Comparative assessment of radiation therapy-induced vasculitis using [18F]FDG-PET/CT in patients with non-small cell lung cancer treated with proton versus photon radiotherapy

PURPOSE

To assess radiation therapy (RT)-induced vasculitis in patients with non-small cell lung cancer (NSCLC) by examining changes in the uptake of 18F-fluoro-D-deoxyglucose ([18F]FDG) by positron emission tomography/computed tomography (PET/CT) images of the ascending aorta (AA), descending aorta (DA), and aortic arch (AoA) before and after proton and photon RT.

METHOD

Thirty-five consecutive locally advanced NSCLC patients were definitively treated with proton (n = 27) or photon (n = 8) RT and concurrent chemotherapy. The patients were prospectively enrolled to undergo [18F]FDG-PET/CT imaging before and 3 months after RT. An adaptive contrast-oriented thresholding algorithm was applied to generate mean standardized uptake values (SUVmean) for regions of interest (ROIs) 3 mm outside and 3 mm inside the outer perimeter of the AA, DA, and AoA. These ROIs were employed to exclusively select the aortic wall and remove the influence of blood pool activity. SUVmeans before and after RT were compared using two-tailed paired t-tests.

RESULTS

RT treatments were associated with increased SUVmeans in the AA, DA, and AoA-1.9%, 0.3%, and 1.3% for proton and 15.8%, 9.5%, and 15.5% for photon, respectively. There was a statistically significant difference in the ∆SUVmean (post-RT SUVmean - pre-RT SUVmean) in patients treated with photon RT when compared to ∆SUVmean in patients treated with proton RT in the AA (p = 0.043) and AoA (p = 0.015). There was an average increase in SUVmean that was related to dose for photon patients (across structures), but that was not seen for proton patients, although the increase was not statistically significant.

CONCLUSION

Our results suggest that patients treated with photon RT for NSCLC may exhibit significantly more RT-induced inflammation (measured as ∆SUVmean) in the AA and AoA when compared to patients who received proton RT. Knowledge gained from further analyses in larger cohorts could aid in treatment planning and help prevent the significant morbidity and mortality associated with RT-induced vascular complications.

TRIAL REGISTRATION

NCT02135679.

Generation of an Alagille syndrome (ALGS) patient-derived induced pluripotent stem cell line (TRNDi032-A) carrying a heterozygous mutation (p.Cys682Leufs*7) in the JAG1 gene

Alagille syndrome (ALGS) is an autosomal dominant, multisystemic disorder due to haploinsufficiency in either the JAG1 gene (ALGS type 1) or the NOTCH2 gene (ALGS type 2). The disease has been difficult to diagnose and treat due to its muti-system clinical presentation, variable expressivity, and prenatal onset for some of the features. The generation of this iPSC line (TRNDi032-A) carrying a heterozygous mutation, p.Cys682Leufs*7 (c.2044dup), in the JAG1 gene provides a means of studying the disease and developing novel therapeutics towards patient treatment.

[Progress in intelligent antibacterial materials for dental caries]

Anti-caries strategies that based on the regulation of oral micro-ecology have recently drawn broad attention. Intelligent antibacterial materials have shown great potential for ecological anti-caries strategies, which can response to microenvironment of dental caries or external stimuli and inhibit cariogenic biofilms precisely. This technology could improve local anti-caries effect and help maintain oral micro-eubiosis. Here, we reviewed recent progress in intelligent anti-bacterial materials for dental caries. The future research direction was also prospected. We hope that by discussing about this new technology of prevention and treatment for dental caries, this review could provide ideas for the research on novel anti-caries materials.

Clinical Validation of HPV ctDNA for Early Detection of Residual Disease Following Chemoradiation in Cervical Cancer

PURPOSE/OBJECTIVE(S)

Despite chemoradiation (CRT), 30-40% of patients with locally advanced cervical cancer relapse. Most cases are caused by human papilloma virus (HPV), and HPV circulating tumor DNA (ctDNA) may identify patients at highest risk of relapse. Our previous pilot study showed that detectable HPV ctDNA at the end of CRT is associated with inferior progression-free survival (PFS) using digital polymerase chain reaction (dPCR), and that a next generation sequencing approach (HPV-seq) may outperform dPCR. We hypothesized that HPV ctDNA may identify cervical cancer patients at increased risk of relapse following CRT and aimed to prospectively validate HPV ctDNA as a tool for early detection of residual disease.

MATERIALS/METHODS

This prospective, multicenter validation study accrued 70 patients with HPV+ stage IB-IVA cervical cancer treated with definitive CRT from 2017-2022. Patients underwent phlebotomy at baseline, end of, 4-6 weeks and 3 months post CRT for HPV ctDNA levels. HPV genotyping was performed on the baseline plasma sample using HPV-seq. HPV genotype-specific DNA levels in plasma were quantified using both dPCR and HPV-seq. PFS was estimated using the Kaplan-Meier method and compared using the log rank test. Multivariable Cox regression analyses incorporating stage and HPV ctDNA detectability assessed independent prognostic factors associated with PFS.

RESULTS

At the time of abstract, results for 67 patients were available. The majority had squamous histology (84%) and stage IIB (36%) or IIIC1 (25%) disease. HPV genotyping using HPV-seq revealed 54% (36/67) of cases harboring HPV-16, and 46% harboring other HPV types: 15 HPV-18; 5 HPV-59; 2 HPV-31; 2 HPV-33; 2 HPV-52; 1 each HPV-39, HPV-45, HPV-53, HPV-58, and HPV-82. With a median follow up of 2.2 (range 0.4 - 5.2) years, there were 21 PFS events. Most recurrences (14/21) were distant and/or paraaortic; 4 local and nodal/distant; 2 pelvic nodal; and 1 local. Patients with detectable HPV ctDNA on dPCR at the end of, 4-6 weeks and 3 months post CRT had significantly worse 2-year PFS compared to those with undetectable HPV ctDNA (78 vs 52%, p = 0.04; 82 vs 26%, p < 0.001; and 80 vs 23%, p = < 0.001, respectively). HPV-seq showed similar results (87 vs 55%, p = 0.02; 81 vs 45%, p = 0.003; and 84 vs 31%, p = < 0.001, respectively). On multivariable analyses, detectable HPV ctDNA on dPCR and HPV-seq remained independently associated with inferior PFS (see table).

CONCLUSION

HPV-seq enables HPV genotyping directly from plasma in locally advanced cervical cancer. Persistent HPV ctDNA following CRT is independently associated with inferior PFS in this prospective validation study. HPV ctDNA testing can be used to identify, as early as at the end of CRT, patients at high risk of recurrence in future treatment intensification trials.

Effectiveness of Cisplatin in P16+ Oropharyngeal Cancer According to Relative Risk for Cancer Events: Ancillary Analysis of RTOG 1016

PURPOSE/OBJECTIVE(S)

To test the hypothesis that the effectiveness of cisplatin in p16+ oropharyngeal squamous cell carcinoma (OPSCC) increases with patients' relative risk for cancer events.

MATERIALS/METHODS

Ancillary analysis of 805 patients enrolled on RTOG 1016 accessed via Project DataSphere. Eligible patients had p16+ OPSCC, AJCC 7th T1-T2 N2a-N3 or T3-T4 N0-N3 M0, ECOG PS 0-1. Patients were randomized to RT with concurrent cisplatin vs. cetuximab. Relative risk for competing events was quantified using the Head and Neck Cancer Intergroup predictive classifier (omega score). Higher scores indicate higher relative risk for cancer events (LRF or distant metastasis) vs. competing mortality. We compared this to favorable, unfavorable/low, and unfavorable/intermediate risk groups using standard criteria: NRG HN005 eligible/low RTOG risk (Ang et al.), HN005 ineligible/low RTOG risk, and intermediate RTOG risk. Omega score cutoffs were selected to match numbers in standard risk strata. HRs for the effect of cisplatin vs. cetuximab on PFS and OS were compared for standard vs. relative risk strata. 1-tailed interaction tests were used to test whether cisplatin effectiveness increased within risk strata.

RESULTS

There were 354, 219, and 232 patients in standard favorable, unfavorable/low, and unfavorable/intermediate risk groups. Omega score cutoffs were 0.80 and 0.84 to define low, intermediate, and high relative risk groups. Discordant standard vs. relative risk classifications occurred in 559 patients (69.4%). Increasing omega score was associated with significantly higher relative HR (rHR) for cancer events (3.40, 95% CI: 1.66-6.96) and increasing effectiveness of cisplatin vs. cetuximab (Table), but standard risk grouping was not (rHR 0.80, 95% CI: 0.49-1.32). The effect of cisplatin on PFS significantly increased with higher omega score (interaction -0.30, p = .046), but decreased with increasing standard risk strata (interaction +0.27, p = NS).

CONCLUSION

The effectiveness of cisplatin in p16+ OPSCC increased with higher omega score but not with standard risk group. Relative risk for cancer events should be taken into account when designing deintensification strategies.

Analysis of Institutional DIBH Coaching Program for Surface Guided-DIBH Patients

PURPOSE/OBJECTIVE(S)

Our institute has implemented a surface guided-DIBH (SG-DIBH) coaching program which involves consultation, pre-treatment (CT-sim) and treatment. We would like to analyze the effectiveness of the program.

MATERIALS/METHODS

A total of 72 left breast cancer patients between 1st Apr 2022 to 9th Dec 2022 were registered for radiation treatment. During consultation, oncologist selected suitable patients based on the following criteria: a) age of 18-70; b) left breast cancer, right breast cancer with internal mammary nodes irradiation or dextrocardia; c) no lung/cardiac disease history & d) volunteer for SG-DIBH technique. The eligible patients were then trained by the coaching therapist using a teaching video and practiced at home. During CT simulation, patients were assessed according to the DIBH evaluation form. The evaluation components included patient's compliancy and understanding, the differences of lateral skin marking (free breathing, FB vs DIBH), duration of breath hold and reproducibility. Patients who passed the evaluation were scanned under both FB and DIBH for SG-DIBH treatment. IMRT-FFF 6 to 7 fields were planned. During SG-DIBH treatment, first 3 fractions and weekly CBCT were taken. Patients were encouraged to continue DIBH practice at home throughout whole course of the treatment and they were given 3 identical survey forms (5 questions) at the beginning, middle and end of treatment. The measure for the success of this coaching program would be number of breath-holds, duration of treatment time, treatment accuracy (CBCT matching) and survey results.

RESULTS

There were 48 patients who were eligible for DIBH coaching program, however, only 24 patients had passed the coaching evaluation and 20 patients were treated with SG-DIBH technique successfully. The mean of number of breath-hold and treatment time was 7 times and 7.9 minutes. Total of 123 CBCT images were studied. The setup errors were (0.242±0.180) cm, (0.152±0.137) cm, (0.202±0.165) cm, (0.684±0.640) degrees, (0.816±0.767) degrees, (0.912±0.707) degrees in lateral, longitudinal, vertical, pitch, roll and yaw directions. According to the survey analysis, the number of times to practice at home decreased as the treatment went by. An improvement was seen in patients' self-evaluation in mastering DIBH technique with proper coaching program (from 60% to 90%). Patients' anxiety in performing DIBH were alleviated greatly towards the end of the treatment (from 47% to 15%). 100% of the patients were willing to go for DIBH treatment if given a second chance and additional suggestions claimed that professional clinical teams and coaching program were important for their DIBH treatment journey.

CONCLUSION

A comprehensive DIBH coaching program can effectively identify SG-DIBH patient's suitability. Patient compliancy, treatment accuracy and treatment experience can be enhanced with good coaching program. The involvement of clinical team from consultation to pre-treatment and treatment stage is essential for a successful SG-DIBH treatment.

Comparison of Standard vs. Relative Risk Models to Define Candidates for Deintensification in Locoregionally Advanced P16+ Oropharyngeal Cancer

PURPOSE/OBJECTIVE(S)

Various methods to identify candidates for treatment deintensification with p16+ oropharyngeal squamous cell carcinoma (OPSCC) have been used, but the optimal approach is unknown.

MATERIALS/METHODS

Multi-institutional cohort study of 385 patients with previously untreated p16+ OPSCC undergoing definitive radiotherapy (RT) with or without systemic therapy between 2009-2020. Chemotherapy intensity was categorized as high (bolus cisplatin and/or induction chemotherapy), medium (weekly cisplatin), or low (non-cisplatin or RT alone). Standard favorable vs. unfavorable risk was defined using NRG HN005 eligibility criteria. High vs. low relative risk (RR) group was defined using the HNCIG omega score (≥ 0.80 vs. < 0.80), which quantifies the proportion of a patient's overall event risk due to cancer. We used multivariable ordinal logistic regression to estimate effects of age (yrs), sex, performance status (PS), Charlson comorbidity index (CCI), T/N (AJCC 8th), current smoking, and pack-years (> 10 vs. ≤ 10) on treatment allocation. Effects on relative event hazards were estimated using generalized competing event regression.

RESULTS

Median follow-up time was 44.2 months. Chemotherapy intensity was high in 206 (54%), medium in 108 (28%), and low in 71 (18%). 280 patients (73%) were unfavorable risk and 197 (51%) were high RR. 178 patients (46%) had discordant risk classification. On univariable analysis, significant predictors of higher intensity chemotherapy (normalized odds ratio (OR)) were CCI 0-1 (OR 1.49, 95% CI: 1.23-1.79), high omega score (OR 1.46; 1.20-1.77), decreased age (OR 1.43; 1.18-1.74), and PS 0 (OR 1.22; 1.01-1.48). Controlling for CCI, higher omega score was associated with significantly higher odds of intensive chemotherapy (OR 1.35; 1.10-1.65, but unfavorable risk (HN005 ineligibility) was not (OR 1.19; 0.98-1.44). Higher omega score was also associated with significantly higher RR for cancer recurrence (Rec) vs. competing mortality (CM) events (relative HR (rHR) 1.76; 1.12-2.75), but unfavorable risk was not (rHR 1.05; 0.63-1.75). Among patients receiving cisplatin, 50 favorable risk patients (58%) had high RR; all of their event risk was due to cancer recurrence (Table). The 110 unfavorable risk patients (48%) with low omega score had significantly lower RR for cancer events compared to the high omega score group (rHR 0.49; 0.29-0.84).

CONCLUSION

Many patients with favorable risk p16+ OPSCC have high relative risk for cancer events, which correlates with a benefit of intensive treatment. The HNCIG omega score is a strong predictor of allocation to intensive chemotherapy and may help identify candidates for deintensification.

Three induced pluripotent stem cell lines (TRNDi033-A, TRNDi034-A, TRNDi035-A) generated from lymphoblasts of three apparently healthy individuals

Expanded human lymphoblast cells from three different aged healthy individuals, 8-year-old male, 0-year-old newborn (NB) male, and 26-year-old female, were used to generate induced pluripotent stem cell (iPSC) lines TRNDi033-A, TRNDi034-A and TRNDi035-A, respectively, by exogenous expression of five reprogramming factors, human OCT4, SOX2, KLF4, L-MYC and LIN28. The authenticity of established iPSC lines was confirmed by the expressions of stem cell markers, karyotype analysis, embryoid body formation, and scorecard analysis. These iPSC lines could serve as healthy donor controls that are age and sex matched for the studies involving patient-specific iPSCs.

A Protocol for Culture and Characterization of Human Induced Pluripotent Stem Cells After Induction

Human induced pluripotent stem cells (hiPSCs) are characterized by unlimited self-renewal and the capability to differentiate into all three germ layers, with the potential to further differentiate into all types of cells and tissues. Human iPSCs retain all genetic information from their original donors and can be developed into disease models to study disease pathophysiology, identify disease phenotypes and biomarkers, and evaluate therapeutic efficacy and toxicity for drug development. Human iPSCs can also be used to develop cell therapies and regenerative medicine. In the last decade, the technologies for hiPSC generation and differentiation have advanced rapidly. Human iPSC culture and propagation are tedious and require careful handling. High-quality hiPSCs are necessary for downstream applications. The methods, techniques, and skills for hiPSC maintenance and characterization are very different from those for immortalized cell lines. It can be a challenge for new laboratory staff, and sometimes even for experienced staff, to properly culture and maintain the high quality of these cells. Here, we describe a comprehensive set of protocols for hiPSC propagation under chemically defined and feeder-free culture conditions. These step-by-step protocols describe in detail all the reagents and experimental procedures needed to culture hiPSCs. The protocols also describe experimental methods for hiPSC characterization, including immunofluorescence staining and flow cytometric analysis with a panel of pluripotency markers, a teratoma formation assay for validation of in vivo pluripotency, and detection of Sendai virus to ensure elimination of the viral vectors. These protocols have been successfully used in our laboratory for hiPSC expansion and propagation, and this article provide a useful reference guide for laboratory staff to work on hiPSC culture. Published 2023. This article is a U.S. Government work and is in the public domain in the USA. Current Protocols published by Wiley Periodicals LLC. Basic Protocol 1: Propagation and cryopreservation of hiPSC cultures Basic Protocol 2: Recovery of cryopreserved hiPSCs Basic Protocol 3: Validation of pluripotency markers via immunocytochemical analysis Alternate Protocol: Determination of the expression of pluripotency markers via flow cytometry analysis Basic Protocol 4: Assessment of pluripotency via in vivo teratoma formation assay Basic Protocol 5: Confirmation of Sendai viral vector clearance via RT-PCR.

Modulation of WNT, Activin/Nodal and MAPK Signaling Pathways Increases Arterial Hemogenic Endothelium and Hematopoietic Stem/Progenitor Cell Formation During Human iPSC Differentiation

Several differentiation protocols enable the emergence of hematopoietic stem and progenitor cells (HSPCs) from human induced pluripotent stem cells (iPSCs), yet optimized schemes to promote the development of HSPCs with self-renewal, multilineage differentiation and engraftment potential are lacking. To improve human iPSC differentiation methods, we modulated WNT, Activin/Nodal and MAPK signaling pathways by stage-specific addition of small molecule regulators CHIR99021, SB431542 and LY294002, respectively, and measured the impact on hematoendothelial formation in culture. Manipulation of these pathways provided a synergy sufficient to enhance formation of arterial hemogenic endothelium (HE) relative to control culture conditions. Importantly, this approach significantly increased production of human HSPCs with self-renewal and multilineage differentiation properties, as well as phenotypic and molecular evidence of progressive maturation in culture. Together, these findings provide a stepwise improvement in human iPSC differentiation protocols and offer a framework for manipulating intrinsic cellular cues to enable de novo generation of human HSPCs with functionality in vivo.

Self-organized yolk sac-like organoids allow for scalable generation of multipotent hematopoietic progenitor cells from induced pluripotent stem cells

Although the differentiation of human induced pluripotent stem cells (hiPSCs) into various types of blood cells has been well established, approaches for clinical-scale production of multipotent hematopoietic progenitor cells (HPCs) remain challenging. We found that hiPSCs cocultured with stromal cells as spheroids (hematopoietic spheroids [Hp-spheroids]) can grow in a stirred bioreactor and develop into yolk sac-like organoids without the addition of exogenous factors. Hp-spheroid-induced organoids recapitulated a yolk sac-characteristic cellular complement and structures as well as the functional ability to generate HPCs with lympho-myeloid potential. Moreover, sequential hemato-vascular ontogenesis could also be observed during organoid formation. We demonstrated that organoid-induced HPCs can be differentiated into erythroid cells, macrophages, and T lymphocytes with current maturation protocols. Notably, the Hp-spheroid system can be performed in an autologous and xeno-free manner, thereby improving the feasibility of bulk production of hiPSC-derived HPCs in clinical, therapeutic contexts.

Transcriptomic Analyses of Brains of RBM8A Conditional Knockout Mice at Different Developmental Stages Reveal Conserved Signaling Pathways Contributing to Neurodevelopmental Diseases

RNA-binding motif 8A (RBM8A) is a core component of the exon junction complex (EJC) that binds pre-mRNAs and regulates their splicing, transport, translation, and nonsense-mediated decay (NMD). Dysfunction in the core proteins has been linked to several detriments in brain development and neuropsychiatric diseases. To understand the functional role of Rbm8a in brain development, we have generated brain-specific Rbm8a knockout mice and used next-generation RNA-sequencing to identify differentially expressed genes (DEGs) in mice with heterozygous, conditional knockout (cKO) of Rbm8a in the brain at postnatal day 17 (P17) and at embryonic day 12. Additionally, we analyzed enriched gene clusters and signaling pathways within the DEGs. At the P17 time point, between the control and cKO mice, about 251 significant DEGs were identified. At E12, only 25 DEGs were identified in the hindbrain samples. Bioinformatics analyses have revealed many signaling pathways related to the central nervous system (CNS). When E12 and P17 results were compared, three DEGs, Spp1, Gpnmb, and Top2a, appeared to peak at different developmental time points in the Rbm8a cKO mice. Enrichment analyses suggested altered activity in pathways affecting cellular proliferation, differentiation, and survival. The results support the hypothesis that loss of Rbm8a causes decreased cellular proliferation, increased apoptosis, and early differentiation of neuronal subtypes, which may lead ultimately to an altered neuronal subtype composition in the brain.

Modulation of WNT, Activin/Nodal and MAPK Signaling Pathways Increases Arterial Hemogenic Endothelium and Hematopoietic Stem/Progenitor Cell Formation During Human iPSC Differentiation

Several differentiation protocols enable the emergence of hematopoietic stem and progenitor cells (HSPCs) from human induced pluripotent stem cells (iPSCs), yet optimized schemes to promote the development of HSPCs with self-renewal, multilineage differentiation and engraftment potential are lacking. To improve human iPSC differentiation methods, we modulated WNT, Activin/Nodal and MAPK signaling pathways by stage-specific addition of small molecule regulators CHIR99021, SB431542 and LY294002, respectively, and measured the impact on hematoendothelial formation in culture. Manipulation of these pathways provided a synergy sufficient to enhance formation of arterial hemogenic endothelium (HE) relative to control culture conditions. Importantly, this approach significantly increased production of human HSPCs with self-renewal and multilineage differentiation properties, as well as phenotypic and molecular evidence of progressive maturation in culture. Together, these findings provide a stepwise improvement in human iPSC differentiation protocols and offer a framework for manipulating intrinsic cellular cues to enable de novo generation of human HSPCs with functionality in vivo .

Significance Statement

The ability to produce functional HSPCs by differentiation of human iPSCs ex vivo holds enormous potential for cellular therapy of human blood disorders. However, obstacles still thwart translation of this approach to the clinic. In keeping with the prevailing arterial-specification model, we demonstrate that concurrent modulation of WNT, Activin/Nodal and MAPK signaling pathways by stage-specific addition of small molecules during human iPSC differentiation provides a synergy sufficient to promote arterialization of HE and production of HSPCs with features of definitive hematopoiesis. This simple differentiation scheme provides a unique tool for disease modeling, in vitro drug screening and eventual cell therapies.

The endo-lysosomal regulatory protein BLOC1S1 modulates hepatic lysosomal content and lysosomal lipolysis

BLOC1S1 is a common component of BLOC and BORC multiprotein complexes which play distinct roles in endosome and lysosome biology. Recent human mutations in BLOC1S1 associate with juvenile leukodystrophy. As leukodystrophy is linked to perturbed lysosomal lipid storage we explored whether BLOC1S1 itself modulates this biology. Given the central role of the liver in lipid storage, our investigations were performed in hepatocyte specific liver bloc1s1 knockout (LKO) mice and in human hepatocyte-like lines (HLCs) derived from inducible pluripotential stem cells (iPSCs) from a juvenile leukodystrophy subject's with bloc1s1 mutations and from isogenic corrected iPSCs. Here we show that hepatocyte lipid stores are diminished in parallel with increased lysosomal content, increased lysosomal lipid uptake and lipolysis in LKO mice. The lysosomal lipolysis program was independent of macro- and chaperone-mediated lipophagy but dependent on cellular lysosome content. In parallel, genetic induction of lysosomal biogenesis in a transformed hepatocyte cell line replicated depletion of intracellular lipid stores. Interestingly bloc1s1 mutant and isogenic corrected HLCs both showed normal lysosomal enzyme activity. However, relative to the isogenic corrected HLCs, mutant bloc1s1 HLCs showed reduced lysosomal content and increased lipid storage. Together these data show distinct phenotypes in human mutant HLCs compared to murine knockout cells. At the same time, human blcs1s1 mutation and murine hepatocyte bloc1s1 depletion disrupt lysosome content and the cellular lipid storage. These data support that BLOC1S1 modulates lysosome content and lipid handling independent of autophagy and show that lysosomal lipolysis is dependent on the cellular content of functional lysosomes.

Ligand-free mitochondria-localized mutant AR-induced cytotoxicity in spinal bulbar muscular atrophy

Spinal bulbar muscular atrophy (SBMA), the first identified CAG-repeat expansion disorder, is an X-linked neuromuscular disorder involving CAG-repeat-expansion mutations in the androgen receptor (AR) gene. We utilized CRISPR-Cas9 gene editing to engineer novel isogenic human induced pluripotent stem cell (hiPSC) models, consisting of isogenic AR knockout, control and disease lines expressing mutant AR with distinct repeat lengths, as well as control and disease lines expressing FLAG-tagged wild-type and mutant AR, respectively. Adapting a small-molecule cocktail-directed approach, we differentiate the isogenic hiPSC models into motor neuron-like cells with a highly enriched population to uncover cell-type-specific mechanisms underlying SBMA and to distinguish gain- from loss-of-function properties of mutant AR in disease motor neurons. We demonstrate that ligand-free mutant AR causes drastic mitochondrial dysfunction in neurites of differentiated disease motor neurons due to gain-of-function mechanisms and such cytotoxicity can be amplified upon ligand (androgens) treatment. We further show that aberrant interaction between ligand-free, mitochondria-localized mutant AR and F-ATP synthase is associated with compromised mitochondrial respiration and multiple other mitochondrial impairments. These findings counter the established notion that androgens are requisite for mutant AR-induced cytotoxicity in SBMA, reveal a compelling mechanistic link between ligand-free mutant AR, F-ATP synthase and mitochondrial dysfunction, and provide innovative insights into motor neuron-specific therapeutic interventions for SBMA.

A reference human induced pluripotent stem cell line for large-scale collaborative studies

Human induced pluripotent stem cell (iPSC) lines are a powerful tool for studying development and disease, but the considerable phenotypic variation between lines makes it challenging to replicate key findings and integrate data across research groups. To address this issue, we sub-cloned candidate human iPSC lines and deeply characterized their genetic properties using whole genome sequencing, their genomic stability upon CRISPR-Cas9-based gene editing, and their phenotypic properties including differentiation to commonly used cell types. These studies identified KOLF2.1J as an all-around well-performing iPSC line. We then shared KOLF2.1J with groups around the world who tested its performance in head-to-head comparisons with their own preferred iPSC lines across a diverse range of differentiation protocols and functional assays. On the strength of these findings, we have made KOLF2.1J and its gene-edited derivative clones readily accessible to promote the standardization required for large-scale collaborative science in the stem cell field.

Human induced pluripotent stem cells generated from a patient with a homozygous mutation in the Lyn kinase gene

We have successfully generated induced pluripotent stem cells (iPSC) from dermal fibroblasts of the patient with a germline mutation in the coding region of the LYN kinase gene. This gain of function (GOF) mutation eliminates the inhibitory tyrosine (Y) at the position p.Y508, with an unknown established disease etiology. The iPSC carrying germline mutation in LYN are phenotypically normal, and they have capacity to differentiate toward the three germ layers. These iPSCs are critical for studying this unknown disease etiology and to the further understand the role of Lyn kinases in autoimmune disease.

Assessment of mitophagy in human iPSC-derived cardiomyocytes

Defective mitophagy contributes to normal aging and various neurodegenerative and cardiovascular diseases. The newly developed methodologies to visualize and quantify mitophagy allow for additional progress in defining the pathophysiological significance of mitophagy in various model organisms. However, current knowledge regarding mitophagy relevant to human physiology is still limited. Model organisms such as mice might not be optimal models to recapitulate all the key aspects of human disease phenotypes. The development of the human-induced pluripotent stem cells (hiPSCs) may provide an exquisite approach to bridge the gap between animal mitophagy models and human physiology. To explore this premise, we take advantage of the pH-dependent fluorescent mitophagy reporter, mt-Keima, to assess mitophagy in hiPSCs and hiPSC-derived cardiomyocytes (hiPSC-CMs). We demonstrate that mt-Keima expression does not affect mitochondrial function or cardiomyocytes contractility. Comparison of hiPSCs and hiPSC-CMs during different stages of differentiation revealed significant variations in basal mitophagy. In addition, we have employed the mt-Keima hiPSC-CMs to analyze how mitophagy is altered under certain pathological conditions including treating the hiPSC-CMs with doxorubicin, a chemotherapeutic drug well known to cause life-threatening cardiotoxicity, and hypoxia that stimulates ischemia injury. We have further developed a chemical screening to identify compounds that modulate mitophagy in hiPSC-CMs. The ability to assess mitophagy in hiPSC-CMs suggests that the mt-Keima hiPSCs should be a valuable resource in determining the role mitophagy plays in human physiology and hiPSC-based disease models. The mt-Keima hiPSCs could prove a tremendous asset in the search for pharmacological interventions that promote mitophagy as a therapeutic target.Abbreviations: AAVS1: adeno-associated virus integration site 1; AKT/protein kinase B: AKT serine/threonine kinase; CAG promoter: cytomegalovirus early enhancer, chicken ACTB/β-actin promoter; CIS: cisplatin; CRISPR: clustered regularly interspaced short palindromic repeats; FACS: fluorescence-activated cell sorting; FCCP: carbonyl cyanide p-trifluoromethoxyphenylhydrazone; hiPSC: human induced pluripotent stem cell; hiPSC-CMs: human induced pluripotent stem cell-derived cardiomyocytes; ISO: isoproterenol; MAP1LC3/LC3: microtubule associated protein 1 light chain 3; MTOR: mechanistic target of rapamycin kinase; PI3K: phosphoinositide 3-kinase; PINK1: PTEN induced kinase 1; PRKN: parkin RBR E3 ubiquitin protein ligase; RT: room temperature; SB: SBI-0206965; ULK1: unc-51 like autophagy activating kinase 1.

Transcriptome dissection of candidate genes associated with lentil seed quality traits

Lentils provide a rich plant-based protein source and staple food in many parts of the world. Despite numerous nutritional benefits, lentil seeds also possess undesirable elements, such as anti-nutritional factors. Understanding the genetic networks of seed metabolism is of great importance for improving the seed nutritional profile. We applied RNA sequencing analysis to survey the transcriptome of developing lentil seeds and compared this with that of the pod shells and leaves. In total, we identified 2622 genes differentially expressed among the tissues examined. Genes preferentially expressed in seeds were enriched in the Gene Ontology (GO) terms associated with development, nitrogen and carbon (N/C) metabolism and lipid synthesis. We further categorized seed preferentially expressed genes based on their involvement in storage protein production, starch accumulation, lipid and suberin metabolism, phytate, saponin and phenylpropanoid biosynthesis. The availability of transcript profile datasets on lentil seed metabolism and a roadmap of candidate genes presented here will be of great value for breeding strategies towards further improvement of lentil seed quality traits.

Mucoadhesive Nucleoside-Based Hydrogel Delays Oral Leukoplakia Canceration

Some oral squamous cell carcinomas (OSCCs) originate from preexisting oral potentially malignant disorders (OPMDs). Oral leukoplakia (OLK) is the most common and typical OPMD in the clinic, so treatment for it is essential to reduce OSCC incidence. Local chemotherapy is an option other than surgery considering the superficial site of OLK. However, there are no standardized drugs applied to OLK, and traditionally used chemotherapeutic drugs revealed limited efficacy for lack of adhesion. Hence, there is a growing demand to prepare new agents that combine mucoadhesion with an anti-OLK effect. Here, an isoguanosine-tannic acid (isoG-TA) supramolecular hydrogel via dynamic borate esters was successfully fabricated based on isoG and TA. Previously reported guanosine-TA (G-TA) hydrogel was also explored for an anti-OLK effect. Both gels not only exhibited ideal adhesive properties but also integrated anti-OLK activities in one system. In vitro cell viability indicated that isoG and TA inhibited the proliferation of dysplastic oral keratinocytes (DOKs). The in vivo OLK model evidence revealed that both gels showed potential to prevent OLK canceration. In addition, the probable anti-DOK mechanisms of isoG and TA were investigated. The results indicated that isoG could bind to adenosine kinase (ADK) and then affected the mammalian target of rapamycin (mTOR) pathway to inhibit DOK proliferation. TA could significantly and continuously reduce reactive oxygen species (ROS) in DOKs through its antioxidant effect. ROS plays an important role in the progression of cell cycle. We proved that the low level of ROS may inhibit DOK proliferation by inducing G₀/G₁ arrest in the cell cycle. Altogether, this study innovatively fabricated an isoG-TA hydrogel with ideal adhesion, and both isoG and TA showed in vitro inhibition of DOKs. Moreover, both isoG-TA and G-TA hydrogels possessed potential in delaying the malignant transformation of OLK, and the G-TA hydrogel showed a better statistical effect, providing an effective strategy for controlling OLK.

Sympathetic Neurons Regulate Cardiomyocyte Maturation in Culture

Embryos devoid of autonomic innervation suffer sudden cardiac death. However, whether autonomic neurons have a role in heart development is poorly understood. To investigate if sympathetic neurons impact cardiomyocyte maturation, we co-cultured phenotypically immature cardiomyocytes derived from human induced pluripotent stem cells with mouse sympathetic ganglion neurons. We found that 1) multiple cardiac structure and ion channel genes related to cardiomyocyte maturation were up-regulated when co-cultured with sympathetic neurons; 2) sarcomere organization and connexin-43 gap junctions increased; 3) calcium imaging showed greater transient amplitudes. However, sarcomere spacing, relaxation time, and level of sarcoplasmic reticulum calcium did not show matured phenotypes. We further found that addition of endothelial and epicardial support cells did not enhance maturation to a greater extent beyond sympathetic neurons, while administration of isoproterenol alone was insufficient to induce changes in gene expression. These results demonstrate that sympathetic neurons have a significant and complex role in regulating cardiomyocyte development.

iPS-derived neural stem cells for disease modeling and evaluation of therapeutics for mucopolysaccharidosis type II

Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is a rare, lysosomal disorder caused by mutations in a gene encoding iduronate-2-sulfatase (IDS). IDS deficiency results in an accumulation of glycosaminoglycans (GAGs) and secondary accumulations of other lipids in lysosomes. Symptoms of MPS II include a variety of soft and hard tissue problems, developmental delay, and deterioration of multiple organs. Enzyme replacement therapy is an approved treatment for MPS II, but fails to improve neuronal symptoms. Cell-based neuronal models of MPS II disease are needed for compound screening and drug development for the treatment of the neuronal symptoms in MPS II. In this study, three induced pluripotent stem cell (iPSC) lines were generated from three MPS II patient-derived dermal fibroblast cell lines that were differentiated into neural stem cells and neurons. The disease phenotypes were measured using immunofluorescence staining and Nile red dye staining. In addition, the therapeutic effects of recombinant human IDS enzyme, delta-tocopherol (DT), and hydroxypropyl-beta-cyclodextrin (HPBCD) were determined in the MPS II disease cells. Finally, the neural stem cells from two of the MPS II iPSC lines exhibited typical disease features including a deficiency of IDS activity, abnormal glycosaminoglycan storage, and secondary lipid accumulation. Enzyme replacement therapy partially rescued the disease phenotypes in these cells. DT showed a significant effect in reducing the secondary accumulation of lipids in the MPS II neural stem cells. In contrast, HPBCD displayed limited or no effect in these cells. Our data indicate that these MPS II cells can be used as a cell-based disease model to study disease pathogenesis, evaluate drug efficacy, and screen compounds for drug development.

Safety, tolerability, and pharmacokinetics (PK) of treprostinil palmitil inhalation powder (TPIP): a phase 1, randomised, double-blind, single- and multiple-dose study

Background/Introduction

Use of treprostinil in the treatment of pulmonary arterial hypertension (PAH) is limited by a short half-life and dose-limiting adverse events. TPIP, a dry powder formulation of the treprostinil prodrug treprostinil palmitil, is under investigation for PAH. In preclinical models, TPIP provided sustained treprostinil release in the lung and demonstrated sustained reduction of pulmonary arterial pressures.

Purpose

To examine the safety, tolerability, and PK of single- and multiple-dose administration of once-daily (QD) TPIP in healthy volunteers.

Methods

In this phase 1 study, healthy adults (aged 18–45 years) were randomised to receive single or multiple QD inhalation doses of TPIP. Single-dose participants received TPIP 112.5, 225, 450, or 675 μg (n=6 per dose) or placebo (n=2). Multiple-dose participants received TPIP 225 μg QD for 7 days (n=6), 112.5 μg QD for 4 days followed by 225 μg QD for 3 days (n=6), or placebo for 7 days (n=4).

Results

Of 42 randomly assigned participants who received ≥1 dose, 41 (97.6%) completed the study. Of the single-dose TPIP–treated participants, 70.8% (n=17/24) experienced a treatment-emergent adverse event (TEAE) vs 0% (0/2) of placebo-treated participants; the most common TEAEs (≥15%) among TPIP-treated participants were cough (45.8%), dizziness (29.2%), throat irritation (20.8%), nausea (16.7%), and hypotension (16.7%). Of the multiple-dose TPIP–treated participants, 83.3% (n=10/12) experienced a TEAE vs 50.0% of placebo-treated participants (2/4); the most common TEAEs were cough (58.3% TPIP vs 50.0% placebo), headache (50.0% vs 0%), nausea (33.3% vs 0%), and dizziness (25.0% vs 0%). Overall, 69.0% of participants (29/42) experienced mild TEAEs and 16.7% (7/42) experienced moderate TEAEs; no severe or serious TEAEs occurred. TEAEs were more frequent with increasing TPIP doses. Participants titrated from TPIP 112.5 μg QD to 225 μg QD experienced fewer TEAEs than those who received 225 μg QD at treatment initiation; all TEAEs were mild. After single-dose TPIP treatment, treprostinil exposure was dose proportional, with mean (CV%) Cmax = 78.4–717 pg/mL (38.6-72.9%) and AUC(0–∞) = 1.09–5.48 h·ng/mL (11.5–30.0%). At steady-state (225 μg), the mean (CV%) of Cmax, Cmin, and AUC(0–t) were 193–228 pg/mL (32.9–46.4%), 17.6–22.8 ng/mL (43.7%-64.4%) and 1.68–1.82 ng·h/mL (28.7–36.6%), respectively. No steady-state accumulation was observed. Elimination t1/2 was 8.7–11.6 h after a single dose and 6.8–8.8 h at steady state. Plasma concentrations of treprostinil palmitil were below the limit of quantification (100 pg/mL) at all time points measured.

Conclusions

In this phase 1 study, single and multiple TPIP dosing was generally well tolerated in healthy volunteers, with a PK profile that supports QD dosing. TEAEs were dose related; most were mild, none were severe or serious, and a titration schedule improved tolerability. These results support further examination of TPIP in patients with PAH.

Funding Acknowledgement

Type of funding sources: Other. Main funding source(s): Insmed Incorporated

Generation of two gene corrected human isogenic iPSC lines (NCATS-CL6104 and NCATS-CL6105) from a patient line (NCATS-CL6103) carrying a homozygous p.R401X mutation in the NGLY1 gene using CRISPR/Cas9

NGLY1 deficiency is a rare recessive genetic disease caused by mutations in the NGLY1 gene which codes for N-glycanase 1 (NGLY1). Here, we report the generation of two gene corrected iPSC lines using a patient-derived iPSC line (NCATS-CL6103) that carried a homozygous p.R401X mutation in the NGLY1 gene. These lines contain either one (NCATS-CL6104) or two (NCATS-CL6105) CRISPR/Cas9 corrected alleles of NGLY1. This pair of NGLY1 mutation corrected iPSC lines can be used as a control for the NCATS-CL6103 which serves as a cell-based NGLY1 disease model for the study of the disease pathophysiology and evaluation of therapeutics under development.

[Effect of PPAR-γ agonist pioglitazone on the prolifeiration of malignant nesothelionma cells induced by HMGB1]

Objective: To investigate the effect and mechanism of PPAR-γ agonist Pioglitazone (PGZ) on the proliferation of malignant mesothelioma (MM) cells. Methods: In December 2019, MM cell lines MSTO-211H and NCI-H2452 were incubated with different final concentrations of PGZ (0, 10, 50, 100, 150, and 200 μmol/L) for different periods of time (24 h, 48 h, and 72 h) , and then the cell proliferation level was detected by CCK8 assay. After given various final concentration of PGZ (0, 10, 50, 100, 150, 200 μmol/L) the for 72 hours, the changes of number and morphology of MM cells were observed under an inverted microscope. The expressions of PPAR-γ and HMGB1 mRNA were determined by real-time fluorescence quantitative reverse transcription-polymerase chain reaction (qRT-PCR) after treatment of MM cells with PGZ of 0, 10, 50, 100 μmol/L for 72 h. The MM cells were treated with PGZ at concentration of 0, 100 μmol/L for 72 h, and the protein expressions of HMGB1 were examined using Western blotting and immunofluorescence; the protein expressions of Ki67 were assessed by immunohistochemistry. Results: The cell viability rate of MM cells was decreased after treated with PGZ (P<0.05) . Cell number in PGZ-treated group was significantly less than that in control group and morphology changes were observed under light microscope. QRT-PCR results revealed significantly increased PPAR-γ mRNA expression in the PGZ-treated group compared to the control group (P<0.05) . There was a significant decrease in the mRNA expression level of HMGB1 in the PGZ-treated group (100 μmol/L) as compared to the control group in MSTO-211H (P<0.05) ; however, the expression level of HMGB1 in NCI-H2452 was an increase or no significant differences (P>0.05) . Western blotting and immunofluorescence results showed that the protein expression of HMGB1 was reduced in the PGZ-treated group compared with the control group in MSTO-211H (P<0.05) , but the protein expression of that in NCI-H2452 was no significant differences (P>0.05) . Immunohistochemistry results showed increased expression of proliferation marker Ki-67. Conclusion: Pioglitazone suppresses the proliferation of MM cells through inhibition of HMGB1 by the activation of PPAR-γ.

Distinct Regionalization Patterns of Cortical Morphology are Associated with Cognitive Performance Across Different Domains

Cognitive performance in children is predictive of academic and social outcomes; therefore, understanding neurobiological mechanisms underlying individual differences in cognition during development may be important for improving quality of life. The belief that a single, psychological construct underlies many cognitive processes is pervasive throughout society. However, it is unclear if there is a consistent neural substrate underlying many cognitive processes. Here, we show that a distributed configuration of cortical surface area and apparent thickness, when controlling for global imaging measures, is differentially associated with cognitive performance on different types of tasks in a large sample (N = 10 145) of 9-11-year-old children from the Adolescent Brain and Cognitive DevelopmentSM (ABCD) study. The minimal overlap in these regionalization patterns of association has implications for competing theories about developing intellectual functions. Surprisingly, not controlling for sociodemographic factors increased the similarity between these regionalization patterns. This highlights the importance of understanding the shared variance between sociodemographic factors, cognition and brain structure, particularly with a population-based sample such as ABCD.

[Escherichia coli expressing gas vesicles is safe for enhancing the ablation effect of highintensity focused ultrasound in tumor-bearing mice]

OBJECTIVE

To investigate the effect and safety of Escherichia coli (E.coli) expressing gas vesicle (GVs) for enhancing the efficacy of tumor ablation by high intensity focused ultrasound (HIFU) in tumor-bearing mice.

OBJECTIVE

Thirty-two female BALB/c mice were used to establish mouse models bearing 4T1 tumor, which were randomized into GVs group [E.coli BL21 (AI)-PET28a-Arg1] and control group (PBS), and the efficacy of HIFU ablation was evaluated by examining coagulative necrotic volume and pathology of the tumors. Another 104 BALB/c mice were also randomly divided into GVs group and control group, and body weight changes of the mice were recorded on days 1, 4 and 15 after intravenous injection of E.coli containing GVs or PBS. White blood cells, red blood cells, hemoglobin and platelet counts and liver and renal function parameters of the mice were detected, and serum levels of TNF-α and IL-1β were examined using ELISA. The pathological changes in the liver and spleen were evaluated using HE staining to assess the safety of the treatments.

OBJECTIVE

HIFU ablation resulted in a significantly greater volume of coagulative necrosis and severer tissue damage in GVs group than in the control group (P < 0.001). In the 104 BALB/c mice without tumor cell inoculation, intravenous injection of E.coli expressing GVs, as compared with PBS, did not significantly affect body weight or cause changes in white blood cell, red blood cell and platelet counts or hemoglobin level (P1=0.59, P2=0.27, P3=0.76, P4=0.81). The liver and kidney function parameters (P1=0.12, P2=0.46, P3=0.62, P4=0.86) and serum levels of TNF-α and IL-1β (P1=0.48, P2=0.56) were all comparable between GVs group and control group. No obvious pathological changes were detected in the liver and spleen tissues in either GVs group or the control group.

OBJECTIVE

E.coli expressing GVs is safe for enhancing the ablation effect of HIFU in tumor-bearing mice.

Generation of an induced pluripotent stem cell line (TRNDi012-B) from Fibrodysplasia Ossificans Progressiva (FOP) patient carrying a heterozygous mutation c. 617G > A in the ACVR1 gene

Fibrodysplasia ossificans progressiva (FOP) is a rare autosomal dominant disorder of progressive ossification of skeletal muscle, fascia, tendons, and ligaments. Most FOP cases are caused by a heterozygous c. 617G > A mutation in the ACVR1 gene which encodes a gain-of-function of bone morphogenetic protein type I receptor. A human induced pluripotent stem cell (iPSC) line was generated from the dermal skin fibroblasts of a FOP patient who carries the c. 617G > A mutation in the ACVR1 gene. This iPSC line provides an attractive resource for FOP disease modeling.

Talbot-Lau x-ray deflectometer: Refraction-based HEDP imaging diagnostic

Talbot-Lau x-ray interferometry has been implemented to map electron density gradients in High Energy Density Physics (HEDP) experiments. X-ray backlighter targets have been evaluated for Talbot-Lau X-ray Deflectometry (TXD). Cu foils, wires, and sphere targets have been irradiated by 10-150 J, 8-30 ps laser pulses, while two pulsed-power generators (∼350 kA, 350 ns and ∼200 kA, 150 ns) have driven Cu wire, hybrid, and laser-cut x-pinches. A plasma ablation front generated by the Omega EP laser was imaged for the first time through TXD for densities >10²³ cm^-3. Backlighter optimization in combination with x-ray CCD, image plates, and x-ray film has been assessed in terms of spatial resolution and interferometer contrast for accurate plasma characterization through TXD in pulsed-power and high-intensity laser environments. The results obtained thus far demonstrate the potential of TXD as a powerful diagnostic for HEDP.

An induced pluripotent stem cell line (NCATS-CL9075) from a patient carrying compound heterozygote mutations, p.R390P and p.L318P, in the NGLY1 gene

NGLY1 deficiency is a rare disorder caused by mutations in the NGLY1 gene which codes for the highly conserved N-glycanase1 (NGLY1). This enzyme functions in cytosolic deglycosylation of N-linked glycoproteins. An induced pluripotent stem cell (iPSC) line was generated from the dermal fibroblasts of a 2-year-old patient carrying compound heterozygous mutations, p.R390P and p.L318P in the NGLY1 gene. This cell-based iPSC disease model provides a resource to study disease pathophysiology and to develop a cell-based disease model for drug development for NGLY1 patients.

Generation of an induced pluripotent stem cell line (TRNDi030-A) from a patient with Farber disease carrying a homozygous p. Y36C (c. 107 A>G) mutation in ASAH1

Farber disease is an ultra-rare lysosomal storage disease. Mutations in the N-acylsphingosine amidohydrolase (ASAH1) gene, which encodes for the enzyme acid ceramidase (ACDase), cause ceramides to accumulate in the body. A human induced pluripotent stem cell (iPSC) line TRNDi030-A was generated from fibroblasts of a male patient with a homozygous p. Y36C (c.107 A>G) variant in the second exon of the ASAH1 producing the alpha subunit of ACDase. This Farber disease iPSC line is a useful resource to study disease pathophysiology and to develop therapeutics for treatment of patients with Farber disease.

Generation of Alagille syndrome derived induced pluripotent stem cell line carrying heterozygous mutation in the JAGGED-1 gene at splicing site (Chr20: 10,629,709C>A) before exon 11

Alagille syndrome (ALGS) is a multisystem autosomal dominant disorder caused by defects in the Notch signaling pathway, including the mutation in JAGGED1 (JAG1) (ALGS type 1) or NOTCH2 (ALGS type 2). An induced pluripotent stem cell (iPSC) line was generated from the dermal fibroblasts of a 3-month-old patient with heterozygous mutation at JAG1 splicing site (Chr20: 10,629,709C>A) before exon 11. This iPSC model offers a useful resource for disease modeling to study the disease pathophysiology and to develop therapeutics for treatment of ALGS.

Eltrombopag Improves Erythroid Differentiation in a Human Induced Pluripotent Stem Cell Model of Diamond Blackfan Anemia

Diamond Blackfan Anemia (DBA) is a congenital macrocytic anemia associated with ribosomal protein haploinsufficiency. Ribosomal dysfunction delays globin synthesis, resulting in excess toxic free heme in erythroid progenitors, early differentiation arrest, and pure red cell aplasia. In this study, DBA induced pluripotent stem cell (iPSC) lines were generated from blood mononuclear cells of DBA patients with inactivating mutations in RPS19 and subjected to hematopoietic differentiation to model disease phenotypes. In vitro differentiated hematopoietic cells were used to investigate whether eltrombopag, an FDA-approved mimetic of thrombopoietin with robust intracellular iron chelating properties, could rescue erythropoiesis in DBA by restricting the labile iron pool (LIP) derived from excessive free heme. DBA iPSCs exhibited RPS19 haploinsufficiency, reduction in the 40S/60S ribosomal subunit ratio and early erythroid differentiation arrest in the absence of eltrombopag, compared to control isogenic iPSCs established by CRISPR/Cas9-mediated correction of the RPS19 point mutation. Notably, differentiation of DBA iPSCs in the presence of eltrombopag markedly improved erythroid maturation. Consistent with a molecular mechanism based on intracellular iron chelation, we observed that deferasirox, a clinically licensed iron chelator able to permeate into cells, also enhanced erythropoiesis in our DBA iPSC model. In contrast, erythroid maturation did not improve substantially in DBA iPSC differentiation cultures supplemented with deferoxamine, a clinically available iron chelator that poorly accesses LIP within cellular compartments. These findings identify eltrombopag as a promising new therapeutic to improve anemia in DBA.

Transcriptional Programming of Human Mechanosensory Neuron Subtypes from Pluripotent Stem Cells

Efficient and homogeneous in vitro generation of peripheral sensory neurons may provide a framework for novel drug screening platforms and disease models of touch and pain. We discover that, by ovesssrexpressing NGN2 and BRN3A, human pluripotent stem cells can be transcriptionally programmed to differentiate into a surprisingly uniform culture of cold- and mechano-sensing neurons. Although such a neuronal subtype is not found in mice, we identify molecular evidence for its existence in human sensory ganglia. Combining NGN2 and BRN3A programming with neural crest patterning, we produce two additional populations of sensory neurons, including a specialized touch receptor neuron subtype. Finally, we apply this system to model a rare inherited sensory disorder of touch and proprioception caused by inactivating mutations in PIEZO2. Together, these findings establish an approach to specify distinct sensory neuron subtypes in vitro, underscoring the utility of stem cell technology to capture human-specific features of physiology and disease.

Nickolls et al. develop a method, using human stem cells, to generate specific types of sensory neurons that detect cold temperature and mechanical force. This approach uncovers a class of neuron found in humans, but not mice, and enables the modeling of a rare sensory disorder of touch and proprioception.

[Estimation of Early Postmortem Interval of Asphyxial Death Rats at Different Ambient Temperatures by GC-MS-Based Metabolomics]

Abstract

Objective To establish the orthogonal partial least square （OPLS） model for the estimation of early postmortem interval （PMI） of asphyxial death rats in four ambient temperatures based on gas chromatography-mass spectrometry （GC-MS） metabolomics. Methods The 96 rats were divided into four temperature groups （5 ℃, 15 ℃, 25 ℃ and 35 ℃）. Each temperature group was further divided into 3 h, 6 h, 12 h and 24 h after death, and 6 other rats were taken as the control group. The cardiac blood was collected at the set time points for the four temperature groups and 0 h after death for the control group for the metabolomics analysis by GC-MS. By OPLS analysis, the variable importance in projection （VIP）>1 and the result of Kruskal-Wallis test P<0.001 were used to screen out the differential metabolite related to PMIs in the cardiac blood of rats of different temperature groups. Then OPLS regression models of different temperature groups were established with these metabolites. At the same time, a prediction group for investigating the prediction ability of these models was set up. Results Through the analysis of OPLS, 18, 15, 24 and 30 differential metabolites （including organic acids, amino acids, sugars and lipids） were screened out from the rats in groups of 5 ℃, 15 ℃, 25 ℃ and 35 ℃, respectively. The prediction results of the four temperature group models showed that the prediction deviation of 5 ℃ model was larger than that of other groups. The prediction results of other temperature groups were satisfactory. Conclusion There are some differences in the changes of metabolites in cardiac blood of rats at different ambient temperatures. The influence of ambient temperature should be investigated in the study of PMI estimation by metabolomics, which may improve the accuracy of PMI estimation.

Luteoloside Ameliorates Palmitic Acid-Induced in Vitro Model of Non-alcoholic Fatty Liver Disease via Activating STAT3-Triggered Hepatocyte Regeneration

Luteoloside (Lute), a bioactive natural ingredient, widely exists in nature and possesses hepatoprotective and hepatocyte proliferation-promoting properties. This study aimed to investigate whether Lute could counteract non-alcoholic fatty liver disease (NAFLD)-caused hepatocyte damage via its stimulation of hepatocyte regeneration efficacy and to explore the involved mechanism. LO2 cells and primary hepatocytes were used to examine the hepatocyte proliferation effects of Lute under physiological conditions and in the palmitic acid (PA)- induced in vitro model of NAFLD. STAT3 and cell cycle-related proteins (cyclin D1, c-myc and p21) were evaluated by Western blot. Under physiological conditions, LO2 cells and primary hepatocytes treated with various concentration of Lute for 12 and 24 h showed increased hepatocyte proliferation, especially with 20 μM treatment for 24 h. More notably, under the model conditions, co-incubation with 20 μM of Lute also markedly reversed PA-induced inhibition of cell proliferation and viability in primary hepatocytes. Mechanistically, Lute could activate STAT3 and subsequently increase cyclin D1 and cmyc expression, which positively regulates cell cycle progression, and decrease expression of p21, an inhibitor of cell cycle progression. Furthermore, Luteinduced hepatocyte proliferation-promoting efficacy was abolished by STAT3 inhibitor stattic. Collectively, Lute can alleviate PA-induced hepatocyte damage via activating STAT3-mediated hepatocyte regeneration.