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Current Alzheimer Research 2020We have recently identified Huntingtin (Htt), the pathogenic protein in Huntington's disease, as a mediator of Alzheimer's disease (AD) pathology in an amyloid precursor...
BACKGROUND
We have recently identified Huntingtin (Htt), the pathogenic protein in Huntington's disease, as a mediator of Alzheimer's disease (AD) pathology in an amyloid precursor protein (APP) knock-in mouse model of AD. That finding prompted us to examine if Htt is accumulated in the brains of AD patients and in which cell type Htt is present in the AD brain.
OBJECTIVE
To investigate whether location and levels of Htt are affected in hippocampus and frontal cortex in AD.
METHODS
Brains from AD patients (n=11) and controls (n=11) were stained for Htt using immunohistochemistry and signal intensity of Htt was quantified and localized in subregions and neurons. Confocal microscopy was used to characterize neuronal Htt localisation and its relationship with tau tangles and astrocytes.
RESULTS
Htt levels were increased in neuronal cells in the granular layer of the dentate gyrus, in CA1 and CA3 in hippocampus and in layer III of the frontal cortex. Htt was found in the soma, perinuclear space, thin neurites and nucleus of pyramidal neurons. Htt was present in neurons containing tau tangles but did not colocalize with astrocytes.
CONCLUSION
Htt accumulates in pyramidal neuron-rich areas including hippocampal subregions associated with memory and frontal cortex layer III. The accumulation of Htt in AD shows distinct cellular and morphological patterns and is not present in astrocytes. Clearly, further research is warranted to elucidate the role of Htt as a mediator of AD pathology and the potential use of Htt as a target in future therapeutic strategies.
Topics: Aged; Aged, 80 and over; Alzheimer Disease; Autopsy; Female; Frontal Lobe; Hippocampus; Humans; Huntingtin Protein; Male
PubMed: 33272184
DOI: 10.2174/1567205017666201203125622 -
Bulletin of Experimental Biology and... Dec 2020The data obtained by transcriptome analysis of lumbar spinal cord segments, sciatic nerve, and the respiratory diaphragm of the mice performed after a space flight on...
The data obtained by transcriptome analysis of lumbar spinal cord segments, sciatic nerve, and the respiratory diaphragm of the mice performed after a space flight on board Bion-M1 biosatellite were processed by bioinformatic methods aimed at elucidation of the regularities in hypogravity-induced transcriptome changes in various compartments of motor neurons. The study revealed abnormalities of axonal transport in spinal motor neurons provoked by weightlessness. These data agree with the results of electron microscopy examination of the spinal cord in experimental animals. In space group mice sacrificed on the landing day, the content of perinuclear ribosomes in lumbar motoneurons surpassed that in control mice or in the recovery group examined 1 week after the flight. The data corroborate our hypothesis on contribution of axonal transport disturbances into pathogenesis of hypogravity motor syndrome. They can be employed as a launching pad for further study of hypogravity-triggered motor disorder mechanisms in order to elaborate the preventive therapy against the development of hypogravity motor syndrome in space flights.
Topics: Animals; Axonal Transport; Axons; Computational Biology; Hypogravity; Lumbar Vertebrae; Male; Mice; Mice, Inbred C57BL; Microscopy, Electron; Motor Neurons; Ribosomes; Sciatic Nerve; Software; Space Flight; Spinal Cord; Transcriptome; Weightlessness
PubMed: 33263847
DOI: 10.1007/s10517-020-05048-5 -
BMC Ophthalmology Oct 2020Hurler syndrome-associated keratopathy is an exceedingly rare corneal disorder that requires corneal transplantation in advanced stages. Precise assessment of the...
BACKGROUND
Hurler syndrome-associated keratopathy is an exceedingly rare corneal disorder that requires corneal transplantation in advanced stages. Precise assessment of the corneal condition is necessary for deciding which type of keratoplasty (i.e., deep anterior lamellar or penetrating) should be proposed. We aimed to confront the results of multimodal imaging with those of histology in a case of Hurler syndrome-associated keratopathy.
CASE PRESENTATION
A 16-year-old patient with Hurler's syndrome treated with hematopoietic stem cell transplantation was referred for decreased vision related to advanced keratopathy. The patient was treated with deep anterior lamellar keratoplasty (DALK) in both eyes with uncomplicated outcome. Visual acuity improved from 0.1 (20/200) preoperatively to 0.32 (20/63) and 0.63 (20/32) after transplantation. The corneal endothelial cell density was 2400 cells/mm in both eyes 3 years after transplantation. In vivo confocal microscopy (IVCM) and spectral domain optical coherence tomography (SD-OCT) were performed preoperatively. The corneal buttons retrieved during keratoplasty were processed for histology. In SD-OCT scans, corneal opacities appeared as diffuse stromal hyperreflectivity associated with increased corneal thickness. IVCM showed diffuse cytoplasmic granular hyperreflectivity and rounded/ellipsoid aspects of keratocytes, presence of small intracellular vacuoles, and hyperreflective epithelial intercellular spaces. Bowman's layer was thin and irregular. The corneal endothelium was poorly visualized but no endothelial damage was observed. Histology showed irregular orientation and organization of stromal lamellae, with the presence of macrophages whose cytoplasm appeared clear and granular. A perinuclear clear halo was visible within the epithelial basal cells. Bowman's layer featured breaks and irregularities.
CONCLUSIONS
The observed corneal multimodal imaging features in mucopolysaccharidosis-related keratopathy were concordant with histology. Compared with standard histology, multimodal imaging allowed additional keratocyte features to be observed. It revealed both morphological and structural changes of all corneal layers but the endothelium. This information is essential for therapeutic management which should include DALK as the first-choice treatment in case of impaired visual acuity.
Topics: Adolescent; Corneal Diseases; Corneal Transplantation; Humans; Keratoplasty, Penetrating; Mucopolysaccharidosis I; Multimodal Imaging
PubMed: 33129306
DOI: 10.1186/s12886-020-01689-2 -
Memorias Do Instituto Oswaldo Cruz 2020Kaempferol (KPF) is a flavonoid with antiparasitic activity including experimental giardiasis which mechanism of action is unknown.
BACKGROUND
Kaempferol (KPF) is a flavonoid with antiparasitic activity including experimental giardiasis which mechanism of action is unknown.
OBJECTIVE
To analyse the cytotoxic effects of KPF on Giardia duodenalis trophozoites and to identify a likely parasite target of this compound.
METHODS
We used inhibitory concentrations of KPF (IC25, IC50 and IC100) and albendazole (ABZ) as reference drug. The ultrastructure of the trophozoites was analysed by transmission electron microscopy (TEM) whilst apoptosis/necrosis, production of reactive oxygen species (ROS) and cell cycle progression were assessed by flow cytometry (FCM) and confocal laser microscopy (CLM). Ligand-protein docking analyses were carried out using KPF structure from a drug library and crystal structure of a G. duodenalis aldose reductase (GdAldRed) homolog.
RESULTS
KPF provoked appearance of perinuclear and periplasmic spaces devoid of cytosolic content and multilamellar structures. KPF induced proapoptotic death associated with partial arrest in the S phase without ROS production. Bioinformatics approaches predicted that GdAldRed is a viable KPF target (ΔG = -7.09 kCal/mol), exhibiting 92% structural identity and a similar coupling pattern as its human homolog.
CONCLUSIONS
KPF exerted a proapoptotic effect on G. duodenalis trophozoites involving partial interruption of DNA synthesis without oxidative stress or structure damage to chromatin and cytoskeletal structures. GdAldRed is a likely target underlying its antigiardial activity.
Topics: Animals; Computational Biology; Giardia lamblia; Giardiasis; Humans; Kaempferols; Trophozoites
PubMed: 33111756
DOI: 10.1590/0074-02760200127 -
Nanomaterials (Basel, Switzerland) Oct 2020Barium ferrite nanoparticles (BaFeNPs) were investigated as vehicles for Ra radionuclide in targeted α-therapy. BaFe nanoparticles were labeled using a hydrothermal Ba...
Barium ferrite nanoparticles (BaFeNPs) were investigated as vehicles for Ra radionuclide in targeted α-therapy. BaFe nanoparticles were labeled using a hydrothermal Ba cations replacement by Ra with yield reaching 61.3 ± 1.8%. Radiolabeled nanoparticles were functionalized with 3-phosphonopropionic acid (CEPA) linker followed by covalent conjugation to trastuzumab (Herceptin). Thermogravimetric analysis and radiometric method with the use of [I]-labeled trastuzumab revealed that on average 19-21 molecules of trastuzumab are attached to the surface of one BaFe-CEPA nanoparticle. The hydrodynamic diameter of BaFe-CEPA-trastuzumab conjugate is 99.9 ± 3.0 nm in water and increases to 218.3 ± 3.7 nm in PBS buffer, and the zeta potential varies from +27.2 ± 0.7 mV in water to -8.8 ± 0.7 in PBS buffer. The [Ra]BaFe-CEPA-trastuzumab radiobioconjugate almost quantitatively retained Ra (>98%) and about 96% of Bi and 94% of Pb over 30 days. The obtained radiobioconjugate exhibited high affinity, cell internalization and cytotoxicity towards the human ovarian adenocarcinoma SKOV-3 cells overexpressing HER2 receptor. Confocal studies indicated that [Ra]BaFe-CEPA-trastuzumab was located in peri-nuclear space. High cytotoxicity of the [Ra]BaFe-CEPA-trastuzumab bioconjugate was confirmed by radiotoxicity studies on SKOV-3 cell monolayers and 3D-spheroids. In addition, the magnetic properties of the radiobioconjugate should allow for its use in guide drug delivery driven by magnetic field gradient.
PubMed: 33092037
DOI: 10.3390/nano10102067 -
Microscopy and Microanalysis : the... Dec 2020Finasteride is commonly used in the management of alopecia and nodular prostatic hyperplasia. It was reported to have a harmful effect on spermatogenesis with subsequent...
Finasteride is commonly used in the management of alopecia and nodular prostatic hyperplasia. It was reported to have a harmful effect on spermatogenesis with subsequent infertility. Thus, this research was to determine the ameliorative effect of resveratrol against testicular damage caused by finasteride. Forty adult male rats were randomly divided into four main groups: group I acted as the control, group II was administrated resveratrol 20 mg/kg/day, group III was administrated finasteride 5 mg/kg/day, and group IV was administrated finasteride and resveratrol as in the previous groups. Finasteride induced a significant decrement in the testosterone and dihydrotestosterone levels. The level of malondialdehyde significantly increased, while the levels of glutathione peroxidase, superoxide dismutase, and catalase significantly decreased in the finasteride-administrated rats. Variable histopathological alterations in the testes were revealed in the form of irregular seminiferous tubules. Some seminiferous tubules appeared with degenerated germinal epithelium. Others showed detachment of their germinal epithelium. Congested blood vessels and homogeneous acidophilic substance in-between tubules were also detected. A significant decrement in PCNA positive cells and a significant increment in Bax expression were demonstrated. Ultrastructural examination showed Sertoli cells with rarefied cytoplasm. Vacuolated cytoplasm, shrunken nuclei, and dilated perinuclear spaces were also revealed in the spermatogonia, primary spermatocytes, and early spermatids. On the contrary, few changes were noticed in rats received resveratrol concomitant with finasteride. This study indicated that resveratrol exerted a potent ameliorative effect against testicular injury caused by finasteride.
Topics: Animals; Finasteride; Male; Rats; Resveratrol; Seminiferous Tubules; Spermatogenesis; Testis
PubMed: 33012303
DOI: 10.1017/S1431927620024514 -
Microscopy (Oxford, England) Mar 2021Senile lentigo or age spots are hyperpigmented macules of skin that commonly develop following long-term exposure to ultraviolet radiation. This condition is caused by...
Senile lentigo or age spots are hyperpigmented macules of skin that commonly develop following long-term exposure to ultraviolet radiation. This condition is caused by accumulation of large numbers of melanosomes (melanin granules) produced by melanocytes within neighboring keratinocytes. However, there is still no consensus regarding the melanosome transfer mechanism in senile lentigo. To date, most pathohistological studies of skin have been two-dimensional and do not provide detailed data on the complex interactions of the melanocyte-keratinocyte network involved in melanosome transfer. We performed a three-dimensional reconstruction of the epidermal microstructure in senile lentigo using three different microscopic modalities to visualize the topological melanocyte-keratinocyte relationship and melanosome distribution. Confocal laser microscopy images showed that melanocyte dendritic processes are more frequently branched and elongated in senile lentigo skin than in normal skin. Serial transmission electron micrographs showed that dendritic processes extend into intercellular spaces between keratinocytes. Focused ion beam-scanning electron micrographs showed that dendritic processes in senile lentigo encircle adjacent keratinocytes and accumulate large numbers of melanosomes. Moreover, melanosomes transferred to keratinocytes are present not only in the supranuclear area but throughout the perinuclear area except on the basal side. The use of these different microscopic methods helped to elucidate the three-dimensional morphology and topology of melanocytes and keratinocytes in senile lentigo. We show that the localization of melanosomes in dendritic processes to the region encircling recipient keratinocytes contributes to efficient melanosome transfer in senile lentigo.
Topics: Adult; Aged; Extracellular Space; Female; Humans; Imaging, Three-Dimensional; Keratinocytes; Lentigo; Male; Melanocytes; Melanosomes; Microscopy, Confocal; Microscopy, Electron, Transmission; Middle Aged; Skin; Ultraviolet Rays
PubMed: 32991711
DOI: 10.1093/jmicro/dfaa054 -
Cells Sep 2020Cell migration requires reposition and reshaping of the cell nucleus. The nuclear lamina is highly important for migration of both primary and cancer cells. B-type...
Cell migration requires reposition and reshaping of the cell nucleus. The nuclear lamina is highly important for migration of both primary and cancer cells. B-type lamins are important for proper migration of epicardial cells and neurons and increased lamin B to lamin A ratio accelerates cancer cell migration through confined spaces. Moreover, a positive association between lamin B1 levels and tumor formation and progression is found in various cancer types. Still, the molecular mechanism by which B-type lamins promote cell migration is not fully understood. To better understand this mechanism, we tested the effects of lamin B1 on perinuclear actin organization. Here we show that induction of melanoma cell migration leads to the formation of a cytosolic Linker of Nucleoskeleton and Cytoskeleton (LINC) complex-independent perinuclear actin rim, which has not been detected in migrating cells, yet. Significantly, increasing the levels of lamin B1 but not the levels of lamin A prevented perinuclear actin rim formation while accelerated the cellular migration rate. To interfere with the perinuclear actin rim, we generated a chimeric protein that is localized to the outer nuclear membrane and cleaves perinuclear actin filaments in a specific manner without disrupting other cytosolic actin filaments. Using this tool, we found that disruption of the perinuclear actin rim accelerated the cellular migration rate in a similar manner to lamin B1 over-expression. Taken together, our results suggest that increased lamin B1 levels can accelerate cell migration by inhibiting the association of the nuclear envelope with actin filaments that may reduce nuclear movement and deformability.
Topics: Actins; Cell Line, Tumor; Cell Movement; Cell Nucleus; Gelsolin; Humans; Lamin Type B; Melanoma
PubMed: 32987785
DOI: 10.3390/cells9102161 -
JACC. Basic To Translational Science Aug 2020Excessive autophagy induces a defined form of cell death called autosis, which is characterized by unique morphological features, including ballooning of perinuclear... (Review)
Review
Excessive autophagy induces a defined form of cell death called autosis, which is characterized by unique morphological features, including ballooning of perinuclear space and biochemical features, including sensitivity to cardiac glycosides. Autosis is observed during the late phase of reperfusion after a period of ischemia and contributes to myocardial injury. This review discusses unique features of autosis, the involvement of autosis in myocardial injury, and the molecular mechanism of autosis. Because autosis promotes myocardial injury under some conditions, a better understanding of autosis may lead to development of novel interventions to protect the heart against myocardial stress.
PubMed: 32875173
DOI: 10.1016/j.jacbts.2020.04.014 -
Journal of Microscopy and Ultrastructure 2020Polychlorinated biphenyl (PCB) is considered one of the environmental pollutants. It is used as hydraulic coils in vacuum pumps, pesticides transformers, heat-exchange...
INTRODUCTION
Polychlorinated biphenyl (PCB) is considered one of the environmental pollutants. It is used as hydraulic coils in vacuum pumps, pesticides transformers, heat-exchange systems, capacitors and as additives in adhesive inks, paints, plastics, copying paper and sealants. Alpha lipoic acid (ALA) is an antioxidant substance normally present in mitochondria as a coenzyme.
AIM OF THE WORK
To evaluate the protective effect of ALA on PCB induced testicular toxicity.
MATERIALS AND METHODS
Twenty five adult male albino rats were used in this study. They were divided into four groups, a control group included 10 rats, group II rats received alpha lipoic acid 25mg/Kg /day orally for 30 days, group III rats received PCB 5mg /Kg/day orally for 30 days and group IV rats received both PCB and alpha lipoic acid at the same previous dose for 30 days. At the appropriate time, the specimens were taken and prepared for light and electron microscope study.
RESULTS
LM examination revealed structural alterations in group III in the form of wide spaces between seminiferous tubules that contain homogeneous acidophilic substance, partial or complete detachment of the tubules from the basement membrane and total distorted irregular shaped tubules. Also dilated congested blood vessels were seen. EM examination of this group revealed Sertoli cells with cytoplasmic vacuolation and dilated rER. The basement membrane appeared as thick and irregular line under Sertoli and spermatogenic cells and it was interrupted in some points. Primary spermatocyte appeared shrunken while others revealed vacuoles in the cytoplasm and perinuclear dilatation. Leydig cells showed irregular vacuoles and swollen destroyed mitochondria. Amelioration of the previous histological changes could be detected in group IV.
CONCLUSION
It could be concluded that alpha-lipoic acid has a protective effect against PCB induced testicular toxicity.
PubMed: 32766117
DOI: 10.4103/JMAU.JMAU_34_19