Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation
<p>Abstract</p> <p>Background</p> <p>A deficiency in <it>Perk </it>(EIF2AK3) causes multiple neonatal defects in humans known as the Wolcott Rallison syndrome. <it>Perk KO </it>mice exhibit the same array of defects including permanent neonatal d...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
BMC
2009-09-01
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| Series: | BMC Cell Biology |
| Online Access: | http://www.biomedcentral.com/1471-2121/10/61 |
| _version_ | 1818039357133553664 |
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| author | McGrath Barbara C Gupta Sounak Wei Jianwen Feng Daorong Cavener Douglas R |
| author_facet | McGrath Barbara C Gupta Sounak Wei Jianwen Feng Daorong Cavener Douglas R |
| author_sort | McGrath Barbara C |
| collection | DOAJ |
| description | <p>Abstract</p> <p>Background</p> <p>A deficiency in <it>Perk </it>(EIF2AK3) causes multiple neonatal defects in humans known as the Wolcott Rallison syndrome. <it>Perk KO </it>mice exhibit the same array of defects including permanent neonatal diabetes (PND). PND in mice was previously shown by us to be due to a decrease in beta cell proliferation and insulin secretion. The aim of this study was to determine if acute ablation of PERK in the 832/13 beta cells recapitulates these defects and to identify the primary molecular basis for beta cell dysfunction.</p> <p>Results</p> <p>The INS1 832/13 transformed rat beta cell line was transduced with a dominant-negative <it>Perk </it>transgene via an adenoviral vector. <it>AdDNPerk</it>-832/13 beta cells exhibited reduced expression of <it>insulin </it>and <it>MafA </it>mRNAs, reduced insulin secretion, and reduced cell proliferation. Although proinsulin content was reduced in <it>AdDNPerk</it>-832/13 beta cells, proinsulin was abnormally retained in the endoplasmic reticulum. A temporal study of the acute ablation of <it>Perk </it>revealed that the earliest defect seen was induced expression of two ER chaperone proteins, GRP78/BiP and ERp72. The oxidized states of ERp72 and ERp57 were also increased suggesting an imbalance in the redox state of the ER.</p> <p>Conclusion</p> <p>Acute ablation of Perk in INS 832/13 beta cells exhibited all of the major defects seen in <it>Perk KO </it>mice and revealed abnormal expression and redox state of key ER chaperone proteins. Dysregulation of ER chaperone/folding enzymes ERp72 and GRP78/BiP occurred early after ablation of PERK function suggesting that changes in ER secretory functions may give rise to the other defects including reduced insulin gene expression, secretion, and cell proliferation.</p> |
| first_indexed | 2024-12-10T07:57:21Z |
| format | Article |
| id | doaj.art-56cb419cb95d4f86be108fc1d3100d00 |
| institution | Directory Open Access Journal |
| issn | 1471-2121 |
| language | English |
| last_indexed | 2024-12-10T07:57:21Z |
| publishDate | 2009-09-01 |
| publisher | BMC |
| record_format | Article |
| series | BMC Cell Biology |
| spelling | doaj.art-56cb419cb95d4f86be108fc1d3100d002022-12-22T01:56:52ZengBMCBMC Cell Biology1471-21212009-09-011016110.1186/1471-2121-10-61Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferationMcGrath Barbara CGupta SounakWei JianwenFeng DaorongCavener Douglas R<p>Abstract</p> <p>Background</p> <p>A deficiency in <it>Perk </it>(EIF2AK3) causes multiple neonatal defects in humans known as the Wolcott Rallison syndrome. <it>Perk KO </it>mice exhibit the same array of defects including permanent neonatal diabetes (PND). PND in mice was previously shown by us to be due to a decrease in beta cell proliferation and insulin secretion. The aim of this study was to determine if acute ablation of PERK in the 832/13 beta cells recapitulates these defects and to identify the primary molecular basis for beta cell dysfunction.</p> <p>Results</p> <p>The INS1 832/13 transformed rat beta cell line was transduced with a dominant-negative <it>Perk </it>transgene via an adenoviral vector. <it>AdDNPerk</it>-832/13 beta cells exhibited reduced expression of <it>insulin </it>and <it>MafA </it>mRNAs, reduced insulin secretion, and reduced cell proliferation. Although proinsulin content was reduced in <it>AdDNPerk</it>-832/13 beta cells, proinsulin was abnormally retained in the endoplasmic reticulum. A temporal study of the acute ablation of <it>Perk </it>revealed that the earliest defect seen was induced expression of two ER chaperone proteins, GRP78/BiP and ERp72. The oxidized states of ERp72 and ERp57 were also increased suggesting an imbalance in the redox state of the ER.</p> <p>Conclusion</p> <p>Acute ablation of Perk in INS 832/13 beta cells exhibited all of the major defects seen in <it>Perk KO </it>mice and revealed abnormal expression and redox state of key ER chaperone proteins. Dysregulation of ER chaperone/folding enzymes ERp72 and GRP78/BiP occurred early after ablation of PERK function suggesting that changes in ER secretory functions may give rise to the other defects including reduced insulin gene expression, secretion, and cell proliferation.</p>http://www.biomedcentral.com/1471-2121/10/61 |
| spellingShingle | McGrath Barbara C Gupta Sounak Wei Jianwen Feng Daorong Cavener Douglas R Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation BMC Cell Biology |
| title | Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation |
| title_full | Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation |
| title_fullStr | Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation |
| title_full_unstemmed | Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation |
| title_short | Acute ablation of PERK results in ER dysfunctions followed by reduced insulin secretion and cell proliferation |
| title_sort | acute ablation of perk results in er dysfunctions followed by reduced insulin secretion and cell proliferation |
| url | http://www.biomedcentral.com/1471-2121/10/61 |
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