Objective To review the expression of mechano-growth factor (MGF) and its roles in tissue repairs andregeneration. Methods The l iterature about the expression of MGF and its roles in tissue repairs and regeneration in recentyears was reviewed. Results MGF is sensitive to mechanical stimulation and can be expressed in various tissues/cells. MGF isresponsible for satell ite cell activation, myoblast proliferation, and plays important roles in the treatment of muscle coloboma,prevention of myocardial injury, and neuroprotection. Conclusion The important role of MGF in tissue repairs andregeneration has been identified, however, the detailed mechanisms remain unclear up to now and still need a further study.
Objective To explore the possible mechanism of nerve growth factor (NGF) mixed insul in on the angiogenesis of burn wounds and the effect on the expressions of Bcl-2 and Bax in diabetic rats. Methods A total of 75 SPF male Wistar rats, weighing 200-220 g, were selected randomly and divided into nomal control (group A, n=15), the rats with diabetic control (group B, n=15), insul in treatment (group C, n=15), NGF treatment (group D, n=15), NGF and insul in treatment (group E, n=15) groups. In groups B, C, D, and E, streptozotocin was given by intraperitoneal injection at dose of 10 mg/kg on the 1st day and 50 mg/kg on the 3rd day to prepare the diabetic rat models. In group A, citric acid buffer at the samedose was given. After 1 month of diabetic models, second degree scald was made on the back of the rats, and then wounds were treated with 3-layer normal sal ine gauze in groups A and B, with 3-layer gauze containing 5 U Novol in 30R and subcutaneous injection of Novol in 30R (4-6 U/kg) everyday in group C, with 3-layer gauze containing 5 mL NGF (25 U/mL) in group D, and with a combination of groups C and D in group E. At 7, 11, 15, and 21 days, the wound heal ing rate was calculated; at 3, 7, 11, 15, and 21 days, the expressions of Bcl-2, Bax, and CD34 were determined and the microvascular density was measured by immunohistochemistry staining. Results All rats survived till experiment was finished. The area of wounds became smaller gradually with time. Group E was better than other groups in the wound heal ing rate (P lt; 0.05), the skin keratosis, the hair growth, and the granulation tissue and collagen fibers growth. With time, the expressions of CD34 and Bcl-2 increased gradually, reached the peak at 15 days and decreased at 21 days; the expression was ber in group E than in other groups (P lt; 0.05). At 3 days, Bax did not express; at 7 days, Bax began to express in new vascular endothel ial cells and the expression increased gradually with time; the expression was weaker in group E than in other groups (P lt; 0.05). Conclusion A combination of NGF and insul in local appl ication can enhance the angiogenesis of the burn wound in diabetic rats and accelerate wound heal ing by increasing the expression of Bcl-2 and decreasing the expression of Bax and restraining apoptosis of the wounds vascular endothel ial cells of diabetic rats.
To isolate and culture adi pose-derived stem cells (ADSCs), and to study the effects of the conditioned medium of ADSCs (ADSC-CM) treated with insul in on HaCaT cells. Methods ADSCs were isolated from adipose tissue donated by the patient receiving abdominal surgery and were cultured. The concentration of ADSCs at passage 3 was adjusted to 5 × 104 cells/mL. The cells were divided into 2 groups: group A in which the cells were incubated in 1 × 10-7 mol/ Linsul in for 3 days, and group B in which the cells were not treated with insul in. ADSC-CM in each group was collected 3 days after culture, then levels of VEGF and hepatocyte growth factor (HGF). HaCaT cells were cultured and the cells at passage 4 were divided into 4 groups: group A1, 0.5 mL 2% FBS and 0.5 mL ADSC-CM from group A; group B1, 0.5 mL 2% FBS and 0.5 mL ADSC-CM from group B; group C1, 1 mL 2% FBS of 1 × 10-7 mol/ L insul in; group D1, 1 mL 2%FBS. Prol iferation of HaCaT cells was detected by MTT method 3 days after culture, apoptosis rate of HaCaT cells was measured by Annexin V-FITC double staining 12 hours after culture, and the migration abil ity was measured by in vitro wound-heal ing assay 0, 12, 24, 36 and 48 hours after culture. Results The level of VEGF in groups A and B was (643.28 ± 63.57) and (286.52 ± 46.68) pg/mL, respectively, and the level of HGF in groups A and B was (929.95 ± 67.52) and (576.61 ± 84.29) pg/mL, respectively, suggesting differences were significant between two groups (Plt; 0.05). Cell prol iferation detection showed the absorbance value of HaCaT cells in group A1, B1, C1 and D1 was 0.881 ± 0.039, 0.804 ± 0.041, 0.663 ± 0.027 and 0.652 ± 0.042, respectively, suggesting there was significant difference between groups A1 and B1 and groups C1 and D1 (P lt; 0.01), group A1 was significantly higher than group B1 (P lt; 0.05). The apoptosis rate of HaCaT cells in groups A1, B1, C1 and D1 was 5.23% ± 1.98%, 8.82% ± 2.59%, 31.70% ± 8.85% and 29.60% ± 8.41%, respectively, indicating there was significant difference between groups A1 and B1 and groups C1 and D1 (P lt; 0.05), group B1 was significantly higher than group A1 (P lt; 0.05). The migration distance of HaCaT cells in groups A1, B1,C1 and D1 at 36 hours was (0.184 6 ± 0.019 2), (0.159 8 ± 0.029 4), (0.059 2 ± 0.017 6) and (0.058 2 ± 0.012 3) mm, respectively, whereas at 48 hours, it was (0.231 8 ± 0.174 0), (0.205 1 ± 0.012 1), (0.079 2 ± 0.008 1) and (0.078 4 ± 0.011 7) mm, respectively, suggesting there were significant differences between groups A1 and B1 and groups C1 and D1 at 36 and 48 hours (P lt; 0.01), group A1 was significantly higher than group B1 (P lt; 0.05) at 36 and 48 hours, no significant difference was evident at other time points(P gt; 0.05). Conclusion ADSCs treated with insul in can significantly promote the prol iferation and the migration of HaCaT cells and inhibit their apoptosis.
【Abstract】 Objective To explore good methods for isolation and purification of rat islets. Methods The isletswere isolated from male SD rat pancreata by a collagenase perfusion method and purified by a modified method: added 4 kinds of Euro-Ficoll of different densities (F1: D=1.132, F2: D=1.108, F4: D=1.069, F5: D=1.023), discontinuous density gradient centrifuge the tube at 2 000 r/min for 20 minutes at 4℃ , then the islets between F1 and F2 were collected. The purity of islets was assessed by dithizone staining with islets counted and scored for size. Islets viabil ity was assessed by fluorescin diacetate / propidium iodide. The function of purified islets was judged by the test of insul in release and islets transplantation. Results After an improved method for optimized isolation and purification, (920±122) IEQ purified islets were obtained from one rat. Both the purity and viabil ity of islets were over 90%. The amount of insul in secretion was (18.25±0.32) mU/L and (36.70±3.57) mU/Lat 2.2 mmol/ L and 22.2 mmol/L concentration of glucose respectively, there was significant difference between the two phases(P lt; 0.05). The insul in release index was 2.01±0.15. Under 1 000 IEQ islets transplantation, the normal glucose level could beremained in diabetic rats. Conclusion High purity and high viabil ity islet cells can be got through improved collagenase perfusion and centrifugation on gradients method.
Objective To investigate the effect of topical appl ication of insul in on the burn wound heal ing in aging diabetes mell itus (DM) rats and to explore its mechanism. Methods Seventy-five SPF Wistar rats (female and/or male), aged 12-24 months and weighing 300-350 g, were selected and randomly divided into group A (burn control group, n=25), group B(DM burn control group, n=25), and group C (DM insul in treatment group, n=25). The rats in group B and group C were fedwith high-fat, high-protein, and high-sugar forage for 1 month and received intraperitoneal injection of streptozotocin (STZ)to establ ish experimental model of aging DM. The rats were fed with high-fat, high-protein, and high-sugar forage for another 8 weeks. Then, the deep second-degree burn model was establ ished in the rats of group B and group C. The wounds in group A and B underwent local subcutaneous injection of 2 mL isotonic sal ine and group C received local subcutaneous injection of 0.1 U insul in. The rate of wound heal ing was calculated 7, 14, and 21 days after burn injury. At 1, 3, 7, 14, and 21 days after burn injury, HE staining observation, immunohistochemistry staining for CD34, detection of sugar and hydroxyprol ine (HOP) content in wound tissue, and microvessel density (MVD) calculation were performed. Results At 7, 14, and 21 days after burn injury, the wound heal ing rates of group A and group C was significantly higher than that of group B (P lt; 0.05), and there was no significant difference between group A and group C (P gt; 0.05). Histology observation at 21 days after burn injury: in group A, certain degree of epithel ization was evident in the wound epithel ium; in group B, large quantity of necrotic tissue was evident; in group C, complete epithl ization occurred in the wound epithel ium with better epithel ial cell differentiation and more neonatal collagen. For the sugar content in the wound tissue, group A was significantly lower than group B or group C at 1, 3, 7, 14, and 21 days (P lt; 0.05) and group C was significantly lower than group B at 7, 14, and 21 days (P lt; 0.05). For the HOP content in the wound tissue and the MVD count, group A or group C was significantly higher than group B (P lt; 0.05) and there was no significant difference between group A and group C (P gt; 0.05). CD34 expression: in group A, it was (+) at 7 days, (++) at 14 days, and (+++) at 21 days; in group B, it was (+) at 14 and 21 days; in group C, it was (++) at 7 days and (+++) at 14 and 21 days. Conclusion Topical appl ication of insul in can promote the synthesis of wound collagen, accelerate the woundangiogenesis, and speed up the wound heal ing in aging DM rats.
ObjectiveTo investigate the effect of phosphorylatable short peptide (pSP) conjugated chitosan (CS) (pSP-CS) mediated insul in-l ike growth factor 1 (IGF-1) gene and human interleukin 1 receptor antagonist (IL-1Ra) gene local transfection on the repair of articular cartilage defect. MethodsCo-expression plasmid pBudCE4.1-IL-1Ra+IGF-1, single gene expression plasmid pBudCE4.1-IL-1Ra and pBudCE4.1-IGF-1 were constructed and combined with pSP-CS to form pSP-CS/ pDNA complexes. Thirty 3-month-old healthy male New Zealand white rabbits, weighing 2.0-2.5 kg, double legs were randomly divided into 5 groups (n=12). Lateral femoral condyle articular surface was only exposed in sham-operated group (group A); full-thickness cartilage defects were created in the articular surface of the lateral femoral condyle of the knee in 4 intervention groups: pSP-CS/pBudCE4.1 (group B), pSP-CS/pBudCE4.1-IL-1Ra (group C), pSP-CS/pBudCE4.1-IGF-1(group D), and pSPCS/ pBudCE4.1-IL-1Ra+IGF-1 (group E). At 1 week after operation, intra-articular injection of pSP-CS/pDNA complexes was administrated 2 times a week for 7 weeks in each intervention group, the same volume normal sal ine in group A. The general condition of animal was observed after operation, and rabbits were sacrificed at 8 weeks. Knee joint synovial fluid was collected to measure the concentrations of the IL-1Ra and IGF-1 by ELISA; mRNA expressions of Aggrecan, matrix metalloproteinase 3 (MMP-3), and MMP inhibitor 1 (TIMP-1) were detected by real-time fluorescent quantitative PCR; the chondrogenic phenotype of nascent cells in the damage zone was identified by alcian blue-periodic acid/schiff (AB-PAS) histochemistry and Aggrecan immunohistochemistry staining. ResultsThirty experimental rabbits all survived to the end of experiment, without infection and death. Large amounts of exogenous proteins of IGF-1 and IL-1Ra were detected in the synovial fluid of 4 intervention groups. There were significant differences between groups D, E and group A in IGF-1 protein expression, and between goups C, E and group A in IL-1Ra protein expression (P < 0.05). Aggrecan and TIMP-1 mRNA expressions were significantly up-regulated in group E, simultaneously MMP-3 mRNA expression was significantly down-regulated when compared with groups C and D (P < 0.05). Varying degrees of cartilage repair appeared in groups C, D, and E, showing positive staining of AB-PAS and Aggrecan, and group E had better results than groups C and D (P < 0.05); inflammatory cell infiltration and fibrous tissue prol iferation were seen in the defect region of group B, without significant cartilage repairing. ConclusionpSP-CS is an ideal gene del ivery system for cartilage defect gene therapy; IL-1Ra and IGF-1 double gene transfection has better biologic effect on cartilage defect repair.