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Parasram K, Zuccato A, Shin M, Willms R, DeVeale B, Foley E, Karpowicz P. The emergence of circadian timekeeping in the intestine. Nat Commun 2024; 15:1788. [PMID: 38413599 PMCID: PMC10899604 DOI: 10.1038/s41467-024-45942-4] [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: 06/12/2023] [Accepted: 02/08/2024] [Indexed: 02/29/2024] Open
Abstract
The circadian clock is a molecular timekeeper, present from cyanobacteria to mammals, that coordinates internal physiology with the external environment. The clock has a 24-h period however development proceeds with its own timing, raising the question of how these interact. Using the intestine of Drosophila melanogaster as a model for organ development, we track how and when the circadian clock emerges in specific cell types. We find that the circadian clock begins abruptly in the adult intestine and gradually synchronizes to the environment after intestinal development is complete. This delayed start occurs because individual cells at earlier stages lack the complete circadian clock gene network. As the intestine develops, the circadian clock is first consolidated in intestinal stem cells with changes in Ecdysone and Hnf4 signalling influencing the transcriptional activity of Clk/cyc to drive the expression of tim, Pdp1, and vri. In the mature intestine, stem cell lineage commitment transiently disrupts clock activity in differentiating progeny, mirroring early developmental clock-less transitions. Our data show that clock function and differentiation are incompatible and provide a paradigm for studying circadian clocks in development and stem cell lineages.
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Affiliation(s)
- Kathyani Parasram
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, N9B 3P4, Canada
| | - Amy Zuccato
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, N9B 3P4, Canada
| | - Minjeong Shin
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Reegan Willms
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Brian DeVeale
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, N9B 3P4, Canada
| | - Edan Foley
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, AB, T6G 2E1, Canada
| | - Phillip Karpowicz
- Department of Biomedical Sciences, University of Windsor, Windsor, ON, N9B 3P4, Canada.
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2
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Yujra VQ, Silveira EJDD, Ribeiro DA, Castilho RM, Squarize CH. Clock gene Per2 modulates epidermal tissue repair in vivo. J Cell Biochem 2024; 125:e30513. [PMID: 38229522 DOI: 10.1002/jcb.30513] [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: 08/28/2023] [Revised: 11/18/2023] [Accepted: 12/05/2023] [Indexed: 01/18/2024]
Abstract
Wound healing can be influenced by genes that control the circadian cycle, including Per2 and BMAL1, which coordinate the functions of several organs, including the skin. The aim of the study was to evaluate the role of PER2 during experimental skin wound healing. Two groups (control and Per2-KO), consisting of 14 male mice each, were anesthetized by inhalation, and two 6 mm wounds were created on their dorsal skin using a punch biopsy. A silicone ring was sutured around the wound perimeter to restrict contraction. The wound healing process was clinically measured daily (closure index) until complete wound repair. On Day 6, histomorphometric analysis was performed using the length and thickness of the epithelial migration tongue, in addition to counting vessels underlying the lesion by immunofluorescence assay and maturation of collagen fibers through picrosirius staining. Bromodeoxyuridine (BrdU) incorporation and quantification were performed using the subcutaneous injection technique 2 h before euthanasia and through immunohistochemical analysis of the proliferative index. In addition, the qualitative analysis of myofibroblasts and periostin distribution in connective tissue was performed by immunofluorescence. Statistically significant differences were observed in the healing time between the experimental groups (means: 15.5 days for control mice and 13.5 days for Per2-KO; p = 0.001). The accelerated healing observed in the Per2-KO group (p < 0.05) was accompanied by statistical differences in wound diameter and length of the migrating epithelial tongue (p = 0.01) compared to the control group. Regarding BrdU immunoreactivity, higher expression was observed in the intact epithelium of Per2-KO animals (p = 0.01), and this difference compared to control was also present, to a lesser extent, at the wound site (p = 0.03). Immunofluorescence in the connective tissue underlying the wound showed a higher angiogenic potential in the Per2-KO group in the intact tissue area and the wound region (p < 0.01), where increased expression of myofibroblasts was also observed. Qualitative analysis revealed the distribution of periostin protein and collagen fibers in the connective tissue underlying the wound, with greater organization and maturation during the analyzed period. Our research showed that the absence of the Per2 gene positively impacts the healing time of the skin in vivo. This acceleration depends on the increase of epithelial proliferative and angiogenic capacity of cells carrying the Per2 deletion.
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Affiliation(s)
- Veronica Quispe Yujra
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan (UM), Ann Arbor, Michigan, USA
- Department of Biosciences, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Ericka Janine Dantas da Silveira
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan (UM), Ann Arbor, Michigan, USA
- Odontology Sciences Postgraduate Program, Dentistry Department, Federal University of Rio Grande do Norte (UFRN), Natal, Brazil
| | - Daniel Araki Ribeiro
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan (UM), Ann Arbor, Michigan, USA
- Department of Biosciences, Federal University of São Paulo (UNIFESP), São Paulo, Brazil
| | - Rogerio Moraes Castilho
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan (UM), Ann Arbor, Michigan, USA
| | - Cristiane Helena Squarize
- Laboratory of Epithelial Biology, Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan (UM), Ann Arbor, Michigan, USA
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3
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Li W, Xiong X, Kiperman T, Ma K. Transcription Repression of CRY2 via PER2 Interaction Promotes Adipogenesis. Mol Cell Biol 2023; 43:500-514. [PMID: 37724597 PMCID: PMC10569361 DOI: 10.1080/10985549.2023.2253710] [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: 08/25/2023] [Indexed: 09/21/2023] Open
Abstract
The circadian clock is driven by a transcriptional-translational feedback loop, and cryptochrome 2 (CRY2) represses CLOCK/BMAL1-induced transcription activation. Despite the established role of clock in adipogenic regulation, whether the CRY2 repressor activity functions in adipocyte biology remains unclear. Here we identify a critical cysteine residue of CRY2 that mediates interaction with Period 2 (PER2). We further demonstrate that this mechanism is required for repressing circadian clock-controlled Wnt signaling to promote adipogenesis. CRY2 protein is enriched in white adipose depots and robustly induced by adipogenic differentiation. Via site-directed mutagenesis, we identified that a conserved CRY2 cysteine at 432 within the loop interfacing with PER2 mediates heterodimer complex formation that confers transcription repression. C432 mutation disrupted PER2 association without affecting BMAL1 binding, leading to loss of repression of clock transcription activation. In preadipocytes, whereas CRY2 enhanced adipocyte differentiation, the repression-defective C432 mutant suppressed this process. Furthermore, silencing of CRY2 attenuated, while stabilization of CRY2 by KL001 markedly augmented adipocyte maturation. Mechanistically, we show that transcriptional repression of Wnt pathway components underlies CRY2 modulation of adipogenesis. Collectively, our findings elucidate a CRY2-mediated repression mechanism that promotes adipocyte development, and implicate its potential as a clock intervention target for obesity.
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Affiliation(s)
- Weini Li
- Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, USA
| | - Xuekai Xiong
- Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, USA
| | - Tali Kiperman
- Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, USA
| | - Ke Ma
- Department of Diabetes Complications & Metabolism, Arthur Riggs Diabetes & Metabolism Research Institute, Beckman Research Institute of City of Hope, Duarte, California, USA
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4
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Azzi A, Tao Z, Sun Y, Erb H, Guarino C, Wu X. The circadian clock protein Cryptochrome 1 is a direct target and feedback regulator of the Hippo pathway. iScience 2023; 26:107449. [PMID: 37593458 PMCID: PMC10428131 DOI: 10.1016/j.isci.2023.107449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 06/19/2023] [Accepted: 07/17/2023] [Indexed: 08/19/2023] Open
Abstract
Circadian clock controls daily behavior and physiology. The activity of various signaling pathways affects clock gene expression. Here, we show that the core circadian clock gene CRY1 is a direct target of the Hippo pathway effector YAP. YAP binds to TEADs and occupies the proximal promoter regions of CRY1, positively regulating its transcription. Interestingly, we further identified that CRY1 acts in a feedback loop to fine-tune Hippo pathway activation by modulating the expression of YAP and MOB1. Indeed, loss of CRY1 results in enhanced YAP activation. Consistently, we found that YAP levels and activity control clock gene expression and oscillation in synchronized cells. Furthermore, in breast cancer cells, CRY1 downregulation causes YAP/TAZ hyperactivation and enhanced DNA damage. Together, our findings provide a direct mechanistic link between the Hippo pathway and the circadian clock, where CRY1 and Hippo components form an orchestrated signaling network that influences cell growth and circadian rhythm.
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Affiliation(s)
- Abdelhalim Azzi
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Zhipeng Tao
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Yang Sun
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Hannah Erb
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Carla Guarino
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
| | - Xu Wu
- Cutaneous Biology Research Center, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA
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Xiong X, Kiperman T, Li W, Dhawan S, Lee J, Yechoor V, Ma K. The Clock-modulatory Activity of Nobiletin Suppresses Adipogenesis Via Wnt Signaling. Endocrinology 2023; 164:bqad096. [PMID: 37327385 PMCID: PMC10373950 DOI: 10.1210/endocr/bqad096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Revised: 06/09/2023] [Accepted: 06/13/2023] [Indexed: 06/18/2023]
Abstract
The circadian clock machinery exerts transcriptional control to modulate adipogenesis and its disruption leads to the development of obesity. Here, we report that Nobiletin, a circadian clock amplitude-enhancing molecule, displays antiadipogenic properties via activation of Wnt signaling pathway that is dependent on its clock modulation. Nobiletin augmented clock oscillatory amplitude with period lengthening in the adipogenic mesenchymal precursor cells and preadipocytes, accompanied by an induction of Bmal1 and clock components within the negative feedback arm. Consistent with its clock-modulatory activity, Nobiletin strongly inhibited the lineage commitment and terminal differentiation of adipogenic progenitors. Mechanistically, we show that Nobiletin induced the reactivation of Wnt signaling during adipogenesis via transcriptional up-regulation of key components within this pathway. Furthermore, Nobiletin administration in mice markedly reduced adipocyte hypertrophy, leading to a significant loss of fat mass and reduction of body weight. Last, Nobiletin inhibited the differentiation of primary preadipocytes, and this effect was dependent on a functional clock regulation. Collectively, our findings uncover a novel activity of Nobiletin in suppressing adipocyte development in a clock-dependent manner, implicating its potential application in countering obesity and associated metabolic consequences.
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Affiliation(s)
- Xuekai Xiong
- Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Tali Kiperman
- Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Weini Li
- Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
| | - Jeongkyung Lee
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Vijay Yechoor
- Diabetes and Beta Cell Biology Center, Division of Endocrinology, Diabetes and Metabolism, Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15213, USA
| | - Ke Ma
- Department of Diabetes Complications and Metabolism, Beckman Research Institute of City of Hope, Duarte, CA 91010, USA
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Abstract
The circadian clock plays an essential role in coordinating feeding and metabolic rhythms with the light/dark cycle. Disruption of clocks is associated with increased adiposity and metabolic disorders, whereas aligning feeding time with cell-autonomous rhythms in metabolism improves health. Here, we provide a comprehensive overview of recent literature in adipose tissue biology as well as our understanding of molecular mechanisms underlying the circadian regulation of transcription, metabolism, and inflammation in adipose tissue. We highlight recent efforts to uncover the mechanistic links between clocks and adipocyte metabolism, as well as its application to dietary and behavioral interventions to improve health and mitigate obesity.
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Affiliation(s)
- Chelsea Hepler
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Joseph Bass
- Department of Medicine, Division of Endocrinology, Metabolism, and Molecular Medicine, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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7
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Šmon J, Kočar E, Pintar T, Dolenc-Grošelj L, Rozman D. Is obstructive sleep apnea a circadian rhythm disorder? J Sleep Res 2023:e13875. [PMID: 36922163 DOI: 10.1111/jsr.13875] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2022] [Revised: 02/06/2023] [Accepted: 02/28/2023] [Indexed: 03/17/2023]
Abstract
Obstructive sleep apnea is the most common sleep-related breathing disorder worldwide and remains underdiagnosed. Its multiple associated comorbidities contribute to a decreased quality of life and work performance as well as an increased risk of death. Standard treatment seems to have limited effects on cardiovascular and metabolic aspects of the disease, emphasising the need for early diagnosis and additional therapeutic approaches. Recent evidence suggests that the dysregulation of circadian rhythms, processes with endogenous rhythmicity that are adjusted to the environment through various cues, is involved in the pathogenesis of comorbidities. In patients with obstructive sleep apnea, altered circadian gene expression patterns have been demonstrated. Obstructive respiratory events may promote circadian dysregulation through the effects of sleep disturbance and intermittent hypoxia, with subsequent inflammation and disruption of neural and hormonal homeostasis. In this review, current knowledge on obstructive sleep apnea, circadian rhythm regulation, and circadian rhythm sleep disorders is summarised. Studies that connect obstructive sleep apnea to circadian rhythm abnormalities are critically evaluated. Furthermore, pathogenetic mechanisms that may underlie this association, most notably hypoxia signalling, are presented. A bidirectional relationship between obstructive sleep apnea and circadian rhythm dysregulation is proposed. Approaching obstructive sleep apnea as a circadian rhythm disorder may prove beneficial for the development of new, personalised diagnostic, therapeutic and prognostic tools. However, further studies are needed before the clinical approach to obstructive sleep apnea includes targeting the circadian system.
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Affiliation(s)
- Julija Šmon
- Institute of Clinical Neurophysiology, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Kočar
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Tadeja Pintar
- Department of Abdominal Surgery, University Medical Centre Ljubljana, Ljubljana, Slovenia
| | - Leja Dolenc-Grošelj
- Institute of Clinical Neurophysiology, University Medical Centre Ljubljana, Ljubljana, Slovenia.,Department of Neurology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Damjana Rozman
- Centre for Functional Genomics and Bio-Chips, Institute of Biochemistry and Molecular Genetics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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8
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Li W, Xiong X, Kiperman T, Ma K. Transcription repression of Cry2 via Per2 interaction promotes adipogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.12.532323. [PMID: 36993226 PMCID: PMC10054956 DOI: 10.1101/2023.03.12.532323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The circadian clock is driven by a transcriptional-translational feedback loop, and Cryptochrome 2 (Cry2) represses CLOCK/Bmal1-induced transcription activation. Despite the established role of clock in adipogenic regulation, whether the Cry2 repressor activity functions in adipocyte biology remains unclear. Here we identify a critical cysteine residue of Cry2 that mediates interaction with Per2, and demonstrate that this mechanism is required for clock transcriptional repression that inhibits Wnt signaling to promote adipogenesis. Cry2 protein is enriched in white adipose depots and was robustly induced by adipocyte differentiation. Via site-directed mutagenesis, we identified that a conserved Cry2 Cysteine at 432 within the loop interfacing with Per2 mediates heterodimer complex formation that confers transcription repression. C432 mutation disrupted Per2 association without affecting Bmal1 binding, leading to loss of repression of clock transcription activation. In preadipocytes, whereas Cry2 enhanced adipogenic differentiation, the repression-defective C432 mutant suppressed this process. Furthermore, silencing of Cry2 attenuated, while stabilization of Cry2 by KL001 markedly augmented adipocyte maturation. Mechanistically, we show that transcriptional repression of Wnt pathway components underlies Cry2 modulation of adipogenesis. Collectively, our findings elucidate a Cry2-mediated repression mechanism that promotes adipocyte development, and implicate its potential as a clock intervention target for obesity.
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9
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Xiong X, Kiperman T, Li W, Dhawan S, Lee J, Yechoor V, Ma K. The clock-modulatory activity of Nobiletin suppresses adipogenesis via Wnt signaling. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.07.527587. [PMID: 36798247 PMCID: PMC9934622 DOI: 10.1101/2023.02.07.527587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
The circadian clock machinery exerts transcriptional control to modulate adipogenesis and its disruption leads to the development of obesity. Here we report that Nobiletin, a clock amplitude-enhancing molecule, displays anti-adipogenic properties via activating a clock-controlled Wnt signaling pathway that suppresses adipocyte differentiation. Nobiletin augmented clock oscillation with period length shortening in the adipogenic mesenchymal precursor cells and preadipocytes, accompanied by an induction of Bmal1 and core clock components. Consistent with its circadian clock-modulatory activity, Nobiletin inhibited the lineage commitment and terminal differentiation of adipogenic progenitors. Mechanistically, we show that Nobiletin induced the re-activation of Wnt signaling during adipogenic differentiation via transcriptional up-regulation of key components of this pathway. Furthermore, Nobiletin administration in mice markedly reduced adipocyte hypertrophy, leading to a significant loss of fat mass and body weight reduction. Lastly, Nobiletin inhibited the maturation of primary preadipocytes and this effect was dependent on a functional clock regulation. Collectively, our findings uncover a novel activity of Nobiletin in suppressing adipocyte development, implicating its potential therapeutic application in countering obesity and its associated metabolic consequences.
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10
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Catalano F, De Vito F, Cassano V, Fiorentino TV, Sciacqua A, Hribal ML. Circadian Clock Desynchronization and Insulin Resistance. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 20:29. [PMID: 36612350 PMCID: PMC9819930 DOI: 10.3390/ijerph20010029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 12/09/2022] [Accepted: 12/16/2022] [Indexed: 06/17/2023]
Abstract
The circadian rhythm regulates biological processes that occur within 24 h in living organisms. It plays a fundamental role in maintaining biological functions and responds to several inputs, including food intake, light/dark cycle, sleep/wake cycle, and physical activity. The circadian timing system comprises a central clock located in the suprachiasmatic nucleus (SCN) and tissue-specific clocks in peripheral tissues. Several studies show that the desynchronization of central and peripheral clocks is associated with an increased incidence of insulin resistance (IR) and related diseases. In this review, we discuss the current knowledge of molecular and cellular mechanisms underlying the impact of circadian clock dysregulation on insulin action. We focus our attention on two possible mediators of this interaction: the phosphatases belonging to the pleckstrin homology leucine-rich repeat protein phosphatase family (PHLPP) family and the deacetylase Sirtuin1. We believe that literature data, herein summarized, suggest that a thorough change of life habits, with the return to synchronized food intake, physical activity, and rest, would doubtless halt the vicious cycle linking IR to dysregulated circadian rhythms. However, since such a comprehensive change may be incompatible with the demand of modern society, clarifying the pathways involved may, nonetheless, contribute to the identification of therapeutic targets that may be exploited to cure or prevent IR-related diseases.
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Bahrami-Nejad Z, Zhang ZB, Tholen S, Sharma S, Rabiee A, Zhao ML, Kraemer FB, Teruel MN. Early enforcement of cell identity by a functional component of the terminally differentiated state. PLoS Biol 2022; 20:e3001900. [PMID: 36469503 PMCID: PMC9721491 DOI: 10.1371/journal.pbio.3001900] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/02/2022] [Indexed: 12/12/2022] Open
Abstract
How progenitor cells can attain a distinct differentiated cell identity is a challenging problem given the fluctuating signaling environment in which cells exist and that critical transcription factors are often not unique to a differentiation process. Here, we test the hypothesis that a unique differentiated cell identity can result from a core component of the differentiated state doubling up as a signaling protein that also drives differentiation. Using live single-cell imaging in the adipocyte differentiation system, we show that progenitor fat cells (preadipocytes) can only commit to terminally differentiate after up-regulating FABP4, a lipid buffer that is highly enriched in mature adipocytes. Upon induction of adipogenesis in mouse preadipocyte cells, we show that after a long delay, cells first abruptly start to engage a positive feedback between CEBPA and PPARG before then engaging, after a second delay, a positive feedback between FABP4 and PPARG. These sequential positive feedbacks both need to engage in order to drive PPARG levels past the threshold for irreversible differentiation. In the last step before commitment, PPARG transcriptionally increases FABP4 expression while fatty acid-loaded FABP4 increases PPARG activity. Together, our study suggests a control principle for robust cell identity whereby a core component of the differentiated state also promotes differentiation from its own progenitor state.
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Affiliation(s)
- Zahra Bahrami-Nejad
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | - Zhi-Bo Zhang
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
- Department of Biochemistry and the Drukier Institute for Children’s Health, Weill Cornell Medical College of Cornell University, New York, New York, United States of America
| | - Stefan Tholen
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | - Sanjeev Sharma
- Department of Biochemistry and the Drukier Institute for Children’s Health, Weill Cornell Medical College of Cornell University, New York, New York, United States of America
| | - Atefeh Rabiee
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
- Department of Physiology and Pharmacology, Thomas J. Long School of Pharmacy and Health Sciences, University of the Pacific, Stockton, California, United States of America
| | - Michael L. Zhao
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
| | - Fredric B. Kraemer
- Department of Medicine/Division of Endocrinology, Stanford University, Stanford, California, United States of America
- VA Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Mary N. Teruel
- Department of Chemical and Systems Biology, Stanford University, Stanford, California, United States of America
- Department of Biochemistry and the Drukier Institute for Children’s Health, Weill Cornell Medical College of Cornell University, New York, New York, United States of America
- Department of Bioengineering, Stanford University School of Medicine, Stanford, California, United States of America
- Weill Center for Metabolic Health, Division of Endocrinology, Diabetes & Metabolism, Joan and Sanford I. Weill Department of Medicine, Weill Cornell Medical College of Cornell University, New York, New York, United States of America
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