Natural surfactants or biosurfactants are amphiphilic biological compounds, usually extracellular, produced by variety of microorganisms from various substances including waste materials. There is an increasing interest on this topic because of their unique properties such as low toxicity, functionality under extreme conditions, based on renewable substances and biologically degradable nature. The diversity of these molecules supports them for their potential application in the field of petroleum, medicine, agriculture, food, cosmetics etc. They are also effective in curtailing green-house effect by reducing the emission of CO 2 . They can be termed as 'green' because of their low toxicity, biodegradability and relative stability under a wide range of physicochemical environments.
Pannexin1 (Panx1) channels are large high conductance channels found in all vertebrates that can be activated under several physiological and pathological conditions. Our published data indicates that HIV infection results in the extended opening of Panx1 channels (5 min – 60 min), allowing for the secretion of ATP through the channel pore with subsequent activation of purinergic receptors, which facilitates HIV entry and replication. In the current report we demonstrate that chemokines, which bind CCR5 and CXCR4, especially SDF-1α/CXCL12, result in a transient opening (peak at 5 min) of Panx1 channels found on CD4+ T lymphocytes which induces ATP secretion, focal adhesion kinase phosphorylation, cell polarization and subsequent migration. Increased migration of immune cells is key for the pathogenesis of several inflammatory diseases including multiple sclerosis (MS). Here we show that genetic deletion of Panx1 reduces the number of the CD4+ T lymphocytes migrating into the spinal cord of mice subjected to experimental autoimmune encephalomyelitis, an animal model of MS. Our results indicate that opening of Panx1 channels in response to chemokines is required for CD4+ T lymphocyte migration, and we propose that targeting Panx1 channels could provide new potential therapeutic approaches to decrease the devastating effects of MS and other inflammatory diseases.
Cell-to-cell communication is essential for the development and proper function of multicellular systems. We and others demonstrated that tunneling nanotubes (TNT) proliferate in several pathological conditions such as HIV, cancer, and neurodegenerative diseases. However, the nature, function, and contribution of TNT to cancer pathogenesis are poorly understood. Our analyses demonstrate that TNT structures are induced between glioblastoma (GBM) cells and surrounding non-tumor astrocytes to transfer tumor-derived mitochondria. The mitochondrial transfer mediated by TNT resulted in the adaptation of non-tumor astrocytes to tumor-like metabolism and hypoxia conditions. In conclusion, TNT are an efficient cell-to-cell communication system used by cancer cells to adapt the microenvironment to the invasive nature of the tumor.
Human immunodeficiency virus type 1 (HIV-1) and viral proteins affect neuronal survival and neuron-glial cell interactions, which culminate in neurological disorders. HIV-1 infects regions of neurogenesis in human adult and pediatric brain. However, little is known about the effect of HIV-1 or viral proteins on the properties of human neural precursor cells (hNPCs), particularly neurogenesis, hence a detailed investigation on these lines is warranted. Human neural precursor cells were cultured in presence and absence of HIV-1B transactivating protein Tat to investigate if HIV-1 viral protein alters the properties of human neural precursor cells. Cellular and molecular approaches were adopted to study the effect of HIV-1B transactivating protein Tat on proliferation and differentiation potential of human fetal brain-derived NPCs. Cell proliferation assays such as BrdU and Ki67 staining and pathway-specific cDNA and protein arrays were used in the study. Data reveal that HIV-1B Tat protein severely affects proliferation of hNPCs, as evident by lower incorporation of BrdU and Ki67 staining as well as neurosphere assay. HIV-1 Tat substantially attenuated neurogenesis, as evident by the smaller numbers of Tuj-1- and doublecortin-positive cells differentiated from hNPCs, without affecting their viability. These data suggest that HIV-1 Tat alters the properties of human neural precursor cells via attenuation of the cell cycle regulatory unit cyclin D1 and the mitogen-activated protein kinase (MAPK) pathway, particularly extracellular signal-related kinase 1/2 (ERK1/2). The study provides new insights into cellular and molecular mechanisms that may modulate human neural precursor cell properties in HIV/AIDS (acquired immunodeficiency syndrome) individuals. Validation with autopsy brain samples is necessary to further substantiate these important observations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.