scholarly journals Anger Emotional Stress Influences VEGF/VEGFR2 and Its Induced PI3K/AKT/mTOR Signaling Pathway

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Sun ◽  
Sheng Wei ◽  
Xia Wei ◽  
Jieqiong Wang ◽  
Yuanyuan Zhang ◽  
...  

Objective.We discuss the influence of anger emotional stress upon VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway.Methods.We created a rat model of induced anger (anger-out and anger-in) emotional response using social isolation and resident-intruder paradigms and assessed changes in hippocampus’ VEGF content, neuroplasticity, and the PI3K/AKT/mTOR signaling pathway.Results.The resident-intruder method successfully generated anger-out and anger-in models that differed significantly in composite aggression score, aggression incubation, open field behavior, sucrose preference, and weight gain. Anger emotional stress decreased synaptic connections and VEGFR2 expression. Anger emotional stress led to abnormal expression of VEGF/VEGFR2 mRNA and protein and disorderly expression of key factors in the PI3K/AKT/mTOR signal pathway. Fluoxetine administration ameliorated behavioral abnormalities and damage to hippocampal neurons caused by anger emotional stress, as well as abnormal expression of some proteins in VEGF/VEGFR2 and its induced PI3K/AKT/mTOR signal pathway.Conclusion.This research provides a detailed classification of anger emotion and verifies its influence upon VEGF and the VEGF-induced signaling pathway, thus providing circumstantial evidence of mechanisms by which anger emotion damages neurogenesis. As VEGFR2 can promote neurogenesis and vasculogenesis in the hippocampus and frontal lobe, these results suggest that anger emotional stress can result in decreased neurogenesis.

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jianwen Long ◽  
Xianming Pi

To investigate whether Polyphyllin I (PPI) might induce the autophagy and apoptosis of melanoma cells by regulating PI3K/Akt/mTOR signal pathway. Melanoma A375 cells were incubated with different concentrations of Polyphyllin I (0, 1.5, 3.0, and 6.0 mg/L) and PI3K/Akt/mTOR signaling pathway activator IGF-1(20 mg/L). CCK-8 assay was utilized to detect cell proliferation; Cell apoptosis and cell cycle were measured by flow cytometry; Western blot was used to examine the expressions of proteins. Immunofluorescence analysis was performed to evaluate autophagy of A375 cells; In addition, xenograft-bearing nude mice were applied to study the role of Polyphyllin I on melanoma development, melanoma cell proliferation, as well as melanoma cell apoptosis in vivo. The outcomes represented that Polyphyllin I promoted A375 cell apoptosis via upregulating Bax level and cleaved caspase-3 level and downregulating Bcl-2 level, inhibited the growth of A375 cells at the G0/G1 phase, and enhanced cell autophagy via regulating the levels of Beclin 1, LC3II, and p62. However, IGF-1 (an activator of PI3K/Akt/mTOR signal pathway) attenuated these changes that Polyphyllin I induced. Furthermore, the xenograft model experiment confirmed that Polyphyllin I treatment suppressed xenograft tumor growth, increased apoptotic index evaluated by the TUNEL method, and reduced the level of Ki67 in tumor tissues in vivo. In conclusion, Polyphyllin I treatment enhanced melanoma cell autophagy and apoptosis, as well as blocked melanoma cell cycle via suppressing PI3K/Akt/mTOR signal pathway. Meanwhile, Polyphyllin I treatment suppressed the development of melanoma in vivo. Therefore, Polyphyllin I possibly is a promising molecular targeted agent used in melanoma therapy.


2021 ◽  
Vol 12 ◽  
Author(s):  
Yin Cao ◽  
Qinglin Li ◽  
An Zhou ◽  
Zunji Ke ◽  
Shengqi Chen ◽  
...  

Sleep deprivation (SD) may cause serious neural injury in the central nervous system, leading to impairment of learning and memory. Melatonin receptor 1A (MTNR1A) plays an important role in the sleep regulation upon activation by melatonin. The present study aimed to investigate if notoginsenoside R1 (NGR1), an active compound isolated from Panax notoginseng, could alleviate neural injury, thus improve impaired learning and memory of SD mice, as well as to explore its underlying action mechanism through modulating MTNR1A. Our results showed that NGR1 administration improved the impaired learning and memory of SD mice. NGR1 prevented the morphological damage and the accumulation of autophagosomes in the hippocampus of SD mice. At the molecular level, NGR1 reversed the expressions of proteins involved in autophagy and apoptosis, such as beclin-1, LC3B, p62, Bcl-2, Bax, and cleaved-caspase 3. Furthermore, the effect of NGR1 was found to be closely related with the MTNR1A-mediated PI3K/Akt/mTOR signaling pathway. On HT-22 cells induced by autophagy inducer rapamycin, NGR1 markedly attenuated excessive autophagy and apoptosis, and the alleviative effect was abolished by the MTNR1A inhibitor. Taken together, NGR1 was shown to alleviate the impaired learning and memory of SD mice, and its function might be exerted through reduction of excessive autophagy and apoptosis of hippocampal neurons by regulating the MTNR1A-mediated PI3K/Akt/mTOR signaling pathway.


2011 ◽  
Vol 300 (3) ◽  
pp. E554-E563 ◽  
Author(s):  
Xuemei Shi ◽  
Xiaojie Li ◽  
Yi Wang ◽  
Keying Zhang ◽  
Fuguo Zhou ◽  
...  

Glucagon-like peptide-2 (GLP-2) is a nutrient-responsive neuropeptide that exerts diverse actions in the gastrointestinal tract, including enhancing mucosal cell survival and proliferation. GLP-2 stimulates mucosal growth in vivo with an increased rate of protein synthesis. However, it was unclear whether GLP-2 can directly stimulate protein synthesis. The objective was to test critically whether GLP-2 receptor (GLP-2R) activation directly stimulates protein synthesis through a PI 3-kinase-dependent Akt-mTOR signaling pathway. HEK 293 cells (transfected with human GLP-2R cDNA) were treated with human GLP-2 with/without pretreatment of PI 3-kinase inhibitor (LY-294002) or mTOR inhibitor (rapamycin). Results show that 1) GLP-2 specifically bound to GLP-2R overexpressed in the HEK cells with Ka = 0.22 nM and Bmax = 321 fmol/μg protein; 2) GLP-2-stimulated protein synthesis was dependent on the amount of GLP-2R cDNA and the dosage of GLP-2 and reached the plateau among 0.2–2 nM GLP-2; 3) GLP-2-stimulated protein synthesis was abolished by the PI 3-kinase inhibitor and mTOR inhibitor; and 4) GLP-2-mediated stimulation of phosphorylation on Akt and mTOR was dependent on the amount of GLP-2R cDNA transfected and the dosage of GLP-2. In addition, GLP-2-mediated action and signaling in regulation of protein synthesis were confirmed in mouse hippocampal neurons (expressing native GLP-2R). GLP-2 directly stimulated protein synthesis of primary cultured neurons in dosage-dependent, PI 3-kinase-dependent, and rapamycin-sensitive manners, which linked with activation of Akt-mTOR signaling pathway as well. We conclude that GLP-2R activation directly stimulates protein synthesis by activating the PI 3-kinase-dependent Akt-mTOR signaling pathway. GLP-2-stimulated protein synthesis may be physiologically relevant to maintaining neuronal long-term potentiation and providing secondary mediators (namely neuropeptides or growth factors).


2020 ◽  
Author(s):  
Minfen Zhang ◽  
Hui Chen ◽  
Ping Qin ◽  
Tonghui Cai ◽  
Lingjun Li ◽  
...  

2020 ◽  
Vol 27 ◽  
Author(s):  
Naser-Aldin Lashgari ◽  
Nazanin Momeni Roudsari ◽  
Saeideh Momtaz ◽  
Negar Ghanaatian ◽  
Parichehr Kohansal ◽  
...  

: Inflammatory bowel disease (IBD) is a general term for a group of chronic and progressive disorders. Several cellular and biomolecular pathways are implicated in the pathogenesis of IBD, yet the etiology is unclear. Activation of the mammalian target of rapamycin (mTOR) pathway in the intestinal epithelial cells was also shown to induce inflammation. This review focuses on the inhibition of the mTOR signaling pathway and its potential application in treating IBD. We also provide an overview on plant-derived compounds that are beneficial for the IBD management through modulation of the mTOR pathway. Data were extracted from clinical, in vitro and in vivo studies published in English between 1995 and May 2019, which were collected from PubMed, Google Scholar, Scopus and Cochrane library databases. Results of various studies implied that inhibition of the mTOR signaling pathway downregulates the inflammatory processes and cytokines involved in IBD. In this context, a number of natural products might reverse the pathological features of the disease. Furthermore, mTOR provides a novel drug target for IBD. Comprehensive clinical studies are required to confirm the efficacy of mTOR inhibitors in treating IBD.


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