Corynoxine triggers cell death via activating PP2A and regulating AKT-mTOR/GSK3ß axes in NSCLC.

This study investigates the anticancer activity and pharmacological mechanisms of Corynoxine (Cory) in non-small cell lung cancer (NSCLC). Cory, a natural product derived from the Chinese herbal medicine Uncaria rhynchophylla, demonstrates promising pharmacological activity. Cell proliferation and viability were evaluated via MTT and colony formation assays. Flow cytometry was employed to analyze cell apoptosis, cycle distribution, and mitochondrial membrane potential. Autophagy was detected using fluorescence microscopy and electron microscopy. Western blotting, protein overexpression, gene knockdown, co-immunoprecipitation, and bioinformatics characterized Cory's impact on signaling pathways. The research indicates that Cory inhibits the proliferation of NSCLC cells in vivo and in vitro. Cory enhances PP2A activity, inhibits the AKT/mTOR signaling pathway triggering autophagy, while suppressing the AKT/GSK3ß signaling pathway to induce cellular apoptosis in NSCLC. Notably, the activation of PP2A plays a crucial role in Cory's antitumor effects by inhibiting AKT. In vivo experiments validated Cory's efficacy in NSCLC treatment. These findings highlight the promising role of Cory as a lead compound for drug development in NSCLC therapy, providing a viable option for addressing this challenging disease.

Methyl donor supplementation reduces phospho-Tau, Fyn and demethylated protein phosphatase 2A levels and mitigates learning and motor deficits in a mouse model of tauopathy.

BACKGROUND: Reduced folate status and elevated levels of circulating homocysteine are modifiable risk factors for cognitive decline and dementia. Disturbances in one-carbon metabolism are associated with the pathological accumulation of phosphorylated tau, a hallmark feature of prevalent dementia, including Alzheimer's disease and subgroups of frontotemporal dementia. METHODS: Here, using transgenic TAU58/2 mouse models of human tauopathy, we tested whether dietary supplementation with L-methylfolate (the active folate form), choline and betaine can reduce tau phosphorylation and associated behavioural phenotypes. RESULTS: TAU58/2 mice fed with the methyl donor-enriched diet showed reduced phosphorylation of tau at the pathological S202 (CP13) and S396/S404 (PHF-1) epitopes and alleviation of associated motor and learning deficits. Compared with mice on the control diet, the decrease in cortical phosphorylated tau levels in mice fed with the methyl donor-enriched diet was associated with enhanced methylation of protein phosphatase 2A, the major brain tau Ser/Thr phosphatase. It also correlated with a reduction in protein levels of Fyn, a tau tyrosine kinase that plays a central role in mediating pathological tau-induced neurodegeneration. Conversely, Fyn expression levels were increased in mice with deficiencies in folate metabolism. CONCLUSIONS: Our findings provide the first experimental evidence that boosting one-carbon metabolism with L-methylfolate, choline and betaine can mitigate key pathological, learning and motor deficits in a tauopathy mouse model. They give support to using a combination of methyl donors as a preventive or disease-modifying strategy for tauopathies.

[Effects of Yizhi Tiaoshen acupuncture on learning and memory function and the expression of phosphorylated tau protein in the hippocampus of Alzheimer's disease model rats].

OBJECTIVE: To observe the effects of Yizhi Tiaoshen (benefiting mental health and regulating the spirit) acupuncture on learning and memory function, and the expression of phosphorylated tubulin-associated unit (tau) protein in the hippocampus of Alzheimer's disease (AD) model rats, and explore the effect mechanism of this therapy on AD. METHODS: A blank group and a sham-operation group were randomly selected from 60 male SD rats, 10 rats in each one. AD models were established in the rest 40 rats by the intraperitoneal injection of D-galactose and okadaic acid in the CA1 region of the bilateral hippocampus. Thirty successfully-replicated model rats were randomly divided into a model group, a western medication group and an acupuncture group, 10 rats in each one. In the acupuncture group, acupuncture was applied to "Baihui" (GV 20), "Sishencong" (EX-HN 1), "Neiguan" (PC 6), "Shenmen" (HT 7), "Xuanzhong" (GB 39) and "Sanyinjiao" (SP 6); and the needles were retained for 10 min. Acupuncture was given once daily. One course of treatment was composed of 6 days, with the interval of 1 day; the completion of treatment included 4 courses. In the western medication group, donepezil hydrochloride solution (0.45 mg/kg) was administrated intragastrically, once daily; it took 7 days to accomplish one course of treatment and a completion of intervention was composed of 4 courses. Morris water maze (MWM) and novel object recognition test (NORT) were used to assess the learning and memory function of the rats. Using HE staining and Nissl staining, the morphological structure of the hippocampus was observed. With Western blot adopted, the protein expression of the tau, phosphorylated tau protein at Ser198 (p-tau Ser198), protein phosphatase 2A (PP2A) and glycogen synthase kinase-3ß (GSK-3ß) in the hippocampus was detected. RESULTS: There were no statistical differences in all of the indexes between the sham-operation group and the blank group. Compared with the sham-operation group, in the model group, the MWM escape latency was prolonged (P<0.05), the crossing frequency and the quadrant stay time in original platform were shortened (P<0.05), and the NORT discrimination index (DI) was reduced (P<0.05); the hippocampal cell numbers were declined and the cells arranged irregularly, the hippocampal neuronal structure was abnormal and the numbers of Nissl bodies decreased; the protein expression of p-tau Ser198 and GSK-3ßwas increased (P<0.05) and that of PP2A decreased (P<0.05). When compared with the model group, in the western medication group and the acupuncture group, the MWM escape latency was shortened (P<0.05), the crossing frequency and the quadrant stay time in original platform were increased (P<0.05), and DI got higher (P<0.05); the hippocampal cell numbers were elevated and the cells arranged regularly, the damage of hippocampal neuronal structure was attenuated and the numbers of Nissl bodies were increased; the protein expression of p-tau Ser198 and GSK-3ß was reduced (P<0.05) and that of PP2A was increased (P<0.05). There were no statistically significant differences in the above indexes between the acupuncture group and the western medication group (P>0.05). CONCLUSION: Acupuncture therapy of "benefiting mental health and regulating the spirit" could improve the learning and memory function and alleviate neuronal injure of AD model rats. The effect mechanism of this therapy may be related to the down-regulation of GSK-3ß and the up-regulation of PP2A in the hippocampus, and then to inducing the inhibition of tau protein phosphorylation.

Effects of Yizhi Tiaoshen acupuncture on learning and memory function and the expression of phosphorylated tau protein in the hippocampus of Alzheimer's disease model rats / 中国针灸

OBJECTIVE@#To observe the effects of Yizhi Tiaoshen (benefiting mental health and regulating the spirit) acupuncture on learning and memory function, and the expression of phosphorylated tubulin-associated unit (tau) protein in the hippocampus of Alzheimer's disease (AD) model rats, and explore the effect mechanism of this therapy on AD.@*METHODS@#A blank group and a sham-operation group were randomly selected from 60 male SD rats, 10 rats in each one. AD models were established in the rest 40 rats by the intraperitoneal injection of D-galactose and okadaic acid in the CA1 region of the bilateral hippocampus. Thirty successfully-replicated model rats were randomly divided into a model group, a western medication group and an acupuncture group, 10 rats in each one. In the acupuncture group, acupuncture was applied to "Baihui" (GV 20), "Sishencong" (EX-HN 1), "Neiguan" (PC 6), "Shenmen" (HT 7), "Xuanzhong" (GB 39) and "Sanyinjiao" (SP 6); and the needles were retained for 10 min. Acupuncture was given once daily. One course of treatment was composed of 6 days, with the interval of 1 day; the completion of treatment included 4 courses. In the western medication group, donepezil hydrochloride solution (0.45 mg/kg) was administrated intragastrically, once daily; it took 7 days to accomplish one course of treatment and a completion of intervention was composed of 4 courses. Morris water maze (MWM) and novel object recognition test (NORT) were used to assess the learning and memory function of the rats. Using HE staining and Nissl staining, the morphological structure of the hippocampus was observed. With Western blot adopted, the protein expression of the tau, phosphorylated tau protein at Ser198 (p-tau Ser198), protein phosphatase 2A (PP2A) and glycogen synthase kinase-3β (GSK-3β) in the hippocampus was detected.@*RESULTS@#There were no statistical differences in all of the indexes between the sham-operation group and the blank group. Compared with the sham-operation group, in the model group, the MWM escape latency was prolonged (P<0.05), the crossing frequency and the quadrant stay time in original platform were shortened (P<0.05), and the NORT discrimination index (DI) was reduced (P<0.05); the hippocampal cell numbers were declined and the cells arranged irregularly, the hippocampal neuronal structure was abnormal and the numbers of Nissl bodies decreased; the protein expression of p-tau Ser198 and GSK-3βwas increased (P<0.05) and that of PP2A decreased (P<0.05). When compared with the model group, in the western medication group and the acupuncture group, the MWM escape latency was shortened (P<0.05), the crossing frequency and the quadrant stay time in original platform were increased (P<0.05), and DI got higher (P<0.05); the hippocampal cell numbers were elevated and the cells arranged regularly, the damage of hippocampal neuronal structure was attenuated and the numbers of Nissl bodies were increased; the protein expression of p-tau Ser198 and GSK-3β was reduced (P<0.05) and that of PP2A was increased (P<0.05). There were no statistically significant differences in the above indexes between the acupuncture group and the western medication group (P>0.05).@*CONCLUSION@#Acupuncture therapy of "benefiting mental health and regulating the spirit" could improve the learning and memory function and alleviate neuronal injure of AD model rats. The effect mechanism of this therapy may be related to the down-regulation of GSK-3β and the up-regulation of PP2A in the hippocampus, and then to inducing the inhibition of tau protein phosphorylation.

The protein phosphatase 2A catalytic subunit StPP2Ac2b is involved in the control of potato tuber sprouting and source-sink balance in tubers and sprouts.

Sprouting negatively affects the quality of stored potato tubers. Understanding the molecular mechanisms that control this process is important for the development of potato varieties with desired sprouting characteristics. Serine/threonine protein phosphatase type 2A (PP2A) has been implicated in several developmental programs and stress responses in plants. PP2A comprises a catalytic (PP2Ac), a scaffolding (A), and a regulatory (B) subunit. In cultivated potato, six PP2Ac isoforms were identified, named StPP2Ac1, 2a, 2b, 3, 4, and 5. In this study we evaluated the sprouting behavior of potato tubers overexpressing the catalytic subunit 2b (StPP2Ac2b-OE). The onset of sprouting and initial sprout elongation is significantly delayed in StPP2Ac2b-OE tubers; however, sprout growth is accelerated during the late stages of development, due to a high degree of branching. StPP2Ac2b-OE tubers also exhibit a pronounced loss of apical dominance. These developmental characteristics are accompanied by changes in carbohydrate metabolism and response to gibberellic acid, and a differential balance between abscisic acid, gibberellic acid, cytokinins, and auxin. Overexpression of StPP2Ac2b alters the source-sink balance, increasing the source capacity of the tuber, and the sink strength of the sprout to support its accelerated growth.

Synergistic antitumor effects of compound-composed optimal formula from Aidi injection on hepatocellular carcinoma and colorectal cancer.

BACKGROUND: Traditional Chinese medicine formula (TCMF) possesses unique advantages in the prevention and treatment of malignant tumors such as hepatocellular carcinoma (HCC) and colorectal cancer (CRC). However, the unclear chemical composition and mechanism lead to its unstable efficacy and adverse reactions occurring frequently, especially injection. We previously proposed the research idea and strategy for compound-composed Chinese medicine formula (CCMF). PURPOSE: A demonstration study was performed through screening of the compound-composed optimal formula (COF) from Aidi injection, confirmation of the synergistic effect, and exploration of the related mechanism in the treatment of HCC and CRC. METHOD: The feedback system control (FSC) technique was applied to screening of COF. CCK-8 and calcein-AM/PI assays were performed to evaluate cell proliferation. Cell apoptosis was assessed using flow cytometry and DAPI staining. JC-1 probe and mitochondrial staining were employed to detect mitochondrial membrane potential (MMP) and the release of cytochrome c into cytoplasm, respective. Quantitative proteomics, drug affinity responsive target stability (DARTS) assay, bioinformatics, and molecular docking were carried out to explore the targets of the compounds and the synergistic mechanism involved. RESULTS: COF was obtained from Aidi injection, which comprises cantharidin (CAN): calycosin-7-O-ß-D-glucoside (CAG): ginsenoside Rc: ginsenoside Rd = 1:12:12:8 (molar ratio). The monarch drug CAN in combination with minister medicines consisting of CAG, Rc and Rd (abbr. TD) displayed evidently synergistic effect, which inhibited cell viability, increased dead cell number, induced apoptosis, reduced MMP, promoted cytochrome c leakage of HCC and CRC cells, and suppressed the increases of tumor volume and weight in HCC and CRC bearing nude mice. TD probably antagonized CAN enhanced activity of the ubiquitin proteasome system (UPS) to depress the degradation of cytotoxic proteins through binding to ubiquitin proteasome, thus exerting the synergistic effect with CAN activated protein phosphatase 2A (PP2A) to activate the mitochondrial apoptosis pathway. In addition, the CAN enhanced protein expression of UPS was also observed for the first time. CONCLUSION: CAN and TD exert synergism through activation of PP2A and inhibition of UPS. It makes sense to elucidate the scientific nature of the compatibility theory of TCMF based on CCMF, which will be an important research direction of the modernization of traditional Chinese medicines.

(+)-Cyanidan-3-ol inhibits epidermoid squamous cell carcinoma growth via inhibiting AKT/mTOR signaling through modulating CIP2A-PP2A axis.

BACKGROUND: Despite recent advances in the treatment of squamous cell skin cancer (SCSC), the disease persists, and treatment resistance develops. Thus, identifying new targets and developing new therapeutic approaches showing low vulnerability to drug resistance is highly needed. PURPOSE: This study aimed to reveal a novel targeted phytotherapeutic strategy for SCSC treatment alone or in combination with standard targeted anticancer molecules. STUDY DESIGN: A library of natural products was utilized to identify molecules that inhibit the growth of skin cancer cells. The anticancer potential of the selected compound was evaluated in human skin squamous carcinoma models, in vitro and in vivo. A comprehensive ingenuity pathway analysis (IPA) strategy and molecular biology technology was adopted to investigate the therapeutic mechanisms in human SCSC. METHODS: The Matrigel invasion chamber, foci formation and soft agar colony formation assays were employed to study the cells invasion and migration potential in vitro. In vivo antitumor effects were evaluated in DMBA/TPA-induced skin papilloma and A431 human skin squamous carcinoma xenograft tumor models. An integrative IPA was employed to identify mechanisms and protein targets in human SCSC.Compounds synergies were determined by the bliss model and evaluated using human SCSC cell lines and xenograft tumors. Histological staining, immunofluorescence imaging, real-time PCR, Western blots, and flow cytometric analyses were employed to analyze apoptosis and cell signaling mechanisms. RESULTS: We identified (+)-cyanidan-3-ol (CD-3) as a selective compound for inhibiting the growth of SCSC cell lines. CD-3 inhibited tumor growth and burden without apparent toxicity and prolonged the survival of tumor-bearing mice. CD-3 inhibitory effects on SCSC growth are mediated via cell cycle arrest and caspase-dependent apoptosis induction. Mechanistic studies showed that CD-3 activates PP2A via inhibiting CIP2A and produces tumor growth inhibitory effects via promoting dephosphorylation of oncogenic AKT/mTOR signaling proteins in SCSC cells and xenograft tumors in a PP2A dependent manner. Furthermore, the combination of CD-3 and mTOR inhibitors (mTORi) synergistically reduced oncogenic phenotypes. CONCLUSIONS: Our study suggests that PP2A activation is an effective strategy for SCSC treatment and the CD-3 and mTORi combination may serve as a promising treatment for SCSC.

Combination of berberine and low glucose inhibits gastric cancer through the PP2A/GSK3ß/MCL-1 signaling pathway.

Intermittent fasting as an adjuvant therapy in clinical practice is an emerging treatment modality to target tumor growth by reducing glucose utilization. Berberine, an alkaloid extracted from the traditional Chinese medicine Coptidis Rhizoma, has been shown to be a safe and effective antitumor agent in several cancers. Hence, the purpose of the present study was to investigate the effects of the combination of berberine and low glucose on gastric cancer. Our results showed that the combination of berberine and low glucose effectively inhibited cell viability, promoted apoptosis, and reduced the migration ability of MGC803 cells. In addition, the combination was shown to activate the PP2A/GSK3ß signaling axis, leading to the downregulation of the downstream pro-survival protein MCL-1, which leads to the death of gastric cancer cells. In addition, the inhibitor of GSK3ß partially reversed the effect of this combination on MGC803 cells. In vivo experiments demonstrated that berberine effectively impaired the growth of xenograft tumors, when administered during intermittent fasting (hypoglycemic conditions), and was well tolerated by nude mice without the occurrence of any adverse effects. Based on these results, we conclude that the berberine/low-glucose combination can inhibit the growth of gastric cancer through the PP2A/GSK3ß/MCL-1 signaling pathway. Accordingly, this combination of drugs and lifestyle may become a new type of safe and effective anti-cancer therapy.

Excess folic acid supplementation before and during pregnancy and lactation activates ß-catenin in the brain of male mouse offspring.

Folic acid (FA) supplementation in early pregnancy is recommended to protect against birth defects. But excess FA has exhibited neurodevelopmental toxicity. We previously reported that the mice treated with 2.5-fold the dietary requirement of FA one week before mating and throughout pregnancy and lactation displayed abnormal behaviors in the offspring. Here we found the levels of non-phosphorylated ß-catenin (active) were increased in the brains of weaning and adult FA-exposed offspring. Meanwhile, demethylation of protein phosphatase 2 A catalytic subunit (PP2Ac), which suppresses its enzyme activity in regulatory subunit dependent manner, was significantly inhibited. Among the upstream regulators of ß-catenin, PI3K/Akt/GSK-3ß but not Wnt signaling was stimulated in FA-exposed brains only at weaning. In mouse neuroblastoma N2a cells, knockdown of PP2Ac or leucine carboxyl methyltransferase-1 (LCMT-1), or overexpression of PP2Ac methylation-deficient mutant decreased ß-catenin dephosphorylation. These results suggest that excess FA may activate ß-catenin via suppressing PP2Ac demethylation, providing a novel mechanism for the influence of FA on neurodevelopment.

AGSE: A Novel Grape Seed Extract Enriched for PP2A Activating Flavonoids That Combats Oxidative Stress and Promotes Skin Health.

Environmental stimuli attack the skin daily resulting in the generation of reactive oxygen species (ROS) and inflammation. One pathway that regulates oxidative stress in skin involves Protein Phosphatase 2A (PP2A), a phosphatase which has been previously linked to Alzheimer's Disease and aging. Oxidative stress decreases PP2A methylation in normal human dermal fibroblasts (NHDFs). Thus, we hypothesize agents that increase PP2A methylation and activity will promote skin health and combat aging. To discover novel inhibitors of PP2A demethylation activity, we screened a library of 32 natural botanical extracts. We discovered Grape Seed Extract (GSE), which has previously been reported to have several benefits for skin, to be the most potent PP2A demethylating extract. Via several fractionation and extraction steps we developed a novel grape seed extract called Activated Grape Seed Extract (AGSE), which is enriched for PP2A activating flavonoids that increase potency in preventing PP2A demethylation when compared to commercial GSE. We then determined that 1% AGSE and 1% commercial GSE exhibit distinct gene expression profiles when topically applied to a 3D human skin model. To begin to characterize AGSE's activity, we investigated its antioxidant potential and demonstrate it reduces ROS levels in NHDFs and cell-free assays equal to or better than Vitamin C and E. Moreover, AGSE shows anti-inflammatory properties, dose-dependently inhibiting UVA, UVB and chemical-induced inflammation. These results demonstrate AGSE is a novel, multi-functional extract that modulates methylation levels of PP2A and supports the hypothesis of PP2A as a master regulator for oxidative stress signaling and aging in skin.

Magnesium isoglycyrrhizinate prevents cadmium-induced activation of JNK and apoptotic hepatocyte death by reversing ROS-inactivated PP2A.

OBJECTIVES: Cadmium (Cd) induces reactive oxygen species (ROS)-mediated hepatocyte apoptosis and consequential liver disorders. This study aimed to investigate the effect of magnesium isoglycyrrhizinate (MgIG) on Cd-induced hepatotoxicity. METHODS: L02 and AML-12 cells were used to study MgIG hepatoprotective effects. Cd-evoked apoptosis, ROS and protein phosphatase 2A (PP2A)/c-Jun N-terminal kinase (JNK) cascade disruption were analysed by cell viability assay, 6-diamidino-2-phenylindole (DAPI) and TdT-mediated dUTP Nick-End Labeling (TUNEL) staining, ROS imaging and Western blotting. Pharmacological and genetic approaches were used to explore the mechanisms. KEY FINDINGS: We show that MgIG attenuated Cd-evoked hepatocyte apoptosis by blocking JNK pathway. Pre-treatment with SP600125 or ectopic expression of dominant-negative c-Jun enhanced MgIG's anti-apoptotic effects. Further investigation found that MgIG rescued Cd-inactivated PP2A. Inhibition of PP2A activity by okadaic acid attenuated the MgIG's inhibition of the Cd-stimulated JNK pathway and apoptosis; in contrast, overexpression of PP2A strengthened the MgIG effects. In addition, MgIG blocked Cd-induced ROS generation. Eliminating ROS by N-acetyl-l-cysteine abrogated Cd-induced PP2A-JNK pathway disruption and concurrently reinforced MgIG-conferred protective effects, which could be further slightly strengthened by PP2A overexpression. CONCLUSIONS: Our findings indicate that MgIG is a promising hepatoprotective agent for the prevention of Cd-induced hepatic injury by mitigating ROS-inactivated PP2A, thus preventing JNK activation and hepatocyte apoptosis.

Combination of docosahexaenoic acid and Ginko biloba extract improves cognitive function and hippocampal tissue damages in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) is one of the most common neurodegenerative diseases characterized by a progressive loss of memory and other cognitive functions among elder people. Nowadays, natural antioxidants have been used to recover the quality of life for those with AD. In this study, we investigated, for the first time, the combined effect of docosahexaenoic acid (DHA) and Ginkgo bilobastandardized extract (EGb761) on AD mice. AD was induced in adult male albino mice with AlCl3 (20 mg/kg b.w, i.g.) and D-galactose (D-gal; 120 mg/kg, i.p.) for 90 days. 30 days after induction, mice were treated with DHA (200 mg/kg b.w., i.g.) and EGb761 (200 mg/kg b.w., i.g.) for two months. Our data revealed that the dual treatment of DHA and EGb761 significantly improved cognitive memory and spatial learning abilities in AD-induced mice. The drug treatments preserved the hippocampal CA3 architecture and restored neuronal ultrastructural alterations. Expression of protein phosphatase 2A (PP2A), the most implicated protein phosphatase in AD neurodegeneration, was highly upregulated in the CA3 hippocampus of AD mice treated with DHA and EGb761. Intriguingly, TNF-α expression was significantly reduced in the same group. In conclusion, our findings proved that the combined effect of DHA and EGb761 tended to be potent against the neurodegenerative effect of AlCl3 and D-gal. The applied treatment enhanced neuronal survival and cognitive functions via upregulation of PP2A and restoration of TNF-α expression.

Polyphyllin VII induces mitochondrial apoptosis by regulating the PP2A/AKT/DRP1 signaling axis in human ovarian cancer.

Ovarian cancer is a gynecological malignancy with high mortality. Adjuvant therapy such as chemoradiotherapy inevitably leads to side effects and drug resistance. In recent years, traditional Chinese medicine has been widely studied for its safety, effectiveness, and unique pharmacological effects. Polyphyllin VII is an important component of Rhizoma paridis saponins, and has cytotoxic effects on many types of cancer cells. The aim of the present study was to evaluate the anti­tumor activity of polyphyllin VII in human ovarian cancer cells. Recent studies found that polyphyllin VII induces mitochondrial pathway apoptosis by increasing mitochondrial division, but the specific mechanism was unclear. The results of this study revealed that polyphyllin VII could effectively induce mitochondrial dysfunction, including increased mitochondrial division and reactive oxygen species (ROS) production. Notably, the mitochondrial location of dynamin­related protein 1 (DRP1) plays an important role in its function. In addition, polyphyllin VII enhanced the mitochondrial localization of DRP1 which is mediated by increased protein phosphatase 2A (PP2A) activity, and decreased AKT activity. A specific PP2A inhibitor, LB100, attenuated mitochondrial division and apoptosis in cells caused by polyphyllin VII, confirming the function of the PP2A/AKT pathway in polyphyllin VII treatment. Additionally, xenotransplantation experiments have also confirmed the anti­tumor effect of polyphyllin VII in vivo. Therefore, interference of the mitochondrial translocation of DRP1 through PP2A/AKT pathway may be an attractive and effective therapeutic approach by polyphyllin VII in ovarian cancer. This may provide new strategies for polyphyllin VII in the clinical treatment of ovarian cancer.

Metformin and omega-3 fish oil elicit anti-inflammatory effects via modulation of some dysregulated micro RNAs expression and signaling pathways in experimental induced arthritis.

OBJECTIVE: Rheumatoid arthritis is a progressive inflammatory disease with multiple dysfunctional intracellular signaling pathways that necessitate new approaches for its management. Hence, the study aimed to inspect the ability of the combination therapy of metformin and omega-3 to modulate different signaling pathways and micro RNAs such as (miR-155, miR-146a and miR-34) as new targets in order to mitigate adjuvant-induced arthritis and compare their effect to that of methotrexate. METHODS: Fourteen days post adjuvant injection, Sprague-Dawley rats were treated orally with metformin (200 mg/kg/day) and/or omega-3 (300 mg/kg/day) or intraperitoneally with methotrexate (2 mg/kg/week) for 4 weeks. RESULTS AND CONCLUSION: All drug treatments amended the arthrogram score and hind paw swelling as well as decreased serum tumor necrosis factor (TNF)-α and interleukin (IL)-1ß levels. On the molecular level, all therapies activated phospho-5'adenosine monophosphate-activated protein kinase (p-AMPK) and protein phosphatase 2A (PP2A), while they inhibited phospho-mammalian target of rapamycin (p-mTOR), phospho-signal transducers and activators of transcription (p-STAT3), nuclear factor (NF)-κB p65 subunit, phosho38 mitogen-activated protein kinase (p38 MAPK) and phospho- c-Jun N-terminal kinase (p-JNK). In addition, they decreased the elevated expression level of miRNA-155, 146a and increased the expression level of miRNA-34 and they decreased the expression level of retinoic acid receptor related orphan receptor γT (RORγT) and increased that of fork head box P3 (FOXP3), correcting Th17/Treg cells balance. On most of the aforementioned parameters, the effect of the combination therapy was comparable to that of methotrexate, emphasizing that this combination possesses better additive anti-inflammatory effect than either drug when used alone. In addition, the combination was capable of normalizing the serum transaminases levels as compared to untreated group offering hepatoprotective effect and suggesting the possibility of its use as a replacement therapeutic strategy for MTX in rheumatoid arthritis.

Chronic Sodium Selenate Treatment Restores Deficits in Cognition and Synaptic Plasticity in a Murine Model of Tauopathy.

A major goal in diseases is identifying a potential therapeutic agent that is cost-effective and can remedy some, if not all, disease symptoms. In Alzheimer's disease (AD), aggregation of hyperphosphorylated tau protein is one of the neuropathological hallmarks, and Tau pathology correlates better with cognitive impairments in AD patients than amyloid-ß load, supporting a key role of tau-related mechanisms. Selenium is a non-metallic trace element that is incorporated in the brain into selenoproteins. Chronic treatment with sodium selenate, a non-toxic selenium compound, was recently reported to rescue behavioral phenotypes in tau mouse models. Here, we focused on the effects of chronic selenate application on synaptic transmission and synaptic plasticity in THY-Tau22 mice, a transgenic animal model of tauopathies. Three months with a supplement of sodium selenate in the drinking water (12 µg/ml) restored not only impaired neurocognitive functions but also rescued long-term depression (LTD), a major form of synaptic plasticity. Furthermore, selenate reduced the inactive demethylated catalytic subunit of protein phosphatase 2A (PP2A) in THY-Tau22 without affecting total PP2A.Our study provides evidence that chronic dietary selenate rescues functional synaptic deficits of tauopathy and identifies activation of PP2A as the putative mechanism.

S-Adenosylmethionine Rescues Cognitive Deficits in the rTg4510 Animal Model by Stabilizing Protein Phosphatase 2A and Reducing Phosphorylated Tau.

BACKGROUND: Alterations in the methionine cycle and abnormal tau phosphorylation are implicated in many neurodegenerative diseases, including Alzheimer's disease and frontotemporal dementia. rTg4510 mice express mutant human P301L tau and are a model of tau hyperphosphorylation. The cognitive deficit seen in these animals correlates with a burden of hyperphosphorylated tau and is a model to test therapies aimed at lowering phosphorylated tau. OBJECTIVE: This study aimed to increase protein phosphatase 2A activity through supplementation of S-adenosylmethionine and analyze the effect on spatial memory and tau in treated animals. METHODS: 6-month-old rTg4510 mice were treated with 100 mg/kg S-adenosylmethionine by oral gavage for 3 weeks. Spatial recognition memory was tested in the Y-maze. Alterations to phosphorylated tau and protein phosphatase 2A were explored using immunohistochemistry, western blot, and enzyme-linked immunosorbent assays. RESULTS: Treatment with S-adenosylmethionine increased the Y-maze novel arm exploration time and increased both the expression and activity of protein phosphatase 2A. Furthermore, treatment reduced the number of AT8 positive neurons and reduced the expression of phosphorylated tau (Ser202/Thr205). S-adenosylmethionine contributes to multiple pathways in neuronal homeostasis and neurodegeneration. CONCLUSION: This study shows that supplementation with S-adenosylmethionine stabilizes the heterotrimeric form of PP2A resulting in an increase the enzymatic activity, a reduced level of pathological tau, and improved cognition.

Target of rapamycin regulates potassium uptake in Arabidopsis and potato.

Potassium (K) is an essential inorganic nutrient needed by plants for their growth and development. The conserved target of rapamycin (TOR) kinase, a well-known nutrition signaling integrator, has crucial roles in regulating growth and development in all eukaryotes. Emerging evidence suggests that TOR is a core regulator of nutrient absorption and utilization in plants. However, it is still unclear whether there is a causative link between the TOR pathway and potassium absorption. Here, we show that the expression of some potassium transporters and channels was regulated by TOR, and the suppression of TOR activity significantly affected potassium uptake in Arabidopsis and potato. Furthermore, we discovered that a Type 2A phosphatase-associated protein of 46 kDa (TAP46), a direct TOR downstream effector, could interact with CBL-interacting protein kinase 23 (CIPK23) in Arabidopsis and potato. In Arabidopsis, the K+ channel AKT1 conducting K+ uptake was significantly regulated by Calcineurin B-like Calcium Sensor Protein 1/9 (CBL1/9)-CIPK23 modules. We found that the cbl1cbl9, cipk23 (lks1-2 and lks1-3), and akt1 mutants were more hyposensitive to the TOR inhibitor than the wild-type, and the TOR inhibitor induced the downregulation of K+ uptake rate in the wild-type more than in these mutants. In addition, the overexpression of CIPK23 could effectively restore the defects in growth and potassium uptake induced by the TOR inhibitors. Thus, our work reveals a link between TOR signaling and CIPK23 and provides new insight into the regulation of potassium uptake in plants.

HYVIA™: A novel, topical chia seed extract that improves skin hydration.

BACKGROUND: Chia seeds have gained importance as it is the highest known plant source of omega-3 (ω3) polyunsaturated fatty acids. Specifically, chia seeds possess ω3 α-linolenic acid (ALA) and ω6 linoleic acid (LA), together known as Vitamin F, which play an important role in maintaining skin function. Protein phosphatase 2A (PP2A) is a master regulatory protein that plays a critical role in skin barrier function and its activity is modulated by natural lipids. AIMS: Obtain a chia seed extract (HYVIA™) with significant higher levels of Vitamin F, determine in vitro PP2A activity and skin hydration markers compared to other commercial chia seed extracts (CCSEs), and evaluate the potential skin hydration benefits clinically in human subjects. METHODS: A PP2A demethylation assay was utilized to assess PP2A activity. In vitro studies utilizing normal human epidermal keratinocytes (NHEKs) were treated with HYVIA™ and gene expression of hydration markers (AQP3, HAS2) were measured by quantitative PCR (qPCR). A 16-subject clinical trial was performed with 0.1% HYVIA™ formulated in a cream and applied topically to assess its skin moisturizing potential. RESULTS: We demonstrate here that HYVIA™, ALA, and LA inhibit PP2A demethylation, boosting PP2A activity, while most other CCSEs do not. Unlike other CCSEs, HYVIA™ increases keratinocyte hydration factors aquaporin-3 and hyaluronic acid synthase-2 in vitro. Clinical assessment of 0.1% HYVIA™ cream shows that HYVIA™ improves skin hydration. CONCLUSIONS: HYVIA™ is a novel chia seed extract, enriched for Vitamin F, that modulates PP2A activity and clinically improves skin hydration and barrier function.

[Mechanism of Effects of Genistein on the Reproductive System of Prepubertal Male Rats].

OBJECTIVE: To study the effects of genistein (GEN) on reproductive system in prepubertal male rats. METHODS: Thirty SPF-rated male SD rats were randomly divided into control group (Con group), low-dose group (G1 group) and high-dose group (G2 group), with 10 rats in each group. Corn oil, 150 mg/kg and 300 mg/kg GEN dissolved in corn oil of equal volume were respectively administered every day and weighed the next day. After 6 weeks, the rats were sacrificed, and the testis, epididymis and prostate were dissected, and organ coefficients were calculated. Histopathological changes of testis was observed. The number of sperm was counted and the rate of sperm malformation was calculated. The concentrations of serum testosterone and estradiol were detected by radioimmunoassay. The protein phosphatase 2, regulatory subunit B, gamma (PPP2R2C) protein expression in testicular tissue was detected by immunofluorescence assay. The mRNA and protein expression levels of PPP2R2C and cyclin dependent protein kinases 2 (CDK2) in rat testis were detected by real-time quantitative fluorescence PCR (RT-qPCR) and Western blot, respectively. The protein phosphatase 2A (PP2A) activity in testicular tissue was detected by immunoprecipitation. RESULTS: There were no statistically significant differences in body mass, sperm number, serum estradiol and PP2A enzyme activity among the groups ( P>0.05). The pathological structure of testicular in G2 group was disordered. Sperm abnormality rate in G1 and G2 groups was higher than that in Con group ( P<0.05). Serum testosterone concentration in G2 group was lower than that in Con group ( P<0.05). The expression of PPP2R2C and CDK2 in G2 group was higher than that in Con group ( P<0.05), but the protein level was lower than that in Con group ( P<0.05). PPP2R2C protein was expressed in testicular tissue in each group. CONCLUSION: Long-term exposure to high dose (300 mg/kg) GEN during prepuberty may cause adverse effects on reproductive function in adult male rats. Further investigation is needed to determine whether PPP2R2C-PP2A-CDK2 phosphorylation pathway affects reproductive system in rats.

Cathepsin B mediated scramblase activation triggers cytotoxicity and cell cycle arrest by andrographolide to overcome cellular resistance in cisplatin resistant human hepatocellular carcinoma HepG2 cells.

Andrographolide regimen in single or in combination with anticancer drugs is a promising new strategy to reverse chemoresistance in heaptocellular carcinoma. Apoptosis inducing factor (AIF) may regulate a complementary, cooperative or redundant pathway, along with caspase cascades. Despite these findings, mechanisms underlying caspase-dependent and-independent signaling pathways in andrographolide -induced apoptosis in cisplatin-resistant human hepatocellular carcinoma cell line (HepG2CR) remain unclear. Andrographolide treatment effectively reduced NF-κß nuclear localization by modulating protein kinase A- protein phosphatase 2 A- Iκß kinase (PKA/PP2 A/IKK) axis that in turn maintains initiator caspase8 activity. Lysosomal distribution of tBid stimulates cytosolic cathepsin B resulting accumulation of truncated-AIF with induction in scramblase mediated phosphatidylserine exposure in HepG2CR cells. Andrographolide treatment thereby switch on subG1 phase arrest by modulating cellular check points (cyclin A, B, cyclin dependent kinase-1) cueing to the apoptosis event. Collectively, this study suggested antineoplastic potential of andrographolide through PKA/PP2 A/IKK pathway in HepG2CR cells.