Current Pharmaceutical Biotechnology - Volume 19, Issue 11, 2018

Pain affects approximately 30% of people and places a large economic and social burden on society. Despite the availability of a range of analgesics, complete alleviation of symptoms still rarely occurred. Effective and safe drugs for the treatment of pain are still an unmet clinical need. In recent years, the voltage-gated sodium channels (VGSCs) have been recognized as potential targets for analgesic development. VGSCs are major players in generating and propagating action potentials. They represent an appealing target for the development of new and safer drugs in the treatment of pain. The majority of the research has been focused on Nav1.7 in particular, other VGSC subtypes, such as Nav1.1, Nav1.3, Nav1.6, Nav1.8 and Nav1.9 have recently come to the forefront of analgesic research. Peptides from scorpion have been proved to be a valuable tool in neuroscience, playing a significant role in the identification and characterization of VGSC subtypes and many of them resulting in analgesia in pain. This review assesses the potential of scorpion toxin targeting VGSCs for analgesic development.

Background: Nattokinase is a potent fibrinolytic protease, which is used as a drug for treatment or a supplement for preventing thrombosis besides various industrial applications. The present study aimed to produce a soluble nattokinase in low cost media, which has with high activity and resistance to metal ions, detergents, and organic solvents, and can be easily used in medicines or as detergents. Methods: Generally, most of the native extracellular proteins, such as nattokinase from Bacillus subtilis, are lysed by secretory proteases. One way for solving this problem is to employ other hosts for nattokinase production. For producing secretory form of nattokinase from Bacillus subtilis, different factors such as a suitable host, optimized media for the maximum enzyme activity and easy purification are important. Results: These factors are studied in this investigation. Escherichia coli BL21 (DE3), as a reliable host was selected for a high yield production of an extracellular recombinant nattokinase. A mature nattokinase gene from Bacillus subtilis 1023, was cloned in the expression vector pET22b by which the host was transformed. The recombinant nattokinase was expressed through induction with IPTG. The expressed protein was confirmed by SDS-PAGE, and its fibrinolytic activity was assayed on the fibrin plates. Afterwards, the enzyme was purified by Ni-NTA native affinity column. Different media components were evaluated for maximum nattokinase production and activity. The highest enzyme activity of 883.107 U/ml was obtained, when a medium approximately consisting of yeast extract (4.38 g/L), tryptone (4 g/L), K2HPO4 (1.61 g/L) and CaCl2 (0.01 g/L) was used. Conclusion: Entrapping the transformed host in calcium alginate could lead to more enzyme activity and decrease media cost.

Background: Fractalkine (FKN) in its free and membrane bound-forms and its receptor CX3CR1are reported to have an atherosclerotic effect. The relationship of Single Nucleotide Polymorphisms (SNPs) in FKN and CX3CR1genes with the Coronary Artery Disease (CAD) risk showed conflicting results in different populations. The aim of this study was to investigate the influence of CX3CR1 threonine 280 methionine (T280M) polymorphism in the predisposition of Acute Coronary Syndrome (ACS) in Egyptians. Methods: 200 Egyptian subjects were recruited for the study. They were divided into 100 ACS patients and 100 healthy controls. Genotyping of CX3CR1 T280M was performed using a Polymerase Chain Reaction-restriction Fragment Length Polymorphism (PCR-RFLP). Serum FKN was assayed by Enzyme - Linked - Immuno- Sorbent-Assay (ELISA). Results: T and M allele frequencies for CX3CR1gene were not significantly different between ACS and Controls (p=0.76). Moreover, none of the genotypes had an atheroprotective effect. Serum analysis showed higher levels of FKN in ACS patients (p=0.041). FKN levels were not significantly different among genotypes of control and ACS groups (p=0.34) and (p=0.38) respectively. Conclusion: This study shows that CX3CR1 T280M polymorphism does not affect the incidence of ACS the Egyptian population. Moreover, none of the genotypes were associated with higher FKN levels.

Background: Exosome-like nanovesicles are biological nanostructures mediating cell-tocell communication and capable to load selected cargos also in the interaction among different species. Objective: We aimed to explore the content of exosome-like nanovesicles derived from Citrus limon L. and to analyze the effects of their uptake on human cells. Method: We isolated exosome-like nanovesicles from Citrus limon L. juice (EXO-CLs) by differential centrifugation. EXO-CLs were analyzed for short RNA content by advanced sequencing technologies, and for ascorbic acid (vitamin C) and citrate content by enzymatic assays. EXO-CLs anti-oxidant and pro-differentiative potential was evaluated in vitro on mesenchymal stromal cells (MSC), a common tool for regenerative strategies for several human tissues. Results: We showed that EXO-CLs carry detectable amounts of citrate and vitamin C and, although it was not possible to identify specific miRNAs, we detected short RNA sequences (20-30 bp) with unknown functions and with different distribution size in respect to whole Citrus limon L. juice. In vitro, EXO-CLs were uptaken by MSC and had a significant protective effect against oxidative stress. Furthermore, regarding the potential benefit for human bone health, we found that EXO-CLs modulate MSC differentiation versus the osteogenic lineage. Conclusion: We demonstrated that incubation with EXO-CLs exert antioxidant activity in human cells. This is most likely due to the direct delivery and uptake of micronutrients by human cells that are well preserved inside the nanovesicle membrane, including the unstable vitamin C. Based on our results, we speculate that fruit-derived nanovesicles have the potential to mediate interspecies influence after food intake.

Background: Rheumatoid Arthritis (RA) is a chronic autoimmune disease that results in the systemic inflammation principally affecting the capsule covering the articulating ends of the synovial joints. Pharmacological treatment involving analgesics and anti-inflammatory drugs including steroids suppresses the symptoms and has no effect on disease progression. However, disease modifying anti rheumatic drugs (DMARD) used for the treatment were still analysed for their long-term effects. Methods: Bromelain has been widely used as phytotherapeutic drug owing to its anti-inflammatory, analgesic, anti-tumor and fibrinolytic properties. Bromelain refers to the combination of thiol proteases available in the extract of Ananas comosus. The fibrinolytic property confers to the reduced pannus development and hence the prevention of disease progression. Results: It had been inferred that the observed clinical significance may not be solely accounted for its proteolytic property but also may be due to its hormone-like behaviour (i.e.) non-canonical interactions to initiate the signal transduction pathway. The hormone-like behaviour has been studied in cell models, suggesting that bromelain acts at system level. In the present study, molecular behaviour of the wild-type and mutant proteins has been studied by simulating the predicted structure in an aqueous system. The comparative study of the mutants revealed that the mutant with both C26A and H158F mutations has the similar surface properties compared to the other mutants and can be used in studying the non-enzymatic interactions. Conclusion: Thus, this study may prove to be a tool in experimental studies to understand the hormone-like behaviour and in the construction of oral immunogenic synthetic peptides for treating inflamed conditions.

Background: Bovine Parainfluenza Virus type 3 (BPIV3) is a major but often overlooked pathogen that causes respiratory disease in cattle, especially during transportation and in feedlot situations. There is a demand for the rapid detection and serological diagnosis of BPIV3 to monitor the presence of the virus and its antibodies in cattle, which is critical in designing suitable interventions and control. Methods: In the present study, ssDNA aptamers with high affinity and specificity against the HN protein of BPIV3 were selected using microplates as the matrix. Results: After eleven rounds selection, thirty-four different DNA sequences were obtained in total, wherein w-32, w-33, and w-34 were repeated seven, eleven, and nine times, and with Kd values of 56.57 ± 2.7 nM, 24.64 ± 2.84 nM, and 31.3 ± 3.32 nM, respectively. Two-dimensional structural analysis showed that the three aptamers had several loop structures that were probably more energetically favorable for target binding. Of the three candidates, aptamer w-33 showed the best affinity in an indirect enzyme-linked aptamer assay (ELAA). The percent inhibition cutoff value of the ELAA, assessed using twenty negative sera, was 31%. Conclusion: In a comparative study with commercial ELISA kits, the positive detection rate of the ELAA was slightly higher than that of the commercial ELISA kits, and the coincidence rate of ELAA and ELISA was 88%. Further optimization of the ELAA method with more serums is needed.

Objective: We studied direct effects of Erythropoietin (Epo) on functional properties of human monocytes/macrophages (Mc/Mphs) in vitro. Methods: Cells expressing CD14 marker were isolated from human peripheral blood mononuclear cells (PBMCs) by positive magnetic separation. Mc/Mphs were cultured without or with bacterial lipopolysaccharide (LPS) in the absence or presence of Epo for 24 h. Results: We showed that Epo treatment hoticeably reduces the percentages of CD14+ cells, CD124 (alpha subunit of IL-4 receptor)+ cells and CD197 (CCR7)+ cells in non-activated Mph cultures without affecting the levels of CD16 (low-affinity Fc-receptor)+ and CD119 (interferon-γ (IFN-γ) receptor)+ cells. Epo also markedly reduced percentages of CD197+ cells in LPS-activated Mc/Mphs, without significantly affecting the expression of all other molecular markers studied. In addition, Epo caused moderate up-regulation of interleukin-1β (IL-1β) and IL-6 production in resting Mc/Mph cultures, as compared to the down-regulation of IL-1β and IL-6 production in LPS-activated cells. No Epomediated effects on tumor necrosis factor-α (TNF-α) and IL-10 production were observed. Conclusion: Our data suggests that Epo effects on Mph functionality are largely dependent on the baseline activation status of these cells, and that Epo exerts no distinct direct effects on the particular Mph polarization pathway.

Background: Large DNA poxviruses encode a diverse family of secreted proteins that modulate host inflammatory and antiviral responses, in particular by inhibiting one of the key players of the mammalian immune system, the tumor necrosis factor (TNF). Methods: We investigated the effects of a recombinant variola (smallpox) virus TNF-decoy receptor (VARV-CrmB) in a murine model of contact dermatitis. Our results demonstrate that the VARV-CrmB protein significantly reduces the 2,4-dinitrochlorbenzene (DNCB)-induced migration of skin leukocytes during the sensitization phase and suppresses ear oedema during the elicitation phase of the contact reaction. Results: Studies focusing on the bone marrow hematopoiesis in the contact dermatitis model revealed that the epicutaneous co-application of DNCB and VARV-CrmB protein normalized the DNCBinduced effects to control levels. Conclusion: As an effective TNF antagonist, the VARV-CrmB protein might be conceived as a beneficial candidate for further research and development of therapeutic approaches in the field of the inflammatory skin diseases.

Background: Benefits of vitamin K have been reported by many studies recently, due to its ability to reduce the risk of cardiovascular diseases and its potential benefits against osteoporosis. Specifically, menaquinone-7 (MK-7), being the most potent form of vitamin K, has definitely received most of the attention. Currently, solid or static liquid fermentation strategies are utilized for industrial production of MK-7 by Bacillus strains. However, these strategies face fundamental operational and scale-up issues as well as intense pellicle and biofilm formations which is problematic in static liquid fermentation, due to heat and mass transfer inefficiencies they create. Objective: The purpose of this study was to demonstrate that biofilm reactors will overcome the issues associated with suspended cell reactors when using Bacillus strains to produce MK-7. The expectation is that the use of biofilm reactors will result in a significant increase in the production of MK-7. Method: Vitamin K production by Bacillus subtilis natto when grown in a biofilm reactor was evaluated at various concentrations of the three major nutrients, glucose, yeast extract and casein. The data was analyzed using response surface methodology (RSM). Results: The maximum concentration of MK-7 in the biofilm reactors was 20.5±0.5 mg/L, which was a 344 % increase when compared to the amount produced in suspended-cell reactors containing the same optimum media composition. Conclusion: These results demonstrate the potential of utilizing biofilm reactors for MK-7 production on an industrial scale.

Background: Glutathione transferases (GSTs) catalyze the conjugation of glutathione (GSH) to endogenous and xenobiotic electrophilic compounds and have been involved in the development of resistance toward cancer chemotherapeutic drugs and in the etiology, pathology and progression of several other diseases. In the present work, the human isoenzyme GSTA1-1 (hGSTA1-1) was used to assemble a microplate-based platform for high-throughput screening of natural productbased inhibitors from plant extracts. Methods: The enzyme was immobilized using sol-gel chemistry and deposited as a layer at the bottom surface of 96-well format ELISA microplate. The sensing signal was based on the inhibition of the colorimetric reaction between 1-chloro-dinitrobenzene (CDNB) and GSH, catalyzed by the sol-gel entrapped enzyme. Results: As a proof of concept, the system was used for screening aqueous extracts from medicinal and aromatic plants with excellent reproducibility (approximately 95%). Conclusion: The operational simplicity and accuracy of this system, suggest that it can be explored as a bioanalytical tool with potential use in drug design and development efforts for finding new sources of GST inhibitors useful in chemomodulation of cancer drugs.