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Therapeutic effect of baicalin on experimental autoimmune encephalomyelitis is mediated by SOCS3 regulatory pathway.

Zhang Y, Li X, Ciric B, Ma CG, Gran B, Rostami A, Zhang GX - Sci Rep (2015)

Bottom Line: Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents.Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS).Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.

ABSTRACT
Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents. Baicalin (Ba) is a bioactive flavonoid compound derived from the root of Scutellaria baicalensis, an herb widely used in traditional medicine for the treatment of various inflammatory diseases. In this study, we investigate the effects and mechanism of action of Ba in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS). Ba reduced infiltration of immune cells into the CNS, inhibited expression of proinflammatory molecules and chemokines, and prevented Th1 and Th17 cell differentiation via STAT/NFκB signaling pathways. Further, we showed that SOCS3 induction is essential to the effects of Ba, given that the inhibitory effect of Ba on pathogenic Th17 responses was largely abolished when SOCS3 signaling was knocked down. Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.

No MeSH data available.


Related in: MedlinePlus

Role of Ba in Th1 cell differentiation and proliferation.Purified naïve CD4+ T cells were cultured with different concentrations of Ba under Th1 polarizing conditions and analyzed at 3 days of culture. (a) The percentage of Th1 cells in CD4+ T cells was analyzed by intracellular IFN-γ secretion. (b) IFN-γ production in culture supernatants was analyzed by ELISA. (c) IFN-γ mRNA levels were analyzed by real-time PCR. Intracellular levels of T-bet (d) and phosphorylation of STAT1 and STAT4 (e) of CD4+ T cells was analyzed using flow cytometry. (f) The above-mentioned differentiated Th1 cells were rested, washed and cultured for a second stimulation with IL-12 in the presence of Ba. Percentage of Th1 cells was analyzed by intracellular staining of IFN-γ. (g) Proliferation of pre-differentiated Th1 cell was measured by BrdU incorporation assay. The same cell preparations as in (f) were labeled with BrdU for 24 h of culture. Data are expressed as mean ± SEM (n = 5 each group). **P < 0.01; ***P < 0.001. One representative of three experiments is shown.
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f5: Role of Ba in Th1 cell differentiation and proliferation.Purified naïve CD4+ T cells were cultured with different concentrations of Ba under Th1 polarizing conditions and analyzed at 3 days of culture. (a) The percentage of Th1 cells in CD4+ T cells was analyzed by intracellular IFN-γ secretion. (b) IFN-γ production in culture supernatants was analyzed by ELISA. (c) IFN-γ mRNA levels were analyzed by real-time PCR. Intracellular levels of T-bet (d) and phosphorylation of STAT1 and STAT4 (e) of CD4+ T cells was analyzed using flow cytometry. (f) The above-mentioned differentiated Th1 cells were rested, washed and cultured for a second stimulation with IL-12 in the presence of Ba. Percentage of Th1 cells was analyzed by intracellular staining of IFN-γ. (g) Proliferation of pre-differentiated Th1 cell was measured by BrdU incorporation assay. The same cell preparations as in (f) were labeled with BrdU for 24 h of culture. Data are expressed as mean ± SEM (n = 5 each group). **P < 0.01; ***P < 0.001. One representative of three experiments is shown.

Mentions: Under Th1-polarizing conditions, approximately 60% of CD4+ cells were IFN-γ+ in the PBS-control group, and Ba treatment significantly inhibited Th1 cell differentiation in a dose-dependent manner (Fig. 5a). While the presence of Ba at a dose of 5 μg/ml during differentiation reduced Th1-polarized (IFN-γ-producing) CD4+ T cells by one half (25.4 ± 2.45% vs. 62.3 ± 4.75% in control, P < 0.01), Th1 cell differentiation was more effectively suppressed at higher doses of Ba, e.g., 10–20 μg/ml (6.36 ± 2.22% and 2.85 ± 1.14%, respectively, both P < 0.001). In agreement with this, IFN-γ production and expression were suppressed by Ba (Fig. 5b, c), which correlated with decreased T-bet expression (Fig. 5d), as well as decreased STAT1 and STAT4 phosphorylation (Fig. 5e). These results suggest that Ba hinders Th1 differentiation by inhibiting its key players, T-bet, STAT1 and STAT4. We also investigated the effect of Ba on already differentiated Th1 cells. Ba inhibited CD4+ IFNγ+ cells in a dose-dependent manner (Fig. 5f), and reduced their proliferation (Fig. 5g).


Therapeutic effect of baicalin on experimental autoimmune encephalomyelitis is mediated by SOCS3 regulatory pathway.

Zhang Y, Li X, Ciric B, Ma CG, Gran B, Rostami A, Zhang GX - Sci Rep (2015)

Role of Ba in Th1 cell differentiation and proliferation.Purified naïve CD4+ T cells were cultured with different concentrations of Ba under Th1 polarizing conditions and analyzed at 3 days of culture. (a) The percentage of Th1 cells in CD4+ T cells was analyzed by intracellular IFN-γ secretion. (b) IFN-γ production in culture supernatants was analyzed by ELISA. (c) IFN-γ mRNA levels were analyzed by real-time PCR. Intracellular levels of T-bet (d) and phosphorylation of STAT1 and STAT4 (e) of CD4+ T cells was analyzed using flow cytometry. (f) The above-mentioned differentiated Th1 cells were rested, washed and cultured for a second stimulation with IL-12 in the presence of Ba. Percentage of Th1 cells was analyzed by intracellular staining of IFN-γ. (g) Proliferation of pre-differentiated Th1 cell was measured by BrdU incorporation assay. The same cell preparations as in (f) were labeled with BrdU for 24 h of culture. Data are expressed as mean ± SEM (n = 5 each group). **P < 0.01; ***P < 0.001. One representative of three experiments is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC4663791&req=5

f5: Role of Ba in Th1 cell differentiation and proliferation.Purified naïve CD4+ T cells were cultured with different concentrations of Ba under Th1 polarizing conditions and analyzed at 3 days of culture. (a) The percentage of Th1 cells in CD4+ T cells was analyzed by intracellular IFN-γ secretion. (b) IFN-γ production in culture supernatants was analyzed by ELISA. (c) IFN-γ mRNA levels were analyzed by real-time PCR. Intracellular levels of T-bet (d) and phosphorylation of STAT1 and STAT4 (e) of CD4+ T cells was analyzed using flow cytometry. (f) The above-mentioned differentiated Th1 cells were rested, washed and cultured for a second stimulation with IL-12 in the presence of Ba. Percentage of Th1 cells was analyzed by intracellular staining of IFN-γ. (g) Proliferation of pre-differentiated Th1 cell was measured by BrdU incorporation assay. The same cell preparations as in (f) were labeled with BrdU for 24 h of culture. Data are expressed as mean ± SEM (n = 5 each group). **P < 0.01; ***P < 0.001. One representative of three experiments is shown.
Mentions: Under Th1-polarizing conditions, approximately 60% of CD4+ cells were IFN-γ+ in the PBS-control group, and Ba treatment significantly inhibited Th1 cell differentiation in a dose-dependent manner (Fig. 5a). While the presence of Ba at a dose of 5 μg/ml during differentiation reduced Th1-polarized (IFN-γ-producing) CD4+ T cells by one half (25.4 ± 2.45% vs. 62.3 ± 4.75% in control, P < 0.01), Th1 cell differentiation was more effectively suppressed at higher doses of Ba, e.g., 10–20 μg/ml (6.36 ± 2.22% and 2.85 ± 1.14%, respectively, both P < 0.001). In agreement with this, IFN-γ production and expression were suppressed by Ba (Fig. 5b, c), which correlated with decreased T-bet expression (Fig. 5d), as well as decreased STAT1 and STAT4 phosphorylation (Fig. 5e). These results suggest that Ba hinders Th1 differentiation by inhibiting its key players, T-bet, STAT1 and STAT4. We also investigated the effect of Ba on already differentiated Th1 cells. Ba inhibited CD4+ IFNγ+ cells in a dose-dependent manner (Fig. 5f), and reduced their proliferation (Fig. 5g).

Bottom Line: Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents.Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS).Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA.

ABSTRACT
Natural compounds derived from medicinal plants have long been considered a rich source of novel therapeutic agents. Baicalin (Ba) is a bioactive flavonoid compound derived from the root of Scutellaria baicalensis, an herb widely used in traditional medicine for the treatment of various inflammatory diseases. In this study, we investigate the effects and mechanism of action of Ba in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Ba treatment effectively ameliorated clinical disease severity in myelin oligodendrocyte glycoprotein (MOG)35-55 peptide-induced EAE, and reduced inflammation and demyelination of the central nervous system (CNS). Ba reduced infiltration of immune cells into the CNS, inhibited expression of proinflammatory molecules and chemokines, and prevented Th1 and Th17 cell differentiation via STAT/NFκB signaling pathways. Further, we showed that SOCS3 induction is essential to the effects of Ba, given that the inhibitory effect of Ba on pathogenic Th17 responses was largely abolished when SOCS3 signaling was knocked down. Taken together, our findings demonstrate that Ba has significant potential as a novel anti-inflammatory agent for therapy of autoimmune diseases such as MS.

No MeSH data available.


Related in: MedlinePlus