Single administration of tripeptide α-MSH(11-13) attenuates brain damage by reduced inflammation and apoptosis after experimental traumatic brain injury in mice

PLoS One. 2013 Aug 5;8(8):e71056. doi: 10.1371/journal.pone.0071056. Print 2013.

Abstract

Following traumatic brain injury (TBI) neuroinflammatory processes promote neuronal cell loss. Alpha-melanocyte-stimulating hormone (α-MSH) is a neuropeptide with immunomodulatory properties, which may offer neuroprotection. Due to short half-life and pigmentary side-effects of α-MSH, the C-terminal tripeptide α-MSH(11-13) may be an anti-inflammatory alternative. The present study investigated the mRNA concentrations of the precursor hormone proopiomelanocortin (POMC) and of melanocortin receptors 1 and 4 (MC1R/MC4R) in naive mice and 15 min, 6, 12, 24, and 48 h after controlled cortical impact (CCI). Regulation of POMC and MC4R expression did not change after trauma, while MC1R levels increased over time with a 3-fold maximum at 12 h compared to naive brain tissue. The effect of α-MSH(11-13) on secondary lesion volume determined in cresyl violet stained sections (intraperitoneal injection 30 min after insult of 1 mg/kg α-MSH(11-13) or 0.9% NaCl) showed a considerable smaller trauma in α-MSH(11-13) injected mice. The expression of the inflammatory markers TNF-α and IL-1β as well as the total amount of Iba-1 positive cells were not reduced. However, cell branch counting of Iba-1 positive cells revealed a reduced activation of microglia. Furthermore, tripeptide injection reduced neuronal apoptosis analyzed by cleaved caspase-3 and NeuN staining. Based on the results single α-MSH(11-13) administration offers a promising neuroprotective property by modulation of inflammation and prevention of apoptosis after traumatic brain injury.

MeSH terms

  • Animals
  • Anti-Inflammatory Agents / administration & dosage*
  • Apoptosis / drug effects*
  • Brain / drug effects
  • Brain / immunology
  • Brain / metabolism
  • Brain Injuries / drug therapy*
  • Brain Injuries / immunology
  • Brain Injuries / metabolism
  • Calcium-Binding Proteins / metabolism
  • Gene Expression
  • Inflammation Mediators / metabolism
  • Male
  • Melanocyte-Stimulating Hormones / administration & dosage*
  • Mice
  • Mice, Inbred C57BL
  • Microfilament Proteins / metabolism
  • Microglia / drug effects
  • Microglia / metabolism
  • Peptide Fragments / administration & dosage*
  • Pro-Opiomelanocortin / genetics
  • Pro-Opiomelanocortin / metabolism
  • Receptor, Melanocortin, Type 1 / genetics
  • Receptor, Melanocortin, Type 1 / metabolism
  • Receptor, Melanocortin, Type 4 / genetics
  • Receptor, Melanocortin, Type 4 / metabolism

Substances

  • Aif1 protein, mouse
  • Anti-Inflammatory Agents
  • Calcium-Binding Proteins
  • Inflammation Mediators
  • MC4R protein, mouse
  • Microfilament Proteins
  • Peptide Fragments
  • Receptor, Melanocortin, Type 1
  • Receptor, Melanocortin, Type 4
  • Pro-Opiomelanocortin
  • MSH (11-13)
  • Melanocyte-Stimulating Hormones

Grants and funding

The authors have no funding or support to report.