1
|
Zhang X, Duan X, Liu X. The role of kinases in peripheral nerve regeneration: mechanisms and implications. Front Neurol 2024; 15:1340845. [PMID: 38689881 PMCID: PMC11058862 DOI: 10.3389/fneur.2024.1340845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 04/02/2024] [Indexed: 05/02/2024] Open
Abstract
Peripheral nerve injury disease is a prevalent traumatic condition in current medical practice. Despite the present treatment approaches, encompassing surgical sutures, autologous nerve or allograft nerve transplantation, tissue engineering techniques, and others, an effective clinical treatment method still needs to be discovered. Exploring novel treatment methods to improve peripheral nerve regeneration requires more effort in investigating the cellular and molecular mechanisms involved. Many factors are associated with the regeneration of injured peripheral nerves, including the cross-sectional area of the injured nerve, the length of the nerve gap defect, and various cellular and molecular factors such as Schwann cells, inflammation factors, kinases, and growth factors. As crucial mediators of cellular communication, kinases exert regulatory control over numerous signaling cascades, thereby participating in various vital biological processes, including peripheral nerve regeneration after nerve injury. In this review, we examined diverse kinase classifications, distinct nerve injury types, and the intricate mechanisms involved in peripheral nerve regeneration. Then we stressed the significance of kinases in regulating autophagy, inflammatory response, apoptosis, cell cycle, oxidative processes, and other aspects in establishing conductive microenvironments for nerve tissue regeneration. Finally, we briefly discussed the functional roles of kinases in different types of cells involved in peripheral nerve regeneration.
Collapse
Affiliation(s)
- Xu Zhang
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
- Clinical Medical Research Center, Wuxi No. 2 People's Hospital, Jiangnan University Medical Center, Wuxi, China
| | - Xuchu Duan
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
| | - Xiaoyu Liu
- Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-innovation Center of Neuroregeneration, School of Life Science, Nantong Laboratory of Development and Diseases, Medical College, Clinical Medical Research Center, Affiliated Wuxi Clinical College of Nantong University, Nantong University, Nantong, China
| |
Collapse
|
2
|
Zhao Z, Li D, Wang N, Xu L, Weng Y, Zhou W, Pan Y. The identification and functional analysis of CircRNAs in endometrial receptivity of mice with polycystic ovary. ENVIRONMENTAL TOXICOLOGY 2024; 39:1456-1470. [PMID: 37987463 DOI: 10.1002/tox.24052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/07/2023] [Accepted: 11/10/2023] [Indexed: 11/22/2023]
Abstract
The disorders of endometrial receptivity and ovulatory dysfunction are both significant causes of infertility in patients with polycystic ovary syndrome (PCOS). In this study, we investigated the expression profile and functional implications of circular RNAs (circRNAs) in the endometrial receptivity of PCOS-affected mice. Twenty-four female C57BL/6 mice were divided into PCOS and normal control groups. The PCOS group received subcutaneous DHEA treatment, while the control group remained untreated. Gene chip technology was utilized to analyze circRNA expression in endometrial tissues on the fourth day of gestation with subsequent bioinformatics analyses into circRNA functions. Furthermore, endometrial epithelial cells were used to determine represented circRNA functions. Results showed that the PCOS group exhibited 205 differentially expressed circRNAs, with 147 upregulated and 58 downregulated ones. qRT-PCR confirmed differential expression of circRNAs, including circRNA_38548, circRNA_001686, circRNA_38550, and circRNA_27938. Predicted target genes and a circRNA-miRNA-mRNA regulatory network were constructed. Additionally, four circRNAs (circRNA_38548, circRNA_38550, and circRNA_001686) were identified to contribute to abnormal endometrial receptivity by regulating genes such as Lifr, FOXK1, FOXO1, HOXA10, through interactions with miRNAs. Further research is warranted to elucidate the underlying mechanisms involving these circRNAs.
Collapse
Affiliation(s)
- Ziwei Zhao
- Department of Gynaecology and Obstetrics, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Dawei Li
- Reproductive Center, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Nan Wang
- Reproductive Center, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Li Xu
- Reproductive Center, Yangzhou Maternal and Child Health Hospital, Yangzhou, China
| | - Yujing Weng
- Reproductive Center, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Weiqin Zhou
- Reproductive Center, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Yanping Pan
- Reproductive Center, The First Affiliated Hospital of Soochow University, Suzhou, China
| |
Collapse
|
3
|
Hussain MK, Ahmed S, Khan A, Siddiqui AJ, Khatoon S, Jahan S. Mucormycosis: A hidden mystery of fungal infection, possible diagnosis, treatment and development of new therapeutic agents. Eur J Med Chem 2023; 246:115010. [PMID: 36566630 PMCID: PMC9734071 DOI: 10.1016/j.ejmech.2022.115010] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2022] [Revised: 11/15/2022] [Accepted: 12/05/2022] [Indexed: 12/14/2022]
Abstract
Mucormycosis is a fungal infection which got worsens with time if not diagnosed and treated. The current COVID-19 pandemic has association with fungal infection specifically with mucormycosis. Already immunocompromised patients are easy target for COVID-19 and mucormycosis as well. COVID-19 infection imparts in weak immune system so chances of infection is comparatively high in COVID-19 patients. Furthermore, diabetes, corticosteroid medicines, and a weakened immune system are the most prevalent risk factors for this infection as we discussed in case studies here. The steroid therapy for COVID-19 patients sometimes have negative impact on the patient health and this state encounters many infections including mucormycosis. There are treatments available but less promising and less effective. So, researchers are focusing on the promising agents against mucormycosis. It is reported that early treatment with liposomal amphotericin B (AmB), manogepix, echinocandins isavuconazole, posacanazole and other promising therapeutic agents have overcome the burden of mucormycosis. Lipid formulations of AmB have become the standard treatment for mucormycosis due to their greater safety and efficacy. In this review article, we have discussed case studies with the infection of mucormycosis in COVID-19 patients. Furthermore, we focused on anti-mucormycosis agents with mechanism of action of various therapeutics, including coverage of new antifungal agents being investigated as part of the urgent global response to control and combat this lethal infection, especially those with established risk factors.
Collapse
Affiliation(s)
- Mohd Kamil Hussain
- Department of Chemistry, Govt. Raza PG College, Rampur, 244901, India,M.J.P. Rohil Khand University, Bareilly, India
| | - Shaista Ahmed
- Centre for Translational and Clinical Research, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi, 110062, India
| | - Andleeb Khan
- Department of Pharmacology and Toxicology, College of Pharmacy, Jazan University, Jazan 45142, Saudi Arabia
| | - Arif Jamal Siddiqui
- Department of Biology, College of Science, University of Hail, Hail, Saudi Arabia
| | | | - Sadaf Jahan
- Department of Medical Laboratory Sciences, College of Applied Medical Sciences, Majmaah University, Al-Majmaah, 11952, Saudi Arabia,Corresponding author
| |
Collapse
|
4
|
Metformin inhibits the development and metastasis of colorectal cancer. Med Oncol 2022; 39:136. [PMID: 35780231 DOI: 10.1007/s12032-022-01722-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/29/2022] [Indexed: 10/17/2022]
Abstract
Metformin is a commonly used drug for the treatment of diabetes. Accumulating evidence suggests that it exerts anti-cancer effects in many cancers, including colorectal cancer. However, the underlying molecular mechanisms of colorectal cancer metastasis remain unclear. Colorectal cancer cell lines were treated with metformin, and cell proliferation, invasion, and migration were analyzed in vitro. The relationship between metformin and the AMPK-mTOR axis was assessed by Western blot analysis and transfection with small interfering RNA. A colorectal cancer xenograft mouse model was used to observe the effects of metformin on liver metastasis. Immunohistochemical analysis was performed on liver metastatic tumors. In in vitro experiments, metformin significantly inhibited the proliferation, migration, and invasion only in HCT116 and SW837 cells, but not in HCT8 and Lovo cells. Only in HCT116 and SW837, a change in AMPK-mTOR expression was observed in a dose-dependent manner. In colorectal cancer xenograft mice, the liver metastatic rate (10% vs. 50%, p = 0.05) and the number of liver metastatic nodules (0.1/body vs. 1.2/body, p = 0.04) were significantly lower in the metformin group. Tumor proliferation and EMT were decreased and apoptosis was promoted only in metastatic liver tumors of mice treated with metformin. The molecular mechanism of the anti-cancer effects of metformin involves repression of mTOR pathways via AMPK activation. Moreover, the differences in metformin sensitivity depend on the response of the AMPK-mTOR pathway to metformin. Our study provides a theoretical basis for the anti-metastatic treatment of colorectal cancer using metformin.
Collapse
|
5
|
Willis SD, Hanley SE, Doyle SJ, Beluch K, Strich R, Cooper KF. Cyclin C-Cdk8 Kinase Phosphorylation of Rim15 Prevents the Aberrant Activation of Stress Response Genes. Front Cell Dev Biol 2022; 10:867257. [PMID: 35433688 PMCID: PMC9008841 DOI: 10.3389/fcell.2022.867257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 02/22/2022] [Indexed: 11/13/2022] Open
Abstract
Cells facing adverse environmental cues respond by inducing signal transduction pathways resulting in transcriptional reprograming. In the budding yeast Saccharomyces cerevisiae, nutrient deprivation stimulates stress response gene (SRG) transcription critical for entry into either quiescence or gametogenesis depending on the cell type. The induction of a subset of SRGs require nuclear translocation of the conserved serine-threonine kinase Rim15. However, Rim15 is also present in unstressed nuclei suggesting that additional activities are required to constrain its activity in the absence of stress. Here we show that Rim15 is directly phosphorylated by cyclin C-Cdk8, the conserved kinase module of the Mediator complex. Several results indicate that Cdk8-dependent phosphorylation prevents Rim15 activation in unstressed cells. First, Cdk8 does not control Rim15 subcellular localization and rim15∆ is epistatic to cdk8∆ with respect to SRG transcription and the execution of starvation programs required for viability. Next, Cdk8 phosphorylates a residue in the conserved PAS domain in vitro. This modification appears important as introducing a phosphomimetic at Cdk8 target residues reduces Rim15 activity. Moreover, the Rim15 phosphomimetic only compromises cell viability in stresses that induce cyclin C destruction as well as entrance into meiosis. Taken together, these findings suggest a model in which Cdk8 phosphorylation contributes to Rim15 repression whilst it cycles through the nucleus. Cyclin C destruction in response to stress inactivates Cdk8 which in turn stimulates Rim15 to maximize SRG transcription and cell survival.
Collapse
|
6
|
Mowrey K, Northrup H, Hashmi SS, Rodriguez-Buritica D. Expanding Our Knowledge of Menstrual Irregularities Reported by Females With Tuberous Sclerosis Complex. FRONTIERS IN REPRODUCTIVE HEALTH 2022; 4:798983. [DOI: 10.3389/frph.2022.798983] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2021] [Accepted: 01/25/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeThe purpose of our study is to expand the knowledge regarding intrinsic reproductive dysfunction in females with TSC and to explore the impact of mTOR inhibitors (mTORi) on menstrual irregularity in the Tuberous Sclerosis Complex (TSC) community.MethodsAn electronic survey composed of author-designed questions set out to evaluate reproductive history, presence of menstrual irregularities, mTORi use, as well as maternal reproductive history among females with TSC.ResultsOf the 68 responses from females with TSC regarding age of menarche, the average age was 12.3 years. 56.5% (n = 48) of respondents reported irregular menstrual cycles and noted a total of 102 menstrual irregularities. There was a cohort of 35 women with a reported history of mTORi use. Of these women, 68.6% (n = 24) reported irregular menstrual cycles after taking mTORi. In comparison, among the females with no history of mTORi use (n = 50) only 48% reported irregular menstrual cycles (n = 24).ConclusionsOur data expands the knowledge regarding intrinsic menstrual dysregulation present in women with TSC, demonstrates a rate of menstrual irregularities among females taking mTORi, and identifies a tendency toward early menarche that may be a previously unrecognized feature of TSC.
Collapse
|
7
|
Li Y, Wang H, Zhang Z, Tang C, Zhou X, Mohan C, Wu T. Identification of polo-like kinase 1 as a therapeutic target in murine lupus. Clin Transl Immunology 2022; 11:e1362. [PMID: 35024139 PMCID: PMC8733964 DOI: 10.1002/cti2.1362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 09/21/2021] [Accepted: 11/29/2021] [Indexed: 11/18/2022] Open
Abstract
Introduction The signalling cascades that contribute to lupus pathogenesis are incompletely understood. We address this by using an unbiased activity‐based kinome screen of murine lupus. Methods An unbiased activity‐based kinome screen (ABKS) of 196 kinases was applied to two genetically different murine lupus strains. Systemic and renal lupus were evaluated following in vivo PLK1blockade. The upstream regulators and downstream targets of PLK1 were also interrogated. Results Multiple signalling cascades were noted to be more active in murine lupus spleens, including PLK1. In vivo administration of a PLK1‐specific inhibitor ameliorated splenomegaly, anti‐dsDNA antibody production, proteinuria, BUN and renal pathology in MRL.lpr mice (P < 0.05). Serum IL‐6, IL‐17 and kidney injury molecule 1 (KIM‐1) were significantly decreased after PLK1 inhibition. PLK1 inhibition reduced germinal centre and marginal zone B cells in the spleen, but changes in T cells were not significant. In vitro, splenocytes were treated with anti‐mouse CD40 Ab or F(ab’)2 fragment anti‐mouse IgM. After 24‐h stimulation, IL‐6 secretion was significantly reduced upon PLK1 blockade, whereas IL‐10 production was significantly increased. The phosphorylation of mTOR was assessed in splenocyte subsets, which revealed a significant change in myeloid cells. PLK1 blockade reduced phosphorylation associated with mTOR signalling, while Aurora‐A emerged as a potential upstream regulator of PLK1. Conclusion The Aurora‐A → PLK1 → mTOR signalling axis may be central in lupus pathogenesis, and emerges as a potential therapeutic target.
Collapse
Affiliation(s)
- Yaxi Li
- Department of Biomedical Engineering University of Houston Houston TX USA
| | - Hongting Wang
- Department of Biomedical Engineering University of Houston Houston TX USA
| | - Zijing Zhang
- Department of Biomedical Engineering University of Houston Houston TX USA.,Institute of Animal Husbandry and Veterinary Science Henan Academy of Agricultural Sciences Zhengzhou Henan China
| | - Chenling Tang
- Department of Biomedical Engineering University of Houston Houston TX USA
| | - Xinjin Zhou
- Department of Pathology Baylor University Medical Center at Dallas Dallas TX USA
| | - Chandra Mohan
- Department of Biomedical Engineering University of Houston Houston TX USA
| | - Tianfu Wu
- Department of Biomedical Engineering University of Houston Houston TX USA
| |
Collapse
|
8
|
Zaman Q, Zhang D, Reddy OS, Wong WT, Lai WF. Roles and Mechanisms of Astragaloside IV in Combating Neuronal Aging. Aging Dis 2022; 13:1845-1861. [DOI: 10.14336/ad.2022.0126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 01/26/2022] [Indexed: 11/18/2022] Open
|
9
|
Synthetic mRNAs; Their Analogue Caps and Contribution to Disease. Diseases 2021; 9:diseases9030057. [PMID: 34449596 PMCID: PMC8395722 DOI: 10.3390/diseases9030057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2021] [Revised: 08/11/2021] [Accepted: 08/19/2021] [Indexed: 12/22/2022] Open
Abstract
The structure of synthetic mRNAs as used in vaccination against cancer and infectious diseases contain specifically designed caps followed by sequences of the 5′ untranslated repeats of β-globin gene. The strategy for successful design of synthetic mRNAs by chemically modifying their caps aims to increase resistance to the enzymatic deccapping complex, offer a higher affinity for binding to the eukaryotic translation initiation factor 4E (elF4E) protein and enforce increased translation of their encoded proteins. However, the cellular homeostasis is finely balanced and obeys to specific laws of thermodynamics conferring balance between complexity and growth rate in evolution. An overwhelming and forced translation even under alarming conditions of the cell during a concurrent viral infection, or when molecular pathways are trying to circumvent precursor events that lead to autoimmunity and cancer, may cause the recipient cells to ignore their differential sensitivities which are essential for keeping normal conditions. The elF4E which is a powerful RNA regulon and a potent oncogene governing cell cycle progression and proliferation at a post-transcriptional level, may then be a great contributor to disease development. The mechanistic target of rapamycin (mTOR) axis manly inhibits the elF4E to proceed with mRNA translation but disturbance in fine balances between mTOR and elF4E action may provide a premature step towards oncogenesis, ignite pre-causal mechanisms of immune deregulation and cause maturation (aging) defects.
Collapse
|
10
|
Zhang Y, Du X, Chen X, Tang H, Zhou Q, He J, Ding Y, Wang Y, Liu X, Geng Y. Rictor/mTORC2 is involved in endometrial receptivity by regulating epithelial remodeling. FASEB J 2021; 35:e21731. [PMID: 34131963 DOI: 10.1096/fj.202100529rr] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Revised: 05/27/2021] [Accepted: 05/28/2021] [Indexed: 11/11/2022]
Abstract
Successful embryo implantation requires well-functioning endometrial luminal epithelial cells to establish uterine receptivity. Inadequate uterine receptivity is responsible for approximately two thirds of implantation failures in humans. However, the regulatory mechanism governing this functional process remains largely unexplored. A previous study revealed that the expression of Rictor, the main member of mTORC2, in mouse epithelial cells is increased on the fourth day of gestation (D4). Here, we provide the first report of the involvement of Rictor in the regulation of endometrial receptivity. Rictor was conditionally ablated in the mouse endometrium using a progesterone receptor cre (PRcre ) mouse model. Loss of Rictor altered polarity remodeling and the Na+ channel protein of endometrial cells by mediating Rac-1/PAK1(pPAK1)/ERM(pERM) and Sgk1/pSgk1 signaling, respectively, ultimately resulting in impaired fertility. In the endometrium of women with infertility, the expression of Rictor was changed, along with the morphological transformation and Na+ channel protein of epithelial cells. Our findings demonstrate that Rictor is crucial for the establishment of uterine receptivity in both mice and humans. The present study may help improve the molecular regulatory network of endometrial receptivity and provide new diagnostic and treatment strategies for infertility.
Collapse
Affiliation(s)
- Yue Zhang
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Xinman Du
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Xuemei Chen
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Hongyu Tang
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Qin Zhou
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, P.R. China
| | - Junlin He
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Yubin Ding
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Yingxiong Wang
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
- College of Basic Medicine, Chongqing Medical University, Chongqing, P.R. China
| | - Xueqing Liu
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
| | - Yanqing Geng
- Joint International Research Laboratory of Reproduction & Development, School of Public Health and Management, Chongqing Medical University, Chongqing, P.R. China
- College of Basic Medicine, Chongqing Medical University, Chongqing, P.R. China
| |
Collapse
|
11
|
Integrated Analysis to Identify a Redox-Related Prognostic Signature for Clear Cell Renal Cell Carcinoma. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:6648093. [PMID: 33968297 PMCID: PMC8084660 DOI: 10.1155/2021/6648093] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 03/03/2021] [Accepted: 04/12/2021] [Indexed: 02/06/2023]
Abstract
The imbalance of the redox system has been shown to be closely related to the occurrence and progression of many cancers. However, the biological function and clinical significance of redox-related genes (RRGs) in clear cell renal cell carcinoma (ccRCC) are unclear. In our current study, we downloaded transcriptome data from The Cancer Genome Atlas (TCGA) database of ccRCC patients and identified the differential expression of RRGs in tumor and normal kidney tissues. Then, we identified a total of 344 differentially expressed RRGs, including 234 upregulated and 110 downregulated RRGs. Fourteen prognosis-related RRGs (ADAM8, CGN, EIF4EBP1, FOXM1, G6PC, HAMP, HTR2C, ITIH4, LTB4R, MMP3, PLG, PRKCG, SAA1, and VWF) were selected out, and a prognosis-related signature was constructed based on these RRGs. Survival analysis showed that overall survival was lower in the high-risk group than in the low-risk group. The area under the receiver operating characteristic curve of the risk score signature was 0.728 at three years and 0.759 at five years in the TCGA cohort and 0.804 at three years and 0.829 at five years in the E-MTAB-1980 cohort, showing good predictive performance. In addition, we explored the regulatory relationships of these RRGs with upstream miRNA, their biological functions and molecular mechanisms, and their relationship with immune cell infiltration. We also established a nomogram based on these prognostic RRGs and performed internal and external validation in the TCGA and E-MTAB-1980 cohorts, respectively, showing an accurate prediction of ccRCC prognosis. Moreover, a stratified analysis showed a significant correlation between the prognostic signature and ccRCC progression.
Collapse
|
12
|
Grasmann G, Mondal A, Leithner K. Flexibility and Adaptation of Cancer Cells in a Heterogenous Metabolic Microenvironment. Int J Mol Sci 2021; 22:1476. [PMID: 33540663 PMCID: PMC7867260 DOI: 10.3390/ijms22031476] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 01/28/2021] [Accepted: 01/29/2021] [Indexed: 02/06/2023] Open
Abstract
The metabolic microenvironment, comprising all soluble and insoluble nutrients and co-factors in the extracellular milieu, has a major impact on cancer cell proliferation and survival. A large body of evidence from recent studies suggests that tumor cells show a high degree of metabolic flexibility and adapt to variations in nutrient availability. Insufficient vascular networks and an imbalance of supply and demand shape the metabolic tumor microenvironment, which typically contains a lower concentration of glucose compared to normal tissues. The present review sheds light on the recent literature on adaptive responses in cancer cells to nutrient deprivation. It focuses on the utilization of alternative nutrients in anabolic metabolic pathways in cancer cells, including soluble metabolites and macromolecules and outlines the role of central metabolic enzymes conferring metabolic flexibility, like gluconeogenesis enzymes. Moreover, a conceptual framework for potential therapies targeting metabolically flexible cancer cells is presented.
Collapse
Affiliation(s)
- Gabriele Grasmann
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, A-8036 Graz, Austria; (G.G.); (A.M.)
| | - Ayusi Mondal
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, A-8036 Graz, Austria; (G.G.); (A.M.)
| | - Katharina Leithner
- Division of Pulmonology, Department of Internal Medicine, Medical University of Graz, A-8036 Graz, Austria; (G.G.); (A.M.)
- BioTechMed-Graz, A-8010 Graz, Austria
| |
Collapse
|
13
|
Cohen Kadosh K, Muhardi L, Parikh P, Basso M, Jan Mohamed HJ, Prawitasari T, Samuel F, Ma G, Geurts JMW. Nutritional Support of Neurodevelopment and Cognitive Function in Infants and Young Children-An Update and Novel Insights. Nutrients 2021; 13:nu13010199. [PMID: 33435231 PMCID: PMC7828103 DOI: 10.3390/nu13010199] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 01/06/2021] [Accepted: 01/07/2021] [Indexed: 12/12/2022] Open
Abstract
Proper nutrition is crucial for normal brain and neurocognitive development. Failure to optimize neurodevelopment early in life can have profound long-term implications for both mental health and quality of life. Although the first 1000 days of life represent the most critical period of neurodevelopment, the central and peripheral nervous systems continue to develop and change throughout life. All this time, development and functioning depend on many factors, including adequate nutrition. In this review, we outline the role of nutrients in cognitive, emotional, and neural development in infants and young children with special attention to the emerging roles of polar lipids and high quality (available) protein. Furthermore, we discuss the dynamic nature of the gut-brain axis and the importance of microbial diversity in relation to a variety of outcomes, including brain maturation/function and behavior are discussed. Finally, the promising therapeutic potential of psychobiotics to modify gut microbial ecology in order to improve mental well-being is presented. Here, we show that the individual contribution of nutrients, their interaction with other micro- and macronutrients and the way in which they are organized in the food matrix are of crucial importance for normal neurocognitive development.
Collapse
Affiliation(s)
- Kathrin Cohen Kadosh
- School of Psychology, University of Surrey, Guildford GU2 7XH, UK; (K.C.K.); (M.B.)
| | - Leilani Muhardi
- FrieslandCampina AMEA, Singapore 039190, Singapore; (L.M.); (P.P.)
| | - Panam Parikh
- FrieslandCampina AMEA, Singapore 039190, Singapore; (L.M.); (P.P.)
| | - Melissa Basso
- School of Psychology, University of Surrey, Guildford GU2 7XH, UK; (K.C.K.); (M.B.)
- Department of General Psychology, University of Padova, 35131 Padova, Italy
| | - Hamid Jan Jan Mohamed
- Nutrition and Dietetics Programme, School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian 16150, Malaysia;
| | - Titis Prawitasari
- Nutrition and Metabolic Diseases Working Group, Indonesian Pediatric Society, Jakarta 10310, Indonesia;
- Department of Pediatrics, Faculty of Medicine, Universitas Indonesia, Dr. Cipto Mangunkusomo National Referral Hospital Jakarta, Jakarta 10430, Indonesia
| | - Folake Samuel
- Department of Human Nutrition, University of Ibadan, Ibadan 200284, Nigeria;
| | - Guansheng Ma
- Department of Nutrition and Food Hygiene, School of Public Health, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China;
- Laboratory of Toxicological Research and Risk assessment for Food Safety, Peking University, 38 Xue Yuan Road, Haidian District, Beijing 100191, China
| | - Jan M. W. Geurts
- FrieslandCampina, 3818 LE Amersfoort, The Netherlands
- Correspondence: ; Tel.: +31-6-53310499
| |
Collapse
|
14
|
Liu J, Deng K, Pan M, Liu G, Wu J, Yang M, Huang D, Zhang W, Mai K. Dietary carbohydrates influence muscle texture of olive flounder Paralichthys olivaceus through impacting mitochondria function and metabolism of glycogen and protein. Sci Rep 2020; 10:21811. [PMID: 33311521 PMCID: PMC7732841 DOI: 10.1038/s41598-020-76255-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Accepted: 10/14/2020] [Indexed: 12/13/2022] Open
Abstract
The present study was conducted to estimate the effects of dietary carbohydrates on muscle quality and the underlying mechanisms. Six isonitrogenous and isolipidic diets were formulated to contain graded levels of carbohydrates (0%, 8%, 12%, 16%, 20% and 24%, respectively). These diets were named as C0, C8, C12, C16, C20 and C24, respectively. After a 10-week feeding trial, results showed that the muscle pH, liquid holding capacity (LHC) and hardness were significantly decreased by the increasing dietary carbohydrate levels. Dietary carbohydrates significantly decreased the muscle fibre diameter, and the highest value was found in the C0 group. Accumulated glycogen and degenerated mitochondrial cristae were observed in the C24 group. Significantly higher contents of protein carbonyls were observed in the C20 group and C24 group (P < 0.05). There was a significant decrease of mtDNA copy number in the C24 group compared with that in the C0 and C8 groups. The AMP/ATP ratio in muscle decreased first and then increased with the increasing dietary carbohydrate levels. The dietary incorporation of carbohydrate significantly reduced the expression of opa1, pygm and genes involved in myogenesis (myf5 and myog). Meanwhile, proteolysis-related genes (murf-1, mafbx, capn2 and ctsl), pro-inflammatory cytokines (il-6 and tnf-α) and mstn were significantly up-regulated. In the C24 group, significant increase of phosphorylation of AMPK (Thr172), up-regulation of PGC-1α and GLUT4 were observed, while the phosphorylation level of S6 (Ser235/236) was significantly decreased. It was concluded that excessive dietary carbohydrate level (24%) had negative impacts on mitochondria function and promoted glycogen accumulation, and thereafter influenced the muscle quality of olive flounder. The activation of AMPK as well as the upregulation of PGC-1α and GLUT4 was the key mechanism.
Collapse
Affiliation(s)
- Jiahuan Liu
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Kangyu Deng
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
- Shenzhen Alpha Group Co., Ltd., Shenzhen, China
| | - Mingzhu Pan
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Guangxia Liu
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Jing Wu
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Mengxi Yang
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Dong Huang
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
| | - Wenbing Zhang
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China.
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Wen Hai Road, Qingdao, 266237, China.
| | - Kangsen Mai
- The Key Laboratory of Aquaculture Nutrition and Feeds (Ministry of Agriculture and Rural Affairs), the Key Laboratory of Mariculture (Ministry of Education), Ocean University of China, Qingdao, 266003, China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Wen Hai Road, Qingdao, 266237, China
| |
Collapse
|
15
|
Mowrey K, Koenig MK, Szabo CA, Samuels J, Mulligan S, Pearson DA, Northrup H. Two different genetic etiologies for tuberous sclerosis complex (TSC) in a single family. Mol Genet Genomic Med 2020; 8:e1296. [PMID: 32383331 PMCID: PMC7336739 DOI: 10.1002/mgg3.1296] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Tuberous sclerosis complex (TSC) is an autosomal dominant genetic condition that involves abnormalities of the skin, hamartomas in the heart, brain, and kidneys, seizures, as well as TSC-associated neuropsychiatric disorders (TAND). About 90%-95% of individuals with TSC will have an identifiable pathogenic variant in either TSC1 or TSC2. We present here two family members with clinical diagnoses of TSC that were later determined to be due to two different genetic etiologies. METHODS A 2-year-old Caucasian female (Patient 1) was born to non-consanguineous healthy parents and was determined to have a clinical diagnosis of TSC at 2 months old. Her paternal great-uncle (Patient 2) was also known to have a clinical diagnosis of TSC. Sequencing and deletion/duplication analysis for TSC1 and TSC2 were performed on both individuals. RESULTS Mutation analysis revealed that both Patient 1 and Patient 2 had identifiable pathogenic variants in TSC2. Patient 1 had c.4800_4801delTG (p.Cys1600Trpfs*2), while Patient 2 had c.4470_4471delinsTT (p.Glu1490_Lys1491delinsAsp*). CONCLUSION To our knowledge, our clinical report is of significance as it is the third kindred to be identified with affected members with two distinct genetic etiologies for TSC. Our case report highlights the importance of incorporating genetic testing into the clinical evaluation for individuals with features suggestive of TSC.
Collapse
Affiliation(s)
- Kate Mowrey
- Department of PediatricsDivision of Medical GeneticsMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTXUSA
| | - Mary Kay Koenig
- Department of PediatricsDivision of Child and Adolescent NeurologyMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTXUSA
| | - Charles A. Szabo
- Department of Neurology and South Texas Comprehensive Epilepsy CenterUniversity of Texas Health Science Center at San AntonioTXUSA
| | - Joshua Samuels
- Department of PediatricsDivision of Nephrology and HypertensionMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTXUSA
| | - Shannon Mulligan
- Department of Obstetrics, Gynecology and Reproductive SciencesDivision of Genetic CounselingMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTXUSA
| | - Deborah A. Pearson
- Department of Psychiatry and Behavioral SciencesMcGovern Medical School at University of Texas Health Science Center at HoustonHoustonTXUSA
| | - Hope Northrup
- Department of PediatricsDivision of Medical GeneticsMcGovern Medical SchoolUniversity of Texas Health Science Center at HoustonHoustonTXUSA
| |
Collapse
|
16
|
Kordowitzki P, Hamdi M, Derevyanko A, Rizos D, Blasco M. The effect of rapamycin on bovine oocyte maturation success and metaphase telomere length maintenance. Aging (Albany NY) 2020; 12:7576-7584. [PMID: 32339158 PMCID: PMC7202508 DOI: 10.18632/aging.103126] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Accepted: 03/30/2020] [Indexed: 12/18/2022]
Abstract
Maternal aging-associated reduction of oocyte viability is a common feature in mammals, but more research is needed to counteract this process. In women, the first aging phenotype appears with a decline in reproductive function, and the follicle number gradually decreases from menarche to menopause. Cows can be used as a model of early human embryonic development and reproductive aging because both species share a very high degree of similarity during follicle selection, cleavage, and blastocyst formation. Recently, it has been proposed that the main driver of aging is the mammalian target of rapamycin (mTOR) signaling rather than reactive oxygen species. Based on these observations, the study aimed to investigate for the first time the possible role of rapamycin on oocyte maturation, embryonic development, and telomere length in the bovine species, as a target for future strategies for female infertility caused by advanced maternal age. The 1nm rapamycin in vitro treatment showed the best results for maturation rates (95.21±4.18%) of oocytes and was considered for further experiments. In conclusion, rapamycin influenced maturation rates of oocytes in a concentration-dependent manner. Our results also suggest a possible link between mTOR, telomere maintenance, and bovine blastocyst formation.
Collapse
Affiliation(s)
- Pawel Kordowitzki
- Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Olsztyn, Poland.,Institute of Veterinary Medicine, Nicolaus Copernicus University, Torun, Poland
| | - Meriem Hamdi
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Department of Animal Reproduction, Madrid, Spain
| | - Aksinya Derevyanko
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| | - Dimitrios Rizos
- Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Department of Animal Reproduction, Madrid, Spain
| | - Maria Blasco
- Telomeres and Telomerase Group, Spanish National Cancer Research Centre (CNIO), Madrid, Spain
| |
Collapse
|
17
|
Adegoke OAJ, Beatty BE, Kimball SR, Wing SS. Interactions of the super complexes: When mTORC1 meets the proteasome. Int J Biochem Cell Biol 2019; 117:105638. [PMID: 31678320 DOI: 10.1016/j.biocel.2019.105638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 10/18/2019] [Accepted: 10/20/2019] [Indexed: 12/30/2022]
Abstract
Homeostatic regulation of energy and metabolic status requires that anabolic and catabolic signaling pathways be precisely regulated and coordinated. Mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is a mega protein complex that promotes energy-consuming anabolic processes of protein and nucleic acid synthesis as well lipogenesis in times of energy and nutrient abundance. However, it is best characterized as the regulator of steps leading to protein synthesis. The ubiquitin-proteasome proteolytic system (UPS) is a major intracellular proteolytic system whose activity is increased during periods of nutrient scarcity and in muscle wasting conditions such as cachexia. Recent studies have examined the impact of mTORC1 on levels and functions of the 26S proteasome, the mega protease complex of the UPS. Here we first briefly review current understanding of the regulation of mTORC1, the UPS, and the 26S proteasome complex. We then review evidence of the effect of each complex on the abundance and functions of the other. Given the fact that drugs that inhibit either complex are either in clinical trials or are approved for treatment of cancer, a muscle wasting condition, we identify studying the effect of combinatory mTORC1-proteasome inhibition on skeletal muscle mass and health as a critical area requiring investigation.
Collapse
Affiliation(s)
- Olasunkanmi A J Adegoke
- School of Kinesiology and Health Science, and Muscle Health Research Centre, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada.
| | - Brendan E Beatty
- School of Kinesiology and Health Science, and Muscle Health Research Centre, York University, 4700 Keele Street, Toronto, Ontario, M3J 1P3 Canada
| | - Scot R Kimball
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey, PA 17033, USA
| | - Simon S Wing
- Department of Medicine, McGill University and the Research Institute of the McGill University Health Centre, the Montreal Diabetes Research Centre, Montréal, Quebec, H4A 3J1. Canada
| |
Collapse
|
18
|
Li XG, Du JH, Lu Y, Lin XJ. Neuroprotective effects of rapamycin on spinal cord injury in rats by increasing autophagy and Akt signaling. Neural Regen Res 2019; 14:721-727. [PMID: 30632514 PMCID: PMC6352584 DOI: 10.4103/1673-5374.247476] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Rapamycin treatment has been shown to increase autophagy activity and activate Akt phosphorylation, suppressing apoptosis in several models of ischemia reperfusion injury. However, little has been studied on the neuroprotective effects on spinal cord injury by activating Akt phosphorylation. We hypothesized that both effects of rapamycin, the increased autophagy activity and Akt signaling, would contribute to its neuroprotective properties. In this study, a compressive spinal cord injury model of rat was created by an aneurysm clip with a 30 g closing force. Rat models were intraperitoneally injected with rapamycin 1 mg/kg, followed by autophagy inhibitor 3-methyladenine 2.5 mg/kg and Akt inhibitor IV 1 µg/kg. Western blot assay, immunofluorescence staining and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay were used to observe the expression of neuronal autophagy molecule Beclin 1, apoptosis-related molecules Bcl-2, Bax, cytochrome c, caspase-3 and Akt signaling. Our results demonstrated that rapamycin inhibited the expression of mTOR in injured spinal cord tissue and up-regulated the expression of Beclin 1 and phosphorylated-Akt. Rapamycin prevented the decrease of bcl-2 expression in injured spinal cord tissue, reduced Bax, cytochrome c and caspase-3 expression levels and reduced the number of apoptotic neurons in injured spinal cord tissue 24 hours after spinal cord injury. 3-Methyladenine and Akt inhibitor IV intervention suppressed the expression of Beclin-1 and phosphorylated-Akt in injured spinal cord tissue and reduced the protective effect of rapamycin on apoptotic neurons. The above results indicate that the neuroprotective effect of rapamycin on spinal cord injury rats can be achieved by activating autophagy and the Akt signaling pathway.
Collapse
Affiliation(s)
- Xi-Gong Li
- Department of Orthopedic Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Jun-Hua Du
- Department of Orthopedic Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yang Lu
- Department of Orthopedic Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xiang-Jin Lin
- Department of Orthopedic Surgery, The First Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| |
Collapse
|
19
|
Huang H, Wang J, Zhang Y, Zhu G, Li YP, Ping J, Chen W. Bone resorption deficiency affects tooth root development in RANKL mutant mice due to attenuated IGF-1 signaling in radicular odontoblasts. Bone 2018; 114:161-171. [PMID: 29292230 DOI: 10.1016/j.bone.2017.12.026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 11/27/2017] [Accepted: 12/28/2017] [Indexed: 01/05/2023]
Abstract
The tooth root is essential for normal tooth physiological function. Studies on mice with mutations or targeted gene deletions revealed that osteoclasts (OCs) play an important role in tooth root development. However, knowledge on the cellular and molecular mechanism underlying how OCs mediate root formation is limited. During bone formation, growth factors (e.g. Insulin-like growth factor-1, IGF-1) liberated from bone matrix by osteoclastic bone resorption stimulate osteoblast differentiation. Thus, we hypothesize that OC-osteoblast coupling may also apply to OC-odontoblast coupling; therefore OCs may have a direct impact on odontoblast differentiation through the release of growth factor(s) from bone matrix, and consequently regulate tooth root formation. To test this hypothesis, we used a receptor activator of NF-κB ligand (RANKL) knockout mouse model in which OC differentiation and function was entirely blocked. We found that molar root formation and tooth eruption were defective in RANKL-/- mice. Disrupted elongation and disorganization of Hertwig's epithelial root sheath (HERS) was observed in RANKL-/- mice. Reduced expression of nuclear factor I C (NFIC), osterix, and dentin sialoprotein, markers essential for radicular (root) odontogenic cell differentiation indicated that odontoblast differentiation was disrupted in RANKL deficient mice likely contributing to the defect in root formation. Moreover, down-regulation of IGF/AKT/mTOR activity in odontoblast indicated that IGF signaling transduction in odontoblasts of the mutant mice was impaired. Treating odontoblast cells in vitro with conditioned medium from RANKL-/- OCs cultured on bone slices resulted in inhibition of odontoblast differentiation. Moreover, depletion of IGF-1 in bone resorption-conditioned medium (BRCM) from wild-type (WT) OC significantly compromised the ability of WT osteoclastic BRCM to induce odontoblast differentiation while addition of IGF-1 into RANKL-/- osteoclastic BRCM rescued impaired odontoblast differentiation, confirming that root and eruption defect in RANKL deficiency mice may result from failure of releasing of IGF-1 from bone matrix through OC bone resorption. These results suggest that OCs are important for odontoblast differentiation and tooth root formation, possibly through IGF/AKT/mTOR signaling mediated by cell-bone matrix interaction. These findings provide significant insights into regulatory mechanism of tooth root development, and also lay the foundation for root regeneration studies.
Collapse
Affiliation(s)
- Hong Huang
- The Affiliated Hospital of Stomatology, Chongqing Medical University, 5 Shangqingsi Rd, Yuzhong Qu, Chongqing Shi 400065, China; Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Jue Wang
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Yan Zhang
- The Affiliated Hospital of Stomatology, Chongqing Medical University, 5 Shangqingsi Rd, Yuzhong Qu, Chongqing Shi 400065, China; Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Guochun Zhu
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Yi-Ping Li
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA
| | - Ji Ping
- The Affiliated Hospital of Stomatology, Chongqing Medical University, 5 Shangqingsi Rd, Yuzhong Qu, Chongqing Shi 400065, China.
| | - Wei Chen
- Department of Pathology, School of Medicine, University of Alabama at Birmingham, 1825 University Blvd., Birmingham, AL 35294, USA.
| |
Collapse
|
20
|
A pharmacodynamic study of sirolimus and metformin in patients with advanced solid tumors. Cancer Chemother Pharmacol 2018; 82:309-317. [PMID: 29948021 DOI: 10.1007/s00280-018-3619-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2018] [Accepted: 06/04/2018] [Indexed: 01/14/2023]
Abstract
BACKGROUND Sirolimus is a mammalian target of rapamycin (mTOR) inhibitor. Metformin may potentiate mTOR inhibition by sirolimus while mitigating its adverse effects. We conducted a pilot study to test this hypothesis. METHODS Patients with advanced solid tumor were treated with sirolimus for 7 days followed by randomization to either sirolimus with metformin (Arm A) or sirolimus (Arm B) until day 21. From day 22 onwards, all patients received sirolimus and metformin. The primary aim was to compare the change in phospho-p70S6K (pp70S6K) in peripheral blood mononuclear cells (PBMC) from day 8 to day 22 using a two-sample t test. Secondary aims were objective response rate, toxicity, and other serum pharmacodynamic biomarkers (e.g., fasting glucose, triglycerides, insulin, C-peptide, IGF-1, IGF-1R, IGF-BP, and leptin). RESULTS 24 patients were enrolled, with 18 evaluable for the primary endpoint. There was no significant difference in mean change in pp70S6K in arm A vs. arm B (- 0.12 vs. - 0.16; P = 0.64). Similarly, there were no significant differences in other serum pharmacodynamic biomarkers. There were no partial responses. There were no dose-limiting or unexpected toxicities. CONCLUSIONS Adding metformin to sirolimus, although well tolerated, was not associated with significant changes in pp70S6K in PBMC or other serum pharmacodynamic biomarkers. IMPACT Combining metformin with sirolimus did not improve mTOR inhibition.
Collapse
|
21
|
Ramakrishnan V, D'Souza A. Signaling Pathways and Emerging Therapies in Multiple Myeloma. Curr Hematol Malig Rep 2017; 11:156-64. [PMID: 26922744 DOI: 10.1007/s11899-016-0315-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Multiple myeloma (MM) is a devastating malignancy of antibody-producing plasma cells. In the absence of a single unifying genetic event contributing to disease manifestation, efforts have focused on understanding signaling events deregulated in myeloma plasma cells. MM cells are dependent on both cellular and non-cellular components of the tumor microenvironment such as bone marrow stromal cells, endothelial cells, and cytokines such as interleukin 6 (IL6), vascular endothelial growth factor (VEGF), and insulin-like growth factor (IGF) for their growth and survival. The cumulative effect of such interactions is the aberrant activation of numerous signal transduction pathways within the MM plasma cells leading to uncontrolled growth and prevention of apoptosis. Here, we will review our current understanding of some of the key signal transduction pathways dysregulated in MM and emerging therapies targeting these pathways in MM.
Collapse
Affiliation(s)
- Vijay Ramakrishnan
- Division of Hematology, Mayo Clinic, 200, First Street SW, Rochester, MN, 55905, USA.
| | - Anita D'Souza
- Medical College of Wisconsin Milwaukee, Milwaukee, WI, 53226, USA.
| |
Collapse
|
22
|
Duplanty AA, Budnar RG, Luk HY, Levitt DE, Hill DW, McFarlin BK, Huggett DB, Vingren JL. Effect of Acute Alcohol Ingestion on Resistance Exercise-Induced mTORC1 Signaling in Human Muscle. J Strength Cond Res 2017; 31:54-61. [PMID: 27135475 DOI: 10.1519/jsc.0000000000001468] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Duplanty, AA, Budnar, RG, Luk, HY, Levitt, DE, Hill, DW, McFarlin, BK, Huggett, DB, and Vingren, JL. Effect of acute alcohol ingestion on resistance exercise-induced mTORC1 signaling in human muscle. J Strength Cond Res 31(1): 54-61, 2017-The purpose of this project was to further elucidate the effects postexercise alcohol ingestion. This project had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. Ten resistance-trained males and 9 resistance-trained females completed 2 identical acute heavy RE trials (6 sets of Smith machine squats) followed by ingestion of either alcohol or placebo. All participants completed both conditions. Before exercise (PRE) and 3 (+3 hours) and 5 (+5 hours) hours postexercise, muscle tissue samples were obtained from the vastus lateralis by biopsies. Muscle samples were analyzed for phosphorylated mTOR, S6K1, and 4E-BP1. For men, there was a significant interaction effect for mTOR and S6K1 phosphorylation. At +3 hours, mTOR and S6K1 phosphorylation was higher for placebo than for alcohol. For women, there was a significant main effect for time. mTOR phosphorylation was higher at +3 hours than at PRE and at +5 hours. There were no significant effects found for 4E-BP1 phosphorylation in men or women. The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion seemed to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men. This study provides evidence that alcohol should not be ingested after RE as this ingestion could potentially hamper the desired muscular adaptations to RE by reducing anabolic signaling, at least in men.
Collapse
Affiliation(s)
- Anthony A Duplanty
- 1Applied Physiology Laboratory, Department of Kinesiology, Health Promotion, and Recreation, University of North Texas, Denton, Texas; 2Department of Biological Sciences, University of North Texas, Denton, Texas; and 3Department of Physiology, Louisiana State University Health Sciences Center, New Orleans, Louisiana
| | | | | | | | | | | | | | | |
Collapse
|
23
|
da Silva MB, da Cunha FF, Terra FF, Camara NOS. Old game, new players: Linking classical theories to new trends in transplant immunology. World J Transplant 2017; 7:1-25. [PMID: 28280691 PMCID: PMC5324024 DOI: 10.5500/wjt.v7.i1.1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2016] [Revised: 11/16/2016] [Accepted: 12/07/2016] [Indexed: 02/05/2023] Open
Abstract
The evolutionary emergence of an efficient immune system has a fundamental role in our survival against pathogenic attacks. Nevertheless, this same protective mechanism may also establish a negative consequence in the setting of disorders such as autoimmunity and transplant rejection. In light of the latter, although research has long uncovered main concepts of allogeneic recognition, immune rejection is still the main obstacle to long-term graft survival. Therefore, in order to define effective therapies that prolong graft viability, it is essential that we understand the underlying mediators and mechanisms that participate in transplant rejection. This multifaceted process is characterized by diverse cellular and humoral participants with innate and adaptive functions that can determine the type of rejection or promote graft acceptance. Although a number of mediators of graft recognition have been described in traditional immunology, recent studies indicate that defining rigid roles for certain immune cells and factors may be more complicated than originally conceived. Current research has also targeted specific cells and drugs that regulate immune activation and induce tolerance. This review will give a broad view of the most recent understanding of the allogeneic inflammatory/tolerogenic response and current insights into cellular and drug therapies that modulate immune activation that may prove to be useful in the induction of tolerance in the clinical setting.
Collapse
|
24
|
Xing G, Luo Z, Zhong C, Pan X, Xu X. Influence of miR-155 on Cell Apoptosis in Rats with Ischemic Stroke: Role of the Ras Homolog Enriched in Brain (Rheb)/mTOR Pathway. Med Sci Monit 2016; 22:5141-5153. [PMID: 28025572 PMCID: PMC5215517 DOI: 10.12659/msm.898980] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Background We designed and carried out this study to examine the role of miR-155 and the Rheb/mTOR pathway in ischemic stroke. We also investigated how these two elements interact with each other and contribute to injuries resulting from ischemic stroke. Material/Methods We used both a middle cerebral artery occlusion rat model in vivo and an oxygen-glucose deprivation cell model in vitro to simulate the onset of ischemic stroke. miR-155 mimics, miR-155 inhibitors, and Rheb siRNA were transfected to alter the expression of miR-155 and Rheb. Infarct sizes were measured using magnetic resonance imaging (MRI) and triphenyltetrazolium chloride (TTC) staining; cell apoptosis rates were calculated using Annexin V-FITC/PI staining and flow cytometry. Levels of miR-155, Rheb, mTOR, and S6K were examined by RT-PCR, immunofluorescence, and western blot. We performed a luciferase activity assay so that the association between miR-155 and Rheb could be fully assessed. Results We demonstrated that miR-155 bound the 3′-UTR of Rheb and suppressed Rheb expression. As suggested by animal models, significant cerebral infarct volumes and cell apoptosis were induced by increased expression of miR-155 and decreased expression of Rheb, mTOR, and p-S6K (P<0.05). miR-155 inhibitors exhibited protective effects on ischemic stroke, including down-regulation of infarction size in cerebral tissues in vivo and reduced apoptosis of BV2 cells in vitro with increased expression of Rheb, mTOR and p-S6K (P<0.05). These protective effects could be substantially antagonized by the transfection of Rheb siRNA (P<0.05). Conclusions Inhibition of miR-155 may play protective roles in ischemic stroke by phosphorylating S6K through the Rheb/mTOR pathway.
Collapse
Affiliation(s)
- Guoping Xing
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland).,Department of Neurology, Weifang People's Hospital, Weifang, Shandong, China (mainland)
| | - Zengxiang Luo
- Department of Dermatology, Affiliated Hospital of Weifang Medical University, Weifang, Shandong, China (mainland)
| | - Chi Zhong
- Department of Neurology, Weifang People's Hospital, Weifang, Shandong, China (mainland)
| | - Xudong Pan
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland)
| | - Xiaowei Xu
- Department of Neurology, The Affiliated Hospital of Qingdao University, Qingdao, Shandong, China (mainland)
| |
Collapse
|
25
|
Zhang C, Liu J, Jin N, Zhang G, Xi Y, Liu H. SiRNA Targeting mTOR Effectively Prevents the Proliferation and Migration of Human Lens Epithelial Cells. PLoS One 2016; 11:e0167349. [PMID: 27911920 PMCID: PMC5135089 DOI: 10.1371/journal.pone.0167349] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 11/12/2016] [Indexed: 12/14/2022] Open
Abstract
Posterior capsule opacification (PCO) is the most common complication that causes visual decrease after extracapsular cataract surgery. The primary cause of PCO formation is the proliferation of the residual lens epithelial cells (LECs). The mammalian target of rapamycin (mTOR) plays an important role in the growth and migration of LECs. In the current study, we used small interfering RNA (siRNA) to specifically attenuate mTOR in human lens epithelial B3 cells (HLE B3). We aimed to examine the effect of mTOR-siRNA on the proliferation, migration and epithelial-to-mesenchymal transition (EMT) of HLE B3 cells and explore the underlying mechanisms. The mTOR-siRNA was transfected into HLE B3 cells using lipofectamine 2000. The mRNA and protein levels of mTOR were examined to confirm the efficiency of mTOR-siRNA. The levels of mRNA and protein as well as the activity of mTOR down-stream effectors p70 ribosomal protein S6 kinase (p70S6K) and protein kinase B (PKB, AKT) were examined using real-time PCR or Western blot, respectively. The cell proliferation was determined using cell counting kit (CCK) 8 and cell growth curve assay. The cell migration was examined using Transwell system and Scratch assay. MTOR-siRNA effectively eliminated mTOR mRNA and protein. The proliferation and migration were significantly suppressed by mTOR-siRNA transfection. mTOR-siRNA reduced the mRNA of p70S6K and AKT in a time-dependent manner. Furthermore, the phosphorylation of p70S6K and AKT was decreased by mTOR-siRNA. MTOR-siRNA also eliminated the formation of mTORC1 and mTORC2 protein complex and blocked the transforming growth factor (TGF)-β-induced EMT. Our results suggested that mTOR-siRNA could effectively inhibit the proliferation, migration and EMT of HLE B3 cells through the inhibition of p70S6K and AKT. These results indicated that mTOR-siRNA might be an effective agent inhibiting HLE cells growth and EMT following cataract surgery and provide an alternative therapy for preventing PCO.
Collapse
Affiliation(s)
- Chunmei Zhang
- Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Jingjing Liu
- Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Na Jin
- Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Guiming Zhang
- Department of Ophthalmology, No.2 Hospital of Xiamen, Fujian, P.R. China
| | - Yahui Xi
- Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| | - Hongling Liu
- Department of Ophthalmology, the First Affiliated Hospital of Harbin Medical University, Harbin, P.R. China
| |
Collapse
|
26
|
Blandino-Rosano M, Scheys JO, Jimenez-Palomares M, Barbaresso R, Bender AS, Yanagiya A, Liu M, Rui L, Sonenberg N, Bernal-Mizrachi E. 4E-BP2/SH2B1/IRS2 Are Part of a Novel Feedback Loop That Controls β-Cell Mass. Diabetes 2016; 65:2235-48. [PMID: 27217487 PMCID: PMC4955981 DOI: 10.2337/db15-1443] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Accepted: 05/09/2016] [Indexed: 01/08/2023]
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) regulates several biological processes, although the key downstream mechanisms responsible for these effects are poorly defined. Using mice with deletion of eukaryotic translation initiation factor 4E-binding protein 2 (4E-BP2), we determine that this downstream target is a major regulator of glucose homeostasis and β-cell mass, proliferation, and survival by increasing insulin receptor substrate 2 (IRS2) levels and identify a novel feedback mechanism by which mTORC1 signaling increases IRS2 levels. In this feedback loop, we show that 4E-BP2 deletion induces translation of the adaptor protein SH2B1 and promotes the formation of a complex with IRS2 and Janus kinase 2, preventing IRS2 ubiquitination. The changes in IRS2 levels result in increases in cell cycle progression, cell survival, and β-cell mass by increasing Akt signaling and reducing p27 levels. Importantly, 4E-BP2 deletion confers resistance to cytokine treatment in vitro. Our data identify SH2B1 as a major regulator of IRS2 stability, demonstrate a novel feedback mechanism linking mTORC1 signaling with IRS2, and identify 4E-BP2 as a major regulator of proliferation and survival of β-cells.
Collapse
Affiliation(s)
- Manuel Blandino-Rosano
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI
| | - Joshua O Scheys
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI
| | - Margarita Jimenez-Palomares
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI
| | - Rebecca Barbaresso
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI
| | - Aaron S Bender
- Diabetes, Obesity and Metabolism Institute, The Icahn School of Medicine at Mount Sinai, New York, NY
| | - Akiko Yanagiya
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Ming Liu
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI
| | - Liangyou Rui
- Department of Molecular & Integrative Physiology, University of Michigan Medical School, Ann Arbor, MI
| | - Nahum Sonenberg
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
| | - Ernesto Bernal-Mizrachi
- Division of Metabolism, Endocrinology & Diabetes, Department of Internal Medicine, University of Michigan Health System, Ann Arbor, MI VA Ann Arbor Healthcare System, Ann Arbor, MI
| |
Collapse
|
27
|
Garza-Lombó C, Gonsebatt ME. Mammalian Target of Rapamycin: Its Role in Early Neural Development and in Adult and Aged Brain Function. Front Cell Neurosci 2016; 10:157. [PMID: 27378854 PMCID: PMC4910040 DOI: 10.3389/fncel.2016.00157] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 05/30/2016] [Indexed: 01/14/2023] Open
Abstract
The kinase mammalian target of rapamycin (mTOR) integrates signals triggered by energy, stress, oxygen levels, and growth factors. It regulates ribosome biogenesis, mRNA translation, nutrient metabolism, and autophagy. mTOR participates in various functions of the brain, such as synaptic plasticity, adult neurogenesis, memory, and learning. mTOR is present during early neural development and participates in axon and dendrite development, neuron differentiation, and gliogenesis, among other processes. Furthermore, mTOR has been shown to modulate lifespan in multiple organisms. This protein is an important energy sensor that is present throughout our lifetime its role must be precisely described in order to develop therapeutic strategies and prevent diseases of the central nervous system. The aim of this review is to present our current understanding of the functions of mTOR in neural development, the adult brain and aging.
Collapse
Affiliation(s)
- Carla Garza-Lombó
- Departamento de Medicina Genómica, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México México
| | - María E Gonsebatt
- Departamento de Medicina Genómica, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México México
| |
Collapse
|
28
|
Gao HN, Hu H, Zheng N, Wang JQ. Leucine and histidine independently regulate milk protein synthesis in bovine mammary epithelial cells via mTOR signaling pathway. J Zhejiang Univ Sci B 2016; 16:560-72. [PMID: 26055918 DOI: 10.1631/jzus.b1400337] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study is to investigate the effects of leucine (Leu) and histidine (His) on the expression of both the mammalian target of rapamycin (mTOR) signaling pathway-related proteins and caseins in immortalized bovine mammary epithelial cells (CMEC-H), using a single supplement through Western blotting. The Earle's balanced salt solution (EBSS) was set as the control group and other treatment groups, based on the EBSS, were added with different concentrations of Leu or His, respectively. The results showed that, compared with the control group, the expression of caseins and the phosphorylation of mTOR (Ser(2481)), Raptor (Ser(792)), eIF4E (Ser(209)), and eEF2 (Thr(56)) increased with the Leu concentrations ranging from 0.45 to 10.80 mmol/L (P<0.01). The P-4EBP1 (Thr(37)) at 10.80 mmol/L Leu, and P-RPS6 (Ser(235/236)) at 5.40 to 10.80 mmol/L Leu all decreased. Similarly, the His supplementation from 0.15 to 9.60 mmol/L increased the expression of αs2-casein, β-casein, κ-casein, P-mTOR (Ser(2481)), P-Raptor (Ser(792)), P-S6K1 (Thr(389)), P-4EBP1 (Thr(37)), P-eIF4E (Ser(209)), and P-eEF2 (Thr(56)) (P<0.01) in CMEC-H, whereas the αs1-casein expression was only reduced at 9.60 mmol/L His, G protein β subunit-like protein (GβL) at 0.15 and 9.60 mmol/L His, and P-RPS6 at 4.80 to 9.60 mmol/L His. Our linear regression model assay suggested that the αs1-casein expression was positively correlated with P-mTOR (P<0.01), P-S6K1 (P<0.01), and P-eEF2 (P<0.01) for the addition of Leu, while the expressions of β-casein (P<0.01) and κ-casein (P<0.01) were positively correlated with P-eEF2 for the addition of His. In conclusion, the milk protein synthesis was up-regulated through activation of the mTOR pathway with the addition of Leu and His in CMEC-H.
Collapse
Affiliation(s)
- Hai-na Gao
- Ministry of Agriculture-Milk Risk Assessment Laboratory, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Animal Science and Technology, Gansu Agricultural University, Lanzhou 730070, China; Ministry of Agriculture-Milk and Dairy Product Inspection Center, Beijing 100193, China; State Key Laboratory of Animal Nutrition, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | | | | | | |
Collapse
|
29
|
Chen S, Sang N. Hypoxia-Inducible Factor-1: A Critical Player in the Survival Strategy of Stressed Cells. J Cell Biochem 2016; 117:267-78. [PMID: 26206147 PMCID: PMC4715696 DOI: 10.1002/jcb.25283] [Citation(s) in RCA: 78] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Accepted: 07/20/2015] [Indexed: 12/31/2022]
Abstract
HIF-1 activation has been well known as an adaptive strategy to hypoxia. Recently it became clear that hypoxia was often accompanied by insufficient supply of glucose or amino acids as a common result of poor circulation that frequently occurs in solid tumors and ischemic lesions, creating a mixed nutrient insufficiency. In response to nutrient insufficiency, stressed cells elicit survival strategies including activation of AMPK and HIF-1 to cope with the stress. Particularly, in solid tumors, HIF-1 promotes cell survival and migration, stimulates angiogenesis, and induces resistance to radiation and chemotherapy. Interestingly, radiation and some chemotherapeutics are reported to trigger the activation of AMPK. Here we discuss the recent advances that may potentially link the stress responsive mechanisms including AMPK activation, ATF4 activation and the enhancement of Hsp70/Hsp90 function to HIF-1 activation. Potential implication and application of the stress-facilitated HIF-1 activation in solid tumors and ischemic disorders will be discussed. A better understanding of HIF-1 activation in cells exposed to stresses is expected to facilitate the design of therapeutic approaches that specifically modulate cell survival strategy.
Collapse
Affiliation(s)
- Shuyang Chen
- Department of Biology and Graduate Program of Biological Sciences, College of Arts and Sciences, Drexel University, Philadelphia, Pennsylvania
| | - Nianli Sang
- Department of Biology and Graduate Program of Biological Sciences, College of Arts and Sciences, Drexel University, Philadelphia, Pennsylvania
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, Pennsylvania
- Sydney Kimmel Cancer Center, Philadelphia, Pennsylvania
| |
Collapse
|
30
|
Abstract
The translation initiation factor eIF4E mediates a rate-limiting process that drives selective translation of many oncongenic proteins such as cyclin D1, survivin and VEGF, thereby contributing to tumour growth, metastasis and therapy resistance. As an essential regulatory hub in cancer signalling network, many oncogenic signalling pathways appear to converge on eIF4E. Therefore, targeting eIF4E-mediated cap-dependent translation is considered a promising anticancer strategy. This paper reviews the strategies that can be used to target eIF4E, highlighting agents that target eIF4E activity at each distinct level.
Collapse
|
31
|
Widespread JNK-dependent alternative splicing induces a positive feedback loop through CELF2-mediated regulation of MKK7 during T-cell activation. Genes Dev 2016; 29:2054-66. [PMID: 26443849 PMCID: PMC4604346 DOI: 10.1101/gad.267245.115] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
In this study, Martinez et al. find a positive feedback loop in the JNK signaling pathway through the alternative splicing of MKK7, identify the RNA-binding protein CELF2 as a major regulator of MKK7 splicing, and show that ∼25% of T-cell receptor-mediated alternative splicing events are dependent on JNK signaling. This study provides insight into a novel paradigm for the reciprocal interplay of signaling and splicing. Alternative splicing is prevalent among genes encoding signaling molecules; however, the functional consequence of differential isoform expression remains largely unknown. Here we demonstrate that, in response to T-cell activation, the Jun kinase (JNK) kinase MAP kinase kinase 7 (MKK7) is alternatively spliced to favor an isoform that lacks exon 2. This isoform restores a JNK-docking site within MKK7 that is disrupted in the larger isoform. Consistently, we show that skipping of MKK7 exon 2 enhances JNK pathway activity, as indicated by c-Jun phosphorylation and up-regulation of TNF-α. Moreover, this splicing event is itself dependent on JNK signaling. Thus, MKK7 alternative splicing represents a positive feedback loop through which JNK promotes its own signaling. We further show that repression of MKK7 exon 2 is dependent on the presence of flanking sequences and the JNK-induced expression of the RNA-binding protein CELF2, which binds to these regulatory elements. Finally, we found that ∼25% of T-cell receptor-mediated alternative splicing events are dependent on JNK signaling. Strikingly, these JNK-dependent events are also significantly enriched for responsiveness to CELF2. Together, our data demonstrate a widespread role for the JNK–CELF2 axis in controlling splicing during T-cell activation, including a specific role in propagating JNK signaling.
Collapse
|
32
|
Zhu T, Zhao D, Song Z, Yuan Z, Li C, Wang Y, Zhou X, Yin X, Hassan MF, Yang L. HDAC6 alleviates prion peptide-mediated neuronal death via modulating PI3K-Akt-mTOR pathway. Neurobiol Aging 2015; 37:91-102. [PMID: 26507311 DOI: 10.1016/j.neurobiolaging.2015.09.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Revised: 09/12/2015] [Accepted: 09/29/2015] [Indexed: 02/06/2023]
Abstract
Histone deacetylase 6 (HDAC6) controls several major cellular responses to stress that play a role in neurodegenerative diseases, including aggresome formation, autophagy, and apoptosis. However, the specific role of HDAC6 in prion diseases is not known. In this study, we examined the relationship between HDAC6 and cellular response to the neurotoxic synthetic prion protein fragment PrP106-126. We determined that exposure of cerebral cortical neurons to this fragment alters the expression and localization of HDAC6. Suppression of HDAC6 activity or knockdown of HDAC6 expression exacerbates the neuronal cell death induced by PrP106-126, but that overexpression of HDAC6 alleviates PrP106-126-induced neuronal death. We also found that this protective effect of HDAC6 involves the activation of autophagy and modulation of PI3K-Akt-mammalian target of rapamycin (mTOR) signaling. Overexpression of HDAC6 in neurons-induced autophagy correlated with a reduction in phosphorylated mTOR and phosphorylated p70S6K in response to PrP106-126 stimulation, conversely, HDAC6 deficiency interfered with autophagy and increased phosphorylated mTOR and phosphorylated 70S6K. In addition, HDAC6 also appears to modulate the phosphorylation of Akt; overexpression of HDAC6 increased the phosphorylated Akt, but HDAC6 deficiency resulted in further reduction of phosphorylated Akt. Overall, we demonstrate that HDAC6 protects neurons from toxicity of prion peptide, and that this protection occurs at through the regulation of the PI3k-Akt-mTOR axis.
Collapse
Affiliation(s)
- Ting Zhu
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Deming Zhao
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zhiqi Song
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Zhen Yuan
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Chaosi Li
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Yunsheng Wang
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiangmei Zhou
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Xiaomin Yin
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Muhammad Farooque Hassan
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China
| | - Lifeng Yang
- State Key Laboratories for Agrobiotechnology, Key Lab of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Transmissible Spongiform Encephalopathy Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, China.
| |
Collapse
|
33
|
Eapen A, George A. Dentin phosphophoryn in the matrix activates AKT and mTOR signaling pathway to promote preodontoblast survival and differentiation. Front Physiol 2015; 6:221. [PMID: 26300786 PMCID: PMC4528161 DOI: 10.3389/fphys.2015.00221] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2015] [Accepted: 07/21/2015] [Indexed: 11/16/2022] Open
Abstract
Dentin phosphophoryn (DPP) is an extracellular matrix protein synthesized by odontoblasts. It is highly acidic and the phosphorylated protein possesses a strong affinity for calcium ions. Therefore, DPP in the extracellular matrix can promote hydroxyapatite nucleation and can regulate the size of the growing crystal. Besides its calcium binding property, DPP can initiate signaling functions from the ECM (Extracellular matrix). The signals that promote the cytodifferentiation of preodontoblasts to fully functional odontoblasts are not known. In this study, we demonstrate that preodontoblasts on a DPP matrix, generates mechanical and biochemical signals. This is initiated by the ligation of the integrins with the RGD containing DPP. The downstream biochemical response observed is the activation of the AKT(protein kinase B) and mTOR (mammalian target of rapamycin) signaling pathways leading to the activation of the transcription factor NF-κB (Nuclear factor κB). Terminal differentiation of the preodontoblasts was assessed by identifying phosphate and calcium deposits in the matrix using von Kossa and Alizarin red staining respectively. Identifying the signaling pathways initiated by DPP in the dentin matrix would help in devising strategies for dentin tissue engineering.
Collapse
Affiliation(s)
- Asha Eapen
- Brodie Tooth Development Genetics and Regenerative Medicine, Department of Oral Biology, University of Illinois at Chicago Chicago, IL, USA
| | - Anne George
- Brodie Tooth Development Genetics and Regenerative Medicine, Department of Oral Biology, University of Illinois at Chicago Chicago, IL, USA
| |
Collapse
|
34
|
Platani M, Trinkle-Mulcahy L, Porter M, Jeyaprakash AA, Earnshaw WC. Mio depletion links mTOR regulation to Aurora A and Plk1 activation at mitotic centrosomes. J Cell Biol 2015; 210:45-62. [PMID: 26124292 PMCID: PMC4494011 DOI: 10.1083/jcb.201410001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Coordination of cell growth and proliferation in response to nutrient supply is mediated by mammalian target of rapamycin (mTOR) signaling. In this study, we report that Mio, a highly conserved member of the SEACAT/GATOR2 complex necessary for the activation of mTORC1 kinase, plays a critical role in mitotic spindle formation and subsequent chromosome segregation by regulating the proper concentration of active key mitotic kinases Plk1 and Aurora A at centrosomes and spindle poles. Mio-depleted cells showed reduced activation of Plk1 and Aurora A kinase at spindle poles and an impaired localization of MCAK and HURP, two key regulators of mitotic spindle formation and known substrates of Aurora A kinase, resulting in spindle assembly and cytokinesis defects. Our results indicate that a major function of Mio in mitosis is to regulate the activation/deactivation of Plk1 and Aurora A, possibly by linking them to mTOR signaling in a pathway to promote faithful mitotic progression.
Collapse
Affiliation(s)
- Melpomeni Platani
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - Laura Trinkle-Mulcahy
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario K1H8M5, Canada Ottawa Institute of Systems Biology, University of Ottawa, Ottawa, Ontario K1H8M5, Canada
| | - Michael Porter
- Centre for Gene Regulation and Expression, College of Life Sciences, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - A Arockia Jeyaprakash
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| | - William C Earnshaw
- Wellcome Trust Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, Scotland, UK
| |
Collapse
|
35
|
Wang D, Wu X. In vitro and in vivo targeting of bladder carcinoma with metformin in combination with cisplatin. Oncol Lett 2015; 10:975-981. [PMID: 26622608 DOI: 10.3892/ol.2015.3267] [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: 08/15/2014] [Accepted: 04/14/2015] [Indexed: 12/28/2022] Open
Abstract
Bladder cancer is the ninth most common carcinoma worldwide, and improving the sensitivity of this cancer to chemotherapy is a current clinical challenge. Metformin is a potentially useful therapeutic agent for the treatment of certain types of cancer. In the present study, metformin and cisplatin (a first-line chemotherapeutic agent for the treatment of bladder cancer) were administered to T24 and BIU-87 bladder cancer cells lines alone or in combination, prior to undergoing MTT assay and fluorescence-activated cell sorting analysis to determine cell viability and cell cycle distribution, respectively. Western blotting was used to examine the expression of proteins associated with the AMP-activated protein kinase (AMPK) and mammalian target of rapamycin (mTOR) signaling pathways. In addition, a xenograft model was constructed to evaluate the antitumor efficacy of metformin and cisplatin treatment, alone or in combination. Immunohistochemistry was performed to detect the expression levels of proteins associated with xenograft growth and angiogenesis. Furthermore, western blotting was performed to observe the expression of proteins associated with the AKT/mTOR signaling pathway in the xenograft model. The results demonstrated that the treatment of T24 and BIU-87 cells with metformin or cisplatin resulted in decreased tumor cell proliferation. However, the joint application of metformin and cisplatin was significantly more effective than that of each compound alone (P<0.05). Similarly, cells more markedly accumulated in the sub-G1 phase following joint treatment with metformin and cisplatin, compared with metformin or cisplatin treatment alone. In addition, human cell cycle signaling pathway western blotting arrays were performed, which identified the marked downregulation of phosphorylated (p)-mTOR and unchanged expression of p-AMPK, AMPK and mTOR following combined treatment with cisplatin and metformin. Concurrently, combined use of metformin and cisplatin markedly inhibited the growth and angiogenesis of xenografts generated from BIU-87 cells. Immunohistochemical analysis revealed that downregulation of the expression of specific proteins associated with AMPK promoted xenograft growth and angiogenesis, while western blotting revealed inhibition of the AKT/mTOR signaling pathway in xenografts treated with metformin in combination with cisplatin. Overall, the results of the present study demonstrated that the concurrent administration of metformin and cisplatin may result in enhanced antitumor efficacy compared with that of one agent alone, thus, providing a potential novel therapeutic strategy for the treatment of bladder cell carcinoma.
Collapse
Affiliation(s)
- Dong Wang
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| | - Xiaohou Wu
- Department of Urology, The First Affiliated Hospital of Chongqing Medical University, Chongqing 400016, P.R. China
| |
Collapse
|
36
|
Han F, Lin S, Liu P, Liu X, Tao J, Deng X, Yi C, Xu H. Discovery of a Novel Series of Thienopyrimidine as Highly Potent and Selective PI3K Inhibitors. ACS Med Chem Lett 2015; 6:434-8. [PMID: 25893045 DOI: 10.1021/ml5005014] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 03/11/2015] [Indexed: 11/28/2022] Open
Abstract
Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway provides a promising new approach for cancer therapy. Through a rational design, a novel series of thienopyrimidine was discovered as highly potent and selective PI3K inhibitors. These thienopyrimidine derivatives were demonstrated to bear nanomolar PI3Kα inhibitory potency with over 100-fold selectivity against mTOR kinase. The lead compounds 6g and 6k showed good developability profiles in cell-based proliferation and ADME assays. In this communication, their design, synthesis, structure-activity relationship, selectivity, and some developability properties are described.
Collapse
Affiliation(s)
- Fangbin Han
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Songwen Lin
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Peng Liu
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Xiujie Liu
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Jing Tao
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Xiaobing Deng
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Chongqin Yi
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| | - Heng Xu
- PKUCare Pharmaceutical R&D Center, A106-109, Biotech Innovation Works, No. 29 Life Science Park Road, Changping District, Beijing 102206, P. R. China
| |
Collapse
|
37
|
Cha YL, Li PD, Yuan LJ, Zhang MY, Zhang YJ, Rao HL, Zhang HZ, Zheng XFS, Wang HY. EIF4EBP1 overexpression is associated with poor survival and disease progression in patients with hepatocellular carcinoma. PLoS One 2015; 10:e0117493. [PMID: 25658620 PMCID: PMC4319970 DOI: 10.1371/journal.pone.0117493] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2014] [Accepted: 12/24/2014] [Indexed: 01/20/2023] Open
Abstract
Objective EIF4EBP1 acts as a crucial effector in mTOR signaling pathway. Studies have suggested that EIF4EBP1 plays a critical role in carcinogenesis. However, the clinical significance and biological role of EIF4EBP1 in hepatocellular carcinoma (HCC) have not been elucidated. Therefore, we aimed to investigate the clinical significance of EIF4EBP1 in HCC. Methods Total 128 cases of HCCs were included in this study. EIF4EBP1 expression in HCC tissues was detected by qRT-PCR, Western blot and immunohistochemistry, respectively. Then the relationships between EIF4EBP1 expression and clinical features as well as survival were analyzed. Results The expression level of EIF4EBP1 mRNA is significantly higher in 60% (24/40) of fresh HCC tissues than that in the matched adjacent nontumor liver (NCL) tissues (P = 0.044). Similarly, EIF4EBP1 protein is notably upregulated in 8 HCC tissues (randomly selected from the 40 HCCs) measured by Western blot and is significantly increased in another 88 paraffin-embedded HCCs (53%, 47/88) by immunohistochemistry compared with the matched NCLs (P < 0.001). EIF4EBP1 protein expression in HCC tissues is significantly correlated with serum AFP (P = 0.003) and marginally significantly associated with pathological grade (P = 0.085), tumor number (P = 0.084), tumor embolus (P = 0.084) and capsulation (P = 0.073). Patients with higher EIF4EBP1 protein expression have a much worse 5-year overall survival (40.3% vs 73.6%) and 5-year disease-free survival (33.0% vs 49.0%) than those with low expression. Furthermore, Cox regression analysis shows that EIF4EBP1 protein is an independent prognostic factor for overall survival (HR, 2.285; 95% CI, 1.154–4.527; P = 0.018) and disease-free survival (HR, 1.901; 95% CI, 1.067–3.386; P = 0.029) in HCC patients. Conclusions Our results demonstrate for the first time that EIF4EBP1 mRNA and protein are markedly up-regulated in HCC tissues, and the protein overexpression is significantly associated with poor survival and progression, which provide a potential new prognostic marker and therapeutic target for HCC patients.
Collapse
Affiliation(s)
- Yin-Lian Cha
- State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- National Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Pin-Dong Li
- State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- National Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Lin-Jing Yuan
- State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- National Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Mei-Yin Zhang
- State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- National Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Yao-Jun Zhang
- Department of Hepatobiliary Oncology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Hui-Lan Rao
- Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - Hui-Zhong Zhang
- Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
| | - X. F. Steven Zheng
- Rutgers Cancer Institute of New Jersey, Rutgers University, New Brunswick, New Jersey, United States of America
| | - Hui-Yun Wang
- State Key Laboratory of Oncology in Southern China, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- National Collaborative Innovation Center for Cancer Medicine, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong, China
- * E-mail:
| |
Collapse
|
38
|
Combined regulation of mTORC1 and lysosomal acidification by GSK-3 suppresses autophagy and contributes to cancer cell growth. Oncogene 2014; 34:4613-23. [PMID: 25500539 DOI: 10.1038/onc.2014.390] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Revised: 10/10/2014] [Accepted: 10/16/2014] [Indexed: 12/11/2022]
Abstract
There is controversy over the role of glycogen synthase kinase-3 (GSK-3) in cancer progression. Recent work has implicated GSK-3 in the regulation of mammalian target of rapamycin (mTOR), a known player in malignant transformation. Autophagy, a self-degradation pathway, is inhibited by mTOR and is tightly associated with cell survival and tumor growth. Here we show that GSK-3 suppresses autophagy via mTOR complex-1 (mTORC1) and lysosomal regulation. We show that overexpression of GSK-3 isoforms (GSK-3α and GSK-3β) activated mTORC1 and suppressed autophagy in MCF-7 human breast cancer cells as indicated by reduced beclin-1 levels and upregulation of sequestosome 1 (p62/SQSTM1). Further, overexpression of GSK-3 increased the number of autophagosomes and inhibited autophagic flux. This activity was directly related to reduced lysosomal acidification triggered by GSK-3 (in which GSK-3β has a stronger impact). We found that lysosomal acidification is reduced in MCF-7 cells that also exhibit increased levels of autophagosomes and p62/SQSTM1 and increased activity of mTORC1. Subsequently, treating cells with GSK-3 inhibitors restored lysosomal acidification, enhanced autophagic flux and inhibited mTORC1. Furthermore, GSK-3 inhibitors inhibited cell proliferation. We provide evidence that GSK3-mediated mTORC1 activity and GSK-3-mediated lysosomal acidification occur via distinct pathways, yet both mTORC1 and lysosomes control cell growth. Finally, we show that GSK-3-reduced lysosomal acidification inhibits endocytic clearance as demonstrated by reduced endocytic degradation of the epidermal growth factor receptor. Taken together, our study places GSK-3 as a key regulator coordinating cellular homeostasis. GSK-3 inhibitors may be useful in targeting mTORC1 and lysosomal acidification for cancer therapy.
Collapse
|
39
|
Deivasigamani S, Verma HK, Ueda R, Ratnaparkhi A, Ratnaparkhi GS. A genetic screen identifies Tor as an interactor of VAPB in a Drosophila model of amyotrophic lateral sclerosis. Biol Open 2014; 3:1127-38. [PMID: 25361581 PMCID: PMC4232771 DOI: 10.1242/bio.201410066] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic Lateral Sclerosis (ALS) is a progressive neurodegenerative disorder characterized by selective death of motor neurons. In 5–10% of the familial cases, the disease is inherited because of mutations. One such mutation, P56S, was identified in human VAPB that behaves in a dominant negative manner, sequestering wild type protein into cytoplasmic inclusions. We have conducted a reverse genetic screen to identify interactors of Drosophila VAPB. We screened 2635 genes and identified 103 interactors, of which 45 were enhancers and 58 were suppressors of VAPB function. Interestingly, the screen identified known ALS loci – TBPH, alsin2 and SOD1. Also identified were genes involved in cellular energetics and homeostasis which were used to build a gene regulatory network of VAPB modifiers. One key modifier identified was Tor, whose knockdown reversed the large bouton phenotype associated with VAP(P58S) expression in neurons. A similar reversal was seen by over-expressing Tuberous Sclerosis Complex (Tsc1,2) that negatively regulates TOR signaling as also by reduction of S6K activity. In comparison, the small bouton phenotype associated with VAP(wt) expression was reversed with Tsc1 knock down as well as S6K-CA expression. Tor therefore interacts with both VAP(wt) and VAP(P58S), but in a contrasting manner. Reversal of VAP(P58S) bouton phenotypes in larvae fed with the TOR inhibitor Rapamycin suggests upregulation of TOR signaling in response to VAP(P58S) expression. The VAPB network and further mechanistic understanding of interactions with key pathways, such as the TOR cassette, will pave the way for a better understanding of the mechanisms of onset and progression of motor neuron disease.
Collapse
Affiliation(s)
| | | | - Ryu Ueda
- National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan
| | | | | |
Collapse
|
40
|
Koide H, Asai T, Kato H, Yonenaga N, Yokota M, Ando H, Dewa T, Nango M, Maeda N, Oku N. Susceptibility of PTEN-positive metastatic tumors to small interfering RNA targeting the mammalian target of rapamycin. NANOMEDICINE-NANOTECHNOLOGY BIOLOGY AND MEDICINE 2014; 11:185-94. [PMID: 25240598 DOI: 10.1016/j.nano.2014.09.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/02/2014] [Accepted: 09/11/2014] [Indexed: 01/10/2023]
Abstract
PTEN-positive tumors are not susceptible to the treatment with rapamycin, an inhibitor of the mammalian target of rapamycin (mTOR). Here, we determined the susceptibility of PTEN-positive cells to small interfering RNA for mTOR (si-mTOR) by using a novel liposomal delivery system. We prepared dicetyl phosphate-tetraethylenepentamine-based polycation liposomes (TEPA-PCL) decorated with polyethylene glycol (PEG) grafting Ala-Pro-Arg-Pro-Gly (APRPG), a VRGFR-1-targeting peptide. APRPG-PEG-decorated TEPA-PCL carrying si-mTOR (APRPG-TEPA-PCL/si-mTOR) had an antiproliferative effect against B16F10 murine melanoma cells (PTEN-positive) and significantly inhibited both the proliferation and tube formation of mouse 2H-11 endothelial-like cells (PTEN-positive). APRPG-TEPA-PCL/si-mTOR treatment did not induce Akt phosphorylation (Ser473) in either B16F10 or 2H-11 cells although there was strong phosphorylation of Akt in response to rapamycin treatment. Intravenous injection of APRPG-TEPA-PCL/si-mTOR significantly suppressed the tumor growth compared with rapamycin treatment in mice bearing B16F10 melanoma. These findings suggest that APRPG-TEPA-PCL/si-mTOR is useful for the treatment of PTEN-positive tumors.
Collapse
Affiliation(s)
- Hiroyuki Koide
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Tomohiro Asai
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Hiroki Kato
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Norihito Yonenaga
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Masafumi Yokota
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Hidenori Ando
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan
| | - Takehisa Dewa
- Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan
| | - Mamoru Nango
- Materials Science and Engineering, Nagoya Institute of Technology, Nagoya, Aichi, Japan
| | | | - Naoto Oku
- Department of Medical Biochemistry, University of Shizuoka School of Pharmaceutical Sciences, Shizuoka, Shizuoka, Japan.
| |
Collapse
|
41
|
Lee SE, Kim EY, Choi HY, Moon JJ, Park MJ, Lee JB, Jeong CJ, Park SP. Rapamycin rescues the poor developmental capacity of aged porcine oocytes. ASIAN-AUSTRALASIAN JOURNAL OF ANIMAL SCIENCES 2014; 27:635-47. [PMID: 25049998 PMCID: PMC4093196 DOI: 10.5713/ajas.2013.13816] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Revised: 01/22/2014] [Accepted: 02/21/2014] [Indexed: 11/27/2022]
Abstract
Unfertilized oocytes age inevitably after ovulation, which limits their fertilizable life span and embryonic development. Rapamycin affects mammalian target of rapamycin (mTOR) expression and cytoskeleton reorganization during oocyte meiotic maturation. The goal of this study was to examine the effects of rapamycin treatment on aged porcine oocytes and their in vitro development. Rapamycin treatment of aged oocytes for 24 h (68 h in vitro maturation [IVM]; 44 h+10 μM rapamycin/24 h, 47.52±5.68) or control oocytes (44 h IVM; 42.14±4.40) significantly increased the development rate and total cell number compared with untreated aged oocytes (68 h IVM, 22.04±5.68) (p<0.05). Rapamycin treatment of aged IVM oocytes for 24 h also rescued aberrant spindle organization and chromosomal misalignment, blocked the decrease in the level of phosphorylated-p44/42 mitogen-activated protein kinase (MAPK), and increased the mRNA expression of cytoplasmic maturation factor genes (MOS, BMP15, GDF9, and CCNB1) compared with untreated, 24 h-aged IVM oocytes (p<0.05). Furthermore, rapamycin treatment of aged oocytes decreased reactive oxygen species (ROS) activity and DNA fragmentation (p<0.05), and downregulated the mRNA expression of mTOR compared with control or untreated aged oocytes. By contrast, rapamycin treatment of aged oocytes increased mitochondrial localization (p<0.05) and upregulated the mRNA expression of autophagy (BECN1, ATG7, MAP1LC3B, ATG12, GABARAP, and GABARAPL1), anti-apoptosis (BCL2L1 and BIRC5; p<0.05), and development (NANOG and SOX2; p<0.05) genes, but it did not affect the mRNA expression of pro-apoptosis genes (FAS and CASP3) compared with the control. This study demonstrates that rapamycin treatment can rescue the poor developmental capacity of aged porcine oocytes.
Collapse
Affiliation(s)
- Seung Eun Lee
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea
| | - Eun Young Kim
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea ; Miraebio Research Institute, Mirae Biotech, Seoul 143-854, Korea
| | - Hyun Yong Choi
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea
| | - Jeremiah Jiman Moon
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea ; Faculty of Biotechnology, College of Applied Life Science, Jeju National University, Jeju 690-756, Korea
| | - Min Jee Park
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea ; Miraebio Research Institute, Mirae Biotech, Seoul 143-854, Korea . ; Faculty of Biotechnology, College of Applied Life Science, Jeju National University, Jeju 690-756, Korea
| | | | | | - Se Pill Park
- Stem Cell Research Center, Jeju National University, Jeju 690-756, Korea ; Miraebio Research Institute, Mirae Biotech, Seoul 143-854, Korea . ; Faculty of Biotechnology, College of Applied Life Science, Jeju National University, Jeju 690-756, Korea
| |
Collapse
|
42
|
LL-37 attenuates inflammatory impairment via mTOR signaling-dependent mitochondrial protection. Int J Biochem Cell Biol 2014; 54:26-35. [PMID: 24984264 DOI: 10.1016/j.biocel.2014.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 06/02/2014] [Accepted: 06/21/2014] [Indexed: 11/21/2022]
Abstract
The human cationic antimicrobial protein LL-37 is a multifunctional host defense peptide with a wide range of immunomodulatory activities. Previous work has shown that LL-37 exerts both pro- and anti-inflammatory effects. The role of mitochondria in the skin inflammatory effects of LL-37 has not been well studied. Therefore, our aim was to investigate the immunomodulatory effect of LL-37 in HaCaT cells and to delineate the underlying mechanisms related to mitochondrial function. Immunohistochemistry results from tissue microarrays showed strong cytoplasmic LL-37 staining in inflammatory cells in chronic dermatic inflammation. Using exogenous LL-37 stimulation and LL-37 knockdown and overexpression, LL-37 was demonstrated to dramatically reduce the mRNA levels and protein secretion of inflammatory cytokines including IL-6, IL-8, IL-1α and tumor necrosis factor-α (TNF-α), which are induced by lipopolysaccharides (LPS). The anti-inflammatory effects of LL-37 are dependent upon its ability to increase mitochondrial biogenesis and to maintain mitochondrial homeostasis. Furthermore, we observed that LL-37 enhances the LPS-induced phosphorylation of extracellular signal-regulated kinase (ERK1/2) and mammalian target of rapamycin (mTOR). The mTOR inhibitor rapamycin can neutralize the protective effects of LL-37 on mitochondria. In conclusion, these results suggest that high LL-37 expression levels correlate with chronic skin inflammation; mitochondrial dysfunction occurs in HaCaT cells during inflammation; and LL-37 attenuates inflammatory impairment by stimulating mitochondrial biogenesis and protecting mitochondrial function, which are dependent upon mTOR signaling. These findings provide new insights into targeting mitochondria with LL-37 to prevent skin inflammatory reactions.
Collapse
|
43
|
Shu Q, Xu Y, Zhuang H, Fan J, Sun Z, Zhang M, Xu G. Ras homolog enriched in the brain is linked to retinal ganglion cell apoptosis after light injury in rats. J Mol Neurosci 2014; 54:243-51. [PMID: 24664437 DOI: 10.1007/s12031-014-0281-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2013] [Accepted: 03/03/2014] [Indexed: 10/25/2022]
Abstract
Ras homolog enriched in the brain (Rheb) is a small GTPase of the Ras family. It has been confirmed that Rheb activation not only regulates cell growth and migration but also induces neuron apoptosis after toxic stimuli. However, the function of Rheb in the retina is still not fully understood. To find out whether Rheb was involved in retinal neuron death, the expression profile of Rheb in light-damaged retinal ganglion cells (RGCs) of adult rats was investigated. Western blotting showed the expression of Rheb was significantly upregulated in the injured retina. Rheb was mainly detected in apoptotic RGCs by using double immunofluorescent staining. Active caspase-3 was upregulated and co-labeled with Rheb. Meanwhile, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) showed that Rheb-positive RGCs underwent apoptosis after light exposure, which suggested that Rheb might be relevant to RGC apoptosis following phototoxicity. Furthermore, Western blotting and immunofluorescence showed that the expression profiles of CyclinD1 and cyclin-dependent kinase 4 (CDK4) were parallel with that of Rheb in a time-space dependent manner. Based on this study, it is speculated that Rheb might play an important role in physiological and pathological process in light-induced retina damage, which might provide a potential therapeutic avenue of retinal degeneration.
Collapse
Affiliation(s)
- Qinmeng Shu
- Department of Ophthalmology and Vision Sciences and Key Laboratory of Myopia of State Health Ministry, Eye and ENT Hospital, Shanghai Medical College, Fudan University, No.83 Fenyang Road, Shanghai, People's Republic of China
| | | | | | | | | | | | | |
Collapse
|
44
|
Assessment of the biological pathways targeted by isocyanate using N-succinimidyl N-methylcarbamate in budding yeast Saccharomyces cerevisiae. PLoS One 2014; 9:e92993. [PMID: 24664350 PMCID: PMC3963962 DOI: 10.1371/journal.pone.0092993] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Accepted: 02/27/2014] [Indexed: 02/05/2023] Open
Abstract
Isocyanates, a group of low molecular weight aromatic and aliphatic compounds possesses the functional isocyanate group. They are highly toxic in nature hence; we used N-succinimidyl N-methylcarbamate (NSNM), a surrogate chemical containing a functional isocyanate group to understand the mode of action of this class of compounds. We employed budding yeast Saccharomyces cerevisiae as a model organism to study the pathways targeted by NSNM. Our screening with yeast mutants revealed that it affects chromatin, DNA damage response, protein-ubiquitylation and chaperones, oxidative stress, TOR pathway and DNA repair processes. We also show that NSNM acts as an epigenetic modifier as its treatment causes reduction in global histone acetylation and formation of histone adducts. Cells treated with NSNM exhibited increase in mitochondrial membrane potential as well as intracellular ROS levels and the effects were rescued by addition of reduced glutathione to the medium. We also report that deletion of SOD1 and SOD2, the superoxide dismutase in Saccharomyces cerevisiae displayed hypersensitivity to NSNM. Furthermore, NSNM treatment causes rapid depletion of total glutathione and reduced glutathione. We also demonstrated that NSNM induces degradation of Sml1, a ribonucleotide reductase inhibitor involved in regulating dNTPs production. In summary, we define the various biological pathways targeted by isocyanates.
Collapse
|
45
|
Abstract
Sarcomas are tumors of mesenchymal origin that make up approximately 1% of human cancers. They may arise as primary tumors in either bone or soft tissue, with approximately 11,280 soft tissue tumors and 2,650 bone tumors diagnosed each year in the United States. There are at least 50 different subtypes of soft tissue sarcoma, with new ones described with ever-increasing frequency. One way to look at sarcomas is to divide them into categories on the basis of their genetic make-up. One group of sarcomas has an identifiable, relatively simple genetic signature, such as the X:18 translocation seen in synovial sarcoma or the 11:22 translocation seen in Ewing's sarcoma. These specific abnormalities often lead to the presence of fusion proteins, such as EWS-FLI1 in Ewing's sarcoma, which are helpful as diagnostic tools and may become therapeutic targets in the future. Another group of sarcomas is characterized by complex genetic abnormalities as seen in leiomyosarcoma, osteosarcoma, and undifferentiated sarcoma. It is important to keep these distinctions in mind when contemplating the development of targeted agents for sarcomas. Different abnormalities in sarcoma could be divided by tumor subtype or by the molecular or pathway abnormality. However, some existing drugs or drugs in development may interfere with or alter more than one of the presented pathways.
Collapse
Affiliation(s)
- Charles Forscher
- Sarcoma Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| | - Monica Mita
- Experimental Therapeutics Program, Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center Los Angeles, CA, USA
| | - Robert Figlin
- Academic Development Program, Samuel Oschin Comprehensive Cancer Institute, and Division of Hematology/Oncology, Cedars-Sinai Medical Center, Los Angeles, CA, USA
| |
Collapse
|
46
|
Lu Q, Gao L, Huang L, Ruan L, Yang J, Huang W, Li Z, Zhang Y, Jin K, Zhuge Q. Inhibition of mammalian target of rapamycin improves neurobehavioral deficit and modulates immune response after intracerebral hemorrhage in rat. J Neuroinflammation 2014; 11:44. [PMID: 24602288 PMCID: PMC3975837 DOI: 10.1186/1742-2094-11-44] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2013] [Accepted: 02/21/2014] [Indexed: 02/05/2023] Open
Abstract
Background Mammalian target of rapamycin (mTOR), a serine/threonine kinase, regulates many processes, including cell growth and the immune response. mTOR is also dysregulated in several neurological diseases, such as traumatic brain injury (TBI), stroke, and neurodegenerative disease. However, the role of mTOR in intracerebral hemorrhage (ICH) remains unexplored. The aims of our study were to determine whether inhibiting mTOR signaling could affect the outcome after ICH and to investigate the possible underlying mechanism. Methods A rat ICH model was induced by intracerebral injection of collagenase IV into the striatum, and mTOR activation was inhibited by administration of rapamycin. mTOR signaling activation was determined by western blotting. Neurobehavioral deficit after ICH was determined by a set of modified Neurological Severity Scores (mNSS). The levels of CD4+CD25+Foxp3+ regulatory T cells (Tregs) and cytokines were examined using flow cytometry and ELISA, respectively. Results Our results demonstrated thatmTOR signaling was activated 30 minutes and returned to its basal level 1 day after ICH. Increased p-mTOR, which mean that mTOR signaling was activated, was predominantly located around the hematoma. Rapamycin treatment significantly improved the neurobehavioral deficit after ICH, increased the number of Tregs, increased levels of interleukin-10 and transforming growth factor-β and reduced interferon-γ both in peripheral blood and brain. Conclusions Our study suggests that mTOR improves ICH outcome and modulates immune response after ICH.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Qichuan Zhuge
- Department of Neurosurgery, First Affiliated Hospital of Wenzhou Medical University, Wenzhou, Zhejiang, China.
| |
Collapse
|
47
|
Weston MC, Chen H, Swann JW. Loss of mTOR repressors Tsc1 or Pten has divergent effects on excitatory and inhibitory synaptic transmission in single hippocampal neuron cultures. Front Mol Neurosci 2014; 7:1. [PMID: 24574959 DOI: 10.3389/fnmol.2014.00001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Accepted: 01/09/2014] [Indexed: 01/23/2023] Open
Abstract
The Pten and Tsc1 genes both encode proteins that repress mechanistic target of rapamycin (mTOR) signaling. Disruption of either gene in the brain results in epilepsy and autism-like symptoms in humans and mouse models, therefore it is important to understand the molecular and physiological events that lead from gene disruption to disease phenotypes. Given the similar roles these two molecules play in the regulation of cellular growth and the overlap in the phenotypes that result from their loss, we predicted that the deletion of either the Pten or Tsc1 gene from autaptic hippocampal neurons would have similar effects on neuronal morphology and synaptic transmission. Accordingly, we found that loss of either Pten or Tsc1 caused comparable increases in soma size, dendrite length and action potential properties. However, the effects of Pten and Tsc1 loss on synaptic transmission were different. Loss of Pten lead to an increase in both excitatory and inhibitory neurotransmission, while loss of Tsc1 did not affect excitatory neurotransmission and reduced inhibitory transmission by decreasing mIPSC amplitude. Although the loss of Pten or Tsc1 both increased downstream mTORC1 signaling, phosphorylation of Akt was increased in Pten-ko and decreased in Tsc1-ko neurons, potentially accounting for the different effects on synaptic transmission. Despite the different effects at the synaptic level, our data suggest that loss of Pten or Tsc1 may both lead to an increase in the ratio of excitation to inhibition at the network level, an effect that has been proposed to underlie both epilepsy and autism.
Collapse
Affiliation(s)
- Matthew C Weston
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
| | - Hongmei Chen
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
| | - John W Swann
- The Cain Foundation Laboratories, The Jan and Dan Duncan Neurological Research Institute Houston, TX, USA ; Departments of Neuroscience and Pediatrics, Baylor College of Medicine Houston, TX, USA
| |
Collapse
|
48
|
Pellicioli ACA, Martins MD, Dillenburg CS, Marques MM, Squarize CH, Castilho RM. Laser phototherapy accelerates oral keratinocyte migration through the modulation of the mammalian target of rapamycin signaling pathway. JOURNAL OF BIOMEDICAL OPTICS 2014; 19:028002. [PMID: 24531144 DOI: 10.1117/1.jbo.19.2.028002] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/17/2014] [Indexed: 06/03/2023]
Abstract
Keratinocytes play a central role in wound healing by responding to tissue injury through the activation of cellular proliferation and migration. Current clinical evidence suggests that the laser phototherapy (LPT) accelerates wound healing in a variety of oral diseases; however, the molecular mechanisms involved in response to LPT are not fully understood. Oral keratinocytes (NOK-SI) maintained under nutritional-deficit culture medium (2% fetal bovine serum) were irradiated with InGaAlP laser (660 nm; 40 mW; 0.04 cm2 spot size) in punctual and contact modes. The energy densities used were 4 and 20 J/cm2 corresponding to 4 and 20 s of exposure times and 0.16 and 0.8 J of energy per point, respectively. Three sessions of irradiations were applied with 6-h intervals. Further, the impact of LPT over cellular migration, proliferation, and activation of the mammalian target of rapamycin (mTOR) pathway, known to play a major role in epithelial migration and wound healing, was analyzed. Compared with control cells, the LPT-treated cells showed accelerated cellular migration without any changes in proliferation. Furthermore, LPT resulted in an increase in the phospho-S6 ribosomal protein, indicating activation of the mTOR signaling pathway. Collectively, these findings suggest that the LPT activates mTOR signaling pathway, promotes epithelial cell migration, and accelerates healing of oral mucosa.
Collapse
Affiliation(s)
- Ana Carolina Amorim Pellicioli
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Manoela Domingues Martins
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Caroline Siviero Dillenburg
- Universidade Federal do Rio Grande do Sul, School of Dentistry, Department of Oral Pathology, Porto Alegre, Rio Grande do Sul 90035-003, Brazil
| | - Márcia Martins Marques
- University of São Paulo, School of Dentistry, Department of Dentistry, São Paulo, São Paulo 05508-000, Brazil
| | - Cristiane H Squarize
- University of Michigan, School of Dentistry, Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, Ann Arbor, Michigan 48109-1078
| | - Rogerio M Castilho
- University of Michigan, School of Dentistry, Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, Ann Arbor, Michigan 48109-1078
| |
Collapse
|
49
|
Identification of novel 7-amino-5-methyl-1,6-naphthyridin-2(1H)-one derivatives as potent PI3K/mTOR dual inhibitors. Bioorg Med Chem Lett 2014; 24:790-3. [PMID: 24433860 DOI: 10.1016/j.bmcl.2013.12.112] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2013] [Revised: 12/23/2013] [Accepted: 12/24/2013] [Indexed: 12/24/2022]
Abstract
Inhibition of the phosphoinositide 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) signaling pathway is one of the most intensively studied approaches to cancer therapy. Rational design led to the identification of novel 7-amino-5-methyl-1,6-naphthyridin-2(1H)-one derivatives as potent PI3K/mTOR dual inhibitors. Design, synthesis and structure activity relationship are reported.
Collapse
|
50
|
Kawatani M, Osada H. Affinity-based target identification for bioactive small molecules. MEDCHEMCOMM 2014. [DOI: 10.1039/c3md00276d] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
A variety of new approaches of affinity-based target identification for bioactive small molecules are being developed, facilitating drug development and understanding complicated biological processes.
Collapse
|