Current Pharmaceutical Biotechnology - Volume 17, Issue 2, 2016

Proteins are prone to inactivation in aqueous solutions because chemical modification and aggregation usually occur, particularly at high temperature. This review focuses on the recent advance in practical application with amine compounds that prevent the heat-induced inactivation and aggregation of proteins. Coexistence of amine solutes, typically diamines, polyamines, amino acid esters, and amidated amino acids decreases the heat-induced inactivation rate of proteins by one order of magnitude compared with that in the absence of additives under low concentrations of proteins at physiological pH. The amine compounds mainly suppress chemical modification, typically the β-elimination of disulfide bond and deamidation of asparagine side chain, thereby preventing heat-induced inactivation of proteins. Polyamines do not improve the refolding yield of proteins, owing to decrease in the solubility of unfolded proteins. In contrast, arginine is the most versatile additive for various situations, such as refolding of recombinant proteins, solubilized water-insoluble compounds, and prevention of nonspecific binding to solid surfaces; however, it is not always effective for preventing heat-induced aggregation. Amine compounds will be a key to prevent protein inactivation in solution additives.

Microorganisms prefer to live in three-dimensional self-organized communities (biofilms), and this behavior provides microbial pathogens inhabiting various sites in the human body or on medical devices with survival advantages. In fact, pathogens in the biofilm stage exhibit up to a thousandfold more tolerance to conventional antimicrobial agents, and thus, they are difficult to eradicate and biofilms generated during acute infections become persistent, chronic, and recurrent. Consequently, novel strategies are being sought to control biofilm associated infections. The developmental strategies used include improved drug delivery and the penetration of biofilm matrices, and in particular, natural products that interfere with virulence and cross talk between microbial cells are being investigated as potential anti-biofilm agents. This article provides an overview of existing and promising biofilm control strategies based on plant and microbial products. Control strategies like quorum sensing inhibition, microbial antibiosis, and the uses of phages and probiotics are reviewed along with current developments in high throughput screening and in our understanding of structure activity relationships related to the regulation of biofilms by small molecules.

Urate oxidase is considered as an important therapeutic enzyme used to control hyperuricemia. In spite of widespread distribution in numerous (micro)organisms, active urate oxidase is absent in higher primates (humans and apes) due to gene mutations. Considering the therapeutic significance of urate oxidase, further understanding on the inactivation process of the enzyme during primate evolution is critical. This study, therefore, aims to express genetically modified human urate oxidase in the methylotrophic yeast Pichia pastoris. Accordingly, the genetically modified human urate oxidase was successfully expressed intracellularly and extracellularly under the control of an alcohol oxidase promoter and was subjected to the enzyme activity assay. The results demonstrated that reactivating the non-functional human urate oxidase gene fully or even moderately by simply replacing the premature stop codons is impossible. This finding confirms the idea that a number of successive loss-of-function missense mutations occurred during evolution, making higher primates functional uricase-deficit and vulnerable to hyperuricemic disorders.

As the principal active ingredient in the Chinese herb Tripterygium wilfordii Hook.F (TwHF), triptolide has been shown to have very strong antitumor properties. The trimethylation of lysine 4 on histone H3 (H3K4me3) has been proposed to promote gene expression, and the accumulation of H3K4me3 at the transcriptional start sites of oncogenes is involved in carcinogenesis. To identify the association between the reduction of H3K4me3 and the apoptosis of MM cells induced by triptolide, we investigated the global patterns of H3K4me3 occupancy in the MM cell genome. Combined analyses using ChIP-on-chip and western blotting showed that H3K4me3 were highly enriched on the gene promoters of c-Myc and VEGFA and were associated with the up-regulation of both genes. Treatment of KM3 cells with triptolide and siRNA targeting ASH2L reduced the expression of c-Myc and VEGFA. These results suggest that triptolide can down-regulate c-Myc and VEGFA expression by blocking the accumulation of H3K4me3 on their promoters,and thus play an important role in anti-MM mechanism.

Estrogen is one of the most important signaling molecules which targets a number of genes. Estrogen levels regulate cell proliferation and a plethora of metabolic processes, which may interfere with a range of medical conditions and drug metabolism. The MCF7 breast cancer cell line, expressing the estrogen receptor α, is a well-studied model of cellular answer to estrogen. The aim of this study was to characterize transcriptomic responses to estrogen in a broad time range. We performed a meta-analysis of microarray data on gene expression in the MCF7 cells under estrogen exposure and deprivation. As the result we distinguished three major phases of transcriptomic response to stimulation with 17β- estradiol: the early (1-2 h), with the activation of the MAPK signaling pathway; the intermediate (3-12 h), with enhanced expression of genes participating in cell surface receptor linked signal transduction and cellular homeostasis; and the late one (24-48 h), with the induction of genes involved in mitotic cell division. Two main phases under estrogen starvation were indicated as the early (1-3 days), with elevated expression of genes associated with cell projection and repression of those responsible for cell cycle regulation, and the late (15-180 days), with increased expression of genes of cell adhesion proteins. The meta-analysis displayed how different gene sets are either induced or repressed following either estrogen exposure or deprivation, and how the gene expression changes are orchestrated by estrogen in time dependent manner, indicating that proper understanding of estrogen impact on transcriptional gene activity requires an extensive time perspective.

Sugar rich diet induces inflammation and insulin resistance mainly through gut microbiota alteration. Gut microflora dysbiosis increases plasma lipopolysaccharide and reduces short chain fatty acids to impair the insulin signaling cascades by different molecular pathways to progress into diabetes. Chitosan based formulations have major significance in insulin delivery system due to their ability to protect the insulin from enzymatic degradation and its efficient inter-epithelial transport. This study was designed to investigate the effect of chitosan administration on gut microflora mediated signaling pathways to prevent the diet induced diabetes. Male wistar rats were divided into non-diabetic group with a normal diet (CD), diabetic group with high sucrose diet (HSD) and treatment group with HSD and chitosan (60 mg/kg). After 8 weeks of the study, significant alterations in two major gut dominant microbial phyla i.e Firmicutes and Bacteroides and four dominant microbial species i.e. Lactobacilli, Bifidobacteria, Escherichia and Clostridia were observed in HSD group compared to CD. This microbial dysbiosis in dominant phyla was significantly prevented in chitosan administrated HSD group. Chitosan administration had also reduced the HSD induced activation of Toll like receptors and Nod like receptors signaling pathways compared to HSD control group to reduce the inflammation. These suggest that chitosan can prevent the progression of Type 2 Diabetes through gut microbiota alteration, reducing endotoxin and microbes mediated inflammation.

Excessive use of pesticides in agriculture has resulted in contamination of water resources, air, soil and disruption of biogeochemical cycles. These compounds adversely affect humans and animal health, helpful soil microbes and crop production as well. Biodegradation of pesticides by microbes exists in a number of habitats like soil, sediments, surface, ground water, and sludge, etc. In the present study, efforts were made to develop a microbial consortium comprising of Streptomyces albogriseolus and Brevibacillus borstelensis strains isolated earlier which are capable of degrading carbendazim, a benzimidazole fungicide and making it harmless. Both the strains Brevibacillus borstelensis and Streptomyces albogriseolus displayed growth even at higher concentrations (500μg mL-1) of carbendazim. The consortium containing Brevibacillus borstelensis and Streptomyces albogriseolus reduced carbendazim concentration from 30 μg mL-1 to 0.86 μg mL-1 (nearly 97%) in 12hrs to 0.60 μg mL-1 (~98%) in 20 hrs as determined by LCMS analysis. There was a significant reduction observed in carbendazim concentration than reduction obtained when individual strain was used. This study paves a way for further exploration of degradation mechanism at the genetic level to enhance the capability of microorganisms in consortia.

It is important to establish an easy-to-use therapeutic protocol for the emergency medical care of patients involved in radiation accidents to reduce the radiation-related casualties. The present study aimed to establish an optimum therapeutic protocol using currently approved pharmaceutical drugs to increase the survival of victims exposed to lethal radiation. Different combinations of four drugs-recombinant human erythropoietin (EPO), granulocyte-colony stimulating factor (G-CSF), c-mpl receptor agonist romiplostim (RP) and nandrolone decanoate (ND)-were administered to mice within 2 h after exposure to a lethal 7 Gy dose of γ-irradiation. On day 30 after irradiation, the condition of the mice was analyzed using various hematological parameters, such as the number of peripheral blood cells, bone marrow cells, hematopoietic progenitor cells and the expression of cell surface antigens. Approximately 10% of the untreated irradiated control mice survived for 21 days, but all of the control mice died by day 30. The combined administration of G-CSF, EPO and RP for five days immediately after irradiation led to a complete survival of the irradiated mice until day 30. However, the treatment with G-CSF, EPO and RP with ND led to only 75% survival at day 30. The hematological analyses showed that the numbers of almost all of hematopoietic cells in the surviving mice treated with effective medications recovered to the levels of non-irradiated mice. The present findings show that the combination of G-CSF, EPO and RP may be a useful countermeasure for victims exposed to accidental lethal irradiation.

Mammalian cells are involved in a range of biotechnological applications and more recently have been increasingly exploited in regenerative medicine. Critical to successful applications involving mammalian cells are their long-term storage and transport, for which cryopreservation in liquid nitrogen is the most frequently used strategy. However, cryopreservation suffers from high costs, difficulties in transport logistics and the use of undesirable additives (e.g. animal sera or DMSO). An alternative approach, proposed as low cost, low maintenance and process-compatible, is viable desiccation of mammalian cells. Several groups claim to have achieved this, but the extent of desiccation in the cell samples concerned is not always clear, in part because of difficulties in determining very low water content. Although several techniques exist that are frequently used to quantify the amount of water in samples (e.g. FTIR spectroscopy, thermogravimetric analysis (TGA), NMR spectroscopy), the complexity of sample preparation, as well as the costs and time constraints involved are disadvantageous. Here, we assess a novel, rapid and low cost technique, i.e. terahertz (THz) spectroscopy, for the quantification of water content within dehydrated mammalian cell samples.