Identification of molecules in leech extracellular matrix that promote neurite outgrowth

1988 ◽  
Vol 235 (1280) ◽  
pp. 247-257 ◽  

The molecular composition of the substrate is of critical importance for neurite extension by isolated identified leech nerve cells in culture. One substrate upon which rapid growth occurs in defined medium is a cellfree extract of extracellular matrix (ECM) that surrounds the leech central nervous system (CNS). Here we report the co-purification of neurite-promoting activity with a laminin-like molecule. High molecular mass proteins from leech ECM purified by gel filtration exhibited increased specific activity for promoting neurite outgrowth. The most active fractions contained three major polypeptide bands of ca . 340, 250 and 220 kDa. Electron microscopy of rotary-shadowed samples showed three macromolecules, one of which had a cross-shaped structure similar to vertebrate laminin. A second six-armed molecule resembled vertebrate tenascin and a third rod-like molecule resembled vertebrate collagen type IV. The most active fractions contained a protein of ca . 1 MDa on non-reducing gels with disulphide-linked subunits of ca . 220 and 340 kDa, with cross-shaped laminin-like molecules. We conclude that a laminin-like molecule represents a major neurite promoting component present in leech ECM. The experiments represent a first step in determining the location of leech laminin within the CNS and assessing its role in neurite outgrowth during development and regeneration.

1994 ◽  
Vol 107 (12) ◽  
pp. 3379-3392
Author(s):  
G. Carmeliet ◽  
B. Himpens ◽  
J.J. Cassiman

Regulation of beta 1 integrins in neurite outgrowth following N6,2′-O-dibutyryladenosine 3′:5′-cyclic monophosphate (dBcAMP) treatment was investigated using the human neuroblastoma cell line TR 14. Three beta 1 integrins were identified: the alpha 1 beta 1 receptor bound collagen type I, collagen type IV and probably laminin; the alpha 2 beta 1 integrin bound collagen type I; and the alpha v beta i receptor bound fibronectin. Neurite extension was detectable as early as 30 minutes following dBcAMP treatment, was maximal after 24 hours and remained constant during treatment for 4 days. Adhesion-perturbing beta 1 subunit-specific antibodies, added together with dBcAMP, prevented the outgrowth of new neurites. During the first 24 hours of neurite outgrowth, no change was observed in the amount of beta 1 integrins nor in their topographic distribution. However, dBcAMP treatment increased the binding of alpha 1 beta 1 receptors to collagen type IV-Sepharose by a factor 2.3 +/- 0.6 (P < 0.02), while no alteration in the binding to collagen type I was detected. Moreover, neurites and growth cones were immunoreactive for collagen type IV but not for collagen type I. Consistently dBcAMP-induced neurite outgrowth was inhibited by adhesion-perturbing alpha 1 subunit-specific antibodies. Following maximal neurite outgrowth, the amount of beta 1 integrins determined by immunoprecipitation and by confocal microscopy decreased to 58.3 +/- 11.2% (P < 0.001) and to 55.4 +/- 17.5% (P < 0.001) of untreated levels, respectively, without any change in the level of beta 1 mRNA or de novo synthesized beta 1 precursor. However, pulse-chase experiments showed an increased turnover of the beta 1 subunit: the amount of beta 1 precursor that was degraded after 1 hour chase was 50.5 +/- 8.4% in cells treated for 4 days and 34.2 +/- 3.9% in untreated cells (P < 0.02); the amount of mature beta 1 after 24 hours chase was smaller in cells treated for 4 days compared to untreated cells. In conclusion, during neurite outgrowth, alpha 1 beta 1 integrins are required and acquire an enhanced binding activity for collagen type IV; but following maximal neurite outgrowth, expression of beta 1 integrins is reduced.


2019 ◽  
Vol 317 (6) ◽  
pp. F1680-F1694 ◽  
Author(s):  
Gek Cher Chan ◽  
Diana G. Eng ◽  
Jeffrey H. Miner ◽  
Charles E. Alpers ◽  
Kelly Hudkins ◽  
...  

In healthy glomeruli, parietal epithelial cell (PEC)-derived extracellular matrix (ECM) proteins include laminin-β1, perlecan, and collagen type IV-α2 and podocyte-specific ECM proteins include laminin-β2, agrin, and collagen type IV-α4. This study aimed to define individual ECM protein isoform expression by PECs in both experimental and human focal segmental glomerulosclerosis (FSGS) and diabetic nephropathy (DN) and to determine if changes were CD44 dependent. In experimental FSGS induced with a cytotoxic podocyte antibody and in the BTBR ob/ob mouse model of DN, PEC-derived protein staining was significantly increased in PECs. Dual staining also showed de novo expression of the podocyte-specific ECM proteins laminin-β2 and agrin in PECs. Similar findings were observed in biopsies from patients with FSGS and DN. Increases in individual ECM proteins colocalized with CD44 in PECs in disease. To determine the role of CD44, FSGS was induced in CD44−/− and CD44+/+ mice. PEC staining for perlecan, collagen type IV-α2, laminin-β2, and agrin were significantly lower in diseased CD44−/− mice compared with diseased CD44+/+ mice. These results show that in experimental and human FSGS and DN, PECs typically in an activated state, produce both PEC-derived and podocyte-specific ECM protein isoforms, and that the majority of these changes were dependent on CD44.


2004 ◽  
Vol 16 (2) ◽  
pp. 218 ◽  
Author(s):  
K.B. Stewart ◽  
A.M. Adams ◽  
S.L. Pratt ◽  
S.L. Stice

A porcine trophoblastic cell line could provide a powerful model for understanding trophoblast cell biology as well as placental gene expression and proteomics in vitro. In this experiment, we derived porcine trophoblastic cells from trophectoderm tissue and assessed their growth on three different extracellular matrix substrates and in three different concentrations of human recombinant bone morphogenetic protein 4 (hBMP4). Human BMP4 has been shown to induce differentiation of human embryonic stem cells into trophoblast lineages. Elongated embryos were flushed using DPBS supplemented with 1% fetal calf serum and penicillin-streptomycin (1X) from the hysterectomized uteri of superovulated and bred prepuberal gilts 15 days post-insemination. The embryonic disc was visualized with a dissecting microscope. The trophectoderm tissue was cut 2–3mm away from the embryonic disc with a scalpel and the trophectoderm tissue was manually dissected into cell aggregates. These aggregates were plated on collagen type IV, Matrigel, and human extracellular matrix (laminin, collagen type IV and heparan sulfate proteoglycan derived from human placenta) in culture medium (DMEM with 15% FCS, 0.1mM 2-mercaptoethanol, 4ngmL−1 basic FGF4 and 1X P/S) in the presence or absence of hBMP4 at 0, 10, or 20ngmL−1. Cell outgrowth was observed within 24 hours of culture. After three days of culture, various cell types (based on size and morphology) were present. Among cultures of predominant large cells were colonies of smaller cells with epithelial-type morphology that had a prominent nucleus and a high nuclear-to-cytoplasmic ratio. The epithelial-type cells grew in tight colonies with definite borders and contained cytoplasmic structures resembling lipid-containing vesicles. These colonies initially appeared on all matrices across all hBMP4 concentrations. After seven days in culture the colonies developed distinct differences across groups. Cell growth on collagen was comprised of tight colonies having definite borders among large cells. Colonies on collagen were larger and more pronounced in both the hBMP4-supplemented groups than when cultured without hBMP4. The Matrigel coated plates contained large sheets of epithelial-type cell growth instead of compact colonies. This type of growth characteristic was present in all hBMP4 treatments on Matrigel. In contrast, few cells survived and propagated on human extracellular matrix. Only small colonies having the desired morphology were among the large cells on human extracellular matrix when cultured in medium containing 10ngmL−1 hBMP4. Cells were passaged and only cells growing on Matrigel could be further cultured. These data suggest that both the cell substrate and hBMP4 affect initial trophoblast outgrowths. Further analysis including immunocytochemistry and RT-PCR is currently being performed to better characterize these cells. Epidemiology/Diseases


2021 ◽  
Vol 73 (1) ◽  
pp. 103-110
Author(s):  
Braca Kundalic ◽  
Sladjana Ugrenovic ◽  
Ivan Jovanovic ◽  
Vladimir Petrovic ◽  
Aleksandar Petrovic ◽  
...  

The aim of this study was to analyze the expression of extracellular matrix (ECM) proteins in human endoneurium during aging. We harvested 15 cadaveric sural nerves, distributed in 3 age groups (I: 25-44, II: 45-64, III: 65-86 years old). Histological sections were stained immunohistochemically for the presence of collagen type I, type IV and laminin, and the ImageJ processing program was used in morphometrical analysis to determine the percentages of these endoneurial proteins. In two younger groups, the endoneurial matrix of the sural nerve was composed from about equal proportions of these proteins, which may be considered a favorable microenvironment for the regeneration of nerve fibers. Linear regression analysis showed a significant increase in endoneurial collagen type IV with age, while collagen type I and laminin significantly decreased during the aging process. In cases older than 65 years, remodeling of the endoneurial matrix was observed to be significantly higher for the presence of collagen type IV, and lower for the expression of collagen type I and laminin. This age-related imbalance of ECM proteins could represent a disadvantageous microenvironment for nerve fiber regeneration in older adults. Our findings contribute to the development of therapeutic approaches for peripheral nerve regeneration.


2019 ◽  
Author(s):  
Tingting Ji ◽  
Kai Wang ◽  
Jiale Fan ◽  
Jichang Huang ◽  
Mengqing Wang ◽  
...  

ABSTRACTSynapses are largely established during embryogenesis and maintained during growth. The mechanisms that regulate synaptic allometry—the maintenance of synaptic positions during growth—are largely unknown. We performed forward genetic screens inC. elegansfor synaptic allometry mutants and identifiedmig-17, a secreted metalloprotease of the conserved ADAMTS family. Through proteomic mass spectrometry analyses, cell biological and genetic studies we determined that MIG-17 is expressed by muscle cells to modulate glia location and morphology. Glia are proximal to synapses, and the glial location and morphology determine synaptic position during growth.Mig-17regulates synapse allometry by influencing epidermal-glia crosstalk through the regulation of basement membrane proteins, including collagen type IV, SPARC and fibulin. Our findings underscore the importance of glia location in the maintenance of synaptic allometry, and uncover a muscle-epidermal-glia signaling axis, mediated through the extracellular matrix, in the regulation of glia morphology and synaptic positions during growth.


Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Alexis Mack ◽  
Michael Maniskas ◽  
Caroline Reynolds ◽  
Akihiko Urayama

Objective: Cerebral ischemia affects the mechano-response of vasculature and the remodeling of extracellular matrix (ECM) components. The present study investigates how oxygen-glucose deprivation (OGD) affects the brain endothelial cell (BEC) stiffness. We further aim to study whether ECM components affect the cellular stiffness in normal and energy deprived conditions. Methods: Primary human BECs received a 16h OGD followed by the reperfusion with normal culture media. Young’s Modulus (YM) and topography in the BEC surface were determined by atomic force microscopy (AFM). To test the effect of ECM composition on the BEC stiffness, various concentrations (5-500 uM) of collagen type IV were used for culture dish coating. BECs on the coating beds underwent 16h OGD and served for YM measurements. Per dish, 10-20 single BECs were measured. Results: BECs under OGD conditions became significantly stiffer (2.1-fold, *P<0.05) than the normoxic control, and the increased stiffness sustained even after the reperfusion for 24h, indicating energy deprivation is a primary factor for the increased stiffness under acute stress conditions. AFM topography confirmed that OGD induced rough and filamentous plasma membrane surface in BECs, suggesting a cytoskeletal change was induced by OGD. BECs grown on a 10x denser collagen type IV (500 uM) layer showed a significant increase (2.3-fold, ***P<0.001) in cellular stiffness, compared with the conventional concentration of 50 uM, suggesting that denser extracellular matrix makes BEC stiffer. Also, in BECs cultured on a denser ECM layer, OGD response was absent in terms of cellular stiffness. Conclusion: The present study found that OGD increased BEC stiffness. In addition, increasing the density of the ECM alone was enough to generate stiffer BECs. These mechanical properties of BECs may be a physical factor mediating endothelial responses after stroke.


1992 ◽  
Vol 119 (6) ◽  
pp. 1721-1728 ◽  
Author(s):  
V M Paralkar ◽  
B S Weeks ◽  
Y M Yu ◽  
H K Kleinman ◽  
A H Reddi

Bone morphogenetic protein 2B (BMP 2B, also known as BMP 4) induces cartilage and bone morphogenesis in ectopic extraskeletal sites. BMP 2B is one of several bone morphogenetic proteins which along with activins and inhibins are members of the transforming growth factor-beta (TGF-beta) family. Both BMP 2B and activin A, but not TGF-beta 1, induce rat pheochromocytoma PC12 neuronal cell differentiation and expression of VGF, a nervous system-specific mRNA. PC12 cells exhibited approximately 2,500 receptors per cell for BMP 2B with an apparent dissociation constant of 19 pM. Extracellular matrix components, including fibronectin, laminin, and collagen type IV potentiated the activity of BMP and activin A, with the latter being the most active. Direct experiments demonstrated that radioiodinated BMP 2B bound to collagen type IV better than to either laminin or fibronectin. These data demonstrate a common neurotrophic activity of both BMP 2B and activin A, and suggest that these regulatory molecules alone and in conjunction with extracellular matrix components may play a role in both the development and repair of nervous tissue.


2003 ◽  
Vol 71 (2) ◽  
pp. 1008-1010 ◽  
Author(s):  
Bradford S. McGwire ◽  
Kwang-Poo Chang ◽  
David M. Engman

ABSTRACT Leishmania species engineered to express high levels of the surface metalloprotease gp63 have enhanced capacity of migration through extracellular matrix in vitro. This correlates with gp63 degradation of extracellular matrix components, such as collagen type IV and fibronectin, and suggests an important role for gp63 in the pathogenesis of leishmaniasis.


Pathobiology ◽  
1994 ◽  
Vol 62 (2) ◽  
pp. 55-58 ◽  
Author(s):  
Alexander Berndt ◽  
Hariwig Kosmehl ◽  
Detlef Katenkamp ◽  
Volker Tauchmann

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