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Kamat V, Grumbine MK, Bao K, Mokate K, Khalil G, Cook D, Clearwater B, Hirst R, Harman J, Boeck M, Fu Z, Smith LEH, Goswami M, Wubben TJ, Walker EM, Zhu J, Soleimanpour SA, Scarlett JM, Robbings BM, Hass D, Hurley JB, Sweet IR. A versatile pumpless multi-channel fluidics system for maintenance and real-time functional assessment of tissue and cells. Cell Rep Methods 2023; 3:100642. [PMID: 37963464 PMCID: PMC10694526 DOI: 10.1016/j.crmeth.2023.100642] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 07/24/2023] [Accepted: 10/20/2023] [Indexed: 11/16/2023]
Abstract
To address the needs of the life sciences community and the pharmaceutical industry in pre-clinical drug development to both maintain and continuously assess tissue metabolism and function with simple and rapid systems, we improved on the initial BaroFuse to develop it into a fully functional, pumpless, scalable multi-channel fluidics instrument that continuously measures changes in oxygen consumption and other endpoints in response to test compounds. We and several other laboratories assessed it with a wide range of tissue types including retina, pancreatic islets, liver, and hypothalamus with both aqueous and gaseous test compounds. The setup time was less than an hour for all collaborating groups, and there was close agreement between data obtained from the different laboratories. This easy-to-use system reliably generates real-time metabolic and functional data from tissue and cells in response to test compounds that will address a critical need in basic and applied research.
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Affiliation(s)
- Varun Kamat
- University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA
| | | | - Khang Bao
- EnTox Sciences, Inc., Mercer Island, WA 98040, USA
| | - Kedar Mokate
- University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA
| | - Gamal Khalil
- EnTox Sciences, Inc., Mercer Island, WA 98040, USA
| | - Daniel Cook
- EnTox Sciences, Inc., Mercer Island, WA 98040, USA
| | | | - Richard Hirst
- Technical Assembly Service Corporation, Seattle, WA 98109, USA
| | - Jarrod Harman
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Myriam Boeck
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Eye Center, Medical Center, Faculty of Medicine, University of Freiburg, Freiburg im Breisgau, Germany
| | - Zhongjie Fu
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lois E H Smith
- Department of Ophthalmology, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Moloy Goswami
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Thomas J Wubben
- Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, MI 48105, USA
| | - Emily M Walker
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 98195, USA
| | - Jie Zhu
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 98195, USA
| | - Scott A Soleimanpour
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 98195, USA
| | - Jarrad M Scarlett
- University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Pediatric Gastroenterology and Hepatology, Seattle Children's Hospital, Seattle, WA 98145, USA
| | - Brian M Robbings
- University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; Department of Biochemistry, University of Washington, Seattle, WA 98109, USA
| | - Daniel Hass
- Department of Biochemistry, University of Washington, Seattle, WA 98109, USA
| | - James B Hurley
- Department of Biochemistry, University of Washington, Seattle, WA 98109, USA
| | - Ian R Sweet
- University of Washington Medicine Diabetes Institute, University of Washington, Seattle, WA 98109, USA; EnTox Sciences, Inc., Mercer Island, WA 98040, USA.
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Regan SN, Dykstra MP, Yin H, McLaughlin PW, Boike TP, Bhatt AK, Walker EM, Zaki M, Kendrick D, Mislmani M, Paluch S, Litzenberg DW, Mietzel M, Narayana V, Smith A, Jackson WC, Heimburger DK, Schipper M, Dess RT. ADT Use and Nodal Irradiation in Men Receiving Post-Prostatectomy Salvage Radiotherapy within a Statewide Radiation Oncology Quality Consortium. Int J Radiat Oncol Biol Phys 2023; 117:e430-e431. [PMID: 37785407 DOI: 10.1016/j.ijrobp.2023.06.1596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) For men with biochemical recurrence after radical prostatectomy, salvage radiotherapy (SRT) is a standard of care. Outcomes are improved when SRT is delivered at lower PSA levels, and there has been increased emphasis on more timely treatment. With early SRT, however, there remains uncertainty as to the optimal use and duration of androgen deprivation therapy (ADT) and pelvic lymph node radiation (PLNRT). Moreover, PET imaging and genomic classifiers have emerged as tools to guide treatment decisions, but their uptake in routine practice is unknown. To address these questions, we analyzed a contemporary cohort treated with SRT within the Michigan Radiation Oncology Quality Consortium (MROQC). We hypothesized that ADT and PLNRT practices would reflect recent trial results in this setting. MATERIALS/METHODS Eligible patients receiving SRT at an MROQC center were enrolled from 06/09/20 to 11/04/22. Data was prospectively collected via patient-, physician-, and physicist-completed forms. Patients were matched to the Michigan Urological Surgery Improvement Collaborative (MUSIC) database for additional treatment- and patient-related data. Univariable (UVA) and multivariable analyses (MVA) were performed to test associations between patient/tumor factors and ADT or PLNRT use. RESULTS A total of 191 patients across 26 centers were enrolled in the MROQC database. Of these, 116 were matched to the MUSIC database. Median time from RP to SRT was 17 months (IQR 8 - 33 months). The median post-RP PSA prior to SRT was 0.25 (IQR 0.16 - 0.60). Early SRT was defined as pre-SRT PSA ≤0.5, and 27% (n = 31/116) had a pre-SRT PSA >0.5. Twenty-eight were pT3b/T4, 97% were pN0/NX, and 51% had positive surgical margins. Fractionation was conventional (>28 fractions) in 58% and moderate hypofractionation (20-28 fractions) in 38%. Table 1 describes the patients receiving ADT and/or PLNRT. Median ADT duration was 6 mo (IQR 6 - 7 mo). MVA revealed pre-SRT PSA >0.5 (OR 5.05 [1.89 - 15.33]) and pT3b/T4 disease (OR 4.23 [1.40 - 14.56]) were significantly associated with ADT use (p <0.05), but not grade group (GG) or margin status. PLNRT was significantly associated with pre-SRT PSA >0.5 (OR 3.04 [1.21 - 8.42], p <0.05) but not pT stage, margin status, or GG. PET imaging was performed in 37% of men (52% negative, 21% prostate bed alone uptake, and 26% lymph node positivity) and genomic classifiers were performed in 24%. CONCLUSION Nearly 75% of biochemically recurrent prostate cancer patients within MROQC received early SRT, and about half received ADT. A pre-SRT PSA >0.5 was strongly associated with ADT and PLNRT. With prostate bed SRT alone, very few received ADT. Given the considerable heterogeneity in treatment, additional studies may help identify patients who most benefit from ADT + PLNRT, and who may be spared potential added toxicity.
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Affiliation(s)
- S N Regan
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - M P Dykstra
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - H Yin
- University of Michigan, Ann Arbor, MI
| | - P W McLaughlin
- Department of Radiation Oncology, Assarian Cancer Center, Ascension Providence Hospital, Novi, MI
| | - T P Boike
- GenesisCare USA / Michigan Healthcare Professionals, Troy, MI
| | - A K Bhatt
- Karmanos Cancer Institute at McLaren Greater Lansing, Lansing, MI
| | - E M Walker
- Department of Radiation Oncology, Henry Ford Health System, Detroit, MI
| | - M Zaki
- Covenant HealthCare, Saginaw, MI
| | - D Kendrick
- Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - M Mislmani
- University Hospitals - Seidman Cancer Center, Kalamazoo, MI
| | - S Paluch
- Covenant Healthcare, Saginaw, MI
| | | | - M Mietzel
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - V Narayana
- Ascension Providence Hospital, Southfield, MI
| | - A Smith
- University of Michigan, Ann Arbor, MI
| | - W C Jackson
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | | | - M Schipper
- Department of Biostatistics, University of Michigan, Ann Arbor, MI
| | - R T Dess
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Cousins MM, Dykstra MP, Griffith K, Mietzel M, Kendrick D, Trumpower E, Dusseau D, Dominello MM, Boike TP, Hayman JA, Walker EM, Jolly S, Mierzwa ML, Jagsi R, Vicini FA, Pierce LJ. Cannabis Use Patterns among Patients with Early-Stage Breast Cancer in a Large Multicenter Cohort from a State with Legalized Adult Non-Medical Cannabis. Int J Radiat Oncol Biol Phys 2023; 117:e95. [PMID: 37786222 DOI: 10.1016/j.ijrobp.2023.06.858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Cannabis use among patients with cancer is an area of great interest given its widespread acceptance despite the lack of supporting clinical data. The absence of data limits the understanding of potential clinical benefits of cannabis and the ability of providers to deliver evidence-based recommendations for patient care. We explored cannabis use patterns in patients with early-stage breast cancer in a large multicenter cohort in a state with legalized adult non-medical cannabis. MATERIALS/METHODS Initial questions about cannabis use history and frequency were introduced in Michigan Radiation Oncology Quality Consortium (MROQC) breast cancer patient surveys on 2/1/2020 for female patients receiving radiation after lumpectomy for non-metastatic breast cancer. Expanded questions were introduced on 6/28/2022 to assess mode of administration, active ingredient, and reason for use. Summary statistics were generated. A multivariable model using logistic regression identified patient characteristics associated with cannabis use. RESULTS Among 3948 eligible patients, 2738 (69.35%) completed survey questions, and 2462/2738 (89.9%) completed the initial question on cannabis use. Among those, 364/2462 (14.8%) noted cannabis use in the last 30 days, 588 (23.9%) noted remote use (>30 days ago), 1462 (59.4%) reported never having used cannabis, 44 (1.8%) preferred not to answer cannabis use questions, and 4 (0.4%) did not provide use history. Younger age [age <50 vs 60-70, OR 2.5 (95% CI 1.65, 3.79) p<0.001)], Hispanic ethnicity [OR 2.20 (95% CI 1.06, 4.56) p = 0.03], history of smoking [OR 2.56 (95% CI 1.88, 3.48) p<0.001], current smoking [OR 4.70 (95% CI 3.22, 6.86) p<0.001)], and prior chemotherapy [OR 1.40 (95% CI 1.00, 1.96) p = 0.05] predicted recent cannabis use in a multivariable model. Of the 364 patients endorsing cannabis use in the last 30 days, 89 (24.5%), 72 (19.8%), 29 (8.0%), 66 (18.1%), 30 (8.2%), and 78 (21.4%) reported using cannabis 1-2 days, 3-5 days, 6-9 days, 10-19 days, 20-29 days, and all 30 days, respectively. The most common modes of administration among 76 individuals who responded to the expanded questionnaire to date were oral (39.4%), smoking (30.3%), and topical (10.5%). The products used contained tetrahydrocannabinol (THC; 26.3%), cannabidiol (CBD; 19.7%), balanced levels of THC and CBD (19.7%), or active ingredients that were unknown to the patient (34.2%). Patients frequently endorsed cannabis use for insomnia, anxiety, and pain. CONCLUSION Many patients with early-stage breast cancer are using cannabis. Younger age, Hispanic ethnicity, smoking, and chemotherapy history are predictors of cannabis use. Patients are often unaware of the active ingredients in the products that they use, suggesting an important role for patient education and a need to equip providers to advise patients in their care.
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Affiliation(s)
- M M Cousins
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI; Department of Radiation Oncology, Self Regional Healthcare, Greenwood, SC
| | - M P Dykstra
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - K Griffith
- Department of Biostatistics, University of Michigan, Ann Arbor, MI; Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - M Mietzel
- Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - D Kendrick
- Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - E Trumpower
- Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - D Dusseau
- Department of Radiation Oncology, Henry Ford Health System, Jackson, MI
| | - M M Dominello
- Department of Radiation Oncology, Karmanos Cancer Center, Detroit, MI
| | - T P Boike
- Department of Radiation Oncology, GenesisCare, Farmington Hills, MI
| | - J A Hayman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - E M Walker
- Department of Radiation Oncology, Henry Ford Health System, Detroit, MI
| | - S Jolly
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - M L Mierzwa
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - R Jagsi
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI; Department of Radiation Oncology, Emory University, Atlanta, GA
| | - F A Vicini
- Department of Radiation Oncology, GenesisCare, Farmington Hills, MI
| | - L J Pierce
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Dykstra MP, Regan SN, Yin H, McLaughlin PW, Boike TP, Bhatt AK, Walker EM, Zaki M, Kendrick D, Mislmani M, Paluch S, Litzenberg DW, Mietzel M, Narayana V, Smith A, Jackson WC, Heimburger DK, Schipper M, Dess RT. Androgen Deprivation Therapy Use among Intermediate Risk Prostate Cancer Patients Undergoing Radiation Therapy across a Statewide Radiation Oncology Quality Consortium. Int J Radiat Oncol Biol Phys 2023; 117:e380-e381. [PMID: 37785288 DOI: 10.1016/j.ijrobp.2023.06.2491] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) For men with intermediate (INT) risk prostate cancer, the addition of androgen deprivation therapy (ADT) reduces risk of PSA failure, distant metastasis, and cancer-related mortality. Moreover, the relative reduction in cancer-related adverse outcomes with ADT use appears consistent across all INT risk subgroups. The absolute benefit of ADT, however, varies by baseline risk. In contemporary practice, it is unknown which clinical factors are most strongly associated with intended ADT use. Therefore, we sought to identify such factors within the diverse practices of the Michigan Radiation Oncology Quality Consortium (MROQC). MATERIALS/METHODS Patients with localized prostate cancer undergoing definitive radiation therapy were enrolled from 6/9/20 to 11/4/22 (n = 599). Standardized patient, physician, and physicist forms were used to collect baseline and follow-up information. Intended ADT use, defined by the treating physician, was prospectively collected and is the primary outcome of this analysis. Univariable (UVA) and multivariable analyses (MVA) associations with patient (age, race, comorbidities), tumor (T stage, Gleason, percent cores positive, and PSA), and practice-related (academic vs private) factors were performed. In addition, advanced modality testing (PET, MRI, and genomic classifiers) was available as of March 2021, and subgroup analysis were performed where appropriate. RESULTS A total 351 patients across 26 centers were enrolled with INT risk disease. ADT use was intended for 46% of men (n = 162/351) which differed by men with NCCN favorable INT (21%, n = 22/105) vs unfavorable INT risk disease (57%, n = 140/246), p<0.001. Sixty two percent (n = 100/162) had an intended ADT duration of 4-6 months and 21% (n = 34/162) had ≥12 months. Older age was associated with ADT use (70 vs 67, p < 0.01); there were no significant differences by race or comorbidities number. MVA showed Gleason 4+3 (OR 4.61 [2.91 - 7.42]) and > = 50% positive cores (2.56 [1.52 - 4.37]) were significantly associated with ADT use. No significant differences were noted based on practice setting. Pelvic MRI was obtained for 71% of men (n = 197/279), genomic classifiers in 47% (n = 130/279), and PET in 2% (n = 6/282). In the subset with MRI (n = 197), adverse features (ECE, SVI, or equivocal LNs) were associated with intended ADT use (OR 3.0 [1.4 - 7.1]) after adjustment for NCCN favorable/unfavorable INT risk classification. CONCLUSION Within a state-wide consortium, intended ADT use for intermediate prostate cancer is most strongly associated with Gleason score, ≥50% positive cores, NCCN unfavorable intermediate risk classification, and adverse features on MRI. Nearly half of men had genomic classifier testing underscoring the importance ongoing trials such as NRG/GU 010.
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Affiliation(s)
- M P Dykstra
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - S N Regan
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - H Yin
- University of Michigan, Ann Arbor, MI
| | - P W McLaughlin
- Department of Radiation Oncology, Assarian Cancer Center, Ascension Providence Hospital, Novi, MI
| | - T P Boike
- GenesisCare USA / Michigan Healthcare Professionals, Troy, MI
| | - A K Bhatt
- Karmanos Cancer Institute at McLaren Greater Lansing, Lansing, MI
| | - E M Walker
- Department of Radiation Oncology, Henry Ford Health System, Detroit, MI
| | - M Zaki
- Wayne State University School of Medicine, Detroit, MI
| | - D Kendrick
- Michigan Radiation Oncology Quality Consortium Coordinating Center, Ann Arbor, MI
| | - M Mislmani
- University Hospitals - Seidman Cancer Center, Kalamazoo, MI
| | - S Paluch
- Covenant Healthcare, Saginaw, MI
| | | | - M Mietzel
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - V Narayana
- Ascension Providence Hospital, Southfield, MI
| | - A Smith
- University of Michigan, Ann Arbor, MI
| | - W C Jackson
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | | | - M Schipper
- Department of Biostatistics, University of Michigan, Ann Arbor, MI
| | - R T Dess
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Moncion A, Griffith K, Walker EM, Jagsi R, Dominello MM, Wilson M, Mietzel M, Grubb M, Marsh R, Vicini FA, Pierce LJ. Impact of Breast Volume on Achieving a Conservative Heart and Target Coverage Metric for Patients Receiving Whole Breast Radiotherapy in a Statewide Consortium. Int J Radiat Oncol Biol Phys 2023; 117:e193-e194. [PMID: 37784833 DOI: 10.1016/j.ijrobp.2023.06.1061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Radiation to large breast volumes (BV) has been associated with increased dose inhomogeneities, breast fibrosis, and induration. Radiation exposure to the heart during breast radiotherapy has been associated with late cardiovascular morbidity and mortality. This study, therefore, investigates the impact of BV on achieving optimal lumpectomy cavity target coverage (V95% [%] >95) while maintaining mean heart dose constraints (MHD, mean [Gy] <1) across a range of BV from patients enrolled in a statewide consortium. MATERIALS/METHODS A retrospective analysis was conducted for 2,506 patients receiving left-sided whole breast moderately-hypofractionated (2.5-2.8 Gy/fx) radiotherapy without nodal fields between 2018-2022. The BV was calculated for each patient from contours in the treatment planning system, and the volume distribution partitioned into quartiles. Dosimetric parameters were calculated from dose-volume histograms. The percentage of patients in which the metrics were achieved was calculated for each BV quartile for different treatment positions: all positions, supine, supine with breathing motion management, and prone. RESULTS The BV ranges within the quartiles (∼620 patients/quartile) were ≤720.0 cc, 720.1 to ≤1065.0 cc, 1065.1 to ≤1500.0 cc, and >1500.0 cc for quartiles Q1-Q4, respectively. Of the 2,506 patients, 76% were treated supine (of which 41.6% were treated using breathing motion management techniques), 23.5% were treated prone, and 0.5% were treated decubitus. Discrete percentages of patients able to meet the metrics are provided in the table. An increase in BV from Q1 to Q4 correlated with lower percentages of patients meeting the MHD metric, however no correlation was observed between BV and target coverage. Treating supine with breathing motion management resulted in a higher percentage of patients meeting the MHD metric (odds ratio (OR) = 1.96 relative to supine without motion management, p<0.0001), while the prone setup proved to be the superior technique across all quartiles (OR = 3.95 relative to supine, p<0.0001). CONCLUSION Increasing BVs resulted in lower percentages of patients receiving MHD≤1 Gy. Thus, cardiac sparing may be more difficult to achieve in patients with larger BV. Utilization of alternate treatment positions, such as supine with breathing motion management and prone, greatly improved the percentage of patients able to meet the MHD metric without sacrificing target coverage in all quartiles. Prone positioning was the technique least susceptible to BV effects in meeting the MHD≤1 Gy goal.
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Affiliation(s)
- A Moncion
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - K Griffith
- Department of Biostatistics, University of Michigan, Ann Arbor, MI
| | - E M Walker
- Department of Radiation Oncology, Henry Ford Cancer Institute, Detroit, MI
| | - R Jagsi
- Department of Radiation Oncology, Emory University, Atlanta, GA
| | - M M Dominello
- Department of Radiation Oncology, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI
| | - M Wilson
- MHP Radiation Oncology Institute/GenesisCare, Farmington Hills, MI
| | - M Mietzel
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - M Grubb
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - R Marsh
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - F A Vicini
- MHP Radiation Oncology Institute/GenesisCare, Farmington Hills, MI
| | - L J Pierce
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Herr DJ, Moncion A, Griffith K, Marsh R, Grubb M, Bhatt AK, Dominello MM, Walker EM, Narayana V, Abu-Isa EI, Vicini FA, Hayman JA, Pierce LJ. Factors Associated with Cardiac Radiation Dose Reduction Following Hypofractionated Radiation Therapy for Localized, Left-Sided Breast Cancer in a Large Statewide Quality Consortium. Int J Radiat Oncol Biol Phys 2023; 117:S138. [PMID: 37784352 DOI: 10.1016/j.ijrobp.2023.06.544] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/04/2023]
Abstract
PURPOSE/OBJECTIVE(S) Limiting radiation dose to the heart is important for minimizing the risk of long-term cardiac toxicity in patients with left-sided early-stage breast cancer. MATERIALS/METHODS Prospectively collected dosimetric data were analyzed for patients undergoing hypofractionated radiation therapy to the left breast for localized node-negative breast cancer within the Michigan Radiation Oncology Quality Consortium (MROQC) from 2016-2022. Goals for limiting cardiac dose were adjusted over time. From 2016-2020, the cardiac quality metric focused on total mean heart dose (MHD) from the composite whole breast and boost plans, tightening from a goal of MHD ≤2 Gy to MHD ≤1.2 Gy by 2020. In 2021-2022, the cardiac metric transitioned to a combined goal of MHD ≤1.0 Gy from the whole breast plan and ≥95% lumpectomy cavity planning target volume (PTV) receiving 95% of the prescription dose. Separate multivariate logistic regression models were developed to assess for covariates associated with meeting the MHD goal in 2016-2020 and combined MHD/PTV coverage goal in 2021-2022. RESULTS In total, 4,165 patients were analyzed with a median age of 64 years. Most patients (86%) had either Tis or T1 disease, and 66% received hormone therapy. Baseline demographic and disease characteristics did not change substantially between treatment periods. Use of breath-hold or motion gating increased from 42% in 2016-2020 to 46% in 2021-2022. Similarly, use of prone positioning increased from 12% to 20%. From 2016-2020, 90.9% of plans achieved the MHD goal, compared to 93.6% of plans achieving the composite MHD/PTV goal from 2021-2022. On multivariate analysis in the 2016-2020 cohort, treatment with motion management (OR 5.20, 95% CI [3.59-7.54], p<0.0001) or prone positioning (OR 3.21, 95% CI [1.85-5.57], p < 0.0001) were associated with meeting the MHD goal, while receipt of boost (OR 0.25, 95% CI [0.17-0.39], p<0.0001) and omission of hormone therapy (OR 0.65, 95% CI [0.49-0.88], p = 0.0047), were associated with not meeting the MHD goal. During the era including composite heart dose and PTV coverage goals (2021-2022), treatment with motion management (OR 1.89, 95% CI [1.12-3.21], p = 0.018) or prone positioning (OR 3.71, 95% CI [1.73-7.95], p = 0.0008) were associated with meeting the combined goal, while larger breast volume (≥1440 cc, OR 0.34, 95% CI [0.13 - 0.91], p = 0.031) and treatment at an academic center (OR 0.36, 95% CI [0.22-0.67], p = 0.0009) were associated with not meeting the combined goal. CONCLUSION In our statewide consortium, rates of compliance with aggressive targets for limiting cardiac dose remain high, despite tightening of these goals to include lower mean heart doses and inclusion of a concurrent PTV coverage goal. Treatment using motion management or prone positioning is associated with achieving the cardiac dose goals.
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Affiliation(s)
- D J Herr
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - A Moncion
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - K Griffith
- Department of Biostatistics, University of Michigan, Ann Arbor, MI
| | - R Marsh
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - M Grubb
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - A K Bhatt
- Karmanos Cancer Institute at McLaren Greater Lansing, Lansing, MI
| | - M M Dominello
- Department of Radiation Oncology, Barbara Ann Karmanos Cancer Institute, Wayne State University School of Medicine, Detroit, MI
| | - E M Walker
- Department of Radiation Oncology, Henry Ford Cancer Institute, Detroit, MI
| | - V Narayana
- Ascension Providence Hospital, Southfield, MI
| | - E I Abu-Isa
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI; Ascension Providence Hospital, Southfield, MI
| | - F A Vicini
- MHP Radiation Oncology Institute/GenesisCare, Farmington Hills, MI
| | - J A Hayman
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
| | - L J Pierce
- Department of Radiation Oncology, University of Michigan, Ann Arbor, MI
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Tong X, Cha J, Guo M, Liu JH, Reynolds G, Loyd Z, Walker EM, Soleimanpour S, Stein RA, Mchaourab H, Stein R. Determining how MAFA and MAFB transcription factors activity is influenced by structural differences predicted by AlphaFold2. bioRxiv 2023:2023.08.23.554429. [PMID: 37662349 PMCID: PMC10473715 DOI: 10.1101/2023.08.23.554429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
MAFA and MAFB are related basic-leucine-zipper domain containing transcription factors which have important regulatory roles in a variety of cellular contexts, including pancreatic islet hormone producing α and β cells. These proteins have similar as well as distinct functional properties, and here we first used AlphaFold2, an artificial intelligence-based structural prediction program, to obtain insight into the three-dimensional organization of their non-DNA binding/dimerization sequences. This analysis was conducted on the wildtype (WT) proteins as well the pathogenic MAFA Ser64Phe (MAFA S64F ) and MAFB Ser70Ala (MAFB S70A ) mutants, with structural differences revealed between MAFA WT and MAFB WT in addition to MAFA S64F and MAFA WT , but not MAFB S70A and MAFB WT . Functional analysis disclosed that the inability to properly phosphorylate at S70 in MAFB S70A , like S65 in MAFA S64F , greatly increased protein stability and enabled MAFB S70A to accelerate cellular senescence in cultured cells. Significant differences were also observed in the ability of MAFA, MAFA S64F , MAFB, and MAFB S70A to cooperatively stimulate Insulin enhancer-driven activity in the presence of other islet-enriched transcription factors. Experiments performed on protein chimeras disclosed that these properties were greatly influenced by structural differences found between the WT and mutant proteins. In general, these results revealed that AlphaFold2 predicts features essential to protein activity.
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8
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Cha J, Tong X, Walker EM, Dahan T, Cochrane VA, Ashe S, Russell R, Osipovich AB, Mawla AM, Guo M, Liu JH, Loyd ZA, Huising MO, Magnuson MA, Hebrok M, Dor Y, Stein R. Species-specific roles for the MAFA and MAFB transcription factors in regulating islet β cell identity. JCI Insight 2023; 8:e166386. [PMID: 37606041 PMCID: PMC10543725 DOI: 10.1172/jci.insight.166386] [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: 10/19/2022] [Accepted: 07/06/2023] [Indexed: 08/23/2023] Open
Abstract
Type 2 diabetes (T2D) is associated with compromised identity of insulin-producing pancreatic islet β cells, characterized by inappropriate production of other islet cell-enriched hormones. Here, we examined how hormone misexpression was influenced by the MAFA and MAFB transcription factors, closely related proteins that maintain islet cell function. Mice specifically lacking MafA in β cells demonstrated broad, population-wide changes in hormone gene expression with an overall gene signature closely resembling islet gastrin+ (Gast+) cells generated under conditions of chronic hyperglycemia and obesity. A human β cell line deficient in MAFB, but not one lacking MAFA, also produced a GAST+ gene expression pattern. In addition, GAST was detected in human T2D β cells with low levels of MAFB. Moreover, evidence is provided that human MAFB can directly repress GAST gene transcription. These results support a potentially novel, species-specific role for MafA and MAFB in maintaining adult mouse and human β cell identity, respectively. Here, we discuss the possibility that induction of Gast/GAST and other non-β cell hormones, by reduction in the levels of these transcription factors, represents a dysfunctional β cell signature.
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Affiliation(s)
- Jeeyeon Cha
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Xin Tong
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Emily M. Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Tehila Dahan
- Department of Developmental Biology and Cancer Research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Veronica A. Cochrane
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Sudipta Ashe
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Ronan Russell
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Anna B. Osipovich
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Alex M. Mawla
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, California, USA
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Jin-hua Liu
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Zachary A. Loyd
- Division of Diabetes, Endocrinology, and Metabolism, Vanderbilt University Medical Center, Nashville, Tennessee, USA
| | - Mark O. Huising
- Department of Neurobiology, Physiology & Behavior, College of Biological Sciences, University of California, Davis, Davis, California, USA
| | - Mark A. Magnuson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California, San Francisco, San Francisco, California, USA
| | - Yuval Dor
- Department of Developmental Biology and Cancer Research, The Hebrew University-Hadassah Medical School, Jerusalem, Israel
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee, USA
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9
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Sidarala V, Zhu J, Levi-D'Ancona E, Pearson GL, Reck EC, Walker EM, Kaufman BA, Soleimanpour SA. Mitofusin 1 and 2 regulation of mitochondrial DNA content is a critical determinant of glucose homeostasis. Nat Commun 2022; 13:2340. [PMID: 35487893 PMCID: PMC9055072 DOI: 10.1038/s41467-022-29945-7] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [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: 03/08/2021] [Accepted: 03/21/2022] [Indexed: 02/01/2023] Open
Abstract
The dynamin-like GTPases Mitofusin 1 and 2 (Mfn1 and Mfn2) are essential for mitochondrial function, which has been principally attributed to their regulation of fission/fusion dynamics. Here, we report that Mfn1 and 2 are critical for glucose-stimulated insulin secretion (GSIS) primarily through control of mitochondrial DNA (mtDNA) content. Whereas Mfn1 and Mfn2 individually were dispensable for glucose homeostasis, combined Mfn1/2 deletion in β-cells reduced mtDNA content, impaired mitochondrial morphology and networking, and decreased respiratory function, ultimately resulting in severe glucose intolerance. Importantly, gene dosage studies unexpectedly revealed that Mfn1/2 control of glucose homeostasis was dependent on maintenance of mtDNA content, rather than mitochondrial structure. Mfn1/2 maintain mtDNA content by regulating the expression of the crucial mitochondrial transcription factor Tfam, as Tfam overexpression ameliorated the reduction in mtDNA content and GSIS in Mfn1/2-deficient β-cells. Thus, the primary physiologic role of Mfn1 and 2 in β-cells is coupled to the preservation of mtDNA content rather than mitochondrial architecture, and Mfn1 and 2 may be promising targets to overcome mitochondrial dysfunction and restore glucose control in diabetes.
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Affiliation(s)
- Vaibhav Sidarala
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Jie Zhu
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Elena Levi-D'Ancona
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Gemma L Pearson
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emma C Reck
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Emily M Walker
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States
| | - Brett A Kaufman
- Vascular Medicine Institute, Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15260, United States
| | - Scott A Soleimanpour
- Division of Metabolism, Endocrinology & Diabetes and Department of Internal Medicine, University of Michigan, Ann Arbor, MI, 48105, United States.
- Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI, 48105, United States.
- VA Ann Arbor Healthcare System, Ann Arbor, MI, 48105, United States.
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10
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Dai XQ, Camunas-Soler J, Briant LJB, Dos Santos T, Spigelman AF, Walker EM, Arrojo E Drigo R, Bautista A, Jones RC, Avrahami D, Lyon J, Nie A, Smith N, Zhang Y, Johnson J, Manning Fox JE, Michelakis ED, Light PE, Kaestner KH, Kim SK, Rorsman P, Stein RW, Quake SR, MacDonald PE. Heterogenous impairment of α cell function in type 2 diabetes is linked to cell maturation state. Cell Metab 2022; 34:256-268.e5. [PMID: 35108513 PMCID: PMC8852281 DOI: 10.1016/j.cmet.2021.12.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [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: 04/09/2021] [Revised: 10/08/2021] [Accepted: 12/22/2021] [Indexed: 02/03/2023]
Abstract
In diabetes, glucagon secretion from pancreatic α cells is dysregulated. The underlying mechanisms, and whether dysfunction occurs uniformly among cells, remain unclear. We examined α cells from human donors and mice using electrophysiological, transcriptomic, and computational approaches. Rising glucose suppresses α cell exocytosis by reducing P/Q-type Ca2+ channel activity, and this is disrupted in type 2 diabetes (T2D). Upon high-fat feeding of mice, α cells shift toward a "β cell-like" electrophysiological profile in concert with indications of impaired identity. In human α cells we identified links between cell membrane properties and cell surface signaling receptors, mitochondrial respiratory chain complex assembly, and cell maturation. Cell-type classification using machine learning of electrophysiology data demonstrated a heterogenous loss of "electrophysiologic identity" in α cells from donors with type 2 diabetes. Indeed, a subset of α cells with impaired exocytosis is defined by an enrichment in progenitor and lineage markers and upregulation of an immature transcriptomic phenotype, suggesting important links between α cell maturation state and dysfunction.
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Affiliation(s)
- Xiao-Qing Dai
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Joan Camunas-Soler
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94518, USA
| | - Linford J B Briant
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Churchill Hospital, Oxford OX3 7LE, UK
| | - Theodore Dos Santos
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Aliya F Spigelman
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Emily M Walker
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48105, USA
| | - Rafael Arrojo E Drigo
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Austin Bautista
- Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Robert C Jones
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Dana Avrahami
- Endocrinology and Metabolism Department, Hadassah-Hebrew University Medical Centre, Jerusalem, Israel
| | - James Lyon
- Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Aifang Nie
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Nancy Smith
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Yongneng Zhang
- Department of Medicine, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Janyne Johnson
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Jocelyn E Manning Fox
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | | | - Peter E Light
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA; Stanford Diabetes Research Center, Stanford University, Stanford, CA 94305, USA
| | - Patrik Rorsman
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, Churchill Hospital, Oxford OX3 7LE, UK
| | - Roland W Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Stephen R Quake
- Department of Bioengineering, Stanford University, Stanford, CA 94305, USA; Chan Zuckerberg Biohub, San Francisco, CA 94518, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Patrick E MacDonald
- Department of Pharmacology, University of Alberta, Edmonton, AB T6G2R3, Canada; Alberta Diabetes Institute, University of Alberta, Edmonton, AB T6G2R3, Canada.
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11
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Walker EM, Cha J, Tong X, Guo M, Liu JH, Yu S, Iacovazzo D, Mauvais-Jarvis F, Flanagan SE, Korbonits M, Stafford J, Jacobson DA, Stein R. Sex-biased islet β cell dysfunction is caused by the MODY MAFA S64F variant by inducing premature aging and senescence in males. Cell Rep 2021; 37:109813. [PMID: 34644565 PMCID: PMC8845126 DOI: 10.1016/j.celrep.2021.109813] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [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: 03/04/2021] [Revised: 07/21/2021] [Accepted: 09/17/2021] [Indexed: 12/11/2022] Open
Abstract
A heterozygous missense mutation of the islet β cell-enriched MAFA transcription factor (p.Ser64Phe [S64F]) is found in patients with adult-onset β cell dysfunction (diabetes or insulinomatosis), with men more prone to diabetes than women. This mutation engenders increased stability to the unstable MAFA protein. Here, we develop a S64F MafA mouse model to determine how β cell function is affected and find sex-dependent phenotypes. Heterozygous mutant males (MafAS64F/+) display impaired glucose tolerance, while females are slightly hypoglycemic with improved blood glucose clearance. Only MafAS64F/+ males show transiently higher MafA protein levels preceding glucose intolerance and sex-dependent changes to genes involved in Ca2+ signaling, DNA damage, aging, and senescence. MAFAS64F production in male human β cells also accelerate cellular senescence and increase senescence-associated secretory proteins compared to cells expressing MAFAWT. These results implicate a conserved mechanism of accelerated islet aging and senescence in promoting diabetes in MAFAS64F carriers in a sex-biased manner.
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Affiliation(s)
- Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Jeeyeon Cha
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Xin Tong
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Min Guo
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Jin-Hua Liu
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Sophia Yu
- Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Donato Iacovazzo
- Centre for Endocrinology, Barts and The London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - Franck Mauvais-Jarvis
- Section of Endocrinology and Metabolism, Department of Medicine, Tulane University Health Sciences Center, New Orleans, LA, USA; Southeast Louisiana Veterans Healthcare System, New Orleans, LA, USA; Tulane Center of Excellence in Sex-Based Biology & Medicine, Tulane University Health Sciences Center, New Orleans, LA, USA
| | - Sarah E Flanagan
- Institute of Biomedical and Clinical Science, University of Exeter Medical School, Exeter EX2 5DW, UK
| | - Márta Korbonits
- Centre for Endocrinology, Barts and The London School of Medicine, Queen Mary University of London, London EC1M 6BQ, UK
| | - John Stafford
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA; Division of Diabetes, Endocrinology, and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA; Tennessee Valley Healthcare System, Veterans Affairs, Nashville, TN, USA
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, USA.
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Abstract
Both type 1 and type 2 diabetes mellitus are advancing at exponential rates, placing significant burdens on health care networks worldwide. Although traditional pharmacologic therapies such as insulin and oral antidiabetic stalwarts like metformin and the sulfonylureas continue to be used, newer drugs are now on the market targeting novel blood glucose-lowering pathways. Furthermore, exciting new developments in the understanding of beta cell and islet biology are driving the potential for treatments targeting incretin action, islet transplantation with new methods for immunologic protection, and the generation of functional beta cells from stem cells. Here we discuss the mechanistic details underlying past, present, and future diabetes therapies and evaluate their potential to treat and possibly reverse type 1 and 2 diabetes in humans. SIGNIFICANCE STATEMENT: Diabetes mellitus has reached epidemic proportions in the developed and developing world alike. As the last several years have seen many new developments in the field, a new and up to date review of these advances and their careful evaluation will help both clinical and research diabetologists to better understand where the field is currently heading.
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Affiliation(s)
- Leslie S Satin
- Department of Pharmacology (L.S.S.), Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine (L.S.S., S.A.S., E.M.W.), and Brehm Diabetes Center (L.S.S., S.A.S., E.M.W.), University of Michigan Medical School, Ann Arbor, Michigan; and VA Ann Arbor Healthcare System, Ann Arbor, Michigan (S.A.S.) ; ;
| | - Scott A Soleimanpour
- Department of Pharmacology (L.S.S.), Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine (L.S.S., S.A.S., E.M.W.), and Brehm Diabetes Center (L.S.S., S.A.S., E.M.W.), University of Michigan Medical School, Ann Arbor, Michigan; and VA Ann Arbor Healthcare System, Ann Arbor, Michigan (S.A.S.)
| | - Emily M Walker
- Department of Pharmacology (L.S.S.), Division of Metabolism, Endocrinology, and Diabetes, Department of Internal Medicine (L.S.S., S.A.S., E.M.W.), and Brehm Diabetes Center (L.S.S., S.A.S., E.M.W.), University of Michigan Medical School, Ann Arbor, Michigan; and VA Ann Arbor Healthcare System, Ann Arbor, Michigan (S.A.S.) ; ;
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13
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Abstract
Insulin-producing pancreatic β-cells are central to glucose homeostasis, and their failure is a principal driver of diabetes development. To preserve optimal health β-cells must withstand both intrinsic and extrinsic stressors, ranging from inflammation to increased peripheral insulin demand, in addition to maintaining insulin biosynthesis and secretory machinery. Autophagy is increasingly being appreciated as a critical β-cell quality control system vital for glycemic control. Here we focus on the underappreciated, yet crucial, roles for selective and organelle-specific forms of autophagy as mediators of β-cell health. We examine the unique molecular players underlying each distinct form of autophagy in β-cells, including selective autophagy of mitochondria, insulin granules, lipid, intracellular amyloid aggregates, endoplasmic reticulum, and peroxisomes. We also describe how defects in selective autophagy pathways contribute to the development of diabetes. As all forms of autophagy are not the same, a refined view of β-cell selective autophagy may inform new approaches to defend against the various insults leading to β-cell failure in diabetes.
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Affiliation(s)
- Gemma L Pearson
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | | | - Emily M Walker
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
| | | | - Scott A Soleimanpour
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI
- Veterans Affairs Ann Arbor Health Care System, Ann Arbor, MI
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14
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Bohin N, Keeley TM, Carulli AJ, Walker EM, Carlson EA, Gao J, Aifantis I, Siebel CW, Rajala MW, Myers MG, Jones JC, Brindley CD, Dempsey PJ, Samuelson LC. Rapid Crypt Cell Remodeling Regenerates the Intestinal Stem Cell Niche after Notch Inhibition. Stem Cell Reports 2020; 15:156-170. [PMID: 32531190 PMCID: PMC7363878 DOI: 10.1016/j.stemcr.2020.05.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 08/04/2019] [Revised: 05/12/2020] [Accepted: 05/13/2020] [Indexed: 12/16/2022] Open
Abstract
Intestinal crypts have great capacity for repair and regeneration after intestinal stem cell (ISC) injury. Here, we define the cellular remodeling process resulting from ISC niche interruption by transient Notch pathway inhibition in adult mice. Although ISCs were retained, lineage tracing demonstrated a marked reduction in ISC function after Notch disruption. Surprisingly, Notch ligand-expressing Paneth cells were rapidly lost by apoptotic cell death. The ISC-Paneth cell changes were followed by a regenerative response, characterized by expansion of cells expressing Notch ligands Dll1 and Dll4, enhanced Notch signaling, and a proliferative surge. Lineage tracing and organoid studies showed that Dll1-expressing cells were activated to function as multipotential progenitors, generating both absorptive and secretory cells and replenishing the vacant Paneth cell pool. Our analysis uncovered a dynamic, multicellular remodeling response to acute Notch inhibition to repair the niche and restore homeostasis. Notably, this crypt regenerative response did not require ISC loss.
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Affiliation(s)
- Natacha Bohin
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Theresa M Keeley
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Alexis J Carulli
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Emily M Walker
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Elizabeth A Carlson
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jie Gao
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Iannis Aifantis
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA
| | - Christian W Siebel
- Department of Discovery Oncology, Genentech, Inc, South San Francisco, CA 94080, USA
| | - Michael W Rajala
- Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Martin G Myers
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jennifer C Jones
- Department of Pediatrics, University of Colorado Medical School, Aurora, CO 80045, USA
| | - Constance D Brindley
- Department of Pediatrics, University of Colorado Medical School, Aurora, CO 80045, USA
| | - Peter J Dempsey
- Department of Pediatrics, University of Colorado Medical School, Aurora, CO 80045, USA
| | - Linda C Samuelson
- Department of Molecular & Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA; Program in Cellular and Molecular Biology, University of Michigan, Ann Arbor, MI 48109, USA; Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
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15
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Russell R, Carnese PP, Hennings TG, Walker EM, Russ HA, Liu JS, Giacometti S, Stein R, Hebrok M. Loss of the transcription factor MAFB limits β-cell derivation from human PSCs. Nat Commun 2020; 11:2742. [PMID: 32488111 PMCID: PMC7265500 DOI: 10.1038/s41467-020-16550-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [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: 07/23/2019] [Accepted: 05/06/2020] [Indexed: 12/11/2022] Open
Abstract
Next generation sequencing studies have highlighted discrepancies in β-cells which exist between mice and men. Numerous reports have identified MAF BZIP Transcription Factor B (MAFB) to be present in human β-cells postnatally, while its expression is restricted to embryonic and neo-natal β-cells in mice. Using CRISPR/Cas9-mediated gene editing, coupled with endocrine cell differentiation strategies, we dissect the contribution of MAFB to β-cell development and function specifically in humans. Here we report that MAFB knockout hPSCs have normal pancreatic differentiation capacity up to the progenitor stage, but favor somatostatin- and pancreatic polypeptide–positive cells at the expense of insulin- and glucagon-producing cells during endocrine cell development. Our results describe a requirement for MAFB late in the human pancreatic developmental program and identify it as a distinguishing transcription factor within islet cell subtype specification. We propose that hPSCs represent a powerful tool to model human pancreatic endocrine development and associated disease pathophysiology. The MAF bZIP transcription factor B (MAFB) is present in postnatal human beta cells but its role is unclear. Here, the authors show that MAFB regulates endocrine pancreatic cell fate specification.
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Affiliation(s)
- Ronan Russell
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Phichitpol P Carnese
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Thomas G Hennings
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Holger A Russ
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA.,Barbara Davis Center for Diabetes, School of Medicine, University of Colorado Denver, Aurora, CO, 80045, USA
| | - Jennifer S Liu
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Simone Giacometti
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN, 37232, USA
| | - Matthias Hebrok
- UCSF Diabetes Center, University of California San Francisco, San Francisco, CA, 94143, USA.
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16
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Cyphert HA, Walker EM, Hang Y, Dhawan S, Haliyur R, Bonatakis L, Avrahami D, Brissova M, Kaestner KH, Bhushan A, Powers AC, Stein R. Examining How the MAFB Transcription Factor Affects Islet β-Cell Function Postnatally. Diabetes 2019; 68:337-348. [PMID: 30425060 PMCID: PMC6341297 DOI: 10.2337/db18-0903] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2018] [Accepted: 10/31/2018] [Indexed: 12/11/2022]
Abstract
The sustained expression of the MAFB transcription factor in human islet β-cells represents a distinct difference in mice. Moreover, mRNA expression of closely related and islet β-cell-enriched MAFA does not peak in humans until after 9 years of age. We show that the MAFA protein also is weakly produced within the juvenile human islet β-cell population and that MafB expression is postnatally restricted in mouse β-cells by de novo DNA methylation. To gain insight into how MAFB affects human β-cells, we developed a mouse model to ectopically express MafB in adult mouse β-cells using MafA transcriptional control sequences. Coexpression of MafB with MafA had no overt impact on mouse β-cells, suggesting that the human adult β-cell MAFA/MAFB heterodimer is functionally equivalent to the mouse MafA homodimer. However, MafB alone was unable to rescue the islet β-cell defects in a mouse mutant lacking MafA in β-cells. Of note, transgenic production of MafB in β-cells elevated tryptophan hydroxylase 1 mRNA production during pregnancy, which drives the serotonin biosynthesis critical for adaptive maternal β-cell responses. Together, these studies provide novel insight into the role of MAFB in human islet β-cells.
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Affiliation(s)
- Holly A Cyphert
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Yan Hang
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, Beckman Research Institute, City of Hope, Duarte, CA
| | - Rachana Haliyur
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Lauren Bonatakis
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Dana Avrahami
- Endocrinology and Metabolism Service, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Marcela Brissova
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Anil Bhushan
- Diabetes Center, University of California, San Francisco, San Francisco, CA
| | - Alvin C Powers
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
- Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN
- Department of Veterans Affairs, Tennessee Valley Healthcare System, Nashville, TN
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
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Huang C, Walker EM, Dadi PK, Hu R, Xu Y, Zhang W, Sanavia T, Mun J, Liu J, Nair GG, Tan HYA, Wang S, Magnuson MA, Stoeckert CJ, Hebrok M, Gannon M, Han W, Stein R, Jacobson DA, Gu G. Synaptotagmin 4 Regulates Pancreatic β Cell Maturation by Modulating the Ca 2+ Sensitivity of Insulin Secretion Vesicles. Dev Cell 2018; 45:347-361.e5. [PMID: 29656931 PMCID: PMC5962294 DOI: 10.1016/j.devcel.2018.03.013] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [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: 09/28/2017] [Revised: 02/12/2018] [Accepted: 03/19/2018] [Indexed: 12/14/2022]
Abstract
Islet β cells from newborn mammals exhibit high basal insulin secretion and poor glucose-stimulated insulin secretion (GSIS). Here we show that β cells of newborns secrete more insulin than adults in response to similar intracellular Ca2+ concentrations, suggesting differences in the Ca2+ sensitivity of insulin secretion. Synaptotagmin 4 (Syt4), a non-Ca2+ binding paralog of the β cell Ca2+ sensor Syt7, increased by ∼8-fold during β cell maturation. Syt4 ablation increased basal insulin secretion and compromised GSIS. Precocious Syt4 expression repressed basal insulin secretion but also impaired islet morphogenesis and GSIS. Syt4 was localized on insulin granules and Syt4 levels inversely related to the number of readily releasable vesicles. Thus, transcriptional regulation of Syt4 affects insulin secretion; Syt4 expression is regulated in part by Myt transcription factors, which repress Syt4 transcription. Finally, human SYT4 regulated GSIS in EndoC-βH1 cells, a human β cell line. These findings reveal the role that altered Ca2+ sensing plays in regulating β cell maturation.
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Affiliation(s)
- Chen Huang
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; The Program of Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Prasanna K Dadi
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Ruiying Hu
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; The Program of Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Yanwen Xu
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; The Program of Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Wenjian Zhang
- China-Japan Friendship Hospital, Beijing 100029, P. R. China
| | - Tiziana Sanavia
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Jisoo Mun
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Jennifer Liu
- Diabetes Center, UCSF, San Francisco, CA 94143, USA
| | | | - Hwee Yim Angeline Tan
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Singapore, Singapore
| | - Sui Wang
- Department of Ophthalmology, Mary M. and Sash A. Spencer Center for Vision Research, Stanford University School of Medicine, Palo Alto, CA 94304, USA
| | - Mark A Magnuson
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Christian J Stoeckert
- Institute for Biomedical Informatics and Department of Genetics, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | | | - Maureen Gannon
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; The Program of Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Department of Medicine, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - Weiping Han
- Laboratory of Metabolic Medicine, Singapore Bioimaging Consortium, Singapore, Singapore
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA
| | - David A Jacobson
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA.
| | - Guoqiang Gu
- Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; Center for Stem Cell Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA; The Program of Developmental Biology, Vanderbilt University School of Medicine, Department of Veterans Affairs, Tennessee Valley Health Authority, Nashville, TN 37232, USA.
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18
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Chin AM, Tsai YH, Finkbeiner SR, Nagy MS, Walker EM, Ethen NJ, Williams BO, Battle MA, Spence JR. A Dynamic WNT/β-CATENIN Signaling Environment Leads to WNT-Independent and WNT-Dependent Proliferation of Embryonic Intestinal Progenitor Cells. Stem Cell Reports 2016; 7:826-839. [PMID: 27720905 PMCID: PMC5106483 DOI: 10.1016/j.stemcr.2016.09.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2014] [Revised: 09/07/2016] [Accepted: 09/08/2016] [Indexed: 02/08/2023] Open
Abstract
Much of our understanding about how intestinal stem and progenitor cells are regulated comes from studying the late fetal stages of development and the adult intestine. In this light, little is known about intestine development prior to the formation of stereotypical villus structures with columnar epithelium, a stage when the epithelium is pseudostratified and appears to be a relatively uniform population of progenitor cells with high proliferative capacity. Here, we investigated a role for WNT/β-CATENIN signaling during the pseudostratified stages of development (E13.5, E14.5) and following villus formation (E15.5) in mice. In contrast to the well-described role for WNT/β-CATENIN signaling as a regulator of stem/progenitor cells in the late fetal and adult gut, conditional epithelial deletion of β-catenin or the Frizzled co-receptors Lrp5 and Lrp6 had no effect on epithelial progenitor cell proliferation in the pseudostratified epithelium. Mutant embryos displayed obvious developmental defects, including loss of proliferation and disruptions in villus formation starting only at E15.5. Mechanistically, our data suggest that WNT signaling-mediated proliferation at the time of villus formation is driven by mesenchymal, but not epithelial, WNT ligand secretion. WNT/β-CATENIN signaling is not required for proliferation during pseudostratified growth Deleting epithelial β-catenin causes loss of proliferation during villus morphogenesis Loss of WNT/β-CATENIN signaling leads to perturbations in villus formation Mesenchymal, not epithelial, WNT ligands are required for epithelial proliferation
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Affiliation(s)
- Alana M Chin
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Yu-Hwai Tsai
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Stacy R Finkbeiner
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Center for Organogenesis, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Melinda S Nagy
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA
| | - Emily M Walker
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Nicole J Ethen
- Program in Skeletal Disease and Tumor Microenvironment, Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Bart O Williams
- Program in Skeletal Disease and Tumor Microenvironment, Center for Cancer and Cell Biology, Van Andel Research Institute, Grand Rapids, MI 49503, USA
| | - Michele A Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Jason R Spence
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI 48109, USA; Center for Organogenesis, University of Michigan Medical School, Ann Arbor, MI 48109, USA.
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19
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Abstract
Diabetes mellitus arises from insufficient insulin secretion from pancreatic islet β-cells. In type 2 diabetes (T2D), β-cell dysfunction is associated with inactivation and/or loss of transcription factor (TF) activity, including Pdx1. Notably, this particular TF is viewed as a master regulator of pancreas development and islet β-cell formation, identity and function. TFs, like Pdx1, recruit coregulators to transduce activating and/or repressing signals to the general transcriptional machinery for controlling gene expression, including modifiers of DNA, histones and nucleosome architecture. These coregulators impart a secondary layer of control that can be exploited to modulate TF activity. In this review, we describe Pdx1-recruited coregulators that impact chromatin structure, consequently influencing normal β-cell function and likely Pdx1 activity in pathophysiological settings.
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Affiliation(s)
- J M Spaeth
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - E M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - R Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee.
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20
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Banerjee RR, Cyphert HA, Walker EM, Chakravarthy H, Peiris H, Gu X, Liu Y, Conrad E, Goodrich L, Stein RW, Kim SK. Gestational Diabetes Mellitus From Inactivation of Prolactin Receptor and MafB in Islet β-Cells. Diabetes 2016; 65:2331-41. [PMID: 27217483 PMCID: PMC4955982 DOI: 10.2337/db15-1527] [Citation(s) in RCA: 90] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 05/11/2016] [Indexed: 12/21/2022]
Abstract
β-Cell proliferation and expansion during pregnancy are crucial for maintaining euglycemia in response to increased metabolic demands placed on the mother. Prolactin and placental lactogen signal through the prolactin receptor (PRLR) and contribute to adaptive β-cell responses in pregnancy; however, the in vivo requirement for PRLR signaling specifically in maternal β-cell adaptations remains unknown. We generated a floxed allele of Prlr, allowing conditional loss of PRLR in β-cells. In this study, we show that loss of PRLR signaling in β-cells results in gestational diabetes mellitus (GDM), reduced β-cell proliferation, and failure to expand β-cell mass during pregnancy. Targeted PRLR loss in maternal β-cells in vivo impaired expression of the transcription factor Foxm1, both G1/S and G2/M cyclins, tryptophan hydroxylase 1 (Tph1), and islet serotonin production, for which synthesis requires Tph1. This conditional system also revealed that PRLR signaling is required for the transient gestational expression of the transcription factor MafB within a subset of β-cells during pregnancy. MafB deletion in maternal β-cells also produced GDM, with inadequate β-cell expansion accompanied by failure to induce PRLR-dependent target genes regulating β-cell proliferation. These results unveil molecular roles for PRLR signaling in orchestrating the physiologic expansion of maternal β-cells during pregnancy.
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Affiliation(s)
- Ronadip R Banerjee
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA Division of Endocrinology, Gerontology and Metabolism, Department of Medicine, Stanford University School of Medicine, Stanford, CA
| | - Holly A Cyphert
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Harini Chakravarthy
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA
| | - Heshan Peiris
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA
| | - Xueying Gu
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA
| | - Yinghua Liu
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA
| | - Elizabeth Conrad
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Lisa Goodrich
- Department of Neurobiology, Harvard Medical School, Boston, MA
| | - Roland W Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, TN
| | - Seung K Kim
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA Division of Oncology, Department of Medicine, Stanford University School of Medicine, Stanford, CA Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
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21
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Paul L, Walker EM, Drosos Y, Cyphert HA, Neale G, Stein R, South J, Grosveld G, Herrera PL, Sosa-Pineda B. Lack of Prox1 Downregulation Disrupts the Expansion and Maturation of Postnatal Murine β-Cells. Diabetes 2016; 65:687-98. [PMID: 26631740 PMCID: PMC4764148 DOI: 10.2337/db15-0713] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 11/20/2015] [Indexed: 12/18/2022]
Abstract
Transcription factor expression fluctuates during β-cell ontogeny, and disruptions in this pattern can affect the development or function of those cells. Here we uncovered that murine endocrine pancreatic progenitors express high levels of the homeodomain transcription factor Prox1, whereas both immature and mature β-cells scarcely express this protein. We also investigated if sustained Prox1 expression is incompatible with β-cell development or maintenance using transgenic mouse approaches. We discovered that Prox1 upregulation in mature β-cells has no functional consequences; in contrast, Prox1 overexpression in immature β-cells promotes acute fasting hyperglycemia. Using a combination of immunostaining and quantitative and comparative gene expression analyses, we determined that Prox1 upregulation reduces proliferation, impairs maturation, and enables apoptosis in postnatal β-cells. Also, we uncovered substantial deficiency in β-cells that overexpress Prox1 of the key regulator of β-cell maturation MafA, several MafA downstream targets required for glucose-stimulated insulin secretion, and genes encoding important components of FGF signaling. Moreover, knocking down PROX1 in human EndoC-βH1 β-cells caused increased expression of many of these same gene products. These and other results in our study indicate that reducing the expression of Prox1 is beneficial for the expansion and maturation of postnatal β-cells.
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Affiliation(s)
- Leena Paul
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN
| | - Emily M Walker
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
| | - Yiannis Drosos
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN
| | - Holly A Cyphert
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
| | - Geoffrey Neale
- Hartwell Center for Bioinformatics & Biotechnology, St. Jude Children's Research Hospital, Memphis, TN
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
| | - Jack South
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN
| | - Gerard Grosveld
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN
| | - Pedro L Herrera
- Department of Genetic Medicine and Development, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Beatriz Sosa-Pineda
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL
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22
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Abstract
BACKGROUND & AIMS The embryonic small intestinal epithelium is highly proliferative, and although much is known about mechanisms regulating proliferation in the adult intestine, the mechanisms controlling epithelial cell proliferation in the developing intestine are less clear. GATA4, a transcription factor that regulates proliferation in other developing tissues, is first expressed early in the developing gut in midgut endoderm. GATA4 function within midgut endoderm and the early intestinal epithelium has not been investigated. METHODS Using Sonic Hedgehog Cre to eliminate GATA4 in the midgut endoderm of mouse embryos, we determined the impact of loss of GATA4 on intestinal development, including epithelial cell proliferation, between E9.5-E18.5. RESULTS We found that intestinal length and width were decreased in GATA4 mutants compared with controls. GATA4-deficient intestinal epithelium contained fewer cells, and epithelial girth was decreased. We further observed a decreased proportion of proliferating cells at E10.5 and E11.5 in GATA4 mutants. We demonstrated that GATA4 binds to chromatin containing GATA4 consensus binding sites within Cyclin D2 (Ccnd2), Cyclin dependent kinase 6 (Cdk6), and Frizzled 5 (Fzd5). Moreover, Ccnd2, Cdk6, and Fzd5 transcripts were reduced at E11.5 in GATA4 mutant tissue. Villus morphogenesis was delayed, and villus structure was abnormal in GATA4 mutant intestine. CONCLUSIONS Our data identify GATA4 as an essential regulator of early intestinal epithelial cell proliferation. We propose that GATA4 controls proliferation in part by directly regulating transcription of cell cycle mediators. Our data further suggest that GATA4 affects proliferation through transcriptional regulation of Fzd5, perhaps by influencing the response of the epithelium to WNT signaling.
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Affiliation(s)
| | | | | | - Michele A. Battle
- Correspondence Address correspondence to: Michele A. Battle, PhD, Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin 53226. fax: (414) 955-6517.Department of Cell BiologyNeurobiology and AnatomyMedical College of Wisconsin8701 Watertown Plank RoadMilwaukeeWisconsin 53226
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Walker EM, Thompson CA, Kohlnhofer BM, Faber ML, Battle MA. Characterization of the developing small intestine in the absence of either GATA4 or GATA6. BMC Res Notes 2014; 7:902. [PMID: 25495347 PMCID: PMC4307969 DOI: 10.1186/1756-0500-7-902] [Citation(s) in RCA: 18] [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: 08/18/2014] [Accepted: 11/28/2014] [Indexed: 11/10/2022] Open
Abstract
Background Studies of adult mice lacking either GATA4 or GATA6 in the small intestine demonstrate roles for these factors in small intestinal biology. Deletion of Gata4 in the adult mouse intestine revealed an essential role for GATA4 in jejunal function. Deletion of Gata6 in the adult mouse ileum alters epithelial cell types and ileal enterocyte gene expression. The effect of deletion of Gata4 or Gata6 alone during embryonic small intestinal development, however, has not been examined. We recently demonstrated that loss of both factors in double conditional knockout embryos causes severe defects in jejunal development. Therefore, the goal of this study is to provide phenotypic analysis of the small intestine of single Gata4 and Gata6 conditional knockout embryos. Results Villin-Cre was used to delete Gata4 or Gata6 in the developing intestinal epithelium. Elimination of either GATA4 or GATA6 in the jejunum, where these factors are co-expressed, caused changes in enterocyte and enteroendocrine cell gene expression. Ectopic expression of markers of the ileal-specific bile acid metabolism pathway was induced in GATA4-deficient jejunum but not in GATA6-deficient jejunum. A subtle increase in goblet cells was also identified in jejunum of both mutants. In GATA6-deficient embryonic ileum, villus length was altered, and enterocyte gene expression was perturbed including ectopic expression of the colon marker Car1. Goblet cells were increased, and enteroendocrine cells were decreased. Conclusions Overall, we show that aspects of the phenotypes observed in the small intestine of adult Gata4 and Gata6 conditional knockout mice emerge during development. The effect of eliminating GATA6 from the developing ileum was greater than that of eliminating either GATA4 or GATA6 from the developing jejunum likely reflecting functional redundancy between these factors in the jejunum. Although GATA4 and GATA6 functions overlap, our data also suggest unique functions for GATA4 and GATA6 within the developing intestine. GATA4 likely operates independently of GATA6 within the jejunum to regulate jejunal versus ileal enterocyte identity and consequently jejunal physiology. GATA6 likely regulates enteroendocrine cell differentiation cell autonomously whereas GATA4 affects this population indirectly. Electronic supplementary material The online version of this article (doi:10.1186/1756-0500-7-902) contains supplementary material, which is available to authorized users.
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Affiliation(s)
| | | | | | | | - Michele A Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI 53226, USA.
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24
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Walker EM, Thompson CA, Battle MA. GATA4 and GATA6 regulate intestinal epithelial cytodifferentiation during development. Dev Biol 2014; 392:283-94. [PMID: 24929016 DOI: 10.1016/j.ydbio.2014.05.017] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [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: 12/09/2013] [Revised: 04/06/2014] [Accepted: 05/21/2014] [Indexed: 11/18/2022]
Abstract
The intestinal epithelium performs vital roles in organ function by absorbing nutrients and providing a protective barrier. The zinc-finger containing transcription factors GATA4 and GATA6 regulate enterocyte gene expression and control regional epithelial cell identity in the adult intestinal epithelium. Although GATA4 and GATA6 are expressed in the developing intestine, loss of either factor alone during the period of epithelial morphogenesis and cytodifferentiation fails to disrupt these processes. Therefore, we tested the hypothesis that GATA4 and GATA6 function redundantly to control these aspects of intestinal development. We used Villin-Cre, which deletes specifically in the intestinal epithelium during the period of villus development and epithelial cytodifferentiation, to generate Gata4Gata6 double conditional knockout embryos. Mice lacking GATA4 and GATA6 in the intestinal epithelium died within 24h of birth. At E18.5, intestinal villus architecture and epithelial cell populations were altered. Enterocytes were lost, and goblet cells were increased. Proliferation was also increased in GATA4-GATA6 deficient intestinal epithelium. Although villus morphology appeared normal at E16.5, the first time at which both Gata4 and Gata6 were efficiently reduced, changes in expression of markers of enterocytes, goblet cells, and proliferative cells were detected. Moreover, goblet cell number was increased at E16.5. Expression of the Notch ligand Dll1 and the Notch target Olfm4 were reduced in mutant tissue indicating decreased Notch signaling. Finally, we found that GATA4 occupies chromatin near the Dll1 transcription start site suggesting direct regulation of Dll1 by GATA4. We demonstrate that GATA4 and GATA6 play an essential role in maintaining proper intestinal epithelial structure and in regulating intestinal epithelial cytodifferentiation. Our data highlight a novel role for GATA factors in fine tuning Notch signaling during intestinal epithelial development to repress goblet cell differentiation.
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Affiliation(s)
- Emily M Walker
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA
| | - Cayla A Thompson
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA
| | - Michele A Battle
- Department of Cell Biology, Neurobiology and Anatomy, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, WI, USA.
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25
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Macaskill EJ, Thrush S, Walker EM, Dixon JM. Surgeons’ views on multi-disciplinary breast meetings. Eur J Cancer 2006; 42:905-8. [PMID: 16516461 DOI: 10.1016/j.ejca.2005.12.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2005] [Revised: 11/02/2005] [Accepted: 12/08/2005] [Indexed: 11/30/2022]
Abstract
The aim of this study was to assess surgeons' views and their current commitments to multi-disciplinary breast meetings (MDMs). Two hundred and fifty questionnaires were sent out to registered members of the British Association of Surgical Oncology. Hundred and fifty-three were returned (reply rate 61.2%), of which 136 were suitable for analysis. All those who replied were involved in MDMs. 80.9% held MDMs once a week. Only 28% of MDMs were held during a protected session. Over 95% of surgeons and breast care nurses were present for the whole meeting. Radiologists and pathologists were present for the whole meeting in 90-95% of cases. In contrast, clinical oncologists were present for the whole MDM in 70% of cases and medical oncologists attended the whole meeting in only 44.1% of cases. There was variability in which patients were discussed in MDMs, and in many centres not all patients with cancer were discussed before surgery. Suggestions for improvement of MDMs included more time on protected sessions (72.8% in favour), time to prepare for meetings (29% in favour), allocation of a designated co-ordinator (30.9% in favour) and attendance of oncologists for the whole meeting (over 35% in favour). The majority of Breast MDMs were held at breakfast, lunch or the evening. There was variable attendance with a significant percentage of both clinical and medical oncologists not being present for the whole meeting. A quarter of units did not discuss patients with breast cancer before operation. This study shows that there is a need to improve provision for MDMs and to produce guidelines for these meetings.
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Affiliation(s)
- E J Macaskill
- Academic Office, Edinburgh Breast Unit, Western General Hospital, Edinburgh EH4 2XU, Scotland, UK
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Rice KM, Preston DL, Walker EM, Blough ER. Aging influences multiple incidices of oxidative stress in the aortic media of the Fischer 344/NNiaxBrown Norway/BiNia rat. Free Radic Res 2006; 40:185-97. [PMID: 16390828 DOI: 10.1080/10715760500464957] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [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: 02/07/2023]
Abstract
Here, we determine the influence of aging on multiple markers of oxidative stress in the aorta of adult (6-month), aged (30-month) and very aged (36-month) Fischer 344/NNiaHSdxBrown Norway/BiNia (F344/NxBN) rats. Compared to adults, increases in as determined by oxidation of hydroethidine (HE) to ethidium (Et) were increased 79.7+/-7.0% in 36-month aortae and this finding was highly correlated with increases in medal thickness (r=0.773, p<0.01) and total protein nitration (r=0.706, p<0.01) but not Ki67, a marker for cell proliferation. Regression analysis showed that increases in aortic superoxide anion (O.-2) with aging were significantly correlated with changes in the expression and/or regulation of proteins involved in metabolic (AMPK-alpha), signaling (mitogen activated protein kinases (MAPKs) along with c-Src), apoptotic (Bax, Bcl-2, Traf-2) and transcriptional (NF-kappaB) activities. These results suggest that the aging F344/NxBN aorta may be highly suited for unraveling the molecular events that lead to age-associated alterations in aortic oxidative stress.
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Affiliation(s)
- K M Rice
- Marshall University, Department of Biological Sciences, Huntington, WV 2755-1090, USA
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Walker EM, Stephenson R. Analgesic Effects of Interferential Therapy Current on Cold-Pressor Pain in Healthy Subjects. Physiotherapy 2001. [DOI: 10.1016/s0031-9406(05)61130-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
Stimulation of histamine H(1) receptors produced a marked activation of inositol phospholipid hydrolysis, intracellular calcium mobilization, and stimulation of the c-fos promoter in CHO-H1 cells expressing the H(1) receptor at a level of 3 pmol/mg protein. The latter response was determined using a luciferase-based reporter gene (pGL3). This response to histamine was not sensitive to inhibition by pertussis toxin but could be completely attenuated by the protein kinase C (PKC) inhibitor Ro-31-8220, or by 24-h pretreatment with the phorbol esters phorbol 12,13-dibutyrate or phorbol-12-myristate-13-acetate. Several isoforms of PKC can be detected in CHO-H1 cells (alpha, delta, epsilon, mu, iota, zeta) but only PKCalpha and PKCdelta were down-regulated by prolonged treatment with phorbol esters. Of the two isoforms that were down-regulated, only protein kinase Calpha was translocated to CHO-H1 cell membranes after stimulation with either histamine or phorbol esters. The PKC inhibitor Gö 6976, which inhibits PKCalpha but not PKCdelta, was also able to significantly attenuate the c-fos-luciferase response to histamine. The mitogen-activated protein kinase kinase inhibitor PD 98059 markedly inhibited the response to histamine, suggesting that the likely major target for PKCalpha was the mitogen-activated protein kinase pathway. These data suggest that the histamine H(1) receptor can signal to the nucleus via PKCalpha after activation of phospholipase Cbeta.
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Affiliation(s)
- A C Megson
- Institute of Cell Signalling and School of Biomedical Sciences, Medical School, Queen's Medical Centre, Nottingham, United Kingdom
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Walker EM, Walker SM. Effects of iron overload on the immune system. Ann Clin Lab Sci 2000; 30:354-65. [PMID: 11045759] [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: 02/18/2023]
Abstract
Iron and its binding proteins have immunoregulatory properties, and shifting of immunoregulatory balances by iron excess or deficiency may produce severe, deleterious physiological effects. Effects of iron overload include decreased antibody-mediated and mitogen-stimulated phagocytosis by monocytes and macrophages, alterations in T-lymphocyte subsets, and modification of lymphocyte distribution in different compartments of the immune system. The importance of iron in regulating the expression of T-lymphocyte cell surface markers, influencing the expansion of different T-cell subsets, and affecting immune cell functions can be demonstrated in vitro and in vivo. The poor ability of lymphocytes to sequester excess iron in ferritin may help to explain the immune system abnormalities in iron-overloaded patients. Iron overload as seen in hereditary hemochromatosis patients enhances suppressor T-cell (CD8) numbers and activity, decreases the proliferative capacity, numbers, and activity of helper T cells (CD4) with increases in CD8/CD4 ratios, impairs the generation of cytotoxic T cells, and alters immunoglobulin secretion when compared to treated hereditary hemochromatosis patients or controls. A correlation has recently been found between low CD8+ lymphocyte numbers, liver damage associated with HCV positivity, and severity of iron overload in beta-thalassemia major patients. Iron overload, with its associated increases of serum iron levels and transferrin saturation, may cause a poor response to interferon therapy. Iron overload with hyperferremia is associated with suppressed functions of the complement system (classic or alternative types). High plasma ferritin content in patients with chronic, diffuse diseases of the liver (cirrhosis, chronic hepatitis), beta-thalassemia major, dyserythropoiesis, and hereditary hemochromatosis may induce the development of anti-ferritin antibodies with the production of circulating immune complexes. Increased body stores of iron in various clinical situations may tip the immunoregulatory balance unfavorably to allow increased growth rates of cancer cells and infectious organisms, and complicate the clinical management of preexisting acute and chronic diseases.
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Affiliation(s)
- E M Walker
- Department of Pathology, Marshall University and Huntington DVA Medical Center, West Virginia, 25704, USA.
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Walker EM, Walker SM. Evolution of chemotherapy with platinum compounds. Ann Clin Lab Sci 1999; 29:263-74. [PMID: 10528825] [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: 02/14/2023]
Abstract
Cancer is a major disease entity and cause of death in the human population. The discovery of cisplatin has revolutionized the chemotherapy of human cancer. The full therapeutic potential of cisplatin has not been realized due to the serious side effects and emergence of cisplatin-resistant tumor cells associated with its usage. Protective methods such as extensive hydration, improved schedules of administration, alternate routes of administration, and use of protective agents against specific side effects have allowed the use of higher doses of cisplatin against cisplatin-resistant tumors and has extended the list of tumor systems responsive to cisplatin chemotherapy. Incorporation of cisplatin into a number of cisplatin-based anti-cancer drug combinations has enhanced its effectiveness and allowed the use of lower doses of cisplatin, thus reducing its toxic side effects. Finally, the availability of cisplatin analogues, such as carboplatin and others with reduced toxicity, but increased effectiveness against cisplatin-resistant tumors, has expanded the potential scope and therapeutic promise of the platinum anti-cancer agents. The evolution of chemotherapy with the platinum antitumor compounds is ongoing.
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Affiliation(s)
- E M Walker
- Department of Pathology, Marshall University School of Medicine, Huntington, WV 25704, USA
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Walker EM, Bispham JR, Hill SJ. Nonselective effects of the putative phospholipase C inhibitor, U73122, on adenosine A1 receptor-mediated signal transduction events in Chinese hamster ovary cells. Biochem Pharmacol 1998; 56:1455-62. [PMID: 9827577 DOI: 10.1016/s0006-2952(98)00256-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [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: 02/05/2023]
Abstract
Adenosine A1 receptors can signal, through Gi/o proteins, to inhibit adenylyl cyclase activity and also to stimulate phosphoinositide hydrolysis and the subsequent release of intracellular Ca2+ stores. The aminosteroid U73122 (1-[6-1[17beta-3-methoxyestra-1,3,5(10)-trien-17-yl]amino]hexyl]-1 H-pyrrole-2,5-dione) has been widely used as an inhibitor of phospholipase C, the enzyme mediating phosphoinositide hydrolysis. Using U73122, we sought to selectively block signalling through the phospholipase C pathway, in Chinese hamster ovary (CHO-K1) cells heterologously expressing human adenosine A1 receptors. U73122 inhibited A1 receptor-mediated phosphoinositide hydrolysis, as measured by total inositol phosphate accumulation, over the concentration range 1-15 microM. However, over the same concentration range, it also appeared to inhibit A1 receptor-mediated inhibition of forskolin-stimulated cyclic AMP accumulation, A1 receptor agonist-promoted [35S]GTP-gammaS binding, and at the higher concentrations (10-15 microM) produced marked morphological changes, leading to cytolysis. The structural analogue of U73122, U73343 (1-[6-[[17beta-3-methoxyestra-1,3,5(10-trien-17-yl]amino]hexyl]-2, 5-pyrrolidone-dione), typically used as an inactive control compound, had little effect on these events. The data suggest that U73122 is not a selective inhibitor of phospholipase C activity, interfering with adenosine A1 receptor signalling generally, either at the pre-effector level involving Gi/o proteins, or as a consequence of the morphological changes it induces.
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Affiliation(s)
- E M Walker
- Institute of Cell Signalling, School of Biomedical Sciences, Queen's Medical Centre, Nottingham, UK
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Walker EM, Wolfe MD, Norton ML, Walker SM, Jones MM. Hereditary hemochromatosis. Ann Clin Lab Sci 1998; 28:300-12. [PMID: 9784832] [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: 02/09/2023]
Abstract
Genetic (hereditary) hemochromatosis is probably the most common autosomal recessive disorder found in white Americans, of whom about 5/1,000 (0.5 percent) are homozygous for the associated gene. The hemochromatosis gene is probably located close to the HLA-A locus on the short arm of chromosome 6. Homozygous individuals may develop severe and potentially lethal hemochromatosis, especially after age 39. Hereditary hemochromatosis involves an increased rate of iron absorption from the gut with subsequent progressive storage of iron in soft organs of the body. Excess iron storage eventually produces pituitary, pancreatic, cardiac, and liver dysfunction and death may result from cardiac arrhythmias, congestive heart failure, and/or hepatic failure or cancer. Early diagnosis can prevent these excess iron-induced problems. Iron overload owing to HLA-linked hereditary hemochromatosis can be distinguished from other causes of hemochromatosis by liver biopsies and interpretations. Patients at risk for genetic hemochromatosis should be screened, identified, and treated as early as age 20 to prevent or minimize the deadly complications of hemochromatosis. Population screening should include measurements of serum iron concentration, total iron binding capacity (TIBC), percent saturation of transferrin, and serum ferritin concentrations. Family members of hereditary hemochromatosis patients are at increased risk and should be tested. Screening, identification and early treatment (phlebotomies, sometimes in combination with the use of Desferal or other iron-chelating agents) may help prevent or reduce iron-related organ damage and premature deaths. Early diagnosis and treatment will reduce the population of aging individuals with severe, complicated hemochromatosis and dramatically reduce medical costs (billions of U.S. dollars per annum) associated with the management of this disease.
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Affiliation(s)
- E M Walker
- Department of Pathology, Huntington DVA Medical Center, WV, USA
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Shah DT, Walker EM, Jones MM, Singh PK, Larsen B. Inhibitory effects of seven organosulphur compounds on clinical isolates of Candida species in vitro. Ann Clin Lab Sci 1997; 27:282-6. [PMID: 9210973] [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: 02/04/2023]
Abstract
Thirty clinical isolates of Candida albicans and 10 other Candida species were tested for susceptibility to 6 substituted dithiocarbamates and one dimercaptosuccinate. Dimethyldithiocarbamate, sodium pyrrolidine dithiocarbamate, and sodium diethyldithiocarbamate showed dose-dependent antifungal activity which was partially reversed by the addition of zinc, copper, or iron sulfate with greatest reversal at 2:1 metal to dithiocarbamate molar ratio. Anaerobiosis also interfered with dithiocarbamate antifungal activity.
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Affiliation(s)
- D T Shah
- Department of Pathology, Marshall University School of Medicine, Huntington, WV 25705, USA
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Abstract
The relative abilities of a series of acyclic polyamine chelating agents containing only nitrogen donors (N-donors) to induce the urinary excretion of cadmium has been examined in the rat. The compounds examined include triethylenetetramine dihydrochloride (TRIEN), tris(2-aminoethyl)amine trihydrochloride (TREN), tetraethylenepentamine pentahydrochloride (TETRAEN), and pentaethylenehexamine hexahydrochloride (PENTAEN). Sodium N-methyl-D-glucamine-N-carbodithioate (NaG) was used as a positive control compound. The polyamines induced a significant increase in the urinary excretion of cadmium in rats that had been loaded with cadmium at least 4 d prior to the polyamine treatments. A comparison of these with similar data on macrocylic nitrogen donor systems, which form much more stable complexes with cadmium but are also ineffective in enhancing the excretion of cadmium from such aged deposits, suggests that the factors responsible for the relative inefficiency of these compounds may involve either a difficulty in penetrating cellular membranes or a slow rate of reaction with biologically bound cadmium. The occurrence of oliguria and anuria following the administration of the several of the polyamines indicates that their use is accompanied by significant renal damage in cadmium-exposed rats.
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Affiliation(s)
- M M Jones
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235, USA.
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Joy JE, Walker EM, Koh SG, Bentley JM, Crank AG. Intrahepatic larval nematode infection in the northern spring peeper, Pseudacris crucifer crucifer (Anura: Hylidae), in West Virginia. J Wildl Dis 1996; 32:340-3. [PMID: 8722275 DOI: 10.7589/0090-3558-32.2.340] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 02/01/2023]
Abstract
Larval stages of an unknown nematode were observed encapsulated in the livers of spring peepers, Pseudacris crucifer crucifer (Weid-Neuweid), collected from a marsh in western West Virginia (USA) during the spring breeding seasons of 1993 and 1994. Prevalence and mean intensity of infection were 37% (30 of 82 animals) and 2.03 parasites per infected host, respectively. Capsules with white or darkly pigmented walls were observed in infected livers; the former containing viable larvae, and the latter enveloping larvae in various stages of degeneration.
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Affiliation(s)
- J E Joy
- Department of Biological Sciences, Marshall University, Huntington, West Virginia 25755, USA
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Eberhard ML, Walker EM, Addiss DG, Lammie PJ. A survey of knowledge, attitudes, and perceptions (KAPs) of lymphatic filariasis, elephantiasis, and hydrocele among residents in an endemic area in Haiti. Am J Trop Med Hyg 1996; 54:299-303. [PMID: 8600770 DOI: 10.4269/ajtmh.1996.54.299] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [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: 01/31/2023] Open
Abstract
To assess knowledge, attitudes, and perceptions about bancroftian filariasis, 104 residents of an endemic area in Haiti were interviewed. Questions focused on 1) whether people understood the relationship between infection and disease, 2) recognition of the role that mosquitoes play in transmission, 3) perceived importance of hydrocele and elephantiasis in relation to other recognized diseases, and 4) the willingness of the community to participate in a control program. Fewer than 50% of residents had heard of filariasis and only 6% of those surveyed knew that it was transmitted by mosquitoes. In contrast, all persons knew of the clinical conditions of hydrocele and elephantiasis. Hydrocele was thought to be caused by trauma (60%) or trapped gas (30%); elephantiasis by walking bare foot on soil or water (37%) or by use of ceremonial powder that had been sprinkled on the ground (23%). Of 76 respondents, 53% and 38% thought that hydrocele could be treated through surgery or a drug, respectively, whereas 86 respondents, 85% and 15% believed that either surgery or a drug could be used to treat elephantiasis. In this context, persons were not referring to a specific drug; rather, they believed a drug existed (possibly in some other country) that could cure these conditions. Hydrocele and elephantiasis ranked second to acquired immunodeficiency syndrome as perceived health problems, most likely because residents believed treatment for conditions such as malaria, intestinal worms, anemia, and diarrhea was easily obtained. Responses were influenced by age, sex, and symptoms, but none of these effects were statistically significant except that persons with hydrocele or elephantiasis were more likely to have sought treatment than persons without these conditions (P = 0.0006). The survey results indicate that awareness of the causes of disease, the relationship between infection and disease, and goals of treatment must be heightened through community-based education campaigns to increase the possibility of acceptance and support of control programs.
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Affiliation(s)
- M L Eberhard
- Division of Parasitic Diseases, National Center for Infectious Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, USA
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Abstract
BB/Wor rats develop autoimmune diabetes mellitus with many features in common with human insulin-dependent diabetes mellitus. Since retinoids are known to have effects on insulin secretion and immune function, these studies were designed to investigate the effects of retinoid deficiency on diabetes in BB/Wor rats and to identify a role for retinoid status in the pathogenesis of autoimmune diabetes mellitus. Litters of diabetes-prone (DP) and diabetes-resistant (DR) BB/Wor rats were divided at weaning and fed a diet either (1) devoid of retinoids and leading to clinical deficiency at approximately 60 days of age (A-def diet)-following 10 days of clinical deficiency, rats on the A-def diet were changed to a diet containing 2 microg/g retinoic (A-def/RA diet); (2) containing 2 microg/g retinoic acid but deficient in retinol (RA diet); or (3) replete in retinol with 4 microg/g retinyl palmitate (RP diet). Rats receiving RP or RA diets were pair-fed to rats on the A-def/RA diet. Diabetes by 120 days of age was greatly reduced (P < .01) in DP rats that received the A-def/RA diet (four of 27) or RA diet (four of 29) versus the RP diet (13 of 31). Insulitis progressed with age in nondiabetic DP rats receiving the RP diet (P < .02) or RA diet (P < .05), but not the A-def/RA diet (P > .22). Insulin secretion was measured in perfused pancreas of nondiabetic rats after age 120 days and correlated negatively with insulitis (P < .05). DP rats receiving the RP diet had reduced insulin secretion as compared with other DP and DR rats (P < .05). In DR rats, retinoid status had no effects on insulitis through 120 days of age or on insulin secretion after 120 days of age. In conclusion, retinol deficiency reduces diabetes and insulitis in DP BB/Wor rats, and retinoic acid can at least partly substitute for retinol in the development of insulitis.
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Affiliation(s)
- H K Driscoll
- Department of Medicine, Marshall University School of Medicine, Huntington, WV 25703-1585, USA
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Eberhard ML, Walker EM, Steurer FJ. Survival and infectivity of Babesia in blood maintained at 25 C and 2-4 C. J Parasitol 1995; 81:790-2. [PMID: 7472878] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Babesia microti-infected blood was stored at room temperature (approximately 25 C) or refrigerated (4 C) for 30 days. To assess viability of the parasites after storage at these 2 temperatures, a 0.25-ml aliquot was inoculated into each of 2 hamsters in 2 separate experiments at days 3, 7, 10, 14, 17, 21, 25, and 30. Blood films were prepared and examined weekly for the presence of parasites from all hamsters. Of hamsters inoculated with blood held at room temperature, only those inoculated at day 3 became positive, whereas 4/4 hamsters inoculated with refrigerated blood on day 17 became parasitemic and 1/4 hamsters inoculated with blood held for 21 days became parasitemic. These results indicate that under blood banking conditions, this intracellular protozoan parasite can remain infective and transfusion-acquired infection with this parasite could occur throughout most of the time that blood is normally stored.
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Affiliation(s)
- M L Eberhard
- Centers for Disease Control and Prevention, Department of Health and Human Services, Atlanta, Georgia 30333, USA
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Walker EM, Shaw JP, Kaufman MH. Andrew Combe (1797-1847): Edinburgh physician and phrenologist. Proc R Coll Physicians Edinb 1995; 25:652-62. [PMID: 11608955] [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] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Affiliation(s)
- E M Walker
- Department of Anatomy, University of Edinburgh Medical School
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Abstract
OBJECTIVE To determine if traction on a catheter after transurethral resection of the prostate (TURP) reduces post-operative bleeding. PATIENTS AND METHODS This prospective trial included 115 consecutive patients undergoing TURP. After resection patients were randomly selected to have either traction (57) or no traction (58) on the catheter for 30 min. Blood loss was measured during and for 2 h after the operation. A simple method for applying constant traction is described. RESULTS Catheter traction reduced post-operative bleeding while applied, but had no further effect after the removal of traction. CONCLUSION Catheter traction is a useful technique to aid the control of post-TURP bleeding.
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Eberhard ML, Dickerson JW, Tsang VC, Walker EM, Ottesen EA, Chandrashekar R, Weil GJ, Trpis M, Strobert E, Constantinidis I. Onchocerca volvulus: parasitologic and serologic responses in experimentally infected chimpanzees and mangabey monkeys. Exp Parasitol 1995; 80:454-62. [PMID: 7729480 DOI: 10.1006/expr.1995.1057] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [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: 01/26/2023]
Abstract
Six chimpanzees (Pan troglodytes) and six mangabey monkeys (Cercocebus atys) were inoculated with Onchocerca volvulus third-stage larvae (L3) of West African origin. Two chimpanzees each received 200, 300, or 400 L3, while three mangabeys each received either 50 or 250 L3. All six chimpanzees became microfilaria positive between 11 and 25 months postinoculation (PI), while two of the six mangabeys were skin-snip positive at 24 and 37 months PI, respectively. All chimpanzees developed antibodies to two native antigens of 14 and 22 kDa and to the recombinant antigens OV16, OC3.6, and OC9.3. Marked antibody responses were observed in the mangabey monkeys, and in general, the responses were similar to those observed in the chimpanzees. However, in the mangabeys, these responses did not generally manifest themselves until later in the infection. The results of this study suggest that in chimpanzees, the smallest inoculum used, 200 L3, was sufficient to initiate consistent infections that had parasitologic and immunologic parameters equivalent to animals inoculated with larger numbers of larvae. Similarly, inoculation of mangabey monkeys with small numbers of larvae appeared to be as likely to establish infection and induce immunologic responses as did inoculation of larger numbers of larvae. Microfilaria-positive chimpanzees and mangabey monkeys were examined by three conventional imaging techniques (X ray, ultrasound, and magnetic resonance imaging (MRI)), but no adult worms or nodules could be identified in any animal.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- M L Eberhard
- Division of Parasitic Diseases F13, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA
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Walker EM, Howell JK, You Y, Hoffmaster AR, Heath JD, Weinstock GM, Norris SJ. Physical map of the genome of Treponema pallidum subsp. pallidum (Nichols). J Bacteriol 1995; 177:1797-804. [PMID: 7896703 PMCID: PMC176808 DOI: 10.1128/jb.177.7.1797-1804.1995] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.8] [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: 01/27/2023] Open
Abstract
A physical map of the chromosome of Treponema pallidum subsp. pallidum (Nichols), the causative agent of syphilis, was constructed from restriction fragments produced by NotI, SfiI, and SrfI. These rare-cutting restriction endonucleases cleaved the T. pallidum genome into 16, 8, and 15 fragments, respectively. Summation of the physical lengths of the fragments indicates that the chromosome of T. pallidum subsp. pallidum is approximately 1,030 to 1,080 kbp in size. The physical map was constructed by hybridizing a variety of probes to Southern blots of single and double digests of T. pallidum genomic DNA separated by contour-clamped homogeneous electric field electrophoresis. Probes included cosmid clones constructed from T. pallidum subsp. pallidum genomic DNA, restriction fragments excised from gels, and selected genes. Physical mapping confirmed that the chromosome of T. pallidum subsp. pallidum is circular, as the SfiI and SrfI maps formed complete circles. A total of 13 genes, including those encoding five membrane lipoproteins (tpn47, tpn41, tpn29-35, tpn17, and tpn15), a putative outer membrane porin (tpn50), the flagellar sheath and hook proteins (flaA and flgE), the cytoplasmic filament protein (cfpA), 16S rRNA (rrnA), a major sigma factor (rpoD), and a homolog of cysteinyl-tRNA synthetase (cysS), have been localized in the physical map as a first step toward studying the genetic organization of this noncultivable pathogen.
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Affiliation(s)
- E M Walker
- Department of Pathology and Laboratory Medicine, University of Texas Medical School at Houston 77225
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Lewinski MA, Miller JN, Champion CI, Walker EM, Borenstein LA, Gayek RJ, Lovett MA, Blanco DR. Treponemicidal antibody measured by the "washed-killing" assay correlates with immunity in experimental rabbit syphilis. Sex Transm Dis 1995; 22:31-8. [PMID: 7709323 DOI: 10.1097/00007435-199501000-00006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [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: 01/26/2023]
Abstract
BACKGROUND AND OBJECTIVES The authors have previously shown that complement-dependent treponemicidal antibody measured by the "washed-killing" assay is directed exclusively against surface-exposed targets on Treponema pallidum, presumably the Treponema pallidum rare outer membrane proteins detected by freeze-fracture electron microscopy. GOAL OF THIS STUDY Because immune mechanisms against Treponema pallidum rare outer membrane proteins are likely to be central to a protective host response, it was examined whether a relationship could be established between treponemicidal levels as measured by the "washed-killing" assay and host immunity in experimental syphilis. STUDY DESIGN Three groups of Treponema pallidum-infected rabbits were treated curatively with penicillin at 9 days, 30 days, and 6 months post-infection to generate animals with varying degrees of immunity to challenge re-infection. The level of complement-dependent treponemicidal activity in sera obtained before infection (basal) and before intradermal challenge was determined by the "washed-killing" assay and compared with that detected using conventional in vitro immobilization. RESULTS Using the "washed-killing" assay, a close quantitative correlation as measured by a treponemal immobilizing endpoint titer was demonstrable between prechallenge treponemicidal antibody and the status of immunity to re-infection. Sera from rabbits completely susceptible to symptomatic and disseminated asymptomatic re-infection lacked treponemicidal antibody. Sera from challenged rabbits with a relatively low degree of immunity to symptomatic disease showed endpoints of < or = 4. Rabbits with a relatively high degree of immunity to symptomatic reinfection and resistant to disseminated disease had endpoints that ranged from 6 to 96. Rabbits completely resistant to challenge exhibited endpoints ranging from 96 to 128. CONCLUSION Treponemicidal antibody measured by the "washed-killing" assay correlated closely with the status of immunity in experimental rabbit syphilis. Thus, antibody measured by this assay may be directed against key protective Treponema pallidum surface immunogens.
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Affiliation(s)
- M A Lewinski
- Department of Microbiology and Immunology, University of California School of Medicine, Los Angeles 90024
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Abstract
In the search for 3-hydroxypyrid-4-ones with enhanced iron-mobilizing ability, seven chiral, anionic amino acid derivatives of maltol (3-hydroxy-2-methyl-4-pyrone) have been synthesized, utilizing L-methionine, L-serine, L-leucine, L-phenylalanine, L-glutamic acid, and the D- and L-isomers of alanine. Two achiral, aromatic compounds were also synthesized and compared with the phenylalanine derivative. The biliary iron excretion following iv injection and the urinary iron excretion following po administration were measured using female Sprague-Dawley rats and compared to that of the standard, 1,2-dimethyl-3-hydroxypyrid-4-one (L1). While none of the compounds was as effective as L1 in enhancing the urinary excretion of iron, all monoanionic chelators increased excretion relative to the controls. All monoanionic compounds were at least equivalent to L1 in enhancing the biliary excretion of iron, with the methionine, leucine, and benzoate derivatives surpassing the standard and the other aromatic compounds also showing strong activity. The dianionic glutamate derivative showed low activity relative to the controls for both urinary and biliary iron excretion. No significant difference in iron excretion was observed due to variation in chirality; molecular weight and the number of negative charges appeared to have the greatest influence on the ability of the various derivatives to enhance iron excretion. In order to evaluate the relative purity of the stereoisomers, the alanine derivatives were analyzed by circular dichroism. Further characterization was provided by UV/vis spectroscopy for all compounds and X-ray crystallography for the novel dianionic derivative.
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Affiliation(s)
- J J Molenda
- Department of Chemistry, Vanderbilt University, Nashville, Tennessee 37235
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45
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Jones MH, Khwaja OS, Briggs H, Lambson B, Davey PM, Chalmers J, Zhou CY, Walker EM, Zhang Y, Todd C. A set of ninety-seven overlapping yeast artificial chromosome clones spanning the human Y chromosome euchromatin. Genomics 1994; 24:266-75. [PMID: 7698748 DOI: 10.1006/geno.1994.1615] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.3] [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: 01/26/2023]
Abstract
Contiguous arrays of yeast artificial chromosomes (YACs) extending from proximal heterochromatic Yq into the pseudoautosomal portion of the Y chromosome and separated by a small interval at the centromere have been constructed. A total of 97 YACs have been aligned along the Y chromosome by STS content analysis using 222 sequence tagged sites (STSs) that detect 263 loci. Forty-five of the STSs used are novel. Their inclusion provides a significant improvement over previously available maps on the density of STS coverage along the Y chromosome, reducing the average spacing to 120 kb assuming a length of 30 Mb for the euchromatin. The average size of 61 YACs determined by pulsed-field gel electrophoresis analysis was at least 0.9 Mb. Minor differences noted between the ordering of STSs on this map compared with those previously reported may be attributed to inherent polymorphism between the Y chromosomes used to construct the YAC libraries.
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Affiliation(s)
- M H Jones
- University of Cambridge Department of Pathology, United Kingdom
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46
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Yee S, Fazekas-May M, Walker EM, Montague D, Stern S, Heard KW. Inhibition of cisplatin toxicity without decreasing antitumor efficacy. Use of a dithiocarbamate. Arch Otolaryngol Head Neck Surg 1994; 120:1248-52. [PMID: 7917209 DOI: 10.1001/archotol.1994.01880350056010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
OBJECTIVE To demonstrate whether a dithiocarbamate derivative, N-methyl-D-glucaminedithiocarbamate, could prevent anorexia and weight loss and enhance survival without decreasing the antitumor efficacy of high-dose cisplatin therapy. DESIGN One hundred forty-two mice were randomized into groups receiving cisplatin, 5 mg/kg per day, 7.5 mg/kg per day, or 10 mg/kg per day for three days with or without N-methyl-D-glucaminedithiocarbamate, 1000 mg/kg per day. Weight loss and morbidity were examined between groups. Antitumor efficacy of cisplatin combined with N-methyl-D-glucaminedithiocarbamate was examined using a subcutaneous melanoma model. SETTING Institutional laboratory. MAIN OUTCOME MEASURES N-methyl-D-glucaminedithiocarbamate intervention would decrease morbidity, weight loss, and increase survival without decreasing the antitumor efficacy of cisplatin. RESULTS Weight loss and morbidity were significantly reduced when N-methyl-D-glucaminedithiocarbamate was coadministered with cisplatin (P < .05) at all doses of cisplatin. The antitumor efficacy of high-dose cisplatin therapy (7.5 mg/kg per day and 10 mg/kg per day) was not significantly decreased (P > .05) at all doses of cisplatin. CONCLUSION As N-methyl-D-glucaminedithiocarbamate seems to limit morbidity and mortality of high-dose cisplatin administration without decreasing its antitumor efficacy, this drug deserves further investigation in the treatment of cancer.
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Affiliation(s)
- S Yee
- Department of Otolaryngology, University of Arkansas for Medical Sciences, Little Rock
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47
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Walker EM, Fazekas-May MA, Heard KW, Yee S, Montague D, Jones MM. Prevention of cisplatin-induced toxicity by selected dithiocarbamates. Ann Clin Lab Sci 1994; 24:121-33. [PMID: 8203821] [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
Cisplatin (CDDP) is a widely used antineoplastic agent, the administration of which is associated with dose-related toxicities. Currently, ototoxicity is the dose-limiting toxicity of cisplatin and difficult to prevent. The purpose of this study was to determine the ability of two substituted dithiocarbamates, diethyldithiocarbamate (DDTC) and N-methyl-D-glucaminedithiocarbamate (NMGDTC) to abrogate cisplatin-induced toxicity in young female Hartley albino guinea pigs. The animals were divided into saline controls, CDDP only, NMGDTC only, and CDDP-DDTC or CDDP-NMGDTC combinations with DDTC or NMGDTC given 30 minutes before or 30 minutes after CDDP. Auditory brainstem responses (ABR) were recorded periodically in sound-attenuated rooms to assess hearing thresholds. Representative cochleas were harvested at autopsy, processed, and examined by scanning electron microscopy (SEM). The NMGDTC produced marked reduction of CDDP-induced ototoxicity and weight loss. No significant ABR shift was found regardless of the order of CDDP and NMGDTC administration, but the derivative was more effective in preventing anorexia and weight loss when given prior to CDDP. Specifically, groups of guinea pigs given NMGDTC prior to CDDP showed the only weight gain among the treatment groups. Diethyldithiocarbamate, the other dithiocarbamate evaluated in this study, did not provide protection from cisplatin ototoxicity regardless of the order of administration. A CDDP-induced weight loss was reduced when DDTC was administered prior to CDDP. In summary, NMGDTC given prior to CDDP offers remarkable protection against cisplatin-induced ototoxicity and weight loss. It may help eliminate dose-limiting cisplatin-induced toxicity and allow the use of cisplatin at higher doses in cancer chemotherapy.
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Affiliation(s)
- E M Walker
- Department of Pathology, Marshall University School of Medicine, Huntington, WV 25755
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48
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Abstract
An unusual case of a lady with seropositive erosive RA, treated for 5 yr with sulphasalazine. She then developed SLE which resolved after stopping the drug. This case is reported with a short review of the literature.
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Affiliation(s)
- E M Walker
- Department of Rheumatology, Lincoln County Hospital
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49
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Abstract
The genome structures of several pathogenic spirochetes have recently been determined. The genomes of Borrelia species consist of a linear chromosome of approximately one million base pairs (Mb) and various linear and circular plasmids. Analysis of restriction fragment length polymorphisms and 16S ribosomal RNA sequence data indicate the division of Borrelia burgdorferi into at least three distinct genetic groups. Leptospira interrogans has a circular chromosome 5 Mb in size and a 0.35 Mb extrachromosomal element. Repetitive sequence elements similar to insertion sequences have been identified in the Leptospira interrogans genome. The chromosome of Treponema pallidum subsp. pallidum is circular and has a size of approximately one Mb. Genetic studies conducted to date indicate that B. burgdorferi and L. interrogans have a high degree of genetic diversity, whereas remarkably few genetic differences have been observed among the pathogenic Treponema. Knowledge of the genomic structure of these organisms will serve as a basis for future genetic studies.
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Affiliation(s)
- I Saint Girons
- Unité de Bactériologie Moléculaire et Médicale, Institut Pasteur, Paris, France
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50
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Gale GR, Walker EM, Smith AB, Jones MM, Stone A, Basinger MA, Singh PK. N-benzyl-N-lactyl dithiocarbamate treatment of mice after chronic cadmium administration. Arch Toxicol 1992; 66:713-8. [PMID: 1290404 DOI: 10.1007/bf01972622] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [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: 12/26/2022]
Abstract
Administration of N-benzyl-N-lactyl dithiocarbamate (BLDTC) to mice after chronic cadmium (Cd) administration evoked a prompt, dose-dependent reduction of the whole body burden; 75% of the retained Cd was mobilized and excreted after 20 i.p. injections of BLDTC at 1.0 mmol/kg/injection. This same dose regimen produced 71% and 98% reductions of the renal and hepatic Cd concentrations, respectively. There was no reduction by BLDTC of the endogenous level of any of seven other metals measured: iron, magnesium, selenium, copper, calcium, zinc, and manganese. Renal proximal tubular damage in mice which received Cd followed by BLDTC was much less than that observed in kidneys from mice which received Cd alone. Chronic Cd administration led to substantial epithelial vacuolar damage to renal distal tubules, and this process was not apparently reversed or antagonized by BLDTC treatment to the extent observed in proximal tubules.
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Affiliation(s)
- G R Gale
- Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, SC 29401
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