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Combination treatment with ethyl pyruvate and IGF-I exerts neuroprotective effects against brain injury in a rat model of neonatal hypoxic-ischemic encephalopathy.

Rong Z, Pan R, Chang L, Lee W - Int. J. Mol. Med. (2015)

Bottom Line: Under conditions of OGD, the LDH levels increased and neuronal viability decreased.Treatment with 0.5 mM EP or 25 ng/ml IGF‑I protected the neurons (P<0.05), exerting additive effects.This effect may be the result of reduced neuronal injury, and enhanced neurogenesis and maturation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.

ABSTRACT
Neonatal hypoxic-ischemic (HI) brain injury causes severe brain damage in newborns. Following HI injury, rapidly accumulating oxidants injure neurons and interrupt ongoing developmental processes. The antioxidant, sodium pyruvate, has been shown to reduce neuronal injury in neonatal rats under conditions of oxygen glucose deprivation (OGD) and HI injury. In this study, we evaluated the effects of ethyl pyruvate (EP) and insulin‑like growth factor‑I (IGF‑I) alone or in combination in a similar setting. For this purpose, we used an in vitro model involving primary neonatal rat cortical neurons subjected to OGD for 2.5 h and an in vivo model involving unilateral carotid ligation in rats on post-natal day 7 with exposure to 8% hypoxia for 2.5 h. The cultured neurons were examined by lactate dehydrogenase (LDH) and cell viability assays. For the in vivo experiments, behavioral development was evaluated by the foot fault test at 4 weeks of recovery. 2,3,5‑Triphenyltetrazolium chloride monohydrate and cresyl violet staining were used to evaluate HI injury. The injured neurons were Fluoro‑Jade B-labeled, new neuroprecursors were double labeled with bromodeoxyuridine (BrdU) and doublecortin, new mature neurons were BrdU-labeled and neuronal nuclei were labeled by immunofluorescence. Under conditions of OGD, the LDH levels increased and neuronal viability decreased. Treatment with 0.5 mM EP or 25 ng/ml IGF‑I protected the neurons (P<0.05), exerting additive effects. Similarly, either the early administration of EP or delayed treatment with IGF‑I protected the neonatal rat brains against HI injury and improved neurological performance and these effects were also additive. This effect may be the result of reduced neuronal injury, and enhanced neurogenesis and maturation. On the whole, our findings demonstrate that the combination of the early administration of EP with delayed treatment with IGF‑I exerts neuroprotective effects against HI injury in neonatal rat brains.

No MeSH data available.


Related in: MedlinePlus

Ethyl pyruvate (EP) and insulin-like growth factor-I (IGF-I) protect primary cortical neurons against oxygen glucose deprivation (OGD). (A) EP reduced OGD-induced neuronal cell injury in a dose-dependent manner, as indicated by the reduced lactate dehydrogenase (LDH) levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 and **P<0.01, compared with OGD alone (n=6). (B) IGF-I reduced OGD-induced neuronal injury in a dose-dependent manner, as indicated by the reduced LDH levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 compared with OGD alone (n=6). (C) Combined treatment with EP (0.5 mM) and IGF-I (25 ng/ml) further reduced OGD-induced neuronal cell injury than with each treatment alone. *P<0.05 as indicated (n=6).
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f1-ijmm-36-01-0195: Ethyl pyruvate (EP) and insulin-like growth factor-I (IGF-I) protect primary cortical neurons against oxygen glucose deprivation (OGD). (A) EP reduced OGD-induced neuronal cell injury in a dose-dependent manner, as indicated by the reduced lactate dehydrogenase (LDH) levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 and **P<0.01, compared with OGD alone (n=6). (B) IGF-I reduced OGD-induced neuronal injury in a dose-dependent manner, as indicated by the reduced LDH levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 compared with OGD alone (n=6). (C) Combined treatment with EP (0.5 mM) and IGF-I (25 ng/ml) further reduced OGD-induced neuronal cell injury than with each treatment alone. *P<0.05 as indicated (n=6).

Mentions: To examine the neuroprotective effects of EP and/or IGF-I against HI injury, we first examined the degree of neuronal injury by LDH assay and cell viability (by MTT assay) in the absence or presence of increasing concentrations of EP or IGF-I under conditions of OGD (17). Under conditions of OGD, the LDH levels were increased in the culture medium and the MTT levels were decreased in the cell lysate at 24 h of reoxygenation, suggesting neuronal injury under oxidative stress (Fig. 1A and B). As the concentration of EP or IGF-I increased in the culture medium, the LDH levels decreased and the MTT levels increased (Fig. 1A and B), both in a dose-dependent manner, indicating a decrease in neuronal injury and an increase in neuronal cell viability. The neuroprotective effects were the most prominent when EP (0.5 mM) was combined with IGF-I (25 ng/ml) as compared to treatment with EP or IGF-I alone (Fig. 1C).


Combination treatment with ethyl pyruvate and IGF-I exerts neuroprotective effects against brain injury in a rat model of neonatal hypoxic-ischemic encephalopathy.

Rong Z, Pan R, Chang L, Lee W - Int. J. Mol. Med. (2015)

Ethyl pyruvate (EP) and insulin-like growth factor-I (IGF-I) protect primary cortical neurons against oxygen glucose deprivation (OGD). (A) EP reduced OGD-induced neuronal cell injury in a dose-dependent manner, as indicated by the reduced lactate dehydrogenase (LDH) levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 and **P<0.01, compared with OGD alone (n=6). (B) IGF-I reduced OGD-induced neuronal injury in a dose-dependent manner, as indicated by the reduced LDH levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 compared with OGD alone (n=6). (C) Combined treatment with EP (0.5 mM) and IGF-I (25 ng/ml) further reduced OGD-induced neuronal cell injury than with each treatment alone. *P<0.05 as indicated (n=6).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4494588&req=5

f1-ijmm-36-01-0195: Ethyl pyruvate (EP) and insulin-like growth factor-I (IGF-I) protect primary cortical neurons against oxygen glucose deprivation (OGD). (A) EP reduced OGD-induced neuronal cell injury in a dose-dependent manner, as indicated by the reduced lactate dehydrogenase (LDH) levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 and **P<0.01, compared with OGD alone (n=6). (B) IGF-I reduced OGD-induced neuronal injury in a dose-dependent manner, as indicated by the reduced LDH levels in the culture medium and the increased MTT levels in the cell lysates at 24 h of reoxygenation. *P<0.05 compared with OGD alone (n=6). (C) Combined treatment with EP (0.5 mM) and IGF-I (25 ng/ml) further reduced OGD-induced neuronal cell injury than with each treatment alone. *P<0.05 as indicated (n=6).
Mentions: To examine the neuroprotective effects of EP and/or IGF-I against HI injury, we first examined the degree of neuronal injury by LDH assay and cell viability (by MTT assay) in the absence or presence of increasing concentrations of EP or IGF-I under conditions of OGD (17). Under conditions of OGD, the LDH levels were increased in the culture medium and the MTT levels were decreased in the cell lysate at 24 h of reoxygenation, suggesting neuronal injury under oxidative stress (Fig. 1A and B). As the concentration of EP or IGF-I increased in the culture medium, the LDH levels decreased and the MTT levels increased (Fig. 1A and B), both in a dose-dependent manner, indicating a decrease in neuronal injury and an increase in neuronal cell viability. The neuroprotective effects were the most prominent when EP (0.5 mM) was combined with IGF-I (25 ng/ml) as compared to treatment with EP or IGF-I alone (Fig. 1C).

Bottom Line: Under conditions of OGD, the LDH levels increased and neuronal viability decreased.Treatment with 0.5 mM EP or 25 ng/ml IGF‑I protected the neurons (P<0.05), exerting additive effects.This effect may be the result of reduced neuronal injury, and enhanced neurogenesis and maturation.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.

ABSTRACT
Neonatal hypoxic-ischemic (HI) brain injury causes severe brain damage in newborns. Following HI injury, rapidly accumulating oxidants injure neurons and interrupt ongoing developmental processes. The antioxidant, sodium pyruvate, has been shown to reduce neuronal injury in neonatal rats under conditions of oxygen glucose deprivation (OGD) and HI injury. In this study, we evaluated the effects of ethyl pyruvate (EP) and insulin‑like growth factor‑I (IGF‑I) alone or in combination in a similar setting. For this purpose, we used an in vitro model involving primary neonatal rat cortical neurons subjected to OGD for 2.5 h and an in vivo model involving unilateral carotid ligation in rats on post-natal day 7 with exposure to 8% hypoxia for 2.5 h. The cultured neurons were examined by lactate dehydrogenase (LDH) and cell viability assays. For the in vivo experiments, behavioral development was evaluated by the foot fault test at 4 weeks of recovery. 2,3,5‑Triphenyltetrazolium chloride monohydrate and cresyl violet staining were used to evaluate HI injury. The injured neurons were Fluoro‑Jade B-labeled, new neuroprecursors were double labeled with bromodeoxyuridine (BrdU) and doublecortin, new mature neurons were BrdU-labeled and neuronal nuclei were labeled by immunofluorescence. Under conditions of OGD, the LDH levels increased and neuronal viability decreased. Treatment with 0.5 mM EP or 25 ng/ml IGF‑I protected the neurons (P<0.05), exerting additive effects. Similarly, either the early administration of EP or delayed treatment with IGF‑I protected the neonatal rat brains against HI injury and improved neurological performance and these effects were also additive. This effect may be the result of reduced neuronal injury, and enhanced neurogenesis and maturation. On the whole, our findings demonstrate that the combination of the early administration of EP with delayed treatment with IGF‑I exerts neuroprotective effects against HI injury in neonatal rat brains.

No MeSH data available.


Related in: MedlinePlus