Current pharmaceutical design
-
Bisphosphonates are widely used in the treatment of diseases involving excessive bone resorption, such as osteoporosis, cancer-associated bone disease, and Paget's disease of bone. They target to the skeleton due to their calcium-chelating properties, where they primarily act by inhibiting osteoclast-mediated bone resorption. The simple bisphosphonates, clodronate, etidronate and tiludronate, are intracellularly metabolised to cytotoxic ATP analogues, while the more potent, nitrogen-containing bisphosphonates act by inhibiting the enzyme FPP synthase, thereby preventing the prenylation of small GTPases that are necessary for the normal function and survival of osteoclasts. ⋯ Furthermore, increasing evidence implicates monocytes and macrophages as direct targets of bisphosphonate action, which may explain the acute phase response and the anti-tumour activity in certain animal models. Bone mineral affinity is likely to influence the extent of any such effects of these agents on non-osteoclast cells. While alternative anti-resorptive therapeutics are becoming available for clinical use, bisphosphonates currently remain the principle drugs used to treat excessive bone resorption.
-
Accumulating evidence indicates that circulating endothelial progenitor cells (EPCs) derived from bone marrow contribute to reendothelialization of injuried vessels as well as neo-vascularization of ischemic lesions in either a direct or an indirect way. Moreover, the number and/or the functional activity of EPCs are inversely correlated with risk factors for cardiovascular disease. ⋯ In particular, we show the recent observation on the effects of active and second hand smoke (SHS) exposure on EPC number and functional activity. This review also considers the effects of nicotine and other smoke compounds on EPC number and activity, in in vitro and in vivo models.
-
Chemokines and chemokine receptors play diverse roles in homeostasis. The chemokine stromal cell-derived factor 1 (SDF-1) and its receptor CXCR4 have critical functions in the immune, circulatory, and central nervous systems and have also been implicated in tumor biology and metastasis. Here we review the current data regarding the role of the CXCR4/SDF-1 chemokine axis in the development of bone metastases, derived from tumor models of breast or prostate cancers. ⋯ In short, the effects of the CXCR4/SDF-1 axis on tumor cell growth within the bone are not yet fully defined. Further, there are theoretical risks that blockade of this chemokine axis could impair immune function or mobilize tumor cells leading to other sites of metastasis. As such, caution should be taken when designing therapeutic strategies targeting this chemokine axis.
-
Active and passive exposure to cigarette smoke (CS) increases the risk of, and has deleterious effects in, ischaemic heart disease. Exposure to CS increases infarct size in experimental models of coronary occlusion and reperfusion. ⋯ Many, if not all, of these alterations are caused by oxidative stress, either as a direct consequence of inhalation of free radicals, or by induction from the vast range of chemicals present in both the gas and solid phase of tobacco smoke. Here, some of the proposed mechanisms will be reviewed and their impact on the cardiomyocytes and peripheral vasculature discussed.
-
Alzheimer's disease (AD) is the most common neurodegenerative disorder that affects the elderly. The increase of life-expectancy is transforming AD into a major health-care problem. AD is characterized by a progressive impairment of memory and other cognitive skills leading to dementia. ⋯ This review discusses current knowledge about the involvement of neuroinflammation in AD pathogenesis, focusing on phenotypic and functional responses of microglia, astrocytes and neurons in this process. The abnormal production by glia cells of pro-inflammatory cytokines, chemokines and the complement system, as well as reactive oxygen and nitrogen species, can disrupt nerve terminals activity causing dysfunction and loss of synapses, which correlates with memory decline; these are phenomena preceding the neuronal death associated with late stages of AD. Thus, therapeutic strategies directed at controlling the activation of microglia and astrocytes and the excessive production of pro-inflammatory and pro-oxidant factors may be valuable to control neurodegeneration in dementia.