Cerebrospinal fluid levels of sortilin-1, lipocalin-2, autotaxin, decorin and interleukin-33 in patients with idiopathic intracranial hypertension / Níveis de sortilina-1, lipocalina-2, autotaxina, decorina e interleucina-33 no líquido cefalorraquidiano em pacientes com hipertensão intracraniana idiopática

Abstract Background Idiopathic intracranial hypertension (IIH) is characterized by increased cerebrospinal fluid (CSF) pressure of unknown cause. It has been suggested that the inflammatory process plays a role in the pathophysiology of the disease. Sortilin-1, lipocalin-2, autotaxin, decorin, and interleukin-33 (IL-33) are among the factors involved in inflammatory processes. Objective To investigate the CSF levels of sortilin-1, lipocalin-2, autotaxin, decorin, and IL-33 in patients with IIH. Methods A total of 24 IIH patients and 21 healthy controls were included in the study. Demographic characteristics of the patients and of the control group as well as CSF pressures were evaluated. Sortilin-1, lipocalin-2, autotaxin, decorin and IL-33 levels in the CSF were measured. Results The CSF levels lipocalin-2, sortilin-1, autotaxin, IL-33 and CSF pressure were significantly higher in the patients group compared with the control group (p < 0.001). Decorin levels were reduced in patients (p < 0.05). There was no correlation between the autotaxin and IL-33 levels and age, gender, CSF pressure, and body mass index. The results of our study showed that inflammatory activation plays an important role in the development of the pathophysiology of IIH. In addition, the fact that the markers used in our study have never been studied in the etiopathogenesis of IIH is important in explaining the molecular mechanism of this disease. Conclusion Studies are needed to evaluate the role of these cytokines in the pathophysiology of the disease. It is necessary to evaluate the effects of these molecules on this process.

Resumo Antecedentes A hipertensão intracraniana idiopática (HII) é caracterizada pelo aumento da pressão do líquido cefalorraquidiano (LCR) de causa desconhecida. Tem sido sugerido que o processo inflamatório desempenha um papel na fisiopatologia da doença. Sortilina-1, lipocalina-2, autotaxina, decorina e interleucina-33 (IL-33) estão entre os fatores envolvidos nos processos inflamatórios. Objetivo Investigar os níveis de sortilina-1, lipocalina-2, autotaxina, decorina e IL-33 no LCR de pacientes com HII. Métodos Um total de 24 pacientes com HII e 21 controles saudáveis foram incluídos no estudo. Foram avaliadas as características demográficas dos pacientes e do grupo controle, bem como as pressões liquóricas. Os níveis de sortilina-1, lipocalina-2, autotaxina, decorina e IL-33 no LCR foram medidos. Resultados Os níveis no líquido cefalorraquidiano lipocalina-2, sortilina-1, autotaxina, IL-33 e pressão liquórica foram significativamente maiores no grupo de pacientes em comparação com o grupo controle (p < 0,001). Os níveis de decorina foram reduzidos nos pacientes (p < 0,05). Não houve correlação entre os níveis de autotaxina e IL-33 e idade, sexo, pressão liquórica e índice de massa corporal. Os resultados do nosso estudo mostraram que a ativação inflamatória desempenha um papel importante no desenvolvimento da fisiopatologia da HII. Além disso, o fato de os marcadores utilizados em nosso estudo nunca terem sido estudados na etiopatogenia da HII é importante para explicar o mecanismo molecular dessa doença. Conclusão Estudos são necessários para avaliar o papel dessas citocinas na fisiopatologia da doença. É necessário avaliar os efeitos dessas moléculas nesse processo

SORL1 Polymorphisms in Mexican Patients with Alzheimer's Disease.

The present study evaluated the risk effect of 12 Single Nucleotide Polymorphisms in the SORL1 gene in the Mexican population using Late-Onset Alzheimer's Disease (LOAD) and control subjects. Considering APOE as the strongest genetic risk factor for LOAD, we conducted interaction analyses between single nucleotide polymorphisms (SNPs) and the APOE genotype. METHODS: Patients were interviewed during their scheduled visits at neurologic and geriatric clinics from different institutions. The LOAD diagnosis included neurological, geriatric, and psychiatric examinations, as well as the medical history and neuroimaging. Polymorphisms in SORL1 were genotyped by real-time PCR in 156 subjects with LOAD and 221 controls. APOE genotype was determined in each study subject. Allelic, genotypic, and haplotypic frequencies were analyzed; an ancestry analysis was also performed. RESULTS: The A/A genotype in rs1784933 might be associated with an increased LOAD risk. Two blocks with high degree linkage disequilibrium (LD) were identified. The first block composed by the genetic variants rs668387, rs689021 and rs641120 showed a positive interaction (mainly the rs689021) with rs1784933 polymorphism. Moreover, we found a significant association between the APOE ε4 allele carriers and the variant rs2070045 located in the second LD block. CONCLUSION: The rs1784933 polymorphism is associated with LOAD in Mexican patients. In addition, the presence of APOE ε4 allele and SORL1 variants could represent a genetic interaction effect that favors LOAD risk in the Mexican population. SNPs have been proposed as genetic markers associated with the development of LOAD that can support the clinical diagnosis. Future molecular studies could help understand sporadic Alzheimer's Disease (AD) among the Mexican population, where currently there is a sub-estimate number in terms of disease frequency and incidence.

Most rotavirus strains require the cation-independent mannose-6-phosphate receptor, sortilin-1, and cathepsins to enter cells.

Cathepsins, endosomal acid proteases, are transported from the trans-Golgi network to late endosomes by the mannose-6-phosphate receptor (M6PR). We have previously demonstrated that some rotavirus strains, like UK, Wa, WI61, DS-1, and YM, require the cation-dependent (CD-) M6PR and cathepsins to enter from late endosomes to the cytoplasm in MA104 cells, while other strains, like the simian strain RRV, which enter cells from maturing endosomes, do not. However, the role of other trans-Golgi network-late endosome transporters, such as the cation-independent (CI-) M6PR and sortillin-1, has not been evaluated. In this work, we found that several rotavirus strains that require the CD-M6PR for cell entry are also dependent on CI-M6PR and sortilin-1. Furthermore, we showed that the infectivity of all these rotavirus strains also requires cathepsins to enter not only MA104 cells, but also human intestinal Caco-2 cells. This study identifies sortilin-1 as a novel cell factor necessary for the infectivity of a virus; in addition, our results strongly suggest that cathepsins could be common cell factors needed for the infectivity of most rotavirus strains.

ProNGF derived from rat sciatic nerves downregulates neurite elongation and axon specification in PC12 cells.

Several reports have shown that a sciatic nerve conditioned media (CM) causes neuronal-like differentiation in PC12 cells. This differentiation is featured by neurite outgrowth, which are exclusively dendrites, without axon or sodium current induction. In previous studies, our group reported that the CM supplemented with a generic inhibitor for tyrosine kinase receptors (k252a) enhanced the CM-induced morphological differentiation upregulating neurite outgrowth, axonal formation and sodium current elicitation. Sodium currents were also induced by depletion of endogenous precursor of nerve growth factorr (proNGF) from the CM (pNGFd-CM). Given that sodium currents, neurite outgrowth and axon specification are important features of neuronal differentiation, in the current manuscript, first we investigated if proNGF was hindering the full PC12 cell neuronal-like differentiation. Second, we studied the effects of exogenous wild type (pNGFwt) and mutated (pNGFmut) proNGF isoforms over sodium currents and whether or not their addition to the pNGFd-CM would prevent sodium current elicitation. Third, we investigated if proNGF was exerting its negative regulation through the sortilin receptor, and for this, the proNGF action was blocked with neurotensin (NT), a factor known to compete with proNGF for sortilin. Thereby, here we show that pNGFd-CM enhanced cell differentiation, cell proportion with long neurites, total neurite length, induced axonal formation and sodium current elicitation. Interestingly, treatment of PC12 cells with wild type or mutated proNGF isoforms elicited sodium currents. Supplementing pNGFd-CM with pNGFmut reduced 35% the sodium currents. On the other hand, pNGFd-CM+pNGFwt induced larger sodium currents than pNGFd-CM. Finally, treatments with CM supplemented with NT showed that sortilin was mediating proNGF negative regulation, since its blocking induced similar effects than the pNGFd-CM treatment. Altogether, our results suggest that proNGF within the CM, is one of the main inhibitors of full neuronal differentiation, acting through sortilin receptor.