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.
Structured illumination microscopy (SIM) images were acquired using a Zeiss Elyra PS.1 system equipped with a 100X 1.46 NA or 63X 1.4NA objective. Acquisition was performed with PCO edge sCMOS camera and image reconstruction was done with built-in structured illumination model. Confocal microscopy images were acquired using Zeiss LSM800 microcopy with 63X 1.4NA objective or Zeiss LSM780 microcopy with 40X 1.1NA objective. Z stack images were done with a step size of 2.5 um. Further image process was done with Fiji.

Therapeutic strategies in development for C9ORF72 ALS/FTD target gain-of-function mechanisms. These include ASOs 6–8 and small molecules 13 that disrupt RNA foci formation. However, these approaches have not fully rescued neurodegeneration in human patient-derived neurons 6–8,13, indicating that replacing C9ORF72 function or new therapeutic targets may be required.


To measure the effect of dipeptide repeat protein expression on iMN survival, PR50 and GR50 were cloned into the pHAGE lentiviral vector as fusions with GFP to allow tracking of protein expression. iMN cultures were transduced with PR50 and GR50 lentiviruses at day 17 of reprogramming and longitudinal survival analysis was started the same day. 10 ng/ml of GDNF, BDNF, and CNTF was maintained throughout the experiment, and glutamate treatment was not performed. To measure PR50 turnover, PR50 was cloned into the pHAGE lentiviral vector as a fusion with Dendra2 (Addgene). iPSC-derived fibroblasts were generated according to Daley and colleagues64. Briefly, when C9ORF72−/− iPSC cultures reached 80% confluence, the medium was switched from mTeSR1 (Stem Cell Technologies) to human fibroblast medium containing DMEM (Life Technologies), 10% fetal bovine serum (FBS)(Thermo Fisher Scientific), and 1% penicillin/streptomycin (Life Technologies). Cells were passaged 2 to 3 times using Accutase (Life Technologies) before use in experiments. iPSC-derived fibroblasts were transduced with either pMXs-eGFP or pMXs-C9ORF72 isoform B-T2A-eGFP retrovirus and treated with 10 μg/ml mitomycin C for 3 hrs to inhibit cell proliferation. The cells were then transduced with the PR50–Dendra2 lentivirus and exposed to blue light for 1.5 sec using a lumencor LED light source to initiate photoconversion. The amount of decay (as a fraction of the starting level) of the red fluorescent punctae was monitored by longitudinal time lapse imaging in a Molecular Devices ImageExpress and analyzed using SVCell 2.0 (DRVision Technologies). Fluorescence was quantified at t = 0 and 12 hours after photoconversion. Distinct photoconverted punctae were treated as discrete objects for analysis (n = 20 each for +eGFP and +C9ORF72-T2A-eGFP). For each object, background fluorescence was subtracted and fluorescence was normalized according to object size. The fractional decay was statistically analyzed by two-tailed Student’s t-test. ** - p<.01.

Brand serves as commitment, as trust and as standard. It is the voting of the customers for a company and the natural sifter for customers to tell the good from the bad. Xuerong is convinced that quality is what comprises the brand. During the last 15 years we have cautiously and conscientiously created a brand channel partners and customers can trust. Today Xuerong can proudly claim that it is the leading role in edible mushroom and the market can also admit and prove our effort by higher value.
Samples were first fixed in 4% PFA (1x PBS) overnight at 4°C and were subsequently washed three times with 1x PBS. Next, cells were permeabilized with 0.3% Triton X-100 (1x PBS) for 10 min at room temperature, followed by three washes with 1x PBS for 10 min each. After permeabilization, the samples were equilibrated in 1x SSC buffer for 10 min at room temperature and then transferred into 50% formamide (2x SSC) for 10 min at 60°C. The repeat expansion-targeting probe and the negative control probe were ordered from Exiqon 58. During this step, the probe mixture (1µl salmon sperm (10 µg/µl), 0.5 µl E. coli tRNA (20 µg/µl), 0.4 µl probe (25 µM), 25 µl 80% formamide/per sample) was made and placed at 95°C for at least 10 min. The samples were submerged in 200 µl of hybridization buffer (4ml 100% formamide, 0.5 ml 20x SSC, 1 ml BSA fraction V, 0.5ml RVC (20 mM), 1ml NaPO4 (0.1 M), 3 ml nuclease-free water) and 27 µl of the probe mixture was added to each sample and incubated for 1 hour at 60°C. After probe hybridization, the samples were washed twice with 50% formamide (2x SSC) for 20 min each at 65°C and once more with 40% formamide (1x SSC) for 10 min at 60°C. The remaining formamide was removed by briefly washing with 1x SSC three times. A final crosslinking step was performed by first incubating the samples with 1x Tris-Glycine for 5 minutes followed by a 5 min incubation in 4% PFA. Samples were washed three times with 1x PBS, stained with DAPI, and imaged using a Zeiss LSM 800 confocal microscope.
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.

Brand serves as commitment, as trust and as standard. It is the voting of the customers for a company and the natural sifter for customers to tell the good from the bad. Xuerong is convinced that quality is what comprises the brand. During the last 15 years we have cautiously and conscientiously created a brand channel partners and customers can trust. Today Xuerong can proudly claim that it is the leading role in edible mushroom and the market can also admit and prove our effort by higher value.
To verify that PIKFYVE-dependent modulation of vesicle trafficking was responsible for rescuing C9ORF72 patient iMN survival, we tested the ability of a constitutively active RAB5 mutant to block C9ORF72 patient iMN degeneration. Active RAB5 recruits PI3-kinase to synthesize PI3P from PI and therefore, like PIKFYVE inhibition, increases PI3P levels 56. Constitutively active RAB5 did not improve control iMN survival (n=2 controls)(Supplementary Fig. 15k), but successfully rescued C9ORF72 patient iMN survival (n=3 patients)(Supplementary Fig. 15l). In constrast, dominant negative RAB5, wild-type RAB5, or constitutively active RAB7 did not rescue C9ORF72 patient iMN survival (n=1, 3, 3 patients, respectively)(Supplementary Fig. 14m-o).
×