Spherical 50 nm silica-based nanoparticles (SiNPs) promote healthy bone homeostasis and maintenance by supporting bone forming osteoblast lineage cells while simultaneously inhibiting the differentiation of bone resorbing osteoclasts. Previous work demonstrated that an intraperitoneal injection of SiNPs in healthy mice - both young and old - increased bone density and quality, suggesting the possibility that SiNPs represent a dual action therapeutic. However, the underlying mechanisms governing the osteoclast response to SiNPs have yet to be fully explored and defined.
View Article and Find Full Text PDFThe intake of dietary phosphate far exceeds recommended levels; however, the long-term health consequences remain relatively unknown. Here, the chronic physiological response to sustained elevated and reduced dietary phosphate consumption was investigated in mice. Although serum phosphate levels were brought into homeostatic balance, the prolonged intake of a high-phosphate diet dramatically and negatively impacted bone volume; generated a sustained increase in the phosphate responsive circulating factors FGF23, PTH, osteopontin and osteocalcin; and produced a chronic low-grade inflammatory state in the BM, marked by increased numbers of T cells expressing IL-17a, RANKL, and TNF-α.
View Article and Find Full Text PDFPhosphorus, often in the form of inorganic phosphate (Pi), is critical to cellular function on many levels; it is required as an integral component of kinase signaling, in the formation and function of DNA and lipids, and energy metabolism in the form of ATP. Accordingly, crucial aspects of cell mitosis - such as DNA synthesis and ATP energy generation - elevate the cellular requirement for Pi, with rapidly dividing cells consuming increased levels. Mechanisms to sense, respond, acquire, accumulate, and potentially seek Pi have evolved to support highly proliferative cellular states such as injury and malignant transformation.
View Article and Find Full Text PDFTumor heterogeneity drives disease progression, treatment resistance, and patient relapse, yet remains largely underexplored in invasion and metastasis. Here, we investigated heterogeneity within collective cancer invasion by integrating DNA methylation and gene expression analysis in rare purified lung cancer leader and follower cells. Our results showed global DNA methylation rewiring in leader cells and revealed the filopodial motor as a critical gene at the intersection of epigenetic heterogeneity and three-dimensional (3D) collective invasion.
View Article and Find Full Text PDFAberrant activation of Rho GTPase Rac1 has been observed in various tumor types, including pancreatic cancer. Rac1 activates multiple signaling pathways that lead to uncontrolled proliferation, invasion and metastasis. Thus, inhibition of Rac1 activity is a viable therapeutic strategy for proliferative disorders such as cancer.
View Article and Find Full Text PDFDesign, synthesis, and evaluation of α-methylene-γ-butyrolactone analogues and their evaluation as anticancer agents is described. SAR identified a spirocyclic analogue 19 that inhibited TNFα-induced NF-κB activity, cancer cell growth and tumor growth in an ovarian cancer model. A second iteration of synthesis and screening identified 29 which inhibited cancer cell growth with low-μM potency.
View Article and Find Full Text PDFDeubiquitinases (DUBs) play an important role in regulating the ubiquitin landscape of proteins. The DUB AMSH (associated molecule with the SH3 domain of STAM) has been shown to be involved in regulating the ubiquitin-dependent down-regulation of activated cell surface receptors via the endolysosomal degradative pathway. Therefore, small molecule AMSH inhibitors will be useful chemical probes to study the effect of AMSH DUB activity on cell surface receptor degradation.
View Article and Find Full Text PDFPurpose: The presence of TNF-α in approximately 50% of surgically resected tumors suggests that the canonical NF-κB and the mTOR pathways are activated. Inhibitor of IκB kinase β (IKKβ) acts as the signaling node that regulates transcription via the p-IκBα/NF-κB axis and regulates translation via the mTOR/p-S6K/p-eIF4EBP axis. A kinome screen identified a quinoxaline urea analog 13-197 as an IKKβ inhibitor.
View Article and Find Full Text PDFCarbon monoxide (CO) is a product of haem metabolism and organisms must evolve strategies to prevent endogenous CO poisoning of haemoproteins. We show that energy costs associated with conformational changes play a key role in preventing irreversible CO binding. AxCYTcp is a member of a family of haem proteins that form stable 5c-NO and 6c-CO complexes but do not form O(2) complexes.
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