NDP-MSH binding melanocortin-1 receptor ameliorates neuroinflammation and BBB disruption through CREB/Nr4a1/NF-κB pathway after intracerebral hemorrhage in mice

Abstract

BackgroundNeuroinflammation and blood-brain barrier (BBB) disruption are two vital mechanisms of secondary brain injury following intracerebral hemorrhage (ICH). Recently, melanocortin-1 receptor (Mc1r) activation by Nle4-D-Phe7-α-MSH (NDP-MSH) was shown to play a neuroprotective role in an experimental autoimmune encephalomyelitis (EAE) mouse model. This study aimed to investigate whether NDP-MSH could alleviate neuroinflammation and BBB disruption after experimental ICH, as well as the potential mechanisms of its neuroprotective roles.MethodsTwo hundred and eighteen male C57BL/6 mice were subjected to autologous blood-injection ICH model. NDP-MSH, an agonist of Mc1r, was administered intraperitoneally injected at 1 h after ICH insult. To further explore the related protective mechanisms, Mc1r small interfering RNA (Mc1r siRNA) and nuclear receptor subfamily 4 group A member 1 (Nr4a1) siRNA were administered via intracerebroventricular (i.c.v) injection before ICH induction. Neurological test, BBB permeability, brain water content, immunofluorescence staining, and Western blot analysis were implemented.ResultsThe Expression of Mc1r was significantly increased after ICH. Mc1r was mainly expressed in microglia, astrocytes, and endothelial cells following ICH. Treatment with NDP-MSH remarkably improved neurological function and reduced BBB disruption, brain water content, and the number of microglia in the peri-hematoma tissue after ICH. Meanwhile, the administration of NDP-MSH significantly reduced the expression of p-NF-κB p65, IL-1β, TNF-α, and MMP-9 and increased the expression of p-CREB, Nr4a1, ZO-1, occludin, and Lama5. Inversely, the knockdown of Mc1r or Nr4a1 abolished the neuroprotective effects of NDP-MSH.ConclusionsTaken together, NDP-MSH binding Mc1r attenuated neuroinflammation and BBB disruption and improved neurological deficits, at least in part through CREB/Nr4a1/NF-κB pathway after ICH.

Targeting connexin 43 provides anti-inflammatory effects after intracerebral hemorrhage injury by regulating YAP signaling

“…The method described above was used to prepare frozen sections on the third day after ICH in model mice or inoculated astrocytes, microglia, and neurons (which were seeded into the 24-well culture plate at 1.5 × 10 5 cells/well) for immunofluorescence staining [ 4 ]. After treatment, tissue sections and cells were incubated overnight with antibodies against GFAP (1:200, Cell Signaling Technology, #80788), Iba1 (1:100, Cell Signaling Technology, #17198), MAP-2 (1:50, SANTA CRUZ, sc-74421), or YAP (1:100, Cell Signaling Technology, #14074).…”

“…These activated astrocytes accumulate in the area surrounding the hematoma and can produce and release cytokines and chemokines, further aggravating the inflammatory responses. Recent studies have reported that inflammatory responses caused by reactive astrocytes play a key role in blood-brain barrier (BBB) destruction and neuronal apoptosis during ICH [ 4 ]. Under physiological and pathological conditions, astrocytes maintain communication with the neural microenvironment through gap junction channels (GJCs).…”

Inhibition of Histamine H3 receptor Attenuates Neuroinflammation and Cognitive Impairments in Alzheimer’s Disease via activating CREB Pathway

“…Expression of pro-in ammatory cytokines requires NF-κB activation and its nuclear translocation to interact with DNA [83]. Study indicates that activation of CREB induces reduced expression of p-NF-κB and decreased production of proin ammatory cytokines in brain injury [84]. We found a signi cant increase of p-P65 NF-κB phosphorylation in APP/PS1 Tg mice, suggesting that Aβ could activate NF-κB signaling pathway.…”

Metal ion-responsive nanocarrier derived from phosphonated calix[4]arenes for delivering dauricine specifically to sites of brain injury in a mouse model of intracerebral hemorrhage

“…The blunt end of this needle was inserted 3.9 mm ventral from the skull surface, relocated to 3.6 mm, and left in place for 7 min. After the waiting period, 10 μL of blood was infused, followed by an additional 5 min waiting period prior to a second infusion of 20 μL [22]. All injections were performed at 1.0 μL/min using an automated injector (Stoelting, Wood Dale, IL, USA).…”