AIM:To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats. METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected t...AIM:To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats. METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected to the diabetic rats through lavage and coloclysis, respectively. Fasting blood glucose and plasma insulin levels were measured for 7 d. Reverse transcription polymerase chain reaction (RT-PCR) analysis and Western blot analysis were performed to confirm the expression of human insulin gene. RESULTS: Compared with the control group, the fasting blood glucose levels in the lavage and coloclysis groups were decreased significantly in 4 d (5.63 ± 0.48 mmol/L and 5.07 ± 0.37 mmol/L vs 22.12 ± 1.31 mmol/L, respectively, P < 0.01), while the plasma insulin levels were much higher (32.26 ± 1.81 μIU/mL and 32.79 ± 1.84 μIU/mL vs 14.23 ± 1.38 μIU/mL, respectively, P < 0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and coloclysis groups. CONCLUSION: Human insulin gene wrapped with chitosan nanoparticles can be successfully transfected to rats through gastrointestinal tract, indicating that chitosan is a promising non-viral vector.展开更多
Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein. BrdU-positive cells at day 7 post-transplantation, ...Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein. BrdU-positive cells at day 7 post-transplantation, as well as nestin- and neuron specific enolase-positive cells at day 14 were increased compared with those of the single neural stem cell transplantation group. In addition, the proportion of neuronal differentiation was enhanced. The genetically modified cell-transplanted rats exhibited enhanced performance in correctly crossing a Y-maze and climbing an angled slope compared with those of the single neural stem cell transplantation group. These results showed that human insulin-like growth factor 1-transfected neural stem cell transplantation promotes the recovery of the leaming, memory and motor functions in hypoxic-ischemic rats.展开更多
The plant expression vector of choleratoxin B subunit(CTB)-human insulin(BA) fusion protein pBI121/(CTB-BA) was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express C...The plant expression vector of choleratoxin B subunit(CTB)-human insulin(BA) fusion protein pBI121/(CTB-BA) was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and its hypoglycemic effect was evaluated in mice. The plant expression vector pBl 121/(CTB-BA) was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was transformed with previously constructed recombinant plasmid pBI121/(CTB-BA) via the freeze thawing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by co-culturing the cells with the transformed LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA sequence assey and RT-PCR. The expressed product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice. The sequences of synthetic CTB and human insulin genes(BA) were completely identical to those designed. Restriction map proved that the length of gene fragment in- serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was consistent with that expected. The expressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result. The animal test showed that only the G Pentapyhllum Makino callus cell line itself showed activity in decreasing the blood sugar of mice, however, the activity of the transformed G Pentapyhllum Makino callus cells was much higher, The plant expression vector pBI121/(CTB-BA) was constructed and expressed in the G Pentapyhllum Makino callus cells successfully for the first time. The trans- formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This study developed a new way for the development of oral administration insulin.展开更多
We report a 64-year-old female patient with an insulin allergy. She was treated with a combination of oral antihistamines, topical hydrocortisone cream, and moisturizing agents, which resulted in the improvement of ec...We report a 64-year-old female patient with an insulin allergy. She was treated with a combination of oral antihistamines, topical hydrocortisone cream, and moisturizing agents, which resulted in the improvement of eczema and intense pruritus. To evaluate insulin allergy, intradermal skin tests were performed with several insulin agents for clinical use and 0.9% NaCl. Skin testing with semisynthetic human insulin resulted in local, immediate skin reactions such as itchy erythema and wheals. Furthermore, we analyzed our case and 25 Japanese cases of insulin allergy previously reported in the literature as far as we know. Interestingly, the number of male patients was approximately two times higher than that of female, and the insulin-specific IgE antibody test was positive in 21 patients. We should keep the possibility of human insulin allergy in mind and prepare for it when initiating human insulin therapy.展开更多
BACKGROUND: Mesenchymal stem cells derived from human umbilical cord blood (UCB-MSCs) have good research and application prospects in the treatment of diabetes. We once induced UCB-MSCs to differentiate into insulin-p...BACKGROUND: Mesenchymal stem cells derived from human umbilical cord blood (UCB-MSCs) have good research and application prospects in the treatment of diabetes. We once induced UCB-MSCs to differentiate into insulin-producing cells (IPCs) in vitro, but we did not know the functions of these cells in vivo. The aim of this study was to assess the functional effects of IPCs on insulin secretion and their role in the treatment of diabetes in vivo. METHODS: UCB-MSCs were induced to IPCs by an inducing protocol with extracellular matrix gel. BALB/C nude mice were made hyperglycemic by intraperitoneal injection of streptozotocin. The diabetic mice were transplanted with 1x10(7) IPCs under the renal capsule or with phosphate-buffered saline as a control. After transplantation, the grafts were analyzed by immunocytochemistry for the expression of human insulin; the serum human insulin levels were measured; and blood glucose and body weight status were monitored. RESULTS: Immunofluorescence showed that numerous IPCs under the kidney capsule were insulin-positive. On day 14 after transplantation, the serum human insulin level of the treatment group (n=9) averaged 0.44 +/- 0.12 mU/L, which was higher than that of the control group (n=9) that did not express insulin (t=10.842, P<0.05). The diabetic mice remained hyperglycemic and kept losing body weight after IPC transplantation, and there was no significant difference in the control group. CONCLUSION: IPCs differentiated from UCB-MSCs generate human insulin in diabetic mice, but more research is needed to make further use of them to regulate hyperglycemia and body weight in vivo. (Hepatobiliary Pancreat Dis Int 2009; 8: 255-260)展开更多
The resorption of the transplanted fat over time limited the use of autologous fat for the reconstruction of soft tissue defect. Tissue engineering (TE) adipose with silk fibroin scaffold could be a promising substitu...The resorption of the transplanted fat over time limited the use of autologous fat for the reconstruction of soft tissue defect. Tissue engineering (TE) adipose with silk fibroin scaffold could be a promising substitute for soft tissue filling. In this study, we try to develop a tissue engineering adipose in vitro by seeding silk fibroin scaffold with human umbilical cord mesenchymal stem cells (hUCMSCs) after transfected with recombinant human insulin gene lentivirus. Our aim was to observe the effects of the insulin gene transfection on the adipogenesis of hUCMSCs when cultured with silk fibroin scaffolds. The hUCMSCs infected with recombinant lentiviral pLenti6.3-insulin-IRES-EGFP were seeded on silk fibroin scaffolds and cultured in adipogenic differentiation medium for 5 - 7 days. The expression of adipogenic gene PPARγ-2 was tested by RT-PCR after 7 days culture of adipogenic induction. The accumulation of cytoplasmic droplets of neutral lipids was assessed by Oil Red O staining. The RNA and protein expression of transfected insulin gene in hUCMSCs were detected by QPCR and western blot. The effect of recombinant lentivirus transfection on the growth and proliferation of hUCMSCs was observed by MTT test. We observed that the 2-ΔΔCt value of insulin gene expression of hUCMSCs in the transfected group was 300.25 times higher than that in the untransfected group. The western blot showed that a positive band was discerned at the site of a relative molecular mass of 8 × 103 Dalton in transfected group. After adipogenic culture for 7 days, under the fluorescent inverted phase-contrast microscope, after Oil Red O staining, a lot of adipocytes appeared in silk fibroin scaffold;round adipose droplets showed intracellularly;the size of the adipocytes was not homogenous, and the density of adipocytes in transfected group was significantly higher than that in untransfected group (P = 0.007, P < 0.01). RT-PCR results showed that the expression of adipogenic gene PPARγ-2 in transfected group was much stronger than that in untransfected group. MTT test showed that there was no significant difference in optical density (A) at each time point between transfected group and nontransfected group (P = 0.056, P > 0.05). And there was also no significant difference in optical density (A) between cell group and cell-scalffold group (P = 0.066, P > 0.05). We concluded that insulin gene could obviously promote the adipogenic differentiation of hUCMSCs, and a tissue engineering adipose could be constructed by the silk fibroin scaffolds seeded with human insulin gene-modified hUCMSCs effectively in vitro.展开更多
In the present study, the cleavage activities of both recombinant and bovine enzymes (trypsin and carboxy peptidase B) were determined using proinsulin fusion protein. The proteolysis products were analyzed with HPL...In the present study, the cleavage activities of both recombinant and bovine enzymes (trypsin and carboxy peptidase B) were determined using proinsulin fusion protein. The proteolysis products were analyzed with HPLC. We found that recombinant enzymes had stronger activities and produced fewer by-products. In addition, recombinant enzymes were more efficient in the production of human insulin than bovine enzymes.展开更多
A synthetic single-chain porcine insulin precursor (PIP) gene and an α-mating factor leader sequence (αMFL) gene obtained by the PCR method are inserted between the promoter and 3’-terminating sequence of the alcoh...A synthetic single-chain porcine insulin precursor (PIP) gene and an α-mating factor leader sequence (αMFL) gene obtained by the PCR method are inserted between the promoter and 3’-terminating sequence of the alcohol dehydrogenase gene ADH1 in plasmid pVT102-U to form plasmid pVT102-U/α MFL-PIP. The single-chain insulin precursor is expressed and secreted to the culture medium by Saccharomyces cererisiae transformed by pVT102-U/αMFL-PIP. The precursor is purified and converted into human insulin by tryptic transpeptidation. The purified human insulin is fully active and can be crystallized. The overall yield of human insulin is 25 mg per liter of culture medium.展开更多
Background Glycemic control prevents onset and progression of diabetes-related long-term complications. The objective of this study was to demonstrate that twice daily insulin lispro low mix 25 is noninferior to twice...Background Glycemic control prevents onset and progression of diabetes-related long-term complications. The objective of this study was to demonstrate that twice daily insulin lispro low mix 25 is noninferior to twice daily human insulin mix 30/70 in achieving glycemic control as measured by hemoglobin Alc (HbAlc), from baseline to endpoint, in patients with type 1 or 2 diabetes. Methods In this phase IV, crossover, open-label, multicenter study, 117 Chinese patients with diabetes were randomly assigned to one of two treatment sequence groups. One group received 12-week treatment with twice daily human insulin mix 30/70 followed by 12-week treatment with twice daily insulin lispro low mix 25, while the other group received the reverse treatment sequence. HbAlc, baseline-to-endpoint change in HbAlc, proportion of patients achieving target HbAlc ≤ 7% and 〈 6.5%, fasting blood glucose, and daily insulin doses were measured for each period. Safety and tolerability were also assessed. Results A statistically significant reduction (P≤0.0001) of HbAlc was achieved after each treatment (human insulin mix 30/70: mean HbA1c=7.91% (95% CI: 7,67%, 8.15%); insulin lispro low mix 25: mean HbA1c=7.96% (95% CI: 7.72%, 8.20%)). The 95% Cl (-0.20, 0.10) of the difference between the two treatments satisfied the prespecified noninferiority margin of 0.3% (lower limit of 95% CI 〉 -0.3%). No statistically significant differences between treatments were observed for any of the secondary efficacy measures. The incidence of treatment-emergent adverse events and hypoglycemia between the two treatments and treatment sequence groups was similar. Three serious adverse events were reported (human insulin mix 30/70 group: 2 patients (1.7%, hypoglycemic coma and cardiac failure); insulin lispro low mix 25 group: 1 patient (0.9%, stroke)). All serious adverse events were resolved and no patients died during the study. Conclusion The results support noninferiority of twice daily insulin lispro low mix 25 versus twice daily human insulin mix 30/70 in HbAlc control in Chinese patients with type 1 or 2 diabetes.展开更多
It has long been found that insulin in acid solution is unstable. The main reason is that the A-chain C-terminal residue, asparagine, is very susceptible to acid hydrolysis, thereby a covalent-dimer formation takes pl...It has long been found that insulin in acid solution is unstable. The main reason is that the A-chain C-terminal residue, asparagine, is very susceptible to acid hydrolysis, thereby a covalent-dimer formation takes place readily due to the deamidation of this residue. As a number of pharmaceutical preparations of insulin are acidic solutions, this kind of instability has brought about a serious problem on purity and storage of this preparation in展开更多
Ⅰ. INTRODUCTIONThe chemical stability of human insulin preparations is directly related to the residue of A21-Asn at C-terminal of A chain and can be distinctly increased by substituting the A21 residue in the way of...Ⅰ. INTRODUCTIONThe chemical stability of human insulin preparations is directly related to the residue of A21-Asn at C-terminal of A chain and can be distinctly increased by substituting the A21 residue in the way of protein engineering. Studying the fine three-dimensional structures展开更多
Ⅰ. INTRODUCTIONImmune reaction remains a challenging problem in the clinical application of various insulin preparations. It is known that about 70% of patients will produce anti-insulin antibodies after some time e...Ⅰ. INTRODUCTIONImmune reaction remains a challenging problem in the clinical application of various insulin preparations. It is known that about 70% of patients will produce anti-insulin antibodies after some time even if highly pure insulin is used to treat diabetes. Therefore,it is both theoretically and practically significant to understand the molecular basis of insulin immune reaction and to find new insulin preparations with low antigenicity and full bioactivity.展开更多
Ⅰ. INTRODUCTIONInsulin is a hormone protein which has been investigated in a very broad and deep scope. On the basis of the abundant knowledge on its structure-function relationship, it has been an important subject ...Ⅰ. INTRODUCTIONInsulin is a hormone protein which has been investigated in a very broad and deep scope. On the basis of the abundant knowledge on its structure-function relationship, it has been an important subject for insulin studies trying to reconstitute novel insulin derivatives with some special biological activities, such as prolonged action, higher potence and lower-antigenicity, by protein engineering so as to be advantageous to the therapeutics of diabetes.展开更多
The crystal structure of 2 Zn porcine insulin has been refined at 1.2 resolution. The reciprocal space refinement was restrained by the incorporation of extensive chemical observations into the least squares equations...The crystal structure of 2 Zn porcine insulin has been refined at 1.2 resolution. The reciprocal space refinement was restrained by the incorporation of extensive chemical observations into the least squares equations. In addition to the non-hydrogen atoms, hydrogen atoms of protein, water molecules and the bulk solvent have been determined and refined. After two cycles of anisotropic refinement of non-hydrogen atoms of insulin, the final agreement factor was 0.128 for 20,005 reflexions (F_o>1σ(F_o)) in a spacing 1.2 and the root mean squares deviation from ideal covalent bond lengths was 0.021. On the electron density maps, the appearances of weight and shape of non-hydrogen atoms were very clear and reasonable. The anisotropic appearances of sulphur atoms could be seen clearly. After anisotropic refinement, the situation fit to the electron density was improved distinctly.展开更多
To enhance the stability of recombinant human collagen α1(I) chains(rhCOL1 A1) in production and purification stages, a gene fragment fusing COL1 A1 and insulin protein coding domains was synthesized and inserted int...To enhance the stability of recombinant human collagen α1(I) chains(rhCOL1 A1) in production and purification stages, a gene fragment fusing COL1 A1 and insulin protein coding domains was synthesized and inserted into the pPIC9 K expression vector. The fusion peptide-expressing Pichia pastoris strain was created by transformation.After optimization of shake flask cultures, the ultimate intracellular expression level of the insulin-collagen α1(I) chain fusion protein(INS-COL1 A1) reached about 300 mg·L^(-1), and no obvious protein degradation was found in the fermentation and purification processes. The His-tagged recombinant fusion protein was detected by western blotting and was effectively purified using Ni^(2+)-chelating chromatography. A prominent improvement in the stability of INS-COL1 A1 was observed compared to rhCOL1 A1 in vitro, and the rhCOL1 A1 released from the fusion protein was studied by LC–MS/MS and in bioassays. The results showed that the purified rhCOL1 A1 was consistent with the native protein in amino acid composition and had a similar biological compatibility. To our knowledge, this is the first study to demonstrate the use of insulin as a fusion protein to improve the stability of easily degradable proteins.展开更多
Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of ...Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of rhGH on gastric cancer. Methods: Nude mice were randomly divided into control group, cisplatin (DDP) group, rhGH group and DDP + rhGH group after human gastric cancer xenograft model of node mice was successfully founded and drugs were used for 6 days. We investigated volume of tumor, inhibitory rate of tumor and cell cycle by slide gauge and flow cytometry. In addition, We also respectively investigated insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) of blood serum of nude mice, IGF-ImRNA, insulin-like growth factor-I receptor (IGF-IR) mRNA and IGFBP-3 mRNA of xenograft of nude mice by enzyme linked immunosorbent assay (ELISA) and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) on the first day of completing use of drugs later. Results: Tumor grew obviously slowly and tumor inhibitory rate obviously rose in DDP group and DDP + rhGH group compared with control group and rhGH group (p p p < 0.05). Expressions of IGF-I mRNA and IGF-IR mRNA were not obviously different in all groups. But expression of IGFBP-3 mRNA obviously increased in rhGH group, DDP group and DDP + rhGH group compared with control group;meanwhile, expression of IGFBP-3 mRNA also obviously increased in DDP + rhGH group compared with control group, DDP group and rhGH group. Conclusion: Our results indicated rhGH in short-time use did not improve proliferation of human gastric cancer cells and its mechanism was possible that rhGH in short-time use raised simultaneously IGF-I and IGFBP-3 of blood serum and increased IGFBP-3 mRNA, but degraded ratio of IGF-I and IGFBP-3 of blood serum in human gastric cancer cells.展开更多
文摘AIM:To study the expression of human insulin gene in gastrointestinal tracts of diabetic rats. METHODS: pCMV.Ins, an expression plasmid of the human insulin gene, wrapped with chitosan nanoparticles, was transfected to the diabetic rats through lavage and coloclysis, respectively. Fasting blood glucose and plasma insulin levels were measured for 7 d. Reverse transcription polymerase chain reaction (RT-PCR) analysis and Western blot analysis were performed to confirm the expression of human insulin gene. RESULTS: Compared with the control group, the fasting blood glucose levels in the lavage and coloclysis groups were decreased significantly in 4 d (5.63 ± 0.48 mmol/L and 5.07 ± 0.37 mmol/L vs 22.12 ± 1.31 mmol/L, respectively, P < 0.01), while the plasma insulin levels were much higher (32.26 ± 1.81 μIU/mL and 32.79 ± 1.84 μIU/mL vs 14.23 ± 1.38 μIU/mL, respectively, P < 0.01). The human insulin gene mRNA and human insulin were only detected in the lavage and coloclysis groups. CONCLUSION: Human insulin gene wrapped with chitosan nanoparticles can be successfully transfected to rats through gastrointestinal tract, indicating that chitosan is a promising non-viral vector.
基金the National Natural Science Foundation of China, No.30770758, 81071114
文摘Human insulin-like growth factor 1-transfected umbilical cord blood neural stem cells were transplanted into a hypoxic-ischemic neonatal rat model via the tail vein. BrdU-positive cells at day 7 post-transplantation, as well as nestin- and neuron specific enolase-positive cells at day 14 were increased compared with those of the single neural stem cell transplantation group. In addition, the proportion of neuronal differentiation was enhanced. The genetically modified cell-transplanted rats exhibited enhanced performance in correctly crossing a Y-maze and climbing an angled slope compared with those of the single neural stem cell transplantation group. These results showed that human insulin-like growth factor 1-transfected neural stem cell transplantation promotes the recovery of the leaming, memory and motor functions in hypoxic-ischemic rats.
基金Supported by the Science and Technology Development Planning Foundation of Jilin Province of China(No.20030405)the Party and Government Administration "First-Leader-Hand" Science and Technology Project of Yunnan Province of Chi-na(No.2008QA028)
文摘The plant expression vector of choleratoxin B subunit(CTB)-human insulin(BA) fusion protein pBI121/(CTB-BA) was constructed first and then the Gynostemma Pentapyhllum Makino callus cell line that could express CTB-human insulin fusion protein was constructed and its hypoglycemic effect was evaluated in mice. The plant expression vector pBl 121/(CTB-BA) was digested with both BamI and SacI. Agrobacterium tumerfaciens strain LBA4404 was transformed with previously constructed recombinant plasmid pBI121/(CTB-BA) via the freeze thawing method, then CTB-BA gene was integrated to G Pentapyhllum Makino callus cells by co-culturing the cells with the transformed LBA4404 strain. The transformed G Pentapyhllum Makino callus cells were identified by DNA sequence assey and RT-PCR. The expressed product was identified by western-blot and its amount was tested by ELISA kit and its blood sugar decreasing effect was tested in mice. The sequences of synthetic CTB and human insulin genes(BA) were completely identical to those designed. Restriction map proved that the length of gene fragment in- serted into expression vector pBI121 was consistent with that expected. The sequence of genomic DNA of expressed product was completely identical to that designed. The result of RT-PCR was consistent with that expected. The expressed product showed a specific band with a relative molecular mass of 17000 by Western-blot. The human insulin expression amount was 6.03 μIU/mL according to the ELISA result. The animal test showed that only the G Pentapyhllum Makino callus cell line itself showed activity in decreasing the blood sugar of mice, however, the activity of the transformed G Pentapyhllum Makino callus cells was much higher, The plant expression vector pBI121/(CTB-BA) was constructed and expressed in the G Pentapyhllum Makino callus cells successfully for the first time. The trans- formed G Pentapyhllum Makino callus cells showed high activity in decreasing the blood sugar of mice. This study developed a new way for the development of oral administration insulin.
文摘We report a 64-year-old female patient with an insulin allergy. She was treated with a combination of oral antihistamines, topical hydrocortisone cream, and moisturizing agents, which resulted in the improvement of eczema and intense pruritus. To evaluate insulin allergy, intradermal skin tests were performed with several insulin agents for clinical use and 0.9% NaCl. Skin testing with semisynthetic human insulin resulted in local, immediate skin reactions such as itchy erythema and wheals. Furthermore, we analyzed our case and 25 Japanese cases of insulin allergy previously reported in the literature as far as we know. Interestingly, the number of male patients was approximately two times higher than that of female, and the insulin-specific IgE antibody test was positive in 21 patients. We should keep the possibility of human insulin allergy in mind and prepare for it when initiating human insulin therapy.
基金supported by grants from the Natural Science Foundation of Heilongjiang Province(No.ZJY0505)the Innovation of Foundation of Outstanding Teachers of Heilongjiang Provincial University(No.1054G026)
文摘BACKGROUND: Mesenchymal stem cells derived from human umbilical cord blood (UCB-MSCs) have good research and application prospects in the treatment of diabetes. We once induced UCB-MSCs to differentiate into insulin-producing cells (IPCs) in vitro, but we did not know the functions of these cells in vivo. The aim of this study was to assess the functional effects of IPCs on insulin secretion and their role in the treatment of diabetes in vivo. METHODS: UCB-MSCs were induced to IPCs by an inducing protocol with extracellular matrix gel. BALB/C nude mice were made hyperglycemic by intraperitoneal injection of streptozotocin. The diabetic mice were transplanted with 1x10(7) IPCs under the renal capsule or with phosphate-buffered saline as a control. After transplantation, the grafts were analyzed by immunocytochemistry for the expression of human insulin; the serum human insulin levels were measured; and blood glucose and body weight status were monitored. RESULTS: Immunofluorescence showed that numerous IPCs under the kidney capsule were insulin-positive. On day 14 after transplantation, the serum human insulin level of the treatment group (n=9) averaged 0.44 +/- 0.12 mU/L, which was higher than that of the control group (n=9) that did not express insulin (t=10.842, P<0.05). The diabetic mice remained hyperglycemic and kept losing body weight after IPC transplantation, and there was no significant difference in the control group. CONCLUSION: IPCs differentiated from UCB-MSCs generate human insulin in diabetic mice, but more research is needed to make further use of them to regulate hyperglycemia and body weight in vivo. (Hepatobiliary Pancreat Dis Int 2009; 8: 255-260)
文摘The resorption of the transplanted fat over time limited the use of autologous fat for the reconstruction of soft tissue defect. Tissue engineering (TE) adipose with silk fibroin scaffold could be a promising substitute for soft tissue filling. In this study, we try to develop a tissue engineering adipose in vitro by seeding silk fibroin scaffold with human umbilical cord mesenchymal stem cells (hUCMSCs) after transfected with recombinant human insulin gene lentivirus. Our aim was to observe the effects of the insulin gene transfection on the adipogenesis of hUCMSCs when cultured with silk fibroin scaffolds. The hUCMSCs infected with recombinant lentiviral pLenti6.3-insulin-IRES-EGFP were seeded on silk fibroin scaffolds and cultured in adipogenic differentiation medium for 5 - 7 days. The expression of adipogenic gene PPARγ-2 was tested by RT-PCR after 7 days culture of adipogenic induction. The accumulation of cytoplasmic droplets of neutral lipids was assessed by Oil Red O staining. The RNA and protein expression of transfected insulin gene in hUCMSCs were detected by QPCR and western blot. The effect of recombinant lentivirus transfection on the growth and proliferation of hUCMSCs was observed by MTT test. We observed that the 2-ΔΔCt value of insulin gene expression of hUCMSCs in the transfected group was 300.25 times higher than that in the untransfected group. The western blot showed that a positive band was discerned at the site of a relative molecular mass of 8 × 103 Dalton in transfected group. After adipogenic culture for 7 days, under the fluorescent inverted phase-contrast microscope, after Oil Red O staining, a lot of adipocytes appeared in silk fibroin scaffold;round adipose droplets showed intracellularly;the size of the adipocytes was not homogenous, and the density of adipocytes in transfected group was significantly higher than that in untransfected group (P = 0.007, P < 0.01). RT-PCR results showed that the expression of adipogenic gene PPARγ-2 in transfected group was much stronger than that in untransfected group. MTT test showed that there was no significant difference in optical density (A) at each time point between transfected group and nontransfected group (P = 0.056, P > 0.05). And there was also no significant difference in optical density (A) between cell group and cell-scalffold group (P = 0.066, P > 0.05). We concluded that insulin gene could obviously promote the adipogenic differentiation of hUCMSCs, and a tissue engineering adipose could be constructed by the silk fibroin scaffolds seeded with human insulin gene-modified hUCMSCs effectively in vitro.
文摘In the present study, the cleavage activities of both recombinant and bovine enzymes (trypsin and carboxy peptidase B) were determined using proinsulin fusion protein. The proteolysis products were analyzed with HPLC. We found that recombinant enzymes had stronger activities and produced fewer by-products. In addition, recombinant enzymes were more efficient in the production of human insulin than bovine enzymes.
基金Project supported by the National High Technology Program of China.
文摘A synthetic single-chain porcine insulin precursor (PIP) gene and an α-mating factor leader sequence (αMFL) gene obtained by the PCR method are inserted between the promoter and 3’-terminating sequence of the alcohol dehydrogenase gene ADH1 in plasmid pVT102-U to form plasmid pVT102-U/α MFL-PIP. The single-chain insulin precursor is expressed and secreted to the culture medium by Saccharomyces cererisiae transformed by pVT102-U/αMFL-PIP. The precursor is purified and converted into human insulin by tryptic transpeptidation. The purified human insulin is fully active and can be crystallized. The overall yield of human insulin is 25 mg per liter of culture medium.
文摘Background Glycemic control prevents onset and progression of diabetes-related long-term complications. The objective of this study was to demonstrate that twice daily insulin lispro low mix 25 is noninferior to twice daily human insulin mix 30/70 in achieving glycemic control as measured by hemoglobin Alc (HbAlc), from baseline to endpoint, in patients with type 1 or 2 diabetes. Methods In this phase IV, crossover, open-label, multicenter study, 117 Chinese patients with diabetes were randomly assigned to one of two treatment sequence groups. One group received 12-week treatment with twice daily human insulin mix 30/70 followed by 12-week treatment with twice daily insulin lispro low mix 25, while the other group received the reverse treatment sequence. HbAlc, baseline-to-endpoint change in HbAlc, proportion of patients achieving target HbAlc ≤ 7% and 〈 6.5%, fasting blood glucose, and daily insulin doses were measured for each period. Safety and tolerability were also assessed. Results A statistically significant reduction (P≤0.0001) of HbAlc was achieved after each treatment (human insulin mix 30/70: mean HbA1c=7.91% (95% CI: 7,67%, 8.15%); insulin lispro low mix 25: mean HbA1c=7.96% (95% CI: 7.72%, 8.20%)). The 95% Cl (-0.20, 0.10) of the difference between the two treatments satisfied the prespecified noninferiority margin of 0.3% (lower limit of 95% CI 〉 -0.3%). No statistically significant differences between treatments were observed for any of the secondary efficacy measures. The incidence of treatment-emergent adverse events and hypoglycemia between the two treatments and treatment sequence groups was similar. Three serious adverse events were reported (human insulin mix 30/70 group: 2 patients (1.7%, hypoglycemic coma and cardiac failure); insulin lispro low mix 25 group: 1 patient (0.9%, stroke)). All serious adverse events were resolved and no patients died during the study. Conclusion The results support noninferiority of twice daily insulin lispro low mix 25 versus twice daily human insulin mix 30/70 in HbAlc control in Chinese patients with type 1 or 2 diabetes.
基金Project supported by UNIDO(91/048)and High-Tech Program of China(103-19-01).
文摘It has long been found that insulin in acid solution is unstable. The main reason is that the A-chain C-terminal residue, asparagine, is very susceptible to acid hydrolysis, thereby a covalent-dimer formation takes place readily due to the deamidation of this residue. As a number of pharmaceutical preparations of insulin are acidic solutions, this kind of instability has brought about a serious problem on purity and storage of this preparation in
基金Project supported by the UNIDO(91/048/)and the "863" High-Tech Plan of China.
文摘Ⅰ. INTRODUCTIONThe chemical stability of human insulin preparations is directly related to the residue of A21-Asn at C-terminal of A chain and can be distinctly increased by substituting the A21 residue in the way of protein engineering. Studying the fine three-dimensional structures
基金Supported by a grant of UNIDO (91/048/CW)and "863" high technology program
文摘Ⅰ. INTRODUCTIONImmune reaction remains a challenging problem in the clinical application of various insulin preparations. It is known that about 70% of patients will produce anti-insulin antibodies after some time even if highly pure insulin is used to treat diabetes. Therefore,it is both theoretically and practically significant to understand the molecular basis of insulin immune reaction and to find new insulin preparations with low antigenicity and full bioactivity.
基金Project supported by a grant of "863" high technology.
文摘Ⅰ. INTRODUCTIONInsulin is a hormone protein which has been investigated in a very broad and deep scope. On the basis of the abundant knowledge on its structure-function relationship, it has been an important subject for insulin studies trying to reconstitute novel insulin derivatives with some special biological activities, such as prolonged action, higher potence and lower-antigenicity, by protein engineering so as to be advantageous to the therapeutics of diabetes.
基金Project supported by UNIDO Grant (91/048) and the High-Technology Program of China.
文摘The crystal structure of 2 Zn porcine insulin has been refined at 1.2 resolution. The reciprocal space refinement was restrained by the incorporation of extensive chemical observations into the least squares equations. In addition to the non-hydrogen atoms, hydrogen atoms of protein, water molecules and the bulk solvent have been determined and refined. After two cycles of anisotropic refinement of non-hydrogen atoms of insulin, the final agreement factor was 0.128 for 20,005 reflexions (F_o>1σ(F_o)) in a spacing 1.2 and the root mean squares deviation from ideal covalent bond lengths was 0.021. On the electron density maps, the appearances of weight and shape of non-hydrogen atoms were very clear and reasonable. The anisotropic appearances of sulphur atoms could be seen clearly. After anisotropic refinement, the situation fit to the electron density was improved distinctly.
基金Supported by the National Natural Science Foundation of China(21676214,21576160,21506171)Shaanxi Key Laboratory of Degradable Biomedical Materials Program(2014SZS07-K04,2014SZS07-P05,15JS105,15JS106,2014SZS07-Z01,2014SZS07-K03)Shaanxi R&D Center of Biomaterials and Fermentation Engineering Program(2015HBGC-04)
文摘To enhance the stability of recombinant human collagen α1(I) chains(rhCOL1 A1) in production and purification stages, a gene fragment fusing COL1 A1 and insulin protein coding domains was synthesized and inserted into the pPIC9 K expression vector. The fusion peptide-expressing Pichia pastoris strain was created by transformation.After optimization of shake flask cultures, the ultimate intracellular expression level of the insulin-collagen α1(I) chain fusion protein(INS-COL1 A1) reached about 300 mg·L^(-1), and no obvious protein degradation was found in the fermentation and purification processes. The His-tagged recombinant fusion protein was detected by western blotting and was effectively purified using Ni^(2+)-chelating chromatography. A prominent improvement in the stability of INS-COL1 A1 was observed compared to rhCOL1 A1 in vitro, and the rhCOL1 A1 released from the fusion protein was studied by LC–MS/MS and in bioassays. The results showed that the purified rhCOL1 A1 was consistent with the native protein in amino acid composition and had a similar biological compatibility. To our knowledge, this is the first study to demonstrate the use of insulin as a fusion protein to improve the stability of easily degradable proteins.
文摘Aim: To study effects of recombinant human growth hormone (rhGH) on growth hormone-insulin-like growth factor axis (GH-IGFs) of human gastric cancer cell in vivo in order to reveal part mechanism of growth effects of rhGH on gastric cancer. Methods: Nude mice were randomly divided into control group, cisplatin (DDP) group, rhGH group and DDP + rhGH group after human gastric cancer xenograft model of node mice was successfully founded and drugs were used for 6 days. We investigated volume of tumor, inhibitory rate of tumor and cell cycle by slide gauge and flow cytometry. In addition, We also respectively investigated insulin-like growth factor-I (IGF-I) and insulin-like growth factor binding protein-3 (IGFBP-3) of blood serum of nude mice, IGF-ImRNA, insulin-like growth factor-I receptor (IGF-IR) mRNA and IGFBP-3 mRNA of xenograft of nude mice by enzyme linked immunosorbent assay (ELISA) and semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) on the first day of completing use of drugs later. Results: Tumor grew obviously slowly and tumor inhibitory rate obviously rose in DDP group and DDP + rhGH group compared with control group and rhGH group (p p p < 0.05). Expressions of IGF-I mRNA and IGF-IR mRNA were not obviously different in all groups. But expression of IGFBP-3 mRNA obviously increased in rhGH group, DDP group and DDP + rhGH group compared with control group;meanwhile, expression of IGFBP-3 mRNA also obviously increased in DDP + rhGH group compared with control group, DDP group and rhGH group. Conclusion: Our results indicated rhGH in short-time use did not improve proliferation of human gastric cancer cells and its mechanism was possible that rhGH in short-time use raised simultaneously IGF-I and IGFBP-3 of blood serum and increased IGFBP-3 mRNA, but degraded ratio of IGF-I and IGFBP-3 of blood serum in human gastric cancer cells.