Project description:Neuroinflammation is a key component of Alzheimer's disease (AD), and it may be driven by the activation of NFκB and NLRP3 signaling pathways. AD pathology, like amyloid-β, may exacerbate the activation of these pathways. We used a nucleic acid therapeutic (nanoligomer) cocktail targeting NFκB and NLRP3 to reduce inflamamtory signaling in aged wildtype mice and a transgenic mouse model of amyloid-β pathology (APP/PS1). Short-term (3 days) treatment reversed age- and amyloid-β-related gene sigantures, supporting the idea that this nanoligomer cocktail may have the potential to improve AD-related neuroinflammation and cognitive dysfunction.
Project description:Neuroinflammation contributes to impaired cognitive function in brain aging and neurodegenerative disorders like Alzheimer’s disease, which is characterized by the aggregation of pathological tau. One major driver of both age- and tau-associated neuroinflammation is the NF-κB and NLRP3 signaling axis. However, current treatments targeting NF-κB or NLRP3 may have adverse/systemic effects, and most have not been clinically translatable. Here, we tested the efficacy of a novel, nucleic acid therapeutic (Nanoligomer) cocktail specifically targeting both NF-κB and NLRP3 in the brain for reducing neuroinflammation and improving cognitive function in old wildtype mice, and in a mouse model of tauopathy. We found that 4 weeks of NF-κB/NLRP3-targeting Nanoligomer treatment strongly reduced neuro-inflammatory cytokine profiles in the brain and improved cognitive-behavioral function in both old and tauopathy mice. These effects of NF-κB/NLRP3-targeting Nanoligomer treatment were associated with reduced glial cell activation in old wildtype mice, less pathology in tauopathy mice, favorable changes in transcriptome signatures of inflammation (reduced) and neuronal health (increased) in both mouse models, and no adverse systemic effects. Collectively, our results provide a basis for future translational studies targeting NF-κB/NLRP3 in the brain, perhaps using Nanoligomers, to inhibit neuroinflammation and improve cognitive function with aging and neurodegenerative disease.
Project description:We investigated the novel molecular mechanisms of the antioxidant and anti-inflammatory properties of S-allylmercaptocysteine (SAMC) based on a transcriptomic study in a non-alcoholic fatty liver disease (NAFLD) rat model. NAFLD was induced in Sprague-Dawley rats by feeding with a high fat diet (HFD) for 12 weeks. 200mg/kg SAMC was fed by oral gavage for 4 weeks from 9-12 week. We found that SAMC co-administration attenuated HFD-induced liver injury, including the increased serum ALT, hepatic oxidative stress and inflammation. Transcriptomic analysis revealed that SAMC dramatically induced the XRE- and ARE-driven drug metabolising enzymes (DMEs) including Akr7a3, Akr1b8, and NQO1. The nuclear translocation of the upstream regulator of xenobiotics metabolism, AhR, and regulator of antioxidant responses, Nrf2, were significantly increased by SAMC treatment. Furthermore, SAMC counteracted the effects of HFD on NF-κB/IκB and NLRP3/6 pathways with decreasing protein levels of ASC, cleaved caspase-1, IL-18 and IL-1β. These results were further verified in another mice NASH model induced by an MCD diet with SAMC co-administration. Conclusion: we propose that SAMC triggers AhR/Nrf2-mediated antioxidant responses which may further suppress the NLRP3/6 inflammasome pathway and NF-κB activation, contributing to the improvement of NAFLD/NASH.
Project description:Background: Cardiac Ryanodine receptors (RyR2) can regulate Ca2+ release in the excitation-contraction coupling, when activated, it releases a large amount of Ca2+ into the cytoplasm. Additionally, studies have shown that dantrolene (a RyR2 inhibitor) protects against heart failure and arrhythmias by inhibiting domain decompression, Ca2+ leakage and diastolic Ca2+ sparking. However, the role and mechanism of dantrolene in cardiac hypertrophy remain unclear. Objective: In this study, we aimed to evaluate the therapeutic effects of dantrolene on pressure overload-induced cardiac hypertrophy in mice models by transverse aortic contraction (TAC) surgery and to explore its potential mechanism. Methods: C57/B6 mice (age: 8 weeks) underwent TAC or sham surgical procedure and were administered oral dantrolene (30 mg/kg) or the solvent drug postoperatively. After 4 weeks of drug treatment, RNA sequencing of mice left ventricle was performed.qRT–PCR validation was performed using SYBR Green assays. Results: We found that dantrolene significantly alleviated TAC-induced cardiac hypertrophy. According to RNA sequencing, 184 down-regulated genes were found after dantrolene treatment compared with TAC group, 8 of these were validated with qRT–PCR. According to the KEGG analysis, Creb3l3, IL18R1 and Ccl5 were down-regulated after dantrolene treatment, which were related to TNF-α pathway. Conclusion: As a RyR2 inhibitor, dantrolene attenuates cardiac hypetrophy through downregulating the TNF-α/NF-κB/NLRP3 signaling pathway.
Project description:Activation of the NLRP3 inflammasome has been implicated in the pathogenesis of Alzheimer’s disease (AD), via the characterised release of IL-1β and ASC specks. However, whether NLRP3 was involved in pathways beyond this remained unknown. Here were enriched CD11b+ cells from the brains of 4, 6 an 12 month old wild-type, NLRP3-/-, APP/PS1 and APP/PS1.NLRP3-/- mice for bulk RNA sequencing. We found that amyloid deposition was associated with an increase in the expression of genes encoding inflammatory or phagocytic proteins from 6 months onwards. Interestingly, loss of NLRP3 influences glutamine/glutamate-related metabolism and increases expression of microglial Slc1a3. The increase in Slc1a3 was observed in all mice on a NLRP3-/- background and at all ages examined, demonstrating a new role for this transporter in microglia.
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) fibroblasts and induced pluripotent stem cells (iPSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS fibroblasts were reprogrammed. RNA was extracted and transcriptional profiling was obtained with GeneChip Human Exon 1.0 ST Arrays.
Project description:Transcriptional profiling of human control and Néstor-Guillermo Progeria Syndrome (NGPS) mesenchymal stem cells (MSCs). Somatic cell reprogramming involves rejuvenation of adult cells and relies on the ability to erase age-associated molecular marks. Accordingly, reprogramming efficiency declines with ageing, and age-associated features such as genetic instability, cell senescence or telomere shortening negatively affect this process. However, the regulatory mechanisms that constitute age-associated barriers for cell reprogramming remain largely unknown. Here, by using cells from patients with premature ageing, we demonstrate that NF-κB activation is a critical barrier for the generation of induced pluripotent stem cells (iPSCs) in ageing. We show that NF-κB repression occurs during cell reprogramming towards a pluripotent state. Conversely, ageing-associated NF-κB hyperactivation impairs generation of iPSCs by eliciting reprogramming repressors DOT1L and YY1, reinforcing cell senescence signals and down-regulating pluripotency genes. We also show that genetic and pharmacological NF-κB inhibitory strategies significantly increase the reprogramming efficiency of fibroblasts from Néstor-Guillermo Progeria Syndrome (NGPS) and Hutchinson-Gilford Progeria Syndrome (HGPS) patients, as well as from normal aged donors. Finally, we demonstrate that DOT1L inhibition in vivo ameliorates the accelerated ageing phenotype and extends lifespan in a progeroid animal model. Collectively, our results provide evidence for a novel role of NF-κB in the control of cell fate transitions and reinforce the interest of studying age-associated molecular impairments to implement cell reprogramming methodologies, and to identify new targets of rejuvenation strategies. Control and NGPS MSCs were differentiated into bone in the presence or absence of sodium salicylate. Total RNA was extracted and global gene expression was analyzed.