Decreased Levels of Chaperones in Mucopolysaccharidoses and Their Elevation as a Putative Auxiliary Therapeutic Approach.

Mucopolysaccharidoses (MPS) are rare genetic disorders belonging to the lysosomal storage diseases. They are caused by mutations in genes encoding lysosomal enzymes responsible for degrading glycosaminoglycans (GAGs). As a result, GAGs accumulate in lysosomes, leading to impairment of cells, organs and, consequently, the entire body. Many of the therapies proposed thus far require the participation of chaperone proteins, regardless of whether they are therapies in common use (enzyme replacement therapy) or remain in the experimental phase (gene therapy, STOP-codon-readthrough therapy). Chaperones, which include heat shock proteins, are responsible for the correct folding of other proteins to the most energetically favorable conformation. Without their appropriate levels and activities, the correct folding of the lysosomal enzyme, whether supplied from outside or synthesized in the cell, would be impossible. However, the baseline level of nonspecific chaperone proteins in MPS has never been studied. Therefore, the purpose of this work was to determine the basal levels of nonspecific chaperone proteins of the Hsp family in MPS cells and to study the effect of normalizing GAG concentrations on these levels. Results of experiments with fibroblasts taken from patients with MPS types I, II, IIIA, IIIB, IIIC, IID, IVA, IVB, VI, VII, and IX, as well as from the brains of MPS I mice (Idua-/-), indicated significantly reduced levels of the two chaperones, Hsp70 and Hsp40. Interestingly, the reduction in GAG levels in the aforementioned cells did not lead to normalization of the levels of these chaperones but caused only a slight increase in the levels of Hsp40. An additional transcriptomic analysis of MPS cells indicated that the expression of other genes involved in protein folding processes and the cell response to endoplasmic reticulum stress, resulting from the appearance of abnormally folded proteins, was also modulated. To summarize, reduced levels of chaperones may be an additional cause of the low activity or inactivity of lysosomal enzymes in MPS. Moreover, this may point to causes of treatment failure where the correct structure of the enzyme supplied or synthesized in the cell is crucial to lower GAG levels.

Antibacterial, Antifungal and Anticancer Activities of Compounds Produced by Newly Isolated Streptomyces Strains from the Szczelina Chocholowska Cave (Tatra Mountains, Poland).

Resistance of bacteria, fungi and cancer cells to antibiotics and other drugs is recognized as one of the major problems in current medicine. Therefore, a search for new biologically active compounds able to either kill pathogenic cells or inhibit their growth is mandatory. Hard-to-reach habitats appear to be unexplored sources of microorganisms producing previously unknown antibiotics and other molecules revealing potentially therapeutic properties. Caves belong to such habitats, and Actinobacteria are a predominant group of microorganisms occurring there. This group of bacteria are known for production of many antibiotics and other bioactive compounds. Interestingly, it was demonstrated previously that infection with bacteriophages might enhance production of antibiotics by them. Here, we describe a series of newly isolated strains of Actinobacteria that were found in caves from the Tatra Mountains (Poland). Phage induction tests indicated that some of them may bear active prophages able to produce virions upon treatment with mitomycin C or UV irradiation. Among all the examined bacteria, two newly isolated Streptomyces sp. strains were further characterized to demonstrate their ability to inhibit the growth of pathogenic bacteria (strains of Staphylococcus aureus, Salmonella enterica, Enterococcus sp., Escherichia coli, and Pseudomonas aeruginosa) and fungi (different species and strains from the genus Candida). Moreover, extracts from these Streptomyces strains reduced viability of the breast-cancer cell line T47D. Chemical analyses of these extracts indicated the presence of isomers of dichloranthrabenzoxocinone and 4,10- or 10,12-dichloro-3-O-methylanthrabenzoxocinone, which are putative antimicrobial compounds. Moreover, various previously unknown (unclassified) molecules were also detected using liquid chromatography-mass spectrometry, suggesting that tested Streptomyces strains may synthesize a battery of bioactive compounds with antibacterial, antifungal, and anticancer activities. These results indicate that further studies on the newly isolated Actinobacteria might be a promising approach to develop novel antibacterial, antifungal, and/or anticancer drugs.

Unexplored potential: Biologically active compounds produced by microorganisms from hard-to-reach environments and their applications.

Rapid development of antibiotic resistance of bacteria and fungi, as well as cancer drug resistance, has become a global medical problem. Therefore, alternative methods of treatment are considered. Studies of recent years have focused on finding new biologically active compounds that may be effective against drug-resistant cells. High biodiversity of hard-to-reach environments offers sources to search for novel molecules potentially applicable for medical purposes. In this review article, we summarize and discuss compounds produced by microorganisms from hot springs, glaciers, caves, underground lakes, marine ecosystems, and hydrothermal vents. Antibacterial, antiviral, antifungal, anticancer, anti-inflammatory, and antioxidant potential of these molecules are presented and discussed. We conclude that using compounds derived from microorganisms occurring in extreme environments might be considered in further studies on development of treatment procedures for diseases caused by drug-resistant cells.

Potential of genistein-induced autophagy in the treatment of neurodegenerative diseases / Potencjal autofagii indukowanej przez genisteine w leczeniu chorób neurodegeneracyjnych.

Development of therapies for neurodegenerative diseases, disorders characterized by progressing loss of neurons, is a great challenge for current medicine. Searching for drugs for these diseases is being proceeded in many laboratories in the world. To date, several therapeutical strategies have been proposed which, however, are either of insufficient efficacy or at the early preclinical stages. One of the newest concepts is elevated efficiency of degradation of protein aggregates which are causes of 70% of these diseases. Autophagy, i.e. lysosomal degradation of macromolecules, is a process which could be employed in such a strategy Searching for a compound which would not only stimulate autophagy but also reveal safety in a long-term usage and be able to cross the blood-brain-barrier led to studies on one of flavonoids, genistein which occurs at high concentrations in soy. Experiments with this compound indicated its enormous efficiency in removing protein aggregated formed by beta-amyloid, hyperphosphorylated tau protein, and mutant huntingtin. Moreover, using animal models of these diseases, correction of cognitive and motoric symptoms was demonstrated. Considering safety of genistein as well as its ability to crossing the blood-brain-barrier, one may assume that this molecule is a candidate for an effective drug in therapies of not only Alzheimer disease and Huntington disease, but also other disorders caused be protein aggregates. In this article, recent results of studies on the use of genistein in different models of neurodegenerative diseases are summarized, with special emphasis on its autophagy-dependent action.

The Role of Metabolites in the Link between DNA Replication and Central Carbon Metabolism in Escherichia coli.

A direct link between DNA replication regulation and central carbon metabolism (CCM) has been previously demonstrated in Bacillus subtilis and Escherichia coli, as effects of certain mutations in genes coding for replication proteins could be specifically suppressed by particular mutations in genes encoding CCM enzymes. However, specific molecular mechanism(s) of this link remained unknown. In this report, we demonstrate that various CCM metabolites can suppress the effects of mutations in different replication genes of E. coli on bacterial growth, cell morphology, and nucleoid localization. This provides evidence that the CCM-replication link is mediated by metabolites rather than direct protein-protein interactions. On the other hand, action of metabolites on DNA replication appears indirect rather than based on direct influence on the replication machinery, as rate of DNA synthesis could not be corrected by metabolites in short-term experiments. This corroborates the recent discovery that in B. subtilis, there are multiple links connecting CCM to DNA replication initiation and elongation. Therefore, one may suggest that although different in detail, the molecular mechanisms of CCM-dependent regulation of DNA replication are similar in E. coli and B. subtilis, making this regulation an important and common constituent of the control of cell physiology in bacteria.