Therapeutic Approach For Inflammatory Diseases Research Articles

A BERT-based approach for identifying anti-inflammatory peptides using sequence information

The use of anti-inflammatory peptides (AIPs) as an alternative therapeutic approach for inflammatory diseases holds great research significance. Due to the high cost and difficulty in identifying AIPs with experimental methods, the discovery and design of peptides by computational methods before the experimental stage have become promising technology. In this study, we present BertAIP, a bidirectional encoder representation from transformers (BERT)-based method for predicting AIPs directly from their amino acid sequence without using any other information. BertAIP implements a BERT model to extract features of a protein, and uses a fully connected feed-forward network for AIP classification. It was constructed and evaluated using the AIP datasets that were reconstructed from the latest Immune Epitope Database. The experimental results showed that BertAIP achieved an accuracy of 0.751 and a Matthews correlation coefficient of 0.451, which were higher than other commonly used methods. The results of the independent test suggested that BertAIP outperformed the existing AIP predictors. In addition, to enhance the interpretability of BertAIP, we explored and visualized the amino acids that the model considered important for AIP prediction. We believe that the BertAIP proposed herein will be a useful tool for large-scale screening and identifying novel AIPs for drug development and therapeutic research related to inflammatory diseases.

Molecular probes for monitoring pyroptosis: design, imaging and theranostic application.

Pyroptosis is a recently discovered process of programmed cell death that is linked with tumor progression and potential treatment strategies. Unlike other forms of programmed cell death, such as apoptosis or necrosis, pyroptosis is associated with pore-forming proteins gasdermin D (GSDMD), which are cleaved by caspase enzymes to form oligomers. These oligomers are then inserted into the cell surface membrane, causing pores to consequently result in rapid cell death. Pyroptosis, in conjunction with immunotherapy, represents a promising avenue for prognostication and antitumor therapy, providing a more precise direction for disease treatment. To gain deeper insight into the mechanisms underlying pyroptosis in real-time, non-invasive and live cell imaging techniques are urgently needed. Non-invasive imaging techniques can enhance future diagnostic and therapeutic approaches for inflammatory diseases, including different types of tumors. This review article discusses various non-invasive molecular probes for detecting pyroptosis, including genetic reporters and nanomaterials. These strategies can enhance scientists' understanding of pyroptosis and help discover personalized and effective ways to treat inflammatory diseases, particularly tumors.

Exploring Inflammasome Complex as a Therapeutic Approach in Inflammatory Diseases

Inflammasomes, a group of multiprotein complexes, are essential in regulating inflammation and immune responses. Several inflammasomes, including nucleotide-binding domain leucine-rich repeat-containing protein 1 (NLRP1), NLRP3, NLRP6, NLRP7, NLRP12, interferon-inducible protein 16 (IFI16), NOD-like receptor family CARD domain-containing protein 4 (NLRC4), absent in melanoma 2 (AIM2), and pyrin, have been studied in various inflammatory diseases. Activating inflammasomes leads to the processing and production of proinflammatory cytokines, such as interleukin (IL)-1β and IL-18. The NLRP3 inflammasome is the most extensively studied and well characterized. Consequently, targeting inflammasomes (particularly NLRP3) with several compounds, including small molecule inhibitors and natural compounds, has been studied as a potential therapeutic strategy. This review provides a comprehensive overview of different inflammasomes and their roles in six inflammatory diseases, including multiple sclerosis, Alzheimer’s disease, Parkinson’s disease, atherosclerosis, type 2 diabetes, and obesity. We also discussed different strategies that target inflammasomes to develop effective therapeutics.

Oleuropein reduces LPS-induced inflammation via stimulating M2 macrophage polarization

Oleuropein (OLEU) is the most prevalent phenolic component in olive varieties, and it has been considered for its powerful antioxidant properties in therapeutic applications. OLEU has anti-inflammatory properties and performs this property by suppressing inflammatory cells' function and reducing oxidative stress caused by various factors. This study investigated the ability of OLEU to polarize LPS-stimulated murine macrophage (MQ) cell RAW 264.7 into M1/M2 macrophages. As a first step, the cytotoxicity effects of OLEU were evaluated on LPS-stimulated RAW 264.7 cells using the thiazolyl blue (MTT) colorimetric test. Then, cytokines production, gene expression (Real-Time PCR), and functions (Nitrite oxide assay and phagocytosis assay) of OLEU-treated LPS-stimulated RAW 264.7 cells were evaluated. Our findings demonstrated that OLEU could reduce nitrite oxide (NO) production in LPS-stimulated RAW 264.7 cells by downregulating the inducible nitric oxide synthase gene expression. Furthermore, OLEU therapy decreases the expression of M1-associated pro-inflammatory cytokines production (IL-12, IFN-γ, and TNF-α) and genes expression (iNOS, TNF-α) while increasing the M2-associated anti-inflammatory gene expression and cytokines production (IL-10, and TGF-β). Based on the result, OLEU may be considered a potential therapeutic approach for inflammatory diseases due to its possible effects on oxidative stress-related factors, cytokine expression and production, and phagocytosis.

Induction of tetraspanin 13 contributes to the synergistic anti-inflammatory effects of parasympathetic and sympathetic stimulation in macrophages

The autonomic nervous system plays an important role in the regulation of peripheral inflammation. Sympathetic nervous activation stimulates inflammatory gene expression and cytokines, whereas parasympathetic nervous activation suppresses the production of inflammatory cytokines by immune cells. However, most studies on the relationship between the autonomic nervous system and immune processes have analyzed a single branch of the autonomic nerves in isolation. Therefore, this study aimed to examine the effects of sympathetic and parasympathetic stimulation on macrophages, which are controlled by autonomic regulation.Macrophages were stimulated with lipopolysaccharide (LPS) to induce TNF-α. Then, the effects of β2 adrenergic receptor and α7 nicotinic acetylcholine receptor activation on TNF-α production were assessed using concentration-dependent assays. RNA-seq data were also used to identify genes whose expression was enhanced by parasympathetic and sympathetic stimulation.The simultaneous activation of β2 adrenergic receptors and α7 nicotinic acetylcholine receptors suppressed LPS-induced TNF-α production in a concentration-dependent manner. Moreover, simultaneous activation of these receptors had synergistic anti-inflammatory effects and induced Tspan13 expression, thereby contributing to anti-inflammatory mechanisms in macrophages.Our study revealed the synergistic anti-inflammatory effects of the parasympathetic and sympathetic stimulation of macrophages. Our results suggest that targeting both sympathetic and parasympathetic signaling is a promising therapeutic approach for inflammatory diseases.

IL-1β Expression of Patients with Chronic Rhinosinusitis is negatively correlated with Lund-Mackay score

Introduction: IL-1β is one of the proinflammatory cytokines which is commonly found in various diseases, including Chronic Rhinosinusitis (CRS). It has been widely targeted as a therapeutic approach for inflammatory diseases. However, study of IL-1β expression and its correlation with CT-Scan grading scores in CRS is still scarce. Objective: To investigate IL-1β expression based on immunohistochemical examination and analyse its correlation with Lund-Mackay score in CRS with and without polyps. Method: This analytic observational study was done on 50 patients: 25 subjects in the CRS with Nasal Polyps (CRSwNP) group and 25 subjects in the CRS without Nasal Polyps (CRSsNP) group. The uncinate process was taken for immunohistochemical examination of IL-1β. Lund-Mackay score was calculated based on CT-Scan of the paranasal sinus. Result: IL-1β expression in CRSsNP (mean=36.38) was significantly higher than that in the CRSwNP (mean=14.62) with p<0.001. Lund-Mackay score in CRSwNP was higher (mean=35.22) compared to CRSnNP group (mean=15.78) with p<0.001. There was a moderate negative correlation (-0.403) between IL-1β expression and Lund-Mackay score (p<0.05). Conclusion: There was a moderate negative correlation between IL-1β expression and Lund-Mackay score. The IL-1β and the Lund-Mackay score in CRSwNP were lower and higher, respectively, than in CRSsNP

Nanostructured Lipid Carrier-Mediated Transdermal Delivery of Aceclofenac Hydrogel Present an Effective Therapeutic Approach for Inflammatory Diseases.

Aceclofenac (ACE), a cyclooxygenase-2 inhibitor, is the derivative of the diclofenac group that has been in use for the symptomatic treatment of systemic inflammatory autoimmune disease, rheumatoid arthritis (RA). Partial solubility, high lipophilic nature, and stability challenge its use in developing topical formulations. Hence, we developed and characterized nanostructured lipid carrier (NLC)–based ACE (ACE-NLC) hydrogel for an efficient transdermal delivery. NLC microemulsion was prepared using different lipids by various methods and was characterized with respect to particle size, zeta potential, surface morphology, and drug encapsulation efficiency. The optimized NLC formulation was incorporated into Carbopol® 940 gel, and this arrangement was characterized and compared with the existing marketed gel (Mkt-gel) formulation to assess in vitro drug release, rheology, texture profile, in vivo skin retention and permeation, and stability. Furthermore, prepared and characterized ACE-loaded NLC formulation was evaluated for skin integrity and fitted in a dermatokinetic model. The results of this study confirmed the spherical shape; smooth morphology and nanometric size attested by Zetasizer and scanning and transmission electron microcopy; and stability of the ACE-NLC formulation. The ACE-NLC-gel formulation showed good rheological and texture characteristics, and better skin distribution in the epidermis and dermis. Moreover, ACE-NLC permeated deeper in the skin layers and kept the skin integrity intact. Overall, NLC-based gel formulation of ACE might be a promising nanoscale lipid carrier for topical application when compared with the conventional Mkt-gel formulation.

Chamaecyparis obtusa (Siebold & Zucc.) Endl. leaf extracts prevent inflammatory responses via inhibition of the JAK/STAT axis in RAW264.7 cells

Ethnopharmacological relevanceChamaecyparis obtusa (Siebold & Zucc.) Endl. (C. obtusa) has been used as folk medicine in East Asia and has been reported to alleviate inflammatory diseases. However, the detailed mechanisms for the anti-inflammatory effects of C. obtusa remain unclear. Aim of the studyAlthough the anti-inflammatory mechanisms of natural products have been studied for decades, it is still important to identify the potential anti-inflammatory effects of natural sources. In this study, we investigated the anti-inflammatory effects and underlying mechanism of C. obtusa leaf extracts. Material &methodsThe cell viability was determined by MTT and crystal violet staining. NO production in the supernatant was measured using Griess reagent. The cell lysates were analyzed by immunoblotting and RT-qPCR. Secreted cytokines were analyzed using ELISA kit and cytokine array kit. mRNA expression from the GSE9632 database set. Z-scores were calculated for each gene and visualized by heat map. ResultsAmong the extracts of C. obtusa obtained with different extraction methods, the 99% ethanol leaf extract (CO99EL) strongly inhibited lipopolysaccharide (LPS)-induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) expression and Janus kinase/signaling transducer and activator of transcription (JAK/STAT) phosphorylation in RAW264.7 cells. In addition, CO99EL strongly inhibited LPS-induced interleukin (IL)-1β, IL-6, IL-27, and C-C motif chemokine ligand (CCL)-1 production and directly inhibited LPS-induced JAK/STAT phosphorylation in RAW264.7 cells. ConclusionsThese findings demonstrate that CO99EL significantly prevents LPS-induced macrophage activation by inhibiting the JAK/STAT axis. Therefore, we suggest the use of C. obtusa extracts as therapeutic approach for inflammatory diseases.

Induction of stable human FOXP3+ Tregs by a parasite-derived TGF-β mimic.

Immune homeostasis in the intestine is tightly controlled by FOXP3+ regulatory T cells (Tregs), defects of which are linked to the development of chronic conditions, such as inflammatory bowel disease (IBD). As a mechanism of immune evasion, several species of intestinal parasites boost Treg activity. The parasite Heligmosomoides polygyrus is known to secrete a molecule (Hp‐TGM) that mimics the ability of TGF‐β to induce FOXP3 expression in CD4+ T cells. The study aimed to investigate whether Hp‐TGM could induce human FOXP3+ Tregs as a potential therapeutic approach for inflammatory diseases. CD4+ T cells from healthy volunteers were expanded in the presence of Hp‐TGM or TGF‐β. Treg induction was measured by flow cytometric detection of FOXP3 and other Treg markers, such as CD25 and CTLA‐4. Epigenetic changes were detected using ChIP‐Seq and pyrosequencing of FOXP3. Treg phenotype stability was assessed following inflammatory cytokine challenge and Treg function was evaluated by cellular co‐culture suppression assays and cytometric bead arrays for secreted cytokines. Hp‐TGM efficiently induced FOXP3 expression (> 60%), in addition to CD25 and CTLA‐4, and caused epigenetic modification of the FOXP3 locus to a greater extent than TGF‐β. Hp‐TGM‐induced Tregs had superior suppressive function compared with TGF‐β‐induced Tregs, and retained their phenotype following exposure to inflammatory cytokines. Furthermore, Hp‐TGM induced a Treg‐like phenotype in in vivo differentiated Th1 and Th17 cells, indicating its potential to re‐program memory cells to enhance immune tolerance. These data indicate Hp‐TGM has potential to be used to generate stable human FOXP3+ Tregs to treat IBD and other inflammatory diseases.

Anti‑inflammatory compounds moracin O and P from Morus alba Linn. (Sohakuhi) target the NF‑κB pathway.

Accumulating evidence suggests that inflammation is linked to multiple pathological processes and induces cellular and molecular damage through the activation of inflammatory signaling pathways, including the NF-κB pathway. The aim of the present study was to identify natural anti-inflammatory products that can target NF-κB activity, in order to establish a novel therapeutic approach for inflammatory diseases. Using a 4T1 breast cancer cell line that expresses the firefly luciferase gene under the control of an NF-κB response element, 112 natural products were tested for their anti-inflammatory properties. Sohakuhi (Morus alba Linn. bark) extract was observed to strongly suppress NF-κB activity without affecting cell viability. To further examine the anti-inflammatory effect of Sohakuhi, tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced cellular damage of human HaCaT keratinocytes was evaluated. While TRAIL triggered the phosphorylation of the p65 subunit of NF-κB, leading to cellular damage in HaCaT cells, treatment with Sohakuhi extract protected HaCaT cells against TRAIL-induced cellular damage. Moreover, Sohakuhi treatment also upregulated the anti-apoptotic proteins Bcl-xL and Bcl-2. Importantly, through chemical fractionation of Sohakuhi extract, moracin O and P were confirmed to mediate its anti-inflammatory effects. Collectively, the present results indicated that Sohakuhi and moracin may represent potential candidates for the development of novel anti-inflammatory drugs.

Quality control and immunomodulatory potential for clinical-grade equine bone marrow-derived mesenchymal stromal cells and conditioned medium

This study aimed to assess the safety and reproducibility of cell therapy for its use in clinical practice. We performed immunophenotypic characterization of equine bone marrow-derived mesenchymal stromal cells (BMMSCs) by flow cytometry using CD90, CD19, CD14, CD105, CD45, and HLA-DR markers (n = 4); GTG banding cytogenetic analysis (n = 3); and microbiological quality control (n = 4). The immunomodulatory potentials of BMMSCs (n = 4) and its conditioned medium (CM, n = 3) were investigated by in vitro lymphocyte inhibition assay using phytohemagglutinin (PHA)-stimulated peripheral blood mononuclear cells (PBMCs). BMMSCs populations isolated from all animals showed high expression of CD90 and CD105, and low expression of CD19, CD4, CD45, and HLA-DR. Of the 60 metaphases analyzed, 5% presented aneuploidy on random chromosomes and no contamination was found based on microbiological analyses. Both treatments significantly inhibited lymphocyte proliferation (> 50%), compared with PHA-stimulated PBMCs (p < 0.0001). These promising results for BMMSCs and CM justify their potential as a therapeutic approach for inflammatory diseases. The techniques used in this study were effective in assessing the quality and determining the minimum criteria for the clinical use of BMMSCs in veterinary medicine.

NLRP3 Inflammasome and Inflammatory Diseases.

Almost all human diseases are strongly associated with inflammation, and a deep understanding of the exact mechanism is helpful for treatment. The NLRP3 inflammasome composed of the NLRP3 protein, procaspase-1, and ASC plays a vital role in regulating inflammation. In this review, NLRP3 regulation and activation, its proinflammatory role in inflammatory diseases, interactions with autophagy, and targeted therapeutic approaches in inflammatory diseases will be summarized.

Soluble syndecan-3 binds chemokines, reduces leukocyte migration in vitro and ameliorates disease severity in models of rheumatoid arthritis

BackgroundSyndecans are heparan sulfate proteoglycans that occur in membrane-bound or soluble forms. Syndecan-3, the least well-characterised of the syndecan family, is highly expressed on synovial endothelial cells in rheumatoid arthritis patients. Here, it binds pro-inflammatory chemokines with evidence for a role in chemokine presentation and leukocyte trafficking into the joint, promoting the inflammatory response. In this study, we explored the role of soluble syndecan-3 as a binder of chemokines and as an anti-inflammatory and therapeutic molecule.MethodsA human monocytic cell line and CD14+ PBMCs were utilised in both Boyden chamber and trans-endothelial migration assays. Soluble syndecan-3 was tested in antigen-induced and collagen-induced in vivo arthritis models in mice. ELISA and isothermal fluorescence titration assays assessed the binding affinities. Syndecan-3 expression was identified by flow cytometry and PCR, and levels of shedding by ELISA.ResultsUsing in vitro and in vivo models, soluble syndecan-3 inhibited leukocyte migration in vitro in response to CCL7 and its administration in murine models of rheumatoid arthritis reduced histological disease severity. Using isothermal fluorescence titration, the binding affinity of soluble syndecan-3 to inflammatory chemokines CCL2, CCL7 and CXCL8 was determined, revealing little difference, with Kds in the low nM range. TNFα increased cell surface expression and shedding of syndecan-3 from cultured human endothelial cells. Furthermore, soluble syndecan-3 occurred naturally in the sera of patients with rheumatoid arthritis and periodontitis, and its levels correlated with syndecan-1.ConclusionsThis study shows that the addition of soluble syndecan-3 may represent an alternative therapeutic approach in inflammatory disease.

Crosstalk between Peroxisome Proliferator-Activated Receptors and Toll-Like Receptors: A Systematic Review.

As one of the four major families of pattern recognition receptors (PRRs), toll like receptors (TLRs) are crucial and important components of the innate immune system. Peroxisome proliferatoractivated receptors (PPARs) with three isoforms are transcription factors classified as a subfamily of nuclear receptor proteins, and are of significant regulatory activity in cellular differentiation, development, metabolism, and tumorigenesis. It is well established that PPARs agonists display anti-inflammatory effects through inhibition of the nuclear factor-kappa B (NF-κB) pathway, a key regulator of immune and inflammatory responses, in a sense that TLRs signaling pathways are mainly toward activation of NF-κB. Through a systematic review of previous studies, we aimed to address and clarify the reciprocal interaction between TLRs and PPARs in hope to find alternative therapeutic approaches for inflammatory diseases. Among the available scientific database, 31 articles were selected for this review. A comprehensive review of this database confirms the presence of a cross-talk between PPARs and TLRs, indicating that not only PPARs stimulation may affect the expression level of TLRs via several mechanisms leading to modulating TLRs activities, but also TLRs have the potential to moderate the expression of PPARs. We, therefore, conclude that, as a key regulator of the innate immune system, the interaction between PPARs and TLRs is a potential therapeutic target in disease treatment.

Immunomodulation by Helminths: Intracellular Pathways and Extracellular Vesicles.

Helminth parasites are masters at manipulating host immune responses, using an array of sophisticated mechanisms. One of the major mechanisms enabling helminths to establish chronic infections is the targeting of pattern recognition receptors (PRRs) including toll-like receptors, C-type lectin receptors, and the inflammasome. Given the critical role of these receptors and their intracellular pathways in regulating innate inflammatory responses, and also directing adaptive immunity toward Th1 and Th2 responses, recognition of the pathways triggered and/or modulated by helminths and their products will provide detailed insights about how helminths are able to establish an immunoregulatory environment. However, helminths also target PRRs-independent mechanisms (and most likely other yet unknown mechanisms and pathways) underpinning the battery of different molecules helminths produce. Herein, the current knowledge on intracellular pathways in antigen presenting cells activated by helminth-derived biomolecules is reviewed. Furthermore, we discuss the importance of helminth-derived vesicles as a less-appreciated components released during infection, their role in activating these host intracellular pathways, and their implication in the development of new therapeutic approaches for inflammatory diseases and the possibility of designing a new generation of vaccines.

Metabolic features of macrophages in inflammatory diseases and cancer

Macrophages are now considered to be important players in various inflammatory diseases as well as tumor progression. Emerging evidence reveals that macrophage metabolic features are deeply associated with their immune functions. Understanding the interaction between cellular metabolism and immune signaling pathways in macrophages can help us to develop appropriate therapeutic approaches for inflammatory diseases. In this review, we briefly summarize key metabolic features of M1 and M2 macrophages as well as signaling interactions between major metabolic molecules with TLRs and NLRs. Current knowledges of cellular metabolism are focused on macrophages in various disease situations including sepsis, atherosclerosis, obesity, tuberculosis and cancer. Novel insights and present targets for regulating macrophage metabolism are also discussed.

Central serotonin attenuates LPS-induced systemic inflammation

Serotonin (5-HT) is a neuromodulator involved in several central-mediated mechanisms, such as endocrine processes, behavior, and sleep. Dysfunction of the serotonergic system is mainly linked to psychiatric disorders, but emerging evidence suggests that immune system activation may also alter brain 5-HT signaling. However, whether central 5-HT modulates systemic inflammation (SI) remains unknown. For this purpose, male Wistar rats (280–350g, 8–9weeks) were submitted to the experimental protocols beginning between 9 and 10AM with the performance of injections. The animals were housed at controlled conditions [temperature (25±1°C), light (06:00–18:00) and humidity (60–65%)]. Thus, we measured 5-HT and its metabolite 5-hydroxyindole-3-acetic acid (5-HIAA) in the anteroventral preoptic region [(AVPO) – the hierarchically most important region for body temperature (Tb) control] during lipopolysaccharide (LPS)-induced SI. We also combined LPS (100μg/kg) treatment with intracerebroventricular (icv) injection of 5-HT (5, 10 and 40μg/μL) and measured Tb (“hallmark” of SI), AVPO prostaglandin E2 [(PGE2) – an essential mediator of fever] and prostaglandin D2 [(PGD2) – a cryogenic mediator], plasma corticosterone [(CORT) – a stress marker with an endogenous anti-inflammatory effect] and interleukin-6 [(IL-6) – an immune mediator] levels. Detection limits of PGE2, PGD2, CORT and IL-6 assays were 39.1–2500pg/mL, 19.5–2500pg/mL, 0.12–2000μg/dL, and 0.125–8ng/mL, respectively. We also assessed tail skin temperature [used to calculate heat loss index (HLI)] to assess a key thermoeffector mechanism. As expected we observed LPS-induced increases in Tb, AVPO PGE2 (whereas PGD2 remained unchanged), plasma CORT and IL-6 levels, as well as a decrease in HLI. These changes were accompanied by reduced levels of AVPO 5-HT and 5-HIAA. Furthermore, we also observed a negative correlation between 5-HT and plasma CORT levels. Moreover, icv 5-HT (5, 10 and 40μg/μL) microinjection caused a U-shaped dose-response curve in LPS fever, in which the intermediate dose reduced the febrile response. Icv 5-HT (10μg/μL) microinjection prevented the LPS-induced increases in AVPO PGE2 (whereas not altering PGD2), plasma CORT and IL-6 levels, as well as preventing reduced HLI. Our data are consistent with the notion that AVPO 5-HT synthesis is down-regulated during SI, favoring AVPO PGE2 synthesis and consequently potentiating the immune response. These results reveal a novel effect of central 5-HT as an anti-inflammatory neuromodulator that may take place during psychiatric disorder treatment with 5-HT reuptake inhibitors as well as suggesting that 5-HT modulation per se is a potential therapeutic approach for inflammatory diseases.

Discovery of a novel prolyl-tRNA synthetase inhibitor and elucidation of its binding mode to the ATP site in complex with l-proline

Prolyl-tRNA synthetase (PRS) is a member of the aminoacyl-tRNA synthetase family of enzymes and catalyzes the synthesis of prolyl-tRNAPro using ATP, l-proline, and tRNAPro as substrates. An ATP-dependent PRS inhibitor, halofuginone, was shown to suppress autoimmune responses, suggesting that the inhibition of PRS is a potential therapeutic approach for inflammatory diseases. Although a few PRS inhibitors have been derivatized from natural sources or substrate mimetics, small-molecule human PRS inhibitors have not been reported. In this study, we discovered a novel series of pyrazinamide PRS inhibitors from a compound library using pre-transfer editing activity of human PRS enzyme. Steady-state biochemical analysis on the inhibitory mode revealed its distinctive characteristics of inhibition with proline uncompetition and ATP competition. The binding activity of a representative compound was time-dependently potentiated by the presence of l-proline with Kd of 0.76 nM. Thermal shift assays demonstrated the stabilization of PRS in complex with l-proline and pyrazinamide PRS inhibitors. The binding mode of the PRS inhibitor to the ATP site of PRS enzyme was elucidated using the ternary complex crystal structure with l-proline. The results demonstrated the different inhibitory and binding mode of pyrazinamide PRS inhibitors from preceding halofuginone. Furthermore, the PRS inhibitor inhibited intracellular protein synthesis via a different mode than halofuginone. In conclusion, we have identified a novel drug-like PRS inhibitor with a distinctive binding mode. This inhibitor was effective in a cellular context. Thus, the series of PRS inhibitors are considered to be applicable to further development with differentiation from preceding halofuginone.

Diet and the Anti-inflammatory Effect of Heat Shock Proteins

Stress proteins or heat shock proteins (HSPs) have a critical role in gut health and immune regulation. They have a functional significance as molecular chaperones for cell skeleton proteins and intercellular tight junction proteins. Herewith HSPs ensure gut epithelium integrity and effective intestinal barrier function. In addition, stress protein molecules such as HSP70 are a target for anti-inflammatory regulatory T cells (Tregs). Inflamed sites in the body feature inflammatory-stress induced enhanced levels of HSPs, which enable the immune system to target Tregs selectively to sites of inflammation. We have shown in experimental models of inflammatory diseases that both microbial HSP and endogenous (self) HSP molecules are capable of inducing the expansion of disease suppressive Tregs. Since the gut associated lymphoid tissue (GALT) is well poised towards the induction of regulation and tolerance, we set out to promote HSP expression and induction of Tregs in the gut lymphoid tissues by the oral administration of HSP co-inducing compounds. For the identification, selection and characterization of such compounds we have developed assay systems, such as reporter cell-lines, HSP specific T cell hybridomas and a transgenic mouse model (expression a HSP specific T cell receptor). The introduction of HSP coinducers into the diet constitutes a novel food based preventive or possibly even therapeutic approach in inflammatory diseases.

Synthesis and docking studies of 2,4,6-trihydroxy-3-geranylacetophenone analogs as potential lipoxygenase inhibitor.

The natural product molecule 2,4,6-trihydroxy-3-geranyl-acetophenone (tHGA) isolated from the medicinal plant Melicope ptelefolia was shown to exhibit potent lipoxygenase (LOX) inhibitory activity. It is known that LOX plays an important role in inflammatory response as it catalyzes the oxidation of unsaturated fatty acids, such as linoleic acid to form hydroperoxides. The search for selective LOX inhibitors may provide new therapeutic approach for inflammatory diseases. Herein, we report the synthesis of tHGA analogs using simple Friedel-Craft acylation and alkylation reactions with the aim of obtaining a better insight into the structure-activity relationships of the compounds. All the synthesized analogs showed potent soybean 15-LOX inhibitory activity in a dose-dependent manner (IC50 = 10.31–27.61 μM) where compound 3e was two-fold more active than tHGA. Molecular docking was then applied to reveal the important binding interactions of compound 3e in soybean 15-LOX binding site. The findings suggest that the presence of longer acyl bearing aliphatic chain (5Cs) and aromatic groups could significantly affect the enzymatic activity.