Activation Of Transcription Factor AP-1 Research Articles

The enhancer RNA, AANCR, regulates APOE expression in astrocytes and microglia.

Enhancers, critical regulatory elements within the human genome, are often transcribed into enhancer RNAs. The dysregulation of enhancers leads to diseases collectively termed enhanceropathies. While it is known that enhancers play a role in diseases by regulating gene expression, the specific mechanisms by which individual enhancers cause diseases are not well understood. Studies of individual enhancers are needed to fill this gap. This study delves into the role of APOE-activating noncoding RNA, AANCR, in the central nervous system, elucidating its function as a genetic modifier in Alzheimer's Disease. We employed RNA interference, RNaseH-mediated degradation, and single-molecule RNA fluorescence in situ hybridization to demonstrate that mere transcription of AANCR is insufficient; rather, its transcripts are crucial for promoting APOE expression. Our findings revealed that AANCR is induced by ATM-mediated ERK phosphorylation and subsequent AP-1 transcription factor activation. Once activated, AANCR enhances APOE expression, which in turn imparts an inflammatory phenotype to astrocytes. These findings demonstrate that AANCR is a key enhancer RNA in some cell types within the nervous system, pivotal for regulating APOE expression and influencing inflammatory responses, underscoring its potential as a therapeutic target in neurodegenerative diseases.

Abstract B026: APOBEC3 promotes squamous differentiation via IL1A/AP-1 signaling

Abstract The APOBEC family of cytidine deaminase enzymes catalyze the conversion of cytosine to uracil in ssDNA and RNA substrates. The resulting C to U transition has been noted in the innate immune response to viral infection, and somatic hypermutation. However, APOBEC family members APOBEC3A (hA3A) and APOBEC3B (hA3B) have been implicated as drivers of the APOBEC3 mutational signatures in numerous cancer types. Notably, approximately 70% of single nucleotide variant mutations in bladder cancer can be attributed to APOBEC3 induced mutagenesis. Studies have implicated various APOBEC3 family members to be drivers of tumorigenesis, disease progression, and therapeutic resistance. To investigate APOBEC3’s role in bladder cancer, we have generated a novel, cre-inducible, pten and p53 knockout, to overexpress mouse Apobec3(mA3) in Upk3a+ cells (UPPA), compared to a model that does not overexpress mA3 (UPP). Apobec3 expression was shown to accelerate bladder tumor formation, indicated by a shorter median time of tumor latency in the UPPA model (43.3 weeks) compared to the UPP model (53.6 weeks). While both tumor models had presence of squamous differentiation, the extensiveness was more profound in the UPPA tumors. Transcriptional analysis of UPP and UPPA tumors, via scRNA sequencing, revealed an enrichment of squamous gene expression in the UPPA tumors. Utilizing mouse syngeneic bladder cancer cell lines and normal bladder urothelial cells, we overexpressed mA3 in a doxycycline inducible manner. Overexpression of mA3 was shown to prevent luminal differentiation. Additionally, mA3 overexpression resulted in the increase of IL-1a production. IL-1a production was sufficient to drive squamous differentiation in BBN963 and normal bladder urothelial cells. Blocking cFOS and IL-1R, individually, prevented expression of squamous genes. These results suggest that DNA damage induced by mA3 is sufficient to drive squamous differentiation via signaling through IL-1a resulting in AP-1 transcription factor activation. We then analyzed bladder cancer samples from The Cancer Genome Atlas and found that hA3A was the only APOBEC family member to be significantly associated with squamous gene expression. Interestingly, hA3A expression was enriched in the basal/squamous consensus subtype. To further interrogate the potential of hA3A being a driver of squamous differentiation in bladder cancer, we have also generated doxycycline inducible expression of hA3A and hA3B in syngeneic bladder cancer cell lines. Targeting IL-1a in various autoimmune diseases has resulted in FDA approval of antibodies targeting IL-1a and IL-1R. Given the clinical utility of targeting IL-1a, it is plausible to target this signaling axis for therapeutic benefit in bladder cancers with ongoing hA3A activity. In aggregate, our work demonstrates the promotion of an aggressive tumor state, driven by APOBEC mutagenesis and implicates hA3A as a possible driver of squamous differentiation in urothelial carcinoma. Citation Format: Andrew S. Truong, Michael S. Sturdivant, Mi Zhou, Wolfgang A. Beckabir, John Raupp, Ujjawal Manocha, Elliot D. Toomer, Ibardo A. Zambrano, Hung-Jui Tan, Marc A. Bjurlin, Angela B. Smith, Tracy L. Rose, Matthew I. Milowsky, Sara E. Wobker, Kathryn H. Gessner, Jeffrey S. Damrauer, William Y. Kim. APOBEC3 promotes squamous differentiation via IL1A/AP-1 signaling [abstract]. In: Proceedings of the AACR Special Conference on Bladder Cancer: Transforming the Field; 2024 May 17-20; Charlotte, NC. Philadelphia (PA): AACR; Clin Cancer Res 2024;30(10_Suppl):Abstract nr B026.

Bisphenol A regulates bladder cells responses via control of G2/M-phase cell cycle, apoptotic signaling, MAPK pathway, and transcription factor-associated MMP modulation.

Bisphenol A (BPA), an exogenous endocrine-disrupting chemical,is widely used to produce polycarbonate plastics. The widely used BPA has been detected in human urine samples, raising public anxiety about the detrimental effects of BPA on the bladder. In this study, we explored regulatory mechanisms for the adverse effects of BPA in human bladder BdFCand T24 cells. BPA induced extrinsic and intrinsic apoptosis and G2/M cell cycle arrest caused by the ATM-CHK1/CHK2-CDC25c-CDC2 signaling, which ultimately inhibited the growth of human bladder cells. We also found that BPA decreased the binding activity of AP-1 and NF-κB transcription factors in human bladder cells, which inhibited migration and invasion through matrix metallopeptidase-2 and -9 inactivation. Phosphorylation of MAPKs was implicated with BPA-mediated detrimental effects in human bladder cells. Collectively, our results provide a novel explanation for the underlying molecular mechanisms that BPA induces cytotoxicity in human bladder cells.

A microRNA Arising from the Negative Strand of SARS-CoV-2 Genome Targets FOS to Reduce AP-1 Activity.

Virus-encoded microRNAs were first reported in the Epstein-Barr virus in 2004. Subsequently, a few hundred viral miRNAs have been identified, mainly in DNA viruses belonging to the herpesviridae family. To date, only 30 viral miRNAs encoded by RNA viruses are reported by miRBase. Since the outbreak of the SARS-CoV-2 pandemic, several studies have predicted and, in some cases, experimentally validated miRNAs originating from the positive strand of the SARS-CoV-2 genome. By integrating NGS data analysis and qRT-PCR approaches, we found that SARS-CoV-2 also encodes for a viral miRNA arising from the minus (antisense) strand of the viral genome, in the region encoding for ORF1ab, herein referred to as SARS-CoV-2-miR-AS1. Our data show that the expression of this microRNA increases in a time course analysis of SARS-CoV-2 infected cells. Furthermore, enoxacin treatment enhances the accumulation of the mature SARS-CoV-2-miR-AS1 in SARS-CoV-2 infected cells, arguing for a Dicer-dependent processing of this small RNA. In silico analysis suggests that SARS-CoV-2-miR-AS1 targets a set of genes which are translationally repressed during SARS-CoV-2 infection. We experimentally validated that SARS-CoV-2-miR-AS1 targets FOS, thus repressing the AP-1 transcription factor activity in human cells.

Skin aging from the perspective of dermal fibroblasts: the interplay between the adaptation to the extracellular matrix microenvironment and cell autonomous processes.

This article summarizes important molecular mechanisms that drive aging in human skin from the perspective of dermal fibroblasts. The dermis comprises the bulk of the skin and is largely composed of a collagen-rich extracellular matrix (ECM). The dermal ECM provides mechanical strength, resiliency, and an environment that supports the functions of ibroblasts and other types of dermal cells. Fibroblasts produce the dermal ECM and maintain its homeostasis. Fibroblasts attach to the ECM and this attachment controls their morphology and function. During aging, the ECM undergoes gradual degradation that is nitiated by matrix metalloproteinases (MMPs). This degradation alters mechanical forces within the dermal ECM and disrupts he interactions between fibroblasts and the ECM thereby generating an aged fibroblast phenotype. This aged fibroblast phenotype is characterized by collapsed morphology, altered mechanosignaling, induction of CCN1, and activation of transcription factor AP-1, with consequent upregulation of target genes including MMPs and pro-inflammatory mediators. The TGF-beta pathway coordinately regulates ECM production and turnover. Altered mechanical forces, due to ECM fragmentation, down-regulate the type II TGF-beta receptor, thereby reducing ECM production and further increasing ECM breakdown. Thus, dermal aging involves a feed-forward process that reinforces the aged dermal fibroblast phenotype and promotes age-related dermal ECM deterioration. As discussed in the article, the expression of the aged dermal fibroblast phenotype involves both adaptive and cell-autonomous mechanisms.

Single-cell sequencing of PBMC characterizes the altered transcriptomic landscape of classical monocytes in BNT162b2-induced myocarditis.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been the most dangerous threat to public health worldwide for the last few years, which led to the development of the novel mRNA vaccine (BNT162b2). However, BNT162b2 vaccination is known to be associated with myocarditis. Here, as an attempt to determine the pathogenesis of the disease and to develop biomarkers to determine whether subjects likely proceed to myocarditis after vaccination, we conducted a time series analysis of peripheral blood mononuclear cells of a patient with BNT162b2-induced myocarditis. Single-cell RNA sequence analysis identified monocytes as the cell clusters with the most dynamic changes. To identify distinct gene expression signatures, we compared monocytes of BNT162b2-induced myocarditis with monocytes under various conditions, including SARS-CoV-2 infection, BNT162b2 vaccination, and Kawasaki disease, a disease similar to myocarditis. Representative changes in the transcriptomic profile of classical monocytes include the upregulation of genes related to fatty acid metabolism and downregulation of transcription factor AP-1 activity. This study provides, for the first time, the importance of classical monocytes in the pathogenesis of myocarditis following BNT162b2 vaccination and presents the possibility that vaccination affects monocytes, further inducing their differentiation and infiltration into the heart.

Regulation of Interleukin-36γ/IL-36R Signaling Axis by PIN1 in Epithelial Cell Transformation and Breast Tumorigenesis.

Simple SummaryMembers of the interleukin (IL)-1 cytokine family exhibit dual functions in the regulation of inflammation and cancer. Recent studies have shown the critical role of IL-36γ, the newly identified IL-1 family member, in the regulation of cellular processes implicated in the progression of cancer. Therefore, the underlying mechanism of IL-36γ in tumor development is of considerable interest. Here, we identified the pivotal role of IL-36γ in the proliferation of breast cancer cells. Consistently, IL-36γ was found to promote epithelial cell transformation via the activation of c-Fos, c-Jun, and AP-1 transcription factors, followed by the IL36R-mediated MEK/ERK and JNK/c-Jun cascades. Furthermore, our findings demonstrate the critical role of PIN1 in the regulation of IL-36γ-induced mammary gland tumorigenesis. Given the increasing recognition of the relationship between IL-1 cytokines, inflammation, and cancer, the significance of distinct members of the IL-1 cytokine family in the etiology of cancer has been widely researched. In the present study, we investigated the underlying mechanism of the IL-36γ/IL-36R axis during breast cancer progression, which has not yet been elucidated. Initially, we determined the effects of IL-36γ on the proliferation and epithelial cell transformation of JB6 Cl41 mouse epidermal and MCF7 human breast cancer cells using BrdU incorporation and anchorage-independent growth assays. We found that treatment with IL-36γ increased the proliferation and colony formation of JB6 Cl41 and MCF7 cells. Analysis of the mechanism underlying the neoplastic cell transformation revealed that IL-36γ induced IL-36R-mediated phosphorylation of MEK1/2, ERK1/2, JNK1/2, and c-Jun, resulting in increased c-Fos, c-Jun, and AP-1 activities in JB6 Cl41 and MCF7 cells. Furthermore, the IL-36γ-induced tumorigenic capacity of MCF7 cells was considerably enhanced by PIN1, following MEK/ERK and JNK/c-Jun signaling. Interestingly, blocking PIN1 activity using juglone suppressed the IL-36γ-induced increase in the anchorage-independent growth of 4T1 metastatic mouse breast cancer cells. Finally, in a syngeneic mouse model, IL-36γ-induced tumor growth in the breast mammary gland was significantly inhibited following PIN1 knockout.

Abstract 3815: Investigating the role of bone marrow microenvironment dysregulation at remission in disease outlook of multiple myeloma

Abstract Multiple myeloma (MM) is a cancer characterized by the unchecked proliferation of antibody-secreting plasma cells (PCs), which to date remains incurable despite therapeutic advancements. The idea that deeper tumor clearance leads to better outcomes is widely accepted in MM treatment: minimal residual disease (MRD) testing, whereby ultra-sensitive sequencing or fluorescence-based cytometric detection of the clonal immunoglobulin secreted by tumor PCs, has been found to be the strongest independent prognostic factor when predicting survival. However, MRD status remains an imperfect predictor. As PCs have a well-defined physiological niche within the bone marrow (BM), and patients often exhibit immunosuppressive BM dysregulation, we investigate the presence of BM microenvironment signatures present at remission that may influence clinical outcomes insufficiently explained by tumor risk strata or MRD status. We conducted 3’ single-cell RNA sequencing of 36 remission, 8 primary diagnosis, and 3 relapse whole BM aspirates taken from 35 patients enrolled in an ongoing clinical trial evaluating a treatment regimen consisting of ixazomib, lenalidomide, and dexamethasone (IRD). 19 of 35 patients were MRD+ at remission; among these, 6 have been reported as having poor outcome (PO; progression-free survival <2.5yrs post sample collection), 12 have had average outcomes (AO; PFS >2.5yrs), and 1 is awaiting assessment. The remaining 16 patients were MRD- at remission, 6 of whom had poor outcome, 7 average, and 3 awaiting assessment. Preliminary analysis of 43 samples have yielded an average capture of 8,620 cells per sample with 1,247 median genes per cell. In comparing 3 PO to 8 AO MRD- remission samples, we see clear polarity between PO and AO cells in every major immune lineage, with a majority of clusters being predominantly (>80%) made of either PO or AO cells. Surprisingly, T, NK, and B cells from AO samples exhibit FOS/JUN upregulation relative to those from PO samples, indicative of AP-1 transcription factor activity that is typically associated with cell proliferation. PO samples also exhibited signs of active cytotoxicity, including upregulated granzymes H and B and IL7R in T and NK cells. Sizeable PC populations were detected in several MRD- remission samples with subpopulation heterogeneity in the expression of MM marker genes; comparison against PCs isolated from healthy donor BM suggests possible persistence of disease phenotypes not captured by MRD testing. We further investigate BM microenvironment evolution between primary diagnosis, remission, and relapse timepoints to elucidate changes in response to tumor clearance. Overall, this study enhances our understanding of how immune surveillance and interaction may influence treatment response in MM. Citation Format: Julia T. Wang, Mark Fiala, Julie Fortier, Ruiyang Liu, Reyka Jayasinghe, Ravi Vij, Li Ding. Investigating the role of bone marrow microenvironment dysregulation at remission in disease outlook of multiple myeloma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 3815.

African Swine Fever Virus Ubiquitin-Conjugating Enzyme Is an Immunomodulator Targeting NF-κB Activation.

African swine fever virus (ASFV) is an acute and persistent swine virus with a high economic burden that encodes multiple genes to evade host immune response. In this work, we have revealed that early viral protein UBCv1, the only known conjugating enzyme encoded by a virus, modulates innate immune and inflammatory signaling. Transient overexpression of UBCv1 impaired activation of NF-κB and AP-1 transcription factors induced by several agonists of these pathways. In contrast, activation of IRF3 and ISRE signaling upon stimulation with TRIFΔRIP, cGAS/STING or RIG-I-CARD remained unaltered. Experiments aimed at mapping UBCv1 inhibitory activity indicated that this viral protein acts upstream or at the level step of IKKβ. In agreement with this, UBCv1 was able to block p65 nuclear translocation upon cytokine stimulation, a key event in NF-ĸB signaling. Additionally, A549 stably transduced for UBCv1 showed a significant decrease in the levels of NF-ĸB dependent genes. Interestingly, despite the well-defined capacity of UBCv1 to conjugate ubiquitin chains, a mutant disabled for ubiquitylation activity retained similar immunomodulatory activity as the wild-type enzyme, suggesting that the two functions are segregated. Altogether these data suggest that ASFV UBCv1 manipulates the innate immune response targeting the NF-κB and AP-1 pathways and opens new questions about the multifunctionality of this enzyme.

Docosahexaenoic fatty acid reduces the pro\u2010inflammatory response induced by IL-1\u03b2 in astrocytes through inhibition of NF-\u03baB and AP-1 transcription factor activation

BackgroundAstrocytes are responsible for a broad range of functions that maintain homeostasis in the brain. However, their response to the pro-inflammatory cytokines released by activated microglia in various neurological pathologies may exacerbate neurodegenerative processes. Accumulating evidence suggests that omega-3 docosahexaenoic fatty acid (DHA) has an anti-inflammatory effect in various cell cultures studies and in a variety of neurological disorders. In this study we examined the mechanism involved in the inhibition of the pro-inflammatory response by DHA in astrocytes treated with IL-1β.Methods and resultsActivation of the transcription factors NF-κB and AP-1 was measured in IL-1β-treated primary astrocytes incubated with various concentrations of DHA. COX-2 and iNOS protein expression was determined by Western blot, and TNF-α and IL-6 secretion was measured using ELISA-based assays. DHA treatment inhibited translocation of p65NF-κB to the nucleus, significantly lowered p65NF-κB protein level and fluorescence of p65NF-κB in the nucleus, reduced dose-dependently IκB protein phosphorylation, and the binding of the AP-1 transcription factor members (c-Jun/c-Fos) to the specific TPA-response element (TRE) of DNA. In addition, the expression of pro-inflammatory COX-2 and iNOS proteins was downregulated and TNF-α and IL-6 secretion was also reduced.ConclusionsThese results indicate that DHA is a powerful factor that reduces the pro-inflammatory response in astrocytes. Consequently, successful introduction of DHA into the astrocyte membranes can attenuate neuroinflammation, which is a key factor of age-related neurodegenerative disorders.

MEK/ERK signaling is a critical regulator of high-risk human papillomavirus oncogene expression revealing therapeutic targets for HPV-induced tumors.

Intracellular pathogens have evolved to utilize normal cellular processes to complete their replicative cycles. Pathogens that interface with proliferative cell signaling pathways risk infections that can lead to cancers, but the factors that influence malignant outcomes are incompletely understood. Human papillomaviruses (HPVs) predominantly cause benign hyperplasia in stratifying epithelial tissues. However, a subset of carcinogenic or “high-risk” HPV (hr-HPV) genotypes are etiologically linked to nearly 5% of all human cancers. Progression of hr-HPV-induced lesions to malignancies is characterized by increased expression of the E6 and E7 oncogenes and the oncogenic functions of these viral proteins have been widely studied. Yet, the mechanisms that regulate hr-HPV oncogene transcription and suppress their expression in benign lesions remain poorly understood. Here, we demonstrate that EGFR/MEK/ERK signaling, influenced by epithelial contact inhibition and tissue differentiation cues, regulates hr-HPV oncogene expression. Using monolayer cells, epithelial organotypic tissue models, and neoplastic tissue biopsy materials, we show that cell-extrinsic activation of ERK overrides cellular control to promote HPV oncogene expression and the neoplastic phenotype. Our data suggest that HPVs are adapted to use the EGFR/MEK/ERK signaling pathway to regulate their productive replicative cycles. Mechanistic studies show that EGFR/MEK/ERK signaling influences AP-1 transcription factor activity and AP-1 factor knockdown reduces oncogene transcription. Furthermore, pharmacological inhibitors of EGFR, MEK, and ERK signaling quash HPV oncogene expression and the neoplastic phenotype, revealing a potential clinical strategy to suppress uncontrolled cell proliferation, reduce oncogene expression and treat HPV neoplasia.

Constitutive activation of transcription factor AP-1 in primary adult T-cell leukemia cells

AbstractHuman T-cell leukemia virus type-I (HTLV-I) is the etiologic agent of adult T-cell leukemia (ATL). This study examined the status of the oncogenic transcription factor AP-1 in leukemic cells freshly isolated from patients with ATL. Leukemic cells from peripheral blood of all patients with ATL exhibited constitutive AP-1 DNA binding activity, whereas mononuclear cells from normal individuals did not. In agreement with previous studies, HTLV-I transforming protein, Tax, was found to stimulate the DNA binding activity of AP-1 in a T-cell line. However, HTLV-I genes, including Tax, were not significantly expressed in leukemic cells freshly obtained from patients with ATL. Moreover, all T-cell lines derived from leukemic cells of patients with ATL also displayed constitutive AP-1 DNA binding activity, but expressed little Tax protein. Thus, leukemic cells of patients with ATL appear to have Tax-independent mechanisms that induce AP-1 activity, both in vivo and in vitro. In antibody supershift experiments, AP-1 in fresh leukemic cells and ATL-derived cell lines were found to contain JunD. Consistently, all primary ATL cells and ATL-derived cell lines expressed high levels of JunD messenger RNA. Our results suggest that AP-1 is activated in leukemic cells of patients with ATL through a Tax-independent mechanism and this may play a role in the deregulated phenotypes of ATL leukemic cells.

NOD1/2 and the C-Type Lectin Receptors Dectin-1 and Mincle Synergistically Enhance Proinflammatory Reactions Both In Vitro and In Vivo.

PurposePathogens consist of a wide variety of evolutionarily conserved molecular structures that are recognized by pattern recognition receptors (PRRs) of innate immunity. Reasonably assuming that no single PRR is ever likely to be the sole trigger of the immune response during infection, a great deal remains unknown about collaborative mechanisms and consequential crosstalk effects between multiple PRRs belonging to different families. Here, we aimed to investigate inflammatory response to combined stimulation of cytosolic nucleotide-binding oligomerization domain (NOD) receptors: NOD1, NOD2 and membrane-bound C-type lectin receptors (CLRs): Mincle and Dectin-1 in comparison to individual stimulation both in vitro and in vivo.Materials and MethodsFor in vitro studies, we used human monocytic THP-1 cells endogenously expressing NOD1,2, as well as Mincle and Dectin-1 receptors. Using reporter gene and immunoassay approaches, we measured activity of key proinflammatory transcription factors (NF-κB and AP-1) and cytokine production after addition of specific PRR agonists or their pairwise combinations. In vivo NF-κB activity (bioluminescent detection in NF-κB-Luc transgenic mice), as well as cytokine levels in mouse blood serum, was measured 3 hours after intramuscular injection of PRR agonists.ResultsWe detected that combined stimulation of NOD1/2 and C-type lectin receptors (Dectin-1, Mincle) strongly potentiates NF-κB and AP-1 transcription factor activity in human monocytic THP-1 cells, as well as resulting in enhanced levels of IL-8 cytokine production. We demonstrated that RIP2- and Syk-dependent signaling pathways downstream of NOD1/2 and Dectin-1/Mincle, respectively, are essential for the potentiated proinflammatory cell response. Lastly, we confirmed that synergy between NOD and C-type lectin receptors resulting in potentiated levels of NF-κB activation and cytokine (IL-6, KC) production also occurs in vivo.ConclusionThese findings originally indicate cooperation between NODs and CLRs, leading to potentiated levels of proinflammatory immune response both in vitro and in vivo.

Imatinib +/- Brentuximab Vedotin Induces Sustained Complete Remission in Chemotherapy-Resistant Anaplastic Large Cell Lymphoma Expressing PDGFR

Background. Anaplastic lymphoma kinase positive systemic anaplastic large cell lymphoma (ALK+ ALCL) represents an aggressive T-cell malignancy that primarily affects children and younger adults. Upon treatment with CHOP (cyclophosphamide, doxorubicin, vincristine, and prednisone) or CHOP-like regimens its prognosis is relatively favourable compared to other aggressive T-cell lymphomas, however, the rare event of disease reoccurrence remains particularly challenging. ALCL is CD30 positive, and mono treatment with brentuximab vedotin (BrV) can achieve long term remissions in only few relapsed patients not receiving consolidating stem cell transplantation (Pro B. et al. Blood 2017). A subset of ALCL patients express platelet derived growth factor receptor (PDGFR) alpha or beta in their tumour cells which is induced by ALK via AP-1 transcription factor activation. We previously demonstrated that PDGFR blockade by the Abl/c-Kit/PDGFR kinase inhibitor imatinib is an effective treatment concept for ALK+ ALCL in experimental mouse models (Laimer D. et al. Nature Med. 2012). Here we aimed to assess the prognostic value of PDGFR expression and to probe the clinical value of its targeting by imatinib in ALK+ ALCL patients. Methods. The impact of PDGFR expression to predict clinical outcome was analyzed in samples of 98 ALK+ ALCL patients included in the studies NHL-BFM 90, 95 and ALCL99 between 1992 and 2006. Six patients (age 18-45) with chemo-refractory ALK+ ALCL were prospectively treated with imatinib plus (4) or minus (2) BrV. 33% (2/6) had previously received salvage treatment with stem cell transplantation (SCT). Three of the patients had been enrolled in a prospective single-arm study combining imatinib and BrV, a trial that was terminated due to poor patient recruitment (AGMT ALCL1 trial, EudraCT No.: 2013-003505-26, supported by Takeda®). PDGFR alpha and beta expression analyses were performed on tumour samples of treated patients. Results. ALK+ ALCL patients with high PDGFR expression on tumor cells (n=11) had a significantly lower event-free survival rate (EFS) at 5 years compared to patients with no or low expression (n=87) (27±13% versus 70±5%, respectively, p<0.001, figure 1a). Four of the six patients with relapsed/ refractory ALK+ ALCL responded to imatinib +/- BrV with a rapid metabolic complete remission (CR). At a median clinical follow-up of 52 months (range 20 to108) all responding patients demonstrated an ongoing CR without SCT even after imatinib was discontinued with an average time on imatinib of 49 weeks (range 32 to 130; figure 1b). Half (2/4) of responding patients received no or only 1 infusion of BrV; both non-responding patients had received BrV. Importantly, despite the few patients that could be prospectively treated, PDGFR expression status had a significant impact on clinical course. All patients (4/4) who expressed either PDGFR alpha or beta in tumour cells and in the lymph node microenvironment responded with an ongoing metabolic CR, whereas the two patients whose lymphoma cells had negative PDGFR expression failed to respond (EFS: 4 versus 210 weeks, p = 0.018; figure 1c). Conclusions. 1) PDGFR expression is a poor risk factor in ALK+ ALCL. 2) Imatinib alone or in combination with BrV overcomes chemo-resistance conferred by PDGFR expression. 3) Imatinib treatment can be discontinued with ongoing CR. 4) These observations suggest that PDGFR expressing ALK+ ALCL patients might benefit from early treatment with imatinib. Disclosures Staber: Takeda-Millenium: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; AbbVie: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Roche: Honoraria, Membership on an entity's Board of Directors or advisory committees, Research Funding, Speakers Bureau; Janssen: Honoraria, Speakers Bureau; MSD: Honoraria, Speakers Bureau; Gilead: Honoraria, Membership on an entity's Board of Directors or advisory committees, Speakers Bureau; Celgene: Honoraria, Membership on an entity's Board of Directors or advisory committees. Klapper:Roche, Takeda, Amgen, Regeneron: Honoraria, Research Funding. Mayerhoefer:Siemens: Research Funding, Speakers Bureau; BMS: Speakers Bureau. Greil:Gilead: Consultancy, Honoraria, Research Funding; AbbVie: Consultancy, Honoraria, Research Funding; Pfizer: Honoraria, Research Funding; Ratiopharm: Research Funding; Novartis: Consultancy, Honoraria, Research Funding; Eisai: Honoraria; Genentech: Honoraria, Research Funding; Janssen-Cilag: Honoraria; GSK: Research Funding; Sandoz: Honoraria; Roche: Consultancy, Honoraria, Research Funding; Daiichi Sankyo: Consultancy, Honoraria; MSD: Consultancy, Honoraria, Research Funding; Merck: Consultancy, Honoraria, Research Funding; AstraZeneca: Consultancy, Honoraria, Research Funding; Takeda: Consultancy, Honoraria, Research Funding; Sanofi Aventis: Honoraria; Boehringer Ingelheim: Honoraria; Mundipharma: Honoraria, Research Funding; Celgene: Consultancy, Honoraria, Research Funding. Jaeger:Novartis, Roche, Sandoz: Consultancy; AbbVie, Celgene, Gilead, Novartis, Roche, Takeda Millennium: Research Funding; Amgen, AbbVie, Celgene, Eisai, Gilead, Janssen, Novartis, Roche, Takeda Millennium, MSD, BMS, Sanofi: Honoraria; Celgene, Roche, Janssen, Gilead, Novartis, MSD, AbbVie, Sanofi: Membership on an entity's Board of Directors or advisory committees. OffLabel Disclosure: Imatinib - bcr-abl Inhibitor

EFFECT OF AP-1 TRANSCRIPTION FACTOR INHIBITOR ON STRUCTURAL, METABOLIC AND BIOMECHANICAL CHANGES IN BONE TISSUE DURING COMBINED EXCESSIVE INTAKE OF SODIUM FLUORIDE AND SODIUM NITRATE

This article highlights the effect produced by the inhibitor of the AP-1 transcription factor activation on the mechanisms of structural, metabolic and biomechanical disorders in the femoral bones and vertebrae during combined excessive intake of sodium fluoride and sodium nitrate. The experiment was conducted on 30 white rats divided into 4 groups: the 1st included the intact animals, the 2nd group involved the rats subjected to the co- administration of sodium fluoride (10 mg / kg body weight) and sodium nitrate (500 mg / kg body weight) for 30 days, the 3rd group included the animals, which starting from the 15th day of intoxication, were injected SR 11302 ((E, E, Z, E) -3-Methyl-7- (4-methylphenyl) - 9- (2,6,6-trimethyl-1-cyclohexen-1-yl) -2,4,6,8-nonatetraenoic acid), an inhibitor of AP-1 activation in a dose of 1 mg / kg intraperitoneally 3 times a week. It has been revealed that the SR 11302 administration restores the mechanism of NO autoregulation in the femoral bones during the sodium fluoride and sodium nitrate co- administration, reducing the total activity of NO synthase and activity of its inducible isoform under a reciprocal increase in total arginase activity, and suppresses the peroxynitrite production. This is accompanied by a decrease in the activity of enzymes, which are known as markers of bone resorption (acid phosphatase and its bone isoform) and restriction of the depolymerization of collagen, proteoglycans and sialoglycoproteins of the connective (bone) tissue in the femurs and vertebrae. Moreover, the introduction of SR 11302 under the experimental conditions is accompanied by an increase in the density and mineral saturation of the femurs and vertebrae, and an improvement in the biomechanical characteristics of the femurs (their strength and elasticity).

Assessment of the global chromatin landscape and transcriptome of peripheral iNKT cell subsets

Abstract Vα14i invariant Natural Killer T (iNKT) cells are important modulators of immune responses. They differentiate into three effector cell subsets in the thymus, NKT1, NKT2, and NKT17, which resemble Th1, Th2, and Th17 CD4 T cells. After exiting the thymus, iNKT cells localize to tissues and do not recirculate, but the impact of tissue localization on the epigenetic landscape and transcriptome of each subset is not known. We assessed global chromatin accessibility and transcriptional activity using ATACseq and RNAseq in iNKT cell subsets isolated from the thymus, spleen, liver, and lung. By comparing iNKT cell subsets within each tissue, we found over 5,000 differentially accessible regions of chromatin. This is consistent with previous analyses showing great differences in the transcriptomes of the thymic iNKT cell subsets. Interestingly, relatively limited differences in the accessible chromatin or transcriptome were observed when comparing the same subset from different sites, e.g., NKT1 cells from different tissues. An exception is the unique set of accessible chromatin regions and transcripts identified in all iNKT cell subsets in the lung. Lung iNKT cells exhibited features of increased AP-1 transcription factor activity, which has been correlated with both activation and tissue residency, found in other lung lymphocyte populations. After antigen challenge, an iNKT cell subset with features similar to T follicular helper cells is abundant; these cells are highly different from the other subsets. Taken together, these data indicate that the epigenome and transcriptome of iNKT cells is highly impacted by subset decision, and much less by tissue localization, although dynamic changes occur after antigen exposure.

Identification of a novel role of IL-13R\u03b12 in human Glioblastoma multiforme: interleukin-13 mediates signal transduction through AP-1 pathway

BackgroundPreviously, we have demonstrated that Interleukin 13 receptor alpha 2 (IL-13Rα2) is overexpressed in approximate 78% Glioblastoma multiforme (GBM) samples. We have also demonstrated that IL-13Rα2 can serve as a target for cancer immunotherapy in several pre-clinical and clinical studies. However, the significance of overexpression of IL-13Rα2 in GBM and astrocytoma and signaling through these receptors is not known. IL-13 can signal through IL-13R via JAK/STAT and AP-1 pathways in certain cell lines including some tumor cell lines. Herein, we have investigated a role of IL-13/IL-13Rα2 axis in signaling through AP-1 transcription factors in human glioma samples in situ.MethodsWe examined the activation of AP-1 family of transcription factors (c-Jun, Fra-1, Jun-D, c-Fos, and Jun-B) after treating U251, A172 (IL-13Rα2 +ve) and T98G (IL-13Rα2 −ve) glioma cell lines with IL-13 by RT-qPCR, and immunocytochemistry (ICC). We also performed colorimetric ELISA based assay to determine AP-1 transcription factor activation in glioma cell lines. Furthermore, we examined the expression of AP-1 transcription factors in situ in GBM and astrocytoma specimens by multiplex-immunohistochemistry (IHC). Student t test and ANOVA were used for statistical analysis of the results.ResultsWe have demonstrated up-regulation of two AP-1 transcription factors (c-Jun and Fra-1) at mRNA and protein levels upon treatment with IL-13 in IL-13Rα2 positive but not in IL-13Rα2 negative glioma cell lines. Both transcription factors were also overexpressed in patient derived GBM specimens, however, in contrast to GBM cell lines, c-Fos is also overexpressed in patient derived specimens. Astrocytoma specimens showed lesser extent of immunostaining for IL-13Rα2 and three AP-1 factors compared to GBM specimens. By transcription factor activation assay, we demonstrated that AP-1 transcription factors (C-Jun and Fra-1) were activated upon treatment of IL-13Rα2 + GBM cell lines but not IL-13Rα2 − GBM cell line with IL-13. Our results demonstrate functional activity of AP-1 transcription factor in GBM cell lines in response to IL-13.ConclusionsThese results indicate that IL-13/IL-13Rα2 axis can mediate signal transduction in situ via AP-1 pathway in GBM and astrocytoma and may serve as a new target for GBM immunotherapy.

Holding All the CARDs: How MALT1 Controls CARMA/CARD-Dependent Signaling.

The scaffold proteins CARMA1-3 (encoded by the genes CARD11, -14 and -10) and CARD9 play major roles in signaling downstream of receptors with immunoreceptor tyrosine activation motifs (ITAMs), G-protein coupled receptors (GPCR) and receptor tyrosine kinases (RTK). These receptors trigger the formation of oligomeric CARMA/CARD-BCL10-MALT1 (CBM) complexes via kinases of the PKC family. The CBM in turn regulates gene expression by the activation of NF-κB and AP-1 transcription factors and controls transcript stability. The paracaspase MALT1 is the only CBM component having an enzymatic (proteolytic) activity and has therefore recently gained attention as a potential drug target. Here we review recent advances in the understanding of the molecular function of the protease MALT1 and summarize how MALT1 scaffold and protease function contribute to the transmission of CBM signals. Finally, we will highlight how dysregulation of MALT1 function can cause pathologies such as immunodeficiency, autoimmunity, psoriasis, and cancer.

Epsin deficiency promotes lymphangiogenesis through regulation of VEGFR3 degradation in diabetes.

Impaired lymphangiogenesis is a complication of chronic complex diseases, including diabetes. VEGF-C/VEGFR3 signaling promotes lymphangiogenesis, but how this pathway is affected in diabetes remains poorly understood. We previously demonstrated that loss of epsins 1 and 2 in lymphatic endothelial cells (LECs) prevented VEGF-C-induced VEGFR3 from endocytosis and degradation. Here, we report that diabetes attenuated VEGF-C-induced lymphangiogenesis in corneal micropocket and Matrigel plug assays in WT mice but not in mice with inducible lymphatic-specific deficiency of epsins 1 and 2 (LEC-iDKO). Consistently, LECs isolated from diabetic LEC-iDKO mice elevated in vitro proliferation, migration, and tube formation in response to VEGF-C over diabetic WT mice. Mechanistically, ROS produced in diabetes induced c-Src-dependent but VEGF-C-independent VEGFR3 phosphorylation, and upregulated epsins through the activation of transcription factor AP-1. Augmented epsins bound to and promoted degradation of newly synthesized VEGFR3 in the Golgi, resulting in reduced availability of VEGFR3 at the cell surface. Preclinically, the loss of lymphatic-specific epsins alleviated insufficient lymphangiogenesis and accelerated the resolution of tail edema in diabetic mice. Collectively, our studies indicate that inhibiting expression of epsins in diabetes protects VEGFR3 against degradation and ameliorates diabetes-triggered inhibition of lymphangiogenesis, thereby providing a novel potential therapeutic strategy to treat diabetic complications.

Ginsenoside C-Mx Isolated from Notoginseng Stem-leaf Ginsenosides Attenuates Ultraviolet B-mediated Photoaging in Human Dermal Fibroblasts.

Notoginseng is a traditional herbal medicine widely used for medicinal therapy in Asia, as it contains numerous ginsenosides with pharmacological effects. In this study, we submitted Notoginseng stem-leaf (NGL) ginsenosides to an enzyme to create a reaction with the monomer products of ginsenoside C-Mx and then investigated the ability of ginsenoside C-Mx to protect the skin against ultraviolet B-induced injury in normal human dermal fibroblasts (NHDFs). Ginsenoside C-Mx alleviated UVB-induced intracellular reactive oxygen species (ROS), MMP-1 and IL-6 expression while accelerating TGF-β and procollagen type I secretion. In addition, ginsenoside C-Mx reversed UVB-induced procollagen type I reduction by regulating the TGF-β/Smad signaling pathway. Moreover, ginsenoside C-Mx inhibited activation of AP-1 transcription factor, an inducer of MMPs. Ginsenoside C-Mx displayed an outstanding antioxidant capacity, increasing expression of cytoprotective antioxidants such as HO-1 and NQO-1 expression by enhancing the nuclear accumulation of Nrf2. Interestingly, application of ginsenoside C-Mx treatment (1, 10, 20μm) significantly diminished UVB-induced suppressed NF-κB expression, decreasing the over-released inflammatory cytokines. Taken together, our findings indicated that ginsenoside C-Mx may act as a promising natural cosmetic ingredient for prevention and treatment of UVB-induced skin damage.