Dataset Information

Targeting the mitochondrial permeability transition pore for neuroprotection in a piglet model of neonatal hypoxic-ischemic encephalopathy.

ABSTRACT: Neonatal hypoxic-ischemic encephalopathy (HIE) causes significant morbidity despite treatment with therapeutic hypothermia. Mitochondrial dysfunction may drive the mechanisms underlying neuronal cell death, thereby making mitochondria prime targets for neuroprotection. The mitochondrial permeability transition pore (mPTP) is one such target within mitochondria. In adult animal models, mPTP inhibition is neuroprotective. However, evidence for mPTP inhibition in neonatal models of neurologic disease is less certain. We tested the therapeutic efficacy of the mPTP small molecule inhibitor GNX-4728 and examined the developmental presence of brain mPTP proteins for drug targeting in a neonatal piglet model of hypoxic-ischemic brain injury. Male neonatal piglets were randomized to hypoxia-ischemia (HI) or sham procedure with GNX-4728 (15 mg/kg, IV) or vehicle (saline/cyclodextrin/DMSO, IV). GNX-4728 was administered as a single dose within 5 min after resuscitation from bradycardic arrest. Normal, ischemic, and injured neurons were counted in putamen and somatosensory cortex using hematoxylin and eosin staining. In separate neonatal and juvenile pigs, western blots of putamen mitochondrial-enriched fractions were used to evaluate mitochondrial integrity and the presence of mPTP proteins. We found that a single dose of GNX-4728 did not protect putamen and cortical neurons from cell death after HI. However, loss of mitochondrial matrix integrity occurred within 6h after HI, and while mPTP components are present in the neonatal brain their levels were significantly different compared to that of a mature juvenile brain. Thus, the neonatal brain mPTP may not be a good target for current neurotherapeutic drugs that are developed based on adult mitochondria.

SUBMITTER: Chen MW

PROVIDER: S-EPMC8725033 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:Interferon regulatory factor 4 (IRF4), a transcription factor recognized as a key regulator of lymphoid and myeloid cell differentiation, has recently been recognized as a critical mediator of macrophage activation. Previously we have reported that IRF4 signaling is closely correlated with anti-inflammatory polarization of microglia in adult mice after stroke. However, IRF4's role in the inflammatory response in the immature brain is unknown. Using a model of neonatal hypoxic ischemic encephalopathy (HIE) we investigated the regulatory action of IRF4 signaling in the activation of microglia and monocytes after HIE. IRF4 myeloid cell conditional knockout (CKO) postnatal day 10 (P10) male pups were subjected to a 60-min hypoxic-ischemic insult by the Rice-Vanucci model (RVM). IRF4 gene floxed mice (IRF4fl/fl) were used as controls. Brain atrophy and behavioral deficits were measured 7 days after HIE. Flow cytometry (FC) was performed to examine central (microglial activation) and peripheral immune cell responses by both cell membrane and intracellular marker staining. Serum levels of cytokines were determined by ELISA. The results showed that IRF4 CKO pups had increased tissue loss and worse behavioral deficits than IRF4fl/fl mice seven days after HIE. FC demonstrated significantly more infiltration of monocytes and neutrophils in the ischemic brains of IRF4 CKO vs IRF4fl/fl pups. IRF4 CKO ischemic microglia were more pro-inflammatory as evidenced by higher expression of the pro-inflammatory marker CD68, and increased intracellular TNF? and IL-1? levels compared to controls. In addition, IRF4 deletion from myeloid cells resulted in increased levels of circulating pro-inflammatory cytokines and higher endothelial MMP9 expression after HIE. These data indicate that IRF4 signaling in myeloid cells plays a regulatory role in neuroinflammation and that deletion of myeloid IRF4 is detrimental to HIE injury, suggesting that IRF4 could serve as a potential therapeutic target for neonatal ischemic brain injury.

Dataset Information

Targeting the mitochondrial permeability transition pore for neuroprotection in a piglet model of neonatal hypoxic-ischemic encephalopathy.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure