Unknown Biological Activity Research Articles

Renoprotective Effects of Tanshinone IIA: A Literature Review

The kidney is an important organ in the human body, with functions such as urine production, the excretion of metabolic waste, the regulation of water, electrolyte and acid-base balance and endocrine release. The morbidity and mortality of kidney diseases are increasing year by year worldwide, and they have become a serious public health problem. In recent years, natural products derived from fungi, plants and animals have become an important alternative source of treatment for kidney diseases because of their multiple pathways, multiple targets, safety, low toxicity and few side effects. Tanshinone IIA (Tan IIA) is a lipid-soluble diterpene quinone isolated from the Chinese herb Salvia miltiorrhiza, considered as a common drug for the treatment of cardiovascular diseases. As researchers around the world continue to explore its unknown biological activities, it has also been found to have a wide range of biological effects, such as anti-cancer, anti-oxidative stress, anti-inflammatory, anti-fibrotic, and hepatoprotective effects, among others. In recent years, many studies have elaborated on its renoprotective effects in various renal diseases, including diabetic nephropathy (DN), renal fibrosis (RF), uric acid nephropathy (UAN), renal cell carcinoma (RCC) and drug-induced kidney injury caused by cisplatin, vancomycin and acetaminophen (APAP). These effects imply that Tan IIA may be a promising drug to use against renal diseases. This article provides a comprehensive review of the pharmacological mechanisms of Tan IIA in the treatment of various renal diseases, and it provides some references for further research and clinical application of Tan IIA in renal diseases.

In Vitro Study of Biological Activity of Tanacetum vulgare Extracts.

Tanacetum vulgare is an herbaceous plant widely used in folk medicine. It is rich in phenolic acids and flavonoids, which have pharmacological and medicinal properties, such as anthelmintic, antispasmodic, tonic, antidiabetic, diuretic, and antihypertensive. This study aimed to confirm the presence of biologically active substances in Tanacetum vulgare and to determine the pharmacological spectrum of biological activity of Tanacetum vulgare extract components. When preparing Tanacetum vulgare extracts, the highest yield was observed when using the maceration method with a mixture of solvents methanol + trifluoroacetic acid (22.65 ± 0.68%). The biologically active substances in Tanacetum vulgare extract samples were determined using high-performance liquid chromatography. Biologically active substances such as luteolin-7-glucoside (550.80 mg/kg), chlorogenic acid (5945.40 mg/kg), and rosmarinic acid (661.31 mg/kg) were identified. Their structures were determined. The experiments have confirmed the antioxidant and antibacterial activities. Secondary metabolites of Tanacetum vulgare extracts have been found to have previously unknown biological activity types; experimental confirmation of their existence will advance phytochemical research and lead to the development of new drugs.

Ammonia and Phosphine in the Clouds of Venus as Potentially Biological Anomalies

We are of the opinion that several anomalies in the atmosphere of Venus provide evidence of yet-unknown processes and systems that are out of equilibrium. The investigation of these anomalies on Venus should be open to a wide range of explanations, including unknown biological activity. We provide an overview of two anomalies, the tentative detection of ammonia and phosphine in Venus’s atmosphere. These anomalies fly in the face of the tacit assumption that the atmosphere of Venus must be in chemical redox equilibrium, an assumption connected to the belief that Venus is lifeless. We then discuss several major past discoveries in astronomy, biology and geology, which lead to the abandonment of certain assumptions held by many scientists as though they were well-established principles. The anomalies of ammonia and phosphine in the atmosphere of Venus are placed in the context of these historical discoveries. This context supports our opinion that persistence by the community in the exploration of these anomalies with a skeptical eye towards tacit assumptions will increase the chances of making profound discoveries about the atmosphere of Venus and the diverse and often strange nature of planetary environments. To be submitted to Aerospace Special Issue “The Search for Signs of Life on Venus: Science Objectives and Mission Designs”.

HPLC-MS/MS Oxylipin Analysis of Plasma from Amyotrophic Lateral Sclerosis Patients.

Oxylipins play a critical role in regulating the onset and resolution phase of inflammation. Despite inflammation is a pathological hallmark in amyotrophic lateral sclerosis (ALS), the plasma oxylipin profile of ALS patients has not been assessed yet. Herein, we develop an oxylipin profile-targeted analysis of plasma from 74 ALS patients and controls. We found a significant decrease in linoleic acid-derived oxylipins in ALS patients, including 9-hydroxy-octadecadienoic acid (9-HODE) and 13-HODE. These derivatives have been reported as important regulators of inflammation on different cell systems. In addition, some 5-lipoxygenase metabolites, such as 5-hydroxy- eicosatetraenoic acid also showed a significant decrease in ALS plasma samples. Isoprostanes of the F2α family were detected only in ALS patients but not in control samples, while the hydroxylated metabolite 11-HETE significantly decreased. Despite our effort to analyze specialized pro-resolving mediators, they were not detected in plasma samples. However, we found the levels of 14-hydroxy-docosahexaenoic acid, a marker pathway of the Maresin biosynthesis, were also reduced in ALS patients, suggesting a defective activation in the resolution programs of inflammation in ALS. We further analyze oxylipin concentration levels in plasma from ALS patients to detect correlations between these metabolites and some clinical parameters. Interestingly, we found that plasmatic levels of 13-HODE and 9-HODE positively correlate with disease duration, expressed as days since onset. In summary, we developed a method to analyze “(oxy)lipidomics” in ALS human plasma and found new profiles of metabolites and novel lipid derivatives with unknown biological activities as potential footprints of disease onset.

Escherichia coli-Derived γ-Lactams and Structurally Related Metabolites Are Produced at the Intersection of Colibactin and Fatty Acid Biosynthesis.

Colibactin is a genotoxic hybrid polyketide-nonribosomal peptide that drives colorectal cancer initiation. While clinical data suggest colibactin genotoxicity in vivo is largely caused by the major DNA-cross-linking metabolite, the colibactin locus produces a diverse collection of metabolites with mostly unknown biological activities. Here, we describe 10 new colibactin pathway metabolites (1-10) that are dependent on its α-aminomalonyl-carrier protein. The most abundant metabolites, 1 and 2, were isolated and structurally characterized mainly by nuclear magnetic resonance spectroscopy to be γ-lactam derivatives, and the remaining related structures were inferred via shared biosynthetic logic. Our proposed formation of 1-10, which is supported by stereochemical analysis, invokes cross-talk between colibactin and fatty acid biosynthesis, illuminating further the complexity of this diversity-oriented pathway.

Short carboxyl terminal parathyroid hormone peptides modulate human parathyroid hormone signaling in mouse osteoblasts

BackgroundNovel human parathyroid hormone (hPTH) peptides of unknown biological activity have recently been identified in the serum of subjects with normal renal function, chronic renal failure, and end-stage renal disease through the application of liquid chromatography-high resolution mass spectrometry. Purposeof experiments: To determine the bioactivity of these peptides, we synthesized hPTH28-84, hPTH38-84, and hPTH45-84 peptides by solid phase peptide synthesis and tested their bioactivity in MC3T3-E1 mouse osteoblasts, either individually or together with the native hormone, hPTH1-84, by assessing the accumulation of 3´,5´-cyclic adenosine monophosphate (cAMP) and the induction of alkaline phosphatase activity. ResultsIncreasing doses of hPTH1-84 (1–100 nM) increased the accumulation of cAMP and alkaline phosphatase activity in osteoblasts. hPTH28-84, hPTH38-84, and hPTH45-84 in concentrations of 1–100 nM were biologically inert. Surprisingly, 100 nM hPTH38-84 and hPTH45-84 increased the accumulation of cAMP in osteoblasts treated with increasing amounts of hPTH1-84. Human PTH28-84 had no effects on cAMP activity alone or in combination with hPTH1-84. Conversely, 100 nM hPTH38-84, hPTH45-84, and hPTH28-84 blocked the activation of alkaline phosphatase activity by hPTH1-84. ConclusionsThe data show that the short carboxyl-terminal hPTH peptides, hPTH38-84 and hPTH45-84, increase the amount of cellular cAMP generated in cultured osteoblasts in response to treatment with full-length hPTH1-84 when compared to full-length hPTH1-84 alone. Human PTH28-84 had no effect on cAMP activity alone or in combination with hPTH1-84. Human PTH28-84, hPTH38-84 and hPTH45-84 reduced the effects of hPTH1-84 in osteoblasts with respect to the induction of alkaline phosphatase activity compared to hPTH1-84 alone. Short carboxyl peptides of human PTH are biologically inert but when administered together with full-length hPTH1-84 modulate the bioactivity of hPTH1-84 in osteoblasts.

Chemometric methods in antimalarial drug design from 1,2,4,5-tetraoxanes analogues

ABSTRACT A set of 23 steroidal 1,2,4,5-tetraoxane analogues were studied using quantum-chemical method (B3LYP/6-31 G*) and multivariate analyses (PCA, HCA, KNN and SIMCA) in order to calculate the properties and correlate them with antimalarial activity (log RA) against Plasmodium falciparum clone D-6 from Sierra Leone. PCA results indicated 99.94% of the total variance and it was possible to divide the compounds into two classes: less and more active. Descriptors responsible for separating were: highest occupied molecular orbital energy (HOMO), bond length (O1-O2), Mulliken electronegativity (χ) and Bond information content (BIC0). We use HCA, KNN and SIMCA to explain relationships between molecular properties and biological activity of a training set and to predict antimalarial activity (log RA) of 13 compounds (#24-36) with unknown biological activity. We apply molecular docking simulations to identify intermolecular interactions with a selected biological target. The results obtained in multivariate analysis aided in the understanding of the activity of the new compound's design (#24-36). Thus, through chemometric analyses and docking molecular study, we propose theoretical synthetic routes for the most promising compounds 28, 30, 32 and 36 that can proceed to synthesis steps and in vitro and in vivo assays.

The Therapeutic Effect of Artemisinin and Its Derivatives in Kidney Disease.

Artemisinin (ARS) and its derivatives (ARSs) are recommended as the first-line antimalarial drugs for the treatment of malaria. Besides antimalarial function, its potent anti-inflammatory and immunoregulatory properties, as well as the ability to regulate oxidative stress have brought them to a prominent position. As researchers around the world are continually exploring the unknown biological activities of ARS derivatives, experimental studies have shown much progress in renal therapy. This review aims to give a brief overview of the current research on ARSs applications for kidney treatment with the evaluation of therapeutic properties and potential molecular mechanisms.

Development and application of a LC–MS/MS assay for simultaneous analysis of 25-hydroxyvitamin-D and 3-epi-25-hydroxyvitamin-D metabolites in canine serum

Hypovitaminosis D and hypervitaminosis D are well recognised disorders in dogs. Hypovitaminosis D can occur following consumption of a diet inadequately supplemented with vitamin D or as a sequelae of severe intestinal disease. Hypervitaminosis D may occur as a result of consuming proprietary dog foods over-supplemented with vitamin D or through ingestion of vitamin D containing medicinal products or rodenticides. Consequently, there is a clear need to establish a methodology that can accurately quantify vitamin D metabolites across a broad dynamic range in dogs. The existence of C3-epimers of vitamin D metabolites has yet to be elucidated in dogs, yet are known to interfere with the analysis of vitamin D and have unknown biological activity in other species. Here, we describe the development and validation of a sensitive, specific and robust analytical liquid chromatography tandem mass spectrometry (LC–MS/MS) assay capable of separating and accurately measuring 25-hydroxyvitamin-D2/3 (25(OH)D2/3) and 3-epi-25-hydroxyvitamin-D2/3 (3-epi-25(OH)D2/3). We describe a simplified workflow utilising supported liquid extraction (SLE) without derivatization that provides good linearity (mean r > 0.996) and accuracy across a broad dynamic range of 4–500 nmol/L for D3 metabolites and 7.8–500 nmol/L for D2 metabolites. Upon application of this assay to 117 canine serum samples, 25(OH)D3 was detectable in all samples with a median concentration of 82.1 nmol/L (inter-quartile range (IQR) 59.7–101.8 nmol/L). 3-epi-25(OH)D3 could be detected in 87.2 % of the study population, with a median concentration of 5.2 nmol/L (2.4–8.1 nmol/L). However, 3-epi-25(OH)D3 was quantified below the LLOQ in 40.2 % of these samples. 3-epi-25(OH)D3 contributed on average 6.3 % to 25(OH)D3 status (contribution ranges from 0 to 23.8%) and a positive correlation was detected between 25(OH)D3 and 3-epi-25(OH)D3 concentrations. Free 25(OH)D was also measured using an immunoassay with a median concentration of 15.2 pmol/L (12.5–23.2 pmol/L), and this metabolite was also positively correlated to both 3-epi-25(OH)D3 and 25(OH)D3 concentrations. D2 metabolites were not detected in canine serum as expected. Vitamin D metabolite concentrations were variable between individuals, and research into the causes of this variation should include factors such as breed, age, sex and neuter status to determine the impact of genetic and hormonal factors. Given the clinical importance of vitamin D in dogs, and the immense potential for utilising this species as a model for human disease, further elucidation of the vitamin D pathway in this species would provide immense clinical and research benefit.

The Modern Use of an Ancient Plant: Exploring the Antioxidant and Nutraceutical Potential of the Maltese Mushroom (Cynomorium Coccineum L.).

In the continuous scientific search for new safe and effective drugs, there has recently been a rediscovery of natural substances as a potential reservoir of innovative therapeutic solutions for human health, with the prospect of integrating with and sometimes replacing conventional drugs. Cynomorium coccineum subsp. coccineum is a holoparasitic plant well known in ethnopharmacology, although its current use as a curative remedy is reported only in some ethnic groups of North Africa and the Arabian Peninsula. Often known as ‘Maltese mushroom’ due to its unique appearance and the absence of chlorophyll, C. coccineum is present in almost all of the Mediterranean Basin. It is only recently that a few research groups have begun to look for confirmation of some of its traditional uses to highlight previously unknown biological activities. Here, we review the recent scientific findings on the plant’s phytochemistry and the most significant descriptions of some of its antioxidant and biological activities (antimicrobial, anticancer, pro-erectile, and anti-tyrosinase enzyme) both in vivo and in vitro. Some of these may be promising from the perspective of food and cosmetic formulations. The purpose of this review is to provide an initial impetus to those who, in the foreseeable future, will want to increase the knowledge and possible applications of this plant full of history, charm, and mystery.

Abstract 3676: Novel tumor suppressive role of Peptidylarginine deiminase IV involving cancer stem cell regulation in breast cancer models

Abstract Breast cancer accounts for >500,000 deaths annually worldwide. Despite therapeutic advances, treated patients often relapse with metastases. Emerging research indicates that relapse may be driven by a subpopulation of tumor cells termed cancer stem cells (CSCs), that are uniquely capable of self-renewal and have enhanced drug resistance. Understanding the properties of these CSCs is critical for development of more effective therapies. Peptidyl arginine deiminase 4 (PADI4) is an enzyme that catalyzes deimination of arginine to citrulline. Citrullination of histones modulates expression of key stem cell transcription factors in embryonic stem cells (Christophorou, et al., 2014, Nature 507:104), so we hypothesized that PADI4 could be involved in CSC regulation. We showed that PADI4 mRNA and protein are expressed at varying levels across a panel of breast cancer cell lines, and we knocked down PADI4 in two high expressing lines, MCF10Ca1h and MDAMB231-LM2. PADI4 knockdown did not alter tumor cell proliferation in vitro, but it enhanced migration and invasion and increased cell survival. Importantly, PADI4 knockdown increased clonogenicity and enhanced tumorsphere formation, suggesting that it specifically increases the CSC population. In vivo studies showed higher tumor initiation efficiency following PADI4 knockdown, and increased lung metastasis. PADI4 is predicted to have multiple isoforms with unknown biological activity that complicate PADI4 expression-based analysis in patient data sets. We circumvented this issue by pharmacologically inhibiting PADI4 in MCF10Ca1h to generate a transcriptomic signature reflecting PADI4 gene activity. This PADI4 gene activity signature was shown to correlate with lower tumor grade and better disease outcome in transcriptomic datasets from human ER+ breast cancers. In conclusion, our findings suggest that PADI4 functions as a tumor suppressor in breast cancer, in part through effects on the CSC. Citation Format: Humberto J. Ochoa, Nellie Moshkovich, Binwu Tang, Howard H. Yang, Maxwell P. Lee, Lalage M. Wakefield. Novel tumor suppressive role of Peptidylarginine deiminase IV involving cancer stem cell regulation in breast cancer models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 3676.

Chemical Instability and Promiscuity of Arylmethylidenepyrazolinone-Based MDMX Inhibitors.

Targeting the protein–protein interaction between p53 and MDM2/MDMX (MDM4) represents an attractive anticancer strategy for the treatment of p53-competent tumors. Several selective and potent MDM2 inhibitors have been developed and entered the clinic; however, the repertoire of MDMX antagonists is still limited. The arylmethylidenepyrazolinone SJ-172550 has been reported as a selective MDMX antagonist; yet, uncertainties about its mechanism of action have raised doubts about its use as a chemical probe. Here, we show that, in addition to its unclear mode of action, SJ-172550 is unstable in aqueous buffers, giving rise to side products of unknown biological activity. Using an SJ-172550-derived affinity probe, we observed promiscuous binding to cellular proteins whereas cellular thermal shift assays did not reveal a stabilizing effect on MDMX. Overall, our results raise further questions about the interpretation of data using SJ-172550 and related compounds to investigate cellular phenotypes.

Effects of Caffeine Againts Expression on Mir-423-3p in Cell Lines Hep-G2

Introduction Coffee contains a wide range of chemical components with different characteristics, but there are still many unknown biological activity and its benefits to mankind in coffee compounds.1 Coffee consists of volatile and non-volatile compound that affect the aroma and quality of coffe

Towards an experimental classification system for membrane active peptides

Mature proteins can act as potential sources of encrypted bioactive peptides that, once released from their parent proteins, might interact with diverse biomolecular targets. In recent work we introduced a systematic methodology to uncover encrypted intragenic antimicrobial peptides (IAPs) within large protein sequence libraries. Given that such peptides may interact with membranes in different ways, resulting in distinct observable outcomes, it is desirable to develop a predictive methodology to categorize membrane active peptides and establish a link to their physicochemical properties. Building upon previous work, we explored the interaction of a range of IAPs with model membranes probed by differential scanning calorimetry (DSC) and circular dichroism (CD) techniques. The biophysical data were submitted to multivariate statistical methods and resulting peptide clusters were correlated to peptide structure and to their antimicrobial activity. A re-evaluation of the physicochemical properties of the peptides was conducted based on peptide cluster memberships. Our data indicate that membranolytic peptides produce characteristic thermal transition (DSC) profiles in model vesicles and that this can be used to categorize novel molecules with unknown biological activity. Incremental expansion of the model presented here might result in a unified experimental framework for the prediction of novel classes of membrane active peptides.

Metabolite profiling of ascidian Styela plicata using LC–MS with multivariate statistical analysis and their antitumor activity

To identify the metabolite distribution in ascidian, we have applied an integrated liquid chromatography–tandem mass spectrometry (LC–MS) metabolomics approach to explore and identify patterns in chemical diversity of invasive ascidian Styela plicata. A total of 71 metabolites were reported among these alkaloids, fatty acids and lipids are the most dominant chemical group. Multivariate statistical analysis, principal component analysis (PCA) showed a clear separation according to chemical diversity and taxonomic groups. PCA and partial least square discriminant analysis were applied to discriminate the chemical group of S. plicata crude compounds and classify the compounds with unknown biological activities. In this study, we reported for the first time that a partially purified methanol extract prepared from the ascidian S. plicata and Ascidia mentula possess antitumor activity against four tumor cell lines with different tumor histotype, such as HeLa (cervical carcinoma), HT29 (colon carcinoma), MCF-7 (breast carcinoma) and M14 (melanoma). S. plicata fraction SP-50 showed strong inhibition of cell proliferation and induced apoptosis in HeLa and HT29 cells, thus indicating S. plicata fraction SP-50 a potential lead compound for anticancer therapy. The molecular mechanism of action and chemotherapeutic potential of these ascidian unknown biomolecules need further research.

Current advances in ant venom proteins causing hypersensitivity reactions in the Asia-Pacific region.

The main insects causing allergy reactions to stinging insect in humans are Apidae (bees), Vespidae (wasps, yellow jackets and hornets) and Formicidae (ants). Their venom stings are composed of various biologically active peptides and protein components, some of which can cause toxicity or anaphylaxis in humans. The protein venom demonstrate some common allergenic activity such as for fire ants and vespids, which have two common allergens that are phospholipase A1 (enzymatic activity) and antigen 5 with unknown biological activity. The common allergens seem to share some degree of immunological cross-reactivity, particularly when the sequence homology is above 70%. Therefore immunotherapeutic approaches targeting more than one specific species are of interest. Recent widespread increases of various ant species in many countries have resulted in higher number of reported about serious allergic reactions to stings. Most insect-allergy related cases have been reported for species from Solenopsis, Myrmecia and Pachycondyla genera, and their stings can often result in human fatalities. In addition, stinging ants can have serious health effects on livestock, agricultural damage adversely affecting the biodiversity of the region. This review discusses the impact of important ant species on human health in the Asia-Pacific region along with the molecular immunological aspects of the identified venoms and current status of diagnostics and therapeutics.

Identification of black market products and potential doping agents in Germany 2010-2013.

The desire to increase the athletic performance, to 'optimize' an individual's appearance, and to complement but also to arguably substitute exercise by means of drugs and drug candidates has generated a considerable (illicit) market for compounds such as anabolic-androgenic steroids, stimulants, growth promoting peptide hormones, and so on. Genuinely developed for therapeutic use, their abuse/misuse generates enormous health risks, which has necessitated comprehensive controls of compound trafficking by customs and anti-doping authorities. From 2012 to 2013, the Bureau of Customs Investigation confiscated products containing anabolic-androgenic steroids (AAS; 259 kg), stimulants (13 kg), selective estrogen receptor modulators (SERMs; 24 kg), and human growth hormone (hGH; 3500 ampules). In cooperation with the Bureau and under the umbrella of the European Monitoring Center for Emerging Doping Agents (EuMoCEDA), the Cologne Anti-Doping Laboratory analyzed an additional 337 (black market) products between 2010 and 2013, allowing to monitor developments in drug use and, hence, the anticipation of new challenges in sports drug testing. Main tools utilized in characterizing confiscated materials were liquid chromatography-high resolution mass spectrometry (LC-HRMS), gas chromatography-high resolution mass spectrometry (GC-HRMS), and polyacrylamide gel electrophoresis (PAGE) with subsequent bottom-up identification of peptidic compounds using nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS). Among the 337 substances analyzed in the doping control laboratory in Cologne, 67 active ingredients were found, 49 of which being categorized as doping agents by the World Anti-Doping Agency (WADA). A total of 83.7 % accounted for steroidal substances (predominantly testosterone, trenbolone, and nandrolone and corresponding esters), 12.8 % accounted for peptide hormones and growth factors (predominantly hGH and growth hormone releasing peptides (GHRPs)), 3.2 % of the products contained hormones and metabolic modulators, and 0.3 % accounted for diuretic agents. Outstanding findings were the detection of the selective androgen receptor modulator (SARM) LGD-4033, the thymic hormone thymosin β4, and a fusion protein of unknown biological activity. Trafficking of considerable amounts of arguably performance and/or body-enhancing compounds has been observed during the past 4 years, the majority of which is categorized as relevant to sports drug testing. Several substances are of fake/non-approved nature and represent enormous health risks to the 'customer'.

Occurrence of pre- and post-harvest mycotoxins and other secondary metabolites in Danish maize silage.

Maize silage is a widely used feed product for cattle worldwide, which may be contaminated with mycotoxins, pre- and post-harvest. This concerns both farmers and consumers. To assess the exposure of Danish cattle to mycotoxins from maize silage, 99 samples of whole-crop maize (ensiled and un-ensiled) were analyzed for their contents of 27 mycotoxins and other secondary fungal metabolites by liquid chromatography-tandem mass spectrometry. The method specifically targets the majority of common pre- and post-harvest fungi associated with maize silage in Denmark. Sixty-one samples contained one or more of the 27 analytes in detectable concentrations. The most common mycotoxins were zearalenone, enniatin B nivalenol and andrastin A, found in 34%, 28%, 16% and 15% of the samples, respectively. None of the samples contained mycotoxins above the EU recommended maximum concentrations for Fusarium toxins in cereal-based roughage. Thus, the present study does not indicate that Danish maize silage in general is a cause of acute single mycotoxin intoxications in cattle. However, 31 of the samples contained multiple analytes; two samples as much as seven different fungal metabolites. Feed rations with maize silage may therefore contain complex mixtures of fungal secondary metabolites with unknown biological activity. This emphasizes the need for a thorough examination of the effects of chronic exposure and possible synergistic effects.

The use of fosmid metagenomic libraries in preliminary screening for various biological activities.

BackgroundIt is generally believed that there are many natural sources of as yet unknown bioactive compounds with a high biotechnological potential. However, the common method based on the use of cell extracts in the preliminary screening for particular molecules or activities is problematic as amounts of obtained compounds may be low, and such experiments are hardly reproducible. Therefore, the aim of this work was to test whether a novel strategy to search for previously unknown biological activities can be efficient. This strategy is based on construction of metagenomic libraries and employment of Escherichia coli strains as cell factories producing compounds of properties potentially useful in biotechnology.ResultsThree cyanobacterial metagenomic libraries were constructed in the fosmid system. The libraries were screened for various biological activities. Extracts from selected E. coli clones bearing constructs with fragments of cyanobacterial genomes revealed antimicrobial or anticancer activities. Interestingly, stimulation of growth of host bacteria bearing particular plasmids with certain cyanobacterial genes was detected, suggesting a potential possibility for improvement of E. coli cultivation during biotechnological production. The most interesting plasmids were sequenced, and putative mechanisms of biological effects caused by cyanobacterial gene products are discussed.ConclusionsThe strategy of exploring cyanobacteria as sources of bioactive compounds, based on E. coli cell factories producing compounds due to expression of genes from metagenomic libraries, appears to be effective.

Circulating Endothelial Progenitor Cells is a predictor in Atherosclerosis: Is it really a promising candle?

Circulating endothelial progenitor cells (CEPC) are supposed to be a subset of bone marrow-derived peripheral blood mononuclear cells (PBMC), revealing immature surface markers common to hematopoietic stem cells, such as CD 34 and CD 133 and endothelial lineage markers. These cells can be isolated from peripheral, umbilical cord, and bone marrow blood. CD 34 represents a marker of immature stem cells that is commonly used to characterize CEPC together with other surface antigens. Though, as CD 34 is also expressed at lower levels on mature endothelial cells, most recent studies used CD 133, a marker of more immature hematopoietic stem cells that is now considered the best surface marker to define, identify and isolate the CEPC1. CD 133 (also known as AC 133 or prominin) is highly conserved antigen with unknown biological activity. It would be expressed on hematopoietic stem cells, but not on mature endothelial cell and monocytes. In order to reflect the endothelial cells, there is general agreement for the use of at least one additional marker, such as vascular endothelial growth factor receptor-2 (VEGFR-2 or KDR), while others are platelet-endothelial cells adhesion molecules-1 (PECAM-1), von Willebrand factor, c-kit, Tie-2, vascular endothelial-cadherin and VEGFR-12.