Procyanidin B2 ameliorates endothelial dysfunction and impaired angiogenesis via the Nrf2/PPARγ/sFlt-1 axis in preeclampsia

Epicatechin prevents preeclampsia-associated hypertension and oxidative stress

Preeclampsia (PE) is a frequent and dangerous multisystemic pregnancy complication, associated with blood pressure control. Some antioxidants, including chocolate-derived epicatechin, can effectively attenuate hypertensive disorders.

AIM

This study aimed to assess whether epicatechin or dark chocolate (DC) could revert vascular increased reactivity and oxidative stress, both features of an experimental PE model.

METHODS

Rats from healthy pregnant or PE groups received vehicle, epicatechin (10 mg/kg/day) po, or DC (1 g) po, administered on days 1-14 (early) or days 7-21(late) of pregnancy. Blood pressure was measured by the tail-cuff plethysmography method. Aorta contractility was evaluated using a conventional isolated organ bath, and oxidative stress was determined by nicotine adenine dinucleotide phosphate reduced (NADPH) serum activity.

RESULTS

Epicatechin and DC significantly reduced hypertension, decreased abdominal aorta contractility, and decreased NADPH activity of the PE animals. The effects were more evident when administered during the last 2 weeks of pregnancy.

CONCLUSIONS

Results suggest that epicatechin has a significant antihypertensive effect in PE mediated by an antioxidant activity that improves vascular contractility.

NFĸB and its inhibitors in preeclampsia: mechanisms and potential interventions

Preeclampsia (PE), which affects between 2 and 15% of pregnancies, is one of the most often reported prenatal problems. It is defined as gestational hypertension beyond 20 weeks of pregnancy, along with widespread edema or proteinuria and specific types of organ damage. PE is characterized by increased levels and activation of nuclear factor kappa B (NF-κB) in the mother's blood and placental cells. This factor controls over 400 genes linked to inflammatory, apoptotic, angiogenesis, and cellular responses to hypoxia and oxidative stress. In the final stages of physiological pregnancy, NF-κB levels need to be lowered to favor maternal immunosuppressive events and continue gestation to prevent hypoxia and inflammation, which are advantageous for implantation. Pharmacotherapy is thought to be a potential treatment for PE by downregulating NF-κB activation. NF-κB activity has been discovered to be regulated by several medications used for both prevention and treatment of PE. However, in order to guarantee treatment safety and effectiveness, additional creativity is desperately required. This article provides an overview of the current understanding of the defined function of NF-κB in PE progression. According to their effect on the cellular control of NF-κB pathways, newly proposed compounds for preventing and treating PE have also been emphasized.

Bioactive Flavonoids in Protecting Against Endothelial Dysfunction and Atherosclerosis

Atherosclerosis is a common cardiovascular disease closely associated with factors such as hyperlipidaemia and chronic inflammation. Among them, endothelial dysfunction serves as a major predisposing factor. Vascular endothelial dysfunction is manifested by impaired endothelium-dependent vasodilation, enhanced oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, endothelial senescence, and endothelial-mesenchymal transition (EndoMT). Flavonoids are known for their antioxidant activity, eliminating oxidative stress induced by reactive oxygen species (ROS), thereby preventing the oxidation of low-density lipoprotein (LDL) cholesterol, reducing platelet aggregation, alleviating ischemic damage, and improving vascular function. Flavonoids have also been shown to possess anti-inflammatory activity and to protect the cardiovascular system. This review focuses on the protective effects of these naturally-occuring bioactive flavonoids against the initiation and progression of atherosclerosis through their effects on endothelial cells including, but not limited to, their antioxidant, anti-inflammatory, anti-thrombotic, and lipid-lowering properties. However, more clinical evidences are still needed to determine the exact role and optimal dosage of these compounds in the treatment of atherosclerosis.

Echinacoside activates Nrf2/PPARγ signaling pathway to modulate mitochondrial fusion-fission balance to ameliorate ox-LDL-induced dysfunction of coronary artery endothelial cells

As a cardiovascular disease, coronary heart disease (CHD) is characterized by poor prognosis and increasing morbidity and mortality rates. Echinacoside (ECH) can protect against multiple cardiovascular diseases due to its antioxidant and anti-inflammatory properties. However, the role of ECH in CHD remains unclear. In ECH-treated human coronary artery endothelial cells (HCAECs), cell viability, NO production, endothelial nitric oxide synthase (eNOS) expression, and angiogenesis ability were detected using cell counting kit-8 (CCK-8) assay, diaminofluorescein-FM diacetate (DAF-FM DA) staining, western blot, and tube formation assay, respectively. The activities of oxidative stress markers were detected using dichloro-dihydro-fluorescein diacetate (DCFH-DA) assay and corresponding assay kits. Cell apoptosis was detected utilizing flow cytometry and caspase3 assay. Western blot was used to detect the expressions of Nrf2/PPARγ signaling pathway- and mitochondrial dynamics-related proteins. Mitochondrial membrane potential and mitochondrial fusion and fission were detected using JC-1 staining and immunofluorescence (IF) assay. In this study, ECH was found to revive the viability, ameliorate the endothelial dysfunction, suppress oxidative stress, and inhibit the apoptosis in ox-LDL-induced HCAECs via activating Nrf2/PPARγ signaling pathway, which were all abolished following the treatment of Nrf2 inhibitor ML385. It was also identified that ECH regulated mitochondrial fusion-fission balance in ox-LDL-induced HCAECs through the activation of Nrf2/PPARγ signaling pathway. In summary, ECH activated Nrf2/PPARγ signaling pathway to regulate mitochondrial fusion-fission balance, thereby improving ox-LDL-induced dysfunction of HCAECs.

Self-assembled Abietic acid encapsulated nanoparticles to improve the stability of Proanthocyanin B2

Procyanidin B2 (Pac B2) has attracted much attention due to its strong antioxidant activity, but poor in vivo stability limits its wide application in food and medicine. In this paper, composite nanoparticles (NPs) were constructed using abietic acid (AA) as a carrier, which significantly enhanced Pac B2 stability. A spherical morphology and average diameter of 396.05 nm were observed in AA-Pac B2 NPs synthesized by solvent co-precipitation. Pac B2 encapsulation was 11.28 %, and thermal stability is improved. Infrared, Ultraviolet spectrum, and MD (molecular dynamics) spectroscopy revealed hydrogen bonding and hydrophobic interaction between AA and Pac B2. For up to 2 h at 37 °C, Pac B2 can be sustainably released in simulated gastric and intestinal fluids. In vitro, AA-Pac B2 NPs at the same concentration exhibited higher bioavailability and uptake efficiency than free Pac B2. The data demonstrate the potential of AA NPs for improving polyphenol thermal stability and bioavailability.

Litchi Procyanidins Ameliorate DSS-Induced Colitis through Gut Microbiota-Dependent Regulation of Treg/Th17 Balance

Ulcerative colitis (UC) is a common chronic, relapsing inflammatory bowel condition. Procyanidins (PC) are known for their antiangiogenic, anti-inflammatory, antioxidant, and antimetastatic properties. However, there is comparatively limited information on how PC interacts with UC. In this study, 5 mg/10 mL/kg body weight of PC was administered to mice with dextran sulfate sodium (DSS)-induced colitis mice. PC treatment prolonged the survival period of mice, ameliorated UC symptoms, reduced damage to the intestinal mucosal barrier, and increased the protein expression of ZO-1 and occludin in the DSS-treated mice. Importantly, PC treatment significantly reduced gene expression related to Th17 cell differentiation, including STAT3, SMAD3, TGF-β, and JAK1. The results of the flow cytometry analysis indicated significant increase in the number of Treg cells and a concomitant decrease in the proportion of Th17 cells in the colon following PC treatment. Additionally, PC increased the abundance of gut microbiota such as Bacteroidota, Oscillospiraceae, Muribaculaceae, and Desulfovibrionaceae, as well as the concentrations of acetate acid, propionate acid, and butyrate acid in the feces. PC also activated short-chain fatty acid receptors, such as G-protein coupled receptor 43 in the colon, which promoted the proliferation of Treg cells. The depletion of gut microbiota and subsequent transplantation of fecal microbiota demonstrated that PC's effects on gut microbiota were effective in improving UC and restoring intestinal Th17/Treg homeostasis in a microbiota-dependent manner. This suggests that PC could be a promising functional food for the prevention and treatment of UC in the future.

GPER Stimulation Attenuates Cardiac Dysfunction in a Rat Model of Preeclampsia

BACKGROUND

Preeclampsia poses a substantial clinical challenge, characterized by maternal hypertension, cardiac dysfunction, and persistent cardiovascular risks for both the mother and offspring. Despite the known roles of the estrogen receptor (GPER [G protein-coupled estrogen receptor]) in placental development, its impact on cardiovascular aspects within a preeclampsia animal model remains unexplored. We propose that G-1, a GPER agonist, could have the potential to regulate not only hypertension but also cardiac dysfunction in rats with preeclampsia.

METHODS

To explore the influence of G-1 on preeclampsia, we used the reduced uterine perfusion pressure (RUPP) model. RUPP rats were administered either G-1 (100 µg/kg per day) or hydralazine (25 mg/kg per day). We conducted echocardiography to probe the intricate cardiac effects of G-1.

RESULTS

The RUPP rat model revealed signs of hypertension and cardiac dysfunction and alterations in gene and protein expression within placental and heart tissues. G-1 treatment reduced blood pressure and reversed cardiac dysfunction in rats with preeclampsia. In contrast, administration of the vasodilator hydralazine reduced blood pressure without an improvement in cardiac function. In addition, while G-1 treatment restored the levels of sFLT-1 (soluble fms-like tyrosine kinase-1) in RUPP rats, hydralazine did not normalize this antiangiogenic factor.

CONCLUSIONS

The therapeutic intervention of G-1 significantly mitigated the cardiovascular dysfunction observed in the RUPP rat model of preeclampsia. This discovery underscores the broader significance of understanding GPER's role in the context of preeclampsia-related cardiovascular complications.

Eucommia ulmoidesOliv. leaves flavonoids attenuate methylglyoxal-induced endothelial cell apoptosis in vitro and in vivo by upregulating AKT-Nrf2 signaling and downregulating oxidative stress

Methylglyoxal (MGO) triggers oxidative stress responses in vascular endothelial cells, leading to apoptosis linked to diabetic vascular complications. Total flavonoids of Eucommia ulmoides leaves (TFEL) display antioxidant activity, yet its prevention of MGO-induced apoptosis and mechanisms are unclear. Our study used western blotting and ELISA to evaluate protein levels and enzyme activities. Cell viability and apoptosis were evaluated using CCK8 assay and PE Annexin V/7-AAD double staining. Reactive oxygen species (ROS) generation and mitochondrial membrane potential (MMP) were measured using fluorescence probes. Vascular pathological changes and apoptosis were analyzed through H&E and TUNEL staining. In vitro, MGO-stimulated human umbilical vein endothelial cells (HUVECs) were treated with varying TFEL concentrations. Our results demonstrated that TFEL significantly enhanced cell viability, reduced apoptosis, downregulated caspase-3 activity, and Bax/Bcl-2 ratio. Moreover, TFEL markedly suppressed MGO-induced ROS and malondialdehyde (MDA) production while restoring antioxidant enzyme activity and MMP. TFEL pretreatment promoted the expression of p-Akt, Nrf2, and HO-1 proteins. Pharmacological inhibition of p-Akt significantly suppressed the upregulation of Nrf2 and HO-1 protein levels mediated by TFEL. Consistently, pharmacological inhibition of Nrf2 or p-Akt partially abrogated the protective effects of TFEL against MGO-induced damage in HUVECs. In vivo studies revealed that TFEL (100 and 200 mg/kg) partially restored antioxidant capacity and reduced aortic thickness and apoptosis in MGO-injured mice. In conclusion, the findings indicate that TFEL mitigates MGO-induced apoptosis via activation of p-Akt/Nrf2/HO-1 and scavenging of oxidative stress, highlighting its potential in diabetic vascular complication management.

Epigallocatechin gallate (EGCG) alleviates inflammation and endothelial dysfunction and improves pregnancy outcomes in preeclampsia (PE)-like rats via eNOS/Nrf2/HO-1 pathway

BACKGROUND AND PURPOSE

Epigallocatechin gallate (EGCG), a natural antioxidant, has shown protective effect in many diseases. We explore the effect and potential regulatory mechanisms of EGCG in preeclampsia (PE)-like rats.

METHODS AND MATERIALS

PE was mimicked in pregnant rats. EGCG was orally administered at a dosage of 25(Low, L) or 50 mg/kg (High, H) from gestational day (GD) 6-17. The blood pressure signatures, heart rates were monitored. The 24-h proteinuria and serum were analyzed. On GD 18, rats were sacrificed, and pups and placentas were weighed. Kidneys and placentas were analyzed using immunohistochemistry (IHC) and hematoxylin-eosin staining (H&E). Placentas were examined using western blot for sFlt1, eNOS, Nrf2, HO-1, SLC7A11. MDA, GSH, GPx and Fe2+ were measured.

RESULTS

EGCG inhibits systolic blood pressure, BUN, CREA, ALT, AST, UA and proteinuria levels in PE-like rats. EGCG enhances the pup weight and crown-rump length and reduces the rate of fetus growth restriction in PE group. Endothelial dysfunction and infiltration of inflammatory cells were found in kidney cortex and placenta tissues in PE group and were inhibited by EGCG treatment. sFlt1 was activated in placentas in PE group and inhibited by EGCG while eNOS/Nrf2/HO-1 were inhibited in PE group and restored by EGCG. MDA and Fe concentrations were elevated in PE group and reduced by EGCG while the GSH level, SLC7A11 and the GPx activity were inhibited in PE group and restored by EGCG.

CONCLUSION

EGCG alleviates inflammation, endothelial dysfunction and placental ferroptosis, improves pregnancy outcomes in PE-like rats via eNOS/Nrf2/HO-1.

Reduced uterine perfusion pressure as a model for preeclampsia and fetal growth restriction in murine: a systematic review and meta-analysis

The reduced uterine perfusion pressure (RUPP) model is frequently used to study preeclampsia and fetal growth restriction. An improved understanding of influential factors might improve reproducibility and reduce animal use considering the variability in RUPP phenotype. We performed a systematic review and meta-analysis by searching Medline and Embase (until 28 March, 2023) for RUPP studies in murine. Primary outcomes included maternal blood pressure (BP) or proteinuria, fetal weight or crown-rump length, fetal reabsorptions, or antiangiogenic factors. We aimed to identify influential factors by meta-regression analysis. We included 155 studies. Our meta-analysis showed that the RUPP procedure results in significantly higher BP (MD = 24.1 mmHg; [22.6; 25.7]; n = 148), proteinuria (SMD = 2.3; [0.9; 3.8]; n = 28), fetal reabsorptions (MD = 50.4%; [45.5; 55.2]; n = 42), circulating soluble FMS-like tyrosine kinase-1 (sFlt-1) (SMD = 2.6; [1.7; 3.4]; n = 34), and lower fetal weight (MD = -0.4 g; [-0.47; -0.34]; n = 113. The heterogeneity (variability between studies) in primary outcomes appeared ≥90%. Our meta-regression identified influential factors in the method and time point of BP measurement, randomization in fetal weight, and type of control group in sFlt-1. The RUPP is a robust model considering the evident differences in maternal and fetal outcomes. The high heterogeneity reflects the observed variability in phenotype. Because of underreporting, we observed reporting bias and a high risk of bias. We recommend standardizing study design by optimal time point and method chosen for readout measures to limit the variability. This contributes to improved reproducibility and thereby eventually improves the translational value of the RUPP model.

Procyanidin B2 enhances anti-inflammatory responses of periodontal ligament cells by inhibiting the dominant negative pro-inflammatory isoforms of peroxisome proliferator-activated receptor γ

Background/purpose

Periodontal breakdown in periodontitis is exacerbated by pro-inflammatory responses of periodontal stromal cells such as periodontal ligament fibroblasts (PDLFs). Procyanidin B2 (PB2) is a ligand of the peroxisome proliferator-activated receptor (PPARγ). Herein, we investigated the expression of PPARγ isoforms in PDLFs and periodontal tissue, and examined the effects of PB2 on PPARγ isoform-dependent antiinflammatory responses.

Materials and methods

PPARγ isoforms were examined by PCR. PPARγ isoform-dependent inflammatory functions and anti-inflammatory effects of PB2 in PDLFs were evaluated based on IL-6 expression. Co-immunoprecipitation analysis of fixed chromatin-tethered protein (CoIPfctp) was conducted to investigate the association of each PPARγ isoform with the NF-κB-transcriptional complex. The effects of PB2 on periodontitis progression were evaluated using a ligature-induced murine periodontitis model.

Results

Three isoforms of PPARγ were expressed in PDLFs and periodontal tissues, consisting of the main full-length isoform (PPARγ) and two dominant negative isoforms that lack the ligand binding domain, namely the ubiquitously-expressed isoform (PPARγ-UBI) and unknown isoform (PPARγ-PDL). PPARγ and PPARγ-UBI were predominantly expressed. CoIP-fctp revealed that PPARγ-UBI was selectively associated with NF-κB p65, a key transcriptional factor of IL-6 expression. PB2 suppressed LPS-induced-IL-6 expression exacerbated by the over-expression of PPARγ-UBI. In the murine periodontitis model, topical application of PB2 significantly mitigated alveolar bone loss.

Conclusion

These results suggest that the anti-inflammatory effects of PB2 in periodontal tissues/cells are distinct, and these effects arise from the inhibition of PPARγ-UBI; hence, the application of PB2 and modification of the splicing event in three PPARγ isoforms have therapeutic potential for preventing periodontitis.

Procyanidin B2 alleviates oxidized low-density lipoprotein-induced cell injury, inflammation, monocyte chemotaxis, and oxidative stress by inhibiting the nuclear factor kappa-B pathway in human umbilical vein endothelial cells

BACKGROUND

Oxidized low-density lipoprotein (ox-LDL) can initiate and affect almost all atherosclerotic events including endothelial dysfunction. In this text, the role and underlying molecular basis of procyanidin B2 (PCB2) with potential anti-oxidant and anti-inflammatory activities in ox-LDL-induced HUVEC injury were examined.

METHODS

HUVECs were treated with ox-LDL in the presence or absence of PCB2. Cell viability and apoptotic rate were examined by CCK-8 assay and flow cytometry, respectively. The mRNA and protein levels of genes were tested by RT-qPCR and western blot assays, respectively. Potential downstream targets and pathways of apple procyanidin oligomers were examined by bioinformatics analysis for the GSE9647 dataset. The effect of PCB2 on THP-1 cell migration was examined by recruitment assay. The effect of PCB2 on oxidative stress was assessed by reactive oxygen species (ROS) level, malondialdehyde (MDA) content, and mitochondrial membrane potential (MMP).

RESULTS

ox-LDL reduced cell viability, induced cell apoptosis, and facilitated the expression of oxidized low-density lipoprotein receptor 1 (LOX-1), C-C motif chemokine ligand 2 (MCP-1), vascular cell adhesion protein 1 (VCAM-1) in HUVECs. PCB2 alleviated ox-LDL-induced cell injury in HUVECs. Apple procyanidin oligomers triggered the differential expression of 592 genes in HUVECs (|log2fold-change| > 0.58 and adjusted p-value < 0.05). These dysregulated genes might be implicated in apoptosis, endothelial cell proliferation, inflammation, and monocyte chemotaxis. PCB2 inhibited C-X-C motif chemokine ligand 1/8 (CXCL1/8) expression and THP-1 cell recruitment in ox-LDL-stimulated HUVECs. PCB2 inhibited ox-LDL-induced oxidative stress and nuclear factor kappa-B (NF-κB) activation in HUVECs.

CONCLUSION

PCB2 weakened ox-LDL-induced cell injury, inflammation, monocyte recruitment, and oxidative stress by inhibiting the NF-κB pathway in HUVECs.

Klotho-mediated activation of the anti-oxidant Nrf2/ARE signal pathway affects cell apoptosis, senescence and mobility in hypoxic human trophoblasts: involvement of Klotho in the pathogenesis of preeclampsia

The anti-aging gene Klotho is implicated in the pathogenesis of preeclampsia (PE), which is a pregnancy disease characterized by hypertension and proteinuria. Oxidative stress is closely associated with the worse outcomes in PE, and Klotho can eliminate Reactive Oxygen Species (ROS), but it is still unclear whether Klotho regulates PE pathogenesis through modulating oxidative damages. Here, by analyzing the clinical data, we found that Klotho was aberrantly downregulated in PE umbilical cord serum and placental tissues, compared to their normal counterparts. In in vitro experiments, the human trophoblasts were subjected to hypoxic pressure to establish the PE models, and we confirmed that hypoxia also decreased the expression levels of Klotho in those trophoblasts. In addition, through performing functional experiments, we confirmed that hypoxia promoted oxidative damages, cell apoptosis and senescence, whereas suppressed cell invasion in human trophoblasts, which were all reversed overexpressing Klotho. The following mechanical experiments verified that Klotho increased the levels of nuclear Nrf2, total Nrf2, SOD2 and NQO1 to activate the anti-oxidant Nrf2/ARE signal pathway, and silencing of Nrf2 abrogated the protective effects of Klotho overexpression on hypoxic human trophoblasts. Consistently, in in vivo experiments, Klotho overexpression restrained oxidative damages and facilitated cell mitosis in PE rats' placental tissues. In conclusion, this study validated that Klotho activated the Nrf2/ARE signal pathway to eliminate hypoxia-induced oxidative damages, cell apoptosis and senescence to recover normal cellular functions in human trophoblasts, and our data supported that Klotho could be used as novel biomarker for PE diagnosis and treatment.

HMOX1 Participates in Pre-Eclampsia by Regulating the Proliferation, Apoptosis, and Angiogenesis Modulation Potential of Mesenchymal Stem Cells via VEGF

Mesenchymal stem cells (MSCs) are involved in the pathogenesis of pre-eclampsia (PE). Heme oxygenase (HMOX) protects against placental cytotoxic injuries associated with PE. Here, we aimed to clarify the roles of HMOX1 in MSC proliferation and apoptosis, trophoblast cell migration, and regulation of angiogenesis, and assess its involvement in the pathogenesis of PE. HMOX1 and vascular endothelial growth factor (VEGF) expression levels in decidual tissues and decidua-derived MSCs (dMSCs) of healthy pregnant women and patients with PE were evaluated via quantitative reverse transcription-polymerase chain reaction and western blotting. Moreover, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, flow cytometry, and transwell assays were used to analyze the cell viability, apoptosis, and migration, respectively. The tube formation ability of human umbilical vein endothelial cells (HUVECs) was also evaluated. Compared to the healthy pregnant women, HMOX1 expression was upregulated in the decidual tissue and downregulated in the dMSCs of patients with PE. HMOX1 overexpression significantly increased dMSC proliferation, decreased cell apoptosis, and increased VEGF expression. Moreover, HMOX1-plasmid transfected dMSC culture supernatant promoted the migration of HTR-8/SVneo cells and improved angiogenesis by HUVECs. The opposite effects were observed in HMOX1-small interfering RNA-treated dMSCs cells. However, VEGF-siRNA reversed the effects of HMOX1-plasmid. HMOX1 is involved in the pathogenesis of PE by regulating the proliferation, apoptosis, and angiogenesis modulation potential of MSCs via VEGF, acting as a potential therapeutic target for PE.

Extracellular Vesicles Derived from Human Umbilical Cord MSC Improve Vascular Endothelial Function in In Vitro and In Vivo Models of Preeclampsia through Activating Arginine Metabolism

Endothelial cell damage is an important feature of preeclampsia (PE). Human umbilical mesenchymal stem-cell-derived extracellular vesicles (HUMSCs-derived EVs) have been shown to have therapeutic effects on a variety of diseases and tissue damage. However, the therapeutic effect of HUMSCs-derived EVs on endothelial injury in PE remains unclear. This study explored the possible mechanism of HUMSCs-derived EVs in the treatment of endothelial cell injury. Tumor necrosis factor α- and lipopolysaccharide-induced endothelial dysfunction models were used to evaluate the therapeutic effect of HUMSCs-derived EVs on endothelial injury. We further constructed PE mouse models to explore the function of HUMSCs-derived EVs in vivo. The changes of metabolites in endothelial cells after HUMSCs-derived EVs treatment were analyzed by metabolomics analysis and further validated by cell experiments. HUMSCs-derived EVs treatment can alleviate endothelial cell injury in PE, involving cell proliferation, migration, angiogenesis, and anti-inflammatory. Importantly, administration of HUMSCs-derived EVs improves hypertension and proteinuria in PE mice, alleviates kidney damage, and promotes vascularization in the placenta. Furthermore, metabolomics analysis found that the arginine metabolic pathway is activated after HUMSCs-derived EVs treatment. We also observed increased arginine level, nitric oxide content, and nitric oxide synthase activity, and further experiments proved that activating the arginine metabolic pathway could alleviate endothelial dysfunction. Our results reveal that HUMSCs-derived EVs could ameliorate PE endothelial dysfunction by activating the arginine metabolic pathway and may serve as a therapeutic method for treating PE.

Effects of astragaloside IV on glucocorticoid-induced avascular necrosis of the femoral head via regulating Akt-related pathways

We investigated the role of astragaloside IV (AS-IV) in preventing glucocorticoid-induced avascular necrosis of the femoral head (ANFH) and the underlying molecular mechanisms. Network pharmacology was used to predict the molecular targets of AS-IV. Molecular dynamic simulations were performed to explore the binding mechanism and interaction mode between AS-IV and Akt. Rat models of glucocorticoid-induced ANFH with AS-IV intervention were established, and osteogenesis, angiogenesis, apoptosis and oxidative stress were evaluated before and after blocking the PI3K/Akt pathway with LY294002. The effects of glucocorticoid and AS-IV on bone marrow mesenchymal stem cells and human umbilical vein endothelial cells incubated with and without LY294002 were determined. Downregulated p-Akt expression could be detected in the femoral heads of glucocorticoid-induced ANFH patients and rats. AS-IV increased trabecular bone integrity and vessel density of the femoral head in the model rats. AS-IV increased Akt phosphorylation and upregulated osteogenesis-, angiogenesis-, apoptosis- and oxidative stress-related proteins and mRNA and downregulated Bax, cleaved caspase-3 and cytochrome c levels. AS-IV promoted human umbilical vein endothelial cell migration, proliferation and tube formation ability; bone marrow mesenchymal stem cell proliferation; and osteogenic differentiation under glucocorticoid influence. AS-IV inhibited apoptosis. LY294002 inhibited these effects. AS-IV prevented glucocorticoid-induced ANFH by promoting osteogenesis and angiogenesis via the Akt/Runx2 and Akt/HIF-1α/VEGF pathways, respectively, and suppressing apoptosis and oxidative stress via the Akt/Bad/Bcl-2 and Akt/Nrf2/HO-1 pathways, respectively.

Procyanidin B2: A promising multi-functional food-derived pigment for human diseases

Natural edible pigments play a paramount part in the food industry. Procyanidin B2 (PB2), one of the most representative naturally occurring edible pigments, is usually isolated from the seeds, fruits, and leaves of lots of common plants, such as grapes, Hawthorn, black soybean, as well as blueberry, and functions as a food additive in daily life. Notably, PB2 has numerous bioactivities and possesses the potential to treat/prevent a wide range of human diseases, such as diabetes mellitus, diabetic complications, atherosclerosis, and non-alcoholic fatty liver disease, and the underlying mechanisms were partially elucidated, including mediating signaling pathways like NF-κB, MAPK, PI3K/Akt, apoptotic axis, and Nrf-2/HO-1. This paper presents a review of the natural sources, bioactivities, and the therapeutic/preventive potential of PB2 and the possible mechanisms, with the aim of promoting the development of PB2 as a functional food and providing references for its clinical application in the treatment of diseases.

Modulation of NRF2/KEAP1 Signaling in Preeclampsia

Placentation is a key and tightly regulated process that ensures the normal development of the placenta and fetal growth. Preeclampsia (PE) is a hypertensive pregnancy-related disorder involving about 5-8% of all pregnancies and clinically characterized by de novo maternal hypertension and proteinuria. In addition, PE pregnancies are also characterized by increased oxidative stress and inflammation. The NRF2/KEAP1 signaling pathway plays an important role in protecting cells against oxidative damage due to increased reactive oxygen species (ROS) levels. ROS activate NRF2, allowing its binding to the antioxidant response element (ARE) region present in the promoter of several antioxidant genes such as heme oxygenase, catalase, glutathione peroxidase and superoxide dismutase that neutralize ROS, protecting cells against oxidative stress damages. In this review, we analyze the current literature regarding the role of the NRF2/KEAP1 pathway in preeclamptic pregnancies, discussing the main cellular modulators of this pathway. Moreover, we also discuss the main natural and synthetic compounds that can regulate this pathway in in vivo and in vitro models.

Understanding PPARγ and Its Agonists on Trophoblast Differentiation and Invasion: Potential Therapeutic Targets for Gestational Diabetes Mellitus and Preeclampsia

The increasing incidence of pregnancy complications, particularly gestational diabetes mellitus (GDM) and preeclampsia (PE), is a cause for concern, as they can result in serious health consequences for both mothers and infants. The pathogenesis of these complications is still not fully understood, although it is known that the pathologic placenta plays a crucial role. Studies have shown that PPARγ, a transcription factor involved in glucose and lipid metabolism, may have a critical role in the etiology of these complications. While PPARγ agonists are FDA-approved drugs for Type 2 Diabetes Mellitus, their safety during pregnancy is not yet established. Nevertheless, there is growing evidence for the therapeutic potential of PPARγ in the treatment of PE using mouse models and in cell cultures. This review aims to summarize the current understanding of the mechanism of PPARγ in placental pathophysiology and to explore the possibility of using PPARγ ligands as a treatment option for pregnancy complications. Overall, this topic is of great significance for improving maternal and fetal health outcomes and warrants further investigation.

Mitochondrial ROS Accumulation Contributes to Maternal Hypertension and Impaired Remodeling of Spiral Artery but Not IUGR in a Rat PE Model Caused by Maternal Glucocorticoid Exposure

Increased maternal glucocorticoid levels have been implicated as a risk factor for preeclampsia (PE) development. We found that pregnant rats exposed to dexamethasone (DEX) showed hallmarks of PE features, impaired spiral artery (SA) remodeling, and elevated circulatory levels of sFlt1, sEng IL-1β, and TNFα. Abnormal mitochondrial morphology and mitochondrial dysfunction in placentas occurred in DEX rats. Omics showed that a large spectrum of placental signaling pathways, including oxidative phosphorylation (OXPHOS), energy metabolism, inflammation, and insulin-like growth factor (IGF) system were affected in DEX rats. MitoTEMPO, a mitochondria-targeted antioxidant, alleviated maternal hypertension and renal damage, and improved SA remodeling, uteroplacental blood flow, and the placental vasculature network. It reversed several pathways, including OXPHOS and glutathione pathways. Moreover, DEX-induced impaired functions of human extravillous trophoblasts were associated with excess ROS caused by mitochondrial dysfunction. However, scavenging excess ROS did not improve intrauterine growth retardation (IUGR), and elevated circulatory sFlt1, sEng, IL-1β, and TNFα levels in DEX rats. Our data indicate that excess mitochondrial ROS contributes to trophoblast dysfunction, impaired SA remodeling, reduced uteroplacental blood flow, and maternal hypertension in the DEX-induced PE model, while increased sFlt1 and sEng levels and IUGR might be associated with inflammation and an impaired energy metabolism and IGF system.

Preeclampsia is associated with reduced renin, aldosterone, and PlGF levels, and increased sFlt-1/PlGF ratio, and specific angiotensin-converting enzyme Ins-Del gene variants

We investigated the association of angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism with preeclampsia (PE) in Tunisian women. ACE I/D genotyping was done by PCR in 342 pregnant women with PE and 289 healthy pregnant women. The association between ACE I/D and PE and associated features were also evaluated. Decreased active renin concentration, plasma aldosterone concentration, and placental growth factor (PlGF) were observed in PE cases, while soluble fms-like tyrosine kinase-1 (sFlt-1)/PlGF ratio was significantly higher in the PE group. Distribution of ACE I/D alleles and genotypes were comparable between women with PE and control women. A significant difference in the frequency of the I/I genotype was seen between PE cases and control women according to the recessive model, with a trend towards association in the codominant model. Carriers of the I/I genotype had significantly higher infant birth weights compared to the I/D and the D/D genotype carriers. A dose-dependent relationship was also seen in VEGF and PlGF plasma levels and specific ACE I/D genotypes, with the lowest VEGF levels seen in the I/I genotype carriers compared to the D/D genotype carriers. Similarly, the I/I genotype carriers had the lowest PlGF levels compared to I/D and D/D genotype carriers. Furthermore, when studying the linkage between PE features, we found a positive correlation between PAC and PIGF. Our study suggests a role for ACE I/D polymorphism in the pathogenesis of PE, possibly through modulating VEGF and PlGF levels and infant birth weight, and highlights the relationship between PAC and PlGF.

The Role of Peroxisome Proliferator-Activated Receptors in Preeclampsia

Preeclampsia is a common pregnancy-related hypertensive disorder. Often presenting as preexisting or new-onset hypertension complicated by proteinuria and/or end-organ dysfunction, preeclampsia significantly correlates with maternal and perinatal morbidity and mortality. Peroxisome proliferator-activated receptors (PPARs) are nuclear receptor proteins that regulate gene expression. In order to investigate the role of PPARs in the pathophysiology of preeclampsia, we conducted a literature review using the MEDLINE and LIVIVO databases. The search terms "peroxisome proliferator-activated receptor", "PPAR", and "preeclampsia" were employed and we were able to identify 35 relevant studies published between 2002 and 2022. Different study groups reached contradictory conclusions in terms of PPAR expression in preeclamptic placentae. Interestingly, PPARγ agonists alone, or in combination with well-established pharmaceutical agents, were determined to represent novel, potent anti-preeclamptic treatment alternatives. In conclusion, PPARs seem to play a significant role in preeclampsia.

Nrf2-Mediated Dichotomy in the Vascular System: Mechanistic and Therapeutic Perspective

Nuclear factor-erythroid 2-related factor 2 (Nrf2), a transcription factor, controls the expression of more than 1000 genes that can be clustered into different categories with distinct functions ranging from redox balance and metabolism to protein quality control in the cell. The biological consequence of Nrf2 activation can be either protective or detrimental in a context-dependent manner. In the cardiovascular system, most studies have focused on the protective properties of Nrf2, mainly as a key transcription factor of antioxidant defense. However, emerging evidence revealed an unexpected role of Nrf2 in mediating cardiovascular maladaptive remodeling and dysfunction in certain disease settings. Herein we review the role of Nrf2 in cardiovascular diseases with a focus on vascular disease. We discuss the negative effect of Nrf2 on the vasculature as well as the potential underlying mechanisms. We also discuss the clinical relevance of targeting Nrf2 pathways for the treatment of cardiovascular and other diseases.

Beneficial effects of procyanidin B2 on adriamycin-induced nephrotic syndrome mice: the multi-action mechanism for ameliorating glomerular permselectivity injury

Despite considerable advances in prevention, diagnosis, and therapy, nephrotic syndrome (NS) remains a significant cause of high morbidity and mortality globally. As a result, there is an urgent need to identify novel effective preventative and therapeutic agents for NS. NS is implicated in glomerular permselectivity injury, which can be attributed to oxidative distress, inflammation, lipid nephrotoxicity, podocyte apoptosis, autophagy dysfunction, and slit diaphragm (SLD) dysfunction. In addition to its well-documented antioxidant potency, procyanidin B2 (PB2) may exhibit pleiotropic effects by targeting various canonical signaling events, such as NF-κB, PPARs, PI3K/Akt, mTOR, and the caspase family. As a result, PB2 may be a promising therapeutic target against NS. To test this hypothesis, we established an Adriamycin (ADR)-induced NS mouse model to evaluate the pleiotropic renoprotective effects of PB2 on NS. Here, we demonstrated that PB2 improves podocyte injury via inhibition of NOX4/ROS and Hsp90/NF-κB to exhibit antioxidant and anti-inflammatory potency, respectively. We also show that PB2 indirectly activates the PI3K/Akt axis by regulating SLD protein levels, resulting in normalized podocyte apoptosis and autophagy function. Further, loss of albumin (ALB) induces lipid nephrotoxicity, which we found to be alleviated by PB2 via activation of PPARα/β-mediated lipid homeostasis and the cholesterol efflux axis. Interestingly, our results also suggested that PB2 reduces electrolyte abnormalities and edema. In addition, PB2 may contribute protective effects against trace element dys-homeostasis, which, through alleviating serum ALB loss, leads to a protective effect on glomerular permselectivity injury. Taken together, our results reveal that the identified mechanisms of PB2 on NS are multifactorial and involve inhibition of oxidative distress and inflammatory responses, as well as improvements in podocyte apoptosis and autophagy dysfunction, amelioration of lipid nephrotoxicity, and modulation of electrolyte abnormalities and edema. Thus, we provide a theoretical basis for the clinical application of PB2 against NS.

Procyanidin B2 Attenuates Nicotine-Induced Hepatocyte Pyroptosis through a PPARγ-Dependent Mechanism

Procyanidin B2 (PCB2), a natural flavonoid, has been demonstrated to exert anti-oxidation and anti-inflammatory effects on hepatic diseases. Increasing evidence shows the hepatoxicity of nicotine. However, whether PCB2 protects against nicotine-induced hepatoxicity and the underlying mechanisms remains uncharacterized. Here, we reported that nicotine promoted hepatocyte pyroptosis, as evidenced by the elevation of propidium iodide (PI)-positive cells, the activation of Caspase-1 and gasdermin D (GSDMD), the enhanced expression of NOD-like receptor containing pyrin domain 3 (NLRP3) and the increased release of lactate dehydrogenase (LDH), interleukin (IL)-1β and IL-18. The silencing of GSDMD by small interfering RNA (siRNA) efficiently inhibited the release of LDH and the secretion of IL-1β and IL-18. In addition, rosiglitazone (RGZ) prevented hepatocyte pyroptosis induced by nicotine. Furthermore, we showed that PCB2 attenuated nicotine-induced pyroptosis through the activation of peroxisome proliferator-activated receptor-γ (PPARγ) in hepatocytes. Moreover, administration of PCB2 ameliorated liver injury and hepatocyte pyroptosis in nicotine-treated mice. Hence, our findings demonstrated that PCB2 attenuated pyroptosis and liver damage in a PPARγ-dependent manner. Our results suggest a new mechanism by which PCB2 exerts its liver protective effects.