Expression Of IL-1alpha Research Articles

Marsupialization inhibits interleukin-1alpha expression and epithelial cell proliferation in odontogenic keratocysts.

Marsupialization results in the reduction of odontogenic cyst size. Interleukin-1alpha (IL-1alpha) is thought to play a crucial role for the expansion of odontogenic keratocysts. The aim of this study was to investigate the effects of marsupialization on the expression of IL-1alpha and on the proliferating activity of a lining epithelium in odontogenic keratocysts. The concentrations of IL-1alpha, interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-alpha) in the intracystic fluids of odontogenic keratocysts were measured by the enzyme-linked immunosorbent assay (ELISA). The expression of IL-1alpha mRNA in odontogenic keratocysts was measured before and after marsupialization by in situ hybridization. The expression of IL-1alpha and epithelial cell-proliferating activities in odontogenic keratocysts were also measured by immunohistochemistry using antibodies for human IL-1alpha and Ki-67 antigen, respectively. The intracystic fluid levels of IL-1alpha were significantly higher than those of IL-6 and TNF-alpha in odontogenic keratocysts. In situ hybridization and immunohistochemistry showed that strong expression of IL-1alpha mRNA and protein was mainly detected in the epithelial cells of odontogenic keratocysts. After marsupialization, the signal intensities for IL-1alpha mRNA and protein were significantly decreased. In addition, the Ki-67 labeling index of the epithelial cells was decreased proportionally with the grade of IL-1alpha mRNA expression after the marsupialization. Our findings suggest that marsupialization may reduce the size of odontogenic keratocyst by inhibiting IL-1alpha expression and the epithelial cell proliferation.

Expression of interleukin-1 (IL-1) system genes in equine cumulus-oocyte complexes and influence of IL-1beta during in vitro maturation.

A growing body of evidence suggests that the ovary is a site of inflammatory reactions, and thus, ovarian cells could represent sources and targets of the interleukin-1 (IL-1) system. The aim of the present work was to investigate the expression of IL-1alpha, IL-1beta, IL-1ra, IL-1R1, and IL-1R2 genes in equine cumulus cells and oocytes. Moreover, the influence of IL-1beta on in vitro maturation of cumulus-oocytes complexes (COCs) was examined. COCs were collected using ultrasound-guided follicular puncture in vivo. Oocytes and cumulus cells were isolated from preovulatory and subordinate follicles and were analyzed either at collection or after in vitro culture. An ultrasensitive reverse transcription-polymerase chain reaction was used to study the expression of IL-1 system members. In order to study the in vitro effect of IL-1beta on oocyte nuclear maturation and cumulus expansion, immature COCs collected from subordinate follicles were cultured for 30 h in media containing or not containing IL-1beta alone, or in combination with equine luteinizing hormone. Our results indicated that equine oocytes expressed IL-1beta and IL-1R2 genes, and that cumulus cells expressed all IL-1 system members except IL-1alpha. In oocytes, IL-1beta expression significantly decreased during in vitro culture compared with immature and mature oocytes analyzed at collection. Similarly, in cumulus cells, in vitro culture decreased IL-1ra and IL-1R1 expression. IL-1beta was shown to significantly decrease the gonadotropin-induced nuclear maturation of oocytes. In conclusion, we demonstrated for the first time, in mares, the presence of IL-1beta and IL-1R2 transcripts in oocytes and of IL-1beta, IL-1ra, IL-1R1, and IL-1R2 in cumulus cells. The regulatory effect of IL-1beta on COCs during maturation suggests that the IL-1 system could be of crucial importance for ovarian physiology in the mare.

Inhibitory effects of toremifene on N-methyl-N-nitrosourea and estradiol-17beta-induced endometrial carcinogenesis in mice.

Short‐ and long‐term experiments were designed to determine the effects of toremifene (TOR) on estrogen‐related endometrial carcinogenesis in mice. In the short‐term experiment, a single low dose of TOR (0.2 mg/30 g body weight) decreased expression of c‐fos, interleukin (IL)‐1α, estrogen receptor (ER)‐α mRNAs and corresponding proteins induced by estradiol‐l7β (E2), in the uteri of the ovariectomized mice. Expression of ER‐β mRNA was increased by the TOR treatment, compared with the control. In the long‐term experiment, 106 female ICR mice were given N‐methyl N‐nitrosourea (MNU) into their uterine corpora. The animals were divided into four groups as follows: group 1, E2 diet (5 ppm) plus TOR (0.2 mg/30 g body weight, subcutaneously, every four weeks); group 2, E2 diet alone; group 3, basal diet plus TOR. Group 4 served as the control. TOR treatment decreased the incidence of MNU and E2‐induced endometrial adenocarcinoma and atypical hyperplasia at the termination of the experiment (30 weeks after the start). These results suggest that TOR exerts preventive effects against estrogen‐related endometrial carcinogenesis in mice, through the suppression of c‐fos as well as IL‐1α expression induced by E2. Such suppressive effects of TOR may be related to the decreased ER‐α and increased ER‐β expressions.

Cytokine production induced by a 67-kDa fimbrial protein from Porphyromonas gingivalis.

Fimbriae have been reported to play an important role in the adherence of Porphyromonas gingivalis to oral surfaces and possibly in triggering host responses. P. gingivalis ATCC 33277 has two distinctly different fimbriae expressed on the cell surface. The 67-kDa fimbriae differ in size and antigenicity from the earlier reported FimA, a major 41-kDa fimbrial component of P. gingivalis. Expression of the 67-kDa fimbriae on the cell surface of a fimA mutant was investigated by electron microscopy. The 67-kDa fimbrial protein was purified from the fimA mutant by sonication, precipitation, and chromatography on a DEAE Sepharose CL-6B column. The N-terminal amino acid sequence of the 67-kDa fimbrillin was distinct from that of the 41-kDa fimbrillin. Moreover, we have found that the 67-kDa fimbrial protein from P. gingivalis ATCC 33277 induced IL-1alpha, IL-beta, IL-6 and TNFalpha cytokine expression in mouse peritoneal macrophages. These results suggest that P. gingivalis 67-kDa fimbriae may play a part in the inflammatory response during the development of periodontal diseases.

The cytokine network of Wallerian degeneration: tumor necrosis factor-alpha, interleukin-1alpha, and interleukin-1beta.

Wallerian degeneration (WD) is the inflammatory response of the nervous system to axonal injury, primarily attributable to the production of cytokines, the mediator molecules of inflammation. We presently document the involvement of the inflammatory cytokines TNFalpha, interleukin (IL)-1alpha, and IL-1beta in peripheral nerve (PNS) injury in C57/BL/6NHSD (C57/BL) mice that display the normal rapid progression of WD (rapid-WD) and C57/BL/6-WLD/OLA/NHSD mice that display abnormal slow progression of WD (slow-WD). TNFalpha and IL-1alpha mRNAs were expressed, whereas TNFalpha but not IL-1alpha protein was synthesized in intact PNS of C57/BL mice. TNFalpha and IL-1alpha protein synthesis and secretion were rapidly upregulated during rapid-WD in Schwann cells. IL-1beta mRNA expression and protein synthesis and secretion were induced sequentially in Schwann cells with a delay after injury. Thereafter, recruited macrophages contributed to the production of TNFalpha, IL-1alpha, and IL-1beta, which in turn augmented myelin phagocytosis by macrophages. Observations suggest that TNFalpha and IL-1alpha are the first cytokines with protein production that is upregulated during rapid-WD. TNFalpha and IL-1alpha may initiate, therefore, molecular and cellular events in rapid-WD (e.g., the production of additional cytokines and NGF). TNFalpha, IL-1alpha, and IL-1beta may further regulate, indirectly, macrophage recruitment, myelin removal, regeneration, and neuropathic pain. In contrast to rapid-WD, the production of TNFalpha, IL-1alpha, and IL-1beta protein was deficient in slow-WD, although their mRNAs were expressed. mRNA expression and protein production of TNFalpha, IL-1alpha, and IL-1beta were differentially regulated during rapid-WD and slow-WD, suggesting that mRNA expression, by itself, is no indication of the functional involvement of cytokines in WD.

Cytokine activity contributes to induction of inflammatory cytokine mRNAs in spinal cord following contusion.

Injury of the spinal cord leads to an inflammatory tissue response, probably mediated in part by cytokines. Because a common therapy for acute spinal cord injury is the use of an antiinflammatory synthetic glucocorticoid (methylprednisolone), we sought to determine mechanisms contributing to inflammation shortly after acute injury. Cytokine mRNAs [interleukin (IL)-1alpha, IL-1beta, tumor necrosis factor (TNF)-alpha, and IL-6] were increased during the first 2 hr following weight-drop compression injury by RNase protection assay, prior to the reported appearance of circulating lymphocytes. This immediate pattern of cytokine mRNA induction could be replicated in cultured, explanted spinal cord slices but not in whole blood of injured animals, which is consistent with a tissue source of cytokine mRNAs. Western blotting detected IL-1beta-like immunoreactivity released into culture medium following explantation and pro-IL-1beta-like immunoreactivity in freshly dissected spinal cord tissue. Pharmacologically blocking IL-1 and TNF-alpha receptors significantly reduced expression of IL-1alpha, IL-1beta, and TNF-alpha mRNAs. Finally, mice lacking both IL-1 and TNF-alpha receptors exhibited diminished induction of TNF-alpha, IL-6, and IL-1ra mRNAs following injury. Therefore, we conclude that contusion injury induces an immediate release of cytokines, which then contributes to the induction of cytokine mRNAs.

Eicosapentaenoic Acid, a n-3 Polyunsaturated Fatty Acid Differentially Modulates TNF-α, IL-1α, IL-6 and PGE2 Expression in UVB-Irradiated Human Keratinocytes

In response to UVB-irradiation keratinocytes release a variety of cytokines and prostaglandins, including tumor necrosis factor alpha (TNF-alpha), interleukin 1alpha (IL-1alpha), interleukin 6 (IL-6), and prostaglandin E2 (PGE2). n-3 Polyunsaturated fatty acids (PUFA), mainly present in fish oil, can modulate cytokine synthesis, as predominantly studied in macrophages. In order to investigate the immune modulating actions of n-3 PUFA on the UVB response in human skin, we investigated the effect of eicosapentaenoic acid (EPA), a n-3 PUFA and a precursor of eicosanoid biosynthesis, on UVB-modulated TNF-alpha, IL-1alpha, IL-6, and PGE2 expression in normal human keratinocytes (NHK). We show that cultured NHK can efficiently take up EPA. Basal TNF-alpha expression is very low in NHK. IL-1alpha on the contrary is significantly present in untreated cultured NHK. Upon UVB-irradiation (32 mJ per cm2) TNF-alpha mRNA expression and secretion is induced and IL-1alpha mRNA expression is reduced, although IL-1alpha secretion is induced. EPA treatment results in higher TNF-alpha and IL-1alpha expression, both in nonirradiated and UVB-irradiated keratinocytes. Moreover EPA and UVB appear to act synergistically to superinduce TNF-alpha expression. EPA treatment results also in lipid peroxidation and in decreased PGE2 and IL-6 secretion after UVB-irradiation. In contrast to EPA, oleic acid (monounsaturated fatty acid) and linoleic acid (n-6 PUFA) treatment did not result in higher TNF-alpha or IL-1alpha levels in nonirradiated or UVB-irradiated NHK, indicating that the observed effects are specific for EPA. In conclusion, these results show that EPA can differentially modulate UVB-induced cytokine and prostaglandin synthesis in NHK.

Induction of acute phase response genes in keratinocytes following exposure to oligodeoxynucleotides.

Keratinocytes have the ability to take up oligodeoxynucleotides (ODN) and plasmid DNA probably by receptor-mediated endocytosis. Despite the use of DNA for antisense and gene therapy little is known about the regulation of genes following exposure to nucleic acids. To systematically identify gene regulation in keratinocytes upon exposure to ODN we screened human cytokine DNA arrays containing 383 different genes and found interleukin (IL) 1alpha, IL-1beta, integrin-beta(1), alpha-tubulin, and follistatin highly induced, while most genes were unaffected. The time course and concentration dependence for IL-1alpha and follistatin expression were analyzed by standard northern blot technique. ODN of different length and sequence induced comparable amounts of IL-1alpha and follistatin. Their induction was independent of negative charge and of several proinflammatory compounds such as lipopolysaccharides, IL-1beta, and interferon-gamma but was partly inhibited by activin A. In summary, our study revealed several genes of the acute phase protein family that are induced in a non-sequence-specific manner following the exposure of normal human keratinocytes to ODN. Therefore it is tempting to speculate that upon internalization ODN bind to an intracellular receptor (e.g., Toll-like receptor 9) which mediates signaling.

Bioglass attenuates a proinflammatory response in mouse peritoneal endotoxicosis.

Bioglass is a bioactive, resorbable ceramic particle that was developed to assure binding to living tissues. Bioglass is currently employed to fill osseus defects in oral surgery, and it possesses both unique anti-inflammatory and antimicrobial properties. In an effort to determine whether Bioglass may be useful as an adjunct anti-inflammatory device in local inflammatory processes, we examined whether exposure of the peritoneal cavity to Bioglass would induce a pro- or anti-inflammatory response, and then modulate a subsequent proinflammatory response to endotoxin. Three- to fifty-milligram doses of 5 pm Bioglass were administered intraperitoneally in C57BL/6 mice. Total leukocyte, myeloperoxidase, and cytokine levels in the peritoneal wash fluid were determined. In addition, the peritoneal cavity was preexposed to Bioglass, and was then subjected to a subsequent endotoxin administration. All doses of Bioglass were found to induce a significant peritoneal IL-6 response; however, Bioglass did not induce a TNF-alpha, IL-1alpha, IL-10, or a white cell recruitment into the peritoneal lavage fluid. Pretreatment of the peritoneal cavity with Bioglass produced a transient reduction in the proinflammatory response to endotoxin. We conclude that exposure to Bioglass produces an IL-6 response without concurrent expression of TNF-alpha or IL-1alpha. Bioglass appears to transiently suppress the inflammatory response to endotoxin, possibly through the early induction of IL-6. These findings suggest that Bioglass may offer a unique approach in modifying the inflammatory response in local tissue compartments.

Discrete roles of cytokines, TNF-α, IL-1, IL-6 in tumor promotion and cell transformation

Based on our previous results, which pointed to tumor necrosis factor-alpha (TNF-alpha) as the essential cytokine in tumor promotion in mouse skin, we present here three principal findings related to the specific roles of TNF-alpha, interleukin-1 (IL-1) and IL-6 in tumor promotion (using TNF-alpha- and IL-6-deficient mice) and in BALB/3T3 cell transformation: i) The previously reported residual tumor promotion by 12-O-tetradecanoylphorbol-13-acetate (TPA) in TNF-/- mice was confirmed by experiments with TNF+/+ and TNF-/- 129/Svj mice of the same strain, using two-stage carcinogenesis experiments. TPA produced tumors in 100% of TNF+/+ and 78% of TNF-/- mice at 20 weeks, and the average number of tumors per mouse was 11.1 in the former group and 2.1 in the latter. Judging from the expression of various inflammatory cytokine genes in TNF+/+ and TNF-/- mice, the residual tumor promoting activity of TPA in TNF-/- mice may be dependent on expression of IL-1alpha and IL-1beta genes. ii) Tumor promotion by TPA and okadaic acid in IL-6+/+ and IL-6-/- C57/BL6 mice was studied, with TPA producing tumors in 57.1% of IL-6+/+ and 40.0% of IL-6-/- mice at 20 weeks, and okadaic acid in 40.0% of IL-6+/+ and 53.3% of IL-6-/- mice. Thus, there was no significant difference between TPA or okadaic acid tumor promotion in either group. In addition, expression of IL-6 gene in skin of both types of mice suggested that IL-6 is not the essential cytokine in tumor promotion, since it can be replaced by other cytokines. iii) In transformed clones of BALB/3T3 cells induced by TNF-alpha alone, IL-1alpha gene expression was induced after transformation by TNF-alpha had occurred, which did not occur in parental cells. Expression patterns of TNF-alpha, IL-1beta, IL-6 and IL-10, along with TGF-beta, were similar in both parental and transformed cells. Considering all these results, we conclude that various cytokines have discrete roles in tumor promotion and cell transformation.

Expression of pro-inflammatory cytokines in mouse blastocysts during implantation: modulation by steroid hormones.

Expression and hormonal regulation of pro-inflammatory cytokines and their role in blastocyst activation and implantation is poorly known. The present study is aimed at analysing the expression and hormonal modulation of two pro-inflammatory cytokines [interleukin-1alpha (IL-1alpha) and IL-6] in mouse blastocysts during implantation. Blastocyst-uterine interactions are inhibited by progesterone during implantation and subsequent treatment with oestrogen triggers events that allow implantation to begin. Using this delayed implantation mouse model, dormant and activated blastocysts were recovered from mice treated with progesterone alone and progesterone plus oestrogen therapy, respectively. Expression of IL-1alpha and IL-6 messenger RNA (mRNA) was analysed in normal, dormant and activated blastocysts by in situ hybridization using specific labelled sense and antisense RNA probes, and the protein expression of the same was analysed by immunocytochemistry. In situ hybridization revealed IL-1alpha and IL-6 mRNA localization in normal, dormant and activated blastocysts and a differential expression was observed in relation to the exposure to progesterone and oestrogen. There was less expression in the dormant blastocysts as compared with the normal and activated ones, and the pattern was similar for both cytokines. Immunocytochemistry also revealed a similar pattern of protein expression to that of the mRNA expression for both the cytokines. Using a delayed implantation model, we show that mouse blastocysts express both IL-1alpha and IL-6 mRNA as well as their respective proteins. Both mRNA and the protein levels of IL-1alpha and IL-6 seem to be hormonally modulated in mouse blastocysts during implantation.

Fas engagement increases expression of interleukin-6 in human glioma cells.

Although Fas (APO-1/CD95) is expressed ubiquitously and induces cell death, it is also known to mediate other responses such as inflammation and angiogenesis in vivo. Previously, we have reported that Fas ligation induces selective expression of chemokines (IL-8 and MCP-1) in human astroglioma cells in vitro. In this study, we investigated whether Fas ligation can induce expression of other cytokines. Expression of IL-1alpha, IL-1beta, IL-6, IL-10, IL-12, IFN-beta, IFN-gamma, LT-beta, TGF-beta, TNF-a and TNF-beta mRNA levels in CRT-MG human astroglioma cells upon Fas ligation was investigated using RNase protection assay (RPA). We found that IL-6 mRNA is selectively induced upon Fas ligation, and IL-6 mRNA and protein expression was further investigated using single probe RPA and ELISA. To investigate the in vivo expression of IL-6, human brain specimens were homogenized and ELISA was performed for IL-6 expression. Herein, we demonstrate that: (1) Among these cytokines, only IL-6 was induced upon Fas ligation in a dose- and time-dependent manner; (2) A selective p38 MAP kinase inhibitor, SB202190, and a MEK inhibitor, U0126, suppressed induction of IL-6 mRNA and protein expression by Fas ligation; and (3) Glioblastoma multiforme samples (n = 11) contain significantly higher levels of IL-6 compared to those of control brains (n = 5), which correlate with increased levels of Fas. These results suggest that the Fas-FasL system may play a role in the regulation of tumor growth and survival by inducing the pleiotropic cytokine IL-6.

Differential expression and upregulation of interleukin-1alpha, interleukin-1beta and interleukin-6 by freshly isolated human small intestinal epithelial cells.

BACKGROUND: Small intestinal epithelial cells (SIEC) may contribute to local immune regulation. AIM: To examine production of interleukin (IL)-1alpha, IL-1beta and IL-6 by freshly isolated human SIEC. METHODS: IL-1alpha and IL-1beta mRNA in epithelial layers (EL) prepared from small intestine and in intestinal epithelial cell (EC) lines were examined by reverse transcription-polymerase chain reaction. IL-1alpha, IL-1beta and IL-6 protein expression by SIEC was examined by flow cytometry before and after activation with lipopolysaccharide and epithelial growth factor. RESULTS: IL-1alpha and IL-1beta mRNA was detected in EL and EC lines. Background expression of IL-1alpha and IL-1beta protein by SIEC was observed, which did not increase even following activation. IL-6 protein was expressed by SIEC, in a proportion that increased in two out of three samples following activation. CONCLUSIONS: IL-6 expression and the presence of IL-1alpha and IL-1beta mRNA suggest a role for SIEC in the regulation of local inflammation.

Effects of Pentoxifylline on Inflammatory Cytokine Expression and Acute Pleuropneumonia in Swine

Pentoxifylline, a methylxanthine derivative and nonspecific type 4 phosphodiesterase inhibitor, has been used to improve survival of animals with sepsis and to attenuate lung injury in acute lung inflammation. The purpose of this study was to examine whether pentoxifylline would inhibit the expression of inflammatory cytokines, particularly tumor necrosis factor alpha (TNF), and thereby decrease the pathophysiology of acute porcine pleuropneumonia. E. coli lipopolysaccharide (LPS) and bacterial extracts of A. pleuropneumoniae--induced elevations in TNF mRNA which were fully abrogated by addition of pentoxifylline in both alveolar macrophage and neutrophil cultures. A 30% reduction in the level of LPS-induced interleukin (IL)-1beta mRNA levels also was achieved in macrophages. Pentoxifylline did not affect either IL-1alpha or IL-8 expression in vitro. Pentoxifylline therapy in vivo significantly reduced the number of band neutrophils in swine but did not reduce the pathology associated with pleuropneumonia, including changes in serum zinc, iron, or haptoglobin. Neither did it alter TNF, IL-1, IL-6, or IL-8 expression. Measurement of pentoxifylline and its metabolites in pig sera suggested that efficacious doses of pentoxifylline were probably not achieved in vivo. However, subcutaneous doses of pentoxifylline higher than 25 mg/kg produced transient diarrhea, vomiting, and tremors. These results suggest that pentoxifylline is an effective pharmacological tool for the dissection of cytokine regulation in vitro, but inhibitory concentrations may not be achievable for in vivo pharmacological use in swine.

Glucocorticoids induced the production and gene expression of IL-1alpha through AP-1 and partially NF-kappaB activation in murine epidermal cells.

To investigate the mechanism of the glucocorticoids-induced augmentation of skin response, we have recently reported the modulatory effect of glucocorticoids on the regulation of cytokines production in keratinocytes stimulated with various chemicals in vitro through both NF-kappaB and AP-1 activation. Further to clarify the mechanism in the glucocorticoids-induced augmentation of cytokines production from keratinocytes, we examined the effect of glucocorticoids to keratinocytes without chemical stimulation. Glucocorticoids 10(-4) M inhibited the production of IL-1alpha from Pam 212 cells. However, lower concentration (10(-8)-10(-10) M) of glucocorticoids significantly enhanced the production of IL-1alpha by Pam 212 cells at both the protein and mRNA levels. In contrast, glucocorticoids had no effect on the production of either TNF-alhpa, IL-6, nor GM-CSF by Pam 212 cells cultured for 6 h. Electrophoretic mobility shift assays (EMSA) revealed that 10(-10)-10(-12) M glucocorticoids induced the NF-kappaB activation in Pam 212 cells, however, augmented AP-1 activation by 10(-8)-10(-10) M of glucocorticoids was observed in Pam 212 cells. Furthermore, pyrrolidine dithiocarbamate (PDTC) partially inhibited the IL-1alpha production and completely inhibited NF-kappaB expression by Pam 212 cells. On the other hand, MAP-kinase inhibitors (PD98059, SB202190) completely abrogated not only AP-1 activation but the low concentration glucocorticoids-induced IL-1alpha production. These data indicated that lower concentration of glucocorticoids induced the augmentation of IL-1alpha production from keratinocytes mediated through the AP-1 pathway and partially through NF-kappaB pathway.

Actinobacillus actinomycetemcomitans-induced expression of IL-1alpha and IL-1beta in human gingival epithelial cells: role in IL-8 expression.

Gingival epithelial cells (GEC) are the first cells of the host that encounter the periodontal pathogens. and therefore their role in the initiation of the inflammatory response is critical. We aimed to: 1) characterize the expression of interleukin (IL)- Ialpha and IL-Ibeta in human gingiva and cultured GEC: 2) demonstrate the ability of A. actinomycetemcomitans extracts to upregulate IL-1alpha, IL-1beta and IL-8 expression in GEC in vitro: and 3) characterize the role of IL-1alpha and IL-1beta in the induction of IL-8 expression in GEC in vitro. Ten gingival biopsies (5 inflamed and 5 controls) and cultured GEC were examined for IL-1alpha and IL-Ibeta using immunohistochemical techniques. GEC were also challenged with A. actinomycetemcomitans extracts or IL-1alpha, and secretion of IL-1 and IL-8 was determined by ELISA. In vivo, IL-lalpha and IL-1beta were localized in the gingival epithelium and the infiltrating leukocytes. In vitro, A. actinomycetemcomitans extracts induced a time-dependent expression of IL-1alpha, IL-1beta and IL-8 in GEC. IL-1 inhibitors did not affect A. actinomycetemcomitans-induced IL-8. although they inhibited IL-8 induced by IL-1alpha or IL-1beta. In conclusion, GEC are a major source of IL-1alpha and IL-1beta in the periodontium, which in turn induce additional inflammatory mediators such as IL-8. Therefore GEC can be a potential target for therapeutic intervention in the future.

Hepatocellular proliferation in response to a peroxisome proliferator does not require TNFalpha signaling.

Rodents exposed to peroxisome proliferator xenobiotics respond with marked increases in hepatocellular replication and growth that results in tumor formation. Recently, tumor necrosis factor-alpha (TNFalpha) was proposed as the central mediator of this maladaptive response. To define the role of TNFalpha signaling in hepatocellular growth induced by peroxisome proliferators we administered three daily gavage doses of the potent peroxisome proliferator, Wy-14 643, to mice nullizygous for TNF-receptor I (TNFR1), TNFR2, or both receptors. We demonstrate here that regardless of genotype the mice responded with almost identical increases in liver to body weight ratios and hepatocyte proliferation. Lacking evidence that TNFalpha signaling mediates these effects, we then examined the possible contribution of alternative cytokine pathways. Semi-quantitative, reverse transcriptase polymerase chain reaction analysis revealed that wild type mice acutely exposed to Wy-14 643 had increased hepatic expression of Il1beta, Il1r1, Hnf4, and Stat3 genes. Moreover, hepatic adenomas from mice chronically exposed to Wy-14 643 had increased expression of Il1beta, Il1r1, Il6, and Ppargamma1. Expression of Il1alpha, Tnfalpha, Tnfr1, Tnfr2, Pparalpha, or C/ebpalpha was not altered by acute Wy-14 643 exposure or in adenomas induced by Wy-14643. These data suggest that the hepatic mitogenesis and carcinogenesis associated with peroxisome proliferator exposure is not mediated via TNFalpha but instead may involve an alternative pathway requiring IL1beta and IL6.

Vitamin E suppression of microglial activation is neuroprotective.

Neurotoxic microglial-neuronal interactions have been implicated in the pathogenesis of various neurodegenerative diseases such as Alzheimer's disease, and vitamin E has been shown to have direct neuroprotective effects. To determine whether vitamin E also has indirect neuroprotective effects through suppression of microglial activation, we used a microglial-neuronal coculture. Lipopolysaccharide (LPS) treatment of a microglial cell line (N9) induced a time-dependent activation of both p38 mitogen-activated protein kinase (p38 MAPK) and nuclear factor-kappaB (NFkappaB), with consequent increases in interleukin-1alpha (IL-1alpha), tumor necrosis factor-alpha (TNF-alpha), and nitric oxide (NO) production. Differentiated neuronal cells (PC12 cells treated with nerve growth factor) exhibited marked loss of processes and decreased survival when cocultured with LPS-activated microglia. Preincubation of microglia with vitamin E diminished this neurotoxic effect, independently of direct effects of the antioxidant on the neuronal cells. Microglial NO production and the induction of IL-1alpha and TNFalpha expression also were attenuated by vitamin E. Such antiinflammatory effects of vitamin E were correlated with suppression of p38 MAPK and NFkappaB activation and were mimicked by an inhibition of either p38 MAPK (by SB203580) or NFkappaB (by decoy oligonucleotides). These results suggest that, in addition to the beneficial effects of providing direct antioxidant protection to neurons reported by others, vitamin E may provide neuroprotection in vivo through suppression of signaling events necessary for microglial activation.

Effects of amoxicillin on the expression of cytokines during experimental acute otitis media caused by non-typeable Haemophilus influenzae.

Antibiotics are frequently prescribed when a diagnosis of acute otitis media (AOM) is made in childhood, but the effects of antibiotics on host-parasite interactions in the middle ear are not well defined. A rat model and PCR techniques were used to explore host responses during amoxicillin treatment of AOM caused by non-typeable Haemophilus influenzae (NTHi). The 5 day course of amoxicillin initiated at the otomicroscopic peak of the infection eradicated the bacteria and induced significant changes in the expression of cytokines. Interleukin (IL)-6, tumour necrosis factor-alpha and IL-10 were upregulated by the treatment, and the downregulation was slower than during the natural course. Amoxicillin inhibited the upregulation of transforming growth factor-beta, whereas IL-1alpha expression remained unaffected by the treatment. By comparing inflammatory host responses during treated and untreated NTHi AOM, new targets for modification of the course, or more specified and individualized treatments, may evolve.

Preventive effects of isoflavones, genistein and daidzein, on estradiol-17beta-related endometrial carcinogenesis in mice.

The effects of isoflavones (genistein and daidzein) on endometrial carcinogenesis in mice were investigated in two experiments. In the short‐term experiment (2 weeks), single subcutaneous (s.c.) administration of genistein [1 mg/30 g body weight (b.w.)] significantly decreased the levels of estradiol‐l7β (E2) (5 ppm in diet)‐induced expression of c‐jun, interleukin‐lα (IL‐lα) and tumor necrosis factor‐a (TNF‐a) mRNAs in the uteri of ovariectomized mice (P<0.005, P<0.05 and P<0.01, respectively). Daidzein significantly inhibited E2‐induced expression of c‐fos and IL‐lα (P<0.01, P<0.01 respectively). In the long‐term experiment (30 weeks), 140 female ICR mice were given N‐methyl‐N‐nitrosourea‐containing solution (1 mg/100 g b.w.) and normal saline (as controls) into their left and right uterine corpora, respectively. They were divided into six groups; group 1 was given E2 (in diet) alone. Group 2 was given E2 and genistein (1 mg/30 g b.w., s.c., every four weeks). Group 3 was exposed to E2 and daidzein (1 mg/30 g b.w., s.c., every four weeks). Groups 4 and 5 respectively received genistein and daidzein, and were kept on the basal diet. Group 6 was kept on the basal diet and served as a control. At the termination of the experiment, incidences of endometrial adenocarcinoma and atypical endometrial hyperplasia of the group given E2 and genistein or daidzein were significantly lower than of the group with E2 alone (P<0.01 and P<0.05, respectively). It is suggested that both genistein and daidzein have an inhibitory effect on estrogen‐related endometrial carcinogenesis in mice, possibly by suppressing expression of estrogen‐induced estrogen‐related genes c‐fos and c‐jun, and internal cytokines IL‐lα and TNF‐α through a cytokine and estrogen receptor‐mediated pathway.