Search tips
Search criteria

Results 1-8 (8)

Clipboard (0)

Select a Filter Below

Year of Publication
Document Types
1.  In Utero Growth Restriction and Catch-up Adipogenesis After Developmental Di (2-ethylhexyl) Phthalate (DEHP) Exposure Cause Glucose Intolerance in Adult Male Rats Following a High-fat Dietary Challenge 
Phthalates impact adipocyte morphology in vitro, but the sex-specific adipogenic signature immediately after perinatal di(2-ethylhexyl) phthalate (DEHP) exposure and adulthood physiology following a high-fat (HF) dietary challenge are unknown. In the current study, pregnant and lactating dams received DEHP (300 mg/kg body weight) or oil. At weaning (postnatal day (PND) 21), adipose tissue was sampled for real-time PCR. The remaining offspring consumed a control or HF diet. DEHP decreased % fat in males at birth from 13.9%±0.2 to 11.8%±0.6 (mean±SEM), representing a 15.1% decrease in fat by DEHP, and these males caught up in adiposity to controls by PND21. Adult DEHP-exposed males had a 27.5% increase in fat (12.5%±0.9% in controls vs. 15.9%±1.5% in the DEHP group); adipocyte perimeter was increased as well, with fewer small/medium-sized adipocytes, and decreased cell number compared to oil controls. HF diet intake in DEHP-exposed males further increased male energy intake and body weight and led to glucose intolerance. In PND21 males, DEHP increased the expression of adipogenic markers (Pparg1, Cebpa, Adipoq, Ppard, Fabp4, Fasn, Igf1), decreased Lep, and decreased markers of mesenchymal stem cell commitment to the adipogenic lineage (Bmp2, Bmp4, Stat1, Stat5a) compared to oil controls. These data suggest that DEHP may decrease the adipocyte pool at birth, which initially increases adaptive adipocyte maturation and lipid accumulation, but leads to adipose tissue dysfunction in adulthood, decreasing the capacity to adapt to a HF diet, and leading to systemic glucose intolerance.
PMCID: PMC4631689  PMID: 26188368
adipose; phthalates; diabetes; Pparg; obesity; programming
2.  Developmental Bisphenol A (BPA) Exposure Leads to Sex-specific Modification of Hepatic Gene Expression and Epigenome at Birth that May Exacerbate High-fat Diet-induced Hepatic Steatosis 
Toxicology and applied pharmacology  2015;284(2):101-112.
Developmental bisphenol A (BPA) exposure increases adulthood hepatic steatosis with reduced mitochondrial function. To investigate potential epigenetic mechanisms behind developmental BPA-induced hepatic steatosis, pregnant Sprague-Dawley rats were dosed with vehicle (oil) or BPA (100 μg/kg/day) from gestational day 6 until postnatal day (PND) 21. After weaning, offspring were either challenged with a high-fat (HF; 45% fat) or remained on a control (C) diet until PND110. From PND60 to 90, both BPA and HF diet increased the fat/lean ratio in males only, and the combination of BPA and HF diet appeared to cause the highest ratio. On PND110, Oil-HF, BPA-C, and BPA-HF males had higher hepatic lipid accumulation than Oil-C, with microvesicular steatosis being marked in the BPA-HF group. Furthermore, on PND1, BPA increased and modified hepatic triglycerides (TG) and free fatty acid (FFA) composition in males only. In PND1 males, BPA increased hepatic expression of FFA uptake gene Fat/Cd36, and decreased the expression of TG synthesis- and β-oxidation-related genes (Dgat, Agpat6, Cebpα, Cebpβ, Pck1, Acox1, Cpt1a, Cybb). BPA altered DNA methylation, histone marks (H3Ac, H4Ac, H3Me2K4, H3Me3K36), and decreased the binding of several transcription factors (Pol II, C/EBPβ, SREBP1) within the male Cpt1a gene, the key β-oxidation enzyme. In PND1 females, BPA only increased the expression of genes involved in FFA uptake and TG synthesis (Lpl, Fasn, and Dgat). These data suggest that developmental BPA exposure alters and reprograms hepatic β-oxidation capacity in males, potentially thorough the epigenetic regulation of genes, and further alters the response to a HF diet.
PMCID: PMC4520316  PMID: 25748669
Bisphenol A (BPA); adiposity; endocrine disrupting chemical (EDC); NAFLD; methylation; histones
3.  Redox-Responsive Self-Assembled Chain-Shattering Polymeric Therapeutics 
Biomaterials science  2015;3(7):1061-1065.
We report the design and development of redox-responsive chain-shattering polymeric therapeutics (CSPTs). CSPTs were synthesized by condensation polymerization and further modified with poly(ethylene glycol) (PEG) via “Click” reaction. Size-controlled CSPT nanoparticles (NPs) were formed through nanoprecipitation with high drug loading (up to 18%); the particle size increased in a concentration dependent manner. Drug release from particles was well controlled over 48 h upon redox triggering. The anticancer efficacy of the CSPT NPs was validated both in vitro and in vivo.
PMCID: PMC4486357  PMID: 26146551
4.  Aptamer-Functionalized, Ultra-Small, Monodisperse Silica Nanoconjugates for Targeted Dual-Mode Imaging of Lymph Nodes with Metastatic Tumors** 
PMCID: PMC4486261  PMID: 23136130
silica nanoparticle; nanoconjugate; dual-modal imaging; metastasis targeting; sentinel lymph node; aptamer; breast cancer
5.  Deoxynybomycins inhibit mutant DNA gyrase and rescue mice infected with fluoroquinolone-resistant bacteria 
Nature Communications  2015;6:6947.
Fluoroquinolones are one of the most commonly prescribed classes of antibiotics, but fluoroquinolone resistance (FQR) is widespread and increasing. Deoxynybomycin (DNM) is a natural-product antibiotic with an unusual mechanism of action, inhibiting the mutant DNA gyrase that confers FQR. Unfortunately, isolation of DNM is difficult and DNM is insoluble in aqueous solutions, making it a poor candidate for development. Here we describe a facile chemical route to produce DNM and its derivatives. These compounds possess excellent activity against FQR methicillin-resistant Staphylococcus aureus and vancomycin-resistant Enterococci clinical isolates and inhibit mutant DNA gyrase in-vitro. Bacteria that develop resistance to DNM are re-sensitized to fluoroquinolones, suggesting that resistance that emerges to DNM would be treatable. Using a DNM derivative, the first in-vivo efficacy of the nybomycin class is demonstrated in a mouse infection model. Overall, the data presented suggest the promise of DNM derivatives for the treatment of FQR infections.
Fluoroquinolone antibiotics are widely used to treat serious bacterial infections, but resistance is an increasing problem. Here the authors describe the synthesis and characterization of novel deoxynybomycin derivatives that exhibit activity against fluoroquinolone-resistant infections in an in vivo model.
PMCID: PMC4421842  PMID: 25907309
6.  Genistein Exposure During the Early Postnatal Period Favors the Development of Obesity in Female, But Not Male Rats 
Toxicological Sciences  2013;138(1):161-174.
Genistein (Gen), the primary isoflavone in soy, has been shown to adversely affect various endocrine-mediated endpoints in rodents and humans. Soy formula intake by human infants has been associated with early age at menarche and decreased female-typical behavior in girls. Adipose deposition and expansion are also hormonally regulated and Gen has been shown to alter these processes. However, little is known about the impact of early-life soy intake on metabolic homeostasis in adulthood. The current study examined the impact of early-life Gen exposure on adulthood body composition (by magnetic resonance imaging) and the molecular signals mediating adipose expansion. From postnatal day (PND) 1 to 22, rat pups were daily orally dosed with 50mg/kg Gen to mimic blood Gen levels in human infants fed soy formula. Female but not male Gen-exposed rats had increased fat/lean mass ratio, fat mass, adipocyte size and number, and decreased muscle fiber perimeter. PND22 Gen-exposed females, but not males, had increased expression of adipogenic factors, including CCAAT/enhancer binding protein alpha (Cebpα), CCAAT/enhancer binding protein beta (Cebpβ), and peroxisome proliferator-activated receptor gamma (Pparγ). Furthermore, Wingless-related MMTV integration site 10b (Wnt10b), a critical regulator of adipogenic cell fate determination, was hypermethylated and had decreased expression in adipose of PND22 Gen-exposed females. These data suggest that developmental Gen exposure in rats has gender-specific effects on adiposity that closely parallel the effects of a postweaning high-fat diet and underscore the importance of considering timing of exposure and gender when establishing safety recommendations for early-life dietary Gen intake.
PMCID: PMC3930366  PMID: 24361872
adipogenesis; body composition; genistein; methylation; obesity; soy infant formula.
7.  Is the presence of abnormal prion protein in the renal glomeruli of feline species presenting with FSE authentic? 
In a recent paper written by Hilbe et al (BMC vet res, 2009), the nature and specificity of the prion protein deposition in the kidney of feline species affected with feline spongiform encephalopathy (FSE) were clearly considered doubtful. This article was brought to our attention because we published several years ago an immunodetection of abnormal prion protein in the kidney of a cheetah affected with FSE. At this time we were convinced of its specificity but without having all the possibilities to demonstrate it. As previously published by another group, the presence of abnormal prion protein in some renal glomeruli in domestic cats affected with FSE is indeed generally considered as doubtful mainly because of low intensity detected in this organ and because control kidneys from safe animals present also a weak prion immunolabelling. Here we come back on these studies and thought it would be helpful to relay our last data to the readers of BMC Vet res for future reference on this subject.
Here we come back on our material as it is possible to study and demonstrate the specificity of prion immunodetection using the PET-Blot method (Paraffin Embedded Tissue - Blot). It is admitted that this method allows detecting the Proteinase K (PK) resistant form of the abnormal prion protein (PrPres) without any confusion with unspecific immunoreaction. We re-analysed the kidney tissue versus adrenal gland and brain samples from the same cheetah affected with TSE using this PET-Blot method. The PET-Blot analysis revealed specific PrPres detection within the brain, adrenal gland and some glomeruli of the kidney, with a complete identicalness compared to our previous detection using immunohistochemistry. In conclusion, these new data enable us to confirm with assurance the presence of specific abnormal prion protein in the adrenal gland and in the kidney of the cheetah affected with FSE. It also emphasizes the usefulness for the re-examination of any available tissue blocks with the PET-Blot method as a sensitive complementary tool in case of doubtful PrP IHC results.
PMCID: PMC2923130  PMID: 20684771
8.  Comparative Molecular Analysis of the Abnormal Prion Protein in Field Scrapie Cases and Experimental Bovine Spongiform Encephalopathy in Sheep by Use of Western Blotting and Immunohistochemical Methods 
Journal of Virology  2004;78(7):3654-3662.
Since the appearance of bovine spongiform encephalopathy (BSE) in cattle and its linkage with the human variant of Creutzfeldt-Jakob disease, the possible spread of this agent to sheep flocks has been of concern as a potential new source of contamination. Molecular analysis of the protease cleavage of the abnormal prion protein (PrP), by Western blotting (PrPres) or by immunohistochemical methods (PrPd), has shown some potential to distinguish BSE and scrapie in sheep. Using a newly developed enzyme-linked immunosorbent assay, we identified 18 infected sheep in which PrPres showed an increased sensitivity to proteinase K digestion. When analyzed by Western blotting, two of them showed a low molecular mass of unglycosylated PrPres as found in BSE-infected sheep, in contrast to other naturally infected sheep. A decrease of the labeling by P4 monoclonal antibody, which recognizes an epitope close to the protease cleavage site, was also found by Western blotting in the former two samples, but this was less marked than in BSE-infected sheep. These two samples, and all of the other natural scrapie cases studied, were clearly distinguishable from those from sheep inoculated with the BSE agent from either French or British cattle by immunohistochemical analysis of PrPd labeling in the brain and lymphoid tissues. Final characterization of the strain involved in these samples will require analysis of the features of the disease following infection of mice, but our data already emphasize the need to use the different available methods to define the molecular properties of abnormal PrP and its possible similarities with the BSE agent.
PMCID: PMC371064  PMID: 15016886

Results 1-8 (8)