Role of YAP/TAZ in Cell Lineage Fate Determination and Related Signaling Pathways.

The penultimate effectors of the Hippo signaling pathways YAP and TAZ, are transcriptional co-activator proteins that play key roles in many diverse biological processes, ranging from cell proliferation, tumorigenesis, mechanosensing and cell lineage fate determination, to wound healing and regeneration. In this review, we discuss the regulatory mechanisms by which YAP/TAZ control stem/progenitor cell differentiation into the various major lineages that are of interest to tissue engineering and regenerative medicine applications. Of particular interest is the key role of YAP/TAZ in maintaining the delicate balance between quiescence, self-renewal, proliferation and differentiation of endogenous adult stem cells within various tissues/organs during early development, normal homeostasis and regeneration/healing.

An overview of signaling pathways regulating YAP/TAZ activity.

YAP and TAZ are ubiquitously expressed homologous proteins originally identified as penultimate effectors of the Hippo signaling pathway, which plays a key role in maintaining mammalian tissue/organ size. Presently, it is known that YAP/TAZ also interact with various non-Hippo signaling pathways, and have diverse roles in multiple biological processes, including cell proliferation, tissue regeneration, cell lineage fate determination, tumorigenesis, and mechanosensing. In this review, we first examine the various microenvironmental cues and signaling pathways that regulate YAP/TAZ activation, through the Hippo and non-Hippo signaling pathways.

Synthetic gene circuits for the detection, elimination and prevention of disease.

In living organisms, naturally evolved sensors that constantly monitor and process environmental cues trigger corrective actions that enable the organisms to cope with changing conditions. Such natural processes have inspired biologists to construct synthetic living sensors and signalling pathways, by repurposing naturally occurring proteins and by designing molecular building blocks de novo, for customized diagnostics and therapeutics. In particular, designer cells that employ user-defined synthetic gene circuits to survey disease biomarkers and to autonomously re-adjust unbalanced pathological states can coordinate the production of therapeutics, with controlled timing and dosage.

Covalent Functionalization by Cycloaddition Reactions of Pristine Defect-Free Graphene.

Based on a low-temperature scanning tunneling microscopy study, we present a direct visualization of a cycloaddition reaction performed for some specific fluorinated maleimide molecules deposited on graphene. Up to now, it was widely admitted that such a cycloaddition reaction can not happen without pre-existing defects. However, our study shows that the cycloaddition reaction can be carried out on a defect-free basal graphene plane at room temperature.

Toward a world of theranostic medication: Programming biological sentinel systems for therapeutic intervention.

Theranostic systems support diagnostic and therapeutic functions in a single integrated entity and enable precise spatiotemporal control of the generation of therapeutic molecules according to the individual patient's disease state, thereby maximizing the therapeutic outcome and minimizing side effects. These systems can also incorporate reporter systems equipped with a disease-sensing module that can be used to estimate the efficacy of treatment in vivo. Among these reporter systems, biological sentinel systems, such as viruses, bacteria, and mammalian cells, have great potential for use in the development of novel theranostic systems because of their ability to sense a variety of disease markers and secrete various therapeutic molecules.

Site-selective local fluorination of graphene induced by focused ion beam irradiation.

The functionalization of graphene remains an important challenge for numerous applications expected by this fascinating material. To keep advantageous properties of graphene after modification or functionalization of its structure, local approaches are a promising road. A novel technique is reported here that allows precise site-selective fluorination of graphene.

Novel theranostic agents for next-generation personalized medicine: small molecules, nanoparticles, and engineered mammalian cells.

Modern medicine is currently undergoing a paradigm shift from conventional disease treatments based on the diagnosis of a generalized disease state to a more personalized, customized treatment model based on molecular-level diagnosis. This uses novel biosensors that can precisely extract disease-related information from complex biological systems. Moreover, with the recent progress in chemical biology, materials science, and synthetic biology, it has become possible to simultaneously conduct diagnosis and targeted therapy (theranostics/theragnosis) by directly connecting the readout of a biosensor to a therapeutic output.

Prosthetic gene networks as an alternative to standard pharmacotherapies for metabolic disorders.

Synthetic biology makes inroads into clinical therapy with the debut of closed-loop prosthetic gene networks specifically designed to treat human diseases. Prosthetic networks are synthetic sensor/effector devices that could functionally integrate and interface with host metabolism to monitor disease states and coordinate appropriate therapeutic responses in a self-sufficient, timely and automatic manner. Prosthetic networks hold particular promise for the current global epidemic of closely interrelated metabolic disorders encompassing obesity, type 2 diabetes, hypertension and hyperlipidaemia, which arise from the unhealthy lifestyle and dietary factors in the modern urbanised world.

Tunneling spectroscopy measurements on hydrogen-bonded supramolecular polymers.

We studied the formation of hydrogen-bonded supramolecular polymers of Ethyl Hexyl Urea Toluene (EHUT) on a gold (111) surface by low temperature scanning tunneling microscopy. Tunneling spectroscopy performed along an individual molecule embedded in a self-assembled layer revealed strong changes in the value of the HOMO-LUMO gap. A variation of the LUMO state is attributed to the effect of space charge accumulation resulting from anisotropic adhesion of the molecule.

One- and two-photon absorption and emission properties of an oligo(phenylenethienylene)s series.

The photophysical and nonlinear absorption properties of an oligo(phenylenethienylene)s series (nTBT) are investigated in this article. The length of the chromophore is gradually increased from one to four phenylenethienylene repeating units in order to evaluate the effects of the electronic delocalization on the two-photon absorption cross sections (δ). According to the excitation anisotropy measurements and quantum chemical calculations, two electronic transitions with distinctive symmetries, 1Ag → 1Bu and 1Ag → 2Ag, are present in the low energy region of the linear absorption spectrum.

Synthetic mammalian gene circuits for biomedical applications.

Synthetic biology is the science of reassembling cataloged and standardized biological items in a systematic and rational manner to create and engineer functional biological designer devices, systems and organisms with novel and useful, preferably therapeutic functions. Synthetic biology has significantly advanced the design of complex genetic networks that can reprogram metabolic activities in mammalian cells and provide novel therapeutic strategies for future gene-based and cell-based therapies. Synthetic biology-inspired therapeutic strategies provide new opportunities for improving human health in the 21st century.

G protein-coupled receptors revisited: therapeutic applications inspired by synthetic biology.

G protein-coupled receptors (GPCRs) mediate the majority of cellular responses to hormones and neurotransmitters within the human body. They have much potential in the emerging field of synthetic biology, which is the rational, systematic design of biological systems with desired functionality. The responsiveness of GPCRs to a plethora of endogenous and exogenous ligands and stimuli make them ideal sensory receptor modules of synthetic gene networks.

Biomedically relevant circuit-design strategies in mammalian synthetic biology.

The development and progress in synthetic biology has been remarkable. Although still in its infancy, synthetic biology has achieved much during the past decade. Improvements in genetic circuit design have increased the potential for clinical applicability of synthetic biology research.

An overview of the diverse roles of G-protein coupled receptors (GPCRs) in the pathophysiology of various human diseases.

G-protein coupled receptors (GPCRs) modulate diverse cellular responses to the majority of neurotransmitters and hormones within the human body. They exhibit much structural and functional diversity, and are responsive to a plethora of endogenous (biogenic amines, cations, lipids, peptides, and glycoproteins) and exogenous (therapeutic drugs, photons, tastants, and odorants) ligands and stimuli. Due to the key roles of GPCRs in tissue/cell physiology and homeostasis, signaling pathways associated with GPCRs are implicated in the pathophysiology of various diseases, ranging from metabolic, immunological, and neurodegenerative disorders, to cancer and infectious diseases.

Generating long supramolecular pathways with a continuous density of states by physically linking conjugated molecules via their end groups.

Self-assembly of conjugated 2,5-dialkoxy-phenylene-thienylene-based oligomers on epitaxial monolayer graphene was studied in ultrahigh vacuum by low-temperature scanning tunneling microscopy (STM). The formation of long one-dimensional (1D) supramolecular chain-like structures has been observed, associated to a physical linking of their ends which involved the rotation of the end thiophene rings in order to allow π-π stacking of these end-groups. dI/dV maps taken at an energy corresponding to the excited states showed a continuous electronic density of states, which tentatively suggests that within such molecular chains conjugation of electrons is preserved even across physically linked molecules.

The peptide transport system Opt is involved in both nutrition and environmental sensing during growth of Lactococcus lactis in milk.

Lactococcus lactis is known to take up extracellular peptides via at least three distinct peptide transporters. The well-described oligopeptide transporter Opp alone is able to ensure the growth of L. lactis in milk, while the di- and tripeptide transporter DtpT is involved in a peptide-dependent signalling mechanism.

Watch the clock-engineering biological systems to be on time.

Inspired by natural time-keeping devices controlling the circadian clock, managing information processing in the brain and coordinating physiological activities on a daily (feeding and sleeping) or seasonal timescale (reproductive activity or hibernation), synthetic biologists have successfully assembled functional synthetic clocks from cataloged genetic components with standardized activities and arranging them in transcription circuits containing positive and negative feedback loops with integrated time-delay dynamics. While the positive feedback loop drives the clock like the (balance) spring in a mechanical watch the negative time-delay circuit represents the pulse generator defining a minimal time unit and precision of the clock like the pendulum fallback or the movement of the balance wheel in a classical mechanic watch. This basic design principle enabled the construction of a variety of synthetic oscillators whose design details are concisely covered in this review.

Mammalian synthetic biology--from tools to therapies.

Mammalian synthetic biology holds the promise of providing novel therapeutic strategies, and the first success stories are beginning to be reported. Here we focus on the latest generation of mammalian transgene control devices, highlight state-of-the-art synthetic gene network design, and cover prototype therapeutic circuits. These will have an impact on future gene- and cell-based therapies and help bring drug discovery into a new era.

RepTAGs: universal tags for isolation and labeling of proteins, for labeling live mammalian cells and for drug discovery.

Methods for specific immobilization, isolation and labeling of proteins are central to the elucidation of cellular functions. Based on bacterial repressor proteins, which bind to specific target sequences in response to small molecules (macrolide and tetracycline antibiotics) or environmental parameters (temperature), we have developed a set of protein tags (RepTAGs), which enable reversible immobilization of the protein of interest on a solid support for the isolation and quantification as well as for the specific labeling of target proteins with fluorescent dyes for tracking them within a complex protein mixture. Similarly, live mammalian cells were specifically labeled with a fluorescent operator sequence bound to RepTAGs, which were directed towards the cell surface for easy discrimination between transfected and untransfected cell populations.

Corynebacterium hansenii sp. nov., an alpha-glucosidase-negative bacterium related to Corynebacterium xerosis.

A novel strain, C-138(T), belonging to the genus Corynebacterium was isolated from a severe thigh liposarcoma infection and its differentiation from Corynebacterium xerosis and Corynebacterium freneyi is described. Analysis of 16S rRNA gene sequences, rpoB sequences and the PCR profile of the 16S-23S spacer regions was not conclusive enough to differentiate strain C-138(T) from C. xerosis and C.

A synthetic time-delay circuit in mammalian cells and mice.

Time-delay circuitries in which a transcription factor processes independent input parameters can modulate NF-kappaB activation, manage quorum-sensing cross-talk, and control the circadian clock. We have constructed a synthetic mammalian gene network that processes four different input signals to control either immediate or time-delayed transcription of specific target genes. BirA-mediated ligation of biotin to a biotinylation signal-containing VP16 transactivation domain triggers heterodimerization of chimeric VP16 to a streptavidin-linked tetracycline repressor (TetR).

A novel mammalian expression system derived from components coordinating nicotine degradation in arthrobacter nicotinovorans pAO1.

We describe the design and detailed characterization of 6-hydroxy-nicotine (6HNic)-adjustable transgene expression (NICE) systems engineered for lentiviral transduction and in vivo modulation of angiogenic responses. Arthrobacter nicotinovorans pAO1 encodes a unique catabolic machinery on its plasmid pAO1, which enables this Gram-positive soil bacterium to use the tobacco alkaloid nicotine as the exclusive carbon source. The 6HNic-responsive repressor-operator (HdnoR-O(NIC)) interaction, controlling 6HNic oxidase production in A.

Tobacco smoke as inducer for gas phase-controlled transgene expression in mammalian cells and mice.

Capitalizing on components evolved to metabolize ethanol in Aspergillus nidulans, we previously designed the first molecular gas-gene expression interface using gaseous acetaldehyde as the major inducer. This fungus-derived acetaldehyde-inducible gene regulation (AIR) system operated perfectly and enabled precise and reversible transgene expression dosing in a variety of mammalian cells. We now validate the use of mainstream cigarette smoke typically containing acetaldehyde at regulation-effective nontoxic concentrations as a noninvasive modality to adjust transgene transcription in mammalian cells and mice.

CellMAC: a novel technology for encapsulation of mammalian cells in cellulose sulfate/pDADMAC capsules assembled on a transient alginate/Ca2+ scaffold.

Microencapsulation of desired mammalian cell phenotypes in biocompatible polymer matrices represents a powerful technology for cell-based therapies and biopharmaceutical manufacturing of protein therapeutics. We have pioneered a novel jet break-up-compatible process for encapsulation of mammalian cells in cellulose sulfate (CS)/poly-diallyl-dimethyl-ammoniumchloride (pDADMAC) (CellMAC) capsules. CS and pDADMAC polymerize on a transient ad hoc co-assembled Ca2+/alginate scaffold and form homogenous capsules following dissolution of the alginate core by Ca2+ chelating agents.

Engineered Streptomyces quorum-sensing components enable inducible siRNA-mediated translation control in mammalian cells and adjustable transcription control in mice.

Background: Recent advances in functional genomics, gene therapy, tissue engineering, drug discovery and biopharmaceuticals production have been fostered by precise small-molecule-mediated fine-tuning of desired transgenes.

Methods: Capitalizing on well-evolved quorum-sensing regulatory networks in Streptomyces coelicolor we have designed a mammalian regulation system inducible by the non-toxic butyrolactone SCB1. Fusion of the S.