Epigenetic processes play a key role in orchestrating transcriptional regulation during development. The importance of DNA methylation in fetal brain development is highlighted by the dynamic ...expression of de novo DNA methyltransferases during the perinatal period and neurodevelopmental deficits associated with mutations in the methyl-CpG binding protein 2 (MECP2) gene. However, our knowledge about the temporal changes to the epigenome during fetal brain development has, to date, been limited. We quantified genome-wide patterns of DNA methylation at ∼ 400,000 sites in 179 human fetal brain samples (100 male, 79 female) spanning 23 to 184 d post-conception. We identified highly significant changes in DNA methylation across fetal brain development at >7% of sites, with an enrichment of loci becoming hypomethylated with fetal age. Sites associated with developmental changes in DNA methylation during fetal brain development were significantly underrepresented in promoter regulatory regions but significantly overrepresented in regions flanking CpG islands (shores and shelves) and gene bodies. Highly significant differences in DNA methylation were observed between males and females at a number of autosomal sites, with a small number of regions showing sex-specific DNA methylation trajectories across brain development. Weighted gene comethylation network analysis (WGCNA) revealed discrete modules of comethylated loci associated with fetal age that are significantly enriched for genes involved in neurodevelopmental processes. This is, to our knowledge, the most extensive study of DNA methylation across human fetal brain development to date, confirming the prenatal period as a time of considerable epigenomic plasticity.
Clonal hematopoiesis (CH) results from somatic genomic alterations that drive clonal expansion of blood cells. Somatic gene mutations associated with hematologic malignancies detected in ...hematopoietic cells of healthy individuals, referred to as CH of indeterminate potential (CHIP), have been associated with myeloid malignancies, while mosaic chromosomal alterations (mCAs) have been associated with lymphoid malignancies. Here, we analyzed CHIP in 55,383 individuals and autosomal mCAs in 420,969 individuals with no history of hematologic malignancies in the UK Biobank and Mass General Brigham Biobank. We distinguished myeloid and lymphoid somatic gene mutations, as well as myeloid and lymphoid mCAs, and found both to be associated with risk of lineage-specific hematologic malignancies. Further, we performed an integrated analysis of somatic alterations with peripheral blood count parameters to stratify the risk of incident myeloid and lymphoid malignancies. These genetic alterations can be readily detected in clinical sequencing panels and used with blood count parameters to identify individuals at high risk of developing hematologic malignancies.
The ongoing coronavirus disease 2019 (COVID-19) pandemic is associated with substantial morbidity and mortality. Although much has been learned in the first few months of the pandemic, many features ...of COVID-19 pathogenesis remain to be determined. For example, anosmia is a common presentation, and many patients with anosmia show no or only minor respiratory symptoms
. Studies in animals infected experimentally with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the cause of COVID-19, provide opportunities to study aspects of the disease that are not easily investigated in human patients. Although the severity of COVID-19 ranges from asymptomatic to lethal
, most experimental infections provide insights into mild disease
. Here, using K18-hACE2 transgenic mice that were originally developed for SARS studies
, we show that infection with SARS-CoV-2 causes severe disease in the lung and, in some mice, the brain. Evidence of thrombosis and vasculitis was detected in mice with severe pneumonia. Furthermore, we show that infusion of convalescent plasma from a recovered patient with COVID-19 protected against lethal disease. Mice developed anosmia at early time points after infection. Notably, although pre-treatment with convalescent plasma prevented most signs of clinical disease, it did not prevent anosmia. Thus, K18-hACE2 mice provide a useful model for studying the pathological basis of both mild and lethal COVID-19 and for assessing therapeutic interventions.
The genetic programs that maintain leukemia stem cell (LSC) self-renewal and oncogenic potential have been well defined; however, the comprehensive epigenetic landscape that sustains LSC cellular ...identity and functionality is less well established. We report that LSCs in MLL-associated leukemia reside in an epigenetic state of relative genome-wide high-level H3K4me3 and low-level H3K79me2. LSC differentiation is associated with reversal of these broad epigenetic profiles, with concomitant downregulation of crucial MLL target genes and the LSC maintenance transcriptional program that is driven by the loss of H3K4me3, but not H3K79me2. The H3K4-specific demethylase KDM5B negatively regulates leukemogenesis in murine and human MLL-rearranged AML cells, demonstrating a crucial role for the H3K4 global methylome in determining LSC fate.
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•MLL LSCs are maintained in a hyper-H3K4me3 and hypo-H3K79me2 epigenomic state•LSC differentiation is associated with global inversion of the histone methylome•H3K4me3 serves a crucial mechanistic role in LSC maintenance•Histone demethylase KDM5B negatively regulates LSC potential
Wong et al. show that leukemia stem cells (LSCs) in MLL-rearranged leukemia are in a relative genome-wide high-H3K4me3 and low-H3K79me2 state. Differentiation of LSCs reverses this pattern, but the reduced expression of key MLL target genes is driven mainly by the loss of H3K4me3, which is regulated by KDM5B.
A novel reassortant derived from North American triple-reassortant (TRsw) and Eurasian swine (EAsw) influenza viruses acquired sustained human-to-human transmissibility and caused the 2009 influenza ...pandemic. To identify molecular determinants that allowed efficient transmission of the pandemic H1N1 virus among humans, we evaluated the direct-contact and respiratory-droplet transmissibility in ferrets of representative swine influenza viruses of different lineages obtained through a 13-y surveillance program in southern China. Whereas all viruses studied were transmitted by direct contact with varying efficiency, respiratory-droplet transmissibility (albeit inefficient) was observed only in the TRsw-like A/swine/Hong Kong/915/04 (sw915) (H1N2) virus. The sw915 virus had acquired the M gene derived from EAsw and differed from the gene constellation of the pandemic H1N1 virus by the neuraminidase (NA) gene alone. Glycan array analysis showed that pandemic H1N1 virus A/HK/415742/09 (HK415742) and sw915 possess similar receptor-binding specificity and affinity for α2,6-linked sialosides. Sw915 titers in differentiated normal human bronchial epithelial cells and in ferret nasal washes were lower than those of HK415742. Introducing the NA from pandemic HK415742 into sw915 did not increase viral replication efficiency but increased respiratory-droplet transmissibility, despite a substantial amino acid difference between the two viruses. The NA of the pandemic HK415742 virus possessed significantly higher enzyme activity than that of sw915 or other swine influenza viruses. Our results suggest that a unique gene constellation and hemagglutinin–neuraminidase balance play a critical role in acquisition of efficient and sustained human-to-human transmissibility.
Although many bacterial lipases and PHA depolymerases have been identified, cloned, and characterized, there is very little information on the potential application of lipases and PHA depolymerases, ...especially intracellular enzymes, for the degradation of polyester polymers/plastics. We identified genes encoding an intracellular lipase (LIP3), an extracellular lipase (LIP4), and an intracellular PHA depolymerase (PhaZ) in the genome of the bacterium
PA23. We cloned these genes into
and then expressed, purified, and characterized the biochemistry and substrate preferences of the enzymes they encode. Our data suggest that the LIP3, LIP4, and PhaZ enzymes differ significantly in their biochemical and biophysical properties, structural-folding characteristics, and the absence or presence of a lid domain. Despite their different properties, the enzymes exhibited broad substrate specificity and were able to hydrolyze both short- and medium-chain length polyhydroxyalkanoates (PHAs), para-nitrophenyl (pNP) alkanoates, and polylactic acid (PLA). Gel Permeation Chromatography (GPC) analyses of the polymers treated with LIP3, LIP4, and PhaZ revealed significant degradation of both the biodegradable as well as the synthetic polymers poly(ε-caprolactone) (PCL) and polyethylene succinate (PES).
Background
The prevalence of gastroesophageal reflux disease (GERD) and laryngopharyngeal reflux (LPR) in post‐irradiated patients with nasopharyngeal carcinoma (NPC) is unknown.
Materials and ...methods
In a cross‐sectional study, 31 NPC and 12 control patients completed questionnaires for GERD/LPR before esophageal manometry and 24‐h pH monitoring. The DeMeester score and reflux finding score (RFS) were used to define GERD and LPR, respectively. Risk factors were identified.
Results
51.6% of NPC and 8.3% of control patients, and 77.4% of NPC and 33% of control patients, were GERD‐positive and LPR‐positive, respectively. The GERD/LPR questionnaire failed to identify either condition in patients with NPC. No parameter differences in esophageal manometry or pneumonia incidence were noted between GERD/LPR‐positive and GERD/LPR‐negative patients. Post radiotherapy duration, high BMI, lack of chemotherapy, and dysphagia were positive risk factors for GERD/LPR.
Conclusions
A high prevalence of GERD/LPR in patients with post‐irradiated NPC exists, but reflux symptoms are inadequate for diagnosis.
There is growing interest in using PET/CT for evaluating early response to therapy in cancer treatment. Although widely available and convenient to use, standardized uptake value (SUV) measurements ...can be influenced by a variety of biologic and technologic factors. Many of these factors can be addressed with close attention to detail and appropriate quality control. This article will review factors potentially affecting SUV measurements and provide recommendations on ways to minimize when using serial PET to assess early response to therapy.
Scanner and reconstruction parameters can significantly affect SUV measurements. When using serial SUV measurements to assess early response to therapy, imaging should be performed on the same scanner using the same image acquisition and reconstruction protocols. In addition, attention to detail is required for accurate determination of the administered radiopharmaceutical dose.
An unmet need in cell engineering is the availability of a single transgene encoded, functionally inert, human polypeptide that can serve multiple purposes, including ex vivo cell selection, in vivo ...cell tracking, and as a target for in vivo cell ablation. Here we describe a truncated human EGFR polypeptide (huEGFRt) that is devoid of extracellular N-terminal ligand binding domains and intracellular receptor tyrosine kinase activity but retains the native amino acid sequence, type I transmembrane cell surface localization, and a conformationally intact binding epitope for pharmaceutical-grade anti-EGFR monoclonal antibody, cetuximab (Erbitux). After lentiviral transduction of human T cells with vectors that coordinately express tumor-specific chimeric antigen receptors and huEGFRt, we show that huEGFRt serves as a highly efficient selection epitope for chimeric antigen receptor+ T cells using biotinylated cetuximab in conjunction with current good manufacturing practices (cGMP)-grade anti-biotin immunomagnetic microbeads. Moreover, huEGFRt provides a cell surface marker for in vivo tracking of adoptively transferred T cells using both flow cytometry and immunohistochemistry, and a target for cetuximab-mediated antibody-dependent cellular cytotoxicity and in vivo elimination. The versatility of huEGFRt and the availability of pharmaceutical-grade reagents for its clinical application denote huEGFRt as a significant new tool for cellular engineering.
Background
Exercise‐based swallowing training (EBST) and transcutaneous neuromuscular electrical stimulation (TNMES) are common modalities used to treat late dysphagia after radiotherapy for ...nasopharyngeal carcinoma (NPC). We aimed to investigate and compare the efficacies of EBST and TNMES as proactive treatments administered early after radiotherapy.
Methods
Patients with early post‐radiotherapy NPC (n = 120) underwent either TNMES or EBST. Flexible endoscopic evaluation of swallowing (FEES), quality of life (QOL), and swallowing function questionnaires were completed before the intervention as well as immediately, 6, and 12 months after the intervention. Outcome measures included the scores for the swallowing function score (SFS), penetration and aspiration scale (PAS), dynamic imaging grade of swallowing toxicity (DIGEST), functional oral intake scale (FOIS), swallowing performance status scale (SPSS), pharyngeal motor impairment (PMI), pharyngeal function impairment (PFI), and functional assessment after cancer therapy–nasopharyngeal (FACT‐NP) questionnaire.
Results
Three months after radiotherapy, 31 and 34 patients underwent TNMES and EBST, respectively, and completed swallowing assessments at all four assessment timepoints. All patients showed post‐radiotherapy impairments in the SFS, PAS, DIGEST, PMI, and PFI. Compared with the EBST group, the TNMES group showed significant improvements in the PFI and PMI scores, with small‐to‐medium effect sizes. Additionally, compared with the EBST group, the TNMES group demonstrated a trend toward slightly better improvements in the PAS, DIGEST, FOIS, and SPSS scores immediately and 6 months after the intervention. The SFS scores improved from baseline in both groups; however, the TNMES group showed an earlier improvement. Finally, the TNMES group showed better QOL according to the FACT‐NP than the EBST group.
Conclusion
Proactive TMNES and EBST are safe and feasible modalities for improving swallowing in patients with NPC when administered early after radiotherapy. Although TNMES showed better results than EBST, these results should be interpreted with caution given the study limitations.
Level of evidence
1B.
This study investigated the outcomes of proactive swallowing training by electric neuromuscular stimulation and swallowing exercise in early post irradiated patients with nasopharyngeal carcinoma and results shows neuromuscular stimulation and swallowing exercise are feasible to improve swallowing in 12 months follow up assessment. Electrical neuromuscular stimulation is better than swallowing exercise in some aspect of swallowing function.
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