1
|
Zhao M, Yang Y, Shi Y, Chen X, Yang Y, Pan L, Du Z, Sun H, Yao C, Ma G, Du A. PP2Acα-B'/PR61 Holoenzyme of Toxoplasma gondii Is Required for the Amylopectin Metabolism and Proliferation of Tachyzoites. Microbiol Spectr 2023; 11:e0010423. [PMID: 37199633 PMCID: PMC10269777 DOI: 10.1128/spectrum.00104-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 04/26/2023] [Indexed: 05/19/2023] Open
Abstract
Here, we report that the inhibition of the PP2A subfamily by okadaic acid results in an accumulation of polysaccharides in the acute infection stage (tachyzoites) of Toxoplasma gondii, which is a protozoan of global zoonotic importance and a model for the apicomplexan parasites. The loss of the catalytic subunit α of PP2A (ΔPP2Acα) in RHΔku80 leads to the polysaccharide accumulation phenotype in the base of tachyzoites as well as residual bodies and significantly compromises the intracellular growth in vitro and the virulence in vivo. A metabolomic analysis revealed that the accumulated polysaccharides in ΔPP2Acα are derived from interrupted glucose metabolism, which affects the production of ATP and energy homeostasis in the T. gondii knockout. The assembly of the PP2Acα holoenzyme complex involved in the amylopectin metabolism in tachyzoites is possibly not regulated by LCMT1 or PME1, and this finding contributes to the identification of the regulatory B subunit (B'/PR61). The loss of B'/PR61 results in the accumulation of polysaccharide granules in the tachyzoites as well as reduced plaque formation ability, exactly the same as ΔPP2Acα. Taken together, we have identified a PP2Acα-B'/PR61 holoenzyme complex that plays a crucial role in the carbohydrate metabolism and viability in T. gondii, and its deficiency in function remarkably suppresses the growth and virulence of this important zoonotic parasite both in vitro and in vivo. Hence, rendering the PP2Acα-B'/PR61 holoenzyme functionless should be a promising strategy for the intervention of Toxoplasma acute infection and toxoplasmosis. IMPORTANCE Toxoplasma gondii switches back and forth between acute and chronic infections, mainly in response to host immunologic status, which is characterized by flexible but specific energy metabolism. Polysaccharide granules are accumulated in the acute infection stage of T. gondii that have been exposed to a chemical inhibitor of the PP2A subfamily. The genetic depletion of the catalytic subunit α of PP2A leads to this phenotype and significantly affects the cell metabolism, energy production, and viability. Further, a regulatory B subunit PR61 is necessary for the PP2A holoenzyme to function in glucose metabolism and in the intracellular growth of T. gondii tachyzoites. A deficiency of this PP2A holoenzyme complex (PP2Acα-B'/PR61) in T. gondii knockouts results in the abnormal accumulation of polysaccharides and the disruption of energy metabolism, suppressing their growth and virulence. These findings provide novel insights into cell metabolism and identify a potential target for an intervention against a T. gondii acute infection.
Collapse
Affiliation(s)
- Mingxiu Zhao
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yi Yang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yue Shi
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
- Hainan Institute, Zhejiang University, Yazhou Bay Sci-Tech City, Sanya, China
| | - Xueqiu Chen
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Yimin Yang
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Lingtao Pan
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Zhendong Du
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hongchao Sun
- Department of Animal Parasitology, Institute of Animal Husbandry and Veterinary Medicine, Zhejiang Academy of Agricultural Science, Hangzhou, Zhejiang Province, China
| | - Chaoqun Yao
- Department of Biomedical Sciences and One Health Center for Zoonoses and Tropical Veterinary Medicine, Ross University School of Veterinary Medicine, Basseterre, St. Kitts and Nevis
| | - Guangxu Ma
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
- Department of Veterinary Biosciences, Melbourne Veterinary School, The University of Melbourne, Parkville, Victoria, Australia
| | - Aifang Du
- Institute of Preventive Veterinary Medicine, Zhejiang Provincial Key Laboratory of Preventive Veterinary Medicine, College of Animal Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| |
Collapse
|
2
|
Ting T, Yiwen C, Jianquan C, Chao L, Shengjing X, Min Z, Fang C. PP2Acα regulates epidermal cell proliferation via the EGFR/AKT/mTOR pathway in psoriasis-like skin lesions caused by PPP2CA deficiency. Exp Dermatol 2022; 31:1154-1164. [PMID: 35298048 DOI: 10.1111/exd.14567] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 03/11/2022] [Accepted: 03/14/2022] [Indexed: 11/30/2022]
Abstract
Psoriasis, a common skin disease, endangers human physiological and mental health; however, its pathogenesis remains unclear. Keratinocyte proliferation is a typical pathological characteristic of psoriasis. Serine/threonine protein phosphatase 2A (PP2A) is one of the most important phosphatases for maintaining normal phosphorylation levels in humans. PP2Acα is the alpha subtype of the PP2A C subunit (encoded by PPP2CA), which maintains the catalytic functions of PP2A. Epidermal growth factor receptor (EGFR) is activated by phosphorylation (p-EGFR) to regulate the downstream signaling pathway to promote epidermal cell proliferation. Previous studies have found that PPP2CA induced epidermal hyperplasia, keratinization, and other pathological phenomena similar to those in mouse models of psoriasis. The present study showed that PP2Acα negatively regulated EGFR phosphorylation and epidermal cell proliferation, and EGFR inhibitors could alleviate PP2Acα by inhibiting epidermal cell proliferation. This study further examined the effect of mechanisms on epidermal cell proliferation and the downstream signaling pathway of EGFR using molecular technological methods to explore new ideas for treating psoriasis.
Collapse
Affiliation(s)
- Tao Ting
- Department of Spleen and Stomach, Jiangsu Province Hospital of Chinese Medicine
| | - Chen Yiwen
- Department of Dermatology, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| | - Chen Jianquan
- Central Laboratory, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| | - Lian Chao
- Central Laboratory, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| | - Xu Shengjing
- Department of Dermatology, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| | - Zhang Min
- Department of Dermatology, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| | - Chao Fang
- Department of Dermatology, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China.,Central Laboratory, The Affiliated Jiangning Hospital of Nanjing Medical University District, Nanjing City, China
| |
Collapse
|
3
|
Lu K, Shi TS, Shen SY, Shi Y, Gao HL, Wu J, Lu X, Gao X, Ju HX, Wang W, Cao Y, Chen D, Li CJ, Xue B, Jiang Q. Defects in a liver-bone axis contribute to hepatic osteodystrophy disease progression. Cell Metab 2022; 34:441-457.e7. [PMID: 35235775 DOI: 10.1016/j.cmet.2022.02.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 11/26/2021] [Accepted: 02/08/2022] [Indexed: 12/12/2022]
Abstract
Hepatic osteodystrophy (HOD) is a metabolic bone disease that is often associated with chronic liver disease and is marked by bone loss. Here, we demonstrate that hepatic expression of the phosphatase PP2Acα is upregulated during HOD, leading to the downregulation of expression of the hepatokine lecithin-cholesterol acyltransferase (LCAT). Loss of LCAT function markedly exacerbates the bone loss phenotype of HOD in mice. In addition, we found that alterations in cholesterol levels are involved in the regulation of osteoblast and osteoclast activities. We also found that LCAT improves liver function and relieves liver fibrosis in the mouse HOD model by promoting reversal of cholesterol transport from the bone to the liver. In summary, defects in a liver-bone axis occur during HOD that can be targeted to ameliorate disease progression.
Collapse
Affiliation(s)
- Ke Lu
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, China; Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, 321 Zhongshan Road, Nanjing 210008, China; Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Tian-Shu Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, China; Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, 321 Zhongshan Road, Nanjing 210008, China
| | - Si-Yu Shen
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, China; Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, 321 Zhongshan Road, Nanjing 210008, China
| | - Yong Shi
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, China; Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, 321 Zhongshan Road, Nanjing 210008, China
| | - Hong-Liang Gao
- Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Jing Wu
- Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Xiang Lu
- Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China
| | - Xiang Gao
- Model Animal Research Center of Nanjing University, Xuefu Road, Nanjing 210032, China
| | - Huang-Xian Ju
- State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing 210023, China
| | - Wei Wang
- National Laboratory of Solid-State Microstructures, Department of Physics, Nanjing University, Nanjing 210093, China
| | - Yi Cao
- National Laboratory of Solid-State Microstructures, Department of Physics, Nanjing University, Nanjing 210093, China
| | - Di Chen
- Faculty of Pharmaceutical Sciences, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China.
| | - Chao-Jun Li
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center of the Medical School, Nanjing University, Nanjing 210093, China; State Key Laboratory of Reproductive Medicine and China International Joint Research Center on Environment and Human Health, Center for Global Health, School of Public Health, Nanjing Medical University, Nanjing 211166, China.
| | - Bin Xue
- Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing 211166, China.
| | - Qing Jiang
- State Key Laboratory of Pharmaceutical Biotechnology, Department of Sports Medicine and Adult Reconstructive Surgery, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, 321 Zhongshan Road, Nanjing 210008, China; Branch of National Clinical Research Center for Orthopedics, Sports Medicine and Rehabilitation, 321 Zhongshan Road, Nanjing 210008, China.
| |
Collapse
|
4
|
Lu Q, Tan M, Hou Q, Wang M, Dai C. PP2A Catalytic Subunit α promotes fibroblast activation and kidney fibrosis via ERK pathway. Cell Signal 2021; 90:110187. [PMID: 34780974 DOI: 10.1016/j.cellsig.2021.110187] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 11/01/2021] [Accepted: 11/02/2021] [Indexed: 11/22/2022]
Abstract
Protein Phosphatase 2A (PP2A), a main serine/threonine phosphatase, plays a profibrotic role in the development of different organs. However, the role and mechanisms of PP2Acα in fibroblast activation and kidney fibrosis are not fully known. Here we found that PP2Acα expression was upregulated in kidney tissue of chronic kidney disease (CKD) patients and unilateral ureter obstructive (UUO) mice. Ablation of fibroblast PP2Acα alleviates fibroblast activation and kidney fibrosis in mouse kidneys with UUO nephropathy compared with the control littermates. In primary cultured fibroblasts, PP2Acα deletion restrains TGFβ1-induced fibroblast activation, which is accompanied by increased phosphorylation of the extracellular regulated kinase (ERK). Blocking ERK pathway activation by PD98059 could promote fibroblast activation, indicating that PP2Acα promotes TGFβ1-induced fibroblast activation via suppressing ERK pathway. Consistently, in vivo, the activation of ERK pathway was upregulated by PP2Acα ablation in kidney fibroblasts. Together, these data uncover that PP2Acα may promote fibroblast activation and kidney fibrosis via suppressing ERK pathway, suggesting that targeting PP2Acα may provide a therapeutic effect for CKD.
Collapse
|
5
|
Tang N, Zhang J, Fu X, Xie W, Qiu Y. PP2Acα inhibits PFKFB2-induced glycolysis to promote termination of liver regeneration. Biochem Biophys Res Commun 2020; 526:1-7. [PMID: 32192773 DOI: 10.1016/j.bbrc.2020.03.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 03/03/2020] [Indexed: 01/17/2023]
Abstract
The mechanisms underlying the initiation and proliferation of liver regeneration (LR) has been extensively studied using the partial hepatectomy (PHx) model, while little is known about the termination of LR. PP2Acα (protein phosphatase 2 A catalytic subunit α isoform) is the catalytic subunit of protein phosphatase 2 A (PP2A), accounting for most of intracellular serine/threonine phosphatase activity. We have previously observed that termination of LR delayed in PP2Acα liver-specific knockout (LKO) mice after PHx. In our study, we used phospho explorer antibody array analysis to screen the potential phosphorylation targets of PP2Acα, and PP2Acα had a great influence on the hepatic phosphoproteomic signaling in the termination of LR after PHx. We then tested the phosphorylation changes and metabolic function of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase-2 (PFKFB2), an isoform of the key glycolytic enzyme PFKFB, which was significantly regulated by PP2Acα knockout. PP2Acα knockout enhanced glycolysis in vivo and in vitro, while adenoviral-mediated RNAi of PFKFB2 reversed the extension of postoperative liver regeneration in KO mice along with the downregulation of glycolysis. Therefore, we demonstrated that PP2Acα liver-specific knockout regulated the hepatocytes glycolysis via activating PFKFB2, thus enhancing liver regeneration during the termination stage.
Collapse
Affiliation(s)
- Neng Tang
- The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Jingzi Zhang
- Medical School and Model Animal Research Center of Nanjing University, Nanjing, China
| | - Xiao Fu
- The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Weiqi Xie
- The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China
| | - Yudong Qiu
- The Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, China.
| |
Collapse
|
6
|
Zhang J, Tang N, Zhao Y, Zhao R, Fu X, Zhao D, Zhao Y, Huang L, Li C, Qiu Y, Xue B, Fang L. Global Phosphoproteomic Analysis Reveals Significant Metabolic Reprogramming in the Termination of Liver Regeneration in Mice. J Proteome Res 2020; 19:1788-1799. [PMID: 32105074 PMCID: PMC7205775 DOI: 10.1021/acs.jproteome.0c00028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Phosphorylation is crucial in regulating various biological processes. However, comprehensive phosphoproteomic profiling in the termination of liver regeneration (LR) is still missing. Here, we used Tandem Mass Tag (TMT) labeling coupled with phosphopeptide enrichment and two-dimensional (2D) liquid chromatography-mass spectrometry (LC-MS)/MS analysis to establish a global phosphoproteomic map in the liver of mice at day 5 after partial hepatectomy (PH). Altogether, 9731 phosphosites from 3443 proteins were identified and 7802 phosphosites from 2980 proteins were quantified. Motif analysis of the identified phosphosites revealed a diverse array of consensus sequences, suggesting that multiple kinase families including ERK/MAPK, PKA/PKC, CaMK-II, CKII, and CDK may be involved in the termination of LR. Functional clustering analysis of proteins with dysregulated phosphosites showed that they mainly participate in metabolic pathways, DNA replication, and tight junction. More importantly, the deletion of PP2Acα in the liver remarkably changes the overall phosphorylation profile, indicating its critical role in regulating the termination of LR. Finally, several differentially phosphorylated sites were validated by co-immunoprecipitation and Western blot. Taken together, our data unravel the first comprehensive phosphoproteomic map in the termination of LR in mice, which greatly expands our knowledge in the complicated regulation of this process and provides new directions for the treatment of liver cancer using liver resection.
Collapse
Affiliation(s)
- Jingzi Zhang
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| | - Neng Tang
- Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing 210093, China
| | - Yinjuan Zhao
- Collaborative Innovation Center of Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing 210037, China
| | - Ruoyu Zhao
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| | - Xiao Fu
- Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing 210093, China
| | - Dandan Zhao
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| | - Yue Zhao
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, CA 92697, USA
| | - Chaojun Li
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| | - Yudong Qiu
- Nanjing Drum Tower Hospital, Medical School of Nanjing University, Nanjing 210093, China
| | - Bin Xue
- Core Laboratory, Sir Run Run Hospital, Nanjing Medical University, Nanjing, 211166, China
| | - Lei Fang
- Model Animal Research Center and Medical School of Nanjing University, Nanjing 210093, China
| |
Collapse
|
7
|
Domínguez-Berrocal L, Zhang X, Zini JM, Fominaya J, Rebollo A, Bravo J. Evaluation of Caspase-9b and PP2Acα2 as potential biomarkers for chronic lymphocytic leukemia. Biomark Res 2016; 4:9. [PMID: 27152197 DOI: 10.1186/s40364-016-0063-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2016] [Accepted: 04/26/2016] [Indexed: 11/17/2022] Open
Abstract
Background Disruption of alternative splicing in apoptotic factors has been associated to chronic lymphocytic leukemia among other cancers and hematological malignancies. The proapoptotic proteins Caspase-9 and PP2Acα are functionally related in a direct interaction, which constitutes a promising target for cancer therapy. Both proteins present aberrant mRNA splicing variants that are antiapoptotic (Caspase-9b) and catalytically inactive (PP2Acα2), respectively. Results In this work we have analyzed the relative abundance of the aberrant spliced forms Caspase-9b and PP2Acα2 in several cell lines and chronic lymphocytic leukemia patients and correlated it with several parameters of the disease. Despite 40 % of the patients presented Caspase-9b dysregulation, there was no direct association between alterations in Caspase-9b relative abundance and the parameters analyzed in medical records. More importantly, PP2Acα2 dysregulation was observed in 88 % of CLL patients and was related with advanced stages of the malignancy. Conclusions Caspase-9b dysregulation seemed to be associated with the disease, although the differences between healthy donors and CLL patients were not statistically significant. However, PP2Acα2 dysregulation was significantly different between healthy donors and CLL patients and correlated with Binet B and C stages; therefore, we propose the use of PP2Acα2 dysregulation as a potential biomarker for advanced stages of chronic lymphocytic leukemia.
Collapse
|