Extracellular Vesicles: The Next Generation of Biomarkers and Treatment for Central Nervous System Diseases.

It has been widely established that the characterization of extracellular vesicles (EVs), particularly small EVs (sEVs), shed by different cell types into biofluids, helps to identify biomarkers and therapeutic targets in neurological and neurodegenerative diseases. Recent studies are also exploring the efficacy of mesenchymal stem cell-derived extracellular vesicles naturally enriched with therapeutic microRNAs and proteins for treating various diseases. In addition, EVs released by various neural cells play a crucial function in the modulation of signal transmission in the brain in physiological conditions. However, in pathological conditions, such EVs can facilitate the spread of pathological proteins from one brain region to the other. On the other hand, the analysis of EVs in biofluids can identify sensitive biomarkers for diagnosis, prognosis, and disease progression. This review discusses the potential therapeutic use of stem cell-derived EVs in several central nervous system diseases. It lists their differences and similarities and confers various studies exploring EVs as biomarkers. Further advances in EV research in the coming years will likely lead to the routine use of EVs in therapeutic settings.

Motor and cognitive outcomes of neonates with low birth weight in Brazil: a systematic review and meta-analysis.

BACKGROUND: Data on the outcomes of preterm newborns in South American countries are scarce. Given the great effect of low birth weight (LBW) and/or prematurity on children's neurodevelopment, it is extremely necessary to conduct studies on these phenomena in greater depth in more heterogeneous populations such as those ones from countries with limited resources. METHODS: We conducted a comprehensive literature search on databases including PubMed, the Cochrane Library, and Web of Science for articles published in Portuguese and English up to March 2021 involving children born and evaluated in Brazil. The analysis of the risk of bias was adapted from the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and used to evaluate the methodology of the included studies. RESULTS: From the eligible trials, 25 articles were selected for qualitative synthesis, and 5 of those, for quantitative synthesis (meta-analysis). The meta-analyses showed that children born with LBW presented lower scores on motor development when compared with controls (standardized mean difference: -1.15; 95% confidence interval [95%CI]: -1.56--0.73]; I2: 80%) and also scored lower in terms of cognitive development (standardized mean difference: -0.71; 95% CI: -0.99--0.44; I2: 67%). CONCLUSION: The results of the present study reinforce that impaired motor and cognitive functions can be a significant long-term outcome of LBW. The lower the gestational age at delivery, the higher the risk of impairment in those domains. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database under number CRD42019112403.

ANTECEDENTES: Dados sobre desfechos de recém-nascidos prematuros em países da América do Sul são escassos. Dado o grande efeito do baixo peso ao nascer (BPN) e/ou da prematuridade no neurodesenvolvimento das crianças, é extremamente necessária a realização de estudos que investiguem esses fenômenos com maior profundidade em populações mais heterogêneas. MéTODOS: Realizou-se uma busca da literatura em bases de dados, incluindo PubMed, Cochrane Library e Web of Science, por artigos publicados em português e inglês até março de 2021 envolvendo crianças nascidas e avaliadas no Brasil. A análise de risco de viés foi adaptada da declaração de Fortalecimento do Relato de Estudos Observacionais em Epidemiologia (Strengthening the Reporting of Observational Studies in Epidemiology, STROBE), que foi utilizada para avaliar a metodologia dos estudos. RESULTADOS: Dos estudos elegíveis, 25 artigos foram selecionados para síntese qualitativa, e 5 desses 25, para síntese quantitativa (metanálise). As metanálises mostraram que crianças nascidas com BPN apresentaram pontuação menor em desenvolvimento motor quando comparadas aos controles (diferença média padronizada, −1,15; intervalo de confiança de 95% [IC95%]: −1,56­−0,73]; I2: 80%) e pontuação também menor em termos de desenvolvimento cognitivo (diferença média padronizada, −0,71; IC95%: −0,992−0,44; I2: 67%). CONCLUSãO: Os resultados deste estudo reforçam que o comprometimento das funções motoras e cognitivas pode ser um desfecho significativo de longo prazo do BPN. Quanto menor a idade gestacional no momento do parto, maior o risco de prejuízo nesses domínios. O protocolo do estudo foi registrado no banco de dados International Prospective Register of Systematic Reviews (PROSPERO) sob o número CRD42019112403.

Motor and cognitive outcomes of neonates with low birth weight in Brazil: a systematic review and meta-analysis / Desfechos motores e cognitivos de recém-nascidos com baixo peso ao nascer no Brasil: uma revisão sistemática e metanálise

Abstract Background Data on the outcomes of preterm newborns in South American countries are scarce. Given the great effect of low birth weight (LBW) and/or prematurity on children's neurodevelopment, it is extremely necessary to conduct studies on these phenomena in greater depth in more heterogeneous populations such as those ones from countries with limited resources. Methods We conducted a comprehensive literature search on databases including PubMed, the Cochrane Library, and Web of Science for articles published in Portuguese and English up to March 2021 involving children born and evaluated in Brazil. The analysis of the risk of bias was adapted from the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) statement and used to evaluate the methodology of the included studies. Results From the eligible trials, 25 articles were selected for qualitative synthesis, and 5 of those, for quantitative synthesis (meta-analysis). The meta-analyses showed that children born with LBW presented lower scores on motor development when compared with controls (standardized mean difference: -1.15; 95% confidence interval [95%CI]: -1.56--0.73]; I2: 80%) and also scored lower in terms of cognitive development (standardized mean difference: -0.71; 95% CI: -0.99--0.44; I2: 67%). Conclusion The results of the present study reinforce that impaired motor and cognitive functions can be a significant long-term outcome of LBW. The lower the gestational age at delivery, the higher the risk of impairment in those domains. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database under number CRD42019112403.

Resumo Antecedentes Dados sobre desfechos de recém-nascidos prematuros em países da América do Sul são escassos. Dado o grande efeito do baixo peso ao nascer (BPN) e/ou da prematuridade no neurodesenvolvimento das crianças, é extremamente necessária a realização de estudos que investiguem esses fenômenos com maior profundidade em populações mais heterogêneas. Métodos Realizou-se uma busca da literatura em bases de dados, incluindo PubMed, Cochrane Library e Web of Science, por artigos publicados em português e inglês até março de 2021 envolvendo crianças nascidas e avaliadas no Brasil. A análise de risco de viés foi adaptada da declaração de Fortalecimento do Relato de Estudos Observacionais em Epidemiologia (Strengthening the Reporting of Observational Studies in Epidemiology, STROBE), que foi utilizada para avaliar a metodologia dos estudos. Resultados Dos estudos elegíveis, 25 artigos foram selecionados para síntese qualitativa, e 5 desses 25, para síntese quantitativa (metanálise). As metanálises mostraram que crianças nascidas com BPN apresentaram pontuação menor em desenvolvimento motor quando comparadas aos controles (diferença média padronizada, -1,15; intervalo de confiança de 95% [IC95%]: -1,56--0,73]; I2: 80%) e pontuação também menor em termos de desenvolvimento cognitivo (diferença média padronizada, -0,71; IC95%: -0,992-0,44; I2: 67%). Conclusão Os resultados deste estudo reforçam que o comprometimento das funções motoras e cognitivas pode ser um desfecho significativo de longo prazo do BPN. Quanto menor a idade gestacional no momento do parto, maior o risco de prejuízo nesses domínios. O protocolo do estudo foi registrado no banco de dados International Prospective Register of Systematic Reviews (PROSPERO) sob o número CRD42019112403.

Review of neuroimaging findings in congenital Zika virus syndrome and its relation to the time of infection.

BACKGROUND: Many original articles and case series have been published emphasizing the neuroimaging findings of congenital Zika virus (ZIKV) infection. The majority of these studies do not follow a neuroradiological methodology to describe malformations and brain abnormalities resulting from ZIKV infection. The cause-and-effect correlation between the gestational period of maternal infection and the severity of encephalic changes at birth has rarely been reported. A systematic literature review was conducted on the neuroimaging findings in children affected with microcephaly due to ZIKV. METHODS: PubMed, Cochrane Library and Web of Science were searched for full-text articles published up to July 2019. Duplicate entries were removed. Two independent reviewers performed a quality assessment of all the studies included. RESULTS: A total of 2214 publications were identified. Of these 2170 were excluded by analysis of titles and abstracts, resulting in the inclusion of only eight articles. Chi-square and Fisher's exact tests were performed with a 95% confidence interval to verify the statistically significant differences in the neuroradiological findings between the cases of ZIKV infection in the first or second trimester of gestation. The studies published so far have described image abnormalities at random, without utilizing any pre-established neuroradiological criteria, and imaging modalities with different sensitivity and accuracy have been used, which jeopardizes a reliable and adequate statistical analysis. CONCLUSIONS: Neuroimaging abnormalities are much more prevalent and severe when the infection by ZIKV is contracted in the first or second trimester of pregnancy.

Umbilical Mononuclear Cells and Fibroblast Interaction Downregulate the Expression of Cell Cycle Negative Control Genes.

The human umbilical cord blood (HUCB) is an excellent source of adult stem cells, having the benefit of being younger than the bone marrow stem cells. The role of stem cells in the lesion repair mechanism is still being studied. We evaluated the capability of HUCB to interfere into the fibroblast dedifferentiation plasticity through cocultivation. Direct and indirect cocultures were maintained for 24, 48, and 72 hours. Coculture viability was evaluated by MTT assay. The messenger RNA was extracted, and the expression of p16 and p21 genes was estimated by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). The direct or indirect contact did not interfere with fibroblast cell viability. However, these direct and indirect contacts reduced the expression of p16 and p21 genes. A sigmoidal curve was applied to adjust gene expression against time, and a mathematical function was established for gene expression according to cell culture type. These results suggest that the differentiated cells were influenced by immature cells (HUCB) either by the direct contact or by signaling molecules, which alter their behavior and plasticity. Therefore our data may contribute to paracrine effects other than the commonly known to be responsible for the repair of lesions in stem cell therapy.