Emerging targets for COPD therapy

No currently available treatments reduce the progression of COPD or suppress the inflammation in small airways and lung parenchyma. However, several new treatments that target the inflammatory process are in clinical development. A group of specific therapies are directed against the influx of inflammatory cells into the airways and lung parenchyma that occurs in COPD; these include adhesion molecule and chemokine-directed therapy, as well as therapies to combat tumour necrosis factor-alpha and augment interleukin-10. Broad spectrum anti-inflammatory drugs are now in phase III development for COPD, and include phosphodiesterase-4 inhibitors. Other drugs that inhibit cell signalling include inhibitors of p38 mitogen-activated protein kinase, nuclear factor-kappaB and phosphoinositide-3 kinase-gamma. More specific approaches are to give antioxidants, inhibitors of inducible nitric oxide synthase, and leukotriene B4 receptor antagonists. Epidermal growth factor receptor kinase inhibitors and calcium-activated chloride channel inhibitors have potential to combat mucus overproduction. Therapy to inhibit fibrosis is being developed against transforming growth factor-beta1 and protease activated receptor-2. There is also a search for serine proteinase and matrix metalloproteinase inhibitors to prevent lung destruction and the development of emphysema, as well as drugs such as retinoids that may even reverse this process. Effective delivery of drugs to the sites of disease in the peripheral lung is an important consideration, and there is the need for validated biomarkers and monitoring techniques in early clinical studies with new therapies for COPD.     

Emerging drug targets for pain treatment

In eukaryotes, many translation inhibitors have been widely used as bioprobes to evaluate the contribution of translation to signaling pathways and cellular functions. Several types of translation inhibitors are also known to trigger the activation of the mitogen-activated protein kinase superfamily in an intracellular mechanism called ribotoxic stress response. This perspective focuses on the biological properties of recently identified translation inhibitors that trigger ribotoxic stress response, particularly glutarimides as well as triene-ansamycins.     

Emerging targets for novel therapy of asthma

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Emerging migraine treatments and drug targets

Migraine has a 1-year prevalence of 10% and high socioeconomic costs. Despite recent drug developments, there is a huge unmet need for better pharmacotherapy. In this review we discuss promising anti-migraine strategies such as calcitonin gene-related peptide (CGRP) receptor antagonists and 5-hydroxytrypamine (5-HT)(1F) receptor agonists, which are in late-stage development. Nitric oxide antagonists are also in development. New forms of administration of sumatriptan might improve efficacy and reduce side effects. Botulinum toxin A has recently been approved for the prophylaxis of chronic migraine. Tonabersat, a cortical spreading depression inhibitor, has shown efficacy in the prophylaxis of migraine with aura. Several new drug targets such as nitric oxide synthase, the 5-HT(1D) receptor, the prostanoid receptors EP(2) and EP(4), and the pituitary adenylate cyclase receptor PAC1 await development. The greatest need is for new prophylactic drugs, and it seems likely that such compounds will be developed in the coming decade.     

Emerging host cell targets for hepatitis C therapy

Chronic hepatitis C virus (HCV) infection is a major burden on humanity. The current HCV therapy has limited efficacy, and there is pressing need for new and more effective therapies. Host cell factors that are required for HCV infection, replication and/or pathogenesis represent potential therapeutic targets. Of particular interest are cellular receptors that mediate HCV entry, factors that facilitate HCV replication and assembly, and intracellular pathways involving lipid biosynthesis, oxidative stress and innate immune response. A crucial challenge now is to manipulate such cellular targets pharmacologically for chronic HCV treatment, without being limited by side effects.     

Emerging drug toxicities of highly active antiretroviral therapy for human immunodeficiency virus (HIV) infection

To provide an overview of the epidemiologic parameters of emerging adverse effects associated with antiretroviral therapy for human immunodeficiency virus (HIV) disease. All available antiretroviral agents are associated with significant adverse drug effects. Of particular interest are newly emerging suspected adverse drug effects which were not generally noted in pre-marketing trials nor captured under current standard clinical care practices. Suspected antiretroviral toxicities meeting these criteria include: HIV-associated lipodystrophy which can include peripheral lipoatrophy, lipohypertrophy and metabolic abnormalities; hyperlactatemia and lactic acidosis; and metabolic bone abnormalities such as decreased bone mineral density, osteoporosis and osteonecrosis. Results of prospective and observational studies reported to date suggest that these abnormalities, while aetiologically complex, are likely attributable to treatment factors and may be intricately interrelated. The medical management of these symptoms remains unsatisfactory given the unexplored efficacy of traditional approaches in the HIV positive population. While the pathogenic mechanism of these disorders remains obscure, a theory of tissue-specific mitochondrial toxicity has been proposed. With the continued introduction of novel therapies and standard treatment with combination therapy, new adverse events will continue to emerge among persons being treated for HIV disease. Beyond their immediate clinical implications, these events may contribute to changing patterns of antiretroviral utilisation including therapy initiation, adherence and cessation.     

Emerging drugs and drug targets against tuberculosis

Mycobacterium tuberculosis (M. tuberculosis), the causative agent of tuberculosis, uses various tactics to resist on antibiotics and evade host immunity. To control tuberculosis, antibiotics with novel mechanisms of action are urgently needed. Emerging new antibiotics and underlying novel drug targets are summarized in this paper.     

Polymeric nanoparticles for enhancing antiretroviral drug therapy

There is a surge of interest internationally in the study of nanoparticles for enhancing antiretroviral (ARV) drug therapy. This paper presents a comprehensive review on polymeric nanoparticles for ARV drug therapy. Their main applications for targeting to macrophages and the brain, as well as other studies on modifications to enhance drug loading, decrease toxicity, and also to increase drug absorption are reviewed. The physicochemical characterization properties and their in vitro/in vivo performances are summarized. Further studies that need to be undertaken for formulation optimization are also identified. This review highlights the significant potential that nanoparticles have for the future effective treatment of HIV/AIDS patients on ARV drug therapy.     

New drug targets for cholera therapy

Intestinal infection with Vibrio cholerae results in secretory diarrhea with potentially massive fluid losses and volume depletion. Morbidity and mortality associated with cholera remain a major problem in the developing world despite the success of oral rehydration therapy. New research aiming to inhibit cholera toxin binding to receptors in the intestine provides an attractive strategy for cholera therapy. Together with anti-secretory agents, including inhibitors of enkephalinase and of the cystic fibrosis transmembrane conductance regulator, new treatment options for managing severe diarrhea in cholera could soon be available.     

Notch signaling: Emerging molecular targets for cancer therapy

The Notch signaling pathway is a highly conserved developmental pathway, which plays a critical role in cell-fate decision, tissue patterning and morphogenesis. There is increasing evidence that this pathway is dysregulated in a variety of malignancies, and can behave as either an oncogene or a tumor suppressor depending upon cell context. This review highlights the current evidence for aberration of the Notch signaling pathway in a wide range of tumors from hematological cancers, such as leukemia and lymphoma through to skin, breast, lung, pancreas, colon and brain tumors. It proposes that the Notch signaling pathway may represent novel therapeutic targets and will be a welcome asset to the cancer therapeutic arena.     

Emerging immune targets for the therapy of allergic asthma

Recent discoveries on the molecular and cellular basis of asthma have markedly altered our understanding of this common respiratory disorder. These insights have come during an unexplained period of rising disease incidence and severity and are now being applied to develop improved therapies. This review explores the latest advances in our understanding of the pathogenesis of allergic asthma, and provides insight into the expanding collaborations between research scientists, clinicians and the pharmaceutical industry in the race to control the asthma epidemic.     

抗艾滋病药物研究的新靶点

目前,临床使用的抗艾滋病药物主要是逆转录酶抑制剂和蛋白酶抑制剂。由于这些药物的毒性和耐药性等问题日益严重,寻找抗艾滋病药物的新靶点已经成为当务之急。在细胞水平上对HIV病毒自身生活周期的研究发现了一些新的药物靶点,其中包括病毒自身生活周期所需的蛋白,宿主细胞内源性抗病毒因子及其他抗HIV-1感染的潜在靶标。本文对近年来研究中出现的新的抗艾滋病药物靶点作一综述。     

Carboxylesterases--detoxifying enzymes and targets for drug therapy

Carboxylesterases (CE) are ubiquitous enzymes responsible for the detoxification of xenobiotics. Many therapeutically useful drugs are metabolized by these proteins which impacts upon the efficiency of drug treatment. In some instances, CEs convert inactive prodrugs to active metabolites, a process that is essential for biological activity. Such compounds include the anticancer agents CPT-11 (3) and capecitabine (4), the antibiotics Ceftin (9) and Vantin, as well as the illicit street drug heroin (6). However, more commonly, CEs hydrolyze many esterified drugs to inactive products that are then excreted. Agents such as flestolol (11), meperidine (5), lidocaine (8) and cocaine (7), are all hydrolyzed and inactivated by these enzymes. Therefore the efficacy of esterified drugs will be dependent upon the distribution and catalytic activity of different CEs. In this review, we examine the structural aspects of CEs and their roles in drug detoxification and propose that modulation of CE activity may allow for improvements in, and potentiation of, drug efficacy.     

Mitochondrial off targets of drug therapy

The bioenergetic features of mitochondria have long been exploited in the design of pharmacological agents suited to accomplish a desired physiological effect; uncoupling of oxidative phosphorylation to induce weight loss, for example. However, more recent experience demonstrates mitochondria to be unintended off targets of other drug therapies and responsible, at least in part, for the dose-limiting adverse events associated with a large array of pharmaceuticals. Review of the fundamentals of mitochondrial molecular biology and bioenergetics reveals a multiplicity of off targets that can be invoked to explain drug-induced mitochondrial failure. It is this redundancy of mitochondrial off targets that complicates identification of discrete mechanisms of toxicity and confounds QSAR-based design of new small molecules devoid of this potential for mitochondrial toxicity. The present review article briefly reviews the molecular biology and biophysics of mitochondrial bioenergetics, which then serves as a platform for identifying the various potential off targets for drug-induced mitochondrial toxicity.     

Emerging targets for antimalarial drugs

The absence of an effective vaccine against malaria and the ability of the parasite to develop resistance to known antimalarial drugs makes it mandatory to unravel newer drug targets with a view to developing newer pharmacophores. While conventional targets such as the purine, pyrimidine and folate pathways are still being investigated in the light of newer knowledge, a new opportunity has emerged from an understanding of certain unique features of the parasite biology. These include the food vacuole, haemoglobin catabolism, haeme biosynthesis, apicoplasts and their metabolism as well as macromolecular transactions, import of host proteins, parasite induced alterations in the red cell surface and transport phenomena. This review seeks to emphasise the new and emerging targets, while giving a brief account of the targets that have already been exploited.