Sulfasalazine augments a pro-inflammatory response in interleukin-1β-stimulated amniocytes and myocytes

Extracellular Vesicles-mediated recombinant IL-10 protects against ascending infection-associated preterm birth by reducing fetal inflammatory response

Background

Fetal inflammatory response mediated by the influx of immune cells and activation of pro-inflammatory transcription factor NF-κB in feto-maternal uterine tissues is the major determinant of infection-associated preterm birth (PTB, live births < 37 weeks of gestation).

Objective

To reduce the incidence of PTB by minimizing inflammation, extracellular vesicles (EVs) were electroporetically engineered to contain anti-inflammatory cytokine interleukin (IL)-10 (eIL-10), and their efficacy was tested in an ascending model of infection (vaginal administration of E. coli) induced PTB in mouse models.

Study design

EVs (size: 30-170 nm) derived from HEK293T cells were electroporated with recombinant IL-10 at 500 volts and 125 Ω, and 6 pulses to generate eIL-10. eIL-10 structural characters (electron microscopy, nanoparticle tracking analysis, ExoView [size and cargo content] and functional properties (co-treatment of macrophage cells with LPS and eIL-10) were assessed. To test efficacy, CD1 mice were vaginally inoculated with E. coli (1010CFU) and subsequently treated with either PBS, eIL-10 (500ng) or Gentamicin (10mg/kg) or a combination of eIL-10+gentamicin. Fetal inflammatory response in maternal and fetal tissues after the infection or treatment were conducted by suspension Cytometer Time of Flight (CyTOF) using a transgenic mouse model that express red fluorescent TdTomato (mT+) in fetal cells.

Results

Engineered EVs were structurally and functionally stable and showed reduced proinflammatory cytokine production from LPS challenged macrophage cells in vitro. Maternal administration of eIL-10 (10 µg/kg body weight) crossed feto-maternal barriers to delay E. coli-induced PTB to deliver live pups at term. Delay in PTB was associated with reduced feto-maternal uterine inflammation (immune cell infiltration and histologic chorioamnionitis, NF-κB activation, and proinflammatory cytokine production).

Conclusions

eIL-10 administration was safe, stable, specific, delayed PTB by over 72 hrs and delivered live pups. The delivery of drugs using EVs overcomes the limitations of in-utero fetal interventions. Protecting IL-10 in EVs eliminates the need for the amniotic administration of recombinant IL-10 for its efficacy.

New Ideas for the Prevention and Treatment of Preeclampsia and Their Molecular Inspirations

Preeclampsia (PE) is a pregnancy-specific disorder affecting 4-10% of all expectant women. It greatly increases the risk of maternal and foetal death. Although the main symptoms generally appear after week 20 of gestation, scientific studies indicate that the mechanism underpinning PE is initiated at the beginning of gestation. It is known that the pathomechanism of preeclampsia is strongly related to inflammation and oxidative stress, which influence placentation and provoke endothelial dysfunction in the mother. However, as of yet, no "key players" regulating all these processes have been discovered. This might be why current therapeutic strategies intended for prevention or treatment are not fully effective, and the only effective method to stop the disease is the premature induction of delivery, mostly by caesarean section. Therefore, there is a need for further research into new pharmacological strategies for the treatment and prevention of preeclampsia. This review presents new preventive methods and therapies for PE not yet recommended by obstetrical and gynaecological societies. As many of these therapies are in preclinical studies or under evaluation in clinical trials, this paper reports the molecular targets of the tested agents or methods.

Interventions for Infection and Inflammation-Induced Preterm Birth: a Preclinical Systematic Review

Spontaneous preterm births (< 37 weeks gestation) are frequently associated with infection. Current treatment options are limited but new therapeutic interventions are being developed in animal models. In this PROSPERO-registered preclinical systematic review, we aimed to summarise promising interventions for infection/inflammation-induced preterm birth. Following PRISMA guidance, we searched PubMed, EMBASE, and Web of Science using the themes: "animal models", "preterm birth", "inflammation", and "therapeutics". We included original quantitative, peer-reviewed, and controlled studies applying prenatal interventions to prevent infection/inflammation-induced preterm birth in animal models. We employed two risk of bias tools. Of 4020 identified studies, 23 studies (24 interventions) met our inclusion criteria. All studies used mouse models. Preterm birth was most commonly induced by lipopolysaccharide (18 studies) or Escherichia coli (4 studies). Models varied according to infectious agent serotype, dose, and route of delivery. Gestational length was significantly prolonged in 20/24 interventions (83%) and markers of maternal inflammation were reduced in 20/23 interventions (87%). Interventions targeting interleukin-1, interleukin-6, and toll-like receptors show particular therapeutic potential. However, due to the heterogeneity of the methodology of the included studies, meta-analysis was impossible. All studies were assigned an unclear risk of bias using the SYRCLE risk of bias tool. Interventions targeting inflammation demonstrate therapeutic potential for the prevention of preterm birth. However, better standardisation of preterm birth models, including the dose, serotype, timing of administration and pathogenicity of infectious agent, and outcome reporting is urgently required to improve the reproducibility of preclinical studies, allow meaningful comparison of intervention efficacy, and aid clinical translation.

Ophiopogonin D Inhibiting Epithelial NF-κB Signaling Pathway Protects Against Experimental Colitis in Mice

The sustained activation of the nuclear factor κB (NF-κB) signaling pathway has been observed in human inflammatory bowel disease (IBD). Ophiopogonin D (OP-D) is a small molecular compound isolated from Ophiopogon japonicus, a widely used herbal remedy. In this study, dextran sodium sulfate was used to make a mouse model of experimental colitis and verify the effect of OP-D on the mouse model of experimental colitis. Small molecule-protein molecular docking approaches were also used to discover the mechanisms underlying the OP-D-induced regulation of colitis. In colitis, the OP-D can inhibit the apoptosis of intestinal mucosa cells, restore the intestinal barrier, and alleviate inflammation. The molecular docking simulations showed that OP-D had a high affinity with the REL-homology domain of NF-κB-p65 that affected its translocation to the nucleus. In a cell study, the effects of OP-D on inflammation and barrier dysfunction were significantly decreased by a small interfering RNA targeting NF-κB-p65. Further, the LPS-induced increase in NF-κB-p65 in the nucleus was also significantly inhibited by OP-D. OP-D alleviated experimental colitis by inhibiting NF-κB. New insights into the pathogenesis and treatment options of colitis are provided through this study.

15-Deoxy-Delta-12,14-prostaglandin J2 modulates pro-labour and pro-inflammatory responses in human myocytes, vaginal and amnion epithelial cells

BACKGROUND

Prematurity is the leading cause of childhood death under the age of five. The aetiology of preterm birth is multifactorial; however, inflammation and infection are the most common causal factors, supporting a potential role for immunomodulation as a therapeutic strategy. 15-Deoxy-Delta-12,14-prostaglandin J2 (15dPGJ2) is an anti-inflammatory prostaglandin and has been shown to delay lipopolysaccharide (LPS) induced preterm labour in mice and improve pup survival. This study explores the immunomodulatory effect of 15dPGJ2 on the transcription factors NF-κB and AP-1, pro-inflammatory cytokines, and contraction associated proteins in human cultured myocytes, vaginal epithelial cell line (VECs) and primary amnion epithelial cells (AECs).

METHODS

Cells were pre-incubated with 32µM of 15dPGJ2 and stimulated with 1ng/mL of IL-1β as an in vitro model of inflammation. Western immunoblotting was used to detect phosphorylated p-65 and phosphorylated c-Jun as markers of NF-κB and AP-1 activation, respectively. mRNA expression of the pro-inflammatory cytokines IL-6, IL-8, and TNF-α was examined, and protein expression of COX-2 and PGE2 were detected by western immunoblotting and ELISA respectively. Myometrial contractility was examined ex-vivo using a myograph.

RESULTS

15dPGJ2 inhibited IL-1β-induced activation of NF-κB and AP-1, and expression of IL-6, IL-8, TNF-α, COX-2 and PGE2 in myocytes, with no effect on myometrial contractility or cell viability. Despite inhibiting IL-1β-induced activation of NF-κB, expression of IL-6, TNF-α, and COX-2, 15dPGJ2 led to activation of AP-1, increased production of PGE2 and increased cell death in VECs and AECs.

CONCLUSION

We conclude that 15dPGJ2 has differential effects on inflammatory modulation depending on cell type and is therefore unlikely to be a useful therapeutic agent for the prevention of preterm birth.

Pregnancy outcomes in patients with rheumatoid arthritis who discontinue methotrexate treatment to conceive

INTRODUCTION/OBJECTIVES

Rheumatoid arthritis (RA) develops at reproductive age. Methotrexate (MTX), the anchor drug for RA treatment, is contraindicated during pregnancy. We investigated pregnancy outcomes in RA patients in whom MTX was withdrawn.

METHOD

Pregnancy outcomes, RA treatment, and infertility factors were examined in patients with RA who discontinued MTX prior to attempting conception. The Mann-Whitney U test and Fisher's exact test were used to evaluate differences between the groups.

RESULTS

Of the 52 patients enrolled in this study, 33 gave birth after discontinuing MTX and 19 did not. The age at MTX discontinuation was significantly different between the childbirth and non-childbirth groups (p = 0.0258). The use of non-steroidal anti-inflammatory drugs (NSAIDs) and salazosulfapyridine was significantly different between the groups (p = 0.0079 and p = 0.0438, respectively). Patients whose time from MTX discontinuation to pregnancy was longer than 12 months had a longer previous MTX administration period (p = 0.0182) and were older at the time of pregnancy (p = 0.0128) than those whose was shorter.

CONCLUSIONS

The results suggest that to ensure successful childbirth in women with RA, the decision to conceive should be made at the youngest possible age, NSAIDs should not be used, and a shorter duration of MTX treatment should be considered before pregnancy. Nevertheless, additional studies with larger sample sizes are warranted to analyse the effects of other factors on pregnancies in patients with RA.

KEY POINTS

• Patients with RA who plan to conceive must discontinue MTX therapy. • To achieve successful pregnancy outcomes, female patients with RA should become pregnant when they are young, discontinue NSAIDs prior to conception, and shorten their durations of MTX therapy before attempting pregnancy.

Sulfasalazine maintains blood-brain barrier integrity and relieves lipopolysaccharide-induced inflammation in hCMEC/D3 cells

Sulfasalazine is a recognized therapy for inflammatory bowel disease and is of paramount importance for maintaining intestinal barrier homeostasis. However, its effects on blood-brain barrier (BBB) function and inflammation have not yet been explored. We sought to examine whether sulfasalazine has anti-inflammatory and antiapoptotic effects on the BBB. hCMEC/D3 cells are a well-established BBB in vitro model, were treated with 1 μg/mL Escherichia coli O111:B4 lipopolysaccharide for 12 h. The cell counting kit-8 assay was used to assess cell viability. The cells were also treated with gradient concentrations of sulfasalazine for 12 h. The levels of apoptosis-related proteins and inflammatory factors (IL-1χ and TNF-α IL-6) were measured by western blotting. ZO-1 and F-actin expression was measured by immunofluorescence staining. This study confirmed that 5 mM sulfasalazine improved the maintenance of BBB integrity and relieved lipopolysaccharide-induced inflammatory apoptosis and showed that sulfasalazine might be an effective treatment for BBB disruption.

Salvianolic acid B decreases interleukin-1β-induced colitis recurrence in mice

BACKGROUND

Degree of mucosal recovery is an important indicator for evaluating the therapeutic effects of drugs in treatment of inflammatory bowel disease (IBD). Increasing evidences has proved that tight junction (TJ) barrier dysfunction is one of the pathological mechanisms of IBD. The aim of this study was to observe whether enhancement of TJ can decrease colitis recurrence.

METHODS

Eighty C57BL/6 mice were randomly divided into four groups including normal group, colitis group, sulfasalazine (SASP) treated group, and traditional Chinese drug salvianolic acid B (Sal B) treated group. Colitis was established in mice by free drinking water containing dextran sulfate sodium, after treatments by SASP and Sal B, recombinant human interleukin-1β (IL-1β) was injected intraperitoneally to induce colitis recurrence.

RESULTS

Compared with sham control, cell apoptosis in colitis group was increased from 100.85 ± 3.46% to 162.89 ± 11.45% (P = 0.0038), and TJ dysfunction marker myosin light chain kinase (MLCK) was also significantly increased from 99.70 ± 9.29% to 296.23 ± 30.78% (P = 0.0025). The increased cell apoptosis was reversed by both SASP (125.99 ± 8.45% vs. 162.89 ± 11.45%, P = 0.0059) and Sal B (104.27 ± 6.09% vs. 162.89 ± 11.45%, P = 0.0044). High MLCK expression in colitis group was reversed by Sal B (182.44 ± 89.42% vs. 296.23 ± 30.78%, P = 0.0028) but not influenced by SASP (285.23 ± 41.04% vs. 296.23 ± 30.78%, P > 0.05). The recurrence rate induced by recombinant human IL-1β in Sal B-treated group was significantly lower than that in SASP-treated group.

CONCLUSIONS

These results suggested a link between intestinal mucosal barrier dysfunction, especially TJ barrier dysfunction, and colitis recurrence. The TJ barrier dysfunction in remission stage of colitis increased the colitis recurrence. This study might provide potential treatment strategies for IBD recurrence.

Novel Insights into the Regulatory Role of Nuclear Factor (Erythroid-Derived 2)-Like 2 in Oxidative Stress and Inflammation of Human Fetal Membranes

Fetal membrane dysfunction in response to oxidative stress (OS) is associated with adverse pregnancy outcomes. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is one of the regulators of innate OS response. This study evaluated changes in Nrf2 expression and its downstream targets heme oxygenase (HO-1) and peroxisome proliferator-activated receptor gamma (PPARγ) in fetal membranes during OS and infection in vitro. Furthermore, we tested the roles of sulforaphane (SFN; an extract from cruciferous vegetables) and trigonelline (TRN; an aromatic compound in coffee) in regulating Nrf2 and its targets. Fetal membranes (n = 6) collected at term were placed in an organ explant system were treated with water-soluble cigarette smoke extract (CSE), an OS inducer (1:10), and lipopolysaccharide (LPS; 100 ng/mL). Nrf2 expression, expression, its enhancement by sulforaphane (SFN, 10 µM/mL) and down regulation by TRN (10uM/mL) was determined by western blots. Expression of Nrf2 response elements PPARγ (western) heme oxygenase (HO-1), and IL-6 were quantified by ELISA. CSE and LPS treatment of fetal membranes increased nrf2, but reduced HO-1 and PPARγ and increased IL-6. Co-treatment of SFN, but not with TRN, with CSE and LPS increased Nrf2 substantially, as well as increased HO-1 and PPARγ and reduced IL-6 expression. Risk factor-induced Nrf2 increase is insufficient to generate an antioxidant response in fetal membranes. Sulforaphane may enhance innate antioxidant and anti-inflammatory capacity by increasing NRF-2 expression.

Differential Response of Gestational Tissues to TLR3 Viral Priming Prior to Exposure to Bacterial TLR2 and TLR2/6 Agonists

Background: Infection/inflammation is an important causal factor in spontaneous preterm birth (sPTB). Most mechanistic studies have concentrated on the role of bacteria, with limited focus on the role of viruses in sPTB. Murine studies support a potential multi-pathogen aetiology in which a double or sequential hit of both viral and bacterial pathogens leads to a higher risk preterm labour. This study aimed to determine the effect of viral priming on bacterial induced inflammation in human in vitro models of ascending and haematogenous infection.

Methods: Vaginal epithelial cells, and primary amnion epithelial cells and myocytes were used to represent cell targets of ascending infection while interactions between peripheral blood mononuclear cells (PBMCs) and placental explants were used to model systemic infection. To model the effect of viral priming upon the subsequent response to bacterial stimuli, each cell type was stimulated first with a TLR3 viral agonist, and then with either a TLR2 or TLR2/6 agonist, and responses compared to those of each agonist alone. Immunoblotting was used to detect cellular NF-κB, AP-1, and IRF-3 activation. Cellular TLR3, TLR2, and TLR6 mRNA was quantified by RT-qPCR. Immunoassays were used to measure supernatant cytokine, chemokine and PGE2 concentrations.

Results: TLR3 (“viral”) priming prior to TLR2/6 agonist (“bacterial”) exposure augmented the pro-inflammatory, pro-labour response in VECs, AECs, myocytes and PBMCs when compared to the effects of agonists alone. In contrast, enhanced anti-inflammatory cytokine production (IL-10) was observed in placental explants. Culturing placental explants in conditioned media derived from PBMCs primed with a TLR3 agonist enhanced TLR2/6 agonist stimulated production of IL-6 and IL-8, suggesting a differential response by the placenta to systemic inflammation compared to direct infection as a result of haematogenous spread. TLR3 agonism generally caused increased mRNA expression of TLR3 and TLR2 but not TLR6.

Conclusion: This study provides human in vitro evidence that viral infection may increase the susceptibility of women to bacterial-induced sPTB. Improved understanding of interactions between viral and bacterial components of the maternal microbiome and host immune response may offer new therapeutic options, such as antivirals for the prevention of PTB.

Fortunellin-Induced Modulation of Phosphatase and Tensin Homolog by MicroRNA-374a Decreases Inflammation and Maintains Intestinal Barrier Function in Colitis

Activation of phosphatase and tensin homolog (PTEN) is known to induce cell apoptosis. MicroRNA-374a (miR-374a), which can suppress PTEN expression, has been found abnormally expressed in inflammatory bowel disease (IBD). Fortunellin is a citrus flavonoid that is a potential anti-inflammation agent in inflammatory diseases. The present study investigated the effects and mechanisms underlying fortunellin-induced inhibition of PTEN in IBD. Colitis was established in rats by the intracolonic administration of 2,4,6-trinitrobenzene sulfonic acid to mimic human ulcerative colitis, which is the main type of IBD. miR-374a expression was measured by quantitative real-time polymerase chain reaction, and the regulation of PTEN by miR-374a was evaluated by dual luciferase reporter assay. Western blotting was used to measure the corresponding protein expression. Fortunellin ameliorated colitis symptoms, including excessive inflammation and oxidative stress. Fortunellin decreased epithelial cell apoptosis through inhibiting PTEN expression in colitis. Fortunellin-induced downregulation of PTEN could be counteracted by miR-374a depletion. Moreover, knockdown of miR-374a in vivo partly inhibited the effects of fortunellin on rat colitis. In conclusion, PTEN inhibition contributes to the amelioration effects of fortunellin on colitis. It was confirmed that fortunellin targets miR-374a, which is a negative regulator of PTEN. This study provides novel insights into the pathological mechanisms and treatment alternatives of colitis.

Inhibition of SLC7A11 by Sulfasalazine Enhances Osteogenic Differentiation of Mesenchymal Stem Cells by Modulating BMP2/4 Expression and Suppresses Bone Loss in Ovariectomized Mice

An imbalance in osteogenesis and adipogenesis is a crucial pathological factor in the development of osteoporosis. Many attempts have been made to develop drugs to prevent and treat this disease. In the present study, we investigated the phenomenon whereby downregulation of SLC7A11 significantly enhanced the osteogenic differentiation of mesenchymal stem cells (MSCs) in vitro, and promoted the bone formation in vivo. Sulfasalazine (SAS), an inhibitor of SLC7A11, increased the osteogenic potential effectively. Mechanistically, inhibition of SLC7A11 by SAS treatment or knockdown of SLC7A11 increased BMP2/4 expression dramatically. In addition, we detected increased Slc7a11 expression in bone marrow MSCs of ovariectomized (OVX) mice. Remarkably, SAS treatment attenuated bone loss in ovariectomized mice. Together, our data suggested that SAS could be used to treat osteoporosis by enhancing osteogenic differentiation of MSCs. © 2016 American Society for Bone and Mineral Research.