Osteoclast-mediated pain and collapse mechanisms in the femoral head necrosis with bone marrow edema / 西安交通大学学报(医学版)

【Objective】 To explore pain and collapse mechanisms in fosteonecrosis of the femoral head (ONFH) with bone marrow edema (BME). 【Methods】 ONFH patients at ARCO Ⅲ stage who underwent total hip arthroplasty in the First Affiliated Hospital of Guangzhou University of Chinese Medicine were enrolled; the femoral head samples, clinical and imaging data were collected. These patients were divided into BME group and non-BME group according to the MR data in one week preoperative. Hematoxylin-eosin and Sirius red staining were performed to observe the morphological changes in bone tissue of femoral head specimens. Western blotting and qPCR were used to semi-quantitatively analyze the expression levels of CTSK, RANKL, and Netrin-1 proteins and mRNA in different regions of the bone tissue. 【Results】 Clinical and imaging data showed that ONFH patients with BME had significantly higher scores of VAS than ONFH patients without BME. Hematoxylin-eosin staining showed that bone structure disorder and a large number of empty bone lacunae were found in the necrotic areas in both groups, but there exited significant granulation tissue in the BME group, and spindle-shaped fibroblastic cells and inflammatory cells aggregated in the repaired region. Sirius red staining revealed the necrotic and sclerotic areas were accumulated with many collagenous fiber in the BME group. The results of Western blotting and qPCR showed that Netrin-1 expressions in the necrotic, sclerotic and health areas in the BME group were higher than those in the non-BME group (P<0.05), while osteoclast related proteins and mRNA expressions of the necrotic and sclerotic areas in the BME group was higher than those in the non-BME group (P<0.05). 【Conclusion】 All these findings indicated that hip pain was positively correlated with femoral head necrosis with BME, hyperactive osteoclasts participated in the femoral head collapse with BME, and the upregulated expression of Netrin-1 mediated the pain mechanism.

Association between serum netrin-1, netrin-4 and risk of the acute coronary syndrome in patients with type 2 diabetes mellitus-A pilot study

The present study was done to assess the diagnostic utility of serum netrin-1 and netrin-4 for recognising the acute coronary syndrome (ACS) in type 2 diabetes mellitus (T2DM) patients. Forty-two T2DM patients with ACS (Cases) and forty-two T2DM patients without ACS (Controls) were compared. Cases had lower serum netrin-1 and netrin-4 levels than controls and were negatively associated with creatinine kinase-total, creatinine kinase-MB, troponin-T and H-FABP. ROC analysis showed that netrin-1 and netrin-4 had good sensitivity and specificity for ACS prediction in T2DM patients. Serum netrin-1 and netrin-4 levels might be considered complementary markers for ACS diagnosis in T2DM patients.

Research progress of Netrin-1 in eye diseases / 国际眼科杂志(Guoji Yanke Zazhi)

@#Netrin-1 is a neuronal axon guidance factor, a soluble protein secreted by the cell floor, and is among the most widely studied members of the Netrins family.Netrin-1 has the diversity of receptors, and its binding to different receptors can activate different biological effects, resulting in multiple functions. Recent studies have revealed that Netrin-1 is closely associated with neural axon guidance, inflammatory responses, neovascularization, apoptosis, and other responses. It can act not only in the central nervous system, but also in many systemic diseases such as those of the respiratory and cardiovascular systems, making it an important target for the treatment of these diseases. In the field of ophthalmology, Netrin-1 is closely associated with optic nerve hypoplasia(ONH), corneal disease, diabetic retinopathy(DR), age-related macular degeneration(ARMD), and retinoblastoma(RB), and has very promising applications in the prevention and treatment of these diseases. In this review, we will explore the association of Netrin-1 with ocular diseases and its role.

Investigation of effect of paclitaxel on netrin 1 and factor 8 in Ehrlich solid tumors / Investigación del efecto del paclitaxel en netrina 1 y factor 8 en tumores sólidos de Ehrlich

SUMMARY: Cancer known as a malignant tumor, is a class of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. The Ehrlich tumor is a mammary adenocarcinoma of mice developed in solid and ascitic forms. This study was aimed to investigate the effects of paclitaxel on Netrin 1 and Factor 8 expression and also in tumor cell proliferation, apoptosis, angiogenesis, and development of tumor in Ehrlich solid tumors treated with paclitaxel. In this study, 26 adult Balb/C male mice were used. 6 of them were used as stock. Ehrlich ascites cells taken from animals in stock were injected subcutaneously from the neck area to all animals. The mice were randomly assigned to two groups of ten rats per group. Paclitaxel treatment group 10 mg/kg were administered to mice intraperitoneally (i.p.) 4,9, and 14th days. 15th day the animals were sacrificed and tumor tissues were taken. Paraffin-embedded solid tumor sections were stained Hematoxylin & Eosin, Masson's Trichrome. Also solid tumor sections were stained immunohistochemically with Netrin1 and Factor 8. Tunel method was applied to determine apoptosis. Paclitaxel applied as a therapeutic Ehrlich solid tumor reduced the volume of tumors in the treatment groups. At the end of the experiments, in the treatment groups' significantly reduced the Netrin 1 expression and microvessel density compared to the group control. Also paclitaxel in the treatment group increased the number of apoptotic cells. We suggest that decreasing the expression of Netrin 1 would be reduced vessel density and increased apoptosis.

RESUMEN: El cáncer, conocido como tumor maligno, es una clase de enfermedad que involucra un crecimiento celular anormal con potencial de invadir o diseminarse a otras partes del cuerpo. El tumor de Ehrlich es un adenocarcinoma mamario de ratones desarrollado en formas sólidas y ascíticas. Este estudio tuvo como objetivo investigar los efectos del paclitaxel en la expresión de Netrin 1 y Factor 8 y también en la proliferación de células tumorales, apoptosis, angiogénesis y desarrollo de tumores sólidos de Ehrlich tratados con paclitaxel. En esta investigación se utilizaron 26 ratones machos Balb / C adultos. Seis de ellos se utilizaron como stock. Se inyectaron por vía subcutánea células de ascitis de Ehrlich tomadas de animales en la zona del cuello. Los ratones se asignaron aleatoriamente a dos grupos de diez ratas por grupo. Se administraron 10 mg/kg del grupo de tratamiento con paclitaxel a ratones por vía intraperitoneal (i.p.) 4, 9 y 14 días. El día 15 se sacrificaron los animales y se extrajeron los tejidos tumorales. Las secciones de tumor sólido incluidas en parafina se tiñeron con hematoxilina y eosina y tricrómico de Masson. También se tiñeron inmunohisto-químicamente secciones de tumor sólido con Netrin1 y Factor 8. Se aplicó el método Tunel para determinar la apoptosis. El paclitaxel aplicado como tumor sólido terapéutico de Ehrlich redujo el volumen de tumores en los grupos de tratamiento. Al final de los experimentos, en los grupos de tratamiento se redujo significativamente la expresión de Netrin 1 y la densidad de microvasos en comparación con el grupo control. Además, el paclitaxel en el grupo tratamiento aumentó el número de células apoptóticas. Sugerimos que la disminución de la expresión de Netrin 1 reduciría la densidad de los vasos y aumentaría la apoptosis.

Advance of Netrin-1 for Protection and Repairment of Injuries after Cerebral Infarction (review) / 中国康复理论与实践

Netrin-1 may protect and repair the damage caused by cerebral infarction, in terms of inhibiting apoptosis and inflammatory, and promoting angiogenesis and axon regeneration, etc. Netrin-1 may associate with the pathogenesis and outcome of cerebral infarction. The application of Netrin-1 in clinic needs more researches.

Urine hepcidin, netrin-1, neutrophil gelatinase-associated lipocalin and C-C motif chemokine ligand 2 levels in multicystic dysplastic kidney / Níveis de hepcidina, netrina-1, lipocalina associada a gelatinase neutrofílica e ligante de quimiocina C-C motif na urina do rim displásico multicístico

ABSTRACT Introduction: Glomerular hyperfiltration may lead to proteinuria and chronic kidney disease in unilateral multicystic dysplastic kidney (MCDK). We aimed to investigate the urine neutrophil-gelatinase-associated lipocalin (NGAL), netrin-1, hepcidin, and C-C motif chemokine ligand-2 (MCP-1/CCL-2) levels in patients with MCDK. Methods: Thirty-two patients and 25 controls were included. The urine hepcidin, netrin-1, NGAL, and MCP-1/CCL-2 levels were determined by ELISA. Results: The patients had higher serum creatinine (Cr) levels, urine albumin, and netrin-1/Cr ratio with lower GFR. There were positive correlations between urine protein/Cr, MCP-1/CCL-2/Cr, and netrin-1 with NGAL (r = 0.397, p = 0.031; r = 0.437, p = 0.041, r = 0.323, p = 0.042, respectively). Urine netrin-1/Cr was positively correlated with MCP-1/CCL-2/Cr (r = 0.356, p = 0.045). There were positive associations between the presence of proteinuria and netrin-1/Cr, MCP-1/CCL-2/Cr, and NGAL/Cr [Odds ratio (OR): 1.423, p = 0.037, OR: 1.553, p = 0.033, OR: 2.112, p = 0.027, respectively)]. ROC curve analysis showed that netrin-1/Cr, MCP-1/CCL-2/Cr, and NGAL/Cr had high predictive values for determining proteinuria p = 0.027, p = 0.041, p = 0.035, respectively). Urine hepcidin/Cr was negatively correlated with tubular phosphorus reabsorption and was positively correlated with urine NGAL/Cr (r = -0.418, p = 0.019; r = 0.682, p = 0.000; respectively). Conclusions: MCP-1/CCL-2 may play a role in the development of proteinuria in MCDK. Netrin-1 may be a protective factor against proteinuria-induced renal injury. Urine hepcidin/Cr may reflect proximal tubule damage in MCDK. Urine NGAL/Cr may be a predictor of tubule damage by proteinuria.

Resumo Introdução: A hiperfiltração glomerular pode causar proteinúria e doença renal crônica no rim displásico multicístico unilateral (RDM). Nosso objetivo foi investigar os níveis de lipocalina associada à gelatinase neutrofílica na urina (NGAL), netrina-1, hepcidina e quimiocina C-C com ligante-2 (MCP-1/CCL-2) em pacientes com RDM. Métodos: Trinta e dois pacientes e 25 controles foram incluídos. Os níveis urinários de hepcidina, netrin-1, NGAL e MCP-1/CCL-2 foram determinados por ELISA. Resultados: Os pacientes apresentaram níveis séricos mais elevados de creatinina (Cr), albumina na urina e relação netrina-1/Cr com menor TFG. Houve correlação positiva entre proteína na urina/Cr, MCP-1/CCL-2/Cr e netrina-1 com NGAL (r = 0,397, p = 0,031; r = 0,437, p = 0,041, r = 0,323, p = 0,042, respectivamente). A netrina-1/Cr na urina foi correlacionada positivamente com MCP-1/CCL-2/Cr (r = 0,356, p = 0,045). Houve associações positivas entre a presença de proteinúria e netrina-1/Cr, MCP-1/CCL-2/Cr e NGAL/Cr [Odds ratio (OR): 1,423, p = 0,037, OR: 1,553, p = 0,033, OR: 2,112, p = 0,027, respectivamente) ]. A análise da curva ROC mostrou que netrina-1/Cr, MCP-1/CCL-2/Cr e NGAL/Cr apresentaram altos valores preditivos para determinar a proteinúria p = 0,027, p = 0,041, p = 0,035, respectivamente). A hepcidina/Cr na urina foi correlacionada negativamente com a reabsorção tubular de fósforo e positivamente com a NGAL/Cr na urina (r = -0,418, p = 0,019; r = 0,682, p = 0,000; respectivamente). Conclusões: MCP-1/CCL-2 pode ter participação no desenvolvimento de proteinúria no RDM. A Netrina-1 pode ser um fator protetor contra lesão renal induzida por proteinúria. Hepcidina/Cr na urina pode refletir danos em túbulos proximais no RDM. O valor de NGAL/Cr urinário pode ser um preditor de danos nos túbulos por proteinúria.

Níveis Elevados de Netrina-1 e IL-1β em Mulheres Idosas com SCA: Pior Prognóstico no Acompanhamento de Dois Anos / High Serum Netrin-1 and IL-1β in Elderly Females with ACS: Worse Prognosis in 2-years Follow-up

Resumo Fundamento Vários marcadores têm sido avaliados quanto a um potencial impacto nas decisões clínicas ou na predição de mortalidade na síndrome coronariana aguda (SCA), incluindo Netrina-1 e IL-1β. Objetivo Examinamos o valor prognóstico de Netrina-1 e IL-1β em pacientes com SCA (2 anos de acompanhamento). Métodos Avaliamos Netrina-1, IL-1β e outros fatores de risco em amostras de soro de 803 pacientes. Curvas de Kaplan-Meier e regressão de Cox foram usadas para análise de óbito por todas as causas, óbito por doenças cardiovasculares (DCV) e desfecho combinado de infarto agudo do miocárdio (IAM) fatal ou novo IAM não fatal, considerando p < 0,05. Resultados Houve 115 óbitos por todas as causas, 78 óbitos por DCV e 67 eventos no desfecho combinado. Níveis de Netrina-1 acima da mediana (> 44,8 pg/mL) foram associados a pior prognóstico (óbito por todas as causas e por DCV) em mulheres idosas, mesmo após o ajuste do modelo (HR: 2,08, p = 0,038 e HR: 2,68, p = 0,036). Níveis de IL-1β acima da mediana (> 13,4 pg/mL) em mulheres idosas foram associados a risco aumentado para todos os desfechos após o ajuste (todas as causas - HR: 2,03, p = 0,031; DCV - HR: 3,01, p = 0,013; desfecho combinado - HR: 3,05, p = 0,029). Para homens, não foram observadas associações entre Netrina-1 ou IL-1β e os desfechos. Conclusão Níveis séricos elevados de Netrina-1 e IL-1β mostraram associação significativa com pior prognóstico em idosas do sexo feminino. Eles podem ser úteis como indicadores prognósticos em SCA. (Arq Bras Cardiol. 2020; 114(3):507-514)

Abstract Background Several markers have been evaluated for a potential impact on clinical decisions or mortality prediction in acute coronary syndrome (ACS), including Netrin-1 and IL-1β that have been associated with cardiovascular disease. Objective Our study examined the prognostic value of Netrin-1 and IL-1β in patients with ACS (2-year follow-up). Methods We evaluate Netrin-1, IL-1β and other risk factors in the serum sample of 803 patients. Kaplan-Meier curves and Cox regression were used for the analysis of all-cause mortality, cardiovascular mortality, and a combined outcome of fatal myocardial infarction (MI) or new non-fatal MI, considering p-value < 0.05. Results There were 115 deaths from all causes, 78 deaths due to cardiovascular causes and 67 events in combined outcomes. Netrin-1 levels above the median (>44.8 pg/mL) were associated with a worse prognosis (all-cause mortality and cardiovascular mortality) in elderly females, even after model adjustment (HR: 2.08, p = 0.038 and HR: 2.68, p = 0.036). IL-1β levels above the median (>13.4 pg/mL) in elderly females were associated with increased risk of all outcomes after adjustment (all-cause mortality - HR: 2.03, p = 0.031; cardiovascular mortality - HR: 3.01, p = 0.013; fatal MI or new non-fatal MI - HR: 3.05, p = 0.029). For males, no associations were observed between Netrin-1 or IL-1β and outcomes. Conclusion High serum levels of Netrin-1 and IL-1β showed significant association with worse prognosis in elderly females. They may be useful as prognostic indicators in ACS. (Arq Bras Cardiol. 2020; 114(3):507-514)

Netrin-1 works with UNC5B to regulate angiogenesis in diabetic kidney disease / 医学前沿

Netrin-1, an axon guidance factor, and its receptor UNC5B play important roles in axonal development and angiogenesis. This study examined netrin-1 and UNC5B expression in kidneys with diabetic kidney disease (DKD) and investigated their roles in angiogenesis. Netrin-1 and UNC5B were upregulated in streptozotocininduced DKD Wistar rats, and their expression was compared with that in healthy controls. However, exogenous netrin-1 in UNC5B-depleted human renal glomerular endothelial cells (HRGECs) inhibited cell migration and tubulogenesis. This effect was likely associated with SRC pathway deactivation. Netrin-1 treatment also eliminated the pro-angiogenic effects of exogenous VEGF-165 on UNC5B-silenced HRGECs. These results indicate that UNC5B antagonizes netrin-1 and that UNC5B upregulation contributes partly to enhancing angiogenesis in DKD. Therefore, introducing exogenous netrin-1 and depleting endogenous UNC5B are potential strategies for reducing the incidence of early angiogenesis and mitigating kidney injury in DKD.

Artesunate relieves subchondral bone osteoclast-mediated osteoarthritis pain / 中国组织工程研究

BACKGROUND: Studies have shown that osteoclasts induce aberrant in growth of sensory nerves into the subchondral bone by secreting netrin-1, resulting in a reduced pain threshold in an osteoarthritis animal model. Therefore, we assume that inhibition of osteoclasts can alleviate sensory nerve-mediated pain symptoms. OBJECTIVE: To investigate whether artesunate inhibits subchondral bone osteoclasts and reduces sensory nerve-mediated pain, providing experimental data for the treatment of osteoarthritis pain using artesunate. METHODS: C57BL/6J male mice were randomly assigned to a sham operation group, a placebo group and an artesunate group, with 10 mice per group. The mice in the sham operation group were only subjected to right knee capsulotomy with no damage to the other structures. Moreover, there was no intervention after operation. In the other two groups, the mice received an anterior cruciate ligament transection of the right knee to establish the osteoarthritis model, followed by treatment with artesunate (artesunate group, 100 mg/kg per day) or equivalent volume of 5% NaHCO3 (placebo group) via intraperitoneal injection. Fourteen days after surgery, the footprint trial was performed, and the levels of tartrate-resistant acid phosphatase 5b (TRAcP5b), cathepsin K and carboxy-terminal telopeptide of type I collagen (CTX-I) in the peripheral blood were detected using ELISA. The knee joint specimens of each group were subjected to Safranin O-Fast Green staining, histological scoring, tartrate-resistant acid phosphatase (TRAP) staining and immunohistochemical staining with netrin-1 and calcitonin gene-related peptide (CGRP). RESULTS AND CONCLUSION: The percentage of ipsilateral contact area of the right hindpaw in the footprint trial was significantly higher in the sham operation group and artesunate group than the placebo group (P 0.05). No significant differences were observed in the serum levels of TRAcP5b, cathepsin K and CTX-I between the groups (P > 0.05). Based on the Safranin O-Fast Green staining, the cartilage histology score was significantly lower in the sham operation group and the artesunate group than the placebo group (P 0.05). TRAP staining indicated that compared with the placebo group, the Trap+ osteoclasts were significantly lower in the sham operation group and the artesunate group (P 0.05). Compared with the placebo group, the netrin-1+ and CGRP+ sensory nerves in the subchondral bone were significantly decreased in the sham operation group and the artesunate group (P 0.05). Our findings from this study indicate that artesunate improves sensory nerve-mediated pain by inhibiting netrin-1 secreted by subchondral bone osteoclasts, and has therapeutic potential to alleviate osteoarthritis pain.

Effect of netrin-1 on high glucose induced injury of renal tubular epithelial cells / 中国病理生理杂志

AIM:To study the effect of netrin-1 on the damage of renal tubular epithelial cells induced by high glucose.METHODS:Human renal tubular epithelial HK-2 cells were treated with high glucose.Real-time PCR and Western blot were used to detect the expression level of netrin-1 in the cells.HK-2 cells were infected with netrin-1-overexpressing lentivirus, and the effect of netrin-1 over-expression on the HK-2 cells treated with high glucose was observed.The apoptosis rate was analyzed by flow cytometry.The protein level of cleaved caspase-3 was determined by Western blot.lactate dehydrogenase (LDH) activity in the culture medium was measured by 2, 4-binitrobenzene hydrazine method.The content of malondialdehyde (MDA) in the culture medium was detected by thiobarbituric acid method.The concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) in the culture medium were measured by ELISA.RE-SULTS:The expression of netrin-1 at mRNA and protein levels in the HK-2 cells after high glucose treatment was significantly lower than that in the control cells (P<0.05).Infection with netrin-1-over-expressing lentivirus up-regulated the expression of netrin-1 in the HK-2 cells treated with high glucose.High glucose promoted the secretion of IL-1βand TNF-α, decreased the levels of LDH and MDA in the cell culture supernatant, and induced apoptosis and activation of caspase-3 in renal tubular epithelial cells (P<0.05).After the HK-2 cells with up-regulation of netrin-1 were induced by high glucose, the IL-1βand TNF-αsecretion, the levels of LDH and MDA in the culture medium, the apoptosis, and the level of activated caspase-3 protein in the cells were all decreased, as compared with the control cells (P<0.05).CONCLU-SION:Up-regulation of netrin-1 expression attenuates oxidative damage and inflammatory injury, and reduces apoptosis induced by high glucose in renal tubular epithelial cells.

Netrin 1 and Alpha-Methyl Acylcoenzim-A Racemase in diagnosis of prostate cancer / Netrina 1 y Alfa Metil-Acil coenzima-A Racemasa para el diagnóstico de cáncer de próstata

Abstract Objectives: To investigate serum and urine levels of Alpha-methylacyl-CoA-racemase (AMACR) and Netrin 1 in patients with and without prostate cancer and to determine whether these markers could be used as alternatives in diagnosis of prostate cancer instead of serum prostate specific antigen (PSA) levels. Methods: One hundred and seventy five patients between 45-75 years to whom transrectal ultrasound guided biopsies were performed for abnormal serum PSA levels or digital rectal examinations were included. The levels of AMACR and Netrin 1 levels of blood and urine samples of 5 mL those were taken prior to biopsies were measured. . Results: The mean age of the patients was 62.7 ±6.4 years. Prostate cancer was detected in 40 patients (22.8%) while 135 of them (77.2%) were diagnosed as benign prostate hyperplasia (BPH). In BPH group, serum and urine levels of AMACR and Netrin 1 were 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1±46 pg/mL and 19.5 ±5.0 pg/mL respectively. The levels of serum and urine levels of AMACR and Netrin 1 were 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL and 20.1 ±5.3 pg/mL respectively in prostate cancer group. There was no statistically significant difference or correlation between these two groups serum and urine AMACR and Netrin 1 results Conclusions: Serum and urine levels of AMACR and Netrin 1 were not found to be alternatives for serum PSA levels in the diagnosis of prostate cancer in this study.

Resumen Objetivos: Investigar los niveles de alfa-metil acilcoenzima-A y Netrina 1 en pacientes con y sin cáncer de próstata y determinar si estos marcadores pueden ser usados como una alternativa en el diagnóstico de cáncer de próstata en lugar del antígeno prostático específico en suero (PSA). Métodos: Fueron incluidos 175 pacientes entre 45-75 años, a quienes se les realizó una biopsia de próstata guiada por ultrasonido por presentar un nivel anormal de PSA en el suero o un tacto rectal. Se tomó una muestra de 5 mL de sangre y orina para medir los niveles de alfa-metil acilcoenzima-A y Netrina 1. Estos niveles se midieron antes del análisis de la biopsia. Resultados: La edad media de los pacientes fue de 62.7±6.4 años. Se detectó cander en 40 pacientes (22.8%), mientras que a 135 de ellos (77.2%) se les diagnóstico una hiperplasia benigna de próstata (HBP). En el grupo HBP los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 13.4 ±16.9 ng/mL; 7.1 ±3.4 ng/mL; 164.1 ±46 pg/mL y 19.5 ±5.0 pg/mL respectivamente. En el grupo con cáncer de próstata los niveles en suero y orina de alfa-metil acilcoenzima-A y Netrina 1 fueron 10.2 ±9.8 ng/mL; 6.8 ±2.5 ng/mL; 159.1 ±44.1 pg/mL y 20.1 ±5.3 pg/mL respectivamente. No hubo una diferencia significativa o una correlación entre los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina al comparar estos dos grupos de pacientes. Conclusiones: Los niveles de alfa-metil acilcoenzima-A y Netrina 1 en suero y orina no son una alternativa para reemplazar el PSA en suero para el diagnóstico de cáncer de próstata.

Roles and mechanisms of netrins in cancer development / 生物工程学报

As secreted protein and membrane-bound proteins, netrins play important roles in biological processes such as neural cell migration, differentiation and apoptosis. Netrins were thought to guide axon outgrowth and central nervous system morphology since they were discovered. Besides, they also participate in physiological processes such as cell adhesion, migration, differentiation, angiogenesis, lymph angiogenesis, and inflammation in non-neural tissues. Recent studies showed that netrins also involved in the regulation of initiation and development of various tumors including colorectal cancer, pancreatic ductal adenocarcinoma. Because of the functional diversity of netrins and the different biological effects of different receptors in tumor tissue, the specific mechanism of their action in tumors remains unclear. Based on current research progress of our group, this review summed up recent research findings on netrins in relation to cancer biology, suggested possible mechanisms, and discussed the implications in cancer research and intervention.

Study of axonal guidance growth cue netrin-1 on nano-materials in nerve regeneration / 中国药理学与毒理学杂志

Nerve regeneration is a major problem in our society after nerve injury.With the development of nanotechnology,some nano-materials,such as carbon nanotubes and graphene with electrical conductivity,have been used to promote neuronfunctional recovery.Some of the nano-materials,however,are neurotoxic and cause neuronal apoptosis.Nerve injury often leads to the disruption of axons,and broken axons cannot form synapse with target neurons,which affects the repair and regeneration of nerves.Netrin-1 is an important cue in neurogenesis,which can guide the growth and migration of axons and synapse formation during neuronal regeneration.However,some growth factors are used to decorate the surface of nanomateriaes to decrease the toxicity in medicine,but the molecular mechanism by which netrin-1 mediates the toxicity of nanomaterials is not clear yet.In this study,we investigated the nano-materials and the function of netrin-1 in neuronal regeneration in recent years.We have proved that netrin-1 can not only guide the growth and migration of axon and synapse formation,but also promote functional recovery of the neurons which are injured by the toxicity of nanomaterials.Our review will provide a theoretical basis for neuronal regeneration by nanomaterials.

Protect role of Netrin-1 in inflammatory response / 中华危重病急救医学

Neuronal guidance factor Netrin-1 has been known to be involved in nervous system development by controlling neuronal migration through both chemoattractive and chemo-repulsive signaling by binding different receptors. Netrin-1 has been shown to play a positively regulatory role during inflammatory process recently. Since the chemorepulsive receptors were found in leukocytes, it is suggest that Netrin-1 played a protective role in tissue through inhibiting leukocyte trafficking and accumulating during inflammatory process in researches. It is demonstrated that Netrin-1 can limit inflammatory response through the involvement of inflammatory cascades, attenuate hypoxia-inducible tissue injury and suppress apoptosis concurrently. It is indicated that Netrin-1 can be a novel target in future through preventing and inhibiting inflammatory diseases in these researches. This review will focus on recent relevant advances and in-depth study to elucidate its mechanism of anti-inflammation.

Expression and significance of netrin-1 and its receptor UNC5C in precocious puberty female rat hypothalamus

OBJECTIVE@#To study expressions of netrin-1 and its receptor UNC5C in female precocious puberty rat hypothalamus, and explore its effect on precocious puberty process.@*METHODS@#Forty female one-week-old SD rats were randomly divided into four groups: experimental group A (precocious puberty early youth), experimental group B (precocious puberty medium youth), group A (normal pre-puberty), group B (normal early youth) with 10 rats in each group. Precocious puberty experimental rats were induced with Danazol and rats in control group were injected with saline. Uterus and ovaries were removed, specimens were weighed, uterus index and ovarian index were calculated, and amount of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were detected from the blood by ELISA. Real-time PCR was used to detect netrin-1 and its receptor UNC5C, as well as hypothalamic gonadotropin-releasing hormone (GnRH) mRNA expression in hypothalamus tissues; and then, a co-immunoprecipitation study of interactions between netrin-1 and its receptor UNC5C was carried out.@*RESULTS@#Relative target gene expression levels of control group A, control group B, experimental group A, and experimental group B (with β -actin as an internal control for normalization) were as follows: Netrin-1: 3.5±0.9, 5.4±0.7, 4.9±1.0, 5.3±0.3; UNC5C: 0.8± 0.04, 1.7±0.2, 1.82±0.23, 1.58±0.4; GnRH: 1.2±0.3, 2.7±0.3, 2.4±0.7, 3.2±0.4.@*CONCLUSIONS@#LH and FSH concentrations, netrin-1 and its receptor expression are increased in precocious puberty animal models.

Netrin-1: The new tumor markers in renal clear cell carcinoma

OBJECTIVE@#To explore the expression of Netrin-1 protein in human renal clear cell carcinoma (RCCC) and the relationships between Netrin-1, pathology and prognosis.@*METHODS@#72 cases of RCCC admitted in our hospital from 2008 June to 2009 June and their adjacent tissues were selected for study. They included 30 cases in stage Ⅰ-Ⅱ, 42 cases in stage Ⅲ-Ⅳ; 9 cases in grade Ⅰ, 9 cases in grade Ⅱ, 40 cases in grade Ⅲ and 14 cases in grade Ⅳ. All cases were followed up for more than 5 years. Survival analysis lines were made by Kaplan-Meier method and the difference between groups was tested by the Log-rank test. The expression of Netrin-1 protein was detected by immunohistochemistry staining and its clinical significance was analyzed.@*RESULTS@#Renal clear cell carcinoma: 51 cases in high expression of Netrin-1 and 21 cases in low expression, normal tissues: 12 cases in high expression of Netrin-1 and 60 cases in low expression, the difference between the two groups is significant (χ(2) = 42.921, P ＜ 0.01). The difference of the expression of Netrin-1in Fuhrman grade and AJCC clinical stage is significant (χ(2) = 8.000, χ(2) = 6.203; P＜0.05). The 5-year survival rate in low protein expression group and in high protein expression group was 79％ (17/21) and 62％ (32/51). The survival curve had different trend, with no significant difference between groups ((χ(2) = 1.360, P = 0.245).@*CONCLUSIONS@#Netrin-1 protein plays an important role in the development of RCCC. It might be a new specific tumor marker of RCCC, and might become a new target in treatment of RCCC.

Expression of netrin-1 in ovarian serous carcinoma and its significance / 临床与实验病理学杂志

Purpose To investigate the expression of Netrin-1 in ovarian serous carcinoma and its c1inicopatho1ogica1 significance. Methods Netrin-1 protein expression was assessed by immunohistochemica1 method in tissue specimens from 20 cases of benign ovari-an serous cystadenomas,13 cases of border1ine ovarian serous neop1asms and 32 cases of ovarian serous carcinomas( OSC). Results The positive proportion of Netrin-1 protein in OSC tissues was significant1y higher than those in border1ine and benign ovarian serous ne-op1asms(P0. 05). Kap1an-Meier ana1ysis showed that the 5-year surviva1 rate of patients with Netrin-1 over-expression was significant1y 1ower than that of patients with 1ower expression( P<0. 05 ). Conclu-sions The high expression of Netrin-1 in OSC tissues indicates that Netrin-1 p1ays an important ro1e in cancer pathogenesis and deve1-opment and it may be a new assistant marker for prognosis of OSC.

Expression and significance of netrin-1 and its receptor UNC5C in precocious puberty female rat hypothalamus

Objective:To study expressions of netrin-1 and its receptor UNC5C in female precocious puberty rat hypothalamus, and explore its effect on precocious puberty process.Methods:Forty female one-week-old SD rats were randomly divided into four groups: experimental group A (precocious puberty early youth), experimental group B (precocious puberty medium youth), group A (normal pre-puberty), group B (normal early youth) with 10 rats in each group. Precocious puberty experimental rats were induced with Danazol and rats in control group were injected with saline. Uterus and ovaries were removed, specimens were weighed, uterus index and ovarian index were calculated, and amount of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) were detected from the blood by ELISA. Real-time PCR was used to detect netrin-1 and its receptor UNC5C, as well as hypothalamic gonadotropin-releasing hormone (GnRH) mRNA expression in hypothalamus tissues; and then, a co-immunoprecipitation study of interactions between netrin-1 and its receptor UNC5C was carried out.Results: Relative target gene expression levels of control group A, control group B, experimental group A, and experimental group B (withβ-actin as an internal control for normalization) were as follows: Netrin-1: 3.5±0.9, 5.4±0.7, 4.9±1.0, 5.3±0.3; UNC5C: 0.8±0.04, 1.7±0.2, 1.82±0.23, 1.58±0.4; GnRH: 1.2±0.3, 2.7±0.3, 2.4±0.7, 3.2±0.4.Conclusions:LH and FSH concentrations, netrin-1 and its receptor expression are increased in precocious puberty animal models.

Netrin-1:the new tumor markers in renal clear cell carcinoma

Objective:To explore the expression of Netrin-1 protein in human renal clear cell carcinoma (RCCC) and the relationships between Netrin-1, pathology and prognosis. Methods:72 cases of RCCC admitted in our hospital from 2008 June to 2009 June and their adjacent tissues were selected for study. They included 30 cases in stage I-II, 42 cases in stageⅢ-IV;9 cases in grade I, 9 cases in grade II, 40 cases in gradeⅢand 14 cases in grade IV. All cases were followed up for more than 5 years. Survival analysis lines were made by Kaplan—Meier method and the difference between groups was tested by the Log-rank test. The expression of Netrin-1 protein was detected by immunohistochemistry staining and its clinical significance was analyzed. Results:Renal clear cell carcinoma:51 cases in high expression of Netrin-1 and 21 cases in low expression, normal tissues: 12 cases in high expression of Netrin-1 and 60 cases in low expression, the difference between the two groups is significant (χ2=42.921, P<0.01). The difference of the expression of Netrin-1in Fuhrman grade and AJCC clinical stage is significant (χ2=8.000,χ2=6.203;P<0.05). The 5-year survival rate in low protein expression group and in high protein expression group was 79%(17/21) and 62%(32/51). The survival curve had different trend, with no significant difference between groups (χ2=1.360, P=0.245). Conclusions: Netrin-1 protein plays an important role in the development of RCCC. It might be a new specific tumor marker of RCCC, and might become a new target in treatment of RCCC.

Correlation analysis of methylation status of UNC5C gene promoter with colorectal cancer UNC5C / 重庆医学

Objective To investigate the correlation between methylation status of UNC 5C gene promoter with colorectal cancer UNC5C .Methods 54 cases of sporadic colorectal cancer and related normal mucosal tissue ,as well as 6 colon cancer cell lines and fiber cell lines(FCL) in the oncology department of the Kailuan General Hospital from February 2010 to March 2013 were selected as the research objects and performed the mRNA and methylation analysis for exploring the correlation between the netrin‐1 receptor UNC5C defects with colorectal cancer disease .Results mRNA of UNC5A and UNC5B was expressed in the detected colorectal cancer cell lines .Except FCL for UNC5C ,all of the cancer cell lines had no mRNA expression .In colorectal cancer tissue , UNC5C methylation was significantly higher than that in the normal mucosa ,the difference was statistically significant (P<0 .05) . The methylation levels of UNC5C gene in the stage Ⅰ to Ⅱ ,and the stage Ⅲ to Ⅳwere significantly higher than non‐methylation levels ,the differences were statistically significant (P<0 .05) .The correlation analysis by the Spearman method showed that the UNC5C defects was positively correlated with colorectal cancer disease (r= 0 .856 ,P< 0 .05) .Conclusion Netrin‐1 receptor UNC5C defect has certain correlation with colorectal cancer disease .