Preclinical Animal Models Research Articles

Intravital Two-Photon Microscopy of the Transplanted Mouse Lung.

Complications after lung transplantation are largely related to the host immune system responding to the graft. Such immune responses are regulated by crosstalk between donor and recipient cells. A better understanding of these processes relies on the use of preclinical animal models and is aided by an ability to study intra-graft immune cell trafficking in real-time. Intravital two-photon microscopy can be used to image tissues and organs for depths up to several hundred microns with minimal photodamage, which affords a great advantage over single-photon confocal microscopy. Selective use of transgenic mice with promoter-specific fluorescent protein expression and/or adoptive transfer of fluorescent dye-labeled cells during intravital two-photon microscopy allows for the dynamic study of single cells within their physiologic environment. Our group has developed a technique to stabilize mouse lungs, which has enabled us to image cellular dynamics in naïve lungs and orthotopically transplanted pulmonary grafts. This technique allows for detailed assessment of cellular behavior within the vasculature and in the interstitium, as well as for examination of interactions between various cell populations. This procedure can be readily learned and adapted to study immune mechanisms that regulate inflammatory and tolerogenic responses after lung transplantation. It can also be expanded to the study of other pathogenic pulmonary conditions.

Testing of putative antiseizure medications in a preclinical Dravet syndrome zebrafish model.

Dravet syndrome is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications. Preclinical Dravet syndrome animal models are a valuable tool to identify candidate anti-seizure medications for these patients. Among these, scn1lab mutant zebrafish, exhibiting spontaneous seizure-like activity, are particularly amenable to large-scale drug screening. Thus far, we have screened more than 3000 drug candidates in scn1lab zebrafish mutants, identifying valproate, stiripentol, and fenfluramine e.g. Food and Drug Administration-approved drugs, with clinical application in the Dravet syndrome population. Successful phenotypic screening in scn1lab mutant zebrafish is rigorous and consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behaviour and (ii) an electrophysiology-based assay, using in vivo local field potential recordings, to quantify electrographic seizure-like events. Historically, nearly 90% of drug candidates fail during translation from preclinical models to the clinic. With such a high failure rate, it becomes necessary to address issues of replication and false positive identification. Leveraging our scn1lab zebrafish assays is one approach to address these problems. Here, we curated a list of nine anti-seizure drug candidates recently identified by other groups using preclinical Dravet syndrome models: 1-Ethyl-2-benzimidazolinone, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-Ethyl-2-benzimidazolinone, chlorzoxazone and lisuride. However, second-stage local field potential recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of anti-seizure medications.

Current Perspectives and Progress in Preoperative Portal Vein Embolization with Stem Cell Augmentation (PVESA).

Portal vein embolization with stem cell augmentation (PVESA) is an emerging approach for enhancing the growth of the liver segment that will remain after surgery (i.e., future liver remnant, FLR) in patients with liver cancer. Conventional portal vein embolization (PVE) aims to induce preoperative FLR growth, but it has a risk of failure in patients with underlying liver dysfunction and comorbid illnesses. PVESA combines PVE with stem cell therapy to potentially improve FLR size and function more effectively and efficiently. Various types of stem cells can help improve liver growth by secreting paracrine signals for hepatocyte growth or by transforming into hepatocytes. Mesenchymal stem cells (MSCs), unrestricted somatic stem cells, and small hepatocyte-like progenitor cells have been used to augment liver growth in preclinical animal models, while clinical studies have demonstrated the benefit of CD133 + bone marrow-derived MSCs and hematopoietic stem cells. These investigations have shown that PVESA is generally safe and enhances liver growth after PVE. However, optimizing the selection, collection, and application of stem cells remains crucial to maximize benefits and minimize risks. Additionally, advanced stem cell technologies, such as priming, genetic modification, and extracellular vesicle-based therapy, that could further enhance efficacy outcomes should be evaluated. Despite its potential, PVESA requires more investigations, particularly mechanistic studies that involve orthotopic animal models of liver cancer with concomitant liver injury as well as larger human trials.

Cerebrovascular dysfunction and depressive symptoms in preclinical models: insights from a scoping review.

Although existing literature supports associations between cerebrovascular dysfunction and the emergence of depression and depressive symptoms, relatively little is known about underlying mechanistic pathways that may explain potential relationships. As such, an integrated understanding of these relationships in preclinical models could provide insight into the nature of the relationship, basic mechanistic linkages, and areas in which additional investment should be targeted. This scoping review was conducted in MEDLINE, EMBASE, and Scopus to outline the relationship between depressive symptoms and cerebrovascular dysfunction in preclinical animal models with an additional focus on the areas above. From 3,438 articles initially identified, 15 studies met the inclusion criteria and were included in the review. All studies reported a positive association between the severity of markers for cerebrovascular dysfunction and that for depressive symptoms in rodent models and this spanned all models for either pathology. Specific mechanistic links between the two such as chronic inflammation, elevated vascular oxidant stress, and altered serotonergic signaling were highlighted. Notably, almost all studies addressed outcomes in male animals, with a near complete lack of data from females, and there was little consistency in terms of how cerebrovascular dysfunction was assessed. Across nearly all studies was a lack of clarity for any "cause and effect" relationship between depressive symptoms and cerebrovascular dysfunction. At this time, it is reasonable to conclude that a correlative relationship clearly exists between the two, and future investigation will be required to parse out more specific aspects of this relationship.NEW & NOTEWORTHY This scoping review presents a structured evaluation of all relevant existing literature linking cerebral vasculopathy to depressive symptom emergence in preclinical models. Results support a definite connection between vascular dysfunction and depressive symptoms, highlighting the importance of chronic elevations in inflammation and oxidant stress, and impaired serotonergic signaling. The review also identified significant knowledge gaps addressing male versus female differences and limited clear mechanistic links between cerebral vasculopathy and depressive symptoms.

Head Injury Treatment With Healthy and Advanced Dietary Supplements: A Pilot Randomized Controlled Trial of the Tolerability, Safety, and Efficacy of Branched Chain Amino Acids in the Treatment of Concussion in Adolescents and Young Adults.

Concussion is a common injury in the adolescent and young adult populations. Although branched chain amino acid (BCAA) supplementation has shown improvements in neurocognitive and sleep function in pre-clinical animal models of mild-to-moderate traumatic brain injury (TBI), to date, no studies have been performed evaluating the efficacy of BCAAs in concussed adolescents and young adults. The goal of this pilot trial was to determine the efficacy, tolerability, and safety of varied doses of oral BCAA supplementation in a group of concussed adolescents and young adults. The study was conducted as a pilot, double-blind, randomized controlled trial of participants ages 11-34 presenting with concussion to outpatient clinics (sports medicine and primary care), urgent care, and emergency departments of a tertiary care pediatric children's hospital and an urban tertiary care adult hospital, between June 24, 2014 and December 5, 2020. Participants were randomized to one of five study arms (placebo and 15 g, 30 g, 45 g, and 54 g BCAA treatment daily) and followed for 21 days after enrollment. Outcome measures included daily computerized neurocognitive tests (processing speed, the a priori primary outcome; and attention, visual learning, and working memory), symptom score, physical and cognitive activity, sleep/wake alterations, treatment compliance, and adverse events. In total, 42 participants were randomized, 38 of whom provided analyzable data. We found no difference in our primary outcome of processing speed between the arms; however, there was a significant reduction in total symptom score (decrease of 4.4 points on a 0-54 scale for every 500 g of study drug consumed, p value for trend = 0.0036, [uncorrected]) and return to physical activity (increase of 0.503 points on a 0-5 scale for every 500 g of study drug consumed, p value for trend = 0.005 [uncorrected]). There were no serious adverse events. Eight of 38 participants reported a mild (not interfering with daily activity) or moderate (limitation of daily activity) adverse event; there were no differences in adverse events by arm, with only two reported mild adverse events (both gastrointestinal) in the highest (45 g and 54 g) BCAA arms. Although limited by slow enrollment, small sample size, and missing data, this study provides the first demonstration of efficacy, as well as safety and tolerability, of BCAAs in concussed adolescents and young adults; specifically, a dose-response effect in reducing concussion symptoms and a return to baseline physical activity in those treated with higher total doses of BCAAs. These findings provide important preliminary data to inform a larger trial of BCAA therapy to expedite concussion recovery.

Local, Quantitative Morphometry of Fibroproliferative Lung Injury Using Laminin.

Investigations into the mechanisms of injury and repair in fibroproliferative disease require consideration of the spatial heterogeneity inherent in the disease. Most scoring of fibrotic remodeling in preclinical animal models relies on the modified Ashcroft score, which is an ordinal rubric of macroscopic resolution. The obvious limitations of manual histopathologic scoring have generated an unmet need for unbiased, repeatable scoring of fibroproliferative burden in tissue. Using computer vision approaches on immunofluorescence imaging of the extracellular matrix component laminin, we generated a robust and repeatable quantitative remodeling scorer. In the bleomycin lung injury model, the quantitative remodeling scorer shows significant agreement with the modified Ashcroft scale. This antibody-based approach is easily integrated into larger multiplex immunofluorescence experiments, which we demonstrate by testing the spatial apposition of tertiary lymphoid structures to fibroproliferative tissue, a poorly characterized phenomenon observed in both human interstitial lung diseases and preclinical models of lung fibrosis. The tool reported in this article is available as a stand-alone application that is usable without programming knowledge.

Abstract ND02: Discovery of BMS-986365, a ligand-directed androgen receptor degrader (AR LDD) with a dual mechanism-of-action and best-in-class potential, for the treatment of advanced prostate cancer

Abstract The androgen receptor (AR) is a key driver of the cellular processes that contribute to the pathology of prostate cancers at most stages, and drugs that inhibit the activity of this receptor or interfere with androgen biosynthesis have become the cornerstone of treatments for prostate cancer. While both types of therapy have had a significant positive impact on disease progression and overall survival, de novo and acquired resistance remains an impediment to a durable clinical response in patients with metastatic castration-resistant prostate cancer (mCRPC). The mechanisms underlying drug resistance are complex and multifactorial, being attributable to AR overexpression, point mutations in the receptor that alter drug pharmacology, and to the upregulation of receptor-associated coregulators, which render AR less dependent on an activating ligand. Regardless, absolute inhibition of AR signaling remains the objective of contemporary approaches to treat prostate cancer. Recently, there has been specific interest in the development of approaches to eliminate AR proteins using drugs that enable targeted degradation of AR in cancer cells.This puts in context the significance of our discovery of BMS-986365 (also known as CC-94676), a heterobifunctional ligand-directed degrader (LDD) that enables the CRL4CRBN E3 ligase-dependent ubiquitination and degradation of AR (DC50 10 to 40 nM, Ymin 7 to 19%). BMS-986365 is a highly potent and selective AR degrader that induces rapid and deep degradation of both wildtype and mutant forms of the receptor residing in either the cytoplasmic or nuclear compartments of the cell. The drug is ~100-fold more potent than enzalutamide (ENZ) at inhibiting androgen-stimulated transcription of AR target genes, and 10 to 120-fold more potent than ENZ at inhibiting AR-dependent proliferation of multiple prostate cancer cell lines in vitro. In animal models of advanced prostate cancer, BMS-986365 demonstrates on-target activity, degrading AR, suppressing AR signaling, and inhibiting tumor growth. Indeed, tumor volume reductions of 63-92% were achieved by BMS-986365 in validated models of advanced CRPC and therapy resistant patient-derived xenografts, including those with acquired resistance to ENZ. Collectively our preclinical data suggest that the AR degrader BMS-986365 is superior to standard-of-care AR antagonists, such as ENZ, in both preclinical and disease-relevant animal models, and support its clinical development for treatment of prostate cancer. BMS-986365 has advanced into clinical studies where it has demonstrated encouraging clinical activity in patients with mCRPC. Citation Format: Shuichan Xu, Surendra Nayak, John D. Norris, Massimo Ammirante, Emyly Rychak, Suzanne E. Wardell, Toshiya Tsuji, Ken Liu, Joseph Meiring, Joseph R. Piccotti, Deepak Dalvie, Debbie Liao, Raju Kandimalla, Nadia Guerrero, Lisa Sapinoso, Jennifer G. Baker, Yeeun Bae, Joshua Baughman, Brandon Toyama, Celia Fontanillo Fontanillo, Stephen Norris, Evan J. Horn, Veronique Plantevin-Krenitsky, Deborah Mortensen, Brian Cathers, Marie Hong Nguyen, Joshua D. Hensen, Lawrence G. Hamann, Donald P. McDonnell, Rama Krishna Narla, Mark Rolfe. Discovery of BMS-986365, a ligand-directed androgen receptor degrader (AR LDD) with a dual mechanism-of-action and best-in-class potential, for the treatment of advanced prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr ND02.

Unlocking the Future: Pluripotent Stem Cell-Based Lung Repair.

The human respiratory system is susceptible to a variety of diseases, ranging from chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis to acute respiratory distress syndrome (ARDS). Today, lung diseases represent one of the major challenges to the health care sector and represent one of the leading causes of death worldwide. Current treatment options often focus on managing symptoms rather than addressing the underlying cause of the disease. The limitations of conventional therapies highlight the urgent clinical need for innovative solutions capable of repairing damaged lung tissue at a fundamental level. Pluripotent stem cell technologies have now reached clinical maturity and hold immense potential to revolutionize the landscape of lung repair and regenerative medicine. Meanwhile, human embryonic (HESCs) and human-induced pluripotent stem cells (hiPSCs) can be coaxed to differentiate into lung-specific cell types such as bronchial and alveolar epithelial cells, or pulmonary endothelial cells. This holds the promise of regenerating damaged lung tissue and restoring normal respiratory function. While methods for targeted genetic engineering of hPSCs and lung cell differentiation have substantially advanced, the required GMP-grade clinical-scale production technologies as well as the development of suitable preclinical animal models and cell application strategies are less advanced. This review provides an overview of current perspectives on PSC-based therapies for lung repair, explores key advances, and envisions future directions in this dynamic field.

Abstract LB364: Generation and Application of a Robust Humanized Mouse Tumor Model System for Evaluation of NK-Targeting Therapeutics

Abstract With the new waves of anti-tumor immunotherapy development, novel immunotherapies based on NK cells have emerged and advanced rapidly. Considering the inherent mechanisms of NK cells, various strategies are employed in tumor immunotherapy to maximize the efficacy of NK cells, including the following: 1) immune checkpoint inhibitors to relieve NK cell inhibition signals; 2) activation of NK cell activity; 3) targeted antibody therapy for tumor cell killing via antibody-dependent cellular cytotoxicity (ADCC), and 4) cell therapy, such as CAR-NK. Although numerous NK-targeting immune therapeutics or various NK-modulating modalities have been developed or advanced toward clinical trials, there is a lack of clinically relevant preclinical animal models that can be widely accepted for the evaluation of NK-modulating agents, particularly for models that involve functional human NK cells in the test system. This study generated a humanized mouse tumor model system which involves specific reconstitution of functional and durable human NK cells in a murine system, providing a clinically relevant tumor microenvironment. We first engineered a stable monoclonal feeder cell line in vitro to expand NK cells isolated from human peripheral blood mononuclear cells (hPBMCs) using magnetic bead separation. Using this approach, the human primary NK cells were robustly and consistently amplified (up to hundreds of fold) while maintaining their purity and functionality. When compared with primary NK cells using in vitro immune assays including ADCC and FACs, the expanded NK cells showed comparable results as the parental cells. In vivo experimental results indicated that a durable and functional NK reconstitution can be established in tumor-bearing severely immune deficient mice expressing hIL-15. Furthermore, this NK-humanized tumor model system was proven to respond to standard of care (SOC) NK-targeting drugs. In summary, this novel NK humanized in vivo model may represent an effective preclinical tool for assessing NK-modulating drugs, with the hope of facilitating the development process of novel immune therapeutics employing both adaptive and innate immunity. Citation Format: Feng Lu, Weiqun Ding, Guangliang Yang, Yaoqing Jia, Zhaoxiang Wang, Xusheng Yuan, Ming Yin, Zhijian Yang, WenQing Yang. Generation and Application of a Robust Humanized Mouse Tumor Model System for Evaluation of NK-Targeting Therapeutics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB364.

Intrasynovial autograft for reconstruction of chronic large rotator cuff tears in a rabbit model: biomechanical, computed tomography, and histological results

BackgroundRotator cuff (RC) tears are a common cause of shoulder dysfunction and pain, posing significant challenges for orthopedic surgeons. Grafts have been proposed as a solution to augment or bridge torn tendons, but optimal clinical outcomes are not always achieved due to poor graft integration, suboptimal mechanical properties, and immunological reactions. The aim of this study was to investigate the biomechanical, CT and histological results of RC reconstruction using an intrasynovial tendon autograft, in a chronic large tear subscapularis rabbit model.MethodsTwenty-six adult male Zealand white rabbits were used in this study. Large defects in the subscapularis tendons were produced bilaterally in 20 rabbits. After 6 weeks, secondary procedures were performed to the right shoulder of the rabbits, which were reconstructed with an intrasynovial interposition autograft (graft group). The left shoulder did not undergo any further treatment (defect group). The specimens were randomly divided into two equal time groups and underwent biomechanical testing, CT analysis, and histological evaluation at 6, and 12 weeks after reconstruction. In addition, 6 rabbits that were not operated, were used as a control group.ResultsAt 12 weeks post-repair, the graft group exhibited a significant increase in ultimate failure load compared to the defect group (p < 0.05). Furthermore, the 12-week graft group demonstrated comparable stiffness to that of the control group. CT analysis indicated no significant progression of intramuscular fat accumulation in both graft groups, in contrast to the 12-week defect group when compared to the control group. Finally, histological evaluation revealed a gradual integration of the graft with the host tissue at 12 weeks.ConclusionOur study suggests that intrasynovial flexor tendon autografts hold promise as an effective interposition graft for the reconstruction of chronic large RC tears, as they improve the biomechanical and biological properties of the repaired tendon. Nonetheless, further investigations in preclinical large animal models are warranted to validate and extrapolate these findings to human studies.

Orthotopic transplantation of the bioengineered lung using a mouse-scale perfusion-based bioreactor and human primary endothelial cells

Whole lung engineering and the transplantation of its products is an ambitious goal and ultimately a viable solution for alleviating the donor-shortage crisis for lung transplants. There are several limitations currently impeding progress in the field with a major obstacle being efficient revascularization of decellularized scaffolds, which requires an extremely large number of cells when using larger pre-clinical animal models. Here, we developed a simple but effective experimental pulmonary bioengineering platform by utilizing the lung as a scaffold. Revascularization of pulmonary vasculature using human umbilical cord vein endothelial cells was feasible using a novel in-house developed perfusion-based bioreactor. The endothelial lumens formed in the peripheral alveolar area were confirmed using a transmission electron microscope. The quality of engineered lung vasculature was evaluated using box-counting analysis of histological images. The engineered mouse lungs were successfully transplanted into the orthotopic thoracic cavity. The engineered vasculature in the lung scaffold showed blood perfusion after transplantation without significant hemorrhage. The mouse-based lung bioengineering system can be utilized as an efficient ex-vivo screening platform for lung tissue engineering.

The case for neuregulin-1 as a clinical treatment for stroke.

Ischemic stroke is the leading cause of serious long-term disability and the 5th leading cause of death in the United States. Revascularization of the occluded cerebral artery, either by thrombolysis or endovascular thrombectomy, is the only effective, clinically-approved stroke therapy. Several potentially neuroprotective agents, including glutamate antagonists, anti-inflammatory compounds and free radical scavenging agents were shown to be effective neuroprotectants in preclinical animal models of brain ischemia. However, these compounds did not demonstrate efficacy in clinical trials with human patients following stroke. Proposed reasons for the translational failure include an insufficient understanding on the cellular and molecular pathophysiology of ischemic stroke, lack of alignment between preclinical and clinical studies and inappropriate design of clinical trials based on the preclinical findings. Therefore, novel neuroprotective treatments must be developed based on a clearer understanding of the complex spatiotemporal mechanisms of ischemic stroke and with proper clinical trial design based on the preclinical findings from specific animal models of stroke. We and others have demonstrated the clinical potential for neuregulin-1 (NRG-1) in preclinical stroke studies. NRG-1 significantly reduced ischemia-induced neuronal death, neuroinflammation and oxidative stress in rodent stroke models with a therapeutic window of >13 h. Clinically, NRG-1 was shown to be safe in human patients and improved cardiac function in multisite phase II studies for heart failure. This review summarizes previous stroke clinical candidates and provides evidence that NRG-1 represents a novel, safe, neuroprotective strategy that has potential therapeutic value in treating individuals after acute ischemic stroke.

Subjective discomfort and lack of volitional drive with neuroleptic pharmacotherapy - a phenomenological case study

IntroductionIn comparison to extrapyramidal and metabolic side effects, the subjective aspects of neuroleptic treatment have been less extensively researched. Nevertheless, they are equally significant given their potential to influence adherence and functional outcome. Historically, terms such as “neuroleptic dysphoria,” “neuroleptic-induced psychic indifference,” and “neuroleptic-induced deficit syndrome” were used to characterize a range of unpleasant mood states on the one hand and a documented and observable motivational deficit on the other. The latter aligns with the findings from preclinical neuroscientific studies and animal models highlighting the significant involvement of mesolimbic dopamine in motivational processes. Despite an abundance of anecdotal data these adverse effects are often undetectable in large-scale clinical studies that utilize standardized assessment measures.ObjectivesTo present adverse subjective changes in arousal, mood and volitional drive resulting from neuroleptic intake from a patient’s perspective.MethodsThe subject is a patient, with no reported negative symptoms or lasting functional impairment described, who underwent a gradual 6-month discontinuation of risperidone in an outpatient setting following a complete recovery after a single psychotic episode. A semi-structured interview modelled after The Clinical Assessment Interview for Negative Symptoms (CAINS) was conducted. We aimed to elicit descriptions of the subjective experience while ensuring our approach remained non-suggestive.ResultsIn addition to describing potential akathisia and lethargy at higher doses, the subject reported a significant lack of motivation and a notably reduced willingness to exert effort towards achieving specific goals or engaging in activities that he still found rewarding or pleasurable. Furthermore, he consistently noted gradual improvements across various psycho-social aspects following the discontinuation of the medication. These adverse and unpleasant experiences were presented as the primary reason for wanting to discontinue pharmacological treatment.ConclusionsCertain adverse effects of antipsychotic medications can only be elucidated by the clinician through the examination of the patient’s subjective experiences. Medication induced dysphoria and volitional deficits have the potential to profoundly impact treatment adherence, leading to unrecommended discontinuation of neuroleptics, and can cause important functional impairment.Disclosure of InterestNone Declared

Pigs: Large Animal Preclinical Cancer Models.

Pigs are playing an increasingly vital role as translational biomedical models for studying human pathophysiology. The annotation of the pig genome was a huge step forward in translatability of pigs as a biomedical model for various human diseases. Similarities between humans and pigs in terms of anatomy, physiology, genetics, and immunology have allowed pigs to become a comprehensive preclinical model for human diseases. With a diverse range, from craniofacial and ophthalmology to reproduction, wound healing, musculoskeletal, and cancer, pigs have provided a seminal understanding of human pathophysiology. This review focuses on the current research using pigs as preclinical models for cancer research and highlights the strengths and opportunities for studying various human cancers.

Differential susceptibility of Onchocerca ochengi adult male worms to flubendazole in gerbils and hamsters.

Onchocerciasis is a devastating skin and eye disease that afflicts about 21 million people, most of whom live in sub-Saharan Africa. Its control with the microfilaricidal drug ivermectin is limited, thus necessitating the development of preclinical animal models to aid in the discovery of a macrofilaricide. Previously, we found that Onchocerca ochengi (the closest relative of the human O. volvulus) worm masses survive better in hamsters than in gerbils. The aim of this study was to compare the survival of O. ochengi adult male worms and their susceptibility to flubendazole (FBZ, a macrofilaricide) in gerbils and hamsters. The animals were intraperitoneally implanted with O. ochengi male worms, treated with FBZ, and sacrificed 35days post-implantation. Unlike gerbils which had some worms moving freely in the peritoneum and some in newly formed nodules (neo-nodules), all the worms in the hamsters were found in neo-nodules. FBZ significantly decreased worm burden, motility, and viability in gerbils whereas it had no significant effect in hamsters. These results highlight a major difference in how O. ochengi adult male worms are sustained and affected by FBZ in gerbils compared to hamsters. Understanding the difference between these two models is important in the development of effective macrofilaricides for onchocerciasis.

Development and Implementation of an Integrated Preclinical Atherosclerosis Database.

Basic scientists have used preclinical animal models to explore mechanisms driving human diseases for decades, resulting in thousands of publications, each supporting causative inferences. Despite substantial advances in the mechanistic construct of disease, there has been limited translation from individual studies to advances in clinical care. An integrated approach to these individual studies has the potential to improve translational success. Using atherosclerosis as a test case, we extracted data from the 2 most common mouse models of atherosclerosis (ApoE [apolipoprotein E]-knockout and LDLR [low-density lipoprotein receptor]-knockout). We restricted analyses to manuscripts published in 2 well-established journals, Arteriosclerosis, Thrombosis, and Vascular Biology and Circulation, as of query in 2021. Predefined variables including experimental conditions, intervention, and outcomes were extracted from each publication to produce a preclinical atherosclerosis database. Extracted data include animal sex, diet, intervention type, and distinct plaque pathologies (size, inflammation, and lipid content). Procedures are provided to standardize data extraction, attribute interventions to specific genes, and transform the database for use with available transcriptomics software. The database integrates hundreds of genes, each directly tested in vivo for causation in a murine atherosclerosis model. The database is provided to allow the research community to perform integrated analyses that reflect the global impact of decades of atherosclerosis investigation. This database is provided as a resource for future interrogation of sub-data sets associated with distinct plaque pathologies, cell type, or sex. We also provide the methods and software needed to expand this data set and apply this approach to the extensive repository of peer-reviewed data utilizing preclinical models to interrogate mechanisms of diverse human diseases.

Clinical potential of deciduous teeth-derived dental pulp-derived stem cell therapy for tissue regeneration

Dental pulp stem cells are mesenchymal stem cells derived from the dental pulp tissue of permanent or deciduous teeth. Especially, stem cells from human exfoliated deciduous teeth (SHED) have an enhanced capacity than adult pulp stem cells counterpartfor self-renewal (proliferation) and multilineage differentiation, being able to generate dentin/pulp-like complexes, neural cells, skin cells, chondrocytes, and osteogenic cells, among others. Their accessibility from routine dental procedures and lack of ethical concerns make SHED an attractive stem cell source for regenerative therapy. This paper reviews current preclinical and clinical research on the tissue regenerative potential of SHED-based therapies. In preclinical animal models and clinical trials, SHED transplantation have shown promise for bone regeneration and repair, neural regeneration, myocardial infarction treatment, inflam-matory bowel disease, renal injury, liver fibrosis, diabetes mellitus, erectile dysfunction, skin wounds, muscle injury, and other con-ditions. Early-phase human trials further indicate the feasibility, safety, and efficacy of SHED based cell therapy for various disease introduced before. However, therapeutic effects from SHED injections vary greatly depending on cell source, delivery method, dose, and disease model or condition. Additional translational medicine studies for elucidating key therapeutic mechanisms of SHED and methodological advances in cell processing and delivery are needed to improve consistency. If the remaining challenges are addressed through rigorous research, SHED cell therapy may become versatile clinical (dental) materials for tissue repair andregeneration across a wide range of organs and disease states.

Synthetic Cathinones: Epidemiology, Toxicity, Potential for Abuse, and Current Public Health Perspective.

Synthetic cathinones, derived from cathinone found in the plant Catha edulis, represent the second largest and most frequently seized group of new psychoactive substances. They are considered as β-keto analogs of amphetamine, sharing pharmacological effects with amphetamine and cocaine. This review describes the neurotoxic properties of synthetic cathinones, encompassing their capacity to induce neuroinflammation, dysregulate neurotransmitter systems, and alter monoamine transporters and receptors. Additionally, it discusses the rewarding and abuse potential of synthetic cathinones drawing from findings obtained through various preclinical animal models, contextualized with other classical psychostimulants. The review also offers an overview of current abuse trends of synthetic cathinones on the illicit drug market, specifying the aspects covered, and underscores the risks they pose to public health. Finally, the review discusses public health initiatives and efforts to reduce the hazards of synthetic cathinones, including harm reduction methods, education, and current clinical management strategies.

Standard Radio-Iodine Labeling Protocols Impaired the Functional Integrity of Mesenchymal Stem/Stromal Cell Exosomes.

Mesenchymal stem/stromal cells (MSCs) are an extensively studied cell type in clinical trials due to their easy availability, substantial ex vivo proliferative capacity, and therapeutic efficacy in numerous pre-clinical animal models of disease. The prevailing understanding suggests that their therapeutic impact is mediated by the secretion of exosomes. Notably, MSC exosomes present several advantages over MSCs as therapeutic agents, due to their non-living nature and smaller size. However, despite their promising therapeutic potential, the clinical translation of MSC exosomes is hindered by an incomplete understanding of their biodistribution after administration. A primary obstacle to this lies in the lack of robust labels that are highly sensitive, capable of directly and easily tagging exosomes with minimal non-specific labeling artifacts, and sensitive traceability with minimal background noise. One potential candidate to address this issue is radioactive iodine. Protocols for iodinating exosomes and tracking radioactive iodine in live imaging are well-established, and their application in determining the biodistribution of exosomes has been reported. Nevertheless, the effects of iodination on the structural or functional activities of exosomes have never been thoroughly examined. In this study, we investigate these effects and report that these iodination methods abrogate CD73 enzymatic activity on MSC exosomes. Consequently, the biodistribution of iodinated exosomes may reflect the biodistribution of denatured exosomes rather than functionally intact ones.

Sentinel lymph node identification using NIR-II ultrabright Raman nanotags on preclinical models

Surface-enhanced Raman spectroscopy (SERS) nanotags have garnered much attention as promising bioimaging contrast agent with ultrahigh sensitivity, but their clinical translation faces challenges including biological and laser safety. As breast sentinel lymph node (SLN) imaging agents, SERS nanotags used by local injection and only accumulation in SLNs, which were removed during surgery, greatly reduce biological safety concerns. But their clinical translation lacks pilot demonstration on large animals close to humans. The laser safety requires irradiance below the maximum permissible exposure threshold, which is currently not achievable in most SERS applications. Here we report the invention of the core-shell SERS nanotags with ultrahigh brightness (1 pM limit of detection) at the second near-infrared (NIR-II) window for SLN identification on pre-clinical animal models including rabbits and non-human primate. We for the first time realize the intraoperative SERS-guided SLN navigation under a clinically safe laser (1.73 J/cm2) and identify multiple axillary SLNs on a non-human primate. No evidence of biosafety issues was observed in systematic examinations of these nanotags. Our study unveils the potential of NIR-II SERS nanotags as appropriate SLN tracers, making significant advances toward the accurate positioning of lesions using the SERS-based tracer technique.