Single Administration of Tripeptide ?-MSH(11–13) Attenuates Brain Damage by Reduced Inflammation and Apoptosis after Experimental Traumatic Brain Injury in Mice
2013
ABSTRACT
Following traumatic brain injury (TBI) neuroinflammatory processes promote neuronal cell loss. Alpha-melanocyte-stimulating hormone (?-MSH) is a neuropeptide with immunomodulatory properties, which may offer neuroprotection. Due to short half-life and pigmentary side-effects of ?-MSH, the C-terminal tripeptide ?-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 ?-MSH(11–13) on secondary lesion volume determined in cresyl violet stained sections (intraperitoneal injection 30 min after insult of 1 mg/kg ?-MSH(11–13) or 0.9% NaCl) showed a considerable smaller trauma in ?-MSH(11–13) injected mice. The expression of the inflammatory markers TNF-? and IL-1? 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 ?-MSH(11–13) administration offers a promising neuroprotective property by modulation of inflammation and prevention of apoptosis after traumatic brain injury.
I think this study is such a great one for traumatic injury patients. I hope many more studies will delve into this topic and certainly prove that administration of tripeptide is indeed helpful in traumatic brain injuries. These cases are extremely delicate and more often than not, very serious conditions. There are also cases wherein the patient goes into coma. Who knows if tripeptides can also help in those cases? The possibilities of using peptides are just beginning and probably way beyond what we know. If many more studies delve into this, I'm sure more people can be saved. And more lives can be saved!