A novel GPI-anchored dominant-negative TGF-ß receptor II renders T cells unresponsive to TGF-ß signaling.

Transforming growth factor ß (TGF-ß) is a pleiotropic cytokine expressed by a wide range of cell types and is known for hampering the effectiveness of cancer immune cell therapeutic approaches. We have designed a novel construct containing the extracellular domain of the TGF-ß receptor II linked to a glycosylphosphatidylinositol (GPI) anchor (GPI-ecto-TßRII) lacking the transmembrane and cytoplasmic signaling domain of TGF-ß receptor II (TßRII). T cells transduced with lentivirus expressing the GPI-ecto-TßRII construct show 5 to 15 times higher membrane expression compared with a previously established dominant-negative receptor carrying a truncated signaling domain. GPI-ecto-TßRII expression renders T cells unresponsive to TGF-ß-induced signaling seen by a lack of SMAD phosphorylation upon exogeneous TGF-ß treatment. Transduced T cells continue to express high levels of IFNγ and granulocyte-macrophage colony-stimulating factor (GM-CSF), among other cytokines, in the presence of TGF-ß while cytokine expression in untransduced T cells is being markedly suppressed. Furthermore, T cells expressing GPI-ecto-TßRII constructs have been shown to efficiently capture and inactivate TGF-ß from their environment. These results indicate the potential benefits of GPI-ecto-TßRII expressing cytotoxic T cells (CTLs) in future cell therapies.

An observational study of engineering online education during the COVID-19 pandemic.

The COVID-19 pandemic compelled the global and abrupt conversion of conventional face-to-face instruction to the online format in many educational institutions. Urgent and careful planning is needed to mitigate negative effects of pandemic on engineering education that has been traditionally content-centered, hands-on and design-oriented. To enhance engineering online education during the pandemic, we conducted an observational study at California State University, Long Beach (one of the largest and most diverse four-year university in the U.S.). A total of 110 faculty members and 627 students from six engineering departments participated in surveys and answered quantitative and qualitative questions to highlight the challenges they experienced during the online instruction in Spring 2020. Our results identified various issues that negatively influenced the online engineering education including logistical/technical problems, learning/teaching challenges, privacy and security concerns and lack of sufficient hands-on training. For example, more than half of the students indicated lack of engagement in class, difficulty in maintaining their focus and Zoom fatigue after attending multiple online sessions. A correlation analysis showed that while semi-online asynchronous exams were associated with an increase in the perceived cheating by the instructors, a fully online or open-book/open-note exams had an association with a decrease in instructor's perception of cheating. To address various identified challenges, we recommended strategies for educational stakeholders (students, faculty and administration) to fill the tools and technology gap and improve online engineering education. These recommendations are practical approaches for many similar institutions around the world and would help improve the learning outcomes of online educations in various engineering subfields. As the pandemic continues, sharing the results of this study with other educators can help with more effective planning and choice of best practices to enhance the efficacy of online engineering education during COVID-19 and post-pandemic.

Novel robust control of a 7-DOF exoskeleton robot.

This paper proposes a novel robust control method for the control of a 7-DOF exoskeleton robot. The external disturbances and unknown dynamics in the form of friction forces, different upper-limb's mass, backlash, and input saturation make robot unstable, which prevents the robot from correctly following the defined path. A new fractional sliding mode controller (NFSMC) is designed, which is robust against unknown dynamic and external disturbances. Fractional PID controller (FPID) has high trajectory tracking, but it is not robust against external disturbances. Therefore, by combining NFSMC and FPID controllers, a new compound fractional PID sliding mode controller (NCFPIDSMC) is proposed, which benefits high trajectory tracking of FPID and robustness of NFSMC. The stability of the proposed control method is verified by Lyapunov theory. A random noise is applied in order to confirm the robustness of the proposed control method.

MEMS gyroscope control using a novel compound robust control.

This paper proposes a new compound fractional order integral terminal sliding mode control (FOITSMC) and proportional-derivative control (PD-FOITSMC) for the control of a MEMS gyroscope. In order to improve the robustness of the conventional integral terminal sliding mode control (ITSMC), a fractional integral terminal sliding mode surface is applied. The chattering problem in FOITSMC, which is usually generated by the excitation of fast un-modelled dynamic is the main drawback. A PD controller is employed in order to eliminate chattering phenomenon. The stability of the PD-FOITSMC is proved by Lyapunov theory. The performance of the proposed control method is compared with two other controllers such as ITSMC and FOITSMC. Numerical simulations clearly verified the effectiveness of the proposed control approach.

Tumor-derived circulating endothelial cell clusters in colorectal cancer.

Clusters of tumor cells are often observed in the blood of cancer patients. These structures have been described as malignant entities for more than 50 years, although their comprehensive characterization is lacking. Contrary to current consensus, we demonstrate that a discrete population of circulating cell clusters isolated from the blood of colorectal cancer patients are not cancerous but consist of tumor-derived endothelial cells. These clusters express both epithelial and mesenchymal markers, consistent with previous reports on circulating tumor cell (CTC) phenotyping. However, unlike CTCs, they do not mirror the genetic variations of matched tumors. Transcriptomic analysis of single clusters revealed that these structures exhibit an endothelial phenotype and can be traced back to the tumor endothelium. Further results show that tumor-derived endothelial clusters do not form by coagulation or by outgrowth of single circulating endothelial cells, supporting a direct release of clusters from the tumor vasculature. The isolation and enumeration of these benign clusters distinguished healthy volunteers from treatment-naïve as well as pathological early-stage (≤IIA) colorectal cancer patients with high accuracy, suggesting that tumor-derived circulating endothelial cell clusters could be used as a means of noninvasive screening for colorectal cancer. In contrast to CTCs, tumor-derived endothelial cell clusters may also provide important information about the underlying tumor vasculature at the time of diagnosis, during treatment, and throughout the course of the disease.

A Role for RE-1-Silencing Transcription Factor in Embryonic Stem Cells Cardiac Lineage Specification.

During development, lineage specification is controlled by several signaling pathways involving various transcription factors (TFs). Here, we studied the RE-1-silencing transcription factor (REST) and identified an important role of this TF in cardiac differentiation. Using mouse embryonic stem cells (ESC) to model development, we found that REST knockout cells lost the ability to differentiate into the cardiac lineage. Detailed analysis of specific lineage markers expression showed selective downregulation of endoderm markers in REST-null cells, thus contributing to a loss of cardiogenic signals. REST regulates cardiac differentiation of ESCs by negatively regulating the Wnt/ß-catenin signaling pathway and positively regulating the cardiogenic TF Gata4. We propose here a new role for REST in cell fate specification besides its well-known repressive role of neuronal differentiation.

Co-motif discovery identifies an Esrrb-Sox2-DNA ternary complex as a mediator of transcriptional differences between mouse embryonic and epiblast stem cells.

Transcription factors (TF) often bind in heterodimeric complexes with each TF recognizing a specific neighboring cis element in the regulatory region of the genome. Comprehension of this DNA motif grammar is opaque, yet recent developments have allowed the interrogation of genome-wide TF binding sites. We reasoned that within this data novel motif grammars could be identified that controlled distinct biological programs. For this purpose, we developed a novel motif-discovery tool termed fexcom that systematically interrogates ChIP-seq data to discover spatially constrained TF-TF composite motifs occurring over short DNA distances. We applied this to the extensive ChIP-seq data available from mouse embryonic stem cells (ESCs). In addition to the well-known and most prevalent sox-oct motif, we also discovered a novel constrained spacer motif for Esrrb and Sox2 with a gap of between 2 and 8 bps that Essrb and Sox2 cobind in a selective fashion. Through the use of knockdown experiments, we argue that the Esrrb-Sox2 complex is an arbiter of gene expression differences between ESCs and epiblast stem cells (EpiSC). A number of genes downregulated upon dual Esrrb/Sox2 knockdown (e.g., Klf4, Klf5, Jam2, Pecam1) are similarly downregulated in the ESC to EpiSC transition and contain the esrrb-sox motif. The prototypical Esrrb-Sox2 target gene, containing an esrrb-sox element conserved throughout eutherian and metatherian mammals, is Nr0b1. Through positive regulation of this transcriptional repressor, we argue the Esrrb-Sox2 complex promotes the ESC state through inhibition of the EpiSC transcriptional program and the same trio may also function to maintain trophoblast stem cells.