Association of psychological distress and religious coping tendencies in parents of children recently diagnosed with cancer: A cross-sectional study.

PURPOSE: Parents of children with cancer exhibit high levels of psychological distress. Parents of children with serious illness report religion and spirituality are important coping resources. We sought to describe characteristics of religion, religious coping, social support, and resiliency in parents of children newly diagnosed with cancer and examine associations between psychological distress and self-reported religious coping, religiosity, resiliency, and social support. PATIENTS AND METHODS: Cross-sectional observational study of 100 parents of 81 unique children recently diagnosed with cancer. Parents provided demographic information and completed measures of psychological distress, importance of religion, religious coping, resiliency, and social support. Patients' type of tumor and intensity of treatment were collected by medical record abstraction. RESULTS: Compared to nationally reported data for adults, parents of children with cancer reported high scores for psychological distress but similar levels of religiosity, religious coping, and resiliency. Negative religious coping (feelings of negativity related to the divine) was associated with higher levels of psychological distress. This effect was most prominent in parents who reported the highest levels of religiosity. Positive religious coping, religiosity, and social support were not associated with levels of psychological distress. DISCUSSION: Findings confirm high levels of distress for parents of children with cancer. Negative religious coping was associated with higher levels of psychological distress but positive religious coping, religiosity, and other coping factors were not found to be significantly associated with distress. Further assessment of negative religious coping to inform interventions to promote resiliency is warranted as they may impact parental decision-making and care.

Angiotensin-III is Increased in Alzheimer's Disease in Association with Amyloid-ß and Tau Pathology.

Hyperactivity of the renin-angiotensin system (RAS) is associated with the pathogenesis of Alzheimer's disease (AD) believed to be mediated by angiotensin-II (Ang-II) activation of the angiotensin type 1 receptor (AT1R). We previously showed that angiotensin-converting enzyme-1 (ACE-1) activity, the rate-limiting enzyme in the production of Ang-II, is increased in human postmortem brain tissue in AD. Angiotensin-III (Ang-III) activates the AT1R and angiotensin type-2 receptor (AT2R), but its potential role in the pathophysiology of AD remains unexplored. We measured Ang-II and Ang-III levels by ELISA, and the levels and activities of aminopeptidase-A (AP-A) and aminopeptidase-N (AP-N) (responsible for the production and metabolism of Ang-III, respectively) in human postmortem brain tissue in the mid-frontal cortex (Brodmann area 9) in a cohort of AD (n = 90) and age-matched non-demented controls (n = 59), for which we had previous measurements of ACE-1 activity, Aß level, and tau pathology (also in the mid-frontal cortex). We found that both Ang-II and Ang-III levels were significantly higher in AD compared to age-matched controls and that Ang-III, rather than Ang-II, was strongly associated with Aß load and tau load. Levels of AP-A were significantly reduced in AD but AP-A enzyme activity was unchanged whereas AP-N activity was reduced in AD but AP-N protein level was unchanged. Together, these data indicate that the APA/Ang-III/APN/Ang-IV/AT4R pathway is dysregulated and that elevated Ang-III could contribute to the pathogenesis of AD.

Aß degradation or cerebral perfusion? Divergent effects of multifunctional enzymes.

There is increasing evidence that deficient clearance of ß-amyloid (Aß) contributes to its accumulation in late-onset Alzheimer disease (AD). Several Aß-degrading enzymes, including neprilysin (NEP), endothelin-converting enzyme (ECE), and angiotensin-converting enzyme (ACE) reduce Aß levels and protect against cognitive impairment in mouse models of AD. In post-mortem human brain tissue we have found that the activity of these Aß-degrading enzymes rise with age and increases still further in AD, perhaps as a physiological response that helps to minimize the build-up of Aß. ECE-1/-2 and ACE are also rate-limiting enzymes in the production of endothelin-1 (ET-1) and angiotensin II (Ang II), two potent vasoconstrictors, increases in the levels of which are likely to contribute to reduced blood flow in AD. This review considers the possible interdependence between Aß-degrading enzymes, ischemia and Aß in AD: ischemia has been shown to increase Aß production both in vitro and in vivo, whereas increased Aß probably enhances ischemia by vasoconstriction, mediated at least in part by increased ECE and ACE activity. In contrast, NEP activity may help to maintain cerebral perfusion, by reducing the accumulation of Aß in cerebral blood vessels and lessening its toxicity to vascular smooth muscle cells. In assessing the role of Aß-degrading proteases in the pathogenesis of AD and, particularly, their potential as therapeutic agents, it is important to bear in mind the multifunctional nature of these enzymes and to consider their effects on other substrates and pathways.

Angiotensin II-inhibition: effect on Alzheimer's pathology in the aged triple transgenic mouse.

Reducing excessive accumulation of amyloid-ß (Aß) in Alzheimer's disease (AD) is a key objective of most AD therapies, and inhibition of angiotensin-converting enzyme (ACE) may delay onset or progression of AD. The effects of an ACE-inhibitor (ACE-I) and an angiotensin II receptor blocker (ARB) on Aß and tau pathology in a triple transgenic (3xTGAD) mouse model of AD were investigated. 9-10month 3xTGAD mice were treated with ARB, ACE-I or vehicle for 6 months. Mean arterial blood pressure (MABP) was measured periodically and mice were assessed behaviourally. Aß, phospho-tau, amyloid precursor protein (APP) and ACE activity were analysed. MABP was significantly reduced at 2 weeks and 3 months in the ACE-I group and at 3 months in the ARB group, compared to vehicle. Neither drug altered performance of 3xTGAD mice in Morris Water Maze or T-maze, nor were Aß, tau immunolabelling or APP levels altered. ACE-I significantly reduced ACE activity in kidney. Prolonged treatment with ACE-I or ARB does not affect Aß or phospho-tau accumulation in brains of aged 3xTGAD mice.

Clusterin mRNA and protein in Alzheimer's disease.

Clusterin, a multifunctional lipoprotein is expressed in a number of tissues but expression is particularly high in the brain, where it binds to amyloid-ß (Aß), possibly facilitating Aß transport into the bloodstream. Its concentration in peripheral blood was identified as a potential biomarker for Alzheimer's disease (AD) and predicted retention of (11)C-Pittsburgh Compound B in the temporal lobe. Single-nucleotide polymorphisms in the clusterin gene, CLU, are associated with the risk of developing AD. We measured clusterin mRNA levels in control and AD brains and investigated the relationship of the clusterin protein to soluble, insoluble, and plaque-associated Aß. Clusterin mRNA levels were unchanged when normalized to GAPDH but modestly increased in the frontal and temporal cortex in AD in relation to NSE and MAP-2. Levels of NSE and MAP-2 mRNA were reduced in the AD frontal cortex. Clusterin protein concentration was unchanged and did not correlate with the amount of Aß present. In the frontal cortex, clusterin concentration was higher in APOE ε4-negative brains but no effect of APOE was detected in the temporal cortex or thalamus. Overall clusterin mRNA and protein levels are unaltered in the neocortex in AD and clusterin concentration does not reflect Aß content. The increase in clusterin noted in peripheral blood in AD may reflect increased passage of this chaperone protein across the blood-brain barrier but further work is needed to determine how CLU variants influence the development of AD.

Angiotensin II-inhibiting drugs have no effect on intraneuronal Aß or oligomeric Aß levels in a triple transgenic mouse model of Alzheimer's disease.

BACKGROUND: Reducing the excessive accumulation of amyloid ß-protein (Aß) in Alzheimer's disease (AD) is a key objective of most AD therapies. Several studies suggest that pharmacological inhibition of angiotensin-converting enzyme (ACE) or its by-product angiotensin II may delay onset or progression of dementia and it has been suggested that this occurs via regulation of Aß. Intraneuronal oligomeric accumulation of Aß is postulated to be one of the earliest pathological events. Thus this study investigated the effect of an ACE-inhibitor, captopril, and two angiotensin II receptor blockers (ARBs), eprosartan and valsartan, on intraneuronal Aß pathology and oligomeric Aß levels in a triple transgenic (3xTGAD) mouse model of AD. METHODS: Male, adult (3-4 month old) 3xTgAD mice (n=39) were randomly assigned to 4 treatment groups: valsartan (0.17g/l), eprosartan (0.8g/l), captopril (5g/l) or normal drinking water and the drugs given ad libitum for 2 months. Mean arterial blood pressure (MABP) was measured at baseline, at 2 weeks and at 2 months when the mice were sacrificed and the brains hemisected for analysis. One hemisphere was processed for Aß and amyloid precursor protein (APP) immunohistochemistry and the other for biochemical measurement of oligomeric Aß and APP. ACE activity was measured in the brain and kidney. RESULTS: MABP was significantly reduced at 2 weeks and 2 months in the ACE-I group (p=0.0006) but was unaltered in the ARB groups compared to vehicle. Neither ACE-I nor ARB treatment altered Aß and APP immunolabelling or the level of Aß or APP in brain tissue homogenates. Similarly neither ACE-I nor ARB treatment altered ACE activity in either brain or kidney compared to control tissue. CONCLUSIONS: ACE-I or ARB administration over 2 months did not affect APP levels or either intraneuronal Aß or oligomeric Aß levels in 3xTGAD mice. While ARBs did not alter MABP, captopril did mediate reductions in MABP in the 3xTGAD mice which appeared to be independent of ACE activity. Further studies are needed to examine the effects of these drugs over a longer term and in older mice (i.e. when AD-like changes are more pronounced).

Abeta-degrading enzymes in Alzheimer's disease.

In Alzheimer's disease (AD) Abeta accumulates because of imbalance between the production of Abeta and its removal from the brain. There is increasing evidence that in most sporadic forms of AD, the accumulation of Abeta is partly, if not in some cases solely, because of defects in its removal--mediated through a combination of diffusion along perivascular extracellular matrix, transport across vessel walls into the blood stream and enzymatic degradation. Multiple enzymes within the central nervous system (CNS) are capable of degrading Abeta. Most are produced by neurons or glia, but some are expressed in the cerebral vasculature, where reduced Abeta-degrading activity may contribute to the development of cerebral amyloid angiopathy (CAA). Neprilysin and insulin-degrading enzyme (IDE), which have been most extensively studied, are expressed both neuronally and within the vasculature. The levels of both of these enzymes are reduced in AD although the correlation with enzyme activity is still not entirely clear. Other enzymes shown capable of degrading Abetain vitro or in animal studies include plasmin; endothelin-converting enzymes ECE-1 and -2; matrix metalloproteinases MMP-2, -3 and -9; and angiotensin-converting enzyme (ACE). The levels of plasmin and plasminogen activators (uPA and tPA) and ECE-2 are reported to be reduced in AD. Reductions in neprilysin, IDE and plasmin in AD have been associated with possession of APOEepsilon4. We found no change in the level or activity of MMP-2, -3 or -9 in AD. The level and activity of ACE are increased, the level being directly related to Abeta plaque load. Up-regulation of some Abeta-degrading enzymes may initially compensate for declining activity of others, but as age, genetic factors and diseases such as hypertension and diabetes diminish the effectiveness of other Abeta-clearance pathways, reductions in the activity of particular Abeta-degrading enzymes may become critical, leading to the development of AD and CAA.