51
|
Ding J, Kuo ML, Su L, Xue L, Luh F, Zhang H, Wang J, Lin TG, Zhang K, Chu P, Zheng S, Liu X, Yen Y. Human mitochondrial pyrroline-5-carboxylate reductase 1 promotes invasiveness and impacts survival in breast cancers. Carcinogenesis 2017; 38:519-531. [PMID: 28379297 DOI: 10.1093/carcin/bgx022] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 02/21/2017] [Indexed: 12/16/2023] Open
Abstract
Human mitochondrial pyrroline-5-carboxylate reductase (PYCR) is a house-keeping enzyme that catalyzes the reduction of Δ1-pyrroline-5-carboxylate to proline. This enzymatic cycle plays pivotal roles in amino acid metabolism, intracellular redox potential and mitochondrial integrity. Here, we hypothesize that PYCR1 might be a novel prognostic biomarker and therapeutic target for breast cancer. In this study, breast cancer tissue samples were obtained from Zhejiang University (ZJU set). Immunohistochemistry analysis was performed to detect the protein level of PYCR1, and Kaplan-Meier and Cox proportional analyses were employed in this outcome study. The prognostic significance and performance of PYCR1 mRNA were validated on 13 worldwide independent microarray data sets, composed of 2500 assessable breast cancer cases. Our findings revealed that both PYCR1 mRNA and protein expression were significantly associated with tumor size, grade and invasive molecular subtypes of breast cancers. Independent and pooled analyses verified that higher PYCR1 mRNA levels were significantly associated with poor survival of breast cancer patients, regardless of estrogen receptor (ER) status. For in vitro studies, inhibition of PYCR1 by small-hairpin RNA significantly reduced the growth and invasion capabilities of the cells, while enhancing the cytotoxicity of doxorubicin in breast cancer cell lines MCF-7 (ER positive) and MDA-MB-231 (ER negative). Further population study also validated that chemotherapy significantly improved survival in early-stage breast cancer patients with low PYCR1 expression levels. Therefore, PYCR1 might serve as a prognostic biomaker for either ER-positive or ER-negative breast cancer subtypes and can also be a potential target for breast cancer therapy.
Collapse
Affiliation(s)
- Jiefeng Ding
- Shaoxing Women and Children's Hospital, Shaoxing, Zhejiang 312000, China
- City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Mei-Ling Kuo
- City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Leila Su
- Ph.D. Program of Cancer Biology and Drug Discovery, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan, ROC
| | - Lijun Xue
- Pathology Department, Loma Linda University Medical Center, Loma Linda, CA 92354, USA
| | - Frank Luh
- General Medicine Division, College of Medicine, Taipei Medical University, Taipei 110, Taiwan, ROC
- Sino-American Cancer Foundation, 4978 Santa Anita Ave, Suite #104, Temple City, CA 91780, USA
| | - Hang Zhang
- Cancer Institute, Zhejiang University, Hangzhou, Zhejiang 310009, China and
| | - Jianghai Wang
- Sino-American Cancer Foundation, 4978 Santa Anita Ave, Suite #104, Temple City, CA 91780, USA
| | - Tiffany G Lin
- Sino-American Cancer Foundation, 4978 Santa Anita Ave, Suite #104, Temple City, CA 91780, USA
| | - Keqiang Zhang
- City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Peiguo Chu
- City of Hope National Medical Center, Duarte, CA 91010, USA
| | - Shu Zheng
- Cancer Institute, Zhejiang University, Hangzhou, Zhejiang 310009, China and
| | - Xiyong Liu
- Ph.D. Program of Cancer Biology and Drug Discovery, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan, ROC
- Sino-American Cancer Foundation, 4978 Santa Anita Ave, Suite #104, Temple City, CA 91780, USA
- California Cancer Institute, Temple City, CA 91007, USA
| | - Yun Yen
- Ph.D. Program of Cancer Biology and Drug Discovery, Taipei Medical University, 250 Wu-Hsing Street, Taipei 110, Taiwan, ROC
| |
Collapse
|
52
|
Wang H, Farhan M, Xu J, Lazarovici P, Zheng W. The involvement of DARPP-32 in the pathophysiology of schizophrenia. Oncotarget 2017; 8:53791-53803. [PMID: 28881851 PMCID: PMC5581150 DOI: 10.18632/oncotarget.17339] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Accepted: 04/12/2017] [Indexed: 02/07/2023] Open
Abstract
Schizophrenia is one of the most devastating heterogeneous psychiatric disorders. The dopamine hypothesis is the longest standing pathoetiologic theory of schizophrenia based on neurochemical evidences of elevated brain striatal dopamine synthesis capacity and increased dopamine release in response to stress. Dopamine and cyclic AMP-regulated phosphoprotein of relative molecular mass 32,000 (DARPP-32) is a cytosolic protein highly enriched in the medium spiny neurons of the neostriatum, considered as the most important integrator between the cortical input and the basal ganglia, and associated with motor control. Accumulating evidences has indicated the involvement of DARPP-32 in the development of schizophrenia; i. DARPP-32 phosphorylation is regulated by several neurotransmitters, including dopamine and glutamate, neurotransmitters implicated in schizophrenia pathogenesis; ii. decrease of both total and phosphorylated DARPP-32 in the prefrontal cortex are observed in schizophrenic animal models; iii. postmortem brain studies indicated decreased expression of DARPP-32 protein in the superior temporal gyrus and dorsolateral prefrontal cortex in patients with schizophrenia; iv. DARPP-32 phosphorylation is increased upon therapy with antipsychotic drugs, such as haloperidol and risperidone which improve behavioral performance in experimental animal models and patients; v. Genetic analysis of the gene coding for DARPP-32 propose an association with schizophrenia. Cumulatively, these findings implicate DARPP-32 protein in schizophrenia and propose it as a potential therapeutic target. Here, we summarize the possible roles of DARPP-32 during the development of schizophrenia and make some recommendations for future research. We propose that DARPP-32 and its interacting proteins may serve as potential therapeutic targets in the treatment of schizophrenia.
Collapse
Affiliation(s)
- Haitao Wang
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China.,School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Mohd Farhan
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| | - Jiangping Xu
- School of Pharmaceutical Sciences, Southern Medical University, Guangzhou, China
| | - Philip Lazarovici
- School of Pharmacy Institute for Drug Research, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Wenhua Zheng
- Faculty of Health Sciences, University of Macau, Taipa, Macau, China
| |
Collapse
|
53
|
Rao Z, Wang S, Wang J. Peroxiredoxin 4 inhibits IL-1β-induced chondrocyte apoptosis via PI3K/AKT signaling. Biomed Pharmacother 2017; 90:414-420. [PMID: 28391163 DOI: 10.1016/j.biopha.2017.03.075] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 03/14/2017] [Accepted: 03/25/2017] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Chondrocytes apoptosis induced by reactive oxygen species (ROS) plays a critical role in the pathogenesis of osteoarthritis (OA). Peroxiredoxin 4 (PRDX4), a member of the PRDX family, is essential for removing metabolic free radicals and reducing intracellular ROS. In this study, we sought to investigate the roles of PRDX4 on interleukin 1β (IL-1β)-induced chondrocyte apoptosis. METHODS Primary chondrocytes were isolated from the articular cartilage of Sprague-Dawley rats, infected with PRDX4 overexpressing lentivirus and treated with IL-1β (10ng/mL). Cell apoptosis and ROS production identified by flow cytometry. Protein expression levels was evaluated by Western blotting analysis. Nitric oxide (NO) production and Caspase-3/9 activation were assessed by the Griess reaction method and colorimetric assay kit, respectively. RESULTS PRDX4 overexpression in chondrocytes significantly decreased IL-1β-induced apoptosis. It also reversed the activity of IL-1β that increased ROS and NO production. PRDX4 overexpression reversed the activity of IL-1β that reduced the levels of Bcl-2, p-AKT and p-PRAS40, as well as increased Bax levels and Caspase-3/9 activation. More importantly, pre-treated with AKT inhibitor (AZD5363) significantly reduced the protective effects of PRDX4. CONCLUSIONS Our data demonstrated that the regulatory effects of PRDX4 on IL-1β-induced chondrocyte apoptosis can be partially attributed to phosphatidylinositol 3-kinase/AKT signaling. These results indicate that PRDX4 might play a protective role in OA cartilage degeneration.
Collapse
Affiliation(s)
- Zhitao Rao
- Department of Orthopaedics, Tongji Hospital, Tongji University School of Medicine, Shanghai, 20065, China
| | - Shuqing Wang
- Department of Orthopaedics, Tongji Hospital, Tongji University School of Medicine, Shanghai, 20065, China.
| | - Jiaqi Wang
- Department of Orthopaedics, Tongji Hospital, Tongji University School of Medicine, Shanghai, 20065, China
| |
Collapse
|
54
|
Wang C, Liang C, Feng W, Xia X, Chen F, Qiao E, Zhang X, Chen D, Ling Z, Yang H. ICT1 knockdown inhibits breast cancer cell growth via induction of cell cycle arrest and apoptosis. Int J Mol Med 2017; 39:1037-1045. [PMID: 28290601 DOI: 10.3892/ijmm.2017.2913] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Accepted: 01/23/2017] [Indexed: 11/05/2022] Open
Abstract
The protein encoded by immature colon carcinoma transcript 1 (ICT1) is a component of the human mitochondrial ribosome, and is reported to be implicated in cell proliferation, viability and apoptosis of HeLa cells. This study was conducted to investigate the role of ICT1 in human breast cancer. Oncomine database was used to investigate ICT1 expression in human breast cancer tissues compared to normal tissues. The results showed that ICT1 was highly overexpressed in various human breast cancer subtypes. Then short hairpin RNA (shRNA)-mediated knockdown of ICT1 was performed in human breast cancer ZR-75-30 and T-47D cells. A series of functional analysis, including MTT, colony formation and flow cytometry assays were conducted after ICT1 knockdown. Our results demonstrated that knockdown of ICT1 significantly suppressed cell viability and proliferation through cell cycle arrest at the G2/M phase and induced apoptosis in breast cancer cells. Furthermore, knockdown of ICT1 altered signaling pathways associated with cell growth and apoptosis, including phospho‑BAD (Ser112), phospho-PRAS40 (Thr246) and induction of phospho‑AMPKα (Thr172). Additionally, it was further confirmed by western blot analysis that ICT1 knockdown altered the expression of apoptosis- or cell cycle‑related proteins such as Bcl-2, caspase-3, CDK1, CDK2 and cyclin B. In conclusion, targeting ICT1 in breast cancer cells may provide a new strategy for breast cancer gene therapy.
Collapse
Affiliation(s)
- Chen Wang
- Department of Oncology, First Clinical Medical College, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| | - Chenlu Liang
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Weiliang Feng
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Xianghou Xia
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Feng Chen
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Enqi Qiao
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Xiping Zhang
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Daobao Chen
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Zhiqiang Ling
- Department of Breast Surgery, Zhejiang Cancer Hospital, Hangzhou, Zhejiang 310022, P.R. China
| | - Hongjian Yang
- Department of Oncology, First Clinical Medical College, Wenzhou Medical University, Wenzhou, Zhejiang 325000, P.R. China
| |
Collapse
|
55
|
Ma Y, Feng J, Xing X, Zhou B, Li S, Zhang W, Jiang J, Zhang J, Qiao Z, Sun L, Ma Z, Kong R. miR-1908 Overexpression Inhibits Proliferation, Changing Akt Activity and p53 Expression in Hypoxic NSCLC Cells. Oncol Res 2017; 24:9-15. [PMID: 27178817 PMCID: PMC7838668 DOI: 10.3727/096504016x14570992647168] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The ribosomal protein (RP)-p53 pathway has been shown to play a key role in apoptosis and senescence of cancer cells. miR-1908 is a newly found miRNA that was reported to have prognostic potential in melanoma. However, its role and mechanism in the progression of non-small cell lung cancer (NSCLC) are largely unknown. In this study, we found that expression of miR-1908 was significantly downregulated in human NSCLC cell lines, including SK-MES-1, A549, and NCI-H460. Then the role of miR-1908 in NSCLC cell proliferation was explored. The miR-1908 mimic was transfected into NSCLC cell lines, and their proliferation was detected. MTT and Cell Titer-Blue H analyses showed that the cell proliferation was notably reduced by the miR-1908 mimic transfection. Moreover, we found the RP-p53 pathway was activated by miR-1908 mimic. Moreover, the miR-1908 inhibitor transfection had a completely opposite effect on the NSCLC cell proliferation than that of miR-1908 mimic. To explore the underlying mechanism of that, TargetScan bioinformatics server and 3'-UTR luciferase reporter assay were applied to identify the targets of miR-1908. Our results showed that AKT1 substrate 1 (AKT1S1), a newly proven suppressor of the RP-p53 pathway, was a target of miR-1908, suggesting a probable mechanism for miR-191 suppressing NSCLC cell proliferation. Our findings provide a novel molecular target for the regulation of NSCLC cell proliferation.
Collapse
Affiliation(s)
- Yuefeng Ma
- Department of Thoracic Surgery, the Second Affiliated Hospital of Medical School, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
56
|
Rosa MD, Distefano G, Gagliano C, Rusciano D, Malaguarnera L. Autophagy in Diabetic Retinopathy. Curr Neuropharmacol 2017; 14:810-825. [PMID: 26997506 PMCID: PMC5333581 DOI: 10.2174/1570159x14666160321122900] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2015] [Revised: 11/08/2015] [Accepted: 11/10/2015] [Indexed: 12/19/2022] Open
Abstract
Autophagy is an important homeostatic cellular process encompassing a number of consecutive steps indispensable for degrading and recycling cytoplasmic materials. Basically autophagy is an adaptive response that under stressful conditions guarantees the physiological turnover of senescent and impaired organelles and, thus, controls cell fate by various cross-talk signals. Diabetic retinopathy (DR) is a serious microvascular complication of diabetes and accounts for 5% of all blindness. Although, various metabolic disorders have been linked with the onset of DR, due to the complex character of this multi-factorial disease, a connection between any particular defect and DR becomes speculative. Diabetes increases inflammation, advanced glycation end products (AGEs) and oxidative stress in the retina and its capillary cells. Particularly, a great number of evidences suggest a mutual connection between oxidative stress and other major metabolic abnormalities implicated in the development of DR. In addition, the intricate networks between autophagy and apoptosis establish the degree of cellular apoptosis and the progression of DR. Growing data underline the crucial role of reactive oxygen species (ROS) in the activation of autophagy. Depending on their delicate balance both redox signaling and autophagy, being detrimental or beneficial, retain opposing effects. The molecular mechanisms of autophagy are very complex and involve many signaling pathways cooperating at various steps. This review summarizes recent advances of the possible molecular mechanisms in autophagic process that are involved in pathophysiology of DR. In-depth analysis on the molecular mechanisms leading to autophagy in the retinal pigment epithelial (RPE) will be helpful to plan new therapies aimed at preventing or improving the progression of DR.
Collapse
Affiliation(s)
| | | | | | | | - Lucia Malaguarnera
- Department of Biomedical and Biotechnological Sciences, Faculty of Medicine, University of Catania, 95124 Catania, Italy
| |
Collapse
|
57
|
Tsolou A, Liousia M, Kalamida D, Pouliliou S, Giatromanolaki A, Koukourakis M. Inhibition of IKK-NFκB pathway sensitizes lung cancer cell lines to radiation. Cancer Biol Med 2017; 14:293-301. [PMID: 28884046 PMCID: PMC5570606 DOI: 10.20892/j.issn.2095-3941.2017.0049] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Objective : Cancer cell radioresistance is a stumbling block in radiation therapy. The activity in the nuclear factor kappa B (NFκB) pathway correlates with anti-apoptotic mechanisms and increased radioresistance. The IKK complex plays a major role in NFκB activation upon numerous signals. In this study, we examined the interaction between ionizing radiation (IR) and different members of the IKK-NFκB pathway, as well as upstream activators, RAF1, ERK, and AKT1. Methods : The effect of 4 Gy of IR on the expression of the RAF1-ERK-IKK-NFκB pathway was examined in A549 and H1299 lung cancer cell lines using Western blot analysis and confocal microscopy. We examined changes in radiation sensitivity using gene silencing or pharmacological inhibitors of ERK and IKKβ. Results : IKKα, IKKγ, and IκBα increased upon exposure to IR, thereby affecting nuclear levels of NFκB (phospho-p65). ERK inhibition or siRNA-mediated down-regulation of RAF1 suppressed the post-irradiation survival of the examined lung cancer cell lines. A similar effect was detected on survival upon silencing IKKα/IKKγ or inhibiting IKKβ. Conclusions : Exposure of lung cancer cells to IR results in NFκB activation via IKK. The genetic or pharmacological blockage of the RAF1-ERK-IKK-NFκB pathway sensitizes cells to therapeutic doses of radiation. Therefore, the IKK pathway is a promising target for therapeutic intervention in combination with radiotherapy.
Collapse
|
58
|
Zeng S, Song H, Chen Y, Xie W, Zhang L. B7-H4-mediated immunoresistance is supressed by PI3K/Akt/mTOR pathway inhibitors. Mol Biol 2016. [DOI: 10.1134/s0026893316060248] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
|
59
|
Dai B, Wu Q, Zeng C, Zhang J, Cao L, Xiao Z, Yang M. The effect of Liuwei Dihuang decoction on PI3K/Akt signaling pathway in liver of type 2 diabetes mellitus (T2DM) rats with insulin resistance. JOURNAL OF ETHNOPHARMACOLOGY 2016; 192:382-389. [PMID: 27401286 DOI: 10.1016/j.jep.2016.07.024] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 05/17/2016] [Accepted: 07/07/2016] [Indexed: 05/22/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Liuwei Dihaung decoction (LWDHT) is a well-known classic traditional Chinese medicine formula, consists of six herbs including Rehmannia glutinosa Libosch.(family: Scrophulariaceae), Cornus officinalis Sieb.(family: Cornaceae), Dioscorea opposite Thunb.(family: Dioscoreaceae), Alisma orientale(G. Samuelsson) Juz (family: Alismataceae), Poria cocos (Schw.) Wolf (family: Polyporaceae) and Paeonia suffruticosa Andrews (family: Paeoniaceae). It has been used in the treatment of many types of diseases with signs of deficiency of Yin in the kidneys in China clinically. This study is aimed at investigating the effect of Liuwei dihuang decoction on PI3K/Akt signaling pathway in liver of T2DM rats with insulin resistance. MATERIALS AND METHODS T2DM model was induced in male Sprague-Dawley (SD) rats by high sugar and high fat diets combined with small dose of streptozocin (STZ) injection. The successful T2DM rats were randomly allocated three group--vehicle group, positive control group and Liuwei Dihuang decoction group. After 12-weeks treatment with distilled water, rosiglitazone and LWDHT by intragastric administration respectively, the rats were put to death in batches. The variance of fasting blood glucose (FBG) and fasting insulin (FINS) in serum were determined, the pathological changes of each rats' liver were observed by hematoxylin-eosin (HE) staining, the expression of insulin receptor substrate 2(IRS2), phosphatidylinositol 3-kinase (PI3K) and protein kinas B (Akt) involving the canonical PI3K/Akt signaling pathway were detected by Real-time fluorescent quantitative PCR (RT-PCR), and the expression level of IRS2, PI3K, Akt protein and phosphorylated IRS2, PI3K, Akt protein were evaluated by Western Blot. All the data were analyzed by SPSS 17.0. RESULTS Four weeks of treatment with LWDHT could significantly decrease the level of FBG and FINS in serum, improve the cellular morphology of liver, kidney, pancreas tissue, and the expression of IRS2, PI3K, Akt mRNA and phosphorylated IRS2, PI3K, Akt protein involved in the canonical PI3K/Akt signaling pathway of T2DM rats in liver were significantly up-regulated, while the total IRS2, PI3K, and Akt protein had no obvious changes. CONCLUSIONS The results suggest that Liuwei Dihuang decoction could intervene insulin resistance of T2DM, in part, through regulation of canonical PI3K/Akt signaling pathway of T2DM rats in liver.
Collapse
MESH Headings
- Animals
- Biomarkers/blood
- Blood Glucose/drug effects
- Blood Glucose/metabolism
- Diabetes Mellitus, Experimental/blood
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/enzymology
- Diabetes Mellitus, Type 2/blood
- Diabetes Mellitus, Type 2/chemically induced
- Diabetes Mellitus, Type 2/drug therapy
- Diabetes Mellitus, Type 2/enzymology
- Drugs, Chinese Herbal/pharmacology
- Gene Expression Regulation, Enzymologic
- Hypoglycemic Agents/pharmacology
- Insulin/blood
- Insulin Receptor Substrate Proteins/genetics
- Insulin Receptor Substrate Proteins/metabolism
- Insulin Resistance
- Liver/drug effects
- Liver/enzymology
- Liver/pathology
- Male
- Pancreas/drug effects
- Pancreas/enzymology
- Pancreas/pathology
- Phosphatidylinositol 3-Kinase/genetics
- Phosphatidylinositol 3-Kinase/metabolism
- Phosphorylation
- Proto-Oncogene Proteins c-akt/genetics
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats, Sprague-Dawley
- Signal Transduction/drug effects
- Streptozocin
- Time Factors
Collapse
Affiliation(s)
- Bing Dai
- The First Affiliated Hospital of Hunan University of Traditional Chinese Medicine, Shaoshan Road, Changsha, Hunan 410007, China.
| | - Qinxuan Wu
- Changsha Medical University, Changsha, Hunan 410219, China
| | - Chengxi Zeng
- Changsha Social Work College, Changsha, Hunan 410000, China
| | - Jiani Zhang
- Changsha Medical University, Changsha, Hunan 410219, China
| | - Luting Cao
- Changsha Medical University, Changsha, Hunan 410219, China
| | - Zizeng Xiao
- Changsha Social Work College, Changsha, Hunan 410000, China.
| | - Menglin Yang
- Hunan University of Traditional Chinese Medicine, Changsha, Hunan 410208
| |
Collapse
|
60
|
Maiese K. Targeting molecules to medicine with mTOR, autophagy and neurodegenerative disorders. Br J Clin Pharmacol 2016; 82:1245-1266. [PMID: 26469771 PMCID: PMC5061806 DOI: 10.1111/bcp.12804] [Citation(s) in RCA: 143] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2015] [Revised: 10/11/2015] [Accepted: 10/13/2015] [Indexed: 12/14/2022] Open
Abstract
Neurodegenerative disorders are significantly increasing in incidence as the age of the global population continues to climb with improved life expectancy. At present, more than 30 million individuals throughout the world are impacted by acute and chronic neurodegenerative disorders with limited treatment strategies. The mechanistic target of rapamycin (mTOR), also known as the mammalian target of rapamycin, is a 289 kDa serine/threonine protein kinase that offers exciting possibilities for novel treatment strategies for a host of neurodegenerative diseases that include Alzheimer's disease, Parkinson's disease, Huntington's disease, epilepsy, stroke and trauma. mTOR governs the programmed cell death pathways of apoptosis and autophagy that can determine neuronal stem cell development, precursor cell differentiation, cell senescence, cell survival and ultimate cell fate. Coupled to the cellular biology of mTOR are a number of considerations for the development of novel treatments involving the fine control of mTOR signalling, tumourigenesis, complexity of the apoptosis and autophagy relationship, functional outcome in the nervous system, and the intimately linked pathways of growth factors, phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), AMP activated protein kinase (AMPK), silent mating type information regulation two homologue one (Saccharomyces cerevisiae) (SIRT1) and others. Effective clinical translation of the cellular signalling mechanisms of mTOR offers provocative avenues for new drug development in the nervous system tempered only by the need to elucidate further the intricacies of the mTOR pathway.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey, 07101, USA.
| |
Collapse
|
61
|
Chu P, Han G, Ahsan A, Sun Z, Liu S, Zhang Z, Sun B, Song Y, Lin Y, Peng J, Tang Z. Phosphocreatine protects endothelial cells from Methylglyoxal induced oxidative stress and apoptosis via the regulation of PI3K/Akt/eNOS and NF-κB pathway. Vascul Pharmacol 2016; 91:26-35. [PMID: 27590258 DOI: 10.1016/j.vph.2016.08.012] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Revised: 08/03/2016] [Accepted: 08/27/2016] [Indexed: 01/01/2023]
Abstract
Methylglyoxal (MGO), an active metabolite of glucose, can cause cellular injury which has an affinity for the progression of diabetes-associated atherosclerosis. Phosphocreatine (PCr) is a well-known high-energy phosphate compound. However, its protective effects and mechanism in the formation of a diabetes-associated atherosclerosis have not been clarified. In the present study, we investigated whether PCr could prevent MGO-induced apoptosis in human umbilical vascular endothelial cells (HUVECs) and explored the possible mechanisms. Cells were pre-treated with PCr and then stimulated with MGO. Cell morphology, cytotoxicity and apoptosis were assessed by light microscopy, MTT assay, and Annexin V-FITC respectively. Apoptotic-related proteins were evaluated by Western blotting. Reactive oxygen species (ROS) generation, intracellular calcium and mitochondrial membrane potential (MMP) were measured with fluorescent probes. Our results showed that PCr dose-dependently prevented MGO associated HUVEC cytotoxicity and suppressed MGO activated ROS generation as well as apoptotic biochemical changes such as lactate dehydrogenase, malondialdehyde leakage, loss of MMP, decreased Bcl-2/Bax protein ratio, levels of caspase-3 and 9. In addition, the antiapoptotic effect of PCr enhanced p-Akt/Akt protein ratio, NO synthase (eNOS) activation, NO production and cGMP levels and also was partially suppressed by a PI3K inhibitor (LY294002). Furthermore, PCr also inhibited MGO-induced transcriptional activity of Nuclear factor kappa B (NFκB). In conclusion, our data described that PCr exerts an antiapoptotic effect in HUVECs exposed to oxidative stress by MGO through the mitochondrial pathway and the modulation of PI3K/Akt/eNOS and NF-κB signaling pathway. Thus, it might be a candidate therapeutic agent for diabetic-associated cardiovascular diseases.
Collapse
Affiliation(s)
- Peng Chu
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Guozhu Han
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Anil Ahsan
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Zhengwu Sun
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Shumin Liu
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Zonghui Zhang
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Bin Sun
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Yanlin Song
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Yuan Lin
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Jinyong Peng
- Pharmacology Department, Dalian Medical University, Dalian, China
| | - Zeyao Tang
- Pharmacology Department, Dalian Medical University, Dalian, China.
| |
Collapse
|
62
|
Shin MJ, Kim DW, Jo HS, Cho SB, Park JH, Lee CH, Yeo EJ, Choi YJ, Kim JA, Hwang JS, Sohn EJ, Jeong JH, Kim DS, Kwon HY, Cho YJ, Lee K, Han KH, Park J, Eum WS, Choi SY. Tat-PRAS40 prevent hippocampal HT-22 cell death and oxidative stress induced animal brain ischemic insults. Free Radic Biol Med 2016; 97:250-262. [PMID: 27317854 DOI: 10.1016/j.freeradbiomed.2016.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/27/2016] [Accepted: 06/14/2016] [Indexed: 12/13/2022]
Abstract
Proline rich Akt substrate (PRAS40) is a component of mammalian target of rapamycin complex 1 (mTORC1) and is known to play an important role against reactive oxygen species-induced cell death. However, the precise function of PRAS40 in ischemia remains unclear. Thus, we investigated whether Tat-PRAS40, a cell-permeable fusion protein, has a protective function against oxidative stress-induced hippocampal neuronal (HT-22) cell death in an animal model of ischemia. We showed that Tat-PRAS40 transduced into HT-22 cells, and significantly protected against cell death by reducing the levels of H2O2 and derived reactive species, and DNA fragmentation as well as via the regulation of Bcl-2, Bax, and caspase 3 expression levels in H2O2 treated cells. Also, we showed that transduced Tat-PARS40 protein markedly increased phosphorylated RRAS40 expression levels and 14-3-3σ complex via the Akt signaling pathway. In an animal ischemia model, Tat-PRAS40 effectively transduced into the hippocampus in animal brain and significantly protected against neuronal cell death in the CA1 region. We showed that Tat-PRAS40 protein effectively transduced into hippocampal neuronal cells and markedly protected against neuronal cell damage. Therefore, we suggest that Tat-PRAS40 protein may be used as a therapeutic protein for ischemia and oxidative stress-induced brain disorders.
Collapse
Affiliation(s)
- Min Jea Shin
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea
| | - Hyo Sang Jo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Su Bin Cho
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Jung Hwan Park
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Chi Hern Lee
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Eun Ji Yeo
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Yeon Joo Choi
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Ji An Kim
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea; Bioceltran Co., Ltd., Chuncheon 24234, Republic of Korea
| | - Jung Soon Hwang
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea; Bioceltran Co., Ltd., Chuncheon 24234, Republic of Korea
| | - Eun Jeong Sohn
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Ji-Heon Jeong
- Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 31538, Republic of Korea
| | - Duk-Soo Kim
- Department of Anatomy, College of Medicine, Soonchunhyang University, Cheonan-Si 31538, Republic of Korea
| | - Hyeok Yil Kwon
- Department of Physiology, College of Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Yong-Jun Cho
- Department of Neurosurgery, Hallym University Medical Center, Chuncheon 24253, Republic of Korea
| | - Keunwook Lee
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Kyu Hyung Han
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Jinseu Park
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea
| | - Won Sik Eum
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea.
| | - Soo Young Choi
- Department of Biomedical Science and Research Institute of Bioscience and Biotechnology, Hallym University, Chuncheon 24252, Republic of Korea.
| |
Collapse
|
63
|
Velazquez R, Shaw DM, Caccamo A, Oddo S. Pim1 inhibition as a novel therapeutic strategy for Alzheimer's disease. Mol Neurodegener 2016; 11:52. [PMID: 27412291 PMCID: PMC4944476 DOI: 10.1186/s13024-016-0118-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2016] [Accepted: 07/02/2016] [Indexed: 01/07/2023] Open
Abstract
Background Alzheimer’s disease (AD) is the most prevalent neurodegenerative disorder worldwide. Clinically, AD is characterized by impairments of memory and cognitive functions. Accumulation of amyloid-β (Aβ) and neurofibrillary tangles are the prominent neuropathologies in patients with AD. Strong evidence indicates that an imbalance between production and degradation of key proteins contributes to the pathogenesis of AD. The mammalian target of rapamycin (mTOR) plays a key role in maintaining protein homeostasis as it regulates both protein synthesis and degradation. A key regulator of mTOR activity is the proline-rich AKT substrate 40 kDa (PRAS40), which directly binds to mTOR and reduces its activity. Notably, AD patients have elevated levels of phosphorylated PRAS40, which correlate with Aβ and tau pathologies as well as cognitive deficits. Physiologically, PRAS40 phosphorylation is regulated by Pim1, a protein kinase of the protoconcogene family. Here, we tested the effects of a selective Pim1 inhibitor (Pim1i), on spatial reference and working memory and AD-like pathology in 3xTg-AD mice. Results We have identified a Pim1i that crosses the blood brain barrier and reduces PRAS40 phosphorylation. Pim1i-treated 3xTg-AD mice performed significantly better than their vehicle treated counterparts as well as non-transgenic mice. Additionally, 3xTg-AD Pim1i-treated mice showed a reduction in soluble and insoluble Aβ40 and Aβ42 levels, as well as a 45.2 % reduction in Aβ42 plaques within the hippocampus. Furthermore, phosphorylated tau immunoreactivity was reduced in the hippocampus of Pim1i–treated 3xTg-AD mice by 38 %. Mechanistically, these changes were linked to a significant increase in proteasome activity. Conclusion These results suggest that reductions in phosphorylated PRAS40 levels via Pim1 inhibition reduce Aβ and Tau pathology and rescue cognitive deficits by increasing proteasome function. Given that Pim1 inhibitors are already being tested in ongoing human clinical trials for cancer, the results presented here may open a new venue of drug discovery for AD by developing more Pim1 inhibitors.
Collapse
Affiliation(s)
- Ramon Velazquez
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA
| | - Darren M Shaw
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA.,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA
| | - Antonella Caccamo
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA
| | - Salvatore Oddo
- Neurodegenerative Disease Research Center, Biodesign Institute, School of Life Sciences, Arizona State University, 727 E. Tyler Street, Tempe, AZ, 85287-5001, USA. .,School of Life Sciences, Arizona State University, Tempe, AZ, 85287, USA.
| |
Collapse
|
64
|
Abstract
As a key regulator of cell metabolism and survival, mechanistic target of rapamycin (mTOR) emerges as a novel therapeutic target for Parkinson's disease (PD). A growing body of research indicates that restoring perturbed mTOR signaling in PD models can prevent neuronal cell death. Nevertheless, molecular mechanisms underlying mTOR-mediated effects in PD have not been fully understood yet. Here, we review recent progress in characterizing the association of mTOR signaling with PD risk factors and further discuss the potential roles of mTOR in PD.
Collapse
|
65
|
Yi GZ, Liu YW, Xiang W, Wang H, Chen ZY, Xie SD, Qi ST. Akt and β-catenin contribute to TMZ resistance and EMT of MGMT negative malignant glioma cell line. J Neurol Sci 2016; 367:101-6. [PMID: 27423571 DOI: 10.1016/j.jns.2016.05.054] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 05/05/2016] [Accepted: 05/30/2016] [Indexed: 10/21/2022]
Abstract
Glioblastoma is one of the most lethal cancers in central nervous system, and some individual cells that cannot be isolated for surgical resection and also show treatment-resistance induce poor prognosis. Hence, in order to research these cells, we treated temozolomide (TMZ)-sensitive U87MG cells with 400μM TMZ in culture media for over 6months and established TMZ-resistant cell line designated as U87/TR. We detected the MGMT status through pyrosequencing and western blotting, and we also assessed the proliferation, migration, EMT-like changes and possible activated signaling pathways in U87/TR cells. Our results demonstrated that U87/TR was MGMT negative, which indicated that MGMT made no contribution for TMZ-resistance of U87/TR. And U87/TR cells displayed cell cycle arrest, higher capacity for migration and EMT-like changes including both phenotype and characteristic proteins. We also revealed that both β-catenin and the phosphorylation level of Akt and PRAS40 were increased in U87/TR, while we did not observe the phosphorylation of mTOR in U87/TR. It indicated that activation of Akt and Wnt/β-catenin pathways may be response for the chemo-resistance and increased invasion of U87/TR cells, and the phosphorylation of PRAS40 and inactivated mTOR may be related to cell cycle arrest in U87/TR cells.
Collapse
Affiliation(s)
- Guo-Zhong Yi
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Ya-Wei Liu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; The Laboratory of Precision Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Wei Xiang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Hai Wang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Zi-Yang Chen
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Si-di Xie
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China
| | - Song-Tao Qi
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; The Laboratory of Precision Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China; Nanfang Glioma Center, Guangzhou 510515, China.
| |
Collapse
|
66
|
Maiese K. Novel nervous and multi-system regenerative therapeutic strategies for diabetes mellitus with mTOR. Neural Regen Res 2016; 11:372-85. [PMID: 27127460 PMCID: PMC4828986 DOI: 10.4103/1673-5374.179032] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Throughout the globe, diabetes mellitus (DM) is increasing in incidence with limited therapies presently available to prevent or resolve the significant complications of this disorder. DM impacts multiple organs and affects all components of the central and peripheral nervous systems that can range from dementia to diabetic neuropathy. The mechanistic target of rapamycin (mTOR) is a promising agent for the development of novel regenerative strategies for the treatment of DM. mTOR and its related signaling pathways impact multiple metabolic parameters that include cellular metabolic homeostasis, insulin resistance, insulin secretion, stem cell proliferation and differentiation, pancreatic β-cell function, and programmed cell death with apoptosis and autophagy. mTOR is central element for the protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) and is a critical component for a number of signaling pathways that involve phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), AMP activated protein kinase (AMPK), silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), Wnt1 inducible signaling pathway protein 1 (WISP1), and growth factors. As a result, mTOR represents an exciting target to offer new clinical avenues for the treatment of DM and the complications of this disease. Future studies directed to elucidate the delicate balance mTOR holds over cellular metabolism and the impact of its broad signaling pathways should foster the translation of these targets into effective clinical regimens for DM.
Collapse
|
67
|
Chong ZZ. Targeting PRAS40 for multiple diseases. Drug Discov Today 2016; 21:1222-31. [PMID: 27086010 DOI: 10.1016/j.drudis.2016.04.005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/18/2016] [Accepted: 04/07/2016] [Indexed: 12/19/2022]
Abstract
Proline-rich Akt substrate 40kDa (PRAS40) bridges cell signaling between protein kinase B (Akt) and the mammalian target of rapamycin complex 1 (mTORC1). Both Akt and mTORC1 can phosphorylate PRAS40. As a negative regulator of mTORC1, PRAS40 prevents the binding of mTOR to its substrates. The phosphorylation of PRAS40 results in its dissociation from mTORC1 and enhanced mTOR activation. PRAS40 in conjunction with mTORC1 has been closely associated with programmed cell death and is implicated in diabetes mellitus (DM), cardiovascular diseases, cancer, and neurological diseases. Thus, targeting PRAS40 might hold great promise for innovative therapeutic strategies for these diseases.
Collapse
Affiliation(s)
- Zhao Zhong Chong
- Department of Anesthesiology, University of Illinois at Chicago, Chicago, IL, USA; Institute of Materia Medica, Shandong Academy of Medical Sciences, Jinan, China.
| |
Collapse
|
68
|
Wang H, Arias EB, Cartee GD. Calorie restriction leads to greater Akt2 activity and glucose uptake by insulin-stimulated skeletal muscle from old rats. Am J Physiol Regul Integr Comp Physiol 2016; 310:R449-58. [PMID: 26739650 DOI: 10.1152/ajpregu.00449.2015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 12/30/2015] [Indexed: 11/22/2022]
Abstract
Skeletal muscle insulin resistance is associated with many common age-related diseases, but moderate calorie restriction (CR) can substantially elevate glucose uptake by insulin-stimulated skeletal muscle from both young and old rats. The current study evaluated the isolated epitrochlearis muscle from ∼24.5-mo-old rats that were either fed ad libitum (AL) or subjected to CR (consuming ∼65% of ad libitum, AL, intake beginning at ∼22.5 mo old). Some muscles were also incubated with MK-2206, a potent and selective Akt inhibitor. The most important results were that in isolated muscles, CR vs. AL resulted in 1) greater insulin-stimulated glucose uptake 2) that was accompanied by significantly increased insulin-mediated activation of Akt2, as indicated by greater phosphorylation on both Thr(309) and Ser(474) along with greater Akt2 activity, 3) concomitant with enhanced phosphorylation of several Akt substrates, including an Akt substrate of 160 kDa on Thr(642) and Ser(588), filamin C on Ser(2213) and proline-rich Akt substrate of 40 kDa on Thr(246), but not TBC1D1 on Thr(596); and 4) each of the CR effects was eliminated by MK-2206. These data provide compelling new evidence linking greater Akt2 activation to the CR-induced elevation of insulin-stimulated glucose uptake by muscle from old animals.
Collapse
Affiliation(s)
- Haiyan Wang
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan; College of Physical Education and Health, East China Normal University, Shanghai, China
| | - Edward B Arias
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan
| | - Gregory D Cartee
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, Michigan; Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, Michigan; and Institute of Gerontology, University of Michigan, Ann Arbor, Michigan
| |
Collapse
|
69
|
Maiese K. Erythropoietin and mTOR: A "One-Two Punch" for Aging-Related Disorders Accompanied by Enhanced Life Expectancy. Curr Neurovasc Res 2016; 13:329-340. [PMID: 27488211 PMCID: PMC5079807 DOI: 10.2174/1567202613666160729164900] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Revised: 07/12/2016] [Accepted: 07/14/2016] [Indexed: 12/16/2022]
Abstract
Life expectancy continues to increase throughout the world, but is accompanied by a rise in the incidence of non-communicable diseases. As a result, the benefits of an increased lifespan can be limited by aging-related disorders that necessitate new directives for the development of effective and safe treatment modalities. With this objective, the mechanistic target of rapamycin (mTOR), a 289-kDa serine/threonine protein, and its related pathways of mTOR Complex 1 (mTORC1), mTOR Complex 2 (mTORC2), proline rich Akt substrate 40 kDa (PRAS40), AMP activated protein kinase (AMPK), Wnt signaling, and silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), have generated significant excitement for furthering novel therapies applicable to multiple systems of the body. Yet, the biological and clinical outcome of these pathways can be complex especially with oversight of cell death mechanisms that involve apoptosis and autophagy. Growth factors, and in particular erythropoietin (EPO), are one avenue under consideration to implement control over cell death pathways since EPO can offer potential treatment for multiple disease entities and is intimately dependent upon mTOR signaling. In experimental and clinical studies, EPO appears to have significant efficacy in treating several disorders including those involving the developing brain. However, in mature populations that are affected by aging-related disorders, the direction for the use of EPO to treat clinical disease is less clear that may be dependent upon a number of factors including the understanding of mTOR signaling. Continued focus upon the regulatory elements that control EPO and mTOR signaling could generate critical insights for targeting a broad range of clinical maladies.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
| |
Collapse
|
70
|
Abeyrathna P, Su Y. The critical role of Akt in cardiovascular function. Vascul Pharmacol 2015; 74:38-48. [PMID: 26025205 PMCID: PMC4659756 DOI: 10.1016/j.vph.2015.05.008] [Citation(s) in RCA: 303] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/07/2015] [Accepted: 05/16/2015] [Indexed: 12/30/2022]
Abstract
Akt kinase, a member of AGC kinases, is important in many cellular functions including proliferation, migration, cell growth and metabolism. There are three known Akt isoforms which play critical and diverse roles in the cardiovascular system. Akt activity is regulated by its upstream regulatory pathways at transcriptional and post-translational levels. Beta-catenin/Tcf-4, GLI1 and Stat-3 are some of few known transcriptional regulators of AKT gene. Threonine 308 and serine 473 are the two critical phosphorylation sites of Akt1. Translocation of Akt to the cell membrane facilitates PDK1 phosphorylation of the threonine site. The serine site is phosphorylated by mTORC2. Ack1, Src, PTK6, TBK1, IKBKE and IKKε are some of the non-canonical pathways which affect the Akt activity. Protein-protein interactions of Akt to actin and Hsp90 increase the Akt activity while Akt binding to other proteins such as CTMP and TRB3 reduces the Akt activity. The action of Akt on its downstream targets determines its function in cardiovascular processes such as cell survival, growth, proliferation, angiogenesis, vasorelaxation, and cell metabolism. Akt promotes cell survival via caspase-9, YAP, Bcl-2, and Bcl-x activities. Inhibition of FoxO proteins by Akt also increases cell survival by transcriptional mechanisms. Akt stimulates cell growth and proliferation through mTORC1. Akt also increases VEGF secretion and mediates eNOS phosphorylation, vasorelaxation and angiogenesis. Akt can increase cellular metabolism through its downstream targets GSK3 and GLUT4. The alterations of Akt signaling play an important role in many cardiovascular pathological processes such as atherosclerosis, cardiac hypertrophy, and vascular remodeling. Several Akt inhibitors have been developed and tested as anti-tumor agents. They could be potential novel therapeutics for the cardiovascular diseases.
Collapse
Affiliation(s)
- Prasanna Abeyrathna
- Department of Pharmacology & Toxicology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA
| | - Yunchao Su
- Department of Pharmacology & Toxicology, Medical College of Georgia, Georgia Regents University, Augusta, GA 30912, USA.
| |
Collapse
|
71
|
ELABELA Is an Endogenous Growth Factor that Sustains hESC Self-Renewal via the PI3K/AKT Pathway. Cell Stem Cell 2015; 17:435-47. [DOI: 10.1016/j.stem.2015.08.010] [Citation(s) in RCA: 113] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 05/12/2015] [Accepted: 08/12/2015] [Indexed: 12/17/2022]
|
72
|
Maiese K. Stem cell guidance through the mechanistic target of rapamycin. World J Stem Cells 2015; 7:999-1009. [PMID: 26328016 PMCID: PMC4550632 DOI: 10.4252/wjsc.v7.i7.999] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Revised: 06/29/2015] [Accepted: 07/17/2015] [Indexed: 02/06/2023] Open
Abstract
Stem cells offer great promise for the treatment of multiple disorders throughout the body. Critical to this premise is the ability to govern stem cell pluripotency, proliferation, and differentiation. The mechanistic target of rapamycin (mTOR), 289-kDa serine/threonine protein kinase, that is a vital component of mTOR Complex 1 and mTOR Complex 2 represents a critical pathway for the oversight of stem cell maintenance. mTOR can control the programmed cell death pathways of autophagy and apoptosis that can yield variable outcomes in stem cell survival and be reliant upon proliferative pathways that include Wnt signaling, Wnt1 inducible signaling pathway protein 1 (WISP1), silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), and trophic factors. mTOR also is a necessary component for the early development and establishment of stem cells as well as having a significant impact in the regulation of the maturation of specific cell phenotypes. Yet, as a proliferative agent, mTOR can not only foster cancer stem cell development and tumorigenesis, but also mediate cell senescence under certain conditions to limit invasive cancer growth. mTOR offers an exciting target for the oversight of stem cell therapies but requires careful consideration of the diverse clinical outcomes that can be fueled by mTOR signaling pathways.
Collapse
|
73
|
Unacylated ghrelin restores insulin and autophagic signaling in skeletal muscle of diabetic mice. Pflugers Arch 2015; 467:2555-69. [PMID: 26228926 DOI: 10.1007/s00424-015-1721-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Revised: 06/21/2015] [Accepted: 07/13/2015] [Indexed: 01/04/2023]
Abstract
Impairment of insulin signaling in skeletal muscle detrimentally affects insulin-stimulated disposal of glucose. Restoration of insulin signaling in skeletal muscle is important as muscle is one of the major sites for disposal of blood glucose. Recently, unacylated ghrelin (UnAG) has received attention in diabetic research due to its favorable actions on improving glucose tolerance, glycemic control, and insulin sensitivity. The investigation of UnAG has entered phase Ib clinical trial in type 2 diabetes and phase II clinical trial in hyperphagia in Prader-Willi syndrome. Nonetheless, the precise mechanisms responsible for the anti-diabetic actions of UnAG remain incompletely understood. In this study, we examined the effects of UnAG on restoring the impaired insulin signaling in skeletal muscle of db/db diabetic mice. Our results demonstrated that UnAG effectively restored the impaired insulin signaling in diabetic muscle. UnAG decreased insulin receptor substrate (IRS) phosphorylation, increased protein kinase B (Akt) phosphorylation, and, hence, suppressed mTOR signaling. Consequently, UnAG enhanced Glut4 localization and increased PDH activity in the diabetic skeletal muscle. Intriguingly, our data indicated that UnAG normalized the suppressed autophagic signaling in diabetic muscle. In conclusion, our findings illustrated that UnAG restored the impaired insulin and autophagic signaling in skeletal muscle of diabetic mice, which are valuable to understand the underlying mechanisms of the anti-diabetic action of UnAG at peripheral skeletal muscle level.
Collapse
|
74
|
mTOR and post-translational modifications rely on mitochondrion as the arsenal for cellular metabolism regulation. SCIENCE CHINA-LIFE SCIENCES 2015; 58:810-2. [PMID: 26245146 DOI: 10.1007/s11427-015-4909-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Received: 04/26/2015] [Accepted: 06/06/2015] [Indexed: 12/23/2022]
|
75
|
Zhang Q, Cui C, Chen CQ, Hu XL, Liu YH, Fan YH, Meng WH, Zhao QC. Anti-proliferative and pro-apoptotic activities of Alpinia oxyphylla on HepG2 cells through ROS-mediated signaling pathway. JOURNAL OF ETHNOPHARMACOLOGY 2015; 169:99-108. [PMID: 25891473 DOI: 10.1016/j.jep.2015.03.073] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 03/09/2015] [Accepted: 03/13/2015] [Indexed: 06/04/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Fructus Alpiniae oxyphyllae (A. oxyphylla) is a traditional herb which is widely used in East Asian for the treatment of dyspepsia, diarrhea, abdominal pain, poor memory, inflammatory conditions and cancer. MATERIALS AND METHODS The cytotoxic activities of ethanol extract (EE) and five extract layers including petroleum ether (PE), dichloromethane (DCLM), acetoacetate (EtOAc), n-Butanol (n-Bu) and water fractions (WF) of A. oxyphylla were tested on HepG2, SW480, MCF-7, K562 and HUVEC cell lines using MTT assay and LDH release assay. The component analysis was performed on HPLC with gradient elution. Hoechst 33342 staining, DCFH-DA fluorescence microscopy, flow cytometry analysis, western blot and migration assays were carried out to determine the anti-cancer mechanisms of PE. RESULTS MTT analysis showed that EE, PE and DCLM could inhibit cell proliferation on HepG2, SW480, MCF-7, K562 and HUVEC cell lines, especially PE fraction. HPLC analysis pointed out five main components which may contribute to the anti-proliferative activity of PE. Further study showed that PE increased LDH release, induced apoptosis, disrupted mitochondrial membrane potential and elevated intracellular reactive oxygen species (ROS) in HepG2 cells, whereas the antioxidant N-acetyl-l-cysteine (NAC) prevented PE-induced ROS generation. The results of western blot revealed that PE induced apoptosis in HepG2 cells by enhancing Bax/Bcl-2 ratio, increasing cytochrome c in cytosol and activating caspase-3/9. Meanwhile, high levels of ROS could induce DNA damage-mediated protein expression, AKT, ERK inactivation and SAPKs activation. Furthermore, PE conspicuously blocked the migration of HUVEC cells. CONCLUSION The present results demonstrated that PE induced apoptosis in HepG2 cells may be via a ROS-mediated signaling pathway.
Collapse
Affiliation(s)
- Qiao Zhang
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China; Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110840, China
| | - Can Cui
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Cong-Qin Chen
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Xiao-Long Hu
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Ya-Hui Liu
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Yan-Hua Fan
- Department of Pharmacy, Shenyang Pharmaceutical University, Shenyang 110016, China
| | - Wei-Hong Meng
- Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110840, China
| | - Qing-Chun Zhao
- Department of Pharmacy, General Hospital of Shenyang Military Area Command, Shenyang 110840, China.
| |
Collapse
|
76
|
New Insights for Oxidative Stress and Diabetes Mellitus. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:875961. [PMID: 26064426 PMCID: PMC4443788 DOI: 10.1155/2015/875961] [Citation(s) in RCA: 149] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Accepted: 04/15/2015] [Indexed: 12/12/2022]
Abstract
The release of reactive oxygen species (ROS) and the generation of oxidative stress are considered critical factors for the pathogenesis of diabetes mellitus (DM), a disorder that is growing in prevalence and results in significant economic loss. New therapeutic directions that address the detrimental effects of oxidative stress may be especially warranted to develop effective care for the millions of individuals that currently suffer from DM. The mechanistic target of rapamycin (mTOR), silent mating type information regulation 2 homolog 1 (S. cerevisiae) (SIRT1), and Wnt1 inducible signaling pathway protein 1 (WISP1) are especially justified to be considered treatment targets for DM since these pathways can address the complex relationship between stem cells, trophic factors, impaired glucose tolerance, programmed cell death pathways of apoptosis and autophagy, tissue remodeling, cellular energy homeostasis, and vascular biology that greatly impact the biology and disease progression of DM. The translation and development of these pathways into viable therapies will require detailed understanding of their proliferative nature to maximize clinical efficacy and limit adverse effects that have the potential to lead to unintended consequences.
Collapse
|
77
|
Malla R, Wang Y, Chan WK, Tiwari AK, Faridi JS. Genetic ablation of PRAS40 improves glucose homeostasis via linking the AKT and mTOR pathways. Biochem Pharmacol 2015; 96:65-75. [PMID: 25931147 DOI: 10.1016/j.bcp.2015.04.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2015] [Accepted: 04/23/2015] [Indexed: 12/22/2022]
Abstract
Alterations in PI3K-AKT-mTOR signaling have been implicated in diabetes. This study assessed whether disruption of PRAS40, a substrate of AKT and component of mTORC1, would alter glucose homeostasis and prevent hyperglycemia in the streptozotocin (STZ)-induced diabetes mouse model. PRAS40 ablation resulted in a mild lowering of blood glucose levels and glycated hemoglobin (HbA1C), a lowered insulin requirement, and improved glucose tolerance in untreated PRAS40 gene knockout (PRAS40(-/-)) as compared to wild-type (PRAS40(+/+)) mice. Diabetes was then induced in these mice using STZ at 50mg/kg/day over five days. Following STZ-treatment, PRAS40(-/-) mice exhibited significantly lower blood glucose and HbA1C levels than PRAS40(+/+) mice. Liver tissue of PRAS40(-/-) mice and shPRAS40 Hep3B cells showed increased activation of AKT (p-AKT T308) and mTORC1 (p-p70S6K) signaling as well as decreased p-AKT (S473) and increased p-IRS1 (S612) protein levels. Altered tissue gene expression of several glucose transporters (GLUT) and increased hepatic GLUT4 protein levels were observed in PRAS40(-/-) as compared to PRAS40(+/+) mice. In summary, PRAS40 deletion significantly attenuates hyperglycemia in STZ-induced PRAS40(-/-) mice through increased hepatic AKT and mTORC1 signaling, a lowered serum insulin requirement, and altered hepatic GLUT4 levels.
Collapse
Affiliation(s)
- Ritu Malla
- Department of Physiology and Pharmacology, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Yu Wang
- Department of Pharmaceutics and Medicinal Chemistry, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - William K Chan
- Department of Pharmaceutics and Medicinal Chemistry, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States
| | - Amit K Tiwari
- Department of Pharmacology and Experimental Therapeutics, College of Pharmacy & Pharmaceutical Sciences, University of Toledo, OH, United States
| | - Jesika S Faridi
- Department of Physiology and Pharmacology, T. J. Long School of Pharmacy & Health Sciences, University of the Pacific, Stockton, CA, United States.
| |
Collapse
|
78
|
Veliça P, Zech M, Henson S, Holler A, Manzo T, Pike R, Santos E Sousa P, Zhang L, Heinz N, Schiedlmeier B, Pule M, Stauss H, Chakraverty R. Genetic Regulation of Fate Decisions in Therapeutic T Cells to Enhance Tumor Protection and Memory Formation. Cancer Res 2015; 75:2641-52. [PMID: 25904681 DOI: 10.1158/0008-5472.can-14-3283] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/26/2015] [Indexed: 11/16/2022]
Abstract
A key challenge in the field of T-cell immunotherapy for cancer is creating a suitable platform for promoting differentiation of effector cells while at the same time enabling self-renewal needed for long-term memory. Although transfer of less differentiated memory T cells increases efficacy through greater expansion and persistence in vivo, the capacity of such cells to sustain effector functions within immunosuppressive tumor microenvironments may still be limiting. We have therefore directly compared the impact of effector versus memory differentiation of therapeutic T cells in tumor-bearing mice by introducing molecular switches that regulate cell fate decisions via mTOR. Ectopic expression of RAS homolog enriched in brain (RHEB) increased mTORC1 signaling, promoted a switch to aerobic glycolysis, and increased expansion of effector T cells. By rapidly infiltrating tumors, RHEB-transduced T cells significantly reduced the emergence of immunoedited escape variants. In contrast, expression of proline-rich Akt substrate of 40 kDa (PRAS40) inhibited mTORC1, promoted quiescence, and blocked tumor infiltration. Fate mapping studies following transient expression of PRAS40 demonstrated that mTORC1(low) T cells made no contribution to initial tumor control but instead survived to become memory cells proficient in generating recall immunity. Our data support the design of translational strategies for generating heterogeneous T-cell immunity against cancer, with the appropriate balance between promoting effector differentiation and self-renewal. Unlike pharmacologic inhibitors, the genetic approach described here allows for upregulation as well as inhibition of the mTORC1 pathway and is highly selective for the therapeutic T cells without affecting systemic mTORC1 functions.
Collapse
Affiliation(s)
- Pedro Veliça
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom. Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Mathias Zech
- Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Sian Henson
- Division of Infection and Immunity, University College London, London, United Kingdom
| | - Angelika Holler
- Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Teresa Manzo
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom. Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Rebecca Pike
- Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Pedro Santos E Sousa
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom. Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Lei Zhang
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom. Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | | | | | - Martin Pule
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom
| | - Hans Stauss
- Institute of Immunity and Transplantation, University College London, London, United Kingdom
| | - Ronjon Chakraverty
- Department of Haematology, Cancer Institute, University College London, London, United Kingdom. Institute of Immunity and Transplantation, University College London, London, United Kingdom.
| |
Collapse
|
79
|
Steiner JL, Gordon BS, Lang CH. Moderate alcohol consumption does not impair overload-induced muscle hypertrophy and protein synthesis. Physiol Rep 2015; 3:3/3/e12333. [PMID: 25780086 PMCID: PMC4393167 DOI: 10.14814/phy2.12333] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Chronic alcohol consumption leads to muscle weakness and atrophy in part by suppressing protein synthesis and mTORC1-mediated signaling. However, it is unknown whether moderate alcohol consumption also prevents overload-induced muscle growth and related anabolic signaling. Hypertrophy of the plantaris muscle was induced by removal of a section of the gastrocnemius and soleus muscles from one leg of C57BL/6 adult male mice while the contralateral leg remained intact as the sham control. A nutritionally complete alcohol-containing liquid diet (EtOH) or isocaloric, alcohol-free liquid diet (Con) was provided for 14 days post-surgery. EtOH intake was increased progressively (day 1-5) before being maintained at ~20 g/day/kg BW. The plantaris muscle from the sham and OL leg was removed after 14 days at which time there was no difference in body weight between Con and EtOH-fed mice. OL increased muscle weight (90%) and protein synthesis (125%) in both Con and EtOH mice. The overload-induced increase in mTOR (Ser2448), 4E-BP1 (Thr37/46), S6K1 (Thr389), rpS6 (Ser240/244), and eEF2 (Thr56) were comparable in muscle from Con and EtOH mice. Modulation of signaling upstream of mTORC1 including REDD1 protein expression, Akt (Thr308), PRAS40 (Thr246), and ERK (Thr202/Tyr204) also did not differ between Con and EtOH mice. Markers of autophagy (ULK1, p62, and LC3) suggested inhibition of autophagy with overload and activation with alcohol feeding. These data show that moderate alcohol consumption does not impair muscle growth, and therefore imply that resistance exercise may be an effective therapeutic modality for alcoholic-related muscle disease.
Collapse
Affiliation(s)
- Jennifer L Steiner
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Bradley S Gordon
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| | - Charles H Lang
- Department of Cellular and Molecular Physiology, Penn State College of Medicine, Hershey, Pennsylvania
| |
Collapse
|
80
|
Maiese K. mTOR: Driving apoptosis and autophagy for neurocardiac complications of diabetes mellitus. World J Diabetes 2015; 6:217-224. [PMID: 25789103 PMCID: PMC4360415 DOI: 10.4239/wjd.v6.i2.217] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 12/10/2014] [Accepted: 01/19/2015] [Indexed: 02/05/2023] Open
Abstract
The World Health Organization estimates that diabetes mellitus (DM) will become the seventh leading cause of death during the next two decades. DM affects approximately 350 million individuals worldwide and additional millions that remain undiagnosed are estimated to suffer from the complications of DM. Although the complications of DM can be seen throughout the body, the nervous, cardiac, and vascular systems can be significantly affected and lead to disorders that include cognitive loss, stroke, atherosclerosis, cardiac failure, and endothelial stem cell impairment. At the cellular level, oxidative stress is a significant determinant of cell fate during DM and leads to endoplasmic reticulum stress, mitochondrial dysfunction, apoptosis, and autophagy. Multiple strategies are being developed to combat the complications of DM, but it is the mechanistic target of rapamycin (mTOR) that is gaining interest in drug development circles especially for protective therapies that involve cytokines and growth factors such as erythropoietin. The pathways of mTOR linked to mTOR complex 1, mTOR complex 2, AMP activated protein kinase, and the hamartin (tuberous sclerosis 1)/tuberin (tuberous sclerosis 2) complex can ultimately influence neuronal, cardiac, and vascular cell survival during oxidant stress in DM through a fine interplay between apoptosis and autophagy. Further understanding of these mTOR regulated pathways should foster novel strategies for the complications of DM that impact millions of individuals with death and disability.
Collapse
|
81
|
Maiese K. Programming apoptosis and autophagy with novel approaches for diabetes mellitus. Curr Neurovasc Res 2015; 12:173-88. [PMID: 25742566 PMCID: PMC4380829 DOI: 10.2174/1567202612666150305110929] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 02/16/2015] [Accepted: 02/19/2015] [Indexed: 12/13/2022]
Abstract
According to the World Health Organization, diabetes mellitus (DM) in the year 2030 will be ranked the seventh leading cause of death in the world. DM impacts all systems of the body with oxidant stress controlling cell fate through endoplasmic reticulum stress, mitochondrial dysfunction, alterations in uncoupling proteins, and the induction of apoptosis and autophagy. Multiple treatment approaches are being entertained for DM with Wnt1 inducible signaling pathway protein 1 (WISP1), mechanistic target of rapamycin (mTOR), and silent mating type information regulation 2 homolog) 1 (S. cerevisiae) (SIRT1) generating significant interest as target pathways that can address maintenance of glucose homeostasis as well as prevention of cellular pathology by controlling insulin resistance, stem cell proliferation, and the programmed cell death pathways of apoptosis and autophagy. WISP1, mTOR, and SIRT1 can rely upon similar pathways such as AMP activated protein kinase as well as govern cellular metabolism through cytokines such as EPO and oral hypoglycemics such as metformin. Yet, these pathways require precise biological control to exclude potentially detrimental clinical outcomes. Further elucidation of the ability to translate the roles of WISP1, mTOR, and SIRT1 into effective clinical avenues offers compelling prospects for new therapies against DM that can benefit hundreds of millions of individuals throughout the globe.
Collapse
Affiliation(s)
- Kenneth Maiese
- MD, Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
| |
Collapse
|
82
|
Maiese K. Cutting through the complexities of mTOR for the treatment of stroke. Curr Neurovasc Res 2014; 11:177-86. [PMID: 24712647 DOI: 10.2174/1567202611666140408104831] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 01/06/2023]
Abstract
On a global basis, at least 15 million individuals suffer some form of a stroke every year. Of these individuals, approximately 800,000 of these cerebrovascular events occur in the United States (US) alone. The incidence of stroke in the US has declined from the third leading cause of death to the fourth, a result that can be attributed to multiple factors that include improved vascular disease management, reduced tobacco use, and more rapid time to treatment in patients that are clinically appropriate to receive recombinant tissue plasminogen activator. However, treatment strategies for the majority of stroke patients are extremely limited and represent a critical void for care. A number of new therapeutic considerations for stroke are under consideration, but it is the mammalian target of rapamycin (mTOR) that is receiving intense focus as a potential new target for cerebrovascular disease. As part of the phosphoinositide 3-kinase (PI 3-K) and protein kinase B (Akt) cascade, mTOR is an essential component of mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) to govern cell death involving apoptosis, autophagy, and necroptosis, cellular metabolism, and gene transcription. Vital for the consideration of new therapeutic strategies for stroke is the ability to understand how the intricate and complex pathways of mTOR signaling sometimes lead to disparate clinical outcomes.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, Newark, New Jersey 07101, USA.
| |
Collapse
|
83
|
Abstract
A significant portion of the world's population suffers from sporadic Alzheimer's disease (AD) with available present therapies limited to symptomatic care that does not alter disease progression. Over the next decade, advancing age of the global population will dramatically increase the incidence of AD and severely impact health care resources, necessitating novel, safe, and efficacious strategies for AD. The mammalian target of rapamycin (mTOR) and its protein complexes mTOR Complex 1 (mTORC1) and mTOR Complex 2 (mTORC2) offer exciting and unique avenues of intervention for AD through the oversight of programmed cell death pathways of apoptosis, autophagy, and necroptosis. mTOR modulates multi-faceted signal transduction pathways that involve phosphoinositide 3-kinase (PI 3-K), protein kinase B (Akt), hamartin (tuberous sclerosis 1)/ tuberin (tuberous sclerosis 2) (TSC1/TSC2) complex, proline-rich Akt substrate 40 kDa (PRAS40), and p70 ribosomal S6 kinase (p70S6K) and can interface with the neuroprotective pathways of growth factors, sirtuins, wingless, forkhead transcription factors, and glycogen synthase kinase-3β. With the ability of mTOR to broadly impact cellular function, clinical strategies for AD that implement mTOR must achieve parallel objectives of protecting neuronal, vascular, and immune cell survival in conjunction with preserving networks that determine memory and cognitive function.
Collapse
Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling , Newark, New Jersey 07101 , USA
| |
Collapse
|
84
|
Mechanistic elucidation of apoptosis and cell cycle arrest induced by 5-hydroxymethylfurfural, the important role of ROS-mediated signaling pathways. Food Res Int 2014. [DOI: 10.1016/j.foodres.2014.08.051] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
85
|
Yuan K, Wu H, Wang Y, Chen H, Jiao M, Fu R. Phospho-PRAS40 Thr246 predicts trastuzumab response in patients with HER2-positive metastatic breast cancer. Oncol Lett 2014; 9:785-789. [PMID: 25621052 PMCID: PMC4301480 DOI: 10.3892/ol.2014.2744] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2014] [Accepted: 10/22/2014] [Indexed: 11/15/2022] Open
Abstract
Resistance to trastuzumab is frequently observed during the treatment of patients with human epidermal growth factor 2 (HER2)-positive metastatic breast cancers. The aim of the present study was to determine if the phosphorylated proline-rich Akt substrate of 40 kDa (phospho-PRAS40Thr246), a novel biomarker for phosphoinositol-3 kinase (PI3K) pathway activation, could predict the response of HER2-positive metastatic breast cancers to treatment with trastuzumab. Formalin-fixed, paraffin-embedded tumor tissue samples were retrospectively collected from 55 trastuzumab-treated patients. Next, the expression of phospho-PRAS40Thr246 and phosphatase and tensin homolog (PTEN) was assessed by immunohistochemistry. In total, five common phosphoinositol-3 kinase α catalytic subunit mutations, namely E542K, E545K, E545D, H1047R and H1047L, were identified by the amplification-refractory mutation system, using the allele-specific polymerase chain reaction. The activation of the PI3K pathway, as determined by low PTEN expression or the presence of oncogenic PIK3CA mutations, was observed in 49.1% (27 cases) of the 55 HER2-positive metastatic breast cancer tissues. In total, 40% of the tumors were defined as being phospho-PRAS40Thr246-positive. Furthermore, the results revealed that phospho-PRAS40Thr246 expression was associated with the PI3K pathway activation status and an increased risk of tumor progression in HER2-positive metastatic breast cancer patients who had received trastuzumab-based therapy. Therefore, phospho-PRAS40Thr246 expression levels may reflect the PI3K pathway activation status and act as a biomarker for HER2-amplified breast cancer patients who are unlikely to respond to trastuzumab-based therapy.
Collapse
Affiliation(s)
- Kai Yuan
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Hongyan Wu
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Yulong Wang
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Hongqiang Chen
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Mingwen Jiao
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| | - Rongzhan Fu
- Department of Breast Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan, Shandong 250014, P.R. China
| |
Collapse
|
86
|
Castorena CM, Arias EB, Sharma N, Cartee GD. Effects of a brief high-fat diet and acute exercise on the mTORC1 and IKK/NF-κB pathways in rat skeletal muscle. Appl Physiol Nutr Metab 2014; 40:251-62. [PMID: 25706655 DOI: 10.1139/apnm-2014-0412] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
One exercise session can improve subsequent insulin-stimulated glucose uptake by skeletal muscle in healthy and insulin-resistant individuals. Our first aim was to determine whether a brief (2 weeks) high-fat diet (HFD) that caused muscle insulin resistance would activate the mammalian target of rapamycin complex 1 (mTORC1) and/or inhibitor of κB kinase/nuclear factor κB (IKK/NF-κB) pathways, which are potentially linked to induction of insulin resistance. Our second aim was to determine whether acute exercise that improved insulin-stimulated glucose uptake by muscles would attenuate activation of these pathways. We compared HFD-fed rats with rats fed a low-fat diet (LFD). Some animals from each diet group were sedentary and others were studied 3 h postexercise, when insulin-stimulated glucose uptake was increased. The results did not provide evidence that brief HFD activated either the mTORC1 (including phosphorylation of mTOR(Ser2448), TSC2(Ser939), p70S6K(Thr412), and RPS6(Ser235/236)) or the IKK/NF-κB (including abundance of IκBα or phosphorylation of NF-κB(Ser536), IKKα/β(Ser177/181), and IκB(Ser32)) pathway in insulin-resistant muscles. Exercise did not oppose the activation of either pathway, as evidenced by no attenuation of phosphorylation of key proteins in the IKK/NF-κB pathway (NF-κB(Ser536), IKKα/β(Ser177/181), and IκB(Ser32)), unaltered IκBα abundance, and no attenuation of phosphorylation of key proteins in the mTORC1 pathway (mTOR(Ser2448), TSC2(Ser939), and RPS6(Ser235/236)). Instead, exercise induced greater phosphorylation of 2 proteins of the mTORC1 pathway (PRAS40(Thr246) and p70S6K(Thr412)) in insulin-stimulated muscles, regardless of diet. Insulin resistance induced by a brief HFD was not attributable to greater activation of the mTORC1 or the IKK/NF-κB pathway in muscle, and exercise-induced improvement in insulin sensitivity was not attributable to attenuated activation of these pathways in muscle.
Collapse
Affiliation(s)
- Carlos M Castorena
- Muscle Biology Laboratory, School of Kinesiology, University of Michigan, Ann Arbor, MI 48109-2214, USA
| | | | | | | |
Collapse
|
87
|
Golberg ND, Druzhevskaya AM, Rogozkin VA, Ahmetov II. Role of mTOR in the regulation of skeletal muscle metabolism. ACTA ACUST UNITED AC 2014. [DOI: 10.1134/s0362119714040070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
88
|
Zhao YY, Tian Y, Zhang J, Xu F, Yang YP, Huang Y, Zhao HY, Zhang JW, Xue C, Lam MH, Yan L, Hu ZH, Dinglin XX, Zhang L. Effects of an oral allosteric AKT inhibitor (MK-2206) on human nasopharyngeal cancer in vitro and in vivo. DRUG DESIGN DEVELOPMENT AND THERAPY 2014; 8:1827-37. [PMID: 25336925 PMCID: PMC4199975 DOI: 10.2147/dddt.s67961] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Aim Protein kinase B (AKT) signaling frequently is deregulated in human cancers and plays an important role in nasopharyngeal carcinoma (NPC). This preclinical study investigated the effect of MK-2206, a potent allosteric AKT inhibitor, on human NPC cells in vitro and in vivo. Methods The effect of MK-2206 on the growth and proliferation of CNE-1, CNE-2, HONE-1, and SUNE-1 cells was assessed by Cell Counting Kit 8 and colony formation assay. Flow cytometry was performed to analyze cell cycle and apoptosis. The effects of MK-2206 on the AKT pathway were analyzed by Western blotting. Autophagy induction was evaluated via electron microscopy and Western blot. To test the effects of MK-2206 in vivo, CNE-2 cells were subcutaneously implanted into nude mice. Tumor-bearing mice were treated orally with MK-2206 or placebo. Tumors were harvested for immunohistochemical analysis. Results In vitro, MK-2206 inhibited the four NPC cell line growths and reduced the sizes of the colonies in a dose-dependent manner. At 72 and 96 hours, the half maximal inhibitory concentration (IC50) values of MK-2206 in CNE-1, CNE-2, and HONE-1 cell lines were 3–5 μM, whereas in SUNE-1, IC50 was less than 1 μM, and MK-2206 induced cell cycle arrest at the G1 phase. However, our study found no evidence of apoptosis. MK-2206 induced autophagy in NPC cells, as evidenced by electron microscopy and Western blot, and inhibited the growth of tumors that were subcutaneously implanted in mice. Inhibition of downstream phosphorylation through the PRAS40 and S6 pathways seems to be the main mechanism for the MK-2206-induced growth inhibition. Conclusion Our preclinical study suggests that MK-2206’s antiproliferative effect may be useful for NPC treatment; however, strategies for reinforcing this effect are needed to maximize clinical benefit.
Collapse
Affiliation(s)
- Yuan-Yuan Zhao
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Ying Tian
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Jing Zhang
- Department of Medical Oncology, the First Affiliated Hospital of Guang Zhou Traditional Chinese Medicine University, Guangzhou, People's Republic of China
| | - Fei Xu
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Yun-Peng Yang
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Yan Huang
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Hong-Yun Zhao
- National Anti-Cancer Drug Research Centre, Sun Yat-Sen University Cancer Center; State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Jian-Wei Zhang
- The Six Affiliated Hospital of Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Cong Xue
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | | | - Li Yan
- Merck and Co Inc, North Wales, PA USA
| | - Zhi-Huang Hu
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| | - Xiao-Xiao Dinglin
- Sun Yat-Sen Memorial Hospital, Guangzhou, People's Republic of China
| | - Li Zhang
- Department of Medical Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China ; National Anti-Cancer Drug Research Centre, Sun Yat-Sen University Cancer Center; State Key Laboratory of Oncology in South China, and Collaborative Innovation Center for Cancer Medicine, Guangzhou, People's Republic of China
| |
Collapse
|
89
|
Chingozha L, Zhan M, Zhu C, Lu H. A generalizable, tunable microfluidic platform for delivering fast temporally varying chemical signals to probe single-cell response dynamics. Anal Chem 2014; 86:10138-47. [PMID: 25254360 PMCID: PMC4204904 DOI: 10.1021/ac5019843] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
![]()
Understanding how biological systems
transduce dynamic, soluble
chemical cues into physiological processes requires robust experimental
tools for generating diverse temporal chemical patterns. The advent
of microfluidics has seen the development of platforms for rapid fluid
exchange allowing ease of changes in the cellular microenvironment
and precise cell handling. Rapid exchange is important for exposing
systems to temporally varying signals. However, direct coupling of
macroscale fluid flow with microstructures is potentially problematic
due to the high shear stresses that inevitably add confounding mechanical
perturbation effects to the biological system of interest. Here, we
have devised a method of translating fast and precise macroscale flows
to microscale flows using a monolithically integrated perforated membrane.
We integrated a high-density cell trap array for nonadherent cells
that are challenging to handle under flow conditions with a soluble
chemical signal generator module. The platform enables fast and repeatable
switching of stimulus and buffer at low shear stresses for quantitative
live, single-cell fluorescent studies. This modular design allows
facile integration of any cell-handling chip design with any chemical
delivery module. We demonstrate the utility of this device by characterizing
heterogeneity of oscillatory response for cells exposed to alternating
Ca2+ waveforms at various periodicities. This platform
enables the analysis of cell responses to chemical perturbations at
a single-cell resolution that is necessary in understanding signal
transduction pathways.
Collapse
Affiliation(s)
- Loice Chingozha
- School of Chemical & Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | | | | | | |
Collapse
|
90
|
Huang H, Densmore D. Integration of microfluidics into the synthetic biology design flow. LAB ON A CHIP 2014; 14:3459-74. [PMID: 25012162 DOI: 10.1039/c4lc00509k] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
One goal of synthetic biology is to design and build genetic circuits in living cells for a range of applications. Major challenges in these efforts include increasing the scalability and robustness of engineered biological systems and streamlining and automating the synthetic biology workflow of specification-design-assembly-verification. We present here a summary of the advances in microfluidic technology, particularly microfluidic large scale integration, that can be used to address the challenges facing each step of the synthetic biology workflow. Microfluidic technologies allow precise control over the flow of biological content within microscale devices, and thus may provide more reliable and scalable construction of synthetic biological systems. The integration of microfluidics and synthetic biology has the capability to produce rapid prototyping platforms for characterization of genetic devices, testing of biotherapeutics, and development of biosensors.
Collapse
Affiliation(s)
- Haiyao Huang
- Department of Electrical and Computer Engineering, Boston University, Boston, MA 02215, USA.
| | | |
Collapse
|
91
|
T-cell co-stimulation through the CD2 and CD28 co-receptors induces distinct signalling responses. Biochem J 2014; 460:399-410. [PMID: 24665965 DOI: 10.1042/bj20140040] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Full T-cell activation critically depends on the engagement of the TCR (T-cell receptor) in conjunction with a second signal by co-stimulatory receptors that boost the immune response. In the present study we have compared signalling patterns induced by the two co-receptors CD2 and CD28 in human peripheral blood T-cells. These co-receptors were previously suggested to be redundant in function. By a combination of multi-parameter phosphoflow cytometry, phosphokinase arrays and Western blot analyses, we demonstrate that CD2 co-stimulation induces phosphorylation of the TCR-proximal signalling complex, whereas CD28 activates distal signalling molecules, including the transcription factors NF-κB (nuclear factor κB), ATF (activating transcription factor)-2, STAT3/5 (signal transducer and activator of transcription 3/5), p53 and c-Jun. These signalling patterns were conserved in both naïve and effector/memory T-cell subsets. We show that free intracellular Ca(2+) and signalling through the PI3K (phosphoinositide 3-kinase)/Akt pathway are required for proper CD28-induced NF-κB activation. The signalling patterns induced by CD2 and CD28 co-stimulation lead to distinct functional immune responses in T-cell proliferation and cytokine production. In conclusion, CD2 and CD28 co-stimulation induces distinct signalling responses and functional outcomes in T-cells.
Collapse
|
92
|
Knoch F, Tarantola M, Bodenschatz E, Rappel WJ. Modeling self-organized spatio-temporal patterns of PIP₃ and PTEN during spontaneous cell polarization. Phys Biol 2014; 11:046002. [PMID: 25024302 DOI: 10.1088/1478-3975/11/4/046002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During spontaneous cell polarization of Dictyostelium discoideum cells, phosphatidylinositol (3,4,5)-triphoshpate (PIP3) and PTEN (phosphatase tensin homolog) have been identified as key signaling molecules which govern the process of polarization in a self-organized manner. Recent experiments have quantified the spatio-temporal dynamics of these signaling components. Surprisingly, it was found that membrane-bound PTEN can be either in a high or low state, that PIP3 waves were initiated in areas lacking PTEN through an excitable mechanism, and that PIP3 was degraded even though the PTEN concentration remained low. Here we develop a reaction-diffusion model that aims to explain these experimental findings. Our model contains bistable dynamics for PTEN, excitable dynamics for PIP3, and postulates the existence of two species of PTEN with different dephosphorylation rates. We show that our model is able to produce results that are in good qualitative agreement with the experiments, suggesting that our reaction-diffusion model underlies the self-organized spatio-temporal patterns observed in experiments.
Collapse
Affiliation(s)
- Fabian Knoch
- Max Planck Institute for Dynamics and Self-Organization, D-37077 Göttingen, Germany
| | | | | | | |
Collapse
|
93
|
Shipitsin M, Small C, Giladi E, Siddiqui S, Choudhury S, Hussain S, Huang YE, Chang H, Rimm DL, Berman DM, Nifong TP, Blume-Jensen P. Automated quantitative multiplex immunofluorescence in situ imaging identifies phospho-S6 and phospho-PRAS40 as predictive protein biomarkers for prostate cancer lethality. Proteome Sci 2014; 12:40. [PMID: 25075204 PMCID: PMC4114438 DOI: 10.1186/1477-5956-12-40] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Accepted: 06/18/2014] [Indexed: 11/10/2022] Open
Abstract
Background We have witnessed significant progress in gene-based approaches to cancer prognostication, promising early intervention for high-risk patients and avoidance of overtreatment for low-risk patients. However, there has been less advancement in protein-based approaches, even though perturbed protein levels and post-translational modifications are more directly linked with phenotype. Most current, gene expression-based platforms require tissue lysis resulting in loss of structural and molecular information, and hence are blind to tumor heterogeneity and morphological features. Results Here we report an automated, integrated multiplex immunofluorescence in situ imaging approach that quantitatively measures protein biomarker levels and activity states in defined intact tissue regions where the biomarkers of interest exert their phenotype. Using this approach, we confirm that four previously reported prognostic markers, PTEN, SMAD4, CCND1 and SPP1, can predict lethal outcome of human prostate cancer. Furthermore, we show that two PI3K pathway-regulated protein activities, pS6 (RPS6-phosphoserines 235/236) and pPRAS40 (AKT1S1-phosphothreonine 246), correlate with prostate cancer lethal outcome as well (individual marker hazard ratios of 2.04 and 2.03, respectively). Finally, we incorporate these 2 markers into a novel 5-marker protein signature, SMAD4, CCND1, SPP1, pS6, and pPRAS40, which is highly predictive for prostate cancer-specific death. The ability to substitute PTEN with phospho-markers demonstrates the potential of quantitative protein activity state measurements on intact tissue. Conclusions In summary, our approach can reproducibly and simultaneously quantify and assess multiple protein levels and functional activities on intact tissue specimens. We believe it is broadly applicable to not only cancer but other diseases, and propose that it should be well suited for prognostication at early stages of pathogenesis where key signaling protein levels and activities are perturbed.
Collapse
Affiliation(s)
| | | | - Eldar Giladi
- Metamark Genetics Inc, Cambridge, MA, USA ; Current address: Atreca, San Carlos, CA, USA
| | - Summar Siddiqui
- Metamark Genetics Inc, Cambridge, MA, USA ; Current address: Moderna, Cambridge, MA, USA
| | | | | | - Yi E Huang
- Metamark Genetics Inc, Cambridge, MA, USA
| | - Hua Chang
- Metamark Genetics Inc, Cambridge, MA, USA
| | - David L Rimm
- Department of Pathology, Yale University Medical School, New Haven, CT, USA
| | - David M Berman
- Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada
| | | | - Peter Blume-Jensen
- Metamark Genetics Inc, Cambridge, MA, USA ; Current address: XTuit Pharmaceuticals, Inc, Cambridge, MA, USA
| |
Collapse
|
94
|
An Excitable Compass Guides Chemotaxis? Biophys J 2014; 106:989-90. [DOI: 10.1016/j.bpj.2014.01.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2013] [Accepted: 01/23/2014] [Indexed: 11/22/2022] Open
|
95
|
Workman JJ, Chen H, Laribee RN. Environmental signaling through the mechanistic target of rapamycin complex 1: mTORC1 goes nuclear. Cell Cycle 2014; 13:714-25. [PMID: 24526113 PMCID: PMC3979908 DOI: 10.4161/cc.28112] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Mechanistic target of rapamycin complex 1 (mTORC1) is a well-known regulator of cell growth and proliferation in response to environmental stimuli and stressors. To date, the majority of mTORC1 studies have focused on its function as a cytoplasmic effector of translation regulation. However, recent studies have identified additional, nuclear-specific roles for mTORC1 signaling related to transcription of the ribosomal DNA (rDNA) and ribosomal protein (RP) genes, mitotic cell cycle control, and the regulation of epigenetic processes. As this area of study is still in its infancy, the purpose of this review to highlight these significant findings and discuss the relevance of nuclear mTORC1 signaling dysregulation as it pertains to health and disease.
Collapse
Affiliation(s)
- Jason J Workman
- Department of Pathology and Laboratory Medicine and Center for Cancer Research; University of Tennessee Health Science Center; Memphis, TN USA
| | - Hongfeng Chen
- Department of Pathology and Laboratory Medicine and Center for Cancer Research; University of Tennessee Health Science Center; Memphis, TN USA
| | - R Nicholas Laribee
- Department of Pathology and Laboratory Medicine and Center for Cancer Research; University of Tennessee Health Science Center; Memphis, TN USA
| |
Collapse
|
96
|
Abstract
Noise permeates biology on all levels, from the most basic molecular, sub-cellular processes to the dynamics of tissues, organs, organisms and populations. The functional roles of noise in biological processes can vary greatly. Along with standard, entropy-increasing effects of producing random mutations, diversifying phenotypes in isogenic populations, limiting information capacity of signaling relays, it occasionally plays more surprising constructive roles by accelerating the pace of evolution, providing selective advantage in dynamic environments, enhancing intracellular transport of biomolecules and increasing information capacity of signaling pathways. This short review covers the recent progress in understanding mechanisms and effects of fluctuations in biological systems of different scales and the basic approaches to their mathematical modeling.
Collapse
Affiliation(s)
- Lev S. Tsimring
- BioCircuits Institute, University of California, San Diego, 9500 Gilman Dr., La Jolla, CA 92093-0328, USA
| |
Collapse
|
97
|
Shang YC, Chong ZZ, Wang S, Maiese K. Wnt1 inducible signaling pathway protein 1 (WISP1) targets PRAS40 to govern β-amyloid apoptotic injury of microglia. Curr Neurovasc Res 2013; 9:239-49. [PMID: 22873724 DOI: 10.2174/156720212803530618] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Revised: 07/25/2012] [Accepted: 07/30/2012] [Indexed: 12/21/2022]
Abstract
Given the present challenges to attain effective treatment for β-amyloid (Aβ) toxicity in neurodegenerative disorders such as Alzheimer's disease, development of novel cytoprotective pathways that can assist immune mediated therapies through the preservation of central nervous system microglia could offer significant promise. We show that the CCN4 protein, Wnt1 inducible signaling pathway protein 1 (WISP1), is initially up-regulated by Aβ and can modulate its endogenous expression for the protection of microglia during Aβ mediated apoptosis. WISP1 activates mTOR and phosphorylates p70S6K and 4EBP1 through the control of the regulatory mTOR component PRAS40. Loss of PRAS40 through gene reduction or inhibition by WISP1 is cytoprotective. WISP1 ultimately governs PRAS40 by sequestering PRAS40 intracellularly through post-translational phosphorylation and binding to protein 14-3-3. Our work identifies WISP1, mTOR signaling, and PRAS40 as targets for new strategies directed against Alzheimer's disease and related disorders.
Collapse
Affiliation(s)
- Yan Chen Shang
- Laboratory of Cellular and Molecular Signaling, Cancer Center, F 1220, New Jersey Health Sciences University, 205 South Orange Avenue, Newark, NJ 07101, USA
| | | | | | | |
Collapse
|
98
|
Abstract
Neuroblastoma (NB) is the most common extracranial malignant solid tumors of childhood, and the majority of these high-risk tumors is resistant to nearly all the treatments and has a significantly worse outcome. The mammalian target of rapamycin (mTOR) plays a critical role in oncogenesis and cancer progression of many tumors. This review will describe the function of mTOR, its genetic regulation in pediatric neuroblastoma, and its value as a target for inhibition by anticancer agents for patients with NB.
Collapse
Affiliation(s)
- Hong Mei
- 1Department of Pediatric Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | | | | | | |
Collapse
|
99
|
Ogasawara R, Sato K, Higashida K, Nakazato K, Fujita S. Ursolic acid stimulates mTORC1 signaling after resistance exercise in rat skeletal muscle. Am J Physiol Endocrinol Metab 2013; 305:E760-5. [PMID: 23900420 DOI: 10.1152/ajpendo.00302.2013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
A recent study identified ursolic acid (UA) as a potent stimulator of muscle protein anabolism via PI3K/Akt signaling, thereby suggesting that UA can increase Akt-independent mTOR complex 1 (mTORC1) activation induced by resistance exercise via Akt signaling. The purpose of the present study was to investigate the effect of UA on resistance exercise-induced mTORC1 activation. The right gastrocnemius muscle of male Sprague-Dawley rats aged 11 wk was isometrically exercised via percutaneous electrical stimulation (stimulating ten 3-s contractions per set for 5 sets), while the left gastrocnemius muscle served as the control. UA or placebo (PLA; corn oil only) was injected intraperitoneally immediately after exercise. The rats were killed 1 or 6 h after the completion of exercise and the target tissues removed immediately. With placebo injection, the phosphorylation of p70(S6K) at Thr(389) increased 1 h after resistance exercise but attenuated to the control levels 6 h after the exercise. On the other hand, the augmented phosphorylation of p70(S6K) was maintained even 6 h after exercise when UA was injected immediately after exercise. A similar trend of prolonged phosphorylation was observed in PRAS40 Thr(246), whereas UA alone or resistance exercise alone did not alter its phosphorylation level at 6 h after intervention. These results indicate that UA is able to sustain resistance exercise-induced mTORC1 activity.
Collapse
Affiliation(s)
- Riki Ogasawara
- The Research Organization of Science and Technology, Ritsumeikan University, Kusatsu, Shiga, Japan
| | | | | | | | | |
Collapse
|
100
|
Gremlin-1 associates with fibrillin microfibrils in vivo and regulates mesothelioma cell survival through transcription factor slug. Oncogenesis 2013; 2:e66. [PMID: 23978876 PMCID: PMC3759128 DOI: 10.1038/oncsis.2013.29] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Accepted: 07/16/2013] [Indexed: 02/07/2023] Open
Abstract
Malignant mesothelioma is a form of cancer that is highly resistant to conventional cancer therapy for which no major therapeutic advances have been introduced. Here, we identify gremlin-1, a known bone morphogenetic protein inhibitor crucial for embryonic development, as a potential therapeutic target for mesothelioma. We found high expression levels of gremlin-1 in the mesothelioma tumor tissue, as well as in primary mesothelioma cells cultured from pleural effusion samples. Downregulation of gremlin-1 expression by siRNA-mediated silencing in a mesothelioma cell line inhibited cell proliferation. This was associated with downregulation of the transcription factor slug as well as mesenchymal proteins linked to cancer epithelial-to-mesenchymal transition. Further, resistance to paclitaxel-induced cell death was associated with high gremlin-1 and slug expression. Treatment of gremlin-1-silenced mesothelioma cells with paclitaxel or pemetrexed resulted in efficient loss of cell survival. Finally, our data suggest that concomitant upregulation of fibrillin-2 in mesothelioma provides a mechanism for extracellular localization of gremlin-1 to the tumor microenvironment. This was supported by the demonstration of interactions between gremlin-1, and fibrillin-1 and -2 peptides as well as by colocalization of gremlin-1 to fibrillin microfibrils in cells and tumor tissue samples. Our data suggest that gremlin-1 is also a potential target for overcoming drug resistance in mesothelioma.
Collapse
|