Project description:Background: Age-dependent renal impairment contributes to renal dysfunction in both the general population and young and middle-aged patients with renal diseases. Pathological changes in age-dependent renal impairment include glomerulosclerosis and tubulointerstitial fibrosis. The molecules involved in age-dependent renal impairment are not fully elucidated. MicroRNA (miRNA) species were reported to modulate various renal diseases, but the miRNA species involved in age-dependent renal impairment are unclear. Here, we investigated miRNAs in age-dependent renal impairment, and we evaluated their potential as biomarkers and therapeutic targets. Methods: We conducted an initial microarray profiling analysis to screen miRNAs whose expression levels changed in kidneys of senescence-accelerated resistant (SAMR1)-10-week-old (wk) mice and SAMR1-50wk mice and senescence-accelerated prone (SAMP1)-10wk mice and SAMP1-50wk mice. We then evaluated the expressions of differentially expressed miRNAs in serum from 13 older patients (>65 years old) with age-dependent renal impairment (estimated glomerular filtration ratio <60 mL/min/1.73 m2) by a quantitative real-time polymerase chain reaction (qRT-PCR) and compared the expressions with those of age-matched subjects with normal renal function. We also administered miRNA mimics or inhibitors (5 nmol) with a nonviral vector (polyethylenimine nanoparticles: PEI-NPs) to SAMP1-20wk mice to investigate the therapeutic effects. Results: The qRT-PCR revealed a specific miRNA (miRNA-503-5p) whose level was significantly changed in SAMP1-50wk mouse kidneys in comparison to the controls. The expression level of miRNA-503-5p was upregulated in the serum of the 13 patients with age-dependent renal impairment compared to the age-matched subjects with normal renal function. The administration of a miRNA-503-5p-inhibitor with PEI-NPs decreased the miRNA-503-5p expression levels, resulting in the inhibition of renal fibrosis in mice via an inhibition of a pro-fibrotic signaling pathway and a suppression of glomerulosclerosis in mice by inhibiting intrinsic signaling pathways. Conclusion: miRNA-503-5p may represent a biomarker for age-dependent renal impairment, and the inhibition of miRNA-503-5p had no effect on age-dependent renal impairment. However, the inhibition of miRNA-503-5p had therapeutic effects on renal fibrosis and glomerulosclerosis.
Project description:In general populations, age-dependent renal impairment contributes to the progression of renal dysfunction. It has not been known which molecules are involved in age-dependent renal im-pairment. Messenger RNA (mRNA) has been reported to modulate various renal diseases, and we therefore investigated mRNA signatures in age-dependent renal impairment. We performed an initial microarray-profiling analysis to screen mRNAs, the expression levels of which changed in the kidneys of 50-week-old senescence-accelerated prone (SAMP1) mice (which have accelerated age-dependentd renal impairments) compared with those of 50 -wk- old senes-cence-accelerated-resistant (SAMR1) mice (which have normal aged kidneys) and with younger (10 -wk- old) SAMP1 and SAMR1 mice. We next assessed the expressions of mRNAs that were differentially expressed in the kidneys of SAMP1-50wk mice by conducting a quantitative real-time polymerase chain reaction (qRT-PCR) and compared the expressions among the SAMP1-10wk, SAMR1-10wk, and SAMR1-50wk mice. The results of the microarray together with the qRT-PCR analysis revealed five mRNAs whose expression levels were significantly altered in SAMP1-50wk mouse kidneys versus the control mice. The expression levels of the five mRNAs’ expression levels were increased in the kidneys of the mice with age-dependent renal impairment. Our findings in-dicate that the five mRNAs might be related and could become therapeutic targets for age-dependent renal impairment.
Project description:FUS is a primarily nuclear RNA-binding protein with important roles in RNA processing and transport. FUS mutations disrupting its nuclear localization characterize a subset of amyotrophic lateral sclerosis (ALS-FUS) patients, through an unidentified pathological mechanism. FUS regulates nuclear RNA, but its role at the synapse is poorly understood. Here, we used super-resolution imaging to determine the physiological localization of extranuclear, neuronal FUS and found it predominantly near the vesicle reserve pool of presynaptic sites. Using CLIP-seq on synaptoneurosome preparations, we identified synaptic RNA targets of FUS that are associated with synapse organization and plasticity. Synaptic FUS was significantly increased in a knock-in mouse model of ALS-FUS, at presymptomatic stages. Despite apparently unaltered synaptic organization, RNA-seq of synaptoneurosomes highlighted age-dependent dysregulation of glutamatergic and GABAergic synapses. Our study indicates that FUS relocalization to the synapse in early stages of ALS-FUS results in synaptic impairment, potentially representing an initial trigger of neurodegeneration.
Project description:FUS is a primarily nuclear RNA-binding protein with important roles in RNA processing and transport. FUS mutations disrupting its nuclear localization characterize a subset of amyotrophic lateral sclerosis (ALS-FUS) patients, through an unidentified pathological mechanism. FUS regulates nuclear RNA, but its role at the synapse is poorly understood. Here, we used super-resolution imaging to determine the physiological localization of extranuclear, neuronal FUS and found it predominantly near the vesicle reserve pool of presynaptic sites. Using CLIP-seq on synaptoneurosome preparations, we identified synaptic RNA targets of FUS that are associated with synapse organization and plasticity. Synaptic FUS was significantly increased in a knock-in mouse model of ALS-FUS, at presymptomatic stages. Despite apparently unaltered synaptic organization, RNA-seq of synaptoneurosomes highlighted age-dependent dysregulation of glutamatergic and GABAergic synapses. Our study indicates that FUS relocalization to the synapse in early stages of ALS-FUS results in synaptic impairment, potentially representing an initial trigger of neurodegeneration.
Project description:FUS is a primarily nuclear RNA-binding protein with important roles in RNA processing and transport. FUS mutations disrupting its nuclear localization characterize a subset of amyotrophic lateral sclerosis (ALS-FUS) patients, through an unidentified pathological mechanism. FUS regulates nuclear RNA, but its role at the synapse is poorly understood. Here, we used super-resolution imaging to determine the physiological localization of extranuclear, neuronal FUS and found it predominantly near the vesicle reserve pool of presynaptic sites. Using CLIP-seq on synaptoneurosome preparations, we identified synaptic RNA targets of FUS that are associated with synapse organization and plasticity. Synaptic FUS was significantly increased in a knock-in mouse model of ALS-FUS, at presymptomatic stages. Despite apparently unaltered synaptic organization, RNA-seq of synaptoneurosomes highlighted age-dependent dysregulation of glutamatergic and GABAergic synapses. Our study indicates that FUS relocalization to the synapse in early stages of ALS-FUS results in synaptic impairment, potentially representing an initial trigger of neurodegeneration.
Project description:The mechanisms underlying age-associated memory impairment are not well understood. We have shown that the onset of memory disturbances in the aging brain is associated with altered hippocampal chromatin plasticity. During learning, aged mice display a specific deregulation of histone H4 lysine 12 (H4K12) acetylation. To analyze if deregulated H4K12 acetylation impacts on learning-induced gene-expression required for memory consolidation we performed a high-density oligonucleotide microarray to compare the entire hippocampal gene-expression profile of 3 and 16-month-old mice during memory consolidation.