What Elements of the Inflammatory System Are Necessary for Epileptogenesis<i>In Vitro</i>?

Park, Kyung‐Il; Dzhala, Volodymyr; Saponjian, Yero; Staley, Kevin J.

doi:10.1523/eneuro.0027-14.2015

Cited by 12 publications

(13 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It was surprising that there were no differences in gene and protein expression of CD39 −/− versus CD39 +/+ microglia in PBS‐treated (relatively naive) mice despite an altered extracellular ATP/adenosine ratio in the microenvironment. This is consistent with the finding that microglia have no effect on epileptogenesis in hippocampal cultures . However, our results are inconsistent with reports showing that ATP and adenosine affect microglia activation and migration .…”

Section: Discussionsupporting

confidence: 70%

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures

et al. 2017

View full text Add to dashboard Cite

Seizures are due to excessive, synchronous neuronal firing in the brain and are characteristic of epilepsy, the fourth most prevalent neurological disease. We report handling-induced and spontaneous seizures in mice deficient for CD39, a cell-surface ATPase highly expressed on microglial cells. CD39 mice with handling-induced seizures had normal input-output curves and paired-pulse ratio measured from hippocampal slices and lacked microgliosis, astrogliosis or overt cell loss in the hippocampus and cortex. As expected, however, the cerebrospinal fluid of CD39 mice contained increased levels of ATP and decreased levels of adenosine. To determine if immune activation was involved in seizure progression, we challenged mice with lipopolysaccharide (LPS) and measured the effect on microglia activation and seizure severity. Systemic LPS challenge resulted in increased cortical staining of Iba1/CD68 and gene array data from purified microglia predicted increased expression of interleukin-8, triggering receptor expressed on myeloid cells 1, p38, pattern recognition receptors, death receptor, nuclear factor-κB , complement, acute phase, and interleukin-6 signalling pathways in CD39 versus CD39 mice. However, LPS treatment did not affect handling-induced seizures. In addition, microglia-specific CD39 deletion in adult mice was not sufficient to cause seizures, suggesting instead that altered expression of CD39 during development or on non-microglial cells such as vascular endothelial cells may promote the seizure phenotype. In summary, we show a correlation between altered extracellular ATP/adenosine ratio and a previously unreported seizure phenotype in CD39 mice. This work provides groundwork for further elucidation of the underlying mechanisms of epilepsy.

show abstract

Section: Discussionsupporting

confidence: 70%

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Recently, it was illustrated that anti‐inflammatory approaches can be antiepileptogenic in a study where epileptiform activity in OHSCs was reduced by applying anti–TNF‐α polyclonal antibody to the slices . However, another recent study reported no anti‐epilept(ogen)ic effects of microglia depletion in OHCSs, suggesting that not all elements of the inflammatory response are essential for epileptogenesis in vitro . In our experiments, increased expression of inflammatory markers IL‐1β, IL‐6, and TGF‐β was found in vehicle‐treated slices at 21 DIV, and although the data did not reach significance at P < 0.05, a trend toward lower expression suggested a reduction by both rapamycin and curcumin.…”

Section: Discussioncontrasting

confidence: 43%

Curcumin reduces development of seizurelike events in the hippocampal‐entorhinal cortex slice culture model for epileptogenesis

et al. 2019

View full text Add to dashboard Cite

Summary Objective Inhibition of the mammalian target of rapamycin (mTOR) pathway could be antiepileptogenic in temporal lobe epilepsy (TLE), possibly via anti‐inflammatory actions. We studied effects of the mTOR inhibitor rapamycin and the anti‐inflammatory compound curcumin—also reported to inhibit the mTOR pathway—on epileptogenesis and inflammation in an in vitro organotypic hippocampal‐entorhinal cortex slice culture model. Methods Brain slices containing hippocampus and entorhinal cortex were obtained from 6‐day‐old rat pups and maintained in culture for up to 3 weeks. Rapamycin or curcumin was added to the culture medium from day 2 in vitro onward. Electrophysiological recordings revealed epileptiformlike activity that developed over 3 weeks. Results In week 3, spontaneous seizurelike events (SLEs) could be detected using whole cell recordings from CA1 principal neurons. The percentage of recorded CA1 neurons displaying SLEs was lower in curcumin‐treated slice cultures compared to vehicle‐treated slices (25.8% vs 72.5%), whereas rapamycin did not reduce SLE occurrence significantly (52%). Western blot for phosphorylated‐S6 (pS6) and phosphorylated S6K confirmed that rapamycin inhibited the mTOR pathway, whereas curcumin only lowered pS6 expression at one phosphorylation site. Real‐time quantitative polymerase chain reaction results indicated a trend toward lower expression of inflammatory markers IL‐1β and IL‐6 and transforming growth factor β after 3 weeks of treatment with rapamycin and curcumin compared to vehicle. Significance Our results show that curcumin suppresses SLEs in the combined hippocampal‐entorhinal cortex slice culture model and suggest that its antiepileptogenic effects should be further investigated in experimental models of TLE.

show abstract

“…We confirmed that KA‐induced neuronal loss in the hippocampus, particularly in the CA3 pyramidal cell layer (Figure A, ). Because the remarkable neuronal loss in CA3 accurately reproduces the pathological condition of mTLE ,. we mainly focused on changes in CA3.…”

Section: Resultsmentioning

confidence: 99%

“…To directly assess the role of microglia in KA‐induced neuronal death, we pharmacologically removed microglia from slice cultures before KA treatment at 7 DIV for 24 hours and histological evaluation of neuronal death was performed by immunostaining (Figure A, ). First, we used clodronate, which inhibits the ATP transporter and has been shown to specifically remove microglia without affecting other cells . Liposomal clodronate (0.5 mg/mL) was administered twice to slice cultures both at 0 and 3 DIV for 24 hours each.…”

Section: Resultsmentioning

confidence: 99%

“…Two reagents were used to deplete microglia from slice cultures. First, we used the liposomal clodronate Clophosome‐A (F70101C‐A; FormuMax, Sunnyvale, CA, USA), which is known to effectively deplete macrophages in the mouse spleen after a single intravenous or intraperitoneal administration . At 0 DIV and 3 DIV, Clophosome‐A (0.05 mg/mL) was added to the culture medium for 24 hours.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Microglia attenuate the kainic acid‐induced death of hippocampal neurons in slice cultures

Araki

Ikegaya

Koyama

2019

Neuropsychopharm Rep

View full text Add to dashboard Cite

Background Status epilepticus‐induced hippocampal neuronal death, astrogliosis, and the activation of microglia are common pathological changes in mesial temporal lobe epilepsy (mTLE) with resistance to antiepileptic drugs. Neuronal death in mTLE gradually progresses and is involved in the aggravation of epilepsy and the impairment of hippocampus‐dependent memory. Thus, clarifying the cellular mechanisms by which neurons are protected in mTLE will significantly contribute to the treatment of epilepsy. Here, mainly using hippocampal slice cultures with or without the pharmacological depletion of microglia, we directly examined whether microglia, the resident immune cells of the brain that can act either neurotoxically or in a neuroprotective manner, accelerate or attenuate kainic acid (KA)‐induced neuronal death in vitro. Methods Hippocampal slice cultures were treated with KA to induce neuronal death in vitro. Clodronate‐containing liposomes or PLX3397 was used to deplete microglia in hippocampal slice cultures, and the effect on KA‐induced neuronal death was immunohistochemically assessed. Results The loss of microglia significantly promoted a decrease in neuronal density in KA‐treated hippocampal slice cultures. Conclusion Our results suggest that microglia are neuroprotective against KA‐induced neuronal death in slice cultures.

show abstract

What Elements of the Inflammatory System Are Necessary for EpileptogenesisIn Vitro?

Cited by 12 publications

References 59 publications

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures

Curcumin reduces development of seizurelike events in the hippocampal‐entorhinal cortex slice culture model for epileptogenesis

Microglia attenuate the kainic acid‐induced death of hippocampal neurons in slice cultures

Contact Info

Product

Resources

About

What Elements of the Inflammatory System Are Necessary for EpileptogenesisIn Vitro?

Cited by 12 publications

References 59 publications

Disruption of theATP/adenosine balance inCD39−/−mice is associated with handling‐induced seizures

Disruption of theATP/adenosine balance inCD39−/−mice is associated with handling‐induced seizures

Curcumin reduces development of seizurelike events in the hippocampal‐entorhinal cortex slice culture model for epileptogenesis

Microglia attenuate the kainic acid‐induced death of hippocampal neurons in slice cultures

Contact Info

Product

Resources

About

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures

Disruption of theATP/adenosine balance inCD39^−/−mice is associated with handling‐induced seizures