Citations

Integrative single-cell analysis de-constructs the heterogeneity of human reprogramming and uncovers its stage-specific GRNs.

AbstractHeart regeneration occurs by dedifferentiation and proliferation of pre-existing cardiomyocytes (CMs). However, the signaling mechanisms by which injury induces CM renewal remain incompletely understood. Here, we find that cardiac injury in zebrafish induces expression of the secreted Wnt inhibitors, including Dickkopf 1 (Dkk1), Dkk3, secreted Frizzled-related protein 1 (sFrp1), and sFrp2, in cardiac tissue adjacent to injury sites. Experimental blocking of Wnt activity via Dkk1 overexpression enhances CM proliferation and heart regeneration, whereas ectopic activation of Wnt8 signaling blunts injury-induced CM dedifferentiation and proliferation. Although Wnt signaling is dampened upon injury, the cytoplasmic β-catenin is unexpectedly increased at disarrayed CM sarcomeres in myocardial wound edges. Our analyses indicated that p21-activated kinase 2 (Pak2) is induced at regenerating CMs, where it phosphorylates cytoplasmic β-catenin at Ser 675 and increases its stability at disassembled sarcomeres. Myocardial-specific induction of the phospho-mimetic β-catenin (S675E) enhances CM dedifferentiation and sarcomere disassembly in response to injury. Conversely, inactivation of Pak2 kinase activity reduces the Ser 675-phosphorylated β-catenin (pS675-β-catenin) and attenuates CM sarcomere disorganization and dedifferentiation. Taken together, these findings demonstrate that coordination of Wnt signaling inhibition and Pak2/pS675-β-catenin signaling enhances zebrafish heart regeneration by supporting CM dedifferentiation and proliferation.

Abstract In the current work we show that the profibrotic actions of TGF‐β are mediated, at least in part, through a metabolic maladaptation in glutamine metabolism and how the inhibition of glutaminase 1 (GLS1) reverses pulmonary fibrosis. GLS1 was found to be highly expressed in fibrotic vs normal lung fibroblasts and the expression of profibrotic targets, cell migration, and soft agar colony formation stimulated by TGF‐β required GLS1 activity. Moreover, knockdown of SMAD2 or SMAD3 as well as inhibition of PI3K, mTORC2, and PDGFR abrogated the induction of GLS1 by TGF‐β. We further demonstrated that the NAD‐dependent protein deacetylase, SIRT7, and the FOXO4 transcription factor acted as endogenous brakes for GLS1 expression, which are inhibited by TGF‐β. Lastly, administration of the GLS1 inhibitor CB‐839 attenuated bleomycin‐induced pulmonary fibrosis. Our study points to an exciting and unexplored connection between epigenetic and transcriptional processes that regulate glutamine metabolism and fibrotic development in a TGF‐β‐dependent manner.

Understanding temporal dynamics of COVID-19 symptoms could provide fine-grained resolution to guide clinical decision-making. Here, we use deep neural networks over an institution-wide platform for the augmented curation of clinical notes from 77,167 patients subjected to COVID-19 PCR testing. By contrasting Electronic Health Record (EHR)-derived symptoms of COVID-19-positive (COVID pos ; n = 2,317) versus COVID-19-negative (COVID neg ; n = 74,850) patients for the week preceding the PCR testing date, we identify anosmia/dysgeusia (27.1-fold), fever/chills (2.6-fold), respiratory difficulty (2.2-fold), cough (2.2-fold), myalgia/arthralgia (2-fold), and diarrhea (1.4-fold) as significantly amplified in COVID pos over COVID neg patients. The combination of cough and fever/chills has 4.2-fold amplification in COVID pos patients during the week prior to PCR testing, in addition to anosmia/dysgeusia, constitutes the earliest EHR-derived signature of COVID-19. This study introduces an Augmented Intelligence platform for the real-time synthesis of institutional biomedical knowledge. The platform holds tremendous potential for scaling up curation throughput, thus enabling EHR-powered early disease diagnosis.

AbstractThe corticostriatal circuitry and its glutamate‐γ‐aminobuturic acid (GABA) interactions play an essential role in regulating neuronal excitability during reward‐seeking behavior. However, the contribution of GABAergic interneurons in the corticostriatal circuitry remains unclear. To investigate the role of GABAergic interneurons, we focused on parvalbumin‐expressing fast‐spiking interneurons (Pv‐FSI) in the corticostriatal circuitry using the designer receptors exclusively activated by designer drugs approach in a Pv‐Cre mouse model. We hypothesize that Pv‐FSI activation elicits changes in cortical glutamate levels and reward‐seeking behaviors. To determine molecular and behavioral effects of Pv‐FSI, we performed microdialysis and operant conditioning tasks for sucrose and alcohol rewards. In addition, we also examined how alcohol reward itself affects Pv‐FSI functioning. Interestingly, our microdialysis results demonstrate that alcohol exposure inhibits Pv‐FSI functioning in the medial prefrontal cortex (mPFC) and this consequently can regulate glutamate levels downstream in the nucleus accumbens. For sucrose reward‐seeking behaviors, Pv‐FSI activation in the mPFC increases sucrose self‐administration whereas it does not promote alcohol seeking. For alcohol rewards, however, Pv‐FSI activation in the mPFC results in increased compulsive head entry in operant chambers during devaluation procedures. Overall, our results suggest that not only do Pv‐FSI contribute to changes in the cortical microcircuit and reward‐seeking behaviors but also that alcohol affects Pv‐FSI neurotransmission. Therefore, Pv‐FSI has prompted interest in their role in maintaining a balance in neuronal excitation/inhibition and in regulating reward‐seeking processes such as compulsivity, all of which are important factors for excessive alcohol seeking. image

ABSTRACT Background Implementation of checklists has been shown to be effective in improving patient safety. This study aims to evaluate the effectiveness of implementation of a checklist for daily care processes into clinical practice of pediatric intensive care units (PICUs) with limited resources. Methods Prospective before–after study in eight PICUs from China, Congo, Croatia, Fiji, and India after implementation of a daily checklist into the ICU rounds. Results Seven hundred and thirty-five patients from eight centers were enrolled between 2015 and 2017. Baseline stage had 292 patients and post-implementation 443. The ICU length of stay post-implementation decreased significantly [9.4 (4–15.5) vs. 7.3 (3.4–13.4) days, p = 0.01], with a nominal improvement in the hospital length of stay [15.4 (8.4–25) vs. 12.6 (7.5–24.4) days, p = 0.055]. The hospital mortality and ICU mortality between baseline group and post-implementation group did not show a significant difference, 14.4% vs. 11.3%; p = 0.22 for each. There was a variable impact of checklist implementation on adherence to various processes of care recommendations. A decreased exposure in days was noticed for; mechanical ventilation from 42.6% to 33.8%, p < 0.01; central line from 31.3% to 25.3%, p < 0.01; and urinary catheter from 30.6% to 24.4%, p < 0.01. Although there was an increased utilization of antimicrobials (89.9–93.2%, p < 0.01). Conclusions Checklists for the treatment of acute illness and injury in the PICU setting marginally impacted the outcome and processes of care. The intervention led to increasing adherence with guidelines in multiple ICU processes and led to decreased length of stay.

OBJECTIVEThe goal of this study was to determine the functional efficacy of acellular processed nerve allograft (ALG) as compared to sural nerve autograft (AUG) harvested at time of surgery for children with obstetrical brachial plexus injury (OBPI).METHODSA retrospective review of records was performed in patients who underwent surgical repair of OBPI between 2009 and 2015 at Phoenix Children’s Hospital. Patients were grouped based on the type of nerve graft used (AUG using the patient’s own sural nerve or decellularized processed cadaveric nerve ALG) and compared in terms of motor strength, British Medical Research Council score, functionality (Mallet scale score), surgical time, rate of complications, and need for further intervention.RESULTSA total of 52 records were identified meeting study criteria. Sural nerve AUG was used in 22 cases and ALG in 30 cases. Changes from pre- to postsurgical assessment of motor strength were significant for all muscle groups measured except for elbow extension for both groups. All Mallet scores increased significantly. No significant differences were observed in motor strength and functional components between groups. Interventions using ALG had shorter operative times than those performed using AUG. No significant difference was observed in terms of need for further intervention. Two patients (9%) in the AUG group developed stitch abscesses at the harvest site, whereas there were no infectious complications reported in the ALG group.CONCLUSIONSThese findings suggest equivalence in terms of muscle strength and functional outcomes between the use of AUG and ALG for patients with OBPI. However, the less invasive character of ALG repair decreases surgical time and risk of complications.

4508 Background: The combination of dual immune checkpoint inhibitors (ICI) T (anti–CTLA-4) and D (anti–PD-L1) showed tolerability with a promising objective response rate (ORR) in the initial cohort of this study (NCT02519348). Subsequent evaluation of pts with solid tumors treated with increasing doses of T suggested priming with a higher dose of T may induce a stronger immune response and enhance anti-tumor activity. Thus, the randomized expansion cohorts comprised 4 arms evaluating T and D as monotherapies and 2 T+D regimens, including a novel T+D regimen featuring a single, priming dose of T. Methods: ICI-naïve pts with aHCC who progressed on, were intolerant to, or refused sorafenib were randomized to one of two T+D combinations: T300+D (T 300 mg + D 1500 mg 1 dose followed by D Q4 weekly [Q4W]) or T75+D (T 75 mg Q4W + D 1500 mg Q4W [4 doses] followed by D Q4W); or single agent D (1500 mg Q4W) or T (750 mg Q4W). Safety was the primary endpoint. ORR by blinded, independent central review using RECIST v1.1, duration of response (DoR), circulating lymphocytes, and overall survival (OS) were assessed. Results: At data cut-off (09/02/2019), 332 pts were enrolled. Median follow-ups were 11.7 months (mo) for T300+D, 14.6 (T75+D), 8.9 (D), and 15.8 (T). Treatment-related adverse event (trAE) incidences are shown (Table); no deaths were attributed to trAEs for T300+D or T. The T300+D arm had the highest confirmed ORR (DoR not reached [NR]) and longest OS (Table). A unique proliferative T cell profile was identified for pts in the T300+D arm, suggesting additive biologic activity for the combination, and showed pts with an OR exhibited high cytotoxic (CD8) counts. Conclusions: The encouraging clinical activity and tolerable safety profile suggest T300+D provides the best benefit-risk profile as opposed to T75+D or monotherapies. The unique pharmacodynamic activity of the T300+D regimen further supports its use in aHCC. T300+D and D are being evaluated in the ongoing phase III HIMALAYA study (NCT03298451) in first-line HCC vs sorafenib. Funding: AstraZeneca. Clinical trial information: NCT02519348 . [Table: see text]

3594 Background: Selpercatinib (LOXO-292) is a highly selective and potent small molecule RET kinase inhibitor. Here we report an update on the efficacy and safety of selpercatinib in RET-mutant medullary thyroid cancer (MTC). Methods: Patients with RET-mutant MTC were enrolled to the Phase 1/2 LIBRETTO-001 trial (NCT03157128), a global, multicenter trial (16 countries, 89 sites). Following the Phase 1 dose escalation portion of the trial, patients received the recommended dose of 160 mg orally twice daily. Each cycle was 28 days. The primary endpoint was objective response rate (ORR) per RECIST 1.1. Secondary endpoints included duration of response (DoR) and safety. Per health authority agreement, the primary analysis set was defined as the first 55 consecutively enrolled patients previously treated with multikinase inhibitors cabozantinib and/or vandetanib. Patients naïve to cabozantinib and vandetanib treatment were analyzed separately. All analyses were based on a 16-Dec-2019 data cutoff date. Results: In the primary analysis set of prior cabozantinib and/or vandetanib-treated patients with MTC (n = 55), the ORR by investigator assessment was 62% (95% CI 47.7–74.6, n = 34/55) and the median DoR was not reached (95% CI 18.4 months–not estimable) despite a median follow-up of 14.8 months. In cabozantinib/vandetanib treatment-naïve patients (n = 88), the ORR by investigator assessment was 69% (95% CI 58.6–78.7, n = 61/88, including 2 responses pending confirmation). Of the 59 confirmed responding patients, with a median follow-up of 8 months, responses were ongoing for 57 responders at the time of the analysis. In the safety analysis set consisting of all selpercatinib dosed patients (N = 702), the most common treatment-related adverse events (TRAEs) that occurred in ≥15% of patients were dry mouth (33.3%), increased AST (24.5%), increased ALT (23.8%), hypertension (23.2%), diarrhea (19.7%), and fatigue (16.8%). Only 2% (14 of 702) of patients discontinued selpercatinib for TRAEs. Conclusions: Selpercatinib use was associated with marked and durable antitumor activity in prior cabozantinib and/or vandetanib-treated patients and in cabozantinib/vandetanib-naïve patients with RET-mutant MTC, with the majority of responses ongoing in both cohorts. Selpercatinib was well tolerated. Efficacy data assessed by independent review committee based on the 16-Dec-2019 data cutoff date will be presented. Clinical trial information: NCT03157128 .