Cell-Penetrating Peptides: A Challenge for Drug Delivery

Cell-penetrating peptide (CPP) is a term that describes relatively short amphipathic and cationic peptides (7–30 amino acid residues) with rapid translocation across the cell membrane. They can be used to deliver molecular bioactive cargoes due to their efficacy in cellular internalization and also to their low cytotoxicity. In this review we provide an overview of the current approaches and describe the potential of CPP-based drug delivery systems and indicate their powerful promise for clinical efficacy

Rapid multi-residue method for the determination of pesticide residues in human serum

Exposure to pesticides can represent a potential risk to humans. Agricultural workers are at risk of chronic toxicity. Hence, the evaluation of pesticide residues in their blood gives an indication about the extent of exposure and help in assessing adverse health effects. The aim of our study was to develop analytical method for the simultaneous determination of some residues of pesticides using gas chromatography-mass spectrometry (GC-MS). This method involves a liquid-liquid extraction procedure. Pesticide residues were separated and detected using GC-MS, and acquisition was performed in the sellected ion monitoring (SIM) mode. For most of the pesticides, average recoveries ranged between 65 and 101% at three different fortification levels. The linearity of the method was satisfactory in the range of 5 to 50 ng/ml, with a correlation coefficient between 0.998 and 0.999, depending on the analyte. The estimated limit of detection and limit of quantification ranged from 2 to 5 ng/ml and from 5 to 10 ng/ml, respectively. The method precision and accuracy were found to be satisfactory at three concentration levels. The variation coefficients of intra-day and inter-day precision ranged from 0.4 to 14% and from 2.5 to 15%, respectively for most studied pesticides.Keywords: Analytical methods, human serum, GC-MS, pesticide residues, validatio

Localization and role of RAP55/LSM14 in HeLa cells: a new finding on the mitotic spindle assembly

The MAP family includes large proteins like MAP-1A, MAP-1B, MAP-1C, MAP-2, and MAP-4 and smaller components like tau and MAP-2C. This article focuses on the relevant aspects of RAP55/LSM14 position with emphasis on its role in mitotic spindle formation and stability. In this context, the localization of RNA associated Protein 55kDa (RAP55/LSM14) during mitosis was identified as a Mitotic Spindle Protein (MSP). We found a new location obtained by expressing GFP-tagged proteins in HeLa Cells during mitosis that has never been previously reported. We demonstrated also, for the first time, that the depletion of RAP55/LSM14 destabilizes spindle assembly, stops cells in mitosis and induces many other cell cytoskeletal disorders. Finally, by using an "in vitro" assay investigation, we found that RAP55/LSM14 binds directly the tubulin and that is implicated in the process of the mitotic spindle stabilization, which is a novel discovery in this field of research

Polymorphism on Chromosome 9p21.3 Is Associated with Severity and Early-Onset CAD in Type 2 Diabetic Tunisian Population

Multiple association studies found that the human 9p21.3 chromosome locus is a risk factor for atherosclerosis. The purpose of this study was to investigate the association of the severity and early-onset of coronary artery disease with variant rs1333049 on chromosome 9p21.3 polymorphism and the impact of this variant on cardiovascular risk factors in type 2 diabetic patients. The study population consisted of a control CAD group (101 patients) and 273 consecutive type 2 diabetic patients. Severity and extent of coronary atherosclerosis were scored numerically using the Gensini scoring system. The diabetic population was divided into three groups according to Gensini score: Group 1: no stenosis; Group 2: moderate CAD; Group 3, severe CAD. The homozygous CC genotype of rs1333049 was significantly associated with CAD in Group 2 (OR: 1.36; p=0.02) and Group 3 (OR: 5.77, p<0.001) compared to Group 1 (OR: 0.18; p=0.2) and control group (OR: 0.22; p=0.21). Among diabetic patients with early-onset CAD, CC genotype carriers had significantly higher Gensini scores than non-CC genotype carriers (49±21.3 versus 14.87±25.22; p<0.001). The homozygous CC genotype of rs1333049 confers a magnified risk of early-onset and severe CAD in type 2 diabetic Tunisian population

Cytotoxicity, intracellular distribution and uptake of doxorubicin and doxorubicin coupled to cell-penetrating peptides in different cell lines: a comparative study.

International audienceOne of the major obstacles which are opposed to the success of anticancer treatment is the cell resistance that generally develops after administration of commonly used drugs. In this study, we try to overcome the tumour cell resistance of doxorubicin (Dox) by developing a cell-penetrating peptide (CPP)-anticancer drug conjugate in aim to enhance its intracellular delivery and that its therapeutic effects. For this purpose, two cell-penetrating peptides, penetratin (pene) and tat, derived from the HIV-1 TAT protein, were chemically conjugated to Dox. The cytotoxicity, intracellular distribution and uptake were accessed in CHO cells (Chinese Hamster Ovarian carcinoma cells), HUVEC (Human Umbilical Vein Endothelial Cells), differentiated NG108.15 neuronal cell and breast cancer cells MCF7drug-sensitive or MDA-MB 231 drug-resistant cell lines. The conjugates showed different cell killing activity and intracellular distribution pattern by comparison to Dox as assessed respectively by MTT-based colorimetric cellular cytotoxicity assay, confocal fluorescence microscopy and FACS analysis. After treatment with 3 microM with Dox-CPPs for 2h, pene increase the Dox cytotoxicity by 7.19-fold in CHO cells, by 11.53-fold in HUVEC cells and by 4.87-fold in MDA-MB 231 cells. However, cytotoxicity was decreased in NG108.15 cells and MCF7. Our CPPs-Dox conjugate proves the validity of CPPs for the cytoplasmic delivery of therapeutically useful molecules and also a valuable strategy to overcome drug resistance

Efficient induction of apoptosis by doxorubicin coupled to cell-penetrating peptides compared to unconjugated doxorubicin in the human breast cancer cell line MDA-MB 231.

International audienceDoxorubicin (Dox) is a commonly used drug to treat various types of cancers. Previously, we demonstrated that coupling Dox to cell-penetrating peptides (CPPs) represent a valuable strategy to overcome drug resistance in MDA-MB 231 breast cancer cells. In the present study, we evaluated the properties of these Dox conjugates (Dox-CPPs) in terms of apoptosis induction. Dox-CPPs were found to induce apoptotic death in MDA-MB 231 cells at a lower dose than that needed for unconjugated Dox. Cell death induction was associated with Bax oligomerisation, release of cytochrome c, caspase activation, chromatin condensation and internucleosomal degradation. However, whereas Bcl-2 overexpression was very potent in inhibiting apoptosis triggered by Dox, this anti-apoptotic protein was largely inefficient in preventing Dox-CPPs-induced apoptosis. These observations suggest that mitochondrial disruption is the main event in Dox-induced apoptotic signaling but that Dox-CPPs are probably able to trigger additional apoptotic pathways independent of mitochondrial events. Thus, the higher efficacy of Dox conjugated to CCPs in apoptosis induction might not be due exclusively to increased drug accumulation but also to the activation of multiple apoptotic pathways

In vitro antibacterial activity of the Hertia cheirifolia L. essential oils

Objective: To investigate the antibacterial activity of essential oils from Hertia cheirifolia L. flowers, vegetative part (leaves + stems) and roots against a panel of bacterial strains. Methods: The essential oils from Hertia cheirifolia L. flowers, vegetative part (leaves + stems) and roots were analyzed by gas chromatography and gas chromatography–mass spectrometry. The antibacterial activity of essential oils was evaluated in vitro by the broth dilution method. Results: The results showed that the essential oil of flowers exhibited a strong antibacterial activity against Staphylococcus aureus with minimal inhibitory concentration of 0.078 mg/mL. Conclusions: The essential oils of Hertia cheirifolia can be a good source of antibacterial compounds. They can be used for pharmaceutical treatments

The combination of Bleomycin with TRAIL agonists or PKC inhibitors sensitizes solid tumor cells to BLM-mediated apoptosis: new strategies to overcome chemotherapy resistance of tumors

IF 1.436International audienceIn this study we evaluated the effects of low dose of bleomycin in an associative treatment strategy in solid tumor cells. For this purpose, Human and murine colon cancer (SW480, HCT8, and CT26), and murine melanoma (B16-F10) cells were treated with different agents including protein kinase C, and c-jun NH2-terminal kinase inhibitors, and tumor necrosis factor-related apoptosis-inducing ligand. Apoptosis was identified by morphological criteria. Reactive oxygen species are evaluated by flow cytometry. Our data showed that bleomycin (100 µM) induced apoptosis in all the four cell lines tested with a level ranging from 30 to 60%. However, at lower dose (25 µM), bleomycin was less efficient to trigger apoptosis. In contrast, when bleomycin (25 µM) was combined with the protein kinase C inhibitor chelerythrine, or tumor necrosis factor-related apoptosis-inducing ligand, it elicited more apoptotic cell death ranging from 40 to 75%, depending on the cell type, whereas when it was associated with the c-jun NH2-terminal kinase inhibitor SP600125, bleomycin displayed different cell death responses. If bleomycin and SP600125 enhanced apoptosis in two colon cancer cells, HCT-8, and CT26, they reduced to 50% apoptosis in the melanoma B16-F10 cells, and were not synergistic in the human colon cancer cells, SW480. This synergism seemed to rely partially to reactive oxygen species, because N-acetyl cysteine inhibited apoptosis in some cells and with some agents. These findings indicate that tumor necrosis factor-related apoptosis-inducing ligand, and protein kinase C inhibition can represent candidates for improved cancer chemotherapy