ABSTRACT
Tissue-specific differentiation is driven by specialized transcriptional networks. Pancreatic acinar cells crucially rely on the PTF1 complex, and on additional transcription factors, to deploy their transcriptional program. Here, we identify NFIC as a novel regulator of acinar differentiation using a variety of methodological strategies. NFIC binding sites are found at very short distances from NR5A2-bound genomic regions and both proteins co-occur in the same complex. Nfic knockout mice show reduced expression of acinar genes and, in ChIP-seq experiments, NFIC binds the promoters of acinar genes. In addition, NFIC binds to the promoter of, and regulates, genes involved in RNA and protein metabolism; in Nfic knockout mice, p-RS6K1 and p-IEF4E are down-regulated indicating reduced activity of the mTOR pathway. In 266-6 acinar cells, NFIC dampens the ER stress program through its binding to ER stress gene promoters and is required for complete resolution of Tunicamycin-mediated ER stress. Normal human pancreata from subjects with low NFIC mRNA levels display reduced epxression of genes down-regulated in Nfic knockout mice. Consistently, NFIC displays reduced expression upon induced acute pancreatitis and is required for proper recovery after damage. Finally, expression of NFIC is lower in samples of mouse and human pancreatic ductal adenocarcinoma and Nfic knockout mice develop an increased number of mutant Kras-driven pre-neoplastic lesions.
Competing Interest Statement
The authors have declared no competing interest.
Footnotes
Conflicts of interest: none to declare
Funding: This work was supported, in part, by grants SAF2011-29530, SAF2015-70553-R, and RTI2018-101071-B-I00 from Ministerio de Ciencia, Innovación y Universidades (Madrid, Spain) (co-funded by the ERDF-EU) and RTICC from Instituto de Salud Carlos III (RD12/0036/0034) to FXR. IC was recipient of a Beca de Formación del Personal Investigador from Ministerio de Economía y Competitividad (Madrid, Spain). The research leading to these results has received funding from People Programme (Marie Curie Actions) of the European Union’s Seventh Framework Programme (FP7/2007- 2013) (REA grant agreement n° 608765”). SP was supported by a Juan de la Cierva Programme fellowship from Ministerio de Ciencia, Innovación y Universidades. IM was supported by a Fellowship from Fundació Bancaria La Caixa (ID 100010434) (grant number LCF/BQ/ES18/11670009). CNIO is supported by Ministerio de Ciencia, Innovación y Universidades as a Centro de Excelencia Severo Ochoa SEV-2015-0510.
SP: acquisition of data; analysis and interpretation of data; drafting of the manuscript
JMA: acquisition of data; analysis and interpretation of data; drafting of the manuscript
AT: acquisition of data; analysis and interpretation of data;
JMV: analysis and interpretation of data;
FG: acquisition of data; analysis and interpretation of data;
IM: analysis and interpretation of data;
NdP: technical support and acquisition of data; JCP: material support;
RJM: critical revision of the data and important intellectual content;
JM: acquisition of data; analysis and interpretation of data;
FXR: study concept and design; analysis and interpretation of data; drafting of the manuscript; overall study supervision; obtained funding.
All authors provided input about manuscript content.
Accession numbers: RNA sequencing data have been deposited in GEO with accession number GSE126907 and NFIC ChIP sequencing data have been deposited in GEO with accession number GSE181098
Abbreviations
- ChIP
- chromatin immunoprecipitation
- DEG
- differentially expressed genes
- EMT
- epithelial-mesenchymal transition
- ER
- endoplasmic reticulum
- GSEA
- Gene set enrichment analysis
- IF
- immunofluorescence
- IHC
- immunohistochemistry
- PDAC
- pancreatic ductal adenocarcinoma
- TF
- transcription factor
- TM
- tunicamycin
- UPR
- unfolded protein response