Parkinson's disease (PD) is the second most common neurodegenerative disorder. Despite intense investigations, no effective therapy is available to stop its onset or halt its progression. The present study evaluates the ability of peptide corresponding to the NF-B essential modifier-binding domain (NBD) of I B kinase ␣ (IKK␣) or IKK to prevent nigrostriatal degeneration in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of PD and establish a role for NF-B in human parkinsonism. First, we found that NF-B was activated within the substantia nigra pars compacta of PD patients and MPTP-intoxicated mice. However, i.p. injection of wild-type NBD peptide reduced nigral activation of NF-B, suppressed nigral microglial activation, protected both the nigrostriatal axis and neurotransmitters, and improved motor functions in MPTP-intoxicated mice. These findings were specific because mutated NBD peptide had no effect. We conclude that selective inhibition of NF-B activation by NBD peptide may be of therapeutic benefit for PD patients.MPTP ͉ NBD peptides ͉ neurodegeneration
There is a paucity of community-based epidemiological data on nonalcoholic fatty liver (NAFL) among nonaffluent populations in developing countries. Available studies are radiological and/or biochemical and lack histological assessment, limiting their strength. We conducted a prospective epidemiological study comprising a 1:3 subsample of all adult (>18 years) inhabitants of a rural administrative unit of West Bengal, India. Subjects positive for hepatitis B virus and/or hepatitis C virus infection and consuming any amount of alcohol were excluded. Diagnosis of NAFL was by dual radiological screening protocol consisting of ultrasonographic and computed tomographic examination of the liver. Transient elastographic examination and liver biopsy were performed in a subset to identify significant liver disease. The risk factors of having NAFL were analyzed. A total of 1,911 individuals were analyzed, 7% of whom were overweight and 11% of whom had abdominal obesity. The prevalence of NAFL, NAFL with elevated alanine aminotransferase, and cryptogenic cirrhosis was 8.7%, 2.3%, and 0.2%, respectively. Seventy-five percent of NAFL subjects had a body mass index (BMI) <25 kg/m 2 , and 54% were neither overweight nor had abdominal obesity. The subjects with the highest risk of having NAFL were those with a BMI >25 kg/m 2 (odds ratio 4.3, 95% confidence interval 1.6-11.5). Abdominal obesity, dysglycemia (fasting plasma glucose >100 mg/dL or elevated homeostatic model assessment of insulin resistance), and higher income were the other risk factors. Even having a normal BMI (18.5-24.9 kg/m 2 ) was associated with a 2-fold increased risk of NAFL versus those with a BMI <18.5 kg/m 2
Parkinson’s disease (PD) is a progressive neurodegenerative disease in the elderly, and no cure or disease-modifying therapies exist. Several lines of evidence suggest that mitochondrial dysfunction and oxidative stress have a central role in the dopaminergic neurodegeneration of PD. In this context, mitochondria-targeted therapies that improve mitochondrial function may have great promise in the prevention and treatment of PD. In this review, we discuss the recent developments in mitochondria-targeted antioxidants and their potential beneficial effects as a therapy for ameliorating mitochondrial dysfunction in PD.
Parkinson's disease (PD) is second only to Alzheimer's disease as the most common devastating human neurodegenerative disorder. Despite intense investigation, no interdictive therapy is available for PD. We investigated whether simvastatin, a Food and Drug Administration-approved cholesterol-lowering drug, could protect against nigrostriatal degeneration after 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine ( Similarly, pravastatin, another cholesterol-lowering drug, suppressed microglial inflammatory responses and protected dopaminergic neurons in MPTP-intoxicated mice, but at levels less than simvastatin. Furthermore, both the statins administered 2 d after initiation of the disease were still capable of inhibiting the demise of dopaminergic neurons and concomitant loss of neurotransmitters, suggesting that statins are capable of slowing down the progression of neuronal loss in the MPTP mouse model. Therefore, we conclude that statins may be of therapeutic benefit for PD patients.
CD36 is a scavenger receptor that binds multiple ligands, including phosphatidyl serine (PS). Although CD36 -mice do not have a bleeding diathesis, we show here that they do have significantly prolonged thrombotic occlusion times in response to FeCl 3 -induced vascular injury. Because cell-derived microparticles (MPs) are generated in response to vascular injury and circulate in patients with prothrombotic diseases, we hypothesized that PS exposed on their surfaces could be an endogenous CD36 ligand that transmits an activating signal to platelets. We found that MPs prepared from human ECs, monocytes, or platelets or isolated from blood of normal subjects bound to platelets. Binding was not observed with platelets from CD36 -donors and was inhibited by an anti-CD36 antibody or by blockade of exposed PS by annexin V or anti-PS IgM. Preincubation of platelets with MPs led to CD36-dependent augmentation of platelet activation in response to low doses of ADP, as assessed by measuring α 2b β 3 activation, P-selectin expression, and aggregation. Immunofluorescence confocal microscopy of murine carotid thrombi from CD36 -mice showed a significant decrement in endothelial antigen accumulation, which suggests that CD36 plays a role in MP recruitment into thrombi. These results provide what we believe to be a novel role for CD36 in thrombosis.
The objective of this study was to assess the neuroprotective effects of a mitochondria-targeted antioxidant, Mito-Q10, the coenzyme-Q analog attached to a triphenylphosphonium cation that targets the antioxidant to mitochondria, in experimental models of Parkinson’s disease (PD). Primary mesencephalic neuronal cells and cultured dopaminergic cells were treated with 1-methyl-4-phenylpyridinium (MPP+), an active metabolite of the neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP), and mice were used for testing the efficacy of Mito-Q10. MPP+ treatment caused a dose-dependent loss of tyrosine hydroxylase and membrane potential and an increase in caspase-3 activation in dopaminergic cells, which were reversed by Mito-Q10. MPTP treatment induced a loss of striatal dopamine and its metabolites, inactivation of mitochondrial aconitase in the substantia nigra, and a loss of locomotor activity in mice. Treatment with Mito-Q10 significantly inhibited both MPP+- and MPTP-induced neurotoxicity in cell culture and mouse models. Collectively, these results indicate that mitochondrial targeting of antioxidants is a promising neuroprotective strategy in this preclinical mouse model of PD.
We recently demonstrated that protein kinase C␦ (PKC␦), an important member of the novel PKC family, is a key oxidative stresssensitive kinase that can be activated by caspase-3-dependent proteolytic cleavage to induce dopaminergic neuronal cell death. We now report a novel association between ␣-synuclein (␣syn), a protein associated with the pathogenesis of Parkinson's disease, and PKC␦, in which ␣syn negatively modulates the p300-and nuclear factor-B (NFB)-dependent transactivation to downregulate proapoptotic kinase PKC␦ expression and thereby protects against apoptosis in dopaminergic neuronal cells. Stable expression of human wild-type ␣syn at physiological levels in dopaminergic neuronal cells resulted in an isoform-dependent transcriptional suppression of PKC␦ expression without changes in the stability of mRNA and protein or DNA methylation. The reduction in PKC␦ transcription was mediated, in part, through the suppression of constitutive NFB activity targeted at two proximal PKC␦ promoter B sites. This occurred independently of NFB/IB␣ (inhibitor of B␣) nuclear translocation but was associated with decreased NFB-p65 acetylation. Also, ␣syn reduced p300 levels and its HAT (histone acetyltransferase) activity, thereby contributing to diminished PKC␦ transactivation. Importantly, reduced PKC␦ and p300 expression also were observed within nigral dopaminergic neurons in ␣syn-transgenic mice. These findings expand the role of ␣syn in neuroprotection by modulating the expression of the key proapoptotic kinase PKC␦ in dopaminergic neurons.
Mitochondrial and autophagic dysfunction as well as neuroinflammation are involved in the pathophysiology of Parkinson's disease (PD). We hypothesized that targeting the mitochondrial pyruvate carrier (MPC), a key controller of cellular metabolism that influences mTOR (mammalian target of rapamycin) activation, might attenuate neurodegeneration of nigral dopaminergic neurons in animal models of PD. To test this, we used MSDC-0160, a compound that specifically targets MPC, to reduce its activity. MSDC-0160 protected against 1-methyl-4-phenylpyridinium (MPP) insult in murine and cultured human midbrain dopamine neurons and in an α-synuclein-based Caenorhabditis elegans model. In 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated mice, MSDC-0160 improved locomotor behavior, increased survival of nigral dopaminergic neurons, boosted striatal dopamine levels, and reduced neuroinflammation. Long-term targeting of MPC preserved motor function, rescued the nigrostriatal pathway, and reduced neuroinflammation in the slowly progressive Engrailed1 (En1) genetic mouse model of PD. Targeting MPC in multiple models resulted in modulation of mitochondrial function and mTOR signaling, with normalization of autophagy and a reduction in glial cell activation. Our work demonstrates that changes in metabolic signaling resulting from targeting MPC were neuroprotective and anti-inflammatory in several PD models, suggesting that MPC may be a useful therapeutic target in PD.
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