9 research outputs found
Adipose-Derived Stem Cells Stimulate Regeneration of Peripheral Nerves: BDNF Secreted by These Cells Promotes Nerve Healing and Axon Growth De Novo
Transplantation of adipose-derived mesenchymal stem cells (ASCs) induces tissue regeneration by accelerating the growth of blood vessels and nerve. However, mechanisms by which they accelerate the growth of nerve fibers are only partially understood. We used transplantation of ASCs with subcutaneous matrigel implants (well-known in vivo model of angiogenesis) and model of mice limb reinnervation to check the influence of ASC on nerve growth. Here we show that ASCs stimulate the regeneration of nerves in innervated mice's limbs and induce axon growth in subcutaneous matrigel implants. To investigate the mechanism of this action we analyzed different properties of these cells and showed that they express numerous genes of neurotrophins and extracellular matrix proteins required for the nerve growth and myelination. Induction of neural differentiation of ASCs enhances production of brain-derived neurotrophic factor (BDNF) as well as ability of these cells to induce nerve fiber growth. BDNF neutralizing antibodies abrogated the stimulatory effects of ASCs on the growth of nerve sprouts. These data suggest that ASCs induce nerve repair and growth via BDNF production. This stimulatory effect can be further enhanced by culturing the cells in neural differentiation medium prior to transplantation
Antimicrobial Activity of Microorganisms Isolated from Ant Nests of Lasius niger
In this study, the microbial communities of two nests of black garden ants (Lasius niger) in the hollows of stem branches of old apple trees were found to have similar species compositions: each community contained representatives of three species from the Bacillaceae family and one species of actinomycetes from the genus Streptomyces. In total, four types of bacilli and two actinomycetes were isolated. Actinomycetes were identified as Streptomyces antibioticus-like and Streptomyces sp. None of the bacilli had antibiotic activity, whereas both streptomycetes produced antibiotics that inhibited the growth of Gram-positive bacteria in vitro, including isolates from their community. Antibiotic compounds of S. antibioticus-like strain INA 01148 (Institute of New Antibiotics) were identified as actinomycin D and its closest homologue, actinomycin A. Actinomycins presumably change the microbial community of the ant nest substrate as they act against Gram-positive bacteria and against fungi and Gram-negative bacteria. The antibiotic activity of the isolated Streptomyces sp. INA 01156 is of interest, since the substances produced by this strain inhibit the growth of drug-resistant bacteria, including methicillin-resistant Staphylococcus aureus INA 00761 (MRSA) and vancomycin-resistant strain Leuconostoc mesenteroides VKPM B-4177 (VR) (VKPM–National Collection of Industrial Microorganisms (Russian acronym))
Influence of PHA Substrate Surface Characteristics on the Functional State of Endothelial Cells
The needs of modern regenerative medicine for biodegradable polymers are wide and varied. Restoration of the viability of the vascular tree is one of the most important components of the preservation of the usefulness of organs and tissues. The creation of vascular implants compatible with blood is an important task of vascular bioengineering. The function of the endothelial layer of the vessel, being largely responsible for the development of thrombotic complications, is of great importance for hemocompatibility. The development of surfaces with specific characteristics of biomaterials that are used in vascular technologies is one of the solutions for their correct endothelialization. Linear polyhydroxyalkanoates (PHAs) are biodegradable structural polymeric materials suitable for obtaining various types of implants and tissue engineering, having a wide range of structural and physicomechanical properties. The use of PHA of various monomeric compositions in endothelial cultivation makes it possible to evaluate the influence of material properties, especially surface characteristics, on the functional state of cells. It has been established that PHA samples with the inclusion of 3-hydroxyhexanoate have optimal characteristics for the formation of a human umbilical vein endothelial cell, HUVEC, monolayer in terms of cell morphology as well as the levels of expression of vinculin and VE-cadherin. The obtained results provide a rationale for the use of PHA copolymers as materials for direct contact with the endothelium in vascular implants
Antibiotic Activity of Actinobacteria from the Digestive Tract of Millipede <i>Nedyopus dawydoffiae</i> (Diplopoda)
Because of the spread of drug resistance, it is necessary to look for new antibiotics that are effective against pathogenic microorganisms. The purpose of this study was to analyse the species composition of actinobacteria isolated from the digestive tract of the millipedes Nedyopus dawydoffiae and to determine their antimicrobial properties. Species identification was carried out on the basis of the morphological and culture properties and the sequence of the 16S rRNA gene. Actinobacteria were grown in different liquid media. Antibiotic properties were determined against some Gram-positive and Gram-negative bacteria as well as fungi. Of the 15 isolated strains, 13 have antibiotic activity against Gram-positive bacteria (including methicillin-resistant Staphylococcus aureus—MRSA) and fungi, but there was no antibiotic activity against Gram-negative test strains Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. It was established that antibiotic-producing actinobacteria belong to eight species of the genus Streptomyces. Depending on the nutrient medium, actinobacteria demonstrate different antimicrobial activities. As an example, S. hydrogenans shows that even strains selected in one population differ by the range of antimicrobial activity and the level of biosynthesis. Since the antibiotic production is considered as a feature for species competition in the microbiota community, the variability of antibiotic production among different strains of the same species is an adaptive characteristic for the competition in millipedes’ digestive tract community
Isolation and Characterization of a Novel Hydrophobin, Sa-HFB1, with Antifungal Activity from an Alkaliphilic Fungus, Sodiomyces alkalinus
The adaptations that alkaliphilic microorganisms have developed due to their extreme habitats promote the production of active natural compounds with the potential to control microorganisms, causing infections associated with healthcare. The primary purpose of this study was to isolate and identify a hydrophobin, Sa-HFB1, from an alkaliphilic fungus, Sodiomyces alkalinus. A potential antifungal effect against pathogenic and opportunistic fungi strains was determined. The MICs of Sa-HFB1 against opportunistic and clinical fungi ranged from 1 to 8 µg/mL and confirmed its higher activity against both non- and clinical isolates. The highest level of antifungal activity (MIC 1 µg/mL) was demonstrated for the clinical isolate Cryptococcus neoformans 297 m. The hydrophobin Sa-HFB1 may be partly responsible for the reported antifungal activity of S. alkalinus, and may serve as a potential source of lead compounds, meaning that it can be developed as an antifungal drug candidate
Using the Eurotium cristatum Fungus for Preparing Fermented Herbal Teas
Background: The biological activities of dark Chinese teas are largely due to their microbial post-fermentation. Herbal teas are traditional Russian beverages that hold special value, owing to their taste and useful medicinal properties. However, no data are available in the literature on using microbial post-fermentation for enhancing their biological activity. The goal of this work was to demonstrate that the fungus Eurotium isolated from Chinese black teas can be used for the post-fermentation of herbal teas produced from bay willow and apple leaves.Methods: Eurotium cristatum was isolated from brick Chinese tea Fujan and identified using conventional methods of microbiology and molecular biology. Low molecular weight metabolites (phenols, amines, sugars, and amino acids) were determined by HPLC. E. cristatum was grown in association with the bacterium Bacillus amyloliquefaciens.Results: It was revealed to exhibit valuable biosynthetic features, such as a lack of mycotoxins, zero antimicrobial activity, and the capacity to synthesize neuroactive amines. B. amyloliquefaciens displayed a wide spectrum of antibiotic (antimicrobial and antifungal) activities that anifested themselves even with antibiotic-resistant bacteria). While growing on green unfermented tea (Camellia sp.) E. cristatum produced and modified neuroactive amines, such as dopamine, serotonin, and epinephrine. The fungus efficiently grew during the post-fermentation of herbal teas from both bay willow and apple leaves. Even though Camellia leaves substantially differed from bay willow and apple leaves in terms of phenol content, the growth of E. cristatum on Camellia was also sufficiently good. This suggests that the growth of Eurotium fungi is not influenced by the phenolic compounds. The data obtained on the composition of phenolic compounds, carbohydrates, and amino acids in the fermented plants and raw material provide evidence that the growth of the fungus proceeds depends on the hydrolysis of high molecular weight phenols and cell biopolymers in the fermented material.Conclusion: Thus, the ability of E. cristatum to grow on plant leaves of significantly different biochemical composition provides foundations for new technologies aiming to obtain post-fermented herbal teas with high biological activity that are enriched in low molecular weight compounds including biogenic amines
Exploring Peptaibol’s Profile, Antifungal, and Antitumor Activity of Emericellipsin A of <i>Emericellopsis</i> Species from Soda and Saline Soils
Features of the biochemical adaptations of alkaliphilic fungi to exist in extreme environments could promote the production of active antibiotic compounds with the potential to control microorganisms, causing infections associated with health care. Thirty-eight alkaliphilic and alkalitolerant Emericellopsis strains (E. alkalina, E. cf. maritima, E. cf. terricola, Emericellopsis sp.) isolated from different saline soda soils and belonging to marine, terrestrial, and soda soil ecological clades were investigated for emericellipsin A (EmiA) biosynthesis, an antifungal peptaibol previously described for Emericellopsis alkalina. The analysis of the Emericellopsis sp. strains belonging to marine and terrestrial clades from chloride soils revealed another novel form with a mass of 1032.7 Da, defined by MALDI-TOF Ms/Ms spectrometers, as the EmiA lacked a hydroxyl (dEmiA). EmiA displayed strong inhibitory effects on cell proliferation and viability of HCT 116 cells in a dose- and time-dependent manners and induced apoptosis