Roscovitine Attenuates Microglia Activation and Monocyte Infiltration via p38 MAPK Inhibition in the Rat Frontoparietal Cortex Following Status Epilepticus

Under physiological conditions, microglia are unique immune cells resident in the brain that is isolated from the systemic immune system by brain-blood barrier. Following status epilepticus (SE, a prolonged seizure activity), microglia are rapidly activated and blood-derived monocytes that infiltrate the brain; therefore, the regulations of microglia activation and monocyte infiltration are one of the primary therapeutic strategies for inhibition of undesirable consequences from SE. Roscovitine, a potent (but not selective) cyclin-dependent kinase 5 (CDK5) inhibitor, has been found to exert anti-inflammatory and microglia-inhibiting actions in several in vivo models, although the underlying mechanisms have not been clarified. In the present study, roscovitine attenuated SE-induces monocyte infiltration without vasogenic edema formation in the frontoparietal cortex (FPC), accompanied by reducing expressions of monocyte chemotactic protein-1 (MCP-1) and lysosome-associated membrane protein 1 (LAMP1) in resident microglia, while it did not affect microglia transformation to amoeboid form. Furthermore, roscovitine ameliorated the up-regulation of p38 mitogen-activated protein kinase (p38 MAPK) phosphorylation, but not nuclear factor-κB-S276 phosphorylation. Similar to roscovitine, SB202190, a p38 MAPK inhibitor, mitigated monocyte infiltration and microglial expressions of MCP-1 and LAMP1 in the FPC following SE. Therefore, these findings suggest for the first time that roscovitine may inhibit SE-induced neuroinflammation via regulating p38 MAPK-mediated microglial responses.

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Leptomycin B ameliorates vasogenic edema formation induced by status epilepticus via inhibiting p38 MAPK/VEGF pathway

Brain Research ◽

10.1016/j.brainres.2016.09.023 ◽

2016 ◽

Vol 1651 ◽

pp. 27-35 ◽

Cited By ~ 11

Author(s):

Duk-Soo Kim ◽

Su-Ji Min ◽

Min-Ju Kim ◽

Ji-Eun Kim ◽

Tae-Cheon Kang

Keyword(s):

Status Epilepticus ◽

P38 Mapk ◽

Vasogenic Edema ◽

Leptomycin B ◽

Edema Formation ◽

Vegf Pathway

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Epigallocatechin-3-Gallate and PEDF 335 Peptide, 67LR Activators, Attenuate Vasogenic Edema, and Astroglial Degeneration Following Status Epilepticus

Antioxidants ◽

10.3390/antiox9090854 ◽

2020 ◽

Vol 9 (9) ◽

pp. 854

Author(s):

Ji-Eun Kim ◽

Hana Park ◽

Min-Jeong Jeong ◽

Tae-Cheon Kang

Keyword(s):

Status Epilepticus ◽

Vasogenic Edema ◽

Pigment Epithelium ◽

Piriform Cortex ◽

Nicotinamide Adenine Dinucleotide Phosphate ◽

Laminin Receptor ◽

Mitogen Activated Protein Kinase ◽

Edema Formation ◽

Aqp4 Expression ◽

Underlying Mechanisms

Non-integrin 67-kDa laminin receptor (67LR) is involved in cell adherence to the basement membrane, and it regulates the interactions between laminin and other receptors. The dysfunction of 67LR leads to serum extravasation via blood-brain barrier (BBB) disruption. Polyphenol (–)-epigallocatechin-3-O-gallate (EGCG) and pigment epithelium-derived factor (PEDF) bind to 67LR and inhibit neovascularization. Therefore, in the present study, we investigated the effects of EGCG and NU335, a PEDF-derive peptide, on BBB integrity and their possible underlying mechanisms against vasogenic edema formation induced by status epilepticus (SE, a prolonged seizure activity). Following SE, both EGCG and NU335 attenuated serum extravasation and astroglial degeneration in the rat piriform cortex (PC). Both EGCG and NU335 reversely regulated phosphatidylinositol 3 kinase (PI3K)/AKT–eNOS (endothelial nitric oxide synthase) mediated BBB permeability and aquaporin 4 (AQP4) expression in endothelial cells and astrocytes through the p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways, respectively. Furthermore, EGCG and NU335 decreased p47Phox (a nicotinamide adenine dinucleotide phosphate oxidase subunit) expression in astrocytes under physiological and post-SE conditions. Therefore, we suggest that EGCG and PEDF derivatives may activate 67LR and its downstream effectors, and they may be considerable anti-vasogenic edema agents.

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Blockade of 67-kDa Laminin Receptor Facilitates AQP4 Down-Regulation and BBB Disruption via ERK1/2-and p38 MAPK-Mediated PI3K/AKT Activations

Cells ◽

10.3390/cells9071670 ◽

2020 ◽

Vol 9 (7) ◽

pp. 1670

Author(s):

Ji-Eun Kim ◽

Hana Park ◽

Ji-Eun Lee ◽

Tae-Cheon Kang

Keyword(s):

Endothelial Cells ◽

Signaling Pathways ◽

P38 Mapk ◽

Neurological Diseases ◽

Vasogenic Edema ◽

Water Channel ◽

Laminin Receptor ◽

Mitogen Activated Protein Kinase ◽

Edema Formation ◽

Aqp4 Expression

Recently, we have reported that dysfunctions of 67-kDa laminin receptor (67LR) induced by status epilepticus (SE, a prolonged seizure activity) and 67LR neutralization are involved in vasogenic edema formation, accompanied by the reduced aquaporin 4 (AQP4, an astroglial specific water channel) expression in the rat piriform cortex (PC). In the present study, we found that the blockade of 67LR activated p38 mitogen-activated protein kinase (p38 MAPK) and extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathways, which enhanced phosphatidylinositol 3 kinase (PI3K)/AKT phosphorylations in endothelial cells and astrocytes, respectively. 67LR-p38 MAPK-PI3K-AKT activation in endothelial cells increased vascular permeability. In contrast, 67LR-ERK1/2-PI3K-AKT signaling pathways in astrocytes regulated astroglial viability and AQP4 expression. These findings indicate that PI3K/AKT may integrate p38 MAPK and ERK1/2 signaling pathways to regulate AQP4 expression when 67LR functionality is reduced. Thus, we suggest that 67LR-p38 MAPK/ERK1/2-PI3K-AKT-AQP4 signaling cascades may mediate serum extravasation and AQP4 expression in astroglio-vascular systems, which is one of the considerable therapeutic targets for vasogenic edema in various neurological diseases.

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A novel vasculo-angiogenic effect of cilostazol mediated by cross-talk between multiple signalling pathways including the ERK/p38 MAPK signalling transduction cascade

Clinical Science ◽

10.1042/cs20110432 ◽

2012 ◽

Vol 123 (3) ◽

pp. 147-159 ◽

Cited By ~ 15

Author(s):

Ting-Hsing Chao ◽

Shih-Ya Tseng ◽

Yi-Heng Li ◽

Ping-Yen Liu ◽

Chung-Lung Cho ◽

...

Keyword(s):

Protein Kinase ◽

P38 Mapk ◽

Umbilical Vein ◽

Tube Formation ◽

Mitogen Activated Protein Kinase ◽

Signalling Pathways ◽

No Production ◽

Angiogenic Effect

Cilostazol is an anti-platelet agent with vasodilatory activity that acts by increasing intracellular concentrations of cAMP. Recent reports have suggested that cilostazol may promote angiogenesis. In the present study, we have investigated the effect of cilostazol in promoting angiogenesis and vasculogenesis in a hindlimb ischaemia model and have also examined its potential mechanism of action in vitro and in vivo. We found that cilostazol treatment significantly increased colony formation by human early EPCs (endothelial progenitor cells) through a mechanism involving the activation of cAMP/PKA (protein kinase A), PI3K (phosphoinositide 3-kinase)/Akt/eNOS (endothelial NO synthase) and ERK (extracellular-signal-regulated kinase)/p38 MAPK (mitogen-activated protein kinase) signalling pathways. Cilostazol also enhanced proliferation, chemotaxis, NO production and vascular tube formation in HUVECs (human umbilical vein endothelial cells) through activation of multiple signalling pathways downstream of PI3K/Akt/eNOS. Cilostazol up-regulated VEGF (vascular endothelial growth factor)-A165 expression and secretion of VEGF-A in HUVECs through activation of the PI3K/Akt/eNOS pathway. In a mouse hindlimb ischaemia model, recovery of blood flow ratio (ipsilateral/contralateral) 14 days after surgery was significantly improved in cilostazol-treated mice (10 mg/kg of body weight) compared with vehicle-treated controls (0.63±0.07 and 0.43±0.05 respectively, P<0.05). Circulating CD34+ cells were also increased in cilostazol-treated mice (3614±670 compared with 2151±608 cells/ml, P<0.05). Expression of VEGF and phosphorylation of PI3K/Akt/eNOS and ERK/p38 MAPK in ischaemic muscles were significantly enhanced by cilostazol. Our data suggest that cilostazol produces a vasculo-angiogenic effect by up-regulating a broad signalling network that includes the ERK/p38 MAPK, VEGF-A165, PI3K/Akt/eNOS and cAMP/PKA pathways.

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Vascular Dysfunction Induced by Mercury Exposure

International Journal of Molecular Sciences ◽

10.3390/ijms20102435 ◽

2019 ◽

Vol 20 (10) ◽

pp. 2435 ◽

Cited By ~ 4

Author(s):

Tetsuya Takahashi ◽

Takayoshi Shimohata

Keyword(s):

Oxidative Stress ◽

Vascular Dysfunction ◽

Brain Parenchyma ◽

Transport Systems ◽

Mehg Exposure ◽

In Vivo Models ◽

The Central Nervous System ◽

The Brain

Methylmercury (MeHg) causes severe damage to the central nervous system, and there is increasing evidence of the association between MeHg exposure and vascular dysfunction, hemorrhage, and edema in the brain, but not in other organs of patients with acute MeHg intoxication. These observations suggest that MeHg possibly causes blood–brain barrier (BBB) damage. MeHg penetrates the BBB into the brain parenchyma via active transport systems, mainly the l-type amino acid transporter 1, on endothelial cell membranes. Recently, exposure to mercury has significantly increased. Numerous reports suggest that long-term low-level MeHg exposure can impair endothelial function and increase the risks of cardiovascular disease. The most widely reported mechanism of MeHg toxicity is oxidative stress and related pathways, such as neuroinflammation. BBB dysfunction has been suggested by both in vitro and in vivo models of MeHg intoxication. Therapy targeted at both maintaining the BBB and suppressing oxidative stress may represent a promising therapeutic strategy for MeHg intoxication. This paper reviews studies on the relationship between MeHg exposure and vascular dysfunction, with a special emphasis on the BBB.

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Cerebral Edema Formation After Stroke: Emphasis on Blood–Brain Barrier and the Lymphatic Drainage System of the Brain

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2021.716825 ◽

2021 ◽

Vol 15 ◽

Author(s):

Sichao Chen ◽

Linqian Shao ◽

Li Ma

Keyword(s):

Blood Brain Barrier ◽

Cerebral Edema ◽

Lymphatic System ◽

Vasogenic Edema ◽

Lymphatic Vessels ◽

Drainage System ◽

Brain Barrier ◽

Edema Formation ◽

Blood Brain ◽

The Brain

Brain edema is a severe stroke complication that is associated with prolonged hospitalization and poor outcomes. Swollen tissues in the brain compromise cerebral perfusion and may also result in transtentorial herniation. As a physical and biochemical barrier between the peripheral circulation and the central nervous system (CNS), the blood–brain barrier (BBB) plays a vital role in maintaining the stable microenvironment of the CNS. Under pathological conditions, such as ischemic stroke, the dysfunction of the BBB results in increased paracellular permeability, directly contributing to the extravasation of blood components into the brain and causing cerebral vasogenic edema. Recent studies have led to the discovery of the glymphatic system and meningeal lymphatic vessels, which provide a channel for cerebrospinal fluid (CSF) to enter the brain and drain to nearby lymph nodes and communicate with the peripheral immune system, modulating immune surveillance and brain responses. A deeper understanding of the function of the cerebral lymphatic system calls into question the known mechanisms of cerebral edema after stroke. In this review, we first discuss how BBB disruption after stroke can cause or contribute to cerebral edema from the perspective of molecular and cellular pathophysiology. Finally, we discuss how the cerebral lymphatic system participates in the formation of cerebral edema after stroke and summarize the pathophysiological process of cerebral edema formation after stroke from the two directions of the BBB and cerebral lymphatic system.

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Modulator of apoptosis-1 is a potential therapeutic target in acute ischemic injury

Journal of Cerebral Blood Flow & Metabolism ◽

10.1177/0271678x18794839 ◽

2018 ◽

Vol 39 (12) ◽

pp. 2406-2418 ◽

Cited By ~ 3

Author(s):

Su Jing Chan ◽

Hui Zhao ◽

Kazuhide Hayakawa ◽

Chou Chai ◽

Chong Teik Tan ◽

...

Keyword(s):

Cortical Neurons ◽

Infarct Volume ◽

Neuronal Loss ◽

Ischemic Injury ◽

Glucose Deprivation ◽

Artery Occlusion ◽

In Vivo Models ◽

The Brain

Modulator of apoptosis 1 (MOAP-1) is a Bax-associating protein highly enriched in the brain. In this study, we examined the role of MOAP-1 in promoting ischemic injuries following a stroke by investigating the consequences of MOAP-1 overexpression or deficiency in in vitro and in vivo models of ischemic stroke. MOAP-1 overexpressing SH-SY5Y cells showed significantly lower cell viability following oxygen and glucose deprivation (OGD) treatment when compared to control cells. Consistently, MOAP-1−/− primary cortical neurons were observed to be more resistant against OGD treatment than the MOAP-1+/+ primary neurons. In the mouse transient middle cerebral artery occlusion (tMCAO) model, ischemia triggered MOAP-1/Bax association, suggested activation of the MOAP-1-dependent apoptotic cascade. MOAP-1−/− mice were found to exhibit reduced neuronal loss and smaller infarct volume 24 h after tMCAO when compared to MOAP-1+/+ mice. Correspondingly, MOAP-1−/− mice also showed better integrity of neurological functions as demonstrated by their performance in the rotarod test. Therefore, both in vitro and in vivo data presented strongly support the conclusion that MOAP-1 is an important apoptotic modulator in ischemic injury. These results may suggest that a reduction of MOAP-1 function in the brain could be a potential therapeutic approach in the treatment of acute stroke.

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Bakuchiol Suppresses Inflammatory Responses Via the Downregulation of the p38 MAPK/ERK Signaling Pathway

International Journal of Molecular Sciences ◽

10.3390/ijms20143574 ◽

2019 ◽

Vol 20 (14) ◽

pp. 3574 ◽

Cited By ~ 4

Author(s):

Hye-Sun Lim ◽

Yu Jin Kim ◽

Bu-Yeo Kim ◽

Soo-Jin Jeong

Keyword(s):

Mrna Expression ◽

P38 Mapk ◽

Inflammatory Responses ◽

Mitogen Activated Protein Kinase ◽

Enzyme Linked Immunosorbent Assay ◽

Mice Model ◽

Tnf Α ◽

Cox 2

The purpose of the present study was to evaluate the effects of bakuchiol on the inflammatory response and to identify the molecular mechanism of the inflammatory effects in a lipopolysaccharide (LPS)-stimulated BV-2 mouse microglial cell line and mice model. The production of prostaglandin E2 (PGE2), tumor necrosis factor-α (TNF-α), and interleukin-6 (IL-6) was measured by enzyme-linked immunosorbent assay. The mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), TNF-α, and IL-6 was measured using reverse transcription–polymerase chain reaction analysis. Mitogen-activated protein kinase (MAPK) phosphorylation was determined by western blot analysis. In vitro experiments, bakuchiol significantly suppressed the production of PGE2 and IL-6 in LPS-stimulated BV-2 cells, without causing cytotoxicity. In parallel, bakuchiol significantly inhibited the LPS-stimulated expression of iNOS, COX-2, and IL-6 in BV-2 cells. However, bakuchiol had no effect on the LPS-stimulated production and mRNA expression of TNF-α or on LPS-stimulated c-Jun NH2-terminal kinase phosphorylation. In contrast, p38 MAPK and extracellular signal-regulated kinase (ERK) phosphorylation were inhibited by bakuchiol. In vivo experiments, Bakuchiol reduced microglial activation in the hippocampus and cortex tissue of LPS-injected mice. Bakuchiol significantly suppressed LPS-injected production of TNF-α and IL-6 in serum. These results indicate that the anti-neuroinflammatory effects of bakuchiol in activated microglia are mainly regulated by the inhibition of the p38 MAPK and ERK pathways. We suggest that bakuchiol may be beneficial for various neuroinflammatory diseases.

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CDDO-Me Attenuates Vasogenic Edema and Astroglial Death by Regulating NF-κB p65 Phosphorylations and Nrf2 Expression Following Status Epilepticus

International Journal of Molecular Sciences ◽

10.3390/ijms20194862 ◽

2019 ◽

Vol 20 (19) ◽

pp. 4862 ◽

Cited By ~ 5

Author(s):

Min-Ju Kim ◽

Hana Park ◽

Seo-Hyeon Choi ◽

Min-Jeong Kong ◽

Ji-Eun Kim ◽

...

Keyword(s):

Endothelial Cells ◽

Status Epilepticus ◽

Vasogenic Edema ◽

Acid Methyl Ester ◽

Nuclear Factor Κb ◽

Related Factor ◽

Nuclear Factor ◽

Edema Formation ◽

Tnf Α ◽

Nrf2 Expression

2-Cyano-3,12-dioxo-oleana-1,9(11)-dien-28-oic acid methyl ester (CDDO-Me) is a triterpenoid analogue of oleanolic acid that has anti-inflammatory, antioxidant, and neuroprotective activities. In the present study, we evaluate the effects of CDDO-Me on serum extravasation and astroglial death in the rat piriform cortex (PC) induced by status epilepticus (a prolonged seizure activity, SE) in order to propose an underlying pharmacological mechanism of CDDO-Me and its availability for treatment of vasogenic edema. CDDO-Me effectively mitigated serum extravasation and a massive astroglial loss in the PC following SE. CDDO-Me abrogated tumor necrosis factor-α (TNF-α) synthesis in activated microglia by inhibiting nuclear factor-κB (NF-κB) p65 serine 276 phosphorylation. CDDO-Me also abolished NF-κB threonine 435 phosphorylation in endothelial cells and TNF-α-mediated-phosphatidylinositol-3-kinase (PI3K)/AKT/endothelial nitric oxide synthase (eNOS) signaling cascades, which trigger vasogenic edema following SE. Furthermore, CDDO-Me increased astroglial viability via the up-regulation of nuclear factor-erythroid 2-related factor 2 (Nrf2) expression. Therefore, our findings suggest that CDDO-Me may ameliorate SE-induced vasogenic edema formation by regulating NF-κB p65 phosphorylations in microglia as well as endothelial cells and enhancing Nrf2 expression in astrocytes, respectively.

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DHEA Attenuates Microglial Activation via Induction of JMJD3 in Experimental Subarachnoid Haemorrhage

Journal of Neuroinflammation ◽

10.1186/s12974-019-1641-y ◽

2019 ◽

Vol 16 (1) ◽

Cited By ~ 7

Author(s):

Tao Tao ◽

Guang-Jie Liu ◽

Xuan Shi ◽

Yan Zhou ◽

Yue Lu ◽

...

Keyword(s):

Subarachnoid Haemorrhage ◽

Microglial Activation ◽

Neuronal Damage ◽

Neuroprotective Effect ◽

Early Brain Injury ◽

Protective Effects ◽

In Vivo Models ◽

The Brain

Abstract Background Microglia are resident immune cells in the central nervous system and central to the innate immune system. Excessive activation of microglia after subarachnoid haemorrhage (SAH) contributes greatly to early brain injury, which is responsible for poor outcomes. Dehydroepiandrosterone (DHEA), a steroid hormone enriched in the brain, has recently been found to regulate microglial activation. The purpose of this study was to address the role of DHEA in SAH. Methods We used in vivo models of endovascular perforation and in vitro models of haemoglobin exposure to illustrate the effects of DHEA on microglia in SAH. Results In experimental SAH mice, exogenous DHEA administration increased DHEA levels in the brain and modulated microglial activation. Ameliorated neuronal damage and improved neurological outcomes were also observed in the SAH mice pretreated with DHEA, suggesting neuronal protective effects of DHEA. In cultured microglia, DHEA elevated the mRNA and protein levels of Jumonji d3 (JMJD3, histone 3 demethylase) after haemoglobin exposure, downregulated the H3K27me3 level, and inhibited the transcription of proinflammatory genes. The devastating proinflammatory microglia-mediated effects on primary neurons were also attenuated by DHEA; however, specific inhibition of JMJD3 abolished the protective effects of DHEA. We next verified that DHEA-induced JMJD3 expression, at least in part, through the tropomyosin-related kinase A (TrkA)/Akt signalling pathway. Conclusions DHEA has a neuroprotective effect after SAH. Moreover, DHEA increases microglial JMJD3 expression to regulate proinflammatory/anti-inflammatory microglial activation after haemoglobin exposure, thereby suppressing inflammation.

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