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Michael H, Paim FC, Miyazaki A, Langel SN, Fischer DD, Chepngeno J, Goodman SD, Rajashekara G, Saif LJ, Vlasova AN. Escherichia coli Nissle 1917 administered as a dextranomar microsphere biofilm enhances immune responses against human rotavirus in a neonatal malnourished pig model colonized with human infant fecal microbiota. PLoS One 2021; 16:e0246193. [PMID: 33592026 PMCID: PMC7886176 DOI: 10.1371/journal.pone.0246193] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Accepted: 01/14/2021] [Indexed: 12/30/2022] Open
Abstract
Human rotavirus (HRV) is a leading cause of diarrhea in children. It causes significant morbidity and mortality, especially in low- and middle-income countries (LMICs), where HRV vaccine efficacy is low. The probiotic Escherichia coli Nissle (EcN) 1917 has been widely used in the treatment of enteric diseases in humans. However, repeated doses of EcN are required to achieve maximum beneficial effects. Administration of EcN on a microsphere biofilm could increase probiotic stability and persistence, thus maximizing health benefits without repeated administrations. Our aim was to investigate immune enhancement by the probiotic EcN adhered to a dextranomar microsphere biofilm (EcN biofilm) in a neonatal, malnourished piglet model transplanted with human infant fecal microbiota (HIFM) and infected with rotavirus. To create malnourishment, pigs were fed a reduced amount of bovine milk. Decreased HRV fecal shedding and protection from diarrhea were evident in the EcN biofilm treated piglets compared with EcN suspension and control groups. Moreover, EcN biofilm treatment enhanced natural killer cell activity in blood mononuclear cells (MNCs). Increased frequencies of activated plasmacytoid dendritic cells (pDC) in systemic and intestinal tissues and activated conventional dendritic cells (cDC) in blood and duodenum were also observed in EcN biofilm as compared with EcN suspension treated pigs. Furthermore, EcN biofilm treated pigs had increased frequencies of systemic activated and resting/memory antibody forming B cells and IgA+ B cells in the systemic tissues. Similarly, the mean numbers of systemic and intestinal HRV-specific IgA antibody secreting cells (ASCs), as well as HRV-specific IgA antibody titers in serum and small intestinal contents, were increased in the EcN biofilm treated group. In summary EcN biofilm enhanced innate and B cell immune responses after HRV infection and ameliorated diarrhea following HRV challenge in a malnourished, HIFM pig model.
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Michael H, Langel SN, Miyazaki A, Paim FC, Chepngeno J, Alhamo MA, Fischer DD, Srivastava V, Kathayat D, Deblais L, Rajashekara G, Saif LJ, Vlasova AN. Malnutrition Decreases Antibody Secreting Cell Numbers Induced by an Oral Attenuated Human Rotavirus Vaccine in a Human Infant Fecal Microbiota Transplanted Gnotobiotic Pig Model. Front Immunol 2020; 11:196. [PMID: 32117313 PMCID: PMC7033455 DOI: 10.3389/fimmu.2020.00196] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2019] [Accepted: 01/24/2020] [Indexed: 01/31/2023] Open
Abstract
Human rotavirus (HRV) is a leading cause of morbidity and mortality in children, especially in developing countries. Malnutrition is prevalent in these countries, which may contribute to the decreased oral vaccine efficacy, posing a concern for global health. Neonatal gnotobiotic (Gn) pigs closely resemble human infants in their anatomy, physiology, and outbred status and are a unique model to investigate malnutrition, oral live attenuated HRV (AttHRV) vaccination, and subsequent virulent HRV (VirHRV) challenge. We evaluated the impact of malnutrition on AttHRV vaccine efficacy and B cell immune responses in neonatal germfree (GF) or Gn pigs transplanted with human infant fecal microbiota (HIFM). Pigs were fed either deficient or sufficient bovine milk diets. Malnutrition did not significantly affect the serum and intestinal contents total or HRV-specific IgG and IgA antibody titers pre VirHRV challenge. However, HRV-specific IgG and IgA antibody secreting cells (ASCs) were reduced in blood or intestinal tissues following AttHRV vaccination and pre VirHRV challenge in deficient HIFM transplanted pigs. Furthermore, post-VirHRV challenge, deficient HIFM pigs had decreased total Ig and HRV-specific IgG and IgA antibody titers in serum or intestinal contents, in addition to decreased HRV-specific IgG and IgA ASCs in blood and ileum, compared with sufficient HIFM pigs. Our results indicate that deficient diet impairs B cell mucosal, and systemic immune responses following HRV vaccination, and challenge. The impaired immune responses contributed to the decreased protective efficacy of the AttHRV vaccine, suggesting that malnutrition may significantly reduce the effectiveness of oral HRV vaccines in children in developing countries.
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Miyazaki A, Kandasamy S, Michael H, Langel SN, Paim FC, Chepngeno J, Alhamo MA, Fischer DD, Huang HC, Srivastava V, Kathayat D, Deblais L, Rajashekara G, Saif LJ, Vlasova AN. Protein deficiency reduces efficacy of oral attenuated human rotavirus vaccine in a human infant fecal microbiota transplanted gnotobiotic pig model. Vaccine 2018; 36:6270-6281. [PMID: 30219368 PMCID: PMC6180620 DOI: 10.1016/j.vaccine.2018.09.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Revised: 08/31/2018] [Accepted: 09/05/2018] [Indexed: 12/11/2022]
Abstract
Protein deficiency impacted immunity and reduced human RV vaccine efficacy. Human infant fecal microbiota exacerbated the negative effects of protein deficiency. Immunological dysfunction could have been induced by altered tryptophan catabolism. Our findings provide an explanation for RV vaccine failures in malnourished children. Background Low efficacy of rotavirus (RV) vaccines in developing African and Asian countries, where malnutrition is prevalent, remains a major concern and a challenge for global health. Methods To understand the effects of protein malnutrition on RV vaccine efficacy, we elucidated the innate, T cell and cytokine immune responses to attenuated human RV (AttHRV) vaccine and virulent human RV (VirHRV) challenge in germ-free (GF) pigs or human infant fecal microbiota (HIFM) transplanted gnotobiotic (Gn) pigs fed protein-deficient or -sufficient bovine milk diets. We also analyzed serum levels of tryptophan (TRP), a predictor of malnutrition, and kynurenine (KYN). Results Protein-deficient pigs vaccinated with oral AttHRV vaccine had lower protection rates against diarrhea post-VirHRV challenge and significantly increased fecal virus shedding titers (HIFM transplanted but not GF pigs) compared with their protein-sufficient counterparts. Reduced vaccine efficacy in protein-deficient pigs coincided with altered serum IFN-α, TNF-α, IL-12 and IFN-γ responses to oral AttHRV vaccine and the suppression of multiple innate immune parameters and HRV-specific IFN-γ producing T cells post-challenge. In protein-deficient HIFM transplanted pigs, decreased serum KYN, but not TRP levels were observed throughout the experiment, suggesting an association between the altered TRP metabolism and immune responses. Conclusion Collectively, our findings confirm the negative effects of protein deficiency, which were exacerbated in the HIFM transplanted pigs, on innate, T cell and cytokine immune responses to HRV and on vaccine efficacy, as well as on TRP-KYN metabolism.
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Kumar A, Vlasova AN, Deblais L, Huang HC, Wijeratne A, Kandasamy S, Fischer DD, Langel SN, Paim FC, Alhamo MA, Shao L, Saif LJ, Rajashekara G. Impact of nutrition and rotavirus infection on the infant gut microbiota in a humanized pig model. BMC Gastroenterol 2018; 18:93. [PMID: 29929472 PMCID: PMC6013989 DOI: 10.1186/s12876-018-0810-2] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 05/30/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Human rotavirus (HRV) is a major cause of viral gastroenteritis in infants; particularly in developing countries where malnutrition is prevalent. Malnutrition perturbs the infant gut microbiota leading to sub-optimal functioning of the immune system and further predisposing infants to enteric infections. Therefore, we hypothesized that malnutrition exacerbates rotavirus disease severity in infants. METHODS In the present study, we used a neonatal germ free (GF) piglets transplanted with a two-month-old human infant's fecal microbiota (HIFM) on protein deficient and sufficient diets. We report the effects of malnourishment on the HRV infection and the HIFM pig microbiota in feces, intestinal and systemic tissues, using MiSeq 16S gene sequencing (V4-V5 region). RESULTS Microbiota analysis indicated that the HIFM transplantation resulted in a microbial composition in pigs similar to that of the original infant feces. This model was then used to understand the interconnections between microbiota diversity, diet, and HRV infection. Post HRV infection, HIFM pigs on the deficient diet had lower body weights, developed more severe diarrhea and increased virus shedding compared to HIFM pigs on sufficient diet. However, HRV induced diarrhea and shedding was more pronounced in non-colonized GF pigs compared to HIFM pigs on either sufficient or deficient diet, suggesting that the microbiota alone moderated HRV infection. HRV infected pigs on sufficient diet showed increased microbiota diversity in intestinal tissues; whereas, greater diversity was observed in systemic tissues of HRV infected pigs fed with deficient diet. CONCLUSIONS These results suggest that proper nourishment improves the microbiota quality in the intestines, alleviates HRV disease and lower probability of systemic translocation of potential opportunistic pathogens/pathobionts. In conclusion, our findings further support the role for microbiota and proper nutrition in limiting enteric diseases.
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Huang HC, Vlasova AN, Kumar A, Kandasamy S, Fischer DD, Deblais L, Paim FC, Langel SN, Alhamo MA, Rauf A, Shao L, Saif LJ, Rajashekara G. Effect of antibiotic, probiotic, and human rotavirus infection on colonisation dynamics of defined commensal microbiota in a gnotobiotic pig model. Benef Microbes 2017; 9:71-86. [PMID: 29022385 DOI: 10.3920/bm2016.0225] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
We developed a gnotobiotic (Gn) pig model colonised with defined commensal microbiota (DMF) to provide a simplified and controlled system to study the interactions between intestinal commensals, antibiotics (ciprofloxacin, CIP), probiotics (Escherichia coli Nissle 1917, EcN) and virulent human rotavirus (VirHRV). The DMF included seven gut commensal species of porcine origin that mimic the predominant species in the infant gut. Gn piglets were divided into four groups: DMF control (non-treated), DMF+CIP (CIP treated), DMF+CIP+EcN (CIP/EcN treated), DMF+EcN (EcN treated) and inoculated orally with 105 cfu of each DMF strain. The pig gut was successfully colonised by all DMF species and established a simplified bacterial community by post-bacteria colonisation day (PBCD) 14/post-VirHRV challenge day (PCD) 0. Overall, Bifidobacterium adolescentis was commonly observed in faeces in all groups and time points. At PCD0, after six days of CIP treatment (DMF+CIP), we observed significantly decreased aerobic and anaerobic bacteria counts especially in jejunum (P<0.001), where no DMF species were detected in jejunum by T-RFLP. Following HRV challenge, 100% of pigs in DMF+CIP group developed diarrhoea with higher diarrhoea scores and duration as compared to all other groups. However, only 33% of pigs treated with EcN plus CIP developed diarrhoea. EcN treatment also enhanced the bacterial diversity and all seven DMF species were detected with a higher proportion of Bifidobacterium longum in jejunum in the DMF+CIP+EcN group on PBCD14/PCD0. Our results suggest that EcN increased the proportion of B. longum especially in jejunum and mitigated adverse impacts of antibiotic use during acute-infectious diarrhoea. The DMF model with a simplified gut commensal community can further our knowledge of how commensals and probiotics promote intestinal homeostasis and contribute to host health.
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Kandasamy S, Vlasova AN, Fischer DD, Chattha KS, Shao L, Kumar A, Langel SN, Rauf A, Huang HC, Rajashekara G, Saif LJ. Unraveling the Differences between Gram-Positive and Gram-Negative Probiotics in Modulating Protective Immunity to Enteric Infections. Front Immunol 2017; 8:334. [PMID: 28396664 PMCID: PMC5366325 DOI: 10.3389/fimmu.2017.00334] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Accepted: 03/08/2017] [Indexed: 01/13/2023] Open
Abstract
The role of intestinal microbiota and probiotics in prevention and treatment of infectious diseases, including diarrheal diseases in children and animal models, is increasingly recognized. Intestinal commensals play a major role in development of the immune system in neonates and in shaping host immune responses to pathogens. Lactobacilli spp. and Escherichia coli Nissle 1917 are two probiotics that are commonly used in children to treat various medical conditions including human rotavirus diarrhea and inflammatory bowel disease. Although the health benefits of probiotics have been confirmed, the specific effects of these established Gram-positive (G+) and Gram-negative (G−) probiotics in modulating immunity against pathogens and disease are largely undefined. In this review, we discuss the differences between G+ and G− probiotics/commensals in modulating the dynamics of selected infectious diseases and host immunity. These probiotics modulate the pathogenesis of infectious diseases and protective immunity against pathogens in a species- and strain-specific manner. Collectively, it appears that the selected G− probiotic is more effective than the various tested G+ probiotics in enhancing protective immunity against rotavirus in the gnotobiotic piglet model.
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Paim FC, Langel SN, Fischer DD, Kandasamy S, Shao L, Alhamo MA, Huang HC, Kumar A, Rajashekara G, Saif LJ, Vlasova AN. Effects of Escherichia coli Nissle 1917 and Ciprofloxacin on small intestinal epithelial cell mRNA expression in the neonatal piglet model of human rotavirus infection. Gut Pathog 2016; 8:66. [PMID: 27999620 PMCID: PMC5154029 DOI: 10.1186/s13099-016-0148-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/12/2016] [Accepted: 12/03/2016] [Indexed: 02/08/2023] Open
Abstract
We evaluated the effects of the probiotic Escherichia coli Nissle 1917 (EcN) and the antibiotic Ciprofloxacin (Cipro) on mRNA expression of intestinal epithelial cells (IEC) in gnotobiotic (Gn) piglets colonized with a defined commensal microflora (DMF) and inoculated with human rotavirus (HRV) that infects IECs. We analyzed mRNA levels of IEC genes for enteroendocrine cells [chromogranin A (CgA)], goblet cells [mucin 2 (MUC2)], transient amplifying progenitor cell [proliferating cell nuclear antigen (PCNA)], intestinal epithelial stem cell (SOX9) and enterocytes (villin). Cipro treatment enhanced HRV diarrhea and decreased the mRNA levels of MUC2 and villin but increased PCNA. These results suggest that Cipro alters the epithelial barrier, potentially decreasing the numbers of mature enterocytes (villin) and goblet cells secreting protective mucin (MUC2). These alterations may induce increased IEC proliferation (PCNA expression) to restore the integrity of the epithelial layer. Coincidental with decreased diarrhea severity in EcN treated groups, the expression of CgA and villin was increased, while SOX9 expression was decreased representing higher epithelial integrity indicative of inhibition of cellular proliferation. Thus, EcN protects the intestinal epithelium from damage by increasing the gene expression of enterocytes and enteroendocrine cells, maintaining the absorptive function and, consequently, decreasing the severity of diarrhea in HRV infection.
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Vlasova AN, Shao L, Kandasamy S, Fischer DD, Rauf A, Langel SN, Chattha KS, Kumar A, Huang HC, Rajashekara G, Saif LJ. Escherichia coli Nissle 1917 protects gnotobiotic pigs against human rotavirus by modulating pDC and NK-cell responses. Eur J Immunol 2016; 46:2426-2437. [PMID: 27457183 DOI: 10.1002/eji.201646498] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 06/07/2016] [Accepted: 07/19/2016] [Indexed: 12/23/2022]
Abstract
Lactobacillus rhamnosus GG (LGG), a gram-positive lactic acid bacterium, is one of the most widely used probiotics; while fewer gram-negative probiotics including Escherichia coli Nissle 1917 (EcN) are characterized. A mechanistic understanding of their individual and interactive effects on human rotavirus (HRV) and immunity is lacking. In this study, noncolonized, EcN-, LGG-, and EcN + LGG-colonized neonatal gnotobiotic (Gn) pigs were challenged with HRV. EcN colonization is associated with a greater protection against HRV, and induces the highest frequencies of plasmacytoid dendritic cells (pDCs), significantly increased NK-cell function and decreased frequencies of apoptotic and TLR4+ mononuclear cells (MNCs). Consistent with the highest NK-cell activity, splenic CD172+ MNCs (DC enriched fraction) of EcN-colonized pigs produced the highest levels of IL-12 in vitro. LGG colonization has little effect on the above parameters, which are intermediate in EcN + LGG-colonized pigs, suggesting that probiotics modulate each other's effects. Additionally, in vitro EcN-treated splenic or intestinal MNCs produce higher levels of innate, immunoregulatory and immunostimulatory cytokines, IFN-α, IL-12, and IL-10, compared to MNCs of pigs treated with LGG. These results indicate that the EcN-mediated greater protection against HRV is associated with potent stimulation of the innate immune system and activation of the DC-IL-12-NK immune axis.
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Shao L, Fischer DD, Kandasamy S, Saif LJ, Vlasova AN. Tissue-specific mRNA expression profiles of porcine Toll-like receptors at different ages in germ-free and conventional pigs. Vet Immunol Immunopathol 2016; 171:7-16. [PMID: 26964712 PMCID: PMC4788813 DOI: 10.1016/j.vetimm.2016.01.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2015] [Revised: 01/25/2016] [Accepted: 01/28/2016] [Indexed: 12/31/2022]
Abstract
Toll-like receptors (TLRs), key initiators of innate immune responses, recognize antigens and are essential in linking innate and adaptive immune responses. Misrecognition and over-stimulation/expression of TLRs may contribute to the development of chronic inflammatory diseases and autoimmune diseases. However, appropriate and mature TLR responses are associated with the establishment of resistance against some infectious diseases. In this study, we assessed the mRNA expression profile of TLRs 1-10 in splenic and ileal mononuclear cells (MNCs) and dendritic cells (DCs) of germ-free (GF) and conventional pigs at different ages. We found that the TLR mRNA expression profiles were distinct between GF and conventional pigs. The expression profiles were also significantly different between splenic and ileal MNCs/DCs. Comparison of the TLR expression profiles in GF and conventional newborn and young pigs demonstrated that exposure to commensal microbiota may play a more important role than age in TLR mRNA expression profiles. To our knowledge, this is the first report that systematically assesses porcine TLRs 1-10 mRNA expression profiles in MNCs and DCs from GF and conventional pigs at different ages. These results further highlighted that the commensal microbiota of neonates play a critical role through TLR signaling in the development of systemic and mucosal immune systems.
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Hankenson FC, Garzel LM, Fischer DD, Nolan B, Hankenson KD. Evaluation of tail biopsy collection in laboratory mice (Mus musculus): vertebral ossification, DNA quantity, and acute behavioral responses. JOURNAL OF THE AMERICAN ASSOCIATION FOR LABORATORY ANIMAL SCIENCE : JAALAS 2008; 47:10-8. [PMID: 19049247 PMCID: PMC2687139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 05/28/2008] [Revised: 06/28/2008] [Accepted: 06/30/2008] [Indexed: 05/27/2023]
Abstract
A preferred method to genotype genetically engineered mice is through collection of distal tail tissue (tail biopsy) followed by DNA isolation. Currently, general or local anesthesia (or both) is recommended for biopsy after 3 wk of age, the time after which tail vertebrae are considered to be ossified. Our objective was to rigorously evaluate vertebral development, DNA content, and acute behavioral responses at different ages by harvesting tail biopsies of different lengths. We evaluated laboratory mice from 5 inbred strains and 1 outbred stock at each of 12 ages (3 to 42 d of age). Biopsies of 5-, 10-, and 15-mm lengths were obtained. Vertebrae were graded according to level of ossification by using complementary modalities of high-resolution microradiography, microcomputed tomography, and histology. Vertebral development progressed at different rates among the strains, with mature tail vertebrae containing endplates detectable in the tail of some strains by 10 d of age. Within the distal 2 mm of tail, end plates were not identified before 21 d of age. DNA yield (DNA weight/tissue weight) was greatest from the 5-mm biopsy harvest. Acute behavioral responses to biopsy varied by age and strain, and these differences were associated with vertebral maturation. Vertebral development progressed most rapidly in C57BL/6 mice, which also demonstrated the highest response rate to biopsy, whereas BALB/c mice had slower vertebral development and were less responsive. These findings support the collection of minimal lengths of tail tissue from mice at ages younger than 17 d, unless anesthesia or analgesia is provided.
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Sambucetti LC, Fischer DD, Zabludoff S, Kwon PO, Chamberlin H, Trogani N, Xu H, Cohen D. Histone deacetylase inhibition selectively alters the activity and expression of cell cycle proteins leading to specific chromatin acetylation and antiproliferative effects. J Biol Chem 1999; 274:34940-7. [PMID: 10574969 DOI: 10.1074/jbc.274.49.34940] [Citation(s) in RCA: 321] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Histone acetylation is emerging as a major regulatory mechanism thought to modulate gene expression by altering the accessibility of transcription factors to DNA. In this study, treatment of human tumor cells with the histone deacetylase inhibitor, trapoxin (TPX), resulted in selective changes in genes that control the cell cycle. TPX activated p21(waf1) transcription that led to elevated p21(waf1) protein levels in three human tumor cell lines without altering the protein levels of cdk2, cdk4, or cyclin B. In addition, TPX increased cyclin E transcription without increasing the levels of Rb, E2F, dihydrofolate reductase, or glyceraldehyde-3-phosphate dehydrogenase. The elevated levels of p21(waf1) protein led to decreased Rb phosphorylation and cdk2 activity. These effects resulted in G(1) and G(2) cell cycle arrest in H1299 human lung and MDA-MB-435 breast carcinoma cells and apoptosis in A549 lung carcinoma cells. Chromatin immunoprecipitation assays revealed that TPX increased the level of chromatin acetylation associated with histone H3 in the trapoxin-responsive region of the p21(waf1) promoter. This study demonstrates that inhibition of HDAC by TPX increases acetylation of H3-associated chromatin and alters gene expression with marked selectivity.
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Palmer IS, Fischer DD, Halverson AW, Olson OE. Identification of a major selenium excretory product in rat urine. BIOCHIMICA ET BIOPHYSICA ACTA 1969; 177:336-42. [PMID: 5769652 DOI: 10.1016/0304-4165(69)90144-5] [Citation(s) in RCA: 98] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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