Roles of PPARγ/NF-κB signaling pathway in the pathogenesis of intrahepatic cholestasis of pregnancy

Unlocking new avenues for neuropsychiatric disease therapy: the emerging potential of Peroxisome proliferator-activated receptors as promising therapeutic targets

RATIONALE

Peroxisome proliferator-activated receptors (PPARs) are transcription factors that regulate various physiological processes such as inflammation, lipid metabolism, and glucose homeostasis. Recent studies suggest that targeting PPARs could be beneficial in treating neuropsychiatric disorders by modulating neuronal function and signaling pathways in the brain. PPAR-α, PPAR-δ, and PPAR-γ have been found to play important roles in cognitive function, neuroinflammation, and neuroprotection. Dysregulation of PPARs has been associated with neuropsychiatric disorders like bipolar disorder, schizophrenia, major depression disorder, and autism spectrum disorder. The limitations and side effects of current treatments have prompted research to target PPARs as a promising novel therapeutic strategy. Preclinical and clinical studies have shown the potential of PPAR agonists and antagonists to improve symptoms associated with these disorders.

OBJECTIVE

This review aims to provide an overview of the current understanding of PPARs in neuropsychiatric disorders, their potential as therapeutic targets, and the challenges and future directions for developing PPAR-based therapies.

METHODS

An extensive literature review of various search engines like PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out with the keywords "PPAR, Neuropsychiatric disorders, Oxidative stress, Inflammation, Bipolar Disorder, Schizophrenia, Major depression disorder, Autism spectrum disorder, molecular pathway".

RESULT & CONCLUSION

Although PPARs present a hopeful direction for innovative therapeutic approaches in neuropsychiatric conditions, additional research is required to address obstacles and convert this potential into clinically viable and individualized treatments.

FGF21 Inhibits Hypoxia/Reoxygenation-induced Renal Tubular Epithelial Cell Injury by Regulating the PPARγ/NF-κB Signaling Pathway

As a predominant trigger of acute kidney injury, renal ischemia-reperfusion injury can cause permanent renal impairment, and the effective therapies are lacking. Fibroblast growth factor 21 (FGF21) plays a critical regulatory role in a variety of biological activities. This study was conducted to explore the functional of FGF21 in renal ischemia-reperfusion injury and to discuss the hidden reaction mechanism. To simulate renal ischemia-reperfusion injury in vitro, HK2 cells were induced by hypoxia/reoxygenation (H/R). The effects of FGF21 on H/R-induced HK2 cell viability were evaluated utilizing cell counting kit-8 (CCK-8). The levels of lactate dehydrogenase (LDH) and inflammatory cytokines in H/R-induced HK2 cells were assessed by means of LDH assay and enzyme-linked immunosorbent assay (ELISA). The levels of oxidative stress markers were appraised with corresponding assay kits and western blot was applied to estimate the expressions of oxidative stress-related proteins. The apoptosis of H/R-induced HK2 cells was assessed by virtue of flow cytometry. The expressions of apoptosis- and PPARγ/NF-κB signaling pathway-related proteins were evaluated with western blot. To discuss the reaction mechanism of PPARγ/NF-κB pathway in H/R-induced HK2 cells, PPARγ inhibitor GW9662 was employed to treat cells and the above experiments were then conducted again. This study found that FGF21 treatment inhibited the inflammatory response, oxidative stress and apoptosis in H/R-induced HK2 cells. Moreover, FGF21 regulated PPARγ/NF-κB signaling pathway and GW9662 partially reversed the impacts of FGF21 on the inflammatory response, oxidative stress and apoptosis in H/R-exposed HK2 cells. Collectively, FGF21 protected against H/R-induced renal tubular epithelial cell injury by regulating the PPARγ/NF-κB signaling pathway.

Serum placental growth factor, total cholesterol, and triglycerides for prediction of intrahepatic cholestasis of pregnancy

This study aims to investigate the predictive values of serum placental growth factor (PIGF), total cholesterol (TC), and triglycerides (TG) in the context of intrahepatic cholestasis of pregnancy (ICP). This retrospective case control study recruited pregnant women from January 2021 to December 2021 at the Maternal and Child Health Hospital of Hunan Province, encompassing pregnant women diagnosed with ICP and those with unremarkable prenatal examinations. A total of 433 pregnant women were included, among whom 167 were diagnosed with ICP after 24 weeks of pregnancy. Patients with ICP exhibited an average age of 31.30 ± 4.54 years and an average pregnancy week at delivery of 37.63 ± 1.45 weeks. Multivariable regression analysis showed that the pregnancy week at delivery (OR = 0.823, 95% CI: 0.769-0.879, P < .001), PIGF (OR = 0.994, 95% CI: 0.992-0.996, P < .001), TC (OR = 1.955, 95% CI: 1.586-2.409, P < .001), and TG (OR = 3.786, 95% CI: 2.655-5.399, P < .001) were independent risk factors for ICP. The area under the curve values for PIGF, TC, and TG in predicting ICP were 0.858 (95% CI: 0.822-0.893), 0.721 (95% CI: 0.670-0.772), and 0.830 (95% CI: 0.788-0.871), respectively. However, their combination yielded an area under the curve value of 0.922 (95% CI: 0.898-0.946). The composite assessment of PIGF, TC, and TG demonstrates potential efficacy in predicting ICP among pregnant women.

PPARG stimulation restored lung mRNA expression of core clock, inflammation- and metabolism-related genes disrupted by reversed feeding in male mice

The circadian rhythm system regulates lung function as well as local and systemic inflammations. The alteration of this rhythm might be induced by a change in the eating rhythm. Peroxisome proliferator-activated receptor gamma (PPARG) is a key molecule involved in circadian rhythm regulation, lung functions, and metabolic processes. We described the effect of the PPARG agonist pioglitazone (PZ) on the diurnal mRNA expression profile of core circadian clock genes (Arntl, Clock, Nr1d1, Cry1, Cry2, Per1, and Per2) and metabolism- and inflammation-related genes (Nfe2l2, Pparg, Rela, and Cxcl5) in the male murine lung disrupted by reversed feeding (RF). In mice, RF disrupted the diurnal expression pattern of core clock genes. It decreased Nfe2l2 and Pparg and increased Rela and Cxcl5 expression in lung tissue. There were elevated levels of IL-6, TNF-alpha, total cells, macrophages, and lymphocyte counts in bronchoalveolar lavage (BAL) with a significant increase in vascular congestion and cellular infiltrates in male mouse lung tissue. Administration of PZ regained the diurnal clock gene expression, increased Nfe2l2 and Pparg expression, and reduced Rela, Cxcl5 expression and IL-6, TNF-alpha, and cellularity in BAL. PZ administration at 7 p.m. was more efficient than at 7 a.m.

Cardiovascular complications are resolved by tuna protein hydrolysate supplementation in rats fed with a high-fat diet

This study is aimed to investigate whether tuna protein hydrolysate (TPH) supplementation could alleviate cardiovascular complications induced by a high-fat diet (HFD) in rats. Rats were fed a HFD for 16 weeks and given TPH (100 mg/kg, 300 mg/kg, or 500 mg/kg) or metformin (100 mg/kg) (n = 8) for the last four weeks. TPH had the following effects: resolved their impaired glucose tolerance, hyperglycemia, dyslipidemia, obesity, and hypertension (p < 0.05); alleviated left ventricular dysfunction and hypertrophy (p < 0.05), and vascular dysfunction and hypertrophy (p < 0.05); adipocyte hypertrophy; increases in circulating leptin and tumor necrosis factor (TNF-α) were mitigated (p < 0.05); increased renin-angiotensin system (RAS), oxidative stress, and decreased nitric oxide metabolites were modulated (p < 0.05). TPH restored the expression of angiotensin II receptor type 1 (AT1R)/NADPH oxidase 2 (NOX2), endothelial nitric oxide synthase (eNOS), nuclear factor erythroid 2-related factor (Nrf2)/heme oxygenase-1 (HO-1), and peroxisome proliferator-activated receptor γ (PPARγ)/the nuclear factor kappa B (NF-κB) protein in cardiovascular tissue (p < 0.05). In metabolic syndrome (MS) rats, metformin and TPH had comparable effects. In conclusion, TPH alleviated cardiovascular complications related to MS. It suppressed RAS, oxidative stress, and inflammation that were associated with modulation of AT1R/NOX2, eNOS, Nrf2/HO-1, and PPARγ/NF-κB expression.

Ginsenosides Restore Lipid and Redox Homeostasis in Mice with Intrahepatic Cholestasis through SIRT1/AMPK Pathways

Intrahepatic cholestasis (IC) occurs when the liver and systemic circulation accumulate bile components, which can then lead to lipid metabolism disorders and oxidative damage. Ginsenosides (GS) are pharmacologically active plant products derived from ginseng that possesses lipid-regulation and antioxidation activities. The purpose of this study was to evaluate the possible protective effects of ginsenosides (GS) on lipid homeostasis disorder and oxidative stress in mice with alpha-naphthylisothiocyanate (ANIT)-induced IC and to investigate the underlying mechanisms. A comprehensive strategy via incorporating pharmacodynamics and molecular biology technology was adopted to investigate the therapeutic mechanisms of GS in ANIT-induced mice liver injury. The effects of GS on cholestasis were studied in mice that had been exposed to ANIT-induced cholestasis. The human HepG2 cell line was then used in vitro to investigate the molecular mechanisms by which GS might improve IC. The gene silencing experiment and liver-specific sirtuin-1 (SIRT1) knockout (SIRT1^LKO) mice were used to further elucidate the mechanisms. The general physical indicators were assessed, and biological samples were collected for serum biochemical indexes, lipid metabolism, and oxidative stress-related indicators. Quantitative PCR and H&E staining were used for molecular and pathological analysis. The altered expression levels of key pathway proteins (Sirt1, p-AMPK, Nrf2) were validated by Western blotting. By modulating the AMPK protein expression, GS decreased hepatic lipogenesis, and increased fatty acid β-oxidation and lipoprotein lipolysis, thereby improving lipid homeostasis in IC mice. Furthermore, GS reduced ANIT-triggered oxidative damage by enhancing Nrf2 and its downstream target levels. Notably, the protective results of GS were eliminated by SIRT1 shRNA in vitro and SIRT1^LKO mice in vivo. GS can restore the balance of the lipid metabolism and redox in the livers of ANIT-induced IC models via the SIRT1/AMPK signaling pathway, thus exerting a protective effect against ANIT-induced cholestatic liver injury.

Intrahepatic cholestasis of pregnancy and maternal dyslipidemia: a systematic review and meta-analysis

INTRODUCTION

The association between intrahepatic cholestasis of pregnancy (ICP) and maternal lipid metabolism remains unknown. This systematic review and meta-analysis aimed to evaluate the association between ICP and maternal lipid metabolism.

MATERIAL AND METHODS

We systematically searched Medline, Embase and the Cochrane Library (up to December 11, 2021) to identify relevant studies that investigated ICP and maternal plasma lipid concentrations. The weighted mean difference (WMD) and 95% confidence intervals (CI) were calculated using random-effects models. A subgroup analysis was conducted to identify the potential sources of heterogeneity. Potential publication bias was tested using funnel plots and the Egger's and Begg's tests. This meta-analysis was registered with PROSPERO (CRD42021293783).

RESULTS

Eleven studies were included in this qualitative analysis. A random-effects meta-analysis of data from the final included nine studies (n = 786 participants) showed a significant association between ICP and maternal dyslipidemia, with elevated levels of triglycerides (WMD, 0.67 mmol/L; 95% CI 0.39-0.95; P < 0.001), total cholesterol (WMD, 1.08 mmol/L; 95% CI 0.58-1.58; P < 0.001), low-density lipoprotein cholesterol (WMD, 1.08 mmol/L; 95% CI 0.53-1.64; P < 0.001), and reduced high-density lipoprotein cholesterol level (WMD, -0.38 mmol/L; 95% CI -0.53 to -0.23; P < 0.001) vs normal pregnancies.

CONCLUSIONS

The present study's findings support an association between ICP and maternal dyslipidemia. ICP pregnancies have dysregulated lipid metabolism vs normal pregnancies.

Immune Dysfunction Mediated by the ceRNA Regulatory Network in Human Placenta Tissue of Intrahepatic Cholestasis Pregnancy

Pregnancy-related intrahepatic cholestasis (ICP) is a serious complication with adverse perinatal outcomes of preterm labor, fetal distress, or stillbirth. As a result, it is important to investigate and identify the potential critical pathogenic mechanisms of ICP. First, we collected the placental tissues from the ICP with placental weight and fetal birth weight loss for the whole transcriptome sequencing. Then we analyzed the differentially expressed (DE) circRNAs (DEcircRNAs) by SRPBM, DElncRNAs by FRKM, DEmiRNAs by TPM, and DEmRNAs by TPM and RSEM. Based on differential expression of term pregnancy placental tissues from pregnancies impacted by ICP (n=7) as compared to gestational aged matched control tissues (n=5), the circ/lncRNA-miRNA-mRNA competitive endogenous RNA (ceRNA) regulatory networks were constructed. The ceRNA regulatory networks covered 3,714 events, including 21 DEmiRNAs, 36 DEcircRNAs, 146 DElncRNAs, and 169 DEmRNAs. According to the functional analysis, ICP complications were linked to the immune system, signal transduction, endocrine system, cell growth and death, and transport and catabolism. Further evidence suggested that the expression of immune-related genes KLRD1, BRAF, and NFATC4 might have a potential ceRNA mechanism by individual lncRNA sponging miR372-3p, miR-371a-3p, miR-7851-3p, and miR-449a to control downstream the level of TNF-α, IFN-γ, and IL-10, thereby regulating the pathophysiology of ICP. Furthermore, our results were validated by the qRT-PCR, western blotting and ELISA assays. In conclusion, this study is the first to evaluate placental ceRNA networks in pregnancies affected by ICP, showing alterations in immune regulatory networks which may impact fetal and placental growth. Overall our these data suggest that the ceRNA regulatory network may refine biomarker predictions for developing novel therapeutic approaches in ICP.

miR-27b inhibition contributes to cytotoxicity in patulin-exposed HEK293 cells

Patulin (PAT) is a mycotoxin produced by Penicillium and other fungi that contaminate fruit. PAT targets the kidney and is associated with nephrotoxicity. Micro-RNAs (miRNA) may offer new insights into PAT-induced nephrotoxicity. Cytochrome P₄₅₀ family 1, subfamily B, polypeptide 1 (CYP1B1), involved in metabolism of dietary toxins is negatively regulated by miR-27b and linked with the nuclear factor kappa B (NF-κB) pathway and peroxisome proliferator activated receptor gamma (PPARɣ) in renal fibrosis. This study investigated the effects of PAT on miR-27b, CYP1B1, PPARɣ and cytotoxicity in human kidney (HEK293) cells. HEK293 cells were exposed to PAT (2.5 μM, 24h). Protein expression of CYP1B1, PPARɣ, NF-κB (p65), pNF-κB (p65) (phospho-Ser563) and cleaved PARP-1 was quantified using western blotting. QPCR evaluated mRNA levels of CYP1B1, IL-6, miR-27b, OGG1, mtDNA, TFAM and UCP2. Mitochondrial membrane potential and phosphatidylserine (PS) externalization was evaluated by flow cytometry while levels of ATP and caspase -9, -8, -3/7 activity was measured using luminometry. PAT significantly decreased miR-27b levels (p = 0.0014) and increased CYP1B1 mRNA (p = 0.0015) and protein (p = 0.0013) levels. PPARɣ protein expression was significantly increased (p = 0.0002) and associated with decreased NF-κB activation (p = 0.0273) and IL-6 mRNA levels (p = 0.0265). Finally, PAT significantly compromised mitochondrial repair mechanisms and increased apoptotic biomarkers. PAT altered miR-27b levels and PPARɣ, with associated changes to NF-κB activation, downstream IL-6 and CYP1B1 expression. These results show that PAT impairs detoxification mechanisms leading to mitochondrial damage and apoptosis. In conclusion, PAT altered the epigenetic environment and impaired detoxification processes, supporting a mechanism for nephrotoxic outcomes.

Unfolding newer concepts in placental pathology of obstetric cholestasis-a cause for prematurity

Intrahepatic cholestasis of pregnancy (ICP) has an increased predisposition to occur in the third trimester of pregnancy and has a varied population incidence rates due to genetic influences. Owing to the adverse and unpredictable fetal outcomes, it poses a serious therapeutic challenge to the clinician. A rise in the incidence of iatrogenic prematurity has been observed, raising concerns over the perinatal outcomes. Excess bile acids and altered placental transport mechanisms have been strongly implicated in the pathogenesis of ICP and its complications. The exact etiology is not known; yet major underlying risk factors that are thought to contribute to the disease process include genetic, environmental, hormonal, and immunological. Newer molecular processes acting at the placental level, apart from specific histopathological changes, have assumed significance in recent times. In this review, we attempt to highlight the recent understanding of the mechanisms that operate in the placenta in patients with obstetric cholestasis that lead to poor fetal outcomes, through various studies published in the literature. Despite these additions to the existing knowledge on the etiopathogenesis of obstetric cholestasis and its possible placental origin, further studies are needed to validate the newer concepts.

Establishment of trimester-specific reference intervals of serum lipids and the associations with pregnancy complications and adverse perinatal outcomes: a population-based prospective study

BACKGROUND

Disturbances in maternal lipid metabolism may increase the risk of developing pregnancy complications and adverse perinatal outcomes. However, there is no consensus as to what constitutes normal serum lipid ranges during pregnancy. Our study was aimed to establish trimester-specific serum lipid reference intervals (RIs) and investigate the associations between maternal dyslipidaemia and adverse outcomes in a population-based study.

METHODS

The first- and third-trimester lipid profiles were derived from 16,489 singlet pregnant women for regular antenatal check-ups between 2017 and 2019. The serum samples were assayed for total cholesterol (TC), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), and low-density lipoprotein-cholesterol (LDL-C) in the institutional clinical laboratory. The trimester-specific lipid RIs were estimated with both of the direct observational and the indirect Hoffmann methods. The associations between maternal lipid profiling and pregnancy complications and perinatal outcomes were assessed statistically.

RESULTS

Serum levels of TC, TG, LDL-C and HDL-C were all increased significantly in the third trimester of pregnancy. There was no significant difference between the observed RIs established with healthy pregnant women and the calculated RIs derived from the Hoffmann method. A trend towards increased risks of gestational complications and adverse perinatal outcomes was observed in the subjects with elevated levels of TC, TG, and LDL-C or decreased level of HDL-C.

CONCLUSIONS

In pregnancy, increased serum levels of TC, TG and LDL-C, and a decreased level of HDL-C posed higher risks of developing pregnancy complications and adverse perinatal outcomes.Key messagesIt is necessary to establish trimester-specific reference intervals for serum lipids including TC, TG, LDL-C and HDL-C that were found significantly increased as the gestational age went up. More importantly, around the upper reference limits of TC, TG and LDL-C (or the lower reference limit of HDL-C), the higher the serum lipid levels were (or the lower the HDL-C level was), the higher risks of developing pregnancy complications and adverse perinatal outcomes were observed.

Increased serum delta neutrophil index levels are associated with intrahepatic cholestasis of pregnancy

OBJECTIVE

This study aims to compare the maternal serum delta neutrophil index (DNI) levels in intrahepatic cholestasis of pregnancy (ICP) and healthy pregnancies.

METHODS

This study consisted of a group of patients (n = 40) diagnosed with isolated ICP who gave birth in our hospital and a control group (n = 60) between December 1, 2015, and June 30, 2018. The diagnosis of ICP was made based on pruritus and elevated fasting serum bile acids and liver enzymes. Laboratory tests of both groups in the hospitalization process were retrospectively examined. Maternal and neonatal characteristics, pregnancy outcomes, and DNI values of the two groups were compared. Statistical analyses were performed using SPSS version 20.

RESULTS

Mean maternal serum DNI levels were significantly higher in women with ICP than in the control group (0.49 ± 4.8 vs -3.99 ± 3.02, p = <0.01). Receiver operating characteristic (ROC) curve analysis was used to define the DNI value where ICP can be best predicted.

CONCLUSION

DNI, a new inflammatory marker, was found to be higher in women with ICP than in normal pregnancies.

Peroxisome Proliferator-Activated Receptor-Gamma (PPAR-ɣ): Molecular Effects and Its Importance as a Novel Therapeutic Target for Cerebral Ischemic Injury

Cerebral ischemic injury is a leading cause of death and long-term disability throughout the world. Peroxisome proliferator-activated receptor gamma (PPAR-ɣ) is a ligand-activated nuclear transcription factor that is a member of the PPAR family. PPAR-ɣ has been shown in several in vitro and in vivo models to prevent post-ischemic inflammation and neuronal damage by negatively controlling the expression of genes modulated by cerebral ischemic injury, indicating a neuroprotective effect during cerebral ischemic injury. A extensive literature review of PubMed, Medline, Bentham, Scopus, and EMBASE (Elsevier) databases was carried out to understand the nature of the extensive work done on the mechanistic role of Peroxisome proliferator activated receptor gamma and its modulation in Cerebral ischemic injury. PPAR-ɣ can interact with specific DNA response elements to control gene transcription and expression when triggered by its ligand. It regulates lipid metabolism, improves insulin sensitivity, modulates antitumor mechanisms, reduces oxidative stress, and inhibits inflammation. This review article provides insights on the current state of research into the neuroprotective effects of PPAR-ɣ in cerebral ischemic injury, as well as the cellular and molecular mechanisms by which these effects are modulated, such as inhibition of inflammation, reduction of oxidative stress, suppression of pro-apoptotic production, modulation of transcription factors, and restoration of injured tissue through neurogenesis and angiogenesis.

Maternal serum calprotectin level in intrahepatic cholestasis of pregnancy

AIM

This study aimed to investigate maternal serum levels of calprotectin in patients with intrahepatic cholestasis of pregnancy (ICP) and to compare these with serum calprotectin levels in healthy pregnant women.

METHODS

Ninety pregnant women (ICP group, n = 45; healthy control group, n = 45) were included in the study. The gestational age and body mass index of the participants in the two groups were similar. This prospective cross-sectional study was conducted between November 2019 and May 2020 in the perinatology department of University of Health Sciences Doctor Zekai Tahir Burak Women's Education Hospital, Ankara, Turkey. Patients were recruited from those attending the perinatology outpatient and inpatient clinics. Biochemical (alanine aminotransferase (ALT), aspartate transaminase (AST), lactate dehydrogenase (LDH), total bilirubin), fasting bile acid, hemogram, and calprotectin parameters of maternal blood were evaluated.

RESULTS

The mean fasting bile acid value in the ICP group was 30.3 ± 27.3 μmol, with severe ICP present in 11 (24.4%) patients. ALT, AST, LDH, total bilirubin, and mean platelet volume (MPV) values in the ICP group were higher and the red cell distribution width (RDW) value was lower than those in the control group (p < 0.001). The mean serum calprotectin levels in the control group and ICP group were 48.0 ± 10.4 and 765.4 ± 126.8 μg, respectively (p < 0.001). There was no significant correlation between serum fasting bile acid levels and serum calprotectin levels in the ICP group (p > 0.005).

CONCLUSION

Serum levels of calprotectin in patients with ICP were higher than those in healthy pregnant women. The serum calprotectin level may be an important diagnostic marker of ICP.

PFOS Inhibited Normal Functional Development of Placenta Cells via PPARγ Signaling

Perfluorooctane sulfonic acid (PFOS), a persistent environmental pollutant, has adverse effects on gestation pregnancy. Peroxisome proliferator-activated receptor γ (PPARγ) is involved in angiogenesis, metabolic processes, anti-inflammatory, and reproductive development. However, the function of PPARγ in PFOS evoked disadvantageous effects on the placenta remain uncertain. Here, we explored the role of PPARγ in PFOS-induced placental toxicity. Cell viability, cell migration, angiogenesis, and mRNA expression were monitored by CCK-8 assay, wound healing assay, tube formation assay, and real-time PCR, respectively. Activation and overexpression of PPARγ were conducted by rosiglitazone or pcDNA-PPARγ, and inhibition and knockdown of PPARγ were performed by GW9662 or si-PPARγ. Results revealed that PFOS decreased cell growth, migration, angiogenesis, and increased inflammation in human HTR-8/SVneo and JEG-3 cells. Placenta diameter and fetal weight decreased in mice treated with PFOS (12.5 mg/kg). In addition, rosiglitazone or pcDNA-PPARγ rescued cell proliferation, migration, angiogenesis, and decreased inflammation induced by PFOS in HTR8/SVneo and JEG-3 cells. Furthermore, GW9662 or si-PPARγ exacerbated the inhibition of cell viability, migration, angiogenesis, and aggravated inflammation induced by PFOS in HTR-8/SVneo and JEG-3 cells. Meanwhile, the results of mRNA expression level were consistent with the cell representation. In conclusion, our findings revealed that PFOS induced placenta cell toxicity and functional damage through PPARγ pathway.

Molecular Pathogenesis of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease. The maternal symptoms are characterized by skin pruritus and elevated bile acids, causing several adverse outcomes for fetuses, including an increased risk of preterm birth, meconium-stained amniotic fluid, neonatal depression, respiratory distress syndrome, and stillbirth. Genetic, hormonal, immunological, and environmental factors contribute to the pathogenesis of ICP, and the estrogen-bile acid axis is thought to play a dominant role. The advances in the past 10 years uncover more details of this axis. Moreover, dysregulation of extracellular matrix and oxygen supply, organelle dysfunction, and epigenetic changes are also found to cause ICP, illuminating more potential drug targets for interfering with. Here, we summarize the molecular pathogenesis of ICP with an emphasis on the advancement in the past 10 years, aiming to give an updated full view of this field.

SARS-CoV-2 Infection and Inflammatory Response in a Twin Pregnancy

There is growing literature about the SARS-CoV-2 pathogenetic effects exerted during pregnancy and whether vertical transmission or premature birth is possible. It is not well known whether changes in the immune system of pregnant women may lead to a marked susceptibility to infectious processes and the risk of adverse maternal and neonatal complications such as preterm birth, spontaneous abortion, hospitalization in an intensive care unit, transmission to the fetus or newborns, and fetal mortality are poorly understood. Along with this ongoing debate, it is not well defined whether, during pregnancy, the role of host susceptibility in producing a specific inflammatory response to SARS-CoV-2 may represent distinctive markers of risk of vertical transmission. Furthermore, SARS-CoV-2 impact on the vaginal microbiome has not yet been described, despite mounting evidence on its possible effect on the gastrointestinal microbiome and its influence on infectious diseases and preterm labor. This report describes the impact of SARS-CoV-2 on a twin pregnancy diagnosed with infection at the third trimester of gestation including tissue infections, inflammatory response, antibody production, cytokine concentration, and vaginal microbiome composition. We identified a pattern of cytokines including IL1-Ra, IL-9 G-CSF, IL-12, and IL-8 differently expressed, already associated with previously infected patients. We detected a similar concentration of almost all the cytokines tested in both twins, suggesting that the SARS-CoV-2-induced cytokine storm is not substantially impaired during the placental passage. The analysis of the vaginal microbiome did not show relevant signs of dysbiosis, similar to other healthy pregnant women and twin healthy pregnancies. The aim of this report was to analyze the immunological response against SARS-CoV-2 infection and virus tissue tropism in a twin pregnancy.

Role of Peroxisome Proliferator-Activated Receptors (PPARs) in Trophoblast Functions

Peroxisome proliferator-activated receptors (PPARα, PPARβ/δ, and PPARγ) belong to the transcription factor family, and they are highly expressed in all types of trophoblast during pregnancy. The present review discusses currently published papers that are related to the regulation of PPARs via lipid metabolism, glucose metabolism, and amino acid metabolism to affect trophoblast physiological conditions, including differentiation, maturation, secretion, fusion, proliferation, migration, and invasion. Recent pieces of evidence have proven that the dysfunctions of PPARs in trophoblast lead to several related pregnancy diseases such as recurrent miscarriage, preeclampsia, intrauterine growth restriction, and gestational diabetes mellitus. Moreover, the underlying mechanisms of PPARs in the control of these processes have been discussed as well. Finally, this review's purposes are to provide more knowledge about the role of PPARs in normal and disturbed pregnancy with trophoblast, so as to find PPAR ligands as a potential therapeutic target in the treatment and prevention of adverse pregnancy outcomes.

The Role of NFκB in Healthy and Preeclamptic Placenta: Trophoblasts in the Spotlight

The NFκB protein family regulates numerous pathways within the cell-including inflammation, hypoxia, angiogenesis and oxidative stress-all of which are implicated in placental development. The placenta is a critical organ that develops during pregnancy that primarily functions to supply and transport the nutrients required for fetal growth and development. Abnormal placental development can be observed in numerous disorders during pregnancy, including fetal growth restriction, miscarriage, and preeclampsia (PE). NFκB is highly expressed in the placentas of women with PE, however its contributions to the syndrome are not fully understood. In this review we discuss the molecular actions and related pathways of NFκB in the placenta and highlight areas of research that need attention.

Inflammatory marker YKL-40 levels in intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy is a diagnosis of exclusion and presents with unexplained pruritus, abnormal liver function tests, and increased serum bile acid levels, particularly in the third trimester of pregnancy. Serum YKL-40 levels are increased in liver diseases and our aim was to investigate YKL-40 levels in pregnant women with ICP. 40 women with intrahepatic cholestasis of pregnancy and 40 healthy pregnant women were included in this cross-sectional study. Serum YKL-40 levels were measured in both groups and correlation analysis were performed between the YKL-40 and other liver function tests. Serum YKL-40 concentrations were higher in the intrahepatic cholestasis of pregnancy group than in the control group (103.46 ± 53.03 vs. 57.60 ± 30.30 ng/ml, p = .002). The cutoff YKL-40 serum concentration was 84.80 ng/ml for the diagnosis of intrahepatic cholestasis of pregnancy. There was no correlation between fasting bile acids and YKL-40 levels. However, there was a significant positive correlation between the YKL-40 levels and aspartate aminotransferase (r = 0.22, p = .04) and alanine aminotransferase (r = 0.24, p = .02). Raised YKL-40 levels might support the evidence on inflammatory processes in intrahepatic cholestasis of pregnancy.

A Short-Term High-Fat Diet Alters Glutathione Levels and IL-6 Gene Expression in Oxidative Skeletal Muscles of Young Rats

Obesity and ensuing disorders are increasingly prevalent worldwide. High-fat diets (HFD) and diet-induced obesity have been shown to induce oxidative stress and inflammation while altering metabolic homeostasis in many organs, including the skeletal muscle. We previously observed that 14 days of HFD impairs contractile functions of the soleus (SOL) oxidative skeletal muscle. However, the mechanisms underlying these effects are not clarified. In order to determine the effects of a short-term HFD on skeletal muscle glutathione metabolism, young male Wistar rats (100–125 g) were fed HFD or a regular chow diet (RCD) for 14 days. Reduced (GSH) and disulfide (GSSG) glutathione levels were measured in the SOL. The expression of genes involved in the regulation of glutathione metabolism, oxidative stress, antioxidant defense and inflammation were measured by RNA-Seq. We observed a significant 25% decrease of GSH levels in the SOL muscle. Levels of GSSG and the GSH:GSSG ratio were similar in both groups. Further, we observed a 4.5 fold increase in the expression of pro-inflammatory cytokine interleukin 6 (IL-6) but not of other cytokines or markers of inflammation and oxidative stress. We hereby demonstrate that a short-term HFD significantly lowers SOL muscle GSH levels. This effect could be mediated through the increased expression of IL-6. Further, the skeletal muscle antioxidant defense could be impaired under cellular stress. We surmise that these early alterations could contribute to HFD-induced insulin resistance observed in longer protocols.

Curcumin Attenuates Asthmatic Airway Inflammation and Mucus Hypersecretion Involving a PPARγ-Dependent NF-κB Signaling Pathway In Vivo and In Vitro

Asthma is characterized by airway inflammation and mucus hypersecretion. Curcumin possessed a potent anti-inflammatory property involved in the PPARγ-dependent NF-κB signaling pathway. Then, the aim of the current study was to explore the value of curcumin in asthmatic airway inflammation and mucus secretion and its underlying mechanism. In vivo, mice were sensitized and challenged by ovalbumin (OVA) to induce chronic asthma. Airway inflammation and mucus secretion were analyzed. In vitro, BEAS-2B cells were obtained. MCP-1, MUC5AC, and PPARγ expression and the phosphorylation of NF-κB p65 and NF-κB p65 DNA-binding activity were measured in both the lungs and BEAS-2B cells. shRNA-PPARγ was used to knock down PPARγ expression. We found that OVA-induced airway inflammation and mucus hypersecretion in mice, OVA and IL-4-induced upregulation of MCP-1 and MUC5AC, suppression of PPARγ, and activation and translocation of NF-κB p65 were notably improved by curcumin both in vivo and in vitro. Our data also showed that these effects of curcumin were significantly abrogated by shRNA-PPARγ. Taken together, our results indicate that curcumin attenuated OVA-induced airway inflammation and mucus hypersecretion in mice and suppressed OVA- and IL-4-induced upregulation of MCP-1 and MUC5AC both in vivo and in vitro, most likely through a PPARγ-dependent NF-κB signaling pathway.

Association of adverse perinatal outcomes of intrahepatic cholestasis of pregnancy with biochemical markers: results of aggregate and individual patient data meta-analyses

BACKGROUND

Intrahepatic cholestasis of pregnancy is associated with adverse perinatal outcomes, but the association with the concentration of specific biochemical markers is unclear. We aimed to quantify the adverse perinatal effects of intrahepatic cholestasis of pregnancy in women with increased serum bile acid concentrations and determine whether elevated bile acid concentrations were associated with the risk of stillbirth and preterm birth.

METHODS

We did a systematic review by searching PubMed, Web of Science, and Embase databases for studies published from database inception to June 1, 2018, reporting perinatal outcomes for women with intrahepatic cholestasis of pregnancy when serum bile acid concentrations were available. Inclusion criteria were studies defining intrahepatic cholestasis of pregnancy based upon pruritus and elevated serum bile acid concentrations, with or without raised liver aminotransferase concentrations. Eligible studies were case-control, cohort, and population-based studies, and randomised controlled trials, with at least 30 participants, and that reported bile acid concentrations and perinatal outcomes. Studies at potential higher risk of reporter bias were excluded, including case reports, studies not comprising cohorts, or successive cases seen in a unit; we also excluded studies with high risk of bias from groups selected (eg, a subgroup of babies with poor outcomes were explicitly excluded), conference abstracts, and Letters to the Editor without clear peer review. We also included unpublished data from two UK hospitals. We did a random effects meta-analysis to determine risk of adverse perinatal outcomes. Aggregate data for maternal and perinatal outcomes were extracted from case-control studies, and individual patient data (IPD) were requested from study authors for all types of study (as no control group was required for the IPD analysis) to assess associations between biochemical markers and adverse outcomes using logistic and stepwise logistic regression. This study is registered with PROSPERO, number CRD42017069134.

FINDINGS

We assessed 109 full-text articles, of which 23 studies were eligible for the aggregate data meta-analysis (5557 intrahepatic cholestasis of pregnancy cases and 165 136 controls), and 27 provided IPD (5269 intrahepatic cholestasis of pregnancy cases). Stillbirth occurred in 45 (0·83%) of 4936 intrahepatic cholestasis of pregnancy cases and 519 (0·32%) of 163 947 control pregnancies (odds ratio [OR] 1·46 [95% CI 0·73-2·89]; I2=59·8%). In singleton pregnancies, stillbirth was associated with maximum total bile acid concentration (area under the receiver operating characteristic curve [ROC AUC]) 0·83 [95% CI 0·74-0·92]), but not alanine aminotransferase (ROC AUC 0·46 [0·35-0·57]). For singleton pregnancies, the prevalence of stillbirth was three (0·13%; 95% CI 0·02-0·38) of 2310 intrahepatic cholestasis of pregnancy cases in women with serum total bile acids of less than 40 μmol/L versus four (0·28%; 0·08-0·72) of 1412 cases with total bile acids of 40-99 μmol/L (hazard ratio [HR] 2·35 [95% CI 0·52-10·50]; p=0·26), and versus 18 (3·44%; 2·05-5·37) of 524 cases for bile acids of 100 μmol/L or more (HR 30·50 [8·83-105·30]; p<0·0001).

INTERPRETATION

The risk of stillbirth is increased in women with intrahepatic cholestasis of pregnancy and singleton pregnancies when serum bile acids concentrations are of 100 μmol/L or more. Because most women with intrahepatic cholestasis of pregnancy have bile acids below this concentration, they can probably be reassured that the risk of stillbirth is similar to that of pregnant women in the general population, provided repeat bile acid testing is done until delivery.

FUNDING

Tommy's, ICP Support, UK National Institute of Health Research, Wellcome Trust, and Genesis Research Trust.

The role of metabolic disorders in the pathogenesis of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disorder which typically commences in the late second or third trimester and resolves within 48 hours after delivery. It is characterized by mild to severe pruritus, without any specific dermatologic features, elevated liver enzymes and increased serum bile acids (BA). The etiology of ICP is still not completely explicit. Pathogenesis includes a combination of hormonal and environmental factors superimposing on a genetic predisposition. During recent years increasingly ICP is recognized to be associated with an abnormal metabolic profile, including glucose intolerance and dyslipidemia, although it is considered to be secondary to maternal aberrant BA homeostasis. This article reviews the recent literature data and current concepts for ICP, with emphasis on a possibility of metabolic disorders being primary causative factors in ICP pathogenesis.

Resveratrol regulates the silent information regulator 1-nuclear factor-κB signaling pathway in intrahepatic cholestasis of pregnancy

AIM

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease characterized by raised serum bile acids and adverse fetal outcomes. In this study, we aimed to explore the molecular and biochemical mechanism of resveratrol in regulating the silent information regulator 1-nuclear factor-κB (SIRT1-NF-κB) signaling pathway and bile acid biosynthesis in ICP.

METHODS

We analyzed serum and placenta samples from 30 normal and ICP pregnancy women. Then we treated HTR-8/SVneo cells with taurocholic acid (TCA) to mimic ICP conditions before treating these cells with resveratrol, as an activator of SIRT1, and EX-57, as an inhibitor of SIRT1. We established an ICP rat model to analyze the therapeutic effect of resveratrol.

RESULTS

The expression of SIRT1 protein was higher in normal placenta tissues than in ICP, and the expression of NF-κB was lower in the normal group than in the ICP group. We found that SIRT1 was downregulated, whereas NF-κB and tuor necrosis factor-α (TNF-α) were upregulated, in syncytiotrophoblast HTR-8 cells treated with TCA. This phenomenon could be reversed by resveratrol, and these effects could be blocked by Ex-527.

CONCLUSION

These data indicate that resveratrol might protect syncytiotrophoblast against TCA-induced inflammatory injury by upregulation of SIRT1 and downregulation of NF-κB and TNF-α. Resveratrol could be a potential therapeutic target for ICP.

Paeonia lactiflora Pall. regulates the NF-κB-NLRP3 inflammasome pathway to alleviate cholestasis in rats

OBJECTIVES

Cholestasis is a critical risk factor for severe hepatic disease or cirrhosis. The anti-inflammatory effect of Paeonia lactiflora Pall. (PLP), named Chishao in traditional Chinese medicine (TCM), on alpha-naphthylisothiocyanate (ANIT)-induced cholestasis model was tried to be elucidated in this research.

METHODS

Therapeutic effect indices on hepatic function, including ALT, AST, TBIL, DBIL, ALP, TBA and γ-GT, were measured. To further investigate the protective mechanism of PLP, the mRNA and protein expression levels of NF-κB-NLRP3 inflammasome pathway were detected.

RESULTS

Our results showed that compared with the model group, PLP could significantly reduce the increased serum indices such as ALT, AST, TBIL, DBIL, ALP, TBA and γ-GT induced by ANIT in a dose-dependent way. Moreover, we found that PLP downregulated the mRNA expression levels including IKK, p65, NLRP3, caspase-1 and IL-1β, especially at the large dose. Furthermore, PLP also significantly inhibited NF-κB-NLRP3 inflammasome pathway by decreasing the protein levels of p65, p-p65, p-IKK, NLRP3, caspase-1 and IL-1β.

CONCLUSIONS

The results indicated that PLP could ameliorate ANIT-induced cholestasis in rats and the anti-inflammatory effect of PLP might be related to regulating NF-κB-NLRP3 inflammasome pathway. This study will provide scientific evidence for PLP as a potential drug candidate for cholestasis.

Magnesium sulphate can alleviate oxidative stress and reduce inflammatory cytokines in rat placenta of intrahepatic cholestasis of pregnancy model

PURPOSE

In our study, we try to investigate whether magnesium sulphate (MgSO₄) could provide protection against oxidative damage and inflammatory response in rat placenta of intrahepatic cholestasis of pregnancy (ICP) model.

METHODS

The rat model of ICP was established by injecting s.c. 17α-ethinyl estradiol (EE) daily for 5 days. MgSO₄, as an therapeutic drug for ICP, was injected i.p. daily for 3 days. Age-matched pregnant rats served as controls. The level of serum total bile acid (TBA) was measured. The data including the number and weight of offsprings on day 20 of pregnancy were collected. We observed ultrastructural changes of mitochondria and endoplasmic reticulum (ER) in placenta by transmission electron microscope. The antioxidant proteins peroxiredoxin-6 (Prdx6) and nuclear factor erythroid 2-related factor-2 (Nrf2) were analyzed by Western Blot. The inflammatory cytokines including IL-1β, TNF-α and IFN-γ were investigated by real-time PCR (RT-PCR) and enzyme-linked immune-sorbent assay (ELISA).

RESULTS

The weight of offsprings on day 20 of pregnancy increased in ICP rats treated with MgSO₄ (ICP + MG group) compared with that in ICP rats (ICP group). However, the level of TBA was not reduced. The damage of mitochondria and ER was observed in placenta, which was much more slighter in ICP + MgSO₄ group as compared with that in ICP group. Prdx6 and Nrf2 were increased, while the inflammatory cytokines including IL-1β, TNF-α and IFN-γ were decreased in ICP + MgSO₄ group compared with that in ICP group.

CONCLUSIONS

MgSO₄ had beneficial effect on improving growth of offsprings in rat model of ICP. The protective effect of MgSO₄ on alleviating oxidative damage and inflammatory response in placenta may play an important role in the process. MgSO₄ may improve the function of placenta.

Decreased blood pressure is related to changes in NF-kB promoter methylation levels after bariatric surgery

BACKGROUND

Obesity is characterized by a chronic, low-grade inflammation, and bariatric surgery is proposed as an effective treatment for reducing the obesity-related co-morbidities. Epigenetic modifications could be involved in the metabolic improvement after surgery.

OBJECTIVE

The main aim of this study was to evaluate whether DNA methylation pattern from genes related to inflammation and insulin response is associated with the metabolic improvement after bariatric surgery in morbidly obese patients and if these changes depend on the surgical procedure.

SETTING

University hospital, Spain.

METHODS

We studied 60 severely obese patients; 31 underwent Roux-en-Y gastric bypass and 29 underwent laparoscopic sleeve gastrectomy. All patients were examined before and at 6 months after bariatric surgery. DNA methylation profile of genes related to the inflammatory response and insulin sensitivity was measured by pyrosequencing.

RESULTS

The promoter methylation levels of the NFKB1 gene were increased significantly after surgery (2.16 ± .9 versus 2.8 ± 1.03). The decrease in blood pressure, both systolic and diastolic, after surgery was significantly associated with the changes in the promoter methylation levels of the NFKB1 gene (β = -.513, P = .003 and β = -.543, P = .004, respectively). A decrease in inflammation status, measured by high sensitivity C-reactive protein values, was associated with changes in SLC19A1 methylation levels.

CONCLUSION

Our study shows for the first time an association between NFKB1 methylation levels and blood pressure after bariatric surgery, highlighting the possible function of this gene in the regulation of arterial pressure. Regarding SLC19A1, this gene could position as a potential target linking inflammation and insulin resistance.

[Role of endoplasmic reticulum stress-induced apoptosis of trophoblasts in intrahepatic cholestasis during pregnancy]

OBJECTIVE

To investigate the role of endoplasmic reticulum stress (ERS)-induced trophoblast apoptosis in the development of intrahepatic cholestasis during pregnancy (ICP).

METHODS

Twenty pregnant women with ICP and 20 normal pregnant women undergoing cesarean section were enrolled in this study. The number of placenta syncytial knots in these women was determined using HE staining. The mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 were detected using RT-PCR in the placental tissues of the women and also in HTR-8/SVneo cells treated with different doses of deoxycholic acid (DCA). Caspase-3 and caspase-7 activities were also detected in DCA-treated HTR-8/SVneo cells using commercial assay kits, and the presence of apoptotic bodies in the cells were detected with electron microscopy.

RESULTS

Compared with normal placental tissues, the placenta from women with ICP showed significantly increased syncytial knots (P<0.01) and obviously enhanced mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 (P<0.05). In HTR-8/SVneo cells treated with different doses of DCA (0, 10, 50, and 100 µmol/L), the mRNA expressions of GRP78, CHOP, caspase-3 and caspase-7 were significantly increased in a dose-dependent manner (P<0.05) and the protein levels of GRP78 and CHOP were also increased dose-dependently. Treatment with DCA at 50 µmol/L for 24 h significantly upregulated caspase-3 and caspase-7 activity in the cells (P<0.05), and the cells treated with 50 µmol/L DCA for 12 h showed the presence of apoptotic bodies.

CONCLUSION

The activation of ERS and enhanced apoptosis of the trophoblasts occur in the placenta of women with ICP. DCA can significantly increase the expressions of ERS markers and thus lead to trophoblast apoptosis, suggesting that ERS-induced trophoblasts apoptosis may play a key role in the development of ICP.

[Role of endoplasmic reticulum stress-induced apoptosis of trophoblasts in intrahepatic cholestasis during pregnancy]

OBJECTIVE

To investigate the role of endoplasmic reticulum stress (ERS)-induced trophoblast apoptosis in the development of intrahepatic cholestasis during pregnancy (ICP).

METHODS

Twenty pregnant women with ICP and 20 normal pregnant women undergoing cesarean section were enrolled in this study. The number of placenta syncytial knots in these women was determined using HE staining. The mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 were detected using RT-PCR in the placental tissues of the women and also in HTR-8/SVneo cells treated with different doses of deoxycholic acid (DCA). Caspase-3 and caspase-7 activities were also detected in DCA-treated HTR-8/SVneo cells using commercial assay kits, and the presence of apoptotic bodies in the cells were detected with electron microscopy.

RESULTS

Compared with normal placental tissues, the placenta from women with ICP showed significantly increased syncytial knots (P<0.01) and obviously enhanced mRNA expressions of GRP78, CHOP, caspase-3, and caspase-7 (P<0.05). In HTR-8/SVneo cells treated with different doses of DCA (0, 10, 50, and 100 µmol/L), the mRNA expressions of GRP78, CHOP, caspase-3 and caspase-7 were significantly increased in a dose-dependent manner (P<0.05) and the protein levels of GRP78 and CHOP were also increased dose-dependently. Treatment with DCA at 50 µmol/L for 24 h significantly upregulated caspase-3 and caspase-7 activity in the cells (P<0.05), and the cells treated with 50 µmol/L DCA for 12 h showed the presence of apoptotic bodies.

CONCLUSION

The activation of ERS and enhanced apoptosis of the trophoblasts occur in the placenta of women with ICP. DCA can significantly increase the expressions of ERS markers and thus lead to trophoblast apoptosis, suggesting that ERS-induced trophoblasts apoptosis may play a key role in the development of ICP.

Nonenzymatic glycation interferes with fibronectin-integrin interactions in vascular smooth muscle cells

OBJECTIVE

We aimed to investigate whether advanced nonenzymatic glycation of the ECM protein, fibronectin, impacts its normal integrin-mediated interaction with arteriolar VSMC.

METHODS

AFM was performed on cultured VSMC from rat cremaster arterioles to study native and glycated fibronectin (FN and gFN) interactions with cellular integrins. AFM probes were functionalized with FN or gFN or with native or glycated albumin (gAlb) as controls.

RESULTS

VSMC showed increased adhesion probability to gFN (72.9±3.5%) compared with native FN (63.0±1.6%). VSMC similarly showed increased probability of adhesion (63.8±1.7%) to gAlb compared with native Alb (40.1±4.7%). Adhesion of native FN to VSMC was α5 and β1 integrin dependent whereas adhesion of gFN to VSMC was integrin independent. The RAGE-selective inhibitor, FPS-ZM1, blocked gFN (and gAlb) adhesion, suggesting that adhesion of glycated proteins was RAGE dependent. Interaction of FN with VSMC was not altered by soluble gFN while soluble native FN did not inhibit adhesion of gFN to VSMC. In contrast, gAlb inhibited adhesion of gFN to VSMC in a concentration-dependent manner.

CONCLUSIONS

Glycation of FN shifts the nature of cellular adhesion from integrin- to RAGE-dependent mechanisms.

Pregnancy and bile acid disorders

During pregnancy, extensive adaptations in maternal metabolic and immunological physiology occur. Consequently, preexisting disease may be exacerbated or attenuated, and new disease susceptibility may be unmasked. Cholestatic diseases, characterized by a supraphysiological raise in bile acid levels, require careful monitoring during pregnancy. This review describes the latest advances in the knowledge of intrahepatic cholestasis of pregnancy (ICP), the most common bile acid disorder specific to pregnancy, with a focus on the disease etiology and potential mechanisms of ICP-associated adverse pregnancy outcomes, including fetal demise. The course of preexisting cholestatic conditions in pregnancy is considered, including primary sclerosing cholangitis, primary biliary cholangitis, biliary atresia, and Alagille syndrome. The currently accepted treatments for cholestasis in pregnancy and promising new therapeutics for the condition are described.

Bile acids and gestation

There are numerous profound maternal physiological changes that occur from conception onwards and adapt throughout gestation in order to support a healthy pregnancy. By the time of late gestation, when circulating pregnancy hormones are at their highest concentrations, maternal adaptations include relative hyperlipidemia, hypercholanemia and insulin resistance. Bile acids have now been established as key regulators of metabolism, and their role in gestational changes in metabolism is becoming apparent. Bile acid homeostasis is tightly regulated by the nuclear receptor FXR, which has been shown to have reduced activity during pregnancy. This review focuses on the gestational alterations in bile acid homeostasis that occur in normal pregnancy, which in some women can become pathological, leading to the development of intrahepatic cholestasis of pregnancy. As well as their important role in maternal metabolic health, we will review bile acid metabolism in the feto-placental unit.

Immunology of hepatic diseases during pregnancy

The mother's immune system has to adapt to pregnancy accepting the semi-allograft fetus and preventing harmful effects to the developing child. Aberrations in feto-maternal immune adaptation may result in disease of the mother, such as liver injury. Five pregnancy-associated liver disorders have been described so far, however, little is known concerning immune alterations promoting the respective disease. These liver disorders are pre-eclampsia, hemolysis, elevated liver enzymes, low platelet count (HELLP), acute fatty liver, hyperemesis gravidarum, and intrahepatic cholestasis of pregnancy. On the other hand, pre-existing autoimmune liver injury of the mother can be affected by pregnancy. This review intends to summarize current knowledge linking feto-maternal immunology and liver inflammation with a special emphasis on novel potential biomarkers.

The peroxisome proliferator-activated receptors under epigenetic control in placental metabolism and fetal development

The placental metabolism can adapt to the environment throughout pregnancy to both the demands of the fetus and the signals from the mother. Such adaption processes include epigenetic mechanisms, which alter gene expression and may influence the offspring's health. These mechanisms are linked to the diversity of prenatal environmental exposures, including maternal under- or overnutrition or gestational diabetes. The peroxisome proliferator-activated receptors (PPARs) are nuclear receptors that contribute to the developmental plasticity of the placenta by regulating lipid and glucose metabolism pathways, including lipogenesis, steroidogenesis, glucose transporters, and placental signaling pathways, thus representing a link between energy metabolism and reproduction. Among the PPAR isoforms, PPARγ appears to be the main modulator of mammalian placentation. Certain fatty acids and lipid-derived moieties are the natural activating PPAR ligands. By controlling the amounts of maternal nutrients that go across to the fetus, the PPARs play an important regulatory role in placenta metabolism, thereby adapting to the maternal nutritional status. As demonstrated in animal studies, maternal nutrition during gestation can exert long-term influences on the PPAR methylation pattern in offspring organs. This review underlines the current state of knowledge on the relationship between environmental factors and the epigenetic regulation of the PPARs in placenta metabolism and offspring development.

The pathophysiology of intrahepatic cholestasis of pregnancy

A number of liver disorders are specific to pregnancy. Amongst these, intrahepatic cholestasis of pregnancy (ICP), also known as obstetric cholestasis (OC), is the commonest, affecting approximately 1 in 140 UK pregnancies. Patients commonly present in the third trimester with severe pruritus and deranged serum liver tests; bile acids are elevated, in severe cases >40 μmol/L. Although the disease is considered relatively benign for the mother, increased rates of adverse fetal outcomes, including stillbirth, are associated with ICP. As our knowledge of the mechanisms underlying bile acid homeostasis has advanced in the last 15 years our understanding of ICP has grown, in particular with respect to genetic influences on susceptibility to the disease, the role of reproductive hormones and their metabolites and the possible identity of the pruritic agents. In this review, we will describe recent advances in the understanding of this condition with a particular emphasis on how aspects of genetic and reproductive hormone involvement in pathophysiology have been elucidated. We also review recent developments regarding our knowledge of placental and fetal pathophysiology and the long-term health consequences for the mother and child.

Immunological basis in the pathogenesis of intrahepatic cholestasis of pregnancy

Intrahepatic cholestasis of pregnancy poses a great risk to both maternal and fetal health. Despite extensive research, much of the pathogenesis of this disorder is unknown. The increase in bile acids observed in patients with intrahepatic cholestasis of pregnancy has been noted to cause a change in the immune system from the normally mediated TH2 response to one that is more oriented towards TH1. In this literature review, we have critically reviewed the current literature regarding the changes in the immune system and the potential effects of immunological changes in the management of the patient. The current treatment, ursodeoxycholic acid, is also discussed along with potential combination therapies and future directions for research.

Effect of the maternal-fetal interface immunoregulation on the occurrence of intrahepatic cholestasis of pregnancy

Maternal immune tolerance of the fetus is indispensable for a healthy pregnancy. Currently, the study of the immune microenvironment of the maternal-fetal interface has been a heated topic in reproductive immunology research. More and more studies show that the immune imbalance in the maternal-fetal interface plays a very important role in the incidence of intrahepatic cholestasis of pregnancy (ICP). However, the precise etiology and mechanism of immune imbalance in the occurrence of ICP is still unknown. In order to clarify the potential immunologic mechanisms of ICP, this review summarizes the recent studies of the decidual immunology microenvironment and the potential immunologic mechanisms related to the development of ICP.

Intrahepatic cholestasis of pregnancy

Itching is commonly reported by pregnant women and may be due to physiologic changes of pregnancy or could indicate a more serious health concern. Intrahepatic cholestasis of pregnancy, while classified as a pregnancy dermatosis, is actually a liver disease of pregnancy associated with significant fetal mortality and morbidity, as well as lifelong health risks for the offspring. In these challenging cases, nurses must understand the differential diagnoses and be prepared to provide comprehensive care, education and support to women with this condition. A case example is included.