Bovine tracheal organoids for studying Mycoplasma bovis respiratory infections.

In vitro three-dimensional organoid models simulate key aspects of the structure and function of in vivo organs and have been used to study physiology, host-pathogen interactions, pathogenesis and pharmacodynamics. Although most organoid studies have been developed using human or mouse tissues, recent advancements have enabled the establishment of intestinal and respiratory tract organoids from domestic animal samples. Mycoplasma bovis causes chronic respiratory tract infections in cattle with significant health and economic consequences.

Uncovering strain- and age-dependent innate immune responses to SARS-CoV-2 infection in air-liquid-interface cultured nasal epithelia.

Continuous assessment of the impact of SARS-CoV-2 on the host at the cell-type level is crucial for understanding key mechanisms involved in host defense responses to viral infection. We investigated host response to ancestral-strain and Alpha-variant SARS-CoV-2 infections within air-liquid-interface human nasal epithelial cells from younger adults (26-32 Y) and older children (12-14 Y) using single-cell RNA-sequencing. Ciliated and secretory-ciliated cells formed the majority of highly infected cell-types, with the latter derived from ciliated lineages.

Renin-Angiotensin Inhibitor, Captopril, Attenuates Growth of Patient-Derived Colorectal Liver Metastasis Organoids.

The recurrence of colorectal liver metastasis (CRLM) following liver resection is common; approximately 40% of patients will experience tumor recurrence post-surgery. Renin-angiotensin inhibitors (RASis) have been shown to attenuate the growth and progression of CRLM in pre-clinical models following liver resection. This study examined the efficacy of the RASi captopril on patient-derived colorectal liver metastasis organoids.

Trabid patient mutations impede the axonal trafficking of adenomatous polyposis coli to disrupt neurite growth.

(human Trabid) missense mutations have been identified in children diagnosed with a range of congenital disorders including reduced brain size, but how Trabid regulates neurodevelopment is not understood. We have characterized these patient mutations in cells and mice to identify a key role for Trabid in the regulation of neurite growth. One of the patient mutations flanked the catalytic cysteine of Trabid and its deubiquitylating (DUB) activity was abrogated.

Assessment of hepatitis B virus infection and interhost cellular responses using intrahepatic cholangiocyte organoids.

The intrahepatic cholangiocyte organoids (ICOs) model was evaluated for host differences in hepatitis B virus (HBV) infection, cellular responses, antiviral and immunomodulator responses. Twelve ICOs generated from liver resections and biopsies were assessed for metabolic markers and functional HBV entry receptor expression throughout differentiation. Structural changes relevant to HBV infection were characterized using histology, confocal, and electron microscopy examinations.

Assessment of HBV infection and inter-host cellular responses using intrahepatic cholangiocyte organoids.

Intrahepatic cholangiocyte organoids (ICOs) model was evaluated for host differences in hepatitis B virus (HBV) infection, cellular responses, antiviral, and immunomodulator responses. Twelve ICOs generated from liver resections and biopsies were assessed for metabolic markers and functional HBV entry receptor expression throughout differentiation. Structural changes relevant to HBV infection were characterized using histology, confocal, and electron microscopy examinations.

Broad immunity to SARS-CoV-2 variants of concern mediated by a SARS-CoV-2 receptor-binding domain protein vaccine.

Background: The SARS-CoV-2 global pandemic has fuelled the generation of vaccines at an unprecedented pace and scale. However, many challenges remain, including: the emergence of vaccine-resistant mutant viruses, vaccine stability during storage and transport, waning vaccine-induced immunity, and concerns about infrequent adverse events associated with existing vaccines.

Methods: We report on a protein subunit vaccine comprising the receptor-binding domain (RBD) of the ancestral SARS-CoV-2 spike protein, dimerised with an immunoglobulin IgG1 Fc domain.

Assessment of Pre-Clinical Liver Models Based on Their Ability to Predict the Liver-Tropism of Adeno-Associated Virus Vectors.

The liver is a prime target for gene therapies using recombinant adeno-associated viral vectors. Multiple clinical trials have been undertaken for this target in the past 15 years; however, we are still to see market approval of the first liver-targeted adeno-associated virus (AAV)-based gene therapy. Inefficient expression of the therapeutic transgene, vector-induced liver toxicity and capsid, and/or transgene-mediated immune responses reported at high vector doses are the main challenges to date.

Epigenetic Silencing of RIPK3 in Hepatocytes Prevents MLKL-mediated Necroptosis From Contributing to Liver Pathologies.

Background & Aims: Necroptosis is a highly inflammatory mode of cell death that has been implicated in causing hepatic injury including steatohepatitis/ nonalcoholic steatohepatitis (NASH); however, the evidence supporting these claims has been controversial. A comprehensive, fundamental understanding of cell death pathways involved in liver disease critically underpins rational strategies for therapeutic intervention. We sought to define the role and relevance of necroptosis in liver pathology.

Captopril, a Renin-Angiotensin System Inhibitor, Attenuates Tumour Progression in the Regenerating Liver Following Partial Hepatectomy.

(1) Liver regeneration following partial hepatectomy for colorectal liver metastasis (CRLM) has been linked to tumour recurrence. Inhibition of the renin−angiotensin system (RASi) attenuates CRLM growth in the non-regenerating liver. This study investigates whether RASi exerts an antitumour effect within the regenerating liver following partial hepatectomy for CRLM and examines RASi-induced changes in the tumour immune microenvironment; (2) CRLM in mice was induced via intrasplenic injection of mouse colorectal tumour cells, followed by splenectomy on Day 0.

Air-Liquid-Interface Differentiated Human Nose Epithelium: A Robust Primary Tissue Culture Model of SARS-CoV-2 Infection.

The global urgency to uncover medical countermeasures to combat the COVID-19 pandemic caused by the severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has revealed an unmet need for robust tissue culture models that faithfully recapitulate key features of human tissues and disease. Infection of the nose is considered the dominant initial site for SARS-CoV-2 infection and models that replicate this entry portal offer the greatest potential for examining and demonstrating the effectiveness of countermeasures designed to prevent or manage this highly communicable disease. Here, we test an air-liquid-interface (ALI) differentiated human nasal epithelium (HNE) culture system as a model of authentic SARS-CoV-2 infection.

Frizzled Activates β-Catenin-Dependent and β-Catenin-Independent Wnt Signalling Pathways During Developmental Morphogenesis: Implications for Therapeutic Targeting in Colorectal Cancer.

Frizzled activates β-catenin-dependent and β-catenin-independent Wnt signalling pathways, is highly conserved through evolution from the ancient phylum hydra to man, plays essential roles in stem cells, tissue homeostasis and regeneration in the adult, and is upregulated in diverse cancers. Much of what is known about the core components of the Wnt signalling pathways was derived from studying the function of Frizzled orthologues in the development of lower organism. As we interrogate Frizzled signalling and function for therapeutic targeting in cancer, it is timely to revisit lower organisms to gain insight into the context dependent and dynamic nature of Wnt signalling for effective drug design.

Clinical stage drugs targeting inhibitor of apoptosis proteins purge episomal Hepatitis B viral genome in preclinical models.

A major unmet clinical need is a therapeutic capable of removing hepatitis B virus (HBV) genome from the liver of infected individuals to reduce their risk of developing liver cancer. A strategy to deliver such a therapy could utilize the ability to target and promote apoptosis of infected hepatocytes. Presently there is no clinically relevant strategy that has been shown to effectively remove persistent episomal covalently closed circular HBV DNA (cccDNA) from the nucleus of hepatocytes.

Captopril, a Renin-Angiotensin System Inhibitor, Attenuates Features of Tumor Invasion and Down-Regulates C-Myc Expression in a Mouse Model of Colorectal Cancer Liver Metastasis.

(1) Background: Recent clinical and experimental data suggests that the liver's regenerative response following partial hepatectomy can stimulate tumor recurrence in the liver remnant. The Wnt/β-catenin pathway plays important roles in both colorectal cancer carcinogenesis and liver regeneration. Studies have shown that the Wnt/β-catenin pathway regulates multiple renin-angiotensin system (RAS) genes, whilst RAS inhibition (RASi) reduces tumor burden and progression.

Investigating virus-host cell interactions: Comparative binding forces between hepatitis C virus-like particles and host cell receptors in 2D and 3D cell culture models.

Cell cultures have been successfully used to study hepatitis C virus (HCV) for many years. However, most work has been done using traditional, 2-dimensional (2D) cell cultures (cells grown as a monolayer in growth flasks or dishes). Studies have shown that when cells are grown suspended in an extra-cellular-matrix-like material, they develop into spherical, 'organoid' arrangements of cells (3D growth) that display distinct differences in morphological and functional characteristics compared to 2D cell cultures.

The Hepatitis B Virus Pre-Core Protein p22 Activates Wnt Signaling.

An emerging theme for Wnt-addicted cancers is that the pathway is regulated at multiple steps via various mechanisms. Infection with hepatitis B virus (HBV) is a major risk factor for liver cancer, as is deregulated Wnt signaling, however, the interaction between these two causes is poorly understood. To investigate this interaction, we screened the effect of the various HBV proteins for their effect on Wnt/β-catenin signaling and identified the pre-core protein p22 as a novel and potent activator of TCF/β-catenin transcription.

Targeting Wnt Signaling for the Treatment of Gastric Cancer.

The Wnt signaling pathway is evolutionarily conserved, regulating both embryonic development and maintaining adult tissue homeostasis. Wnt signaling controls several fundamental cell functions, including proliferation, differentiation, migration, and stemness. It therefore plays an important role in the epithelial homeostasis and regeneration of the gastrointestinal tract.

Wnt Signaling in Cancer: Not a Binary ON:OFF Switch.

In the March 1 issue of , we identified the Wnt receptor Fzd7 as an attractive therapeutic target for the treatment of gastric cancer. In summary, we showed that pharmacological inhibition of Wnt receptors, or genetic deletion of , blocks the initiation and growth of gastric tumors. Inhibiting Fzd receptors, specifically Fzd7, inhibits the growth of gastric cancer cells even in the presence of () mutation.

HBV-related hepatocarcinogenesis: the role of signalling pathways and innovative ex vivo research models.

Background: Hepatitis B virus (HBV) is the leading cause of liver cancer, but the mechanisms by which HBV causes liver cancer are poorly understood and chemotherapeutic strategies to cure liver cancer are not available. A better understanding of how HBV requisitions cellular components in the liver will identify novel therapeutic targets for HBV associated hepatocellular carcinoma (HCC).

Main Body: The development of HCC involves deregulation in several cellular signalling pathways including Wnt/FZD/β-catenin, PI3K/Akt/mTOR, IRS1/IGF, and Ras/Raf/MAPK.

The Function of Cells in the Gastric Antrum Does Not Require or In Vivo.

The extreme chemical and mechanical forces endured by the gastrointestinal tract drive a constant renewal of the epithelial lining. Stem cells of the intestine and stomach, marked by the cell surface receptor , preserve the cellular status-quo of their respective tissues through receipt and integration of multiple cues from the surrounding niche. Wnt signalling is a critical niche component for gastrointestinal stem cells and we have previously shown that the Wnt receptor, (), is required for gastric homeostasis and the function of intestinal stem cells.

Is Required for Wnt Signaling in Gastric Tumors with and Without Mutations.

A subset of patients with gastric cancer have mutations in genes that participate in or regulate Wnt signaling at the level of ligand (Wnt) receptor (Fzd) binding. Moreover, increased Fzd expression is associated with poor clinical outcome. Despite these findings, there are no studies investigating the potential of targeting Wnt receptors for treating gastric cancer, and the specific Wnt receptor transmitting oncogenic Wnt signaling in gastric cancer is unknown.

PI3K activation in neural stem cells drives tumorigenesis which can be ameliorated by targeting the cAMP response element binding protein.

Background: Hyperactivation of phosphoinositide 3-kinase (PI3K) signaling is common in cancers, but the precise role of the pathway in glioma biology remains to be determined. Some understanding of PI3K signaling mechanisms in brain cancer comes from studies on neural stem/progenitor cells (NSPCs), where signals transmitted via the PI3K pathway cooperate with other intracellular pathways and downstream transcription factors to regulate critical cell functions.

Methods: To investigate the role of the PI3K pathway in glioma initiation and development, we generated a mouse model targeting the inducible expression of a PIK3CAH1047A oncogenic mutant and deletion of the PI3K negative regulator, phosphatase and tensin homolog (PTEN), to NSPCs.

Wnt Signalling in Gastrointestinal Epithelial Stem Cells.

Wnt signalling regulates several cellular functions including proliferation, differentiation, apoptosis and migration, and is critical for embryonic development. Stem cells are defined by their ability for self-renewal and the ability to be able to give rise to differentiated progeny. Consequently, they are essential for the homeostasis of many organs including the gastrointestinal tract.

The Central Role of Wnt Signaling and Organoid Technology in Personalizing Anticancer Therapy.

The Wnt pathway is at the heart of organoid technology, which is set to revolutionize the cancer field. We can now predetermine a patient's response to any given anticancer therapy by exposing tumor organoids established from the patient's own tumor. This cutting-edge biomedical platform translates to patients being treated with the correct drug at the correct dose from the outset, a truly personalized and precise medical approach.