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PubMed1995

Gravity effect on lymphocyte deformation through cell shape change.

The effects on human cells (lymphocyte) immersed in a culture liquid under microgravity environment has been investigated. The study was based on the numerical simulation of the Morphology of human cells affected by the time dependent variation of gravity acceleration ranging from 10(-3) to 2 g(o) (g(o) = 9.81 m/s2) in 15 s. Both the free floating cells and the cells which came into contact with the upper and lower inclined walls imposed by the time-dependent reduced gravity acceleration were considered in this study. The results show that, when the gravity acceleration increased, the cell morphology changed from spherical to horizontally elongated ellipsoid for both the free floating cells and the stationary cells on the lower inclined wall while the cell morphology varied from spherical to vertically-elongated ellipsoid for the cells hanging on the upper inclined wall. A test of the deformation of human cells exposed to the variation of gravity levels, carried out in the KC-135 free fall aircraft, show that the results of experimental observations agree exactly with the theoretical model computation described in this paper. These results will be useful for study of the behavior and morphology of cells in space.

Cell Size↗
PubMed1986

Red cell rheology in stomatocyte-echinocyte transformation: roles of cell geometry and cell shape.

The influence of the shape of the red blood cell during stomatocyte-echinocyte transformation on its deformability was studied by microsieving through pores with diameters of 2.6, 4.5, and 6.9 micron. A stomatocytic transformation was produced by chlorpromazine (0.02, 0.1, and 0.5 mmol/L) and an echinocytic transformation by sodium salicylate (7.5, 30, and 120 mmol/L). For spherostomatocytes, an increase in filtration resistance through 2.6 and 4.5 micron pores was observed, whereas for spheroechinocytes, a decrease in filtration resistance through 2.6 micron pores was found. Larger pores (6.9 micron) were not sensitive to those shape changes. The changes in deformability can be explained by the fact that the surface area of (sphero)-stomatocytes decreased, whereas that of (sphero)-echinocytes increased; the cell volume remained essentially constant. Echinocytes produced by 24-hour adenosine triphosphate depletion differed from drug-induced echinocytes: they had an increased cell volume at constant surface area and consequently an increased filtration resistance through 2.6- and 4.5-micron filter pores. Shape changes with spicule formation are therefore not a homogeneous entity, and cell geometric factors (eg, surface area and volume) must be assessed with care. The viscosity of red cell suspensions at a hematocrit level of 45% was higher for drug-induced echinocytes than discocytes or stomatocytes at all shear rates tested. We conclude that the normal discocyte represents an optimum shape for the flow in vivo since a stomatocytic transformation could impair the passage through the microcirculation (decrease in cell filterability) and an echinocytic transformation could impair the flow in larger vessels (increase in blood viscosity).

Acanthocytes↗
PubMed1996

Effects of ligation, orchidectomy, and hypophysectomy on expression of the Yf subunit of GST-P in principal and basal cells of the adult rat epididymis and on basal cell shape and overall arrangement.

BACKGROUND: Glutathione S-transferases (GSTs) are a family of isozymes that catalyze the conjugation of glutathione to various electrophilic compounds. Recently, the Yf subunit of GST-P, found in high concentrations in the epididymis, has been immunolocalized within epithelial principal and basal cells of this tissue. In order to determine which factor(s) were involved in the regulation of expression of this protein, adult rats were orchidectomized and treated with or without testosterone implants, ligated or hypophysectomized. METHODS: The epididymides were fixed by perfusion with Bouin's fixative and examined with an anti-Yf antibody using light microscope immunocytochemistry. RESULTS: In normal untreated animals, principal cells were reactive in the distal initial segment, intermediate zone and caput epididymidis, but unreactive in all other epididymal regions. Ligation of the efferent ducts up to day 14 had no effect on expression of the Yf protein in principal cells of any region. The staining pattern was comparable to that observed in normal untreated animals suggesting that luminally derived testicular factors were not involved in regulation of Yf expression. Following orchidectomy, principal cells became unreactive by day 14 in all epididymal regions. However, administration of testosterone to orchidectomized animals prevented the loss of reactivity seen in principal cells of the distal initial segment, intermediate zone, and caput epididymidis, suggesting that expression of the Yf protein in principal cells of these regions is regulated by circulating testosterone. In contrast, basal cells after each experimental treatment including hypophysectomy maintained the exact staining pattern observed in normal untreated animals, i.e., they were intensely reactive in the proximal initial segment, distal caput, corpus, and proximal cauda regions, suggesting that expression of the Yf protein in these cells does not require factors derived from the testis or pituitary gland. However, a change in the shape and arrangement of basal cells was noted following each treatment. These cells transformed from flattened hemispherical cells showing thin elongated lateral processes to large bulbous, dome-shape cells closely packed together and showing only a few short lateral processes. CONCLUSIONS: In basal cells, expression of the Yf protein is not regulated by testicular or pituitary factors, whereas expression in principal cells is regulated by circulating testosterone. Due to the decrease in size of the epididymal tubules after each treatment, it is postulated that the shape and arrangement of basal cells in normal untreated animals are governed in part by the volume and pressure exerted upon the tubules by luminal fluids and spermatozoa derived from the testis.

Animals↗
PubMed1991

The response of endothelial cells to TGF beta-1 is dependent upon cell shape, proliferative state and the nature of the substratum.

Endothelial cells plated on two-dimensional (2-D) substrata proliferate until they form a tightly apposed confluent monolayer of quiescent cells that display a typical 'cobblestone' morphology. When added to proliferating cultures TGF beta-1 (transforming growth factor beta-1) inhibited cell growth and caused marked morphological changes, with the cells becoming enlarged and ragged. These effects were dose-dependent and reversible. TGF beta-1 also reduced the cloning efficiency and colony size of these cells, indicating that TGF beta-1 is cytotoxic and cytostatic for endothelial cells. By contrast, TGF beta-1 added to quiescent cobblestone cultures did not affect cell morphology or cell numbers. In the presence of 20% serum, the level of total protein synthesis per cell was significantly increased by TGF beta-1 in a dose-dependent manner when the cells were cultured on a 2-D substratum, regardless of whether the cells were proliferating or cobblestone quiescent. The level of plasminogen activator inhibitor type 1 was specifically increased in these cultures, as demonstrated by reverse fibrin zymography and immunoprecipitation. Endothelial cells embedded within a 3-D collagen gel display an elongated 'sprouting' morphology. Such cells self-associate to form three-dimensional cellular networks within the gel, but do not proliferate. The addition of TGF beta-1 to these quiescent sprouting cells initially induced rounding-up without altering protein synthesis, and cell death occurred later. The effects of TGF beta-1 on sprouting endothelial cells were also examined using two culture systems where both the cobblestone and the sprouting phenotypes were present. TGF beta-1 reduced the number of cells present and the extent of migration of sprouting cells embedded within a type I collagen gel, but had no effect upon sprouting cells embedded within a complex endothelial-produced extracellular matrix. Large vessel (aortic) and microvessel (retinal) endothelial cells responded in a similar way to TGF beta-1; the only difference being that an increased synthesis of PAI-1 was not observed with sub-confluent BREC cultures. Our results suggest that the effects of TGF beta-1 upon endothelial cells depend on the shape (cobblestone or sprouting), on the proliferative state of the cells, and on the nature of the matrix surrounding the cells. The response of these cells to TGF beta-1 in vivo may be similarly modulated during angiogenesis by changes in the cell phenotype and the composition of the surrounding matrix.

Animals↗
PubMed1998

Cell shape changes and cytoskeleton reorganization during transendothelial migration of human melanoma cells.

An in vitro system has been established to study the migration of human melanoma cells through a monolayer of endothelial cells. Endothelial cells were cultured to confluence on Matrigel before the seeding of melanoma cells. Laser scanning confocal microscopy showed that, prior to migration, melanoma cells appeared round and showed cortical F-actin staining. The initial stage of transmigration was characterized by numerous membrane blebs protruding from basolateral surfaces of the melanoma cells, and contact regions showed an abundance of filaments arising in the underlying endothelial cells. Later, pseudopods from the melanoma cells inserted into contact regions between endothelial cells. Eventually, the melanoma cells intercalated with the endothelial cells. At this stage, many endothelial filament bundles terminated at contacts between the endothelial cells and the transmigrating melanoma cell, suggesting active interactions between the two cell types. Upon contact with the Matrigel, melanoma cells began to spread beneath the endothelium, displaying a fibroblastic morphology with prominent stress fibers. To reestablish the monolayer, adjacent endothelial cells extended processes over the melanoma cell. Tumor necrosis factor alpha did not affect the transmigration of melanoma cells from cell lines isolated from several stages of metastasis. However, tumor necrosis factor did promote the transmigration of melanoma cells derived from a non-metastatic lesion. These results thus define cell attachment and cell penetration of the monolayer as two distinct steps in transmigration and suggest that tumor necrosis factor may enhance the metastatic potential of tumor cells.

Actins↗
PubMed1990

Single cell shape and population densities of indoleamine-accumulating and displaced bipolar cells in Reeves' turtle retina.

Two types of bipolar cell in the Geoclemys reevesii retina were studied quantitatively by means of specific cell labelling with an indoleamine derivative (5,6-dihydroxytryptamine, 5,6-DHT), a nucleic acid stain (4,6-diamidino-2-phenylindole, DAPI) and Lucifer yellow CH. Indoleamine-accumulating (IA) bipolar cells were selectively labelled with 5,6-DHT applied intraocularly. After the cells accumulated 5,6-DHT, the indoleamine fluorescence was photoconverted to diaminobenzidine products to allow observation of morphological details. Close examination of many cells (cell number; n = 120) showed that the IA bipolar cells consist of a single morphological type whose axon collaterals ramify sublaminae 1, 4 and 5 respectively. This terminal branching pattern corresponds to cells that hyperpolarize when their receptive field centres are illuminated (Weiler 1981). The density of IA bipolar cells was highest in the visual streak (4130 cells mm-2) and lowest at the peripheral margin (1970 cells mm-2). By applying a small amount of DAPI to the eye, nuclei located in the most proximal row of the outer nuclear layer were labelled selectively. By using selective intracellular dye injection into DAPI-labelled cells under fluorescence microscope (Tauchi & Masland 1984, 1985), these cells were found to have Landolt's clubs and single descending axons. Dye injections into more than fifty DAPI-labelled somata showed that they belonged exclusively to displaced bipolar cells. These comprised at least two subtypes that differ in the ramification pattern of their axon terminals within the inner plexiform layer: one was monostratified, whereas the other was bistratified. The displaced bipolar cell density was as high as 9400 cells mm-2 in the central retina, falling to 2000 cells mm-2 in the superior margin. In vitro Lucifer labelling revealed that the overall bipolar cell density in the central retina was as high as 39,300 cells mm-2. Both the conventionally located and displaced bipolar cells were included in this population. About 11% of the total bipolar cell population consisted of IA bipolar cells. Assuming that one half of the conventionally located bipolar cells are the centre-hyperpolarizing type, IA bipolar cells represent approximately 28% of the total. As displaced bipolar cells represent almost one quarter of the total bipolar population, the dislocation of their somata stands out morphologically, inviting investigation of possible functional correlates.

5,6-Dihydroxytryptamine↗
PubMed2003

Heterospecific expression of the Bacillus subtilis cell shape determination genes mreBCD in Escherichia coli.

The divIVB operon of Bacillus subtilis includes the cell shape-associated mre genes, including the membrane-associated proteins MreC and MreD. TnphoA mutagenesis was utilized to analyze a topological model for MreC. MreC has a short cytoplasmic amino terminus, a single membrane-spanning domain, and a large carboxy terminal domain which lies externally to the outer leaflet of the cell membrane. Expression of the B. subtilis MreB protein, or the Mre C and D proteins, results in a morphological conversion of the Escherichia coli host cells from a rod to a roughly spherical cell, morphologically similar to mre-negative mutants of E. coli. Immunolocalization of the MreC protein in B. subtilis revealed that this protein is found at the midcell division site of the bacterial cells, consistent with the postulated role of the Mre proteins in the regulation of septum-specific peptidoglycan synthesis.

Alkaline Phosphatase↗
PubMed2006

Subcellular topological effect of particle monolayers on cell shapes and functions.

We studied topological effects of subcellular roughness displayed by a closely packed particle monolayer on adhesion and growth of endothelial cells. Poly(styrene-co-acrylamide) (SA) particles were prepared by soap-free emulsion copolymerization. Particle monolayers were prepared by Langmuir-Blodgett deposition using particles, which were 527 (SA053) and 1270 nm (SA127) in diameter. After 24-h incubation, cells tightly adhered on a tissue culture polystyrene dish and randomly spread. On the other hand, cells attached on particle monolayers were stretched into a narrow stalk-like shape. Lamellipodia spread from the leading edge of cells attached on SA053 monolayer to the top of the particles and gradually gathered to form clusters. This shows that cell-cell adhesion became stronger than cell-substrate interaction. Cells attached to SA127 monolayer extended to the reverse side of a particle monolayer and engulfed particles. They remained immobile without migration 24h after incubation. This shows that the inhibition of extensions on SA127 monolayer could inhibit cell migration and cell proliferation. Cell growth on the particle monolayers was suppressed compared with a flat TCPS dish. The number of cells on SA053 gradually increased, whereas that on SA127 decreased with time. When the cell seeding density was increased to 200,000 cells cm(-2), some adherent cells gradually became into contact with adjacent cells. F-actin condensations were formed at the frame of adherent cells and the thin filaments grew from the edges to connect each other with time. For the cell culture on SA053 monolayer, elongated cells showed a little alignment. Cells showed not arrangement of actin stress fibers but F-actin condensation at the contact regions with neighboring cells. Interestingly, the formed cell monolayer could be readily peeled from the particle monolayer. These results indicate that endothelial cells could recognize the surface roughness displayed by particle monolayers and the response was dependent on the pitch of particle monolayers.

Actins↗
PubMed1977

Microfilament bundles and cell shape are related to adhesiveness to substratum and are dissociable from growth control in cultured fibroblasts.

The distribution of microfilament bundles in cells was examined using antibodies to fibroblast myosin and indirect immunofluorescence microscopy. There is no correlation between the presence of bundles of microfilaments and normal growth control. A normal cell line (Balb/c 3T3) cultured on a poorly adhesive substratum showed no microfilament bundles. Similarly, a mutant cell line (AD6) with normal growth, but a rounded shape due to defective adhesiveness to substratum, showed no bundle formation. On the other hand, two transformed cell lines with a flat morphology (Swiss SV3T3 and Balb MSV-85) showed extensive bundle formation. When a transformed cell line with poor adhesiveness (MC5-5) was treated with CSP (a major surface glycoprotein of normal cells) which increases adhesiveness to substratum, the cells formed extensive microfilament bundles without any decrease in growth. We conclude that the distribution of microfilament bundles is related to adhesiveness to substratum and cell shape but not to growth properties.

Acetylglucosamine↗
PubMed1987

A mutation affecting basal body duplication and cell shape in Paramecium.

The thermosensitive mutant sm19 of Paramecium tetraurelia undergoes a progressive reduction in cell length and basal body number over successive divisions at the nonpermissive temperature of 35 degrees C. In spite of these defects, sm19 cells retain the same generation time as wild-type cells at 35 degrees C. Cytological observations at both electron and light microscopy levels reveal no other perturbation than the rarefaction of basal bodies and the rare (3%) absence of one or two microtubules in basal bodies or ciliary axonemes. The temperature-sensitive period, during the last 30 min of the cell cycle, corresponds to the phase of basal body duplication. Upon transfer back to the permissive temperature, all basal bodies are normally duplicated. The mutational defect is transiently restored by microinjection of wild-type cytoplasm or of a soluble proteic fraction from wild-type cell homogenates. Altogether, the cytological and physiological data support the conclusion that the sm19+ gene codes for a diffusible product required for the initiation of basal body duplication and would thus be the first identified gene involved in this process. Our data also indicate that in Paramecium basal body number is not coupled with control of the cell cycle, but helps determine the shape of the cell via the organization of the cytoskeleton.

Animals↗
PubMed2003

Alterations of red blood cell shape and sialic acid membrane content in septic patients.

OBJECTIVE: To investigate the relationship between red blood cell (RBC) shape and modifications of RBC membrane protein content in critically ill patients with or without sepsis compared with healthy control volunteers. DESIGN: Prospective, observational in vitro study. SETTING: University-affiliated cell biology laboratory. SUBJECTS: Human erythrocytes from healthy volunteers and nonseptic and septic intensive care unit patients. INTERVENTIONS: Sialic acid membrane content was measured on isolated RBC membrane proteins by high-performance liquid chromatography. RBC shape, estimated by the spherical index (M2/M1) or by the moment and effect of osmolality on RBC shape, was studied by flow cytometry at 25 degrees C. Glycophorin A content was measured with antiglycophorin antibodies in flow cytometry. MEASUREMENTS AND MAIN RESULTS: Sialic acid content was lower in the septic than in the nonseptic patients (1.98 +/- 0.79, 2.20 +/- 0.39 microg/100 microg membrane protein, respectively; p =.01) and than in the volunteers (2.71 +/- 1.00 microg/100 microg membrane protein; p <.001). No significant difference was found in glycophorin A content between septic and nonseptic patients. RBCs from septic patients had a more spherical shape in isotonic solution than those of healthy volunteers, as assessed by a computed spherical index (M2/M1 ratio: 1.68 +/- 0.34 vs. 1.95 +/- 0.32; p =.001). Only the RBCs of septic patients failed to change their shape in hypo-osmolar solution (M2/M1 ratio: 1.68 +/- 0.34 in iso-osmolar, 1.56 +/- 0.28 in hypo-osmolar solution; p =.17). There was a significant correlation between the RBC shape evaluated by the spherical index or by the moment of the cytometric histogram and the sialic acid membrane content in all critically ill patients (septic and nonseptic patients) (r2 =.16, p =.01 for the moment, and r2 =.17, p =.01 for the spherical index, respectively). CONCLUSIONS: RBCs of septic patients are characterized by a more spherical shape, a decreased capacity of sphericity in hypo-osmolar solution, and a reduction in the sialic acid content of the RBC membrane. These modifications in RBC shape and membrane may contribute to the RBC rheologic abnormalities frequently described in sepsis.

Aged↗
PubMed1985

Effects of monovalent cations on red cell shape and size.

Human erythrocytes were incubated in isotonic solutions of different monovalent cations. The apparent size of the red cells measured on scanning electron microscopic pictures decreases in the order Li+ greater than Na+ = K+ greater than Rb+. These differences in size are abolished after pretreatment with trypsin, which removes a large part of the charges associated with membrane glycoproteins. Shape alterations are also observed. Normal biconcave shapes are visible after Na+ or K+ incubation, whereas Li+ leads to flabby, flattened cells with a certain tendency to crenation, and Rb+ causes more pronounced biconcavity with a certain tendency to cupping. The overall effects of pretreatment with trypsin are similar to those of Li+. Our results provide evidence that the electrostatic repulsion of glycoproteins and other charged membrane components may play an essential role in maintaining red cell shape.

Cations, Monovalent↗
PubMed1997

The predominant defect in dilute melanocytes is in melanosome distribution and not cell shape, supporting a role for myosin V in melanosome transport.

Mice with mutations at the dilute locus, which encodes the heavy chain of a type V unconventional myosin, exhibit a reduction in coat colour intensity. This defect is thought to be caused by the absence in dilute melanocytes of the extensive dendritic arbor through which these cells normally deliver pigment-laden melanosomes to keratinocytes. The data on which this conclusion has been based can also be explained, however, by a defect in the outward transport of melanosomes within melanocytes of normal shape. To resolve this question, we compared the shape and pigment distribution within melanocytes present in primary cultures prepared from the epidermis of C57BL/6J pups that were either wild type (D/D) at dilute or homozygous for the dilute null allele d120J. These same comparisons were also performed on melanocytes in situ, where antibodies to the membrane tyrosine kinase receptor cKIT were used to visualize melanocyte cell shape independent of pigment distribution. Wild type melanocytes were found to be dendritic and to have melanosomes distributed throughout their dendrites both in vitro and in situ. Mutant melanocytes were also found to be dendritic in both cases, but their melanosomes were highly concentrated in the cell body and largely excluded from dendrites. We conclude, therefore, that the predominant defect in dilute melanocytes is in melanosome distribution, not cell shape. These results argue that the myosin V isoform encoded by the dilute locus functions in dendritic extensions to move melanosomes from their site of formation within the cell body to their site of intercellular transfer at dendritic tips. This conclusion is consistent with our recent demonstration by immunolocalization that the dilute myosin V isoform associates with melanosomes in mouse melanocytes.

Animals↗
PubMed1982

Cell shape and organization of cytoskeleton and surface fibronectin in non-tumorigenic and tumorigenic rat liver cultures.

Morphological changes associated with neoplastic transformation of epithelial cells were studied in a series of IAR cell lines derived from rat liver. The series included three independently obtained, non-tumorigenic lines and five derived, tumorigenic lines. The morphology of cell surfaces was observed by scanning electron microscopy; the distribution of actin, tubulin and fibronectin was determined by indirect immunofluorescence. All the non-tumorigenic lines had a typical epithelioid morphology: isolated cells of these lines spread on the substratum had a discoid shape and contained circular, marginal bundles of microfilaments and microtubules. In denser areas, the cells formed monolayered sheets with characteristic marginal bundles of microfilaments near the free edges. Decreased spreading of isolated cells on the substratum was the characteristic feature that distinguished tumorigenic lines from their non-tumorigenic parent lines. In particular a decrease in the size of the ring-like, peripheral lamella and its disintegration into several discrete lamellar zones were often observed; as a result, the cell shape was altered from discoid to polygonal or elongated. The altered distribution of microfilament bundles and microtubules was characteristic in elongated cells; the pattern of the cytoskeletal elements of these cells resembled that of polarized fibroblasts. Complete disappearance of microfilament bundles was observed in cells of only one tumorigenic line. Various degrees of disorganization of monolayered cell sheets were observed in tumorigenic cultures, accompanied by an altered distribution of microfilament bundles. The alterations in the fibronectin-containing structures were more complex: there were often fewer fibronectin "spots' and fibrils at the lower surfaces of cells of tumorigenic cultures as compared with those of non-tumorigenic ones; there were more fibrils in dense cultures of certain lines but fewer in others. It is concluded that alterations in the ability to spread on the substratum and to form cell-cell contacts are common features of morphologically transformed fibroblastic and epithelial cultures. However, the actual changes in the cytoskeletal structures that accompany these alterations are different in transformed cultures of various tissue types.

Animals↗
PubMed1989

A morphology index for characterization of cell shape in Candida albicans.

The morphology of Candida albicans cells was determined from their maximum length, maximum diameter and septal diameter in a mathematical ratio, the morphology index (Mi), which usually ranged from approximately 1 for spherical yeast cells to approximately 4 for true hyphae, with elongated yeast cells and pseudohyphae giving intermediate values. Mi could be determined with high reproducibility for C. albicans grown in a variety of environments. The highest mean Mi was seen with cells grown in serum and Eagle's medium at 37 degrees C, the lowest with cells grown in Sabouraud glucose broth at 26 degrees C. Variant strains of C. albicans gave Mi values that remained constant in a variety of growth environments. The Mi facilitated detection of two variants that grew exclusively in the yeast form, one that grew as elongated yeasts but could be induced to form pseudohyphae in serum, and one consistently pseudohyphal variant. Cells with a mean Mi up to 2.5 could be easily separated at septal junctions by mild ultrasonication, whereas cells with a mean Mi greater than 3.5 tended not to separate under these conditions. The chitin content of C. albicans cells was almost twice as great in cells with a Mi approaching 4 as in cells with a Mi close to 1. The wide range of Mi distributions for a single C. albicans isolate in different environments demonstrates that the fungus does not undergo abrupt changes of morphological phase: rather there are continual changes in morphology between spherical yeasts and true hyphae at the extremes. The study shows that Mi can be used reliably in place of subjective descriptions of morphology to indicate the shape of a C. albicans cell. It should facilitate the detection of molecular and cellular markers specific for morphogenesis in the fungus.

Candida albicans↗
PubMed1995

Effects of hypergravity on the cell shape and on the organization of cytoskeleton and extracelluar matrix molecules of in vitro human dermal fibroblasts.

In vitro human dermal fibroblasts were submitted to normal gravity (1 g) or to chronic hypergravity ranging from 2 to 20 g for 8 days. Changes only appeared above 15 g. The majority of 20 g-subjected cells showed fine filipods in the shape of a star whereas most control cells had rounded shapes and spread by forming lamellipodia. Indirect immunofluorescence staining of vinculin, alpha-actinin and actin stress fibers showed changes of the arrangement anchoring points of stress fibers under hypergravity. Tubulin staining showed that the centrosomal material generally located above the nucleus in control cells had migrated to the nucleus side in 20 g-exposed cells. After 8 d of culture under 20 g hypergravity the thickness of fibronectin network seemed to be increased and bundles of fibrils appeared linking ordered arrays of fibers. The fibrils of collagen I formed better delimited and thicker bundles of fibers. We may assume that 20 g hypergravity can induce changes in fibroblast cell shape, migration way, and anchorage leading to a reorganization of extracellular matrix without concomitant change of cell proliferation.

Actin Cytoskeleton↗