1
|
Dombrecht D, Van Daele U, Van Asbroeck B, Schieffelers D, Guns PJ, Gebruers N, Meirte J, van Breda E. Molecular mechanisms of post-burn muscle wasting and the therapeutic potential of physical exercise. J Cachexia Sarcopenia Muscle 2023; 14:758-770. [PMID: 36760077 PMCID: PMC10067483 DOI: 10.1002/jcsm.13188] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/16/2022] [Revised: 01/03/2023] [Accepted: 01/16/2023] [Indexed: 02/11/2023] Open
Abstract
After a severe burn injury, a systemic stress response activates metabolic and inflammatory derangements that, among other, leads to muscle mass loss (muscle wasting). These negative effects on skeletal muscle continue for several months or years and are aggravated by short-term and long-term disuse. The dynamic balance between muscle protein synthesis and muscle protein breakdown (proteolysis) is regulated by complex signalling pathways that leads to an overall negative protein balance in skeletal muscle after a burn injury. Research concerning these molecular mechanisms is still scarce and inconclusive, understanding of which, if any, molecular mechanisms contribute to muscle wasting is of fundamental importance in designing of therapeutic interventions for burn patients as well. This review not only summarizes our present knowledge of the molecular mechanisms that underpin muscle protein balance but also summarizes the effects of exercise on muscle wasting post-burn as promising strategy to counteract the detrimental effects on skeletal muscle. Future research focusing on the pathways causing post-burn muscle wasting and the different effects of exercise on them is needed to confirm this hypothesis and to lay the foundation of therapeutic strategies.
Collapse
Affiliation(s)
- Dorien Dombrecht
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium
| | - Ulrike Van Daele
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium.,Oscare, Organisation for Burns, Scar After-Care and Research, Antwerp, Belgium
| | - Birgit Van Asbroeck
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium
| | - David Schieffelers
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium
| | - Pieter-Jan Guns
- Laboratory of Physiopharmacology, University of Antwerp, Antwerp, Belgium
| | - Nick Gebruers
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium.,Multidisciplinary Edema Clinic, Antwerp University Hospital, Edegem, Belgium
| | - Jill Meirte
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium.,Oscare, Organisation for Burns, Scar After-Care and Research, Antwerp, Belgium
| | - Eric van Breda
- Department of Rehabilitation Sciences & Physiotherapy, Research group MOVANT, Multidisciplinary Metabolic Research Unit (M2RUN), University of Antwerp, Antwerp, Belgium
| |
Collapse
|
2
|
Quintana HT, Baptista VIDA, Lazzarin MC, Antunes HKM, Le Sueur-Maluf L, de Oliveira CAM, de Oliveira F. Insulin Modulates Myogenesis and Muscle Atrophy Resulting From Skin Scald Burn in Young Male Rats. J Surg Res 2020; 257:56-68. [PMID: 32818785 DOI: 10.1016/j.jss.2020.07.040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 06/18/2020] [Accepted: 07/07/2020] [Indexed: 10/23/2022]
Abstract
BACKGROUND Burn injuries (BIs) due to scalding are one of the most common accidents among children. BIs greater than 40% of total body surface area are considered extensive and result in local and systemic response. We sought to assess morphological and myogenic mechanisms through both short- and long-term intensive insulin therapies that affect the skeletal muscle after extensive skin BI in young rats. MATERIALS AND METHODS Wistar rats aged 21 d were distributed into four groups: control (C), control with insulin (C + I), scald burn injury (SI), and SI with insulin (SI + I). The SI groups were submitted to a 45% total body surface area burn, and the C + I and SI + I groups received insulin (5 UI/Kg/d) for 4 or 14 d. Glucose tolerance and the homeostatic model assessment of insulin resistance index were determined. Gastrocnemius muscles were analyzed for histopathological, morphometric, and immunohistochemical myogenic parameters (Pax7, MyoD, and MyoG); in addition, the expression of genes related to muscle atrophy (MuRF1 and MAFbx) and its regulation (IGF-1) were also assessed. RESULTS Short-term treatment with insulin favored muscle regeneration by primary myogenesis and decreased muscle atrophy in animals with BIs, whereas the long-term treatment modulated myogenesis by increasing the MyoD protein. Both treatments improved histopathological parameters and secondary myogenesis by increasing the MyoG protein. CONCLUSIONS Treatment with insulin benefits myogenic parameters during regeneration and modulates MuRF1, an important mediator of muscle atrophy.
Collapse
Affiliation(s)
| | | | | | | | | | | | - Flavia de Oliveira
- Departamento de Biociências, Universidade Federal de São Paulo, Santos, SP, Brazil.
| |
Collapse
|
3
|
Aijaz A, Teryek M, Goedken M, Polunas M, Olabisi RM. Coencapsulation of ISCs and MSCs Enhances Viability and Function of both Cell Types for Improved Wound Healing. Cell Mol Bioeng 2019; 12:481-493. [PMID: 31719928 PMCID: PMC6816714 DOI: 10.1007/s12195-019-00582-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2019] [Accepted: 06/21/2019] [Indexed: 12/13/2022] Open
Abstract
Introduction We previously demonstrated that insulin secreting cells (ISCs) accelerate healing of chronic wounds, and it is known that mesenchymal stem cells (MSCs) also accelerate wound healing. Here, we report that the combination of both cell types coencapsulated into a synthetic hydrogel dressing accelerates chronic wound healing 3 × faster than control and 2 × faster than each cell type delivered singly. Specifically, insulin released by ISCs activates the PI3/Akt pathway, which is vital to the function and survival of MSCs. MSCs in turn improve the viability and function of ISCs. Materials and Methods MSCs and/or rat islet tumor RIN-m cells were encapsulated into polyethylene glycol diacrylate hydrogel sheets and applied to 1 cm2 full thickness excisional wounds on the dorsa of genetically diabetic male mice (BKS.Cg-m +/+Leprdb/J) in accordance with protocols approved by the Rutgers IACUC. Encapsulated cell viability was assessed using a LIVE/DEAD® Viability/Cytotoxicity Kit. Akt phosphorylation, insulin, VEGF, and TGF-β1 secretion were assessed by ELISA. Animals were sacrificed on postoperative days 14 and 28 and wound tissue was collected for histological and western blot analysis. Results ISC:MSC combination groups had the highest levels of every secreted product and phosphorylated Akt, and closed wounds in 14 days, ISC-only or MSC-only groups closed wounds in 28 days, control groups closed wounds in 40 days. Further, ISC:MSC groups healed without intermediate scab or scar. Conclusions Combining MSCs with ISCs results in a more robust healing response than singly delivered cells, warranting further investigation of coencapsulation for MSC therapies.
Collapse
Affiliation(s)
- Ayesha Aijaz
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854 USA
| | - Matthew Teryek
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854 USA
| | - Michael Goedken
- Research Pathology Services, Rutgers University, Piscataway, NJ 08854 USA
| | - Marianne Polunas
- Research Pathology Services, Rutgers University, Piscataway, NJ 08854 USA
| | - Ronke M Olabisi
- Department of Biomedical Engineering, Rutgers University, 599 Taylor Road, Piscataway, NJ 08854 USA
| |
Collapse
|
4
|
Baptista VIDA, Quintana HT, Lazzarin MC, Benfato ID, De Carvalho FP, Le Sueur-Maluf L, De Oliveira CAM, Baptista JDS, De Oliveira F. Short time insulin treatment post burn improves elastic-collagen rearrangement and reepithelization. Connect Tissue Res 2019; 60:230-239. [PMID: 29929404 DOI: 10.1080/03008207.2018.1484916] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Extensive burn may cause acute resistance to insulin, which accentuates hypermetabolism, impairs glucose metabolism, immune dysfunction and risks of sepsis. To minimize these effects, insulin is used as a treatment. The purpose was to analyze the collagen-elastic arrangement effects of insulin on the burned skin. Wistar rats were assigned in groups: control (C); control with insulin (C + I); scald burn injury (SBI); and SBI with insulin (SBI+ I). SBI were submitted to 45% total body surface area burn and the insulin-treated groups received insulin (5 UI/Kg/day) for 4 or 14 days (d). Insulin levels, glucose tolerance test and HOMA index were determined. The skin sections were analyzed for histophatological and morphoquantitative data. Histopathological findings showed increased reepithelization of SBI+ I and formation of a new muscle layer after 14 days. In the collagen-elastic arrangement, insulin for 4 days increased the volume fraction (Vv) of thin collagen and elastic fibers. After 14 days, independently of injury, insulin decreased the elastic fibers. Insulin was able to reverse damages in the collagen-elastic rearrangement and stimulate reepithelization after 4 days. Untreated scald-burned animals showed higher Vv of thick collagen after 4 days, while those treated had a higher Vv of thin collagen. The Vv of elastic fibers was increased in SBI+ I for 4 days. In conclusion, insulin treatment was able to stimulate reepithelization. It also reversed the damages to the collagen-elastic arrangement in the scald-burned group, improving the organization of thin collagen and increasing the Vv of elastic fibers in the injured group treated with insulin for a short time, that is, for 4 days.
Collapse
Affiliation(s)
| | | | - Mariana Cruz Lazzarin
- a Department of Biosciences , Federal University of São Paulo, UNIFESP , SP , Brazil
| | - Izabelle Dias Benfato
- a Department of Biosciences , Federal University of São Paulo, UNIFESP , SP , Brazil
| | | | | | | | | | - Flavia De Oliveira
- a Department of Biosciences , Federal University of São Paulo, UNIFESP , SP , Brazil
| |
Collapse
|
5
|
Tight Glycemic Control With Insulin Does Not Affect Skeletal Muscle Degradation During the Early Postoperative Period Following Pediatric Cardiac Surgery. Pediatr Crit Care Med 2015; 16:515-21. [PMID: 25850865 PMCID: PMC4497866 DOI: 10.1097/pcc.0000000000000413] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
OBJECTIVE Critical illness is associated with significant catabolism, and persistent protein loss correlates with increased morbidity and mortality. Insulin is a potent anticatabolic hormone; high-dose insulin decreases skeletal muscle protein breakdown in critically ill pediatric surgical patients. However, insulin's effect on protein catabolism when given at clinically utilized doses has not been studied. The objective was to evaluate the effect of postoperative tight glycemic control and clinically dosed insulin on skeletal muscle degradation in children after cardiac surgery with cardiopulmonary bypass. DESIGN Secondary analysis of a two-center, prospective randomized trial comparing tight glycemic control with standard care. Randomization was stratified by study center. PATIENTS Children 0-36 months who were admitted to the ICU after cardiac surgery requiring cardiopulmonary bypass. INTERVENTIONS In the tight glycemic control arm, insulin was titrated to maintain blood glucose between 80 and 110 mg/dL. Patients in the control arm received standard care. Skeletal muscle breakdown was quantified by a ratio of urinary 3-methylhistidine to urinary creatinine. MEASUREMENTS AND MAIN RESULTS A total of 561 patients were included: 281 in the tight glycemic control arm and 280 receiving standard care. There was no difference in 3-methylhistidine to creatinine between groups (tight glycemic control, 249 ± 127 vs standard care, 253 ± 112, mean ± SD in μmol/g; p = 0.72). In analyses restricted to the patients in tight glycemic control arm, higher 3-methylhistidine to creatinine correlated with younger age, as well as lower weight, weight-for-age z score, length, and body surface area (p < 0.005 for each) and lower postoperative day 3 serum creatinine (r = -0.17; p = 0.02). Sex, prealbumin, and albumin were not associated with 3-methylhistidine to creatinine. During urine collection, 245 patients (87%) received insulin. However, any insulin exposure did not impact 3-methylhistidine to creatinine (t test, p = 0.45), and there was no dose-dependent effect of insulin on 3-methylhistidine to creatinine (r = -0.03; p = 0.60). CONCLUSION Although high-dose insulin has an anabolic effect in experimental conditions, at doses necessary to achieve normoglycemia, insulin appears to have no discernible impact on skeletal muscle degradation in critically ill pediatric cardiac surgical patients.
Collapse
|
6
|
Duan K, Yu W, Lin Z, Tan S, Bai X, Gao T, Xi F, Li N. Insulin ameliorating endotoxaemia-induced muscle wasting is associated with the alteration of hypothalamic neuropeptides and inflammation in rats. Clin Endocrinol (Oxf) 2015; 82:695-703. [PMID: 25204980 DOI: 10.1111/cen.12610] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Revised: 07/22/2014] [Accepted: 09/03/2014] [Indexed: 01/04/2023]
Abstract
OBJECTIVES Septic patients always develop muscle wasting, which delays the rehabilitation and contributes to the increased complications and mortality. Previous studies have implied the crucial role of central inflammation and neuropeptides in the energy balance and muscle metabolism. Insulin has been confirmed to attenuate muscle degradation and inhibit inflammation. We tested the hypothesis whether insulin ameliorating muscle wasting was associated with modulating hypothalamic inflammation and neuropeptides. DESIGN AND SUBJECTS Thirty-two adult male Sprague-Dawley rats were in intraperitoneally injected with lipopolysaccharide (LPS) (5 mg/kg) or saline, followed by subcutaneous injection of insulin (5 IU/kg) or saline. Twenty-four hours after injection, skeletal muscle and hypothalamus tissues were harvested. Muscle wasting was measured by the mRNA expression of two E3 ubiquitin ligases, muscle ring finger 1 (MuRF-1) and muscle atrophy F-box (MAFbx), as well as 3-methylhistidine (3-MH) and tyrosine release. Hypothalamic inflammatory markers and neuropeptides expression were also measured in four groups. RESULTS LPS injection led to significant increase in hypothalamic inflammation as well as muscle wasting. Also, increased hypothalamic neuropeptides, proopiomelanocortin (POMC), cocaine and amphetamine-related transcript (CART) and neuropeptides Y (NPY) and decreased agouti-related protein (AgRP) were observed. Insulin treatment ameliorated endotoxaemia-induced muscle wasting and hypothalamic inflammation, and attenuated the alteration of neuropeptides, POMC, CART and AgRP. CONCLUSION Hypothalamic inflammation and neuropeptides are involved in the endotoxaemia-induced muscle wasting. Insulin treatment can reduce muscle wasting, which is associated with reduced hypothalamic inflammation and alteration of hypothalamic neuropeptides.
Collapse
Affiliation(s)
- Kaipeng Duan
- Department of General Surgery, Jinling hospital, Medical School of Nanjing University, Nanjing, China
| | | | | | | | | | | | | | | |
Collapse
|
7
|
Chen Q, Li N, Zhu W, Li W, Tang S, Yu W, Gao T, Zhang J, Li J. Insulin alleviates degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system in septic rats. JOURNAL OF INFLAMMATION-LONDON 2011; 8:13. [PMID: 21639905 PMCID: PMC3120636 DOI: 10.1186/1476-9255-8-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2010] [Accepted: 06/03/2011] [Indexed: 01/03/2023]
Abstract
Hypercatabolism is common under septic conditions. Skeletal muscle is the main target organ for hypercatabolism, and this phenomenon is a vital factor in the deterioration of recovery in septic patients. In skeletal muscle, activation of the ubiquitin-proteasome system plays an important role in hypercatabolism under septic status. Insulin is a vital anticatabolic hormone and previous evidence suggests that insulin administration inhibits various steps in the ubiquitin-proteasome system. However, whether insulin can alleviate the degradation of skeletal muscle protein by inhibiting the ubiquitin-proteasome system under septic condition is unclear. This paper confirmed that mRNA and protein levels of the ubiquitin-proteasome system were upregulated and molecular markers of skeletal muscle proteolysis (tyrosine and 3-methylhistidine) simultaneously increased in the skeletal muscle of septic rats. Septic rats were infused with insulin at a constant rate of 2.4 mU.kg-1.min-1 for 8 hours. Concentrations of mRNA and proteins of the ubiquitin-proteasome system and molecular markers of skeletal muscle proteolysis were mildly affected. When the insulin infusion dose increased to 4.8 mU.kg-1.min-1, mRNA for ubiquitin, E2-14 KDa, and the C2 subunit were all sharply downregulated. At the same time, the levels of ubiquitinated proteins, E2-14KDa, and the C2 subunit protein were significantly reduced. Tyrosine and 3-methylhistidine decreased significantly. We concluded that the ubiquitin-proteasome system is important skeletal muscle hypercatabolism in septic rats. Infusion of insulin can reverse the detrimental metabolism of skeletal muscle by inhibiting the ubiquitin-proteasome system, and the effect is proportional to the insulin infusion dose.
Collapse
Affiliation(s)
- Qiyi Chen
- Department of General Surgery, Jinling Hospital, Medical College of Nanjing University, Nanjing 210002, Jiangsu Province, China.
| | | | | | | | | | | | | | | | | |
Collapse
|
8
|
Claeyssen R, Andriollo-Sanchez M, Arnaud J, Touvard L, Alonso A, Chancerelle Y, Roussel AM, Agay D. Effect of sub-deficient zinc status on insulin sensitivity after burn injury in rats. Biol Trace Elem Res 2009; 127:132-42. [PMID: 18800198 DOI: 10.1007/s12011-008-8226-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 06/26/2008] [Indexed: 12/13/2022]
Abstract
Although zinc status is an important parameter in insulin sensitivity, data concerning its implication in noxious burn-induced insulin resistance are scarce. The present study was designed to evaluate the impact of zinc status before burn on the recovery of injury with focus on plasma insulin and glucose levels. The experiment was performed in male adult Wistar rats fed from weaning with a zinc normal diet (80 ppm) or a depleted zinc diet (10 ppm) for 8 weeks and burned to third degree on 20% of their total body surface area. Blood and tissue samples were collected 3, 6, and 24 h after injury in order to study biochemical parameters and the glucose/insulin response in relation with the zinc status. After burn, zinc-depleted rats presented an exacerbated decrease in plasma zinc level. In addition, the burn-induced insulin resistance, leading to protein catabolism, was emphasized, with higher plasma insulin, glucose, and leptin levels in zinc-deficient animals versus normal-fed rats. Our experimental results underlined the interest to early control the zinc status in order to limit the deleterious effects of oxidative stress and insulin resistance in burned patients.
Collapse
Affiliation(s)
- Richard Claeyssen
- Centre de Recherches du Service de Santé des Armées, 24 Avenue des Maquis du Grésivaudan, BP 87, 38702, La Tronche cedex, France
| | | | | | | | | | | | | | | |
Collapse
|
9
|
Abstract
Pharmacologic modulation of hypermetabolism clearly benefits children with major burns, however, its role in adult burns remains to be defined. Oxandrolone appears to be a promising anabolic agent although few outcome data are as yet available. We examined whether early oxandrolone treatment in severely burned adults was associated with improved outcomes during acute hospitalization. We evaluated for potential associations between oxandrolone treatment and outcomes in a large cohort of severely burned adults in the context of a multicenter observational study. Patients were dichotomized with respect to oxandrolone treatment, defined as administration within 7 days after admission, with duration of at least 7 days. Acute hospitalization outcomes were compared with univariate and multivariate analyses. One hundred seventeen patients were included in this analysis. Mean patient age was 42.6 years (range, 18-86); 77% were male, with an average TBSA of 44.1%. Baseline and injury characteristics were similar among treatment and nontreatment cohorts. Oxandrolone treatment (N = 59) did not impact length of stay but was associated with a lower mortality rate (P = .01) by univariate analysis. Oxandrolone treatment was independently associated with higher survival by adjusted analyses (P = .02). Examination of early oxandrolone treatment in this cohort of severely burned adults suggests that this therapy is safe and may be associated with improved survival. Further studies are necessary to define the exact mechanisms by which oxandrolone is beneficial during inpatient treatment.
Collapse
|
10
|
Emanuele MA, Emanuele NV, Gamelli RL, Kovacs EJ, LaPaglia N. Effects of Insulin on Hepatic Inflammation Induced by Ethanol and Burn Injury in a Murine Model of Critical Illness. J Burn Care Res 2007; 28:490-9. [PMID: 17438481 DOI: 10.1097/bcr.0b013e318053daed] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
In recent, landmark clinical trials, insulin to maintain euglycemia in critically ill patients improved clinical outcomes, including decreased all-cause mortality. Novel antiinflammatory effects of insulin have recently been described. Thermal injury is an excellent model of critical illness. The addition of ethanol to the model is of great clinical relevance because nearly 50% of the patients admitted to hospitals for burn injuries have ethanol in their circulation. Utilizing a murine model of critical illness (ethanol and skin burn), we tested the hypothesis that insulin treatment in ethanol-exposed, burn-injured mice reduced hepatic inflammation, a potential mechanism for the benefit of insulin. Adult male C57BL/6 mice were given a single intraperitoneal injection of ethanol or saline, were given a 15% total body full-thickness skin burn, or were sham-burned and killed 24 hours later. In each group, half the animals were given subcutaneous injections of the long-lasting basal insulin glargine; the other half, the appropriate vehicle. Hepatic inflammatory markers, including polymorphonuclear infiltration, a chemokine, an important adhesion molecule, proinflammatory cytokines, and nuclear factor kappaB, were measured, and all were increased by ethanol and/or burn. These increases were prevented by insulin. An antiinflammatory cytokine was reduced by ethanol and/or burn. Insulin prevented this decrease. Thus, insulin has a substantial antiinflammatory effect, and this may underlie its dramatic clinical benefit in critical illness.
Collapse
Affiliation(s)
- Mary Ann Emanuele
- Department of Medicine, Division of Endocrinology and Metabolism, Loyola University Medical Center, 2160 South First Avenue, Building 54, Room 137, Maywood, IL 69153, USA
| | | | | | | | | |
Collapse
|
11
|
Madihally SV, Pantelogianis A, Toner M. Antiproteolytic Action of Orally Delivered Insulin Using pH-Responsive Hydrogels in a Rat Burn Model. J Surg Res 2006; 135:187-94. [PMID: 16616764 DOI: 10.1016/j.jss.2006.01.029] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2005] [Revised: 01/10/2006] [Accepted: 01/23/2006] [Indexed: 11/22/2022]
Abstract
Subcutaneously delivered small doses of insulin has shown beneficial effects on burn injury-induced muscle wasting and wound healing. To improve the method of insulin treatment for clinical settings, this study investigated the effect of insulin delivered orally using pH-responsive poly(methacrylic-g-ethylene glycol) (P(MAA-g-EG)) hydrogels in a 20% total burn surface area rat burn injury model. P(MAA-g-EG) were synthesized in-house and insulin release characteristics were performed in vitro. Young rats weighing 80-150 g were subjected to 15-20% total body surface area burn injury and treated with insulin-containing hydrogels enclosed in gelatin capsules for 3 days. The dosage was adjusted to match 0.25 U (day 1), 0.5U (day 2), and 1.0 U (day 3) per 100 grams of body weight. All animals were housed in metabolic cages and their physical activity, body weight, food consumption, water uptake, circulating glucose levels, and urinary tyrosine content were monitored for 4 to 15 days after burn. Results show that the orally delivered insulin restored the body weight of burned rats and influenced wound healing, similar to subcutaneous delivery. Measured glucose levels showed significantly less perturbation, suggesting the possibility of increasing the dosage. In conclusion, muscle wasting can be significantly inhibited by the oral administration of insulin using pH-responsive hydrogels.
Collapse
|
12
|
Anderson RA, Sandre C, Bryden NA, Agay D, Chancerelle Y, Polansky MM, Roussel AM. Burn-induced alterations of chromium and the glucose/insulin system in rats. Burns 2006; 32:46-51. [PMID: 16384652 DOI: 10.1016/j.burns.2005.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2005] [Accepted: 08/11/2005] [Indexed: 01/04/2023]
Abstract
Our objective was to demonstrate a role of chromium (Cr) in response to severe burn. A third-degree burn involving 20% of total body surface was applied under anaesthesia in accord with ethical guidelines. Chromium concentrations in liver decreased progressively and were non-detectable on days 5 and 10 following injury. In quadriceps muscle, Cr concentrations increased 6h after injury and then declined significantly within the first day and remained at these levels the following 9 days. Urinary Cr losses were also increased. Changes in kidney, brain and serum Cr were not significant. Non-fasting glucose rose 6h after injury and then returned to levels measured before the burn. There was a significant rise in corticosterone reaching a maximum the first day after injury that was accompanied by significant increases in circulating insulin and glucagon that were maximal after 2 days. Changes in IGF-1 were not significant. In summary, changes in Cr concentrations were associated with an early hyperglycemia, hyperinsulinemia and increased secretion of stress hormones. These observations strongly suggest a mobilization and utilization of Cr following severe burn. Additional studies are needed to document that improved Cr status might lead to improved recovery following burn.
Collapse
Affiliation(s)
- Richard A Anderson
- Nutrient Requirements and Functions Laboratory, Beltsville Human Nutrition Research Center, Agriculture Research Service, United States Department of Agriculture, Beltsville, MD 20705, USA.
| | | | | | | | | | | | | |
Collapse
|
13
|
Sanchez OA, Snow LM, Lowe DA, Serfass RC, Thompson LV. Effects of endurance exercise-training on single-fiber contractile properties of insulin-treated streptozotocin-induced diabetic rats. J Appl Physiol (1985) 2005; 99:472-8. [PMID: 15831797 DOI: 10.1152/japplphysiol.01233.2004] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The purpose of this study was to characterize the contractile properties of individual skinned muscle fibers from insulin-treated streptozotocin-induced diabetic rats after an endurance exercise training program. We hypothesized that single-fiber contractile function would decrease in the diabetic sedentary rats and that endurance exercise would preserve the function. In the study, 28 rats were assigned to either a nondiabetic sedentary, a nondiabetic exercise, a diabetic sedentary, or a diabetic exercise group. Rats in the diabetic groups received subcutaneous intermediate-lasting insulin daily. The exercise-trained rats ran on a treadmill at a moderate intensity for 60 min, five times per week. After 12 wk, the extensor digitorum longus and soleus muscles were dissected. Single-fiber diameter, Ca2+-activated peak force, specific tension, activation threshold, and pCa50as well as the myosin heavy chain isoform expression (MHC) were determined. We found that in MHC type II fibers from extensor digitorum longus muscle, diameters were significantly smaller from diabetic sedentary rats compared with nondiabetic sedentary rats ( P < 0.001). Among the nondiabetic rats, fiber diameters were smaller with exercise ( P = 0.038). The absolute force-generating capacity of single fibers was lower in muscles from diabetic rats. There was greater specific tension (force normalized to cross-sectional area) by fibers from the rats that followed an endurance exercise program compared with sedentary. From the results, we conclude that alterations in the properties of contractile proteins are not implicated in the decrease in strength associated with diabetes and that endurance-exercise training does not prevent or increase muscle weakness in diabetic rats.
Collapse
MESH Headings
- Adaptation, Physiological/physiology
- Animals
- Cells, Cultured
- Diabetes Mellitus, Experimental/chemically induced
- Diabetes Mellitus, Experimental/drug therapy
- Diabetes Mellitus, Experimental/physiopathology
- Insulin/therapeutic use
- Isometric Contraction
- Muscle Fibers, Skeletal
- Muscle, Skeletal/physiopathology
- Physical Conditioning, Animal/methods
- Physical Endurance
- Rats
- Rats, Sprague-Dawley
- Streptozocin
- Stress, Mechanical
Collapse
Affiliation(s)
- Otto A Sanchez
- School of Kinesiology, University of Minnesota Medical School, 420 Delaware Street, Minneapolis, MN 55455, USA
| | | | | | | | | |
Collapse
|
14
|
Banta S, Yokoyama T, Berthiaume F, Yarmush ML. Quantitative effects of thermal injury and insulin on the metabolism of the skeletal muscle using the perfused rat hindquarter preparation. Biotechnol Bioeng 2005; 88:613-29. [PMID: 15470703 DOI: 10.1002/bit.20258] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Injury from a severe burn or trauma can propel the body into a hypermetabolic state that can lead to the significant erosion of lean muscle mass. Investigations describing this process have been somewhat limited due to the lack of adequate experimental models. Here we report the use of a perfused rat hindquarter preparation to study the consequences of a moderate burn injury (approximately 20% total body surface area), with or without the addition of exogenous insulin (12.5 mU/mL), on the fluxes of major metabolites across the isolated skeletal muscle. The metabolic flux data was further analyzed using metabolic flux analysis (MFA), which allows for the estimation of the impact of these conditions on the intracellular muscle metabolism. Results indicate that this model is able to capture the increased rate of proteolysis, glutamine formation, and the negative nitrogen balance associated with the burn-induced hypermetabolic state. The inclusion of exogenous insulin resulted in significant changes in several fluxes, including an increase in the metabolism of glucose and the flux through the pentose phosphate pathway, as well as a reduction in the metabolism of glutamine, alanine, and leucine. However, insulin administration did not affect the nitrogen balance or the rate of proteolysis in the muscle, as has been suggested using other techniques. The use of the perfused hindquarter model coupled with MFA is a physiologically relevant and experimentally flexible platform for the exploration of skeletal muscle metabolism under catabolic conditions, and it will be useful in quantifying the specific metabolic consequences of other therapeutic advances.
Collapse
Affiliation(s)
- Scott Banta
- Center for Engineering in Medicine, Shriners Hospital for Children, Massachusetts General Hospital, and Harvard Medical School, 51 Blossom Street, Boston, Massachusetts 02114, USA
| | | | | | | |
Collapse
|
15
|
Abstract
PURPOSE OF REVIEW This review highlights recent publications dealing with the nature of the in-vivo response of skeletal muscle to critical illness and approaches to attenuating this response. Studies focused on molecular mechanisms of muscle catabolism are not reviewed. RECENT FINDINGS The general areas covered are the metabolic response to stress, particularly regarding the relationship between muscle protein breakdown, amino acid availability, and muscle protein synthesis. The impact of the profile of amino acids in the context of protein/amino acid intake is also discussed. Advances in our understanding of the hormonal response are considered, and use of insulin therapy to slow muscle catabolism is discussed. SUMMARY Muscle catabolism is a fundamental response to severe stress, and the resulting amino acid efflux from muscle provides important precursors for protein synthesis in other parts of the body. The nature of this response (i.e. transport kinetics favoring efflux of amino acids from muscle) makes amelioration of the catabolic response of muscle with nutrition alone very difficult. Many approaches have been used to reverse catabolism, mostly involving various anabolic hormones. Recent studies using insulin therapy are particularly intriguing because of the low cost and powerful anabolic stimulus of insulin.
Collapse
Affiliation(s)
- Robert R Wolfe
- The University of Texas Medical Branch, Department of Surgery and Shriners Burns Hospital, Metabolism Unit, Galveston, Texas, USA.
| |
Collapse
|
16
|
Vemula M, Berthiaume F, Jayaraman A, Yarmush ML. Expression profiling analysis of the metabolic and inflammatory changes following burn injury in rats. Physiol Genomics 2004; 18:87-98. [PMID: 15114001 DOI: 10.1152/physiolgenomics.00189.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Burn injury initiates an inflammatory response as part of the healing process that is associated with extensive metabolic adjustments. While most studies have focused on understanding these changes from a biochemical perspective, not much work has been done to characterize these processes at the gene expression level. As a first step, we have comprehensively analyzed changes in gene expression in rat livers during the first 24 h after burn injury using Affymetrix GeneChips, which showed 339 genes to be differentially expressed at a statistical significance of P < 0.05 and changed at least twofold. Functional classification based on gene ontology terms indicated that two categories, metabolism (28%) and inflammation (14%), accounted for nearly 42%. Detailed analysis of the metabolism group of genes indicated that fatty acid (FA) and triglyceride (TG) biosynthesis in the liver were unchanged, whereas TG utilization, FA import, and beta-oxidation increased after burn injury. The increased FA pools after burn injury appear to serve as substrates for ATP production. Following burn injury, the cholesterol biosynthetic pathway was suppressed while cholesterol was increasingly imported and converted into bile acids. The inflammatory genes that were altered included several classic acute phase response markers, as well as genes involved in the complement, kinin, clotting, and fibrinolytic protein systems. These temporally coordinated changes in gene expression were also corroborated by biochemical measurements for FA, TG, cholesterol, and ATP. Together, these data indicate that FA are increasingly imported and oxidized in the liver to meet the enhanced energy demands arising from an inflammatory response during the first 24 h after burn injury.
Collapse
Affiliation(s)
- M Vemula
- Center for Engineering in Medicine/Department of Surgery, Massachusetts General Hospital, Harvard Medical School and Shriners Hospital for Children, Boston, Massachusetts 02114, USA
| | | | | | | |
Collapse
|
17
|
Affiliation(s)
- Jeffrey R Saffle
- Department of Surgery, Intermountain Burn Center, University of Utah Health Center, Salt Lake City, UT 84132, USA
| |
Collapse
|
18
|
Madibally SV, Solomon V, Mitchell RN, Van De Water L, Yarmush ML, Toner M. Influence of insulin therapy on burn wound healing in rats. J Surg Res 2003; 109:92-100. [PMID: 12643849 DOI: 10.1016/s0022-4804(02)00036-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Insulin is proposed as a therapy for suppressing muscle wasting after burn trauma although the long-term effects of this therapy on wound healing are not yet known. The present study was designed to investigate the effect of systemically administered insulin therapy on burn wound healing. MATERIALS AND METHODS Young rats weighing 80-150 g were subjected to 15-20% total body surface area burn injury on their shaved dorsum. The insulin dosage was increased over the first 3 days in each rat from 0.25 U (Day 1), 0.5 U (Day 2), and 1.0 U (Day 3) per 100 g body wt. The rats were euthanized at the fourth or fifteenth day postinjury. Skin sections were analyzed by histochemistry and quantitative polarization microscopy. RESULTS Histology showed a decreased number of inflammatory cells and increased vasodilation in the insulin-treated animals at Day 4 relative to untreated rats; at Day 15 there was increased reepithelialization. Quantitative analysis using polarization microscopy and picrosirius red staining showed an increased collagen deposition in wounds by Day 4 in insulin-treated rats relative to untreated burn controls. CONCLUSION These results indicate that insulin induces accelerated wound healing associated with diminished inflammation and increased collagen deposition.
Collapse
Affiliation(s)
- Sundararajan V Madibally
- Shriners Burns Hospital, Surgical Services and the Center for Engineering in Medicine, Massachusetts General Hospital, and Harvard Medical School, Boston, Massachusetts 02114, USA
| | | | | | | | | | | |
Collapse
|