Efeito dos glicosaminoglicanos (GAGs) sobre a progressão do glioma C6: abordagens in vitro e in vivo /

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas.O presente estudo tem por objetivo verificar efeitos dos glicosaminoglicanos sobre a adesão in vitro do glioma C6. Analisamos também, os efeitos da subsulfatação dos GAGs na implantação intracerebral do glioma. Sendo a adesão um passo crítico para o estabelecimento inicial tumoral, realizamos ensaios de adesão celular para testar propriedades de proteínas da Matriz Extracelular (MEC) (laminina, fibronectina e colágeno tipo IV), assim como de GAGs (heparina e condroitin-sulfato) na adesão das célula C6 em placas de ELISA. As proteínas da MEC estimularam a adesão de C6 de modo crescente. A heparina apresentou diferentes efeitos de interação com cada proteína da MEC testada, inibindo a adesão a laminina, aumentando a colágeno IV e não alterando a Fibronectina. Por outro lado, a presença de condroitin-sulfato reduziu a adesão de C6 de modo dose-dependente, às três proteínas testadas. Os experimentos de pré-incubação da heparina às proteínas da MEC ou às células, podem sugerir que interações entre a MEC e GAGs podem ser específicas para determinar a adesão celular. Trabalhos anteriores do nosso laboratório mostraram que o tratamento in vitro de células C6 com clorato de sódio (inibidor de sulfatação de GAGs) reduz a adesão e a proliferação de um modo dose-dependente sem induzir morte celular. Assim, nós testamos os efeitos do tratamento in vivo com o clorato de sódio sobre o crescimento do glioma C6, e procuramos verificar alguns aspectos imunológicos. Realizamos inoculações subcutâneas (2 X 107 células) e intracerebrais (1 X 105 células) de células C6 e analisamos os hemogramas, testes anatomopatológicos, histopatológicos, de sobrevivência e de comportamento. No tratamento local subcutâneo, clorato de sódio revelou ser eficiente em reduzir o crescimento tumoral 30 dias após a inoculação de células C6. Nas inoculações intracerebrais, o pré-tratamento de células C6 com clorato de sódio e tratamento posterior no sítio tumoral, reduziu o crescimento do glioma, revelado pelos testes de sobrevivência e histopatologia. Sensibilizações prévias, intraperitoneais, com células C6 pré-tratadas com clorato de sódio ou com células controle, inibiram o crescimento do glioma após a inoculação intracerebral de células C6, como mostrado nos experimentos de sobrevivência e nas histopatologias. Os hemogramas revelaram uma redução linfocitária 24 e 28 dias após a inoculação intracerebral de C6, porém sem diferenças na leuco e linfometria entre os grupos sensibilizados, entre si e em relação ao controle. Os testes comportamentais revelaram redução em parâmetros exploratórios nos animais inoculados intracerebralmente com C6 quando comparados com o grupo que recebeu C6 pré-tratado com clorato de sódio ou com o grupo controle-operado(sham). Estes resultados sugerem que a sulfatação dos GAGs pode ser importante para o estabelecimento e progressão do glioma C6 in vivo

Glycosaminoglycans modulate C6 glioma cell adhesion to extracellular matrix components and alter cell proliferation and cell migration

BACKGROUND: Adhesion to extracellular matrix (ECM) components has been implicated in the proliferative and invasive properties of tumor cells. We investigated the ability of C6 glioma cells to attach to ECM components in vitro and described the regulatory role of glycosaminoglycans (GAGs) on their adhesion to the substrate, proliferation and migration. RESULTS: ECM proteins (type IV collagen, laminin and fibronectin) stimulate rat C6 glioma cell line adhesion in vitro, in a dose-dependent manner. The higher adhesion values were achieved with type IV collagen. Exogenous heparin or chondroitin sulfate impaired, in a dose-dependent manner the attachment of C6 glioma cell line to laminin and fibronectin, but not to type IV collagen. Dextran sulfate did not affect C6 adhesion to any ECM protein analyzed, indicating a specific role of GAGs in mediating glioma adhesion to laminin and fibronectin. GAGs and dextran sulfate did not induce C6 glioma detachment from any tested substrate suggesting specific effect in the initial step of cell adhesion. Furthermore, heparin and chondroitin sulfate impaired C6 cells proliferation on fibronectin, but not on type IV collagen or laminin. In contrast, both GAGs stimulate the glioma migration on laminin without effect on type IV collagen or fibronectin. CONCLUSION: The results suggest that GAGs and proteoglycans regulate glioma cell adhesion to ECM proteins in specific manner leading to cell proliferation or cell migration, according to the ECM composition, thus modulating tumor cell properties

Enhancement of blood-tumor barrier permeability by Sar-[D-Phe8]des-Arg9BK, a metabolically resistant bradykinin B1 agonist, in a rat C6 glioma model

BACKGROUND: While it is well known that bradykinin B2 agonists increase plasma protein extravasation (PPE) in brain tumors, the bradykinin B1 agonists tested thus far are unable to produce this effect. Here we examine the effect of the selective B1 agonist bradykinin (BK) Sar-[D-Phe8]des-Arg9BK (SAR), a compound resistant to enzymatic degradation with prolonged activity on PPE in the blood circulation in the C6 rat glioma model. RESULTS: SAR administration significantly enhanced PPE in C6 rat brain glioma compared to saline or BK (p < 0.01). Pre-administration of the bradykinin B1 antagonist [Leu8]-des-Arg (100 nmol/Kg) blocked the SAR-induced PPE in the tumor area. CONCLUSIONS: Our data suggest that the B1 receptor modulates PPE in the blood tumor barrier of C6 glioma. A possible role for the use of SAR in the chemotherapy of gliomas deserves further study

Pathophysiology of major depression by clinical stages

The comprehension of the pathophysiology of the major depressive disorder (MDD) is essential to the strengthening of precision psychiatry. In order to determine the relationship between the pathophysiology of the MDD and its clinical progression, analyzed by severity of the depressive symptoms and sleep quality, we conducted a study assessing different peripheral molecular biomarkers, including the levels of plasma C-reactive protein (CRP), serum mature brain-derived neurotrophic factor (mBDNF), serum cortisol (SC), and salivary cortisol awakening response (CAR), of patients with MDD (n = 58) and a control group of healthy volunteers (n = 62). Patients with the first episode of MDD (n = 30) had significantly higher levels of CAR and SC than controls (n = 32) and similar levels of mBDNF of controls. Patients with treatment-resistant depression (TRD, n = 28) presented significantly lower levels of SC and CAR, and higher levels of mBDNF and CRP than controls (n = 30). An increased severity of depressive symptoms and worse sleep quality were correlated with levels low of SC and CAR, and with high levels of mBDNF. These results point out a strong relationship between the stages clinical of MDD and changes in a range of relevant biological markers. This can assist in the development of precision psychiatry and future research on the biological tests for depression

Cortisol modulation by ayahuasca in patients with treatment resistant depression and healthy controls

Major depression is a highly prevalent mood disorder, affecting about 350 million people, and around 30% of the patients are resistant to currently available antidepressant medications. Recent evidence from a randomized controlled trial (RCT) supports the rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression. The aim of this study was to explore the effect of ayahuasca on plasma cortisol and awakening salivary cortisol response, in the same group of treatment-resistant patients (MD) and in healthy volunteers (C). Subjects received a single dose of ayahuasca or placebo (dosing session), and both plasma and awakening salivary cortisol response were measured at baseline (before dosing session) and 48 h after the dosing session. Baseline assessment (D0) showed blunted awakening salivary cortisol response and hypocortisolemia in patients, with respect to healthy controls. Salivary cortisol was also measured during dosing session, and we observed higher increases for both C and MD that ingested ayahuasca than placebo. After 48 h from the dosing session with ayahuasca, patients' awakening salivary cortisol response is similar to the ones detected in controls. No significant changes in plasma cortisol levels were observed 48 h after the sessions. Therefore, these findings point to new evidence on the modulation of salivary cortisol levels as a result of an ayahuasca session, both in healthy and depressive volunteers. Considering that cortisol acts in regulation of distinct physiological pathways, emotional and cognitive processes, it is assumed to be critically involved to the etiology of depression and its regulation seems to be important for the treatment and remission of major depression, ayahuasca use as antidepressant should be further investigated. Moreover, this study highlights the importance of psychedelics in the treatment of human mental disorders

Moderators of ayahuasca’s biological antidepressant action

IntroductionThe understanding of biological responses to psychedelics with antidepressant potential is imperative. Here we report how a set of acute parameters, namely emotional (depressive symptoms), cognitive (psychedelic experience), and physiological (salivary cortisol), recorded during an ayahuasca dosing session, modulated serum brain-derived neurotrophic factor (BDNF), serum cortisol (SC), serum interleukin 6 (IL-6), plasma C-reactive protein (CRP), and salivary cortisol awakening response (CAR).MethodsResults were analyzed 2 days after the psychedelic intervention (ayahuasca) versus placebo in both patients with treatment-resistant depression and healthy volunteers. These measures were assessed as part of a randomized double-blinded, placebo-controlled trial (n = 72).ResultsResults revealed that larger reductions of depressive symptoms during the dosing session significantly moderated higher levels of SC in patients. Whereas lesser changes in salivary cortisol levels during the ayahuasca intervention were related to higher BDNF levels in patients with a larger clinical response in the reduction in depressive symptoms. No moderator was found for patient’s CAR, IL-6, and CRP responses to ayahuasca and for all biomarker responses to ayahuasca in healthy controls and in the placebo group.DiscussionIn summary, some specific emotional and physiological parameters during experimental ayahuasca session were revealed as critical moderators of the improvement of major depression biomarkers, mainly BDNF and SC two days after ayahuasca intake. These findings contribute to paving the way for future studies investigating the biological antidepressant response to psychedelic therapy

Rapid antidepressant effects of the psychedelic ayahuasca in treatment-resistant depression: a randomized placebo-controlled trial

Background Recent open-label trials show that psychedelics, such as ayahuasca, hold promise as fast-onset antidepressants in treatment-resistant depression. Methods To test the antidepressant effects of ayahuasca, we conducted a parallel-arm, double-blind randomized placebo-controlled trial in 29 patients with treatment-resistant depression. Patients received a single dose of either ayahuasca or placebo. We assessed changes in depression severity with the Montgomery-Åsberg Depression Rating Scale (MADRS) and the Hamilton Depression Rating scale at baseline, and at 1 (D1), 2 (D2), and 7 (D7) days after dosing. Results We observed significant antidepressant effects of ayahuasca when compared with placebo at all-time points. MADRS scores were significantly lower in the ayahuasca group compared with placebo at D1 and D2 (p = 0.04), and at D7 (p < 0.0001). Between-group effect sizes increased from D1 to D7 (D1: Cohen's d = 0.84; D2: Cohen's d = 0.84; D7: Cohen's d = 1.49). Response rates were high for both groups at D1 and D2, and significantly higher in the ayahuasca group at D7 (64% v. 27%; p = 0.04). Remission rate showed a trend toward significance at D7 (36% v. 7%, p = 0.054). Conclusions To our knowledge, this is the first controlled trial to test a psychedelic substance in treatment-resistant depression. Overall, this study brings new evidence supporting the safety and therapeutic value of ayahuasca, dosed within an appropriate setting, to help treat depression. This study is registered at http://clinicaltrials.gov (NCT02914769)

Efeito dos glicosaminoglicanos (GAGs) sobre a progressão do glioma C6

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas.O presente estudo tem por objetivo verificar efeitos dos glicosaminoglicanos sobre a adesão in vitro do glioma C6. Analisamos também, os efeitos da subsulfatação dos GAGs na implantação intracerebral do glioma. Sendo a adesão um passo crítico para o estabelecimento inicial tumoral, realizamos ensaios de adesão celular para testar propriedades de proteínas da Matriz Extracelular (MEC) (laminina, fibronectina e colágeno tipo IV), assim como de GAGs (heparina e condroitin-sulfato) na adesão das célula C6 em placas de ELISA. As proteínas da MEC estimularam a adesão de C6 de modo crescente. A heparina apresentou diferentes efeitos de interação com cada proteína da MEC testada, inibindo a adesão a laminina, aumentando a colágeno IV e não alterando a Fibronectina. Por outro lado, a presença de condroitin-sulfato reduziu a adesão de C6 de modo dose-dependente, às três proteínas testadas. Os experimentos de pré-incubação da heparina às proteínas da MEC ou às células, podem sugerir que interações entre a MEC e GAGs podem ser específicas para determinar a adesão celular. Trabalhos anteriores do nosso laboratório mostraram que o tratamento in vitro de células C6 com clorato de sódio (inibidor de sulfatação de GAGs) reduz a adesão e a proliferação de um modo dose-dependente sem induzir morte celular. Assim, nós testamos os efeitos do tratamento in vivo com o clorato de sódio sobre o crescimento do glioma C6, e procuramos verificar alguns aspectos imunológicos. Realizamos inoculações subcutâneas (2 X 107 células) e intracerebrais (1 X 105 células) de células C6 e analisamos os hemogramas, testes anatomopatológicos, histopatológicos, de sobrevivência e de comportamento. No tratamento local subcutâneo, clorato de sódio revelou ser eficiente em reduzir o crescimento tumoral 30 dias após a inoculação de células C6. Nas inoculações intracerebrais, o pré-tratamento de células C6 com clorato de sódio e tratamento posterior no sítio tumoral, reduziu o crescimento do glioma, revelado pelos testes de sobrevivência e histopatologia. Sensibilizações prévias, intraperitoneais, com células C6 pré-tratadas com clorato de sódio ou com células controle, inibiram o crescimento do glioma após a inoculação intracerebral de células C6, como mostrado nos experimentos de sobrevivência e nas histopatologias. Os hemogramas revelaram uma redução linfocitária 24 e 28 dias após a inoculação intracerebral de C6, porém sem diferenças na leuco e linfometria entre os grupos sensibilizados, entre si e em relação ao controle. Os testes comportamentais revelaram redução em parâmetros exploratórios nos animais inoculados intracerebralmente com C6 quando comparados com o grupo que recebeu C6 pré-tratado com clorato de sódio ou com o grupo controle-operado(sham). Estes resultados sugerem que a sulfatação dos GAGs pode ser importante para o estabelecimento e progressão do glioma C6 in vivo