1
|
Herneisen AL, Peters ML, Smith TA, Shortt E, Lourido S. SPARK regulates AGC kinases central to the Toxoplasma gondii asexual cycle. eLife 2024; 13:RP93877. [PMID: 39136687 PMCID: PMC11321763 DOI: 10.7554/elife.93877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/15/2024] Open
Abstract
Apicomplexan parasites balance proliferation, persistence, and spread in their metazoan hosts. AGC kinases, such as PKG, PKA, and the PDK1 ortholog SPARK, integrate environmental signals to toggle parasites between replicative and motile life stages. Recent studies have cataloged pathways downstream of apicomplexan PKG and PKA; however, less is known about the global integration of AGC kinase signaling cascades. Here, conditional genetics coupled to unbiased proteomics demonstrates that SPARK complexes with an elongin-like protein to regulate the stability of PKA and PKG in the model apicomplexan Toxoplasma gondii. Defects attributed to SPARK depletion develop after PKG and PKA are down-regulated. Parasites lacking SPARK differentiate into the chronic form of infection, which may arise from reduced activity of a coccidian-specific PKA ortholog. This work delineates the signaling topology of AGC kinases that together control transitions within the asexual cycle of this important family of parasites.
Collapse
Affiliation(s)
- Alice L Herneisen
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Michelle L Peters
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Tyler A Smith
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Emily Shortt
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of TechnologyCambridgeUnited States
| |
Collapse
|
2
|
Rosen N, Mukherjee R, Pancholi P, Sharma M, Solomon H, Timaul M, Thant C, McGriskin R, Hayatt O, Markov V, D'Allara J, Bekker S, Candelier J, Carrasco S, de Stanchina E, Vanaja K. Diet induced insulin resistance is due to induction of PTEN expression. RESEARCH SQUARE 2024:rs.3.rs-4021885. [PMID: 38978604 PMCID: PMC11230483 DOI: 10.21203/rs.3.rs-4021885/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
Type 2 Diabetes (T2D) is a condition that is often associated with obesity and defined by reduced sensitivity of PI3K signaling to insulin (insulin resistance), hyperinsulinemia and hyperglycemia. Molecular causes and early signaling events underlying insulin resistance are not well understood. Insulin activation of PI3K signaling causes mTOR dependent induction of PTEN translation, a negative regulator of PI3K signaling. We speculated that insulin resistance is due to insulin dependent induction of PTEN protein that prevent further increases in PI3K signaling. Here we show that in a diet induced model of obesity and insulin resistance, PTEN levels are increased in fat, muscle and liver tissues. Onset of hyperinsulinemia and PTEN induction in tissue is followed by hyperglycemia, hepatic steatosis and severe glucose intolerance. Treatment with a PTEN phosphatase inhibitor prevents and reverses these phenotypes, whereas an mTORC1 kinase inhibitor reverses all but the hepatic steatosis. These data suggest that induction of PTEN by increasing levels of insulin elevates feedback inhibition of the pathway to a point where downstream PI3K signaling is reduced and hyperglycemia ensues. PTEN induction is thus necessary for insulin resistance and the type 2 diabetes phenotype and a potential therapeutic target.
Collapse
|
3
|
Herneisen AL, Peters ML, Smith TA, Shortt E, Lourido S. SPARK regulates AGC kinases central to the Toxoplasma gondii asexual cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.30.564746. [PMID: 37961644 PMCID: PMC10634940 DOI: 10.1101/2023.10.30.564746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Apicomplexan parasites balance proliferation, persistence, and spread in their metazoan hosts. AGC kinases, such as PKG, PKA, and the PDK1 ortholog SPARK, integrate environmental signals to toggle parasites between replicative and motile life stages. Recent studies have cataloged pathways downstream of apicomplexan PKG and PKA; however, less is known about the global integration of AGC kinase signaling cascades. Here, conditional genetics coupled to unbiased proteomics demonstrates that SPARK complexes with an elongin-like protein to regulate the stability of PKA and PKG in the model apicomplexan Toxoplasma gondii. Defects attributed to SPARK depletion develop after PKG and PKA are down-regulated. Parasites lacking SPARK differentiate into the chronic form of infection, which may arise from reduced activity of a coccidian-specific PKA ortholog. This work delineates the signaling topology of AGC kinases that together control transitions within the asexual cycle of this important family of parasites.
Collapse
Affiliation(s)
- Alice L. Herneisen
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Michelle L. Peters
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Tyler A. Smith
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Emily Shortt
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| | - Sebastian Lourido
- Whitehead Institute for Biomedical Research and Department of Biology, Massachusetts Institute of Technology, Cambridge, MA
| |
Collapse
|
4
|
Li M, Wu X, Pan Y, Song M, Yang X, Xu J, Plikus MV, Lv C, Yu L, Yu Z. mTORC2-AKT signaling to PFKFB2 activates glycolysis that enhances stemness and tumorigenicity of intestinal epithelial cells. FASEB J 2024; 38:e23532. [PMID: 38451470 DOI: 10.1096/fj.202301833rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Revised: 01/31/2024] [Accepted: 02/19/2024] [Indexed: 03/08/2024]
Abstract
Although elevated glycolysis has been widely recognized as a hallmark for highly proliferating cells like stem cells and cancer, its regulatory mechanisms are still being updated. Here, we found a previously unappreciated mechanism of mammalian target of rapamycin complex 2 (mTORC2) in regulating glycolysis in intestinal stem cell maintenance and cancer progression. mTORC2 key subunits expression levels and its kinase activity were specifically upregulated in intestinal stem cells, mouse intestinal tumors, and human colorectal cancer (CRC) tissues. Genetic ablation of its key scaffolding protein Rictor in both mouse models and cell lines revealed that mTORC2 played an important role in promoting intestinal stem cell proliferation and self-renewal. Moreover, utilizing mouse models and organoid culture, mTORC2 loss of function was shown to impair growth of gut adenoma and tumor organoids. Based on these findings, we performed RNA-seq and noticed significant metabolic reprogramming in Rictor conditional knockout mice. Among all the pathways, carbohydrate metabolism was most profoundly altered, and further studies demonstrated that mTORC2 promoted glycolysis in intestinal epithelial cells. Most importantly, we showed that a rate-limiting enzyme in regulating glycolysis, 6-phosphofructo-2-kinase (PFKFB2), was a direct target for the mTORC2-AKT signaling. PFKFB2 was phosphorylated upon mTORC2 activation, but not mTORC1, and this process was AKT-dependent. Together, this study has identified a novel mechanism underlying mTORC2 activated glycolysis, offering potential therapeutic targets for treating CRC.
Collapse
Affiliation(s)
- Mengzhen Li
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xi Wu
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yuwei Pan
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Manyu Song
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xu Yang
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Jiuzhi Xu
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Maksim V Plikus
- Department of Developmental and Cell Biology, Sue and Bill Gross Stem Cell Research Center, Center for Complex Biological Systems, University of California, Irvine, Irvine, California, USA
| | - Cong Lv
- Key Laboratory of Precision Nutrition and Food Quality, Ministry of Education, Department of Nutrition and Health, China Agricultural University, Beijing, China
| | - Lu Yu
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Zhengquan Yu
- Tianjian Laboratory of Advanced Biomedical Sciences, Academy of Medical Sciences, Zhengzhou University, Zhengzhou, Henan, China
- State Key Laboratory of Animal Biotech Breeding, College of Biological Sciences, China Agricultural University, Beijing, China
| |
Collapse
|
5
|
Ragupathi A, Kim C, Jacinto E. The mTORC2 signaling network: targets and cross-talks. Biochem J 2024; 481:45-91. [PMID: 38270460 PMCID: PMC10903481 DOI: 10.1042/bcj20220325] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/29/2023] [Accepted: 12/18/2023] [Indexed: 01/26/2024]
Abstract
The mechanistic target of rapamycin, mTOR, controls cell metabolism in response to growth signals and stress stimuli. The cellular functions of mTOR are mediated by two distinct protein complexes, mTOR complex 1 (mTORC1) and mTORC2. Rapamycin and its analogs are currently used in the clinic to treat a variety of diseases and have been instrumental in delineating the functions of its direct target, mTORC1. Despite the lack of a specific mTORC2 inhibitor, genetic studies that disrupt mTORC2 expression unravel the functions of this more elusive mTOR complex. Like mTORC1 which responds to growth signals, mTORC2 is also activated by anabolic signals but is additionally triggered by stress. mTORC2 mediates signals from growth factor receptors and G-protein coupled receptors. How stress conditions such as nutrient limitation modulate mTORC2 activation to allow metabolic reprogramming and ensure cell survival remains poorly understood. A variety of downstream effectors of mTORC2 have been identified but the most well-characterized mTORC2 substrates include Akt, PKC, and SGK, which are members of the AGC protein kinase family. Here, we review how mTORC2 is regulated by cellular stimuli including how compartmentalization and modulation of complex components affect mTORC2 signaling. We elaborate on how phosphorylation of its substrates, particularly the AGC kinases, mediates its diverse functions in growth, proliferation, survival, and differentiation. We discuss other signaling and metabolic components that cross-talk with mTORC2 and the cellular output of these signals. Lastly, we consider how to more effectively target the mTORC2 pathway to treat diseases that have deregulated mTOR signaling.
Collapse
Affiliation(s)
- Aparna Ragupathi
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Christian Kim
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| | - Estela Jacinto
- Department of Biochemistry and Molecular Biology, Robert Wood Johnson Medical School, Rutgers University, New Brunswick, NJ, U.S.A
| |
Collapse
|
6
|
Domma AJ, Henderson LA, Goodrum FD, Moorman NJ, Kamil JP. Human cytomegalovirus attenuates AKT activity by destabilizing insulin receptor substrate proteins. J Virol 2023; 97:e0056323. [PMID: 37754763 PMCID: PMC10617551 DOI: 10.1128/jvi.00563-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 08/09/2023] [Indexed: 09/28/2023] Open
Abstract
IMPORTANCE Human cytomegalovirus (HCMV) requires inactivation of AKT to efficiently replicate, yet how AKT is shut off during HCMV infection has remained unclear. We show that UL38, an HCMV protein that activates mTORC1, is necessary and sufficient to destabilize insulin receptor substrate 1 (IRS1), a model insulin receptor substrate (IRS) protein. Degradation of IRS proteins in settings of excessive mTORC1 activity is an important mechanism for insulin resistance. When IRS proteins are destabilized, PI3K cannot be recruited to growth factor receptor complexes, and hence, AKT membrane recruitment, a rate limiting step in its activation, fails to occur. Despite its penchant for remodeling host cell signaling pathways, our results reveal that HCMV relies upon a cell-intrinsic negative regulatory feedback loop to inactivate AKT. Given that pharmacological inhibition of PI3K/AKT potently induces HCMV reactivation from latency, our findings also imply that the expression of UL38 activity must be tightly regulated within latently infected cells to avoid spontaneous reactivation.
Collapse
Affiliation(s)
- Anthony J. Domma
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center Shreveport, Shreveport, Louisiana, USA
| | - Lauren A. Henderson
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center Shreveport, Shreveport, Louisiana, USA
| | - Felicia D. Goodrum
- Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
- Bio5 Institute, University of Arizona, Tucson, Arizona, USA
| | - Nathaniel J. Moorman
- Department of Microbiology and Immunology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Jeremy P. Kamil
- Department of Microbiology and Immunology, Louisiana State University Health Sciences Center Shreveport, Shreveport, Louisiana, USA
| |
Collapse
|
7
|
Leroux AE, Biondi RM. The choreography of protein kinase PDK1 and its diverse substrate dance partners. Biochem J 2023; 480:1503-1532. [PMID: 37792325 DOI: 10.1042/bcj20220396] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/24/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023]
Abstract
The protein kinase PDK1 phosphorylates at least 24 distinct substrates, all of which belong to the AGC protein kinase group. Some substrates, such as conventional PKCs, undergo phosphorylation by PDK1 during their synthesis and subsequently get activated by DAG and Calcium. On the other hand, other substrates, including members of the Akt/PKB, S6K, SGK, and RSK families, undergo phosphorylation and activation downstream of PI3-kinase signaling. This review presents two accepted molecular mechanisms that determine the precise and timely phosphorylation of different substrates by PDK1. The first mechanism involves the colocalization of PDK1 with Akt/PKB in the presence of PIP3. The second mechanism involves the regulated docking interaction between the hydrophobic motif (HM) of substrates and the PIF-pocket of PDK1. This interaction, in trans, is equivalent to the molecular mechanism that governs the activity of AGC kinases through their HMs intramolecularly. PDK1 has been instrumental in illustrating the bi-directional allosteric communication between the PIF-pocket and the ATP-binding site and the potential of the system for drug discovery. PDK1's interaction with substrates is not solely regulated by the substrates themselves. Recent research indicates that full-length PDK1 can adopt various conformations based on the positioning of the PH domain relative to the catalytic domain. These distinct conformations of full-length PDK1 can influence the interaction and phosphorylation of substrates. Finally, we critically discuss recent findings proposing that PIP3 can directly regulate the activity of PDK1, which contradicts extensive in vitro and in vivo studies conducted over the years.
Collapse
Affiliation(s)
- Alejandro E Leroux
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society, Buenos Aires C1425FQD, Argentina
| | - Ricardo M Biondi
- Instituto de Investigación en Biomedicina de Buenos Aires (IBioBA) - CONICET - Partner Institute of the Max Planck Society, Buenos Aires C1425FQD, Argentina
| |
Collapse
|
8
|
Rose MM, Nassar KW, Sharma V, Schweppe RE. AKT-independent signaling in PIK3CA-mutant thyroid cancer mediates resistance to dual SRC and MEK1/2 inhibition. Med Oncol 2023; 40:299. [PMID: 37713162 DOI: 10.1007/s12032-023-02118-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 07/08/2023] [Indexed: 09/16/2023]
Abstract
Anaplastic thyroid cancer (ATC) is a rare and aggressive disease with 90% of patients succumbing to this disease 1 year after diagnosis. The approval of the combination therapy of a BRAF inhibitor dabrafenib with the MEK1/2 inhibitor trametinib has improved the overall survival of ATC patients. However, resistance to therapy remains a major problem. We have previously demonstrated combined inhibition of Src with dasatinib and MEK1/2 with trametinib synergistically inhibits growth and induces apoptosis in BRAF- and RAS-mutant thyroid cancer cells, however PIK3CA-mutant cells exhibit a mixed response. Herein, we determined that AKT is not a major mediator of sensitivity and instead PIK3CA-mutants that are resistant to combined dasatinib and trametinib have sustained activation of PDK1 signaling. Furthermore, combined inhibition of PDK1 and MEK1/2 was sufficient to reduce cell viability. These data indicate PDK1 inhibition is a therapeutic option for PIK3CA mutations that do not respond to combined Src and MEK1/2 inhibition.
Collapse
Affiliation(s)
- Madison M Rose
- Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Mail Stop 8106, Aurora, CO, 80045, USA.
| | - Kelsey W Nassar
- Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Mail Stop 8106, Aurora, CO, 80045, USA
| | - Vibha Sharma
- Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Mail Stop 8106, Aurora, CO, 80045, USA
| | - Rebecca E Schweppe
- Division of Endocrinology, Metabolism, and Diabetes, School of Medicine, University of Colorado Anschutz Medical Campus, Mail Stop 8106, Aurora, CO, 80045, USA
| |
Collapse
|
9
|
Domma AJ, Goodrum FD, Moorman NJ, Kamil JP. Human cytomegalovirus attenuates AKT activity by destabilizing insulin receptor substrate proteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.17.537203. [PMID: 37131605 PMCID: PMC10153195 DOI: 10.1101/2023.04.17.537203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The phosphoinositide 3-kinase (PI3K)/AKT pathway plays crucial roles in cell viability and protein synthesis and is frequently co-opted by viruses to support their replication. Although many viruses maintain high levels of AKT activity during infection, other viruses, such as vesicular stomatitis virus and human cytomegalovirus (HCMV), cause AKT to accumulate in an inactive state. To efficiently replicate, HCMV requires FoxO transcription factors to localize to the infected cell nucleus (Zhang et. al. mBio 2022), a process directly antagonized by AKT. Therefore, we sought to investigate how HCMV inactivates AKT to achieve this. Subcellular fractionation and live cell imaging studies indicated that AKT failed to recruit to membranes upon serum-stimulation of infected cells. However, UV-inactivated virions were unable to render AKT non-responsive to serum, indicating a requirement for de novo viral gene expression. Interestingly, we were able to identify that UL38 (pUL38), a viral activator of mTORC1, is required to diminish AKT responsiveness to serum. mTORC1 contributes to insulin resistance by causing proteasomal degradation of insulin receptor substrate (IRS) proteins, such as IRS1, which are necessary for the recruitment of PI3K to growth factor receptors. In cells infected with a recombinant HCMV disrupted for UL38 , AKT responsiveness to serum is retained and IRS1 is not degraded. Furthermore, ectopic expression of UL38 in uninfected cells induces IRS1 degradation, inactivating AKT. These effects of UL38 were reversed by the mTORC1 inhibitor, rapamycin. Collectively, our results demonstrate that HCMV relies upon a cell-intrinsic negative feedback loop to render AKT inactive during productive infection.
Collapse
Affiliation(s)
- Anthony J. Domma
- Department of Microbiology and Immunology, LSU Health Sciences Center Shreveport, Shreveport Louisiana, USA
| | - Felicia D. Goodrum
- Department of Immunobiology, University of Arizona, Tucson, AZ, USA
- Bio5 Institute, University of Arizona, Tucson, AZ, USA
| | - Nathaniel J. Moorman
- Department of Microbiology and Immunology, UNC Chapel Hill, Chapel Hill, NC, USA
| | - Jeremy P. Kamil
- Department of Microbiology and Immunology, LSU Health Sciences Center Shreveport, Shreveport Louisiana, USA
| |
Collapse
|
10
|
Yang CC, Masai H. Claspin is Required for Growth Recovery from Serum Starvation through Regulating the PI3K-PDK1-mTOR Pathway in Mammalian Cells. Mol Cell Biol 2023; 43:1-21. [PMID: 36720467 PMCID: PMC9936878 DOI: 10.1080/10985549.2022.2160598] [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] [Indexed: 02/01/2023] Open
Abstract
Claspin plays multiple important roles in regulation of DNA replication as a mediator for the cellular response to replication stress, an integral replication fork factor that facilitates replication fork progression and a factor that promotes initiation by recruiting Cdc7 kinase. Here, we report a novel role of Claspin in growth recovery from serum starvation, which requires the activation of PI3 kinase (PI3K)-PDK1-Akt-mTOR pathways. In the absence of Claspin, cells do not proceed into S phase and eventually die partially in a ROS- and p53-dependent manner. Claspin directly interacts with PI3K and mTOR, and is required for activation of PI3K-PDK1-mTOR and for that of mTOR downstream factors, p70S6K and 4EBP1, but not for p38 MAPK cascade during the recovery from serum starvation. PDK1 physically interacts with Claspin, notably with CKBD, in a manner dependent on phosphorylation of the latter protein, and is required for interaction of mTOR with Claspin. Thus, Claspin plays a novel role as a key regulator for nutrition-induced proliferation/survival signaling by activating the mTOR pathway. The results also suggest a possibility that Claspin may serve as a common mediator that receives signals from different PI3K-related kinases and transmit them to specific downstream kinases.
Collapse
Affiliation(s)
- Chi-Chun Yang
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| | - Hisao Masai
- Department of Basic Medical Sciences, Tokyo Metropolitan Institute of Medical Science, Tokyo, Japan
| |
Collapse
|
11
|
Thorner J. TOR complex 2 is a master regulator of plasma membrane homeostasis. Biochem J 2022; 479:1917-1940. [PMID: 36149412 PMCID: PMC9555796 DOI: 10.1042/bcj20220388] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
As first demonstrated in budding yeast (Saccharomyces cerevisiae), all eukaryotic cells contain two, distinct multi-component protein kinase complexes that each harbor the TOR (Target Of Rapamycin) polypeptide as the catalytic subunit. These ensembles, dubbed TORC1 and TORC2, function as universal, centrally important sensors, integrators, and controllers of eukaryotic cell growth and homeostasis. TORC1, activated on the cytosolic surface of the lysosome (or, in yeast, on the cytosolic surface of the vacuole), has emerged as a primary nutrient sensor that promotes cellular biosynthesis and suppresses autophagy. TORC2, located primarily at the plasma membrane, plays a major role in maintaining the proper levels and bilayer distribution of all plasma membrane components (sphingolipids, glycerophospholipids, sterols, and integral membrane proteins). This article surveys what we have learned about signaling via the TORC2 complex, largely through studies conducted in S. cerevisiae. In this yeast, conditions that challenge plasma membrane integrity can, depending on the nature of the stress, stimulate or inhibit TORC2, resulting in, respectively, up-regulation or down-regulation of the phosphorylation and thus the activity of its essential downstream effector the AGC family protein kinase Ypk1. Through the ensuing effect on the efficiency with which Ypk1 phosphorylates multiple substrates that control diverse processes, membrane homeostasis is maintained. Thus, the major focus here is on TORC2, Ypk1, and the multifarious targets of Ypk1 and how the functions of these substrates are regulated by their Ypk1-mediated phosphorylation, with emphasis on recent advances in our understanding of these processes.
Collapse
Affiliation(s)
- Jeremy Thorner
- Division of Biochemistry, Biophysics and Structural Biology, Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720-3202, U.S.A
| |
Collapse
|
12
|
Lin H, Wang X, Li Z, Huang M, Feng J, Chen H, Gao J, Feng Y, Wu J, Tang S, Zhou R, Ren Y, Huang F, Jiang Z. Total flavonoids of Rhizoma drynariae promote angiogenesis and osteogenesis in bone defects. Phytother Res 2022; 36:3584-3600. [PMID: 35960140 DOI: 10.1002/ptr.7525] [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: 08/09/2021] [Revised: 05/22/2022] [Accepted: 05/30/2022] [Indexed: 11/09/2022]
Abstract
Bone defects are difficult to heal, which conveys a heavy burden to patients' lives and their economy. The total flavonoids of Rhizoma drynariae (TFRD) can promote the osteogenesis of distraction osteogenesis. However, the dose effect is not clear, the treatment period is short, and the quality of bone formation is poor. In our study, we observed the long-term effects and dose effects of TFRD on bone defects, verified the main ingredients of TFRD in combination with network pharmacology for the first time, explored its potential mechanism, and verified these findings. We found that TFRD management for 12 weeks regulated osteogenesis and angiogenesis in rats with 4-mm tibial bone defects through the PI3K/AKT/HIF-1α/VEGF signaling pathway, especially at high doses (135 mg kg-1 d-1 ). The vascularization effect of TFRD in promoting human umbilical vein endothelial cells was inhibited by PI3K inhibitors. These results provide a reference for the clinical application of TFRD.
Collapse
Affiliation(s)
- Haixiong Lin
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Orthopaedics, Ningxia Hui Autonomous Region Hospital and Research Institute of Traditional Chinese Medicine, Yinchuan, China.,Institute for Tissue Engineering and Regenerative Medicine, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiaotong Wang
- School of Acupuncture-Moxibustion and Tuina, Beijing University of Chinese Medicine, Beijing, China
| | - Zige Li
- The 2nd Department of Arthrosis, Wangjing Hospital of China Academy of Chinese Medical Sciences, Beiijing, China
| | - Minling Huang
- Department of Diabetes, Central Clinical School, Monash University, Melbourne, Australia
| | - Junjie Feng
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Huamei Chen
- Knee Surgery, The Fifth People's Hospital of Nanhai District, Foshan, China
| | - Junyan Gao
- Department of Orthopaedics & Traumatology, Shantou Hospital of Traditional Chinese Medicine, Shantou, China
| | - Yuanlan Feng
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Jingjing Wu
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Shengyao Tang
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ruoyu Zhou
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yueyi Ren
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Feng Huang
- The First School of Clinical Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China.,Department of Orthopaedics & Traumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ziwei Jiang
- Department of Orthopaedics & Traumatology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| |
Collapse
|
13
|
Garcia-Viloca M, Bayascas JR, Lluch JM, González-Lafont À. Molecular Insights into the Regulation of 3-Phosphoinositide-Dependent Protein Kinase 1: Modeling the Interaction between the Kinase and the Pleckstrin Homology Domains. ACS OMEGA 2022; 7:25186-25199. [PMID: 35910176 PMCID: PMC9330272 DOI: 10.1021/acsomega.2c02020] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The 3-phosphoinositide-dependent protein kinase 1 (PDK1) K465E mutant kinase can still activate protein kinase B (PKB) at the membrane in a phosphatidylinositol-3,4,5-trisphosphate (PIP3, PtdIns(3,4,5)P3) independent manner. To understand this new PDK1 regulatory mechanism, docking and molecular dynamics calculations were performed for the first time to simulate the wild-type kinase domain-pleckstrin homology (PH) domain complex with PH-in and PH-out conformations. These simulations were then compared to the PH-in model of the KD-PH(mutant K465E) PDK1 complex. Additionally, three KD-PH complexes were simulated, including a substrate analogue bound to a hydrophobic pocket (denominated the PIF-pocket) substrate-docking site. We find that only the PH-out conformation, with the PH domain well-oriented to interact with the cellular membrane, is active for wild-type PDK1. In contrast, the active conformation of the PDK1 K465E mutant is PH-in, being ATP-stable at the active site while the PIF-pocket is more accessible to the peptide substrate. We corroborate that both the docking-site binding and the catalytic activity are in fact enhanced in knock-in mouse samples expressing the PDK1 K465E protein, enabling the phosphorylation of PKB in the absence of PIP3 binding.
Collapse
Affiliation(s)
- Mireia Garcia-Viloca
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Jose Ramón Bayascas
- Institut
de Neurociències, Universitat Autònoma
de Barcelona, Bellaterra, Barcelona 08193, Spain
- Department
of Biochemistry and Molecular Biology, Biochemistry Unit of the School
of Medicine, Universitat Autònoma
de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - José M. Lluch
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institut
de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| | - Àngels González-Lafont
- Departament
de Química, Universitat Autònoma
de Barcelona, Bellaterra, Barcelona 08193, Spain
- Institut
de Biotecnologia i de Biomedicina (IBB), Universitat Autònoma de Barcelona, Bellaterra, Barcelona 08193, Spain
| |
Collapse
|
14
|
Cai W, Nguyen MQ, Wilski NA, Purwin TJ, Vernon M, Tiago M, Aplin AE. A Genome-Wide Screen Identifies PDPK1 as a Target to Enhance the Efficacy of MEK1/2 Inhibitors in NRAS Mutant Melanoma. Cancer Res 2022; 82:2625-2639. [PMID: 35657206 PMCID: PMC9298960 DOI: 10.1158/0008-5472.can-21-3217] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 04/22/2022] [Accepted: 05/31/2022] [Indexed: 01/21/2023]
Abstract
Melanomas frequently harbor activating NRAS mutations. However, limited advance has been made in developing targeted therapy options for patients with NRAS mutant melanoma. MEK inhibitors (MEKi) show modest efficacy in the clinic and their actions need to be optimized. In this study, we performed a genome-wide CRISPR-Cas9-based screen and demonstrated that loss of phosphoinositide-dependent kinase-1 (PDPK1) enhances the efficacy of MEKi. The synergistic effects of PDPK1 loss and MEKi was validated in NRAS mutant melanoma cell lines using pharmacologic and molecular approaches. Combined PDPK1 inhibitors (PDPK1i) with MEKi suppressed NRAS mutant xenograft growth and induced gasdermin E-associated pyroptosis. In an immune-competent allograft model, PDPK1i+MEKi increased the ratio of intratumoral CD8+ T cells, delayed tumor growth, and prolonged survival; the combination treatment was less effective against tumors in immune-deficient mice. These data suggest PDPK1i+MEKi as an efficient immunostimulatory strategy against NRAS mutant melanoma. SIGNIFICANCE Targeting PDPK1 stimulates antitumor immunity and sensitizes NRAS mutant melanoma to MEK inhibition, providing rationale for the clinical development of a combinatorial approach for treating patients with melanoma.
Collapse
Affiliation(s)
- Weijia Cai
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Mai Q. Nguyen
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Nicole A. Wilski
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Timothy J. Purwin
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Megane Vernon
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Manoela Tiago
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
| | - Andrew E. Aplin
- Department of Cancer Biology, Thomas Jefferson University, Philadelphia, PA 19107
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA 19107
| |
Collapse
|
15
|
mTOR substrate phosphorylation in growth control. Cell 2022; 185:1814-1836. [PMID: 35580586 DOI: 10.1016/j.cell.2022.04.013] [Citation(s) in RCA: 145] [Impact Index Per Article: 72.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 04/05/2022] [Accepted: 04/07/2022] [Indexed: 12/20/2022]
Abstract
The target of rapamycin (TOR), discovered 30 years ago, is a highly conserved serine/threonine protein kinase that plays a central role in regulating cell growth and metabolism. It is activated by nutrients, growth factors, and cellular energy. TOR forms two structurally and functionally distinct complexes, TORC1 and TORC2. TOR signaling activates cell growth, defined as an increase in biomass, by stimulating anabolic metabolism while inhibiting catabolic processes. With emphasis on mammalian TOR (mTOR), we comprehensively reviewed the literature and identified all reported direct substrates. In the context of recent structural information, we discuss how mTORC1 and mTORC2, despite having a common catalytic subunit, phosphorylate distinct substrates. We conclude that the two complexes recruit different substrates to phosphorylate a common, minimal motif.
Collapse
|
16
|
Abstract
Mitogen-activated protein kinase (MAPK)-activated protein kinases (MAPKAPKs) are defined by their exclusive activation by MAPKs. They can be activated by classical and atypical MAPKs that have been stimulated by mitogens and various stresses. Genetic deletions of MAPKAPKs and availability of highly specific small-molecule inhibitors have continuously increased our functional understanding of these kinases. MAPKAPKs cooperate in the regulation of gene expression at the level of transcription; RNA processing, export, and stability; and protein synthesis. The diversity of stimuli for MAPK activation, the cross talk between the different MAPKs and MAPKAPKs, and the specific substrate pattern of MAPKAPKs orchestrate immediate-early and inflammatory responses in space and time and ensure proper control of cell growth, differentiation, and cell behavior. Hence, MAPKAPKs are promising targets for cancer therapy and treatments for conditions of acute and chronic inflammation, such as cytokine storms and rheumatoid arthritis. Expected final online publication date for the Annual Review of Biochemistry, Volume 91 is June 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
Collapse
Affiliation(s)
- Natalia Ronkina
- Institute of Cell Biochemistry, Hannover Medical School, Hannover, Germany;
| | - Matthias Gaestel
- Institute of Cell Biochemistry, Hannover Medical School, Hannover, Germany;
| |
Collapse
|
17
|
CircRNA ANXA2 Promotes Lung Cancer Proliferation and Metastasis by Upregulating PDPK1 Expression. JOURNAL OF ONCOLOGY 2022; 2021:4526609. [PMID: 34992655 PMCID: PMC8727169 DOI: 10.1155/2021/4526609] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/18/2021] [Accepted: 12/03/2021] [Indexed: 12/25/2022]
Abstract
Lung cancer is a common malignant tumor that seriously threatens human health. It has become the top malignant tumor in terms of morbidity and mortality. In recent years, circRNA, a special noncoding RNA molecule, has attracted considerable interest. This study focused on the role of circRNA ANXA2 (circANXA2) in lung cancer and the molecular mechanism of cancer promotion. Real-time quantitative PCR (RT-PCR) was used in detecting the expression abundance of circANXA2 in different lung cancer cells and tissues. The subcellular localization of circANXA2 was detected through fluorescence in situ hybridization. circANXA2 expression was knocked down through siRNA. CCK-8, clone formation assay, and TUNEL assay were used in evaluating the effects of circANXA2 on cell proliferation, clone formation ability, and apoptosis. The role of circANXA2 in tumor proliferation was further verified in vivo using the tumor transplantation model in nude mice. The molecular mechanism of circANXA2 was investigated with luciferase activity assay and RT-PCR. The expression abundance of circANXA2 is high in lung cancer cell lines and tissues. Knocking down of circANXA2 inhibits the proliferation and clonogenesis of the lung cancer cells. Knocking down circANXA2 promotes apoptosis. circANXA2 further affects downstream PDPK1 expression by regulating miR-33a-5p and thereby affecting the malignancy of the lung cancer cells. circANXA2 inhibits miR-33a-5p activity by directly interacting with miR-33a-5p. circANXA2 regulates the transcription of the miR-33a-5p downstream target gene PDPK1 and affects the malignant progression of lung cancer.
Collapse
|
18
|
Pfeiffer S, Tomašcová A, Mamrak U, Haunsberger SJ, Connolly NMC, Resler A, Düssmann H, Weisová P, Jirström E, D'Orsi B, Chen G, Cremona M, Hennessy BT, Plesnila N, Prehn JHM. AMPK-regulated miRNA-210-3p is activated during ischaemic neuronal injury and modulates PI3K-p70S6K signalling. J Neurochem 2021; 159:710-728. [PMID: 33694332 DOI: 10.1111/jnc.15347] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 02/12/2021] [Accepted: 03/05/2021] [Indexed: 12/14/2022]
Abstract
Progressive neuronal injury following ischaemic stroke is associated with glutamate-induced depolarization, energetic stress and activation of AMP-activated protein kinase (AMPK). We here identify a molecular signature associated with neuronal AMPK activation, as a critical regulator of cellular response to energetic stress following ischaemia. We report a robust induction of microRNA miR-210-3p both in vitro in primary cortical neurons in response to acute AMPK activation and following ischaemic stroke in vivo. Bioinformatics and reverse phase protein array analysis of neuronal protein expression changes in vivo following administration of a miR-210-3p mimic revealed altered expression of phosphatase and tensin homolog (PTEN), 3-phosphoinositide-dependent protein kinase 1 (PDK1), ribosomal protein S6 kinase (p70S6K) and ribosomal protein S6 (RPS6) signalling in response to increasing miR-210-3p. In vivo, we observed a corresponding reduction in p70S6K activity following ischaemic stroke. Utilizing models of glutamate receptor over-activation in primary neurons, we demonstrated that induction of miR-210-3p was accompanied by sustained suppression of p70S6K activity and that this effect was reversed by miR-210-3p inhibition. Collectively, these results provide new molecular insight into the regulation of cell signalling during ischaemic injury, and suggest a novel mechanism whereby AMPK regulates miR-210-3p to control p70S6K activity in ischaemic stroke and excitotoxic injury.
Collapse
Affiliation(s)
- Shona Pfeiffer
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Anna Tomašcová
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Biomedical Centre Martin, Comenius University in Bratislava, Bratislava, Slovakia
| | - Uta Mamrak
- Institute for Stroke and Dementia Research (ISD), Munich, Germany
| | - Stefan J Haunsberger
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Niamh M C Connolly
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Alexa Resler
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Heiko Düssmann
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Petronela Weisová
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Elisabeth Jirström
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- FutureNeuro SFI Research Center, Royal College of Surgeons Ireland, Dublin, Ireland
| | - Beatrice D'Orsi
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Institute of Neuroscience, Italian National Research Council (CNR), Pisa, Italy
| | - Gang Chen
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Mattia Cremona
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Dept of Molecular Medicine (Medical Oncology group), Royal College of Surgeons in Ireland, Dublin, Ireland
| | - Bryan T Hennessy
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- Dept of Molecular Medicine (Medical Oncology group), Royal College of Surgeons in Ireland, Dublin, Ireland
- Department of Medical Oncology, Beaumont Hospital, Dublin, Ireland
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research (ISD), Munich, Germany
- Munich Cluster of Systems Neurology (Synergy), Munich, Germany
| | - Jochen H M Prehn
- Department of Physiology and Medical Physics, Royal College of Surgeons in Ireland, Dublin, Ireland
- Centre for Systems Medicine, Royal College of Surgeons in Ireland, Dublin, Ireland
- FutureNeuro SFI Research Center, Royal College of Surgeons Ireland, Dublin, Ireland
| |
Collapse
|
19
|
Wegner MS, Schömel N, Olzomer EM, Trautmann S, Olesch C, Byrne FL, Brüne B, Gurke R, Ferreirós N, Weigert A, Geisslinger G, Hoehn KL. Increased glucosylceramide production leads to decreased cell energy metabolism and lowered tumor marker expression in non-cancerous liver cells. Cell Mol Life Sci 2021; 78:7025-7041. [PMID: 34626204 PMCID: PMC8558193 DOI: 10.1007/s00018-021-03958-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 09/15/2021] [Accepted: 09/29/2021] [Indexed: 12/11/2022]
Abstract
Hepatocellular carcinoma (HCC) is one of the most difficult cancer types to treat. Liver cancer is often diagnosed at late stages and therapeutic treatment is frequently accompanied by development of multidrug resistance. This leads to poor outcomes for cancer patients. Understanding the fundamental molecular mechanisms leading to liver cancer development is crucial for developing new therapeutic approaches, which are more efficient in treating cancer. Mice with a liver specific UDP-glucose ceramide glucosyltransferase (UGCG) knockout (KO) show delayed diethylnitrosamine (DEN)-induced liver tumor growth. Accordingly, the rationale for our study was to determine whether UGCG overexpression is sufficient to drive cancer phenotypes in liver cells. We investigated the effect of UGCG overexpression (OE) on normal murine liver (NMuLi) cells. Increased UGCG expression results in decreased mitochondrial respiration and glycolysis, which is reversible by treatment with EtDO-P4, an UGCG inhibitor. Furthermore, tumor markers such as FGF21 and EPCAM are lowered following UGCG OE, which could be related to glucosylceramide (GlcCer) and lactosylceramide (LacCer) accumulation in glycosphingolipid-enriched microdomains (GEMs) and subsequently altered signaling protein phosphorylation. These cellular processes lead to decreased proliferation in NMuLi/UGCG OE cells. Our data show that increased UGCG expression itself does not induce pro-cancerous processes in normal liver cells, which indicates that increased GlcCer expression leads to different outcomes in different cancer types.
Collapse
Affiliation(s)
- Marthe-Susanna Wegner
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany. .,School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia.
| | - Nina Schömel
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Ellen M Olzomer
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Sandra Trautmann
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Catherine Olesch
- Faculty of Medicine, Institute of Biochemistry I, Johann Wolfgang Goethe University, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Frances L Byrne
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| | - Bernhard Brüne
- Faculty of Medicine, Institute of Biochemistry I, Johann Wolfgang Goethe University, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Robert Gurke
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany.,Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Nerea Ferreirós
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Andreas Weigert
- Faculty of Medicine, Institute of Biochemistry I, Johann Wolfgang Goethe University, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Gerd Geisslinger
- Pharmazentrum Frankfurt/ZAFES, Institute of Clinical Pharmacology, Johann Wolfgang Goethe University, House 74, Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany.,Fraunhofer Institute for Translational Medicine and Pharmacology (ITMP), Theodor Stern-Kai 7, 60590, Frankfurt am Main, Germany
| | - Kyle L Hoehn
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW, 2052, Australia
| |
Collapse
|
20
|
McKenna M, Balasuriya N, Zhong S, Li SSC, O'Donoghue P. Phospho-Form Specific Substrates of Protein Kinase B (AKT1). Front Bioeng Biotechnol 2021; 8:619252. [PMID: 33614606 PMCID: PMC7886700 DOI: 10.3389/fbioe.2020.619252] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/29/2020] [Indexed: 11/17/2022] Open
Abstract
Protein kinase B (AKT1) is hyper-activated in diverse human tumors. AKT1 is activated by phosphorylation at two key regulatory sites, Thr308 and Ser473. Active AKT1 phosphorylates many, perhaps hundreds, of downstream cellular targets in the cytosol and nucleus. AKT1 is well-known for phosphorylating proteins that regulate cell survival and apoptosis, however, the full catalog of AKT1 substrates remains unknown. Using peptide arrays, we recently discovered that each phosphorylated form of AKT1 (pAKT1S473, pAKT1T308, and ppAKT1S473,T308) has a distinct substrate specificity, and these data were used to predict potential new AKT1 substrates. To test the high-confidence predictions, we synthesized target peptides representing putative AKT1 substrates. Peptides substrates were synthesized by solid phase synthesis and their purity was confirmed by mass spectrometry. Most of the predicted peptides showed phosphate accepting activity similar to or greater than that observed with a peptide derived from a well-established AKT1 substrate, glycogen synthase kinase 3β (GSK-3β). Among the novel substrates, AKT1 was most active with peptides representing PIP3-binding protein Rab11 family-interacting protein 2 and cysteinyl leukotriene receptor 1, indicating their potential role in AKT1-dependent cellular signaling. The ppAKT1S473,T308 enzyme was highly selective for peptides containing a patch of basic residues at −5, −4, −3 and aromatic residues (Phe/Tyr) at +1 positions from the phosphorylation site. The pAKT1S473 variant preferred more acidic peptides, Ser or Pro at +4, and was agnostic to the residue at −5. The data further support our hypothesis that Ser473 phosphorylation plays a key role in modulating AKT1 substrate selectivity.
Collapse
Affiliation(s)
- McShane McKenna
- Department of Biochemistry, The University of Western Ontario, London, ON, Canada
| | - Nileeka Balasuriya
- Department of Biochemistry, The University of Western Ontario, London, ON, Canada
| | - Shanshan Zhong
- Department of Biochemistry, The University of Western Ontario, London, ON, Canada
| | - Shawn Shun-Cheng Li
- Department of Biochemistry, The University of Western Ontario, London, ON, Canada
| | - Patrick O'Donoghue
- Department of Biochemistry, The University of Western Ontario, London, ON, Canada.,Department of Chemistry, The University of Western Ontario, London, ON, Canada
| |
Collapse
|
21
|
Signaling Pathway Mediating Myeloma Cell Growth and Survival. Cancers (Basel) 2021; 13:cancers13020216. [PMID: 33435632 PMCID: PMC7827005 DOI: 10.3390/cancers13020216] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 12/21/2022] Open
Abstract
Simple Summary The bone marrow (BM) microenvironment plays a crucial role in pathogenesis of multiple myeloma (MM), and delineation of the intracellular signaling pathways activated in the BM microenvironment in MM cells is essential to develop novel therapeutic strategies to improve patient outcome. Abstract The multiple myeloma (MM) bone marrow (BM) microenvironment consists of different types of accessory cells. Both soluble factors (i.e., cytokines) secreted from these cells and adhesion of MM cells to these cells play crucial roles in activation of intracellular signaling pathways mediating MM cell growth, survival, migration, and drug resistance. Importantly, there is crosstalk between the signaling pathways, increasing the complexity of signal transduction networks in MM cells in the BM microenvironment, highlighting the requirement for combination treatment strategies to blocking multiple signaling pathways.
Collapse
|
22
|
Bai Y, Zhang Q, Chen Q, Zhou Q, Zhang Y, Shi Z, Nong H, Liu M, Zeng G, Zong S. Conditional knockout of the PDK-1 gene in osteoblasts affects osteoblast differentiation and bone formation. J Cell Physiol 2020; 236:5432-5445. [PMID: 33377210 DOI: 10.1002/jcp.30249] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 12/22/2022]
Abstract
Osteoblasts are the main functional cells of bone formation, and they are responsible for the synthesis, secretion, and mineralization of the bone matrix. Phosphatidylinositol-3-kinase/Akt is an important signaling pathway involved in the regulation of cell proliferation, death, and survival. Some studies have shown that 3-phosphoinositide-dependent protein kinase-1 (PDK-1) plays an important role in the phosphorylation of Akt. In the present study, an osteocalcin (OCN) promoter-driven Cre-LoxP system was established to specifically delete the PDK-1 gene in osteoblasts. It was found that the size and weight of PDK-1 conditional gene knockout (cKO) mice were significantly reduced. von Kossa staining and microcomputed tomography showed that the trabecular thickness, trabecular number, and bone volume were significantly decreased, whereas trabecular separation was increased, as compared with wide-type littermates, which were characterized by a decreased bone mass. A model of distal femoral defect was established, and it was found that cKO mice delayed bone defect repair. In osteoblasts derived from PDK-1 cKO mice, the alkaline phosphatase (ALP) secretion and ability of calcium mineralization were significantly decreased, and the expressions of osteoblast-related proteins, runt-related transcription factor 2, OCN, and ALP were also clearly decreased. Moreover, the phosphorylation level of Akt and downstream factor GSK3β and their response to insulin-like growth factor-1 (IGF-1) decreased clearly. Therefore, we believe that PDK-1 plays a very important role in osteoblast differentiation and bone formation by regulating the PDK-1/Akt/GSK3β signaling pathway.
Collapse
Affiliation(s)
- Yiguang Bai
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Department of Orthopaedics, Nanchong Central Hospital, The Second Clinical Institute of North Sichuan Medical College, Nanchong, Sichuan, China
| | - Qiong Zhang
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi, China
| | - Qiaoling Chen
- Department of Oncology, Nanchong Central Hospital, The Second Clinical Institute of North Sichuan Medical College, Nanchong, Sichuan, China
| | - Quan Zhou
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi, China.,Department of Emergency, The Hongqi Hospital Affiliated to Mudanjiang Medical University, Mudanjiang, Heilongjiang, China
| | - Yanan Zhang
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Zhuohua Shi
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Haibin Nong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Mingfu Liu
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China
| | - Gaofeng Zeng
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi, China
| | - Shaohui Zong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Nanning, Guangxi, China.,Research Centre for Regenerative Medicine and Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
| |
Collapse
|
23
|
Bai Y, Zhang Q, Zhou Q, Zhang Y, Nong H, Liu M, Shi Z, Zeng G, Zong S. Effects of inhibiting PDK‑1 expression in bone marrow mesenchymal stem cells on osteoblast differentiation in vitro. Mol Med Rep 2020; 23:118. [PMID: 33300048 PMCID: PMC7751487 DOI: 10.3892/mmr.2020.11757] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Accepted: 11/02/2020] [Indexed: 01/22/2023] Open
Abstract
Osteoblasts are the main functional cells in bone formation, which are responsible for the synthesis, secretion and mineralization of bone matrix. The PI3K/AKT signaling pathway is strongly associated with the differentiation and survival of osteoblasts. The 3-phosphoinositide-dependent protein kinase-1 (PDK-1) protein is considered the master upstream lipid kinase of the PI3K/AKT cascade. The present study aimed to investigate the role of PDK-1 in the process of mouse osteoblast differentiation in vitro. In the BX-912 group, BX-912, a specific inhibitor of PDK-1, was added to osteoblast induction medium (OBM) to treat bone marrow mesenchymal stem cells (BMSCs), whereas the control group was treated with OBM alone. Homozygote PDK1flox/flox mice were designed and generated, and were used to obtain BMSCsPDK1flox/flox. Subsequently, an adenovirus containing Cre recombinase enzyme (pHBAd-cre-EGFP) was used to disrupt the PDK-1 gene in BMSCsPDK1flox/flox; this served as the pHBAd-cre-EGFP group and the efficiency of the disruption was verified. Western blot analysis demonstrated that the protein expression levels of phosphorylated (p)-PDK1 and p-AKT were gradually increased during the osteoblast differentiation process. Notably, BX-912 treatment and disruption of the PDK-1 gene with pHBAd-cre-EGFP effectively reduced the number of alkaline phosphatase (ALP)-positive cells and the optical density value of ALP activity, as well as the formation of cell mineralization. The mRNA expression levels of PDK-1 in the pHBAd-cre-EGFP group were significantly downregulated compared with those in the empty vector virus group on days 3–7. The mRNA expression levels of the osteoblast-related genes RUNX2, osteocalcin and collagen I were significantly decreased in the BX-912 and pHBAd-cre-EGFP groups on days 7 and 21 compared with those in the control and empty vector virus groups. Overall, the results indicated that BX-912 and disruption of the PDK-1 gene in vitro significantly inhibited the differentiation and maturation of osteoblasts. These experimental results provided an experimental and theoretical basis for the role of PDK-1 in osteoblasts.
Collapse
Affiliation(s)
- Yiguang Bai
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Qiong Zhang
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Quan Zhou
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Yanan Zhang
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Haibin Nong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Mingfu Liu
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Zhuohua Shi
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Gaofeng Zeng
- Department of Nutrition and Food Hygiene, College of Public Hygiene of Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| | - Shaohui Zong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi 530021, P.R. China
| |
Collapse
|
24
|
miR-107 inhibition upregulates CAB39 and activates AMPK-Nrf2 signaling to protect osteoblasts from dexamethasone-induced oxidative injury and cytotoxicity. Aging (Albany NY) 2020; 12:11754-11767. [PMID: 32527986 PMCID: PMC7343481 DOI: 10.18632/aging.103341] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 05/18/2020] [Indexed: 12/15/2022]
Abstract
To human osteoblasts dexamethasone (DEX) treatment induces significant oxidative injury and cytotoxicity. Inhibition of CAB39 (calcium binding protein 39)-targeting microRNA can induce CAB39 upregulation, activating AMP-activated protein kinase (AMPK) signaling and offering osteoblast cytoprotection. Here we identified a novel CAB39-targeting miRNA: the microRNA-107 (miR-107). RNA-Pull down assay results demonstrated that the biotinylated-miR-107 directly binds to CAB39 mRNA in OB-6 human osteoblastic cells. Forced overexpression of miR-107, by infection of pre-miR-107 lentivirus or transfection of wild-type miR-107 mimic, largely inhibited CAB39 expression in OB-6 cells and primary human osteoblasts. Contrarily, miR-107 inhibition, by antagomiR-107, increased its expression, resulting in AMPK cascade activation. AntagomiR-107 largely attenuated DEX-induced cell death and apoptosis in OB-6 cells and human osteoblasts. Importantly, osteoblast cytoprotection by antagomiR-107 was abolished with AMPK in-activation by AMPKα1 dominant negative mutation, silencing or knockout. Further studies demonstrated that antagomiR-107 activated AMPK downstream Nrf2 cascade to inhibit DEX-induced oxidative injury. Conversely, Nrf2 knockout almost abolished antagomiR-107-induced osteoblast cytoprotection against DEX. Collectively, miR-107 inhibition induced CAB39 upregulation and activated AMPK-Nrf2 signaling to protect osteoblasts from DEX-induced oxidative injury and cytotoxicity.
Collapse
|
25
|
Wei Y, Han X, Zhao C. PDK1 regulates the survival of the developing cortical interneurons. Mol Brain 2020; 13:65. [PMID: 32366272 PMCID: PMC7197138 DOI: 10.1186/s13041-020-00604-6] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2019] [Accepted: 04/22/2020] [Indexed: 01/08/2023] Open
Abstract
Inhibitory interneurons are critical for maintaining the excitatory/inhibitory balance. During the development cortical interneurons originate from the ganglionic eminence and arrive at the dorsal cortex through two tangential migration routes. However, the mechanisms underlying the development of cortical interneurons remain unclear. 3-Phosphoinositide-dependent protein kinase-1 (PDK1) has been shown to be involved in a variety of biological processes, including cell proliferation and migration, and plays an important role in the neurogenesis of cortical excitatory neurons. However, the function of PDK1 in interneurons is still unclear. Here, we reported that the disruption of Pdk1 in the subpallium achieved by crossing the Dlx5/6-Cre-IRES-EGFP line with Pdk1fl/fl mice led to the severely increased apoptosis of immature interneurons, subsequently resulting in a remarkable reduction in cortical interneurons. However, the tangential migration, progenitor pools and cell proliferation were not affected by the disruption of Pdk1. We further found the activity of AKT-GSK3β signaling pathway was decreased after Pdk1 deletion, suggesting it might be involved in the regulation of the survival of cortical interneurons. These results provide new insights into the function of PDK1 in the development of the telencephalon.
Collapse
Affiliation(s)
- Yongjie Wei
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Xiaoning Han
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, China
| | - Chunjie Zhao
- Key Laboratory of Developmental Genes and Human Diseases, MOE, School of Medicine, Southeast University, Nanjing, 210009, China.
| |
Collapse
|
26
|
Xiao D, Zhou Q, Gao Y, Cao B, Zhang Q, Zeng G, Zong S. PDK1 is important lipid kinase for RANKL-induced osteoclast formation and function via the regulation of the Akt-GSK3β-NFATc1 signaling cascade. J Cell Biochem 2020; 121:4542-4557. [PMID: 32048762 DOI: 10.1002/jcb.29677] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2019] [Accepted: 01/16/2020] [Indexed: 12/17/2022]
Abstract
Perturbations in the balanced process of osteoblast-mediated bone formation and osteoclast-mediated bone resorption leading to excessive osteoclast formation and/or activity is the cause of many pathological bone conditions such as osteoporosis. The osteoclast is the only cell in the body capable of resorbing and degrading the mineralized bone matrix. Osteoclast formation from monocytic precursors is governed by the actions of two key cytokines macrophage-colony-stimulating factor and receptor activator of nuclear factor-κB ligand (RANKL). Binding of RANKL binding to receptor RANK initiates a series of downstream signaling responses leading to monocytic cell differentiation and fusion, and subsequent mature osteoclast bone resorption and survival. The phosphoinositide-3-kinase (PI3K)-protein kinase B (Akt) signaling cascade is one such pathway activated in response to RANKL. The 3-phosphoinositide-dependent protein kinase 1 (PDK1), is considered the master upstream lipid kinase of the PI3K-Akt cascade. PDK1 functions to phosphorylate and partially activate Akt, triggering the activation of downstream effectors. However, the role of PDK1 in osteoclasts has yet to be clearly defined. In this study, we specifically deleted the PDK1 gene in osteoclasts using the cathepsin-K promoter driven Cre-LoxP system. We found that the specific genetic ablation of PDK1 in osteoclasts leads to an osteoclast-poor osteopetrotic phenotype in mice. In vitro cellular assays further confirmed the impairment of osteoclast formation in response to RANKL by PDK1-deficient bone marrow macrophage (BMM) precursor cells. PDK1-deficient BMMs exhibited reduced ability to reorganize actin cytoskeleton to form a podosomal actin belt as a result of diminished capacity to fuse into giant multinucleated osteoclasts. Notably, biochemical analyses showed that PDK1 deficiency attenuated the phosphorylation of Akt and downstream effector GSK3β, and reduced induction of NFATc1. GSK3β is a reported negative regulator of NFATc1. GSK3β activity is inhibited by Akt-dependent phosphorylation. Thus, our data provide clear genetic and mechanistic insights into the important role for PDK1 in osteoclasts.
Collapse
Affiliation(s)
- Dongliang Xiao
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi, China
| | - Quan Zhou
- Collaborative Innovation Center of Guangxi Biological Medicine, Guangxi Medical University, Nanning, Guangxi, China
| | - Yunbing Gao
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi, China
| | - Baichuan Cao
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi, China
| | - Qiong Zhang
- College of Public Hygiene of Guangxi Medical University, Guangxi, China
| | - Gaofeng Zeng
- College of Public Hygiene of Guangxi Medical University, Guangxi, China
| | - Shaohui Zong
- Department of Spine Osteopathia, The First Affiliated Hospital of Guangxi Medical University, Guangxi Medical University, Nanning, Guangxi, China.,Research Centre for Regenerative Medicine and Guangxi Key Laboratory of Regenerative Medicine, Guangxi Medical University, Nanning, Guangxi, China
| |
Collapse
|
27
|
Ma G, Gezer D, Herrmann O, Feldberg K, Schemionek M, Jawhar M, Reiter A, Brümmendorf TH, Koschmieder S, Chatain N. LCP1 triggers mTORC2/AKT activity and is pharmacologically targeted by enzastaurin in hypereosinophilia. Mol Carcinog 2019; 59:87-103. [DOI: 10.1002/mc.23131] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/14/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022]
Affiliation(s)
- Guangxin Ma
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
- Hematology and Oncology Unit, Department of Geriatrics Qilu Hospital of Shandong University Jinan Shandong China
| | - Deniz Gezer
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Oliver Herrmann
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Kristina Feldberg
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Mirle Schemionek
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Mohamad Jawhar
- Department of Hematology and Oncology University Medical Centre Mannheim, Heidelberg University Mannheim Germany
| | - Andreas Reiter
- Department of Hematology and Oncology University Medical Centre Mannheim, Heidelberg University Mannheim Germany
| | - Tim H. Brümmendorf
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Steffen Koschmieder
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| | - Nicolas Chatain
- Department of Hematology, Oncology, Hemostaseology, and Stem Cell Transplantation, Faculty of Medicine RWTH Aachen University Aachen Germany
| |
Collapse
|
28
|
Dynamic lineage priming is driven via direct enhancer regulation by ERK. Nature 2019; 575:355-360. [PMID: 31695196 DOI: 10.1038/s41586-019-1732-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 10/03/2019] [Indexed: 11/08/2022]
Abstract
Central to understanding cellular behaviour in multi-cellular organisms is the question of how a cell exits one transcriptional state to adopt and eventually become committed to another. Fibroblast growth factor-extracellular signal-regulated kinase (FGF -ERK) signalling drives differentiation of mouse embryonic stem cells (ES cells) and pre-implantation embryos towards primitive endoderm, and inhibiting ERK supports ES cell self-renewal1. Paracrine FGF-ERK signalling induces heterogeneity, whereby cells reversibly progress from pluripotency towards primitive endoderm while retaining their capacity to re-enter self-renewal2. Here we find that ERK reversibly regulates transcription in ES cells by directly affecting enhancer activity without requiring a change in transcription factor binding. ERK triggers the reversible association and disassociation of RNA polymerase II and associated co-factors from genes and enhancers with the mediator component MED24 having an essential role in ERK-dependent transcriptional regulation. Though the binding of mediator components responds directly to signalling, the persistent binding of pluripotency factors to both induced and repressed genes marks them for activation and/or reactivation in response to fluctuations in ERK activity. Among the repressed genes are several core components of the pluripotency network that act to drive their own expression and maintain the ES cell state; if their binding is lost, the ability to reactivate transcription is compromised. Thus, as long as transcription factor occupancy is maintained, so is plasticity, enabling cells to distinguish between transient and sustained signals. If ERK signalling persists, pluripotency transcription factor levels are reduced by protein turnover and irreversible gene silencing and commitment can occur.
Collapse
|
29
|
Akizuki R, Eguchi H, Endo S, Matsunaga T, Ikari A. ZO-2 Suppresses Cell Migration Mediated by a Reduction in Matrix Metalloproteinase 2 in Claudin-18-Expressing Lung Adenocarcinoma A549 Cells. Biol Pharm Bull 2019; 42:247-254. [PMID: 30713254 DOI: 10.1248/bpb.b18-00670] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Abnormal expression of the tight junctional components claudins (CLDNs) is observed in various malignant tissues. We reported recently that CLDN18 expression is down-regulated in human lung adenocarcinoma tissues. In the present study, we investigated the biological functions of CLDN18 using lung adenocarcinoma A549 cells. Microarray analysis showed that CLDN18 increases zonula occludens (ZO)-2 expression in A549 cells. The ectopic expression of CLDN18 increased nuclear ZO-2 levels, which were inhibited by N-[2-[[3-(4-bromophenyl)-2-propen-1-yl]amino]ethyl]5-isoquinolinesulfonamide (H-89), a nonspecific protein kinase A (PKA) inhibitor, but not by a PKA inhibitor 14-22 amide. In addition, dibutyryl cyclic adenosine monophosphate, an analogue of PKA, did not increase ZO-2 levels. These results suggest that H-89 sensitive factors without PKA are involved in the CLDN18-induced elevation of ZO-2. The cell cycle was affected by neither ZO-2 knockdown in CLDN18-expresssing A549 (CLDN18/A549) cells nor ZO-2 overexpression in A549 cells, suggesting that ZO-2 does not play an important role in the regulation of cell proliferation. The introduction of ZO-2 small interfering RNA (siRNA) into CLDN18/A549 cells increased migration, the expression and activity of matrix metalloproteinase 2 (MMP2), and the reporter activity of an MMP2 promoter construct. Furthermore, H-89 enhanced both mRNA levels and reporter activity of MMP2 in CLDN18/A549 cells. These results suggested that a reduction in CLDN18-dependent ZO-2 expression enhances MMP2 expression in lung adenocarcinoma cells, resulting in the promotion of the cell migration. CLDN18 may be a novel marker for metastasis in lung adenocarcinoma.
Collapse
Affiliation(s)
- Risa Akizuki
- Laboratory of Biochemistry, Department of Biopharmaceutical Sciences,Gifu Pharmaceutical University
| | - Hiroaki Eguchi
- Laboratory of Biochemistry, Department of Biopharmaceutical Sciences,Gifu Pharmaceutical University
| | - Satoshi Endo
- Laboratory of Biochemistry, Department of Biopharmaceutical Sciences,Gifu Pharmaceutical University
| | - Toshiyuki Matsunaga
- Laboratory of Biochemistry, Department of Biopharmaceutical Sciences,Gifu Pharmaceutical University
| | - Akira Ikari
- Laboratory of Biochemistry, Department of Biopharmaceutical Sciences,Gifu Pharmaceutical University
| |
Collapse
|
30
|
Zaiets IV, Holiar VV, Sivchenko AS, Smialkovska VV, Filonenko VV. p60-S6K1 represents a novel kinase active isoform with the mode of regulation distinct from p70/p85-S6K1 isoforms. UKRAINIAN BIOCHEMICAL JOURNAL 2019. [DOI: 10.15407/ubj91.04.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
|
31
|
Lamm N, Rogers S, Cesare AJ. The mTOR pathway: Implications for DNA replication. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2019; 147:17-25. [PMID: 30991055 DOI: 10.1016/j.pbiomolbio.2019.04.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Revised: 04/01/2019] [Accepted: 04/09/2019] [Indexed: 12/22/2022]
Abstract
DNA replication plays a central role in genome health. Deleterious alteration of replication dynamics, or "replication stress", is a key driver of genome instability and oncogenesis. The replication stress response is regulated by the ATR kinase, which functions to mitigate replication abnormalities through coordinated efforts that arrest the cell cycle and repair damaged replication forks. mTOR kinase regulates signaling networks that control cell growth and metabolism in response to environmental cues and cell stress. In this review, we discuss interconnectivity between the ATR and mTOR pathways, and provide putative mechanisms for mTOR engagement in DNA replication and the replication stress response. Finally, we describe how connectivity between mTOR and replication stress may be exploited for cancer therapy.
Collapse
Affiliation(s)
- Noa Lamm
- Genome Integrity Unit, Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, 2145, Australia
| | - Samuel Rogers
- Genome Integrity Unit, Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, 2145, Australia
| | - Anthony J Cesare
- Genome Integrity Unit, Children's Medical Research Institute, University of Sydney, Westmead, New South Wales, 2145, Australia.
| |
Collapse
|
32
|
Qiu Z, Zhang C, Zhou J, Hu J, Sheng L, Li X, Chen L, Li X, Deng X, Zheng G. Celecoxib alleviates AKT/c-Met-triggered rapid hepatocarcinogenesis by suppressing a novel COX-2/AKT/FASN cascade. Mol Carcinog 2018; 58:31-41. [PMID: 30182439 DOI: 10.1002/mc.22904] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 08/13/2018] [Accepted: 08/31/2018] [Indexed: 02/06/2023]
Abstract
Previous studies have demonstrated that the selective cyclooxygenase-2 (COX-2) inhibitor celecoxib shows efficacy against multiple cancers, including hepatocellular carcinoma. However, whether celecoxib is effective in alleviating steatosis during hepatocarcinogenesis is unknown. In a rapid hepatocellular carcinoma (HCC) mouse model established via hydrodynamic transfection of activated forms of AKT and c-Met proto-oncogenes, we investigated the antisteatotic and anticarcinogenic efficacy of celecoxib in vivo. Multiple HCC cell lines were employed for in vitro evaluation. Additionally, immunoblotting, immunohistochemistry, hematoxylin and eosin staining and Oil Red O staining were applied for mechanistic investigation. The results revealed that if celecoxib was administered in the early stage of AKT/c-Met-induced HCC, it resulted in disease stabilization. Moreover, celecoxib could alleviate lipid accumulation in the HCC mice and in an oleic acid-induced in vitro hepatic steatosis model. Further evidence at the molecular level indicated that celecoxib down-regulated the expression of phospho-ERK (Thr202/Tyr204) and proliferating cell nuclear antigen (PCNA) in the HCC mice. In addition, celecoxib efficiently repressed the phosphor-Akt (Thr308)/fatty acid synthase (FASN) axis both in vivo and in vitro. Altogether, this study suggests that celecoxib exerts its antilipogenic efficacy by targeting a COX-2/AKT/FASN cascade, which contributes to its ability to delay hepatocarcinogenesis.
Collapse
Affiliation(s)
- Zhenpeng Qiu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Cong Zhang
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Junxuan Zhou
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Junjie Hu
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Lei Sheng
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Xin Li
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Liang Chen
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Xiang Li
- College of Pharmacy, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| | - Xukun Deng
- College of Pharmacy, South-Central University for Nationalities, Wuhan, People's Republic of China
| | - Guohua Zheng
- Key Laboratory of Chinese Medicine Resource and Compound Prescription, Ministry of Education, Hubei University of Chinese Medicine, Wuhan, People's Republic of China
| |
Collapse
|
33
|
Yang C, Huang X, Liu H, Xiao F, Wei J, You L, Qian W. PDK1 inhibitor GSK2334470 exerts antitumor activity in multiple myeloma and forms a novel multitargeted combination with dual mTORC1/C2 inhibitor PP242. Oncotarget 2018; 8:39185-39197. [PMID: 28402933 PMCID: PMC5503605 DOI: 10.18632/oncotarget.16642] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Accepted: 03/06/2017] [Indexed: 12/17/2022] Open
Abstract
A deeper understanding of the complex pathogenesis of multiple myeloma (MM) continues to lead to novel therapeutic approaches. Prior studies suggest that 3-phosphoinositide-dependent kinase 1 (PDK1) is expressed and active, acting as a crucial regulator of molecules that are essential for myelomagenesis. In the present study, we show that GSK2334470 (GSK-470), a novel and highly specific inhibitor of PDK1, induces potent cytotoxicity in MM cell lines including Dexamethasone-resistant cell line, but not in human normal cells. Insulin-like growth factor-1 could not rescue GSK-470-induced cell death. Moreover, GSK-470 down-modulates phosphor-PDK1, thereby inhibiting downstream phosphor-AKT at Thr308 and mTOR complex 1 (mTORC1) activity. However, GSK-470 could not affect mTORC2 activity and phosphor-AKT at Ser473. RPMI 8226 and OPM-2 cells with low expression of PTEN show relative resistant to GSK-470. Knockout of PTEN by shRNA resulted in a partial reversion of GSK-470-mediated growth inhibition, whereas overexpression of PTEN enhanced myeloma cell sensitivity to GSK-470, suggesting that the sensitivity to GSK-470 is correlated with PTEN expression statue in MM cells. Combining PP242, a dual mTORC1/C2 inhibitor, with GSK-470, had greater antimyeloma activity than either one alone in vitro and in MM xenograft model established in immunodeficient mice. In particular, this combination was able to result in a complete inhibition of mTORC1/C2 and full activity of AKT. Together, these findings raise the possibility that combining PDK1 antagonist GSK-470 with mTORC1/C2 inhibitors may represent a novel strategy against MM including drug-resistant myeloma, regardless of PTEN expression status.
Collapse
Affiliation(s)
- Chunmei Yang
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Xianbo Huang
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Hui Liu
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Feng Xiao
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Jueying Wei
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Liangshun You
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| | - Wenbin Qian
- Institute of Hematology, the First Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, 310003, P.R. China
| |
Collapse
|
34
|
Kodamullil AT, Iyappan A, Karki R, Madan S, Younesi E, Hofmann-Apitius M. Of Mice and Men: Comparative Analysis of Neuro-Inflammatory Mechanisms in Human and Mouse Using Cause-and-Effect Models. J Alzheimers Dis 2018; 59:1045-1055. [PMID: 28731442 PMCID: PMC5545904 DOI: 10.3233/jad-170255] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Perturbance in inflammatory pathways have been identified as one of the major factors which leads to neurodegenerative diseases (NDD). Owing to the limited access of human brain tissues and the immense complexity of the brain, animal models, specifically mouse models, play a key role in advancing the NDD field. However, many of these mouse models fail to reproduce the clinical manifestations and end points of the disease. NDD drugs, which passed the efficacy test in mice, were repeatedly not successful in clinical trials. There are numerous studies which are supporting and opposing the applicability of mouse models in neuroinflammation and NDD. In this paper, we assessed to what extend a mouse can mimic the cellular and molecular interactions in humans at a mechanism level. Based on our mechanistic modeling approach, we investigate the failure of a neuroinflammation targeted drug in the late phases of clinical trials based on the comparative analyses between the two species.
Collapse
Affiliation(s)
- Alpha Tom Kodamullil
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany.,Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn-Aachen International Center for IT, Bonn, Germany
| | - Anandhi Iyappan
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany.,Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn-Aachen International Center for IT, Bonn, Germany
| | - Reagon Karki
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany.,Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn-Aachen International Center for IT, Bonn, Germany
| | - Sumit Madan
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany.,Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn-Aachen International Center for IT, Bonn, Germany
| | - Erfan Younesi
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany
| | - Martin Hofmann-Apitius
- Department of Bioinformatics, Fraunhofer Institute for Algorithms and Scientific Computing, Sankt Augustin, Germany.,Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn-Aachen International Center for IT, Bonn, Germany
| |
Collapse
|
35
|
Tuo Y, Xiang M. mTOR: A double‐edged sword for diabetes. J Leukoc Biol 2018; 106:385-395. [DOI: 10.1002/jlb.3mr0317-095rr] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2017] [Revised: 09/05/2017] [Accepted: 09/14/2017] [Indexed: 12/14/2022] Open
Affiliation(s)
- Yali Tuo
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
| | - Ming Xiang
- Department of PharmacologySchool of PharmacyTongji Medical CollegeHuazhong University of Science and Technology Wuhan China
| |
Collapse
|
36
|
Torres P, Castro M, Reyes M, Torres VA. Histatins, wound healing, and cell migration. Oral Dis 2018; 24:1150-1160. [PMID: 29230909 DOI: 10.1111/odi.12816] [Citation(s) in RCA: 52] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 12/04/2017] [Accepted: 12/05/2017] [Indexed: 12/20/2022]
Abstract
Wounds in the oral mucosa heal faster and more efficiently than those in the skin, although the mechanisms underlying these differences are not completely clear. In the last 10 years, a group of salivary peptides, the histatins, has gained attention on behalf of their ability to improve several phases of the wound-healing process. In addition to their roles as anti-microbial agents and in enamel maintenance, histatins elicit other biological effects, namely by promoting the migration of different cell types contained in the oral mucosa and in non-oral tissues. Histatins, and specifically histatin-1, promote cell adhesion and migration in oral keratinocytes, gingival and dermal fibroblasts, non-oral epithelial cells, and endothelial cells. This is particularly relevant, as histatin-1 promotes the re-epithelialization phase and the angiogenic responses by increasing epithelial and endothelial cell migration. Although the molecular mechanisms associated with histatin-dependent cell migration remain poorly understood, recent studies have pointed to the control of signaling endosomes and the balance of small GTPases. This review aimed to update the literature on the effects of histatins in cell migration, with a focus on wound healing. We will also discuss the consequences that this increasing field will have in disease and therapy design.
Collapse
Affiliation(s)
- P Torres
- Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile
| | - M Castro
- Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile
| | - M Reyes
- Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile
| | - V A Torres
- Faculty of Dentistry, Institute for Research in Dental Sciences, Universidad de Chile, Santiago, Chile.,Advanced Center for Chronic Diseases (ACCDiS), Universidad de Chile, Santiago, Chile
| |
Collapse
|
37
|
AntogomiR-451 protects human gastric epithelial cells from ethanol via activating AMPK signaling. Biochem Biophys Res Commun 2018; 497:339-346. [PMID: 29432731 DOI: 10.1016/j.bbrc.2018.02.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2018] [Accepted: 02/08/2018] [Indexed: 12/25/2022]
Abstract
The prevention and treatment efficiency of ethanol-induced gastric epithelial injury are not satisfied. We have previously shown that AMP-activated protein kinase (AMPK) activation exerts a pro-survival function in human gastric epithelial cells (GECs). miroRNA-451 ("miR-451")'s inhibitor, antagomiR-451, can activate AMPK signaling. In the present study, we show that forced-expression of antagomiR-451 via a lentiviral vector depleted miR-451, leading to AMPK activation in established GES-1 cells and primary human GECs. AntagomiR-451 efficiently protected GES-1 cells and primary human GECs from ethanol-induced viability reduction and apoptosis. AMPK activation is required for antagomiR-451-induced GEC protection. AMPKα1 knockdown (by targeted-shRNAs) or knockout (by CRISPR-Cas-9 KO plasmid) blocked antagomiR-451-induced AMPK activation, and GEC protection against ethanol. Further experimental results show that antagomiR-451 significantly attenuated ethanol-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage. Collectively, antagomiR-451 protects human GECs from ethanol via activating AMPK signaling.
Collapse
|
38
|
Xu M, Han X, Liu R, Li Y, Qi C, Yang Z, Zhao C, Gao J. PDK1 Deficit Impairs the Development of the Dentate Gyrus in Mice. Cereb Cortex 2018; 29:1185-1198. [DOI: 10.1093/cercor/bhy024] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2017] [Indexed: 12/22/2022] Open
Affiliation(s)
- Min Xu
- Department of Neurobiology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, China
| | - Xiaoning Han
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, China
| | - Rui Liu
- Department of Neurobiology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, China
| | - Yanjun Li
- Model Animal Research Center of Nanjing University and MOE Key Laboratory of Model Animals for Disease Study, Nanjing, China
| | - Cui Qi
- Department of Neurobiology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, China
| | - Zhongzhou Yang
- Model Animal Research Center of Nanjing University and MOE Key Laboratory of Model Animals for Disease Study, Nanjing, China
| | - Chunjie Zhao
- Key Laboratory of Developmental Genes and Human Diseases, MOE, Department of Histology and Embryology, School of Medicine, Southeast University, Nanjing, China
- Center of Depression, Beijing Institute for Brain Disorders, Beijing, China
| | - Jun Gao
- Department of Neurobiology, Nanjing Medical University, Nanjing, China
- Key Laboratory of Human Functional Genomics of Jiangsu, Nanjing Medical University, Nanjing, China
| |
Collapse
|
39
|
The Protective Effects of IGF-I against β-Amyloid-related Downregulation of Hippocampal Somatostatinergic System Involve Activation of Akt and Protein Kinase A. Neuroscience 2018; 374:104-118. [PMID: 29406271 DOI: 10.1016/j.neuroscience.2018.01.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/14/2017] [Accepted: 01/18/2018] [Indexed: 12/13/2022]
Abstract
Somatostatin (SRIF), a neuropeptide highly distributed in the hippocampus and involved in learning and memory, is markedly reduced in the brain of Alzheimer's disease patients. The effects of insulin-like growth factor-I (IGF-I) against β amyloid (Aβ)-induced neuronal death and associated cognitive disorders have been extensively reported in experimental models of this disease. Here, we examined the effect of IGF-I on the hippocampal somatostatinergic system in Aβ-treated rats and the molecular mechanisms associated with changes in this peptidergic system. Intracerebroventricular Aβ25-35 administration during 14 days (300 pmol/day) to male rats increased Aβ25-35 levels and cell death and markedly reduced SRIF and SRIF receptor 2 levels in the hippocampus. These deleterious effects were associated with reduced Akt and cAMP response element-binding protein (CREB) phosphorylation and activation of c-Jun N-terminal kinase (JNK). Subcutaneous IGF-I co-administration (50 µg/kg/day) reduced hippocampal Aβ25-35 levels, cell death and JNK activation. In addition, IGF-I prevented the reduction in the components of the somatostatinergic system affected by Aβ infusion. Its co-administration also augmented protein kinase A (PKA) activity, as well as Akt and CREB phosphorylation. These results suggest that IGF-I co-administration may have protective effects on the hippocampal somatostatinergic system against Aβ insult through up-regulation of PKA activity and Akt and CREB phosphorylation.
Collapse
|
40
|
Gagliardi PA, Puliafito A, Primo L. PDK1: At the crossroad of cancer signaling pathways. Semin Cancer Biol 2018; 48:27-35. [DOI: 10.1016/j.semcancer.2017.04.014] [Citation(s) in RCA: 92] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/28/2017] [Accepted: 04/26/2017] [Indexed: 12/28/2022]
|
41
|
Abstract
Akt/protein kinase B (PKB) is a serine/threonine kinase which is implicated in mediating a variety of biological responses including cell growth, proliferation and survival. Akt is activated by phosphorylation on two critical residues, namely threonine 308 (Thr308) and serine 473 (Ser473). Several studies have found Akt2 to be amplified or overexpressed at the mRNA level in various tumor cell lines and in a number of human malignancies such as colon, pancreatic and breast cancers. Nevertheless, activation of Akt isoforms by phosphorylation appears to be more clinically significant than Akt2 amplification or overexpression. Many studies in the past 4–5 years have revealed a prognostic and/or predictive role of Akt phosphorylation in breast, prostate and non-small cell lung cancer. Several publications suggest a role of phosphorylated Akt also in endometrial, pancreatic, gastric, tongue and renal cancer. However, different types of assays were used in these studies. Before assessment of P-Akt can be incorporated into routine clinical practice, all aspects of the assay methodology will have to be standardized.
Collapse
Affiliation(s)
- J. Cicenas
- Evolutionary Biology, Zoological Institute, University of Basel, Basel - Switzerland
| |
Collapse
|
42
|
MiR-375 inhibits the hepatocyte growth factor-elicited migration of mesenchymal stem cells by downregulating Akt signaling. Cell Tissue Res 2018; 372:99-114. [PMID: 29322249 DOI: 10.1007/s00441-017-2765-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Accepted: 09/04/2017] [Indexed: 01/04/2023]
Abstract
The migration of mesenchymal stem cells (MSCs) is critical for their use in cell-based therapies. Accumulating evidence suggests that microRNAs are important regulators of MSC migration. Here, we report that the expression of miR-375 was downregulated in MSCs treated with hepatocyte growth factor (HGF), which strongly stimulates the migration of these cells. Overexpression of miR-375 decreased the transfilter migration and the migration velocity of MSCs triggered by HGF. In our efforts to determine the mechanism by which miR-375 affects MSC migration, we found that miR-375 significantly inhibited the activation of Akt by downregulating its phosphorylation at T308 and S473, but had no effect on the activity of mitogen-activated protein kinases. Further, we showed that 3'phosphoinositide-dependent protein kinase-1 (PDK1), an upstream kinase necessary for full activation of Akt, was negatively regulated by miR-375 at the protein level. Moreover, miR-375 suppressed the phosphorylation of focal adhesion kinase (FAK) and paxillin, two important regulators of focal adhesion (FA) assembly and turnover, and decreased the number of FAs at cell periphery. Taken together, our results demonstrate that miR-375 inhibits HGF-elicited migration of MSCs through downregulating the expression of PDK1 and suppressing the activation of Akt, as well as influencing the tyrosine phosphorylation of FAK and paxillin and FA periphery distribution.
Collapse
|
43
|
Park-Windhol C, Ng YS, Yang J, Primo V, Saint-Geniez M, D'Amore PA. Endomucin inhibits VEGF-induced endothelial cell migration, growth, and morphogenesis by modulating VEGFR2 signaling. Sci Rep 2017; 7:17138. [PMID: 29215001 PMCID: PMC5719432 DOI: 10.1038/s41598-017-16852-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Accepted: 11/19/2017] [Indexed: 12/19/2022] Open
Abstract
Angiogenesis is central to both normal and pathologic processes. Endothelial cells (ECs) express O-glycoproteins that are believed to play important roles in vascular development and stability. Endomucin-1 (EMCN) is a type I O-glycosylated, sialic-rich glycoprotein, specifically expressed by venous and capillary endothelium. Evidence has pointed to a potential role for EMCN in angiogenesis but it had not been directly investigated. In this study, we examined the role of EMCN in angiogenesis by modulating EMCN levels both in vivo and in vitro. Reduction of EMCN in vivo led to the impairment of angiogenesis during normal retinal development in vivo. To determine the cellular basis of this inhibition, gain- and loss-of-function studies were performed in human retinal EC (HREC) in vitro by EMCN over-expression using adenovirus or EMCN gene knockdown by siRNA. We show that EMCN knockdown reduced migration, inhibited cell growth without compromising cell survival, and suppressed tube morphogenesis of ECs, whereas over-expression of EMCN led to increased migration, proliferation and tube formation. Furthermore, knockdown of EMCN suppressed VEGF-induced signaling as measured by decreased phospho-VEGFR2, phospho-ERK1/2 and phospho-p38-MAPK levels. These results suggest a novel role for EMCN as a potent regulator of angiogenesis and point to its potential as a new therapeutic target for angiogenesis-related diseases.
Collapse
Affiliation(s)
- Cindy Park-Windhol
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Yin Shan Ng
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Jinling Yang
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Vincent Primo
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Magali Saint-Geniez
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Patricia A D'Amore
- Schepens Eye Research Institute/Massachusetts Eye and Ear, Boston, MA, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
- Department of Pathology, Harvard Medical School, Boston, MA, USA.
| |
Collapse
|
44
|
Anderson KGV, Hamilton WB, Roske FV, Azad A, Knudsen TE, Canham M, Forrester LM, Brickman JM. Insulin fine-tunes self-renewal pathways governing naive pluripotency and extra-embryonic endoderm. Nat Cell Biol 2017; 19:1164-1177. [DOI: 10.1038/ncb3617] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 08/17/2017] [Indexed: 12/16/2022]
|
45
|
Zhang C, Luo H, Huang L, Lin S. Molecular mechanism of glucose-6-phosphate utilization in the dinoflagellate Karenia mikimotoi. HARMFUL ALGAE 2017; 67:74-84. [PMID: 28755722 DOI: 10.1016/j.hal.2017.06.006] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 06/19/2017] [Accepted: 06/19/2017] [Indexed: 06/07/2023]
Abstract
Phosphorus (P) is an essential nutrient for marine phytoplankton as for other living organisms, and the preferred form, dissolved inorganic phosphate (DIP), is often quickly depleted in the sunlit layer of the ocean. Phytoplankton have developed mechanisms to utilize organic forms of P (DOP). Hydrolysis of DOP to release DIP by alkaline phosphatase is believed to be the most common mechanism of DOP utilization. Little effort has been made, however, to understand other potential molecular mechanisms of utilizing different types of DOP. This study investigated the bioavailability of glucose-6-phosphate (G6P) and its underlying molecular mechanism in the dinoflagellate Karenia mikimotoi. Suppression Subtraction Hybridization (SSH) was used to identify genes up- and down-regulated during G6P utilization compared to DIP condition. The results showed that G6P supported the growth and yield of K. mikimotoi as efficiently as DIP. Neither DIP release nor AP activity was detected in the cultures grown in G6P medium, however, suggesting direct uptake of G6P. SSH analysis and RT-qPCR results showed evidence of metabolic modifications, particularly that mitochondrial ATP synthase f1gamma subunit and thioredoxin reductase were up-regulated while diphosphatase and pyrophosphatase were down-regulated in the G6P cultures. All the results indicate that K. mikimotoi has developed a mechanism other than alkaline phosphatase to utilize G6P.
Collapse
Affiliation(s)
- Chao Zhang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China; Institute of Genetic Engineering, Southern Medical University, Guangzhou, China, Guangdong Province Key Laboratory of Biochip, School of Basic Medical Science, Southern Medical University, Guangzhou, China
| | - Hao Luo
- Key State Laboratory of Marine Environmental Science and Marine Biodiversity and Global Change Research Center, Xiamen University, Xiamen, Fujian, China
| | - Liangmin Huang
- South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou, Guangdong, China
| | - Senjie Lin
- Key State Laboratory of Marine Environmental Science and Marine Biodiversity and Global Change Research Center, Xiamen University, Xiamen, Fujian, China; Department of Marine Sciences, University of Connecticut, Groton, CT 06340, USA.
| |
Collapse
|
46
|
Gocher AM, Azabdaftari G, Euscher LM, Dai S, Karacosta LG, Franke TF, Edelman AM. Akt activation by Ca 2+/calmodulin-dependent protein kinase kinase 2 (CaMKK2) in ovarian cancer cells. J Biol Chem 2017. [PMID: 28634229 DOI: 10.1074/jbc.m117.778464] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Hyperactivation of Akt is associated with oncogenic changes in the growth, survival, and chemoresistance of cancer cells. The PI3K/phosphoinositide-dependent kinase (PDK) 1 pathway represents the canonical mechanism for phosphorylation of Akt at its primary activation site, Thr-308. We observed that Ca2+/calmodulin (CaM)-dependent protein kinase kinase 2 (β) (CaMKK2) is highly expressed in high-grade serous ovarian cancer, and we investigated its role in Akt activation in ovarian cancer (OVCa) cell lines (OVCAR-3, SKOV-3, and Caov-3). Knockdown or pharmacological inhibition of CaMKK2 produced phenotypes expected of Akt inhibition, including reductions in cell growth and cell viability and in the regulation of Akt downstream targets involved in G1/S transition and apoptosis. CaMKK2 knockdown or inhibition decreased Akt phosphorylation at Thr-308 and Ser-473 to extents similar to those of PDK1 knockdown or PI3K inhibition. Combined CaMKK2 and PDK1 knockdown or CaMKK and PI3K inhibition, respectively, produced additive effects on p-Akt and cell growth, consistent with direct Akt phosphorylation by CaMKK2. This conclusion was supported by the absence of effects of CaMKK2 knockdown/inhibition on alternative means of activating Akt via p-Akt Thr-450, p-PDK1 Ser-241, or p-IRS1 Ser-636/639. Recombinant CaMKK2 directly activated recombinant Akt by phosphorylation at Thr-308 in a Ca2+/CaM-dependent manner. In OVCa cells, p-Akt Thr-308 was significantly inhibited by intracellular Ca2+i chelation or CaM inhibition. Ionomycin-induced Ca2+ influx promoted p-Akt, an effect blocked by PDK1, and/or CaMKK2, siRNAs, and by PI3K and/or CaMKK inhibitors. CaMKK2 knockdown potentiated the effects of the chemotherapeutic drugs carboplatin and PX-866 to reduce proliferation and survival of OVCa cells.
Collapse
Affiliation(s)
- Angela M Gocher
- From the Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, New York 14214
| | - Gissou Azabdaftari
- Department of Pathology and Laboratory Medicine, Roswell Park Cancer Institute, Buffalo, New York 14263
| | - Lindsey M Euscher
- From the Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, New York 14214
| | - Shuhang Dai
- From the Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, New York 14214
| | - Loukia G Karacosta
- From the Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, New York 14214
| | - Thomas F Franke
- Department of Psychiatry, Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, New York 10016
| | - Arthur M Edelman
- From the Department of Pharmacology and Toxicology, State University of New York at Buffalo, Buffalo, New York 14214,.
| |
Collapse
|
47
|
Yang X, He XQ, Li GD, Xu YQ. AntagomiR-451 inhibits oxygen glucose deprivation (OGD)-induced HUVEC necrosis via activating AMPK signaling. PLoS One 2017; 12:e0175507. [PMID: 28445531 PMCID: PMC5405932 DOI: 10.1371/journal.pone.0175507] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Accepted: 03/27/2017] [Indexed: 01/14/2023] Open
Abstract
Oxygen glucose deprivation (OGD) application in cultured human umbilical vein endothelial cells (HUVECs) mimics ischemic injuries. AntagomiR-451, the miroRNA-451 ("miR-451") inhibitor, could activate pro-survival AMP-activated protein kinase (AMPK) signaling. In the current study, we showed that forced-expression of antagomiR-451 depleted miRNA-451 and significantly attenuated OGD-induced necrosis of HUVECs. Activation of AMPK was required for antagomiR-451-mediated pro-survival actions. AMPK inhibition, by AMPKα shRNA or dominant negative mutation, almost completely abolishedantagomiR-451-mediated HUVEC protection again OGD. Reversely, forced-activation of AMPK by exogenous expression of constructively-active AMPKα inhibited OGD-induced HUVEC necrosis. At the molecular level, antagomiR-451 expression in HUVECs inhibited OGD-induced programmed necrosis, the latter was evidenced by mitochondrial p53-cyclophilinD (Cyp-D) association, mitochondrial depolarization as well as reactive oxygen species (ROS) production and lactate dehydrogenase (LDH) breach. Together, we suggest that antagomiR-451 activates AMPK to inhibit OGD-induced programmed necrosis in HUVECs.
Collapse
Affiliation(s)
- Xi Yang
- Department of Orthopedics, Kunming General Hospital, PLA, Kunming, China
- Brigade of Postgraduate Management, Third Military Medical University, Chongqing, China
| | - Xiao-Qing He
- Department of Orthopedics, Kunming General Hospital, PLA, Kunming, China
| | - Guo-Dong Li
- Department of Orthopedics, Kunming General Hospital, PLA, Kunming, China
| | - Yong-Qing Xu
- Department of Orthopedics, Kunming General Hospital, PLA, Kunming, China
| |
Collapse
|
48
|
Kolar D, Gresikova M, Waskova-Arnostova P, Elsnicova B, Kohutova J, Hornikova D, Vebr P, Neckar J, Blahova T, Kasparova D, Novotny J, Kolar F, Novakova O, Zurmanova JM. Adaptation to chronic continuous hypoxia potentiates Akt/HK2 anti-apoptotic pathway during brief myocardial ischemia/reperfusion insult. Mol Cell Biochem 2017; 432:99-108. [PMID: 28290047 DOI: 10.1007/s11010-017-3001-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 03/04/2017] [Indexed: 01/30/2023]
Abstract
Adaptation to chronic hypoxia represents a potential cardioprotective intervention reducing the extent of acute ischemia/reperfusion (I/R) injury, which is a major cause of death worldwide. The main objective of this study was to investigate the anti-apoptotic Akt/hexokinase 2 (HK2) pathway in hypoxic hearts subjected to I/R insult. Hearts isolated from male Wistar rats exposed either to continuous normobaric hypoxia (CNH; 10% O2) or to room air for 3 weeks were perfused according to Langendorff and subjected to 10 min of no-flow ischemia and 10 min of reperfusion. The hearts were collected either after ischemia or after reperfusion and used for protein analyses and quantitative fluorescence microscopy. The CNH resulted in increased levels of HK1 and HK2 proteins and the total HK activity after ischemia compared to corresponding normoxic group. Similarly, CNH hearts exhibited increased ischemic level of Akt protein phosphorylated on Ser473. The CNH also strengthened the interaction of HK2 with mitochondria and prevented downregulation of mitochondrial creatine kinase after reperfusion. The Bax/Bcl-2 ratio was significantly lower after I/R in CNH hearts than in normoxic ones, suggesting a lower probability of apoptosis. In conclusion, the Akt/HK2 pathway is likely to play a role in the development of a cardioprotective phenotype of CNH by preventing the detachment of HK2 from mitochondria at reperfusion period and decreases the Bax/Bcl-2 ratio during I/R insult, thereby lowering the probability of apoptosis activation in the mitochondrial compartment.
Collapse
Affiliation(s)
- David Kolar
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Milada Gresikova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Petra Waskova-Arnostova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Barbara Elsnicova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jana Kohutova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Daniela Hornikova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Pavel Vebr
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jan Neckar
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Tereza Blahova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Dita Kasparova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jiri Novotny
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Frantisek Kolar
- Institute of Physiology, Czech Academy of Sciences, Prague, Czech Republic
| | - Olga Novakova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Jitka M Zurmanova
- Department of Physiology, Faculty of Science, Charles University in Prague, Prague, Czech Republic.
| |
Collapse
|
49
|
Park SY, Yoon SN, Kang MJ, Lee Y, Jung SJ, Han JS. Hippocalcin Promotes Neuronal Differentiation and Inhibits Astrocytic Differentiation in Neural Stem Cells. Stem Cell Reports 2016; 8:95-111. [PMID: 28017654 PMCID: PMC5233403 DOI: 10.1016/j.stemcr.2016.11.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 11/22/2016] [Accepted: 11/23/2016] [Indexed: 11/23/2022] Open
Abstract
Hippocalcin (HPCA) is a calcium-binding protein that is restricted to nervous tissue and contributes to neuronal activity. Here we report that, in addition to inducing neurogenesis, HPCA inhibits astrocytic differentiation of neural stem cells. It promotes neurogenesis by regulating protein kinase Cα (PKCα) activation by translocating to the membrane and binding to phosphoinositide-dependent protein kinase 1 (PDK1), which induces PKCα phosphorylation. We also found that phospholipase D1 (PLD1) is implicated in the HPCA-mediated neurogenesis pathway; this enzyme promotes dephosphorylation of signal transducer and activator of transcription 3 (STAT3[Y705]), which is necessary for astrocytic differentiation. Moreover, we found that the SH2-domain-containing tyrosine phosphatase 1 (SHP-1) acts upstream of STAT3. Importantly, this SHP-1-dependent STAT3-inhibitory mechanism is closely involved in neurogenesis and suppression of gliogenesis by HPCA. Taken together, these observations suggest that HPCA promotes neuronal differentiation through activation of the PKCα/PLD1 cascade followed by activation of SHP-1, which dephosphorylates STAT3(Y705), leading to inhibition of astrocytic differentiation. Hippocalcin is required for neuronal differentiation in neural stem cells PKCα/PLD1 activation is required for hippocalcin-mediated neuronal differentiation Blocking of STAT3(Y705) activity by hippocalcin decreases astrocytic differentiation Hippocalcin promotes neurogenesis by inhibiting gliogenesis in neural stem cells
Collapse
Affiliation(s)
- Shin-Young Park
- Department of Biochemistry and Molecular Biology, Biomedical Research Institute, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Sung Nyo Yoon
- Department of Biochemistry and Molecular Biology, Biomedical Research Institute, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Min-Jeong Kang
- Department of Biochemistry and Molecular Biology, Biomedical Research Institute, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - YunYoung Lee
- Department of Biochemistry and Molecular Biology, Biomedical Research Institute, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Sung Jun Jung
- Department of Physiology, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea
| | - Joong-Soo Han
- Department of Biochemistry and Molecular Biology, Biomedical Research Institute, College of Medicine, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul 04763, Republic of Korea.
| |
Collapse
|
50
|
Yang Y, Kong W, Xia Z, Xiao L, Wang S. Regulation mechanism of PDK1 on macrophage metabolism and function. Cell Biochem Funct 2016; 34:546-553. [DOI: 10.1002/cbf.3235] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 09/11/2016] [Accepted: 10/11/2016] [Indexed: 01/21/2023]
Affiliation(s)
- Yueqin Yang
- Exercise Intervention and Health Promotion Hubei Province Synergy Innovation Center; Wuhan Sports University; Wuhan Hubei China
| | - Weiwei Kong
- Graduate School; Wuhan Sports University; Wuhan Hubei China
| | - Zhi Xia
- Exercise Physiology and Biochemical Laboratory, College of Physical Education; Jinggangshan University; Ji'an Jiangxi China
| | - Lin Xiao
- School of Physical Education and Health Science; Zhaoqing University; Zhaoqing Guangdong China
| | - Song Wang
- Exercise Intervention and Health Promotion Hubei Province Synergy Innovation Center; Wuhan Sports University; Wuhan Hubei China
| |
Collapse
|