RESUMEN
This article has been retracted; see accompanying Retraction Note, which can be accessed via a link at the top of the paper.
RESUMEN
Maintenance of cell type identity is crucial for health, yet little is known of the regulation that sustains the long-term stability of differentiated phenotypes. To investigate the roles that key transcriptional regulators play in adult differentiated cells, we examined the effects of depletion of the developmental master regulator PTF1A on the specialized phenotype of the adult pancreatic acinar cell in vivo Transcriptome sequencing and chromatin immunoprecipitation sequencing results showed that PTF1A maintains the expression of genes for all cellular processes dedicated to the production of the secretory digestive enzymes, a highly attuned surveillance of unfolded proteins, and a heightened unfolded protein response (UPR). Control by PTF1A is direct on target genes and indirect through a ten-member transcription factor network. Depletion of PTF1A causes an imbalance that overwhelms the UPR, induces cellular injury, and provokes acinar metaplasia. Compromised cellular identity occurs by derepression of characteristic stomach genes, some of which are also associated with pancreatic ductal cells. The loss of acinar cell homeostasis, differentiation, and identity is directly relevant to the pathologies of pancreatitis and pancreatic adenocarcinoma.
Asunto(s)
Células Acinares/citología , Perfilación de la Expresión Génica/métodos , Páncreas Exocrino/citología , Factores de Transcripción/genética , Transcripción Genética , Células Acinares/metabolismo , Animales , Diferenciación Celular , Regulación de la Expresión Génica , Técnicas de Inactivación de Genes , Homeostasis , Ratones , Páncreas Exocrino/metabolismo , Desplegamiento Proteico , Análisis de Secuencia de ARN/métodos , Factores de Transcripción/metabolismo , Respuesta de Proteína DesplegadaRESUMEN
Reprogramming of pancreatic exocrine cells into cells resembling beta cells may provide a strategy for treating diabetes. Here we show that transient administration of epidermal growth factor and ciliary neurotrophic factor to adult mice with chronic hyperglycemia efficiently stimulates the conversion of terminally differentiated acinar cells to beta-like cells. Newly generated beta-like cells are epigenetically reprogrammed, functional and glucose responsive, and they reinstate normal glycemic control for up to 248 d. The regenerative process depends on Stat3 signaling and requires a threshold number of Neurogenin 3 (Ngn3)-expressing acinar cells. In contrast to previous work demonstrating in vivo conversion of acinar cells to beta-like cells by viral delivery of exogenous transcription factors, our approach achieves acinar-to-beta-cell reprogramming through transient cytokine exposure rather than genetic modification.
Asunto(s)
Factor Neurotrófico Ciliar/administración & dosificación , Diabetes Mellitus/tratamiento farmacológico , Factor de Crecimiento Epidérmico/administración & dosificación , Células Secretoras de Insulina/efectos de los fármacos , Células Acinares/efectos de los fármacos , Células Acinares/patología , Animales , Diferenciación Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Factor Neurotrófico Ciliar/genética , Diabetes Mellitus/genética , Factor de Crecimiento Epidérmico/genética , Hiperglucemia/tratamiento farmacológico , Células Secretoras de Insulina/patología , Ratones , Ratones Endogámicos NOD/genética , Transducción de SeñalRESUMEN
The prospective white matter (PWM) in the nascent cerebellum contains a transient germinal compartment that produces all postnatally born GABAergic inhibitory interneurons and astrocytes. However, little is known about the molecular identity and developmental potential of resident progenitors or key regulatory niche signals. Here, we show that neural stem-cell-like primary progenitors (Tnc(YFP-low) CD133(+)) generate intermediate astrocyte (Tnc(YFP-low) CD15(+)) precursors and GABAergic transient amplifying (Ptf1a(+)) cells. Interestingly, these lineally related but functionally divergent progenitors commonly respond to Sonic hedgehog (Shh), and blockade of reception in TNC(YFP-low) cells attenuates proliferation in the PWM, reducing both intermediate progenitor classes. Furthermore, we show that Shh produced from distant Purkinje neurons maintains the PWM niche independently of its classical role in regulating granule cell precursor proliferation. Our results indicate that Purkinje neurons maintain a bidirectional signaling axis, driving the production of spatially and functionally opposed inhibitory and excitatory interneurons important for motor learning and cognition.