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Valentine Y, Nikolajczyk BS. T cells in obesity-associated inflammation: The devil is in the details. Immunol Rev 2024. [PMID: 38767210 DOI: 10.1111/imr.13354] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
Obesity presents a significant health challenge, affecting 41% of adults and 19.7% of children in the United States. One of the associated health challenges of obesity is chronic low-grade inflammation. In both mice and humans, T cells in circulation and in the adipose tissue play a pivotal role in obesity-associated inflammation. Changes in the numbers and frequency of specific CD4+ Th subsets and their contribution to inflammation through cytokine production indicate declining metabolic health, that is, insulin resistance and T2D. While some Th subset alterations are consistent between mice and humans with obesity, some changes mainly characterize male mice, whereas female mice often resist obesity and inflammation. However, protection from obesity and inflammation is not observed in human females, who can develop obesity-related T-cell inflammation akin to males. The decline in female sex hormones after menopause is also implicated in promoting obesity and inflammation. Age is a second underappreciated factor for defining and regulating obesity-associated inflammation toward translating basic science findings to the clinic. Weight loss in mice and humans, in parallel with these other factors, does not resolve obesity-associated inflammation. Instead, inflammation persists amid modest changes in CD4+ T cell frequencies, highlighting the need for further research into resolving changes in T-cell function after weight loss. How lingering inflammation after weight loss affecting the common struggle to maintain lower weight is unknown. Semaglutide, a newly popular pharmaceutical used for treating T2D and reversing obesity, holds promise for alleviating obesity-associated health complications, yet its impact on T-cell-mediated inflammation remains unexplored. Further work in this area could significantly contribute to the scientific understanding of the impacts of weight loss and sex/hormones in obesity and obesity-associated metabolic decline.
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Affiliation(s)
- Yolander Valentine
- Department of Pharmacology and Nutritional Science, University of Kentucky, Lexington, Kentucky, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Science, University of Kentucky, Lexington, Kentucky, USA
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, Kentucky, USA
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, Kentucky, USA
- Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, Kentucky, USA
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2
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Rockhold JD, Marszalkowski H, Sannella M, Gibney K, Murphy L, Zukowski E, Kalantar GH, SantaCruz-Calvo S, Hart SN, Kuhn MK, Yu J, Stefanik O, Chase G, Proctor EA, Hasturk H, Nikolajczyk BS, Bharath LP. Everolimus alleviates CD4 + T cell inflammation by regulating autophagy and cellular redox homeostasis. GeroScience 2024:10.1007/s11357-024-01187-z. [PMID: 38761287 DOI: 10.1007/s11357-024-01187-z] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Accepted: 04/30/2024] [Indexed: 05/20/2024] Open
Abstract
Aging is associated with the onset and progression of multiple diseases, which limit health span. Chronic low-grade inflammation in the absence of overt infection is considered the simmering source that triggers age-associated diseases. Failure of many cellular processes during aging is mechanistically linked to inflammation; however, the overall decline in the cellular homeostasis mechanism of autophagy has emerged as one of the top and significant inducers of inflammation during aging, frequently known as inflammaging. Thus, physiological or pharmacological interventions aimed at improving autophagy are considered geroprotective. Rapamycin analogs (rapalogs) are known for their ability to inhibit mTOR and thus regulate autophagy. This study assessed the efficacy of everolimus, a rapalog, in regulating inflammatory cytokine production in T cells from older adults. CD4+ T cells from older adults were treated with a physiological dose of everolimus (0.01 µM), and indices of autophagy and inflammation were assessed to gain a mechanistic understanding of the effect of everolimus on inflammation. Everolimus (Ever) upregulated autophagy and broadly alleviated inflammatory cytokines produced by multiple T cell subsets. Everolimus's ability to alleviate the cytokines produced by Th17 subsets of T cells, such as IL-17A and IL-17F, was dependent on autophagy and antioxidant signaling pathways. Repurposing the antineoplastic drug everolimus for curbing inflammaging is promising, given the drug's ability to restore multiple cellular homeostasis mechanisms.
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Affiliation(s)
- Jack Donato Rockhold
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA
| | | | - Marco Sannella
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA
| | - Kaleigh Gibney
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA
| | - Lyanne Murphy
- Department of Biology, Merrimack College, North Andover, MA, USA
| | - Emelia Zukowski
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA
| | - Gabriella H Kalantar
- Dept of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Sara SantaCruz-Calvo
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
| | - Samantha N Hart
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
- Department of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY, USA
| | - Madison K Kuhn
- Department of Neurosurgery, Pharmacology, and Biomedical Engineering and Center for Neural Engineering, Pennsylvania State University, Hershey, PA, USA
| | - Jingting Yu
- Razavi Newman Integrative Genomics and Bioinformatics Core, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Olivia Stefanik
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA
| | - Gabrielle Chase
- Department of Chemistry and Biochemistry, Merrimack College, North Andover, MA, USA
| | - Elizabeth A Proctor
- Department of Neurosurgery, Pharmacology, and Biomedical Engineering and Center for Neural Engineering, Pennsylvania State University, Hershey, PA, USA
- Department of Engineering Science & Mechanics, Pennsylvania State University, University Park, PA, USA
| | | | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
| | - Leena P Bharath
- Department of Health Sciences and Nutrition, Merrimack College, North Andover, MA, USA.
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Winford E, Lutshumba J, Martin BJ, Wilcock DM, Jicha GA, Nikolajczyk BS, Stowe AM, Bachstetter AD. Terminally differentiated effector memory T cells associate with cognitive and AD-related biomarkers in an aging-based community cohort. bioRxiv 2023:2023.11.27.568812. [PMID: 38077088 PMCID: PMC10705256 DOI: 10.1101/2023.11.27.568812] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/24/2023]
Abstract
Background and Purpose The immune response changes during aging and the progression of Alzheimer's disease (AD) and related dementia (ADRD). Terminally differentiated effector memory T cells (called TEMRA) are important during aging and AD due to their cytotoxic phenotype and association with cognitive decline. However, it is not clear if the changes seen in TEMRAs are specific to AD-related cognitive decline specifically or are more generally correlated with cognitive decline. This study aimed to examine whether TEMRAs are associated with cognition and plasma biomarkers of AD, neurodegeneration, and neuroinflammation in a community-based cohort of older adults. Methods Study participants from a University of Kentucky Alzheimer's Disease Research Center (UK-ADRC) community-based cohort of aging and dementia were used to test our hypothesis. There were 84 participants, 44 women and 40 men. Participants underwent physical examination, neurological examination, medical history, cognitive testing, and blood collection to determine plasma biomarker levels (Aβ42/Aβ40 ratio, total tau, Neurofilament Light chain (Nf-L), Glial Fibrillary Acidic Protein (GFAP)) and to isolate peripheral blood mononuclear cells (PBMCs). Flow cytometry was used to analyze PBMCs from study participants for effector and memory T cell populations, including CD4+ and CD8+ central memory T cells (TCM), Naïve T cells, effector memory T cells (TEM), and effector memory CD45RA+ T cells (TEMRA) immune cell markers. Results CD8+ TEMRAs were positively correlated with Nf-L and GFAP. We found no significant difference in CD8+ TEMRAs based on cognitive scores and no associations between CD8+ TEMRAs and AD-related biomarkers. CD4+ TEMRAs were associated with cognitive impairment on the MMSE. Gender was not associated with TEMRAs, but it did show an association with other T cell populations. Conclusion These findings suggest that the accumulation of CD8+ TEMRAs may be a response to neuronal injury (Nf-L) and neuroinflammation (GFAP) during aging or the progression of AD and ADRD. As our findings in a community-based cohort were not clinically-defined AD participants but included all ADRDs, this suggests that TEMRAs may be associated with changes in systemic immune T cell subsets associated with the onset of pathology.
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Affiliation(s)
- Edric Winford
- Department of Neuroscience, University of Kentucky; Lexington, Kentucky, USA
| | - Jenny Lutshumba
- Department of Neuroscience, University of Kentucky; Lexington, Kentucky, USA
| | - Barbara J. Martin
- Sanders-Brown Center on Aging, University of Kentucky; Lexington, Kentucky, USA
| | - Donna M. Wilcock
- Sanders-Brown Center on Aging, University of Kentucky; Lexington, Kentucky, USA
- Department of Physiology, University of Kentucky, Lexington; Lexington, Kentucky, USA
| | - Gregory A. Jicha
- Department of Neurology, University of Kentucky; Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky; Lexington, Kentucky, USA
| | - Barbara S. Nikolajczyk
- Department of Pharmacology and Nutritional Science, and Barnstable Brown Diabetes and Obesity Center, University of Kentucky; Lexington, Kentucky, USA
| | - Ann M Stowe
- Department of Neuroscience, University of Kentucky; Lexington, Kentucky, USA
- Department of Neurology, University of Kentucky; Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky; Lexington, Kentucky, USA
| | - Adam D. Bachstetter
- Department of Neuroscience, University of Kentucky; Lexington, Kentucky, USA
- Sanders-Brown Center on Aging, University of Kentucky; Lexington, Kentucky, USA
- Spinal Cord and Brain Injury Research Center, University of Kentucky; Lexington, Kentucky, USA
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Zukowski E, Sannella M, Rockhold JD, Kalantar GH, Yu J, SantaCruz‐Calvo S, Kuhn MK, Hah N, Ouyang L, Wang T, Murphy L, Marszalkowski H, Gibney K, Drummond MJ, Proctor EA, Hasturk H, Nikolajczyk BS, Bharath LP. STAT3 modulates CD4 + T mitochondrial dynamics and function in aging. Aging Cell 2023; 22:e13996. [PMID: 37837188 PMCID: PMC10652300 DOI: 10.1111/acel.13996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 09/10/2023] [Accepted: 09/11/2023] [Indexed: 10/15/2023] Open
Abstract
Aging promotes numerous intracellular changes in T cells that impact their effector function. Our data show that aging promotes an increase in the localization of STAT3 to the mitochondria (mitoSTAT3), which promotes changes in mitochondrial dynamics and function and T-cell cytokine production. Mechanistically, mitoSTAT3 increased the activity of aging T-cell mitochondria by increasing complex II. Limiting mitoSTAT3 using a mitochondria-targeted STAT3 inhibitor, Mtcur-1 lowered complex II activity, prevented age-induced changes in mitochondrial dynamics and function, and reduced Th17 inflammation. Exogenous expression of a constitutively phosphorylated form of STAT3 in T cells from young adults mimicked changes in mitochondrial dynamics and function in T cells from older adults and partially recapitulated aging-related cytokine profiles. Our data show the mechanistic link among mitoSTAT3, mitochondrial dynamics, function, and T-cell cytokine production.
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Affiliation(s)
- Emelia Zukowski
- Department of Nutrition and Public HealthMerrimack CollegeNorth AndoverMassachusettsUSA
| | - Marco Sannella
- Department of Nutrition and Public HealthMerrimack CollegeNorth AndoverMassachusettsUSA
| | - Jack Donato Rockhold
- Department of Nutrition and Public HealthMerrimack CollegeNorth AndoverMassachusettsUSA
| | - Gabriella H. Kalantar
- Department of Microbiology, Immunology and Molecular GeneticsUniversity of KentuckyLexingtonKentuckyUSA
| | - Jingting Yu
- Razavi Newman Integrative Genomics and Bioinformatics CoreThe Salk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Sara SantaCruz‐Calvo
- Departments of Pharmacology and Nutritional SciencesUniversity of KentuckyLexingtonKentuckyUSA
- Barnstable Brown Diabetes and Obesity CenterUniversity of KentuckyLexingtonKentuckyUSA
| | - Madison K. Kuhn
- Departments of Neurosurgery, Pharmacology, and Biomedical Engineering and Center for Neural EngineeringPennsylvania State UniversityHersheyPennsylvaniaUSA
| | - Nasun Hah
- Next Generation Sequencing CoreThe Salk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Ling Ouyang
- Next Generation Sequencing CoreThe Salk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Tzu‐Wen Wang
- Next Generation Sequencing CoreThe Salk Institute for Biological StudiesLa JollaCaliforniaUSA
| | - Lyanne Murphy
- Department of BiologyMerrimack CollegeNorth AndoverMassachusettsUSA
| | | | - Kaleigh Gibney
- Department of Nutrition and Public HealthMerrimack CollegeNorth AndoverMassachusettsUSA
| | - Micah J. Drummond
- Department of Physical Therapy and Athletic TrainingUniversity of UtahSalt Lake CityUtahUSA
| | - Elizabeth A. Proctor
- Departments of Neurosurgery, Pharmacology, and Biomedical Engineering and Center for Neural EngineeringPennsylvania State UniversityHersheyPennsylvaniaUSA
- Department of Engineering Science & MechanicsPennsylvania State UniversityHersheyPennsylvaniaUSA
| | | | - Barbara S. Nikolajczyk
- Departments of Pharmacology and Nutritional SciencesUniversity of KentuckyLexingtonKentuckyUSA
- Barnstable Brown Diabetes and Obesity CenterUniversity of KentuckyLexingtonKentuckyUSA
| | - Leena P. Bharath
- Department of Nutrition and Public HealthMerrimack CollegeNorth AndoverMassachusettsUSA
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Bachstetter AD, Lutshumba J, Winford E, Abner EL, Martin BJ, Harp JP, Van Eldik LJ, Schmitt FA, Wilcock DM, Stowe AM, Jicha GA, Nikolajczyk BS. A blunted T H17 cytokine signature in women with mild cognitive impairment: insights from inflammatory profiling of a community-based cohort of older adults. Brain Commun 2023; 5:fcad259. [PMID: 37901041 PMCID: PMC10612408 DOI: 10.1093/braincomms/fcad259] [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: 11/22/2022] [Revised: 06/23/2023] [Accepted: 10/06/2023] [Indexed: 10/31/2023] Open
Abstract
People with dementia have an increase in brain inflammation, caused in part by innate and adaptive immune cells. However, it remains unknown whether dementia-associated diseases alter neuro-immune reflex arcs to impact the systemic immune system. We examined peripheral immune cells from a community-based cohort of older adults to test if systemic inflammatory cytokine signatures associated with early stages of cognitive impairment. Human peripheral blood mononuclear cells were cultured with monocyte or T-cell-targeted stimuli, and multiplex assays quantitated cytokines in the conditioned media. Following T-cell-targeted stimulation, cells from women with cognitive impairment produced lower amounts of TH17 cytokines compared with cells from cognitively healthy women, while myeloid-targeted stimuli elicited similar amounts of cytokines from cells of both groups. This TH17 signature correlated with the proportion of circulating CD4+ and CD8+ T cells and plasma glial fibrillary acidic protein and neurofilament light concentrations. These results suggest that decreases in TH17 cytokines could be an early systemic change in women at risk for developing dementia. Amelioration of TH17s cytokines in early cognitive impairment could, in part, explain the compromised ability of older adults to respond to vaccines or defend against infection.
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Affiliation(s)
- Adam D Bachstetter
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - Jenny Lutshumba
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - Edric Winford
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
| | - Erin L Abner
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Epidemiology, University of Kentucky, Lexington, KY 40536, USA
| | - Barbra J Martin
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - Jordan P Harp
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY 40536, USA
| | - Linda J Van Eldik
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
| | - Frederick A Schmitt
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY 40536, USA
- Department of Behavioral Sciences, University of Kentucky, Lexington, KY 40536, USA
| | - Donna M Wilcock
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Physiology, University of Kentucky, Lexington, KY 40536, USA
| | - Ann M Stowe
- Department of Neuroscience, University of Kentucky, Lexington, KY 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY 40536, USA
| | - Gregory A Jicha
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40536, USA
- Department of Neurology, University of Kentucky, Lexington, KY 40536, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Science, and Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY 40536, USA
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6
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Pugh GH, Fouladvand S, SantaCruz-Calvo S, Agrawal M, Zhang XD, Chen J, Kern PA, Nikolajczyk BS. T cells dominate peripheral inflammation in a cross-sectional analysis of obesity-associated diabetes. Obesity (Silver Spring) 2022; 30:1983-1994. [PMID: 36069294 PMCID: PMC9509440 DOI: 10.1002/oby.23528] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Revised: 05/16/2022] [Accepted: 06/07/2022] [Indexed: 11/10/2022]
Abstract
OBJECTIVE Myeloid cells dominate metabolic disease-associated inflammation (metaflammation) in mouse obesity, but the contributions of myeloid cells to the peripheral inflammation that fuels sequelae of human obesity are untested. This study used unbiased approaches to rank contributions of myeloid and T cells to peripheral inflammation in people with obesity across the spectrum of metabolic health. METHODS Peripheral blood mononuclear cells (PBMCs) from people with obesity with or without prediabetes or type 2 diabetes were stimulated with T cell-targeting CD3/CD28 or myeloid-targeting lipopolysaccharide for 20 to 72 hours to assess cytokine production using Bio-Plex. Bioinformatic modeling ranked cytokines with respect to their predictive power for metabolic health. Intracellular tumor necrosis factor α was quantitated as a classical indicator of metaflammation. RESULTS Cytokines increased over 72 hours following T cell-, but not myeloid-, targeted stimulation to indicate that acute myeloid inflammation may shift to T cell inflammation over time. T cells contributed more tumor necrosis factor α to peripheral inflammation regardless of metabolic status. Bioinformatic combination of cytokines from all cohorts, stimuli, and time points indicated that T cell-targeted stimulation was most important for differentiating inflammation in diabetes, consistent with previous identification of a mixed T helper type 1/T helper type 17 cytokine profile in diabetes. CONCLUSIONS T cells dominate peripheral inflammation in obesity; therefore, targeting T cells may be an effective approach for prevention/management of metaflammation.
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Affiliation(s)
- Gabriella H. Pugh
- Department of Microbiology, Immunology, & Molecular
Genetics, University of Kentucky Lexington, Kentucky, USA
| | - Sajjad Fouladvand
- Department of Computer Science, University of Kentucky
Lexington, Kentucky, USA
| | - Sara SantaCruz-Calvo
- Department of Pharmacology and Nutritional Sciences,
University of Kentucky Lexington, Kentucky, USA
| | - Madhur Agrawal
- Department of Pharmacology and Nutritional Sciences,
University of Kentucky Lexington, Kentucky, USA
| | | | - Jin Chen
- Department of Computer Science, University of Kentucky
Lexington, Kentucky, USA
| | - Philip A. Kern
- Department of Internal Medicine, University of Kentucky
Lexington, Kentucky, USA
- Barnstable Brown Diabetes Center, University of Kentucky
Lexington, Kentucky, USA
| | - Barbara S. Nikolajczyk
- Department of Microbiology, Immunology, & Molecular
Genetics, University of Kentucky Lexington, Kentucky, USA
- Department of Pharmacology and Nutritional Sciences,
University of Kentucky Lexington, Kentucky, USA
- Barnstable Brown Diabetes Center, University of Kentucky
Lexington, Kentucky, USA
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7
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Bharath LP, Hart SN, Nikolajczyk BS. T-cell Metabolism as Interpreted in Obesity-associated Inflammation. Endocrinology 2022; 163:6657752. [PMID: 35932471 PMCID: PMC9756079 DOI: 10.1210/endocr/bqac124] [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: 05/24/2022] [Indexed: 11/19/2022]
Abstract
The appreciation of metabolic regulation of T-cell function has exploded over the past decade, as has our understanding of how inflammation fuels comorbidities of obesity, including type 2 diabetes. The likelihood that obesity fundamentally alters T-cell metabolism and thus chronic obesity-associated inflammation is high, but studies testing causal relationships remain underrepresented. We searched PubMed for key words including mitochondria, obesity, T cell, type 2 diabetes, cristae, fission, fusion, redox, and reactive oxygen species to identify foundational and more recent studies that address these topics or cite foundational work. We investigated primary papers cited by reviews found in these searches and highlighted recent work with >100 citations to illustrate the state of the art in understanding mechanisms that control metabolism and thus function of various T-cell subsets in obesity. However, "popularity" of a paper over the first 5 years after publication cannot assess long-term impact; thus, some likely important work with fewer citations is also highlighted. We feature studies of human cells, supplementing with studies from animal models that suggest future directions for human cell research. This approach identified gaps in the literature that will need to be filled before we can estimate efficacy of mitochondria-targeted drugs in clinical trials to alleviate pathogenesis of obesity-associated inflammation.
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Affiliation(s)
- Leena P Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA 01845, USA
| | - Samantha N Hart
- Departments of Molecular and Cellular Biochemistry, University of Kentucky, Lexington, KY 40536, USA
| | - Barbara S Nikolajczyk
- Correspondence: Barbara S. Nikolajczyk, PhD, Healthy Kentucky Research Bldg. Rm. 217, 760 Press Ave, Lexington, KY 40536, USA.
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8
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Leachman JR, Cincinelli C, Ahmed N, Dalmasso C, Xu M, Gatineau E, Nikolajczyk BS, Yiannikouris F, Hinds TD, Loria AS. Early life stress exacerbates obesity in adult female mice via mineralocorticoid receptor-dependent increases in adipocyte triglyceride and glycerol content. Life Sci 2022; 304:120718. [PMID: 35714704 PMCID: PMC10987253 DOI: 10.1016/j.lfs.2022.120718] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 05/03/2022] [Revised: 06/02/2022] [Accepted: 06/10/2022] [Indexed: 01/06/2023]
Abstract
Previously, we have shown that Maternal Separation and Early Weaning (MSEW) exacerbates high fat diet (HF)-induced visceral obesity in female offspring compared to normally reared female mice. Stress hormones such as glucocorticoids and mineralocorticoids are critical mediators in the process of fat expansion, and both can activate the mineralocorticoid receptor (MR) in the adipocyte. Therefore, this study aimed to, comprehend the specific effects of MSEW on adipose tissue basic homeostatic function, and investigate whether female MSEW mice show an exacerbated obesogenic response mediated by MR. Gonadal white adipose tissue (gWAT), a type of visceral fat, was collected to assess lipidomics, transcriptomics, and in vitro lipolysis assay. Obese female MSEW mice showed increased adiposity, elevated 44:2/FA 18:2 + NH4 lipid class and reduced mitochondrial DNA density compared to obese control counterparts. In addition, single-cell RNA sequencing in isolated pre- and mature adipocytes showed a ~9-fold downregulation of aquaglycerolporin 3 (Aqp3), a channel responsible for glycerol efflux in adipocytes. Obese MSEW mice showed high levels of circulating aldosterone and gWAT-derived corticosterone compared to controls. Further, the MR blocker spironolactone (Spiro, 100 mg/kg/day, 2 weeks) normalized the elevated intracellular glycerol levels, the greater in vitro lipolysis response, and the number of large size adipocytes in MSEW mice compared to the controls. Our data suggests that MR plays a role promoting adipocyte hypertrophy in female MSEW mice by preventing lipolysis via glycerol release in favor of triglyceride formation and storage.
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Affiliation(s)
- Jacqueline R Leachman
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Cole Cincinelli
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Nermin Ahmed
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Carolina Dalmasso
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Mei Xu
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Eva Gatineau
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, USA
| | - Frederique Yiannikouris
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Terry D Hinds
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Barnstable Brown Diabetes Center, University of Kentucky College of Medicine, Lexington, KY, USA; Markey Cancer Center, University of Kentucky, Lexington, KY, USA
| | - Analia S Loria
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; SAHA Cardiovascular Center, University of Kentucky, Lexington, KY, USA.
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9
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Conway R, Rockhold JD, SantaCruz-Calvo S, Zukowski E, Pugh GH, Hasturk H, Kern PA, Nikolajczyk BS, Bharath LP. Obesity and Fatty Acids Promote Mitochondrial Translocation of STAT3 Through ROS-Dependent Mechanisms. Front Aging 2022; 3:924003. [PMID: 35928250 PMCID: PMC9344057 DOI: 10.3389/fragi.2022.924003] [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] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 06/08/2022] [Indexed: 11/29/2022]
Abstract
Obesity promotes the onset and progression of metabolic and inflammatory diseases such as type 2 diabetes. The chronic low-grade inflammation that occurs during obesity triggers multiple signaling mechanisms that negatively affect organismal health. One such mechanism is the persistent activation and mitochondrial translocation of STAT3, which is implicated in inflammatory pathologies and many types of cancers. STAT3 in the mitochondria (mitoSTAT3) alters electron transport chain activity, thereby influencing nutrient metabolism and immune response. PBMCs and CD4+ T cells from obese but normal glucose-tolerant (NGT) middle-aged subjects had higher phosphorylation of STAT3 on residue serine 727 and more mitochondrial accumulation of STAT3 than cells from lean subjects. To evaluate if circulating lipid overabundance in obesity is responsible for age- and sex-matched mitoSTAT3, cells from lean subjects were challenged with physiologically relevant doses of the saturated and monounsaturated fatty acids, palmitate and oleate, respectively. Fatty acid treatment caused robust accumulation of mitoSTAT3 in all cell types, which was independent of palmitate-induced impairments in autophagy. Co-treatment of cells with fatty acid and trehalose prevented STAT3 phosphorylation and mitochondrial accumulation in an autophagy-independent but cellular peroxide-dependent mechanism. Pharmacological blockade of mitoSTAT3 either by a mitochondria-targeted STAT3 inhibitor or ROS scavenging prevented obesity and fatty acid-induced production of proinflammatory cytokines IL-17A and IL-6, thus establishing a mechanistic link between mitoSTAT3 and inflammatory cytokine production.
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Affiliation(s)
- Rachel Conway
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, United States
| | - Jack Donato Rockhold
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, United States
| | - Sara SantaCruz-Calvo
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, United States
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, United States
| | - Emelia Zukowski
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, United States
| | - Gabriella H. Pugh
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, United States
| | | | - Philip A. Kern
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, United States
- Department of Medicine, University of Kentucky, Lexington, KY, United States
| | - Barbara S. Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, United States
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, United States
| | - Leena P. Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, United States
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10
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Bapat SP, Whitty C, Mowery CT, Liang Y, Yoo A, Jiang Z, Peters MC, Zhang LJ, Vogel I, Zhou C, Nguyen VQ, Li Z, Chang C, Zhu WS, Hastie AT, He H, Ren X, Qiu W, Gayer SG, Liu C, Choi EJ, Fassett M, Cohen JN, Sturgill JL, Crotty Alexander LE, Suh JM, Liddle C, Atkins AR, Yu RT, Downes M, Liu S, Nikolajczyk BS, Lee IK, Guttman-Yassky E, Ansel KM, Woodruff PG, Fahy JV, Sheppard D, Gallo RL, Ye CJ, Evans RM, Zheng Y, Marson A. Obesity alters pathology and treatment response in inflammatory disease. Nature 2022; 604:337-342. [PMID: 35355021 PMCID: PMC9165753 DOI: 10.1038/s41586-022-04536-0] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [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] [Received: 03/18/2021] [Accepted: 02/08/2022] [Indexed: 12/17/2022]
Abstract
Decades of work have elucidated cytokine signalling and transcriptional pathways that control T cell differentiation and have led the way to targeted biologic therapies that are effective in a range of autoimmune, allergic and inflammatory diseases. Recent evidence indicates that obesity and metabolic disease can also influence the immune system1-7, although the mechanisms and effects on immunotherapy outcomes remain largely unknown. Here, using two models of atopic dermatitis, we show that lean and obese mice mount markedly different immune responses. Obesity converted the classical type 2 T helper (TH2)-predominant disease associated with atopic dermatitis to a more severe disease with prominent TH17 inflammation. We also observed divergent responses to biologic therapies targeting TH2 cytokines, which robustly protected lean mice but exacerbated disease in obese mice. Single-cell RNA sequencing coupled with genome-wide binding analyses revealed decreased activity of nuclear receptor peroxisome proliferator-activated receptor-γ (PPARγ) in TH2 cells from obese mice relative to lean mice. Conditional ablation of PPARγ in T cells revealed that PPARγ is required to focus the in vivo TH response towards a TH2-predominant state and prevent aberrant non-TH2 inflammation. Treatment of obese mice with a small-molecule PPARγ agonist limited development of TH17 pathology and unlocked therapeutic responsiveness to targeted anti-TH2 biologic therapies. These studies reveal the effects of obesity on immunological disease and suggest a precision medicine approach to target the immune dysregulation caused by obesity.
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Affiliation(s)
- Sagar P Bapat
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA, USA.
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
- Medical Scientist Training Program, University of California, San Diego, La Jolla, CA, USA.
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA.
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
| | - Caroline Whitty
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Cody T Mowery
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
- Medical Scientist Training Program, University of California, San Francisco, CA, USA
| | - Yuqiong Liang
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Arum Yoo
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Zewen Jiang
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Michael C Peters
- Division of Pulmonary, Critical Care, Allergy and Sleep, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Ling-Juan Zhang
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
- Department of Dermatology, University of California, San Diego, La Jolla, CA, USA
| | - Ian Vogel
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
| | - Carmen Zhou
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Vinh Q Nguyen
- Department of Surgery, University of California, San Francisco, San Francisco, CA, USA
| | - Zhongmei Li
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Christina Chang
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Wandi S Zhu
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - Annette T Hastie
- School of Medicine, Wake Forest University, Winston-Salem, NC, USA
| | - Helen He
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Xin Ren
- Lung Biology Center, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Wenli Qiu
- Lung Biology Center, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Sarah G Gayer
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Chang Liu
- Department of Laboratory Medicine, University of California, San Francisco, San Francisco, CA, USA
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA
| | - Eun Jung Choi
- Department of Biomedical Science, Graduate School, Kyungpook National University, Kyungpook National University Hospital, Daegu, South Korea
| | - Marlys Fassett
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
| | - Jarish N Cohen
- Department of Dermatology, University of California, San Francisco, San Francisco, CA, USA
- Department of Pathology, University of California, San Francisco, San Francisco, CA, USA
| | - Jamie L Sturgill
- Department of Internal Medicine, Division of Pulmonary, Critical Care, and Sleep Medicine, University of Kentucky, Lexington, KY, USA
| | - Laura E Crotty Alexander
- Pulmonary Critical Care Section, Department of Medicine, Veterans Affairs San Diego Healthcare System, San Diego, CA, USA
- Division of Pulmonary Critical Care and Sleep Medicine, Department of Medicine, University of California, San Diego, CA, USA
| | - Jae Myoung Suh
- Graduate School of Medical Science and Engineering, KAIST, Daejeon, Republic of Korea
| | - Christopher Liddle
- Storr Liver Centre, Westmead Institute for Medical Research and Sydney Medical School, Westmead Hospital, University of Sydney, Westmead, New South Wales, Australia
| | - Annette R Atkins
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Ruth T Yu
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Michael Downes
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Sihao Liu
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences and the Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, USA
| | - In-Kyu Lee
- Department of Internal Medicine, School of Medicine, Kyungpook National University, Kyungpook National University Hospital, Daegu, South Korea
| | - Emma Guttman-Yassky
- Department of Dermatology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - K Mark Ansel
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA
- Sandler Asthma Basic Research Center, University of California, San Francisco, San Francisco, CA, USA
| | - Prescott G Woodruff
- Medical Scientist Training Program, University of California, San Francisco, CA, USA
| | - John V Fahy
- Medical Scientist Training Program, University of California, San Francisco, CA, USA
| | - Dean Sheppard
- Medical Scientist Training Program, University of California, San Francisco, CA, USA
- Lung Biology Center, Department of Medicine, University of California, San Francisco, San Francisco, CA, USA
| | - Richard L Gallo
- School of Pharmaceutical Sciences, Xiamen University, Xiamen, China
| | - Chun Jimmie Ye
- Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA, USA
- Institute for Computational Health Sciences, University of California, San Francisco, San Francisco, CA, USA
- Department of Epidemiology and Biostatistics, University of California, San Francisco, San Francisco, CA, USA
- Department of Bioengineering and Therapeutic Sciences, University of California, San Francisco, San Francisco, CA, USA
| | - Ronald M Evans
- Gene Expression Laboratory, The Salk Institute for Biological Studies, La Jolla, CA, USA.
| | - Ye Zheng
- NOMIS Center for Immunobiology and Microbial Pathogenesis, The Salk Institute for Biological Studies, La Jolla, CA, USA.
| | - Alexander Marson
- Department of Microbiology and Immunology, University of California, San Francisco, San Francisco, CA, USA.
- Diabetes Center, University of California, San Francisco, San Francisco, CA, USA.
- Department of Medicine, University of California, San Francisco, San Francisco, CA, USA.
- Institute for Human Genetics (IHG), University of California, San Francisco, San Francisco, CA, USA.
- Chan Zuckerberg Biohub, San Francisco, CA, USA.
- Innovative Genomics Institute, University of California, Berkeley, Berkeley, CA, USA.
- Parker Institute for Cancer Immunotherapy, San Francisco, CA, USA.
- UCSF Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, CA, USA.
- Gladstone-UCSF Institute of Genomic Immunology, San Francisco, CA, USA.
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11
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Liu R, Pugh GH, Tevonian E, Thompson K, Lauffenburger DA, Kern PA, Nikolajczyk BS. Regulatory T Cells Control Effector T Cell Inflammation in Human Prediabetes. Diabetes 2022; 71:264-274. [PMID: 34737186 PMCID: PMC8914282 DOI: 10.2337/db21-0659] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Accepted: 11/01/2021] [Indexed: 02/03/2023]
Abstract
A disparate array of plasma/serum markers provides evidence for chronic inflammation in human prediabetes, a condition that is most closely replicated by standard mouse models of obesity and metaflammation. These remain largely nonactionable and contrast with our rich understanding of inflammation in human type 2 diabetes. New data show that inflammatory profiles produced by CD4+ T cells define human prediabetes as a unique inflammatory state. Regulatory T cells (Treg) control mitochondrial function and cytokine production by CD4+ effector T cells (Teff) in prediabetes and type 2 diabetes by supporting T helper (Th)17 or Th1 cytokine production, respectively. These data suggest that Treg control of Teff metabolism regulates inflammation differentially in prediabetes compared with type 2 diabetes. Queries of genes that impact mitochondrial function or pathways leading to transcription of lipid metabolism genes identified the fatty acid importer CD36 as highly expressed in Treg but not Teff from subjects with prediabetes. Pharmacological blockade of CD36 in Treg from subjects with prediabetes decreased Teff production of the Th17 cytokines that differentiate overall prediabetes inflammation. We conclude that Treg control CD4+ T cell cytokine profiles through mechanisms determined, at least in part, by host metabolic status. Furthermore, Treg CD36 uniquely promotes Th17 cytokine production by Teff in prediabetes.
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Affiliation(s)
- Rui Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
| | - Gabriella H. Pugh
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY
| | - Erin Tevonian
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Katherine Thompson
- Dr. Bing Zhang Department of Statistics, University of Kentucky, Lexington, KY
| | | | - Philip A. Kern
- Department of Medicine, University of Kentucky, Lexington, KY
- Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY
| | - Barbara S. Nikolajczyk
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY
- Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY
- Corresponding author: Barbara S. Nikolajczyk,
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12
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SantaCruz-Calvo S, Bharath L, Pugh G, SantaCruz-Calvo L, Lenin RR, Lutshumba J, Liu R, Bachstetter AD, Zhu B, Nikolajczyk BS. Adaptive immune cells shape obesity-associated type 2 diabetes mellitus and less prominent comorbidities. Nat Rev Endocrinol 2022; 18:23-42. [PMID: 34703027 PMCID: PMC11005058 DOI: 10.1038/s41574-021-00575-1] [Citation(s) in RCA: 49] [Impact Index Per Article: 24.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/17/2021] [Indexed: 02/07/2023]
Abstract
Obesity and type 2 diabetes mellitus (T2DM) are increasing in prevalence owing to decreases in physical activity levels and a shift to diets that include addictive and/or high-calorie foods. These changes are associated with the adoption of modern lifestyles and the presence of an obesogenic environment, which have resulted in alterations to metabolism, adaptive immunity and endocrine regulation. The size and quality of adipose tissue depots in obesity, including the adipose tissue immune compartment, are critical determinants of overall health. In obesity, chronic low-grade inflammation can occur in adipose tissue that can progress to systemic inflammation; this inflammation contributes to the development of insulin resistance, T2DM and other comorbidities. An improved understanding of adaptive immune cell dysregulation that occurs during obesity and its associated metabolic comorbidities, with an appreciation of sex differences, will be critical for repurposing or developing immunomodulatory therapies to treat obesity and/or T2DM-associated inflammation. This Review critically discusses how activation and metabolic reprogramming of lymphocytes, that is, T cells and B cells, triggers the onset, development and progression of obesity and T2DM. We also consider the role of immunity in under-appreciated comorbidities of obesity and/or T2DM, such as oral cavity inflammation, neuroinflammation in Alzheimer disease and gut microbiome dysbiosis. Finally, we discuss previous clinical trials of anti-inflammatory medications in T2DM and consider the path forward.
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Affiliation(s)
- Sara SantaCruz-Calvo
- Department of Pharmacology and Nutritional Sciences and the Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA.
| | - Leena Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, USA
| | - Gabriella Pugh
- Department of Microbiology, Immunology and Molecular Genetics, University of Kentucky, Lexington, KY, USA
| | - Lucia SantaCruz-Calvo
- Department of Chemistry and Food Technology, Technical University of Madrid, Madrid, Spain
| | - Raji Rajesh Lenin
- Department of Pharmacology and Nutritional Sciences and the Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
| | - Jenny Lutshumba
- Department of Neuroscience, University of Kentucky, Lexington, KY, USA
| | - Rui Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | | | - Beibei Zhu
- Department of Pharmacology and Nutritional Sciences and the Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences and the Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA.
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13
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Abstract
Neuroinflammation and the tissue-resident innate immune cells, the microglia, respond and contribute to neurodegenerative pathology. Although microglia have been the focus of work linking neuroinflammation and associated dementias like Alzheimer's Disease, the inflammatory milieu of brain is a conglomerate of cross-talk amongst microglia, systemic immune cells and soluble mediators like cytokines. Age-related changes in the inflammatory profile at the levels of both the brain and periphery are largely orchestrated by immune system cells. Strong evidence indicates that both innate and adaptive immune cells, the latter including T cells and B cells, contribute to chronic neuroinflammation and thus dementia. Neurodegenerative hallmarks coupled with more traditional immune system stimuli like infection or injury likely combine to trigger and maintain persistent microglial and thus brain inflammation. This review summarizes age-related changes in immune cell function, with special emphasis on lymphocytes as a source of inflammation, and discusses how such changes may potentiate both systemic and central nervous system inflammation to culminate in dementia. We recap the understudied area of AD-associated changes in systemic lymphocytes in greater detail to provide a unifying perspective of inflammation-fueled dementia, with an eye toward evidence of two-way communication between the brain parenchyma and blood immune cells. We focused our review on human subjects studies, adding key data from animal models as relevant.
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Affiliation(s)
- Jenny Lutshumba
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States
| | - Barbara S. Nikolajczyk
- Department of Pharmacology and Nutritional Science, University of Kentucky, Lexington, KY, United States
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, United States
| | - Adam D. Bachstetter
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, United States
- Department of Neuroscience, University of Kentucky, Lexington, KY, United States
- Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY, United States
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14
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Abstract
The biguanide metformin is the most commonly used antidiabetic drug. Recent studies show that metformin not only improves chronic inflammation by improving metabolic parameters but also has a direct anti-inflammatory effect. In light of these findings, it is essential to identify the inflammatory pathways targeted by metformin to develop a comprehensive understanding of the mechanisms of action of this drug. Commonly accepted mechanisms of metformin action include AMPK activation and inhibition of mTOR pathways, which are evaluated in multiple diseases. Additionally, metformin's action on mitochondrial function and cellular homeostasis processes such as autophagy is of particular interest because of the importance of these mechanisms in maintaining cellular health. Both dysregulated mitochondria and failure of the autophagy pathways, the latter of which impair clearance of dysfunctional, damaged, or excess organelles, affect cellular health drastically and can trigger the onset of metabolic and age-related diseases. Immune cells are the fundamental cell types that govern the health of an organism. Thus, dysregulation of autophagy or mitochondrial function in immune cells has a remarkable effect on susceptibility to infections, response to vaccination, tumor onset, and the development of inflammatory and autoimmune conditions. In this study, we summarize the latest research on metformin's regulation of immune cell mitochondrial function and autophagy as evidence that new clinical trials on metformin with primary outcomes related to the immune system should be considered to treat immune-mediated diseases over the near term.
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Affiliation(s)
- Leena P Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, Massachusetts
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences and Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, Kentucky
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15
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Bharath LP, Nikolajczyk BS. Next steps in mechanisms of inflammaging. Autophagy 2020; 16:2285-2286. [PMID: 32960694 DOI: 10.1080/15548627.2020.1822089] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
Abstract
Striking age-related changes occur in the human immune system, beginning in the sixth decade of life. Age is a non-modifiable, universal risk factor that results in the dysregulation of many cellular homeostatic processes. The decline in immune cell macroautophagy/autophagy and the increased generation of proinflammatory cytokines during agingfuels the development of diseases in the elderly. We reported that higher Th17 inflammation during aging was secondary to dysregulation in T cell autophagy. However, the mechanism underlying lower anti-CD3 and anti-CD28 activation-induced T cell autophagy during aging remain unknown. Our data fuel the speculation that dysregulation of the glutathione (GSH) system might cause the decline in T cell autophagy in aging, additionally provoked by reactive oxygen species signaling emanating from the mitochondria.
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Affiliation(s)
- Leena P Bharath
- Department of Nutrition and Public Health, Merrimack College , North Andover, MA, USA
| | - Barbara S Nikolajczyk
- Departments of Pharmacology and Nutritional Sciences, Barnstable Brown Diabetes and Obesity Center, University of Kentucky , Lexington, KY, USA
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16
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Bharath LP, Agrawal M, McCambridge G, Nicholas DA, Hasturk H, Liu J, Jiang K, Liu R, Guo Z, Deeney J, Apovian CM, Snyder-Cappione J, Hawk GS, Fleeman RM, Pihl RMF, Thompson K, Belkina AC, Cui L, Proctor EA, Kern PA, Nikolajczyk BS. Metformin Enhances Autophagy and Normalizes Mitochondrial Function to Alleviate Aging-Associated Inflammation. Cell Metab 2020; 32:44-55.e6. [PMID: 32402267 PMCID: PMC7217133 DOI: 10.1016/j.cmet.2020.04.015] [Citation(s) in RCA: 295] [Impact Index Per Article: 73.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 01/28/2020] [Accepted: 04/20/2020] [Indexed: 12/20/2022]
Abstract
Age is a non-modifiable risk factor for the inflammation that underlies age-associated diseases; thus, anti-inflammaging drugs hold promise for increasing health span. Cytokine profiling and bioinformatic analyses showed that Th17 cytokine production differentiates CD4+ T cells from lean, normoglycemic older and younger subjects, and mimics a diabetes-associated Th17 profile. T cells from older compared to younger subjects also had defects in autophagy and mitochondrial bioenergetics that associate with redox imbalance. Metformin ameliorated the Th17 inflammaging profile by increasing autophagy and improving mitochondrial bioenergetics. By contrast, autophagy-targeting siRNA disrupted redox balance in T cells from young subjects and activated the Th17 profile by activating the Th17 master regulator, STAT3, which in turn bound IL-17A and F promoters. Mitophagy-targeting siRNA failed to activate the Th17 profile. We conclude that metformin improves autophagy and mitochondrial function largely in parallel to ameliorate a newly defined inflammaging profile that echoes inflammation in diabetes.
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Affiliation(s)
- Leena P Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, USA
| | - Madhur Agrawal
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA
| | - Grace McCambridge
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA, USA
| | - Dequina A Nicholas
- Department of Obstetrics, Gynecology, and Reproductive Sciences, School of Medicine, University of California, San Diego, San Diego, CA, USA
| | | | - Jing Liu
- Department of Computer Science, University of Kentucky, Lexington, KY, USA
| | - Kai Jiang
- Department of Physiology, University of Kentucky, Lexington, KY, USA
| | - Rui Liu
- Department of Pharmaceutical Sciences, University of Kentucky, Lexington, KY, USA
| | - Zhenheng Guo
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA
| | - Jude Deeney
- Department of Medicine, Endocrinology, Diabetes & Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Caroline M Apovian
- Department of Medicine, Endocrinology, Diabetes & Nutrition, Boston University School of Medicine, Boston, MA, USA
| | - Jennifer Snyder-Cappione
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA; Flow Cytometry Core Facility, Boston University School of Medicine, Boston, MA, USA
| | - Gregory S Hawk
- Department of Statistics, University of Kentucky, Lexington, KY, USA
| | - Rebecca M Fleeman
- Departments of Neurosurgery and Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, USA
| | - Riley M F Pihl
- Flow Cytometry Core Facility, Boston University School of Medicine, Boston, MA, USA
| | | | - Anna C Belkina
- Flow Cytometry Core Facility, Boston University School of Medicine, Boston, MA, USA; Department of Pathology and Laboratory Medicine, Boston University School of Medicine, Boston, MA, USA
| | - Licong Cui
- Department of Computer Science, University of Kentucky, Lexington, KY, USA; School of Biomedical Informatics, University of Texas Health Science Center at Houston, Houston, TX, USA
| | - Elizabeth A Proctor
- Departments of Neurosurgery and Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, USA; Departments of Biomedical Engineering, and Engineering Science & Mechanics and Center for Neural Engineering, Pennsylvania State University, University Park, PA, USA
| | - Philip A Kern
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA; Department of Medicine, University of Kentucky, Lexington, KY, USA
| | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY, USA; Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY, USA.
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17
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Belkina AC, Azer M, Lee JJ, Elgaali HH, Pihl R, Cleveland M, Carr J, Kim S, Habib C, Hasturk H, Snyder-Cappione JE, Nikolajczyk BS. Single-Cell Analysis of the Periodontal Immune Niche in Type 2 Diabetes. J Dent Res 2020; 99:855-862. [PMID: 32186942 DOI: 10.1177/0022034520912188] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [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: 12/17/2022] Open
Abstract
Periodontitis (PD) is a common source of uncontrolled inflammation in obesity-associated type 2 diabetes (T2D). PD apparently fuels the inflammation of T2D and associates with poor glycemic control and increased T2D morbidity. New therapeutics are critically needed to counter the sources of periodontal infection and inflammation that are accelerated in people with T2D. The precise mechanisms underlying the relationship between PD and T2D remain poorly understood. Every major immune cell subset has been implicated in the unresolved inflammation of PD, regardless of host metabolic health. However, analyses of inflammatory cells in PD with human periodontal tissue have generally focused on mRNA quantification and immunohistochemical analyses, both of which provide limited information on immune cell function. We used a combination of flow cytometry for cell surface markers and enzyme-linked immunospot methods to assess the subset distribution and function of immune cells isolated from gingiva of people who had PD and were systemically healthy, had PD and T2D (PD/T2D), or, for flow cytometry, were systemically and orally healthy. T-cell subsets dominated the cellular immune compartment in gingiva from all groups, and B cells were relatively rare. Although immune cell frequencies were similar among groups, a higher proportion of CD11b+ or CD4+ cells secreted IFNγ/IL-10 or IL-8, respectively, in cells from PD/T2D samples as compared with PD-alone samples. Our data indicate that fundamental differences in gingival immune cell function between PD and T2D-potentiated PD may account for the increased risk and severity of PD in subjects with T2D. Such differences may suggest unexpected therapeutic targets for alleviating periodontal inflammation in people with T2D.
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Affiliation(s)
- A C Belkina
- Department of Pathology and Laboratory Medicine, School of Medicine, Boston University, Boston, MA, USA.,Flow Cytometry Core Facility, School of Medicine, Boston University, Boston, MA, USA
| | - M Azer
- Department of Oral Biology, Goldman School of Dental Medicine, Boston University, Boston, MA, USA
| | - J J Lee
- Department of Pharmacology and Nutritional Sciences and Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, USA
| | - H H Elgaali
- Department of Pharmacology and Nutritional Sciences and Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, USA
| | - R Pihl
- Flow Cytometry Core Facility, School of Medicine, Boston University, Boston, MA, USA
| | - M Cleveland
- Department of Pharmacology and Nutritional Sciences and Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, USA
| | - J Carr
- Department of Microbiology, School of Medicine, Boston University, Boston, MA, USA
| | - S Kim
- Department of Medicine, School of Medicine, Boston University, Boston, MA, USA
| | - C Habib
- Department of Medicine, School of Medicine, Boston University, Boston, MA, USA
| | - H Hasturk
- The Forsyth Institute, Cambridge, MA, USA
| | - J E Snyder-Cappione
- Flow Cytometry Core Facility, School of Medicine, Boston University, Boston, MA, USA.,Department of Microbiology, School of Medicine, Boston University, Boston, MA, USA
| | - B S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences and Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, USA.,Department of Microbiology, School of Medicine, Boston University, Boston, MA, USA
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18
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Abstract
Obesity-associated inflammation stems from a combination of cell-intrinsic changes of individual immune cell subsets and the dynamic crosstalk amongst a broad array of immune cells. Although much of the focus of immune cell contributions to metabolic disease has focused on adipose tissue-associated cells, these potent sources of inflammation inhabit other metabolic regulatory tissues, including liver and gut, and recirculate to promote systemic inflammation and thus obesity comorbidities. Tissue-associated immune cells, especially T cell subpopulations, have become a hotspot of inquiry based on their contributions to obesity, type 2 diabetes, non-alcoholic fatty liver diseases and certain types of cancers. The cell-cell interactions that take place under the stress of obesity are mediated by intracellular contact and cytokine production, and constitute a complicated network that drives the phenotypic alterations of immune cells and perpetuates a feed-forward loop of metabolic decline. Herein we discuss immune cell functions in various tissues and obesity-associated cancers from the viewpoint of inflammation. We also emphasize recent advances in the understanding of crosstalk amongst immune cell subsets under obese conditions, and suggest future directions for focused investigations with clinical relevance.
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Affiliation(s)
- Rui Liu
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY, United States
| | - Barbara S. Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, Barnstable Brown Diabetes and Obesity Research Center, University of Kentucky, Lexington, KY, United States
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19
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Agrawal M, Nicholas DA, Proctor EA, Belkina AC, Jones A, Panneerseelan-Bharath L, Raval F, Ip B, Zhu M, Cacicedo J, Habib C, Sainz-Rueda N, Persky L, Sullivan PG, Corkey BE, Apovian CM, Kern PA, Lauffenburger DA, Nikolajczyk BS. Mitochondrial changes synergize with long chain fatty acid derivatives to support Th17 inflammation in diabetes. The Journal of Immunology 2019. [DOI: 10.4049/jimmunol.202.supp.182.25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Obesity-associated Type 2 diabetes (T2D) is driven by chronic inflammation. A combinatorial Th17 cytokine profile characterizes and mathematically predicts T2D in people, but the mechanisms that generate the Th17 profile are not clear. We tested the possibility that anaerobic glycolysis, which fuels inflammatory cytokine production from multiple immune cell types, drives the T2D-associated Th17 profile. We showed that activated PBMCs and purified CD4+T cells from T2D subjects prefer anaerobic glucose metabolism to produce ATP regardless of fuel availability. Unexpectedly, glucose starvation did not abrogate the T2D-predictive Th17 profile. Gene expression array suggested that mitochondrial fatty acid uptake catalyzing protein CPT1a differentiated PBMCs from T2D and ND subjects. CPT1a inhibition by etomoxir strongly down-regulated the Th17 profile, surprisingly independent of CPT1a-mediated fatty acid oxidation (OXPHOS). These data suggest that OXPHOS-independent mitochondrial changes that are also glucose-independent support the Th17 profile in T2D. Analyses from T2D vs ND PBMCs showed a lower CACT:CPT1a protein ratio in T2D, indicating defects in lipid uptake and thus defects in lipid flux. We knocked down CACT protein and overloaded PBMCs from lean subjects with fatty acylcarnitines to mimic lipid uptake defects in T2D. 16C-fatty acylcarnitine, but not 6C- or 10C-derivatives, increased frequency of CD4+IL-17+T cells, and phenocopied the Th17 profile only in CACT knockdown cells. 16C-fatty acylcarnitine alone had no effect. We conclude that excessive long chain fatty acylcarnitine combines with dysfunctional mitochondria to support a T2D-associated Th17 profile largely independent of glycolysis.
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20
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McCambridge G, Agrawal M, Keady A, Kern PA, Hasturk H, Nikolajczyk BS, Bharath LP. Saturated Fatty Acid Activates T Cell Inflammation Through a Nicotinamide Nucleotide Transhydrogenase (NNT)-Dependent Mechanism. Biomolecules 2019; 9:biom9020079. [PMID: 30823587 PMCID: PMC6406569 DOI: 10.3390/biom9020079] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Revised: 02/19/2019] [Accepted: 02/19/2019] [Indexed: 01/17/2023] Open
Abstract
Circulating fatty acids (FAs) increase with obesity and can drive mitochondrial damage and inflammation. Nicotinamide nucleotide transhydrogenase (NNT) is a mitochondrial protein that positively regulates nicotinamide adenine dinucleotide phosphate (NADPH), a key mediator of energy transduction and redox homeostasis. The role that NNT-regulated bioenergetics play in the inflammatory response of immune cells in obesity is untested. Our objective was to determine how free fatty acids (FFAs) regulate inflammation through impacts on mitochondria and redox homeostasis of peripheral blood mononuclear cells (PBMCs). PBMCs from lean subjects were activated with a T cell-specific stimulus in the presence or absence of generally pro-inflammatory palmitate and/or non-inflammatory oleate. Palmitate decreased immune cell expression of NNT, NADPH, and anti-oxidant glutathione, but increased reactive oxygen and proinflammatory Th17 cytokines. Oleate had no effect on these outcomes. Genetic inhibition of NNT recapitulated the effects of palmitate. PBMCs from obese (BMI >30) compared to lean subjects had lower NNT and glutathione expression, and higher Th17 cytokine expression, none of which were changed by exogenous palmitate. Our data identify NNT as a palmitate-regulated rheostat of redox balance that regulates immune cell function in obesity and suggest that dietary or therapeutic strategies aimed at increasing NNT expression may restore redox balance to ameliorate obesity-associated inflammation.
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Affiliation(s)
- Grace McCambridge
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA 01845, USA.
| | - Madhur Agrawal
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40506, USA.
| | - Alanna Keady
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA 01845, USA.
| | - Philip A Kern
- Department of Medicine, University of Kentucky, Lexington, KY 40506, USA.
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY 40506, USA.
| | | | - Barbara S Nikolajczyk
- Department of Pharmacology and Nutritional Sciences, University of Kentucky, Lexington, KY 40506, USA.
- Barnstable Brown Diabetes and Obesity Center, University of Kentucky, Lexington, KY 40506, USA.
| | - Leena P Bharath
- Department of Nutrition and Public Health, Merrimack College, North Andover, MA 01845, USA.
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21
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Nikolajczyk BS, Dawson DR. Origin of Th17 Cells in Type 2 Diabetes-Potentiated Periodontal Disease. Oral Mucosal Immunity and Microbiome 2019; 1197:45-54. [DOI: 10.1007/978-3-030-28524-1_4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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22
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Jones IV AR, Coleman EL, Husni NR, Deeney JT, Raval F, Steenkamp D, Dooms H, Nikolajczyk BS, Corkey BE. Type 1 diabetes alters lipid handling and metabolism in human fibroblasts and peripheral blood mononuclear cells. PLoS One 2017; 12:e0188474. [PMID: 29206239 PMCID: PMC5714353 DOI: 10.1371/journal.pone.0188474] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 11/07/2017] [Indexed: 01/05/2023] Open
Abstract
Triggers of the autoimmune response that leads to type 1 diabetes (T1D) remain poorly understood. A possibility is that parallel changes in both T cells and target cells provoke autoimmune attack. We previously documented greater Ca2+ transients in fibroblasts from T1D subjects than non-T1D after exposure to fatty acids (FA) and tumor necrosis factor α (TNFα). These data indicate that metabolic and signal transduction defects present in T1D can be elicited ex vivo in isolated cells. Changes that precede T1D, including inflammation, may activate atypical responses in people that are genetically predisposed to T1D. To identify such cellular differences in T1D, we quantified a panel of metabolic responses in fibroblasts and peripheral blood cells (PBMCs) from age-matched T1D and non-T1D subjects, as models for non-immune and immune cells, respectively. Fibroblasts from T1D subjects accumulated more lipid, had higher LC-CoA levels and converted more FA to CO2, with less mitochondrial proton leak in response to oleate alone or with TNFα, using the latter as a model of inflammation. T1D-PBMCs contained and also accumulated more lipid following FA exposure. In addition, they formed more peroxidized lipid than controls following FA exposure. We conclude that both immune and non-immune cells in T1D subjects differ from controls in terms of responses to FA and TNFα. Our results suggest a differential sensitivity to inflammatory insults and FA that may precede and contribute to T1D by priming both immune cells and their targets for autoimmune reactions.
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Affiliation(s)
- Albert R. Jones IV
- Obesity Research Center, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Emily L. Coleman
- Yale University School of Medicine, New Haven, CT, United States of America
| | - Nicholas R. Husni
- Obesity Research Center, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Jude T. Deeney
- Obesity Research Center, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Forum Raval
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Devin Steenkamp
- Endocrinology Section, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Hans Dooms
- Rheumatology Section, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Barbara S. Nikolajczyk
- Department of Translational Research in Diabetes, University of Kentucky School of Medicine, Lexington, KY, United States of America
- Department of Pharmacology and Nutritional Sciences, University of Kentucky School of Medicine, Lexington, KY, United States of America
| | - Barbara E. Corkey
- Obesity Research Center, Evans Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
- * E-mail:
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23
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Abstract
Adipose tissue (AT) is the primary energy reservoir organ, and thereby plays a critical role in energy homeostasis and regulation of metabolism. AT expands in response to chronic overnutrition or aging and becomes a major source of inflammation that has marked influence on systemic metabolism. The chronic, sterile inflammation that occurs in the AT during the development of obesity or in aging contributes to onset of devastating diseases such as insulin resistance, diabetes, and cardiovascular pathologies. Numerous studies have shown that inflammation in the visceral AT of humans and animals is a critical trigger for the development of metabolic syndrome. This work underscores the well-supported conclusion that the inflammatory immune response and metabolic pathways in the AT are tightly interwoven by multiple layers of relatively conserved mechanisms. During the development of diet-induced obesity or age-associated adiposity, cells of the innate and the adaptive immune systems infiltrate and proliferate in the AT. Macrophages, which dominate AT-associated immune cells in mouse models of obesity, but are less dominant in obese people, have been studied extensively. However, cells of the adaptive immune system, including T cells and B cells, contribute significantly to AT inflammation, perhaps more in humans than in mice. Lymphocytes regulate recruitment of innate immune cells into AT, and produce cytokines that influence the helpful-to-harmful inflammatory balance that, in turn, regulates organismal metabolism. This review describes inflammation, or more precisely, metabolic inflammation (metaflammation) with an eye toward the AT and the roles lymphocytes play in regulation of systemic metabolism during obesity and aging. © 2017 American Physiological Society. Compr Physiol 7:1307-1337, 2017.
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Affiliation(s)
- Leena P Bharath
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Blanche C Ip
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA.,Department of Molecular Pharmacology, Physiology and Biotechnology, Center of Biomedical Engineering, Brown University, Providence, Rhode Island, USA
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24
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Abstract
PURPOSE OF REVIEW Adipose tissue (AT) houses both innate and adaptive immune systems that are crucial for preserving AT function and metabolic homeostasis. In this review, we summarize recent information regarding progression of obesity-associated AT inflammation and insulin resistance. We additionally consider alterations in AT distribution and the immune system in males vs. females and among different racial populations. RECENT FINDINGS Innate and adaptive immune cell-derived inflammation drives insulin resistance both locally and systemically. However, new evidence also suggests that the immune system is equally vital for adipocyte differentiation and protection from ectopic lipid deposition. Furthermore, roles of anti-inflammatory immune cells such as regulatory T cells, "M2-like" macrophages, eosinophils, and mast cells are being explored, primarily due to promise of immunotherapeutic applications. Both immune responses and AT distribution are strongly influenced by factors like sex and race, which have been largely underappreciated in the field of metabolically-associated inflammation, or meta-flammation. More studies are required to recognize factors that switch inflammation from controlled to uncontrolled in obesity-associated pathogenesis and to integrate the combined effects of meta-flammation and immunometabolism. It is critical to recognize that the AT-associated immune system can be alternately beneficial and destructive; therefore, simply blocking immune responses early in obesity may not be the best clinical approach. The dearth of information on gender and race-associated disparities in metabolism, AT distribution, and the immune system suggest that a greater understanding of such differences will be critical to develop personalized treatments for obesity and the associated metabolic dysfunction.
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Affiliation(s)
- Madhur Agrawal
- Department of Microbiology, Boston University School of Medicine, 72 East Concord Street L-516, Boston, MA, 02118, USA
| | - Philip A Kern
- Department of Medicine, Division of Endocrinology, University of Kentucky, Lexington, KY, USA
| | - Barbara S Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, 72 East Concord Street L-516, Boston, MA, 02118, USA.
- Department of Pathology, Boston University School of Medicine, Boston, MA, USA.
- Department of Molecular and Cell Biology, Boston University Goldman School of Dental Medicine, Boston, MA, USA.
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25
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Nicholas D, Proctor EA, Jones A, Raval F, Habib C, Corkey B, Apovian CM, Lauffenburger DA, Nikolajczyk BS. Fatty Acid Uptake Unexpectedly Supports a Th17 cytokine signature in Type 2 Diabetes (T2D) Inflammation. The Journal of Immunology 2017. [DOI: 10.4049/jimmunol.198.supp.197.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Abstract
Metabolism controls T cell function, but the role of cellular metabolism in regulating our published T2D-associated Th17 cytokine signature is untested. Published work showed Th17 function requires fatty acid (FA) uptake, and suggested Th17s burn fat to support inflammation. We thus hypothesized that chronic exposure of immune cells to FAs, which occurs in T2D patients, drives Th17 inflammation. We used extracellular flux (XF) and cytokine analyses to show that CD3/CD28-stimulated PBMCs from BMI-matched T2D vs. non-T2D subjects were more glycolytic despite overall equal mitochondrial respiration. Consistent with this difference, T cell stimulation in glucose-free media followed by partial least squares analysis of cytokines showed glucose impacted cytokine profiles from T2D and non-T2D cells differently. To challenge the resulting prediction that PBMCs (predominantly T cells) from the two groups used different mechanisms to fuel cytokine responses, we performed XF analysis in the presence of FA +/− glucose. Non-T2D cells utilized FA as a fuel source, but T2D cells were dependent on glucose, despite data showing diabetic vs. non-T2D PBMCs store more lipid in response to elevated exogenous FA. Etomoxir, an inhibitor of FA transport into the mitochondria, caused non-T2D cells to increase glycolysis, but had no effect on T2D cells. These data confirmed that T2D cells exclusively burn glucose, not FA, to generate energy, and that T2D cells cannot be forced to use FA as a fuel. Finally, blockade of FA transport into the mitochondria revealed that FAs were associated with Th17 cytokine production. Together, our results support the unexpected conclusion that FA uptake is uncoupled from FA oxidation to drive the Th17 inflammation in T2D.
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26
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Nicholas D, Proctor EA, Raval FM, Ip BC, Habib C, Ritou E, Grammatopoulos TN, Steenkamp D, Dooms H, Apovian CM, Lauffenburger DA, Nikolajczyk BS. Advances in the quantification of mitochondrial function in primary human immune cells through extracellular flux analysis. PLoS One 2017; 12:e0170975. [PMID: 28178278 PMCID: PMC5298256 DOI: 10.1371/journal.pone.0170975] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Accepted: 01/13/2017] [Indexed: 01/28/2023] Open
Abstract
Numerous studies show that mitochondrial energy generation determines the effectiveness of immune responses. Furthermore, changes in mitochondrial function may regulate lymphocyte function in inflammatory diseases like type 2 diabetes. Analysis of lymphocyte mitochondrial function has been facilitated by introduction of 96-well format extracellular flux (XF96) analyzers, but the technology remains imperfect for analysis of human lymphocytes. Limitations in XF technology include the lack of practical protocols for analysis of archived human cells, and inadequate data analysis tools that require manual quality checks. Current analysis tools for XF outcomes are also unable to automatically assess data quality and delete untenable data from the relatively high number of biological replicates needed to power complex human cell studies. The objectives of work presented herein are to test the impact of common cellular manipulations on XF outcomes, and to develop and validate a new automated tool that objectively analyzes a virtually unlimited number of samples to quantitate mitochondrial function in immune cells. We present significant improvements on previous XF analyses of primary human cells that will be absolutely essential to test the prediction that changes in immune cell mitochondrial function and fuel sources support immune dysfunction in chronic inflammatory diseases like type 2 diabetes.
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Affiliation(s)
- Dequina Nicholas
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Elizabeth A. Proctor
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Forum M. Raval
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Blanche C. Ip
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
| | - Chloe Habib
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Eleni Ritou
- BioEnergetics LLC, Boston, MA, United States of America
| | | | - Devin Steenkamp
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Hans Dooms
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
- Arthritis Center, Boston University School of Medicine, Boston, MA, United States of America
| | - Caroline M. Apovian
- Department of Medicine, Boston University School of Medicine, Boston, MA, United States of America
| | - Douglas A. Lauffenburger
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States of America
| | - Barbara S. Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston, MA, United States of America
- Department of Pathology, Boston University School of Medicine, Boston, MA, United States of America
- Department of Molecular and Cell Biology, Boston University School of Medicine, Boston, MA, United States of America
- * E-mail:
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27
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Nicholas DA, Andrieu G, Strissel KJ, Nikolajczyk BS, Denis GV. BET bromodomain proteins and epigenetic regulation of inflammation: implications for type 2 diabetes and breast cancer. Cell Mol Life Sci 2017; 74:231-243. [PMID: 27491296 PMCID: PMC5222701 DOI: 10.1007/s00018-016-2320-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 07/16/2016] [Accepted: 07/29/2016] [Indexed: 12/18/2022]
Abstract
Chronic inflammation drives pathologies associated with type 2 diabetes (T2D) and breast cancer. Obesity-driven inflammation may explain increased risk and mortality of breast cancer with T2D reported in the epidemiology literature. Therapeutic approaches to target inflammation in both T2D and cancer have so far fallen short of the expected improvements in disease pathogenesis or outcomes. The targeting of epigenetic regulators of cytokine transcription and cytokine signaling offers one promising, untapped approach to treating diseases driven by inflammation. Recent work has deeply implicated the Bromodomain and Extra-Terminal domain (BET) proteins, which are acetylated histone "readers", in epigenetic regulation of inflammation. This review focuses on inflammation associated with T2D and breast cancer, and the possibility of targeting BET proteins as an approach to regulating inflammation in the clinic. Understanding inflammation in the context of BET protein regulation may provide a basis for designing promising therapeutics for T2D and breast cancer.
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Affiliation(s)
- Dequina A Nicholas
- Cancer Center, Boston University School of Medicine, 72 East Concord Street, Room K520, Boston, MA, 02118, USA
- Department of Microbiology, Training Program in Inflammatory Disorders, 72 East Concord Street, K520, Boston, MA, 02118, USA
| | - Guillaume Andrieu
- Cancer Center, Boston University School of Medicine, 72 East Concord Street, Room K520, Boston, MA, 02118, USA
| | - Katherine J Strissel
- Cancer Center, Boston University School of Medicine, 72 East Concord Street, Room K520, Boston, MA, 02118, USA
| | - Barbara S Nikolajczyk
- Department of Microbiology, Training Program in Inflammatory Disorders, 72 East Concord Street, K520, Boston, MA, 02118, USA
| | - Gerald V Denis
- Cancer Center, Boston University School of Medicine, 72 East Concord Street, Room K520, Boston, MA, 02118, USA.
- Section of Hematology/Oncology, Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, 72 East Concord Street, K520, Boston, MA, 02118, USA.
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28
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Lentucci C, Belkina AC, Cederquist CT, Chan M, Johnson HE, Prasad S, Lopacinski A, Nikolajczyk BS, Monti S, Snyder-Cappione J, Tanasa B, Cardamone MD, Perissi V. Inhibition of Ubc13-mediated Ubiquitination by GPS2 Regulates Multiple Stages of B Cell Development. J Biol Chem 2016; 292:2754-2772. [PMID: 28039360 DOI: 10.1074/jbc.m116.755132] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 12/21/2016] [Indexed: 12/12/2022] Open
Abstract
Non-proteolytic ubiquitin signaling mediated by Lys63 ubiquitin chains plays a critical role in multiple pathways that are key to the development and activation of immune cells. Our previous work indicates that GPS2 (G-protein Pathway Suppressor 2) is a multifunctional protein regulating TNFα signaling and lipid metabolism in the adipose tissue through modulation of Lys63 ubiquitination events. However, the full extent of GPS2-mediated regulation of ubiquitination and the underlying molecular mechanisms are unknown. Here, we report that GPS2 is required for restricting the activation of TLR and BCR signaling pathways and the AKT/FOXO1 pathway in immune cells based on direct inhibition of Ubc13 enzymatic activity. Relevance of this regulatory strategy is confirmed in vivo by B cell-targeted deletion of GPS2, resulting in developmental defects at multiple stages of B cell differentiation. Together, these findings reveal that GPS2 genomic and non-genomic functions are critical for the development and cellular homeostasis of B cells.
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Affiliation(s)
| | - Anna C Belkina
- the Flow Cytometry Core Facility, Boston University School of Medicine, Boston, Massachusetts 02118 and.,Microbiology, and
| | | | | | | | | | | | | | | | - Jennifer Snyder-Cappione
- the Flow Cytometry Core Facility, Boston University School of Medicine, Boston, Massachusetts 02118 and.,Microbiology, and
| | - Bogdan Tanasa
- the Department of Pediatrics, Stanford University School of Medicine, Stanford, California 94305
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29
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Abstract
PURPOSE OF REVIEW Numerous lines of evidence support the likelihood that inflammation drives the transition from obese/metabolically healthy to obese/type 2 diabetes (T2D). Given the temporal flexibility of inflammation in obesity-associated T2D, investigators have hypothesized that a precipitous drop in diabetogenic cytokines is critical for rapid 'T2D remission' following surgery but prior to significant weight loss. We review the evidence that changes in diabetogenic cytokines play a role in outcomes of bariatric surgery, including improved glycemic control. RECENT FINDINGS A 2016 indication for bariatric surgery to treat T2D integrates the large body of data showing rapid metabolic improvement. Parameters that account for improved glycemic control prior to significant weight loss, T2D recidivism over the long term, or failure of surgery to remit T2D in some patients are incompletely understood. SUMMARY We review the evidence that changes in diabetogenic cytokines play a role in outcomes of bariatric surgery, including improved glycemic control. We brainstorm future research directions that may improve surgical results.
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Affiliation(s)
- Samar Hafida
- aSection of Endocrinology, Diabetes and Nutrition, Boston University School of Medicine, Boston, Massachusetts bWeis Center for Research; Geisinger Obesity Institute, Geisinger Clinic, Danville, Pennsylvania cDepartment of Microbiology; Department of Pathology; Department of Medicine; Department of Molecular and Cell Biology, Boston University School of Medicine, Boston, Massachusetts, USA
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30
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Nicholas D, Strissel KJ, Andrieu G, Tran AH, Nikolajczyk BS, Denis GV. The type 2 diabetes-associated Th17 cytokines IL-21 and IL-22 promote breast cancer cell survival. The Journal of Immunology 2016. [DOI: 10.4049/jimmunol.196.supp.124.56] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Abstract
Obesity-induced inflammation has taken center stage as a driving force in metabolic disease and type 2 diabetes (T2D). As the epidemic of obesity deepens, it has become imperative to dissect mechanisms by which obesity-induced inflammation contributes to increased cancer morbidity. Recent studies have shown that increased breast cancer mortality rates are associated with obesity-related T2D. Our goal is to understand the immunological mechanisms in T2D that contribute to increased breast cancer risk. We previously showed that PBMCs treated with T cell-targeted stimuli produce a pro-inflammatory Th17 cytokine profile that differentiates T2D from obese non-T2D subjects. We therefore tested the hypothesis that Th17 cytokines support breast cancer cells. Proliferation assays showed that IL-21 and IL-22, but not IL-17A/F, or the Th1 cytokine IL-6, maintained the proliferation of MCF7 cells, an estrogen dependent breast cancer cell line, in the absence of estrogen. Building on this result, we tested the effect of IL-21/22 on MCF7 survival. Immunoblots and mRNA arrays demonstrated that IL-21 but not IL-22 upregulated steady-state expression of BCL-2 family survival mRNA/protein. Both IL-21 and IL-22 survival was blocked by JQ1, an inhibitor of the Bromodomain and ExtraTerminal (BET) family of chromatin regulating proteins. The inferred cross-talk between BET- and Th17 cytokine-triggered pathways implicate the Th17 cytokine signature from PBMCs of patients with T2D in the higher recurrence of post-menopausal breast cancer after tamoxifen treatment. The public health impact of these data is that monitoring Th17 cytokine production by PBMCs may inform risk assessment for relapse or recurrence in breast cancer patients with T2D.
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31
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Affiliation(s)
- Dequina A. Nicholas
- Department of Microbiology, Boston, Massachusetts,
USA
- Department of Medicine, Boston University School of
Medicine, Boston, Massachusetts, USA
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32
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Ip B, Cilfone N, Belkina AC, DeFuria J, Jagannathan-Bogdan M, Zhu M, Kuchibhatla R, McDonnell ME, Xiao Q, Kepler TB, Apovian CM, Lauffenburger DA, Nikolajczyk BS. Th17 cytokines differentiate obesity from obesity-associated type 2 diabetes and promote TNFα production. Obesity (Silver Spring) 2016; 24:102-12. [PMID: 26576827 PMCID: PMC4688084 DOI: 10.1002/oby.21243] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Revised: 07/10/2015] [Accepted: 07/11/2015] [Indexed: 12/20/2022]
Abstract
OBJECTIVE T cell inflammation plays pivotal roles in obesity-associated type 2 diabetes (T2DM). The identification of dominant sources of T cell inflammation in humans remains a significant gap in understanding disease pathogenesis. It was hypothesized that cytokine profiles from circulating T cells identify T cell subsets and T cell cytokines that define T2DM-associated inflammation. METHODS Multiplex analyses were used to quantify T cell-associated cytokines in αCD3/αCD28-stimulated PBMCs, or B cell-depleted PBMCs, from subjects with T2DM or BMI-matched controls. Cytokine measurements were subjected to multivariate (principal component and partial least squares) analyses. Flow cytometry detected intracellular TNFα in multiple immune cell subsets in the presence/absence of antibodies that neutralize T cell cytokines. RESULTS T cell cytokines were generally higher in T2DM samples, but Th17 cytokines are specifically important for classifying individuals correctly as T2DM. Multivariate analyses indicated that B cells support Th17 inflammation in T2DM but not control samples, while monocytes supported Th17 inflammation regardless of T2DM status. Partial least squares regression analysis indicated that both Th17 and Th1 cytokines impact %HbA1c. CONCLUSIONS Among various T cell subsets, Th17 cells are major contributors to inflammation and hyperglycemia and are uniquely supported by B cells in obesity-associated T2DM.
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Affiliation(s)
- Blanche Ip
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | - Nicholas Cilfone
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA
| | - Anna C. Belkina
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | - Jason DeFuria
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | | | - Min Zhu
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | - Ramya Kuchibhatla
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | | | - Qiang Xiao
- EMD-Millipore, Biosciences Division, St. Charles, MO
| | - Thomas B. Kepler
- Department of Microbiology, Boston University School of Medicine, Boston MA
| | | | | | - Barbara S. Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston MA
- Department of Pathology, Boston University School of Medicine, Boston MA
- Department of Molecular and Cell Biology, Boston University School of Medicine, Boston MA
- Corresponding author 72 East Concord Street L516 Boston MA 02118 PH 617.638.7019 FAX 617.638.4286
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Zhu M, Nikolajczyk BS. Comment on "The B Cell-Stimulatory Cytokines BLyS and APRIL Are Elevated in Human Periodontitis and Are Required for B Cell-Dependent Bone Loss in Experimental Murine Periodontitis.". J Immunol 2015; 195:5099. [PMID: 26589743 DOI: 10.4049/jimmunol.1502059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Min Zhu
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118
| | - Barbara S Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston, MA 02118; Department of Pathology, Boston University School of Medicine, Boston, MA 02118; Department of Medicine, Boston University School of Medicine, Boston, MA 02118; and Department of Molecular and Cell Biology, Boston University School of Medicine, Boston, MA 02118
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Bucur O, Almasan A, Zubarev R, Friedman M, Nicolson GL, Sumazin P, Leabu M, Nikolajczyk BS, Avram D, Kunej T, Calin GA, Godwin AK, Adami HO, Zaphiropoulos PG, Richardson DR, Schmitt-Ulms G, Westerblad H, Keniry M, Grau GER, Carbonetto S, Stan RV, Popa-Wagner A, Takhar K, Baron BW, Galardy PJ, Yang F, Data D, Fadare O, Yeo KJ, Gabreanu GR, Andrei S, Soare GR, Nelson MA, Liehn EA. An updated h-index measures both the primary and total scientific output of a researcher. Discoveries (Craiova) 2015; 3. [PMID: 26504901 PMCID: PMC4617786 DOI: 10.15190/d.2015.42] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The growing interest in scientometry stems from ethical concerns related to the proper evaluation of scientific contributions of an author working in a hard science. In the absence of a consensus, institutions may use arbitrary methods for evaluating scientists for employment and promotion. There are several indices in use that attempt to establish the most appropriate and suggestive position of any scientist in the field he/she works in. A scientist's Hirsch-index (h-index) quantifies their total effective published output, but h-index summarizes the total value of their published work without regard to their contribution to each publication. Consequently, articles where the author was a primary contributor carry the same weight as articles where the author played a minor role. Thus, we propose an updated h-index named Hirsch(p,t)-index that informs about both total scientific output and output where the author played a primary role. Our measure, h(p,t) = h(p),h(t), is composed of the h-index h(t) and the h-index calculated for articles where the author was a key contributor; i.e. first/shared first or senior or corresponding author. Thus, a h(p,t) = 5,10 would mean that the author has 5 articles as first, shared first, senior or corresponding author with at least 5 citations each, and 10 total articles with at least 10 citations each. This index can be applied in biomedical disciplines and in all areas where the first and last position on an article are the most important. Although other indexes, such as r- and w-indexes, were proposed for measuring the authors output based on the position of researchers within the published articles, our simpler strategy uses the already established algorithms for h-index calculation and may be more practical to implement.
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Affiliation(s)
- Octavian Bucur
- Department of Pathology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Alex Almasan
- Department of Cancer Biology, Lerner Research Institute & Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Roman Zubarev
- Department of Medical Biochemistry & Biophysics, Karolinska Institutet, Stockholm, Sweden
| | - Mark Friedman
- Department of Pathology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center and Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Garth L Nicolson
- Department of Molecular Pathology, The Institute for Molecular Medicine, Huntington Beach, CA, USA
| | - Pavel Sumazin
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
| | - Mircea Leabu
- Department of Cellular and Molecular Medicine, University of Medicine and Pharmacy Carol Davila and Victor Babes National Institute of Pathology, Bucharest, Romania
| | | | - Dorina Avram
- Department of Medicine, Division of Pulmonary, Critical Care and Sleep Medicine, University of Florida, Gainesville, FL, USA
| | - Tanja Kunej
- Department of Genetics, Animal Biotechnology and Immunology, Domzale, Slovenia
| | - George A Calin
- Department of Experimental Therapeutics and Leukemia & Center for RNA Interference and Non-Coding RNAs, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Andrew K Godwin
- Department of Pathology and Laboratory Medicine, University of Kansas Cancer Center Kansas City, KS, USA
| | - Hans-Olov Adami
- Department of Medical Epidemiology and Biostatistics, Karolinska Institute, Stockholm, Sweden
| | | | - Des R Richardson
- Department of Pathology and Bosch Institute, University of Sydney, Sydney, Australia
| | - Gerold Schmitt-Ulms
- Department of Laboratory Medicine & Pathobiology, Tanz Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Canada
| | - Håkan Westerblad
- Department of Physiology and Pharmacology, Karolinska Institute, Stockholm, Sweden
| | - Megan Keniry
- Biology Department, University of TEXAS Pan American, Edinburg, TX, USA
| | - Georges E R Grau
- Department of Pathology, University of Sydney, Sydney, Australia
| | - Salvatore Carbonetto
- Centre for Research in Neuroscience, McGill University Health Sciences Centre, Montreal, Canada
| | - Radu V Stan
- The Geisel School of Medicine at Dartmouth, Dartmouth College, Lebanon, NH, USA
| | - Aurel Popa-Wagner
- Department of Psychiatry, Rostock University Medical School, Rostock, Germany
| | - Kasumov Takhar
- Department of Gastroenterology and Hepatology, Cleveland Clinic, Cleveland, OH, USA
| | - Beverly W Baron
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Paul J Galardy
- Pediatric Hematology/Oncology, Mayo Clinic Transplant Center, Mayo Clinic, Rochester, MI, USA
| | - Feng Yang
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Dipak Data
- Biochemistry Division, CSIR-Central Drug Research Institute, Lucknow, India
| | - Oluwole Fadare
- Department of Pathology, University of California, San Diego, San Diego, CA, USA
| | - Kt Jerry Yeo
- Department of Pathology, University of Chicago, Chicago, IL, USA
| | - Georgiana R Gabreanu
- Victor Babes National Institute of Pathology and Biomedical Sciences, Bucharest, Romania
| | - Stefan Andrei
- Service de Médecine Interne, CNHO des Quinze-Vingts, Paris, France
| | - Georgiana R Soare
- Departament of Obstetrics and Gynaecology, Bucharest University Emergency Hospital, Bucharest, Romania
| | - Mark A Nelson
- Department of Pathology, The University of Arizona, Tucson, AZ, USA
| | - Elisa A Liehn
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Aachen, Germany
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Abstract
Type 2 diabetes (T2D) is a metabolic disease associated with obesity-related insulin resistance (IR) and chronic inflammation. Animal studies indicate that IR can be caused and/or exacerbated by systemic and/or tissue-specific alterations in lymphocyte differentiation and function. Human studies also indicate that obesity-associated inflammation promotes IR. Nevertheless, clinical trials with anti-inflammatory therapies have yielded modest impacts on established T2D. Unlike mouse models, where obesity is predominantly associated with IR, 20-25% of obese humans are metabolically healthy with high insulin sensitivity. The uncoupling of obesity from IR in humans but not in animal models advocates for a more comprehensive understanding of mediators and mechanisms of human obesity-promoted IR, and better integration of knowledge from human studies into animal experiments to efficiently pursue T2D prevention and treatment.
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Affiliation(s)
- Blanche C Ip
- Department of Microbiology, Boston University, Boston, MA, USA
| | - Andrew E Hogan
- Obesity Immunology Group, Education and Research Centre, St Vincent's University Hospital, University College Dublin, Dublin, Ireland
| | - Barbara S Nikolajczyk
- Department of Microbiology, Boston University, Boston, MA, USA; Department of Medicine, Boston University, Boston, MA, USA.
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Abstract
PURPOSE OF REVIEW To summarize current work identifying inflammatory components that underlie associations between obesity-associated type 2 diabetes and coronary artery disease. RECENT FINDINGS Recent studies implicate immune cells as drivers of pathogenic inflammation in human type 2 diabetes. Inflammatory lymphocytes characterize unhealthy adipose tissue, but regional adipose volume, primarily visceral and pericardial fat, also predict severity and risk for obesity-associated coronary artery disease. Having a greater understanding of shared characteristics between inflammatory cells from different adipose tissue depots and a more accessible tissue, such as blood, will facilitate progress toward clinical translation of our appreciation of obesity as an inflammatory disease. SUMMARY Obesity predisposes inflammation and metabolic dysfunction through multiple mechanisms, but these mechanisms remain understudied in humans. Studies of obese patients have identified disproportionate impacts of specific T cell subsets in metabolic diseases like type 2 diabetes. On the basis of demonstration that adipose tissue inflammation is depot-specific, analysis of adiposity by waist-to-hip ratio or MRI will increase interpretive value of lymphocyte-focused studies and aid clinicians in determining which obese individuals are at highest risk for coronary artery disease. New tools to combat obesity-associated coronary artery disease and other comorbidities will stem from identification of immune cell-mediated inflammatory networks that are amenable to pharmacological interventions.
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Affiliation(s)
- Katherine J. Strissel
- Department of Medicine, Boston University School of Medicine, Boston MA, USA
- Cancer Research Center, Boston University School of Medicine, Boston MA, USA
| | - Gerald V. Denis
- Department of Medicine, Boston University School of Medicine, Boston MA, USA
- Cancer Research Center, Boston University School of Medicine, Boston MA, USA
| | - Barbara S. Nikolajczyk
- Department of Medicine, Boston University School of Medicine, Boston MA, USA
- Department of Microbiology, Boston University School of Medicine, Boston MA, USA
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Zhu M, Belkina AC, DeFuria J, Carr JD, Van Dyke TE, Gyurko R, Nikolajczyk BS. B cells promote obesity-associated periodontitis and oral pathogen-associated inflammation. J Leukoc Biol 2014; 96:349-57. [PMID: 24782490 DOI: 10.1189/jlb.4a0214-095r] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [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: 01/02/2023] Open
Abstract
Individuals with T2D and PD suffer significantly from the ability of one disease to intensify the other. Disease-associated inflammation is one mechanism thought to fuel this pathogenic feed-forward loop. Several lines of evidence indicate that proinflammatory B cells promote T2D and PD; thus, B cells are top candidates for a cell type that predisposes PD in T2D. To test directly the role of B cells in T2D-associated PD, we compared outcomes from oral Porphyromonas gingivalis challenge of lean WT or B cell-null mice with outcomes from mice that were obese and insulin-resistant before challenge. Obese WT mice responded to oral P. gingivalis challenge with significant periodontal bone loss, whereas obese B cell-null mice were protected completely from PD. By contrast, lean WT and B cell-null mice suffer similar periodontal bone loss in response to oral pathogen. B cells from obese/insulin-resistant hosts also support oral osteoclastogenesis and both oral and systemic production of inflammatory cytokines, including pro-osteoclastogenic TNF-α and MIP-2, an ortholog of human IL-8. B cells furthermore impact AT inflammation in obese, P. gingivalis-infected hosts. Taken together, these data show that fundamentally different mechanisms regulate PD in lean and obese hosts, with B cells able to promote PD only if the hosts are "primed" by obesity. These results justify more intense analysis of obesity-associated changes in B cells that predispose PD in human T2D.
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Affiliation(s)
- Min Zhu
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Anna C Belkina
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jason DeFuria
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Jordan D Carr
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA
| | - Thomas E Van Dyke
- Department of Applied Oral Sciences, The Forsyth Institute, Cambridge, Massachusetts, USA; and
| | - Robert Gyurko
- Department of Periodontology, Boston University Goldman School of Dental Medicine, Boston, Massachusetts, USA
| | - Barbara S Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, USA;
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38
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Abstract
The clinical association between obesity-associated type 2 diabetes (T2D) and periodontitis, coupled with the increasing prevalence of these diseases, justifies studies to identify mechanisms responsible for the vicious feed-forward loop between systemic and oral disease. Changes in the immune system are critical for both obesity-associated T2D and periodontitis and therefore may link these diseases. Recent studies at the intersection of immunology and metabolism have greatly advanced our understanding of the role the immune system plays in the transition between obesity and obesity-associated T2D and have shown that immune cells exhibit similar functional changes in obesity/T2D and periodontitis. Furthermore, myeloid and lymphoid cells likely synergize to promote obesity/T2D-associated periodontitis despite complexities introduced by disease interaction. Thus the groundwork is being laid for researchers to exploit existing models to understand immune cell dysfunction and break the devastating relationship between obesity-associated T2D and oral disease.
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Affiliation(s)
- M Zhu
- Department of Microbiology, Boston University School of Medicine, Boston, MA, USA
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39
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Bucur O, Almasan A, Nikolajczyk BS, Nicolson GL, Lawler J, Velculescu VE, Draghici S, Leabu M, Avram D, Bucur I, Calautti E, Calin GA, Chauhan SC, Ciubotaru M, Constantinescu SN, Datta D, Duda DG, Friedman MT, Galardy PJ, Harris BT, Huarte M, Khalil AM, Marchetti D, Movileanu L, Nat R, Nucera C, Popa-Wagner A, Stancu AL, Zhu S, Liehn EA. Discoveries: an innovative platform for publishing cutting-edge research discoveries in medicine, biology and chemistry. Discoveries (Craiova) 2013; 1:e1. [PMID: 32309535 PMCID: PMC6919543 DOI: 10.15190/d.2013.1] [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] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Discoveries is a new peer-reviewed, open access, online multidisciplinary and integrative journal publishing high impact reviews, experimental articles, perspective articles, and editorials from all areas related to medicine, biology, and chemistry, including but not limited to: Molecular and Cellular Biology, Biochemistry, Biophysics, Genomics, Proteomics, Biotechnology, Synthetic Biology, Bioengineering, Systems Biology, Bioinformatics, Translational Medicine, Medicine/ Clinical findings, Cognitive Science, Epidemiology, Global Medicine, Family Medicine, Organic/ Inorganic/ Physical Chemistry and Ethics in Science. Discoveries brings to the research community an outstanding editorial board that aims to address several of the innovations proposed above: there is no need to format the manuscript before submission, we have a rapid and efficient submission process, there is no need for a Cover Letter and we support the need for rules for validation of critical reagents, such as antibodies. Discoveries will aim to support high quality research on human subjects materials to provide relevance for non-human studies along with mechanistic insights into human biology and chemistry. We also aim to avoid requesting unnecessary experiments during the review process, without affecting the quality and conclusions of published manuscripts. In addition, we recognize the need of adopting the recommendations made by NCCD and other similar scientific guiding entities.
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Affiliation(s)
- Octavian Bucur
- Department of Pathology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Alexandru Almasan
- Department of Cancer Biology, Lerner Research Institute & Department of Radiation Oncology, Taussig Cancer Institute, Cleveland Clinic, Cleveland, Ohio, United States of America
| | | | - Garth L Nicolson
- The Institute for Molecular Medicine, Department of Molecular Pathology, Huntington Beach, CA, USA
| | - Jack Lawler
- Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Victor E Velculescu
- Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University, Baltimore, MD 21287
| | - Sorin Draghici
- Intelligent Systems and Bioinformatics Laboratory, Wayne State University, Detroit, MI, USA
| | - Mircea Leabu
- Department of Cellular and Molecular Medicine, University of Medicine and Pharmacy "Carol Davila" and "Victor Babes" National Institute of Pathology, Bucharest, Romania
| | - Dorina Avram
- Center for Cell Biology and Cancer Research & Center for Immunology and Microbial Disease, Albany Medical College, Albany, NY, USA
| | | | - Enzo Calautti
- Department of Molecular Biotechnology and Health Sciences, University of Turin, Turin, Italy
| | - George A Calin
- Department of Experimental Therapeutics and Leukemia & Center for RNA Interference and Non-Coding RNAs, University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Subhash C Chauhan
- Department of Pharmaceutical Sciences & Center for Cancer Research, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Mihai Ciubotaru
- Department of Immunobiology, Yale University School of Medicine, New Haven, CT, USA
| | - Stefan N Constantinescu
- de Duve Institute, Université Catholique de Louvain, Brussels, Belgium.,Ludwig Institute for Cancer Research, Brussels, Belgium
| | - Dipak Datta
- CSIR-Central Drug Research Institute, Biochemistry Division, Lucknow, UP, India
| | - Dan G Duda
- Steele Laboratory for Tumor Biology, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, USA
| | - Mark T Friedman
- Department of Pathology, St. Luke's-Roosevelt Hospital Center, Beth Israel Medical Center and Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Paul J Galardy
- Department of Biochemistry and Molecular Biology & Division of Pediatric Hematology/Oncology, Mayo Clinic, Rochester, MN, USA
| | - Brent T Harris
- Departments of Pathology and Neurology, Georgetown University Medical Center, Washington, DC, USA
| | - Maite Huarte
- Center for Applied Medical Research, University of Navarra, Pamplona, Spain
| | - Ahmad M Khalil
- Department of Genetics, Center for RNA Molecular Biology, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Dario Marchetti
- Departments of Molecular & Cellular Biology, Baylor College of Medicine, Houston, Texas, United States of America
| | - Liviu Movileanu
- Department of Physics, Structural Biology, Biochemistry, and Biophysics Program & Syracuse Biomaterials Institute, Syracuse University, Syracuse, NY, USA
| | - Roxana Nat
- Institute for Neuroscience, Medical University Innsbruck, Innsbruck, Austria
| | - Carmelo Nucera
- Human Thyroid Cancers Preclinical and Translational Research Laboratory, Experimental Division of Cancer Biology and Angiogenesis, Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA, USA
| | - Aurel Popa-Wagner
- Department of Psychiatry, Rostock University Medical School, Rostock, Germany
| | - Andreea L Stancu
- Department of Pathology, Harvard Medical School and Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - Shudong Zhu
- School of Biological Science and Technology, State Key Laboratory of Medical Genetics, Central South University, Changsha, China
| | - Elisa A Liehn
- Institute for Molecular Cardiovascular Research (IMCAR), RWTH Aachen University, Germany
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Belkina AC, Blanton WP, Nikolajczyk BS, Denis GV. The double bromodomain protein Brd2 promotes B cell expansion and mitogenesis. J Leukoc Biol 2013; 95:451-60. [PMID: 24319289 DOI: 10.1189/jlb.1112588] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bromodomain-containing transcriptional regulators represent new epigenetic targets in different hematologic malignancies. However, bromodomain-mediated mechanisms that couple histone acetylation to transcription in lymphopoiesis and govern mature lymphocyte mitogenesis are poorly understood. Brd2, a transcriptional coregulator that contains dual bromodomains and an extraterminal domain (the BET family), couples chromatin to cell-cycle progression. We reported previously the first functional characterization of a BET protein as an effector of mammalian mitogenic signal transduction: Eμ-Brd2 Tg mice develop "activated B cell" diffuse large B cell lymphoma. No other animal models exist for genetic or lentiviral expression of BET proteins, hampering testing of novel anti-BET anticancer drugs, such as JQ1. We transduced HSCs with Brd2 lentivirus and reconstituted recipient mice to test the hypothesis that Brd2 regulates hematopoiesis in BM and mitogenesis in the periphery. Forced expression of Brd2 provides an expansion advantage to the donor-derived B cell compartment in BM and increases mature B cell mitogenic responsiveness in vitro. Brd2 binds the cyclin A promoter in B cells, shown by ChIP, and increases cyclin A mRNA and protein levels, and S-phase progression in vitro in mitogen-stimulated primary B cells, but not T cells, reinforcing results from Eμ-Brd2 mice. The small molecule BET inhibitor JQ1 reduces B cell mitogenesis, consistent with the interpretation that BET inhibitors are antiproliferative. Brd2-specific knockdown experiments show that Brd2 is also required for hematopoiesis. We conclude that Brd2 plays a critical, independent role in regulation of mitogenic response genes, particularly cyclin A, in B cells.
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Affiliation(s)
- Anna C Belkina
- 1.72 East Concord St., Rm. K520, Boston, MA 02118, USA. ; Twitter: http://www.twitter.com/GdenisBoston
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41
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Abstract
Immunometabolism investigates the multiple links between the immune system and metabolism. One main focus of immunometabolism investigates how obesity impacts the immune system and pro-inflammatory immune cell function, leading to metabolic diseases, including type 2 diabetes (T2D). The second focus stresses the metabolic changes that dictate immune cell activation. Several groups have studied these two arms of the field individually, but work that integrates both topics will be required to develop an accurate understanding of how immune cells and metabolic pathways collaborate in obesity and obesity-associated T2D. Investigations of the relationships among obesity-induced changes in the nutritional environment, immune cell activation, and immune cell metabolism may lead to novel and efficacious therapies for obesity-associated disorders such as insulin resistance (IR) and T2D. This review outlines recent insights into two related processes: 1. the role that energy utilization plays in immune responses and 2. the immune cell functions that drive obesity and T2D. Herein, we begin to consider how shifts in available fuel sources in obesity and T2D impact the immune response to both pathogens and chronic over nutrition.
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Affiliation(s)
- Forum M Raval
- Boston University School of Medicine, Department of Microbiology, Boston, MA, USA
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Belkina AC, Nikolajczyk BS, Denis GV. BET protein function is required for inflammation: Brd2 genetic disruption and BET inhibitor JQ1 impair mouse macrophage inflammatory responses. J Immunol 2013; 190:3670-8. [PMID: 23420887 PMCID: PMC3608815 DOI: 10.4049/jimmunol.1202838] [Citation(s) in RCA: 315] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Histone acetylation regulates activation and repression of multiple inflammatory genes known to play critical roles in chronic inflammatory diseases. However, proteins responsible for translating the histone acetylation code into an orchestrated proinflammatory cytokine response remain poorly characterized. Bromodomain and extraterminal (BET) proteins are "readers" of histone acetylation marks, with demonstrated roles in gene transcription, but the ability of BET proteins to coordinate the response of inflammatory cytokine genes through translation of histone marks is unknown. We hypothesize that members of the BET family of dual bromodomain-containing transcriptional regulators directly control inflammatory genes. We examined the genetic model of brd2 lo mice, a BET protein hypomorph, to show that Brd2 is essential for proinflammatory cytokine production in macrophages. Studies that use small interfering RNA knockdown and a small-molecule inhibitor of BET protein binding, JQ1, independently demonstrate BET proteins are critical for macrophage inflammatory responses. Furthermore, we show that Brd2 and Brd4 physically associate with the promoters of inflammatory cytokine genes in macrophages. This association is absent in the presence of BET inhibition by JQ1. Finally, we demonstrate that JQ1 ablates cytokine production in vitro and blunts the "cytokine storm" in endotoxemic mice by reducing levels of IL-6 and TNF-α while rescuing mice from LPS-induced death. We propose that targeting BET proteins with small-molecule inhibitors will benefit hyperinflammatory conditions associated with high levels of cytokine production.
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Affiliation(s)
- Anna C. Belkina
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Barbara S. Nikolajczyk
- Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America
| | - Gerald V. Denis
- Cancer Research Center, Boston University School of Medicine, Boston, Massachusetts, United States of America
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Abstract
Obesity and Type 2 diabetes mellitus (T2D) are characterized by pro-inflammatory alterations in the immune system including shifts in leukocyte subset differentiation and in cytokine/chemokine balance. The chronic, low-grade inflammation resulting largely from changes in T-cell, B-cell, and myeloid compartments promotes and/or exacerbates insulin resistance (IR) that, together with pancreatic islet failure, defines T2D. Animal model studies show that interruption of immune cell-mediated inflammation by any one of several methods almost invariably results in the prevention or delay of obesity and/or IR. However, anti-inflammatory therapies have had a modest impact on established T2D in clinical trials. These seemingly contradictory results indicate that a more comprehensive understanding of human IR/T2D-associated immune cell function is needed to leverage animal studies into clinical treatments. Important outstanding analyses include identifying potential immunological checkpoints in disease etiology, detailing immune cell/adipose tissue cross-talk, and defining strengths/weaknesses of model organism studies to determine whether we can harness the promising new field of immunometabolism to curb the global obesity and T2D epidemics.
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45
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Jagannathan-Bogdan M, McDonnell ME, Shin H, Rehman Q, Hasturk H, Apovian CM, Nikolajczyk BS. Elevated proinflammatory cytokine production by a skewed T cell compartment requires monocytes and promotes inflammation in type 2 diabetes. J Immunol 2010; 186:1162-72. [PMID: 21169542 DOI: 10.4049/jimmunol.1002615] [Citation(s) in RCA: 285] [Impact Index Per Article: 20.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
An appropriate balance between proinflammatory (Th17 and Th1) and anti-inflammatory (regulatory T cells [Tregs] and Th2) subsets of T cells is critical to maintain homeostasis and avoid inflammatory disease. Type 2 diabetes (T2D) is a chronic inflammatory disease promoted by changes in immune cell function. Recent work indicates T cells are important mediators of inflammation in a mouse model of T2D. These studies identified an elevation in the Th17 and Th1 subsets with a decrease in the Treg subset, which culminates in inflammation and insulin resistance. Based on these data, we tested the hypothesis that T cells in T2D patients are skewed toward proinflammatory subsets. Our data show that blood from T2D patients has increased circulating Th17 cells and elevated activation of Th17 signature genes. Importantly, T cells required culture with monocytes to maintain Th17 signatures, and fresh ex vivo T cells from T2D patients appeared to be poised for IL-17 production. T cells from T2D patients also have increased production of IFN-γ, but produce healthy levels of IL-4. In contrast, T2D patients had decreased percentages of CD4(+) Tregs. These data indicate that T cells in T2D patients are naturally skewed toward proinflammatory subsets that likely promote chronic inflammation in T2D through elevated cytokine production. Potential therapies targeted toward resetting this balance need to be approached with caution due to the reciprocal relationship between Th17 cells and Tregs. Understanding the unique aspects of T2D T cells is essential to predict outcomes of such treatments.
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Ganley-Leal LM, Liang Y, Jagannathan-Bogdan M, Farraye FA, Nikolajczyk BS. Differential regulation of TLR4 expression in human B cells and monocytes. Mol Immunol 2010; 48:82-8. [PMID: 20956019 DOI: 10.1016/j.molimm.2010.09.008] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2010] [Revised: 08/30/2010] [Accepted: 09/06/2010] [Indexed: 12/22/2022]
Abstract
Toll-like receptor 4 (TLR4) is an innate immune receptor that is constitutively and inducibly activated in monocytes. Although TLR4 is expressed at very low levels on human B cells from healthy individuals, recent reports showed that TLR4 expression and function is elevated in B cells from inflammatory disease patients. New data showed that TLR4 expression on B cells is increased upon stimulation through surface Igμ and CD40 in combination with IL-4. In contrast, monocyte stimulation through CD40 and IL-4 receptors decreased TLR4 surface expression. Analysis of molecular signatures of TLR4 activation in stimulated B cells suggested that TLR4 is regulated by different mechanisms in B cells compared to monocytes. PU.1 and interferon regulatory factor association with the TLR4 promoter are sufficient for TLR4 transcription, but are not sufficient for surface TLR4 expression on B cells. In contrast, the PU.1/IRF combination is sufficient for surface TLR4 expression on monocytes. These data identify mechanisms that can activate B cell TLR4 expression in inflammatory disease patients, and demonstrate that B cells have additional layers of TLR4 regulation absent in monocytes.
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Affiliation(s)
- Lisa M Ganley-Leal
- Department of Medicine, Section of Infectious Diseases, Evans Biomedical Research Center, Boston Medical Center, Boston, MA 02118, USA
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Abstract
B lymphocytes play roles in many auto-immune diseases characterized by unresolved inflammation, and B cell ablation is proving to be a relatively safe, effective treatment for such diseases. B cells function, in part, as important sources of regulatory cytokines in auto-immune disease, but B cell cytokines also play roles in other non-auto-immune inflammatory diseases. B cell ablation may therefore benefit inflammatory disease patients in addition to its demonstrated efficacy in auto-immune disease. Current ablation drugs clear both pro- and anti-inflammatory B cell subsets, which may unexpectedly exacerbate some pathologies. This possibility argues that a more thorough understanding of B cell function in human inflammatory disease is required to safely harness the clinical promise of B cell ablation. Type 2 diabetes (T2D) and periodontal disease (PD) are two inflammatory diseases characterized by little autoimmunity. These diseases are linked by coincident presentation and alterations in toll-like receptor (TLR)-dependent B cell cytokine production, which may identify B cell ablation as a new therapy for co-affected individuals. Further analysis of the role B cells and B cell cytokines play in T2D, PD and other inflammatory diseases is required to justify testing B cell depletion therapies on a broader range of patients.
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Affiliation(s)
- Barbara S Nikolajczyk
- Departments of Microbiology and Medicine, Boston University School of Medicine, 72 East Concord Street, L-516, Boston, MA 02118, USA.
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48
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Denis GV, Nikolajczyk BS, Schnitzler GR. An emerging role for bromodomain-containing proteins in chromatin regulation and transcriptional control of adipogenesis. FEBS Lett 2010; 584:3260-8. [PMID: 20493850 DOI: 10.1016/j.febslet.2010.05.030] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2010] [Accepted: 05/16/2010] [Indexed: 12/11/2022]
Abstract
Transcriptional co-activators, co-repressors and chromatin remodeling machines are essential elements in the transcriptional programs directed by the master adipogenic transcription factor PPARgamma. Many of these components have orthologs in other organisms, where they play roles in development and pattern formation, suggesting new links between cell fate decision-making and adipogenesis. This review focuses on bromodomain-containing protein complexes recently shown to play a critical role in adipogenesis. Deeper understanding of these pathways is likely to have major impact on treatment of obesity-associated diseases, including metabolic syndrome, cardiovascular disease and Type 2 diabetes. The research effort is urgent because the obesity epidemic is serious; the medical community is ill prepared to cope with the anticipated excess morbidity and mortality associated with diet-induced obesity.
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Affiliation(s)
- Gerald V Denis
- Cancer Research Center, Department of Microbiology, Boston University School of Medicine, Boston, MA 02118, USA.
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Jagannathan M, Hasturk H, Liang Y, Shin H, Hetzel JT, Kantarci A, Rubin D, McDonnell ME, Van Dyke TE, Ganley-Leal LM, Nikolajczyk BS. TLR cross-talk specifically regulates cytokine production by B cells from chronic inflammatory disease patients. J Immunol 2009; 183:7461-70. [PMID: 19917698 DOI: 10.4049/jimmunol.0901517] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Chronic systemic inflammation links periodontal disease and diabetes to increased incidence of serious comorbidities. Activation of TLRs, particularly TLR2 and TLR4, promotes chronic systemic inflammation. Human B cells have been generally thought to lack these TLRs. However, recent work showed that an increased percentage of circulating B cells from inflammatory disease patients express TLR2 and TLR4, and that TLR engagement on B cells resulted in unexpected changes in gene expression. New data show that B cells from inflammatory disease patients secrete multiple cytokines in response to different classes of TLR ligands. Furthermore, the B cell response to combinations of TLR ligands is cytokine- and ligand-specific. Some cytokines (IL-1beta and IL-10) are predominantly regulated by TLR4, but others (IL-8 and TNF-alpha) are predominantly regulated by TLR2, due in part to TLR-dictated changes in transcription factor/promoter association. TLR2 and TLR9 also regulate B cell TLR4 expression, demonstrating that TLR cross-talk controls B cell responses at multiple levels. Parallel examination of B cells from periodontal disease and diabetes patients suggested that outcomes of TLR cross-talk are influenced by disease pathology. We conclude that disease-associated alteration of B cell TLR responses specifically regulates cytokine production and may influence chronic inflammation.
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Affiliation(s)
- Madhumita Jagannathan
- Department of Pathology, Boston University School of Medicine, Boston, MA 02118, USA
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Noronha AM, Liang Y, Hetzel JT, Hasturk H, Kantarci A, Stucchi A, Zhang Y, Nikolajczyk BS, Farraye FA, Ganley-Leal LM. Hyperactivated B cells in human inflammatory bowel disease. J Leukoc Biol 2009; 86:1007-16. [PMID: 19589946 DOI: 10.1189/jlb.0309203] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
IBD is characterized by a chronic, dysregulated immune response to intestinal bacteria. Past work has focused on the role of T cells and myeloid cells in mediating chronic gastrointestinal and systemic inflammation. Here, we show that circulating and tissue B cells from CD patients demonstrate elevated basal levels of activation. CD patient B cells express surface TLR2, spontaneously secrete high levels of IL-8, and contain increased ex vivo levels of phosphorylated signaling proteins. CD clinical activity correlates directly with B cell expression of IL-8 and TLR2, suggesting a positive relationship between these B cell inflammatory mediators and disease pathogenesis. In contrast, B cells from UC patients express TLR2 but generally do not demonstrate spontaneous IL-8 secretion; however, significant IL-8 production is inducible via TLR2 stimulation. Furthermore, UC clinical activity correlates inversely with levels of circulating TLR2+ B cells, which is opposite to the association observed in CD. In conclusion, TLR2+ B cells are associated with clinical measures of disease activity and differentially associated with CD- and UC-specific patterns of inflammatory mediators, suggesting a formerly unappreciated role of B cells in the pathogenesis of IBD.
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Affiliation(s)
- Ansu Mammen Noronha
- Section of Infectious Disease, Department of Medicine, Boston University School of Medicine, Boston, MA 02118, USA
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