scholarly journals Transplanted Human Oligodendrocyte Progenitor Cells Restore Neurobehavioral Deficits in a Rat Model of Preterm White Matter Injury

2021 ◽  
Vol 12 ◽  
Author(s):  
Xiaohua Wang ◽  
Jing Zang ◽  
Yinxiang Yang ◽  
Siliang Lu ◽  
Qian Guan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
White Matter ◽  
Rat Model ◽  
Water Maze ◽  
White Matter Injury ◽  
Morris Water Maze Test ◽  
Oligodendrocyte Progenitor Cells ◽  
Maze Test ◽  
Transmission Electron

Background: Preterm white matter injury (PWMI) is a common brain injury and a leading cause of life-long neurological deficits in premature infants; however, no effective treatment is available yet. This study aimed to investigate the fate and effectiveness of transplanted human oligodendrocyte progenitor cells (hOPCs) in a rat model of PWMI.Methods: Hypoxia-ischemia was induced in rats at postnatal day 3, and hOPCs (6 × 105 cells/5 μL) were intracerebroventricularly transplanted at postnatal day 7. Neurobehavior was assessed 12 weeks post-transplant using the CatWalk test and Morris water maze test. Histological analyses, as well as immunohistochemical and transmission electron microscopy, were performed after transcardial perfusion.Results: Transplanted hOPCs survived for 13 weeks in PWMI brains. They were widely distributed in the injured white matter, and migrated along the corpus callosum to the contralateral hemisphere. Notably, 82.77 ± 3.27% of transplanted cells differentiated into mature oligodendrocytes, which produced myelin around the axons. Transplantation of hOPCs increased the fluorescence intensity of myelin basic protein and the thickness of myelin sheaths as observed in immunostaining and transmission electron microscopy, while it reduced white matter atrophy at the level of gross morphology. With regard to neurobehavior, the CatWalk test revealed improved locomotor function and inter-paw coordination after transplantation, and the cognitive functions of hOPC-transplanted rats were restored as revealed by the Morris water maze test.Conclusions: Myelin restoration through the transplantation of hOPCs led to neurobehavioral improvements in PWMI rats, suggesting that transplanting hOPCs may provide an effective and promising therapeutic strategy in children with PWMI.

scholarly journals Activin A Improves White Matter Injury in Neonatal Rats via Noggin/bmp4/id2 Signaling

2021 ◽  
Author(s):  
Xiaojuan Su ◽  
Jun Tang ◽  
Lingyi Huang ◽  
Dongqiong Xiao ◽  
Xia Qiu ◽  
...  
Keyword(s):  
White Matter ◽  
Rat Model ◽  
Myelin Sheath ◽  
Immunofluorescence Staining ◽  
White Matter Injury ◽  
Morris Water Maze Test ◽  
Oligodendrocyte Progenitor Cells ◽  
Protective Effects ◽  
Neonatal Rats

Abstract BackgroundActivin A (Act A) has been revealed to enhance the differentiation of oligodendrocyte progenitor cells (OPCs) in vitro. Here we aim to elucidate its roles and mechanisms in a rat model of white matter injury (WMI). MethodsAct A was injected into the lateral ventricle of a hypoxia-ischemia induced WMI rat model. Hematoxylin & eosin staining was used to detect pathological changes. Immunofluorescence staining was used to assess OPC proliferation, migration, apoptosis, and differentiation. Myelin sheath and axon formation were detected via immunofluorescence staining, Western blotting, and electron microscopy. Behavioral assessment of rats was performed with the Morris water maze test. ResultsAct A attenuated the pathological damages, enhanced the formation of myelin sheath and myelinated axons and improved the behavior of WMI rats by promoting OPC proliferation and differentiation. However, Act A showed no significant effects on OPC migration or apoptosis. Interestingly, we found that Act A could enhance Noggin expression, which in turn inhibited the expression of bone morphogenetic protein 4 (BMP4) and inhibitor of DNA binding 2 (Id2). Furthermore, upregulation of Id2 completely abolished the protective effects of Act A in WMI. ConclusionsAct A improves WMI in neonatal rats via Noggin/BMP4/Id2 signalling.

scholarly journals Biochanin A Attenuates Ovariectomy-Induced Cognition Deficit via Antioxidant Effects in Female Rats

2021 ◽  
Vol 12 ◽  
Author(s):  
Yanmeng Zhou ◽  
Bingbing Xu ◽  
Haiyang Yu ◽  
Wei Zhao ◽  
Xinxin Song ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Hippocampal Neurons ◽  
Water Maze ◽  
Caspase 3 ◽  
Morphological Changes ◽  
Primary Cultures ◽  
Biochanin A ◽  
Morris Water Maze Test ◽  
Maze Test ◽  
Ovx Rats

Background: Impairment of memory and cognition is one of the major symptoms in women with postmenopausal disorders due to estrogen deficiency, which accounts for the much higher prevalence of Alzheimer’s disease in females. Biochanin A (BCA), a natural phytoestrogen, has been reported to protect neurons against ischemic brain injury. However, the neuroprotective effects of BCA in the postmenopausal-like model of ovariectomized (OVX) rats remain to be investigated.Methods: All the rats except for the sham group underwent the resection of bilateral ovaries. Seven days after the OVX surgery, rats were randomly divided into six groups: sham, OVX, OVX + BCA (5 mg/kg), OVX + BCA (20 mg/kg), OVX + BCA (60 mg/kg), and OVX + estradiol (E2; 0.35 mg/kg), which were administrated daily by gavage for 12 weeks. Learning and memory were examined using the Morris water-maze test before the end of the experiment. Morphological changes of the rat hippocampus were observed by HE staining and electron microscopy. Malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-Px) in the hippocampus were measured. The effect of BCA on cell viability was measured in the presence of hydrogen peroxide (H2O2) using CCK8. Flow cytometry was used to measure neuronal apoptosis and reactive oxygen species (ROS) induced by H2O2. Expression of Bcl-2, Bax, and Caspase-3 was determined by Western blotting using hippocampal tissues and primary cultures of hippocampal neurons.Results: Chronic treatment with BCA mimicked the ability of E2 to reverse the deficit of learning and memory in the Morris water-maze test in OVX rats. BCA normalized OVX-induced morphological changes as revealed by HE staining and electron microscopy. In addition, BCA significantly decreased the levels of MDA, the biomarker of oxidative damage, and increased the activity of the intracellular antioxidant enzymes SOD and GSH-Px in OVX rats. Further, in primary cultures of hippocampal neurons, BCA reversed H2O2-induced decreases in cell viability and accumulation of ROS. Finally, BCA reversed OVX- or H2O2-induced increases in Bax and Caspase-3 and decreases in Bcl-2 in the hippocampus and primary cultures of hippocampal neurons.Conclusion: These results suggest that BCA improves memory through its neuroprotective properties in the brain under the circumstance of estrogen deficiency and can be used for treatment of memory loss in postmenopausal women.

scholarly journals Effect Mechanism of Electroacupuncture at ST36 on the Injured Extensor Digitorum Longus in the Jumping Rat Model Based on mRNA-Seq Analysis

Biomedicines ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1849
Author(s):  
Qianqian Liu ◽  
Yanwei Guo ◽  
Rui Han
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rat Model ◽  
Extensor Digitorum Longus ◽  
Morphological Structure ◽  
Extensor Digitorum ◽  
Control Group ◽  
Natural Recovery ◽  
Transmission Electron ◽  
Recovery Group

The key target and regulatory mechanism of electroacupuncture of Zusanli (ST36) on extensor longus muscle injury in a jumping rat model were investigated. To this end, 24 female SD rats were randomly divided into the following four groups: no-treatment control group (NON), 6-week jumping group (J6O), electroacupuncture group after 6-week jumping (J6A), and natural recovery group after 6-week jumping (J6N). After 6 weeks of jumping, in the electroacupuncture group (J6A), electroacupuncture stimulation was applied at Zusanli(ST36) for 20 min per day over the course of 5 days. In the natural recovery group (J6N), rats were fastened with a special apparatus without electroacupuncture stimulation for 20 min at the same time. Transmission electron microscopy, transcriptome sequencing and analysis, Western blotting assay and immunofluorescence staining were performed at the end of our experiment. The recovery effect of J6A rats was more obvious than that of J6N rats and J6O rats as indicated by changes of infiltration of inflammatory cells and morphological structure. Notably, the morphological structure of J6A rats was closer to NON rats in the observation of transmission electron microscopy. CISH/STAT3 regulation was identified by mRNA-seq. The pro-inflammatory response to STAT3 activation was alleviated through up-regulating the expression of CISH protein in J6A rats relative to J6O rats. The level of BAX was decreased and the level of Bcl-2 level was increased in J6A rats relative to J6O rats. Moreover, when compared to J6N rats, the level of Bcl-2 was significantly up-regulated in J6A rats. Increased caspase-3 expression but decreased CDKN2α expression was shown in J6A rats relative to NON rats. These results indicate that the potential mechanism underlying electroacupuncture stimulation of Zusanli (ST36) in repairing the injured extensor digitorum longus following overused jumping may be attributed to CISH/STAT3 regulation of proteins associated with inflammation, apoptosis, and proliferation.

scholarly journals Exogenous Oligodendrocyte Progenitor Cell Transplantation Results in Structural and Functional Recovery in a Preterm Infant Cerebral White Matter Injury Rat Model

2021 ◽  
Author(s):  
Zhaoyan Wang ◽  
Leping Zhang ◽  
Yinxiang Yang ◽  
Qian Wang ◽  
Suqing Qu ◽  
...  
Keyword(s):  
White Matter ◽  
Corpus Callosum ◽  
Preterm Infant ◽  
Preterm Infants ◽  
Rat Model ◽  
Progenitor Cell ◽  
White Matter Injury ◽  
Morris Water Maze Test ◽  
Oligodendrocyte Progenitor Cell ◽  
Oligodendrocyte Progenitor

Abstract BackgroundCerebral white matter injury (WMI) is the most common brain injury in preterm infants; it leads to motor and developmental deficits and is often accompanied by cognitive impairment. WMI is characterized by the loss of pre-myelinating oligodendrocytes. Regeneration therapies for preterm neonates with WMI are still in the preclinical phase, among which oligodendrocyte progenitor cell (OPC) transplantation is a promising approach. One promising approach for treating preterm infants is cell replacement therapy, in which lost cells are replaced by human OPCs (hOPCs) derived from human neural stem cells (hNSCs). MethodsIn this study, we developed a method to induce the differentiation of hNSCs into hOPCs. OLIG2+/NG2+/PDGFRα+/O4+ hOPCs were enriched and transplanted into the corpus callosum of a preterm infant WMI rat model. ResultsTransplanted hOPCs survived and migrated throughout the major white matter tracts. Morphological differentiation of transplanted hOPCs was observed. Histology and Magnetic resonance imaging (MRI) revealed lesioned structural repair. Electron microscopy revealed the re-myelination of the axons in the corpus callosum. The Morris water maze test revealed a recovery of cognitive function. ConclusionsOur study showed that transplantation of hOPCs derived from hNSCs is a viable therapeutic strategy for cerebral WMI. The results of our study contribute to the further development of cell therapeutic strategies.

Techniques for Transmission Electron Microscopy of Fiber-Matrix Interfaces in Aluminum Alloy-Boron Composites by Ion Erosio

1971 ◽  
Vol 29 ◽  
pp. 204-205
Author(s):  
G. G. Shaw
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Aluminum Alloy ◽  
Electron Beam ◽  
Pure Aluminum ◽  
Ion Milling ◽  
Transmission Electron ◽  
Fiber Matrix ◽  
Ion Erosion ◽  
Row Of Fibers

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.

Direct Observation of Heat Exchanger Deposits by Cross Sectioning

1967 ◽  
Vol 25 ◽  
pp. 364-365
Author(s):  
R. W. Anderson ◽  
D. L. Senecal
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Heat Exchanger ◽  
Direct Observation ◽  
Cross Sections ◽  
Preparation Method ◽  
Specimen Preparation ◽  
Flowing Water ◽  
Transmission Electron ◽  
Deposit Layer

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

Two- or three-way observations of the identical cell elements within the same sections by LM, TEM and/or SEM

1978 ◽  
Vol 36 (2) ◽  
pp. 82-83 ◽  
Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Fine Structure ◽  
Light Microscopy ◽  
Thin Sections ◽  
Transmission Electron ◽  
Identical Cell ◽  
Electron Microscopes ◽  
Scanning Electron

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).

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