Cell type-specific binding patterns reveal that TCF7L2 can be tethered to the genome by association with GATA3

BACKGROUND: The TCF7L2 transcription factor is linked to a variety of human diseases, including type 2 diabetes and cancer. One mechanism by which TCF7L2 could influence expression of genes involved in diverse diseases is by binding to distinct regulatory regions in different tissues. To test this hypothesis, we performed ChIP-seq for TCF7L2 in six human cell lines. RESULTS: We identified 116,000 non-redundant TCF7L2 binding sites, with only 1,864 sites common to the six cell lines. Using ChIP-seq, we showed that many genomic regions that are marked by both H3K4me1 and H3K27Ac are also bound by TCF7L2, suggesting that TCF7L2 plays a critical role in enhancer activity. Bioinformatic analysis of the cell type-specific TCF7L2 binding sites revealed enrichment for multiple transcription factors, including HNF4alpha and FOXA2 motifs in HepG2 cells and the GATA3 motif in MCF7 cells. ChIP-seq analysis revealed that TCF7L2 co-localizes with HNF4alpha and FOXA2 in HepG2 cells and with GATA3 in MCF7 cells. Interestingly, in MCF7 cells the TCF7L2 motif is enriched in most TCF7L2 sites but is not enriched in the sites bound by both GATA3 and TCF7L2. This analysis suggested that GATA3 might tether TCF7L2 to the genome at these sites. To test this hypothesis, we depleted GATA3 in MCF7 cells and showed that TCF7L2 binding was lost at a subset of sites. RNA-seq analysis suggested that TCF7L2 represses transcription when tethered to the genome via GATA3. CONCLUSIONS: Our studies demonstrate a novel relationship between GATA3 and TCF7L2, and reveal important insights into TCF7L2-mediated gene regulation

BCL6 modulates tissue neutrophil survival and exacerbates pulmonary inflammation following influenza virus infection

Neutrophils are vital for antimicrobial defense; however, their role during viral infection is less clear. Furthermore, the molecular regulation of neutrophil fate and function at the viral infected sites is largely elusive. Here we report that BCL6 deficiency in myeloid cells exhibited drastically enhanced host resistance to severe influenza A virus (IAV) infection. In contrast to the notion that BCL6 functions to suppress innate inflammation, we find that myeloid BCL6 deficiency diminished lung inflammation without affecting viral loads. Using a series of Cre-transgenic, reporter, and knockout mouse lines, we demonstrate that BCL6 deficiency in neutrophils, but not in monocytes or lung macrophages, attenuated host inflammation and morbidity following IAV infection. Mechanistically, BCL6 bound to the neutrophil gene loci involved in cellular apoptosis in cells specifically at the site of infection. As such, BCL6 disruption resulted in increased expression of apoptotic genes in neutrophils in the respiratory tract, but not in the circulation or bone marrow. Consequently, BCL6 deficiency promoted tissue neutrophil apoptosis. Partial neutrophil depletion led to diminished pulmonary inflammation and decreased host morbidity. Our results reveal a previously unappreciated role of BCL6 in modulating neutrophil apoptosis at the site of infection for the regulation of host disease development following viral infection. Furthermore, our studies indicate that tissue-specific regulation of neutrophil survival modulates host inflammation and tissue immunopathology during acute respiratory viral infection

Insights into the Jahn-Teller effect in layered oxide cathode materials for potassium-ion batteries

Potassium-ion batteries (PIBs) have attracted increasing interest as promising alternatives to lithium-ion batteries (LIBs) in large-scale electrical energy storage systems due to the potential price advantages, abundant availability of potassium resources, and low standard redox potential of potassium. However, the pursuit of suitable cathode materials that exhibit desirable characteristics such as voltage platforms, high capacity, and long cycling stability is of utmost importance. Recently, layered transition-metal oxides for PIBs offer great potential due to their high theoretical capacity, suitable voltage range, and eco-friendliness. Nevertheless, the progress of KxMO2 cathodes in PIBs faces obstacles due to the detrimental effects of structural disorder and irreversible phase transitions caused by the Jahn-Teller effect. This review provides a brief description of the origin and mechanism of the Jahn-Teller effect, accompanied by the proposed principles to mitigate this phenomenon. In particular, the current status of KxMO2 cathodes for PIBs, is summarized highlighting the challenges posed by the Jahn-Teller effect. Furthermore, promising strategies, such as composition modulation, synthesis approaches, and surface modification, are proposed to alleviate and suppress the Jahn-Teller effect. These strategies offer valuable insights into the prospects of innovative cathode materials and provide a foundation for future research in the field of PIBs

Reconstitution of Human Pdac Using Primary Cells Reveals Oncogenic Transcriptomic Features at Tumor Onset

Animal studies have demonstrated the ability of pancreatic acinar cells to transform into pancreatic ductal adenocarcinoma (PDAC). However, the tumorigenic potential of human pancreatic acinar cells remains under debate. To address this gap in knowledge, we expand sorted human acinar cells as 3D organoids and genetically modify them through introduction of common PDAC mutations. The acinar organoids undergo dramatic transcriptional alterations but maintain a recognizable DNA methylation signature. The transcriptomes of acinar organoids are similar to those of disease-specific cell populations. Oncogenic KRAS alone do not transform acinar organoids. However, acinar organoids can form PDAC in vivo after acquiring the four most common driver mutations of this disease. Similarly, sorted ductal cells carrying these genetic mutations can also form PDAC, thus experimentally proving that PDACs can originate from both human acinar and ductal cells. RNA-seq analysis reveal the transcriptional shift from normal acinar cells towards PDACs with enhanced proliferation, metabolic rewiring, down-regulation of MHC molecules, and alterations in the coagulation and complement cascade. By comparing PDAC-like cells with normal pancreas and PDAC samples, we identify a group of genes with elevated expression during early transformation which represent potential early diagnostic biomarkers

Both FA- and mPEG-conjugated chitosan nanoparticles for targeted cellular uptake and enhanced tumor tissue distribution

Tianjin Key Laboratory of Biomedical Materials; Xiamen Science and Technology project [3502Z20114007]; Fujian Provincial Health Department [2009-2-79]Both folic acid (FA)- and methoxypoly(ethylene glycol) (mPEG)- conjugated chitosan nanoparticles (NPs) had been designed for targeted and prolong anticancer drug delivery system. The chitosan NPs were prepared with combination of ionic gelation and chemical cross-linking method, followed by conjugation with both FA and mPEG, respectively. FA-mPEG-NPs were compared with either NPs or mPEG-/FA-NPs in terms of their size, targeting cellular efficiency and tumor tissue distribution. The specificity of the mPEG-FA-NPs targeting cancerous cells was demonstrated by comparative intracellular uptake of NPs and mPEG-/FA-NPs by human adenocarcinoma HeLa cells. Mitomycin C (MMC), as a model drug, was loaded to the mPEG-FA-NPs. Results show that the chitosan NPs presented a narrow-size distribution with an average diameter about 200 nm regardless of the type of functional group. In addition, MMC was easily loaded to the mPEG-FA-NPs with drug-loading content of 9.1%, and the drug releases were biphasic with an initial burst release, followed by a subsequent slower release. Laser confocal scanning imaging proved that both mPEG-FA-NPs and FA-NPs could greatly enhance uptake by HeLa cells. In vivo animal experiments, using a nude mice xenograft model, demonstrated that an increased amount of mPEG-FA-NPs or FA-NPs were accumulated in the tumor tissue relative to the mPEG-NPs or NPs alone. These results suggest that both FA-and mPEG-conjugated chitosan NPs are potentially prolonged drug delivery system for tumor cell-selective targeting treatments

PD-1hi CD8+ resident memory T cells balance immunity and fibrotic sequelae

CD8+ tissue-resident memory T (TRM) cells provide frontline immunity in mucosal tissues. The mechanisms regulating CD8+ TRM maintenance, heterogeneity, and protective and pathological functions are largely elusive. Here, we identify a population of CD8+ TRM cells that is maintained by major histocompatibility complex class I (MHC-I) signaling, and CD80 and CD86 costimulation after acute influenza infection. These TRM cells have both exhausted-like phenotypes and memory features and provide heterologous immunity against secondary infection. PD-L1 blockade after the resolution of primary infection promotes the rejuvenation of these exhausted-like TRM cells, restoring protective immunity at the cost of promoting postinfection inflammatory and fibrotic sequelae. Thus, PD-1 serves to limit the pathogenic capacity of exhausted-like TRM cells at the memory phase. Our data indicate that TRM cell exhaustion is the result of a tissue-specific cellular adaptation that balances fibrotic sequelae with protective immunity

On the Origin of Tibetans and Their Genetic Basis in Adapting High-Altitude Environments

Since their arrival in the Tibetan Plateau during the Neolithic Age, Tibetans have been well-adapted to extreme environmental conditions and possess genetic variation that reflect their living environment and migratory history. To investigate the origin of Tibetans and the genetic basis of adaptation in a rigorous environment, we genotyped 30 Tibetan individuals with more than one million SNP markers. Our findings suggested that Tibetans, together with the Yi people, were descendants of Tibeto-Burmans who diverged from ancient settlers of East Asia. The valleys of the Hengduan Mountain range may be a major migration route. We also identified a set of positively-selected genes that belong to functional classes of the embryonic, female gonad, and blood vessel developments, as well as response to hypoxia. Most of these genes were highly correlated with population-specific and beneficial phenotypes, such as high infant survival rate and the absence of chronic mountain sickness

Improved Direct Linear Transformation for Parameter Decoupling in Camera Calibration

For camera calibration based on direct linear transformation (DLT), the camera’s intrinsic and extrinsic parameters are simultaneously calibrated, which may cause coupling errors in the parameters and affect the calibration parameter accuracy. In this paper, we propose an improved direct linear transformation (IDLT) algorithm for calibration parameter decoupling. This algorithm uses a linear relationship of calibration parameter errors and obtains calibration parameters by moving a three-dimensional template. Simulation experiments were conducted to compare the calibration accuracy of DLT and IDLT algorithms with image noise and distortion. The results show that the IDLT algorithm calibration parameters achieve higher accuracy because the algorithm removes the coupling errors

Design of a novel curcumin-soybean phosphatidylcholine complex-based targeted drug delivery systems

Recently, the global trend in the field of nanomedicine has been toward the design of combination of nature active constituents and phospholipid (PC) to form a therapeutic drug-phospholipid complex. As a particular amphiphilic molecular complex, it can be a unique bridge of traditional dosage-form and novel drug delivery system. In thisarticle, on the basis of drug-phospholipid complex technique and self-assembly technique, we chose a pharmacologically safe and low toxic drug curcumin (CUR) to increase drug-loading ability, achieve controlled/sustained drug release and improve anticancer activity. A novel CUR-soybean phosphatidylcholine (SPC) complex and CUR-SPC complex self-assembled nanoparticles (CUR-SPC NPs) were prepared by a co-solvent method and a nanoprecipitation method. DSPE-PEG-FA was further functionalized on the surface of PEG-CUR-SPC NPs (designed as FA-PEG-CUR-SPC NPs) to specifically increase cellular uptake and targetability. The FA-PEG-CUR-SPC NPs showed a spherical shape, a mean diameter of about 180 nm, an excellent physiological stability and pH-triggered drug release. The drug entrapment efficiency and drug-loading content was up to 92.5 and 16.3%, respectively. In vitro cellular uptake and cytotoxicity studies demonstrated that FA-PEG-CUR-SPC NPs and CUR-SPC NPs presented significantly stronger cellular uptake efficacy and anticancer activity against HeLa cells and Caco-2 cells compared to free CUR, CUR-SPC NPs and PEG-CUR-SPC NPs. More importantly, FA-PEG-CUR-SPC NPs showed the prolonged systemic circulation lifetime and enhanced tumor accumulation compared with free CUR and PEG-CUR-SPC NPs. These results suggest that the FA targeted PEGylated CUR-SPC complex self-assembled NPs might be a promising candidate in cancer therapy