Christopher Gaffney

Dr. Christopher Gaffney

orcid

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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12 November 2020 in Annals of Surgery
Verified
Journal Article
Closed access
JLJoel E. Lambert
Joel E. Lambert
LHLawrence D. Hayes
Lawrence D. Hayes
TKThomas J. Keegan
Thomas J. Keegan
DSDaren A. Subar
Daren A. Subar
CGChristopher Gaffney
Christopher Gaffney
Objective: To determine the impact of prehabilitation on hospital length of stay, functional capacity, complications, and mortality after surgery in patients with hepatobiliary, colorectal, and upper gastrointestinal cancer. Background: “Prehabilitation” encompasses exercise, nutrition, and psychosocial interventions to optimize health before surgery. The benefits of prehabilitation are ill-defined. Methods: Medline, Embase and Cochrane Databases were searched systematically for the terms “prehabilitation AND exercise,” “perioperative care AND cancer surgery,” and “colorectal AND hepatobiliary AND hepatopancreatobiliary AND esophagogastric AND recovery AND outcomes.” Primary outcomes analyzed were hospital length of stay, functional capacity, significant postoperative complications (Clavien Dindo ≥ III), and mortality. A meta-analysis was conducted on the effect of all-modality prehabilitation for patients with colorectal, hepatopancreatobiliary and upper gastrointestinal cancer surgery using the raw mean difference, risk difference, and a random-effects model. Results: Three hundred and seventy seven original titles were identified. Fifteen studies (randomized controlled trials; n = 9 and uncontrolled trials; n = 6) were included in the meta-analysis. Prehabilitation reduced hospital length of stay by 1.78 days versus standard care (95% CI: −3.36, −0.20, P < 0.05). There was no significant difference in functional capacity with prehabilitation determined using the 6-minute walk test (P = 0.816) and no significant reduction in postoperative complications (P = 0.378) or mortality rates (P = 0.114). Conclusions: Prehabilitation was associated with reduced hospital length of stay but had no effect on functional capacity, postoperative complications, or mortality rates. Thus, prehabilitation should be recommended to accelerate recovery from cancer surgery, demonstrated by reduced hospital length of stay.

19 November 2018 in Aging
Verified
Journal Article
Closed access
CGChristopher Gaffney
Christopher Gaffney
APAmelia Pollard
Amelia Pollard
TBThomas F. Barratt
Thomas F. Barratt
DCDumitru Constantin-Teodosiu
Dumitru Constantin-Teodosiu
PGPaul L. Greenhaff
Paul L. Greenhaff
Nathaniel SzewczykNathaniel Szewczyk
Nathaniel Szewczyk
Sarcopenia, the age-related decline of muscle, is a significant and growing public health burden. C. elegans, a model organism for investigating the mechanisms of ageing, also displays sarcopenia, but the underlying mechanism(s) remain elusive. Here, we use C. elegans natural scaling of lifespan in response to temperature to examine the relationship between mitochondrial content, mitochondrial function, and sarcopenia. Mitochondrial content and maximal mitochondrial ATP production rates (MAPR) display an inverse relationship to lifespan, while onset of MAPR decline displays a direct relationship. Muscle mitochondrial structure, sarcomere structure, and movement decline also display a direct relationship with longevity. Notably, the decline in mitochondrial network structure occurs earlier than sarcomere decline, and correlates more strongly with loss of movement, and scales with lifespan. These results suggest that mitochondrial function is critical in the ageing process and more robustly explains the onset and progression of sarcopenia than loss of sarcomere structure.

4 August 2017 in The Journal of Clinical Endocrinology & Metabolism
Verified
Journal Article
Open access
PDF file
RSRicardo J Samms
Ricardo J Samms
JLJo Lewis
Jo Lewis
LNLuke Norton
Luke Norton
FSFrancis B Stephens
Francis B Stephens
CGChristopher Gaffney
Christopher Gaffney
KTKostas Tsintzas
Kostas Tsintzas
Context Fibroblast growth factor 21 (FGF21) secretion has been shown to respond directly to carbohydrate consumption, with glucose, fructose, and sucrose all reported to increase plasma levels of FGF21 in rodents and humans. However, carbohydrate consumption also results in secretion of insulin. Objective The aim of this study was to examine the combined and independent effects of hyperglycemia and hyperinsulinemia on total and bioactive FGF21 in the postprandial period in humans, and determine whether this effect is attenuated in conditions of altered insulin secretion and action. Methods Circulating glucose, insulin, total and bioactive FGF21, and fibroblast activation protein were measured in adults with and without type 2 diabetes (T2D) following an oral glucose tolerance test (OGTT), and under a series of insulin and glucose clamp conditions and following high-fat diet in healthy adults. Results Circulating total and bioactive FGF21 levels responded acutely to OGTT, and their ratio was attenuated in T2D patients with reduced postprandial insulin response. The clamp studies revealed that insulin but not glucose accounts for the postprandial rise in FGF21. Finally, there was an attenuated rise in FGF21 in response to a high-fat dietary intervention that is known to alter insulin-stimulated substrate utilization in metabolically active tissues. Conclusions Insulin rather than glucose per se increases total and bioactive FGF21 in the postprandial period in adult humans. Understanding the impact of T2D on bioactive FGF21 will have a significant effect upon the efficacy of therapeutic agents designed to target the FGF21 pathway.

10 January 2014 in Antioxidants & Redox Signaling
Verified
Journal Article
Open access
FMFernando Muñoz-Lobato
Fernando Muñoz-Lobato
MRMaría Jesús Rodríguez-Palero
María Jesús Rodríguez-Palero
FNFrancisco José Naranjo-Galindo
Francisco José Naranjo-Galindo
FSFreya Shephard
Freya Shephard
CGChristopher Gaffney
Christopher Gaffney
AMAntonio Miranda-Vizuete
Antonio Miranda-Vizuete
Aims: Cells have developed quality control systems for protection against proteotoxicity. Misfolded and aggregation-prone proteins, which are behind the initiation and progression of many neurodegenerative diseases (ND), are known to challenge the proteostasis network of the cells. We aimed to explore the role of DNJ-27/ERdj5, an endoplasmic reticulum (ER)-resident thioredoxin protein required as a disulfide reductase for the degradation of misfolded proteins, in well-established Caenorhabditis elegans models of Alzheimer, Parkinson and Huntington diseases. Results: We demonstrate that DNJ-27 is an ER luminal protein and that its expression is induced upon ER stress via IRE-1/XBP-1. When dnj-27 expression is downregulated by RNA interference we find an increase in the aggregation and associated pathological phenotypes (paralysis and motility impairment) caused by human β-amyloid peptide (Aβ), α-synuclein (α-syn) and polyglutamine (polyQ) proteins. In turn, DNJ-27 overexpression ameliorates these deleterious phenotypes. Surprisingly, despite being an ER-resident protein, we show that dnj-27 downregulation alters cytoplasmic protein homeostasis and causes mitochondrial fragmentation. We further demonstrate that DNJ-27 overexpression substantially protects against the mitochondrial fragmentation caused by human Aβ and α-syn peptides in these worm models. Innovation: We identify C. elegans dnj-27 as a novel protective gene for the toxicity associated with the expression of human Aβ, α-syn and polyQ proteins, implying a protective role of ERdj5 in Alzheimer, Parkinson and Huntington diseases. Conclusion: Our data support a scenario where the levels of DNJ-27/ERdj5 in the ER impact cytoplasmic protein homeostasis and the integrity of the mitochondrial network which might underlie its protective effects in models of proteotoxicity associated to human ND. Antioxid. Redox Signal. 20, 217–235.

1 December 2018 in Disease Models & Mechanisms
Verified
Journal Article
Open access
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JHJennifer E. Hewitt
Jennifer E. Hewitt
APAmelia K. Pollard
Amelia K. Pollard
LLLeila Lesanpezeshki
Leila Lesanpezeshki
Colleen Siobhan DeaneColleen Siobhan Deane
Colleen Siobhan Deane
CGChristopher Gaffney
Christopher Gaffney
SVSiva A. Valapalli
Siva A. Valapalli
Muscle strength is a key clinical parameter used to monitor the progression of human muscular dystrophies, including Duchenne and Becker muscular dystrophies. Although Caenorhabditis elegans is an established genetic model for studying the mechanisms and treatments of muscular dystrophies, analogous strength-based measurements in this disease model are lacking. Here, we describe the first demonstration of the direct measurement of muscular strength in dystrophin-deficient C. elegans mutants using a micropillar-based force measurement system called NemaFlex. We show that dys-1(eg33) mutants, but not dys-1(cx18) mutants, are significantly weaker than their wild-type counterparts in early adulthood, cannot thrash in liquid at wild-type rates, display mitochondrial network fragmentation in the body wall muscles, and have an abnormally high baseline mitochondrial respiration. Furthermore, treatment with prednisone, the standard treatment for muscular dystrophy in humans, and melatonin both improve muscular strength, thrashing rate and mitochondrial network integrity in dys-1(eg33), and prednisone treatment also returns baseline respiration to normal levels. Thus, our results demonstrate that the dys-1(eg33) strain is more clinically relevant than dys-1(cx18) for muscular dystrophy studies in C. elegans. This finding, in combination with the novel NemaFlex platform, can be used as an efficient workflow for identifying candidate compounds that can improve strength in the C. elegans muscular dystrophy model. Our study also lays the foundation for further probing of the mechanism of muscle function loss in dystrophin-deficient C. elegans, leading to knowledge translatable to human muscular dystrophy. This article has an associated First Person interview with the first author of the paper.

9 December 2014 in The FASEB Journal
Verified
Journal Article
Open access
PDF file
TETimothy Etheridge
Timothy Etheridge
MRMizanur Rahman
Mizanur Rahman
CGChristopher Gaffney
Christopher Gaffney
DSDebra Shaw
Debra Shaw
FSFreya Shephard
Freya Shephard
Nathaniel SzewczykNathaniel Szewczyk
Nathaniel Szewczyk
The integrin‐adhesome network, which contains >150 proteins, is mechano‐transducing and located at discreet positions along the cell‐cell and cell‐extracellular matrix interface. A small subset of the integrin‐adhesome is known to maintain normal muscle morphology. However, the importance of the entire adhesome for muscle structure and function is unknown. We used RNA interference to knock down 113 putative Caenorhabditis elegans homologs constituting most of the mammalian adhesome and 48 proteins known to localize to attachment sites in C. elegans muscle. In both cases, we found >90% of components were required for normal muscle mitochondrial structure and/or proteostasis vs. empty vector controls. Approximately half of these, mainly proteins that physically interact with each other, were also required for normal sarcomere and/or adhesome structure. Next we confirmed that the dystrophy observed in adhesome mutants associates with impaired maximal mitochondrial ATP production ( P < 0.01), as well as reduced probability distribution of muscle movement forces compared with wild‐type animals. Our results show that the integrin‐adhesome network as a whole is required for maintaining both muscle structure and function and extend the current understanding of the full complexities of the functional adhesome in vivo. —Etheridge, T., Rahman, M., Gaffney, C. J., Shaw, D., Shephard, F., Magudia, J., Solomon, D. E., Milne, T., Blawzdziewicz, J., Constantin‐Teodosiu, D., Greenhaff, P. L., Vanapalli, S. A., Szewczyk, N. J. The integrin‐adhesome is required to maintain muscle structure, mitochondrial ATP production, and movement forces in Caenorhabditis elegans. FASEB J. 29, 1235‐1246 (2015). www.fasebj.org