T. Kendall Harden

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Phagocytic removal of apoptotic cells occurs efficiently in vivo such that even in tissues with significant apoptosis, very few apoptotic cells are detectable. This is thought to be due to the release of 'find-me' signals by apoptotic cells that recruit motile phagocytes such as monocytes, macrophages and dendritic cells, leading to the prompt clearance of(More)
The concept that adenine and uridine nucleotides function as extracellular signaling molecules has been markedly expanded in the last decade. At least 15 nucleotide-activated cell surface receptors exist, and remarkably broad and varied physiological responses are known to occur downstream of nucleotide receptor activation. The significance of nucleotides(More)
Nucleotides are important extracellular signaling molecules. At least five mammalian P2Y receptors exist that are specifically activated by ATP, UTP, ADP, or UDP. Although the existence of ectoenzymes that metabolize extracellular nucleotides is well established, the relative flux of ATP and UTP through their extracellular metabolic products remains(More)
The antagonist activity of N6-methyl 2'-deoxyadenosine 3',5'-bisphosphate (N6MABP) has been examined at the phospholipase C-coupled P2Y1 receptor of turkey erythrocyte membranes. N6MABP antagonized 2MeSATP-stimulated inositol phosphate hydrolysis with a potency approximately 20 fold greater than the previously studied parent molecule, adenosine(More)
Expression of the tumor suppressor deleted in liver cancer-1 (DLC-1) is lost in non-small cell lung (NSCLC) and other human carcinomas, and ectopic DLC-1 expression dramatically reduces proliferation and tumorigenicity. DLC-1 is a multi-domain protein that includes a Rho GTPase activating protein (RhoGAP) domain which has been hypothesized to be the basis(More)
Although P2 receptors mediate a myriad of physiological effects of extracellular adenine nucleotides, study of this broad class of receptors has been compromised by a lack of P2 receptor-selective antagonist molecules. The adenine nucleotide-promoted inositol lipid hydrolysis response of turkey erythrocyte membranes, which has been used extensively as a(More)
Transmembrane signals initiated by a broad range of extracellular stimuli converge on nodes that regulate phospholipase C (PLC)-dependent inositol lipid hydrolysis for signal propagation. We describe how heterotrimeric guanine nucleotide-binding proteins (G proteins) activate PLC-βs and in turn are deactivated by these downstream effectors. The 2.7-angstrom(More)
ATP is released from most cell types and functions as an extracellular signaling molecule through activation of members of the two large families of P2X and P2Y receptors. Although three mammalian P2Y receptors have been cloned that are selectively activated by uridine nucleotides, direct demonstration of the release of cellular UTP has not been reported.(More)
Novel analogues of the P2 receptor antagonist pyridoxal-5'-phosphate 6-azophenyl-2',5'-disulfonate (2) were synthesized and studied as antagonists in functional assays at recombinant rat P2X1, P2X2, and P2X3 receptors expressed in Xenopus oocytes (ion flux stimulation) and at turkey erythrocyte P2Y1 receptors (phospholipase C activation). Selected compounds(More)