Ligand-regulated secretion of recombinant annexin V from cultured thyroid epithelial cells.
The exposure of anionic phospholipids on the external surface of injured endothelial cells and activated platelets is a primary biological signal to initiate blood coagulation. Disease conditions that promote the formation of ectopic thrombi result in tissue ischemia. Annexins, Ca2+-dependent anionic phospholipid binding proteins, are potential therapeutic agents for the inhibition of coagulation. We have designed a transgene that targets secretion of annexin V from cultured thyroid cells under the control of doxycycline. Our results indicate that annexin V in the endoplasmic reticulum (ER)/Golgi lumen does not affect the synthesis, processing, and secretion of thyroglobulin. ER luminal Ca2+ was moderately increased and can be released by inositol 1,4,5-trisphosphate. Our study demonstrates that targeting and secretion of annexin V through the secretory pathway of mammalian cells does not adversely affect cellular function. Regulated synthesis and release of annexin V may exert anticoagulatory and anti-inflammatory effects systemically and may prove useful in further developing therapeutic strategies for conditions including antiphospholipid syndrome.
Wang
Xiuqiong
X
Department of Molecular and Cellular Physiology, University of Cincinnati, College of Medicine, Cincinnati, Ohio 45267-0576, USA.
Kaetzel
Marcia A
MA
Yoo
Sung E
SE
Kim
Paul S
PS
Dedman
John R
JR
D000595:Amino Acid Sequence; D000818:Animals; D017304:Annexin A5 / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002455:Cell Division; D002478:Cells, Cultured; D004318:Doxycycline / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D000939:Epitopes / Q000502:physiology; D018390:Gene Targeting; D006056:Golgi Apparatus / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D008024:Ligands; D008969:Molecular Sequence Data; D011499:Protein Processing, Post-Translational / Q000502:physiology; D021382:Protein Sorting Signals / Q000502:physiology; D051381:Rats; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D013954:Thyroglobulin / Q000378:metabolism; D013961:Thyroid Gland / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019076:Transgenes
D017304:Annexin A5; D000939:Epitopes; D008024:Ligands; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; D015544:Inositol 1,4,5-Trisphosphate; D013954:Thyroglobulin; D004318:Doxycycline; D002118:Calcium