Effect of sodium butyrate on mammalian cells in culture: a review.

Sodium butyrate produces reversible changes in morphology, growth rate, and enzyme activities of several mammalian cell types in culture. Some of these changes are similar to those produced by agents which increase the intracellular level of adenosine 3',5'-cyclic monophosphate (cAMP) or by analogs of cAMP. Sodium butyrate increases the intracellular level of cAMP by about two fold in neuroblastoma cells; therefore, some of the effects of sodium butyrate on these cells may in part be mediated by cAMP. Sodium butyrate appears to have properties of a good chemotherapeutic agent for neuroblastoma tumors because the treatment of neuroblastoma cells in culture causes cell death and "differentiation"; however, it is either innocuous or produces reversible morphological and biochemical alterations in other cell types.     

Refolding of sepharose-bound trypsinogen with disulfide 179 to 203 reduced and carboxymethylated

Disulfide 179 to 203 of native bovine trypsin was reduced with sodium borohydride and converted to the S-carboxymethyl derivative. The modified zymogen was attached to CNBr-activated Sepharose, and the resulting immobilized protein was used in refolding studies. The fully reduced protein was kept at 35°, at pH 8.5, under aerobic conditions, in a mixture of reduced and oxidized glutathione, until the sulfhydryl groups were reoxidized. A maximum yield of 55% was found for the regeneration of S-(carboxymethyl)₂-trypsinogen, and the activated product, S-(carboxymethyl)₂-trypsin, reacted with an active site reagent and gave the expected specific activity toward a typical trypsin substrate. Apparently, the refolding of immobilized S-(carboxymethyl)₂-trypsinogen regenerated the native structure of trypsinogen even though one of the six disulfides could no longer be formed.     

Effect of sodium butyrate on mammalian cells in culture: A review

Summary Sodium butyrate produces reversible changes in morphology, growth rate, and enzyme activities of several mammalian cell types in culture. Some of these changes are similar to those produced by agents which increase the intracellular level of adenosine 3′,5′-cyclic monophosphate (cAMP) or by analogs of cAMP. Sodium butyrate increases the intracellular level of cAMP by about two fold in neuroblastoma cells; therefore, some of the effects of sodium butyrate on these cells may in part be mediated by cAMP. Sodium butyrate appears to have properties of a good chemotherapeutic agent for neuroblastoma tumors because the treatment of neuroblastoma cells in culture causes cell death and “differentiation”; however, it is either innocuous or produces reversible morphological and biochemical alterations in other cell types.     

Benchmarking of a Bayesian single cell RNAseq differential gene expression test for dose–response study designs

The application of single-cell RNA sequencing (scRNAseq) for the evaluation of chemicals, drugs, and food contaminants presents the opportunity to consider cellular heterogeneity in pharmacological and toxicological responses. Current differential gene expression analysis (DGEA) methods focus primarily on two group comparisons, not multi-group dose–response study designs used in safety assessments. To benchmark DGEA methods for dose–response scRNAseq experiments, we proposed a multiplicity corrected Bayesian testing approach and compare it against 8 other methods including two frequentist fit-for-purpose tests using simulated and experimental data. Our Bayesian test method outperformed all other tests for a broad range of accuracy metrics including control of false positive error rates. Most notable, the fit-for-purpose and standard multiple group DGEA methods were superior to the two group scRNAseq methods for dose–response study designs. Collectively, our benchmarking of DGEA methods demonstrates the importance in considering study design when determining the most appropriate test methods.     

QTL-seq for the identification of candidate genes for days to flowering and leaf shape in pigeonpea

To identify genomic segments associated with days to flowering (DF) and leaf shape in pigeonpea, QTL-seq approach has been used in the present study. Genome-wide SNP profiling of extreme phenotypic bulks was conducted for both the traits from the segregating population (F₂) derived from the cross combination- ICP 5529 × ICP 11605. A total of 126.63 million paired-end (PE) whole-genome resequencing data were generated for five samples, including one parent ICP 5529 (obcordate leaf and late-flowering plant), early and late flowering pools (EF and LF) and obcordate and lanceolate leaf shape pools (OLF and LLS). The QTL-seq identified two significant genomic regions, one on CcLG03 (1.58 Mb region spanned from 19.22 to 20.80 Mb interval) for days to flowering (LF and EF pools) and another on CcLG08 (2.19 Mb region spanned from 6.69 to 8.88 Mb interval) for OLF and LLF pools, respectively. Analysis of genomic regions associated SNPs with days to flowering and leaf shape revealed 5 genic SNPs present in the unique regions. The identified genomic regions for days to flowering were also validated with the genotyping-by-sequencing based classical QTL mapping method. A comparative analysis of the identified seven genes associated with days to flowering on 12 Fabaceae genomes, showed synteny with 9 genomes. A total of 153 genes were identified through the synteny analysis ranging from 13 to 36. This study demonstrates the usefulness of QTL-seq approach in precise identification of candidate gene(s) for days to flowering and leaf shape which can be deployed for pigeonpea improvement.Subject terms: Genetic association study, Plant hybridization

QTL-seq approach was utilized for mapping of genomic regions/genes associated with days to flowering and leaf shape in pigeonpea. Analysis of genomic regions and associated SNPs with days to flowering and leaf shape revealed 1 and 4 non-synonymous SNPs, respectively. The study demonstrated sequencing-based trait mapping approach can accelerate trait mapping of the targeted traits.     

P. falciparum RH5‐Basigin interaction induces changes in the cytoskeleton of the host RBC

The successful invasion of Plasmodium is an essential step in their life cycle. The parasite reticulocyte‐binding protein homologues (RHs) and erythrocyte‐binding like proteins are two families involved in the invasion leading to merozoite‐red blood cell (RBC) junction formation. Ca²⁺ signaling has been shown to play a critical role in the invasion. RHs have been linked to Ca²⁺ signaling, which triggers the erythrocyte‐binding like proteins release ahead of junction formation, consistent with RHs performing an initial sensing function in identifying suitable RBCs. RH5, the only essential RHs, is a highly promising vaccine candidate. RH5‐basigin interaction is essential for merozoite invasion and also important in determining host tropism. Here, we show that RH5 has a distinct function from the other RHs. We show that RH5‐Basigin interaction on its own triggers a Ca²⁺ signal in the RBC resulting in changes in RBC cytoskeletal proteins phosphorylation and overall alterations in RBC cytoskeleton architecture. Antibodies targeting RH5 that block the signal prevent invasion before junction formation consistent with the Ca²⁺ signal in the RBC leading to rearrangement of the cytoskeleton required for invasion. This work provides the first time a functional context for the essential role of RH5 and will now open up new avenues to target merozoite invasion.     

Oxidative dealkylation of a hindered phenol catalyzed by copper (II) bis benzimidazole diamide complex

The oxidative dealkylation of 2,4,6-tri-tert-butylphenol (TTBP) has been investigated using molecular oxygen and [Cu(NO₃(GBHA)](NO₃) as catalyst, where GBHA is N,N′-bis((benzimidazol-2-yl)methyl)hexanediamide [(a) M. Gupta, P. Mathur, R.J. Butcher, Inorg. Chem. 40 (2001) 878; (b) M. Gupta, S.K. Das, P. Mathur, A.W. Cordes, Inorg. Chim. Acta 353 (2003) 197; (c) S. Tehlan, M.S. Hundal, P. Mathur, Inorg. Chem. 43 (2004) 6589; (d) F. Afreen, P. Mathur, A. Rheingold, Inorg. Chim. Acta 358 (2005) 1125.]. X-ray structural characterization of complex [Cu(NO₃)(GBHA)](NO₃) · CH₃OH confirms that the Cu (II) ion is in a distorted square pyramidal geometry (τ = 0.168). The TTBP oxidation reaction proceeds via tri-tert-butylphenoxyl radical producing two products 2,6-di-tert-butyl-1,4-benzoquinone (A) and 4,6-di-tert-butyl-1,2-benzoquinone (B). Both A and B have been well characterized by ¹H NMR, ¹³C NMR, UV-Vis and mass data.     

Immunization with recombinant adenovirus synthesizing the secretory form of Japanese encephalitis virus envelope protein protects adenovirus-exposed mice against lethal encephalitis

Replication-defective recombinant adenoviruses (RAds) were constructed that synthesized the pre-membrane and envelope (E) proteins of Japanese encephalitis virus (JEV). Recombinant virus RAdEa synthesized Ea, the membrane-anchored E protein, and RAdEs synthesized Es, the secretory E protein. Compared with RAdEs, RAdEa replicated poorly in HEK 293A cells and synthesized lower amounts of E protein. Oral immunization of mice with RAds generated low titers of anti-JEV antibodies that had little JEV neutralizing activity. Intra-muscular (IM) immunization of mice with either RAd generated high titers of anti-JEV antibodies. Interestingly, RAdEa induced only low titers of JEV neutralizing antibodies. Titers were significantly higher in case of RAdEs immunization. Splenocytes from mice immunized IM with RAds secreted large amounts of interferon-γ and moderate amounts of interleukin-5 in the presence of JEV and showed cytotoxic activity against JEV-infected cells. Naïve mice immunized IM with RAdEs showed complete protection against a lethal dose of JEV given intra-cerebrally. In order to study the effect of the pre-existing adenovirus 5 (Ad5) immunity on the outcome of the RAdEs immunization, mice were exposed to Ad5 through IM or intra-nasal (IN) routes before immunization with RAdEs. Mice exposed to Ad5 through the IN route, when immunized with RAdEs given IM, or those exposed to Ad5 through the IM route, when immunized with RAdEs given IN, were completely protected against lethal JEV challenge.     

Inhibition of Neuronal Apoptosis by a Metalloporphyrin Superoxide Dismutase Mimic

Abstract: The objective of this study was to determine whether free radicals play a pathogenic role in neuronal apoptosis. The ability of Mn(III) tetrakis(benzoic acid) porphyrin (MnTBAP), a superoxide dismutase mimic, to inhibit staurosporine-induced neuronal apoptosis was tested in mixed cerebrocortical cultures. Staurosporine produced concentration-dependent cell death that was markedly inhibited by MnTBAP. Immunocytochemical analyses of cultures for neuron- and astrocyte-specific markers revealed that high concentrations of staurosporine induced the death of both neurons and astrocytes; both cell types were protected by MnTBAP. A less active congener of MnTBAP failed to protect cells against staurosporine-induced apoptosis. MnTBAP also protected cortical cultures against ceramide-induced apoptosis. These results support a role for oxidative stress in neuronal apoptosis.