Deletion of Chitinase-3-like 1 accelerates stroke development through enhancement of Neuroinflammation by STAT6-dependent M2 microglial inactivation in Chitinase-3-like 1 knockout mice

Im, Jun Hyung,Yeo, In Jun,Park, Pil Hoon,Choi, Dong Young,Han, Sang-Bae,Yun, Jaesuk,Hong, Jin Tae Elsevier 2020 Experimental neurology Vol.323 No.-

<P><B>Abstract</B></P> <P>Chitinase 3-like 1 (Chi3L1) plays a major role in the pathogenesis of inflammatory diseases. We investigated the effect of Chi3L1 knockout on stroke development. Ischemia/reperfusion was induced by middle cerebral artery occlusion (MCAO) in Chi3L1 knockout and wildtype mice. Significantly increased infarct volume and decreased neurological deficit scores at 24 h after ischemia/reperfusion were found in Chi3L1 knockout mice compared to wildtype mice. Moreover, ischemic neuronal cell death was increased in Chi3L1 knockout mice through increased oxidative stress and release of IL-6 and IL-1β but IL-10 and IL-4 were reduced. Furthermore, expression of inflammation-related proteins (iNOS, COX-2, Iba-1, and GFAP) was significantly increased in Chi3L1 knockout mice compared to wildtype. In microglia isolated from MCAO-injured Chi3L1 knockout mice, expression of M1 markers (iNOS, CD86, IL-1β, and IL-6) was increased and M2 markers (Arg1, Mrc1, IL-10, and IL-4Ra) was decreased. In BV-2 cells, knockdown of Chi3L1 increased TNF-α- and INF-γ-induced expression of iNOS, COX-2, and Iba-1, but decreased the expression of Arg1, MRC1, and IL-4 receptor-alpha (IL-4Rα). Expression of IL-4Rα, an important factor of M2 polarization, and its downstream signals p-JAK1, p-JAK3, and p-STAT6, was much reduced in the knockout mice. Additionally, in BV-2 cells, knockdown of Chi3L1 by siRNA Chi3L1 decreased rhTNF-α- and INF-γ-induced expression of IL-4Rα, p-JAK1, p-JAK3, and p-STAT6. Furthermore, treatment with AS1517499 abolished Chi3L1 knockdown-induced reduced IL-4Rα and Arg1 but not CD86 expression. Our results indicate that deletion of Chi3L1 accelerates stroke development through enhancement of neuroinflammation by markedly decreasing STAT6-dependent M2 macrophage polarization.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Chi3L1 is important for IL-4Rα expression and phosphorylation of STAT6, affecting micorglial M2 polarization. </LI> <LI> Knockdown of Chi3L1 decrease IL-4Rα, p-JAK1, p-JAK3, and p-STAT6 expression level which blocking microglial M2 polarization. </LI> <LI> Absence of Chi3L1 accelerates stroke development through STAT6 dependent M2 microglia inactivation. </LI> </UL> </P>

IL-6 is produced by adipose-derived stromal cells and promotes osteogenesis

Huh, J.E.,Lee, S.Y. Elsevier Biomedical Press 2013 Biochimica et biophysica acta, Molecular cell rese Vol.1833 No.12

Although Toll-like receptors (TLRs) have been implicated in the regulation of stem cell functions, their role in osteogenic differentiation of adipose-derived stromal cells (ASCs) has not been reported. We found that ASCs express a restricted subset of TLRs, including TLR1-TLR5, and that TLR agonists such as Pam3CSK4 (TLR½ agonist), polyinosinic:polycytidylic acid (TLR3 agonist), lipopolysaccharide (TLR4 agonist), and flagellin (TLR5 agonist), but not R848 (TLR7/8 agonist), consistently induced osteogenic differentiation in murine-derived ASCs, which coincided with the TLR expression pattern of ASCs. Cytokine expression profiles induced by TLR agonists and results from subsequent functional assays indicated that interleukin-6 (IL-6) together with soluble IL-6 receptor (sIL-6R) enhanced osteogenic differentiation of ASCs by activating STAT3. Small interfering RNA (siRNA)-mediated STAT3-silencing blunted osteogenesis and the expression of osteogenic markers, whereas STAT3 overexpression resulted in an increase in osteogenesis. Consistently, STAT3 inhibitor treatment reduced osteogenesis, STAT3 phosphorylation, and expression of osteogenic markers including osterix. Chromatin immunoprecipitation (ChIP) assays indicated that STAT3 binding to the STAT3-binding sites on the osterix promoter increased during IL-6-stimulated osteogenesis. Our results thus establish TLRs as novel regulators of ASCs which signal through IL-6/STAT3 pathway and induce osterix expression as a part of the osteogenesis.

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.

<i>In vitro</i> inhibitory effects of cirsiliol on IL-6-induced STAT3 activation through anti-inflammatory activity

Lim, Hyung Jin,Jang, Hyun Jae,Bak, Seon Gyeong,Lee, Soyoung,Lee, Seung Woong,Lee, Kang Min,Lee, Seung-Jae,Rho, Mun-Chual Pergamon Press 2019 Bioorganic & medicinal chemistry letters Vol.29 No.13

<P><B>Abstract</B></P> <P>Many studies have identified and described various medicinal effects of cirsiliol. Here, we investigated the signaling pathway involved in the anti-inflammatory effects of cirsiliol on IL-6-induced activity. Cirsiliol showed no cytotoxicity and inhibited pSTAT3-induced luciferase activity. At the molecular level, cirsiliol suppressed the expression of IL-6-induced inflammatory marker genes such as CRP, IL-1β, ICAM-1 and SOCS3, IL-6-induced activation of Jak2, gp130, STAT3 and ERK and nuclear translocation of STAT3, as measured by PCR, immunofluorescence staining and western blot analysis. However, the interaction between IL-6 and its receptor was not affected by cirsiliol treatment. These results indicate that cirsiliol attenuates IL-6-induced cellular signaling by regulating Jak2 phosphorylation. Therefore, cirsiliol could be a therapeutic agent for IL-6-related inflammatory diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We investigated the inhibitory effects of cirsiliol on IL-6/STAT3 activation. </LI> <LI> Cirsiliol inhibited the expression of p-JAK2 and p-ERK but not the interaction of IL-6 and IL-6R. </LI> <LI> Cirsiliol could serve as a natural immunoregulatory compound. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis of benzoxazole derivatives as interleukin-6 antagonists

Kim, Darong,Won, Hee Yeon,Hwang, Eun Sook,Kim, Young-Kook,Choo, Hea-Young Park Pergamon 2017 Bioorganic & medicinal chemistry Vol.25 No.12

<P><B>Abstract</B></P> <P>A growing number of studies have demonstrated that interleukin (IL)-6 plays pathological roles in the development of chronic inflammatory disease and autoimmune disease by activating innate immune cells and by stimulating adaptive inflammatory T cells. So, suppression of IL-6 function may be beneficial for prevention and treatment of chronic inflammatory disease. This study reports that a series of synthetic derivatives of benzoxazole have suppressive effects on IL-6-mediated signaling. Among 16 synthetic derivatives of benzoxazole, the compounds <B>4</B>, <B>6</B>, <B>11</B>, <B>15</B>, <B>17</B>, and <B>19</B> showed a strong suppressive activity against IL-6-induced phosphorylation of signal transducer and activator of transcription (STAT) 3 by 80–90%. While the cell viability was strongly decreased by compounds <B>11</B>, <B>17</B>, <B>19</B>, the compounds <B>4</B>, <B>6</B>, and <B>15</B> revealed less cytotoxicity. We then examined the effects of the compounds on inflammatory cytokine production by CD4+ T cells. CD4+ T cells were induced to differentiate into interferon (IFN)-γ-, IL-17-, or IL-4-producing effector T cells in the presence of either the compound <B>4</B> or the compound <B>7</B>. While the inactive compound <B>7</B> had no significant effect on the cytokine production by effector T cells, the active compound <B>4</B> strongly suppressed the production of inflammatory cytokines IFN-γ and IL-17, and also inhibited allergic inflammatory cytokines IL-4, IL-5, and IL-13 produced by effector Th2 cells. These results suggest that a benzoxazole derivative, compound <B>4</B> effectively suppresses IL-6-STAT3 signaling and inflammatory cytokine production by T cells and provides a beneficial effect for treating chronic inflammatory and autoimmune disease.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Novel benzoxazole compounds effectively suppress IL-6-STAT3 signaling. </LI> <LI> The compound <B>4</B> strongly suppressed the production of IFN-γ and IL-17. </LI> <LI> Also <B>4</B> inhibited IL-4, IL-5, and IL-13 produced by effector Th2 cells. </LI> <LI> Therefore <B>4</B> could be used for treating chronic inflammatory and autoimmune disease. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

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>

STAT3-inhibitory activity of sesquiterpenoids and diterpenoids from <i>Curcuma phaeocaulis</i>

Jang, Hyun-Jae,Lim, Hyung-Jin,Park, Eun-Jae,Lee, Seung-Jae,Lee, Soyoung,Lee, Seung Woong,Rho, Mun-Chual Elsevier 2019 Bioorganic chemistry Vol.93 No.-

<P><B>Abstract</B></P> <P>Three new sesquiterpenoids (compounds <B>4</B>, <B>5</B>, and <B>26</B>), along with 23 known sesquiterpenoids (compounds <B>1</B>–<B>3</B> and <B>6</B>–<B>25</B>) and two diterpenoids (compounds <B>27</B> and <B>28</B>), were obtained from <I>Curcuma phaeocaulis</I>, and their chemical structures were determined through nuclear magnetic resonance (NMR), circular dichroism (CD), and high-resolution electrospray ionization (HRESIMS) spectroscopic data, which were compared to the data from previous studies. All isolates were tested for inhibitory activity against interleukin (IL)-6-stimulated STAT3 expression using a luciferase reporter assay, and curzerenone (<B>21</B>) and 8-<I>epi</I>-galanolactone (<B>28</B>) displayed promising signal transducer and activator of transcription (STAT3)-inhibitory activities with IC<SUB>50</SUB> values of 4.8 and 4.1 μM, respectively. In addition, these candidates significantly suppressed the mRNA expression levels of the proinflammatory genes IL-1β and C-reactive protein (CRP) via blockade of the IL-6-activated Janus kinase 2 (JAK2)/STAT3 and ERK-MAPK signaling pathways. These results suggest that curzerenone (<B>21</B>) and 8-<I>epi</I>-galanolactone (<B>28</B>) may be potential candidates for ameliorating severe inflammatory diseases.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Three new sesquiterpenoids (<B>4</B>, <B>5</B>, and <B>26</B>) and 25 known compounds were obtained from <I>Curcuma phaeocaulis.</I> </LI> <LI> Compounds <B>21</B> and <B>28</B> showed potent inhibitory activities against IL-6-induced STAT3 activation. </LI> <LI> Compounds <B>21</B> and <B>28</B> were suppressed STAT3, JAK2 or ERK phosphorylation in the IL-6 signaling pathway. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

STAT3 활성 억제를 유도하는 resveratrol의 호르몬 불응성 전립선 암 예방 효과

조석철(Seok-Cheol Cho),최부영(Bu Young Choi) 한국식품과학회 2014 한국식품과학회지 Vol.46 No.4

전립선암은 발병률이 높은 암종 중에 하나이다. 전립선 치료제인 flutamide는 androgen 수용체의 호르몬 치료제로서 내성효과에 대한 기본 메커니즘은 명확하지 않다. 본 연구에서는 flutamide에 의해 유도되는 호르몬 불응성 전립선 암세포 성장에서 포도 성분인 resveratrol의 억제효과를 조사하였다. 본 연구의 결과를 통해 호르몬 비의존적인 신호전달의 전환으로 유발되는 호르몬 불응성 전립선 암에서 resveratrol은 예방 및 항암효과에 기여할 것이라 판단된다. The mechanisms underlying the refractory effects of flutamide, a first-line oral anti-androgen drug, have not been entirely elucidated. In the present study, we investigated the mechanism of flutamide-induced hormone-refractory prostate cancer cell growth and its modulation by resveratrol, a phytoalexin present in grapes. Resveratrol significantly attenuated interleukin 6 (IL-6)-induced signal transducer and activator of transcription 3 (STAT3) transcriptional activity and dihydrotestosterone (DHT) or IL-6-induced prostate-specific antigen (PSA) transcriptional activity. Furthermore, compared to treatment with DHT or IL-6 alone, combination treatment of cells significantly increased PSA transcriptional activity, and resveratrol markedly diminished DHT plus IL-6-induced STAT3 and PSA transcriptional activities. Thus, the inhibitory effects of resveratrol on IL-6-, DHT-, and flutamide-induced hormone-refractory prostate cancer cell growth are partly mediated by the suppression of STAT3 reporter gene activity, suggesting that resveratrol represents a promising therapy for prostate cancer.

Activation of the GP130-STAT3 axis and its potential implications in nonalcoholic fatty liver disease

Min, Hae-Ki,Mirshahi, Faridoddin,Verdianelli, Aurora,Pacana, Tommy,Patel, Vaishali,Park, Chun-Geon,Choi, Aejin,Lee, Jeong-Hoon,Park, Chung-Berm,Ren, Shunlin,Sanyal, Arun J. American Physiological Society 2015 American journal of physiology, Gastrointestinal a Vol.308 No.9

<P>The status of the GP130-STAT3 signaling pathway in humans with nonalcoholic fatty liver disease (NAFLD) and its relevance to disease pathogenesis are unknown. The expression of the gp130-STAT3 axis and gp130 cytokine receptors were studied in subjects with varying phenotypes of NAFLD including nonalcoholic steatohepatitis (NASH) and compared with lean and weight-matched controls without NAFLD. Gp130 and its downstream signaling element (Tyk2 and STAT3) expression were inhibited in obese controls whereas they were increased in NAFLD. IL-6 levels were increased in NASH and correlated with gp130 expression (<I>P</I> < 0.01). Palmitate inhibited gp130-STAT3 expression and signaling. IL-6 and palmitate inhibited hepatic insulin signaling via STAT3-dependent and independent mechanisms, respectively. STAT3 overexpression reversed palmitate-induced lipotoxicity by increasing autophagy (ATG7) and decreasing endoplasmic reticulum stress. These data demonstrate that the STAT3 pathway is activated in NAFLD and can worsen insulin resistance while protecting against other lipotoxic mechanisms of disease pathogenesis.</P>

Quercetin Down-regulates IL-6/STAT-3 Signals to Induce Mitochondrial-mediated Apoptosis in a Non-small-cell Lung-cancer Cell Line, A549

Mukherjee, Avinaba,Khuda-Bukhsh, Anisur Rahman KOREAN PHARMACOPUNCTURE INSTITUTE 2015 Journal of pharmacopuncture Vol.18 No.1

Objectives: Quercetin, a flavonoid compound, has been reported to induce apoptosis in cancer cells, but its anti-inflammatory effects, which are also closely linked with apoptosis, if any, on non-small-cell lung cancer (NSCLC) have not so far been critically examined. In this study, we tried to determine if quercetin had any demonstrable anti-inflammatory potential, which also could significantly contribute to inducing apoptosis in a NSCLC cell line, A549. Methods: In this context, several assays, including cytotoxicity, flow cytometry and fluorimetry, were done. Gene expression was analyzed by using a western blot analysis. Results: Results revealed that quercetin could induce apoptosis in A549 cells through mitochondrial depolarization by causing an imbalance in B-cell lymphoma 2/Bcl2 Antagonist X (Bcl2/Bax) ratio and by down-regulating the interleukine-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling pathway. An analysis of the data revealed that quercetin could block nuclear factor kappa-light-chain-enhancer of activated B cells (NF-${\kappa}B$) activity at early hours, which might cause a down-regulation of the IL-6 titer, and the IL-6 expression, in turn, could inhibit p-STAT3 expression. Down-regulation of both the STAT3 and the NF-${\kappa}B$ expressions might, therefore, cause down-regulation of Bcl2 activity because both are major upstream effectors of Bcl2. Alteration in Bcl2 responses might result in an imbalance in the Bcl2/Bax ratio, which could ultimately bring about mitochondria mediated apoptosis in A549 cells. Conclusion: Overall, the finding of this study indicates that a quercetin induced anti-inflammatory pathway in A549 cells appeared to make a significant contribution towards induction of apoptosis in NSCLC and, thus, may have a therapeutic use such as a strong apoptosis inducer in cancer cells.