In vivo generation of DNA sequence diversity for cellular barcoding

Heterogeneity is a ubiquitous feature of biological systems. A complete understanding of such systems requires a method for uniquely identifying and tracking individual components and their interactions with each other. We have developed a novel method of uniquely tagging individual cells in vivo with a genetic 'barcode' that can be recovered by DNA sequencing. Our method is a two-component system comprised of a genetic barcode cassette whose fragments are shuffled by Rci, a site-specific DNA invertase. The system is highly scalable, with the potential to generate theoretical diversities in the billions. We demonstrate the feasibility of this technique in Escherichia coli. Currently, this method could be employed to track the dynamics of populations of microbes through various bottlenecks. Advances of this method should prove useful in tracking interactions of cells within a network, and/or heterogeneity within complex biological samples

Crosstalk between G-protein and Ca2+ pathways switches intracellular cAMP levels

Cyclic adenosine monophosphate and cyclic guanosine monophosphate are universal intracellular messengers whose concentrations are regulated by molecular networks comprised of different isoforms of the synthases adenylate cyclase or guanylate cyclase and the phosphodiesterases which degrade these compounds. In this paper, we employ a systems biology approach to develop mathematical models of these networks that, for the first time, take into account the different biochemical properties of the isoforms involved. To investigate the mechanisms underlying the joint regulation of cAMP and cGMP, we apply our models to analyse the regulation of cilia beat frequency in Paramecium by Ca2+. Based on our analysis of these models, we propose that the diversity of isoform combinations that occurs in living cells provides an explanation for the huge variety of intracellular processes that are dependent on these networks. The inclusion of both G-protein receptor and Ca 2+-dependent regulation of AC in our models allows us to propose a new explanation for the switching properties of G-protein subunits involved in nucleotide regulation. Analysis of the models suggests that, depending on whether the G-protein subunit is bound to AC, Ca2+ can either activate or inhibit AC in a concentration-dependent manner. The resulting analysis provides an explanation for previous experimental results that showed that alterations in Ca2+ concentrations can either increase or decrease cilia beat frequency over particular Ca2+ concentration ranges. © The Royal Society of Chemistry

Трансплантация сердца и коронавирусная инфекция (COVID-19) в раннем послеоперационном периоде у пациента с гипертрофической обструктивной кардиомиопатией: клинический случай

Hypertrophic cardiomyopathy (HCM) is a disease that is usually unresponsive to conservative pathogenetic therapy. It does not have clearly developed surgical correction algorithms. Heart transplantation (HTx) is the sole therapeutic option when drug therapy is ineffective and surgical reduction of hypertrophic myocardium is not feasible. There are only sporadic reports in the literature about HTx for HCM. The novel coronavirus disease 2019 (COVID-19) pandemic has significantly affected the work of cardiac surgical units and, in particular, organ transplantation activities. This paper presents a clinical case of an HCM patient who underwent HTx, complicated by COVID-19 infection in the early postoperative period.Гипертрофическая кардиомиопатия – это заболевание, в большинстве случаев трудно поддающееся консервативной патогенетической терапии и не обладающее четко разработанными алгоритмами хирургической коррекции. Конечным вариантом лечения при неэффективности медикаментозной терапии и невозможности проведения хирургической редукции гипертрофированного миокарда является трансплантация сердца, о которой в литературе имеются лишь единичные сообщения. Пандемия новой коронавирусной инфекции существенно повлияла на работу кардиохирургических подразделений и в особенности на работу по пересадке органов. В данной статье представлен клинический случай пациента с гипертрофической кардиомиопатией, которому произведена трансплантация сердца, осложнившаяся инфекцией COVID-19 в раннем послеоперационном периоде

Crosstalk between G-protein and Ca2+ pathways switches intracellular cAMP levels

Cyclic adenosine monophosphate and cyclic guanosine monophosphate are universal intracellular messengers whose concentrations are regulated by molecular networks comprised of different isoforms of the synthases adenylate cyclase or guanylate cyclase and the phosphodiesterases which degrade these compounds. In this paper, we employ a systems biology approach to develop mathematical models of these networks that, for the first time, take into account the different biochemical properties of the isoforms involved. To investigate the mechanisms underlying the joint regulation of cAMP and cGMP, we apply our models to analyse the regulation of cilia beat frequency in Paramecium by Ca2+. Based on our analysis of these models, we propose that the diversity of isoform combinations that occurs in living cells provides an explanation for the huge variety of intracellular processes that are dependent on these networks. The inclusion of both G-protein receptor and Ca 2+-dependent regulation of AC in our models allows us to propose a new explanation for the switching properties of G-protein subunits involved in nucleotide regulation. Analysis of the models suggests that, depending on whether the G-protein subunit is bound to AC, Ca2+ can either activate or inhibit AC in a concentration-dependent manner. The resulting analysis provides an explanation for previous experimental results that showed that alterations in Ca2+ concentrations can either increase or decrease cilia beat frequency over particular Ca2+ concentration ranges. © The Royal Society of Chemistry

Crosstalk between G-protein and Ca2+ pathways switches intracellular cAMP levels

Cyclic adenosine monophosphate and cyclic guanosine monophosphate are universal intracellular messengers whose concentrations are regulated by molecular networks comprised of different isoforms of the synthases adenylate cyclase or guanylate cyclase and the phosphodiesterases which degrade these compounds. In this paper, we employ a systems biology approach to develop mathematical models of these networks that, for the first time, take into account the different biochemical properties of the isoforms involved. To investigate the mechanisms underlying the joint regulation of cAMP and cGMP, we apply our models to analyse the regulation of cilia beat frequency in Paramecium by Ca2+. Based on our analysis of these models, we propose that the diversity of isoform combinations that occurs in living cells provides an explanation for the huge variety of intracellular processes that are dependent on these networks. The inclusion of both G-protein receptor and Ca 2+-dependent regulation of AC in our models allows us to propose a new explanation for the switching properties of G-protein subunits involved in nucleotide regulation. Analysis of the models suggests that, depending on whether the G-protein subunit is bound to AC, Ca2+ can either activate or inhibit AC in a concentration-dependent manner. The resulting analysis provides an explanation for previous experimental results that showed that alterations in Ca2+ concentrations can either increase or decrease cilia beat frequency over particular Ca2+ concentration ranges. © The Royal Society of Chemistry

Crosstalk between G-protein and Ca2+ pathways switches intracellular cAMP levels

Cyclic adenosine monophosphate and cyclic guanosine monophosphate are universal intracellular messengers whose concentrations are regulated by molecular networks comprised of different isoforms of the synthases adenylate cyclase or guanylate cyclase and the phosphodiesterases which degrade these compounds. In this paper, we employ a systems biology approach to develop mathematical models of these networks that, for the first time, take into account the different biochemical properties of the isoforms involved. To investigate the mechanisms underlying the joint regulation of cAMP and cGMP, we apply our models to analyse the regulation of cilia beat frequency in Paramecium by Ca2+. Based on our analysis of these models, we propose that the diversity of isoform combinations that occurs in living cells provides an explanation for the huge variety of intracellular processes that are dependent on these networks. The inclusion of both G-protein receptor and Ca 2+-dependent regulation of AC in our models allows us to propose a new explanation for the switching properties of G-protein subunits involved in nucleotide regulation. Analysis of the models suggests that, depending on whether the G-protein subunit is bound to AC, Ca2+ can either activate or inhibit AC in a concentration-dependent manner. The resulting analysis provides an explanation for previous experimental results that showed that alterations in Ca2+ concentrations can either increase or decrease cilia beat frequency over particular Ca2+ concentration ranges. © The Royal Society of Chemistry

AgrobacteriumT-DNA-encoded protein Atu6002 interferes with the host auxin response

Several genes in the Agrobacterium tumefaciens transferred (T)-DNA encode proteins that are involved in developmental alterations, leading to the formation of tumours in infected plants. We investigated the role of the protein encoded by the Atu6002 gene, the function of which is completely unknown. Atu6002 expression occurs in Agrobacterium-induced tumours, and is also activated on activation of plant cell division by growth hormones. Within the expressing plant cells, the Atu6002 protein is targeted to the plasma membrane. Interestingly, constitutive ectopic expression of Atu6002 in transgenic tobacco plants leads to a severe developmental phenotype characterized by stunted growth, shorter internodes, lanceolate leaves, increased branching and modified flower morphology. These Atu6002-expressing plants also display impaired response to auxin. However, auxin cellular uptake and polar transport are not significantly inhibited in these plants, suggesting that Atu6002 interferes with auxin perception or signalling pathways. © 2013 BSPP AND JOHN WILEY & SONS LTD

Computational modelling elucidates the mechanism of ciliary regulation in health and disease

Background: Ciliary dysfunction leads to a number of human pathologies, including primary ciliary dyskinesia, nephronophthisis, situs inversus pathology or infertility. The mechanism of cilia beating regulation is complex and despite extensive experimental characterization remains poorly understood. We develop a detailed systems model for calcium, membrane potential and cyclic nucleotide-dependent ciliary motility regulation.Results: The model describes the intimate relationship between calcium and potassium ionic concentrations inside and outside of cilia with membrane voltage and, for the first time, describes a novel type of ciliary excitability which plays the major role in ciliary movement regulation. Our model describes a mechanism that allows ciliary excitation to be robust over a wide physiological range of extracellular ionic concentrations. The model predicts the existence of several dynamic modes of ciliary regulation, such as the generation of intraciliary Ca2+ spike with amplitude proportional to the degree of membrane depolarization, the ability to maintain stable oscillations, monostable multivibrator regimes, all of which are initiated by variability in ionic concentrations that translate into altered membrane voltage.Conclusions: Computational investigation of the model offers several new insights into the underlying molecular mechanisms of ciliary pathologies. According to our analysis, the reported dynamic regulatory modes can be a physiological reaction to alterations in the extracellular environment. However, modification of the dynamic modes, as a result of genetic mutations or environmental conditions, can cause a life threatening pathology. © 2011 Kotov et al; licensee BioMed Central Ltd

Computational modelling elucidates the mechanism of ciliary regulation in health and disease

Background: Ciliary dysfunction leads to a number of human pathologies, including primary ciliary dyskinesia, nephronophthisis, situs inversus pathology or infertility. The mechanism of cilia beating regulation is complex and despite extensive experimental characterization remains poorly understood. We develop a detailed systems model for calcium, membrane potential and cyclic nucleotide-dependent ciliary motility regulation.Results: The model describes the intimate relationship between calcium and potassium ionic concentrations inside and outside of cilia with membrane voltage and, for the first time, describes a novel type of ciliary excitability which plays the major role in ciliary movement regulation. Our model describes a mechanism that allows ciliary excitation to be robust over a wide physiological range of extracellular ionic concentrations. The model predicts the existence of several dynamic modes of ciliary regulation, such as the generation of intraciliary Ca2+ spike with amplitude proportional to the degree of membrane depolarization, the ability to maintain stable oscillations, monostable multivibrator regimes, all of which are initiated by variability in ionic concentrations that translate into altered membrane voltage.Conclusions: Computational investigation of the model offers several new insights into the underlying molecular mechanisms of ciliary pathologies. According to our analysis, the reported dynamic regulatory modes can be a physiological reaction to alterations in the extracellular environment. However, modification of the dynamic modes, as a result of genetic mutations or environmental conditions, can cause a life threatening pathology. © 2011 Kotov et al; licensee BioMed Central Ltd

Database of patients with sarcoidosis of the Republic of Tatarstan: a retrospective analysis for 50 years

Background: Sarcoidosis is a granulomatous disease with no established etiology. The prevalence of sarcoidosis is growing, there are changes in the clinic of the disease depending on geolocation and the environment.Aim: To analyze the database (register) of sarcoidosis patients registered with this disease in the Republic of Tatarstan.Materials and methods: In Tatarstan, an electronic database of 2715 patients with sarcoidosis has been created, collected over the past 50 years. The frequencies of the phenomena were estimated, and the ChI-square Pearson criterion was calculated to assess the relationship of events and their reliability.Results: There were 69.2% of women and 30.8% of men. The average age was 44.2 years (15 to 87 years, median 44 years). Men were younger (median 36 years old) than women (median 48 years old). Most often, there was stage II (47.8%) and stage I (40.8%). Lofgren's syndrome was in 13% of patients. 42% had biopsy data, over three decades its frequency increased -21.9%, 34.8% and 49.0%, respectively. After 2010, there was an increase in stage II sarcoidosis, over the past 20 years, the proportion of women has decreased and the proportion of men has grown. Adverse factors of the profession orthe environment were in every third patient. The frequency of prescribing prednisone decreased from 2013 to 2019 from 23.1% to 9.1%, and pentoxifylline increased from 14.9% in 2011 to 58% in 2019. Every third patient received vitamin E.Conclusion: About 100 new patients were identified annually. An increase in the II radiation stage of sarcoidosis was noted. A biopsy was performed only on every second patient. The treatment was consistent with the international approach - to use prednisone and cytostatics only with the progression of the process