Project description:Background: Specific microglia responses are thought to contribute to the development and progression of neurodegenerative diseases, including Parkinson’s disease (PD). However, the phenotypic acquisition of microglial cells and their role during the underlying neuroinflammatory processes remain largely elusive. Here, according to the multiple-hit hypothesis, which stipulates that PD etiology is determined by a combination of genetics and various environmental risk factors, we investigate microglial transcriptional programs and morphological adaptations under PARK7/DJ-1 deficiency, a genetic cause of PD, during lipopolysaccharide (LPS)-induced inflammation. Methods: Using a combination of single-cell RNA-sequencing, bulk RNA-sequencing, multicolor flow cytometry and immunofluorescence analyses, we comprehensively compared microglial cell phenotypic characteristics in PARK7/DJ-1 knock-out (KO) with wildtype littermate mice following 6- or 24-hour intraperitoneal injection with LPS. In a translational approach, we conducted corresponding analyses in human PARK7/DJ-1 mutant induced pluripotent stem cell (iPSC)-derived microglia and murine bone marrow-derived macrophages (BMDMs). Results: By excluding the contribution of other immune brain resident and peripheral cells, we show that microglia acutely isolated from PARK7/DJ-1 KO mice display a distinct phenotype, specially related to type II interferon and DNA damage response signaling, when compared with wildtype microglia, in response to LPS. We also detected discrete signatures in human PARK7/DJ-1 mutant iPSC-derived microglia and BMDMs from PARK7/DJ-1 KO mice. These specific transcriptional signatures were reflected at the morphological level, with microglia in LPS-treated PARK7/DJ-1 KO mice showing a less amoeboid cell shape compared to wildtype mice, both at 6 and 24 hours after acute inflammation, as also observed in BMDMs. Conclusions: Taken together, our results show that, under inflammatory conditions, PARK7/DJ-1 deficiency skews microglia towards a distinct phenotype characterized by downregulation of genes involved in type II interferon signaling and a less prominent amoeboid morphology compared to wildtype microglia. These findings suggest that the underlying oxidative stress associated with the lack of PARK7/DJ-1 affects microglia neuroinflammatory responses, which may play a causative role in PD onset and progression.

Project description:Background: Specific microglia responses are thought to contribute to the development and progression of neurodegenerative diseases, including Parkinson’s disease (PD). However, the phenotypic acquisition of microglial cells and their role during the underlying neuroinflammatory processes remain largely elusive. Here, according to the multiple-hit hypothesis, which stipulates that PD etiology is determined by a combination of genetics and various environmental risk factors, we investigate microglial transcriptional programs and morphological adaptations under PARK7/DJ-1 deficiency, a genetic cause of PD, during lipopolysaccharide (LPS)-induced inflammation. Methods: Using a combination of single-cell RNA-sequencing, bulk RNA-sequencing, multicolor flow cytometry and immunofluorescence analyses, we comprehensively compared microglial cell phenotypic characteristics in PARK7/DJ-1 knock-out (KO) with wildtype littermate mice following 6- or 24-hour intraperitoneal injection with LPS. For translational perspectives, we conducted corresponding analyses in human PARK7/DJ-1 mutant induced pluripotent stem cell (iPSC)-derived microglia and murine bone marrow-derived macrophages (BMDMs). Results: By excluding the contribution of other immune brain resident and peripheral cells, we show that microglia acutely isolated from PARK7/DJ-1 KO mice display a distinct phenotype, specially related to type II interferon and DNA damage response signaling, when compared with wildtype microglia, in response to LPS. We also detected discrete signatures in human PARK7/DJ-1 mutant iPSC-derived microglia and BMDMs from PARK7/DJ-1 KO mice. These specific transcriptional signatures were reflected at the morphological level, with microglia in LPS-treated PARK7/DJ-1 KO mice showing a less amoeboid cell shape compared to wildtype mice, both at 6 and 24 hours after acute inflammation, as also observed in BMDMs. Conclusions: Taken together, our results show that, under inflammatory conditions, PARK7/DJ-1 deficiency skews microglia towards a distinct phenotype characterized by downregulation of genes involved in type II interferon signaling and a less prominent amoeboid morphology compared to wildtype microglia. These findings suggest that the underlying oxidative stress associated with the lack of PARK7/DJ-1 affects microglia neuroinflammatory responses, which may play a causative role in PD onset and progression.

Project description:Early-onset Parkinson's disease can be caused by mutations in the gene PARK7. Many functions have been proposed for PARK7, but in vivo evidence is largely lacking or conflicting with enzymological data. Here, we provide unequivocal evidence that PARK7 and its orthologues can prevent damage of proteins and metabolites inflicted by the glycolytic intermediate 1,3-bisphosphoglycerate, without changing the abundance of this metabolite. In the absence of PARK7, several glycerate-modified metabolites, as well as numerous glycerate- or phosphoglycerate-modified proteins accumulate in human cell lines, mouse brain and flies. This gives an explanation for the pleiotropic effects of PARK7, indicates that spontaneous metabolic damage contributes to the development of hereditary Parkinson's disease, and opens new roads for future therapeutic approaches. Submitted here are the proteomics analyses, where we identify and quantify glyceroyl- and phosphoglyceroyl-modifications of lysine residues in 5 different experimental models. 1. The human colorectal cancer cell line HCT116 was analyzed in four different conditions: a. Wild type cells transduced with an empty recombinant empty lentivirus b. PARK7 knockout cells transduced with an empty recombinant empty lentivirus c. PARK7 knockout cells transduced with a recombinant lentivirus driving expression of PARK7. 2. Brain samples from wild type and PARK7 knockout mice. 3. Red blood cell lysates from wild type and PARK7 knockout mice 4. Whole body extracts from wild type and DJ1beta knockout Drosophila melanogaster 5. In vitro reactions where 1,3-bisphosphoglycerate was produced either by GAPDH or PGK, in the presence and absence of PARK7. Samples were a. Enzymes in the absence of any cofactors (i.e. no 1,3-BPG production) b. Production via GAPDH (using glyceraldehyde 3-phosphate, phosphate and NAD+ as substrates) in the presence or absence of PARK7 c. Production via PGK (using 3-phosphoglycerate and ATP as substrates) in the presence or absence of PARK7.

Project description:Many biological processes involve the mechanistic/mammalian target of rapamycin complex 1 (mTORC1). Thus, the challenge of deciphering mTORC1-mediated functions during normal and pathological states in the central nervous system is steep. Because mTORC1 is at the core of translation, we have investigated mTORC1 function in global and regional protein expression. Activation of mTORC1 has been generally regarded to promote translation. Few but recent works have demonstrated that suppression of mTORC1 can promote local protein synthesis. Moreover, excessive mTORC1 activation during disease states represses basal and activity-induced protein synthesis. To determine the role of mTORC1 activation in protein expression, we have used an unbiased, large scale proteomic approach. We provide evidence that a brief repression of mTORC1 activity in vivo by rapamycin has little affect globally, yet leads to a significant remodeling of synaptic proteins, in particular those proteins that reside in the postsynaptic density (PSD). We have also found that curtailing the activity of mTORC1 bidirectionally alters the expression of proteins associated with epilepsy, Alzheimer’s disease, and autism spectrum disorder (ASD)—neurological disorders that exhibit elevated mTORC1 activity. Through a protein-protein interaction network analysis, we have identified common proteins shared among these mTOR-related diseases. One such protein is Parkinson protein 7 (PARK7) which has been implicated in Parkinson’s disease, yet not associated with epilepsy, AD, or ASD. To verify our finding, we provide evidence that the protein expression of PARK7, including new protein synthesis, is sensitive to mTORC1 inhibition. Using cultured neurons from a mouse model of tuberous sclerosis complex (TSC), a disease that displays both epilepsy and ASD phenotypes and has overactive mTOR signaling, we show that PARK7 protein is elevated in the dendrites. Our work offers a comprehensive view of mTORC1 and its role in regulating regional protein expression in normal and diseased states.

			Action	DRS
	ERR10892700_1.fastq.gz	Fastqsanger.gz
	ERR10892700_2.fastq.gz	Fastqsanger.gz
	ERR10892701_1.fastq.gz	Fastqsanger.gz
	ERR10892701_2.fastq.gz	Fastqsanger.gz
	ERR10892702_1.fastq.gz	Fastqsanger.gz

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Helgueta Park7

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