Turner syndrome patients with bicuspid aortic valves and renal malformations exhibit abnormal expression of X-linked inhibitor of apoptosis protein (XIAP)

AbstractWe analyzed mRNA expression of X-linked inhibitor of apoptosis protein (XIAP) in patients with Turner syndrome (TS) and examined its association with phenotypic features.XIAP mRNA expression levels were investigated in 98 patients with TS in total RNA extracted from blood leucocytes by real time quantitative polymerase chain reaction.Levels of XIAP mRNA were significantly lower in patients with bicuspid aortic valves (BAV; n=13) than those without (log XIAP –1.17±0.3 vs. –0.94±0.2, p=0.002). Significantly higher expression of XIAP mRNA was seen in patients with a mosaic karyotype and renal malformations (log XIAP –0.79±0.3 vs. –1.0±0.3, p=0.03). No correlations were seen between XIAP and other manifestations.Abnormal expression of XIAP may be an important underlying mechanism in the development of BAV and renal malformations in TS. However, abnormal XIAP mRNA expression, as determined from peripheral mononuclear cells, does not appear to explain all the somatic and visceral stigmata of TS.

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X-linked inhibitor of apoptosis protein and active caspase-3 expression patterns in antral follicles in the sheep ovary

Reproduction ◽

10.1530/rep-11-0177 ◽

2011 ◽

Vol 142 (6) ◽

pp. 855-867 ◽

Cited By ~ 7

Author(s):

Hollian R Phillipps ◽

Ilona C Kokay ◽

David R Grattan ◽

Peter R Hurst

Keyword(s):

Mrna Expression ◽

Caspase 3 ◽

Expression Patterns ◽

Inhibitor Of Apoptosis ◽

Mrna Levels ◽

Follicular Atresia ◽

Inhibitor Of Apoptosis Protein ◽

Antral Follicles ◽

Apoptosis Protein ◽

Active Caspase

X-linked inhibitor of apoptosis protein (XIAP) interacts with caspases to inhibit their activity, thereby providing a potential mechanism for regulation of granulosa cell apoptosis occurring during follicular atresia. The aim of this study was to determine the presence and localization of XIAP mRNA and protein content in the sheep ovary and compare these expression patterns with active caspase-3 protein in the same antral follicles. Romney ewe estrous cycles (n=25) were synchronized with 2–3 Estrumate injections and ovarian tissue collected during the luteal and follicular phases of the cycle. The presence ofXIAPmRNA was confirmed by RT-PCR using laser capture microdissected ovarian cell samples.XIAPmRNA was subsequently localized byin situhybridization histochemistry and XIAP and active caspase-3 protein visualized by immunohistochemistry. In antral follicles extensive XIAP localization was evident in both granulosa and thecal cells. In contrast, mRNA expression was widespread in granulosa cells and only detected in thecal tissue from a small proportion of antral follicles. Active caspase-3 and XIAP comparative expression analysis showed positiveXIAPmRNA expression in all late luteal phase (day 14) follicles, despite varying levels of active caspase-3 protein. A proportion of follicular phase (days 15 and 16) follicles, however, showed an inverse expression relationship at the protein and mRNA levels in both granulosa and thecal tissue, as did XIAP protein in day 14 follicles. These results suggest high XIAP may prevent activation of caspase-3, thereby regulating follicular atresia in antral follicles and could potentially be utilized as a marker of follicular health.

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