Zihan Liu
The prevalence of emotional disorders is high among people who seek help from general medical services. In most international studies, the prevalence of depression and anxiety ranges from 3.6% to 13.1%. Co-morbid emotional problems such as depression and anxiety are associated with a decreased quality of life, impaired self-management behaviors, and a diminished perception of disease control in medical patients.
Unfortunately, most of the patients with emotional problems are not properly treated. For example, an investigation of the Epidemiology of Mental Disorders (ESEMeD) of 21,400 adults from six European countries indicated that the lifetime prevalence of major depression was 13.4%, but only 4.6% of the depressive patients accepted antidepressants treatment.
Moreover, we believe that a high concordance in the assessment of psychological needs rated by patients and medical staff is another important precondition for an adequate treatment of patients with depression or anxiety. However, it has been shown that doctor and patient attitudes relating to mental health services are not always consistent (19,20). Richards et al. reported that 37% and 12% of patients with psoriasis were identified as probable clinical cases for anxiety disorder and depression respectively. Dermatologists identified only 39% of the patients with significant psychological difficulties during the consultation. The level of concordance between patients’ ratings and dermatologists’ ratings regarding the presence of anxiety or depression was low (kappa values of 0.24 and 0.26 respectively)
Methods
Research design and sampling
This cross-sectional survey was approved by the Ethics Committee of West China Hospital of Sichuan University and was conducted from October to November, 2013. Participants in this study were inpatients recruited from 10 voluntary departments (Oncology, Internal Cardiology, Respiratory Medicine, Rehabilitation, Geriatrics and Gerontology, General Practice, Pain Management, Rheumatology, Hepatic Surgery, and Thyroid and Breast Surgery) of West China Hospital, a major tertiary general hospital in Chengdu, China. All hospitalized patients of the listed departments were selected as potential participants
Instruments and measures
Results
Participants
From the 1,662 hospitalized patients which could be approached at the 10 departments that day, 151 patients were excluded based on the exclusion criteria. Among the included 1,511 hospitalized patients, 149 patients refused to participate in the study with “lack of time” and “not interested” as the most common reasons; 89 participants were excluded because their doctors did not respond. The overall response rate was 84.25% and the final sample consisted of 1,273 participants. The sociodemographic characteristics of the study group. The mean (SD) age was 53.1±16.3 years; 58.37% of the sample were men (n=743).
Discussion
The ability to recognize emotional problems is believed to be one of the most important influencing factors for the proper treatment of patients with depression or anxiety. Unfortunately, patients’ and doctors’ ability to recognize distress is poor.
In this study, only 59.56% of patients with significant depression or anxiety indicated their need for psychological help. The result was similar to the results of a study from Seekles [2012] who found that just over half of patients had needs for mental health services (55.3%) (15). Prins et al. conducted a systematic review including 71 studies and found that only 49% to 84% of the patients with depression or anxiety perceived the need for treatment
Discussion of the patients’ emotional problems requires time, good communication skills and sufficient knowledge about emotional problems in patients. Most of the doctors did not have the skills or expertise to deal with these problems.
Moreover, medical staff may refer patients for psychiatric evaluation only when the problems become acute. McDonald et al. reported that when patients had obvious symptoms, such as crying and a depressed mood, the detection of psychological needs by staff was higher.
The concordance between doctors’ and patients’ perception of psychological needs was low (kappa =0.055). The concordance between patients and doctors on perceived needs for psychological services has not been broadly studied before. Therefore, it is difficult to compare our results with previous research. Richards conducted a study on patients with psoriasis and found that the level of concordance between patients’ and dermatologists’ rating for the presence of anxiety or depression was also low (kappa values of 0.24 and 0.26).
Logistic regression was used to find potential influencing factors of the concordance rate. However, only the wards in which the patients were treated at the time of the investigation could be identified as a reason for the discordance and this result might be not persuasive because of the low ratio (6.21%) of surgical patients. In the next study, the ward of the patient should be reasonably included and the number of surgical patients might be increased.
Conclusion
In this paper, we explored the concordance between Chinese patients’ perception of their own mental needs and the corresponding evaluation by doctors in charge of these inpatients. This concordance is believed to be an important factor to guarantee timely and adequate treatment. However, the concordance in this study was very low (kappa =0.055), even in patients with depression and anxiety, which is a severe problem on inpatients’ mental health. Therefore, in the future, we hope to shed some light on this topic by studying potential effective strategies to prompt this process, such as the raising of doctors’ awareness, the use of screening-instruments, and the training of health professionals.
Note: This work is partly presented at 3rd International Conference on Mental Health and Human Resilience on June 21-23, 2017 held in London, UK
Cheryl Staal
During the past two decades there has been a strong focus on suicide prevention, intervention and bereavement research. In Australia alone, over ten million dollars has been provided annually for suicide bereavement services. The impact of being exposed to suicide at work can be just as traumatizing as direct bereavement and have broad reaching, and sometimes lifelong implications. However, this issue and group have not been acknowledged, and there is a dearth of dedicated research or funded support. Suicide is commonly perceived as three slightly different concepts. Most common is a person taking their own life, whereas assisted suicide is when the person intentionally kills themselves with the assistance of another person who provides the knowledge or means to do so. Followed by euthanasia which in Australia is perceived as the deliberate, intentional act of one person to end the life of another person in order to relieve that persons suffering . According to Australia Bureau of Statistics there was an average daily rate of 8 suicide deaths during 2015 and 2016.
Though the Australian StandBy support after suicide service is not targeted to staff exposed to suicide at work, its client support data validates this bread of exposure in the most common relationship of clients to the deceased being 23% partners, parents or other relatives, 13% worked with the deceased and 4% service providers. Furthermore, it is commonly presumed police or ambulance officers are first to arrive at the scene of a suicide. However, this is often not so. According to StandBy support after suicide data 27% of its clients in 2016, who were not emergency service staff had discovered the deceased
As all senses are extremely heightened at the time of crisis, if the staff member experiences post-traumatic stress disorder a reoccurrence of those senses such as seeing blood or smelling the deceased’s cologne could trigger future reactions. Depending on the closeness of their relationship with the deceased this could also be associated with sudden temporary upsurges of grief – STUGS which exposed staff report are just as overwhelming as during the initial phase of grief
Furthermore, the exposed staff member may have been a close friend of the deceased, and be the critical incident coordinator or investigator. In this instance they not only experience the trauma of finding their deceased colleague, but also having to maintain their professionalism until the incident has been dealt with. By postponing their grief and obtaining support, it could exacerbate issues for them. Interestingly Pitman, Osborn and Rantell’s research found people directly bereaved by suicide are 80% more likely to drop out of work or education. One ponders what the dropout rate and ongoing implications are for those not only bereaved, but also directly exposed to suicide in other manners? When back at work the majority of those exposed also report they experiencing presenteeism. That is physically being there, but finding their mind wanders thinking about the deceased person or the scene they encountered. A poignant example is after the suicide of a fellow police officer, officers of various ranks commented “you’re expected to get on with things, even if we had been their best mate since the academy, 20 years ago, so we turned up for shift as usual but found it hard to keep our minds on the job
Managing this type of critical incident in a workplace entails a myriad of aspects coupled with immediate, short and long term actions which are beyond the scope of this paper. However the author can provide further information and professional development on this topic. 4 suicide are resilient after a period of adjustment and may even experience post-traumatic growth
Conclusion So from the above discussion it is evident that staff can be exposed to suicide at any work place. And there are some similarities between exposure related trauma and that of other precipitating traumatic events. Additionally the impact of exposure can be just as significant as bereavement depending on the type of exposure, the strength of the collegial relationship with the deceased and potential difficulty adjusting to the trauma or loss. With the breadth of exposure spanning various staff, across a team, a whole organization and its stakeholder. Further, there are also professional, organizational and environmental specific issues that should be considered. And the level of trauma experienced can be exacerbated through various interrelated issues such as not being death competent, role requirements when already traumatized, or a workplace culture resistant to help seeking. Therefore there is a significant need to acknowledge and research the impact of exposure to suicide at work.
Note: This work is partly presented at 3rd International Conference on Mental Health and Human Resilience on June 21-23, 2017 held in London, UK
Aristo Vojdani
Abstract
Objective: The aim of our study was to examine immunoreactivity between AβP-42, toxic chemicals, and food proteins thatwould be involved in AD. Methods: We applied monoclonal anti-AβP-42 to a range of chemicals bound to human albumin (HSA) and 208 different food extracts.
Keywords: AβP-42; Amyloidogenesis; Alzheimer’s Disease; Toxins; Dietary Proteins; Immunoreactivity; Neurodegeneration
Immunoreactivity to Common Foods: Now that we have some understanding of Immunology under our belts, we will get to the meat of what my clients tend to care about – immunoreactivities to common foods and how this may be a trigger for autoimmunity or one’s own immune system seeing self-tissue as a pathogen. This is a very big deal as it is estimated that over 50 million Americans suffer from some kind autoimmunity (comparatively, heart disease “only” affects upwards of 22 million Americans) and the occurrence of autoimmunity is growing exponentially. It is now believed that around 30% of autoimmunity is due to genetic predisposition. But, this implies that 70% of autoimmune cases are potentially caused by environmental and lifestyle triggers – the main culprits being intestinal permeability, infections, and chemical exposures.
“Bacterial toxins, chemicals, foods, and undigested proteins and peptides can induce systemic food immune reactivity by causing failure of immune tolerance. Immune tolerance is the immune system’s ability to recognize what is harmful and what is not. If immune tolerance is lost, then inflammation ensues and autoimmunity can occur.”
The digestive system sees over 1 ton of food every year and contains north of 70% of our immune cells. Your gastrointestinal tract also has more contact with the surface world than your skin and this mucosal lining is constantly being exposed to potential antigens.
The reason our body doesn’t wreck shop on all this food stuff all the time is due to oral tolerance which occurs through the deletion or immunosuppression of reactive immune cells.
Reacting to common food items isn’t normal and may be due to impaired immunological development (which is outside the scope of this post and revolves around the hygiene hypothesis, maternal diet, how one was born, breast feeding, and also the infant gut microbiota) or an immune system that’s out of balance (cough low vitamin D) and over stimulated (SAD).
The figure above is from Dr. Aristo Vojdani,, if not the leader, in food immunoreactivity. There is a lot going on above, but we can use our newfound understanding of immunology and begin to grasp how this all works.
Materials and Methods
Monoclonal antibodies:
Commercially available antibodies were purchased from different companies. Rabbit monoclonalanti-amyloid-β1-42(fibrilsequence DAEFRHDSGYEVHHQKLVFFAEDVGSNKGAIIGLMVGGVVIA) produced by Abcam’s RabMab® technology was purchased from Abcam. This antibody reacts strongly to human Aβ 42 monomers, oligomers and fibrils, but not with human muscle fibrils. Additional information about the specificity of this antibody is provided in the Abcam package insert (ab201061) and in an article by Hatami et al. [53]. Affinity-purified mouse anti-amyloid-β1-42 was purchased from BioLegend, San Diego, CA USA. This antibody reacted strongly with formalin-fixed, paraffin- embedded diseased human brain tissue.
Binding of phthalate to HAS:
Preparation of diethyl phthalate was done according to the method described by Zhou et al. [54]. Briefly, 2 mg of diethyl phthalate was dissolved in methanol and added dropwise to 25 mg of HSA dissolved in 5 mL of 0.14 Tris-HCl buffer.
Preparation of dietary antigens: Food antigens were prepared from products purchased from the supermarket in both raw and cooked forms. For that preparation, 10 g of nutrient was put in a food processor using 0.1 M of phosphate buffer saline (PBS) at pH 7.4. The mixer was turned on and off for 1 h and then kept on the stirrer overnight at 4°C. After centrifugation Citation: Vojdani A, Vojdani E (2018) Immunoreactivity of Anti-AβP-42 Specific Antibody with Toxic Chemicals and Food Antigens. J Alzheimers Dis Parkinsonism 8: 441. doi: 10.4172/2161-0460.1000441 Page 3 of 11 Volume 8 Issue 3 • 1000441 J Alzheimers Dis Parkinsonism, an open access journal ISSN:2161-0460 at 20,000 g for 15 min, the top layer, which contained oil bodies, was discarded The liquid phase was removed and dialyzed against b0.01 M of PBS using dialysis bags, with a cutoff of 6,000 kDa. Dialysis was repeated three times to ensure all small molecules were removed. After dialysis, all samples were filtered through a 0.2 micron filter to remove any debris. Protein concentrations were measured using a kit provided by Bio-Rad (Hercules, CA, USA). Different peptides were purchased from Bio-Synthesis (Lewisville, TX, USA). Lectin and agglutinins including pea lectin and lentil lectin were purchased from SigmaAldrich (St. Louis, MO, USA).
Conclusion:
Depend on these results, we hypothesized that reaction between AβP-42 antibody with chemically bound to HSA and numerous food antigens might play a lead role in Alzheimer’s disease (AD). These anti-AβP antibodies might be derived from protein mis folding like to β-amyloid, or from antibodies to various food antigens that cross-react with AβP-42. Removal of toxic chemicals and food items that share a homology with β-amyloid is also recommended at least for patients within the early stages of AD. Therefore, the role of AβP-42 cross-reactive foods and chemicals bound to HSA in neurodegeneration should be investigated further.
Results: We have found that anti-AβP-42 reacts from moderately to strongly with mercury-HSA, dinitrophenyl-HSA (DNP-HSA), phthalate-HSA, and aluminum-HSA, but not to many other tested chemicals bound to HSA nor to HSA alone. This antibody also reacted with 19 out of the 208 food antigens utilized in the assay. One example of a food that reacted strongly with anti-AβP-42 in our study was canned tuna, although raw tuna reacted only moderately.
Bottom line: This work is partly presented at 11th International Conference on Alzheimers Disease & Dementia, May 24-25, 2018 | Vienna | Austria
Danielle Meola
Abstract: Brain-derived interleukin-2 (IL-2) has been implicated in diseases processes that arise during CNS development (e.g., autism) to neurodegenerative alterations involving neuroinflammation (e.g., Alzheimer’s disease). Progress has been limited, however, because the vast majority of current knowledge of IL-2’s actions on brain function and behavior is based on the use exogenously administered IL-2 to make inferences about the function of the endogenous cytokine. Thus, to Spot the cell-type(s) and regional circuitry that express brain-derived IL-2, we used B6.Cg-Tg/ IL2-EGFP17Evr (IL2p8-GFP) transgenic mice, which express green fluorescent protein (GFP) in peripheral immune cells known to produce IL-2. We found that the IL2-GFP transgene was localized almost exclusively to NeuN-positive cells, indicating that the IL-2 is produced primarily by neurons. The IL2-GFP transgene was expressed in discrete nuclei throughout the rostral-caudal extent of the brain and brainstem, with the best levels found in the cingulate, dorsal endopiriform nucleus, lateral septum, nucleus of the solitary tract, magnocellular/gigantocellular reticular formation, red nucleus, entorhinal cortex, mammilary bodies, cerebellar fastigial nucleus, and posterior interposed nucleus. Having identified IL-2 gene expression in brain regions related to the regulation of sensorimotor gating (e.g., lateral septum, dorsal endopiriform nucleus, entorhinal cortex, striatum), we compared prepulse inhibition (PPI) of the acoustic startle reaction in congenic mice bred in our lab that have selective loss of the IL-2 gene in the brain versus the peripheral immune system, to test the hypothesis that brain-derived IL-2 plays a role in modulating PPI. We found that congenic mice void of IL-2 gene expression in both the brain and the peripheral immune system, exhibited a modest alteration of PPI. These finding suggest that IL2p8-GFP transgenic mice is also a a useful tool to elucidate further the role of brain-derived IL-2 in normal CNS function and disease.
Keywords: Interleukin-2, Congenic mice, Sensorimotor gating, Prepulse inhibition
Introduction:
Research has implicated both peripheral immune and brain-derived interleukin-2 (IL-2) in neurologic disease processes that arise during CNS development (e.g., autism) to neurodegenerative alterations involving neuroinflammation (e.g., Alzheimer’s disease). It is widely appreciated, as an example, that exogenously administered IL-2 has neuromodulatory actions starting from neurotrophic effects on septohippocampal neurons in culture and neurotransmitter release from cholinergic neurons, to hippocampal long-term potentiation and age-related changes in learning and memory. The vast majority of our knowledge of IL-2’s actions on brain function and behavior, however, is based on studies that use exogenously administered IL-2 to make inferences about the function of the endogenous cytokine.
Materials and Methods:
Animals and congenic breeding:
All mice in this study were cared for in compliance with the NIH Guide for the Care and Use of Laboratory Animals. Mice were housed in microisolater cages under specific pathogen free conditions. For GFP expression studies of the IL-2 transgene, female B6.Cg-Tg (IL2-EGFP) 17Evr (IL2p8-GFP) mice were obtained from the Mutant Mouse Regional Resource Center (University of Missouri) and bred in colony with C57BL/6 mice originally obtained from Jackson Laboratories. Transgene positive offspring were identified by PCR analysis of tail DNA. PCR primers in the IL-2 proximal promoter (IL2-1F: 5′-CATCCTTAGATGCAACCCTTCC-3′) and the GFP coding sequence (GFP-1R: 5′-GCTGAACTTGTGGCCGTTTAC-3′) were used, amplifying a 830-bp product in transgene-positive mice. PCR conditions were as follows: 95°C, 5 min, then 32 cycles of 95°C, 30 s; 58°C, 30 s; 72°C, 45 s, followed by a final 5 min at 72°C, using an i cycler (BioRad).
Tissue preparation: Mice were anesthetized by intraperitoneal injection of a 0.5 mg/mL ketamine cocktail in a 3:3:1 ratio (ketamine/xylazine/acepromazine) and were perfused with 4% paraformaldehyde (PF). Brains were dissected, post-fixed in 4% PF for 2 hrs at room temperature, and cryoprotected in 30% sucrose overnight at 4°C. Tissue was snap frozen in isopentane and stored at −80°C.
Acoustic startle reactivity and prepulse inhibition (PPI):
Two SR-LAB test chambers (San Diego Instruments) were used to measure acoustic startle response and prepulse inhibition as described previously. Mice were placed in a small cylindrical enclosure (3.8×9.5 cm) located in a dark, ventilated chamber. A speaker located 30 cm above the cylinder delivered the background noise (65 dB), startle stimuli, and prepulse stimuli, all of which consisted of broadband white noise.
Statistical analysis: Analysis of variance (ANOVA), and repeated measures ANOVA were used to make comparisions between subject groups. Post-hoc comparisons of interest were performed using the Fisher’s least significant difference test.
Results: We first tested the specificity of the GFP antibody by preincubating the primary antibody with recombinant GFP prior to use in our staining protocol to quench its ability to bind the antigen in tissue. As seen in Figure 1, as expected, immune cells (e.g., T cells, dendritic cells) in the white pulp area of the spleen expressed GFP, and the specificity of the primary antibody was clearly demonstrated by pre-incubation with recombinant GFP. As can be seen in Figure 2, a representative photograph of the septum and red nucleus, in most cells expressing GFP in the brain, the reporter was co-localized to the pan-neuronal cell marker, NeuN. Figure 3 shows GFP-positive cells identified in the medial and lateral septum, the fastigial nucleus, and the interposed nucleus of the cerebellum. In all areas examined, there were only a few cells that stained positive for GFP but not NeuN. Those brain cells were morphologically and geographically identical to brain cells expressing both markers. Across brain regions, we were ready to determine relative expression of IL-2 in IL2p8-GFP transgenic mice. GFP expression was found throughout the rostral-caudal extent of the brain and brainstem of IL2p8-GFP transgenic mice in discrete nuclei, and with a wide range of staining intensity.
Note: This work is partly presented at 5th Global Experts Meeting on Parkinsons, Huntingtons and Movement Disorders Oct 30-31, 2019 Tokyo, Japan
Fabiano Henrique Rodrigues Soares
Abstract:
The aim of this study was to verify measures of Pulse rate / heart rate variability in patients with idiopathic Parkinson’s disease. Seventy two male participants volunteered for the study, 36 with diagnosed Parkinson’s disease and 36 asymptomatic individuals. We conducted ambulatory recordings of 10 minutes in orthostatic position after five minutes of rest. Data was collected with POLAR RS800CX cardiac monitor and then analyzed by Kubios HRV 2.0 software to get measures of time and frequency domains. We found reductions in most a part of collected indexes without correlation with disease duration or drugs dosage. The reductions of collected indexes reinforce the concept that Parkinson’s disease alters the autonomic nervous system modulation.
Keywords:
Parkinson’s disease; Pulse rate; Autonomic nervous system
Abbreviations:
NN: NN Interval (Inter-Beat Interval); RMSSD: Root Mean Square of Differences between NN Intervals; SDNN: Standard Deviation of NN Intervals; PNN50: Percentage of NN Intervals Greater than 50 ms (Milliseconds); FFT: Fast Fourier Transform; LF: Low Frequency; HF: High Frequency; LF/HF: LF An HF Ratio; ECG: Electrocardiogram; HRV: Heart Rate Variability.
Introduction:
Parkinson’s disease is a neurodegenerative morbidity that leads to motor, psychiatric and sleep disorders. In terms of motor symptoms, postural instability, shaking, rigidity, and slowness of movements are the most common symptoms. There is loss of dopamine production in midbrain neurons, resulting in loss of dopaminergic innervations in the striatum. In addition to an extra pyramidal motor dysfunction, patients frequently show Autonomic Nervous System (ANS) disorders, even in early phases of the disease.
This disease can promote autonomic dysfunction by damage in hypothalamus, basal ganglia, formatio reticularis, cerulean and nerve vagus dorsal nuclei. Besides those pre-ganglia structures, post-ganglia sympathetic neurons and other ANS structures are also affected.
There are assumptions that the neurodegenerative characteristics of the disease is also associated with indexes of Pulse Rate Variability (HRV). Changes in ANS in Parkinson’s patients include perturbations in cardiovascular regulation, hypotension, especially in orthostatic position, and sexual dysfunction.
HRV indexes in time and cardiac frequency domains have proven useful measures in predicting cardiac arrhythmias, mortality risk by cardiac artery disease and various central nervous system disturbs, such as stroke, epilepsy, brain damages and other degenerative brain disorder.
Recently, authors evaluated the cardiovascular autonomic regulation in patients in several disease stages using short duration measures and reinforced the strategy efficacy as non-invasive strategy. Thus, the aim of this study was to verify measures of HRV in patients with idiopathic Parkinson’s disease.
Materials and Methods:
Seventy-two volunteer male participants were randomly selected in a university clinical center (UNP/Brazil). The sample included 36 patients with diagnosed Parkinson’s disease (Parkinson Group PG) and 36 healthy individuals (Control Group=CG). We conducted measures of HRV using ambulatory recordings with 10 minutes of duration in orthostatic position, after a 5-minute rest period. The CG didn’t have any kind of neurologic or cardiac disorder. In addition, they didn’t use any quite medication and had no genetic relation with the patients.
Results and Discussion:
Participant’s anthropometric and clinical characteristics. There was no evidence of peripheral or autonomic neuropathy, including postural hypotension. Rest heart rate, Systolic Blood Pressure (SBP) or Diastolic Blood Pressure (DBP) did not differ between groups. Body weight was significantly different between groups but we have no reason to believe that it interfered with the dependent variables.
The time domain of HRV in patients revealed accentuated reductions in RMSSD, SDNN, NN, pNN50 in comparison with CG in accordance with the literature .The frequency domain revealed consistent reductions in LF, HF and LF/HF in PG, in contrast with elevations on the same indexes in the CG. There was no correlation between age and time or frequency domains in any group.
Parkinson’s is a slow-progression disease and is, in general, related with shaking, rigidity in body members, as long as rigidity in muscles and slowness of movements. Some evidences suggest that a combination between genetic and environmental factors may be placed as causes of those symptoms.
In addition, the deregulation of cardiovascular control may be related with the peripheral or central physiopathology of the Parkinson’s disease . Our findings support this hypothesis, once there were significant differences in HRV indexes between groups, denoting dysfunctions in the balance between sympathetic and parasympathetic control in cardiac activity.
Earlier studies with Parkinson’s patients, using tests in cardiovascular reflexes, have demonstrated repressed responses of cardiac frequency for various stimuli, like normal and deep breathing and Valsalva maneuver. Those findings describe autonomic responses, during only a limited period of time, with large individual variability, promoting a limited view of the autonomic mechanisms in control of cardiac activity
.
Conclusions:
Reductions in HRV indexes, associated with the disease, reflect loss of sympathetic and parasympathetic balance, which may be result of structural damage caused by Parkinson’s disease. HRV, as non-invasive technique, might represent a strong indicator of neuronal regulatory activity. Its use can represent a useful tool, not only for research, but also for early diagnosis and clinical behavior of Parkinson’s disease.
Note: This work is partly presented at 5th Global Experts Meeting on Parkinsons, Huntingtons & Movement Disorders , Oct 30-31, 2019 Tokyo, Japan
Onder Albayram
Overview of Prions and Neurodegenerative Disease:
The accumulation of protein aggregates is a common feature of many neurodegenerative diseases including Alzheimer’s disease (AD), Parkinson’s disease (PD) and frontotemporal dementia (FTD), Each type of aggregate has one type of protein as its major component, with amyloid-β, hyperphosphorylated tau and α-synuclein being the most commonly observed. These proteins undergo a transformation from a soluble monomer to an insoluble, aggregated state through a number of intermediates . Researchers have speculated that the protein deposits found in these neurodegenerative diseases may develop and spread throughout the brain in a very manner analogous to it of aggregation of the prion protein (PrP) in transmissible spongiform encephalopathies (TSEs), such as Creutzfeldt-Jakob disease (CJD). Many recent studies in rodents, as well as in humans , support the notion that AD pathology propagates in a prion-like fashion. Elowever, there is no evidence suggesting that non-TSE neurodegenerative diseases, including AD, can be transferred between individuals in any case other than direct injection of diseased brain extracts, hence the use of “prion-like.”
Structure and Toxicity of Pathological Tau:
Native tau contains a relatively loose, unstructured protein with little α-helix and β-sheet structure. In the adult human brain, tau protein appears as six isoforms, all derived from a single gene by alternative splicing. Three of these isoforms contain three repeats (3R-τ) of a sequence thought to be involved in binding to microtubules; the other three isoforms contain an additional fourth repeat of the region, coded by exon 10 (4R-τ). The repeat region of tau is positioned between two basic, proline rich regions. Many of these prolines are preceded by a serine or threonine, allowing for phosphorylation. Dimerization due to disulfide cross-linking has been proposed to be a first step in the formation of NFTs, and only occurs when lysines in the microtubule binding repeat regions are phosphorylated . This in turn disrupts tau’s function on microtubules and alters its protein stability, eventually leading to aggregation and tangle formation.
Neurofibrillary tangles are a neuropathological hallmark of tauopathies AD and other tauopathies and were previously believed to be the toxic species. However, recent studies have demonstrated that necrobosis occurs before tangle formation, meaning some earlier intermediate must be the source of tau toxicity. The culmination of many years of increasing research into the toxicity of tau aggregation in neurodegenerative disease has led to the proposal that soluble, oligomeric kinds of hyperphosphorylated tau (p-tau) are likely the most toxic entities in disease. These p-tau oligomers are able to enter and exit cells in vitro, and are believed to be a serious species accountable for propagation, although the exact mechanism is continues to be unknown. Evidence suggests that these multimeric tau oligomers may act as templates for the misfolding of native tau, thereby seeding the spread of the toxic kind of the protein and initiating disease progression in a manner analogous to that of prions . Additionally, these oligomers have repeatedly been found to induce necrobiosis in numerous tauopathies and can propagate through the brain causing synaptic and mitochondrial dysfunction associated with memory deficits .
Upon phosphorylation of tau on the Thr231-Pro motif, Pin1 converts cis to trans of p-tau at a much higher frequency, although it can catalyze both directions. When Pin1 becomes down-regulated or when cis p-tau is produced in abnormally high quantities, as we see in the case in TBI and AD, the cis conformation begins to accumulate in the brain. Unlike trans p-tau, which may bind and promote microtubule assembly, is liable to protein dephosphorylation and degradation and immune to protein aggregation, and does not cause neurodegeneration, cis p-tau cannot bind and promote microtubule assembly, is immune to protein dephosphorylation and degradation, prone to protein aggregation, and cause and spread neurodegeneration.
Alzheimer’s Disease
The work from our lab and others has uncovered the extensive contribution ofPin1 to the development of AD pathology. Pin1 promoter polymorphisms resulting in decreased Pin1 levels are associated with an increased risk for late-onset AD . In contrast, Pin1 SNPs resulting in reduced Pin1 inhibition are related to with a delayed onset of AD . In a normal human brain, Pin1 expression was relatively low in regions of the hippocampus that are susceptible to NFT-related neurodegeneration in AD (CA1 and subiculum), while Pin1 expression was higher in regions that are generally spared (CA4, CA3, CA2, presubiculum) .In the brains of human AD patients, the majority of pyramidal neurons (96%) with relatively high Pin1 expression lacked tau tangles, and most pyramidal neurons (71%) with relatively low Pin1 expression had tangles . Furthermore, Pin1 co-localizes and co-purifies with NFTs, and can directly restore the ability of tau to bind microtubules and promote microtubule activity . Finally, levels of p-Thr231 tau correlate with the progression of AD, and Pin1 is strongly correlated with dephosphorylation of tau at Thr231
Healthy tau contains a high affinity for microtubules, promoting their assembly and assisting in the transportation of various proteins and nutrients along the axon. (B) Cis p-tau loses this affinity and dissociates from the microtubule. (C) The tau which dissociates from the microtubule also develops a much better affinity for itself and begins to aggregate, and really seeds itself in a manner like to the prion protein. This essentially means toxic tau can convert other healthy tau in the brain into the toxic cis conformation, causing a systematic and predictable spread of tau pathology. This cis P-tau is also the missing step in the process of neurodegeneration. (D) The isomerization causes healthy, physiological trans tau to become a toxic cis form, which is capable of causing and spread neurodegeneration and eventual tau tangles in tauopathies. (E) The flexibility of cis p-tau to cause and spread neurodegeneration is effectively neutralized by cis p-tau antibody, which targets intracellular cis P-tau for proteasome-mediated degradation and preventing extracellular cis P-tau from spreading to other neurons.
Traumatic Brain Injury and Chronic Traumatic Encephalopathy:
Traumatic brain injury (TBI) and chronic traumatic encephalopathy (CTE) are closely related tauopathies that have significant potential for studying the toxicity and spread of tau in controlled conditions. Repetitive mild TBI (rmTBI), or single moderate/severe TBI (ssTBI), may cause acute and potentially long-lasting neurological dysfunction, including the development of CTE. Additionally, TBI is an established environmental risk factor for AD
Therapy
Studies have revealed the potential of antibody treatments in neutralizing toxic cis p-tau, thereby halting, or or a minimum of significantly delaying, neurodegeneration. This therapy has so far proved successful in mouse models of TBI. Periodic treatment with a cis p-tau monoclonal antibody treatment over 4 months not only eliminated spreading of cis p-tau, axonal pathology and astrogliosis into the hippocampus without affecting physiologic trails p-tau, but also prevented tau oligomerization, tangle formation, and APP accumulation.Shorter courses of treatment (between 5 and 10 days) with delayed administration also proved effective at eliminating cis p-tau induction.A humanized version of the cis p-tau antibody could prove extremely useful in treating the wide range of neurodegenerative diseases associated with toxic tau.
Conclusion:
For many years NFTs were the most subject of study in research done on tau toxicity in neurodegenerative diseases. Recently evidence has pointed to an intermediate in the aggregation process, like soluble cis p-tau, as a more likely candidate for the toxic species in common tauopathies. As more research has been done on tau aggregation intermediates, the prion-like nature of tau has been made apparent.
Note: This work is partly presented at International Conference on Psychology, Autism and Alzheimers Disease September 30 - October 01, 2013 San Antonio, USA
Takashi Mori
Abstract: Few studies have investigated physiologic and cognitive effects of “long-term" electromagnetic field (EMF) exposure in humans or animals. Our recent studies have provided initial insight into the long-term impact of adulthood EMF exposure (GSM, pulsed/modulated, 918 MHz, 0.25–1.05 W/kg) by showing 6+ months of daily EMF treatment protects against or reverses cognitive impairment in Alzheimer's transgenic (Tg) mice, while even having cognitive benefit to normal mice. Mechanistically, EMF-induced cognitive benefits involve suppression of brain β-amyloid (Aβ) aggregation/deposition in Tg mice and brain mitochondrial enhancement in both Tg and normal mice. The present study extends this work by showing that daily EMF treatment given to very old (21–27 month) Tg mice over a 2-month period reverses their very advanced brain Aβ aggregation/deposition. These very old Tg mice and their normal littermates together showed an increase generally memory function in the Y-maze task, although not in additional complex tasks. Measurement of both body and brain temperature at intervals during the 2-month EMF treatment, also a separate group of Tg mice during a 12-day treatment period, revealed no appreciable increases in brain temperature (and no/slight increases in body temperature) during EMF “ON" periods. Thus, the neuropathologic/cognitive benefits of EMF treatment occur without brain hyperthermia. Finally, regional cerebral blood flow in cortex determined to be reduced in both Tg and normal mice after 2 months of EMF treatment, most likely through cerebrovascular constriction induced by freed/disaggregated Aβ (Tg mice) and slight body hyperthermia during “ON" periods. These results demonstrate that long-term EMF treatment can provide general cognitive benefit to very old Alzheimer's Tg mice and normal mice, similarly reversal of advanced Aβ neuropathology in Tg mice without brain heating. Results further underscore the potential for EMF treatment against AD.
Results:
Behavioral assessment during long-term EMF treatment:
In Study I, behavioral testing of aged Tg and NT mice between 1 and 2 months into daily EMF treatment indicated no deleterious effects of EMF treatment on sensorimotor function (Table 1). For both Tg and NT mice, general activity/exploratory behavior was unaffected by EMF treatment, as indexed by open field activity and Y-maze choices made. As well, balance and agility abilities weren’t impacted in either Tg or NT mice by EMF treatment, as indexed by balance beam and string agility performance. In both of these tasks, however, an overall effect of genotype was presence, with Tg mice having poorer balance/agility compared to NT mice irrespective of EMF treatment (p<0.002). Finally, visual acuity testing in the visual cliff task at the end of behavioral testing (2 months into EMF treatment) indicated no deleterious effects of EMF treatment on vision in either Tg or NT mice.
Study I.
Body and brain temperature measurements were attained from aged animals in Study I before start of EMF treatment (control) and at 1, 3, and 6 weeks into treatment (final temperature measurements were unfortunately not taken at the 2-month termination point of this study). Throughout the 6-week study period, body and brain temperature recordings indicated very stable temperature in control NT and control APPsw (Tg) mice not being given EMF treatment .By contrast, body temperature for both EMF-treated NT and Tg mice was modestly elevated by 0.5–0.9°C during ON periods compared to OFF periods, from 1 week into EMF treatment onward through treatment. For Tg mice, this increase in body temperature during ON periods was evident even on the first day of EMF treatment. During EMF OFF periods for both NT and Tg mice, body temperature always came back down to their pre-treatment levels. Since body temperature before start of EMF treatment was identical for Tg mice (but not NT mice) to be given EMF or sham treatment, temperature comparisons between these two groups throughout the EMF treatment period also revealed that the elevated body temperatures of Tg mice during ON periods always came back down to sham control levels during OFF periods.
Discussion:
We have previously reported that long-term (>6 months) EMF exposure at cell phone level frequencies and SAR levels can protect against or reverse cognitive impairment in Alzheimer's Tg mice, while even having cognitive benefit to normal mice. Moreover, we previously provided the first mechanistic insight into long-term EMF treatment by reporting the ability of such treatment to suppress brain Aβ aggregation/deposition in AD mice, while enhancing brain mitochondrial function and neuronal activity in both Tg and normal mice .The present study extends the above works by administering long-term (2 months) of daily EMF treatment to very old Alzheimer's Tg mice and showing that such treatment can reverse their very advanced brain Aβ aggregation/deposition while providing selected cognitive benefit to both Tg and normal mice. Moreover, these neuropathologic and cognitive benefits occurred without appreciable increases in brain temperature, indicating involvement of non-thermal brain mechanisms (i.e., Aβ anti-aggregation, mitochondrial enhancement, neuronal activity). Finally, the present study is the first to determine the effects of long-term EMF exposure on rCBF, and in the same animals evaluated for cognitive, neuropathologic, and body/brain temperature endpoints. Our finding of an EMF-induced decrease in cortical blood flow raises several interesting mechanisms of action that merit consideration.
Statistical Analysis:
Data analysis of physiologic and neurohistologic measurements, as well as all one-day behavioral measures, were performed using ANOVA followed by Fisher's LSD post hoc test. For the multiple-day behavioral tasks (RAWM and circular platform), initial ANOVA analysis of 2-day blocks and overall were followed by analysis of post hoc pair-by-pair differences between groups via the Fisher LSD test. For temperature and blood flow measurements within the same animal, paired t-tests were employed. All data are presented as mean ± SEM, with significant group differences being designated by p<0.05 or higher level of significance.
Note: This work is partly presented at 5th Global Experts Meeting on Parkinsons, Huntingtons & Movement Disorders Oct 30-31, 2019 Tokyo, Japan.
Ubaldo Armato
Abbreviations: Aβ: Amyloid β peptide; Ach: Acetylcholine; AD: Alzheimer’s Disease; BDNF: Brain-Derived Neurotrophic Factor; BFCSNs: Basal Forebrain Cholinergic Septal Neurons; DGy: Dentate Gyrus; GN: Granule Neuron; LTP: Long-Term Potentiation; NGF: Nerve Growth Factor; NT-3: Neuro-Trophin-3; p75NTR: p75 NeuroTrophin Receptor; SGZ: Sub-Granular Zone; SST: Somatostatin; SSTR3: SST Receptor 3; SVZ: Sub-Ventricular Zone; TA Transit-Amplifying; tPA: tissue Plasminogen Activator.
The key role of p75NTR in the generation of DGy GNs. In this cheme, a neuro-trophin (BDNF or NGF) in the DGy SGZ activates cilial p75NTR, the signals from which stimulate progenitor cell proliferation and the generation of rapidly proliferating TA precursor neurons. After several rounds of proliferation, the TA precursor neurons stop proliferating and signals 6 from the cilial SSTR3 and BDNF•TrkB complexes stimulate them to mature, enter the granule cell layer and serve transiently as intensive long-term potentiation (LTP)- generating, super-sensitive encoders of novel multi-modal inputs flowing along the perforant pathway from the entorhinal cortex. Normally, half or more of the newborn cells may die without reaching the granule cell layer. But NGF produced in the DGy from proNGF by tPA-generated plasmin forms NGF•Trk A complexes that stimulate BFCSNs to make Ach and release it in the hippocampus, which promotes newborn neurons survival and thus neurogenesis and memory formation. Eventually, the successful neurons lose their hyper-responsiveness and become loaded with old ‘memories’, retire, and are replaced with new recorders.
The Aβ peptides accumulating in the early stages of AD also stimulate cilial p75NTR like the neuro-trophins and with this the proliferation of granule cell progenitors and their TA progeny. But the additional neurogenesis expected from this stimulation fails and neurogenesis drops because proNGF can no longer be converted into mature NGF because of a developing shortage of plasmin resulting from an Aβ1-42-induced fall in tPA. But proNGF preferentially binds and activates the p75NTR•sortilin complexes instead of NGF•TrkA complexes on the BFCSN axons. The retrograde flow of p75NTR•sortilin signals down the axons kills the BFCSNs and stops the hippocampal supply of ACh that would otherwise promote the survival of the TA precursor neurons. Furthermore, TA neurons that do survive are prevented from further maturing by the lack of SST?a hallmark of the AD brain?and the consequent silencing of SSTR3 signaling.
More than 90% of the murine DGy GNs have a ~4-µm-long cilium protruding from them. These cilia are loaded with p75NTR, the signals from which can stimulate granule cell progenitor proliferation, and also with SSTR3 (not shown), the signals from which can drive the postmitotic maturation of newborn neurons.
So what might the cilially restricted p75NTR do for adult neurogenesis? Key clues to its function are: (i) proliferating (i.e., BRDU-positive) cells in the DGy SGZ express p75NTR; and (ii) knocking out p75NTR reduces the proliferating cells and hippocampal neurogenesis by 59%-79% [12,13]. Although we do not yet know whether the progenitor cells in the other adult neurogenesis region, the SVZ [1], also confine p75NTR to their primary cilia, BDNF-, NGF- or Aβ 1-42-induced p75NTR signaling stimulates their proliferation and neurogenesis without requiring BDNF's or NGF's corresponding TrkB or TrkA co-receptors. Therefore, cilial p75NTR is a driver of the proliferative stage of adult neurogenesis.
The ability of the proliferogenic cilial p75NTR to bind and be activated by Aβ 1-42 can explain a so far mysterious aspect of adult neurogenesis in early AD. Progenitor cell proliferation and adult neurogenesis normally decline with age, and it would be expected to at least continue dropping with the approach of AD. But the ability of Aβ 1-42 to activate the proliferogenic p75NTR reverses this trend and progenitor cell proliferation counter-intuitively increases in the early Aβ 1-42-accumulating stages of AD. While this is happening, the pro-NGF-activated axonal p75NTR.sortilin complexes induced by the accumulating Aβ 1-42 start killing BFCSNs and cutting off the hippocampal supply of ACh. Also counter-intuitively despite the increased Aβ 1-42/p75NTR-driven progenitor cell proliferation, neurogenesis is not increased because fewer TA neurons can survive without the support of ACh and because the cilial SSTR3 receptors needed for maturation and memory functions are silenced by the lack of SST in AD brains.
In conclusion: Cilial p75NTR must now be part of models of adult neurogenesis in the DGy and memory formation and of the cognitive decline in aging and AD brains.
Note: This work is partly presented at 5th Global Experts Meeting on Parkinsons, Huntingtons & Movement Disorders, Oct 30-31, 2019 Tokyo, Japan
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