As purinas extracelulares ATP e adenosina têm sido extensivamente estudadas em diferentes modelos e tipos celulares na modulação de várias respostas fisiológicas e patológicas. No entanto, a inosina extracelular, produto da degradação da adenosina pela Adenosina Deaminase (ADA), foi considerada por muito tempo um simples metabólito inativo. Recentemente, diversos trabalho têm demonstrado que este nucleosídeo possui importante papel na regulação de inúmeros processos. As células de Sertóli são as células somáticas dos túbulos seminíferos, e possuem fundamental importância na espermatogênese. Estas células, expressam diferentes purinoreceptores, estando estes envolvidos na regulação de diversas funções destas células relacionadas ao controle do desenvolvimento das células germinativas. No testículo, o TNF-α é produzido pelas espermátides redondas e pelos macrófagos ativados presentes no espaço intersticial. As células de Sertóli expressam os dois receptores descritos para TNF-α, TNF-RI (p55) e TNF-RII (p75), e diversos trabalhos tem descrito a modulação de diferentes funções destas células por esta citocina, incluindo a modulação da produção de NO e da fosforilação das MAPKs. Recentemente, foi descrita a modulação purinérgica da sinalização por TNF-α, bem como, a atividade ATPásica do receptor TNF-R1. Assim, nesta dissertação, foi estudado o efeito do TNF-α nos níveis das purinas extracelulares, além da possível participação purinérgica na sinalização desta citocina, em células de Sertóli em cultura. O tratamento destas células com TNF-α leva a um rápido aumento (5minutos) da concentração extracelular da inosina, que se prolonga até seis horas de incubação, sem alterar a concentração dos demais nucleotídeos e seus metabólitos. A inosina modula a produção de NO e a fosforilação das MAPKs ERK½ e p38 em células de Sertóli em cultura, aparentemente, através de diferentes mecanismos, sendo o primeiro efeito independente do receptor para adenosina A1 e o segundo efeito dependente da ativação deste receptor. Além disso, a inosina extracelular está envolvida na modulação da produção de NO e da fosforilação da MAPK ERK½ em células de Sertóli em cultura pelo TNF-α. A inibição do acúmulo de inosina estimulado pelo TNF-α através da incubação com um inibidor da adenosina deaminase cancela o aumento da produção de NO estimulada por esta citocina. Além disso, o bloqueio do receptor para adenosina A1 por antagonistas específicos impede o aumento na fosforilação da ERK½ estimulada por esta citocina. Assim, nesta dissertação, é descrito um papel intermediário da inosina extracelular na sinalização do TNF-α em células de Sertóli em cultura.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-21T11:43:47Z No. of bitstreams: 1 alexandresilvachaves.pdf: 1552343 bytes, checksum: e93b7672976058e0adc057d62686adba (MD5) / Rejected by Adriana Oliveira (adriana.oliveira@ufjf.edu.br), reason: on 2017-06-21T12:22:29Z (GMT) / Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-06-21T12:24:25Z No. of bitstreams: 1 alexandresilvachaves.pdf: 1552343 bytes, checksum: e93b7672976058e0adc057d62686adba (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-08-07T19:04:35Z (GMT) No. of bitstreams: 1 alexandresilvachaves.pdf: 1552343 bytes, checksum: e93b7672976058e0adc057d62686adba (MD5) / Made available in DSpace on 2017-08-07T19:04:35Z (GMT). No. of bitstreams: 1 alexandresilvachaves.pdf: 1552343 bytes, checksum: e93b7672976058e0adc057d62686adba (MD5) Previous issue date: 2014-08-29 / A tuberculose é uma doença infecciosa cujo principal agente etiológico é o Mycobacterium tuberculosis (Mtb). Macrófagos constituem a primeira linha de defesa contra a tuberculose, bem como o habitat preferencial para o Mtb. Antígenos específicos do Mtb tais como ESAT-6, CFP-10 e Rv1733 podem modular a produção de citocinas, influenciando o curso da infecção. Macrófagos infectados liberam uma grande quantidade de citocinas incluindo fator de necrose tumoral-alfa (TNF-a). As ações do TNF-a são iniciadas por seus dois receptores de membrana, mTNF-R1 e mTNF-R2, os quais podem sofrer clivagem proteolítica, resultando nas formas solúveis sTNF-R1 e sTNF-R2, respectivamente. No presente estudo, macrófagos RAW264.7 (2x105/mL) foram estimulados com a proteína de fusão ESAT6:CFP10 ou com o antígeno recombinante DosR, Rv1733, na concentração de 5pg/mL por 24 e 48 horas e a produção de TNF-a, bem como a expressão dos mTNF-Rs e concentração dos sTNF-Rs foram investigadas. Os sobrenadantes de cultura foram coletados e os níveis de TNF-a, IL-10, sTNF-R1 e sTNF-R2 foram avaliados por ELISA, enquanto que os níveis de óxido nítrico (NO) foram analisados pela reação de Griess. A determinação da viabilidade celular foi realizada pelo ensaio de MTT. Níveis de mTNF-R1 e mTNF-R2 foram analisados por citometria de fluxo e a expressão de iNOS e Arg-1 determinada por imunocitoquímica. Os resultados mostraram que ambos os antígenos induziram um aumento na expressão de TNF-a (p<0,05) sem afetar os níveis de NO, IL-10, iNOS e Arg-1. A expressão elevada de mTNF-R1 (p<0,05) em células RAW264.7 foi observada para ambos os antígenos após 24 horas de cultura, mas apenas o Rv1733 foi capaz de diminuir os níveis de sTNF-R1 (p<0,05) nos sobrenadantes de cultura. A expressão de mTNF-R2 e a detecção de sTNF-R2 (p<0,05) foi maior após estimulação com Rv1733, em 24 e 48 horas de cultura. Esses resultados sugerem que a proteína de fusão ESAT6:CFP10 e o antígeno DosR, Rv1733, modulam diferentemente a produção de TNF-a e a expressão de seus receptores em macrófagos, o que influenciar na suscetibilidade à infecção. / Tuberculosis is a severe infectious disease caused by Mycobacterium tuberculosis (Mtb). Macrophages provide a first line of defense against tuberculosis and major habitat for Mtb. Specific Mtb antigens, such as ESAT-6, CFP-10 and Rv1733, may modulate the production of cytokines, influencing the course of infection. Infected macrophages release a range of cytokines including tumor necrosis factor-alpha (TNF-a). TNF-a actions are triggered by its two membrane receptors, mTNF-R1 and mTNF-R2, which may undergo a shedding process, resulting in the soluble form sTNF-R1 and sTNF-R2, respectively. In the present study, RAW264.7 macrophages (2 x 105/mL) were stimulated with the fusion protein ESAT6:CFP10 or the recombinant DosR antigen Rv1733 at 5[1,g/mL for 24 and 48 hours and the production of TNF-a and expression membrane and soluble TNFRs were investigated. Culture supernatants were collected and levels of TNF-a, IL-10, sTNF-R1 and sTNF-R2 evaluated by ELISA, while levels of nitric oxide (NO) were assessed by the Griess reaction. To determine cell viability the MTT assay was used. Levels of mTNF-R1 and mTNF-R2 were analysed by flow cytometry and the expression of iNOS and Arg-1 were determined by immunocytochemistry. The results show that both antigens induced an increase in TNF-a production (p<0.05) without affecting levels of NO, IL-10, iNOS and Arg-1. Elevated expression of mTNFR1 (p<0,05) in RAW264.7 cells was observed for both antigens after 24h of culture, but only Rv1733 decreased sTNF-R1(p<0,05) in culture supernatants. Expression of mTNF-R2 and detection of sTNF-R2 (p <0.05) was enhanced by Rv1733 after 24h and 48h of culture. These results suggest that the fusion protein ESAT6:CFP10 and the DosR antigen Rv1733 differentially modulate the production of TNF-a and the expression of its receptors on macrophages, which may affect the susceptibility to infection.

AimThe broad aim of this thesis was to explore the risk of malignancy in people with rheumatoid arthritis (RA), treated with anti-tumour necrosis factor (TNF) drugs.MethodsThis thesis used data from patients with RA registered with the British Society of Rheumatology Biologics Register-RA. The risk of cancer in biologic-naive patients treated with traditional disease modifying drugs (nbDMARD) was compared to that in the general population by calculating standardised incidence ratios (SIR). The influence of anti-TNF on cancer risk was then explored by comparing the risk in the anti-TNF cohort to that in the nbDMARD cohort using Cox proportional hazard models.ResultsThe risk of cancer was increased in the nbDMARD cohort by 28% compared to the general population (SIR 1.28, 95% confidence interval (CI) 1.10, 1.48). Risks of lung cancer (SIR 2.39, 95% CI 1.75, 3.19), Hodgkin lymphoma (SIR 12.82, 95% CI 4.16, 29.92) and Non-Hodgkin Lymphoma (SIR 3.12, 95% CI 1.79, 5.07) were increased compared to the general population and both prostate cancer and cancers of the female genital organs reduced; SIRs 0.35 (95% CI 0.11, 0.82) and 0.35 (95% CI 0.10, 0.90) respectively. There was no difference in the risk of cancer in patients treated with anti-TNF compared to nbDMARD, after adjusting for differences in baseline characteristics; Hazard ratio for lymphoma: 1.00 (95% CI 0.49, 2.05); cancers of the solid organs: 0.83 (95% CI 0.64, 1.07); and keratinocyte skin cancer: basal cell carcinoma 1.06 (95% CI 0.64, 1.75), squamous cell carcinoma 1.62 (95% CI 0.44, 5.90). ConclusionsSubjects with RA, treated with nbDMARD were at increased risk of cancer compared to the general population. In particular, lung cancer, lymphoma and KSC were increased. Treatment with the TNF inhibitors ETA, INF or ADA was not associated with a difference in relative risk of lymphoma, solid cancer or skin cancers when compared to nbDMARD.

Periodontitis potentially contributes to many systemic diseases. Specific gram-negative bacteria such as Porphyromonas gingivalis (P.g) and Treponema denticola (T.d) contribute to the initiation and progression of periodontal disease via factors such as NF-κB, TNF-α, IL-1β, and CXCL1. Down-regulation of these factors by natural compounds or short hairpin RNAs (shRNAs) reduces periodontal bacteria-induced inflammation. Our preliminary data indicated that P.gingivalis / lipopolysaccharide (LPS) stimulates chemokine CXCL1 production in macrophages. CXCL1 stimulates LPS-induced TNF-α expression, resulting in inflammation. We hypothesize that inhibiting the expression of CXCL1 will reduce LPS-induced TNF-α production. We recently demonstrated that a CXCL1 shRNA inhibits LPS-stimulated CXCL1 production in macrophages and leads to reduced expression of LPS-stimulated pro-inflammatory cytokines TNF-α and IL-1β. This indicates that CXCL1 shRNAs have potential as inhibitors of LPS-induced inflammation. Further studies are needed to confirm these as well as to identify the signaling pathway.

The infections agent of Lyme disease, Borrelia Burgdorferi is a complex microorganism with a highly diverse genome. One of the most remarkable aspects of the B. burgdorferi genome is the large number of sequences encoding predicted or known lipoproteins, including outer-surface proteins. The B. burgdorferi genome encodes no recognizable toxins. Instead, this extracellular pathogen causes pathology by migration through tissues, adhesion to host cells, and evasion of immune clearance. Inflammation elicited by infection with B. burgdorferi depends on the ability of the spirochete to survive in the mammalian host, as well as the immune response that arises upon the interaction of the bacterium with phagocytic, T and other cell types. Innate immune responses are critical in recognition and clearance of pathogens, and also play an important role in the outcome of adaptive immune responses. The regulation of innate immune responses to pathogens occurs through the interaction of Toll-like receptors (TLRs) with pathogen-associated molecular patterns (PAMPs) and the activation of several signaling pathways whose contribution to the overall innate immune response to pathogens is poorly understood. In this study we demonstrate a mechanism of control of murine macrophage responses mediated by TLR1/2 heterodimers through c-Jun N-terminal kinase 1 (JNK1) activity. JNK also controls tumor necrosis factor production and TLR-mediated macrophage responses to B. burgdorferi. We also show that the proximal promoter region of the human tlr1 gene contains an AP-1 binding site that is subjected to regulation by the kinase and binds two complexes that involve the JNK substrates c-Jun, JunD, and ATF-2. These results demonstrate that JNK1 regulates the response to TLR1/2 ligands and suggest a positive feedback loop that may serve to increase the innate immune response to the spirochete. MCJ is a newly identified member of the DnaJ protein family of cochaperones that contains unique features different than the normally described DnaJ proteins. However, there is little known about its function and the role it plays in different cells and systems. It has been previously shown that MCJ is required for the repression of the ABCB1 drug transporter expression in breast cancer cells, and that this repression is mediated through the control of c-Jun protein stability. We were therefore interested in determining the role that MCJ plays in macrophages in response to B. burgdorferi antigens. We now provide evidence that MCJ controls inflammatory responses of macrophages through the regulation of c-Jun protein stability, and the expression and release of the inflammatory cytokine TNF through the regulation of the expression of TNF converting enzyme (TACE) inhibitor tissue inhibitor of metalloproteinase 3 (TIMP-3).

The use of highly active antiretroviral therapy (HAART) has significantly decreased the mortality rate of HIV-1 patients, however the increased survival has led to the development of complications associated with the persistence of the viral infection. Nearly half of HIV-1-infected individuals develop HIV-associated neurocognitive disorders (HAND) as the effects of the chronic infection leads to neuronal injury and synaptic loss in the central nervous system (CNS). The neurotoxicity of HIV-1 has largely been attributed to the inflammation caused by viral replication and the altered signaling of astrocytes, microglia, and macrophages. Although HAART has improved the control of viral replication, the effects from inflammation remain a concern, particularly those of the pro-inflammatory cytokine, tumor necrosis factor alpha (TNF-α). TNF-α has been a therapeutic target for other diseases associated with chronic inflammation, such as rheumatoid arthritis, but emerging evidence has suggested that TNF-α signaling can have a dual role, especially in the CNS, proving the complexity in the modulation of the TNF-α pathway. Although the detrimental effects of TNF-α have been well-characterized, we lack a complete understanding of the beneficial role of TNF-α. TNF-α signaling has largely been considered to be neurotoxic but has been able to regulate neurite outgrowth in the context of neural development. Since TNF-α is upregulated in various neurodegenerative conditions, we considered potential outcomes of TNF-α on neurite outgrowth following injury. Initially, most would assume that TNF-α would prevent neurite outgrowth as apoptosis is a common outcome of TNF-α-induced signaling. If TNF-α signaling strictly prevents neurite outgrowth, anti-TNFα therapies could be considered to reverse this effect. However, upon induced injury, we observed an increase in neurite regrowth following induced injury in human primary fetal neurons, demonstrating a strong need for a deeper understanding of this dual role of TNF-α. Anti-TNF-α therapies have been considered for HIV-1-infected patients to reduce the chronic inflammation, however inhibiting TNF-α signaling could have side-effects that could prevent neuronal recovery from HIV-1 effects. Targeting pathways downstream of TNF-α signaling would be more advantageous to mediate the beneficial role of TNF-α in the CNS. We investigated the transcriptional effects of TNF-α treatment on neurons to uncover a potential pathway to promote neurite outgrowth. One pathway we have discovered to be beneficial in primary human fetal neurons is TNF-α-induced Ephrin B2 upregulation. Ephrin B2 (EphB2) receptors are important mediators of neuronal development and synaptic plasticity, however little has been established in regards to their role in HIV and inflammation, particularly in the CNS. EphB2 can mediate axonal development by providing retractive cues to assist the axon to reach the target, but EphB2 can also promote dendritic branching to improve learning and memory, which would be particularly beneficial for HAND patients that experience cognitive deficits. We observed a correlation between the upregulation of EphB2 in response to TNF-α and neurite outgrowth, which provides a potential pathway to repair damaged neurons and re-establish lost neuronal connections. Dendritic pruning and neuronal loss has been observed in HAND patients, so this ability to promote repair could prevent, improve, or recover the cognitive deficits experienced by HIV-patients with HAND. TNF-α, although primarily known to induce neurotoxicity, strongly activates the nuclear factor-kappaB (NF-κB) pathway, which can have a very wide range of transcriptional effects. Therefore, our hypothesis is that the TNF-α-induced neurite regrowth occurs through an upregulation EphB2 in an NF-κB-dependent pathway. TNF-α has been well established to induce NF-κB signaling, mostly by promoting the translocation of the NF-κB p65 DNA binding factor to the nucleus for transcriptional regulatory effects. NF-κB can regulate neuronal growth and process development of both dendrites and axons, which would correlate to the neurite regrowth observed following TNF-α upon induced injury. The regulation of EphB2 by NF-κB has not been extensively studied, but EphB2 can be negatively regulated by an NF-κB family member, c-Rel. We analyzed the EphB2 promoter and identified three NF-κB p65 binding sites upstream from the transcriptional start site, which provided insight to our hypothesis. We established that p65 directly binds to and can regulate EphB2 promoter activity in response to TNF-α. Since the dual role of TNF-α can be dependent on the receptor through which the signaling proceeds, either TNF-α receptor 1 (TNFR1) or TNF-α receptor 1 (TNFR2), we investigated if this upregulation of EphB2 is receptor dependent and determined EphB2 is induced primarily through activation of TNFR2. Neurons express both receptors, however, the effects of TNF-α to promote neuroprotection and repair primarily occur through the TNF-α/TNFR2 regulatory axis. Although we have been established the mechanism of TNF-α-induced EphB2 and there is a strong correlation with neurite outgrowth following induced injury, we considered the possibilities to modulate EphB2 in the absence of TNF-α to demonstrate the direct effects of EphB2 expression. Several approaches could be used to mediate EphB2 activation or inhibition in vitro. RNA interfering techniques, such as small interfering RNA (siRNA), are useful, but we were interested in a complete knockout strategy. Since our approach was to assess the effects of EphB2 knockout only on neurite outgrowth following induced injury, a knockout animal model would not be appropriate, as a lack of EphB2 would affect the development of the neurons, unless an inducible knockout model was established. This is a lengthy and elaborate process and, more importantly, would only be available in a non-human model. Other techniques, such as transcription activator like effector nucleases (TALENs), can generate knockout systems that are targeted to specific regions of a gene, but specific binding proteins must be created to recruit the endonucleases to the target. Clustered regularly-interspaced short palindromic repeats/CRISPR associated protein 9 (CRISPR/Cas9) has emerged as a specific and relatively easy technique to knockout genes of interest and uses short RNA sequences to guide Cas9 endonucleases to target regions to create double stranded breaks in the DNA to silence the gene. Once concern with Cas9 is specificity to target only the desired region of the gene, as off-target effects can occur and may result in unwanted gene silencing. A Cas9 mutant, Cas9 nickase (Cas9n), has been created to have more specificity by requiring two guide RNAs to recruit two Cas9 nickases to generate a double stranded break as they function as nickases to only create a nick in one DNA strand. We developed this strategy to remove exon 1 of the EphB2 gene by using two pairs of Cas9 nickases, with four guide RNAs, to eliminate any chance for off-target effects but retaining the desired outcome of and EphB2 knockout. We validated the system by demonstrating that a knockout of EphB2 increases adhesion and prevents migration in human embryonic kidney 293T (HEK293T) cells. Although this cell model is not a neuronal cell model, the migration assay demonstrates the functional loss of EphB2. We also created an inducible Ephb2 system to overexpress EphB2. Together these provide essential tools to verify the direct involvement of EphB2 in neurite outgrowth. Taken together, our studies characterize a novel mechanism for neurite outgrowth following injury in neurons: TNF-α/TNFR2-induced EphB2 signaling in an NF-κB p65-dependent manner. In addition to the established mechanism, we developed a technique to assess the effects of EphB2 knockout and overexpression in the context of neurite outgrowth: EphB2-targeted-Cas9n and EphB2 inducible construct. This mechanism yields insight into a potential downstream pathway to be utilized to repair damaged regions in the brain and reverse cognitive deficits in neurodegenerative conditions, especially in a chronic inflammatory environment, such as HIV-1 infection. The strategies created provide a valuable toolset to demonstrate the direct effects of modulating EphB2 signaling, not only in neurons for effects on neuronal health and synaptic plasticity, but also in other disease models, such as glioblastoma, in which EphB2 was demonstrated to promote invasion and migration of tumor cells. These observations and the usefulness of the modulatory strategies likely extend to multiple neurodegenerative diseases that demonstrate cognitive deficits that correlate to neuroinflammation. / Biomedical Neuroscience

INTRODUCTION: Porphyromonas gingivalis (P.g), a gram-negative anaerobe, is the major bacterium in the red complex (Socransky et al. 1998) and responsible for the onset and progression of severe periodontal disease. P. gingivalis is currently considered the ‘keystone’ pathogen of periodontal disease. It can produce several virulence factors, such as cysteine proteinases (gingipains), lipopolysaccharide (LPS), capsule and fimbriae. The LPS plays an important role in periodontal disease by inducing inflammation via stimulation of some cytokines such as TNF-ɑ. TNF-ɑ can activate expression of early response genes in macrophages, including Tumor Necrosis Factor-?-Induced Protein 1 (TNFAIP1). However, the role of TNFAIP1 in LPS-induced inflammation is largely unknown. OBJECTIVE: 1. Identification of TNFAIP1 biological functions in response to LPS/TNF-ɑ; 2. Identification of the TNFAIP1 mediated signaling pathway; 3. Determination of factors involved in the TNFAIP-dependent signaling pathway; 4. Analysis of TNFAIP1 promoter activity. MATERIALS AND METHODS: Mouse RAW cells, human THP-1 cells or MC3T3 cells were cultured in RPMI or ɑ-MEM media with 10% FBS at 37°C in 5% CO2. For DNA construction of TNFAIP1 cDNA or its promoter, DNAs were generated by polymerase chain reaction (PCR) with specific primers and templates. The cloned DNA sequences were confirmed by sequencing. Experiments to identify the biological function of TNFAIP1 and its promoter activity, utilized ELISA, DNA recovery, western blot, protein array, and promoter assay. RESULTS: 1. LPS-induced the activation of p-MARK or p-PI3K (but not p-JAK), the production of TNF-ɑ, NFĸB or TNFAIP1 was confirmed by ELISA and western blot analysis; 2. Transfection of TNFAIP1 cDNA for 1-10 hours stimulated TNF-ɑ production in macrophage cells but not after longer exposure; 3. Caspase 1 and 3 were induced by TNFAIP1 after transfection of TNFAIP1 for 20 hours; 4. Overexpression of TNFAIP1 induced apoptotic proteins, such as Bcl-x, Caspase 3, Catalase, Claspin, Cytochromic, HO-1/HMOX1/HSP32, MCL-1, P27/Kip1, or SMAC/Diablo; 5. TNFAIP1 promoter DNA was cloned into pGL3 basic plasmid DNA to determine promoter activity. TNFAIP1 promoter activity was tested via its potential protein-protein interaction using luciferase gene expression. With a MAPK inhibitor, TNFAIP1 promoter activity was increased. In contrast, with an ATK inhibitor, TNFAIP1 promoter activity was reduced. CONCLUSIONS: 1. TNFAIP1 is an important factor of the LPS/TNF-ɑ-dependent pathway; 2. MAPK or PI3K functions as an upstream factor of TNFAIP1, and LITAF is downstream factor of TNFAIP1-mediated signaling pathway in response to LPS; 3. Transfection of TNFAIP1 cDNA stimulated TNF-ɑ production for 1-10 hours exposure but reduced it for 10 - 20 hours exposure; 4. Overexpression of TNFAIP1 can increase expression of apoptotic proteins, Bcl-x, Caspase 3, Catalase, Claspin, Cytochromic, HO-1/HMOX1/HSP32, MCL-1, P27/Kip1, or SMAC/Diablo; 5. AKT and MAPK may act as transcriptional regulators of TNFAIP1 gene by binding to the promoter region. AKT upregulates TNFAIP1 gene expression and MAPK downregulates TNFAIP1 gene expression.

A sinalização purinérgica tem sido demonstrada como um um importante modulador dediversos processos fisiológicos e fisiopatológicos. Dentre os receptores purinérgicos, o receptor P2X7 distingui-se por requerir altas concentrações de ATP em sua ativação. As demonstrações prévias de que a glândula pineal responde a diferentes estímulos purinérgicose a altas concentrações de ATP sugere um papel para os receptores P2X7 nesta glândula, embora sua expressão e função não estivesse estabelecida. O objetivo deste trabalho, portanto, foi caracterizar funcionalmente o receptor P2X7 na glândula pineal de ratos. Os resultados obtidos demonstram, pela primeira vez, a expressão gênica e proteica do receptor P2X7 na glândula pineal. Os efeitos da ativação destes receptores levam a uma inibição nos níveis de melatonina induzida por isoprenalina por um mecanismo independente da via do fator de transcrição NF-kB e da fosfolipase C. Além disso, a estimulação destes receptores inibiu a síntese de TNF induzida por LPS, resultado este semelhante ao observado na presença do pré-tratamento com antagonistas do receptor P2X7. Estes dados confirmam a presença de receptores P2X7 na glândula pineal e reiteram o relevante papel da estimulação purinérgica a sobre a síntese de melatonina e sobre a capacidade da pineal em responder a PAMPs, como o LPS / Purinergic signalling has been demonstrated as an important modulator ofseveral physiological and pathophysiological processes. Among the purinergic receptors, the activation of P2X7 receptor requireshigh concentrations of ATP. The previous demonstration that the pineal gland is responsive to different purinergic stimulus and to high concentrations of ATPsuggests a role for P2X7, although its expression and function remained unclear. The aim of this study was to functionally characterize the P2X7 receptor in the rat pineal gland.The data showedthe P2X7 receptor mRNA and protein expression in the pineal gland. The effect of its activation leads toan inhibition of melatonin content induced by isoprenaline through an independent NF-kB and PLC pathways. Furthermore, the P2X7 receptor activation inhibits the LPS-induced TNF synthesis, a similar result observed in the presence of the pre-treatment with P2X7 receptors antagonists. These data demonstrate the presence of P2X7 receptors in the rat pineal gland and confirm the relevant role of the purinergic stimulation to the pineal melatonin synthesis and responsiveness to PAMPs such as LPS

Herpes Zoster é uma doença causada pela reativação do vírus Varicela Zoster nos gânglios sensoriais, caracterizada pelo desenvolvimento de lesões na pele e dor. Não há modelos animais disponíveis para estudo da patofisiologia da doença. No entanto, um modelo murino que utiliza o HSV-1 tem sido usado para tal fim, visto que os animais desenvolvem lesões zosteriformes e desenvolvem hipersensibilidade na pata infectada. Não há dados na literatura acerca da resposta imune que se desenvolve nos gânglios da raiz dorsal destes animais. Logo, o objetivo deste trabalho foi o de avaliar células e mediadores inflamatórios presentes nos gânglios da raiz dorsal e sua relação com a hiperalgesia durante a infecção cutânea por HSV-1. Durante a fase aguda da infecção, os camundongos desenvolveram hiperalgesia nas patas ipsilaterais a partir do 3 dia pós-infecção, que perdurou até o 7 dia pós-infecção. A maior carga viral foi detectada nos gânglios L4, L5 e L6, os quais compõem o nervo ciático, que inerva a área infectada. O tratamento dos animais infectados com dexametasona ou fucoidina resultou na redução do comportamento de hiperalgesia, a partir do 5 dia pós-infecção, que corresponde ao período em que a migração de leucócitos passa a aumentar nos gânglios da raiz dorsal. Macrófagos, neutrófilos e linfócitos T CD4 foram detectados nos gânglios durante a infecção aguda. No entanto, linfócitos T CD8 estavam ausentes. A expressão do mRNA de TNF- e COX-2 estava aumentada nos gânglios, e o tratamento de animais infectados com drogas inibidoras de ambos resultou na redução da hiperalgesia. Os receptores do tipo Toll-like e da IL-1 não participam da geração da hipersensibilidade herpética. Após 50 dias da infecção, constatou-se que alguns animais apresentavam comportamento de hiperalgesia irreversível, semelhante à neuralgia pós-herpética humana (NPH). Não houve diferença significativa na incidência da NPH em animais de linhagens ou sexos diferentes. Ainda, o tratamento com drogas anticonvulsivantes e antidepressivas, mas não com morfina e anti-inflamatórios, resultou na redução transiente da hiperalgesia. Neste período, não há participação da inflamação na manutenção da hiperalgesia. A expressão de TNF- e COX-2 retorna aos níveis basais, e não são mais detectados neutrófilos e macrófagos. No entanto, a migração de linfócitos T CD4+ e CD8+ aos gânglios aumenta de maneira tempo-dependente. Durante a NPH, detectou-se uma intensa ativação das células satélites gliais, que contribuem para a manutenção da hiperalgesia pós-herpética. Nossos resultados demonstram que a manutenção hiperalgesia herpética é resultado da intensa resposta inflamatória que ocorre nos gânglios da raiz dorsal infectados, com aumento da produção de TNF- e COX-2, importantes mediadores para a hipersensibilidade. No entanto, durante a neuralgia pós-herpética, não há participação de células ou mediadores inflamatórios, mas de células da glia, as quais são importantes na manutenção da hiperalgesia. / Herpes Zoster is a disease caused by reactivation of varicella zoster virus in sensory ganglia, characterized by dermal rash and pain. There are no animal models available to study the pathophysiology of the disease. A murine model of HSV-1 infection on the hind paw skin has been used to study HZ, since mice develop HZ-like skin lesions and pain-related responses. There are no data available about the immune response in dorsal root ganglion (DRG) of these mice. Thus, the aim of this study was to evaluate cells and inflammatory mediators present in DRGs and its relationship with hiperalgesia during HSV-1 cutaneous infection. During the acute phase of infection, mice developed hyperalgesia in ipsilateral paws from 3 days post-infection, which persisted until 7 days post-infection. The highest viral load was detected in ganglia L4, L5 and L6. Treatment of infected mice with fucoidin or dexamethasone resulted in the reduction of hyperalgesic behavior, from the 5th post-infection day, which corresponds to the period in which leukocyte migration increase in the dorsal root ganglia. Macrophages, neutrophils and CD4 + T lymphocytes were detected in the ganglia during acute infection. However, CD8 + T lymphocytes were absent. The mRNA expression of TNF- and COX-2 was increased in dorsal root ganglia, and the treatment of infected mice with drugs that inhibits both mediators resulted in reduced hyperalgesia. The Toll-like receptors and IL-1 does not participate in the generation of herpetic hypersensitivity. After 50 days of infection, it was found that some animals presented irreversible hyperalgesic behavior, like human post-herpetic neuralgia (PHN). There was no significant difference in the incidence of PHN in animals of different genders or strains. Furthermore, treatment with anticonvulsant and antidepressant drugs, but not morphine and anti-inflammatory, resulted in transient reduction of hyperalgesia. In this period, there is no participation of inflammation in the hyperalgesia maintenance of. The expression of TNF- and COX-2 returns to baseline levels, and neutrophils and macrophages are no longer detected. However, the migration of CD4 + and CD8 + to ganglia increases in a time-dependent manner. During NPH, an intense activation of glial cells satellites was detected, that contributes to the maintenance of post-herpetic hyperalgesia. Our results demonstrate that herpetic hyperalgesia maintenance is a result of an intense inflammatory response that occurs in the infected dorsal root ganglia, with increased production of TNF- and COX-2. However, during post-herpetic neuralgia, there is involvement of glial cells, which are important in hyperalgesia maintenance.

Esquistossomose é uma das doenças parasitárias com maior incidência mundial. Schistosoma mansoni, a única espécie encontrada no Brasil, tem um ciclo de vida complexo que inclui seis estágios de desenvolvimento distintos e dois hospedeiros, sendo um deles o homem. Nosso grupo identificou um gene que codifica um receptor que possui homologia com o receptor de TNF-&#945; humano em S. mansoni (SmTNFR) e descrevemos o efeito in vitro da citocina humana TNF-&#945; sobre a expressão gênica em larga escala no parasita. A via de sinalização através da qual o TNF-&#945; atua sobre o parasita permanece desconhecida. Em humanos, o TNF-&#945;, ao se ligar à isoforma do receptor que é mais semelhante ao SmTNFR, inicia uma cascata de fosforilação que conduz à ativação de diversas proteínas quinases que levam à ativação de fatores de transcrição. A nossa hipótese é a de que esta citocina humana atuaria no parasita de forma semelhante, resultando na alteração da expressão gênica do parasita observada em nosso trabalho anterior. No presente trabalho tivemos como objetivo verificar se há aumento de proteínas fosforiladas após o tratamento in vitro de vermes com o TNF-&#945; humano, e identificá-las, elucidando a via de sinalização induzida por esta citocina em S. mansoni. A fim de identificar as proteínas que são significativamente diferencialmente fosforiladas após exposição de S. mansoni à citocina humana, vermes machos adultos foram incubados em cultura por 15 min com TNF-&#945; (20 ng / ml), ou somente com o veículo, em controles, seguido da extração de proteínas totais. Utilizamos a abordagem fosfoproteômica por meio da realização de eletroforese bidimensional, seguida de coloração com corante específico para fosfoproteínas Pro-Q Diamond (Invitrogen). Para identificar quais proteínas tiveram fosforilação alterada pelo tratamento, fizemos uma análise quantitativa dos spots (volume dos spots) nas imagens dos géis corados com Pro-Q, utilizando o software 2D Platinum (GE). Em seguida a coloração de proteína total dos géis foi realizada utilizando Coomassie Blue Coloidal, para localização de todos os spots de proteínas de cada gel. Cortamos dos géis os spots de proteínas que apresentaram mudanças estatisticamente significativas na fosforilação (n = 3 réplicas; p <0,05, teste-t), com base na comparação de seus volumes relativos nas imagens dos géis das amostras tratadas comparadas com as controles, e em seguida as proteínas das amostras foram identificadas por espectrometria de massa. Analisamos três réplicas biológicas e observamos 45 spots que tiveram fosforilação significativamente alterada, sendo que 42 deles apresentaram fosforilação aumentada e 3 apresentaram fosforilação diminuída após o tratamento com a citocina. Entre os spots identificados por espectrometria de massa, verificou-se que proteínas relacionadas a processos metabólicos, sinalização celular, citoesqueleto e contração muscular estavam entre as que sofreram aumentos de fosforilação com o tratamento com TNF-&#945; humano. Embora a abordagem experimental adotada para este estudo não tenha sido sensível o suficiente para concluir qual via canônica de transdução de sinal é ativada por TNF-&#945; humano em S. mansoni, este estudo confirmou o aumento da fosforilação de proteínas-alvo induzido por TNF-&#945; humano, abrindo novos caminhos para uma investigação mais aprofundada que caracterize o papel das proteínas identificadas como alteradas por essa via de sinalização, e permita entender melhor a importância do TNF-&#945; humano na biologia do S. mansoni e na interação parasita-hospedeiro. / Schistosomiasis remains one of the parasitic diseases with the highest incidence worldwide. Schistosoma mansoni, the only species found in Brazil, has a complex life cycle which includes six life stages and two hosts, one of them being humans. Our group has identified a gene that encodes a TNF-alpha receptor-like in S. mansoni (SmTNFR) and described the in vitro effect of human TNF-alpha cytokine on large-scale gene expression of the parasite. The signaling pathways by which TNF-alpha acts upon the parasite remain unknown. In humans, when TNF-alpha binds to the receptor isoform that is most similar to SmTNFR it initiates a phosphorylation cascade that activates a signaling pathway leading to the activation of transcription factors. Our hypothesis is that this cytokine could act in the parasite through a phosphorylation cascade that activates transcription factors resulting in the change of gene expression observed in our previous work. The aim of this work was to verify if there were proteins that showed increased phosphorylation upon the in vitro treatment of worms with human TNF-alpha, identifying them, to try and elucidate the signaling pathway by which the cytokine acts in S. mansoni. In order to identify which proteins are significantly differentially phosphorylated upon exposure of S. mansoni to the human cytokine, we incubated male adult worms for 15 min in culture with human TNF-alpha (20 ng / ml), or with vehicle only, in controls, and we extracted total proteins from the parasites. We used the phosphoproteomics approach of bidimensional gel electrophoresis followed by phospho-specific staining of gels using Pro-Q Diamond dye (Invitrogen). To identify which proteins were phosphorylated or had their phosphorylation changed due to the treatment, we quantified the spots (determined the spots volumes) from Pro-Q stained gels using Image Master 2D Platinum software (GE). A total protein staining of the gels was performed using Coomassie Brilliant Blue (CBB) in order to localize all protein spots in the gel. We excised from CBB stained gels the protein spots that showed statistically significant changes in phosphorylation (n= 3 replicates; p-value<0.05, t-test), based on the relative volumes of their spot images with respect to the total volume of spots in the gel, with samples from treated compared to control parasites, and subsequently the proteins in these samples were identified by mass spectrometry. We have analyzed three biological replicates and observed 45 spots that were differentially phosphorylated; 42 of them had their phosphorylation increased and 3 had their phosphorylation decreased upon a 15-min-treatment of male adult worms with the cytokine. Among the spots identified by mass spectrometry, we found proteins related to metabolic process, cell signaling, and cytoskeleton and muscle contraction. Although the experimental approach adopted for this study was not sensitive enough to conclude which canonical signal transduction pathway is activated by human TNF-alpha in S. mansoni, this kind of study confirmed the increase in phosphorylation of target proteins induced by human TNF-alpha, opening new paths for further investigation in order to characterize the role of the proteins identified as altered by this specific signaling, which will lead to a better understanding of the importance of this cytokine in the biology of S. mansoni and in host-parasite interaction.