G protein coupled receptors signaling pathways implicate in inflammatory and immune response of rheumatoid arthritis

PGE2 Potentiates Orai1-Mediated Calcium Entry Contributing to Peripheral Sensitization

Peripheral sensitization is one of the primary mechanisms underlying the pathogenesis of chronic pain. However, candidate molecules involved in peripheral sensitization remain incompletely understood. We have shown that store-operated calcium channels (SOCs) are expressed in the dorsal root ganglion (DRG) neurons. Whether SOCs contribute to peripheral sensitization associated with chronic inflammatory pain is elusive. Here we report that global or conditional deletion of Orai1 attenuates Complete Freund's adjuvant (CFA)-induced pain hypersensitivity in both male and female mice. To further establish the role of Orai1 in inflammatory pain, we performed calcium imaging and patch-clamp recordings in wild-type (WT) and Orai1 knockout (KO) DRG neurons. We found that SOC function was significantly enhanced in WT but not in Orai1 KO DRG neurons from CFA- and carrageenan-injected mice. Interestingly, the Orai1 protein level in L3/4 DRGs was not altered under inflammatory conditions. To understand how Orai1 is modulated under inflammatory pain conditions, prostaglandin E2 (PGE2) was used to sensitize DRG neurons. PGE2-induced increase in neuronal excitability and pain hypersensitivity was significantly reduced in Orai1 KO mice. PGE2-induced potentiation of SOC entry (SOCE) was observed in WT, but not in Orai1 KO DRG neurons. This effect was attenuated by a PGE2 receptor 1 (EP1) antagonist and mimicked by an EP1 agonist. Inhibition of Gq/11, PKC, or ERK abolished PGE2-induced SOCE increase, indicating PGE2-induced SOCE enhancement is mediated by EP1-mediated downstream cascade. These findings demonstrate that Orai1 plays an important role in peripheral sensitization. Our study also provides new insight into molecular mechanisms underlying PGE2-induced modulation of inflammatory pain.Significance Statement Store-operated calcium channel (SOC) Orai1 is expressed and functional in dorsal root ganglion (DRG) neurons. Whether Orai1 contributes to peripheral sensitization is unclear. The present study demonstrates that Orai1-mediated SOC function is enhanced in DRG neurons under inflammatory conditions. Global and conditional deletion of Orai1 attenuates complete Freund's adjuvant (CFA)-induced pain hypersensitivity. We also demonstrate that prostaglandin E2 (PGE2) potentiates SOC function in DRG neurons through EP1-mediated signaling pathway. Importantly, we have found that Orai1 deficiency diminishes PGE2-induced SOC function increase and reduces PGE2-induced increase in neuronal excitability and pain hypersensitivity. These findings suggest that Orai1 plays an important role in peripheral sensitization associated with inflammatory pain. Our study reveals a novel mechanism underlying PGE2/EP1-induced peripheral sensitization. Orai1 may serve as a potential target for pathological pain.

β-Arrestin 2 acts an adaptor protein that facilitates viral replication in silkworm

β-Arrestin 2 is known to be a widely distributed adaptor protein in mammals but its function has never been reported in Lepidoptera insects. Herein, the β-Arrestin 2 (BmArrestin 2) gene from silkworm was cloned and characterized. The spatiotemporal expression level of BmArrestin 2 was highest in the gonads at the 3rd day of 5th instar, whereas the highest and lowest abundance of BmArrestin 2 were identified in the tracheal and testis, respectively. BmArrestin 2 is mainly distributed in the cytoplasm. Furthermore, in BmN cells，overexpression of BmArrestin 2 promoted Bombyx mori nucleopolyhedrovirus (BmNPV) and B. mori cytoplasmic polyhedrosis virus (BmCPV) replication as the increment of the concentration of plasmid transfection, whereas silencing the gene with specific siRNA inhibited viral replication. Replication of BmNPV and BmCPV also was weakened using BmArrestin 2 antiserum as the increment of the concentration. Immunofluorescent staining revealed the invasion of recombinant BmNPV or BmCPV was decreased after blocking endogenous BmArrestin 2. On the other hand, BmArrestin 2 co-localizes with recombinant BmNPV and BmCPV virions in BmN cells. These results suggest that BmArrestin 2 may represent a novel target for antiviral strategies, as it is an adaptor protein that plays a key role in virus replication.

TNF-alpha, IL-6, IL-10 and fatty acids in rheumatoid arthritis patients receiving cDMARD and bDMARD therapy

OBJECTIVE

The present study aimed to examine the effects of cDMARD and bDMARD therapy on both gene expressions and protein levels of TNF-α, IL-6, IL-10 and fatty acid levels in patients with RA.

METHOD

Plasma TNF-α, IL-6, and IL-10 levels were examined by the ELISA method, while TNF-α, IL-6, and IL-10 gene expression levels were examined by RT-qPCR, and fatty acid levels were examined by GC/MS.

RESULTS

IL-10 gene expression levels significantly increased in RA patients receiving cDMARD treatment compared to those of the control group. Also, eicosadienoic acid, myristoleic acid and capric acid levels were significantly lower in the patient groups compared to those in the control group.

CONCLUSION

The drugs used in the treatment of RA had no effect on the fatty acid levels whereas had effects on the mRNA and protein levels of the target cytokines.

Gs signaling pathway distinguishes hallucinogenic and nonhallucinogenic 5-HT2AR agonists induced head twitch response in mice

5- HT2A receptor is a member of the family A G-protein-coupled receptor. It is involved in many psychiatric disorders, such as depression, addiction and Parkinson's disease. 5-HT2AR targeted drugs play an important role in regulating cognition, memory, emotion and other physiological function by coupling G proteins, and their most notable function is stimulating the serotonergic hallucination. However, not all 5-HT2AR agonists exhibit hallucinogenic activity, such as lisuride. Molecular mechanisms of these different effects are not well illustrated. This study suggested that 5-HT2AR coupled both Gs and Gq protein under hallucinogenic agonists DOM and 25CN-NBOH stimulation, but nonhallucinogenic agonist lisuride and TBG only activates Gq signaling. Moreover, in head twitch response (HTR) model, we found that cAMP analogs 8-Bromo-cAMP and PDE4 inhibitor Rolipram could increase HTR, while Gs protein inhibitor Melittin could reduce HTR. Collectively, these results revealed that Gs signaling is a key signaling pathway that may distinguish hallucinogenic agonists and nonhallucinogenic agonists.

Immunomodulatory role of short neuropeptide F in the mud crab Scylla paramamosain

Short neuropeptide F (sNPF) is bioactive peptide secreted by neurons of invertebrates. It is one of the important pleiotropic neural molecules that is associated with a variety of physiological processes in invertebrates. However, little is known about the role of sNPF in the immune response. This study aimed to determine the distribution, localization, functional characteristics and signaling mechanisms of the sNPF gene and sNPF receptor (sNPF-R) gene in the mud crab Scylla paramamosain. Results of this study showed that Sp-sNPF and Sp-sNPF-R were widely expressed in neural tissue and other tissues including hemocytes. Further, in situ hybridization analysis revealed that Sp-sNPF and Sp-sNPF-R have specific localization in cerebral ganglion and hemocytes. It was also found that immune stimuli significantly induced Sp-sNPF expression in cerebral ganglion. The hemocyte-derived Sp-sNPF and Sp-sNPF-R were also efficiently activated upon immune stimulation. In vitro sNPF peptide administration enhanced phagocytic ability of hemocytes. However, this activity could be blocked through knockdown of sNPF-R-dsRNA or using adenylate cyclase inhibitors SQ 22536. The results of this study also demonstrated that the contents of signaling molecule adenylyl cyclase (AC), cyclic adenosine monophosphate (cAMP) and protein kinase A (PKA) in hemocytes can be up-regulated after incubation with sNPF peptide. In addition, the results of in vivo experiments showed that sNPF increased concentration of nitric oxide (NO) and enhanced phagocytic potential in S. paramamosain. The sNPF also significantly induced the expression of immune-related molecules at the gene level in S. paramamosain. In conclusion, the findings of this study indicate that sNPF mediates hemocyte phagocytosis via sNPF-R receptor-coupled AC-cAMP-PKA pathway and influences the innate immune processes in S. paramamosain.

B-type allatostatin regulates immune response of hemocytes in mud crab Scylla paramamosain

B-type allatostatins (AST-B) are neuropeptides that have important physiological roles in arthropods, they have also been identified in a number of crustacean species. Recent research on neuroendocrine-immune (NEI) regulatory system in invertebrates has exploded, it reveals that the NEI network plays an indispensable role in optimizing the immune response and maintaining homeostasis. Herein, mud crab Scylla paramamosain provides a primitive and ancient model to study crosstalk between the neuroendocrine and immune systems. In this study, qRT-PCR analysis showed that the nervous system was the main production site for Sp-AST-B mRNA in S. paramamosain, while its receptor gene (Sp-AST-BR) mRNA could be detected in all the analyzed tissues including hemocytes. This reveals that AST-B might act as a pleiotropic neuropeptide. In situ hybridization further confirmed that granular cells of hemocyte subpopulations express Sp-AST-BR. Time-course analysis revealed that bacteria-analog LPS or virus-analog Poly (I:C) challenge significantly induced Sp-AST-B expression in the thoracic ganglion, and the expression of Sp-AST-BR in hemocytes were also positively changed. Furthermore, mud crabs treated with a synthetic AST-B peptide significantly increased the mRNA levels of AST-BR, nuclear factor-κB (NF-κB) transcription factor (Dorsal and Relish), pro-inflammatory cytokine (IL-16) and immune-effector molecules, and also dramatically enhanced the nitric oxide (NO) production and phagocytic activity in hemocytes. Meanwhile dsRNA-mediated knockdown of Sp-AST-B remarkably suppressed the NO concentrations, phagocytic activity and the expression of immune related genes, resulting in markedly impaired ability of crabs to inhibit bacterial proliferation in vivo. Combined, these data demonstrate that AST-B induced innate immune in the mud crab.

Prioritizing Pain-Associated Targets with Machine Learning

While hundreds of genes have been associated with pain, much of the molecular mechanisms of pain remain unknown. As a result, current analgesics are limited to few clinically validated targets. Here, we trained a machine learning (ML) ensemble model to predict new targets for 17 categories of pain. The model utilizes features from transcriptomics, proteomics, and gene ontology to prioritize targets for modulating pain. We focused on identifying novel G-protein-coupled receptors (GPCRs), ion channels, and protein kinases because these proteins represent the most successful drug target families. The performance of the model to predict novel pain targets is 0.839 on average based on AUROC, while the predictions for arthritis had the highest accuracy (AUROC = 0.929). The model predicts hundreds of novel targets for pain; for example, GPR132 and GPR109B are highly ranked GPCRs for rheumatoid arthritis. Overall, gene-pain association predictions cluster into three groups that are enriched for cytokine, calcium, and GABA-related cell signaling pathways. These predictions can serve as a foundation for future experimental exploration to advance the development of safer and more effective analgesics.

IgD-Fc-Ig fusion protein, a new biological agent, inhibits T cell function in CIA rats by inhibiting IgD-IgDR-Lck-NF-κB signaling pathways

IgD-Fc-Ig fusion protein, a new biological agent, is constructed by linking a segment of human IgD-Fc with a segment of human IgG1-Fc, which specifically blocks the IgD-IgDR pathway and selectively inhibits the abnormal proliferation, activation, and differentiation of T cells. In this study we investigated whether IgD-Fc-Ig exerted therapeutic effects in collagen-induced arthritis (CIA) rats. CIA rats were treated with IgD-Fc-Ig (1, 3, and 9 mg/kg) or injected with biological agents etanercept (3 mg/kg) once every 3 days for 40 days. In the PBMCs and spleen lymphocytes of CIA rats, both T and B cells exhibited abnormal proliferation; the percentages of CD3⁺ total T cells, CD3⁺CD4⁺ Th cells, CD3⁺CD4⁺CD25⁺-activated Th cells, Th1(CD4⁺IFN-γ⁺), and Th17(CD4⁺IL-17⁺) were significantly increased, whereas the Treg (CD4⁺CD25⁺Foxp3⁺) cell percentage was decreased. IgD-Fc-Ig administration dose-dependently decreased the indicators of arthritis; alleviated the histopathology of spleen and joint; reduced serum inflammatory cytokines levels; decreased the percentages of CD3⁺ total T cells, CD3⁺CD4⁺ Th cells, CD3⁺CD4⁺CD25⁺-activated Th cells, Th1 (CD4⁺IFN-γ⁺), and Th17(CD4⁺IL-17⁺); increased Treg (CD4⁺CD25⁺Foxp3⁺) cell percentage; and down-regulated the expression of key molecules in IgD-IgDR-Lck-NF-κB signaling (p-Lck, p-ZAP70, p-P38, p-NF-κB65). Treatment of normal T cells with IgD (9 μg/mL) in vitro promoted their proliferation. Co-treatment with IgD-Fc-Ig (0.1–10 μg/mL) dose-dependently decreased IgD-stimulated T cell subsets percentages and down-regulated the IgD-IgDR-Lck-NF-κB signaling. In summary, this study demonstrates that IgD-Fc-Ig alleviates CIA and regulates the functions of T cells through inhibiting IgD-IgDR-Lck-NF-κB signaling.

An Agonist Dependent Allosteric Antagonist of Prostaglandin EP2 Receptors

All reported prostaglandin EP2 receptor antagonists have a purely orthosteric, competitive mode of action. Herein, we report the characterization of compound 1 (pubchem CID 664888) as the first EP2 antagonist that features a reversible, agonist dependent allosteric mode of action. Compound 1 displayed an unsurmountable inhibition of cAMP accumulation stimulated by different EP2 agonists in C6 glioma cells overexpressing human EP2 (C6G-hEP2). The degree of reduction of agonist potency and efficacy depended on the agonist employed. Negative allosteric modulation was not observed in C6G cells overexpressing human EP4, IP, or DP1 receptors. Moreover, in the murine microglial cell line that stably expresses human EP2 receptors (BV2-hEP2), compound 1 reduced the EP2 agonist-induced elevation of interleukin 6 (IL-6), IL-1β, and hEP2 mRNA levels and increased that of tumor necrosis factor (TNF)-α. Compound 1 was docked into a homology model of hEP2. The predicted binding site on the cytoplasmic receptor surface was similar to that of allosteric inhibitors of the β2-adrenergic, CC chemokine receptor 9 (CCR9), and CC chemokine receptor 2 (CCR2) receptors, which supports the notion of a conserved G-protein-coupled receptor (GPCR) binding pocket for allosteric inhibitors. As the first agonist dependent negative allosteric modulator of EP2 receptor, the structure of this compound may provide a basis for developing improved allosteric modulators of EP2 receptors.

Discovery of potential asthma targets based on the clinical efficacy of Traditional Chinese Medicine formulas

ETHNOPHARMACOLOGICAL RELEVANCE

Standard therapy for asthma, a highly heterogeneous disease, is primarily based on bronchodilators and immunosuppressive drugs, which confer short-term symptomatic relief but not a cure. It is difficult to discover novel bronchodilators, although potential new targets are emerging. Traditional Chinese Medicine (TCM) formulas have been used to treat asthma for more than 2000 years, forming the basis for representative asthma treatments.

AIM OF THE STUDY

Based on the efficacy of TCM formulas, anti-asthmatic herbal compounds bind proteins are potential targets for asthma therapy. This analysis will provide new drug targets and discovery strategies for asthma therapy.

MATERIALS AND METHODS

A list of candidate herbs for asthma was selected from the classical formulas (CFs) of TCM for the treatment of wheezing or dyspnea recorded in Treatise on Cold Damage and Miscellaneous Diseases (TCDMD) and from modern herbal formulas identified in the SAPHRON TCM Database using the keywords "wheezing" or "dyspnea". Compounds in the selected herbs and compounds that directly bind target proteins were acquired by searching the Herbal Ingredients' Targets Database (HITD), TCM Data Bank (TCMDB) and TCM Integrated Database (TCMID). Therapeutic targets of conventional medicine (CM) for asthma were collected by searching Therapeutic Target Database (TTD), DrugBank and PubMed as supplements. Finally, the enriched gene ontology (GO) terms of the targets were obtained using the Database for Annotation Visualization and Integrated Discovery (DAVID) and protein-protein interactions (PPI) networks were constructed using Search Tool for the Retrieval of Interacting Genes/Proteins (STRING). The effects of two selected TCM compounds, kaempferol and ginkgolide A, on cellular resistance in human airway smooth muscle cells (ASMCs) and pulmonary resistance in a mouse model were investigated.

RESULTS

The list of 32 candidate herbs for asthma was selected from 10 CFs for the treatment of wheezing or dyspnea recorded in TCDMD and 1037 modern herbal formulas obtained from the SAPHRON TCM Database. A total of 130 compounds from the 32 selected herbs and 68 herbal compounds directly bind target proteins were acquired from HITD and TCMDB. Eighty-eight therapeutic targets of CM for asthma were collected by searching TTD and PubMed as supplements. DAVID and STRING analyses showed targets of TCM formulas are primarily related to cytochrome P450 (CYP) family, transient receptor potential (TRP) channels, matrix metalloproteinases (MMPs) and ribosomal protein. Both TCM formulas and CM act on the same types of targets or signaling pathways, such as G protein-coupled receptors (GPCRs), steroid hormone receptors (SHRs), and JAK-STAT signaling pathway. The proteins directly targeted by herbal compounds, TRPM8, TRPA1, TRPV3, CYP1B1, CYP2B6, CYP1A2, CYP3A4, CYP1A1, PPARA, PPARD, NR1I2, MMP1, MMP2, ESR1, ESR2, RPLP0, RPLP1 and RPLP2, are potential targets for asthma therapy. In vitro results showed kaempferol (1 × 10^-2 mM) and ginkgolide A (1 × 10^-5 mM) significantly increased the cell index (P < 0.05 vs. histamine, n = 3) and therefore relaxed human ASMCs. In vivo results showed kaempferol (145 μg/kg) and ginkgolide A (205 μg/kg) significantly reduced pulmonary resistance (P < 0.05 vs. methacholine, n = 6).

CONCLUSION

Potential target discovery for asthma treatment based on the clinical effectiveness of TCM is a feasible strategy.

Kunxian Capsule for Rheumatoid Arthritis: Inhibition of Inflammatory Network and Reducing Adverse Reactions Through Drug Matching

Tripterygium wilfordii Hook.f and Tripterygium hypoglaucum (H.Lév.) Hutch is effective herbs to prevent aggravation of Rheumatoid arthritis (RA). However, both of them show severe side effects in the reproductive system and other systems. Kunxian Capsule (KX), a Traditional Chinese Medicine (TCM) patent prescription, comprised of 4 herbs, including H.Lév. Hutch, is reported to be an available prescription in treating RA with fewer side effects as compares to Tripterygium tablets. To reveal the pharmacological mechanism of KX in RA treatment and side effect alleviation, we collected related information of KX from open-access databases and performed various analyses. 1354 targets were identified in KX. These targets were enriched in the calcium signaling pathway, cAMP signaling pathway, cGMP-PKG signaling pathway and PI3K-AKT signaling pathway, forming biological functions, such as cofactor binding, coenzyme binding, etc. These pathways or functions mostly affect cell cycle, differentiation, and maturation of Th17 cells, macrophage, and synovial fibroblast. These targets also act on the IL-17 signaling pathway, Th17 cell differentiation signaling pathway and TNF signaling pathway, which is related to inflammation response inhibition. Next, a disease network was constructed, which indicated IMPDH2, MTHFD1 are the key genes answering for the side effects of H.Lév. Hutch. The side effect–related genes lead to the negative regulation of nucleic acid, which could be restored by the rest 3 herbs through some positive amino acid metabolism. In conclusion, KX is a relatively safe alternative approach in RA intervention.

The prostaglandin E2 increases the production of IL-17 and the expression of costimulatory molecules on γδ T cells in rheumatoid arthritis

γδ T cells play important roles in the development of rheumatoid arthritis (RA) through their antigen-presenting capacity, release of pro-inflammatory cytokines, immunomodulatory properties, interaction with CD4⁺ CD25⁺ Tregs and promotion of antibody production by helping B cells. Although prostaglandin E2 (PGE2) was proved to have the ability to enhance the antigen-presenting function of dendritic cells and IL-17 production of CD4⁺ αβ T cells in RA, the role of PGE2 in γδ T cells from RA disease has not yet been clarified. The goal of this study was to determine the role of PGE2 in γδ T cells in RA. We first demonstrated that the population of γδT17 cells increased in patients with RA compared to healthy controls. Then, IL-17A level in patients with RA was shown to increase compared to healthy controls. After adding PGE2 to γδ T cells from patients with RA, the IL-17A level increased accordingly, and the expression of the costimulatory molecules, CD80 and CD86, on these cells also increased. These results suggest that PEG2 can increase the production of IL-17A and the expression of CD80 and CD86 on γδ T cells in patients with RA. These findings will benefit to explore new therapeutic targets for RA disease.

Paeoniflorin-6'-O-benzene sulfonate alleviates collagen-induced arthritis in mice by downregulating BAFF-TRAF2-NF-κB signaling: comparison with biological agents

Paeoniflorin-6'-O-benzene sulfonate (CP-25) is a new ester derivative of paeoniflorin with improved lipid solubility and oral bioavailability, as well as better anti-inflammatory activity than its parent compound. In this study we explored whether CP-25 exerted therapeutic effects in collagen-induced arthritis (CIA) mice through regulating B-cell activating factor (BAFF)-BAFF receptors-mediated signaling pathways. CIA mice were given CP-25 or injected with biological agents rituximab or etanercept for 40 days. In CIA mice, we found that T cells and B cells exhibited abnormal proliferation; the percentages of CD19⁺ total B cells, CD19⁺CD27⁺-activated B cells, CD19⁺BAFFR⁺ and CD19⁺TACI⁺ cells were significantly increased in PBMCs and spleen lymphocytes. CP-25 suppressed the indicators of arthritis, alleviated histopathology, accompanied by reduced BAFF and BAFF receptors expressions, inhibited serum immunoglobulin levels, decreased the B-cell subsets percentages, and prevented the expressions of key molecules in NF-κB signaling. Furthermore, we showed that treatment with CP-25 reduced CD19⁺TRAF2⁺ cell expressions stimulated by BAFF and decreased TRAF2 overexpression in HEK293 cells in vitro. Thus, CP-25 restored the abnormal T cells proliferation and B-cell percentages to the normal levels, and normalized the elevated levels of IgA, IgG2a and key proteins in NF-κB signaling. In comparison, rituximab and etanercept displayed stronger anti-inflammatory activities than CP-25; they suppressed the elevated inflammatory indexes to below the normal levels in CIA mice. In summary, our results provide evidence that CP-25 alleviates CIA and regulates the functions of B cells through BAFF-TRAF2-NF-κB signaling. CP-25 would be a soft immunomodulatory drug with anti-inflammatory effect.

Pathological cardiac hypertrophy: the synergy of adenylyl cyclases inhibition in cardiac and immune cells during chronic catecholamine stress

Response to stressors in our environment and daily lives is an adaptation conserved through evolution as it is beneficial in enhancing the survival and continuity of humans. Although stressors have evolved, the drastic physiological response they elicit still remains unchanged. The chronic secretion and circulation of catecholamines to produce physical responses when they are not required may result in pathological consequences which affect cardiac function drastically. This review seeks to point out the probable implication of chronic stress in inducing an inflammation disorder in the heart. We discussed the likely synergy of a G protein-independent stimuli signaling via β₂-adrenergic receptors in both cardiomyocytes and immune cells during chronic catecholamine stress. To explain this synergy, we hypothesized the possibility of adenylyl cyclases having a regulatory effect on G protein-coupled receptor kinases. This was based on the negative correlations they exhibit during normal cardiac function and heart failures. As such, the downregulation of adenylyl cyclases in cardiomyocytes and immune cells during chronic catecholamine stress enhances the expressions of G protein-coupled receptor kinases. In addition, we explain the maladaptive roles played by G protein-coupled receptor kinase and extracellular signal-regulated kinase in the synergistic cascade that pathologically remodels the heart. Finally, we highlighted the therapeutic potentials of an adenylyl cyclases stimulator to attenuate pathological cardiac hypertrophy (PCH) and improve cardiac function in patients developing cardiac disorders due to chronic catecholamine stress.

The effects of total glucosides of paeony (TGP) and paeoniflorin (Pae) on inflammatory-immune responses in rheumatoid arthritis (RA)

Rheumatoid arthritis (RA) is a chronic inflammatory and systemic autoimmune disease with an unknown aetiology. Accumulative studies suggest that the pathogenesis of RA involves the excessive activation of synoviocytes and immune cells, increasing the secretion of inflammatory mediators and cytokines in synoviocytes, causing dysfunctional E-prostanoid (EP)-G-protein-cyclic adenosine monophosphate (cAMP) and mitogen-associated-protein kinase (MAPK) signalling in synoviocytes. Total glucosides of paeony (TGP) extracted from the roots of Paeonia lactiflora Pall, was approved by the China Food and Drug Administration as an anti-inflammatory and immuno-modulator drug in 1998. Paeoniflorin (Pae), a water-soluble monoterpene glucoside,is the main effective component of TGP. TGP and Pae produce anti-inflammatory and immuno-regulatory effects by suppressing immune cells and synoviocytes activation, decreasing inflammatory substance production and restoring abnormal signalling in synoviocytes. In this review, the regulation of the inflammatory-immune responses and the therapeutic mechanism between RA and TGP and Pae are discussed in detail. The aim of this review was to provide novel insights into the treatment of RA.

Footprints of Sepsis Framed Within Community Acquired Pneumonia in the Blood Transcriptome

We analyzed the blood transcriptome of sepsis framed within community-acquired pneumonia (CAP) and characterized its molecular and cellular heterogeneity in terms of functional modules of co-regulated genes with impact for the underlying pathophysiological mechanisms. Our results showed that CAP severity is associated with immune suppression owing to T-cell exhaustion and HLA and chemokine receptor deactivation, endotoxin tolerance, macrophage polarization, and metabolic conversion from oxidative phosphorylation to glycolysis. We also found footprints of host's response to viruses and bacteria, altered levels of mRNA from erythrocytes and platelets indicating coagulopathy that parallel severity of sepsis and survival. Finally, our data demonstrated chromatin re-modeling associated with extensive transcriptional deregulation of chromatin modifying enzymes, which suggests the extensive changes of DNA methylation with potential impact for marker selection and functional characterization. Based on the molecular footprints identified, we propose a novel stratification of CAP cases into six groups differing in the transcriptomic scores of CAP severity, interferon response, and erythrocyte mRNA expression with impact for prognosis. Our analysis increases the resolution of transcriptomic footprints of CAP and reveals opportunities for selecting sets of transcriptomic markers with impact for translation of omics research in terms of patient stratification schemes and sets of signature genes.

Prostaglandin EP2 receptor: Novel therapeutic target for human cancers (Review)

Prostaglandin E2 (PGE2) receptor 2 subtype (EP2), which is a metabolite of arachidonic acid that binds with and regulates cellular responses to PGE2, is associated with numerous physiological and pathological events in a wide range of tissues. As a stimulatory G protein‑coupled receptor, PGE2‑induced EP2 activation can activate adenylate cyclase, leading to increased cytoplasmic cAMP levels and activation of protein kinase A. The EP2 receptor can also activate the glycogen synthase kinase 3β and β‑catenin pathways. The present study aimed to review the roles of the EP2 receptor in tumor development, including immunity, chronic inflammation, angiogenesis, metastasis and multidrug resistance. Furthermore, the involvement of the EP2 receptor signaling pathway in cancer was discussed. Understanding the role and mechanisms of action of the EP2 receptor, and its importance in targeted therapy, may help identify novel methods to improve management of numerous types of cancer.

Prostaglandin E2 and IL-23 interconnects STAT3 and RoRγ pathways to initiate Th17 CD4+ T-cell development during rheumatoid arthritis

BACKGROUND

The chronic inflammation associated with rheumatoid arthritis (RA) leads to focal and systemic bone erosion of the joints resulting in a crippling disability. Recent reports indicate an increase in the incidence of RA in the coming years, placing a significant burden on healthcare resources. The incidence of RA is observed to be increasing with age and a significant proportion of those new cases will be aggressively erosive.

FINDINGS

The altered physiology, due to immune disturbances, contributes towards RA pathogenesis. The imbalance of inflammatory cytokines and non-cytokine immune modulators such as prostaglandin E2 (PGE2) and IL-23-induced pathogenic IL-17, plays a crucial role in persistent inflammation and bone degradation during RA. However, the molecular mechanism of IL-23, a key cytokine, and PGE2 in the development and perpetuation of IL-17 producing effector Th17 cells is poorly understood.

CONCLUSION

This review focuses on research findings that provide insight into the contribution of PGE2 and IL-23 during the development of pathogenic Th17 cells. We also highlight the key transcriptional factors required for Th17 development and therapeutic strategies to disrupt the interaction between IL-23 and IL-17 to prevent the end-organ damage in RA.

Effects of docosahexaenoic acid on locomotor activity in ethanol-treated HIV-1 transgenic rats

Binge drinking affects the onset and progression of human immunodeficiency virus (HIV)-associated neurological disorders. The HIV-1 transgenic (HIV-1Tg) rat was created with a gag- and pol-deleted HIV-1 viral genome to mimic HIV-infected patients receiving combination anti-retroviral therapy (cART). Docosahexaenoic acid (DHA) is a marine compound that modulates inflammatory responses. Using HIV-1Tg rats subjected to binge exposure to ethanol (EtOH), this study examined whether DHA could reduce the detrimental neurological effects of EtOH and HIV proteins. Young adult male HIV-1Tg and F344 control rats received 4 mL/kg/day saline as a control (Saline group), 20 mg/kg/day DHA (DHA group), 4.8 g/kg/day 52% w/v EtOH (EtOH group), or 4.8 g/kg/day 52% w/v EtOH and 20 mg/kg/d DHA (DHA + EtOH group) by gavage for 5 weeks (n = 6 per group). EtOH was administrated on days 5, 6, and 7 of each week. Locomotor activity (LMA) was assessed using open field tests before and 45, 90, 135, and 180 min after each treatment. Repeated binge EtOH exposure gradually decreased LMA measured before daily treatments in HIV-1Tg and F344 rats, an effect that was reversed by DHA only in the HIV-1Tg rats. Decreased LMA of rats after treatment and under the influence of EtOH was less pronounced, and the reversal effect of DHA did not reach statistical significance. The plasma endotoxin level was significantly higher in HIV-1Tg rats than in F344 rats. IL-6 and IL-18 expression in the striatum was significantly higher in the HIV-1Tg EtOH group than in the F344 EtOH group. DHA significantly decreased the high levels of IL-6, IL-18, and NF-κB expression observed in the HIV-1Tg EtOH group. DHA appears to ameliorate inflammation and consequently lessen the reductions in LMA produced by the combination of EtOH and HIV-1 viral proteins.

Role of cAMP in phenotypic changes of osteoblasts

Bone remodeling is precisely controlled by bone formation and bone resorption, and osteoblasts are responsible for both processes. Osteoblasts exhibit an osteoclastogenic phenotype in response to elevated intracellular cyclic AMP [cAMP]_i levels. However, the role of cAMP in osteoblasts acquiring an osteogenic phenotype is controversial. To elucidate the effect of cAMP on both phenotypes, an osteoblast-like cell line, TMS-12, was established in our laboratory and used in this study. Dibutyryl-cAMP (dBcAMP), a cAMP analogue, inhibited mineralization in TMS-12 cells and MC3T3E1 cells (an osteoblast-like cell line) but promoted osteoclast-supporting activity in TMS-12 cells. Moreover, mineralization was inhibited in glucagon receptor-transduced TMS-12 cells (TMS-12GCGR) after glucagon treatment to increase endogenous [cAMP]_i levels. However, the osteoclast-supporting activity of TMS-12GCGR cells was stimulated by glucagon treatment. These cAMP-induced phenotypic changes of osteoblasts were also supported by their gene expression profile. These results suggest that [cAMP]_i is an important factor mediating phenotypic changes of osteoblasts. Our findings may provide valuable insights into the mechanisms that underlie bone remodeling in both, healthy and diseased states.