Interleukin-12 is required for interferon-γ production and lethality in lipopolysaccharide-induced shock in mice

Several cytokines, in particular tumor necrosis factor-α (TNF-α) and interferon-γ (IFN-γ), have been shown to be responsible for pathological reactions which may lead to shock and death observed in infection with Gram-negative bacteria and in response to endotoxins (lipopolysaccharides, LPS). Priming of mice with the avirulent Bacille Calmette Guérin (BCG) vaccine strain of Mycobacterium bovis increases the sensitivity of mice to the lethal effect of LPS and results in an efficient priming for cytokine production. In response to low doses (1 γg/mouse) of LPS, BCG-primed mice produce interleukin-12 (IL-12) which controls IFN-γ production, as demonstrated by the ability of neutralizing anti-IL-12 antibodies to suppress IFN-γ production. However, the concentration of the biologically active IL-12 p70 heterodimer is similar in the serum of both BCG-primed or unprimed mice, reaching levels of 1–3 ng/ml at 3–6 h after LPS injection, whereas IFN-γ production was observed only in BCG-primed mice. The priming effect of BCG on IFN-γ production appears to be mostly due to its ability to increase TNF-α production, which acts as cofactor with LPS-induced IL-12 in inducing IFN-γ production, as shown by the ability of injection of TNF-α and LPS (1 γg/mouse), but not LPS alone, to induce IFN-γ production. However, in addition to TNF-α, other LPS-induced cofactor(s) are required in cooperation with IL-12 to induce optimal IFN-γ production, because co-injection of TNF-α and IL-12, sufficient to induce serum concentrations of both cytokines higher and more persistent than those obtained by injection of LPS, was not sufficient to induce IFN-γ production in vivo. Neutralizing anti-IL-12 antibodies, in addition to inhibiting the in vivo LPS-induced IFN-γ production, also completely protect BCG-primed mice injected with up to 10 μg of LPS from shock-induced death. Thus, IL-12 is required for IFN-γ production and lethality in an endotoxic shock model in mice.     

Lipopolysaccharide-induced cytokine production in human monocytes: Role of tyrosine phosphorylation in transmembrane signal transduction

The signal transduction events that follow the binding of lipopolysaccharide (LPS) to the macrophage cell surface are not well defined. In the current studies LPS was found to induce alterations in phosphorylation of monocyte proteins on tyrosine. Herbimycin A and genistein, inhibitors of tyrosine kinases, markedly attenuated LPS-induced tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) protein and mRNA production. Reciprocally, the tyrosine phosphatase inhibitor sodium orthovanadate enhanced LPS-induced production of TNF-α. LPS induced a concentration-dependent increase in tyrosine phosphorylation of several proteins, which paralleled and preceded the onset of LPS-induced TNF-α production. LPS stimulation had different but reproducible effects on three members of the src family of tyrosine kinases. Both Hck and Lyn kinase activity increased before the onset of TNF-α production, consistent with their participation in the observed LPS-induced tyrosine phosphoprotein accumulation. In contrast, Yes kinase activity was not affected. These observations were made at concentrations of LPS that required serum rich in LPS-binding protein and the monocyte surface antigen CD14 for TNF-α production. These data indicate that tyrosine kinases and phosphatases are involved in the signal transduction cascade by which LPS induces production of TNF-α and IL-6 by human monocytes, and suggest that Lyn and Hck are candidate participants in this process.     

Thymulin,A Thymic Peptide,Prevents the Overproduction of Pro-Inflammatory Cytokines and Heat Shock Protein Hsp70 in Inflammation-Bearing Mice

The effects of synthetic analogue of peptide hormone thymulin, which is normally produced by thymic epithelial cells, on immune cells activity and blood cytokine profile had been studied in male NMRI mice with acute inflammation induced by injection of lipopolysaccharide from gram-negative bacteria (LPS, 250 μg/100 g of body weight). Inflammation induced by LPS resulted in accumulation of several plasma pro-inflammatory cytokines, IL-1β, IL-2, IL-6, TNF-α, interferon-γ, and also IL-10, anti-inflammatory cytokine. Thymulin previously injected in dose of 15 μg/100 g body weight, prevented the accumulation of proinflammatory cytokines in plasma. Thymulin also prevented LPS-induced up-regulation of production of several cytokines by spleen lymphocytes and peritoneal macrophages. Added in vitro, thymulin decreased the peak of TNF-α production in macrophages cultivated with LPS. In addition, thymulin lowered the peak of Hsp70 production induced by LPS treatment. The results indicate that thymulin having significant anti-inflammatory effect may be promising in clinical application.     

Increased Pro-inflammatory Cytokine Production After Lipopolysaccharide Stimulation in Patients with X-linked Agammaglobulinemia

Purpose

To evaluate the lipopolysaccharide (LPS)-induced pro-inflammatory cytokine response by peripheral blood mononuclear cells (PBMCs) from XLA patients.

Methods

Thirteen patients with XLA were included in the study. LPS-induced TNF-α, IL-1β, IL-6, and IL-10 production was determined in PBMCs from patients and matched healthy controls by ELISA. Cytokine production was correlated with the severity of mutation, affected domain and clinical characteristics.

Results

In response to LPS, PBMCs from XLA patients produced significantly higher amounts of pro-inflammatory cytokines and IL-10 compared to controls, and this production was influenced neither by the severity of the mutation nor the affected domain. PBMCs from patients with a history of more hospital admissions before their diagnosis produced higher levels of TNF-α. PBMCs from patients with lower serum IgA levels showed a higher production of TNF-α and IL-1β. Less severe (punctual) mutations in the Btk gene were associated with higher serum IgG levels at diagnosis.

Conclusions

Our results demonstrate a predominantly inflammatory response in XLA patients after LPS stimulation and suggest a deregulation of TLR signaling in the absence of Btk. This response may be influenced by environmental factors.     

对脂多糖攻击小鼠血及肝IL-6和TNF-α含量的影响

目的：研究重组人白细胞介素-10（rhIL-10）对脂多糖（LPS）诱导的血、肝IL-6和TNF-α炎症介质含量变化的影响。 方法： 小鼠腹腔注射LPS建立炎症模型，并同时静脉注射不同剂量的rhIL-10，ELISA法测定12 h、24 h、48 h和72 h肝组织和血清IL-6和TNF-α的含量。 结果： 注射rhIL-10后12 h，肝组织和血清IL-6、TNF-α水平开始下调，24-48 h抑制作用最明显（P＜0.05），72 h后抑制作用减弱，且呈剂量效应关系。 结论： 利用基因工程技术制备的重组人白细胞介素10（rhIL-10）显著下调肝组织和血清IL-6和TNF-α的水平。     

Cavidine Ameliorates Lipopolysaccharide-Induced Acute Lung Injury <Emphasis Type="Italic">via</Emphasis> NF-κB Signaling Pathway <Emphasis Type="Italic">in vivo</Emphasis> and <Emphasis Type="Italic">in vitro</Emphasis>

Acute lung injury (ALI) is characterized by widespread inflammation in the lungs and alveolar-capillary destruction, causing high morbidity and mortality. Cavidine, isolated from Corydalis impatiens, have been exhibited to have potent anti-inflammatory effects in previous studies. The purpose of this study was to evaluate the protective effect of cavidine on lipopolysaccharide (LPS)-induced ALI and to enunciate the underlying in vivo and in vitro mechanisms. Mice were intraperitoneally administrated with cavidine (1, 3, or 10 mg/kg) at 1 and 12 h, prior to the induction of ALI by intranasal administration of LPS (30 mg/kg). Blood samples, lung tissues, and bronchoalveolar lavage fluid (BALF) were harvested after LPS challenge. Furthermore, we used LPS-induced lung epithelial cells A549 to examine the mechanism of cavidine to lung injury. The results showed that pretreatment with cavidine significantly decreased lung wet-to-dry weight (W/D) ratio, reduced pro-inflammatory cytokine levels including TNF-α and IL-6 in BALF and serum from LPS-stimulated mice, and attenuated lung histopathological changes. In addition, western blot results showed that cavidine inhibited the phosphorylation of nuclear factor-kappaB (NF-κB) p65 and IκBα induced by LPS. In conclusion, our results demonstrate that cavidine protects against LPS-induced acute lung injury in mice via inhibiting of pro-inflammatory cytokine TNF-α and IL-6 production and NF-κB signaling pathway activation. Taken together, cavidine may be useful for the prevention and treatment of pulmonary inflammatory diseases, such as ALI.     

Inhibition of pro-inflammatory cytokines and inducible nitric oxide by extract of Emilia sonchifolia L. aerial parts

Emilia sonchifolia L. (Asteraceae) is used in ethnomedicine for the treatment of a wide array of inflammatory disorders. This practice has also been supported by scientific reports which showed that extracts of E. sonchifolia possess anti-inflammatory effects in rodents. However, the mechanism(s) through which the extracts produce these effects is not known. In this study, the effect of a methanol/methylene chloride extract of E. sonchifolia (ES) on the levels of IL-1β and TNF-α after an intraperitoneal lipopolysaccharide (LPS; 1?mg/kg) challenge was investigated in mice. The effect of ES on TNF-α and inducible nitric oxide (iNO) production by LPS-stimulated bone marrow-derived macrophages (BMMDM) was also investigated in vitro. BMMDM were pre-incubated for 2?h with ES (20, and 100 μg/mL) or with Pyrrolidine dithiocarbamate, PDTC (100 µM) and then activated with LPS, and then the IL-1β, TNF-α and NO production measured in the cell-free conditioned culture supernatant after 24?h of incubation. In groups of mice pre-treated with ES, the systemic levels of IL-1β and TNF-α induced by LPS were found to be significantly (p < 0.05) lower. In vitro, ES treatment caused a concentration-dependent decrease in LPS-inducible IL-1β, TNF-α, and NO production by BMDM compared to the effects of treatment of the cells with LPS alone without affecting the viability of the cells. The results of these studies suggest that treatment with ES alleviated inflammatory responses possibly through a suppression of pro-inflammatory mediators and cytokines such as IL-1β, TNF-α, and iNO.     

Cepharanthine, an Alkaloid from Stephania cepharantha Hayata, Inhibits the Inflammatory Response in the RAW264.7 Cell and Mouse Models

The aim of this study was to investigate the protective effects of cepharanthine (CEP) on inflammation in lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro and a LPS-induced lung injury model in vivo. RAW264.7 cells were treated with various concentrations of CEP for 1 h followed by incubation with or without 1 μg/ml LPS for 18 h. TNF-α, IL-6, and IL-1β in the supernatants were measured by ELISA. Nuclear factor-κB (NF-κB) and mitogen-activated protein kinase pathways were analyzed by Western blot. Mice were randomly divided into control group, LPS group, CEP?+?LPS group, and dexamethasone?+?LPS group. A male BALB/c mouse model of acute lung injury was induced by LPS. Bronchoalveolar lavage fluid was collected for inflammatory cell count and cytokine assays. Histopathologic examination was performed on mice that were not subjected to bronchoalveolar lavage fluid collection. CEP dose-dependently inhibited the release of TNF-α, IL-6, and IL-1β in LPS-stimulated RAW264.7 cells. Significantly, CEP dose-dependently suppressed NF-κB activation, IκBα degradation, and phosphorylation of ERK, JNK, and p38 induced by LPS. In vivo, it was also observed that CEP attenuated lung histopathologic changes and down-regulated the level of pro-inflammatory cytokines, including TNF-α, IL-1β, and IL-6, in the mouse acute lung injury model. These results suggest that CEP potentially decreases inflammation in vitro and in vivo and might be a therapeutic agent against inflammatory diseases.     

Anti-inflammatory Role of Pilose Antler Peptide in LPS-Induced Lung Injury

The present study was designed to investigate the effects of pilose antler peptide (PAP) on lipopolysaccharide (LPS)-induced lung injury. BalB/c mice intraperitoneally received PAP (10 and 20 mg/kg) or dexamethasone (2 mg/kg) 1 h prior to intratracheal instillation of LPS. PAP significantly decreased lung wet-to-dry weight (W/D) ratio and lung myeloperoxidase (MPO) activity and restored LPS-induced lung histopathological changes. PAP also increased super oxide dismutase (SOD) level and inhibited malondialdehyde (MDA) content and levels of pro-inflammatory cytokines including tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6) in bronchoalveolar lavage fluid (BALF) in LPS-stimulated mice. Furthermore, we demonstrated that PAP inhibited Rho/NF-κB pathway in LPS-induced mice. Our experimental results indicated that the protective mechanism of PAP might be attributed partly to the inhibition of Rho/NF-κB pathway.     

Suppression of IL-12 production by phosphodiesterase inhibition in murine endotoxemia is IL-10 independent

Phosphodiesterase (PDE) inhibitors are potent regulators of various immune processes. Immune cells contain type IV and type III PDE. Here we studied in mice the effects of rolipram, a selective PDE IV inhibitor, and amrinone, a selective PDE III blocker, on plasma levels of IL-12 (p70), IFN-γ, IL-1, TNF-α, and nitric oxide (NO) induced by intraperitoneal injection of Escherichia coli lipopolysaccharide (LPS) (80 mg/kg). Pretreatment of BALB/c mice with both rolipram (1 – 25 mg/kg) and amrinone (10 – 100 mg/kg) decreased plasma IL-12 levels in a dose-dependent manner. Similarly, LPS-elicited plasma IFN-γ concentrations were suppressed by both rolipram and amrinone. However, LPS-induced plasma IL-1α levels were not affected by either of these compounds. In addition, rolipram inhibited IL-12, IFN-γ, TNF-α and nitrite/nitrate (breakdown products of NO) production in C57BL/6 IL-10^+/+ mice as well as in their IL-10-deficient counterparts (C57BL/6 IL-10^−/−). Our results suggest that rolipram and amrinone decrease the immune activation in endotoxemia through inhibition of the production of pro-inflammatory mediators IL-12, IFN-γ, TNF-α and NO. These effects are not the consequences of the increase in IL-10 production by PDE inhibition.     

Commensal microbiota induce LPS hyporesponsiveness in colonic macrophages via the production of IL-10

Several subsets of innate immune cells, all with unique properties, reside within the intestinal lamina propria. However, compared with intestinal dendritic cells (DCs), intestinal macrophages are less well characterized. In this study, we examined the properties of macrophages in the colonic lamina propria (LMφ). Colonic DCs (LDC) showed LPS-induced production of IL-12p40. In contrast, LMφ showed constitutive IL-10 production and unresponsiveness to LPS in terms of inflammatory cytokine production. Comparison of the gene expression profiles between LMφ and LDC revealed that LMφ preferentially expressed IL-10-related genes. LMφ obtained from mice lacking IL-10 or Stat3 showed hyperproduction of tumour necrosis factor (TNF)-α and IL-6 in response to LPS. IL-10 production in the large intestine was mainly induced by LMφ and regulatory T cells and was dependent on the presence of commensal microbiota. Accordingly, LMφ from germ-free mice showed less production of IL-10 and increased levels of LPS-induced TNF-α and IL-6 production. Taken together, these results demonstrate that the activity of LMφ to produce pro-inflammatory cytokines is negatively regulated through commensal microbiota-dependent IL-10 production in the large intestine.     

TNF-alpha Production by Peripheral Blood Monocytes in Multiple Sclerosis Patients and Healthy Controls

Background: Aberrant immune responses are evident in the pathogenesis of multiple sclerosis (MS) and it has been proposed that the spectrum of cytokines influence disease outcomes. Leptin and lipopolysaccharide (LPS) of Gram-negative bacteria are both potent cellular stimulators for production of pro-inflammatory cytokines such as tumor necrosis factor-α (TNF-α). The aim of this study was to compare the TNF-α production by peripheral blood monocytes from MS patients with healthy controls.

Methods: Peripheral blood samples were stimulated with LPS or leptin. After blocking the Golgi apparatus, intracellular cytokine production was assessed using a monoclonal antibody against human TNF-α by the flow cytometry technique. Moreover, plasma level measurement of cytokines was performed using enzyme-linked immunosorbent assay (ELISA).

Results: Intracellular levels of TNF-α were 16.80?±?8.21 and 16.52?±?8.23in MS patients and healthy controls which showed no statistically significant difference between them (p?=?0.850). Leptin-stimulated and LPS-stimulated TNF-α production showed no significant difference between MS patients and the control group (p?=?0.263 and p?=?0.191, respectively). However, after treatment with leptin, a weak significant difference was shown between cases and control group (p?=?0.049). There were significant differences between cases and controls regarding serum levels of IL-6 and Toll-like receptor-4 (TLR-4) before and after stimulation with leptin and LPS, separately (p?<?0.05).

Conclusion: Taken together, we cannot definitely conclude that TNF-α does not play an important role in pathogenesis of MS. However, other characteristics of monocyte activation such as IL-6 or TLRs can elucidate implication of peripheral blood monocytes in MS pathogenesis.     

肾上腺素对小鼠巨噬细胞中促炎／抗炎介质比值的影响

目的：研究肾上腺素对脂多糖（LPS）诱导的小鼠单核巨噬细胞株RAW264.7中促炎介质［肿瘤坏死因子（TNF-α）、一氧化氮（NO）、环加氧酶-2（COX-2）］和抗炎介质［血红素氧化酶-1（HO-1）、白介素10（IL-10）］表达及NF-κB活化的影响。 方法： 以10 μg/L的LPS刺激体外培养的RAW264.7细胞作为炎症模型，加入不同浓度的肾上腺素（1、5、10、50 μmol/L）孵育24 h后，收集培养上清并提取细胞总蛋白，酶联免疫法测定上清中TNF-α、IL-10浓度，Griess法检测上清NO含量(以NO2-/NO3-表示)，免疫印迹法检测细胞总蛋白中COX-2、HO-1、IκB-α的含量。 结果： 10 μg/L的LPS明显诱导TNF-α、NO(NO2-/NO3-)、COX-2、IL-10及HO-1的产生；LPS+肾上腺素组与LPS单独作用组相比促炎介质TNF-α、NO(NO2-/NO3-)、COX-2的表达量显著下降，而抗炎介质IL-10、HO-1的表达却明显增强；肾上腺素与LPS共同作用组中IκB-α的含量与单独LPS作用组相比无明显差异。 结论： 肾上腺素下调LPS诱导的巨噬细胞中促炎介质的表达同时促进抗炎介质的表达，这种效应并不通过影响NF-κB的活化来实现。     

Cytokine Inhibition by A Novel Steroid,Mometasone Furoate

Abstract

Mometasone furoate (9α, 21 dichloro-11β, 17α dihydroxy-16α methyl-1, 4 pregnadiene-3, 20 dione-17–[2′] furoate) was an unexpectedly potent inhibitor of the in vitro production of three inflammatory cytokines, IL-11, IL-6, and TNF-α. the potency of mometasone furoate in inhibiting cytokine production was compared to that of hydrocortisone, betamethasone, dexamethasone, and beclomethasone.

IL-6 and TNF-α were both produced by WEHI-265.1 (murine myelomonocytic leukemia) cells following stimulation by lipopolysaccharide (LPS). Twenty-four hours after stimulation by LPS, the cell-free supernatant fluids were removed. Their cytokine content was analyzed using ELISAs specific for each cytokine.

IL-1 synthesis was induced in the harvested peritoneal macrophages of BALB/c mice by incubation with LPS for twenty-four hours. the IL-1 content in the cell-free supernatant fluids was determined by the thymocyte-costimulator bioassay.

Using these systems, mometasone furoate was found to be the most potent steroid tested for inhibiting the production of the three cytokines. the IC50′s were 0.05 nM (IL-1), 0.15 nM (IL-6), and 0.25 nM (TNF-α). the inhibition of the production of proinflammatory mediators by extremely low concentrations of mometasone furoate suggests that this steroid should be highly effective in various disorders.     

Protective effect of taraxasterol against LPS-induced endotoxic shock by modulating inflammatory responses in mice

Taraxasterol, a pentacyclic-triterpene, was isolated from the Chinese medicinal herb Taraxacum officinale. In the present study, we investigated the protective effect of taraxasterol on murine model of endotoxic shock and the mechanism of its action. Mice were treated with 2.5, 5 and 10?mg/kg of taraxasterol prior to a lethal dose of lipopolysaccharide (LPS) challenge. Survival of mice was monitored twice a day for 7 days. To further understand the mechanism, the serum levels of inflammatory cytokine tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-1β (IL-1β), interleukin-6 (IL-6) and mediator nitric oxide (NO), prostaglandin E₂ (PGE₂) as well as histology of lungs were examined. The results showed that taraxasterol significantly improved mouse survival and attenuated tissue injury of the lungs in LPS-induced endotoxemic mice. Further studies revealed that taraxasterol significantly reduced TNF-α, IFN-γ, IL-1β, IL-6, NO and PGE₂ levels in sera from mice with endotoxic shock. These results indicate that taraxasterol has a protective effect on murine endotoxic shock induced by LPS through modulating inflammatory cytokine and mediator secretion. This finding might provide a new strategy for the treatment of endotoxic shock and associated inflammation.     

Differential regulation of monocytic tumor necrosis factor-α and interleukin-10 expression

Activation of human monocytes by bacterial endotoxin (LPS) results in an initial burst of inflammatory cytokines like tumor necrosis factor (TNF)-α which is followed by the secretion of anti-inflammatory mediators like interleukin (IL)-10. The signaling pathways in IL-10 induction are unknown. Here, we show that the regulation of IL-10 expression is more complex than that of TNF-α. LPS-induced TNF-α and IL-10 expression requires early activation of protein tyrosine kinases (PTK). Moreover, delayed addition of PTK inhibitors blocked IL-10, but not TNF-α, suggesting the impact of a late PTK activity. Two inducers of PTK activity are the downstream mediators of LPS activation, TNF-α and cyclic adenosine monophosphate (cAMP). Both mediators synergistically up-regulate IL-10 expression. Downstream of PTK activation, they use distinct pathways. TNF-α, but not cAMP-induced IL-10 gene expression was inhibited by pyrrolidine dithiocarbamate, suggesting the involvement of reactive oxygen species. Inhibition of protein kinase C (PKC) suppressed LPS-induced TNF-α and IL-10 expression as well, but, unlike TNF-α, direct activation of PKC by phorbol 12-myristate 13-acetate (PMA) did not induce IL-10 expression. Furthermore, PKC is not involved in late events of IL-10 activation, as delayed addition of PKC inhibitors did not suppress LPS-induced IL-10 expression and did not influence cAMP- or TNF-α-induced IL-10. The modulation of IL-10 expression by inflammatory mediators suggests a regulatory circuit of the inflammatory response.     

p-Cymene Modulates In Vitro and In Vivo Cytokine Production by Inhibiting MAPK and NF-κB Activation

The present study was designed to investigate the effects of p-cymene on lipopolysaccharide (LPS)-induced inflammatory cytokine production both in vitro and in vivo. The production of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), and interleukin-10 (IL-10) in LPS-stimulated RAW 264.7 cells and C57BL/6 mice was evaluated by sandwich ELISA. Meanwhile, the mRNA levels of cytokine genes were examined in vitro by semiquantitative RT-PCR. In a further study, we analyzed the activation of nuclear factor-κB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling pathways by western blotting. We found that p-cymene significantly regulated TNF-α, IL-1β, and IL-6 production in LPS-stimulated RAW 264.7 cells. Furthermore, the levels of relative mRNAs were also found to be downregulated. In in vivo trail, p-cymene markedly suppressed the production of TNF-α and IL-1β and increased IL-10 secretion. We also found that p-cymene inhibited LPS-induced activation of extracellular signal receptor-activated kinase 1/2, p38, c-Jun N-terminal kinase, and IκBα. These results suggest that p-cymene may have a potential anti-inflammatory action on cytokine production by blocking NF-κB and MAPK signaling pathways.     

Hesperidin Alleviates Lipopolysaccharide-Induced Neuroinflammation in Mice by Promoting the miRNA-132 Pathway

Previous studies have demonstrated that hesperidin, a flavanone glycoside from citrus fruits, produces antidepressant-like effects in both mice and rats. However, whether these effects are mediated by pro-inflammatory cytokines remains unknown. In the present study, we attempted to investigate the effects of hesperidin on the depressive-like behavior; the serum corticosterone concentrations; and the interleukin (IL)-1β, IL-6, and tumor necrosis factor alpha (TNF-α) levels in lipopolysaccharide (LPS)-induced depression-like mice. In particular, we evaluated the miRNA-132 expression after LPS and hesperidin treatment. We found that LPS injection not only decreased the sucrose preference and increased the serum corticosterone levels but also elevated IL-1β, IL-6, and TNF-α in the prefrontal cortex. More importantly, LPS down-regulated the expression of miRNA-132. Pre-treatment with hesperidin (25, 50, 100 mg/kg) for 7 days prevented these abnormalities induced by LPS injection. In contrast, this effect of hesperidin was abolished by a miRNA-132 antagomir. Taken together, these results suggest that the antidepressant-like mechanisms of hesperidin are at least partially related to decreased pro-inflammatory cytokine levels via the miRNA-132 pathway in the brain.     

Anti-inflammatory activity of phosphodiesterase (PDE)-IV inhibitors in acute and chronic models of inflammation

Inhibitors of cyclic nucleotide phosphodiesterases are known to suppress lipopolysaccharide (LPS)-induced tumour necrosis factor-alpha (TNF-α) production in vitro in human monocytes. The most potent of these have selectivity for type IV PDEs, suggesting that this class of PDE is the major type involved in the regulation of human TNF-α production. Using compounds of two distinct chemical structural classes, a quinazolinedione (CP-77 059) and a 4 arylpyrrolidinone (rolipram). we show here that PDE-IV-specific inhibitors are also potent in suppressing LPS-induced TNF-α production in vitro in sodium periodate-elicited murine macrophages (IC₅₀s of 1 and 33, respectively). We then report the in vivo anti-inflammatory effect of PDE-IV inhibition in five murine models of inflammation: (i) elevation of serum TNF-α induced by a subtethal LPS injection; (ii) LPS-induced endotoxic shock; (iii) LPS/galactosamine-induced endotoxic shock; (iv) carrageenan-induced paw oedema; and (v) adjuvant arthritis. Following a sublethal (5 μg/mouse) injection of LPS, serum TNF-α levels in mice peaked sharply, reaching concentrations of 3–12 ng/ ml 90 min after injection. In this sublethal LPS assay, CP-77 059 was about 30 times more potent than rolipram, with a minimum effective dose of 0.1 mg/kg versus 3 mg/kg for rolipram. This rank order is in keeping with the relative in vitro IC₅₀S for CP-77059 and rolipram, as well as their relative Ki against the human PDE-IV enzyme (46 nM and 220 nM, respectively). In LPS-induced endotoxic shock, rolipram and CP-77 059 at relatively high doses of 30 and 10 mg/kg, respectively, significantly reduced serum TNF-α levels, and also inhibited mortality 66%. In the LPS/galactosamine shock model, in which mice are rendered exquisitely sensitive to LPS by co-injection with galactosamine, only 0.1 μg of LPS/mouse Is necessary for serum TNF-α elevation and death. Both rolipram and the CP-77059 caused dose-dependent reduction of serum TNF-α and lethality. In the carrageenan-induced paw oedema model, in which there is a pronounced local TNF-α response (without a serum TNF-α elevation), rolipram significantly inhibited paw swelling as well as localized TNF-α levels in the paw. In the adjuvant arthritis model, a chronic model of inflammation also possessing localized TNF-α elevation in the inflamed paw, rolipram and CP-77059 suppressed ankle swelling and radiological evidence of joint damage. These data are consistent with a major role for PDE-IV in regulation of TNF-α production and inflammatory responses in murine systems. It suggests a potential therapeutic use for PDE-IV-specific inhibitors in inflammatory disease such as rheumatoid arthritis, septic shock and other inflammatory diseases where TNF-α has been postulated to be a contributing factor in the pathology of the disease.