{'fraction_non_alphanumeric': 0.03613666228646518, 'fraction_numerical': 0.01445466491458607, 'mean_word_length': 5.019762845849803, 'pattern_counts': {'":': 0, '<': 1, '<?xml version=': 0, '>': 1, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
[Expressions of HIF-α and its target gene in monochorionic twin placentas with twin-twin transfusion syndrome].

OBJECTIVE
To determine hypoxia-inducible factor 1α (HIF-1α) and its target gene, vascular endothelial growth factor (VEGF) and receptor (VEGFR-1) concentrations in the placentas of the donor and recipient in monochorionic twin pregnancies with twin-twin transfusion syndrome (TTTS).


METHODS
Twenty monochorionic twin pregnancy cases were included in the study (10 with and 10 without TTTS). Tissue protein expressions of HIF-1α,VEGF and VEGFR-1 were determined by using immunohistochemistry. Western blot analysis were used to quantify and compare the protein expression. RT-PCR were used to compare their mRNA expressions.


RESULTS
HIF-1α was mainly observed in trophoblastic cells and villi capillaries endothelial cells, and VEGF in trophoblastic cells, endothelial cells and villi stromal cells; VEGFR-1 was mainly observed in villi trophoblastic cells and vascular endothelial cells. The placenta protein and mRNA expression of HIF-1α and its target gene in the donor placenta increased significantly (P<0.001) compared with that in the control placenta, but the expression of HIF-1α and its target gene in the recipients tended to be similar in the controls (P>0.05). There was no difference between the controls.


CONCLUSION
When the monochorionic twin placenta is formed in the early period, HIF-1α, VEGF and VEGFR-1 are over-expressed, which may affect the placenta angiogenesis and induce TTTS .