Expression of proteins related to thyroid hormone function in the uterus is down-regulated at the day of implantation in hypothyroid pregnant rats

Thyroid transcriptomic profiling reveals the differential regulation of lncRNA and mRNA related to prolificacy in Small Tail Han sheep with FecB++ genotype

The thyroid gland is an important endocrine gland in animals, which mainly secretes thyroid hormones and acts on various organs of the body. Long-chain non-coding RNA (lncRNA) plays an important role in animal reproduction. However, there is still a lack of understanding of their expression patterns and potential roles in the thyroid of Small Tail Han (STH) sheep. In this study, RNA-seq was used to examine the transcriptome expression patterns of lncRNAs and mRNAs in the follicular phase (ww_FT) and luteal phase (ww_LT) in FecB++ genotype STH Sheep. A total of 17,217 lncRNAs and 39,112 mRNAs were identified including 96 differentially expressed lncRNAs (DELs) and 1054 differentially expressed mRNAs (DEGs). Functional analysis of genes with significant differences in expression level showed that these genes could be enriched in Ras signalling pathway, hedgehog (HH) signalling pathway, ATP-binding cassette (ABC) transporters and other signalling pathways related to animal reproduction. In addition, through correlation analysis for lncRNA-mRNA co-expression and network construction, we found that LNC_009115 and LNC_005796 trans target NIK-related kinase (NRK) and poly(A)-specific ribonuclease (PARN). LNC_007189 and LNC_002045 trans target progesterone-induced blocking factor 1 (PIBF1), LNC_009013 trans targets small mothers against decapentaplegic (SMAD1) are related to animal reproduction. These genes add new resources for elucidating the regulatory mechanisms of reproduction in sheep with different reproductive cycles of the FecB++ genotype STH sheep.

Uterine deficiency of Dnmt3b impairs decidualization and causes consequent embryo implantation defects

Uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects. Recent advances in molecular technologies have allowed the unprecedented mapping of epigenetic modifications during embryo implantation. DNA methyltransferase 3a (DNMT3A) and DNMT3B are responsible for establishing DNA methylation patterns produced through their de novo-type DNA methylation activity in implantation stage embryos and during germ cell differentiation. It was reported that conditional knockout of Dnmt3a in the uterus does not markedly affect endometrial function during embryo implantation, but the tissue-specific functions of Dnmt3b in the endometrium during embryo implantation remain poorly understood to investigate the role of Dnmt3b during peri-implantation period. Here, we generated Dnmt3b conditional knockout (Dnmt3bd/d) female mice using progesterone receptor-Cre mice and examined the role of Dnmt3b during embryo implantation. Dnmt3bd/d female mice exhibited compromised fertility, which was associated with defective decidualization, but not endometrial receptivity. Furthermore, results showed loss of Dnmt3b did not lead to altered genomic methylation patterns of the decidual endometrium during early pregnancy. Transcriptome sequencing analysis of uteri from day 6 pregnant mice identified phosphoglycerate kinase 1 (Pgk1) as one of the most variable genes in Dnmt3bd/d decidual endometrium. Potential roles of PGK1 in the decidualization process during early pregnancy were confirmed. Lastly, the compromised decidualization upon the downregulation of Dnmt3b could be reversed by overexpression of Pgk1. Collectively, our findings indicate that uterine deficiency of Dnmt3b impairs decidualization and consequent embryo implantation defects.

Research progress on the impact of anxiety and depression on embryo transfer outcomes of in vitro fertilization

Infertile women who receive in vitro fertilization-embryo transfer (IVF-ET) often present psychological distress such as anxiety, depression and perceived stress. This adverse psychological state can affect the immune homeostasis at the mother-fetus interface, the incubation of blastula and the receptivity of the maternal endometrium through the psycho-neuro-immuno-endocrine network, which in turns affect the proliferation, invasion and vascular remodeling of the embryo trophoblast, and reduces the success rate of embryo transfer. This adverse outcome of embryo transfer will further aggravate the psychological pain of patients, forming a vicious circle. The positive partner effect between husband and wife or the use of cognitive behavioral therapy, acupuncture, yoga and other measures for psychological intervention before and after IVF-ET, may break the vicious cycle and improve clinical pregnancy rate, continuous pregnancy rate and live birth rate after IVF-ET by alleviating anxiety and depression. This article reviews the research progress on anxiety and depression states in women receiving IVF-ET and the impact on outcome of IVF-ET and related mechanisms, as well as the application of psychological intervention for alleviating anxiety and depression, so as to provide insights in improving the outcome of IVF-ET.

IVF/ICSI outcomes of euthyroid infertile women with thyroid autoimmunity: does treatment with aspirin plus prednisone matter?

Background

Thyroid autoimmunity (TAI) has been demonstrated to be associated with adverse pregnancy including recurrent miscarriage, unexplained infertility, and implantation failure. To settle with the fertility problem, prescribing aspirin combined with prednisone (P + A) to women positive for anti-thyroid antibodies is frequent in clinical practice, but the underlying effect remains controversial.

Methods

A multicenter, retrospective study was conducted in three reproductive centers from 2017 to 2020. A total of 494 euthyroid infertile women were recruited who were positive for anti-thyroperoxidase and/or thyroglobulin antibodies (TPOAb and TgAb, respectively) with thyroid-stimulating hormone (TSH) levels ranging 0.35-4.0mIU/L and underwent their first in vitro fertilization and embryo transfer (IVF-ET) cycle. Ultimately, 346 women were included of which 150 women were treated with prednisone (10 mg/d) and aspirin (100 mg/d). The remaining 196 women were untreated (control group). Treatment started on the day of embryo transfer and continued until clinical pregnancy was determined.

Results

The clinical pregnancy rate was 57.5% vs. 63.5% in the control and treated groups (P = 0.414) for first fresh embryo transfer cycles and 57.8% vs. 61.8% for frozen-thawed embryo transfer cycles (P = 0.606). In addition, the live birth rate for the fresh embryo transfer was 49.6% vs. 47.3% in the control and treated groups (P = 0.762). Logistic regression revealed that aspirin plus prednisone did not improve the clinical pregnancy rate or miscarriage rate. Furthermore, it was observed that low free triiodothyronine (FT3) was associated with high miscarriage rates.

Conclusions

Utilizing an adjuvant treatment of P + A after the embryo transfer may not be necessary in euthyroid women with thyroid autoimmunity undergoing their first IVF-ET, regardless of the embryo type (fresh or frozen).

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04532-2.

Age-related functional changes of total thyroid hormones and glycosaminoglycans in growing calves

Background and Aim:

During the physiological growing, thyroid and proteoglycan glycosaminoglycan (GAG) changes dynamically occur, according to genetic and non-genetic factors. The purpose of this research was to compare the effects of early postnatal development (10 days) until 210 days of life on the triiodothyronine (T₃), thyroxine (T₄), the relative T₄:T₃ ratio, and GAGs profile, and to define the different reference intervals of the calf’s development through the various growing phases.

Materials and Methods:

The effect of growing on total thyroid hormones and GAG profiles was studied from 10 days to 210days of age in 64 clinically healthy Brown calves, 30males and 34females. Blood samples were collected at 10, 20, 30, 60, 90, 120, 150, 180, and 210days of age.

Results:

The results showed a significant effect of a calf’s growth on T₃, T₄, and GAG values (p<0.0001). Significant correlations between T₃ and T₄ were observed. Compared to the previous time point, T₃ showed a significant decrease at 20days and at 60days (p<0.01), while a significant increase was observed at 90days and 210days (p<0.05); T₄ showed a significant decrease at 20days (p<0.01), while significant increases were observed at both 180days and 210days (p<0.05); GAGs showed a significant increase at 120days and 210days (p<0.05). Positive and significant correlations between BW and GAGs in both males (p<0.0057) and females (p<0.0059) were observed.

Conclusion:

It can be concluded that the highest T₃ and T₄ concentrations have been associated with the early growing process (10days), with an increasing trend also at 210days, it is possible to hypothesize a probable metabolic effect of thyroid function in anabolic and/or catabolic directions during the calves’ development. Likewise, it can be reasonably inferred that the highest plasma GAGs at 210days may be due to their metabolic role during the development of growing calves. Taken together, these findings suggest the potential and relative contribution made by thyroid and GAGs effects on the dynamics of growing calves.

Hypothyroidism induces uterine hyperplasia and inflammation related to sex hormone receptors expression in virgin rabbits

AIMS

In women, uterine alterations have been associated with sex steroid hormones. Sex hormones regulate the expression of thyroid hormone receptors (TRs) in the uterus, but an inverse link is unknown. We analyzed the impact of hypothyroidism on histological characteristics, vascular endothelial growth factor (VEGF-A), progesterone receptors (PR), estrogen receptors (ER), thyroid hormone receptors (TRs), perilipin (PLIN-A), and lipid content in the uterus of virgin rabbits.

MAIN METHODS

Twelve Chinchilla-breed adult female rabbits were grouped into control (n = 6) and hypothyroid (n = 6; 0.02% of methimazole for 30 days). The thickness of endometrium and myometrium, number of uterine glands, and infiltration of immune cells were analyzed. The expression of VEGF-A, PR, ERα, and PLIN-A was determined by RT-PCR and western blot. The uterine content of triglycerides (TAG), total cholesterol (TC), and malondialdehyde (MDA) was quantified.

KEY FINDINGS

Hypothyroidism promoted uterine hyperplasia and a high infiltration of immune cells into the endometrium, including macrophages CD163+. It also increased the expression of VEGF-A, TRA, and ERα-66 but reduced that of PR and ERα-46. The uterine content of PLIN-A, TAG, and TC was reduced, but that of MDA was augmented in hypothyroid rabbits.

SIGNIFICANCE

Our results suggest that uterine hyperplasia and inflammation promoted by hypothyroidism should be related to changes in the VEGF-A, PR, ER, and TRs expression, as well as to modifications in the PLIN-A expression, lipid content, and oxidative status. These results suggest that hypothyroidism should affect the fertility of females.