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Pelepenko LE, Marciano MA, Shelton RM, Camilleri J. Leaching and cytotoxicity of bismuth oxide in ProRoot MTA - A laboratory investigation. Int Endod J 2024. [PMID: 38804676 DOI: 10.1111/iej.14101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 05/10/2024] [Accepted: 05/12/2024] [Indexed: 05/29/2024]
Abstract
AIM The present study examined the leaching and cytotoxicity of bismuth from ProRoot MTA and aimed to identify whether bismuth leaching was affected by the cement base and the immersion regime used. METHODOLOGY The leaching profile of bismuth was examined from ProRoot MTA and compared with hydroxyapatite containing 20% bismuth oxide as well as hydroxyapatite and tricalcium silicate to investigate whether bismuth release changed depending on the cement base. Bismuth leaching was determined after 30 and 180 days of ageing immersed in Dulbecco's modified Eagle's medium (DMEM) using mass spectroscopy (ICP-MS). The media were either unchanged or regularly replenished. The pH, surface microstructure and phase changes of aged materials were assessed. Wistar rat femoral bone marrow stromal cells (BMSCs) and cutaneous fibroblasts were isolated, cultured and seeded for cell counting (trypan blue live/dead) after exposure to non-aged, 30- and 180-days-aged samples in regularly replenished DMEM. Aged DMEM in contact with materials was also used to culture BMSCs to investigate the effect of material leachates on the cells. Gene expression analysis was also carried out after direct exposure of cells to non-aged materials. Differences between groups were statistically tested at a significance level of 5%. RESULTS All materials exhibited alterations after immersion in DMEM and this increased with longer exposure times. The bismuth leached from ProRoot MTA as detected by ICP-MS. Aged ProRoot MTA samples exhibited a black discolouration and surface calcium carbonate deposition. ProRoot MTA influenced cell counts after direct exposure and its 180-days leachates reduced BMSC viability. After direct BMSC contact with non-aged ProRoot MTA an upregulation of metallothionein (MT1 and MT2A) expression and down-regulation of collagen-1a (Col-1a) and bone sialoprotein (BSP) expression was identified. CONCLUSIONS Bismuth leaching was observed throughout 180-days observation period from all materials containing bismuth oxide. This negatively influenced cell viability and gene expression associated with bismuth exposure. This is the first study to report that metallothionein gene expression was influenced by exposure to ProRoot MTA.
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Affiliation(s)
- Lauter E Pelepenko
- Department of Restorative Dentistry, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, Brazil
| | - Marina A Marciano
- Department of Restorative Dentistry, School of Dentistry of Piracicaba, State University of Campinas, Piracicaba, Brazil
| | - Richard M Shelton
- College of Medical Sciences, Dental School, University of Birmingham, Birmingham, UK
| | - Josette Camilleri
- College of Medical Sciences, Dental School, University of Birmingham, Birmingham, UK
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Collins JE, Lee JW, Bohmer MJ, Welden JD, Arshadi AK, Du L, Cichewicz RH, Chakrabarti D. Cyclic Tetrapeptide HDAC Inhibitors with Improved Plasmodium falciparum Selectivity and Killing Profile. ACS Infect Dis 2021; 7:2889-2903. [PMID: 34491031 DOI: 10.1021/acsinfecdis.1c00341] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Cyclic tetrapeptide histone deacetylase inhibitors represent a promising class of antiplasmodial agents that epigenetically disrupt a wide range of cellular processes in Plasmodium falciparum. Unfortunately, certain limitations, including reversible killing effects and host cell toxicity, prevented these inhibitors from further development and clinical use as antimalarials. In this study, we present a series of cyclic tetrapeptide analogues derived primarily from the fungus Wardomyces dimerus that inhibit P. falciparum with low nanomolar potency and high selectivity. This cyclic tetrapeptide scaffold was diversified further via semisynthesis, leading to the identification of several key structural changes that positively impacted the selectivity, potency, and in vitro killing profiles of these compounds. We confirmed their effectiveness as HDAC inhibitors through the inhibition of PfHDAC1 catalytic activity, in silico modeling, and the hyperacetylation of histone H4. Additional analysis revealed the in vitro inhibition of the most active epoxide-containing analogue was plasmodistatic, exhibiting reversible inhibitory effects upon compound withdrawal after 24 or 48 h. In contrast, one of the new diacetyloxy semisynthetic analogues, CTP-NPDG 19, displayed a rapid and irreversible action against the parasite following compound exposure for 24 h.
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Affiliation(s)
- Jennifer E. Collins
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States
| | - Jin Woo Lee
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Monica J. Bohmer
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States
| | - Joshua D. Welden
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States
| | - Arash K. Arshadi
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States
| | - Lin Du
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Robert H. Cichewicz
- Department of Chemistry and Biochemistry, Institute for Natural Products Applications & Research Technologies, University of Oklahoma, 101 Stephenson Parkway, Norman, Oklahoma 73019, United States
| | - Debopam Chakrabarti
- Division of Molecular Microbiology, Burnett School of Biomedical Sciences, University of Central Florida, 12722 Research Parkway, Orlando, Florida 32826, United States
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Monetti C, Bernardini G, Vigetti D, Prati M, Fortaner S, Sabbioni E, Gornati R. Platinum toxicity and gene expression in Xenopus embryos: analysis by FETAX and differential display. Altern Lab Anim 2005; 31:401-8. [PMID: 15601245 DOI: 10.1177/026119290303100406] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Since the level of platinum in the environment is destined to increase, because of its use in vehicle catalytic converters, the toxicity of platinum needs further investigation. In this study, the frog embryo teratogenesis assay-Xenopus (FETAX) was used to compare the embryotoxicity and teratogenicity of two common platinum species, (NH4)2PtCl4 and (NH4)2PtCl6. The uptake rates of the two platinum species were studied, and also their effects on the expression of genes encoding metallothionein and heat-shock protein 70, which are known to be induced by several stress factors. In addition, the differential display technique was used to search for genes that were specifically induced by platinum. A gene for the type I collagen alpha-chain and a novel gene were identified.
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Affiliation(s)
- Claudio Monetti
- Department of Structural and Functional Biology, Università dell'Insubria, 3 Via Dunant, 21100 Varese, Italy
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Li Z, Wang X, Yu RYL, Ding BB, Yu JJ, Dai XM, Naganuma A, Stanley ER, Ye BH. BCL-6 negatively regulates expression of the NF-kappaB1 p105/p50 subunit. THE JOURNAL OF IMMUNOLOGY 2005; 174:205-14. [PMID: 15611242 DOI: 10.4049/jimmunol.174.1.205] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BCL-6 is a transcription repressor frequently deregulated in non-Hodgkin's B cell lymphomas. Its activity is also critical to germinal center development and balanced Th1/Th2 differentiation. Previous studies have suggested that NF-kappaB activity is suppressed in germinal center and lymphoma B cells that express high levels of BCL-6, and yet the reason for this is unknown. We report in this study that BCL-6 can bind to three sequence motifs in the 5' regulatory region of NF-kappaB1 in vitro and in vivo, and repress NF-kappaB1 transcription both in reporter assays and in lymphoma B cell lines. BCL-6(-/-) mice further confirm the biological relevance of BCL-6-dependent regulation of NF-kappaB1 because BCL-6 inactivation caused notable increase in p105/p50 proteins in several cell types. Among these, BCL-6(-/-) macrophage cell lines displayed a hyperproliferation phenotype that can be reversed by NF-kappaB inhibitors, e.g., N-tosyl-l-phenylalanine chloromethyl ketone and SN50, a result that is consistent with increased nuclear kappaB-binding activity of p50 homodimer and p50/p65 heterodimer. Our results demonstrate that BCL-6 can negatively regulate NF-kappaB1 expression, thereby inhibiting NF-kappaB-mediated cellular functions.
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Affiliation(s)
- Zhiping Li
- Department of Cell Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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Wang X, Li Z, Naganuma A, Ye BH. Negative autoregulation of BCL-6 is bypassed by genetic alterations in diffuse large B cell lymphomas. Proc Natl Acad Sci U S A 2002; 99:15018-23. [PMID: 12407182 PMCID: PMC137537 DOI: 10.1073/pnas.232581199] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Thirty to forty percent of diffuse large B cell lymphomas (DLBCL) carry BCL-6 translocations that disrupt its 5' regulatory region. This same region is also subject to somatic hypermutations, although only a small fraction of these mutations have a detectable effect on transcription. Here, we show that transcription of the BCL-6 gene is negatively self-regulated in multiple cell types. This mechanism operates by means of the interaction of two BCL-6-binding sites within exon 1 of the gene and the BCL-6 protein itself, which is a potent transcription repressor. Because the DLBCL-associated "activating mutations" specifically target these exon 1 binding sites, and because the entire exon 1 is usually removed in the BCL-6-translocated tumors, this autoregulation is bypassed in 30-40% of all DLBCL cases. Our results not only demonstrate an important mechanism governing the expression of BCL-6, but also explain how BCL-6 is deregulated in a large number of DLBCL patients, providing a better understanding of BCL-6-related lymphomagenesis.
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Affiliation(s)
- Xing Wang
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, NY 10461, USA
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