New insights of subfertility among transplanted women: Immunosuppressive drug FK506 leads to calcium leak and oocyte activation before fertilization
JOURNAL OF CELLULAR BIOCHEMISTRY
Authors: Liu, Linlin; Yang, Man; Wang, Naiqiang; Li, Li; Chen, Zi-Jiang; Zhang, Cong
Abstract
FKBP12, known as FK506 binding protein, binds to immunosuppressive drug FK506, which must be taken by patients who received organ transplant. The side effect of FK506 is that women have difficulties in bearing a baby, so it is important to find the reason of their subfertility. This research explored the expression of FKBP12 in pre-implantation embryos and investigated its potential effect on reproduction. The results demonstrate that FKBP12 had good co-localization with endoplasmic reticulum and inositol-1, 4, 5- trisphosphate receptor in pre-implantation stages. Inhibiting FKBP12 by FK506 significantly increased the rate of 1-cell and fragmented embryos, greatly reduced the rate of 2-cell embryos during in vitro fertilization. When the mice received FK506 by gavage for 21 days, the calcium intensity of oocytes was decreased, these mice were subfertile and gave birth to significantly less pups during 6-month breeding period. QPCR demonstrated that Fbxo43 and P27kip, which are related to the release of MII oocyte arrest, and calcium channel partner protein Orai1 were downregulated, while Cdc2 and Ca2+ sensor at ER, stromal interaction molecule 1 (Stim1) were upregulated for a short time after adding FK506. Further exploration discovered that FK506 treatment increased Ca2+ concentration in the cytoplasm and caused pronucleus formation, however, the rate of parthenogenetic activation was lower compared to SrCl2 group. These findings identify the previously unknown role of FKBP12 in female reproduction which contributes to the release of calcium via IP3R channel and might open up new strategies for women who want to bear a baby after transplantation. FKBP12, known as FK506 binding protein, binds to immunosuppressive drug FK506, which must be taken by patients who received organ transplant. The side effect is that women have difficulty in bearing a baby at suitable bearing age, so it is important to find the reason of their subfertility. These findings identified the previously unknown roles of FKBP12, which contributes to the release of calcium via IP3R channel during the fertilization. Together, it may open up new strategies for women to have a baby after transplantation.
Store-Operated Calcium Entries Control Neural Stem Cell Self-Renewal in the Adult Brain Subventricular Zone
STEM CELLS
Authors: Domenichini, Florence; Terrie, Elodie; Arnault, Patricia; Harnois, Thomas; Magaud, Christophe; Bois, Patrick; Constantin, Bruno; Coronas, Valerie
Abstract
The subventricular zone (SVZ) is the major stem cell niche in the brain of adult mammals. Within this region, neural stem cells (NSC) proliferate, self-renew and give birth to neurons and glial cells. Previous studies underlined enrichment in calcium signaling-related transcripts in adult NSC. Because of their ability to mobilize sustained calcium influxes in response to a wide range of extracellular factors, store-operated channels (SOC) appear to be, among calcium channels, relevant candidates to induce calcium signaling in NSC whose cellular activities are continuously adapted to physiological signals from the microenvironment. By Reverse Transcription Polymerase Chain Reaction (RT-PCR), Western blotting and immunocytochemistry experiments, we demonstrate that SVZ cells express molecular actors known to build up SOC, namely transient receptor potential canonical 1 (TRPC1) and Orai1, as well as their activator stromal interaction molecule 1 (STIM1). Calcium imaging reveals that SVZ cells display store-operated calcium entries. Pharmacological blockade of SOC with SKF-96365 or YM-58483 (also called BTP2) decreases proliferation, impairs self-renewal by shifting the type of SVZ stem cell division from symmetric proliferative to asymmetric, thereby reducing the stem cell population. Brain section immunostainings show that TRPC1, Orai1, and STIM1 are expressed in vivo, in SOX2-positive SVZ NSC. Injection of SKF-96365 in brain lateral ventricle diminishes SVZ cell proliferation and reduces the ability of SVZ cells to form neurospheres in vitro. The present study combining in vitro and in vivo approaches uncovers a major role for SOC in the control of SVZ NSC population and opens new fields of investigation for stem cell biology in health and disease.