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Differential triiodothyronine responsiveness and transport by human cytotrophoblasts from normal and growth-restricted pregnancies.

Vasilopoulou E, Loubière LS, Martín-Santos A, McCabe CJ, Franklyn JA, Kilby MD, Chan SY - J. Clin. Endocrinol. Metab. (2010)

Bottom Line: Abnormal placentation in human pregnancy is associated with intrauterine fetal growth restriction (IUGR).The secretion of human chorionic gonadotropin was significantly increased by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), independently of T(3) treatment.IUGR cytotrophoblasts demonstrate altered responsiveness to T(3) with significant effects on cell survival and apoptosis compared with normal cytotrophoblasts.

View Article: PubMed Central - PubMed

Affiliation: School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

ABSTRACT

Context: Abnormal placentation in human pregnancy is associated with intrauterine fetal growth restriction (IUGR). Our group has previously reported the association between severe IUGR, lower fetal circulating concentrations of thyroid hormones (THs), and altered expression of TH receptors and TH transporters within human placental villi. We postulate that altered TH bioavailability to trophoblasts may contribute to the pathogenesis of IUGR.

Design and objective: Cytotrophoblasts were isolated from normal and IUGR human placentae to compare their responsiveness to T(3) and their capability for T(3) transport.

Results: Compared with normal cytotrophoblasts, the viability of IUGR cytotrophoblasts (assessed by methyltetrazoleum assay) was significantly reduced (P < 0.001), whereas apoptosis (assessed using caspase 3/7 activity and M30 immunoreactivity) was significantly increased after T(3) treatment for 48 h (P < 0.001 and P < 0.01, respectively). The secretion of human chorionic gonadotropin was significantly increased by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), independently of T(3) treatment. Net transport of [(125)I]T(3) was 20% higher by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), and this was accompanied by a 2-fold increase in the protein expression of the TH transporter, monocarboxylate transporter 8, as assessed by Western immunoblotting (P < 0.01).

Conclusions: IUGR cytotrophoblasts demonstrate altered responsiveness to T(3) with significant effects on cell survival and apoptosis compared with normal cytotrophoblasts. Increased monocarboxylate transporter 8 expression and intracellular T(3) accumulation may contribute to the altered T(3) responsiveness of IUGR cytotrophoblasts.

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Effect of T3 on the survival and apoptosis of normal and IUGR cytotrophoblasts. Survival and apoptosis were assessed after 48 h of treatment with 0, 1, 10, or 100 nm T3. Within each experiment, results were compared with that after no T3 treatment (0 nm), which was given an arbitrary value of 100%. A, Cytotrophoblast survival assessed using the MTT assay (normal, n = 9; IUGR, n = 5). B, Apoptosis assessed using the caspase 3/7 activity assay (normal, n = 9; IUGR, n = 5). C, Apoptosis assessed by immunofluorescent staining for M30 (normal, n = 4; IUGR, n = 3). **, P < 0.01; ***, P < 0.001.
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Figure 2: Effect of T3 on the survival and apoptosis of normal and IUGR cytotrophoblasts. Survival and apoptosis were assessed after 48 h of treatment with 0, 1, 10, or 100 nm T3. Within each experiment, results were compared with that after no T3 treatment (0 nm), which was given an arbitrary value of 100%. A, Cytotrophoblast survival assessed using the MTT assay (normal, n = 9; IUGR, n = 5). B, Apoptosis assessed using the caspase 3/7 activity assay (normal, n = 9; IUGR, n = 5). C, Apoptosis assessed by immunofluorescent staining for M30 (normal, n = 4; IUGR, n = 3). **, P < 0.01; ***, P < 0.001.

Mentions: Because cytotrophoblasts do not proliferate in vitro, the MTT assay was used as a measure of cell survival. Overall, IUGR cytotrophoblasts survived less compared with normal cytotrophoblasts in response to T3 treatment (Fig. 2A; P < 0.001). Post hoc analysis revealed that this difference was significant when the cells were treated with 1 nm T3 (20% reduction; P < 0.01). There was no difference in the survival of normal and IUGR cytotrophoblasts in the absence of T3 (data not shown).


Differential triiodothyronine responsiveness and transport by human cytotrophoblasts from normal and growth-restricted pregnancies.

Vasilopoulou E, Loubière LS, Martín-Santos A, McCabe CJ, Franklyn JA, Kilby MD, Chan SY - J. Clin. Endocrinol. Metab. (2010)

Effect of T3 on the survival and apoptosis of normal and IUGR cytotrophoblasts. Survival and apoptosis were assessed after 48 h of treatment with 0, 1, 10, or 100 nm T3. Within each experiment, results were compared with that after no T3 treatment (0 nm), which was given an arbitrary value of 100%. A, Cytotrophoblast survival assessed using the MTT assay (normal, n = 9; IUGR, n = 5). B, Apoptosis assessed using the caspase 3/7 activity assay (normal, n = 9; IUGR, n = 5). C, Apoptosis assessed by immunofluorescent staining for M30 (normal, n = 4; IUGR, n = 3). **, P < 0.01; ***, P < 0.001.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3050105&req=5

Figure 2: Effect of T3 on the survival and apoptosis of normal and IUGR cytotrophoblasts. Survival and apoptosis were assessed after 48 h of treatment with 0, 1, 10, or 100 nm T3. Within each experiment, results were compared with that after no T3 treatment (0 nm), which was given an arbitrary value of 100%. A, Cytotrophoblast survival assessed using the MTT assay (normal, n = 9; IUGR, n = 5). B, Apoptosis assessed using the caspase 3/7 activity assay (normal, n = 9; IUGR, n = 5). C, Apoptosis assessed by immunofluorescent staining for M30 (normal, n = 4; IUGR, n = 3). **, P < 0.01; ***, P < 0.001.
Mentions: Because cytotrophoblasts do not proliferate in vitro, the MTT assay was used as a measure of cell survival. Overall, IUGR cytotrophoblasts survived less compared with normal cytotrophoblasts in response to T3 treatment (Fig. 2A; P < 0.001). Post hoc analysis revealed that this difference was significant when the cells were treated with 1 nm T3 (20% reduction; P < 0.01). There was no difference in the survival of normal and IUGR cytotrophoblasts in the absence of T3 (data not shown).

Bottom Line: Abnormal placentation in human pregnancy is associated with intrauterine fetal growth restriction (IUGR).The secretion of human chorionic gonadotropin was significantly increased by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), independently of T(3) treatment.IUGR cytotrophoblasts demonstrate altered responsiveness to T(3) with significant effects on cell survival and apoptosis compared with normal cytotrophoblasts.

View Article: PubMed Central - PubMed

Affiliation: School of Clinical and Experimental Medicine, College of Medical and Dental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom.

ABSTRACT

Context: Abnormal placentation in human pregnancy is associated with intrauterine fetal growth restriction (IUGR). Our group has previously reported the association between severe IUGR, lower fetal circulating concentrations of thyroid hormones (THs), and altered expression of TH receptors and TH transporters within human placental villi. We postulate that altered TH bioavailability to trophoblasts may contribute to the pathogenesis of IUGR.

Design and objective: Cytotrophoblasts were isolated from normal and IUGR human placentae to compare their responsiveness to T(3) and their capability for T(3) transport.

Results: Compared with normal cytotrophoblasts, the viability of IUGR cytotrophoblasts (assessed by methyltetrazoleum assay) was significantly reduced (P < 0.001), whereas apoptosis (assessed using caspase 3/7 activity and M30 immunoreactivity) was significantly increased after T(3) treatment for 48 h (P < 0.001 and P < 0.01, respectively). The secretion of human chorionic gonadotropin was significantly increased by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), independently of T(3) treatment. Net transport of [(125)I]T(3) was 20% higher by IUGR cytotrophoblasts compared with normal cytotrophoblasts (P < 0.001), and this was accompanied by a 2-fold increase in the protein expression of the TH transporter, monocarboxylate transporter 8, as assessed by Western immunoblotting (P < 0.01).

Conclusions: IUGR cytotrophoblasts demonstrate altered responsiveness to T(3) with significant effects on cell survival and apoptosis compared with normal cytotrophoblasts. Increased monocarboxylate transporter 8 expression and intracellular T(3) accumulation may contribute to the altered T(3) responsiveness of IUGR cytotrophoblasts.

Show MeSH
Related in: MedlinePlus