Leptin exerts an anti-apoptotic effect on human dendritic cells via the PI3K-Akt signaling pathway

Leptin is an adipocyte-derived hormone/cytokine that modulates immune responses. It induces functional and morphological changes in human dendritic cells (DCs), licensing them towards Th1 priming and promoting DC survival. Here we found that leptin protects DCs from spontaneous, UVB and H₂O₂-induced apoptosis, by triggering the activation of nuclear factor-kappa B (NF-kB) and a parallel up-regulation of bcl-2 and bcl-XL gene expression and Akt activation. We found that leptin activates the PI3K-Akt signaling pathway as demonstrated by the suppression of the effect of leptin on DC survival by wortmannin and API-2, which suppress the leptin-induced activation of Akt, NF-kB, bcl-2, bcl-XL and protection from apoptosis. These results provide insights on the immunoregulatory function of leptin, supporting a potential application in immunotherapeutic approaches.     

Oligomannose-coated liposomes activate ERK via Src kinases and PI3K/Akt in J774A.1 cells

We have previously shown that liposomes coated with a neoglycolipid constructed from mannotriose and dipalmitoylphosphatidylethanolamine (Man3-DPPE) activate peritoneal macrophages to induce enhanced expression of co-stimulatory molecules and MHC class II. In this study, we investigated the signaling pathways activated by the Man3-DPPE-coated liposomes (OMLs) in a murine macrophage cell line, J774A.1. In response to OML stimulation, ERK among MAPKs was clearly and transiently phosphorylated in J774 cells. ERK phosphorylation was also induced by treatment of the cells with Man3-DPPE and Man3-BSA, but not by uncoated liposomes. In addition, rapid and transient phosphorylation of Akt and Src family kinases (SFKs) was observed in response to OMLs. OML-induced ERK phosphorylation was inhibited by specific inhibitors of PI3K and SFKs, and OML-induced Akt phosphorylation was inhibited by a inhibitor of SFKs. Therefore, OMLs may activate the PI3K/Akt pathway through phosphorylation of Src family kinases to induce ERK activation.     

Apoptosis in medfly hemocytes is regulated during pupariation through FAK, Src, ERK, PI-3K p85a, and Akt survival signaling

Focal adhesion kinase (FAK) and its downstream signaling targets are implicated in the process of apoptosis induced by external stimuli, in several mammalian systems. In this report, we demonstrate, that medfly (Ceratitis capitata) hemocytes do undergo apoptosis during larval development. In particular, we show using Western blot, ELISA and flow cytometry analysis, that FAK expression silencing in transfected by FAK double-stranded RNA (dsRNA) hemocytes, enhances twofold hemocyte apoptosis, by signaling through Src, MEK/ERK, and PI-3K/Akt signaling pathways. FAK expression silencing, in response to FAK dsRNA treatment, blocks partially the phosphorylation of its downstream targets. Pre-incubation of hemocytes, with specific inhibitors of FAK downstream signaling molecules, demonstrated that all these inhibitors reduced hemocyte viability and enhanced the magnitude of apoptosis about threefold. This data suggest that these pathways contribute to hemocyte survival and/or death during development. The expression and phosphorylation of FAK, Src, PI-3K p85a, Akt, and ERK signaling molecules appear to be dependent upon developmental stages. The expression and phosphorylation of the above signaling molecules, in annexin-positive and annexin-negative hemocytes is also distinct. The maximum expression and phosphorylation of FAK, Src, PI-3K p85a, Akt, and ERK appeared in annexin-positive hemocytes, in both early and late apoptotic hemocytes. The novel aspect of this report is based on the fact that hemocytes attempt to suppress apoptosis, by increasing the expression/phosphorylation of FAK and, hence its downstream targets signaling molecules Src, ERK, PI-3K p85a, and Akt. Evidently, the basic survival pathways among insects and mammals appear to remain unchanged, during evolution.     

BDNF regulates primary dendrite formation in cortical neurons via the PI3‐kinase and MAP kinase signaling pathways

Neurotrophins are known to regulate dendritic development, but the mechanisms that mediate neurotrophin‐dependent dendrite formation are largely unknown. Here we show that brain‐derived neurotrophic factor (BDNF) induces the formation of primary dendrites in cortical neurons by a protein synthesis‐independent mechanism. BDNF leads to the rapid activation of PI3‐kinase, MAP kinase, and PLC‐γ in cortical neurons, and pharmacological inhibition of PI3‐kinase and MAP kinase in dissociated cell cultures and cortical slice cultures suppresses the ability of BDNF to induce dendrite formation. A constitutively active form of PI3‐kinase, but not MEK, is sufficient to induce primary dendrite formation in cortical neurons. These observations indicate that BDNF induces primary dendrite formation via activation of the PI3‐kinase and MAP kinase pathways and provide insight into the mechanisms that mediate the morphological effects of neurotrophin signaling. © 2004 Wiley Periodicals, Inc. J Neurobiol, 2005     

Inhibition of insulin signaling in endothelial cells by protein kinase C-induced phosphorylation of p85 subunit of phosphatidylinositol 3-kinase (PI3K)

The regulation of endothelial function by insulin is consistently abnormal in insulin-resistant states and diabetes. Protein kinase C (PKC) activation has been reported to inhibit insulin signaling selectively in endothelial cells via the insulin receptor substrate/PI3K/Akt pathway to reduce the activation of endothelial nitric-oxide synthase (eNOS). In this study, it was observed that PKC activation differentially inhibited insulin receptor substrate 1/2 (IRS1/2) signaling of insulin's activation of PI3K/eNOS by decreasing only tyrosine phosphorylation of IRS2. In addition, PKC activation, by general activator and specifically by angiotensin II, increased the phosphorylation of p85/PI3K, which decreases its association with IRS1 and activation. Thr-86 of p85/PI3K was identified to be phosphorylated by PKC activation and confirmed to affect IRS1-mediated activation of Akt/eNOS by insulin and VEGF using a deletion mutant of the Thr-86 region of p85/PI3K. Thus, PKC and angiotensin-induced phosphorylation of Thr-86 of p85/PI3K may partially inhibit the activation of PI3K/eNOS by multiple cytokines and contribute to endothelial dysfunction in metabolic disorders.     

Downregulation of NEAT1 reverses the radioactive iodine resistance of papillary thyroid carcinoma cell via miR-101-3p/FN1/PI3K-AKT signaling pathway

Considering the resistance of papillary thyroid cancer (PTC) ¹³¹I therapy, this study was designed to find a solution at molecular respect. By probing into lncRNA-NEAT1/miR-101-3p/FN1 axis and PI3K/AKT signaling pathway, this study provided a potential target for PTC therapy. ¹³¹I-resistant cell lines were established by continuous treatment with median-lethal ¹³¹I. Bioinformatic analysis was applied to filtrate possible lncRNA/miRNA/mRNA and related signaling pathway. Luciferase reporter assay was employed in the verification of the targeting relationship between lncRNA and miRNA as well as miRNA and mRNA. MTT assay and flow cytometry assay were performed to observe the impact of NEAT1/miR-101-3p/FN1 on cell viability and apoptosis in radioactivity iodine (RAI)-resistant PTC cell lines, respectively. Western blot and qRT-PCR were conducted to measure the expression of proteins and mRNAs in RAI-resistant PTC tissues and cells. Meanwhile, endogenous PTC mice model were constructed, in order to verify the relation between NEAT1 and RAI-resistance in vivo. NEAT1 was over-expressed in RAI-resistant PTC tissues and cell lines and could resist RAI by accelerating proliferation accompanied by suppressing apoptosis. It indicated that overexpressed NEAT1 restrained the damage of RAI to tumor in both macroscopic and microcosmic. Besides, NEAT1/miR-101-3p exhibited a negative correlation by directly targeting each other. The expression of FN1, an overexpressed downstream protein in RAI-resistance PTC tissues, could be tuned down by miR-101-3p, while the decrease could be restored by NEAT1. In conclusion, both in vitro and in vivo, NEAT1 suppression could inhibit ¹³¹I resistance of PTC by upregulating miR-101-3p/FN1 expression and inactivated PI3K/AKT signaling pathway both in vitro and in vivo.     

Involvement of MAP-kinase, PI3-kinase and EGF-receptor in the stimulatory effect of Neurotensin on DNA synthesis in PC3 cells

The mechanism by which neurotensin (NT) promotes the growth of prostate cancer epithelial cells is not yet defined. Here, androgen-independent PC3 cells, which express high levels of the type 1 NT-receptor (NTR1), are used to examine the involvement of epidermal growth factor receptor (EGFR), mitogen-activated protein kinases (ERK, SAPK/JNK and p38), PI3 kinase and PKC in the mitogenic effect of NT. NT dose dependently (0.1–30 nM) enhanced phosphorylation of EGFR, ERK and Akt, reaching maximal levels within 3 min as measured by Western blotting. These effects were associated with an accumulation of EGF-like substance(s) in the medium (assayed by EGFR binding) and a 2-fold increase in DNA synthesis (assayed by [³H]thymidine incorporation). The DNA synthesis enhancement by NT was non-additive with that of EGF. The NT-induced stimulation of EGFR/ERK/Akt phosphorylation and DNA synthesis was inhibited by EGFR-tyrosine kinase inhibitors (AG1478, PD153035), metallo-endopeptidase inhibitor phosphoramidon and by heparin, but not by neutralizing anti-EGF antibody. Thus, transactivation of EGFR by NT involved heparin-binding EGF (HB-EGF or amphiregulin) rather than EGF. The effects of NT on EGFR/ERK/Akt activation and DNA synthesis were attenuated by PLC-inhibitor (U73122), PKC-inhibitors (bisindolylmaleimide, staurosporine, rottlerin), MEK inhibitor (U0126) and PI3 kinase inhibitors (wortmannin, LY 294002). We conclude that NT stimulated mitogenesis in PC3 cells by a PKC-dependent ligand-mediated transactivation of EGFR, which led to stimulation of the Raf–MEK–ERK pathway in a PI3 kinase-dependent manner.     

Amniotic fluid exerts a neurotrophic influence on fetal neurodevelopment via the ERK/GSK-3 pathway

Background

The fetus is surrounded by the amniotic fluid (AF) contained by the amniotic sac of the pregnant female. The AF is directly conveyed to the fetus during pregnancy. Although AF has recently been reported as an untapped resource containing various substances, it remains unclear whether the AF could influence fetal neurodevelopment.

Results

We used AF that was extracted from embryos at 16 days in pregnant SD rat and exposed the AF to the neural cells derived from the embryos of same rat. We found that the treatment of AF to cortical neurons increased the phosphorylation in ERK1/2 that is necessary for fetal neurodevelopment, which was inhibited by the treatment of MEK inhibitors. Moreover, we found the subsequent inhibition of glycogen synthase kinase-3 (GSK-3), which is an important determinant of cell fate in neural cells. Indeed, AF increased the neural clustering of cortical neurons, which revealed that the clustered cells were proliferating neural progenitor cells. Accordingly, we confirmed the ability of AF to increase the neural progenitor cells through neurosphere formation. Furthermore, we showed that the ERK/GSK-3 pathway was involved in AF-mediated neurosphere enlargement.

Conclusions

Although the placenta mainly supplies oxygenated blood, nutrient substances for fetal development, these findings further suggest that circulating-AF into the fetus could affect fetal neurodevelopment via MAP kinases-derived GSK-3 pathway during pregnancy. Moreover, we suggest that AF could be utilized as a valuable resource in the field of regenerative medicine.     

PKCalpha reduces the lipid kinase activity of the p110alpha/p85alpha PI3K through the phosphorylation of the catalytic subunit

The modulation of phosphoinositide 3-kinase (PI3K) activity influences the quality of cellular responses triggered by various receptor tyrosine kinases. Protein kinase C (PKC) has been reported to phosphorylate signalling molecules upstream of PI3K and thereby it may affect the activation of PI3K. Here, we provide the first evidence for a direct effect of a PKC isoenzyme on the activity of PI3K. PKCalpha but not PKCepsilon phosphorylated the catalytic subunit of the p110alpha/p85alpha PI3K in vitro in a manner inhibited by the PKC inhibitor bisindolylmaleimide I (BIM I). The incubation of PI3K with active PKCalpha resulted in a significant decrease in its lipid kinase activity and this effect was also attenuated by BIM I. We conclude that PKCalpha is able to modulate negatively the lipid kinase activity of the p110alpha/p85alpha PI3K through the phosphorylation of the catalytic subunit.     

Prolactin-stimulated activation of ERK1/2 mitogen-activated protein kinases is controlled by PI3-kinase/Rac/PAK signaling pathway in breast cancer cells

There is strong evidence that deregulation of prolactin (PRL) signaling contributes to pathogenesis and chemoresistance of breast cancer. Therefore, understanding cross-talk between distinct signal transduction pathways triggered by activation of the prolactin receptor (PRL-R), is essential for elucidating the pathogenesis of metastatic breast cancer.In this study, we applied a sequential inhibitory analysis of various signaling intermediates to examine the hierarchy of protein interactions within the PRL signaling network and to evaluate the relative contributions of multiple signaling branches downstream of PRL-R to the activation of the extracellular signal-regulated kinases ERK1 and ERK2 in T47D and MCF-7 human breast cancer cells.Quantitative measurements of the phosphorylation/activation patterns of proteins showed that PRL simultaneously activated Src family kinases (SFKs) and the JAK/STAT, phosphoinositide-3 (PI3)-kinase/Akt and MAPK signaling pathways. The specific blockade or siRNA-mediated suppression of SFK/FAK, JAK2/STAT5, PI3-kinase/PDK1/Akt, Rac/PAK or Ras regulatory circuits revealed that (1) the PI3-kinase/Akt pathway is required for activation of the MAPK/ERK signaling cascade upon PRL stimulation; (2) PI3-kinase-mediated activation of the c-Raf-MEK1/2-ERK1/2 cascade occurs independent of signaling dowstream of STATs, Akt and PKC, but requires JAK2, SFKs and FAK activities; (3) activated PRL-R mainly utilizes the PI3-kinase-dependent Rac/PAK pathway rather than the canonical Shc/Grb2/SOS/Ras route to initiate and sustain ERK1/2 signaling. By interconnecting diverse signaling pathways PLR may enhance proliferation, survival, migration and invasiveness of breast cancer cells.     

Mollugin induces tumor cell apoptosis and autophagy via the PI3K/AKT/mTOR/p70S6K and ERK signaling pathways

Mollugin, a bioactive phytochemical isolated from Rubia cordifolia L., has shown preclinical anticancer efficacy in various cancer models. However the effects of mollugin in regulating cancer cell survival and death remains undefined. In the present study we found that mollugin exhibited cytotoxicity on various cancer models. The suppression of cell viability was due to the induction of mitochondria apoptosis. In addition, the presence of autophagic hallmarks was observed in mollugin-treated cells. Notably, blockade of autophagy by a chemical inhibitor or RNA interference enhanced the cytotoxicity of mollugin. Further experiments demonstrated that phosphatidylinositide 3-kinases/protein kinase B/mammalian target of rapamycin/p70S6 kinase (PI3K/AKT/mTOR/p70S6K) and extracellular regulated protein kinases (ERK) signaling pathways participated in mollugin-induced autophagy and apoptosis. Together, these findings support further studies of mollugin as candidate for treatment of human cancer cells.     

Compensatory effects in the PI3K/PTEN/AKT signaling network following receptor tyrosine kinase inhibition

Overcoming de novo and acquired resistance to anticancer drugs that target signaling networks is a formidable challenge for drug design and effective cancer therapy. Understanding the mechanisms by which this resistance arises may offer a route to addressing the insensitivity of signaling networks to drug intervention and restore the efficacy of anticancer therapy. Extending our recent work identifying PTEN as a key regulator of Herceptin sensitivity, we present an integrated theoretical and experimental approach to study the compensatory mechanisms within the PI3K/PTEN/AKT signaling network that afford resistance to receptor tyrosine kinase (RTK) inhibition by anti-HER2 monoclonal antibodies. In a computational model representing the dynamics of the signaling network, we define a single control parameter that encapsulates the balance of activities of the enzymes involved in the PI3K/PTEN/AKT cycle. By varying this control parameter we are able to demonstrate both distinct dynamic regimes of behavior of the signaling network and the transitions between those regimes. We demonstrate resistance, sensitivity, and suppression of RTK signals by the signaling network. Through model analysis we link the sensitivity-to-resistance transition to specific compensatory mechanisms within the signaling network. We study this transition in detail theoretically by variation of activities of PTEN, PI3K, AKT enzymes, and use the results to inform experiments that perturb the signaling network using combinatorial inhibition of RTK, PTEN, and PI3K enzymes in human ovarian carcinoma cell lines. We find good alignment between theoretical predictions and experimental results. We discuss the application of the results to the challenges of hypersensitivity of the signaling network to RTK signals, suppression of drug resistance, and efficacy of drug combinations in anticancer therapy.     

PTEN suppression promotes neurite development exclusively in differentiating PC12 cells via PI3‐kinase and MAP kinase signaling

As a dual‐specificity phosphatase catalyzing the dephosphorylation of phosphatidylinositols and protein substrates, PTEN is critically involved in the nervous system development. However, the regulatory role of PTEN in neurite outgrowth is still controversial, and the downstream signaling events remain elusive. Here, we show that PTEN knockdown promoted the proliferation and survival but not the neurite outgrowth of rat pheochromocytoma PC12 cells when exposed to nerve growth factor (NGF). In contrast, selective PTEN silencing in differentiating PC12 cells that express nestin significantly facilitated neurite elongation. Elevated Akt and Erk1/2 phosphorylation was involved in accelerated NGF‐induced neurite development of PC12 cells following PTEN knockdown. Discriminated roles of the lipid phosphatase and protein phosphatase activities of PTEN in neurite development, as well as the detailed molecular profiles affected by these phosphatase activities, were defined by restored expression of a lipid phosphatase‐deficient PTEN mutant following endogenous PTEN silencing in PC12 cells. Our study suggests an overall inhibitory effect of PTEN in neurite development reconciled by a probably indispensable role of this phosphatase in the initiation of PC12 cell differentiation. J. Cell. Biochem. 111: 1390–1400, 2010. © 2010 Wiley‐Liss, Inc.     

CB-RAF600E-1 exerts efficacy in vemurafenib-resistant and non-resistant-melanoma cells via dual inhibition of RAS/RAF/MEK/ERK and PI3K/Akt signaling pathways

Background and AimPredicting novel dual inhibitors to combat adverse effects such as the development of resistance to vemurafenib in melanoma treatment due to the reactivation of MAPK and PI3K/AKT signaling pathways is studied to help in reversal of cancer symptoms.Reversal of cancer symptoms in melanoma associated with vemurafenib resistance is driven by reactivation of MAPK and PI3K/Akt signaling pathways. Novel dual inhibitors targeting these proteins would be beneficial to combat resistance.MethodsHigh-throughput virtual screening of the ChemBridge library against B-RAFV600E and Akt was performed using an automated protocol with the AutoDock VINA program. Luminescence and time-resolved fluorescence kits were used to measure enzyme activities. The MTT assay was used to determine proliferation in normal and vemurafenib-resistant A375 cells. Flow cytometry was used to examine apoptosis, cell cycle, and phosphorylation of ERK/Akt signaling pathway.ResultsHigh-throughput screening from the ChemBridge library identified 15 compounds with high binding energy towards B-RAFV600E; among these, CB-RAF600E-1 had the highest ΔG_binding score −11.9 kcal/mol. The compound also had a high affinity towards Akt, with a ΔG_binding score of −11.5 kcal/mol. CB-RAF600E-1 dose-dependently inhibited both B-RAFV600E and Akt with IC₅₀ values of 635 nM and 154.3 nM, respectively. The compound effectively controlled the proliferations of normal and vemurafenib-resistant A375 cells, with GI₅₀ values of 222.3 nM and 230.5 nM, respectively. A dose-dependent increase in the sub G₀/G₁ phase of the cell cycle and total apoptosis was observed following compound treatment in both normal and vemurafenib-resistant melanoma cells. Treatment with CB-RAF600E-1 decreased the pERK/pAkt dual-positive populations in normal and vemurafenib-resistant A375 cells.ConclusionCB-RAF600E-1, identified as a novel dual inhibitor effective against normal and vemurafenib-resistant melanoma cells, requires further attention for development as an effective chemotherapeutic agent for melanoma management.     

Phosphopeptide binding to the N-terminal SH2 domain of the p85 alpha subunit of PI 3'-kinase: a heteronuclear NMR study.

The N-terminal src-homology 2 domain of the p85 alpha subunit of phosphatidylinositol 3' kinase (SH2-N) binds specifically to phosphotyrosine-containing sequences. Notably, it recognizes phosphorylated Tyr 751 within the kinase insert of the cytoplasmic domain of the activated beta PDGF receptor. A titration of a synthetic 12-residue phosphopeptide (ESVDY*VPMLDMK) into a solution of the SH2-N domain was monitored using heteronuclear 2D and 3D NMR spectroscopy. 2D-(15N-1H) heteronuclear single-quantum correlation (HSQC) experiments were performed at each point of the titration to follow changes in both 15N and 1H chemical shifts in NH groups. When mapped onto the solution structure of the SH2-N domain, these changes indicate a peptide-binding surface on the protein. Line shape analysis of 1D profiles of individual (15N-1H)-HSQC peaks at each point of the titration suggests a kinetic exchange model involving at least 2 steps. To characterize changes in the internal dynamics of the domain, the magnitude of the (15N-1H) heteronuclear NOE for the backbone amide of each residue was determined for the SH2-N domain with and without bound peptide. These data indicate that, on a nanosecond timescale, there is no significant change in the mobility of either loops or regions of secondary structure. A mode of peptide binding that involves little conformational change except in the residues directly involved in the 2 binding pockets of the p85 alpha SH2-N domain is suggested by this study.     

Activation of MAP kinase by MC4-R through PI3 kinase

The melanocortin 4 receptor (MC4-R) is a G_s-coupled receptor known to increase cAMP production following agonist stimulation. We demonstrate that the mitogen-activated protein kinases p42 (ERK2) and p44 (ERK1) are also activated by MC4-R following treatment with the MC4-R agonist NDP--MSH in stably transfected CHO-K1 cells. This time- and dose-dependent response is abolished by the MC4-R antagonist SHU-9119. p42/p44 MAPK activation is blocked by the phosphatidylinositol 3-kinase (PI3K) inhibitors wortmannin and LY294002 but not by the protein kinase A (PKA) inhibitor Rp-cAMPS, indicating that that signal activating the p42/p44 MAPK pathway is conveyed through inositol triphosphate.     

P42 Ebp1 regulates the proteasomal degradation of the p85 regulatory subunit of PI3K by recruiting a chaperone-E3 ligase complex HSP70/CHIP

The short isoform of ErbB3-binding protein 1 (Ebp1), p42, is considered to be a potent tumor suppressor in a number of human cancers, although the mechanism by which it exerts this tumor-suppressive activity is unclear. Here, we report that p42 interacts with the cSH2 domain of the p85 subunit of phosphathidyl inositol 3-kinase (PI3K), leading to inhibition of its lipid kinase activity. Importantly, we found that p42 induces protein degradation of the p85 subunit and further identified HSP70/CHIP complex as a novel E3 ligase for p85 that is responsible for p85 ubiquitination and degradation. In this process, p42 couples p85 to the HSP70/CHIP-mediated ubiquitin–proteasomal system (UPS), thereby promoting a reduction of p85 levels both in vitro and in vivo. Thus, the tumor-suppressing effects of p42 in cancer cells are driven by negative regulation of the p85 subunit of PI3K.     

Evaluating the effect of ginsenoside Rg1 on CPF-induced brain injury in mice via PI3k/AKT pathway

Organophosphorus pesticides (OPs) have long been used extensively on agricultural land and can lead to significant improvements in crop yields. Due to occupational exposure, humans are exposed to pesticides through dermal contact, inhalation, and ingestion. The effects of OPs on the organism are currently studied for their effects on livers, kidneys, hearts, blood indicators, neurotoxicity, and teratogenic, carcinogenic, and mutagenic effects, while studies in the direction of brain tissue damage have not been reported in detail. Previous reports have confirmed that ginsenoside Rg1 is a prominent and representative tetracyclic triterpenoid derivative rich in ginseng and has good neuroprotective activity. Considering that, the aim of this study was to establish a mouse model of brain tissue injury by using the OP-type pesticide chlorpyrifos (CPF) and to explore the therapeutic effects and possible molecular mechanisms of Rg1. Mice in the experimental group were pre-protected with Rg1 by gavage for 1 week, and brain tissue damage was induced using CPF (5 mg/kg for 1 week) to assess the effect of Rg1 (80 and 160 mg/kg for 3 weeks) in alleviating brain damage. Morris water maze and histopathological analysis were performed to assess cognitive function and pathological changes in the mouse brain, respectively. Protein expression levels of Bax, Bcl-2, Caspase-3, Cl-Cas-3, Caspase-9, Cl-Cas-9, phosphoinositide 3-kinase (PI3K), phosphorylated-PI3K, protein kinase B (AKT), and phosphorylated-AKT were quantified by protein blotting analysis. Rg1 obviously restored CPF-induced oxidative stress damage in mouse brain tissue, increased the levels of antioxidant parameters (total superoxide dismutase, total antioxidative capacity, and glutathione) in the brain, and significantly reduced the overexpression of apoptosis-related proteins induced by CPF. At the same time, Rg1 also markedly attenuated the histopathological changes in the brain induced by CPF exposure. Mechanistically, Rg1 could effectively activate the phosphorylation of PI3K/AKT. Furthermore, molecular docking studies revealed a stronger binding capacity between Rg1 and PI3K. Rg1 attenuated neurobehavioural alterations and reduced lipid peroxidation in the mouse brain to a great extent. Apart from that, Rg1 administration improved brain histopathology in CPF-induced rats. All results suggest that ginsenoside Rg1 has potential antioxidant effects on CPF-induced oxidative brain injury, and it is evident that Rg1 could be used as a promising therapeutic strategy for the study of brain injury from OP poisoning.