Mie Hirohata

Non-steroidal anti-inflammatory drugs have anti-amyloidogenic effects for Alzheimer's β-amyloid fibrils in vitro

The pathogenesis of Alzheimers disease (AD) is characterized by cerebral deposits of amyloid beta-peptides (A beta) and neurofibrillary tangles which are surrounded by inflammatory cells. Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of developing AD and delays the onset of the disease. In the present study, we used fluorescence spectroscopy with thioflavin T and electron microscopy to examine the effects of NSAIDs such as ibuprofen, aspirin, meclofenamic acid sodium salt, diclofenac sodium salt, ketoprofen, flurbiprofen, naproxen, sulindac sulfide and indomethacin on the formation, extension, and destabilization of beta-amyloid fibrils (fA beta) at pH 7.5 at 37 degrees C in vitro. All examined NSAIDs dose-dependently inhibited formation of fA beta from fresh A beta(1-40) and A beta(1-42), as well as their extension. Moreover, these NSAIDs dose-dependently destabilized preformed fA betas. The overall activity of the molecules examined was in the following order: ibuprofen approximately sulindac sulfide >or= meclofenamic acid sodium salt>aspirin approximately ketoprofen >or= flurbiprofen approximately diclofenac sodium salt>naproxen approximately indomethacin. Although the mechanisms by which these NSAIDs inhibit fA beta formation from A beta, and destabilize preformed fA beta in vitro are still unclear, NSAIDs may be promising for the prevention and treatment of AD.

Non-steroidal anti-inflammatory drugs have potent anti-fibrillogenic and fibril-destabilizing effects for α-synuclein fibrils in vitro

The aggregation of alpha-synuclein (alphaS) in the brain has been implicated as a critical step in the development of Lewy body diseases (LBD) [Parkinsons disease (PD)/dementia with Lewy bodies (DLB)] and multiple system atrophy (MSA). The involvement of neuroinflammation and microglial activation has been emphasized in the pathogenesis of PD. Recent epidemiological studies have revealed that therapeutic use of non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of developing PD. Here, we examined the effects of NSAIDs, such as ibuprofen, aspirin, acetaminophen, meclofenamic acid sodium salt, sulindac sulfide, ketoprofen, flurbiprofen, diclofenac sodium salt, naproxen, and indomethacin, on the formation and destabilization of alphaS fibrils (falphaS) at pH 7.5 and 37 degrees C in vitro, using fluorescence spectroscopy with thioflavin S and electron microscopy. All examined NSAIDs, except for naproxen and indomethacin, inhibited the formation of falphaS in a dose-dependent manner. Moreover, these molecules dose-dependently destabilized preformed falphaS. The overall activity was in the order: ibuprofen approximately aspirin approximately acetaminophen approximately meclofenamic acid sodium salt approximately sulindac sulfide>ketoprofen approximately flurbiprofen approximately diclofenac sodium salt>naproxen approximately indomethacin. These findings indicate that NSAIDs could be key molecules for the development of therapeutic or preventive agents for LBD and MSA.

β-Synuclein Assembly as a Therapeutic Target of Parkinsons Disease and Related Disorders

Lewy bodies (LBs) and Lewy neurites (LNs) in the brain constitute the main histopathological features of Parkinsons disease (PD) and dementia with Lewy bodies (DLB), and are comprised of amyloid-like fibrils composed of a small protein (∼14 kDa) named alpha-synuclein (αS). As the aggregation of αS in the brain has been implicated as a critical step in the development of the diseases, the current search for disease-modifying drugs is focused on modification of the process of αS deposition in the brain. In this article, the recent developments on the molecules that inhibit the formation of α-synuclein fibrils (fαS) as well as the oligomerization of αS are reviewed. Recently, various compounds such as curcumin, nicotine and wine-related polyphenols have been reported to inhibit the formation of fαS, and to destabilize preformed fαS at pH 7.5 at 37°C in vitro. Although the mechanisms by which these compounds inhibit fαS formation from fαS, and destabilize preformed fαS are still unclear, they could be key molecules for the development of preventives and therapeutics for PD and other α-synucleinopathies.

Anti-fibrillogenic and fibril-destabilizing activities of anti-parkinsonian agents for α-synuclein fibrils in vitro

The aggregation of alpha‐synuclein (αS) in the brain has been implicated as a critical step in the development of Lewy body diseases (LBD) and multiple system atrophy (MSA). Among the antioxidant strategies proposed, increasing evidence points to the possibility of achieving neuroprotection by dopamine agonists, as well as monoamine oxidase B inhibitors. We showed previously that the anti‐Parkinsonian agents dose‐dependently inhibited β‐amyloid fibrils (fAβ)(1–40) and fAβ(1–42) formation as well as destabilized preformed fAβs. Using fluorescence spectroscopy with thioflavin S, electron microscopy, and atomic force microscopy, we examined the effects of anti‐Parkinsonian agents, selegiline, dopamine, pergolide, bromocriptine, and trihexyphenidyl on the formation of αS fibrils (fαS) and on preformed fαS. All molecules except for trihexyphenidyl, dose‐dependently inhibited the formation of fαS. Moreover, these molecules dose‐dependently destabilized preformed fαS. The overall activity of the molecules examined was in the order of: selegiline = dopamine > pergolide > bromocriptine. These agents and other compounds related structurally could be key molecules for the development of therapeutics for LBD and MSA.

Clinical features of non‐hypertensive lobar intracerebral hemorrhage related to cerebral amyloid angiopathy

Background and purpose: The present study aims to clarify the clinical features of non‐hypertensive cerebral amyloid angiopathy‐related lobar intracerebral hemorrhage (CAA‐L‐ICH).

Effects of sex hormones on Alzheimer's disease-associated β-amyloid oligomer formation in vitro.

The folding of amyloid β-protein (Aβ) into oligomeric, protofibrillar, and fibrillar assemblies is hypothesized to be the key pathogenic event in Alzheimers disease (AD), with oligomeric assemblies thought to be the most neurotoxic. Inhibitors of oligomer formation, therefore, could be valuable therapeutics for patients with AD. Epidemiological studies have indicated that estrogen therapy reduces the risk of developing AD in women. Here, we examined the effects of estrogen (estrone (E1), estradiol (E2), and estriol (E3)) and related sexual steroids (androstenedione (AND) and testosterone (TES)) on the in vitro oligomer formation of Aβ(1-40) and Aβ(1-42) using a method of photo-induced cross-linking of unmodified proteins (PICUP) and electron microscopic studies. Estrogens (E1, E2, and E3) inhibited low-order Aβ oligomer formation, and among them, E3 had the strongest in vitro activity. Estrogen could be a potential therapeutic agent to prevent or delay AD progression, and further understanding of the fact that these very similar molecules have different anti-oligomeric effects would contribute to the development of new agents.

Anti-fibrillogenic and fibril-destabilizing activity of nicotine in vitro: implications for the prevention and therapeutics of Lewy body diseases.

The aggregation of alpha-synuclein (alphaS) has been implicated as a critical step in the development of Lewy body diseases (LBD) and multiple system atrophy (MSA). Both retrospective and prospective epidemiological studies have consistently demonstrated an inverse association between cigarette smoking and Parkinsons disease (PD). We used fluorescence spectroscopy with thioflavin S, electron microscopy and atomic force microscopy to examine the effects of nicotine, pyridine, and N-methylpyrrolidine on the formation of alphaS fibrils (f alphaS) from wild-type alphaS (alphaS (WT)) and A53T mutant alphaS (A53T) and on preformed f alpha Ss. Nicotine dose-dependently inhibited the f alphaS formation from both alphaS (WT) and A53T. Moreover, nicotine dose-dependently destabilized preformed f alpha Ss. These effects of nicotine were similar to those of N-methylpyrrolidine. The anti-fibrillogenic activity of nicotine may be exerted not only by the inhibition of f alphaS formation but also by the destabilization of preformed f alphaS. Additionally, this effect may be attributed to N-methylpyrrolidine moieties of nicotine.

Non-Steroidal Anti-Inflammatory Drugs as Anti-Amyloidogenic Compounds

Amyloidosis is a clinical disorder caused by deposition of proteins that abnormally self-assemble into insoluble fibrils and impair organ function. More than 20 unrelated precursor proteins lose their native structure and misfold, leading to the formation of amyloid fibrils. The latter share cross-beta core structure in vivo and in vitro and gain abnormal functions. Local amyloid deposition occurs in the central nervous system in Alzheimers disease (AD) and cerebral amyloid angiopathy. AD is the most common form of neurodegenerative disorder, with dementia in the elderly as well as dementia with Lewy bodies (DLB). Extracellular deposition of amyloid beta-peptide (Abeta) has been implicated as a critical step in the pathogenesis of AD. Involvement of neuroinflammation and microglial activation has been emphasized in the AD brain. Recent epidemiological studies have shown that long-term therapeutic use of non-steroidal anti-inflammatory drugs (NSAIDs) reduces the risk of developing AD and delayed the onset of AD. We review epidemiological studies of anti-AD effects of NSAIDs, experimental studies of anti-amyloidogenic as well as anti-inflammatory effects of NSAIDs, and recent clinical trials for AD with NSAIDs. We refer to the anti-fibrillogenic and fibril-destabilizing activities of NSAIDs for other proteins that can aggregate and form amyloid-like fibrils, including alpha-synuclein in DLB. The anti-amyloidogenic properties of some NSAIDs provide new insights for future therapeutic and preventative opportunities for AD and other amyloidoses, and protein-misfolding disorders.

Vitamin A has Anti-Oligomerization Effects on Amyloid-β In Vitro

Inhibition of amyloid-β (Aβ) aggregation is an attractive therapeutic strategy for treatment of Alzheimers disease (AD). We previously reported that vitamin A and β-carotene inhibit fibrillation of Aβ40 and Aβ42 (Ono et al, 2004, Exp Neurol). In this study, we firstly examined the effects of vitamin A (retinoic acid, retinol, and retinal), β-carotene, vitamin B2, vitamin B6, vitamin C, vitamin E, coenzyme Q10, and α-lipoic acid on oligomerization of Aβ40 and Aβ42 in vitro; vitamin A and β-carotene dose-dependently inhibited oligomerization of Aβ40 and Aβ42. Furthermore, retinoic acid decreased cellular toxicity by inhibition of Aβ42 oligomerization. Second, we analyzed how vitamin A inhibits Aβ aggregation by using fluorescence spectroscopy and thioflavin T assay with two Aβ fragments, Aβ1-16 and Aβ25-35. A fluorescence peak of retinoic acid was greatly restrained in the presence of Aβ25-35, and retinoic acid inhibited aggregation of Aβ25-35, but not of Aβ1-16, which suggest the specific binding of retinoic acid to the C-terminal portion of Aβ. Thus, vitamin A and β-carotene might be key molecules for prevention of AD.

Hereditary inclusion body myopathy with a novel mutation in the GNE gene associated with proximal leg weakness and necrotizing myopathy

Sir, Autosomal recessive hereditary inclusion body myopathy (HIBM) is a muscular disorder characterized by early adult-onset weakness beginning in the distal muscles of the lower limbs with relative sparing of the quadriceps [1], and is frequently associated with mutations in the UDP-N-acetylglucosamine 2-epimerase/ N-acetylmannosamine kinase gene (GNE) on chromosome 9p12-p13 [2]. The presence of rimmed vacuoles on muscle biopsy is the most important finding for diagnosis of this disorder. A 28-year-old man developed progressive muscle weakness of the legs. He had no myalgia, but often complained of muscle cramp. At age 29, neurological examination demonstrated weakness of the bilateral iliopsoas and hamstrings with sparing of the quadriceps. The serum creatine kinase level was elevated [2224 (normal <306) IU/l]. Biopsy of the biceps femoris muscle showed many necrotic and regenerating fibers (Fig. 1a). Treatment with methyl prednisolone pulse therapy, oral prednisolone (60 mg/day), oral cyclophosphamide, or oral cyclosporin did not improve muscle weakness. At age 31, fat-suppressed MRI demonstrated increased signals in the thighs suggesting muscle inflammation [3]. The second biopsy from the right quadriceps femoris muscle showed some necrotic and regenerating fibers. Despite intravenous immunoglobulin therapy (0.4 g/ kg · 5 days) under a diagnosis of steroidrefractory chronic polymyositis, the lower limb weakness progressed. The third biopsy from the tibialis anterior muscle demonstrated numerous rimmed vacuoles with some necrotic fibers and sparse regenerating fibers (Fig. 1b); immunohistochemically, the muscle fibers showed partial expression of major histocompatibility complex class Imoleculewith infiltration of a few CD8+ T cells. After obtaining informed consent, we isolated genomic DNA from the whole blood sample of the patient and his parents. Analysis of eleven coding exons (exons 2– 12) of GNE [4] demonstrated compound heterozygous mutations changing GAT (aspartic acid) to GTT (valine) at codon 176 (D176V) on exon 3, and CCT (proline) to CAT (histidine) at codon 511 (P511H) on exon 9. The patient’s father carried a D176V mutation, and his mother had a P511H mutation. Although the D176V mutation was previously reported [5], the P511H mutation was novel. Several aspects of the clinicopathological features in our patient were similar to acquired inflammatory myopathy. A variety of mutations in the GNE gene showing atypical phenotypes have been identified, including sporadic occurrence [6], muscle inflammation [7], and absence of distal weakness [5]. Although theGNEmutations would lead to changes in the activities of UDP-N-acetylglucosamine 2-epimerase or N-acetylmannosamine kinase and to a decrease in sialylation in muscle [8], pathomechanisms underlying the muscle involvement remain unclear, and the variations in myopathic features of HIBM can not be explained simply by the sites of the GNEmutations.Mutations associatedwith proximal leg weakness included V572L/ V572L, C303V/V572L, and C13S/D176V [5,6]; however, distal myopathy was also reported in HIBM with the V572L/V572L mutation [6]. Our patient with HIBM presented with atypical features including muscle fiber necrosis, although a characteristic feature ofHIBM, i.e., sparing of the quadriceps [1], was still present. It is suggested that a subset of HIBM patients present with a clinical phenotype similar to acquired inflammatory myopathy, although the phenotype–genotype relationship remains to be determined.