Structure-Activity Relationship Analysis of Fluoxetine for Suppression of Inflammatory Cytokine Production.

There is accumulating evidence that selective serotonin reuptake inhibitors (SSRIs), clinically used as antidepressants, have a beneficial effect on inflammatory diseases such as coronavirus disease 2019 (COVID-19). We previously compared the inhibitory effects of five U.S. Food and Drug Administration (FDA)-approved SSRIs on the production of an inflammatory cytokine, interleukin-6 (IL-6), and concluded that fluoxetine (FLX) showed the most potent anti-inflammatory activity. Here, we investigated the structure-activity relationship of FLX for anti-inflammatory activity towards J774.1 murine macrophages. FLX suppressed IL-6 production induced by the TLR3 agonist polyinosinic-polycytidylic acid (poly(I : C)) with an IC50 of 4.76 µM. A derivative of FLX containing chlorine instead of the methylamino group lacked activity, suggesting that the methylamino group is important for the anti-inflammatory activity. FLX derivatives bearing an N-propyl or N-(pyridin-3-yl)methyl group in place of the N-methyl group exhibited almost the same activity as FLX. Other derivatives showed weaker activity, and the N-phenyl and N-(4-trifluoromethyl)benzyl derivatives were inactive. The chlorine-containing derivative also lacked inhibitory activity against TLR9- or TLR4-mediated IL-6 production. These derivatives showed similar structure-activity relationships for TLR3- and TLR9-mediated inflammatory responses. However, the activities of all amino group-containing derivatives against the TLR4-mediated inflammatory response were equal to or higher than the activity of FLX. These results indicate that the substituent at the nitrogen atom in FLX strongly influences the anti-inflammatory effect.

Colorable role of interleukin (IL)-6 in obesity hypertension: A hint from a Chinese adult case-control study.

BACKGROUND: Obesity and hypertension are major risk factors for cardiovascular diseases that affect millions of people worldwide. Both conditions are associated with chronic low-grade inflammation, which is mediated by cytokines such as interleukin-6 (IL-6). IL-6 is a multifunctional cytokine that can have pro-inflammatory or anti-inflammatory effects depending on the context. The exact role of IL-6 in obesity-associated hypertension is unclear. OBJECTIVE: To investigate how IL-6 affects blood pressure, inflammation, and metabolic function in obesity-hypertension using a Chinese adult case-control study. METHODS: A total of 153 participants were sorted into four subgroups according to their body mass index (BMI) and blood pressure (BP): normal healthy group (NH), just obesity group (JO), just-hypertension group (JH), and obesity-hypertension group (OH). Serum IL-6 concentrations were measured by Enzyme-linked Immunosorbent Assay (ELISA) and their correlations with anthropometric and laboratory parameters and their differences across the subgroups were examined. Multiple linear regression analysis was performed to identify the predictors of serum IL-6 concentrations in each group. RESULTS: Serum IL-6 concentrations were higher in NH group than in JO group and correlated positively with diastolic blood pressure in NH and JO groups, but not in JH and OH groups. Serum IL-6 concentrations also correlated with albumin in NH group, alkaline phosphatase in JO group, serum creatinine and fasting blood glucose in JH group. The influencing factors of serum IL-6 concentrations varied among the four groups, with gender, diastolic blood pressure and albumin being significant predictors in NH group, alkaline phosphatase in JO group, age and serum creatinine in JH group, and none in OH group. CONCLUSIONS: These results suggest that IL-6 may play diverse effects in the pathogenesis of obesity- hypertension, depending on the presence or absence of obesity and hypertension. Further studies are needed to elucidate the underlying mechanisms of IL-6 signaling and function in these diseases.

Arid5a/IL-6/PAI-1 Signaling Is Involved in the Pathogenesis of Lipopolysaccharide-Induced Kidney Injury.

A systemic inflammatory response leads to widespread organ dysfunction, such as kidney dysfunction. Plasminogen activator inhibitor-1 (PAI-1) is involved in the pathogenesis of inflammatory kidney injury; however, the regulatory mechanism of PAI-1 in injured kidneys remains unclear. PAI-1 is induced by interleukin (IL)-6 in patients with sepsis. In addition, the stabilization of IL-6 is regulated by the adenine-thymine-rich interactive domain-containing protein 5a (Arid5a). Therefore, the aim of the present study was to examine the involvement of Arid5a/IL-6/PAI-1 signaling in lipopolysaccharide (LPS)-induced inflammatory kidney injury. LPS treatment to C57BL/6J mice upregulated Pai-1 mRNA in the kidneys. Enzyme-linked immunosorbent assay (ELISA) revealed that PAI-1 expression was induced in the culture supernatants of LPS-treated human umbilical vein endothelial cells, but not in those of LPS-treated human kidney 2 (HK-2) cells, a tubular cell line. Combined with single-cell analysis, endothelial cells were found to be responsible for PAI-1 elevation in LPS-treated kidneys. Administration of TM5441, a PAI-1 inhibitor, reduced the urinary albumin/creatinine ratio, concomitant with downregulation of Il-6 and Arid5a mRNA expressions. IL-6 treatment in LPS model mice further upregulated Pai-1 mRNA expression compared with LPS alone, accompanied by renal impairment. Furthermore, the expression of Il-6 and Pai-1 mRNA was lower in Arid5a knockout mice than in wild-type mice after LPS treatment. Taken together, the vicious cycle of Arid5a/IL-6/PAI-1 signaling is involved in LPS-induced kidney injury.

Mesenchymal Stem Cells Promote IL-6 Secretion and Suppress the Gene Expression of Proinflammatory Cytokines in Contractile C2C12 Myotubes.

Sarcopenia is not only a major cause of disability but also a risk factor for obesity and diabetes in elderly persons. Exercise is an effective method for improving the sarcopenic condition by inducing the secretion of interleukin (IL)-6, which has the capacities to both promote muscle hypertrophy and regulate lipid metabolism and glucose homeostasis, by skeletal muscle. We previously showed that mesenchymal stem cells (MSCs) promote IL-6 secretion by lipopolysaccharide-stimulated C2C12 mouse skeletal muscle myotubes via paracrine mechanisms. Therefore, in this study, we investigated the effect of paracrine actions of MSCs on IL-6 and proinflammatory cytokine expression in contractile C2C12 myotubes by applying electrical stimulation. IL-6 secretion by C2C12 myotubes was increased by electrical stimulation, and a more significant increase in IL-6 secretion was observed in electrically stimulated C2C12 myotubes cultured in conditioned medium from MSCs. The activation of nuclear factor-κB in C2C12 myotubes was also promoted by the combination of conditioned medium from MSCs and electrical stimulation. Moreover, the increases in tumor necrosis factor-α and IL-1ß mRNA expression in C2C12 myotubes induced by electrical stimulation were suppressed by culture in conditioned medium from MSCs. The present findings suggest that MSCs transplantation or injection of their extracellular vesicles improve the therapeutic effect of exercise against sarcopenia without exacerbating inflammation.

Aloe vera and Fermented Extracts Exhibit an Anti-Inflammatory Effect on Human Glioblastoma/Astrocytoma U373 MG Cells.

The anti-inflammatory effects of Aloe vera (AV), polysaccharide extract from AV, and extracts from the digestion and colonic fermentation of AV were evaluated using an immortal astrocyte cell line (U373 MG) that develops a neuro-inflammatory profile. Cell viability and inflammatory markers were assessed after stimulation with neuropeptide substance P (SP) that activates the pro-inflammatory MAPK (mitogen-activated protein kinase) pathway. Cell viability after SP treatment was over 50% at 10 mg/mL AV, polysaccharide extract from AV, extracts from the digestion: non-digestible fraction of AV non-digestible fraction of polysaccharide extract from AV and extracts from the colonic fermentation of AV, at 4 and 24 h. Moreover, cells exposed to SP and treated with these extracts showed lower protein-activated ERK1/ERK2 (extracellular signal-regulated kinases 1 and 2), p38 (MAPK protein p38), and NFκB (nuclear factor κB) levels with respect to the SP-stimulated control. Inflammation inhibition by extracts of polysaccharide extract from AV and extracts from the colonic fermentation of AV, at 24 h in the study of p38 was not as statistically significant in ERK1/ERK2 and NFκB. Nevertheless, there was a significant decrease (p < 0.05) in pro-inflammatory cytokine IL-6 levels in cells exposed to all samples. Samples with extracts from the colonic fermentation of AV, at 4 or 24 h showed the highest inhibitory effect on IL-6 production.

Rapid changes in serum IL-6 levels in preterm newborns with Gram-negative early-onset sepsis.

Early-onset sepsis (EOS) remains a leading cause of morbidity and mortality for newborns, especially in preterm birth. Serum IL-6 levels are used as an accurate marker for EOS; however, no study has focused on the changes in serum IL-6 levels in newborns with EOS. Here, we investigated 6 preterm newborns (23.4-28.2 wks' gestational age) with birthweights of 570-1080 g who were diagnosed with EOS. All newborns received active treatment, including exchange transfusions and/or polymyxin B-immobilized fiber column direct hemoperfusion for septic shock. In the 3 surviving newborns, serum-IL-6 levels peaked at >500,000, 256,500, and 356,000 pg/mL within 12 h of life, and then decreased to <100 pg/mL by 72 h of life. In the 3 newborns who died at 17, 30, and 61 h of life, serum IL-6 levels increased to >500,000, 198,000, and 1,354,000 pg/mL, respectively, prior to death. Therefore, in preterm newborns suspected of EOS, serial serum IL-6 determinations would be useful for not only detecting EOS, but also for monitoring sepsis severity.

Locally-secreted interleukin-6 is related with radiological severity in smear-negative pulmonary tuberculosis.

Pulmonary tuberculosis (PTB) has been identified as a substantial public health threat and diagnostic challenge. A large proportion of patients exhibit negative smear tests despite active infection. The role of cytokines in the pathophysiology and clinical severity of PTB remains a controversial question. We evaluated the pattern of cytokines presents locally in patients with smear-negative PTB. Levels of tumor necrosis factor (TNF)-α, interferon (IFN)-γ, interleukin (IL)-2, IL-4, IL-6, IL-10, and IL-17 in bronchoalveolar lavage fluid (BALf) from patients with smear-negative PTB, as well as in those with other pulmonary diseases and controls, were performed by flow cytometry. ROC curve and a radiological severity scale were used to establish the potential diagnosis use and the relationship of the cytokine levels with disease severity, respectively. The levels of IL-6 were higher in the PTB (P = 0.0249) and pneumonia (P = 0.0047) groups compared to controls. Low to undetectable levels of TNF-α, IFN-γ, IL-2, IL-4, IL-10, and IL-17 were found in BALf, even after sample concentration using filtration columns and centrifugation. IL-6 levels measured in BALf could distinguish PTB patients or pneumonia patients from controls (AUC: 0.91, P = 0.002 and AUC: 0.86, P = 0.001, respectively), but not patients with PTB from those with pneumonia (AUC: 0.51, P = 0.86). IL-6 levels were related with the severity of PTB, as levels were higher in patients with higher radiological severity. These results confirm the importance of IL-6 in the immunopathology of smear-negative PTB.

Mesenchymal Stem Cells Alter the Inflammatory Response of C2C12 Mouse Skeletal Muscle Cells.

Mesenchymal stem cells (MSCs) are capable of repairing skeletal muscle via paracrine mechanisms. This regenerative effect of MSCs on skeletal muscle is based on promoting the proliferation and differentiation of myogenic cells and inhibiting the inflammatory response of immune cells. However, it is unclear whether MSCs affect the inflammatory response of skeletal muscle cells. In this study, we evaluated the paracrine effect of mouse MSCs on the inflammatory response of lipopolysaccharide (LPS)-stimulated C2C12 mouse myoblasts. Interleukin (IL)-6 production from LPS-stimulated C2C12 cells was significantly increased by coculture with MSCs or culture in conditioned medium of MSCs. This increased IL-6 production from C2C12 cells was not significantly suppressed by inhibiting mitogen-activated protein kinase pathways, but it was significantly suppressed by pretreatment with nuclear factor-κB (NF-κB) and signal transducer and activator of transcription 3 (STAT3) inhibitors. In addition, IL-6 and inducible nitric oxide synthase (iNOS) mRNA expression was increased significantly in C2C12 cells cocultured with MSCs, while tumor necrosis factor (TNF)-α and IL-1ß mRNA expression was decreased. Furthermore, conditioned medium of C2C12 cells cocultured with MSCs exerted remarkable anti-inflammatory effects on LPS-stimulated mouse macrophages.

Anti-metastatic Effects of Baicalein by Targeting STAT3 Activity in Breast Cancer Cells.

Signal transducer and activator of transcription 3 (STAT3) is considered a potential target for cancer treatment because of its relationship with cellular transformation and tumor initiation and progression. In this study, we aimed to identify a new anti-cancer drug candidate from natural products by targeting STAT3 activity. Using STAT3-luciferase reporter cell line, we screened the chemical library of natural products and found that baicalein, a flavone isolated from the roots of Scutelleria baicalensis, strongly suppressed STAT3 activity in breast cancer cells. Baicalein inhibited STAT3 transcriptional activity and its phosphorylation, and further exhibited anti-proliferative effects in breast cancer cells. Moreover, baicalein suppressed the production of interleukin (IL)-6 and the metastatic potential of breast cancer cells both in vitro and in vivo. Collectively, our study suggests baicalein as an attractive phytochemical compound for reducing metastatic potential of breast cancer cells by regulating STAT3 activity.

Salivary inflammatory markers in tension type headache and migraine: the SalHead cohort study.

OBJECTIVE: To investigate the possible association between salivary CRP, IL-1ß, and IL-6 levels, depression/anxiety and migraine, and tension type headache (TTH) in saliva of these patients. METHOD: A longitudinal prospective study was conducted on 30 migraineurs, 30 TTH patients, and 30 age-matched healthy controls. Anxiety and depression were measured by using the Hamilton Anxiety Rating Scale (HAM-A), and the Beck Depression Inventory (BDI). Salivary IL-6, IL-1ß, and CRP were collected in distinct time points as A: headache-free period, B: during headache, C: 1 day after headache attack, and measured by using ELISA kits. RESULTS: No significant differences were found in time variation of CRP, IL-1ß, and IL-6 levels between migraine and TTH (p > 0.05). IL1-ß had the highest discriminative value (area under the curve = 0.924, p value < 0.001), and then CRP (area under the curve = 0.763, p value < 0.001) and IL-6 (area under the curve = 0.537, p value = 0.58). CRP and IL-6 were negatively correlated with HAM-A and BDI scores. CONCLUSION: IL1-ß had the highest discriminative value between headache patients and controls compared with CRP and IL-6. CRP and IL-6 were correlated with lower symptom scores of anxiety and depression prior or immediately after the headache period in patients groups.

Old Friends, immunoregulation, and stress resilience.

There is a considerable body of evidence indicating that chronic adverse experience, especially chronic psychosocial stress/trauma, represents a major risk factor for the development of many somatic and affective disorders, including inflammatory bowel disease (IBD) and posttraumatic stress disorder (PTSD). However, the mechanisms underlying the development of chronic stress-associated disorders are still in large part unknown, and current treatment and prevention strategies lack efficacy and reliability. A greater understanding of mechanisms involved in the development and persistence of chronic stress-induced disorders may lead to novel approaches to prevention and treatment of these disorders. In this review, we provide evidence indicating that increases in immune (re-)activity and inflammation, potentially promoted by a reduced exposure to immunoregulatory microorganisms ("Old Friends") in today's modern society, may be causal factors in mediating the vulnerability to development and persistence of stress-related pathologies. Moreover, we discuss strategies to increase immunoregulatory processes and attenuate inflammation, as for instance contact with immunoregulatory Old Friends, which appears to be a promising strategy to promote stress resilience and to prevent/treat chronic stress-related disorders.

Icaritin inhibits glioblastoma cell viability and glycolysis by blocking the IL-6/Stat3 pathway.

Glioblastoma (GBM) is a common and aggressive brain tumor that is associated with significant increase in glycolysis for energy production. Icaritin is a natural compound and exhibits anticancer activity in GBM. However, the effect of icaritin on glycolysis in GBM cells remains unclear. The aim of the current study was to investigate the effect of icaritin on glycolysis in GBM cells. The human GBM cell lines U87 and T98G were treated with icaritin or the inhibitor of Stat3 (S3I-201) in the presence or absence of recombinant human interleukin (IL)-6. Cell viability was measured using the 3-(4,5-dimethylthiazol-2-yl)-2,5 diphenyltetrazolium bromide (MTT) assay. The glycolysis was analyzed by detecting the glucose consumption and lactate production. The Western blot analysis was conducted to detect the expressions of hexokinase 2 (HK2), signal transducer and activator of transcription 3 (Stat3), p-Stat3, and B lymphoma Mo-MLV insertion region 1 (Bmi-1). Results showed that icaritin inhibited the viability of U87 and T98G cells in a dose-dependent manner. The decreased glucose consumption and lactate production, accompanied by reduced expressions of HK2, were found in both U87 and T98G cells. Icaritin inhibited the IL-6/Stat3 pathway, which is evidenced by the decreased expressions of p-Stat3 and Bmi-1. IL-6 treatment induced the phosphorylation of Stat3 and Bmi-1 expression, increased cell viability, as well as elevated glucose consumption, lactate production, and HK2 expression; however, the effects of IL-6 were attenuated by icaritin or S3I-201 treatment. In conclusion, icaritin exerted inhibitory effects on cell viability and glycolysis in GBM cells, which was mediated by the IL-6/Stat3 pathway.

TAFRO syndrome as a cause of glomerular microangiopathy: a case report and literature review.

BACKGROUND: TAFRO syndrome is a systemic inflammatory disorder that manifests as thrombocytopenia (T), anasarca (A), fever (F), reticulin fibrosis (R), and organomegaly (O). Renal dysfunction is frequently complicated with TAFRO syndrome, however, it is challenging to perform kidney biopsy in patients with TAFRO syndrome in the presence of thrombocytopenia. Renal histology in TAFRO syndrome mainly shows membranoproliferative glomerulonephritis (MPGN)-like lesions or thrombotic microangiopathy (TMA)-like glomerulopathy. We review our case and previous reports of TAFRO syndrome with kidney biopsy findings and discuss the renal pathophysiology of TAFRO syndrome. CASE PRESENTATION: We describe a previously healthy 48- year-old woman with TAFRO syndrome. Kidney biopsy performed before the treatment showed diffuse global endocapillary proliferative changes with endothelial cell swelling, double contours of partial capillary walls, and mesangiolysis, consistent with TMA-like glomerulopathy. Glucocorticoid therapy including steroid pulse was ineffective and she developed anasarca, renal dysfunction and oliguria. Hemodialysis was required. However, the anti-Interleukin (IL)-6 receptor antibody (tocilizumab) therapy was very effective. An increase in urinary volume was achieved about 2 weeks after the tocilizumab therapy and hemodialysis was discontinued. To investigate the renal pathophysiology of TAFRO syndrome, we performed immunohistological staining of vascular endothelial growth factor (VEGF)-A, CD34, and D2-40, in our case and a normal control kidney. Glomerular VEGF-A was especially positive in podocytes both, in the control and in the case, with no significant difference and there was a significant increase of VEGF-A staining area in the cortical peritubular capillaries in the case. Both glomerular and renal cortical CD34 expression were significantly decreased in our case. D2-40 expression in cortex was not significantly different. CONCLUSIONS: We reviewed our case and other 10 previous reports about renal biopsy findings in TAFRO syndrome and found that glomerular microangiopathy was a common finding. IL-6-VEGF-axis-induced glomerular microangiopathy may play a crucial role in developing acute kidney injury in TAFRO syndrome and the anti-IL-6 receptor antibody therapy may be useful for TAFRO syndrome refractory to glucocorticoids. About the pathophysiology of VEGF in TAFRO syndrome, VEGF balance in the glomerulus and perhaps in the peritubular capillary system as well may be critical. Further investigation is needed.

Repetitive negative thinking, meaning in life, and serum cytokine levels in pregnant women: varying associations by socioeconomic status.

Elevated proinflammatory cytokines and decreased antiinflammatory cytokines are important in the context of perinatal health, and immune dysregulation has been found among perinatal women with low socioeconomic status (SES). Data examining psychological factors that may contribute to cytokines in pregnancy are lacking. Of importance, these associations may be most evident among women with low SES. This study examined the moderating role of SES on associations among presence of meaning in life and repetitive negative thinking with cytokine levels among 67 pregnant women. A cumulative SES index was calculated using income, education, perceived social class, and receipt of governmental support. Measures included the Perseverative Thinking Questionnaire, Meaning in Life Questionnaire, and serum interleukin (IL)-6 as well as IL-4. Using PROCESS, moderation analyses showed significant interactions between psychological factors and SES in predicting serum cytokines. In the context of high SES only, greater repetitive negative thinking was associated with higher levels of the proinflammatory cytokine IL-6 (p = 0.056) while greater meaning in life was associated with higher levels of the antiinflammatory cytokine IL-4 (p = 0.02). Findings from this study suggest that the benefits of these psychological factors on cytokine levels may be most readily observable among women with greater economic stability. Identifying psychological factors that positively contribute to biological functioning in women experiencing heightened economic distress will be crucial in addressing SES-related disparities in perinatal health.

Melatonin modulates autophagy and inflammation protecting human placental trophoblast from hypoxia/reoxygenation.

Melatonin has been proposed as a possible treatment for the deleterious effects of hypoxia/reoxygenation (H/R), such as autophagy, inflammation, and apoptosis. Pathological pregnancies, such as preeclampsia, are associated with placental H/R, and decreased placental melatonin synthesis as well as lower melatonin levels in the placenta and maternal plasma. However, the effects of exogenous melatonin on inflammation and autophagy induced by pregnancy complications associated with H/R await investigation. This study aimed to determine as to whether melatonin protects human primary villous trophoblasts against H/R-induced autophagy, inflammation, and apoptosis. Human primary villous cytotrophoblasts were isolated and immunopurified from normal term placentas. These cells were then exposed or not to 1 mmol/L melatonin for 72 hour in normoxia (8% O2 ), thereby inducing differentiation into syncytiotrophoblast that was then exposed to H/R (0.5% O2 , for 4 hour) or normoxia. H/R decreased endogenous melatonin synthesis (by 68%) and interleukin (IL)-10 levels (by 72%), coupled to increased tumor necrosis factor (TNF) (by 114%), IL-6 (by 55%), and NFκB (by 399%), compared to normoxia. Melatonin treatment reversed the H/R effect, restoring IL-10, TNF, and IL-6 levels to those of the normoxia condition. Melatonin, as well as NFκB inhibition, enhanced autophagy activation, consequently increasing syncytiotrophoblast survival in H/R conditions. This study suggests that H/R, which is present in pregnancy complications, inhibits endogenous melatonin production, thereby contributing to reduced syncytiotrophoblast viability. Results indicate that exogenous melatonin treatment may afford protection against H/R-induced damage, thereby enhancing placental cell survival, and contributing to improved fetal outcomes.

The Effect of Inhalant Organic Dust on Bone Health.

PURPOSE OF REVIEW: Agriculture remains a major economic sector globally, and workers experience high rates of chronic inflammatory lung and musculoskeletal diseases. Whereas obstructive pulmonary diseases are known risk factors for bone loss, the underlying relationship between lung inflammation and bone health is not well known. RECENT FINDINGS: An agriculture organic dust extract inhalation animal model has recently linked lung injury-induced inflammation to systemic bone loss. This process is dependent upon lipopolysaccharide and the toll-like receptor 4 (TLR4) signaling pathway. Downstream systemic interleukin-6 is a key mediator that subsequently activates osteoclastogenesis. Age is a host factor that impacted bone disease with younger mice demonstrating increased susceptibility to bone loss following inhalant exposures as compared to older mice. Supplemental dietary vitamin D was shown to prevent organic dust-induced bone loss, but not lung disease, in animals. Recent animal studies provide new mechanistic insight into the lung-bone inflammatory axis. Host factors, diet, and lipopolysaccharide/TLR4 signaling pathways play a significant role in explaining how inhalant organic dust exposures impact bone health. These investigations might lead to specific targeted therapeutic approaches.

TRPV4 Channel-Regulated ATP Release Contributes to γ-Irradiation-Induced Production of IL-6 and IL-8 in Epidermal Keratinocytes.

External stimuli, such as radiation, induce inflammatory cytokine and chemokine production in skin, but the mechanisms involved are not completely understood. We previously showed that the P2Y11 nucleotide receptor, p38 mitogen-activated protein kinase (MAPK) and nuclear factor-kappa B (NF-κB) all participate in interleukin (IL)-6 production induced by γ-irradiation. Here, we focused on the transient receptor potential vanilloid 4 (TRPV4) channel, which is expressed in skin keratinocytes and has been reported to play a role in inflammation. We found that irradiation of human epidermal keratinocytes HaCaT cells with 5 Gy of γ-rays (137Cs: 0.75 Gy/min) induced IL-6 and IL-8 production. HaCaT cells treated with TRPV4 channel agonist GSK1016790A also showed increased IL-6 and IL-8 production. In both cases, IL-6/IL-8 production was not increased at 24 h after stimulation, but was increased at 48 h. ATP was released from cells exposed to γ-irradiation or TRPV4 channel agonist, and the release was suppressed by TRPV4 channel inhibitors. The γ-irradiation-induced increase in IL-6 and IL-8 production was suppressed by apyrase (ecto-nucleotidase), NF157 (selective P2Y11 receptor antagonist) and SB203580 (p38 MAPK inhibitor). GSK1016790A-induced inhibitor of kappa B-alpha (IκBα) decomposition, which causes NF-κB activation was suppressed by NF157 and SB203580, and γ-irradiation-induced IκBα decomposition was suppressed by TRPV4 channel inhibitors. Our results suggest that γ-irradiation of keratinocytes induces ATP release via activation of the TRPV4 channel, and then ATP activates P2Y11 receptor and p38 MAPK-NF-κB signaling, resulting in IL-6/IL-8 production.

IL-6 is an independent predictive factor of drug survival after dose escalation of infliximab in patients with rheumatoid arthritis.

OBJECTIVE: We aimed to investigate factors predictive of increased serum infliximab (IFX) concentration with improvement of disease activity, as well as better 1-year continuation rate after dose escalation, in patients with rheumatoid arthritis (RA) who showed inadequate response to 3 mg/kg IFX. METHODS: Among 42 patients allotted to receive 3 mg/kg IFX, 13 patients showed adequate response (DAS28 < 3.2) and 29 patients required dose escalation to 4.5 or 6 mg/kg after inadequate response (DAS28 ≥ 3.2) to 3 mg/kg IFX. DAS28, mHAQ, serum level of CRP, interleukin (IL)-6, IL-17, anti-infliximab antibody (AIA) titers and IFX concentration before and on average 2.7 months after dose escalation were examined to explore the baseline factors predictive of a clinically beneficial increase of serum IFX concentration and drug survival. RESULTS: One year after IFX dose escalation, 25 patients completed the study protocol, and 16 patients (64%) continued to show a good response for one year, while 9 patients (36%) required switching of biologics because of inadequate response. Multivariate analyses revealed that a serum IL-6 level of less than 4.0 pg/mL at baseline was the only factor predictive of a clinically beneficial increase of serum IFX concentration in patients who required dose escalation. Receiver operating characteristic analysis revealed that 5.16 pg/mL of IL-6 was the cut-off value with sensitivity 0.833 and specificity of 0.769 (95%CI for AUC: 0.712-1.006). In patients with IL-6 levels of less than 5.16 pg/mL at baseline, the serum IFX concentration significantly increased after dose escalation with adequate response. The 1-year drug survival rates of patients with IL-6 levels less than 5.16 pg/mL and in those with levels greater than or equal to 5.16 pg/mL at baseline were 83.3% and 30.8%, respectively (log-rank test, p = .011). CONCLUSIONS: The results of our study indicated that a baseline serum level of IL-6 below 5.16 pg/mL might be a predictive factor for a clinically beneficial increase of serum IFX concentration with improvement of disease activity and better 1-year continuation rate after IFX dose escalation.

Rheumatoid arthritis fibroblast-like synoviocytes co-cultured with PBMC increased peripheral CD4+ CXCR5+ ICOS+ T cell numbers.

'Circulating' T follicular helper cells (Tfh), characterized by their surface phenotypes CD4+ chemokine receptor 5 (CXCR5)+ inducible co-stimulatory molecule (ICOS)+ , have been identified as the CD4+ T cell subset specialized in supporting the activation, expansion and differentiation of B cells. Fibroblast-like synoviocytes (FLS) are critical in promoting inflammation and cartilage destruction in rheumatoid arthritis (RA), and the interaction between FLS and T cells is considered to facilitate FLS activation and T cell recruitment. However, it remains unknown whether RA-FLS co-cultured with activated peripheral blood mononuclear cells (PBMC) has immunoregulatory effects on peripheral Tfh. In the present study, we co-cultured RA-FLS with or without anti-CD3/CD28-stimulated PBMC. The results showed that RA-FLS co-cultured with stimulated PBMC could increase the numbers of CD4+ CXCR5+ ICOS+ T cells of RA PBMC possibly via the production of interleukin (IL)-6, a critical cytokine involved in the differentiation of Tfh cells. We also observed increased reactive oxygen species (ROS) levels in the co-culture system of RA-FLS and PBMC. The percentage of CD4+ CXCR5+ ICOS+ T cells was decreased when ROS production was inhibited by N-acetyl-L-cysteine (NAC), a specific inhibitor which can decrease ROS production. In addition, we showed that the higher levels of tumour necrosis factor (TNF)-α and IL-1ß in the co-culture system and the blocking of TNF receptor 2 (TNF-R2) and IL-1ß receptor (IL-1ßR) both decreased the numbers of CD4+ CXCR5+ ICOS+ T cells. Our study reveals a novel mechanistic insight into how the interaction of RA-FLS and PBMC participates in the RA pathogenesis, and also provides support for the biologicals application for RA.

Oncolytic virus efficiency inhibited growth of tumour cells with multiple drug resistant phenotype in vivo and in vitro.

BACKGROUND: Tumour resistance to a wide range of drugs (multiple drug resistant, MDR) acquired after intensive chemotherapy is considered to be the main obstacle of the curative treatment of cancer patients. Recent work has shown that oncolytic viruses demonstrated prominent potential for effective treatment of diverse cancers. Here, we evaluated whether genetically modified vaccinia virus (LIVP-GFP) may be effective in treatment of cancers displaying MDR phenotype. METHODS: LIVP-GFP replication, transgene expression and cytopathic effects were analysed in human cervical carcinomas KB-3-1 (MDR-), KB-8-5 (MDR+) and in murine melanoma B-16 (MDR-), murine lymphosarcomas RLS and RLS-40 (MDR+). To investigate the efficacy of this therapy in vivo, we treated immunocompetent mice bearing murine lymphosarcoma RLS-40 (MDR+) (6- to 8-week-old female CBA mice; n = 10/group) or melanoma B-16 (MDR-) (6- to 8-week-old female C57Bl mice; n = 6/group) with LIVP-GFP (5 × 10(7) PFU of virus in 0.1 mL of IMDM immediately and 4 days after tumour implantation). RESULTS: We demonstrated that LIVP-GFP replication was effective in human cervical carcinomas KB-3-1 (MDR-) and KB-8-5 (MDR+) and in murine melanoma B-16 (MDR-), whereas active viral production was not detected in murine lymphosarcomas RLS and RLS-40 (MDR+). Additionally, it was found that in tumour models in immunocompetent mice under the optimized regimen intratumoural injections of LIVP-GFP significantly inhibited melanoma B16 (33 % of mice were with complete response after 90 days) and RLS-40 tumour growth (fourfold increase in tumour doubling time) as well as metastasis. CONCLUSION: The anti-tumour activity of LIVP-GFP is a result of direct oncolysis of tumour cells in case of melanoma B-16 because the virus effectively replicates and destroys these cells, and virus-mediated activation of the host immune system followed by immunologically mediated destruction of of tumour cells in case of lymphosarcoma RLS-40. Thus, the recombinant vaccinia virus LIVP-GFP is able to inhibit the growth of malignant cells with the MDR phenotype and tumour metastasis when administered in the early stages of tumour development.