Inhibition of Bruton's tyrosine kinase and IL-2 inducible T-cell kinase suppresses both neutrophilic and eosinophilic airway inflammation in a cockroach allergen extract-induced mixed granulocytic mouse model of asthma using preventative and therapeutic strategy.

Asthma is a complex airways disease with a wide spectrum which ranges from eosinophilic (Th2 driven) to mixed granulocytic (Th2/Th17 driven) phenotypes. Mixed granulocytic asthma is a cause of concern as corticosteroids often fail to control this phenotype. Different kinases such as Brutons's tyrosine kinase (BTK) and IL-2 inducible T cell kinase (ITK) play a pivotal role in shaping allergic airway inflammation. Ibrutinib is primarily a BTK inhibitor, however it is reported to be an ITK inhibitor as well. In this study, we sought to determine the effect of Ibrutinib on Th1, Th17 and Th2 immune responses in a cockroach allergen extract (CE)-induced mixed granulocytic (eosinophilic and neutrophilic) mouse model in preventative mode. Ibrutinib attenuated neutrophilic inflammation at a much lower doses (25-75 µg/mouse) in CE-induced mixed granulocytic asthma whereas Th2/Th17 immune responses remained unaffected at these doses. However, at a much higher dose, i.e. 250 µg/mouse, Ibrutinib remarkably suppressed both Th17/Th2 and lymphocytic/neutrophilic/eosinophilic airway inflammation. At molecular level, Ibrutinib suppressed phosphorylation of BTK in neutrophils at lower doses and ITK in CD4 + T cells at higher doses in CE-treated mice. Further, effects of Ibrutinib were compared with dexamethasone on CE-induced mixed granulocytic asthma in therapeutic mode. Ibrutinib was able to control granulocytic inflammation along with Th2/Th17 immune response in therapeutic mode whereas dexamethasone limited only Th2/eosinophilic inflammation. Thus, Ibrutinib has the potential to suppress both Th17/Th2 and neutrophilic/eosinophilic inflammation during mixed granulocytic asthma and therefore may be pursued as alternative therapeutic option in difficult-to-treat asthma which is resistant to corticosteroids.

Rutin inhibits carfilzomib-induced oxidative stress and inflammation via the NOS-mediated NF-κB signaling pathway.

BACKGROUND: Carfilzomib (CFZ), a proteasome inhibitor approved by the FDA to treat multiple myeloma, may cause nephrotoxicity. HYPOTHESIS: Rutin is a bioflavonoid with antioxidant properties. We aimed to examine whether rutin protects the kidney from CFZ-induced nephrotoxicity. STUDY DESIGN: This study aimed to demonstrate the effect of rutin on CFZ-induced renal injury via the inhibition of oxidative stress and inflammation. METHODS: Wistar albino rats were divided into six groups (n = 6): Group 1 (normal control; NC) was administered normal saline for 3 weeks; Group 2 (CFZ/toxic group) received CFZ [4 mg/kg, intraperitoneal (i.p.) injection] twice weekly for 3 weeks; Group 3 (standard treatment group) was administered CFZ (4 mg/kg, i.p.) and olmesartan (2 mg/kg, p.o.) for 3 weeks; Group 4 was administered CFZ (4 mg/kg, i.p.) and rutin (10 mg/kg, p.o.) for 3 weeks; Group 5 was administered CFZ (4 mg/kg, i.p.) and rutin (20 mg/kg, p.o.) for 3 weeks; and Group 6 was administered CFZ (4 mg/kg, i.p.) and rutin (40 mg/kg, p.o.) for 3 weeks. We carried out haematological and biochemical analyses, determined oxidative stress, caspase-3 activity, and protein levels, and performed a histopathological evaluation to confirm CFZ-induced nephrotoxicity and its prevention by rutin administration. RESULTS: Exposure to only CFZ significantly (p < 0.05) increased white blood cell (WBC) count, Hb%, and HTC% concentration; however, these features were significantly decreased (p < 0.05) when olmesartan and rutin were administered. CFZ administration significantly decreased (p < 0.0001) the level of antioxidant enzymes; whereas, administration of olmesartan and rutin significantly reversed (p < 0.05) their levels toward the normal range. The levels of caspase-3 enzyme significantly increased (p < 0.001) in the CFZ group and were reduced toward the normal values by olmesartan and rutin administration. Furthermore, the results of NOS-2, NF-κB, IkBa, and IL-17 protein estimation and the histopathological evaluation strengthened our findings that rutin exhibits a protective effect against CFZ-induced nephrotoxicity. CONCLUSION: These findings clearly demonstrate that rutin ameliorates CFZ-induced oxidative stress and inflammation in nephrotoxicity via the NOS-mediated NF-κB signaling pathway.

Dexamethasone Attenuates LPS-induced Acute Lung Injury through Inhibition of NF-κB, COX-2, and Pro-inflammatory Mediators.

Dexamethasone (DEX) is a synthetic glucocorticoid with potent anti-inflammatory effects that is widely used to treat inflammatory diseases. The aim of the present study was to investigate the possible protective effect of DEX on the lipopolysaccharides (LPS)-induced acute lung injury (ALI) in a mouse model. Animals were pretreated with DEX (5 and 10 mg/kg, i.p.) for seven days and acute lung injury was induced by intranasal (i.n.) administration of LPS on day 7. In the present study, administration of LPS resulted in significant increase in neutrophils and lymphocytes count whereas a substantial reduction in T cell subsets (CD3(+) and CD4(+)) and pro-inflammatory (IL-6 and TNF-α) cytokines occurred, which were reversed by DEX treatment. RT-PCR analysis revealed an increased mRNA expression of IL-6, TNF-α, COX-2, iNOS, and NF-κB p65 and decreased IL-10 in the LPS group, which were reversed by treatment with DEX in lung tissues. Western blot analysis revealed an increased expression of COX-2, iNOS and NF-κB p65 in the LPS-group, which was reduced by treatment with DEX. Compared with the LPS group, the DEX treatment also demonstrated a considerable increase in the protein expression level of IL-10 cytokine. Administration of LPS resulted in marked increase in malondialdehyde (MDA) levels and myeloperoxidase (MPO) activity whereas noticeable decrease in glutathione (GSH) content. These changes were significantly reversed by treatment with DEX. The histological examinations revealed protective effect of DEX while LPS group aggravated lung injury. The present findings demonstrate the potent anti-inflammatory action of the DEX against acute lung injury induced by LPS.

Alleviation of Aflatoxin B1-Induced Genomic Damage by Proanthocyanidins via Modulation of DNA Repair.

In order to study the mechanisms underlying the alleviation of aflatoxin B1-induced genomic damage by proanthocyanidins (PAs), we examined the modulation of oxidative DNA damage induced by aflatoxin B1 in PAs-pretreated animals. The effects of PAs on changes in the expression of DNA damage and repair genes induced by aflatoxin B1 were also evaluated in rat marrow cells. Administration of PAs before aflatoxin B1 significantly mitigated aflatoxin B1-induced oxidative DNA damage in a dose-dependent manner. Aflatoxin B1 treatment induced significant alterations in the expression of specific DNA repair genes, and the pre-treatment of rats with PAs ameliorated the altered expression of these genes. Conclusively, PAs protect against aflatoxin B1-induced oxidative DNA damage in rats. These protective effects are attributed to the antioxidant effects of PA and enhanced DNA repair through modulation of DNA repair gene expression. Therefore, PAs are a promising chemoprotective agent for averting genotoxic risks associated with aflatoxin B1 exposure.

Diosmin downregulates the expression of T cell receptors, pro-inflammatory cytokines and NF-κB activation against LPS-induced acute lung injury in mice.

Diosmin, a natural flavonoid glycoside present abundantly in the pericarp of various citrus fruits. Because of its anti-inflammatory and antioxidant properties, it can be used in many diseases. In this study, we investigated the possible protective mechanisms of the diosmin on LPS-induced lung injury through inhibition of T cell receptors, pro-inflammatory cytokines and NF-κB activation. Animals were pretreated with diosmin (50 and 100mg/kg, p.o.) for seven days prior to lipopolysaccharides (LPS) treatment. LPS administration increased neutrophils, monocytes, lymphocytes, total leukocyte count (TLC) and platelets which were decreased by diosmin. We observed that mice exposed to LPS showed increased malondialdehyde level and MPO activity whereas marked decrease in glutathione content. These changes were significantly reversed by treatment with diosmin in a dose dependent manner. Diosmin treatment showed a substantial reduction in T cell (CD4(+) and CD8(+)) receptors and pro-inflammatory (IL-2(+) and IL-17(+)) cytokines in whole blood. In addition, RT-PCR analysis revealed increased mRNA expression of IL-6, IL-17, TNF-α, and NF-κB in the LPS group, while reduced by treatment with diosmin. Western blot analysis confirmed the increased protein expression of IL-1ß, TNF-α and NF-κB p65 in the LPS group and treatment of animals with diosmin reversed these effects. The levels of cytoplasmic p-IκB-α and p-NF-κB p65 expression also were mitigated by diosmin. The histological examinations revealed protective effect of diosmin while LPS group aggravated lung injury. These results support the potential for diosmin to be investigated as a potential agent for the treatment of lung injury and inflammatory diseases.

Riboflavin attenuates lipopolysaccharide-induced lung injury in rats.

Riboflavin (vitamin B2) is an easily absorbed micronutrient with a key role in maintaining health in humans and animals. It is the central component of the cofactors flavin adenine dinucleotide (FAD) and flavin mononucleotide (FMN) and is therefore required by all flavoproteins. Riboflavin also works as an antioxidant by scavenging free radicals. The present study was designed to evaluate the effects of riboflavin against acute lungs injury induced by the administration of a single intranasal dose (20 µg/rat) of lipopolysaccharides (LPS) in experimental rats. Administration of LPS resulted in marked increase in malondialdehyde (MDA) level (p < 0.01) and MPO activity (p < 0.001), whereas marked decrease in glutathione (GSH) content (p < 0.001), glutathione reductase (GR) (p < 0.001) and glutathione peroxidase (p < 0.01) activity. These changes were significantly (p < 0.001) improved by treatment with riboflavin in a dose-dependent manner (30 and 100 mg/kg, respectively). Riboflavin (100 mg/kg, p.o.) showed similar protective effects as dexamethasone (1 mg/kg, p.o.). Administration of LPS showed marked cellular changes including interstitial edema, hemorrhage, infiltration of PMNs, etc., which were reversed by riboflavin administration. Histopathological examinations showed normal morphological structures of lungs tissue in the control group. These biochemical and histopathological examination were appended with iNOS and CAT gene expression. The iNOS mRNA expression was increased significantly (p < 0.001) and levels of CAT mRNA expression was decreased significantly (p < 0.001) in the animals exposed to LPS, while treatment with riboflavin significantly (p < 0.01) improved expression of both gene. In conclusion, the present study clearly demonstrated that riboflavin caused a protective effect against LPS-induced ALI. These results suggest that riboflavin may be used to protect against toxic effect of LPS in lungs.

Protection against tacrolimus-induced cardiotoxicity in rats by olmesartan and aliskiren.

CONTEXT: Tacrolimus (TAC), a calcineurin inhibitor, is commonly used as an immunosuppressive agent in organ transplantation, but its clinical use may be limited due to cardiotoxicity. Olmesartan (OLM; angiotensin receptor blocker) and aliskiren (ALK; renin inhibitor) may attenuate cardiotoxicity induced by TAC by inhibition of renin-angiotensin aldosterone system. OBJECTIVE: The aim of this study was to evaluate the effect of OLM and ALK on TAC-induced cardiotoxicity. MATERIALS AND METHODS: Male Wistar albino rats weighing 200-250 g (10-12 weeks old) were used in this study. Animals were divided into four groups. Group 1 received normal saline, group 2 received TAC (2 mg/kg, intraperitoneally for 14 d), group 3 received OLM (2 mg/kg, p.o. for 28 d) + TAC and group 4 received ALK (50 mg/kg, p.o. for 28 d) + TAC. TAC-induced cardiotoxicity was assessed biochemically and histopathologically. RESULTS: Treatment with OLM or ALK decreased the TAC-induced changes in biochemical markers of cardiotoxicity such as serum aspartate transaminase, creatine kinase and lactate dehydrogenase. OLM or ALK also attenuated the effects of TAC on oxidant-antioxidant parameters such as malondialdehyde, reduced glutathione and catalase. Histopathological and ultrastructural studies showed that OLM or ALK also attenuated TAC-induced cardiotoxicity. DISCUSSION AND CONCLUSION: These results suggest that OLM as well as ALK has protective effects against TAC-induced cardiotoxicity; implying that angiotensin receptor blocker or renin inhibitor, respectively, may counteract cardiotoxicity associated with immunosuppressant use.

Home versus Clinic Blood Pressure Monitoring: Evaluating Applicability in Hypertension Management via Telemedicine.

Hypertension is a significant public health concern in Saudi Arabia, affecting 28.6% of the population. Despite the availability of effective treatments, optimal blood pressure control is not always achieved, highlighting the need for effective management strategies. This study aimed to evaluate the applicability of home, compared to clinic, blood pressure measurements for managing hypertension in the Qassim region of Saudi Arabia. The study included 85 adults undergoing antihypertensive treatment. Home blood pressure measurements were obtained during the day and the evening using automated oscillometric sphygmomanometers, whereas clinic measurements were taken during clinic hours. Home blood pressure readings were significantly lower than clinic blood pressure readings, with mean differences of 20.4 mmHg and 4.1 mmHg for systolic and diastolic blood pressures, respectively. There was a positive correlation between the clinic systolic and diastolic blood pressures (r = 0.549, p < 0.001) and a weak correlation between the daytime home and clinic systolic blood pressures (r = 0.218, p < 0.05). This study provides insight into the applicability of home blood pressure monitoring, which may aid in the development of more effective hypertension management strategies, particularly the use of morning home blood pressure monitoring to aid treatment decisions through telehealth medicine.

Blockade of interleukin-2-inducible T-cell kinase signaling attenuates acute lung injury in mice through adjustment of pulmonary Th17/Treg immune responses and reduction of oxidative stress.

Acute lung injury (ALI) is linked with considerable morbidity and mortality. ALI can be caused by various agents, one of them being sepsis. ALI is characterized by injury to vascular endothelium and alveolar epithelium that results in edema, pulmonary immune cells infiltration and hypoxemia. Neutrophils and T cells particularly play a huge role in amplification of pulmonary inflammation through release of multiple inflammatory mediators. Recent reports suggest a strong involvement of Th17 cells and oxidative stress in initiation/amplification of pulmonary inflammation during ALI. Interleukin-2-inducible T-cell kinase (ITK) plays a key role in Th17 cell development through control of several transcription factors. Therefore, our study explored the role of ITK on airway inflammation (total/neutrophilic cell counts, myeloperoxidase activity, E-cadherin expression, histopathological analyses) and effect of its inhibition on various inflammatory/anti-inflammatory pathways during ALI [phosphorylated-ITK (p-ITK), NFATc1, IL-17A, STAT3, Foxp3, IL-10, iNOS, nitrotyrosine, lipid peroxides). ALI was associated with increased total/neutrophilic cell counts and myeloperoxidase activity, and decreased E-cadherin expression in airway epithelial cells (AECs) which was concurrent with upregulation of p-ITK, NFATc1, IL-17A, STAT3 in CD4+ T cells and iNOS/nitrotyrosine in AECs. Treatment with ITK inhibitor reversed ALI-induced changes in airway inflammation and Th17 cells/oxidative stress. Treatment with ITK inhibitor further expanded Treg cells in mice with ALI. In short, our study proposes that ITK signaling plays a significant role in sepsis-induced ALI through upregulation of Th17 cells and oxidative stress. Further, findings provide evidence that ITK blockade could be a potential treatment strategy to attenuate airway inflammation associated with ALI.

Bruton's tyrosine kinase inhibitor suppresses imiquimod-induced psoriasis-like inflammation in mice through regulation of IL-23/IL-17A in innate immune cells.

Psoriasis is an unchecked chronic inflammation characterized by thick, erythematous, and scaly plaques on the skin. The role of innate immune cells in the pathogenesis of psoriasis is well documented. Bruton's tyrosine kinase (BTK) has been reported to execute important signaling functions in innate immune cells such as dendritic cells (DCs) and gamma delta T cells. However, whether inhibition of BTK would lead to modulation of innate immune function in the context of psoriatic inflammation remains largely unexplored. In the present study, we investigated the effect of selective BTK inhibitor, PCI-32765 on inflammatory signaling in CD11c + DCs and gamma delta T cells in imiquimod (IMQ)-induced mouse model of psoriasis-like inflammation. Our results show that IMQ treatment led to induction of p-BTK expression along with concomitant increase in inflammatory cytokines (IL-23, TNF-α) in CD11c + DCs in the skin. Preventive treatment with BTK inhibitor led to significant reversal in IMQ-induced inflammatory changes in CD11c + DCs of skin. Further, there was a significant decrease in dermal IL-17A levels and IL-17A + Î³Î´ + T cells after treatment with BTK inhibitor. Furthermore, short treatment of back skin with IMQ led to upregulated expression of p-BTK along with inflammatory cytokines in CD11c + DCs (IL-23, TNF-α) and IL-17A in γδ + T cells which were reversed by BTK inhibitor. Overall, our study proposes that BTK signaling serves a crucial signaling function in innate immune cells in the context of psoriatic inflammation in mice. Therefore, BTK might be a promising therapeutic target to treat psoriatic inflammation.

Therapeutic treatment with Ibrutinib attenuates imiquimod-induced psoriasis-like inflammation in mice through downregulation of oxidative and inflammatory mediators in neutrophils and dendritic cells.

Psoriasis is clinically characterized by well-demarcated silvery plaques which may appear on the extremities, scalp, and sacral area. The multidimensional interactions among innate immune cells [neutrophils and dendritic cells (DCs)], adaptive immune cells and skin resident cells result in characteristic features of psoriatic inflammation such as acanthosis, hyperkeratosis, and parakeratosis. Tec family kinases are involved in the pathogenesis of several inflammatory diseases. One of them is Bruton's tyrosine kinase (BTK) which is reported to carry out inflammatory and oxidative signaling in neutrophils and DCs. Effect of BTK inhibitor with regard to psoriatic inflammation has not been explored previously especially in a therapeutic setting. In the current investigation, effect of BTK inhibitor, Ibrutinib on oxidative/inflammatory signaling in dermal/splenic neutrophils [phosphorylated BTK (p-BTK), inducible nitric oxide synthase (iNOS), nitrotyrosine], CD11c + DCs (p-BTK, iNOS, nitrotyrosine, MCP-1, TNF-α) and enzymatic antioxidants [superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GR)] in imiquimod (IMQ)-induced psoriatic inflammation was evaluated using therapeutic mode. Our results show that IMQ treatment led to induction of p-BTK expression along with concomitant increase in oxidative stress in neutrophils, and CD11c + DCs in skin/periphery. Therapeutic treatment with Ibrutinib caused attenuation of IMQ-induced oxidative stress in CD11c + DCs and neutrophils. Further there were dysregulations in antioxidants enzymes (SOD/GPx/GR) in the skin of IMQ-treated mice, which were corrected by Ibrutinib. In short, our study reveals that BTK signaling in neutrophils and CD11c + DCs upregulates oxidative stress which is concomitant with psoriatic inflammation in mice. Ibrutinib attenuates psoriasis inflammation through downregulation of oxidative stress in these innate immune cells.

Inhibition of spleen tyrosine kinase signaling protects against acute lung injury through blockade of NADPH oxidase and IL-17A in neutrophils and γδ T cells respectively in mice.

Acute lung injury (ALI) is one of the most serious complications in critically ill patients which often leads to morbidity and mortality. ALI characterized by severe inflammation of lungs occurs due to uncontrolled inflammatory immune response. However, the immunological mechanism(s) are far from being understood. The spleen tyrosine kinase (SYK), a key component of immune receptor signaling, plays a critical role in the modulation of inflammatory signaling in different immune cells. However, its role in ALI remains to be explored. Therefore, in this study, we investigated the effect of R406, a SYK inhibitor in lipopolysaccharide (LPS)-induced ALI mouse model. LPS led to increased SYK expression in neutrophils and gamma delta (γδ) T cells. This was associated with increased neutrophilic airway inflammation, vascular permeability, myeloperoxidase activity in the lung with upregulated expression of NADPH oxidase (NOX2)/MCP-1/TNF-α in neutrophils and IL-17A in γδ T cells/lung. Pulmonary inflammation was associated with higher mortality in mice with ALI. Inhibition of SYK signaling using R406 in the lung led to blockade of neutrophilic airway inflammation, vascular permeability, pro-inflammatory cytokine release and oxidative stress in innate immune cells, i.e. γδ T cells and neutrophils and the lung. R406 administered LPS group had better survival rate than LPS group. This suggests that SYK upregulation in γδ T cells and neutrophils plays an important role in inflammatory process during ALI. In conclusion, R406 exhibited a great potential to block the LPS-induced airway inflammation and mortality which could be developed as a potential future therapy in ALI.

Sulforaphane treatment reverses corticosteroid resistance in a mixed granulocytic mouse model of asthma by upregulation of antioxidants and attenuation of Th17 immune responses in the airways.

Sulforaphane has received considerable attention in recent years due to its antioxidant and anti-inflammatory properties. Its preventive effect in the inhibition of airway inflammation is known; however, whether it affects mixed granulocyte asthma (corticosteroid resistance phenotype) is largely undiscovered. Therefore, we assessed the effect of pharmacological activation of Nrf2, a redox-sensitive transcription factor, using sulforaphane in a mouse model of mixed granulocyte airway inflammation. Mice were sensitized and challenged with cockroach allergen extract (CE), and airway inflammatory parameters and markers of steroid resistance [Nrf2 activity, oxidant-antioxidant balance in airway epithelial cells (AECs)/lung, and IL-17A-related pathway in Th17 cells and dendritic cells (DCs)] were investigated. Our results show that sulforaphane administration reduced neutrophilic airway inflammation, myeloperoxidase (MPO) activity, and Th17 immune responses in a mixed granulocyte mouse model of asthma through Nrf2 activation. On the other hand, corticosteroid treatment decreased Th2/eosinophilic immune responses but had little on Th17/neutrophilic immune responses. However, combined treatment with both almost completely blocked both neutrophilic/eosinophilic and Th17/Th2 immune responses in the lung. Sulforaphane treatment led to induction of antioxidant enzymes (SOD, GPx) in AECs and pulmonary non-enzymatic antioxidants. Further, it led to reduction in inflammatory cytokines (IL-6/IL-23/IL-17A) in Th17 cells/CD11c + DCs during mixed granulocytic inflammation. Collectively, our study presents the evidence that activation of Nrf2 by sulforaphane reduces neutrophilic airway inflammation by upregulation of antioxidants and downregulation of inflammatory cytokines in airways. This is possibly the basis for reversal of corticosteroid resistance in this model. This shows the therapeutic potential of sulforaphane in mixed granulocyte asthma.

Apremilast ameliorates carfilzomib-induced pulmonary inflammation and vascular injuries.

Acute lung injury (ALI) due to chemotherapy occurs frequently. It presents a challenge for clinicians managing therapies for different types of cancers. Carfilzomib (Kyprolis™) is a new proteasome inhibitor that shows promise for the treatment of relapsing multiple myeloma. However, several cases of severe ALI have raised concern about the use of carfilzomib against relapsed multiple myelomas. To improve the efficacy of carfilzomib, a new anti-inflammatory drug for psoriasis treatment, apremilast (Otezla™) was investigated for its protective effects against carfilzomib-induced ALI in rats. RT-PCR analyses revealed that carfilzomib administration in rats markedly increased the levels of tumor necrosis factor-alpha and nuclear factor-kappa B and myeloperoxidase activity with a concomitant increase in lipid peroxidation. The anti-inflammatory cytokine, interleukin-10, was downregulated following carfilzomib administration. Reduction in glutathione levels indicated diminished cellular antioxidant defenses in response to carfilzomib-induced ALI. ALI was confirmed by histopathological observations in lung tissue slices. Apremilast administration reduced lung inflammation in terms of reduction in myeloperoxidase activity and levels of tumor necrosis factor-alpha and alveolar infiltrating cells. Apremilast reversed all observed toxic effects of carfilzomib and prevented ALI in rats.

Inhibition of spleen tyrosine kinase attenuates psoriasis-like inflammation in mice through blockade of dendritic cell-Th17 inflammation axis.

Psoriasis is a debilitating autoimmune disease of the skin characterized by acanthosis and hyperkeratosis resulting from excessive growth of keratinocytes in the epidermis and inflammatory infiltrates in the dermis. Innate immune cells such as dendritic cells (DCs), perform a critical role in the pathophysiology of psoriasis by presenting inflammatory/costimulatory signals for differentiation of Th17 cells. Recent studies point to the involvement of spleen tyrosine kinase (SYK) in inflammatory signaling cascade of DCs. However, it is yet to be determined whether SYK inhibition in DCs would lead to diminishment of psoriatic inflammation. Therefore, our study evaluated the effects of SYK inhibitor, R406 on imiquimod (IMQ)-induced psoriasis-like inflammation, expression of costimulatory/inflammatory molecules in DCs and their relationship with Th17/Treg cells. Our data show that R406 causes attenuation of IMQ-induced dermal inflammation as shown by reduction in ear/back skin thickness, acanthosis and myeloperoxidase activity. This was concurrent with reduction in inflammatory cytokines and co-stimulatory molecules in CD11c + DCs such as IL-6, IL-23, MHCII, and CD40. This favoured the suppression of Th17 cells and upregulation of Treg cells in R406-treated mice with psoriasis-like inflammation. Direct activation of TLR7 by IMQ in splenocytic cultures led to increased SYK expression in CD11c + DCs and release of IL-23/IL-6. IMQ-induced IL-6/IL-23 levels were significantly diminished by SYK inhibitor, R406 in splenocytic cultures. In essence, our study shows that SYK inhibition supresses psoriasis-like inflammation by modifying DC function in mice. Further, it implies that SYK inhibition could be a prospective therapeutic approach for the treatment of psoriasis-like inflammation.

IL-17A-induced neutrophilic airway inflammation is mediated by oxidant-antioxidant imbalance and inflammatory cytokines in mice.

IL-17 A is produced by several innate and adaptive immune cells which include Th17, and innate lymphoid 3 cells in the lung. IL-17 A can activate airway epithelial cells (AECs), through IL-17 receptor (IL-17R) leading to production of chemokines/cytokines. Inflammatory nature of IL-17 A and its signaling has been assessed by several studies using IL-17 A/IL-17R knockout mice which show attenuated inflammation in different disease models. IL-17 A/IL-17R signaling also plays an important role in pulmonary inflammation through recruitment of neutrophils. However, effect of IL-17 A on oxidant-antioxidant balance in the lung and its association with pulmonary inflammation has not been evaluated earlier. Our study evaluated the effect of intranasal administration of IL-17 A on oxidant-antioxidant balance [inducible nitric oxide synthase (iNOS), nitrotyrosine, lipid peroxides, glutathione peroxidase, and total glutathione levels] and chemokines/cytokines expression (IL-6, MCP-1, and MIP-2) in the lung/AECs and their modulation by an antioxidant, N-acetyl cysteine (NAC). Our study shows that IL-17 A administration leads to increased neutrophilic inflammation along with concomitant increase in iNOS and nitrotyrosine/lipid peroxides. On the other hand, there was a reduction in GPx activity and total thiol levels after IL-17 A administration. IL-17 A administration also led to increased IL-6/MCP-1/MIP-2. IL-17A-induced oxidative stress/IL-6 expression and neutrophilic inflammation was attenuated by NAC treatment, whereas there was no effect on chemokines. This suggests that antioxidant NAC attenuates IL-17A-induced pulmonary inflammation by restoring oxidant-antioxidant balance and attenuation of IL-6 in the lung. Further, our study suggests that inflammatory pulmonary disorders which involve increase in IL-17 A may be ameliorated by NAC treatment.

GPR43 activation enhances psoriasis-like inflammation through epidermal upregulation of IL-6 and dual oxidase 2 signaling in a murine model.

The gut is densely inhabited by commensal bacteria, which metabolize dietary fibers/undigested carbohydrates and produce short-chain fatty acids such as acetate. GPR43 is one of the receptors to sense short-chain fatty acids, and expressed in various immune and non-immune cells. Acetate/GPR43 signaling has been shown to affect various inflammatory diseases through Th17 responses and NADPH oxidase (NOX)-derived reactive oxygen species (ROS) generation. However, no study has previously explored the effects of GPR43 activation during psoriasis-like inflammation. Therefore, this study investigated the effect of acetate/phenylacetamide (GPR43 agonists) on imiquimod induced skin inflammation in mice. Mice were administered phenylacetamide/acetate followed by assessment of skin inflammation, NOXs (NOX-2, NOX-4, dual oxidases), and Th17 related signaling. Our study showed induction of epidermal GPR43 after imiquimod treatment, i.e. psoriasis-like inflammation. Acetate administration in psoriatic mice led to further increase in skin inflammation (ear thickness/myeloperoxidase activity) with concurrent increase in Th17 immune responses and epidermal dual oxidase-2 signaling. Further, topical application of GPR43 agonist, phenylacetamide led to enhanced ear thickness with concomitant epidermal IL-6 signaling as well as dual oxidase-2 upregulation which may be responsible for increased psoriasis-like inflammation. Taken together, dual oxidase-2 and IL-6 play important roles in GPR43-mediated skin inflammation. The current study suggests that GPR43 activation in psoriatic patients may lead to aggravation of psoriatic inflammation.

Psoriasis-like inflammation leads to renal dysfunction via upregulation of NADPH oxidases and inducible nitric oxide synthase.

Psoriatic patients have systemic inflammation as well as oxidative stress, which are associated with cardiovascular disorders such as atherosclerosis, hypertension myocardial infarction, and stroke. Psoriasis has also been shown to be associated with kidney disease in several studies. Both disorders also have strong component of oxidative stress which usually emanates from NADPH oxidases (NOXs) and inducible nitric oxide synthase (iNOS). However, whether psoriatic inflammation leads to renal oxidative stress and dysfunction remains unexplored. Therefore, this study investigated the effect of imiquimod (IMQ)-induced psoriatic inflammation on kidney function and inflammation in a murine model. Mice were topically applied IMQ followed by various analyses in kidney/blood related to inflammation and kidney function. Psoriatic inflammation in mice was associated with kidney dysfunction as reflected by increased serum creatinine and blood urea nitrogen. Kidney dysfunction was paralleled by upregulation of ROS generating enzymes such as NOX2, NOX4 and iNOS with concomitant oxidative stress. Treatment either with general antioxidant, N-acetyl cysteine or NOX/iNOS inhibitors led to improvement of IMQ-induced renal dysfunction and oxidative stress. On the contrary, buthionine sulfoximine, oxidant inducer further aggravated IMQ-induced renal impairment and oxidant-antioxidant imbalance. Our data suggest that psoriatic inflammation causes kidney dysfunction where NOXs and iNOS play important roles. Treatment with antioxidants may be considered as adjunct therapy in psoriatic patients with kidney disease.

Psoriatic inflammation causes hepatic inflammation with concomitant dysregulation in hepatic metabolism via IL-17A/IL-17 receptor signaling in a murine model.

Psoriatic inflammation has been shown to be associated with cardiovascular dysfunction and systemic inflammation. Recently, psoriasis has also been linked to hepatic disorders, however underlying mechanism connecting the two are unknown. IL-17A being a central pro-inflammatory cytokine in the pathogenesis of psoriasis may be involved in hepatic inflammation through its receptor and downward signaling; however so far no study has investigated IL-17A related signaling in the liver during psoriasis in a murine model. Therefore, this study explored psoriasis-induced hepatic inflammation and concurrent metabolic changes. Mice were applied topically imiquimod (IMQ) to develop psoriatic inflammation. Additionally mice were also treated either with IL-17A or anti-IL17A antibody to explore the role of IL-17 related signaling in liver. Mice were then assessed for hepatic inflammation through assessment of inflammatory/oxidative stress markers (IL-17RC, NFκB, IL-6, MCP-1, IL-1ß, GM-CSF, ICAM-1, iNOS, lipid peroxides and myeloperoxidase activity) as well as hepatic injury (alanine aminotransferase, aspartate aminotransferase and alkaline phosphatase) and protein/lipid metabolic biomarkers (total proteins, albumin, total bilirubin, triglycerides, HDL cholesterol, and total cholesterol). IMQ treatment led to hepatic inflammation as evidenced by increased pro-inflammatory cytokines and oxidative stress with concomitant dysregulation in hepatic protein/lipid metabolism. Treatment with IL-17A further aggravated, whereas treatment with anti-IL17A antibody ameliorated IMQ-induced changes in hepatic injury/inflammation and protein/lipid metabolism. Our study shows for the first time that psoriatic inflammation leads to hepatic inflammation which results in dysregulated protein/lipid metabolism through IL-17RC/NFκB signaling. This could result in increased risk of cardiovascular dysfunction in patients with psoriasis.

Psoriatic inflammation enhances allergic airway inflammation through IL-23/STAT3 signaling in a murine model.

Psoriasis is an autoimmune inflammatory skin disease characterized by activated IL-23/STAT3/Th17 axis. Recently psoriatic inflammation has been shown to be associated with asthma. However, no study has previously explored how psoriatic inflammation affects airway inflammation. Therefore, this study investigated the effect of imiquimod (IMQ)-induced psoriatic inflammation on cockroach extract (CE)-induced airway inflammation in murine models. Mice were subjected to topical and intranasal administration of IMQ and CE to develop psoriatic and airway inflammation respectively. Various analyses in lung/spleen related to inflammation, Th17/Th2/Th1 cell immune responses, and their signature cytokines/transcription factors were carried out. Psoriatic inflammation in allergic mice was associated with increased airway inflammation with concurrent increase in Th2/Th17 cells/signature cytokines/transcription factors. Splenic CD4+ T and CD11c+ dendritic cells in psoriatic mice had increased STAT3/RORC and IL-23 mRNA expression respectively. This led us to explore the effect of systemic IL-23/STAT3 signaling on airway inflammation. Topical application of STA-21, a small molecule STAT3 inhibitor significantly reduced airway inflammation in allergic mice having psoriatic inflammation. On the other hand, adoptive transfer of IL-23-treated splenic CD4+ T cells from allergic mice into naive recipient mice produced mixed neutrophilic/eosinophilic airway inflammation similar to allergic mice with psoriatic inflammation. Our data suggest that systemic IL-23/STAT3 axis is responsible for enhanced airway inflammation during psoriasis. The current study also suggests that only anti-asthma therapy may not be sufficient to alleviate airway inflammatory burden in asthmatics with psoriasis.