Disruption of TNF-α signaling improves osteoblastic differentiation of adipose-derived mesenchymal stem cells and bone repair.

Adipose tissue is an attractive source of mesenchymal stem cells (at-MSCs), but their low osteogenic potential limits their use in bone regeneration. Adipose tissue plays a role in pro-inflammatory diseases by releasing cytokines with a catabolic effect on bone, such as tumor necrosis factor-alpha (TNF-α). Thus, we hypothesized that endogenous TNF-α could have a negative effect on at-MSC differentiation into osteoblasts. Short interfering RNAs (siRNAs) targeting TNF-α receptors (siR1, siR2, and si1R/R2) were transfected into at-MSCs, and cell differentiation was assessed by measuring the expression of bone markers, ALP activity, and mineralized matrix. Scrambled was used as Control. Knockout at-MSCs (KOR1/R2) was injected in mice calvaria defects, and bone formation was evaluated by microtomography and histological analysis. Data were compared by Kruskal-Wallis or analysis of variance (5%). The expression of bone markers confirmed that at-MSCs differentiate less than bone marrow MSCs. In silenced cells, the expression of Alp, Runx2, and Opn was generally higher compared to Control. ALP, RUNX2, and OPN were expressed at elevated levels in silenced groups, most notably at-MSCs-siR1/R2. ALP was detected at high levels in at-MSCs-siR1/R2 and in-MSCs-siR1, followed by an increase in mineralized nodules in at-MSCs-siR1/R2. As the morphometric parameters increased, the groups treated with KOR1/R2 exhibited slight bone formation near the edges of the defects. Endogenous TNF-α inhibits osteoblast differentiation and activity in at-MSCs, and its disruption increases bone formation. While opening a path of investigation, that may lead to the development of new treatments for bone regeneration using at-MSC-based therapies.

An Ultra-Low Dose of ∆9-Tetrahydrocannabinol Alleviates Alzheimer's Disease-Related Cognitive Impairments and Modulates TrkB Receptor Expression in a 5XFAD Mouse Model.

Alzheimer's disease (AD) is the most common form of dementia, but there is still no available treatment. Δ9-tetrahydrocannabinol (THC) is emerging as a promising therapeutic agent. Using THC in conventional high doses may have deleterious effects. Therefore, we propose to use an ultra-low dose of THC (ULD-THC). We previously published that a single injection of ULD-THC ameliorated cognitive functioning in several models of brain injuries as well as in naturally aging mice. Here, 5xFAD AD model mice received a single treatment of ULD-THC (0.002 mg/kg) after disease onset and were examined in two separate experiments for cognitive functions, neurotropic, and inflammatory factors in the hippocampus. We show that a single injection of ULD-THC alleviated cognitive impairments in 6- and 12-month-old 5xFAD mice. On the biochemical level, our results indicate an imbalance between the truncated TrkB receptor isoform and the full receptor, with AD mice showing a greater tendency to express the truncated receptor, and ULD-THC improved this imbalance. We also investigated the expression of three AD-related inflammatory markers and found an ameliorating effect of ULD-THC. The current research demonstrates for the first time the beneficial effects of a single ultra-low dose of THC in a mouse model of AD after disease onset.

Imbalance in Sirt1 Alternative Splicing in Response to Chronic Stress during the Adolescence Period in Female Mice.

Stressful unpredictable life events have been implicated in numerous diseases. It is now becoming clear that some life periods are more vulnerable than others. As adolescence is a sensitive period in brain development, the long-term effects of stress during this period could be significant. We investigated the long-term effects of exposure to unpredictable chronic mild stress in adolescent mice on alternative splicing of Sirtuin 1. One-month-old mice were exposed to 4 weeks of UCMS and examined for anxiety and cognition at the age of 2, 4 and 6 months. We found a rise in anxious behavior immediately after the exposure to stress. Notably, there was a long-term impairment of performance in cognitive tasks and an imbalance in Sirtuin 1 and TrkB receptor alternative splicing in the stress-exposed mice compared with controls. To conclude, our results show that exposure to unpredictable chronic mild stress during adolescence affects cognition in adulthood. Understanding pathways affiliated with stress may help minimize the long-term emotional effects of an unpredictable, stressful event.

Histomorphometry of mast cells in the convexity of human intracranial dura mater.

Mast cells, known as pro-inflammatory effector cells, are immunocytes present in the meninges and may be involved in the pathophysiology of migraine. This study aims to evaluate the histomorphometric parameters of mast cells located in the convexity of the human intracranial dura mater. For this, samples of intracranial dura mater from eight human fresh cadavers were collected between 8- and 24-h post-mortem. The whole samples were fixed and, subsequently, two fragments of 1.5 cm² each were cut from four different areas of the dura mater convexity, containing a segment of the middle meningeal artery, totaling 64 fragments. After histological processing, the fragments were submitted to microtomy (5 and 10 µm), stained with toluidine blue (0.1%), or immunohistochemically labeled for tryptase, and analyzed using optical microscopy. The following histomorphometric parameters were evaluated: distance from mast cells to vessels, the density of mast cells, and percentage of mast cells with degranulation. Histomorphometric analyzes showed a higher density of mast cells in the vicinity of blood vessels (arterial and venous), with distances around 0-150 µm. A greater number of mast cells was detected near venous vessels in the periosteal layer (17.0 ± 10.1 cells/mm²) than in the meningeal layer (14.1 ± 7.0 cells/mm²) (p < 0.05). Mast cells from the region close to the superior sagittal sinus were found in greater quantity close to the venous vessels (16.7 ± 10.1 cells/mm²) than to the arterial vessels (11.2 ± 7.5 cells/mm²) (p < 0.05). In short, in the convexity of the human intracranial dura mater, mast cells are located close to blood vessels, with a greater number of cells next to the venous vessels of the periosteal layer and in the proximal region of the superior sagittal sinus.

Description of brachial plexus of sloth (Bradypus variegatus) / Descrição do plexo braquial do bicho-preguiça (Bradypus variegatus)

The species Bradypus variegatus is known as the common sloth, an endemic mammal from neotropical regions, which has been suffering from devastating anthropogenic activities. Our study aimed to describe the brachial plexus of B. variegates, regarding the origin and distribution of nerves, through the sampling of 10 adult females. Analyses were carried out at the Anatomy Section, "Departamento de Morfologia e Fisiologia Animal", "Universidade Federal Rural de Pernambuco", under license no. 034/2015 of the Ethics Committee on the Use of Animals. The results determined that the brachial plexus of the common sloth starts from the fifth cervical spine segment until the second thoracic segment. This area contains the long and suprascapular thoracic nerves, which originate immediately from the medullary segment 5 and 6, respectively, and from the pectoral, subscapular, axillary, radial, musculocutaneous, medial, forearm and ulnar medial cutaneous nerves, arising from a trunk comprised of cervical spine nerves (C) 7, C8, C9, and thoracic (T) 1 and T2. Regarding other wild and domestic animals, different suggestions were observed about the origin of the plexus in B. variegatus, however, the constituent nerves and their innervation areas did not demonstrate any discrepancies.(AU)

A espécie Bradypus variegatus é conhecida como preguiça-comum. Trata-se de um mamífero endêmico de regiões neotropicais que vem sofrendo com a ação antrópica devastadora. Esses Bradipodídeos possuem três dedos nos membros torácicos e pélvicos, são arborícolas consagrados e descem ao solo apenas para excretar e trocar de árvore. O estudo teve como objetivo descrever o plexo braquial de B. variegatus em relação à origem e distribuição dos nervos. Para tal, utilizou-se 10 fêmeas adultas. As análises foram realizadas no Pavilhão de Anatomia do Departamento de Morfologia e Fisiologia Animal da Universidade Federal Rural de Pernambuco, sob a licença nº 034/2015 do Comitê de Ética no Uso de Animais. Os cadáveres foram obtidos após morte natural, fixados em formaldeído a 20%, conservados em solução salina a 30% em tanques e dissecados para a visualização dos nervos destinados a inervar os membros e músculos torácicos. Uma vez feito, constatou-se que o plexo braquial da preguiça-comum se origina do quinto segmento espinal cervical, se estendendo até o segundo segmento torácico. Sendo formado pelos nervos torácico longo e supraescapular, de origem imediatamente do segmento medular 5 e 6, respectivamente, e pelos nervos peitorais, subescapulares, axilar, radial, musculocutâneo, mediano, cutâneo medial do antebraço e ulnar, decorrentes de um tronco formado a partir de nervos espinais cervicais (C) 7, C8, C9, e torácicos (T) 1 e T2. Em comparação a outros animais silvestres e domésticos foram observadas diferentes disposições em relação à origem do plexo de B. variegatus, todavia, os nervos constituintes e suas áreas de inervação não apresentaram discrepâncias.(AU)

Categorias de Aptidão Física Baseadas no VO2max em População Brasileira com Suposto Alto Nível Socioeconômico e sem Cardiopatia Estrutural / VO2max-Based Physical Fitness Categories in a Brazilian Population with Supposed High Socioeconomic Status and without Structural Heart Disease

Resumo Fundamento Os dados mais utilizados como referência de aptidão cardiorrespiratória (ACR) são os de Cooper, que utiliza valores calculados de captação máxima de oxigênio (VO2máx). Objetivo Desenvolver valores de ACR a partir do teste cardiopulmonar de exercício (TCPE) em uma população brasileira com alto nível socioeconômico e livre de cardiopatia estrutural. Os resultados dos testes de VO2max foram comparados aos dados de Cooper e do FRIEND Registry. Métodos Foram utilizados neste estudo dados de TCPE de indivíduos consecutivos entre 1º de janeiro de 2000 e 31 de maio de 2016. Os critérios de inclusão foram: VO2máx pré-definido. Foi construído um gráfico de ACR de acordo com os percentuais do VO2máx: muito ruim (≤20%), ruim (20-40%), regular (40-60%), boa (60-80%), excelente (80-90%), e superior (≥90%). A correlação Kappa foi usada para analisar nossos dados em comparação aos dados dos outros dois bancos de dados. Os testes estatísticos com p<0,005 foram considerados significativos. Resultados A coorte final incluiu 18.186 testes: 12.552 homens, 5.634 mulheres (7 a 84 anos). A resposta mais recorrente foi "boa" (20,2%). Houve diferença média de peso, altura, índice de massa corporal (IMC) e idade no gráfico da ACR. Houve correlação inversa entre VO2máx e idade, peso e IMC. Usando uma regressão linear e essas variáveis, uma equação preditiva foi desenvolvida para o VO2máx. Nossas descobertas diferiram das dos outros bancos de dados. Conclusão Desenvolvemos uma classificação para a ACR e encontramos valores mais altos em todas as faixas de classificação de capacidade funcional, em contraste com os dados de Cooper e do FRIEND Registry. Nossos achados oferecem uma interpretação mais precisa da ACR nessa grande amostra populacional brasileira, quando comparados aos padrões anteriores, com base no VO2máx estimado. (Arq Bras Cardiol. 2020; 115(3):468-477)

Abstract Background The most widely used data for cardiorespiratory fitness (CRF) referrals are from the Cooper Clinic, which uses calculated maximal oxygen uptake (VO2max) values. Objective To develop CRF values from cardiopulmonary exercise testing (CPX) in a Brazilian population with high socioeconomic level and free of structural heart disease. VO2max testing results were compared with the Cooper Clinic and FRIEND Registry data. Methods CPX data from consecutive individuals between January 1,2000, and May 31,2016 were used in this study. Inclusion criteria were: VO2max by a pre-specified definition. We built a CRF chart according to VO2max percentiles: very poor (≤20%), poor (20-40%), fair (40-60%), good (60-80%), excellent (80-90%), and superior (≥90%). Kappa correlation was used to analyze our data in comparison with that of the other two databases. Statistical tests with p<0.005 were considered significant. Results Final cohort included 18,186 tests: 12,552 men, 5,634 women (7-84 years). The most recurrent response was "good" (20.2%). There was a mean difference in weight, height, body mass index (BMI), and age in the CRF chart. An inverse correlation existed between VO2max and age, weight, and BMI. Using a linear regression and these variables, a predictive equation was developed for VO2max. Our findings differed from that of the other databases. Conclusion We developed a classification for CRF and found higher values in all classification ranges of functional capacity in contrast to the Cooper Clinic and FRIEND Registry. Our findings offer a more accurate interpretation of ACR in this large Brazilian population sample when compared to previous standards based on the estimated VO2max. (Arq Bras Cardiol. 2020; 115(3):468-477)

Immobilization of Low-Cost Alternative Vegetable Peroxidase (Raphanus sativus L. peroxidase): Choice of Support/Technique and Characterization.

In the present work the radish (Raphanus sativus L.) was used as the low-cost alternative source of peroxidase. The enzyme was immobilized in different supports: coconut fiber (CF), calcium alginate microspheres (CAMs) and silica SBA-15/albumin hybrid (HB). Physical adsorption (PA) and covalent binding (CB) as immobilization techniques were evaluated. Immobilized biocatalysts (IBs) obtained were physicochemical and morphologically characterized by SEM, FTIR and TGA. Also, optimum pH/temperature and operational stability were determined. For all supports, the immobilization by covalent binding provided the higher immobilization efficiencies-immobilization yield (IY%) of 89.99 ± 0.38% and 77.74 ± 0.42% for HB and CF, respectively. For CAMs the activity recovery (AR) was of 11.83 ± 0.68%. All IBs showed optimum pH at 6.0. Regarding optimum temperature of the biocatalysts, HB-CB and CAM-CB maintained the original optimum temperature of the free enzyme (40 °C). HB-CB showed higher operational stability, maintaining around 65% of the initial activity after four consecutive cycles. SEM, FTIR and TGA results suggest the enzyme presence on the IBs. Radish peroxidase immobilized on HB support by covalent binding is promising in future biotechnological applications.

VO2max-Based Physical Fitness Categories in a Brazilian Population with Supposed High Socioeconomic Status and without Structural Heart Disease. / Categorias de Aptidão Física Baseadas no VO2max em População Brasileira com Suposto Alto Nível Socioeconômico e sem Cardiopatia Estrutural.

BACKGROUND: The most widely used data for cardiorespiratory fitness (CRF) referrals are from the Cooper Clinic, which uses calculated maximal oxygen uptake (VO2max) values. OBJECTIVE: To develop CRF values from cardiopulmonary exercise testing (CPX) in a Brazilian population with high socioeconomic level and free of structural heart disease. VO2max testing results were compared with the Cooper Clinic and FRIEND Registry data. METHODS: CPX data from consecutive individuals between January 1,2000, and May 31,2016 were used in this study. Inclusion criteria were: VO2max by a pre-specified definition. We built a CRF chart according to VO2max percentiles: very poor (≤20%), poor (20-40%), fair (40-60%), good (60-80%), excellent (80-90%), and superior (≥90%). Kappa correlation was used to analyze our data in comparison with that of the other two databases. Statistical tests with p<0.005 were considered significant. RESULTS: Final cohort included 18,186 tests: 12,552 men, 5,634 women (7-84 years). The most recurrent response was "good" (20.2%). There was a mean difference in weight, height, body mass index (BMI), and age in the CRF chart. An inverse correlation existed between VO2max and age, weight, and BMI. Using a linear regression and these variables, a predictive equation was developed for VO2max. Our findings differed from that of the other databases. CONCLUSION: We developed a classification for CRF and found higher values in all classification ranges of functional capacity in contrast to the Cooper Clinic and FRIEND Registry. Our findings offer a more accurate interpretation of ACR in this large Brazilian population sample when compared to previous standards based on the estimated VO2max. (Arq Bras Cardiol. 2020; 115(3):468-477).

FUNDAMENTO: Os dados mais utilizados como referência de aptidão cardiorrespiratória (ACR) são os de Cooper, que utiliza valores calculados de captação máxima de oxigênio (VO2máx). OBJETIVO: Desenvolver valores de ACR a partir do teste cardiopulmonar de exercício (TCPE) em uma população brasileira com alto nível socioeconômico e livre de cardiopatia estrutural. Os resultados dos testes de VO2max foram comparados aos dados de Cooper e do FRIEND Registry. MÉTODOS: Foram utilizados neste estudo dados de TCPE de indivíduos consecutivos entre 1º de janeiro de 2000 e 31 de maio de 2016. Os critérios de inclusão foram: VO2máx pré-definido. Foi construído um gráfico de ACR de acordo com os percentuais do VO2máx: muito ruim (≤20%), ruim (20-40%), regular (40-60%), boa (60-80%), excelente (80-90%), e superior (≥90%). A correlação Kappa foi usada para analisar nossos dados em comparação aos dados dos outros dois bancos de dados. Os testes estatísticos com p<0,005 foram considerados significativos. RESULTADOS: A coorte final incluiu 18.186 testes: 12.552 homens, 5.634 mulheres (7 a 84 anos). A resposta mais recorrente foi "boa" (20,2%). Houve diferença média de peso, altura, índice de massa corporal (IMC) e idade no gráfico da ACR. Houve correlação inversa entre VO2máx e idade, peso e IMC. Usando uma regressão linear e essas variáveis, uma equação preditiva foi desenvolvida para o VO2máx. Nossas descobertas diferiram das dos outros bancos de dados. CONCLUSÃO: Desenvolvemos uma classificação para a ACR e encontramos valores mais altos em todas as faixas de classificação de capacidade funcional, em contraste com os dados de Cooper e do FRIEND Registry. Nossos achados oferecem uma interpretação mais precisa da ACR nessa grande amostra populacional brasileira, quando comparados aos padrões anteriores, com base no VO2máx estimado. (Arq Bras Cardiol. 2020; 115(3):468-477).

Compressão extrínseca de coronária direita anômala corrigida e elegibilidade para atividade física / Corrected anomalous right coronary extrinsic compression and eligibility for physical activity

RELATO DE CASO: FAD, 34 anos, masculino, branco, esportista, corredor de rua (3 a 4x semana, 40 minutos, com guia), deficiente visual, dislipidêmico e epiléptico. Paciente foi submetido à cirurgia de reimplante de artéria coronária direita (ACD) em 2015, com de anomalia ACD com trajeto interarterial em avaliação pré-participação (APP). Evoluiu assintomático, em acompanhamento anual. Em 2017, pioraram os parâmetros eletrocardiográficos, sem sintomas. Encaminhado à cintilografia miocárdica (CM) com estresse físico, sem alteração perfusional. Em janeiro de 2019, após APP, realizou teste ergométrico, com intensificação de infradesnivelamento de segmento ST, abrangendo outras derivações. Diante disso, realizou angiotomografia de coronárias (ATC), que evidenciou kiking em óstio de ACD com sinais de compressão extrínseca e submetido a CM com dobutamina para avaliação de isquemia. REVISÃO: Apesar da baixa incidência na população geral, anomalia coronária é a segunda causa cardiovascular de morte súbita (MS) em atletas jovens, ocorrendo em ± 15 a 20 dos casos. O risco de MS em atletas com origem anômala é 79 vezes maior do que em não atletas. ACD originada no seio coronariano esquerdo é encontrada em 0,03 a 0,17 dos indivíduos submetidos à angiografia. Os sintomas mais frequentes são dor torácica atípica, dispneia, síncope ou pré-síncope relacionada ao exercício, arritmias e disfunção ventricular esquerda, mas na maioria das vezes assintomáticos. ATC e ressonância magnética são considerados padrão ouro para demonstrar a anatomia coronariana e Ecocardiograma transesofágico pode ser útil na avaliação de origem de coronárias, sem avaliação dos seus trajetos. O conhecimento das opções de tratamento e suas complicações são necessários para adequar o protocolo de imagem ao caso clínico. A avaliação da perfusão miocárdica com estresse contribui para estratificação de risco e tomada de decisão para retornar às atividades, porém seu papel na previsão do risco futuro de SCA é incerto. (AU)

The microRNA-23a cluster regulates the developmental HoxA cluster function during osteoblast differentiation.

MicroRNAs (miRs) and Hox transcription factors have decisive roles in postnatal bone formation and homeostasis. In silico analysis identified extensive interaction between HOXA cluster mRNA and microRNAs from the miR-23a cluster. However, Hox regulation by the miR-23a cluster during osteoblast differentiation remains undefined. We examined this regulation in preosteoblasts and in a novel miR-23a cluster knockdown mouse model. Overexpression and knockdown of the miR-23a cluster in preosteoblasts decreased and increased, respectively, the expression of the proteins HOXA5, HOXA10, and HOXA11; these proteins' mRNAs exhibited significant binding with the miR-23a cluster miRNAs, and miRNA 3'-UTR reporter assays confirmed repression. Importantly, during periods correlating with development and differentiation of bone cells, we found an inverse pattern of expression between HoxA factors and members of the miR-23a cluster. HOXA5 and HOXA11 bound to bone-specific promoters, physically interacted with transcription factor RUNX2, and regulated bone-specific genes. Depletion of HOXA5 or HOXA11 in preosteoblasts also decreased cellular differentiation. Additionally, stable overexpression of the miR-23a cluster in osteoblasts decreased the recruitment of HOXA5 and HOXA11 to osteoblast gene promoters, significantly inhibiting histone H3 acetylation. Heterozygous miR-23a cluster knockdown female mice (miR-23a ClWT/ZIP) had significantly increased trabecular bone mass when compared with WT mice. Furthermore, miR-23a cluster knockdown in calvarial osteoblasts of these mice increased the recruitment of HOXA5 and HOXA11, with a substantial enrichment of promoter histone H3 acetylation. Taken together, these findings demonstrate that the miR-23a cluster is required for maintaining stage-specific HoxA factor expression during osteogenesis.

Surto de esporotricose felina na região metropolitana do Recife / Outbreak of feline sporotrichosis in the metropolitan area of Recife

A esporotricose é uma micose subcutânea, causada por um fungo dimórfico do complexo Sporothrix schenckii que acomete várias espécies, especialmente a felina, causando comprometimento local, disseminado ou sistêmico. Objetivou-se relatar a ocorrência de um surto de esporotricose felina na Região Metropolitana do Recife. Foram coletados suabes de úlceras cutâneas de felinos atendidos no Hospital Veterinário da Universidade Federal Rural de Pernambuco e em Clínicas Veterinárias particulares. O diagnóstico foi realizado por meio de exame citológico e cultura fúngica. Dos 115 casos suspeitos, 59 casos foram confirmados, número nunca registrado anteriormente no estado de Pernambuco. Os casos de esporotricose felina registrados têm demonstrado aspectos clínicos e epidemiológicos semelhantes aos ocorridos em outras regiões do país, caracterizando-se como uma doença predominantemente de machos jovens em idade reprodutiva e semi-domiciliados, de difícil tratamento e de rápida disseminação.(AU)

Sporotrichosis is a subcutaneous mycosis caused by a dimorphic fungus from Sporothrix schenckii complex, which affects various species, especially feline, able to cause local, disseminated or systemic impairment. We aimed to report the occurrence of an outbreak of feline sporotrichosis in the Metropolitan Region of Recife. Swabs of skin ulcers in cats treated in the Veterinary Hospital of the Federal Rural University of Pernambuco and in particular veterinary establishments were collected. Diagnosis was made by cytological examination and fungal culture. From 115 suspicious cases, 59 cases were confirmed, unprecedented results in the state of Pernambuco. These registered cases of feline sporotrichosis have demonstrated clinical and epidemiological characteristics similar to those occurring in other regions of the country, characterized as a quick-spreading disease, of difficult treatment, which affects predominantly semi-domiciled young males in reproductive age.(AU)

Microbially-enriched poultry litter-derived biochar for the treatment of acid mine drainage.

Sulfate-reducing bacteria (SRB) and a biochar array were used to reduce sulfate concentrations and the levels of metals in acid mine drainage (AMD) waters. Cow manure SRB-enriched biochar promoted sulfate reductions of 41% compared to original AMD, and 39% compared to other treatments (control, AMD sediment, sludge). Treatments reduced levels of all analyzed metals below Brazilian official standards. DGGE showed a significant relation between SRB-source and SRB-structural community, where cow manure and sludge presented the more cohesive community structure throughout the monitoring (180 days). The study showed that AMD treatment alternatives can be applied and are effective in reducing the contamination of wastewaters.

The effect of collagen coating on titanium with nanotopography on in vitro osteogenesis.

Several studies have shown the positive effects of Ti either with nanotopography or coated with collagen on osteoblast differentiation. Thus, we hypothesized that the association of nanotopography with collagen may increase the in vitro osteogenesis on Ti surface. Ti discs with nanotopography with or without collagen coating were characterized by scanning electron microscopy and atomic force microscopy. Rat calvaria-derived osteoblastic cells were cultured on both Ti surfaces for up to 14 days and the following parameters were evaluated: cell proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization, protein expression of bone sialoprotein (BSP) and osteopontin (OPN), and gene expression of collagen type 1a (Coll1a), runt-related transcription factor 2 (Runx2), osterix (OSX), osteocalcin (OC), Ki67, Survivin, and Bcl2-associated X protein (BAX). Surface characterization evidenced that collagen coating did not alter the nanotopography. Collagen coating increased cell proliferation, ALP activity, extracellular matrix mineralization, and Coll1a, OSX, OC, and BAX gene expression. Also, OPN and BSP proteins were strongly detected in cultures grown on both Ti surfaces. In conclusion, our results showed that the combination of nanotopography with collagen coating stimulates the early, intermediate, and final events of the in vitro osteogenesis and may be considered a potential approach to promote osseointegration of Ti implants. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2783-2788, 2017.

Bioactive glass-based surfaces induce differential gene expression profiling of osteoblasts.

The ability of Biosilicate® with two crystalline phases (BioS-2P) to drive osteoblast differentiation encourages the investigation of the cellular mechanisms involved in this process. Then, the aim of our study was to analyze the large-scale gene expression of osteoblasts grown on BioS-2P compared with Bioglass® 45S5 (45S5). Osteoblasts differentiated from rat bone marrow mesenchymal stem cells were cultured under osteogenic conditions on BioS-2P, 45S5 and polystyrene (control). After 10 days, the expression of 23,794 genes was analyzed using mRNA Sequencing and the data were validated by real-time PCR. The BioS-2P exhibited 5 genes upregulated and 3 downregulated compared with 45S5. Compared with control, BioS-2P upregulated 15 and downregulated 11 genes, while 45S5 upregulated 25 and downregulated 21 genes. Eight genes were commonly upregulated and 4 downregulated by both bioactive glasses. In conclusion, our results demonstrated that bioactive glasses affect the gene expression profiling of osteoblasts. Most of the regulated genes by both BioS-2P and 45S5 are associated with the process of mineralization highlighting their osteostimulation property that is, at least in part, derived from the ability to modulate the intracellular machinery to promote osteoblast genotype expression. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 419-423, 2017.

Participation of MicroRNA-34a and RANKL on bone repair induced by poly(vinylidene-trifluoroethylene)/barium titanate membrane.

The poly(vinylidene-trifluoroethylene)/barium titanate (PVDF) membrane enhances in vitro osteoblast differentiation and in vivo bone repair. Here, we hypothesized that this higher bone repair could be also due to bone resorption inhibition mediated by a microRNA (miR)/RANKL circuit. To test our hypothesis, the large-scale miR expression of bone tissue grown on PVDF and polytetrafluoroethylene (PTFE) membranes was evaluated to identify potential RANKL-targeted miRs modulated by PVDF. The animal model used was rat calvarial defects implanted with either PVDF or PTFE. At 4 and 8 weeks, the bone tissue grown on membranes was submitted to a large-scale analysis of miRs by microarray. The expression of miR-34a and some of its targets, including RANKL, were evaluated by real-time polimerase chain reaction and osteoclast activity was detected by tartrate-resistant acid phosphatase (TRAP) staining. Among more than 250 miRs, twelve, including miR-34a, were simultaneously higher expressed (≥2 fold) at 4 and 8 weeks on PVDF. The higher expression of miR-34a was concomitant with a reduced expression of all its evaluated targets, including RANKL. Additionally, more TRAP-positive cells were observed in bone tissue grown on PTFE compared with PVDF in both time points. In conclusion, our results suggest that the higher bone formation induced by PVDF could be, at least in part, triggered by a miR-34a increase and RANKL decrease, which may inhibit osteoclast differentiation and activity, and bone resorption.

MicroRNA 665 Regulates Dentinogenesis through MicroRNA-Mediated Silencing and Epigenetic Mechanisms.

Studies of proteins involved in microRNA (miRNA) processing, maturation, and silencing have indicated the importance of miRNAs in skeletogenesis, but the specific miRNAs involved in this process are incompletely defined. Here, we identified miRNA 665 (miR-665) as a potential repressor of odontoblast maturation. Studies with cultured cell lines and primary embryonic cells showed that miR-665 represses the expression of early and late odontoblast marker genes and stage-specific proteases involved in dentin maturation. Notably, miR-665 directly targeted Dlx3 mRNA and decreased Dlx3 expression. Furthermore, RNA-induced silencing complex (RISC) immunoprecipitation and biotin-labeled miR-665 pulldown studies identified Kat6a as another potential target of miR-665. KAT6A interacted physically and functionally with RUNX2, activating tissue-specific promoter activity and prompting odontoblast differentiation. Overexpression of miR-665 reduced the recruitment of KAT6A to Dspp and Dmp1 promoters and prevented KAT6A-induced chromatin remodeling, repressing gene transcription. Taken together, our results provide novel molecular evidence that miR-665 functions in an miRNA-epigenetic regulatory network to control dentinogenesis.

Nanotopography directs mesenchymal stem cells to osteoblast lineage through regulation of microRNA-SMAD-BMP-2 circuit.

The aim of this study was to investigate if chemically produced nanotopography on titanium (Ti) surface induces osteoblast differentiation of cultured human bone marrow mesenchymal stem cells (hMSCs) by regulating the expression of microRNAs (miRs). It was demonstrated that Ti with nanotopography induces osteoblast differentiation of hMSCs as evidenced by upregulation of osteoblast specific markers compared with untreated (control) Ti at day 4. At this time-point, miR-sequencing analysis revealed that 20 miRs were upregulated (>twofold) while 20 miRs were downregulated (>threefold) in hMSCs grown on Ti with nanotopography compared with control Ti. Three miRs, namely miR-4448, -4708, and -4773, which were significantly downregulated (>fivefold) by Ti with nanotopography affect osteoblast differentiation of hMSCs. These miRs directly target SMAD1 and SMAD4, both key transducers of the bone morphogenetic protein 2 (BMP-2) osteogenic signal, which were upregulated by Ti with nanotopography. Overexpression of miR-4448, -4708, and 4773 in MC3T3-E1 pre-osteoblasts noticeably inhibited gene and protein expression of SMAD1 and SMAD4 and therefore repressed the gene expression of key bone markers. Additionally, it was observed that the treatment with BMP-2 displayed a higher osteogenic effect on MC3T3-E1 cells grown on Ti with nanotopography compared with control Ti, suggesting that the BMP-2 signaling pathway was more effective on this surface. Taken together, these results indicate that a complex regulatory network involving a miR-SMAD-BMP-2 circuit governs the osteoblast differentiation induced by Ti with nanotopography. J. Cell. Physiol. 229: 1690-1696, 2014. © 2014 Wiley Periodicals, Inc.

The effect of plasma-nitrided titanium surfaces on osteoblastic cell adhesion, proliferation, and differentiation.

In this study, we evaluated the effect of new plasma-nitrided Ti surfaces on the progression of osteoblast cultures, including cell adhesion, proliferation and differentiation. Ti surfaces were treated using two plasma-nitriding protocols, hollow cathode for 3 h (HC 3 h) and 1 h (HC 1 h) and planar for 1 h. Untreated Ti surfaces were used as control. Cells derived from human alveolar and rat calvarial bones were cultured on Ti surfaces for periods of up to 14 days and the following parameters were evaluated: cell morphology, adhesion, spreading and proliferation, alkaline phosphatase (ALP) activity, extracellular matrix mineralization, and gene expression of key osteoblast markers. Plasma-nitriding treatments resulted in Ti surfaces with distinct physicochemical characteristics. The cell adhesion and ALP activity were higher on plasma-nitrided Ti surfaces compared with untreated one, whereas cell proliferation and extracellular matrix mineralization were not affected by the treatments. In addition, the plasma-nitrided Ti surfaces increased the ALP, reduced the osteocalcin and did not affect the Runx2 gene expression. We have shown that HC 3 h and planar Ti surfaces slightly favored the osteoblast differentiation process, and then these surfaces should be considered for further investigation using preclinical models.