Age-Dependent Changes in Nrf2/Keap1 and Target Antioxidant Protein Expression Correlate to Lipoxidative Adducts, and Are Modulated by Dietary N-3 LCPUFA in the Hippocampus of Mice

The brain has a high metabolism rate that may generate reactive oxygen and nitrogen species. Consequently, nerve cells require highly efficient antioxidant defenses in order to prevent a condition of deleterious oxidative stress. This is particularly relevant in the hippocampus, a highly complex cerebral area involved in processing superior cognitive functions. Most current evidence points to hippocampal oxidative damage as a causal effect for neurodegenerative disorders, especially Alzheimer's disease. Nuclear factor erythroid-2-related factor 2/Kelch-like ECH-associated protein 1 (Nrf2/Keap1) is a master key for the transcriptional regulation of antioxidant and detoxifying systems. It is ubiquitously expressed in brain areas, mainly supporting glial cells. In the present study, we have analyzed the relationships between Nrf2 and Keap1 isoforms in hippocampal tissue in response to aging and dietary long-chain polyunsaturated fatty acids (LCPUFA) supplementation. The possible involvement of lipoxidative and nitrosative by-products in the dynamics of the Nrf2/Keap1 complex was examined though determination of protein adducts, namely malondialdehyde (MDA), 4-hydroxynonenal (HNE), and 3-nitro-tyrosine (NTyr) under basal conditions. The results were correlated to the expression of target proteins heme-oxygenase-1 (HO-1) and glutathione peroxidase 4 (GPx4), whose expressions are known to be regulated by Nrf2/Keap1 signaling activation. All variables in this study were obtained simultaneously from the same preparations, allowing multivariate approaches. The results demonstrate a complex modification of the protein expression patterns together with the formation of adducts in response to aging and diet supplementation. Both parameters exhibited a strong interaction. Noticeably, LCPUFA supplementation to aged animals restored the Nrf2/Keap1/target protein patterns to the status observed in young animals, therefore driving a "rejuvenation" of hippocampal antioxidant defense.

Molecular and biophysical features of hippocampal "lipid rafts aging" are modified by dietary n-3 long-chain polyunsaturated fatty acids

"Lipid raft aging" in nerve cells represents an early event in the development of aging-related neurodegenerative diseases, such as Alzheimer's disease. Lipid rafts are key elements in synaptic plasticity, and their modification with aging alters interactions and distribution of signaling molecules, such as glutamate receptors and ion channels involved in memory formation, eventually leading to cognitive decline. In the present study, we have analyzed, in vivo, the effects of dietary supplementation of n-3 LCPUFA on the lipid structure, membrane microviscosity, domain organization, and partitioning of ionotropic and metabotropic glutamate receptors in hippocampal lipid raffs in female mice. The results revealed several lipid signatures of "lipid rafts aging" in old mice fed control diets, consisting in depletion of n-3 LCPUFA, membrane unsaturation, along with increased levels of saturates, plasmalogens, and sterol esters, as well as altered lipid relevant indexes. These changes were paralleled by increased microviscosity and changes in the raft/non-raft (R/NR) distribution of AMPA-R and mGluR5. Administration of the n-3 LCPUFA diet caused the partial reversion of fatty acid alterations found in aged mice and returned membrane microviscosity to values found in young animals. Paralleling these findings, lipid rafts accumulated mGluR5, NMDA-R, and ASIC2, and increased their R/NR proportions, which collectively indicate changes in synaptic plasticity. Unexpectedly, this diet also modified the lipidome and dimension of lipid rafts, as well as the domain redistribution of glutamate receptors and acid-sensing ion channels involved in hippocampal synaptic plasticity, likely modulating functionality of lipid rafts in memory formation and reluctance to age-associated cognitive decline.

P372 PATIENTS WITH MINOR NON–DISABLING STROKE (MINDS): RESULTS OF A STRUCTURED CARDIOVASCULAR REHABILITATION PROGRAM

Background

Ischemic cerebral and cardiac events are the leading causes of mortality and morbidity in Minor non–Disabling Stroke (MiNDS) patients. Control of cardiovascular risk factors, including physical activity levels, is a key strategy in secondary prevention of MiNDS. However, there is a gap between recommendations and real achieved physical activity levels in these patients. Clinical benefits obtained with cardiovascular rehabilitation in cardiac ischemic patients could be obtained with similar programs also in patients with MiNDS, given the common pathophysiological substrate of these two diseases Purpose To evaluate safety, effectiveness and feasibility of a cardiovascular rehabilitation program based on structured physical exercise (SPE) in patients with MiNDS

Methods

39 MiNDS patients (26 males, mean age 66 years) underwent an accurate medical screening process, body composition evaluation, cardiopulmonary exercise test (CPET) and muscular strength assessment, before and after a 12–sessions in–hospital SPE program, and after 6– and 12–months follow–up during which they could continue their training schedule on their own Results After in–hospital rehabilitation program, a significant improvement in CPET parameters, body composition and muscular strength was observed. These modifications persisted in the 32 patients who continued 6– and 12– months follow–up training, while regressed in the 7 patients who stopped training

Conclusions - Results

of the present study show that a SPE–based cardiovascular rehabilitation program provides clinical benefit in patients with MiNDS

P368 PHYSICAL AND PSYCHOLOGICAL RECONDITIONING IN LONG COVID SYNDROME: RESULTS OF AN OUT–OF–HOSPITAL EXERCISED–BASED CARDIOVASCULAR REHABILITATION PROGRAM

Background

Long Covid Syndrome (LCS) is used to describe signs and symptoms that continue or develop after acute COVID–19 infection. Natural history and treatments of this syndrome are still poorly understood, even if evidence suggests the potential role of physical rehabilitation in improving symptoms in these subjects.

Aim

The aim of the present study was to evaluate safety, effectiveness and feasibility of a multidisciplinary, out–of–hospital, exercise–based cardiac rehabilitation (EBCR) program, of two months duration, in improving symptoms and physical and psychological parameters in patients with LCS Methods Thirty consecutive patients with LCS (18 males, mean age 58 years) underwent an accurate medical screening process including anthropometric and muscular strength evaluation, cardiopulmonary exercise test (CPET), quality of life (QoL) and psychological appraisal before and after an EBCR program.

Results

At baseline, all LCS patients were strongly symptomatic and showed severe impairments in physical performance, QoL and psychological parameters. No adverse effects and dropouts were observed during the exercise training sessions. After the EBCR program, COVID–19 residual symptoms significantly decreased and significant improvements in upper and lower limb muscular strength, CPET parameters, perceived physical and mental health, depression and anxiety were observed.

Conclusions

The present study confirms the severe physical and psychological impairment of patients with LCS and suggests that a multidisciplinary EBCR program could promote their physical and psychological recovery

Patients with Minor Non-Disabling Stroke (MiNDS): results of a structured cardiovascular rehabilitation program

Funding Acknowledgements

Type of funding sources: None.

Background

Ischemic cerebral and cardiac events are the leading causes of mortality and morbidity in Minor non-Disabling Stroke (MiNDS) patients. Control of cardiovascular risk factors, including physical activity levels, is a key strategy in secondary prevention of MiNDS. However, there is a gap between recommendations and real achieved physical activity levels in these patients. Clinical benefits obtained with cardiovascular rehabilitation in cardiac ischemic patients could be obtained with similar programs also in patients with MiNDS, given the common pathophysiological substrate of these two diseases.

Purpose

To evaluate safety, effectiveness and feasibility of a cardiovascular rehabilitation program based on structured physical exercise (SPE) in patients with MiNDS.

Methods

39 MiNDS patients (26 males, mean age 66 years) underwent an accurate medical screening process, body composition evaluation, cardiopulmonary exercise test (CPET) and muscular strength assessment, before and after a 12-sessions in-hospital SPE program, and after 6- and 12-months follow-up during which they could continue their training schedule on their own.

Results

After in-hospital rehabilitation program, a significant improvement in CPET parameters, body composition and muscular strength was observed. These modifications persisted in the 32 patients who continued 6- and 12- months follow-up training, while regressed in the 7 patients who stopped training.

Conclusions

Results of the present study show that a SPE-based cardiovascular rehabilitation program provides clinical benefit in patients with MiNDS.

Physical and psychological reconditioning in long covid syndrome patients: results of a structured physical exercise program

Funding Acknowledgements

Type of funding sources: None.

Background

Long Covid Syndrome (LCS) is used to describe signs and symptoms that continue or develop after acute COVID-19 infection. Natural history and treatments of this syndrome is still poorly understood. In literature there is currently a lack of data on the real effectiveness of a multidisciplinary rehabilitation program based on structured physical exercise (SPE) in these patients.

Purpose

To evaluate safety, effectiveness and feasibility of a structured individualized rehabilitation program in improving physical and psychological parameters in patients with LCS.

Methods

Twenty-eight patients with LCS (19 males, mean age 57 years) underwent an accurate medical screening process, body composition evaluation, cardiopulmonary exercise test (CPET), muscular strength assessment, quality of life (QoL), psychological assessment and counselling, before and after a 12-sessions SPE program.

Results

At baseline, all LCS patients showed severe impairments in physical performance, QoL and psychological parameters. No adverse effects and dropouts were observed during training session. After the rehabilitation program, significant improvement in CPET parameters, upper and lower limb muscular strength, perceived physical and mental health, body composition, depression and anxiety and Covid residual symptoms was observed.

Conclusions

The present study confirms severe impairment of patients with LCS and suggest that a multidisciplinary rehabilitation program based on SPE could promote their physical and psychological recovery.

Disarranged neuroplastin environment upon aging and chronic stress recovery in female Sprague Dawley rats

Chronic stress produces long-term metabolic changes throughout the superfamily of nuclear receptors, potentially causing various pathologies. Sex hormones modulate the stress response and generate a sex-specific age-dependent metabolic imprint, especially distinct in the reproductive senescence of females. We monitored chronic stress recovery in two age groups of female Sprague Dawley rats to determine whether stress and/or aging structurally changed the glycolipid microenvironment, a milieu playing an important role in cognitive functions. Old females experienced memory impairment even at basal conditions, which was additionally amplified by stress. On the other hand, the memory of young females was not disrupted. Stress recovery was followed by a microglial decrease and an increase in astrocyte count in the hippocampal immune system. Since dysfunction of the brain immune system could contribute to disturbed synaptogenesis, we analyzed neuroplastin expression and the lipid environment. Neuroplastin microenvironments were explored by analyzing immunofluorescent stainings using a newly developed Python script method. Stress reorganized glycolipid microenvironment in the Cornu Ammonis 1 (CA1) and dentate gyrus (DG) hippocampal regions of old females but in a very different fashion, thus affecting neuroplasticity. The postulation of four possible neuroplastin environments pointed to the GD1a ganglioside enrichment during reproductive senescence of stressed females, as well as its high dispersion in both regions and to GD1a and GM1 loss in the CA1 region. A specific lipid environment might influence neuroplastin functionality and underlie synaptic dysfunction triggered by a combination of aging and chronic stress.

Double check discharge planning to improve the results of a heart failure programme

Background

Reduction of readmissions in heart failure (HF) patients is a main goal of HF programmes. Establishing a discharge planning for the patient and coordinating it with primary care teams are key aspects for their success.

Purpose

Evaluate whether a double check discharge planning based on adding face-to-face joint weekly sessions with primary care managers to the conventional electronic communication of care plan reduces 6-month readmission and 6-month mortality.

Methods

We evaluated all patients discharged from hospital with HF as primary diagnosis between September 2017 and January 2019. We compared outcomes between patients discharged during Period #1 (single check; September 2017 - April 2018) and those discharged during Period #2 (double check; May 2018 - January 2019).

Primary endpoint was the combined endpoint of all-cause death or all-cause hospitalization 6 months after discharge from the index hospitalization.

Results

The study enrolled 317 patients: 182 in Period #1 and 135 in Period #2.

Mean age was 76±9 years. There was a higher proportion of patients with diabetes and COPD in Period #1, with no differences in other baseline characteristics.

The combined endpoint of all cause-death and all-cause hospitalization at 6 months was significantly reduced in patients in the double check discharge planning group (27% vs. 16%, p 0.021).

Conclusions

In a HF programme, the addition of a double check discharge planning based on having joint weekly sessions with primary care managers on top of the conventional electronic communication of care plan reduces 6-month readmission and 6-month mortality.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Hospital Universitari de Bellvitge

Effectiveness of nurse-led hospital-based heart failure programmes in octagenarians and nonagenarians: is age important?

Background

Efficacy of HF programmes in oldest old (octogenarians and nonagenarians) has not been fully explored.

Methods

We conducted a natural experiment evaluating all patients after hospitalization for heart failure as primary diagnosis between January 2017 and January 2019. We compared outcomes between patients discharged during Period #1, before the implementation of the program with patients discharged during Period #2, after the implementation of the 7-step bundle of interventions. We explored the interaction between age group (<80 vs. ≥80 years old) by the intervention modality (HF programme vs. usual care). Primary end-point was the combined end-point of all-cause death or all-cause hospitalization at 6 months after discharge from the index hospitalization.

Results

The study enroled 440 patients. Mean age of the whole cohort was 75±9 years. In the oldest old subgroup (n=160), mean age was 84±3. No differences were found in baseline characteristics of patients between usual care and HF program. 30-day all-cause readmission was significantly reduced in patients in the HF programme group compared to patients in the usual care group in both age strata. In unadjusted Cox regression analyses in the oldest old group, management of patients in the HF programme was significanty associated with a reduction in the risk of the primary end-point (HR: 0.50; 95% CI [0.29–0.85]; p=0.011).

Conclusions

Management of patients in a nurse-led integrated care-based heart failure programme results in reduction of all-cause death or all-cause hospitalizations in oldest old patients.

Event-free survival cumulative curves.

Funding Acknowledgement

Type of funding source: None

Epidemiology of potassium derangements among chronic cardiovascular, metabolic and renal conditions: a population-based analysis data from more than 375,000 individuals

Introduction

In patients with chronic cardiovascular, metabolic and renal disorders, potassium (K)+ homeostasis is often delicate, especially in the presence of renin-angiotensin-aldosterone system inhibition (RAASI) and/or diuretic therapies. In this context, current clinical practical guidelines for the management of these patients recommend close monitoring of renal function and K+ levels, particularly in the presence of drug titration. Nevertheless, very limited epidemiological data on their importance at a population level is available.

Purpose

The objectives of the present analysis are to estimate the prevalence of potassium (K+) derangements in five key chronic cardiovascular, metabolic and renal conditions at the population level, its use of RAASI medication and describe potassium derangements among RAASI users.

Methods

We used data from more than 375,000 individuals 55 years of age or older included in the population-based healthcare database of a public Institute of Health between 2015 and 2017. The conditions of interest were chronic heart failure (CHF), chronic kidney disease (CKD), diabetes mellitus (DM), ischemic heart disease (IHD), and hypertension (HTN). RAASI medications included angiotensin converting enzyme inhibitors, angiotensin II receptor blockers, mineralocorticoid receptor antagonists (MRAs), and rennin inhibitors. Hyperkalemia was defined as K+ levels >5.0 mEq/L and hypokalemia as K+ <3.5 mEq /L

Results

The prevalence of chronic cardiovascular, metabolic and renal conditions was high, particularly of HTN (48.2–48.9%). The prevalence of hyperkalemia was ranging between 10% and 25% depending of the condition, more frequent in CKD and less frequent in HTN patients. In figure, we display the prevalence of hyperkalemia among individuals with each of the relevant chronic conditions, January 1st, 2016 and January 1st, 2017. Use of at least one RAASI medication was very prevalent in HTN patients (75.2–77.3%). Among RAASI users, the frequency of K+ derangements and mainly of hyperkalemia was very noticeable (12% overall), especially in patients with CKD, CHF, elderly individuals, and users of MRAs. Hypokalemia was less frequent (1%).

Conclusion

The high prevalence of K+ derangements and predominantly hyperkalemia among RAASI users highlights the real-world relevance of K+ derangements and the importance of close monitoring and management of K+ levels in routine clinical practice. This is likely to benefit a large number of patients, particularly those at higher risk.

Figure 1. Prevalence of hyperkalemia

Funding Acknowledgement

Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Josep Comin-Colet and Miguel Cainzos-Achirica have participated in other research projects funded by unrestricted grants from Vifor Pharma

Association between self-care and prognosis in 1123 patients with chronic heart failure

Background

Self-care is a crucial factor in the education of patients with heart failure (HF) and directly impacts in the progression of the disease. However, little is published about its major clinical implications as admission or mortality in patients with HF.

Aims and methods

The aim of the study was to analyze time to admission due to acute heart failure and mortality associated with poor self-care in patients with chronic HF.

We prospectively recruited consecutive patients with stable chronic HF referred to a nurse-led HF programme. Selfcare was evaluated at baseline with the 9 item European Heart Failure Self-Care Behavior Scale. Scores were standardized and reversed from 0 (worst selfcare) to 100 (better self care). For the purpose of this study we analyzed the associations of worse self-care (defined as scores below the lower tertile of the scale) with demographic, disease-related (clinical) and psychosocial factors in all patients at baseline.

Results

We included 1123 patients, mean age 72±11, 639 (60%) were male, mean LVEF 45±17 and 454 (40,4%) were in NYHA class III or IV. Mean score of the 9-item ESCBE was 69±28. Score below 55 (lower tertile) defined impaired selfcare behaviour.

Those patients with worse self-care had more ischaemic heart disease, more COPD, and they achieved less distance in the 6 minute walking test. Regarding psychosocial items patients in lower tertile of self-care needed a caregiver more frequently, they present more cognitive impairment, depressive symptoms and worse score in terms of health self-perception.

Multivariate Cox Models showed that a score below 55 points in 9-item ESCBE was independently associated with higher readmission due to acute heart failure [HR 1.26 (1.02–1.57), p value=0.034] and with mortality [HR 1.24 CI95% (1.02–1.50), p value=0.028]

Conclusion

Poor self-care measured with the modified 9-item ESCBE was associated with higher risk of admission due to acute decompensation and higher risk of mortality in patients with chronic heart failure.

These results highlight the importance of assessing self-care and provide measures to improve them.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Hospital Univesitario de Bellvitge

A population-based analysis in 375,233 cases of heart failure stages A, B and C. Real world epidemiology of prevalence and temporal trends in South-European populations

Background

Prevalence of congestive heart failure (CHF) and predisposing conditions has described previously. Most of these studies evaluated centre-European or north-American populations. However, the prevalence and evolutionary changes of Heart Failure stages A, B and C has not been fully elucidated in Mediterranean cohorts.

Purpose

To estimate the prevalence of CHF (HF Stage C) and four additional key chronic cardiovascular, metabolic and renal conditions predisposing to the development of CHF (HF Stages A and B) at a population level in a south-European healthcare area. We analysed the evolutionary changes in the prevalence in these five conditions.

Methods

In a healthcare area of 1,3Millions inhabitants, we extracted health related information of all individuals ≥55 years old. We analysed data of 375,233 individuals included in the population-based healthcare database of a public Institute of Health between 2015 and 2017. The conditions of interest were CHF, chronic kidney disease (CKD), diabetes mellitus (DM), ischemic heart disease (IHD) and hypertension (HTN).

Results

The prevalence of chronic conditions was high, particularly of HTN (48.2–48.9%) and DM individuals (14.6–14.8%). The other conditions were less frequent, with prevalence around 2–4% for IHD, 5–9% for CKD and 2–4% for CHF (Table). However, the less frequent conditions had a striking upward trend with over 1,500 new prevalent cases per year between 2015 and 2017 for CHF (45% relative increase), more than 2,500 new prevalent cases for IHD (67% relative increase) and more than 4,000 new prevalent cases per year for CKD (44% relative increase).

Conclusion

In this south European cohort, there were a high prevalence of HTN and DM as risk factors and a significant trend of increasing prevalence in high cost chronic conditions such as CHF, IHD and CKD.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): The present study was funded by an unrestricted research grant from Vifor Pharma.

Long-term effectiveness of a nurse-led 7-step transitional intervention programme in heart failure

Background

Reduction of 30-day readmission in heart failure (HF) patients is a main goal of health-care systems. Programmes to decrease 30-day readmission have successfully reduced it but have failed to neither maintain benefit afterwards nor decrease mortality. Moreover, in many cases the price of reducing 30-day readmission is a mortality increase.

Purpose

Evaluate whether the impact of a fully nurse-led HF programme directed to reduce 30-day readmission and mortality extends to longer periods of time, including 90 days and 180 days after discharge.

Methods

We evaluated all patients discharged from hospital with HF as primary diagnosis between January 2017 and January 2019. We compared outcomes between patients discharged during Period #1 (pre-programme; Jan 2017 - Aug 2017) and those discharged during Period #2 (HF programme; Sept 2017 - Jan 2019).

Primary endpoint was the combined endpoint of all-cause death or all-cause hospitalization 90 days and 180 days after discharge from the index hospitalization.

Results

The study enrolled 440 patients: 123 in Period #1 and 317 in Period #2.

Mean age was 75±9 years. There was a higher proportion of female patients in Period #2 (38.2% vs 26.8%, p=0.025), with no differences in other baseline characteristics.

The combined endpoint of all cause-death and all-cause hospitalization was significantly reduced in patients in the HF programme group, both at 90 days [OR 0.37 (0.22–0.63), p<0.001] and at 180 days [OR 0.27 (CI 0.17–0.43), p<0.001]. Such a decrease was at expense of a reduction in cardiovascular (CV) hospitalization and HF hospitalization.

There were no differences between groups in mortality [OR 0.96 (0.18–5.00), p=0.293].

Conclusions

A fully nurse-led HF programme reduces the combined endpoint of all-cause death and all-cause hospitalization both at 90 days and 180 days after an index discharge for HF.

Such a decrease is driven by a reduction of CV and HF hospitalization, which are maintained over time. There were no differences between groups in mortality.

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Hospital Universitari de Bellvitge

A randomized comparison trial of culturally adapted HIV prevention approaches for Native Americans reducing trauma symptoms versus substance misuse: The Healing Seasons protocol

Native Americans (NA) experience interrelated risks of trauma exposure, substance use, and HIV risk behaviors that put them at increased risk for HIV infection. Despite these known risk factors, there are very few published randomized trials testing interventions to reduce trauma-related symptoms and substance misuse among NA.

METHODS

The Healing Seasons study is a randomized comparsion trial of two counseling strategies, Narrative Exposure Therapy (NET) addressing PTSD or Motivational interviewing with cognitive behavioral therapy skills training (MIST) addressing substance misuse as a means to prevent HIV among NA. Using a community-based participatory research approach, we adapted both evidence-based interventions to be specific to the risk contexts and realities of NA and to include psychoeducational and skill-building components that include cultural-specific stories, virtues, and traditional treatment strategies. Participants, 16 years and older, were recruited from a Pacific Northwest tribal community, screened over the phone, enrolled in person, and randomized in equal numbers to NET or MIST. We stratified by age (16-29 years and 30 or older) and gender (male or female identified) to ensure balance between treatment arms. The primary outcomes were number of sex partners and frequency of sexual acts (with and without condoms), sex under the influence of substances, frequency of substance use, and PTSD severity.

DISCUSSION

Behavioral interventions for NA are needed to prevent HIV risk behaviors when faced with trauma symptoms and substance misuse. This study will provide evidence to determine feasibility and efficacy of addressing related risk factors as part of counseling-based HIV prevention intervention to reduce sexual risk among this population.

TRIAL REGISTRATION

ClinicalTrials.gov number, NCT03112369, registered April 12, 2017.

Lipostatic Mechanisms Preserving Cerebellar Lipids in MPTP-Treated Mice: Focus on Membrane Microdomains and Lipid-Related Gene Expression

The cerebellum is an essential component in the control of motor patterns. Despite dramatic alteration of basal ganglia morpho-functionality in Parkinson's disease (PD), cerebellar function appears to be unaffected by the disease. Only recently this brain structure has been proposed to play compensatory roles in PD-induced motor dysfunction, particularly during the initial asymptomatic stages of PD. In PD subjects and animal models of PD, such as MPTP-treated mice, brain structures other than basal ganglia are also affected by the disease, including cortical areas not involved in motor control. Thus, it is noteworthy that the cerebellum remains unaffected. In the present study, we have analyzed the lipid composition of membrane microdomains [lipid rafts (LR) and non-raft domains] and assessed the expression levels of genes encoding enzymes synthesizing membrane-related lipids. The outcomes revealed that membrane domain lipids in cerebellum are highly preserved both in control and MPTP-treated mice as compared to control animals. Likewise, only small, mostly not significant, changes were observed in the expression of lipid-related genes in the cerebellum. Indeed, most changes were related to aging rather than to the exposure to the neurotoxin. Conversely, in the same animals, lipid composition, and gene expression were dramatically altered in the occipital cortex (OC), a brain area unrelated to the control of motor function. PCR and immunohistochemical analyses of both brain areas revealed that dopamine transporter (DAT) mRNA and protein were expressed in OC but not in the cerebellum. As MPTP neurotoxicity requires the expression of DAT to access intracellular compartments, we hypothesized that the absence of DAT in cerebellum hampers MPTP-induced toxicity. We conclude that cerebellum is endowed with efficient mechanisms to preserve nerve cell lipid homeostasis, which greatly maintain the stability of membrane microdomains involved in synaptic transmission, signal transduction, and intercellular communication, which together may participate in the compensatory role of the cerebellum in PD symptomatology.

Differential Aggregation and Phosphorylation of Alpha Synuclein in Membrane Compartments Associated With Parkinson Disease

The aggregation of α-synuclein (α-syn) is a major factor behind the onset of Parkinson’s disease (PD). Sublocalization of this protein may be relevant for the formation of multimeric α-syn oligomeric configurations, insoluble aggregates that form Lewy bodies in PD brains. Processing of this protein aggregation is regulated by associations with distinct lipid classes. For instance, instability of lipid raft (LR) microdomains, membrane regions with a particular lipid composition, is an early event in the development of PD. However, the relevance of membrane microdomains in the regulation and trafficking of the distinct α-syn configurations associated with PD remains unexplored. In this study, using 6- and 14-month-old healthy and MPTP-treated animals as a model of PD, we have investigated the putative molecular alterations of raft membrane microstructures, and their impact on α-syn dynamics and conformation. A comparison of lipid analyses of LR microstructures and non-raft (NR) fractions showed alterations in gangliosides, cholesterol, polyunsaturated fatty acids (PUFA) and phospholipids in the midbrain and cortex of aged and MPTP-treated mice. In particular, the increase of PUFA and phosphatidylserine (PS) during aging correlated with α-syn multimeric formation in NR. In these aggregates, α-syn was phosphorylated in pSer129, the most abundant post-transductional modification of α-syn promoting toxic aggregation. Interestingly, similar variations in PUFA and PS content correlating with α-syn insoluble accumulation were also detected in membrane microstructures from the human cortex of incidental Parkinson Disease (iPD) and PD, as compared to healthy controls. Furthermore, structural changes in membrane lipid microenvironments may induce rearrangements in raft-interacting proteins involved in other neuropathologies. Therefore, we also investigated the dynamic of other protein markers involved in cognition and memory impairment such as metabotropic glutamate receptor 5 (mGluR5), ionotropic NMDA receptor (NMDAR2B), prion protein (PrPc) and amyloid precursor protein (APP), whose activity depends on membrane lipid organization. We observed a decline of these protein markers in LR fractions with the progression of aging and pathology. Overall, our findings demonstrate that lipid alterations in membranous compartments promoted by brain aging and PD-like injury may have an effect on α-syn aggregation and segregation in abnormal multimeric structures.

In-Out-Test: A New Paradigm for Sorting the Wheat from the Chaff in Prodromal Alzheimer's Disease

BACKGROUND

Assessment of hippocampal amnesia is helpful to distinguish between normal cognition and mild cognitive impairment (MCI), but not for identifying converters to dementia. Here biomarkers are useful but novel neuropsychological approaches are needed in their absence. The In-out-test assesses episodic memory using a new paradigm hypothesized to avoid reliance on executive function, which may compensate for damaged memory networks.

OBJECTIVE

To assess the validity of the In-out-test in identifying prodromal Alzheimer's disease (PAD) in a clinical setting, by comparing this to the Free and Cued Selective Reminding Test (FCSRT) and cerebrospinal fluid biomarkers.

METHODS

A cross-sectional study of 32 cognitively healthy, 32 MCI, and 30 progressive dementia subjects. All participants were given both the In-out-test and the FCSRT; 40 of them also received a lumbar puncture.

RESULTS

Internal consistency was demonstrated using Cronbach Alpha (r = 0.81) and Inter-rater reliability with Kappa (k = 0.94). Intraclass correlation (ICC) for test-retest reliability: r = 0.57 (p = 0.57). ICC between the In-out-test and FCSRT r = 0.87 (p = 0.001). ICC between the In-out-test and Aβ42 and P-tau/Aβ42 for controls: 0.73 and 0.75, respectively; P-tau for MCI: 0.77 and total sample: 0.70; Aβ42 for dementia: 0.71. All ICC measures between FCSRT and biomarkers were ≤0.264. AD diagnosis: In-out-test k = 0.71; FCSRT k = 0.49. PAD diagnosis (N = 35): In-out-test k = 0.69; FCSRT k = 0.44.

CONCLUSIONS

The In-out-test detected prodromal AD with a higher degree of accuracy than a conventional hippocampal-based memory test. These results suggest that this new paradigm could be of value in clinical settings, predicting which patients with MCI will go on to develop AD.

Estrogen Interactions With Lipid Rafts Related to Neuroprotection. Impact of Brain Ageing and Menopause

Estrogens (E2) exert a plethora of neuroprotective actions against aged-associated brain diseases, including Alzheimer's disease (AD). Part of these actions takes place through binding to estrogen receptors (ER) embedded in signalosomes, where numerous signaling proteins are clustered. Signalosomes are preferentially located in lipid rafts which are dynamic membrane microstructures characterized by a peculiar lipid composition enriched in gangliosides, saturated fatty acids, cholesterol, and sphingolipids. Rapid E2 interactions with ER-related signalosomes appear to trigger intracellular signaling ultimately leading to the activation of molecular mechanisms against AD. We have previously observed that the reduction of E2 blood levels occurring during menopause induced disruption of ER-signalosomes at frontal cortical brain areas. These molecular changes may reduce neuronal protection activities, as similar ER signalosome derangements were observed in AD brains. The molecular impairments may be associated with changes in the lipid composition of lipid rafts observed in neurons during menopause and AD. These evidences indicate that the changes in lipid raft structure during aging may be at the basis of alterations in the activity of ER and other neuroprotective proteins integrated in these membrane microstructures. Moreover, E2 is a homeostatic modulator of lipid rafts. Recent work has pointed to this relevant aspect of E2 activity to preserve brain integrity, through mechanisms affecting lipid uptake and local biosynthesis in the brain. Some evidences have demonstrated that estrogens and the docosahexaenoic acid (DHA) exert synergistic effects to stabilize brain lipid matrix. DHA is essential to enhance molecular fluidity at the plasma membrane, promoting functional macromolecular interactions in signaling platforms. In support of this, DHA detriment in neuronal lipid rafts has been associated with the most common age-associated neuropathologies, namely AD and Parkinson disease. Altogether, these findings indicate that E2 may participate in brain preservation through a dual membrane-related mechanism. On the one hand, E2 interacting with ER related signalosomes may protect against neurotoxic insults. On the other hand, E2 may exert lipostatic actions to preserve lipid balance in neuronal membrane microdomains. The different aspects of the emerging multifunctional role of estrogens in membrane-related signalosomes will be discussed in this review.

Lipid Raft Alterations in Aged-Associated Neuropathologies

Lipid rafts are membrane microdomains particularly enriched in cholesterol, sphingolipids and saturated fatty acids. These microstructures play a key role in a plethora of mechanisms involved in cell signaling, synapsis, cell-cell communication and cell survival. In the last years, increasing evidence indicate that lipid rafts may be altered in age-related neuropathologies, such as Alzheimer's disease and Parkinson disease even at asymptomatic stages. In particular, important changes in raft lipid composition are observed with the progression of these diseases, then inducing alterations in their physicochemical properties. Furthermore, these phenomena contribute to neuropathological events related to amyloidogenesis, aberrant protein aggregation and toxic cell signalling. In this review, we discuss some relevant data on the age-related molecular changes occurring in lipid rafts since the first stages of these neurodegenerative diseases. Further characterization of specific parameters associated with alterations of these microdomains may provide potential tools of diagnosis and prediction of these neuropathologies.

Double rare-earth nanothermometer in aqueous media: opening the third optical transparency window to temperature sensing

Owing to the alluring possibility of contactless temperature probing with microscopic spatial resolution, photoluminescence nanothermometry at the nanoscale is rapidly advancing towards its successful application in biomedical sciences. The emergence of near-infrared nanothermometers has paved the way for temperature sensing at the deep tissue level. However, water dispersibility, adequate size at the nanoscale, and the capability to efficiently operate in the second and third biological optical transparency windows are the requirements that still have to be fulfilled in a single nanoprobe. In this work, these requirements are addressed by rare-earth doped nanoparticles with core/shell-architecture, dispersed in water, whose excitation and emission wavelengths conveniently fall within the biological optical transparency windows. Under heating-free 800 nm excitation, double nanothermometry is realized either with Ho³⁺-Nd³⁺ (1.18-1.34 μm) or Er³⁺-Nd³⁺ (1.55-1.34 μm) NIR emission band ratios, both displaying equal thermal sensitivities around 1.1% °C^-1. It is further demonstrated that, along with the interionic energy transfer processes, the thermometric properties of these nanoparticles are also governed by the temperature dependent energy transfer to the surrounding solvent (water) molecules. Overall, this work presents a novel water dispersible double ratiometric nanothermometer operating in the second and third biological optical transparency windows. The temperature dependent particle-solvent interaction is also presented, which is critical for e.g. future in vivo applications.

Covering the optical spectrum through collective rare-earth doping of NaGdF4 nanoparticles: 806 and 980 nm excitation routes

Sensitization of numerous emission bands (from ultraviolet to near-infrared) in rare-earth doped multilayered nanoparticles: 806 versus 980 nm excitation.

Lipid raft ER signalosome malfunctions in menopause and Alzheimer's disease

The increase in the incidence of Alzheimer's disease (AD) in old women may be attributable to estrogen deficiency, and estrogen replacement therapy may be useful in preventing or delaying the onset of this disease. In neuronal membranes, 17 beta-estradiol interacts with estrogen receptors (mERs) located in lipid raft signalosomes which trigger neuroprotective responses by anchoring to scaffolding caveolin-1 complexed with other proteins. We suggest that mER-signalosome malfunctions in AD and by menopause due to development of aberrations in these microstructures. Here, we report that mER dissociates from a voltage-dependent anion channel (VDAC), and that progressive dephosphorylation of VDAC1 enhances neurotoxicity. mER dissociates from caveolin-1 and other neuroprotective proteins, including insulin-like growth factor 1 receptor beta. Similar signalosome disarrangements are observed in AD patients. Moreover, in AD, lipid rafts exhibit alterations in lipid composition, and these changes cause an increase in liquid-ordered as compared to controls. Together, the data show that AD and menopause lead to disruption in the lipid raft structure, and disfunctioning of ER alpha and other neuroprotectors integrated into these signalosomes.

Plasma phospholipid fatty acid composition and desaturase activity in women with gestational diabetes mellitus before and after delivery

AIMS

Analyze plasma phospholipid fatty acids (PPFA) composition and desaturase activity in women with gestational diabetes (GDM) and in women with a normal glucose tolerance (NGT) before and after delivery, and to evaluate the possible relationship between desaturase activity and inflammatory parameters.

METHODS

PPFA composition was analyzed by gas chromatography in 21 women with GDM and from 21 with NGT, during the third trimester of pregnancy and 6 months after delivery. We used fatty acid product-to-precursor ratios to estimate desaturase activity, and we also measured in all women interleukins six and ten, tumor necrosis factor alpha and C-reactive protein.

RESULTS

No significant differences were observed between NGT and GDM women in terms of PPFA composition, both in pregnancy and after pregnancy. Estimated desaturase Δ9-18 activity was significantly higher, and estimated desaturase Δ5 activity was significantly lower during pregnancy in all women. We observed no correlations between inflammatory markers and desaturases activity, during or after pregnancy, in both groups.

CONCLUSIONS

Our data suggest that GDM does not influence PPFA composition and desaturase activity during pregnancy. In addition, late pregnancy characterized by hyperinsulinemia appears to upregulate desaturase Δ9-18 activity in NGT and GDM women.

Hippocampal Lipid Homeostasis in APP/PS1 Mice is Modulated by a Complex Interplay Between Dietary DHA and Estrogens: Relevance for Alzheimer's Disease

Current evidence suggests that lipid homeostasis in the hippocampus is affected by different genetic, dietary, and hormonal factors, and that its deregulation may be associated with the onset and progression of Alzheimer's disease (AD). However, the precise levels of influence of each of these factors and their potential interactions remain largely unknown, particularly during neurodegenerative processes. In the present study, we have performed multifactorial analyses of the combined effects of diets containing different doses of docosahexaenoic acid (DHA), estrogen status (ovariectomized animals receiving vehicle or 17β-estradiol), and genotype (wild-type or transgenic APP/PS1 mice) in hippocampal lipid profiles. We have observed that the three factors affect lipid classes and fatty acid composition to different extents, and that strong interactions between these factors exist. The most aberrant lipid profiles were observed in APP/PS1 animals receiving DHA-poor diets and deprived of estrogens. Conversely, wild-type animals under a high-DHA diet and receiving estradiol exhibited a lipid profile that closely resembled that of the hippocampus of control animals. Interestingly, though the lipid signatures of APP/PS1 hippocampi markedly differed from wild-type, administration of a high-DHA diet in the presence of estrogens gave rise to a lipid profile that approached that of control animals. Paralleling changes in lipid composition, patterns of gene expression of enzymes involved in lipid biosynthesis were also altered and affected by combination of experimental factors. Overall, these results indicate that hippocampal lipid homeostasis is strongly affected by hormonal and dietary conditions, and that manipulation of these factors might be incorporated in AD therapeutics.

Anomalies occurring in lipid profiles and protein distribution in frontal cortex lipid rafts in dementia with Lewy bodies disclose neurochemical traits partially shared by Alzheimer's and Parkinson's diseases

Lipid rafts are highly dynamic membrane microdomains intimately associated with cell signaling. Compelling evidence has demonstrated that alterations in lipid rafts are associated with neurodegenerative diseases such Alzheimer's disease, but at present, whether alterations in lipid raft microdomains occur in other types of dementia such dementia with Lewy bodies (DLB) remains unknown. Our analyses reveal that lipid rafts from DLB exhibit aberrant lipid profiles including low levels of n-3 long-chain polyunsaturated fatty acids (mainly docosahexaenoic acid), plasmalogens and cholesterol, and reduced unsaturation and peroxidability indexes. As a consequence, lipid raft resident proteins holding principal factors of the β-amyloidogenic pathway, including β-amyloid precursor protein, presenilin 1, β-secretase, and PrP, are redistributed between lipid rafts and nonraft domains in DLB frontal cortex. Meta-analysis discloses certain similarities in the altered composition of lipid rafts between DLB and Parkinson's disease which are in line with the spectrum of Lewy body diseases. In addition, redistribution of proteins linked to the β-amyloidogenic pathway in DLB can facilitate generation of β-amyloid, thus providing mechanistic clues to the intriguing convergence of Alzheimer's disease pathology, particularly β-amyloid deposition, in DLB.

High-density lipoprotein oxidation in type 2 diabetic patients and young patients with premature myocardial infarction

BACKGROUND AND AIMS

ApoA-I can undergo oxidative changes that reduce anti-atherogenic role of HDL. The aim of this study was to seek any significant differences in methionine sulfoxide (MetO) content in the ApoA-I of HDL isolated from young patients with coronary heart disease (CHD), type 2 diabetics and healthy subjects.

METHODS AND RESULTS

We evaluated the lipid profile of 21 type 2 diabetic patients, 23 young patients with premature MI and 21 healthy volunteers; we determined in all patients the MetO content of ApoA-I in by MALDI/TOF/TOF technique. The typical MALDI spectra of the tryptic digest obtained from HDL plasma fractions all patients showed a relative abundance of peptides containing Met(112)O in ApoA-I in type 2 diabetic and CHD patients. This relative abundance is given as percentages of oxidized ApoA-I (OxApoA-I). OxApoA-I showed no significant correlations with lipoproteins in all patients studied, while a strong correlation emerged between the duration of diabetic disease and OxApoA-I levels in type 2 diabetic patients.

CONCLUSIONS

The most remarkable finding of our study lies in the evidence it produced of an increased HDL oxidation in patients highly susceptible to CHD. Levels of MetO residues in plasma ApoA-I, measured using an accurate, specific method, should be investigated and considered in prospective future studies to assess their role in CHD.

Aβ promotes VDAC1 channel dephosphorylation in neuronal lipid rafts. Relevance to the mechanisms of neurotoxicity in Alzheimer's disease

Voltage-dependent anion channel (VDAC) is a mitochondrial protein abundantly found in neuronal lipid rafts. In these membrane domains, VDAC is associated with a complex of signaling proteins that trigger neuroprotective responses. Loss of lipid raft integrity may result in disruption of multicomplex association and alteration of signaling responses that may ultimately promote VDAC activation. Some data have demonstrated that VDAC at the neuronal membrane may be involved in the mechanisms of amyloid beta (Aβ)-induced neurotoxicity, through yet unknown mechanisms. Aβ is generated from amyloid precursor protein (APP), and is released to the extracellular space where it may undergo self-aggregation. Aβ aggregate deposition in the form of senile plaques may lead to Alzheimer's disease (AD) neuropathology, although other pathological hallmarks (such as hyper-phosphorylated Tau deposition) also participate in this neurodegenerative process. The present study demonstrates that VDAC1 associates with APP and Aβ in lipid rafts of neurons. Interaction of VDAC1 with APP was observed in lipid rafts from the frontal and entorhinal cortex of human brains affected by AD at early stages (I-IV/0-B of Braak and Braak). Furthermore, Aβ exposure enhanced the dephosphorylation of VDAC1 that correlated with cell death. Both effects were reverted in the presence of tyrosine phosphatase inhibitors. VDAC1 dephosphorylation was corroborated in lipid rafts of AD brains. These results demonstrate that Aβ is involved in alterations of the phosphorylation state of VDAC in neuronal lipid rafts. Modulation of this channel may contribute to the development and progression of AD pathology.

Oestrogens as modulators of neuronal signalosomes and brain lipid homeostasis related to protection against neurodegeneration

Oestrogens trigger several pathways at the plasma membrane that exert beneficial actions against neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. Part of these actions takes place in lipid rafts, which are membrane domains with a singular protein and lipid composition. These microdomains also represent a preferential site for signalling protein complexes, or signalosomes. A plausible hypothesis is that the dynamic interaction of signalosomes with different extracellular ligands may be at the basis of neuronal maintenance against different neuropathologies. Oestrogen receptors are localised in neuronal lipid rafts, taking part of macromolecular complexes together with a voltage-dependent anion channel (VDAC), and other molecules. Oestradiol binding to its receptor at this level enhances neuroprotection against amyloid-β degeneration through the activation of different signal transduction pathways, including VDAC gating modulation. Moreover, part of the stability and functionality of signalling platforms lays on the distribution of lipid hallmarks in these microstructures, which modulate membrane physicochemical properties, thus favouring molecular interactions. Interestingly, recent findings indicate a potential role of oestrogens in the preservation of neuronal membrane physiology related to lipid homeostasis. Thus, oestrogens and docosahexaenoic acid may act synergistically to stabilise brain lipid structure by regulating neuronal lipid biosynthetic pathways, suggesting that part of the neuroprotective effects elicited by oestrogens occur through mechanisms aimed at preserving lipid homeostasis. Overall, oestrogen mechanisms of neuroprotection may occur not only by its interaction with neuronal protein targets through nongenomic and genomic mechanisms, but also through its participation in membrane architecture stabilisation via 'lipostatic' mechanisms.

Estrogen receptors in lipid raft signalling complexes for neuroprotection

Estrogens exert a plethora of actions conducted to brain preservation and functioning. Some of these actions are initiated in lipid rafts, which are particular microstructures of the plasma membrane. Preservation of lipid raft structure in neurons is essential for signal transduction against different injuries, such as Alzheimer's disease (AD). These membrane structures appear to be disrupted as this neuropathology evolves, and that may largely contribute to dysfunction of raft resident proteins involved in intracellular signalling. This review includes a survey of some protein interactions that are involved in the structural maintenance and signal transduction mechanisms for neuronal survival against AD. Particularly relevant are the rapid mechanisms developed by estrogen to prevent neuronal death, through membrane estrogen receptors (mER) interactions with a voltage-dependent anion channel (VDAC) and other protein markers within neuronal lipid rafts. These interactions may have important consequences in estrogen mechanisms to achieve neuroprotection against amyloid beta (Abeta-induced toxicity).

Membrane-initiated signaling of estrogen related to neuroprotection. "Social networks" are required

Numerous studies indicate that estrogens are crucial in normal brain functioning and preservation against different injuries. At the neuronal membrane, estrogens, binding to estrogen receptors (ERs) or other surface targets, exert rapid actions involving a plethora of signaling pathways that may converge in neuronal survival. Emerging work reveals that at least part of these actions may require the compartmentalization of ERs in signaling platforms, composed of macromolecular signaling proteins and particular lipid composition integrated in lipid rafts. These particular microstructures may provide the optimal microenvironment to trigger multiple ER interactions that may be crucial for neuroprotection against different brain impairments, such as Alzheimer's disease (AD). In this order of ideas, recent evidence has demonstrated that a membrane ER (mER) physically interacts with a voltage-dependent anion channel (VDAC) in lipid rafts from septal, hippocampal and cortical neurons, and these interactions may have important consequences in the alternative mechanisms developed by estrogens to achieve neuroprotection against amyloid beta (Aβ)-induced toxicity. This review includes a survey of some of the rapid mechanisms developed by estrogen to prevent neuronal death, and the ER interactions that are involved in the structural maintenance and signal transduction mechanisms important for neuronal survival against AD neuro-pathology. A special emphasis is put on the biological relevance of neuronal membrane VDAC in Aβ-related neurotoxicity, and the potential modulation of this channel as a part of a signaling complex with mER, which may be modified in AD brains.

Estradiol and tamoxifen differentially regulate a plasmalemmal voltage-dependent anion channel involved in amyloid-beta induced neurotoxicity

There is a wealth of information indicating that estradiol exerts rapid actions involved in neuroprotection and cognitive-enhancing effects. Some of these effects appear to delay onset, or even ameliorate, the neuropathology of Alzheimer's disease (AD), although some controversy exists about the beneficial brain effects of estrogen therapies. Therefore, it is crucial to better understand the mechanisms developed by 17β-estradiol to signal in the brain. At the neuronal membrane, the hormone can rapidly interact with estrogen receptors (mERs) or activate other receptors, such as G protein-coupled and ionotropic receptors. And the list of membrane signalling molecules modulated by estradiol in neurons is increasing. VDAC is a voltage-dependent anion channel, known as a mitochondrial porin which is also found at the neuronal membrane, where it appears to be involved in redox regulation, extrinsic apoptosis and amyloid beta neurotoxicity. Moreover, VDAC is present in neuronal lipid rafts, where it is associated with estrogen receptor α-like (mER), forming part of a macromolecular complex together with caveolin-1 and other signalling proteins related to neuronal preservation. Interestingly, we have recently found that 17β-estradiol rapidly promotes VDAC phosphorylation through the activation of protein kinase A (PKA) and Src-kinase, which may be relevant to maintain this channel inactivated. On the contrary, tamoxifen, a selective estrogen receptor modulator (SERM), provokes the dephosphorylation of VDAC, and eventually its opening, by activating a cascade of phosphatases, including protein phosphatase 2 (PP2A). This review will focus on the relevance of these novel findings in the alternative estrogen mechanisms to achieve neuroprotection related to AD.

Signalosomes in the brain: relevance in the development of certain neuropathologies such as Alzheimer's disease

Emerging data suggest that compartmentalization of signaling molecules into particular membrane compartments, or lipid rafts, may be at the basis of numerous activities related to neuronal preservation against different pathologies. These signaling platforms (signalosomes) are formed by complex lipid and protein that may interact to develop a plethora of different physiological responses upon activation by different extracellular stimuli, thereby contributing to neuroprotection. One of the first studied signalosomes involved in neuroprotection against Alzheimer's disease (AD) is constituted by estrogen receptor (ER), in association with scaffolding caveolin-1 and a voltage-dependent anion channel (VDAC). In this complex, ER plays a neuroprotective role partially through the modulation of VDAC activation, a porin involved in amyloid-beta-induced toxicity. Interestingly, ER and VDAC interactions appear to be altered in lipid rafts of AD brains, a phenomenon that may contribute to neuronal impairment. Alterations in lipid components of these subdomains may contribute to destabilization of this macrocomplex. These recent advances in the relevance of signaling platforms related to brain preservation, in particular against AD, are discussed in this work.

Voltage-dependent anion channel as a resident protein of lipid rafts: post-transductional regulation by estrogens and involvement in neuronal preservation against Alzheimer's disease

The voltage-dependent anion channel, VDAC, is present at the neuronal membrane, where it appears to participate, among others, in the extrinsic apoptotic pathway and in the modulation of amyloid-beta induced injury, suggesting the involvement of this channel in Alzheimer's disease (AD) neurotoxicity. VDAC is also highly concentrated in neuronal lipid raft microdomains of different mouse and human cognitive areas, where it has been shown associated with estrogen receptor alpha (ERα), as a part of a `signalosome' that may activate some intracellular signal transduction. At the plasma membrane level, estrogens and antiestrogens (tamoxifen) have been demonstrated to exert rapid antagonist effects on the activation of VDAC, through their distinct effects on the channel post-transductional modulation. Therefore, part of the alternative mechanisms of estrogen related to neuroprotection against amyloid-beta may involve VDAC phosphorylation, in order to maintain the channel in an unactivated (closing) state. Interestingly, VDAC-ERα association has been shown to be disrupted in neuronal lipid rafts of AD brains, in correlation with the aberrant lipid composition observed in these microstructures, suggesting that disturbance of protein interactions may be related to variation in the physico-chemical properties of these microdomains.

Role of estrogen receptor alpha in membrane-initiated signaling in neural cells: interaction with IGF-1 receptor

The mechanisms of action of estradiol in the nervous system involve nuclear-initiated steroid signaling and membrane-initiated steroid signaling. Estrogen receptors (ERs) are involved in both mechanisms. ERalpha interacts with the signaling of IGF-1 receptor in neural cells: ERalpha transcriptional activity is regulated by IGF-1 receptor signaling and estradiol regulates IGF-1 receptor signaling. The interaction between ERalpha and the IGF-1 receptor in the brain may occur at the plasma membrane of neurons and glial cells. Caveolin-1 may provide the scaffolding for the interaction of different membrane-associated molecules, including voltage-dependent anion channel, ERalpha and IGF-I receptor.

Plasma lipids and inflammation in active inflammatory bowel diseases

BACKGROUND

Ulcerative colitis (UC) and Crohn's disease (CD) can cause metabolic and inflammatory alterations.

AIM

To evaluate the relationships between inflammatory parameters, plasma lipids and phospholipid fatty acid (FA) composition in patients with active UC and CD.

METHODS

Diet, the Harvey-Bradshaw Activity Index (HBAI), inflammatory parameters, lipoproteins and FA composition were assessed in 60 CD and 34 UC.

RESULTS

No differences in clinical parameters were observed in the two groups. Total cholesterol correlated inversely with the number of bowel movements in both groups and directly with BMI in UC. Arachidonic acid correlated inversely with HBAI in UC and total and HDL cholesterol were inversely related to C-reactive protein (CRP) in CD while HDL correlated with CRP in UC. Docosapentaenoic acid was the only polyunsaturated n-3 FA that was correlated to CRP in both groups. Total cholesterol was independently associated in the multiple regression analysis with the number of bowel movements and systemic inflammation.

CONCLUSIONS

Total and LDL cholesterol were lower in the active UC and CD than in the healthy subjects and were correlated with the systemic inflammatory status. Phospholipid FA composition was correlated to the systemic inflammatory status, but was unrelated to dietary intake and intestinal disease activity.

Depression in War-related Post Traumatic Stress Disorder and the Enduring Personality Change After Catastrophic Experience (F62.0) a 15-year Follow-up

Objective:

This study was a 15-year follow-up examination. Many patients with F 62.0 and post traumatic stress disorder (PTSD) have symptoms of depression. The authors’ objective is to analyze symptoms of depression in F 62.0 and PTSD.

Method:

The subjects were 200 male psychiatric patients at a Clinic of psychiatry medical center Banjaluka and psychiatry department of with war-related PTSD. Post traumatic stress syndrom-PTSS scale and 21-item Hamilton Rating Scale for Depression-HAMD was used to assess state measures of symptom severity; from 3 months to 15 years after returning from the war.

Results:

The symptoms of prolonged PTSS (with duration between six moths and two years) had been founded at 54%, and 32% of patients had no diagnosis PTSD. The enduring personality change after catastrophic experience (F 62.0) had been found at 14% patients (with duration more than two years), 19% met HAMD Diagnostic Criteria for major depressive disorder.

The enduring personality exchange F 62.0 had been found at 8% patients and 16% met HAMD Diagnostic Criteria for major depressive disorder 15 years after returning from the war.

Conclusions:

The statistical relationship between level of combat exposure and PTSD symptoms at 15 years, suggests that it may take time for the consequences of traumatic exposure to become apparent. Moreover, degree of exposure may be important in predicting the eventual development of symptoms and precipitation of F 62.0 enduring personality exchange. Continued follow-up will address the evolution of PTSD symptoms in war related PTSD.

Modulation of Abeta-induced neurotoxicity by estrogen receptor alpha and other associated proteins in lipid rafts

Some evidences have demonstrated the participation of estrogen receptors (ERs) in rapid, non-genomic actions of estrogen to promote neuroprotection against different toxic agents. However, there is still very little information about the structural nature of these receptors and the manner these proteins may be integrated into the plasma membrane. One of the plausible possibilities is that they may be localized in lipid rafts microstructures where they would be associated with other, still unknown, molecules which may modulate their physiological activities related to cell survival. In this work, we have identified in caveolar fractions of murine septal and hippocampal neurons a membrane-related ER shown to physically interact with, both, a voltage-dependent anion channel and scaffold protein caveolin-1.

Desaturase activities and metabolic control in type 2 diabetes

The aim of this study was to elucidate the effects of a poor glycemic control on fatty acid composition and desaturase activities in type 2 diabetic patients. Plasma phospholipid fatty acid composition and desaturase activities (estimated from fatty acid product to precursor ratios) were measured in 30 type 2 diabetic patients during poor metabolic control and after achieving a good metabolic control. Significant changes were recorded in the percentages of palmitic, stearic, dihomo-gamma-linolenic, docosatetraenoic and docosapentaenoic acid. The delta-5 desaturase activity was significantly higher with poor than with good metabolic control. The changes identified in plasma phospholipid fatty acid composition and the desaturase activity in type 2 diabetic patients go in the opposite direction to those described in similar conditions in type 1 diabetic patients and may be relevant to a better understanding of the role of metabolic control in the progression of chronic complications in type 2 diabetic patients.

Voltage-dependent anion channel (VDAC) participates in amyloid beta-induced toxicity and interacts with plasma membrane estrogen receptor alpha in septal and hippocampal neurons

Voltage-dependent anion channel (VDAC) is a porin known by its role in metabolite transport across mitochondria and participation in apoptotic processes. Although traditionally accepted to be located within mitochondrial outer membrane, some data has also reported its presence at the plasma membrane level where it seems to participate in regulation of normal redox homeostasis and apoptosis. Here, exposure of septal SN56 and hippocampal HT22 cells to specific anti-VDAC antibodies prior to amyloid beta (Abeta) peptide was observed to prevent neurotoxicity. In these cell lines, we identified a VDAC form associated with the plasma membrane that seems to be particularly abundant in caveolae. The two membrane-related isoforms of estrogen receptor alpha (mERalpha) (80 and 67 kDa), known in SN56 cells to participate in estrogen-induced neuroprotection against Abeta injury, were also observed to be present in caveolae. Interestingly, we demonstrated for the first time that both VDAC and mERalpha interact at the plasma membrane of these neurons as well as in microsomal fractions of the corresponding murine septal and hippocampal tissues. These proteins were also shown to associate with caveolin-1, thereby corroborating their presence in caveolar microdomains. Taken together, these results suggest that VDAC-mERalpha association at the plasma membrane level may participate in the modulation of Abeta-induced cell death.

Estrogen inhibition of norepinephrine responsiveness is initiated at the plasma membrane of GnRH-producing GT1-7 cells

The modulatory action of estradiol (E2) on the GnRH network can be exerted indirectly on presynaptic neurons or directly on estrogen receptors (ERs) located within GnRH hypothalamic neurons. Using the GnRH-producing GT1-7 cell line, we have investigated whether E2 is able to modify the response of these cells to norepinephrine (NE) stimulation. A 48-h exposure of GT1-7 cells to 10 nM E2 reduced NE-induced cAMP accumulation. However, 15-min exposure was enough to induce this inhibitory action, provided that a hormone-free period of 48 h after steroid treatment was allowed. Furthermore, this effect was mimicked by E2 coupled to (E-BSA), indicating that it may be exerted through a membrane-mediated mechanism. In addition, competition experiments using E-BSA coupled to fluorescein isothiocyanate (FITC) revealed the presence of cell membrane-binding sites for E2. Binding of E-BSA coupled to FITC was blocked by preincubation of cells with either E2, antiestrogen ICI 182 780, or tamoxifen. Moreover, fluorescence staining of non-permeabilized cells with antibodies against receptors alpha and beta confirmed the presence of both receptor subtypes at the cell membrane. To determine the nature of the ER involved in this response, specific agonists for ERalpha 4,4',4''-(4-propyl-[1H]pyrazole-1,3,5-triyl)tris-phenol (PPT) and ERbeta 2,3-bis(4-hydroxyphenyl)-propionitrile (DPN) were used. Since PPT, but not DPN, reproduced the effect of E2, it is suggested that estrogen-induced modulatory action on NE responsiveness was mediated by the ERalpha isoform. Taken together, these results indicate that E2 modulates the adrenergic sensitivity of GT1-7 cells by a mechanism compatible with the activation of membrane-associated ERs.