scholarly journals Laminin promotes neuritic regeneration from cultured peripheral and central neurons.

1983 ◽  
Vol 97 (6) ◽  
pp. 1882-1890 ◽  
Author(s):  
M Manthorpe ◽  
E Engvall ◽  
E Ruoslahti ◽  
F M Longo ◽  
G E Davis ◽  
...  

The ability of axons to grow through tissue in vivo during development or regeneration may be regulated by the availability of specific neurite-promoting macromolecules located within the extracellular matrix. We have used tissue culture methods to examine the relative ability of various extracellular matrix components to elicit neurite outgrowth from dissociated chick embryo parasympathetic (ciliary ganglion) neurons in serum-free monolayer culture. Purified laminin from both mouse and rat sources, as well as a partially purified polyornithine-binding neurite promoting factor (PNPF-1) from rat Schwannoma cells all stimulate neurite production from these neurons. Laminin and PNPF-1 are also potent stimulators of neurite growth from cultured neurons obtained from other peripheral as well as central neural tissues, specifically avian sympathetic and sensory ganglia and spinal cord, optic tectum, neural retina, and telencephalon, as well as from sensory ganglia of the neonatal mouse and hippocampal, septal, and striatal tissues of the fetal rat. A quantitative in vitro bioassay method using ciliary neurons was used to (a) measure and compare the specific neurite-promoting activities of these agents, (b) confirm that during the purification of laminin, the neurite-promoting activity co-purifies with the laminin protein, and (c) compare the influences of antilaminin antibodies on the neurite-promoting activity of laminin and PNPF-1. We conclude that laminin and PNPF-1 are distinct macromolecules capable of expressing their neurite-promoting activities even when presented in nanogram amounts. This neurite-promoting bioassay currently represents the most sensitive test for the biological activity of laminin.

Development ◽  
2001 ◽  
Vol 128 (19) ◽  
pp. 3773-3782 ◽  
Author(s):  
Eri Hashino ◽  
Marlene Shero ◽  
Dirk Junghans ◽  
Hermann Rohrer ◽  
Jeffrey Milbrandt ◽  
...  

During development, parasympathetic ciliary ganglion neurons arise from the neural crest and establish synaptic contacts on smooth and striate muscle in the eye. The factors that promote the ciliary ganglion pioneer axons to grow toward their targets have yet to be determined. Here, we show that glial cell line-derived neurotrophic factor (GDNF) and neurturin (NRTN) constitute target-derived factors for developing ciliary ganglion neurons. Both GDNF and NRTN are secreted from eye muscle located in the target and trajectory pathway of ciliary ganglion pioneer axons during the period of target innervation. After this period, however, the synthesis of GDNF declines markedly, while that of NRTN is maintained throughout the cell death period. Furthermore, both in vitro and in vivo function-blocking of GDNF at early embryonic ages almost entirely suppresses ciliary axon outgrowth. These results demonstrate that target-derived GDNF is necessary for ciliary ganglion neurons to innervate ciliary muscle in the eye. Since the down-regulation of GDNF in the eye is accompanied by down-regulation of GFRα1 and Ret, but not of GFRα2, in innervating ciliary ganglion neurons, the results also suggest that target-derived GDNF regulates the expression of its high-affinity coreceptors.


Author(s):  
Maria Veronica Lipreri ◽  
Nicola Baldini ◽  
Gabriela Graziani ◽  
Sofia Avnet

As life expectancy increases, the population experiences progressive ageing. Ageing, in turn, is connected to an increase in bone-related diseases (i.e., osteoporosis and increased risk of fractures). Hence, the search for new approaches to study the occurrence of bone-related diseases and to develop new drugs for their prevention and treatment becomes more pressing. However, to date, a reliable in vitro model that can fully recapitulate the characteristics of bone tissue, either in physiological or altered conditions, is not available. Indeed, current methods for modelling normal and pathological bone are poor predictors of treatment outcomes in humans, as they fail to mimic the in vivo cellular microenvironment and tissue complexity. Bone, in fact, is a dynamic network including differently specialized cells and the extracellular matrix, constantly subjected to external and internal stimuli. To this regard, perfused vascularized models are a novel field of investigation that can offer a new technological approach to overcome the limitations of traditional cell culture methods. It allows the combination of perfusion, mechanical and biochemical stimuli, biological cues, biomaterials (mimicking the extracellular matrix of bone), and multiple cell types. This review will discuss macro, milli, and microscale perfused devices designed to model bone structure and microenvironment, focusing on the role of perfusion and encompassing different degrees of complexity. These devices are a very first, though promising, step for the development of 3D in vitro platforms for preclinical screening of novel anabolic or anti-catabolic therapeutic approaches to improve bone health.


Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4157-4164
Author(s):  
J.S. Cameron ◽  
L. Dryer ◽  
S.E. Dryer

The developmental expression of macroscopic Ca(2+)-activated K(+) currents in chick ciliary ganglion neurons is dependent on an avian ortholog of TGFbeta1, known as TGFbeta4, secreted from target tissues in the eye. Here we report that a different isoform, TGFbeta3, is also expressed in a target tissue of ciliary ganglion neurons. Application of TGFbeta3 inhibits the functional expression of whole-cell Ca(2+)-activated K(+) currents evoked by 12 hour treatment with either TGFbeta1 or beta-neuregulin-1 in ciliary ganglion neurons developing in vitro. TGFbeta3 had no effect on voltage-activated Ca(2+) currents. A neutralizing antiserum specific for TGFbeta3 potentiates stimulation of Ca(2+)-activated K(+) currents evoked by a target tissue (iris) extract in cultured ciliary ganglion neurons, indicating that TGFbeta3 is an inhibitory component of these extracts. Intraocular injection of TGFbeta3 causes a modest but significant inhibition of the expression of Ca(2+)-activated K(+) currents in ciliary ganglion neurons developing in vivo. Further, intraocular injection of a TGFbeta3-neutralizing antiserum stimulates expression of Ca(2+)-activated K(+) currents in ciliary ganglion neurons developing in vivo, indicating that endogenous TGFbeta3 regulates the functional expression of this current. The normal developmental expression of functional Ca(2+)-activated K(+) currents in ciliary ganglion neurons developing in vivo is therefore regulated by two different target-derived isoforms of TGFbeta, which produce opposing effects on the electrophysiological differentiation of these neurons.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
Wayne Carver ◽  
Edie C. Goldsmith

The biomechanical environment plays a fundamental role in embryonic development, tissue maintenance, and pathogenesis. Mechanical forces play particularly important roles in the regulation of connective tissues including not only bone and cartilage but also the interstitial tissues of most organs.In vivostudies have correlated changes in mechanical load to modulation of the extracellular matrix and have indicated that increased mechanical force contributes to the enhanced expression and deposition of extracellular matrix components or fibrosis. Pathological fibrosis contributes to dysfunction of many organ systems. A variety ofin vitromodels have been utilized to evaluate the effects of mechanical force on extracellular matrix-producing cells. In general, application of mechanical stretch, fluid flow, and compression results in increased expression of extracellular matrix components. More recent studies have indicated that tissue rigidity also provides profibrotic signals to cells. The mechanisms whereby cells detect mechanical signals and transduce them into biochemical responses have received considerable attention. Cell surface receptors for extracellular matrix components and intracellular signaling pathways are instrumental in the mechanotransduction process. Understanding how mechanical signals are transmitted from the microenvironment will identify novel therapeutic targets for fibrosis and other pathological conditions.


2016 ◽  
Vol 84 (11) ◽  
pp. 3243-3251 ◽  
Author(s):  
Haley E. Adcox ◽  
Erin M. Vasicek ◽  
Varun Dwivedi ◽  
Ky V. Hoang ◽  
Joanne Turner ◽  
...  

Salmonella enterica serovar Typhi, the causative agent of typhoid fever in humans, forms biofilms encapsulated by an extracellular matrix (ECM). Biofilms facilitate colonization and persistent infection in gallbladders of humans and mouse models of chronic carriage. Individual roles of matrix components have not been completely elucidated in vitro or in vivo . To examine individual functions, strains of Salmonella enterica serovar Typhimurium, the murine model of S . Typhi, in which various ECM genes were deleted or added, were created to examine biofilm formation, colonization, and persistence in the gallbladder. Studies show that curli contributes most significantly to biofilm formation. Expression of Vi antigen decreased biofilm formation in vitro and virulence and bacterial survival in vivo without altering the examined gallbladder pro- or anti-inflammatory cytokines. Oppositely, loss of all ECM components (Δ wcaM Δ csgA Δ yihO Δ bcsE ) increased virulence and bacterial survival in vivo and reduced gallbladder interleukin-10 (IL-10) levels. Colanic acid and curli mutants had the largest defects in biofilm-forming ability and contributed most significantly to the virulence increase of the Δ wcaM Δ csgA Δ yihO Δ bcsE mutant strain. While the Δ wcaM Δ csgA Δ yihO Δ bcsE mutant was not altered in resistance to complement or growth in macrophages, it attached and invaded macrophages better than the wild-type (WT) strain. These data suggest that ECM components have various levels of importance in biofilm formation and gallbladder colonization and that the ECM diminishes disseminated disease in our model, perhaps by reducing cell attachment/invasion and dampening inflammation by maintaining/inducing IL-10 production. Understanding how ECM components aid acute disease and persistence could lead to improvements in therapeutic treatment of typhoid fever patients.


2020 ◽  
Author(s):  
Shinji Iizuka ◽  
Ronald P. Leon ◽  
Kyle P. Gribbin ◽  
Ying Zhang ◽  
Jose Navarro ◽  
...  

ABSTRACTThe scaffold protein Tks5α is required for invadopodia-mediated cancer invasion both in vitro and in vivo. We have previously also revealed a role for Tks5 in tumor cell growth using three-dimensional (3D) culture model systems and mouse transplantation experiments. Here we use both 3D and high-density fibrillar collagen (HDFC) culture to demonstrate that native type I collagen, but not a form lacking the telopeptides, stimulated Tks5-dependent growth, which was dependent on the DDR collagen receptors. We used microenvironmental microarray (MEMA) technology to determine that laminin, collagen I, fibronectin and tropoelastin also stimulated invadopodia formation. A Tks5α-specific monoclonal antibody revealed its expression both on microtubules and at invadopodia. High- and super-resolution microscopy of cells in and on collagen was then used to place Tks5α at the base of invadopodia, separated from much of the actin and cortactin, but coincident with both matrix metalloprotease and cathepsin proteolytic activity. Inhibition of the Src family kinases, cathepsins or metalloproteases all reduced invadopodia length but each had distinct effects on Tks5α localization. These studies highlight the crosstalk between invadopodia and extracellular matrix components, and reveal the invadopodium to be a spatially complex structure.


1987 ◽  
Vol 104 (2) ◽  
pp. 363-370 ◽  
Author(s):  
L W Role ◽  
G D Fischbach

The purpose of this study was to describe the shape of chick ciliary ganglion neurons dissociated from embryonic day 8 or 9 ganglia and maintained in vitro. Most of the neurons were multipolar during the first three days after plating, with an average of 6.0 processes extending directly from the cell body. The neurons became unipolar with time. The remaining primary process accounted for greater than 90% of the total neuritic arbor. This striking change in morphology was not due to the selective loss of multipolar cells, or to an obvious decline in the health of apparently intact cells. The retraction of processes was neither prevented nor promoted by the presence of embryonic muscle cells. Process pruning occurred to the same extent and over the same time course whether the cells were plated on a monolayer of embryonic myotubes or on a layer of lysed fibroblasts. Process retraction is not an inevitable consequence of our culture conditions. Motoneurons dissociated from embryonic spinal cords remained multipolar over the same period of time. We conclude that ciliary ganglion neurons breed true in dissociated cell culture in that the multipolar-unipolar transition reflects their normal, in vivo, developmental program.


2018 ◽  
Vol 115 (46) ◽  
pp. E10869-E10878 ◽  
Author(s):  
Ivano Amelio ◽  
Mara Mancini ◽  
Varvara Petrova ◽  
Rob A. Cairns ◽  
Polina Vikhreva ◽  
...  

Mutations in the TP53 gene and microenvironmentally driven activation of hypoxia-inducible factor-1 (HIF-1) typically occur in later stages of tumorigenesis. An ongoing challenge is the identification of molecular determinants of advanced cancer pathogenesis to design alternative last-line therapeutic options. Here, we report that p53 mutants influence the tumor microenvironment by cooperating with HIF-1 to promote cancer progression. We demonstrate that in non-small cell lung cancer (NSCLC), p53 mutants exert a gain-of-function (GOF) effect on HIF-1, thus regulating a selective gene expression signature involved in protumorigenic functions. Hypoxia-mediated activation of HIF-1 leads to the formation of a p53 mutant/HIF-1 complex that physically binds the SWI/SNF chromatin remodeling complex, promoting expression of a selective subset of hypoxia-responsive genes. Depletion of p53 mutants impairs the HIF-mediated up-regulation of extracellular matrix (ECM) components, including type VIIa1 collagen and laminin-γ2, thus affecting tumorigenic potential of NSCLC cells in vitro and in mouse models in vivo. Analysis of surgically resected human NSCLC revealed that expression of this ECM gene signature was highly correlated with hypoxic tumors exclusively in patients carrying p53 mutations and was associated with poor prognosis. Our data reveal a GOF effect of p53 mutants in hypoxic tumors and suggest synergistic activities of p53 and HIF-1. These findings have important implications for cancer progression and might provide innovative last-line treatment options for advanced NSCLC.


Blood ◽  
2013 ◽  
Vol 122 (21) ◽  
pp. 3695-3695
Author(s):  
Alessandro Malara ◽  
Cristian Gruppi ◽  
Manuela Currao ◽  
Alessandra Balduini

Abstract Introduction the bone marrow microenvironment consists of various types of cells and their secreted extracellular matrix components that surround capillary-venous sinusoids, and plays a key role in the regulation of hematopoiesis. In general, extracellular matrix components interact with each other to form a structural framework that supports tissue organization and positional cues that regulate cellular processes. Megakaryocytes are rare cells in the bone marrow and, besides platelet release, growing evidences attribute new functions to these cells in the generation and maintenance of the bone marrow cell niche. Recent evidences, by our group, demonstrated that megakaryocytes are involved in matrix deposition and remodeling, as demonstrated by their role in fibronectin fibrillogenesis and the expression of matrix cross-linking enzymes, such as factor XIIIa, essential in the dynamic of megakaryocyte-matrix component interactions. Interestingly, individual extracellular matrix components were demonstrated to play a role in the regulation of megakaryocytes development in vitro. Fibronectin was shown to regulate megakaryocyte maturation and proplatelet extension, while type III and type IV collagens were demonstrated to support proplatelet formation in vitro. In contrast, type I collagen is an important physiological inhibitor of platelet release in vitro. However, little is known about the exact localization as well as function of these matrix components in vivo. Results in this work we have analyzed the spatial distribution of megakaryocytes and extracellular matrix components by immunofluorescence in murine femur sections. We found that megakaryocytes were predominantly located in the femur diaphysis with only 20% of megakaryocytes within 50μm from the endosteal surface and more than 80% of megakaryocytes located less than 50 μm from a sinusoid. Correlation between megakaryocyte distance from sinusoids and dimension suggested a gradient of maturing megakaryocytes towards the vascular niche. Next, we deciphered bone marrow extracellular matrix component composition by western blotting and mapped the location in situ of different collagens (I, III, IV, VI) and glycoproteins (fibronectin, laminin). We found that all these proteins were differently located in the endosteal and sinusoidal districts supporting the concept that regulation of hemopoiesis, in the bone marrow, may also depend from matrix distribution. Further, we showed, for the first time, that megakaryocytes were surrounded by a pericellular matrix mainly composed of fibronectin, laminin and type IV collagen. Interestingly, these three proteins were also demonstrated to promote thrombopoietin-dependent megakaryocyte differentiation in in vitro cultures of bone marrow hemopoietic progenitor cells. Finally, fibronectin, laminin and type IV collagen were also demonstrated to be expressed and synthesized by differentiated megakaryocytes in vitro as demonstrated by PCR and western blotting analysis. Most importantly, megakaryocyte expression of these extracellular matrix components was up-regulated in vivo during bone marrow reconstitution upon drug induced myelosuppression and, at a lesser extent, thrombocytopenia. Conclusions all together these results suggested that megakaryocytes are important extracellular matrix component-producing bone marrow cells and that released extracellular matrix components support megakaryopoiesis and concur to the generation of bone marrow niches. Disclosures: No relevant conflicts of interest to declare.


Sign in / Sign up

Export Citation Format

Share Document