FIGURE 5.

GDF11‐mediated OPA1 processing depends on YME1L. A, Representative TEM images of MSCs transfected with siRNA‐OPA1 or siRNA‐YME1L for 48 hours and then incubated with rGDF11 (50 ng/mL) for 24 hours and then exposed to hypoxia conditions for 48 hours (×10 000). Scale bars: 1 μm. B, C, Quantification of mitochondrial area, longitudinal length and size distribution according to their length: long tubules (>0.65 μm), intermediate (≤0.65 μm, ≥0.32 μm), and fragmented (<0.32 μm) (n = 105 for MSC^si‐NC, n = 64 for MSCs^{si‐NC + rGDF11}, n = 123 for MSC^si‐OPA1, n = 68 for MSC^{si‐OPA1 + rGDF11}, n = 93 for MSC^si‐YME1L, and n = 96 for MSC^{si‐YME1L + rGDF11}). D, Representative immunoblots and densitometric quantification for the expression of YME1L and OMA1 under normoxic and hypoxic conditions (n = 4). E, mRNA levels of YME1L and OMA1 in MSCs^Ctrl and MSCs^rGDF11, and 18 seconds served as control. F, Western blot analysis of YME1L and OPA1. YME1L and L‐OPA1 were quantified and presented as relative level by comparing with β‐actin control (n = 3). G, Intracellular ATP levels in MSCs at specified conditions were determined. ATP levels was calibrated with protein content (n = 3). Data were shown as mean ± SD. *P < .05 vs si‐NC