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Wheeler JR, Whitney ON, Vogler TO, Nguyen ED, Pawlikowski B, Lester E, Cutler A, Elston T, Dalla Betta N, Parker KR, Yost KE, Vogel H, Rando TA, Chang HY, Johnson AM, Parker R, Olwin BB. RNA-binding proteins direct myogenic cell fate decisions. eLife 2022; 11:e75844. [PMID: 35695839 PMCID: PMC9191894 DOI: 10.7554/elife.75844] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 05/20/2022] [Indexed: 11/13/2022] Open
Abstract
RNA-binding proteins (RBPs), essential for skeletal muscle regeneration, cause muscle degeneration and neuromuscular disease when mutated. Why mutations in these ubiquitously expressed RBPs orchestrate complex tissue regeneration and direct cell fate decisions in skeletal muscle remains poorly understood. Single-cell RNA-sequencing of regenerating Mus musculus skeletal muscle reveals that RBP expression, including the expression of many neuromuscular disease-associated RBPs, is temporally regulated in skeletal muscle stem cells and correlates with specific stages of myogenic differentiation. By combining machine learning with RBP engagement scoring, we discovered that the neuromuscular disease-associated RBP Hnrnpa2b1 is a differentiation-specifying regulator of myogenesis that controls myogenic cell fate transitions during terminal differentiation in mice. The timing of RBP expression specifies cell fate transitions by providing post-transcriptional regulation of messenger RNAs that coordinate stem cell fate decisions during tissue regeneration.
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Affiliation(s)
- Joshua R Wheeler
- Department of Biochemistry, University of ColoradoBoulderUnited States
- Medical Scientist Training Program, University of Colorado Anschutz Medical CampusAuroraUnited States
- Howard Hughes Medical Institute, University of ColoradoBoulderUnited States
- Department of Pathology, Stanford UniversityStanfordUnited States
- Department of Neuropathology, Stanford UniversityStanfordUnited States
| | - Oscar N Whitney
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Thomas O Vogler
- Medical Scientist Training Program, University of Colorado Anschutz Medical CampusAuroraUnited States
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
- Department of Surgery, University of ColoradoAuroraUnited States
| | - Eric D Nguyen
- Medical Scientist Training Program, University of Colorado Anschutz Medical CampusAuroraUnited States
- Molecular Biology Program and Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Bradley Pawlikowski
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| | - Evan Lester
- Department of Biochemistry, University of ColoradoBoulderUnited States
- Medical Scientist Training Program, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Alicia Cutler
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| | - Tiffany Elston
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| | - Nicole Dalla Betta
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
| | - Kevin R Parker
- Center for Personal and Dynamic Regulomes, Stanford UniversityPalo AltoUnited States
| | - Kathryn E Yost
- Center for Personal and Dynamic Regulomes, Stanford UniversityPalo AltoUnited States
| | - Hannes Vogel
- Department of Pathology, Stanford UniversityStanfordUnited States
| | - Thomas A Rando
- Department of Neurology and Neurological Sciences, Stanford University School of MedicineStanfordUnited States
- Paul F. Glenn Center for the Biology of Aging, Stanford University School of MedicineStanfordUnited States
- Center for Tissue Regeneration, Repair, and Restoration, Veterans Affairs Palo Alto Health Care SystemPalo AltoUnited States
| | - Howard Y Chang
- Center for Personal and Dynamic Regulomes, Stanford UniversityPalo AltoUnited States
- Howard Hughes Medical Institute, Stanford UniversityStanfordUnited States
| | - Aaron M Johnson
- Molecular Biology Program and Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical CampusAuroraUnited States
- University of Colorado School of Medicine, RNA Bioscience Initiative, University of Colorado Anschutz Medical CampusAuroraUnited States
| | - Roy Parker
- Howard Hughes Medical Institute, University of ColoradoBoulderUnited States
| | - Bradley B Olwin
- Department of Molecular, Cellular and Developmental Biology, University of ColoradoBoulderUnited States
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Cutler AA, Pawlikowski B, Wheeler JR, Dalla Betta N, Elston T, O’Rourke R, Jones K, Olwin BB. The regenerating skeletal muscle niche drives satellite cell return to quiescence. iScience 2022; 25:104444. [PMID: 35733848 PMCID: PMC9207300 DOI: 10.1016/j.isci.2022.104444] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 04/27/2022] [Accepted: 05/16/2022] [Indexed: 11/27/2022] Open
Abstract
Skeletal muscle stem cells, or satellite cells (SCs), are essential to regenerate and maintain muscle. Quiescent SCs reside in an asymmetric niche between the basal lamina and myofiber membrane. To repair muscle, SCs activate, proliferate, and differentiate, fusing to repair myofibers or reacquiring quiescence to replenish the SC niche. Little is known about when SCs reacquire quiescence during regeneration or the cellular processes that direct SC fate decisions. We find that most SCs reacquire quiescence 5–10 days after muscle injury, following differentiation and fusion of most cells to regenerate myofibers. Single-cell sequencing of myogenic cells in regenerating muscle identifies SCs reacquiring quiescence and reveals that noncell autonomous signaling networks influence SC fate decisions during regeneration. SC transplantation experiments confirm that the regenerating environment influences SC fate. We define a window for SC repopulation of the niche, emphasizing the temporal contribution of the regenerative muscle environment on SC fate. Satellite cells primarily produce myonuclei in the first 4 days following injury Most satellite cells reacquire quiescence 5–7 days following injury Asymmetric division pathways are elevated in satellite cells reacquiring quiescence The regenerating muscle environment directs satellite cell fate decisions
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Affiliation(s)
- Alicia A. Cutler
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Bradley Pawlikowski
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80217, USA
| | - Joshua R. Wheeler
- Departments of Pathology and Neuropathology, Stanford University, Palo Alto, CA 94305, USA
| | - Nicole Dalla Betta
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Tiffany Elston
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
| | - Rebecca O’Rourke
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80217, USA
| | - Kenneth Jones
- Department of Pediatrics, Section of Developmental Biology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80217, USA
| | - Bradley B. Olwin
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA
- Corresponding author
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Stather P, Salji M, Hassan SU, Abbas M, Ahmed A, Mills H, Elston T, Backhouse C, Howard A, Choksy S. A comparison of airborne bacterial fallout between orthopaedic and vascular surgery. Ann R Coll Surg Engl 2016; 99:295-298. [PMID: 27869495 DOI: 10.1308/rcsann.2016.0352] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUCTION The objective of the study was to compare bacterial fallout during vascular prosthesis insertion and orthopaedic major joint replacement performed in conventional and laminar flow ventilation, respectively. MATERIALS AND METHODS A prospective single-centre case control study of 21 consecutive elective vascular procedures involving prosthetic graft insertion and 24 consecutive elective orthopaedic major joint replacements were tested for degree of bacterial fallout using agar settle plates. Preparation time, waiting time and total procedure duration were collected at the time of surgery, and bacterial colony counts on the agar settle plates from airborne bacterial fallout were counted after an incubation period. RESULTS Bacterial fallout count in vascular prosthetic graft insertion was 15-fold greater than in orthopaedic prosthetic joint insertion (15, (IQR 15) vs 1, (IQR 3) respectively, P < 0.0001, Wilcoxon). Waiting time and patient transfer did not significantly increase bacterial fallout counts during the procedure (P = 0.9). CONCLUSIONS Vascular surgical theatres have significantly higher bacterial fallout compared with orthopaedic theatres. This may be partly explained by orthopaedic surgery being routinely performed in laminar flow ventilation, a practice which has not been widely adopted for vascular surgery, in which prosthetic infection may also result in significant mortality and morbidity.
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Affiliation(s)
- P Stather
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - M Salji
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - S-U Hassan
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - M Abbas
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - A Ahmed
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - H Mills
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - T Elston
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - C Backhouse
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - A Howard
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
| | - S Choksy
- Colchester Hospital University NHS Foundation Trust, Colchester , Essex , UK
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Belt PJ, Smithers M, Elston T. The triad of bilateral retinoblastoma, dysplastic naevus syndrome and multiple cutaneous malignant melanomas: a case report and review of the literature. Melanoma Res 2002; 12:179-82. [PMID: 11930116 DOI: 10.1097/00008390-200204000-00012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
We report a case of a patient with the triad of retinoblastoma, dysplastic naevus syndrome (DNS) and multiple cutaneous melanomas. The combination of retinoblastoma and DNS is a significant risk factor for the development of cutaneous melanoma. This risk extends to family members. We recommend that survivors of (inherited) retinoblastoma and their relatives are closely screened for the presence of dysplastic naevi.
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Affiliation(s)
- P J Belt
- Department of Plastic and Reconstructive Surgery, University of Queensland, Princess Alexandra Hospital, Brisbane, Queensland, Australia.
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Abstract
RNA polymerase (RNAP) is a processive molecular motor capable of generating forces of 25-30 pN, far in excess of any other known ATPase. This force derives from the hydrolysis free energy of nucleotides as they are incorporated into the growing RNA chain. The velocity of procession is limited by the rate of pyrophosphate release. Here we demonstrate how nucleotide triphosphate binding free energy can rectify the diffusion of RNAP, and show that this is sufficient to account for the quantitative features of the measured load-velocity curve. Predictions are made for the effect of changing pyrophosphate and nucleotide concentrations and for the statistical behavior of the system.
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Affiliation(s)
- H Y Wang
- Department of Molecular and Cellular Biology, University of California, Berkeley 94720-3112, USA
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Abstract
Mitochondria, bacteria and chloroplasts use the free energy stored in transmembrane ion gradients to manufacture ATP by the action of ATP synthase. This enzyme consists of two principal domains. The asymmetric membrane-spanning F0 portion contains the proton channel, and the soluble F1 portion contains three catalytic sites which cooperate in the synthetic reactions. The flow of protons through F0 is thought to generate a torque which is transmitted to F1 by an asymmetric shaft, the coiled-coil gamma-subunit. This acts as a rotating 'cam' within F1, sequentially releasing ATPs from the three active sites. The free-energy difference across the inner membrane of mitochondria and bacteria is sufficient to produce three ATPs per twelve protons passing through the motor. It has been suggested that this proton motive force biases the rotor's diffusion so that F0 constitutes a rotary motor turning the gamma shaft. Here we show that biased diffusion, augmented by electrostatic forces, does indeed generate sufficient torque to account for ATP production. Moreover, the motor's reversibility-supplying torque from ATP hydrolysis in F1 converts the motor into an efficient proton pump-can also be explained by our model.
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Affiliation(s)
- T Elston
- Department of Molecular and Cellular Biology, University of California, Berkeley 94720-3112, USA
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Elston T, Rodan H, Flemming D, Ford RB, Hustead DR, Richards JR, Rosen DK, Scherk-Nixon MA, Scott PW. 1998 report of the American Association of Feline Practitioners and Academy of Feline Medicine Advisory Panel on Feline Vaccines. J Am Vet Med Assoc 1998; 212:227-41. [PMID: 9448828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Affiliation(s)
- T Elston
- T.H.E. Cat Hospital of Irvine, CA 92604, USA
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Abstract
Morphological data suggest that Golgi cisternae form at the cis-face of the stack and then progressively mature into trans-cisternae. However, other studies indicate that COPI vesicles transport material between Golgi cisternae. These two observations can be reconciled by assuming that cisternae carry secretory cargo through the stack in the anterograde direction, while COPI vesicles transport Golgi enzymes in the retrograde direction. This model provides a mechanism for cisternal maturation. If Golgi enzymes compete with one another for packaging into COPI vesicles, we can account for the asymmetric distribution of enzymes across the stack.
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Affiliation(s)
- B S Glick
- Department of Molecular Genetics and Cell Biology, The University of Chicago, IL 60637, USA.
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Perry GJ, Elston T, Khouri NA, Chan TM, Cameron JS, Frampton G. Antiendothelial cell antibodies in lupus: correlations with renal injury and circulating markers of endothelial damage. Q J Med 1993; 86:727-34. [PMID: 8265773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Systemic lupus erythematosus is characterized by the production of a broad spectrum of autoantibodies. Autoantibodies directed against endothelial cells (AECA) have been particularly well documented. We investigated associations between such antibodies, double-stranded DNA (dsDNAb), phospholipid (cardiolipin, ACA), and indices of activity and chronicity scored on renal biopsy specimens from 22 patients with acute lupus. AECA were present in 73% of these patients, and both the percentage of patients with AECA and the mean antibody titre fell significantly as patients entered remission. When patients already on immunosuppressive therapy were excluded from analysis (n = 7), only levels of AECA and DNAb (p = 0.02) correlated with histological evidence of active lesions and the presence of glomerular epithelial cell crescents; no correlation was found with chronic changes in the renal biopsies. Serum von Willebrand factor (vWf) and serum total protein S levels, two parameters reflecting endothelial cell function, were also measured during acute disease and remission. vWf concentrations were elevated during acute disease (m = 1.9 IU/ml, p = 0.02), but the values did not correlate with AECA titres. In contrast, total protein S levels were reduced (0.81 IU/ml vs. 0.97 IU/ml, p = 0.01) during active disease, but remained within the normal range (0.56-1.16 IU/ml). Furthermore, protein S levels were inversely related to levels of AECA (r = -0.4, p = 0.01). AECA were therefore present in most patients with acute lupus nephritis and were associated with histological evidence of active renal injury and serological evidence of endothelial cell dysfunction. These data provide indirect support for a pathogenic role for AECA in lupus nephritis.
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Affiliation(s)
- G J Perry
- Renal Laboratory, Guy's Hospital, UMDS, London, UK
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Abstract
This paper, following a brief historical note, reviews the literature on anorexia nervosa. It begins by describing the characteristics of the syndrome and then considers incidence, aetiology and treatment. The results of treatment are described and the paper concludes by attempting a prognosis for those who are diagnosed anorexic. The authors are eclectic in their literature survey and also present some experience collected in a hospital school. The paper is intended as a teaching synthesis for clinicians new to this area or for those seeking a brief introduction to the present 'state of the art' in theory and practice.
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