selective inhibitors has boosted interest in alternative targets. The discovery of several prostaglandin synthases and of distinct prostaglandin receptors has unraveled an unforeseen diversity within the prostanoid synthetic pathway. Behavioral and electrophysiological work in particular with genetically engineered mice meanwhile provides new clues to the role of different prostaglandins, prostaglandin synthases and prostaglandin receptors in pain pathways.

Inflammatory networks in ageing, age-related diseases and longevity

Inflammation is considered a response set by the tissues in response to injury elicited by trauma or infection. It is a complex network of molecular and cellular interactions that facilitates a return to physiological homeostasis and tissue repair. The individual response against infection and trauma is also determined by gene variability. Ageing is accompanied by chronic low-grade inflammation state clearly showed by 2-4-fold increase in serum levels of inflammatory mediators. A wide range of factors has been claimed to contribute to this state; however, the most important role seems to be played by the chronic antigenic stress, which affects immune system thorough out life with a progressive activation of macrophages and related cells. This pro-inflammatory status, interacting with the genetic background, potentially triggers the onset of age-related inflammatory diseases as atherosclerosis. Thus, the analysis of polymorphisms of the genes that are key nodes of the natural immunity response might clarify the patho-physiology of age-related inflammatory diseases as atherosclerosis. On the other hand, centenarians are characterized by marked delay or escape from age-associated diseases that, on average, cause mortality at earlier ages. In addition, centenarian offspring have increased likelihood of surviving to 100 years and show a reduced prevalence of age-associated diseases, as cardiovascular disease (CVD) and less prevalence of cardiovascular risk factors. So, genes involved in CVD may play an opposite role in human longevity. Thus, the model of centenarians can be used to understand the role of these genes in successful and unsuccessful ageing. Accordingly, we report the results of several studies in which the frequencies of pro-inflammatory alleles were significantly higher in patients affected by infarction and lower in centenarians whereas age-related controls displayed intermediate values. These findings point to a strong relationship between the genetics of inflammation, successful ageing and the control of cardiovascular disease at least in men, in which these studies were performed. These data are also briefly discussed in the light of antagonistic pleiotropy theory and in order to pursuit a pharmacogenomics approach.

Role of Proinflammatory Alleles in Longevity and Atherosclerosis: Results of Studies Performed on -1562C/T MMP-9 in Centenarians and Myocardial Infarction Patients from Sicily

Centenarians are characterized by marked delay or escape from age-associated diseases that cause mortality at earlier ages. Jointly, atherosclerosis and its complications, such as myocardial infarction (AMI), significantly contribute to mortality in the elderly. Inflammation is a key component of atherosclerosis and inflammatory genes are good candidates for the risk of the development of atherosclerosis. Genetic traits contribute to the risk of AMI and allelic variations in inflammatory genes should boost the risk of disease. If proinflammatory genotypes significantly contribute to the risk of AMI, alleles associated with disease susceptibility should not be included in the genetic background favoring longevity. Hence, genotypes of natural immunity should play an opposite role in atherosclerosis and longevity. Metalloproteinase (MMPs) are involved in tissue remodeling and therefore play a remarkable role in inflammation-based disease. MMPs are a family of Zn(2+)-dependent enzymes with proteolytic activity against connective tissue proteins such as collagens, proteoglycans, and elastin, which appear to play important roles in the development and progression of the atherosclerotic lesion. There is evidence indicating a role played by the MMPs in the weakening of atherosclerotic plaque which predisposes to lesion disruption. In this study we performed a genetic study on -1562C/T MMP-9 single nucleotide polymorphism (SNP) in order to discern a possible role in AMI. We analyzed the distribution of this SNP in 115 AMI patients, 123 controls, and 34 centenarians from Sicily. We found no significant differences in the genetic distribution and allelic frequency of -1562C/T MMP-9 SNP between the studied groups. The present results are not in agreement with our previous findings, strengthening our hypothesis that genetic background protection against cardiovascular disease is a relevant component of the longevity trait, at least in the generation of Italian male centenarians under study. However, present results do not exclude that differential expression of MMP-9 playing an opposite role in AMI and longevity because other kinds of regulation might be more relevant than those linked to the SNP under study.