Contactin -Associated protein1 Regulates Autophagy by Modulating the PI3K/AKT/mTOR Signaling Pathway and ATG4B Levels in Vitro and in Vivo.

Contactin-associated protein1 (Caspr1) plays an important role in the formation and stability of myelinated axons. In Caspr1 mutant mice, autophagy-related structures accumulate in neurons, causing axonal degeneration; however, the mechanism by which Caspr1 regulates autophagy remains unknown. To illustrate the mechanism of Caspr1 in autophagy process, we demonstrated that Caspr1 knockout in primary neurons from mice along with human cell lines, HEK-293 and HeLa, induced autophagy by downregulating the PI3K/AKT/mTOR signaling pathway to promote the conversion of microtubule-associated protein light chain 3 I (LC3-I) to LC3-II. In contrast, Caspr1 overexpression in cells contributed to the upregulation of this signaling pathway. We also demonstrated that Caspr1 knockout led to increased LC3-I protein expression in mice. In addition, Caspr1 could inhibit the expression of autophagy-related 4B cysteine peptidase (ATG4B) protein by directly binding to ATG4B in overexpressed Caspr1 cells. Intriguingly, we found an accumulation of ATG4B in the Golgi apparatuses of cells overexpressing Caspr1; therefore, we speculate that Caspr1 may restrict ATG4 secretion from the Golgi apparatus to the cytoplasm. Collectively, our results indicate that Caspr1 may regulate autophagy by modulating the PI3K/AKT/mTOR signaling pathway and the levels of ATG4 protein, both in vitro and in vivo. Thus, Caspr1 can be a potential therapeutic target in axonal damage and demyelinating diseases.

Predictive factors and a novel nomogram for recurrence of primary retroperitoneal liposarcoma: Comprehensive analysis of 128 cases.

Since primary retroperitoneal liposarcoma (PRPLS) is rare in the clinic, related clinical studies are lacking. The present study was designed to investigate the predictive factors of short-term (≤1 year) recurrence (STR) and construct a novel nomogram of local recurrence-free survival (LRFS) for surgically resected PRPLS. A total of 128 PRPLS cases who underwent radical surgery were retrospectively analyzed. Based on the interval from the operation to tumor recurrence, the predictors of STR were screened using univariate and multivariate logistic regression analyses. Cox proportional hazard regression models were applied to identify the predictors of LRFS. Furthermore, the independent predictors acquired from multivariate analyses were used to construct a nomogram. Multivariate logistic regression analysis revealed that age ≥55 years [odds ratio (OR)=5.607, P=0.010], operative time ≥260 min (OR=9.716, P=0.005) and tumor necrosis (OR=3.781, P=0.037) were independent risk factors of STR for PRPLS. In the Cox regression analysis, clinical symptoms [hazard ratio (HR)=1.746, P=0.017], resection method (OR=0.370, P=0.021) and de-differentiated histological subtype (HR=1.975, P=0.048) were identified as independent predictors of LRFS. Subsequently, the independent predictors acquired from multivariate analyses were used to construct a nomogram for LRFS. Age, operative time, tumor necrosis, clinical symptoms, resection method and histological subtype were related to recurrence for surgically resected PRPLS and a novel nomogram was constructed based on the above predictors.

Triterpenoids, steroids and other constituents from Euphorbia kansui and their anti-inflammatory and anti-tumor properties.

Six undescribed triterpenoids (euphokanols A-F), two undescribed C21-steroidal glycosides (euphokanosides A and B), together with fifty-four known compounds were isolated from the roots of Euphorbia kansui. Their structures were demonstrated by extensive spectroscopic data (1D, 2D NMR and HR-ESI-MS), and the absolute configuration of euphokanol A was elucidated based on electronic circular dichroism (ECD) calculation. Among them, euphokanol A was a tetracyclic triterpenoid with a 5,10-epoxy moiety and concurrent rearrangement of Me-19(10 â†’ 9) and Me-30 (14 â†’ 8), while euphokanols B and C were rare 19(10 â†’ 9) abeo-tirucallane-type triterpenoids with Δ5(10) double bonds and 7,8-epoxy moieties. In addition, ten C21-steroidal glycosides were isolated from Euphorbia plants for the first time. Moreover, cynotophylloside B, caudatin, 5α,8α-epidioxy-22E-ergosta-6,22-diene-3ß-ol, 6ß,7ß-epoxy-3ß,4ß,5ß-trihydroxyl-20-deoxyingenol, 13-hydroxyingenol-3-(2,3- dimethylbutanoate)-13-dodecanoate, ingenol, 3-O-benzoyl-13-O-dodecanoateingenol, 3-O-(2'E,4'Z-decadienoyl)-20-O-acetylingenol, 20-O-acetylingenol and 20- deoxyingenol exhibited significant inhibition on NO production with IC50 values of 9.10, 17.38, 1.71, 0.55, 0.57, 12.22, 0.56, 0.30, 11.21 and 2.98 µM, respectively. Furthermore, wilfoside KIN, cynsaccatol L, kanesulone A, and 3ß,7ß,15ß-triacetyloxy-5α-benzoyloxy-2α,8α-dihydroxyjatropha-6(17),11E-diene-9, 14-dione showed cytotoxicity against HepG2 cell line, with IC50 values of 12.55, 12.61, 18.24 and 18.26 µM, respectively. 13-Hydroxyingenol-3-(2,3-dimethylbutanoate)-13- dodecanoate exhibited anti-proliferation activity on MCF-7 cell line with an IC50 value of 17.12 µM. Specifically, euphol selectively inhibited the growth of human glioma stem cells (GSC-3# and GSC-12#), with IC50 values of 8.89 and 13.00 µM, respectively.

Valeridoids G - Q, Eleven seco-Iridoids from Valeriana jatamansi and Their Bioactivites.

Eleven new seco-iridoids, valeridoids G-Q (1-6 and 8-12), along with four known products, 9-epi-valtral C (7), desacylbaldrinal (13), 11-methoxyviburtinal (14) and baldrinal (15), were obtained from Valeriana jatamansi. Among them, the new compounds were identified by their NMR, HR-ESI-MS spectroscopic data and ECD calculation. Moreover, valeridoid N and O were a pair of C3 epimers, whose ether bonds between C-1 and C-3 opened, and new ether bonds formed between C-3 and C-6. Valeridoid Q belonged to the C-1 degradation of seco-iridoids. As a result, 9-epi-valtral C displayed significant inhibition on Streptococcus agalactiae, Staphylococcus aureus, Staphylococcus argenteus, Shigella flexneri and Klebsiella pneumoniae, and valeridoid Q exhibited the most significant inhibition against Salmonella enteritidis. 9-Epi-valtral C and baldrinal selectively inhibited the growth of human glioma stem cells. Valeridoid Q exhibited significant anti-influenza activity, while valeridoid O inhibited nitric oxide production.

Important Role of Estrogen in Distinguishing Depression and Schizophrenia and Prognostic Judgment of MECT.

OBJECTIVES: This study aimed to investigate the role of estrogen in the differential diagnosis of depression and schizophrenia and its relationship with the curative effects, adverse events. METHODS: From 2017 to 2019, patients with depression or schizophrenia treated with modern electroconvulsive therapy (MECT) were studied retrospectively. Their serum estrogen levels, Hamilton Depression Scale, and Brief Psychiatric Rating Scale scores were collected. Differences in the estrogen levels between patients with depression and schizophrenia before and after treatment and the correlation of the estrogen level with curative effect and adverse events was evaluated. In total, 67 patients with depression and 61 with schizophrenia were included. RESULTS: There were no significant differences in the baseline characteristics, except the estrogen level (p < 0.001). Serum estrogen levels increased in both groups after MECT (117 vs. 141 pmol/L, p < 0.001; 42 vs. 46 pmol/L, respectively; p < 0.001), and higher estrogen levels were positively correlated with better outcomes (p < 0.001). CONCLUSION: Post-MECT estrogen levels were not associated with the incidence rate of adverse events of MECT. Estrogen plays a promising role in distinguishing depression and schizophrenia and evaluating the therapeutic efficacy of MECT.

iTRAQ Proteomic Analysis of Interactions Between 20E and Phospholipase C in Apolygus lucorum (Meyer-Dür).

Polyphagous Apolygus lucorum has become the dominant insect in Bacillus thuringiensis (Bt) cotton fields. Hormone 20-hydroxyecdysone (20E) regulates multiple insect development and physiology events. 20E responses are controlled by pathways triggered by phospholipase C (PLC)-associated proteins. However, 20E-modulated genes and related proteins that can be affected by PLC still remain unknown. Here, isobaric tag for relative and absolute quantitation (iTRAQ) and immunoblotting techniques were used to compare differentially expressed proteins (DEPs) in A. lucorum in response to the treatment of 20E and the PLC inhibitor U73122 as well as their combination. A total of 1,624 non-redundant proteins and 97, 248, 266 DEPs were identified in the 20E/control, U73122/control, and 20E + U73122/control groups, respectively. Only 8 DEPs, including pathogenesis-related protein 5-like, cuticle protein 19.8, trans-sialidase, larval cuticle protein A2B-like, cathepsin L1, hemolymph juvenile hormone-binding protein, ATP-dependent RNA helicase p62-like, and myosin-9 isoform X1, were detected in all three groups. Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that the DEPs were involved in diverse signaling pathways. The results were validated by immunoblotting, which highlighted the reliability of proteomics analysis. These findings provided novel insights into the function of PLC in 20E signaling pathway in A. lucorum.

New role of sertraline against Toxoplasma gondii-induced depression-like behaviours in mice.

Toxoplasma gondii (T. gondii) is a neurotropic protozoan parasite, which can cause mental and behavioural disorders. The present study aimed to elucidate the effects and underlying molecular mechanisms of sertraline (SERT) on T. gondii-induced depression-like behaviours. In the present study, a mouse model and a microglial cell line (BV2 cells) model were established by infecting with the T. gondii RH strain. In in vivo and in vitro experiments, the underlying molecular mechanisms of SERT in inhibiting depression-like behaviours and cellular perturbations caused by T. gondii infection were investigated in the mouse brain and BV2 cells. The administration of SERT significantly ameliorated depression-like behaviours in T. gondii-infected mice. Furthermore, SERT inhibited T. gondii proliferation. Treatment with SERT significantly inhibited the activation of microglia and decreased levels of pro-inflammatory cytokines such as tumour necrosis factor-alpha, and interferon-gamma, by down-regulating tumour necrosis factor receptor 1/nuclear factor-kappa B signalling pathway, thereby ameliorating the depression-like behaviours induced by T. gondii infection. Our study provides insight into the underlying molecular mechanisms of the newly discovered role of SERT against T. gondii-induced depression-like behaviours.

Resveratrol modulates Toxoplasma gondii infection induced liver injury by intervening in the HMGB1/TLR4/NF-κB signaling pathway.

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite that can cause liver diseases in the host, including hepatitis and hepatomegaly. High mobility group box 1 (HMGB1) is the main inflammatory mediator causing cell injury or necrosis. HMGB1 binds to toll like receptor 4 (TLR4), then activates the nuclear factor-κB (NF-κB) signaling pathway, which promotes the release of inflammatory factors. Our previous studies showed that HMGB1 mediated TLR4/NF-κB signaling pathway plays an important role in liver injury induced by T. gondii infection. Resveratrol (RSV) is a small polyphenol, which has anti-inflammatory, anti-cancer, anti-T. gondii effect. However, the effect of RSV on liver injury caused by T. gondii infection is unclear. This study used the RH strain tachyzoites of T. gondii to infect murine liver line, NCTC-1469 cells to establish an in vitro model and acute infection of mice for the in vivo model to explore the protective effect of RSV on liver injury induced by T. gondii infection. The results showed that RSV inhibited the proliferation of T. gondii in the liver, reduced the alanine aminotransferase/aspartate aminotransferase levels and pathological liver damage. Additionally, RSV inhibited the production of tumor necrosis factor-α, inducible nitric oxide synthase and HMGB1 by interfering with the TLR4/NF-κB signaling pathway. These results indicate that RSV can protect liver injury caused by T. gondii infection by intervening in the HMGB1/TLR4/NF-κB signaling pathway. This study will provide a theoretical basis for RSV treatment of T. gondii infection induced liver injury.

TRPC5 mediates TMZ resistance in TMZ-resistant glioblastoma cells via NFATc3-P-gp pathway.

P-glycoprotein (P-gp) acts as a pump to transport cytotoxic drugs out of cells and is upregulated in cancer cells. Suppressing the expression of P-gp is an effective strategy to overcome multidrug resistance in cancer chemotherapy. Temozolomide (TMZ) is the recommended drug for the standard treatment of patients with glioblastoma, but its clinical application is restricted due to drug resistance. Transient receptor potential channel-5 (TRPC5), a Ca2+-permeable channel, has been attributed to a different drug resistance mechanism except DNA repair system; therefore, we aimed to elucidate the mechanism regarding the role of TRPC5 in TMZ resistance. TRPC5 and P-glycoprotein (P-gp) are upregulated in TMZ-resistant glioblastoma cell lines. The downregulation of TRPC5 inhibited P-gp expression and led to a significant reversal of TMZ resistance in TMZ-resistant cell lines. TRPC5-siRNA restricted the growth of tumour xenografts in an athymic nude mouse model of TMZ-resistant cells. In specimens from patients with recurrent glioblastoma, TRPC5 was found to be highly expressed, accompanied by the upregulation of P-gp expression. The nuclear factor of activated T cell isoform c3 (NFATc3), which acts as a transcriptional factor, bridges TRPC5 activity to P-gp induction. In conclusion, these results demonstrate the functional role of the TRPC5-NFATc3-P-gp signalling pathway in TMZ resistance in glioblastoma cells.

Iridoids from Valeriana jatamansi with anti-inflammatory and antiproliferative properties.

Seven undescribed (valejatadoids A-G) and 26 known iridoids were obtained from the roots and rhizomes of Valeriana jatamansi. Their structures were determined based on extensive spectroscopic data, especially 1D and 2D NMR, along with HRESIMS. Valejatadoid B is a monoene-type iridoid with a unique double bond between C-4 and C-5. Valejatadoids D-G, jatamanin U, jatamanin O, jatamanvaltrate E, valeriotetrate C, IVHD-valtrate, 10-isovaleroxy-valtrathydrin, jatamanvaltrate Q, valeriandoid F, jatamanvaltrate K, jatamanvaltrate W and isovaltrate were more potent than the positive control when evaluated for inhibition of NO production. Among them, valeriandoid F and jatamanvaltrate K exhibited the most significant inhibitory effects with IC50 values of 0.88 and 0.62 µM, respectively. In addition, valeriandoid F selectively inhibited the proliferation of human glioma stem cell lines, GSC-3# and GSC-18#, with IC50 values of 7.16 and 5.75 µM, respectively.

Structures/cytotoxicity/selectivity relationship of natural steroidal saponins against GSCs and primary mechanism of tribulosaponin A.

Glioblastoma multiform (GBM) is the highly aggressive brain tumor with poor prognosis. Glioma stem cells (GSCs), small population of cancer cells that exist in GBM tissues, resistant to chemotherapy and radiotherapy and usually driving GBM recurrence, have been developed as effective therapeutic target. Steroidal saponins are one of important resources for anti-tumor agent and may be benefited to selectively clear GSCs. In this report, total of 97 natural steroidal saponins were investigated the relationship among structures/cytotoxicity/selectivity against GSCs, glioma cell lines and human untransformed cells, and revealed that tribulosaponin A was the most potent compound. Further investigation suggested that tribulosaponin A up-regulated the expression of NCF1 and NOX1 to accumulate ROS for triggering apoptosis in GSCs, but not in untransformed cells, and it was further supported by the assay that N-acetyl-l-cysteine (NAC) clearing ROS delayed GSCs apoptosis. Besides, tribulosaponin A damaged GSCs recapturing tumor spheres formation.

MeCP2 inactivation of LncRNA GAS5 triggers cardiac fibroblasts activation in cardiac fibrosis.

Long non coding RNA growth arrest-specific transcript 5 (LncRNA GAS5) participate in the formation of fibrosis diseases. However, the key role of LncRNA GAS5 in the development of cardiac fibrosis remains unclear. Accumulating evidence suggests that DNA methylation alterations play a central role in cardiac fibroblast activation. In this study, we explored MeCP2 inactivation of LncRNA GAS5 leads to down regulation of LncRNA GAS5 expression in cardiac fibrosis. Gain and loss function of LncRNA GAS5 and MeCP2 was analyzed. The expression of LncRNA GAS5 was significantly decreased in cardiac fibrosis tissues, while MeCP2 was significantly increased. Moreover, the expression of MeCP2 was increased in TGF-ß1 induced cardiac fibroblasts, while the expression of LncRNA GAS5 was decreased. Down regulation of LncRNA GAS5 resulted in increasing cellular proliferation. In contrast, exogenous over expression of LncRNA GAS5 in cardiac fibroblasts inhibited cell proliferation. 5-AzadC or knockdown of MeCP2 treatment significantly restored LncRNA GAS5 expression in cardiac fibroblasts, while over expression of MeCP2 treatment significantly inhibited LncRNA GAS5 expression in cardiac fibroblasts. In summary, these results suggested that MeCP2 silencing of LncRNA GAS5 triggers cardiac fibroblasts activation in cardiac fibrosis.

Antidepressive Effect of Arctiin by Attenuating Neuroinflammation via HMGB1/TLR4- and TNF-α/TNFR1-Mediated NF-κB Activation.

Inflammation is a potential factor in the pathophysiology of depression. A traditional Chinese herbal medicine, arctiin, and its aglycone, arctigenin, are the major bioactive components in Fructus arctii and exhibit neuroprotective and anti-inflammatory activities. Arctigenin has been reported to have antidepressant-like effects. However, the antidepressant-like effects of arctiin, its precursor, remain unknown. In this study, we investigated the antidepressant-like effects of arctiin and its underlying mechanisms by in vivo and in vitro experiments in mice. Our results showed that arctiin significantly attenuated sucrose consumption and increased the immobility time in tail suspension and forced swimming tests. Arctiin decreased neuronal damage in the prefrontal cortex (PFC) of the brain. Arctiin also attenuated the levels of three inflammatory mediators, indoleamine 2,3-dioxygenase, 5-hydroxytryptamine, and dopamine, that were elevated in the PFC or serum of chronic unpredictable mild stress (CUMS)-exposed mice. Arctiin reduced excessive activation of microglia and neuroinflammation by reducing high mobility group box 1 (HMGB1)/toll-like receptor 4 (TLR4)- and tumor necrosis factor-α (TNF-α)/TNF receptor 1 (TNFR1)-mediated nuclear factor-kappa B (NF-κB) activation in the PFC of CUMS-exposed mice and HMGB1- or TNF-α-stimulated primary cultured microglia. These findings demonstrate that arctiin ameliorates depression by inhibiting the activation of microglia and inflammation via the HMGB1/TLR4 and TNF-α/TNFR1 signaling pathways.

Iridoids and bis-iridoids from Valeriana jatamansi and their cytotoxicity against human glioma stem cells.

An undescribed iridoid (valeridoid A) and five undescribed bis-iridoids (valeridoids B-F), along with four known ones, were isolated from the roots and rhizomes of Valeriana jatamansi. Their structures were elucidated based on 1D and 2D NMR, as well as HRESIMS spectroscopic data. In addition, 8,9-didehydro-7-hydroxydolichodial and valeridoid F were found to inhibit the growth of three human glioma stem cells (GSC-3#, GSC-12# and GSC-18#).

A natural compound obtained from Valeriana jatamansi selectively inhibits glioma stem cells.

Glioblastoma is one of the most malignant tumors with very poor prognosis. Glioma stem cells (GSCs) occupy a small proportion in glioma, but they are closely associated with radiotherapy and chemotherapy resistance, promoting tumor angiogenesis, hypoxia response, invasion and recurrence. Therefore, GSCs have become a new target for tumor treatment and are used in drug screening. Rupesin E is a natural compound obtained from Valeriana jatamansi, and its antitumor activity has not been reported. In the present study, the antitumor activity of rupesin E was investigated, and the results demonstrated that it inhibited the proliferation of GSCs (GSC-3#, GSC-12#, GSC-18#) with the IC50 values of 7.13±1.41, 13.51±1.46 and 4.44±0.22 µg/ml, respectively. In addition, immunofluorescence cell staining and flow cytometry techniques demonstrated that rupesin E inhibited GSC proliferation and induced apoptosis. Furthermore, rupesin E inhibited the ability of GSC colony formation, indicating its antitumor activity against GSCs in vitro.

Arctigenin ameliorates depression-like behaviors in Toxoplasma gondii-infected intermediate hosts via the TLR4/NF-κB and TNFR1/NF-κB signaling pathways.

Toxoplasma gondii (T. gondii) is a known neurotropic protozoan that remains in the central nervous system and induces neuropsychiatric diseases in intermediate hosts. Arctigenin (AG) is one of the major bioactive lignans of the fruit Arctium lappa L. and has a broad spectrum of pharmacological activities such as neuroprotective, anti-inflammatory and anti-T. gondii effects. However, the effect of AG against depressive behaviors observed in T. gondii-infected hosts has not yet been clarified. In the present study, we analyzed the effects of AG against T. gondii-induced depressive behaviors in intermediate hosts using a microglia cell line (BV2 cells) and brain tissues of BALB/c mice during the acute phase of infection with the RH strain of T. gondii. AG attenuated microglial activation and neuroinflammation via the Toll-like receptor/nuclear factor-kappa B (NF-κB) and tumor necrosis factor receptor 1/NF-κB signaling pathways, followed by up-regulating the dopamine and 5-hydroxytryptamine levels and inhibiting the depression-like behaviors of hosts. AG also significantly decreased the T. gondii burden in mouse brain tissues. In conclusion, we elucidated the effects and underlying molecular mechanisms of AG against depressive behaviors induced by T. gondii infection.

Identification of two mitochondrial-targeting cyclometalated iridium(III) complexes as potent anti-glioma stem cells agents.

Glioma stem cells (GSCs) are thought to be responsible for the recurrence and invasion of glioblastoma multiform (GBM), which have been evaluated and exploited as the therapeutic target for GBM. Cyclometalated iridium(III) complexes have been demonstrated as the potential anticancer agents, however, their antitumor efficacies against GSCs are still unknown. Herein, we investigated the antitumor activity of two cyclometalated iridium(III) complexes [Ir(ppy)2L](PF6) (Ir1) and [Ir(thpy)2L](PF6) (Ir2) (ppy = 2-phenylpyridine, thpy = 2-(2-thienyl)pyridine and L = 4,4'-Bis(hydroxymethyl)-2,2'-bipyridine) against GSCs. The results clearly indicate that Ir1 and Ir2 kill GSCs selectively with IC50 values ranging from 5.26-9.05 µM. Further mechanism research display that Ir1 and Ir2 can suppress the proliferation of GSCs, penetrate into GSCs efficiently, localize to mitochondria, and induce mitochondria-mediated apoptosis, including the loss of mitochondrial membrane (MMP), elevation of intracellular reactive oxygen species (ROS) and caspases activation. Moreover, Ir1 and Ir2 can destroy the GSCs self-renewal and unlimited proliferation capacity by affecting the GSCs colony formation. According our knowledge, this is the first study to investigate the anti-GSCs properties of cyclometalated iridium(III) complexes.

New aporphine alkaloids with selective cytotoxicity against glioma stem cells from Thalictrum foetidum.

Seven new isoquinoline alkaloids, 9-(2'-formyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy dehydroaporphine (1), 9-(2'-formyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy oxoaporphine (2), 3-methoxy-2'-formyl oxohernandalin (3), (-)-9-(2'-methoxycarbonyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy aporphine (4), (-)-2'-methoxycarbonyl thaliadin (5), (-)-9-(2'-methoxyethyl-5', 6'-dimethoxyphenoxy)-1, 2, 3, 10-tetramethoxy aporphine (6), (-)-3-methoxy hydroxyhernandalinol (7), together with six known isoquinoline alkaloids (8-13) were isolated from the roots of Thalictrum foetidum. Their structures were elucidated by extensive spectroscopic measurements. Compounds 1 and 2 showed significant selective cytotoxicity against glioma stem cells (GSC-3# and GSC-18#) with IC50 values ranging from 2.36 to 5.37 µg·mL-1.

TRPC5­induced autophagy promotes the TMZ­resistance of glioma cells via the CAMMKß/AMPKα/mTOR pathway.

Temozolomide (TMZ) is the first choice chemotherapy agent against glioblastoma, but the TMZ chemotherapy resistance has restricted the clinical application. Although autophagy is considered an adaptive response for cell survival under the pressure of chemotherapy and associated with chemotherapy resistance, its initiator and the precise molecular mechanism remains unknown. In the present study, it was determined that TMZ increases the transient receptor potential cation channel subfamily C member 5 (TRPC5) protein expression and the basal autophagy level, and the upregulation of autophagy is mediated by TRPC5 in glioma cells. Additionally, knockdown of TRPC5 upregulated the chemotherapy sensitivity in vitro and in vivo. Furthermore, TRPC5­small interfering RNA and pharmacological inhibition indicated that the Ca2+/calmodulin dependent protein kinase ß (CaMKKß)/AMP­activated protein kinase α (AMPKα)/mechanistic target of rapamycin kinase (mTOR) pathway mediates cell survival autophagy during TMZ treatment. In addition, TMZ­resistant U87/TMZ cells retained a high basal autophagy level, while silence of TRPC5 expression or inhibition of autophagy reversed TMZ resistance. Thus, the present study revealed that TRPC5, an initiator of autophagy, upregulated TMZ resistance via the CaMKKß/AMPKα/mTOR pathway and this indicated a novel therapeutic site for drug resistance in glioma chemotherapy.

Bioactive 3,8-Epoxy Iridoids from Valeriana jatamansi.

Twelve 3,8-epoxy iridoids, including four new compounds, jatamanins R-U (1-4), and eight known compounds (5-12), were obtained from the roots and rhizomes of Valeriana jatamansi. The structures were elucidated from analysis of spectroscopic data. The absolute configurations of 1-4 were determined by comparison of experimental and literature ECD spectra. Moreover, the compounds were evaluated for cytotoxic effects against glioma stem cells, inhibition of NO production, activity against influenza A virus and reversal of multidrug resistance of HepG2/ADR cells. Compounds 9 and 12 showed significant cytotoxic potency against GSC-18# (IC50 =1.351 and 4.439 µg ml-1 , respectively) and GSC-3# (IC50 =10.88 and 6.348 µg ml-1 , respectively) glioma stem cells, while compound 12 was also slightly less potent against GSC-12# (IC50 =13.45 µg ml-1 ) glioma stem cell growth. In addition, compounds 9 and 12 displayed obvious inhibition of NO production (IC50 =4.6 and 15.8 µm, respectively).