류마티스관절염 환자의 활막세포에서 Stat 단백의 발현에 관한 연구

심승철 ( Seung Cheol Shim ),이인홍 ( In Hong Lee ),정자헌 ( Ja Hun Jung ),김태환 ( Tae Hwan Kim ),전재범 ( Jae Bum Jun ),송강원 ( Kang Won Song ),배상철 ( Sang Cheol Bae ),유대현 ( Dae Hyun Yoo ),김성윤 ( Seong Yoon Kim ) 대한류마티스학회 2000 대한류마티스학회지 Vol.7 No.1

Objective: To characterize Stat activity in synovial tissue in rheumatoid arthritis (RA) in order to see if Stat molecule contributes to the pathogenesis of RA by regulatory expression of genes that play an important role in inflammation and tissue destruction. Methods: Synovial tissue were obtained immediately after operative excision. Immuno-histochemistry was done with the antibodies for Stat 3 and Stat 5. Cells were stimulated with interleukin 6 (IL-6) and soluble interleukin 6 receptor (sIL-6R) or steroid using chambered slide. In supershift experiment, cell extracts were incubated with 0.5ng of 32P-labelled double-stranded oligonucleotide probe. Samples were resolved on 4.5% polyacrylamide gels, which was transferred to polyvinylidene fluoride membranes. Anti-phosphotyrosine Stat 3 antibody was used for Western blotting. Results: Stat 3 was not shown on the synovial tissue section done by immuno-histochemistry. However, activated Stat 3 was expressed on cultured synovial cell stimulated with IL-6 and sIL-6R, and also with IL-6 and dexamethasone using chambered slide. In contrast to Stat 3, activated Stat 5 was expressed on the synovial tissue section, especially around blood vessel. Conclusion: Stat is activated in cultured synovial cells as shown in other immune associated cells, and IL-6 is the strong activator of Stat 3. Further analysis of the regulation of Stats in synovitis and the role of Stats in driving synovial inflammation will yield insight into the pathogenesis of RA and the development of novel therapeutic modality.

The role of local IL6/JAK2/STAT3 signaling in high glucose-induced podocyte hypertrophy

( Hyung Ah Jo ),( Joo-young Kim ),( Seung Hee Yang ),( Seung Seok Han ),( Kwon Wook Joo ),( Yon Su Kim ),( Dong Ki Kim ) 대한신장학회 2016 Kidney Research and Clinical Practice Vol.35 No.4

Background: Interleukin-6 (IL6) is an important regulator of cellular hypertrophy through the gp130/Janus kinase 2 (JAK2)/signal transducer and activator of transcription 3 (STAT3) pathway. We tested the hypothesis that IL6 and its downstream gp130/JAK2/STAT3 pathway participated in high glucose (HG)-induced podocyte hypertrophy. Methods: IL6 levels in the media and lysates of podocytes were measured by enzyme-linked immunosorbent assay. Western blots were performed to determine the protein expression levels of gp130/JAK2/STAT3 among podocytes cultured with normal glucose (NG), NG + mannitol, NG + recombinant IL6, HG, and HG + IL6- neutralizing antibodies (IL6NAb). Immunoprecipitation was examined to determine whether gp130 interacted with JAK2 in response to HG or IL6. Podocyte hypertrophy was verified using protein/cell counts and flow cytometry. Results: IL6 levels were significantly increased in the media and lysates of podocytes cultured in HG compared with the NG groups. The nuclear phospho-STAT3/ STAT3 ratio was increased by HG and NG + IL6 and was attenuated in the HG + IL6NAb groups, indicating that nuclear STAT3 was activated following JAK2 and cytosolic STAT3 activation in response to IL6 secreted by HG-stimulated podocytes. Immunoprecipitation showed increased phospho-JAK2 recruitment to gp130 in the HG and NG + IL6 groups, and the addition of IL6NAb in the HG group significantly abrogated these increases. Podocyte hypertrophy was significantly increased in the HG and NG + IL6 compared with the NG condition and was diminished by the addition of IL6NAbs to the HG group. Conclusion: IL6 might play a prominent role in the local activation of JAK2/STAT3 in podocyte hypertrophy under HG conditions. In vivo studies examining this pathway are warranted. Copyright ⓒ 2016. The Korean Society of Nephrology. Published by Elsevier. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

A STAT6 Inhibitor AS1517499 Reduces Preventive Effects of Apoptotic Cell Instillation on Bleomycin-Induced Lung Fibrosis by Suppressing PPARγ

Kim, Myeong-Joo,Lee, Ye-Ji,Yoon, Young-So,Lim, Jae H.,Park, Eun-Mi,Chong, Young H.,Kang, Jihee Lee S. KARGER AG 2018 CELLULAR PHYSIOLOGY AND BIOCHEMISTRY Vol.45 No.5

<P><B><I>Background/Aims:</I></B> The signal transducer and activator of transcription 6 (STAT6) transcription factor mediates PPARγ-regulated gene expression in macrophages. However, it remains largely unknown how proximal membrane signaling events initiated by apoptotic cell recognition upregulate PPARγ expression and activate the lung homeostatic program. <B><I>Methods:</I></B> The STAT6 inhibitor AS1517499 was used to determine the role of STAT6 in mediating PPARγ activity, anti-inflammatory effects, and anti-fibrotic effects induced by apoptotic cell instillation after bleomycin treatment into C57BL/6 mice. Bronchoalveolar lavage fluid, alveolar macrophages and lungs were harvested at days 2, 7, and 14 and then analyzed by real-time PCR, immunoblotting, ELISA, immunocytochemistry and immunohistochemistry assays. <B><I>Results:</I></B> Our data demonstrate that apoptotic cell instillation after bleomycin results in prolonged enhancement of STAT6 phosphorylation in alveolar macrophages and lung. Co-administration of the STAT6 inhibitor, AS1517499, reversed the enhanced PPARγ expression and activity induced by apoptotic cell instillation after bleomycin treatment. By reducing the expression of PPARγ target genes, including CD36, macrophage mannose receptor, and arginase 1, AS1517499 inhibited efferocytosis and restored pro-inflammatory cytokine expression, neutrophil recruitment, protein levels, hydroxyproline content, and expression of fibrosis markers, including type 1 collagen α2, fibronectin, and α-smooth muscle actin. STAT6 inhibition reversed the expression profile of hepatocyte growth factor and interleukin-10. <B><I>Conclusion:</I></B> These results indicate that prolonged STAT6 activation following one-time apoptotic cell instillation facilitates continuous PPARγ activation, resulting in the resolution of bleomycin-induced lung inflammation and fibrosis.</P>

STAT6 유전자의 G2964A 다형성을 이용한 한국인 알레르기 비염환자에서의 감수성에 대한 연구

이재훈,최태욱,이정헌,장철호,최상헌,김민수,김정중 대한이비인후과학회 2004 대한이비인후과학회지 두경부외과학 Vol.47 No.9

Background and Objectives:T helper-type 2 cytokines, such as IL-4 and IL-13, may play a central role in allergic diseases. The proteins known as signal transducers and activators of transcription 6 (STAT-6) are key transcription factors involved in both IL-4 and IL-13 mediated biological responses. Since a polymorphism of STAT6 G2964A has been found, we investigated Subjects and Method:Blood samples for genetic analysis were obtained from 229 individuals with allergic rhinitis and from 278 healthy subjects without atopic diseases. Polymerase chain reaction-based assay for the STAT6 G2964A variant was used for genotyping. Results:There were no diferences in the frequencies of the genotypes bn etweethe controls and patients (p>0.05). The frequencies of the STAT6 2964A allele were not statisticaly diferent between controls and alergic rhinitis patients (p> ). Conclusion:Our result sugests that the STAT6 G2964A polymorphism might not give susceptibility to the development of allergic rhinitis in Koreans.

Extracellular Signal-regulated Kinase Activation Is Required for Serine 727 Phosphorylation of STAT3 in Schwann Cells in vitro and in vivo

이현경,정준양,이상화,서수영,서덕준,박환태 대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

In the peripheral nerves, injury-induced cytokines and growth factors perform critical functions in the activation of both the MEK/ERK and JAK/STAT3 pathways. In this study, we determined that nerve injury-induced ERK activation was temporally correlated with STAT3 phosphorylation at the serine 727 residue. In cultured Schwann cells, we noted that ERK activation is required for the serine phosphorylation of STAT3 by neuropoietic cytokine interleukin-6 (IL-6). Serine phosphorylated STAT3 by IL-6 was transported into Schwann cell nuclei, thereby indicating that ERK may regulate the transcriptional activity of STAT3 via the induction of serine phosphorylation of STAT3. Neuregulin-1 (NRG) also induced the serine phosphorylation of STAT3 in an ERK-dependent fashion. In contrast with the IL-6 response, serine phosphorylated STAT3 induced by NRG was not detected in the nucleus, thus indicating the non-nuclear function of serine phosphorylated STAT3 in response to NRG. Finally, we determined that the inhibition of ERK prevented injury-induced serine phosphorylation of STAT3 in an ex-vivo explants culture of the sciatic nerves. Collectively, the results of this study show that ERK may be an upstream kinase for the serine phosphorylation of STAT3 induced by multiple stimuli in Schwann cells after peripheral nerve injury.

TRIM24-Mediated Acetylation of STAT6 Suppresses Th2-Induced Allergic Rhinitis

Yue Liyan,Jia Qiaojing,Dong Jinhui,Wang Jianxing,Ren Xiumin,Xu Ou 대한천식알레르기학회 2023 Allergy, Asthma & Immunology Research Vol.15 No.5

Purpose: Allergic rhinitis (AR) is a T helper type 2 (Th2)-mediated inflammatory disease. The E3 ligase tripartite motif-containing 24 (TRIM24) regulates the recruitment of acetyltransferase CREB-binding protein (CBP) to signal transducer and activator of transcription 6 (STAT6). CBP mediates the acetylation of STAT6 and decreases its activity. To date, the precise role of TRIM24 in AR has not been fully interpreted. Herein, our study aimed to explore the functions of TRIM24 in AR. Methods: The expression of TRIM24 in peripheral blood mononuclear cells (PBMCs) and CD4+ T cells from patients with AR was measured. TRIM24-conditional knockout mice with TRIM24 deficiency in CD4+ T cells were generated. Wide-type (WT) AR mice and TRIM24-conditional knockout AR mice were established. Then, AR symptoms and interleukin (IL)-4 levels were compared. Further, the proliferation, activation and polarization of CD4+ T cells from WT mice and TRIM24 knockout mice after stimulation were determined. The effects of TRIM24 deficiency on STAT6 activities were also evaluated. Results: Downregulated TRIM24 expression was detected in PBMCs and CD4+ T cells from patients with AR. TRIM24 conditional knockout mice had more sever AR symptoms with elevated IL-4 production. TRIM24-knockout CD4+ T cells had similar proliferation and activation when compared to WT CD4+ T cells, while they had enhanced Th2 polarization. TRIM24-knockout CD4+ T cells had decreased acetylation of STAT6 and enhanced STAT6 activities after IL-4 stimulation. The regulation of STAT6 activities by TRIM24 depended on TRIM24 N terminal RIGN domain and Lys383 acetylation site of STAT6. Conclusions: TRIM24 suppresses Th2-mediated AR by regulating the acetylation of STAT6.

Extracellular Signal-regulated Kinase Activation Is Required for Serine 727 Phosphorylation of STAT3 in Schwann Cells in vitro and in vivo

Lee, Hyun-Kyoung,Jung, Jun-Yang,Lee, Sang-Hwa,Seo, Su-Yeong,Suh, Duk-Joon,Park, Hwan-Tae The Korean Society of Pharmacology 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

In the peripheral nerves, injury-induced cytokines and growth factors perform critical functions in the activation of both the MEK/ERK and JAK/STAT3 pathways. In this study, we determined that nerve injury-induced ERK activation was temporally correlated with STAT3 phosphorylation at the serine 727 residue. In cultured Schwann cells, we noted that ERK activation is required for the serine phosphorylation of STAT3 by neuropoietic cytokine interleukin-6 (IL-6). Serine phosphorylated STAT3 by IL-6 was transported into Schwann cell nuclei, thereby indicating that ERK may regulate the transcriptional activity of STAT3 via the induction of serine phosphorylation of STAT3. Neuregulin-1 (NRG) also induced the serine phosphorylation of STAT3 in an ERK-dependent fashion. In contrast with the IL-6 response, serine phosphorylated STAT3 induced by NRG was not detected in the nucleus, thus indicating the non-nuclear function of serine phosphorylated STAT3 in response to NRG. Finally, we determined that the inhibition of ERK prevented injury-induced serine phosphorylation of STAT3 in an ex-vivo explants culture of the sciatic nerves. Collectively, the results of this study show that ERK may be an upstream kinase for the serine phosphorylation of STAT3 induced by multiple stimuli in Schwann cells after peripheral nerve injury.

IL6ST regulates liver tumorigenesis via the regulation of mitophagy

Hwan Ma,Jeong-Su Park,Feng Wang,Yeo-Jin Lee,Gyu-Rim Lee,Ekihiro Seki,Hwan-Soo Yoo,Yoon-Seok Roh 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.7

Hepatocellular carcinoma (HCC) is the sixth most commonly occurring cancer in the world and the third largest cause of cancer mortality. There is increasing evidence that the inflammatory process is inherently associated with many different cancer types, including HCC. Cytokines are released in response to a diverse range of cellular stresses, including carcinogen-induced injury, infection, and inflammation. A number of cytokines that are produced in the tumor microenvironment have an important role in cancer pathogenesis. Among them, there are IL-6 family cytokines that share the common receptor subunit IL6ST. IL6ST regulates cell survival, growth, and proliferation through the regulation of JAK-Stat3 and PI3K-mTORC1. Both downstream pathways have been linked with autophagy and mitochondrial function. Moreover, mitophagy contributes to metabolic dysfunction syndrome and chronic liver diseases such as NAFLD, NASH, and HCC. However, the mechanism of how IL6ST modulates hepatocyte mitophagy and HCC development remains unclear. IL6ST activated Stat3 and mTORC1 signaling in HCC, as evidenced by the controls phosphorylation of Stat3 (Tyr705), P70S6K(T389), EIF4E(S209), and RPS6(S235). Interestingly, IL6ST prevents mitochondrial stress and improves cell viability by inhibition of Stat3 and mTORC1-ULK1 mediated mitophagy and apoptosis. In genetically engineered mouse models of HCC (TAK1ΔHep), hepatocyte-specific deletion of IL6ST suppressed the multiplicity and maximum size of naturally occurring cancer. In conclusion, IL6ST governs parallel activation of carcinogenic STAT3 along with mTORC1 in the pathogenesis of HCC by regulation of mitophagy-dependent apoptosis and cancer cell survival.

Predominant Activation of JAK/STAT3 Pathway by Interleukin-6 Is Implicated in Hepatocarcinogenesis ¹ ²

Jung, In Hye,Choi, Jeffrey Hyun-Kyu,Chung, Yong-Yoon,Lim, Ga-Lam,Park, Young-Nyun,Park, Seung Woo Neoplasia Press 2015 Neoplasia Vol.17 No.7

<P>Chronic inflammation is an important process leading to tumorigenesis. Therefore, targeting and controlling inflammation can be a promising cancer therapy. Inflammation is often caused by a variety of inflammatory cytokine such as the interleukin (IL)-6, a pleiotrophic cytokine known to be involved in the tumorigenesis. In this study, an <I>in vivo</I> hepatic tumorigenesis model of zebrafish was generated to demonstrate a direct consequence of the human IL6 expression causing hepatocarcinogenesis. To do this, an elevated expression of the hIL6 gene was established to specifically target the zebrafish hepatocytes by transgenesis. Interestingly, the elevated hIL6 expression caused the chronic inflammation which results in a massive infiltration of inflammatory cells. This eventually resulted in the generation of various dysplastic lesions such as clear cell, small cell, and large cell changes, and also eosinophilic and basophilic foci of hepatocellular alteration. Hepatocellular carcinoma was then developed in the transgenic zebrafish. Molecular characterization revealed upregulation of the downstream components involved in the IL6-mediated signaling pathways, especially PI3K/Akt and JAK/STAT3 pathways. Further investigation indicated that PI3K was the most reactive to the infiltrated inflammatory cells and dysplasia with large cell change, whereas STAT3 was heavily activated in the region with dysplastic foci, suggesting that the JAK/STAT3 pathway was mainly implicated in the hepatic tumorigenesis in the current model. Our present study provides an <I>in vivo</I> evidence of the relationship between chronic inflammation and tumorigenesis and reinforces the pivotal role of IL6 in the inflammation-associated hepatocarcinogenesis.</P>

Extracellular Signal-regulated Kinase Activation Is Required for Serine 727 Phosphorylation of STAT3 in Schwann Cells in vitro and in vivo

Hyun Kyoung Lee,Junyang Jung,Sang Hwa Lee,Su-Yeong Seo,Duk Joon Suh,Hwan Tae Park 대한생리학회-대한약리학회 2009 The Korean Journal of Physiology & Pharmacology Vol.13 No.3

In the peripheral nerves, injury-induced cytokines and growth factors perform critical functions in the activation of both the MEK/ERK and JAK/STAT3 pathways. In this study, we determined that nerve injury-induced ERK activation was temporally correlated with STAT3 phosphorylation at the serine 727 residue. In cultured Schwann cells, we noted that ERK activation is required for the serine phosphorylation of STAT3 by neuropoietic cytokine interleukin-6 (IL-6). Serine phosphorylated STAT3 by IL-6 was transported into Schwann cell nuclei, thereby indicating that ERK may regulate the transcriptional activity of STAT3 via the induction of serine phosphorylation of STAT3. Neuregulin-1 (NRG) also induced the serine phosphorylation of STAT3 in an ERK-dependent fashion. In contrast with the IL-6 response, serine phosphorylated STAT3 induced by NRG was not detected in the nucleus, thus indicating the non-nuclear function of serine phosphorylated STAT3 in response to NRG. Finally, we determined that the inhibition of ERK prevented injury-induced serine phosphorylation of STAT3 in an ex-vivo explants culture of the sciatic nerves. Collectively, the results of this study show that ERK may be an upstream kinase for the serine phosphorylation of STAT3 induced by multiple stimuli in Schwann cells after peripheral nerve injury.