Notoginsenoside R1 Promotes the Growth of Neonatal Rat Cortical Neurons via the Wnt/β-catenin Signaling Pathway

2018 ◽  
Vol 17 (7) ◽  
pp. 547-556 ◽  
Author(s):  
Xing-Tong Li ◽  
Wei Ma ◽  
Xian-Bin Wang ◽  
Zhang Liang ◽  
Jin-Wei Yang ◽  
...  

Background & Objective: Notoginsenoside R1 (NGR1) is one of the main effective components of Panax notoginseng. Method: Primary cortical neurons were harvested from neonatal rats and cultured to analyze the role of NGR1 in neuronal growth and the effects of NGR1 on the Wnt/β-catenin signaling pathway. Following treatment with NGR1, immunocytochemistry was used to detect expression of Tuj1 and MAP2, and RT-qPCR was used to measure mRNA levels of key factors in the Wnt signaling pathway. Results: Results showed that NGR1 promotes growth of cultured neurons and significantly upregulates mRNA levels of β-catenin, Dishevelled, and Frizzled. To further confirm whether NGR1 promoted cortical neuron growth via the Wnt/β-catenin signaling pathway, we knocked down β- catenin mRNA by siRNA interference; following NGR1 treatment of β-catenin-knockdown neurons, β-catenin mRNA levels increased significantly. Conclusion: In conclusion, these results demonstrate that NGR1 promotes growth of cultured cortical neurons from the neonatal rat, possibly via the Wnt/β-catenin signaling pathway.

1995 ◽  
Vol 74 (6) ◽  
pp. 2767-2773 ◽  
Author(s):  
S. J. Tavalin ◽  
E. F. Ellis ◽  
L. S. Satin

1. An in vitro cellular model of injury was used to elucidate mechanisms contributing to traumatic brain injury (TBI). Neonatal rat cortical neurons cultured on a flexible silastic membrane were stretched rapidly and reversibly by a 50-ms pulse of pressurized air. 2. Sublethal cell stretch depolarized neuronal resting membrane potential by approximately 10 mV but only if cells were incubated for 1 h after injury. Stretch-induced delayed depolarization (or SIDD) returned to baseline values within 24 h. 3. SIDD was dependent on the degree of cell stretch and required neuronal firing, calcium entry, and N-methyl-D-aspartate receptor activation for its induction but not its maintainance. 4. Similarities between SIDD and TBI suggest that SIDD may play a role in brain injury.


Biomedicines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1331
Author(s):  
Yung-Fu Wu ◽  
Chih-Yang Wang ◽  
Wan-Chun Tang ◽  
Yu-Cheng Lee ◽  
Hoang Dang Khoa Ta ◽  
...  

Colorectal cancer (CRC) is a heterogeneous disease with changes in the genetic and epigenetic levels of various genes. The molecular assessment of CRC is gaining increasing attention, and furthermore, there is an increase in biomarker use for disease prognostication. Therefore, the identification of different gene biomarkers through messenger RNA (mRNA) abundance levels may be useful for capturing the complex effects of CRC. In this study, we demonstrate that the high mRNA levels of 10 upregulated genes (DPEP1, KRT80, FABP6, NKD2, FOXQ1, CEMIP, ETV4, TESC, FUT1, and GAS2) are observed in CRC cell lines and public CRC datasets. Moreover, we find that a high mRNA expression of DPEP1, NKD2, CEMIP, ETV4, TESC, or FUT1 is significantly correlated with a worse prognosis in CRC patients. Further investigation reveals that CTNNB1 is the key factor in the interaction of the canonical Wnt signaling pathway with 10 upregulated CRC-associated genes. In particular, we identify NKD2, FOXQ1, and CEMIP as three CTNNB1-regulated genes. Moreover, individual inhibition of the expression of three CTNNB1-regulated genes can cause the growth inhibition of CRC cells. This study reveals efficient biomarkers for the prognosis of CRC and provides a new molecular interaction network for CRC.


2020 ◽  
Vol 70 (11) ◽  
pp. 1858-1870
Author(s):  
Shangqin Chen ◽  
Jinjin Zhu ◽  
Peijun Li ◽  
Zhaonan Xia ◽  
Mengjing Tu ◽  
...  

Abstract There are two major isoforms of NTRK2 (neurotrophic receptor tyrosine kinase 2, or TrkB), full-length isoform with tyrosine kinase (TK) domain intact (+) and spliced isoform without tyrosine kinase domain (TK(−)). Within each isoform, there exist subtypes with minor modifications of the protein sequences. In human, the NTRK2 mRNA transcripts encoding TK(+) have same 3′UTRs, while the transcripts encoding subtypes of NTRK2 TK(−) have two completely different 3′UTRs. In mouse, the mRNA transcripts encoding same NTRK2 protein sequence for either TK(+) or TK(−) have long or short 3′UTRs, respectively. The physiological functions of these different 3′UTRs are still unknown. Pilocarpine stimulation increased Ntrk2 mRNA levels in soma, while the increase in synaptosome was smaller. FISH results further showed that mouse Ntrk2 transcripts with different 3′UTRs were distributed differently in cultured cortical neurons. The transcripts with long 3′UTR were distributed more in apical dendrites compared with transcripts with short 3′UTR. Our results provide evidence of non-coding 3′UTR function in regulating mRNA distribution in neurons.


1997 ◽  
Vol 77 (1) ◽  
pp. 309-323 ◽  
Author(s):  
Thomas A. Blanpied ◽  
Faye A. Boeckman ◽  
Elias Aizenman ◽  
Jon W. Johnson

Blanpied, Thomas A., Faye Boeckman, Elias Aizenman, and Jon W. Johnson. Trapping channel block of NMDA-activated responses by amantadine and memantine. J. Neurophysiol. 77: 309–323, 1997. We investigated the mechanisms by which the antiparkinsonian and neuroprotective agents amantadine and memantine inhibit responses to N-methyl-d-aspartic acid (NMDA). Whole cell recordings were performed using cultured rat cortical neurons or Chinese hamster ovary (CHO) cells expressing NMDA receptors. Both amantadine and memantine blocked NMDA-activated channels by binding to a site at which they could be trapped after channel closure and agonist unbinding. For neuronal receptors, the IC50s of amantadine and memantine at −67 mV were 39 and 1.4 μM, respectively. When memantine and agonists were washed off after steady-state block, one-sixth of the blocked channels released rather than trapped the blocker; memantine exhibited “partial trapping.” Thus memantine appears to have a lesser tendency to be trapped than do phencyclidine or (5R,10S)-(+)-5m e t h y l - 1 0 , 1 1 - d i h y d r o - 5 H - d i b e n z o [ 1 , d ] c y c l i h e p t e n - 5 , 1 0 - i m i n e(MK-801). We next investigated mechanisms that might underlie partial trapping. Memantine blocked and could be trapped by recombinant NMDA receptors composed of NR1 and either NR2A or NR2B subunits. In these receptors, as in the native receptors, the drug was released from one-sixth of blocked channels rather than being trapped in all of them. The partial trapping we observed therefore was not due to variability in the action of memantine on a heterogeneous population of NMDA receptors in cultured cortical neurons. Amantadine and memantine each noncompetitively inhibited NMDA-activated responses by binding at a second site with roughly 100-fold lower affinity, but this form of inhibition had little effect on the extent to which memantine was trapped. A simple kinetic model of blocker action was used to demonstrate that partial trapping can result if the presence of memantine in the channel affects the gating transitions or agonist affinity of the NMDA receptor. Partial trapping guarantees that during synaptic communication in the presence of blocker, some channels will release the blocker between synaptic responses. The extent to which amantadine and memantine become trapped after channel block thus may influence their therapeutic effects and their modulation of NMDA-receptor-mediated excitatory postsynaptic potentials.


2021 ◽  
pp. 096032712110419
Author(s):  
Yueqiang Hu ◽  
Lin Wu ◽  
Lingfei Jiang ◽  
Ni Liang ◽  
Xiaomin Zhu ◽  
...  

Background: Alzheimer’s disease (AD) has affected numerous elderly individuals worldwide. Panax notoginseng has been shown to ameliorate AD symptoms, and notoginsenoside R2 is a key saponin identified in this plant. Purpose: In the current study, we aimed to explore whether notoginsenoside R2 could improve the prognosis of AD. Methods: Herein, primary rat cortical neurons were isolated and they were treated with amyloid beta-peptide (A β) 25–35 oligomers. Cellular apoptosis was examined via flow cytometry and Western blotting. miR-27a and SOX8 mRNA expression levels were quantified by quantitative reverse transcription-polymerase chain reaction. Furthermore, the interaction between miR-27a and SOX8 was investigated by utilizing a dual-luciferase reporter assay. Finally, an AD mouse model was established to validate the in vitro findings. Results: Notoginsenoside R2 alleviated A β25-35-triggered neuronal apoptosis and inflammation. During this process, miR-27a expression was decreased by notoginsenoside R2, and miR-27a negatively modulated SOX8 expression. Furthermore, activation of SOX8 upregulated β-catenin expression, thus suppressing apoptosis and neuroinflammation. Conclusions: Our animal experiments revealed that notoginsenoside R2 enhanced the cognitive function of AD mice and inhibited neuronal apoptosis. Notoginsenoside R2 ameliorated AD symptoms by reducing neuronal apoptosis and inflammation, thus suggesting a novel direction for AD pharmacotherapy.


2013 ◽  
Vol 33 (suppl_1) ◽  
Author(s):  
Asma Saleem ◽  
Eric W Howard ◽  
Latonya F Been ◽  
Megan Lerner ◽  
Daniel Brackett ◽  
...  

Type 2 (non-insulin-dependent) diabetes mellitus (T2DM) is associated with a marked increase in the risk of coronary heart disease. The discovery of TCF7L2 as a global T2DM gene has triggered investigations to explore the clinical utility of its variants for guiding the development of new diagnostic and therapeutic strategies. However, interpreting the resulting associations into function still remains unclear. Canonical Wnt signaling regulates β-catenin and its binding with TCF7L2, which in turn is critical for the production of glucagon like protein-1 (GLP-1). This study examines the role of a novel frame-shift insertion discovered in a conserved region of WNT16a, and it is proposed that this mutation affects T2DM susceptibility in conjunction with gene variants in TCF7L2. Our results predicted that the insertion would convert the upstream open reading frame in the Wnt16a mRNA to an alternative, in-frame translation initiation site, resulting in the prevention of nonsense-mediated decay that would normally occur in the wild-type message, leading to a consequent stabilization of the mutated WNT16a message. To examine the role of Wnt16a in the Wnt signaling pathway, DNA and serum samples from 2,034 individuals (48% with T2DM) from the Sikh Diabetes Study were used in this investigation, of which 32% were WNT16a insertion carriers. There was a 3.2 fold increase in Wnt16a mRNA levels in pancreatic tissues from the insertion carriers and a significant increase (70%, p<0.0001) in luciferase activity in the constructs carrying the insertion. The expression of TCF7L2 mRNA in pancreas was also elevated (~23-fold) among the insertion carriers (p=0.003). Our results suggest synergistic effects of WNT16a insertion mutants and the at-risk ‘T ‘allele of TCF7L2 (rs7903146) for compounding the risk of T2DM, perhaps by impacting genes related to β-cell function in the Wnt/β-catenin/TCF7L2 signaling pathway.


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