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Muscat SM, Butler MJ, Bettes MN, DeMarsh JW, Scaria EA, Deems NP, Barrientos RM. Post-operative cognitive dysfunction is exacerbated by high-fat diet via TLR4 and prevented by dietary DHA supplementation. Brain Behav Immun 2024; 116:385-401. [PMID: 38145855 PMCID: PMC10872288 DOI: 10.1016/j.bbi.2023.12.028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2023] [Revised: 12/04/2023] [Accepted: 12/20/2023] [Indexed: 12/27/2023] Open
Abstract
Post-operative cognitive dysfunction (POCD) is an abrupt decline in neurocognitive function arising shortly after surgery and persisting for weeks to months, increasing the risk of dementia diagnosis. Advanced age, obesity, and comorbidities linked to high-fat diet (HFD) consumption such as diabetes and hypertension have been identified as risk factors for POCD, although underlying mechanisms remain unclear. We have previously shown that surgery alone, or 3-days of HFD can each evoke sufficient neuroinflammation to cause memory deficits in aged, but not young rats. The aim of the present study was to determine if HFD consumption before surgery would potentiate and prolong the subsequent neuroinflammatory response and memory deficits, and if so, to determine the extent to which these effects depend on activation of the innate immune receptor TLR4, which both insults are known to stimulate. Young-adult (3mo) & aged (24mo) male F344xBN F1 rats were fed standard chow or HFD for 3-days immediately before sham surgery or laparotomy. In aged rats, the combination of HFD and surgery caused persistent deficits in contextual memory and cued-fear memory, though it was determined that HFD alone was sufficient to cause the long-lasting cued-fear memory deficits. In young adult rats, HFD + surgery caused only cued-fear memory deficits. Elevated proinflammatory gene expression in the hippocampus of both young and aged rats that received HFD + surgery persisted for at least 3-weeks after surgery. In a separate experiment, rats were administered the TLR4-specific antagonist, LPS-RS, immediately before HFD onset, which ameliorated the HFD + surgery-associated neuroinflammation and memory deficits. Similarly, dietary DHA supplementation for 4 weeks prior to HFD onset blunted the neuroinflammatory response to surgery and prevented development of persistent memory deficits. These results suggest that HFD 1) increases risk of persistent POCD-associated memory impairments following surgery in male rats in 2) a TLR4-dependent manner, which 3) can be targeted by DHA supplementation to mitigate development of persistent POCD.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA
| | - Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - James W DeMarsh
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Emmanuel A Scaria
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Department of Psychiatry & Behavioral Health, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH, USA.
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Butler MJ, Sengupta S, Muscat S, Amici SA, Biltz RG, Deems NP, Dravid P, Mackey-Alfonso S, Ijaz H, Bettes MN, Godbout JP, Kapoor A, Guerau-de-Arellano M, Barrientos RM. Corrigendum to "CD8 + T cells contribute to diet-induced memory deficits in aged male rats" [Brain Behav. Immun. 109 (2023) 235-250]. Brain Behav Immun 2023; 113:476-477. [PMID: 37003947 DOI: 10.1016/j.bbi.2023.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
Affiliation(s)
- Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA.
| | - Shouvonik Sengupta
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie A Amici
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Rebecca G Biltz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Piyush Dravid
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Sabrina Mackey-Alfonso
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Haanya Ijaz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Jonathan P Godbout
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Departments of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
| | - Amit Kapoor
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Mireia Guerau-de-Arellano
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Departments of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Departments of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
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Butler MJ, Mackey-Alfonso SE, Massa N, Baskin KK, Barrientos RM. Dietary fatty acids differentially impact phagocytosis, inflammatory gene expression, and mitochondrial respiration in microglial and neuronal cell models. Front Cell Neurosci 2023; 17:1227241. [PMID: 37636589 PMCID: PMC10448530 DOI: 10.3389/fncel.2023.1227241] [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] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/27/2023] [Indexed: 08/29/2023] Open
Abstract
The consumption of diets high in saturated fatty acids and/or refined carbohydrates are associated with neuroinflammation, cognitive dysfunction, and neurodegenerative disease. In contrast, diets high in polyunsaturated fatty acids are associated with anti-inflammatory and neuroprotective effects. We have previously shown that high fat diet (HFD) consumption increases saturated fatty acids and decreases polyunsaturated fatty acids in the hippocampus. We have further shown that HFD elicits exaggerated neuroinflammation and reduced synaptic elements, and results in robust memory deficits in aged rats. Here, we examined the impact of palmitate, an abundant dietary saturated fat, on a variety of cellular responses in BV2 microglia and HippoE-14 neurons, and the extent to which the omega-3 fatty acid, docosahexaenoic acid (DHA), would buffer against these responses. Our data demonstrate that DHA pretreatment prevents or partially attenuates palmitate-induced alterations in proinflammatory, endoplasmic reticulum stress, and mitochondrial damage-associated gene expression in both cell types. Furthermore, we show that synaptoneurosomes isolated from aged, HFD-fed mice are engulfed by BV2 microglia at a faster rate than synaptoneurosomes isolated from aged, chow-fed mice, suggesting HFD alters signaling at synapses to hasten their engulfment by microglia. Consistent with this notion, we found modest increases in complement proteins and a decrease in CD47 protein expression on synaptoneurosomes isolated from the hippocampus of aged, HFD-fed mice. Interestingly, palmitate reduced BV2 microglial phagocytosis, but only of synaptoneurosomes isolated from chow-fed mice, an effect that was prevented by DHA pretreatment. Lastly, we measured the impact of palmitate and DHA on mitochondrial function in both microglial and neuronal cell models using the Seahorse XFe96 Analyzer. These data indicate that DHA pretreatment does not mitigate palmitate-induced reductions in mitochondrial respiration in BV2 microglia and HippoE-14 neurons, suggesting DHA may be acting downstream of mitochondrial function to exert its protective effects. Together, this study provides evidence that DHA can ameliorate the negative impact of palmitate on a variety of cellular functions in microglia- and neuron-like cells.
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Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
- Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, United States
| | - Sabrina E. Mackey-Alfonso
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
- Medical Scientist Training Program, The Ohio State University, Columbus, OH, United States
| | - Nashali Massa
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
| | - Kedryn K. Baskin
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University, Columbus, OH, United States
| | - Ruth M. Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, United States
- Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, United States
- Department of Neuroscience, The Ohio State University, Columbus, OH, United States
- Chronic Brain Injury Program, The Ohio State University, Columbus, OH, United States
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Butler MJ, Sloof D, Peters C, Conway Morris A, Gouliouris T, Thaxter R, Keevil VL, Beggs CB. Impact of supplementary air filtration on aerosols and particulate matter in a UK hospital ward: a case study. J Hosp Infect 2023; 135:81-89. [PMID: 36842537 PMCID: PMC9957342 DOI: 10.1016/j.jhin.2023.02.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 02/28/2023]
Abstract
BACKGROUND Aerosol spread of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is a major problem in hospitals, leading to an increase in supplementary high-efficiency particulate air filtration aimed at reducing nosocomial transmission. This article reports a natural experiment that occurred when an air cleaning unit (ACU) on a medicine for older people ward was switched off accidentally while being commissioned. AIM To assess aerosol transport within the ward and determine whether the ACU reduced airborne particulate matter (PM) levels. METHODS An ACU was placed in a ward comprising two six-bedded bays plus three single-bed isolation rooms which had previously experienced several outbreaks of coronavirus disease 2019. During commissioning, real-time measurements of key indoor air quality parameters (PM1-10, CO2, temperature and humidity) were collected from multiple sensors over 2 days. During this period, the ACU was switched off accidentally for approximately 7 h, allowing the impact of the intervention on PM to be assessed. FINDINGS The ACU reduced the PM counts considerably (e.g. PM1 65.5-78.2%) throughout the ward (P<0.001 all sizes), with positive correlation found for all PM fractions and CO2 (r=0.343-0.817; all P<0.001). PM counts rose/fell simultaneously when the ACU was off, with correlation of PM signals from multiple locations (e.g. r=0.343-0.868; all P<0.001) for particulates <1 μm). CONCLUSION Aerosols migrated rapidly between the various ward subcompartments, suggesting that social distancing alone cannot prevent nosocomial transmission of SARS-CoV-2 as this fails to mitigate longer-range (>2 m) transmission. The ACU reduced PM levels considerably throughout the ward space, indicating its potential as an effective intervention to reduce the risk posed by infectious airborne particles.
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Affiliation(s)
- M J Butler
- Department of Medicine for the Elderly, Cambridge University Hospitals, Cambridge, UK
| | - D Sloof
- AirPurity UK, Ltd, Cambridge, UK
| | - C Peters
- Department of Microbiology, NHS Greater Glasgow and Clyde, Glasgow, UK
| | - A Conway Morris
- John V Farman Intensive Care Unit, Cambridge University Hospitals, Cambridge, UK; Division of Immunology, Department of Pathology, University of Cambridge, Cambridge, UK; Department of Medicine, University of Cambridge, Cambridge, UK
| | - T Gouliouris
- Department of Medicine, University of Cambridge, Cambridge, UK
| | - R Thaxter
- Infection Prevention and Control, Cambridge University Hospitals, Cambridge, UK
| | - V L Keevil
- Department of Medicine for the Elderly, Cambridge University Hospitals, Cambridge, UK; Department of Medicine, University of Cambridge, Cambridge, UK
| | - C B Beggs
- Department of Medicine for the Elderly, Cambridge University Hospitals, Cambridge, UK; Carnegie School of Sport, Leeds Beckett University, Leeds, UK.
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Muscat SM, Butler MJ, Mackey-Alfonso SE, Barrientos RM. Young adult and aged female rats are vulnerable to amygdala-dependent, but not hippocampus-dependent, memory impairment following short-term high-fat diet. Brain Res Bull 2023; 195:145-156. [PMID: 36870621 PMCID: PMC10257807 DOI: 10.1016/j.brainresbull.2023.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [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: 10/31/2022] [Revised: 02/18/2023] [Accepted: 03/01/2023] [Indexed: 03/06/2023]
Abstract
Global populations are increasingly consuming diets high in saturated fats and refined carbohydrates, and such diets have been well-associated with heightened inflammation and neurological dysfunction. Notably, older individuals are particularly vulnerable to the impact of unhealthy diet on cognition, even after a single meal, and pre-clinical rodent studies have demonstrated that short-term consumption of high-fat diet (HFD) induces marked increases in neuroinflammation and cognitive impairment. Unfortunately though, to date, most studies on the topic of nutrition and cognition, especially in aging, have been performed only in male rodents. This is especially concerning given that older females are more vulnerable to develop certain memory deficits and/or severe memory-related pathologies than males. Thus, the aim of the present study was to determine the extent to which short-term HFD consumption impacts memory function and neuroinflammation in female rats. Young adult (3 months) and aged (20-22 months) female rats were fed HFD for 3 days. Using contextual fear conditioning, we found that HFD had no effect on long-term contextual memory (hippocampus-dependent) at either age, but impaired long-term auditory-cued memory (amygdala-dependent) regardless of age. Gene expression of Il-1β was markedly dysregulated in the amygdala, but not hippocampus, of both young and aged rats after 3 days of HFD. Interestingly, modulation of IL-1 signaling via central administration of the IL-1 receptor antagonist (which we have previously demonstrated to be protective in males) had no impact on memory function following the HFD in females. Investigation of the memory-associated gene Pacap and its receptor Pac1r revealed differential effects of HFD on their expression in the hippocampus and amygdala. Specifically, HFD induced increased expression of Pacap and Pac1r in the hippocampus, whereas decreased Pacap was observed in the amygdala. Collectively, these data suggest that both young adult and aged female rats are vulnerable to amygdala-dependent (but not hippocampus-dependent) memory impairments following short-term HFD consumption, and identify potential mechanisms related to IL-1β and PACAP signaling in these differential effects. Notably, these findings are strikingly different than those previously reported in male rats using the same diet regimen and behavioral paradigms, and highlight the importance of examining potential sex differences in the context of neuroimmune-associated cognitive dysfunction.
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Affiliation(s)
- Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Sabrina E Mackey-Alfonso
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Medical Scientist Training Program, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH, USA.
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Butler MJ, Sengupta S, Muscat SM, Amici SA, Biltz RG, Deems NP, Dravid P, Mackey-Alfonso S, Ijaz H, Bettes MN, Godbout JP, Kapoor A, Guerau-de-Arellano M, Barrientos RM. CD8 + T cells contribute to diet-induced memory deficits in aged male rats. Brain Behav Immun 2023; 109:235-250. [PMID: 36764399 PMCID: PMC10124165 DOI: 10.1016/j.bbi.2023.02.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/27/2023] [Accepted: 02/03/2023] [Indexed: 02/11/2023] Open
Abstract
We have previously shown that short-term (3-day) high fat diet (HFD) consumption induces a neuroinflammatory response and subsequent impairment of long-term memory in aged, but not young adult, male rats. However, the immune cell phenotypes driving this proinflammatory response are not well understood. Previously, we showed that microglia isolated from young and aged rats fed a HFD express similar levels of priming and proinflammatory transcripts, suggesting that additional factors may drive the exaggerated neuroinflammatory response selectively observed in aged HFD-fed rats. It is established that T cells infiltrate both the young and especially the aged central nervous system (CNS) and contribute to immune surveillance of the parenchyma. Thus, we investigated the modulating role of short-term HFD on T cell presence in the CNS in aged rats using bulk RNA sequencing and flow cytometry. RNA sequencing results indicate that aging and HFD altered the expression of genes and signaling pathways associated with T cell signaling, immune cell trafficking, and neuroinflammation. Moreover, flow cytometry data showed that aging alone increased CD4+ and CD8+ T cell presence in the brain and that CD8+, but not CD4+, T cells were further increased in aged rats fed a HFD. Based on these data, we selectively depleted circulating CD8+ T cells via an intravenous injection of an anti-CD8 antibody in aged rats prior to 3 days of HFD to infer the functional role these cells may be playing in long-term memory and neuroinflammation. Results indicate that peripheral depletion of CD8+ T cells lowered hippocampal cytokine levels and prevented the HFD-induced i) increase in brain CD8+ T cells, ii) memory impairment, and iii) alterations in pre- and post-synaptic structures in the hippocampus and amygdala. Together, these data indicate a substantial role for CD8+ T cells in mediating diet-induced memory impairments in aged male rats.
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Affiliation(s)
- Michael J Butler
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA.
| | - Shouvonik Sengupta
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie M Muscat
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Biomedical Sciences Graduate Program, College of Medicine, The Ohio State University, Columbus, OH, USA
| | - Stephanie A Amici
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Rebecca G Biltz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Piyush Dravid
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Sabrina Mackey-Alfonso
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Neuroscience Graduate Program, The Ohio State University, Columbus, OH, USA
| | - Haanya Ijaz
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Menaz N Bettes
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA
| | - Jonathan P Godbout
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
| | - Amit Kapoor
- College of Medicine, The Ohio State University, Columbus, OH 43210, USA; Center for Vaccines and Immunity, The Research Institute at Nationwide Children's Hospital, Columbus, OH 43205, USA
| | - Mireia Guerau-de-Arellano
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, The Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, The Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH 43210, USA; Chronic Brain Injury Program, The Ohio State University, Columbus, OH 43210, USA
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Butler MJ, Deems NP, Muscat S, Butt CM, Belury MA, Barrientos RM. Dietary DHA prevents cognitive impairment and inflammatory gene expression in aged male rats fed a diet enriched with refined carbohydrates. Brain Behav Immun 2021; 98:198-209. [PMID: 34425209 PMCID: PMC8511052 DOI: 10.1016/j.bbi.2021.08.214] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [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: 06/24/2021] [Revised: 08/02/2021] [Accepted: 08/07/2021] [Indexed: 12/12/2022] Open
Abstract
The consumption of a processed foods diet (PD) enriched with refined carbohydrates, saturated fats, and lack of fiber has increased in recent decades and likely contributed to increased incidence of chronic disease and weight gain in humans. These diets have also been shown to negatively impact brain health and cognitive function in rodents, non-human primates, and humans, potentially through neuroimmune-related mechanisms. However, mechanisms by which PD impacts the aged brain are unknown. This gap in knowledge is critical, considering the aged brain has a heightened state of baseline inflammation, making it more susceptible to secondary challenges. Here, we showed that consumption of a PD, enriched with refined carbohydrate sources, for 28 days impaired hippocampal- and amygdalar-dependent memory function in aged (24 months), but not young (3 months) F344 × BN rats. These memory deficits were accompanied by increased expression of inflammatory genes, such as IL-1β, CD11b, MHC class II, CD86, NLRP3, and complement component 3, in the hippocampus and amygdala of aged rats. Importantly, we also showed that when the same PD is supplemented with the omega-3 polyunsaturated fatty acid DHA, these memory deficits and inflammatory gene expression changes were ameliorated in aged rats, thus providing the first evidence that DHA supplementation can protect against memory deficits and inflammatory gene expression in aged rats fed a processed foods diet. Lastly, we showed that while PD consumption increased weight gain in both young and aged rats, this effect was exaggerated in aged rats. Aging was also associated with significant alterations in hypothalamic gene expression, with no impact by DHA on weight gain or hypothalamic gene expression. Together, our data provide novel insights regarding diet-brain interactions by showing that PD consumption impairs cognitive function likely through a neuroimmune mechanism and that dietary DHA can ameliorate this phenomenon.
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Affiliation(s)
- Michael J Butler
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Nicholas P Deems
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Stephanie Muscat
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | | | - Martha A Belury
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA; Department of Human Sciences, Ohio State University, Columbus, OH, USA
| | - Ruth M Barrientos
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA; Department of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, USA; Department of Neuroscience, The Ohio State University, Columbus, OH, USA; Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, USA.
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Butler MJ. The role of Western diets and obesity in peripheral immune cell recruitment and inflammation in the central nervous system. Brain Behav Immun Health 2021; 16:100298. [PMID: 34589790 PMCID: PMC8474237 DOI: 10.1016/j.bbih.2021.100298] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 07/09/2021] [Accepted: 07/10/2021] [Indexed: 12/25/2022] Open
Abstract
As the prevalence of obesity and chronic disease increases, the role of nutrition is taking center stage as a potential root cause of not just metabolic-related illnesses, but also of disorders of the central nervous system (CNS). Consumption of a modern, westernized diet, such as a high fat diet (HFD) that contains excess saturated fatty acids (SFAs), refined carbohydrates, and ultra-processed ingredients has been shown to induce neuroinflammation in multiple brain regions important for energy homeostasis, cognitive function, and mood regulation in rodents, non-human primates, and humans. This review article summarizes the literature showing Western diets, via SFA increases, can increase the reactivity and alter the function of multiple types of immune cells from both the innate and adaptive branches of the immune system, with a specific focus on microglia, macrophages, dendritic cells, and T-cells. These changes in immune and neuroimmune signaling have important implications for neuroinflammation and brain health and will be an important factor in future psychoneuroimmunology research.
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Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, Ohio State University, Wexner Medical Center 460 Medical Center Drive, Columbus, OH, 43210, USA
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Butler MJ, Perrini AA, Eckel LA. The Role of the Gut Microbiome, Immunity, and Neuroinflammation in the Pathophysiology of Eating Disorders. Nutrients 2021; 13:nu13020500. [PMID: 33546416 PMCID: PMC7913528 DOI: 10.3390/nu13020500] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2020] [Revised: 01/19/2021] [Accepted: 01/29/2021] [Indexed: 12/23/2022] Open
Abstract
There is a growing recognition that both the gut microbiome and the immune system are involved in a number of psychiatric illnesses, including eating disorders. This should come as no surprise, given the important roles of diet composition, eating patterns, and daily caloric intake in modulating both biological systems. Here, we review the evidence that alterations in the gut microbiome and immune system may serve not only to maintain and exacerbate dysregulated eating behavior, characterized by caloric restriction in anorexia nervosa and binge eating in bulimia nervosa and binge eating disorder, but may also serve as biomarkers of increased risk for developing an eating disorder. We focus on studies examining gut dysbiosis, peripheral inflammation, and neuroinflammation in each of these eating disorders, and explore the available data from preclinical rodent models of anorexia and binge-like eating that may be useful in providing a better understanding of the biological mechanisms underlying eating disorders. Such knowledge is critical to developing novel, highly effective treatments for these often intractable and unremitting eating disorders.
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Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH 43210, USA;
| | - Alexis A. Perrini
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA;
| | - Lisa A. Eckel
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA;
- Correspondence: ; Tel.: +1-850-644-3480
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Butler MJ, Barrientos RM. Reply to the Letter to the Editor: Regional differences in dietary use of immune-modulating catechins should be investigated regarding COVID-19. Brain Behav Immun 2020; 89:528. [PMID: 32679174 PMCID: PMC7362785 DOI: 10.1016/j.bbi.2020.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 07/10/2020] [Indexed: 11/15/2022] Open
Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, United States
| | - Ruth M. Barrientos
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, United States,Department of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, United States,Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, United States,Department of Neuroscience, Ohio State University, Columbus, OH, United States,Corresponding author at: Institute for Behavioral Medicine Research and Department of Psychiatry and Behavioral Health, Ohio State University, 460 Medical Center Drive, Columbus, OH 43210, United States
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11
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Butler MJ, Cole RM, Deems NP, Belury MA, Barrientos RM. Fatty food, fatty acids, and microglial priming in the adult and aged hippocampus and amygdala. Brain Behav Immun 2020; 89:145-158. [PMID: 32544595 PMCID: PMC7572563 DOI: 10.1016/j.bbi.2020.06.010] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2020] [Revised: 05/20/2020] [Accepted: 06/06/2020] [Indexed: 02/08/2023] Open
Abstract
Short-term (3-day) consumption of a high fat diet (HFD) rich in saturated fats is associated with a neuroinflammatory response and subsequent cognitive impairment in aged, but not young adult, male rats. This exaggerated effect in aged rats could be due to a "primed" microglial phenotype observed in the normal aging process in rodents in which aged microglia display a potentiated response to immune challenge. Here, we investigated the impact of HFD on microglial priming and lipid composition in the hippocampus and amygdala of young and aged rats. Furthermore, we investigated the microglial response to palmitate, the main saturated fatty acid (SFA) found in HFD that is proinflammatory. Our results indicate that HFD increased gene expression of microglial markers of activation indicative of microglial priming, including CD11b, MHCII, CX3CR1, and NLRP3, as well as the pro-inflammatory marker IL-1β in both hippocampus and amygdala-derived microglia. Furthermore, HFD increased the concentration of SFAs and decreased the concentration of polyunsaturated fatty acids (PUFAs) in the hippocampus. We also observed a specific decrease in the anti-inflammatory PUFA docosahexaenoic acid (DHA) in the hippocampus and amygdala of aged rats. In a separate cohort of young and aged animals, isolated microglia from the hippocampus and amygdala exposed to palmitate in vitro induced an inflammatory gene expression profile mimicking the effects of HFD in vivo. These data suggest that palmitate may be a critical nutritional signal from the HFD that is directly involved in hippocampal and amygdalar inflammation. Interestingly, microglial activation markers were increased in response to HFD or palmitate in an age-independent manner, suggesting that HFD sensitivity of microglia, under these experimental conditions, is not the sole mediator of the exaggerated inflammatory response observed in whole tissue extracts from aged HFD-fed rats.
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Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Rachel M. Cole
- Department of Human Sciences, Ohio State University, Columbus, OH, USA
| | - Nicholas P. Deems
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA
| | - Martha A. Belury
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA,Department of Human Sciences, Ohio State University, Columbus, OH, USA
| | - Ruth M. Barrientos
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, USA,Department of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, USA,Department of Neuroscience, The Ohio State University, Columbus, OH, USA,Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, USA,Corresponding author: Dr. Ruth M. Barrientos, Institute for Behavioral Medicine Research and Department of Psychiatry and Behavioral Health, Ohio State University, 460 Medical Center Drive, Columbus, OH 43210, Tel.: 614-293-6591,
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12
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Butler MJ, Spruill TM, Johnson DA, Redline S, Sims M, Jenkins BC, Booth JN, Thomas SJ, Abdalla M, O'Brien EC, Mentz RJ, Ogedegbe G, Williams NJ. Suboptimal sleep and incident cardiovascular disease among African Americans in the Jackson Heart Study (JHS). Sleep Med 2020; 76:89-97. [PMID: 33129011 DOI: 10.1016/j.sleep.2020.09.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 07/28/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Suboptimal sleep, including insufficient/long sleep duration and poor sleep quality, is a risk factor for cardiovascular disease (CVD) common but there is little information among African Americans, a group with a disproportionate CVD burden. The current study examined the association between suboptimal sleep and incident CVD among African Americans. METHODS This study included 4,522 African Americans without CVD at baseline (2000-2004) of the Jackson Heart Study (JHS). Self-reported sleep duration was defined as very short (<6 h/night), short (6 h/night), recommended (7-8 h/night), and long (≥9 h/night). Participants' self-reported sleep quality was defined as "high" and "low" quality. Suboptimal sleep was defined by low quality sleep and/or insufficient/long sleep duration. Incident CVD was a composite of incident coronary heart disease and stroke. Associations between suboptimal sleep and incident CVD were examined using Cox proportional hazards models over 15 follow-up years with adjustment for predictors of CVD risk and obstructive sleep apnea. RESULTS Sample mean age was 54 years (SD = 13), 64% female and 66% reported suboptimal sleep. Suboptimal sleep was not associated with incident CVD after covariate adjustment [HR(95% CI) = 1.18(0.97-1.46)]. Long [HR(95%CI) = 1.32(1.02-1.70)] and very short [HR(95% CI) = 1.56(1.06-2.30)] sleep duration were associated with incident CVD relative to recommended sleep duration. Low quality sleep was not associated with incident CVD (p = 0.413). CONCLUSIONS Long and very short self-reported sleep duration but not self-reported sleep quality were associated with increased hazard of incident CVD.
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Affiliation(s)
- M J Butler
- NYU Grossman School of Medicine School of Medicine, New York, NY, USA
| | - T M Spruill
- NYU Grossman School of Medicine School of Medicine, New York, NY, USA
| | - D A Johnson
- Rollins School of Public Health, Emory University, Atlanta, GA, USA; Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - S Redline
- Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA; Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - M Sims
- University of Mississippi Medical Center, Jackson, MS, USA
| | - B C Jenkins
- Jackson State University School of Public Health, Jackson, MS, USA
| | - J N Booth
- University of Alabama at Birmingham, CTI Clinical Trials and Consulting Services, Inc., Covington, KY, Birmingham, AL, USA
| | - S J Thomas
- University of Alabama at Birmingham, CTI Clinical Trials and Consulting Services, Inc., Covington, KY, Birmingham, AL, USA
| | - M Abdalla
- Columbia University Medical Center, New York, NY, USA
| | - E C O'Brien
- Duke University School of Medicine, Durham, NC, USA
| | - R J Mentz
- Duke University School of Medicine, Durham, NC, USA
| | - G Ogedegbe
- NYU Grossman School of Medicine School of Medicine, New York, NY, USA
| | - N J Williams
- NYU Grossman School of Medicine School of Medicine, New York, NY, USA.
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Butler MJ, Barrientos RM. The impact of nutrition on COVID-19 susceptibility and long-term consequences. Brain Behav Immun 2020; 87:53-54. [PMID: 32311498 PMCID: PMC7165103 DOI: 10.1016/j.bbi.2020.04.040] [Citation(s) in RCA: 302] [Impact Index Per Article: 75.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Revised: 04/14/2020] [Accepted: 04/15/2020] [Indexed: 02/06/2023] Open
Abstract
While all groups are affected by the COVID-19 pandemic, the elderly, underrepresented minorities, and those with underlying medical conditions are at the greatest risk. The high rate of consumption of diets high in saturated fats, sugars, and refined carbohydrates (collectively called Western diet, WD) worldwide, contribute to the prevalence of obesity and type 2 diabetes, and could place these populations at an increased risk for severe COVID-19 pathology and mortality. WD consumption activates the innate immune system and impairs adaptive immunity, leading to chronic inflammation and impaired host defense against viruses. Furthermore, peripheral inflammation caused by COVID-19 may have long-term consequences in those that recover, leading to chronic medical conditions such as dementia and neurodegenerative disease, likely through neuroinflammatory mechanisms that can be compounded by an unhealthy diet. Thus, now more than ever, wider access to healthy foods should be a top priority and individuals should be mindful of healthy eating habits to reduce susceptibility to and long-term complications from COVID-19.
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Affiliation(s)
- Michael J. Butler
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, United States
| | - Ruth M. Barrientos
- Institute for Behavioral Medicine Research, Ohio State University, Columbus, OH, United States,Department of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, United States,Chronic Brain Injury Program, Discovery Themes Initiative, The Ohio State University, Columbus, OH, United States,Department of Neuroscience, Ohio State University, Columbus, OH, United States,Corresponding author at: Institute for Behavioral Medicine Research, and Department of Psychiatry and Behavioral Health, Ohio State University, 460 Medical Center Drive, Columbus, OH 43210, United States
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14
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Butler MJ, Perrini AA, Eckel LA. Estradiol treatment attenuates high fat diet-induced microgliosis in ovariectomized rats. Horm Behav 2020; 120:104675. [PMID: 31923417 PMCID: PMC7117977 DOI: 10.1016/j.yhbeh.2020.104675] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [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: 09/14/2019] [Revised: 11/20/2019] [Accepted: 12/28/2019] [Indexed: 01/03/2023]
Abstract
Consumption of a high fat diet (HFD) increases circulating free fatty acids, which can enter the brain and promote a state of microgliosis, as defined by a change in microglia number and/or morphology. Most studies investigating diet-induced microgliosis have been conducted in male rodents despite well-documented sex differences in the neural control of food intake and neuroimmune signaling. This highlights the need to investigate how sex hormones may modulate the behavioral and cellular response to HFD consumption. Estradiol is of particular interest since it exerts a potent anorexigenic effect and has both anti-inflammatory and neuroprotective effects in the brain. As such, the aim of the current study was to investigate whether estradiol attenuates the development of HFD-induced microgliosis in female rats. Estradiol- and vehicle-treated ovariectomized rats were fed either a low-fat chow diet or a 60% HFD for 4 days, after which they were perfused and brain sections were processed via immunohistochemistry for microglia-specific Iba1 protein. Four days of HFD consumption promoted microgliosis, as measured via an increase in the number of microglia in the arcuate nucleus (ARC) of the hypothalamus and nucleus of the solitary tract (NTS), and a decrease in microglial branching in the ARC, NTS, lateral hypothalamus (LH), and ventromedial hypothalamus. Estradiol replacement attenuated the HFD-induced changes in microglia accumulation and morphology in the ARC, LH, and NTS. We conclude that estradiol has protective effects against HFD-induced microgliosis in a region-specific manner in hypothalamic and hindbrain areas implicated in the neural control of food intake.
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Affiliation(s)
- Michael J Butler
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States; Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, 43210, United States
| | - Alexis A Perrini
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Lisa A Eckel
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States.
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15
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Small HJ, Huchin-Mian JP, Reece KS, Pagenkopp Lohan KM, Butler MJ, Shields JD. Parasitic dinoflagellate Hematodinium perezi prevalence in larval and juvenile blue crabs Callinectes sapidus from coastal bays of Virginia. Dis Aquat Organ 2019; 134:215-222. [PMID: 31169127 DOI: 10.3354/dao03371] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The parasitic dinoflagellate Hematodinium perezi infects the American blue crab Callinectes sapidus and other decapods along the Eastern seaboard and Gulf of Mexico coast of the USA. Large juvenile and adult blue crabs experience high mortality during seasonal outbreaks of H. perezi, but less is known about its presence in the early life history stages of this host. We determined the prevalence of H. perezi in megalopae and early benthic juvenile crabs from multiple locations along the Virginia portion of the Delmarva Peninsula. The DNA of H. perezi was not detected in any megalopae collected from several locations within the oceanic coastal bay complex in which H. perezi is found at high prevalence levels. However, prevalence levels were high in early benthic juveniles from 2 oceanic coastal embayments: South Bay and Cobb Bay. Prevalence levels were lower at locations within Chesapeake Bay, including Cherrystone Creek, Hungars Creek, and Pungoteague Creek. Sampling over different seasons and several consecutive years indicates that disease transmission occurs rapidly after megalopae settle in high-salinity bays along the Delmarva Peninsula during the late summer and fall. Infected juvenile crabs can overwinter with the parasite and, when subjected to increasing water temperatures in spring, infections progress rapidly, culminating in transmission to other crabs in late spring and early summer. In high-salinity embayments, H. perezi can reach high prevalence levels and may significantly affect recruitment of juvenile blue crabs into the adult fishery.
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Affiliation(s)
- H J Small
- Virginia Institute of Marine Science, William & Mary, PO Box 1346, Gloucester Point, VA 23062, USA
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16
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Affiliation(s)
- Michael J. Butler
- Department of Plant Sciences, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Alan W. Day
- Department of Plant Sciences, The University of Western Ontario, London, Ontario, N6A 5B7 Canada
| | - Joan M. Henson
- Department of Microbiology, Montana State University, Bozeman, Montana 59717
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17
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Butler MJ, Eckel LA. Eating as a motivated behavior: modulatory effect of high fat diets on energy homeostasis, reward processing and neuroinflammation. Integr Zool 2019; 13:673-686. [PMID: 29851251 DOI: 10.1111/1749-4877.12340] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Eating is a basic motivated behavior that provides fuel for the body and supports brain function. To ensure survival, the brain's feeding circuits are tuned to monitor peripheral energy balance and promote food-seeking behavior when energy stores are low. The brain's bias toward a positive energy state, which is necessary to ensure adequate nutrition during times of food scarcity, is evolutionarily conserved across mammalian species and is likely to drive overeating in the presence of a palatable, energy-dense diet. Animal models of diet-induced overeating have played a vital role in investigating how the drive to consume palatable food may override the homeostatic processes that serve to maintain energy balance. These animal models have provided valuable insights into the neurobiological mechanisms underlying homeostatic and non-homeostatic eating, motivation and food reward, and the development of obesity and related comorbidities. Here, we provide a brief review of this literature and discuss how diet-induced inflammation in the central nervous system impacts the neural control of food intake and regulation of body weight. The connection between diet and the immune system provides an exciting new direction for the study of ingestive behavior and the pathophysiology of obesity.
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Affiliation(s)
- Michael J Butler
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida, USA
| | - Lisa A Eckel
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, Florida, USA
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18
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Butler MJ, Hildebrandt RP, Eckel LA. Selective activation of estrogen receptors, ERα and GPER-1, rapidly decreases food intake in female rats. Horm Behav 2018; 103:54-61. [PMID: 29807036 PMCID: PMC6076327 DOI: 10.1016/j.yhbeh.2018.05.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 01/05/2018] [Revised: 04/26/2018] [Accepted: 05/24/2018] [Indexed: 10/14/2022]
Abstract
Many of estradiol's behavioral effects are mediated, at least partially, via extra-nuclear estradiol signaling. Here, we investigated whether two estrogen receptor (ER) agonists, targeting ERα and G protein-coupled ER-1 (GPER-1), can promote rapid anorexigenic effects. Food intake was measured in ovariectomized (OVX) rats at 1, 2, 4, and 22 h following subcutaneous (s.c.) injection of an ERα agonist (PPT; 0-200 μg/kg), a GPER-1 agonist (G-1; 0-1600 μg/kg), and a GPER-1 antagonist (G-36; 0-80 μg/kg). To investigate possible cross-talk between ERα and GPER-1, we examined whether GPER-1 blockade affects the anorexigenic effect of PPT. Feeding was monitored in OVX rats that received s.c. injections of vehicle or 40 μg/kg G-36 followed 30 min later by s.c. injections of vehicle or 200 μg/kg PPT. Selective activation of ERα and GPER-1 alone decreased food intake within 1 h of drug treatment, and feeding remained suppressed for 22 h following PPT treatment and 4 h following G-1 treatment. Acute administration of G-36 alone did not suppress feeding at any time point. Blockade of GPER-1 attenuated PPT's rapid (within 1 h) anorexigenic effect, but did not modulate PPT's ability to suppress food intake at 2, 4 and 22 h. These findings demonstrate that selective activation of ERα produces a rapid (within 1 h) decrease in food intake that is best explained by a non-genomic signaling pathway and thus implicates the involvement of extra-nuclear ERα. Our findings also provide evidence that activation of GPER-1 is both sufficient to suppress feeding and necessary for PPT's rapid anorexigenic effect.
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Affiliation(s)
- Michael J Butler
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Ryan P Hildebrandt
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States
| | - Lisa A Eckel
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, United States.
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19
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Stewart DR, Butler MJ, Harris G, Johnson LA, Radke WR. Estimating abundance of endangered fish by eliminating bias from non-constant detectability. ENDANGER SPECIES RES 2017. [DOI: 10.3354/esr00792] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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20
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Butler MJ, Crimmin MR. Magnesium, zinc, aluminium and gallium hydride complexes of the transition metals. Chem Commun (Camb) 2017; 53:1348-1365. [PMID: 28070586 PMCID: PMC5777540 DOI: 10.1039/c6cc05702k] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Accepted: 12/23/2016] [Indexed: 12/21/2022]
Abstract
The preparation and applications of heterobimetallic complexes continue to occupy researchers in the fields of organometallic, main group, and coordination chemistry. This interest stems from the promise these complexes hold as precursors to materials, reagents in synthesis and as new catalysis. Here we survey and organise the state-of-the-art understanding of the TM-H-M linkage (M = Mg, Zn, Al, Ga). We discuss the structure and bonding in these complexes, their known reactivity, and their largely unrealised potential in catalysis.
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Affiliation(s)
- Michael J Butler
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK.
| | - Mark R Crimmin
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK.
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21
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Affiliation(s)
| | | | - Alan W. Day
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 Canada
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22
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Butler MJ, Crowe JA, Hayes-Gill BR, Rodmell PI. Motion limitations of non-contact photoplethysmography due to the optical and topological properties of skin. Physiol Meas 2016; 37:N27-37. [DOI: 10.1088/0967-3334/37/5/n27] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Butler MJ, White AJP, Crimmin MR. Isomerization of Cyclooctadiene to Cyclooctyne with a Zinc/Zirconium Heterobimetallic Complex. Angew Chem Int Ed Engl 2016; 55:6951-3. [PMID: 27071992 PMCID: PMC5074263 DOI: 10.1002/anie.201601758] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [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: 02/19/2016] [Indexed: 11/23/2022]
Abstract
Reaction of a zinc/zirconium heterobimetallic complex with 1,5‐cyclooctadiene (1,5‐COD) results in slow isomerization to 1,3‐cyclooctadiene (1,3‐COD), along with the formation of a new complex that includes a cyclooctyne ligand bridging two metal centers. While analogous magnesium/zirconium and aluminum/zirconium heterobimetallic complexes are competent for the catalytic isomerization of 1,5‐COD to 1,3‐COD, only in the case of the zinc species is the cyclooctyne adduct observed.
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Affiliation(s)
- Michael J Butler
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Andrew J P White
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK
| | - Mark R Crimmin
- Department of Chemistry, Imperial College London, South Kensington, London, SW7 2AZ, UK.
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24
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Affiliation(s)
- Michael J. Butler
- Department of Chemistry; Imperial College London; South Kensington London SW7 2AZ UK
| | - Andrew J. P. White
- Department of Chemistry; Imperial College London; South Kensington London SW7 2AZ UK
| | - Mark R. Crimmin
- Department of Chemistry; Imperial College London; South Kensington London SW7 2AZ UK
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25
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Smith AS, Tabbaa M, Lei K, Eastham P, Butler MJ, Linton L, Altshuler R, Liu Y, Wang Z. Local oxytocin tempers anxiety by activating GABAA receptors in the hypothalamic paraventricular nucleus. Psychoneuroendocrinology 2016; 63:50-8. [PMID: 26415118 PMCID: PMC4695278 DOI: 10.1016/j.psyneuen.2015.09.017] [Citation(s) in RCA: 72] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 09/17/2015] [Accepted: 09/17/2015] [Indexed: 12/21/2022]
Abstract
Oxytocin (Oxt) is released in various hypothalamic and extrahypothalamic brain areas in response to anxiogenic stimuli to regulate aspects of emotionality and stress coping. We examined the anxiolytic action of Oxt in the hypothalamic paraventricular nucleus (PVN) while appraising if Oxt recruits GABA neurons to inhibit the behavioral, hormonal, and neuronal response to stress in female prairie voles (Microtus ochrogaster). Voles received an injection of Oxt in the PVN either before or after an elevated platform stress to determine a time-course for the effects of Oxt on the hormonal stress response. Subsequently, we evaluated if ante-stress injections of Oxt affected anxiety-like behaviors as well as neuronal activity in the PVN, using real-time in-vivo retrodialysis and immunohistochemistry with c-Fos expression as a biomarker of neural activity. In addition, we exposed voles to Oxt and a GABAA receptor antagonist, concurrently, to evaluate the impact of pharmacological blockade of GABAA receptors on the anxiolytic effects of Oxt. Elevated platform stress amplified anxiety-like behaviors and hypothalamic-pituitary-adrenal (HPA) axis activity-catalyzing corticotrophin-releasing hormone (CRH) neuronal activity and augmenting corticosterone release in circulation. Ante-stress Oxt injections in the PVN blocked these stress effects while promoting PVN GABA activity and release. Post-stress Oxt treatments were ineffective. The anxiolytic effects of Oxt were hindered by concurrent pharmacological blockade of GABAA receptors. Together, our data demonstrate ante-stress treatments of Oxt in the PVN inhibit stress activation of the HPA axis through recruitment of GABAergic neurons, providing insights to the local circuitry and potential therapeutically-relevant mechanisms.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Zuoxin Wang
- Department of Psychology and Program in Neuroscience, Florida State University, Tallahassee, FL 32306, USA.
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Abstract
Addition of fluoroarenes, fluoroalkanes or benzofuran to [{(2,6-iPr2C6H3NCMe)2CH}Al] results in facile oxidative addition of either a C–F or C–O bond to the Al(i) centre.
Addition of fluoroarenes, fluoroalkanes or benzofuran to [{(2,6-iPr2C6H3NCMe)2CH}Al] results in facile oxidative addition of either a C–F or C–O bond to the Al(i) centre.
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Affiliation(s)
- Mark R Crimmin
- Department of Chemistry, Imperial College London, South Kensington, London SW7 2AZ, UK.
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Ryu YG, Butler MJ, Chater KF, Lee KJ. Engineering of primary carbohydrate metabolism for increased production of actinorhodin in Streptomyces coelicolor. Appl Environ Microbiol 2006; 72:7132-9. [PMID: 16950896 PMCID: PMC1636169 DOI: 10.1128/aem.01308-06] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [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: 06/08/2006] [Accepted: 08/28/2006] [Indexed: 11/20/2022] Open
Abstract
The objectives of the current studies were to determine the roles of key enzymes in central carbon metabolism in the context of increased production of antibiotics in Streptomyces coelicolor. Genes for glucose-6-phosphate dehydrogenase and phosphoglucomutase (Pgm) were deleted and those for the acetyl coenzyme A carboxylase (ACCase) were overexpressed. Under the conditions tested, glucose-6-phosphate dehydrogenase encoded by zwf2 plays a more important role than that encoded by zwf1 in determining the carbon flux to actinorhodin (Act), while the function of Pgm encoded by SCO7443 is not clearly understood. The pgm-deleted mutant unexpectedly produced abundant glycogen but was impaired in Act production, the exact reverse of what had been anticipated. Overexpression of the ACCase resulted in more rapid utilization of glucose and sharply increased the efficiency of its conversion to Act. From the current experiments, it is concluded that carbon storage metabolism plays a significant role in precursor supply for Act production and that manipulation of central carbohydrate metabolism can lead to an increased production of Act in S. coelicolor.
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Affiliation(s)
- Yong-Gu Ryu
- School of Biological Sciences, Seoul National University, Seoul 151-747, Republic of Korea
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Bushell ME, Sequeira SI, Khannapho C, Zhao H, Chater KF, Butler MJ, Kierzek AM, Avignone-Rossa CA. The use of genome scale metabolic flux variability analysis for process feed formulation based on an investigation of the effects of the zwf mutation on antibiotic production in Streptomyces coelicolor. Enzyme Microb Technol 2006. [DOI: 10.1016/j.enzmictec.2006.06.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Rangel DEN, Butler MJ, Torabinejad J, Anderson AJ, Braga GUL, Day AW, Roberts DW. Mutants and isolates of Metarhizium anisopliae are diverse in their relationships between conidial pigmentation and stress tolerance. J Invertebr Pathol 2006; 93:170-82. [PMID: 16934287 DOI: 10.1016/j.jip.2006.06.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [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: 03/10/2006] [Revised: 06/21/2006] [Accepted: 06/24/2006] [Indexed: 11/27/2022]
Abstract
Conidial pigmentation is involved in protection against heat and UV radiation in several fungal species. In this study, we compare the tolerance of 17 color mutants of wild-type ARSEF 23 plus 13 color mutants of wild-type ARSEF 2575 of Metarhizium anisopliae var. anisopliae to wet-heat and UV-B or simulated-solar radiation. The stress tolerance of each mutant was compared with that of its wild-type parent, and with the most thermo- and UV-tolerant wild-type Metarhizium we have tested to date, M. anisopliae var. acridum (ARSEF 324). The color of each isolate or mutant was identified with the PANTONE Color Standard book [Eiseman, L., Herbert, L., 1990. The PANTONE((R)) Book of Color: over 1000 color standards: color basics and guidelines for design, fashion, furnishing... and more. Harry N. Abrams, Inc., Publishers, New York]. In addition, the pigments of each mutant or wild-type were extracted and the UV absorbances of the extracts compared to the stress tolerance of those isolates; but no relationships were detected. Color mutants of ARSEF 23, in general, were less UV tolerant than their parent wild-type. With ARSEF 23 and its mutants, conidial pigmentation was important to conidial tolerance to UV-B and simulated-solar radiation; but color had less impact on ARSEF 2575 and its mutants. The ARSEF 2575 color mutants were less variable in UV tolerance than those of ARSEF 23, even though very similar colors occurred in the two groups of mutants. When color mutants of ARSEF 23 reverted to wild-type color they recovered wild-type levels of UV tolerance. Results of UV-B and UV-A exposures of wild-types ARSEF 23 and ARSEF 2575 conidia indicated that they are equally tolerant of UV-A, but differ in UV-B-response. For thermotolerance, several mutants were more heat tolerant than their wild-type parents. Accordingly, darker pigmentation of wild-type isolates was not important to protection against heat.
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Abstract
Silver-staining procedures were investigated for their effectiveness in identifying cell wall-based fungal melanins in live and fixed plastic embedded samples, particularly 1,8-dihydroxynaphthalene (DHN) based polyketide melanins. We developed a simple and reliable melanin-staining technique based on a silver accumulation method originally published for histological demonstration of heavy metal sulfides in mammalian tissues. Copper is bound to fungal melanin followed by formation of the copper sulfide at melanin sites in fungal cell walls, which then are amplified into vivid black stains using a silver enhancement step. The method demonstrates patterns of melanization in a range of fungal hyphae and is suitable for light and electron microscopy. Albino mutant fungi and normally nonmelanized fungi do not stain with the sulfide-silver technique. Mammalian melanocytes also were labeled by the technique, indicating its universality as a melanin probe.
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Affiliation(s)
- M J Butler
- Department of Biology, University of Western Ontario, London, Ontario, N6A 5B7 Canada.
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Butler MJ, Takano E, Bruheim P, Jovetic S, Marinelli F, Bibb MJ. Deletion of scbA enhances antibiotic production in Streptomyces lividans. Appl Microbiol Biotechnol 2003; 61:512-6. [PMID: 12764566 DOI: 10.1007/s00253-003-1277-8] [Citation(s) in RCA: 18] [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] [Received: 11/07/2002] [Revised: 01/10/2003] [Accepted: 01/24/2003] [Indexed: 10/25/2022]
Abstract
Antibiotic production in many streptomycetes is influenced by extracellular gamma-butyrolactone signalling molecules. In this study, the gene scbA, which had been shown previously to be involved in the synthesis of the gamma-butyrolactone SCB1 in Streptomyces coelicolor A3(2), was deleted from the chromosome of Streptomyces lividans 66. Deletion of scbA eliminated the production of the antibiotic stimulatory activity previously associated with SCB1 in S. coelicolor. When the S. lividans scbA mutant was transformed with a multi-copy plasmid carrying the gene encoding the pathway-specific activator for either actinorhodin or undecylprodigiosin biosynthesis, production of the corresponding antibiotic was elevated significantly compared to the corresponding scbA(+) strain carrying the same plasmid. Consequently, deletion of scbA may be useful in combination with other strategies to construct host strains capable of improved bioactive metabolite production.
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Affiliation(s)
- M J Butler
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK.
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Butler MJ, Bruheim P, Jovetic S, Marinelli F, Postma PW, Bibb MJ. Engineering of primary carbon metabolism for improved antibiotic production in Streptomyces lividans. Appl Environ Microbiol 2002; 68:4731-9. [PMID: 12324314 PMCID: PMC126421 DOI: 10.1128/aem.68.10.4731-4739.2002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.0] [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: 03/29/2002] [Accepted: 07/11/2002] [Indexed: 11/20/2022] Open
Abstract
Deletions were made in Streptomyces lividans in either of two genes (zwf1 and zwf2) encoding isozymes of glucose-6-phosphate dehydrogenase, the first enzyme in the oxidative pentose phosphate pathway (PPP). Each mutation reduced the level of Zwf activity to approximately one-half that observed in the wild-type strain. When the mutants were transformed with multicopy plasmids carrying the pathway-specific transcriptional activator genes for either the actinorhodin (ACT) or undecylprodigiosin (RED) biosynthetic pathway, they produced higher levels of antibiotic than the corresponding wild-type control strains. The presumed lower flux of carbon through the PPP in each of the Deltazwf mutants may allow more efficient glucose utilization via glycolysis, resulting in higher levels of antibiotic production. This appears to occur without lowering the concentration of NADPH (the major biochemical product of the oxidative PPP activity) to a level that would limit antibiotic biosynthesis. Consistent with this hypothesis, deletion of the gene (devB) encoding the enzyme that catalyzes the next step in the oxidative PPP (6-phosphogluconolactonase) also resulted in increased antibiotic production. However, deletion of both zwf genes from the devB mutant resulted in reduced levels of ACT and RED production, suggesting that some of the NADPH made by the PPP is utilized, directly or indirectly, for antibiotic biosynthesis. Although applied here to the model antibiotics ACT and RED, such mutations may prove to be useful for improving the yield of commercially important secondary metabolites.
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Affiliation(s)
- Michael J Butler
- Department of Molecular Microbiology, John Innes Centre, Norwich, NR4 7UH, United Kingdom.
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Butler MJ, d'Ortho MP, Atkinson SJ. Expression of recombinant membrane-type MMPs. Methods Mol Biol 2001; 151:239-55. [PMID: 11217302 DOI: 10.1385/1-59259-046-2:239] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Affiliation(s)
- M J Butler
- Department of Genetics, John Innes Centre, Norwich Research Park, Colney, Norwich, UK
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Atkinson SJ, Patterson ML, Butler MJ, Murphy G. Membrane type 1 matrix metalloproteinase and gelatinase A synergistically degrade type 1 collagen in a cell model. FEBS Lett 2001; 491:222-6. [PMID: 11240131 DOI: 10.1016/s0014-5793(01)02204-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A fibrosarcoma cell line transfected with the matrix metalloproteinase MT1 MMP showed an enhanced ability to degrade 14C-labelled collagen films. As previously shown for proMMP 2 activation, TIMP 1 was an ineffective inhibitor of the process of collagenolysis whereas TIMP 2 was efficient and completely prevented collagen degradation. In the presence of the calcium ionophore, ionomycin, proteolytic processing of MT1 MMP was restricted and collagenolysis did not occur indicating that the 63 kDa form of the enzyme is not a functional collagenase. The collagenolytic activity of MT1 MMP was shown to be enhanced by the addition of proMMP 2, but TIMP 1 inhibition remained poor relative to that of TIMP 2. The study demonstrated that synergy between two non-conventional collagenases effectively degrades insoluble pericellular collagen. Due to the membrane localisation of MT1 MMP, this could potentially occur in a highly localised manner.
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Affiliation(s)
- S J Atkinson
- School of Biological Sciences, University of East Anglia, NR4 7TJ, Norwich, UK
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Abstract
Interferon-alpha (IFN-alpha) was among the first cytokines studied and the earliest to be used in clinical medicine for the treatment of viral infections and malignancies. Although the capacity of IFN-alpha to augment NK cell cytotoxicity against virus-infected target cells or tumor cells is well established, the mechanism has not been fully elucidated. Here we report that IFN-alpha stimulation of PBMC from healthy donors induces Fas (CD95) ligand (FasL) transcription and leads to increased cell surface FasL expression exclusively on the NK cell fraction. Furthermore, IFN-alpha augments the FasL-mediated cytotoxicity of normal PBMC against Fas-sensitive lymphoid tumor cells. In the context of innate immunity, induction of FasL by IFN-alpha can be viewed as an efficient mechanism to potentiate NK cell cytotoxicity in the presence of harmful targets, such as virally infected or transformed cells.
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Affiliation(s)
- K A Kirou
- Department of Medicine, Hospital for Special Surgery and Weill Medical College of Cornell University, New York, New York 10021, USA
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Abstract
A ptsH homologue of Streptomyces coelicolor A3(2) was identified in the emerging genome sequence, cloned in Escherichia coli and the S. coelicolor HPr over-produced and purified. The protein was phosphorylated in vitro in a phosphoenolpyruvate (PEP)-dependent manner by purified enzyme I (EI) from Bacillus subtilis, and much less efficiently in an ATP-dependent manner by purified HPr kinase, also from B. subtilis. There was no indication of ATP-dependent phosphorylation of the purified protein by cell extracts of either S. coelicolor or Streptomyces lividans. Deletion of the ptsH homologue from the S. coelicolor and S. lividans chromosomes had no effect on growth when fructose was supplied as sole carbon source, and in S. coelicolor it had no effect on glucose repression of agarase and galactokinase synthesis, suggesting that the HPr encoded by this gene does not play an essential role in fructose transport nor a general role in carbon catabolite repression.
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Affiliation(s)
- M J Butler
- Department of Genetics, John Innes Centre, Colney, Norwich, UK
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Abstract
Melanins are darkly pigmented polymers that protect organisms against environmental stress. Even when not directly involved in pathogenesis, fungal melanin is likely required by melanizing phytopathogens for survival in the environment. However, some phytopathogenic fungi that produce melanized appressoria for host invasion require appressorial melanogenesis for pathogenicity. Much less is known about the role melanins play in pathogenesis during infection by other phytopathogens that do not rely on appressoria for host penetration. Here we focus on one such phytopathogenic fungus, Gaeumannomyces graminis var. tritici, the etiologic agent of the devastating root disease of cereals, take-all. This fungus is lightly pigmented in culture, but requires melanin biosynthesis for pathogenesis, perhaps to produce melanized, ectotrophic macrohyphae on roots. However, the constitutively melanized, asexual Phialophora anamorph of G. graminis var. tritici is nonpathogenic. In addition, melanization of G. graminis var. graminis is not required to produce root disease on its rice host. Explanations for these apparent contradictions are suggested, as are other functions for the melanins of phytopathogenic fungi.
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Affiliation(s)
- Joan M Henson
- Department of Microbiology, Montana State University, Bozeman, Montana 59717;
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Abstract
The relationship of polyketide melanogenesis molecular biology to that of nonmelanin-producing pathways in a wide range of fungi and other organisms is discussed. Analytical methods and fundamental properties of melanins are discussed and fungal melanin properties are compared with those of animal and bacterial melanins. The enzymatic degradation of melanins by lignin peroxidases is described.Key words: fungal melanin, polyketide melanin, DHN melanin, melanin degradation, melanin properties, melanin analysis.
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Butler GS, Butler MJ, Atkinson SJ, Will H, Tamura T, Schade van Westrum S, Crabbe T, Clements J, d'Ortho MP, Murphy G. The TIMP2 membrane type 1 metalloproteinase "receptor" regulates the concentration and efficient activation of progelatinase A. A kinetic study. J Biol Chem 1998; 273:871-80. [PMID: 9422744 DOI: 10.1074/jbc.273.2.871] [Citation(s) in RCA: 441] [Impact Index Per Article: 17.0] [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: 02/05/2023] Open
Abstract
We have used C-terminal domain mutants to further define the role of interactions of progelatinase A and membrane type 1 matrix metalloproteinase (MT1 MMP) in the binding of TIMP2 and in the cell-associated activation of progelatinase A. Soluble constructs of MT1 MMP were used to demonstrate that binding with TIMP2 occurs primarily through N-terminal domain interactions, leaving the C-terminal domain free for interactions with progelatinase A. The rate of autolytic activation of progelatinase A initiated by MT1 MMP cleavage could be potentiated by concentration of the proenzyme by binding to heparin. Residues 568-631 of the progelatinase A C-terminal domain are important in formation of the heparin binding site, since replacement of this region with the corresponding stromelysin-1 sequence abolished binding to heparin and the potentiation of activation. The same region of gelatinase A was required for binding of latent and active enzyme to TIMP2, but residues 418-474 were not important. A similar pattern was seen using cell membrane-associated MT1 MMP; residues 568-631 were required for binding and activation of progelatinase A, whereas residues 418-474 were not. Neither region was required for activation in solution. The addition of TIMP2 to HT1080 membrane preparations expressing MT1 MMP, but depleted of endogenous TIMP2, resulted in potentiation of progelatinase A activation. This effect was dependent upon TIMP2 binding to MT1 MMP rather than at an independent membrane site. Together, the data suggest that TIMP2 forms a receptor with MT1 MMP that regulates the concentration and efficient generation of functionally active gelatinase A.
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Affiliation(s)
- G S Butler
- Strangeways Research Laboratory, Worts' Causeway, Cambridge CB1 4RN and School of Biological Sciences, University of East Anglia, Norwich NR4 7TJ, United Kingdom
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Butler MJ, Aphale JS, Binnie C, DiZonno MA, Krygsman P, Soltes G, Walczyk E, Malek LT. Cloning and analysis of a gene from Streptomyces lividans 66 encoding a novel secreted protease exhibiting homology to subtilisin BPN'. Appl Microbiol Biotechnol 1996; 45:141-7. [PMID: 8920189 DOI: 10.1007/s002530050662] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Amino-terminal degradation has been observed for many of the secreted heterologous proteins produced by S. lividans 66. We, therefore, set out to characterize the relevant proteinases and their genes. A tripeptide chromogenic substrate was used to identify a gene that was shown to encode a secreted protein which removed tripeptides from the amino terminus of extracellular proteins (tripeptidyl aminopeptidase, Tap; Butler et al. 1995). This activity was removed by a homologous gene deletion replacement and the ability of the S. lividans strain to remove N-terminal tripeptides was greatly reduced, but still significant. When the tap-deleted strain was used as a host for the rescreening of a S. lividans 66 genomic DNA library, a number of other genes encoding proteases with aminopeptidase activities were discovered. One clone (P5-4) produced a 45-kDa secreted protein (Ssp), which showed activity against Ala-Pro-Ala-beta-naphthylamide (APA-beta NH-Nap) substrate. Further analysis of the cloned DNA showed an open-reading frame encoding a protein larger than 45 kDa. Direct Edman degradation of the secreted protein confirmed that it was encoded within the cloned DNA and probably processed from a larger precursor. Protein sequence analysis revealed a striking homology to subtilisin BPN' in three regions around the active-site residues suggesting that the protein is a serine protease. As expected, the protease activity was inhibited by phenylmethylsulphonyl fluoride. Mutant strains with most of the ssp gene deleted exhibited reduced activity against APA-beta NH-Nap substrate compared to their non-deleted parental strains.
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Affiliation(s)
- M J Butler
- Cangene Corporation, Mississauga, Ontario, Canada
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Atkinson SJ, Crabbe T, Cowell S, Ward RV, Butler MJ, Sato H, Seiki M, Reynolds JJ, Murphy G. Intermolecular autolytic cleavage can contribute to the activation of progelatinase A by cell membranes. J Biol Chem 1995; 270:30479-85. [PMID: 8530478 DOI: 10.1074/jbc.270.51.30479] [Citation(s) in RCA: 187] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Membrane-type matrix metalloproteinase (MT-MMP) messenger RNA and protein expression were shown to be elevated in human fibroblasts following treatment with concanavalin A, coincident with the induction of the ability to process progelatinase A. CHO cells transfected with the cDNA for MT-MMP were able to process both wild type progelatinase A and a catalytically inactive mutant, E375A progelatinase A. Both proenzymes were converted to a 68-kDa intermediate (reducing gels) form, but only the wild type enzyme was processed further to a 66-kDa end product. In contrast, both forms of progelatinase were processed via the 68-kDa intermediate to 66 kDa by concanavalin A-stimulated fibroblasts. Further study of the processing of E375A progelatinase A by plasma membrane preparations from concanavalin A-stimulated fibroblasts showed that addition of active gelatinase A enhanced processing to the mature form. It was concluded that cell membrane-mediated activation of progelatinase A could be via a cascade involving both MT-MMP and intermolecular autolytic cleavage.
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Affiliation(s)
- S J Atkinson
- Department of Cell and Molecular Biology, Strangeways Research Laboratory, Cambridge, United Kingdom
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Binnie C, Butler MJ, Aphale JS, Bourgault R, DiZonno MA, Krygsman P, Liao L, Walczyk E, Malek LT. Isolation and characterization of two genes encoding proteases associated with the mycelium of Streptomyces lividans 66. J Bacteriol 1995; 177:6033-40. [PMID: 7592364 PMCID: PMC177439 DOI: 10.1128/jb.177.21.6033-6040.1995] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [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] Open
Abstract
A strain of Streptomyces lividans 66 deleted for a major tripeptidyl aminopeptidase (Tap) was used as a host to screen an S. lividans genomic library for clones overexpressing activity against the chromogenic substrate Ala-Pro-Ala-beta-naphthylamide. In addition to reisolation of the tap gene, clones representing another locus, slpD, were uncovered. slpD was analyzed by deletion subcloning to localize its functional sequence. Nucleotide sequence determination revealed an open reading frame encoding a 55-kDa protein exhibiting significant amino acid sequence homology to Tap, particularly around the putative active-site serine residue. No secreted protein was observed for strains harboring the slpD clone, but inspection of the predicted protein sequence revealed a putative lipoprotein signal peptide (signal peptidase II type), suggesting a mycelial location for the SlpD proteinase. In an attempt to isolate an endoprotease known to be active against some heterologous proteins, a second clone was isolated by using a longer substrate (t-butyloxycarbonyl [Boc]-APARSPA-beta-naphthylamide) containing a chemical blocking group at the amino terminus to prevent aminopeptidase cleavage. This locus, slpE, appeared to also encode a 55-kDa mycelium-associated (lipoprotein) proteinase, whose predicted protein sequences showed significant amino acid homology to Tap and SlpD, particularly around the putative active-site serine residues. Chromosomal integration and deletion analysis in both the wild-type and Tap-deficient backgrounds appeared to indicate that SlpD was essential for viability and SlpE was required for growth on minimal media.
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Affiliation(s)
- C Binnie
- Cangene Corporation, Mississauga, Canada
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Butler MJ, Binnie C, DiZonno MA, Krygsman P, Soltes GA, Soostmeyer G, Walczyk E, Malek LT. Cloning and characterization of a gene encoding a secreted tripeptidyl aminopeptidase from Streptomyces lividans 66. Appl Environ Microbiol 1995; 61:3145-50. [PMID: 7487044 PMCID: PMC167588 DOI: 10.1128/aem.61.8.3145-3150.1995] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [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: 01/25/2023] Open
Abstract
The gene encoding a tripeptidyl aminopeptidase (Tap) from Streptomyces lividans was cloned by using a simple agar plate activity assay. Overexpression of the cloned gene results in the production of a secreted protein which has an apparent subunit molecular weight of 55,000 and is responsible for the major amino-terminal degradative activity in culture broths of S. lividans strains. A DNA sequence analysis revealed a potential protein-encoding region of the size expected to encode the observed protein, which contained a sequence that exhibited significant homology around a putative active site serine residue observed for lipases, esterases, and acyl transferases. Preceding the amino terminus of the secreted protein was a predicted signal peptide of 36 amino acids followed by a tripeptide, which could be autocatalytically removed from a secreted Tap precursor. The transcriptional start site for the gene was mapped by primer extension. Mutant strains of S. lividans lacking detectable Tap activity were able to grow and sporulate normally. Cross-species hybridization experiments showed that DNA homologs of the tap gene are present in most of the Streptomyces strains tested.
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Affiliation(s)
- M J Butler
- Cangene Corporation, Mississauga, Ontario, Canada
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Abstract
Recent epidemiologic studies have implicated red meat consumption as a risk factor for colon cancer in both men and women. However, it has been very difficult to separate the effects of meat as a protein source from the accompanying fat content of the diets analyzed in these studies. Experimental data from rodent feeding trials show mixed results, with no firm conclusions being possible in terms of the colon-cancer promoting effects of meat fat. The goal of the present study was to compare, in an experimental animal model, the effects of beef with casein as a protein source, within the context of a low- and high-fat diet containing either corn oil or beef tallow, on promotion of colon carcinogenesis. Tumors were induced in Sprague-Dawley rats with 1,2-dimethylhydrazine (20 mg/kg body wt for 10 weeks). Two hundred and eighty male weanling rats were randomized to eight dietary treatment groups of a 2x2x2 factorial design with fat source (corn oil vs. beef tallow), fat level (5% vs. 20%), and protein source (very lean beef vs. casein) as the factors. Diets were fed ad libitum before, during and after carcinogen treatment for a total of 27 weeks. At termination of the study, animals were examined for location, size and type of colon or extracolonic lesions. The total incidence and number of colon tumors were significantly lower in the groups fed beef rather than casein. High fat levels, regardless of source, significantly increased the number of colon adenomas. These results demonstrate that when lean beef is used as the protein source in the context of a low-fat diet, fewer intestinal tumors develop. These data do not support the belief that red meat consumption increases the risk for colon carcinogenesis, but underscores the importance of fat level in dietary context.
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Affiliation(s)
- B C Pence
- Department of Pathology, Texas Tech University Health Sciences Center, Lubbock, USA
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Abstract
This manuscript describes female partner abuse and reviews its significance to health care providers. Attention is given to the essential nursing roles of screening for abuse, intervening with women at risk for abuse, and completing a needed examination when abuse has occurred. Ideas for an expanded nursing role are provided.
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Abstract
The gene (pepN) encoding an aminopeptidase N (PepN) has been cloned from Streptomyces lividans. This was done using either leucine-beta-naphthylamide or arginine-beta-naphthylamide in a liquid overlayer on colonies growing on agar medium to screen for overproduction of the ability to hydrolyse the substrates. The nucleotide sequence of pepN was determined and shown to encode a 95-kDa protein, which displayed significant homology to PepN proteins from other organisms. Analysis of the overproduced proteinase confirmed that this protein was located intracellularly as a monomeric active species. PepN is a metallo-exopeptidase cleaving next to Leu, Arg and Lys in peptide-bond-containing substrates.
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Affiliation(s)
- M J Butler
- Cangene Corporation, Mississauga, Ontario, Canada
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Abstract
The complete nucleotide sequences of the Streptomyces rimosus oxytetracycline (oxyTc) polyketide synthase (PKS)-encoding genes (otcY) has been determined, revealing three open reading frames. The deduced amino-acid sequences correspond to the presumed heterodimeric beta-ketoacyl synthase and acyl carrier protein found in other type-II (multicomponent) PKS systems that specify construction of acetate-derived polyketide antibiotics.
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Affiliation(s)
- E S Kim
- Department of Microbiology, University of Minnesota, St. Paul 55108
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Butler MJ, Aphale JS, DiZonno MA, Krygsman P, Walczyk E, Malek LT. Intracellular aminopeptidases in Streptomyces lividans 66. J Ind Microbiol 1994; 13:24-9. [PMID: 7765336 DOI: 10.1007/bf01569658] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have investigated the aminopeptidase activities present in Streptomyces lividans strains. The majority of these activities proved to be intracellular with multiple active species. Two aminopeptidase P genes were identified to be responsible for the ability to hydrolyze amino terminal peptide bonds adjacent to proline residues. Two other broad spectrum aminopeptidases were found to display homology at both the DNA and protein levels. One showed significant homology to PepN proteins, particularly around the putative zinc-binding residues which are important for catalysis. The second broad spectrum activity was not analyzed in detail but showed a different spectrum of substrate specificity to that of PepN.
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Affiliation(s)
- M J Butler
- Cangene Corporation, Mississauga, Ontario, Canada
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50
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Abstract
An aminopeptidase P (PepP)-encoding gene has been cloned from Streptomyces lividans 66 by screening for overexpression of activity using the chromogenic substrate Gly-Pro-beta-naphthylamide as a liquid overlayer on colonies growing on agar medium. The pepP gene was localised by deletion mapping, and the nucleotide sequence was determined. The deduced amino acid sequence was found to display significant similarity to Escherichia coli PepP. The partially purified S. lividans enzyme had a 50-kDa subunit and was present as a homodimer. Direct Edman degradation of the purified protein confirmed that pepP encoded the observed intracellular PepP.
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Affiliation(s)
- M J Butler
- Cangene Corporation, Mississauga, Ontario, Canada
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