Anna-Sophie Bremer

Neonatal hypoxic–ischemic encephalopathy (HIE) is a major cause of neonatal mortality and long-term neurological disability, affecting 1–3 per 1000 live births in developed countries and occurring at substantially higher rates in developing countries. Neuroinflammation is a key contributor to disease progression, with growing evidence implicating the activation of the NLR family pyrin domain containing 3 (NLRP3) inflammasome following hypoxic–ischemic (HI) injury. In this study, we investigated the role and regulation of the NLRP3 inflammasome in neonatal HIE using in vitro and in vivo models. Primary microglial cultures subjected to oxygen–glucose deprivation and the Vannucci neonatal rat model of HI were used to characterize NLRP3 activation and its contribution to injury. We demonstrated that HI induces NLRP3 inflammasome activation, whereas pharmacological inhibition of NLRP3 enhances cell viability and attenuates brain damage. Our findings identify microglia as a central mediator of NLRP3-driven neuroinflammation and highlight microglial NLRP3 signaling as a promising therapeutic target for neuroinflammatory diseases. Collectively, this study provides an integrated view of NLRP3 regulation in neonatal HIE and supports inflammasome-directed strategies for neuroprotection following neonatal HI injury.

Neonatal hypoxic-ischemic encephalopathy is the most common cause of long-term disability in term neonates, and white matter injury is the primary cause of cerebral palsy. Therapies that focus on the neuroprotection of myelination and oligodendrocyte proliferation could potentially ameliorate long-lasting neurological impairments after hypoxic-ischemic encephalopathy. Clemastine, a histamine H1 antagonist, has been shown to exert neuroprotective effects in multiple sclerosis and spinal cord injury by promoting oligodendrogenesis and re-myelination. In this study, we demonstrated the neuroprotective effects of clemastine in our rat model of neonatal hypoxic-ischemic brain injury. Animals received a single intraperitoneal injection of either vehicle or clemastine (10 mg/kg) for 6 consecutive days. Our results showed a significant reduction in white matter loss after treatment, with a clear effect of clemastine on oligodendrocytes, showing a significant increase in the number of Olig2+ cells. We characterized the MAPK/ERK pathway as a potential mechanistic pathway underlying the neuroprotective effects of clemastine. Altogether, our results demonstrate that clemastine is a potential compound for the treatment of hypoxic-ischemic encephalopathy, with a clear neuroprotective effect on white matter injury by promoting oligodendrogenesis.