In this study, the effects of antagonists to the cannabinoid receptors in MCL cell lines were studied. Results presented in this study show that signalling through cannabinoid receptor with antagonists such as SR141716, SR144528 decreases cell viability but hemopressin when analyzing with XTT. The decrease in cell viability by SR141716 is caused by apoptosis triggered after 5 hours of treatment. The CB1 expression was confirmed in all MCL cell lines tested via western blotting but the expression of CB2 and GPR55 – another receptor to which SR141716 has affinity - was not confirmed due to lack of reliable antibodies. Specific agonist to GPR55 – LPI (l-α-lysophosphatidylinositol) showed different response compared to SR141716 which suggests that the effect seen by SR141716 was not induced through GPR55. The effect induced by CB1/CB2 agonist AEA is shown to be neither through CB1 or CB2 alone but possibly on another receptor yet to be described.

A neuropatia periférica diabética é caracterizada por hiperalgesia e alodínia. O receptor CB1 é o principal responsável pelo efeito dos canabinóides na via nociceptiva. A Hemopressina (Hp), é um agonista inverso do CB1, que induz antinocicepção. Neste trabalho investigamos o efeito do tratamento com Hp (2,5 mg/Kg, por 28 dias) sobre a neuropatia diabética de camundongos, induzido por estreptozotocina (200mg/kg). A Hp reverte a hipersensibilidade mecânica em camundongos com neuropatia diabética, sendo que este efeito é específico para o tratamento da nocicepção e envolve a participação de receptores CB1, astrócitos e microglia em nível espinal. A Hp também previne a desmielinização do nervo isquiático dos animais diabéticos, e auxilia na manutenção dos níveis do NGF. Ainda, a Hp participa no controle da sensibilidade ao estímulo térmico quente em animais KO MOR e participa do controle da sensibilidade mecânica de animais KO MOR diabéticos pelo aumento da dimerização de CB1-DOR na medula espinal. Revelando a Hp um candidato para fins terapêuticos. / Diabetic peripheral neuropathy is characterized by hyperalgesia and allodynia. CB1 receptors are primarily responsible for the effect of cannabinoids in nociceptive pathways. Hemopressin (Hp) is an inverse agonist of CB1, which induces antinociception. In this study we investigated the effects of treatment with Hp (2.5 mg / kg for 28 days) on mice subjected to diabetic neuropathy by streptozotocin (STZ - 200 mg/kg). Hp treatement reversed the mechanical hypersensitivity in mice with neuropathy diabetic, and this effect is specific for the treatment of nociception and involves the participation of CB1 receptors, astrocytes and microglia at the spinal level. Hp prevented demyelination of the sciatic nerve in diabetic animals, and assisted in mantaining the levels of NGF. Also, Hp participates in the control of heat sensitivity to thermal stimulus in KO MOR animals and participates in the control of mechanical sensitivity in KO MOR diabetics animals by the increase in CB1-DOR dimerization in the spinal cord. Revealing Hp as a candidate for therapeutic purposes.

A neuropatia periférica diabética é caracterizada por hiperalgesia e alodínia. O receptor CB1 é o principal responsável pelo efeito dos canabinóides na via nociceptiva. A Hemopressina (Hp), é um agonista inverso do CB1, que induz antinocicepção. Neste trabalho investigamos o efeito do tratamento com Hp (2,5 mg/Kg, por 28 dias) sobre a neuropatia diabética de camundongos, induzido por estreptozotocina (200mg/kg). A Hp reverte a hipersensibilidade mecânica em camundongos com neuropatia diabética, sendo que este efeito é específico para o tratamento da nocicepção e envolve a participação de receptores CB1, astrócitos e microglia em nível espinal. A Hp também previne a desmielinização do nervo isquiático dos animais diabéticos, e auxilia na manutenção dos níveis do NGF. Ainda, a Hp participa no controle da sensibilidade ao estímulo térmico quente em animais KO MOR e participa do controle da sensibilidade mecânica de animais KO MOR diabéticos pelo aumento da dimerização de CB1-DOR na medula espinal. Revelando a Hp um candidato para fins terapêuticos. / Diabetic peripheral neuropathy is characterized by hyperalgesia and allodynia. CB1 receptors are primarily responsible for the effect of cannabinoids in nociceptive pathways. Hemopressin (Hp) is an inverse agonist of CB1, which induces antinociception. In this study we investigated the effects of treatment with Hp (2.5 mg / kg for 28 days) on mice subjected to diabetic neuropathy by streptozotocin (STZ - 200 mg/kg). Hp treatement reversed the mechanical hypersensitivity in mice with neuropathy diabetic, and this effect is specific for the treatment of nociception and involves the participation of CB1 receptors, astrocytes and microglia at the spinal level. Hp prevented demyelination of the sciatic nerve in diabetic animals, and assisted in mantaining the levels of NGF. Also, Hp participates in the control of heat sensitivity to thermal stimulus in KO MOR animals and participates in the control of mechanical sensitivity in KO MOR diabetics animals by the increase in CB1-DOR dimerization in the spinal cord. Revealing Hp as a candidate for therapeutic purposes.

The obesity epidemic is a major health threat affecting one in four people in the affluent western world, where high-energy foods are easily available and there is little need for exercise. To identify novel therapeutic targets for the treatment of obesity, one important step is to further define the complex circuitry in the brainwhich is ultimately responsible for our appetite and body weight regulation. Although complex, appetite can be thought of as having two distinct, though none mutually exclusive, aspects: the need to eat (homeostatic) and the desire to eat(hedonistic).The need to eat, a product of energy homeostasis, is what drives the consumption offood for basic survival. In an attempt to further define the mainly “homeostatic” neuronal circuitry, we combined blood-oxygen-level-dependent (BOLD)pharmacological-challenge magnetic resonance imaging (phMRI) with c-Fosfunctional activity mapping to characterise “whole brain” responsiveness to anorexigenic dose of the glucose anti metabolite 2-deoxy-D-glucose (2-DG). Using thesecomplementary methods, we demonstrated functional brain activity in a number ofknown glucose-sensing brain regions, including parts of the hypothalamus andbrainstem, following administration of 2-DG when compared with vehicle treatment.The desire to eat is a result of a complex interplay between the reward andmotivational circuits implicated in addictive behaviours, and those which controlenergy homeostasis. Recent research has pointed to the endocannabinoid system,and specifically the central cannabinoid 1 (CB1) receptor, as a key target mediatingthe functional cross talk between the two appetitive systems. To define the sites ofaction of cannabinoids, we used an orexigenic dose of the full CB1 agonist, CP55940,to map responsive brain regions again using BOLD phMRI and whole-brain c-Fosfunctional activity mapping. Areas of interest demonstrated a drug interaction whenthe CB1 receptor inverse agonist, Rimonabant was co-administered. These complementary methods demonstrated functional activity in the cortico-striatalhypothalamicpathway, a key system in the motivational drive to eat.The appetitive actions of synthetic CB1 inverse agonists such as Rimonabant are welldocumented. We, however, described a putative novel endogenous CB1 inverseagonist, hemopressin, which is the first identified peptide ligand of CB1 receptors.We showed that hemopressin inhibits agonist-induced receptor internalisation in aheterologous cell model in vitro. When administered centrally or systemically in vivo,we found that hemopressin decreases nocturnal food intake in out-bred rats andmice, as well as in obese, leptin-deficient ob/obmice. Importantly, hemopressininduces hypophagia without causing any apparent adverse side effects. We have also shown that the anorectic effect is absent in CB1-/- mice, and that hemopressin canblock CB1 agonist-induced hyperphagia in male rats, providing strong evidence forantagonism of the CB1 receptor in vivo. We speculate that hemopressin may be one of a family of endogenous functional CB1 receptor ligands that modulate the activity of appetite pathways in the brain.

A artrite reumatóide (AR) representa uma doença inflamatória crônica de alta prevalência, para a qual ainda não foi estabelecido um tratamento satisfatório. Os objetivos deste estudo foram: 1) investigar o efeito terapêutico da hemopressina e da depleção de neuropeptídeos sobre a artrite induzida por antígeno (AIA); 2) padronizar este modelo em duas linhagens de ratos: Wistar e Sprague Dawley (SD). Ambas as linhagens, exibiram sinais equipotententes de edema e dor; entretanto, a perda de peso, o infiltrado celular e a produção de citocinas foi maior no rato SD, sugerindo uma maior susceptibilidade do SD. O tratamento com hemopressina inibiu esses sinais inflamatórios, mas não preveniu a perda de peso e a gênese de citocinas. Em contraste, a depleção de neuropeptídeos falhou em suprimir os sinais da AIA, excluindo a participação de mecanismos neurovasculares na ação da hemopressina. Embora ainda não estabelecido o mecanismo de ação do efeito anti-artrítico da hemopressina, este achado inédito sugere uma alternativa promissora para o tratamento dessa doença. / Arthritis and other rheumatic conditions are among the most prevalent diseases worldwide and the most frequent cause of disability. There are many treatment options, but an effective treatment has not been established. Our aims were to investigate a possible anti-inflammatory effect of hemopressin and neuropeptide depletion on Met-BSA induced arthritis (AIA); and to establish a suitable rat strain between Wistar and Sprague Dawley (SD) for the study. The classical signs of AIA such as oedema and pain were similar in both strains. But, the cell influx and cytokines production were higher in SD, thus suggesting a higher susceptibility for this strain. The treatment of rats with hemopressin greatly reduced the oedema, pain and cell influx, but did not prevent the body weight loss and cytokines. Depletion of neuropeptides failed to reduce the AIA signs, thus excluding a neurogenic component on hemopressin-induced effect. In conclusion, our findings reveal a potential alternative treatment for arthritis, although the mechanism of action for this peptide is not clear.

A artrite reumatóide (AR) representa uma doença inflamatória crônica de alta prevalência, para a qual ainda não foi estabelecido um tratamento satisfatório. Os objetivos deste estudo foram: 1) investigar o efeito terapêutico da hemopressina e da depleção de neuropeptídeos sobre a artrite induzida por antígeno (AIA); 2) padronizar este modelo em duas linhagens de ratos: Wistar e Sprague Dawley (SD). Ambas as linhagens, exibiram sinais equipotententes de edema e dor; entretanto, a perda de peso, o infiltrado celular e a produção de citocinas foi maior no rato SD, sugerindo uma maior susceptibilidade do SD. O tratamento com hemopressina inibiu esses sinais inflamatórios, mas não preveniu a perda de peso e a gênese de citocinas. Em contraste, a depleção de neuropeptídeos falhou em suprimir os sinais da AIA, excluindo a participação de mecanismos neurovasculares na ação da hemopressina. Embora ainda não estabelecido o mecanismo de ação do efeito anti-artrítico da hemopressina, este achado inédito sugere uma alternativa promissora para o tratamento dessa doença. / Arthritis and other rheumatic conditions are among the most prevalent diseases worldwide and the most frequent cause of disability. There are many treatment options, but an effective treatment has not been established. Our aims were to investigate a possible anti-inflammatory effect of hemopressin and neuropeptide depletion on Met-BSA induced arthritis (AIA); and to establish a suitable rat strain between Wistar and Sprague Dawley (SD) for the study. The classical signs of AIA such as oedema and pain were similar in both strains. But, the cell influx and cytokines production were higher in SD, thus suggesting a higher susceptibility for this strain. The treatment of rats with hemopressin greatly reduced the oedema, pain and cell influx, but did not prevent the body weight loss and cytokines. Depletion of neuropeptides failed to reduce the AIA signs, thus excluding a neurogenic component on hemopressin-induced effect. In conclusion, our findings reveal a potential alternative treatment for arthritis, although the mechanism of action for this peptide is not clear.