Reduced expression level of the cyclic adenosine monophosphate response element-binding protein contributes to lung aging.

Lung aging is associated with morphological and physiological changes in which alterations in transcription factors, including the cyclic adenosine monophosphate response element-binding protein (CREB), could play a role. We studied CREB in lung tissue from mice at different ages and in response to known age-related factors (e.g., cellular senescence and matrix modifications with advanced glycation end-products [AGEs]). Our study shows that protein but not mRNA levels of CREB are reduced in the lungs of old mice. CREB reduction was also observed in senescent human lung fibroblasts (WI-38, LuFi) and human lung epithelial cells (A549) cultured on AGE-modified collagen matrix. Reduction of CREB protein is partially based on pre- and posttranslational modifications as exhibited by an increase in the CREB-regulating microRNA 34b and CREB ubiquitination. Permanent down-regulation of CREB in lung cells impaired cell proliferation and viability and increased the number of cells with senescence-associated ß-galactosidase activity. CREB down-regulation was accompanied by the reduced expression of 165 genes in WI-38 fibroblasts and A549 epithelial cells, of which 15 genes showed a reduced expression in lung tissues of old mice. The CREB-dependent reduction in RAB27A coding for the Ras-related protein Rab27A and IGFBP3 coding for the insulin-like growth factor-binding protein 3 has been confirmed for aged lung tissue, senescent fibroblasts, and lung epithelial cells on AGE-modified collagen. Our data demonstrate that the reduced protein expression of CREB might play a significant role in lung aging by modifying the transcription of RAB27A, IGFBP3, and other target genes.

Microarray-based gene expression profiling suggests adaptation of lung epithelial cells subjected to chronic cyclic strain.

BACKGROUND/AIMS: Mechanical strain of the lung tissue is a physiological process that affects the behavior of lung cells. Since recent evidence also suggests alterations in the expression of certain genes as a consequence of mechanotransduction, our study aimed at the analysis of the gene expression profile in lung epithelial cells subjected to chronic cyclic strain. METHODS: Various human lung epithelial cell lines (A549 as principal adherent cell line and four others) were subjected to cyclic strain (16 % surface distension, 12 min(-1)) in a Strain Cell Culture Device for 24 h. In comparison to static controls, expression analyses were performed by gene microarray and qPCR. RESULTS: Microarray analysis revealed many differences in the gene expression but at moderate levels. Altogether 25 genes were moderately down-regulated (0.86-fold ± 0.06) and 26 genes were up-regulated (1.18-fold ± 0.10) in A549 and the others. Strain-regulated genes often code for transcription factors, such as E2F4 and SRF. qPCR analyses confirmed the up-regulation of both transcription factors and further genes, such as PLAU (urokinase-type plasminogen activator) and S100A4 (S100 protein A4). Moreover, we showed the down-regulations of AGR2 (anterior gradient 2) and LCN2 (lipocalin 2). CONCLUSIONS: We identified many genes of which the expression was moderately altered in lung epithelial cells subjected to chronic cyclic strain. Although many moderate changes in the gene expression profile might affect cellular behavior, it also suggests an effective adaptation of cells to mechanical forces in long-term conditions.

Glycation of extracellular matrix proteins impairs migration of immune cells.

The immune response during aging and diabetes is disturbed and may be due to the altered migration of immune cells in an aged tissue. Our study should prove the hypothesis that age and diabetes-related advanced glycation end products (AGEs) have an impact on the migration and adhesion of human T-cells. To achieve our purpose, we used in vitro AGE-modified proteins (soluble albumin and fibronectin [FN]), as well as human collagen obtained from bypass graft. A Boyden chamber was used to study cell migration. Migrated Jurkat T-cells were analyzed by flow cytometry and cell adhesion by crystal violet staining. Actin polymerization was determined by phalloidin-Alexa-fluor 488-labeled antibody and fluorescence microscopy. We found that significantly fewer cells (50%, p = 0.003) migrated through methylglyoxal modified FN. The attachment to FN in the presence of AGE-bovine serum albumin (BSA) was also reduced (p < 0.05). In ex vivo experiments, isolated collagen from human vein graft material negatively affected the migration of the cells depending on the grade of AGE modification of the collagen. Collagen with a low AGE level reduced the cell migration by 30%, and collagen with a high AGE level by 60%. Interaction of the cells with an AGE-modified matrix, but not with soluble AGEs like BSA-AGE per se, was responsible for a disturbed migration. The reduced migration was accompanied by an impaired actin polymerization. We conclude that AGEs-modified matrix protein inhibits cell migration and adhesion of Jurkat T-cells.

Cell culture condition-dependent impact of AGE-rich food extracts on kinase activation and cell survival on human fibroblasts.

Advanced glycation end products (AGEs) are stable end products of the Maillard reaction. Effects of food extracts are often initially analysed in cellular test systems and it is not clear how different cell culture conditions might influence the results. Therefore, we compared the effects of two models for AGE-rich food, bread crust and coffee extract (CE) on WI-38 human lung fibroblasts under different cell culture conditions (sub-confluent versus confluent cells, with and without serum). WI-38 cells responded to coffee and bread crust extract (BCE) with a rapid phosphorylation of PKB (AKT), p42/44 MAPK (ERK 1/2) and p38 MAPK, strongly depending on culture conditions. BCE resulted in increased cell numbers, whereas CE appeared to be cytotoxic. When cell numbers under all culture conditions and treatments were correlated with kinase phosphorylation, the relation between phospho-p38 MAPK and phospho-AKT represented a good, cell culture condition-independent predictor of cell survival.

The receptor for advanced glycation end-products supports lung tissue biomechanics.

The receptor for advanced glycation end-products (RAGE) and its soluble forms are predominantly expressed in lung but its physiological importance in this organ is not yet fully understood. Since RAGE acts as a cell adhesion molecule, we postulated its physiological importance in the respiratory mechanics. Respiratory function in a buffer-perfused isolated lung system and biochemical parameters of the lung were studied in young, adult, and old RAGE knockout (RAGE-KO) mice and wild-type (WT) mice. Lungs from RAGE-KO mice showed a significant increase in the dynamic lung compliance and a decrease in the maximal expiratory air flow independent of age-related changes. We also determined lower mRNA and protein levels of elastin in lung tissue of RAGE-KO mice. RAGE deficiency did not influence the collagen protein level, lung capillary permeability, and inflammatory parameters (TNF-α, high-mobility group box protein 1) in lung. Overexpressing RAGE as well as soluble RAGE in lung fibroblasts or cocultured lung epithelial cells increased the mRNA expression of elastin. Moreover, immunoprecipitation studies indicated a trans interaction of RAGE in lung epithelial cells. Our findings suggest the physiological importance of RAGE and its soluble forms in supporting the respiratory mechanics in which RAGE trans interactions and the influence on elastin expression might play an important role.

Age-dependent effects of high fat-diet on murine left ventricles: role of palmitate.

Obesity-associated heart disease results in myocardial lipid accumulation leading to lipotoxicity. However, recent studies are suggestive of protective effects of high-fat diets (HFD). To determine whether age results in differential changes in diet-induced obesity, we fed young and old (3 and 18 months) male C57Bl/6 mice control diet, low-fat diet (both 10 kcal% fat) or HFD (45 kcal% fat) for 16 weeks, after which we analyzed LV function, mitochondrial changes, and potential modifiers of myocardial structure. HFD or age did not change LV systolic function, although a mildly increased BNP was observed in all old mice. This was associated with increased myocardial collagen, triglyceride, diacylglycerol, and ceramide content as well as higher caspase 3 activation in old mice with highest levels in old HFD mice. Pyruvate-dependent respiration and mitochondrial biogenesis were reduced in all old mice and in young HFD mice. Activation of AMPK, a strong inducer of mitochondrial biogenesis, was reduced in both HFD groups and in old control or LFD mice. Cardiomyocytes from old rats demonstrated significantly reduced AMPK activation, impaired mitochondrial biogenesis, higher ceramide content, and reduced viability after palmitate (C16:0) in vitro, while no major deleterious effects were observed in young cardiomyocytes. Aged but not young cardiomyocytes were unable to respond to higher palmitate with increased fatty acid oxidation. Thus, HFD results in cardiac structural alterations and accumulation of lipid intermediates predominantly in old mice, possibly due to the inability of old cardiomyocytes to adapt to high-fatty acid load.

Embolic events caused by aortic thrombi: an underestimated entity?

Stroke and other thromboembolic events are mainly caused by emboli from heart, aorta and other arteries. In this paper we describe a group of 5 middle-aged patients suffering from emboli caused by large thrombi in the aorta. Since the development of giant thrombi under high flow conditions in the aorta is a pathophysiological process which is not well understood, a model of flow distribution by numerically simulating the Navier-Stokes equation for an incompressible fluid was generated. This model simulated how such thrombi may develop in the aorta. We hypothesize that large thrombi issuing from the aortic vessel wall represent a underestimated entity in middleaged persons and are probably overlooked as the cause of stroke or other embolic events in some cases.

Living Longer or Better-Patient's Choice in Cardiac Surgery Is Gender-Dependent-A Multicenter Study.

In view of the increasing age of cardiac surgery patients, questions arise about the expected postoperative quality of life and the hoped-for prolonged life expectancy. Little is known so far about how these, respectively, are weighted by the patients concerned. This study aims to obtain information on the patients' preferences. Between 2015 and 2017, data were analyzed from 1349 consecutive patients undergoing cardiac surgery at seven heart centers in Germany. Baseline data regarding the patient's situation as well as a questionnaire regarding quality of life versus lifespan were taken preoperatively. Patients were divided by age into four groups: below 60, 60-70, 70-80, and above 80 years. As a result, when asked to decide between quality of life and length of life, about 60% of the male patients opted for quality of life, independent of their age. On the other hand, female patients' preference for quality of life increased significantly with age, from 51% in the group below sixty to 76% in the group above eighty years. This finding suggests that female patients adapt their preferences with age, whereas male patients do not. This should impact further the treatment decisions of elderly patients in cardiac surgery within a shared decision-making process.

Intra-aortic balloon counterpulsation in the treatment of infarction-related cardiogenic shock--review of the current evidence.

The European ST-elevated myocardial infarction (STEMI) guideline suggested the intra-aortic balloon pump (IABP) with a recommendation level I and a level of evidence C as an effective measure in combination with balloon angioplasty in patients with cardiogenic shock (CS), stent implantation, and inotropic and vasopressor support. Similarly, upon mechanical complication due to myocardial infarction (MI), the guideline suggests that in patients with a ventricular septal defect or in most patients with acute mitral regurgitation, preoperative IABP implantation is indicated for circulatory support. The American College of Cardiology/American Heart Association STEMI guideline recommends the use of the IABP with a recommendation level I and a level of evidence B if CS does not respond rapidly to pharmacological treatment. The guideline notes that the IABP is a stabilizing measure for angiography and early revascularization. Even in MI complications, the use of preoperative IABP is recommended before surgery. Within this overview, we summarize the current evidence on IABP use in patients with CS complicated by MI. From our Cochrane data analysis, we conclude that in CS due to acute MI (AMI) treated with adjuvant systemic fibrinolysis, the IABP should be implanted. In patients with CS following AMI, treated with primary percutaneous coronary intervention (PCI), the IABP can be implanted, although data are not distinctive (i.e., indicating positive and negative effects). In the future, randomized controlled trials are needed to determine the use of IABP in CS patients treated with PCI. When patients with CS are transferred to a PCI center with or without thrombolysis, patients should receive mechanical support with an IABP. To treat mechanical MI complications-in particular ventricular septal defect-patients should be treated with an IABP to stabilize their hemodynamic situation prior to cardiac surgery. Similar recommendations are given in the German Austrian guidelines on treatment of infarction-related CS patients (http://www.awmf.org/leitlinien/detail/ll/019-013.html).

Statins potently reduce the cytokine-mediated IL-6 release in SMC/MNC cocultures.

Inflammatory pathways are involved in the development of atherosclerosis. Interaction of vessel wall cells and invading monocytes by cytokines may trigger local inflammatory processes. 3-Hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) are standard medications used in cardiovascular diseases. They are thought to have anti-inflammatory capacities, in addition to their lipid-lowering effects. We investigated the anti-inflammatory effect of statins in the cytokine-mediated-interaction-model of human vascular smooth muscle cells (SMC) and human mononuclear cells (MNC). In this atherosclerosis-related inflammatory model LPS (lipopolysaccharide, endotoxin), as well as high mobility group box 1 stimulation resulted in synergistic (i.e. over-additive) IL-6 (interleukin-6) production as measured in ELISA. Recombinant IL-1, tumour necrosis factor-α and IL-6 mediated the synergistic IL-6 production. The standard anti-inflammatory drugs aspirin and indomethacin (Indo) reduced the synergistic IL-6 production by 60%. Simvastatin, atorvastatin, fluvastatin or pravastatin reduced the IL-6 production by 53%, 50%, 64% and 60%, respectively. The inhibition by the statins was dose dependent. Combination of statins with aspirin and/or Indo resulted in complete inhibition of the synergistic IL-6 production. The same inhibitors blocked STAT3 phosphorylation, providing evidence for an autocrine role of IL-6 in the synergism. MNC from volunteers after 5 day aspirin or simvastatin administration showed no decreased IL-6 production, probably due to drug removal during MNC isolation. Taken together, the data show that anti-inflammatory functions (here shown for statins) can be sensitively and reproducibly determined in this novel SMC/MNC coculture model. These data implicate that statins have the capacity to affect atherosclerosis by regulating cytokine-mediated innate inflammatory pathways in the vessel wall.

Prognostic potential and tumor growth-inhibiting effect of plasma advanced glycation end products in non-small cell lung carcinoma.

The plasma fluorescence related to the standard fluorescence of advanced glycation end products (AGEs) is a simple measurable blood parameter for distinct diseases but its importance in human cancer, including non-small cell lung carcinoma (NSCLC), is unknown. Plasma samples of 70 NSCLC patients who underwent resection surgery of the tumor were analyzed for the distinct AGE-related fluorescence at 370 nm excitation/440 nm emission. In a retrospective study, we tested the prognostic relevance of this AGE-related plasma fluorescence. The effect of circulating AGEs on the NSCLC growth was studied experimentally in vitro and in vivo. NSCLC patients with high (> median) AGE-related plasma fluorescence were characterized by a later reoccurrence of the tumor after curative surgery and a higher survival rate compared with patients with low plasma fluorescence (25% versus 47% 5-y survival, P = 0.011). Treating NSCLC cell spheroids with patients' plasma showed an inverse correlation between the growth of spheroids in vitro and the individual AGE-related fluorescence of each plasma sample. To confirm the impact of circulating AGEs on the NSCLC progression, we studied the NSCLC growth in mice whose circulating AGE level was elevated by AGE-rich diet. In vivo tumorigenicity assays demonstrated that mice with higher levels of circulating AGEs developed smaller tumors than mice with normal AGE levels. The AGE-related plasma fluorescence has prognostic relevance for NSCLC patients in whom the tumor growth-inhibiting effect of circulating AGEs might play a critical role.

Effect of diabetes mellitus on the outcome of patients with resected non-small cell lung carcinoma.

BACKGROUND: Both diabetes mellitus (DM) and non-small cell lung carcinoma (NSCLC) are age-related diseases and therefore occur simultaneously. DM and, in particular, diabetic nephropathy are associated with an increased modification of the extracellular tissue matrix with advanced glycation end-products (AGEs). OBJECTIVE: As AGE-modified matrix impairs the invasive migration of lung carcinoma cells, our study aimed at the effect of DM on the NSCLC-related outcome. METHODS: In a retrospective clinical study, we analyzed the time-dependent survival of NSCLC patients with DM compared to patients without DM, who had been treated for cancer by resection surgery. The age-matched study population (51-80 years) included 55 DM patients and 111 non-DM patients. RESULTS: Comparative analyses between DM and non-DM patients did not find significant differences for NSCLC histology, tumor stage and stay in the hospital. Analyses of the mid-term (20-month) survival showed that the DM group had a significantly higher proportion of NSCLC patients being alive 20 months after tumor resection than the non-DM group (76 vs. 59%, p = 0.048). The DM-related increase in the mid-term survival rate was particularly observed for patients without lymph node metastasis (88%) and those patients also suffering from nephropathy (90%). In contrast to the mid-term survival, DM had no effect on the long-term (60-month) survival of NSCLC patients (35 vs. 32% in the non-DM group). CONCLUSION: Our study indicates that DM-associated changes mediate beneficial effects in terms of NSCLC progression, in which AGE modifications might play a critical role.

Age-associated changes of extracellular matrix collagen impair lung cancer cell migration.

Although advanced age is linked with an increased incidence of lung carcinomas, elderly patients develop fewer metastatic tumors than their younger counterparts. Since extracellular matrix controls carcinogenesis, we studied the effect of aged fibrillar collagen (rat tail) on the invasiveness of lung carcinoma cells (H322, H358). Two- and three-dimensional invasion assays revealed a reduced migration of lung cancer cells through a matrix of collagen from old (24 mo) compared with young (2 mo) or adult (12 mo) rats. This was most strongly observed for H322 cells, which had a better migration behavior than H358 cells. Since old collagen was increasingly modified by advanced glycation end products (AGEs; fluorescing AGEs, nonfluorescing carboxymethyllysine), we generated different AGE-collagens by treating collagen with ribose or alpha-dicarbonyls. Similarly to old collagen, AGE-collagen reduced the invasive migration of H322 cells. Subsequent analyses demonstrated that old and AGE-collagens impair distinct mechanisms contributing to cell migration, i.e., efficient cell adhesion and proteolytic degradation of collagen by membrane-type matrix metalloproteinase (MT-MMP; MT-MMP3 in H322 cells). Our data indicate that age-related alterations of the extracellular matrix contribute to a less invasive behavior of lung carcinoma cells, in which AGE modifications of aged collagen seem to play an important role.

Inotropic effects of ivabradine in the mammalian heart.

Ivabradine represents a novel heart-rate-lowering agent that acts on the sino-atrial node supposedly by selectively inhibiting the 'funny' current (I(f) current). In clinical studies, it was reported that ivabradine effectively reduced resting heart rate and was well tolerated. The aim of this study was to evaluate potential effects of ivabradine on cardiac contractility. Contractile effects of ivabradine were studied in isolated electrically driven atrial preparations from patients undergoing cardiac bypass surgery and for comparison in isolated spontaneously beating right atria and electrically driven left atria from mice. In human trabeculae, a concentration-dependent negative inotropic effect was noted in 7 from 10 patients. However, in 3 patients from 10, a pronounced positive inotropic effect of ivabradine was noted. As expected, in spontaneously beating mouse right atria ivabradine exerted a concentration-dependent negative chronotropic effect. Unexpectedly, contractile effects in mouse and man seem to disagree. In mouse left atria, ivabradine and cilobradine, another hyperpolarization-activated cyclic-nucleotide-gated blocker, always exerted a pronounced positive inotropic effect. These positive inotropic effects were converted to negative inotropic effects in the additional presence of the L-type Ca²+ channel blocker verapamil. The present study demonstrates that ivabradine at high concentrations can affect the force of contraction in atrial preparations from the human heart.

It's all in our skin-Skin autofluorescence-A promising outcome predictor in cardiac surgery: A single centre cohort study.

BACKGROUND: The optimum risk score determining perioperative mortality and morbidity in cardiac surgery remains debated. Advanced glycation end products (AGEs) derived from glycaemic and oxidative stress accumulate to a comparable amount in skin and the cardiovascular system leading to a decline in organ function. We aimed to study the association between AGE accumulation measured as skin autofluorescence (sAF) and the outcome of cardiac surgery patients. METHODS: Between April 2008 and November 2016, data from 758 consecutive patients undergoing coronary artery bypass grafting, aortic valve replacement or a combined procedure were analyzed. Skin autofluorescence was measured using an autofluorescence reader. Beside mortality, for the combined categorical morbidity outcome of each patient failure of the cardiac-, pulmonary-, renal- and cerebral system, as well as reoperation and wound healing disorders were counted. Patients without or with only one of the outcomes were assigned zero points whereas more than one outcome failure resulted in one point. Odds ratios (ORs) were estimated in multivariable logistic regression analysis with other preoperative parameters and the established cardiac surgery risk score systems EuroSCORE II and STS score. RESULTS: Skin autofluorescence as non-invasive marker of tissue glycation provided the best prognostic value in identifying patients with major morbidity risks after cardiac surgery (OR = 3.13; 95%CI 2.16-4.54). With respect to mortality prediction the STS score (OR = 1.24; 95%CI 1.03-1.5) was superior compared to the EuroSCORE II (OR = 1.17: 95%CI 0.96-1.43), but not superior when compared to sAF (OR = 6.04; 95%CI 2.44-14.95). CONCLUSION: This finding suggests that skin autofluorescence is a good biomarker candidate to assess the perioperative risk of patients in cardiac surgery. Since the EuroSCORE does not contain a morbidity component, in our view further sAF measurement is an option.

Advanced glycation end product accumulation in rho(0) cells without a functional respiratory chain.

Advanced glycation end products (AGEs) accumulate during ageing with reactive oxygen species from the mitochondrial respiratory chain discussed as a driving force. To determine the role of mitochondrial activity for AGE formation, a rho(0) derivative of the 143B.TK(-) osteosarcoma cell line lacking the respiratory chain, was analysed. These cells exhibit decreased superoxide formation but unchanged mitochondrial SOD expression as well as unchanged antioxidative free sulfhydryl (SH) levels. Whereas total protein content shows no differences in AGE levels, cell fractionation and Western blotting demonstrates some changes in the AGE pattern. Thus, the absence of functional respiration has only a negligible impact on AGE accumulation.

Simultaneous expression of Cathepsins B and K in pulmonary adenocarcinomas and squamous cell carcinomas predicts poor recurrence-free and overall survival.

PURPOSE: Patient survival after resection of non-small cell lung cancer (NSCLC) strongly correlated with the occurrence of distant metastasis. Cathepsins are members of the lysosomal cysteine proteases family and can support the metastatic process by degrading the extracellular matrix. The purpose of this study was to identify members of the Cathepsin family that correlate with recurrence-free and overall survival of NSCLC patients. PATIENTS AND METHODS: The expression of 13 Cathepsins was examined using DNA-microarray technology in tumor tissues of 89 surgically treated NSCLC patients. All NSCLC samples were classified according to median Cathepsin expression value into either a high or a low expression group. All Cathepsin expression groups were subjected to clinical prognostic analyses regarding survival and local as well as distant recurrences. RESULTS: Patients with high Cathepsin C tumor expression showed higher tumor recurrence rate compared to patients with low Cathepsin C expression (p = 0.02). The tumor expression of Cathepsins K and B significantly correlated with recurrence-free and overall survival as determined by multivariate analysis. A high expression of Cathepsin B or K was associated with a considerable reduction of recurrence-free as well as overall survival. NSCLC patients with a high expression of both Cathepsin B and K had a significantly (p = 0.001) poorer outcome (5-year survival rate: 13%) than patients with low expression of both genes (5-year survival rate: 75%). CONCLUSIONS: The combined expression level of Cathepsins B and K identifies high-risk NSCLC patients. A selection of gene expression panels is theoretically superior to established clinical and pathological criteria.

Age-Dependent Protein Expression of Serine/Threonine Phosphatases and Their Inhibitors in the Human Cardiac Atrium.

Heart failure and aging of the heart show many similarities regarding hemodynamic and biochemical parameters. There is evidence that heart failure in experimental animals and humans is accompanied and possibly exacerbated by increased activity of protein phosphatase (PP) 1 and/or 2A. Here, we wanted to study the age-dependent protein expression of major members of the protein phosphatase family in human hearts. Right atrial samples were obtained during bypass surgery. Patients (n=60) were suffering from chronic coronary artery disease (CCS 2-3; New York Heart Association (NYHA) stage 1-3). Age ranged from 48 to 84 years (median 69). All patients included in the study were given ß-adrenoceptor blockers. Other medications included angiotensin-converting enzyme (ACE) or angiotensin-receptor-1 (AT1) inhibitors, statins, nitrates, and acetylsalicylic acid (ASS). 100 µg of right atrial homogenates was used for western blotting. Antibodies against catalytic subunits (and their major regulatory proteins) of all presently known cardiac serine/threonine phosphatases were used for antigen detection. In detail, we studied the expression of the catalytic subunit of PP1 (PP1c); I1 PP1 and I2 PP1, proteins that can inhibit the activity of PP1c; the catalytic subunit of PP2A (PP2Ac); regulatory A-subunit of PP2A (PP2AA); regulatory B56α-subunit of PP2A (PP2AB); I1 PP2A and I2 PP2A, inhibitory subunits of PP2A; catalytic and regulatory subunits of calcineurin: PP2BA and PP2BB; PP2C; PP5; and PP6. All data were obtained within the linear range of the assay. There was a significant decline in PP2Ac and I2 PP2A expression in older patients, whereas all other parameters remained unchanged with age. It remains to be elucidated whether the decrease in the protein expression of I2 PP2A might elevate cardiac PP2A activity in a detrimental way or is overcome by a reduced protein expression and thus a reduced activity of PP2Ac.

Alterations of protein expression of phospholamban, ZASP and plakoglobin in human atria in subgroups of seniors.

The mature mammalian myocardium contains composite junctions (areae compositae) that comprise proteins of adherens junctions as well as desmosomes. Mutations or deficiency of many of these proteins are linked to heart failure and/or arrhythmogenic cardiomyopathy in patients. We firstly wanted to address the question whether the expression of these proteins shows an age-dependent alteration in the atrium of the human heart. Right atrial biopsies, obtained from patients undergoing routine bypass surgery for coronary heart disease were subjected to immunohistology and/or western blotting for the plaque proteins plakoglobin (γ-catenin) and plakophilin 2. Moreover, the Z-band protein cypher 1 (Cypher/ZASP) and calcium handling proteins of the sarcoplasmic reticulum (SR) like phospholamban, SERCA and calsequestrin were analyzed. We noted expression of plakoglobin, plakophilin 2 and Cypher/ZASP in these atrial preparations on western blotting and/or immunohistochemistry. There was an increase of Cypher/ZASP expression with age. The present data extend our knowledge on the expression of anchoring proteins and SR regulatory proteins in the atrium of the human heart and indicate an age-dependent variation in protein expression. It is tempting to speculate that increased expression of Cypher/ZASP may contribute to mechanical changes in the aging human myocardium.

Age-specific effects of short- and long-term caloric restriction on the expression of adiponectin and adiponectin receptors: influence of intensity of food restriction.

Hormonal signals from adipose tissue regulate energy homeostasis and may be involved in anti-aging effects of caloric restriction (CR). The adipokine adiponectin is abundantly expressed in adipose tissue and directly sensitizes the body to insulin. The purpose of the current study was to investigate age-dependent effects of different levels of CR (16%, 2 months or 40%, 6 months) on adiponectin and on its receptors AdipoR1 and AdipoR2 in the left ventricle (LV). In young and senescent rats, 2 months of moderate CR reduced serum leptin. The same diet was sufficient to enhance serum adiponectin, adiponectin expression (visceral fat) and left ventricular AdipoR1 expression in young but not in senescent rats. The higher degree of CR, however, resulted in a mild induction of adiponectin expression in adipose tissue and release into plasma together with increased LV AdipoR1 also in old rats, while these effects were more pronounced in young rats. These changes in adiponectin activation were associated with reduced LV triglyceride content, suggesting an adiponectin-mediated reduced ectopic lipid deposition in nonadipose tissues. Thus, aging is associated with a loss of adiponectin inducibility by moderate CR. This reduction can only partially be overcome by increasing the degree and duration of CR.