Mechanopharmacology: in vitro techniques to advance drug discovery.

Mechanopharmacology is an emerging interdisciplinary field that investigates drug action using biomechanically appropriate in vitro systems to the relevant (patho)physiology. This review outlines emerging technologies and techniques which aim to bridge the gap between mechanical cues influencing cellular biology and conventional pharmacology. We delve into the impact of mechanopharmacology on drug development in cancers and fibrotic diseases.

Nutritionally physiological cell culture medium and 3D culture influence breast tumour proteomics and anti-cancer drug effectiveness.

Many drugs have been discontinued during phase II/III breast cancer clinical trials due to lack of clinical efficacy, indicating shortcomings in predictive value of preclinical data. Nutrient availability in the tumour cell microenvironment and the dimensionality of in vitro tumour cells likely impact on drug responsiveness. Global proteomics experiments were conducted to assess the impact of nutrient availability and dimensionality of culture.

Dual-Purpose Aptamer-Based Sensors for Real-Time, Multiplexable Monitoring of Metabolites in Cell Culture Media.

The availability of high-frequency, real-time measurements of the concentrations of specific metabolites in cell culture systems will enable a deeper understanding of cellular metabolism and facilitate the application of good laboratory practice standards in cell culture protocols. However, currently available approaches to this end either are constrained to single-time-point and single-parameter measurements or are limited in the range of detectable analytes. Electrochemical aptamer-based (EAB) biosensors have demonstrated utility in real-time monitoring of analytes in blood and tissues.

Potassium dependent structural changes in the selectivity filter of HERG potassium channels.

The fine tuning of biological electrical signaling is mediated by variations in the rates of opening and closing of gates that control ion flux through different ion channels. Human ether-a-go-go related gene (HERG) potassium channels have uniquely rapid inactivation kinetics which are critical to the role they play in regulating cardiac electrical activity. Here, we exploit the K sensitivity of HERG inactivation to determine structures of both a conductive and non-conductive selectivity filter structure of HERG.

The molecular structure of an axle-less F-ATPase.

FF ATP synthase is a molecular rotary motor that can generate ATP using a transmembrane proton motive force. Isolated F-ATPase catalytic cores can hydrolyse ATP, passing through a series of conformational states involving rotation of the central γ rotor subunit and the opening and closing of the catalytic β subunits. Cooperativity in F-ATPase has long thought to be conferred through the γ subunit, with three key interaction sites between the γ and β subunits being identified.

Machine learning enables pan-cancer identification of mutational hotspots at persistent CTCF binding sites.

CCCTC-binding factor (CTCF) is an insulator protein that binds to a highly conserved DNA motif and facilitates regulation of three-dimensional (3D) nuclear architecture and transcription. CTCF binding sites (CTCF-BSs) reside in non-coding DNA and are frequently mutated in cancer. Our previous study identified a small subclass of CTCF-BSs that are resistant to CTCF knock down, termed persistent CTCF binding sites (P-CTCF-BSs).

Critical review of single-cell mechanotyping approaches for biomedical applications.

Accurate mechanical measurements of cells has the potential to improve diagnostics, therapeutics and advance understanding of disease mechanisms, where high-resolution mechanical information can be measured by deforming individual cells. Here we evaluate recently developed techniques for measuring cell-scale stiffness properties; while many such techniques have been developed, much of the work examining single-cell stiffness is impacted by difficulties in standardization and comparability, giving rise to large variations in reported mechanical moduli. We highlight the role of underlying mechanical theories driving this variability, and note opportunities to develop novel mechanotyping devices and theoretical models that facilitate convenient and accurate mechanical characterisation.

The series of conformational states adopted by rotorless F-ATPase during its hydrolysis cycle.

FF ATP synthase interchanges phosphate transfer energy and proton motive force via a rotary catalytic mechanism and isolated F-ATPase subcomplexes can also hydrolyze ATP to generate rotation of their central γ rotor subunit. As ATP is hydrolyzed, the F-ATPase cycles through a series of conformational states that mediates unidirectional rotation of the rotor. However, even in the absence of a rotor, the α and β subunits are still able to pass through a series of conformations, akin to those that generate rotation.

Molecular basis for GIGYF-TNRC6 complex assembly.

The GIGYF proteins interact with 4EHP and RNA-associated proteins to elicit transcript-specific translational repression. However, the mechanism by which the GIGYF1/2-4EHP complex is recruited to its target transcripts remain unclear. Here, we report the crystal structures of the GYF domains from GIGYF1 and GIGYF2 in complex with proline-rich sequences from the miRISC-binding proteins TNRC6C and TNRC6A, respectively.

Broadly neutralizing SARS-CoV-2 antibodies through epitope-based selection from convalescent patients.

Emerging variants of concern (VOCs) are threatening to limit the effectiveness of SARS-CoV-2 monoclonal antibodies and vaccines currently used in clinical practice; broadly neutralizing antibodies and strategies for their identification are therefore urgently required. Here we demonstrate that broadly neutralizing antibodies can be isolated from peripheral blood mononuclear cells of convalescent patients using SARS-CoV-2 receptor binding domains carrying epitope-specific mutations. This is exemplified by two human antibodies, GAR05, binding to epitope class 1, and GAR12, binding to a new epitope class 6 (located between class 3 and 5).

The FDA modernisation act 2.0: Bringing non-animal technologies to the regulatory table.

The FDA modernisation Act 2.0 marks a game-changing legislation enabling drug registration without the absolute requirement for the use of animals in safety toxicology assessment. We discuss landmark developments in the legislation under which the FDA operates and consider the implications of this most recent chapter in the evolution of the drug regulation pathway, focussing on new opportunities to embed microphysiological systems.

Changes within the central stalk of E. coli FF ATP synthase observed after addition of ATP.

FF ATP synthase functions as a biological generator and makes a major contribution to cellular energy production. Proton flow generates rotation in the F motor that is transferred to the F motor to catalyze ATP production, with flexible F/F coupling required for efficient catalysis. FF ATP synthase can also operate in reverse, hydrolyzing ATP and pumping protons, and in bacteria this function can be regulated by an inhibitory ε subunit.

ACE2 Expression in Organotypic Human Airway Epithelial Cultures and Airway Biopsies.

Coronavirus disease 2019 (COVID-19) caused by infection with the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is an acute respiratory disease with systemic complications. Therapeutic strategies for COVID-19, including repurposing (partially) developed drugs are urgently needed, regardless of the increasingly successful vaccination outcomes. We characterized two-dimensional (2D) and three-dimensional models (3D) to establish a physiologically relevant airway epithelial model with potential for investigating SARS-CoV-2 therapeutics.

Comprehensive multiplexed superfusion system enables physiological emulation in cell culture: exemplification by persistent circadian entrainment.

Cells and tissues are routinely cultured for biological research with findings being extrapolated to their host organ and tissue function. However, most samples are cultured and studied in unphysiological environments, without temporal variation in the biochemical cues that are ubiquitous . The artificiality of these conditions undermines the predictive value of cell culture studies.

Immunizations with diverse sarbecovirus receptor-binding domains elicit SARS-CoV-2 neutralizing antibodies against a conserved site of vulnerability.

Viral mutations are an emerging concern in reducing SARS-CoV-2 vaccination efficacy. Second-generation vaccines will need to elicit neutralizing antibodies against sites that are evolutionarily conserved across the sarbecovirus subgenus. Here, we immunized mice containing a human antibody repertoire with diverse sarbecovirus receptor-binding domains (RBDs) to identify antibodies targeting conserved sites of vulnerability.

Thunderstorm asthma in seasonal allergic rhinitis: The TAISAR study.

Background: Asthma epidemics associated with thunderstorms have had catastrophic effects on individuals and emergency services. Seasonal allergic rhinitis (SAR) is present in the vast majority of people who develop thunderstorm asthma (TA), but there is little evidence regarding risk factors for TA among the SAR population.

Objective: We sought to identify risk factors for a history of TA and hospital presentation in a cohort of individuals with SAR.

Managing Exacerbations in Thunderstorm Asthma: Current Insights.

Epidemic thunderstorm asthma (ETSA) occurs following a thunderstorm due to the interaction of environmental and immunologic factors. Whilst first reported in the 1980s, the world's largest event in Melbourne, Australia, on November 21, 2016 has led to a wealth of clinical literature seeking to identify its mechanisms, susceptibility risk factors, and management approaches. Thunderstorm asthma (TA) typically presents during an aeroallergen season in individuals sensitized to perennial rye grass pollen (RGP) in Australia, or fungus in the United Kingdom, in combination with meteorological factors such as thunderstorms and lightning activity.

The six steps of the complete F-ATPase rotary catalytic cycle.

FF ATP synthase interchanges phosphate transfer energy and proton motive force via a rotary catalysis mechanism. Isolated F-ATPase catalytic cores can hydrolyze ATP, passing through six intermediate conformational states to generate rotation of their central γ-subunit. Although previous structural studies have contributed greatly to understanding rotary catalysis in the F-ATPase, the structure of an important conformational state (the binding-dwell) has remained elusive.

High-throughput microfluidic compressibility cytometry using multi-tilted-angle surface acoustic wave.

Cellular mechanical properties (e.g. compressibility) are important biophysical markers in relation to cellular processes and functionality.

Endothelial Dysfunction in Atherosclerotic Cardiovascular Diseases and Beyond: From Mechanism to Pharmacotherapies.

The endothelium, a cellular monolayer lining the blood vessel wall, plays a critical role in maintaining multiorgan health and homeostasis. Endothelial functions in health include dynamic maintenance of vascular tone, angiogenesis, hemostasis, and the provision of an antioxidant, anti-inflammatory, and antithrombotic interface. Dysfunction of the vascular endothelium presents with impaired endothelium-dependent vasodilation, heightened oxidative stress, chronic inflammation, leukocyte adhesion and hyperpermeability, and endothelial cell senescence.