Purinergic Signaling in Neuroinflammation

ATP is stored in millimolar concentrations within the intracellular medium but may be released to extracellular sites either through the damaged plasma membrane or by means of various transporters [...]

Antifungal Properties of Two Volatile Organic Compounds on Barley Pathogens and Introduction to Their Mechanism of Action

This study evaluated the antifungal effects of various volatile organic compounds (VOCs) against two common pathogens: Fusarium culmorum and Cochliobolus sativus. Among the various VOCs, methyl propanoate (MP) and methyl prop-2-enoate (MA) exhibited remarkable antifungal effects under different experimental conditions (direct or indirect contact) and at different concentrations (500–1000 μM). In addition, the type of antifungal effect (fungistatic or fungicidal) appeared to be strongly correlated with the VOC concentrations. Additional tests revealed that both molecules increased membrane permeability of pathogenic spores, which resulted in a decreased efflux of K+ ions into the intracellular medium.

Fate of cisplatin and its main hydrolysed forms in the presence of thiolates: a comprehensive computational and experimental study

Thiolations and bidentations drive the chemical fate of cisplatin compounds in intracellular medium.

Effect of Potassium Ions on Protoplast Generation during Yeast Induction from Mucor circinelloides Tieghem

Mucor circinelloides aerobically exhibits coenocytic thallic growth habit with straight and circinate sporangiophores which culminate in globose or pyriform columellae enclosed within sporangial walls. It undergoes dimorphic switch with its conversion to multipolar budding yeast-like cells or thallic conidia. This paper confirms the induction of plurality of reproductive structures of the pleomorphic microorganism in minimal medium. Furthermore, construction of pH differentials at inflection points in the biphasic profiles during sporangiospore-yeast transformation indicated the intensity of H+ release from intracellular medium of the growing microorganism in a study conducted with K+ levels (0.0, 0.5, 0.7, 0.9, 1.0,1.10 g/L)-mediated broths. Optimum proton release was at 0.00 and 1.0 g/L K+-supplemented broths, but specific growth rate was least in the latter. It also coincided with a preponderance of neoplastic units, protoplasts, and terminal budding yeast cells. On either side of this K+ level, variation in morphologies, including neoplasts, protoplasts, septate hyphae, thallic, holothallic, and holoblastic conidia, was greater, although olive-green septate hyphae with vesicular conidiogenous apparatus occurred at all K+ levels tested. This study suggested that following the establishment of transmembrane pH gradient across protoplast membrane, operation of Mitchellian proton pump was further promoted, thus leading to active transport mechanism, a prelude to yeast morphology induction.

Golgi-Disturbing Agents Lead to the Elimination of Intracellular Toxoplasma gondii

The Golgi apparatus is responsible for the genesis of secretory organelles of Toxoplasma gondii and lipid traffic to the vacuole. This study used anti-Golgi agents to demonstrate the importance of Golgi in Toxoplasma development. Monensin, Brefeldin A, Retinoic Acid and Okadaic Acid reduced the infection, leading to parasite elimination. Mon, BFA and RA affected secretory organelles and the Golgi Complex of the parasites, with faster parasite elimination in the presence of Monensin; in addition, the vesicular transit of host cell C6-NBD-ceramide metabolites was interrupted, but the GC of host cells was preserved. Our results suggest that several targets in the secretory pathway are affected in the intracellular Toxoplasma rather than in the host cells, resulting in interruption of parasite development and its elimination from the intracellular medium.

Maximal Ca2+ i stimulation of cardiac Na+/Ca2+ exchange requires simultaneous alkalinization and binding of PtdIns-4,5-P2 to the exchanger

Using bovine heart sarcolemma vesicles we studied the effects of protons and phosphatidylinositol-4,5-bisphosphate (PtdIns-4,5-P2) on the affinity of the mammalian Na+/Ca2+ exchanger (NCX1) for intracellular Ca2+. By following the effects of extravesicular ligands in inside-out vesicles, their interactions with sites of NCX1 facing the intracellular medium were investigated. Two Na+-gradient-dependent fluxes were studied: Ca2+ uptake and Ca2+ release. PtdIns-4,5-P2 binding to NCX1 was investigated in parallel. Without MgATP (no ‘de novo’ synthesis of PtdIns-4,5-P2), alkalinization increased the affinity for Ca2+ and the PtdIns-4,5-P2 bound to NCX1. Vesicles depleted of phosphoinositides were insensitive to alkalinization, but became responsive following addition of exogenous PtdIns-4,5-P2 or PtdIns plus MgATP. Acidification reduced the affinity for Ca2+ ev; this was only partially reversed by MgATP, despite the increase in bound PtdIns-4,5-P2 to levels observed with alkalinization. Inhibition of Ca2+ uptake by increasing extravesicular [Na+] indicates that it is related to H+ i and Na+ i synergistic inhibition of the Ca2+ i regulatory site. Therefore, the affinity of the NCX1 Ca2+ i regulatory site for Ca2+ was maximal when both intracellular alkalinization and an increase in PtdIns-4,5-P2 bound to NCX1 (not just of the total membrane PtdIns-4,5-P2) occurred simultaneously. In addition, protons influenced the distribution, or the exposure, of PtdIns-4,5-P2 molecules in the surroundings and/or on the exchanger protein.