Lineage reprogramming of fibroblasts into induced cardiac progenitor cells by CRISPR/Cas9-based transcriptional activators

Overexpression of exogenous lineage-determining factors succeeds in directly reprogramming fibroblasts to various cell types. Several studies have reported reprogramming of fibroblasts into induced cardiac progenitor cells (iCPCs). CRISPR/Cas9-mediated gene activation is a potential approach for cellular reprogramming due to its high precision and multiplexing capacity. Here we show lineage reprogramming to iCPCs through a dead Cas9 (dCas9)-based transcription activation system. Targeted and robust activation of endogenous cardiac factors, including GATA4, HAND2, MEF2C and TBX5 (G, H, M and T; GHMT), can reprogram human fibroblasts toward iCPCs. The iCPCs show potentials to differentiate into cardiomyocytes, smooth muscle cells and endothelial cells . Addition of MEIS1 to GHMT induces cell cycle arrest in G2/M and facilitates cardiac reprogramming. Lineage reprogramming of human fibroblasts into iCPCs provides a promising cellular resource for disease modeling, drug discovery and individualized cardiac cell therapy.

Studies on wnt5a inducing differentiation of cardiac progenitor cells to myocardial cells / 解放军医学杂志

Objective To investigate the effect of Wnt5a on inducing differentiation of Cp15-5a cell to myocardial cell.Methods Recombinant adenovirus wnt5a (Ad-wnt5a) and Ad-GFP was amplified with human embryo kidney 293 cells (HEK293 cells),and then transfected into CP15-5a cells and 3 experiment groups were set up:wnt5a group,GFP group and blank control group.Flow cytometry was used to detect the transfection efficiency of Ad-wnt5a and Ad-GFP.One week after transfection,the expressions of genes GATA binding protein 4 (GATA4) and myocardial enhancement factor 2C (MEF2C) were analyzed by realtime quantitative PCR (qRT-PCR).Two weeks after transfection,the expressions of cardiac-specific connexin 43 (Cx43) and cardiac troponin T (cTnT) in Ad-wnt5a-induced CP15-5a cells were detected by Western blotting and immunofluorescence techniques.The sodium current expression (INa) was detected by whole cell patch clamp techniques.Results The transfection efficiency of Ad-wnt5a and Ad-GFP was 42.8％ and 44.3％,respectively.One week after transduction,the expressions of GATA4 and MEF2C were significantly higher in wnt5a group (1.717 ± 0.220 and 1.847 ± 0.190) than in GFP group (1.003 ± 0.087 and 0.456 ± 0.042,P＜0.05) and blank control group (0.961 ± 0.063 and 0.500 ± 0.095,P＜0.05),while no significant difference existed between GFP group and blank control group.Two weeks after transduction,the expressions of CX43 and cTnT were significantly higher in wnt5a group (1.597 ± 0.267 and 0.727 ± 0.100) than in GFP group (0.723 ± 0.047 and 0.217 ± 0.021,P＜0.05) and blank control group (0.783 ± 0.1333 and 0.253 ± 0.102,P＜0.01),while no significant difference existed between GFP group and blank control group.INa was detected in the wnt5a group compared with GFP group and blank control group.Conclusion wnt5a may induce differentiation of cp 15-5a cell into myocardial cell.

Characteristics and Cardiomyogenic Potential of Rat Fetal Cardiac Progenitor Cells at Different Developmental Stage

In recent years, several kinds of cardiac progenitor cells have been identified and isolated from heart tissue. These cells showed differentiation potential into cardiomyocytes, smooth muscle cells, and endothelial cells in vitro and in vivo. Morphogenetic events are tightly regulated during development to determine cell destiny and reshape the embryonic lineage. In this study, we directly compared the characteristics of rat fetal cardiac progenitor cells (rFCPCs) isolated from the chamber formation stage at embryonic day 12 (E12) and at the septation stage of E15. Both kinds of rFCPCs expressed mesenchymal stem cell markers (CD105, CD73, and CD29) but not CD34 and CD45. The E12 rFCPCs expressed a high level of Oct4 compared to E15 until passage 5 and showed a steep decline of Nkx2.5 expression at passage 5. However, Nkx2.5 expression at E15 was maintained until passage 5 and Oct4 expression slightly increased at passage 5. We also detected an intense staining for Oct4 antibody in E12 heart tissue sections. The average doubling time of the E12 rFCPCs from passage 3 to passage 15 was about 5 hours longer than E15. These cells could also be induced into cardiomyocytes expressing α-MHC, cTnT, cTnC, and Cx43 under cardiomyogenic culture conditions and rFCPCs at E15 showed more intense staining of α-MHC than cells at E12 by immunocytochemistry. Taken together, our results show that developmental differences between E12 and E15 may influence their properties and differentiation. Furthermore those differences should be considered when deciding on the optimal cell source for cell replacement therapy in cardiovascular regeneration.

CPC derivedexosome protects cardiomyocytes from oxidative stress / 中国药理学通报

Aim To explore the anti-apoptotic function of cardiac progenitor cells(CPCs)-derived exosome in vitro.Method CPCs were isolated from mouse heart using Magnetic Cell Sorting(MACS)system.Flow Cy-tometry(FC)determine the purity of stem cell surface antigen-1 positive(Sca-1 +)CPCs.Exosome was puri-fied from conditional medium,and confirmed by West-ern blot using CD63 as a marker,Nanoparticle Traffic-king Analysis(NTA)was used to detect the diameters and concentration of exosome.Then the cells were di-vided into control groups and CPC-exosome pre-protec-tion groups.H2 O2 was added into H9c2 cells to induce oxidative stress.Western blot was adopted to determine the expression of cleaved caspase-3.Results ① Im-munofluorescence showed that CPCs isolated by MACS were positively expressing Sca-1 protein;FC analysis showed that typical purity of Sca-1 +CPCs from the first preparations was more than 95%.② WB demonstrated that CD63 of exosome isolated from CCMwas positively expressed,and NTA results showed that the diameters of exosome were (82.33 ±3.06)nm(n =3).Micro-scope detected PKH-26 labeled exosome appeared in the cytoplasma of H9c2 cells.③ Western blot showed the CPC-exosome pre-protection groups significantly down-regulated the levels of cleaved caspase-3 com-pared to the control groups(P <0.05).Conclusion CPC can secrete exosome which carries many important cargos,which can effectively gather in H9c2 cells. CPC-exosome can protect H9c2 cells from the oxidative stress induced by H2 O2 .Our results highlight a new perspective strategy for cardiac disease.