To explore the relationship between Insulin-like growth factor (IGF)-I , -II and lung development in neonatal rats. 80 timed pregnant Sprague-Dawley (SD) rats were randomly divided into 4 groups (n=20): group A (Control group), group B (Dexamethasone (DEX) 1 group), group C (DEX 2 group), group D (retinoic acid (RA) group). 20 pregnant rats in group A, B and D were injected subcutaneously or intraperitoneally with vehicle (NS), DEX, or RA respectively during gestational day 16 to 18. All newborn rats in group C were subcutaneously injected with DEX at day 1 to 3 after birth. The lung tissue was obtained at the following times: fetuses at gestational ages of 18, 20 and 21 days, and 1, 3, 5, 7, 10, 14 and 21 days after birth. Lung tissues were used for histopathological study, the polypeptides analysis of IGF- I, -II (immunohistochemistry and Western blot) and mRNA analysis ( RT- PCR). The results showed that the strongest expression of IGF- I in group A and D occurred at ages of 5-7 days (alveolar stage). The stronger their expressions, the better the alveolar develop. The peak stage of expression in group B occurred earlier, on the day 3 after birth. Compared with group A, the expression of IGF-I during gestation age of 18 days to age of 3 days in group B were significantly higher (P<0.01), but significantly lower at other time points (P<0.01). The expression of IGF-I was lower in group C all the time and always higher in group D than those in group A (P<0.01). The peak expression of IGF-II took place at the gestation age of 18 days, then gradually dropped to trace. During 18 days of gestation to age of 3 days, the expression of IGF-II in group B was significantly higher than that in group A (P<0.01). No difference was found among all other groups. The change in the expression of IGF-I, -II mRNA in all 4 groups was similar to that of their polypeptides. The results suggested that there is a close linking between IGF-I , -II and lung development in newborns. The IGF-II works at early stage and the that of IGF- I works at the stage of new septa formation and alveoli maturation. The stronger their expressions, the more mature the lung development.
Animals ; Animals, Newborn ; Dexamethasone ; pharmacology ; Female ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Insulin-Like Growth Factor II ; biosynthesis ; genetics ; Lung ; embryology ; growth & development ; metabolism ; Male ; Pregnancy ; RNA, Messenger ; biosynthesis ; genetics ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Tretinoin ; pharmacology

In the study of the relationship between cells overloading and the formation, regeneration and growth of bone, the text discussed osteoblasts express IGF-1 variation under overloading environment. The research of overloading on cellular level may elucidate the mechanical effect on the formation, regeneration and growth of bone and the mechanism of cell response in bone.
Animals ; Humans ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Osteoblasts ; cytology ; metabolism ; Osteogenesis ; RNA, Messenger ; biosynthesis ; genetics ; Stress, Mechanical ; Weight-Bearing ; physiology

OBJECTIVETo examine the effects of high and low concentrations of transforming growth factor (TGF) β(1) and insulin-like growth factor-I (IGF-I) on the extracelluar matrix synthesis of the self-assembled constructs of temporomandibular joint (TMJ) disc.

METHODSThe experimental groups of self-assembled constructs were exposed to IGF-I (10, 100 µg/L) and TGF-β(1) (5, 50 µg/L), the control groups were not added with any growth factors. All groups were examined at 3 and 6 weeks for gross morphological, histological, and biochemical changes. Safranin-O/fast green staining was used to examine glycosaminoglycan (GAG) distribution, picrosirius red and immunohistochemical staining to observe type I collagen distribution. Type I collagen contents were tested by ELISA assay kit, GAG contents were measured by Blyscan GAG assay kit, and the cell numbers were quantified with a Picogreen reagent kit.

RESULTSThe growth factor groups all upregulated the matrix synthesis of the self-assembled constructs compared with control groups. TGF-β(1) (5 µg/L) and IGF-I (10 µg/L) were the two most potent concentration in increasing type I collagen and GAG synthesis and cells proliferation. IGF-I group (10 µg/L) produced nearly 2 times (109.16 ± 5.12 µg) as much type I collagen as the control group (69.13 ± 5.94 µg) at 3 weeks. The matrix contents and the number of the proliferated cells in control group and all GF groups at 6 weeks were more than those at 3 weeks.

CONCLUSIONSIGF-I (10 µg/L) is the most beneficial growth factor and can be applied in tissue-engineering stratigies of the temporomandibular joint disc. At the same time, the exposure time of growth factors is another key factor that affects matrix synthesis of TMJ disc constructs.

Animals ; Cell Proliferation ; drug effects ; Cells, Cultured ; Collagen Type I ; biosynthesis ; Extracellular Matrix ; metabolism ; Glycosaminoglycans ; biosynthesis ; Goats ; Insulin-Like Growth Factor I ; pharmacology ; Temporomandibular Joint Disc ; cytology ; metabolism ; Tissue Engineering ; methods ; Transforming Growth Factor beta1 ; pharmacology

Mechano-growth factor (MGF) is one of IGF-1 isoforms. MGF is mechanosensitive and has important functions in muscle hypertrophy, regeneration and nerve injury recovery. In this study, MGF cDNA (330 bp) was cloned from stretched osteoblasts by RT-PCR. In order to avoid prolin residue inhibiting enterokinase cleavage, 9bp of MGF cDNA 5' end sequence was truncated by primer, then the obtained truncated MGF (des(1-3)MGF) cDNA (321 bp) was subcloned in pET32a(+) vector to construct a prokaryotic recombination expression plasmid. Trx/des(1-3)MGF fusion protein, existing in forms of solution, was expressed in transformed Escherichia coli strain BL21(DE3) by IPTG induction at 30 degres C. The supernatant of cell lysates was subjected to ion exchange chromatography and Ni2+ metal affinity chromatography, and the fusion protein was obtained with the purity over 95%. After the fusion protein was cleaved by enterokinase, Trx and des(1-3)MGF was isolated by reverse-phase HPLC. Through these procedures, des(1-3) MGF was obtained with the purity of 98%. The protein molecular mass was conformity to the theoretical value by SDS-PAGE and mass spectrometry analysis. The purified des(1-3)MGF was incubated with MC3T3-E1 for cell proliferation and migration assays. The results show that des(1-3)MGF exhibited more facilitative effects on proliferation and migration of MC3T3-E1 than that of des(1-3)IGF-1.
Cloning, Molecular ; DNA, Complementary ; genetics ; Escherichia coli ; genetics ; metabolism ; Humans ; Insulin-Like Growth Factor I ; Osteoblasts ; metabolism ; Protein Isoforms ; biosynthesis ; genetics ; Recombinant Fusion Proteins ; biosynthesis ; genetics ; pharmacology ; STAT5 Transcription Factor ; biosynthesis ; genetics ; Tumor Suppressor Proteins ; biosynthesis ; genetics

OBJECTIVETo investigate the effectiveness of human insulin-like growth factor I (hIGF-I) gene transferred into the cultured goat bone marrow mesenchymal stem cells with liposome, and find a new method of cell-mediated gene therapy.

METHODSBone marrow was extracted from adult goats and cultured in vitro by monolayer. Then the recombinant eukaryotic expression plasmid pIRES2-EGFP-hIGF was transfected into cells by FuGene 6. After transfection, the marker gene coding enhanced green fluorescent protein (EGFP) was observed at different time points. The hIGF concentration in the supernatant fluids was measured by enzyme-linked immunosorbent assay (ELISA) and immunohistochemistry stain of hIGF was performed to detect the target protein. Besides, reverse transcription polymerase chain reaction and flow cytometry were also adopted in order to find out the changes of cells after transfection.

RESULTSBone marrow stem cells were all in the long shuttle-like shape and adhered to the disk. The expression of EGFP was first found at 4 h after transfection. The amount and intensity of EGFP increased gradually during the period of detection and got to the peak degree at 72 h, after that decreased slowly. EGFP was also seen in the second generation cells, but the intensity was relatively faint. The IGF-I concentration secreted into the supernatant was in accordance with the EGFP observed with the peak concentration at 34.75 ng/ml. The outcome of RT-PCR and immunohistochemistry was positive. The morphology of many stem cells was changed into triangular or irregular forms under the circumstance of the secreted hIGF-I. Percentage of stem cells in the S stage increased after transfection.

CONCLUSIONThe hIGF-I gene can be transfected efficiently and safely into BMSCs by FuGene 6, and the hIGF-I protein can be secreted into the supernatant in a relatively high level during a long period, therefore accelerate the proliferation and differentiation of the transfected cells.

Animals ; Bone Marrow Cells ; cytology ; Cell Differentiation ; Genetic Vectors ; Goats ; Humans ; In Vitro Techniques ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Male ; Mesenchymal Stromal Cells ; cytology ; Plasmids ; genetics ; Transfection

To study the morphological characteristics of hepatic stem cells and the expression of HGF, IGF-I, TGFbeta1 and their receptors in human embryonic livers at 3-5 weeks of gestation. The SABC immunohistochemical method with HE counterstaining was employed. We found that the hepatic bud formed at the end of the 3rd week. At the 4th week, the cells of hepatic bud migrated into the septum transversum mesenchyme and formed the hepatic cords. The hepatic cells at 3-4 weeks displayed the typical characteristics of immature cells: small size, a round or ovoid nucleus with dark color, scant cytoplasm with slight blue and a high ratio of nuclei/cytoplasm. They were positive for alpha-Fetoprotein (AFP), c-Met and negative for cytokertin 19 (CK19), and proliferating cell nuclear antigen (PCNA). At the 5th week, compared to those at the 4th week, the number of cells within the hepatic cords increased. But the cells at the 5th week were homogeneous and displayed the typical characteristic of immature cells. Those cells began to express PCNA at the 5th week. The hepatic cells at the 5th week were positive for insulin-like growth factor I (IGF-I), transforming growth factor beta1 (TGFbeta1) and their receptors, and were negative for hepatocyte growth factor (HGF), while HGF were positive in the cardiac cells and septum transversum mesenchyme. The results indicated that the cells of hepatic bud and cords were the hepatic stem cells. The difference of morphology and proteins expression at 3-5 weeks of gestation inferred that those stem cells belong to different developmental stage. AFP and c-Met were the markers of hepatic stem cells at the early stage of human embryo. HGF, IGF-I, TGFbeta1 and their receptors may involve in regulating the development of early embryonic human liver.
Embryo, Mammalian ; Gestational Age ; Hepatocyte Growth Factor ; biosynthesis ; genetics ; Humans ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Liver ; cytology ; metabolism ; Proto-Oncogene Proteins c-met ; biosynthesis ; genetics ; Receptor, IGF Type 1 ; biosynthesis ; genetics ; Stem Cells ; cytology ; Transforming Growth Factor beta ; biosynthesis ; genetics ; Transforming Growth Factor beta1

Whether cultured bovine trabecular meshwork cells and trabecular tissue ex vivo express insulin-like growth factor-I (IGF-I) messenger RNA (mRNA) and protein was investigated. Total RNA of cultured bovine trabecular meshwork cells as well as trabecular meshwork tissue freshly excised from bovine eyes was extracted, and reverse transcriptase-polymerase chain reaction (RT-PCR) was used to detect IGF-I mRNA. RT-PCR product was verified by sequencing. Immunohistochemical stain was used to detect IGF-I protein. The results showed that a single PCR amplified product was obtained, and the sequence was homologous to the known sequence.. IGF-I immunostain was positive in the cytoplasm of trabecular meshwork cells. It was concluded that trabecular meshwork cells produce IGF-I and contribute to the presence of IGF-I in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by IGF-I not only through paracrine, but also autocrine action. Whether abnormal down-regulations in IGF-I production may contribute to the pathogenesis of primary open-angle glaucoma and the possibility of promoting the autocrine action of IGF-I by trabecular meshwork cells to treat the disease is worth further investigation.
Cells, Cultured ; Cloning, Molecular ; Glaucoma, Open-Angle/etiology ; Glaucoma, Open-Angle/metabolism ; Insulin-Like Growth Factor I/biosynthesis ; Insulin-Like Growth Factor I/*genetics ; RNA, Messenger/biosynthesis ; RNA, Messenger/genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Sequence Analysis, DNA ; Trabecular Meshwork/cytology ; Trabecular Meshwork/*metabolism

OBJECTIVETo optimize the culture media by adding the growth factors required to maintain tenocytes survival and promote their differentiation without fetal bovine serum (FBS) supplementation, in order for the approach to be used for any future tendon tissue engineering.

METHODSThe human tenocytes were cultured in α-MEM media by adding FBS at various concentrations and supplementing both insulin-like growth factor 1 (IGF-1) and transforming growth factor β-3 (TGFβ-3). A number of growth factors were selected that could support tenocytes expansion at reduced differentiated state with the minimum FBS. By employing fractional factorial design, different treatment groups went through AlamarBlue(TM) tests to evaluate the cell number growth whilst collagen quantification by real time RT-PCR technique and tenocyte differentiation were also studied.

RESULTSThe tenocytes cultured for 14 days with 0% FBS, 50 ng/ml IGF-1 and 10 ng/ml TGFβ-3 maintained survival over 14 days, the Cell count were 6228.68 ± 43.87. They were higher than the other experimental groups, but less than 10% FBS control group (13 576.74 ± 286.75, t = 41.29, P < 0.05). The tenocytes cultured in the treated group also showed enhanced collagen synthesis ((0.322 ± 0.003) ng, t = 4.13 - 5.93, P < 0.05).

CONCLUSIONThese findings have shown for the first time that human tenocytes could be maintained survival for a long period of time in the culture media without FBS, having this approach a suitable one for tendon tissue engineering.

Cell Differentiation ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Collagen ; biosynthesis ; Culture Media ; pharmacology ; Humans ; Insulin-Like Growth Factor I ; pharmacology ; Tendons ; cytology ; drug effects ; metabolism ; Transforming Growth Factor beta3 ; pharmacology

BACKGROUND/AIMS: The insulin-like growth factor (IGF) system has been implicated in tumor growth, invasion, and metastasis. However, reports on the IGF-1 receptor (IGF-1R) based on radioimmunoassays are conflicting, and its prognostic implications in non-small-cell lung cancer (NSCLC) are still controversial. METHODS: Seventy-one paraffin-embedded tissue sections from stage I NSCLC patients were stained using a mouse monoclonal antibody against human IGF-1R. RESULTS: The intensity and frequency of IGF-1R expression on the membrane and cytoplasm of cancer cells was evaluated and scored using a semiquantitative system. IGF-1R expression was detected in nine of 71 (12.7%) cases. No significant relationship was found between clinical/histopathological parameters and IGF-1R expression. None of the patients whose tumor expressed IGF-1R had experienced distant metastasis or cancer-related death, although the difference did not reach statistical significance. CONCLUSIONS: We conclude that IGF-1R expression may not be a major prognostic factor for stage I NSCLC.
Adult ; Aged ; Aged, 80 and over ; Animals ; Carcinoma, Non-Small-Cell Lung/*immunology/mortality/pathology ; Female ; Humans ; Immunohistochemistry ; Insulin-Like Growth Factor I/*biosynthesis ; Male ; Mice ; Middle Aged ; Neoplasm Metastasis ; Neoplasm Staging ; Prognosis ; Receptor, IGF Type 1/*biosynthesis

With the use of a cyclic strain unit, the proliferation and gene expression of IGF-1 in the rat osteoblasts that underwent mechanical strain were studied. The cells were subjected to 15% elongation at frequency 20 cycles/min for different loading time. Under the action of different loading time, the relative proliferation index of the rat osteoblasts was the biggest of all when loading time was 12h; during the course, the expression of IGF-1 mRNA increased significantly, and then gradually tended toward 1 with the increase of the loading time. These results demonstrate that osteoblasts respond to the mechanical forces which may regulate the activities of osteoblasts indirectly by promoting the autocrine effect of IGF-1. Loaded osteoblasts can adjust and adapt themselves to new mechanical stimulation, and hence maintain a new state of equilibrium.
Animals ; Animals, Newborn ; Cell Proliferation ; Cells, Cultured ; Gene Expression ; Insulin-Like Growth Factor I ; biosynthesis ; genetics ; Osteoblasts ; cytology ; metabolism ; RNA, Messenger ; biosynthesis ; genetics ; Rats ; Rats, Wistar ; Skull ; cytology ; Stress, Mechanical