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Yin X, Yan Y, Li J, Cao Z, Shen S, Chang Q, Zhao Y, Wang X, Wang P. Nuclear receptors for epidermal lipid barrier: Advances in mechanisms and applications. Exp Dermatol 2024; 33:e15107. [PMID: 38840418 DOI: 10.1111/exd.15107] [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: 10/18/2023] [Revised: 04/20/2024] [Accepted: 05/19/2024] [Indexed: 06/07/2024]
Abstract
The skin plays an essential role in preventing the entry of external environmental threats and the loss of internal substances, depending on the epidermal permeability barrier. Nuclear receptors (NRs), present in various tissues and organs including full-thickness skin, have been demonstrated to exert significant effects on the epidermal lipid barrier. Formation of the lipid lamellar membrane and the normal proliferation and differentiation of keratinocytes (KCs) are crucial for the development of the epidermal permeability barrier and is regulated by specific NRs such as PPAR, LXR, VDR, RAR/RXR, AHR, PXR and FXR. These receptors play a key role in regulating KC differentiation and the entire process of epidermal lipid synthesis, processing and secretion. Lipids derived from sebaceous glands are influenced by NRs as well and participate in regulation of the epidermal lipid barrier. Furthermore, intricate interplay exists between these receptors. Disturbance of barrier function leads to a range of diseases, including psoriasis, atopic dermatitis and acne. Targeting these NRs with agonists or antagonists modulate pathways involved in lipid synthesis and cell differentiation, suggesting potential therapeutic approaches for dermatosis associated with barrier damage. This review focuses on the regulatory role of NRs in the maintenance and processing of the epidermal lipid barrier through their effects on skin lipid synthesis and KC differentiation, providing novel insights for drug targets to facilitate precision medicine strategies.
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Affiliation(s)
- Xidie Yin
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yu Yan
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Jiandan Li
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Zhi Cao
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Shuzhan Shen
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Qihang Chang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Yiting Zhao
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Xiuli Wang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
| | - Peiru Wang
- Institute of Photomedicine, Shanghai Skin Disease Hospital, School of Medicine, Tongji University, Shanghai, China
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Jain GK, Raina V, Grover R, Sharma J, Warsi MH, Aggarwal G, Kesharwani P. Revisiting the significance of nano-vitamin D for food fortification and therapeutic application. Drug Dev Ind Pharm 2024; 50:89-101. [PMID: 38175566 DOI: 10.1080/03639045.2023.2301478] [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: 01/03/2023] [Accepted: 12/29/2023] [Indexed: 01/05/2024]
Abstract
OBJECTIVE Vitamin D (a prohormone) is an important micronutrient required by the body for skeletal homeostasis and a range of non-skeletal actions. Calcitriol, the active form of vitamin D, regulates a variety of cellular and metabolic processes through both genomic and nongenomic pathways. Often prescribed for treating rickets and osteoporosis, vitamin D deficiency can exacerbate various other medical conditions. SIGNIFICANCE, METHODS, AND RESULTS Despite its multifunctional uses, the sensitivity of vitamin D makes formulating an efficient drug delivery system a challenging task, which is further complicated by its poor aqueous solubility. Enhancing the oral absorption of vitamin D is vital in utilizing its full efficacy. Recent developments in encapsulation and nanotechnology have shown promising results in overcoming these constraints. CONCLUSION This review thus offers an insight to adequately comprehend the mechanistic pharmacology of vitamin D, its pathophysiological role, and justification of its medical indications, along with the benefits of utilizing nanotechnology for vitamin D delivery.
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Affiliation(s)
- Gaurav K Jain
- Center for Advanced Formulation Technology (CAFT), Delhi Pharmaceutical Science and Research University (DPSRU), New Delhi, India
| | - Vidya Raina
- Center for Advanced Formulation Technology (CAFT), Delhi Pharmaceutical Science and Research University (DPSRU), New Delhi, India
| | - Rakshita Grover
- Center for Advanced Formulation Technology (CAFT), Delhi Pharmaceutical Science and Research University (DPSRU), New Delhi, India
| | - Jagriti Sharma
- Center for Advanced Formulation Technology (CAFT), Delhi Pharmaceutical Science and Research University (DPSRU), New Delhi, India
| | - Musarrat Husain Warsi
- Department of Pharmaceutics and Industrial Pharmacy, College of Pharmacy, Taif University, Taif, Saudi Arabia
| | - Geeta Aggarwal
- Center for Advanced Formulation Technology (CAFT), Delhi Pharmaceutical Science and Research University (DPSRU), New Delhi, India
| | - Prashant Kesharwani
- Department of Pharmaceutics, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi, India
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3
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Thaler R, Yoshizaki K, Nguyen T, Fukumoto S, Den Besten P, Bikle DD, Oda Y. Mediator 1 ablation induces enamel-to-hair lineage conversion in mice through enhancer dynamics. Commun Biol 2023; 6:766. [PMID: 37479880 PMCID: PMC10362024 DOI: 10.1038/s42003-023-05105-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Accepted: 07/06/2023] [Indexed: 07/23/2023] Open
Abstract
Postnatal cell fate is postulated to be primarily determined by the local tissue microenvironment. Here, we find that Mediator 1 (Med1) dependent epigenetic mechanisms dictate tissue-specific lineage commitment and progression of dental epithelia. Deletion of Med1, a key component of the Mediator complex linking enhancer activities to gene transcription, provokes a tissue extrinsic lineage shift, causing hair generation in incisors. Med1 deficiency gives rise to unusual hair growth via primitive cellular aggregates. Mechanistically, we find that MED1 establishes super-enhancers that control enamel lineage transcription factors in dental stem cells and their progenies. However, Med1 deficiency reshapes the enhancer landscape and causes a switch from the dental transcriptional program towards hair and epidermis on incisors in vivo, and in dental epithelial stem cells in vitro. Med1 loss also provokes an increase in the number and size of enhancers. Interestingly, control dental epithelia already exhibit enhancers for hair and epidermal key transcription factors; these transform into super-enhancers upon Med1 loss suggesting that these epigenetic mechanisms cause the shift towards epidermal and hair lineages. Thus, we propose a role for Med1 in safeguarding lineage specific enhancers, highlight the central role of enhancer accessibility in lineage reprogramming and provide insights into ectodermal regeneration.
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Affiliation(s)
- Roman Thaler
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, MN, USA
- Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, USA
| | - Keigo Yoshizaki
- Section of Orthodontics and Dentofacial Orthopedics, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
| | - Thai Nguyen
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA
| | - Satoshi Fukumoto
- Section of Pediatric Dentistry, Division of Oral Health, Growth and Development, Kyushu University Faculty of Dental Science, Fukuoka, Japan
- Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai, Japan
| | - Pamela Den Besten
- Department of Dentistry, University of California San Francisco, San Francisco, CA, USA
| | - Daniel D Bikle
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA
| | - Yuko Oda
- Departments of Medicine and Endocrinology, University of California San Francisco and San Francisco Veterans Affairs Health Center, San Francisco, CA, USA.
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Wong CT, Ona K, Oh DH. Regulation of XPC Binding Dynamics and Global Nucleotide Excision Repair by p63 and Vitamin D Receptor. J Phys Chem B 2023; 127:2121-2127. [PMID: 36877866 DOI: 10.1021/acs.jpcb.2c07257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2023]
Abstract
p63 and the vitamin D receptor (VDR) play important roles in epidermal development and differentiation, but their roles and relationship in the response to ultraviolet (UV) radiation are less clear. Using TERT-immortalized human keratinocytes expressing shRNA targeting p63 in concert with exogenously applied siRNA targeting VDR, we assessed p63 and VDR's separate and combined effect on nucleotide excision repair (NER) of UV-induced 6-4 photoproducts (6-4PP). Knockdown of p63 reduced VDR and XPC expression relative to nontargeting controls, while knockdown of VDR had no effect on p63 and XPC protein expression, though alone it modestly reduced XPC mRNA. Upon UV irradiation through filters with 3 μm pores to create spatially discrete spots of DNA damage, keratinocytes depleted of p63 or VDR exhibited slower removal of 6-4PP than control cells over the first 30 min. Costaining of control cells with antibodies to XPC revealed that XPC accumulated at DNA damage foci, peaking within 15 min and gradually fading over 90 min as NER proceeded. In either p63- or VDR-depleted keratinocytes, XPC overaccumulated at spots of DNA damage so that 50% more XPC was retained at 15 min and 100% more XPC was retained at 30 min than in control cells, suggesting dissociation of XPC after binding was also delayed. Concurrent knockdown of VDR and p63 resulted in similar impairment of 6-4PP repair and XPC overaccumulation but even slower release of XPC from DNA damage sites such that 200% more XPC was retained relative to controls at 30 min post-UV. These results suggest that VDR accounts for some of p63's effects in delaying 6-4PP repair associated with overaccumulation and slower dissociation of XPC, though p63's regulation of basal XPC expression appears to be VDR-independent. The results are consistent with a model where XPC dissociation is an important step during NER and that failure to do so may inhibit subsequent repair steps. This work further links two important regulators of epidermal growth and differentiation to the DNA repair response to UV.
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Affiliation(s)
- Christian T Wong
- Dermatology Research Unit, San Francisco VA Health Care System, San Francisco, California 94121, United States
- Department of Dermatology University of California San Francisco, San Francisco, California 94115, United States
| | - Katherine Ona
- Dermatology Research Unit, San Francisco VA Health Care System, San Francisco, California 94121, United States
- Department of Dermatology University of California San Francisco, San Francisco, California 94115, United States
| | - Dennis H Oh
- Dermatology Research Unit, San Francisco VA Health Care System, San Francisco, California 94121, United States
- Department of Dermatology University of California San Francisco, San Francisco, California 94115, United States
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Bikle DD. Role of vitamin D and calcium signaling in epidermal wound healing. J Endocrinol Invest 2023; 46:205-212. [PMID: 35963983 PMCID: PMC9859773 DOI: 10.1007/s40618-022-01893-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 07/31/2022] [Indexed: 01/25/2023]
Abstract
PURPOSE This review will discuss the role of vitamin D and calcium signaling in the epidermal wound response with particular focus on the stem cells of the epidermis and hair follicle that contribute to the wounding response. METHODS Selected publications relevant to the mechanisms of wound healing in general and the roles of calcium and vitamin D in wound healing in particular were reviewed. RESULTS Following wounding the stem cells of the hair follicle and interfollicular epidermis are activated to proliferate and migrate to the wound where they take on an epidermal fate to re-epithelialize the wound and regenerate the epidermis. The vitamin D and calcium sensing receptors (VDR and CaSR, respectively) are expressed in the stem cells of the hair follicle and epidermis where they play a critical role in enabling the stem cells to respond to wounding. Deletion of Vdr and/or Casr from these cells delays wound healing. The VDR is regulated by co-regulators such as the Med 1 complex and other transcription factors such as Ctnnb (beta-catenin) and p63. The formation of the Cdh1/Ctnn (E-cadherin/catenin) complex jointly stimulated by vitamin D and calcium plays a critical role in the activation, migration, and re-epithelialization processes. CONCLUSION Vitamin D and calcium signaling are critical for the ability of epidermal and hair follicle stem cells to respond to wounding. Vitamin D deficiency with the accompanying decrease in calcium signaling can result in delayed and/or chronic wounds, a major cause of morbidity, loss of productivity, and medical expense.
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Affiliation(s)
- D D Bikle
- Department of Medicine and Dermatology, University of California San Francisco, San Francisco VA Medical Center, San Francisco, USA.
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6
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Bell RAV, Al-Khalaf MH, Brunette S, Alsowaida D, Chu A, Bandukwala H, Dechant G, Apostolova G, Dilworth FJ, Megeney LA. Chromatin Reorganization during Myoblast Differentiation Involves the Caspase-Dependent Removal of SATB2. Cells 2022; 11:cells11060966. [PMID: 35326417 PMCID: PMC8946544 DOI: 10.3390/cells11060966] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Revised: 02/27/2022] [Accepted: 03/09/2022] [Indexed: 11/17/2022] Open
Abstract
The induction of lineage-specific gene programs are strongly influenced by alterations in local chromatin architecture. However, key players that impact this genome reorganization remain largely unknown. Here, we report that the removal of the special AT-rich binding protein 2 (SATB2), a nuclear protein known to bind matrix attachment regions, is a key event in initiating myogenic differentiation. The deletion of myoblast SATB2 in vitro initiates chromatin remodeling and accelerates differentiation, which is dependent on the caspase 7-mediated cleavage of SATB2. A genome-wide analysis indicates that SATB2 binding within chromatin loops and near anchor points influences both loop and sub-TAD domain formation. Consequently, the chromatin changes that occur with the removal of SATB2 lead to the derepression of differentiation-inducing factors while also limiting the expression of genes that inhibit this cell fate change. Taken together, this study demonstrates that the temporal control of the SATB2 protein is critical in shaping the chromatin environment and coordinating the myogenic differentiation program.
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Affiliation(s)
- Ryan A. V. Bell
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Mohammad H. Al-Khalaf
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- University of Ottawa Heart Institute, Ottawa, ON K1Y 4W7, Canada
| | - Steve Brunette
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
| | - Dalal Alsowaida
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Alphonse Chu
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Hina Bandukwala
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
| | - Georg Dechant
- Institute of Neuroscience, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (G.D.); (G.A.)
| | - Galina Apostolova
- Institute of Neuroscience, Medical University of Innsbruck, A-6020 Innsbruck, Austria; (G.D.); (G.A.)
| | - F. Jeffrey Dilworth
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Lynn A. Megeney
- Regenerative Medicine Program, Sprott Center for Stem Cell Research, Ottawa Hospital Research Institute, The Ottawa Hospital, Ottawa, ON K1H 8L6, Canada; (R.A.V.B.); (M.H.A.-K.); (S.B.); (D.A.); (A.C.); (H.B.); (F.J.D.)
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
- Correspondence:
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Roliński M, Montaldo NP, Aksu ME, Fordyce Martin S, Brambilla A, Kunath N, Johansen J, Erlandsen S, Liabbak NB, Rian K, Bjørås M, Sætrom P, van Loon B. Loss of Mediator complex subunit 13 (MED13) promotes resistance to alkylation through cyclin D1 upregulation. Nucleic Acids Res 2021; 49:1470-1484. [PMID: 33444446 PMCID: PMC7897519 DOI: 10.1093/nar/gkaa1289] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 12/22/2020] [Accepted: 12/30/2020] [Indexed: 12/19/2022] Open
Abstract
Alkylating drugs are among the most often used chemotherapeutics. While cancer cells frequently develop resistance to alkylation treatments, detailed understanding of mechanisms that lead to the resistance is limited. Here, by using genome-wide CRISPR-Cas9 based screen, we identify transcriptional Mediator complex subunit 13 (MED13) as a novel modulator of alkylation response. The alkylation exposure causes significant MED13 downregulation, while complete loss of MED13 results in reduced apoptosis and resistance to alkylating agents. Transcriptome analysis identified cyclin D1 (CCND1) as one of the highly overexpressed genes in MED13 knock-out (KO) cells, characterized by shorter G1 phase. MED13 is able to bind to CCND1 regulatory elements thus influencing the expression. The resistance of MED13 KO cells is directly dependent on the cyclin D1 overexpression, and its down-regulation is sufficient to re-sensitize the cells to alkylating agents. We further demonstrate the therapeutic potential of MED13-mediated response, by applying combinatory treatment with CDK8/19 inhibitor Senexin A. Importantly, the treatment with Senexin A stabilizes MED13, and in combination with alkylating agents significantly reduces viability of cancer cells. In summary, our findings identify novel alkylation stress response mechanism dependent on MED13 and cyclin D1 that can serve as basis for development of innovative therapeutic strategies.
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Affiliation(s)
- Miłosz Roliński
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Nicola Pietro Montaldo
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Merdane Ezgi Aksu
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Sarah L Fordyce Martin
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Alessandro Brambilla
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Nicolas Kunath
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Jostein Johansen
- Bioinformatics core facility - BioCore; Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Sten Even Erlandsen
- Genomics core facility, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Nina-Beate Liabbak
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Kristin Rian
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
| | - Magnar Bjørås
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
- Department of Microbiology, Oslo University Hospital, 0027 Oslo, Norway; Department of Medical Biochemistry, Oslo University Hospital and University of Oslo, 0372 Oslo, Norway
| | - Pål Sætrom
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
- Bioinformatics core facility - BioCore; Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- K.G. Jebsen Center for Genetic Epidemiology, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
- Department of Computer Science, Faculty of Information Technology and Electrical Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway
| | - Barbara van Loon
- Department of Clinical and Molecular Medicine, Norwegian University of Science and Technology, 7049 Trondheim, Norway
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Oda Y, Nguyen T, Hata A, Meyer MB, Pike JW, Bikle DD. Deletion of Mediator 1 suppresses TGFβ signaling leading to changes in epidermal lineages and regeneration. PLoS One 2020; 15:e0238076. [PMID: 32857768 PMCID: PMC7455038 DOI: 10.1371/journal.pone.0238076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Accepted: 08/08/2020] [Indexed: 12/27/2022] Open
Abstract
Epidermal lineages and injury induced regeneration are controlled by transcriptional programs coordinating cellular signaling and epigenetic regulators, but the mechanism remains unclear. Previous studies showed that conditional deletion of the transcriptional coactivator Mediator 1 (Med1) changes epidermal lineages and accelerates wound re-epithelialization. Here, we studied a molecular mechanism by which Med1 facilitates these processes, in particular, by focusing on TGFβ signaling through genome wide transcriptome analysis. The expression of the TGF ligands (Tgfβ1/β2) and their downstream target genes is decreased in both normal and wounded Med1 null skin. Med1 silencing in cultured keratinocytes likewise reduces the expression of the ligands (TGFβ1/β2) and diminishes activity of TGFβ signaling as shown by decreased p-Smad2/3. Silencing Med1 increases keratinocyte proliferation and migration in vitro. Epigenetic studies using chromatin immuno-precipitation and next generation DNA sequencing reveals that Med1 regulates transcription of TGFβ components by forming large clusters of enhancers called super-enhancers at the regulatory regions of the TGFβ ligand and SMAD3 genes. These results demonstrate that Med1 is required for the maintenance of the TGFβ signaling pathway. Finally, we show that pharmacological inhibition of TGFβ signaling enhances epidermal lineages and accelerates wound re-epithelialization in skin similar to that seen in the Med1 null mice, providing new insights into epidermal regeneration.
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Affiliation(s)
- Yuko Oda
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
- * E-mail:
| | - Thai Nguyen
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
| | - Akiko Hata
- Cardiovascular Research Institute, University of California, San Francisco, CA, United States of America
- Department of Biochemistry and Biophysics, University of California, San Francisco, CA, United States of America
| | - Mark B. Meyer
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - J. Wesley Pike
- Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin, United States of America
| | - Daniel D. Bikle
- Departments of Medicine and Endocrinology, University of California San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, CA, United States of America
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McGregor R, Chauss D, Freiwald T, Yan B, Wang L, Nova-Lamperti E, Zhang Z, Teague H, West EE, Bibby J, Kelly A, Malik A, Freeman AF, Schwartz D, Portilla D, John S, Lavender P, Lionakis MS, Mehta NN, Kemper C, Cooper N, Lombardi G, Laurence A, Kazemian M, Afzali B. An autocrine Vitamin D-driven Th1 shutdown program can be exploited for COVID-19. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2020. [PMID: 32743590 DOI: 10.1101/2020.07.18.210161] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Pro-inflammatory immune responses are necessary for effective pathogen clearance, but cause severe tissue damage if not shut down in a timely manner 1,2 . Excessive complement and IFN-γ-associated responses are known drivers of immunopathogenesis 3 and are among the most highly induced immune programs in hyper-inflammatory SARS-CoV2 lung infection 4 . The molecular mechanisms that govern orderly shutdown and retraction of these responses remain poorly understood. Here, we show that complement triggers contraction of IFN-γ producing CD4 + T helper (Th) 1 cell responses by inducing expression of the vitamin D (VitD) receptor (VDR) and CYP27B1, the enzyme that activates VitD, permitting T cells to both activate and respond to VitD. VitD then initiates the transition from pro-inflammatory IFN-γ + Th1 cells to suppressive IL-10 + Th1 cells. This process is primed by dynamic changes in the epigenetic landscape of CD4 + T cells, generating superenhancers and recruiting c-JUN and BACH2, a key immunoregulatory transcription factor 5-7 . Accordingly, cells in psoriatic skin treated with VitD increased BACH2 expression, and BACH2 haplo-insufficient CD4 + T cells were defective in IL-10 production. As proof-of-concept, we show that CD4 + T cells in the bronchoalveolar lavage fluid (BALF) of patients with COVID-19 are Th1-skewed and that VDR is among the top regulators of genes induced by SARS-CoV2. Importantly, genes normally down-regulated by VitD were de-repressed in CD4 + BALF T cells of COVID-19, indicating that the VitD-driven shutdown program is impaired in this setting. The active metabolite of VitD, alfacalcidol, and cortico-steroids were among the top predicted pharmaceuticals that could normalize SARS-CoV2 induced genes. These data indicate that adjunct therapy with VitD in the context of other immunomodulatory drugs may be a beneficial strategy to dampen hyperinflammation in severe COVID-19.
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10
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Guo P, Huang J, Zhang J, Meng C, Zhang S, Bai Y, Ning Z, Hu L. The potential role of circRNA_004229 in hair/epidermal regulation after MED1 ablation in keratinocytes. RSC Adv 2019; 9:19095-19103. [PMID: 35516890 PMCID: PMC9065014 DOI: 10.1039/c9ra02322d] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Accepted: 06/11/2019] [Indexed: 01/03/2023] Open
Abstract
Background/Aims: Mediator complex subunit 1 (MED1) is an important transcriptional co-activator involved in multiple signaling pathways. Previous studies indicated an essential role of MED1 in hair cycling and wound repair through regulating the transcription of mRNAs. Circular RNAs (circRNAs), as a novel class of non-coding RNAs, are involved in various skin biological functions. Our study aimed to investigate the circRNAs expression profile in MED1 epidermal conditional knockout mice (KO), and provide potential candidates as well as the mechanism underlying the circRNAs regulation in both hair follicles and epidermis. Method: Microarray based circRNA expression was determined in MED1 KO mice and wild type mice (WT). The expression level was further confirmed by qRT-PCR. We predicted a possible interaction network of circRNA/microRNA/mRNA by bioinformatics and constructed them with Cytoscape software. Expression of several candidate target mRNAs was verified using qRT-PCR. A TUNEL assay was performed to assess the apoptosis level of MED1 KO and WT skin. Results: Here we identified 109 (34-up, 75-down) distinct circRNAs through microarrays that are differently expressed in MED1 KO mice compared with WT mice (FC > 2 and p-value < 0.05), suggesting a potential role of circRNAs in epidermal regulation. Among these circRNAs, circRNA_004229 was found to decrease significantly after MED1 deletion. The most likely potential targets miRNA for circRNA_004229 include miR-149-5p and miR-207, which possibly further impede the expression of their target mRNA, Tnfrsf19 and Perp, respectively. Apoptosis was suppressed in MED1 KO mice, which implies a potential role of circRNAs in regulating epidermal biological processes including apoptosis. Conclusion: Our study determined the expression profile of circRNAs in MED1 KO skin, and provided hints that circRNA_004229 might be involved in the regulation of keratinocytes in both hair follicles and interfollicular epidermis through a ceRNA mechanism. We demonstrated that circRNA_004229 might inhibit apoptosis through binding miR-207 and miR-149-5p after MED1 deletion in keratinocytes.![]()
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Affiliation(s)
- Pan Guo
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
| | - Junkai Huang
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
| | - Jing Zhang
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
| | - Chao Meng
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
| | - Shuchang Zhang
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
| | - Yunfeng Bai
- Center of Integrative Medicine
- 302 Hospital of Chinese People's Liberation Army
- Beijing
- China
| | - Zhiwei Ning
- Department of Endocrinology and Metabolism
- Beijing Chaoyang Hospital
- Capital Medical University
- Beijing
- China
| | - Lizhi Hu
- Immunology Department
- Key Laboratory of Immune Microenvironment and Disease (Ministry of Education)
- Tianjin Medical University
- Tianjin
- China
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11
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Jusu S, Presley JF, Williams C, Das SK, Jean-Claude B, Kremer R. Examination of VDR/RXR/DRIP205 Interaction, Intranuclear Localization, and DNA Binding in Ras-Transformed Keratinocytes and Its Implication for Designing Optimal Vitamin D Therapy in Cancer. Endocrinology 2018; 159:1303-1327. [PMID: 29300860 DOI: 10.1210/en.2017-03098] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2017] [Accepted: 12/19/2017] [Indexed: 11/19/2022]
Abstract
Retinoid X receptor (RXR) occupies a central position within the nuclear receptor superfamily, serving as an obligatory partner to numerous other nuclear receptors, including vitamin D receptor (VDR). In the current study, we examined whether phosphorylation of RXRα at serine 260 affects VDR/RXR and VDR interacting protein (DRIP) 205 coactivator recruitment, interactions, and binding of the VDR/human RXRα (hRXRα)/DRIP205 complex to chromatin. Serine 260 is a critical amino acid on the hRXRα that is located in close spatial proximity to regions of coactivator and corepressor interactions. Using fluorescence resonance energy transfer and immunofluorescence studies, we showed that the physical interaction between hRXRα and DRIP205 coactivator was impaired in human keratinocytes with the ras oncogene (HPK1Aras) or transfected with the wild-type hRXRα. Furthermore, the nuclear colocalization of VDR/DRIP205, hRXRα/DRIP205, and VDR/hRXRα/DRIP205 complex binding to chromatin is impaired in the HPK1Aras cells when compared with the normal human keratinocytes (HPK1A cells). However, transfection with the nonphosphorylatable hRXRα (S260A) mutant or treatment with the mitogen-activated protein kinase (MAPK) inhibitor UO126 rescued their nuclear localization, interaction, and binding of the complex to chromatin in the HPK1Aras cells. In summary, we have demonstrated, using highly specific intracellular tagging methods in live and fixed cells, important alterations of the vitamin D signaling system in cancer cells in which the ras-raf-MAPK system is activated, suggesting that specific inhibition of this commonly activated pathway could be targeted therapeutically to enhance vitamin D efficacy.
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Affiliation(s)
- Sylvester Jusu
- Department of Medicine and Calcium Research Laboratory, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada
- Metabolic Diseases and Complications Program, Research institute-McGill University Health Centre, Montreal, Quebec, Canada
| | - John F Presley
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
| | | | - Sanjoy Kumar Das
- Drug Discovery Core, Research Institute-McGill University Health Centre, Montreal, Quebec H3A 3J1, Canada
| | - Bertrand Jean-Claude
- Metabolic Diseases and Complications Program, Research institute-McGill University Health Centre, Montreal, Quebec, Canada
- Drug Discovery Core, Research Institute-McGill University Health Centre, Montreal, Quebec H3A 3J1, Canada
| | - Richard Kremer
- Department of Medicine and Calcium Research Laboratory, Royal Victoria Hospital, McGill University Health Centre, Montreal, Quebec, Canada
- Metabolic Diseases and Complications Program, Research institute-McGill University Health Centre, Montreal, Quebec, Canada
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12
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Bikle DD. Extraskeletal actions of vitamin D. Ann N Y Acad Sci 2017; 1376:29-52. [PMID: 27649525 DOI: 10.1111/nyas.13219] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2016] [Revised: 07/26/2016] [Accepted: 08/03/2016] [Indexed: 12/16/2022]
Abstract
The vitamin D receptor (VDR) is found in nearly all, if not all, cells in the body. The enzyme that produces the active metabolite of vitamin D and ligand for VDR, namely CYP27B1, likewise is widely expressed in many cells of the body. These observations indicate that the role of vitamin D is not limited to regulation of bone and mineral homeostasis, as important as that is. Rather, the study of its extraskeletal actions has become the major driving force behind the significant increase in research articles on vitamin D published over the past several decades. A great deal of information has accumulated from cell culture studies, in vivo animal studies, and clinical association studies that confirms that extraskeletal effects of vitamin D are truly widespread and substantial. However, randomized, placebo-controlled clinical trials, when done, have by and large not produced the benefits anticipated by the in vitro cell culture and in vivo animal studies. In this review, I will examine the role of vitamin D signaling in a number of extraskeletal tissues and assess the success of translating these findings into treatments of human diseases affecting those extracellular tissues.
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Affiliation(s)
- Daniel D Bikle
- Departments of Medicine and Dermatology, Veterans Affairs Medical Center and University of California, San Francisco, San Francisco, California.
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13
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Silvagno F, Pescarmona G. Spotlight on vitamin D receptor, lipid metabolism and mitochondria: Some preliminary emerging issues. Mol Cell Endocrinol 2017; 450:24-31. [PMID: 28414049 DOI: 10.1016/j.mce.2017.04.013] [Citation(s) in RCA: 42] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/07/2017] [Accepted: 04/09/2017] [Indexed: 12/19/2022]
Abstract
Transcriptional control and modulation of calcium fluxes underpin the differentiating properties of vitamin D (1,25(OH)2D3). In the latest years however few studies have pointed out the relevance of the mitochondrial effects of the hormone. It is now time to focus on the metabolic results of vitamin D receptor (VDR) action in mitochondria, which can explain the pleiotropic effects of 1,25(OH)2D3 and may elucidate few contrasting aspects of its activity. The perturbation of lipid metabolism described in VDR knockout mice and vitamin D deficient animals can be revisited based on the newly identified mechanism of action of 1,25(OH)2D3 in mitochondria. From the same point of view, the controversial role of 1,25(OH)2D3 in adipogenesis can be better interpreted.
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Affiliation(s)
- Francesca Silvagno
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy.
| | - Gianpiero Pescarmona
- Department of Oncology, University of Torino, Via Santena 5 bis, 10126 Torino, Italy.
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14
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Yoshizaki K, Hu L, Nguyen T, Sakai K, Ishikawa M, Takahashi I, Fukumoto S, DenBesten PK, Bikle DD, Oda Y, Yamada Y. Mediator 1 contributes to enamel mineralization as a coactivator for Notch1 signaling and stimulates transcription of the alkaline phosphatase gene. J Biol Chem 2017; 292:13531-13540. [PMID: 28673966 DOI: 10.1074/jbc.m117.780866] [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: 02/24/2017] [Revised: 06/17/2017] [Indexed: 12/21/2022] Open
Abstract
Tooth enamel is mineralized through the differentiation of multiple dental epithelia including ameloblasts and the stratum intermedium (SI), and this differentiation is controlled by several signaling pathways. Previously, we demonstrated that the transcriptional coactivator Mediator 1 (MED1) plays a critical role in enamel formation. For instance, conditional ablation of Med1 in dental epithelia causes functional changes in incisor-specific dental epithelial stem cells, resulting in mineralization defects in the adult incisors. However, the molecular mechanism by which Med1 deficiency causes these abnormalities is not clear. Here, we demonstrated that Med1 ablation causes early SI differentiation defects resulting in enamel hypoplasia of the Med1-deficient molars. Med1 deletion prevented Notch1-mediated differentiation of the SI cells resulting in decreased alkaline phosphatase (ALPL), which is essential for mineralization. However, it does not affect the ability of ameloblasts to produce enamel matrix proteins. Using the dental epithelial SF2 cell line, we demonstrated that MED1 directly activates transcription of the Alpl gene through the stimulation of Notch1 signaling by forming a complex with cleaved Notch1-RBP-Jk on the Alpl promoter. These results suggest that MED1 may be essential for enamel matrix mineralization by serving as a coactivator for Notch1 signaling regulating transcription of the Alpl gene.
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Affiliation(s)
- Keigo Yoshizaki
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892.,the Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan
| | - Lizhi Hu
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Thai Nguyen
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Kiyoshi Sakai
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Masaki Ishikawa
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892
| | - Ichiro Takahashi
- the Division of Oral Health, Growth, and Development, Kyushu University Faculty of Dental Science, Fukuoka 812-8582, Japan
| | - Satoshi Fukumoto
- the Division of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate School of Dentistry, Sendai 980-8575, Japan, and
| | - Pamela K DenBesten
- the University of California San Francisco School of Dentistry, San Francisco, California 94143
| | - Daniel D Bikle
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158
| | - Yuko Oda
- the Departments of Medicine and Dermatology, the University of California San Francisco and the Veterans Affairs Medical Center, San Francisco, California 94158,
| | - Yoshihiko Yamada
- From the Laboratory of Cell and Developmental Biology, NIDCR, National Institutes of Health, Bethesda, Maryland 20892,
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15
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Oda Y, Hu L, Nguyen T, Fong C, Tu CL, Bikle DD. Combined Deletion of the Vitamin D Receptor and Calcium-Sensing Receptor Delays Wound Re-epithelialization. Endocrinology 2017; 158:1929-1938. [PMID: 28368538 PMCID: PMC5460927 DOI: 10.1210/en.2017-00061] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/08/2017] [Indexed: 12/28/2022]
Abstract
When the skin is injured, keratinocytes proliferate, migrate, and differentiate to regenerate the epidermis. We recently showed that ablation of the vitamin D receptor (Vdr) in keratinocytes delays wound re-epithelialization in mice also fed a low-calcium diet, implicating a cooperative role of Vdr and calcium signaling in this process. In this study, we examined the role of vitamin D and calcium signaling in wound healing by deleting their receptors, Vdr and the calcium-sensing receptor (Casr). Gene expression profiling of neonatal epidermis lacking both Vdr and Casr [Vdr and Casr double knockout (DKO)] specifically in keratinocytes revealed that DKO affects a number of pathways relevant to wound healing, including Vdr, β-catenin, and adherens junction (AJ) signaling. In adult skin, DKO caused a significant delay in wound closure and re-epithelialization, whereas myofibroblast numbers and matrix deposition were unaffected. The injury-induced proliferation of epidermal keratinocytes was blunted in both epidermis and hair follicles, and expression of β-catenin target genes was reduced in the DKO. Expression of E-cadherin and desmoglein 1 was reduced in the shortened leading edges of the epithelial tongues re-epithelializing the wounds, consistent with the decreased migration rate of DKO keratinocytes in vitro. These results demonstrate that Vdr and Casr are required for β-catenin-regulated cell proliferation and AJ formation essential for re-epithelialization after wounding. We conclude that vitamin D and calcium signaling in keratinocytes are required for a normal regenerative response of the skin to wounding.
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Affiliation(s)
- Yuko Oda
- Department of Medicine, University of California San Francisco, San Francisco, California 94158
- Department of Dermatology, University of California San Francisco, San Francisco, California 94158
| | - Lizhi Hu
- Department of Medicine, University of California San Francisco, San Francisco, California 94158
- School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Thai Nguyen
- San Francisco Veterans Affairs Medical Center, San Francisco, California 94158
| | - Chak Fong
- San Francisco Veterans Affairs Medical Center, San Francisco, California 94158
| | - Chia-ling Tu
- San Francisco Veterans Affairs Medical Center, San Francisco, California 94158
| | - Daniel D. Bikle
- San Francisco Veterans Affairs Medical Center, San Francisco, California 94158
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16
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Relationship between Structure and Conformational Change of the Vitamin D Receptor Ligand Binding Domain in 1α,25-Dihydroxyvitamin D3 Signaling. Molecules 2015; 20:20473-86. [PMID: 26593892 PMCID: PMC6332228 DOI: 10.3390/molecules201119713] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 11/02/2015] [Accepted: 11/11/2015] [Indexed: 12/24/2022] Open
Abstract
Vitamin D Receptor (VDR) belongs to the nuclear receptor (NR) superfamily. Whereas the structure of the ligand binding domain (LBD) of VDR has been determined in great detail, the role of its amino acid residues in stabilizing the structure and ligand triggering conformational change is still under debate. There are 13 α-helices and one β-sheet in the VDR LBD and they form a three-layer sandwich structure stabilized by 10 residues. Thirty-six amino acid residues line the ligand binding pocket (LBP) and six of these residues have hydrogen-bonds linking with the ligand. In 1α,25-dihydroxyvitamin D3 signaling, H3 and H12 play an important role in the course of conformational change resulting in the provision of interfaces for dimerization, coactivator (CoA), corepressor (CoR), and hTAFII 28. In this paper we provide a detailed description of the amino acid residues stabilizing the structure and taking part in conformational change of VDR LBD according to functional domains.
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17
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Chun RF, Liu NQ, Lee T, Schall JI, Denburg MR, Rutstein RM, Adams JS, Zemel BS, Stallings VA, Hewison M. Vitamin D supplementation and antibacterial immune responses in adolescents and young adults with HIV/AIDS. J Steroid Biochem Mol Biol 2015; 148:290-7. [PMID: 25092518 PMCID: PMC4312738 DOI: 10.1016/j.jsbmb.2014.07.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 07/26/2014] [Accepted: 07/31/2014] [Indexed: 12/22/2022]
Abstract
Human monocytes activated by toll-like receptor 2/1 ligand (TLR2/1L) show enhanced expression of the vitamin D receptor (VDR) and the vitamin D-activating enzyme 1α-hydroxylase (CYP27B1). The resulting intracrine conversion of precursor 25-hydroxyvitamin D3 (25OHD) to active 1,25-dihydroxyvitamin D (1,25(OH)2D) can stimulate expression of antibacterial cathelicidin (CAMP). To determine whether this response is functional in HIV-infected subjects (HIV+ ), serum from HIV+ subjects pre- and post-vitamin D supplementation was utilized in monocyte cultures with or without TLR2/1L. Expression of CYP27B1 and VDR was enhanced following treatment with TLR2/1L, although this effect was lower in HIV+ vs HIV- serum (p<0.05). CAMP was also lower in TLR2/1L-treated monocytes cultured in HIV+ serum (p<0.01). In a dose study, supplementation of HIV+ subjects with 4000IU or 7000IU vitamin D/day increased serum 25OHD from 17.3±8.0 and 20.6±6.2ng/ml (43nM and 51nM) at baseline to 41.1±12.0 and 51.9±23.1ng/ml (103nM and 130nM) after 12 weeks (both p<0.001). Greater percent change from baseline 25OHD was significantly associated with enhanced TLR2/1L-induced monocyte CAMP adjusted for baseline expression (p=0.009). In a randomized placebo-controlled trial, 7000IU vitamin D/day increased serum 25OHD from 18.0±8.6 to 32.7±13.8ng/ml (45nM and 82nM) after 12 weeks. Expression of CAMP increased significantly from baseline after 52 weeks of vitamin D-supplementation. At this time point, TLR2/1L-induced CAMP was positively associated with percent change from baseline in 25OHD (p=0.029 overall and 0.002 within vitamin D-supplemented only). These data indicate that vitamin D supplementation in HIV-infected subjects can promote improved antibacterial immunity, but also suggest that longer periods of supplementation are required to achieve this.
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Affiliation(s)
- Rene F Chun
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California, Los Angeles, CA 90095, USA
| | - Nancy Q Liu
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California, Los Angeles, CA 90095, USA
| | - T Lee
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California, Los Angeles, CA 90095, USA
| | | | - Michelle R Denburg
- Division of Nephrology, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104
| | - Richard M Rutstein
- General Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104
| | - John S Adams
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California, Los Angeles, CA 90095, USA
| | - Babette S Zemel
- Gastroenterology, Hepatology and Nutrition, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104
| | - Virginia A Stallings
- Gastroenterology, Hepatology and Nutrition, USA; Department of Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104
| | - Martin Hewison
- UCLA Orthopaedic Hospital, Department of Orthopaedic Surgery, Orthopedic Hospital, University of California, Los Angeles, CA 90095, USA.
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18
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Hu L, Bikle DD, Oda Y. Reciprocal role of vitamin D receptor on β-catenin regulated keratinocyte proliferation and differentiation. J Steroid Biochem Mol Biol 2014; 144 Pt A:237-41. [PMID: 24239508 PMCID: PMC4061268 DOI: 10.1016/j.jsbmb.2013.11.002] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/27/2013] [Revised: 10/18/2013] [Accepted: 11/05/2013] [Indexed: 12/28/2022]
Abstract
The active metabolite of vitamin D, 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), suppresses the proliferation while promoting the differentiation of keratinocytes through the vitamin D receptor (VDR). β-Catenin, on the other hand, promotes proliferation and blocks epidermal differentiation, although it stimulates hair follicle differentiation. In intestinal epithelia VDR binds β-catenin and blocks its proliferative effects. In this study we investigated the role of 1,25(OH)2D3/VDR on β-catenin regulated gene transcription during keratinocyte proliferation and differentiation. 1,25(OH)2D3 suppressed promoter reporter activity driven by synthetic and natural TCF/β-catenin response elements. Over-expression of VDR further suppressed these TCF/β-catenin promoter activities. 1,25(OH)2D3 also suppressed the mRNA expression of the β-catenin regulated gene Gli1 through VDR. These data were consistent with our previous observations that VDR silencing resulted in keratinocyte hyperproliferation with increased expression of Gli1 in vitro, whereas VDR null skin showed hyperproliferation in vivo. In contrast, 1,25(OH)2D3 induced expression of another β-catenin regulated gene, PADI1, important for both epidermal and hair follicle differentiation. Deletion of VDR resulted in defects in hair differentiation in vivo, with decreased expression of β-catenin regulated hair differentiation genes such as PADI1, hair keratin KRT31 and calcium binding protein S100a3. These genes possess vitamin D response elements (VDRE) adjacent to TCF/β-catenin response elements and are regulated by both VDR and β-catenin signaling. Therefore, we propose that VDR and β-catenin interact reciprocally to promote VDR stimulation of genes involved with differentiation that contain both VDR and β-catenin response elements while inhibiting β-catenin stimulation of genes involved with proliferation. Thus the major finding of this study is that while 1,25(OH)2D3/VDR inhibits the actions of β-catenin to promote keratinocyte proliferation, 1,25(OH)2D3/VDR promotes the ability of β-catenin to stimulate hair follicle differentiation. This article is part of a Special Issue entitled '16th Vitamin D Workshop'.
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Affiliation(s)
- Lizhi Hu
- Department of Medicine, University of California, San Francisco, San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94121, USA; School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China
| | - Daniel D Bikle
- Department of Medicine, University of California, San Francisco, San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94121, USA
| | - Yuko Oda
- Department of Medicine, University of California, San Francisco, San Francisco and Veterans Affairs Medical Center, San Francisco, CA 94121, USA.
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19
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Waters KM, Cummings BS, Shankaran H, Scholpa NE, Weber TJ. ERK oscillation-dependent gene expression patterns and deregulation by stress response. Chem Res Toxicol 2014; 27:1496-503. [PMID: 25068892 PMCID: PMC4163986 DOI: 10.1021/tx500085u] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
![]()
Studies were undertaken to determine
whether extracellular signal
regulated kinase (ERK) oscillations regulate a unique subset of genes
in human keratinocytes and subsequently whether the p38 stress response
inhibits ERK oscillations. A DNA microarray identified many genes
that were unique to ERK oscillations, and network reconstruction predicted
an important role for the mediator complex subunit 1 (MED1) node in
mediating ERK oscillation-dependent gene expression. Increased ERK-dependent
phosphorylation of MED1 was observed in oscillating cells compared
to nonoscillating counterparts as validation. Treatment of keratinocytes
with a p38 inhibitor (SB203580) increased ERK oscillation amplitudes
and MED1 and phospho-MED1 protein levels. Bromate is a probable human
carcinogen that activates p38. Bromate inhibited ERK oscillations
in human keratinocytes and JB6 cells and induced an increase in phospho-p38
and a decrease in phospho-MED1 protein levels. Treatment of normal
rat kidney cells and primary salivary gland epithelial cells with
bromate decreased phospho-MED1 levels in a reversible fashion upon
treatment with p38 inhibitors (SB202190; SB203580). Our results indicate
that oscillatory behavior in the ERK pathway alters homeostatic gene
regulation patterns and that the cellular response to perturbation
may manifest differently in oscillating vs nonoscillating cells.
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Affiliation(s)
- Katrina M Waters
- Computational Biology and Bioinformatics, ‡Systems Toxicology and Exposure Science, Pacific Northwest National Laboratory , Richland, Washington 99352, United States
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20
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Ablation of coactivator Med1 switches the cell fate of dental epithelia to that generating hair. PLoS One 2014; 9:e99991. [PMID: 24949995 PMCID: PMC4065011 DOI: 10.1371/journal.pone.0099991] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Accepted: 05/21/2014] [Indexed: 01/11/2023] Open
Abstract
Cell fates are determined by specific transcriptional programs. Here we provide evidence that the transcriptional coactivator, Mediator 1 (Med1), is essential for the cell fate determination of ectodermal epithelia. Conditional deletion of Med1 in vivo converted dental epithelia into epidermal epithelia, causing defects in enamel organ development while promoting hair formation in the incisors. We identified multiple processes by which hairs are generated in Med1 deficient incisors: 1) dental epithelial stem cells lacking Med 1 fail to commit to the dental lineage, 2) Sox2-expressing stem cells extend into the differentiation zone and remain multi-potent due to reduced Notch1 signaling, and 3) epidermal fate is induced by calcium as demonstrated in dental epithelial cell cultures. These results demonstrate that Med1 is a master regulator in adult stem cells to govern epithelial cell fate.
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21
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Yin JW, Wang G. The Mediator complex: a master coordinator of transcription and cell lineage development. Development 2014; 141:977-87. [PMID: 24550107 DOI: 10.1242/dev.098392] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mediator is a multiprotein complex that is required for gene transcription by RNA polymerase II. Multiple subunits of the complex show specificity in relaying information from signals and transcription factors to the RNA polymerase II machinery, thus enabling control of the expression of specific genes. Recent studies have also provided novel mechanistic insights into the roles of Mediator in epigenetic regulation, transcriptional elongation, termination, mRNA processing, noncoding RNA activation and super enhancer formation. Based on these specific roles in gene regulation, Mediator has emerged as a master coordinator of development and cell lineage determination. Here, we describe the most recent advances in understanding the mechanisms of Mediator function, with an emphasis on its role during development and disease.
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Affiliation(s)
- Jing-wen Yin
- State Key Laboratory of Cell Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031, China
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Yuan FNF, Valiyaparambil J, Woods MC, Tran H, Pant R, Adams JS, Mallya SM. Vitamin D signaling regulates oral keratinocyte proliferation in vitro and in vivo. Int J Oncol 2014; 44:1625-33. [PMID: 24626468 PMCID: PMC4027942 DOI: 10.3892/ijo.2014.2338] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 01/29/2014] [Indexed: 11/17/2022] Open
Abstract
The secosteroidal hormone 1,25-dihyroxyvitamin D [1,25(OH)2D3] and its receptor, the vitamin D receptor (VDR), are crucial regulators of epidermal proliferation and differentiation. However, the effects of 1,25(OH)2D3-directed signaling on oral keratinocyte pathophysiology have not been well studied. We examined the role of 1,25(OH)2D3 in regulating proliferation and differentiation in cultured oral keratinocytes and on the oral epithelium in vivo. Using lentiviral-mediated shRNA to silence VDR, we generated an oral keratinocyte cell line with stable knockdown of VDR expression. VDR knockdown significantly enhanced proliferation and disrupted calcium- and 1,25(OH)2D3-induced oral keratinocyte differentiation, emphasizing the anti-proliferative and pro-differentiation effects of 1,25(OH)2D3 in oral keratinocytes. Using vitamin D3-deficient diets, we induced chronic vitamin D deficiency in mice as evidenced by decreased serum 25-hydroxyvitamin D (25OHD) concentrations. The vitamin D-deficient mice manifested increased proliferation of the tongue epithelium, but did not develop any morphological or histological abnormalities in the oral epithelium, suggesting that vitamin D deficiency alone is insufficient to alter oral epithelial homeostasis and provoke carcinogenesis. Immunohistochemical analyses of human and murine oral squamous cell carcinomas showed increased VDR expression. Overall, our results provide strong support for a crucial role for vitamin D signaling in oral keratinocyte pathophysiology.
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Affiliation(s)
- Feng-Ning F Yuan
- Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | | | - Michael C Woods
- Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Huy Tran
- Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles, CA 90095, USA
| | - Rima Pant
- University of Connecticut Health Center, School of Dental Medicine, Farmington, CT 06032, USA
| | - John S Adams
- Orthopaedic Hospital Research Center and Department of Orthopaedic Surgery, David Geffen School of Medicine at UCLA, University of California, Los Angeles, CA 90095, USA
| | - Sanjay M Mallya
- Division of Diagnostic and Surgical Sciences, School of Dentistry, University of California, Los Angeles, CA 90095, USA
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23
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Moukayed M, Grant WB. Molecular link between vitamin D and cancer prevention. Nutrients 2013; 5:3993-4021. [PMID: 24084056 PMCID: PMC3820056 DOI: 10.3390/nu5103993] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 09/11/2013] [Accepted: 09/18/2013] [Indexed: 01/03/2023] Open
Abstract
The metabolite of vitamin D, 1α,25-dihydroxyvitamin D₃ (also known as calcitriol), is a biologically active molecule required to maintain the physiological functions of several target tissues in the human body from conception to adulthood. Its molecular mode of action ranges from immediate nongenomic responses to longer term mechanisms that exert persistent genomic effects. The genomic mechanisms of vitamin D action rely on cross talk between 1α,25-dihydroxyvitamin D₃ signaling pathways and that of other growth factors or hormones that collectively regulate cell proliferation, differentiation and cell survival. In vitro and in vivo studies demonstrate a role for vitamin D (calcitriol) in modulating cellular growth and development. Vitamin D (calcitriol) acts as an antiproliferative agent in many tissues and significantly slows malignant cellular growth. Moreover, epidemiological studies have suggested that ultraviolet-B exposure can help reduce cancer risk and prevalence, indicating a potential role for vitamin D as a feasible agent to prevent cancer incidence and recurrence. With the preventive potential of this biologically active agent, we suggest that countries where cancer is on the rise--yet where sunlight and, hence, vitamin D may be easily acquired--adopt awareness, education and implementation strategies to increase supplementation with vitamin D in all age groups as a preventive measure to reduce cancer risk and prevalence.
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Affiliation(s)
- Meis Moukayed
- School of Arts and Sciences, American University in Dubai, P. O. Box 28282, Dubai, UAE; E-Mail:
| | - William B. Grant
- Sunlight, Nutrition, and Health Research Center, San Francisco, CA 94164-1603, USA
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24
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Kongsbak M, Levring TB, Geisler C, von Essen MR. The vitamin d receptor and T cell function. Front Immunol 2013; 4:148. [PMID: 23785369 PMCID: PMC3684798 DOI: 10.3389/fimmu.2013.00148] [Citation(s) in RCA: 194] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/29/2013] [Indexed: 12/14/2022] Open
Abstract
The vitamin D receptor (VDR) is a nuclear, ligand-dependent transcription factor that in complex with hormonally active vitamin D, 1,25(OH)2D3, regulates the expression of more than 900 genes involved in a wide array of physiological functions. The impact of 1,25(OH)2D3-VDR signaling on immune function has been the focus of many recent studies as a link between 1,25(OH)2D3 and susceptibility to various infections and to development of a variety of inflammatory diseases has been suggested. It is also becoming increasingly clear that microbes slow down immune reactivity by dysregulating the VDR ultimately to increase their chance of survival. Immune modulatory therapies that enhance VDR expression and activity are therefore considered in the clinic today to a greater extent. As T cells are of great importance for both protective immunity and development of inflammatory diseases a variety of studies have been engaged investigating the impact of VDR expression in T cells and found that VDR expression and activity plays an important role in both T cell development, differentiation and effector function. In this review we will analyze current knowledge of VDR regulation and function in T cells and discuss its importance for immune activity.
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Affiliation(s)
- Martin Kongsbak
- Department of International Health, Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen , Copenhagen , Denmark
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25
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Tu CL, Bikle DD. Role of the calcium-sensing receptor in calcium regulation of epidermal differentiation and function. Best Pract Res Clin Endocrinol Metab 2013; 27:415-27. [PMID: 23856269 PMCID: PMC3713412 DOI: 10.1016/j.beem.2013.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The epidermis is a stratified squamous epithelium composed of proliferating basal and differentiated suprabasal keratinocytes. It serves as the body's major physical and chemical barrier against infection and harsh environmental insults, as well as preventing excess water loss from the body into the atmosphere. Calcium is a key regulator of the proliferation and differentiation in keratinocytes. Elevated extracellular Ca(2+) concentration ([Ca(2+)]o) raises the levels of intracellular free calcium ([Ca(2+)]i), promotes cell-cell adhesion, and activates differentiation-related genes. Keratinocytes deficient in the calcium-sensing receptor fail to respond to [Ca(2+)]o stimulation and to differentiate, indicating a role for the calcium-sensing receptor in transducing the [Ca(2+)]o signal during differentiation. The concepts derived from in vitro gene knockdown experiments have been evaluated and confirmed in three mouse models in vivo.
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Affiliation(s)
- Chia-Ling Tu
- Endocrine Unit, Veterans Affair Medical Center and The University of California, San Francisco, CA, USA
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26
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Nowak R, Szota J, Mazurek U. Vitamin D receptor gene (VDR) transcripts in bone, cartilage, muscles and blood and microarray analysis of vitamin D responsive genes expression in paravertebral muscles of juvenile and adolescent idiopathic scoliosis patients. BMC Musculoskelet Disord 2012; 13:259. [PMID: 23259508 PMCID: PMC3532837 DOI: 10.1186/1471-2474-13-259] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 12/17/2012] [Indexed: 12/20/2022] Open
Abstract
BACKGROUND VDR may be considered as a candidate gene potentially related to idiopathic scoliosis susceptibility and natural history. Transcriptional profile of VDR mRNA isoforms might be changed in the structural tissues of the scoliotic spine and potentially influence the expression of VDR responsive genes. The purpose of the study was to determine differences in mRNA abundance of VDR isoforms in bone, cartilage and paravertebral muscles between tissues from curve concavity and convexity, between JIS and AIS and to identify VDR responsive genes differentiating juvenile and adolescent idiopathic scoliosis in paravertebral muscles. METHODS In a group of 29 patients with JIS and AIS, specimens of bone, cartilage, paravertebral muscles were harvested at the both sides of the curve apex together with peripheral blood samples. Extracted total RNA served as a matrix for VDRs and VDRl mRNA quantification by QRT PCR. Subsequent microarray analysis of paravertebral muscular tissue samples was performed with HG U133A chips (Affymetrix). Quantitative data were compared by a nonparametric Mann Whitney U test. Microarray results were analyzed with GeneSpring 11GX application. Matrix plot of normalized log-intensities visualized the degree of differentiation between muscular tissue transcriptomes of JIS and AIS group. Fold Change Analysis with cutoff of Fold Change ≥2 identified differentially expressed VDR responsive genes in paravertebral muscles of JIS and AIS. RESULTS No significant differences in transcript abundance of VDR isoforms between tissues of the curve concavity and convexity were found. Statistically significant difference between JIS and AIS group in mRNA abundance of VDRl isoform was found in paravertebral muscles of curve concavity. Higher degree of muscular transcriptome differentiation between curve concavity and convexity was visualized in JIS group. In paravertebral muscles Tob2 and MED13 were selected as genes differentially expressed in JIS and AIS group. CONCLUSIONS In Idiopathic Scolioses transcriptional activity and alternative splicing of VDR mRNA in osseous, cartilaginous, and paravertebral muscular tissues are tissue specific and equal on both sides of the curve. The number of mRNA copies of VDRl izoform in concave paravertebral muscles might be one of the factors differentiating JIS and AIS. In paravertebral muscles Tob2 and Med13 genes differentiate Adolescent and Juvenile type of Idiopathic Scoliosis.
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Affiliation(s)
- Roman Nowak
- Orthopaedics Clinic Medical University of Silesia, Wojewódzki Szpital Specjalistyczny nr5 41-200 Sosnowiec, Pl. Medyków 1, Poland
| | - Justyna Szota
- Department of Molecular Biology Medical University of Silesia, 41-100 Sosnowiec, ul.Narcyzów 1, Poland
| | - Urszula Mazurek
- Department of Molecular Biology Medical University of Silesia, 41-100 Sosnowiec, ul.Narcyzów 1, Poland
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Oda Y, Hu L, Bul V, Elalieh H, Reddy JK, Bikle DD. Coactivator MED1 ablation in keratinocytes results in hair-cycling defects and epidermal alterations. J Invest Dermatol 2011; 132:1075-83. [PMID: 22189783 PMCID: PMC3400544 DOI: 10.1038/jid.2011.430] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The transcriptional coactivator complex Mediator facilitates transcription of nuclear hormone receptors and other transcription factors. We have previously isolated the Mediator complex from primary keratinocytes as the vitamin D receptor interacting protein complex. We identified a role for Mediator in keratinocyte proliferation and differentiation in cultured keratinocytes. Here, we investigated the in vivo role of Mediator by generating conditional null mice, where a critical subunit of the Mediator complex, MED1, is deleted from their keratinocytes. The MED1 ablation resulted in aberrant hair differentiation and cycling leading to hair loss. During the first hair follicle cycle, MED1 deletion resulted in a rapid regression of the hair follicles. Hair differentiation was reduced, and β-catenin/vitamin D receptor (VDR) regulated gene expression was dramatically decreased. In the subsequent adult hair cycle, MED1 ablation activated the initiation of hair follicle cycling. Shh signaling was increased, but terminal differentiation was not sufficient. Deletion of MED1 also caused hyper-proliferation of interfollicular epidermal keratinocytes, and increased the expression of epidermal differentiation markers. These results indicate that MED1 plays a critical role in regulating hair/epidermal proliferation and differentiation.
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Affiliation(s)
- Yuko Oda
- Department of Medicine and Endocrinology, University of California, San Francisco and Veterans Affairs Medical Center San Francisco, San Francisco, California 94121, USA.
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Unraveling framework of the ancestral Mediator complex in human diseases. Biochimie 2011; 94:579-87. [PMID: 21983542 DOI: 10.1016/j.biochi.2011.09.016] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 09/15/2011] [Indexed: 01/13/2023]
Abstract
Mediator (MED) is a fundamental component of the RNA polymerase II-mediated transcription machinery. This multiprotein complex plays a pivotal role in the regulation of eukaryotic mRNA synthesis. The yeast Mediator complex consists of 26 different subunits. Recent studies indicate additional pathogenic roles for Mediator, for example during transcription elongation and non-coding RNA production. Mediator subunits have been emerging also to have pathophysiological roles suggesting MED-dependent therapeutic targets involving in several diseases, such as cancer, cardiovascular disease (CVD), metabolic and neurological disorders.
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