Local Brain Tissue Research Articles

In vivo blue light illumination for optogenetic inhibition: effect on local temperature and excitability of the rat hippocampus

Objective. The blue light-activated inhibitory opsin, stGtACR2, is gaining prominence as a neuromodulatory tool due its ability to shunt-inhibit neurons and is being frequently used in in vivo experimentation. However, experiments involving stGtACR2 use longer durations of blue light pulses, which inadvertently heat up the local brain tissue and confound experimental results. Therefore, the heating effects of illumination parameters used for in vivo optogenetic inhibition must be evaluated. Approach. To assess blue light (473 nm)-induced heating of the brain, we used a computational model as well as direct temperature measurements using a fiber Bragg grating (FBG). The effects of different light power densities (LPDs) and pulse durations on evoked potentials (EP) recorded from dentate gyrus were assessed. For opsin-negative rats, LPDs between 127 and 636 mW mm−2 and pulse durations between 20 and 5120 ms were tested while for stGtACR2 expressing rats, LPD of 127 mW mm−2 and pulse durations between 20 and 640 ms were tested. Main results. Increasing LPDs and pulse durations logarithmically increased the peak temperature and significantly decreased the population spike (PS) amplitude and latencies of EPs. For a pulse duration of 5120 ms, the tissue temperature increased by 0.6 °C–3.4 °C. All tested LPDs decreased the PS amplitude in opsin-negative rats, but 127 mW mm−2 had comparatively minimal effects and a significant effect of increasing light pulse duration was seen from 320 ms and beyond. This corresponded with an average temperature increase of 0.2 °C–1.1 °C at the recorded site. Compared to opsin-negative rats, illumination in stGtACR2-expressing rats resulted in much greater inhibition of EPs. Significance. Our study demonstrates that light-induced heating of the brain can be accurately measured in vivo using FBG sensors. Such light-induced heating alone can affect neuronal excitability. Useful neuromodulation by the activation of stGtACR2 is still possible while minimizing thermal effects.

Smart arginine-equipped polycationic nanoparticles for p/CRISPR delivery into cells

An efficient and safe delivery system for the transfection of CRISPR plasmid (p/CRISPR) into target cells can open new avenues for the treatment of various diseases. Herein, we design a novel nonvehicle by integrating an arginine-disulfide linker with low-molecular-weight PEI (PEI1.8k) for the delivery of p/CRISPR. These PEI1.8k-Arg nanoparticles facilitate the plasmid release and improve both membrane permeability and nuclear localization, thereby exhibiting higher transfection efficiency compared to native PEI1.8k in the delivery of nanocomplexes composed of PEI1.8k-Arg and p/CRISPR into conventional cells (HEK 293T). This nanovehicle is also able to transfect p/CRISPR in a wide variety of cells, including hard-to-transfect primary cells (HUVECs), cancer cells (HeLa), and neuronal cells (PC-12) with nearly 5–10 times higher efficiency compared to the polymeric gold standard transfection agent. Furthermore, the PEI1.8k-Arg nanoparticles can edit the GFP gene in the HEK 293T-GFP reporter cell line by delivering all possible forms of CRISPR/Cas9 system (e.g. plasmid encoding Cas9 and sgRNA targeting GFP, and Cas9/sgRNA ribonucleoproteins (RNPs) as well as Cas9 expression plasmid and in vitro-prepared sgRNA) into HEK 293T-GFP cells. The successful delivery of p/CRISPR into local brain tissue is also another remarkable capability of these nanoparticles. In view of all the exceptional benefits of this safe nanocarrier, it is expected to break new ground in the field of gene editing, particularly for therapeutic purposes.

Activation and Role of Astrocytes in Ischemic Stroke.

Ischemic stroke refers to the disorder of blood supply of local brain tissue caused by various reasons. It has high morbidity and mortality worldwide. Astrocytes are the most abundant glial cells in the central nervous system (CNS). They are responsible for the homeostasis, nutrition, and protection of the CNS and play an essential role in many nervous system diseases’ physiological and pathological processes. After stroke injury, astrocytes are activated and play a protective role through the heterogeneous and gradual changes of their gene expression, morphology, proliferation, and function, that is, reactive astrocytes. However, the position of reactive astrocytes has always been a controversial topic. Many studies have shown that reactive astrocytes are a double-edged sword with both beneficial and harmful effects. It is worth noting that their different spatial and temporal expression determines astrocytes’ various functions. Here, we comprehensively review the different roles and mechanisms of astrocytes after ischemic stroke. In addition, the intracellular mechanism of astrocyte activation has also been involved. More importantly, due to the complex cascade reaction and action mechanism after ischemic stroke, the role of astrocytes is still difficult to define. Still, there is no doubt that astrocytes are one of the critical factors mediating the deterioration or improvement of ischemic stroke.

Effect Of Butylphthalide Combined with Ozagrel Sodium on Cerebral Perfusion and Oxidative Stress Indexes in Patients with Transient Ischemic Attack

Background The pathogenesis of transient ischemic attack is not clear. Microthrombosis theory is a theory with high clinical recognition. Microthrombosis of carotid artery and vertebral basilar artery wall occurs shedding and vasospasm, resulting in transient cerebral insufficiency. Microembolic decomposition or distal movement, cerebrovascular dilatation, local collateral circulation after the establishment of symptoms relieved or disappeared. Most patients can be relieved in a short time, but recurrent attacks can gradually damage the structure and function of brain tissue, and increase the risk of acute cerebral infarction. The clinical treatment of this disease is mainly based on the comprehensive control of risk factors, anti thrombosis, and anti-platelet aggregation. Objective To observe the effect of butylphthalide combined with ozagrel sodium on cerebral perfusion and oxidative stress indexes in patients with transient ischemic attack. Methods A total of 116 patients diagnosed as transient ischemic attack in our hospital (February 2018 - February 2020) were selected and divided into two groups according to the treatment methods. 58 cases in the control group were treated with ozagrel sodium, 58 cases in the observation group were treated with butylphthalide combined with ozagrel sodium. The CT perfusion imaging parameters, oxidative stress indexes, plaque area, and the levels of platelet activating factor ( PAF ), α-granule membrane protein-140 ( GMP-140 ), fibrinogen ( FIB ), platelet aggregation rate (PAgT), neuron-specific enolase (NSE), oxygend-inducible factor-1α (HIF-1α), and matrix metalloproteinases 9 (MMP-9) in the two groups were recorded, and the total effective rate and adverse reaction rate were counted. Results The total effective rate of the observation group was higher than that of the control group, and the difference was statistically significant (χ2=4.640, P = 0.031). Compared with before treatment, the average time (MTT) required for the two groups of contrast agents to pass through the local brain tissue and the time (TTP) required to start the injection of contrast agents to reach the peak concentration decreased compared with before treatment. After treatment, the MTT and TTP of the observation group were shorter than those of the control group (P < 0.05). Compared with before treatment, superoxide dismutase ( SOD ) in the two groups was higher than that in the control group, PAF, GMP-140, FIB, PAgT, NSE, HIF-la, MMP-9, malondialdehyde (MDA) and plaque area decreased. After treatment, the levels of related factors in the observation group were better than those in the control group, and the plaque area was less than that in the control group (P < 0.05). There was no significant difference in the adverse reaction rate between the observation group and the control group (χ2 = 0.438, P=0.508). Conclusion Butylphthalide combined with ozagrel sodium in the treatment of transient ischemic attack can improve cerebral perfusion, reduce oxidative stress injury, reduce plaque and improve curative effect.

25-Hydroxycholesterol protecting from cerebral ischemia-reperfusion injury through the inhibition of STING activity.

Middle cerebral artery occlusion (MCAO) injury refers to impaired blood supply to the brain that is caused by a cerebrovascular disease, resulting in local brain tissue ischemia, hypoxic necrosis, and rapid neurological impairment. Nevertheless, the mechanisms involved are unclear, and pharmacological interventions are lacking. 25-Hydroxycholesterol (25-HC) was reported to be involved in cholesterol and lipid metabolism as an oxysterol molecule. This study aimed to determine whether 25-HC exerts a cerebral protective effect on MCAO injury and investigate its potential mechanism. 25-HC was administered prior to reperfusion in a mouse model of MCAO injury. 25-HC evidently decreased infarct size induced by MCAO and enhanced brain function. It reduced stimulator of interferon gene (STING) activity and regulated mTOR to inhibit autophagy and induce cerebral ischemia tolerance. Thus, 25-HC improved MCAO injury through the STING channel. As indicated in this preliminary study, 25-HC improved MCAO injury by inhibiting STING activity and autophagy as well as by reducing brain nerve cell apoptosis. Thus, it is a potential treatment drug for brain injury.

Does Src Kinase Mediated Vasoconstriction Impair Penumbral Reperfusion?

Despite successful recanalization, a significant number of patients with ischemic stroke experience impaired local brain tissue reperfusion with adverse clinical outcome. The cause and mechanism of this multifactorial complication are yet to be understood. At the current moment, major attention is given to dysfunction in blood-brain barrier and capillary blood flow but contribution of exaggerated constriction of cerebral arterioles has also been suggested. In the brain, arterioles significantly contribute to vascular resistance and thus control of perfusion. Accordingly, pathological changes in arteriolar wall function can, therefore, limit sufficient reperfusion in ischemic stroke, but this has not yet received sufficient attention. Although an increased vascular tone after reperfusion has been demonstrated in several studies, the mechanism behind it remains to be characterized. Importantly, the majority of conventional mechanisms controlling vascular contraction failed to explain elevated cerebrovascular tone after reperfusion. We propose here that the Na,K-ATPase-dependent Src kinase activation are the key mechanisms responsible for elevation of cerebrovascular tone after reperfusion. The Na,K-ATPase, which is essential to control intracellular ion homeostasis, also executes numerous signaling functions. Under hypoxic conditions, the Na,K-ATPase is endocytosed from the membrane of vascular smooth muscle cells. This initiates the Src kinase signaling pathway that sensitizes the contractile machinery to intracellular Ca2+ resulting in hypercontractility of vascular smooth muscle cells and, thus, elevated cerebrovascular tone that can contribute to impaired reperfusion after stroke. This mechanism integrates with cerebral edema that was suggested to underlie impaired reperfusion and is further supported by several studies, which are discussed in this article. However, final demonstration of the molecular mechanism behind Src kinase-associated arteriolar hypercontractility in stroke remains to be done.

Elucidation of Regional Mechanical Properties of Brain Tissues Based on Cell Density

Research on the mechanical properties of brain tissue has received extensive attention. However, most of the current studies have been conducted at the phenomenological level. In this study, the indentation method was used to explore the difference in local mechanical properties among different regions of the porcine cerebral cortex. Further, hematoxylin-eosin and immunofluorescence staining methods were used to determine the correlation between the cellular density at different test points and mechanical properties of the porcine cerebral cortex. The frontal lobe exhibited the strongest viscosity. The temporal lobe displayed the lowest sensitivity to changes in the indentation speed, and the occipital lobe exhibited the highest shear modulus. Additionally, the shear modulus of different areas of the cerebral cortex was negatively correlated with the total number of local cells per unit area and positively correlated with the number of neuronal cell bodies per unit area. Exploration of the mechanical properties of the local brain tissue can provide basic data for the establishment of a finite element model of the brain and mechanical referential information for the implantation position of brain chips.

Morin Provides Neuroprotection in a Model of Cerebral Infarction Via Nrf-2 Signaling Pathway

Cerebral infarction, also known as ischemic stroke, is a disorder of blood supply in the local brain tissue and the second leading cause of death worldwide. It is important to develop effective drugs to treat cerebral infarction. Morin (3,5,7,2′, 4′-pentahydroxyflavone) is a bioactive flavonol that has multiple medicinal properties including antioxidant, anti-inflammatory, anti-invasive, antitumor, and antiangiogenic properties. However, its potential effect on ischemic stroke as a potent neuroprotective and cardioprotective agent remains unknown. In this study, we constructed a rat model of cerebral infarction and shown morin to be neuroprotective in this model. Additionally, morin inhibited nerve cell apoptosis and cerebral infarction induced oxidative stress in brain tissue. Our data further confirmed that morin provides neuroprotection in cerebral infarction via upregulation of the downstream proteins of Nrf2 pathway. We therefore suggest morin as a promising therapeutic drug for the treatment of cerebral infarction.

Lin28a attenuates cerebral ischemia/reperfusion injury through regulating Sirt3-induced autophagy

Cerebral ischemia-reperfusion injury causes damage to local brain tissue and its function, but its specific pathogenesis is still unclear. Autophagy is an important catabolic pathway in eukaryotic cells, which is mainly used to remove damaged intracellular organelles, misfolded long-acting macromolecules and participate in cerebral ischemia-reperfusion injury. Lin28 is a highly conserved RNA-binding protein that plays a role in regulating gene translation, which is important for the growth and maintenance of pluripotent cells. Lin28a has been reported to have a clear protective effect on post-ischemic reperfusion injury of the heart. However, whether Lin28a has an effect on nerve injury after cerebral ischemia-reperfusion needs further study. In this study, we found that the expression of Lin28a was decreased in cerebral ischemia-reperfusion mice model. Upregulation of Lin28a could alleviate the nerve injury caused by ischemia-reperfusion, and promote autophagy of nerve cells. Upregulation of Lin28a reduced nerve cell apoptosis and relieved nerve cell injure induced by oxygen-glucose deprivation/reoxygenation. Lin28a increased the LC3-II levels in nerve cells, suggesting the promotion of autophagy. Mechanism studies indicated that Lin28a promoted autophagy mainly through regulating Sirt3 expression and activating AMPK-mTOR pathway. In conclusion, our study revealed the important role of Lin28a in cerebral ischemia-reperfusion and suggested that Lin28a was a protective factor for cerebral ischemia-induced injury.

MiR-21-3p alleviates neuronal apoptosis during cerebral ischemiareperfusion injury by targeting SMAD2

Cerebral ischemia is due to the formation of blood clots or embolisms in the brain arteries, which leads to local brain tissue necrosis and neural cell apoptosis. Recent studies have shown that microRNA (miRNA) plays an important regulatory role in the pathological process of ischemic injury. The aim of this study is to investigate the role and the mechanism of miR-21-3p and drosophila mothers against decapentaplegic 2 (SMAD2) in cerebral ischemic reperfusion injured (CIRI) neural cells. The CIRI model was established by oxygen-glucose deprivation and recovery process for N2a cells. The cell viability and the apoptotic was evaluated by MTT assay and the Flow Cytometer, respectively. The expression of miR-21-3p and SMAD2 mRNA was detected by real-time fluorescence quantitative PCR (qRT-PCR), and the expression of SMAD2 and apoptotic-related proteins were detected by Western Blotting. Our results showed that miR-21-3p is down-regulated, and SMAD2 is up-regulated in CIRI. Overexpression of miR- 21-3p inhibits the apoptosis of neural cells in CIRI. miR-21-3p targets SMAD2 and inhibits SMAD2 expression. Overexpression of SMAD2 eliminates the protective effect of over-expression of miR-21-3p on neural cells in CIRI. Token together, this study provides a theoretical basis for the mechanism of ischemic reperfusion injury in neural cells and a new molecular target for ischemic stroke therapy.

A longitudinal study of brain volume changes in rhesus macaque model infected with SIV.

Given the current lack of understanding of brain volume changes caused by HIV infection, this study aimed to longitudinally assess the changes in regional brain tissue volume following HIV infection and to explore its relationship with peripheral blood absolute CD4+ lymphocyte count (CD4+), the percentage of monocytes in plasma(MON%) and cerebrospinal fluid viral load (CFVL).Four adult male rhesus monkeys were examined in healthy status and following infection with simian immunodeficiency virus using high-resolution 3D T1-weighted sagittal whole brain magnetic resonance imaging. DPABI and SPM were used to process and record changes in brain tissue volume. Correlation analyses were then used to explore the above relationships. Compared with brain tissue volume during the healthy stage, there was no change at 12 and 24weeks postinoculation (12wpi, 24wpi). At 36wpi, 48wpi, and 60wpi, basal ganglia, left inferior temporal gyrus, left occipital gyrus, and left superior frontal gyrus exhibited varying degrees of atrophy. There was no association found between CD4+, MON%, CFVL, and brain volume loss in any brain region. Our research demonstrated that in the early stage of HIV infection, local brain tissue atrophy can be demonstrated by MRI technique; furthermore, MRI can identify the earliest site of atrophy as well as the most severely affected site. Although there was no significant correlation between brain tissue volume loss and CD4+, MON%, and CFVL, our findings provided some evidence in the application of volumetric MR imaging in the early diagnosis and treatment follow-up of patients with HIV infection.

Injectable SN-38-embedded Polymeric Microparticles Promote Antitumor Efficacy against Malignant Glioma in an Animal Model

Malignant glioma (MG) is extremely aggressive and highly resistant to chemotherapeutic agents. Using electrospraying, the potent chemotherapeutic agent 7-ethyl-10-hydroxycamptothecia (SN-38) was embedded into 50:50 biodegradable poly[(d,l)-lactide-co-glycolide] (PLGA) microparticles (SMPs). The SMPs were stereotactically injected into the brain parenchyma of healthy rats and intratumorally injected into F98 glioma-bearing rats for estimating the pharmacodynamics and therapeutic efficacy. SN-38 was rapidly released after injection and its local (brain tissue) concentration remained much higher than that in the blood for more than 8 weeks. Glioma-bearing rats were divided into three groups—group A (n = 13; stereotactically injected pure PLGA microparticles), group B (n = 12; stereotactically injected Gliadel wafer and oral temozolomide), and group C (n = 13; stereotactic and intratumoral introduction of SMPs). The SMPs exhibited significant therapeutic efficacy, with prolonged survival, retarded tumor growth, and attenuated malignancy. The experimental results demonstrated that SMPs provide an effective and potential strategy for the treatment of MG.

Standardizing the cerebrovascular response to hypercapnia - increasing the flow of data!

Standardizing the cerebrovascular response to hypercapnia - increasing the flow of data!

Prostaglandin EP3 receptor‐expressing neurons in the preoptic area are activated by ambient heat exposure

The preoptic area (POA) receives cutaneous warm and cold inputs ascending through the lateral parabrachial nucleus, and local neural circuits in the POA function as a center for body temperature regulation. The cutaneous warm inputs to the POA can activate inhibitory neurons therein, which then inhibit the sympathoexcitatory efferent neural pathways that otherwise drive cold‐defensive thermogenesis and cutaneous vasoconstriction. The POA also contains warm‐sensitive neurons that have intrinsic warm sensitivity to monitor body core (local brain tissue) temperature and thereby determine the basal tone of the thermoregulatory efferent signaling, although the histochemical or molecular identity of warm‐sensitive neurons remains unknown. The prostaglandin EP3 receptor, a Gi‐coupled inhibitory receptor of prostaglandin E2, a pyrogenic mediator, is expressed in POA neurons, and an action of prostaglandin E2 on these neurons triggers fever likely by disinhibiting sympathoexcitatory neurons in the dorsomedial hypothalamus and the rostral medullary raphe region. To determine whether EP3 receptor‐expressing POA neurons contribute to thermal homeostasis in warm and cold conditions, in this study, we exposed rats to a heated (36°C), control (24°C) or cold (4°C) environment for two hours and examined activation of EP3 receptor‐expressing POA neurons by double‐immunostaining for EP3 receptors and c‐Fos, a marker for neuronal activation. Heat‐exposed rats exhibited a significant increase in c‐Fos‐positive cells in EP3 receptor‐expressing POA neurons, compared with rats exposed to the control environment. However, cold exposure had no significant effect on the number of c‐Fos‐positive cells in EP3 receptor‐expressing POA neurons, compared with control exposure. These results suggest that EP3 receptor‐expressing POA neurons are activated in hot environments due to its intrinsic warm sensitivity and/or by cutaneous warm inputs and function for heat defense, as well as fever development after infection.Support or Funding InformationJSPS KAKENHI 17K08568, 23790271 & 26860159 (YN), 16H05128, 15H05932 & 26118508 (KN); AMED JP18gm5010002 (KN); Hori Sciences and Arts Foundation (YN)This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Detection of neural light-scattering activity in vivo: optical transmittance studies in the rat brain

Optical studies of ex vivo brain slices where blood is absent show that neural activity is accompanied by significant intrinsic optical signals (IOS) related to activity-dependent scattering changes in neural tissue. However, the neural scattering signals have been largely ignored in vivo in widely-used IOS methods where absorption contrast from hemoglobin was employed. Changes in scattering were observed on a time scale of seconds in previous brain slice IOS studies, similar to the time scale for the hemodynamic response. Therefore, potential crosstalk between the scattering and absorption changes may not be ignored if they have comparable contributions to IOS. In vivo, the IOS changes linked to neural scattering have been elusive. To isolate neural scattering signals in vivo, we employed 2 implantable optodes for small-separation (2 mm) transmission measurements of local brain tissue in anesthetized rats. This unique geometry enables us to separate neuronal activity-related changes in neural tissue scattering from changes in blood absorption based upon the direction of the signal change. The changes in IOS scattering and absorption in response to up-states of spontaneous neuronal activity in cortical or subcortical structures have strong correlation to local field potentials, but significantly different response latencies. We conclude that activity-dependent neural tissue scattering in vivo may be an additional source of contrast for functional brain studies that provides complementary information to other optical or MR-based systems that are sensitive to hemodynamic contrast.

Micro-imaging of Brain Cancer Radiation Therapy Using Phase-contrast Computed Tomography

Experimental neuroimaging provides a wide range of methods for the visualization of brain anatomic morphology down to subcellular detail. Still, each technique-specific detection mechanism presents compromises among the achievable field-of-view size, spatial resolution, and nervous tissue sensitivity, leading to partial sample coverage, unresolved morphologic structures, or sparse labeling of neuronal populations and often also to obligatory sample dissection or other sample invasive manipulations. X-ray phase-contrast imaging computed tomography (PCI-CT) is an experimental imaging method that simultaneously provides micrometric spatial resolution, high soft-tissue sensitivity, and exvivo full organ rodent brain coverage without any need for sample dissection, staining or labeling, or contrast agent injection. In the present study, we explored the benefits and limitations of PCI-CT use for invitro imaging of normal and cancerous brain neuromorphology after invivo treatment with synchrotron-generated x-ray microbeam radiation therapy (MRT), a spatially fractionated experimental high-dose radiosurgery. The goals were visualization of the MRT effects on nervous tissue and a qualitative comparison of the results to the histologic and high-field magnetic resonance imaging findings. MRT was administered invivo to the brain of both healthy and cancer-bearing rats. At 45days after treatment, the brain was dissected out and imaged exvivo using propagation-based PCI-CT. PCI-CT visualizes the brain anatomy and microvasculature in 3 dimensions and distinguishes cancerous tissue morphology, necrosis, and intratumor accumulation of iron and calcium deposits. Moreover, PCI-CT detects the effects of MRT throughout the treatment target areas (eg, the formation of micrometer-thick radiation-induced tissue ablation). The observed neurostructures were confirmed by histologic and immunohistochemistry examination and related to the micro-magnetic resonance imaging data. PCI-CT enabled a unique 3D neuroimaging approach for exvivo studies on small animal models in that it concurrently delivers high-resolution insight of local brain tissue morphology in both normal and cancerous micro-milieu, localizes radiosurgical damage, and highlights the deep microvasculature. This method could assist experimental small animal neurology studies in the postmortem evaluation of neuropathology or treatment effects.

The soluble guanylate cyclase stimulator IWP‐550 inhibits neuroinflammation in vitro and in vivo

ObjectiveIWP‐550 is a brain‐penetrant soluble guanylate cyclase (sGC) stimulator. The objective of this work was to evaluate the effects of IWP‐550 on neuroinflammation in vitro in rat primary neurons, mouse microglial cells, rat brain 3D microtissues (MT, InSphero™), and in an in vivo quinolinic acid (QA)‐induced neuroinflammation rat model.MethodsMouse microglial SIM‐A9 cells, rat primary neurons and rat brain MT were stimulated with IWP‐550 for 30 min at 37°C. cGMP levels were measured by LC/MS. Phosphorylation of vasodilator‐stimulated phosphoprotein (VASP) and CREB was assayed using CisBio HTRF kits. For cytokine studies, cells or brain MT were treated with LPS and IWP‐550 for 24 h at 37°C. IL‐6 and TNFα levels in SIM‐A9 cells were determined by ELISA. Cytokines from isolated rat primary neurons and brain MT were measured by MSD multiplex assay. Neuroinflammation was induced in vivo by injecting QA in the rat striatum followed by treatment with IWP‐550 (10 mg/kg, p.o. QD) for 7 days. In the striatum, expression of ionized calcium‐binding adapter molecule 1 (Iba1), a marker of microglial activation, and glial fibrillary acidic protein (GFAP), a marker of astrogliosis, was quantified by IHC staining. Gene expression of TNFα, CD40, and MIP1α was determined by QuantiGene MultiPlex Assay (Affymetrix).ResultsIWP‐550 dose‐dependently stimulated cGMP formation (EC50 = 16 nM) and phosphorylation of CREB in isolated rat primary neurons. IWP‐550 also stimulated cGMP formation and phosphorylation of VASP in SIM‐A9 cells in synergy with the nitric oxide donor, DETA‐NONOate (DETA). In rat primary neurons, IWP‐550 decreased secreted proinflammatory cytokines, including IL‐1β, TNFα and MCP‐1 that were elevated by LPS treatment (1 μg/ml). In SIM‐A9 cells, IWP‐550 dose‐dependently decreased LPS‐mediated IL‐6 and TNFα elevation. In brain MT containing a mix of neurons, astrocytes, microglial cells and oligodendrocytes, IWP‐550 stimulated cGMP formation and phosphorylation of CREB. Moreover, IWP‐550 (1 and 10 μM) in the presence of DETA (10 μM) reduced LPS‐induced elevation of IL‐6, IFNγ, TNFα, IL‐1β, IL‐13 and CXCL1. In rat, QA administered unilaterally in the striatum caused local brain tissue injury and led to the activation of microglia and astrocytes, as demonstrated by increases in IHC staining for Iba1 and GFAP compared to the control side of striatum. Gene expression of pro‐inflammatory cytokines TNFα, CD40 and MIP1α were also increased following QA injection. Treatment with IWP‐550 (10 mg/kg) for 7 days significantly reduced Iba1 and GFAP staining, as well as gene expression of TNFα, CD40 and MIP1α, indicating a reduction of QA‐induced astrogliosis and inflammation in vivo.ConclusionIWP‐550 suppressed neuroinflammation in vitro in primary neurons, microglial cells, and brain microtissues, as well as in vivo in QA‐treated rats. These data suggest that sGC stimulation may provide potential neuroprotective effect by reducing neuroinflammation, a hallmark of neurodegenerative diseases.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Does the Choice of Treatment of Diabetes Mellitus Change Natural Course of Alzheimer Disease?

Alzheimer disease (AD) is common worldwide and almost every case has comorbidities. One of the most common comorbidities of AD is Diabetes mellitus (DM), with or without metabolic syndrome. Both diseases effect nerve tissue and successful treatment would improve the status of the patient. In patients with Alzheimer disease treatment of DM, the treatment could be harmful to the AD, because of that high insulin intake. This may lead to progression of AD. Insulin is considered the best treatment for DM, but insulin therapy could increase comorbidity with AD. No specific therapy for AD is known up to date, so because of that DM is one of the most important risk for AD, concomitant therapy for DM should be planned very carefully. All options of DM therapy should be considered, and different mechanisms of anti-diabetic drugs are preferable. Treatment of AD is more complex metabolic syndrome is present. Any inflammation causes local tissue damage, including brain tissue during AD. Release of interleukins, primarily TNF-α, IL-6, IL-1β in the presence of adipokine leptin, maintains chronic inflammatory status in local brain tissue. Thus, low doses of immunosuppressant therapy should be considered for treatment of AD in future. To delay apoptosis of nerve tissue cells, brain and nerve tissue defend against free oxygen radicals and improve metabolic status.

Neuropathologic findings in intractable epilepsy: a clinicopathologic analysis of 822 cases

Objective: To investigate the clinicopathologic characteristics of intractable epilepsy. Methods: Based on the classification criteria proposed by the International League Against Epilepsy (ILAE), a retrospective analysis of the pathological characteristics was done in 822 patients who underwent epilepsy surgery in Sanbo Brain Hospital, Capital Medical University, from June 2008 to December 2012. Results: The mean age of epilepsy onset was 9.9 years, mean duration of epilepsy was 11.9 years. Complex partial seizures were the main presenting features. Histopathological study showed 33 cases (4.01%) with mild forms of cortical malformations, 690 cases (83.94%) with focal cortical dysplasia (FCD) and 99 cases with others (including 39 pure hippocampal sclerosis, 20 cystosclerosis, 19 Sturge-Weber syndrome, 8 tuberous sclerosis complex, 6 without significant pathological changes, 5 gyral malformations and 2 hamartoma). Among the 690 FCD cases, 106 were FCD typeⅠ, 91 were FCD typeⅡ and 493 were FCDⅢ(Ⅲa: 160, Ⅲb: 106, Ⅲc: 26 and Ⅲd: 201). Conclusions: FCDⅢd is the most common histopathological subtype causing intractable epilepsy, mainly due to focal hypoxia/ischemia in the perinatal period, which results in scarring of local brain tissue; this is followed by other isolated forms of FCD (FCDⅠand FCDⅡ), and then FCD Ⅲa and FCD Ⅲb. The reason to distinguish isolated forms of FCD (types Ⅰ and Ⅱ) from FCD Ⅲ and to subclassify FCD Ⅲ is to allow better definition of cortical dyslamination. Therefore, the pathogenic factors of intractable epilepsy can be grouped in greater details, and facilitate the diagnosis and potential curative treatment of intractable epilepsy.

Investigation of brain tissue infiltration by medulloblastoma cells in an ex vivo model

Medulloblastoma (MB) is a paediatric cancer of the cerebellum that can develop cerebellar and leptomeningeal metastases. Local brain tissue infiltration, the underlying cause of metastasis and relapse, remains unexplored. We developed a novel approach to investigate tissue infiltration of MB using organotypic cerebellum slice culture (OCSC). We show that cellular and structural components of cerebellar tissue in OCSCs are maintained for up to 30 days ex vivo, and that OCSCs foster tumour growth and cell proliferation. Using cell-based models of sonic hedgehog (SHH) and group 3 (G3) MB, we quantified tumour growth and infiltration and determined the morphological characteristics of the infiltrating cells. We observed basal levels of dissemination occurring in both subgroups with cells migrating either individually or collectively as clusters. Collective cerebellar tissue infiltration of SHH MB cells was further enhanced by EGF but not HGF, demonstrating differential tumour cell responses to microenvironmental cues. We found G3 cells to be hyper proliferative and observed aggressive tumour expansion even in the absence of exogenous growth factors. Our study thus provides unprecedented insights into brain tissue infiltration of SHH and G3 MB cells and reveals the cellular basis of the tumour progressing functions of EGF in SHH MB.