Synergistic Promoting Effects of X-Linked Inhibitor of Apoptosis Protein and Matrix on the In Vitro Follicular Maturation of Marmoset Follicles

Author(s):  
Yoon Young Kim ◽  
Jun-Won Yun ◽  
Sung Woo Kim ◽  
Hoon Kim ◽  
Byeong-Cheol Kang ◽  
...  
2015 ◽  
Vol 308 (2) ◽  
pp. G92-G99 ◽  
Author(s):  
Jakob Benedict Seidelin ◽  
Sylvester Larsen ◽  
Dorte Linnemann ◽  
Ben Vainer ◽  
Mehmet Coskun ◽  
...  

Identification of pathways involved in wound healing is important for understanding the pathogenesis of various intestinal diseases. Cellular inhibitor of apoptosis protein 2 (cIAP2) regulates proliferation and migration in nonepithelial cells and is expressed in human colonocytes. The aim of the study was to investigate the role of cIAP2 for wound healing in the normal human colon. Wound tissue was generated by taking rectosigmoidal biopsies across an experimental ulcer in healthy subjects after 5, 24, and 48 h. In experimental ulcers, the expression of cIAP2 in regenerating intestinal epithelial cells (IECs) was increased at the wound edge after 24 h ( P < 0.05), returned to normal after reepithelialization, and correlated with the inflammatory reaction in the experimental wounds ( P < 0.001). cIAP2 was induced in vitro in regenerating Caco2 IECs after wound infliction ( P < 0.01). Knockdown of cIAP2 caused a substantial impairment of the IEC regeneration through inhibition of migration ( P < 0.005). cIAP2 overexpression lead to formation of migrating IECs and upregulation of expression of RhoA and Rac1 as well as GTP-activation of Rac1. Transforming growth factor-β1 enhanced the expression of cIAP2 but was not upregulated in wounds in vivo and in vitro. NF-κB and MAPK pathways did not affect cIAP2 expression. cIAP2 is in conclusion a regulator of human intestinal wound healing through enhanced migration along with activation of Rac1, and the findings suggest that cIAP2 could be a future therapeutic target to improve intestinal wound healing.


Blood ◽  
1999 ◽  
Vol 93 (10) ◽  
pp. 3418-3431 ◽  
Author(s):  
Anton J.G. Horrevoets ◽  
Ruud D. Fontijn ◽  
Anton Jan van Zonneveld ◽  
Carlie J.M. de Vries ◽  
Jan Wouter ten Cate ◽  
...  

Activation and dysfunction of endothelial cells play a prominent role in patho-physiological processes such as atherosclerosis. We describe the identification by differential display of 106 cytokine-responsive gene fragments from endothelial cells, activated by monocyte conditioned medium or tumor necrosis factor-. A minority of the fragments (22/106) represent known genes involved in various processes, including leukocyte trafficking, vesicular transport, cell cycle control, apoptosis, and cellular protection against oxidative stress. Full-length cDNA clones were obtained for five novel transcripts that were induced or repressed more than 10-fold in vitro. These novel human cDNAs CA2_1, CG12_1, GG10_2, AG8_1, and GG2_1 encode inhibitor of apoptosis protein-1 (hIAP-1), homologues of apolipoprotein-L, mouse rabkinesin-6, rat stannin, and a novel 188 amino acid protein, respectively. Expression of 4 novel transcripts is shown by in situ hybridization on healthy and atherosclerotic vascular tissue, using monocyte chemotactic protein-1 as a marker for inflammation. CA2_1 (hIAP-1) and AG8_1 are expressed by endothelial cells and macrophage foam cells of the inflamed vascular wall. CG12_1 (apolipoprotein-L like) was specifically expressed in endothelial cells lining the normal and atherosclerotic iliac artery and aorta. These results substantiate the complex change in the gene expression pattern of vascular endothelial cells, which accompanies the inflammatory reaction of atherosclerotic lesions.


2001 ◽  
Vol 21 (13) ◽  
pp. 4292-4301 ◽  
Author(s):  
Bettina W. M. Richter ◽  
Samy S. Mir ◽  
Lisa J. Eiben ◽  
Jennifer Lewis ◽  
Stephanie Birkey Reffey ◽  
...  

ABSTRACT Inhibitor of apoptosis protein (IAP)-like protein-1 (ILP-1) (also known as X-linked IAP [XIAP] and mammalian IAP homolog A [MIHA]) is a potent inhibitor of apoptosis and exerts its effects, at least in part, by the direct association with and inhibition of specific caspases. Here, we describe the molecular cloning and characterization of a human gene related to ILP-1, termed ILP-2. Despite high homology to ILP-1, ILP-2 is encoded by a distinct gene, which in normal tissues is expressed solely in testis. In contrast to ILP-1, overexpression of ILP-2 had no protective effect on apoptosis mediated by Fas (also known as CD95) or tumor necrosis factor. However, ILP-2 potently inhibited apoptosis induced by overexpression of Bax or by coexpression of caspase 9 with Apaf-1, and preincubation of cytosolic extracts with ILP-2 abrogated caspase activation in vitro. A processed form of caspase 9 could be coprecipitated with ILP-2 from cells, suggesting a physical interaction between ILP-2 and caspase 9. Thus, ILP-2 is a novel IAP family member with restricted specificity for caspase 9.


2003 ◽  
Vol 199 (1) ◽  
pp. 69-80 ◽  
Author(s):  
Zheng Xing ◽  
Edward M. Conway ◽  
Chulho Kang ◽  
Astar Winoto

Survivin is an inhibitor of apoptosis protein that also functions during mitosis. It is expressed in all common tumors and tissues with proliferating cells, including thymus. To examine its role in apoptosis and proliferation, we generated two T cell–specific survivin-deficient mouse lines with deletion occurring at different developmental stages. Analysis of early deleting survivin mice showed arrest at the pre–T cell receptor proliferating checkpoint. Loss of survivin at a later stage resulted in normal thymic development, but peripheral T cells were immature and significantly reduced in number. In contrast to in vitro studies, loss of survivin does not lead to increased apoptosis. However, newborn thymocyte homeostatic and mitogen-induced proliferation of survivin-deficient T cells were greatly impaired. These data suggest that survivin is not essential for T cell apoptosis but is crucial for T cell maturation and proliferation, and survivin-mediated homeostatic expansion is an important physiological process of T cell development.


Reproduction ◽  
2012 ◽  
Vol 144 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Hollian R Phillipps ◽  
Peter R Hurst

X-linked inhibitor of apoptosis protein (XIAP), a member of the inhibitor of apoptosis protein family, is involved in regulating a number of functions including receptor-mediated intracellular signalling and early development. Its role as an endogenous caspase inhibitor, however, is the most highly characterised. Consequently, this protein has been implicated as an anti-apoptotic factor in the ovary.In vitroandin vivostudies have begun dissecting the stimuli and signalling networks that lead to XIAP upregulation in granulosa cells. The objective of this review is to briefly summarise the current knowledge concerning XIAP and its interactions with different caspases. Furthermore, XIAP's emerging role in the mammalian ovary will be explored and comparison is made with its functions in the mammary gland. Finally, the idea that XIAP may act as a molecular signalling switch in granulosa cells following detachment from underlying layers to promote follicular atresia will be introduced.


2016 ◽  
Vol 7 (8) ◽  
pp. e2325-e2325 ◽  
Author(s):  
A Tchoghandjian ◽  
A Soubéran ◽  
E Tabouret ◽  
C Colin ◽  
E Denicolaï ◽  
...  

2001 ◽  
Vol 153 (1) ◽  
pp. 221-228 ◽  
Author(s):  
Darren L. Roberts ◽  
Wendy Merrison ◽  
Marion MacFarlane ◽  
Gerald M. Cohen

Smac/DIABLO, a recently identified inhibitor of apoptosis protein (IAP)-binding protein, is released from the mitochondria during apoptosis and reportedly potentiates apoptosis by relieving the inhibition of IAPs on caspases. We now describe the molecular characterization of Smac β, an alternatively spliced form of Smac, which lacks the mitochondrial-targeting sequence found in Smac and has a cortical distribution in both human embryonic kidney 293 and breast epithelial tumor MCF-7 cells. Smac β, which binds IAPs in vitro, does not bind IAPs in intact cells due to cellular processing and removal of its NH2-terminal IAP-binding domain. Despite its inability to interact with IAPs in cells, processed Smac β is proapoptotic, as demonstrated by its ability to potentiate apoptosis induced by both death receptor and chemical stimuli. Furthermore, expression of a NH2-terminally truncated Smac mutant (Δ75), which lacks the entire IAP-interacting domain, potentiates apoptosis to the same extent as Smac and Smac β. Our data support the hypothesis that the main proapoptotic function of Smac and Smac β is due to a mechanism other than IAP binding.


Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1842-1842
Author(s):  
Ihab Abd-Elrahman ◽  
Varda Deutsch ◽  
Klilah Hershko ◽  
Tsahi Noyman ◽  
Itay Lazar ◽  
...  

Abstract The exact mechanism of platelet production is poorly understood. A relationship between activation of the apoptotic cell machinery and the formation of pro-platelets has been established. In this study we show that Livin plays a major role in this process. Livin is a member of the Inhibitor of Apoptosis Protein (IAP) family, a novel family of intracellular anti-apoptotic proteins that act by binding and inhibiting caspases. We found that Livin mRNA and protein are expressed in platelets and Livin was also clearly detected by immunohistochemistry staining in normal mature bone marrow megakaryocytes (MK). Overexpression of Livin was also demonstrated in MK of patients with various hematological diseases such as ITP, MDS, Hodgkin’s disease, ET and PV. An in vitro model was established to evaluate the potential role of Livin in thrombopoiesis. The human erythroleukemic cell line, LAMA-84, was induced by a phorbol ester (PMA) to differentiate to MK. Differentiation was characterized by upregulation of the MK marker CD41 from 6% to &gt;60% and downregulation of the erythroid cell marker CD71 from 97% to 70%. Increased cell size, ploidy, and DNA synthesis, all markers of MK differentiation, were detected by flow cytometry. Upon differentiation induced by PMA, LAMA-84 cells formed pro-platelets and produced functional platelets capable of aggregation. This thrombopoiesis was accompanied by Livin overexpression. Moreover, overexpression of Livin by transfection decreased the percentage of the undifferentiated CD71+ cells to 53 % compared to 73 % in control cells (p= 0.007) and increased the production of platelets by two folds compared to control cells. Overexpression of Livin reduced caspase 3 activity and inhibited MK apoptosis. Our results show that anti-apoptotic Livin plays a role in thrombopoiesis possibly by protecting the maturing MK from apoptosis, thus affording more time for efficient platelet production by longer living pro-platelets. We are currently using this new cell line model to further characterize the molecular relationship between apoptosis and thrombopoiesis.


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