Gene expression in the thyroarytenoid muscle in Pink1 knockout female rats
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ABSTRACT: Parkinson’s disease (PD) is a degenerative disease with prodromal pathology hypothesized to manifest in lower brainstem regions as well as within peripheral systems. Behaviorally, vocal deficits including soft monotone speech appear early and are present in 90% of PD patients. However, the pathology mediating voice deficits is unknown. The Pink1-/- rat is a mitochondrial dysfunction model of prodromal PD. In this study, we used RNA sequencing to examine gene expression within the vocal fold muscle of female Pink1-/- rats as compared to age-matched wildtype controls. Comparative gene expression profiling analysis using data obtained from the RNA-sequencing between the two genotypes (Pink1-/- and WT).
Project description:Parkinson’s disease (PD) is a progressive degenerative disease. Behaviorally, voice deficits including soft monotone speech appear early and are present in 90% of individuals with PD. However, the pathology, at the level of the nucleus ambiguus, mediating voice deficits is unknown. RNA sequencing was used to examine nucleus ambiguus differential gene expression in male Pink1-/- rats compared to age-matched wildtype controls.
Project description:Background: Parkinson’s disease (PD) is a progressive, degenerative disease with early-stage pathology hypothesized to manifest in brainstem regions. Vocal deficits, including soft monotone speech, result in significant clinical and quality of life issues and are present in 90% of PD patients; yet, the underlying pathology mediating these significant voice deficits is unknown. The Pink1-/- rat is a valid model of early-onset PD that presents with analogous vocal communication deficits (e.g. reduced loudness). Previous work shows abnormal α-synuclein protein aggregation in the periaqueductal gray (PAG), a brain region critical and necessary to the modulation of mammalian vocal behavior. In this study, we used high-throughput RNA sequencing to examine gene expression within the PAG of both male and female Pink1-/- rats as compared to age-matched wildtype controls. We used a bioinformatic approach to (1) test the hypothesis that loss of Pink1 in the PAG will influence expression of genes that interact with Pink1, (2) highlight other key genes that relate to Mendelian PD, and (3) catalog molecular targets important for the production of rat vocalizations. Results: Knockout of the Pink1 gene resulted in differentially expressed genes for both male and female rats. Pathway analysis highlighted several significant metabolic pathways. Weighted gene co-expression network analysis (WGCNA) was used to identify gene nodes and their interactions in (A) males, (B) females, and (C) combined-sexes datasets. For each analysis, within the module containing the Pink1 gene, Pink1 itself was the central node with the highest number of interactions with other genes including solute carriers, glutamate metabotropic receptors, and genes associated with protein localization. Strong connections between Pink1 and Krt2 and Hfe were found in both males and female datasets. In females a number of modules were significantly correlated with vocalization traits. Of interest, gene enrichment of the key vocal Cyan module in females showed a significant number of neuromodulatory genes including Nts, Slc6a4, Slc10a4, Ndnf, and Gpr160, that may be responsible for the modulation of rat vocalizations. The top biological pathways within the female Cyan vocal module included the regulation of membrane depolarization, indolalkylamine metabolic process, and monoamine transport. Conclusions: Overall, this work supports the premise that gene expression changes in the PAG may contribute to the vocal behavioral and deficits observed in this PD rat model. Additionally, this dataset identifies genes that represent new therapeutic targets for PD voice disorders.
Project description:Early-onset pathology and reliable disease biomarkers for diagnostics are poorly understood for progressive degenerative disorders such as Parkinson disease (PD). PD is the second most common age-related degenerative disorder. The Pink1-/- rat is a mitochondrial dysfunction model of prodromal PD. In this study, we used RNA sequencing to examine gene expression within whole blood samples of young and old Pink1-/- rats as compared to age-matched wildtype controls.
Project description:Loss of function in the PTEN-induced kinase 1 gene (Pink1) causes an early-onset, autosomal recessive form of PD. The translational Pink1-/- rat shows cranial sensorimotor deficits including: declines in ultrasonic vocalization, negative impacts on social vocal function, and alterations to thyroarytenoid muscle structure. The aim of this study was to identify differentially expressed genes using RNA-sequencing and bioinformatic analysis of the thyroarytenoid muscle of male Pink1-/- rats compared to wildtype controls. To construct gene co-expression networks and gene modules, a WGCNA was used to identify biological networks of interest including where Pink1 was a central node with interconnecting genes. Data are congruent with previous findings demonstrating changes to thyroarytenoid muscle structure. These data are consistent with the hypothesis that differences in peripheral biology may influence the early pathogenesis of vocalizations at the level of the thyroarytenoid muscle.
Project description:Parkinson’s disease (PD) is a neurodegenerative disorder with a high variability of age at onset, disease severity, and progression. This suggests that other factors, including genetic, environ-mental, or biological factors, are at play in PD. Loss of PINK1 causes a recessive form of PD and is typically fully penetrant; however, it features a wide range in disease onset, further supporting the existence of protective factors, endogenous or exogenous, to play a role. Loss of Pink1 in Drosophila melanogaster results in locomotion deficits, also observed in PINK1-related PD in humans. In flies, Pink1 deficiency induces defects in the ability to fly; none-theless, around ten percent of the mutant flies are still capable of flying, indicating that advanta-geous factors affecting penetrance also exist in flies. Here, we aimed to identify the mechanisms underlying this reduced penetrance in Pink1-deficient flies. We performed genetic screening in pink1-mutant flies to identify RNA expression alterations affecting the flying ability. The most important biological processes involved were transcription-al and translational activities, endoplasmic reticulum (ER) regulation, and flagellated movement and microtubule organization. We validated 2 ER-related proteins, zonda, and windbeutel, to positively affect the flying ability of Pink1-deficient flies. Thus, our data suggest that these pro-cesses are involved in the reduced penetrance and that influencing them may be beneficial for Pink1 deficiency.
Project description:Parkinson's disease (PD) is an adult-onset movement disorder of largely unknown etiology. We have previously shown that loss-of-function mutations of the mitochondrial protein kinase PINK1 (PTEN induced putative kinase 1) cause the recessive PARK6 variant of PD. Now we generated a PINK1 deficient mouse and observed several novel phenotypes: A progressive reduction of weight and of locomotor activity selectively for spontaneous movements occurred at old age. As in PD, abnormal dopamine levels in the aged nigrostriatal projection accompanied the reduced movements. Possibly in line with the PARK6 syndrome but in contrast to sporadic PD, a reduced lifespan, dysfunction of brainstem and sympathetic nerves, visible aggregates of M-NM-1-synuclein within Lewy bodies or nigrostriatal neurodegeneration were not present in aged PINK1-deficient mice. However, we demonstrate PINK1 mutant mice to exhibit a progressive reduction in mitochondrial preprotein import correlating with defects of core mitochondrial functions like ATP-generation and respiration. In contrast to the strong effect of PINK1 on mitochondrial dynamics in Drosophila melanogaster and in spite of reduced expression of fission factor Mtp18, we show reduced fission and increased aggregation of mitochondria only under stress in PINK1-deficient mouse neurons. Thus, aging Pink1M-bM-^HM-^R/M-bM-^HM-^R mice show increasing mitochondrial dysfunction resulting in impaired neural activity similar to PD, in absence of overt neuronal death. Transcriptome microarray data of Pink1-/- mouse brains in absence of a stressor, even at old age, show remarkably sparse dysregulations. See Gispert-S et al 2009 PLOS ONE. Factorial design comparing Pink1 knock-out mice with wild type littermates in three different tissues (striatum, midbrain, cerebellum at four different timepoints (6, 12, 14 weeks, and 18 month)
Project description:Parkinson's disease (PD) is an adult-onset movement disorder of largely unknown etiology. We have previously shown that loss-of-function mutations of the mitochondrial protein kinase PINK1 (PTEN induced putative kinase 1) cause the recessive PARK6 variant of PD. Now we generated a PINK1 deficient mouse and observed several novel phenotypes: A progressive reduction of weight and of locomotor activity selectively for spontaneous movements occurred at old age. As in PD, abnormal dopamine levels in the aged nigrostriatal projection accompanied the reduced movements. Possibly in line with the PARK6 syndrome but in contrast to sporadic PD, a reduced lifespan, dysfunction of brainstem and sympathetic nerves, visible aggregates of α-synuclein within Lewy bodies or nigrostriatal neurodegeneration were not present in aged PINK1-deficient mice. However, we demonstrate PINK1 mutant mice to exhibit a progressive reduction in mitochondrial preprotein import correlating with defects of core mitochondrial functions like ATP-generation and respiration. In contrast to the strong effect of PINK1 on mitochondrial dynamics in Drosophila melanogaster and in spite of reduced expression of fission factor Mtp18, we show reduced fission and increased aggregation of mitochondria only under stress in PINK1-deficient mouse neurons. Thus, aging Pink1−/− mice show increasing mitochondrial dysfunction resulting in impaired neural activity similar to PD, in absence of overt neuronal death. Transcriptome microarray data of Pink1-/- mouse brains in absence of a stressor, even at old age, show remarkably sparse dysregulations. See Gispert-S et al 2009 PLOS ONE.
Project description:As the second most frequent neurodegenerative disorder of old age, ParkinsonM-bM-^@M-^Ys disease (PD) can result from autosomal dominant causes like increased alpha-synuclein (SNCA) dosage, or from autosomal recessive causes like PINK1 loss-of-function. Interactions between these triggers and their potential convergence onto shared pathways are crucial to understand, but currently conflicting evidence exists. Here, we crossed previously characterized mice with A53T-SNCA overexpression and mice with PINK1 deletion to generate double mutants (DM). We studied their lifespan and behavior, together with histological and molecular anomalies at late and early ages, respectively. DM animals showed potentiated phenotypes in comparison to both single mutants (SM), with markedly reduced survival after age 450 days and strongly reduced spontaneous movements from age 3 months onwards. A considerable part of DM animals manifested progressive paralysis at ages >1 year and also exhibited protein aggregates with immunoreactivity for pSer129-SNCA, p62, and ubiquitin in spinal cord and basal brain, contrasting with absence of such features from SM. A brain proteome quantification of ubiquitination sites documented altered degradation of SNCA and the DNA-damage marker H2AX at age 18 months. Global brain transcriptome profiles and qPCR validation experiments identified many consistent transcriptional dysregulations already at age 6 weeks, which were absent from SM. The observed downregulations for Dapk1, Dcaf17, Rab42 and upregulations for Dctn5, Mrpl9, Tmem181a, Xaf1 reflect changes in ubiquitination, mitochondrial / synaptic / microtubular dynamics, and DNA damage. Thus, our study confirmed that SNCA-triggered neurotoxicity is exacerbated by the absence of PINK1, and identified a novel molecular signature that is detectable early in the course of this double pathology. Factorial design comparing Pink1 knock-out/A53T-SNCA double transgenic mice with appropriate wild-type controls (129SvEv+FVB/N) in three different tissues (cerebellum, midbrain, striatum)
Project description:The maintenance of mitochondrial homeostasis requires PTEN-induced kinase 1 (PINK1)-dependent mitophagy, and mutations in PINK1 are associated with Parkinson's disease (PD). PINK1 is also downregulated in tumor cells with PTEN mutations. However, there is limited information concerning the role of PINK1 in tissue growth and tumorigenesis. Here, we show that loss of pink1 caused multiple growth defects independent of its pathological target, Parkin. Moreover, knocking-down pink1 in muscle cells induced hyperglycemia and limited systemic organismal growth by induction of Imaginal morphogenesis protein-Late 2 (ImpL2). Similarly, disrupting PTEN activity in multiple tissues impaired systemic growth by reducing pink1 expression, resembling wasting-like syndrome in cancer patients. Furthermore, re-expression of PINK1 fully rescued defects in carbohydrate metabolism and systemic growth induced by the tissue-specific pten mutations. Our data suggest a new function for PINK1 in regulating systemic growth in Drosophila, and shed light on its role in wasting in context of PTEN mutations.
Project description:Mutations in PTEN-induced putative kinase 1 (PINK1) cause autosomal recessive early onset Parkinson disease (PD). PINK1 is a Ser/Thr kinase that regulates mitochondrial quality control by triggering mitophagy mediated by the ubiquitin ligase Parkin. Upon mitochondrial damage, PINK1 accumulates on the outer mitochondrial membrane (OMM) forming a high molecular weight complex with the translocase of the outer membrane (TOM). PINK1 then phosphorylates ubiquitin, which enables recruitment and activation of Parkin followed by autophagic clearance of the damaged mitochondrion. Thus, Parkin-dependent mitophagy hinges on the stable accumulation of PINK1 on the TOM complex. Yet, the mechanism linking mitochondrial stressors to PINK1 accumulation and whether the translocases of the inner membrane (TIMs) are also involved, remain unclear. Herein, we demonstrate that mitochondrial stress induces the formation of a PINK1-TOM-TIM23 supercomplex in human cultured cell lines, dopamine neurons, and midbrain organoids. Moreover, we show that PINK1 is required to stably tether the TOM to TIM23 complexes in response to stress, such that the supercomplex fails to accumulate in cells lacking PINK1. This tethering is dependent on an interaction between the PINK1 NT-CTE module and the cytosolic domain of the Tom20 subunit of the TOM complex, the disruption of which, by either designer or PD-associated PINK1 mutations, inhibits downstream mitophagy. Together, the findings provide key insight into how PINK1 interfaces with the mitochondrial import machinery, with important implications for the mechanisms of mitochondrial quality control and PD pathogenesis.