ABSTRACT
Imprinting control region (ICR1) controls the expression of the Igf2 and H19 genes in a parent-of-origin specific manner. Appropriate expression of the Igf2-H19 locus is fundamental for normal fetal development, yet the importance of ICR1 in the placental production of hormones that promote maternal nutrient allocation to the fetus is unknown. To address this, we used a novel mouse model to selectively delete ICR1 in the endocrine junctional zone (Jz) of the mouse placenta (Jz-ΔICR1). The Jz-ΔICR1 mice exhibit increased Igf2 and decreased H19 expression specifically in the Jz. This was accompanied by an expansion of Jz endocrine cell types due to enhanced rates of proliferation and increased expression of pregnancy-specific glycoprotein 23 in the placenta of both fetal sexes. However, changes in the endocrine phenotype of the placenta were related to sexually-dimorphic alterations to the abundance of Igf2 receptors and downstream signalling pathways (Pi3k-Akt and Mapk). There was no effect of Jz-ΔICR1 on the expression of targets of the H19-embedded miR-675 or on fetal weight. Our results demonstrate that ICR1 controls placental endocrine capacity via sex-dependent changes in signalling.
Subject(s)
Endocrine Glands/metabolism , Insulin-Like Growth Factor II/genetics , Locus Control Region , Placenta/metabolism , RNA, Long Noncoding/genetics , Signal Transduction , Animals , Female , Genetic Loci , Genomic Imprinting , Glycoproteins/genetics , Glycoproteins/metabolism , Insulin-Like Growth Factor II/metabolism , Male , Mice , Mice, Inbred C57BL , Phosphatidylinositol 3-Kinases/metabolism , Pregnancy , Pregnancy Proteins/genetics , Pregnancy Proteins/metabolism , Proto-Oncogene Proteins c-akt/metabolism , RNA, Long Noncoding/metabolismABSTRACT
Coronaviruses are a big family of viruses that can infect mammalians and birds. In humans they mainly cause respiratory tract infections, with a large spectrum of severity, from mild, self-limited infections to highly lethal forms as severe acute respiratory syndrome coronavirus (SARS-CoV), Middle East respiratory syndrome coronavirus (MERS-CoV) and Coronavirus Disease 2019 (COVID-19). Scanty data are reported for the involvement of endocrine glands in human coronaviruses, in particular SARS-CoV-2. In this review, we summarize endocrinological involvement in human coronaviruses, including data on animal coronaviruses. Avians, ferrets and bovine are affected by specific coronavirus syndromes, with variable involvement of endocrine glands. SARS-CoV and SARS-CoV-2 use angiotensin-converting enzyme 2 (ACE2) as a target receptor, so ACE2 plays a central role in viral transmission and initial organ involvement. Autoptic studies on SARS patients revealed that thyroid, parathyroid, pituitary gland, endocrine pancreas and especially adrenals and testis could be impaired by different mechanisms (direct damage by SARS-CoV, inflammation, vascular derangement and autoimmune reactions) and few clinical studies have evidenced functional endocrine impairment. Only few data are available for COVID-19 and gonads and endocrine pancreas seem to be involved. International endocrinological societies have brought some recommendations for the COVID-19 pandemic, but further studies need to be performed, especially to detect long-term hormonal sequelae.