A multi-targeting drug design strategy for identifying potent anti-SARS-CoV-2 inhibitors.

The COVID-19, caused by SARS-CoV-2, is threatening public health, and there is no effective treatment. In this study, we have implemented a multi-targeted anti-viral drug design strategy to discover highly potent SARS-CoV-2 inhibitors, which simultaneously act on the host ribosome, viral RNA as well as RNA-dependent RNA polymerases, and nucleocapsid protein of the virus, to impair viral translation, frameshifting, replication, and assembly. Driven by this strategy, three alkaloids, including lycorine, emetine, and cephaeline, were discovered to inhibit SARS-CoV-2 with EC50 values of low nanomolar levels potently. The findings in this work demonstrate the feasibility of this multi-targeting drug design strategy and provide a rationale for designing more potent anti-virus drugs.

Neutrophils promote tumor resistance to radiation therapy.

Nearly two-thirds of cancer patients are treated with radiation therapy (RT), often with the intent to achieve complete and permanent tumor regression (local control). RT is the primary treatment modality used to achieve local control for many malignancies, including locally advanced cervical cancer, head and neck cancer, and lung cancer. The addition of concurrent platinum-based radiosensitizing chemotherapy improves local control and patient survival. Enhanced outcomes with concurrent chemoradiotherapy may result from increased direct killing of tumor cells and effects on nontumor cell populations. Many patients treated with concurrent chemoradiotherapy exhibit a decline in neutrophil count, but the effects of neutrophils on radiation therapy are controversial. To investigate the clinical significance of neutrophils in the response to RT, we examined patient outcomes and circulating neutrophil counts in cervical cancer patients treated with definitive chemoradiation. Although pretreatment neutrophil count did not correlate with outcome, lower absolute neutrophil count after starting concurrent chemoradiotherapy was associated with higher rates of local control, metastasis-free survival, and overall survival. To define the role of neutrophils in tumor response to RT, we used genetic and pharmacological approaches to deplete neutrophils in an autochthonous mouse model of soft tissue sarcoma. Neutrophil depletion prior to image-guided focal irradiation improved tumor response to RT. Our results indicate that neutrophils promote resistance to radiation therapy. The efficacy of chemoradiotherapy may depend on the impact of treatment on peripheral neutrophil count, which has the potential to serve as an inexpensive and widely available biomarker.

Multichamber Dysfunction in Children and Adolescents With Severe Obesity: A Cardiac Magnetic Resonance Imaging Myocardial Strain Study.

BACKGROUND: In severe obesity, left ventricular (LV) and right ventricular (RV) remodeling and contractile dysfunction have been documented, but less is known regarding left atrial (LA) dysfunction and its association with LV/RV remodeling, especially in children. PURPOSE: To assess the effects of severe childhood obesity on cardiac function by using multichamber strain analysis with MRI. STUDY TYPE: Prospective. SUBJECTS: Forty-five children aged 7-18 years (including 20 with severe obesity, defined as a body mass index values above the 99th percentile). FIELD STRENGTH: 5 T. SEQUENCE: Steady-state-free-precession (SSFP) images in short-axis views and longitudinal two- and four-chamber views. ASSESSMENT: Cardiac strain measurements were derived from standard SSFP cine images by using a dedicated MR imaging feature tracking software. Inter- and intra-rater reliability were evaluated. STATISTICAL TESTS: Independent sample t test, Spearman's correlation coefficient, principal component analysis, Bland-Altman analysis, and intra-class correlation coefficients (ICC). A P value <0.05 was considered statistically significant. RESULTS: As compared to children without obesity, those with obesity showed significantly reduced LA reservoir function (22.2% ± 6.4% vs. 33.8% ± 9.0%) and contractile function (5.4% ± 3.2% vs. 13.3% ± 8.0%) as well as significantly decreased absolute values for LA longitudinal strain in reservoir and contraction phases and LA radial motion fraction in reservoir and contraction phases. Children with severe obesity showed significantly reduced absolute RV radial motion fraction (-10.6% ± 2.9% vs. -18.2% ± 2.9%) and circumferential strain (-10.6% ± 2.9% vs. -16% ± 2.5%) as well as higher LV mass index (28.7% ± 5.1% vs. 21.7 ± 4.6 g/m2 ) along with significantly reduced LV ejection fraction (56.4% ± 3.9% vs. 60% ± 4.1%), LV radial strain (56% ± 6% vs. 61.8% ± 11.3%), and longitudinal strain (-17.8% ± 1.8% vs. -20.3% ± 3.2%). Reliability was good to excellent, with ICC ranging from 79.1% to 97.7%. DATA CONCLUSION: MR feature-tracking strain analysis revealed multichamber dysfunction in severely obese children with impaired LA reservoir and atrial contraction phases, which suggest an early loss in the compensatory ability of atrial contraction with severe obesity. LEVEL OF EVIDENCE: 2 TECHNICAL EFFICACY STAGE: 3.

Patients' and family members' perspectives on arrhythmias and sudden death in dialysis: the HeartLink focus groups pilot study.

BACKGROUND: Patients receiving dialysis face a high risk of cardiovascular disease, arrhythmia and sudden cardiac death. Few patients, however, are aware of this risk. Implantable cardiac monitors are currently available for clinical use and can continuously monitor cardiac rhythms without the need for transvenous leads. Our goal was to gauge patients' and family members' perceptions of these risks and to identify their concerns about cardiac monitors. METHODS: Two 90-minute focus groups were conducted: one with patients receiving in-center hemodialysis and one with their family members. Trained moderators assessed: (1) knowledge of cardiovascular disease; (2) cardiovascular disease risk in dialysis; (3) risk of death due to cardiovascular disease; (4) best ways to convey this risk to patients/families; and (5) concerns about cardiac monitors. The sessions were audiotaped, transcribed, and independently analyzed by two reviewers to identify core themes. Emblematic quotations were chosen to illustrate the final themes. RESULTS: Nine adult patients and three family members participated. Patients felt education was inadequate and had little knowledge of arrhythmias. Patients'/families' concerns regarding cardiac monitors were related to adverse effects, the notification process, and cosmetic effects. Patients/families felt that nephrologists, not dialysis staff, would be the best source for education. CONCLUSIONS: The preliminary data from this small study population suggest that patients/families are not well aware of the high risk of arrhythmia and sudden cardiac death in dialysis. Further investigation is required to gauge this awareness among patients/families and to assess their impressions of implantable cardiac monitors for arrhythmia detection and management.

Maternal folic acid supplementation with vitamin B12 deficiency during pregnancy and lactation affects the metabolic health of adult female offspring but is dependent on offspring diet.

Epidemiologic studies have reported relationships between maternal high folate and/or low B12 status during pregnancy and greater adiposity and insulin resistance in children. The goal of this study was to determine the effects of maternal folic acid supplementation (10 mg/kg diet), with (50 µg/kg diet) and without B12, on adult female offspring adiposity and glucose homeostasis. Female C57BL/6J mice were fed 1 of 3 diets from weaning and throughout breeding, pregnancy, and lactation: control (2 mg/kg diet folic acid, 50 µg/kg diet B12), supplemental folic acid with no B12 (SFA-B12), or supplemental folic acid with adequate B12 (SFA+B12). Female offspring were weaned onto the control diet or a Western diet (45% energy fat, 2 mg/kg diet folic acid, 50 µg/kg diet B12) for 35 wk. After weaning, control diet-fed offspring with SFA-B12 dams had fasting hyperglycemia, glucose intolerance, lower ß cell mass, and greater islet hepatocyte nuclear factor 1 homeobox α and nuclear receptor subfamily 1 group H member 3 mRNA than did offspring from control dams. In Western diet-fed offspring, those with SFA-B12 dams had lower fasting blood glucose and plasma insulin concentrations, and were smaller than control offspring. Our findings suggest that maternal folic acid supplementation with B12 deficiency during pregnancy/lactation programs the metabolic health of adult female offspring but is dependent on offspring diet.-Henderson, A. M., Tai, D. C., Aleliunas, R. E., Aljaadi, A. M., Glier, M. B., Xu, E. E., Miller, J. W., Verchere, C. B., Green, T. J., Devlin, A. M. Maternal folic acid supplementation with vitamin B12 deficiency during pregnancy and lactation affects the metabolic health of adult female offspring but is dependent on offspring diet.

Differences in Nanoparticle Uptake in Transplanted and Autochthonous Models of Pancreatic Cancer.

Human pancreatic ductal adenocarcinoma (PDAC) contains a distinctively dense stroma that limits the accessibility of anticancer drugs, contributing to its poor overall prognosis. Nanoparticles can enhance drug delivery and retention in pancreatic tumors and have been utilized clinically for their treatment. In preclinical studies, various mouse models differentially recapitulate the microenvironmental features of human PDAC. Here, we demonstrate that through utilization of different organic cosolvents and by doping of a homopolymer of poly(ε-caprolactone), a diblock copolymer composition of poly(ethylene oxide)- block-poly(ε-caprolactone) may be utilized to generate biodegradable and nanoscale micelles with different physical properties. Noninvasive optical imaging was employed to examine the pharmacology and biodistribution of these various nanoparticle formulations in both allografted and autochthonous mouse models of PDAC. In contrast to the results reported with transplanted tumors, spherical micelles as large as 300 nm in diameter were found to extravasate in the autochthonous model, reaching a distance of approximately 20 µm from the nearest tumor cell clusters. A lipophilic platinum(IV) prodrug of oxaliplatin was further able to achieve a ∼7-fold higher peak accumulation and a ∼50-fold increase in its retention half-life in pancreatic tumors when delivered with 100 nm long worm-like micelles as when compared to the free drug formulation of oxaliplatin. Through further engineering of nanoparticle properties, as well as by widespread adoption of the autochthonous tumor model for preclinical testing, future therapeutic formulations may further enhance the targeting and penetration of anticancer agents to improve survival outcomes in PDAC.

Wild-type microglia arrest pathology in a mouse model of Rett syndrome.

Rett syndrome is an X-linked autism spectrum disorder. The disease is characterized in most cases by mutation of the MECP2 gene, which encodes a methyl-CpG-binding protein. Although MECP2 is expressed in many tissues, the disease is generally attributed to a primary neuronal dysfunction. However, as shown recently, glia, specifically astrocytes, also contribute to Rett pathophysiology. Here we examine the role of another form of glia, microglia, in a murine model of Rett syndrome. Transplantation of wild-type bone marrow into irradiation-conditioned Mecp2-null hosts resulted in engraftment of brain parenchyma by bone-marrow-derived myeloid cells of microglial phenotype, and arrest of disease development. However, when cranial irradiation was blocked by lead shield, and microglial engraftment was prevented, disease was not arrested. Similarly, targeted expression of MECP2 in myeloid cells, driven by Lysm(cre) on an Mecp2-null background, markedly attenuated disease symptoms. Thus, through multiple approaches, wild-type Mecp2-expressing microglia within the context of an Mecp2-null male mouse arrested numerous facets of disease pathology: lifespan was increased, breathing patterns were normalized, apnoeas were reduced, body weight was increased to near that of wild type, and locomotor activity was improved. Mecp2(+/-) females also showed significant improvements as a result of wild-type microglial engraftment. These benefits mediated by wild-type microglia, however, were diminished when phagocytic activity was inhibited pharmacologically by using annexin V to block phosphatydilserine residues on apoptotic targets, thus preventing recognition and engulfment by tissue-resident phagocytes. These results suggest the importance of microglial phagocytic activity in Rett syndrome. Our data implicate microglia as major players in the pathophysiology of this devastating disorder, and suggest that bone marrow transplantation might offer a feasible therapeutic approach for it.

SOX4 cooperates with neurogenin 3 to regulate endocrine pancreas formation in mouse models.

AIMS/HYPOTHESIS: The sex-determining region Y (SRY)-related high mobility group (HMG) box (SOX) family of transcription factors is essential for normal organismal development. Despite the longstanding knowledge that many SOX family members are expressed during pancreas development, a role for many of these factors in the establishment of insulin-producing beta cell fate remains to be determined. The aim of this study is to elucidate the role of SOX4 during beta cell development. METHODS: We used pancreas and endocrine progenitor mouse knockouts of Sox4 to uncover the roles of SOX4 during pancreas development. Lineage tracing and in vitro models were used to determine how SOX4 regulates beta cell formation and understand the fate of Sox4-null endocrine lineage cells. RESULTS: This study demonstrates a progenitor cell-autonomous role for SOX4 in regulating the genesis of beta cells and shows that it is required at multiple stages of the process. SOX4 deletion in the multipotent pancreatic progenitors resulted in impaired endocrine progenitor cell differentiation. Deletion of SOX4 later in the Neurog3-expressing cells also caused reductions in beta cells. Lineage studies showed loss of Sox4 in endocrine progenitors resulted in a block in terminal islet cell differentiation that was attributed to reduction in the production of key beta cell specification factors. CONCLUSIONS/INTERPRETATION: These results demonstrate that SOX4 is essential for normal endocrine pancreas development both concomitant with, and downstream of, the endocrine fate decision. In conclusion, these studies position Sox4 temporally in the endocrine differentiation programme and provide a new target for improving in vitro differentiation of glucose-responsive pancreatic beta cells.

Frailty and Kidney Transplant Waitlisting: A Single-Center Experience.

BACKGROUND: Frailty is widely prevalent among kidney transplant (KT) candidates and is associated with poor peri and post-transplant outcomes. Whether frailty is a modifiable risk factor in KT candidates is unknown. Efforts to intervene in frailty have been hindered by a lack of a standardized approach to testing and treating frailty in clinical practice. METHODS: Patients undergoing evaluation for kidney transplantation underwent frailty testing during their clinical visits using a combination of the Short Physical Performance Battery (SPPB) and Groningen Frailty Indicator (GFI) instruments. Scores from the SPPB and GFI were combined to stratify patients into 4 risk groups. Patients in the highest-risk groups were referred to physical therapy (PT) and returned for repeat frailty testing. Pre- and post-PT scores were compared with assessment for improvement. RESULTS: Forty patients met the criteria for PT, of which 16 (40%) completed PT and returned for repeat frailty testing. The mean SPPB score improved from 5.88 to 8.94 after PT (P < .01). The mean GFI score improved from 5.25 to 4.06 after PT but was not statistically significant (P = .081). CONCLUSIONS: Our unique approach of using 2 validated scores, SPPB and GFI, together addressed many components of frailty evaluation, including physical, cognitive, and psychosocial components. We used PT as a targeted intervention for addressing both the physical and non-physical impairments among frail KT candidates. Physical therapy was noted to have a positive impact on each of these components.

Resveratrol and its metabolites elicit neuroprotection via high-affinity binding to the laminin receptor at low nanomolar concentrations.

Resveratrol prevents various neurodegenerative diseases in animal models despite reaching only low nanomolar concentrations in the brain after oral administration. In this study, based on the quenching of intrinsic tryptophan fluorescence and molecular docking, we found that trans-resveratrol, its conjugates (glucuronide and sulfate), and dihydro-resveratrol (intestinal microbial metabolite) bind with high affinities (Kd, 0.2-2 nm) to the peptide G palindromic sequence (near glycosaminoglycan-binding motif) of the 67-kDa laminin receptor (67LR). Preconditioning with low concentrations (0.01-10 nm) of these polyphenols, especially resveratrol-glucuronide, protected neuronal cells from death induced by serum withdrawal via activation of cAMP-mediated signaling pathways. This protection was prevented by a 67LR-blocking antibody, suggesting a role for this cell-surface receptor in neuroprotection by resveratrol metabolites.

Analysis of MRI brain biometrics in fetuses monitored for intra uterine growth restriction and their prognostic value: Results of a prospective multicenter study.

OBJECTIVE: Show a prognostic value of brain changes in fetuses with intra uterine growth restriction (IUGR) on early neonatal outcome. STUDY DESIGN: We prospectively recruited pregnant women whose fetuses presented fetal weight < 5th centile. A brain MRI was performed between 28 and 32 weeks of gestation (WG). Several brain biometrics were measured (as fronto-occipital diameter (FOD) and transverse cerebellar diameter (TCD)). Neonatal prognosis was evaluated according to a composite criterion. RESULTS: Of the 78 patients included, 62 had a fetal brain MRI. The mean centile value of FOD was lower in the unfavorable outcome group (n = 9) compared to the favorable outcome group (n = 53) (24.5 ± 16.8 vs. 8.6 ± 13.2, p = 0.004). The ROC curve for predicting risk of unfavorable neonatal outcome based on FOD presented an area under the curve of 0.81 (95 % CI, [0.63---0.99]) and a threshold determined at the 3rd centile was associated with sensitivity of 0.78 and a specificity of 0.89. In multivariate analysis, a FOD less than the 3rd centile was significantly associated with an unfavorable neonatal risk. There also was a reduction in TCD (25.5 ± 21.5 vs. 10.4 ± 10.4, p = 0.03) in the unfavorable neonatal outcome group. CONCLUSION: We found an association between a reduction in FOD and TCD in fetal MRIs conducted between 28 and 32 WG in fetuses monitored for IUGR with an unfavorable neonatal outcome. Our results suggest that these biometric changes could constitute markers of poor neonatal prognosis.

MR histology reveals tissue features beneath heterogeneous MRI signal in genetically engineered mouse models of sarcoma.

Purpose: To identify significant relationships between quantitative cytometric tissue features and quantitative MR (qMRI) intratumorally in preclinical undifferentiated pleomorphic sarcomas (UPS). Materials and methods: In a prospective study of genetically engineered mouse models of UPS, we registered imaging libraries consisting of matched multi-contrast in vivo MRI, three-dimensional (3D) multi-contrast high-resolution ex vivo MR histology (MRH), and two-dimensional (2D) tissue slides. From digitized histology we generated quantitative cytometric feature maps from whole-slide automated nuclear segmentation. We automatically segmented intratumoral regions of distinct qMRI values and measured corresponding cytometric features. Linear regression analysis was performed to compare intratumoral qMRI and tissue cytometric features, and results were corrected for multiple comparisons. Linear correlations between qMRI and cytometric features with p values of <0.05 after correction for multiple comparisons were considered significant. Results: Three features correlated with ex vivo apparent diffusion coefficient (ADC), and no features correlated with in vivo ADC. Six features demonstrated significant linear relationships with ex vivo T2*, and fifteen features correlated significantly with in vivo T2*. In both cases, nuclear Haralick texture features were the most prevalent type of feature correlated with T2*. A small group of nuclear topology features also correlated with one or both T2* contrasts, and positive trends were seen between T2* and nuclear size metrics. Conclusion: Registered multi-parametric imaging datasets can identify quantitative tissue features which contribute to UPS MR signal. T2* may provide quantitative information about nuclear morphology and pleomorphism, adding histological insights to radiological interpretation of UPS.

Transcriptional coactivator MED15 is required for beta cell maturation.

Mediator, a co-regulator complex required for RNA Polymerase II activity, interacts with tissue-specific transcription factors to regulate development and maintain homeostasis. We observe reduced Mediator subunit MED15 expression in endocrine hormone-producing pancreatic islets isolated from people living with type 2 diabetes and sought to understand how MED15 and Mediator control gene expression programs important for the function of insulin-producing ß-cells. Here we show that Med15 is expressed during mouse ß-cell development and maturation. Knockout of Med15 in mouse ß-cells causes defects in ß-cell maturation without affecting ß-cell mass or insulin expression. ChIP-seq and co-immunoprecipitation analyses found that Med15 binds ß-cell transcription factors Nkx6-1 and NeuroD1 to regulate key ß-cell maturation genes. In support of a conserved role during human development, human embryonic stem cell-derived ß-like cells, genetically engineered to express high levels of MED15, express increased levels of maturation markers. We provide evidence of a conserved role for Mediator in ß-cell maturation and demonstrate an additional layer of control that tunes ß-cell transcription factor function.

Preclinical Evaluation of the ATR Inhibitor BAY 1895344 as a Radiosensitizer for Head and Neck Squamous Cell Carcinoma.

PURPOSE: Despite aggressive multimodal treatment that typically includes definitive or adjuvant radiation therapy (RT), locoregional recurrence rates approach 50% for patients with locally advanced human papillomavirus (HPV)-negative head and neck squamous cell carcinoma (HNSCC). Thus, more effective therapeutics are needed to improve patient outcomes. We evaluated the radiosensitizing effects of ataxia telangiectasia and RAD3-related (ATR) inhibitor (ATRi) BAY 1895344 in preclinical models of HNSCC. METHODS AND MATERIALS: Murine and human HPV-negative HNSCC cells (MOC2, MOC1, JHU-012) were treated with vehicle or ATRi with or without 4 Gy. Checkpoint kinase 1 phosphorylation and DNA damage (γH2AX) were evaluated by Western blot, and ATRi half-maximal inhibitory concentration was determined by MTT assay for HNSCC cells and immortalized murine oral keratinocytes. In vitro radiosensitization was tested by clonogenic assay. Cell cycle distribution and mitotic catastrophe were evaluated by flow cytometry. Mitotic aberrations were quantified by fluorescent microscopy. Tumor growth delay and survival were assessed in mice bearing MOC2 or JHU-012 transplant tumors treated with vehicle, ATRi, RT (10 Gy × 1 or 8 Gy × 3), or combined ATRi + RT. RESULTS: ATRi caused dose-dependent reduction in checkpoint kinase 1 phosphorylation at 1 hour post-RT (4 Gy) and dose-dependent increase in γH2AX at 18 hours post-RT. Addition of RT to ATRi led to decreased BAY 1895344 half-maximal inhibitory concentration in HNSCC cell lines but not in normal tissue surrogate immortalized murine oral keratinocytes. Clonogenic assays demonstrated radiosensitization in the HNSCC cell lines. ATRi abrogated the RT-induced G2/M checkpoint, leading to mitosis with unrepaired DNA damage and increased mitotic aberrations (multinucleated cells, micronuclei, nuclear buds, nucleoplasmic bridges). ATRi and RT significantly delayed tumor growth in MOC2 and JHU-012 in vivo models, with improved overall survival in the MOC2 model. CONCLUSIONS: These findings demonstrated that BAY 1895344 increased in vitro and in vivo radiosensitivity in HPV-negative HNSCC preclinical models, suggesting therapeutic potential warranting evaluation in clinical trials for patients with locally advanced or recurrent HPV-negative HNSCC.

Ego4D: Around the World in 3,000 Hours of Egocentric Video.

We introduce Ego4D, a massive-scale egocentric video dataset and benchmark suite. It offers 3,670 hours of daily-life activity video spanning hundreds of scenarios (household, outdoor, workplace, leisure, etc.) captured by 931 unique camera wearers from 74 worldwide locations and 9 different countries. The approach to collection is designed to uphold rigorous privacy and ethics standards, with consenting participants and robust de-identification procedures where relevant. Ego4D dramatically expands the volume of diverse egocentric video footage publicly available to the research community. Portions of the video are accompanied by audio, 3D meshes of the environment, eye gaze, stereo, and/or synchronized videos from multiple egocentric cameras at the same event. Furthermore, we present a host of new benchmark challenges centered around understanding the first-person visual experience in the past (querying an episodic memory), present (analyzing hand-object manipulation, audio-visual conversation, and social interactions), and future (forecasting activities). By publicly sharing this massive annotated dataset and benchmark suite, we aim to push the frontier of first-person perception. Project page: https://ego4d-data.org/.

Acid Base Disorders in Cirrhosis.

Metabolic and respiratory acid-base disorders are common in individuals with liver disease and cirrhosis. The most common disorder is respiratory alkalosis, which may be related to dyspnea or respiratory stimulation. Primary metabolic disorders are less common. Although the liver plays a role in metabolism of amino acids and generation of acid from dietary sources, it does not play a role in the regulation of pH. Instead, metabolic disorders may arise from alterations in normal metabolism or from medications, particularly diuretics and osmotic laxatives, used in the treatment of these complex patients. Understanding the mechanistic underpinnings of these disorders can aid in the management of individuals with liver disease in the hospital and in outpatient settings.

In Silico Identification and In Vitro Validation of Repurposed Compounds Targeting the RSV Polymerase.

Respiratory Syncytial Virus (RSV) is the top cause of infant hospitalization globally, with no effective treatments available. Researchers have sought small molecules to target the RNA-dependent RNA Polymerase (RdRP) of RSV, which is essential for replication and transcription. Based on the cryo-EM structure of the RSV polymerase, in silico computational analysis including molecular docking and the protein-ligand simulation of a database, including 6554 molecules, is currently undergoing phases 1-4 of clinical trials and has resulted in the top ten repurposed compound candidates against the RSV polymerase, including Micafungin, Totrombopag, and Verubecestat. We performed the same procedure to evaluate 18 small molecules from previous studies and chose the top four compounds for comparison. Among the top identified repurposed compounds, Micafungin, an antifungal medication, showed significant inhibition and binding affinity improvements over current inhibitors such as ALS-8112 and Ribavirin. We also validated Micafungin's inhibition of the RSV RdRP using an in vitro transcription assay. These findings contribute to RSV drug development and hold promise for broad-spectrum antivirals targeting the non-segmented negative-sense (NNS) RNA viral polymerases, including those of rabies (RABV) and Ebola (EBOV).

Type 2 diabetes susceptibility gene GRK5 regulates physiological pancreatic ß-cell proliferation via phosphorylation of HDAC5.

Restoring functional ß cell mass is a potential therapy for those with diabetes. However, the pathways regulating ß cell mass are not fully understood. Previously, we demonstrated that Sox4 is required for ß cell proliferation during prediabetes. Here, we report that Sox4 regulates ß cell mass through modulating expression of the type 2 diabetes (T2D) susceptibility gene GRK5. ß cell-specific Grk5 knockout mice showed impaired glucose tolerance with reduced ß cell mass, which was accompanied by upregulation of cell cycle inhibitor gene Cdkn1a. Furthermore, we found that Grk5 may drive ß cell proliferation through a pathway that includes phosphorylation of HDAC5 and subsequent transcription of immediate-early genes (IEGs) such as Nr4a1, Fosb, Junb, Arc, Egr1, and Srf. Together, these studies suggest GRK5 is linked to T2D through regulation of ß cell growth and that it may be a target to preserve ß cells during the development of T2D.

Mis-splicing Drives Loss of Function of p53E224D Point Mutation.

Background: Tp53 is the most commonly mutated gene in cancer. Canonical Tp53 DNA damage response pathways are well characterized and classically thought to underlie the tumor suppressive effect of Tp53. Challenging this dogma, mouse models have revealed that p53 driven apoptosis and cell cycle arrest are dispensable for tumor suppression. Here, we investigated the inverse context of a p53 mutation predicted to drive expression of canonical targets, but is detected in human cancer. Methods: We established a novel mouse model with a single base pair mutation (GAG>GAC, p53E221D) in the DNA-Binding domain that has wild-type function in screening assays, but is paradoxically found in human cancer in Li-Fraumeni syndrome. Using mouse p53E221D and the analogous human p53E224D mutant, we evaluated expression, transcriptional activation, and tumor suppression in vitro and in vivo. Results: Expression of human p53E224D from cDNA translated to a fully functional p53 protein. However, p53E221D/E221D RNA transcribed from the endogenous locus is mis-spliced resulting in nonsense mediated decay. Moreover, fibroblasts derived from p53E221D/E221D mice do not express a detectable protein product. Mice homozygous for p53E221D exhibited increased tumor penetrance and decreased life expectancy compared to p53 WT animals. Conclusions: Mouse p53E221D and human p53E224D mutations lead to splice variation and a biologically relevant p53 loss of function in vitro and in vivo.

Neoadjuvant Radiation Therapy and Surgery Improves Metastasis-Free Survival over Surgery Alone in a Primary Mouse Model of Soft Tissue Sarcoma.

This study aims to investigate whether adding neoadjuvant radiotherapy (RT), anti-programmed cell death protein-1 (PD-1) antibody (anti-PD-1), or RT + anti-PD-1 to surgical resection improves disease-free survival for mice with soft tissue sarcomas (STS). We generated a high mutational load primary mouse model of STS by intramuscular injection of adenovirus expressing Cas9 and guide RNA targeting Trp53 and intramuscular injection of 3-methylcholanthrene (MCA) into the gastrocnemius muscle of wild-type mice (p53/MCA model). We randomized tumor-bearing mice to receive isotype control or anti-PD-1 antibody with or without radiotherapy (20 Gy), followed by hind limb amputation. We used micro-CT to detect lung metastases with high spatial resolution, which was confirmed by histology. We investigated whether sarcoma metastasis was regulated by immunosurveillance by lymphocytes or tumor cell-intrinsic mechanisms. Compared with surgery with isotype control antibody, the combination of anti-PD-1, radiotherapy, and surgery improved local recurrence-free survival (P = 0.035) and disease-free survival (P = 0.005), but not metastasis-free survival. Mice treated with radiotherapy, but not anti-PD-1, showed significantly improved local recurrence-free survival and metastasis-free survival over surgery alone (P = 0.043 and P = 0.007, respectively). The overall metastasis rate was low (∼12%) in the p53/MCA sarcoma model, which limited the power to detect further improvement in metastasis-free survival with addition of anti-PD-1 therapy. Tail vein injections of sarcoma cells into immunocompetent mice suggested that impaired metastasis was due to inability of sarcoma cells to grow in the lungs rather than a consequence of immunosurveillance. In conclusion, neoadjuvant radiotherapy improves metastasis-free survival after surgery in a primary model of STS.