ObjectiveTo investigate effect of heart tissue-derived extracellular matrix(ECM) on the differentiation, proliferation and apoptosis of cardiosphere-derived cells(CDC) in vitro. MethodsCDCs were cultured by cardiac explant methods. ECM was prepared by decelluariztion procedure. CDCs were cultured on ECM coated dishes or conventional fibrin (FN) coated dishes. Then we compared the differentiation rate, proliferation, and apoptosis rate of CDC between the two groups in vitro. ResultsECM could significantly promote CDC differentiating into vascular endothelial cell, cardiac muscle cell or smooth muscle cell (0.060±0.002 vs. 0.043±0.002, P < 0.001; 0.082±0.003 vs. 0.051±0.002, P < 0.001; 0.055±0.002 vs. 0.034±0.001, P < 0.001). ECM also significantly promoted the proliferation of CDC and reduced the apoptosis and necrosis rate of CDC in vitro (0.052±0.002 vs. 0.025±0.001, P < 0.001). ConclusionWe obtained c-kit+ CDCs, effectively remove the cellular components of heart tissue-derived ECM and preserved the composition and structure of ECM. ECM can promote the differentiation of CDC to vascular endothelial cell, cardiac muscle cell or smooth muscle cell, promote the proliferation of CDCs and decrease CDC apoptosis and necrosis rate in vitro.
ObjectiveTo establish a novel animal model of deep hypothermic circulatory arrest (DHCT) in rabbits without thoracotomy, and investigate acute kidney injury (AKI) induced by DHCT and early novel biomarkers of AKI. MethodsForty-two New Zealand big ear rabbits (3.5-4.0 kg, male or female) were randomly divided into 2 groups with 21 rabbits in each group. Cardiopulmonary bypass (CPB) was established via the right carotid artery and jugular vein in both groups. In Group A, CPB continued when the rectal temperature was maintained at 28℃. In group B, DHCT started when the rectal temperature reached 16℃ to 18℃ and lasted for 60 minutes before CPB was resumed and rewarming was started. The rectal temperature was restored to 35℃ within 30 minutes, then CPB was maintained for 30 minutes. CPB time was same in both groups. Preoperatively and 6 hours, 24 hours and 48 hours after the operation, venous blood samples were taken to examine serum creatinine (Cr) and β-trace protein (β-TP), and urine samples were taken to examine neutrophil gelatinase-associated lipocalin (NGAL). Four rabbits were sacrificed at respective above time points to measure renal malondialdehyde (MDA) content. Hematoxylin-Eosin (HE) staining, TUNEL assay and transmission electron microscopy were used to examine morphological changes of renal tubular epithelial cells (TECs). ResultsFour rabbits died in group A and five rabbits died in Group B during the experiment.(1)Blood Cr:There was no statistical difference between different time points in Group A (P > 0.05). In Group B, serum Cr at 24 hours after the operation was significantly higher than other time points, and also significantly higher than that of group A (P < 0.05).(2)Blood β-TP and urinary NGAL:There was no statistical difference between different time points in Group A (P > 0.05). In Group B, blood β-TP and urinary NGAL at the time of 6 hours, 24 hours and 48 hours postoperatively were significantly higher than preoperative levels (P < 0.05). Blood β-TP and urinary NGAL at the time of 24 hours postoperatively were significantly higher than other time points (P < 0.05). Blood β-TP and urinary NGAL at the time of 6 hours, 24 hours and 48 hours postoperatively were significantly higher than those of group A (P < 0.05).(3)Renal MDA content of Group B at the time of 24 hours postoperatively was significantly higher than other time points as well as that of Group A (P < 0.05).(4) HE staining showed serious pathological injuries of renal TECs at the time of 24 hours postoperatively in Group B. There was no significant pathological injury of renal TECs at the time of 24 hours postoperatively in Group A. (5)TUNEL-positive rate of group B at the time of 24 hours postoperatively was significantly higher than other time points as well as that of group A (P < 0.05).(6)Transmission electron microscope showed serious pathological injuries of renal TECs organelles at the time of 24 hours postoperatively in Group B. There was no significant pathological injury of renal TECs organelles in Group A. ConclusionsThis DHCT rabbit model without thoracotomy is a simple, convenient, and economical animal model with long-term animal survival for the study of DHCT-induced organ injury. AKI is most serious at the time of 24 hours after DHCA. Blood β-TP and urinary NGAL can be used as early biomarkers of DHCT-induced AKI.
ObjectiveTo explore the inhibition action of valproic acid to inflammatory cells and smooth muscle cells then to find out that valproic acid (VPA) can repress rat thoracic aortic aneurysm or not. MethodsThe model of rat thoracic aortic aneurysm was built through the method of soaking the adventitia of artery using porcine pancreatic elastase (PPE). The rats were divided into three groups:a normal saline blank control group (a C group), an adventitia soaked PPE group (a P group), and adventitia soaked PPE plus intraperitoneal injection by injecting intraperitioneal VPA 200 mg/kg for seven days (a PV group).The animals of the three groups were all using vascular ultrasound to detect blood vessel diameter. Animals were killed after operation to observe the general morphology of vascular aneuysm and do the immunohistochemial, morphological, protein analysis of interleukin 1 (IL-1), interleukin 6 (IL-6), smooth muscle 22 alpha (SM22α), matrix metallopeptidase 2 (MMP-2), MMP-9 and Western blot by drawing animals on the 14th day. ResultsThe vessels diameter in the PV group was narrower than that in the P group (P value<0.05). HE staining, immunohistochemistry and Western blot displayed that the cells in the P group were in disorder arrangement and interstitial disorder while the cells in the PV group maintained better albumin layer. The protein expressions of IL-1, IL-6, MMP-2, and MMP-9 in the PV group decreased except that SM22α increased. ConclusionVPA can inhibit phenothpic transforming of aneurysm inflammatory cells and smooth muscle cells, reduce the levels of cell proliferation, decrease the secretion of matrix metalloproteinases, and depress tumor growth of rat thoracic aorta.