Project description:our data showed that the absence of DJ-1 had no adverse effects on proliferation, differentiation, and oxidative stress responses of human stem cells such as hNSCs and hMSCs as well as hVECs, suggesting that loss of DJ-1 function alone is insufficient to disrupt the homeostasis of these human cells. In addition, we found that CHCHD2 was upregulated upon DJ-1 deficiency, which may account for the absence of severe phenotypes in various types of DJ-1-deficient cells. For the first time, our study revealed the 'see-saw' expression pattern of two Parkinson’s disease-associated genes, providing potential clues for understanding the mechanisms of DJ-1- and CHCHD2-associated Parkinson’s disease.
Project description:Pyruvate dehydrogenase (PDH) is the gatekeeper enzyme of the tricarboxylic acid (TCA) cycle. Here we show that the deglycase DJ-1 (encoded by PARK7, a key familial Parkinson's disease gene) is a pacemaker regulating PDH activity in CD4+ regulatory T cells (Treg cells). DJ-1 binds to PDHE1-β (PDHB), inhibiting phosphorylation of PDHE1-α (PDHA), thus promoting PDH activity and oxidative phosphorylation (OXPHOS). Park7 (Dj-1) deletion impairs Treg survival starting in young mice and reduces Treg homeostatic proliferation and cellularity only in aged mice. This leads to increased severity in aged mice during the remission of experimental autoimmune encephalomyelitis (EAE). Dj-1 deletion also compromises differentiation of inducible Treg cells especially in aged mice, and the impairment occurs via regulation of PDHB. These findings provide unforeseen insight into the complicated regulatory machinery of the PDH complex. As Treg homeostasis is dysregulated in many complex diseases, the DJ-1-PDHB axis represents a potential target to maintain or re-establish Treg homeostasis.
Project description:Excessive reactive oxygen species (ROS) underlie the pathogenesis of multiple disorders. Nevertheless, physiological levels of ROS are required for intracellular signalling and maintenance of metabolic homeostasis. DJ-1, a Parkinson’s disease-associated protein, is involved in the regulation of oxidative stress. Our aim in this study was to determine the effect of DJ-1 disruption on gene expression in muscle cells. To this end, we transfected a murine myoblast cell line, C2C12 cells with siRNA targeting DJ-1.
Project description:Decline in immune function during aging increases susceptibility to different aging related diseases. However, the underlying molecular mechanisms, especially the genetic factors contributing to imbalance of naïve/memory T-cell subpopulations, still remain largely elusive. Here we show that loss of DJ-1 encoded by PARK7/DJ-1, causing early-onset familial Parkinson’s disease (PD), unexpectedly diminished signs of immunoaging in T-cell compartments of both human and mice. Compared with two gender-matched unaffected siblings of similar ages, the index PD patient with DJ-1 deficiency showed a decline in many critical immunoaging features, including almost doubled non-senescent T cells. The observation was further consolidated by the results in 45-week-old DJ-1 knockout mice. Our data demonstrated that DJ-1 regulates several immunoaging features via hematopoietic-intrinsic and naïve-CD8-intrinsic mechanisms. Mechanistically, DJ-1 depletion reduced oxidative phosphorylation (OXPHOS) and impaired TCR sensitivity in naïve CD8 T cells at a young age, accumulatively leading to a reduced aging process in T-cell compartments in older mice. Our finding suggests an unrecognized critical role of DJ-1 in regulating immunoaging, discovering a potent target to interfere with immunoaging- and aging-associated diseases.
Project description:Background DJ-1 is an antioxidant protein known to regulate mast cell mediated allergic response, but its role in airway eosinophilic interactions and allergic inflammation is not known. Objective The aim of this study was to investigate the role of DJ-1 in airway eosinophilic inflammation in vitro and in vivo. Methods Ovalbumin-induced airway allergic inflammation was established in mice. ELISA was adopted to analyze DJ-1 and cytokine levels in mouse bronchoalveolar lavage fluid. Transcriptional profiling of mouse lung tissues was conducted by single-cell RNA sequencing technology. The role of DJ-1 in the differentiation of airway progenitor cells into goblet cells was examined by organoid cultures, immunofluorescence staining, quantitative PCR, and cell transplantation in normal, DJ-1 knockout (KO), or conditional DJ-1 KO mice. Results We observed that DJ-1 was increased in the lung tissues of ovalbumin-sensitized and challenged mice. DJ-1 KO mice exhibited reduced airway eosinophil infiltration and goblet cell differentiation. Mechanistically, we discovered that eosinophil-club cell interactions are reduced in the absence of DJ-1. Organoid cultures indicated that eosinophils impair the proliferative potential of club cells. Intratracheal transplantation of DJ-1-deficient eosinophils suppresses airway goblet cell differentiation. Loss of DJ-1 inhibits the metabolism of arachidonic acid into cysteinyl leukotrienes in eosinophils while these secreted metabolites promote airway goblet cell fate in organoid cultures and in vivo. Conclusion DJ-1-mediated interactions between airway epithelial progenitor cells and immune cells are essential in controlling airway goblet cell metaplasia and eosinophilia. Blockade of the DJ-1 pathway is protective against airway allergic inflammation.
Project description:Although the mTOR-4E-BP1 signaling pathway is implicated in aging and aging-related disorders, the role of 4E-BP1 in regulating human stem cell homeostasis remains largely unknown. Here, we report that the expression of 4E-BP1 decreases along with the senescence of human mesenchymal stem cells (hMSCs). Genetic inactivation of 4E-BP1 in hMSCs accelerates cellular senescence, compromises mitochondrial respiration and increases mitochondrial ROS production. Mechanistically, the absence of 4E-BP1 destabilizes proteins in mitochondrial respiration complexes, especially several key subunits of the complex III including UQCRC2. Ectopic expression of 4E-BP1 attenuates mitochondrial abnormalities and alleviates cellular senescence in 4E-BP1-deficient hMSCs as well as in physiologically aged hMSCs. These findings together demonstrate that 4E-BP1 functions as a geroprotector to alleviate human stem cell senescence and maintain mitochondrial homeostasis, particularly for the mitochondrial respiration complex III and provide a new potential target to counteract human stem cell senescence.
Project description:DJ-1 is an atypical peroxiredoxin-like peroxidase that may act as a redox-dependent chaperone and a regulator of transcription. To explore DJ-1-mediated transcriptional control in Parkinson’s disease (PD), we generated human neuroblastoma cells with inducible knock-down of DJ-1 expression. We then used functional genomic techniques to identify novel pathways dysregulated by loss of DJ-1 function. Using microarray gene expression profiling, we found that DJ-1 silencing alters the expression of 26 genes, with 10 down-regulated and 16 up-regulated transcripts. Among the down-regulated genes we found Ret, tyrosine kinase receptor for the neurotrophic factor GDNF. Taking advantage of Ingenuity Pathways Analysis, we identified hypoxia inducible factor 1 alpha (Hif1a) as a possible mediator of the interplay between DJ-1 and Ret. We show that Hif1a is stabilized in the absence of DJ-1, and that loss of DJ-1 generates hypoxia and accumulation of free radical species (ROS). Overexpression of wt DJ-1, but not of C106A and L166P mutants deficient in ROS scavenger activity, rescues Ret expression in neuroblastoma cells. These findings reveal novel players in PD pathogenesis and provide evidence for additional pathways involved in DJ-1-mediated neurodegeneration.
Project description:DJ-1 is an atypical peroxiredoxin-like peroxidase that may act as a redox-dependent chaperone and a regulator of transcription. To explore DJ-1-mediated transcriptional control in Parkinsonâ??s disease (PD), we generated human neuroblastoma cells with inducible knock-down of DJ-1 expression. We then used functional genomic techniques to identify novel pathways dysregulated by loss of DJ-1 function. Using microarray gene expression profiling, we found that DJ-1 silencing alters the expression of 26 genes, with 10 down-regulated and 16 up-regulated transcripts. Among the down-regulated genes we found Ret, tyrosine kinase receptor for the neurotrophic factor GDNF. Taking advantage of Ingenuity Pathways Analysis, we identified hypoxia inducible factor 1 alpha (Hif1a) as a possible mediator of the interplay between DJ-1 and Ret. We show that Hif1a is stabilized in the absence of DJ-1, and that loss of DJ-1 generates hypoxia and accumulation of free radical species (ROS). Overexpression of wt DJ-1, but not of C106A and L166P mutants deficient in ROS scavenger activity, rescues Ret expression in neuroblastoma cells. These findings reveal novel players in PD pathogenesis and provide evidence for additional pathways involved in DJ-1-mediated neurodegeneration. Comparison between DJ-1-silenced human SH-SY5Y neuroblastoma cells and control cells. Two clones were selected for each condition, and each clone was analyzed in duplicate, for a total of 8 samples.
Project description:Decline in immune function during aging increases susceptibility to different aging related diseases. However, the underlying molecular mechanisms, especially the genetic factors contributing to imbalance of naïve/memory T-cell subpopulations, still remain largely elusive. Here we show that loss of DJ-1 encoded by PARK7/DJ-1, causing early-onset familial Parkinson’s disease (PD), unexpectedly diminished signs of immunoaging in T-cell compartments of both human and mice. Compared with two gender-matched unaffected siblings of similar ages, the index PD patient with DJ-1 deficiency showed a decline in many critical immunoaging features, including almost doubled non-senescent T cells. The observation was further consolidated by the results in 45-week-old DJ-1 knockout mice. Our data demonstrated that DJ-1 regulates several immunoaging features via hematopoietic-intrinsic and naïve-CD8-intrinsic mechanisms. Mechanistically, DJ-1 depletion reduced oxidative phosphorylation (OXPHOS) and impaired TCR sensitivity in naïve CD8 T cells at a young age, accumulatively leading to a reduced aging process in T-cell compartments in older mice. Our finding suggests an unrecognized critical role of DJ-1 in regulating immunoaging, discovering a potent target to interfere with immunoaging- and aging-associated diseases.