Objective To study the effect of two cytokines, basic fibroblast growth factor(bFGF) and insulin-like growth factor-I(IGF-I), on cell proliferation in chondrocytes of adult rabbits. Methods The primary chondrocytes of adult rabbits were harvested and cultured with bFGF and IGF-I at different concentrations,respectively, as well as with the mixture of the two cytokines; the quantity of cultured chondrocytes was detected by MTT assay at the 24th, 48th and 72th hours; and the final fold increase of different groups was measured by cell count for the 3rd passage; and the proliferation index of the groups was recorded by flowing cytometer on the 14th day. Results ① The cultured chondrocytes with either bFGF, IGF-I or their mixture were significantly more than that of control group at the 24th, 48th and 72th hours (P＜0.01). ② After the 3rd passage, the final folds of proliferation were significantly higher in the groups with cytokinesthan in the control group (P＜0.01); and the final fold with the mixture ofcytokines was significantly higher than that of both IGF-I and bFGF (P＜0.01). ③ Theproliferation index was significantly higher in the groups with cytokines than in the control group (P＜0.01); the proliferation index with the mixture of cytokines was significantly higher than that of both IGF-I and bFGF (P＜0.05); besides, proliferation index was higher when cytokine was applied twice than once (P＜0.05). Conclusion bFGF and IGF-I could promote chondrocytes proliferation of adult rabbits obviously and they are synergistic in cell proliferation.
ObjectiveTo investigate the relationship between insulin-like growth factor binding protein (IGFBP) gene with pancreatic cancer.
MethodsThe relevant literatures at home and abroad in recent years were reviewed. From the pancreatic cancer related genes, IGFBP related tumors and the correlation between IGFBP and pancreatic cancer research and other aspects of the previous research results were summaried.
ResultsMost of the studies suggested that IGFBP could inhibit the function of tumor cells through the IGF dependent pathway, but the deletion or mutation of IGFBP gene and its regulation mechanism are still unclear.
ConclusionIGFBP is closely related to the tumor, but its specific effects and mechanism of pancreatic cancer has not been settled. In order to affect the degree of cell differentiation, regulation of tumor growth and metastasis probability through the change of endogenous IGFBP gene level, the further studie is needed.
Objective
To determine the effect of methimazole (MMI) on retinal vascular development in neonatal rats, and to investigate the relationship between the concentration of insulin-like growth factor-I (IGF-I) in serum and the development of normal blood vessels and between the concentration of IGF-I and the formation of abnormal blood vessels.
Methods
There were 75 neonatal SpragueDawley rats in experimental group whose mothers were raised with water with 0.1% MMI at the first day of parturition. Another 50 neonatal rats were in the control group whose mothers were raised with normal water. The rats in the two groups were sub-divided into 4day and 10day subgroup, respectively. The retinal flatmount of the right eyes were stained with adenosine diphosphatase (ADPase); with the paraffin section of the left eyes, the number of nucleolus breaking through retinal inner limiting membrane was counted and the retinal blood vessels were evaluated. Serum IGF-I levels were detected by radioimmunoassay, and the weight of the neonatal rats in each group were observed and recorded.
Results
The incidence of retinal neovascularization in 10 day MMI group was 27%, and 0% in 4-day MMI group and control group. The serum IGF-I level in 4-day and 10-day MMI group (73.07 ng/ml, 175.13 ng/ml) was obviously lower than which in the 4-day and 10-day control group (168.73 ng/ml,306.38 ng/ml) （P=0.00）. Obvious slow growth of the neonatal rats was found in MMI group compared with which in the control group.
Conculsions
MMI may inhibit the normal growth of retinal blood vessels and lead neovascularization, which may relate to the initial decrease of the serum IGF-I level.
(Chin J Ocul Fundus Dis, 2007, 23: 198-201)
Objective To investigate the ability of repairing bone defect with the compound of recombinant human insulinlike growth factor 1 (rhIGF-1), coralline hydroxyapatite(CHA) and autogeneous red bone marrow(ARBM), and to study the feasibility of the compounds being used as bone substitute materials. Methods Bilateral radius bone defects(11 mm in length) were created in 54 Chinese rabbits,which were randomly divided into 3 groups, and two different materials were randomly transplanted into the bilateral defects:in group 1, with material A(rhIGF-1/CHA/ARBM) and material B(CHA/ARBM); in group 2, with material C(rhIGF-1/CHA) and material D(CHA); in group 3, with E(autograft) and F(no implant) as controls. At 2, 4, 8 and 12 weeks, the effects were assessed by X-ray andimage analysis, biomechanics(at 12 weeks), as well as histological observation. Results X-ray and image analysis showed that material A of group 1was significantly superior to any other materials(P＜0.01). Antibending biomechanic detection showed that material A and Ewas significantly superior to the other materials(Plt;0.01), but no significant difference was found between A and E in the 12th week(Pgt;0.05). And by histological observation, in analogical bone morphological progress, materials C and D obviously inferior to materials A, B and E, but there was no significant difference between materials C and D. F had no evidence of new bone rebridging. Conclusion The recombinant compound CHA/ARBM(rhIGF-1),which posseses the potential ability of osteogenesis,osteoconduction and osteoinduction for bone defect repairing,can serve as a new type of autogenous bone substitute material.
ObjectiveTo investigate the effects of micro-fracture and insul in-l ike growth factor 1 (IGF-1) in treatment of articular cartilage defect in rabbits.
MethodsTwenty-four New Zealand white rabbits (aged, 4-6 months; weighing, 2.5-3.5 kg) were randomly divided into 4 groups (n=6):micro-fractures and recombinant human IGF-1 (rhIGF-1) treatment group (group A), micro-fracture control group (group B), rhIGF-1 treatment control group (group C), and blank control group (group D). Full thickness articular cartilage defects of 8 mm×6 mm in size were created in the bilateral femoral condyles of all rabbits. The micro-fracture surgery was performed in groups A and B. The 0.1 mL rhIGF-1 (0.01 μg/μL) was injected into the knee cavity in groups A and C at 3 times a week for 4 weeks after operation, while 0.1 mL sal ine was injected in groups B and D at the same time points. At 4, 12, and 24 weeks, the gross, histological, and immunohistochemical observations were performed, and histological score also was processed according to Wakitani's score criteria. The collagen contents in the repair tissues and normal patellofemoral cartilage were detected by the improved hydroxyproline (HPR) method at 24 weeks. Electron microscope was used to observe repair tissues of groups A and B at 24 weeks. Results All animals were survival at the end of experiment. At 24 weeks after operation, defect was repaired with time, and the repair tissue was similar to normal cartilage in group A; the repair tissue was even without boundary with normal cartilage in group B; and the repair tissue was uneven with clear boundary with normal cartilage in groups C and D. Histological staining showed that the repair tissues had no difference with normal cartilage in group A; many oval chondrocytes-l ike cells and l ight-colored matrix were seen in the repair tissues of group B; only a few small spindle-shaped fibroblasts were seen in groups C and D. Moreover, histological scores of group A were significantly better than those of groups B, C, and D (P<0.05) at 4, 12, and 24 weeks. Electron microscope observation showed that a large number of lacuna were seen on the surface of repair tissue in group A, and chondrocytes contained glycogen granules were located in lacunae, and were surrounded with the collagen fibers, which was better than that in group B. Collagen content of the repair tissue in group A was significantly higher than that in groups B, C, and D (P<0.05), but it was significantly lower than that of normal cartilage (P<0.05). Conclusion Combination of micro-fracture and rhIGF-1 for the treatment of full thickness articular cartilage defects could promote the repair of defects by hyaline cartilage.
ObjectiveTo verify the expression change of insulin-like growth factor-Ⅰ (IGF-Ⅰ) protein and its mRNA before and after Roux-en-Y gastric bypass surgery (RYGB) in obese rats, and to investigate the relationship between the expression of IGF-Ⅰ and proliferation/apoptosis of adipose cells.
Methods① Seventy male SD rats were raised at the SPF level circumstance and were randomly divided into control group (NC group, 10 rats) and high fat diet group (60 rats). Rats of high fat diet group were given specific high fat formula diet, rats of NC group were given particular formula diet. After 6 weeks, the body weights of the rats in high fat diet group were measured, and the 20 rats of top weight were selected. The 20 obese rats were randomly divided into 2 groups:gastric bypass (GB) group (n=10) and sham-operation group (SO group, n=10). RYGB were administered to the rats of GB group, and for rats of SO group, sham operations were performed. Rats of NC group did not receive any surgery. Inguinal adipose tissues[represented the subcutaneous adipose tissue (SAT)] and epididymal adipose tissues[on behalf of visceral adipose tissue (VAT)] were taken during operation in rats of GB group and SO group respectively (0.5 g), and 12 weeks after operation in all rats of three groups. The expressions of IGF-Ⅰ protein and its mRNA in adipose tissue were detected by Western blot and real-time fluorescence quantitative PCR. ② Transfection experiment. SAT cells were divided into blank control group (BC group, without transfection), IGF-Ⅰ(+) group (gene overexpression group), IGF-Ⅰ(+) empty vector group, IGF-Ⅰ(-) group (gene silencing group), and IGF-Ⅰ(-) empty vector group. Cells were transfected with corresponding vectors with 3 duplicated holes of each group. Cell viability and apoptosis assays were carried out in 48 hours after transfection. Expressions of protein kinase B (AKT), phosphorylated protein kinase B (p-AKT), phosphoinositide 3-kinase (PI3K), and phosphorylated phosphoinositide 3-kinase (p-PI3K) were detected by Western blot meanwhile. ③ Wortmannin experiment. SAT cells were divided into Wortmannin (+) IGF-Ⅰ(+) group, Wortmannin (+) IGF-Ⅰ(-) group, Wortmannin (-) IGF-Ⅰ(+) group, and Wortmannin (-) IGF-Ⅰ(-) group, which were transfected with corresponding vectors for 24 hours, then adding Wortmannin (0.1 mmol/L). After 24 hours, the expression levels of AKT, p-AKT, p-PI3K, PI3K, and GAPDH were detected by Western blot.
Results① PCR results showed that, in SAT, compared with preoperative GB group, the expression levels of IGF-Ⅰ mRNA and its protein in postoperative GB group were both lower (P < 0.01). However, the expression levels of IGF-Ⅰ mRNA and its protein between preoperative SO group and postoperative SO group showed no significant difference (P > 0.05). In VAT, the expression levels of IGF-Ⅰ mRNA and its protein in 5 groups showed no significant difference (P > 0.05). ② The MTT results showed that, IGF-Ⅰ(+) group harbored stronger proliferation abilities compared with its negative control group (P=0.04), whereas IGF-Ⅰ(-) group had lower abilities compared with its negative control group (P=0.04). The results of flow cytometry assay showed that, the apoptosis rate of IGF-Ⅰ(+) group was lower (P=0.04) than that of the corresponding negative control group, and it was higher in IGF-Ⅰ(-) group than that of the corresponding negative control group (P=0.04). ③ Compared with IGF-Ⅰ(+) empty vector group, p-PI3K/PI3K ratio (P=0.03) and p-AKT/AKT (P=0.04) ratio of IGF-Ⅰ(+) group were increased; compared with IGF-Ⅰ(-) empty vector group, p-PI3K/PI3K ratio (P=0.04) and p-AKT/AKT ratio (P=0.04) of IGF-Ⅰ(-) group were decreased. The p-AKT/AKT ratio of Wortmannin (-) IGF-Ⅰ(+) group was higher (P < 0.05) than that of Wortmannin (+) IGF-Ⅰ(+) group; the p-AKT/AKT ratio of Wortmannin (-) IGF-Ⅰ(-) group was lower than that of Wortmannin (-) IGF-Ⅰ(+) group (P < 0.05).
ConclusionsIGF-Ⅰ is involved in the accumulation of subcutaneous fat in rats. RYGB can significantly reduce the expression levels of IGF-Ⅰ mRNA and its protein in subcutaneous fat of rats, so as to achieve the effect of weight loss.
Objective To investigate the effects of insulin-like growth factor 1（IGF-1） and ethanol (EtOH) on the changes in the osteoblast proliferation and the osteoblast function under the normal serum concentration and serum starvationMethodsThe osteoblasts harvested from the SD rat calvaria were incubated in the following six conditions according to the supplements in DMEM: the F15group：15% newborn calf serum (NCS)； the F15/EtOH group：100 mmol/L of EtOH added to 15% NCS； the F2 group：2% NCS； the F2/EtOH group：100 mmol/L of EtOH added to 2% NCS；the F2/IGF-1 group：25ng/ml of IGF-1 added to 2% NCS；the F2/IGF-1/EtOH group：100 mmol/L EtOH added to 25 ng/ml IGF-1 and 2% NCS. The osteoblasts were analyzed by the MTTassay, alkaline phosphatase（ALP） activity, and RTPCR at 24, 48, 72 and 96h ours after the culture. Results The absorbance (A), the ALP activity, and the expression of BGP mRNA (the proliferation and function indicators of the osteoblasts) were significantly decreased in the F15/EtOH group at all the time points when compared with those in the F15the group (P＜ 0.05); the above 3 indicators were significantly decreased in the F2 groupwhen compared with those in the F15 group (P＜0.05); they were significantly decreased in the F2/EtOH group when compared with those in the F2 group (P＜0.05); however, the indicators in the F2/IGF-1 group were significantly increased when compared with those in the F2 group (P＜0.05); the A value in the F2/IGF-1/EtOH group was not significantly decreased when compared with that in the F2/IGF-1 group, with an exception of the A value at 24 hours (P＞0.05); however, ALP and BGP mRNA were significantly decreased (P＜0.05). All the indicators were significantly increased when compared with those in the F2/EtOH group (P＜0.05) Conclusion Ethanol can inhibit the osteoblast proliferation and the osteoblast function, and can increase the inhibition when the osteoblasts were cultured under the serum starvation. This may be one of the mechanisms for alcoholic bone disease. IGF-1 can prevent the inhibition of the osteoblasts under the serum starvation and counteract the ethanolinduced proliferation inhibition; therefore, IGF-1 is an alternaive therapeutic intervention for alcoholic bone disease.
ObjectiveTo evaluate the possible role of the expression of insulin-like growth factor-1 receptor (IGF-1R) in determining rectal cancer radiosensitivity. MethodsThe paired preradiation biopsy specimens and postoperative specimens were obtained from 87 patients with rectal cancer in the department of digestive tumor surgery, Jiangsu Province Hospital of Traditional Chinese Medicine, Affiliated Hospital of Nanjing University of Traditional Chinese Medicine from January 2009 to December 2010. The IGF-1R expression was examined by immunohistochemistry (IHC) and reverse transcription-polymerase chain reaction (RT-PCR). The tumor radiosensitivity was defined according to Rectal Cancer Regression Grade, then the relation between the IGF-1R expression and tumor radiosensitivity was evaluated. ResultsCompared with the preradiation biopsy specimens, IGF-1R expression significantly increased in the paired postoperative specimens of the residual cancer cells (Plt;0.001). The IHC result demonstrated IGF-1R overexpression was significantly associated with a poor response to radiotherapy (rs=0.401, Plt;0.001); RT-PCR detection of IGF-1R expression on preradiation biopsy specimens also showed that IGF-1R mRNA negative patients had a higher radiation sensitivity (rs=0.497, Plt;0.001). ConclusionDetection of IGF-1R expression may predict radiosensitivity of preoperative irradiation for rectal cancer.
OBJECTIVE: To investigate the effect of electroacupuncture on mRNA expression of NGF and IGF-1 in injured nerve. METHODS: Sciatic nerve injury model was established by transection of right side sciatic nerve in 90 male SD rats, which were randomly divided into two groups. The experimental group was treated with electroacupuncture, no treatment in the control group. The distal part of the injured nerve was harvested after 1, 2, 4, 6 and 10 weeks of operation and stored in the liquid nitrogen. The total RNA was extracted by the TRIzol reagent. Reverse transcriptase-polymerase chain reaction(RT-PCR) was used to detected the mRNA expression of NGF and IGF-1. RESULTS: The mRNA expression of NGF in the experimental group was increased quickly from the second week, and reached to highest level in the fourth week. It was much higher than that of the control group (P lt; 0.05). Then it began to decline in following time and approximately reached to the level of the first week after 10 weeks of operation. The mRNA expression of IGF-1 in the experimental group was remarkably increased in the second and fourth week, and which was much higher than that of the control group respectively(P lt; 0.05). Although the mRNA expression of IGF-1 after 10 weeks of operation in the experimental group was higher than that of the control group, but there was no significant difference between the two groups(P gt; 0.05). There was linear correlation in the fourth week between mRNA expression of NGF and IGF-1 in the experimental group. CONCLUSION: The mRNA expression of NGF and IGF-1 can be elevated in injured nerve at early stage interfered with electroacupuncture.
Objective
To probe the relationship between the levels of two hormone,growth hormone (GH) and insulin-I like growth factor-I(IGF-I),and diabetic retinopathy (DR) in the patients with noninsulindependent diabetic mellitus (NIDDM)． Methods
The direct radioimmunoassay was used to determine GH and IGF-I in the serum of 38 normal cotrols,61 NIDDM patients without DR,77 patients with the simple DR and 48 patients with the proliferative DR．Difference among these groups were analysed and compared by the methods of t test,F test and correlation analysis． Results
The results showed that the levels of GH and IGF-I in the patients with diabetes [GH(1.659plusmn;1.509)ng/ml，IGF-I(118.7plusmn;52.0) ng/ml] were significantly higher than those in the normal controls [GH(0.619plusmn;0.351)ng/ml，IGF-I (63.6plusmn;30.6) ng/ml)] (P＜0.01),and those in the DR group were higher than those in the NIDDM without retinopathy group (P＜0.01),and levels of GH and IGF-I in the proliferative DR group [GH(2.953plusmn;1.648) ng/ml，IGF-I (159.2plusmn;47.5) ng/ml] ) were significantly higher than those in the simple DR group [GH(1.742plusmn;1.523) ng/ml，IGF-I (123.6plusmn;40.6) ng/ml] (P＜0.01)．SeveritY of DR was positively correlated with the levels of GH and IGF-I(P＜0.01)． Conclusion
The results indicate that GH and IGF-I levels in the serum of patients with diabetes might be correlated with mechanisms and development of DR． (Chin J Ocul Fundus Dis,2000,16:30-31)
