A total of 1,281 Chinese students in grades 3-6 participated in a study that examined the relationships among student-perceived supportive learning environment (PSLE), mathematical achievement, autonomous self-regulation, and creative thinking. The results demonstrated that student PSLE is positively associated with autonomous self-regulation, creative thinking, and mathematical achievement. In addition, the study also demonstrated that the influence of PSLE on students' mathematical achievements could be mediated through autonomous self-regulation and creative thinking, respectively.
View Article and Find Full Text PDFResidual host cell proteins (HCPs) in the drug product can affect product quality, stability, and/or safety. In particular, highly active hydrolytic enzymes at sub-ppm levels can negatively impact the shelf life of drug products but are challenging to identify by liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) due to their high dynamic range between HCPs and biotherapeutic proteins. We employed new strategies to address the challenge: (1) native digest at a high protein concentration; (2) sodium deoxycholate added during the reduction step to minimize the inadvertent omission of HCPs observed with native digestion; and (3) solid phase extraction with 50% MeCN elution prior to LC-MS/MS analysis to ensure effective mAb removal.
View Article and Find Full Text PDFChinese hamster ovary (CHO) cell engineering based on CRISPR/Cas9 knockout (KO) technology requires the delivery of guide RNA (gRNA) and Cas9 enzyme for efficient gene targeting. With an ever-increasing list of promising gene targets, developing, and optimizing a multiplex gene KO protocol is crucial for rapid CHO cell engineering. Here, we describe a method that can support efficient targeting and KO of up to 10 genes through sequential transfections.
View Article and Find Full Text PDFDegradation of polysorbate (PS) by hydrolytically active host cell proteins (HCPs) in drug products may impair the protein-stabilizing properties of PS and lead to the formation of particles due to the accumulation of poorly soluble free fatty acids upon long-term storage. The identification of the causative enzymes is challenging due to their low-abundance even when using state-of-the-art instrumentation and workflows. To overcome these challenges, we developed a rigorous enrichment strategy for HCPs, utilizing both Protein A and anti-HCP affinity chromatography, which facilitated the in-depth characterization of the HCP population in a monoclonal antibody formulation prone to PS hydrolysis.
View Article and Find Full Text PDFFunctional activation of the transforming growth factor-β (TGF-β) receptors (TGFBRs) is carefully regulated through integration of post-translational modifications, spatial regulation at the cellular level, and TGFBR availability at the cell surface. Although the bulk of TGFBRs resides inside the cells, AKT Ser/Thr kinase (AKT) activation in response to insulin or other growth factors rapidly induces transport of TGFBRs to the cell surface, thereby increasing the cell's responsiveness to TGF-β. We now demonstrate that TGF-β itself induces a rapid translocation of its own receptors to the cell surface and thus amplifies its own response.
View Article and Find Full Text PDFTGF-β1 signaling is a critical driver of collagen accumulation and fibrotic disease but also a vital suppressor of inflammation and epithelial cell proliferation. The nature of this multifunctional cytokine has limited the development of global TGF-β1 signaling inhibitors as therapeutic agents. We conducted phenotypic screens for small molecules that inhibit TGF-β1-induced epithelial-mesenchymal transition without immediate TGF-β1 receptor (TβR) kinase inhibition.
View Article and Find Full Text PDFTrends Cell Biol
September 2017
Transforming growth factor (TGF)-β family proteins control cell physiology, proliferation, and growth, and direct cell differentiation, thus playing key roles in normal development and disease. The mechanisms of how TGF-β family ligands interact with heteromeric complexes of cell surface receptors to then activate Smad signaling that directs changes in gene expression are often seen as established. Even though TGF-β-induced Smad signaling may be seen as a linear signaling pathway with predictable outcomes, this pathway provides cells with a versatile means to induce different cellular responses.
View Article and Find Full Text PDFBackground: Chronic kidney disease-mineral bone disorder (CKD-MBD), a newly defined disorder in patients with CKD, describes the interacting triad of (1) biochemical abnormalities of calcium, phosphorus and parathyroid hormone (PTH), (2) extraskeletal calcification and (3) abnormal bone.
Methods: We studied the effects of the calcimimetic R-568, R-568 with calcium (R-568 + Ca) or calcium (Ca) alone compared with control CKD rats on this triad in the Cy/+ male rat, a model of progressive CKD that spontaneously develops CKD-MBD on a normal phosphorus diet. Animals were treated for either 14 or 18 weeks beginning at 20 weeks of age (34-week and 38-week animals, respectively).
Chronic Kidney Disease-Mineral Bone Disorder (CKD-MBD) is a newly defined syndrome encompassing patients with chronic kidney disease that have a triad of biochemical alterations in calcium, phosphorus and parathyroid hormone, vascular calcification, and bone abnormalities. Here we describe a novel Cy/+ rat model of slowly progressive kidney disease spontaneously developing the three components of CKD-MBD when fed a normal phosphorus diet. Since the renal disorder progressed 'naturally' we studied the effect of dietary manipulation during the course of the disease.
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