Table 1.
Reference | Cell Source | Reprogramming Factors | Markers of iCMs, Percentages | Spontaneous Beating/When | Comments | |
---|---|---|---|---|---|---|
[15] | MCFs, TTFs | Starting with 14 F: GMT best | αMHC-GFP + TropT (FACS, day 7) | MCFs: yes, after 4–5 weeks (rare events) | No CPC stage | |
MCFs: | GMT: ~4%–6% | |||||
TTFs: | GMT: ~2.5% | |||||
[22] | aMCFs, aTTFs | H2GMT | αMHC-GFP + TropT (FACS) | aMCFs: yes, after 5 weeks (rare events) aTTFs: yes, after 5 weeks (rare events) | – | |
aTTFs (day 9): | GMT: ~2.9% | |||||
aMCFs (day 7): | GMT: ~1.4% | |||||
[23] | aMCFs, aTTFs | GMT | αMHC-GFP; Nkx2.5-GFP (FACS, day 21): no GFP+ cells | No beating | no CPC stage (Nkx2.5-GFP) | |
[21] | MEFs (E13.5, w/o head, w/o visceral organs, p3–p5) MCFs (aMHC-tdTomato mice: Thy1+, tdTomato-) TTFs (3-day-old mice) | MTMc | MEFs: for initial qRT-PCR screening | MCFs: no, after 4 weeks (only rare events which were considered as cardiomyocyte contamination) | – | |
αMHC-tdTomato (FACS, day 14) | ||||||
MCFs: | GMT: 2.2% ± 0.2% | |||||
TTFs: | GMT: 2.4% ± 0.2% | |||||
TropT (FACS, day 14) | ||||||
MCFs: | GMT: 12% ± 3.7% | |||||
[24] | MCFs | miR-1, miR-133, miR-208, miR-499 + JI1 | αMHC-CFP (FACS, day 7) | MCFs: yes, after 10 days (rare events 1%–2% of total cell population) | short CPC stage: Mesp2 from day 1–5 (miR-1, -133, -208, -499); no pluripotency marker detected (Oct4, Nanog) | |
negmiR: 0.1%–3.9% | ||||||
[25] | MEFs (E14.5, w/o head, w/o visceral organs, w/o heart, p3–p5) aMCFs (8–10-week-old mice), isolation by culture, p3 | NH2GMT | TropT-GCaMP (Ca2+ oscillation, day 14) | MEFs: yes, after day 14 | iCMs not proliferative (Ki67) | |
MEFs: | GMT: 0.03% ± 0.02% | |||||
MCFs: | NH2GMT: 4.5% ± 0.3% | |||||
[26] | MEFs (E13) | MpScMcSfNH1H2GTM | αMHC-GFP (FACS, day 7) | N.A. | – | |
NegCtr: 0.03% ± 0.05% | ||||||
[27] | MEFs (E14.5, w/o head, w/o visceral organs, w/o heart), p3–p5 aMCFs (8–10-week-old mice), isolation by culture, p3 | NH2GMT + small molecules (SB) | TropT-GCaMP (Ca2+ oscillation, day 14) | MEFs: robust beating, after day 11 aMCFs: yes, after day 16 | TGFβ signaling pathway plays a role in conversion | |
MEFs: | NH2GMT + DMSO: 5.0% ± 1.8% | |||||
aMCFs: | NH2GMT + DMSO: 1.5% ± 0.4% | |||||
[9] | MEFs (E12.5, w/o head, w/o visceral organs) aMCFs (adult αMHC-GFP mice; Thy1+ GFP−) | GMT + miR133 | αMHC-GFP (FACS, day 7) | MEFs: GMT: yes, after 4 weeks; GMT + miR133: yes, after 10 days aMCFs: N.A. | iCMs not proliferative (EdU assay) Snai1/EMT mechanism no Mesp1+ CPCs (Mesp1-Cre x Stop-GFP mouse MEFs) mainly atrial-type myocytes | |
MEFs: | GMT: ~19%; GMT + miR133: ~33% | |||||
TropT (FACS, day 7) | ||||||
MEFs: | GMT: ~1.9%; GMT + miR133: ~12% | |||||
[28] | MEFs, TTFs, MCFs | 20 F H2GMT | Hcn4-GFP (FACS, day 7) | No (due to inadequate sarcomeric protein expression and organization, 12 weeks of culture) 0.0%–0.16% of H2GMT transduced fibroblasts show spontaneous beating (no further specification) | No Nkx2.5+ CPCs; well organized sarcomeric structures necessary for spontaneous beating, H2GMT: different types of CMs (atrial, pacemaker, and ventricular) | |
TTFs: | 20F: 15%; | |||||
[29] | MCFs (1.5 day old mice), TTFs | GMT (polycistronic vector, different order) | αMHC-GFP or TropT (FACS, day 10) | MCFs: MGT: yes, after 3 weeks | Stoichiometry is of critical importance (especially high Mef2c levels) | |
MCFs: | G + M + T: ~5% (GFP), ~0.2% (TropT) | |||||
[30] CASD approach | MEFs, TTFs | OSKMy + cytokines + small molecules | Nebulette-LacZ: initial screening | MEFs: yes, after day 11 TTFs: yes, after day 12 beating patches generated per 100,000 cells on day 18 MEFs: 145 ± 6 TTFs: 115 ± 7 | CPC stage: on day 9–10 (Flk1, Nkx2.5, Gata4) day 11: only atrial CMs only Mlc2a not Mlc2v | |
MEFs: OSK + JI1 (day 1–day 9) + BMP4 (day 9–day 14): N.A. | ||||||
TropT (FACS, day 18) | ||||||
TTFs: OSKM + JI1 (day1–day9) + BMP4 (day 9–day 14), 39% ± 2% | ||||||
[31] CASD approach | MEFs (E13.5, w/o head, w/o visceral organs, w/o heart), TTFs | Oct4 + small molecules (SCPF) + BMP4 | Beating cluster (day 30) | MEFs: yes, after day 20 TTFs: yes | CPC stage mostly ventricular iCMs (Mlc2v) | |
MEFs: 99 ± 17 per 10,000 starting cells | ||||||
TTFs: ~50 per 10,000 starting cells |
Abbreviations: iCMs, induced cardiomyocytes; CASD, Cell-Activation and Signaling-Directed; Cell Source, MEFs: murine embryonic fibroblasts; MCFs, murine cardiac fibroblasts; TTFs, tail-tip fibroblasts; a, adult; w/o, without; p, passage; Reprogramming Factors, F: factors; O, Oct4; S, Sox2; K, Klf4; My, c-Myc; H2, Hand2; N, Nkx2.5; G, Gata4; G6, Gata6; M, Mef2c; T, Tbx5; T3, Tbx3; Mc, Myocardin; Mp, Mesp1; Sc, Smarcd3 (Baf60c); Sf, SRF; H1, Hand1; E, ESRRG; Z, ZFPM2; R, Rxra; JI1, JAK inhibitor JI1; BMP4, bone morphogenic protein 4; SB, SB431542 (TGFβ-inhibitor); S, SB431542 (ALK4/5/7 inhibitor); C, CHIR99021 (GSK3 inhibitor); P, parnate (LSD1/KDM1 inhibitor); F, forskolin (adenylyl cyclase activator); Comments: CPC, cardiac progenitor cell. N.A., not available; bold text, markers for iCMs and used cell sources.