Insulin gene structure and function: a review of studies using recombinant DNA methodology (original) (raw)
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Recombinant Human Insulins – Clinical Efficacy and Safety in Diabetes Therapy
European Endocrinology
Insulin replacement therapy is the standard of care for patients with type 1 and advanced type 2 diabetes mellitus. Porcine and bovine pancreatic tissue was the source of the hormone for many years, followed by semisynthetic human insulin obtained by modification of animal insulin. With the development of recombinant DNA technology, recombinant (biosynthetic) human insulin became available in large amounts by biosynthesis in microorganisms (Escherichia coli, yeast) providing reliable supplies of the hormone worldwide at affordable costs. The purity and pharmaceutical quality of recombinant human insulin was demonstrated to be superior to animal and semisynthetic insulin and patients with diabetes could be safely and effectively transferred from animal or semisynthetic human insulin to recombinant human insulin with no change expected in insulin dose. The decision for change remains a clinical objective, follow-up after any change of insulin product is recommended to confirm clinical...
Science (New York, N.Y.), 1981
The arrangement of the human insulin gene in DNA from 87 individuals was analyzed by the Southern blot hybridization technique with a cloned genomic human insulin probe. Insertions of 1.5 to 3.4 kilobase pairs in the 5'-flanking region of the gene were found in DNA from 38 individuals. These insertions occurred within 1.3 kilobase pairs of the transcription initiation site. In contrast, no insertions were observed in the region 3' to the coding sequence. The prevalence of these insertions in type 2 diabetes was significantly greater than in the other groups (P less than .001). The limitation of this striking length polymorphism to a potential promoter region suggests that these insertions may play a role in insulin gene expression.
Human insulin-related DNA sequences map to chromosomes 2 and 11
Somatic Cell and Molecular Genetics, 1986
The insulin-related hormone family consists of four known peptides: insulin, the insulin-like growth factors I and 1I, and relaxin. To investigate the hypothesis that the family contains additional members, we have isolated a series of human genomic clones using the insulin gene as a hybridization probe. Two of these single copy DNA sequences, hlrl and hlr2, have been localized to chromosome 2 and 1 lpl l~ql 3, respectively, by Southern blot analysis of mouse-human somatic cell hybrids, a result consistent with other evidence supporting the dispersal of the insulin gene family throughout the genome. Although a biological function for these DNA sequences has not yet been established, hlrl and hlr2 are potentially useful as molecular probes for mapping, by analysis of restriction fragment length polymorphisms (RFLP), genetic disorders linked to chromosomes 2 or I I.
Effect of 5′-Flanking Sequence Deletions on Expression of the Human Insulin Gene in Transgenic Mice
Molecular Endocrinology, 1990
Expression of the human insulin gene was examined in transgenic mouse lines carrying the gene with various lengths of DNA sequences 5' to the transcription start site (+1). Expression of the transgene was demonstrated by 1) the presence of human Cpeptide in urine, 2) the presence of specific transcripts in pancreas, but not in other tissues, 3) the specific immunofluorescence staining of pancreatic islets for human C-peptide, and 4) the synthesis and accumulation of human (pro)insulin in isolated islets. Deletions in the injected DNA fragment of sequences upstream from positions-353,-258, and-168 allowed correct initiation of the transcripts and cell specificity of expression, while quantitative expression gradually decreased. Deletion to-5 8 completely abolished the expression of the gene. The amount of human product that in mice harboring the longest fragment contributes up to 50% of the total insulin does not alter the normal proportion of mice insulins I and II. These results suggest that expression of the human insulin gene in vivo results from the cooperation of several c/s-regulatory elements present in the various deleted fragments. With none of the deletions used, expression of the transgene was observed in cell types other than /3-islet cells.
Current strategies and perspectives in insulin gene therapy for diabetes
Expert Review of Endocrinology & Metabolism, 2007
Insulin gene therapy is an approach that might overcome the weakness of islet cell therapy owing to its vulnerability to autoimmune attack. There are several mandatory conditions for successful insulin gene therapy. Efficient insulin gene therapy should have an effective insulin gene delivery mechanism, a system of regulation of the insulin biosynthesis that responds to glucose within extremely narrow physiological limits, a system of insulin processing into its active form and a choice of appropriate target cells, which possess biochemical characteristics similar to β cells, but are not targets for β-cell-specific self-reactivity. In this article, advantages and disadvantages of non-β-cell types that are most likely to be used for generating surrogate insulin-producing β cells are compared. Current achievements in insulin gene therapy are critically evaluated and future challenges are discussed.
Diabetes Care, 1982
The affinity of human (recombinant DNA) insulin and porcine insulin to preformed IgG-insulin antibodies of insulin-treated diabetic individuals was studied in 29 insulin-treated diabetic patients. The binding of 125I-human insulin and 125I-porcine insulin with antibodies was similar in the group of patients without insulin resistance (N = 25). The sera of insulin-resistant diabetic patients (N = 4), containing very high IgG-insulin immunoglobulins, showed a significantly lower affinity for human insulin compared with porcine insulin (P < 0.01). All four patients with insulin-antibody-mediated insulin resistance were positive for HLA-DR4, but negative for -DR3, supporting the concept of an immunogenetically transferred anti-insulin immune response in insulin-treated diabetic individuals. Based on the reduced binding of human insulin to IgG-antibodies of very high titers in patients with insulin resistance, a potential therapeutic advantage of human insulin therapy can be expected ...
Proteomic Changes to the Updated Discovery of Engineered Insulin and Its Analogs: Pros and Cons
Current Issues in Molecular Biology
The destruction of β-cells of the pancreas leads to either insulin shortage or the complete absence of insulin, which in turn causes diabetes Mellitus. For treating diabetes, many trials have been conducted since the 19th century until now. In ancient times, insulin from an animal’s extract was taken to treat human beings. However, this resulted in some serious allergic reactions. Therefore, scientists and researchers have tried their best to find alternative ways for managing diabetes with progressive advancements in biotechnology. However, a lot of research trials have been conducted, and they discovered more progressed strategies and approaches to treat type I and II diabetes with satisfaction. Still, investigators are finding more appropriate ways to treat diabetes accurately. They formulated insulin analogs that mimic the naturally produced human insulin through recombinant DNA technology and devised many methods for appropriate delivery of insulin. This review will address the...
Genetic Control of Insulin Receptors
Proceedings of The National Academy of Sciences - PNAS, 1981
Insulin-binding activity was measured in hepatocyte suspensions and liver membrane preparations from newborn mice homozygous for a perinatal-lethal deletion at and around the albino locus in chromosome 7. Cell suspensions and membrane preparations from the mutant mice exhibited only 20-25% of the specific hormone-binding activity observed in comparable preparations from their homozygous normal and heterozygous littermates. The decrease in insulin-binding activity appears to be attributable to a decrease in the number of insulin receptor sites per cell rather than to a change in receptor affinity. Gene sequences deleted at and around the albino locus are therefore instrumental in the regulation of insulin receptor concentration rather than in coding for the insulin receptor itself. The results of the present studies extend the identification of the regulatory functions exerted by the genes around the albino locus of the mouse.
New England Journal of Medicine, 1983
We sought to determine whether differences in the human insulin gene or its immediate flanking sequences could be found in diabetes. Peripheral leukocyte DNA from 217 unrelated persons, including blacks, whites, and Pima Indians, was analyzed by restriction-enzyme digestion, blotting to nitrocellulose filters, and hybridization to cloned [32P]insulin-gene probes. A region of length variation including deletions (0.1 to 0.2 kilobase pairs) or insertions (0.6 to 5.5 kb) of DNA was found only in the immediate 5&amp;#39; flanking region in 33 per cent of the genes examined. A 1.6-kb insertion accounted for 80 per cent of the polymorphism. This variant was found more often in subjects with non-insulin-dependent diabetes than in nondiabetics, regardless of race (P = 0.011). Length polymorphism in the 5&amp;#39; flanking region of the insulin gene may provide a genetic marker for non-insulin-dependent diabetes.