Current Drug Targets - Volume 15, Issue 8, 2014

Accumulating evidence indicates that the aberrantly altered process of autophagy is definitely involved in carcinogenesis. Nonetheless, Toll-like receptors (TLRs) sensing cell-derived pattern/danger-associated molecules also have the capacity to promote tumor development and immune escape. TLRs are usually expressed in immunocompetent cells, though several types of cancer cells have also been reported to display these innate immune receptors. On the other hand, however, both TLR- and autophagy-related signals may exert tumor suppressor mechanisms mainly in a cell-specific and context-dependent manner. The role of autophagy has been radically expanded, and now this machinery is considered as a fundamental eukaryotic cellular homeostatic process and integral component of the immune system influencing infection, inflammation and immunity. Recent studies have documented that TLRs and autophagy are interrelated in response to danger signals, furthermore there is a controling cross-talk among them to avoid deficient or excessive immunological effects. Although the potential interaction of autophagy and TLRs in cancer cells has not yet been clarified, it seems to be a critical aspect of cancer development and progression. Upon translation of basic knowledge into practice it is reasonable to speculate that modulation of the TLR-autophagy regulatory loop might be relevant for cancer treatment by providing further possible therapeutic targets.

To screen the active antimalarial novel artemisinin derivatives, a QSAR modeling approach was used. QSAR model showed high correlation (r2= 0.83 and rCV2= 0.81) and indicated that Connectivity Index (order 1, standard), Connectivity Index (order 2, standard), Dipole Moment (debye), Dipole Vector X (debye) and LUMO Energy (eV) well correlate with activity. High binding likeness on antimalarial target plasmepsin was detected through molecular docking. Active artemisinin derivatives showed significant activity and indicated compliance with standard parameters of oral bioavailability and ADMET. The active artemisinin derivatives namely, β-Artecyclopropylmether HMCP (A3), β– Artepipernoylether (PIP-1) (A4) and 9-(β-Dihydroartemisinoxy)methyl anthracene (A5) were semi-synthesized and characterized based on its 1H and 13C NMR spectroscopic data and later activity tested in vivo on mice infected with multidrug resistant strain of P. yoelii nigeriensis. Predicted results were successfully validated by in vivo experiments.

Human beings and gut microbiota are in a symbiotic relationship, and the hypothesis of a “super organism” composed of the human organism and microbes has been recently proposed. The gut microbiota fulfills important metabolic and immunological tasks, and the impairment of its composition might alter homeostasis and lead to the development of microbiota-related diseases. The most common illnesses associated with alterations of the gut microbiota include inflammatory bowel disease, gastroenteric infections, irritable bowel syndrome and other gastrointestinal functional diseases, colorectal cancer, metabolic syndrome and obesity, liver diseases, allergic diseases, and neurological diseases such as autism. In theory, every disease associated with the impairment of intestinal microflora might benefit from the therapeutic modulation of the gut microbiota. A number of attempts to manipulate the microbiota have not produced identical results for every disease. Although antibiotics and probiotics have been available for a long time, the so-called fecal microbiota transplantation, which is a very old remedy, was only recently re-evaluated as a promising therapeutic approach for microbiota impairment. A comprehensive understanding of the gut microbiota composition, in states of both health and various diseases, is needed for the development of future approaches for microbiota modulation and for developing targeted therapies. In this review, we describe the role of the microbiota in several diseases and the related treatment options that are currently available.

Ischemic stroke is a leading cause of mortality and morbidity worldwide. Numerous therapeutic studies, including stem cell therapy, have been explored in order to find the possible approach treating cerebral ischemia effectively. However, massive grafted-cell death and low survival rate made us pessimistic about the widespread application of stem cell therapy. The approach of preconditioning stem cells became an attractive option due to its high cell viability after transplantation. In this review, we focused on preconditioning stem cells via cytokines, chemical drugs and other factors including interleukin 6 (IL-6), lipopolysaccharide (LPS), minocycline, melatonin and hypoxia to increase grafted stem cell survival, proliferation, migration to ischemic peri-focal area and ultimately improve neurobehavioral outcomes. We explored the underlying therapeutic efficacy of preconditioning stem cells as well as possible mechanisms and potential risks. Finally, we discussed the prospects of the application of cell-based therapy in clinical patients with ischemic stroke.

Many natural products contain sugar residues, which are essential components for great medicinal importance. The sugar moieties can improve water-solubility of natural products and decrease their toxicity. At the same time, the glycosidic residues are crucial for the activities of natural products. Much effort has been expended over the past decades in developing novel and efficient methodologies to synthesize the glycosylated natural products. This review highlights recent developments in the synthesis of glycosylated natural products. The structure-activity relationships of some of these glycosylated natural products, together with the structure characteristics of their interaction with the biological targets, are also involved.

Malignant tumors of salivary glands are rare lesions, often with poor prognosis. At present, surgery represents the only therapeutic choice, whereas chemotherapy is employed as palliative treatment in advanced disease. Over the years several molecular alterations associated with the pathogenesis and progression of the salivary glands tumors have been well-characterized. Particularly, the mutational status and/or aberrant expression of certain markers, such as EGFR, HER2, cKIT, BRAF and AR, also identified in some tumor histotypes of the salivary glands, currently represent molecular targets for new and efficacious drugs routinely employed in the treatment of other neoplasias, such as breast, lungs, GIST and melanoma. The expression analysis of these biomarkers associated with histomorphological data, could then provide the oncologist the opportunity to create a proper stratification of patients for customized therapies. This review represents an overview of the lesions of the salivary glands best characterized in terms of molecular aspects, focusing the attention on those markers and molecular alterations which can be important in the diagnosis as well as in the therapeutic stratification of these tumors.

The traditional view of mitochondria as cell powerhouses is a matter of common knowledge, but the overall view of these extraordinary organelles has been revolutionized in the last years. In fact, a large number of important and diverse processes take place at the mitochondrial level, which clearly surpass the energy production scope, intruding the critical fragile balance between cell life and death. The entangled biochemistry of mitochondrial membranes has been found to be dependent on specific lipid requirements, with cardiolipin holding a great part of the raised functional interest. Mitochondria contain a complex membrane system, based on a variety of lipids and exquisite asymmetries. Mitochondria lipid membrane composition depends on a tight interplay with the endoplasmic reticulum, from which some of the lipids present in the mitochondrial membranes have to be imported, at least in the form of precursors. Here, we review some external interventions resulting in alterations of mitochondrial lipid content, namely dietary interventions and genetic manipulation. Such manipulations of mitochondrial membrane lipid composition should result in physiological impact, given the importance of lipid-protein interactions within the mitochondrial membrane boundaries. We provide arguments for future experiments using the most modern chemical and biophysical approaches as well as computer simulation studies applied to appropriate biological membrane model systems, in order to identify the effects exerted by diet-induced lipid changes on membrane physical properties.

Although an increased oxidative stress has been associated with several pathologies, predictive value of circulating oxidative stress biomarkers remains poorly understood. It has been demonstrated that several pathologies underestimated in women, including cardiovascular diseases, develop differently by gender. In this study, conducted on 195 healthy volunteers, we assessed the putative gender difference in prooxidant and antioxidant status. Our results were successful in demonstrating a significant difference in oxidative stress between sexes, whereas no difference was found in the plasma antioxidant barrier efficiency. To assess whether this difference was due to hormonal status (i.e. estrogen levels), female samples were divided into pre-menopausal and post-menopausal groups. No significant difference emerged for both biomarkers. Despite the well-known antioxidant estrogen role, women in this study presented a higher oxidative status than males. This suggests that there is a difference in the production and metabolic deactivation of reactive oxygen metabolite.