Mitophagy Regulated by the PINK1-Parkin Pathway

Mitochondria play key roles in the cellular metabolism of lipids and iron as well as in cell death signaling. Mitochondrial dysregulation produces reactive oxygen species (ROS), which results in oxidative stress. Moreover, the accumulation of damaged mitochondria leads to cell death and tissue dysfunction. Mitochondrial maintenance involves mitophagy, a selective autophagy process that removes abnormal mitochondria. Parkinson’s disease (PD) is a movement disorder caused by the specific loss of dopaminergic neurons in the substantia nigra of the midbrain. Two genes implicated in PD, PINK1 and Parkin, regulate mitophagy in cultured cells. Reduction of the ΔΨm leads to activation of PINK1, which stimulates the recruitment of Parkin to the mitochondrial outer membrane of damaged mitochondria and activates Parkin’s ubiquitin-ligase activity. Activated mitochondrial Parkin leads to the ubiquitination of mitochondrial proteins and subsequent mitophagy. This elaborate molecular mechanism was recently uncovered and the findings demonstrate the physiological and pathological roles of the PINK1-Parkin pathway. Here, we review these key findings on the molecular mechanism and ideas relevant to neurodegeneration caused by dysregulation of the PINK1-Parkin pathway

Diagnosis of Oriental medicine in Dog and Cat

It is not easy to say that it is scientific clearly though in the Oriental medicine, there is a technique peculiar from the diagnosis to treatment. It is a development phase, and it is applied similar to the application to man though the Oriental medicine is being applied by the animal. This time, it explained the feature of an Oriental medicine disease in the dog and the cat. The method is the same as the method to do by the artery of the wrist that man has though Pulls with the groin artery is done in the dog and the cat. Moreover, the respiratory organ can be diagnosed,and because an inter-esting reaction to control it this time was admitted, it reports. On the other hand, it has a lot of volume of information though neither Eye and Pulls diagnosis are made a science. In addition, it reports on the diagnosis of the convulsion in the Oriental medicine this time. Moreover, this report is convinced of it that it is relate about the nervous system and pressure, and can do clarification scientific the Oriental medicine in the future

Impact of behavioral/developmental disorders comorbid with conduct disorder

Aims: The aim of the present study was to verify the comorbidity of conduct disorder (CD) and behavioral/developmental disorders in children and adolescents, and to examine the traits of CD comorbid with them. Methods: Subjects were 64 children (60 boys, four girls) who were resident at three institutions for delinquent children or who were conduct-disordered outpatients of a university hospital aged under 18 years. A diagnostic interview was carried out by experienced child psychiatrists and the intelligence score and the Adverse Childhood Experiences score were measured by a licensed psychologist. Results: A total of 57 children were diagnosed as having CD, of whom 26 (45.6%) were diagnosed with comorbid attention-deficit-hyperactivity disorder (ADHD), 12 were diagnosed with comorbid pervasive developmental disorder (PDD, 21,1%), and 19 (33.3%) had no comorbidity of either disorder. Six children (18.8% of CD comorbid with ADHD) met the criteria for both ADHD and PDD. The group with comorbid PDD was significantly younger at onset (F = 6.51, P = 0.003) and included unsocialized type more frequently (KH2 = 6.66, P = 0.036) compared with the other two groups. Conclusions: Clinicians should be aware that not only ADHD but also PDD may be comorbid with CD. Establishment of the correct diagnosis is important because recognizing the presence of PDD will enable us to provide appropriate treatment and guidance, which may improve prognosis.ArticlePSYCHIATRY AND CLINICAL NEUROSCIENCES. 63(6):762-768 (2009)journal articl

In situハイブリダイゼーションによる子宮頸部上皮性病変への16, 18ヒト乳頭腫ウイルスの組み込みの検出

高感度 in situ ハイブリゼーション（ISH）法と高感度 PCR 法を用いて子宮頸部扁平上皮病変と腺病変での16型と18型のヒト乳頭種ウイルス感染頻度検索し、核への組み込みの頻度を ISH 法で決定した。16, 18型は PCR と ISH でともに、扁平上皮系病変のグレードが高まるにつれて感染頻度が上がった。浸潤扁平上皮癌のすべての例で ISH で組み込み型を示し、CIN1 の全てでエピソーム型を示した。腺系病変では PCR でも ISH でも16型より18型が多く検出され、そのほぼすべてが組み込み型だった。CIN2ではエピソーム型が多くCIN3では組み込み型が多かった。これらから16, 18型の核への組み込みは扁平上皮病変でも腺病変でも癌の初期に現れる変化、あるいは癌への進展を強く示唆する所見と考えられた。Highly sensitive in situ hybridization (ISH) and highly sensitive PCR methods were used to determine the infection of HPV type 16 (HPV 16) and type 18 (HPV 18) and the integration of them into the cells of squamous and glandular lesions of the uterine cervix. The frequency of HPV infection detected by ISH and PCR increased with progression of squamous lesions. All cases of ICC showed the integrated pattern of positive signals with ISH and all positive cases in CIN1 showed the episomal pattern. In CIN2 episomal patterns were more frequent than integrated pattern and in CIN3 integrated pattern were more frequent. Glandular lesions showed a greater frequency of HPV 18 than HPV 16 on nested PCR and ISH, and almost all of ISH-positive cases showed the integrated pattern. These data suggested that integration of HPV 16 and 18 is required for carcinogenesis in both squamous cell carcinoma and adenocarcinoma of the uterine cervix

Quantitative Assessment of Eye Phenotypes for Functional Genetic Studies Using Drosophila melanogaster

About two-thirds of the vital genes in the Drosophila genome are involved in eye development, making the fly eye an excellent genetic system to study cellular function and development, neurodevelopment/degeneration, and complex diseases such as cancer and diabetes. We developed a novel computational method, implemented as Flynotyper software (http://flynotyper.sourceforge.net), to quantitatively assess the morphological defects in the Drosophila eye resulting from genetic alterations affecting basic cellular and developmental processes. Flynotyper utilizes a series of image processing operations to automatically detect the fly eye and the individual ommatidium, and calculates a phenotypic score as a measure of the disorderliness of ommatidial arrangement in the fly eye. As a proof of principle, we tested our method by analyzing the defects due to eye-specific knockdown of Drosophila orthologs of 12 neurodevelopmental genes to accurately document differential sensitivities of these genes to dosage alteration. We also evaluated eye images from six independent studies assessing the effect of overexpression of repeats, candidates from peptide library screens, and modifiers of neurotoxicity and developmental processes on eye morphology, and show strong concordance with the original assessment. We further demonstrate the utility of this method by analyzing 16 modifiers of sine oculis obtained from two genome-wide deficiency screens of Drosophila and accurately quantifying the effect of its enhancers and suppressors during eye development. Our method will complement existing assays for eye phenotypes and increase the accuracy of studies that use fly eyes for functional evaluation of genes and genetic interactions

Parkinson’s disease-associated iPLA2-VIA/PLA2G6 regulates neuronal functions and α-synuclein stability through membrane remodeling

Mutations in the iPLA2-VIA/PLA2G6 gene are responsible for PARK14-linked Parkinson’s disease (PD) with α-synucleinopathy. However, it is unclear how iPLA2-VIA mutations lead to α-synuclein (α-Syn) aggregation and dopaminergic (DA) neurodegeneration. Here, we report that iPLA2-VIA–deficient Drosophila exhibits defects in neurotransmission during early developmental stages and progressive cell loss throughout the brain, including degeneration of the DA neurons. Lipid analysis of brain tissues reveals that the acyl-chain length of phospholipids is shortened by iPLA2-VIA loss, which causes endoplasmic reticulum (ER) stress through membrane lipid disequilibrium. The introduction of wild-type human iPLA2-VIA or the mitochondria–ER contact site-resident protein C19orf12 in iPLA2-VIA–deficient flies rescues the phenotypes associated with altered lipid composition, ER stress, and DA neurodegeneration, whereas the introduction of a disease-associated missense mutant, iPLA2-VIA A80T, fails to suppress these phenotypes. The acceleration of α-Syn aggregation by iPLA2-VIA loss is suppressed by the administration of linoleic acid, correcting the brain lipid composition. Our findings suggest that membrane remodeling by iPLA2-VIA is required for the survival of DA neurons and α-Syn stability

The Loss of PGAM5 Suppresses the Mitochondrial Degeneration Caused by Inactivation of PINK1 in Drosophila

PTEN-induced kinase 1 (PINK1), which is required for mitochondrial homeostasis, is a gene product responsible for early-onset Parkinson's disease (PD). Another early onset PD gene product, Parkin, has been suggested to function downstream of the PINK1 signalling pathway based on genetic studies in Drosophila. PINK1 is a serine/threonine kinase with a predicted mitochondrial target sequence and a probable transmembrane domain at the N-terminus, while Parkin is a RING-finger protein with ubiquitin-ligase (E3) activity. However, how PINK1 and Parkin regulate mitochondrial activity is largely unknown. To explore the molecular mechanism underlying the interaction between PINK1 and Parkin, we biochemically purified PINK1-binding proteins from human cultured cells and screened the genes encoding these binding proteins using Drosophila PINK1 (dPINK1) models to isolate a molecule(s) involved in the PINK1 pathology. Here we report that a PINK1-binding mitochondrial protein, PGAM5, modulates the PINK1 pathway. Loss of Drosophila PGAM5 (dPGAM5) can suppress the muscle degeneration, motor defects, and shorter lifespan that result from dPINK1 inactivation and that can be attributed to mitochondrial degeneration. However, dPGAM5 inactivation fails to modulate the phenotypes of parkin mutant flies. Conversely, ectopic expression of dPGAM5 exacerbated the dPINK1 and Drosophila parkin (dParkin) phenotypes. These results suggest that PGAM5 negatively regulates the PINK1 pathway related to maintenance of the mitochondria and, furthermore, that PGAM5 acts between PINK1 and Parkin, or functions independently of Parkin downstream of PINK1