Modulation of TNF-alpha gene expression by IFN-gamma and pamidronate in murine macrophages: regulation by STAT1-dependent pathways

Adhesion between EVs and tumor cells facilitated EV-encapsulated doxorubicin delivery via ICAM1

Doxorubicin (Dox) is an anti-tumor drug with a broad spectrum, whereas the cardiotoxicity limits its further application. In clinical settings, liposome delivery vehicles are used to reduce Dox cardiotoxicity. Here, we substitute extracellular vesicles (EVs) for liposomes and deeply investigate the mechanism for EV-encapsulated Dox delivery. The results demonstrate that EVs dramatically increase import efficiency and anti-tumor effects of Dox in vitro and in vivo, and the efficiency increase benefits from its unique entry pattern. Dox-loading EVs repeat a "kiss-and-run" motion before EVs internalization. Once EVs touch the cell membrane, Dox disassociates from EVs and directly enters the cytoplasm, leading to higher and faster Dox import than single Dox. This unique entry pattern makes the adhesion between EVs and cell membrane rather than the total amount of EV internalization the key factor for regulating the Dox import. Furthermore, we recognize ICAM1 as the molecule mediating the adhesion between EVs and cell membranes. Interestingly, EV-encapsulated Dox can induce ICAM1 expression by irritating IFN-γ and TNF-α secretion in TME, thereby increasing tumor targeting of Dox-loading EVs. Altogether, EVs and EV-encapsulated Dox synergize via ICAM1, which collectively enhances the curative effects for tumor treatment.

Clinical Treatment Options in Scleroderma: Recommendations and Comprehensive Review

There are two major clinical subsets of scleroderma: (i) systemic sclerosis (SSc) is a complex systemic autoimmune disorder characterized by inflammation, vasculopathy, and excessive fibrosis of the skin and multiple internal organs and (ii) localized scleroderma (LoS), also known as morphea, is confined to the skin and/or subcutaneous tissues resulting in collagen deposition and subsequent fibrosis. SSc is rare but is associated with significant morbidity and mortality compared with other rheumatic diseases. Fatal outcomes in SSc often originate from organ complications of the disease, such as lung fibrosis, pulmonary artery hypertension (PAH), and scleroderma renal crisis (SRC). Current treatment modalities in SSc have focused on targeting vascular damage, fibrosis, and regulation of inflammation as well as autoimmune responses. Some drugs previously used in an attempt to suppress fibrosis, like D-penicillamine (D-Pen) or colchicine, have been disappointing in clinical practice despite anecdotal evidence of their advantages. Some canonical medications, including glucocorticoids, immunosuppressants, and vasodilators, have had some success in treating various manifestations in SSc patients. Increasing evidence suggests that some biologic agents targeting collagen, cytokines, and cell surface molecules might have promising therapeutic effects in SSc. In recent years, hematopoietic stem cell transplantation (HSCT), mostly autologous, has made great progress as a promising treatment option in severe and refractory SSc. Due to the complexity and heterogeneity of SSc, there are currently no optimal treatments for all aspects of the disease. As for LoS, local skin-targeted therapy is generally used, including topical application of glucocorticoids or other immunomodulatory ointments and ultraviolet (UV) irradiation. In addition, systemic immunosuppressants are also utilized in several forms of LoS. Here, we comprehensively discuss current treatment options for scleroderma, encompassing old, new, and future potential treatment options. In addition, we summarize data from new clinical trials that have the potential to modify the disease process and improve long-term outcomes in SSc.

Differential regulation of JAK/STAT-signaling in patients with ulcerative colitis and Crohn’s disease

In 2018, the pan-Janus kinase (JAK) inhibitor tofacitinib was launched for the treatment of ulcerative colitis (UC). Although tofacitinib has proven efficacious in patients with active UC, it failed in patients with Crohn’s disease (CD). This finding strongly hints at a different contribution of JAK signaling in both entities. Here, we review the current knowledge on the interplay between the JAK/signal transducer and activator of transcription (STAT) pathway and inflammatory bowel diseases (IBD). In particular, we provide a detailed overview of the differences and similarities of JAK/STAT-signaling in UC and CD, highlight the impact of the JAK/STAT pathway in experimental colitis models and summarize the published evidence on JAK/STAT-signaling in immune cells of IBD as well as the genetic association between the JAK/STAT pathway and IBD. Finally, we describe novel treatment strategies targeting JAK/STAT inhibition in UC and CD and comment on the limitations and challenges of the new drug class.

Role of Reactive Oxygen Species in the Cytotoxicity of Arsenic Trioxide and Pamidronate for Human Prostate Cancer Cells

To examine whether combining arsenic trioxide (ARS) and pamidronate (PAM), anticancer drugs that generate reactive oxygen species (ROS), enhanced targeting of redox sensitive growth signals, we studied cloning efficiency, protein tyrosine phosphatase (PTPase) activity, and epidermal growth factor receptor (EGFR) phosphorylation in DU-145 and PC-3 human prostate cancer cells in response to treatment with ARS and/or PAM for 24 h. IC₅₀ concentrations in a clonogenic assay for ARS and PAM were 9 and 20 μM, respectively, in DU-145 cells; and 2 and 12 μM, in PC-3 cells. When combined, ARS and PAM demonstrated additive cytotoxicity in the DU-145 line (combination index [CI] of 1.10) and synergy for PC-3 cells (CI of 0.86). ARS (20 μM for 24 h) inhibited PTPase activity by 36 ± 7 %, p < 0.05 vs. untreated controls, in DU-145 cells; and by 58 ± 8%, p < 0.05, in the PC-3 line. PAM (20 μM for 24 h) decreased PTPase activity by 24 ± 9%, p = 0.06, and 8 ± 1%, p < 0.01, in DU-145 and PC-3 cells, respectively. Combining ARS and PAM significantly inhibited PTPase activity in both cell lines at lower concentrations of each drug. Pretreatment with N-acetyl-L-cysteine reversed ARS- and PAM-induced inhibition of PTPase activity. PTPase inhibition by ARS and/or PAM treatment in both DU-145 and PC-3 cells was associated with prolonged EGFR activation. These experiments demonstrate additive or synergistic cell killing by the ARS/PAM combination in DU-145 or PC-3 cells and suggest that enhanced antitumor activity may be related to alterations in receptor tyrosine kinase signaling that occur, in part, due to ROS-mediated PTPase inhibition.

Heredity of type 2 diabetes confers increased susceptibility to oxidative stress and inflammation

INTRODUCTION AND OBJECTIVE

Heredity of type 2 diabetes mellitus (T2DM) is associated with greater risk for developing T2DM. Thus, individuals who have a first-degree relative with T2DM (FDRT) provide a natural model to study factors of susceptibility towards development of T2DM, which are poorly understood. Emerging key players in T2DM pathophysiology such as adverse oxidative stress and inflammatory responses could be among possible mechanisms that predispose FDRTs to develop T2DM. Here, we aimed to examine the role of oxidative stress and inflammatory responses as mediators of this excess risk by studying dynamic postprandial responses in FDRTs.

RESEARCH DESIGN AND METHODS

In this open-label case-control study, we recruited normoglycemic men with (n=9) or without (n=9) a family history of T2DM. We assessed plasma glucose, insulin, lipid profile, cytokines and F₂-isoprostanes, expression levels of oxidative and inflammatory genes/proteins in circulating mononuclear cells (MNC), myotubes and adipocytes at baseline (fasting state), and after consumption of a carbohydrate-rich liquid meal or insulin stimulation.

RESULTS

Postprandial glucose and insulin responses were not different between groups. Expression of oxidant transcription factor NRF2 protein (p<0.05 for myotubes) and gene (p_group=0.002, p_time×group=0.016), along with its target genes TXNRD1 (p_group=0.004, p_time×group=0.007), GPX3 (p_group=0.011, p_time×group=0.019) and SOD-1 (p_group=0.046 and p_time×group=0.191) was upregulated in FDRT-derived MNC after meal ingestion or insulin stimulation. Synergistically, expression of target genes of inflammatory transcription factor nuclear factor kappa B such as tumor necrosis factor alpha (p_group=0.001, p_time×group=0.007) was greater in FDRT-derived MNC than in non-FDRT-derived MNC after meal ingestion or insulin stimulation.

CONCLUSIONS

Our findings shed light on how heredity of T2DM confers increased susceptibility to oxidative stress and inflammation. This could provide early insights into the underlying mechanisms and future risk of FDRTs for developing T2DM and its associated complications.

Reduced inflammation and cytokine production in NKLAM deficient mice during Streptococcus pneumoniae infection

Streptococcus pneumoniae is a leading cause of pneumonia and a significant economic burden. Antibiotic-resistant S. pneumoniae has become more prevalent in recent years and many pneumonia cases are caused by S. pneumoniae that is resistant to at least one antibiotic. The ubiquitin ligase natural killer lytic-associated molecule (NKLAM/RNF19b) plays a role in innate immunity and studies using NKLAM-knockout (NKLAM-KO) macrophages have demonstrated that NKLAM positively affects the transcriptional activity of STAT1. Using an inhalation infection model, we found that NKLAM-KO mice had a significantly higher lung bacterial load than WT mice but had less lung inflammation. Coincidently, NKLAM-KO mice had fewer neutrophils and NK cells in their lungs. NKLAM-KO mice also expressed less iNOS in their lungs as well as less MCP-1, MIP1α, TNFα, IL-12, and IFNγ. Both neutrophils and macrophages from NKLAM-KO mice were defective in killing S. pneumoniae as compared to wild type cells (WT). The phosphorylation of STAT1 and STAT3 in NKLAM-KO lungs was lower than in WT lungs at 24 hours post-infection. NKLAM-KO mice were afforded some protection against a lethal dose of S. pneumoniae compared to WT mice. In summary, our novel data demonstrate a role for E3 ubiquitin ligase NKLAM in modulating innate immunity via the positive regulation of inflammatory cytokine expression and bactericidal activity.

Zoledronic acid and alendronate sodium and the implications in orthodontic movement

OBJECTIVE

To evaluate orthodontic tooth movement (OTM) in rats treated with two types of bisphosphonates (BPs), alendronate sodium (A) and zoledronic acid (Z).

DESIGN

In all, 15 male Wistar rats were randomly divided into three groups. Group OTM+A: orthodontic tooth movement and subcutaneous administration of alendronate sodium (2.5 mg/kg); Group OTM+Z: orthodontic tooth movement and subcutaneous administration of zoledronic acid (0.02 mg/kg), and Group OTM: orthodontic tooth movement and subcutaneous injection of saline. The BPs were administered once a day during 25 days before OTM started and during 10 days of OTM. The left upper first molar was moved with a stainless-steel closed coil spring which delivered an initial force of 0.4N. OTM was measured with a digital caliper comparing the moved and the contralateral side. The histomorphometric analysis counted the number of osteoclasts, inflammatory cells, blood vessels and fibroblasts (n/10⁴  m² ) in periodontal ligament (PDL) of the distobuccal root.

RESULTS

A reduction of 58.3% of OTM was found in Group OTM+A and 99.6% in Group OTM+Z, when compared with Group OTM. There was a significant decrease of osteoclasts and inflammatory cells in BP-treated groups. Blood vessels and fibroblastic cells decreased mainly in Group OTM+Z.

CONCLUSION

Alendronate sodium and zoledronic acid have similar effects on the periodontal tissue during orthodontic treatment in rats. Especially, zoledronic acid can affect orthodontic tooth movement.

Liposome encapsulated zoledronate favours M1-like behaviour in murine macrophages cultured with soluble factors from breast cancer cells

Background

Tumour stromal macrophages differentiate to tumour-associated macrophages (TAMs) with characteristics of immunosuppressive M2-type macrophages, having a central role in promoting tumour vascularisation, cancer cell dissemination and in suppressing anti-cancer immune responses. Bisphosphonates (BPs) are a group of drugs commonly used as anti-resorptive agents. Further, nitrogen containing BPs like Zoledronate (ZOL), are known to cause unspecific inflammatory reactions hence the hypothesis that its use could modulate TAMs polarization toward a more inflammatory phenotype.

Methods

We studied the in vitro polarization of J774 murine macrophages upon culture in 4T1 breast cancer cell-conditioned medium (4T1CM) and stimulation with LPS and free and liposome-encapsulated bisphosphonates.

Results

In this system, breast cancer soluble factors reduced the pro-inflammatory activation of macrophages but increased the secretion of matrix metalloproteinases (MMPs). In the presence of 4T1CM, a non-cytotoxic dose of liposome-encapsulated ZOL (ZOL-LIP) enhanced the expression of iNOS and TNF-α, markers of M1 activation, but did not diminish the expression of M2-type markers. In contrast, clodronate treatment either as a free drug (CLO) or liposome-encapsulated (CLO-LIP) decreased the expression of the M1-type markers and was highly cytotoxic to the macrophages.

Conclusions

Breast cancer cells soluble factors modulate macrophages toward M2 activation state. Bisphosphonates may be applied to counteract this modulation. We propose that ZOL-LIP may be suitable for favouring cytotoxic immune responses by TAMs in breast cancer, whereas CLO-LIP may be appropriate for TAM depletion.

Pretreatment of aripiprazole and minocycline, but not haloperidol, suppresses oligodendrocyte damage from interferon-γ-stimulated microglia in co-culture model

Recent imaging studies have indicated that the pathophysiology of schizophrenia is closely related to white matter abnormalities and microglial activation. Additionally, recent clinical trials have suggested that atypical antipsychotics may have brain protective properties and that minocycline, an antibiotic with inhibitory effects on microglial activation, improves symptoms of schizophrenia. We have reported that not only atypical antipsychotics with dopamine D2 receptor (D2R) antagonism but also aripiprazole, a unique antipsychotic drug with D2R partial agonism, inhibit microglial activation in vitro. Thus, atypical antipsychotics may exert a beneficial influence on both microglia and oligodendrocytes, while the underlying mechanisms have not been clarified. Here, we investigated whether antipsychotics suppress oligodendrocyte damage by inhibiting microglial activation utilizing a co-culture model with microglia and oligodendrocytes. Pretreatment of aripiprazole and minocycline suppressed apoptosis of oligodendrocytes in the co-culture model with interferon-γ (IFN-γ)-activated microglia, while haloperidol, a traditional antipsychotic drug, did not. Aripiprazole and minocycline inhibited the production of tumor necrosis factor-alpha (TNF-α) from IFN-γ-activated microglia. Moreover, aripiprazole and minocycline attenuated the phosphorylation of signal transducer and activator of transcription 1 (STAT1) in microglia. Overall, our results suggest that aripiprazole and minocycline may have antipsychotic effects through reducing oligodendrocyte damage caused by microglial activation. These results put forward a novel therapeutic hypothesis in schizophrenia research. Future in vivo studies to confirm the present results should be performed.

Bisphosphonates inhibit phosphorylation of signal transducer and activator of transcription 3 and expression of suppressor of cytokine signaling 3: implications for their effects on innate immune function and osteoclastogenesis

OBJECTIVE

This study tested the effects of bisphosphonates (BPs) on the suppressor of cytokine signaling 3 (SOCS3) protein in macrophages. SOCS3 has been shown to regulate cell differentiation and survival; however, its potential role in mediating the effects of BPs has not been explored.

STUDY DESIGN

The cell viability of murine RAW 267.4 macrophages was assessed after culturing with control medium or media containing increasing concentrations of 2 BPs (ibandronate or clodronate) for 24, 48, and 72 hours. The phosphorylation status of signal transducer and activator of transcription 3 (STAT3) and the expression of SOCS3 protein levels were determined by Western blot analysis.

RESULTS

In control cultures, STAT3 phosphorylation and STAT3 and SOCS3 protein levels increased within 5 minutes after the addition of fresh medium. This increase was inhibited in cultures treated with both BPs. Macrophage cell viability also decreased after BP treatment.

CONCLUSIONS

These data demonstrate that, in addition to their effects on macrophage viability, BPs can decrease STAT3 and SOCS3 expression, which are important modulators of immune responses and bone homeostasis.

Transcriptional control of the TNF gene

The cytokine TNF is a critical mediator of immune and inflammatory responses. The TNF gene is an immediate early gene, rapidly transcribed in a variety of cell types following exposure to a broad range of pathogens and signals of inflammation and stress. Regulation of TNF gene expression at the transcriptional level is cell type- and stimulus-specific, involving the recruitment of distinct sets of transcription factors to a compact and modular promoter region. In this review, we describe our current understanding of the mechanisms through which TNF transcription is specifically activated by a variety of extracellular stimuli in multiple cell types, including T cells, B cells, macrophages, mast cells, dendritic cells, and fibroblasts. We discuss the role of nuclear factor of activated T cells and other transcription factors and coactivators in enhanceosome formation, as well as the contradictory evidence for a role for nuclear factor kappaB as a classical activator of the TNF gene. We describe the impact of evolutionarily conserved cis-regulatory DNA motifs in the TNF locus upon TNF gene transcription, in contrast to the neutral effect of single nucleotide polymorphisms. We also assess the regulatory role of chromatin organization, epigenetic modifications, and long-range chromosomal interactions at the TNF locus.

Atlas of signaling for interpretation of microarray experiments

Microarray-based expression profiling of living systems is a quick and inexpensive method to obtain insights into the nature of various diseases and phenotypes. A typical microarray profile can yield hundreds or even thousands of differentially expressed genes and finding biologically plausible themes or regulatory mechanisms underlying these changes is a non-trivial and daunting task. We describe a novel approach for systems-level interpretation of microarray expression data using a manually constructed “overview” pathway depicting the main cellular signaling channels (Atlas of Signaling). Currently, the developed pathway focuses on signal transduction from surface receptors to transcription factors and further transcriptional regulation of cellular “workhorse” proteins. We show how the constructed Atlas of Signaling in combination with an enrichment analysis algorithm allows quick identification and visualization of the main signaling cascades and cellular processes affected in a gene expression profiling experiment. We validate our approach using several publicly available gene expression datasets.

Tolerance and M2 (alternative) macrophage polarization are related processes orchestrated by p50 nuclear factor kappaB

Cells of the monocyte-macrophage lineage play a central role in the orchestration and resolution of inflammation. Plasticity is a hallmark of mononuclear phagocytes, and in response to environmental signals these cells undergo different forms of polarized activation, the extremes of which are called classic or M1 and alternative or M2. NF-kappaB is a key regulator of inflammation and resolution, and its activation is subject to multiple levels of regulation, including inhibitory, which finely tune macrophage functions. Here we identify the p50 subunit of NF-kappaB as a key regulator of M2-driven inflammatory reactions in vitro and in vivo. p50 NF-kappaB inhibits NF-kappaB-driven, M1-polarizing, IFN-beta production. Accordingly, p50-deficient mice show exacerbated M1-driven inflammation and defective capacity to mount allergy and helminth-driven M2-polarized inflammatory reactions. Thus, NF-kappaB p50 is a key component in the orchestration of M2-driven inflammatory reactions.

Importance of microcracks in etiology of bisphosphonate-related osteonecrosis of the jaw: a possible pathogenetic model of symptomatic and non-symptomatic osteonecrosis of the jaw based on scanning electron microscopy findings

The aim of this study was to evaluate a possible role of microcracks in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (ONJ) and to discuss an etiological model. Bone samples from 35 patients with ONJ were analyzed. Control samples were taken from five patients with osteomyelitis (OM), ten patients with osteoradionecrosis, seven patients with osteoporosis and bisphosphonate medication without signs of ONJ, and six osteoporotic elderly patients. Samples were examined using scanning electron microscopy. In 54% of the bone samples of patients with ONJ, microcracks were seen. Inflammatory and connective tissue reactions within the microcracks were evident in 82% of the cases, indicating that these cracks were not artificial. In contrast, only 29% of samples from patients with oral bisphosphonate medication without ONJ, no sample from patients with OM, none of the osteoradionecrosis group, and only 17% from patients with osteoporosis showed microcracks. Statistically significant differences could be found between the ONJ group and the group after irradiation and the group with OM, respectively. The evidence of microcracks could be a first step in the pathogenesis of bisphosphonate-related ONJ. The accumulation of these microcracks leads to a situation that could be named "non-symptomatic ONJ". Disruptions of the mucosal integrity may then allow bacterial invasion, leading to jawbone infection with exposed bone, fistulas, and pain. This state could be called "symptomatic ONJ". Furthermore, an assumed local immunosuppression as indicated by various studies could explain the severe courses of therapy-resistant ONJ as regularly observed.

Zoledronic acid modulates antitumoral responses of prostate cancer-tumor associated macrophages

Macrophages are considered a key component of the immunosuppressive environment present in solid tumors, where they support tumor growth through the production of pro-angiogenic factors and active suppression of effector immune responses. Zoledronic acid (ZA), an aminobisphosphonate clinically approved for treatment of symptomatic skeletal events, has recently been shown to have immunomodulatory properties that can be exploited in cancer immunotherapy. Here, we utilize an in vitro model of prostate cancer cell-macrophage interaction to dissect the effect of ZA, on the function of prostate cancer tumor-associated macrophages (PC-TAM). We show that prostate cancer cells recruit macrophages, which in turn express a variety of proangiogenic and immunosuppressive mediators. ZA selectively suppressed the expression of MMP-9 by PC-TAM, whereas the expression of other mediators was not limited. PC-TAM treated with ZA, on the other hand, could effectively drive the proliferation of activated Tgammadelta lymphocytes, which lysed bisphosphonate-pulsed prostate cancer cells. Moreover, ZA boosted the production of type-1 cytokines by PC-TAM in response to immunomodulators such as IL-12 and polyI:C, which are known to polarize macrophages towards an anti-tumoral M1 phenotype. Overall, we provide evidence that ZA shifts the balance of PC-TAM from a tumor promoting to a tumor-eliminating phenotype and also suggest a potential use of this pharmacological agent as an immunotherapeutic adjuvant.

Natural isoprenoids are able to reduce inflammation in a mouse model of mevalonate kinase deficiency

Mevalonate kinase deficiency (MKD) is a rare disorder characterized by recurrent inflammatory episodes and, in most severe cases, by psychomotor delay. Defective synthesis of isoprenoids has been associated with the inflammatory phenotype in these patients, but the molecular mechanisms involved are still poorly understood, and, so far, no specific therapy is available for this disorder. Drugs like aminobisphosphonates, which inhibit the mevalonate pathway causing a relative defect in isoprenoids synthesis, have been also associated to an inflammatory phenotype. Recent data asserted that cell inflammation could be reversed by the addition of some isoprenoids, such as geranylgeraniol and farnesyl pyrophosphate. In this study, a mouse model for typical MKD inflammatory episode was obtained treating BALB/c mice with aminobisphosphonate alendronate and bacterial muramyldipeptide. The effect of exogenous isoprenoids -- geraniol, farnesol, and geranylgeraniol -- was therefore evaluated in this model. All these compounds were effective in preventing the inflammation induced by alendronate-muramyldipeptide, suggesting a possible role for these compounds in the treatment of MKD in humans.

Janus kinase 3 inhibitor WHI-P154 in macrophages activated by bacterial endotoxin: differential effects on the expression of iNOS, COX-2 and TNF-alpha

Bacterial endotoxin is a potent inducer of inflammatory response, including the induction of inducible nitric oxide synthase (iNOS) expression and nitric oxide (NO) production, and the expression of cyclo-oxygenase (COX)-2 and tumor necrosis factor (TNF)-alpha in inflammatory cells. In the present study, we investigated the effects of pharmacological inhibition of Janus kinase (JAK) 3 on the production of these proinflammatory molecules in macrophages exposed to bacterial endotoxin (lipopolysaccharide; LPS). JAK3 inhibitors WHI-P154 (4-(3'-bromo-4'-hydroxylphenyl)-amino-6,7-dimethoxyquinazoline) and its derivative WHI-P131 inhibited LPS-induced iNOS expression and NO production in a dose-dependent manner. WHI-P154 inhibited the activation of signal transducer and activator of transcription (STAT) 1 and the expression of iNOS mRNA but it had no effect on iNOS mRNA decay when determined by actinomycin D assay. The JAK3 inhibitor had no effect on COX-2 expression, and TNF-alpha production was slightly inhibited only at higher drug concentrations (30 microM). In addition, WHI-P154 inhibited iNOS expression and NO production also in human epithelial cells. Our results suggest that JAK3 inhibition modulates human and murine iNOS expression and NO production in response to inflammatory stimuli.

Effects of the bisphosphonate ibandronate on hyperalgesia, substance P, and cytokine levels in a rat model of persistent inflammatory pain

The anti-inflammatory and analgesic properties of different bisphosphonates have been demonstrated in both animal and human studies. Ibandronate is a third-generation bisphosphonate effective in managing different types of bone pain. In this study we investigated its effects in a standard pre-clinical model of inflammatory pain. We evaluated the effects of a single injection of different doses (0.5, 1.0, and 2.0 mg/kg i.p.) of ibandronate on inflammatory oedema and cutaneous hyperalgesia produced by the intraplantar injection of complete Freund's adjuvant (CFA) in the rat hind-paw. In addition, we measured the effects of this drug (1.0 mg/kg i.p.) on hind-paw levels of different pro-inflammatory mediators (PGE-2, SP, TNF-alpha, and IL-1beta). We also measured the levels of SP protein and of its mRNA in the ipsilateral dorsal root ganglia (DRG). Ibandronate proved able to reduce the inflammatory oedema, the hyperalgesia to mechanical stimulation, and the levels of SP in the inflamed tissue as measured 3 and 7 days following CFA-injection. This drug significantly reduced the levels of TNF-alpha and IL-1beta only on day 7. On the other hand, the levels of PGE-2 in the inflamed hind-paw were unaffected by the administration of this bisphosphonate. Finally, ibandronate blocked the overexpression of SP mRNA in DRG induced by CFA-injection in the hind-paw. These data help to complete the pharmacodynamic profile of ibandronate, while also suggesting an involvement of several inflammatory mediators, with special reference to substance P, in the analgesic action of this bisphosphonate.

Pamidronate infusion in patients with systemic sclerosis results in changes in blood mononuclear cell cytokine profiles

A single infusion of pamidronate was given to patients with systemic sclerosis (scleroderma, SSc) to assess effects on cytokine production by peripheral blood mononuclear cells (PBMC) and lymphocyte subsets. Eighteen patients with SSc received a single intravenous dose of 60 mg of pamidronate and were followed for 6 months. Assessment of cytokine production [interferon (IFN)-gamma, interleukin (IL)-10, transforming growth factor (TGF)-beta1, tumour necrosis factor (TNF)-alpha and IL-4] by PBMC and lymphocyte subsets by flow cytometry was carried out before and after the pamidronate infusion. Unstimulated PBMC produced increased amounts of IFN-gamma and TNF-alpha and reduced levels of TGF-beta1 for up to 24 weeks after the infusion. gammadelta T cells from patients with SSc were activated in vitro and produced increased IFN-gamma. The effects of pamidronate on modulation of cytokine profiles in patients with SSc may merit future study.

Histidine decarboxylase-stimulating and inflammatory effects of alendronate in mice: Involvement of mevalonate pathway, TNFα, macrophages, and T-cells

Nitrogen-containing bisphosphonates (NBPs) are powerful anti-bone-resorptive drugs, but they frequently induce various inflammatory side effects. Recent clinical applications have disclosed an unexpected new side effect, jaw-bone necrosis and exposure. In vitro studies suggest that the inflammatory effects of NBPs are due to Vgamma2Vdelta2 T-cells, stimulated directly and/or indirectly [the latter via isopentenylpyrophosphate (IPP) in the mevalonate pathway]. Rats and mice, however, lack Vgamma2Vdelta2 T-cells, yet NBPs still induce necrotic and inflammatory reactions. In mice, NBPs induce IL-1-dependent inflammatory reactions, such as inductions of histidine decarboxylase (HDC, the histamine-forming enzyme) in the liver, lung, spleen, and bone marrow, an increase in granulocytic cells in the peritoneal cavity, pleural exudation, and splenomegaly. Here, we examined the involvement of IPP, TNF, macrophages, and T-cells in the inflammatory actions of alendronate (a typical NBP) in mice. Various statins (mevalonate-synthesis inhibitors) suppressed the alendronate-induced HDC inductions, while mevalonate itself augmented such inductions. IPP injection also induced HDC. Like IL-1-deficient mice, TNF-deficient mice were resistant to alendronate-stimulated HDC induction. Alendronate-stimulated HDC inductions were significantly weaker in macrophage-depleted mice and in nude mice than in control mice. Similar, though generally less clear-cut, results were obtained when other alendronate-induced inflammatory reactions were examined. These results suggest that (i) inhibition of the mevalonate pathway causes and/or modifies at least some inflammatory actions of alendronate in mice, (ii) in addition to IL-1, TNF is also involved in the inflammatory actions of alendronate, and (iii) alendronate may act on a variety of cells, including macrophages and T-cells.

Conserved nontypeable Haemophilus influenzae-derived TLR2-binding lipopeptides synergize with IFN-beta to increase cytokine production by resident murine and human alveolar macrophages

Nontypeable Haemophilus influenzae (NTHi) is strongly associated with exacerbations of chronic obstructive pulmonary disease, which often coincide with viral respiratory infections. TLR2 contributes importantly to innate immunity to NTHi, but whether this pathway is affected by simultaneous antiviral responses is unknown. To analyze potential interactions, resident murine and human alveolar macrophages (AMphi) were exposed, in the presence or absence of the appropriate rIFN-beta, to synthetic lipopeptides corresponding to the triacylated N-terminal fragments of three outer membrane proteins (OMP) (PCP, P4, and P6) that are highly conserved among different NTHi strains. Synthetic OMP elicited strong release of IL-6, the principal inducer of airway mucin genes, and induced CCL5 and CXCL10 from murine AMphi only when IFN-beta was also present. Surprisingly, combined stimulation by OMPs and IFN-beta also markedly enhanced TNF-alpha release by murine AMphi. Stimulation with PCP plus IFN-beta induced IFN-regulatory factor 1 expression and sustained STAT1 activation, but did not alter the activation of MAPKs or NF-kappaB. AMphi derived from STAT1-deficient mice did not demonstrate increased production of TNF-alpha in response to PCP plus IFN-beta. Analysis of wild-type and STAT1-deficient AMphi using real-time PCR showed that increased TNF-alpha production depended on transcriptional up-regulation, but not on mRNA stabilization. The synergistic effect of synthetic OMP and IFN-beta was conserved between murine AMphi and human AMphi for IL-6, but not for TNF-alpha. Thus, IFN-beta, which is produced by virally infected respiratory epithelial cells, converts normally innocuous NTHi OMP into potent inflammatory stimulants, but does so via different mechanisms in mice and humans.

A Regulatory Effect of the Balance between TNF-α and IL-6 in the Granulomatous and Inflammatory Response toRhodococcus aurantiacusInfection in Mice

After i.v. inoculation with Rhodococcus aurantiacus, wild-type (WT) mice develop nonnecrotic, epithelioid granulomas. Because a high level of TNF-alpha is observed during the initial phase postinfection, we examined the extent to which TNF-alpha contributes to granulomatous inflammation using TNF-alpha gene-deficient (TNF-alpha(-/-)) mice. Despite a lack of R. aurantiacus proliferation, TNF-alpha(-/-) mice displayed high mortality rates within 5 days postinfection, as well as a high level of IL-6 in their spleens. Histological examination showed an absence of granuloma formation in TNF-alpha(-/-) mice. Pretreatment of TNF-alpha(-/-) mice with rTNF-alpha failed to restore this granuloma formation but accelerated bacterial removal and cellular recruitment. This rTNF-alpha administration also attenuated IL-6 production, resulting in increased survival rates of TNF-alpha(-/-) mice. Heat-killed R. aurantiacus induced in vitro enhanced mRNA expression and production of IL-6 in macrophages and DCs from TNF-alpha(-/-) mice when compared with WT controls, and treatment of TNF-alpha(-/-) mouse cells with rTNF-alpha decreased the IL-6 secretion. Moreover, anti-TNF-alpha or anti-IL-6 treatment increased IL-6 or TNF-alpha production by WT mouse cells, respectively. These data suggest that the production of TNF-alpha and IL-6 can be negatively regulated by each other. Administration of rIFN-gamma to TNF-alpha(-/-) mice caused immature granulomas in livers, and treatment with both rTNF-alpha and rIFN-gamma led to the formation of mature granulomas. Overall, TNF-alpha appears crucial for bacterial clearance, cellular recruitment, and granuloma formation. The balance between TNF-alpha and IL-6 during the early phase of infection controls the development of the inflammatory response to R. aurantiacus infection.

The effect of bisphosphonates on gene expression: GAPDH as a housekeeping or a new target gene?

BACKGROUND

RT-PCR has been widely used for the analysis of gene expression in many systems, including tumor samples. GAPDH (Glyceraldehyde-3-phosphate dehydrogenase) has been frequently considered as a constitutive housekeeping gene and used to normalize changes in specific gene expression. However, GAPDH has been shown to be up-regulated in many cancers and down-regulated by chemotherapic drugs. Bisphosphonates, potent inhibitors of bone resorption, have recently shown a direct and indirect antitumor effect in vitro and in animal models. They exert their effects mainly by inhibiting the mevalonate pathway but also by modulating the expression of many genes not only in osteoclasts but also in cancer cells.

METHODS

We evaluated GAPDH gene expression by real time RT PCR in breast (MCF-7 and T47D) and prostate (PC3 and DU-145) cancer cell lines treated with amino and non-amino bisphosphonates.

RESULTS

Our results showed that amino-bisphosphonates significantly decrease in a dose-dependent manner the expression of GAPDH gene.

CONCLUSION

Therefore, GAPDH is inaccurate to normalize mRNA levels in studies investigating the effect of bisphosphonates on gene expression and it should be avoided. On the other hand, this gene could be considered a potential target to observe the effects of bisphosphonates on cancer cells.

Murine serum cytokines throughout the estrous cycle, pregnancy and post partum period

Cytokines are pleiotropic glycoproteins participating in many aspects of mammalian reproductive physiology. Although murine models have been established to study normal and pathological pregnancy, the small volume of retrievable sample has hampered investigations into the role of cytokines in these processes. These problems were overcome by using fluid-phase multiplex immunoassays to monitor the serum profiles of 18 cytokines in single animals throughout normal murine reproduction: estrus, diestrus, post coitum, preimplantation, implantation, mid-pregnancy, late pregnancy and post partum. Most cytokines were detectable throughout all stages studied. Modest changes in profile were associated with estrous cyclicity and early pregnancy while virtually all cytokine levels increased markedly in mid- to late pregnancy and either fell slightly or levelled off post partum. The functional interrelationships between the various cytokines and the hormonal milieu are discussed with respect to gestational stage. Although certain profiles supported the 'conventional' Th1:Th2 cytokine paradigm of pregnancy, many of the changes recorded were orchestrated around IL-12 (p40) and (p70). The present findings suggest that the traditional cytokine dichotomy poorly describes complex immunological processes like pregnancy.

Mutual augmentation of the induction of the histamine-forming enzyme, histidine decarboxylase, between alendronate and immuno-stimulants (IL-1, TNF, and LPS), and its prevention by clodronate

Nitrogen-containing bisphosphonates (N-BPs), powerful anti-bone-resorptive drugs, have inflammatory side effects, while histamine is not only an inflammatory mediator, but also an immuno-modifier. In murine models, a single intraperitoneal injection of an N-BP induces various inflammatory reactions, including the induction of the histamine-forming enzyme histidine decarboxylase (HDC) in tissues important in immune responses (such as liver, lungs, spleen, and bone marrow). Lipopolysaccharide (LPS) and the proinflammatory cytokines IL-1 and TNF are also capable of inducing HDC. We reported previously that in mice, (i) the inflammatory actions of N-BPs depend on IL-1, (ii) N-BP pretreatment augments both LPS-stimulated IL-1 production and HDC induction, and (iii) the co-administration of clodronate (a non-N-BP) with an N-BP inhibits the latter's inflammatory actions (including HDC induction). Here, we add the new findings that (a) pretreatment with alendronate (a typical N-BP) augments both IL-1- and TNF-induced HDC elevations, (b) LPS pretreatment augments the alendronate-induced HDC elevation, (c) co-administration of clodronate with alendronate abolishes these augmentations, (d) alendronate does not induce HDC in IL-1-deficient mice even if they are pretreated with LPS, and (e) alendronate increases IL-1beta in all tissues tested, but not in the serum. These results suggest that (1) there are mutual augmentations between alendronate and immuno-stimulants (IL-1, TNF, and LPS) in HDC induction, (2) tissue IL-1beta is important in alendronate-stimulated HDC induction, and (3) combination use of clodronate may have the potential to reduce the inflammatory effects of alendronate (we previously found that clodronate, conveniently, does not inhibit the anti-bone-resorptive activity of alendronate).