Current medicinal chemistry
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Synaptic plasticity requires careful synchronization and coordination of neurons and glial cells via various mechanisms of intercellular communication. Among them, are those mediated by i) connexin gap junction channels (GJCs), ii) connexin hemichannels and iii) pannexin channels. Whereas GJCs directly communicate the cytoplasm of contacting cells and coordinate electric and metabolic activities, connexin hemichannels and pannexin channels serve as diffusional pathways for ions and small molecules between the intra- and extracellular compartments. ⋯ Depending on intensity of the ischemic event, brain region and connexin subtype expressed, GJCs may provide proper diffusion of energy metabolites and dissipation of toxic substances, whereas, in other circumstances, they could increase damage by spreading toxic molecules. Alternatively, connexin hemichannel and pannexin channel opening may favor the release of neurotoxic substances (e.g., glutamate), but in other cases, they may confer neuroprotection against an ischemic episode by the phenomenon of ischemic preconditioning. Development of new drug modulators using in silico devices for connexin and pannexin-based channels will be crucial for future therapies against stroke.
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Review Case Reports
A PHACES syndrome unmasked by propranolol interruption in a tetralogy of Fallot patient: case report and extensive review on new indications of beta blockers.
Infantile hemangiomas (IHs) are the most common benign tumors of infancy and usually they don't require specific therapy. In 10-20% of cases IHs are able to generate complication and medical/surgical intervention is needed. For many decades standard treatment consisted in oral or intralesional corticosteroids until Leaute-Labreze and colleagues published the first report on the efficacy of propranolol for cutaneous infantile hemangiomas in 2008. ⋯ The pathophysiological explanation relies on the mechanism of action of propranolol which seems to act initially with vasoconstriction, down-regulating proangiogenetic factors and inducing endothelial cell apoptosis. Many decades since their introduction β-blockers are useful in a growing group of diseases. The pleiotropic effect of β-adrenoceptors antagonists is not yet deeply understood, residing in neurohormonal regulation systems and angiogenesis and proving to be an effective treatment from cardiovascular to oncological illnesses.
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Activation of hypoxia-inducible factor 1 (HIF-1) signaling is observed in a broad range of human cancers due to tumor hypoxia and epigenetic mechanisms. HIF-1 activation leads to the transcription of a plethora of target genes that promote physiological changes associated with therapeutic resistance, including the inhibition of apoptosis and senescence and the activation of drug efflux and cellular metabolism. ⋯ To date, multiple preclinical and clinical agents have been identified that effectively inhibit HIF-1 activity through various mechanisms, likely accounting for a portion of their anti-tumor efficacy. This review aims to provide an overview of our current understanding of the role of HIF-1 in therapeutic resistance and discuss the ongoing effort to develop HIF-1 inhibitors as an anti-cancer strategy.
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Nanomedicine, an emerging therapeutic tool in current medical frontiers, offers targeted drug delivery for many neurodegenerative disorders. Neuroinflammation, a hallmark of many neurodegenerative disorders, is mediated by microglia, the resident immunocompetent cells of the central nervous system (CNS). Microglial cells respond to various stimuli in the CNS resulting in their activation which may have a beneficial or a detrimental effect. ⋯ Use of non-degradable delivery systems and microglial activation in response to the drug delivery system further complicate drug delivery to the CNS. Nanomedicine, a nanoparticle-mediated drug delivery system, exhibits immense potential to overcome these hurdles in drug delivery to the CNS enabling new alternatives with significant promises in revolutionising the field of neurodegenerative disease therapy. This review attempts to summarise various regulatory factors in microglia, existing therapeutic strategies in controlling microglial activation, and how nanotechnology can serve to improve the delivery of therapeutic drugs across the BBB for treating microglia- mediated neuroinflammation and neurodegeneration.
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Voltage-gated sodium channels are large transmembrane protein complexes responsible for the propagation and transmission of electrical impulses through nerve, muscle and endocrine cells and cell systems. Dysregulated expression and/or functional changes of ion channel isoforms are found in many associated pathological conditions. In such cases, modulation of voltage gated sodium channels (Na(V) channels) is a recognised approach in medicinal chemistry. ⋯ Such compounds offer selective targeting and new possibilities for studying the physiology of Na(V) channels and pathophysiology of the associated ailment conditions. This review consolidates the recent literature on Na(V) 1.3, 1.7 and 1.8 channel isoform selective and/or state-dependent modulators. In particular, their structure-activity relationship is illustrated, especially in the context of selectivity on a particular isoform, and their applicability in the therapy of neuropathic pain is described.