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Fab fragments of amyotrophic lateral sclerosis (ALS) immunoglobin G (IgG) influences the calcium channels of mammalian skeletal muscle that are sensitive to dihydropyridine (DHP). IgG fab fragments are synthesized from the sera or plasma of ALS patients and introduced into isolated rat skeletal muscle fibers in vitro. Peak voltage gated, calcium currents are decreased, but there is inconsiderable change in the peak calcium current kinetics. There is a change in the cell function due to direct interaction between antibodies from sera of ALS patients and voltage gated calcium channels.

Malignant mesothelioma ( MMe) is a highly aggressive, lethal tumour requiring the development of more effective therapies. The green tea polyphenol epigallocathechin-3-gallate ( EGCG) inhibits the growth of many types of cancer cells. We found that EGCG is selectively cytotoxic to MMe cells with respect to normal mesothelial cells. MMe cell viability was inhibited by predominant induction of apoptosis at lower doses and necrosis at higher doses. EGCG elicited H2O2 release in cell cultures, and exogenous catalase ( CAT) abrogated EGCG-induced cytotoxicity, apoptosis and necrosis. Confocal imaging of fluo 3-loaded, EGCG-exposed MMe cells showed significant [Ca2+]i rise, prevented by CAT, dithiothreitol or the T-type Ca2+ channel blockers mibefradil and NiCl2. Cell loading with dihydrorhodamine 123 revealed EGCG-induced ROS production, prevented by CAT, mibefradil or the Ca2+ chelator BAPTA- AM. Direct exposure of cells to H2O2 produced similar effects on Ca2+ and ROS, and these effects were prevented by the same inhibitors. Sensitivity of REN cells to EGCG was correlated with higher expression of Cav3.2 T-type Ca2+ channels in these cells, compared to normal mesothelium. Also, Cav3.2 si RNA on MMe cells reduced in vitro EGCG cytotoxicity and abated apoptosis and necrosis. Intriguingly, Cav3.2 expression was observed in malignant pleural mesothelioma biopsies from patients, but not in normal pleura. In conclusion, data showed the expression of T-type Ca2+ channels in MMe tissue and their role in EGCG selective cytotoxicity to MMe cells, suggesting the possible use of these channels as a novel MMe pharmacological target. [ABSTRACT FROM AUTHOR]

Abstract Cultured spinal cord motoneurons from day 15 rat embryos (E15) represent a useful model to study Ca2+ channel diversities and their regulation by neurotrophins. Besides the previously identified L-, N- and P-type channels, E15 rat motoneurons also express high densities of R-type channels. We have previously shown that the P-type channel is nearly absent in 60% of these cells, while the R-type contributes to ≈ 35% of the total current. Here, we show that chronic preincubation of cultured rat motoneurons with high concentrations (20–100 ng/mL) of brain-derived neurotrophic factor (BDNF) caused a selective up-regulation of the P- and R-type current density available after blocking N- and L-type channels, with no changes to cell membrane capacitance. N- and L-type channels were either not affected or slightly down-modulated by the neurotrophin. The onset of BDNF up-regulation of P/R-type currents had a half-time of 12 h and reached maximal values of ≈ 80%. High concentrations of nerve growth factor (NGF; 50–100 ng/mL) had no effect on P/R currents, while BDNF action was prevented by the kinase inhibitor K252a and by the protein synthesis inhibitor anisomycin. These results suggest that chronic applications of BDNF selectively up-regulates the Ca2+ channel types which are most likely to be involved in the control of neurotransmitter release in mammalian neuromuscular junctions. The signal transduction mechanism is probably mediated by TrkB receptors and involves the synthesis of newly functionally active P- and R-type channels. Our data furnish a rationale for a number of recent observations in other laboratories, in which prolonged applications of neurotrophins were shown to potentiate the presynaptic response in developing synapses. [ABSTRACT FROM AUTHOR]

Breast reconstruction has gained from lipofilling the possibility to recover the aesthetic outcome of anatomical profile in a more natural appearance. However, until today, the long-term graft survival remains unpredictable, and sometimes it does not guarantee a well-adequate aesthetic result. In the present work, the morphological changes, occurring in fat mass used for refilling, harvested by the Coleman's procedure or through the washing/fragmenting procedure were analysed. Adipocyte size; immunohistochemistry against CD8, CD31, CD68 and M2-type macrophages and catalase enzyme, were analysed in vitro on fat mass cultured for 4 weeks. Our observation reveals an increase of connective tissue around the mass and a high number of immune cells occurrence in fat mass harvested by the Coleman's procedure. Instead, the washing/fragmented procedure would reduce the number of immune cells within the fat mass, increase the size of adipocytes, and cause a wider presence of active vessels profile and greater catalase expression. We hypothesize that the fat mass processed by the Coleman's procedure would remain more reactive due to a higher number of immune and macrophages cells, prone to develop cystic formation, leading to a suboptimal integration in the recipient site. On the other hand, the conditions more prone to realize an optimal integration would occur in the fat mass processed by the washing/fragmenting procedure: a reduced number of immune cells, low amount of connective tissue, presence of larger adipocytes. Follow-up monitoring did support our conclusion, as we observed a reduction of re-intervention for refilling procedure in patients treated with the washing/fragmenting procedure.

Malignant mesothelioma (MMe) is a highly aggressive, lethal tumour requiring the development of more effective therapies. The green tea polyphenol epigallocathechin-3-gallate (EGCG) inhibits the growth of many types of cancer cells. We found that EGCG is selectively cytotoxic to MMe cells with respect to normal mesothelial cells. MMe cell viability was inhibited by predominant induction of apoptosis at lower doses and necrosis at higher doses. EGCG elicited H(2) O(2) release in cell cultures, and exogenous catalase (CAT) abrogated EGCG-induced cytotoxicity, apoptosis and necrosis. Confocal imaging of fluo 3-loaded, EGCG-exposed MMe cells showed significant [Ca(2+) ](i) rise, prevented by CAT, dithiothreitol or the T-type Ca(2+) channel blockers mibefradil and NiCl(2) . Cell loading with dihydrorhodamine 123 revealed EGCG-induced ROS production, prevented by CAT, mibefradil or the Ca(2+) chelator BAPTA-AM. Direct exposure of cells to H(2) O(2) produced similar effects on Ca(2+) and ROS, and these effects were prevented by the same inhibitors. Sensitivity of REN cells to EGCG was correlated with higher expression of Ca(v) 3.2 T-type Ca(2+) channels in these cells, compared to normal mesothelium. Also, Ca(v) 3.2 siRNA on MMe cells reduced in vitro EGCG cytotoxicity and abated apoptosis and necrosis. Intriguingly, Ca(v) 3.2 expression was observed in malignant pleural mesothelioma biopsies from patients, but not in normal pleura. In conclusion, data showed the expression of T-type Ca(2+) channels in MMe tissue and their role in EGCG selective cytotoxicity to MMe cells, suggesting the possible use of these channels as a novel MMe pharmacological target., (© 2012 The Authors Journal of Cellular and Molecular Medicine © 2012 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.)