Megan Marie Knuth

Dr. Megan Marie Knuth

UNC Chapel Hill
orcid

Research Focus & Metrics

Academic Career Length

8Years (2019-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 May 2019 in Journal of Endocrinology
Verified
Journal Article
Open access
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FIFolami Y Ideraabdullah
Folami Y Ideraabdullah
ABAnthony M Belenchia
Anthony M Belenchia
CRCheryl S Rosenfeld
Cheryl S Rosenfeld
SKSeth W Kullman
Seth W Kullman
Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
CPCatherine A Peterson
Catherine A Peterson
Vitamin D is an essential nutrient that is metabolized in the body to generate an active metabolite (1,25(OH)2D) with hormone-like activity and highly diverse roles in cellular function. Vitamin D deficiency (VDD) is a prevalent but easily preventable nutritional disturbance. Emerging evidence demonstrates the importance of sufficient vitamin D concentrations during fetal life with deficiencies leading to long-term effects into adulthood. Here, we provide a detailed review and perspective of evidence for the role of maternal VDD in offspring long-term health, particularly as it relates to developmental origins of health and disease (DOHaD). We focus on the roles in neurobehavioral and cardiometabolic disorders in humans and highlight recent findings from zebrafish and rodent models that probe potential mechanisms linking early life VDD to later life health outcomes. Moreover, we explore evidence implicating epigenetic mechanisms as a mediator of this link. Gaps in our current understanding of how maternal VDD might result in deleterious offspring outcomes later in life are also addressed.

4 March 2020 in Journal of the American Society for Mass Spectrometry
Verified
Journal Article
Closed access
WSWhitney L Stutts
Whitney L Stutts
Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
MEMåns Ekelöf
Måns Ekelöf
DMDebabrata Mahapatra
Debabrata Mahapatra
SKSeth William Kullman
Seth William Kullman
DMDavid Chalres Muddiman
David Chalres Muddiman

29 September 2020 in Scientific Reports
Verified
Journal Article
Open access
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Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
DMDebabrata Mahapatra
Debabrata Mahapatra
DJDereje Jima
Dereje Jima
DWDebin Wan
Debin Wan
BHBruce D. Hammock
Bruce D. Hammock
SKSeth Kullman
Seth Kullman
Emerging evidence demonstrates the importance of sufficient vitamin D (1α, 25-dihydroxyvitamin D3) levels during early life stage development with deficiencies associated with long-term effects into adulthood. While vitamin D has traditionally been associated with mineral ion homeostasis, accumulating evidence suggests non-calcemic roles for vitamin D including metabolic homeostasis. In this study, we examined the hypothesis that vitamin D deficiency (VDD) during early life stage development precedes metabolic disruption. Three dietary cohorts of zebrafish were placed on engineered diets including a standard laboratory control diet, a vitamin D null diet, and a vitamin D enriched diet. Zebrafish grown on a vitamin D null diet between 2–12 months post fertilization (mpf) exhibited diminished somatic growth and enhanced central adiposity associated with accumulation and enlargement of visceral and subcutaneous adipose depots indicative of both adipocyte hypertrophy and hyperplasia. VDD zebrafish exhibited elevated hepatic triglycerides, attenuated plasma free fatty acids and attenuated lipoprotein lipase activity consistent with hallmarks of dyslipidemia. VDD induced dysregulation of gene networks associated with growth hormone and insulin signaling, including induction of suppressor of cytokine signaling. These findings indicate that early developmental VDD impacts metabolic health by disrupting the balance between somatic growth and adipose accumulation.

18 October 2021 in Journal of Lipid Research
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Journal Article
Open access
Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
WSWhitney L Stutts
Whitney L Stutts
MRMorgan M. Ritter
Morgan M. Ritter
KGKenneth P. Garrard
Kenneth P. Garrard
SKSeth Kullman
Seth Kullman
Vitamin D is well known for its traditional role in bone mineral homeostasis; however, recent evidence suggests that vitamin D also plays a significant role in metabolic control. This study served to investigate putative linkages between vitamin D deficiency (VDD) and metabolic disruption of bioactive lipids by MS imaging. Our approach employed infrared-matrix-assisted laser desorption electrospray ionization MS imaging for lipid metabolite profiling in 6-month-old zebrafish fed either a VDD or a vitamin D-sufficient (VDS) diet. Using a lipidomics pipeline, we found that VDD zebrafish had a greater abundance of bioactive lipids (N-acyls, endocannabinoids [ECs], diacylglycerols/triacylglycerols, bile acids/bile alcohols, and vitamin D derivatives) suggestive of increased EC tone compared with VDS zebrafish. Tandem MS was performed on several differentially expressed metabolites with sufficient ion abundances to aid in structural elucidation and provide additional support for MS annotations. To confirm activation of the EC pathways, we subsequently examined expression of genes involved in EC biosynthesis, metabolism, and receptor signaling in adipose tissue and liver from VDD and VDS zebrafish. Gene expression changes were congruent with increased EC tone, with VDD zebrafish demonstrating increased synthesis and metabolism of anandamide compared with VDS zebrafish. Taken together, our data suggest that VDD may promote accumulation of bioactive lipids and increased EC tone in zebrafish.

20 February 2022 in Toxics
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Journal Article
Open access
PDF file
Chris KassotisChris Kassotis
Chris Kassotis
MLMatthew K. LeFauve
Matthew K. LeFauve
YCYu-Ting Tiffany Chiang
Yu-Ting Tiffany Chiang
Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
SSStacy Schkoda
Stacy Schkoda
SKSeth Kullman
Seth Kullman
Alkylphenol polyethoxylates (APEOs), such as nonylphenol ethoxylates (NPEOs), are high-production-volume surfactants used in laundry detergents, hard-surface cleaners, pesticide formulations, textile production, oils, paints, and other products. NPEOs comprise −80% of the total production of APEOs and are widely reported across diverse environmental matrices. Despite a growing push for replacement products, APEOs continue to be released into the environment through wastewater at significant levels. Research into related nonionic surfactants from varying sources has reported metabolic health impacts, and we have previously demonstrated that diverse APEOs and alcohol polyethoxylates promote adipogenesis in the murine 3T3-L1 pre-adipocyte model. These effects appeared to be independent of the base alkylphenol and related to the ethoxylate chain length, though limited research has evaluated NPEO exposures in animal models. The goals of this study were to assess the potential of NPEOs to promote adiposity (Nile red fluorescence quantification) and alter growth and/or development (toxicity, length, weight, and energy expenditure) of developmentally exposed zebrafish (Danio rerio). We also sought to expand our understanding of the ability to promote adiposity through evaluation in human mesenchymal stem cells. Herein, we demonstrated consistent adipogenic effects in two separate human bone-marrow-derived mesenchymal stem cell models, and that nonylphenol and its ethoxylates promoted weight gain and increased adipose deposition in developmentally exposed zebrafish. Notably, across both cell and zebrafish models we report increasing adipogenic/obesogenic activity with increasing ethoxylate chain lengths up to maximums around NPEO-6 and then decreasing activity with the longest ethoxylate chain lengths. This research suggests metabolic health concerns for these common obesogens, suggesting further need to assess molecular mechanisms and better characterize environmental concentrations for human health risk assessments.

17 June 2020 in Physiology & Behavior
Verified
Journal Article
Closed access
AOAnthony N Oliveri
Anthony N Oliveri
Megan Marie KnuthMegan Marie Knuth
Megan Marie Knuth
LGLilah Glazer
Lilah Glazer
JBJordan Bailey
Jordan Bailey
SKSeth W. Kullman
Seth W. Kullman
ELEdward D. Levin
Edward D. Levin