| 1. |
- Koning, Gabriella, et al.
(författare)
-
Magnesium induces preconditioning of the neonatal brain via profound mitochondrial protection.
- 2019
-
Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 39:6, s. 1038-1055
-
Tidskriftsartikel (refereegranskat)abstract
- Magnesium sulphate (MgSO4) given to women in preterm labor reduces cerebral palsy in their offspring but the mechanism behind this protection is unclear, limiting its effective, safe clinical implementation. Previous studies suggest that MgSO4 is not neuroprotective if administered during or after the insult, so we hypothesised that MgSO4 induces preconditioning in the immature brain. Therefore, we administered MgSO4 at various time-points before/after unilateral hypoxia-ischemia (HI) in seven-day-old rats. We found that MgSO4 treatment administered as a bolus between 6 days and 12h prior to HI markedly reduced the brain injury, with maximal protection achieved by 1.1mg/g MgSO4 administered 24h before HI. As serum magnesium levels returned to baseline before the induction of HI, we ascribed this reduction in brain injury to preconditioning. Cerebral blood flow was unaffected, but mRNAs/miRNAs involved in mitochondrial function and metabolism were modulated by MgSO4. Metabolomic analysis (H+-NMR) disclosed that MgSO4 attenuated HI-induced increases in succinate and prevented depletion of high-energy phosphates. MgSO4 pretreatment preserved mitochondrial respiration, reducing ROS production and inflammation after HI. Therefore, we propose that MgSO4 evokes preconditioning via induction of mitochondrial resistance and attenuation of inflammation.
|
|
| 2. |
- Li, Hongfu, et al.
(författare)
-
Lithium-mediated long-term neuroprotection in neonatal rat hypoxia-ischemia is associated with antiinflammatory effects and enhanced proliferation and survival of neural stem/progenitor cells.
- 2011
-
Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016. ; 31:10, s. 2106-2115
-
Tidskriftsartikel (refereegranskat)abstract
- The aim of this study was to evaluate the long-term effects of lithium treatment on neonatal hypoxic-ischemic brain injury, inflammation, and neural stem/progenitor cell (NSPC) proliferation and survival. Nine-day-old male rats were subjected to unilateral hypoxia-ischemia (HI) and 2mmol/kg lithium chloride was injected intraperitoneally immediately after the insult. Additional lithium injections, 1mmol/kg, were administered at 24-hour intervals for 7 days. Animals were killed 6, 24, 72hours, or 7 weeks after HI. Lithium reduced total tissue loss by 69%, from 89.4±14.6mm(3) in controls (n=15) to 27.6±6.2mm(3) in lithium-treated animals (n=14) 7 weeks after HI (P<0.001). Microglia activation was inhibited by lithium treatment, as judged by Iba-1 and galectin-3 immunostaining, and reduced interleukin-1β and CCL2 levels. Lithium increased progenitor, rather than stem cell, proliferation in both nonischemic and ischemic brains, as judged by 5-bromo-2-deoxyuridine labeling 24 and 72hours as well as by phospho-histone H3 and brain lipid-binding protein labeling 7 weeks after HI. Lithium treatment also promoted survival of newborn NSPCs, without altering the relative levels of neuronal and astroglial differentiation. In summary, lithium conferred impressive, morphological long-term protection against neonatal HI, at least partly by inhibiting inflammation and promoting NSPC proliferation and survival.Journal of Cerebral Blood Flow & Metabolism advance online publication, 18 May 2011; doi:10.1038/jcbfm.2011.75.
|
|
| 3. |
- Mottahedin, Amin, et al.
(författare)
-
Systemic activation of Toll-like receptor 2 suppresses mitochondrial respiration and exacerbates hypoxic-ischemic injury in the developing brain
- 2017
-
Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 37:4, s. 1192-1198
-
Tidskriftsartikel (refereegranskat)abstract
- Infection and inflammation are known risk factors for neonatal brain injury. Mycoplasma and Gram-positive bacteria, for which Toll-like receptor 2 (TLR2) plays a key role in recognition and inflammatory response, are among the most common pathogens in the perinatal period. Here, we report that systemic activation of TLR2 by Pam3CSK4 (P3C) increases neural tissue loss and demyelination induced by subsequent hypoxia-ischemia (HI) in neonatal mice. High-resolution respirometry of brain isolated mitochondria revealed that P3C suppresses ADP-induced oxidative phosphorylation, the main pathway of cellular energy production. The results suggest that infection and inflammation might contribute to HI-induced energy failure.
|
|
| 4. |
- Qiu, L., et al.
(författare)
-
Less neurogenesis and inflammation in the immature than in the juvenile brain after cerebral hypoxia-ischemia
- 2007
-
Ingår i: J Cereb Blood Flow Metab. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 27:4, s. 785-94
-
Tidskriftsartikel (refereegranskat)abstract
- The effects of hypoxia-ischemia (HI) on proliferation and differentiation in the immature (postnatal day 9) and juvenile (postnatal day 21) mouse hippocampus were investigated by injecting bromodeoxyuridine (50 mg/kg) daily for 7 days after the insult and evaluating the labeling 5 weeks after HI. Phenotypic differentiation was evaluated using NeuN, Iba1, APC, and S100beta as markers of neurons, microglia, oligodendrocytes, and astrocytes, respectively. The basal proliferation, in particular neurogenesis, was higher in the immature than in the juvenile hippocampus. Hypoxia-ischemia did not increase neurogenesis significantly in the immature dentate gyrus (DG), but it increased several-fold in the juvenile brain, reaching the same level as in the normal, noninjured immature brain. This suggests that the immature hippocampus is already working at the top of its proliferative capacity and that even though basal neurogenesis decreased with age, the injury-induced generation of new neurons in the juvenile hippocampus could not increase beyond the basal level of the immature brain. Generation of glial cells of all three types after HI was significantly more pronounced in the cornu ammonis of the hippocampus region of the juvenile hippocampus. In the DG, only microglia production was greater in the juvenile brain. Increased microglia proliferation correlated with increased levels of the proinflammatory cytokines MCP-1 and IL-18 3 days after HI, indicating that the inflammatory response is stronger in the juvenile hippocampus. In summary, contrary to what has been generally assumed, our results indicate that the juvenile brain has a greater capacity for neurogenesis after injury than the immature brain.
|
|
| 5. |
- Song, Juan, et al.
(författare)
-
Temporal brain transcriptome analysis reveals key pathological events after germinal matrix hemorrhage in neonatal rats
- 2022
-
Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 42:9, s. 1632-1649
-
Tidskriftsartikel (refereegranskat)abstract
- Germinal matrix hemorrhage (GMH) is a common complication in preterm infants and is associated with high risk of adverse neurodevelopmental outcomes. We used a rat GMH model and performed RNA sequencing to investigate the signaling pathways and biological processes following hemorrhage. GMH induced brain injury characterized by early hematoma and subsequent tissue loss. At 6 hours after GMH, gene expression indicated an increase in mitochondrial activity such as ATP metabolism and oxidative phosphorylation along with upregulation of cytoprotective pathways and heme metabolism. At 24 hours after GMH, the expression pattern suggested an increase in cell cycle progression and downregulation of neurodevelopmental-related pathways. At 72 hours after GMH, there was an increase in genes related to inflammation and an upregulation of ferroptosis. Hemoglobin components and genes related to heme metabolism and ferroptosis such as Hmox1, Alox15, and Alas2 were among the most upregulated genes. We observed dysregulation of processes involved in development, mitochondrial function, cholesterol biosynthesis, and inflammation, all of which contribute to neurodevelopmental deterioration following GMH. This study is the first temporal transcriptome profile providing a comprehensive overview of the molecular mechanisms underlying brain injury following GMH, and it provides useful guidance in the search for therapeutic interventions.
|
|
| 6. |
- Zhang, X. L., et al.
(författare)
-
Germinal matrix hemorrhage induces immune responses, brain injury, and motor impairment in neonatal rats
- 2023
-
Ingår i: Journal of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 0271-678X .- 1559-7016. ; 43:2_suppl, s. 49-65
-
Tidskriftsartikel (refereegranskat)abstract
- Germinal matrix hemorrhage (GMH) is a major complication of prematurity that causes secondary brain injury and is associated with long-term neurological disabilities. This study used a postnatal day 5 rat model of GMH to explore immune response, brain injury, and neurobehavioral changes after hemorrhagic injury. The results showed that CD45(high)/CD11b(+) immune cells increased in the brain after GMH and were accompanied by increased macrophage-related chemokine/cytokines and inflammatory mediators. Hematoma formed as early as 2 h after injection of collagenase VII and white matter injury appeared not only in the external capsule and hippocampus, but also in the thalamus. In addition, GMH caused abnormal motor function as revealed by gait analysis, and locomotor hyperactivity in the elevated plus maze, though no other obvious anxiety or recognition/memory function changes were noted when examined by the open field test and novel object recognition test. The animal model used here partially reproduces the GMH-induced brain injury and motor dysfunction seen in human neonates and therefore can be used as a valid tool in experimental studies for the development of effective therapeutic strategies for GMH-induced brain injury.
|
|
| 7. |
- Zhu, Changlian, 1964, et al.
(författare)
-
Age-dependent regenerative responses in the striatum and cortex after hypoxia-ischemia.
- 2009
-
Ingår i: Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism. - : SAGE Publications. - 1559-7016. ; 29:2, s. 342-54
-
Tidskriftsartikel (refereegranskat)abstract
- Regenerative responses after hypoxia-ischemia (HI) were investigated in the immature (P9) and juvenile (P21) mouse striatum and cortex by postischemic 5-bromo-2-deoxyuridine labeling and phenotyping of labeled cells 4 weeks later. HI stimulated the formation of new cells in striatum and cortex in immature, growing brains (P9), but when brain growth was finished (P21) proliferation could be stimulated only in striatum, not in cortex. However, the relative increase was higher in P21 (460%) than P9 striatum (50%), though starting from a lower level at P21. Starting from this lower level, HI-induced proliferation in P21 striatum reached the same level as in P9 striatum, but not higher. Phenotyping revealed that low levels of neurogenesis were still present in nonischemic P9 cortex and striatum, but only in striatum at P21. Ischemia-induced neurogenesis was found only in P9 striatum. Ischemia-induced gliogenesis occurred in P9 and P21 striatum as well as P9 cortex, but not in P21 cortex. Hence, the regenerative response was stronger in striatum than cortex, and stronger in P9 than P21 cortex. The biggest ischemia-induced change was the 49-fold increase in P21 striatal microglia, and this was accompanied by increased inflammation, as judged by the size and numbers of CCL2- and interleukin-18-positive cells.Journal of Cerebral Blood Flow & Metabolism advance online publication, 5 November 2008; doi:10.1038/jcbfm.2008.124.
|
|
