Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells
Insulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual...
| Main Authors: | , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-09-01
|
| Series: | Biomolecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-273X/11/9/1382 |
| _version_ | 1797520047448522752 |
|---|---|
| author | Pinki Nandi Chloe E. Jang Kyle Biggar Chidambra D. Halari Thomas Jansson Madhulika B. Gupta |
| author_facet | Pinki Nandi Chloe E. Jang Kyle Biggar Chidambra D. Halari Thomas Jansson Madhulika B. Gupta |
| author_sort | Pinki Nandi |
| collection | DOAJ |
| description | Insulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual IGFBP-1 secretion/phosphorylation are poorly understood. Using decidualized primary human endometrial stromal cells (HESCs) from first-trimester placenta, we tested the hypothesis that mTORC1 signaling mechanistically links hypoxia to decidual IGFBP-1 secretion/phosphorylation. Hypoxia inhibited mechanistic target of rapamycin (mTORC1) (p-P70-S6K/Thr389, −47%, <i>p</i> = 0.038; p-4E-BP1/Thr70, −55%, <i>p</i> = 0.012) and increased IGFBP-1 (total, +35%, <i>p</i> = 0.005; phosphorylated, Ser101/+82%, <i>p</i> = 0.018; Ser119/+88%, <i>p</i> = 0.039; Ser 169/+157%, <i>p</i> = 0.019). Targeted parallel reaction monitoring-mass spectrometry (PRM-MS) additionally demonstrated markedly increased dual IGFBP-1 phosphorylation (pSer98+Ser101; pSer169+Ser174) in hypoxia. IGFBP-1 hyperphosphorylation inhibited IGF-1 receptor autophosphorylation/ Tyr1135 (−29%, <i>p</i> = 0.002). Furthermore, silencing of tuberous sclerosis complex 2 (TSC2) activated mTORC1 (p-P70-S6K/Thr389, +68%, <i>p</i> = 0.038; p-4E-BP1/Thr70, +30%, <i>p</i> = 0.002) and reduced total/site-specific IGFBP-1 phosphorylation. Importantly, TSC2 siRNA prevented inhibition of mTORC1 and the increase in secretion/site-specific IGFBP-1 phosphorylation in hypoxia. PRM-MS indicated concomitant changes in protein kinase autophosphorylation (CK2/Tyr182; PKC/Thr497; PKC/Ser657). Overall, mTORC1 signaling mechanistically links hypoxia to IGFBP-1 secretion/phosphorylation in primary HESC, implicating decidual mTORC1 inhibition as a novel mechanism linking uteroplacental hypoxia to fetal growth restriction. |
| first_indexed | 2024-03-10T07:51:19Z |
| format | Article |
| id | doaj.art-782f928ab7c54875833238e0b7f55aeb |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-10T07:51:19Z |
| publishDate | 2021-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-782f928ab7c54875833238e0b7f55aeb2023-11-22T12:11:50ZengMDPI AGBiomolecules2218-273X2021-09-01119138210.3390/biom11091382Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal CellsPinki Nandi0Chloe E. Jang1Kyle Biggar2Chidambra D. Halari3Thomas Jansson4Madhulika B. Gupta5Departments of Pediatrics, University of Western Ontario, London, ON N6A 5C1, CanadaDepartment of Biochemistry, University of Western Ontario, London, ON N6A 5C1, CanadaInstitute of Biochemistry and Department of Biology, Carleton University, Ottawa, ON K1S 5B6, CanadaDepartments of Anatomy and Cell Biology, University of Western Ontario, London, ON N6A 3K7, CanadaDepartment of Obstetrics and Gynecology, Division of Reproductive Sciences, University of Colorado Anschutz Medical Campus, Aurora, CO 80045, USADepartments of Pediatrics, University of Western Ontario, London, ON N6A 5C1, CanadaInsulin-like growth factor-1 (IGF-1) bioavailability in pregnancy is governed by IGF binding protein (IGFBP-1) and its phosphorylation, which enhances the affinity of IGFBP-1 for the growth factor. The decidua is the predominant source of maternal IGFBP-1; however, the mechanisms regulating decidual IGFBP-1 secretion/phosphorylation are poorly understood. Using decidualized primary human endometrial stromal cells (HESCs) from first-trimester placenta, we tested the hypothesis that mTORC1 signaling mechanistically links hypoxia to decidual IGFBP-1 secretion/phosphorylation. Hypoxia inhibited mechanistic target of rapamycin (mTORC1) (p-P70-S6K/Thr389, −47%, <i>p</i> = 0.038; p-4E-BP1/Thr70, −55%, <i>p</i> = 0.012) and increased IGFBP-1 (total, +35%, <i>p</i> = 0.005; phosphorylated, Ser101/+82%, <i>p</i> = 0.018; Ser119/+88%, <i>p</i> = 0.039; Ser 169/+157%, <i>p</i> = 0.019). Targeted parallel reaction monitoring-mass spectrometry (PRM-MS) additionally demonstrated markedly increased dual IGFBP-1 phosphorylation (pSer98+Ser101; pSer169+Ser174) in hypoxia. IGFBP-1 hyperphosphorylation inhibited IGF-1 receptor autophosphorylation/ Tyr1135 (−29%, <i>p</i> = 0.002). Furthermore, silencing of tuberous sclerosis complex 2 (TSC2) activated mTORC1 (p-P70-S6K/Thr389, +68%, <i>p</i> = 0.038; p-4E-BP1/Thr70, +30%, <i>p</i> = 0.002) and reduced total/site-specific IGFBP-1 phosphorylation. Importantly, TSC2 siRNA prevented inhibition of mTORC1 and the increase in secretion/site-specific IGFBP-1 phosphorylation in hypoxia. PRM-MS indicated concomitant changes in protein kinase autophosphorylation (CK2/Tyr182; PKC/Thr497; PKC/Ser657). Overall, mTORC1 signaling mechanistically links hypoxia to IGFBP-1 secretion/phosphorylation in primary HESC, implicating decidual mTORC1 inhibition as a novel mechanism linking uteroplacental hypoxia to fetal growth restriction.https://www.mdpi.com/2218-273X/11/9/1382fetal developmentplacental insufficiencyhumansinsulin-like growth factor IreceptorIGF Type 1 |
| spellingShingle | Pinki Nandi Chloe E. Jang Kyle Biggar Chidambra D. Halari Thomas Jansson Madhulika B. Gupta Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells Biomolecules fetal development placental insufficiency humans insulin-like growth factor I receptor IGF Type 1 |
| title | Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells |
| title_full | Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells |
| title_fullStr | Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells |
| title_full_unstemmed | Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells |
| title_short | Mechanistic Target of Rapamycin Complex 1 Signaling Links Hypoxia to Increased IGFBP-1 Phosphorylation in Primary Human Decidualized Endometrial Stromal Cells |
| title_sort | mechanistic target of rapamycin complex 1 signaling links hypoxia to increased igfbp 1 phosphorylation in primary human decidualized endometrial stromal cells |
| topic | fetal development placental insufficiency humans insulin-like growth factor I receptor IGF Type 1 |
| url | https://www.mdpi.com/2218-273X/11/9/1382 |
| work_keys_str_mv | AT pinkinandi mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells AT chloeejang mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells AT kylebiggar mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells AT chidambradhalari mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells AT thomasjansson mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells AT madhulikabgupta mechanistictargetofrapamycincomplex1signalinglinkshypoxiatoincreasedigfbp1phosphorylationinprimaryhumandecidualizedendometrialstromalcells |