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Chang H, Di T, Wang Y, Zeng X, Li G, Wan Q, Yu W, Chen L. Seipin deletion in mice enhances phosphorylation and aggregation of tau protein through reduced neuronal PPARγ and insulin resistance. Neurobiol Dis 2019; 127:350-361. [PMID: 30910747 DOI: 10.1016/j.nbd.2019.03.023] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [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: 11/05/2018] [Revised: 02/23/2019] [Accepted: 03/21/2019] [Indexed: 12/31/2022] Open
Abstract
Congenital generalized lipodystrophy 2 (CGL2) is characterized by loss of adipose tissue, insulin resistance and cognitive deficits and caused by mutation of BSCL2/seipin gene. Seipin deletion in mice and rats causes severe lipodystrophy, insulin resistance, and cognitive impairment. Hippocampal neurons express seipin protein. This study aimed to investigate the influence of systemic seipin knockout (seipin-sKO), neuronal seipin knockout (seipin-nKO) or adipose seipin knockout (seipin-aKO) in hippocampal tau phosphorylation and aggregation. Levels of tau phosphorylation at Thr212/Ser214 and Ser202/Thr205 and oligomer tau protein were increased in seipin-sKO mice and seipin-nKO mice with a decrease in axonal density and expression of PPARγ. Neuronal seipin deletion increased activities of GSK3β and Akt/mTOR signaling, which were corrected by the administration of PPARγ agonist rosiglitazone for 7 days. The autophagosome formation was reduced in seipin-sKO mice and seipin-nKO mice, which was rescued by the Akt and mTOR inhibitors. The administration of rosiglitazone or Akt, mTOR and GSK3β inhibitors for 7 days could correct the hyperphosphorylation and aggregation of tau. On the other hand, seipin-sKO mice appeared insulin resistance and an increase in phosphorylation of tau at Ser396 and JNK, which were corrected by treatment with rosiglitazone for 30 days rather than 7 days. Inhibition of JNK in seipin-sKO mice corrected the hyperphosphorylated tau at Ser396. The results indicate that neuronal seipin deletion causes hyperphosphorylation and aggregation of tau protein leading to axonal atrophy through reduced PPARγ to enhance GSK3β and Akt/mTOR signaling; systemic seipin deletion-induced insulin resistance causes tau hyperphosphorylation via cascading JNK pathway.
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Affiliation(s)
- Huanxian Chang
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Neurology, First Affiliated Hospital of Nanjing Medical University, Guangzhou Road 300, Nanjing 210029, China
| | - Tingting Di
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Ya Wang
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Xianying Zeng
- Department of Geratology, First Affiliated Hospital of Nanjing Medical University, Guangzhou Road 300, Nanjing 210029, China
| | - Guoxi Li
- Department of Physiology, Nanjing Medical University, Nanjing 211166, China
| | - Qi Wan
- Department of Neurology, First Affiliated Hospital of Nanjing Medical University, Guangzhou Road 300, Nanjing 210029, China
| | - Wenfeng Yu
- Key Laboratory of Endemic and Ethnic Diseases of Education Ministry, Guizhou Medical University, Guian New District, Guizhou 550025, China.
| | - Ling Chen
- State Key Laboratory of Reproductive Medicine, Nanjing Medical University, Nanjing 211166, China; Department of Physiology, Nanjing Medical University, Nanjing 211166, China.
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Li Q, Yu Q, Lin L, Zhang H, Peng M, Jing C, Xu G. Hypothalamic peroxisome proliferator-activated receptor gamma regulates ghrelin production and food intake. Neuropeptides 2018; 69:39-45. [PMID: 29655655 DOI: 10.1016/j.npep.2018.04.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Revised: 04/06/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023]
Abstract
Peroxisome proliferator-activated receptor-γ (PPARγ) regulates fatty acid storage, glucose metabolism, and food intake. Ghrelin, a gastric hormone, provides a hunger signal to the central nervous system to stimulate appetite. However, the effects of PPARγ on ghrelin production are still unclear. In the present study, the effects of PPARγ on ghrelin production were examined in lean- or high-fat diet-induced obese (DIO) C57BL/6J mice and mHypoE-42 cells, a hypothalamic cell line. 3rd intracerebroventricular injection of adenoviral-directed overexpression of PPARγ (Ad-PPARγ) reduced hypothalamic and plasma ghrelin, food intake in both lean C57BL/6J mice and diet-induced obese mice. These changes were associated with a significant increase in mechanistic target of rapamycin complex 1 (mTORC1) activity. Overexpression of PPARγ enhanced mTORC1 signaling and suppressed ghrelin production in cultured mHypoE-42 cells. Our results suggest that hypothalamic PPARγ plays a vital role in ghrelin production and food intake in mice.
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Affiliation(s)
- Qingjie Li
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong 510632, China
| | - Quan Yu
- Central Laboratory, School of Medicine, Jinan University, Guangzhou, China
| | - Li Lin
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong 510632, China
| | - Heng Zhang
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong 510632, China
| | - Miao Peng
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong 510632, China
| | - Chunxia Jing
- Department of Epidemiology, School of Medicine, Jinan University, Guangzhou, China
| | - Geyang Xu
- Department of Physiology, School of Medicine, Jinan University, 601 Huangpu Avenue West, Tianhe District, Guangzhou, Guangdong 510632, China.
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Chistyakov DV, Grabeklis S, Goriainov SV, Chistyakov VV, Sergeeva MG, Reiser G. Astrocytes synthesize primary and cyclopentenone prostaglandins that are negative regulators of their proliferation. Biochem Biophys Res Commun 2018; 500:204-210. [PMID: 29634926 DOI: 10.1016/j.bbrc.2018.04.040] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/04/2018] [Indexed: 01/12/2023]
Abstract
Recently, the modulation of cellular inflammatory responses via endogenous regulators became a major focus of medically relevant investigations. Prostaglandins (PGs) are attractive regulatory molecules, but their synthesis and mechanisms of action in brain cells are still unclear. Astrocytes are involved in manifestation of neuropathology and their proliferation is an important part of astrogliosis, a cellular neuroinflammatory response. The aims of our study were to measure synthesis of PGs by astrocytes, and evaluate their influence on proliferation in combination with addition of inflammatory pathway inhibitors. With UPLC-MS/MS analysis we detected primary PGs (1410 ± 36 pg/mg PGE2, 344 ± 24 PGD2) and cyclopentenone PGs (cyPGs) (87 ± 17 15d-PGJ2, 308 ± 23 PGA2) in the extracellular medium after 24-h lipopolysaccharide (LPS) stimulation of astrocytes. PGs reduced astrocytic proliferation with the following order of potencies (measured as inhibition at 20 μM): most potent 15d-PGJ2 (90%) and PGA2 (80%), > PGD2 (40%) > 15d-PGA2 (20%) > PGE2 (5%), the least potent. However, PGF2α and 2-cyclopenten-1-one, and ciglitazone and rosiglitazone (synthetic agonists of PPARγ) had no effect. Combinations of cyPGs with SC-560 or NS-398 (specific anti-inflammatory inhibitors of cyclooxygenase-1 and -2, respectively) were not effective; while GW9662 (PPARγ antagonist) or MK-741 (inhibitor of multidrug resistance protein-1, MRP1, and CysLT1 receptors) amplified the inhibitory effect of PGA2 and 15d-PGJ2. Although concentrations of individual PGs and cyPGs are low, all of them, as well as primary PGs suppress proliferation. Thus, the effects are potentially additive, and activated PGs synthesis suppresses proliferation in astrocytes.
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Affiliation(s)
- Dmitry V Chistyakov
- A.N. Belozersky Institute of Physico-Chemical-Biology, Moscow State-University, Moscow, Russia; Pirogov Russian National Research Medical University, Moscow, Russia
| | - Sevil Grabeklis
- A.N. Belozersky Institute of Physico-Chemical-Biology, Moscow State-University, Moscow, Russia
| | - Sergei V Goriainov
- Peoples' Friendship University of Russia (RUDN University), Moscow, Russia
| | | | - Marina G Sergeeva
- A.N. Belozersky Institute of Physico-Chemical-Biology, Moscow State-University, Moscow, Russia
| | - Georg Reiser
- Otto-von-Guericke-Universität Magdeburg, Medizinische Fakultät, Institut für Inflammation und Neurodegeneration (Neurobiochemie), Leipziger Straße 44, 39120, Magdeburg, Germany.
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Abstract
OBJECTIVE Adipogenesis determines the number of adipocytes which is increased when individuals become obese. Mitochondria undergo remarkable morphological and functional changes during adipogenesis. PTEN-induced kinase 1 (PINK1) is pivotal to maintain mitochondrial homeostasis in neural cells. The present study aimed at investigating effects of PINK1 on adipogenesis and energy metabolism. METHODS Expression of presenilin associated rhomboid-like protein (PARL), PINK1 and Parkin, as well as the interaction among these proteins was temporally examined during adipogenesis. In addition, the alterations of mitochondrial mass and the energy metabolism were also analyzed. RESULTS Adipogenic process can be dissected into 3 stages according to the participation of PARL-PINK1-Parkin system. (1) When pre-adipocytes are switched to differentiation, f-PINK1 is subjected to PARL cleavage to generate s-PINK1 at the early stage of differentiation (0-4day). Mitochondrial mass is increased for generating ambient energy to meet the demands for cellular remodeling. (2) At the second stage (5-6day), s-PINK1 persistently accumulates in mitochondria and translocates into cytoplasm to mediate Parkin degradation. Mitochondria are fragmented to reduce their mass. (3) At the late stage (7-8day), only residual autophagy activity is remained when excess mitochondria have been eliminated. This mitochondria clearance maintains energy consumption of mature adipocytes at the minimal levels for storing energy. PARL silencing aborts adipogenesis by inhibiting PPARγ expression and the finely-orchestrated events. CONCLUSIONS Our findings reveal the sequential adipogenic events directed by PARL-PINK1-Parkin system, add more evidence supporting the convergence of pathogenesis leading to neurodegenerative and metabolic diseases, and provide substantial information for developing novel therapeutic strategies by manipulating adipogenesis.
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Affiliation(s)
- Ming-Yuh Shiau
- Department of Nursing, College of Medicine & Nursing, Hungkuang University, Taichung 433, Taiwan
| | - Pin-Shen Lee
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Ying-Jyun Huang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Ching-Ping Yang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Chiao-Wan Hsiao
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Kai-Yun Chang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Huan-Wen Chen
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan
| | - Yih-Hsin Chang
- Department of Biotechnology and Laboratory Science in Medicine, National Yang-Ming University, Taipei 112, Taiwan.
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Zhao Y, Huang Y, He J, Li C, Deng W, Ran X, Wang D. Rosiglitazone, a peroxisome proliferator-activated receptor-γ agonist, attenuates airway inflammation by inhibiting the proliferation of effector T cells in a murine model of neutrophilic asthma. Immunol Lett 2013; 157:9-15. [PMID: 24269293 DOI: 10.1016/j.imlet.2013.11.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2013] [Revised: 10/09/2013] [Accepted: 11/04/2013] [Indexed: 02/04/2023]
Abstract
An imbalanced Th17-mediated immune response contributes substantially to neutrophilic asthma. Studies have also demonstrated that peroxisome proliferator-activated receptor-γ (PPARγ) plays a critical role in inflammatory disease. However, the effect of PPARγ on airway inflammation in neutrophilic asthma remains unclear. In the current study, we evaluated the potential therapeutic role of rosiglitazone (RSG) in a new mouse model of asthma characterised by increased neutrophils rather than eosinophils. A co-culture system of DCs with CD4+ naïve T cells was established to evaluate the effects of RSG on T cell differentiation. After challenge with OVA, mice developed the typical pathophysiological features of asthma, including an increased number of neutrophils in the BALF and the up-regulation of IL-17. The numbers of Th17 cells and Th2 cells were also greatly elevated in the lungs. The administration of rosiglitazone reduced the pathophysiological features of asthma and decreased the up-regulated inflammatory mediators and cytokines. Furthermore, the cell viability in the co-culture system was markedly reduced by RSG. T-bet, Gata-3 and RORγt mRNA were down-regulated by RSG. These findings suggest that PPARγ is critical for airway inflammation during neutrophilic asthma, possibly due to its effect on Th cell proliferation and differentiation. These findings suggest that the therapeutic effect of rosiglitazone in neutrophilic asthma is partially due to the role of the PPARγ pathway in regulating T cell proliferation and differentiation.
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Affiliation(s)
- Yan Zhao
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
| | - Yi Huang
- Xinqiao Hospital, Third Military Medical University, Chongqing 400037, PR China.
| | - Jing He
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
| | - Changyi Li
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
| | - Wang Deng
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
| | - Xuemei Ran
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
| | - Daoxin Wang
- The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, PR China.
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