Interleukin-11

Melatonin alleviates oral epithelial cell inflammation via Keap1/Nrf2 signaling

BACKGROUND

Oral mucosal diseases manifest primarily as inflammatory conditions. These diseases affect approximately half a billion people worldwide.

OBJECTIVE

Novel and effective strategies for treating inflammatory diseases of the oral mucosa have great potential for improving patient outcomes, and warrant study.

METHODS

The impact of melatonin on inflammation was investigated using RAW264.7 macrophages and HOEC and HSC-3 oral epithelial cells.

RESULTS

Melatonin decreased macrophage-induced inflammation by acting through the melatonin receptor MTNR1A. Additionally, melatonin mitigated macrophage-induced inflammation in oral epithelial cells. Importantly, the results demonstrated that the effects of melatonin on oral epithelial inflammation were mediated through the KEAP1/Nrf2 signaling pathway.

CONCLUSION

These findings will contribute to the development of innovative therapies for inflammatory conditions affecting the oral epithelium.

Radiofrequency Currents Modulate Inflammatory Processes in Keratinocytes

Keratinocytes play an essential role in the inflammatory phase of wound regeneration. In addition to migrating and proliferating for tissue regeneration, they produce a large amount of cytokines that modulate the inflammatory process. Previous studies have shown that subthermal treatment with radiofrequency (RF) currents used in capacitive resistive electric transfer (CRET) therapy promotes the proliferation of HaCat keratinocytes and modulates their cytokine production. Although physical therapies have been shown to have anti-inflammatory effects in a variety of experimental models and in patients, knowledge of the biological basis of these effects is still limited. The aim of this study was to investigate the effect of CRET on keratinocyte proliferation, cytokine production (IL-8, MCP-1, RANTES, IL-6, IL-11), TNF-α secretion, and the expression of MMP9, MMP1, NF-κB, ERK1/2, and EGFR. Human keratinocytes (HaCat) were treated with an intermittent 448 kHz electric current (CRET signal) in subthermal conditions and for different periods of time. Cell proliferation was analyzed by XTT assay, cytokine and TNF-α production by ELISA, NF-κB expression and activation by immunofluorescence, and MMP9, MMP1, ERK1/2, and EGF receptor expression and activation by immunoblot. Compared to a control, CRET increases keratinocyte proliferation, increases the transient release of MCP-1, TNF-α, and IL-6 while decreasing IL-8. In addition, it modifies the expression of MMPs and activates EGFR, NF-κB, and ERK1/2 proteins. Our results indicate that CRET reasonably modifies cytokine production through the EGF receptor and the ERK1/2/NF-κB pathway, ultimately modulating the inflammatory response of human keratinocytes.

Traumatic inflammatory response: pathophysiological role and clinical value of cytokines

Severe trauma is an intractable problem in healthcare. Patients have a widespread immune system response that is complex and vital to survival. Excessive inflammatory response is the main cause of poor prognosis and poor therapeutic effect of medications in trauma patients. Cytokines are signaling proteins that play critical roles in the body's response to injuries, which could amplify or suppress immune responses. Studies have demonstrated that cytokines are closely related to the severity of injuries and prognosis of trauma patients and help present cytokine-based diagnosis and treatment plans for trauma patients. In this review, we introduce the pathophysiological mechanisms of a traumatic inflammatory response and the role of cytokines in trauma patients. Furthermore, we discuss the potential of cytokine-based diagnosis and therapy for post-traumatic inflammatory response, although further clarification to elucidate the underlying mechanisms of cytokines following trauma is warranted.

Roles of IL-11 in the regulation of bone metabolism

Bone metabolism is the basis for maintaining the normal physiological state of bone, and imbalance of bone metabolism can lead to a series of metabolic bone diseases. As a member of the IL-6 family, IL-11 acts primarily through the classical signaling pathway IL-11/Receptors, IL-11 (IL-11R)/Glycoprotein 130 (gp130). The regulatory role of IL-11 in bone metabolism has been found earlier, but mainly focuses on the effects on osteogenesis and osteoclasis. In recent years, more studies have focused on IL-11's roles and related mechanisms in different bone metabolism activities. IL-11 regulates osteoblasts, osteoclasts, BM stromal cells, adipose tissue-derived mesenchymal stem cells, and chondrocytes. It's involved in bone homeostasis, including osteogenesis, osteolysis, bone marrow (BM) hematopoiesis, BM adipogenesis, and bone metastasis. This review exams IL-11's role in pathology and bone tissue, the cytokines and pathways that regulate IL-11 expression, and the feedback regulations of these pathways.

Interleukin-11 in Pathologies of the Nervous System

The study of the role of cytokines in various pathological conditions of the body is a topical area in modern biomedicine. Understanding the physiological roles played by cytokines will aid in finding applications for them as pharmacological agents in clinical practice. Interleukin 11 (IL-11) was discovered in 1990 in fibrocyte-like bone marrow stromal cells, but there has been increased interest in this cytokine in recent years. IL-11 has been shown to correct inflammatory pathways in the epithelial tissues of the respiratory system, where the main events occur during SARS-CoV-2 infection. Further research in this direction will probably support the use of this cytokine in clinical practice. The cytokine plays a significant role in the central nervous system; local expression by nerve cells has been shown. Studies show the involvement of IL-11 in the mechanisms of development of a number of pathologies of the nervous system, and therefore it seems relevant to generalize and analyze the experimental data obtained in this direction. This review summarizes information that shows the involvement of IL-11 in the mechanisms of development of brain pathologies. In the near future this cytokine will likely find clinical application for the correction of mechanisms that are involved in the formation of pathological conditions of the nervous system.

Focusing on OB-OC-MΦ Axis and miR-23a to Explore the Pathogenesis and Treatment Strategy of Osteoporosis

Osteoporosis is a bone metabolic disorder characterized by decreased bone density and deteriorated microstructure, which increases the risk of fractures. The imbalance between bone formation and bone resorption results in the occurrence and progression of osteoporosis. Osteoblast-mediated bone formation, osteoclast-mediated bone resorption and macrophage-regulated inflammatory response play a central role in the process of bone remodeling, which together maintain the balance of the osteoblast-osteoclast-macrophage (OB-OC-MΦ) axis under physiological conditions. Bone formation and bone resorption disorders caused by the imbalance of OB-OC-MΦ axis contribute to osteoporosis. Many microRNAs are involved in the regulation of OB-OC-MΦ axis homeostasis, with microRNA-23a (miR-23a) being particularly crucial. MiR-23a is highly expressed in the pathological process of osteoporosis, which eventually leads to the occurrence and further progression of osteoporosis by inhibiting osteogenesis, promoting bone resorption and inflammatory polarization of macrophages. This review focuses on the role and mechanism of miR-23a in regulating the OB-OC-MΦ axis to provide new clinical strategies for the prevention and treatment of osteoporosis.

Cytokines in Liver Transplantation

Cytokines, soluble mediators of the immune system, play a critical role in the pathogenesis of autoimmune, allergic and infectious diseases. They are also implicated in the initiation and development of allograft rejection. During recent years, there have been considerable advances in generating novel anti-cytokine agents with promoted efficacy and safety, which could be administrated for managing dysregulated cytokine secretion; besides, gene therapy for overexpression of immunomodulatory cytokines has shown substantial improvements. Liver transplantation has been established as a life-saving treatment for end-stage hepatic diseases but the growing number of recipients urge for improved post-transplant care including tolerance induction, infection control and resolving immunosuppressant drugs adverse effects. Cytokines with a wide range of proinflammatory and regulatory properties might be considered as potential therapeutic targets for selective suppression or enhancement of the immune responses in recipients. In the present review, we aimed to summarize the positive and negative effects of cytokines on liver allograft in addition to their prognostic and therapeutic values.

β-Arrestin 1 in Thyrotropin Receptor Signaling in Bone: Studies in Osteoblast-Like Cells

A direct action of thyrotropin (TSH, thyroid-stimulating hormone) on bone precursors in humans is controversial. Studies in rodent models have provided conflicting findings. We used cells derived from a moderately differentiated osteosarcoma stably overexpressing human TSH receptors (TSHRs) as a model of osteoblast precursors (U2OS-TSHR cells) to investigate TSHR-mediated effects in bone differentiation in human cells. We review our findings that (1) TSHR couples to several different G proteins to induce upregulation of genes associated with osteoblast activity-interleukin 11 (IL-11), osteopontin (OPN), and alkaline phosphatase (ALPL) and that the kinetics of the induction and the G protein-mediated signaling pathways involved were different for these genes; (2) TSH can stimulate β-arrestin-mediated signal transduction and that β-arrestin 1 in part mediates TSH-induced pre-osteoblast differentiation; and (3) TSHR/insulin-like growth factor 1 (IGF1) receptor (IGF1R) synergistically increased OPN secretion by TSH and IGF1 and that this crosstalk was mediated by physical association of these receptors in a signaling complex that uses β-arrestin 1 as a scaffold. These findings were complemented using a novel β-arrestin 1-biased agonist of TSHR. We conclude that TSHR can signal via several transduction pathways leading to differentiation of this model system of human pre-osteoblast cells and, therefore, that TSH can directly regulate these bone cells.

Optimal attenuation of experimental autoimmune encephalomyelitis by intravenous immunoglobulin requires an intact interleukin-11 receptor

Background

Intravenous immunoglobulin (IVIg) has been used to treat a variety of autoimmune disorders including multiple sclerosis (MS); however its mechanism of action remains elusive. Recent work has shown that interleukin-11 (IL-11) mRNAs are upregulated by IVIg in MS patient T cells. Both IVIg and IL-11 have been shown to ameliorate experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The objective of this study was to determine whether the protective effects of IVIg in EAE occur through an IL-11 and IL-11 receptor (IL-11R)-dependent mechanism.

Methods

We measured IL-11 in the circulation of mice and IL-11 mRNA expression in various organs after IVIg treatment. We then followed with EAE studies to test the efficacy of IVIg in wild-type (WT) mice and in mice deficient for the IL-11 receptor (IL-11Rα^−/−). Furthermore, we evaluated myelin-specific Th1 and Th17 responses and assessed spinal cord inflammation and demyelination in WT and IL-11Rα^−/− mice, with and without IVIg treatment. We also examined the direct effects of mouse recombinant IL-11 on the production of IL-17 by lymph node mononuclear cells.

Results

IVIg treatment induced a dramatic surge (>1000-fold increase) in the levels of IL-11 in the circulation and a prominent increase of IL-11 mRNA expression in the liver. Furthermore, we found that IL-11Rα^−/− mice, unlike WT mice, although initially protected, were resistant to full protection by IVIg during EAE and developed disease with a similar incidence and severity as control-treated IL-11Rα^−/− mice, despite initially showing protection. We observed that Th17 cytokine production by myelin-reactive T cells in the draining lymph nodes was unaffected by IVIg in IL-11Rα^−/− mice, yet was downregulated in WT mice. Finally, IL-11 was shown to directly inhibit IL-17 production of lymph node cells in culture.

Conclusion

These results implicate IL-11 as an important immune effector of IVIg in the prevention of Th17-mediated autoimmune inflammation during EAE.

IL-11 produced by breast cancer cells augments osteoclastogenesis by sustaining the pool of osteoclast progenitor cells

BACKGROUND

Interleukin (IL)-11, a cytokine produced by breast cancer, has been implicated in breast cancer-induced osteolysis (bone destruction) but the mechanism(s) of action remain controversial. Some studies show that IL-11 is able to promote osteoclast formation independent of the receptor activator of NF-κB ligand (RANKL), while others demonstrate IL-11 can induce osteoclast formation by inducing osteoblasts to secrete RANKL. This work aims to further investigate the role of IL-11 in metastasis-induced osteolysis by addressing a new hypothesis that IL-11 exerts effects on osteoclast progenitor cells.

METHODS

To address the precise role of breast cancer-derived IL-11 in osteoclastogenesis, we determined the effect of breast cancer conditioned media on osteoclast progenitor cells with or without an IL-11 neutralizing antibody. We next investigated whether recombinant IL-11 exerts effects on osteoclast progenitor cells and survival of mature osteoclasts. Finally, we examined the ability of IL-11 to mediate osteoclast formation in tissue culture dishes and on bone slices in the absence of RANKL, with suboptimal levels of RANKL, or from RANKL-pretreated murine bone marrow macrophages (BMMs).

RESULTS

We found that freshly isolated murine bone marrow cells cultured in the presence of breast cancer conditioned media for 6 days gave rise to a population of cells which were able to form osteoclasts upon treatment with RANKL and M-CSF. Moreover, a neutralizing anti-IL-11 antibody significantly inhibited the ability of breast cancer conditioned media to promote the development and/or survival of osteoclast progenitor cells. Similarly, recombinant IL-11 was able to sustain a population of osteoclast progenitor cells. However, IL-11 was unable to exert any effect on osteoclast survival, induce osteoclastogenesis independent of RANKL, or promote osteoclastogenesis in suboptimal RANKL conditions.

CONCLUSIONS

Our data indicate that a) IL-11 plays an important role in osteoclastogenesis by stimulating the development and/or survival of osteoclast progenitor cells and b) breast cancer may promote osteolysis in part by increasing the pool of osteoclast progenitor cells via tumor cell-derived IL-11. However, given the heterogeneous nature of the bone marrow cells, the precise mechanism by which IL-11 treatment gives rise to a population of osteoclast progenitor cells warrants further investigation.

Association of Interleukin-11 with Mortality in Patients with Spontaneous Basal Ganglia Haemorrhage

This study evaluated interleukin (IL)-11 as an independent prognostic marker of mortality following intracerebral haemorrhage (ICH). Plasma IL-11 levels in patients with ICH were significantly higher than in healthy controls. Multivariate analysis indicated that plasma IL-11 level was an independent predictor for mortality within 1 week of ICH onset and was positively associated with haematoma volume. Receiver operating characteristic curve analysis identified that a baseline plasma IL-11 level > 20.9 pg/ml predicted mortality within 1 week of ICH onset with 81.2% sensitivity and 74.1% specificity. The area under the curve for IL-11 level was significantly smaller than that for the Glasgow Coma Scale score, but similar to that for haematoma volume. IL-11 did not, however, significantly improve the predictive value of the Glasgow Coma Scale or haematoma volume. Thus, IL-11 may be considered as a new independent prognostic marker of mortality and an additional valuable tool for risk stratification and decision-making in the acute phase of ICH.

Prostaglandin E2receptor subtype EP2- and EP4-regulated gene expression profiling in human ciliary smooth muscle cells

Prostanoids are an important class of intraocular pressure (IOP)-lowering antiglaucoma agents that act primarily via increased uveo-scleral aqueous humor outflow through the ciliary body. We have developed two novel PGE2analogs that are specific agonists for the PGE2receptor subtypes EP2 and EP4, respectively. To identify gene regulatory networks and key players that mediate the physiological effects observed in vivo, we performed genomewide expression studies using human ciliary smooth muscle cells. Quantitative real-time RT-PCR confirmed a largely overlapping gene expression profile subsequent to EP2 and EP4 agonist treatment, with 65 significantly regulated genes identified overall, 5 being specific for the EP2 agonist and 6 specific for the EP4 agonist. We found predicted functional cAMP-response elements in promoter regions of a large fraction of the predominantly upregulated genes, which suggests that the cAMP signaling pathway is the most important intracellular signaling pathway for these agonists in these cells. Several target genes were identified that, as part of complex regulatory networks, are implicated in tissue remodeling processes and osmoregulation (e.g., AREG, LOXL3, BMP2, AQP3) and thus may help elucidate the mechanism of action of these IOP-lowering drugs involving the uveo-scleral outflow path.

Th1- and Th2-type cytokines in plasma after major trauma

BACKGROUND

Major trauma induces a dysregulation of immune response supported in parts by lymphocyte dysfunction. Controversial data about a shift within the T-helper cell subsets Th1/Th2 are reported.

METHODS

To prove whether Th1/Th2-type cytokine plasma levels reflect the postulated Th2 shift after trauma, we investigated in a retrospective study 195 severely injured patients (47 women, 148 men; mean age 39.7 +/- 15.8 years; Injury Severity Score 32.0 +/- 11.3 points; overall 1,887 samples) during their ICU stay posttrauma. Mortality rate was 19%. Th1-type cytokines interleukin 2 (IL-2), interferon gamma, IL-12 (p70), and IL-18 and Th2-type cytokines IL-4, IL-10, and IL-11 were determined using the enzyme-linked immunosorbant assay technique in patients and in healthy controls.

RESULTS

IL-2 and interferon gamma were seldom detectable. All other mediators were significantly increased matched to controls (p < 0.05). All cytokines were elevated most prominent during weeks 1 and 2 posttrauma and declined thereafter. A trend toward lower levels in nonsurvivors was seen for both groups of cytokines. However, significant differences were only seen for Injury Severity Score, age, white blood cells, and C-reactive protein. All mediators correlated positively with each other (p < 0.01), a Th2-type shift was not observed. Two groups of patients were identified: one group with generally high plasma levels of all cytokines investigated and a second group of nonresponders who presented with low or diminished plasma levels in which most nonsurvivors were found.

CONCLUSION

We conclude that in plasma no Th1/Th2 shift can be observed after major trauma.

Interleukin-11 attenuates ifosfamide-induced hemorrhagic cystitis

OBJECTIVE

To investigate the possible protective effect of recombinant human interleukin-11 (rhIL-11) against ifosfamide (IFS)-induced hemorrhagic cystitis (HC).

MATERIALS AND METHODS

Male Swiss mice (20-30g) were pretreated with rhIL-11 (25-625 mg, subcutaneously.) 30 min before intraperitoneal injection of IFS (400 mg/kg) or with saline (control group). Twelve hours later, HC was evaluated by bladder wet weight (BWW) to quantify edema, Evans blue extravasation (EBE) to measure vascular permeability, and macroscopic and microscopic analysis. All bladders were assessed by histopathological analysis.

RESULTS

rhIL-11 (at 125 and 625 mg) attenuated the IFS- induced increase of BWW (37.48% and 45.44%, respectively, p < 0.05) and EBE (62.35% and 56.47%, respectively, p < 0.05). IFS- induced macroscopic edema and hemorrhage and microscopic alterations, were also prevented by rhIL-11 at 625 microg. (p < 0.05).

CONCLUSION

Our results demonstrate a protective effect of rhIL-11 on experimental IFS- induced HC, not previously reported.

T cells from patients with polycythemia vera elaborate growth factors which contribute to endogenous erythroid and megakaryocyte colony formation

In the present study, we report that media conditioned by polycythemia vera (PV) CD3+ cells promote BFU-E and CFU-Mk colony formation by both cord blood and PV peripheral blood CD34+ cells in the absence of exogenous cytokines and promoting megakaryocyte proplatelet formation. CD3+ cells constitutively produce elevated levels of IL-11, while stimulation with the addition of phytohemagglutinin (PHA) increased GM-CSF levels in most of the patients with PV. Anti-IL-11-neutralizing antibody partially inhibited the formation of BFU-E and CFU-Mk colonies promoted by PV CD3+ cell-conditioned media. Although IL-11 is not produced by normal T cells, real-time PCR and flow cytometric analysis showed that IL-11 was upregulated in the CD3+ cells of most PV patients as compared to normal CD3+ cells. In addition, a greater percentage of BFU-E colonies formed by PV CD34+ cells in the presence of PV CD3+ cell-conditioned media alone were JAK2V617F-positive as compared with that induced by EPO. We conclude that dysregulated production of soluble growth factor(s), including IL-11 and GM-CSF by PV T cells, contributes to the in vitro formation of erythroid colonies in the absence of exogenous cytokines by PV CD34+ cells and likely plays a role in sustaining hematopoiesis in PV.

Changes in Expression of Interleukin-6 Receptors in Granulosa Cells During Follicular Atresia in Pig Ovaries

More than 99% of follicles undergo a degenerative process known as "atresia" in mammalian ovaries, and only a few follicles ovulate during follicular growth and development. Follicular selection predominantly depends on granulosa cell apoptosis. To reveal the molecular mechanisms of selective follicular atresia, we examined the changes in the levels of interleukin-6 (IL-6) receptors expressed in the granulosa cells of pig ovaries. The levels of IL-6 receptor (IL-6R)-alpha mRNA and protein in granulosa cells were quantified by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. IL-6R alpha mRNA and protein were highly expressed in the granulosa cells of progressed atretic follicles. Enzyme-linked immunosorbent assay showed that the expression of IL-6 soluble receptor (IL-6sR) protein in follicular fluid decreased during atresia. Moreover, we isolated porcine cDNA encoding an IL-6 signal transducer, gp130. Porcine gp130 (2,754 bp and 917 amino acids) was identified from a cDNA library prepared using follicular granulosa cells of pig ovaries. Porcine gp130 was highly homologous with human and murine gp130. RT-PCR analysis revealed that the level of gp130 mRNA also decreased during atresia. We presume that IL-6sR and gp130, but not IL-6R alpha, play important roles in regulation of granulosa cell survival.

Leukaemia inhibitory factor and interleukin 11 levels in uterine flushings of infertile patients with endometriosis

BACKGROUND

Exact aetiology of infertility in stage I/II endometriosis patients is not known. Interleukin 11 (IL-11) and leukaemia-inhibitory factor (LIF) are factors associated with implantation window in human eutopic endometrium. We decided to test whether there is an altered secretion of these factors, which could explain receptivity defect in patients with minimal endometriosis.

METHODS

Uterine flushing and endometrial samples were collected 7-9 days after ovulation (implantation window) from infertile patients with stage I/II endometriosis (n = 14) and fertile, endometriosis-free controls (n = 21). IL-11 and LIF were assessed in uterine flushings in eutopic endometria in all patients by enzyme-linked immunosorbent assay (ELISA). In eutopic endometrium, semiquantitative RT-PCR was performed for LIF and IL-11 mRNA expressions.

RESULTS

No statistically significant differences were found in uterine flushing in women with and without endometriosis with regard to IL-11 levels (0.0 pg/ml versus 0.0 pg/ml) and LIF (25.53 pg/ml versus 36.26 pg/ml). These results were confirmed by the results of RT-PCR, where there were also no differences between studied groups.

CONCLUSIONS

There is no receptivity defect with regard to LIF and IL-11 secretions by eutopic endometrium in infertile women with endometriosis.

Plasma interleukin 11 levels correlate with outcome of spontaneous intracerebral hemorrhage

BACKGROUND

Interleukin (IL) 11 is a multipotential cytokine with anti-inflammatory and fibrogenic properties. It is released into the peripheral blood from damaged brain tissue. The objective of this study was to determine plasma and cerebral spinal fluid (CSF) levels of IL-11 in patients with spontaneous intracerebral hemorrhage (ICH) and to correlate IL-11 with survival, related edema of the brain, volume of hematoma, and hydrocephalus.

METHODS

Forty-three patients with spontaneous ICH were included. Twenty-three were male, and 20 were female. The mean age of the patients was 64.3 years. Plasma and CSF samples were collected on the first, second, third, and fourth days after spontaneous ICH onset.

RESULTS

The levels of IL-11 in CSF (123.9 +/- 107 pg/mL) were 5 times higher than those in plasma (25.5 +/- 18.0 pg/mL) on the first day (P = .001 by paired t test) in our spontaneous ICH patients, and this significant difference persisted up to the third day of ICH. Plasma IL-11 levels in the nonsurvival group (41.2 +/- 18.9 pg/mL) were significantly higher than those in the survival group (22.2 +/- 15.2 pg/mL) on the second day of ICH onset (P = .024 by Mann-Whitney U test), and the significant difference extended to the fourth day. Plasma IL-11 levels of the hydrocephalus group were higher than those of the nonhydrocephalus group in the first 4 days of ICH, but the difference was not statistically significant.

CONCLUSIONS

IL-11 was highly associated with mortality caused by spontaneous ICH and correlated with the hydrocephalus occurring after ICH onset. It is our belief that IL-11 can be a useful clinical marker for spontaneous ICH patients.

Analysis of systemic interleukin-11 after major trauma

Recent data have shown that anti-inflammatory responses to major injury occur immediately after trauma. Interleukin 11 (IL-11), a member of the IL-6 family, is a pleiotropic cytokine with hematopoietic, osteotrophic, and mucosa protective properties, as well as anti-inflammatory functions. IL-11 inhibits synthesis of proinflammatory cytokines, promotes a Th2-type immune response, and improves outcome after shock and sepsis in different animal models. To further investigate the role of IL-11 in the human posttraumatic immune response, we measured plasma levels of IL-11 in 216 multiple-injured patients (mean age of 40 +/- 16 [range 11-81] years; Injury Severity Score [ISS] of 31 +/- 11 [range 16-66] points; 52 women and 164 men) after injury and correlated this with demographics, clinical course, and other laboratory parameters. IL-11 was significantly elevated in polytraumatized patients compared with healthy donors (P <0.0001). The time course of IL-11 in surviving patients was an initial increase after trauma with a decrease during the first 4 weeks, whereas nonsurvivors (n=34) had a significant increase later after injury (4 weeks). IL-11 was significantly higher after abdominal trauma and in men. No correlation between systemic IL-11 and ISS or age was detected. IL-11 correlated significantly with other pro- and anti-inflammatory cytokines such as IL-18. Our data demonstrate elevated levels of systemic IL-11 after multiple injuries; however, the role of a posttraumatic increase of IL-11 has to be further analyzed. In contrast to IL-6, IL-11 in plasma does not correlate with trauma severity and seems to have no clinical relevance to outcome prediction after trauma.

Gene expression profiling of pulpal tissue reveals the molecular complexity of dental caries

High-throughput characterisation of the molecular response of pulpal tissue under carious lesions may contribute to improved future diagnosis and treatment. To identify genes associated with this process, oligonucleotide microarrays containing approximately 15,000 human sequences were screened using pooled total RNA isolated from pulpal tissue from both healthy and carious teeth. Data analysis identified 445 genes with 2-fold or greater difference in expression level, with 85 more abundant in health and 360 more abundant in disease. Subsequent gene ontological grouping identified a variety of processes and functions potentially activated or down-modulated during caries. Validation of microarray results was obtained by a combination of real-time and semi-quantitative PCR for selected genes, confirming down-regulation of Dentin Matrix Protein-1 (DMP-1), SLIT 2, Period-2 (PER 2), Period-3 (PER 3), osteoadherin, Glypican-3, Midkine, activin receptor interacting protein-1 (AIP 1), osteoadherin and growth hormone receptor (GHR), and up-regulation of Adrenomedullin (ADM), Interleukin-11 (IL-11), Bone sialoprotein (BSP), matrix Gla protein (MGP), endothelial cell growth factor-1 (ECGF 1), inhibin beta A and orosomucoid-1 (ORM 1), in diseased pulp. Real-time PCR analyses of ADM and DMP-1 in a panel of healthy and carious pulpal tissue and also in immune system cells highlighted the heterogeneity of caries and indicated increased expression of ADM in neutrophils activated by bacterial products. In contrast, DMP-1 was predominantly expressed by cells native to healthy pulpal tissue. This study has greatly extended our molecular knowledge of dental tissue disease and identified involvement of genes previously unassociated with this process.

Leiomyoma and myometrial gene expression profiles and their responses to gonadotropin-releasing hormone analog therapy

Gene microarray was used to characterize the molecular environment of leiomyoma and matched myometrium during growth and in response to GnRH analog (GnRHa) therapy as well as GnRHa direct action on primary cultures of leiomyoma and myometrial smooth muscle cells (LSMC and MSMC). Unsupervised and supervised analysis of gene expression values and statistical analysis in R programming with a false discovery rate of P < or = 0.02 resulted in identification of 153 and 122 differentially expressed genes in leiomyoma and myometrium in untreated and GnRHa-treated cohorts, respectively. The expression of 170 and 164 genes was affected by GnRHa therapy in these tissues compared with their respective untreated group. GnRHa (0.1 microm), in a time-dependent manner (2, 6, and 12 h), targeted the expression of 281 genes (P < or = 0.005) in LSMC and MSMC, 48 of which genes were found in common with GnRHa-treated tissues. Functional annotations assigned these genes as key regulators of processes involving transcription, translational, signal transduction, structural activities, and apoptosis. We validated the expression of IL-11, early growth response 3, TGF-beta-induced factor, TGF-beta-inducible early gene response, CITED2 (cAMP response element binding protein-binding protein/p300-interacting transactivator with ED-rich tail), Nur77, growth arrest-specific 1, p27, p57, and G protein-coupled receptor kinase 5, representing cytokine, common transcription factors, cell cycle regulators, and signal transduction, at tissue levels and in LSMC and MSMC in response to GnRHa time-dependent action using real-time PCR, Western blotting, and immunohistochemistry. In conclusion, using different, complementary approaches, we characterized leiomyoma and myometrium molecular fingerprints and identified several previously unrecognized genes as targets of GnRHa action, implying that local expression and activation of these genes may represent features differentiating leiomyoma and myometrial environments during growth and GnRHa-induced regression.

Interleukin-11 expression: its significance in eutopic and ectopic human implantation

Embryo implantation and subsequent decidualization, trophoblast invasion and formation of a functional placenta are crucial for establishment and maintenance of pregnancy. Interleukin-11 signalling has been shown to be obligatory for adequate decidualization and trophoblast invasion in mice. Defects in IL-11 signalling in mice result in trophoblast over-invasion and fetal loss. The pathological situation of human tubal pregnancy resembles that of IL-11Ralpha(-/-) mice concerning these symptoms. As our interest is focused on the human early pregnancy, we compared IL-11 expression at the implantation site of ectopic tubal pregnancy (EP) to 1st and 2nd trimester of normal intrauterine pregnancies (IP), and to the normal cycling endometrium. The mRNA expression of IL-11 and IL-11Ralpha was analysed by semiquantitative RT-PCR. Protein expression was detected by western blotting and immunohistochemistry. IL-11Ralpha is expressed constitutively in all tissue specimens analysed. IL-11 is expressed predominantly during follicular and early luteal phase of the menstrual cycle. In IP, IL-11 expression peaks during the 1st trimester and declines from the beginning of the 2nd trimester onwards. In tubal abortions, IL-11 expression is reduced in comparison to vital EP and IP. Cultured primary endometrial and decidual epithelial cells were analysed for hormonal regulation of IL-11 by enzyme-linked immunosorbent assay and RT-PCR. IL-11 is up-regulated by estrogen and down-regulated by progesterone. Overall, our results indicate that in humans, IL-11 signalling is significantly involved in regulation of trophoblast invasion. In the case of tubal abortion, inadequate IL-11 signalling may therefore result in dysregulation of trophoblast invasion.

Alternagin-C, a Disintegrin-like Protein, Induces Vascular Endothelial Cell Growth Factor (VEGF) Expression and Endothelial Cell Proliferation in Vitro

Alternagin-C (ALT-C), a disintegrin-like protein purified from the venom of the Brazilian snake Bothrops alternatus, interacts with the major collagen I receptor, the alpha(2)beta(1) integrin, inhibiting collagen binding. Here we show that ALT-C also inhibits the adhesion of a mouse fibroblast cell line (NIH-3T3) to collagen I (IC(50) 2.2 microm). In addition, when immobilized on plate wells, ALT-C supports the adhesion of this cell line as well as of human vein endothelial cell (HUVEC). ALT-C (3 microm) does not detach cells that were previously bound to collagen I. ALT-C (5 nm) induces HUVEC proliferation in vitro, and it inhibits the positive effect of vascular endothelial growth factor (VEGF) or FGF-2 on the proliferation of these cells, thus suggesting a common mechanism for these proteins. Gene expression analysis of human fibroblasts growing on ALT-C- or collagen-coated plates showed that ALT-C and collagen I induce a very similar pattern of gene expression. When compared with cells growing on plastic only, ALT-C up-regulates the expression of 45 genes including the VEGF gene and down-regulates the expression of 30 genes. Fibroblast VEGF expression was confirmed by RT-PCR and ELISA assay. Up-regulation of the VEGF gene and other growth factors could explain the positive effect on HUVEC proliferation. ALT-C also strongly activates Akt/PKB phosphorylation, a signaling event involved in endothelial survival and angiogenesis. In conclusion, ALT-C acts as a survival factor, promoting adhesion and endothelial cell proliferation.

B-type natriuretic peptide exerts broad functional opposition to transforming growth factor-beta in primary human cardiac fibroblasts: fibrosis, myofibroblast conversion, proliferation, and inflammation

The natriuretic peptides, including human B-type natriuretic peptide (BNP), have been implicated in the regulation of cardiac remodeling. Because transforming growth factor-beta (TGF-beta) is associated with profibrotic processes in heart failure, we tested whether BNP could inhibit TGF-beta-induced effects on primary human cardiac fibroblasts. BNP inhibited TGF-beta-induced cell proliferation as well as the production of collagen 1 and fibronectin proteins as measured by Western blot analysis. cDNA microarray analysis was performed on RNA from cardiac fibroblasts incubated in the presence or absence of TGF-beta and BNP for 24 and 48 hours. TGF-beta, but not BNP, treatment resulted in a significant change in the RNA profile. BNP treatment resulted in a remarkable reduction in TGF-beta effects; 88% and 85% of all TGF-beta-regulated mRNAs were affected at 24 and 48 hours, respectively. BNP opposed TGF-beta-regulated genes related to fibrosis (collagen 1, fibronectin, CTGF, PAI-1, and TIMP3), myofibroblast conversion (alpha-smooth muscle actin 2 and nonmuscle myosin heavy chain), proliferation (PDGFA, IGF1, FGF18, and IGFBP10), and inflammation (COX2, IL6, TNFalpha-induced protein 6, and TNF superfamily, member 4). Lastly, BNP stimulated the extracellular signal-related kinase pathway via cyclic guanosine monophosphate-dependent protein kinase signaling, and two mitogen-activated protein kinase kinase inhibitors, U0126 and PD98059, reversed BNP inhibition of TGF-beta-induced collagen-1 expression. These findings demonstrate that BNP has a direct effect on cardiac fibroblasts to inhibit fibrotic responses via extracellular signal-related kinase signaling, suggesting that BNP functions as an antifibrotic factor in the heart to prevent cardiac remodeling in pathological conditions.

Cell cycle arrest and apoptosis provoked by UV radiation-induced DNA damage are transcriptionally highly divergent responses

DNA damage caused by UV radiation initiates cellular recovery mechanisms, which involve activation of DNA damage response pathways, cell cycle arrest and apoptosis. To assess cellular transcriptional responses to UVC-induced DNA damage we compared time course responses of human skin fibroblasts to low and high doses of UVC radiation known to induce a transient cellular replicative arrest or apoptosis, respectively. UVC radiation elicited >3-fold changes in 460 out of 12,000 transcripts and 89% of these represented downregulated transcripts. Only 5% of the regulated genes were common to both low and high doses of radiation. Cells inflicted with a low dose of UVC exhibited transcription profiles demonstrating transient regulation followed by recovery, whereas the responses were persistent after the high dose. A detailed clustering analysis and functional classification of the targets implied regulation of biologically divergent responses and suggested involvement of transcriptional and translational machinery, inflammatory, anti-proliferative and anti-angiogenic responses. The data support the notion that UVC radiation induces prominent, dose-dependent downregulation of transcription. However, the data strongly suggest that transcriptional repression is also target gene selective. Furthermore, the results demonstrate that dose-dependent induction of cell cycle arrest and apoptosis by UVC radiation are transcriptionally highly distinct responses.

Polarized in vivo expression of IL-11 and IL-17 between acute and chronic skin lesions

BACKGROUND

In atopic dermatitis (AD) there is evidence of tissue fibrosis involving a number of structural changes, including papillary dermal fibrosis and epidermal hyperplasia. These changes are suggested to be the result of chronic inflammation of the skin. Several remodeling-associated cytokines, including transforming growth factor (TGF) beta1, IL-11, and IL-17, have been shown to be increased in allergic diseases, including asthma.

OBJECTIVE

We investigated TGF-beta1, IL-11, and IL-17 expression in skin biopsy specimens recovered from acute and chronic skin lesions from patients with AD, as well as from uninvolved skin of patients with AD and skin from healthy volunteers. We also examined the correlation between the expression of these cytokines and the extent of total, type I, and type III collagen deposition.

METHODS

We evaluated the expression of TGF-beta1, IL-11, and IL-17 by means of immunohistochemistry. Collagen deposition was assessed by means of immunohistochemistry and van Gieson staining.

RESULTS

TGF-beta1 expression was markedly enhanced in both acute and particularly chronic lesions (P <.001). Although IL-11 expression was significantly increased only in chronic lesions (P <.0001), IL-17 was preferentially associated with acute lesions (P <.005). Although collagen type III deposition was not significantly different among the groups, type I collagen deposition was significantly increased in chronic AD lesions (P <.0005). There was a significant correlation between IL-11 and type I collagen deposition, as well as the number of eosinophils in skin specimens from patients with AD (r (2) = 0.527, and r (2) = 0.622, respectively; P <.0001).

CONCLUSION

These results suggest that TGF-beta1, IL-11, and IL-17 are involved in the remodeling of skin lesions in patients with AD. However, IL-11 and IL-17 are preferentially expressed at different stages of the disease. Type I collagen appeared to be the major subtype involved in this repair process.

The cellular paradigm of chlamydial pathogenesis

Diseases caused by Chlamydia are based on intense and chronic inflammation elicited and maintained by reinfection or persistent infection. The traditional view in the field is that disease is mediated by antigen-dependent delayed-type hypersensitivity or autoimmunity. This immunological paradigm has served as the basis for years of chlamydial research but the mechanism or the antigen that causes pathology has yet to be unequivocally revealed. Recent research on responses elicited in Chlamydia-infected cells defines a new direction for our understanding of this microorganism-host interaction and provides the basis for a reassessment of disease mechanisms. Chlamydia-infected non-immune mammalian cells produce proinflammatory chemokines, cytokines, growth factors and other cellular modulators. This cellular response to infection supports an alternative hypothesis for chlamydial pathogenesis: the inflammatory processes of chlamydial pathogenesis are elicited by infected host cells and are necessary and sufficient to account for chronic and intense inflammation and the promotion of cellular proliferation, tissue remodeling and scarring, the ultimate cause of disease sequelae.

Mechanism of the antiulcerogenic effect of IL-11 on acetic acid-induced gastric ulcer in rats

The purpose of this study was to evaluate the healing effect of interleukin-11 (IL-11) on acetic acid-induced gastric ulcer in rats. Gastric ulcers were induced in male Wistar rats by applying acetic acid to the fundus of the stomach. Recombinant human interleukin-11 (rhIL-11 100 microg/kg/twice daily, subcutaneously) was administered starting on the 2nd day before ulcer induction up through the 7th day after ulcer induction. Control rats were injected with bovine serum albumin. At 12 hours and 7 days after ulcer induction, the animals were sacrificed, and the ulcer index, proliferating cell nuclear antigen (PCNA) expression, and IL-11alpha receptor expression in the gastric tissues were studied. The ulcer index of the rhIL-11-treated rats was significantly lower than that of the control rats at the 7th day. The expression of PCNA as evaluated by Western blotting and immunohistochemistry, was enhanced in both the mucosal proliferative zone and proper muscle layer of the rhIL-11-treated rats in comparison with that in the control rats. IL-11alpha receptor expression was observed in the mucosal neck cells of the rhIL-11-treated rats and control rats. These findings suggest that IL-11 accelerates ulcer healing by inducing the proliferation of mucosal and muscular cells.

Modulation of the host response in periodontal therapy

This paper was prepared by the Research, Science, and Therapy Committee of the American Academy of Periodontology to provide the dental profession an overview of current and potential methods to modulate the host response in the treatment of periodontal diseases. Specifically, it discusses components of periodontal disease pathogenesis (i.e., immune and inflammatory responses, excessive production of matrix metalloproteinases and arachidonic acid metabolites, and regulation of bone metabolism) and their modulation.

Pathophysiological tissue changes associated with repetitive movement: a review of the evidence

Work-related musculoskeletal disorders (WMSDs) represent approximately one third of workers' compensation costs in US private industry, yet estimates of acceptable exposure levels for forceful and repetitive tasks are imprecise, in part, due to lack of measures of tissue injury in humans. In this review, the authors discuss the scope of upper-extremity WMSDs, the relationship between repetition rate and forcefulness of reaching tasks and WMSDs, cellular responses to injury in vivo and in vitro, and animal injury models of repetitive, forceful tasks. The authors describe a model using albino rats and present evidence related to tissue injury and inflammation due to a highly repetitive reaching task. A conceptual schematic for WMSD development and suggestions for further research are presented. Animal models can enhance our ability to predict risk and to manage WMSDs in humans because such models permit the direct observation of exposed tissues as well as motor behavior.

Intracellular cytokine production by fetal and adult monocytes

BACKGROUND/PURPOSE

In light of the neonate's increased susceptibility to systemic infection, the authors hypothesized that adult and fetal monocytes have different cytokine expression profiles in response to lipopolysaccharide (LPS), and interleukin (IL)-11, a counter-inflammatory cytokine.

METHODS

Samples of cord blood (n = 30) and adult blood (n = 30) were obtained and treated as follows: control (baseline expression), LPS exposure, and IL-11 or IL-11+LPS exposure. After incubation with a protein transport inhibitor, mononuclear cells were stained for intracellular tumor necrosis factor (TNF)-alpha, IL-1beta, IL-6, and IL-8. Each sample was then analyzed by flow cytometry for cytokine expression. Cytokine production was measured by the percent positive as well as the fluorescence index for each cytokine. Analysis of variance (ANOVA) and Students t tests were used for statistical analysis.

RESULTS

Baseline levels of IL-8 were significantly higher for fetal monocytes (P <.0001). After LPS exposure, fetal monocytes produced less TNF-alpha (P =.0105) and more IL-8 (P <.0007) relative to adult cells. IL-11 treatment reduced baseline production of IL-8 in fetal and adult monocytes (P <.05).

CONCLUSIONS

These results suggest that neonatal monocytes portray a different cytokine expression profile compared with adult monocytes. IL-11 treatment appears to alter the IL-8 expression of resting fetal and adult monocytes.

Expression of IL-5 alters bone metabolism and induces ossification of the spleen in transgenic mice

We have developed a transgenic mouse line, NJ.1638, which expresses high levels of IL-5 from T cells, with profound hematological consequences. Eosinophils comprise more than 60% of circulating white blood cells in these animals, with the total peripheral white blood cell counts increasing more than 40-fold relative to wild-type littermates. This extraordinary proliferative capacity is sustained by expanded sites of extramedullary hematopoiesis and is accompanied by multifocal, ectopic bone formation in the spleen. Histology of the splenic nodules revealed the presence of osteoid matrices and osteocytes trapped within mineralized trabecular plates. In addition, polarized light microscopy of calcified tissue sections revealed both woven bone and areas of organized lamellar bone. Morphometric assessments demonstrated that both the growth and mineralization of splenic bone occurred at rates nearly an order of magnitude higher than in skeletal bone. Skeletal bone metabolic parameters were also perturbed. We also observed heterotopic ossification of the spleen and perturbation of skeletal bone homeostasis following adoptive engraftment of transgenic marrow to wild-type recipients. These data suggest that IL-5 overexpression mediates bone formation through the mobilization of marrow-derived osteogenic progenitors and/or the inhibition of recruited osteoclasts.

Signal transduction system for interleukin-6 and interleukin-11 synthesis stimulated by epinephrine in human osteoblasts and human osteogenic sarcoma cells

Epinephrine increased gene- and protein-expression of interleukin-6 (IL-6) and interleukin-11 (IL-11), which are capable of stimulating the development of osteoclasts from their hematopoietic precursors, in human osteoblast (SaM-1) and human osteosarcoma (SaOS-2, HOS, and MG-63) cell lines. An increase in IL-6 and IL-11 synthesis in response to epinephrine appeared to be a common feature in osteoblastic cells, but the magnitude of expression was different in these cell lines. In HOS cells treated with epinephrine, increases of IL-6 and IL-11 synthesis were inhibited by timolol (a beta-blocker), H-89 (N-[2-((p-bromocinnamyl)amino)ethyl]-5-isoquinolinesulfonamide; an inhibitor of protein kinase A (PKA)) and SB203580 [4-(4-fluorophenyl)-2-(4-methylsulfinylphenyl)-5-(4-pyridyl)1H-imidazole; an inhibitor of p38 mitogen-activated protein kinase (MAPK)], but not by phentolamine (an alpha-blocker), calphostin C [an inhibitor of protein kinase C (PKC)], or PD98059 (2'-amino-3'-methoxyflavone; an inhibitor of classic MAPK), suggesting a common pathway mediated by beta-adrenergic receptors in the PKA and p38 systems involved in the signal transduction of IL-6 and IL-11. Furthermore, expression of both genes was inhibited by curcumin [an inhibitor of activating protein-1 (AP-1) activation], but not by pyrrolidine dithiocarbamate (PDTC) [an inhibitor of nuclear factor (NF)-kappaB]. The pharmacological study suggested that coinduction of the two genes in response to epinephrine occurred via activation of AP-1. The findings of the present study suggest that coinduction of IL-6 and IL-11 in response to epinephrine probably occurs via the PKA and p38 MAPK systems, leading to the transcriptional activation of AP-1 in human osteoblastic cells.

Treatment of lupus-induced thrombocytopenia with recombinant human interleukin-11

Autoimmune thrombocytopenia can be a serious manifestation of systemic lupus erythematosus (SLE) which necessitates treatment with immunosuppressive agents and platelet transfusions. Interleukin-11 (IL-11) is a unique thrombopoietic growth factor which causes proliferation of megakaryocyte progenitors as well as induces megakaryocytic maturation. To our knowledge, this agent has not been used in the treatment of autoimmune thrombocytopenia, since theoretically there is a danger of IL-11 stimulating the immune system by up-regulating the lymphoid stem cells. We describe a 36-year-old splenectomized woman with known SLE who presented with pulmonary hemorrhage, acute renal failure, change in mental status, and severe thrombocytopenia (platelet count 2,000/mm3). Her pulmonary, renal, and central nervous system complications responded to intensive therapy with intravenous (IV) pulse methylprednisone and cyclophosphamide along with hemodialysis. The thrombocytopenia remained refractory to the above treatment plus daily multiple platelet transfusions and IV immunoglobulin. Treatment with recombinant human IL-11 (25 microg/kg/day subcutaneously) was initiated and continued for 5 days. Her platelet count improved to 25,000/mm3 within 48 hours, and she experienced no adverse effects.

gp130 Cytokine family and bone cells

Bone tissue is continually being remodelled according to physiological circumstances. Two main cell populations (osteoblasts and osteoclasts) are involved in this process, and cellular activities (including cell differentiation) are modulated by hormones, cytokines and growth factors. Within the last 20 years, many factors involved in bone tissue metabolism have been found to be closely related to the inflammatory process. More recently, a cytokine family sharing a common signal transducer (gp130) had been identified, which appears to be a key factor in bone remodelling. This family includes interleukin 6, interleukin 11, oncostatin M, leukaemia inhibitory factor, ciliary neurotrophic factor and cardiotrophin-1. This paper provides an exhaustive review of recent knowledge on the involvement of gp130 cytokine family in bone cell (osteoblast, osteoclast, etc.) differentiation/activation and in osteoarticular pathologies.

IL-11 selectively inhibits aeroallergen-induced pulmonary eosinophilia and Th2 cytokine production

IL-11 is a pleiotropic cytokine that induces tissue remodeling with subepithelial fibrosis when expressed in the airway. Its effects on the Th2-dominated airway inflammation that is characteristic of asthma, however, are poorly understood. To characterize the effects of IL-11 on Th2 tissue inflammation, we compared the inflammatory responses elicited by OVA in sensitized mice in which IL-11 is overexpressed in a lung-specific fashion (CC10-IL-11) with that in transgene- wild-type littermate controls. Transgene- and CC10-IL-11 transgene+ mice had comparable levels of circulating Ag-specific IgE after sensitization. OVA challenge of sensitized transgene- mice caused airway and parenchymal eosinophilic inflammation, Th2 cell accumulation, and mucus hypersecretion with mucus metaplasia. Exaggerated levels of immunoreactive endothelial cell VCAM-1, mucin (Muc) 5ac gene expression and bronchoalveolar lavage and lung IL-4, IL-5, and IL-13 protein and mRNA were also noted. In contrast, OVA challenge in CC10-IL-11 animals elicited impressively lower levels of tissue and bronchoalveolar lavage inflammation, eosinophilia, and Th2 cell accumulation, and significantly lower levels of VCAM-1 and IL-4, IL-5, and IL-13 mRNA and protein. IL-11 did not cause a comparable decrease in mucus hypersecretion, Muc 5ac gene expression, or the level of expression of RANTES, monocyte chemoattractant protein-2, or monocyte chemoattractant protein-3. In addition, IL-11 did not augment IFN-gamma production demonstrating that the inhibitory effects of IL-11 were not due to a shift toward Th1 inflammation. These studies demonstrate that IL-11 selectively inhibits Ag-induced eosinophilia, Th2 inflammation, and VCAM-1 gene expression in pulmonary tissues.

Recombinant human interleukin-11 modulates ion transport and mucosal inflammation in the small intestine and colon

Human recombinant interleukin 11 (rhIL-11) is a cytokine that suppresses the clinical signs of colitis in animal models of inflammatory bowel disease (IBD) and may be an effective therapeutic agent in the treatment of IBD. The objective of the current study was to investigate whether rhIL-11 was capable of reversing abnormalities in secretomotor function associated with gut inflammation. We investigated the effects of rhIL-11 on epithelial electrogenic ion transport in the jejunum and colon. Application of rhIL-11 (10 to 10,000 ng/ml) at either the luminal or serosal side of mucosal sheets isolated from control rats induced a concentration-dependent reduction of transmural potential difference (PD) in the jejunum and decreased the short-circuit current (Isc), representative of active electrogenic transport, in the colon. To investigate the effect of rhIL-11 on an inflamed gut, we isolated jejunal and colonic tissue from HLA-B27 transgenic rats with active inflammation of the bowel that represents an animal model of IBD. In jejunum and colon isolated from HLA-B27 transgenic rats, basal electrogenic ion transport was significantly attenuated and, under these conditions, rhIL-11 caused no changes in either transmural PD or Isc. However, in HLA-B27 rats, pretreatment with subcutaneous doses of rhIL-11 suppressed the symptoms of diarrhea, normalized myeloperoxidase activity in the jejunum and colon and healed mucosal injury. In the jejunum from HLA-B27 rats, healing of the intestinal inflammatory response enhanced basal transmural PD and the rhIL-11-duced changes in mucosal ion transport resembled those seen in uninflamed controls. Conversely, in the colon, healing of the mucosa did not normalize basal active ion transport nor did it reverse the inhibition of rhIL-11-induced changes in colonic Isc. Our results suggest that endogenous IL-11 may act as a modulator of epithelial transport under physiologic conditions and may act as a potent anti-inflammatory cytokine during active intestinal inflammation.

Distinct effects of Broncho-Vaxom (OM-85 BV) on gp130 binding cytokines

BACKGROUND

Broncho-Vaxom (OM-85 BV) is known to support respiratory tract resistance to bacterial infections. In vivo and in vitro studies in animals and humans have shown that the action of the drug is based on the modulation of the host immune response, and it has been found to upregulate interferon gamma (IFN-gamma) and interleukin (IL)-2, IL-6, and IL-8. These immunomodulatory effects of the compound may explain its stimulation on T helper cells and natural killer cells. Following earlier findings that OM-85 BV induces the synthesis of IL-6, a study was undertaken to investigate its possible effect on other gp130 binding cytokines including IL-11, IL-12, leukaemia inhibitory factor (LIF), oncostatin M (OSM), and ciliary neutrophil factor (CNTF). Its modulation of the corresponding receptors of the above mentioned cytokines and of the signal transducer gp130 in human pulmonary fibroblasts and peripheral blood lymphocytes was also studied.

METHODS

Transcription of cytokines was assessed by Northern blot analysis. Secretion of cytokines was analysed using commercially available enzyme linked immunosorbent assay kits. Cytokine receptors and gp130 proteins were determined by Western blot analysis.

RESULTS

OM-85 BV increased the expression of IL-11 in human lung fibroblasts, but not in lymphocytes, in a dose and time dependent manner by maximal fivefold within 20 hours. The compound inhibited serum induced IL-12 expression in peripheral blood lymphocytes but did not induce OSM, LIF, or CNTF at any concentration. In lung fibroblasts the expression of the IL-6 receptor was enhanced fourfold at a concentration of 10 microg/ml OM-85 BV while that of the IL-11 receptor was not altered. In peripheral blood lymphocytes LIF receptor alpha expression was downregulated in the presence of 10 microg/ml OM-85 BV. At a concentration of 10 microg/ml OM-85 BV enhanced gp130 gene transcription fivefold and increased gp130 protein accumulation in cell membranes by 2.5 times.

CONCLUSION

In vitro OM-85 BV exerts immunomodulatory action via modulation of the signal transducer gp130 and gp130 binding cytokines. The increase of IL-6 and IL-11 may explain enhanced T and B cell activity, immunoglobulin synthesis, and IgM to IgG switch. Suppression of IL-12 and LIF receptor-alpha further contributes to organ protection. With regard to gp130 mediated signalling of the investigated cytokines, OM-85 BV modifies the host immune response towards an increased sensitisation of cells to gp130 binding proteins.

Induction of rat L-phosphoserine phosphatase by amyloid-beta (1-42) is inhibited by interleukin-11

Alzheimer's disease (AD) is characterized by the presence of beta-amyloid (Abeta) protein deposits in the brain and increased Abeta (1-42) peptide production is thought to be one of the early events in the pathogenesis of AD that leads to progressive neurodegenerative processes and dementia. Using cDNA subtraction and reverse transcription-polymerase chain reaction, we examined the Abeta (1-42) peptide-induced gene expression in rat neuroblastoma B104 cells. In addition we hypothesized that interleukin-11 (IL-11) supports neuronal survival. We found that Abeta (1-42) activates L-phosphoserine phosphatase in neuronal cells which is inhibited by IL-11. Moreover, IL-11 inhibits Abeta (1-42)-induced neurotoxicity in a dose-dependent manner. Our study suggests that L-phosphoserine phosphatase may play a role in altered neuronal function in AD via enhancing glutamate-induced neurotoxicity by D-serine and the IL-11 receptor system may act as a neuroprotective cytokine in human brain.

Positive and negative hematopoietic cytokines produced by bone marrow endothelial cells

Recently, cytokines and interleukins such as SCF, GM-CSF, G-CSF, TGF-beta, IL-6, IL-7, IL-8, IL-11 have been reported to be elaborated by endothelial cells. For further study, serum free bone marrow endothelial cell conditioned medium (BMEC-CM) was collected and ultrafiltrated by using a centriprep 10. The concentrated retentate (R-BMEC-CM) contained some substances whose molecular weight was more than 10 000 daltons. The filtrate (F-BMEC-CM) contained some substances whose molecular weight was less than 10 000 daltons. The effects of R-BMEC-CM and F-BMEC-CM on the growth of haematopoietic progenitors and the expression of cytokine and interleukin mRNAs of BMEC were investigated. The results showed that R-BMEC-CM stimulated the growth of CFU-GM, HPP-CFC, BFU-E, CFU-E, and CFU-Meg; while F-BMEC-CM inhibited the growth of these progenitors. Using the method of hybridizing to the Atlas cDNA Array, we were able to detect the presence of mRNAs of cytokines and interleukins in bone marrow endothelial cells. Our finding of the existence of mRNAs of SCF, GM-CSF, IL-6, TGF-beta, IL-1, and IL-11 in these cells was in agreement with the data reported previously. Furthermore, we detected mRNAs of MIP-2, Thymosion-beta4, PDGF, MSP-1, IFN-gamma, IL-13 and inhibin, which are related to haematopoiesis. Among these cytokines and interleukins, SCF, GM-CSF, IL-6, IL-1, and IL-11 are haematopoietic stimulators which may be responsible for the stimulative effects on the growth of haematopoietic progenitors. One of our new findings, the thymosin-beta4, is a small molecular haematopoietic inhibitor. It may be responsible for the inhibitory effect of F-BMEC-CM on haematopoietic progenitors. The presence of mRNAs of BMP, MSP-1, MIP-2, PDGF and IL-13 suggests that bone marrow endothelial cells might elaborate these substances. Their influence on haematopoietic progenitors needs further study.

The effect of interleukin-11 on the progression of ligature-induced periodontal disease in the beagle dog

BACKGROUND

The rate of progression of periodontal disease is dependent on the complex regulatory interactions between bacteria and the immune modulators of the host response. The purpose of this investigation was to determine if recombinant human interleukin-11 (rhIL-11), known to downregulate several inflammatory modulators, has the ability in subcutaneous administration to reduce the rate and/or extent of periodontal attachment loss and radiographic bone loss in a ligature-induced periodontal disease beagle dog model.

METHODS

Twenty 18-month-old female beagle dogs were brought to optimal periodontal health over a 2-week period. Periodontal disease was induced by placing 2.0 silk ligatures around the mandibular first molar and premolar teeth. The dogs were divided into 3 treatment groups and one control group. The 3 treatment groups received subcutaneous injections of either 15, 30, or 80 microg/kg of rhIL-11 in saline buffer twice a week. The placebo group received buffer only subcutaneously twice a week. The gingival health of each animal was measured by recording the presence or absence of gingival inflammation, plaque, and bleeding upon probing. Attachment levels and bone height were also measured. Treatment administration and clinical and radiographic evaluations were performed in a masked fashion.

RESULTS

At week 8, the placebo group had 3.89 mm of attachment loss and 73.8% radiographic bone remaining. The 15 microg/kg group had 1.99 mm attachment loss and 89.5% bone remaining; the 30 microg/kg group had 0.84 mm attachment loss and 92.5% bone remaining; and the 80 microg/kg group had 1.05 mm attachment loss and 85.5% bone remaining. All 3 treatment groups lost significantly less attachment and retained significantly more bone than did the placebo group.

CONCLUSIONS

The study indicates that subcutaneous injections of rhIL-11 were able to slow the progression of attachment and radiographic alveolar bone loss in a ligature-induced beagle dog model.

Development of a lyophilization formulation that preserves the biological activity of the platelet-inducing cytokine interleukin-11 at low concentrations

Recombinant human interleukin-11 (rhIL-11) is a licensed biological therapeutic product in at least one country and is used to combat thrombocytopenia during chemotherapeutic regimens, as well as undergoing clinical trials for a range of other disorders. Following attempts to lyophilize IL-11 at low concentrations, it was clear that a significant loss of recoverable biological activity occurred. Investigation of a variety of factors, including the type of container in which the rhIL-11 was lyophilized, revealed that surface adsorption to glass was a major factor resulting in loss of activity of rhIL-11 in solution (> 40% reduction after 3 h at room temperature), in addition to losses of activity post-lyophilization. To overcome this problem, different formulations containing combinations of human serum albumin (HSA), trehalose and Tween-20 have been investigated. Two formulations were successful in entirely preserving the biological activity of rhIL-11 through lyophilization and subsequent reconstitution (potency estimates of formulated relative to original material being > or =0.97). Accelerated degradation studies, performed at intervals over a six-month period, demonstrated the stability of freeze-dried rhIL-11 using these formulations (predicted annual reduction in potency after storage at -20 degrees C < or =1.4%). In conclusion, we have developed a working combination of excipients (0.5% HSA, 0.1% trehalose and 0.02% Tween-20 in potassium phosphate buffer (pH 7.4)) to formulate a stable rhIL-11 freeze-dried product in glass containers, with no loss in potency. These findings should facilitate development of low dose rhIL-11 products and be an indicator of caution to those using this and other material with similar physical properties, without taking appropriate precautions to avoid losses through adsorption.

Human endothelium as a source of multifunctional cytokines: molecular regulation and possible role in human disease

Endothelial cells, by virtue of their capacity to express adhesion molecules and cytokines, are intricately involved in inflammatory processes. Endothelial cells have been shown to express interleukin-1 (IL-1), IL-5, IL-6, IL-8, IL-11, IL-15, several colony-stimulating factors (CSF), granulocyte-CSF (G-CSF), macrophage CSF (M-CSF) and granulocyte-macrophage CSF (GM-CSF), and the chemokines, monocyte chemotactic protein-1 (MCP-1), RANTES, and growth-related oncogene protein-alpha (GRO-alpha). IL-1 and tumor necrosis factor-alpha (TNF-alpha) produced by infiltrating inflammatory cells can induce endothelial cells to express several of these cytokines as well as adhesion molecules. Induction of these cytokines in endothelial cells has been demonstrated by such diverse processes as hypoxia and bacterial infection. Recent studies have demonstrated that adhesive interactions between endothelial cells and recruited inflammatory cells can also signal the secretion of inflammatory cytokines. This cross-talk between inflammatory cells and the endothelium may be critical to the development of chronic inflammatory states. Endothelial-derived cytokines may be involved in hematopoiesis, cellular chemotaxis and recruitment, bone resorption, coagulation, and the acute-phase protein synthesis. As many of these processes are critical to the maturation of an inflammatory and reparative state, it appears likely that endothelial-derived cytokines play a crucial role in several diseases, including atherosclerosis, graft rejection, asthma, vasculitis, and sepsis. Genetic and pharmacologic manipulation of endothelial-derived cytokines provides an additional approach to the management of chronic inflammatory diseases.