Related Experiment Videos
Pancreatic reg gene expression is inhibited during cellular differentiation
M E Zenilman1, T H Magnuson, R Perfetti
1Department of Surgery, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
Background And Objective:
Factors that control pancreatic regenerating (reg I) gene expression are unknown, but it is believed that its expression may correspond with cellular differentiation. The authors recently demonstrated that reg I is expressed in AR42J, a rat acinar cell line whose state of differentiation can be modulated by dexamethasone. They used this line to study reg I expression during cellular proliferation and differentiation.
Methods:
After treatment of cells with 10 nmol/L dexamethasone, proliferation was assayed by thymidine incorporation; differentiation by expression of elastase I mRNA. Reg I mRNA levels were measured using a rat reg I cDNA probe, and reg I protein levels assayed by enzyme-linked immunosorbent assay of cellular lysates with a polyclonal antibody. The effect of gastrin, cholecystokinin and glucagon on reg I expression was also studied.
Results:
When compared with controls, treatment with dexamethasone caused thymidine incorporation to decrease and elastase mRNA levels to increase. Reg I mRNA decreased from controls of 100 +/- 16% to 40 +/- 18% (p < 0.05), and reg I protein levels decreased as well. Gastrointestinal hormones had no significant effect on either elastase or reg I gene expression.
Conclusions:
Expression of reg I inversely correlates with the level of cellular differentiation, can be modulated via the glucocorticoid receptor, and is a potential marker of gastrointestinal epithelial differentiation. Despite its presence within a pancreatic acinar cell line, reg I gene expression is not modulated by gastrointestinal hormones.
Insights
Pancreatic regenerating (reg I) gene expression inversely correlates with cellular differentiation. Dexamethasone treatment reduced reg I levels, indicating its potential as a marker for gastrointestinal epithelial differentiation.
Area of Science:
- Molecular Biology
- Cell Biology
- Gastroenterology
Background:
- Pancreatic regenerating (reg I) gene expression regulation is not fully understood.
- Reg I gene expression is hypothesized to correlate with cellular differentiation.
- The AR42J rat acinar cell line, whose differentiation is modulated by dexamethasone, was used to study reg I expression.
Purpose of the Study:
- To investigate the factors controlling pancreatic regenerating (reg I) gene expression.
- To determine the relationship between reg I gene expression, cellular proliferation, and differentiation in the AR42J cell line.
- To assess the effect of gastrointestinal hormones on reg I expression.
Main Methods:
- AR42J cells were treated with dexamethasone (10 nmol/L).
- Cell proliferation was measured by thymidine incorporation.
- Cellular differentiation was assessed by elastase I mRNA expression.
- Reg I mRNA and protein levels were quantified using cDNA probes and ELISA, respectively.
- The impact of gastrin, cholecystokinin, and glucagon was evaluated.
Main Results:
- Dexamethasone treatment decreased cell proliferation (thymidine incorporation) and increased differentiation (elastase I mRNA).
- Reg I mRNA levels decreased significantly (from 100% to 40%) following dexamethasone treatment.
- Reg I protein levels also showed a decrease.
- Gastrointestinal hormones did not significantly alter elastase or reg I gene expression.
Conclusions:
- Reg I gene expression is inversely correlated with the level of cellular differentiation.
- Glucocorticoid receptor modulation affects reg I expression.
- Reg I serves as a potential marker for gastrointestinal epithelial differentiation.
- Reg I gene expression in pancreatic acinar cells is not modulated by gastrointestinal hormones.