Effets du monoxyde d'azote inhalé sur le cerveau en développement chez le raton

L inhalation de monoxyde d azote (NO) est l une des thérapies les plus utilisées en réanimation néonatale. Cependant, peu de données sont disponibles sur l impact de l inhalation de NO sur le développement cérébral et le devenir des enfants prématurés. Nous avons étudié l impact du monoxyde d azote inhalé (iNO) sur le cerveau en développement chez le rongeur. Des portées et leur mère sont placés sous 5 à 20 ppm de NO de la naissance (P0) jusqu au 7ème jour de vie postnatal (P7). Les animaux exposés au NO présentent une augmentation transitoire de l angiogenèse et de la myélinisation, sans incidence sur les fonctions cognitives à l âge adulte. L exposition au NO est associée à une prolifération d oligodendrocytes immatures et à une maturation anticipée des formes myélinisantes. Les rôles du NO endogène et du couple VEGF/VEGFR2 dans ces effets ont été évalués via l injection d antagonistes : LNAME pour inhiber les NOS, SU-5416 comme antagoniste du VEGFR2. Dans les deux cas, l inhalation de NO corrige les anomalies de myélinisation et d angiogenèse induites par ces inhibiteurs. Nous avons soumis des ratons à une agression excitotoxique par injection intracérébrale d agonistes du glutamate. A P10 les rats exposés au iNO avant l injection présentent des lésions moins importantes ; ainsi qu un diminution de densité des microglies activées et des astrocytes. Cet effet neuroprotecteur est associé à une régulation de sous-unités des récepteurs au glutamate dès P5. Cet effet transcriptionnel semble lié à la modulation de la signalisation pCREB/Akt. Les effets à distance du iNO sont liés à un transport réversible endovasculaire du NO. In fine, du NO est delivré à la cellule et les concentrations intracellaires de cGMP augmentent d un facteur 5. Plusieurs facteurs de transcription sont régulés : PDGFR-a, Sema3F, les sous-unités des récepteurs au glutamate, Thrombospondine-1. Cette dernière est un antagoniste naturel de la signalisation NO-cGMP. L injection de ABT-510, agoniste de TSP-1, abolit les effets du iNO, confirmant l hypothèse que les effets à distance reposent sur la signalisation NO-Guanylate Cyclase soluble-cGMP. Au total, nous avons démontré que le iNO est transporté de manière réversible et delivré au cerveau en développement. Il y exerce un effet pro-angiogénique et pro-myélinisant, via une signalisation cGMP, régulée par la thrombospondine-1. Plus encore, l exposition prophylactique au iNO diminue l impact d une agression excitotoxique. Ce qui augure de propriétés neuroprotectrices prometteuses en néonatalogie, et au delà.Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates, but littlei known about its effect on the developing brain. We explored the effects of iNO on developing brain in rodent pups, and pathway involved in iNO remote effects. Rat pups and their mothers were placed in a chamber containing 5 to 20 ppm of NO for 7 days after birth. Extensive serum analysis, immunochemistry, RT-PCR analysis, were performed Neonatal exposure to iNO was associated with a transient increase in central nervous system myelination and angiogenesis in rats, without any behavioral consequences in adulthood. Exposure to iNO was associated with a proliferative effect on immature oligodendrocytes and a subsequent promaturational effect. The role of endogenous NO in myelination was investigated in animals treated with the nitric oxides synthase inhibitor N-nitro-L- arginine methyl ester (L-NAME) in the neonatal period ; this led to protracted myelination defects and subsequent behavioral deficits in adulthood. These effects were reversed by rescuing L-NAME-treated animals with iNO. We challenged animals with intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significantdecrease of several glutamate receptor subunits expression at P5. iNO was associated with an early(P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt proteinconcentration in response to excitotoxic challenge (P7) Those effects were related to a release of NOto the cells, and a rise of cGMP intracellular concentration. Several transcription factor wereregulated, namely PDGFR-a, Sema3F, TSP-1, glutamate receptors subunits, Thrombospondin-1. Thelatter was responsible for NO pathway regulation, and injection of TSP-1 agonist (AbT-510) abolishediNO remote effects. iNO remote effects are not associated VEGF concentration increase nor VEGFRstimulation, as VEGF-R antagonist SU54-16 failed to abolish iNO effects on angiogenesis andmyelination. Moreover iNO reverses severe myelination and angiogenesis defects induced by this SU-5416. Thus, we demonstrate transport and considerable remote effect of iNO on angiogenesis andmyelination in rodents. Those effects are related to an enhancement of cGMP pathway, regulated byTSP-1, and transcriptional effects. Moreover we described and investigated the neuroprotectiveeffect of iNO in neonatal excitotoxic-induced brain damage. These data point to potential newavenues for neuroprotection in human perinatal brain damage.PARIS5-Bibliotheque electronique (751069902) / SudocSudocFranceF

Protocol for a prospective multicenter longitudinal randomized controlled trial (CALIN) of sensory-tonic stimulation to foster parent child interactions and social cognition in very premature infants

IntroductionPremature birth is associated with long-term somatic and neurological disorders, including cognitive, social and behavioral impairments. Moreover, the mothers of infants born preterm exhibit a higher prevalence of anxiety and depressive symptoms after birth. Early rehabilitation, developmental care, and parenting support have already been shown to have a positive impact on neurological outcome. However, no randomized controlled study has so far assessed the effects on parenting and long-term neurological outcomes of proprioceptive stimulation to trigger positive brain plasticity in very preterm babies. The CALIN project will therefore investigate the impact of sensory-tonic stimulation (STS) of extremely preterm infants by their parents on child parent interactions, infants' morphological and functional brain development and subsequent cognition (including social cognition), and parents' anxiety and depressive symptoms in the postpartum period.Methods and analysisInfants born between 25 and 32 weeks of gestation will be randomly assigned to the “STS + Kangaroo care” or “Kangaroo care” group. The primary endpoint, child and parent interactions, will be rated at 12 months corrected age using the Coding Interactive Behavior system. Secondary endpoints include: 1/functional and anatomical brain maturation sequentially assessed during neonatal hospitalization using electroencephalogram (EEG), amplitude-integrated EEG (aEEG), cranial ultrasound and MRI performed at term-corrected age, 2/social and cognitive outcomes assessed at 15 months, 2, 4 and 6 years, and 3/parents' anxiety and depressive symptoms assessed at 7 ± 1 weeks after birth, using dedicated questionnaires.Ethics and disseminationThis study was approved by the French Ethics Committee for the Protection of Persons on 18 October 2021. It is registered with the French National Agency for the Safety of Medicines and Health Products (ANSM; no. 2020-A00382–37). The registry number on ClinicalTrials.gov is NCT04380051

Monitoring Cerebral and Renal Oxygenation Status during Neonatal Digestive Surgeries Using Near Infrared Spectroscopy

BackgroundDepending on the initial pathology, hypovolemia, intra-abdominal hypertension, and sepsis are often encountered in neonatal digestive surgery. Accurate newborn monitoring during and after surgery is essential to adapt resuscitation protocols. Near infrared spectroscopy (NIRS) is non-invasive and can detect hypoperfusion which indicates a low circulatory blood flow, regardless of the cause.ObjectiveEvaluating changes in cerebral and renal regional oxygen saturation during neonatal digestive surgeries, conducted according to normal practices, with commonly used monitoring parameters. Analyzing retrospectively the inter-relationships between NIRS values and mean arterial pressure (MAP) values as well as pre-ductal SpO2.MethodsProspective, descriptive, monocentric study. All neonates referred for surgery were included. NIRS allows the measurement of cerebral and renal oxygenation fluctuations, as well as calculating difference in intraoperative and postoperative values.ResultsNineteen patients were included. Cerebral regional oxygen saturation (C rSO2) values were stable while renal regional oxygen saturation (R rSO2) values tended to decrease with time during surgery. Indeed, 72% of rSO2 decline episodes occurred after the first 30 min of surgery, without any significant statistical differences for the next 90 min of surgery. After surgery, the lowest average C and R rSO2 values were evidenced during the first 6 h, with 60% of C rSO2 and R rSO2 anomalies occurring in that time frame. There was no significant statistical difference observed in the following 18 h. There was a significant correlation between R rSO2 and SpO2 values (p < 0.01), but not with C rSO2 values. There was no correlation with the MAP either for the C rSO2 values or R rSO2 ones.ConclusionNIRS is a promising non-invasive bedside tool to monitor cerebral and tissue perfusion, analyzing tissue microcirculation. NIRS has its interest to guide neonatal digestive surgeries (bowel manipulation, viscera reduction) and may represent an early warning for identifying patients requiring resuscitation during or after these surgeries

Neuroprotective Effect of Inhaled Nitric Oxide on Excitotoxic-Induced Brain Damage in Neonatal Rat

BACKGROUND: Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates. However, little information is known about its impact on the developing brain submitted to excitotoxic challenge. METHODOLOGY/PRINCIPAL FINDINGS: We investigated here the effect of iNO in a neonatal model of excitotoxic brain lesions. Rat pups and their dams were placed in a chamber containing 20 ppm NO during the first week of life. At postnatal day (P)5, rat pups were submitted to intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significant decrease of several glutamate receptor subunits expression at P5. iNO was associated with an early (P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt protein concentration in response to excitotoxic challenge (P7). CONCLUSION: This study is the first describe and investigate the neuroprotective effect of iNO in neonatal excitotoxic-induced brain damage. This effect may be mediated through CREB pathway and subsequent modulation of glutamate receptor subunits expression

Melatonin Promotes Oligodendroglial Maturation of Injured White Matter in Neonatal Rats

OBJECTIVE:To investigate the effects of melatonin treatment in a rat model of white matter damage (WMD) in the developing brain. Additionally, we aim to delineate the cellular mechanisms of melatonin effect on the oligodendroglial cell lineage. METHODS:A unilateral ligation of the uterine artery in pregnant rat at the embryonic day 17 induces fetal hypoxia and subsequent growth restriction (GR) in neonatal pups. GR and control pups received a daily intra-peritoneal injection of melatonin from birth to post-natal day (P) 3. RESULTS:Melatonin administration was associated with a dramatic decrease in microglial activation and astroglial reaction compared to untreated GR pups. At P14, melatonin prevented white matter myelination defects with an increased number of mature oligodendrocytes (APC-immunoreactive) in treated GR pups. Conversely, melatonin was not found to be associated with an increased density of total oligodendrocytes (Olig2-immunoreactive), suggesting that melatonin is able to promote oligodendrocyte maturation but not proliferation. These effects appear to be melatonin-receptor dependent and were reproduced in vitro. INTERPRETATION:These data suggest that melatonin has a strong protective effect on developing damaged white matter through decreased microglial activation and oligodendroglial maturation leading to a normalization of the myelination process. Consequently, melatonin should be a considered as an effective neuroprotective candidate not only in perinatal brain damage but also in inflammatory and demyelinating diseases observed in adults

Effect nitric oxide inhale on the developing brain of rats

L’inhalation de monoxyde d’azote (NO) est l’une des thérapies les plus utilisées en réanimation néonatale. Cependant, peu de données sont disponibles sur l’impact de l’inhalation de NO sur le développement cérébral et le devenir des enfants prématurés. Nous avons étudié l’impact du monoxyde d’azote inhalé (iNO) sur le cerveau en développement chez le rongeur. Des portées et leur mère sont placés sous 5 à 20 ppm de NO de la naissance (P0) jusqu’au 7ème jour de vie postnatal (P7). Les animaux exposés au NO présentent une augmentation transitoire de l’angiogenèse et de la myélinisation, sans incidence sur les fonctions cognitives à l’âge adulte. L’exposition au NO est associée à une prolifération d’oligodendrocytes immatures et à une maturation anticipée des formes myélinisantes. Les rôles du NO endogène et du couple VEGF/VEGFR2 dans ces effets ont été évalués via l’injection d’antagonistes : LNAME pour inhiber les NOS, SU-5416 comme antagoniste du VEGFR2. Dans les deux cas, l’inhalation de NO corrige les anomalies de myélinisation et d’angiogenèse induites par ces inhibiteurs. Nous avons soumis des ratons à une agression excitotoxique par injection intracérébrale d’agonistes du glutamate. A P10 les rats exposés au iNO avant l’injection présentent des lésions moins importantes ; ainsi qu’un diminution de densité des microglies activées et des astrocytes. Cet effet neuroprotecteur est associé à une régulation de sous-unités des récepteurs au glutamate dès P5. Cet effet transcriptionnel semble lié à la modulation de la signalisation pCREB/Akt. Les effets à distance du iNO sont liés à un transport réversible endovasculaire du NO. In fine, du NO est delivré à la cellule et les concentrations intracellaires de cGMP augmentent d’un facteur 5. Plusieurs facteurs de transcription sont régulés : PDGFR-α, Sema3F, les sous-unités des récepteurs au glutamate, Thrombospondine-1. Cette dernière est un antagoniste naturel de la signalisation NO-cGMP. L’injection de ABT-510, agoniste de TSP-1, abolit les effets du iNO, confirmant l’hypothèse que les effets à distance reposent sur la signalisation NO-Guanylate Cyclase soluble-cGMP. Au total, nous avons démontré que le iNO est transporté de manière réversible et delivré au cerveau en développement. Il y exerce un effet pro-angiogénique et pro-myélinisant, via une signalisation cGMP, régulée par la thrombospondine-1. Plus encore, l’exposition prophylactique au iNO diminue l’impact d’une agression excitotoxique. Ce qui augure de propriétés neuroprotectrices prometteuses en néonatalogie, et au delà.Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates, but littlei known about its effect on the developing brain. We explored the effects of iNO on developing brain in rodent pups, and pathway involved in iNO remote effects. Rat pups and their mothers were placed in a chamber containing 5 to 20 ppm of NO for 7 days after birth. Extensive serum analysis, immunochemistry, RT-PCR analysis, were performed Neonatal exposure to iNO was associated with a transient increase in central nervous system myelination and angiogenesis in rats, without any behavioral consequences in adulthood. Exposure to iNO was associated with a proliferative effect on immature oligodendrocytes and a subsequent promaturational effect. The role of endogenous NO in myelination was investigated in animals treated with the nitric oxides synthase inhibitor N-nitro-L- arginine methyl ester (L-NAME) in the neonatal period ; this led to protracted myelination defects and subsequent behavioral deficits in adulthood. These effects were reversed by rescuing L-NAME-treated animals with iNO. We challenged animals with intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significantdecrease of several glutamate receptor subunits expression at P5. iNO was associated with an early(P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt proteinconcentration in response to excitotoxic challenge (P7) Those effects were related to a release of NOto the cells, and a rise of cGMP intracellular concentration. Several transcription factor wereregulated, namely PDGFR-α, Sema3F, TSP-1, glutamate receptors subunits, Thrombospondin-1. Thelatter was responsible for NO pathway regulation, and injection of TSP-1 agonist (AbT-510) abolishediNO remote effects. iNO remote effects are not associated VEGF concentration increase nor VEGFRstimulation, as VEGF-R antagonist SU54-16 failed to abolish iNO effects on angiogenesis andmyelination. Moreover iNO reverses severe myelination and angiogenesis defects induced by this SU-5416. Thus, we demonstrate transport and considerable remote effect of iNO on angiogenesis andmyelination in rodents. Those effects are related to an enhancement of cGMP pathway, regulated byTSP-1, and transcriptional effects. Moreover we described and investigated the neuroprotectiveeffect of iNO in neonatal excitotoxic-induced brain damage. These data point to potential newavenues for neuroprotection in human perinatal brain damage

Effets du monoxyde d'azote inhalé sur le cerveau en développement chez le raton

Inhaled nitric oxide (iNO) is one of the most promising therapies used in neonates, but littlei known about its effect on the developing brain. We explored the effects of iNO on developing brain in rodent pups, and pathway involved in iNO remote effects. Rat pups and their mothers were placed in a chamber containing 5 to 20 ppm of NO for 7 days after birth. Extensive serum analysis, immunochemistry, RT-PCR analysis, were performed Neonatal exposure to iNO was associated with a transient increase in central nervous system myelination and angiogenesis in rats, without any behavioral consequences in adulthood. Exposure to iNO was associated with a proliferative effect on immature oligodendrocytes and a subsequent promaturational effect. The role of endogenous NO in myelination was investigated in animals treated with the nitric oxides synthase inhibitor N-nitro-L- arginine methyl ester (L-NAME) in the neonatal period ; this led to protracted myelination defects and subsequent behavioral deficits in adulthood. These effects were reversed by rescuing L-NAME-treated animals with iNO. We challenged animals with intracranial injection of glutamate agonists. At P10, rat pups exposed to iNO exhibited a significant decrease of lesion size in both the white matter and cortical plate compared to controls. Microglia activation and astrogliosis were found significantly decreased in NO-exposed animals. This neuroprotective effect was associated with a significantdecrease of several glutamate receptor subunits expression at P5. iNO was associated with an early(P1) downregulation of pCREB/pAkt expression and induced an increase in pAkt proteinconcentration in response to excitotoxic challenge (P7) Those effects were related to a release of NOto the cells, and a rise of cGMP intracellular concentration. Several transcription factor wereregulated, namely PDGFR-α, Sema3F, TSP-1, glutamate receptors subunits, Thrombospondin-1. Thelatter was responsible for NO pathway regulation, and injection of TSP-1 agonist (AbT-510) abolishediNO remote effects. iNO remote effects are not associated VEGF concentration increase nor VEGFRstimulation, as VEGF-R antagonist SU54-16 failed to abolish iNO effects on angiogenesis andmyelination. Moreover iNO reverses severe myelination and angiogenesis defects induced by this SU-5416. Thus, we demonstrate transport and considerable remote effect of iNO on angiogenesis andmyelination in rodents. Those effects are related to an enhancement of cGMP pathway, regulated byTSP-1, and transcriptional effects. Moreover we described and investigated the neuroprotectiveeffect of iNO in neonatal excitotoxic-induced brain damage. These data point to potential newavenues for neuroprotection in human perinatal brain damage.L’inhalation de monoxyde d’azote (NO) est l’une des thérapies les plus utilisées en réanimation néonatale. Cependant, peu de données sont disponibles sur l’impact de l’inhalation de NO sur le développement cérébral et le devenir des enfants prématurés. Nous avons étudié l’impact du monoxyde d’azote inhalé (iNO) sur le cerveau en développement chez le rongeur. Des portées et leur mère sont placés sous 5 à 20 ppm de NO de la naissance (P0) jusqu’au 7ème jour de vie postnatal (P7). Les animaux exposés au NO présentent une augmentation transitoire de l’angiogenèse et de la myélinisation, sans incidence sur les fonctions cognitives à l’âge adulte. L’exposition au NO est associée à une prolifération d’oligodendrocytes immatures et à une maturation anticipée des formes myélinisantes. Les rôles du NO endogène et du couple VEGF/VEGFR2 dans ces effets ont été évalués via l’injection d’antagonistes : LNAME pour inhiber les NOS, SU-5416 comme antagoniste du VEGFR2. Dans les deux cas, l’inhalation de NO corrige les anomalies de myélinisation et d’angiogenèse induites par ces inhibiteurs. Nous avons soumis des ratons à une agression excitotoxique par injection intracérébrale d’agonistes du glutamate. A P10 les rats exposés au iNO avant l’injection présentent des lésions moins importantes ; ainsi qu’un diminution de densité des microglies activées et des astrocytes. Cet effet neuroprotecteur est associé à une régulation de sous-unités des récepteurs au glutamate dès P5. Cet effet transcriptionnel semble lié à la modulation de la signalisation pCREB/Akt. Les effets à distance du iNO sont liés à un transport réversible endovasculaire du NO. In fine, du NO est delivré à la cellule et les concentrations intracellaires de cGMP augmentent d’un facteur 5. Plusieurs facteurs de transcription sont régulés : PDGFR-α, Sema3F, les sous-unités des récepteurs au glutamate, Thrombospondine-1. Cette dernière est un antagoniste naturel de la signalisation NO-cGMP. L’injection de ABT-510, agoniste de TSP-1, abolit les effets du iNO, confirmant l’hypothèse que les effets à distance reposent sur la signalisation NO-Guanylate Cyclase soluble-cGMP. Au total, nous avons démontré que le iNO est transporté de manière réversible et delivré au cerveau en développement. Il y exerce un effet pro-angiogénique et pro-myélinisant, via une signalisation cGMP, régulée par la thrombospondine-1. Plus encore, l’exposition prophylactique au iNO diminue l’impact d’une agression excitotoxique. Ce qui augure de propriétés neuroprotectrices prometteuses en néonatalogie, et au delà

Electroencéphalogramme d'amplitude chez le prématuré. Etude des tracés de la première semaine de vie et corrélation au devenir

REIMS-BU Santé (514542104) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Amplitude-Integrated EEG Monitoring in Pediatric Intensive Care: Prognostic Value in Meningitis before One Year of Age

Pediatric morbidity from meningitis remains considerable. Preventing complications is a major challenge to improve neurological outcome. Seizures may reveal the meningitis itself or some complications of this disease. Amplitude-integrated electroencephalography (aEEG) is gaining interest for the management of patients with acute neurological distress, beyond the neonatal age. This study aimed at evaluating the predictive value of aEEG monitoring during the acute phase in meningitis among a population of infants hospitalized in the pediatric intensive care unit (PICU), and at assessing the practicability of the technique. AEEG records of 25 infants younger than one year of age hospitalized for meningitis were retrospectively analyzed and correlated to clinical data and outcome. Recording was initiated, on average, within the first six hours for n = 18 (72%) patients, and overall quality was considered as good. Occurrence of seizure, of status epilepticus, and the background pattern were significantly associated with unfavorable neurological outcomes. AEEG may help in the management and prognostic assessment of pediatric meningitis. It is an easily achievable, reliable technique, and allows detection of subclinical seizures with minimal training. However, it is important to consider the limitations of aEEG, and combinate it with conventional EEG for the best accuracy