Soro urêmico inibe a expressão in vitro da quimiocina SDF-1: possível impacto da toxicidade urêmica na lesão endotelial

Introdução: A disfunção endotelial é importante na patogênese da doença cardiovascular (DCV) relacionada à doença renal crônica (DRC). Stromal cell-derived factor-1 (SDF-1) é uma quimiocina que mobiliza células endoteliais progenitoras (EPC) e em conjunto com a interleucina-8 (IL-8) podem ser usadas como marcadores de reparo e lesão tecidual. Objetivo: Neste trabalho, foi investigado o efeito do meio urêmico na expressão de SDF-1 e IL-8 in vivo e in vitro. Métodos: A inflamação sistêmica foi avaliada por meio da proteína C-reativa (PCR) e interleucina-6 (IL-6). IL-8 e SDF-1 foram avaliados por ELISA como marcadores de disfunção endotelial e reparo tecidual, respectivamente. Os estudos in vitro foram realizados em células endoteliais umbilicais humanas (HUVEC) expostas ao meio urêmico ou saudável. Resultados: Foram incluídos nesse estudo 26 pacientes em hemodiálise (HD) (17 ± 3 meses em diálise, 52 ± 2 anos, 38% homens e 11% diabéticos). As concentrações séricas de PCR, IL-6, SDF-1 e IL-8 foram 4,9 ± 4,8 mg/ml, 6,7 ± 8,1 pg/ml, 2625,9 ± 1288,6 pg/ml e 128,2 ± 206,2 pg/ml, respectivamente. Houve correlação positiva entre PCR e IL-6 (ρ = 0,57; p < 0,005) e entre SDF-1 e IL-8 (ρ = 0,45; p < 0,05). Os resultados in vitro demonstraram que a expressão de SDF-1 pelas HUVEC após 6 horas de tratamento com meio urêmico é menor comparada ao tratamento com meio saudável (p < 0,05). Após 12 horas de tratamento, ocorreu aumento de IL-8 quando as HUVECs foram expostas ao meio urêmico (p < 0,005). Conclusão: Sugerimos que SDF-1 e IL-8 nos pacientes em HD podem ser usados para mensurar a extensão do dano e consequente ativação vascular na uremia.

Silencing HIF-1α reduces the adhesion and secretion functions of acute leukemia hBMSCs

Hypoxia inducible factor-1α (HIF-1α) is an important transcription factor, which plays a critical role in the formation of solid tumor and its microenviroment. The objective of the present study was to evaluate the expression and function of HIF-1α in human leukemia bone marrow stromal cells (BMSCs) and to identify the downstream targets of HIF-1α. HIF-1α expression was detected at both the RNA and protein levels using real-time PCR and immunohistochemistry, respectively. Vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1α (SDF-1α) were detected in stromal cells by enzyme-linked immunosorbent assay. HIF-1α was blocked by constructing the lentiviral RNAi vector system and infecting the BMSCs. The Jurkat cell/BMSC co-cultured system was constructed by putting the two cells into the same suitable cultured media and conditions. Cell adhesion and secretion functions of stromal cells were evaluated after transfection with the lentiviral RNAi vector of HIF-1α. Increased HIF-1α mRNA and protein was detected in the nucleus of the acute myeloblastic and acute lymphoblastic leukemia compared with normal BMSCs. The lentiviral RANi vector for HIF-1α was successfully constructed and was applied to block the expression of HIF-1α. When HIF-1α of BMSCs was blocked, the expression of VEGF and SDF-1 secreted by stromal cells were decreased. When HIF-1α was blocked, the co-cultured Jurkat cell’s adhesion and migration functions were also decreased. Taken together, these results suggest that HIF-1α acts as an important transcription factor and can significantly affect the secretion and adhesion functions of leukemia BMSCs.

The role of osteoblasts in regulating hematopoietic stem cell activity and tumor metastasis

Bone marrow stromal cells are critical regulators of hematopoiesis. Osteoblasts are part of the stromal cell support system in bone marrow and may be derived from a common precursor. Several studies suggested that osteoblasts regulate hematopoiesis, yet the entire mechanism is not understood. It is clear, however, that both hematopoietic precursors and osteoblasts interact for the production of osteoclasts and the activation of resorption. We observed that hematopoietic stem cells (HSCs) regulate osteoblastic secretion of various growth factors, and that osteoblasts express some soluble factors exclusively in the presence of HSCs. Osteoblasts and hematopoietic cells are closely associated with each other in the bone marrow, suggesting a reciprocal relationship between them to develop the HSC niche. One critical component regulating the niche is stromal-derived factor-1 (SDF-1) and its receptor CXCR4 which regulates stem cell homing and, as we have recently demonstrated, plays a crucial role in facilitating those tumors which metastasize to bone. Osteoblasts produce abundant amounts of SDF-1 and therefore osteoblasts play an important role in metastasis. These findings are discussed in the context of the role of osteoblasts in marrow function in health and disease.

Adipose tissue-derived stem cells promote pancreatic cancer cell proliferation and invasion

To explore the effects of adipose tissue-derived stem cells (ADSCs) on the proliferation and invasion of pancreatic cancer cells in vitroand the possible mechanism involved, ADSCs were cocultured with pancreatic cancer cells, and a cell counting kit (CCK-8) was used to detect the proliferation of pancreatic cancer cells. ELISA was used to determine the concentration of stromal cell-derived factor-1 (SDF-1) in the supernatants. RT-PCR was performed to detect the expression of the chemokine receptor CXCR4 in pancreatic cancer cells and ADSCs. An in vitro invasion assay was used to measure invasion of pancreatic cancer cells. SDF-1 was detected in the supernatants of ADSCs, but not in pancreatic cancer cells. Higher CXCR4 mRNA levels were detected in the pancreatic cancer cell lines compared with ADSCs (109.3±10.7 and 97.6±7.6 vs 18.3±1.7, respectively; P<0.01). In addition, conditioned medium from ADSCs promoted the proliferation and invasion of pancreatic cancer cells, and AMD3100, a CXCR4 antagonist, significantly downregulated these growth-promoting effects. We conclude that ADSCs can promote the proliferation and invasion of pancreatic cancer cells, which may involve the SDF-1/CXCR4 axis.

Cytokine expression patterns and mesenchymal stem cell karyotypes from the bone marrow microenvironment of patients with myelodysplastic syndromes

The purpose of this study was to explore cytokine expression patterns and cytogenetic abnormalities of mesenchymal stem cells (MSCs) from the bone marrow microenvironment of Chinese patients with myelodysplastic syndromes (MDS). Bone marrow samples were obtained from 30 cases of MDS (MDS group) and 30 healthy donors (control group). The expression pattern of cytokines was detected by customized protein array. The karyotypes of MSCs were analyzed using fluorescence in situ hybridization. Compared with the control group, leukemia inhibitory factor, stem cell factor (SCF), stromal cell-derived factor (SDF-1), bone morphogenetic protein 4, hematopoietic stem cell (HSC) stimulating factor, and transforming growth factor-β in the MDS group were significantly downregulated (P<0.05), while interferon-γ (IFN-γ), tumor necrosis factor-α (TNF-α), and programmed death ligand (B7-H1) were significantly upregulated (P<0.05). For chromosome abnormality analysis, the detection rate of abnormal karyotypes (+8, -8, -20, 20q-, -Y, -7, 5q-) was 30% in the MDS group and 0% in the control group. In conclusion, the up- and downregulated expression of these cytokines might play a key role in the pathogenesis of MDS. Among them, SCF and SDF-1 may play roles in the apoptosis of HSCs in MDS; and IFN-γ, TNF-α, and B7-H1 may be associated with apoptosis of bone marrow cells in MDS. In addition, the abnormal karyotypes might be actively involved in the pathogenesis of MDS. Further studies are required to determine the role of abnormal karyotypes in the occurrence and development of MDS.

Changes in circulating endothelial progenitor cells predict responses of multiple myeloma patients to treatment with bortezomib and dexamethasone

Four cycles of chemotherapy are required to assess responses of multiple myeloma (MM) patients. We investigated whether circulating endothelial progenitor cells (cEPCs) could be a biomarker for predicting patient response in the first cycle of chemotherapy with bortezomib and dexamethasone, so patients might avoid ineffective and costly treatments and reduce exposure to unwanted side effects. We measured cEPCs and stromal cell-derived factor-1α (SDF-1α) in 46 MM patients in the first cycle of treatment with bortezomib and dexamethasone, and investigated clinical relevance based on patient response after four 21-day cycles. The mononuclear cell fraction was analyzed for cEPC by FACS analysis, and SDF-1α was analyzed by ELISA. The study population was divided into 3 groups according to the response to chemotherapy: good responders (n=16), common responders (n=12), and non-responders (n=18). There were no significant differences among these groups at baseline day 1 (P>0.05). cEPC levels decreased slightly at day 21 (8.2±3.3 cEPCs/μL) vs day 1 (8.4±2.9 cEPCs/μL) in good responders (P>0.05). In contrast, cEPC levels increased significantly in the other two groups (P<0.05). SDF-1α changes were closely related to changes in cEPCs. These findings indicate that change in cEPCs at day 21 in the first cycle might be considered a noninvasive biomarker for predicting a later response, and extent of change could help decide whether to continue this costly chemotherapy. cEPCs and the SDF-1α/CXCR4 axis are potential therapeutic targets for improved response and outcomes in MM patients.

Achados otoneurológicos em indivíduos portadores de Diabetes mellitus Tipo 1

Alterações metabólicas, como acontecem no Diabetes mellitus, têm sido mencionadas no desenvolvimento e manutenção das queixas relacionadas ao aparelho vestibular e auditivo. OBJETIVO: Investigar o aparelho vestibular em uma população de indivíduos portadores de Diabetes mellitus Tipo 1. MATERIAL E MÉTODO: Foram avaliados 19 indivíduos, sendo 10 do gênero feminino (52,6%) e 9 do gênero masculino (47,3%), com idades variando de 8 a 25 anos, com diagnóstico médico de Diabetes mellitus tipo 1. Para comparação dos resultados, foi selecionado um grupo controle com outros 19 indivíduos, equiparando-se idade e sexo. O protocolo de avaliação consistiu de anamnese, inspeção otoscópica, avaliação do equilíbrio estático e dinâmico, provas cerebelares e avaliação vectoeletronistagmográfica. DESENHO CIENTÍFICO: Clínico prospectivo. RESULTADOS: Encontrou-se na amostra estudada alteração à vectoeletronistagmografia em 36,84% (n=7) dos indivíduos portadores de Diabetes mellitus Tipo 1, sendo 21,06% (n=4) Síndrome Vestibular Periférica Deficitária e 15,79% (n=3) Síndrome Vestibular Periférica Irritativa. CONCLUSÃO: Concluiu-se que indivíduos com Diabetes mellitus Tipo 1 podem ter seu aparelho vestibular comprometido, mesmo que não apresentem queixas otoneurológicas.

Estudo comparativo entre o aproveitamento escolar de alunos de escola de 1º grau e teste de inibição de emissões otoacústicas transientes

O processamento auditivo é fundamental para a cognição e pode ocasionar deficiência no aprendizado. Os portadores de sua deficiência podem ser habilitados, melhorando o desempenho escolar. É fundamental identificá-los. Dentre os que apresentam baixo custo e facilidade operacional está o exame de emissões otoacústicas. TIPO DE ESTUDO: Clínico e experimental. OBJETIVO: Estudar a relação do aproveitamento escolar com a inibição da emissão otoacústica transiente por estímulo auditivo contralateral. Material e Métodos: Foram avaliados 39 alunos, de sete a doze anos, sendo 19 (48,7%) com bom aproveitamento escolar e 20 (51,3%) com aproveitamento inadequado. Os exames emissão otoacústica com inibição contralateral foram comparados aos resultados de aproveitamento escolar. RESULTADOS: A falha da supressão da otoemissão transiente por estímulo acústico contralateral foi mais encontrada no grupo de crianças com mau aproveitamento escolar. Foi estabelecido um valor de corte de 1.6 dB SPL de redução da otoemissão que caracteriza a criança como pertencente ao grupo com mau aproveitamento com sensibilidade de 65,0%, especificidade de 72,2%, acurácia de 68,4% e valor preditivo positivo de 72,2%. CONCLUSÃO: O teste da falha da inibição contralateral da emissão otoacústica por estímulo auditivo contralateral é preditivo de transtorno do aproveitamento escolar em indivíduos de seis a doze anos de idade.

Amadurecimento e qualidade de ameixas 'Laetitia' tratadas com ácido salicílico e 1-metilciclopropeno

O objetivo deste trabalho foi avaliar o efeito da aplicação de ácido salicílico (AS), isoladamente e em combinação com o 1-metilciclopropeno (1-MCP), sobre o amadurecimento e a qualidade de ameixas 'Laetitia', armazenadas durante 40 dias, sob refrigeração (1 ± 0,1ºC / UR 92 ± 2%). Os tratamentos avaliados foram: controle; 1 mM de AS; 5 mM de AS; 10 mM de AS; e 5 mM de AS + 1-MCP (1 µL L-1). Nos frutos tratados com 10 mM de AS, verificou-se, após a saída da câmara, maior taxa de produção de etileno e incidência de manchas na epiderme, e, após três dias em condição ambiente, maior incidência de degenerescência de polpa. Em frutos tratados com 5 mM de AS, o 1-MCP proporcionou menor produção de etileno e menor incidência de degenerescência de polpa, maiores valores de atributos de textura, além de frutos menos vermelhos. O AS não apresenta efeito sobre a ocorrência de degenerescência da polpa e o amadurecimento de ameixas 'Laetitia', porém, provoca manchas na epiderme, em doses acima de 5 mM. Em frutos tratados com 5 mM de AS, a aplicação de 1-MCP atrasa o amadurecimento e mantém a qualidade da ameixa 'Laetitia'.

Antibodies against Bovine herpesvirus 1 in dairy herds in the state of Espirito Santo, Brasil

Bovine herpesvirus 1 (BoHV-1) causes major losses in worldwide livestock, affecting the respiratory and reproductive tracts of bovine. In the past decades, the number of cases in Brazil has been gradually increasing. Therefore, it is important to assess the distribution of infection in different regions of the country. In the state of Espírito Santo (ES) the BoHV 1 infection rate in dairy cattle herds is unknown. Thus, the aim of this study was to detect neutralizing antibodies against BoHV-1 in serum samples from 1,161 non-vaccinated cows from 59 dairy cattle herds in 23 municipalities of the Metropolitan, North, Northwest and South macro-regions. The identification of seropositive cows was evaluated by the virus neutralization test. The results showed that of all serum samples evaluated 775 (66.75%) had neutralizing antibodies against BoHV-1. Moreover, all herds were found positive; however, the percentage of positive cows varied among regions; 49.06%, 62.15%, 67.21% and 80.04% for the Metropolitan, South, North and Northwest macro-regions, respectively. In this study, the results clearly indicate the dissemination of the viral agent in dairy cattle in the ES state, requiring the monitoring and control of diseases related to BoHV-1 infection.

Postharvest biological control of brown rot in peaches after cold storage preceded by preharvest chemical control 1

ABSTRACT Pathogenic fungi cause skin darkening and peach quality depreciation in post harvest. Therefore, alternative techniques to chemical treatment are necessary in order to reduce risks to human health. The aim of this study was to evaluate the effect of the application of Trichoderma harzianum in association with different fungicides applied before harvest to 'Eldorado' peaches for brown rot control and other quality parameters during storage. The treatments consisted of five preharvest fungicide applications (control, captan, iprodione, iminoctadine and tebuconazole) associated with postharvest application of T. harzianum, after cold storage (with and without application), in three evaluation times (zero, two and four days at 20 °C), resulting in a 5x2x3 factorial design. The application of T. harzianum only brought benefits to the control of brown rot when combined with the fungicide captan, at zero day shelf life. After two days, there was a greater skin darkening in peaches treated with T. harzianum compared with peaches without the treatment, except for peaches treated with the fungicide iprodione and T. harzianum The application of T. harzianum during postharvest showed no benefits for the control of brown rot, however, the association with fungicides reduced the incidence of Rhizopus stolonifer during the shelf life.