No description available.

No description available.

Two polymorphisms in the promoter region of macrophage migration inhibitory factor (MIF)—rs755622 and rs5844572—exhibit prognostic relevance in inflammatory diseases. The aim of this study was to investigate a correlation between these MIF promoter polymorphisms and the severity of hepatitis C virus (HCV)-induced liver fibrosis. Our analysis included two independent patient cohorts with HCV-induced liver fibrosis (504 and 443 patients, respectively). The genotype of the single nucleotide polymorphism (SNP) -173 G/C and the repeat number of the microsatellite polymorphism -794 CATT5–8 were determined in DNA samples and correlated with fibrosis severity. In the first cohort, homozygous carriers of the C allele in the rs755622 had lower fibrosis stages compared to heterozygous carriers or wild types (1.25 vs. 2.0 vs. 2.0; p = 0.03). Additionally, 7 microsatellite repeats were associated with lower fibrosis stages (<F2) (p = 0.04). Comparable tendencies were observed in the second independent cohort, where fibrosis was assessed using transient elastography. However, once cirrhosis had been established, the C/C genotype and higher microsatellite repeats correlated with impaired liver function and a higher prevalence of hepatocellular carcinoma. Our study demonstrates that specific MIF polymorphisms are associated with disease severity and complications of HCV-induced fibrosis in a stage- and context-dependent manner.

Submitted by Ronildo Prado (ronisp@ufscar.br) on 2017-08-22T18:04:35Z No. of bitstreams: 1 DissRMB.pdf: 1290621 bytes, checksum: 3870f44730785bfd4b123df5cbec0b90 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-22T18:04:45Z (GMT) No. of bitstreams: 1 DissRMB.pdf: 1290621 bytes, checksum: 3870f44730785bfd4b123df5cbec0b90 (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2017-08-22T18:04:52Z (GMT) No. of bitstreams: 1 DissRMB.pdf: 1290621 bytes, checksum: 3870f44730785bfd4b123df5cbec0b90 (MD5) / Made available in DSpace on 2017-08-22T18:04:59Z (GMT). No. of bitstreams: 1 DissRMB.pdf: 1290621 bytes, checksum: 3870f44730785bfd4b123df5cbec0b90 (MD5) Previous issue date: 2015-08-31 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / The high blood pressure levels reach about 22% of the world population, increasing the risk factors for coronary disease, heart attack and heart failure. Many studies have tried to understand the causes of hypertension and possible mechanisms to facilitate the treatment of hypertension. The central nervous system seems to play a key role in the development and maintenance of hypertension. Among the various brain areas, we can highlight the role of the nucleus of the solitary tract (NTS), which is the primary site of visceral afferents. The macrophage migration inhibitory factor (MIF) is an intracellular inhibitory regulator of the actions of angiotensin II (ANG II) in the ANG II type 1 receptors. The spontaneously hypertensive rats (SHRs) and the rats with renovascular hypertension 2 kidney, 1 clip (2K1C) exhibit an increased activity of the renin-angiotensin system, increased sympathetic activity and reduced baroreflex function. We recently demonstrated that MIF overexpression in the NTS of SHRs lowers blood pressure of these animals and improved the function of the baroreflex. Therefore, in this study we tested if increased expression of MIF in the NTS of the 2K1C rats could alter the development of hypertension and improve the baroreflex function in these animals. For this, the left renal artery was partially obstructed in male Holtzman rats (150-180 g) using a silver clip (0.2 mm width) to induce 2K1C hypertension (n = 5-10/group) or sham surgery [normotensive rats (NT); n = 5-11/group] was performed. Three weeks after renal clip placement or sham surgery, rats received AAV2-CBA-MIF microinjections into the NTS to increase MIF expression in the area or AAV2-CBA-eGFP, which promoted the expression of GFP (enhanced green protein), which served as a control vector. Arterial pressure and heart rate were recorded by telemetry and baroreflex tests were performed. At the end of the experiments, the brains were harvested for immunohistochemistry RT-PCR. MIF injections into the NTS attenuated the hypertension in 2K1C rats from 2 weeks after viral transfection until the end of the experiment (4 weeks after viral transfection), (2K1C-MIF: 145 ± 7, vs. 2K1C-eGFP: 176 ± 9 mmHg; p < 0.05). MIF into the NTS also improved the reflex bradycardia (2K1C-MIF slope: -1.4 ± 0.3, vs. 2K1C-eGPF slope: -0.41 ± 0.3 bpm/mmHg; p < 0.05) and reflex tachycardia (2K1C-MIF slope: -4.7 ± 0.6, vs. 2K1C-eGPF slope: -1.7 ± 0.3 bpm/mmHg; p < 0.05). Baseline heart rate was decreased in 2K1C-MIF rats. In contrast to 2K1C rats, MIF overexpressed in the NTS in normotensive rats produced no change in arterial pressure neither baroreflex function. As expected, the transduction of MIF in the NTS increased mRNA levels for MIF at the same site (NT-MIF: 3.80 ± 0.97, vs. NT-eGFP: 1.00 ± 0.16 fold change and 2K1C-MIF: 3.53 ± 0.68, vs. 2K1C-eGFP: 0.88 ± 0.09 fold change; p < 0.05). These results suggest that increased expression of MIF in neurons within NTS attenuates the hypertension and improves baroreflex function in 2K1C rats, possibly through anti-ANG II actions. / Os altos níveis de pressão arterial atingem cerca de 22% da população mundial, aumentando os fatores de risco para doenças coronarianas, infarto e falência cardíaca. Muitos estudos tentam entender as causas da hipertensão e os possíveis mecanismos que facilitem o tratamento da hipertensão. O sistema nervoso central parece ter um papel chave no desenvolvimento e na manutenção da hipertensão. Dentre as diversas áreas encefálicas, podemos destacar o papel do núcleo do trato solitário (NTS), que é o sítio primário das aferências viscerais. O fator inibitório da migração de macrófagos (MIF) é um regulador inibitório intracelular das ações da angiotensina II (ANG II) em receptores do subtipo AT1. Os ratos espontaneamente hipertensos (SHR) bem como os ratos com hipertensão renovascular 2 rins, 1 clipe (2R1C), exibem uma atividade aumentada do sistema renina-angiotensina, do sistema nervoso simpático e uma diminuição da função do barorreflexo. Recentemente demonstramos que a super-expressão de MIF no NTS de SHRs reduziu a pressão arterial destes animais bem como melhorou a função do barorreflexo. Portanto, neste estudo testamos se a expressão aumentada de MIF no NTS de ratos 2R1C poderia altenuar o desenvolvimento da hipertensão e melhorar a função do barorreflexo nestes animais. Para tanto, a artéria renal esquerda foi parcialmente obstruída em ratos Holtzman (150-180 g) utilizando um clipe de prata (0,2 mm de abertura) para induzir a hipertensão 2R1C (n = 5-10/grupo) ou a cirurgia fictícia [ratos normotensos (NT); n = 5-11/grupo] foi realizada. Três semanas após a inserção do clipe renal ou após a cirurgia fictícia, os ratos receberam microinjeções do vetor viral AAV2-CBA-MIF no NTS para aumentar a expressão de MIF na área ou de AAV2-CBA-eGFP, que promoveu a expressão de GFP (proteína fluorescente verde), que serviu como vetor controle. A pressão arterial e a frequência cardíaca foram registradas por telemetria e testes do barorreflexo foram realizados. Ao término dos experimentos, os encéfalos foram colhidos para imunohistoquímica ou RT-PCR. As microinjeções de MIF no NTS atenuaram a hipertensão em ratos 2R1C a partir de 2 semanas após a transfecção viral até o fim dos experimentos (4 semanas após a transfecção), (2R1C-MIF: 145 ± 7, vs. 2R1C-eGFP: 176 ± 9 mmHg; p < 0,05). MIF no NTS também melhorou a bradicardia reflexa (2R1C-MIF slope: -1,4 ± 0,3, vs. 2R1C-eGFP slope: -0,41 ± 0,3 bpm/mmHg; p < 0,05) e taquicardia reflexa (2R1C-MIF slope: -4,7 ± 0,6, vs. 2R1C-eGFP slope: -1,7 ± 0,3 bpm/mmHg; p < 0,05). A frequência cardíaca basal foi diminuída em ratos 2R1C-MIF. Em contraste com os ratos 2R1C, MIF super-expresso no NTS de ratos normotensos não produziu alteração na pressão arterial ou na função do barorreflexo. Como esperado, a transdução de MIF no NTS aumentou os níveis de RNAm para MIF no mesmo local (NT-MIF: 3,80 ± 0,97, vs. NT-eGFP: 1,00 ± 0,16 número de vezes e 2R1C-MIF: 3,53 ± 0,68, vs. 2R1C-eGFP: 0,88 ± 0,09 número de vezes; p < 0,05). Estes resultados sugerem que a expressão aumentada de MIF nos neurônios do NTS atenua a hipertensão, melhora a função do barorreflexo em ratos 2R1C, possivelmente através de uma ação anti-ANG II. / FAPESP: 2013/02607-0

Στην παρούσα διατριβή μελετήθηκε η έκφραση του παράγοντα αναστολής της μετανάστευσης των μακροφάγων (MIF) στον ιστό από ρινικό πολύποδα αλλά και στον φυσιολογικό ρινικό βλεννογόνο, καθώς και η ικανότητα αυτού να εξουδετερώνει την ανασταλτική δράση των γλυκοκορτικοειδών (ΓΚ) στην επαγόμενη από διάφορους αυξητικούς παράγοντες παραγωγή διαμεσολαβητών, όπως η IL-6 η MMP-1, η MMP-3 το κολλαγόνο τύπου-Ι και ο TIMP-1, που εμπλέκονται στη παθογένεια του ρινικού πολύποδα (ΡΠ). Ο MIF ανιχνεύθηκε στο μέσο καλλιέργειας όλων των ιστών και σε όλα τα εκχυλίσματα. Η έκφρασή του ήταν αυξημένη στον ρινικό πολύποδα σε σχέση με τον φυσιολογικό ρινικό βλεννογόνο. O TGF-β1 προκάλεσε δοσο- και χρονο-εξαρτώμενη αύξηση των επιπέδων της IL-6 του TIMP-1 και του κολλαγόνου τύπου-Ι, και παράλληλα ο TNF-α προκάλεσε δοσο- αλλά και χρονο-εξαρτώμενη διέγερση στην παραγωγή της IL-6 του TIMP-1 και των μεταλλοπρωτεασών MMP-1 και MMP-3. Η δεξαμεθαζόνη προκάλεσε στατιστικά σημαντική και δοσοεξαρτώμενη μείωση της επαγόμενης από τον TGF-β1 και TNF-α, παραγωγής της IL-6 του TIMP-1 του κολλαγόνου τύπου-Ι και των μεταλλοπρωτεασών MMP-1 και MMP-3. Διερευνώντας τον μηχανισμό μέσω του οποίου η δεξαμεθαζόνη ασκεί την κατασταλτική της δράση στην επαγόμενη τόσο από τον TGF-β1 όσο και από τον TNF-α, παραγωγή της IL-6, φάνηκε πως αυτή εκδηλώνεται κυρίως μέσω της επαγωγής αλλά και της προστασίας της ΜΚΡ-1 και κατά συνέπεια της καταστολής του μονοπατιού των ΜΑΡΚ και της ενεργοποίησης του ΑΡ-1, και λιγότερο μέσω της καταστολής της ενεργοποίησης του NF-κB. Ο ISO-1, ένας αναστολέας της δράσης του MIF, ενίσχυσε σημαντικά την κατασταλτική επίδραση της δεξαμεθαζόνης στα επίπεδα της IL-6 και του TIMP-1 στο μέσο καλλιέργειας ιστού από ΡΠ, ενώ αντίθετα προκάλεσε αναστροφή της κατασταλτικής δράσης της δεξαμεθαζόνης, η οποία ήταν στατιστικά σημαντική για την ΜΜΡ-1 όχι όμως και για την ΜΜΡ-3. Η ενίσχυση της κατασταλτικής δράσης της δεξαμεθαζόνης παρουσία του ISO-1, που κυμάνθηκε από 15.0% έως 20.5% θα πρέπει μάλλον να οφείλεται στην αναστολή του ενδογενούς MIF από τον ISO-1. Συμπερασματικά, η παρουσία του MIF στον ιστό του ρινικού πολύποδα, φαίνεται να εξασθενίζει το κατασταλτικό αποτέλεσμα της δεξαμεθαζόνης στην παραγωγή IL-6 και TIMP-1 από αυτόν τον ιστό, ενώ η ταυτόχρονη χρήση του αναστολέα του MIF, ISO-1 οδηγεί σε μια περαιτέρω ενίσχυση της κατασταλτικής δράσης της δεξαμεθαζόνης. Έτσι, είναι λογικό κατ΄αρχήν, να προταθεί πως η δημιουργία ενός φαρμακευτικού σχήματος που περιέχει κορτιζόλη και ένα αναστολέα του MIF, θα μπορούσε να είναι πιο αποτελεσματικό στην θεραπεία της ΡΠ. Απαιτούνται περαιτέρω πειράματα με συνδυασμό ΓΚ και αναστολέων του MIF για να μελετηθεί η επίδρασή τους στη παραγωγή και άλλων παραγόντων που εμπλέκονται στη παθογένεια της ΡΠ προκειμένου να εξαχθούν ασφαλέστερα συμπεράσματα. / In the present study we investigated the expression of macrophage migration inhibitory factor (MIF) in nasal polyp tissues and also in normal nasal mucosa. The ability of MIF to neutralize the inhibitory effect of glucocorticoids on various growth factors induced expression of IL-6, TIMP-1, collagen type-I and matrix metalloproteinases MMP-1 and MMP-3, involved in the pathogenesis of nasal polyps, was studied. MIF was detected in all polyp tissue extracts and tissue culture conditioned media and its expression was increased in nasal polyps compared with normal nasal mucosa. TGF-b1 caused a dose-and time-dependent increase in levels of IL-6 of TIMP-1 and collagen type-I, while the TNF-a induced a dose-and time-dependent stimulation in the production of IL-6 of TIMP-1 and metalloproteinases MMP-1 and MMP-3. Dexamethasone caused a statistically significant and dose-dependent reduction induced by TGF-b1 and TNF-a, production of IL-6 of TIMP-1 of collagen type-I and the metalloproteinases MMP-1 and MMP-3. Investigating the mechanism by which dexamethasone exercises the suppressive action on both induced by TGF-b1 and by TNF-a, production of IL-6, showed that this occurs mainly through the induction and protection of MKP-1 and hence the suppression of the MAPK pathway and activation of AP-1, and less through the suppression of the activation of NF-kB. The ISO-1, an inhibitor of the action of MIF, significantly enhanced the suppressive effect of dexamethasone on the levels of IL-6 and TIMP-1 in tissue culture medium from nasal polyps. In contrary, ISO-1 induced inversion of the suppresive action of dexamethasone, which was statistically significant for MMP-1 but not for MMP-3. Enhancing of the suppresive action of dexamethasone in the presence of ISO-1, which ranged from 15.0% to 20.5% would probably be due to inhibition of endogenous MIF by ISO-1. In conclusion, the presence of MIF in nasal polyp tissue, appears to attenuate the suppressor effect of dexamethasone on the production of IL-6 and TIMP-1by this tissue, while simultaneously using the inhibitor of MIF, ISO-1 leads to an enhancement of dexamethasone activity. Therefore, it is reasonable to propose that the creation of a pharmaceutical regimen containing cortisol and an inhibitor of MIF, might be more effective in the treatment of nasal polyposis. Of course, requires further experiments with a combination of glucocorticoids and MIF inhibitors to study their effect on production of other factors involved in the pathogenesis of nasal polyposis in order to draw safer conclusions.