In Vivo Selection of S/MAR Sequences to Favour AAV Episomal Maintenance in Dividing Cells.

Adeno-associated viral (AAV) vector-mediated gene therapy has emerged as a promising alternative to liver transplantation for monogenic metabolic hepatic diseases. AAVs are non-integrative vectors that are maintained primarily as episomes in quiescent cells like adult hepatocytes. This quality, while advantageous from a safety perspective due to a decreased risk of insertional mutagenesis, becomes a disadvantage when treating dividing cells, as it inevitably leads to the loss of the therapeutic genome.

Enhanced AAV transduction across preclinical CNS models: A comparative study in human brain organoids with cross-species evaluations.

Viral vectors based on recombinant adeno-associated virus (rAAV) have become the most widely used system for therapeutic gene delivery in the central nervous system (CNS). Despite clinical safety and efficacy in neurological applications, a barrier to adoption of the current generation of vectors lies in their limited efficiency, resulting in limited transduction of CNS target cells. To address this limitation, researchers have bioengineered fit-for-purpose AAVs with improved CNS tropism and tissue penetration.

Gene editing in liver diseases.

The deliberate and precise modification of the host genome using engineered nucleases represents a groundbreaking advancement in modern medicine. Several clinical trials employing these approaches to address metabolic liver disorders have been initiated, with recent remarkable outcomes observed in patients with transthyretin amyloidosis, highlighting the potential of these therapies. Recent technological improvements, particularly CRISPR Cas9-based technology, have revolutionized gene editing, enabling in vivo modification of the cellular genome for therapeutic purposes.

Profile of plasma microRNAs as a potential biomarker of Wilson's disease.

Background: Wilson's disease (WD) is a rare condition resulting from autosomal recessive mutations in ATP7B, a copper transporter, manifesting with hepatic, neurological, and psychiatric symptoms. Timely diagnosis and appropriate treatment yield a positive prognosis, while delayed identification and/or insufficient therapy lead to a poor outcome. Our aim was to establish a prognostic method for WD by characterising biomarkers based on circulating microRNAs.

Protective role of RIPK1 scaffolding against HDV-induced hepatocyte cell death and the significance of cytokines in mice.

Hepatitis delta virus (HDV) infection represents the most severe form of human viral hepatitis; however, the mechanisms underlying its pathology remain incompletely understood. We recently developed an HDV mouse model by injecting adeno-associated viral vectors (AAV) containing replication-competent HBV and HDV genomes. This model replicates many features of human infection, including liver injury.

Deciphering the Role of Post-Translational Modifications and Cellular Location of Hepatitis Delta Virus (HDV) Antigens in HDV-Mediated Liver Damage in Mice.

Hepatitis D virus (HDV) infection represents the most severe form of chronic viral hepatitis. We have shown that the delivery of HDV replication-competent genomes to the hepatocytes using adeno-associated virus (AAV-HDV) as gene delivery vehicles offers a unique platform to investigate the molecular aspects of HDV and associated liver damage. For the purpose of this study, we generated HDV genomes modified by site-directed mutagenesis aimed to (i) prevent some post-translational modifications of HDV antigens (HDAgs) such as large-HDAg (L-HDAg) isoprenylation or short-HDAg (S-HDAg) phosphorylation; (ii) alter the localization of HDAgs within the subcellular compartments; and (iii) inhibit the right conformation of the delta ribozyme.

Topoisomerase Inhibitors Increase Episomal DNA Expression by Inducing the Integration of Episomal DNA in Hepatic Cells.

Gene therapy is a promising strategy to treat and cure most inherited metabolic liver disorders. Viral vectors such as those based on adeno-associated viruses (AAVs) and lentiviruses (LVs) are used as vehicles to deliver functional genes to affected hepatocytes. Adverse events associated with the use of high vector doses have motivated the use of small molecules as adjuvants to reduce the dose.

Cardiac Progenitor Cell Exosomal miR-935 Protects against Oxidative Stress.

Oxidative stress-induced myocardial apoptosis and necrosis are critically involved in ischemic infarction, and several sources of extracellular vesicles appear to be enriched in therapeutic activities. The central objective was to identify and validate the differential exosome miRNA repertoire in human cardiac progenitor cells (CPC). CPC exosomes were first analyzed by LC-MS/MS and compared by RNAseq with exomes of human mesenchymal stromal cells and human fibroblasts to define their differential exosome miRNA repertoire (exo-miR).

Understanding and Tackling Immune Responses to Adeno-Associated Viral Vectors.

As the clinical experience in adeno-associated viral (AAV) vector-based gene therapies is expanding, the necessity to better understand and control the host immune responses is also increasing. Immunogenicity of AAV vectors in humans has been linked to several limitations of the platform, including lack of efficacy due to antibody-mediated neutralization, tissue inflammation, loss of transgene expression, and in some cases, complement activation and acute toxicities. Nevertheless, significant knowledge gaps remain in our understanding of the mechanisms of immune responses to AAV gene therapies, further hampered by the failure of preclinical animal models to recapitulate clinical findings.

Stabilization of 14-3-3 protein-protein interactions with Fusicoccin-A decreases alpha-synuclein dependent cell-autonomous death in neuronal and mouse models.

Synucleinopathies are a group of neurodegenerative diseases without effective treatment characterized by the abnormal aggregation of alpha-synuclein (aSyn) protein. Changes in levels or in the amino acid sequence of aSyn (by duplication/triplication of the aSyn gene or point mutations in the encoding region) cause familial cases of synucleinopathies. However, the specific molecular mechanisms of aSyn-dependent toxicity remain unclear.

Rescue of infant progressive familial intrahepatic cholestasis type 3 mice by repeated dosing of AAV gene therapy.

Background & Aims: Gene therapy using recombinant adeno-associated virus (rAAV) vector carrying multidrug resistance protein 3 (MDR3) coding sequence (AAV8-MDR3) represents a potential curative treatment for progressive familial intrahepatic cholestasis type 3 (PFIC3), which presents in early childhood. However, patients with the severest form of PFIC3 should receive treatment early after detection to prevent irreversible hepatic fibrosis leading ultimately to liver transplantation or death. This represents a challenge for rAAV-based gene therapy because therapeutic efficacy is expected to wane as rAAV genomes are lost owing to hepatocyte division, and the formation of AAV-specific neutralising antibodies precludes re-administration.

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.

Photodynamic nasal SARS-CoV-2 decolonization shortens infectivity and influences specific T-Cell responses.

Background: The main objective was to evaluate the efficacy of intranasal photodynamic therapy (PDT) in SARS-CoV-2 mildly symptomatic carriers on decreasing the infectivity period. SARS-CoV-2-specific immune-stimulating effects and safety were also analysed.

Methods: We performed a randomized, placebo-controlled, clinical trial in a tertiary hospital (NCT05184205).

Treatment with the senolytics dasatinib/quercetin reduces SARS-CoV-2-related mortality in mice.

The enormous societal impact of the ongoing COVID-19 pandemic has been particularly harsh for some social groups, such as the elderly. Recently, it has been suggested that senescent cells could play a central role in pathogenesis by exacerbating the pro-inflammatory immune response against SARS-CoV-2. Therefore, the selective clearance of senescent cells by senolytic drugs may be useful as a therapy to ameliorate the symptoms of COVID-19 in some cases.

Gene therapy for liver diseases - progress and challenges.

Gene therapy is poised to revolutionize modern medicine, with seemingly unlimited potential for treating and curing genetic disorders. For otherwise incurable indications, including most inherited metabolic liver disorders, gene therapy provides a realistic therapeutic option. In this Review, we discuss gene supplementation and gene editing involving the use of recombinant adeno-associated virus (rAAV) vectors for the treatment of inherited liver diseases, including updates on several ongoing clinical trials that are producing promising results.

Gene Therapy in Combination with Nitrogen Scavenger Pretreatment Corrects Biochemical and Behavioral Abnormalities of Infant Citrullinemia Type 1 Mice.

Citrullinemia type I (CTLN1) is a rare autosomal recessive disorder caused by mutations in the gene encoding argininosuccinate synthetase 1 (ASS1) that catalyzes the third step of the urea cycle. CTLN1 patients suffer from impaired elimination of nitrogen, which leads to neurotoxic levels of circulating ammonia and urea cycle byproducts that may cause severe metabolic encephalopathy, death or irreversible brain damage. Standard of care (SOC) of CTLN1 consists of daily nitrogen-scavenger administration, but patients remain at risk of life-threatening decompensations.

Microglia and astrocyte activation is region-dependent in the α-synuclein mouse model of Parkinson's disease.

Inflammation is a common feature in neurodegenerative diseases that contributes to neuronal loss. Previously, we demonstrated that the basal inflammatory tone differed between brain regions and, consequently, the reaction generated to a pro-inflammatory stimulus was different. In this study, we assessed the innate immune reaction in the midbrain and in the striatum using an experimental model of Parkinson's disease.

Targeting Signaling Pathway Downstream of RIG-I/MAVS in the CNS Stimulates Production of Endogenous Type I IFN and Suppresses EAE.

Type I interferons (IFN), including IFNβ, play a protective role in multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE). Type I IFNs are induced by the stimulation of innate signaling, including via cytoplasmic RIG-I-like receptors. In the present study, we investigated the potential effect of a chimeric protein containing the key domain of RIG-I signaling in the production of CNS endogenous IFNβ and asked whether this would exert a therapeutic effect against EAE.

Rapid SARS-CoV-2 disinfection on distant surfaces with UV-C: The inactivation is affected by the type of material.

SARS-CoV-2 is responsible for the COVID-19 pandemic, which has caused almost 570 million infections and over six million deaths worldwide. To help curb its spread, solutions using ultraviolet light (UV) for quick virus inactivation inside buildings without human intervention could be very useful to reduce chances of contagion. The UV dose must be sufficient to inactivate the virus considering the different materials in the room, but it should not be too high, not to degrade the environment.

High value of Cu as a tool to evaluate the restoration of physiological copper excretion after gene therapy in Wilson's disease.

Wilson's disease (WD) is an inherited disorder of copper metabolism associated with mutations in gene. We have shown that the administration of an adeno-associated vector (AAV) encoding a mini version of human ATP7B (VTX-801) provides long-term correction of copper metabolism in a murine WD model. In preparation of a future clinical trial, we have evaluated by positron emission tomography (PET) the value of Cu biodistribution, excretion pattern, and blood kinetics as pharmacodynamic biomarkers of VTX-801 effects.