IL-6 induced proliferation and cytotoxic activity of CD8(+) T cells is elevated by SUMO2 overexpression.

T cells play an important role in adaptive immune responses that destroy pathogens or infected cells. Therefore, regulation of T cell activity is important in various diseases, such as autoimmune diseases, hypersensitivity, and cancer. The conjugation of small ubiquitin-related modifier (SUMO) is a post-translational protein modification that regulates activity, stability, and subcellular translocation of target proteins. In this study, CD8(+) T cells overexpressing SUMO2 showed greater proliferation and cytotoxic activity against tumor cells in the presence of IL-6 than wild-type CD8(+) T cells in vitro. These CD8(+) T cell functions were suppressed during treatment with MEK1 or PI3K-specific inhibitors. Therefore, our findings suggest that IL-6-derived signaling pathways, including the MEK1 and PI3K pathways, are upregulated by SUMO2 overexpression. However, transgenic expression of SUMO2 in T cells did not modulate Th1/2 balance. Collectively, our results showed that SUMO2-Tg promotes cytotoxic activity against tumor cells by increasing the proliferation and cytotoxicity of CD8(+) T cells.

SUMO2 overexpression enhances the generation and function of interleukin-17-producing CD8⁺ T cells in mice.

Small ubiquitin-like modifier (SUMO) 2 is a small protein that controls the activity and stability of other proteins by SUMOylation. In this study, T cell-specific SUMO2 overexpressing transgenic mice were generated to study the effect of SUMO2 on T lymphocytes. SUMO2 overexpression promoted differentiation of interleukin (IL)-17-producing CD8(+) T cells, and significantly suppressed the growth of EL4 tumor cells in vivo. Moreover, the tumor tissue from SUMO2-overexpressing mice had higher interferon (IFN)-γ and granzyme B mRNA levels. Although SUMO2 overexpression did not increase IFN-γ or granzyme B production in cytotoxic T lymphocytes, IL-12 treatment restored and increased IFN-γ secretion in IL-17-producing CD8(+) T cells. SUMO2 overexpression also increased gene expression of chemokines, CCL4, and CXCL10, which attract cytotoxic T lymphocytes to tumor tissues. Additionally, SUMO2-overexpressing T cells exhibited increased STAT3 phosphorylation, implying a SUMO2 target which up-regulates STAT3 activity governing IL-17A-producing CD8(+) T cell differentiation and antitumor immune responses.

Bcl-2 knockdown accelerates T cell receptor-triggered activation-induced cell death in jurkat T cells.

Cell death and survival are tightly controlled through the highly coordinated activation/inhibition of diverse signal transduction pathways to insure normal development and physiology. Imbalance between cell death and survival often leads to autoimmune diseases and cancer. Death receptors sense extracellular signals to induce caspase-mediated apoptosis. Acting upstream of CED-3 family proteases, such as caspase-3, Bcl-2 prevents apoptosis. Using short hairpin RNAs (shRNAs), we suppressed Bcl-2 expression in Jurkat T cells, and this increased TCR-triggered AICD and enhanced TNFR gene expression. Also, knockdown of Bcl-2 in Jurkat T cells suppressed the gene expression of FLIP, TNF receptor-associated factors 3 (TRAF3) and TRAF4. Furthermore, suppressed Bcl-2 expression increased caspase-3 and diminished nuclear factor kappa B (NF-κB) translocation.

Injection of phosphatidylcholine and deoxycholic acid regulates gene expression of lipolysis-related factors, pro-inflammatory cytokines, and hormones on mouse fat tissue.

Injection of phosphatidylcholine (PC) and deoxycholic acid (DA) preparation is widely used as an alternative to liposuction for the reduction of subcutaneous fat. Nevertheless, its physiological effects and mechanism of action are not yet fully understood. In this report, PC and deoxycholic acid (DA) were respectively injected into adipose tissue. PC decreased tissue mass on day 7, but DA did not. On the other hand, a decrement of DNA mass was observed only in DA-injected tissue on day 7. Both PC and DA reduced the mRNA expression of adipose tissue hormones, such as adiponectin, leptin, and resistin. In lipolysis-related gene expression profiles, PC increased hormone-sensitive lipase (HSL) transcription and decreased the expression other lipases, perilipin, and the lipogenic marker peroxisome proliferator-activated receptor-γ (PPARγ); DA treatment diminished them all, including HSL. Meanwhile, the gene expression of pro-inflammatory cytokines and a chemokine was greatly elevated in both PC-injected and DA-injected adipose tissue. Microscopic observation showed that PC induced lipolysis with mild PMN infiltration on day 7. However, DA treatment did not induce lipolysis but induced much amount of PMN infiltration. In conclusion, PC alone might induce lipolysis in adipose tissue, whereas DC alone might induce tissue damage.

Therapeutic potential of Lactobacillus plantarum CJLP133 for house-dust mite-induced dermatitis in NC/Nga mice.

Lactobacillus plantarum CJLP133 was isolated from Kimchi, a Korean fermented food, and its potential to improve mouse atopic dermatitis after onset was studied. Dermatitis was developed through house dust-mite extract application onto NC/Nga mice, and then CJLP133 feeding was started. CJLP133 suppressed dermatitis-like skin lesions and decreased high serum IgE levels through balancing between IL-4 and IFN-γ in serum. CJLP133 diminished skin thickening, mast cell accumulation into inflamed site, and lymph node enlargement. In lymph node cells, CJLP133 repressed secretion of T cell cytokines such as IFN-γ, IL-4, IL-5, and IL-10. However, CJLP133 decreased ratios of IFN-γ and IL-5 to IL-10 in lymph node cells, while it did not decrease ratios of IL-4 and IL-5 to IFN-γ. Conclusively, CJLP133 exhibited therapeutic potential for atopic dermatitis in mice through orderly increment of type 1 helper T cell activation and regulatory T cell activation. These results suggest that CJLP133 could treat human atopic dermatitis.

Erratum to ''Characterization of the regulatory roles of the SUMO.

BACKGROUND: Type 1 diabetes is a multi-factorial autoimmune disease that results from the destruction of insulin-producing ß cells of the pancreas; both genetic and environmental factors are thought to contribute to its development. Recently, a novel gene encoding small ubiquitin-like modifier protein 4 (SUMO4) was cloned and a single nucleotide substitution (M55V) was found to be strongly associated with type 1 diabetes. SUMO4 was shown to interact with IκBα and inhibit NFκB transcriptional activity. The M55V substitution of SUMO4 may affect its ability to modify IκBα by sumoylation, and so lead to activation of NFκB and transcription of genes implicated in the development of type 1 diabetes. However, the effects of sumoylation on immune cells are poorly understood. METHODS: Human SUMO1, 2, 3, 4 and mouse SUMO2 (mSUMO2) were cloned and overexpressed in T and B cells using retroviral transduction. We then investigated whether SUMO overexpression affected their functions in vitro. To study the function of mSUMO2 in vivo, we made transgenic mice overexpressing mSUMO2 in T cells and pancreatic ß cells and compared them with transgenic mice expressing a super-repressor of NFκB (a dominant negative form of NFκB, IκBαΔN) in T cells. Diabetes was induced in the two groups of mice by i.p. injection of streptozotocin. RESULTS: Human SUMO1, 2, 3, 4 and mSUMO2 were all found to negatively regulate the transcriptional activity of T and B cells. Supporting this idea, mSUMO2 overexpression in T cells suppressed the production of both Th1 and Th2 cytokines unlike T cells from the IκBαΔN mice. However, transgenic mice overexpressing mSUMO2 had the same susceptibility to diabetes as wild type whereas the mice overexpressing IκBαΔN Tg were completely protected against diabetes. CONCLUSION: These results indicate that at least in T cells, whereas NFκB has pro-apoptotic activity, mSUMO2 plays a more complex role in the development of autoimmune diabetes. The relative influence of NFκB and sumoylation on the development of autoimmune diabetes in vivo may vary depending on the developmental stage and cell type.

Characterization of the regulatory roles of the SUMO.

BACKGROUND: Type 1 diabetes is a multi-factorial autoimmune disease that results from the destruction of insulin-producing ß cells of the pancreas; both genetic and environmental factors are thought to contribute to its development. Recently, a novel gene encoding small ubiquitin-like modifier protein 4 (SUMO4) was cloned and a single nucleotide substitution (M55V) was found to be strongly associated with type 1 diabetes. SUMO4 was shown to interact with IκBα and inhibit NFκB transcriptional activity. The M55V substitution of SUMO4 may affect its ability to modify IκBα by sumoylation, and so lead to activation of NFκB and transcription of genes implicated in the development of type 1 diabetes. However, the effects of sumoylation on immune cells are poorly understood. METHODS: Human SUMO1, 2, 3, 4 and mouse SUMO2 (mSUMO2) were cloned and overexpressed in dendritic, T and B cells using retroviral transduction. We then investigated whether SUMO overexpression affected their functions in vitro. To study the function of mSUMO2 in vivo, we made transgenic mice overexpressing mSUMO2 in T cells and pancreatic ß cells and compared them with transgenic mice expressing a super-repressor of NFκB (a dominant negative form of NFκB, IκBαΔN) in T cells. Diabetes was induced in the two groups of mice by i.p. injection of streptozotocin. RESULTS: Human SUMO1, 2, 3, 4 and mSUMO2 were all found to negatively regulate the transcriptional activity of T, B and dendritic cells. Although mSUMO2 overexpression in dendritic cells did not alter the expression of major histocompatibility complex class II proteins or B7, IL-1, IL-6 and IL-7, IL-12 expression decreased, switching Th1-directed immune responses into Th2 responses. Unlike T cells from the IκBαΔN mice, mSUMO2 overexpression in T cells suppressed the production of both Th1 and Th2 cytokines. Whereas the mice overexpressing IκBαΔN were completely protected against diabetes, those expressing mSUMO2 had the same susceptibility to diabetes as wild type. CONCLUSION: These results indicate that at least in T cells, whereas NFκB has pro-apoptotic activity, mSUMO2 plays a more complex role in the development of autoimmune diabetes. The relative influence of NFκB and sumoylation on the development of autoimmune diabetes in vivo may vary depending on the developmental stage and cell type.

Immunomodulatory activity of Lactobacillus strains isolated from fermented vegetables and infant stool.

Four Lactobacillus strains - Lactobacillus plantarum CJLP133, L. plantarum CJLP243, L. plantarum CJNR26, and Lactobacillus gasseri CJMF3 - were isolated from Korean fermented food or healthy infant feces, and their capacity to modulate cellular and humoral immune responses was studied. Feeding of the tested lactobacilli for 8 weeks did not alter the weight of and cell numbers in the spleen of mice. However, CJLP133 and CJLP243 strains increased the T lymphocyte population in the spleen of mice, while CJNR26 and CJMF3 increased the B lymphocyte population. In splenocytes treated with concanavalin A, ingestion of CJLP133 and CJLP243 promoted T lymphocyte proliferation and secretion of T cell cytokines, whereas feeding of the CJNR26 and CJMF3 strains enhanced B lymphocyte proliferation in splenocytes treated with lipopolysaccharide and plaque formation. These results suggest that CJLP133 and CJLP243 have immunostimulating activity through the enhancement of T cell activation, while CJNR26 and CJMF3 exhibit immunopotentiation through the increment of B cell activation.

Modulation of Th1/Th2 balance by Lactobacillus strains isolated from Kimchi via stimulation of macrophage cell line J774A.1 in vitro.

UNLABELLED: Lactobacilli isolated from Kimchi, a Korean traditional food, were tested for their capacity to modulate the T helper (Th) 1/Th2 balance. Ovalbumin (OVA)-sensitized mouse splenocytes were cultured with 26 strains of lactobacilli; the highest IL-12 induction and lowest IL-4 production were then observed in 4 strains, including Lactobacillus plantarum CJLP55, CJLP56, CJLP133, and CJLP136. These strains produced a larger amount of IL-12, which enhances differentiation and activation of Th1 cells, in macrophage cell-lines more than positive control strains L. casei KCTC 3109(T) and L. rhamnosus GG, although they also induced production of IL-10, which is a suppressor of IL-12. Indeed, CJLP133-stimulated macrophages induced production of more Th1 cytokine IFN-γ and less Th2 cytokine IL-4 than KCTC 3109(T) and GG in co-cultivation with T cells. These findings suggest that lactobacilli from Kimchi may modulate the Th1/Th2 balance via macrophage activation in the hypersensitive reaction caused by Th2 cells. PRACTICAL APPLICATION: Allergic reactions including asthma and atopy are caused by predominance of Th2 response over Th1 response. Lactobacilli isolated from fermented foods such as yogurt, cheese, and Kimchi showed health-promoting activities. The present study indicated that several lactobacilli strains from Kimchi may reduce allergic reactions through macrophage-mediated induction of Th1 response.

Forced expression of programmed death-1 gene on T cell decreased the incidence of type 1 diabetes.

Programmed death-1 (PD-1) is a co-inhibitory receptor of the CD28/CTLA-4 family which is expressed on activated T cells and inhibits T cell activation after binding to PD-1 ligands. In animal models, PD-1 regulates autoimmune disease and induces tolerance in pancreas. In this study the effects of PD-1 on type 1 diabetes were examined using PD-1 transgenic mice (Tg). The incidence of autoimmune diabetes induced by multiple low dose of streptozotocin (STZ) was reduced in PD-1 Tg mice. Although the expression of CTLA-4, PD-1 and FoxP3, which are inhibitory molecules of activated T cells, is reduced only on STZ injected wild type (WT) mice, CD4, CD8 and regulatory T cell populations were not changed in all experimental groups. When splenocytes were re-stimulated in ex vivo, the production of IL-2 and IFN-γ and the T cell proliferation were increased in all STZ injected mice, but the increment rate was less in PD-1 Tg groups. Interestingly, macrophages were observed in splenocytes of STZ injected PD-1 Tg at somewhat lower level than macrophage in diabetic wild type mice. In this research, we found out that total numbers of T cell in the experimental groups are not changed, but T cell function is changed, and FoxP3 expression is decreased in pancreas and spleen of diabetes-induced groups. Macrophage frequency might also affects on type 1 diabetes. Although more experimental evidence needs to be provided, these results suggest that ligation of PD-1 and PD-L1/2 may have an effect on macrophages as well as does T cells.

The new diterpene isodojaponin D inhibited LPS-induced microglial activation through NF-kappaB and MAPK signaling pathways.

Neuroinflammation with prolonged microglial activation leads to increased levels of pro-inflammatory mediators and subsequently contributes to neuronal dysfunction and neuronal loss. Therefore, pharmacological suppression of neuroinflammation would theoretically slow the progression of neurodegenerative disease. In this study, we investigated the anti-inflammatory effects and possible mechanisms of isodojaponin D (19-hydroxy-1alpha,6-diacetoxy-6,7-seco-ent-kaur-16-en-15-one-7,20-olide), a new diterpene isolated from Isodon japonicus against lipopolysaccharide(LPS)-induced microglial activation in BV2 cells. Results from RT-PCR and Western blot showed that pretreatment with isodojaponin D (5 and 10 microg/ml) prior to treatment with LPS (1 microg/ml) significantly decreased LPS-induced production of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) in a dose-dependent manner. In addition, LPS-induced pro-inflammatory cytokines, including IL-1beta, IL-6, and TNF-alpha, were also decreased by pretreatment with isodojaponin D. This effect was accompanied by a decrease in translocations of Nuclear Factor-KappaB (NF-kappaB) p50 and p65 from the cytoplasm to the nucleus and by a decrease in I kappaB (IkappaB) degradation. In addition, pretreatment with isodojaponin D significantly attenuated LPS-induced mitogen-activated protein kinase (MAPK) activation. Taken together, these results suggest that isodojaponin D suppressed LPS-induced microglial activation and production of pro-inflammatory mediators by inhibition of the NF-kappaB signaling pathway and phosphorylation of MAPKs. These results suggest that isodojaponin D could play a beneficial role in treatment of neurodegenerative disease.

Inhibition of coagulation activation and inflammation by a novel Factor Xa inhibitor synthesized from the earthworm Eisenia andrei.

We have cloned an earthworm-derived Factor Xa (FXa) inhibitor, with an excellent inhibitory specificity from the midgut of the Eisenia andrei. We designate this inhibitor eisenstasin. An eisenstasin-derived small peptide (ESP) was synthesized and we examined whether ESP played an essential role in FXa inhibition. Compared to antistasin-derived small peptides (ASP) originating from leech, ESP primarily exhibited a high level of FXa inhibition in chromogenic peptide substrate assays and revealed an approximately 2-fold greater inhibition of FXa cleavage of a target protein than ASP. This suggests that ESP could be an effective anti-coagulant that targets FXa during the propagation step of coagulation. ESP also inhibited proteinase-activated receptor 2-mediated FXa activation, which may trigger endothelial inflammation. Endothelial nitric oxide (NO) was significantly reduced by ESP (p<0.0001), indicating that protease-activated receptor-2 (PAR-2) was effectively inactivated. We also found that ESP reduced the expressions of pro-inflammatory cytokines (IL-1alpha, IL-1beta, IL-8, IL-16, MCP-1, MIP-1alpha and MIP-1beta) by cultured cells treated with both ESP and FXa. Our results provide the first evidence that ESP might interrupt coagulation cascades by inhibiting FXa, and thereby may effectively control the bidirectional alternation between coagulation and inflammation.

Therapeutic advantages of medicinal herbs fermented with Lactobacillus plantarum, in topical application and its activities on atopic dermatitis.

The use of herbal medicines in the therapeutic treatment of atopic dermatitis (AD) has been suggested recently. The present study examined whether selected herbal extracts fermented in Lactobacillus plantarum (FHE) possessed anti-AD properties. In addition, the study assessed the increased bioavailability of these herbal extracts both in vitro and in vivo. The data from these experiments revealed that FHE inhibited the proliferation of splenic T and B cells in a dose-dependent manner, when activated with their mitogens. Moreover, the expression of Th1/Th2 mRNA cytokines (IL-2, IL-4, IL-5, IL-13) from mouse splenocytes was inhibited severely as was cyclosporine A. Furthermore, the release of beta-hexosaminidase in RBL-2H3 mast cells was suppressed significantly. FHE also reduced the plasma level of IgE in dust mite extract-induced AD-like NC/Nga mice. More dramatic results were found in the histological changes, which were observed by hematoxylin-eosin and toluidine blue staining, as well as in the macroscopic features on dorsal lesions of AD-like NC/Nga mice. In conclusion, the results presented in this study suggest that FHE may have therapeutic advantages for the treatment of AD due to its increased immune-suppressive and increased absorptive effects, which were fortified by L. plantarum fermentation.

Interferon signal transduction of biphenyl dimethyl dicarboxylate/amantadine and anti-HBV activity in HepG2 2.2.15.

Biphenyl dimethyl dicarboxylate (DDB) is a hepatoprotectant, which is used as an adjuvant agent in a treatment for chronic hepatitis. Amantadine is an antiviral agent, which is utilized primarily in the treatment of influenza, but also, occasionally in the treatment of hepatitis C. In a previous study, we reported that DDB, coupled with amantadine, would exert an anti-HBV effect, via the induction of interferon-inducible gene expression in the HepG2 2.2.15 cell line. The primary objective of the present study was to determine whether or not DDB and/or amantadine exhibit anti-HBV properties, and what mechanisms of action might be involved in such properties. In our study, we were able to determine that DDB stimulates Jak/Stat signaling, and induces the expression of interferon alpha (IFN-alpha) stimulated genes, most notably 6-16 and ISG12. In addition, the antiviral effectors induced by IFN-alpha, PKR, OAS, and MxA, were regulated in the presence of DDB at its optimal concentration (250 microg/mL), to a degree commensurate with the degree of induction associated with the IFN-alpha treated group. Finally, we determined that the replication of pregenomic RNA and HBeAg was inhibited by DDB treatment, and this inhibition was maximized when coupled with the administration of amantadine (25 microg/mL). In conclusion, the results of this study demonstrated clearly that DDB, as well as the combination of DDB/amantadine, directly inhibited IFN-alpha signaling-mediated replication of HBV in infected hepatocytes, and thus may represent a novel treatment for chronic hepatitis B, which would be characterized principally by its improved safety over other treatment strategies.

Reciprocal activity of ginsenosides in the production of proinflammatory repertoire, and their potential roles in neuroprotection in vivo.

Ginsenosides, the active compounds inherent to most Ginseng species [e. g., Panax ginseng (Araliaceae)], have recently been the focus of increased attention, due to both their purported CNS, antineoplastic and immunomodulatory effects, and their ability to stimulate phagocytosis. In this study, we attempted to determine the effects of ginsenosides Rb1 and Rg1 in a rat model, with specific emphasis on nitric oxide and cytokines, which have been implicated in chronic brain inflammation. We discovered that Rb1 and Rg1 exert opposite effects in a dose-dependent manner (50-250 microg/mL). Whereas Rg1 stimulated nitric oxide and proinflammatory cytokines (IL-1beta, IL-6, and TNF-alpha), Rb1 exerted a significant inhibitory effect on this proinflammatory repertoire. In addition, the genetic expression of bcl-2 and bax, both of which have been implicated in apoptosis, was regulated by treatment with Rb1 and Rg1, at a concentration of 250 microg/mL. Moreover, when combined treatment with equal doses of Rb1 and Rg1 was given, Rb1 significantly counteracted the stimulatory effects of Rg1, as evidenced by an NO assay. This effect persisted stably for 72 h. In conclusion, neurodegenerative diseases such as Alzheimer's disease, which is caused primarily by cell death due to chronic inflammation and cell stress, might be controlled by proper doses of non-toxic, natural Rg1 and Rb1.

Potential role of ursodeoxycholic acid in suppression of nuclear factor kappa B in microglial cell line (BV-2).

Expression of the NF-kappaB-dependent genes responsible for inflammation, such as TNF-alpha, IL-1beta, and nitric oxide synthase (NOS), contributes to chronic inflammation which is a major cause of neurodegenerative diseases (i.e. Alzheimer's disease). Although NF-kappaB plays a biphasic role in different cells like neurons and microglia, controlling the activation of NF-kappaB is important for its negative feedback in either activation or inactivation. In this study, we found that ursodeoxycholic acid (UDCA) inhibited IkappaB alpha degradation to block expression of the NF-kappaB-dependent genes in microglia when activated by beta-amyloid peptide (A beta). We also showed that when microglia is activated by A beta42, the expression of A20 is suppressed. These findings place A20 in the category of "protective" genes, protecting cells from pro-inflammatory repertoires induced in response to inflammatory stimuli in activated microglia via NF-kappaB activation. In light of the gene and proteins for NF-kappaB-dependent gene and inactivator for NF-kappaB (IkappaB alpha), the observations now reported suggest that UDCA plays a role in supporting the attenuation of the production of pro-inflammatory cytokines and NO via inactivation of NF-kappaB. Moreover, an NF-kappaB inhibitor such as A20 can collaborate and at least enhance the anti-inflammatory effect in microglia, thus giving a potent benefit for the treatment of neurodegenerative diseases such as AD.

Isoflavones extracted from Sophorae fructus upregulate IGF-I and TGF-beta and inhibit osteoclastogenesis in rat bone marrow cells.

Isoflavones have been a central subject in research on the natural phytoestrogens found in Leguminosae. Their effects on bone formation and remodeling are important in that they can act like estrogen by binding on estrogen receptors on the target cell surface. We, therefore, believed that isoflavones may help in the treatment of patients with estrogen deficiency disease such as estrogen replacement therapy (ERT) for osteoporosis. As commonly known, osteoporosis is one of the hormonal deficiency diseases, especially in menopausal women. When estrogen is no longer produced in the body a remarkable bone remodeling process occurs, and the associated events are regulated by growth factors in the osteoblast lineage. In the present study, we investigated whether isoflavones (Isocal) extracted from Sophorae fructus affect the growth factors IGF-I and TGF-beta that have been known to be related with bone formation. In the study, we found that the active control (PIII) effectively enhanced the level of nitric oxide (NO) and growth factors, and thereby inhibited osteoclastogenesis. The most efficient concentration was 10(-8)% within five days, whereas the comparative control (soybean isoflavone) was not as effective even at a lower concentration. In conclusion, the products which contain enriched glucosidic isoflavone and nutrient supplements such as shark cartilage and calcium can be used for osteoporosis therapy by enhancing the production of IGF-I and TGF-beta. Furthermore, the NO produced through endothelial constitutive NO synthase (ecNOS) may play a role in inhibiting bone reabsorption.

Ursodeoxycholic acid inhibits pro-inflammatory repertoires, IL-1 beta and nitric oxide in rat microglia.

Ursodeoxycholic acid (UDCA) is a non-toxic, hydrophilic bile acid in widespread clinical use mainly for acute and chronic liver disease. Recently, treatment with UDCA in hepatic graft-versus-host disease has been given in immunosuppressive therapy for improvement of the biochemical markers of cholestasis. Moreover, it has been reported that UDCA possesses immunomodulatory effects by the suppression of cytokine production. In the present study, we hypothesized that UDCA may inhibit the production of the pro-inflammatory cytokine, IL-1beta, and nitric oxide (NO) in microglia. In the study, we found that 100 microg/mL UDCA effectively inhibited these two pro-inflammatory factors at 24 h and 48 h, compared to the Abeta42-pretreated groups. These results were compared with the LPS+UDCA group to confirm the UDCA effect. As microglia can be activated by several stimulants, such as Abeta42, in Alzheimers brain and can release those inflammatory factors, the ability to inhibit or at least decrease the production of IL-1beta and NO in Alzheimers disease (AD) is essential. Using RT-PCR, ELISA and the Griess Reagent System, we therefore found that UDCA in Abeta42 pre-treated cultures played a significant role in suppressing the expression or the production of IL-1beta and NO. Similarly, lipopolysaccharide (LPS) did not activate microglia in the presence of UDCA. Moreover, we found that UDCA exhibits a prolonged effect on microglial cells (up to 48 h), which suggests that UDCA may play an important role in chronic cell damage due to this long effect. These results further imply that UDCA could be an important cue in suppressing the microglial activation stimulated by massive Aâ peptides in the AD progressing brain.