Objective To establish a modeling method for an animal model simulating the decline of digestive function after a large amount of tissue necrosis of the pancreas due to acute injury after severe acute pancreatitis (SAP). Methods Twenty male SD rats were randomly divided into the model group and the sham operation group according to the random number table method, with 10 rats in each group. First, the SAP model was established by retrograde bile duct injection of sodium taurocholate in the model group, whereas the sham operation group received physiological saline injection. Fluid infusion began 2 hours later, twice a day, with an 8-hour interval, for 2 days. The traditional Chinese medicine Dachengqi Decoction without Decoction Granules was formulated into a suspension in proportion and administered by gavage once at 18 hours and once at 24 hours after the operation to ensure the blood volume of rats and reduce inflammatory damage. Normal drinking water was allowed 48 hours after modeling. After 72 hours, ordinary feed was given for feeding. The feeding lasted for 14 days (the total duration of the experiment was 17 days). The body weight, vitality status and stool characteristics of the rats were observed and recorded on the day of open feed feeding and 14 days later. Fourteen days after feeding, the animals were sacrificed and samples were collected for examination of blood glucose, fecal elastase and hematoxylin-eosin staining pathological scores. Results All 10 rats in the model group were successfully modeled with a 100% survival rate. The body weight of rats in the model group 14 days after ordinary feeding was lower than that on the day of open diet [(180.80±4.39) vs. (222.90±6.14) g, P<0.001], and lower than that of rats in the sham operation group 14 days later [(180.80±4.39) vs. (221.70±7.45) g, P<0.001]. Compared with the sham operation group, inflammatory cell infiltration injury still existed in the pancreatic tissue of the model group, and some pancreatic tissues showed pathologically related changes of chronic injury. The pathological score of the model group was higher than that of the sham operation group [7.5 (7, 9) vs. 0 (0, 0), P<0.001]; the blood glucose concentration increased [(13.000±1.531) vs. (8.070±0.851) mmol/L, P<0.001]. The secretion of fecal elastase, a metabolite of trypsin in vivo, was significantly decreased [(5.451±0.936) vs. (8.593±1.105) mg/mL, P<0.001]. Conclusion The use of short-term liquid supplementation, traditional Chinese medicine anti-inflammatory treatment, and early dietary stimulation can effectively combat early severe inflammatory damage in SAP, protect the life of model rats, and enable them to survive and experience digestive dysfunction, thus establishing an experimental animal model of digestive dysfunction in the late stage of SAP.
ObjectiveTo explored the effect of stromal cell-derived factor 1α (SDF-1α) on promoting the migration ability of rat adipose derived stem cells (rADSCs) by constructed the rADSCs overexpression SDF-1α via adenovirus transfection.MethodsrADSCs were isolated from adipose tissue of 6-week-old SPF Sprague Dawley rats. Morphological observation, multi-directional differentiations (osteogenic, adipogenic, and chondrogenic inductions), and flow cytometry identification were performed. Transwell cell migration experiment was used to observe and screen the optimal concentration of exogenous SDF-1α to optimize the migration ability of rADSCs; the optimal multiplicity of infection (MOI) of rADSCs was screened by observing the cell status and fluorescence expression after transfection. Then the third generation of rADSCs were divided into 4 groups: group A was pure rADSCs; group B was rADSCs co-cultured with SDF-1α at the best concentration; group C was rADSCs infected with recombinant adenovirus-mediated green fluorescent protein (Adv-GFP) with the best MOI; group D was rADSCs infected with Adv-GFP-SDF-1α overexpression adenovirus with the best MOI. Cell counting kit 8 (CCK-8) and Transwell cell migration experiment were preformed to detect and compare the effect of exogenous SDF-1α and SDF-1α overexpression on the proliferation and migration ability of rADSCs.ResultsThe cell morphology, multi-directional differentiations, and flow cytometry identification showed that the cultured cells were rADSCs. After screening, the optimal stimulating concentration of exogenous SDF-1α was 12.5 nmol/L; the optimal MOI of Adv-GFP adenovirus was 200; the optimal MOI of Adv-GFP-SDF-1α overexpression adenovirus was 400. CCK-8 method and Transwell cell migration experiment showed that compared with groups A and C, groups B and D could significantly improve the proliferation and migration of rADSCs (P<0.05); the effect of group D on enhancing the migration of rADSCs was weaker than that of group B, but the effect of promoting the proliferation of rADSCs was stronger than that of group D (P<0.05).ConclusionSDF-1α overexpression modification on rADSCs can significantly promote the proliferation and migration ability, which may be a potential method to optimize the application of ADSCs in tissue regeneration and wound repair.