Table of Contents

August 2009; 9 (4)

Departments

Open Channels

Reflections

Nascent Transcripts

Beyond the Bench

Outliers

Viewpoints

  • Angiogenesis, the process of forming new blood vessels, is a well established and clinically relevant feature of a variety of disease states. Whether blood vessels sprout in a given tissue environment depends on the balance between factors that stimulate angiogenesis and those that impede it. Potent pro-angiogenic factors such as vascular endothelial growth factor (VEGF) have been identified, validated, and successfully used in the clinic. Likewise, anti-angiogenic factors are also emerging as biologically relevant and therapeutically useful entities. PAR1 is a G protein–coupled receptor (GPCR) that participates in hemostasis and vascular development and that mediates the angiogenic activity of thrombin. PAR1 is activated through proteolytic cleavage of its first forty-one extracellular residues by a variety of proteases, most notably thrombin. However, little effort has focused on the forty-one–residue peptide fragment liberated during PAR1 activation. Tsopanoglou and colleagues have now demonstrated that this peptide, parstatin, has intriguing antiangiogenic activity, and, in a follow-up study, they demonstrate its potential pharmacological utility using a rat model of ischemic heart disease.

  • Regenerative medicine utilizes cutting-edge technologies to repair and replace damaged cells, tissues, and organs for functional restoration. This broadly interdisciplinary field draws from cell and molecular biology, genetics, immunology, surgical sciences, physiology, biomedical and tissue engineering, chemical and material sciences, and nanotechnology. Certainly, pharmacology serves as an integral component of regenerative medicine, a concept first elucidated in depth in this journal. We operationally define regenerative pharmacology as the application of pharmacological sciences to accelerate, optimize, or characterize the development, maturation, and function of bioengineered and regenerating tissues, either in vitro or in vivo. Diabetes mellitus, a condition defined by elevated levels of glucose in the blood, represents a compelling target for regenerative medicine, through a variety of complementary strategies. A recent report from the laboratory of Peter Schultz of small molecules capable of stimulating the proliferation of insulin-producing pancreatic β cells highlights the potential of regenerative pharmacology to develop novel treatments for this important disease.

Reviews

  • The anti-alcoholism drug disulfiram (Antabuse), which is an inhibitor of aldehyde dehydrogenase, induces an aversive reaction to alcohol consumption and thereby helps patients reduce alcohol intake. Recent clinical trials, initiated to investigate whether disulfiram could be used to treat individuals who abuse both alcohol and cocaine, have indicated that disulfiram effectively decreases cocaine consumption. Yet the ability of disulfiram to curb cocaine intake cannot be explained by the disruption of ethanol metabolism. Here, we synthesize clinical and animal data that point to dopamine β-hydroxylase inhibition as a mechanism underlying the efficacy of disulfiram in the treatment of cocaine dependence.

  • Chemokines and chemokine receptors are widely expressed in the nervous system, where they play roles in the regulation of stem cell migration, axonal path finding, and neurotransmission. Chemokine signaling is also of key importance in the regulation of neuroinflammatory responses. The expression of the chemokine monocyte chemoattractant protein 1 (MCP1) and its receptor (CCR2) is upregulated by dorsal root ganglia neurons in rodent models of neuropathic pain. MCP1 increases the excitability of nociceptive neurons after a peripheral nerve injury, and disruption of MCP1 signaling blocks the development of neuropathic pain. In the spinal cord, microglial cells expressing CCR2 are thought to play an active role in the initiation and maintenance of pain hypersensitivity, and MCP1 may also alter the excitability of spinal neurons in some cases. Other predominant sites of CCR2 activation are found in the peripheral nervous system, thereby explaining, at least in some circumstances, the rapid anti-nociceptive effects of peripherally administered CCR2 antagonists. In this article we discuss the relative roles of CCR2 activation in the peripheral and central nervous systems in relation to the phenomenon of neuropathic pain.