1
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Parham LR, Williams PA, Katada K, Nettleford SK, Chatterji P, Acheampong KK, Danan CH, Ma X, Simon LA, Naughton KE, Mizuno R, Karakasheva T, McMillan EA, Whelan KA, Brady DC, Shaffer SM, Hamilton KE. IGF2BP1/IMP1 Deletion Enhances a Facultative Stem Cell State via Regulation of MAP1LC3B. Cell Mol Gastroenterol Hepatol 2023; 17:439-451. [PMID: 38081361 PMCID: PMC10835461 DOI: 10.1016/j.jcmgh.2023.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 11/30/2023] [Accepted: 12/04/2023] [Indexed: 01/02/2024]
Abstract
BACKGROUND & AIMS The intestinal epithelium interfaces with a diverse milieu of luminal contents while maintaining robust digestive and barrier functions. Facultative intestinal stem cells are cells that survive tissue injury and divide to re-establish the epithelium. Prior studies have shown autophagic state as functional marker of facultative intestinal stem cells, but regulatory mechanisms are not known. The current study evaluated a post-transcriptional regulation of autophagy as an important factor for facultative stem cell state and tissue regeneration. METHODS We evaluated stem cell composition, autophagic vesicle content, organoid formation, and in vivo regeneration in mice with intestinal epithelial deletion of the RNA binding protein IGF2 messenger RNA binding protein 1 (IMP1). The contribution of autophagy to resulting in vitro and in vivo phenotypes was evaluated via genetic inactivation of Atg7. Molecular analyses of IMP1 modulation of autophagy at the protein and transcript localization levels were performed using IMP1 mutant studies and single-molecule fluorescent in situ hybridization. RESULTS Epithelial Imp1 deletion reduced leucine rich repeat containing G protein coupled receptor 5 cell frequency but enhanced both organoid formation efficiency and in vivo regeneration after irradiation. We confirmed prior studies showing increased autophagy with IMP1 deletion. Deletion of Atg7 reversed the enhanced regeneration observed with Imp1 deletion. IMP1 deletion or mutation of IMP1 phosphorylation sites enhanced expression of essential autophagy protein microtubule-associated protein 1 light chain 3β. Furthermore, immunofluorescence imaging coupled with single-molecule fluorescent in situ hybridization showed IMP1 colocalization with MAP1LC3B transcripts at homeostasis. Stress induction led to decreased colocalization. CONCLUSIONS Depletion of IMP1 enhances autophagy, which promotes intestinal regeneration via expansion of facultative intestinal stem cells.
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Affiliation(s)
- Louis R Parham
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Patrick A Williams
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Kay Katada
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Shaneice K Nettleford
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Priya Chatterji
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Kofi K Acheampong
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Charles H Danan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Xianghui Ma
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Lauren A Simon
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Kaitlyn E Naughton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Rei Mizuno
- Department of Surgery, Uji-Tokushukai Medical Center, Uji, Kyoto, Japan
| | - Tatiana Karakasheva
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Emily A McMillan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Kelly A Whelan
- Department of Pathology and Laboratory Medicine, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania; Fels Institute for Cancer Research and Molecular Biology, Lewis Katz School of Medicine at Temple University, Philadelphia, Pennsylvania
| | - Donita C Brady
- Department of Cancer Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Abramson Family Cancer Research Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sydney M Shaffer
- Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania; Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Kathryn E Hamilton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania.
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2
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Danan CH, Naughton KE, Hayer KE, Vellappan S, McMillan EA, Zhou Y, Matsuda R, Nettleford SK, Katada K, Parham LR, Ma X, Chowdhury A, Wilkins BJ, Shah P, Weitzman MD, Hamilton KE. Intestinal transit-amplifying cells require METTL3 for growth factor signaling and cell survival. JCI Insight 2023; 8:e171657. [PMID: 37883185 PMCID: PMC10795831 DOI: 10.1172/jci.insight.171657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 10/25/2023] [Indexed: 10/27/2023] Open
Abstract
Intestinal epithelial transit-amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite these cells' critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit-amplifying cell function. We report that RNA methyltransferase-like 3 (METTL3) is required for survival of transit-amplifying cells in the murine small intestine. Transit-amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Sequencing of polysome-bound and methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation verified a relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit-amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine with important implications for both homeostatic tissue renewal and epithelial regeneration.
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Affiliation(s)
- Charles H. Danan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
- Medical Scientist Training Program, Perelman School of Medicine; and
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kaitlyn E. Naughton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
| | - Katharina E. Hayer
- Department of Biomedical and Health Informatics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
- Division of Protective Immunity, Children’s Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sangeevan Vellappan
- Waksman Institute of Microbiology and
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
- Human Genetics Institute of New Jersey, Piscataway, New Jersey, USA
| | - Emily A. McMillan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
| | - Yusen Zhou
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
- Department of Biomedical and Health Informatics, Children’s Hospital of Philadelphia, Philadelphia, Pennsylvania, USA
| | - Rina Matsuda
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Pathobiology, School of Veterinary Medicine, and
| | - Shaneice K. Nettleford
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
| | - Kay Katada
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Louis R. Parham
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Xianghui Ma
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
| | - Afrah Chowdhury
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
| | - Benjamin J. Wilkins
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Premal Shah
- Department of Genetics, Rutgers University, Piscataway, New Jersey, USA
- Human Genetics Institute of New Jersey, Piscataway, New Jersey, USA
| | - Matthew D. Weitzman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Division of Protective Immunity, Children’s Hospital of Philadelphia Research Institute, Philadelphia, Pennsylvania, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kathryn E. Hamilton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children’s Hospital of Philadelphia, Perelman School of Medicine
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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3
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Williams PA, Naughton KE, Simon LA, Soto GE, Parham LR, Ma X, Danan CH, Hu W, Friedman ES, McMillan EA, Mehta H, Stoltz MA, Ocaña JS, Zackular JP, Bittinger K, Whelan KA, Karakasheva TA, Hamilton KE. Intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction. Am J Physiol Gastrointest Liver Physiol 2023; 324:G354-G368. [PMID: 36852920 PMCID: PMC10069975 DOI: 10.1152/ajpgi.00248.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2022] [Revised: 01/30/2023] [Accepted: 02/16/2023] [Indexed: 03/01/2023]
Abstract
Calorie restriction can enhance the regenerative capacity of the injured intestinal epithelium. Among other metabolic changes, calorie restriction can activate the autophagy pathway. Although independent studies have attributed the regenerative benefit of calorie restriction to downregulation of mTORC1, it is not known whether autophagy itself is required for the regenerative benefit of calorie restriction. We used mouse and organoid models with autophagy gene deletion to evaluate the contribution of autophagy to intestinal epithelial regeneration following calorie restriction. In the absence of injury, mice with intestinal epithelial-specific deletion of autophagy gene Atg7 (Atg7ΔIEC) exhibit weight loss and histological changes similar to wild-type mice following calorie restriction. Conversely, calorie-restricted Atg7ΔIEC mice displayed a significant reduction in regenerative crypt foci after irradiation compared with calorie-restricted wild-type mice. Targeted analyses of tissue metabolites in calorie-restricted mice revealed an association between calorie restriction and reduced glycocholic acid (GCA) in wild-type mice but not in Atg7ΔIEC mice. To evaluate whether GCA can directly modulate epithelial stem cell self-renewal, we performed enteroid formation assays with or without GCA. Wild-type enteroids exhibited reduced enteroid formation efficiency in response to GCA treatment, suggesting that reduced availability of GCA during calorie restriction may be one mechanism by which calorie restriction favors epithelial regeneration in a manner dependent upon epithelial autophagy. Taken together, our data support the premise that intestinal epithelial Atg7 is required for the regenerative benefit of calorie restriction, due in part to its role in modulating luminal GCA with direct effects on epithelial stem cell self-renewal.NEW & NOTEWORTHY Calorie restriction is associated with enhanced intestinal regeneration after irradiation, but the requirement of autophagy for this process is not known. Our data support the premise that intestinal epithelial autophagy is required for the regenerative benefit of calorie restriction. We also report that luminal levels of primary bile acid glycocholic acid are modulated by epithelial cell autophagy during calorie restriction with direct effects on epithelial stem cell function.
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Affiliation(s)
- Patrick A Williams
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kaitlyn E Naughton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Lauren A Simon
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Gloria E Soto
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Louis R Parham
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Xianghui Ma
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Charles H Danan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Weiming Hu
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Elliot S Friedman
- Division of Gastroenterology and Hepatology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Emily A McMillan
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Hritik Mehta
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Madison A Stoltz
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Joshua Soto Ocaña
- Division of Protective Immunity, Children's Hospital of Philadelphia, Pennsylvania United States
| | - Joseph P Zackular
- Division of Protective Immunity, Children's Hospital of Philadelphia, Pennsylvania United States
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kyle Bittinger
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kelly A Whelan
- Department of Pathology & Laboratory Medicine, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States
- Fels Institute for Cancer Research & Molecular Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania, United States
| | - Tatiana A Karakasheva
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
| | - Kathryn E Hamilton
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Pediatrics, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States
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4
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Danan CH, Naughton KE, Hayer KE, Vellappan S, McMillan EA, Zhou Y, Matsuda R, Nettleford SK, Katada K, Parham LR, Ma X, Chowdhury A, Wilkins BJ, Shah P, Weitzman MD, Hamilton KE. Intestinal transit amplifying cells require METTL3 for growth factor signaling, KRAS expression, and cell survival. bioRxiv 2023:2023.04.06.535853. [PMID: 37066277 PMCID: PMC10104132 DOI: 10.1101/2023.04.06.535853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
Intestinal epithelial transit amplifying cells are essential stem progenitors required for intestinal homeostasis, but their rapid proliferation renders them vulnerable to DNA damage from radiation and chemotherapy. Despite their critical roles in intestinal homeostasis and disease, few studies have described genes that are essential to transit amplifying cell function. We report that the RNA methyltransferase, METTL3, is required for survival of transit amplifying cells in the murine small intestine. Transit amplifying cell death after METTL3 deletion was associated with crypt and villus atrophy, loss of absorptive enterocytes, and uniform wasting and death in METTL3-depleted mice. Ribosome profiling and sequencing of methylated RNAs in enteroids and in vivo demonstrated decreased translation of hundreds of unique methylated transcripts after METTL3 deletion, particularly transcripts involved in growth factor signal transduction such as Kras. Further investigation confirmed a novel relationship between METTL3 and Kras methylation and protein levels in vivo. Our study identifies METTL3 as an essential factor supporting the homeostasis of small intestinal tissue via direct maintenance of transit amplifying cell survival. We highlight the crucial role of RNA modifications in regulating growth factor signaling in the intestine, with important implications for both homeostatic tissue renewal and epithelial regeneration.
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Affiliation(s)
- Charles H. Danan
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Medical Scientist Training Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kaitlyn E. Naughton
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Katharina E. Hayer
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Division of Protective Immunity, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Sangeevan Vellappan
- Waksman Institute of Microbiology, Rutgers University, Piscataway, NJ, 08854, USA
- Department of Genetics, Rutgers University, Piscataway, NJ, 08854, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ, 08854, USA
| | - Emily A. McMillan
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yusen Zhou
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Biomedical and Health Informatics, The Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Rina Matsuda
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Shaneice K. Nettleford
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kay Katada
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Louis R. Parham
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Xianghui Ma
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Afrah Chowdhury
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Benjamin J. Wilkins
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Premal Shah
- Department of Genetics, Rutgers University, Piscataway, NJ, 08854, USA
- Human Genetics Institute of New Jersey, Piscataway, NJ, 08854, USA
| | - Matthew D. Weitzman
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Division of Protective Immunity, Children’s Hospital of Philadelphia, Philadelphia, PA, 19104, USA
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine; University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Kathryn E. Hamilton
- Division of Gastroenterology, Hepatology, and Nutrition; Department of Pediatrics; Children’s Hospital of Philadelphia; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA
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5
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Cho S, Hiott LM, McDonald JM, Barrett JB, McMillan EA, House SL, Adams ES, Frye JG, Jackson CR. Diversity and antimicrobial resistance of Enterococcus from the Upper Oconee Watershed, Georgia. J Appl Microbiol 2020; 128:1221-1233. [PMID: 31834656 DOI: 10.1111/jam.14550] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 11/15/2019] [Accepted: 12/03/2019] [Indexed: 01/01/2023]
Abstract
AIM It is well-known that enterococci are abundant in the environment; however, the role of surface water as a reservoir of antimicrobial-resistant enterococci remains largely undefined. In this study, surface water samples were collected over a 2-year period from the Upper Oconee watershed, Athens, GA to examine enterococci and their antimicrobial resistance. METHODS AND RESULTS Approximately 97% (445/458) of the samples were positive for enterococci and a total of 637 enterococci were isolated. The predominant species were Enterococcus casseliflavus (33·6%) followed by Enterococcus faecalis (26·5%) and Enterococcus hirae (13·2%). Regardless of species, the highest levels of resistance were to lincomycin (88·5%) and tetracycline (13%); isolates also exhibited resistance to newer antimicrobials, daptomycin (8·9%) and tigecycline (6·4%). Multidrug resistance (resistance ≥3 antimicrobial classes) was observed to as many as five classes of antimicrobials. Resistant enterococci appeared to be randomly dispersed over the seasons rather than clustered by species or antimicrobial resistance. CONCLUSIONS This study demonstrated that surface waters contain a large population of diverse species of antimicrobial-resistant enterococci, including resistance to new antimicrobials. SIGNIFICANCE AND IMPACT OF THE STUDY These results may indicate the potential of human intestinal illness and/or colonization of the human gut with resistant enterococci as enterococci correlate with increased disease risk to humans during recreational exposure to water.
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Affiliation(s)
- S Cho
- Department of Microbiology, University of Georgia, Athens, GA, USA
| | - L M Hiott
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
| | - J M McDonald
- Lewis F. Rogers Institute for Environmental and Spatial Analysis, University of North Georgia, Oakwood, GA, USA
| | - J B Barrett
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
| | - E A McMillan
- Department of Microbiology, University of Georgia, Athens, GA, USA
| | - S L House
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
| | - E S Adams
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
| | - J G Frye
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
| | - C R Jackson
- Bacterial Epidemiology and Antimicrobial Resistance Research Unit, USDA-ARS Russell Research Center, Athens, GA, USA
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6
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Williams PA, Kobilnyk HE, McMillan EA, Strochlic TI. MAPKAP kinase 2-mediated phosphorylation of HspA1L protects male germ cells from heat stress-induced apoptosis. Cell Stress Chaperones 2019; 24:1127-1136. [PMID: 31642047 PMCID: PMC6882973 DOI: 10.1007/s12192-019-01035-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 08/29/2019] [Accepted: 09/12/2019] [Indexed: 12/19/2022] Open
Abstract
Developing male germ cells are extremely sensitive to heat stress; consequently, anatomic and physiologic adaptations have evolved to maintain proper thermoregulation during mammalian spermatogenesis. At the cellular level, increased expression and activity of HSP70 family members occur in response to heat stress in order to refold partially denatured proteins and restore function. In addition, several kinase-mediated signaling pathways are activated in the testis upon hyperthermia. The p38 MAP kinase (MAPK) pathway plays an important role in mitigating heat stress, and recent findings have implicated the downstream p38 substrate, MAPKAP kinase 2 (MK2), in this process. However, the precise function that this kinase plays in spermatogenesis is not completely understood. Using a proteomics-based screen, we identified and subsequently validated that the testis-enriched HSP70 family member, HspA1L, is a novel substrate of MK2. We demonstrate that MK2 phosphorylates HspA1L solely on Ser241, a residue within the N-terminal nucleotide-binding domain of the enzyme. This phosphorylation event enhances the chaperone activity of HspA1L in vitro and renders male germ cells more resistant to heat stress-induced apoptosis. Taken together, these findings illustrate a novel stress-induced signaling cascade that promotes the chaperone activity of HspA1L with implications for understanding male reproductive biology.
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Affiliation(s)
- Patrick A Williams
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th St., MS 497, Philadelphia, PA, 19102, USA
| | - Heather E Kobilnyk
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th St., MS 497, Philadelphia, PA, 19102, USA
| | - Emily A McMillan
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th St., MS 497, Philadelphia, PA, 19102, USA
| | - Todd I Strochlic
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, 245 N. 15th St., MS 497, Philadelphia, PA, 19102, USA.
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7
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Abstract
The study of kinase-substrate relationships is essential to gain a complete understanding of the functions of these enzymes and their downstream targets in both physiological and pathological states. CK2 is an evolutionarily conserved serine/threonine kinase with a growing list of hundreds of substrates involved in multiple cellular processes. Due to its pleiotropic properties, identifying and characterizing a comprehensive set of CK2 substrates has been particularly challenging and remains a hurdle in the study of this important enzyme. To address this challenge, we have devised a versatile experimental strategy that enables the targeted enrichment and identification of putative CK2 substrates. This protocol takes advantage of the unique dual co-substrate specificity of CK2 allowing for specific thiophosphorylation of its substrates in a cell or tissue lysate. These substrate proteins are subsequently alkylated, immunoprecipitated, and identified by liquid chromatography/tandem mass spectrometry (LC-MS/MS). We have previously used this approach to successfully identify CK2 substrates from Drosophila ovaries and here we extend the application of this protocol to human glioblastoma cells, illustrating the adaptability of this method to investigate the biological roles of this kinase in various model organisms and experimental systems.
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Affiliation(s)
- John E Chojnowski
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine
| | - Emily A McMillan
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine
| | - Todd I Strochlic
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine;
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8
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McMillan EA, Longo SM, Smith MD, Broskin S, Lin B, Singh NK, Strochlic TI. The protein kinase CK2 substrate Jabba modulates lipid metabolism during Drosophila oogenesis. J Biol Chem 2018; 293:2990-3002. [PMID: 29326167 DOI: 10.1074/jbc.m117.814657] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 01/07/2018] [Indexed: 11/06/2022] Open
Abstract
Lipid metabolism plays a critical role in female reproduction. During oogenesis, maturing oocytes accumulate high levels of neutral lipids that are essential for both energy production and the synthesis of other lipid molecules. Metabolic pathways within the ovary are partially regulated by protein kinases that link metabolic status to oocyte development. Although the functions of several kinases in this process are well established, the roles that many other kinases play in coordinating metabolic state with female germ cell development are unknown. Here, we demonstrate that the catalytic activity of casein kinase 2 (CK2) is essential for Drosophila oogenesis. Using an unbiased biochemical screen that leveraged an unusual catalytic property of the kinase, we identified a novel CK2 substrate in the Drosophila ovary, the lipid droplet-associated protein Jabba. We show that Jabba is essential for modulating ovarian lipid metabolism and for regulating female fertility in the fly. Our findings shed light on a CK2-dependent signaling pathway governing lipid metabolism in the ovary and provide insight into the long-recognized but poorly understood association between energy metabolism and female reproduction.
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Affiliation(s)
- Emily A McMillan
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Sheila M Longo
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Michael D Smith
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Sarah Broskin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Baicheng Lin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Nisha K Singh
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102
| | - Todd I Strochlic
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, Pennsylvania 19102.
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9
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Williams PA, Krug MS, McMillan EA, Peake JD, Davis TL, Cocklin S, Strochlic TI. Phosphorylation of the RNA-binding protein Dazl by MAPKAP kinase 2 regulates spermatogenesis. Mol Biol Cell 2016; 27:2341-50. [PMID: 27280388 PMCID: PMC4966976 DOI: 10.1091/mbc.e15-11-0773] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2016] [Accepted: 06/03/2016] [Indexed: 01/28/2023] Open
Abstract
Developing male germ cells are exquisitely sensitive to stress and rely on RNA-binding proteins for posttranscriptional gene expression. Phosphorylation of the germ cell–specific RNA-binding protein deleted in azoospermia-like (Dazl) by the stress-activated protein kinase MK2 is a negative regulator of spermatogenesis. Developing male germ cells are exquisitely sensitive to environmental insults such as heat and oxidative stress. An additional characteristic of these cells is their unique dependence on RNA-binding proteins for regulating posttranscriptional gene expression and translational control. Here we provide a mechanistic link unifying these two features. We show that the germ cell–specific RNA-binding protein deleted in azoospermia-like (Dazl) is phosphorylated by MAPKAP kinase 2 (MK2), a stress-induced protein kinase activated downstream of p38 MAPK. We demonstrate that phosphorylation of Dazl by MK2 on an evolutionarily conserved serine residue inhibits its interaction with poly(A)-binding protein, resulting in reduced translation of Dazl-regulated target RNAs. We further show that transgenic expression of wild-type human Dazl but not a phosphomimetic form in the Drosophila male germline can restore fertility to flies deficient in boule, the Drosophila orthologue of human Dazl. These results illuminate a novel role for MK2 in spermatogenesis, expand the repertoire of RNA-binding proteins phosphorylated by this kinase, and suggest that signaling by the p38-MK2 pathway is a negative regulator of spermatogenesis via phosphorylation of Dazl.
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Affiliation(s)
- Patrick A Williams
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Michael S Krug
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Emily A McMillan
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Jasmine D Peake
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Tara L Davis
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Simon Cocklin
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
| | - Todd I Strochlic
- Department of Biochemistry and Molecular Biology, Drexel University College of Medicine, Philadelphia, PA 19102
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Singh L, Brennan TA, Kim JH, Egan KP, McMillan EA, Chen Q, Hankenson KD, Zhang Y, Emerson SG, Johnson FB, Pignolo RJ. Long-term functional engraftment of mesenchymal progenitor cells in a mouse model of accelerated aging. Stem Cells 2014. [PMID: 23193076 DOI: 10.1002/stem.1294] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Age-related osteoporosis is characterized by a decrease in bone-forming capacity mediated by defects in the number and function of osteoblasts. An important cellular mechanism that may in part explain osteoblast dysfunction that occurs with aging is senescence of mesenchymal progenitor cells (MPCs). In the telomere-based Wrn(-/-) Terc(-/-) model of accelerated aging, the osteoporotic phenotype of these mice is also associated with a major decline in MPC differentiation into osteoblasts. To investigate the role of MPC aging as a cell-autonomous mechanism in senile bone loss, transplantation of young wild-type whole bone marrow into Wrn(-/-) Terc(-/-) mutants was performed and the ability of engrafted cells to differentiate into cells of the osteoblast lineage was assessed. We found that whole bone marrow transplantation in Wrn(-/-) Terc(-/-) mice resulted in functional engraftment of MPCs up to 42 weeks, which was accompanied by a survival advantage as well as delays in microarchitectural features of skeletal aging.
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Affiliation(s)
- Lakshman Singh
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Pignolo RJ, Suda RK, McMillan EA, Shen J, Lee SH, Choi Y, Wright AC, Johnson FB. Defects in telomere maintenance molecules impair osteoblast differentiation and promote osteoporosis. Aging Cell 2008; 7:23-31. [PMID: 18028256 DOI: 10.1111/j.1474-9726.2007.00350.x] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Osteoporosis and the associated risk of fracture are major clinical challenges in the elderly. Telomeres shorten with age in most human tissues, including bone, and because telomere shortening is a cause of cellular replicative senescence or apoptosis in cultured cells, including mesenchymal stem cells (MSCs) and osteoblasts, it is hypothesized that telomere shortening contributes to the aging of bone. Osteoporosis is common in the Werner (Wrn) and dyskeratosis congenita premature aging syndromes, which are characterized by telomere dysfunction. One of the targets of the Wrn helicase is telomeric DNA, but the long telomeres and abundant telomerase in mice minimize the need for Wrn at telomeres, and thus Wrn knockout mice are relatively healthy. In a model of accelerated aging that combines the Wrn mutation with the shortened telomeres of telomerase (Terc) knockout mice, synthetic defects in proliferative tissues result. Here, we demonstrate that deficiencies in Wrn-/- Terc-/- mutant mice cause a low bone mass phenotype, and that age-related osteoporosis is the result of impaired osteoblast differentiation in the context of intact osteoclast differentiation. Further, MSCs from single and Wrn-/- Terc-/- double mutant mice have a reduced in vitro lifespan and display impaired osteogenic potential concomitant with characteristics of premature senescence. These data provide evidence that replicative aging of osteoblast precursors is an important mechanism of senile osteoporosis.
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Affiliation(s)
- Robert J Pignolo
- Department of Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA.
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