Alterations in lipid metabolism of spinal cord linked to amyotrophic lateral sclerosis.

Amyotrophic lateral sclerosis (ALS) is characterized by progressive loss of upper and lower motor neurons leading to muscle paralysis and death. While a link between dysregulated lipid metabolism and ALS has been proposed, lipidome alterations involved in disease progression are still understudied. Using a rodent model of ALS overexpressing mutant human Cu/Zn-superoxide dismutase gene (SOD1-G93A), we performed a comparative lipidomic analysis in motor cortex and spinal cord tissues of SOD1-G93A and WT rats at asymptomatic (~70 days) and symptomatic stages (~120 days). Interestingly, lipidome alterations in motor cortex were mostly related to age than ALS. In contrast, drastic changes were observed in spinal cord of SOD1-G93A 120d group, including decreased levels of cardiolipin and a 6-fold increase in several cholesteryl esters linked to polyunsaturated fatty acids. Consistent with previous studies, our findings suggest abnormal mitochondria in motor neurons and lipid droplets accumulation in aberrant astrocytes. Although the mechanism leading to cholesteryl esters accumulation remains to be established, we postulate a hypothetical model based on neuroprotection of polyunsaturated fatty acids into lipid droplets in response to increased oxidative stress. Implicated in the pathology of other neurodegenerative diseases, cholesteryl esters appear as attractive targets for further investigations.

A new function for Prokineticin 2: Recruitment of SVZ-derived neuroblasts to the injured cortex in a mouse model of traumatic brain injury.

Traumatic brain injury is an important cause of global morbidity and mortality. After an initial injury, there is a cascade of cellular and molecular events that ultimately lead to cell death. Therapies aim to both counteract these mechanisms and replenish the lost cell population in order to improve recovery. The adult mammal brain has at least two neurogenic regions that maintain physiological functions: the subgranular zone of the dentate gyrus in the hippocampus, which produces neurons that integrate locally, and the subventricular zone (SVZ) adjacent to the lateral ventricles, which produces neuroblasts that migrate through the rostral migratory stream (RMS) to the olfactory bulbs. Brain injuries, as well as neurodegenerative diseases, induce the SVZ to respond by increasing cell proliferation and migration to the injured areas. Here we report that cells migrate from the SVZ and RMS to the injured cortex after traumatic brain injury in mice, and that the physiological RMS migration is not impaired. We also show that Prokineticin 2 (PROK2), a chemokine important for the olfactory bulb neurogenesis, expressed exclusively by cortical microglia in the cortex as early as 24 h after injury. We then show that administration of a PROK2 receptor antagonist decreases the number of SVZ cells that reach the injured cortex, while injection of recombinant PROK2 into the cortex of uninjured mice attracts SVZ cells. We also demonstrate that cells expressing PROK2 in vitro directionally attract SVZ cells. These data suggest that PROK2 could be utilized in regeneration efforts for the acutely injured mammalian cortex.

CD36 Neuronal Identity in the Olfactory Epithelium.

CD36 scavenger receptor is expressed in a subpopulation of olfactory sensory neurons (OSNs). These neurons express canonical olfactory signaling machinery; however, not all odorant receptors (ORs) are coexpressed with CD36. In situ hybridization (ISH) enables the detection of nucleic acids in tissues, cells, or isolated chromosomes. The development of nonradioactive and stable labeling probes almost 30 years ago, allowed to routinely perform this technique employing different labeling strategies in one experiment. ISH is widely used in the field of neurobiology of the sense of smell, providing valuable neuroanatomical information regarding the molecular organization of the olfactory epithelium (OE). Here we show a method for studying CD36+-OSNs and provide a detailed protocol for chromogenic ISH, one- or two-color fluorescent ISH, which can be combined with immunofluorescence and are suitable for Cd36 mRNA probing simultaneous to other transcripts and/or proteins labeling.

CD36 is expressed in a defined subpopulation of neurons in the olfactory epithelium.

The sensory neurons in the olfactory epithelium (OSNs) are equipped with a large repertoire of olfactory receptors and the associated signal transduction machinery. In addition to the canonical OSNs, which express odorant receptors (ORs), the epithelium contains specialized subpopulations of sensory neurons that can detect specific information from environmental cues and relay it to relevant neuronal circuitries. Here we describe a subpopulation of mature OSNs in the main olfactory epithelium (MOE) which expresses CD36, a multifunctional receptor involved in a series of biological processes, including sensory perception of lipid ligands. The Cd36 expressing neurons coexpress markers of mature OSNs and are dispersed throughout the MOE. Unlike several ORs analyzed in our study, we found frequent coexpression of the OR Olfr287 in these neurons, suggesting that only a specific set of ORs may be coexpressed with CD36 in OSNs. We also show that CD36 is expressed in the cilia of OSNs, indicating a possible role in odorant detection. CD36-deficient mice display no signs of gross changes in the organization of the olfactory epithelium, but show impaired preference for a lipid mixture odor. Our results show that CD36-expressing neurons represent a distinct population of OSNs, which may have specific functions in olfaction.

Gene Expression Control by Glucocorticoid Receptors during Innate Immune Responses.

Glucocorticoids (GCs) are potent anti-inflammatory compounds that have been extensively used in clinical practice for several decades. GC's effects on inflammation are generally mediated through GC receptors (GRs). Signal transduction through these nuclear receptors leads to dramatic changes in gene expression programs in different cell types, typically due to GR binding to DNA or to transcription modulators. During the last decade, the view of GCs as exclusive anti-inflammatory molecules has been challenged. GR negative interference in pro-inflammatory gene expression was a landmark in terms of molecular mechanisms that suppress immune activity. In fact, GR can induce varied inhibitory molecules, including a negative regulator of Toll-like receptors pathway, or subject key transcription factors, such as NF-κB and AP-1, to a repressor mechanism. In contrast, the expression of some acute-phase proteins and other players of innate immunity generally requires GR signaling. Consequently, GRs must operate context-dependent inhibitory, permissive, or stimulatory effects on host defense signaling triggered by pathogens or tissue damage. This review aims to disclose how contradictory or comparable effects on inflammatory gene expression can depend on pharmacological approach (including selective GC receptor modulators; SEGRMs), cell culture, animal treatment, or transgenic strategies used as models. Although the current view of GR-signaling integrated many advances in the field, some answers to important questions remain elusive.

Expression of Tyrosine Hydroxylase is Negatively Regulated Via Prion Protein.

Cellular prion protein (PrP(C)) is a glycoprotein of the plasma membrane that plays pleiotropic functions by interacting with multiple signaling complexes at the cell surface. Recently, a number of studies have reported the involvement of PrP(C) in dopamine metabolism and signaling, including its interactions with tyrosine hydroxylase (TH) and dopamine receptors. However, the outcomes reported by independent studies are still debatable. Therefore in this study, we investigated the effects of PrP(C) on the TH expression during the differentiation of N2a cells with dibutyryl-cAMP, a well-known cAMP analog that activates TH transcription. Upon differentiation, TH was induced with concomitant reduction of PrP(C) at protein level, but not at mRNA level. shRNA-mediated PrP(C) reduction increased the basal level of TH at both mRNA and protein levels without dibutyryl-cAMP treatment. This phenotype was reversed by re-expression of PrP(C). PrP(C) knockdown also potentiated the effect of dibutyryl-cAMP on TH expression. Our findings suggest that PrP(C) has suppressive effects on TH expression. As a consequence, altered PrP(C) functions may affect the regulation of dopamine metabolism and related neurological disorders.

Efeito da sinvastatina em dose imunossupressora sobre as glândulas salivares e linfonodos cervicais de ratos Wistar / Effects of simvastatin at immunosuppressive dose on salivary glands and cervical lymph nodes of Wistar rats

Objetivo: avaliar a ação de dose imunossupressora da sinvastatina, droga utilizada para o controle da hipercolesterolemia, com efeitos pleiotrópicos anti-inflamatórios, imunomoduladores e antioxidantes, sobre a morfologia das glândulas salivares maiores e linfonodos cervicais de ratos Wistar. Materiais e método: foram utilizados 18 ratos Wistar machos divididos em dois grupos, o grupo controle (Co) (n=6) receberam PBS estéril (i.p), os animais tratados (T7 e T21) (n=12) receberam sinvastatina (10mg/kg, i.p). Os animais foram sacrificados após 7 (T7, n=6 ) e 21 (T21, n=6) dias para avaliação da morfologia das glândulas parótida, submandibular, sublingual e linfonodos cervicais, além de análise de hemograma. Resultados: os grupos T7 e T21 apresentaram ácinos em menor quantidade e com menor área comparado ao grupo Co. Os linfonodos apresentaram menor número de centros germinativos por área no grupo T7; o grupo T21 não apresentou diferença em relação ao grupo Co. A análise hematológica demonstrou linfocitose e neutrofilia apenas aos 7 dias. Conclusão: a administração de sinvastatina em dose imunossupressora pode causar alterações tardias nas glândulas salivares e alterações transitórias nos linfonodos cervicais, podendo causar alteração da sua atividade funcional e protetora sobre as estruturas da cavidade oral.

Efeito do treinamento físico no pulmão de ratos submetidos à ingestão alcoólica / Effects of physical training on lungs of rats submitted to alcohol intake

O alcoolismo crônico provoca alterações nos tecidos pulmonares caracterizadas por edema pulmonar e formação de extenso infiltrado inflamatório. O objetivo deste trabalho foi avaliar o efeito do exercício físico sobre as lesões pulmonares provocadas por ingestão crônica de álcool em ratos Wistar. MATERIAL E MÉTODOS: Trinta e dois ratos Wistar machos (261,1 ± 1,3 gramas) receberam aguardente de cana-de-açúcar diluída (30 por cento, v/v, grupo alcoolizado) ou água potável (grupo controle) durante 120 dias. Após este período, cinco animais de cada grupo foram sacrificados. Os demais animais receberam apenas água potável até o final do experimento e foram divididos em quatro grupos: alcoolizados sedentários (AS), controle sedentários (CS), alcoolizados treinados (AT) e controles treinados (CT). Os animais AT e CT foram submetidos a protocolo de natação, aumentando gradativamente o tempo de exercício até 20 minutos por dia, cinco vezes por semana, durante um período total de cinco semanas. Neste mesmo período, os animais AS e CS foram mantidos em sedentarismo. RESULTADOS: Após o período de ingestão alcoólica, os animais do grupo alcoolizado apresentaram redução de peso (P < 0,05) e aumento da massa relativa do pulmão (P < 0,05). O pulmão do grupo alcoolizado apresentou edema pulmonar e extenso infiltrado inflamatório. Os animais dos grupos CS e CT não apresentaram diferenças morfológicas. Os animais do grupo AT apresentaram aumento do quadro de edema pulmonar e do número de macrófagos pigmentados em relação ao grupo AC (P < 0,05). CONCLUSÃO: O exercício físico pode acentuar o processo inflamatório pulmonar quando aplicado em animais com lesão pulmonar inflamatória provocada pelo consumo crônico de álcool.

Chronic alcohol consumption causes alterations in the lung tissues characterized by edema and formation of large inflammatory infiltrate. The purpose of this work was to evaluate the effect of physical exercise on lung injuries caused by chronic alcohol intake in Wistar rats. MATERIAL AND METHODS: Thirty-two male Wistar rats (261.1 ± 1.3 g) received sugarcane distilled alcoholic beverage diluted (30 percent, v/v, alcohol group) or tap water (control group) for 120 days. After this period, five animals of each group were sacrificed. The remaining animals received water and were sorted in four groups: alcoholic and sedentary (AS), control and sedentary (CS), alcoholic and trained (AT) and control and trained (CT). The AT and CT groups were submitted to a swimming exercise protocol with progressive daily increase in the training time until 20 minutes per day, five times per week, for five weeks. For the same period, AS and CS groups were maintained at sedentary state. RESULTS: after the alcoholic intake period, the alcohol group presented decreased (P<0.05) body weight and increased relative lung weight (P<0.05). Lungs of alcoholic group showed characteristics of edema and inflammatory infiltrate. The CS and CT groups did not present morphological changes. AT animals showed increased inflammation and number of hyper pigmented macrophages in relation to CT group. CONCLUSION: exercise can increase lung inflammation when applied in animals with inflammatory injury induced by chronic alcohol consumption.