Maternal protein deficiency impairs peroxisome biogenesis and leads to oxidative stress and ferroptosis in liver of fetal growth restriction offspring.

Maternal protein malnutrition leads to liver dysfunction and increases susceptibility to nonalcoholic fatty liver disease in adult fetal growth restriction (FGR) offspring, yet the underlying mechanism remains unknown. Peroxisomes play vital roles in fatty acid ß-oxidation (FAO) and detoxification of reactive oxygen species (ROS). Using a well-defined rat model, the peroxins (PEXs), fatty acid metabolic enzymes, and oxidase stress regulators were investigated in the liver of FGR offspring. The results revealed that PEX3, 11b, 14, and 19 were obviously reduced in the fetal liver and lasted to adulthood, suggesting a decrease in the biogenesis and division of peroxisomes. FA metabolism enzymes and ferroptosis regulators were deregulated. To further investigate this association, small interfering RNA was employed to achieve knockdown (KD) of PEX14 in BRL cells (a rat hepatocyte line). PEX14 KD led to dysregulation of PEXs and long-chain FAs accumulation. PEX14 deficiency caused ROS accumulation and lipid peroxidation, finally induced regulated cell death (including apoptosis, autophagy, and ferroptosis). Double knock down (DKD) of PEX14 and fatty acyl-CoA reductase 1 (FAR1) revealed that PEX14 KD-induced ferroptosis was related with enhanced FAR1 level. DKD of PEX14 and Atg5 further confirmed that PEX14 KD-induced cell death was partly autophagy-dependent. Overall, these data demonstrate a vital role for PEX14 in maintaining peroxisome function and liver physiology, and suggest that hepatocyte peroxisome defects partly explain liver dysplasia and lipid metabolism disorders in fetal original liver disease.

YTHDC1 maintains trophoblasts function by promoting degradation of m6A-modified circMPP1.

N6-methyladenosine (m6A) is the most abundant mRNA internal modification in eukaryotic mRNAs. This study focuses on the effect of circMPP1 on placental villi function and the molecular mechanism. First, differentially expressed circular RNAs (circRNAs) in placenta tissues of large-for-gestational-age(LGA) neonates were screened by m6A-circRNA Epitranscriptomic Microarray and bioinformatics analyses. The abnormal expression of circMPP1 in placental tissues and cell lines was validated by RT-qPCR. In-vitro and in-vivo functional experiments were performed to evaluate the role of circMPP1 in placental impairment and fetal dysplasia. The interacting proteins of circMPP1 were identified and validated using RNA pull-down, RNA immunoprecipitation, fluorescence in situ hybridization, and immunofluorescence experiments. Protein interactions and expression levels were detected by Co-immunoprecipitation and western blot analysis. The m6A modification in circMPP1 was verified by methylated RNA immunoprecipitation assay. Bioinformatics analyses showed that circMPP1 was highly expressed in tissues with disordered placental function. In-vitro and in-vivo functional experiments showed that circMPP1 inhibited the function of placental villi. Further mechanism analyses showed that circMPP1 activated the NF-kappa B and MAPK3 signaling pathways. In addition, the m6A "reader" protein YTHDC1 was found to reduce circMPP1 expression via m6A modification. In conclusion, this study demonstrates that YTHDC1 maintains trophoblasts function by promoting degradation of m6A-mediated circMPP1.

N6-methyladenosine modification in trophoblasts promotes circSETD2 expression, inhibits miR-181a-5p, and elevates MCL1 transcription to reduce apoptosis of trophoblasts.

Preeclampsia (PE) is an obstetric disorder. N6-methyladenosine (m6A) modification is related to PE trophoblast biological behaviors. This study explored the mechanism of m6A-modified circSETD2 in trophoblast biological behaviors. Chorionic trophoblast apoptosis and circSETD2 expression in PE rat models were detected. HTR8/SVneo cells were induced by CoCl2 to establish PE trophoblast models. circSETD2 was silenced or overexpressed to evaluate its effect on cell proliferation, invasion, and apoptosis. m6A level of circSETD2 in trophoblasts was changed by pcDNA3.1-METTL3 and pcDNA3.1-FTO. The targeting relations among miR-181a-5p, circSETD2, and MCL1 were verified by dual-luciferase assay. miR-181a-5p and MCL1 expressions were interfered with to confirm the effect of m6A-modified circSETD2. m6A methylation level was changed in PE rats for in vivo validation. PE rats showed diminished circSETD2 expression and increased apoptosis index. circSETD2 overexpression promoted trophoblast proliferation and invasion, and reduced apoptosis. METTL3 overexpression increased total m6A, circSETD2 m6A, and circSETD2 levels. m6A modification mediated circSETD2 upregulation. circSETD2 was a sponge of miR-181a-5p to elevate MCL1 transcription. miR-181a-5p overexpression or MCL1 silencing annulled the role of m6A-modified circSETD2. circSETD2 inhibition negated suppression of METTL3 overexpression on chorionic trophoblast apoptosis in vivo. Collectively, m6A modification of circSETD2 suppressed miR-181a-5p and increased MCL1 transcription, thus regulating trophoblasts.

Cigarette smoke-induced trophoblast cell ferroptosis in rat placenta and the effects of L-arginine intervention.

Cigarette smoke (CS) disrupts placental development, and impairs fetal health and maternal fertility, thus resulting in low birth weight, premature delivery, and spontaneous abortion; however, the underlying mechanisms remain unclear. This study investigated the mechanism through which CS impairs placental trophoblast cell viability and function. An in vivo study in pregnant rats exposed to CS indicated that CS- exposure decreased antioxidant factors expression and blocked NRF2 activation in the placenta. Anti-ferroptosis regulators expression was downregulated, and pro-ferroptosis regulators expression was upregulated in placentas from CS-exposed rats. Further analysis revealed that cigarette smoke extract (CSE) led to peroxins downregulation and decreased the number of peroxisomes. An in vitro study in HTR-8/SVneo(HTR-8) cells showed that CSE led to free iron and ROS accumulation, and subsequently induced lipid peroxidation and cell death. Ferroptosis inhibitors and the antioxidant L-arginine (ARG) partially inhibited CSE-induced cell death. ARG partially alleviated the toxic effects of CSE by promoting antioxidant factors expression in placenta and suppressing HTR-8 cell ferroptosis. Knockdown of PEX14, a peroxisome biogenesis marker, led to the downregulation of multiple PEXs, thus increasing intracellular H2O2 levels and inducing HTR-8 cell ferroptosis. These findings demonstrated that ferroptosis is responsible for CSE-induced trophoblast cell death and suggest that peroxisome dysfunction is involved in CSE-induced ferroptosis. Therefore, CSE-induced ferroptosis may serve as a potential therapeutic target for preventing adverse pregnancy outcomes.

Effect of Human Umbilical Cord Mesenchymal Stem Cell Transplantation in a Rat Model of Preeclampsia.

OBJECTIVE: To test the effects of human umbilical cord mesenchymal stem cell (HU-MSC) transplantation on reversing preeclampsia (PE) symptoms in a lipopolysaccharide (LPS)-induced rat PE model. METHODS: Human umbilical cord MSCs were detected, isolated, and cultured. Human umbilical cord MSC transplantation was conducted. Expressions of inflammatory cytokines in serum and placental tissue were measured by enzyme-linked immunosorbent assay. Changes in inflammatory cytokines, peroxisome proliferator-activated receptor γ (PPARγ), laminin receptor 1 (LR1), matrix metalloproteinase (MMP) 2, and MMP-9 messenger RNA (mRNA) levels in placental tissue were recorded by quantitative real-time polymerase chain reaction. Immunohistochemistry and Western blotting were performed for PPARγ detection. RESULTS: The LPS group exhibited increased blood pressure and proteinuria and decreased fetal weight compared to the normal pregnancy (NP) group (all P < .05). The LPS + MSC group presented lowered blood pressure and higher fetal weight than the LPS group (P < .05). The levels of interferon γ, tumor necrosis factor α (TNF-α), interleukin (IL) 1ß, IL-6, IL-8, IL-12, and intercellular adhesion molecule 1 (ICAM-1) increased and the levels of IL-4 and IL-10 levels decreased in the LPS group compared to the NP group (all P < .05). Tumor necrosis factor α, IL-6, IL-12, and ICAM-1 levels decreased and IL-10 level increased in the LPS + MSC group compared to the LPS group (all P < .05). The LPS-MSC group showed lower mRNA expressions of TNF-α, IL-6, MMP-2, MMP-9, and ICAM-1 and higher mRNA expressions of IL-10, PPARγ, and LR1 than the LPS group (all P < .05). CONCLUSION: In summary, HU-MSC transplantation may be extremely beneficial for PE therapy.

Beneficial effect of human umbilical cord-derived mesenchymal stem cells on an endotoxin-induced rat model of preeclampsia.

Mesenchymal stem cells (MSCs), which exhibit the property of immune-modulation, have been shown to treat various diseases, including pulmonary hypertension. There is a functional similarity between the pulmonary circulation and the placenta, but it remains to be elucidated whether MSCs can be applied to treat endotoxin-induced hypertension during pregnancy; therefore, the aim of the present study was to investigate the therapeutic effect of a human umbilical cord-derived MSC infusion on endotoxin-induced hypertension during pregnancy. Rats were randomly divided into three groups (n=7 per group): Control, endotoxin-treated and endotoxin + MSCs. The model of preeclampsia (PE) was established via the intravenous injection of endotoxin. In the endotoxin + MSCs group, MSCs at 2×106 cells/rat were injected via the vena caudalis. The blood pressure, urine protein and number of white blood cells were measured. In addition, the protein expression levels of the pro-inflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor-α (TNF-α) and the anti-inflammatory cytokine IL-10 were examined by ELISA. The blood pressure, levels of urine protein and number of white blood cells in the endotoxin-treated group were significantly higher than those in the control group (P<0.05); however, this increase was significantly attenuated in the endotoxin + MSCs group (P<0.05). In addition, the application of MSCs significantly reduced the levels of pro-inflammatory TNF-α and IL-1ß and increased the levels of anti-inflammatory IL-10 in the endotoxin-treated rats. In conclusion, umbilical cord-derived MSCs have a protective effect in an endotoxin-induced model of PE, and this effect is likely elicited through the suppression of inflammatory factors. Umbilical cord-derived MSC-based therapy may provide a potential therapeutic method for endotoxin-induced hypertension during pregnancy.

67-kDa Laminin receptor contributes to hypoxia-induced migration and invasion of trophoblast-like cells by mediating matrix metalloproteinase-9.

Insufficient trophoblast invasion often occurs in patients experiencing preeclampsia. The 67-kDa laminin receptor (LR1) is a multifunctional protein that binds to laminin and interacts with the extracellular matrix. We recently demonstrated that LR1 is implicated in trophoblast migration and invasion. However, whether LR1 is involved in hypoxia-mediated trophoblastic invasion remains unclear and requires further investigation. This study demonstrates that two trophoblast-like cell lines (JEG3 and BeWo cells) cultured at 3% oxygen exerted enhanced migratory and invasive capabilities as compared with their counterparts exposed to 20% oxygen. LR1 expression was increased in hypoxic JEG3 cells but decreased after transfection with hypoxia-inducible factor 1 alpha (HIF-1α) specific siRNA. Moreover, shRNA targeting LR1 mRNA significantly inhibited hypoxia-induced increase in matrix metalloproteinase (MMP)-9 activity in JEG3 cells. Forced overexpression of LR1 augmented JEG3 cell migration and invasion, and enhanced MMP-9 expression and activity. Additionally, the blockade of the MMP-9 effect with its neutralizing antibody reduced LR1 elevation-promoted trophoblastic invasion. In summary, this study demonstrates that LR1 contributes to hypoxia-induced migration and invasion of trophoblast cells at least partly by mediating MMP-9 in vitro.

Parity and pancreatic cancer risk: a dose-response meta-analysis of epidemiologic studies.

BACKGROUND: Previous epidemiologic studies have reported inconsistent results between parity and pancreatic cancer (PC) risk. To our knowledge, a comprehensive and quantitative assessment of this association has not been conducted. METHODS: Relevant published studies of parity and PC were identified using MEDLINE (PubMed) and Web of Science databases until November 2013. Two authors (H-BG and LW) independently assessed eligibility and extracted data. Eleven prospective and 11 case-control studies reported relative risk (RR) estimates and 95% confidence intervals (CIs) of PC associated with parity. Fixed- and random-effects models were used to estimate the summary RR depending on the heterogeneity of effects. RESULTS: The summary RR for PC comparing the highest versus lowest parity was 0.86 (95% CI: 0.73-1.02; Q = 50.49, P<0.001, I2 = 58.4%). Significant inverse associations were also observed in the studies that adjusted for cigarette smoking (RR = 0.81; 95% CI: 0.68-0.98), Type 2 diabetes mellitus (RR = 0.83; 95% CI: 0.75-0.93), and those that included all confounders or important risk factors (RR = 0.85; 95% CI: 0.76-0.96). Additionally, in the dose-response analysis, the summary RR for per one live birth was 0.97 (95% CI: 0.94-1.01; Q = 62.83, P<0.001, I2 = 69.8%), which also indicated a borderline statistically significant inverse effect of parity on PC risk. No evidence of publication bias and significant heterogeneity between subgroups were detected by meta-regression analyses. CONCLUSION: In summary, these findings suggest that higher parity is associated with a decreased risk of PC. Future large consortia or pooled studies are warranted to fully adjust for potential confounders to confirm this association.

Parity and risk of colorectal cancer: a dose-response meta-analysis of prospective studies.

BACKGROUND: Association between parity and colorectal cancer (CRC) risk has been investigated by several epidemiological studies but results are controversial, yet a comprehensive and quantitative assessment of this association has not been reported so far. METHODS: Relevant published studies of parity and CRC were identified using MEDLINE, EMBASE and Web of Science databases through end of April 2013. Two authors independently assessed eligibility and extracted data. Eleven prospective studies reported relative risk (RR) estimates and 95% confidence intervals (CIs) of CRC risk associated with parity. We pooled the RR from individual studies using fixed- or random-effects models and carried out heterogeneity and publication bias analyses. RESULTS: The summary RR for the ever parity vs. nulliparous was 0.95 (95% CI: 0.88-1.02), with no heterogeneity (Q = 9.04, P = 0.443, I (2) = 0.5%). Likewise, no significant association was yielded for the highest vs. lowest parity number (RR = 1.02, 95% CI: 0.89-1.17), with moderate heterogeneity (Q = 17.48, P = 0.094, I (2) = 37.1%). Dose-response analysis still indicated no effect of parity on CRC risk and the summary RR of per one livebirth was 0.99 (95% CI: 0.96-1.02), with moderate of heterogeneity (Q = 16.50, P<0.021, I (2) = 57.6%). Similar results were observed among all the subgroup analyses. No evidence of publication bias and significant heterogeneity between subgroups were detected by meta-regression analyses. CONCLUSION: Results of this dose-response meta-analysis of prospective studies found that there was little evidence of an association between parity and CRC risk.

Parity and kidney cancer risk: evidence from epidemiologic studies.

BACKGROUND: Observational studies have reported conflicting results between parity and kidney cancer risk. To our knowledge, a comprehensive and quantitative assessment of the association between parity and kidney cancer has not been reported. Thus, we conducted a systematic review and dose-response meta-analysis of published epidemiologic studies to summarize the evidence of this association. METHODS: Relevant published studies of parity and kidney cancer were identified using MEDLINE (PubMed) database through end of June 2013. Two authors independently assessed eligibility and extracted data. Six prospective and eight case-control studies reported relative risk (RR) estimates and 95% confidence intervals (CI) of kidney cancer associated with parity or parity number. Fixed- or random-effects models were used to estimate summary relative risk. RESULTS: The summary relative risk of kidney cancer for the parity versus nulliparous was 1.23 (95% CI, 1.10-1.36; Q = 12.41; P = 0.413; I(2) = 3.3%). In addition, significant association was also found for the highest versus lowest parity number, with summary RR = 1.36 (95% CI, 1.19-1.56; Q = 8.24; P = 0.766; I(2) = 0%). In the dose-response analysis, the summary per one live birth relative risk was 1.08 (95% CI: 1.05-1.10; Q = 9.34; P = 0.500; I(2) = 0%), also indicating the positive effect of parity on kidney cancer risk. No evidence of publication bias and significant heterogeneity between subgroups was detected by meta-regression analyses. CONCLUSIONS: In summary, findings from this meta-analysis suggest that ever parity and higher parity number is significantly associated with increased risk of kidney cancer. IMPACT: The present results suggest a positive association between parity and kidney cancer risk.