Although C9orf72 knockout mice do not show overt neurodegeneration, gain-of-function disease processes may trigger neurodegeneration through mechanisms induced by reduced C9ORF72 levels. For example, DPRs cause mis-splicing of the EAAT2 glutamate transporter in astrocytes, which couldincrease excitotoxicity in neurons with elevated glutamate receptor levels 12. To determine if DPRs alter glutamate uptake by astrocytes, we compared glutamate uptake in human primary astrocytes expressing either GFP or GR50 –GFP. Indeed, GR50 –GFP significantly impaired glutamate uptake by astrocytes (Supplementary Fig. 13h).

Our iMN survival results (Fig. 1c-e) suggest that the repeat expansion alters iMN glutamate sensing. In cortical neurons, homeostatic synaptic plasticity is maintained through endocytosis and subsequent lysosomal degradation of glutamate receptors in response to chronic glutamate signaling 45,46. Defects in this process lead to the accumulation of glutamate receptors on the cell surface 45,46.


In advanced traditional Chinese kung fu (martial arts), Neijing (Traditional Chinese: 內勁; pinyin: nèijìng) refers to the conscious control of the practitioner's qi, or "life energy", to gain advantages in combat.[1] Nèijìng is developed by using "Neigong" (Traditional Chinese: 內功; pinyin: nèigōng) (內功), or "internal exercises," as opposed to "wàigōng" (外功), "external exercises."
Libraries were prepared from total RNA using Clontech SMARTer Stranded RNA-Seq kit, with Clonetech RiboGone ribodepletion performed ahead of cDNA generation. Amounts of input RNA were estimated using the Bioanalyzer and libraries produced according to Clontech’s protocol. Library generation and sequencing were performed at the Norris Cancer Center Sequencing Core at USC. All FASTQ files were analyzed using FastQC (version 0.10.1), trimmed using the FASTQ Toolkit (v 1.0), aligned to the GRCh37/hg19 reference genome using Tophat (version 2), and transcripts assembled and tested for differential expression using Cufflinks (version 2.1.1). Raw data is available for public download in the NCBI database under accession code PRJNA296854.
Base text for this translation. ___. Wang Meng’ou’s , ed. Tangren xiaoshuo jiaoshi . Taipei: Zhongzheng Shuju, 1983, 2319-38. For other texts and editions see footnote 1. Translations Birch, Cyril. “The Curly-bearded Hero,” in Anthology of Chinese Literature, v. 1, New York, 1965, pp. 314-322. Chai, Ch’u, and Winberg Chai. “The Curly-Bearded Guest,” in A Treasury of Chinese Literature, New York, 1965, pp. 117-124. Hsu Sung-nien. “Biographie d’un preux barbu,” Anthologie de la littérature chinoise.Paris: Delagrave, 1933, pp. 241-6. Levenson, Christopher, tran., The Golden Casket. Harmondsworth, Middlesex: Penguin Books, 1967, pp. 137-47. Lévy, André. “Barbe-bouclée, L’étranger à la barbe et aux favoris bouclés,” in Histoires extraordinaires et récits fantastiques de la Chine ancienne.Paris: Flammarion, 1993, pp. 177-195 (with notes). Lin Yutang. “Curly-Beard,” in Famous Chinese Short Stories. New York: John Day (Cardinal), 1953, pp. 3-22. Schafer, E.H. “Three Divine Women of South China,” CLEAR, 1 (1979), pp. 31-42. Wang, Elizabeth Te-chen, tran. “The Curly-Bearded Guest,” in Wang’s Ladies of the Tang: 22 Classical Chinese Stories. Taipei: Mei Ya Publications, 1973, pp. 133-50.
Live imaging of iMNs expressing a M6PR-GFP fusion protein that localizes to M6PR+ vesicles 44 confirmed that C9ORF72 patient and C9ORF72-deficient iMNs possess increased numbers of M6PR+ vesicle clusters, and that overexpression of C9ORF72 isoform A or B rescues this phenotype (Supplementary Fig. 9c-g and Supplementary Videos 5-9). Clusters did not disperse over the time course of the assay, suggesting that they are relatively stable and not in rapid flux (Supplementary Videos 5-9). In addition, M6PR+ puncta moved with a slower average speed in C9ORF72 patient and C9ORF72+/− iMNs than controls (Supplementary Fig. 9h, i). Thus, reduced C9ORF72 levels lead to fewer lysosomes in motor neurons in vitro and in vivo, and this may be due in part to altered trafficking of M6PR+ vesicles.
Whole cell membrane potential and current recordings in voltage- and current-clamp configurations were made using an EPC9 patch clamp amplifier controlled with PatchMaster software (HEKA Electronics). Voltage- and current-clamp data was acquired at 50 kHz and 20 kHz, respectively, with a 2.9 kHz low-pass Bessel filter, while spontaneous action potential recordings were acquired at 1 kHz sampling frequency. For experiments, culture media was exchanged with warm extracellular solution consisting of (in mM): 140 NaCl, 2.8 KCl, 10 HEPES, 1 MgCl2, 2 CaCl2, and 10 glucose, with pH adjusted to 7.3 and osmolarity adjusted to 305 mOsm. Glass patch pipettes were pulled on a Narishige PC-10 puller and polished to 5–7 MΩ resistance. Pipettes were also coated with Sylgard 184 (Dow Corning) to reduce pipette capacitance. The pipette solution consisted of (in mM): 130 K-gluconate, 2 KCl, 1CaCl2, 4 MgATP, 0.3 GTP, 8 phosphocreatine, 10 HEPES, 11 EGTA, adjusted to pH 7.25 and 290 mOsm. Pipettes were sealed to cells in GΩ-resistance whole cell configuration, with access resistances typically between 10–20 MΩ, and leakage currents less than 50 pA. Capacitance transients were compensated automatically through software control. For voltage clamp, cells were held at −70 mV. For Current-voltage traces, a P/4 algorithm was used to subtract leakage currents from the traces. Measurements were taken at room temperature (approximately 20–25 °C). Data was analyzed and plotted in Igor Pro 6 (WaveMetrics) using Patcher’s Power Tools plug-in and custom programmed routines. Current density was obtained by dividing the measured ion channel current by the cell capacitance. For control iMNs, 10/10 tested fired action potentials. For C9-ALS iMNs, 9/10 tested fired action potentials.
Yingxiao Shi,#1,2,3 Shaoyu Lin,#1,2,3 Kim A. Staats,1,2,3 Yichen Li,1,2,3 Wen-Hsuan Chang,1,2,3 Shu-Ting Hung,1,2,3 Eric Hendricks,1,2,3 Gabriel R. Linares,1,2,3 Yaoming Wang,3,4 Esther Y. Son,5 Xinmei Wen,6 Kassandra Kisler,3,4 Brent Wilkinson,3 Louise Menendez,1,2,3 Tohru Sugawara,1,2,3 Phillip Woolwine,1,2,3 Mickey Huang,1,2,3 Michael J. Cowan,1,2,3 Brandon Ge,1,2,3 Nicole Koutsodendris,1,2,3 Kaitlin P. Sandor,1,2,3 Jacob Komberg,1,2,3 Vamshidhar R. Vangoor,7 Ketharini Senthilkumar,7 Valerie Hennes,1,2,3 Carina Seah,1,2,3 Amy R. Nelson,3,4 Tze-Yuan Cheng,8 Shih-Jong J. Lee,8 Paul R. August,9 Jason A. Chen,10 Nicholas Wisniewski,10 Hanson-Smith Victor,10 T. Grant Belgard,10 Alice Zhang,10 Marcelo Coba,3,11 Chris Grunseich,12 Michael E. Ward,12 Leonard H. van den Berg,13 R. Jeroen Pasterkamp,7 Davide Trotti,6 Berislav V. Zlokovic,3,4 and Justin K. Ichida1,2,3,†
Total RNA was extracted from sorted iMNs at day 21 post-transduction with Trizol RNA Extraction Kit (Life Technologies) and reverse transcribed with an Oligo dT primer using ProtoScript® II First Strand Synthesis Kit (NEB). RNA integrity was checked using the Experion system (Bio-Rad). Real-time PCR was performed with iTaq Universal SYBR Green Supermix (Bio-Rad) using primers shown in Supplementary Data Table 4.
CRISPR/Cas9-mediated genome editing was performed in human iPSCs as previously described, using Cas9 nuclease62. To generate loss-of-function alleles of C9ORF72, control iPSCs were transfected with a sgRNA targeting exon 2 of the C9ORF72 gene. Colonies were picked on day 7 after transfection and genotyped by PCR amplification and sequencing of exon 2. Colonies containing a frameshift mutation were clonally purified on MEF feeders and the resulting clones were re-sequenced to verify the loss-of-function mutation in C9ORF72.

To confirm that glutamate receptor levels were increased on the surface of C9ORF72+/− and C9ORF72 patient iMNs, we used CRISPR/Cas9 editing to introduce a Dox-inducible polycistronic cassette containing NGN2, ISL1, and LHX3 into the AAVS1 safe-harbor locus of control, C9ORF72+/− and C9ORF72 patient iPSCs. This enabled large-scale production of iMNs that expressed motor neuron markers and had transcriptional profiles similar to 7F iMNs (Supplementary Fig. 11). Using this approach, we quantified the amount of surface-bound NR1 by immunoblotting after using surface protein biotinylation to isolate membrane-bound proteins. This confirmed that surface NR1 levels were higher on C9ORF72+/− and C9ORF72 patient iMNs (n=2 patients) than controls (n=3 controls)(Fig. 4e-h, Supplementary Fig. 5g, h).
Hb9::RFP+ iMNs appeared between days 13–16 after retroviral transduction. RepSox was removed at day 17 and the survival assay was initiated. For the glutamate treatment condition, 10 µM glutamate was added to the culture medium on day 17 and removed after 12 hours. Cells were then maintained in N3 medium with neurotrophic factors without RepSox. For the glutamate treatment condition with glutamate receptor antagonists, cultures were co-treated with 10 μM MK801 and CNQX, and 2 μM Nimodipine during the 12 hour glutamate treatment. The antagonists were maintained for the remainder of the experiment. For the neurotrophic factor withdrawal condition, BDNF, GDNF, and CNTF were removed from the culture medium starting at day 17. Longitudinal tracking was performed by imaging neuronal cultures in a Nikon Biostation CT or Molecular Devices ImageExpress once every 24–72 hours starting at day 17. Tracking of neuronal survival was performed using SVcell 3.0 (DRVision Technologies). Neurons were scored as dead when their soma was no longer detectable by RFP fluorescence. All neuron survival assays were performed at least twice, with equal numbers of neurons from three individual replicates from one of the trials being used for the quantification shown. All trials quantified were representative of other trials of the same experiment. When iMNs from multiple independent donors are combined into one survival trace in the Kaplan-Meier plots for clarity, the number of iMNs tracked from each line can be found in Supplementary Table 5.
Importantly, our work establishes a new approach for suppressing DPR protein toxicity and blocking C9ORF72 pathogenesis: restoring or replacing C9ORF72 activity. Although high levels of C9ORF72 isoform A may have slightly detrimental effects on control motor neuron survival, we have only observed this in neurons without C9ORF72 repeat expansion. Thus, we would not anticipate a harmful effect of forced C9ORF72 expression in C9ORF72 patients. In addition, a better understanding of the effects of forced C9ORF72 expression could inform safe development of this therapeutic strategy. For example, determining if C9ORF72 accelerates turnover of DPR aggregates by stimulating autophagy could lead help to identify new therapeutic targets.
(a) Phenotypic screening for small molecules that enhance the survival of C9-ALS iMNs. (b) Chemical structure of the PIKFYVE inhibitors YM201636 and Apilimod, and a reduced-activity analog of Apilimod. (c) Live cell images of iMNs at day 7 of treatment with DMSO or YM201636 (scale bar: 1 mm). This experiment was performed 3 times with similar results. (d) Survival effect of scrambled or PIFKVYE ASOs on C9-ALS iMNs in excess glutamate. n=50 iMNs per condition, iMNs quantified from 3 biologically independent iMN conversions per condition. (e) Survival effect of Apilimod and the reduced-activity analog on C9-ALS patient iMNs with neurotrophic factor withdrawal. n=50 iMNs per condition, iMNs quantified from 3 biologically independent iMN conversions per condition. All iMN survival experiments in (d, e) were analyzed by two-sided log-rank test, and statistical significance was calculated using the entire survival time course. (f) Activities of therapeutic targets in C9ORF72 ALS. (g, h) The effect of 3 μM Apilimod on NMDA-induced hippocampal injury in control, C9orf72+/−, or C9orf72−/− mice. (Mean +/− s.e.m. of n=3 mice per condition, one-way ANOVA with Tukey correction across all comparisons, F-value (DFn, DFd): (3, 8)=43.55, AP = Apilimod, red dashed lines outline the injury sites). (i, j) The effect of 3 μM Apilimod on the level of GR+ puncta in the dentate gyrus of control or C9-BAC mice. Mean +/− s.d. of the number of GR+ puncta per cell, each data point represents a single cell. n=20 (wild-type + DMSO), 20 (wild-type + Apilimod), 87 (C9-BAC + DMSO), and 87 (C9-BAC + Apilimod) cells quantified from 3 mice per condition, one-way ANOVA with Tukey correction for all comparisons, F-value (DFn, DFd): (3, 180) = 16.29. Scale bars = 2 μm, dotted lines outline nuclei, and white arrows denote GR+ punctae (i). (k) Model for the mechanisms that cooperate to cause neurodegeneration in C9ORF72 ALS/FTD. Proteins in red are known to be mutated in ALS or FTD. iMN survival experiments in (d, e) were performed in a Molecular Devices ImageExpress.
Because C9ORF72 activity is required to maintain normal lysosomal function, we measured the effect of C9ORF72 activity on PR50 clearance by monitoring the clearance of PR50-Dendra2 fusion proteins in C9ORF72−/− iPSC-derived fibroblasts with or without exogenous C9ORF72. Dendra2 is a green fluorescent protein that irreversibly converts to red fluorescence when exposed to blue light, enabling quantification of its degradation 49. PR50-Dendra2 formed discrete punctae within cells, indicating that Dendra2 did not prevent intracellular aggregation of PR50 (Supplementary Fig. 14c). Expression of C9ORF72-T2A-GFP in C9ORF72−/− iPSC-derived fibroblasts significantly enhanced the decay of PR50-Dendra2 fluorescence over GFP alone (Supplementary Fig. 14d). To determine if C9ORF72 activity modulates DPR aggregate clearance in human motor neurons, we compared the decay of PR50-Dendra2 in C9ORF72+/+ and C9ORF72+/− iMNs (Fig. 5e and Suppementary Fig. 14e). Consistent with the hypothesis that C9ORF72 activity promotes DPR aggregate clearance, PR50-Dendra2 decayed significantly slower in C9ORF72+/− iMNs (Fig. 5e).
Hb9::RFP+ iMNs appeared between days 13–16 after retroviral transduction. RepSox was removed at day 17 and the survival assay was initiated. For the glutamate treatment condition, 10 µM glutamate was added to the culture medium on day 17 and removed after 12 hours. Cells were then maintained in N3 medium with neurotrophic factors without RepSox. For the glutamate treatment condition with glutamate receptor antagonists, cultures were co-treated with 10 μM MK801 and CNQX, and 2 μM Nimodipine during the 12 hour glutamate treatment. The antagonists were maintained for the remainder of the experiment. For the neurotrophic factor withdrawal condition, BDNF, GDNF, and CNTF were removed from the culture medium starting at day 17. Longitudinal tracking was performed by imaging neuronal cultures in a Nikon Biostation CT or Molecular Devices ImageExpress once every 24–72 hours starting at day 17. Tracking of neuronal survival was performed using SVcell 3.0 (DRVision Technologies). Neurons were scored as dead when their soma was no longer detectable by RFP fluorescence. All neuron survival assays were performed at least twice, with equal numbers of neurons from three individual replicates from one of the trials being used for the quantification shown. All trials quantified were representative of other trials of the same experiment. When iMNs from multiple independent donors are combined into one survival trace in the Kaplan-Meier plots for clarity, the number of iMNs tracked from each line can be found in Supplementary Table 5.
With the four components of a chemical heat pump (two solid-gas reactors, an evaporator and a condenser), a cycle of the double-effect type can be applied to continuous refrigeration. The performance of this process is analysed, allowing the infinite sink temperature and the couples of reactive salts to be used, which depend on the production temperature envisaged, to be selected. The results are ... [Show full abstract]Read more
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