Background: Activated pancreatic stellate cells (PSC) play an important role in chronic pancreatitis to exacerbate fibrosis and increase the risk of pancreatic cancer. Systemic dysregulation of glucose metabolism, increased rates of obesity and type II diabetes are rising at an alarming pace in the Western world. Hyperinsulinemia and glucose intolerance associated with these disorders may have a variety of deleterious effects on the pancreas, an organ with a vital role to regulate glucose in the whole body. However, the extent to which these effects involve PSC has not been determined. Methods: we analyzed the expression of insulin/ IGF-1 signaling pathway components and their operation as profibrotic and/or proliferative pathways within a novel immortalized human pancreatic stellate cell line (ihPSC) and assessed the potential contributions of these cells to a procarcinogenic microenvironment. Results: ihPSC express receptors for both insulin (IR) and insulin-like growth factor 1 (IGF-1R), and respond to insulin/IGF-1 stimulation with increased tyrosine phosphorylation at specific autophosphorylation sites. Whereas routine culture conditions (DMEM/F12 supplemented with 10% FBS) maintained constitutive tyrosine autophosphorylation of IR/IGF-1R, and activity of ERK1/2 and Akt pathways, serum starvation (24 h in fresh medium without FBS) diminished the Akt Ser473 and Thr308 phosphorylation to ,20% of basal. In serum-starved PSC, insulin at 100 nM induced peak stimulation of Akt phosphorylation that remained elevated at levels of 5-8 fold above basal from 10 min to at least 1 h. IGF-1 at 10 nM also produced peak stimulation, maximally at 10 min. Whereas the basal level of ERK1/2 phosphorylation was high even in serum-starved cells, stimulation with either 100 nM insulin or 10 nM IGF-1 produced transient increases which peaked at approximately 3 min. Interestingly, we also found effects of different culture conditions on mRNA and protein expression of IR/IGF-1R β subunits. In particular, in cells grown to 50% confluence and then shifted to physiologic glucose level (5 mM), marked enhancement of IGF-1R expression levels was exhibited within 24 h, as assessed by Western blot analysis. Also under these conditions, ihPSC express galectin-1, galectin-3 and IGF-1 ligand, and insulin/IGF-1 stimulation enhanced fibronectin production. Interestingly, whereas low glucose was associated with a sustained enhancement in IR/IGF-1R β subunit as well as IGF-1 mRNA expression, exposure to a hyperglycemic condition (25 mM glucose) with or without insulin appeared to destabilize these mRNA and protein expression levels. Conclusions: our data support a role of insulin/IGF-1 in PSC proliferative and profibrotic signaling and suggest that hyperglycemia/ hyperinsulinemia negatively modulate responsiveness to, as well as production of, IGF-1 in PSC.