Phospho-extracellular Signal-regulated Kinase Research Articles

Apelin-13 protects the heart against ischemia-reperfusion injury through the RISK-GSK-3β-mPTP pathway.

IntroductionApelin plays an important role in the protection against myocardial ischemia-reperfusion (I/R) injury, while the mechanism still remains unclear. In the current study, we aimed to evaluate the protective effect of apelin-13, and the main mechanism.Material and methodsThe in vivo I/R injury model (Sprague-Dawley rat) was established, then infarct size, expression levels of phospho-protein kinase B (p-Akt), phospho-extracellular signal-regulated kinase (p-ERK) and phospho-glycogen synthase kinase-3β (p-GSK-3β) were measured. The fluorescence intensity of tetramethylrhodamine ethyl ester perchlorate (TMRE) of the isolated myocardial cells was determined to evaluate the opening of the mitochondrial permeability transition pore (mPTP) caused by oxidant stress and hypoxia/reoxygenation.ResultsFor the established I/R injury model, apelin-13 and SB216763 (GSK-3β inhibitor) significantly reduced the infarct size (p < 0.05), which could be abolished by LY294002 (PI3K inhibitor), PD98059 (MEK inhibitor) and atractyloside (mPTP accelerator). The enhanced expression levels of p-Akt, p-ERK and p-GSK-3β caused by apelin-13 (p < 0.05) could be counteracted by LY294002 and PD98059. The reduced fluorescence intensity of TMRE in the H2O2/apelin-13 and H2O2/SB216763 treated groups was significantly lower (p < 0.05), indicating that apelin-13 and SB216763 could reduce the decline in mitochondrial membrane potential caused by oxidant stress, and the fluorescence intensity in the hypoxia/reoxygenation + apelin-13 group was significantly lower (p < 0.05), which suggested that apelin-13 could inhibit the mitochondrial membrane potential changes induced by hypoxia/reoxygenation.ConclusionsThe protective mechanism of apelin-13 might be that inactivation of GSK-3β could inhibit the opening of mPTP by activating PI3K/Akt and ERK1/2 involved in the reperfusion injury salvage kinase (RISK) pathway.

Hesperidin, A Popular Antioxidant Inhibits Melanogenesis via Erk1/2 Mediated MITF Degradation.

Regulation of melanogenesis has been the focus of treatment for hyperpigmentary skin disorders. Although hesperidin is one of the most well-known, naturally occurring flavonoids with antioxidant and anti-inflammatory effect, its anti-melanogenic effect is not known. The present study aims to determine the anti-melanogenic effect of hespiridin as well as its underlying molecular mechanisms. Melanin contents were measured in normal human melanocytes and B16F10 melanoma cells. Protein and mRNA levels of tyrosinase, microphthalmia-associated transcription factor (MITF), tyrosinase related protein-1 (TRP-1) and TRP-2 were determined. Melanogenesis-regulating signals were examined. In results, hesperidin strongly inhibited melanin synthesis and tyrosinase activity. Hesperidin decreased tyrosinase, TRP-1, and TRP-2 protein expression but increased phospho-extracellular signal-regulated kinase 1/2 (p-Erk1/2) expression. Specific inhibitor of Erk1/2 or proteasome inhibitor reversed the inhibition of melanogenesis induced by hesperidin. Taken together, hesperidin, a popular antioxidant, stimulated Erk1/2 phosphorylation which subsequently degraded MITF which resulted in suppression of melanogenic enzymes and melanin synthesis.

Abstract 1900: Mechanistic study of aspirin, folic acid and calcium (AFAC) combinations delivered using targeted polymeric nanoparticles in colon cancer prevention

Abstract Colorectal cancer (CRC) is the third most common cause of cancer death in the US, accounting for ∼51,000 deaths each year. Although the prognosis of this disease is improving due to better treatment options, attention has focused on the chemoprevention of this disease rather than on diagnosis and treatment. The objective of the present study was to evaluate the mechanisms of action of orally administered, colon targeted chemopreventive regimens aspirin (ASP), folic acid (FA) and calcium (Ca) alone and in combination AFAC (ASP+FA+Ca) in in-vitro and in-vivo rat model. We used colon cancer cells, HCT-116 and HT-29 as the in-vitro model. For colon targeting, ASP and FA was encapsulated in polylactide-co-glycolide (PLGA 50:50) polymer nanoparticles. Our previous studies demonstrated that combination of ASP (1mM), FA (1.5mM) and Ca (1.5mM) showed synergistic effect on inhibition of colon cancer cell viability. Follow-up study on azoxymethane (AOM) induced colon cancer in rats showed that the low (40+3.2+65 mg/kg), medium (80+6.4+130 mg/kg) and high dose (133+11+216 mg/kg) of modified AFAC-PLGA nanoparticle chemopreventive regimens demonstrated 1.7 to 2.0 fold reduction in the number of aberrant crypt foci (ACF). In continuation, a mechanistic approach was evaluated whereby colon cancer cells HCT-116 and HT-29 were treated with unmodified AFAC for 6h to determine gene expression using RT-qPCR analysis, and treated for 24h for protein expression study using western blot. The results obtained from the in-vitro study were further validated on rat colon tissue treated AFAC-PLGA nanoparticles, using immunohistochemistry. The RT-qPCR analysis showed that AFAC promoted reduction in cell viability was associated with down-regulation of proliferation genes (PCNA, and MKI67), cell cycle genes (CCND1, RB1, CDK4, E2F1, and JUN), and up-regulation of anti-apoptotic p21 gene. The protein expression studies revealed that AFAC treatment inhibited phospho-extracellular signal-regulated kinase 1/2 (p-ERK1/2), and phospho-p38 MAPK protein levels. The AFAC treatment also inhibited protein expression of PCNA, MKI67 and p-RB1 compared to control and individual drug treatment. Immunohistochemistry study using rat colon tissues revealed that the low, medium and high dose of AFAC-PLGA nanoparticles showed significant reduction in cell proliferation at 10.6%, 26.5%, and 48.5% as evidenced by PCNA protein expression. The AFAC treatment significantly increased apoptosis as evaluated by Tunnel assay, as well as decreased p-ERK1/2 and p-RB1 index. Overall, our results illustrate the mechanisms of action which confirms anti-proliferative activity of AFAC-PLGA nanoparticles, thus confirming the importance of novel combination chemoprevention strategies against colon cancer. Citation Format: Arvind Thakkar, Sushma Chenreddy, Jeffrey Wang, Sunil Prabhu. Mechanistic study of aspirin, folic acid and calcium (AFAC) combinations delivered using targeted polymeric nanoparticles in colon cancer prevention. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 1900. doi:10.1158/1538-7445.AM2015-1900

Assessment of Protective Role of Multifunctional Dopamine Agonist D-512 Against Oxidative Stress Produced by Depletion of Glutathione in PC12 Cells: Implication in Neuroprotective Therapy for Parkinson's Disease.

Oxidative stress has been strongly implicated in the progression of Parkinson's disease (PD). Depletion of cytoplasmic glutathione levels is one of the indications of oxidative stress, which occur in the substantia nigra of PD patients at an early stage of the disease process. It has been shown that glutathione depletion causes the inhibition of mitochondrial complex I, thus affecting mitochondrial function leading to oxidative stress via production of reactive oxygen species. Studies were carried out to investigate the role of D-512, a potent multifunctional neuroprotective D2/D3 receptor agonist, in protecting dopaminergic PC12 cells treated with buthionine sulfoximine (BSO), an inhibitor of key enzyme in glutathione synthesis and 6-hydroxydopamine (6-OHDA), a widely used neurotoxin. D-512 was able to restore level of glutathione against BSO/6-OHDA-mediated glutathione depletion. D-512 also showed significant neuroprotection in PC12 cells against toxicity induced by combined treatment of BSO and 6-OHDA. Furthermore, D-512 was able to restore both phospho-extracellular signal-regulated kinase and phospho-Jun N-terminal kinase levels upon treatment with 6-OHDA providing an evidence on the possible mechanism of action for neuroprotection by modulating mitogen-activated protein kinases. We have further demonstrated the neuroprotective effects of D-512 against oxidative insult produced by BSO and 6-OHDA in PC12 cells.

Anti-tumor peptide AP25 decreases cyclin D1 expression and inhibits MGC-803 proliferation via phospho-extracellular signal-regulated kinase-, Src-, c-Jun N-terminal kinase- and phosphoinositide 3-kinase-associated pathways.

The anti-tumor peptide AP25 is a prototype integrin antagonist, which exhibits anti‑angiogenic and anti‑tumor activity. The molecular mechanisms by which AP25 inhibits the growth of the MGC‑803 gastric carcinoma cell line were investigated in the present study. K‑ras specific RNA interference by lentiviral infection was successfully induced in MGC‑803 cells [MGC‑803 short hairpin (sh)RNA group] and the expression levels of K‑ras, phosphorylated extracellular signal‑regulated kinase (p-ERK) and cyclin D1 were observed to be markedly decreased. By contrast, AP25 caused cell cycle arrest of intact MGC‑803 cells and decreased p‑ERK and cyclin D1 expression levels. Of note, 0.4‑3.2 µM AP25 no longer inhibited MGC‑803 shRNA growth, indicating that AP25, at such concentrations, exerts its effect mainly through the Ras/Raf/mitogen-activated protein kinase kinase/ERK pathway, whereas at 25 µM, AP25 was able to inhibit MGC‑803 shRNA growth. Chemical inhibitors of Src, c‑Jun N‑terminal kinase (JNK) and phosphoinositide 3‑kinase (PI3K) were used to confirm that 25 µM AP25 inhibited growth of cells in the MGC‑803 shRNA group and activated intracellular signaling pathways with Src, JNK and PI3K as key enzymes. In conclusion, the present study revealed the signal transduction pathways activated by AP25 at low (0.4‑3.2 µM) or high (25 µM) concentrations. It also confirmed that integrins, when interacting with the freely moving ligand AP25 instead of immobilized extracellular matrix glycoproteins, are able to initiate cell signaling via similar pathways as in the latter case but with a reversed effect, to inhibit cell growth.

Antioxidant's cytoprotective effects on rotator cuff tenofibroblasts exposed to aminoamide local anesthetics.

Local anesthetics (LA) are among the drugs most frequently used for musculoskeletal problems, in procedures ranging from diagnosis to postoperative pain control. The cytotoxicity of LA is an emerging area of concern. The purpose of this study was to determine whether cyanidin, an antioxidant, exerts cytoprotective effects against tenofibroblast death induced by LA. Primary cultured human rotator cuff tenofibroblasts were used to evaluate the cytotoxicity of these LA: Ropivacaine (0.075%), Bupivacaine (0.05%), and Lidocaine (0.2%). The effects of cyanidin (100 μg/ml) on the cytotoxicity induced by these LA were investigated. Cell viability, ROS production, caspase-3/7 activity, and expressions of phospho-extracellular signal-regulated kinases (ERK), phospho-p38, phospho-c-Jun N-terminal kinase (JNK), and cleaved PARP-1 were evaluated. Exposure to LA significantly induced cell death (p < 0.001), ROS production (p ≤ 0.04), the activation of caspase-3/7 (p < 0.001), and the increased expressions of phospho-ERK, phospho-p38, phospho-JNK, and cleaved PARP-1. These LA-induced cytotoxic effects were reduced by cyanidin. These data indicate that cyanidin, an antioxidant, has cytoprotective effects against LA-induced cytotoxicity to rotator cuff tenofibroblasts.

Tanshinone IIA attenuates interleukin-17A-induced systemic sclerosis patient-derived dermal vascular smooth muscle cell activation via inhibition of the extracellular signal-regulated kinase signaling pathway

OBJECTIVE:Salvia miltiorrhiza has long been used to treat systemic sclerosis. Tanshinone IIA, one of the phytochemicals derived from the roots of Salvia miltiorrhiza, exhibits multiple biological activities. The present study aimed to investigate whether tanshinone IIA has an effect on the interleukin-17A-induced functional activation of systemic sclerosis patient-derived dermal vascular smooth muscle cells.METHODS:Systemic sclerosis patient-derived dermal vascular smooth muscle cells were incubated with various dosages of tanshinone IIA in the presence of interleukin-17A or the serum of systemic sclerosis patients. Cell proliferation was assessed using Cell Counting Kit-8. The expression of collagen 1 and 3 in cells was evaluated by immunofluorescence. Cell migration was measured using a transwell assay. The expression of phospho-extracellular signal-regulated kinase was detected by Western blotting.RESULTS:Our data demonstrate that tanshinone IIA exerts an inhibitory effect on interleukin-17A-induced systemic sclerosis patient-derived dermal vascular smooth muscle cell proliferation, collagen synthesis and migration.CONCLUSION:These findings suggest that tanshinone IIA might serve as a promising therapeutic agent for the treatment of systemic sclerosis.

Sp1 and c-Myc modulate drug resistance of leukemia stem cells by regulating survivin expression through the ERK-MSK MAPK signaling pathway.

BackgroundAcute myeloid leukemia (AML) is initiated and maintained by a subset of self-renewing leukemia stem cells (LSCs), which contribute to the progression, recurrence and therapeutic resistance of leukemia. However, the mechanisms underlying the maintenance of LSCs drug resistance have not been fully defined. In this study, we attempted to elucidate the mechanisms of LSCs drug resistance.MethodsWe performed reverse phase protein arrays to analyze the expression of anti-apoptotic proteins in the LSC-enriched leukemia cell line KG-1a. Immuno-blotting, cell viability and clinical AML samples were evaluated to verify the micro-assay results. The characteristics and transcriptional regulation of survivin were analyzed with the relative luciferase reporter assay, mutant constructs, chromatin immuno-precipitation (ChIP), quantitative real-time reverse transcription polymerase chain reaction (RT-qPCR), and western blotting. The levels of Sp1, c-Myc, phospho-extracellular signal-regulated kinase (p-ERK), phospho-mitogen and stress-activated protein kinase (p-MSK) were investigated in paired CD34+ and CD34- AML patient samples.ResultsSurvivin was highly over-expressed in CD34 + CD38- KG-1a cells and paired CD34+ AML patients compared with their differentiated counterparts. Functionally, survivin contributes to the drug resistance of LSCs, and Sp1 and c-Myc concurrently regulate levels of survivin transcription. Clinically, Sp1 and c-Myc were significantly up-regulated and positively correlated with survivin in CD34+ AML patients. Moreover, Sp1 and c-Myc were further activated by the ERK/MSK mitogen-activated protein kinase (MAPK) signaling pathway, modulating survivin levels.ConclusionOur findings demonstrated that ERK/MSK/Sp1/c-Myc axis functioned as a critical regulator of survivin expression in LSCs, offering a potential new therapeutic strategy for LSCs therapy.Electronic supplementary materialThe online version of this article (doi:10.1186/s12943-015-0326-0) contains supplementary material, which is available to authorized users.

Dermatophytes activate skin keratinocytes via mitogen-activated protein kinase signaling and induce immune responses.

Dermatophytes cause superficial and cutaneous fungal infections in immunocompetent hosts and invasive disease in immunocompromised hosts. However, the host mechanisms that regulate innate immune responses against these fungi are largely unknown. Here, we utilized commercially available epidermal tissues and primary keratinocytes to assess (i) damage induction by anthropophilic, geophilic, and zoophilic dermatophyte strains and (ii) the keratinocyte signaling pathways, transcription factors, and proinflammatory responses induced by a representative dermatophyte, Trichophyton equinum. Initially, five dermatophyte species were tested for their ability to invade, cause tissue damage, and induce cytokines, with Microsporum gypseum inducing the greatest level of damage and cytokine release. Using T. equinum as a representative dermatophyte, we found that the mitogen-activated protein kinase (MAPK) pathways were predominantly affected, with increased levels of phospho-p38 and phospho-Jun N-terminal protein kinase (JNK) but decreased levels of phospho-extracellular signal-regulated kinases 1 and 2 (ERK1/2). Notably, the NF-κB and PI3K pathways were largely unaffected. T. equinum also significantly increased expression of the AP-1-associated transcription factor, c-Fos, and the MAPK regulatory phosphatase, MKP1. Importantly, the ability of T. equinum to invade, cause tissue damage, activate signaling and transcription factors, and induce proinflammatory responses correlated with germination, indicating that germination may be important for dermatophyte virulence and host immune activation.

Influence of caffeine and hyaluronic acid on collagen biosynthesis in human skin fibroblasts.

AimThe aim of this study was to evaluate the effect of caffeine on collagen biosynthesis in human skin fibroblasts and the influence of hyaluronic acid (HA) on this process.Materials and methodsCollagen, [3H]-thymidine incorporation, and prolidase activity were measured in confluent human skin fibroblast cultures that had been treated with 1, 2, and 5 mM caffeine and with caffeine and 500 μg/mL HA. Western immunoblot analysis was performed to evaluate expression of β1-integrin receptor, insulin-like growth factor receptor phospho-Akt protein and mitogen-activated protein kinase (phospho-extracellular signal-regulated kinase).ResultsCaffeine inhibited collagen biosynthesis in a dose-dependent manner. The mechanism of this process was found at the level of prolidase activity. Caffeine significantly inhibited the enzyme activity. The addition of HA had no effect on collagen biosynthesis or prolidase activity in fibroblasts incubated with caffeine. Caffeine also had an inhibitory effect on DNA biosynthesis. HA, however, did not have any significant effect on this process. The inhibition of the expression of β1-integrin and insulin-like growth factor receptor in fibroblasts incubated with the caffeine indicates a possible mechanism of inhibition of collagen biosynthesis.ConclusionCaffeine reduces collagen synthesis in human cultured skin fibroblasts. HA did not have any significant protective effect on this process. This is the first study to our knowledge that reports caffeine-induced inhibition of collagen synthesis in human skin fibroblasts.

Rubus coreanus Miquel ameliorates scopolamine-induced memory impairments in ICR mice.

The present study investigated the effect of Rubus coreanus Miquel (RCM) on scopolamine-induced memory impairments in ICR mice. Mice were orally administrated RCM for 4 weeks and scopolamine was intraperitoneally injected into mice to induce memory impairment. RCM improved the scopolamine-induced memory impairment in mice. The increase of acetylcholinesterase activity caused by scopolamine was significantly attenuated by RCM treatment. RCM increased the levels of acetylcholine in the brain and serum of mice. The expression of choline acetyltransferase, phospho-cyclic AMP response element-binding protein, and phospho-extracellular signal-regulated kinase was significantly increased within the brain of mice treated with RCM. The brain antioxidant enzyme activity decreased by scopolamine was increased by RCM. These results demonstrate that RCM exerts a memory-enhancing effect via the improvement of cholinergic function and the potentiated antioxidant activity in memory-impaired mice. The results suggest that RCM may be a useful agent for improving memory impairment.

Combined effect of nerve growth factor and brain‑derived neurotrophic factor on neuronal differentiation of neural stem cells and the potential molecular mechanisms.

Neural stem cells (NSCs) are important pluripotent stem cells, which have potential applications in cell replacement therapy. Brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) have been demonstrated to exert a marked impact on the proliferation and differentiation of NSCs. The effects of NGF, BDNF, and BDNF combined with NGF on NSC neuronal differentiation and the possible mechanisms for these effects were investigated in this study. An adherent monolayer culture was employed to obtain highly homogeneous NSCs. The cells were divided into four groups: Control, NGF, BDNF and combination (BDNF + NGF) groups. Neuron differentiation was examined using immunocytochemistry and phospho-extracellular signal-regulated kinase (p-ERK) levels were analyzed using western blotting. Reverse transcription polymerase chain reaction was used to measure the mRNA expression levels of the HES1, HES5, MASH1, NGN1 and NeuroD transcription factors at different time intervals following neurotrophin-induced differentiation. NGF and BDNF were observed to induce NSC neuronal differentiation, and β-tubulin III-positive cells and p-ERK expression levels were highest in the NGF + BDNF combination group at all time points. The proportion of β-tubulin III-positive neurons in each group was associated with the expression levels of MASH1, NGN1 and NeuroD in the group. In conclusion, BDNF combined with NGF significantly improved NSC neuronal differentiation, which may provide support for the practical application of NSCs in neurodegenerative diseases.

Melatonin enhances adult rat hippocampal progenitor cell proliferation via ERK signaling pathway through melatonin receptor

Melatonin, a neurohormone secreted mainly by the pineal gland, has a variety of physiological functions and neuroprotective effects. Previous studies have shown that melatonin could stimulate the proliferation of neural stem/progenitor cells (NS/PCs). Recent studies reported that the activities of mitogen-activated protein kinase (MAPK) of neural stem cells (NSCs) changed in response to the proliferative effect of melatonin. Therefore, the aim of the present study was to explore the proliferative mechanism mediated by melatonin on the adult rat hippocampal NS/PCs. Treatment with melatonin significantly increased the number of neurospheres in a concentration-dependent manner and up-regulated nestin protein. Pretreatment with luzindole, a melatonin receptor antagonist, and PD98059, a mitogen-activated protein kinase kinase (MEK) inhibitor, prevented the increase in the number of neurospheres formed by the activation of melatonin. The levels of phospho-c-Raf and phospho-extracellular signal-regulated kinase 1/2 (ERK1/2) increased when treated with melatonin. Pretreatment with luzindole or PD98059 prevented the melatonin-induced increase in these signaling molecules. The present results showed that melatonin could induce NS/PCs to proliferate by increasing phosphorylation of ERK1/2 and c-Raf through melatonin receptor. These results provide further evidence for a role of melatonin in promoting neurogenesis, adding to the remarkably pleiotropic nature of this neurohormone. This intrinsic modulator deserves further investigation to better understand its physiological and therapeutic implication.

Effect of millimeter wave for differentiation of bone marrow stromal cells to osteoblasts-like cell

In this study, we have evaluated the effects of millimeter wave by assessing the osteogenic differentiation properties of bone marrow mesenchymal stem cells (BM-MSCs). To measure the effect of millimeter wave, millimeter wave irradiation was applied to these cells continuously for 7 days and Dulbecco’s Modified Eagle’s Medium (DMEM)/F12 was used with a supplement. The morphology did not show cytotoxicity, while the viability of the millimeter wave treatment group cells was similar to that of the control group. Also, the level of collagen type I, vimentin, osteoprotegerin, osteopontin, bone morphogenetic protein (BMP)-2, and osteocalcin mRNA were increased and the level of phospho extracellular signal-regulated kinase (pERK), osteonectin, and BMP-2 expression were increased in the millimeter wave treatment group. Furthermore, fluorescence activated cell sorter (FACS) analysis showed that CD 90 and CD 105 expression decreased in the millimeter wave group and immunocytochemical staining analysis showed that BMP-2 and osteopontin expression had increased in the millimeter wave group. In conclusion, our results suggest that an appropriate millimeter wave exposure can be promoted as a potent positive modulator of bone marrow stromal cells into osteoblasts-like cells.

ADAM17 is associated with EMMPRIN and predicts poor prognosis in patients with uterine cervical carcinoma.

Metalloproteinase activities of a disintegrin and metalloproteinase 17 (ADAM17), amphiregulin (AREG), extracellular matrix metalloproteinase inducer (EMMPRIN), and matrix metalloproteinases (MMPs) are involved in tumor biology. In patients with uterine cervical carcinoma, the expression and prognostic significance of ADAM17 remain to be fully elucidated. The expression of ADAM17, AREG, EMMPRIN, phospho-epidermal growth factor receptor (p-EGFR), phospho-extracellular signal-regulated kinase (p-ERK), MMP-2, and MMP-9 was assessed by immunohistochemistry and/or Western blotting from cervical carcinoma cell lines, SiHa and HeLa cells, and cervical carcinoma tissues. AREG activity was measured by ELISA assay. The correlation of ADAM17, AREG, EMMPRIN, and MMP-9 expression with patients' survival rates was assessed by Kaplan-Meier and Cox regression analyses. RNA interference (RNAi) experiment was performed using small interfering mRNA to ADAM17 and EMMPRIN. ADAM17, EMMPRIN, and MMP-9 protein content was overexpressed in cervical carcinoma tissues compared with normal cervical tissues (P < 0.05). Strong expression of ADAM17, AREG, EMMPRIN, and MMP-9 was significantly associated with stages, lymph node metastasis, differentiation, and parametrium invasion (P < 0.05). Overexpression of ADAM17, AREG, EMMPRIN, and MMP-9 was significantly correlated with short progression-free survival and overall survival (P < 0.05). Multivariate analysis suggested that lymph node metastasis, parametrium invasion, and ADAM17 expression were independent prognostic indicators for cervical cancer. ADAM17 RNAi decreased EMMPRIN, p-EGFR, p-ERK, MMP-2, and MMP-9 proteins in SiHa and HeLa cells. ELISA assay revealed that AREG activity was stimulated by ADAM17 and was reversed by ADAM17 RNAi in SiHa and HeLa cells. Our data suggest that the increased expression of ADAM17 in cervical cancer is significantly associated with aggressive progression and poor prognosis. ADAM17 may be a molecular marker for predicting the progression and prognosis in cervical cancer.

Caveolin-1 promotes an invasive phenotype and predicts poor prognosis in large cell lung carcinoma

PurposeThis study investigated the relationships of caveolin-1 expression with clinical pathologic parameters and the prognosis of patients with large cell lung carcinoma. This study also explored the roles of caveolin-1 in cell invasiveness, matrix metalloproteinase (MMP) expression, and non-small cell lung carcinoma activity in vitro. MethodsA total of 120 tissue samples were immunohistochemically analyzed for caveolin-1 expression. Cell invasion ability was measured by a Transwell invasion assay. Protein expression was assessed by Western blotting. MMP activity was detected by gelatin zymography. ResultsCaveolin-1 was expressed in 54 of 120 (45.0%) cases of large cell lung carcinoma. Caveolin-1 expression was significantly correlated with node status (N0 vs. N1, N2, and N3; P=0.005) and advanced pTNM stage (Stages I and II vs. Stage III, P<0.001). Patients with caveolin-1-positive expression had a poorer prognosis than did those with caveolin-1-negative expression (P<0.001). The knockdown of caveolin-1 in H460 and 95D cells reduced the invasive ability of the cells and the expression of phosphorylated epidermal growth factor receptor (EGFR), phospho-extracellular signal-regulated kinases 1 and 2, MMP2, and MMP9; the protein level and activity of MMP2 and MMP9 were also decreased by the inhibition of EGFR activity in H460 and 95D cells. ConclusionsThe expression of caveolin-1 was positively correlated with an advanced pathologic stage. Thus, caveolin-1 could act as a predictor of a poor prognosis in patients with large cell lung carcinoma. In addition, the downregulation of caveolin-1 reduced both the invasive ability of tumor cells and the protein and activity levels of MMP2 and MMP9 in vitro, suggesting the involvement of EGFR/MMP signaling in this process.

The water-soluble triptolide derivative PG490-88 protects against cisplatin-induced acute kidney injury.

Triptolide, a traditional Chinese medicine, has anti-inflammatory, antiproliferative, and proapoptotic properties. As interstitial inflammation and tubular apoptosis are features of cisplatin-induced acute kidney injury (AKI), we determined the effect of the water-soluble triptolide derivative 14-succinyl triptolide sodium salt (PG490-88) in a mouse model of cisplatin-induced AKI. PG490-88 resulted in a significant decrease in blood urea nitrogen (BUN), serum creatinine, and acute tubular necrosis (ATN) score, and a nonsignificant increase in tubular apoptosis score in AKI. The mitogen-activated protein kinase (MAPK) pathway is activated in AKI. On immunoblot analysis, phosphoextracellular signal-regulated kinase (p-ERK) was increased 3.6-fold in AKI and 2.0-fold inhibited by PG490-88. Phospho-c-Jun N-terminal kinase (p-JNK) was increased in AKI. PG490-88 resulted in a nonsignificant decrease in p-JNK. Phospho-p38 was not affected by cisplatin or PG490-88. MAPK phosphatase-1 (MKP-1) that negatively regulates MAPK signaling has not previously been studied in AKI. MKP-1 activity was not affected by cisplatin or PG490-88. Changes in p-ERK, p-JNK, and MKP-1 were confirmed on reverse protein phase analysis. The ERK inhibitor U0126 resulted in lower BUN and serum creatinine, suggesting a mechanistic role of ERK in AKI. The increase in interleukin-1α (IL-1α), IL-1β, IL-6, CXCL1, and IL-33 in the kidney in AKI was unaffected by PG490-88. In summary, PG490-88 protects against AKI and ATN despite no decrease in tubular apoptosis. The protection of PG490-88 against AKI was associated with a decrease in p-ERK and was independent of MKP-1 and proinflammatory cytokines. In conclusion, PG490-88 protects against cisplatin-induced AKI possibly by decreasing p-ERK.

Investigating inherent functional differences between human cardiac fibroblasts cultured from nondiabetic and Type 2 diabetic donors.

Type 2 diabetes mellitus (T2DM) promotes adverse myocardial remodeling and increased risk of heart failure; effects that can occur independently of hypertension or coronary artery disease. As cardiac fibroblasts (CFs) are key effectors of myocardial remodeling, we investigated whether inherent phenotypic differences exist in CF derived from T2DM donors compared with cells from nondiabetic (ND) donors. Cell morphology (cell area), proliferation (cell counting over 7-day period), insulin signaling [phospho-Akt and phospho-extracellular signal-regulated kinase (ERK) Western blotting], and mRNA expression of key remodeling genes [real-time reverse transcription-polymerase chain reaction (RT-PCR)] were compared in CF cultured from atrial tissue from 14 ND and 12 T2DM donors undergoing elective coronary artery bypass surgery. The major finding was that Type I collagen (COL1A1) mRNA levels were significantly elevated by twofold in cells derived from T2DM donors compared with those from ND donors; changes reflected at the protein level. T2DM cells had similar proliferation rates but a greater variation in cell size and a trend towards increased cell area compared with ND cells. Insulin-induced Akt and ERK phosphorylation were similar in the two cohorts of cells. CF from T2DM individuals possess an inherent profibrotic phenotype that may help to explain the augmented cardiac fibrosis observed in diabetic patients. We investigated whether inherent phenotypic differences exist between CF cultured from donors with or without Type 2 diabetes. Cell morphology, proliferation, insulin signaling, and gene expression were compared between multiple cell populations. The major finding was that Type I collagen levels were elevated in fibroblasts from diabetic donors, which may help explain the augmented cardiac fibrosis observed with diabetes.

Alpha-lipoic acid attenuates lipopolysaccharide-induced kidney injury

Kidney is one of the major target organs in sepsis, while effective prevention of septic acute kidney injury has not yet been established. α-Lipoic acid (LA) has been known to exert beneficial effects against lipopolysaccharide (LPS)-induced damages in various organs such as heart, lung, and liver. We investigated the protective effect of LA on LPS-induced kidney injury. Two groups of rats were treated with LPS (20 mg/kg, i.p.), one of which being co-treated with LA (50 mg/kg), while the control group was treated with vehicle alone. Human renal proximal tubular epithelial cells (HK-2 cells) were cultured with or without LPS (10 μg/ml) in the presence or absence of LA (100 μg/ml) for 3 h prior to LPS treatment. Serum creatinine level was increased in LPS-treated rats, which was attenuated by LA co-treatment. LPS treatment induced cleaved caspase-3 expression in the kidney, which was counteracted by LA. Terminal deoxynucleotidyl transferase dUTP nick-end labeling-positive cells increased in the kidneys of LPS-treated rats compared with controls, which was counteracted by LA treatment. Protein expression of inducible nitric oxide synthase and cyclooxygenase-2 detected by immunoblotting and/or immunohistochemical staining, along with mRNA levels of pro-inflammatory cytokines detected by real-time polymerase chain reaction, was increased in the kidney with LPS administration, which was ameliorated with LA treatment. LA also protected LPS-induced tubular dysfunction, preserving type 3 Na(+)/H(+) exchanger and aquaporin 2 expressions in the kidney. Suppression of LPS-induced expression of cleaved caspase-3 by LA was also observed in HK-2 cells. Increased protein expression of phospho-extracellular signal-regulated kinases 1/2 and c-Jun N-terminal kinases by LPS treatment was attenuated by LA pretreatment, while p38 was not affected by either LPS or LA treatment. MitoTracker Red demonstrated LA prevented LPS-induced increment of mitochondrial oxidative stress, where concurrent 4',6-diamidino-2-phenylindole staining also revealed marked fragmentation and condensation of nuclei in HK-2 cells treated with LPS, which was prevented by LA. LA treatment attenuates LPS-induced kidney injury, such as renal tubular dysfunction, by suppression of apoptosis, and inflammation.

Nardosinone Improves the Proliferation, Migration and Selective Differentiation of Mouse Embryonic Neural Stem Cells

In this study, we investigated the impact of Nardosinone, a bioactive component in Nardostachys root, on the proliferation and differentiation of neural stem cells. The neural stem cells were isolated from cerebrums of embryonic day 14 CD1 mice. The proliferation of cells was monitored using the cell counting kit-8 assay, bromodeoxyuridine incorporation and cell cycle analysis. Cell migration and differentiation were investigated with the neurosphere assay and cell specific markers, respectively. The results showed that Nardosinone promotes cells proliferation and increases cells migration distance in a dose-dependent manner. Nardosinone also induces the selective differentiation of neural stem cells to neurons and oligodendrocytes, as indicated by the expression of microtubule-associated protein-2 and myelin basic protein, respectively. Nardosinone also increases the expression of phospho-extracellular signal-regulated kinase and phospho-cAMP response element binding protein during proliferation and differentiation. In conclusion, this study reveals the regulatory effects of Nardosinone on neural stem cells, which may have significant implications for the treatment of brain injury and neurodegenerative diseases.