Human cancers are complex ecosystems composed of cells with distinct phenotypes, genotypes, and epigenetic states, but current models do not adequately reflect tumor composition in patients. We used single-cell RNA sequencing (RNA-seq) to profile 430 cells from five primary glioblastomas, which we found to be inherently variable in their expression of diverse transcriptional programs related to oncogenic signaling, proliferation, complement/immune response, and hypoxia. We also observed a continuum of stemness-related expression states that enabled us to identify putative regulators of stemness in vivo. Finally, we show that established glioblastoma subtype classifiers are variably expressed across individual cells within a tumor and demonstrate the potential prognostic implications of such intratumoral heterogeneity. Thus, we reveal previously unappreciated heterogeneity in diverse regulatory programs central to glioblastoma biology, prognosis, and therapy.

/pdf/single-cell-rna-seq-highlights-intratumoral-heterogeneity-in-3izlod61be.pdf

Single-cell RNA-seq highlights intratumoral heterogeneity in primary glioblastoma

Fibroblast growth factor/fibroblast growth factor receptor system in angiogenesis.

Molecular basis of the effects of shear stress on vascular endothelial cells.

Atherosclerotic lesion localization to regions of disturbed flow within certain arterial geometries, in humans and experimental animals, suggests an important role for local hemodynamic forces in atherogenesis. To explore how endothelial cells (EC) acquire functional/dysfunctional phenotypes in response to vascular region-specific flow patterns, we have used an in vitro dynamic flow system to accurately reproduce arterial shear stress waveforms on cultured human EC and have examined the effects on EC gene expression by using a high-throughput transcriptional profiling approach. The flow patterns in the carotid artery bifurcations of several normal human subjects were characterized by using 3D flow analysis based on actual vascular geometries and blood flow profiles. Two prototypic arterial waveforms, “athero-prone” and “athero-protective,” were defined as representative of the wall shear stresses in two distinct regions of the carotid artery (carotid sinus and distal internal carotid artery) that are typically “susceptible” or “resistant,” respectively, to atherosclerotic lesion development. These two waveforms were applied to cultured EC, and cDNA microarrays were used to analyze the differential patterns of EC gene expression. In addition, the differential effects of athero-prone vs. athero-protective waveforms were further characterized on several parameters of EC structure and function, including actin cytoskeletal organization, expression and localization of junctional proteins, activation of the NF-κB transcriptional pathway, and expression of proinflammatory cytokines and adhesion molecules. These global gene expression patterns and functional data reveal a distinct phenotypic modulation in response to the wall shear stresses present in atherosclerosis-susceptible vs. atherosclerosis-resistant human arterial geometries.

/pdf/distinct-endothelial-phenotypes-evoked-by-arterial-waveforms-9l8hurfr2c.pdf

Distinct endothelial phenotypes evoked by arterial waveforms derived from atherosclerosis-susceptible and -resistant regions of human vasculature

In the face of systemic risk factors, certain regions of the arterial vasculature remain relatively resistant to the development of atherosclerotic lesions. The biomechanically distinct environments in these arterial geometries exert a protective influence via certain key functions of the endothelial lining; however, the mechanisms underlying the coordinated regulation of specific mechano-activated transcriptional programs leading to distinct endothelial functional phenotypes have remained elusive. Here, we show that the transcription factor Kruppel-like factor 2 (KLF2) is selectively induced in endothelial cells exposed to a biomechanical stimulus characteristic of atheroprotected regions of the human carotid and that this flow-mediated increase in expression occurs via a MEK5/ERK5/MEF2 signaling pathway. Overexpression and silencing of KLF2 in the context of flow, combined with findings from genome-wide analyses of gene expression, demonstrate that the induction of KLF2 results in the orchestrated regulation of endothelial transcriptional programs controlling inflammation, thrombosis/hemostasis, vascular tone, and blood vessel development. Our data also indicate that KLF2 expression globally modulates IL-1beta-mediated endothelial activation. KLF2 therefore serves as a mechano-activated transcription factor important in the integration of multiple endothelial functions associated with regions of the arterial vasculature that are relatively resistant to atherogenesis.

/pdf/integration-of-flow-dependent-endothelial-phenotypes-by-25uafcly3t.pdf

Integration of flow-dependent endothelial phenotypes by Kruppel-like factor 2

Biomechanical forces can modulate endothelial phenotype through changes in gene expression. We hypothesized that physiological laminar shear stresses (LSS) act as differentiative stimuli on endothelial cells (EC) to alter gene expression, creating an antioxidant, anti-apoptotic and anti-proliferative environment. The transcriptional profile of cultured human umbilical vein endothelial cells (HUVEC) exposed to LSS was evaluated by GeneCalling; 107 genes demonstrated at least a twofold change in expression at 24 h (LSS vs. static). These flow-responsive genes represent a limited number of functional clusters that include transcription factors, antioxidants, signaling molecules, cell cycle regulators, and genes involved in cellular differentiation. Immunohistochemistry and in situ hybridization confirmed that many of these flow-responsive genes, including the novel basic helix-loop-helix transcription factor Hath6, are expressed in EC in vivo. Thus these data identify a limited set of flow-responsive genes expressed in the endothelium that may be responsible for the establishment and maintenance of the flow-adapted endothelial phenotype in vivo.

Gene expression profile of human endothelial cells exposed to sustained fluid shear stress.

Vascular endothelial cells maintain the interface between the systemic circulation and soft tissues and mediate critical processes such as inflammation in a vascular bed-selective fashion. To expan...

https://www.physiology.org/doi/pdf/10.1152/physiolgenomics.00186.2002

Identification of endothelial cell genes by combined database mining and microarray analysis.

The Mg−Al composite supports (MgAlO) with different Mg/Al ratios were prepared by hydrothermal method. Then a series of PtSn/MgAlO catalysts were prepared and the influence of Mg/Al ratios on the physicochemical properties and the catalytic performances for propane dehydrogenation were investigated. The catalysts were characterized by means of X-ray diffraction, N2 adsorption-desorption, H2 temperature-programmed reduction, NH3 temperature-programmed desorption and Raman. Compared with Al2O3 and MgO support, MgAlO support is beneficial to the dispersion of Pt. And the dispersion of Pt is influenced by the Mg/Al ratios. When the ratio of Mg/Al is 1/10, the dispersion of Pt is the highest, which results in high propane dehydrogenation activity. 

One‐Pot Synthesis of MgAlO Support for PtSn Catalysts over Propane Dehydrogenation

The interactions between three flavonoids (liquiritin, quercitrin, and taxifolin) and human serum albumin (HSA) are investigated by spectroscopic techniques, isothermal titration calorimetry (ITC), and molecular docking study. Results show that...

Investigation of the interactions between three flavonoids and human serum albumin by isothermal titration calorimetry, spectroscopy, and molecular docking

Ying Zhang

Papers

Gene expression profile of human endothelial cells exposed to sustained fluid shear stress.

Identification of endothelial cell genes by combined database mining and microarray analysis.

One‐Pot Synthesis of MgAlO Support for PtSn Catalysts over Propane Dehydrogenation

Investigation of the interactions between three flavonoids and human serum albumin by isothermal titration calorimetry, spectroscopy, and molecular docking

Comparative study of the binding between chlorogenic acid and four proteins by isothermal titration calorimetry, spectroscopy and docking methods