Suppression of TNF-alpha-induced apoptosis by NF-kappaB

IκBα is required for full transcriptional induction of some NFκB-regulated genes in response to TNF in MCF-7 cells

Inflammatory stimuli triggers the degradation of three inhibitory κB (IκB) proteins, allowing for nuclear translocation of nuclear factor-κB (NFκB) for transcriptional induction of its target genes. Of these three, IκBα is a well-known negative feedback regulator that limits the duration of NFκB activity. We sought to determine whether IκBα's role in enabling or limiting NFκB activation is important for tumor necrosis factor (TNF)-induced gene expression in human breast cancer cells (MCF-7). Contrary to our expectations, many more TNF-response genes showed reduced induction than enhanced induction in IκBα knockdown cells. Mathematical modeling was used to investigate the underlying mechanism. We found that the reduced activation of some NFκB target genes in IκBα-deficient cells could be explained by the incoherent feedforward loop (IFFL) model. In addition, for a subset of genes, prolonged NFκB activity due to loss of negative feedback control did not prolong their transient activation; this implied a multi-state transcription cycle control of gene induction. Genes encoding key inflammation-related transcription factors, such as JUNB and KLF10, were found to be best represented by a model that contained both the IFFL and the transcription cycle motif. Our analysis sheds light on the regulatory strategies that safeguard inflammatory gene expression from overproduction and repositions the function of IκBα not only as a negative feedback regulator of NFκB but also as an enabler of NFκB-regulated stimulus-responsive inflammatory gene expression. This study indicates the complex involvement of IκBα in the inflammatory response to TNF that is induced by radiation therapy in breast cancer.

The role of the TNFα-mediated astrocyte signaling pathway in epilepsy

Epilepsy is a common disease  in the central nervous system. There is growing evidence that epilepsy is associated with glial cells, including astrocytes. Tumor necrosis factor α (TNFα) is a “master regulator” of proinflammatory cytokine production and is secreted by microglia and astrocytes. TNFα secreted by microglia can activate astrocytes. Additionally, TNFα can regulate neuron activity and induce epilepsy by increasing the glutamate release, reducing the expression of γ-aminobutyric acid, inducing neuroinflammation and affecting the synaptic function in astrocytes. This review summarizes the signaling pathways and receptors of TNFα acting on astrocytes that are related to epilepsy and provides insights into the potential therapeutic strategies of epilepsy for clinical practice.

The personalized application of biomaterials based on age and sexuality specific immune responses

Although biomaterials are widely utilized in clinics, it still follows the "one-fits-all" strategy. Biological variables such as age and sexuality have an impact on the host immune response and are not fully considered in the practice guidelines of the biomaterial implantation. In this study, we investigated the immuno-material interactions of six commonly used biomaterials (agarose, alginate, chitosan, CMC, GelMA and collagen type I) and constructed a population (with different ages and sexes) based transcriptome atlas. Protein and polysaccharide-based biomaterials elicited distinctive immune responses that protein-based materials preferred the NKT pathway to activate innate and adaptive immune response, whereas polysaccharide-based materials activated the cDCs to present antigen. The atlas further revealed the sex/age-related variabilities on the immune response followed by the polysaccharide treatment. As for sex bias, alginate and agarose stimulation significantly increased the proportion of naive CD4⁺ T cells in the female group, accompanied by the Th1 differentiation tendency, compared to the male group. Age-biased transcript showed alginate and chitosan would impair the extracellular matrix remodeling and up-regulate the apoptosis process in the elderly groups, compared to the young group. More attentions on the ingredient, age and sexuality effect of biomaterial implants should be paid during the clinical practice, especially for the polysaccharide-based materials. This experimental result is of great significance for the selection of biomaterials, particularly the blood contact materials, such as vessel or cardiac device, drug vehicles and hemostatic materials.

Comparative Study of the Pharmacological Properties and Biological Effects of Polygonum aviculare L. herba Extract-Entrapped Liposomes versus Quercetin-Entrapped Liposomes on Doxorubicin-Induced Toxicity on HUVECs

This study aimed to evaluate the comparative biological effects of Polygonum aviculare L. herba (PAH) extract and quercetin-entrapped liposomes on doxorubicin (Doxo)-induced toxicity in HUVECs. HUVECs were treated with two formulations of liposomes loaded with PAH extract (L5 and L6) and two formulations of liposomes loaded with quercetin (L3 prepared with phosphatidylcholine and L4 prepared with phosphatidylserine). The results obtained with atomic force microscopy, zeta potential and entrapment liposome efficiency confirmed the interactions of the liposomes with PAH or free quercetin and a controlled release of flavonoids entrapped in all the liposomes. Doxo decreased the cell viability and induced oxidative stress, inflammation, DNA lesions and apoptosis in parallel with the activation of Nrf2 and NF-kB. Free quercetin, L3 and L4 inhibited the oxidative stress and inflammation and reduced apoptosis, particularly L3. Additionally, these compounds diminished the Nrf2 and NF-kB expressions and DNA lesions, principally L4. PAH extract, L5 and L6 exerted antioxidant and anti-inflammatory activities, reduced γH2AX formation and inhibited extrinsic apoptosis and transcription factors activation but to a lesser extent. The loading of quercetin in liposomes increased the cell viability and exerted better endothelial protection compared to free quercetin, especially L3. The liposomes with PAH extract had moderate efficiency, mainly due to the antioxidant and anti-inflammatory effects and the inhibition of extrinsic apoptosis.

[Immunomodulation in Cholesteatoma]

INTRODUCTION

The etiopathogenesis of chronic otitis media epitympanalis/cholesteatoma and its proliferative destructive course with possible complications such as destruction of bony structures with hearing loss, vestibular dysfunction, facial nerve paralysis and intracranial complications are still unexplained. Surgery is still the way to go. New studies are increasingly looking at the innate immune system.

METHODS

Our studies were carried out in a mouse model in WT mice and immundeficient KO-mice, as well as in cholestatoma and healthy ear canal skin and middle ear tissue, which was removed during ear surgery. The expression analyses were carried out at the gene and protein level using TNF as the major target for therapy evaluation. By means of TUNEL staining and immunohistochemistry the level of apoptosis was evaluated.

RESULTS

The uncontrolled undirected cholesteatoma growth shows an immunomodulatory profile with up and down-regulation of various gene networks, especially those involved in TNF downstream and upstream signaling pathways. TNF in cholesteatoma is modulated both inflammatorily and apoptotically and therefore is suitable as a possible therapeutic approach in various models.

CONCLUSIONS

Cholestatoma might be immunomodulatory regulated.

Evidence That Tumor Microenvironment Initiates Epithelial-To-Mesenchymal Transition and Calebin A can Suppress it in Colorectal Cancer Cells

Background: Tumor microenvironment (TME) has a pivotal impact on tumor progression, and epithelial-mesenchymal transition (EMT) is an extremely crucial initial event in the metastatic process in colorectal cancer (CRC) that is not yet fully understood. Calebin A (an ingredient in Curcuma longa) has been shown to repress CRC tumor growth. However, whether Calebin A is able to abrogate TME-induced EMT in CRC was investigated based on the underlying pathways. Methods: CRC cell lines (HCT116, RKO) were exposed with Calebin A and/or a FAK inhibitor, cytochalasin D (CD) to investigate the action of Calebin A in TME-induced EMT-related tumor progression. Results: TME induced viability, proliferation, and increased invasiveness in 3D-alginate CRC cultures. In addition, TME stimulated stabilization of the master EMT-related transcription factor (Slug), which was accompanied by changes in the expression patterns of EMT-associated biomarkers. Moreover, TME resulted in stimulation of NF-κB, TGF-β1, and FAK signaling pathways. However, these effects were dramatically reduced by Calebin A, comparable to FAK inhibitor or CD. Finally, TME induced a functional association between NF-κB and Slug, suggesting that a synergistic interaction between the two transcription factors is required for initiation of EMT and tumor cell invasion, whereas Calebin A strongly inhibited this binding and subsequent CRC cell migration. Conclusion: We propose for the first time that Calebin A modulates TME-induced EMT in CRC cells, at least partially through the NF-κB/Slug axis, TGF-β1, and FAK signaling. Thus, Calebin A appears to be a potential agent for the prevention and management of CRC.

Novel Insights into YB-1 Signaling and Cell Death Decisions

YB-1 belongs to the evolutionarily conserved cold-shock domain protein family of RNA binding proteins. YB-1 is a well-known transcriptional and translational regulator, involved in cell cycle progression, DNA damage repair, RNA splicing, and stress responses. Cell stress occurs in many forms, e.g., radiation, hyperthermia, lipopolysaccharide (LPS) produced by bacteria, and interferons released in response to viral infection. Binding of the latter factors to their receptors induces kinase activation, which results in the phosphorylation of YB-1. These pathways also activate the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), a well-known transcription factor. NF-κB is upregulated following cellular stress and orchestrates inflammatory responses, cell proliferation, and differentiation. Inflammation and cancer are known to share common mechanisms, such as the recruitment of infiltrating macrophages and development of an inflammatory microenvironment. Several recent papers elaborate the role of YB-1 in activating NF-κB and signaling cell survival. Depleting YB-1 may tip the balance from survival to enhanced apoptosis. Therefore, strategies that target YB-1 might be a viable therapeutic option to treat inflammatory diseases and improve tumor therapy.

Evidence for the Role of Mitochondrial DNA Release in the Inflammatory Response in Neurological Disorders

Mitochondria are regarded as the metabolic centers of cells and are integral in many other cell processes, including the immune response. Each mitochondrion contains numerous copies of mitochondrial DNA (mtDNA), a small, circular, and bacterial-like DNA. In response to cellular damage or stress, mtDNA can be released from the mitochondrion and trigger immune and inflammatory responses. mtDNA release into the cytosol or bloodstream can occur as a response to hypoxia, sepsis, traumatic injury, excitatory cytotoxicity, or drastic mitochondrial membrane potential changes, some of which are hallmarks of neurodegenerative and mood disorders. Released mtDNA can mediate inflammatory responses observed in many neurological and mood disorders by driving the expression of inflammatory cytokines and the interferon response system. The current understanding of the role of mtDNA release in affective mood disorders and neurodegenerative diseases will be discussed.

Glutathione peroxidase-1 regulates ASK1-dependent apoptosis via interaction with TRAF2 in RIPK3-negative cancer cells

Glutathione peroxidase (GPx) is a selenocysteine-containing peroxidase enzyme that defends mammalian cells against oxidative stress, but the role of GPx signaling is poorly characterized. Here, we show that GPx type 1 (GPx1) plays a key regulatory role in the apoptosis signaling pathway. The absence of GPx1 augmented TNF-α-induced apoptosis in various RIPK3-negative cancer cells by markedly elevating the level of cytosolic H₂O₂, which is derived from mitochondria. At the molecular level, the absence of GPx1 led to the strengthened sequential activation of sustained JNK and caspase-8 expression. Two signaling mechanisms are involved in the GPx1-dependent regulation of the apoptosis pathway: (1) GPx1 regulates the level of cytosolic H₂O₂ that oxidizes the redox protein thioredoxin 1, blocking ASK1 activation, and (2) GPx1 interacts with TRAF2 and interferes with the formation of the active ASK1 complex. Inducible knockdown of GPx1 expression impaired the tumorigenic growth of MDA-MB-231 cells (>70% reduction, P = 0.0034) implanted in mice by promoting apoptosis in vivo. Overall, this study reveals the apoptosis-related signaling function of a GPx family enzyme highly conserved in aerobic organisms.

An antioxidative enzyme that plays a critical role in regulating whether cells program their own death offers a promising new target for anti-cancer therapies. Glutathione peroxidase-1 (GPX1) is involved in cleaning up reactive metabolic byproducts such as hydrogen peroxide inside cells. Sang Won Kang and colleagues at Ewha Womans University in Seoul, South Korea, showed that this stress-response enzyme also suppresses the induction of normal programmed cell death mechanisms in a variety of cancer cells. The researchers detailed the molecular partners involved in GPX1-mediated signaling inside cancer cells, and demonstrated that genetically reducing GPX1 expression dramatically reduces tumor growth in a mouse model of breast cancer. Drugs with similar inhibitory effects on GPX1 activity might therefore also help shrink tumors in human cancer patients.

Multifactorial Pathogenic Processes of Retinal Ganglion Cell Degeneration in Glaucoma towards Multi-Target Strategies for Broader Treatment Effects

Glaucoma is a chronic neurodegenerative disease characterized by apoptosis of retinal ganglion cell (RGC) somas, degeneration of axons, and loss of synapses at dendrites and axon terminals. Glaucomatous neurodegeneration encompasses multiple triggers, multiple cell types, and multiple molecular pathways through the etiological paths with biomechanical, vascular, metabolic, oxidative, and inflammatory components. As much as intrinsic responses of RGCs themselves, divergent responses and intricate interactions of the surrounding glia also play decisive roles for the cell fate. Seen from a broad perspective, multitarget treatment strategies have a compelling pathophysiological basis to more efficiently manipulate multiple pathogenic processes at multiple injury sites in such a multifactorial neurodegenerative disease. Despite distinct molecular programs for somatic and axonal degeneration, mitochondrial dysfunction and glia-driven neuroinflammation present interdependent processes with widespread impacts in the glaucomatous retina and optic nerve. Since dysfunctional mitochondria stimulate inflammatory responses and proinflammatory mediators impair mitochondria, mitochondrial restoration may be immunomodulatory, while anti-inflammatory treatments protect mitochondria. Manipulation of these converging routes may thus allow a unified treatment strategy to protect RGC axons, somas, and synapses. This review presents an overview of recent research advancements with emphasis on potential treatment targets to achieve the best treatment efficacy to preserve visual function in glaucoma.

Structural characteristics and immune-enhancing activity of an extracellular polysaccharide produced by marine Halomonas sp. 2E1

Microbial polysaccharides from extreme environments, such as cold seeps and hydrothermal vents, usually exhibit novel structural features and diverse biological activities. In this study, an exopolysaccharide (EPS2E1) was isolated from cold-seep bacterium Halomonas sp. 2E1 and its immune-enhancing activity was evaluated. The total sugar content and protein content were determined as 83.1% and 7.9%, respectively. EPS2E1 contained mannose and glucose with the molar ratio of 3.76: 1. The molecular weight was determined to be 47.0 kDa. Structural analysis indicated that EPS2E1 was highly branched, the backbone mainly consisted of →2)-Man-(α-1→ and →2, 6)-Man-(α-1→ with the ratio of 2.45: 1.00. The chain also contained →4)-Glc-(α-1→, →6)-Man-(α-1→ and →3)-Glc-(β-1→. EPS2E1 could significantly increase the production of NO, COX-2, TNF-α, IL-1β and IL-6 by activating the MAPK and NF-κB pathways on RAW264.7 macrophages. EPS2E1 exhibits the potential to be an immunopotentiator in the near future.

Matrix compliance permits NF-κB activation to drive therapy resistance in breast cancer

Triple-negative breast cancers (TNBCs) are associated with poor survival mediated by treatment resistance. TNBCs are fibrotic, yet little is known regarding how the extracellular matrix (ECM) evolves following therapy and whether it impacts treatment response. Analysis revealed that while primary untreated TNBCs are surrounded by a rigid stromal microenvironment, chemotherapy-resistant residual tumors inhabit a softer niche. TNBC organoid cultures and xenograft studies showed that organoids interacting with soft ECM exhibit striking resistance to chemotherapy, ionizing radiation, and death receptor ligand TRAIL. A stiff ECM enhanced proapoptotic JNK activity to sensitize cells to treatment, whereas a soft ECM promoted treatment resistance by elevating NF-κB activity and compromising JNK activity. Treatment-resistant residual TNBCs residing within soft stroma had elevated activated NF-κB levels, and disengaging NF-κB activity sensitized tumors in a soft matrix to therapy. Thus, the biophysical properties of the ECM modify treatment response, and agents that modulate stiffness-dependent NF-κB or JNK activity could enhance therapeutic efficacy in patients with TNBC.

The regulation of necroptosis by post-translational modifications

Necroptosis is a caspase-independent, lytic form of programmed cell death whose errant activation has been widely implicated in many pathologies. The pathway relies on the assembly of the apical protein kinases, RIPK1 and RIPK3, into a high molecular weight cytoplasmic complex, termed the necrosome, downstream of death receptor or pathogen detector ligation. The necrosome serves as a platform for RIPK3-mediated phosphorylation of the terminal effector, the MLKL pseudokinase, which induces its oligomerization, translocation to, and perturbation of, the plasma membrane to cause cell death. Over the past 10 years, knowledge of the post-translational modifications that govern RIPK1, RIPK3 and MLKL conformation, activity, interactions, stability and localization has rapidly expanded. Here, we review current knowledge of the functions of phosphorylation, ubiquitylation, GlcNAcylation, proteolytic cleavage, and disulfide bonding in regulating necroptotic signaling. Post-translational modifications serve a broad array of functions in modulating RIPK1 engagement in, or exclusion from, cell death signaling, whereas the bulk of identified RIPK3 and MLKL modifications promote their necroptotic functions. An enhanced understanding of the modifying enzymes that tune RIPK1, RIPK3, and MLKL necroptotic functions will prove valuable in efforts to therapeutically modulate necroptosis.

Phenotypic and Functional Alterations of Immune Effectors in Periodontitis; A Multifactorial and Complex Oral Disease

Survival and function of immune subsets in the oral blood, peripheral blood and gingival tissues of patients with periodontal disease and healthy controls were assessed. NK and CD8 + T cells within the oral blood mononuclear cells (OBMCs) expressed significantly higher levels of CD69 in patients with periodontal disease compared to those from healthy controls. Similarly, TNF-α release was higher from oral blood of patients with periodontal disease when compared to healthy controls. Increased activation induced cell death of peripheral blood mononuclear cells (PBMCs) but not OBMCs from patients with periodontal disease was observed when compared to those from healthy individuals. Unlike those from healthy individuals, OBMC-derived supernatants from periodontitis patients exhibited decreased ability to induce secretion of IFN-γ by allogeneic healthy PBMCs treated with IL-2, while they triggered significant levels of TNF-α, IL-1β and IL-6 by untreated PBMCs. Interaction of PBMCs, or NK cells with intact or NFκB knock down oral epithelial cells in the presence of a periodontal pathogen, F. nucleatum, significantly induced a number of pro-inflammatory cytokines including IFN-γ. These studies indicated that the relative numbers of immune subsets obtained from peripheral blood may not represent the composition of the immune cells in the oral environment, and that orally-derived immune effectors may differ in survival and function from those of peripheral blood.

Immunopathology of Type 1 Diabetes and Immunomodulatory Effects of Stem Cells: A Narrative Review of the Literature

Type 1 Diabetes (T1D) is a complex autoimmune disorder which occurs as a result of an intricate series of pathologic interactions between pancreatic β-cells and a wide range of components of both the innate and the adaptive immune systems. Stem-cell therapy, a recently-emerged potentially therapeutic option for curative treatment of diabetes, is demonstrated to cause significant alternations to both different immune cells such as macrophages, natural killer (NK) cells, dendritic cells, T cells, and B cells and non-cellular elements including serum cytokines and different components of the complement system. Although there exists overwhelming evidence indicating that the documented therapeutic effects of stem cells on patients with T1D is primarily due to their potential for immune regulation rather than pancreatic tissue regeneration, to date, the precise underlying mechanisms remain obscure. On the other hand, immune-mediated rejection of stem cells remains one of the main obstacles to regenerative medicine. Moreover, the consequences of efferocytosis of stem-cells by the recipients' lung-resident macrophages have recently emerged as a responsible mechanism for some immune-mediated therapeutic effects of stem-cells. This review focuses on the nature of the interactions amongst different compartments of the immune systems which are involved in the pathogenesis of T1D and provides explanation as to how stem cell-based interventions can influence immune system and maintain the physiologic equilibrium.

Fueling the Fire: Inflammatory Forms of Cell Death and Implications for Cancer Immunotherapy

Unleashing the immune system with immune checkpoint inhibitors (ICI) has significantly improved overall survival for subsets of patients with stage III/IV cancer. However, many tumors are nonresponsive to ICIs, in part due to a lack of tumor-infiltrating lymphocytes (TIL). Converting these immune "cold" tumors to "hot" tumors that are thus more likely to respond to ICIs is a major obstacle for cancer treatment. Triggering inflammatory forms of cell death, such as necroptosis and pyroptosis, may alter the tumor immune microenvironment and the influx of TILs. We present an emerging view that promoting tumor-localized necroptosis and pyroptosis may ultimately enhance responses to ICI. SIGNIFICANCE: Many tumor types respond poorly to ICIs or respond but subsequently acquire resistance. Effective therapies for ICI-nonresponsive tumors are lacking and should be guided by evidence from preclinical studies. Promoting inflammatory cell death mechanisms within the tumor may alter the local immune microenvironment toward an ICI-responsive state.

Regulation of distinct caspase-8 functions in retinal ganglion cells and astroglia in experimental glaucoma

Retinal ganglion cells (RGCs) expanding from the retina to the brain are primary victims of neurodegeneration in glaucoma, a leading cause of blindness; however, the neighboring astroglia survive the glaucoma-related stress and promote neuroinflammation. In light of diverse functions of caspase-8 in apoptosis, cell survival, and inflammation, this study investigated the importance of caspase-8 in different fates of glaucomatous RGCs and astroglia using two experimental approaches in parallel. In the first approach, cell type-specific responses of RGCs and astroglia to a caspase-8 cleavage-inhibiting pharmacological treatment were studied in rat eyes with or without experimentally induced glaucoma. The second approach utilized an experimental model of glaucoma in mice in which astroglial caspase-8 was conditionally deleted by cre/lox. Findings of these experiments revealed cell type-specific distinct processes that regulate caspase-8 functions in experimental glaucoma, which are involved in inducing the apoptosis of RGCs and promoting the survival and inflammatory responses of astroglia. Deletion of caspase-8 in astroglia protected RGCs against glia-driven inflammatory injury, while the inhibition of caspase-8 cleavage inhibited apoptosis in RGCs themselves. Various caspase-8 functions impacting both RGC apoptosis and astroglia-driven neuroinflammation may suggest the multi-target potential of caspase-8 regulation to provide neuroprotection and immunomodulation in glaucoma.

Autophagy protects tumors from T cell–mediated cytotoxicity via inhibition of TNFα-induced apoptosis

Although T cell checkpoint inhibitors have transformed the treatment of cancer, the molecular determinants of tumor cell sensitivity to T cell–mediated killing need further elucidation. Here, we describe a mouse genome–scale CRISPR knockout screen that identifies tumor cell TNFα signaling as an important component of T cell–induced apoptosis, with NF-κB signaling and autophagy as major protective mechanisms. Knockout of individual autophagy genes sensitized tumor cells to killing by T cells that were activated via specific TCR or by a CD3 bispecific antibody. Conversely, inhibition of mTOR signaling, which results in increased autophagic activity, protected tumor cells from T cell killing. Autophagy functions at a relatively early step in the TNFα signaling pathway, limiting FADD-dependent caspase-8 activation. Genetic inactivation of tumor cell autophagy enhanced the efficacy of immune checkpoint blockade in mouse tumor models. Thus, targeting the protective autophagy pathway might sensitize tumors to T cell–engaging immunotherapies in the clinic.

Obesity, Inflammation, and Advanced Prostate Cancer

Obesity is associated with high-grade and advanced prostate cancer. While this association may be multi-factorial, studies suggest that obesity-induced inflammation may play a role in the progression of advanced prostate cancer. The microenvironment associated with obesity increases growth factors and pro-inflammatory cytokines which have been implicated mechanistically to promote invasion, metastasis, and androgen-independent growth. This review summarizes recent findings related to obesity-induced inflammation which may be the link to advanced prostate cancer. In addition, this review while introduce novel targets to mitigate prostate cancer metastasis to the bone. Specific emphasis will be placed on the role of the pro-inflammatory cytokines interleukin (IL)-6, tumor necrosis factor (TNF)α, and IL-1β.

The ARF tumor suppressor targets PPM1G/PP2Cγ to counteract NF-κB transcription tuning cell survival and the inflammatory response

Inducible transcriptional programs mediate the regulation of key biological processes and organismal functions. Despite their complexity, cells have evolved mechanisms to precisely control gene programs in response to environmental cues to regulate cell fate and maintain normal homeostasis. Upon stimulation with proinflammatory cytokines such as tumor necrosis factor-α (TNF), the master transcriptional regulator nuclear factor (NF)-κB utilizes the PPM1G/PP2Cγ phosphatase as a coactivator to normally induce inflammatory and cell survival programs. However, how PPM1G activity is precisely regulated to control NF-κB transcription magnitude and kinetics remains unknown. Here, we describe a mechanism by which the ARF tumor suppressor binds PPM1G to negatively regulate its coactivator function in the NF-κB circuit thereby promoting insult resolution. ARF becomes stabilized upon binding to PPM1G and forms a ternary protein complex with PPM1G and NF-κB at target gene promoters in a stimuli-dependent manner to provide tunable control of the NF-κB transcriptional program. Consistently, loss of ARF in colon epithelial cells leads to up-regulation of NF-κB antiapoptotic genes upon TNF stimulation and renders cells partially resistant to TNF-induced apoptosis in the presence of agents blocking the antiapoptotic program. Notably, patient tumor data analysis validates these findings by revealing that loss of ARF strongly correlates with sustained expression of inflammatory and cell survival programs. Collectively, we propose that PPM1G emerges as a therapeutic target in a variety of cancers arising from ARF epigenetic silencing, to loss of ARF function, as well as tumors bearing oncogenic NF-κB activation.

Identification of a Selective RelA Inhibitor Based on DSE-FRET Screening Methods

Nuclear factor-κB (NF-κB) is an important transcription factor involved in various biological functions, including tumorigenesis. Hence, NF-κB has attracted attention as a target factor for cancer treatment, leading to the development of several inhibitors. However, existing NF-κB inhibitors do not discriminate between its subunits, namely, RelA, RelB, cRel, p50, and p52. Conventional methods used to evaluate interactions between transcription factors and DNA, such as electrophoretic mobility shift assay and luciferase assays, are unsuitable for high-throughput screening (HTS) and cannot distinguish NF-κB subunits. We developed a HTS method named DNA strand exchange fluorescence resonance energy transfer (DSE-FRET). This assay is suitable for HTS and can discriminate a NF-κB subunit. Using DSE-FRET, we searched for RelA-specific inhibitors and verified RelA inhibition for 32,955 compounds. The compound A55 (2-(3-carbamoyl-6-hydroxy-4-methyl-2-oxopyridin-1(2H)-yl) acetic acid) selectively inhibited RelA–DNA binding. We propose that A55 is a seed compound for RelA-specific inhibition and could be used in clinical applications.

Exploring Dysregulated Signaling Pathways in Cancer

Cancer cell biology takes advantage of identifying diverse cellular signaling pathways that are disrupted in cancer. Signaling pathways are an important means of communication from the exterior of cell to intracellular mediators, as well as intracellular interactions that govern diverse cellular processes. Oncogenic mutations or abnormal expression of signaling components disrupt the regulatory networks that govern cell function, thus enabling tumor cells to undergo dysregulated mitogenesis, to resist apoptosis, and to promote invasion to neighboring tissues. Unraveling of dysregulated signaling pathways may advance the understanding of tumor pathophysiology and lead to the improvement of targeted tumor therapy. In this review article, different signaling pathways and how their dysregulation contributes to the development of tumors have been discussed.

Resveratrol Suppresses Cross-Talk between Colorectal Cancer Cells and Stromal Cells in Multicellular Tumor Microenvironment: A Bridge between In Vitro and In Vivo Tumor Microenvironment Study

The interaction between tumor cells and the tumor microenvironment (TME) is an important process for the development of tumor malignancy. Modulation of paracrine cross-talk could be a promising strategy for tumor control within the TME. The exact mechanisms of multi-targeted compound resveratrol are not yet fully understood. Whether resveratrol can modulate paracrine signal transduction-induced malignancy in the multicellular-TME of colorectal cancer cells (CRC) was investigated. An in vitro model with 3D-alginate HCT116 cells in multicellular-TME cultures (fibroblast cells, T-lymphocytes) was used to elucidate the role of TNF-β, Sirt1-ASO and/or resveratrol in the proliferation, invasion and cancer stem cells (CSC) of CRC cells. We found that multicellular-TME, similar to TNF-β-TME, promoted proliferation, colony formation, invasion of CRC cells and enabled activation of CSCs. However, after co-treatment with resveratrol, the malignancy of multicellular-TME reversed to HCT116. In addition, resveratrol reduced the secretion of T-lymphocyte/fibroblast (TNF-β, TGF-β3) proteins, antagonized the T-lymphocyte/fibroblast-promoting NF-κB activation, NF-κB nuclear translocation and thus the expression of NF-κB-promoting biomarkers, associated with proliferation, invasion and survival of CSCs in 3D-alginate cultures of HCT116 cells induced by TNF-β- or multicellular-TME, but not by Sirt1-ASO, indicating the central role of this enzyme in the anti-tumor function of resveratrol. Our results suggest that in vitro multicellular-TME promotes crosstalk between CRC and stromal cells to increase survival, migration of HCT116 and the resveratrol/Sirt1 axis suppresses this loop by modulating paracrine agent secretion and NF-κB signaling. Fibroblasts and T-lymphocytes are promising targets for resveratrol in the prevention of CRC metastasis.

Transgenic inhibition of astroglial NF-κB restrains the neuroinflammatory and neurodegenerative outcomes of experimental mouse glaucoma

BACKGROUND

Glia-driven neuroinflammation promotes neuron injury in glaucoma that is a chronic neurodegenerative disease of the optic nerve and a leading cause of irreversible blindness. Although therapeutic modulation of neuroinflammation is increasingly viewed as a logical strategy to avoid inflammatory neurotoxicity in glaucoma, current understanding of the molecular regulation of neuroinflammation is incomplete, and the molecular targets for immunomodulation remains unknown. Growing datasets pointed to nuclear factor-kappaB (NF-κB), a key transcriptional activator of inflammation, which was identified to be most affected in glaucomatous astroglia. Using a cell type-specific experimental approach, this study aimed to determine the value of astroglial NF-κB as a potential treatment target for immunomodulation in experimental mouse glaucoma.

METHODS

Neuroinflammatory and neurodegenerative outcomes of experimental glaucoma were comparatively analyzed in mice with or without cre/lox-based conditional deletion of astroglial IκKβ, which is the main activating kinase involved in IκB degradation through the canonical pathway of NF-κB activation. Glial responses and the inflammatory status of the retina and optic nerve were analyzed by cell morphology and cytokine profiling, and neuron structure and function were analyzed by counting retinal ganglion cell (RGC) axons and somas and recording pattern electroretinography (PERG) responses.

RESULTS

Analysis of glial inflammatory responses showed immunomodulatory outcomes of the conditional transgenic deletion of IκKβ in astroglia. Various pro-inflammatory cytokines known to be transcriptional targets for NF-κB exhibited decreased production in IκKβ-deleted astroglia, which included TNF-α that can induce RGC apoptosis and axon degeneration during glaucomatous neurodegeneration. Indeed, transgenic modulation of inflammatory responses by astroglial IκKβ deletion reduced neurodegeneration at different neuronal compartments, including both RGC axons and somas, and protected PERG responses.

CONCLUSIONS

The findings of this study support a key role for astroglial NF-κB in neuroinflammatory and neurodegenerative outcomes of experimental glaucoma and the potential of this transcriptional regulator pathway as a glial treatment target to provide neuroprotection through immunomodulation. By pointing to a potential treatment strategy targeting the astroglia, these experimental findings are promising for future clinical translation through transgenic applications to improve the treatment of this blinding disease.

Anthocyanins Isolated from Vitis coignetiae Pulliat Enhances Cisplatin Sensitivity in MCF-7 Human Breast Cancer Cells through Inhibition of Akt and NF-κB Activation

Anthocyanins isolated from Vitis coignetiae Pulliat (Meoru in Korea) (AIMs) have various anti-cancer properties by inhibiting Akt and NF-κB which are involved in drug resistance. Cisplatin (CDDP) is one of the popular anti-cancer agents. Studies reported that MCF-7 human breast cancer cells have high resistance to CDDP compared to other breast cancer cell lines. In this study, we confirmed CDDP resistance of MCF-7 cells and tested whether AIMs can overcome CDDP resistance of MCF-7 cells. Cell viability assay revealed that MCF-7 cells were more resistant to CDDP treatment than MDA-MB-231 breast cancer cells exhibiting aggressive and high cancer stem cell phenotype. AIMs significantly augmented the efficacy of CDDP with synergistic effects on MCF-7 cells. Molecularly, Western blot analysis revealed that CDDP strongly increased Akt and moderately reduced p-NF-κB and p-IκB and that AIMs inhibited CDDP-induced Akt activation, and augmented CDDP-induced reduction of p-NF-κB and p-IκB in MCF-7 cells. In addition, AIMs significantly downregulated an anti-apoptotic protein, XIAP, and augmented PARP-1 cleavage in CDDP-treated MCF-7 cells. Moreover, under TNF-α treatment, AIMs augmented CDDP efficacy with inhibition of NF-κB activation on MCF-7 cells. In conclusion, AIMs enhanced CDDP sensitivity by inhibiting Akt and NF-κB activity of MCF-7 cells that show relative intrinsic CDDP resistance.

YB-1 Mediates TNF-Induced Pro-Survival Signaling by Regulating NF-κB Activation

Cell fate decisions regulating survival and death are essential for maintaining tissue homeostasis; dysregulation thereof can lead to tumor development. In some cases, survival and death are triggered by the same receptor, e.g., tumor necrosis factor (TNF)-receptor 1 (TNFR1). We identified a prominent role for the cold shock Y-box binding protein-1 (YB-1) in the TNF-induced activation and nuclear translocation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65. In the absence of YB-1, the expression of TNF receptor-associated factor 2 (TRAF2), a central component of the TNF receptor signaling complex required for NF-κB activation, is significantly reduced. Therefore, we hypothesized that the loss of YB-1 results in a destabilization of TRAF2. Consistent with this hypothesis, we observed that YB-1-deficient cells were more prone to TNF-induced apoptotic cell death. We observed enhanced effector caspase-3 activation and could successfully rescue the cells using the pan-caspase inhibitor zVAD-fmk, but not necrostatin-1. Taken together, our results indicate that YB-1 plays a central role in promoting cell survival through NF-κB activation and identifies a novel mechanism by which enhanced YB-1 expression may contribute to tumor development.

Toxic Epidermal Necrolysis and Steven-Johnson Syndrome: A Comprehensive Review

Significance: Toxic epidermal necrolysis (TEN) and Steven-Johnson syndrome (SJS) are potentially fatal acute mucocutaneous vesiculobullous disorders. Evidence to date suggests that outcomes for patients with both TEN and SJS are largely dependent on stopping the causative agent, followed by supportive care and appropriate wound management in a specialized burns unit. These are life-threatening conditions characterized by widespread full-thickness cutaneous and mucosal necrosis. This article outlines the approach to holistic management of such patients, in a specialized unit, highlighting various practical aspects of wound care to prevent complications such as infection, mucosal and adhesions, and ocular scaring. Recent Advances: There is improved understanding of pain and morbidity with regard to the type and frequency of dressing changes. More modern dressings, such as nanocrystalline, are currently favored as they may be kept in situ for longer periods. The most recent evidence on systemic agents, such as corticosteroids and cyclosporine, and novel treatments, are also discussed. Critical Issues: Following cessation of the culprit trigger, management in a specialized burns unit is the most important management step. It is now understood that a multidisciplinary team is essential in the care of these patients. Following admission of such patients, dermatology, ear, nose, and throat surgery, ophthalmology, urology, colorectal surgery, and gynecology should all be consulted to prevent disease sequelae. Future Directions: Looking forward, research is aimed at achieving prospective data on the efficacy of systemic immunomodulating agents and dressing types. Tertiary centers with burns units should develop policies for such patients to ensure that the relevant teams are consulted promptly to avoid mucocutaneous complications.

Dysregulation of Cell Death in Human Chronic Inflammation

Inflammation is a fundamental biological process mediating host defense and wound healing during infections and tissue injury. Perpetuated and excessive inflammation may cause autoinflammation, autoimmunity, degenerative disorders, allergies, and malignancies. Multimodal signaling by tumor necrosis factor receptor 1 (TNFR1) plays a crucial role in determining the transition between inflammation, cell survival, and programmed cell death. Targeting TNF signaling has been proven as an effective therapeutic in several immune-related disorders. Mouse studies have provided critical mechanistic insights into TNFR1 signaling and its potential role in a broad spectrum of diseases. The characterization of patients with monogenic primary immunodeficiencies (PIDs) has highlighted the importance of TNFR1 signaling in human disease. In particular, patients with PIDs have revealed paradoxical connections between immunodeficiency, chronic inflammation, and dysregulated cell death. Importantly, studies on PIDs may help to predict beneficial effects and side-effects of therapeutic targeting of TNFR1 signaling.

The one thousand and one chaperones of the NF-κB pathway

The NF-κB pathway represents a crucial signaling mechanism in sensing and integrating a multitude of environmental and intracellular stimuli and directing a coordinated response that from the cellular level may impact on the entire organism. A plethora of chaperone proteins work at multiple steps of the pathway, from membrane receptor activation to transcription factor binding to DNA. Indeed, chaperones are required to assist protein conformational changes, to assemble supramolecular complexes and to regulate protein ubiquitination, required for pathway activation. Some chaperones acquired a role as integral components of the signaling complexes, needed for signal progression. Here we describe the chaperones involved in the NF-κB pathway and their specific roles in the different contexts.

The Balance of TNF Mediated Pathways Regulates Inflammatory Cell Death Signaling in Healthy and Diseased Tissues

Tumor necrosis factor alpha (TNF; TNFα) is a critical regulator of immune responses in healthy organisms and in disease. TNF is involved in the development and proper functioning of the immune system by mediating cell survival and cell death inducing signaling. TNF stimulated signaling pathways are tightly regulated by a series of phosphorylation and ubiquitination events, which enable timely association of TNF receptors-associated intracellular signaling complexes. Disruption of these signaling events can disturb the balance and the composition of signaling complexes, potentially resulting in severe inflammatory diseases.

Foxg1 Upregulation Enhances Neocortical Activity

Foxg1 is an ancient transcription factor gene orchestrating a number of neurodevelopmental processes taking place in the rostral brain. In this study, we investigated its impact on neocortical activity. We found that mice overexpressing Foxg1 in neocortical pyramidal cells displayed an electroencephalography (EEG) with increased spike frequency and were more prone to kainic acid (KA)-induced seizures. Consistently, primary cultures of neocortical neurons gain-of-function for Foxg1 were hyperactive and hypersynchronized. That reflected an unbalanced expression of key genes encoding for ion channels, gamma aminobutyric acid and glutamate receptors, and was likely exacerbated by a pronounced interneuron depletion. We also detected a transient Foxg1 upregulation ignited in turn by neuronal activity and mediated by immediate early genes. Based on this, we propose that even small changes of Foxg1 levels may result in a profound impact on pyramidal cell activity, an issue relevant to neuronal physiology and neurological aberrancies associated to FOXG1 copy number variations.

Preliminary study on the inhibitory effect of tumor suppressor gene KPC1 on the proliferation in gastric carcinoma cell

Background

To investigate Kip1 ubiquitination-promoting complex 1 (KPC1) expression and its relationship with NF-κB p50 in gastric cancer cell lines.

Methods

The expression of KPC1 and NF-κB p50 in tissue samples from 159 gastric cancer patients after tumor resection and normal gastric mucosa samples from 56 patients as negative controls was retrospectively studied. The relationship between KPC1, NF-κB p50, and clinicopathological factors was analyzed, and the correlation between KPC1 and cytoplasmic NF-κB p50 was determined. The expression level of KPC1 and NF-κB p50 was researched using reverse transcription (RT) polymerase chain reaction (RT-PCR) and Western blotting in 3 differentiated human gastric cancer cell lines (AGS, SGC-7901 and MGC-803).

Results

Immunohistochemistry indicated that KPC1 and NF-κB p50 expression was significantly decreased in gastric cancer cases, and the level of expression varied across the differentiated gastric cancer tissues. KPC1 and NF-κB p50 expression was significantly connected with tumor differentiation, tumor-node-metastasis (TNM) staging, and metastasis of 159 patients suffering from gastric cancer (P<0.05), but not correlated with age and lesion size (P>0.05). KPC1 was positively connected with the expression of NF-κB p50 by the Spearman correlation analysis (r=0.427, P<0.05). The expression of KPC1 and NF-κB p50 mRNA was reduced, and there were differences in the 3 differentiated human gastric cancer cell lines, as confirmed by western blotting.

Conclusions

The co-expression of KPC1 and cytoplasmic NF-κB p50 in gastric cancer promotes tumor suppressor gene expression. Therefore, limiting the growth of tumor cells may inhibit the development of gastric cancer.

A20 and Cell Death-driven Inflammation

A20 is a potent anti-inflammatory molecule, and mutations in TNFAIP3, the gene encoding A20, are associated with a wide panel of inflammatory pathologies, both in human and mouse. The anti-inflammatory properties of A20 are commonly attributed to its ability to suppress inflammatory NF-κB signaling by functioning as a ubiquitin-editing enzyme. However, A20 also protects cells from death, independently of NF-κB regulation, and recent work has demonstrated that cell death may drive some of the inflammatory conditions caused by A20 deficiency. Adding to the fact that the protective role of A20 does not primarily rely on its catalytic activities, these findings shed new light on A20 biology.

Stress Management: Death Receptor Signalling and Cross-Talks with the Unfolded Protein Response in Cancer

Throughout tumour progression, tumour cells are exposed to various intense cellular stress conditions owing to intrinsic and extrinsic cues, to which some cells are remarkably able to adapt. Death Receptor (DR) signalling and the Unfolded Protein Response (UPR) are two stress responses that both regulate a plethora of outcomes, ranging from proliferation, differentiation, migration, cytokine production to the induction of cell death. Both signallings are major modulators of physiological tissue homeostasis and their dysregulation is involved in tumorigenesis and the metastastic process. The molecular determinants of the control between the different cellular outcomes induced by DR signalling and the UPR in tumour cells and their stroma and their consequences on tumorigenesis are starting to be unravelled. Herein, I summarize the main steps of DR signalling in relation to its cellular and pathophysiological roles in cancer. I then highlight how the UPR and DR signalling control common cellular outcomes and also cross-talk, providing potential opportunities to further understand the development of malignancies.

Clinical Pharmacokinetics and Pharmacodynamics of Bortezomib

Proteasome inhibitors disrupt multiple pathways in cells and the bone marrow microenvironment, resulting in apoptosis and inhibition of cell-cycle progression, angiogenesis, and proliferation. Bortezomib is a first-in-class proteasome inhibitor approved for the treatment of multiple myeloma and mantle cell lymphoma after one prior therapy. It is also effective in other plasma cell disorders and non-Hodgkin lymphomas. The main mechanism of action of bortezomib is to inhibit the chymotrypsin-like site of the 20S proteolytic core within the 26S proteasome, thereby inducing cell-cycle arrest and apoptosis. The pharmacokinetic profile of intravenous bortezomib is characterized by a two-compartment model with a rapid initial distribution phase followed by a longer elimination phase and a large volume of distribution. Bortezomib is available for subcutaneous and intravenous administration. Pharmacokinetic studies comparing subcutaneous and intravenous bortezomib demonstrated that systemic exposure was equivalent for both routes; pharmacodynamic parameters of 20S proteasome inhibition were also similar. Renal impairment does not influence the intrinsic pharmacokinetics of bortezomib. However, moderate or severe hepatic impairment causes an increase in plasma concentrations of bortezomib. Therefore, patients with moderate or severe hepatic impairment should start at a reduced dose. Because bortezomib undergoes extensive metabolism by hepatic cytochrome P450 3A4 and 2C19 enzymes, certain strong cytochrome P450 3A4 inducers and inhibitors can also alter the systemic exposure of bortezomib. This article critically reviews and summarizes the clinical pharmacokinetics and pharmacodynamics of bortezomib at various dosing levels and routes of administration as well as in specific patient subsets. In addition, we discuss the clinical efficacy and safety of bortezomib.

Beta HPV Type 15 Can Interfere With NF-κB Activity and Apoptosis in Human Keratinocytes

E7 protein from cutaneous as well as mucosal HPV types can alter NF-κB activity. Conflicting literature data show a HPV-induced up- or down-regulation of the NF-κB pathway in different cell lines. In a previous study we detected the expression of E7 gene of HPV15 in a subungual tumor of a patient affected by incontinentia pigmenti (IP). IP is a rare X-linked genodermatosis in which the IKKγ gene is altered. From observations in transgenic IKKγ defective mice, it was suggested that IKK-deficient cells may undergo rapid hyper-proliferation and apoptosis/necrosis, leading to increased pro-inflammatory cytokine production in the neighboring IKK-positive cells. The objective of this study was to ascertain if beta HPV 15 can alter apoptosis and NF-κB pathway in normal and IKKγ-deficient keratinocytes. The human immortalized keratinocyte cell line (HaCaT), and human primary keratinocyte (HPK) cells were transduced with a retrovirus expressing E6–E7 proteins of HPV 15 and IKKγ was successful silenced mimicking the HPV15 infection and IP. HPV15 E6–E7 gene expression improved NF-κB activity in human keratinocytes even when IKKγ was silenced by siRNA. In IKKγ silenced keratinocyte cells, TNF-α-induced apoptosis was strongly reduced by the expression of HPV15 E6–E7 genes. Beta HPV15 exerted this anti-apoptotic activity by decreasing pro-apoptotic BAK and cleaved Caspase 3 proteins. In conclusion, we can speculate that presence of persistent infection by beta papillomavirus might influence the biological fate of IP by altering NF-κB activation and apoptosis in IKKγ mutated cells, favoring their survival and possibly the development of tumors in the late stage of disease. Taken together, our data reinforce the importance of host genetic background in the pathogenesis of HPV-associated skin lesions.

The role of inflammation in a rat model of chronic thromboembolic pulmonary hypertension induced by carrageenan

Background

Chronic thromboembolic pulmonary hypertension (CTEPH) is a life-threatening condition arising from the thrombus and obstructive remodeling of the pulmonary arteries, which causes a significant morbidity and mortality. Although the modern treatment in CTEPH has been significant advanced both in surgical and medical treatment, none can claim to cure the disease, largely because of our limited understanding of the underlying pathogenesis of the disease and lack of a reliable CTEPH animal model to study for. Recently, inflammation has been accepted as a common pathway through which various risk factors trigger venous thrombo-embolism (VTE) formation, we describe a novel mouse model of CTEPH which reproduces a frequent trigger and resembles the time course, histological features, and clinical presentation of CTEPH in humans, to open a new horizons of inflammation in CTEPH.

Methods

By administering a pulmonary embolism (PE) protocol (comprising 3 sequential left jugular vein injections of autologous blood clots) to 8-week-old male Sprague Dawley (SD) rats using tranexamic acid (200 mg/kg^.d) to inhibit fibrinolysis and injecting additional carrageenan (20 mg/kg, once a week) to create perivascular inflammation, we successfully generated a CTEPH animal model. By monitoring the mean pulmonary artery pressure (mPAP) and the histopathological change to evaluate the CTEPH model. By detecting the RT-PCR, western blot, TUNEL, and immunohistochemistry in the sub-groups to find the potential mechanism of inflammation may work in the pulmonary vascular remolding.

Results

In this study, rats with CTEPH exhibited pronounced pulmonary vascular remolding with higher vessel wall area/total area (WA/TA) ratio in comparison to the control rats (85.41%±7.37% vs. 76.41%±5.97%, P<0.05), the mPAP (25.51±1.13 vs. 15.92±1.13 mmHg, P<0.05). Significant differences in mean pulmonary artery pressure (mPAP) values were observed between rats injected solely with clots and those injected with both clots and carrageenan (25.51±1.13 vs. 29.82±1.26 mmHg, P<0.05, respectively). Furthermore, following the third embolization, thrombi and intimal hyperplasia occurred in the pulmonary artery. In addition, repeated embolization elevated mRNA and protein levels of tumor necrosis factor-α (TNF-α), NF-κB/p65, and B-cell lymphoma-2 (BCL-2), but decreased BAX expression in a time-dependent manner.

Conclusions

Take advantage of the inflammation to trigger VTE formation, we successfully generated a CTEPH animal model. Inflammation may play a crucial role in the pathogenesis and progression of CTEPH by inhibiting endothelial cell apoptosis. Understanding the role of inflammation in CTEPH may not only help to determine the optimal treatment options but also may aid in the development of future preventative strategies, since current anticoagulation treatment regimens are not designed to inhibit inflammation.

Elevated TLR5 expression in vivo and loss of NF-κΒ activation via TLR5 in vitro detected in HPV-negative oropharyngeal squamous cell carcinoma

In oropharyngeal squamous cell carcinoma (OPSCC), the expression pattern of toll-like receptors (TLRs), in comparison between human papillomavirus (HPV)-positive and -negative tumors differs. TLRs control innate immune responses by activating, among others, the nuclear factor-κΒ (NF-κΒ) signaling pathway. Elevated NF-κΒ activity is detectable in several cancers and regulates cancer development and progression. We studied TLR5 expression in 143 unselected consecutive OPSCC tumors, and its relation to HPV-DNA and p16 status, clinicopathological parameters, and patient outcome, and studied TLR5 stimulation and consecutive NF-κB cascade activation in vitro in two human OPSCC cell lines and immortalized human keratinocytes (HaCat). Clinicopathological data came from hospital registries, and TLR5 immunoexpression was evaluated by immunohistochemistry. Flagellin served to stimulate TLR5 in cultured cells, followed by analysis of the activity of the NF-κB signaling cascade with In-Cell Western for IκΒ and p-IκΒ. High TLR5 expression was associated with poor disease-specific survival in HPV-positive OPSCC, which typically shows low TLR5 immunoexpression. High TLR5 immunoexpression was more common in HPV-negative OPSCC, known for its less-favorable prognosis. In vitro, we detected NF-κΒ cascade activation in the HPV-positive OPSCC cell line and in HaCat cells, but not in the HPV-negative OPSCC cell line. Our results suggest that elevated TLR5 immunoexpression may be related to reduced NF-κΒ activity in HPV-negative OPSCC. The possible prognosis-worsening mechanisms among these high-risk OPSCC patients however, require further evaluation.

Network Pharmacology-Based Dissection of the Anti-diabetic Mechanism of Lobelia chinensis

Diabetes mellitus (DM) is a chronic inflammatory disease, and the rapidly increasing DM is becoming a major problem of global public health. Traditional Chinese medicine (TCM) has a long history of treating diabetes. It has been developed and utilized because of its good efficacy and no toxic side effects. Lobelia chinensis is a traditional whole grass herbal. With the continuous deepening of pharmacological research on TCM, the active ingredients of L. chinensis are continuously revealed, which contained the alkaloids, flavonoids, flavonoid glycosides and amino acids that have the good effects of anti-inflammatory, anti-viral and anti-diabetic. In order to further explore the targets of active ingredients and its anti-diabetic mechanism, a feasible network pharmacology analysis model based on chemical, pharmacokinetic and pharmacological data was developed by network construction method to clarify the anti-diabetic mechanism of L. chinensis. The present study conducted by gas chromatography–mass spectrometer (GC/MS), which identified 208 metabolites of L. chinensis, of which 23 ingredients may have effective pharmacological effects after absorption, distribution, metabolism, and excretion (ADME) screening. Network pharmacological analysis on the active ingredients revealed that 5-hydroxymethylfurfural in L. chinensis affects the insulin resistance signaling pathway by acting on GSK3B, TNF, and MAPK1, acacetin affects the diabetic pathway by acting on INSR, DPP4, and GSK3B, that regulate type 2 diabetes, non-insulin-dependent DM, and inflammatory diseases. These results successfully indicated the potential anti-diabetic mechanism of the active ingredients of L. chinensis.

Effects of a Diet Supplemented with Exogenous Catalase from Penicillium notatum on Intestinal Development and Microbiota in Weaned Piglets

This study aims to investigate the effects of exogenous catalase (CAT), an antioxidative enzyme from microbial cultures, on intestinal development and microbiota in weaned piglets. Seventy-two weaned piglets were allotted to two groups and fed a basal diet or a basal diet containing 2.0 g/kg exogenous CAT. Results showed that exogenous CAT increased (p < 0.05) jejunal villus height/crypt depth ratio and intestinal factors (diamine oxidase and transforming growth factor-α) concentration. Moreover, dietary CAT supplementation enhanced the antioxidative capacity, and decreased the concentration of pro-inflammatory cytokine in the jejunum mucosa. Exogenous CAT did not affect the concentration of short-chain fatty acids, but decreased the pH value in colonic digesta (p < 0.05). Interestingly, the relative abundance of Bifidobacterium and Dialister were increased (p < 0.05), while Streptococcus and Escherichia-Shigella were decreased (p < 0.05) in colonic digesta by exogenous CAT. Accordingly, decreased (p < 0.05) predicted functions related to aerobic respiration were observed in the piglets fed the CAT diet. Our study suggests a synergic response of intestinal development and microbiota to the exogenous CAT, and provides support for the application of CAT purified from microbial cultures in the feed industry.

Downregulation of ubiquitin-specific protease 2 possesses prognostic and diagnostic value and promotes the clear cell renal cell carcinoma progression

Background

Clear cell renal cell carcinoma (ccRCC), characterized by high mortality, invasion, metastasis, recurrence and drug resistance, is the most common malignant tumor of the urinary system. A clear understanding of the underlying molecular mechanisms and its role during tumorigenesis of RCC can contribute to development of prognostic and targeted therapies.

Methods

We analyzed datasets from the public database, TCGA, Oncomine, for differential expression of ubiquitin-specific protease 2 (USP2), and further investigated its relationship with the clinical stage, pathological grade and prognosis of renal cancer. We used real-time quantitative PCR and western blot analysis to validate USP2 expression in clinical samples and renal cancer cell lines. Finally, we used CCK-8 and transwell assays to determine its effects on biological functions in cells.

Results

We observed significantly lower levels of USP2 mRNA in renal cancer, relative to normal, tissues across the four datasets from the Oncomine database (P<0.001), 533 cases from TCGA database (P<0.0001) and 30 pairs of clinical samples (P<0.0001). Similarly, a decreased USP2 protein expression in ccRCC was detected following immunohistochemical (IHC) and western blot analyses. Furthermore, the aberrant expression of USP2 resulted in significant relationship with clinical stage, pathological grade and lower USP2 mRNA expression was interrelated to poor prognosis of renal cell carcinoma. USP2 acted as an independent factor for ccRCC diagnosis, with an AUC of 0.8888 (95% CI: 0.8529 to 0.9246; P<0.0001). Exogenous restoration of USP2 in ccRCC cells resulted in repression of cell proliferation, migration, and invasion.

Conclusions

Overall, these results show that USP2 acts as an anti-oncogene and an independent factor for ccRCC prognosis. Positive modulation of USP2 might lead to development of a novel strategy for ccRCC treatment.

Mechanism of pro-apoptotic action of prosthetic restorations on oral mucosa cells

PURPOSE

The aim of this study was to check the pro-apoptotic mechanism of prosthetic reconstruction on epithelial cells of the oral mucosa.

PATIENTS AND METHODS

The research was carried out on the saliva of healthy patients using prostheses. The sample swabs were stained using the May-Grünwald-Giemsa method and processed by immunohistochemistry for nuclear factor kappa B (NF-κB; p65) and caspase-3. Western blots were used to detect caspase-3, NF-κB, p53 and COX-2 expression.

RESULTS

We found an increased expression of caspase-3, NF-κB and p53 in the oral epithelial cells of patients using prosthetic restorations compared to the subjects from the control group. No differences in COX-2 expression were found between the groups. The strongest immunoreactivity and expression of caspase-3, NF-κB and p53 were observed in patients using full prosthesis for less than two years.

CONCLUSIONS

The results of the conducted research indicate that prosthetic restorations may affect the process of apoptosis of oral mucosa epithelial cells. Lack of difference in expression of COX-2 in the saliva of the studied patients suggests that apoptosis is not caused by inflammatory factors.

The hepatotoxic fluoroquinolone trovafloxacin disturbs TNF- and LPS-induced p65 nuclear translocation in vivo and in vitro

Idiosyncratic drug-induced liver injury (IDILI) is a severe disease that cannot be detected during drug development. It has been shown that hepatotoxicity of some compounds associated with IDILI becomes apparent when these are combined in vivo and in vitro with LPS or TNF. Among these compounds trovafloxacin (TVX) induced apoptosis in the liver and increased pro-inflammatory cytokines in mice exposed to LPS/TNF. The hepatocyte survival and the cytokine release after TNF/LPS stimulation relies on a pulsatile activation of NF-κB. We set out to evaluate the dynamic activation of NF-κB in response to TVX + TNF or LPS models, both in mouse and human cells. Remarkably, TVX prolonged the first translocation of NF-κB induced by TNF both in vivo and in vitro. The prolonged p65 translocation caused by TVX was associated with an increased phosphorylation of IKK and MAPKs and accumulation of inhibitors of NF-κB such as IκBα and A20 in HepG2. Coherently, TVX suppressed further TNF-induced NF-κB translocations in HepG2 leading to decreased transcription of ICAM-1 and inhibitors of apoptosis. TVX prolonged LPS-induced NF-κB translocation in RAW264.7 macrophages increasing the secretion of TNF. In summary, this study presents new, relevant insights into the mechanism of TVX-induced liver injury underlining the resemblance between mouse and human models. In this study we convincingly show that regularly used toxicity models provide a coherent view of relevant pathways for IDILI. We propose that assessment of the kinetics of activation of NF-κB and MAPKs is an appropriate tool for the identification of hepatotoxic compounds during drug development.

NF-κB/Cartilage Acidic Protein 1 Promotes Ultraviolet B Irradiation-Induced Apoptosis of Human Lens Epithelial Cells

The apoptosis of human lens epithelial cells (HLECs) is a characteristic change that occurs during the development of cataracts. Ultraviolet B (UVB) is known to induce the generation of reactive oxygen species (ROS) and apoptosis in HLECs, and thus cause cataracts. Previously, we reported the functions of cartilage acidic protein 1 (CRTAC1) in UVB-treated HLECs. However, the underlying mechanism was not known. In this study, we found that CRTAC1 expression and nuclear factor-kappa B (NF-κB) p65 nuclear translocation were elevated in capsule tissues of cataract patients in comparison with normal controls. The NF-κB inhibitor, pyrrolidine dithiocarbamate (PDTC), alleviated UVB-induced apoptosis in HLECs; while activation of NF-κB suppressed the effects of the ROS inhibitor, N-acetyl-L-cysteine (NAC), on UVB-treated HLECs. The expression and promoter activity of CRTAC1 was inhibited by PDTC and NAC. Moreover, the suppressed effects of CRTAC1 knockdown on UVB-induced ROS generation, cell apoptosis, nuclear translocation of NF-κB p65, and p38 phosphorylation were attenuated by a p38 agonist. In contrast, the p38 inhibitor abolished the promotional effects of CRTAC1 overexpression on HLECs. Taken together, our results for the first time show that NF-κB is a potential transcription factor for CRTAC1. The regulatory network involving NF-κB, CRTAC1, and p38 may therefore play an important role in cataract formation.

Quercetin improves immune function in Arbor Acre broilers through activation of NF-κB signaling pathway

Quercetin, the main component of flavonoids, has a wide range of biological actions. Quercetin can be made into a variety of additives for practice, because of the stable chemical structure and water-soluble derivatives. This study was intended to explore the effects of quercetin on immune function and its regulatory mechanism in Arbor Acre broiler to provide a practical basis for improving poultry immune function and figure out the optimum supplementation as functional feed additives. A total of 240 one-day-old healthy Arbor Acre broilers, similar in body weight, were randomly allotted to 4 treatments with 6 replicates, 10 broilers in each replicate and fed with diets containing quercetin at 0, 0.02, 0.04, and 0.06% for 6 wk. Blood and immune organs (spleen, thymus, and bursa) were collected from chickens at the end of the experiment. Growth performance, immune organs indexes, contents of serum immune molecules, splenic T lymphocyte proliferative responses, and expression of immune related genes were evaluated. The results showed that dietary quercetin had no significant effect (P > 0.05) on growth performance of broilers. Compared with control, 0.06% quercetin supplementation in diet significantly increased spleen index and thymus index (P < 0.05). It also increased the secretion of immune molecules including immunoglobulin A (IgA), interleukin-4 (IL-4) (P < 0.001), immunoglobulin M (IgM) (P = 0.007), complement component 4 (C4) (P = 0.001), and tumor necrosis factor-α (TNF-α) (P < 0.05). On the other hand, 0.02% quercetin supplementation significantly increased complement component 3 (C3) (P < 0.05). Additionally, both 0.04 and 0.06% quercetin supplementation significantly increased expression of TNF-α, TNF receptor associated factor-2 (TRAF-2), TNF receptor superfamily member 1B (TNFRSF1B), nuclear factor kappa-B p65 subunit (NF-κBp65), and interferon-γ (IFN-γ) mRNA (P < 0.05), and expression of NF-κB inhibitor-alpha (IκB-α) mRNA were significantly decreased (P < 0.05). Thus, quercetin improved immune function via NF-κB signaling pathway triggered by TNF-α.

RIPK1 Kinase-Dependent Death: A Symphony of Phosphorylation Events

The serine/threonine kinase RIPK1 has emerged as a crucial component of the inflammatory response activated downstream of several immune receptors, where it paradoxically functions as a scaffold to protect the cell from death or instead as an active kinase to promote the killing of the cell. While RIPK1 kinase-dependent cell death has revealed its physiological importance in the context of microbial infection, aberrant activation of RIPK1 is also demonstrated to promote cell death-driven inflammatory pathologies, highlighting the importance of fundamentally understanding proper RIPK1 regulation. Recent advances in the field demonstrated the crucial role of phosphorylation in the fine-tuning of RIPK1 activation and, additionally, question the exact mechanism by which RIPK1 enzymatic activity transmits the death signal.

Tumor necrosis factor-driven cell death in donor organ as a barrier to immunological tolerance

PURPOSE OF REVIEW

Regulated cell death (RCD) is likely to play a role in organ rejection but it is unclear how it may be invoked. A well-known trigger of regulated cell death is tumor necrosis factor-alpha (TNF), which activates both caspase-dependent apoptosis and caspase-independent necroptosis. TNF is best known as a pro-inflammatory cytokine because it activates NFκB and MAPK signaling to induce expression of pro-inflammatory genes.

RECENT FINDINGS

Emerging data from animal models now suggest that TNF-induced cell death can also be inflammatory. Therefore, the role of cellular demise in regulating immunity should be considered. In transplantation, TNF could have a role in cellular injury or death from ischemia reperfusion (IR) injury and this may dictate organ survival. The default response to TNF in most cells is survival, rather than death, because of the presence of cell death checkpoints. However, cells succumb to TNF-driven death when these checkpoints are disrupted, and sensitivity to death likely reflects a reduction in molecules that fortify these checkpoints. We propose that a cell's propensity to die in response to TNF may underlie allograft rejection.

SUMMARY

Genetic, epigenetic, and posttranslational control of death checkpoint regulators in donor tissues may determine graft survival. Therapeutically, drugs that prevent donor cell demise could be useful in preventing organ rejection.