Animal models of neuroinflammation secondary to acute insults originated outside the brain.

The term "neuroinflammation" has been widely used to describe a series of acute or chronic conditions that cause inflammation in the central nervous system (CNS). Neurological damage can be a consequence of direct local injury or, secondary, of systemic or even distant inflammatory processes. In this respect, animal models have been developed to better understand the pathophysiology and, possibly, to evaluate more effective methods of treatment for these disorders. Animal models that promote alterations in blood-brain barrier permeability-the activation of microglia or astrocytes, modifications in neuropeptide expression, oxidative stress, increased apoptosis, release of inflammatory mediators, leukocyte infiltration, and brain edema-are likely to involve neuroinflammation and therefore can serve as useful models for human inflammatory CNS injury. This review describes the major animal models of neuroinflammation triggered by systemic or distant inflammatory processes. We will focus on animal models of acute neurologic damage; experimental models that lead to chronic neuroinflammation will not be addressed here.

Pathophysiological aspects of neonatal anoxia and temporal expression of S100ß in different brain regions.

The aim of this study was to investigate the temporal variations of S100ß in the hippocampus, cerebellum and cerebral cortex of neonatal rats (Wistar strain) under anoxic conditions. Real-time PCR and western blotting techniques were used for gene expression and protein analysis. Animals were divided into two groups, a control group and an anoxic group, and further separated at different time points for analysis. After anoxia, S100ß gene expression showed a significant peak in the hippocampus and cerebellum after 2 h, followed by a decline compared to the control group at other time points. The increased gene expression in these regions was also accompanied by an increase in S100ß protein levels in the anoxia group, observable 4 h after injury. In contrast, S100ß mRNA content in the cerebral cortex never exceeded control values at any time point. Similarly, the protein content of S100ß in the cerebral cortex did not show statistically significant differences compared to control animals at any assessment time point. These results suggest that the production profile of S100ß differs by brain region and developmental stage. The observed differences in vulnerability between the hippocampus, cerebellum and cerebral cortex may be attributed to their distinct developmental periods. The hippocampus and cerebellum, which develop earlier than the cerebral cortex, showed more pronounced effects in response to anoxia, which is supported by the gene expression and protein content in this study. This result reveals the brain region-dependent nature of S100ß as a biomarker of brain injury.

Short-Term Effects of Sepsis and the Impact of Aging on the Transcriptional Profile of Different Brain Regions.

Among the clinical manifestations observed in septic patients, sepsis-associated encephalopathy (SAE) is probably the most obscure and poorly explored. It is well established, however, that SAE is more prevalent in aged individuals and related to a worse outcome. In this context, we decided to investigate the acute effects of sepsis, induced by cecal ligation and puncture (CLP), on the cerebral transcriptional profile of young and old rats. The idea was to highlight important signaling pathways possibly implicated in the early stages of SAE. Global gene expression analysis of three different brain regions (hippocampus, cerebellum, and cortex) indicated a relatively small interference of sepsis at the transcriptional level. Cerebellum tissue was the least affected by sepsis in aged rats. The increased expression of S100a8, Upp1, and Mt2a in all three brain regions of young septic rats indicate that these genes may be involved in the first line of response to sepsis in the younger brain. On the other hand, altered expression of a network of genes involved in sensory perception of smell in the cortex of aged rats, but not in young ones, indicates an earlier disruption of cortex function, possibly more sensitive to the systemic inflammation. The expression of S100a8 at the protein level was confirmed in all brain regions, with clear-up regulation in septic aged cortex. Taken together, our results indicate that the transcriptional response of the central nervous system to early sepsis varies between distinct brain regions and that the cortex is affected earlier in aged animals, in line with early neurological manifestations observed in older patients.

"Neuropeptides in the brain defense against distant organ damage".

Delirium, or acute confusional state, is a common manifestation in diseases that originate outside the central nervous system, affecting 30-40% of elderly hospitalized patients and up to 80% of the critically ill, even though it remains unclear if severe systemic inflammation is able or not to induce cellular disturbances and immune activation in the brain. Neuropeptides are pleotropic molecules heterogeneously distributed throughout the brain and possess a wide spectrum of functions, including regulation of the inflammatory response, so we hypothesized that they would be the major alarm system in the brain before overt microglia activation. In order to investigate this hypothesis, we induced acute pancreatitis in 8-10week old rats and collected brain tissue, 12 and 24h following pancreatic injury, to measure neuropeptide and cytokine tissue levels. We found significantly higher levels of ß-endorphin, orexin and oxytocin in the brain of rats submitted to pancreatic injury, when compared to healthy controls. Interestingly, these differences were not associated with increased local cytokine levels, putting in evidence that neuropeptide release occurred independently of microglia activation and may be a pivotal alarm system to initiate neurologic reactions to distant inflammatory non-infectious aggression.

sRAGE in septic shock: a potential biomarker of mortality.

OBJECTIVE: To evaluate and understand the clinical implications of the plasma levels of a soluble isoform of a receptor for advanced glycation end products (sRAGE) in different stages of sepsis. METHODS: Serum sRAGE values in patients who were divided into intensive care unit control, severe sepsis, septic shock and recovery from septic shock groups were statistically analyzed to assess quantity (Kruskal-Wallis), variability (Levine test) and correlation (Spearman rank test) with certain inflammatory mediators (IL-1 α, IL-6, IL-8, IL-10, IP-10, G-CSF, MCP-1, IFN-γ and TNF-α). RESULTS: No changes in sRAGE levels were observed among the groups; however, the septic shock group showed differences in the variability of sRAGE compared to the other groups. A positive correlation with all the inflammatory mediators was reported in the septic shock group. CONCLUSION: sRAGE levels are associated with worse outcomes in patients with septic shock. However, a statistical correlation analysis with other proinflammatory cytokines indicated that the pathways leading to those outcomes are different depending on the sRAGE levels. Future studies to elucidate the pathophysiological mechanisms involving sRAGE in models of sepsis are of great clinical importance for the safe handling of this biomarker.

Increased intestinal production of α-defensins in aged rats with acute pancreatic injury.

Acute pancreatitis is a life-threatening situation, frequently associated with uncontrolled local and systemic inflammation, and aging is associated with a worst prognosis. Antimicrobial peptides are ancient molecules that belong to innate immunity, produced by epithelial and immune cells, and are able to trigger a myriad of effector responses. We have hypothesized that antimicrobial peptides could play an important role during serious pancreatic injury. To investigate our hypothesis, α-defensin-5, α-defensin-7 and CRAMP gene expression levels were measured in the intestinal tissue of old and young rats submitted to chemical pancreatic damage. We found significantly higher levels of α-defensin-5 and α-defensin-7, but not CRAMP, in the samples from old mice. This increase was not associated with a worse systemic inflammatory response. We conclude that α-defensins may have a pivotal role during acute pancreatitis and that the elderly develops a more severe local, but not systemic inflammatory process.

[Analysis of the mRNA expression of the S100ß protein in adipocytes of patients with diabetes mellitus, type 2]. / Análise da expressão do mRNA da proteína S100ß em adipócitos de pacientes com diabetes melito tipo 2.

OBJECTIVE: This study aims to explore the possible relationship between the expression level of S100ß protein mRNA with diabetes mellitus type 2 in adipocytes from patients with this disease in comparison with normoglycemic individuals. MATERIALS AND METHODS: Samples of adipose tissue of eight patients from the coronary section of the Institute Dante Pazzanese of Cardiology (IDPC), four in Group Diabetes and four of Normoglycemic group, were evaluated by RT-PCR real time. RESULTS: An increase around 15 times values, between the threshold cycle (ΔCt), of mRNA expression of S100ß protein in adipocytes of the diabetes group was observed in comparison to the control group (p = 0.015). CONCLUSION: Our results indicate, for the first time, that there is coexistence of increased expression of the S100ß and the type 2 diabetes mellitus gene.

sRAGE no choque séptico: um potencial biomarcador de mortalidade / sRAGE in septic shock: a potential biomarker of mortality

Objetivo: Avaliar e compreender as implicações clínicas dos níveis plasmáticos de uma isoforma solúvel de um receptor de produtos finais de glicação avançada (do inglês receptor for advanced glycation end products - sRAGE) em diferentes fases da sepse. Métodos: Os valores do sRAGE sérico em pacientes divididos nos grupos controle na unidade de terapia intensiva, sepse grave, choque séptico e recuperação de choque séptico foram analisados do ponto de vista estatístico para avaliar a quantidade (Kruskal-Wallis), variabilidade (teste de Levine) e correlação (teste Spearman rank) em relação a certos mediadores inflamatórios (IL-1 α, IL-6, IL-8, IL-10, IP-10, G-CSF, MCP-1, IFN-γ e TNF-α). Resultados: Não se observaram modificações nos níveis de sRAGE entre os grupos; contudo o grupo com choque séptico demonstrou diferenças na variabilidade do sRAGE em comparação aos demais grupos. Foi relatada, no grupo com choque séptico, uma correlação positiva com todos os mediadores inflamatórios. Conclusão: Os níveis de sRAGE se associaram com desfechos piores nos pacientes com choque séptico. Entretanto, uma análise de correlação estatística com outras citocinas pró-inflamatórias indicou que as vias que levam a esses desfechos são diferentes, dependendo dos níveis de sRAGE. ...

Objective: To evaluate and understand the clinical implications of the plasma levels of a soluble isoform of a receptor for advanced glycation end products (sRAGE) in different stages of sepsis. Methods: Serum sRAGE values in patients who were divided into intensive care unit control, severe sepsis, septic shock and recovery from septic shock groups were statistically analyzed to assess quantity (Kruskal-Wallis), variability (Levine test) and correlation (Spearman rank test) with certain inflammatory mediators (IL-1 α, IL-6, IL-8, IL-10, IP-10, G-CSF, MCP-1, IFN-γ and TNF-α). Results: No changes in sRAGE levels were observed among the groups; however, the septic shock group showed differences in the variability of sRAGE compared to the other groups. A positive correlation with all the inflammatory mediators was reported in the septic shock group. Conclusion: sRAGE levels are associated with worse outcomes in patients with septic shock. However, a statistical correlation analysis with other proinflammatory cytokines indicated that the pathways leading to those outcomes are different depending on the sRAGE levels. Future studies to elucidate the pathophysiological mechanisms involving sRAGE in models of sepsis are of great clinical importance for the safe handling of this biomarker. .

Análise da expressão do mRNA da proteína S100β em adipócitos de pacientes com diabetes melito tipo 2 / Analysis of the mRNA expression of the S100β protein in adipocytes of patients with diabetes mellitus, type 2

OBJETIVO: O presente trabalho objetiva compreender a possível relação do nível de expressão gênica do mRNA da proteína S100β em adipócitos com o diabetes melito do tipo 2, pela comparação de dados de portadores dessa doença com os de indivíduos normoglicêmicos. MATERIAIS E MÉTODOS: Foram selecionadas amostras de tecido adiposo de oito pacientes da Seção de Coronárias do Instituto Dante Pazzanese de Cardiologia (IDPC), sendo quatro do grupo diabetes e quatro do grupo de normoglicêmicos. Essas amostras foram submetidas à técnica de RT-PCR em tempo real. RESULTADOS: Por meio do Test-t de Student para os valores de diferença entre os ciclos threshold (ΔCt), observou-se que houve aumento de aproximadamente 15 vezes (p = 0,015) da expressão do mRNA da proteína S100β nos adipócitos dos indivíduos do grupo diabetes quando comparado aos do grupo controle. CONCLUSÃO: Nossos resultados evidenciam, de forma inédita, coexistência entre o aumento da expressão do gene S100β e a patologia do diabetes melito do tipo 2.

OBJECTIVE: This study aims to explore the possible relationship between the expression level of S100β protein mRNA with diabetes mellitus type 2 in adipocytes from patients with this disease in comparison with normoglycemic individuals. MATERIALS AND METHODS: Samples of adipose tissue of eight patients from the coronary section of the Institute Dante Pazzanese of Cardiology (IDPC), four in Group Diabetes and four of Normoglycemic group, were evaluated by RT-PCR real time. RESULTS: An increase around 15 times values, between the threshold cycle (ΔCt), of mRNA expression of S100β protein in adipocytes of the diabetes group was observed in comparison to the control group (p = 0.015). CONCLUSION: Our results indicate, for the first time, that there is coexistence of increased expression of the S100β and the type 2 diabetes mellitus gene.