Molecular neurobiology
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Molecular neurobiology · Aug 2016
Hydrogen Sulfide Ameliorates Early Brain Injury Following Subarachnoid Hemorrhage in Rats.
Increasing studies have demonstrated the neuroprotective effect of hydrogen sulfide (H2S) in central nervous system (CNS) diseases. However, the potential application value of H2S in the therapy of subarachnoid hemorrhage (SAH) is still not well known. This study was to investigate the potential effect of H2S on early brain injury (EBI) induced by SAH and explore the underlying mechanisms. ⋯ More importantly, NaHS treatment could significantly attenuate EBI (including brain edema, blood-brain barrier disruption, brain cell apoptosis, inflammatory response, and cerebral vasospasm) after SAH. In vitro, H2S protects neurons and endothelial function by functioning as an antioxidant and antiapoptotic mediator. Our results suggest that NaSH as an exogenous H2S donor could significantly reduce EBI induced by SAH.
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Molecular neurobiology · Aug 2016
Signaling Mechanism of Cannabinoid Receptor-2 Activation-Induced β-Endorphin Release.
Activation of cannabinoid receptor-2 (CB2) results in β-endorphin release from keratinocytes, which then acts on primary afferent neurons to inhibit nociception. However, the underlying mechanism is still unknown. The CB2 receptor is generally thought to couple to Gi/o to inhibit cAMP production, which cannot explain the peripheral stimulatory effects of CB2 receptor activation. ⋯ Using a rat model of inflammatory pain, we showed that the MAPK kinase inhibitor PD98059 abolished the peripheral effect of the CB2 receptor agonist on nociception. We thus present a novel mechanism of CB2 receptor activation-induced β-endorphin release through Gi/o-Gβγ-MAPK-Ca(2+) signaling pathway. Our data also suggest that stimulation of MAPK contributes to the peripheral analgesic effect of CB2 receptor agonists.
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Molecular neurobiology · Jul 2016
Hydrogen-Rich Saline Attenuated Subarachnoid Hemorrhage-Induced Early Brain Injury in Rats by Suppressing Inflammatory Response: Possible Involvement of NF-κB Pathway and NLRP3 Inflammasome.
Early brain injury (EBI), highlighted with inflammation and apoptosis, occurring within 72 h after subarachnoid hemorrhage (SAH), is associated with the prognosis of SAH. Recent studies have revealed that hydrogen-rich saline (HS) exerted multiple neuroprotective properties in many neurological diseases including SAH, involved to anti-oxidative and anti-apoptotic effect. We have previously reported that HS could attenuate neuronal apoptosis as well as vasospasm. ⋯ Finally, activation of NF-κB pathway and NLRP3 inflammasome contribute to the inflammation response and cellular injury in EBI after SAH. HS treatment reversed the detrimental effect mentioned above via inactivation of NF-κB pathway and NLRP3 inflammasome. NF-κB nuclear factor-κB, IκB inhibitor of NF-κB, IKK Iκ kinase, NLRP3 nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3, ASC apoptosis-associated speck-like protein containing a caspase recruitment domain.
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Molecular neurobiology · May 2016
Calpain-Dependent ErbB4 Cleavage Is Involved in Brain Ischemia-Induced Neuronal Death.
Disturbance of neuregulin-1β/ErbB4 signaling is considered to be associated with brain ischemia, but the mechanisms of this disruption are largely unknown. In the present study, we provide evidence that degradation of ErbB4 is involved in neuronal cell death in response to ischemia. Our data showed that the application of neuregulin-1β provided significant protection against oxygen-glucose deprivation (OGD)-induced neuronal death as detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, annexin V/propidium iodide flow cytometry analysis and terminal deoxynucleotidyl transferase (TdT) dUTP nick end labeling (TUNEL) staining. ⋯ In vitro studies further indicated that recombinant calpain induced the cleavage of ErbB4 in a dose-dependent way, whereas the calpain inhibitor significantly reduced the OGD-induced ErbB4 breakdown. Additionally, OGD-induced apoptosis was partially abolished by transfection with the ErbB4E872K mutant. Taken together, neuregulin-1β elicits its neuroprotective effect in an ErbB4-dependent manner, and the cleavage of ErbB4 by calpain contributes to a neuronal cell death cascade during brain ischemia.
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Molecular neurobiology · May 2016
Meta AnalysisHyperglycemia and Mortality Risk in Patients with Primary Intracerebral Hemorrhage: A Meta-Analysis.
Hyperglycemia may be associated with worse functional outcomes in patients with primary intracerebral hemorrhage. We performed a systematic review and meta-analysis to investigate the relationship between hyperglycemia and mortality risk in patients with primary intracerebral hemorrhage. We searched PubMed and Embase databases for studies investigating the association between hyperglycemia and mortality risk in patients with primary intracerebral hemorrhage. ⋯ Subgroup analysis by time of follow-up showed that hyperglycemia significantly increased risk of short-term mortality (RR = 3.97, 95% CI 2.13-7.43) and long-term mortality (RR = 1.53, 95% CI 1.14-2.05). The RR of mortality for per 1-mmol/L increment in glucose level was 1.14 (95% CI 1.06-1.22). In patients with primary intracerebral hemorrhage, hyperglycemia significantly increases risk of both short-term mortality and long-term mortality.