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10 results on '"Capatina, Nadejda"'

1. Role of endoplasmic reticulum stress in trophoblast stem cell differentiation

Author

Capatina, Nadejda and Burton, Graham

Subjects
612.6, endoplasmic reticulum stress, trophoblast, stem cell differentiation
Abstract

The project aimed to provide a mechanistic understanding of the effect of endoplasmic reticulum (ER) stress on the differentiation of trophoblast stem cells (TSCs), placental development, and subsequent pregnancy outcome. To address this question, I first used an in vitro mouse TSC model. Morphological observations suggest that upon ER stress, TSCs lose stemness by differentiating into specialized trophoblast cell subtypes. Second, I used an in vivo Eif2s1tm1RjK mouse model that exhibits chronic ER stress. Third, I induced ER stress using a more physiological stress inducer in pre-implantation wild-type embryos for 48h in vitro, which results in a significantly smaller TE stem cell pool, and increased expression of Grp78, Atf4 and Atf6a UPR markers. The phenotype was partially rescued by addition of a chaperone to the culture medium. In conclusion, both the in vitro and in vivo models demonstrate that ER stress perturbs differentiation of TS cells at the blastocyst stage, with consequences for placental morphogenesis and fetal development. Pilot studies using a stress-relieving chaperone indicate that therapeutic interventions may be possible.

Published
2019
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2. Meta-analyses in cholestatic pregnancy: The outstanding clinical questions.

Author

Capatina, Nadejda and Ovadia, Caroline

Subjects
*PREMATURE infants, *BILE acids, *DISEASE management, *META-analysis, *PERINATAL death, *SEVERITY of illness index, *PREGNANCY complications, *CHOLESTASIS
Abstract

Reports of adverse pregnancy outcomes associated with maternal pruritus and liver impairment have circulated since the 1800s, yet the precise diagnosis and management of intrahepatic cholestasis of pregnancy have varied markedly. Recent evidence, including that from individual participant data meta-analyses, has provided an evidence that brings us closer to standardised, and optimal, management of the condition. Based upon increased adverse perinatal outcomes with higher bile acid concentrations, disease management should be according to severity (defined by peak bile acid concentration) in order to recommend appropriate gestation of birth. Similarly, the reduced spontaneous preterm birth rate for patients receiving ursodeoxycholic acid treatment suggests potential benefit for the treatment of patients with moderate-severe disease. [ABSTRACT FROM AUTHOR]

Published
2024
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4. Elevated homocysteine activates unfolded protein responses and causes aberrant trophoblast differentiation and mouse blastocyst development

Author

Capatina, Nadejda, Burton, Graham J, Yung, Hong Wa, Yung, Hong Wa [0000-0002-0869-7426], and Apollo - University of Cambridge Repository

Subjects
placenta, Physiology, Vitamins, unfolded protein response, Trophoblasts, Mice, Blastocyst, Folic Acid, Physiology (medical), endoplasmic reticulum stress, Animals, Humans, Female, pregnancy, trophoblast stem cells, ORIGINAL ARTICLES, hyperhomocysteinemia, Homocysteine, ORIGINAL ARTICLE
Abstract

Funder: Centre for Trophoblast Research PhD studentship, Hyperhomocysteinemia may arise from folate/vitamin B12 deficiency, genetic polymorphisms, kidney disease, or hypothyroidism. It is associated with an increased risk of early pregnancy loss and placenta-related complications of pregnancy, including pre-eclampsia and fetal growth restriction. While the majority of studies of hyperhomocysteinemia focus on epigenetic changes secondary to metabolic disruption, the effects of homocysteine toxicity on placental development remain unexplored. Here, we investigated the influence of hyperhomocysteinemia on early blastocyst development and trophoblast differentiation. Exposure of cultured blastocysts to high homocysteine levels reduces cell number in the trophectoderm layer, most likely through increased apoptosis. Homocysteine also promotes differentiation of a trophoblast stem cell line. Both effects diminish the stem cell pool, and are mediated in an endoplasmic reticulum (ER) unfolded protein response (UPRER )-dependent manner. Targeted alleviation of UPRER may therefore provide a new therapeutic intervention to improve pregnancy outcome in women with hyperhomocysteinemia.

Published
2022
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6. Excessive endoplasmic reticulum stress drives aberrant mouse trophoblast differentiation and placental development leading to pregnancy loss

Author

Capatina, Nadejda, Hemberger, Myriam, Burton, Graham J, Watson, Erica D, Yung, Hong Wa, Burton, Graham J [0000-0001-8677-4143], Watson, Erica D [0000-0003-4496-2271], Yung, Hong Wa [0000-0002-0869-7426], and Apollo - University of Cambridge Repository

Subjects
trophoblast differentiation, pregnancy complications, Placenta, placental development, Cell Differentiation, Endoplasmic Reticulum Stress, Placentation, Trophoblasts, Abortion, Spontaneous, Mice, Pregnancy, embryonic structures, Animals, Humans, Female, reproductive and urinary physiology
Abstract

KEY POINTS: Endoplasmic reticulum (ER) stress promotes placental dysmorphogenesis and is associated with poor pregnancy outcomes. We show that unfolded protein response signalling pathways located in the ER drive differentiation of mouse trophoblast stem cells into trophoblast subtypes involved in development of the placental labyrinth zone and trophoblast invasion. In a mouse model of chronic ER stress (Eif2s1tm1RjK ), higher ER stress in homozygous blastocysts is accompanied by reduced trophectoderm cell number and developmental delay and also is associated with an increased incidence of early pregnancy loss. Administration of the chemical chaperone, tauroursodeoxycholic acid, to Eif2s1+/tm1RjK heterozygous females during pregnancy alleviated ER stress in the mutant placenta, restored normal trophoblast populations and reduced the frequency of early pregnancy loss. Our results suggest that alleviation of intrauterine ER stress could provide a potential therapeutic target to improve pregnancy outcome in women with pre-gestational metabolic or gynaecological conditions. ABSTRACT: Women with pre-gestational health conditions (e.g. obesity, diabetes) or gynaecological problems (e.g. endometriosis) are at increased risk of adverse pregnancy outcomes including miscarriage, pre-eclampsia and fetal growth restriction. Increasing evidence suggests that unfavourable intrauterine conditions leading to poor implantation and/or defective placentation are a possible causative factor. The endoplasmic reticulum (ER) unfolded protein response (UPRER ) signalling pathways are a convergence point of various physiological stress stimuli that can be triggered by an unfavourable intrauterine environment. Therefore, we explored the impact of ER stress on mouse trophoblast differentiation in vitro, mouse blastocyst formation and early placenta development in the Eif2s1tm1RjK mutant mouse model of chronic ER stress. Chemically-manipulated ER stress or activation of UPRER pathways in a mouse trophoblast stem cell line promoted lineage-specific differentiation. Co-treatment with specific UPRER pathway inhibitors rescued this effect. Although the inner cell mass was unaffected, the trophectoderm of homozygous Eif2s1tm1RjK blastocysts exhibited ER stress associated with a reduced cell number. Furthermore, one-third of Eif2s1tm1RjK homozygous blastocysts exhibited severe developmental defects. We have previously reported a reduced trophoblast population and premature trophoblast differentiation in Eif2s1tm1RjK homozygous placentas at mid-gestation. Here, we demonstrate that treatment of Eif2s1+/tm1RjK heterozygous pregnant females with the chemical chaperone tauroursodeoxycholic acid alleviated ER stress, restored the trophoblast population and reduced the frequency of embryonic lethality. Our data suggest that therapeutic targeting of ER stress may improve pregnancy outcome in women with pre-gestational metabolic or gynaecological conditions.

Published
2021
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8. Abnormal creatine transport of mutations in monocarboxylate transporter 12 (MCT12) found in patients with age-related cataract can be partially rescued by exogenous chaperone CD147

Author

Stäubli, Andrina, Capatina, Nadejda, Fuhrer, Yvonne, Munier, Francis L., Labs, Stephan, Schorderet, Daniel F., Tiwari, Amit, Verrey, Francois, Heon, Elise, Cheng, Ching-Yu, Wong, Tien-Yin, Berger, Wolfgang, Camargo, Simone M R., Kloeckener-Gruissem, Barbara, Stäubli, Andrina, Capatina, Nadejda, Fuhrer, Yvonne, Munier, Francis L., Labs, Stephan, Schorderet, Daniel F., Tiwari, Amit, Verrey, Francois, Heon, Elise, Cheng, Ching-Yu, Wong, Tien-Yin, Berger, Wolfgang, Camargo, Simone M R., and Kloeckener-Gruissem, Barbara

Abstract

Membrane transporters influence biological functions in the ocular lens. Here, we investigate the monocarboxylate transporter 12 (MCT12), also called creatine transporter 2 (CRT2), which is found in the ocular lens and is involved in cataract. As the age-related form affects about half of the population world-wide, understanding relevant pathomechanisms is a prerequisite for exploring non-invasive treatments. We screened the coding exons of the gene SLC16A12 in 877 patients from five cohorts, including Caucasian and Asian ethnicities. A previously identified risk factor, SNP rs3740030, displayed different frequencies in the Asian cohorts but risk could not be established. In 15 patients 13 very rare heterozygous nucleotide substitutions were identified, of which eight led to non-synonymous and four to synonymous amino acid exchanges and one mapped to the canonical splice site in intron 3. Their impact on creatine transport was tested in Xenopus laevis oocytes and human HEK293T cells. Four variants (p.Ser158Pro, p.Gly205Val, p.Pro395Gln and p.Ser453Arg) displayed severe reduction in both model systems, indicating conserved function. Two of these, p.Gly205Val, and p.Ser453Arg, did not localize to the oocyte membrane, suggesting possible impacts on protein interactions for transporter processing. In support, exogenously supplied excess of MCT12's chaperone CD147 in HEK293T cells led to a partial recovery of the defective uptake activity from p.Gly205Val and also from mutant p.Pro395Gln, which did localize to the membrane. Our findings provide first insight in the molecular requirements of creatine transporter, with particular emphasis on rescuing effects by its chaperone CD147, which can provide useful pharmacological information for substrate delivery.

Published
2021

10. Abnormal creatine transport of mutations in monocarboxylate transporter 12 (MCT12) found in patients with age-related cataract can be partially rescued by exogenous chaperone CD147

Author

Stäubli, Andrina, Capatina, Nadejda, Fuhrer, Yvonne, Munier, Francis L., Labs, Stephan, Schorderet, Daniel F., Tiwari, Amit, Verrey, Francois, Heon, Elise, Cheng, Ching-Yu, Wong, Tien-Yin, Berger, Wolfgang, Camargo, Simone M R., Kloeckener-Gruissem, Barbara, Stäubli, Andrina, Capatina, Nadejda, Fuhrer, Yvonne, Munier, Francis L., Labs, Stephan, Schorderet, Daniel F., Tiwari, Amit, Verrey, Francois, Heon, Elise, Cheng, Ching-Yu, Wong, Tien-Yin, Berger, Wolfgang, Camargo, Simone M R., and Kloeckener-Gruissem, Barbara

Abstract

Membrane transporters influence biological functions in the ocular lens. Here, we investigate the monocarboxylate transporter 12 (MCT12), also called creatine transporter 2 (CRT2), which is found in the ocular lens and is involved in cataract. As the age-related form affects about half of the population world-wide, understanding relevant pathomechanisms is a prerequisite for exploring non-invasive treatments. We screened the coding exons of the gene SLC16A12 in 877 patients from five cohorts, including Caucasian and Asian ethnicities. A previously identified risk factor, SNP rs3740030, displayed different frequencies in the Asian cohorts but risk could not be established. In 15 patients 13 very rare heterozygous nucleotide substitutions were identified, of which eight led to non-synonymous and four to synonymous amino acid exchanges and one mapped to the canonical splice site in intron 3. Their impact on creatine transport was tested in Xenopus laevis oocytes and human HEK293T cells. Four variants (p.Ser158Pro, p.Gly205Val, p.Pro395Gln and p.Ser453Arg) displayed severe reduction in both model systems, indicating conserved function. Two of these, p.Gly205Val, and p.Ser453Arg, did not localize to the oocyte membrane, suggesting possible impacts on protein interactions for transporter processing. In support, exogenously supplied excess of MCT12's chaperone CD147 in HEK293T cells led to a partial recovery of the defective uptake activity from p.Gly205Val and also from mutant p.Pro395Gln, which did localize to the membrane. Our findings provide first insight in the molecular requirements of creatine transporter, with particular emphasis on rescuing effects by its chaperone CD147, which can provide useful pharmacological information for substrate delivery.

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