{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T00:03:39Z","timestamp":1783555419220,"version":"3.55.0"},"reference-count":0,"publisher":"Bioscientifica","issue":"3","content-domain":{"domain":["journals.bioscientifica.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[2003,6,1]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Long-term constitutive secretion of insulin by implantation of ex vivo transfected cells such as fibroblasts or myoblasts or in situ by intramuscular injection of naked plasmid DNA provides a potential approach to gene therapy for diabetes mellitus. A mechanism for regulating insulin secretion will be necessary to realize the therapeutic potential of this approach. A second obstacle is the inability of non-endocrine host cells to fully process proinsulin. Therefore, alteration of the wild-type cDNA will be necessary to achieve processing of proinsulin by endogenous endoproteases within these cells. The cDNAs for beta-galactosidase (beta), human wild-type proinsulin (hppI1) and a mutated construct (hppI4), in which the dibasic PC2 and PC3 cleavage sites had been altered to form furin cleavage sites, were sub-cloned into four vectors (pCR3, pVR1012, pIRES, pTRE), including a tetracycline responsive plasmid (pTRE) that requires co-transfection with another plasmid encoding a transactivator (pTet-off) for transgene expression. Transient transfection of the COS-7 fibroblast cell line with these constructs was performed using DEAE-dextran and liposomes. Analysis of vector efficiencies revealed that pTRE\/pTet-off&amp;gt;pIRES&amp;gt;pCR3&amp;gt;pVR1012. Further analysis demonstrated total pro\/insulin secretion of 2.33 ng\/10(6) cells\/24 h with &amp;gt; or =25% processed to insulin in hppI-1.pTRE\/pTet-off-transfected cells compared with 0.39 ng\/10(6) cells\/24 h and &amp;gt;70% processing in hppI-4.pTRE\/pTet-off-transfected cells. In co-transfection studies with pTRE-hppI1\/pTet-off and pTRE-hppI4\/pTet-off constructs, pro\/insulin secretion was inhibited to 65-66% and 36-38% of control (100%) in the presence of 0.01 and 0.1 microg\/ml tetracycline respectively over a 24-h incubation period. Furthermore, reversal of tetracycline inhibition was demonstrated for pTRE-hppI1\/pTet-off- and pTRE-hppI4\/pTet-off-transfected cells. After a 48-h incubation with 1.0 microg\/ml tetracycline, total pro\/insulin levels were 10 and 14% compared with untreated cells respectively. On tetracycline removal, total proinsulin levels increased and were equivalent to untreated groups 72 h later. In conclusion, regulation of fully processed human insulin secretion has been achieved in a transiently transfected non-endocrine cell line.<\/jats:p>","DOI":"10.1677\/jme.0.0300331","type":"journal-article","created":{"date-parts":[[2004,12,2]],"date-time":"2004-12-02T18:43:59Z","timestamp":1102013039000},"page":"331-346","update-policy":"https:\/\/doi.org\/10.1530\/crossmarkpolicy-6","source":"Crossref","is-referenced-by-count":6,"title":["Tetracycline-regulated secretion of human insulin in a transfected non-endocrine cell line"],"prefix":"10.1530","volume":"30","author":[{"given":"KT","family":"Scougall","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"CA","family":"Maltin","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"JA","family":"Shaw","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"416","container-title":["Journal of Molecular Endocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/jme.bioscientifica.com\/view\/journals\/jme\/30\/3\/331.xml","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.bioscientifica.com\/jme\/article-pdf\/30\/3\/331\/47787\/331.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/journals.bioscientifica.com\/jme\/article-pdf\/30\/3\/331\/47787\/331.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T11:58:22Z","timestamp":1783511902000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.bioscientifica.com\/jme\/article\/30\/3\/331\/6471\/Tetracycline-regulated-secretion-of-human-insulin"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2003,6,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[2003,6,1]]}},"URL":"https:\/\/doi.org\/10.1677\/jme.0.0300331","relation":{},"ISSN":["1479-6813","0952-5041"],"issn-type":[{"value":"1479-6813","type":"electronic"},{"value":"0952-5041","type":"print"}],"subject":[],"published":{"date-parts":[[2003,6,1]]}}}