Disruption of spermatogenesis in the liver fluke, Fasciola hepatica by two artemisinin derivatives, artemether and artesunate

2016 ◽  
Vol 91 (1) ◽  
pp. 55-71 ◽  
Author(s):  
J.F. O'Neill ◽  
R.C. Johnston ◽  
L. Halferty ◽  
R.E.B. Hanna ◽  
G.P. Brennan ◽  
...  
Keyword(s):  
Structural Changes ◽  
Fasciola Hepatica ◽  
Cell Types ◽  
Spermatogenic Cells ◽  
Cellular Targets ◽  
Artemisinin Derivatives ◽  
Transmission Electron ◽  
Abnormal Cells ◽  
Abnormal Mitochondria

AbstractAn in vivo study in the laboratory rat model has been carried out to monitor changes to the spermatogenic cells in the testis tubules of adult Fasciola hepatica following treatment with the artemisinins, artemether and artesunate. Rats infected with the triclabendazole (TCBZ)-resistant Sligo isolate were dosed orally with artemether at a concentration of 200 mg/kg and flukes recovered at 24, 48 and 72 h post treatment (pt). Rats infected with the TCBZ-resistant Oberon isolate were dosed orally with artesunate at a concentration of 200 mg/kg and flukes recovered 24, 48, 72 and 96 h pt. The flukes were processed for histological and transmission electron microscope (TEM) examination. Changes to the spermatogenic cells were evident at 24 h pt with artemether. The spermatogonial and spermatocyte cells contained abnormal mitochondria, there were fewer spermatids and spermatozoa in the tubules than normal, and a number of cells showed signs of apoptosis. There was a further decline in cell numbers at 48 h pt and the organization of the spermatocyte and spermatid rosettes was atypical. Sperm formation had become abnormal and those spermatozoa present possessed only a single axoneme. By 72 h pt, the testis tubules were vacuolated and filled with abnormal cells and cell debris. Only spermatogonial cells could be identified and there was widespread evidence of apoptosis in the cells. Distinct cellular changes following artesunate treatment did not become apparent until 48 h pt. The changes seen were similar to those described for artemether, but were generally less severe at matching time-periods. The fine structural changes occurring in the spermatogenic cells were compared to those observed in other cell types and fluke tissues and the overall information was collated to identify the cellular targets for artemisinin action and to establish the time-line for drug action.

Adult triclabendazole-resistantFasciola hepatica: morphological changes in the tegument and gut followingin vivotreatment with artemether in the rat model

2009 ◽  
Vol 83 (2) ◽  
pp. 151-163 ◽  
Author(s):  
J.F. O'Neill ◽  
R.C. Johnston ◽  
L. Halferty ◽  
G.P. Brennan ◽  
J. Keiser ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Structural Changes ◽  
Liver Fluke ◽  
Fasciola Hepatica ◽  
Morphological Changes ◽  
Oral Route ◽  
Normal Morphology ◽  
Transmission Electron ◽  
Large Numbers

AbstractA study has been carried out to determine the morphological changes to the adult liver fluke,Fasciola hepaticaafter treatmentin vivowith artemether. Rats were infected with the triclabendazole-resistant Sligo isolate ofF. hepatica, dosed orally with artemether at a concentration of 200 mg/kg and flukes recovered at 24, 48 and 72 h post-treatment (p.t.). Surface changes were monitored by scanning electron microscopy and fine structural changes to the tegument and gut by transmission electron microscopy. Twenty-four hours p.t., the external surface showed minor disruption, in the form of mild swelling of the tegument. The tegumental syncytium and sub-tegumental tissues appeared relatively normal. Forty-eight and seventy-two hours p.t., disruption to the tegumental system increased, with isolated patches of surface blebbing and reduced production of secretory bodies by the tegumental cells being the main changes seen. The gastrodermal cells showed a relatively normal morphology 24 h p.t. By 48 h, large numbers of autophagic vacuoles and lipid droplets were present. Autophagy increased in magnitude by 72 h p.t. and substantial disruption to the granular endoplasmic reticulum was observed. Results from this study show that flukes treatedin vivowith artemether display progressive and time-dependent alterations to the tegument and gut. Disruption to the gut was consistently and substantially more severe than that to the tegument, suggesting that an oral route of uptake for this compound predominates. This is the first study providing ultrastructural information on the effect of an artemisinin compound against liver fluke.

The neural crest population responding to endothelin-3 in vitro includes multipotent cells

1997 ◽  
Vol 110 (14) ◽  
pp. 1673-1682 ◽  
Author(s):  
J.G. Stone ◽  
L.I. Spirling ◽  
M.K. Richardson
Keyword(s):  
Neural Crest ◽  
Schwann Cells ◽  
Cell Types ◽  
Developmental Potential ◽  
Colony Assay ◽  
Cellular Targets ◽  
Multipotent Cells ◽  
Endothelin 3

The peptide endothelin 3 (EDN3) is essential for normal neural crest development in vivo, and is a potent mitogen for quail truncal crest cells in vitro. It is not known which subpopulations of crest cells are targets for this response, although it has been suggested that EDN3 is selective for melanoblasts. In the absence of cell markers for different precursor types in the quail crest, we have characterised EDN3-responsive cell types using in vitro colony assay and clonal analysis. Colonies were analysed for the presence of Schwann cells, melanocytes, adrenergic cells or sensory-like cells. We provide for the first time a description of the temporal pattern of lineage segregation in neural crest cultures. In the absence of exogenous EDN3, crest cells proliferate and then differentiate. Colony assay indicates that in these differentiated cultures few undifferentiated precursors remain and there is a low replating efficiency. By contrast, in the presence of 100 ng/ml EDN3 differentiation is inhibited and most of the cells maintain the ability to give rise to mixed colonies and clones containing neural crest derivatives. A high replating efficiency is maintained. In secondary culture there was a progressive decline in the number of cell types per colony in control medium. This loss of developmental potential was not seen when exogenous EDN3 was present. Cell type analysis suggests two novel cellular targets for EDN3 under these conditions. Contrary to expectations, one is a multipotent precursor whose descendants include melanocytes, adrenergic cells and sensory-like cells; the other can give rise to melanocytes and Schwann cells. Our data do not support previous claims that the action of EDN3 in neural crest culture is selective for cells in the melanocyte lineage.

Ultrastructural changes to the tegumental system and gastrodermal cells of adult Fasciola hepatica following treatment in vivo with a commercial preparation of myrrh (Mirazid)

2016 ◽  
Vol 91 (6) ◽  
pp. 672-685 ◽  
Author(s):  
M.M.O. Abdelaal ◽  
G.P. Brennan ◽  
A. Abdel-Aziz ◽  
I. Fairweather
Keyword(s):  
Fasciola Hepatica ◽  
Ultrastructural Changes ◽  
Muscle Fibres ◽  
Somatic Muscle ◽  
Secretory Body ◽  
Commercial Preparation ◽  
Transmission Electron ◽  
Body Production ◽  
Tegumental Syncytium

AbstractAn in vivo study in the laboratory rat model has been carried out to monitor changes to the tegument and gut of adult Fasciola hepatica following treatment with myrrh (‘Mirazid’). Rats infected with the triclabendazole-resistant Dutch isolate were dosed orally with Mirazid at a concentration of 250 mg/kg and flukes recovered 2, 3 and 7 days post-treatment (pt). The flukes were processed for examination by scanning and transmission electron microscopy. A variety of changes to the external surface were observed, culminating in the sloughing of the tegumental syncytium. Internal changes to the syncytium and tegumental cell bodies were more severe and were evident from 2 days pt onwards. Swelling of the basal infolds (leading to flooding of the surface layer) and a decline in secretory body production were the major changes seen. The gastrodermal cells were less severely affected than the tegument, pointing to a trans-tegumental route of uptake for Mirazid by the fluke. Some loss of muscle fibres in the main somatic muscle layers was observed, which may be correlated with the decline in movement of flukes seen at recovery.

Abstract 12105: Targeted Delivery of Therapeutic Agents After Myocardial Infarction

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Siva Sai Krishna Dasa ◽  
Marc E Seamen ◽  
Brent A French ◽  
Kimberly A Kelly
Keyword(s):  
Myocardial Infarction ◽  
Phage Display ◽  
Targeted Delivery ◽  
Cell Types ◽  
Phage Display Library ◽  
Border Zone ◽  
Cell Type ◽  
Cellular Targets ◽  
Cell Type Specific

Introduction: Current therapies for heart failure (HF) after myocardial infarction (MI) only slow the progression of LV remodeling and have little capacity to regenerate cardiac muscle lost to MI. To expedite targeted delivery of regenerative therapies post-MI, we hypothesized that suitable targets could be identified by biopanning the heart with a phage display library in a mouse model of MI. Methods: A phage display library was biopanned in vivo to identify peptides specific for the infarct/border zone 4 days post-MI. Fluorescence molecular tomography (FMT) followed by tissue immunofluorescence was performed to interrogate the specificity of phage groups and individual clones with targeted phage at VT680 and neg control phage at VT750. The VT680 fluorophore on the targeted phage clones was then used to identify the cellular targets of those clones by counter-staining with antibodies against cell types of interest. Results: We identified phage clones specific for endothelium, cardiomyocytes, inflammatory fibroblasts and c-Kit+ cells present in the border zone post-MI. Liposomes conjugated with different cell type specific peptides had different accumulation rates in the post-infarct heart as visualized by FMT imaging (Fig. 1a). Immunofluorescence analysis demonstrated cell-type specific association of the targeted liposomes with cells expressing c-Kit, CD31 and Hrnr (Figs. 1b&c). We have also been successful in remote loading of anti-apoptotic and immune suppresive drugs into these liposomes and are currently studying their effect in mice after MI. Conclusions: Peptides identified by this screen enable the targeting of different cell types present in the border zone with different drugs. Identifying the molecular binding partners for these peptides may yield insight into the various events/pathways that evolve after a myocardial infarction.

scholarly journals A multi-layered and dynamic apical extracellular matrix shapes the vulva lumen in Caenorhabditis elegans

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Jennifer D Cohen ◽  
Alessandro P Sparacio ◽  
Alexandra C Belfi ◽  
Rachel Forman-Rubinsky ◽  
David H Hall ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Caenorhabditis Elegans ◽  
Cell Types ◽  
Extracellular Matrices ◽  
Cell Type ◽  
Transmission Electron ◽  
Genetic Perturbations ◽  
Lipid Transporters ◽  
Matrix Factors

Biological tubes must develop and maintain their proper diameter to transport materials efficiently. These tubes are molded and protected in part by apical extracellular matrices (aECMs) that line their lumens. Despite their importance, aECMs are difficult to image in vivo and therefore poorly understood. The Caenorhabditis elegans vulva has been a paradigm for understanding many aspects of organogenesis. Here we describe the vulva luminal matrix, which contains chondroitin proteoglycans, Zona Pellucida (ZP) domain proteins, and other glycoproteins and lipid transporters related to those in mammals. Confocal and transmission electron microscopy revealed, with unprecedented detail, a complex and dynamic aECM. Different matrix factors assemble on the apical surfaces of each vulva cell type, with clear distinctions seen between Ras-dependent (1°) and Notch-dependent (2°) cell types. Genetic perturbations suggest that chondroitin and other aECM factors together generate a structured scaffold that both expands and constricts lumen shape.

scholarly journals A multi-layered and dynamic apical extracellular matrix shapes the vulva lumen in Caenorhabditis elegans

2020 ◽  
Author(s):  
Jennifer D. Cohen ◽  
Alessandro P. Sparacio ◽  
Alexandra C. Belfi ◽  
Rachel Forman-Rubinsky ◽  
David H. Hall ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Cell Types ◽  
Extracellular Matrices ◽  
Cell Type ◽  
C Elegans ◽  
Transmission Electron ◽  
Genetic Perturbations ◽  
Lipid Transporters ◽  
Matrix Factors

AbstractBiological tubes must develop and maintain their proper diameter in order to transport materials efficiently. These tubes are molded and protected in part by apical extracellular matrices (aECMs) that line their lumens. Despite their importance, aECMs are difficult to image in vivo and therefore poorly understood. The C. elegans vulva has been a paradigm for understanding many aspects of organogenesis. Here we describe the vulva luminal matrix, which contains chondroitin proteoglycans, Zona Pellucida (ZP) domain proteins, and other glycoproteins and lipid transporters related to those in mammals. Confocal and transmission electron microscopy revealed, with unprecedented detail, a complex and dynamic aECM. Different matrix factors assemble on the apical surfaces of each vulva cell type, with clear distinctions seen between Ras-dependent (1°) and Notch-dependent (2°) cell types. Genetic perturbations suggest that chondroitin and other aECM factors together generate a structured scaffold that both expands and constricts lumen shape.

The Massaria disease of plane trees:its wood decay mechanism

IAWA Journal ◽  
2014 ◽  
Vol 35 (4) ◽  
pp. 395-406 ◽  
Author(s):  
Uwe Schmitt ◽  
Benjamin Lüer ◽  
Dirk Dujesiefken ◽  
Gerald Koch
Keyword(s):  
Cell Walls ◽  
Parenchyma Cell ◽  
Middle Lamella ◽  
Wood Decay ◽  
Cell Types ◽  
Cell Corner ◽  
Transmission Electron ◽  
Parenchyma Cells ◽  
Decay Pattern

Branches of Platanus × hispanica with distinct symptoms of the Massaria disease were investigated by light and transmission electron microscopy and cellular UVmicrospectrophotometry. The samples collected in the city of Mannheim, Germany, were infected in vivo with the fungus Splanchnonema platani and showed various degrees of wood decay. The investigations were focused on the decay pattern of cell walls in the different cells, i.e., fibres, vessels as well as ray and axial parenchyma cells. The following results were obtained. Hyphae of the ascomycete fungus Splanchnonema platani penetrated from cell to cell through the pits and not through the cell wall middle lamella, by the formation of thin perforation hyphae. During this process, the 1–5 μm thick hyphae became narrower without attacking the wall around the pit canal. After penetration through a pit, the hyphae again enlarged to their original diameter. This is true for all pit pairs connecting the various cell types. Late decay stages did not show a decay of cell corner regions and middle lamellae of fibres as well as vessel and parenchyma cell walls. Phenolic deposits in parenchyma cells were still present in severely attacked xylem tissue. These features point to a low lignolytic capacity of the fungus. The frequently found microscopic decay pattern with the formation of oval or spherical cavities in the S2 layer of the secondary wall with an often structurally intact S3 layer is a characteristic of softrot decay. This classification is also supported by the remaining cell corner and middle lamella regions in advanced decay stages. As a consequence of this decay type, branches fracture in a brittle mode.

Ultrastructural changes to the tegumental system and the gastrodermal cells in adult Fasciola hepatica following in vivo treatment with the experimental fasciolicide, compound alpha

Parasitology ◽  
2009 ◽  
Vol 136 (6) ◽  
pp. 665-680 ◽  
Author(s):  
M. McCONVILLE ◽  
G. P. BRENNAN ◽  
A. FLANAGAN ◽  
H. W. J. EDGAR ◽  
R. CASTILLO ◽  
...  
Keyword(s):  
Bile Ducts ◽  
Fasciola Hepatica ◽  
Secretory Activity ◽  
Ultrastructural Changes ◽  
Muscle Fibres ◽  
Somatic Muscle ◽  
Tegumental Cell ◽  
Transmission Electron ◽  
Tegumental Syncytium

SUMMARYSheep infected with the triclabendazole-susceptible, Cullompton isolate of Fasciola hepatica were dosed with 15 mg/kg of compound alpha at 12 weeks post-infection. Adult flukes were recovered from the bile ducts at 24, 48 and 72 h post-treatment (p.t.). Ultrastructural changes to the flukes were assessed using transmission electron microscopy (TEM), with a view to gathering information on the mechanism(s) of action for compound alpha and on the possible route of its entry into F. hepatica. The tegumental syncytium was more severely affected than the gut at all time-points p.t. with compound alpha, suggesting a predominantly trans-tegumental route of uptake. Disruption to the tegumental system became increasingly severe over time. A stress response was observed at 24 h p.t. and took the form of blebbing and increases in the production and transport of secretory bodies. By 72 h p.t., extensive tegumental loss and degeneration of the tegumental cell bodies had occurred. Degeneration of subtegumental tissues and internal flooding were also observed. Changes in the gastrodermal cells were slow to develop: reduced secretory activity was evident at 72 h p.t.. There was progressive disruption to the somatic muscle layers, with disorganization of the muscle blocks and loss of muscle fibres.

Effects of the substratum on the migration of primordial germ cells

1982 ◽  
Vol 299 (1095) ◽  
pp. 177-183 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Cell Migration ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Cell Types ◽  
Artificial Substrates ◽  
Transmission Electron ◽  
Migratory Cells

It is now clear from work on defined cell types on artificial substrates that various chemical and physical inhomogeneities in the substrates can guide cell locomotion. It is also becoming clear that less well defined inhomogeneities in living cell substrates can guide the normal locomotion of embryonic migratory cells in vivo. The primordial germ cells (p.g.cs) of early anuran amphibian embryos are proving a useful model for the study of cell migration. When isolated from the embryo and cultured on living cellular substrate, p.g.cs become oriented by the shapes of the underlying cells or by their stress fibre cytoskeleton, or both. A combination of scanning and transmission electron microscopy in vivo shows a clearly aligned cellular substrate for p.g.c. migration along part of their route. Furthermore, we find that the glycoprotein fibronectin is involved in p.g.c. adhesion, which suggests a link between orientation of the substrate cells and p.g.c. guidance.

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