Efeitos da administração intranasal de FPS-ZM1 na neuroinflamação e na interação com o receptor para produtos finais de glicação avançada em modelo animal de inflamação sistêmica

A neuroinflamação está presente em grande parte das doenças neurodegenerativas, muitas vezes atuando no desenvolvimento e na progressão destas. O Receptor para Produtos Finais de Glicação Avançada (RAGE) é uma proteína da superfamília das imunoglobulinas, capaz de modular a inflamação através da interação com seus ligantes, responsáveis por induzir a ativação de cascatas de sinalização pró-inflamatórias. Assim, elevados níveis de RAGE e de seus ligantes, como a CML, a HMGB1, a HSP70 e a S100B, acabam participando na manutenção e na propagação de quadros inflamatórios. Considerando o papel deste receptor na instauração e na sustentação da neuroinflamação, este trabalho descreve os efeitos da inibição do RAGE através do tratamento intranasal com seu antagonista FPS-ZM1, em um modelo animal de neuroinflamação crônica induzida por uma injeção intraperitoneal aguda de lipopolissacarídeo (LPS). 70 dias após a administração de LPS (2 mg/kg, i.p.), os ratos utilizados no estudo receberam intranasalmente, ao longo de 14 dias, 1,2 mg de FPS-ZM1. Nos dias 88 e 89, os animais foram submetidos ao Teste de Campo Aberto, sendo eutanasiados no dia 90 após a injeção i.p. do composto. Amostras de soro e de líquido cefalorraquidiano (CSF) foram coletadas: (i) para análise dos níveis de RAGE e de seus ligantes e (ii) para a investigação de perfis inflamatórios e oxidativos. De todos os analitos investigados, 90 dias após sua administração, o LPS provoca uma diminuição apenas dos níveis de corticosterona, e um aumento somente dos níveis de S100B, no soro e no CSF, respectivamente. O tratamento intranasal com FPS-ZM1 resgata o comportamento do tipo-depressivo/ansioso e os elevados níveis de S100B no CSF induzidos pela injeção de LPS, falhando em reverter a diminuição dos níveis de corticosterona no soro provocada pelo modelo. Este trabalho mostra que a inibição de RAGE, através do tratamento intranasal com seu inibidor farmacológico, FPS-ZM1, resgata características relacionadas à neuroinflamação; porém, não altera parâmetros relativos a quadros inflamatórios sistêmicos, sugerindo que o RAGE, a nível de SNC, possa estar associado ao desenvolvimento de estados neuroinflamatórios induzidos por condições de inflamação sistêmica.Neuroinflammation is a condition present in most neurodegenerative diseases, and it many times acts in both their development and progression. The Receptor for Advanced Glycation End Products (RAGE) is a protein of the immunoglobulin superfamily, capable of regulating inflammation through interaction with its ligands, which are responsible for inducing the activation of intracellular pro-inflammatory signaling cascades. Thus, high levels of RAGE and its ligands, such as CML, HMGB1, HSP70 and S100B, end up being accountable for the unfolding and maintenance of inflammatory conditions. Considering the role of this receptor in the establishment and upkeep of neuroinflammation, this study describes the effects of RAGE inhibition through an intranasal treatment with its antagonist FPS-ZM1, in an animal model of chronic neuroinflammation induced by an acute intraperitoneal injection of lipopolysaccharide (LPS). 70 days after LPS administration (2 mg / kg, i.p.), the rats used in the study received intranasally, over 14 days, 1.2 mg of FPS-ZM1. On days 88 and 89, the animals were submitted to the Open Field Test, being euthanized on day 90 after intraperitoneal injection of the compound. Serum and cerebrospinal fluid (CSF) samples were collected: (i) for the analysis of RAGE and their ligands levels, and (ii) for the study of the inflammatory and the oxidative status. Of all the analytes investigated, 90 days after its administration, LPS led to a decrease only in the levels of corticosterone, and an increase only in the levels of S100B, in serum and CSF, respectively. Intranasal treatment with FPS-ZM1 rescued the depressive/anxious-like behavior and the high levels of S100B in the CSF induced by the injection of LPS, failing to reverse the decrease in serum corticosterone, promoted by the model. This work demonstrates that the inhibition of RAGE, through an intranasal treatment with its pharmacological inhibitor, FPS-ZM1, rescues aspects related to neuroinflammation, but fails to modulate systemic inflammatory markers, suggesting that RAGE, in the CNS, may be associated with the development of a systemic inflammation-induced neuroinflammatory condition

Efeitos da administração intranasal de FPS-ZM1 na neuroinflamação e na interação com o Receptor para Produtos Finais de Glicação Avançada em modelo animal de inflamação sistêmica

A neuroinflamação está presente em grande parte das doenças neurodegenerativas, muitas vezes atuando no desenvolvimento e na progressão destas. O Receptor para Produtos Finais de Glicação Avançada (RAGE) é uma proteína da superfamília das imunoglobulinas, capaz de modular a inflamação através da interação com seus ligantes, responsáveis por induzir a ativação de cascatas de sinalização pró-inflamatórias. Assim, elevados níveis de RAGE e de seus ligantes, como a CML, a HMGB1, a HSP70 e a S100B, acabam participando na manutenção e na propagação de quadros inflamatórios. Considerando o papel deste receptor na instauração e na sustentação da neuroinflamação, este trabalho descreve os efeitos da inibição do RAGE através do tratamento intranasal com seu antagonista FPS-ZM1, em um modelo animal de neuroinflamação crônica induzida por uma injeção intraperitoneal aguda de lipopolissacarídeo (LPS). 70 dias após a administração de LPS (2 mg/kg, i.p.), os ratos utilizados no estudo receberam intranasalmente, ao longo de 14 dias, 1,2 mg de FPS-ZM1. Nos dias 88 e 89, os animais foram submetidos ao Teste de Campo Aberto, sendo eutanasiados no dia 90 após a injeção i.p. do composto. Amostras de soro e de líquido cefalorraquidiano (CSF) foram coletadas: (i) para análise dos níveis de RAGE e de seus ligantes e (ii) para a investigação de perfis inflamatórios e oxidativos. De todos os analitos investigados, 90 dias após sua administração, o LPS provoca uma diminuição apenas dos níveis de corticosterona, e um aumento somente dos níveis de S100B, no soro e no CSF, respectivamente. O tratamento intranasal com FPS-ZM1 resgata o comportamento do tipo-depressivo/ansioso e os elevados níveis de S100B no CSF induzidos pela injeção de LPS, falhando em reverter a diminuição dos níveis de corticosterona no soro provocada pelo modelo. Este trabalho mostra que a inibição de RAGE, através do tratamento intranasal com seu inibidor farmacológico, FPS-ZM1, resgata características relacionadas à neuroinflamação; porém, não altera parâmetros relativos a quadros inflamatórios sistêmicos, sugerindo que o RAGE, a nível de SNC, possa estar associado ao desenvolvimento de estados neuroinflamatórios induzidos por condições de inflamação sistêmica.Neuroinflammation is a condition present in most neurodegenerative diseases, and it many times acts in both their development and progression. The Receptor for Advanced Glycation End Products (RAGE) is a protein of the immunoglobulin superfamily, capable of regulating inflammation through interaction with its ligands, which are responsible for inducing the activation of intracellular pro-inflammatory signaling cascades. Thus, high levels of RAGE and its ligands, such as CML, HMGB1, HSP70 and S100B, end up being accountable for the unfolding and maintenance of inflammatory conditions. Considering the role of this receptor in the establishment and upkeep of neuroinflammation, this study describes the effects of RAGE inhibition through an intranasal treatment with its antagonist FPS-ZM1, in an animal model of chronic neuroinflammation induced by an acute intraperitoneal injection of lipopolysaccharide (LPS). 70 days after LPS administration (2 mg / kg, i.p.), the rats used in the study received intranasally, over 14 days, 1.2 mg of FPS-ZM1. On days 88 and 89, the animals were submitted to the Open Field Test, being euthanized on day 90 after intraperitoneal injection of the compound. Serum and cerebrospinal fluid (CSF) samples were collected: (i) for the analysis of RAGE and their ligands levels, and (ii) for the study of the inflammatory and the oxidative status. Of all the analytes investigated, 90 days after its administration, LPS led to a decrease only in the levels of corticosterone, and an increase only in the levels of S100B, in serum and CSF, respectively. Intranasal treatment with FPS-ZM1 rescued the depressive/anxious-like behavior and the high levels of S100B in the CSF induced by the injection of LPS, failing to reverse the decrease in serum corticosterone, promoted by the model. This work demonstrates that the inhibition of RAGE, through an intranasal treatment with its pharmacological inhibitor, FPS-ZM1, rescues aspects related to neuroinflammation, but fails to modulate systemic inflammatory markers, suggesting that RAGE, in the CNS, may be associated with the development of a systemic inflammation-induced neuroinflammatory condition

Systemic Inflammation Changes the Site of RAGE Expression from Endothelial Cells to Neurons in Different Brain Areas

The receptor for advanced glycation endproducts (RAGE) is a transmembrane, immunoglobulin-like receptor that interacts with a broad repertoire of extracellular ligands. RAGE belongs to a family of cell adhesion molecules and is considered a key receptor in the inflammation axis and a potential contributor to the neurodegeneration. The present study aimed to investigate the content and cell localization of RAGE in the brain of Wistar rats subjected to systemic inflammation induced by a single dose of lipopolysaccharide (LPS, 5 mg/kg, i.p.). Fifteen days after LPS administration, the content of RAGE was analyzed in the prefrontal cortex (PFC), hippocampus (HIPP), cerebellum (CB), and substantia nigra (SN) were investigated. RAGE levels increased in all structures, except HIPP; however, immunohistochemistry analysis demonstrated that the cell site of RAGE expression changed from blood vessel-like structures to neuronal cells in all brain areas. Besides, the highest level of RAGE expression was found in SN. Immunofluorescence analysis in SN confirmed that RAGE expression was mainly co-localized in endothelial cells (RAGE/PECAM-1 co-staining) in untreated animals, while LPS-treated animals had RAGE expression predominantly in dopaminergic neurons (RAGE/TH co-staining). Decreased TH levels, as well as increased pro-inflammatory markers (TNF-α, IL-1β, Iba-1, GFAP, and phosphorylated ERK1/2) in SN, occurred concomitantly to RAGE stimulation in the same site. These results suggest a role for RAGE in the establishment of a neuroinflammation-neurodegeneration axis that develops as a long-term response to systemic inflammation by LPS

Oral administration of carvacrol/β-cyclodextrin complex protects against 6-hydroxydopamine-induced dopaminergic denervation

Carvacrol (CARV) presents valuable biological properties such as anti-inflammatory and antioxidant activities. However, pharmacological uses of CARV are largely limited due to disadvantages related to solubility, bioavailability, preparation and storage processes. The complexation of monoterpenes with β-cyclodextrin (β-CD) increases their stability, solubility and oral bioavailability. Here, the protective effect of oral treatment with CARV/β-CD complex (25 μg/kg/day) against dopaminergic (DA) denervation induced by unilateral intranigral injection of 6-hydroxydopamine (6-OHDA - 10 μg per rat) was analyzed, in order to evaluate a putative application in the development of neuroprotective therapies for Parkinson's disease (PD). Pretreatment with CARV/β-CD for 15 days prevented the loss of DA neurons induced by 6-OHDA in adult Wistar rats. This effect may occur through CARV anti-inflammatory and antioxidant properties, as the pretreatment with CARV/β-CD inhibited the release of IL-1β and TNF-α; besides, CARV prevented the increase of mitochondrial superoxide production induced by 6-OHDA in cultured SH-SY5Y cells. Importantly, hepatotoxicity or alterations in blood cell profile were not observed with oral administration of CARV/β-CD. Therefore, this study showed a potential pharmacological application of CARV/β-CD in PD using a non-invasive route of drug delivery, i.e., oral administration

Intranasal HSP70 administration protects against dopaminergic denervation and modulates neuroinflammatory response in the 6-OHDA rat model

HSP70 is one of the main molecular chaperones involved in the cellular stress response. Besides its chaperone action, HSP70 also modulates the immune response. Increased susceptibility to toxic insults in intra- and extracellular environments has been associated with insufficient amounts of inducible HSP70 in adult neurons. On the other hand, exogenous HSP70 administration has demonstrated neuroprotective effects in experimental models of age-related disorders. In this regard, this study investigated the effects of exogenous HSP70 in an animal model of dopaminergic denervation of the nigrostriatal axis. After unilateral intrastriatal injection with 6-hydroxydopamine (6-OHDA), the animals received purified recombinant HSP70 through intranasal administration (2 μg/rat/day) for 15 days. Our results indicate a neuroprotective effect of intranasal HSP70 against dopaminergic denervation induced by 6-OHDA. Exogenous HSP70 improved motor impairment and reduced the loss of dopaminergic neurons caused by 6-OHDA. Moreover, HSP70 modulated neuroinflammatory response in the substantia nigra, an important event in Parkinson’s disease pathogenesis. Specifically, HSP70 treatment reduced microglial activation and astrogliosis induced by 6-OHDA, as well as IL-1β mRNA expression in this region. Also, recombinant HSP70 increased the protein content of HSP70 in the substantia nigra of rats that received 6-OHDA. These data suggest the neuroprotection of HSP70 against dopaminergic neurons damage after cellular stress. Finally, our results indicate that HSP70 neuroprotective action against 6-OHDA toxicity is related to inflammatory response modulation

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta