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Fulltext Proteomes, kinases and signalling pathways in virus-induced filopodia, as potential antiviral therapeutics targets

Aliyu IA, Kumurya AS, Bala JA, Yahaya H, Saidu H

Rev Med Virol, 2021 Sep;31(5):1-9.
PMID: 33314425 DOI: 10.1002/rmv.2202

Filopodia are thin finger-like protrusions at the surface of cells that are internally occupied with bundles of tightly parallel actin filaments. They play significant roles in cellular physiological processes, such as adhesion to extracellular matrix, guidance towards chemo-attractants and in wound healing. Filopodia were recently reported to play important roles in viral infection including initial viral attachment to host cells, cell surfing, viral trafficking, internalization, budding, virus release and spread to other cells in a form that would avoid the host immune system. The detailed virus-host protein interactions underlying most of these processes remain to be elucidated. This review will describe some reported virus-host protein interactions on filopodia with the aim of identifying potential new anti-virus therapeutic targets. Exploring this research area may lead to the development of novel classes of anti-viral therapeutics that can block signalling pathways used by the virus to trigger filopodia formation. Successful compounds would inhibit initial virus attachment, formation of filopodia, expression of putative virus binding protein, extracellular virus trafficking, and budding.

Matched MeSH terms: Pseudopodia/metabolism*; Pseudopodia/physiology
Amoeboid form of Blastocystis hominis - a detailed ultrastructural insight

Tan TC, Suresh KG

Parasitol Res, 2006 Nov;99(6):737-42.
PMID: 16816959

The amoeboid form of Blastocystis hominis has been reported infrequently, and its morphological descriptions have yielded conflicting and confusing reports. In the present study, we used the amoeboid forms seen predominantly in symptomatic patients infected with Blastocystis to provide detailed descriptions on the fine surface structure and intracellular morphology. Scanning electron microscopy revealed the irregular shape of the amoeboid form, with an intercalated fibrillar structure and a highly convoluted surface with deep indentations and projected pseudopodia. Transmission electron microscopy showed the existence of two types of amoeboid forms of B. hominis in in vitro culture, one with a large central vacuole containing tiny electron-dense particles while the other contains multiple small vacuoles in the cytoplasm. A surface coat with varying thickness surrounded the amoeboid form, which also showed prominent, extended pseudopodia of varying shape. Irregularly shaped mitochondrion-like organelles with prominent cristae, lipid inclusions, and multiple vacuoles were frequently seen in close proximity with the pseudopodia. The characteristic nucleus with a crescentic band of electron-dense chromatin material was also seen.

Matched MeSH terms: Pseudopodia/ultrastructure
Cellular protrusions--lamellipodia, filopodia, invadopodia and podosomes--and their roles in progression of orofacial tumours: current understanding

Alblazi KM, Siar CH

Asian Pac J Cancer Prev, 2015;16(6):2187-91.
PMID: 25824735

BACKGROUND: Protrusive structures formed by migrating and invading cells are termed lamellipodia, filopodia, invadopodia and podosomes. Lamellipodia and filopodia appear on the leading edges of migrating cells and function to command the direction of the migrating cells. Invadopodia and podosomes are special F-actin-rich matrix-degrading structures that arise on the ventral surface of the cell membrane. Invadopodia are found in a variety of carcinomatous cells including squamous cell carcinoma of head and neck region whereas podosomes are found in normal highly motile cells of mesenchymal and myelomonocytic lineage. Invadopodia-associated protein markers consisted of 129 proteins belonging to different functional classes including WASP, NWASP, cortactin, Src kinase, Arp 2/3 complex, MT1-MMP and F-actin. To date, our current understanding on the role(s) of these regulators of actin dynamics in tumors of the orofacial region indicates that upregulation of these proteins promotes invasion and metastasis in oral squamous cell carcinoma, is associated with poor/worst prognostic outcome in laryngeal cancers, contributes to the persistent growth and metastasis characteristics of salivary gland adenoid cystic carcinoma, is a significant predictor of increased cancer risk in oral mucosal premalignant lesions and enhances local invasiveness in jawbone ameloblastomas.

Matched MeSH terms: Pseudopodia/pathology
Ultrastructural aspects of sylvatic dengue virus infection in Vero cell

Fish-Low CY, Abubakar S, Othman F, Chee HY

Malays J Pathol, 2019 Apr;41(1):41-46.
PMID: 31025636

INTRODUCTION: Dengue virus (DENV), the causative agent of dengue disease exists in sylvatic and endemic ecotypes. The cell morphological changes and viral morphogenesis of two dengue ecotypes were examined at the ultrastructural level to identify potential similarities and differences in the surrogate model of enzootic host.
MATERIALS AND METHODS: Vero cells were inoculated with virus at a multiplicity of infection (MOI) of 0.1. Cell cultures were harvested over a time course and processed for transmission electron microscopic imaging.
RESULTS: The filopodia protrusions on cell periphery preceded virus entry. Additionally, sylvatic DENV infection was found spreading slower than the endemic DENV. Morphogenesis of both dengue ecotypes was alike but at different level of efficiency in the permissive cells.
CONCLUSIONS: This is the first ultrastructural study on sylvatic DENV and this comparative study revealed the similarities and differences of cellular responses and morphogenesis of two dengue ecotypes in vitro. The study revealed the weaker infectivity of sylvatic DENV in the surrogate model of enzootic host, which supposed to support better replication of enzootic DENV than endemic DENV.

Matched MeSH terms: Pseudopodia
Fulltext Morphological change of human exfoliated deciduous teeth and the effect of vascular endothelial growth factor on human amniotic membrane scaffold

Md Hashim, S.N., Yusof, M.F.H., Alshehadat, S.A., Kannan, T.P., Azlina, A., Suzina, S.A.H., et al.

Malaysian Journal of Microscopy, 2015;11(1):22-27.
MyJurnal

Angiogenicity is one of the essential components to enable tissue function. It is important to develop a construct that would help in catering oxygen and nutrient to the engineered tissue area. Thus, this study aims to investigate the attachment, spreading and growth of stem cells from human exfoliated deciduous teeth (SHED) on human AM (HAM) with or without vascular endothelial growth factor (VEGF) using scanning electron microscope (SEM), and indirectly see the potential of the HAM as a scaffold to promote angiogenic micro-environment. Since day 1, there were continuous changes of the cell morphology until day 28, SHED treated with VEGF seemed to change its shape from fibroblast-like into a round-shape cell, similar structure as an endotheliallike cell. The structures of filopodia-like were also observed on the treated SHED. SHED without VEGF treatment showed only normal morphological growth on HAM. VEGF is a protein produced to stimulate angiogenesis, and is believed to contribute to the morphological changes of SHED seeded on HAM. This indicates that HAM could be used as a scaffold to allow SHED differentiation into endothelial-like cells with the induction of VEGF.

Matched MeSH terms: Pseudopodia
Fulltext Attachment, Proliferation, and Morphological Properties of Human Dermal Fibroblasts on Ovine Tendon Collagen Scaffolds: A Comparative Study

Busra FM, Lokanathan Y, Nadzir MM, Saim A, Idrus RBH, Chowdhury SR

Malays J Med Sci, 2017 Mar;24(2):33-43.
PMID: 28894402 DOI: 10.21315/mjms2017.24.2.5

INTRODUCTION: Collagen type I is widely used as a biomaterial for tissue-engineered substitutes. This study aimed to fabricate different three-dimensional (3D) scaffolds using ovine tendon collagen type I (OTC-I), and compare the attachment, proliferation and morphological features of human dermal fibroblasts (HDF) on the scaffolds.
METHODS: This study was conducted between the years 2014 to 2016 at the Tissue Engineering Centre, UKM Medical Centre. OTC-I was extracted from ovine tendon, and fabricated into 3D scaffolds in the form of sponge, hydrogel and film. A polystyrene surface coated with OTC-I was used as the 2D culture condition. Genipin was used to crosslink the OTC-I. A non-coated polystyrene surface was used as a control. The mechanical strength of OTC-I scaffolds was evaluated. Attachment, proliferation and morphological features of HDF were assessed and compared between conditions.
RESULTS: The mechanical strength of OTC-I sponge was significantly higher than that of the other scaffolds. OTC-I scaffolds and the coated surface significantly enhanced HDF attachment and proliferation compared to the control, but no differences were observed between the scaffolds and coated surface. In contrast, the morphological features of HDF including spreading, filopodia, lamellipodia and actin cytoskeletal formation differed between conditions.
CONCLUSION: OTC-I can be moulded into various scaffolds that are biocompatible and thus could be suitable as scaffolds for developing tissue substitutes for clinical applications and in vitro tissue models. However, further study is required to determine the effect of morphological properties on the functional and molecular properties of HDF.

Matched MeSH terms: Pseudopodia
Fulltext Potential anti-Acanthamoeba and anti-adhesion activities of Annona muricata and Combretum trifoliatum extracts and their synergistic effects in combination with chlorhexidine against Acanthamoeba triangularis trophozoites and cysts

Mitsuwan W, Sin C, Keo S, Sangkanu S, de Lourdes Pereira M, Jimoh TO, et al.

Heliyon, 2021 May;7(5):e06976.
PMID: 34027178 DOI: 10.1016/j.heliyon.2021.e06976

Plants with medicinal properties have been used in the treatment of several infectious diseases, including Acanthamoeba infections. The medicinal properties of Cambodian plant extracts; Annona muricata and Combretum trifoliatum were investigated against Acanthamoeba triangularis. A total of 39 plant extracts were evaluated and, as a result, 22 extracts showed positive anti-Acanthamoeba activity. Of the 22 extracts, 9 and 4 extracts showed anti-Acanthamoeba activity against trophozoites and cysts of A. triangularis, respectively. The minimum inhibitory concentration of A. muricata and C. trifoliatum extracts against trophozoites and cysts was 500 and 1,000 μg/mL, respectively. The combination of A. muricata at 1/4×MIC with chlorhexidine at 1/8×MIC demonstrated a synergistic effect against trophozoites, but partial synergy against cysts. A 40% reduction in trophozoites and 60% of cysts adhered to the plastic surface treated with both extracts at 1/2×MIC were noted comparing to the control (P < 0.05). Furthermore, a reduction of 80% and 90% of trophozoites adhered to the surface was observed after pre-treatment with A. muricata and C. trifoliatum extracts, respectively. A 90% of cysts adhered to the surface was decreased with pre-treatment of A. muricata at 1/2×MIC (P < 0.05). A 75% of trophozoites and cysts from Acanthamoeba adhered to the surface were removed after treatment with both extracts at 4×MIC (P < 0.05). In the model of contact lens, 1 log cells/mL of trophozoites and cysts was significantly decreased post-treatment with both extracts compared to the control. Trophozoites showed strong loss of acanthopodia and thorn-like projection pseudopodia, while cysts demonstrated retraction and folded appearance treated with both extracts when observed by SEM, which suggests the potential benefits of the medicinal plants A. muricata and C. trifoliatum as an option treatment against Acanthamoeba infections.

Matched MeSH terms: Pseudopodia
Standardized Polyalthia longifolia leaf extract (PLME) inhibits cell proliferation and promotes apoptosis: The anti-cancer study with various microscopy methods

Vijayarathna S, Chen Y, Kanwar JR, Sasidharan S

Biomed Pharmacother, 2017 Jul;91:366-377.
PMID: 28463800 DOI: 10.1016/j.biopha.2017.04.112

Over the years a number of microscopy methods have been developed to assess the changes in cells. Some non-invasive techniques such as holographic digital microscopy (HDM), which although does not destroy the cells, but helps to monitor the events that leads to initiation of apoptotic cell death. In this study, the apoptogenic property and the cytotoxic effect of P. longifolia leaf methanolic extract (PLME) against the human cervical carcinoma cells (HeLa) was studied using light microscope (LM), holographic digital microscopy (HDM), scanning electron microscope (SEM) and transmission electron microscope (TEM). The average IC50 value of PLME against HeLa cells obtained by MTT and CyQuant assay was 22.00μg/mL at 24h. However, noncancerous Vero cells tested with PLME exhibited no cytotoxicity with the IC50 value of 51.07μg/mL at 24h by using MTT assay. Cytological observations showed nuclear condensation, cell shrinkage, multinucleation, abnormalities of mitochondrial cristae, membrane blebbing, disappearance of microvilli and filopodia, narrowing of lamellipodia, holes, formation of numerous smaller vacuoles, cytoplasmic extrusions and formation of apoptotic bodies as confirmed collectively by HDM, LM, SEM and TEM. In conclusion, PLME was able to produce distinctive morphological features of HeLa cell death that corresponds to apoptosis.

Matched MeSH terms: Pseudopodia
Live-cell imaging and ultrastructural analysis reveal remarkable features of cultured porcine gonocytes

Awang-Junaidi AH, Fayaz MA, Kawamura E, Sobchishin L, MacPhee DJ, Honaramooz A

Cell Tissue Res, 2020 Aug;381(2):361-377.
PMID: 32388763 DOI: 10.1007/s00441-020-03218-5

Gonocytes in the neonatal testis have male germline stem cell potential. The objective of the present study was to examine the behavior and ultrastructure of gonocytes in culture. Neonatal porcine testis cells were cultured for 4 weeks and underwent live-cell imaging to explore real-time interactions among cultured cells. This included imaging every 1 h from day 0 to day 3, every 2 h from day 4 to day 7, and every 1 h for 24 h at days 14, 21, and 28. Samples also underwent scanning electron microscopy, transmission electron microscopy, morphometric evaluations, immunofluorescence, and RT-PCR. Live-cell imaging revealed an active amoeboid-like movement of gonocytes, assisted by the formation of extensive cytoplasmic projections, which, using scanning electron microscopy, were categorized into spike-like filopodia, leaf-like lamellipodia, membrane ruffles, and cytoplasmic blebs. In the first week of culture, gonocytes formed loose attachments on top of a somatic cell monolayer and, in week 2, formed grape-like clusters, which, over time, grew in cell number. Starting at week 3 of culture, some of the gonocyte clusters transformed into large multinucleated embryoid body-like colonies (EBLCs) that expressed both gonocyte- and pluripotent-specific markers. The number and diameter of individual gonocytes, the number and density of organelles within gonocytes, as well as the number and diameter of the EBLCs increased over time (P

Matched MeSH terms: Pseudopodia