Age-dependent chemokine protein desensitization following stretch-shortening contraction musculoskeletal injury

Details

• Personal Author:
  Baker BA ; Ensey J ; Baker BA ; Ensey J
• Description:
  Despite evidence that increased age negatively impacts the functional and physiological recovery of soft tissue following traumatic musculoskeletal injury, there is no consensus as to the mechanism(s) at the molecular/cellular level by which this takes place. PURPOSE: To investigate if there is an age-dependent differential responsiveness to chemokine proteins following stretch-shortening contraction (SSC)- induced musculoskeletal injury. METHODS: Using an in vivo rodent dynamometry model and an NIA-approved animal model of aging (Fisher 344 x Brown Norway Rat), we exposed young and old rats acutely to either zero (0) SSCs or 150 injurious SSCs and assessed multiple chemokine protein responses in tibialis anterior muscle at three days recovery in these populations (n = 8 rats/group). Two-way ANOVA was used for statistical analysis; significance was set at p < 0.05. RESULTS: Following in vivo SSC-injury loading, young rats exhibited increased concentrations of the chemokine proteins RANTES/CCL5 approximately 5 Fold (164.2 + 21.5 vs. 31.1 + 7.6 pg/ml, p < 0.01), GROKC/ CXCL2 approximately 13 Fold (157.6 + 42.1 vs. 11.2 + 3.0 pg/ml, p < 0.001), MCP-1/CCL2 approximately 48 Fold (2,920.6 + 844.0 vs. 60.2 + 10.3 pg./ml, p < 0.0001), and MIP-1alpha approximately 31 Fold (220.5 + 65.6 vs. 7.2 + 1.2 pg/ml p < 0.0001), whereas no such change was observed in old rats. Further, when normalized to old rats, young rats' chemokine protein concentrations were higher for GRO-KC/CXCL2 approximately 5 Fold (157.6 + 42.1 vs. 29.2 + 11.2 pg/ml, p < 0.001), MCP-1/CCL2 approximately 12 Fold (2,920.6 + 844.0 vs. 235.4 + 46.7 pg/ ml, p < 0.0001), and MIP-1alpha approximately 19 Fold (220.5 + 65.6 vs. 11.3 + 2.3 pg/ml, p < 0.0001). CONCLUSIONS: These in vivo data reveal that specific inflammatory mediators, specifically chemokines, in young rats may contribute to a positive healing response following SSC-injury loading; and, actually may become desensitized with increased age. These data may help contribute to explaining the delayed recovery kinetics at the functional level observed with aged populations following traumatic musculoskeletal injury. [Description provided by NIOSH]
• Subjects:
  Age Factors Animals Laboratories Musculoskeletal Diseases Musculoskeletal System Occupational Health Safety
• Keywords:
  Age-factors Cellular-function Injuries Laboratory-animals Molecular-biology Muscle-physiology Musculoskeletal-system Musculoskeletal-system-disorders Physiological-effects Physiological-function Physiology Proteins Statistical-analysis Traumatic-injuries

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• ISSN:
  0195-9131
• Document Type:
  Text
• Genre:
  Abstract or Summary ; Abstract or Summary
• Place as Subject:
  OSHA Region 3 ; West Virginia
• CIO:
  National Institute for Occupational Safety and Health (NIOSH) ; National Institute for Occupational Safety and Health (NIOSH)
• Division:
  HELD - Health Effects Laboratory Division ; HELD - Health Effects Laboratory Division
• Topic:
  Workplace Safety & Health ; Workplace Safety & Health
• Location:
  North America ; North America
• Volume:
  46
• Issue:
  5
• NIOSHTIC Number:
  nn:20044932
• Citation:
  Med Sci Sports Exerc 2014 May; 46(5)(Suppl 1):922
• Federal Fiscal Year:
  2014
• Peer Reviewed:
  False
• Source Full Name:
  Medicine and Science in Sports and Exercise
• Supplement:
  1
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:840cf578c2757dcfac71cd6cf91b8e77f314f72384a732e715c1f4c84a5d99b871be50ef7f9567b5e138b606c4a01bedf21d7039de6182a51faea5facb3123d8
• Download URL:
  https://stacks.cdc.gov/view/cdc/200516/cdc_200516_DS1.pdf
• File Type:
  [PDF - 498.23 KB ]