The Alpha 7 Nicotinic Acetylcholine Receptor Does Not Affect Neonatal Brain Injury

• Inflammation plays a central role in the development of neonatal brain injury. The alpha 7 nicotinic acetylcholine receptor (alpha 7nAChR) can modulate inflammation and has shown promising results as a treatment target in rodent models of adult brain injury. However, little is known about the role of the alpha 7nAChR in neonatal brain injury. Hypoxic-ischemic (HI) brain injury was induced in male and female C57BL/6 mice, alpha 7nAChR knock-out (KO) mice and their littermate controls on postnatal day (PND) 9-10. C57BL/6 pups received i.p. injections of alpha 7nAChR agonist PHA 568487 (8 mg/kg) or saline once daily, with the first dose given directly after HI. Caspase-3 activity and cytokine mRNA expression in the brain was analyzed 24 h after HI. Motor function was assessed 24 and 48 h after HI, and immunohistochemistry was used to assess tissue loss at 24 h and 7 days after HI and microglial activation 7 days after HI. Activation of alpha 7nAChR with the agonist PHA 568487 significantly decreased CCL2/MCP-1, CCL5/RANTES and IL-6 gene expression in the injured brain hemisphere 24 h after HI compared with saline controls in male, but not female, pups. However, alpha 7nAChR activation did not alter caspase-3 activity and TNF alpha, IL-1 beta and CD68 mRNA expression. Furthermore, agonist treatment did not affect motor function (24 or 48 h), neuronal tissue loss (24 h or 7 days) or microglia activation (7 days) after HI in either sex. Knock-out of alpha 7nAChR did not influence neuronal tissue loss 7 days after HI. In conclusion, targeting the alpha 7nAChR in neonatal brain injury shows some effect on dampening acute inflammatory responses in male pups. However, this does not lead to an effect on overall injury outcome.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Farmakologi och toxikologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Pharmacology and Toxicology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Neurovetenskaper (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Neurosciences (hsv//eng)

NATURVETENSKAP  -- Biologi -- Utvecklingsbiologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Developmental Biology (hsv//eng)

Nyckelord

hypoxia-ischemia

neonatal mice

brain injury

alpha 7 nicotinic

acetylcholine receptor

inflammation

hypoxia-ischemia

oxidative stress

activation

adult

expression

stroke

encephalopathy

interleukin-6

inflammation

modulation

Biochemistry & Molecular Biology

Research & Experimental Medicine

Pharmacology & Pharmacy

neonatal mice

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