The oxygen puzzle in FLASH radiotherapy: A comprehensive review and experimental outlook.

FLASH radiotherapy is attracting increasing interest because it maintains tumor control while inflicting less damage to normal tissues compared to conventional radiotherapy. This sparing effect, the so-called FLASH effect, is achieved when radiation is delivered at ultra-high dose rates (≥40 Gy/s). Although the FLASH effect has already been demonstrated in several preclinical models, a complete mechanistic description explaining why tumors and normal tissues respond differently is still missing. None of the current hypotheses fully explains the experimental evidence. A common point between many of these is the role of oxygen, which is described as a major factor, either through transient hypoxia in the form of dissolved molecules, or reactive oxygen species (ROS). Therefore, this review focuses on both forms of this molecule, retracing old and more recent theories, while proposing new mechanisms that could provide a complete description of the FLASH effect based on preclinical and experimental evidence. In addition, this manuscript describes a set of experiments designed to provide the FLASH community with new tools for exploring the post-irradiation fate of ROS and their potential biological implications.

Solid lipid nanoparticles (SLN) and nanostructured lipid carriers (NLC) for the delivery of bioactives sourced from plants: part II - applications and preclinical advancements.

INTRODUCTION: Numerous purified bioactive compounds, crude extracts, and essential oils have demonstrated potent antioxidant, antimicrobial, anti-inflammatory, and antiviral properties, particularly in vitro or in silico; however, their in vivo applications are hindered by inadequate absorption and distribution in the organism. The incorporation of these phytochemicals into solid lipid nanoparticles (SLN) or nanostructured lipid carriers (NLC) has demonstrated significant advancements and represents a viable approach to improve their bioavailability through different administration routes. AREAS COVERED: This review discusses the potential applications of SLN and NLC, loading bioactive compounds sourced from plants for the treatment of several diseases. An overview of the preclinical developments on the use of these lipid nanoparticles is also provided as well as the requisites to be launched on the market. EXPERT OPINION: Medicinal plants have gained even more value for the pharmaceutical industries and their customers, leading to many studies exploring their therapeutic potential. Several bioactives derived from plants with antiviral, anticancer, neuroprotective, antioxidant, and antiaging properties have been proposed and loaded into lipid nanoparticles. In vitro and invivo studies corroborate the added value of SLN/NLC to improve the bioavailability of several bioactives. Surface modification to increase their stability and target delivery should be considering.

Recent Advances in Preclinical Studies of the Theranostic Agent [64Cu]CuCl2.

64Cu is gaining recognition not only for its diagnostic capabilities in nuclear medical imaging but also for its therapeutic and theranostic potential. The simultaneous ß- and Auger emissions of 64Cu can be utilized to induce a therapeutic effect on cancerous lesions. The finding of the exceptional biodistribution characteristics of the radionuclide 64Cu, when administered as basic copper ions, has highlighted its potential therapeutic application in cancer treatment. Preclinical and clinical research on the effectiveness of [64Cu]CuCl2 as a theranostic radiopharmaceutical has commenced only in the past decade. Current clinical studies are increasingly demonstrating the high specificity and uptake of [64Cu]Cu2+ by malignant tissues during early cancer progression, indicating its potential for early cancer diagnosis across various organs. This short review aims to present the latest preclinical studies involving [64Cu]CuCl2, offering valuable insights for researchers planning new in vitro and in vivo studies to explore the theranostic potential of [64Cu]Cu2+.

Recent applications of three-dimensional bioprinting in drug discovery and development.

The ability of three-dimensional (3D) bioprinting to fabricate biomimetic organ and disease models has been recognised to be promising for drug discovery and development as 3D bioprinted models can better mimic human physiology compared to two-dimensional (2D) cultures and animal models. This is useful for target selection where disease models can be studied to understand disease pathophysiology and identify disease-linked compounds. Lead identification and preclinical studies also benefit from 3D bioprinting as 3D bioprinted models can be utilised in high-throughput screening (HTS) systems and to produce efficacy and safety data that closely resembles clinical observations. Although no published applications of 3D bioprinting in clinical trials were found, there are two clinical trials planning to evaluate the predictive ability of 3D bioprinted models by comparing human and model responses to the same chemotherapy. Overall, this review provides a comprehensive summary of the latest applications of 3D bioprinting in drug discovery and development.

The therapeutic potential of bee venom-derived Apamin and Melittin conjugates in cancer treatment: A systematic review.

The therapeutic potential of bee venom-derived peptides, particularly apamin and melittin, in cancer treatment has garnered significant attention as a promising avenue for advancing oncology. This systematic review examines preclinical studies highlighting the emerging role of these peptides in enhancing cancer therapies. Melittin and apamin, when conjugated with other therapeutic agents or formulated into novel delivery systems, have demonstrated improved efficacy in targeting tumor cells. Key findings indicate that melittin-based conjugates, such as polyethylene glycol (PEG)ylated versions, show potential in enhancing therapeutic outcomes and minimizing toxicity across various cancer models. Similarly, apamin-conjugated formulations have improved the efficacy of established anti-cancer drugs, contributing to enhanced targeting and reduced systemic toxicity. These developments underscore a growing interest in leveraging bee venom-derived peptides as adjuncts in cancer therapy. The integration of these peptides into treatment regimens offers a promising strategy to address current limitations in cancer treatment, such as drug resistance and off-target effects. However, comprehensive validation through clinical trials is essential to confirm their safety and effectiveness in human patients. This review highlights the global emergence of bee venom-derived peptides in cancer treatment, advocating for continued research and development to fully realize their therapeutic potential.

Opportunities and challenges in the therapeutic exploitation of histamine and histamine receptor pharmacology in inflammation-driven disorders.

Inflammation-driven diseases encompass a wide array of pathological conditions characterised by immune system dysregulation leading to tissue damage and dysfunction. Among the myriad of mediators involved in the regulation of inflammation, histamine has emerged as a key modulatory player. Histamine elicits its actions through four rhodopsin-like G-protein-coupled receptors (GPCRs), named chronologically in order of discovery as histamine H1, H2, H3 and H4 receptors (H1-4R). The relatively low affinity H1R and H2R play pivotal roles in mediating allergic inflammation and gastric acid secretion, respectively, whereas the high affinity H3R and H4R are primarily linked to neurotransmission and immunomodulation, respectively. Importantly, however, besides the H4R, both H1R and H2R are also crucial in driving immune responses, the H2R tending to promote yet ill-defined and unexploited suppressive, protective and/or resolving processes. The modulatory action of histamine via its receptors on inflammatory cells is described in detail. The potential therapeutic value of the most recently discovered H4R in inflammatory disorders is illustrated via a selection of preclinical models. The clinical trials with antagonists of this receptor are discussed and possible reasons for their lack of success described.

Approbation of a Homologous Model of the Antitumor Vaccine Based on Mature Mouse Dendritic Cells to Study the Biodistribution of the Cell Product.

Homologous animal cell product was obtained in protocol developed for female BALB/c mice. Dendritic cell (DC) migration from the injection site into the draining lymph nodes was evaluated. The number of DC labeled with carboxyfluorescein succinimidyl ester (CFSE) in draining lymph nodes increased from 5.3% (16 h) to 13.3% (48 h) (p=0.028) with a maximum at 72 h (15.4%, p=0.003). The immunophenotype of CFSE-DC detected in murine lymph nodes corresponded to the immunophenotype of mature vaccine DCs: they expressed differentiation markers CD11c, CD80, CD83, and CD86 (p>0.05 vs initial DC).

Protective effect of salvianolic acid B against myocardial ischemia/reperfusion injury: preclinical systematic evaluation and meta-analysis.

Background: Salvianolic acid B is the most abundant water-soluble component in the traditional Chinese medicine Danshen and can reduce myocardial ischemia-reperfusion (MI/R) injury through multiple targets and pathways. However, the role of SalB in protecting the myocardium from ischemia/reperfusion injury remains unclear. Purpose: To perform a preclinical systematic review and meta-analysis to assess the efficacy of Sal B in an animal model of myocardial infarction/reperfusion (MI/R) and to summarize the potential mechanisms of Sal B against MI/R. Methods: Studies published from inception to March 2024 were systematically searched in PubMed, Web of Science, Embase, China National Knowledge Infrastructure Wanfang, and VIP databases. The methodological quality was determined using the SYRCLE RoB tool. The R software was used to analyze the data. The potential mechanisms are categorized and summarized. Results: 32 studies containing 732 animals were included. The results of the meta-analysis showed that Sal B reduced myocardial infarct size (p < 0.01), and the cardiological indices of CK-MB (p < 0.01), CK (p < 0.01), LDH (p < 0.01), and cTnI (p < 0.01) compared to the control group. In addition, Sal B increased cardiac function indices, such as LVFS (p < 0.01), -dp/dt max (p < 0.01), +dp/dt max (p < 0.01), and cardiac output (p < 0.01). The protective effects of Sal B on the myocardium after I/R may be mediated by attenuating oxidative stress and inflammation, promoting neovascularization, regulating vascular function, and attenuating cardiac myocyte apoptosis. Publication bias was observed in all the included studies. Further studies are required to elucidate the extent of the cardioprotective effects of SalB and the safety of its use. Conclusion: To the best of our knowledge, this is the first meta-analysis of Sal B in the treatment of MI/R injury, and Sal B demonstrated a positive effect on MI/R injury through the modulation of key pathological indicators and multiple signaling pathways. Further studies are needed to elucidate the extent to which SalB exerts its cardioprotective effects and the safety of its use. Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/.

MetFinder: A Tool for Automated Quantitation of Metastatic Burden in Histological Sections From Preclinical Models.

As efforts to study the mechanisms of melanoma metastasis and novel therapeutic approaches multiply, researchers need accurate, high-throughput methods to evaluate the effects on tumor burden resulting from specific interventions. We show that automated quantification of tumor content from whole slide images is a compelling solution to assess in vivo experiments. In order to increase the outflow of data collection from preclinical studies, we assembled a large dataset with annotations and trained a deep neural network for the quantitative analysis of melanoma tumor content on histopathological sections of murine models. After assessing its performance in segmenting these images, the tool obtained consistent results with an orthogonal method (bioluminescence) of measuring metastasis in an experimental setting. This AI-based algorithm, made freely available to academic laboratories through a web-interface called MetFinder, promises to become an asset for melanoma researchers and pathologists interested in accurate, quantitative assessment of metastasis burden.

Advancing CAR T-cell therapies: Preclinical insights and clinical translation for hematological malignancies.

Chimeric antigen receptor (CAR) T-cell therapy has achieved significant success in achieving durable and potentially curative responses in patients with hematological malignancies. CARs are tailored fusion proteins that direct T cells to a specific antigen on tumor cells thereby eliciting a targeted immune response. The approval of several CD19-targeted CAR T-cell therapies has resulted in a notable surge in clinical trials involving CAR T cell therapies for hematological malignancies. Despite advancements in understanding response mechanisms, resistance patterns, and adverse events associated with CAR T-cell therapy, the translation of these insights into robust clinical efficacy has shown modest outcomes in both clinical trials and real-world scenarios. Therefore, the assessment of CAR T-cell functionality through rigorous preclinical studies plays a pivotal role in refining therapeutic strategies for clinical applications. This review provides an overview of the various in vitro and animal models used to assess the functionality of CAR T-cells. We discuss the findings from preclinical research involving approved CAR T-cell products, along with the implications derived from recent preclinical studies aiming to optimize the functionality of CAR T-cells. The review underscores the importance of robust preclinical evaluations and the need for models that accurately replicate human disease to bridge the gap between preclinical success and clinical efficacy.

Cardioprotection of Canagliflozin, Dapagliflozin, and Empagliflozin: Lessons from preclinical studies.

Clinical and preclinical studies have elucidated the favorable effects of Inhibitors of Sodium-Glucose Cotransporter-2 (iSGLT2) in patients and animal models with type 2 diabetes. Notably, these inhibitors have shown significant benefits in reducing hospitalizations and mortality among patients with heart failure. However, despite their incorporation into clinical practice for indications beyond diabetes, the decision-making process regarding their use often lacks a systematic approach. The selection of iSGLT2 remains arbitrary, with only a limited number of studies simultaneously exploring the different classes of them. Currently, no unique guideline establishes their application in both clinical and basic research. This review delves into the prevalent use of iSGLT2 in animal models previously subjected to induced cardiac stress. We have compiled key findings related to cardioprotection across various animal models, encompassing diverse dosages and routes of administration. Beyond their established role in diabetes management, iSGLT2 has demonstrated utility as agents for safeguarding heart health and cardioprotection can be class-dependent among the iSGLT2. These findings may serve as valuable references for other researchers. Preclinical studies play a pivotal role in ensuring the safety of novel compounds or treatments for potential human use. By assessing side effects, toxicity, and optimal dosages, these studies offer a robust foundation for informed decisions, identifying interventions with the highest likelihood of success and minimal risk to patients. The insights gleaned from preclinical studies, which play a crucial role in highlighting areas of knowledge deficiency, can guide the exploration of novel mechanisms and strategies involving iSGLT2.

Flavonoids as therapeutics for myocardial ischemia-reperfusion injury: a comprehensive review on preclinical studies.

Ischemic heart disease is the most prevalent cause of death worldwide affecting both the gender of all age groups. The high mortality rate is due to damage of myocardial tissue that emanates at the time of myocardial ischemia and re-oxygenation, thus averting reperfusion injury is recognized as a potential way to reduce acute cardiac injury and subsequent mortality. Flavonoids are polyphenol derivatives of plant origin and empirical shreds of evidence substantiate their numerous activities such as antioxidant, anti-inflammatory, anti-apoptotic, and anti-thrombotic activity, leading to their role in cardio protection. Recent investigations have unveiled the capacity of flavonoids to impede pivotal regulatory enzymes, signaling molecules, and transcription factors that orchestrate the mediators participating in the inflammatory cascade. The present comprehensive review, dwells on the preclinical studies on the effectiveness of flavonoids from the year 2007 to 2023, for the prevention and therapeutics for myocardial ischemia-reperfusion injury.

A systematic review of preclinical studies targeted toward the management of co-existing functional gastrointestinal disorders, stress, and gut dysbiosis.

Modern dietary habits and stressed lifestyle have escalated the tendency to develop functional gastrointestinal disorders (FGIDs) through alteration in the gut-brain-microbiome axis. Clinical practices use symptomatic treatments, neglect root causes, and prolong distress in patients. The past decade has seen the evolution of various interventions to attenuate FGIDs. But clinical translation of such studies is very rare mostly due to lack of awareness. The aim of this review is to meticulously integrate different studies and bridge this knowledge gap. Literature between 2013 and 2023 was retrieved from PubMed, ProQuest, and Web of Science. The data was extracted based on the PRISMA guidelines and using the SYRCLE's risk of bias and the Cochrane Risk of Bias tools, quality assessment was performed. The review has highlighted molecular insights into the coexistence of FGIDs, stress, and gut dysbiosis. Furthermore, novel interventions focusing on diet, probiotics, herbal formulations, and phytoconstituents were explored which mostly had a multitargeted approach for the management of the diseases. Scientific literature implied positive interactions between the interventions and the gut microbiome by increasing the relative abundance of beneficial bacteria and reducing stress-related hormones. Moreover, the interventions reduced intestinal inflammation and regulated the expression of epithelial tight junction proteins in different in vivo models. This systematic review delves deep into the preclinical interventions to manage coexisting FGIDs, stress, and gut dysbiosis. However, in most of the discussed studies, long-term risks and toxicity profile of the interventions are lacking. So, it is necessary to highlight them for improved clinical outcomes.

Addressing barriers in diffuse intrinsic pontine glioma: the transformative role of lipid nanoparticulate drug delivery.

Background and purpose: The brainstem tumour known as diffuse intrinsic pontine glioma (DIPG), also known as pontine glioma, infiltrative brainstem glioma is uncommon and virtually always affects children. A pontine glioma develops in the brainstem's most vulnerable region (the "pons"), which regulates a number of vital processes like respiration and blood pressure. It is particularly challenging to treat due to its location and how it invades healthy brain tissue. The hunt for a solution is continually advancing thanks to advances in modern medicine, but the correct approach is still elusive. With a particular focus on brain tumours that are incurable or recur, research is ongoing to discover fresh, practical approaches to target particular areas of the brain. Experimental approach: To successfully complete this task, a thorough literature search was carried out in reputable databases like Google Scholar, PubMed, and ScienceDirect. Key results: The present article provides a comprehensive analysis of the notable advantages of lipid nanoparticles compared to alternative nanoparticle formulations. The article delves into the intricate realm of diverse lipid-based nanoparticulate delivery systems, which are used in Diffuse Intrinsic Pontine Glioma (DIPG) which thoroughly examines preclinical and clinical studies, providing a comprehensive analysis of the effectiveness and potential of lipid nanoparticles in driving therapeutic advancements for DIPG. Conclusion: There is strong clinical data to support the promising method of using lipid-based nanoparticulate drug delivery for brain cancer treatment, which shows improved outcomes.

The Emerging Field of Viroimmunotherapy for Pediatric Brain Tumors.

Pediatric brain tumors are the most common solid tumors in children. Even to date, with the advances in multimodality therapeutic management, survival outcomes remain dismal in some types of tumors, such as pediatric-type diffuse high-grade gliomas or central nervous system (CNS) embryonal tumors. Failure to understand the complex molecular heterogeneity and the elusive tumor and microenvironment interplay continues to undermine therapeutic efficacy. Developing a strategy that would improve survival for these fatal tumors remains unmet in pediatric neuro-oncology. Oncolytic viruses (OVs) are emerging as a feasible, safe, and promising therapy for brain tumors. The new paradigm in virotherapy implies that the direct cytopathic effect is followed, under certain circumstances, by an antitumor immune response responsible for the partial or complete debulking of the tumor mass. OVs alone or combined with other therapeutic modalities have been primarily used in adult neuro-oncology. A surge in encouraging preclinical studies in pediatric brain tumor models recently led to the clinical translation of OVs with encouraging results in these tumors. In this review, we summarize the different virotherapy tested in preclinical and clinical studies in pediatric brain tumors, and we discuss the limitations and future avenues necessary to improve the response of these tumors to this type of therapy.

Preclinical evaluation of [18F]SYN1 and [18F]SYN2, novel radiotracers for PET myocardial perfusion imaging.

BACKGROUND: Positron emission tomography (PET) is now an established diagnostic method for myocardial perfusion imaging (MPI) in coronary artery disease, which is the main cause of death globally. The available tracers show several limitations, therefore, the 18F-labelled tracer is in high demand nowadays. The preclinical studies on normal Wistar rats aimed to characterise two potential, novel radiotracers, [18F]SYN1 and [18F]SYN2, to evaluate which is a better candidate for PET MPI cardiotracer. RESULTS: The dynamic microPET images showed rapid myocardial uptake for both tracers. However, the uptake was higher and also stable for [18F]SYN2, with an average standardized uptake value of 3.8. The biodistribution studies confirmed that [18F]SYN2 uptake in the cardiac muscle was high and stable (3.02%ID/g at 15 min and 2.79%ID/g at 6 h) compared to [18F]SYN1 (1.84%ID/g at 15 min and 0.32%ID/g at 6 h). The critical organs determined in dosimetry studies were the small intestine and the kidneys. The estimated effective dose for humans was 0.00714 mSv/MBq for [18F]SYN1 and 0.0109 mSv/MBq for [18F]SYN2. The tested dose level of 2 mg/kg was considered to be the No Observed Adverse Effect Level (NOAEL) for both candidates. The better results were achieved for [18F]SYN2, therefore, further preclinical studies were conducted only for this tracer. Radioligand binding assays showed significant responses in 3 from 68 assays: muscarinic acetylcholine M1 and M2 receptors and potassium channel hERG. The compound was mostly metabolised via an oxidative N-dealkylation, while the fluor substituent was not separated from the molecule. CONCLUSION: [18F]SYN2 showed a favourable pharmacodynamic and pharmacokinetic profile, which enabled a clear visualization of the heart in microPET. The compound was well-tolerated in studies in normal rats with moderate radiation exposure. The results encourage further exploration of [18F]SYN2 in clinical studies.

From bench to bedside: the application of cannabidiol in glioma.

Glioma is the most common malignant tumor in central nervous system, with significant health burdens to patients. Due to the intrinsic characteristics of glioma and the lack of breakthroughs in treatment modalities, the prognosis for most patients remains poor. This results in a heavy psychological and financial load worldwide. In recent years, cannabidiol (CBD) has garnered widespread attention and research due to its anti-tumoral, anti-inflammatory, and neuroprotective properties. This review comprehensively summarizes the preclinical and clinical research on the use of CBD in glioma therapy, as well as the current status of nanomedicine formulations of CBD, and discusses the potential and challenges of CBD in glioma therapy in the future.

Trace amine-associated receptor 1 (TAAR1) agonism for psychosis: a living systematic review and meta-analysis of human and non-human data.

Background: Trace amine-associated receptor 1 (TAAR1) agonism shows promise for treating psychosis, prompting us to synthesise data from human and non-human studies. Methods: We co-produced a living systematic review of controlled studies examining TAAR1 agonists in individuals (with or without psychosis/schizophrenia) and relevant animal models. Two independent reviewers identified studies in multiple electronic databases (until 17.11.2023), extracted data, and assessed risk of bias. Primary outcomes were standardised mean differences (SMD) for overall symptoms in human studies and hyperlocomotion in animal models. We also examined adverse events and neurotransmitter signalling. We synthesised data with random-effects meta-analyses. Results: Nine randomised trials provided data for two TAAR1 agonists (ulotaront and ralmitaront), and 15 animal studies for 10 TAAR1 agonists. Ulotaront and ralmitaront demonstrated few differences compared to placebo in improving overall symptoms in adults with acute schizophrenia (N=4 studies, n=1291 participants; SMD=0.15, 95%CI: -0.05, 0.34), and ralmitaront was less efficacious than risperidone (N=1, n=156, SMD=-0.53, 95%CI: -0.86, -0.20). Large placebo response was observed in ulotaront phase-III trials. Limited evidence suggested a relatively benign side-effect profile for TAAR1 agonists, although nausea and sedation were common after a single dose of ulotaront. In animal studies, TAAR1 agonists improved hyperlocomotion compared to control (N=13 studies, k=41 experiments, SMD=1.01, 95%CI: 0.74, 1.27), but seemed less efficacious compared to dopamine D 2 receptor antagonists (N=4, k=7, SMD=-0.62, 95%CI: -1.32, 0.08). Limited human and animal data indicated that TAAR1 agonists may regulate presynaptic dopaminergic signalling. Conclusions: TAAR1 agonists may be less efficacious than dopamine D 2 receptor antagonists already licensed for schizophrenia. The results are preliminary due to the limited number of drugs examined, lack of longer-term data, publication bias, and assay sensitivity concerns in trials associated with large placebo response. Considering their unique mechanism of action, relatively benign side-effect profile and ongoing drug development, further research is warranted. Registration: PROSPERO-ID: CRD42023451628.

There is a need for more effective treatments for psychosis, including schizophrenia. Psychosis is a collection of mental health symptoms, such as hearing voices, that can cause distress and impair functioning. These symptoms are thought to be caused by changes in a chemical messenger system in the brain called dopamine. Currently used antipsychotic medications target brain receptors that respond to dopamine. They are not effective in some people and can cause uncomfortable adverse events, such as weight gain and movement disorders, especially with long-term use. A new type of drug is the trace amine-associated receptor 1 (TAAR1) agonists. These drugs act on different brain receptors that can affect the activity of the dopamine system, but do not directly bind to dopamine receptors. We aimed to understand if TAAR1 agonists can reduce symptoms of psychosis, what adverse events they might have, and how they work. We did this by reviewing and collating all available evidence until November 2023. This is a "living" systematic review, so it will be regularly updated in the future. We looked at both human and animal studies investigating TAAR1 agonists. Human studies suggested that two TAAR1 agonists (namely, ulotaront or ralmitaront) might have little to no effect on reducing symptoms of psychosis compared to placebo in people with schizophrenia. They seemed to cause fewer adverse events than current antipsychotics. Data from animal studies suggested that TAAR1 agonists had some positive effects but potentially smaller than other antipsychotics. There were little to no data from both human and animal studies about how TAAR1 agonists actually work. From the current evidence we are uncertain about these results. With the ongoing development of new TAAR1 agonists, more evidence is needed to understand their potential role in the treatment of psychosis.

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. These modifications include gene supplementation, correction, or silencing, offering a wide range of therapeutic possibilities. Moving forward, we anticipate witnessing the unfolding therapeutic potential of these strategies in the coming years. The aim of our review is to summarize preclinical data on gene editing in animal models of inherited liver diseases and the clinical data obtained thus far, emphasizing both therapeutic efficacy and potential limitations of these medical interventions.

Calorie restriction in mice impairs cortical but not trabecular peak bone mass by suppressing bone remodeling.

Calorie restriction (CR) can lead to weight loss and decreased substrate availability for bone cells. Ultimately, this can lead to impaired peak bone acquisition in children and adolescence and bone loss in adults. But the mechanisms that drive diet-induced bone loss in humans are not well characterized. To explore those in greater detail, we examined the impact of 30% CR for 4 and 8 wk in both male and female 8-wk-old C57BL/6 J mice. Body composition, areal bone mineral density (aBMD), skeletal microarchitecture by micro-CT, histomorphometric parameters, and in vitro trajectories of osteoblast and adipocyte differentiation were examined. After 8 wk, CR mice lost weight and exhibited lower femoral and whole-body aBMD vs ad libitum (AL) mice. By micro-CT, CR mice had lower cortical bone area fraction vs AL mice, but males had preserved trabecular bone parameters and females showed increased bone volume fraction compared to AL mice. Histomorphometric analysis revealed that CR mice had a profound suppression in trabecular as well as endocortical and periosteal bone formation in addition to reduced bone resorption compared to AL mice. Bone marrow adipose tissue was significantly increased in CR mice. In vitro, the pace of adipogenesis in bone marrow stem cells was greatly accelerated with higher markers of adipocyte differentiation and more oil red O staining, whereas osteogenic differentiation was reduced. qRT-PCR and western blotting suggested that the expression of Wnt16 and the canonical ß-catenin pathway was compromised during CR. In sum, CR causes impaired peak cortical bone mass due to a profound suppression in bone remodeling. The increase in marrow adipocytes in vitro and in vivo is related to both progenitor recruitment and adipogenesis in the face of nutrient insufficiency. Long-term CR may lead to lower bone mass principally in the cortical envelope, possibly due to impaired Wnt signaling.

Calorie restriction led to impaired bone mass and increased accumulation of bone marrow adipose tissue. During the development of bone-fat imbalance due to calorie restriction, bone remodeling was notably inhibited. Calorie restriction may shift the differentiation of bone marrow stem cells toward adipocytes instead of osteoblasts. This process involves a disruption in the canonical Wnt signaling pathway.