Human TRPV1 is an efficient thermogenetic actuator for chronic neuromodulation.

Thermogenetics is a promising neuromodulation technique based on the use of heat-sensitive ion channels. However, on the way to its clinical application, a number of questions have to be addressed. First, to avoid immune response in future human applications, human ion channels should be studied as thermogenetic actuators.

Identification of De Novo Dividing Stem Cells.

The ability to alternate between quiescent and proliferating states is a remarkable feature of many types of somatic stem cells. The balance between quiescent and proliferating states is vital for maintenance of stem cells over the lifespan, and its disturbance may lead to premature depletion of the stem cell pool and loss of the tissue regenerative or renewal capacity at later stages of life. The question on how this balance is regulated is of critical importance in stem cell research and biology of aging.

Optogenetic and chemogenetic approaches for modeling neurological disorders in vivo.

Animal models of human neurological disorders provide valuable experimental tools which enable us to study various aspects of disorder pathogeneses, ranging from structural abnormalities and disrupted metabolism and signaling to motor and mental deficits, and allow us to test novel therapies in preclinical studies. To be valid, these animal models should recapitulate complex pathological features at the molecular, cellular, tissue, and behavioral levels as closely as possible to those observed in human subjects. Pathological states resembling known human neurological disorders can be induced in animal species by toxins, genetic factors, lesioning, or exposure to extreme conditions.

Aging Modulates the Ability of Quiescent Radial Glia-Like Stem Cells in the Hippocampal Dentate Gyrus to be Recruited into Division by Pro-neurogenic Stimuli.

A delicate balance between quiescence and division of the radial glia-like stem cells (RGLs) ensures continuation of adult hippocampal neurogenesis (AHN) over the lifespan. Transient or persistent perturbations of this balance due to a brain pathology, drug administration, or therapy can lead to unfavorable long-term outcomes such as premature depletion of the RGLs, decreased AHN, and cognitive deficit. Memantine, a drug used for alleviating the symptoms of Alzheimer's disease, and electroconvulsive seizure (ECS), a procedure used for treating drug-resistant major depression or bipolar disorder, are known strong AHN inducers; they were earlier demonstrated to increase numbers of dividing RGLs.

YTnC2, an improved genetically encoded green calcium indicator based on toadfish troponin C.

Genetically encoded calcium indicators based on truncated troponin C are attractive probes for calcium imaging due to their relatively small molecular size and twofold reduced calcium ion buffering. However, the best-suited members of this family, YTnC and cNTnC, suffer from low molecular brightness, limited dynamic range, and/or poor sensitivity to calcium transients in neurons. To overcome these limitations, we developed an enhanced version of YTnC, named YTnC2.

Nitric Oxide Synthase Blockade Impairs Spontaneous Calcium Activity in Mouse Primary Hippocampal Culture Cells.

Oscillation of intracellular calcium concentration is a stable phenomenon that affects cellular function throughout the lifetime of both electrically excitable and non-excitable cells. Nitric oxide, a gaseous secondary messenger and the product of nitric oxide synthase (NOS), affects intracellular calcium dynamics. Using mouse hippocampal primary cultures, we recorded the effect of NOS blockade on neuronal spontaneous calcium activity.

Chemogenetic emulation of intraneuronal oxidative stress affects synaptic plasticity.

Oxidative stress, a state of disrupted redox signaling, reactive oxygen species (ROS) overproduction, and oxidative cell damage, accompanies numerous brain pathologies, including aging-related dementia and Alzheimer's disease, the most common neurodegenerative disorder of the elderly population. However, a causative role of neuronal oxidative stress in the development of aging-related cognitive decline and neurodegeneration remains elusive because of the lack of approaches for modeling isolated oxidative injury in the brain. Here, we present a chemogenetic approach based on the yeast flavoprotein d-amino acid oxidase (DAAO) for the generation of intraneuronal hydrogen peroxide (HO).

Detection of De Novo Dividing Stem Cells In Situ through Double Nucleotide Analogue Labeling.

Tissue-specific somatic stem cells are characterized by their ability to reside in a state of prolonged reversible cell cycle arrest, referred to as quiescence. Maintenance of a balance between cell quiescence and division is critical for tissue homeostasis at the cellular level and is dynamically regulated by numerous extrinsic and intrinsic factors. Analysis of the activation of quiescent stem cells has been challenging because of a lack of methods for direct detection of de novo dividing cells.

The bioavailability time of commonly used thymidine analogues after intraperitoneal delivery in mice: labeling kinetics in vivo and clearance from blood serum.

Detection of synthetic thymidine analogues after their incorporation into replicating DNA during the S-phase of the cell cycle is a widely exploited methodology for evaluating proliferative activity, tracing dividing and post-mitotic cells, and determining cell-cycle parameters both in vitro and in vivo. To produce valid quantitative readouts for in vivo experiments with single intraperitoneal delivery of a particular nucleotide, it is necessary to determine the time interval during which a synthetic thymidine analogue can be incorporated into newly synthesized DNA, and the time by which the nucleotide is cleared from the blood serum. To date, using a variety of methods, only the bioavailability time of tritiated thymidine and 5-bromo-2'-deoxyuridine (BrdU) have been evaluated.

Recent advances in nucleotide analogue-based techniques for tracking dividing stem cells: An overview.

Detection of thymidine analogues after their incorporation into replicating DNA represents a powerful tool for the study of cellular DNA synthesis, progression through the cell cycle, cell proliferation kinetics, chronology of cell division, and cell fate determination. Recent advances in the concurrent detection of multiple such analogues offer new avenues for the investigation of unknown features of these vital cellular processes. Combined with quantitative analysis, temporal discrimination of multiple labels enables elucidation of various aspects of stem cell life cycle in situ, such as division modes, differentiation, maintenance, and elimination.

A guide to genetically encoded tools for the study of H O.

Cell metabolism heavily relies on the redox reactions that inevitably generate reactive oxygen species (ROS). It is now well established that ROS fluctuations near basal levels coordinate numerous physiological processes in living organisms, thus exhibiting regulatory functions. Hydrogen peroxide, the most long-lived ROS, is a key contributor to ROS-dependent signal transduction in the cell.

Glucocorticoid-mediated mechanisms of hippocampal damage: Contribution of subgranular neurogenesis.

A comprehensive overview of the interplay between glucocorticoids (GCs) and adult hippocampal neurogenesis (AHN) is presented, particularly, in the context of a diseased brain. The effectors of GCs in the dentate gyrus neurogenic niche of the hippocampal are reviewed, and the consequences of the GC signaling on the generation and integration of new neurons are discussed. Recent findings demonstrating how GC signaling mediates impairments of the AHN in various brain pathologies are overviewed.

In Vivo Imaging with Genetically Encoded Redox Biosensors.

Redox reactions are of high fundamental and practical interest since they are involved in both normal physiology and the pathogenesis of various diseases. However, this area of research has always been a relatively problematic field in the context of analytical approaches, mostly because of the unstable nature of the compounds that are measured. Genetically encoded sensors allow for the registration of highly reactive molecules in real-time mode and, therefore, they began a new era in redox biology.

Correction to: Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches.

An amendment to this paper has been published and can be accessed via the original article.

Genetically Encoded Tools for Research of Cell Signaling and Metabolism under Brain Hypoxia.

Hypoxia is characterized by low oxygen content in the tissues. The central nervous system (CNS) is highly vulnerable to a lack of oxygen. Prolonged hypoxia leads to the death of brain cells, which underlies the development of many pathological conditions.

Draft genome sequences of Hirudo medicinalis and salivary transcriptome of three closely related medicinal leeches.

Background: Salivary cell secretion (SCS) plays a critical role in blood feeding by medicinal leeches, making them of use for certain medical purposes even today.

Results: We annotated the Hirudo medicinalis genome and performed RNA-seq on salivary cells isolated from three closely related leech species, H. medicinalis, Hirudo orientalis, and Hirudo verbana.

Novel Genetically Encoded Bright Positive Calcium Indicator NCaMP7 Based on the mNeonGreen Fluorescent Protein.

Green fluorescent genetically encoded calcium indicators (GECIs) are the most popular tool for visualization of calcium dynamics in vivo. However, most of them are based on the EGFP protein and have similar molecular brightnesses. The NTnC indicator, which is composed of the mNeonGreen fluorescent protein with the insertion of troponin C, has higher brightness as compared to EGFP-based GECIs, but shows a limited inverted response with an ΔF/F of 1.

Isolation and Propagation of Single Inclusion-Derived Chlamydia Using Laser Microdissection.

Other than its routine application for capturing pure cell populations from fixed tissue sections for diverse downstream molecular assays, laser microdissection enables isolation of single live cells. Here we describe a method for the isolation of single Chlamydia trachomatis-infected cells using a laser microdissection system, in which the dissected samples are captured via gravity. Cells infected by C.

Modes of division and differentiation of neural stem cells.

Hippocampal neurogenesis presents an unorthodox form of neuronal plasticity and may be relevant for the normal or abnormal functioning of the human and animal brain. As production of new neurons decreases after birth, purposefully activating stem cells to create additional new neurons may augment brain function or slow a disease's progression. Here, we describe current models of hippocampal stem cell maintenance and differentiation, and emphasize key features of neural stem cells' turnover that may define hippocampal neurogenesis enhancement attempts' long-term consequences.

Triple S-Phase Labeling of Dividing Stem Cells.

Marking replicating DNA with multiple labels presents the possibility of revealing new features and mechanisms of DNA synthesis and cell division; however, progression beyond double labeling has been hampered by cross-reactivity of label detection and scarcity of appropriate labels. Here, we present a method for triple S-phase labeling of the dividing cells, with a fourth label used to mark cells actively engaged in cell-cycle progression (e.g.

Recombinant Human Peptidoglycan Recognition Proteins Reveal Antichlamydial Activity.

Peptidoglycan recognition proteins (PGLYRPs) are innate immune components that recognize the peptidoglycan and lipopolysaccharides of bacteria and exhibit antibacterial activity. Recently, the obligate intracellular parasite Chlamydia trachomatis was shown to have peptidoglycan. However, the antichlamydial activity of PGLYRPs has not yet been demonstrated.

Laser microdissection: A promising tool for exploring microorganisms and their interactions with hosts.

Laser microdissection is a method that allows for the isolation of homogenous cell populations from their native niches in tissues for downstream molecular assays. This method is widely used for genomic analysis, gene expression profiling and proteomic and metabolite assays in various fields of biology, but it remains an uncommon approach in microbiological research. In spite of the limited number of publications, laser microdissection was shown to be an extremely useful method for studying host-microorganism interactions in animals and plants, investigating bacteria within biofilms, identifying uncultivated bacteria and performing single prokaryotic cell analysis.

Recombinant fragilysin isoforms cause E-cadherin cleavage of intact cells and do not cleave isolated E-cadherin.

The fragilysin (BFT) is a protein secreted by enterotoxigenic Bacteroides fragilis strains. BFT contains zinc-binding motif which was found in the metzincins family of metalloproteinases. In this study, we generated three known recombinant isoforms of BFT using Escherichia coli, tested their activity and examined whether E-cadherin is a substrate for BFTs.

Isolation of single Chlamydia-infected cells using laser microdissection.

Chlamydia are obligate intracellular parasites of humans and animals that cause a wide range of acute and chronic infections. To elucidate the genetic basis of chlamydial parasitism, several approaches for making genetic modifications to Chlamydia have recently been reported. However, the lack of the available methods for the fast and effective selection of genetically modified bacteria restricts the application of genetic tools.