Neural stem cells (NSCs) are considered to be the most promising cell type for cell replacement therapy in neurodegenerative diseases. However, their low neuronal differentiation ratio impedes their application in such conditions. Elucidating the molecular mechanism of NSC differentiation may provide the necessary experimental basis for expanding their application. Previous studies have indicated that POU3F4 can induce neuronal differentiation of NSCs, this study aims to underly the possible exact mechanism of POU3F4 on the NSC differentiation and development. NSCs were isolated and cultured from the hippocampus of neonatal mice. The frozen hippocampal sections were prepared for immunohistochemical staining. Synaptic development was assessed using electron microscopy. High-throughput sequencing was employed to analyze the gene expression profile following the overexpression of Brn4. Gene expression levels were determined through Western blotting and qRT-PCR. Cell cycle and differentiation were evaluated using flow cytometry and immunofluorescent staining. It was found that POU3F4 promoted the neuronal differentiation of hippocampal NSCs and synapse development, and inhibited NSC proliferation. POU3F4-deficient mice exhibited impairments in learning and memory. RNA sequencing and ChIP assays confirmed that Gli1 was downstream of POU3F4. Loss and gain function experiments indicated that Gli1 mediated POU3F4 promoting neuronal differentiation and synapse development. Forced expression of Gli1 in hippocampus improved learning and memory function of animal models. The results suggest that POU3F4 and Gli1 promote neuronal differentiation and synaptic development of NSCs, and that Gli1 partially mediates the effects of POU3F4.
Abstract Background Lhx8, which is specifically expressed in the medial ganglionic eminence (MGE), is believed to be a key factor in the development of cholinergic neurons. Our previous studies have demonstrated that enhanced cholinergic neurogenesis occurs in the sub granular zone (SGZ) of the hippocampal dentate gyrus (DG) after cholinergic denervation, which is closely associated with the core transcription factor Lhx8. This study aims to explore the downstream targeted genes of Lhx8 involved in the differentiation of hippocampal neural stem cells (NSCs) into cholinergic neurons. Method Chromatin immunoprecipitation (ChIP) was applied to collect the targeted DNA fragments for Lhx8. DNA sequencing and bioinformatics analysis were performed to screen for the targeting genes related to neurogenesis. The expression of related targeting genes was verified by real-time quantitative polymerase chain reaction (PCR). Calpain 3 ( Capn3 ) was predicted to be associated with Lhx8. The interaction of Capn3 and Lhx8 was verified using luciferase reporter gene assay, and the gain- and loss-functions of Capn3 in NSC differentiation revealed the effects of Capn3 in cholinergic neurogenesis. Results ChIP analysis revealed 71 genes that Lhx8 targets upstream of its promoter within 1 k bp, and on bioinformatics analysis, Capn3 was identified as a candidate gene that Lhx8 targets. The gain function of Capn3 in Lentivirus (LV)-Lhx8 PC12 decreased the protein level of the cholinergic neuron marker choline acetyltransferase (ChAT), while down-regulation of Capn3 in LV-Lhx8 PC12 promoted protein expression of ChAT. Luciferase assay verified that Lhx8 could target the promoter region of Capn3 . In a hippocampus NSC differentiation assay, NSCs that overexpressed Capn3 had decreased differentiation into microtubule-associated protein 2 (MAP2)/ChAT-positive cholinergic neurons; however, down-regulation of Capn3 in NSCs increased the proportion of MAP2/ChAT-positive cholinergic neurons. Conclusion Capn3 may be a downstream target gene, negatively regulated by Lhx8, which can impede the cholinergic differentiation of hippocampus NSCs.
This study established a Couple Eulerian–Lagrange model to simulate monopile vibratory penetration for the investigation of soil plugging effect during high-frequency penetration of monopiles for wind turbine. Simulation analysis is focused particularly on soil plugging effect of a large diameter monopile during vibratory penetration into sand, clay, or layered soil. The results of the numerical simulation show that soil plugging effect is unlikely to occur during monopile penetration into the clay soil, while partial soil plugging may occur during the sand penetration. Penetration resistance at the pile toe is transferred to the radial stress around the pile wall. At a critical point penetration process, internal shaft friction becomes larger than external shaft friction. Moreover, radial pressure factors increase during partial soil plugging effect. For layered soil, the topsoil not only has great influence on the soil plugging effect, but also affects shaft friction in the subsoil during monopile penetration.
The technology of fragments reassembly is widely employed in many scientific fields, such as judicial evidence recovery, restoration of historic documents, accessing to military intelligence and so on, which is based on computer vision and pattern recognition. In this paper, an efficient method for Chinese fragments reassembly is presented. The proposed reassembly method is based on the feature of line spacing and Chinese characters’ feature that the same font has the same height. Considered the feature of English characters that English letters are connected components, this paper proposes a model for English fragments reassembly, which is based on template matching. Using the proposed methods on digitally scanned images of actual fragments of paper image prints has verified the robustness and reliability of two models.
Base stability of a deep excavation in clay is affected not only by soil properties such as soil strength and strength anisotropy, but also by several construction factors, such as the stiffness and depth of the excavation support wall and the depth of excavation. However, not all these influencing factors can be dealt with by the limit equilibrium methods currently used to analyze the base stability of a deep excavation in clay. The method proposed in this paper takes into account the influence of strength anisotropy and nonhomogeneity of soft clay, and the depth of the wall. The method is derived from the upper bound theory of bearing capacity and an assumed failure mechanism and is applied to study the base stability of deep excavations supported with internal braces and a concrete diaphragm wall in soft clay. To describe the strength anisotropy of soft clay, a total stress anisotropic strength criterion is adopted. The suitability of this method for analyzing the base stability of deep excavations is verified by comparison with numerical study results of deep excavations in Boston and a base failure case in Taipei. Limitations of this method, such as the minimum depth of excavation wall required and the lower bound ratio between the depth of the excavation wall and the width of excavation, are discussed also.
Abstract Background: Tumor biology would reflect the prognosis and potentially the lead time and over-diagnosis rate of screen-detected small breast cancer [PMID: 28591529, 21452022 and 24888816]. Chinese women had earlier peak age of breast cancer incidence and used ultrasound as the primary screening imaging test on a hospital-basis [2016 SABCS P5-02-05, PMID: 27689334]. In our previous work, we showed that US detected non-palpable breast cancer (NPBC) had higher percentage of invasive and lymph node positive cancer, yet still could be regarded as low-risk cancer [PMID:27689334, 28412736]. This study was performed to investigate the prognostic impact of immunohistochemical subtypes and tumor size: the smaller the NPBC, the better the tumor biology and prognosis? Methods: From January 2001 to December 2017, 6,423 consecutive asymptomatic women underwent mammography (MG) or ultrasound (US) guided biopsy in Peking Union Medical College Hospital. Among them, 159 T1a, 239 T1b, 377 T1c and 72 T2 NPBC were diagnosed and treated. The clinicopathological features, treatment choice, 10-year disease-free survival (DFS) and overall survival (OS) of the small NPBC (defined as≤1.0cm, T1a+b) were reviewed and compared with T1c and T2 NPBC. Prognostic factors of these subgroups of invasive NPBC were identified. Results: Compared to big NPBC, the T1a+b small NPBC showed more lymph node negative (p<0.001) and low Ki67 (<14%, p<0.001) cancers with earlier TNM stage (p<0.001), more luminal A subtype (p=0.003) and significantly improved 10-year DFS and OS (p=0.004). T1c+T2 NPBC had more triple-negative subtype and received more chemotherapy (p<0.001) and targeted therapy (p=0.008). Breast conserving rate and the use of radiation and endocrine therapy showed no significant difference. Table 1.Comparison of clinicopathological factors and long term survival of small vs big screen-detected NPBCScreen-detected NPBC(2001-2017 Clinical&prognostic factors T1a+T1b(n=398)T1c+T2(n=449)P valueScreening methodUS-NPBC(n,%)336(84.4)406(90.4)0.008 MG-NPBC(n,%)62(15.6)43(9.6) Lymph node statusNegative(n,%)343(86.2)315(70.2)<0.001 Positive(n,%)55(13.8)134(29.8) TNM stageI(n,%)344(86.4)277(61.7)<0.001 II(n,%)37(9.3)134(29.8) III(n,%)17(4.3)38(8.5) Ki67<14%(n,%)208(52.2)168(37.4)<0.001 ≥14%(n,%)183(46.0)274(61.0) SubtypeLuminal A(n,%)164(41.3)135(30.1)0.003 Luminal B(n,%)155(38.9)218(48.6) Her2(n,%)28(7.0)27(6.0) TNBC(n,%)31(7.8)52(11.6) Unknown(n,%)20(5.0)17(3.7) 10-year survivalDFS(%)94.688.80.004 OS(%)100.096.4 Conclusion: Small asymptomatic NPBCs were detected when small because they were good in terms of low Ki67 index, favorable subtype, tumor biology and long term prognosis. On the contrary, T1c and T2 NPBCs were screened when already big or even with positive nodes without clinical symptoms indicating that they might have larger chance of becoming interval cancers. Citation Format: Xu Y, Pan B, Yao R, Zhou Y-D, Mao F, Zhu Q-L, Wu H-W, Lin Y, Shen S-j, Sun Q. Long term survival and tumor biology of screen-detected small non-palpable breast cancer in Chinese women: The smaller, the better? [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-03-05.
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