Telmisartan Reduces Progressive Oxidative Stress and Phosphorylated α-Synuclein Accumulation in Stroke-resistant Spontaneously Hypertensive Rats after Transient Middle Cerebral Artery Occlusion

Reproductive toxicity and molecular responses induced by telmisartan in Daphnia magna at environmentally relevant concentrations

With aging population increasing globally, the use of pharmaceutically active compounds is rising. The cardiovascular drug telmisartan has been widely detected in various environmental compartments, including biota, surface waters, and sewage treatment plant effluents at concentrations ranging from ng/L to μg/L levels. This study evaluated the effects of telmisartan on the microcrustacean Daphnia magna at a wide range of concentrations (0.35, 0.70, 1.40, 500, and 1000 μg/L) and revealed significant ecotoxicological implications of this drug, even at environmentally relevant concentration. Acute exposure to telmisartan (1.40, 500, and 1000 μg/L) resulted in a notable decrease in heart rate, while chronic exposure accelerated the time to the first brood by 3 days and reduced neonate body size. Molecular investigations revealed marked downregulation of vitellogenin genes (Vtg1 and Vtg2). Non-monotonic dose responses were observed for gene expression, early-stage body length, and the total number of offspring produced, while the heart rate and time to the first brood showed clear concentration-dependent responses. These findings highlight the potential risks, notably to reproductive capacity, associated with exposure to telmisartan in environmentally relevant concentration, suggesting the need for further studies on the potential long-term ecological consequences.

The contribution of β-amyloid, Tau and α-synuclein to blood-brain barrier damage in neurodegenerative disorders

Central nervous system (CNS) accumulation of fibrillary deposits made of Amyloid β (Aβ), hyperphosphorylated Tau or α-synuclein (α-syn), present either alone or in the form of mixed pathology, characterizes the most common neurodegenerative diseases (NDDs) as well as the aging brain. Compelling evidence supports that acute neurological disorders, such as traumatic brain injury (TBI) and stroke, are also accompanied by increased deposition of toxic Aβ, Tau and α-syn species. While the contribution of these pathological proteins to neurodegeneration has been experimentally ascertained, the cellular and molecular mechanisms driving Aβ, Tau and α-syn-related brain damage remain to be fully clarified. In the last few years, studies have shown that Aβ, Tau and α-syn may contribute to neurodegeneration also by inducing and/or promoting blood-brain barrier (BBB) disruption. These pathological proteins can affect BBB integrity either directly by affecting key BBB components such as pericytes and endothelial cells (ECs) or indirectly, by promoting brain macrophages activation and dysfunction. Here, we summarize and critically discuss key findings showing how Aβ, Tau and α-syn can contribute to BBB damage in most common NDDs, TBI and stroke. We also highlight the need for a deeper characterization of the role of these pathological proteins in the activation and dysfunction of brain macrophages, pericytes and ECs to improve diagnosis and treatment of acute and chronic neurological disorders.

A Review on Neuroinflammatory Pathway Mediating Through Ang-II/AT1 Receptors and a Novel Approach for the Treatment of Cerebral Ischemia in Combination with ARB's and Ceftriaxone

Background

Ischemic stroke is one of the prevalent neurodegenerative disorders; it is generally characterized by sudden abruption of blood flow due to thromboembolism and vascular abnormalities, eventually impairing the supply of oxygen and nutrients to the brain for its metabolic needs. Oxygen-glucose deprived conditions provoke the release of excessive glutamate, which causes excitotoxicity.

Summary

Recent studies suggest that circulatory angiotensin-II (Ang-II) has an imperative role in initiating detrimental events through binding central angiotensin 1 (AT1) receptors. Insufficient energy metabolites and essential ions often lead to oxidative stress during ischemic reperfusion, which leads to the release of proinflammatory mediators such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and cytokines like interleukin-18 (IL-18) and interleukin- 1beta (IL-1β). The transmembrane glutamate transporters, excitatory amino acid transporter-2 (EAAT-2), which express in astroglial cells, have a crucial role in the clearance of glutamate from its releasing site and convert glutamate into glutamine in normal circumstances of brain physiology.

Key Message

During cerebral ischemia, an impairment or dysfunction of EAAT-2 attributes the risk of delayed neuronal cell death. Earlier studies evidencing that angiotensin receptor blockers (ARB) attenuate neuroinflammation by inhibiting the Ang-II/AT1 receptor-mediated inflammatory pathway and that ceftriaxone ameliorates the excitotoxicity-induced neuronal deterioration by enhancing the transcription and expression of EAAT-2 via the nuclear transcriptional factor kappa-B (NF-kB) signaling pathway. The present review will briefly discuss the mechanisms involved in Ang-II/AT1-mediated neuroinflammation, ceftriaxone-induced EAAT-2 expression, and the repurposing hypothesis of the novel combination of ARBs and ceftriaxone for the treatment of cerebral ischemia.

Protective effect of novel angiotensin receptor neprilysin inhibitor S086 on target organ injury in spontaneously hypertensive rats

BACKGROUND

Hypertension is a clinical syndrome characterized by elevated systemic arterial blood pressure associated with injury to the heart, kidney, brain, and other organs. Angiotensin receptor neprilysin inhibitors (ARNi), including angiotensin receptor blockers (ARBs) and neprilysin inhibitors (NEPi), have been shown to be safe and effective at reducing blood pressure and alleviating development of target organ injury. This study was used to develop S086 as a novel ARNi and conducted preclinical studies in animal models to evaluate the protective effects of S086 on target organs.

METHODS

This study used a 14-month-old spontaneously hypertensive rat (SHR) model to evaluate the protective effects of S086 on the cardiovascular system and organs such as heart and kidney by blood pressure monitoring, urine and blood examination, pathological examination, and immunological index detection.

RESULTS

After administering S086 orally to the SHR, their blood pressure and levels of renal injury indicators such as serum creatinine and urinary microalbumin were reduced, and myocardial cell necrosis and cardiac fibrosis of the heart were significantly improved. In addition, there were also significantly improvements in the histological lesions of blood vessels and the kidneys.

CONCLUSIONS

The findings showed that S086 effectively reduced the blood pressure of SHR and had effects on alleviating development of heart, blood vessels and kidney.

Alpha synuclein post translational modifications: potential targets for Parkinson's disease therapy?

Parkinson's disease (PD) is the most common neurodegenerative disorder with motor symptoms. The neuropathological alterations characterizing the brain of patients with PD include the loss of dopaminergic neurons of the nigrostriatal system and the presence of Lewy bodies (LB), intraneuronal inclusions that are mainly composed of alpha-synuclein (α-Syn) fibrils. The accumulation of α-Syn in insoluble aggregates is a main neuropathological feature in PD and in other neurodegenerative diseases, including LB dementia (LBD) and multiple system atrophy (MSA), which are therefore defined as synucleinopathies. Compelling evidence supports that α-Syn post translational modifications (PTMs) such as phosphorylation, nitration, acetylation, O-GlcNAcylation, glycation, SUMOylation, ubiquitination and C-terminal cleavage, play important roles in the modulation α-Syn aggregation, solubility, turnover and membrane binding. In particular, PTMs can impact on α-Syn conformational state, thus supporting that their modulation can in turn affect α-Syn aggregation and its ability to seed further soluble α-Syn fibrillation. This review focuses on the importance of α-Syn PTMs in PD pathophysiology but also aims at highlighting their general relevance as possible biomarkers and, more importantly, as innovative therapeutic targets for synucleinopathies. In addition, we call attention to the multiple challenges that we still need to face to enable the development of novel therapeutic approaches modulating α-Syn PTMs.

AT1 receptor autoantibodies mediate effects of metabolic syndrome on dopaminergic vulnerability

The metabolic syndrome has been associated to chronic peripheral inflammation and related with neuroinflammation and neurodegeneration, including Parkinson's disease. However, the responsible mechanisms are unclear. Previous studies have involved the brain renin-angiotensin system in progression of Parkinson's disease and the angiotensin receptor type 1 (AT1) has been recently revealed as a major marker of dopaminergic vulnerability in humans. Dysregulation of tissue renin-angiotensin system is a key common mechanism for all major components of metabolic syndrome. Circulating AT1 agonistic autoantibodies have been observed in several inflammation-related peripheral processes, and activation of AT1 receptors of endothelial cells, dopaminergic neurons and glial cells have been observed to disrupt endothelial blood -brain barrier and induce neurodegeneration, respectively. Using a rat model, we observed that metabolic syndrome induces overactivity of nigral pro-inflammatory renin-angiotensin system axis, leading to increase in oxidative stress and neuroinflammation and enhancing dopaminergic neurodegeneration, which was inhibited by treatment with AT1 receptor blockers (ARBs). In rats, metabolic syndrome induced the increase in circulating levels of LIGHT and other major pro-inflammatory cytokines, and 27-hydroxycholesterol. Furthermore, the rats showed a significant increase in serum levels of proinflammatory AT1 and angiotensin converting enzyme 2 (ACE2) autoantibodies, which correlated with levels of several metabolic syndrome parameters. We also found AT1 and ACE2 autoantibodies in the CSF of these rats. Effects of circulating autoantibodies were confirmed by chronic infusion of AT1 autoantibodies, which induced blood-brain barrier disruption, an increase in the pro-inflammatory renin-angiotensin system activity in the substantia nigra and a significant enhancement in dopaminergic neuron death in two different rat models of Parkinson's disease. Observations in the rat models, were analyzed in a cohort of parkinsonian and non-parkinsonian patients with or without metabolic syndrome. Non-parkinsonian patients with metabolic syndrome showed significantly higher levels of AT1 autoantibodies than non-parkinsonian patients without metabolic syndrome. However, there was no significant difference between parkinsonian patients with metabolic syndrome or without metabolic syndrome, which showed higher levels of AT1 autoantibodies than non-parkinsonian controls. This is consistent with our recent studies, showing significant increase of AT1 and ACE2 autoantibodies in parkinsonian patients, which was related to dopaminergic degeneration and neuroinflammation. Altogether may lead to a vicious circle enhancing the progression of the disease that may be inhibited by strategies against production of these autoantibodies or AT1 receptor blockers (ARBs).

Occurrence of Total and Proteinase K-Resistant Alpha-Synuclein in Glioblastoma Cells Depends on mTOR Activity

Simple Summary

The accumulation of alpha-synuclein (α-syn) is considered a pathological hallmark of the neurodegenerative disorders known as synucleinopathies. The clearance of α-syn depends on autophagy activity, which is inhibited by the mechanistic target of rapamycin (mTOR). Thus, it is likely that α-syn accumulation may occur whenever mTOR is overactive and autophagy is suppressed. In fact, the lack of effective autophagy increases the amount of α-syn and may produce protein aggregation. Therefore, in the present study, we questioned whether cells from glioblastoma multiforme (GBM), a lethal brain neoplasm, wherein mTOR is upregulated and autophagy is suppressed, may overexpress α-syn. In fact, a large quantity of α-syn is measured in GBM cells compared with astrocytes, which includes proteinase K-resistant α-syn. Rapamycin, while inhibiting mTOR activity, significantly reduces the amount of α-syn and allocates α-syn within autophagy-like vacuoles.

Abstract

Alpha-synuclein (α-syn) is a protein considered to be detrimental in a number of degenerative disorders (synucleinopathies) of which α-syn aggregates are considered a pathological hallmark. The clearance of α-syn strongly depends on autophagy, which can be stimulated by inhibiting the mechanistic target of rapamycin (mTOR). Thus, the overexpression of mTOR and severe autophagy suppression may produce α-syn accumulation, including the proteinase K-resistant protein isoform. Glioblastoma multiforme (GBM) is a lethal brain tumor that features mTOR overexpression and severe autophagy inhibition. Cell pathology in GBM is reminiscent of a fast, progressive degenerative disorder. Therefore, the present work questions whether, as is analogous to neurons during degenerative disorders, an overexpression of α-syn occurs within GBM cells. A high amount of α-syn was documented in GBM cells via real-time PCR (RT-PCR), Western blotting, immunohistochemistry, immuno-fluorescence, and ultrastructural stoichiometry, compared with the amount of β- and γ-synucleins and compared with the amount of α-syn counted within astrocytes. The present study indicates that (i) α-syn is overexpressed in GBM cells, (ii) α-syn expression includes a proteinase-K resistant isoform, (iii) α-syn is dispersed from autophagy-like vacuoles to the cytosol, (iv) α-syn overexpression and cytosol dispersion are mitigated by rapamycin, and (v) the α-syn-related GBM-like phenotype is mitigated by silencing the SNCA gene.

Using artificial intelligence to identify anti-hypertensives as possible disease modifying agents in Parkinson's disease

PURPOSE

Drug repurposing is an effective means of increasing treatment options for diseases, however identifying candidate molecules for the indication of interest from the thousands of approved drugs is challenging. We have performed a computational analysis of published literature to rank existing drugs according to predicted ability to reduce alpha synuclein (aSyn) oligomerization and analyzed real-world data to investigate the association between exposure to highly ranked drugs and PD.

METHODS

Using IBM Watson for Drug Discoveryâ (WDD) we identified several antihypertensive drugs that may reduce aSyn oligomerization. Using IBM MarketScanâ Research Databases we constructed a cohort of individuals with incident hypertension. We conducted univariate and multivariate Cox proportional hazard analyses (HR) with exposure as a time-dependent covariate. Diuretics were used as the referent group. Age at hypertension diagnosis, sex, and several comorbidities were included in multivariate analyses.

RESULTS

Multivariate results revealed inverse associations for time to PD diagnosis with exposure to the combination of the combination of angiotensin receptor II blockers (ARBs) and dihydropyridine calcium channel blockers (DHP-CCB) (HR = 0.55, p < 0.01) and angiotensin converting enzyme inhibitors (ACEi) and diuretics (HR = 0.60, p-value <0.01). Increased risk was observed with exposure to alpha-blockers alone (HR = 1.81, p < 0.001) and the combination of alpha-blockers and CCB (HR = 3.17, p < 0.05).

CONCLUSIONS

We present evidence that a computational approach can efficiently identify leads for disease-modifying drugs. We have identified the combination of ARBs and DHP-CCBs as of particular interest in PD.

Stroke promotes the development of brain atrophy and delayed cell death in hypertensive rats

Post-stroke cognitive impairment (PSCI) is a major source of disability, affecting up to two thirds of stroke survivors with no available therapeutic options. The condition remains understudied in preclinical models due to its delayed presentation. Although hypertension is a leading risk factor for dementia, how ischemic stroke contributes to this neurodegenerative condition is unknown. In this study, we used a model of hypertension to study the development of PSCI and its mechanisms. Spontaneously hypertensive rats (SHR) were compared to normotensive rats and were subjected to 1-h middle cerebral artery occlusion or sham surgery. Novel object recognition, passive avoidance test and Morris water maze were used to assess cognition. In addition, brain magnetic resonance images were obtained 12-weeks post-stroke and tissue was collected for immunohistochemistry and protein quantification. Stroked animals developed impairment in long-term memory at 4-weeks post-stroke despite recovery from motor deficits, with hypertensive animals showing some symptoms of anhedonia. Stroked SHRs displayed grey matter atrophy and had a two-fold increase in apoptosis in the ischemic borderzone and increased markers of inflammatory cell death and DNA damage at 12 weeks post-stroke. This indicates that preexisting hypertension exacerbates the development of secondary neurodegeneration after stroke beyond its acute effects on neurovascular injury.

α-Synuclein in traumatic and vascular diseases of the central nervous system

α-Synuclein (α-Syn) is a small, soluble, disordered protein that is widely expressed in the nervous system. Although its physiological functions are not yet fully understood, it is mainly involved in synaptic vesicle transport, neurotransmitter synthesis and release, cell membrane homeostasis, lipid synthesis, mitochondrial and lysosomal activities, and heavy metal removal. The complex and inconsistent pathological manifestations of α-Syn are attributed to its structural instability, mutational complexity, misfolding, and diverse posttranslational modifications. These effects trigger mitochondrial dysfunction, oxidative stress, and neuroinflammatory responses, resulting in neuronal death and neurodegeneration. Several recent studies have discovered the pathogenic roles of α-Syn in traumatic and vascular central nervous system diseases, such as traumatic spinal cord injury, brain injury, and stroke, and in aggravating the processes of neurodegeneration. This review aims to highlight the structural and pathophysiological changes in α-Syn and its mechanism of action in traumatic and vascular diseases of the central nervous system.

Cerebral ischemia induced inflammatory response and altered glutaminergic function mediated through brain AT1 and not AT2 receptor

In the present study, we investigated the effects of angiotensin (Ang II) receptor blockers in cerebral ischemia by administration of telmisartan (AT₁ blocker) and/or PD123319 (AT₂ blocker) in global ischemic mice model. The neuroprotective effect of AT antagonists was evaluated through monitoring muscle co-ordination and cerebral blood perfusion in ischemic mice. Gene expression studies (NF-κB, GSK-3β, EAAT-2, AT₁ & AT₂ receptors) and staining of brain regions with cresyl violet, GFAP, synaptophysin and NSE methods were carried out in to understand the molecular mechanisms. Further, the brain glutamate, cytokines, and Ang II peptide levels were evaluated and their correlation with EAAT-2 mRNA expression was performed. Our results indicate that the induction of ischemia elevates brain Ang II, cytokines, and glutamate levels and reduced muscle co-ordination and cerebral blood perfusion. The expressions of NF-κB, GSK-3β and AT₁ were significantly increased, whereas, EAAT-2 expression was decreased. Blocking of AT₁ receptors by telmisartan (TM) reversed the detrimental responses of cerebral ischemia and restored the cerebral blood flow denoting blockade of Ang II/AT₁ pathway is beneficial in ischemia, whereas, blockade of AT₂ receptors by PD123319 (PD) increased the ischemic injury in mice. This vulnerable effect of PD may be attributed through augmenting the Ang II/AT₁ dependent cytokines mediated glutamate transporter (EAAT-2) dysfunction. Interestingly, the beneficial effects of AT₁ blocker was remarkably antagonized by AT₂ blocker in most of the parameters studied in ischemic conditions. Also, the expression of AT₂ receptors was significantly increased compared to that of AT₁ receptors upon ischemic induction. It denotes that the endogenous Ang II predominantly acts on AT₂ receptor, thereby promoting its own mRNA transcription. Hence, the increased expression of AT₂ receptors in ischemic condition could be used as target protein for therapeutic benefit.

Alpha-Synuclein Glycation and the Action of Anti-Diabetic Agents in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative disorder with complex etiology and variable pathology. While a subset of cases is associated with single-gene mutations, the majority originates from a combination of factors we do not fully understand. Thus, understanding the underlying causes of PD is indispensable for the development of novel therapeutics. Glycation, the non-enzymatic reaction between reactive dicarbonyls and amino groups, gives rise to a variety of different reaction products known as advanced glycation end products (AGEs). AGEs accumulate over a proteins life-time, and increased levels of glycation reaction products play a role in diabetic complications. It is now also becoming evident that PD patients also display perturbed sugar metabolism and protein glycation, including that of alpha-synuclein, a key player in PD. Here, we hypothesize that anti-diabetic drugs targeting the levels of glycation precursors, or promoting the clearance of glycated proteins may also prove beneficial for PD patients.

Elevated serum MDA and depleted non-enzymatic antioxidants, macro-minerals and trace elements are associated with bipolar disorder

Genetic and neurobiological factors are considered to be the major causes of mood and mental disorders. However, over the past few years, increased levels of serum malondialdehyde and altered levels of various non-enzymatic antioxidants and essential minerals involved in abnormal functional activity have been identified as major contributing factors to the pathogenesis of several neurological disorders. The aim of this study was to determine the levels of the serum lipid peroxidation product malondialdehyde (MDA), antioxidants (vitamin A, E and C), macro-minerals (calcium, potassium and sodium) and trace elements (zinc, iron and selenium) in patients with bipolar disorder and to explore their role in disease progression. This is a prospective case-control study that evaluated 55 patients with bipolar disorder and 55 healthy volunteers matched by age and sex. Serum MDA levels were determined by UV spectrophotometry as a marker of lipid peroxidation. RP-HPLC was employed to investigate the serum vitamin A and E concentrations, whereas UV spectrophotometry was used to quantify levels of vitamin C. Serum macro-minerals and trace elements were analyzed by atomic absorption spectroscopy (AAS). Statistical analysis was performed with independent sample t-tests and Pearson's correlation test. We found significantly higher concentrations of MDA (p<0.05) and significantly lower concentrations of antioxidants (vitamin A, E and C) (p<0.05) in the patient group compared with control group. Regarding trace elements and macro-minerals, lower concentrations of zinc, calcium, iron, selenium, sodium and potassium were found in the patient group compared with control subjects (p<0.05). Our study suggests that high serum MDA concentrations and low serum concentrations of antioxidants, macro-minerals and trace elements are strongly associated with bipolar disorder.

Effect of glycation inhibitors on aging and age-related diseases

Vast evidence supports the view that glycation of proteins is one of the main factors contributing to aging and is an important element of etiopathology of age-related diseases, especially type 2 diabetes mellitus, cataract and neurodegenerative diseases. Counteracting glycation can therefore be a means of increasing both the lifespan and healthspan. In this review, accumulation of glycation products during aging is presented, pathophysiological effects of glycation are discussed and ways of attenuation of the effects of glycation are described, concentrating on prevention of glycation. The effects of glycation and glycation inhibitors on the course of selected age-related diseases, such as Alzheimer's disease, Parkinson's disease and cataract are also reviewed.

Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease

We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.

Inhibition of endoplasmic reticulum stress-activated IRE1α-TRAF2-caspase-12 apoptotic pathway is involved in the neuroprotective effects of telmisartan in the rotenone rat model of Parkinson's disease

Telmisartan, one unique angiotensin II type 1 receptor blocker, has been attracting attention due to its putative peroxisome proliferator-activated receptor (PPAR)-γ or β/δ actions. Recently, telmisartan has been reported to exert neuroprotective effects in animal models of Parkinson's disease (PD). However, the underlying mechanisms have not been fully clarified. Recently, accumulating evidence has shown that endoplasmic reticulum (ER) stress plays a crucial role in rotenone-induced neuronal apoptosis. Additionally, studies have revealed that inositol-requiring enzyme/endonuclease 1α (IRE1α) is necessary and sufficient to trigger ER stress. In the present study, we aimed to determine whether ER stress-activated IRE1α-mediated apoptotic pathway is involved in the neuroprotection of telmisartan in the rotenone rats of PD and explore the possible involvement of PPAR-β/δ activation. The catalepsy tests were performed to test the catalepsy symptom. The dopamine content and α-synuclein expression were ascertained through high-performance liquid chromatography and immunohistochemistry, respectively. The expression of IRE1α, TNF receptor associated factor 2 (TRAF2), caspase-12 and PPAR-β/δ was detected by western blot. Neuronal apoptosis was assessed by TUNEL and immunohistochemistry. Our results show that telmisartan ameliorated the catalepsy symptom and attenuated dopamine depletion as well as α-synuclein accumulation. Moreover, telmisartan decreased ER stress-mediated neuronal apoptosis. Furthermore, telmisartan inhibited IRE1α-TRAF2-caspase-12 apoptotic signaling pathway. Additionally, telmisartan activated PPAR β/δ, implying that PPAR-β/δ activation properties of telmisartan are possibly or partially involved in the neuroprotective effects. In conclusion, our findings suggest that suppressing ER stress-activated IRE1α-TRAF2-caspase-12 apoptotic pathway is involved in the neuroprotective effects of telmisartan in the rotenone rats of PD.

Parkinson's disease between internal medicine and neurology

General medical problems and complications have a major impact on the quality of life in all stages of Parkinson's disease. To introduce an effective treatment, a comprehensive analysis of the various clinical symptoms must be undertaken. One must distinguish between (1) diseases which arise independently of Parkinson's disease, and (2) diseases which are a direct or indirect consequence of Parkinson's disease. Medical comorbidity may induce additional limitations to physical strength and coping strategies, and may thus restrict the efficacy of the physical therapy which is essential for treating hypokinetic-rigid symptoms. In selecting the appropriate medication for the treatment of any additional medical symptoms, which may arise, its limitations, contraindications and interactions with dopaminergic substances have to be taken into consideration. General medical symptoms and organ manifestations may also arise as a direct consequence of the autonomic dysfunction associated with Parkinson's disease. As the disease progresses, additional non-parkinsonian symptoms can be of concern. Furthermore, the side effects of Parkinson medications may necessitate the involvement of other medical specialists. In this review, we will discuss the various general medical aspects of Parkinson's disease.

Generation of SNCA Cell Models Using Zinc Finger Nuclease (ZFN) Technology for Efficient High-Throughput Drug Screening

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by loss of dopaminergic neurons of the substantia nigra. The hallmark of PD is the appearance of neuronal protein aggregations known as Lewy bodies and Lewy neurites, of which α-synuclein forms a major component. Familial PD is rare and is associated with missense mutations of the SNCA gene or increases in gene copy number resulting in SNCA overexpression. This suggests that lowering SNCA expression could be therapeutic for PD. Supporting this hypothesis, SNCA reduction was neuroprotective in cell line and rodent PD models. We developed novel cell lines expressing SNCA fused to the reporter genes luciferase (luc) or GFP with the objective to enable high-throughput compound screening (HTS) for small molecules that can lower SNCA expression. Because SNCA expression is likely regulated by far-upstream elements (including the NACP-REP1 located at 8852 bp upstream of the transcription site), we employed zinc finger nuclease (ZFN) genome editing to insert reporter genes in-frame downstream of the SNCA gene in order to retain native SNCA expression control. This ensured full retention of known and unknown up- and downstream genetic elements controlling SNCA expression. Treatment of cells with the histone deacetylase inhibitor valproic acid (VPA) resulted in significantly increased SNCA-luc and SNCA-GFP expression supporting the use of our cell lines for identifying small molecules altering complex modes of expression control. Cells expressing SNCA-luc treated with a luciferase inhibitor or SNCA siRNA resulted in Z'-scores ≥ 0.75, suggesting the suitability of these cell lines for use in HTS. This study presents a novel use of genome editing for the creation of cell lines expressing α-synuclein fusion constructs entirely under native expression control. These cell lines are well suited for HTS for compounds that lower SNCA expression directly or by acting at long-range sites to the SNCA promoter and 5'-UTR.

Telmisartan ameliorates inflammatory responses in SHR-SR after tMCAO

Telmisartan, an angiotensin receptor blocker with high lipid solubility, also called metabo-sartan, not only reduces blood pressure (BP), but also ameliorates inflammation in the cerebral cortex and in adipose tissue. We examined the effects of telmisartan on inflammatory responses of monocyte chemotactic protein-1, tumor necrosis factor-α, and ionized calcium-binding adapter molecule 1 in the brain of spontaneously hypertensive rat stroke-resistant (SHR-SR) after transient middle cerebral artery occlusion (tMCAO). At 12 weeks of age, SHR-SR received tMCAO for 90 minutes and were divided into 3 groups, that is, the vehicle group, a low-dose telmisartan group (.3 mg/kg/day), and a high-dose telmisartan group (3 mg/kg/day). Immunohistological analysis was performed when rats became 6, 12 and 18 months old. Monocyte chemotactic protein-1, tumor necrosis factor-α, and ionized calcium-binding adapter molecule 1 cells (/mm(2)) immunoreactivities increased with age in the cerebral cortex and hippocampus of the vehicle group, suggesting strong and persistent inflammatory changes in SHR-SR after tMCAO up to 18 months of age. On the other hand, a low dose of telmisartan significantly reduced such inflammatory changes without lowering BP, whereas a high dose of telmisartan showed a few additional improvements, including the lowering of BP throughout 6-18 months of age. The present study suggests that persistent hypertension after tMCAO caused a long-lasting inflammatory response in the SHR-SR brain, and that even a low dose of telmisartan reduced continuous inflammation without lowering BP via its pleiotropic effects in the SHR-SR brain. A high dose of telmisartan had a few additional benefits, including lowering BP.