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1.
Res Sq ; 2024 Feb 29.
Artigo em Inglês | MEDLINE | ID: mdl-38463956

RESUMO

Alzheimer's disease (AD) is a major progressive neurodegenerative disorder of the aging population. High post-menopausal levels of the pituitary gonadotropin follicle-stimulating hormone (FSH) are strongly associated with the onset of AD, and we have shown recently that FSH directly activates the hippocampal Fshr to drive AD-like pathology and memory loss in mice. To establish a role for FSH in memory loss, we used female 3xTg;Fshr+/+, 3xTg;Fshr+/- and 3xTg;Fshr-/- mice that were either left unoperated or underwent sham surgery or ovariectomy at 8 weeks of age. Unoperated and sham-operated 3xTg;Fshr-/- mice were implanted with 17ß-estradiol pellets to normalize estradiol levels. Morris Water Maze and Novel Object Recognition behavioral tests were performed to study deficits in spatial and recognition memory, respectively, and to examine the effects of Fshr depletion. 3xTg;Fshr+/+ mice displayed impaired spatial memory at 5 months of age; both the acquisition and retrieval of the memory were ameliorated in 3xTg;Fshr-/- mice and, to a lesser extent, in 3xTg;Fshr+/- mice- -thus documenting a clear gene-dose-dependent prevention of hippocampal-dependent spatial memory impairment. At 5 and 10 months, sham-operated 3xTg;Fshr-/- mice showed better memory performance during the acquasition and/or retrieval phases, suggesting that Fshr deletion prevented the progression of spatial memory deficits with age. However, this prevention was not seen when mice were ovariectomized, except in the 10-month-old 3xTg;Fshr-/- mice. In the Novel Object Recognition test performed at 10 months, all groups of mice, except ovariectomized 3xTg;Fshr-/- mice showed a loss of recognition memory. Consistent with the neurobehavioral data, there was a gene-dose-dependent reduction mainly in the amyloid ß40 isoform in whole brain extracts. Finally, serum FSH levels < 8 ng/mL in 16-month-old APP/PS1 mice were associated with better retrieval of spatial memory. Collectively, the data provide compelling genetic evidence for a protective effect of inhibiting FSH signaling on the progression of spatial and recognition memory deficits in mice, and lay a firm foundation for the use of an FSH-blocking agent for the early prevention of cognitive decline in postmenopausal women.

2.
Environ Sci Pollut Res Int ; 30(28): 71970-71983, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36044149

RESUMO

Bintaro is a tropical mangrove plant often used as a shade tree found in Asia, Australia, Madagascar, and the Islands of the Western Pacific Ocean. The word Bintaro is also often pinned to its closest relative species, the Cerbera odollam. Flower color is one of the distinguishing features between these two species. Human poisoning with the cardiotoxic plant Bintaro is common in Southeast Asia because it bears a fruit that yields a powerful poison that has been used for suicide and homicide, hence it is also called the "Indian suicide tree". The seeds of Bintaro contain Cerberin, a cardiac glycoside toxin of the heart that blocks the calcium ion channels in heart muscles, resulting in disruption of the heartbeat most often fatally. The bio-active compound in the kernels of Bintaro varies due to which plant possesses other properties as well. The plant may also be used for medicinal purposes as it shows many pharmaceutical properties. The seeds of the plant have auspicious anticancer properties through apoptotic activity and the leaf extract of the plant was screened for its antioxidant activities. In addition, it is also used as an insecticide, pesticide, or antifungal agent. This review highlights the Pharmaceutical, toxicological, and environmentally friendly approaches of Bintaro.


Assuntos
Apocynaceae , Suicídio , Humanos , Sementes , Frutas , Extratos Vegetais/farmacologia
3.
Elife ; 112022 09 20.
Artigo em Inglês | MEDLINE | ID: mdl-36125123

RESUMO

Pharmacological and genetic studies over the past decade have established the follicle-stimulating hormone (FSH) as an actionable target for diseases affecting millions, namely osteoporosis, obesity, and Alzheimer's disease. Blocking FSH action prevents bone loss, fat gain, and neurodegeneration in mice. We recently developed a first-in-class, humanized, epitope-specific FSH-blocking antibody, MS-Hu6, with a KD of 7.52 nM. Using a Good Laboratory Practice (GLP)-compliant platform, we now report the efficacy of MS-Hu6 in preventing and treating osteoporosis in mice and parameters of acute safety in monkeys. Biodistribution studies using 89Zr-labeled, biotinylated or unconjugated MS-Hu6 in mice and monkeys showed localization to bone and bone marrow. The MS-Hu6 displayed a ß phase t½ of 7.5 days (180 hr) in humanized Tg32 mice. We tested 217 variations of excipients using the protein thermal shift assay to generate a final formulation that rendered MS-Hu6 stable in solution upon freeze-thaw and at different temperatures, with minimal aggregation, and without self-, cross-, or hydrophobic interactions or appreciable binding to relevant human antigens. The MS-Hu6 showed the same level of "humanness" as human IgG1 in silico and was non-immunogenic in ELISpot assays for IL-2 and IFN-γ in human peripheral blood mononuclear cell cultures. We conclude that MS-Hu6 is efficacious, durable, and manufacturable, and is therefore poised for future human testing.


Assuntos
Hormônio Foliculoestimulante , Osteoporose , Animais , Epitopos/metabolismo , Excipientes , Hormônio Foliculoestimulante/metabolismo , Humanos , Imunoglobulina G/metabolismo , Interleucina-2/metabolismo , Leucócitos Mononucleares/metabolismo , Camundongos , Osteoporose/tratamento farmacológico , Distribuição Tecidual
4.
JCI Insight ; 6(12)2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34032639

RESUMO

The presence of an immunosuppressive tumor microenvironment is a major obstacle in the success of cancer immunotherapies. Because extracellular matrix components can shape the microenvironment, we investigated the role of matrix metalloproteinase 2 (MMP2) in melanoma tumorigenesis. We found that MMP2 signals proinflammatory pathways on antigen presenting cells, and this requires both TLR2 and TLR4. B16 melanoma cells that express MMP2 at baseline have slower kinetics in Tlr2-/- Tlr4-/- mice, implicating MMP2 in promoting tumor growth. Indeed, Mmp2 overexpression in B16 cells potentiated rapid tumor growth, which was accompanied by reduced intratumoral cytolytic cells and increased M2 macrophages. In contrast, knockdown of Mmp2 slowed tumor growth and enhanced T cell proliferation and NK cell recruitment. Finally, we found that these effects of MMP2 are mediated through dysfunctional DC-T cell cross-talk as they are lost in Batf3-/- and Rag2-/- mice. These findings provide insights into the detrimental role of endogenous alarmins like MMP2 in modulating immune responses in the tumor microenvironment.


Assuntos
Metaloproteinase 2 da Matriz/imunologia , Receptores Toll-Like/imunologia , Microambiente Tumoral/imunologia , Animais , Células Cultivadas , Feminino , Células HEK293 , Humanos , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores Toll-Like/genética , Receptores Toll-Like/metabolismo
5.
Int J Inf Technol ; 13(4): 1649-1657, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33969260

RESUMO

The golden rule developed by Gordon E. Moore in 1965 stands forth and upholds its perception, which is observant with trending technology and making organizations, groups and individuals extract benefits from machine. AI, Robotics, Business Intelligence, Big Data and Analytics, Edge Computing, Hyperautomation, Blockchain, Democratization, Human Augmentation, Multiexperience are technical domains and trends supporting ongoing technical progress making mankind to innovate and create superhuman capabilities leaving HRs to fight the battle of replacing technology-literate people with people-literate technology. The likeliness towards analytics and complex algorithms made a breakthrough into a creative zone extending manageable workforce with the rising trends. The primary study with 108 h of leading Service Organizations of India was made to examine the recent tools and techniques for HR analytics which are adopted by them. As we recognized that analytics is driving force for HRs to be strategic business partner and step further for transforming roles. In addition we identified the implication of analytics on various HR data and decisions made by them.

6.
Nat Rev Cancer ; 21(6): 360-378, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33907315

RESUMO

Therapeutic cancer vaccines have undergone a resurgence in the past decade. A better understanding of the breadth of tumour-associated antigens, the native immune response and development of novel technologies for antigen delivery has facilitated improved vaccine design. The goal of therapeutic cancer vaccines is to induce tumour regression, eradicate minimal residual disease, establish lasting antitumour memory and avoid non-specific or adverse reactions. However, tumour-induced immunosuppression and immunoresistance pose significant challenges to achieving this goal. In this Review, we deliberate on how to improve and expand the antigen repertoire for vaccines, consider developments in vaccine platforms and explore antigen-agnostic in situ vaccines. Furthermore, we summarize the reasons for failure of cancer vaccines in the past and provide an overview of various mechanisms of resistance posed by the tumour. Finally, we propose strategies for combining suitable vaccine platforms with novel immunomodulatory approaches and standard-of-care treatments for overcoming tumour resistance and enhancing clinical efficacy.


Assuntos
Antígenos de Neoplasias/imunologia , Vacinas Anticâncer/uso terapêutico , Tolerância Imunológica , Imunoterapia/métodos , Neoplasias/imunologia , Neoplasias/prevenção & controle , Microambiente Tumoral/imunologia , Animais , Vacinas Anticâncer/imunologia , Humanos
7.
Int Rev Cell Mol Biol ; 348: 1-68, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31810551

RESUMO

Dendritic cells (DCs) are a unique class of immune cells that act as a bridge between innate and adaptive immunity. The discovery of DCs by Cohen and Steinman in 1973 laid the foundation for DC biology, and the advances in the field identified different versions of DCs with unique properties and functions. DCs originate from hematopoietic stem cells, and their differentiation is modulated by Flt3L. They are professional antigen-presenting cells that patrol the environmental interphase, sites of infection, or infiltrate pathological tissues looking for antigens that can be used to activate effector cells. DCs are critical for the initiation of the cellular and humoral immune response and protection from infectious diseases or tumors. DCs can take up antigens using specialized surface receptors such as endocytosis receptors, phagocytosis receptors, and C type lectin receptors. Moreover, DCs are equipped with an array of extracellular and intracellular pattern recognition receptors for sensing different danger signals. Upon sensing the danger signals, DCs get activated, upregulate costimulatory molecules, produce various cytokines and chemokines, take up antigen and process it and migrate to lymph nodes where they present antigens to both CD8 and CD4 T cells. DCs are classified into different subsets based on an integrated approach considering their surface phenotype, expression of unique and conserved molecules, ontogeny, and functions. They can be broadly classified as conventional DCs consisting of two subsets (DC1 and DC2), plasmacytoid DCs, inflammatory DCs, and Langerhans cells.


Assuntos
Células Dendríticas/classificação , Células Dendríticas/citologia , Animais , Células Dendríticas/imunologia , Humanos
8.
Biosens Bioelectron ; 142: 111489, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31295710

RESUMO

Implantable medical devices have been used for real-time monitoring of physical parameters (temperature, pressure and biopotentials), sustained drug release, cardiovascular and pulmonary stents and other clinical applications. Several biocompatible materials (titanium and its alloys, aluminium, cobalt-alloys, stainless steel, poly-ethylene, polyurethanes, polyglycolide and polylactides) have been commercially used for fabricating implantable devices. However, these devices require retrieval operations after a certain period. Bioresorbable materials disintegrate gradually in vivo and their derivatives get absorbed completely in the body fluid with no residue and with minimal toxic effects, thus, eliminating the need for retrieval operations. In this article, state-of-the-art advances in materials, fabrication techniques and clinical applications of bioresorbable implantable devices are reviewed. We first discuss the bioresorbable materials (e.g., magnesium, molybdenum, tungsten, silicon, germanium, silicon dioxide, silicon nitride, silk and synthetic polymers) used in the fabrication of implantable devices. Later, an overview of processes to fabricate pressure, temperature, electrical and chemical sensors are discussed, followed by their applications as implantable devices in biomedical engineering.


Assuntos
Implantes Absorvíveis , Materiais Biocompatíveis/química , Técnicas Biossensoriais/instrumentação , Animais , Engenharia Biomédica/instrumentação , Desenho de Equipamento , Humanos
9.
Front Immunol ; 10: 725, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31024557

RESUMO

Objective: Toll-like receptor-3 agonist Poly-ICLC has been known to activate immune cells and induce HIV replication in pre-clinical experiments. In this study we investigated if Poly-ICLC could be used for disrupting HIV latency while simultaneously enhancing innate immune responses. Design: This was a randomized, placebo-controlled, double-blinded trial in aviremic, cART-treated HIV-infected subjects. Participants (n = 15) were randomized 3:1 to receive two consecutive daily doses of Poly-ICLC (1.4 mg subcutaneously) vs. placebo. Subjects were observed for adverse events, immune activation, and viral replication. Methods: Besides primary outcomes of safety and tolerability, several longitudinal immune parameters were evaluated including immune cell phenotype and function via flowcytometry, ELISA, and transcriptional profiling. PCR assays for plasma HIV-1 RNA, CD4+ T cell-associated HIV-1 RNA, and proviral DNA were performed to measure HIV reservoirs and latency. Results: Poly-ICLC was overall safe and well-tolerated. Poly-ICLC-related adverse events were Grade 1/2, with the exception of one Grade 3 neutropenia which was short-lived. Mild Injection site reactions were observed in nearly all participants in the Poly-ICLC arm. Transcriptional analyses revealed upregulation of innate immune pathways in PBMCs following Poly-ICLC treatment, including strong interferon signaling accompanied by transient increases in circulating IP-10 (CXCL10) levels. These responses generally peaked by 24-48 h after the first injection and returned to baseline by day 8. CD4+ T cell number and phenotype were unchanged, plasma viral control was maintained and no significant effect on HIV reservoirs was observed. Conclusions: These finding suggest that Poly-ICLC could be safely used for inducing transient innate immune responses in treated HIV+ subjects indicating promise as an adjuvant for HIV therapeutic vaccines. Trial Registration: www.ClinicalTrials.gov, identifier: NCT02071095.


Assuntos
Carboximetilcelulose Sódica/análogos & derivados , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Imunidade Inata/efeitos dos fármacos , Poli I-C/uso terapêutico , Polilisina/análogos & derivados , Receptor 3 Toll-Like/metabolismo , Adulto , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Carboximetilcelulose Sódica/uso terapêutico , Método Duplo-Cego , Feminino , HIV/imunologia , Infecções por HIV/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Polilisina/uso terapêutico
11.
Trends Cancer ; 4(2): 119-137, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29458962

RESUMO

Dendritic cells (DCs) are essential in immunity owing to their role in activating T cells, thereby promoting antitumor responses. Tumor cells, however, hijack the immune system, causing T cell exhaustion and DC dysfunction. Tumor-induced T cell exhaustion may be reversed through immune checkpoint blockade (ICB); however, this treatment fails to show clinical benefit in many patients. While ICB serves to reverse T cell exhaustion, DCs are still necessary to prime, activate, and direct the T cells to target tumor cells. In this review we provide a brief overview of DC function, describe mechanisms by which DC functions are disrupted by the tumor microenvironment, and highlight recent developments in DC cancer vaccines.


Assuntos
Vacinas Anticâncer/uso terapêutico , Células Dendríticas/imunologia , Neoplasias/terapia , Animais , Humanos , Neoplasias/imunologia
12.
Curr Opin Immunol ; 47: 35-43, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28732279

RESUMO

Development of therapeutic cancer vaccines has been hindered by the many pro-tumorigenic mechanisms at play in cancer patients that serve to suppress both antigen presenting cells and T cells. In face of these obstacles, cancer vaccines are most likely to promote anti-tumorigenic immune responses only when formulated with strong adjuvants, and in combination with new immune interventions designed to reverse immune suppression and exhaustion of T cells in the tumor microenvironment. Dendritic cells (DCs) are often termed 'nature's adjuvant' due to their exceptional capacity for initiating both innate and adaptive immune responses. Hence, the past decade has witnessed a flurry of activity in testing DC based immunotherapies for cancer intervention. In this review we will discuss advances in conventional adjuvants and provide insight into new adjuvants as they pertain to DC cancer therapy.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Imunoterapia Adotiva/métodos , Neoplasias/terapia , Adjuvantes Imunológicos , Animais , Apresentação de Antígeno , Células Dendríticas/transplante , Humanos , Imunidade Humoral , Ativação Linfocitária , Neoplasias/imunologia , Microambiente Tumoral
13.
Cancer Immunol Immunother ; 65(10): 1261-8, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27344341

RESUMO

A recent report from the Center for Disease Control identified melanoma as being among the highest causes of cancer-related mortalities in the USA. While interventions such as checkpoint blockade have made substantial impact in terms of improving response rates and overall survival, a significant number of patients fail to respond to treatment or become resistant to therapy. A better understanding of the tumor microenvironment in these patients becomes imperative for identifying immune suppressive mechanisms that impact the development of effective anti-tumor immune responses. We have investigated innate immune cells (dendritic cells, NK cells) in the tumor microenvironment (TME) in order to devise effective targeted anticancer immune therapies. We find that matrix metalloproteinase-2 (MMP-2), secreted from melanoma cells and stromal cells, cleaves IFNAR1 and stimulates TLR-2 on dendritic cells (DC) within the TME. Both these events independently culminate in programing the DCs to promote pro-tumorigenic TH2 T cell differentiation. In addition, we have shown that NK cells become functionally exhausted in melanoma patients. We identified the expression of Tim-3 as one of the factors responsible for NK cell exhaustion and showed that anti-Tim3 antibodies partially reversed this exhaustion. We have initiated local intervention strategies such as intra-tumoral administration of DC activating Poly-ICLC and compared the efficacy of different TLR agonists and melanoma antigens for use as combination tumor vaccine in clinical trials. Such approaches will provide a unique insight into tumor biology and will facilitate in development of highly effective and cell type-specific immune therapies.


Assuntos
Células Dendríticas/imunologia , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Imunoterapia/métodos , Células Matadoras Naturais/imunologia , Melanoma/imunologia , Células Th2/imunologia , Microambiente Tumoral , Animais , Receptor Celular 2 do Vírus da Hepatite A/genética , Humanos , Imunidade Inata , Imunoterapia/tendências , Metaloproteinase 2 da Matriz/metabolismo , Receptor de Interferon alfa e beta/metabolismo , Receptor 2 Toll-Like/metabolismo , Evasão Tumoral
14.
J Immunol ; 196(9): 3754-67, 2016 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-26969755

RESUMO

Monocytes and macrophages are important HIV reservoirs, as they exhibit marked resistance to apoptosis upon infection. However, the mechanism underlying resistance to apoptosis in these cells is poorly understood. Using HIV-viral protein R-52-96 aa peptide (Vpr), we show that primary monocytes and THP-1 cells treated with Vpr are highly susceptible to mitochondrial depolarization, but develop resistance following stimulation with bacterial DNA or CpG oligodeoxynucleotide. We have shown that Vpr-induced mitochondrial depolarization is mediated by TNFR-associated factor-1 (TRAF-1) and TRAF-2 degradation and subsequent activation of caspase-8, Bid, and Bax. To provide the mechanism governing such resistance to mitochondrial depolarization, our results show that prior stimulation with CpG oligodeoxynucleotide or Escherichia coli DNA prevented: 1) TRAF-1/2 downregulation; 2) activation of caspase-8, Bid, and Bax; and 3) subsequent mitochondrial depolarization and release of apoptosis-inducing factor and cytochrome c Furthermore, this protection was mediated by upregulation of antiapoptotic protein (c-IAP-2) through calmodulin-dependent kinase-II activation. Thus, c-IAP-2 may prevent Vpr-mediated mitochondrial depolarization through stabilizing TRAF-1/2 expression and sequential inhibition of caspase-8, Bid, and Bax.


Assuntos
DNA Bacteriano/imunologia , Proteínas Inibidoras de Apoptose/metabolismo , Macrófagos/imunologia , Monócitos/imunologia , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo , Apoptose , Proteína Agonista de Morte Celular de Domínio Interatuante com BH3/metabolismo , Caspase 8/metabolismo , Linhagem Celular , Escherichia coli/genética , Humanos , Potencial da Membrana Mitocondrial , Fator 1 Associado a Receptor de TNF/metabolismo , Fator 2 Associado a Receptor de TNF/metabolismo , Proteína X Associada a bcl-2/metabolismo
15.
J Leukoc Biol ; 96(6): 1011-22, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25225677

RESUMO

Resistance to apoptosis is an important characteristic that human macrophages acquire during differentiation from monocytes. However, the intracellular mechanisms that mediate the development of resistance are not well understood. We have used M-CSF-stimulated primary human monocytes and PMA-treated THP1 cells to study apoptosis resistance during differentiation of human macrophages. Our results indicate that PI3K/Akt distinctively regulates survival of macrophages during and after differentiation. More specifically, a signaling pathway consisting of PI3K/Akt-NF-κB-Bcl-xL regulates cell survival during the differentiation process. PI3K/Akt-mediated activation of NF-κB plays a key role in survival of differentiating macrophages by specifically sustaining antiapoptotic Bcl-xL expression. With the use of pharmacological inhibitors and siRNA for Akt and Bcl-xL, we show that in the absence of Akt-dependent Bcl-xL expression during differentiation, cells undergo caspase-mediated apoptosis. In contrast, in differentiated macrophages, Bcl-xL expression is independent of PI3K/Akt activation. Taken together, these results suggest that survival of macrophages is distinctly regulated during and after differentiation. Our results also suggest new, potential therapeutic targets to modulate differentiation and survival of this cell type.


Assuntos
Hematopoese/genética , Macrófagos/citologia , NF-kappa B/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , Transdução de Sinais/fisiologia , Proteína bcl-X/fisiologia , Antracenos/farmacologia , Apoptose/efeitos dos fármacos , Ácidos Cafeicos/farmacologia , Linhagem Celular Tumoral , Cromonas/farmacologia , Flavonoides/farmacologia , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Fator Estimulador de Colônias de Macrófagos/farmacologia , Macrófagos/efeitos dos fármacos , Monócitos/citologia , Monócitos/efeitos dos fármacos , Morfolinas/farmacologia , NF-kappa B/antagonistas & inibidores , Álcool Feniletílico/análogos & derivados , Álcool Feniletílico/farmacologia , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , RNA Interferente Pequeno/farmacologia , Sesquiterpenos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Acetato de Tetradecanoilforbol/farmacologia , Proteína bcl-X/biossíntese , Proteína bcl-X/genética
16.
Front Immunol ; 5: 327, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25071785

RESUMO

Cytosolic NOD-like receptors (NLRs) have been associated with human diseases including infections, cancer, and autoimmune and inflammatory disorders. These innate immune pattern recognition molecules are essential for controlling inflammatory mechanisms through induction of cytokines, chemokines, and anti-microbial genes. Upon activation, some NLRs form multi-protein complexes called inflammasomes, while others orchestrate caspase-independent nuclear factor kappa B (NF-κB) and mitogen activated protein kinase (MAPK) signaling. Moreover, NLRs and their downstream signaling components engage in an intricate crosstalk with cell death and autophagy pathways, both critical processes for cancer development. Recently, increasing evidence has extended the concept that chronic inflammation caused by abberant NLR signaling is a powerful driver of carcinogenesis, where it abets genetic mutations, tumor growth, and progression. In this review, we explore the rapidly expanding area of research regarding the expression and functions of NLRs in different types of cancers. Furthermore, we particularly focus on how maintaining tissue homeostasis and regulating tissue repair may provide a logical platform for understanding the liaisons between the NLR-driven inflammatory responses and cancer. Finally, we outline novel therapeutic approaches that target NLR signaling and speculate how these could be developed as potential pharmaceutical alternatives for cancer treatment.

17.
J Biol Chem ; 287(18): 15118-33, 2012 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-22403404

RESUMO

Macrophages are resistant to HIV cytopathic effects, which contributes to viral persistence and reservoir formation. HIV viral protein R (Vpr) is a potent apoptosis-inducing agent for primary monocytes. Because the biologically active Vpr is found in serum and cerebrospinal fluid of HIV-infected patients, we investigated the apoptotic effect of Vpr on monocyte-derived macrophages and phorbol 12-myristate 13-acetate-activated THP1 macrophages. Our results show that primary monocytes and THP1 cells develop resistance to Vpr-induced apoptosis following differentiation into macrophages. To determine the effect of Vpr on the expression of antiapoptotic proteins, we show that in contrast to the undifferentiated cells, Vpr did not down-regulate the expression of antiapoptotic inhibitors of apoptosis (IAPs) and Bcl2 family members in macrophages, suggesting their involvement in resistance to Vpr-induced apoptosis. However, knocking down Bcl-xL and Mcl-1 proteins induced spontaneous apoptosis with no impact on susceptibility to Vpr-induced apoptosis. In contrast, down-regulation of cellular IAP1 (cIAP1) and cIAP2 by using siRNAs and SMAC (second mitochondria-derived activator of caspases) mimetic sensitized macrophages to Vpr-induced apoptosis. Overall, our results suggest that resistance to Vpr-induced apoptosis is specifically mediated by cIAP1/2 genes independent of Bcl-xL and Mcl-1, which play a key role in maintaining cell viability. Moreover, IAP modulation may be a potential strategy to eliminate HIV persistence in macrophages.


Assuntos
Apoptose , Infecções por HIV/metabolismo , HIV-1/metabolismo , Proteínas Inibidoras de Apoptose/metabolismo , Macrófagos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína bcl-X/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo , Proteína 3 com Repetições IAP de Baculovírus , Carcinógenos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Infecções por HIV/patologia , Humanos , Macrófagos/patologia , Macrófagos/virologia , Masculino , Monócitos/metabolismo , Monócitos/patologia , Monócitos/virologia , Proteína de Sequência 1 de Leucemia de Células Mieloides , Acetato de Tetradecanoilforbol/farmacologia , Ubiquitina-Proteína Ligases
18.
J Immunol ; 187(11): 5865-78, 2011 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-22068233

RESUMO

Monocytic cells survive HIV replication and consequent cytopathic effects because of their decreased sensitivity to HIV-induced apoptosis. However, the mechanism underlying this resistance to apoptosis remains poorly understood. Lymphocytic cells are exposed to microbial products because of their translocation from the gut in persons with chronic HIV infections or following coinfections. We hypothesized that activation of monocytic cells by such microbial products through interaction with corresponding TLRs may confer antiapoptotic signals. Using HIV-viral protein R (Vpr)(52-96) peptide as a model apoptosis-inducing agent, we demonstrated that unlike monocyte-derived macrophages, undifferentiated primary human monocytes and promonocytic THP-1 cells are highly susceptible to Vpr(52-96)-induced apoptosis. Interestingly, monocytes and THP-1 cells stimulated with TLR9 agonist CpG induced almost complete resistance to Vpr(52-96)-induced apoptosis, albeit through a TLR9-independent signaling pathway. Moreover, CpG selectively induced the antiapoptotic cellular inhibitor of apoptosis (c-IAP)-2 protein and inhibition of the c-IAP-2 gene by either specific small interfering RNA or synthetic second mitochondrial activator of caspases mimetic reversed CpG-induced resistance against Vpr(52-96)-mediated apoptosis. We demonstrated that c-IAP-2 is regulated by the JNK and calcium signaling pathway, in particular calmodulin-dependent protein kinase-II. Furthermore, inhibition of JNK and the calcium signaling including the calmodulin-dependent protein kinase-II by either pharmacological inhibitors or their specific small interfering RNAs reversed CpG-induced protection against Vpr(52-96)-mediated apoptosis. We also show that CpG induced JNK phosphorylation through activation of the calcium signaling pathway. Taken together, our results suggest that CpG-induced protection may be mediated by c-IAP-2 through the calcium-activated JNK pathway via what appeared to be TLR9-independent signaling pathways.


Assuntos
Proteínas Inibidoras de Apoptose/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/imunologia , Monócitos/virologia , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/imunologia , Apoptose/imunologia , Western Blotting , Linhagem Celular , Separação Celular , Citometria de Fluxo , Humanos , Microscopia Confocal , Monócitos/metabolismo , Oligonucleotídeos , Transdução de Sinais , Receptor Toll-Like 9/imunologia , Receptor Toll-Like 9/metabolismo , Transfecção , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo
19.
Viral Immunol ; 23(1): 17-28, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20121399

RESUMO

Studies from our laboratory and those of others have implicated lipopolysaccharide (LPS)-induced MAPK signaling as an important pathway in the regulation of cytokine expression. In this article, the regulation of IL-12 expression in two different human myeloid cell populations was evaluated. In primary monocytes, the inhibition of p38 enhanced IL-12 production, whereas it downregulated IL-12 production in THP-1 cells. The role of MAPK signaling in transcription factor binding to the IL-12p40 promoter was subsequently determined. In primary monocytes, ERK and p38 inhibition increased binding of AP-1 and Sp1, respectively, to the IL-12p40 promoter, while JNK inhibition increased NF-kappaB, AP-1, and Sp1 binding. In THP-1 cells, p38, ERK, and JNK inhibition increased NF-kappaB and Sp1 binding to the IL-12p40 promoter, while inhibiting AP-1 binding. In monocytes, mutations in the NF-kappaB, AP-1, Sp1, or Ets-2 binding sites resulted in complete inhibition of LPS-stimulated IL-12p40 promoter activity using a luciferase-based assay. In contrast, promoter activity was abrogated in THP-1 cells only when the Sp1 or Ets-2 binding sites were mutated. Transcription factor binding to the IL-12p40 promoter following in-vitro HIV infection demonstrated several differences between monocytes and THP-1 cells. Infection with HIV produced an increase in NF-kappaB, AP-1, and Sp1 binding in primary monocytes. In contrast, binding of Ets-2 was dramatically impaired following HIV infection of monocytes, but was unaffected in THP-1 cells. These data clearly show that although LPS induces IL-12p40 expression in primary monocytes and THP-1 cells, the signaling pathways involved and the effect of HIV infection differ and can have disparate effects in these two cell types.


Assuntos
Infecções por HIV/imunologia , Subunidade p40 da Interleucina-12/biossíntese , Lipopolissacarídeos/imunologia , Sistema de Sinalização das MAP Quinases , Células Mieloides/imunologia , Transdução de Sinais , Linhagem Celular , Células Cultivadas , DNA/metabolismo , Humanos , NF-kappa B/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteína Proto-Oncogênica c-ets-2/metabolismo , Fator de Transcrição Sp1/metabolismo , Fator de Transcrição AP-1/metabolismo
20.
Curr Genomics ; 10(5): 306-17, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20119528

RESUMO

Macrophages are cells of the immune system that protect organisms against invading pathogens by fulfilling critical roles in innate and adaptive immunity and inflammation. They originate from circulating monocytes and show a high degree of heterogeneity, which reflects the specialization of function given by different anatomical locations. Differentiation of monocytes towards a macrophage phenotype is also accompanied by an increase of resistance against various apoptotic stimuli, a required characteristic that allows macrophages to accomplish their function in a stressful environment.Apoptosis, a form of programmed cell death, is a tightly regulated process, needed to maintain homeostasis by balancing proliferation with cellular demise. Caspases, a family of cysteine proteases that are highly conserved in multicellular organisms, function as central regulators of apoptosis. FLIP (FLICE-inhibitory protein), anti-apoptotic members of the Bcl2 family and inhibitors of apoptosis (IAP) are the main three groups of anti-apoptotic genes that counteract caspase activation through both the extrinsic and intrinsic apoptotic pathways.Modulation of the apoptotic machinery during viral and bacterial infections, as well as in various malignancies, is a wellestablished mechanism that promotes the survival of affected cells. The involvement of anti-apoptotic genes in the survival of monocytes/macrophages, either physiological or pathological, will be described in this review. How viral and bacterial infections that target cells of the monocytic lineage affect the expression of anti-apoptotic genes is important in understanding the pathological mechanisms that lead to manifested disease. The latest therapeutic approaches that target anti-apoptotic genes will also be discussed.

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