Burn resuscitation strategy influences the gut microbiota-liver axis in swine.

Fluid resuscitation improves clinical outcomes of burn patients; however, its execution in resource-poor environments may have to be amended with limited-volume strategies. Liver dysfunction is common in burn patients and gut dysbiosis is an understudied aspect of burn sequelae. Here, the swine gut microbiota and liver transcripts were investigated to determine the impact of standard-of-care modified Brooke (MB), limited-volume colloid (LV-Co), and limited-volume crystalloid (LV-Cr) resuscitation on the gut microbiota, and to evaluate its' potential relationship with liver dysfunction. Independent of resuscitation strategy, bacterial diversity was reduced 24 h post-injury, and remained perturbed at 48 h. Changes in community structure were most pronounced with LV-Co, and correlated with biomarkers of hepatocellular damage. Hierarchical clustering revealed a group of samples that was suggestive of dysbiosis, and LV-Co increased the risk of association with this group. Compared with MB, LV-Co and LV-Cr significantly altered cellular stress and ATP pathways, and gene expression of these perturbed pathways was correlated with major dysbiosis-associated bacteria. Taken together, LV-Co resuscitation exacerbated the loss of bacterial diversity and increased the risk of dysbiosis. Moreover, we present evidence of a linkage between liver (dys)function and the gut microbiota in the acute setting of burn injury.

Design, synthesis and biological evaluation of novel pyrenyl derivatives as anticancer agents.

Polycyclic aromatic hydrocarbons are widespread in nature with a toxicity range from non-toxic to extremely toxic. A series of pyrenyl derivatives has been synthesized following a four-step strategy where the pyrene nucleus is attached with a basic heterocyclic moiety through a carbon linker. Virtual screening of the physicochemical properties and druggability has been carried out. The cytotoxicity of the compounds (1-8) have been evaluated in vitro against a small panel of human cancer cell lines which includes two liver cancer (HepG2 and Hepa 1-6), two colon cancer (HT-29 and Caco-2) and one each for cervical (HeLa) and breast (MCF-7) cancer cell lines. The IC50 data indicate that compound 6 and 8 are the most effective cytotoxic agents in the present set of pyrenyl derivatives, suggesting that having a 4-carbon linker is more effective than a 5-carbon linker and the presence of amide carbonyl groups in the linker severely reduces the efficacy of the compound. The compounds showed selectivity toward cancer cells at lower doses (<5 µM) when compared with the normal hepatocytes. The mechanism of action supports the cell death through apoptosis in a caspase-independent manner without cleavage of poly (ADP-ribose) polymerase (PARP), even though the compounds cause plasma membrane morphological changes. The compounds, whether highly cytotoxic or mildly cytotoxic, localize to the membrane of cells. The compounds with either a piperidine ring (6) or an N-methyl piperazine (8) in the side chain were both capable of circumventing the drug resistance in SKOV3-MDR1-M6/6 ovarian cancer cells overexpressing P-glycoprotein. Qualitative structure-activity relationship has also been studied.

Bismuth nitrate-induced novel nitration of estradiol: an entry to new anticancer agents.

Direct nitration of estradiol was carried out using metal nitrates on solid surfaces under mild condition, and a combination of bismuth nitrate pentahydrate impregnated KSF clay was found to be the best reagent to synthesize 2- and 4-nitroestradiol effectively. Furthermore, various basic side chains were introduced, through O-linker at C-3, to these nitroestradiols. The ability of these derivatives to cause cytotoxicity in Estrogen Receptor (ER)-positive and ER-negative breast cancer cell lines, as well as cancer cell lines of other origins, was examined. Qualitative structure activity relationship (SAR) has also been studied. We found that a basic side chain containing either a piperidine or morpholine ring, when conjugated to 2-nitroestradiol, was particularly effective at causing cytotoxicity in each of the cancer cell lines examined. Surprisingly, this effective cytotoxicity was even seen in ER-negative breast cancer cells.

A novel Bacillus thuringiensis Cry-like protein from a rare filamentous strain promotes crystal localization within the exosporium.

Mutation of a novel cry-like gene (cry256) from Bacillus thuringiensis resulted in a protein crystal, normally located within the spore's exosporium, being found predominately outside the exosporium. The cry256 gene codes for a 3-domain Cry-like protein that does not correspond to any of the known Cry protein holotypes.

Inhibition of neddylation represses lipopolysaccharide-induced proinflammatory cytokine production in macrophage cells.

Cullin-RING E3 ligases (CRLs) are a class of ubiquitin ligases that control the proteasomal degradation of numerous target proteins, including IκB, and the activity of these CRLs are positively regulated by conjugation of a Nedd8 polypeptide onto Cullin proteins in a process called neddylation. CRL-mediated degradation of IκB, which normally interacts with and retains NF-κB in the cytoplasm, permits nuclear translocation and transactivation of the NF-κB transcription factor. Neddylation occurs through a multistep enzymatic process involving Nedd8 activating enzymes, and recent studies have shown that the pharmacological agent, MLN4924, can potently inhibit Nedd8 activating enzymes, thereby preventing neddylation of Cullin proteins and preventing the degradation of CRL target proteins. In macrophages, regulation of NF-κB signaling functions as a primary pathway by which infectious agents such as lipopolysaccharides (LPSs) cause the up-regulation of proinflammatory cytokines. Here we have analyzed the effects of MLN4924, and compared the effects of MLN4924 with a known anti-inflammatory agent (dexamethasone), on certain proinflammatory cytokines (TNF-α and IL-6) and the NF-κB signaling pathway in LPS-stimulated macrophages. We also used siRNA to block neddylation to assess the role of this molecular process during LPS-induced cytokine responsiveness. Our results demonstrate that blocking neddylation, either pharmacologically or using siRNA, abrogates the increase in certain proinflammatory cytokines secreted from macrophages in response to LPS. In addition, we have shown that MLN4924 and dexamethasone inhibit LPS-induced cytokine up-regulation at the transcriptional level, albeit through different molecular mechanisms. Thus, neddylation represents a novel molecular process in macrophages that can be targeted to prevent and/or treat the LPS-induced up-regulation of proinflammatory cytokines and the disease processes associated with their up-regulation.

Polycyclic aromatic compounds as anticancer agents: Evaluation of synthesis and in vitro cytotoxicity.

Polycyclic aromatic hydrocarbons (PAHs) are considered to be significant environmental carcinogens. Additionally, various planar ring systems are capable of intercalating with DNA, leading to a number of drugs that possess chemotherapeutic activity. In this study, three new polyaromatic compounds with a side chain were synthesized, and spectroscopic as well as elemental analyses were performed. The addition of the long chains to either chrysene or pyrene caused a red-shift in the spectral emission when compared to the corresponding polycyclic aromatic hydrocarbons itself. Furthermore, the cytotoxicity of the three novel polyaromatic compounds was evaluated in vitro in a panel of cultured mammalian cell lines. The pyrenyl ether demonstrated better cytotoxicity compared to cisplatin against colon (HT-29) as well as cervical (HeLa) cancer cell lines. In conclusion, three new compounds were synthesized and investigated in this study. This novel method is likely to play a role in other areas of research.

Ultrasound-assisted bismuth nitrate-induced green synthesis of novel pyrrole derivatives and their biological evaluation as anticancer agents.

A series of novel N-substituted pyrrole derivatives have been designed and synthesized following ultrasound-assisted and bismuth nitrate-catalyzed eco-friendly route. This reaction has also provided a general method to prepare diverse varieties of N-substituted pyrroles with less nucleophilic polyaromatic amines. Based on (1)H NMR spectroscopy, a plausible mechanistic pathway has been advanced. Cytotoxicity of some selected N-substituted pyrrole derivatives has been evaluated in vitro in a panel of mammalian cancer cell lines which includes liver cancer cell lines (HepG2 and Hepa1-6), colon cancer cell lines (HT-29 and Caco-2), a cervical cancer cell line (HeLa) and NIH3T3 cells. Two compounds, 5-(1H-pyrrol-1-yl)-1,10-phenanthroline (9) and 1-(phenanthren-2-yl)-1H-pyrrole (10) have shown good cytotoxicity against some cancer cell lines. Furthermore, these compounds have exhibited cytotoxic specificity against liver cancer cell lines in vitro when compared with normal cultured primary hepatocytes.

Parasporins from a Caribbean Island: evidence for a globally dispersed Bacillus thuringiensis strain.

Parasporins represent a new functional class of Cry (crystal protein) toxins produced by the bacterium Bacillus thuringiensis (Bt). Unlike Cry toxins that demonstrate activity mainly against some insect cells, parasporins are characterized as being non-hemolytic, yet capable of preferentially killing some human cancer cells. Globally, six different parasporin types, PS1-PS6, based on protein sequence homology, have been identified in only four countries (Japan, Vietnam, India, and Canada). Herein we report the results of a screening study of 160 Bt isolates collected from the Caribbean island of Trinidad. One isolate (strain 64-1-94) was shown to kill human cancer cells and to contain one ps6 and two ps1 parasporin genes. The two ps1 genes were located approximately 6 kb apart from each other, sharing a similar spatial arrangement, and high sequence homology, with two plasmid-located ps1 genes, ps1Aa6 and ps1Ad1, recently isolated from a Japanese strain. Evidence is also presented that a parasporin gene reported previously for a Canadian strain, ps1Aa2, is most likely derived from a recombination event between these same two genes found in the Trinidadian and Japanese strains. Notably, all three strains share a ps6 parasporin gene, presumably located on a separate plasmid. These data suggest that the global population of ps1 genes may be have originated from a single pair of parasporin genes. Given the large geographical distance between the collection sites, which are located on both continental land masses and islands at sea, ps1 genes are able to retain a remarkable level of homology not easily explained.

An exploratory study of methicillin-resistant Staphylococcus aureus and SCCmec elements obtained from a community setting along the Texas border with Mexico.

An exploratory study of methicillin-resistant Staphylococcus aureus (MRSA) and SCCmec elements in bacteria along the Mexican border of south Texas was performed. Between September and December of 2008, 375 swabs of anterior nares were self-collected by students attending the University of Texas-Pan American (UTPA) and cultured for MRSA. Fifty seven bacterial isolates were kept for further analysis that included suspected MRSA and other SCCmec-containing bacteria. Isolates were examined for the presence of nuc, mecA, lukS-PV, and spa genes using PCR. SCCmec and spa typing were also performed. Seven S. aureus isolates were found of which six were classified as MRSA. SCCmec typing showed five of the six MRSA strains to be type IV, while one MRSA strain, and most of the non-S. aureus strains, were untypeable, producing results that were indicative of mixed SCCmec types. Five of the six MRSA strains contained known spa types (two of which corresponded to USA300 and one to USA600), while one strain had a novel spa type. Only one isolate, a USA300 MRSA, was positive for lukS-PV. Easy access by the Texas border community to antibiotics in Mexico without a prescription, and the strong partition in SCCmec types between MRSA and non-S. aureus bacteria suggest that this border region of Texas may be uniquely suited for the study of emerging SCCmec types, their horizontal transfer, and perhaps other aspects of antibiotic resistance in bacteria.