Showing papers in "Current Drug Targets in 2010"
TL;DR: This review serves as one guide for the virtual screening of libraries containing halogenated drugs and their structural and pharmacological features and may be a source of inspiration for the medicinal chemists.
Abstract: A significant number of drugs and drug candidates in clinical development are halogenated structures. For a long time, insertion of halogen atoms on hit or lead compounds was predominantly performed to exploit their steric effects, through the ability of these bulk atoms to occupy the binding site of molecular targets. However, halogens in drug - target complexes influence several processes rather than steric aspects alone. For example, the formation of halogen bonds in ligand-target complexes is now recognized as a kind of intermolecular interaction that favorably contributes to the stability of ligand-target complexes. This paper is aimed at introducing the fascinating versatility of halogen atoms. It starts summarizing the prevalence of halogenated drugs and their structural and pharmacological features. Next, we discuss the identification and prediction of halogen bonds in protein-ligand complexes, and how these bonds should be exploited. Interesting results of halogen insertions during the processes of hit-to-lead or lead-to-drug conversions are also detailed. Polyhalogenated anesthetics and protein kinase inhibitors that bear halogens are analyzed as cases studies. Thereby, this review serves as one guide for the virtual screening of libraries containing halogenated compounds and may be a source of inspiration for the medicinal chemists.
503 citations
TL;DR: Growing evidence points to NF-kappaB signaling as not only playing a central role in the pro-inflammatory stress-related responses of chondrocytes to extra- and intra-cellular insults, but also in the control of their differentiation program.
Abstract: In the context of OA disease, NF-kappaB transcription factors can be triggered by a host of stress-related stimuli including pro-inflammatory cytokines, excessive mechanical stress and ECM degradation products. Activated NF-kappaB regulates the expression of many cytokines and chemokines, adhesion molecules, inflammatory mediators, and several matrix degrading enzymes. NF-kappaB also influences the regulated accumulation and remodeling of ECM proteins and has indirect positive effects on downstream regulators of terminal chondrocyte differentiation (including beta-catenin and Runx2). Although driven partly by pro-inflammatory and stress-related factors, OA pathogenesis also involves a "loss of maturational arrest" that inappropriately pushes chondrocytes towards a more differentiated, hypertrophic-like state. Growing evidence points to NF-kappaB signaling as not only playing a central role in the pro-inflammatory stress-related responses of chondrocytes to extra- and intra-cellular insults, but also in the control of their differentiation program. Thus unlike other signaling pathways the NF-kappaB activating kinases are potential therapeutic OA targets for multiple reasons. Targeted strategies to prevent unwanted NF-kappaB activation in this context, which do not cause side effects on other proteins or signaling pathways, need to be focused on the use of highly specific drug modalities, siRNAs or other biological inhibitors that are targeted to the activating NF-kappaB kinases IKKalpha or IKKbeta or specific activating canonical NF-kappaB subunits. However, work remains in its infancy to evaluate the effects of efficacious, targeted NF-kappaB inhibitors in animal models of OA disease in vivo and to also target these strategies only to affected cartilage and joints to avoid other undesirable systemic effects.
460 citations
TL;DR: By providing comprehensive real-time information, molecular imaging of VEGF pathway may accelerate the drug development process and will be of great help for patient stratification and therapeutic effect monitoring, which will promote effective personalized molecular cancer therapy.
Abstract: New blood vessel formation (angiogenesis) is fundamental to tumor growth, invasion, and metastatic dissemination. The vascular endothelial growth factor (VEGF) signaling pathway plays pivotal roles in regulating tumor angiogenesis. VEGF as a therapeutic target has been validated in various types of human cancers. Different agents including antibodies, aptamers, peptides, and small molecules have been extensively investigated to block VEGF and its pro-angiogenic functions. Some of these agents have been approved by FDA and some are currently in clinical trials. Combination therapies are also being pursued for better tumor control. By providing comprehensive real-time information, molecular imaging of VEGF pathway may accelerate the drug development process. Moreover, the imaging will be of great help for patient stratification and therapeutic effect monitoring, which will promote effective personalized molecular cancer therapy. This review summarizes the current status of tumor therapeutic agents targeting to VEGF and the applications of VEGF related molecular imaging.
276 citations
TL;DR: The role of Notch signaling pathway is described, and how its deregulation is involved in EMT and tumor aggressiveness is cataloged, which could become a novel approach for cancer prevention and treatment.
Abstract: The Notch signaling pathway maintains a balance between cell proliferation and apoptosis, and thus it is believed that Notch signaling pathway may play an important role in the development and progression of several malignancies. However, the functions of Notch signaling in EMT are largely unknown. This mini review describes the role of Notch signaling pathway in EMT, and cataloging how its deregulation is involved in EMT and tumor aggressiveness. Further attempts have been made to summarize the role of several chemopreventive agents that could be useful for targeted inactivation of Notch signaling, and thus it may cause reversal of EMT, which could become a novel approach for cancer prevention and treatment.
275 citations
TL;DR: The consistent miR-21 overexpression under pathophysiological conditions points to miR20 as a valuable tool for new therapeutic strategies and the particular role of miR21 as a therapeutic target in various diseases is highlighted.
Abstract: MicroRNA-21 (miR-21) expression is activated in multiple types of cancers, such as breast, liver, brain, prostate, myometrial cancers but also in cardiovascular diseases. MiR-21 regulates a plethora of target proteins which are involved in cellular survival, apoptosis and cell invasiveness. MiR-21 regulation is complex due to an own promoter that is target for various transcription factors and hormones. The consistent miR-21 overexpression under pathophysiological conditions points to miR-21 as a valuable tool for new therapeutic strategies. In this review, we present and analyze current data about miR-21 expression in various pathologies ranging from cancer to cardiovascular disease. Further, miR-21 regulatory mechanisms and miR-21 downstream targets are discussed. Finally, we highlight the particular role of miR-21 as a therapeutic target in various diseases.
240 citations
TL;DR: The implications of HO-1 properties for tumor proliferation and cell death, differentiation, angiogenesis and metastasis, and tumor-related inflammation are discussed and it is suggested that pharmacological agents that regulate HO activity orHO-1 gene silencing may become powerful tools for preventing the onset or progression of various cancers and sensitize them to anticancer therapies.
Abstract: Heme oxygenase-1 (HO-1) degrades heme to carbon monoxide (CO), biliverdin, and ferrous iron. As HO-1 expression is highly increased by stressful conditions, the major role of the enzyme is the protection against oxidative injury. Additionally, it regulates cell proliferation, modulates inflammatory response and facilitates angiogenesis. Beneficial activities of HO-1 have been recognized in many pathological states e.g. atherosclerosis, diabetes, ischemia/reperfusion injury or organ transplantation. Interestingly HO-1 expression is very often boosted in tumor tissues and could be further elevated in response to radio-, chemo-, or photodynamic therapy. A growing body of evidence suggests that HO-1 may play a role in tumor induction and can potently improve the growth and spread of tumors. This review discusses the implications of HO-1 properties for tumor proliferation and cell death, differentiation, angiogenesis and metastasis, and tumor-related inflammation. Finally, it suggests that pharmacological agents that regulate HO activity or HO-1 gene silencing may become powerful tools for preventing the onset or progression of various cancers and sensitize them to anticancer therapies.
229 citations
TL;DR: Recent findings on the regulation of the HO-1 gene, Hmox1, in the brain with particular focus on the transcription factors Nrf2 and HIF-1 are discussed.
Abstract: Heme oxygenase-1 (HO-1), an enzyme degrading heme to carbon monoxide, free iron, and biliverdin, participates in the cell defence against oxidative stress and it has been speculated that it might be a new therapeutic target for neuroprotection In this review, we discuss recent findings on the regulation of the HO-1 gene, Hmox1, in the brain with particular focus on the transcription factors Nrf2 and HIF-1 Functional polymorphisms in Hmox1 have been associated with high risk for Alzheimer's and Parkinson's disease Hence, we review the current knowledge on the role of HO-1 and its enzymatic products on these two pathologies as well as ischemic brain injury HO-1 modulates the inflammatory response in several scenarios, and therefore we discuss its role in modulation of the innate immune cell of the brain, microglia From the therapeutic side, the blood brain barrier represents an obstacle to directly modulate heme oxygenase activity, but drugs activating the transcription actor Nrf2, which have a very diverse molecular structure, may be good candidates to induce HO-1 in concert with other antioxidant and detoxification enzymes A more complete understanding on the mechanisms regulating HO-1 expression in brain cells and how these mechanisms are involved in neuropathological changes will be essential to develop these new therapeutic approaches
190 citations
TL;DR: This review summarizes the most recent studies pertaining to the mechanisms by which proinflammatory cytokines promote breast cancer and the possibilities of targeting these inflammatory mediators in breast cancer patients using inhibitors that are currently being used in the clinic for other inflammatory conditions.
Abstract: Inflammation within the tumor microenvironment correlates with increased invasiveness and poor prognosis in many types of cancer, including breast cancer. The cytokines interleukin-6 (IL-6), tumor necrosis factor alpha (TNFalpha) and interleukin-1 beta (IL-1beta) are critical mediators of the inflammatory response. Numerous studies have also linked these cytokines to breast cancer progression. As a result, the mechanisms by which these cytokines promote breast cancer have been recently explored using both in vitro and in vivo models. The results from these studies have led to speculation regarding the possible usefulness of targeting these cytokines in breast cancer patients. This review summarizes the most recent studies pertaining to the mechanisms by which proinflammatory cytokines promote breast cancer. Furthermore, the possibilities of targeting these inflammatory mediators in breast cancer patients using inhibitors that are currently being used in the clinic for other inflammatory conditions are discussed. Understanding both the mechanisms by which inflammatory mediators promote breast cancer and the effectiveness of anti-inflammatory drugs in treating breast cancer will lead to novel therapeutic regimens to treat this devastating disease.
190 citations
TL;DR: The evidences that link the 'metabolic syndrome' with increased risk for developing AD are resumed and the major changes occurring on both extra-mitochondrial and mitochondrial metabolic pathways are revisited, as revealed by imaging studies and biochemical analysis of brain and peripheral samples obtained from AD patients.
Abstract: Alzheimer's disease (AD) is the most common form of dementia in old age. Cognitive impairment in AD may be partially due to overall hypometabolism. Indeed, AD is characterized by an early region-specific decline in glucose utilization and by mitochondrial dysfunction, which have deleterious consequences for neurons through increased production of reactive oxygen species (ROS), ATP depletion and activation of cell death processes. In this article, we provide an overview of the alterations on energetic metabolism occurring in AD. First, we resume the evidences that link the 'metabolic syndrome' with increased risk for developing AD and revisit the major changes occurring on both extra-mitochondrial and mitochondrial metabolic pathways, as revealed by imaging studies and biochemical analysis of brain and peripheral samples obtained from AD patients. We also cover the recent findings on cellular and animal models that highlight mitochondrial dysfunction as a fundamental mechanism in AD pathogenesis. Recent evidence posits that mitochondrial abnormalities in this neurodegenerative disorder are associated with changes in mitochondrial dynamics and can be induced by amyloid-beta (Aβ) that progressively accumulates within this organelle, acting as a direct toxin. Furthermore, Aβ induces activation of glutamate N-methyl-D-aspartate receptors (NMDARs) and/or excessive release of calcium from endoplasmic reticulum (ER) that may underlie mitochondrial calcium dyshomeostasis thereby disturbing organelle functioning and, ultimately, damaging neurons. Throughout the review, we further discuss several therapeutic strategies aimed to restore neuronal metabolic function in cellular and animal models of AD, some of which have reached the stage of clinical trials.
162 citations
TL;DR: Progress in the preclinical development of CDK inhibitors and their anticancer activities is reported, and the links between their ability to inhibit transcription and sensitisation of some types of cancer to apoptosis, mechanisms leading to p53 activation, and their synergistic cooperation with common DNA damaging drugs are discussed.
Abstract: Poor therapeutic outcomes and serious side effects, together with acquired resistance to multiple drugs, are common problems of current cancer therapies. Therefore, there is an urgent need for new cancer-targeted drugs, which has led (inter alia) to the development of molecules that can specifically inhibit cyclin-dependent kinases (CDKs). In addition to their cell cycle regulatory functions, CDKs, especially CDK7 and CDK9, play important roles in the regulation of RNA polymerase II-mediated transcription. Here, we report on progress in the preclinical development of CDK inhibitors and their anticancer activities. Special attention is paid to the action mechanisms of the pan-specific CDK inhibitors flavopiridol and roscovitine, which have already entered phase II clinical trials as treatments for various tumours. The links between their ability to inhibit transcription and sensitisation of some types of cancer to apoptosis, mechanisms leading to p53 activation, and their synergistic cooperation with common DNA damaging drugs are also discussed. It has been demonstrated that drug-resistant cancer cells can arise during therapeutic application of small molecule protein kinase inhibitors. Clinical resistance to CDK inhibitors has not yet been described, but by comparing CDKs to other kinases, and CDK inhibitors to other clinically used protein kinase inhibitors, we also discuss possible mechanisms that could lead to resistance to CDK inhibitors.
140 citations
TL;DR: The physiological roles of Co Q10 are reviewed, as well as the rationale and the role in clinical practice of CoQ10 supplementation in different neurological and muscular diseases, from primary CoQ 10 deficiency to neurodegenerative disorders are reviewed.
Abstract: Coenzyme Q10 (CoQ10, or ubiquinone) is an electron carrier of the mitochondrial respiratory chain (electron transport chain) with antioxidant properties. In view of the involvement of CoQ10 in oxidative phosphorylation and cellular antioxidant protection a deficiency in this quinone would be expected to contribute to disease pathophysiology by causing a failure in energy metabolism and antioxidant status. Indeed, a deficit in CoQ10 status has been determined in a number of neuromuscular and neurodegenerative disorders. Primary disorders of CoQ10 biosynthesis are potentially treatable conditions and therefore a high degree of clinical awareness about this condition is essential. A secondary loss of CoQ10 status following HMG-Coa reductase inhibitor (statins) treatment has be implicated in the pathophysiology of the myotoxicity associated with this pharmacotherapy. CoQ10 and its analogue, idebenone, have been widely used in the treatment of neurodegenerative and neuromuscular disorders. These compounds could potentially play a role in the treatment of mitochondrial disorders, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, Friedreich's ataxia, and other conditions which have been linked to mitochondrial dysfunction. This article reviews the physiological roles of CoQ10, as well as the rationale and the role in clinical practice of CoQ10 supplementation in different neurological and muscular diseases, from primary CoQ10 deficiency to neurodegenerative disorders. We also briefly report a case of the myopathic form of CoQ10 deficiency.
TL;DR: The efficacy of these terpenoids against breast or prostate cancer cells, as demonstrated in pre-clinical studies support clinical application of these naturally occurring terpenoid in treatment of hormone-related human cancers.
Abstract: Terpenoids represent a large and diverse class of naturally occurring compounds found in a variety of fruits, vegetables and medicinal plants. Structurally some of the terpenoids are similar to human hormones. A diet rich in terpenoids is inversely related with the risk of chronic diseases including cancers. Breast and prostate cancers are hormone-related diseases and the second leading cause of female and male cancer mortality. Diterpenoid paclitaxel, and its semi-synthetic analogue docetaxel, have entered clinical use against established breast and prostate cancers. Here we reviewed potential molecular targets and biological properties of natural terpenoids, including monoterpenoids, diterpenoids, triterpenoids and tetraterpenoids, and their applications in treatment of human breast and prostate cancers. These terpenoids are able to inhibit tumor cell proliferation and induce tumor cell death by inhibiting multiple cancer-specific targets including the proteasome, NF-kappaB, and antiapoptotic protein Bcl-2. The efficacy of these terpenoids against breast or prostate cancer cells, as demonstrated in pre-clinical studies support clinical application of these naturally occurring terpenoids in treatment of hormone-related human cancers.
TL;DR: Since HO-1 and its products are potentially toxic, a major challenge will be to devise clinically effective therapeutic modalities that targetHO-1 without causing any adverse effects.
Abstract: Heme oxygenase-1 (HO-1) metabolizes heme to generate carbon monoxide (CO), biliverdin, and iron. Biliverdin is subsequently metabolized to bilirubin by biliverdin reductase. HO-1 has recently emerged as a promising therapeutic target in the treatment of vascular disease. Pharmacological induction or gene transfer of HO-1 ameliorates vascular dysfunction in animal models of atherosclerosis, post-angioplasty restenosis, vein graft stenosis, thrombosis, myocardial infarction, and hypertension, while inhibition of HO-1 activity or gene deletion exacerbates these disorders. The vasoprotection afforded by HO-1 is largely attributable to its end products: CO and the bile pigments, biliverdin and bilirubin. These end products exert potent anti-inflammatory, antioxidant, anti-apoptotic, and anti-thrombotic actions. In addition, CO and bile pigments act to preserve vascular homeostasis at sites of arterial injury by influencing the proliferation, migration, and adhesion of vascular smooth muscle cells, endothelial cells, endothelial progenitor cells, or leukocytes. Several strategies are currently being developed to target HO-1 in vascular disease. Pharmacological induction of HO-1 by heme derivatives, dietary antioxidants, or currently available drugs, is a promising near-term approach, while HO-1 gene delivery is a long-term therapeutic goal. Direct administration of CO via inhalation or through the use of CO-releasing molecules and/or CO-sensitizing agents provides an attractive alternative approach in targeting HO-1. Furthermore, delivery of bile pigments, either alone or in combination with CO, presents another avenue for protecting against vascular disease. Since HO-1 and its products are potentially toxic, a major challenge will be to devise clinically effective therapeutic modalities that target HO-1 without causing any adverse effects.
TL;DR: Current understanding on the state of anti-cancer research involving indole compounds is attempted, which summarized the available literature on modulatory effects of indoles on molecular targets such as survivin, uPA/uPAR and signaling pathways such as the NF-kappaB pathway, which are important for the apoptosis-inducing and chemosensitizing properties of these compounds.
Abstract: Indole compounds, obtained from cruciferous vegetables, have been investigated for their putative anti-cancer properties. Studies with indole-3-carbinol (I3C) and its dimeric product, 3, 3' diindolylmethane (DIM), have indicated efficacy of these compounds against a number of human cancers. Available as well as emerging data suggests that these compounds act on a number of cellular signaling pathways leading to their observed biological effects. Such pleiotropic effects of these compounds are also considered crucial for their chemosensitization activity wherein they help reduce the toxicity and resistance against conventional chemotherapeutic drugs. These observations have major clinical implications especially in chemotherapy. Through this review, we have attempted to update current understanding on the state of anti-cancer research involving indole compounds. We have also summarized the available literature on modulatory effects of indoles on molecular targets such as survivin, uPA/uPAR and signaling pathways such as the NF-kappaB pathway, which are important for the apoptosis-inducing and chemosensitizing properties of these compounds.
TL;DR: This review will provide an overview of the current understanding of Wnt/beta-catenin pathway involvement in regulating normal breast development and morphogenesis, the generation of WNT/ Beta-Catenin-dependent GEM models of human breast cancer, upregulation of signaling in human breast cancers and the compelling therapeutic strategies aimed at targeting the Wnt / beta-catanin pathway that show promising anti-tumor activity.
Abstract: Aberrant activation of the Wnt/beta-catenin signaling pathway is a hallmark of many tumors, including breast cancer. In the normal breast, tightly regulated expression of Wnt/beta-catenin pathway components, including Wnts and the APC tumor suppressor, dictates its role in balancing stem cell self-renewal, maintenance and differentiation during embryonic and postnatal development. Therefore, not surprisingly, dysregulation of Wnt/beta-catenin signaling through overexpression of pathway activators, such as Wnts or stabilized beta-catenin, or targeted disruption of inhibitors, such as APC, leads to mammary tumorigenesis in several genetically engineered mouse (GEM) models. These models are powerful tools to dissect the importance of Wnt/beta-catenin signaling in human breast cancer because they recapitulate some of the histological features of human breast cancers that demonstrate pathway dysregulation. Over the last decade, numerous approaches have been developed to target the Wnt/beta-catenin pathway in tumor cells, from antagonizing Wnt ligand secretion or binding to promoting beta-catenin degradation to specifically blocking beta-catenin-mediated transcriptional activity. Despite sizeable hurdles because of gaps in our knowledge of most efficacious ways to inhibit the pathway, the breast cancer subtypes to target and how pathway antagonists might be used in combination therapy, crippling Wnt/beta-catenin signaling offers a tremendous opportunity to impact breast cancer pathogenesis. This review will provide an overview of the current understanding of Wnt/beta-catenin pathway involvement in regulating normal breast development and morphogenesis, the generation of Wnt/beta-catenin-dependent GEM models of human breast cancer, upregulation of signaling in human breast cancers and the compelling therapeutic strategies aimed at targeting the Wnt/beta-catenin pathway that show promising anti-tumor activity.
TL;DR: Current technology allows us to propose likely targets that are either currently being researched or should be considered in future studies, and this work concludes that lung normal tissue late effects are likely targets for dose-limiting treatment.
Abstract: Due to the radiosensitivity of the lung, toxic endpoints, in the form of radiation pneumonitis and pulmonary fibrosis, are relatively frequent outcomes following radiation treatment of thoracic neoplasms Because of the potential lethal nature of these normal tissue reactions, they not only lead to quality-of-life issues in survivors, but also are deemed dose-limiting and thereby compromise treatment The mitigation and treatment of lung normal tissue late effects has therefore been the goal of many investigations; however, the complexity of both the organ itself and its response to injury has resulted in little success Nonetheless, current technology allows us to propose likely targets that are either currently being researched or should be considered in future studies
TL;DR: Treatment options for the normalisation of adipokine levels are summarised, which might confer an additional clinical benefit in the effort to prevent or treat obesity-related T2DM and CVD.
Abstract: White adipose tissue (WAT) is an important endocrine organ that secretes approximately 30 biologically active peptides and proteins, collectively termed “adipokines”. These are either produced exclusively by WAT (mainly adiponectin, leptin and resistin) or also by other tissues [e.g. tumour necrosis factor (TNF)-alpha, interleukin (IL)-6, plasminogen activator inhibitor (PAI)-1, angiotensinogen]. Adipokines play a central role in body homeostasis including the regulation of food intake and energy balance, insulin action, lipid and glucose metabolism, angiogenesis and vascular remodelling, regulation of blood pressure and coagulation. Excess WAT, especially visceral obesity, is linked to obesityrelated health problems through insulin resistance (IR) [leading to type 2 diabetes mellitus (T2DM)] and systemic lowgrade inflammation [leading to cardiovascular disease (CVD)]. The adipokines are important mediators of these adverse effects. This review describes the role of proinflammatory adipokines in the pathogenesis of IR and of the chronic inflammatory state associated with visceral obesity. Moreover, it summarises treatment options for the normalisation of adipokine levels, which might confer an additional clinical benefit in the effort to prevent or treat obesity-related T2DM and CVD.
TL;DR: In this scenario, where the influence of obesity on OA stems from a complex interaction of genetic, metabolic, neuroendocrine, and biomechanical factors, there may be various different potential targets for OA therapy.
Abstract: Obesity is one of the main risk factors for osteoarthritis (OA). For many years the association of obesity and OA has been simply attributed to the effects of overload on weight-bearing joints, and epidemiological surveys have shown a strict correlation between an increased body mass index and the severity of knee or hip OA, as well as some relief of pain and disability following weight loss. Instead, there is now a growing body of evidence that obesity is a complex syndrome in which an abnormal activation of neuroendocrine and pro-inflammatory pathways leads to an altered control of food intake, fat expansion and metabolic changes. Activated white adipose tissue increases the synthesis of pro-inflammatory cytokines, such as IL-6, IL-1, IL-8, TNFalpha, IL-18, while regulatory cytokines, such as IL-10, are decreased. Adipocytes also produce peculiar cytokines, namely adipokines, that exert multiple effects, being capable of promoting synovial inflammation, cartilage degrading enzymes, and bone matrix remodeling. Furthermore, pro-inflammatory cytokines stimulate adipocytes to synthesize neuropeptides, such as substance P and nerve growth factor, that have been shown to be critical in regulating both the appetite and cartilage homeostasis. In this scenario, where the influence of obesity on OA stems from a complex interaction of genetic, metabolic, neuroendocrine, and biomechanical factors, there may be various different potential targets for OA therapy.
TL;DR: The inhibition of TAGE formation, blockade of Tage-RAGE interaction, and the suppression of RAGE expression or its downstream pathways are promising targets for therapeutic interventions against diabetic vascular complications.
Abstract: Diabetic vascular complications are leading causes of acquired blindness, end-stage renal failure, a variety of neuropathies, and accelerated atherosclerosis, which may be involved in the disabilities and high mortality rates suffered by diabetic patients. Continuous hyperglycemia is involved in the pathogenesis of diabetic micro- and macrovascular complications via various metabolic pathways, and numerous hyperglycemia-induced metabolic and hemodynamic conditions exist, including increased generation of various types of advanced glycation end-products (AGEs). Recently, we demonstrated that glyceraldehyde-derived AGEs (Glycer-AGEs), the predominant components of toxic AGEs (TAGE), play an important role in the pathogenesis of angiopathy in diabetic patients. Moreover, a growing body of evidence suggests that the interaction of TAGE with the receptor for AGEs (RAGE) alters intracellular signaling, gene expression, and the release of pro-inflammatory molecules and elicits oxidative stress generation in numerous types of cells, all of which may contribute to the pathological changes observed in diabetic vascular complications. Therefore, the inhibition of TAGE formation, blockade of TAGE-RAGE interaction, and the suppression of RAGE expression or its downstream pathways are promising targets for therapeutic interventions against diabetic vascular complications. In this review, we discuss the pathophysiological role of the TAGE-RAGE-oxidative stress system and related therapeutic interventions for preventing the development and progression of diabetic vascular complications.
TL;DR: Recent findings on the therapeutic applications of HO-1 and its end-product CO in the lung are summarized, with an emphasis on lung injury models relevant to critical care medicine.
Abstract: Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) remain major causes of morbidity and mortality in critical care medicine despite advances in therapeutic modalities. ALI can be associated with sepsis, trauma, pharmaceutical or xenobiotic exposures, high oxygen therapy (hyperoxia) and mechanical ventilation. The stress protein heme oxygenase-1 (HO-1) provides an inducible defense mechanism that can protect lung cells and tissues against injury. HO-1 degrades heme to biliverdin-IXalpha, carbon monoxide (CO), and iron. Each of these reaction products has been implicated in the cytoprotection associated with HO-1 expression. At low concentrations, CO can confer cyto-protective and tissue-protective effects involving the inhibition of inflammatory, proliferative, and apoptotic signaling. Lung protection by HO-1 has been demonstrated in vitro and in vivo in several models of experimental ALI and sepsis. Recent studies have also explored the protective effects of pharmacological or inhalation CO therapy in animal models of ALI/sepsis. CO has shown therapeutic potential in models of oxidative and acid-induced lung injury, ventilator-induced lung injury, endotoxin challenge, and cecal-ligation and puncture induced-sepsis. Despite therapeutic benefit in animal model studies, the efficacy of CO in humans with these conditions remains unclear, and awaits further controlled clinical studies. This review will summarize recent findings on the therapeutic applications of HO-1 and its end-product CO in the lung, with an emphasis on lung injury models relevant to critical care medicine.
TL;DR: This review will focus on the discovery and biological evaluation of the plant-derived agent silvestrol, which shows potential for additional development as a new therapeutic agent for B-cell malignancies including chronic lymphocytic leukemia.
Abstract: Hematologic malignancies account for a substantial percentage of cancers worldwide, and the heterogeneity and biological characteristics of leukemias and lymphomas present unique therapeutic challenges. Although treatment options exist for most of these diseases, many types remain incurable and the emergence of drug resistance is pervasive. Thus, novel treatment approaches are essential to improve outcome. Nearly half of the agents used in cancer therapy today are either natural products or derivatives of natural products. The enormous chemical diversity in nature, coupled with millennia of biological selection, has generated a vast and underexplored reservoir of unique chemical structures with biologic activity. This review will describe the investigation and application of natural products derived from higher plants in the treatment of leukemia and lymphoma and the rationale behind these efforts. In addition to the approved vinca alkaloids and the epipodophyllotoxin derivatives, a number of other plant compounds have shown promise in clinical trials and in preclinical investigations. In particular, we will focus on the discovery and biological evaluation of the plant-derived agent silvestrol, which shows potential for additional development as a new therapeutic agent for B-cell malignancies including chronic lymphocytic leukemia.
TL;DR: Recent developments in application of evolutionary algorithms to molecular docking simulations and application of MolDock to purine nucleoside phosphorylase, shikimate kinase and cyclin-dependent kinase 2 are described.
Abstract: Molecular docking is a simulation process where the binding of a small molecule is identified in the structure of a protein target. There are several different computational approaches to solve this problem. Here it will be described recent developments in application of evolutionary algorithms to molecular docking simulations. Evolutionary algorithms are classified as a group of computational techniques based on the concepts of Darwin's theory of evolution that are designed to the best possible find solution to optimisation problems. A successfully implementation of this algorithm can be found in the program MolDock. The main features of MolDock are reviewed here we also describe application of MolDock to purine nucleoside phosphorylase, shikimate kinase and cyclin-dependent kinase 2.
TL;DR: New strategies and methods to design more potent, selective and specific CDK inhibitors are discussed, starting from evidence emerging from animal and cancer cell models.
Abstract: Cell cycle deregulation is one of the first steps that transform normal cells into tumor cells. CDKs are a family of proteins devoted to controlling cell cycle entry, progression and exit. Studies from animal models show a tissue-specific essentiality of the single CDKs. In cancer cells, mis-regulation of CDK function is a common event. For this reason the pioneer compound Flavopiridol was developed and many new drugs are currently under development. ATP and the last generation of non-ATP competitive inhibitors are now emerging as one of the most potentially powerful target therapies. Many clinical trials are ongoing, as either a single agent or in combination with the classical cytotoxic agents. In this review, we discuss new strategies and methods to design more potent, selective and specific CDK inhibitors, starting from evidence emerging from animal and cancer cell models.
TL;DR: Recent progress in understanding of Osteopontin's role in variety of inflammatory disorders is summarized.
Abstract: It has been well recognized that inflammatory responses are part of pathogenesis for various disorders such as autoimmune diseases. For example, multiple sclerosis (MS) is an inflammatory demyelinating disease of central nervous system that is presumably caused by activated T cells specific for myelin antigens. Rheumatoid arthritis (RA) is also a chronic inflammatory disease characterized by synovial inflammation in which several inflammatory cytokines are involved. On the other hand, Osteopontin (Opn) is a pleiotropic cytokine expressed by activated T cells, dendritic cells (DCs) and macrophages and its expression is up-regulated during inflammation. Secreted form of Opn (s-Opn), which is modified by phosphorylation, glycosylation and proteolytic cleavage with thrombin, has activities as a T helper type 1 (Th1) cytokine and as a chemoattractant for many types of cells through integrin receptors and CD44. Recently, it has been uncovered that intracellular form of Opn (i-Opn) is a critical regulator for Toll like receptor-9 (TLR-9), TLR-7-dependent interferon-alpha (IFN-alpha) expression by plasmacytoid DCs and Th17 development. In this review, we have summarized recent progress in understanding of Opn's role in variety of inflammatory disorders.
TL;DR: The future may lie in targeting multiple steps of the apoptotic pathway, including Bcl-2/xL/Mcl-1, to debilitate the survival capacity of cancer cells and make chemotherapy induced death their only option.
Abstract: A major challenge in oncology is the development of chemoresistance. This often occurs as cancer progresses and malignant cells acquire mechanisms to resist insults that would normally induce apoptosis. The onset of androgen independence in advanced prostate cancer is a prime example of this phenomenon. Overexpression of the pro-survival/anti-apoptotic proteins Bcl-2, Bcl-xL, and Mcl-1 are hallmarks of this transition. Here we outline the evolution of therapeutics designed to either limit the source or disrupt the interactions of these pro-survival proteins. By either lessening the stoichiometric abundance of Bcl-2/xL/Mcl-1 in reference to their pro-apoptotic foils or freeing these pro-apoptotic proteins from their grip, these treatments aim to sensitize cells to chemotherapy by priming cells for death. DNA anti-sense and RNA interference have been effectively employed to decrease Bcl-2 family mRNA and protein levels in cell culture models of advanced prostate cancer. However, clinical studies are lagging due to in vivo delivery challenges. The burgeoning field of nanoparticle delivery holds great promise in helping to overcome the challenge of administering highly labile nucleic acid based therapeutics. On another front, small molecule inhibitors that block the hetero-dimerization of pro-survival with pro-apoptotic proteins have significant clinical advantages and have advanced farther in clinical trials with promising early results. Most recently, a peptide has been discovered that can convert Bcl-2 from a pro-survival to a pro-apoptotic protein. The future may lie in targeting multiple steps of the apoptotic pathway, including Bcl-2/xL/Mcl-1, to debilitate the survival capacity of cancer cells and make chemotherapy induced death their only option.
TL;DR: Given the importance of the delicately orchestrated immune response in atherosclerosis and arterial remodelling, miRs will exert profound effects during the evolution of lesion formation and constitute possible targets for therapeutic interventions.
Abstract: Atherosclerosis is now widely appreciated to represent a chronic inflammatory reaction of the vascular wall in response to dyslipidemia and endothelial distress involving the inflammatory recruitment of leukocytes and the activation of resident vascular cells. The proliferative response of smooth muscle cells critically contributes to arterial remodelling. As part of the inflammatory infiltrate, monocytes/macrophages, but also dendritic cells, lymphocytes and neutrophils contribute to the pathogenesis of atherosclerosis. The analysis of microRNA (miR) expression in arterial lesions after balloon injury has revealed fundamental changes in the miR signature comprising many different miRs. Moreover, single miRs have been pinpointed to exert a significant impact on neointimal lesion formation. While studies addressing the profile of miR expression during the development of native atherosclerotic plaques are ongoing, it is conceivable that miRs expressed in inflammatory cell subsets would also affect disease progression. Here we summarize the role of miRs in arterial remodelling and atherosclerosis and putative roles of miRs in vascular inflammation by regulating the differentiation and functions of immune cell subsets. Given the importance of the delicately orchestrated immune response in atherosclerosis and arterial remodelling, miRs will exert profound effects during the evolution of lesion formation and constitute possible targets for therapeutic interventions.
TL;DR: Identifying more down stream Wnt signaling effector molecules, like WISP-1, for more specific therapy promises to be a safer and more efficient approach to find a treatment for this disease that heavily constrains millions of people each year.
Abstract: Recent evidence from animal experiments and clinical samples points at a role for Wnt-signaling in osteoarthritis (OA) pathology. These pathways are key inducers and regulators of joint development, and are involved in formation of bone, cartilage and also synovium. Disregulation of members from this pathways have been described in OA. This makes the Wnt-family of proteins and signaling pathways an attractive target for therapy. Although knowledge is increasing rapidly it is still a challenge to decide on the best approach in targeting Wnt signaling. Activation of the canonical signaling pathway, which features intra-cellular accumulation of beta-catenin, is most often implicated in recent studies in OA pathology, in experimental OA and spondyloarthritis. However, direct targeting of beta-catenin is anticipated to be too hazardous, because of its importance for the maintenance of stability of articular chondrocyte phenotype and because of its proven role in carcinogenesis. A more attractive approach will be identifying the misexpression of specific Wnt-proteins or their inhibitors in various tissues that are important in OA, bone, cartilage and synovium, to point out targets for therapy. For example, recently it was shown that Wnt16 is strongly upregulated in cartilage after injury and in synovium in experimental OA, and the expression of this canonical Wnt may be responsible for OA-like changes. Alternatively, identifying more down stream Wnt signaling effector molecules, like WISP-1, for more specific therapy promises to be a safer and more efficient approach to find a treatment for this disease that heavily constrains millions of people each year.
TL;DR: The HO-1 system is a powerful endogenous defense strategy with immense therapeutic potential against a range of lung diseases if optimal levels and tissue targeting can be achieved.
Abstract: The lungs are a major target for various inflammatory, oxidative, carcinogenic or infectious stressors, which result in a range of lung diseases. Induction of heme oxygenase-1 (HO-1) during acute and chronic lung processes is a crucial defense mechanism. HO-1 catalyzes the degradation of free cellular heme to iron, carbon monoxide (CO) and biliverdin which is eventually converted to bilirubin by biliverdin reductase. In addition to the degradation of free heme, a pro-oxidant, HO-1 exerts anti-oxidant, anti-inflammatory and anti-apoptotic properties via its reaction products. This review summarizes the regulation and protective roles of HO-1 and its reaction products in several in vitro and in vivo lung disease models, including acute lung injury, ischemia-reperfusion (IR)-induced lung injury, cigarette smoke and chronic obstructive pulmonary disease (COPD), pulmonary arterial hypertension (PAH), lung cancer and asthma. The therapeutic applications of HO-1 in the lung as well as potential complications of excessive HO-1 induction are also covered. In summary, the HO-1 system is a powerful endogenous defense strategy with immense therapeutic potential against a range of lung diseases if optimal levels and tissue targeting can be achieved.
TL;DR: The merits of various, structurally-distinct HDAC inhibitors as potential anti-inflammatory therapeutics are discussed and examples of the novel medicinal chemistry approaches being undertaken to realize HDAC as a druggable target in this clinical setting are provided.
Abstract: The development of Histone Deacetylase (HDAC) inhibitors has, until recently, principally been driven by their potential as anti-cancer agents. However, there is emerging evidence that HDAC inhibitors could have utility in the treatment of chronic immune and inflammatory disorders, including rheumatoid arthritis, psoriasis, inflammatory bowel disease, multiple sclerosis, systemic lupus erythematosus, airway hyperresponsiveness and organ transplant rejection. Here we discuss the merits of various, structurally-distinct HDAC inhibitors as potential anti-inflammatory therapeutics and provide examples of the novel medicinal chemistry approaches being undertaken to realize HDAC as a druggable target in this clinical setting.
TL;DR: This narrative review outlines the work done in other fields with regards biomarker validation and qualification and poses some logical next steps that will take us in this direction.
Abstract: This narrative review outlines the work done in other fields with regards biomarker validation and qualification and the lessons that we may learn from this experience. Defining a universally agreed upon path for biomarker validation and qualification is urgently needed to circumvent many of the hurdles faced in OA therapeutic development irrespective of whether we are discussing biochemical markers, imaging markers or other measures. This review proposes a path that may be suitable for osteoarthritis and poses some logical next steps that will take us in this direction.