Fig. 1
KMP restores mitochondria impairments and inhibits ER stress in C9ORF72 neurons. a Seahorse graph plotted for oxygen consumption rate (OCR) on y-axis with time on X-axis. Representative traces of mitochondrial respiration from Ctrl(1) and C9(1) iMNs, showing mitochondrial functional deficits in C9ORF72 patient line at one week, but those deficits are normalized after KMP treatment. b Mitochondrial oxygen consumption rate analysis on iMNs reveals impairments in basal respiration in all three C9ORF72 patient lines compared to healthy control or respective isogenic control. Basal respiration is restored to control level after KMP treatment (Unpaired t-test: CNTRL (1) vs C9 (1) ***; CNTRL (1) vs C9 (1) + KMP n.s.; CNTRL (2) vs C9 (2) ***; CNTRL (2) vs C9 (2) + KMP n.s.; Iso-C9 (3) vs C9 (3) *; Iso-C9 (3) vs C9 (3) + KMP *). The experiment was performed in triplicates from three different batches of iPSC conversion to iMNs. c Mitochondria OCR analysis on iMNs reveals impairments in ATP production in all C9ORF72 patient lines compared to healthy control or respective isogenic. ATP production is restored to the control level after KMP treatment (Unpaired t-test: CNTRL (1) vs C9 (1) **; CNTRL (1) vs C9 (1) + KMP * CNTRL (2) vs C9 (2) ***; CNTRL (2) vs C9 (2) + KMP *; Iso-C9 (3) vs C9 (3) *; Iso-C9 (3) vs C9 (3) + KMP n.s.). Experiment was performed in triplicates from three iPSC batches converted to iMNs . d Schematic depiction of the experimental timeline for iMNs TU treatment and TU treatment combined with 24 h of KMP. e Representative confocal images of BiP immunostaining in iMNs, quantitative analysis revealed an increase in BiP expression after 24 h TU treatment, whereas ER stress was completely inhibited after TU + KMP treatment. (Unpaired t-test: CNTRL (1–2) vs C9 (1.2) n.s. Iso-C9 (3) vs C9 (3) n.s.; CNTRL (1–2) vs CNTRL (1–2) + TU***; C9 (1–2) vs C9 (1–2) + TU***; Iso-C9 (3) vs Iso-C9 (3) + TU ***; C9 (3) vs C9 (3) + TU ***; CNTRL (1–2) + TU vs CNTRL (1–2) + TU + KMP ***; C9 (1–2) + TU vs C9 (1–2) + TU + KMP***; Iso-C9 (3)) + TU vs Iso-C9 (3)) + TU + KMP ***; C9 (3) + TU vs C9 (3) + TU) + KMP***). Scale bars: 100 μm. f CNTRL and C9 iMNs treated with TU displayed significant cell death, whereas the addition of KMP for 24 h was found to be neuroprotective (TU: CNTRL (1) 41% alive vs 59% dead; C9 (1) 45% alive vs 55% dead; C9 (2) 35% alive vs 65% dead; TU + KMP: CNTRL (1) 96% alive vs 4% dead; C9 (1) 93% alive vs 7% dead; C9 (2) 81% alive vs 19% dead). Scale bars: 10 μm. g Schematic depiction of the experimental timeline for dNs generation, TU treatment and TU treatment combined with 24 h of KMP. h CNTRL and C9 dNs treated with TU displayed significant cell death, whereas those treated with KMP for 24 h were resilient to ER stress-induced neurodegeneration