Dataset Information

Cerebrospinal fluid ecto-GPR37 in Parkinson’s disease

ABSTRACT: Improved diagnostic and prognostic biomarkers which reflect pathological progression would benefit the management of Parkinson’s disease. GPR37, also known as parkin associated endothelin-like (Pael) receptor, is an orphan G protein-coupled receptor, which has a defective parkin-mediated ubiquitination in autosomal recessive Parkinson’s disease. By means of immunoblot and mRNA determinations we detected increased GPR37 levels in postmortem substantia nigra from Parkinson’s disease subjects. We revealed the presence of the N-terminal domain of GPR37 (ecto-GPR37) in human and mouse cerebrospinal fluid (CSF). We engineered a Nanoluciferase-based ELISA to evaluate ecto-GPR37 in CSF and demonstrated the presence of ecto-GPR37 in CSF from wild-type, but not from GPR37-/-, mice. Subsequently, the relative abundance of ecto-GPR37 in CSF in healthy controls (n=48) and Parkinson’s disease (n=45) patients was assessed. Interestingly, we found that ecto-GPR37 was significantly increased (P = 0.0002) in the CSF from Parkinson’s disease patients. Importantly, mass spectrometric analysis of immunoprecipitation of GPR37 in CSF supported the analytical validity of our ELISA to measure ecto-GPR37 in human CSF. Overall, these results open exciting perspectives and encourage further systemically studies to confirm the clinical validity and utility of ecto-GPR37 as a potential Parkinson’s disease diagnostic/prognostic biomarker

INSTRUMENT(S): LTQ Orbitrap Velos

ORGANISM(S): Homo Sapiens (human)

TISSUE(S): Cerebrospinal Fluid

DISEASE(S): Parkinson's Disease

SUBMITTER: Eva Borràs

LAB HEAD: Eduard Sabidó

PROVIDER: PXD015619 | Pride | 2021-05-13

REPOSITORIES: Pride

ACCESS DATA

Dataset's files

Source:

			Action	DRS
	180521_S_CIRL_01_03_B_digested_45pto.raw	Raw
	180521_S_CIRL_02_02_B_digested_45pto.raw	Raw
	180521_S_CIRL_03_02_B_digested_45pto.raw	Raw
	180521_S_CIRL_digested_45pto.msf	Msf

Items per page:

1 - 4 of 4

Similar Datasets

Project description:Loss-of-function mutations in the parkin gene can cause early onset Parkinson’s disease, a movement disorder resulting from the selective degeneration of dopaminergic neurons in the basal ganglia. Analogously, movement deficits and loss of a subset of dopaminergic neurons are observed in Drosophila melanogaster homozygous for null mutations in parkin. Parkin is an E3 ubiquitin ligase that functions with the mitochondrial localized serine/threonine kinase PINK1 in a pathway required to maintain mitochondrial integrity. We previously established that the PINK1/Parkin pathway functions in Drosophila dopaminergic and cholinergic neurons to maintain mitochondrial membrane potential. However, the mechanisms through which the PINK/Parkin pathway selectively impacts dopaminergic neuron survival remains unclear, as do the mechanisms that lead to the selective vulnerability of dopaminergic neurons in Parkinson’s disease. Because the transcriptome of a cell determines its identity we hypothesized that knowledge of the transcriptional alterations that occur in dopaminergic neurons isolated from parkin null Drosophila would provide insight into the mystery of selective vulnerability in Parkinson's disease. Results: To test our hypothesis we measured the transcriptome of dopaminergic and cholinergic neurons isolated from isogenic heterozygous and homozygous parkin null mutants using a novel flow cytometry-based method we developed. Computational analysis and experimental confirmation demonstrate that our method allows for the successful expression analysis of defined neural subsets from the Drosophila brain. In addition, our dataset implicates iron handling and dopamine signaling as being significantly dysregulated in parkin null dopaminergic neurons. Conclusions: Our flow cytometry-based method allows for the isolation and microarray analysis of neuronal subsets from the adult Drosophila brain. Our microarray analyses implicate iron handling and dopamine metabolism as contributing factors in the etiology of parkin-associated early onset Parkinson’s disease. Here we provide a novel dataset that may serve as a foundation for subsequent functional analyses of the pathways underlying neuronal selective vulnerability in Parkinson's disease.

Project description:Mutations in the E3 ubiquitin ligase Parkin cause autosomal recessive Parkinson’s disease. In concert with PINK1, Parkin regulates the clearance of dysfunctional mitochondria via lysosomes. In response, new mitochondria are generated through an interplay of nuclear- and mitochondrial-encoded proteins. Mouse and overexpression models suggests that Parkin also influences these processes, both in the nuclear cascade and at the level of the mitochondrial genome. Additionally, Parkin has been shown to prevent mitochondrial membrane permeation, impeding the escape of mitochondrial DNA (mtDNA). In line with this, serum from Parkin mutation carriers showed higher levels of circulating cell-free mtDNA (ccf-mtDNA) and inflammatory cytokines – a result of the innate immune response - which can be triggered by cytosolic mtDNA. However, Parkin’s relationship with the mitochondrial genome and the mitogenesis pathway has not been explored in patient-derived neurons. To investigate this aspect of Parkin’s cellular function endogenously, we generated induced pluripotent stem cell (iPSC)-derived midbrain neurons from Parkin mutation carriers and healthy controls. In Parkin-deficient cells, several factors in the mitochondrial biogenesis pathway were significantly reduced, resulting in impaired mtDNA homeostasis - a phenomenon that was exacerbated in dopaminergic neurons. Moreover, in response to a lack of freely accessible NAD+, the energy sensor Sirtuin 1, which simultaneously controls mtDNA maintenance processes and mitophagy, was downregulated in Parkin-deficient neurons. However, while impaired lysosomal degradation of mitochondria was only detectable in oxidative conditions, biogenesis defects were already apparent in untreated patient neurons. This may suggest that mitophagy disruption occurs in response to acute stress. By contrast, the biogenesis pathway may be continually impaired in Parkin-associated Parkinson’s disease. Next, using a mutagenic stress model in combination with Parkin knockdown, we detected an increase in ccf-mtDNA and the cytosolic DNA sensor cGAS. To explore if ccf-mtDNA can act as damage-associated molecular pattern in the brain, we used postmortem tissue from a Parkin mutation carrier and performed single-cell RNA sequencing. In the midbrain lacking Parkin, we found a higher percentage of microglia along with an upregulation of proinflammatory cytokines in these cells. Together, our findings suggest a role for Parkin in the control of mitochondrial biogenesis and mtDNA maintenance, which protects midbrain neurons from neuroinflammation-induced degeneration. Future research in iPSC-derived neuron-microglia co-culture systems could aim at developing PD treatment approaches that target the neuronal release or microglial uptake of ccf-mtDNA.

Dataset Information

Cerebrospinal fluid ecto-GPR37 in Parkinson’s disease

Dataset's files

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets