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Publication Date:
01/03/2001
on Journal of cellular physiology
by Barbarisi A, Petillo O, Di Lieto A, Melone MA, Margarucci S, Cannas M, Peluso G
DOI: 10.1002/1097-4652(2000)9999:999<000::AID-JCP1040>3.0.CO;2-E
The mechanism by which estradiol (E2) acts on cell proliferation is still unclear. In this paper, we report the results of a series of experiments in an attempt to elucidate the effector pathway(s) involved in coupling the E2 receptors binding to cellular growth response in leiomyoma cells (LSMC). Under conditions of E2-dependent growth, E2 treatment of LSMC triggers rapid and transient activation of the MAP-kinase pathway. Interestingly, we demonstrate that the early downstream signal transduction events determined by E2-stimulation in quiescent LSMC, including the rapid protein tyrosine phosphorylation of a subset of intracellular proteins, such GAP, PI-3-K, and PLCgamma, and the concomitant activation of ancillary protein kinases, are related to E2-induced PDGF secretion. Moreover, we identify the PDGF, alone or in association with other growth factors, as the main growth factor involved in the proliferation response of LSMC to E2 stimulation. The addition of neutralizing antibodies anti-PDGF was able to inhibit the mitogenic activity present in LSMC conditioned media samples. On the other hand, E2 did not affect the constitutive expression as well as the ligand affinity of PDGF receptors on LSMC plasmamembrane. Cell treatment with the antiestrogen ICI 182780 correlate both with a perturbation of E2-induced transductional circuit and with the disappearance of the mitogenic factor, PDGF, in LSMC conditioned media; the latter therefore, represents the main autocrine mediator of cell growth modulation, upregulated by E2 and down-regulated by antiestrogenic compound. Our experiments suggest that growth factor secretion is an initial and integral part of the signaling events mediated by the estradiol receptors, not related, at least in part, to E2 transcriptional modulation.
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Publication Date:
01/10/2000
on Journal of cellular physiology
by Melone MA, Peluso G, Galderisi U, Petillo O, Cotrufo R
DOI: 10.1002/1097-4652(200010)185:1<143::AID-JCP14>3.0.CO;2-U
In DMD the progressive loss of muscle ability and concomitant increasing fibrosis might originate from, besides other causes, the fibroblast paracrine inhibition of satellite cell "growth." In this study we report that in myoblast/fibroblast coculture experiments, the presence of DMD fibroblasts negatively interfered with DMD myoblast growth to an extent directly proportional to the percentage of DMD fibroblasts present in the mixed-cell cultures. Moreover, the observation that media conditioned with proliferating DMD fibroblasts inhibited the growth of DMD myoblasts more seriously than did control fibroblast-conditioned media suggested a paracrine effect by diffusible factors. IGF-binding proteins could act as such diffusible factors; in fact, IGFBP-5 transcript increased threefold in DMD fibroblasts proliferating in DMD muscle extracts, whereas IGFBP-3 mRNA decreased. In addition, high levels of IGFBP-5 protein were detected in DMD fibroblast-conditioned media. In neutralizing IGFBP-5 in DMD fibroblast-conditioned media by means of specific antibodies, or inhibiting IGFBP-5 gene expression in DMD fibroblasts by means of oligo antisense, the fibroblast-conditioned media lost inhibitory power over DMD myoblast proliferation.
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Publication Date:
01/11/1999
on Journal of cellular biochemistry
by Melone MA, Peluso G, Petillo O, Galderisi U, Cotrufo R
As the molecular basis of Duchenne Muscular Dystrophy (DMD) was being discovered, increasing focus was placed on the mechanisms of progressive failure of myoregeneration. In this study, we propose a pathogenesis model for DMD, where an autocrine growth factor release of TGF-beta1-from necrotic myofibers-could contribute to the increasing loss of muscle regeneration. In fact, we report evidence that DMD myoblasts reduce their proliferation rate, in time and later cultures; in connection with this, we observed TGF-beta1 increase in conditioned media of DMD myoblasts, able to control the myoblast growth by reducing fusion and differentiation of DMD satellite cells.
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Publication Date:
01/10/1999
on Journal of materials science. Materials in medicine
by Petillo O, Margarucci S, Peluso G, Barbarisi A, Melone MA, Ambrosio L, Nicolais L
The understanding of substrate dependence of cellular differentiation is important in the surface design of biocompatible artificial devices as well as cell-incorporated tissue engineered devices. In an attempt to understand some of the genetic and epigenetic aspects of the control of cell differentiation in the presence of two different materials, Chronoflex (CH) and plasma treated Chronoflex coated with Hyaluronan (CH-HA), we used primary cultures of human myogenic cells, a model that encompasses cell proliferation, migration, fusion, and differentiation dependent gene activation. By testing both the material samples on the growth of human myoblasts in primary cultures, we demonstrated that both CH and CH-HA substrates were able to support the cell growth since they did not affect cell count and DNA synthesis. On the contrary, the degree of myoblast differentiation, assessed as a function of creatine phosphokinase (CPK) activity on living cells, was completely different on the two biomaterials. Indeed, the amount of CPK increased on CH-HA cultured cells as a result of myotube formation, while CH grown myoblasts remained unfused and displayed no increase on the CPK activity even after 12 days culture. Moreover, the expression level of MyoD and myogenin mRNA, both related to myogenic cell differentiation, appeared extremely low in CH-grown cells, while they were rapidly induced in CH-HA cultured myoblasts.
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Publication Date:
01/09/1999
on Journal of cellular biochemistry
by Galderisi U, Di Bernardo G, Cipollaro M, Jori FP, Piegari E, Cascino A, Peluso G, Melone MA
Bin1 is a novel protein that specifically binds Myc and inhibits, at least in part, Myc transactivation. Bin1 seems to play a role in cell cycle control, acting as a tumor suppressor gene. Since MYC family genes play a regulatory role in the proliferation, differentiation, and apoptosis of the nervous system, we studied the effects of the overexpression of the Myc-interacting protein, Bin1, in neuroblastoma and astrocytoma cell lines, which were chosen as neural cell system models. The major effects of BIN1 overexpression observed in undifferentiated neuroblastoma and astrocytoma cells were a significant reduction of cell growth, an increase in the G(0)/G(1) cell population and the induction of apoptosis. The trigger of programmed cell death by Bin1 is described for the first time. Bin1 overexpression in undifferentiated cells did not induce any maturation process as neither neuronal nor astrocyte differentiation markers were upregulated in neuroblastoma and astrocytoma cells, respectively. On the other side, the effects of Bin1 overproduction in neuroblastoma and astrocytoma cells committed towards neuronal and astrocyte differentiation, respectively, were different from those observed in undifferentiated cells. Although we did not evidence any triggering of programmed cell death, we did notice a further induction towards more differentiated phenotypes. Our studies suggest that Bin1 overexpression in neuroblastoma and astrocytoma cells can result in one of the following pathways: (1) suppressed cell proliferation, (2) induced differentiation, or (3) apoptosis. Thus, it appears that Bin1 operates through different pathways that involve activation of different genes: the chosen pathway however will depend on the proliferating or differentiated state of the cell.
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Publication Date:
01/07/1999
on Journal of cellular biochemistry
by Galderisi U, Di Bernardo G, Melone MA, Galano G, Cascino A, Giordano A, Cipollaro M
Phosphorothioate (PS) antisense oligonucleotides are currently used to inhibit many cell functions both in vivo and in vitro. However, these modified oligos provide reasonable sequence specificity only within a narrow concentration range. To overcome such a limitation we synthesized antisense oligomers, partially phosphorothioated, targeted against the human N-myc mRNA. We utilized such modified oligomers in a human neuroblastoma cell line where the N-myc gene expression was very high, and compared them to full phosphorothioate oligonucleotides. Both full PS and partial PS antisense oligos produced a maximum reduction in target mRNA after 6 h of treatment. They were able to maintain a good level of inhibition for 20 h only at high concentration. While partial PS oligos produced a dose dependent and sequence specific inhibition of N-myc mRNA, full PS molecules suffer from some disadvantages at the highest concentration used. Our results showed that partial PS molecules were capable of reducing gene expression showing a greater sequence specificity over a far broader concentration range. For this reason we conclude that partial PS antisense oligos, with respect to full PS antisense oligos, might be particularly useful for studying gene function.
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Publication Date:
01/04/1999
on Journal of cellular biochemistry
by Galderisi U, Di Bernardo G, Cipollaro M, Peluso G, Cascino A, Cotrufo R, Melone MA
To clarify the role and function of the N-myc product in cell differentiation and apoptosis, we used the antisense oligonucleotide technique to inhibit N-myc gene expression in neuroblastoma cells with different phenotypes: intermediate (I) and neuronal (N), or Schwann-glia (S), respectively. The results suggest that N-myc operates along different pathways. Inhibiting N-myc gene expression either results in suppression of cell proliferation or in induction of differentiation and/or apoptosis.
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Publication Date:
15/04/1998
on Archives of biochemistry and biophysics
by Gentile V, Sepe C, Calvani M, Melone MA, Cotrufo R, Cooper AJ, Blass JP, Peluso G
DOI: 10.1006/abbi.1998.0592
To investigate possible biochemical mechanisms underlying the "toxic gain of function" associated with polyglutamine expansions, the ability of guinea pig liver tissue transglutaminase to catalyze covalent attachments of various polyamines to polyglutamine peptides was examined. Of the polyamines tested, spermine is the most active substrate, followed by spermidine and putrescine. Formation of covalent cross links between polyglutamine peptides and polyamines yields high-M(r) aggregates--a process that is favored with longer polyglutamines. In the presence of tissue transglutaminase, purified glyceraldehyde-3-phosphate dehydrogenase (a key glycolytic enzyme that binds tightly to the polyglutamine domains of both huntingtin and dentatorubral-pallidoluysian atrophy proteins) is covalently attached to polyglutamine peptides in vitro, resulting in the formation of high-M(r) aggregates. In addition, endogenous glyceraldehyde-3-phosphate dehydrogenase of a Balb-c 3T3 fibroblast cell line overexpressing human tissue transglutaminase forms cross-links with a Q60 polypeptide added to the cell homogenate. Possibly, expansion of polyglutamine domains (thus far known to occur in the gene products associated with at least seven neurodegenerative diseases) leads to increased/aberrant tissue transglutaminase-catalyzed cross-linking reactions with both polyamines and susceptible proteins, such as glyceraldehyde-3-phosphate dehydrogenase. Formation of cross-linked heteropolymers may lead to deposition of high-M(r) protein aggregates, thereby contributing to cell death.
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Publication Date:
01/02/1998
on Antisense & nucleic acid drug development
by Melone MA, Galderisi U, Iacomino G, Cipollaro M, Di Bernardo G, Cotrufo R, Peluso G, Cascino A
DOI: 10.1089/oli.1.1998.8.25
By describing the behavior of myotonin mRNA levels, from the quiescent to the differentiated state in C2 mouse myoblasts, we produced evidence bearing on the role of myotonin gene product in the control of cell growth and differentiation. To study the role of myotonin in myotonic dystrophy (DM) pathogenesis, we developed a suitable cellular model where myotonin gene expression was modulated by phosphorothioate antisense oligonucleotides in C2 cultured cells. Furthermore, an isoform of the gene product, similar to that described in humans and not yet described in the mouse, was found.
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Publication Date:
05/03/1997
on Journal of biomedical materials research
by Peluso G, Petillo O, Anderson JM, Ambrosio L, Nicolais L, Melone MA, Eschbach FO, Huang SJ
Because of its chemical versatility and demonstrated biocompatibility, poly(2-hydroxyethyl methacrylate) (pHEMA) has been widely used as a polymer for biomedical applications. Since this hydrophilic material shows a poor interface with cells, blendings with other polymers were done to improve cytocompatibility. In our polymer, the presence of hydrophobic dominions on the material surface, due to the interpenetrating polymerization of pHEMA with poly(caprolactone) (PCL), seems to ameliorate the cytocompatibility in terms of cell adhesion and metabolism. For our experiments, we used IMR-90 human fibroblasts, as these cells strongly regulate DNA, RNA, and protein synthesis as anchorage-dependent variables. Cell attachment on a pHEMA/PCL interpenetrating polymer network was optimal, suggesting a strong adhesion between the cells and the polymer surface. Cell adhesion was weaker on pHEMA, as a significant fraction of the fibroblasts revealed a lack of spreading, with most cells remaining spherical. Moreover, only fibroblasts seeded on pHEMA significantly decreased mRNA synthesis; collagen production and cell shapes ranged from fully flat and proliferating, to minimally spread and nonproliferating. Finally, DNA synthesis, as a measure of cell proliferation, was markedly inhibited in cells cultured on pHEMA but not on pHEMA/PCL. In conclusion, our results suggest that control of cell growth and metabolism by biomedical polymers is based on physicochemical mechanism(s) in which the hydrophilicity/hydrophobicity ratio of the material surfaces may play an important role.
