PEPITEM Treatment Ameliorates EAE in Mice by Reducing CNS Inflammation, Leukocyte Infiltration, Demyelination, and Proinflammatory Cytokine Production.

To investigate the effect of the therapeutic treatment of the immunopeptide, peptide inhibitor of trans-endothelial migration (PEPITEM) on the severity of disease in a mouse model of experimental autoimmune encephalomyelitis (EAE) as a model for human multiple sclerosis (MS), a series of experiments were conducted. Using C57BL/6 female mice, we dosed the PEPITEM in the EAE model via IP after observing the first sign of inflammation. The disease was induced using MOG35-55 and complete Freund's adjuvants augmented with pertussis toxin. The EAE score was recorded daily until the end of the experiment (21 days). The histological and immunohistochemistry analysis was conducted on the spinal cord sections. A Western blot analysis was performed to measure the protein concentration of MBP, MAP-2, and N-Cadherin, and ELISA kits were used to measure IL-17 and FOXP3 in the serum and spinal cord lysate. The therapeutic treatment with PEPITEM reduced the CNS infiltration of T cells, and decreased levels of the protein concertations of MBP, MAP-2, and N-Cadherin were observed, in addition to reduced concertations of IL-17 and FOXP3. Using PEPITEM alleviated the severity of the symptoms in the EAE model. Our study revealed the potential of PEPITEM to control inflammation in MS patients and to reduce the harmful effects of synthetic drugs.

Molecular mechanism of interleukin-17A regulating airway epithelial cell ferroptosis based on allergic asthma airway inflammation.

Interleukin-17A (IL-17A) levels are elevated in patients with asthma. Ferroptosis has been identified as the non-apoptotic cell death type associated with asthma. Data regarding the relation of ferroptosis with asthma and the effect of IL-17A on modulating ferroptosis in asthma remain largely unclear. The present work focused on investigating the role of IL-17A in allergic asthma-related ferroptosis and its associated molecular mechanisms using public datasets, clinical samples, human bronchial epithelial cells, and an allergic asthma mouse model. We found that IL-17A was significantly upregulated within serum in asthma cases. Adding IL-17A significantly increased ferroptosis within human bronchial epithelial cells (BEAS-2B). In ovalbumin (OVA)-induced allergic asthmatic mice, IL-17A regulated and activated lipid peroxidation induced ferroptosis, whereas IL-17A knockdown effectively inhibited ferroptosis in vivo by protection of airway epithelial cells via the xCT-GSH-GPX4 antioxidant system and reduced airway inflammation. Mouse mRNA sequencing results indicated that the tumor necrosis factor (TNF) pathway was the differential KEGG pathway in the OVA group compared to healthy controls and the OVA group compared to the IL-17A knockout OVA group. We further used N-acetylcysteine (TNF inhibitor) to inhibit the TNF signaling pathway, which was found to protect BEAS-2B cells from IL-17A induced lipid peroxidation and ferroptosis damage. Our findings reveal a novel mechanism for the suppression of ferroptosis in airway epithelial cells, which may represent a new strategy for the use of IL-17A inhibitors against allergic asthma.

Ethanol extract of Herpetospermum caudigerum Wall ameliorates psoriasis-like skin inflammation and promotes degradation of keratinocyte-derived ICAM-1 and CXCL9.

OBJECTIVE: To explore whether the ethanol extract of Herpetospermum caudigerum Wall (EHC), a Xizang medicinal plant traditionally used for treating liver diseases, can improve imiquimod-induced psoriasis-like skin inflammation. METHODS: Immunohistochemistry and immunofluorescence staining were used to determine the effects of topical EHC use in vivo on the skin pathology of imiquimod-induced psoriasis in mice. The protein levels of interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and interleukin-17A (IL-17A) in mouse skin samples were examined using immunohistochemical staining. In vitro, IFN-γ-induced HaCaT cells with or without EHC treatment were used to evaluate the expression of keratinocyte-derived intercellular cell adhesion molecule-1 (ICAM-1) and chemokine CXC ligand 9 (CXCL9) using Western blotting and reverse transcription-quantitative polymerase chain reaction. The protein synthesis inhibitor cycloheximide and proteasome inhibitor MG132 were utilized to validate the EHC-mediated mechanism underlying degradation of ICAM-1 and CXCL9. RESULTS: EHC improved inflammation in the imiquimod-induced psoriasis mouse model and reduced the levels of IFN-γ, TNF-α, and IL-17A in psoriatic lesions. Treatment with EHC also suppressed ICAM-1 and CXCL9 in epidermal keratinocytes. Further mechanistic studies revealed that EHC suppressed keratinocyte-derived ICAM-1 and CXCL9 by promoting ubiquitin-proteasome-mediated protein degradation rather than transcriptional repression. Seven primary compounds including ehletianol C, dehydrodiconiferyl alcohol, herpetrione, herpetin, herpetotriol, herpetetrone and herpetetrol were identified from the EHC using ultra-performance liquid chromatography-quadrupole-time of flight-mass spectrometry. CONCLUSION: Topical application of EHC ameliorates psoriasis-like skin symptoms and improves the inflammation at the lesion sites. Please cite this article as: Zhong Y, Zhang BW, Li JT, Zeng X, Pei JX, Zhang YM, Yang YX, Li FL, Deng Y, Zhao Q. Ethanol extract of Herpetospermum caudigerum Wall ameliorates psoriasis-like skin inflammation and promotes degradation of keratinocyte-derived ICAM-1 and CXCL9. J Integr Med. 2023; 21(6): 584-592.

Exploring the mechanism of the Fructus Mume and Rhizoma Coptidis herb pair intervention in Ulcerative Colitis from the perspective of inflammation and immunity based on systemic pharmacology.

PURPOSE: Ulcerative Colitis (UC) is a chronic nonspecific inflammatory disease of the colon and rectum. Fructus Mume (FM) and Rhizoma Coptidis (RC) exert effects on inflammatory and immune diseases. We evaluated the hypothesis of the FM and RC (FM-RC) herb pair remedy in alleviating dextran sulfate sodium (DSS)-induced colitis, through network pharmacology-based analyses, molecular docking, and experimental validation. METHODS: The Traditional Chinese medicine systematic pharmacology analysis platform(TCMSP) and Swiss database were used to predict potential targets of FM-RC and the GeneCards database was utilized to collect UC genes. Cytoscape software was used to construct and analyze the networks, and DAVID was utilized to perform enrichment analysis. AutoDock software was used to dock the core chemical components of the FM-RC herb pair with key UC targets. Animal experiments were performed to validate the prediction results and general conditions and body weight were observed. Pathological changes in colon tissue were observed by staining with hematoxylin and eosin. The levels of TNF-α, IL-8, IL-17, and IL-4 in serum and colon tissue were detected by ELISA. RESULTS: Eighteen effective components of the herb couple were screened, and their potential therapeutic targets in the treatment of UC were acquired from 110 overlapped targets. GO and KEGG analyses revealed that these targets were highly correlated with protein autophosphorylation, plasma membrane, ATP binding, cancer pathways, the PI3K-AKt signaling pathway, and the Rap1 signaling pathway. Molecular docking established the core protein interactions with compounds having a docking energy < 0 kJ·mol-1, indicating the core active components had strong binding activities with the core targets. FM-RC herb pair relieved pathological indicators and reduced the concentration of TNF-α, IL-8, and IL-17 and increased IL-4 levels in the serum and colon tissues of UC rats. CONCLUSION: Collectively, FM-RC herb pair administration alleviated UC. These beneficial effects targeted MAPK1 signaling related to inflammation and immunity, which provided a basis for a better understanding of FM-RC in the treatment of UC.

Complement System Inhibition Modulates the Inflammation Induced by the Venom of Premolis semirufa, an Amazon Rainforest Moth Caterpillar.

The caterpillar of the Premolis semirufa moth, commonly called Pararama, is found in the Brazilian Amazon region. Contact with the hairs can cause a chronic inflammatory reaction, termed "pararamosis". To date, there is still no specific treatment for pararamosis. In this study, we used a whole human blood model to evaluate the involvement of the complement in the proinflammatory effects of P. semirufa hair extract, as well as the anti-inflammatory potential of complement inhibitors in this process. After treatment of blood samples with the P. semirufa hair extract, there was a significant increase in the generation of soluble terminal complement complex (sTCC) and anaphylatoxins (C3a, C4a, and C5a), as well as the production of the cytokines TNF-α and IL-17 and the chemokines IL-8, RANTES, MIG, MCP-1, and IP-10. The inhibition of C3 with compstatin significantly decreased IL-17, IL-8, RANTES, and MCP-1 production. However, the use of the C5aR1 antagonist PMX205 promoted a reduction in the production of IL-8 and RANTES. Moreover, compstatin decreased CD11b, C5aR1, and TLR2 expression induced by P. semirufa hair extract in granulocytes and CD11b, TLR4, and TLR2 in monocytes. When we incubated vascular endothelial cells with extract-treated human plasma, there was an increase in IL-8 and MCP-1 production, and compstatin was able to decrease the production of these chemokines. C5aR1 antagonism also decreased the production of MCP-1 in endothelial cells. Thus, these results indicate that the extract of the Pararama bristles activates the complement system and that this action contributes to the production of cytokines and chemokines, modulation of the expression of surface markers in leukocytes, and activation of endothelial cells.

Effect of baricitinib in regulating programmed death 1 and ligand programmed cell death ligand 1 through JAK/STAT pathway in psoriasis.

OBJECTIVES: Psoriasis is a chronic infectious skin disease triggered by an autoimmune process involving T-cell-mediated hyper-proliferation of keratinocytes. The objective of this study is to assess the modulation of programmed death 1 (PD-1) and its ligand programmed cell death ligand 1 (PD-L1) through JAK/STAT pathway during the development of a psoriasis-like disease by both in vitro and in vivo model. Baricitinib, a known inhibitor of JAK1 and JAK2, was used to study the impact on PD-1 and PD-L1. MATERIALS AND METHODS: Human peripheral blood mononuclear cells (PBMC) were stimulated with either anti-CD3/CD28 or PMA/Ionomycin, to modulate level of PD-1 and PD-L1 under psoriasis-like condition. Interferon-gamma (IFNγ) was used to treat HaCaT cells to mimic the diseased keratinocytes found in Psoriatic patients. Psoriasis was induced with Imiquimod (IMQ) in animal model to study the cross-talk between different cell types and pathways. RESULTS: Expression levels of PD-1 and PD-L1 in PBMC, and secretion of cytokines, namely tumor necrosis factor-α (TNFα), IFNγ, interleukin (IL)-6, and IL-1 ß, were down-regulated on treatment with baricitinib. Further, in IFNγ-treated HaCaT cells (keratinocytes) mRNA levels of KRT-17 and PD-L1 were up-regulated.). Interestingly, in IFNγ-treated HaCat cells baricitinib decreased the levels of inflammatory cytokines such as IL-1 ß, IL-6, and TNFα along with KRT-17 and PD-L1. On IFNγ-treatment. Data from both PBMC and HaCaT suggest an anti-inflammatory role for this compound. Accordingly, baricitinib was able to alleviate disease symptom in IMQ induce mice model of psoriasis. As a consequence of baricitinib treatment down-regulation of p-STAT3, PD- and PD-L1 expression levels were observed. CONCLUSION: This study demonstrates a crosstalk between JAK/STAT and PD-1/PD-L1 pathways. It also demonstrates that cytokines such as IFNγ and IL-17 are down-regulated by baricitinib. We believe decreased expressions of PD-1 and PD-L1 may be a consequence of baricitinib-induced down-regulation of IFNγ and IL-17. More importantly, our data from the acute model of psoriasis indicates that PD-L1 behaves as a T-cell-associated T-cell-associated surrogate activation marker rather than immunosuppressive marker in early phase of psoriasis. Therefore it does not exhibit a causal relationship to disease.

Curcumin alleviates rheumatoid arthritis progression through the phosphatidylinositol 3-kinase/protein kinase B pathway: an in vitro and in vivo study.

Rheumatoid arthritis (RA) is a chronic, systemic autoimmune disease characterized by synovial inflammation and joint bone and cartilage destruction. Curcumin can improve joint inflammation in rats with arthritis and inhibit synovial revascularization and abnormal proliferation of fibroblasts. However, it is unclear whether curcumin affects the RA progression. The TNF-α-stimulated primary RA fibroblast-like synoviocytes (RA-FLS) and SV-40 transformed MH7A cells were used as the in vitro model of RA. A mouse model of collagen-induced arthritis (CIA) was used as the in vivo model. The effects of curcumin on cell proliferation, apoptosis, migration, invasion, and inflammatory response were assessed by colony formation, flow cytometry, wound scratch, Transwell assays, and western blotting analysis. Arthritis index scores and degree of paw swelling in mice were assessed to evaluate RA. Curcumin inhibited the TNF-α-induced proliferation, migration, invasion of MH7A and RA-FLS cells and promoted cell apoptosis. Administration with curcumin reversed the CIA-induced increase in arthritis scores, hind paw edema, and loss of appetite, while these effects were rescued by insulin-like growth factor 1, the upstream cytokine of PI3K/AKT. Moreover, curcumin suppressed the inflammatory response by reducing TNF-α, IL-6, and IL-17 secretion in CIA-stimulated mice. Curcumin has an excellent anti-RA effect in vivo and in vitro, which is exerted by inhibiting the expression of pro-inflammatory factors TNF-a, IL-6 and IL-17 and inhibiting the activation of PI3K/AKT signaling pathway. Thus, curcumin may be a promising candidate for anti-RA treatment.

Interleukin 17A infusion has no acute or long-term hypertensive action in conscious unrestrained male mice.

Interleukin 17A (IL-17A) is a candidate mediator of inflammation-driven hypertension, but its direct effect on blood pressure is obscure. The present study was designed to test the hypothesis that systemic IL-17A concentration-dependently increases blood pressure and amplifies ANGII-induced hypertension in mice. Blood pressure was measured by indwelling chronic femoral catheters before and during IL-17A infusion w/wo angiotensin II (ANGII, 60ng/kg/min) in male FVB/n mice. Baseline blood pressure was recorded, and three experimental series were conducted: (1) IL-17A infusion with increasing concentrations over 6 days (two series with IL-17A from two vendors, n = 11); (2) ANGII infusion with IL-17A or vehicle for 9 days (n = 11); and (3) acute bolus infusions with four different concentrations (n = 5). Plasma IL-17A and IL-6 concentrations were determined by ELISA. Mean arterial and systolic blood pressures (MAP, SBP) decreased significantly after IL-17A infusion while heart rate was unchanged. In these mice, plasma IL-17A and IL-6 concentrations increased up to 3500- and 2.4-fold, respectively, above baseline. ANGII infusion increased MAP (~ 25 mmHg) and co-infusion of IL-17A attenuated ANGII-induced hypertension by 4.0 mmHg. Here, plasma IL-17A increased 350-fold above baseline. Acute IL-17A bolus infusion did not change blood pressure or heart rate. IL-17A receptor and IL-6 mRNAs were detected in aorta, heart, and kidneys of mice after IL-17A infusion. Nonphysiologically high concentrations of IL-17A reduce baseline blood pressure and increase IL-6 formation in male FVB/n mice. It is concluded that IL-17A is less likely to drive hypertension as the sole cytokine mediator during inflammation in vivo.

KT2 alleviates ulcerative colitis by reducing Th17 cell differentiation through the miR-302c-5p/STAT3 axis.

BACKGROUND: The abnormal differentiation of Th17 cells aggravates ulcerative colitis (UC). Antimicrobial peptides (AMPs) exert pivotal protection functions against UC. KT2 is a cationic AMP that mediates colon cancer development. However, KT2's function in UC remains unclear. METHODS: The UC mouse model was induced by administering 2.5% dextran sulfate sodium, and the mice were given an enema of KT2. KT2's function in UC and Th17 cell differentiation in vivo was evaluated through various molecular experiments. The KT2's function in Th17 cell differentiation in vitro was evaluated by the proportion of CD4+ IL-17+ T cells, IL-17 levels, and RORγt expression levels. Meanwhile, the mechanism was assessed through quantitative real-time PCR, various loss-of-function assays, and dual-luciferase reporter gene assay. RESULTS: KT2 restrained Th17 cell differentiation in both in vivo and in vitro UC models and slowed the UC process. KT2 elevated miR-302c-5p expression, as well as restrained Th17 cell differentiation by increasing miR-302c-5p. Meanwhile, miR-302c-5p interacted with the signal transducer and activator of transcription 3 (STAT3) and negatively regulated its expression. Furthermore, our data revealed that KT2 restrained the activation of STAT3 by elevating miR-302c-5p, thereby inhibiting Th17 cell differentiation. CONCLUSION: KT2 alleviates UC by repressing Th17 cell differentiation through the miR-302c-5p/STAT3 axis.

Design and synthesis of the 4H-chromenone derivatives against psoriasis.

On basis of Quercetin moiety, two series of 20 new compounds were designed and synthesized accordingly in this study, and their anti-inflammatory activities in vitro and in vivo were evaluated. At last, compound 8A2: 3- (1- (2- (4- (5-bromo-2-chlorobenzoyl) piperazin-1-yl) ethyl)-1H-1,2,3-triazol-4-yl) methoxy)-5,7-dimethoxy-2-(3,4,5-trimethoxyphenyl)-4H-chromen-4-one with low toxicity was found the best one for inhibiting of NO. Meanwhile, this compound could significantly inhibit the expression of IL-6 (Interleukin-6), TNF-α (Tumor necrosis factor-α) and IL-17 (Interleukin-17), and also significantly down-regulate IL-17 mRNA psoriasis model in vitro. Further studies were performed to establish mouse psoriasis model induced by Imiquimod (IMQ), and the preliminary mechanism indicated that compound 8A2 may alleviate mouse psoriasis through obstructed the JAK1/2-STAT1/3 pathway. This study should be provide a basis for further study of effective treatment of psoriasis.

Dihydroartemisinin targets fibroblast growth factor receptor 1 (FGFR1) to inhibit interleukin 17A (IL-17A)-induced hyperproliferation and inflammation of keratinocytes.

Psoriasis is a common chronic immune-mediated disease that often has a serious negative impact on the physical and mental health of patients. Dihydroartemisinin (DHA) is a drug with anti-fibrotic and anti-inflammatory effects that may be involved in the autoimmune regulation of immune diseases. However, the effects of DHA on psoriasis have not been reported comprehensively. Therefore, the aim of this study was to investigate the effect of DHA on abnormal proliferation and inflammation of epidermal keratinocyte cells in psoriasis and its mechanism of action. IL-17A-induced human epidermal keratin-forming cells (HaCaT) were used as a model. And after induction exposure to different concentrations of DHA, CCK-8, EDU staining, wound healing and Western blotting were performed to assess cell viability, proliferation, migration, differentiation and inflammatory factors, respectively. Subsequently, agonists of fibroblast growth factor receptor 1 (FGFR1) were added and the above experiments were repeated. The results showed that DHA obviously inhibited IL-17A-induced hyperproliferation, migration and expression of inflammatory factors in HaCaT cells. Furthermore, FGFR1 was highly expressed in IL-17A-induced HaCaT cells, and DHA inhibited its expression. However, the inhibitory effect of DHA on IL-17A-induced HaCaT cells was reversed after the addition of FGFR1 agonist. In conclusion, DHA could inhibit IL-17A-induced hyperproliferation and inflammation of keratinocytes by targeting FGFR1, which also provided a new target for the treatment of psoriasis.

[Pharmacodynamic mechanism of Tibetan medicine Liurui Capsules on experimental autoimmune uveitis in rats based on network pharmacology and animal experiments].

By integrating network pharmacology and animal experiments, we studied the pharmacodynamic mechanism of the Tibetan medicine Liurui Capsules in the treatment of experimental autoimmune uveitis(EAU). The active ingredients and targets of Liurui Capsules were searched against the Encyclopedia of Traditional Chinese Medicine(ETCM), Bioinformatics Analysis Tool for Molecular Mechanism of Traditional Chinese Medicine(BATMAN-TCM), and relevant literatures. The EAU-related targets were obtained from Gene Expression Omnibus(GEO), GeneCards, Online Mendelian Inheritance in Man(OMIM), and Therapeutic Target Database(TTD). The common targets shared by Liurui Capsules and EAU were identified, and the protein-protein interaction(PPI) network was established via STRING. Gene Ontology(GO) annotation and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis were conducted via g: Profiler. The rat model of EAU was induced by interphotoreceptor retinoid-binding protein(IRBP) and treated with Liurui Capsules. The inflammatory response of anterior segment and the pathological morphology of retina were observed. The mRNA and protein levels of delta-like ligand 4(DLL4), Notch1, interleukin-17(IL-17), and tumor necrosis factor-alpha(TNF-α) were determined by real-time quantitative PCR(q-PCR) and Western blot, respectively. The network pharmacology analysis predicted 51 common targets of Liurui Capsules and EAU, which were mainly involved in IL-17, TNF, and nuclear factor-kappa B(NF-κB) signaling pathways, as well as liposome receptors and other biological processes. Compared with the control group, the modeling of EAU caused inflammatory changes in the anterior segment and retina and up-regulated mRNA and protein levels of DLL4, Notch1, IL-17, and TNF-α in ocular tissue. Compared with the model group, Liurui Capsules reduced the inflammatory reaction of anterior segment and retina and down-regulated the mRNA and protein levels of DLL4, Notch1, IL-17, and TNF-α. Liurui Capsules can down-regulate the expression of the proteins involved in DLL4/Notch1/IL-17 signaling pathway in ocular tissue and alleviate the ocular inflammation, which may be one of the mechanisms of Liurui Capsules in the treatment of EAU.

A Michael Acceptor Analogue, SKSI-0412, Down-Regulates Inflammation and Proliferation Factors through Suppressing Signal Transducer and Activator of Transcription 3 Signaling in IL-17A-Induced Human Keratinocyte.

The activation of signal transducer and activator of transcription 3 (STAT3), as well as up-regulation of cytokines and growth factors to promote STAT3 activation, have been found in the epidermis of psoriatic lesions. Recently, a series of synthetic compounds possessing the Michael acceptor have been reported as STAT3 inhibitors by covalently binding to cysteine of STAT3. We synthesized a Michael acceptor analog, SKSI-0412, and confirmed the binding affinity between STAT3 and SKSI-0412. We hypothesized that the SKSI-0412 can inhibit interleukin (IL)-17A-induced inflammation in keratinocytes. The introduction of IL-17A increased the phosphorylation of STAT3 in keratinocytes, whereas the inactivation of STAT3 by SKSI-0412 reduced IL-17A-induced STAT3 phosphorylation and IκBζ expression. In addition, human ß defensin-2 and S100A7, which are regulated by IκBζ, were significantly decreased with SKSI-0412 administration. We also confirmed that SKSI-0412 regulates cell proliferation, which is the major phenotype of psoriasis. Based on these results, we suggest targeting STAT3 with SKSI-0412 as a novel therapeutic strategy to regulate IL-17A-induced psoriatic inflammation in keratinocytes.

Shikonin inhibits CEBPD downregulation in IL­17­treated HaCaT cells and in an imiquimod­induced psoriasis model.

Psoriasis is a chronic inflammatory skin disease characterized by well­defined scaly papules and plaques. Interleukin (IL)­17 is involved in its pathogenesis and promotes the proliferation of epidermal keratinocytes through signal transducer and activator of transcription 3 (STAT3) activation. Shikonin, a natural naphthoquinone isolated from Lithospermum erythrorhizon, possesses anti­inflammatory and immunosuppressive properties and can suppress IL­17­induced vascular endothelial growth factor expression by inhibiting the JAK/STAT3 pathway. In the present study, MTS, iCELLigence and RT­qPCR were used to determine the optimal concentration and duration of IL­17 or shikonin acting on HaCaT cells. The changes in the expression levels of genes associated with the IL­6/STAT3 pathway in differentially treated cells were analyzed via RT2Profiler™ PCR Array. Small interfering RNA was used to silence the expression levels of the target gene CCAAT/enhancer­binding protein δ (CEBPD). Western blotting and immunohistochemistry were used to evaluate the effect of shikonin on imiquimod­induced psoriasis in mice and the expression levels of CEBPD. Shikonin reversed IL­17­mediated downregulation of the tumor suppressor CEBPD in HaCaT cells. Moreover, low levels of CEBPD in the imiquimod­induced mouse model of psoriasis were restored by shikonin treatment, which ameliorated excessive keratinocyte proliferation. Taken together, these findings suggest that CEBPD plays a key role in the pathogenesis of psoriasis and can be targeted by shikonin as a potential therapeutic strategy.

Quercetin, a Plant Polyphenol, Has Potential for the Prevention of Bone Destruction in Rheumatoid Arthritis.

We investigated the immune-regulatory function of quercetin, in interleukin (IL)-17-produced osteoclastogenesis in rheumatoid arthritis (RA). RA fibroblasts-like synoviocytes (RA-FLS) were stimulated with IL-17, and the mRNA expression and secretion of receptor activator of nuclear factor kappa-B ligand (RANKL) were detected by real-time polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. CD14+ monocytes (osteoclast precursors) were stimulated with IL-17, RANKL, with/without quercetin, and tartrate-resistant acid phosphatase activity was evaluated to assess osteoclast differentiation. Osteoclast differentiation was investigated after coculturing IL-17-stimulated RA-FLS and Th17 cells with monocytes. CD4+ T cells were cocultured with quercetin under Th17-inducing conditions, and their differentiation to Th17 cells and Treg cells was determined by flow cytometry analysis. We found that IL-17 stimulated RA-FLS to produce RANKL and quercetin decreased the IL-17-induced RANKL protein levels. Quercetin decreased the IL-17-produced activation of mammalian target of rapamycin, extracellular signal-regulated kinase and inhibitor of kappa B-alpha. When monocytes were stimulated with IL-17, macrophage colony-stimulating factor or RANKL, mature osteoclasts were formed, and quercetin decreased this osteoclastogenesis. When monocytes were cultured with IL-17-prestimulated RA-FLS or Th17 cells, osteoclasts were produced, and quercetin decreased this osteoclast differentiation. In Th17-differentiation conditions, quercetin suppressed Th17 cell and the production of IL-17, but quercetin did not affect Treg cells. Quercetin inhibits IL-17-stimulated RANKL production in RA-FLS and IL-17-stimulated osteoclast formation. Quercetin reduces Th17 differentiation. Quercetin could be an additional therapeutic option for bone destructive processes in RA.

Vitamin D attenuates human gingival fibroblast inflammatory cytokine production following advanced glycation end product interaction with receptors for AGE.

BACKGROUND AND OBJECTIVES: Vitamin D [1,25(OH)2 D3 or 1,25D3] is critical in musculoskeletal health, inflammation, immune response, and glucose metabolism. Patients with vitamin D deficiency may be at higher risk of diabetes and periodontitis. Diabetic patients exhibit exacerbated inflammation and more periodontal destruction. Advanced glycation end products (AGEs), formed during diabetic hyperglycemia, activate inflammatory pathways in periodontitis. Human gingival fibroblasts (HGFs) express receptors for AGEs (RAGEs) and can contribute to inflammation. OBJECTIVES: Determine whether glycated human serum albumin (G-HSA) augments HGF IL-6 and IL-8 production, and whether treatment with 1,25D3 attenuates cytokine production following stimulation with G-HSA + IL-1ß and/or IL-17. MATERIAL AND METHODS: HGFs were incubated ±G-HSA or normal human serum albumin (HSA), ±IL-1ß and/or IL-17, ±1,25D3. Cytokines were measured by ELISA. Neutralizing anti-RAGE was used to assess AGE-RAGE interaction. Endotoxin was measured using the ToxinSensor™ System. Data were expressed as mean ± standard deviation and analyzed using a one-way analysis of variance (ANOVA) and Scheffe's F procedure for post hoc comparisons. RESULTS: G-HSA or IL-1ß, but not HSA, significantly stimulated IL-6 and IL-8 production. G-HSA or HSA when combined with IL-1ß or IL-1ß + IL-17 synergistically stimulated IL-6 and IL-8. Neutralizing anti-RAGE inhibited IL-6 and IL-8 produced by cells stimulated with IL-1ß + G-HSA but not (+HSA). Synergism caused by HSA did not appear to be mediated by endotoxin since its levels in G-HSA and HSA were not sufficient to stimulate fibroblasts. Vitamin D inhibited IL-6 and IL-8 production stimulated by G-HSA or HSA + IL-1ß or IL-1ß + IL-17. CONCLUSIONS: Results suggest that the "perioprotective" effects of vitamin D are related to its ability to regulate inflammatory cytokine production by HGFs following AGE-RAGE interaction.

Injection Site Reactions to Biologic Agents Used in Psoriasis and Psoriatic Arthritis.

Psoriasis is a chronic inflammatory cutaneous disease that affects 2-3% of the general population. Up to 30% of patients with psoriasis also develop psoriatic arthritis, a chronic inflammatory and progressive arthritis. Although their precise pathogeneses remain unclear, psoriasis and psoriatic arthritis involve altered expression of proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-12, IL-17, IL-22, and IL-23. The development of biologic agents that target these cytokines has greatly improved the treatment of psoriatic disease. Injection site reactions have been reported with many of these therapies. In this paper, we will present cases and review the literature on injection site reactions with the major biologic agents administered subcutaneously for the treatment of psoriasis and psoriatic arthritis.

J Drugs Dermatol. 2017;16(7):695-698.

Interleukin 17A evoked mucosal damage is attenuated by cannabidiol and anandamide in a human colonic explant model.

Interleukin 17A (IL-17A) is a cytokine linked to inflammatory bowel disease. We investigated IL-17A expression in human colonic mucosa, whether IL-17A can elicit colonic mucosal damage in a human explant model and modulate gastrointestinal epithelial permeability in cell culture. We also tested if select cannabinoid ligands, shown to be protective in colitis models could attenuate damage caused by IL-17A. In addition, the ability of pro-inflammatory cytokines TNF-α and IL-1ß to modulate levels of IL-17A in the explant colitis model was also explored. IL-17A incubation caused significant mucosal epithelial and crypt damage which were attenuated following hydrocortisone treatment, and also reduced following anandamide or cannabidiol incubation. IL-17A-evoked mucosal damage was also associated with an increase in matrix metalloprotease activity. However, IL-17A did not induce any significant changes in epithelial permeability in confluent Caco-2 cell monolayers over a 48h incubation period. IL-17A was located predominantly in human mucosal epithelium together with IL-17C, but both IL-17A and IL-17C were also expressed in the lamina propria and submucosa. Incubation of human colonic mucosal tissue or Caco-2 cells with pro-inflammatory cytokines TNF-α and IL-1ß however did not alter IL-17A expression. These results indicate IL-17A has a widespread distribution in the human colon and the capacity to elicit mucosal damage which can be attenuated by cannabinoid ligands.