scholarly journals SOX9 inactivation affects the proliferation and differentiation of human lung organoids

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Lian Li ◽  
Jianqi Feng ◽  
Shanshan Zhao ◽  
Zhili Rong ◽  
Ying Lin

Abstract Background The regulation of the transcription factor sex-determining region Y-box transcription factor 9 (SOX9) in lung development has been described in mouse, but the same principles apply to human lung development is unknown due to a lack of appropriate experimental approaches and models. Methods Here, we used gene editing technology to inactivate SOX9 in human embryonic stem cells that were then induced to differentiate into lung organoids to investigate the role of SOX9 in human lung epithelium development. Results Complete knockout of the transactivation domain of SOX9 by gene editing resulted in indels in both alleles of SOX9. SOX9−/− hESCs could be induced to differentiate into lung progenitor organoids. In vitro long-term expansion showed that SOX9 inactivation did not affect the differentiation of pulmonary epithelial cells, but promoted apoptosis and reduced proliferative capacity in the organoids. When lung progenitor organoids were transplanted under the kidney capsule of immunodeficient mice, expression of the club cell marker secretoglobin family 1A member 1 (SCGB1A1) was detected in SOX9−/− transplants but was absent in wild-type (WT) transplants. The maturation of goblet cells was also affected by SOX9 inactivation, as evidenced by the presence of mucin 5 AC (MUC5AC) in the cytoplasm of SOX9−/− grafts as compared to WT grafts in which most MUC5AC was secreted into the lumen. In vivo lung orthotopic transplantations showed that SOX9 inactivation had a limited effect on the differentiation of alveolar cells and lung regeneration in injured mice. Conclusions SOX9 modulates the proliferative capacity of lung epithelium but is not an indispensable transcription factor in the regulation of human lung epithelium development.

1997 ◽  
Vol 17 (3) ◽  
pp. 1642-1651 ◽  
Author(s):  
M J Weiss ◽  
C Yu ◽  
S H Orkin

The zinc finger transcription factor GATA-1 is essential for erythropoiesis. In its absence, committed erythroid precursors arrest at the proerythroblast stage of development and undergo apoptosis. To study the function of GATA-1 in an erythroid cell environment, we generated an erythroid cell line from in vitro-differentiated GATA-1- murine embryonic stem (ES) cells. These cells, termed G1E for GATA-1- erythroid, proliferate as immature erythroblasts yet complete differentiation upon restoration of GATA-1 function. We used rescue of terminal erythroid maturation in G1E cells as a stringent cellular assay system in which to evaluate the functional relevance of domains of GATA-1 previously characterized in nonhematopoietic cells. At least two major differences were established between domains required in G1E cells and those required in nonhematopoietic cells. First, an obligatory transactivation domain defined in conventional nonhematopoietic cell transfection assays is dispensable for terminal erythroid maturation. Second, the amino (N) zinc finger, which is nonessential for binding to the vast majority of GATA DNA motifs, is strictly required for GATA-1-mediated erythroid differentiation. Our data lead us to propose a model in which a nuclear cofactor(s) interacting with the N-finger facilitates transcriptional action by GATA-1 in erythroid cells. More generally, our experimental approach highlights critical differences in the action of cell-specific transcription proteins in different cellular environments and the power of cell lines derived from genetically modified ES cells to elucidate gene function.


Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 776-776
Author(s):  
Zhongfa Yang ◽  
Alan G. Rosmarin

Abstract GABP is an ets transcription factor that regulates transcription of key myeloid genes, including CD18 (beta2 leukocyte integrin), neutrophil elastase, lysozyme, and other key mediators of the inflammatory response; it is also known to regulate important cell cycle control genes. GABP consists of two distinct and unrelated proteins that, together, form a functional transcription factor complex. GABPalpha (GABPa) is an ets protein that binds to DNA; it forms a tetrameric complex by recruiting its partner, GABPbeta (GABPb), which contains the transactivation domain. GABPa is a single copy gene in both the human and murine genomes and it is the only protein that can recruit GABPb to DNA. We cloned GABPa from a murine genomic BAC library and prepared a targeting vector in which exon 9 (which encodes the GABPa ets domain) was flanked by loxP (floxed) recombination sites. The targeting construct was electroporated into embryonic stem cells, homologous recombinants were implanted into pseudopregnant mice, heterozygous floxed GABPa mice were identified, and intercrossing yielded expected Mendelian ratios of wild type, heterozygous, and homozygous floxed GABPa mice. Breeding of heterozygous floxed GABPa mice to CMV-Cre mice (which express Cre recombinase in all tissues) yielded expected numbers of hemizygous mice (only one intact GABPa allele), but no nullizygous (GABPa−/−) mice among 64 pups; we conclude that homozygous deletion of GABPa causes an embryonic lethal defect. To determine the effect of GABPa deletion on myeloid cell development, we bred heterozygous and homozygous floxed mice to LysMCre mice, which express Cre only in myeloid cells. These mice had a normal complement of myeloid cells but, unexpectedly, PCR indicated that their Gr1+ myeloid cells retained an intact (undeleted) floxed GABPa allele. We detected similar numbers of in vitro myeloid colonies from bone marrow of wild type, heterozygous floxed, and homozygous floxed progeny of LysMCre matings. However, PCR of twenty individual in vitro colonies from homozygous floxed mice indicated that they all retained an intact floxed allele. Breeding of floxed GABPa/LysMCre mice with hemizygous mice indicated that retention of a floxed allele was not due to incomplete deletion by LysMCre; rather, it appears that only myeloid cells that retain an intact GABPa allele can survive to mature in vitro or in vivo. We prepared murine embryonic fibroblasts from homozygous floxed mice and efficiently deleted GABPa in vitro. We found striking abnormalities in proliferation and G1/S phase arrest. We used quantitative RT-PCR to identify mechanisms that account for the altered growth of GABPa null cells. We found dramatically reduced expression of known GABP target genes that regulate DNA synthesis and cell cycle that appear to account for the proliferative defect. We conclude that GABPa is required for growth and maturation of myeloid cells and we identified downstream targets that may account for their failure to proliferate and mature in vitro and in vivo.


2004 ◽  
Vol 24 (13) ◽  
pp. 5844-5849 ◽  
Author(s):  
Sika Ristevski ◽  
Debra A. O'Leary ◽  
Anders P. Thornell ◽  
Michael J. Owen ◽  
Ismail Kola ◽  
...  

ABSTRACT The ETS transcription factor complex GABP consists of the GABPα protein, containing an ETS DNA binding domain, and an unrelated GABPβ protein, containing a transactivation domain and nuclear localization signal. GABP has been shown in vitro to regulate the expression of nuclear genes involved in mitochondrial respiration and neuromuscular signaling. We investigated the in vivo function of GABP by generating a null mutation in the murine Gabpα gene. Embryos homozygous for the null Gabpα allele die prior to implantation, consistent with the broad expression of Gabpα throughout embryogenesis and in embryonic stem cells. Gabpα+/− mice demonstrated no detectable phenotype and unaltered protein levels in the panel of tissues examined. This indicates that Gabpα protein levels are tightly regulated to protect cells from the effects of loss of Gabp complex function. These results show that Gabpα function is essential and is not compensated for by other ETS transcription factors in the mouse, and they are consistent with a specific requirement for Gabp expression for the maintenance of target genes involved in essential mitochondrial cellular functions during early cleavage events of the embryo.


eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Samuel A Myers ◽  
Sailaja Peddada ◽  
Nilanjana Chatterjee ◽  
Tara Friedrich ◽  
Kiichrio Tomoda ◽  
...  

The transcription factor SOX2 is central in establishing and maintaining pluripotency. The processes that modulate SOX2 activity to promote pluripotency are not well understood. Here, we show SOX2 is O-GlcNAc modified in its transactivation domain during reprogramming and in mouse embryonic stem cells (mESCs). Upon induction of differentiation SOX2 O-GlcNAcylation at serine 248 is decreased. Replacing wild type with an O-GlcNAc-deficient SOX2 (S248A) increases reprogramming efficiency. ESCs with O-GlcNAc-deficient SOX2 exhibit alterations in gene expression. This change correlates with altered protein-protein interactions and genomic occupancy of the O-GlcNAc-deficient SOX2 compared to wild type. In addition, SOX2 O-GlcNAcylation impairs the SOX2-PARP1 interaction, which has been shown to regulate ESC self-renewal. These findings show that SOX2 activity is modulated by O-GlcNAc, and provide a novel regulatory mechanism for this crucial pluripotency transcription factor.


2006 ◽  
Vol 26 (3) ◽  
pp. 1109-1123 ◽  
Author(s):  
Daniela S. Bassères ◽  
Elena Levantini ◽  
Hongbin Ji ◽  
Stefano Monti ◽  
Shannon Elf ◽  
...  

ABSTRACT The leucine zipper family transcription factor CCAAT enhancer binding protein alpha (C/EBPα) inhibits proliferation and promotes differentiation in various cell types. In this study, we show, using a lung-specific conditional mouse model of C/EBPα deletion, that loss of C/EBPα in the respiratory epithelium leads to respiratory failure at birth due to an arrest in the type II alveolar cell differentiation program. This differentiation arrest results in the lack of type I alveolar cells and differentiated surfactant-secreting type II alveolar cells. In addition to showing a block in type II cell differentiation, the neonatal lungs display increased numbers of proliferating cells and decreased numbers of apoptotic cells, leading to epithelial expansion and loss of airspace. Consistent with the phenotype observed, genes associated with alveolar maturation, survival, and proliferation were differentially expressed. Taken together, these results identify C/EBPα as a master regulator of airway epithelial maturation and suggest that the loss of C/EBPα could also be an important event in the multistep process of lung tumorigenesis. Furthermore, this study indicates that exploring the C/EBPα pathway might have therapeutic benefits for patients with respiratory distress syndromes.


1992 ◽  
Vol 12 (12) ◽  
pp. 5620-5631 ◽  
Author(s):  
B Shan ◽  
X Zhu ◽  
P L Chen ◽  
T Durfee ◽  
Y Yang ◽  
...  

The retinoblastoma protein interacts with a number of cellular proteins to form complexes which are probably crucial for its normal physiological function. To identify these proteins, we isolated nine distinct clones by direct screening of cDNA expression libraries using purified RB protein as a probe. One of these clones, Ap12, is expressed predominantly at the G1-S boundary and in the S phase of the cell cycle. The nucleotide sequence of Ap12 has features characteristic of transcription factors. The C-terminal region binds to unphosphorylated RB in regions similar to those to which T antigen binds and contains a transactivation domain. A region containing a potential leucine zipper flanked by basic residues is able to bind an E2F recognition sequence specifically. Expression of Ap12 in mammalian cells significantly enhances E2F-dependent transcriptional activity. These results suggest that Ap12 encodes a protein with properties known to be characteristic of transcription factor E2F.


2015 ◽  
Vol 35 (6) ◽  
pp. 1014-1025 ◽  
Author(s):  
Arvind Shakya ◽  
Catherine Callister ◽  
Alon Goren ◽  
Nir Yosef ◽  
Neha Garg ◽  
...  

The mechanisms whereby the crucial pluripotency transcription factor Oct4 regulates target gene expression are incompletely understood. Using an assay system based on partially differentiated embryonic stem cells, we show that Oct4 opposes the accumulation of local H3K9me2 and subsequent Dnmt3a-mediated DNA methylation. Upon binding DNA, Oct4 recruits the histone lysine demethylase Jmjd1c. Chromatin immunoprecipitation (ChIP) time course experiments identify a stepwise Oct4 mechanism involving Jmjd1c recruitment and H3K9me2 demethylation, transient FACT ( fa cilitates c hromatin t ransactions) complex recruitment, and nucleosome depletion. Genome-wide and targeted ChIP confirms binding of newly synthesized Oct4, together with Jmjd1c and FACT, to the Pou5f1 enhancer and a small number of other Oct4 targets, including the Nanog promoter. Histone demethylation is required for both FACT recruitment and H3 depletion. Jmjd1c is required to induce endogenous Oct4 expression and fully reprogram fibroblasts to pluripotency, indicating that the assay system identifies functional Oct4 cofactors. These findings indicate that Oct4 sequentially recruits activities that catalyze histone demethylation and depletion.


Cell Reports ◽  
2021 ◽  
pp. 109055
Author(s):  
Apoorva Mulay ◽  
Bindu Konda ◽  
Gustavo Garcia ◽  
Changfu Yao ◽  
Stephen Beil ◽  
...  

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