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1.
Biomedicines ; 12(4)2024 Apr 02.
Article in English | MEDLINE | ID: mdl-38672138

ABSTRACT

Osteoarthritis is a chronic progressive joint disease that clinically debuts at the stage of pronounced morphologic changes, which makes treatment difficult. In this regard, an important task is the study of genetic markers of the disease, which have not been definitively established, due to the clinical and ethnic heterogeneity of the studied populations. To find the genetic markers for the development of knee osteoarthritis (OA) in women from the Volga-Ural region of Russia, we conducted research in two stages using different genotyping methods, such as the restriction fragment length polymorphism (RFLP) measurement, TaqMan technology and competitive allele-specific PCR-KASPTM. In the first stage, we studied polymorphic variants of candidate genes (ACAN, ADAMTS5, CHST11, SOX9, COL1A1) for OA development. The association of the *27 allele of the VNTR locus of the ACAN gene was identified (OR = 1.6). In the second stage, we replicated the GWAS results (ASTN2, ALDH1A2, DVWA, CHST11, GNL3, NCOA3, FILIP/SENP1, MCF2L, GLT8D, DOT1L) for knee OA studies. The association of the *T allele of the rs7639618 locus of the DVWA gene was detected (OR = 1.54). Thus, the VNTR locus of ACAN and the rs7639618 locus of DVWA are risk factors for knee OA in women from the Volga-Ural region of Russia.

2.
J Nat Prod ; 87(4): 664-674, 2024 Apr 26.
Article in English | MEDLINE | ID: mdl-38362867

ABSTRACT

We report the molecular mechanism of action of gausemycins and the isolation of new members of the family, gausemycins C (1c), D (1d), E (1e), and F (1f), the minor components of the mixture. To elucidate the mechanism of action of gausemycins, we investigated the antimicrobial activity of the most active compounds, gausemycins A and B, in the presence of Ca2+, other metal ions, and phosphate. Gausemycins require a significantly higher Ca2+ concentration for maximum activity than daptomycin but lower than that required for malacidine and cadasides. Species-specific antimicrobial activity was found upon testing against a wide panel of Gram-positive bacteria. Membranoactivity of gausemycins was demonstrated upon their interactions with model lipid bilayers and micelles. The pore-forming ability was found to be dramatically dependent on the Ca2+ concentration and the membrane lipid composition. An NMR study of gausemycin B in zwitterionic and anionic micelles suggested the putative structure of the gausemycin/membrane complex and revealed the binding of Ca2+ by the macrocyclic domain of the antibiotic.


Subject(s)
Anti-Bacterial Agents , Calcium , Gram-Positive Bacteria , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Calcium/metabolism , Molecular Structure , Gram-Positive Bacteria/drug effects , Cell Membrane/drug effects , Daptomycin/pharmacology , Daptomycin/chemistry , Lipid Bilayers/chemistry , Micelles
3.
Int J Mol Sci ; 24(21)2023 Oct 28.
Article in English | MEDLINE | ID: mdl-37958692

ABSTRACT

Traumatic brain injury (TBI) is one of the leading causes of disability and death worldwide. It is characterized by various molecular-cellular events, with the main ones being apoptosis and damage to axons. To date, there are no clinically effective neuroprotective drugs. In this study, we examined the role of hydrogen sulfide (H2S) in the localization and expression of the key pro-apoptotic protein p53, as well as cell death in the nervous tissue in TBI and axotomy. We used a fast donor (sodium sulphide, Na2S) H2S and a classic inhibitor (aminooxyacetic acid, AOAA) of cystathionine ß-synthase (CBS), which is a key enzyme in H2S synthesis. These studies were carried out on three models of neurotrauma in vertebrates and invertebrates. As a result, it was found that Na2S exhibits a pronounced neuroprotective effect that reduces the number of TUNEL-positive neurons and glial cells in TBI and apoptotic glia in axotomy. This effect could be realized through the Na2S-dependent decrease in the level of p53 in the cells of the nervous tissue of vertebrates and invertebrates, which we observed in our study. We also observed the opposite effect when using AOAA, which indicates the important role of CBS in the regulation of p53 expression and death of neurons and glial cells in TBI and axotomy.


Subject(s)
Brain Injuries, Traumatic , Hydrogen Sulfide , Nerve Tissue , Neuroprotective Agents , Animals , Hydrogen Sulfide/pharmacology , Hydrogen Sulfide/metabolism , Tumor Suppressor Protein p53/metabolism , Axotomy , Apoptosis , Nerve Tissue/metabolism , Neuroprotective Agents/pharmacology , Cystathionine beta-Synthase/metabolism
4.
Biomedicines ; 11(11)2023 Nov 06.
Article in English | MEDLINE | ID: mdl-38001982

ABSTRACT

Peak bone mass is the amount of bone tissue that is formed when a stable skeletal state is achieved at a young age. To date, there are no established peak bone mass standards nor clear data on the age at which peak bone mass occurs. At the same time, the level of peak bone mass at a young age is an important predictor of the onset of primary osteoporosis. The purpose of this review is to analyze the results of studies of levels of peak bone mass in general, the age of its onset, as well as factors influencing its formation. Factors such as hormonal levels, body composition, physical activity, nutrition, heredity, smoking, lifestyle, prenatal predictors, intestinal microbiota, and vitamin and micronutrient status were considered, and a comprehensive scheme of the influence of these factors on the level of peak bone mass was created. Determining the standards and timing of the formation of peak bone mass, and the factors affecting it, will help in the development of measures to prevent its shortage and the consequent prevention of osteoporosis and concomitant diseases.

5.
Antibiotics (Basel) ; 12(8)2023 Aug 19.
Article in English | MEDLINE | ID: mdl-37627760

ABSTRACT

Sensing of antibiotic-bacteria interactions is an important area of research that has gained significant attention in recent years. Antibiotic resistance is a major public health concern, and it is essential to develop new strategies for detecting and monitoring bacterial responses to antibiotics in order to maintain effective antibiotic development and antibacterial treatment. This review summarizes recent advances in sensing strategies for antibiotic-bacteria interactions, which are divided into two main parts: studies on the mechanism of action for sensitive bacteria and interrogation of the defense mechanisms for resistant ones. In conclusion, this review provides an overview of the present research landscape concerning antibiotic-bacteria interactions, emphasizing the potential for method adaptation and the integration of machine learning techniques in data analysis, which could potentially lead to a transformative impact on mechanistic studies within the field.

6.
Life (Basel) ; 13(5)2023 Apr 23.
Article in English | MEDLINE | ID: mdl-37240718

ABSTRACT

Natural scaffolds remain an important basis for drug development. Therefore, approaches to natural bioactive compound discovery attract significant attention. In this account, we summarize modern and emerging trends in the screening and identification of natural antibiotics. The methods are divided into three large groups: approaches based on microbiology, chemistry, and molecular biology. The scientific potential of the methods is illustrated with the most prominent and recent results.

7.
Int J Mol Sci ; 24(9)2023 Apr 28.
Article in English | MEDLINE | ID: mdl-37175737

ABSTRACT

Calvarial doughnut lesions (CDL) with bone fragility with or without spondylometaphyseal dysplasia (MIM: #126550) is a rare autosomal dominant skeletal disorder characterized by low bone mineral density, spinal and peripheral fractures, and specific sclerotic lesions of the cranial bones. In the current classification of skeletal disorders, the disease is included in the group of bone fragility disorders along with osteogenesis imperfecta. The disease is caused by pathogenic variants in the SGMS2 gene, the protein product of which is sphingomyelin synthase 2, which primarily contributes to sphingomyelin (SM) synthesis-the main lipid component of the plasma membrane essential for bone mineralization. To date, 15 patients from eight families with CDL with bone fragility have been described in the literature, and a recurrent variant c.148C>T (p.Arg50Ter) in the SGMS2 gene has been identified, which was found in patients from six families. We diagnosed the disease in 11 more patients from three unrelated families, caused by the same heterozygous nonsense variant c.148C>T (p.Arg50Ter) in the SGMS2 gene. Our results show wide interfamilial and intrafamilial phenotypic variability in patients with a detected recurrent variant in the SGMS2 gene, the presence of which must be taken into consideration in the diagnosis of the disease. The primary analysis of this variant will contribute to optimal molecular genetic diagnostics, which can reduce diagnostic costs and time.


Subject(s)
Fractures, Bone , Osteochondrodysplasias , Osteogenesis Imperfecta , Humans , Calcification, Physiologic , Fractures, Bone/genetics , Heterozygote , Osteogenesis Imperfecta/genetics
8.
Int J Mol Sci ; 24(7)2023 Mar 23.
Article in English | MEDLINE | ID: mdl-37046987

ABSTRACT

Cardiovascular, rheumatic, kidney, and neurodegenerative diseases and mental disorders are a common cause of deterioration in the quality of life up to severe disability and death worldwide. Many pathological conditions, including this group of diseases, are based on increased cell death through apoptosis. It is known that this process is associated with signaling pathways controlled by a group of gaseous signaling molecules called gasotransmitters. They are unique messengers that can control the process of apoptosis at different stages of its implementation. However, their role in the regulation of apoptotic signaling in these pathological conditions is often controversial and not completely clear. This review analyzes the role of nitric oxide (NO), carbon monoxide (CO), hydrogen sulfide (H2S), and sulfur dioxide (SO2) in apoptotic cell death in cardiovascular, rheumatic, kidney, and neurodegenerative diseases. The signaling processes involved in apoptosis in schizophrenia, bipolar, depressive, and anxiety disorders are also considered. The role of gasotransmitters in apoptosis in these diseases is largely determined by cell specificity and concentration. NO has the greatest dualism; scales are more prone to apoptosis. At the same time, CO, H2S, and SO2 are more involved in cytoprotective processes.


Subject(s)
Gasotransmitters , Hydrogen Sulfide , Mental Disorders , Neurodegenerative Diseases , Humans , Gasotransmitters/metabolism , Quality of Life , Hydrogen Sulfide/metabolism , Nitric Oxide/metabolism , Carbon Monoxide/metabolism , Kidney/metabolism , Apoptosis
9.
Biology (Basel) ; 11(11)2022 Nov 18.
Article in English | MEDLINE | ID: mdl-36421390

ABSTRACT

Actinobacteria are involved into multilateral relationships between insects, their food sources, infectious agents, etc. Antibiotics and related natural products play an essential role in such systems. The literature from the January 2016-August 2022 period devoted to insect-associated actinomycetes with antagonistic and/or enzyme-inhibiting activity was selected. Recent progress in multidisciplinary studies of insect-actinobacterial interactions mediated by antibiotics is summarized and discussed.

10.
Biomedicines ; 10(10)2022 Sep 22.
Article in English | MEDLINE | ID: mdl-36289625

ABSTRACT

Osteogenesis imperfecta (OI) is a large group of genetically heterogeneous diseases resulting from decreased bone density and an abnormal microarchitecture, which are clinically manifested by abnormal bone fractures. A distinctive clinical feature of this group of diseases is the presence of spontaneous fractures and skeletal deformities. However, the clinical manifestations of different types of OI are characterized by marked polymorphism with variable severity of skeletal and extra-skeletal features. Previous studies have shown that a mutation (c.-14C>T) in the IFITM5 gene is responsible for autosomal dominant OI type V. However, the mutation has a variable expression pattern and marked clinical heterogeneity. In this study, a clinical and genetic analysis of 12 cases with molecularly confirmed OI type V from 12 unrelated families was performed. Significant clinical heterogeneity of the disease with the same molecular defect was detected. In six subjects (50%), there were no classic signs of OI type V (formation of a hyperplastic bone callus, calcification of the interosseous membrane and dislocation of the radial head). In all cases, the mutation occurred de novo.

11.
Int J Mol Sci ; 23(17)2022 Sep 02.
Article in English | MEDLINE | ID: mdl-36077420

ABSTRACT

Osteoporosis (OP) is a multifactorial bone disease belonging to the metabolic osteopathies group. Using the polygenic score (PGS) approach, we combined the effects of bone mineral density (BMD) DNA loci, affecting osteoporosis pathogenesis, based on GEFOS/GENOMOS consortium GWAS meta-analysis. We developed models to predict the risk of low fractures in women from the Volga-Ural region of Russia with efficacy of 74% (AUC = 0.740; OR (95% CI) = 2.9 (2.353-3.536)), as well as the formation of low BMD with efficacy of 79% (AUC = 0.790; OR (95% CI) = 3.94 (2.993-5.337)). In addition, we propose a model that predicts fracture risk and low BMD in a comorbid condition with 85% accuracy (AUC = 0.850; OR (95% CI) = 6.6 (4.411-10.608)) in postmenopausal women.


Subject(s)
Bone Diseases, Metabolic , Fractures, Bone , Osteoporosis, Postmenopausal , Osteoporosis , Bone Density/genetics , Female , Fractures, Bone/etiology , Humans , Multifactorial Inheritance , Osteoporosis/complications , Osteoporosis/genetics , Osteoporosis, Postmenopausal/genetics
12.
Front Cardiovasc Med ; 9: 916156, 2022.
Article in English | MEDLINE | ID: mdl-35966512

ABSTRACT

Introduction: Cardiovascular events are common in COVID-19. While the use of anticoagulation during hospitalization has been established in current guidelines, recommendations regarding antithrombotic therapy in the post-discharge period are conflicting. Methods: To investigate this issue, we conducted a retrospective follow-up (393 ± 87 days) of 1,746 consecutive patients, hospitalized with and surviving COVID-19 pneumonia at a single tertiary medical center between April and December 2020. Survivors received either 30-day post-discharge antithrombotic treatment regime using prophylactic direct oral anticoagulation (DOAC; n = 1,002) or dipyridamole (n = 304), or, no post-discharge antithrombotic treatment (Ctrl; n = 440). All-cause mortality, as well as cardiovascular mortality (CVM) and further cardiovascular outcomes (CVO) resulting in hospitalization due to pulmonary embolism (PE), myocardial infarction (MI) and stroke were investigated during the follow-up period. Results: While no major bleeding events occured during follow-up in the treatment groups, Ctrl showed a high but evenly distributed rate all-cause mortality. All-cause mortality (CVM) was attenuated by prophylactic DOAC (0.6%, P < 0.001) and dipyridamole (0.7%, P < 0.001). This effect was also evident for both therapies after propensity score analyses using weighted binary logistic regression [DOAC: B = -3.33 (0.60), P < 0.001 and dipyridamole: B = -3.04 (0.76), P < 0.001]. While both treatment groups displayed a reduced rate of CVM [DOAC: B = -2.69 (0.74), P < 0.001 and dipyridamole: B = -17.95 (0.37), P < 0.001], the effect in the DOAC group was driven by reduction of both PE [B-3.12 (1.42), P = 0.012] and stroke [B = -3.08 (1.23), P = 0.028]. Dipyridamole significantly reduced rates of PE alone [B = -17.05 (1.01), P < 0.001]. Conclusion: Late cardiovascular events and all-cause mortality were high in the year following hospitalization for COVID-19. Application of prophylactic DOAC or dipyridamole in the early post-discharge period improved mid- and long-term CVO and all-cause mortality in COVID-19 survivors.

13.
Front Immunol ; 13: 856883, 2022.
Article in English | MEDLINE | ID: mdl-35603207

ABSTRACT

The immune system is severely compromised in patients with COVID-19. The representative group of 43 patients were selected from the cohort of 342 patients with COVID-19 and pneumonia. This group of 43 patients was examined for the levels of C-reactive protein, biomarker of systemic inflammation, and for the subsets of adaptive immune cells. The immunological parameters were correlated with the metabolic parameters and cardiovascular pathology history. We identified that a decrease in the absolute number of T-lymphocytes, T-cytotoxic, T-activated and B-lymphocytes correlated with the higher levels of CRP. The absolute number of T-helpers and the absolute number of double positive T-lymphocytes positively correlated with the levels of iron in serum (Z= 0,310 and Z=0,394). The absolute numbers of T-activated lymphocytes positively correlated with serum levels of LDH (Z = 0,422), ferritin (Z = 0,407) and iron (Z = 0,418). When studying subpopulations of lymphocytes, depending on the combined pathology, we found that the absolute numbers of B-lymphocytes and double positive T-lymphocytes in the peripheral blood were significantly reduced in patients with arterial hypertension (p=0,0074 and p=0,0227, correspondingly). The increased levels of NK cell were found in patients with a history of coronary heart disease (p=0,0108). In addition, we found that deficiencies in the adaptive immune system correlated with the deficiencies in iron metabolism. The cardiovascular pathology upsets the balance in the adaptive and innate immune system in the circulation of patient with severe COVID-19.


Subject(s)
COVID-19 , C-Reactive Protein , Humans , Iron , Killer Cells, Natural , Lymphocyte Subsets
14.
Genes (Basel) ; 13(1)2022 01 10.
Article in English | MEDLINE | ID: mdl-35052464

ABSTRACT

Osteogenesis imperfecta (OI) is an inherited disease of bone characterized by increased bone fragility. Here, we report the results of the molecular architecture of osteogenesis imperfecta research in patients from Bashkortostan Republic, Russia. In total, 16 mutations in COL1A1, 11 mutations in COL1A2, and 1 mutation in P3H1 and IFIMT5 genes were found in isolated states; 11 of them were not previously reported in literature. We found mutations in CLCN7, ALOX12B, PLEKHM1, ERCC4, ARSB, PTH1R, and TGFB1 that were not associated with OI pathogenesis in patients with increased bone fragility. Additionally, we found combined mutations (c.2869C>T, p. Gln957* in COL1A1 and c.1197+5G>A in COL1A2; c.579delT, p. Gly194fs in COL1A1 and c.1197+5G>A in COL1A2; c.2971G>C, p. Gly991Arg in COL1A2 and c.212G>C, p.Ser71Thr in FGF23; c.-14C>T in IFITM5 and c.1903C>T, p. Arg635* in LAMB3) in 4 patients with typical OI clinic phenotypes.


Subject(s)
Collagen Type I/genetics , Membrane Glycoproteins/genetics , Membrane Proteins/genetics , Mutation , Osteogenesis Imperfecta/pathology , Prolyl Hydroxylases/genetics , Proteoglycans/genetics , Adolescent , Adult , Child , Child, Preschool , Female , Genetic Association Studies , Humans , Male , Middle Aged , Osteogenesis Imperfecta/epidemiology , Osteogenesis Imperfecta/genetics , Phenotype , Russia , Young Adult
15.
PLoS One ; 16(10): e0257982, 2021.
Article in English | MEDLINE | ID: mdl-34648510

ABSTRACT

BACKGROUND: J-waves represent a common finding in routine ECGs (5-6%) and are closely linked to ventricular tachycardias. While arrhythmias and non-specific ECG alterations are a frequent finding in COVID-19, an analysis of J-wave incidence in acute COVID-19 is lacking. METHODS: A total of 386 patients consecutively, hospitalized due to acute COVID-19 pneumonia were included in this retrospective analysis. Admission ECGs were analyzed, screened for J-waves and correlated to clinical characteristics and 28-day mortality. RESULTS: J-waves were present in 12.2% of patients. Factors associated with the presence of J-waves were old age, female sex, a history of stroke and/or heart failure, high CRP levels as well as a high BMI. Mortality rates were significantly higher in patients with J-waves in the admission ECG compared to the non-J-wave cohort (J-wave: 14.9% vs. non-J-wave 3.8%, p = 0.001). After adjusting for confounders using a multivariable cox regression model, the incidence of J-waves was an independent predictor of mortality at 28-days (OR 2.76 95% CI: 1.15-6.63; p = 0.023). J-waves disappeared or declined in 36.4% of COVID-19 survivors with available ECGs for 6-8 months follow-up. CONCLUSION: J-waves are frequently and often transiently found in the admission ECG of patients hospitalized with acute COVID-19. Furthermore, they seem to be an independent predictor of 28-day mortality.


Subject(s)
Arrhythmias, Cardiac/physiopathology , COVID-19/physiopathology , Tachycardia, Ventricular/physiopathology , Aged , Arrhythmias, Cardiac/mortality , COVID-19/mortality , Electrocardiography , Female , Humans , Male , Middle Aged , Prognosis , Retrospective Studies , Tachycardia, Ventricular/mortality
16.
Diagnostics (Basel) ; 11(7)2021 Jul 06.
Article in English | MEDLINE | ID: mdl-34359306

ABSTRACT

Over the past decades, numerous studies on the genetic markers of osteoarthritis (OA) have been conducted. MiRNA targets sites are a promising new area of research. In this study, we analyzed the polymorphic variants in 3' UTR regions of COL1A1, COL11A1, ADAMTS5, MMP1, MMP13, SOX9, GDF5, FGF2, FGFR1, and FGFRL1 genes to examine the association between miRNA target site alteration and the incidence of OA in women from the Volga-Ural region of Russia using competitive allele-specific PCR. The T allele of the rs9659030 was associated with generalized OA (OR = 2.0), whereas the C allele of the rs229069 was associated with total OA (OR = 1.43). The T allele of the rs13317 was associated with the total OA (OR = 1.67). After Benjamini-Hochberg correction, only rs13317 remained statistically significant. According to ethnic heterogeneity, associations between the T allele (rs1061237) with OA in women of Russian descent (OR = 1.77), the G allele (rs6854081) in women of Tatar descent (OR = 4.78), the C allele (rs229069) and the T allele (rs73611720) in women of mixed descent and other ethnic groups (OR = 2.25 and OR = 3.02, respectively) were identified. All associations remained statistically significant after Benjamini-Hochberg correction. Together, this study identified miRNA target sites as a genetic marker for the development of OA in various ethnic groups.

17.
Molecules ; 26(13)2021 Jun 29.
Article in English | MEDLINE | ID: mdl-34209713

ABSTRACT

Antiviral action of various photosensitizers is already summarized in several comprehensive reviews, and various mechanisms have been proposed for it. However, a critical consideration of the matter of the area is complicated, since the exact mechanisms are very difficult to explore and clarify, and most publications are of an empirical and "phenomenological" nature, reporting a dependence of the antiviral action on illumination, or a correlation of activity with the photophysical properties of the substances. Of particular interest is substance-assisted photogeneration of highly reactive singlet oxygen (1O2). The damaging action of 1O2 on the lipids of the viral envelope can probably lead to a loss of the ability of the lipid bilayer of enveloped viruses to fuse with the lipid membrane of the host cell. Thus, lipid bilayer-affine 1O2 photosensitizers have prospects as broad-spectrum antivirals against enveloped viruses. In this short review, we want to point out the main types of antiviral photosensitizers with potential affinity to the lipid bilayer and summarize the data on new compounds over the past three years. Further understanding of the data in the field will spur a targeted search for substances with antiviral activity against enveloped viruses among photosensitizers able to bind to the lipid membranes.


Subject(s)
Antiviral Agents , Membrane Lipids/metabolism , Photosensitizing Agents , Viral Envelope/metabolism , Virus Diseases , Viruses/metabolism , Animals , Antiviral Agents/chemistry , Antiviral Agents/pharmacokinetics , Antiviral Agents/therapeutic use , Humans , Photosensitizing Agents/chemistry , Photosensitizing Agents/pharmacokinetics , Photosensitizing Agents/therapeutic use , Singlet Oxygen , Virus Diseases/drug therapy , Virus Diseases/metabolism
18.
Angew Chem Int Ed Engl ; 60(34): 18694-18703, 2021 08 16.
Article in English | MEDLINE | ID: mdl-34009717

ABSTRACT

We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated. The compounds are cyclic peptides with a unique peptide core and several remarkable structural features, including unusual positions of d-amino acids, lack of the Ca2+ -binding Asp-X-Asp-Gly (DXDG) motif, tyrosine glycosylation with arabinose, presence of 2-amino-4-hydroxy-4-phenylbutyric acid (Ahpb) and chlorinated kynurenine (ClKyn), and N-acylation of the ornithine side chain. Gausemycins have pronounced activity against Gram-positive bacteria. Mechanistic studies highlight significant differences compared to known glyco- and lipopeptides. Gausemycins exhibit only slight Ca2+ -dependence of activity and induce no pore formation at low concentrations. Moreover, there is no detectable accumulation of cell wall biosynthesis precursors under treatment with gausemycins.


Subject(s)
Lipoglycopeptides/isolation & purification , Streptomyces/chemistry , Lipoglycopeptides/chemistry , Molecular Conformation
19.
Talanta ; 225: 121930, 2021 Apr 01.
Article in English | MEDLINE | ID: mdl-33592699

ABSTRACT

Nonribosomal cyclopeptide cyclosporin A (CsA), produced by fungus Tolypocladium inflatum, is an extremely important immunosuppressive drug used in organ transplantations and for therapy of autoimmune diseases. Here we report for the first time production of CsA, along with related cyclosporins B and C, by Tolypocladium inflatum strains of marine origin (White Sea). Cyclosporins A-C contain an unusual amino acid, (4R)-4-((E)-2-butenyl)-4,N-dimethyl-l-threonine (MeBmt), and are prone to isomerization to non-active isocyclosporin by N→O acyl shift of valine connected to MeBmt in acidic conditions. CsA and isoCsA are not distinguishable in MS analysis of [M+H]+ ions due to rapid [CsA + H]+→[isoCsA + H]+ conversion. We found that the N→O acyl shift is completely suppressed in cyclosporine [M+2H]2+ ions, and their collision-induced dissociation (CID) can be used for rapid and unambiguous analysis of cyclosporins and isocylosporins. Fragmentation patterns of [CsA+2H]2+ and [isoCsA+2H]2+ ions were analyzed and explained. The developed approach could be useful for MS analysis of other peptides containing ß-hydroxy-α-amino acids.


Subject(s)
Immunosuppressive Agents , Peptides , Dissociative Disorders , Humans , Hypocreales , Ions
20.
Microorganisms ; 8(12)2020 Dec 09.
Article in English | MEDLINE | ID: mdl-33316994

ABSTRACT

Antibiotics produced by symbiotic microorganisms were previously shown to be of crucial importance for ecological communities, including ants. Previous works on ant-actinobacteria symbiosis are mainly focused on farming ants, which use antifungal microbial secondary metabolites to control pathogens in their fungal gardens. In this work, we studied microorganisms associated with carpenter ant Camponotus vagus. Pronounced antifungal activity of isolated actinobacteria strain A10 was found to be facilitated by biosynthesis of the antimycin A complex, consisting of small hydrophobic depsipeptides with high antimicrobial and cytotoxic activity. The actinomycete strain A10 was identified as Streptomyces albidoflavus. We studied the antagonistic activity of strain A10 against several entomopathogenic microorganisms. The antifungal activity of this strain potentially indicates a defensive symbiosis with the host ant, producing antimycins to protect carpenter ants against infections. The nature of this ant-microbe association however remains to be established.

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