Mechanism of the Notch1 signaling pathway regulating osteogenic factor influences lumbar disc calcification / 中国骨伤

OBJECTIVE@#To explore the mechanism of the Notch1 signaling pathway in regulating osteogenic factors and influencing lumbar disc calcification.@*METHODS@#Primary annulus fibroblasts from SD rats were isolated and subcultured in vitro. The calcification-inducing factors bone morphogenetic protein-2 (BMP-2) and basic fibroblast growth factor (b-FGF) were added to separate groups to induce calcification, which were referred to as the BMP-2 group and the b-FGF group, respectively. A control group was also set up, which was cultured in normal medium. Subsequently, cell morphology and fluorescence identification, alizarin red staining, ELISA, and quantitative real-time polymerase chain reaction (QRT-PCR) were performed to determine the effect of calcification induction. Cell grouping was performed again, including the control group, the calcification group (adding the inducer BMP-2), the calcification + LPS group(adding the inducer BMP-2 and the Notch1 pathway activator LPS), and the calcification + DAPT group (adding the inducer BMP-2 and the Notch1 pathway inhibitor DAPT). Alizarin red staining and flow cytometry were used to detect cell apoptosis, ELISA was used to detect the content of osteogenic factors, and Western blot was used to detect the expression of BMP-2, b-FGF, and Notch1 proteins.@*RESULTS@#The induction factor screening results showed that the number of mineralized nodules in fibroannulus cells in BMP-2 group and b-FGF group was significantly increased, and the increase was greater in the BMP-2 group Meanwhile, ELISA and Western blot results showed that BMP-2, b-FGF and mRNA expression levels of BMP-2, b-FGF and Notch1 in the induced group were significantly increased (P<0.01). The results of the mechanism of Notch1 signaling pathway affecting lumbar disc calcification showed that compared to calcified group, the number of fibroannulus cell mineralization nodules, apoptosis rate, BMP-2, b-FGF content, the expression levels of BMP-2, b-FGF, and Notch1 proteins were further increased significantly However, the number of mineralization nodules, apoptosis rate, BMP-2 and b-FGF levels, BMP-2, b-FGF and Notch1 protein expression levels were decreased in the calcified +DAPT group (P<0.05 or P<0.01).@*CONCLUSION@#Notch1 signaling pathway promotes lumbar disc calcification through positive regulation of osteogenic factors.

Regulation of Notch1 and Foxp1 by MiR-34a in psoriasis vulgaris / Regulación de Notch1 y Foxp1 por MiR-34ª en psoriasis vulgaris

SUMMARY: This study is to investigate the regulation of Notch1 and Foxp1 by miR-34a in the development of psoriasis vulgaris. RT-PCR was used to compare the levels of miR-34a in the skin lesions of 20 patients with psoriasis vulgaris and 20 normal skin tissues. Immunohistochemistry was used to detect the expression of Notch1 and Foxp1 in 51 patients with psoriasis vulgaris, which were further compared with that in 29 normal control tissues. In addition, in HaCaT cells, we used miR-34a mimics and inhibitors to overexpress and inhibit miR-34a, respectively, and detected the mRNA and protein levels of miR-34a, Notch1, and Foxp1. The level of miR-34a in the skin lesions of patients with psoriasis vulgaris was significantly higher than that in normal skin tissues (t=2.192, P<0.05). The positive rate of Notch1 in the skin lesions of patients with psoriasis vulgaris was 76.47 %, which was significantly higher than that in normal skin tissues (13.79 %) (t=29.215, P<0.01). The positive rate of FOXP1 in the psoriasis vulgaris group was 92.16 %, which was also significantly higher than that in the normal skin group (65.52 %) (t=9.087, P<0.01). In addition, overexpression of miR-34a significantly promoted the expression of Notch1 and Foxp1. However, inhibition of miR-34a significantly reduced Notch1 and Foxp1 levels. miR- 34a is highly expressed in the skin tissues of patients with psoriasis vulgaris, and may participate in the development of psoriasis vulgaris by regulating Notch1 and Foxp1.

RESUMEN: El objetivo de este estudio fue investigar la regulación de Notch1 y Foxp1 por miR-34a en el desarrollo de la psoriasis vulgar. Se utilizó RT-PCR con el fin de comparar los niveles de miR-34a en las lesiones cutáneas de 20 pacientes con psoriasis vulgar y 20 tejidos de piel normales. Se utilizó inmunohistoquímica para detectar la expresión de Notch1 y Foxp1 en 51 pacientes con psoriasis vulgar, que se compararon además con la de 29 tejidos normales control. Además, en las células HaCaT, usamos miméticos e inhibidores de miR-34a para sobreexpresar e inhibir miR-34a, respectivamente, y detectamos los niveles de ARNm y proteína de miR-34a, Notch1 y Foxp1. El nivel de miR- 34a en las lesiones cutáneas de pacientes con psoriasis vulgar fue significativamente mayor que en los tejidos normales de la piel (t=2,192, P<0,05). La tasa de positividad de Notch1 en las lesiones cutáneas de pacientes con psoriasis vulgar fue del 76,47 %, que fue significativamente mayor que la de los tejidos normales de la piel (13,79 %) (t=29,215, P<0,01). La tasa positiva de FOXP1 en el grupo de psoriasis vulgar fue del 92,16 %, que también fue significativamente mayor que la del grupo de piel normal (65,52 %) (t=9,087, P<0,01). Además, la sobreexpresión de miR-34a promovió significativamente la expresión de Notch1 y Foxp1. Sin embargo, la inhibición de miR-34a redujo de manera importante los niveles de Notch1 y Foxp1. miR-34a se expresa en gran medida en los tejidos de la piel en pacientes con psoriasis vulgar y puede participar en el desarrollo de la psoriasis vulgar mediante la regulación de Notch1 y Foxp1.

Effect of Notch1 on extracellular matrix deposition in the renal tubulointerstitium of diabetes / 生理学报

The aim of the present study was to observe the effects of Notch1 and autophagy on extracellular matrix deposition in renal tubulointerstitium of diabetes and to explore the mechanism. The mice were randomly divided into normal control group (db/m mice) and diabetes group (db/db mice). After 12 weeks of feeding, the mice were sacrificed and the corresponding biochemical indexes were measured. Rat renal tubular epithelial cells NRK52E were cultured under normal glucose (NG) and high glucose (HG) respectively, and the expression of Notch1 and LC3 proteins were detected by Western blotting. Autophagosomes in NRK52E cells with overexpressed and knockdown Notch1 under NG and HG conditions were observed by confocal microscope, and the expression changes of Notch1, Collagen-I and III protein were detected by immunofluorescence. The results showed that the Notch1 and Collagen-III expressions were increased (P < 0.01) and the LC3 expression was decreased (P < 0.05) in db/db mice compared with db/m mice. In vitro, the Notch1 was increased (P < 0.01) and the LC3 expression was decreased significantly (P < 0.01) in NRK52E cells of HG group compared with NG group. There was no significant change of Notch1 and LC3 expression between the mannitol (MA) group and the NG group. Autophagy was decreased and extracellular matrix deposition was aggravated when Notch1 was overexpressed. In contrast, autophagy was increased and extracellular matrix deposition was relieved by knockdown of Notch1 under HG conditions. In conclusion, Notch1 protein expression was increased and autophagy was reduced in renal tissue of diabetes and renal tubular epithelial cells under HG. The extracellular matrix deposition in the renal tubulointerstitium was relieved by regulating autophagy after the knockdown of Notch1.

Gene Mutation in Acute Lymphoblastic Leukemia by DNA Sequencing / 中国实验血液学杂志

OBJECTIVE@#To analyze the characteristics of gene mutation in adult ALL and its clinical significance.@*METHODS@#Clinical data of 134 primary adult ALL patients and DNA sequencing results of 16 kinds of gene mutation were collected. The characteristic of gene mutation and clinical significances were statistically analyzed.@*RESULTS@#In 31 cases of 134 ALL cases (23.13%) the gene mutations were detected as follows: 19 cases of 114 B-ALL cases (16.67%), 11 cases of 19 T-ALL cases (57.89%) and 1 case of T/B-ALL. The incidence of T-ALL gene mutation was significantly higher than that of B-ALL (χ@*CONCLUSION@#There may be multiple gene mutations in adult ALL patients. IL7R and NOTCH1 are the most common gene mutations and NOTCH1 mutation may indicate poor prognosis. Detection of gene mutations is helpful to understand the pathogenesis of ALL and evaluate the prognosis of adult ALL patients.

HtrA1 suppresses the growth of pancreatic cancer cells by modulating Notch-1 expression

Pancreatic cancer is well known to be the most deadly malignancy with the worst survival rate of all cancers. High temperature requirement factor A1 (HtrA1) plays an important role in cancer cell proliferation, migration, apoptosis, and differentiation. This study aimed to explore the function of HtrA1 in pancreatic cancer cell growth and its underlying mechanism. We found that the expression of HtrA1 was lower in pancreatic cancer tissue compared to the adjacent normal tissue. Consistently, HtrA1 levels were also decreased in two human pancreatic cancer cell lines, PANC-1 and BXPC-3. Moreover, enforced expression of HtrA1 inhibited cell viability and colony formation of PANC-1 and BXPC-3 cells. Overexpression of HtrA1 promoted apoptosis and suppressed migratory ability of tumor cells. On the contrary, siRNA-mediated knockdown of HtrA1 promoted the growth potential of pancreatic cancer cells. In addition, we found that up-regulation of HtrA1 reduced the expression of Notch-1 in pancreatic cancer cells. On the contrary, knockdown of HtrA1 increased the expression levels of Notch-1. Furthermore, overexpression of Notch-1 abolished the anti-proliferative effect of HtrA1 on pancreatic cancer cells. Taken together, our findings demonstrated that HtrA1 could inhibit pancreatic cancer cell growth via regulating Notch-1 expression, which implied that HtrA1 might be developed as a novel molecular target for pancreatic cancer therapy.

Sequential expressions of Notch1, Jagged2 and Math1 in molar tooth germ of mouse

The Notch signaling pathway is an evolutionary conserved mechanism that plays an important role in cell-cell communication and cell fate in a wide range of tissues. The mammalian family of Notch receptors consists of 4 members: Notch1/2/3/4. The Notch ligand family consists of 5 members: Delta1/3/4 and Jagged1/2. Math1 encodes a murine Basic helix-loop-helix (bHLH) transcription factor that acts as positive regulator of cell differentiation. Recently, links between Notch and Math1 pathways were demonstrated in various tissues. Expression of Notch1, Jagged2 and Math1 were analyzed in the mouse molar tooth germ during embryonic stage (E) 13 and E15 and during postnatal stage (PN) 1, PN3, PN5, PN10 and PN14 by using in situ hybridization. Positive Notch1 expression was found at the tooth bud during embryonic stages, but its expression was absent from the basal cells in contact with the dental mesenchyme. Jagged2 and Math1 were strongly expressed in differentiated ameloblasts and odontoblasts and Math1 strong expression was even maintained until PN14 stage. Math1 showed the strongest expression. Our results suggest that the Notch1 signaling pathway through Jagged2 could be importantly related to Math1, directing the process of odontogenesis toward cell differentiation.