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"Yokukansan (...)" is one of Japanese Kampo prescriptions, which has been clinically treated for the patients with behavioral and psychological symptoms of dementia, as wells as neuropathic pain symptoms. This study investigated the effect of yokukansan on the nociceptive response to 0.5% formalin. Oral administration of Yokukansan significantly inhibited 0.5% formalin-induced nociceptive responses in mice. Intraperitoneal pretreatment with naloxone hydrochloride, an opioid receptor antagonist significantly antagonized the antinociceptive effects of Yokukansan. We also examined the possible involvement of spinal extracellular signal-regulated protein kinase (ERK) in Yokukansan-induced antinociception. In western blotting analysis, oral administration of Yokukansan resulted in a significant blockade of spinal ERK activation induced by 0.5% formalin. Naloxone hydrochloride significantly reversed the blockage of spinal ERK activation induced by Yokukansan. These results suggest that oral administration of Yokukansan-induced antinociceptive effect and blockage of spinal ERK activation may be triggered by activation of opioid receptors. [ABSTRACT FROM AUTHOR]

Parkinson's disease (PD) is the second most common neurodegenerative disease. The majority of PD cases are sporadic; however, the discovery of genes linked to rare familial forms of the disease has provided crucial insight into the molecular mechanisms of disease pathogenesis. PINK1 and PARKIN are causal genes for hereditary (i. e., autosomal recessive) early-onset PD. In 2010, intense efforts by our laboratory and several other groups have revealed the mechanism by which PINK1 and Parkin maintain mitochondrial integrity. The essence of the model is that PINK1 is rapidly and constitutively degraded under steady-state conditions in a mitochondrial membrane potential (ΔΨm)-dependent manner and that a loss in ΔΨm stabilizes PINK1 on damaged mitochondria, and then recruits Parkin from the cytosol to the mitochondria for proteasomal and autophagic degradation. Recently, a pharmacological approach using various chemical reagents such as valinomycin, nigericin, 2-deoxy-D-glucose, and oligomycin demonstrated that Parkin recruitment is voltage-dependent and independent of changes in ATP or pH. Moreover, F1-ATPase inhibitor azide recruited Parkin to the mitochondria only in ρ 0 cells, which lack mtDNA and a functional electron transport chain. These results confirm that ΔΨm is the most important factor for the discrimination of damaged mitochondria from their healthy counterparts. Here we provide an overview of how PINK1 and Parkin identify, label and clear damaged/depolarized mitochondria, focusing on the role of mitochondrial autophagy (mitophagy).

Parkinson disease (PD), is a movement disorder pathologically characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Although the inherited forms of PD account for only 5 to 10% of PD cases, the identification of gene mutations in the genes implicated in familial PD in the past 10 years, including the findings regarding the a-synuclein, Parkin, ubiquitin-C-terminal hydrolase-L1 (UCH-L1), PINK1, DJ-1 and the ATP13A2 genes, has advanced understanding of the molecular mechanisms in each case of genetic PD. Most familial forms of PD develop at an early onset. However, recent identification of the leucine-rich repeat kinase (LRRK) 2 gene for a late-onset PD, the clinicopathological feature of which closely resembles that of sporadic PD, is expected to enable the clarification of the underlying causes of general PD. Recent studies on the physiological and pathological functions of these identified gene products have revealed overlapping pathogenetic pathways. The common features of these aberrant pathways are impaired protein degradation/quality control, mitochondrial dysfunction, and altered vesicle transport. Several attempts have been made towards developing molecular-targeted therapies directed against mitochondria (e.g., antioxidants, permeability transition pore modulators, and mitochondrial biogenesis stimulators), protein quality control and vesicle transport (e.g., gene silencing, immunization of asynuclein, and protofibril-destabilizing reagents). To ensure the successful implementation of such strategies, it is important to understand the events occuring at an early stage of PD. Further, studies using mammalian PD models for pharmacological analysis combined with studies employing lower organisms for genetic analyses such as worm, fly, and yeast will be helpful to determine effective prevention and treatment strategies for PD, which will replace the conventional symptomatic treatments for PD.

Parkinson's disease (PD) is the second most common neurodegenerative disease. It is associated with the degeneration of dopaminergic neurons in the substantia nigra pars compacta and other areas of the brain. The pathology of PD is characterized by the accumulation of a cytoplasmic fibrillar structure, wherein alpha-synuclein is the major component. Most occurrences of PD were believed to be sporadic and associated with aging and environmental stress. However, there is now strong evidence for genetic inheritance in a small number of families. Although the pathological mechanisms of PD are still largely unknown, we present the major hypotheses and discuss the future directions of studies in this area.

Parkinson disease (PD) and dystonia are two major part of neurodegenerative disorders. The underlying cause of PD development has been considered to be a combination of genetic factors and environmental substrates. In case of dystonia, which includes primary sporadic dystonia, such as task specific dystonia, cervical dystonia and so on, are also considered to associate with unknown vulnerable genetic factors. In this paper, the clinical features and causative genes for PD and dystonia were described; especially in particular, the description of those genes associated with the PARK and DYT series were provided. Most of the identified causative genes for PD are associated with the protein degradation and cell death process via convergent mechanisms such as ubiquitin-proteasome system, mitochondrial dysfunction, oxidative stress, and lysosomal system (autophagia). On the other hand, the pathogenic mechanism for dystonia is gradually discovered to be divergent suggested by identified genes, such as torsinA, GCH1, etc, which is compatible and well understood with the divergent expression of dystonia phenotype. Another breakthroughs are required to investigate the treatment of both PD and dystonia based on the pathogenic mechanisms.

Collagenopathies with collagen VI mutations include Ullrich congenital muscular dystrophy (Ullrich's disease) and Bethlem myopathy. Patients with Ullrich's disease have generalized muscle weakness, multiple contractures of the proximal joints and hyperextensibility of the distal joints. Bethlem myopathy is characterized by the combination of proximal muscle weakness and contractures of finger, elbow, and ankle joints. We found for the first time a deficiency of collagen VI in Ullrich's disease. Furthermore, we found an abnormality of cell adhesion and abnormal regeneration or maturation in Ullrich's disease. Mutations in the genes COL6A1, COL6A2, COL6A3 are associated with Ullrich's disease and Bethlem myopathy. Bethlem myopathy is inherited in an autosomal dominant manner and Ullrich's disease usually in an autosomal recessive manner. Recently, de novo dominant mutations are reported in Ullrich's disease. We evaluated the role of nonsense-mediated mRNA decay (NMD) in Ullrich's disease that has a frameshift mutation with a premature termination codon in the COL6A2 gene causing the loss of collagen VI. The pharmacological block of NMD caused upregulation of the mutant collagen VI and partially functional extracellular matrix formation. Our results suggest that NMD inhibitors can be used as a therapeutic tool to rescue some human genetic diseases exacerbated by NMD.

From 2001 to the summer of 2002, more than 800 cases of liver damage were reported in Japan among people taking Chinese diet aids. The Japanese Ministry of Health, Labor and Welfare has recently announced that N-nitrosofenfluramine was the hepatotoxic compound contained in the diet aids based on animal experiments performed by the National Institute of Health Sciences. Although N-nitrosofenfluramine is a derivative of fenfluramine, a previously used antiobesity drug, neither pharmacologic nor toxicologic properties have been reported for N-nitroso fenfluramine. It should be noted that N-nitrosofenfluramine has two optical isomers, although it is not yet known which isomer damages the liver and other organs. The Japanese Ministry of Health, Labor and Welfare has not commented on this point. Pursuing this question, 10 types of Chinese slimming aid samples including those obtained from patients with fulminating hepatitis were analyzed by NMR, GC/MS, and a newly established HPLC method using a chiral separation column. It was found that the N-nitrosofenfluramine in all of the toxic diet aids was the (S)-isomer form. No (R)-isomer was detected. These results strongly suggest that the nitroso-compound in the diets must be prepared from pharmacologically active (S)-fenfluramine (dexfenfluramine). Thus the pharmacologic and toxicologic properties of each isomer should be investigated.

Knock-out of mammalian genes is technically troublesome and time-consuming compared to those of lower animals. RNA interference (RNAi) is a strategy of sequence-specific post-translational gene silencing, and it has been successfully applied for disruption of gene transcripts in C. elegans. Gene silencing by RNAi had not been accomplished in mammalian cells until recently, because bystander activation of DNA-dependent protein kinase (PKR) coincides to disturb gene silencing by long double-stranded RNA (dsRNA), resulting in non-specific repression of translation of many proteins. A breakthrough has come recently with a report suggesting that 20- or 21-bp duplex RNA with 2 bp 3' overhang are made by DICER protein that cleaves long dsRNA during RNAi reactions in vivo and the resultant short dsRNAs mediate RNAi. Those short dsRNAs, namely, small interference RNA (siRNA), barely activate PKR. Using synthesized 21 bp siRNA, T. Tuschl's group has challenged to establish an artificial RNAi method suitable for mammalian cells. Their report was favorable in that siRNA specifically suppressed targeted gene translation in mammalian cells during culture without activation of PKR. Recently K. Taira's group developed the vector-based siRNA expression system by which RNAi is feasible in mammalian cells. Almost all genes can be targeted by RNAi. RNAi methods require minimal time and labor; therefore, mammalian gene knockdown by RNAi will become popular in the near future.

Genomics and its technologies are being integrated into drug discovery research for three purposes; to find novel target molecules, to evaluate pharmaceutical efficacy and safety on a genome scale, and to select patients in terms of their genetic polymorphisms. Search for novel targets has been focused on G protein-coupled receptors and enzyme families such as protein kinases, protein phosphatases and proteases. The targets selected are validated in vivo with knockout mice or by administration with antibodies or antisense nucleotide derivatives. In connection with the validation, chronology on anti-platelet therapeutics through antibodies is referred to. Among genomic polymorphisms on drug response of patients, those of drug metabolizing enzymes are important for personalized medicine. Lastly, diversification of therapeutics aiming at personalized medicine is discussed in comparison with diversities of automobiles and living creatures, suggesting a novel concept, 'digital medicine'.

Light signals are converted into electrical signals by vertebrate photoreceptor cells, and the generated electrical signals are then modulated within retinal neurons and brain. During the visual transduction precesses in the photoreceptor cells, there are basically three functions. That is, (1) photoexcitation, (2) quenching of the photoexcitation, and (3) adaptation. These functions are precisely regulated by enzymatic cascade reactions. Quite recently, it was shown that rhodopsin phosphorylation occurred at different sites with different kinetics, in vivo, and this may be a control mechanism for both quenching and adaptation. Furthermore, autosmal retinitis pigmentosa (RP) with rhodopsin mutation at 296 Lys, which in the binding site of 11-cis-retinal, showed constitutive activation of guanosine 5'-triphosphate (GTP) binding protein and no rhodopsin phosphorylation by rhodopsin kinase. These observations suggest that rhodopsin phosphorylation and dephosphorylation are critical for understanding visual transduction and pathophysiology of RP.