scholarly journals Vibrio cholerae biofilm dispersal regulator causes cell release from matrix through type IV pilus retraction

2021 ◽  
Author(s):  
Praveen K. Singh ◽  
Daniel K.H. Rode ◽  
Pauline Buffard ◽  
Kazuki Nosho ◽  
Miriam Bayer ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Vibrio Cholerae ◽  
Joint Effect ◽  
Bacterial Biofilm ◽  
Matrix Composition ◽  
Type Iv Pilus ◽  
Type Iv ◽  
The Matrix ◽  
Cell Release ◽  
Biofilm Dispersal

The extracellular matrix is a defining feature of bacterial biofilms and provides structural stability to the community by binding cells to the surface and to each other. Transitions between bacterial biofilm initiation, growth, and dispersion require different regulatory programs, all of which result in modifications to the extracellular matrix composition, abundance, or functionality. However, the mechanisms by which individual cells in biofilms disengage from the matrix to enable their departure during biofilm dispersal are unclear. Here, we investigated active biofilm dispersal of Vibrio cholerae during nutrient starvation, resulting in the discovery of the conserved Vibrio biofilm dispersal regulator VbdR. We show that VbdR triggers biofilm dispersal by controlling cellular release from the biofilm matrix, which is achieved by inducing the retraction of the mannose-sensitive hemagglutinin (MSHA) type IV pili and the expression of a matrix protease IvaP. We further show that MSHA pili have numerous binding partners in the matrix and that the joint effect of MSHA pilus retraction and IvaP activity is necessary and sufficient for causing biofilm dispersal. These results highlight the crucial role of type IV pilus dynamics during biofilm dispersal and provide a new target for controlling V. cholerae biofilm abundance through the induction and manipulation of biofilm dispersal.

scholarly journals CryoEM Structure of the Vibrio cholerae Type IV Pilus Secretin PilQ

2020 ◽  
Vol 118 (3) ◽  
pp. 12a
Author(s):  
Sara J. Weaver ◽  
Matthew Sazinsky ◽  
Triana Dalia ◽  
Ankur Dalia ◽  
Grant J. Jensen
Keyword(s):  
Vibrio Cholerae ◽  
Type Iv Pilus ◽  
Type Iv

STUDYING THE INTERNAL STRESS HETEROGENEITY OF THE GROWING BIOFILM BY THE MICROPILLAR DEFORMATION OF THE GROWING SUBSTRATE

2019 ◽  
Vol 19 (06) ◽  
pp. 1950070
Author(s):  
XIAOLING WANG ◽  
ZHAOCAN WANG ◽  
XING SHEN ◽  
YUHAO KONG ◽  
HUI ZHAO ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Internal Stress ◽  
Early Time ◽  
Bacterial Biofilm ◽  
Internal Stresses ◽  
Mechanical Resistance ◽  
Self Healing ◽  
Biofilm Thickness ◽  
The Matrix ◽  
Stress Heterogeneity

The bacterial biofilm is a microbial community in which bacteria are embedded in the extracellular matrix and can also be used as a solid composite. It was found that internal stresses are generated during pellicle growth, which exists between the air and the liquid. But we do not know if there is the internal stress in the biofilm, which exists between the air and the solid, and how does the internal stress evolve and distribute in the growing biofilm. So, in this paper, we make the growing substrate into the micropillar array to grow biofilms, each micropillar has the deformation due to the growing heterogeneity of the biofilm around the micropillar, and we can get the internal stress by measuring each micropillar’s deformation. First, we find that the direction of the internal stress is approximately along the biofilm expansion at the early time, colonies are formed in the biofilm at the later time, which cause the internal stress locally along the expansion of the colony. Second, the internal stress is proportional to the biofilm thickness. Finally, we find that the matrix producing cells contribute more the internal stress, and the internal stress evolving is closely related to the secretion of the extracellular matrix. Form our work, we obtain the distribution of the internal stress direction, we also can use the biofilm thickness, which is easy to measure, express the internal stress approximately, by doing so, we can further study other phenomena of biofilms, such as self-healing and mechanical resistance.

Metalloproteinases mediate extracellular matrix degradation by cells from mouse blastocyst outgrowths

Development ◽  
1992 ◽  
Vol 114 (2) ◽  
pp. 447-456 ◽  
Author(s):  
O. Behrendtsen ◽  
C.M. Alexander ◽  
Z. Werb
Keyword(s):  
Extracellular Matrix ◽  
Giant Cells ◽  
Matrix Degradation ◽  
Trophoblast Cells ◽  
Type Iv Collagenase ◽  
Type Iv ◽  
The Matrix ◽  
Remodeling Of Extracellular Matrix ◽  
Trophoblast Giant Cells ◽  
Blocking Antibodies

The maintenance and developmental remodeling of extracellular matrix is crucial to such processes as uterine implantation and the cell migratory events of morphogenesis. When mouse blastocysts are placed in culture they adhere to extracellular matrix, and trophoblast giant cells migrate out onto the matrix and degrade it. The secretion of functional proteinases by developing mouse embryos increases dramatically at the time of implantation. By zymography we identified the major secreted gelatin-degrading proteinase, also known as type IV collagenase, as one migrating at 92 × 10(3) Mr. Several casein-degrading proteinases were also secreted. The tissue inhibitor of metalloproteinases (TIMP) inhibited all of the embryo-derived proteinases detected by gelatin gel zymography, indicating that they are metalloproteinases, whereas TIMP did not inhibit all of the caseinases. Urokinase was also secreted. Addition of TIMP at 5–500 nM effectively inhibited the degradation of matrix by the trophoblast outgrowths. Blocking antibodies directed against 92 × 10(3) Mr gelatinase abolished matrix degradation by the trophoblast cells. These observations suggest that several metalloproteinases are regulated in early development and that 92 × 10(3) Mr gelatinase, in particular, has a rate-limiting function in degradation of the maternal extracellular matrix by trophoblast cells.

scholarly journals Schwann cells use a novel collagen-dependent mechanism for fibronectin fibril assembly

1998 ◽  
Vol 111 (18) ◽  
pp. 2763-2777 ◽  
Author(s):  
M.A. Chernousov ◽  
R.C. Stahl ◽  
D.J. Carey
Keyword(s):  
Extracellular Matrix ◽  
Schwann Cells ◽  
Collagen Type ◽  
Collagen Type I ◽  
Collagen Type Iv ◽  
Type I ◽  
Type Iv ◽  
The Matrix ◽  
Fibronectin Fibrils ◽  
Dependent Mechanism

Cultured rat Schwann cells were stimulated to deposit fibrillar extracellular matrix by treatment with ascorbic acid in the absence of nerve cells. Immunofluoresence staining of the matrix showed that it contains collagens types I and IV, fibronectin and perlecan but not laminin. Collagen type IV, fibronectin and perlecan co-distributed completely in the matrix fibrils, whereas collagen type I was present in only a subset of these fibrils. Time course studies indicated that collagen type I fibrils appear at late stages of matrix formation. Digestion of Schwann cell extracellular matrix with collagenase effectively disrupted most of the matrix including fibronectin fibrils. This was in contrast with fibroblasts, where collagenase treatment removed collagen with no visible effect on fibronectin fibrils. alpha5 integrin was expressed on the cell surface of Schwann cells and partially codistributed with fibronectin-containing fibrils. This suggests that the inability of Schwann cells to deposit fibronectin-containing matrix through a conventional, collagen-independent mechanism was not due to the lack of fibronectin-binding integrins on their cell surface. Polyclonal anti-fibronectin antibodies inhibited the deposition of fibronectin into the matrix fibrils, whereas collagen type IV fibrils were generally unaffected. Growth of Schwann cells on collagen type IV-coated substrate in the absence of ascorbate induced deposition of fine fibronectin fibrils. These results suggest that Schwann cells use an apparently novel, collagen type IV-dependent mechanism for the deposition of fibronectin into their extracellular matrix.

scholarly journals Extracellular matrix density regulates the formation of tumour spheroids through cell migration

2021 ◽  
Vol 17 (2) ◽  
pp. e1008764
Author(s):  
Inês G. Gonçalves ◽  
Jose Manuel Garcia-Aznar
Keyword(s):  
Mechanical Properties ◽  
Extracellular Matrix ◽  
Cell Migration ◽  
Tumour Growth ◽  
Individual Cell ◽  
Matrix Composition ◽  
Matrix Density ◽  
Tumour Spheroids ◽  
The Matrix ◽  
Collagen Density

In this work, we show how the mechanical properties of the cellular microenvironment modulate the growth of tumour spheroids. Based on the composition of the extracellular matrix, its stiffness and architecture can significantly vary, subsequently influencing cell movement and tumour growth. However, it is still unclear exactly how both of these processes are regulated by the matrix composition. Here, we present a centre-based computational model that describes how collagen density, which modulates the steric hindrance properties of the matrix, governs individual cell migration and, consequently, leads to the formation of multicellular clusters of varying size. The model was calibrated using previously published experimental data, replicating a set of experiments in which cells were seeded in collagen matrices of different collagen densities, hence producing distinct mechanical properties. At an initial stage, we tracked individual cell trajectories and speeds. Subsequently, the formation of multicellular clusters was also analysed by quantifying their size. Overall, the results showed that our model could accurately replicate what was previously seen experimentally. Specifically, we showed that cells seeded in matrices with low collagen density tended to migrate more. Accordingly, cells strayed away from their original cluster and thus promoted the formation of small structures. In contrast, we also showed that high collagen densities hindered cell migration and produced multicellular clusters with increased volume. In conclusion, this model not only establishes a relation between matrix density and individual cell migration but also showcases how migration, or its inhibition, modulates tumour growth.

scholarly journals The Orphan Response Regulator DigR Is Required for Synthesis of Extracellular Matrix Fibrils in Myxococcus xanthus

2006 ◽  
Vol 188 (12) ◽  
pp. 4384-4394 ◽  
Author(s):  
Martin Overgaard ◽  
Sigrun Wegener-Feldbrügge ◽  
Lotte Søgaard-Andersen
Keyword(s):  
Extracellular Matrix ◽  
Response Regulator ◽  
Cell Envelope ◽  
Transcriptional Profiling ◽  
Myxococcus Xanthus ◽  
Gliding Motility ◽  
Differentially Expressed ◽  
Type Iv Pilus ◽  
Receiver Domain ◽  
Type Iv

ABSTRACT In Myxococcus xanthus, two-component systems have crucial roles in regulating motility behavior and development. Here we describe an orphan response regulator, consisting of an N-terminal receiver domain and a C-terminal DNA binding domain, which is required for A and type IV pilus-dependent gliding motility. Genetic evidence suggests that phosphorylation of the conserved, phosphorylatable aspartate residue in the receiver domain is required for DigR activity. Consistent with the defect in type IV pilus-dependent motility, a digR mutant is slightly reduced in type IV pilus biosynthesis, and the composition of the extracellular matrix fibrils is abnormal, with an increased content of polysaccharides and decreased accumulation of the FibA metalloprotease. By using genome-wide transcriptional profiling, 118 genes were identified that are directly or indirectly regulated by DigR. These 118 genes include only 2, agmQ and cheY4, previously implicated in A and type IV pilus-dependent motility, respectively. In silico analyses showed that 36% of the differentially expressed genes are likely to encode exported proteins. Moreover, four genes encoding homologs of extracytoplasmic function (ECF) sigma factors, which typically control aspects of cell envelope homeostasis, are differentially expressed in a digR mutant. We suggest that the DigR response regulator has an important function in cell envelope homeostasis and that the motility defects in a digR mutant are instigated by the abnormal cell envelope and abnormal expression of agmQ and cheY4.

scholarly journals The 1.9 Å crystal structure of the extracellular matrix protein Bap1 from Vibrio cholerae provides insights into bacterial biofilm adhesion

2019 ◽  
Vol 294 (40) ◽  
pp. 14499-14511 ◽  
Author(s):  
Katherine Kaus ◽  
Alison Biester ◽  
Ethan Chupp ◽  
Jianyi Lu ◽  
Charlie Visudharomn ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Extracellular Matrix ◽  
Vibrio Cholerae ◽  
Matrix Protein ◽  
Bacterial Biofilm ◽  
Extracellular Matrix Protein

scholarly journals Molecular analysis of VcfQ protein involved in Vibrio cholerae type IV pilus biogenesis

2003 ◽  
Vol 52 (4) ◽  
pp. 283-288 ◽  
Author(s):  
Tomoko Miyazato ◽  
Claudia Toma ◽  
Noboru Nakasone ◽  
Koichiro Yamamoto ◽  
Masaaki Iwanaga
Keyword(s):  
Vibrio Cholerae ◽  
Gene Cluster ◽  
Mutational Analysis ◽  
Cell Fractionation ◽  
Deficient Mutant ◽  
Type Iv Pilus ◽  
Outer Membranes ◽  
Type Iv ◽  
Pilus Biogenesis ◽  
Immunological Cross Reaction

The nucleotide sequence of an ORF (vcfQ) within the type IV pilus gene cluster of Vibrio cholerae O34 strain NAGV14 was determined, thereby completing the sequence analysis of the structural operon. The vcfQ gene showed homology to the mshQ gene of the mannose-sensitive haemagglutinin pilus gene cluster. The vcfQ was 651 bp larger than mshQ, and the G+C content of the extra 651 bp portion (35.6 mol%) was lower than that of the overall vcfQ gene (42.5 mol%). Except for the first 270 aa residues, the deduced amino acid sequence of VcfQ showed high homology to the MshQ protein. There was immunological cross-reaction between VcfQ and MshQ by Western blotting. Cell fractionation studies showed that VcfQ is located in both the inner and the outer membranes. Mutational analysis showed that vcfQ-deficient mutant expressed detectable levels of major pilin (VcfA), but failed to assemble them into pili, indicating that VcfQ is essential for pilus assembly. Colony-blotting analyses showed that the N-terminal region of vcfQ is variable in V. cholerae strains.

Effects of EDTA, Hyaluronidase and Collagenase on Epiphyseal Cartilage Matrix

1968 ◽  
Vol 26 ◽  
pp. 56-57
Author(s):  
H. Clarke Anderson ◽  
Priscilla R. Coulter
Keyword(s):  
Light And Electron Microscopy ◽  
Matrix Vesicles ◽  
Cartilage Matrix ◽  
Collagen Fibrils ◽  
Epiphyseal Cartilage ◽  
Dense Matrix ◽  
Type Iv ◽  
Bovine Testicular Hyaluronidase ◽  
The Matrix ◽  
Testicular Hyaluronidase

Epiphyseal cartilage matrix contains fibrils and particles of at least 5 different types: 1. Banded collagen fibrils, present throughout the matrix, but not seen in the lacunae. 2. Non-periodic fine fibrils <100Å in diameter (Fig. 1), which are most notable in the lacunae, and may represent immature collagen. 3. Electron dense matrix granules (Fig. 1) which are often attached to fine fibrils and collagen fibrils, and probably contain protein-polysaccharide although the possibility of a mineral content has not been excluded. 4. Matrix vesicles (Fig. 2) which show a selective distribution throughout the epiphysis, and may play a role in calcification. 5. Needle-like apatite crystals (Fig. 2).Blocks of formalin-fixed epiphysis from weanling mice were digested with the following agents in 0.1M phosphate buffer: a) 5% ethylenediaminetetraacetate (EDTA) at pH 8.3, b) 0.015% bovine testicular hyaluronidase (Sigma, type IV, 750 units/mg) at pH 5.5, and c) 0.1% collagenase (Worthington, chromatograhically pure, 200 units/mg) at pH 7.4. All digestions were carried out at 37°C overnight. Following digestion tissues were examined by light and electron microscopy to determine changes in the various fibrils and particles of the matrix.

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