Supplementary Figure 11: Functional characterization of SANLPCs generated from the HES2 hPSC line.
(a) Representative recordings of spontaneous action potentials in a HES2 hPSC-derived (HES2) SANLPC and VLCM. (b) Histogram plot showing the distribution of the maximum upstroke velocities (dV/dtmax) recorded in HES2 SANLPCs and VLCMs. (c) Current-voltage relationship for pacemaker funny current (If) densities and summary of maximum If densities recorded at -120 mV in HES2 VLCMs and SANLPCs. t-test: **P < 0.01 vs VLCMs. (d,e) ECG recordings and optical mapping in the Langendorff isolated rat heart model harvested 14 days after transplantation with HES2 SANLPCs (1.25x106 cells). The SANLPC graft evoked isolated ectopic beats during induction of pharmacological AV block. Original ECG traces (d) and optical mapping derived activation maps (e) are shown after the application of Adenosine (0.6 mg). The orange circle in the far left image indicates the site of the HES2 SANLPC transplant (TP). Scale bar represents 5 mm. Note, the presence of premature beats (indicated by * in the ECG trace) between the sinus rhythm beats. These premature beats map to the HES2 SANLPC transplantation site. (f,g) ECG recordings and optical mapping in the Langendorff isolated rat heart model, harvested 14 days after transplantation with HES2 VLCMs (1.5x106 cells). Original ECG traces (f) and optical mapping derived activation maps (g) are shown before and after the application of 0.1 ml Methacholine (1 μM) + Lidocaine (0.005%) for induction of transient AV block. The black circle in the far left image indicates the site of the HES2 VLCM transplant (TP). Scale bar represents 5 mm. (h-i) VLCM and SANLPC graft size determined by qPCR using primers specific to human ALU repeat elements at 2 weeks after transplantation presented as percentage of graft cell survival (h) and total number of engrafted cells (i). Error bars represent s.e.m.
