The TSPO-specific Ligand PK11195 Protects Against LPS-Induced Cognitive Dysfunction by Inhibiting Cellular Autophagy

Perioperative neurocognitive disorders (PND) is a common postoperative neurological complication. Neuroinflammation is a major cause that leads to PND. Autophagy, an intracellular process of lysosomal degradation, plays an important role in the development and maintenance of nervous system. PK11195 is a classic translocator protein (TSPO) ligand, which can improve the cognitive function of rats. In this study, we evaluate the protective effect of PK11195 on the learning and memory of rats. A rat model of lipopolysaccharide (LPS)-induced cognitive dysfunction was established by intraperitoneal injection of LPS. Morris Water Maze (MWM), Western blot, qRT-PCR, confocal microscopy and transmission electron microscopy (TEM) were used to study the role of TSPO-specific ligand PK11195 in LPS-activated mitochondrial autophagy in rat hippocampus. We found that PK11195 ameliorated LPS-induced learning and memory impairment, as indicated by decreased escape latencies, swimming distances and increased target quadrant platform crossing times and swimming times during MWM tests. TSPO, ATG7, ATG5, LC3B and p62 protein and mRNA expression increased in the hippocampus of PND model rats. The hippocampal microglia of PND model rats also have severe mitochondrial damage, and a large number of autophagosomes and phagocytic vesicles can be seen. PK11195 pretreatment significantly decreased the expression of TSPO, ATG7, ATG5, LC3B and p62 protein and mRNA, as well as mitochondrial damage. These findings suggested that PK11195 may alleviate the damage of LPS-induced cognitive dysfunction of rats by inhibiting microglia activation and autophagy.

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Dysfunction of EAAT3 Enhances LPS-induced Postoperative Cognitive Dysfunction

10.21203/rs.3.rs-169684/v1 ◽

2021 ◽

Author(s):

Xiaoyan Wang ◽

Yulong Ma ◽

Aisheng Hou ◽

Yuxiang Song ◽

Xin Sui ◽

...

Keyword(s):

Membrane Protein ◽

Protein Expression ◽

Learning And Memory ◽

Cognitive Dysfunction ◽

Adult Male ◽

Excitatory Amino Acid ◽

Postoperative Cognitive Dysfunction ◽

Male Mice ◽

Membrane Protein Expression

Abstract Background: Studies have shown that excitatory amino acid transporter 3 (EAAT3) function inhibition is related to several neurodegenerative diseases. Our previous studies also found that the EAAT3 function is intimately linked to learning and memory. In this study, we examined the role of EAAT3 in postoperative cognitive dysfunction (POCD) and explored the potential benefit of riluzole against POCD. Methods: We measured EAAT3 protein expression in hippocampus of male mice at different ages. Next, we established a recombinant adeno-associated viral (rAAV)-mediated shRNA to knockdown EAAT3 expression in the hippocampus of adult male mice. And then the mice received 2μg of lipopolysaccharide (LPS) intracerebroventricular microinjection to construct the POCD model. In addition, we intraperitoneally injected 4mg/kg of riluzole 2 days before LPS microinjection for consecutive 3 days in elderly male mice. Cognitive function was assessed using a Morris water maze 24h after LPS microinjection. Animal behavioral tests, as well as pathological and biochemical assays, were performed to clarify the role of EAAT3 function in POCD and evaluate the effect of activation of EAAT3 function by riluzole. Results: We found that the expression of EAAT3 was significantly decreased in old mice and EAAT3 knockdown in hippocampus aggravated LPS-induced learning and memory deficits in adult male mice. LPS significantly inhibited hippocampal EAAT3 membrane protein expression and GluA1 protein phosphorylation level in adult male mice. Moreover, riluzole pretreatment significantly increased hippocampal EAAT3 membrane protein expression and ameliorated LPS-induced cognitive impairment in old male mice. Conclusions: Our results demonstrated that the dysfunction of EAAT3 is an important risk factor for POCD susceptibility and riluzole may be a promising strategy for prevention and treating of POCD in the elderly people.

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Role of Sox2 in Learning, Memory, and Postoperative Cognitive Dysfunction in Mice

Cells ◽

10.3390/cells10040727 ◽

2021 ◽

Vol 10 (4) ◽

pp. 727

Author(s):

Lingli Gui ◽

Zhen Luo ◽

Weiran Shan ◽

Zhiyi Zuo

Keyword(s):

Learning And Memory ◽

Cognitive Dysfunction ◽

Environmental Enrichment ◽

Postoperative Cognitive Dysfunction ◽

Sirtuin 1 ◽

Immunofluorescent Staining ◽

Control Group ◽

Barnes Maze ◽

Clinical Issue

Postoperative cognitive dysfunction (POCD) is a significant clinical issue. Its neuropathogenesis has not been clearly identified and effective interventions for clinical use to reduce POCD have not been established. This study was designed to determine whether environmental enrichment (EE) or cognitive enrichment (CE) reduces POCD and whether sex-determining region Y-box-2 regulated by sirtuin 1, plays a role in the effect. Eighteen-month-old male mice were subjected to right-common-carotid-artery exposure under sevoflurane anesthesia. Some of them stayed in cages with EE or CE after the surgery. Learning and memory of mice were tested by a Barnes maze and fear conditioning, starting 2 weeks after the surgery. Sex-determining region Y-box-2 (Sox2) in the brain was silenced by small hairpin RNA (shRNA). Immunofluorescent staining was used to quantify Sox2-positive cells. Surgery reduced Sox2-positive cells in the hippocampus (64 ± 9 cells vs. 91 ± 9 cells in control group, n = 6, p < 0.001) and impaired learning and memory (time to identify target box one day after training sessions in the Barnes maze test: 132 ± 53 s vs. 79 ± 53 s in control group, n = 10, p = 0.040). EE or CE applied after surgery attenuated this reduction of Sox2 cells and POCD. Surgery reduced sirtuin 1 activity and CE attenuated this reduction. Resveratrol, a sirtuin 1 activator, attenuated POCD and surgery-induced decrease of Sox2-positive cells. Silencing shRNA reduced the Sox2-positive cells in the hippocampus and impaired learning and memory in mice without surgery. These results suggest a role of Sox2 in learning, memory, and POCD. EE and CE attenuated POCD via maintaining Sox2-positive cells in the hippocampus.

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Dysfunction of EAAT3 enhances LPS-induced Postoperative Cognitive Dysfunction

10.21203/rs.3.rs-141076/v3 ◽

2021 ◽

Author(s):

Xiaoyan Wang ◽

Yulong Ma ◽

Aisheng Hou ◽

Yuxiang Song ◽

Xin Sui ◽

...

Keyword(s):

Membrane Protein ◽

Protein Expression ◽

Learning And Memory ◽

Cognitive Dysfunction ◽

Adult Male ◽

Excitatory Amino Acid ◽

Postoperative Cognitive Dysfunction ◽

Male Mice ◽

Membrane Protein Expression

Abstract Background Studies have shown that excitatory amino acid transporter 3 (EAAT3) function inhibition is related to several neurodegenerative diseases. Our previous studies also found that the EAAT3 function is intimately linked to learning and memory. In this study, we examined the role of EAAT3 in postoperative cognitive dysfunction (POCD) and explored the potential benefit of riluzole against POCD. Methods We measured EAAT3 protein expression in hippocampus of male mice at different ages. Next, we established a recombinant adeno-associated viral (rAAV)-mediated shRNA to knockdown EAAT3 expression in the hippocampus of adult male mice. And then the mice received 2µg of lipopolysaccharide (LPS) intracerebroventricular microinjection to construct the POCD model. In addition, we intraperitoneally injected 4mg/kg of riluzole 2 days before LPS microinjection for consecutive 3 days in elderly male mice. Cognitive function was assessed using a Morris water maze 24h after LPS microinjection. Animal behavioral tests, as well as pathological and biochemical assays, were performed to clarify the role of EAAT3 function in POCD and evaluate the effect of activation of EAAT3 function by riluzole. Results We found that the expression of EAAT3 was significantly decreased in old mice and EAAT3 knockdown in hippocampus aggravated LPS-induced learning and memory deficits in adult male mice. LPS significantly inhibited hippocampal EAAT3 membrane protein expression and GluA1 protein phosphorylation level in adult male mice. Moreover, riluzole pretreatment significantly increased hippocampal EAAT3 membrane protein expression and ameliorated LPS-induced cognitive impairment in old male mice. Conclusions Our results demonstrated that the dysfunction of EAAT3 is an important risk factor for POCD susceptibility and riluzole may be a promising strategy for prevention and treating of POCD in the elderly people.

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Locally Activated Mitophagy Contributes to a “built-in” Protection Against Early Burn-wound Progression in Rats Following a Regulation of HIF-1α

10.21203/rs.3.rs-55910/v1 ◽

2020 ◽

Author(s):

Songxue Guo ◽

Quan Fang ◽

Leilei Chen ◽

Meirong Yu ◽

Yike Chen ◽

...

Keyword(s):

Mitochondrial Damage ◽

The Novel ◽

Burn Wound ◽

Burn Wounds ◽

Self Defense ◽

Transmission Electron ◽

Regulatory Effects ◽

Commercial Kits ◽

Novel Concept

Abstract Background: Deep burn wounds undergo a dynamic progression in the initial or periburn area after insults. The zone of stasis has a higher risk of deterioration and is considered a salvageable target for burn-wound progression. Few studies have explored the role of mitochondrial damage in this process and potential “built-in” self-defense within the human body.Methods: A classic “comb” scald rat model was established in this study. Histological and blood-flow observation were processed based on hematoxylin-eosin staining and laser analysis. Oxidative and apoptotic status were analyzed by commercial kits. Transmission electron microscope, immunofluorescence staining, and western blot were applied to detect the mitophagy happened in the zone of stasis and potential regulators. Adenovirus-based gene-silence contributed to determine the role of HIF-1 as a regulatory mediator. Results: We found that burn insults caused typical ischemia and histological deterioration in the zone of stasis, in parallel with increases in oxidative stress and apoptosis. Mitochondrial damage was also involved in the aforementioned changes. Furthermore, we detected typical mitophagy in burn wounds, which was contradictory to the burn-wound conversion. HIF-1 expression was closely related to the level of mitophagy, while BNIP3 and PARKIN are involved downstream. Conclusion: We demonstrate that burn-induced mitochondrial impairment contributes to the mobilization of injurious mechanisms in the zone of stasis and that mitophagy provides a more beneficial way to protect against burn-wound progression via the elimination of damaged mitochondria. Our findings offer insights into mitochondrial quality control in burn-wound progression and suggest the novel concept that HIF-1 may be a potential therapeutic target due to its possible regulatory effects upstream of BNIP3- or PARKIN-mediated mitophagy.

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Nanoparticle elasticity regulates phagocytosis and cancer cell uptake

Science Advances ◽

10.1126/sciadv.aaz4316 ◽

2020 ◽

Vol 6 (16) ◽

pp. eaaz4316 ◽

Cited By ~ 9

Author(s):

Yue Hui ◽

Xin Yi ◽

David Wibowo ◽

Guangze Yang ◽

Anton P. J. Middelberg ◽

...

Keyword(s):

Cancer Cell ◽

Cell Uptake ◽

Receptor Interaction ◽

Transmission Electron ◽

Nanoparticle Interactions ◽

Wide Range ◽

The Impact ◽

Specific Ligand ◽

Silica Nanocapsules

The ability of cells to sense external mechanical cues is essential for their adaptation to the surrounding microenvironment. However, how nanoparticle mechanical properties affect cell-nanoparticle interactions remains largely unknown. Here, we synthesized a library of silica nanocapsules (SNCs) with a wide range of elasticity (Young’s modulus ranging from 560 kPa to 1.18 GPa), demonstrating the impact of SNC elasticity on SNC interactions with cells. Transmission electron microscopy revealed that the stiff SNCs remained spherical during cellular uptake. The soft SNCs, however, were deformed by forces originating from the specific ligand-receptor interaction and membrane wrapping, which reduced their cellular binding and endocytosis rate. This work demonstrates the crucial role of the elasticity of nanoparticles in modulating their macrophage uptake and receptor-mediated cancer cell uptake, which may shed light on the design of drug delivery vectors with higher efficiency.

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Dysfunction of EAAT3 Enhances LPS-induced Postoperative Cognitive Dysfunction

10.21203/rs.3.rs-141076/v2 ◽

2021 ◽

Author(s):

Xiaoyan Wang ◽

Yulong Ma ◽

Aisheng Hou ◽

Yuxiang Song ◽

Xin Sui ◽

...

Keyword(s):

Membrane Protein ◽

Protein Expression ◽

Learning And Memory ◽

Cognitive Dysfunction ◽

Adult Male ◽

Excitatory Amino Acid ◽

Postoperative Cognitive Dysfunction ◽

Male Mice ◽

Membrane Protein Expression

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Dysfunction of EAAT3 Enhances LPS-Induced Postoperative Cognitive Dysfunction

10.21203/rs.3.rs-141076/v1 ◽

2021 ◽

Author(s):

Xiaoyan Wang ◽

Yulong Ma ◽

Aisheng Hou ◽

Yuxiang Song ◽

Xin Sui ◽

...

Keyword(s):

Membrane Protein ◽

Protein Expression ◽

Learning And Memory ◽

Cognitive Dysfunction ◽

Adult Male ◽

Excitatory Amino Acid ◽

Postoperative Cognitive Dysfunction ◽

Male Mice ◽

Membrane Protein Expression

Abstract Background: Studies have shown that excitatory amino acid transporter 3 (EAAT3) function inhibition is related to several neurodegenerative diseases. Our previous studies also found that the EAAT3 function is intimately linked to learning and memory. In this study, we examined the role of EAAT3 in postoperative cognitive dysfunction (POCD) and explored the potential benefit of riluzole against POCD. Methods: We performed mutation analysis of SLC1A1 (encoding EAAT3) gene exons in patients of different age groups and measured EAAT3 protein expression in hippocampus of mice at different ages. Next, we established a recombinant adeno-associated viral (rAAV)-mediated shRNA to knockdown EAAT3 expression in the hippocampus of adult male mice. And then the mice received 2μg of lipopolysaccharide (LPS) intracerebroventricular microinjection to construct the POCD model. In addition, we intraperitoneally injected 4mg/kg of riluzole 2 days before LPS microinjection for consecutive 3 days in elderly male mice. Cognitive function was assessed using a Morris water maze 24h after LPS microinjection. Animal behavioral tests, as well as pathological and biochemical assays, were performed to clarify the role of EAAT3 function in POCD and evaluate the effect of activation of EAAT3 function by riluzole. Results: We found that point mutation of SLC1A1 gene exon in elderly patients was significantly different from children and adult people, and expression of EAAT3 was significantly decreased in old mice. And EAAT3 knockdown in hippocampus aggravated LPS-induced learning and memory deficits in adult male mice, and LPS significantly inhibited hippocampal EAAT3 membrane protein expression and GluA1 protein phosphorylation level in adult male mice. Moreover, riluzole pretreatment significantly increased hippocampal EAAT3 membrane protein expression and ameliorated LPS-induced cognitive impairment in old male mice. Conclusions: Our results demonstrated that the dysfunction of EAAT3 is an important risk factor for POCD susceptibility and riluzole may be a promising strategy for prevention and treating of POCD in the elderly people.

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On Future Directions in Pathology

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100053991 ◽

1982 ◽

Vol 40 ◽

pp. 274-277

Author(s):

Benjamin F. Trump ◽

Irene K. Berezesky ◽

Raymond T. Jones

Keyword(s):

Electron Microscopy ◽

Transmission Electron Microscopy ◽

Clinical Pathology ◽

Future Directions ◽

Diagnostic Pathology ◽

The Past ◽

Transmission Electron ◽

Organ Systems ◽

The Many

The role of electron microscopy and associated techniques is assured in diagnostic pathology. At the present time, most of the progress has been made on tissues examined by transmission electron microscopy (TEM) and correlated with light microscopy (LM) and by cytochemistry using both plastic and paraffin-embedded materials. As mentioned elsewhere in this symposium, this has revolutionized many fields of pathology including diagnostic, anatomic and clinical pathology. It began with the kidney; however, it has now been extended to most other organ systems and to tumor diagnosis in general. The results of the past few years tend to indicate the future directions and needs of this expanding field. Now, in addition to routine EM, pathologists have access to the many newly developed methods and instruments mentioned below which should aid considerably not only in diagnostic pathology but in investigative pathology as well.

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Transmission Electron Microscopy studies of texture of Cr underlayer of magnetic recording hard disk

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100087215 ◽

1991 ◽

Vol 49 ◽

pp. 580-581

Author(s):

L. Tang ◽

G. Thomas ◽

M. R. Khan ◽

S. L. Duan

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Magnetic Recording ◽

Magnetic Thin Films ◽

Magnetic Films ◽

Substrate Bias ◽

Epitaxial Relationship ◽

Transmission Electron

Cr thin films are often used as underlayers for Co alloy magnetic thin films, such as Co1, CoNi2, and CoNiCr3, for high density longitudinal magnetic recording. It is belived that the role of the Cr underlayer is to control the growth and texture of the Co alloy magnetic thin films, and, then, to increase the in plane coercivity of the films. Although many epitaxial relationship between the Cr underlayer and the magnetic films, such as ﹛1010﹜Co/ {110﹜Cr4, ﹛2110﹜Co/ ﹛001﹜Cr5, ﹛0002﹜Co/﹛110﹜Cr6, have been suggested and appear to be related to the Cr thickness, the texture of the Cr underlayer itself is still not understood very well. In this study, the texture of a 2000 Å thick Cr underlayer on Nip/Al substrate for thin films of (Co75Ni25)1-xTix dc-sputtered with - 200 V substrate bias is investigated by electron microscopy.

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Transmission Electron Microscopy of Evaporated Perylene Thin Films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100135289 ◽

1990 ◽

Vol 48 (2) ◽

pp. 336-337

Author(s):

C. Ewins ◽

J.R. Fryer

Keyword(s):

Electron Microscopy ◽

Thin Films ◽

Transmission Electron Microscopy ◽

Molecular Electronics ◽

High Vacuum ◽

Amorphous Layer ◽

Electric Heater ◽

Transmission Electron ◽

Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

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