Conference Presentations by francesca di cristo
Carbazole derivatives have been largely investigated in the last decades for their multifaceted b... more Carbazole derivatives have been largely investigated in the last decades for their multifaceted biological properties (antitumor, antibacterial, anti-inflammatory and neuroprotective activities); recently, it has been demonstrated that N-alkyl carbazole derivatives are able to induce the solubilization of β-amyloid peptide involved in Alzheimer pathology.[1] [2]
The aim of this work is to design and synthesize a library of N-alkyl carbazole derivates (fig.1) acting on the main target of Alzheimer's and Huntington's diseases, neurodegenerative disorders correlated to protein aggregation. Extracellular plaque deposits of the β-amyloid peptide (Aβ-peptide), reduced synthesis of the neurotransmitter acetylcholine, hyper-phosphorylation of Tau protein are neuropathological hallmarks of Alzheimer’s disease. [3] Huntington's disease is caused by an autosomal dominant mutation in the IT15 gene, which consists of an expansion of CAG on chromosome 4, resulting in the formation of inclusion bodies in both nuclear and cytosolic region.[4]
The synthesized compounds were characterized and underwent to cell-based analyses in order to evaluate their biological activity in vitro on normal cell line (NIH-3T3, mouse embryonic fibroblast): the results of our investigations are shown in graphs (fig. 2). It will be also evaluated the potential Acetylcholinesterase (AChE) inhibitory activity of synthetized compounds, trough Spectrometric method by Ellman and their effects on artificial phospholipid membranes, trough liposome containing carboxyfluorescein.
Moreover, in order to evaluate the effect of compounds on the inclusion bodies solubility, experimental procedures will be setup in striatal murine cell model of Huntington’s disease STHdhQ7 / 7 line expressing the Huntingtin wild-type gene, and STHdhQ109 /109 line expressing the mutated gene
Negli ultimi anni, la ricerca odontostomatologica ha focalizzato la propria attenzione sullo svil... more Negli ultimi anni, la ricerca odontostomatologica ha focalizzato la propria attenzione sullo sviluppo di resine restaurative con proprietà antibatteriche. Ciò è dimostrato dall’ ampia commercializzazione di compositi dentali contenenti ioni inorganici ad azione antimicrobica 1. Ciononostante, è necessario un ulteriore sviluppo di questo tipo di materiali in quanto la placca batterica dentale, il principale responsabile delle carie secondarie che seguono la restaurazione dentale, è presente come biofilm, ovvero un aggregato di cellule microbiche associate ad una superficie ed incluse in una matrice polimerica extracellulare da esse prodotta. In particolare, la natura della struttura del biofilm e le caratteristiche fisiologiche degli organismi che lo popolano conferiscono una resistenza agli agenti antimicrobici dovuta a strategie multicellulari e/o alla capacità delle singole cellule di differenziarsi in uno stato fenotipico tollerante l’azione antibiotica 2. Con questi presupposti, risulta necessario lo sviluppo di compositi in grado di contrastare la formazione di questa organizzazione. Viene quindi riportata l’incorporazione dell’ammonio quaternario metacrilato all’ interno di resine dentali con lo scopo di ottenere un nuovo materiale composito con attività antibiofilm.
The neuropathological hallmarks of Alzheimer disease include abundant deposits of amyloid β (Aβ) ... more The neuropathological hallmarks of Alzheimer disease include abundant deposits of amyloid β (Aβ) peptides organized in senile plaques, accumulation of hyperphosphorylated tau protein in neurofibrillary tangles, and extensive neuronal degeneration and loss. 1 Besides, cholinergic abnormalities have been observed in AD as, for instance, a reduction in acetylcholine receptor levels or dysfunctions of cholinergic signal transmission, which are of critical importance in brain areas involved in learning, memory, and emotional responses. 2 For this reason, we have synthesized a library of carbazole derivatives here investigated in silico and in vitro for their ability to prevent the aggregation of Aβ peptides. The synthesized compounds were underwent to molecular docking simulation and cell-based analyses in order to verify their potential interfering activity on Aβ aggregation. All together, the obtained results indicate that the two most promising compounds in docking simulations also exhibited the higher activity in vitro. Other studies are ongoing for a better understanding of the underlying mechanism by which the molecules act in our cell-based system.
The design of new metal complexes as anticancer agents has received considerable interest in rece... more The design of new metal complexes as anticancer agents has received considerable interest in recent years. Carbenic complexes of gold, silver and copper showed significant biological activity, and have progressed into clinical trials. 1-4 The researches on N-heterocyclic carbene groups (NHC) started with the synthesis of the first stable NHC by Arduengo: 1,3-bis(adamatil)-imidazol-2-ylidene. 5 The ease of synthesis of these molecules and the possibility of coordinating the transition metals with consequent formation of metal complexes NHC, justify broad use both in the catalysis and biological field. The objective of this project was to synthesize new complexes of silver and gold and copper having NHC ligands in order to test their potential pharmacological activity. The ligands were choice in order to obtain complexes with different lipophilicity and thus evaluate their pharmacological effect. 6 Indeed, the lipophilic cation delocalized can pass through biological membranes very quickly and it can concentrate mainly in the mitochondria of cancer cells. NHC-ligand lipophilicity can be increased replacing the hydrogens in positions 4 and 5 of the imidazole ring, or functionalizing the nitrogen atoms with lipophilic substituents. Objective of the work was the changes to the positions 4 and 5 of the imidazole ring. The synthesis of new carbenic ligands (N-methyl-N'-[2-hydroxycyclopentan]-4,5-dychloroimydazole iodide, N-methyl-N'-[2-hydroxycyclopentan]-4,5-dyphenylimydazole iodide, N-methyl-N'-[(2-hydroxy-2-phenyl)ethyl]-imydazole iodide) and 8 new complexes of gold, silver and copper was carried out. The complexes were tested on MCF-7 (human mammary carcinoma expressing the estrogen receptor ERα/ER-positive), MDA-MB-231 (human mammary carcinoma not expressing the estrogen receptor/ER-negative), MCF-10 (breast glandular epithelium), using MTT test with standard procedures. All the molecules showed a good inhibitory effect on the proliferation of two cancer cell lines. Many of them did not showed any inhibitory effect on healthy cell. Instead, some compounds showed a only a mild effects at very high concentrations. Then, it was investigated if the antiproliferative activity of the complex AuL20 on MCF-7 was connected to the mechanisms of regulation of the cell cycle. Therefore, it was evaluated the level of expression of two proteins involved in the regulation of the cell cycle, p53 and p21 with immunoblotting, using β-actina as " loading control ". Results showed a marked modulation of the expression of p21 and p53, confirming that AuL20 can stop cell proliferation between the G1 and S phase.
Huntington’s disease (HD) is a genetic neurodegenerative disorder caused by an expanded CAG repea... more Huntington’s disease (HD) is a genetic neurodegenerative disorder caused by an expanded CAG repeat in the huntingtin gene, which encodes an abnormally long polyglutamine repeat (polyQ) in the huntingtin protein (HTT). HD is inherited in an autosomal dominant manner, with age-dependent penetrance. Clinically, the disease is characterized by progressive motor dysfunction, cognitive decline, and psychiatric disturbances.1
It is widely accepted the involvement of mitochondrial dysfunctions and bioenergetic defects in HD and neurodegenerative diseases in general.2 The aim of this work is to investigate the effects of the fatty acid β-oxidation inhibitor Etomoxir on in vitro and in vivo model of HD. This compound interferes with mitochondria by irreversible inhibition of carnitine palmitoyltransferase-1 (CPT-1), the enzyme that catalyzes the first step in long-chain fatty acid import into mitochondria.3
In order to study the biological activity in vitro, Etomoxir was tested on mouse embryonic fibroblast cell line (NIH 3T3) and on striatal murine cell lines expressing HTT wild-type (STHdhQ7/7) and HTT mutated gene (STHdhQ109/109). Subsequently, it was evaluated the ability of Etomoxir to interfere with polyQ expression in STHdhQ109/109 cell line, following a 72h treatment. Finally it was investigated the effect of Etomoxir on neuronal dysfunctions induced by mutant polyQ in transgenic C.elegans (fig.3). In such strain were expressed the first 57 aminoacids of human HTT containing expanded polyQ fused to fluorescent marker proteins in the six mechanosensory neurons. The increased polyQ expansion leads to a significant mechanosensory defective (Mec) phenotype in this strain.4
Our data showed that Etomoxir didn’t interfere with fibroblastic and neuronal proliferation, it was able to decrease PolyQ expression in HD cellular model and it rescued mechanosensorial dysfunction phenotypes induced by mutant polyQ in transgenic C.elegans.
Chemotherapics used in cancer treatment elicit pleiotropic effects interfering, for instance, dir... more Chemotherapics used in cancer treatment elicit pleiotropic effects interfering, for instance, directly on DNA metabolism or endoplasmic organelles functions. DNA has been a remarkable bioreceptor for a large number of molecules still remaining one of the major biological target for the design of anticancer agents. Amongst them, carbazole derivatives represent an important and heterogeneous class of anticancer agents, which have been reported not only to intercalate DNA but also to inhibit telomerase and topoisomerase activity and regulate protein phosphorylation. These compounds drew a growing interest over the last two decades and a few representatives as, for instance, ellipticine [5,11-dimethyl-6H-pyrido(4,3-b)carbazole] and rebeccamycin [1,11-dichloro-12-(4-O-methyl-β-D-glucopyranosyl)-12,13-dihydro-5H-indolo[2,3-a]pyrrolo[3,4-c]carbazole-5,7(6H)-dione], two naturally occurring carbazole alkaloids displaying DNA intercalative antitumor activity, have been effective for the treatment of cancer. Starting from ellipticine, many analogues have been synthesized and tested for their antitumor activity, showing satisfactory results in several cancer type and, most importantly, in metastatic breast cancer. Ellipticine and its derivatives are able to trigger a variety of biological responses caused by the interaction with specific cellular compartments, as nucleus, mitochondrion and endoplasmic reticulum. Because of their polycyclic, planar and aromatic structure, carbazoles activity is strictly related to their ability to intercalate DNA, which remains one of the main targets for cytotoxic carbazoles. However, carbazole derivatives showed also the ability to interfere with DNA-dependent enzymes, as topoisomerases I/II and telomerase, or against other targets such as cyclin-dependent kinases and estrogen receptors. Out of all the carbazole derivatives tested for their cytotoxic activity, only some have entered clinical trials and only very few have been approved for the treatment of cancer so far, because of the occurrence of severe side effects or multidrug resistance. Herein we report the design and the synthesis of new series of N-alkylamino carbazole derivatives. These compounds have been prepared following a procedure recently optimized in our laboratories. We also examined the effects of these compounds on cell proliferation against estrogen receptor positive (ER+) MCF-7 and estrogen receptor negative (ER-) MDA-MB-231 human breast cancer cell line at different concentration using the MTT assay. We found that one of them significantly reduced cell proliferation in both breast cancer cells line, whereas others compounds did not show considerable negative effects. The inhibitory effect elicited by this compound on triple negative breast cancer cell line (MDA-MB-231), unresponsive to anti-estrogens, could open new perspectives for novel pharmacological approaches in breast cancer therapy. Powered by TCPDF (www.tcpdf.org)
Recently group III and IV metal complexes have been revaluated as antitumor therapy drugs. Many c... more Recently group III and IV metal complexes have been revaluated as antitumor therapy drugs. Many complexes of titanium and lanthanides showed significant biological activity and progressed into clinical trials. [1-4] Because of these good biological results, we decided to synthesized structural analogs of titanocenes with group III metal. In this regard, we synthesized novel scandium, yttrium and neodymium complexes. We tested complexes on DU146 (Prostatic carcinoma) and MDA. MB213 (Breast cancer) to verify if they could inhibite tumor cell-growth. Measurement of cell-line viability was evaluated toward MTT test following standard procedures. The reduction in growth showed a concentration-dependent activity on both cell lines even at a 5 μm concentration. So, most of complexes demonstrated an effective ability of inhibiting the tumor cell growth, referring to antiblastic activity.
Papers by francesca di cristo
Natural polyphenols are valuable compounds present in plants, fruits, legumes, chocolate, tea, wi... more Natural polyphenols are valuable compounds present in plants, fruits, legumes, chocolate, tea, wine and marine organisms possessing scavenging properties towards radical oxygen species. These abilities make polyphenols interesting either for the treatment of various diseases like inflammation and cancer or for anti-ageing purposes in cosmetic formulations. Unfortunately, such compounds lack in long-term stability, are very sensitive to light, and often present a low water solubility and poor bioavailability. To overcome these limitations and enhance polyphenols therapeutic applications, nanotechnology-based delivery systems have been developed, and among all, nanoencapsulation represented a promising strategy. This review described a recent overview of physicochemical nanoencapsulated polyphenols focusing on the most representative molecules such as resveratrol, quercetin, epigallocatechin-3-gallate, and curcumin
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Conference Presentations by francesca di cristo
The aim of this work is to design and synthesize a library of N-alkyl carbazole derivates (fig.1) acting on the main target of Alzheimer's and Huntington's diseases, neurodegenerative disorders correlated to protein aggregation. Extracellular plaque deposits of the β-amyloid peptide (Aβ-peptide), reduced synthesis of the neurotransmitter acetylcholine, hyper-phosphorylation of Tau protein are neuropathological hallmarks of Alzheimer’s disease. [3] Huntington's disease is caused by an autosomal dominant mutation in the IT15 gene, which consists of an expansion of CAG on chromosome 4, resulting in the formation of inclusion bodies in both nuclear and cytosolic region.[4]
The synthesized compounds were characterized and underwent to cell-based analyses in order to evaluate their biological activity in vitro on normal cell line (NIH-3T3, mouse embryonic fibroblast): the results of our investigations are shown in graphs (fig. 2). It will be also evaluated the potential Acetylcholinesterase (AChE) inhibitory activity of synthetized compounds, trough Spectrometric method by Ellman and their effects on artificial phospholipid membranes, trough liposome containing carboxyfluorescein.
Moreover, in order to evaluate the effect of compounds on the inclusion bodies solubility, experimental procedures will be setup in striatal murine cell model of Huntington’s disease STHdhQ7 / 7 line expressing the Huntingtin wild-type gene, and STHdhQ109 /109 line expressing the mutated gene
It is widely accepted the involvement of mitochondrial dysfunctions and bioenergetic defects in HD and neurodegenerative diseases in general.2 The aim of this work is to investigate the effects of the fatty acid β-oxidation inhibitor Etomoxir on in vitro and in vivo model of HD. This compound interferes with mitochondria by irreversible inhibition of carnitine palmitoyltransferase-1 (CPT-1), the enzyme that catalyzes the first step in long-chain fatty acid import into mitochondria.3
In order to study the biological activity in vitro, Etomoxir was tested on mouse embryonic fibroblast cell line (NIH 3T3) and on striatal murine cell lines expressing HTT wild-type (STHdhQ7/7) and HTT mutated gene (STHdhQ109/109). Subsequently, it was evaluated the ability of Etomoxir to interfere with polyQ expression in STHdhQ109/109 cell line, following a 72h treatment. Finally it was investigated the effect of Etomoxir on neuronal dysfunctions induced by mutant polyQ in transgenic C.elegans (fig.3). In such strain were expressed the first 57 aminoacids of human HTT containing expanded polyQ fused to fluorescent marker proteins in the six mechanosensory neurons. The increased polyQ expansion leads to a significant mechanosensory defective (Mec) phenotype in this strain.4
Our data showed that Etomoxir didn’t interfere with fibroblastic and neuronal proliferation, it was able to decrease PolyQ expression in HD cellular model and it rescued mechanosensorial dysfunction phenotypes induced by mutant polyQ in transgenic C.elegans.
Papers by francesca di cristo
The aim of this work is to design and synthesize a library of N-alkyl carbazole derivates (fig.1) acting on the main target of Alzheimer's and Huntington's diseases, neurodegenerative disorders correlated to protein aggregation. Extracellular plaque deposits of the β-amyloid peptide (Aβ-peptide), reduced synthesis of the neurotransmitter acetylcholine, hyper-phosphorylation of Tau protein are neuropathological hallmarks of Alzheimer’s disease. [3] Huntington's disease is caused by an autosomal dominant mutation in the IT15 gene, which consists of an expansion of CAG on chromosome 4, resulting in the formation of inclusion bodies in both nuclear and cytosolic region.[4]
The synthesized compounds were characterized and underwent to cell-based analyses in order to evaluate their biological activity in vitro on normal cell line (NIH-3T3, mouse embryonic fibroblast): the results of our investigations are shown in graphs (fig. 2). It will be also evaluated the potential Acetylcholinesterase (AChE) inhibitory activity of synthetized compounds, trough Spectrometric method by Ellman and their effects on artificial phospholipid membranes, trough liposome containing carboxyfluorescein.
Moreover, in order to evaluate the effect of compounds on the inclusion bodies solubility, experimental procedures will be setup in striatal murine cell model of Huntington’s disease STHdhQ7 / 7 line expressing the Huntingtin wild-type gene, and STHdhQ109 /109 line expressing the mutated gene
It is widely accepted the involvement of mitochondrial dysfunctions and bioenergetic defects in HD and neurodegenerative diseases in general.2 The aim of this work is to investigate the effects of the fatty acid β-oxidation inhibitor Etomoxir on in vitro and in vivo model of HD. This compound interferes with mitochondria by irreversible inhibition of carnitine palmitoyltransferase-1 (CPT-1), the enzyme that catalyzes the first step in long-chain fatty acid import into mitochondria.3
In order to study the biological activity in vitro, Etomoxir was tested on mouse embryonic fibroblast cell line (NIH 3T3) and on striatal murine cell lines expressing HTT wild-type (STHdhQ7/7) and HTT mutated gene (STHdhQ109/109). Subsequently, it was evaluated the ability of Etomoxir to interfere with polyQ expression in STHdhQ109/109 cell line, following a 72h treatment. Finally it was investigated the effect of Etomoxir on neuronal dysfunctions induced by mutant polyQ in transgenic C.elegans (fig.3). In such strain were expressed the first 57 aminoacids of human HTT containing expanded polyQ fused to fluorescent marker proteins in the six mechanosensory neurons. The increased polyQ expansion leads to a significant mechanosensory defective (Mec) phenotype in this strain.4
Our data showed that Etomoxir didn’t interfere with fibroblastic and neuronal proliferation, it was able to decrease PolyQ expression in HD cellular model and it rescued mechanosensorial dysfunction phenotypes induced by mutant polyQ in transgenic C.elegans.