P-tau217 correlates with neurodegeneration in Alzheimer's disease, and targeting p-tau217 with immunotherapy ameliorates murine tauopathy.

Neuronal loss is the central issue in Alzheimer's disease (AD), yet no treatment developed so far can halt AD-associated neurodegeneration. Here, we developed a monoclonal antibody (mAb2A7) against 217 site-phosphorylated human tau (p-tau217) and observed that p-tau217 levels positively correlated with brain atrophy and cognitive impairment in AD patients. Intranasal administration efficiently delivered mAb2A7 into male PS19 tauopathic mouse brain with target engagement and reduced tau pathology/aggregation with little effect on total soluble tau. Further, mAb2A7 treatment blocked apoptosis-associated neuronal loss and brain atrophy, reversed cognitive deficits, and improved motor function in male tauopathic mice. Proteomic analysis revealed that mAb2A7 treatment reversed alterations mainly in proteins associated with synaptic functions observed in murine tauopathy and AD brain. An antibody (13G4) targeting total tau also attenuated tau-associated pathology and neurodegeneration but impaired the motor function of male tauopathic mice. These results implicate p-tau217 as a potential therapeutic target for AD-associated neurodegeneration.

Inhibitory effect of parthenolide on peripheral nerve degeneration.

Traumatic axonal damage disrupts connections between neurons, leading to the loss of motor and sensory functions. Although damaged peripheral nerves can regenerate, recovery depends on the variety and severity of nerve damage. Thus, many phytochemicals have been studied for their ability to reduce peripheral nerve degeneration, and among them, Parthenolide (PTL), which is extracted from Feverfew has effects against production of free radicals, inflammation, and apoptosis. Thus, we conducted a study to investigate whether PTL has an inhibitory effect on peripheral nerve degeneration during peripheral nerve damage. To verify the effect of PTL on peripheral nerve degeneration process, a morphological comparison of peripheral nerves with and without PTL was performed. PTL significantly reduced the quantity of fragmented ovoid formations at 3DIV (days in vitro). Immunostaining for MBP revealed that the ratio of intact myelin sheaths increased significantly in sciatic nerve with PTL compared with absence of PTL at 3DIV. Furthermore, nerve fibers in the presence of PTL maintained the continuity of Neurofilament (NF) compared to those without at 3DIV. Immunostaining for LAMP1 and p75 NTR showed that the expression of LAMP1 and p75 NTR decreased in the nerve after PTL addition at 3DIV. Lastly, immunostaining for anti-Ki67 revealed that PTL inhibited Ki67 expression at 3DIV compared to without PTL. These results confirm that PTL inhibits peripheral nerve degenerative processes. PTL may be a good applicant to inhibit peripheral nerve degeneration. Our study examined the effect of Parthenolide in preventing degeneration of peripheral nerves by inhibiting the breakdown of peripheral axons and myelin, also inhibiting Schwann cell trans-dedifferentiation and proliferation.

Targeting NAAA counters dopamine neuron loss and symptom progression in mouse models of parkinsonism.

The lysosomal cysteine hydrolase N-acylethanolamine acid amidase (NAAA) deactivates palmitoylethanolamide (PEA), a lipid-derived PPAR-α agonist that is critically involved in the control of pain and inflammation. In this study, we asked whether NAAA-regulated PEA signaling might contribute to dopamine neuron degeneration and parkinsonism induced by the mitochondrial neurotoxins, 6-hydroxydopamine (6-OHDA) and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). In vitro experiments showed that 6-OHDA and MPTP enhanced NAAA expression and lowered PEA content in human SH-SY5Y cells. A similar effect was observed in mouse midbrain dopamine neurons following intra-striatal 6-OHDA injection. Importantly, deletion of the Naaa gene or pharmacological inhibition of NAAA activity substantially attenuated both dopamine neuron death and parkinsonian symptoms in mice treated with 6-OHDA or MPTP. Moreover, NAAA expression was elevated in postmortem brain cortex and premortem blood-derived exosomes from persons with Parkinson's disease compared to age-matched controls. The results identify NAAA-regulated PEA signaling as a molecular control point for dopaminergic neuron survival and a potential target for neuroprotective intervention.

Protective and therapeutic effect of (S)-ginsenoside F1 on peripheral nerve degeneration targeting Schwann cells: a pharmaco-neuroanatomical approach.

Damaged peripheral nerves undergo peripheral neurodegenerative processes that are essential for the nerve regeneration. Peripheral neurodegenerative diseases, including diabetic peripheral neuropathy, are induced by irreversible nerve damage caused by abnormal peripheral nerve degeneration. However, until now, there have been no effective therapeutic treatments for these diseases. Ginsenosides are the most pharmacologically active compounds in Panax ginseng, and are being actively studied. Ginsenosides have a variety of effects, including neuroprotective, antioxidative, anti-cytotoxic, and anti-inflammatory effects. Here, we investigated the efficacy of 18 ginsenosides. We then tested the ability of the most effective ginsenoside, (S)-ginsenosides F1 (sF1), to inhibit peripheral neurodegenerative processes using mouse sciatic ex vivo culture, and several morphological and biochemical indicators. Our results suggest that sF1 could effectively protect Schwann cells against peripheral nerve degeneration.

Sarm1 haploinsufficiency or low expression levels after antisense oligonucleotides delay programmed axon degeneration.

Activation of the pro-degenerative protein SARM1 after diverse physical and disease-relevant injuries causes programmed axon degeneration. Original studies indicate that substantially decreased SARM1 levels are required for neuroprotection. However, we demonstrate, in Sarm1 haploinsufficient mice, that lowering SARM1 levels by 50% delays programmed axon degeneration in vivo after sciatic nerve transection and partially prevents neurite outgrowth defects in mice lacking the pro-survival factor NMNAT2. In vitro, the rate of degeneration in response to traumatic, neurotoxic, and genetic triggers of SARM1 activation is also slowed. Finally, we demonstrate that Sarm1 antisense oligonucleotides decrease SARM1 levels by more than 50% in vitro, which delays or prevents programmed axon degeneration. Combining Sarm1 haploinsufficiency with antisense oligonucleotides further decreases SARM1 levels and prolongs protection after neurotoxic injury. These data demonstrate that axon protection occurs in a Sarm1 gene dose-responsive manner and that SARM1-lowering agents have therapeutic potential, making Sarm1-targeting antisense oligonucleotides a promising therapeutic strategy.

Evaluation of a 5-HT2B receptor agonist in a murine model of amyotrophic lateral sclerosis.

Degeneration of brainstem serotonin neurons has been demonstrated in ALS patients and mouse models and was found responsible for the development of spasticity. Consistent with involvement of central serotonin pathways, 5-HT2B receptor (5-HT2BR) was upregulated in microglia of ALS mice. Its deletion worsened disease outcome in the Sod1G86R mouse model and led to microglial degeneration. In ALS patients, a polymorphism in HTR2B gene leading to higher receptor expression in CNS, was associated with increased survival in patients as well as prevention of microglial degeneration. Thus, the aim of our study was to determine the effect of a 5-HT2BR agonist : BW723C86 (BW), in the Sod1G86R mouse model. Despite good pharmacokinetic and pharmacological profiles, BW did not ameliorate disease outcome or motor neuron degeneration in a fast progressing mouse model of ALS despite evidence of modulation of microglial gene expression.

Early Intervention and Lifelong Treatment with GLP1 Receptor Agonist Liraglutide in a Wolfram Syndrome Rat Model with an Emphasis on Visual Neurodegeneration, Sensorineural Hearing Loss and Diabetic Phenotype.

Wolfram syndrome (WS), also known as a DIDMOAD (diabetes insipidus, early-onset diabetes mellitus, optic nerve atrophy and deafness) is a rare autosomal disorder caused by mutations in the Wolframin1 (WFS1) gene. Previous studies have revealed that glucagon-like peptide-1 receptor agonist (GLP1 RA) are effective in delaying and restoring blood glucose control in WS animal models and patients. The GLP1 RA liraglutide has also been shown to have neuroprotective properties in aged WS rats. WS is an early-onset, chronic condition. Therefore, early diagnosis and lifelong pharmacological treatment is the best solution to control disease progression. Hence, the aim of this study was to evaluate the efficacy of the long-term liraglutide treatment on the progression of WS symptoms. For this purpose, 2-month-old WS rats were treated with liraglutide up to the age of 18 months and changes in diabetes markers, visual acuity, and hearing sensitivity were monitored over the course of the treatment period. We found that treatment with liraglutide delayed the onset of diabetes and protected against vision loss in a rat model of WS. Therefore, early diagnosis and prophylactic treatment with the liraglutide may also prove to be a promising treatment option for WS patients by increasing the quality of life.

SCFA Treatment Alleviates Pathological Signs of Migraine and Related Intestinal Alterations in a Mouse Model of NTG-Induced Migraine.

BACKGROUND: There is a growing realization that the gut-brain axis signaling is critical for maintaining the health and homeostasis of the Central Nervous System (CNS) and the intestinal environment. The role of Short-Chain Fatty Acids (SCFAs), such as Sodium Propionate (SP) and Sodium Butyrate (SB), has been reported to counteract inflammation activation in the central and Enteric Nervous System (ENS). METHODS: In this study, we evaluated the role of the SCFAs in regulating the pathophysiology of migraine and correlated dysregulations in the gut environment in a mouse model of Nitroglycerine (NTG)-induced migraine. RESULTS: We showed that, following behavioral tests evaluating pain and photophobia, the SP and SB treatments attenuated pain attacks provoked by NTG. Moreover, treatments with both SCFAs reduced histological damage in the trigeminal nerve nucleus and decreased the expression of proinflammatory mediators. Ileum evaluation following NTG injection reported that SCFA treatments importantly restored intestinal mucosa alterations, as well as the release of neurotransmitters in the ENS. CONCLUSIONS: Taken together, these results provide evidence that SCFAs exert powerful effects, preventing inflammation through the gut-brain axis, suggesting a new insight into the potential application of SCFAs as novel supportive therapies for migraine and correlated intestinal alterations.

A microfluidic approach to rescue ALS motor neuron degeneration using rapamycin.

TAR DNA-binding protein-43 (TDP-43) is known to accumulate in ubiquitinated inclusions of amyotrophic lateral sclerosis affected motor neurons, resulting in motor neuron degeneration, loss of motor functions, and eventually death. Rapamycin, an mTOR inhibitor and a commonly used immunosuppressive drug, has been shown to increase the survivability of Amyotrophic Lateral Sclerosis (ALS) affected motor neurons. Here we present a transgenic, TDP-43-A315T, mouse model expressing an ALS phenotype and demonstrate the presence of ubiquitinated cytoplasmic TDP-43 aggregates with > 80% cell death by 28 days post differentiation in vitro. Embryonic stem cells from this mouse model were used to study the onset, progression, and therapeutic remediation of TDP-43 aggregates using a novel microfluidic rapamycin concentration gradient generator. Results using a microfluidic device show that ALS affected motor neuron survival can be increased by 40.44% in a rapamycin dosage range between 0.4-1.0 µM.

Biological Actions and Molecular Mechanisms of Sambucus nigra L. in Neurodegeneration: A Cell Culture Approach.

Sambucus nigra flowers (elderflower) have been widely used in traditional medicine for the relief of early symptoms of common cold. Its chemical composition mainly consists of polyphenolic compounds such as flavonoids, hydroxycinnamic acids, and triterpenes. Although the antioxidant properties of polyphenols are well known, the aim of this study is to assess the antioxidant and protective potentials of Sambucus nigra flowers in the human neuroblastoma (SH-SY5Y) cell line using different in vitro approaches. The antioxidant capacity is first evaluated by the oxygen radical absorbance capacity (ORAC) and the free radical scavenging activity (DPPH) methods. Cell viability is assessed by the crystal violet method; furthermore, the intracellular ROS formation (DCFH-DA method) is determined, together with the effect on the cell antioxidant defenses: reduced glutathione (GSH) and antioxidant enzyme activities (GPx, GR). On the other hand, mTORC1 hyperactivation and autophagy blockage have been associated with an increase in the formation of protein aggregates, this promoting the transference and expansion of neurodegenerative diseases. Then, the ability of Sambucus nigra flowers in the regulation of mTORC1 signaling activity and the reduction in oxidative stress through the activation of autophagy/mitophagy flux is also examined. In this regard, search for different molecules with a potential inhibitory effect on mTORC1 activation could have multiple positive effects either in the molecular pathogenic events and/or in the progression of several diseases including neurodegenerative ones.

Design of Multifaceted Antioxidants: Shifting towards Anti-Inflammatory and Antihyperlipidemic Activity.

Oxidative stress and inflammation are two conditions that coexist in many multifactorial diseases such as atherosclerosis and neurodegeneration. Thus, the design of multifunctional compounds that can concurrently tackle two or more therapeutic targets is an appealing approach. In this study, the basic NSAID structure was fused with the antioxidant moieties 3,5-di-tert-butyl-4-hydroxybenzoic acid (BHB), its reduced alcohol 3,5-di-tert-butyl- 4-hydroxybenzyl alcohol (BHBA), or 6-hydroxy-2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), a hydrophilic analogue of α-tocopherol. Machine learning algorithms were utilized to validate the potential dual effect (anti-inflammatory and antioxidant) of the designed analogues. Derivatives 1-17 were synthesized by known esterification methods, with good to excellent yields, and were pharmacologically evaluated both in vitro and in vivo for their antioxidant and anti-inflammatory activity, whereas selected compounds were also tested in an in vivo hyperlipidemia protocol. Furthermore, the activity/binding affinity of the new compounds for lipoxygenase-3 (LOX-3) was studied not only in vitro but also via molecular docking simulations. Experimental results demonstrated that the antioxidant and anti-inflammatory activities of the new fused molecules were increased compared to the parent molecules, while molecular docking simulations validated the improved activity and revealed the binding mode of the most potent inhibitors. The purpose of their design was justified by providing a potentially safer and more efficient therapeutic approach for multifactorial diseases.

Linagliptin, a DPP-4 inhibitor, ameliorates Aß (1-42) peptides induced neurodegeneration and brain insulin resistance (BIR) via insulin receptor substrate-1 (IRS-1) in rat model of Alzheimer's disease.

Alzheimer's disease (AD) is the most devastating neurodegenerative disorder, accounting over 46 million cases of dementia globally. Evidence supports that Brain Insulin Resistance (BIR) due to serine phosphorylation of Insulin Receptor Substrate-1 (IRS-1) has an association with AD. GLP-1 an incretin hormone, rapidly degraded by Dipeptidyl Peptidase-4 (DPP-4) has also confirmed its efficacious role in AD. Linagliptin, a DPP-4 inhibitor is hypothesized to increase GLP-1 level, which then crosses Blood Brain Barrier (BBB), decreases Amyloid-beta (Aß) and insulin resistance in hippocampus. Thus, the present study was designed to evaluate Linagliptin in Aß (1-42) peptides induced rat model of AD. Following 1 week of induction, rats were administered with Linagliptin (0.513 mg/kg, 3 mg/kg, and 5 mg/kg) orally for 8 weeks and donepezil (5 mg/kg) as a reference standard. At the end of scheduled treatment neurobehavioral parameters were assessed. After this, rats were sacrificed, hippocampus was isolated from the whole brain for histopathological analysis and biochemical parameters estimation. Linagliptin dose-dependently and significantly reversed motor and cognitive impairment, assessed through locomotor activity (LA) and Morris water maze (MWM) test respectively. Moreover, Linagliptin augmented GLP-1 level and attenuated soluble Aß (1-42), IRS-1 (s307), GSK-3ß, TNF-α, IL-1ß, IL-6, AchE and oxidative/nitrosative stress level in hippocampus. H&E and Congo red staining also exhibited neuroprotective and anti-amylodogenic effect respectively. Our study findings implies the significant effect of Linagliptin in reversing the behavioural and biochemical deficits by altering Aß (1-42) and BIR via IRS-1 confirming one of the mechanism underlying the pathophysiology of AD.

Protective effects of duloxetine against chronic immobilisation stress-induced anxiety, depression, cognitive impairment and neurodegeneration in mice.

OBJECTIVES: This study aimed to evaluate the effect of duloxetine (10 and 20 mg/kg) against chronic immobilisation stress (CIS)-induced anxiety, depression, cognitive impairment and neurodegeneration in mice. METHODS: CIS, 2 h/10 days (11:00 AM-1:00 PM) was applied after 30 min of pretreatment with saline, duloxetine 10 mg/kg and 20 mg/kg to the respective groups of animals, except the control group. Animals were examined for physiological (body weight, locomotion and grip strength), psychological (memory impairment, anxiety and depression), neurochemical (GABA and glutamate), biochemical (MDA, catalase, glutathione, superoxide dismutase) and histopathological changes. KEY FINDINGS: CIS exposure revealed anxiety-like behaviour, depression-like behaviour, motor in-coordination and learning and memory impairment in mice. Besides, CIS induction decreased the antioxidant enzymes (GSH, SOD and catalase), GABA and the viable neuronal cell count, whereas CIS exposure significantly elevated the MDA, AChE activity and glutamate content in the cortex and hippocampus. Pretreatment with duloxetine10 and 20 mg/kg showed dose-dependent ameliorated effect against the CIS-induced alterations in mice. CONCLUSION: In conclusion, the results of this study demonstrated the protective effect of duloxetine against neuropsychiatric symptoms, memory impairment caused by CIS-induction through inhibition of oxidative stress, AChE activity and glutamate release.

Carnosine improves aging-induced cognitive impairment and brain regional neurodegeneration in relation to the neuropathological alterations in the secondary structure of amyloid beta (Aß).

Aging-induced proteinopathies, including deterioration of amyloid beta (Aß) conformation, are associated with reductions in endogenous levels of carnosine and cognitive impairments. Carnosine is a well-known endogenous antioxidant, which counteracts aging-induced Aß plaque formation. The aim of this study was to investigate the effects of exogenous carnosine treatments on aging-induced changes (a) in the steady-state level of endogenous carnosine and conformation of Aß secondary structure in the different brain regions (cerebral cortex, hippocampus, hypothalamus, pons-medulla, and cerebellum) and (b) cognitive function. Young (4 months) and aged (18 and 24 months) male albino Wistar rats were treated with carnosine (2.0 µg kg-1  day-1 ; i.t.) or equivalent volumes of vehicle (saline) for 21 consecutive days and were tested for cognition using 8-arm radial maze test. Brains were processed to assess the conformational integrity of Aß plaques using Raman spectroscopy and endogenous levels of carnosine were measured in the brain regions using HPLC. Results indicated that carnosine treatments improved the aging-induced deficits in cognitive function and reduced the ß-sheets in the secondary structure of Aß protein, as well as mitigating the reduction in the steady-state levels of carnosine and spine density in the brain regions examined. These results thus, suggest that carnosine can attenuate the aging-induced: (a) conformational changes in Aß secondary structure by reducing the abundance of ß-sheets and reductions in carnosine content in the brain regions and (b) cognitive impairment.

Parkinson's Disease: Is there a Role for Dietary and Herbal Supplements?

Parkinson's Disease (PD) is characterised by degeneration of the neurons of the nigrostriatal dopaminergic pathway of the brain. The pharmacological cornerstone of PD management is mainly the use of dopamine precursors, dopamine receptor agonists, and agents that inhibit the biochemical degradation of dopamine. While these drugs initially provide relief to the symptoms and improve the quality of life of the patients, progression of the underlying pathological processes, such as oxidative stress and neuroinflammation (which have been strongly associated with PD and other neurodegenerative disorders), eventually reduce their benefits, making further benefits achievable, only at high doses due to which the magnitude and frequency of side-effects are amplified. Also, while it is becoming obvious that mainstream pharmacological agents may not always provide the much-needed answer, the question remains what succour can nature provide through dietary supplements, nutraceuticals and herbal remedies? This narrative review examines current literature for evidence of the possible roles (if any) of nutraceuticals, dietary supplements and herbal remedies in the prevention or management of PD by examining how these compounds could modulate key factors and pathways that are crucial to the pathogenesis and/or progression of PD. The likely limitations of this approach and its possible future roles in PD prevention and management are also considered.

Neuroprotective Effect of Protaetia brevitarsis seulensis' Water Extract on Trimethyltin-Induced Seizures and Hippocampal Neurodegeneration.

This study aimed to investigate whether the Protaetia brevitarsis seulensis (PB)' water extract (PBWE) ameliorates trimethyltin (TMT)-induced seizures and hippocampal neurodegeneration. To investigate the potential neuroprotective effect of the PBWE in vitro, a lactate dehydrogenase (LDH) assay was conducted in TMT-treated primary cultures of mouse hippocampal neurons. In TMT-treated adult C57BL/6 mice, behavioral and histopathological changes were evaluated by seizure scoring and Fluoro-Jade C staining, respectively. In our in vitro assay, we observed that pretreating mice hippocampal neuron cultures with the PBWE reduced TMT-induced cytotoxicity, as indicated by the decreased LDH release. Furthermore, pretreatment with the PBWE alleviated seizures and hippocampal neurodegeneration in TMT-treated mice. The antioxidant activity of the PBWE increased in a dose-dependent manner; moreover, pretreatment with the PBWE mitigated the TMT-induced Nrf2 stimulation. In addition, six major compounds, including adenine, hypoxanthine, uridine, adenosine, inosine, and benzoic acid, were isolated from the PBWE, and among them, inosine and benzoic acid have been confirmed to have an essential antioxidative activity. In conclusion, the PBWE ameliorated TMT-induced toxicity in hippocampal neurons in both in vitro and in vivo assays, through a potential antioxidative effect. Our findings suggest that the PBWE may have pharmacotherapeutic potential in neurodegenerative diseases such as seizures or epilepsy.

Neuroprotective effect of damaurone D in a C. elegans model of Parkinson's disease.

In this study, we evaluated the protective effects of damaurone D (DaD), a dihydropyranoaurone compound, on dopaminergic (DA) neurodegeneration in Caenorhabditis elegans. The results showed that DaD treatment could successfully increase the survival rate of the worms under MPP+ exposure. Additionally, DaD protected against the MPP+-induced neurodegeneration in all eight DA neurons of the worms. Similarly, diminished DA neuronal damage was observed in the DaD-fed transgenic mutant overexpressing tyrosine hydroxylase. In addition, the corresponding behavioral impairment induced by MPP+ was strongly improved in the DaD treated worms, implying DaD has protective properties for DA neuronal function. Then, we further investigated the effect of DaD on α-synuclein aggregation, a key pathogenesis of Parkinson's disease (PD). In this study, DaD reduced the fluorescence signals of transgenic mutants that carried YFP-fused α-synuclein. A similar reduction in expressions of α-synuclein was observed by Western blot. Interestingly, our result from the dot-blot assay demonstrated that the formation of oligomers was significantly attenuated by the DaD treatment. Furthermore, DaD improved the abnormal fat storage and shortened lifespan of the animals with the same genetic background which supports the beneficial action of DaD on the α-synuclein-induced DA neurodegeneration. These results demonstrate that DaD could protect against both chemical- and genetic-induced DA neurodegeneration possibly through the modulation of oxidative stress, DA metabolism, and α-synuclein toxicity. Based on our present findings, we suggest that DaD might have a potential therapeutic role in Parkinson's disease.

Small Molecule SARM1 Inhibitors Recapitulate the SARM1-/- Phenotype and Allow Recovery of a Metastable Pool of Axons Fated to Degenerate.

Axonal degeneration is responsible for disease progression and accumulation of disability in many neurodegenerative conditions. The axonal degenerative process can generate a metastable pool of damaged axons that remain structurally and functionally viable but fated to degenerate in the absence of external intervention. SARM1, an NADase that depletes axonal energy stores upon activation, is the central driver of an evolutionarily conserved program of axonal degeneration. We identify a potent and selective small molecule isoquinoline inhibitor of SARM1 NADase that recapitulates the SARM1-/- phenotype and protects axons from degeneration induced by axotomy or mitochondrial dysfunction. SARM1 inhibition post-mitochondrial injury with rotenone allows recovery and rescues axons that already entered the metastable state. We conclude that SARM1 inhibition with small molecules has the potential to treat axonopathies of the central and peripheral nervous systems by preventing axonal degeneration and by allowing functional recovery of a metastable pool of damaged, but viable, axons.

Atorvastatin Prevents the Neuron Loss in the Hippocampal Dentate Gyrus Region through its Anti-Oxidant and Anti-Apoptotic Activities.

BACKGROUND: Atorvastatin is a member of statins, which has shown positive vascular effects, anti-oxidant, anti-platelet, and anti-apoptotic properties. OBJECTIVE: In this study, we hypothesized that atorvastatin could prevent the neurons lost in the hippocampal dentate gyrus region after transient global Ischemia/Reperfusion (I/R) through its anti- oxidant and anti-apoptotic activities. METHOD: Twenty-four male Wistar rats, 12-13 weeks old and weighing 250-300 g, were divided randomly into four groups: control, I/R, vehicle (I/R treated with NaCl) and experiment (I/R treated with atorvastatin, 10 mg/kg); rats were sacrificed 96 hours after I/R. Quantitative expression of genes (caspase 8, p53, bax, bcl2, cytochrome c) was studied. The MDA level, SOD, CAT, and GPx activities were measured with biochemical tests. To detect apoptotic cells, TUNEL and Nissl staining were performed. Mitochondria were prepared from the hippocampus rats and used for the quantification of mitochondrial ROS, ATP level, GSH content, membrane potential, cytochrome c release, and determination of mitochondrial swelling. RESULTS: Atorvastatin attenuated the overexpression of bax, cytochrome C, p53, and caspase8 mRNAs and induced expression of bcl-2 mRNA (P<0.001). Atorvastatin treatment increased anti-oxidant enzyme levels (P<0.01). Treatment with atorvastatin reduced the number of TUNEL-positive cells. It could decrease the cytochrome c release (P<0.01), inhibit the decrease of MMP (P<0.001) and increase the ATP level (P<0.001) in hippocampal mitochondria compared with the I/R group. CONCLUSION: Atorvastatin treatment in I/R rats decreases oxidative stress, production of ROS, apoptosis rate in neuronal cells, and improves the mitochondrial function. Hence, atorvastatin has a proper neuronal protective effect against the I/R injury in the brain.

Peripheral inflammation exacerbates α-synuclein toxicity and neuropathology in Parkinson's models.

AIMS: Parkinson's disease and related disorders are devastating neurodegenerative pathologies. Since α-synuclein was identified as a main component of Lewy bodies and neurites, efforts have been made to clarify the pathogenic mechanisms of α-synuclein's detrimental effects. α-synuclein oligomers are the most harmful species and may recruit and activate glial cells. Inflammation is emerging as a bridge between genetic susceptibility and environmental factors co-fostering Parkinson's disease. However, direct evidence linking inflammation to the harmful activities of α-synuclein oligomers or to the Parkinson's disease behavioural phenotype is lacking. METHODS: To clarify whether neuroinflammation influences Parkinson's disease pathogenesis, we developed: (i) a 'double-hit' approach in C57BL/6 naive mice where peripherally administered lipopolysaccharides were followed by intracerebroventricular injection of an inactive oligomer dose; (ii) a transgenic 'double-hit' model where lipopolysaccharides were given to A53T α-synuclein transgenic Parkinson's disease mice. RESULTS: Lipopolysaccharides induced a long-lasting neuroinflammatory response which facilitated the detrimental cognitive activities of oligomers. LPS-activated microglia and astrocytes responded differently to the oligomers with microglia activating further and acquiring a pro-inflammatory M1 phenotype, while astrocytes atrophied. In the transgenic 'double-hit' A53T mouse model, lipopolysaccharides aggravated cognitive deficits and increased microgliosis. Again, astrocytes responded differently to the double challenge. These findings indicate that peripherally induced neuroinflammation potentiates the α-synuclein oligomer's actions and aggravates cognitive deficits in A53T mice. CONCLUSIONS: The fine management of both peripheral and central inflammation may offer a promising therapeutic approach to prevent or slow down some behavioural aspects in α-synucleinopathies.