A chemogenetic approach for dopamine imaging with tunable sensitivity.

Genetically-encoded dopamine (DA) sensors enable high-resolution imaging of DA release, but their ability to detect a wide range of extracellular DA levels, especially tonic versus phasic DA release, is limited by their intrinsic affinity. Here we show that a human-selective dopamine receptor positive allosteric modulator (PAM) can be used to boost sensor affinity on-demand. The PAM enhances DA detection sensitivity across experimental preparations (in vitro, ex vivo and in vivo) via one-photon or two-photon imaging.

Sampling bias corrections for accurate neural measures of redundant, unique, and synergistic information.

Shannon Information theory has long been a tool of choice to measure empirically how populations of neurons in the brain encode information about cognitive variables. Recently, Partial Information Decomposition (PID) has emerged as principled way to break down this information into components identifying not only the unique information carried by each neuron, but also whether relationships between neurons generate synergistic or redundant information. While it has been long recognized that Shannon information measures on neural activity suffer from a (mostly upward) limited sampling estimation bias, this issue has largely been ignored in the burgeoning field of PID analysis of neural activity.

Sensitive multicolor indicators for monitoring norepinephrine in vivo.

Genetically encoded indicators engineered from G-protein-coupled receptors are important tools that enable high-resolution in vivo neuromodulator imaging. Here, we introduce a family of sensitive multicolor norepinephrine (NE) indicators, which includes nLightG (green) and nLightR (red). These tools report endogenous NE release in vitro, ex vivo and in vivo with improved sensitivity, ligand selectivity and kinetics, as well as a distinct pharmacological profile compared with previous state-of-the-art GRAB indicators.

ASTRA: a deep learning algorithm for fast semantic segmentation of large-scale astrocytic networks.

Changes in the intracellular calcium concentration are a fundamental fingerprint of astrocytes, the main type of glial cell. Astrocyte calcium signals can be measured with two-photon microscopy, occur in anatomically restricted subcellular regions, and are coordinated across astrocytic networks. However, current analytical tools to identify the astrocytic subcellular regions where calcium signals occur are time-consuming and extensively rely on user-defined parameters.

Characterization of the interactome profiling of DnaK in cancer cells reveals interference with key cellular pathways.

Chaperone proteins are redundant in nature and, to achieve their function, they bind a large repertoire of client proteins. DnaK is a bacterial chaperone protein that recognizes misfolded and aggregated proteins and drives their folding and intracellular trafficking. Some Mycoplasmas are associated with cancers, and we demonstrated that infection with a strain of isolated in our lab promoted lymphoma in a mouse model.

A deep-learning approach for online cell identification and trace extraction in functional two-photon calcium imaging.

In vivo two-photon calcium imaging is a powerful approach in neuroscience. However, processing two-photon calcium imaging data is computationally intensive and time-consuming, making online frame-by-frame analysis challenging. This is especially true for large field-of-view (FOV) imaging.

Complementary encoding of spatial information in hippocampal astrocytes.

Calcium dynamics into astrocytes influence the activity of nearby neuronal structures. However, because previous reports show that astrocytic calcium signals largely mirror neighboring neuronal activity, current information coding models neglect astrocytes. Using simultaneous two-photon calcium imaging of astrocytes and neurons in the hippocampus of mice navigating a virtual environment, we demonstrate that astrocytic calcium signals encode (i.

Analysis of DnaK Expression from a Strain of in Infected HCT116 Human Colon Carcinoma Cells.

Several species of mycoplasmas, including , are associated with certain human cancers. We previously isolated and characterized in our laboratory a strain of human mycoplasma subtype (MF-I1) able to induce lymphoma in a Severe Combined Immuno-Deficient (SCID) mouse model, and we demonstrated that its chaperone protein, DnaK, binds and reduces functions of human poly-ADP ribose polymerase-1 (PARP1) and ubiquitin carboxyl-terminal hydrolase protein-10 (USP10), which are required for efficient DNA repair and proper p53 activities, respectively. We also showed that other bacteria associated with human cancers (including , , , , and ) have closely related DnaK proteins, indicating a potential common mechanism of cellular transformation.

In vivo and in vitro cell-based model of lung adenocarcinoma from patients with pleural effusion.

Lung adenocarcinoma (LAC) is a common and aggressive form of lung cancer that is increasing in incidence among never smokers at a younger age. Current treatment of patients with LAC is insufficient and there is a need for identification of effective biomarkers and development of therapeutic targets. These demands require also improved models for in vivo and in vitro experimentation.

Exogenous bacterial DnaK increases protein kinases activity in human cancer cell lines.

Background: Studies of molecular mechanisms underlying tumor cell signaling highlighted a critical role for kinases in carcinogenesis and cancer progression. To this regard, protein kinases regulates a number of critical cellular pathways by adding phosphate groups to specific substrates. For this reason, their involvement in the complex interactions between the human microbiota and cancer cells to determine therapy and tumor progression outcome is becoming increasingly relevant.

Tampering of Viruses and Bacteria with Host DNA Repair: Implications for Cellular Transformation.

A reduced ability to properly repair DNA is linked to a variety of human diseases, which in almost all cases is associated with an increased probability of the development of cellular transformation and cancer. DNA damage, that ultimately can lead to mutations and genomic instability, is due to many factors, such as oxidative stress, metabolic disorders, viral and microbial pathogens, excess cellular proliferation and chemical factors. In this review, we examine the evidence connecting DNA damage and the mechanisms that viruses and bacteria have evolved to hamper the pathways dedicated to maintaining the integrity of genetic information, thus affecting the ability of their hosts to repair the damage(s).

Mycoplasmas-Host Interaction: Mechanisms of Inflammation and Association with Cellular Transformation.

Mycoplasmas are the smallest and simplest self-replicating prokaryotes. Located everywhere in nature, they are widespread as parasites of humans, mammals, reptiles, fish, arthropods, and plants. They usually exhibiting organ and tissue specificity.

Role of Mycoplasma Chaperone DnaK in Cellular Transformation.

Studies of the human microbiome have elucidated an array of complex interactions between prokaryotes and their hosts. However, precise bacterial pathogen-cancer relationships remain largely elusive, although several bacteria, particularly those establishing persistent intra-cellular infections, like mycoplasmas, can alter host cell cycles, affect apoptotic pathways, and stimulate the production of inflammatory substances linked to DNA damage, thus potentially promoting abnormal cell growth and transformation. Consistent with this idea, in vivo experiments in several chemically induced or genetically deficient mouse models showed that germ-free conditions reduce colonic tumor formation.

Mycoplasma promotes malignant transformation in vivo, and its DnaK, a bacterial chaperone protein, has broad oncogenic properties.

We isolated a strain of human mycoplasma that promotes lymphomagenesis in SCID mice, pointing to a p53-dependent mechanism similar to lymphomagenesis in uninfected p53 SCID mice. Additionally, mycoplasma infection in vitro reduces p53 activity. Immunoprecipitation of p53 in mycoplasma-infected cells identified several mycoplasma proteins, including DnaK, a member of the Hsp70 chaperon family.

Anti-inflammatory effects of HS during acute bacterial infection: a review.

Hydrogen sulfide (HS), previously only considered a toxic environmental air pollutant, is now increasingly recognized as an important signaling molecule able to modulate several cellular pathways in many human tissues. As demonstrated in recent studies, HS is produced endogenously in response to different cellular stimuli and plays different roles in controlling a number of physiological responses. The precise role of HS in inflammation is still largely unknown.

Extracellular matrix alterations in the ketamine model of schizophrenia.

The neural extracellular matrix (ECM) plays an important role in regulation of perisomatic GABAergic inhibition and synaptic plasticity in the hippocampus and cortex. Decreased labeling of perineuronal nets, a form of ECM predominantly associated with parvalbumin-expressing interneurons in the brain, has been observed in post-mortem studies of schizophrenia patients, specifically, in brain areas such as prefrontal cortex, entorhinal cortex, and amygdala. Moreover, glial ECM in the form of dandelion clock-like structures was reported to be altered in schizophrenia patients.

Class 3 semaphorins induce F-actin reorganization in human dendritic cells: Role in cell migration.

Class 3 semaphorins (Semas) are soluble proteins that are well recognized for their role in guiding axonal migration during neuronal development. In the immune system, Sema3A has been shown to influence murine dendritic cell (DC) migration by signaling through a neuropilin (NRP)-1/plexin-A1 coreceptor axis. Potential roles for class 3 Semas in human DCs have yet to be described.

Altered expression pattern of Nrf2/HO-1 axis during accelerated-senescence in HIV-1 transgenic rat.

Chronic oxidative stress plays a central role in the pathogenesis of many diseases, including HIV-1 associated disorders. Concomitantly with the decline of endogenous antioxidant systems, it was reported that HIV-1-related proteins increase the production of radical species in cells and tissues that are not directly infected by the virus. In the context of HIV-1 infection, the role of Nrf2, a key transcription factor that contributes to the maintenance of cellular redox homeostasis, remains largely uncharacterized.

Sulfur compounds block MCP-1 production by Mycoplasma fermentans-infected macrophages through NF-κB inhibition.

Background And Aims: Hydrogen sulfide (H2S), together with nitric oxide (NO) and carbon monoxide (CO), belongs to a family of endogenous signaling mediators termed "gasotransmitters". Recent studies suggest that H2S modulates many cellular processes and it has been recognized to play a central role in inflammation, in the cardiovascular and nervous systems. By infecting monocytes/macrophages with Mycoplasma fermentans (M.

B cell lymphoma in HIV transgenic mice.

Background: Human Immunodeficiency Virus Type I (HIV-1) infection is associated with a high incidence of B-cell lymphomas. The role of HIV in these lymphomas is unclear and currently there are no valid in vivo models for better understanding HIV-related lymphomagenesis. Transgenic (Tg) 26 mice have a 7.

Rapid generation of functional dopaminergic neurons from human induced pluripotent stem cells through a single-step procedure using cell lineage transcription factors.

Current protocols for in vitro differentiation of human induced pluripotent stem cells (hiPSCs) to generate dopamine (DA) neurons are laborious and time-expensive. In order to accelerate the overall process, we have established a fast protocol by expressing the developmental transcription factors ASCL1, NURR1, and LMX1A. With this method, we were able to generate mature and functional dopaminergic neurons in as few as 21 days, skipping all the intermediate steps for inducting and selecting embryoid bodies and rosette-neural precursors.

Role of Btg2 in the progression of a PDGF-induced oligodendroglioma model.

Tumor progression is a key aspect in oncology. Not even the overexpression of a powerful oncogenic stimulus such as platelet derived growth factor-B (PDGF-B) is sufficient per se to confer full malignancy to cells. In previous studies we showed that neural progenitors overexpressing PDGF-B need to undergo progression to acquire the capability to give rise to secondary tumor following transplant.

The series of molecular conductors and superconductors ET4[AFe(C2O4)3]·PhX (ET = bis(ethylenedithio)tetrathiafulvalene; (C2O4)2- = oxalate; A+ = H3O+, K+; X = F, Cl, Br, and I): influence of the halobenzene guest molecules on the crystal structure and superconducting properties.

An extensive series of radical salts formed by the organic donor bis(ethylenedithio)tetrathiafulvalene (ET), the paramagnetic tris(oxalato)ferrate(III) anion [Fe(C(2)O(4))(3)](3-), and halobenzene guest molecules has been synthesized and characterized. The change of the halogen atom in this series has allowed the study of the effect of the size and charge polarization on the crystal structures and physical properties while keeping the geometry of the guest molecule. The general formula of the salts is ET(4)[A(I)Fe(C(2)O(4))(3)]·G with A/G = H(3)O(+)/PhF (1); H(3)O(+)/PhCl (2); H(3)O(+)/PhBr (3), and K(+)/PhI (4), (crystal data at room temperature: (1) monoclinic, space group C2/c with a = 10.

Molecular conductors based on the mixed-valence polyoxometalates [SMo12O40]n- (n = 3 and 4) and the organic donors bis(ethylenedithio)tetrathiafulvalene and bis(ethylenedithio)tetraselenafulvalene.

The synthesis, crystal structure, and physical characterization of two new radical salts formed by the organic donors bis(ethylenedithio)tetrathiafulvalene (ET) and bis(ethylenediseleno)tetrathiafulvalene (BETS) and the Keggin polyoxometalate (POM) [SMo(12)O(40)](n-) are reported. The salts isolated are ET(8)[SMo(12)O(40)] x 10 H(2)O (1) (crystal data: (1) monoclinic, space group I2/m with a = 13.9300(10) A, b = 43.

Modular synthesis of heterobimetallic salen structures using metal templation.

A modular and general synthetic method is disclosed for nonsymmetrical heterobimetallic bis-salphen structures starting from a series of synthetically convenient monometalated triimine precursors. This methodology permits the introduction of various combinations of metal ions within the bis-salphen framework potentially useful in multifunctional materials.