Neuroprotection of minocycline by inhibition of extracellular matrix metalloproteinase inducer expression following intracerebral hemorrhage in mice.

Intracerebral hemorrhage (ICH) is a severe neurological dysfunction and a medical emergency with a high mortality rate. Minocycline ameliorates deficits in rodent models of acute and chronic neurological diseases. However, the role of minocycline in ICH remains unclear. The extracellular matrix metalloproteinase inducer (EMMPRIN) is a key inflammatory mediator in some neurological diseases, triggering matrix metalloproteinases (MMPs) production. In this study, we aimed to use minocycline to inhibit EMMPRIN and thus the activity of MMPs. Male adult C57BL/6 mice were injected with collagenase type VII or saline into the right basal ganglia and euthanized at different time points. The minocycline was intraperitoneally injected once every 12 h for three days to block the expression of EMMPRIN from two hours after ICH. We found that breakdown of the BBB was most severe 3 days after ICH. The minocycline treatment significantly decreased EMMPRIN and MMP-9 expression, reduced zonula occludens-1 and occludin, and alleviated BBB disruption. Moreover, minocycline treatment displayed a lower brain water content, lesser neurological dysfunction, and smaller injury volume on day 3 than those of the vehicle-treated group. Minocycline also inhibited the activation of microglia/macrophages, infiltration of neutrophils, and production of inflammatory mediators, including tumor necrosis factor alpha and interleukin-1beta. The current study shows that minocycline exhibits protective roles in ICH by decreasing EMMPRIN and MMP-9 expression, alleviating BBB disruption, inhibiting neuroinflammation, areducing neuronal degeneration and death.

Liu Y ，Li Z ，Khan S ，Zhang R ，Wei R ，Zhang Y ，Xue M ，Yong VW ... -  《-》

Neuroprotective Effects of Chlorogenic Acid in a Mouse Model of Intracerebral Hemorrhage Associated with Reduced Extracellular Matrix Metalloproteinase Inducer.

Liu Y ，Wang F ，Li Z ，Mu Y ，Yong VW ，Xue M ... -  《-》

EMMPRIN Promotes the Expression of MMP-9 and Exacerbates Neurological Dysfunction in a Mouse Model of Intracerebral Hemorrhage.

Extracellular matrix metalloproteinase inducer (EMMPRIN) has been shown to be a vital inflammatory mediator in several neurological and neurodegenerative diseases. However, the role of EMMPRIN in intracerebral hemorrhage (ICH) remains unexplored. In this study, we aimed to exploit a highly selective monoclonal anti-EMMPRIN antibody to functionally inhibit EMMPRIN activity and thus that of MMPs as the downstream effector. To induce ICH pathology, adult C57BL/6 male mice were injected with collagenase type VII or saline as control into the right basal ganglia and were euthanized at different time points. The anti-EMMPRIN monoclonal antibody was intravenously injected once daily for 3 days to block the expression of EMMPRIN initiating at 4 h post-ICH. Western blot and immunofluorescence analysis results revealed that EMMPRIN expression was significantly increased surrounding the hematoma at 3 and 7 d time points after ICH when compared to the saline treated control group. EMMPRIN expression was co-localized with GFAP (astrocytes) and Iba1 (microglia) at 3 d time point post-ICH, but not in the control group mice. The co-localization of EMMPRIN with CD31 in endothelial cells occurred in both groups and was higher in the ICH brain. However, EMMPRIN expression was not detected in neurons from either group. The inhibition of EMMPRIN reduced the expression of MMP-9, the number of infiltrated neutrophils, the degree of brain injury and promoted neurological recovery after ICH. In conclusion, EMMPRIN could mediate the upregulation of MMP-9 and exacerbate neurological dysfunction in a mouse model of experimental ICH. Furthermore, blocking EMMPRIN reduced brain injury and subsequently promoted neurological recovery in ICH mice brains. These outcomes highlight that inhibition of EMMPRIN can be a potential therapeutic intervention strategy to regulate MMP-9's pathological roles during ICH.

Liu Y ，Bai Q ，Yong VW ，Xue M ... -  《-》

Minocycline Preserves the Integrity and Permeability of BBB by Altering the Activity of DKK1-Wnt Signaling in ICH Model.

Disruption of the blood-brain barrier (BBB) and subsequent neurological deficits are the most severe consequence of intracerebral hemorrhage (ICH). Minocycline has been wildly used clinically as a neurological protective agent in clinical practice. However, the underlying mechanisms by which minocycline functions remain unclear. Therefore, we assessed the influence of minocycline on BBB structure, neurological function, and inflammatory responses in a collagenase-induced ICH model, and elucidated underlying molecular mechanisms as well. Following a single injection of collagenase VII-S into the basal ganglia, BBB integrity was assessed by Evans blue extravasation while neurological function was assessed using an established neurologic function scoring system. Minocycline treatment significantly alleviated the severity of BBB disruption, brain edema, and neurological deficits in ICH model. Moreover, minocycline decreased the production of inflammatory mediators including TNF, IL-6, and MMP-9, by microglia. Minocycline treatment decreased DKK1 expression but increased Wnt1, β-catenin and Occludin, a phenomenon mimicked by DKK1 silencing. These data suggest that minocycline improves the consequences of ICH by preserving BBB integrity and attenuating neurologic deficits in a DKK1-related manner that involves enhancement of the Wnt1-β-catenin activity.

Wang G ，Li Z ，Li S ，Ren J ，Suresh V ，Xu D ，Zang W ，Liu X ，Li W ，Wang H ，Guo F ... -  《-》

Adjudin protects blood-brain barrier integrity and attenuates neuroinflammation following intracerebral hemorrhage in mice.

Secondary brain injury exacerbates neurological dysfunction and neural cell death following intracerebral hemorrhage (ICH), targeting the pathophysiological mechanism of the secondary brain injury holds promise for improving ICH outcomes. Adjudin, a potential male contraceptive, exhibits neuroprotective effects in brain injury disease models, yet its impact in the ICH model remains unknown. In this study, we investigated the effects of adjudin on brain injury in a mouse ICH model and explored its underlying mechanisms. ICH was induced in male C57BL/6 mice by injecting collagenase into the right striatum. Mice received adjudin treatment (50 mg/kg/day) for 3 days before euthanization and the perihematomal tissues were collected for further analysis. Adjudin significantly reduced hematoma volume and improved neurological function compared with the vehicle group. Western blot showed that Adjudin markedly decreased the expression of MMP-9 and increased the expression of tight junctions (TJs) proteins, Occludin and ZO-1, and adherens junctions (AJs) protein VE-cadherin. Adjudin also decreased the blood-brain barrier (BBB) permeability, as indicated by the reduced albumin and Evans Blue leakage, along with a decrease in brain water content. Immunofluorescence staining revealed that adjudin noticeably reduced the infiltration of neutrophil, activation of microglia/macrophages, and reactive astrogliosis, accompanied by an increase in CD206 positive microglia/macrophages which exhibit phagocytic characteristics. Adjudin concurrently decreased the generation of proinflammatory cytokines, such as TNF-α and IL-1β. Additionally, adjudin increased the expression of aquaporin 4 (AQP4). Furthermore, adjudin reduced brain cell apoptosis, as evidenced by increased expression of anti-apoptotic protein Bcl-2, and decreased expression of apoptosis related proteins Bax, cleaved caspase-3 and fewer TUNEL positive cells. Our data suggest that adjudin protects against ICH-induced secondary brain injury and may serve as a potential neuroprotective agent for ICH treatment.

Su Q ，Su C ，Zhang Y ，Guo Y ，Liu Y ，Liu Y ，Yong VW ，Xue M ... -  《-》