Histone acetyltransferase KAT2A modulates neural stem cell differentiation and proliferation by inducing degradation of the transcription factor PAX6.

Neural stem cells (NSCs) proliferation and differentiation rely on proper expression and posttranslational modification of transcription factors involved in the determination of cell fate. Further characterization is needed to connect modifying enzymes with their transcription factor substrates in the regulation of these processes. Here, we demonstrated that the inhibition of KAT2A, a histone acetyltransferase, leads to a phenotype of small eyes in the developing embryo of zebrafish, which is associated with enhanced proliferation and apoptosis of NSCs in zebrafish eyes. We confirmed that this phenotype is mediated by the elevated level of PAX6 protein. We further verified that KAT2A negatively regulates PAX6 at the protein level in cultured neural stem cells of rat cerebral cortex. We revealed that PAX6 is a novel acetylation substrate of KAT2A and the acetylation of PAX6 promotes its ubiquitination mediated by the E3 ligase RNF8 that facilitated PAX6 degradation. Our study proposes that KAT2A inhibition results in accelerated proliferation, delayed differentiation, or apoptosis, depending on the context of PAX6 dosage. Thus, the KAT2A/PAX6 axis plays an essential role to keep a balance between the self-renewal and differentiation of NSCs.

Thrombospondin 1 enhances systemic inflammation and disease severity in acute-on-chronic liver failure.

BACKGROUND: The key role of thrombospondin 1 (THBS1) in the pathogenesis of acute-on-chronic liver failure (ACLF) is unclear. Here, we present a transcriptome approach to evaluate THBS1 as a potential biomarker in ACLF disease pathogenesis. METHODS: Biobanked peripheral blood mononuclear cells (PBMCs) from 330 subjects with hepatitis B virus (HBV)-related etiologies, including HBV-ACLF, liver cirrhosis (LC), and chronic hepatitis B (CHB), and normal controls (NC) randomly selected from the Chinese Group on the Study of Severe Hepatitis B (COSSH) prospective multicenter cohort underwent transcriptome analyses (ACLF = 20; LC = 10; CHB = 10; NC = 15); the findings were externally validated in participants from COSSH cohort, an ACLF rat model and hepatocyte-specific THBS1 knockout mice. RESULTS: THBS1 was the top significantly differentially expressed gene in the PBMC transcriptome, with the most significant upregulation in ACLF, and quantitative polymerase chain reaction (ACLF = 110; LC = 60; CHB = 60; NC = 45) was used to verify that THBS1 expression corresponded to ACLF disease severity outcome, including inflammation and hepatocellular apoptosis. THBS1 showed good predictive ability for ACLF short-term mortality, with an area under the receiver operating characteristic curve (AUROC) of 0.8438 and 0.7778 at 28 and 90 days, respectively. Enzyme-linked immunosorbent assay validation of the plasma THBS1 using an expanded COSSH cohort subjects (ACLF = 198; LC = 50; CHB = 50; NC = 50) showed significant correlation between THBS1 with ALT and γ-GT (P = 0.01), and offered a similarly good prognostication predictive ability (AUROC = 0.7445 and 0.7175) at 28 and 90 days, respectively. ACLF patients with high-risk short-term mortality were identified based on plasma THBS1 optimal cut-off value (< 28 µg/ml). External validation in ACLF rat serum and livers confirmed the functional association between THBS1, the immune response and hepatocellular apoptosis. Hepatocyte-specific THBS1 knockout improved mouse survival, significantly repressed major inflammatory cytokines, enhanced the expression of several anti-inflammatory mediators and impeded hepatocellular apoptosis. CONCLUSIONS: THBS1 might be an ACLF disease development-related biomarker, promoting inflammatory responses and hepatocellular apoptosis, that could provide clinicians with a new molecular target for improving diagnostic and therapeutic strategies.

Adaptive phase I-II clinical trial designs identifying optimal biological doses for targeted agents and immunotherapies.

Targeted agents and immunotherapies have revolutionized cancer treatment, offering promising options for various cancer types. Unlike traditional therapies the principle of "more is better" is not always applicable to these new therapies due to their unique biomedical mechanisms. As a result, various phase I-II clinical trial designs have been proposed to identify the optimal biological dose that maximizes the therapeutic effect of targeted therapies and immunotherapies by jointly monitoring both efficacy and toxicity outcomes. This review article examines several innovative phase I-II clinical trial designs that utilize accumulated efficacy and toxicity outcomes to adaptively determine doses for subsequent patients and identify the optimal biological dose, maximizing the overall therapeutic effect. Specifically, we highlight three categories of phase I-II designs: efficacy-driven, utility-based, and designs incorporating multiple efficacy endpoints. For each design, we review the dose-outcome model, the definition of the optimal biological dose, the dose-finding algorithm, and the software for trial implementation. To illustrate the concepts, we also present two real phase I-II trial examples utilizing the EffTox and ISO designs. Finally, we provide a classification tree to summarize the designs discussed in this article.

Tracking the Role of Defect Types in Co3O4 Structural Evolution and Active Motifs during Oxygen Evolution Reaction.

Dynamic reconstruction of catalyst active sites is particularly important for metal oxide-catalyzed oxygen evolution reaction (OER). However, the mechanism of how vacancy-induced reconstruction aids OER remains ambiguous. Here, we use Co3O4 with Co or O vacancies to uncover the effects of different defects in the reconstruction process and the active motifs relevant to alkaline OER. Combining in situ characterization and theoretical calculations, we found that cobalt oxides are converted to an amorphous [Co(OH)6] intermediate state, and then the mismatched rates of *OH adsorption and deprotonation lead to irreversible catalyst reconstruction. The stronger *OH adsorption but weaker deprotonation induced by O defects provides the driving force for reconstruction, while Co defects favor dehydrogenation and reduce the reconstruction rate. Importantly, both O and Co defects trigger highly OER-active bridge Co sites in reconstructed catalysts, of which Co defects induce a short Co-Co distance (3.38 Å) under compressive lattice stress and show the best OER activity (η10 of 262 mV), superior to reconstructed oxygen-defected Co3O4-VO (η10 of 300 mV) and defect-free Co3O4 (η10 of 320 mV). This work highlights that engineering defect-dependent reconstruction may provide a rational route for electrocatalyst design in energy-related applications.

The activation of gastric inhibitory peptide/gastric inhibitory peptide receptor axis via sonic hedgehog signaling promotes the bridging of gapped nerves in sciatic nerve injury.

Schwann cells play an essential role in peripheral nerve regeneration by generating a favorable microenvironment. Gastric inhibitory peptide/gastric inhibitory peptide receptor (GIP/GIPR) axis deficiency leads to failure of sciatic nerve repair. However, the underlying mechanism remains elusive. In this study, we surprisingly found that GIP treatment significantly enhances the migration of Schwann cells and the formation of Schwann cell cords during recovery from sciatic nerve injury in rats. We further revealed that GIP and GIPR levels in Schwann cells were low under normal conditions, and significantly increased after injury demonstrated by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western blot. Wound healing and Transwell assays showed that GIP stimulation and GIPR silencing could affect Schwann cell migration. In vitro and in vivo mechanistic studies based on interference experiment revealed that GIP/GIPR might promote mechanistic target of rapamycin complex 2 (mTORC2) activity, thus facilitating cell migration; Rap1 activation might be involved in this process. Finally, we retrieved the stimulatory factors responsible for GIPR induction after injury. The results indicate that sonic hedgehog (SHH) is a potential candidate whose expression increased upon injury. Luciferase and chromatin immunoprecipitation (ChIP) assays showed that Gli3, the target transcription factor of the SHH pathway, dramatically augmented GIPR expression. Additionally, in vivo inhibition of SHH could effectively reduce GIPR expression after sciatic nerve injury. Collectively, our study reveals the importance of GIP/GIPR signaling in Schwann cell migration, providing a therapeutic avenue toward peripheral nerve injury.

Predicting the Onset of Hepatitis B Virus-Related Acute-on-Chronic Liver Failure.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is a life-threatening syndrome with rapid progression. This study aimed to develop and validate a prognostic score to predict the onset of ACLF in hepatitis B virus (HBV) etiology. METHODS: The prospective clinical data of 1373 patients with acute deterioration of HBV-related chronic liver disease were used to identify clinical characteristics and develop a prognostic score for the onset of ACLF. RESULTS: Of the patients assessed using the Chinese Group on the Study of Severe Hepatitis B (COSSH)-ACLF criteria, 903 patients with non-ACLF at admission (1 received transplantation at 5 days) were stratified: 71 with progression to ACLF and 831 without progression to ACLF at 7 days. Four predictors (total bilirubin, international normalized ratio, alanine aminotransferase, and ferritin) were associated significantly with ACLF onset at 7 days. The COSSH-onset-ACLF score was constituted as follows: (0.101 × ln [alanine aminotransferase] + 0.819 × ln [total bilirubin] + 2.820 × ln [international normalized ratio] + 0.016 × ln [ferritin]). The C-indexes of the new score for 7-/14-/28-day onset (0.928/0.925/0.913) were significantly higher than those of 5 other scores (Chronic Liver Failure Consortium ACLF development score/Model for End-stage Liver Disease score/Model for End-stage Liver Disease sodium score/COSSH-ACLF score/Chronic liver failure Consortium ACLF score; all P < .001). The improvement in predictive errors, time-dependent receiver operating characteristic, probability density function evaluation, and calibration curves of the new score showed the highest predictive value for ACLF onset at 7/14/28 days. Risk stratification of the new score showed 2 strata with high and low risk (≥6.3/<6.3) of ACLF onset. The external validation group further confirmed the earlier results. CONCLUSIONS: A new prognostic score based on 4 predictors can accurately predict the 7-/14-/28-day onset of ACLF in patients with acute deterioration of HBV-related chronic liver disease and might be used to guide clinical management.

ETS2 alleviates acute-on-chronic liver failure by suppressing excessive inflammation.

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a syndrome with high short-term mortality. The mechanism of the transcription factor ETS2 in ACLF remains unclear. This study aimed to clarify the molecular basis of ETS2 in ACLF pathogenesis. Peripheral blood mononuclear cells from patients with HBV-ACLF (n = 50) were subjected to RNA sequencing. Transcriptome analysis showed that ETS2 expression was significantly higher in ACLF patients than in patients with chronic liver diseases and healthy subjects (all p < 0.001). Area-under-ROC analysis of ETS2 demonstrated high values for the prediction of 28-/90-day mortality in ACLF patients (0.908/0.773). Significantly upregulated signatures of the innate immune response (monocytes/neutrophils/inflammation-related pathways) were observed in ACLF patients with high ETS2 expression. Myeloid-specific ETS2 deficiency in liver failure mice resulted in deterioration of biofunctions and increased expression of pro-inflammatory cytokines (IL-6/IL-1ß/TNF-α). Knockout of ETS2 in macrophages confirmed the downregulation of IL-6 and IL-1ß caused by both HMGB1 and lipopolysaccharide, and an NF-κB inhibitor reversed the suppressive effect of ETS2. ETS2 is a potential prognostic biomarker of ACLF patients that alleviates liver failure by downregulating the HMGB1-/lipopolysaccharide-triggered inflammatory response and may serve as a therapeutic target for ACLF.

Transcriptomics confirm the establishment of a liver-immune dual-humanized mouse model after transplantation of a single type of human bone marrow mesenchymal stem cell.

BACKGROUND AND AIMS: Human bone marrow mesenchymal stem cells (hBMSCs) are important for developing a dual-humanized mouse model to clarify disease pathogenesis. We aimed to elucidate the characteristics of hBMSC transdifferentiation into liver and immune cells. METHODS: A single type of hBMSCs was transplanted into immunodeficient Fah-/- Rag2-/- IL-2Rγc-/- SCID (FRGS) mice with fulminant hepatic failure (FHF). Liver transcriptional data from the hBMSC-transplanted mice were analysed to identify transdifferentiation with traces of liver and immune chimerism. RESULTS: Mice with FHF were rescued by implanted hBMSCs. Human albumin/leukocyte antigen (HLA) and CD45/HLA double-positive hepatocytes and immune cells were observed in the rescued mice during the initial 3 days. The transcriptomics analysis of liver tissues from dual-humanized mice identified two transdifferentiation phases (cellular proliferation at 1-5 days and cellular differentiation/maturation at 5-14 days) and ten cell lineages transdifferentiated from hBMSCs: human hepatocytes, cholangiocytes, stellate cells, myofibroblasts, endothelial cells and immune cells (T/B/NK/NKT/Kupffer cells). Two biological processes, hepatic metabolism and liver regeneration, were characterized in the first phase, and two additional biological processes, immune cell growth and extracellular matrix (ECM) regulation, were observed in the second phase. Immunohistochemistry verified that the ten hBMSC-derived liver and immune cells were present in the livers of dual-humanized mice. CONCLUSIONS: A syngeneic liver-immune dual-humanized mouse model was developed by transplanting a single type of hBMSC. Four biological processes linked to the transdifferentiation and biological functions of ten human liver and immune cell lineages were identified, which may help to elucidate the molecular basis of this dual-humanized mouse model for further clarifying disease pathogenesis.

DROID: dose-ranging approach to optimizing dose in oncology drug development.

In the era of targeted therapy, there has been increasing concern about the development of oncology drugs based on the "more is better" paradigm, developed decades ago for chemotherapy. Recently, the US Food and Drug Administration (FDA) initiated Project Optimus to reform the dose optimization and dose selection paradigm in oncology drug development. To accommodate this paradigm shifting, we propose a dose-ranging approach to optimizing dose (DROID) for oncology trials with targeted drugs. DROID leverages the well-established dose-ranging study framework, which has been routinely used to develop non-oncology drugs for decades, and bridges it with established oncology dose-finding designs to optimize the dose of oncology drugs. DROID consists of two seamlessly connected stages. In the first stage, patients are sequentially enrolled and adaptively assigned to investigational doses to establish the therapeutic dose range (TDR), defined as the range of doses with acceptable toxicity and efficacy profiles, and the recommended phase 2 dose set (RP2S). In the second stage, patients are randomized to the doses in RP2S to assess the dose-response relationship and identify the optimal dose. The simulation study shows that DROID substantially outperforms the conventional approach, providing a new paradigm to efficiently optimize the dose of targeted oncology drugs. DROID aligns with the approach of a randomized, parallel dose-response trial design recommended by the FDA in the Guidance on Optimizing the Dosage of Human Prescription Drugs and Biological Products for the Treatment of Oncologic Diseases.

Effects of nitrification and urease inhibitors on ammonia-oxidizing microorganisms, denitrifying bacteria, and greenhouse gas emissions in greenhouse vegetable fields.

Soil microorganisms and N cycling are important components of biogeochemical cycling processes. In addition, the study of the effects of nitrification and urease inhibitors on N and microorganisms in greenhouse vegetable fields is essential to reducing N loss and greenhouse gas emissions. The effects of nitrification inhibitors [2-chloro-6-(trichloromethyl) pyridine (CP), dicyandiamide (DCD)], and urease inhibitor [N-(n-butyl) thiophosphoric triamide (NBPT)] on soil inorganic N (NH4+-N, NO2--N and NO3--N) concentrations and the production rates of greenhouse gases (N2O, CH4, and CO2) in greenhouse vegetable fields were investigated via indoor incubation experiments. Polymerase chain reaction amplification and high-throughput sequencing technology (Illumina Miseq) were used to explore the community structure and abundance changes of ammonia-oxidizing archaea (AOA), ammonia-oxidizing bacteria (AOB), and denitrifying bacteria (nirK and nirS). The results showed that CP and DCD obviously inhibited NH4+-N conversion, and NO2--N, and NO3--N accumulation, NBPT slowed down urea hydrolysis and NH4+-N production, and the apparent nitrification rates of soil were in the following order: NBPT > DCD > DCD + NBPT > CP + NBPT > CP. Compared with urea treatment, the peak N2O production rate of inhibitor treatment decreased by 73.30-99.30%, and the production rate of CH4 and CO2 decreased by more than 66.16%. DCD and CP reduced the abundance of AOA and AOB, respectively. Furthermore, NBPT hindered the growth of ammonia-oxidizing microorganisms and nirS-type denitrifying bacteria, and urea and nitrification inhibitors were detrimental to the growth of Ensifer and Sinorhizobium in the nirK community. Nitrification and urease inhibitors can effectively slow down nitrification and greenhouse gas emissions, reduce N loss and improve soil quality by inhibiting the growth of ammonia-oxidizing microorganisms and denitrifying bacteria.

A Bayesian phase I/II design to determine subgroup-specific optimal dose for immunotherapy sequentially combined with radiotherapy.

Sequential administration of immunotherapy following radiotherapy (immunoRT) has attracted much attention in cancer research. Due to its unique feature that radiotherapy upregulates the expression of a predictive biomarker for immunotherapy, novel clinical trial designs are needed for immunoRT to identify patient subgroups and the optimal dose for each subgroup. In this article, we propose a Bayesian phase I/II design for immunotherapy administered after standard-dose radiotherapy for this purpose. We construct a latent subgroup membership variable and model it as a function of the baseline and pre-post radiotherapy change in the predictive biomarker measurements. Conditional on the latent subgroup membership of each patient, we jointly model the continuous immune response and the binary efficacy outcome using plateau models, and model toxicity using the equivalent toxicity score approach to account for toxicity grades. During the trial, based on accumulating data, we continuously update model estimates and adaptively randomize patients to admissible doses. Simulation studies and an illustrative trial application show that our design has good operating characteristics in terms of identifying both patient subgroups and the optimal dose for each subgroup.

Biomarker-based precision dose finding for immunotherapy combined with radiotherapy.

Recent success of sequential administration of immunotherapy following radiotherapy (RT), often referred to as immunoRT, has sparked the urgent need for novel clinical trial designs to accommodate the unique features of immunoRT. For this purpose, we propose a Bayesian phase I/II design for immunotherapy administered after standard-dose RT to identify the optimal dose that is personalized for each patient according to his/her measurements of PD-L1 expression at baseline and post-RT. We model the immune response, toxicity, and efficacy as functions of dose and patient's baseline and post-RT PD-L1 expression profile. We quantify the desirability of the dose using a utility function and propose a two-stage dose-finding algorithm to find the personalized optimal dose. Simulation studies show that our proposed design has good operating characteristics, with a high probability of identifying the personalized optimal dose.

Characteristics and health risk assessment of heavy metal pollution in atmospheric particulate matter in different regions of the Yellow River Delta in China.

To understand the characteristics, temporal and spatial variation, and health risks of atmospheric heavy metal pollution in different areas of the YRD (Yellow River Delta), atmospheric particles samples were collected in the YRD in China during 2016-2017. A total of 10 monitoring points were chosen in different areas (industrial parks, main urban areas, and rural areas) in the YRD, heavy metals were monitored using atomic fluorescence spectrometry and graphite furnace atomic absorption spectrometry. The results showed that TSP (total suspended particulate), PM10 (particulate matter with an aerodynamic diameter less than 10 µm), and PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm) contents were higher in the Kenli EDZ (economic development zone) and Kenli urban areas than those in other points. The concentration range of heavy metals in atmospheric samples at 10 points was different, with a difference of five orders of magnitude, of which the content of copper (Cu) was the highest, with the highest concentration of 4.375 µg/m3, and the content of particulate mercury (Hg) was the lowest, with the minimum concentration of 0.00001 µg/m3. Among the nine heavy metals, the contents of cadmium (Cd), lead (Pb), and Hg were higher in winter than in summer, and chromium (Cr), nickel (Ni), Cu, and manganese (Mn) were higher in summer than in winter. In addition to Hg, the contents of the other eight heavy metals in particulate matter showed a trend that urban areas and EDZs had higher concentrations than cities and towns and nature reserves, which can be attributed to industrial activities and coal-fired fuel emissions. Health risk assessment was carried out for adults and children, respectively, and the results showed that carcinogens have no obvious carcinogenic risk, but As and Cr have major potential carcinogenic risk. Among the noncarcinogenic substances, Mn has the greatest noncarcinogenic risk, and urban areas and economic development zones have the greatest risk. This study investigated the characteristics and health risk assessment of atmospheric heavy metal pollution in different areas in the YRD to supplement the research contents of atmospheric particulate heavy metals in the YRD in domestics and overseas. It is also critical to study the pollution and migration of heavy metals in China.

PBMC transcriptomics identifies immune-metabolism disorder during the development of HBV-ACLF.

OBJECTIVE: Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) pathophysiology remains unclear. This study aims to characterise the molecular basis of HBV-ACLF using transcriptomics. METHODS: Four hundred subjects with HBV-ACLF, acute-on-chronic hepatic dysfunction (ACHD), liver cirrhosis (LC) or chronic hepatitis B (CHB) and normal controls (NC) from a prospective multicentre cohort were studied, and 65 subjects (ACLF, 20; ACHD, 10; LC, 10; CHB, 10; NC, 15) among them underwent mRNA sequencing using peripheral blood mononuclear cells (PBMCs). RESULTS: The functional synergy analysis focusing on seven bioprocesses related to the PBMC response and the top 500 differentially expressed genes (DEGs) showed that viral processes were associated with all disease stages. Immune dysregulation, as the most prominent change and disorder triggered by HBV exacerbation, drove CHB or LC to ACHD and ACLF. Metabolic disruption was significant in ACHD and severe in ACLF. The analysis of 62 overlapping DEGs further linked the HBV-based immune-metabolism disorder to ACLF progression. The signatures of interferon-related, neutrophil-related and monocyte-related pathways related to the innate immune response were significantly upregulated. Signatures linked to the adaptive immune response were downregulated. Disruptions of lipid and fatty acid metabolism were observed during ACLF development. External validation of four DEGs underlying the aforementioned molecular mechanism in patients and experimental rats confirmed their specificity and potential as biomarkers for HBV-ACLF pathogenesis. CONCLUSIONS: This study highlights immune-metabolism disorder triggered by HBV exacerbation as a potential mechanism of HBV-ACLF and may indicate a novel diagnostic and treatment target to reduce HBV-ACLF-related mortality.

L-leucine promotes axonal outgrowth and regeneration via mTOR activation.

Discovering safe and effective drugs that promote neuron regeneration is an essential strategy for the recovery of central nervous system injuries. In this study, we found that L-leucine, an essential amino acid obtained from both supplements and food sources, could dramatically boost axonal outgrowth and regeneration. First, the effects of L-leucine on neurons were evaluated by cell apoptosis, survival, and death assays, and the results showed no changes in these processes after treatment. By live cell imaging, L-leucine was found to remarkably increase axonal length and growth velocity after axotomy. We also verified that L-leucine enhanced p-mTOR/p-S6K activation in neurons by testing with an mTOR inhibitor, rapamycin. Thereafter, we investigated the effects of L-leucine on the spinal cord injury in vivo. A mouse model of spinal cord hemi-section was established, and L-leucine was administered by tail intravenous injection. Basso mouse scale values revealed that L-leucine could improve functional recovery after injury. It was also notable that L-leucine treatment promoted axon growth across chondroitin sulfate proteoglycan (CSPG) areas. Furthermore, we used CSPGs as inhibitory environmental cues and clarified that L-leucine significantly enhanced axonal outgrowth and regeneration by promoting p-mTOR and p-S6K activation. Therefore, our study is the first to report that L-leucine promotes axonal regeneration in vitro and in vivo and could be candidate drug for axonal re-growth and nervous functional recovery.

Dynamic alterations of metabolites revealed the vascularization progression of bioengineered liver.

Vascularization is a critical but challenging process in developing functional bioengineered livers with the decellularized liver scaffolds (DLSs) and the process is accompanied by cell-specific metabolic alterations. To elucidate the dynamic alterations of metabolites during vascularization, rat DLSs were vascularized with human umbilical vein endothelial cells and liquid chromatography mass spectrometry-based metabolomics was performed on culture supernatants collected at 0, 1, 3, 7, 14, and 21 days. Overall, 1698 peak pairs or metabolites were detected in the culture supernatants, with 309 metabolites being positively identified. The orthogonal partial least-squares discriminant analysis and functional enrichment analysis revealed three phases that could be clearly discriminated, including Phase D1 (cell proliferation and migration), Phase D3D7 (vascular lumen formation), and Phase D14D21 (functional endothelial barrier formation). Seventy-two common differentially abundant metabolites of known identity were detected in these three phases when compared with Day 0. Of these metabolites, a high level of ß-Alanine indicated a better degree of vascularization and 14 days of in vitro dynamic culture is required to develop a functionalized vascular structure. These results enriched our understanding of the metabolic mechanism of DLS vascularization and indicated that ß-Alanine could function as a potential predictor of the patency of vascularized bioengineered livers.

BIPSE: A biomarker-based phase I/II design for immunotherapy trials with progression-free survival endpoint.

A Bayesian biomarker-based phase I/II design (BIPSE) is presented for immunotherapy trials with a progression-free survival (PFS) endpoint. The objective is to identify the subgroup-specific optimal dose, defined as the dose with the best risk-benefit tradeoff in each biomarker subgroup. We jointly model the immune response, toxicity outcome, and PFS with information borrowing across subgroups. A plateau model is used to describe the marginal distribution of the immune response. Conditional on the immune response, we model toxicity using probit regression and model PFS using the mixture cure rate model. During the trial, based on the accumulating data, we continuously update model estimates and adaptively randomize patients to doses with high desirability within each subgroup. Simulation studies show that the BIPSE design has desirable operating characteristics in selecting the subgroup-specific optimal doses and allocating patients to those optimal doses, and outperforms conventional designs.

Coordination-Directed Construction of Molecular Links.

Since the emergence of the concept of chemical topology, interlocked molecular assemblies have graduated from academic curiosities and poorly defined species to become synthetic realities. Coordination-directed synthesis provides powerful, diverse, and increasingly sophisticated protocols for accessing interlocked molecules. Originally, metal ions were employed solely as templates to gather and position building blocks in entwined or threaded arrangements. Recently, metal centers have increasingly featured within the backbones of the integral structural elements, which in turn use noncovalent interactions to self-assemble into intricate topologies. By outlining ingenious recent examples as well as seminal classic cases, this Review focuses on the role of metal-ligand paradigms in assembling molecular links. In addition, the ever-evolving approaches to efficient assembly, the structural features of the resulting architectures, and their prospects for the future are also presented.

MicroRNA Profile of Human Bone Marrow Mesenchymal Stem Cells during Hepatic Differentiation and Therapy.

Background and Aims: MicroRNAs (miRNAs) play important roles in hepatocyte differentiation from human bone marrow mesenchymal stem cells (hBMSCs) and the therapeutic application in vivo. However, the mechanisms of miRNA regulation are still unknown. This study aimed to profile the miRNA basis for improving the function of hBMSC-differentiated hepatocyte-like cells (hBMSC-Heps). Methods: Characteristic miRNAs of hBMSC-Heps were identified by transcriptome sequencing and validated by quantitative real-time polymerase chain reaction (qRT-PCR). An in vivo hBMSC transplantation model was used to assess the regulatory effects of miRNAs on liver regeneration during hBMSC therapy in pigs with fulminant hepatic failure (FHF). The biological functions of significant miRNA molecules were confirmed by transfection of miRNA activators or inhibitors into hBMSCs during hepatogenic differentiation. Results: The transcriptome of hBMSC-Heps showed characteristics distinct from those of undifferentiated hBMSCs. A total of 77 miRNAs were significantly differentially expressed in hBMSC-Heps at day 10 and day 20 after hBMSC differentiation that were directly related to the functions of hepatocytes. Among the top 10 significantly differentially expressed and the top 10 most abundant miRNAs, nine miRNAs that exhibited a pattern of gradual change were chosen for further analysis. The expression of nine miRNAs was confirmed by qRT-PCR in vitro and showed the same changing trends in vivo in an hBMSC transplantation model in pigs. Functional experiments with these miRNAs showed that activators of hsa-miR-26b-5p and hsa-miR-148a-3p and an inhibitor of hsa-miR-423-3p were sufficient to improve the differentiation of hBMSCs into hepatocyte-like cells. Conclusions: Transcriptome profiles of miRNA revealed the basis of the differentiation and development of hBMSC-Heps. Manipulation of three miRNAs (hsa-miR-26b-5p, hsa-miR-148a-3p and hsa-miR-423-3p) significantly improved hepatocyte generation and liver regeneration, indicating the potential of these miRNAs for future clinical applications.

SCI: A Bayesian adaptive phase I/II dose-finding design accounting for semi-competing risks outcomes for immunotherapy trials.

An immunotherapy trial often uses the phase I/II design to identify the optimal biological dose, which monitors the efficacy and toxicity outcomes simultaneously in a single trial. The progression-free survival rate is often used as the efficacy outcome in phase I/II immunotherapy trials. As a result, patients developing disease progression in phase I/II immunotherapy trials are generally seriously ill and are often treated off the trial for ethical consideration. Consequently, the happening of disease progression will terminate the toxicity event but not vice versa, so the issue of the semi-competing risks arises. Moreover, this issue can become more intractable with the late-onset outcomes, which happens when a relatively long follow-up time is required to ascertain progression-free survival. This paper proposes a novel Bayesian adaptive phase I/II design accounting for semi-competing risks outcomes for immunotherapy trials, referred to as the dose-finding design accounting for semi-competing risks outcomes for immunotherapy trials (SCI) design. To tackle the issue of the semi-competing risks in the presence of late-onset outcomes, we re-construct the likelihood function based on each patient's actual follow-up time and develop a data augmentation method to efficiently draw posterior samples from a series of Beta-binomial distributions. We propose a concise curve-free dose-finding algorithm to adaptively identify the optimal biological dose using accumulated data without making any parametric dose-response assumptions. Numerical studies show that the proposed SCI design yields good operating characteristics in dose selection, patient allocation, and trial duration.