Chronic pancreatitis (CP) is characterized by pancreatic inflammation, fibrosis, and abdominal pain that is challenging to treat. Mesenchymal stromal cells (MSCs) overexpressing human alpha-1 antitrypsin (hAAT-MSCs) showed improved mobility and protective functions over native MSCs in nonobese diabetic mice. We investigated whether hAAT-MSCs could mitigate CP and its associated pain using trinitrobenzene sulfonic acid (TNBS)-induced CP mouse models. CP mice were given native human MSCs or hAAT-MSCs (0.5 × 106 cells/mouse, i.v., n = 6–8/group). The index of visceral pain was measured by graduated von Frey filaments. Pancreatic morphology and pancreatic mast cell count were analyzed by morphological stains. Nociceptor transient receptor potential vanilloid 1 (TRPV1) expression in dorsal root ganglia (DRG) was determined by immunohistochemistry. hAAT-MSC-treated CP mice best preserved pancreatic morphology and histology. MSC or hAAT-MSC infusion reduced abdominal pain sensitivities. hAAT-MSC therapy also suppressed TRPV1 expression in DRG and reduced pancreatic mast cell density induced by TNBS. Overall, hAAT-MSCs reduced pain and mitigated pancreatic inflammation in CP equal to MSCs with a trend toward a higher pancreatic weight and better pain relief in the hAAT-MSC group compared to the MSC group. Both MSCs and hAAT-MSCs might be used as a novel therapeutic tool for CP-related pain.
Low-dose aspirin (LDA) is efficacious in preventing preeclampsia, but its mechanism of action is unclear. Conflicting evidence suggests that it may inhibit placental trophoblast release of soluble fms-like tyrosine kinase-1 (sFlt1), a key mediator of preeclampsia. We examined whether, and at what concentrations, aspirin and its principal metabolite, salicylic acid, modulate sFlt1 release and/or expression in trophoblasts. Human trophoblast lines BeWo and HTR-8/SVneo were cultured; BeWo cells were also treated with 1% oxygen vs. normoxia to mimic hypoxia in preeclamptic placentas. Cells were treated with aspirin or salicylic acid vs. vehicle for 24 h at concentrations relevant to LDA and at higher concentrations. Protein concentrations (ELISA) and mRNA expression (RT-PCR) of sFlt1 were determined. Under normoxia, LDA-relevant concentrations of aspirin (10–50 µmol/L) or salicylic acid (20–100 µmol/L) had no significant effect on sFlt1 protein release or mRNA expression in BeWo cells. However, inhibition was observed at higher concentrations (1 mmol/L for aspirin and ≥200 μmol/L for salicylic acid). Hypoxia enhanced sFlt1 protein release and mRNA expression in BeWo cells, but these responses were not significantly affected by either aspirin or salicylic acid at LDA concentrations. Similarly, neither drug altered sFlt1 protein secretion or mRNA expression in normoxic HTR-8/SVneo cells at LDA concentrations. We suggest that direct modulation of trophoblast release or expression of sFlt1 is unlikely to be a mechanism underlying the clinical efficacy of LDA in preeclampsia.