Antioxidant Effects of PS5, a Peptidomimetic of Suppressor of Cytokine Signaling 1, in Experimental Atherosclerosis

The chronic activation of the Janus kinase/signal transducer and activator of the transcription (JAK/STAT) pathway is linked to oxidative stress, inflammation and cell proliferation. Suppressors of cytokine signaling (SOCS) proteins negatively regulate the JAK/STAT, and SOCS1 possesses a small kinase inhibitory region (KIR) involved in the inhibition of JAK kinases. Several studies showed that KIR-SOCS1 mimetics can be considered valuable therapeutics in several disorders (e.g., diabetes, neurological disorders and atherosclerosis). Herein, we investigated the antioxidant and atheroprotective effects of PS5, a peptidomimetic of KIR-SOCS1, both in vitro (vascular smooth muscle cells and macrophages) and in vivo (atherosclerosis mouse model) by analyzing gene expression, intracellular O2•− production and atheroma plaque progression and composition. PS5 was revealed to be able to attenuate NADPH oxidase (NOX1 and NOX4) and pro-inflammatory gene expression, to upregulate antioxidant genes and to reduce atheroma plaque size, lipid content and monocyte/macrophage accumulation. These findings confirm that KIR-SOCS1-based drugs could be excellent antioxidant agents to contrast atherosclerosis.

Download Full-text

Tofacitinib Suppresses Several JAK-STAT Pathways in Rheumatoid Arthritis In Vivo and Baseline Signaling Profile Associates With Treatment Response

Frontiers in Immunology ◽

10.3389/fimmu.2021.738481 ◽

2021 ◽

Vol 12 ◽

Author(s):

Maaria Palmroth ◽

Krista Kuuliala ◽

Ritva Peltomaa ◽

Anniina Virtanen ◽

Antti Kuuliala ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

T Cells ◽

Treatment Response ◽

Peripheral Blood ◽

Janus Kinase ◽

Cytokine Signaling ◽

Stat3 Phosphorylation ◽

Stat Pathway

ObjectiveCurrent knowledge on the actions of tofacitinib on cytokine signaling pathways in rheumatoid arthritis (RA) is based on in vitro studies. Our study is the first to examine the effects of tofacitinib treatment on Janus kinase (JAK) - signal transducer and activator of transcription (STAT) pathways in vivo in patients with RA.MethodsSixteen patients with active RA, despite treatment with conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), received tofacitinib 5 mg twice daily for three months. Levels of constitutive and cytokine-induced phosphorylated STATs in peripheral blood monocytes, T cells and B cells were measured by flow cytometry at baseline and three-month visits. mRNA expression of JAKs, STATs and suppressors of cytokine signaling (SOCS) were measured from peripheral blood mononuclear cells (PBMCs) by quantitative PCR. Association of baseline signaling profile with treatment response was also investigated.ResultsTofacitinib, in csDMARDs background, decreased median disease activity score (DAS28) from 4.4 to 2.6 (p < 0.001). Tofacitinib treatment significantly decreased cytokine-induced phosphorylation of all JAK-STAT pathways studied. However, the magnitude of the inhibitory effect depended on the cytokine and cell type studied, varying from 10% to 73% inhibition following 3-month treatment with tofacitinib. In general, strongest inhibition by tofacitinib was observed with STAT phosphorylations induced by cytokines signaling through the common-γ-chain cytokine receptor in T cells, while lowest inhibition was demonstrated for IL-10 -induced STAT3 phosphorylation in monocytes. Constitutive STAT1, STAT3, STAT4 and STAT5 phosphorylation in monocytes and/or T cells was also downregulated by tofacitinib. Tofacitinib treatment downregulated the expression of several JAK-STAT pathway components in PBMCs, SOCSs showing the strongest downregulation. Baseline STAT phosphorylation levels in T cells and monocytes and SOCS3 expression in PBMCs correlated with treatment response.ConclusionsTofacitinib suppresses multiple JAK-STAT pathways in cytokine and cell population specific manner in RA patients in vivo. Besides directly inhibiting JAK activation, tofacitinib downregulates the expression of JAK-STAT pathway components. This may modulate the effects of tofacitinib on JAK-STAT pathway activation in vivo and explain some of the differential findings between the current study and previous in vitro studies. Finally, baseline immunological markers associate with the treatment response to tofacitinib.

Download Full-text

Anti-inflammatory, antioxidant and renoprotective effects of SOCS1 mimetic peptide in the BTBR ob/ob mouse model of type 2 diabetes

BMJ Open Diabetes Research & Care ◽

10.1136/bmjdrc-2020-001242 ◽

2020 ◽

Vol 8 (1) ◽

pp. e001242 ◽

Cited By ~ 1

Author(s):

Lucas Opazo-Ríos ◽

Yenniffer Sanchez Matus ◽

Raúl R Rodrigues-Díez ◽

Daniel Carpio ◽

Alejandra Droguett ◽

...

Keyword(s):

Gene Expression ◽

Type 2 Diabetes ◽

Kidney Disease ◽

Mouse Model ◽

Janus Kinase ◽

Cytokine Signaling ◽

Mimetic Peptide ◽

Active Peptide ◽

Socs Proteins

IntroductionDiabetic nephropathy (DN) is the leading cause of chronic kidney disease worldwide. The Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway participates in the development and progression of DN. Among the different mechanisms involved in JAK/STAT negative regulation, the family of suppressor of cytokine signaling (SOCS) proteins has been proposed as a new target for DN. Our aim was to evaluate the effect of SOCS1 mimetic peptide in a mouse model of obesity and type 2 diabetes (T2D) with progressive DN.Research design and methodsSix-week-old BTBR (black and tan brachyuric) mice with the ob/ob (obese/obese) leptin-deficiency mutation were treated for 7 weeks with two different doses of active SOCS1 peptide (MiS1 2 and 4 µg/g body weight), using inactive mutant peptide (Mut 4 µg) and vehicle as control groups. At the end of the study, the animals were sacrificed to obtain blood, urine and kidney tissue for further analysis.ResultsTreatment of diabetic mice with active peptide significantly decreased urine albumin to creatinine ratio by up to 50%, reduced renal weight, glomerular and tubulointerstitial damage, and restored podocyte numbers. Kidneys from treated mice exhibited lower inflammatory infiltrate, proinflammatory gene expression and STAT activation. Concomitantly, active peptide administration modulated redox balance markers and reduced lipid peroxidation and cholesterol transporter gene expression in diabetic kidneys.ConclusionTargeting SOCS proteins by mimetic peptides to control JAK/STAT signaling pathway ameliorates albuminuria, morphological renal lesions, inflammation, oxidative stress and lipotoxicity, and could be a therapeutic approach to T2D kidney disease.

Download Full-text

Epigenetic regulation of neural cell differentiation plasticity in the adult mammalian brain

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.0808417105 ◽

2008 ◽

Vol 105 (46) ◽

pp. 18012-18017 ◽

Cited By ~ 59

Author(s):

Jun Kohyama ◽

Takuro Kojima ◽

Eriko Takatsuka ◽

Toru Yamashita ◽

Jun Namiki ◽

...

Keyword(s):

Gene Expression ◽

Target Genes ◽

Epigenetic Modification ◽

Mammalian Brain ◽

Cytokine Signaling ◽

Specific Gene ◽

Neural Cells ◽

Specific Gene Expression

Neural stem/progenitor cells (NSCs/NPCs) give rise to neurons, astrocytes, and oligodendrocytes. It has become apparent that intracellular epigenetic modification including DNA methylation, in concert with extracellular cues such as cytokine signaling, is deeply involved in fate specification of NSCs/NPCs by defining cell-type specific gene expression. However, it is still unclear how differentiated neural cells retain their specific attributes by repressing cellular properties characteristic of other lineages. In previous work we have shown that methyl-CpG binding protein transcriptional repressors (MBDs), which are expressed predominantly in neurons in the central nervous system, inhibit astrocyte-specific gene expression by binding to highly methylated regions of their target genes. Here we report that oligodendrocytes, which do not express MBDs, can transdifferentiate into astrocytes both in vitro (cytokine stimulation) and in vivo (ischemic injury) through the activation of the JAK/STAT signaling pathway. These findings suggest that differentiation plasticity in neural cells is regulated by cell-intrinsic epigenetic mechanisms in collaboration with ambient cell-extrinsic cues.

Download Full-text

Quercetin Preservesβ-Cell Mass and Function in Fructose-Induced Hyperinsulinemia through Modulating Pancreatic Akt/FoxO1 Activation

Evidence-based Complementary and Alternative Medicine ◽

10.1155/2013/303902 ◽

2013 ◽

Vol 2013 ◽

pp. 1-12 ◽

Cited By ~ 10

Author(s):

Jian-Mei Li ◽

Wei Wang ◽

Chen-Yu Fan ◽

Ming-Xing Wang ◽

Xian Zhang ◽

...

Keyword(s):

Serum Insulin ◽

Cell Mass ◽

Janus Kinase ◽

Cytokine Signaling ◽

Akt Phosphorylation ◽

High Fructose ◽

Stat3 Phosphorylation ◽

And Function

Fructose-induced hyperinsulinemia is associated with insulin compensative secretion and predicts the onset of type 2 diabetes. In this study, we investigated the preservation of dietary flavonoid quercetin on pancreaticβ-cell mass and function in fructose-treated rats and INS-1β-cells. Quercetin was confirmed to reduce serum insulin and leptin levels and blockade islet hyperplasia in fructose-fed rats. It also prevented fructose-inducedβ-cell proliferation and insulin hypersecretion in INS-1β-cells. High fructose increased forkhead box protein O1 (FoxO1) expressionsin vivoandin vitro, which were reversed by quercetin. Quercetin downregulated Akt and FoxO1 phosphorylation in fructose-fed rat islets and increased the nuclear FoxO1 levels in fructose-treated INS-1β-cells. The elevated Akt phosphorylation in fructose-treated INS-1β-cells was also restored by quercetin. Additionally, quercetin suppressed the expression of pancreatic and duodenal homeobox 1 (Pdx1) and insulin gene (Ins1 and Ins2)in vivoandin vitro. In fructose-treated INS-1β-cells, quercetin elevated the reduced janus kinase 2/signal transducers and activators of transcription 3 (Jak2/Stat3) phosphorylation and suppressed the increased suppressor of cytokine signaling 3 (Socs3) expression. These results demonstrate that quercetin protectsβ-cell mass and function under high-fructose induction through improving leptin signaling and preserving pancreatic Akt/FoxO1 activation.

Download Full-text

MicroRNA-653-5p Promotes Gastric Cancer Proliferation and Metastasis by Targeting the SOCS6-STAT3 Pathway

Frontiers in Molecular Biosciences ◽

10.3389/fmolb.2021.655580 ◽

2021 ◽

Vol 8 ◽

Author(s):

Zengliang Li ◽

Hao Fan ◽

Wangwang Chen ◽

Jian Xiao ◽

Xiang Ma ◽

...

Keyword(s):

Gastric Cancer ◽

Janus Kinase ◽

Migration And Invasion ◽

Cytokine Signaling ◽

Cancer Proliferation ◽

Stat3 Signaling ◽

Stat3 Signaling Pathway ◽

Proliferation And Metastasis

MicroRNAs (miRNAs) are emerging as significant regulators of the tumorigenesis of gastric cancer (GC), and may be effective biomarkers for diagnosis, prognosis, and therapeutic targeting for GC. In this study, miR-653-5p was found to be significantly upregulated in GC tissues, serum, and cell lines and was strongly associated with poor prognosis in patients with GC. Furthermore, miR-653-5p promoted GC cell proliferation and metastasis in vivo and in vitro. Suppressor of cytokine signaling 6 (SOCS6) was directly targeted by miR-653-5p, and SOCS6 attenuated miR-653-5p-mediated GC cell growth, migration, and invasion. In addition, SOCS6-mediated inactivation of the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway was also reversed by the administration of miR-653-5p. The findings from this study support a novel regulatory axis between miR-653-5p, SOCS6, and JAK2/STAT3 that may be a target for diagnosis and therapeutic intervention for GC.

Download Full-text

Induction of SOCS Expression by EV71 Infection Promotes EV71 Replication

BioMed Research International ◽

10.1155/2020/2430640 ◽

2020 ◽

Vol 2020 ◽

pp. 1-9 ◽

Cited By ~ 1

Author(s):

Wenying Gao ◽

Min Hou ◽

Xin Liu ◽

Zhaolong Li ◽

Yongjun Yang ◽

...

Keyword(s):

Type I Interferon ◽

Enterovirus 71 ◽

Ev71 Infection ◽

Cytokine Signaling ◽

Host Immune System ◽

Type I ◽

Stat3 Phosphorylation ◽

Socs Proteins

Enterovirus 71 (EV71) is the causative pathogen of hand, foot, and mouth disease (HFMD). However, no effective antiviral therapy is currently available. Some viruses could escape the host’s innate immunity by upregulating suppressor of cytokine signaling (SOCS) proteins. Until now, whether EV71 evades the host immune system by regulating the expression of SOCS proteins remains unknown. In this study, we found that EV71 infection promoted SOCS expression at both mRNA and protein levels in vitro and in vivo. Consistently, the infectivity of EV71 was decreased significantly in the SOCS3 or SOCS1 knockdown cells, suggesting that SOCS1 and especially SOCS3 are crucial for EV71 infection. Further investigation showed that SOCS3 promoted virus infection by inhibiting interferon-induced STAT3 phosphorylation. SOCS1 and SOCS3 mRNA expressions were independent on virus-induced type I interferon expression but were blocked by the inhibitor of NF-κB. Therefore, EV71 infection stimulates the expression of SOCS proteins in an interferon-independent way and negatively regulates the JAK/STAT signaling pathway, thus escaping host immunity. All these results may add new information to the mechanism of EV71 in fighting against type I interferon responses.

Download Full-text

Selective Immunomodulation of Inflammatory Pathways in Keratinocytes by the Janus Kinase (JAK) Inhibitor Tofacitinib: Implications for the Employment of JAK-Targeting Drugs in Psoriasis

Journal of Immunology Research ◽

10.1155/2018/7897263 ◽

2018 ◽

Vol 2018 ◽

pp. 1-18 ◽

Cited By ~ 8

Author(s):

Martina Morelli ◽

Claudia Scarponi ◽

Laura Mercurio ◽

Francesco Facchiano ◽

Sabatino Pallotta ◽

...

Keyword(s):

Skin Lesions ◽

Janus Kinase ◽

Psoriatic Skin ◽

Epidermal Keratinocytes ◽

Cytokine Signaling ◽

Molecular Signaling ◽

Suppressor Of Cytokine Signaling ◽

Inflammatory Genes

IFN-γ and IL-22 are deeply involved in the pathogenesis of psoriasis, as they boost the expression of inflammatory genes and alter proliferative and differentiative programs in keratinocytes. The JAK1/JAK2/STAT1 and JAK1/TYK2/STAT3 pathways triggered by IFN-γ and IL-22, respectively, are aberrantly activated in psoriasis, as highlighted by the peculiar STAT1 and STAT3 signatures in psoriatic skin lesions. To limit the detrimental consequences of IFN-γ and IL-22 excessive stimulation, psoriatic keratinocytes activate suppressor of cytokine signaling (SOCS)1 and SOCS3, which in turn dampen molecular signaling by inhibiting JAK1 and JAK2. Thus, JAK targeting appears to be a reasonable strategy to treat psoriasis. Tofacitinib is an inhibitor of JAK proteins, which, similarly to SOCS, impedes JAK phosphorylation. In this study, we evaluated the immunomodulatory effects of tofacitinib on epidermal keratinocytes in in vitro and in vivo models of psoriasis. We demonstrated the selectivity of tofacitinib inhibitory action on IFN-γ and IL-22, but not on TNF-γ or IL-17 proinflammatory signaling, with suppressed expression of IFN-γ-dependent inflammatory genes, and restoration of normal proliferative and differentiative programs altered by IL-22 in psoriatic keratinocyte cultures. Tofacitinib also potently reduced the psoriasiform phenotype in the imiquimod-induced murine model of psoriasis. Finally, we found that tofacitinib mimics SOCS1 or SOCS3 activities, as it impaired the same molecular pathways in IFN-γ or IL-22-activated keratinocytes.

Download Full-text

Combining LSD1 and JAK-STAT inhibition targets Down syndrome-associated myeloid leukemia at its core

10.1101/2022.01.14.476342 ◽

2022 ◽

Author(s):

Juliane Grimm ◽

Raj Bhayadia ◽

Lucie Gack ◽

Dirk Heckl ◽

Jan-Henning Klusmann

Keyword(s):

Gene Expression ◽

Down Syndrome ◽

Targeted Therapies ◽

Gene Expression Pattern ◽

Cytokine Signaling ◽

Transcriptional Level ◽

Megakaryoblastic Leukemia ◽

Lysine Specific Demethylase

Children with Down syndrome (DS) are predisposed to developing megakaryoblastic leukemia (ML-DS) and often experience severe toxicities from chemotherapy, highlighting the need for targeted therapies with beneficial risk profiles. The genomic landscape of ML-DS is characterized by a combination of mutations in signaling pathway genes and epigenetic modifiers, while aberrant lysine specific demethylase 1 (LSD1) and JAK-STAT activation have both been implicated in leukemogenesis. Here, we demonstrate that combined LSD1 and JAK1/2 inhibition exerts synergistic anti-leukemic effects specifically in ML-DS, both in vitro and in patient derived xenografts in vivo. The JAK1/2 inhibitor ruxolitinib enhanced the LSD1 inhibitor-induced differentiation, proliferation arrest and apoptosis in patient-derived leukemic blasts. At the transcriptional level, the combination synergistically repressed gene expression signatures essential for cell division. We further observed an immunogenic gene expression pattern in the form of increased cytokine signaling, which - by sensitizing ML-DS blasts to the JAK-STAT signaling blockade induced by ruxolitinib - could explain the increased susceptibility of ML-DS blasts to combination therapy. Taken together, we establish combined LSD1 and JAK-STAT inhibition as an efficacious therapeutic regimen specifically designed to target important steps in ML-DS leukemogenesis, paving the way for targeted therapies in this entity.

Download Full-text