High-mobility group box-1 peptide ameliorates bronchopulmonary dysplasia by suppressing inflammation and fibrosis in a mouse model.

BACKGROUND: This study aimed to examine the effect of the HMGB1 peptide on Bronchopulmonary dysplasia (BPD)-related lung injury in a mouse model. RESULTS: HMGB1 peptide ameliorates lung injury by suppressing the release of inflammatory cytokines and decreasing soluble collagen levels in the lungs. Single-cell RNA sequencing showed that the peptide suppressed the hyperoxia-induced inflammatory signature in macrophages and the fibrotic signature in fibroblasts. These changes in the transcriptome were confirmed using protein assays. CONCLUSION: Systemic administration of HMGB1 peptide exerts anti-inflammatory and anti-fibrotic effects in a mouse model of BPD. This study provides a foundation for the development of new and effective therapies for BPD.

Highly efficient biallelic genome editing of human ES/iPS cells using a CRISPR/Cas9 or TALEN system.

Genome editing research of human ES/iPS cells has been accelerated by clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) and transcription activator-like effector nucleases (TALEN) technologies. However, the efficiency of biallelic genetic engineering in transcriptionally inactive genes is still low, unlike that in transcriptionally active genes. To enhance the biallelic homologous recombination efficiency in human ES/iPS cells, we performed screenings of accessorial genes and compounds. We found that RAD51 overexpression and valproic acid treatment enhanced biallelic-targeting efficiency in human ES/iPS cells regardless of the transcriptional activity of the targeted locus. Importantly, RAD51 overexpression and valproic acid treatment synergistically increased the biallelic homologous recombination efficiency. Our findings would facilitate genome editing study using human ES/iPS cells.

Hepatocyte Nuclear Factor 4 Alpha Promotes Definitive Endoderm Differentiation from Human Induced Pluripotent Stem Cells.

Hepatocyte nuclear factor 4 alpha (HNF4α) is a key transcription factor for liver development. Although HNF4α is necessary for hepatoblast differentiation, the function of HNF4α before the hepatoblast differentiation, such as in definitive endoderm differentiation, is not well known. In addition, it is known that there are nine HNF4α isoforms, but the expression and function of each HNF4α isoform during the definitive endoderm differentiation is also not clear. In this study, we examined the expression pattern of HNF4α and its functions in the definitive endoderm differentiation from human induced pluripotent stem (iPS) cells. We found that the HNF4α-1D isoform expression levels were significantly increased during the definitive endoderm differentiation, while the HNF4α-1A isoform expression levels did not change. Therefore, we further examined the function of the HNF4α-1D isoform in definitive endoderm differentiation. HNF4α-1D overexpression or knockdown was found to promote or prevent the definitive endoderm differentiation, respectively. Interestingly, Lefty1 was directly regulated by HNF4α-1D, and Lefty1 knockdown also prevented the definitive endoderm differentiation. These results suggest that HNF4α-1D promotes definitive endoderm differentiation through the regulation of Lefty1. To our knowledge, this is the first report to clarify the expression pattern and function of HNF4α during the definitive endoderm differentiation.