Current updates on precision therapy for breast cancer associated brain metastasis: Emphasis on combination therapy

Molecular and Cellular Biochemistry - Cancer therapies have undergone a tremendous progress over the past decade. Precision medicine provides a more tailored approach, making the combination of...     

Antagonistic Activity of Antimicrobial Metabolites Produced from Seaweed-Associated Bacillus amyloliquefaciens MTCC 10456 Against Malassezia spp.

Probiotics and Antimicrobial Proteins - Members of the genus Malassezia are known to be opportunistic pathogens responsible for causing skin disorders such as seborrheic dermatitis or dandruff,...     

CD8+ cellular immunity mediates rAd5 vaccine protection against Ebola virus infection of nonhuman primates

Vaccine-induced immunity to Ebola virus infection in nonhuman primates (NHPs) is marked by potent antigen-specific cellular and humoral immune responses; however, the immune mechanism of protection remains unknown. Here we define the immune basis of protection conferred by a highly protective recombinant adenovirus virus serotype 5 (rAd5) encoding Ebola virus glycoprotein (GP) in NHPs. Passive transfer of high-titer polyclonal antibodies from vaccinated Ebola virus-immune cynomolgus macaques to naive macaques failed to confer protection against disease, suggesting a limited role of humoral immunity. In contrast, depletion of CD3(+) T cells in vivo after vaccination and immediately before challenge eliminated immunity in two vaccinated macaques, indicating a crucial requirement for T cells in this setting. The protective effect was mediated largely by CD8(+) cells, as depletion of CD8(+) cells in vivo using the cM-T807 monoclonal antibody (mAb), which does not affect CD4(+) T cell or humoral immune responses, abrogated protection in four out of five subjects. These findings indicate that CD8(+) cells have a major role in rAd5-GP-induced immune protection against Ebola virus infection in NHPs. Understanding the immunologic mechanism of Ebola virus protection will facilitate the development of vaccines for Ebola and related hemorrhagic fever viruses in humans.     

Two functionally distinctive phosphopantetheinyl transferases from amoeba Dictyostelium discoideum

The life cycle of Dictyostelium discoideum is proposed to be regulated by expression of small metabolites. Genome sequencing studies have revealed a remarkable array of genes homologous to polyketide synthases (PKSs) that are known to synthesize secondary metabolites in bacteria and fungi. A crucial step in functional activation of PKSs involves their post-translational modification catalyzed by phosphopantetheinyl transferases (PPTases). PPTases have been recently characterized from several bacteria; however, their relevance in complex life cycle of protozoa remains largely unexplored. Here we have identified and characterized two phosphopantetheinyl transferases from D. discoideum that exhibit distinct functional specificity. DiAcpS specifically modifies a stand-alone acyl carrier protein (ACP) that possesses a mitochondrial import signal. DiSfp in contrast is specific to Type I multifunctional PKS/fatty acid synthase proteins and cannot modify the stand-alone ACP. The mRNA of two PPTases can be detected during the vegetative as well as starvation-induced developmental pathway and the disruption of either of these genes results in non-viable amoebae. Our studies show that both PPTases play an important role in Dictyostelium biology and provide insight into the importance of PPTases in lower eukaryotes.     

Depolarization and cardiolipin depletion in aged rat brain mitochondria: relationship with oxidative stress and electron transport chain activity

A noticeable loss of cardiolipin, a significant accumulation of fluorescent products of lipid peroxidation and an increased ability to produce reactive oxygen species in vitro are characteristics of aged rat brain mitochondria, as has been demonstrated in this study. In contrast mitochondrial electron transport chain activity is not significantly compromised except a marginal decline in complex IV activity in aged rat brain. On the other hand, a striking loss of mitochondrial membrane potential occurs in brain mitochondria during aging, which may be attributed to peroxidative membrane damage in this condition. Such mitochondrial dysfunctions as reported here may lead to uncoupling of oxidative phosphorylation, ATP depletion and activation of apoptotic cascade in aged rat brain.     

A versatile photocleavable bifunctional linker for facile synthesis of substrate-DNA conjugates for the selection of nucleic acid catalysts

Covalent photocleavable attachment of small molecules or peptides to oligonucleotides is an integral strategic element in the selection of novel nucleic acid enzymes. Here, we report the synthesis of a multipurpose, photocleavable bifunctional linker (PCBL) suitable for nucleic acid selections and other biotechnology applications. PCBL contains a photocleavable O-nitrobenzyl group flanked on one side by an N-hydroxysuccinimidyl ester (reactive toward primary amines) and on the other side by a sulfhydryl. To demonstrate the utility of PCBL, the linker was used to couple an analog of the antibiotic chloramphenicol (Cam) to the 5' end of an amino-modified 8-mer DNA oligo. Coupling was confirmed by MALDI-TOF spectrophotometry. Decoupling was performed by irradiating the coupled species with near-UV light (approximately 360 nm), regenerating the original amino-modified oligo. Ligation of the Cam-PCBL-DNA conjugate to random-sequence RNA generated a diversity library appropriate for the selection of new ribozymes that catalyze reactions involving the tethered substrate. Coupling and decoupling of the Cam analog from the library was monitored on a trilayered organomercurial polyacrylamide gel. The coupling/decoupling strategy described here is readily generalized to many combinations of macromolecules and small molecules. For example, analogs of this small molecule-DNA conjugate can be generated as synthons for ligation to nucleic acid diversity libraries during each round of novel ribozyme selections, or they can be immobilized onto chips for addresssably reversible microarray analysis.     

Consistent production of kojic acid from Aspergillus sojae SSC-3 isolated from rice husk

Molecular Biology Reports - A consistent kojic acid producing fungal strain has been isolated from rice husk using glucose-peptone medium. The isolate was identified as Aspergillus sojae SSC-3 on...