Abnormal placental DNA methylation variation in spontaneous preterm birth

Placental circadian lincRNAs and spontaneous preterm birth

Long non-coding RNAs (lncRNAs) have a much higher cell- and/or tissue-specificity compared to mRNAs in most cases, making them excellent candidates for therapeutic applications to reduce off-target effects. Placental long non-coding RNAs have been investigated in the pathogenesis of preeclampsia (often causing preterm birth (PTB)), but less is known about their role in preterm birth. Preterm birth occurs in 11% of pregnancies and is the most common cause of death among infants in the world. We recently identified that genes that drive circadian rhythms in cells, termed molecular clock genes, are deregulated in maternal blood of women with spontaneous PTB (sPTB) and in the placenta of women with preeclampsia. Next, we focused on circadian genes-correlated long intergenic non-coding RNAs (lincRNAs, making up most of the long non-coding RNAs), designated as circadian lincRNAs, associated with sPTB. We compared the co-altered circadian transcripts-correlated lincRNAs expressed in placentas of sPTB and term births using two published independent RNAseq datasets (GSE73712 and GSE174415). Nine core clock genes were up- or downregulated in sPTB versus term birth, where the RORA transcript was the only gene downregulated in sPTB across both independent datasets. We found that five circadian lincRNAs (LINC00893, LINC00265, LINC01089, LINC00482, and LINC00649) were decreased in sPTB vs term births across both datasets (p ≤ .0222, FDR≤.1973) and were negatively correlated with the dataset-specific clock genes-based risk scores (correlation coefficient r = -.65 ∼ -.43, p ≤ .0365, FDR≤.0601). Gene set variation analysis revealed that 65 pathways were significantly enriched by these same five differentially expressed lincRNAs, of which over 85% of the pathways could be linked to immune/inflammation/oxidative stress and cell cycle/apoptosis/autophagy/cellular senescence. These findings may improve our understanding of the pathogenesis of spontaneous preterm birth and provide novel insights into the development of potentially more effective and specific therapeutic targets against sPTB.

The Placental Epigenome as a Molecular Link Between Prenatal Exposures and Fetal Health Outcomes Through the DOHaD Hypothesis

PURPOSE OF REVIEW

The developmental origins of health and disease (DOHaD) hypothesis posits that the perinatal environment can impact fetal and later life health. The placenta is uniquely situated to assess prenatal exposures in the context of DOHaD because it is an essential ephemeral fetal organ that manages the transport of oxygen, nutrients, waste, and endocrine signals between the mother and fetus. The purpose of this review is to summarize recent studies that evaluated the DOHaD hypothesis in human placentas using epigenomics, including DNA methylation and transcriptomic studies of mRNA, lncRNA, and microRNAs.

RECENT FINDINGS

Between 2016 and 2021, 28 articles evaluated associations between prenatal exposures and placental epigenomics across broad exposure categories including maternal smoking, psychosocial stressors, chemicals, air pollution, and metals. Sixteen of these studies connected exposures to health outcome such as birth weight, fetal growth, or infant neurobehavior through mediation analysis, identification of shared associations between exposure and outcome, or network analysis. These aspects of infant and childhood health serve as a foundation for future studies that aim to use placental epigenetics to understand relationships between the prenatal environment and perinatal complications (such as preterm birth or fetal growth restriction) or later life childhood health. Placental DNA methylation and RNA expression have been linked to numerous prenatal exposures, such as PM2.5 air pollution, metals, and maternal smoking, as well as infant and childhood health outcomes, including fetal growth and birth weight. Placental epigenomics provides a unique opportunity to expand the DOHaD premise, particularly if research applies novel methodologies such as multi-omics analysis, sequencing of non-coding RNAs, mixtures analysis, and assessment of health outcomes beyond early childhood.

The protective effect of carvacrol on acetaminophen-induced renal damage in male rats

BACKGROUND

Acetaminophen overdose causes renal injury via oxidative stress and apoptosis induction. Carvacrol has several pharmacological properties such as antioxidant, anti-inflammation and anti-apoptotic effect. The aim of this study was to determine the protective effect of carvacrol on acetaminophen-induced renal damage in rats.

METHODS AND RESULTS

Forty male Wistar rats were randomly divided to five groups (n = 8) including control, carvacrol 10 mg/kg, acetaminophen, acetaminophen + carvacrol 5 mg/kg, and acetaminophen + carvacrol 10 mg/kg. Animals received a single dose of acetaminophen (500 mg/kg), then were treated with carvacrol for 1 week (daily). Afterwards, renal blood flow (RBF), mean arterial pressure, renal perfusion pressure, renal vascular resistance (RVR), blood urea nitrogen (BUN), and serum creatinine were measured. Also, malondialdehyde (MDA) concentration, glutathione peroxidase (GPx) and superoxide dismutase (SOD) activity levels were measured in the kidney tissue. Hematoxylin and eosin method was used for histological assessment. The Western blotting analysis was used to determine the Bax, Bcl-2 and cleaved caspase-3 proteins expression level in the kidney tissue. Carvacrol (10 mg/kg) significantly increased the RBF, GPx and SOD activities and also reduced the RVR, serum creatinine, BUN, and MDA in the acetaminophen + carvacrol 10 mg/kg group versus acetaminophen group (P < 0.05). Also, carvacrol significantly decreased the cleaved caspase-3, Bax proteins expression level, and kidney tissue damage score in the acetaminophen + carvacrol 10 mg/kg group versus acetaminophen group (P < 0.05).

CONCLUSIONS

This study showed that carvacrol can attenuate the acetaminophen induced acute kidney damage via suppressing oxidative stress and apoptosis biochemical factors.

Ubiquitin-Specific Peptidase 5 is Involved in the Proliferation of Trophoblast Cells by Regulating Wnt/β-Catenin Signaling

Preeclampsia (PE) is a pathologic condition in pregnant women which accounts for the inhibition of proliferation, migration and invasion of trophoblast cells. This study aimed to investigate the regulation of ubiquitin-specific peptidase 5 (USP5) on the trophoblast cells in PE. Expressions of USP5 in the placentas of PE patients and healthy donors were examined by qRT-PCR and Western blot. Hypoxia/reoxygenation (H/R) model in trophoblast cells was further established. Cell viability was examined using CCK-8 assay. Finally, the effect of overexpression and silence of USP5 using lentivirus transduction was studied. Our results showed that USP5 was lowly expressed in the placentas of PE patients as well as in H/R-induced trophoblast cells. In the experiments of overexpression, USP5 promoted the proliferation of trophoblast cells, and up-regulated the expressions of β-catenin and the downstream signals c-Myc and Cyclin D1 in trophoblast cells. On the other hand, silence of USP5 elicited the opposite results. The overexpression of USP5 in the H/R model greatly released the H/R-induced inhibition in the trophoblast cells, and moderated the down-regulation of β-catenin and c-Myc induced by H/R. We concluded that USP5 promoted the proliferation of trophoblast cells via the up-regulation of the Wnt/β-catenin signaling pathway.