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Abstract
Dipeptidyl peptidase IV (DPP-IV) is a unique serine protease that exists in a membrane bound state and in a soluble state in most tissues in the body. DPP-IV has multiple targets including cytokines, neuropeptides, and incretin hormones, and plays an important role in health and disease. Recent work suggests that skeletal muscle releases DPP-IV as a myokine and participates in control of muscle blood flow. However, few of the functions of DPP-IV as a myokine have been investigated to date and there is a poor understanding about what causes DPP-IV to be released from muscle.
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Affiliation(s)
- Heidi A Kluess
- School of Kinesiology, Auburn University, Auburn, AL, United States
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2
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Neidert LE, Al-Tarhuni M, Goldman D, Kluess HA, Jackson DN. Endogenous dipeptidyl peptidase IV modulates skeletal muscle arteriolar diameter in rats. Physiol Rep 2019; 6. [PMID: 29380955 PMCID: PMC5789721 DOI: 10.14814/phy2.13564] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 12/06/2017] [Accepted: 12/09/2017] [Indexed: 01/17/2023] Open
Abstract
The purpose of this study is to investigate that dipeptidyl peptidase IV (DPP‐IV) released from skeletal and vascular smooth muscle can increase arteriolar diameter in a skeletal muscle vascular bed by reducing neuropeptide Y (NPY)‐mediated vasoconstriction. We hypothesized that the effect of myokine DPP‐IV would be greatest in the smallest and least in the largest arterioles. Eight male Sprague Dawley rats (age 7–9 weeks; mass, mean ± SD: 258 ± 41 g) were anesthetized and the gluteus maximus dissected in situ for intravital microscopy analysis of arteriolar diameter of the vascular network. Computational modeling was performed on the diameter measurements to evaluate the overall impact of diameter changes on network resistance and flow distribution. In the first set of experiments, whey protein isolate powder was added to physiological saline solution, put in a heated reservoir, and applied to the preparation to induce release of DPP‐IV from the muscle. This resulted in an order‐dependent increase in arteriolar diameter, with the largest change in the 6A arterioles (63% more reactive than 1A arterioles; P < 0.05). This effect was abolished by adding the DPP‐IV inhibitor, Diprotin A. To test if the DPP‐IV released was affecting NPY‐mediated vasoconstriction, we applied NPY and whey protein, which resulted in attenuated vasoconstriction. These findings suggest that DPP‐IV is released from muscle and has a unique effect on blood flow, which appears to act on NPY to attenuate vasoconstriction. The findings suggest that DPP‐IV released from the skeletal or smooth muscle can alter muscle blood flow.
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Affiliation(s)
| | - Mohammed Al-Tarhuni
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Daniel Goldman
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
| | - Heidi A Kluess
- School of Kinesiology, Auburn University, Auburn, Alabama
| | - Dwayne N Jackson
- Department of Medical Biophysics, Schulich School of Medicine & Dentistry, The University of Western Ontario, London, Ontario, Canada
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Sittadjody S, Saul JM, McQuilling JP, Joo S, Register TC, Yoo JJ, Atala A, Opara EC. In vivo transplantation of 3D encapsulated ovarian constructs in rats corrects abnormalities of ovarian failure. Nat Commun 2017; 8:1858. [PMID: 29208899 PMCID: PMC5717171 DOI: 10.1038/s41467-017-01851-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 10/20/2017] [Indexed: 01/07/2023] Open
Abstract
Safe clinical hormone replacement (HR) will likely become increasingly important in the growing populations of aged women and cancer patients undergoing treatments that ablate the ovaries. Cell-based HRT (cHRT) is an alternative approach that may allow certain physiological outcomes to be achieved with lower circulating hormone levels than pharmacological means due to participation of cells in the hypothalamus-pituitary-ovary feedback control loop. Here we describe the in vivo performance of 3D bioengineered ovarian constructs that recapitulate native cell-cell interactions between ovarian granulosa and theca cells as an approach to cHRT. The constructs are fabricated using either Ca++ or Sr++ to crosslink alginate. Following implantation in ovariectomized (ovx) rats, the Sr++-cross-linked constructs achieve stable secretion of hormones during 90 days of study. Further, we show these constructs with isogeneic cells to be effective in ameliorating adverse effects of hormone deficiency, including bone health, uterine health, and body composition in this rat model.
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Affiliation(s)
- Sivanandane Sittadjody
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA
| | - Justin M Saul
- Department of Chemical, Paper and Biomedical Engineering, Miami University, Oxford, OH, 45056, USA
| | - John P McQuilling
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA
- School of Biomedical Engineering and Sciences (SBES), Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Sunyoung Joo
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA
| | - Thomas C Register
- Department of Pathology, Section on Comparative Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, 27157, USA
| | - James J Yoo
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA
- School of Biomedical Engineering and Sciences (SBES), Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Anthony Atala
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA
- School of Biomedical Engineering and Sciences (SBES), Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA
| | - Emmanuel C Opara
- Wake Forest Institute for Regenerative Medicine, Wake Forest School for Medicine, Winston-Salem, NC, 27157, USA.
- School of Biomedical Engineering and Sciences (SBES), Wake Forest School of Medicine, Winston-Salem, NC, 27157, USA.
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Al Tarhuni M, Goldman D, Jackson DN. ComprehensiveIn SituAnalysis of Arteriolar Network Geometry and Topology in Rat Gluteus Maximus Muscle. Microcirculation 2016; 23:456-67. [DOI: 10.1111/micc.12292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 06/24/2016] [Indexed: 01/10/2023]
Affiliation(s)
- Mohammed Al Tarhuni
- Department of Medical Biophysics; The University of Western Ontario; London Ontario Canada
| | - Daniel Goldman
- Department of Medical Biophysics; The University of Western Ontario; London Ontario Canada
- Biomedical Engineering Graduate Program; The University of Western Ontario; London Ontario Canada
| | - Dwayne N. Jackson
- Department of Medical Biophysics; The University of Western Ontario; London Ontario Canada
- Biomedical Engineering Graduate Program; The University of Western Ontario; London Ontario Canada
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Al-Khazraji BK, Saleem A, Goldman D, Jackson DN. From one generation to the next: a comprehensive account of sympathetic receptor control in branching arteriolar trees. J Physiol 2016; 593:3093-108. [PMID: 25952132 DOI: 10.1113/jp270490] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2015] [Accepted: 04/22/2015] [Indexed: 12/14/2022] Open
Abstract
The effect of the sympathetic nervous system on blood flow distribution within skeletal muscle microvasculature is conditional upon regional activation of receptors for sympathetic neurotransmitters. Previous studies have shown that proximal arterioles are largely governed by adrenergic activation, whereas it is speculated that distal branches are controlled by peptidergic and purinergic activation. However, no study has systematically evaluated the activation of adrenergic, peptidergic and purinergic receptors in continuously branching arteriolar trees of an individual skeletal muscle model. Therefore, in the present study, sympathetic agonists were used to evaluate the constriction responses along first to fifth order arterioles in continuously branching arteriolar trees of a in vivo rat gluteus maximus muscle preparation with respect to specific activation of receptors for sympathetic neurotransmitters (α1R, α2R, NPY1R and P2X1R). Constriction responses were incorporated into a mathematical blood flow model to estimate the total flow, resistance and red blood cell flow heterogeneity within a computationally reconstructed gluteus maximus arteriolar network. For the first time, the effects of activating receptors for sympathetic neurotransmitters on vasoconstrictor responses and the ensuing haemodynamics in continuously branching arteriolar trees of skeletal muscle were characterized, where proximal arterioles responded most to α1R and α2R adrenergic activation, whereas distal arterioles responded most to Y1R and P2X1R activation. Total flow and resistance changed with activation of all receptors, whereas red blood cell flow heterogeneity was largely affected by peptidergic and purinergic activation in distal arterioles. The reported data highlight the functional consequences of topologically-dependent sympathetic control and may serve as novel input parameters in computational modelling of network flow.
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Affiliation(s)
- Baraa K Al-Khazraji
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Amani Saleem
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada
| | - Daniel Goldman
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada.,Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario, Canada
| | - Dwayne N Jackson
- Department of Medical Biophysics, The University of Western Ontario, London, Ontario, Canada.,Biomedical Engineering Graduate Program, The University of Western Ontario, London, Ontario, Canada
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Shoemaker JK, Badrov MB, Al-Khazraji BK, Jackson DN. Neural Control of Vascular Function in Skeletal Muscle. Compr Physiol 2015; 6:303-29. [PMID: 26756634 DOI: 10.1002/cphy.c150004] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The sympathetic nervous system represents a fundamental homeostatic system that exerts considerable control over blood pressure and the distribution of blood flow. This process has been referred to as neurovascular control. Overall, the concept of neurovascular control includes the following elements: efferent postganglionic sympathetic nerve activity, neurotransmitter release, and the end organ response. Each of these elements reflects multiple levels of control that, in turn, affect complex patterns of change in vascular contractile state. Primarily, this review discusses several of these control layers that combine to produce the integrative physiology of reflex vascular control observed in skeletal muscle. Beginning with three reflexes that provide somewhat dissimilar vascular patterns of response despite similar changes in efferent sympathetic nerve activity, namely, the baroreflex, chemoreflex, and muscle metaboreflex, the article discusses the anatomical and physiological bases of postganglionic sympathetic discharge patterns and recruitment, neurotransmitter release and management, and details of regional variations of receptor density and responses within the microvascular bed. Challenges are addressed regarding the fundamentals of measurement and how conclusions from one response or vascular segment should not be used as an indication of neurovascular control as a generalized physiological dogma. Whereas the bulk of the article focuses on the vasoconstrictor function of sympathetic neurovascular integration, attention is also given to the issues of sympathetic vasodilation as well as the impact of chronic changes in sympathetic activation and innervation on vascular health. © 2016 American Physiological Society.
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Affiliation(s)
- J K Shoemaker
- School of Kinesiology, Western University, London, Ontario, Canada.,Department of Physiology and Pharmacology, Western University, London, Ontario, Canada
| | - M B Badrov
- School of Kinesiology, Western University, London, Ontario, Canada
| | - B K Al-Khazraji
- Department of Medical Biophysics, Western University, London, Ontario, Canada
| | - D N Jackson
- Department of Medical Biophysics, Western University, London, Ontario, Canada
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