+10 T/C polymorphisms in the gene of transforming growth factor-beta1 are associated with neurodegeneration and its clinical evolution.

Transforming growth factor-beta1 (TGF-beta1) acts as an immunosuppressant by inhibiting the expression of several pro-inflammatory cytokines. Its gene contains single nucleotide polymorphisms (SNPs) at codon +10 (T-->C) and +25 (G-->C) that appear to influence the level of expression of TGF-beta1. We investigated these SNPs in 198 healthy controls (HC), 193 patients with Alzheimer's disease (AD) and 48 patients with mild cognitive impairment (MCI). Among the latter, after a 4-year follow-up, 21 were diagnosed as AD (MCI-->AD) while 18 did not progress (stable MCI). We observed that both the +10 C allele and the CC genotype were over-represented in AD when compared to HC. These variants significantly raised the risk of disease independently of the status of apolipoprotein E4. The CC genotype was also over-expressed in MCI, especially in MCI-->AD. These results suggest that TGF-beta1 may be one of the early markers involved in the inflammatory mechanisms underlying the pathogenesis of AD.

Natural aging, expression of fibrosis-related genes and collagen deposition in rat lung.

Aging lung is characterized by morpho-structural modifications, including progressive fibrosis, that lead to an altered function. Here we provide a comprehensive description of lung collagen expression and metabolism during natural aging of rats. Peribronchial collagen increased significantly in the oldest animals (p=0.05 2- vs. 6- and 19-month-old rats), as a consequence of Collagen-I and Collagen-III (COL-I, COL-III) protein accumulation (p<0.05 in 6-, 12- and 19-month-old rats versus the youngest). No changes in fibronectin (FN) protein expression and in COL-III and transforming grow factor beta-1 (TGFbeta-1) mRNA expression were observed. Conversely the transcription activity of the COL-I gene was overexpressed in the oldest animals (p<0.05). In the aged rats, the activity of lung matrix metalloproteinases (MMP), MMP-1 and MMP-2, dropped significantly (p<0.05), whilst MMP-9 levels were slightly decreased. These changes were associated with a concomitant increase of tissue inhibitors of MMP (TIMP-1 and TIMP-2). All together, these results suggest that, during natural aging, collagen accumulation in the lung and its progressive fibrosis are mainly due to a reduced proteolytic activity of MMP, in which TIMP-1 and -2 seem to be the major regulating factors.

I405V polymorphism of the cholesteryl ester transfer protein (CETP) gene in young and very old people.

This study was designed to analyse the prevalence of I405V polymorphism in the cholesteryl ester transfer protein (CETP) gene, the CETP serum concentration, the lipoprotein profile, and certain clinical end-points in two populations, one young and another of very old people. We recruited 100 healthy young people (median age 31 years) and 100 very old people (median age 89 years) and analysed their DNA for the presence of I405V polymorphism. The frequency of the VV genotype in very old people was more than double that in the young population. Subjects with this genotype had lower serum concentrations of CETP. Young people with the V/V genotype had a less atherogenic lipoprotein profile (lower total cholesterol, LDL cholesterol, Apo B, and Apo B/Apo A-I ratio) than those with the I/V or I/I genotypes. The older subjects, particularly the older women with the V/V genotype, had larger LDL than the young people. The prevalence of clinical endpoints was much lower among the very old people with the V/V genotype. In conclusion, the V/V genotype of the I405V CETP polymorphism is more frequent among very old people than young ones, and is associated with a lower incidence of vascular damage.

[I405V polymorphism of the cholesteryl ester transfer protein gene in young and very old individuals]. / Il polimorfismo I405V del gene della proteina di trasferimento degli esteri del colesterolo nei giovani e nei grandi vecchi.

This study was designed to analyze the prevalence of I405V polymorphism in the cholesteryl ester transfer protein (CETP) gene, the blood CETP concentration, the lipoprotein pattern and certain clinical endpoints in two populations, one of young and another of very old individuals. We recruited 100 healthy young adults (median age 31 years) and 100 very old subjects (median age 89 years) and analyzed their DNA for the presence of variants V and I of the CETP gene. Subjects with the V/V genotype had lower serum concentrations of CETP. The frequency of this genotype in the very old was more than double that in the young population. Young adults with the V/V genotype had a less atherogenic lipoprotein pattern [lower total and LDL cholesterol levels, lower apolipoprotein (Apo) B levels, and a lower Apo B/Apo A-I ratio] than those with the I/V or I/I genotypes. The very old subjects, particularly those with the V/V genotype, had larger LDL than the young adults. The prevalence of clinical endpoints was much lower among the very old subjects with the V/V genotype.

Interleukin-10 and interleukin-6 gene polymorphisms as risk factors for Alzheimer's disease.

In the pathogenesis of Alzheimer disease (AD), it has been proposed that the anti-inflammatory interleukins such as IL-10 regulate beta-amyloid-induced microglial inflammatory responses inhibiting the proinflammatory cytokine IL-6. Since the promoters of the IL-10 and IL-6 genes show single nucleotide polymorphisms (SNPs) (IL-10: -1082 G --> A; IL-6: -174 G --> C), we investigated these SNPs and cytokine production by peripheral blood mononuclear cells in 65 AD patients and 65 controls (HC). In AD there was a significant increase of the -1082A IL-10 allele (P=0.009) and a decrease of -1082GG genotype (P=0.019). The frequency of the GG IL-6 genotype in AD was lower and the C allele significantly higher (P <0.005). The co-occurrence of IL-10 A and IL-6 C alleles significantly raised the odds ratio (OR 11.2, confidence interval: CI 1.3-97.3; P <0.05) independently of apolipoprotein E4 (adjusted OR 10.3, CI 1-108; P <0.05). Only amyloid-stimulated IL-10 production differed between the groups (P=0.023). These results raise questions regarding the inflammatory theory in AD, pointing to a pivotal role of IL-10 and IL-6 and a selective alteration in this network.

Adenosine A1 and A2A receptor cross-talk during ageing in the rat myocardium.

Adenosine (Ado), a naturally occurring autacoid, exerts cardioprotective effects against myocardial ischemia and reperfusion injury, through activation of its receptors type 1 (A1) and 2A (A2A). Since ageing involves a complex change in these effects, we evaluated A1 and A2A gene expression in left (LV) and right ventricle (RV) from 2-, 5-, 12-, and 21-month-old Sprague-Dawley rats. LV end-diastolic (EDD) and end-systolic (ESD) internal dimensions (mm) and LV fractional shortening (FS, %) were measured by M-mode echocardiography. Senescence was associated with a reduction in FS (42+/-1, 38+/-2, 39+/-2 and 35+/-2, in 2-, 5-, 12- and 21-month-old rats; p<0.02) and increases in EDD (7.5+/-0.2, 8.1+/-0.2, 8.5+/-0.2 and 8.8+/-0.2; p<0.001) and ESD (4.2+/-0.1, 4.4+/-0.2, 4.7+/-0.2 and 5.1+/-0.2; p=0.002). Ado A1 mRNA levels were highest in 12 and 21-month-old animals in both ventricles (LV: p<0.001; RV: p=0.001). By contrast, Ado A2A gene expression was lower in the aged LV (p<0.001), but higher in the aged RV (p<0.001). These modifications of Ado receptor gene expression and especially the increase in A1 receptor mRNA may partially explain the stronger antiadrenergic effects of Ado in the senescent heart.

+874(T-->A) single nucleotide gene polymorphism does not represent a risk factor for Alzheimer's disease.

In the recent years, several cytokines have been associated with Alzheimer's disease (AD) development and progression and many studies have correlated this risk with polymorphisms in the genes encoding these molecules. Also the type 1 cytokine interferon (IFN)-gamma belongs to a cytokine class that affects the immune function; in fact it plays a major role in defence against viruses and intracellular pathogens but also in the induction of the immune-mediated inflammatory response. The aim of this study was to evaluate the role of IFN-gamma in AD by studying the association of +874T-->A IFN-gamma gene polymorphism with AD. We included in this study 115 AD patients (70 women, 45 men, mean age 80) and 90 sex and age-matched healthy controls (HC, 51 women, 39 men, mean age 82) from northern Italy. Genomic DNA was extracted with the salting-out method from whole blood of all subjects; the genotyping at IFN-gamma loci was assessed with ARMS-PCR. The data obtained from the +874T-->A IFN-gamma gene polymorphism analysis of AD patients and HC lack of any statistically significant differences also when stratified according to gender. In conclusion these results confirm the previous shown lack of association between +874T-->A IFN-gamma gene polymorphism and the risk of AD. However, other polymorphisms have been demonstrated to influence IFN-gamma transcription and since natural killer cells of AD patients show higher production of the cytokine, further analysis will be necessary to clarify the role of this gene in the pathogenesis of the disease.

PIN-1 promoter polymorphisms in mild cognitive impairment and susceptibility to Alzheimer's disease: a preliminary report.

BACKGROUND AND AIMS: Peptydil prolyl cis-trans isomerase (PIN-1), which specifically regulates the conformational changes following phosphorylation of several proteins, targets the inactive hyper-phosphorylated tau on the Thr231-Pro motif and directly restores its biological function. Interestingly, PIN-1 is oxidatively inhibited not only in Alzheimer's disease brain but also in the hippocampi of mild cognitive impairment (MCI) subjects. The PIN-1 gene is characterized by two single nucleotide polymorphisms (SNPs) in the promoter region which are associated with the risk of Alzheimer's disease. The aim of this study was to analyse the genotype and allele distributions of these PIN-1 SNPs in MCI subjects diagnosed respectively as amnestic MCI (a-MCI) and multiple impaired cognitive domains (mcd-MCI) on the basis of cognitive features. METHODS: -667 T/C and -842 C/G SNPs were genotyped by polymerase chain reaction (PCR) amplification and direct sequencing in 43 MCI subjects, with the intention of comparing -667 and -842 SNP frequencies with those previously described in 111 Alzheimer's disease patients (AD) and 73 healthy controls (HC). RESULTS: The allele frequencies of the -842 C/G SNP in a-MCI subjects are similar to those of AD subjects, while those of mcd-MCI are comparable to HC (G allele 83% in both a-MCI and AD; 95% and 94% in mcd-MCI and HC, respectively). A similar trend is also observed in -842 C/G genotypes. CONCLUSIONS: Since a-MCI is thought to be the preclinical form of AD, the similar genotype distribution of -842 SNP in AD and a-MCI, but not in mcd-MCI, suggests that it is potentially involved in the conversion of a-MCI to AD. In conclusion, these findings support the theory that polymorphisms of the PIN-1 gene can affect neurodegeneration and its clinical progression.

Eplerenone, a selective aldosterone blocker, improves diastolic function in aged rats with small-to-moderate myocardial infarction.

BACKGROUND: The incidence of cardiovascular diseases increases rapidly with age, and the elderly suffer higher morbidity and mortality. Aldosterone blockers have shown benefits in patients with left ventricular (LV) dysfunction and heart failure after myocardial infarction (MI). However, aldosterone blockade efficacy has not been explored in aged animals with MI. Methods and results Small-to-moderate MI was induced by coronary artery ligation in 16-month old rats, divided into 3 groups: sham-operated (control, n = 9), MI (n = 9), and MI fed a diet containing eplerenone (120 mg/kg/day, MI+Eplerenone, n = 9) given 18 days postsurgery and up to sacrifice 3 months later. At sacrifice, untreated MI rats did not show overt systolic dysfunction but they had (1) echocardiographic evidences of impaired relaxation (increase of E wave deceleration time and of isovolumic relaxation time, decrease of peak E wave velocity), (2) hemodynamically impaired LV relaxation (LV -dP/dt from 7413 +/- 720 to 4956 +/- 475 mm Hg/s, P < .05), and (3) significant increase of collagen content in LV interstitium (from 4.27 +/- 0.23 to 5.34 +/- 0.24%, P < .01) and in aorta (from 19 +/- 1 to 24 +/- 2%, P < .05). Eplerenone normalized echocardiographic and hemodynamic evidences of diastolic dysfunction, as well as myocardial interstitial collagen and aortic fibrosis (all parameters statistically different from untreated MI). CONCLUSION: In aged rats with small to moderate MI, eplerenone normalized diastolic relaxation, possibly through a reduction of interstitial fibrosis.