Glucose stimulation of insulin release involves closure of ATPsensitive K+ channels (K+-ATP channels), depolarization, and Ca" influx in B cells. However, by using diazoxide to open K+-ATP channels, and 30 mM K to depolarize the membrane, we could demonstrate that another mechanism exists, by which glucose can control insulin release independently from changes in K+-ATP channel activity and in membrane potential (Gembal et al. 1992. J. Clin. Invest. 89:1288-1295). A similar approach was followed here to investigate, with mouse islets, the nature of this newly identified mechanism. The membrane potential-independent increase in insulin release produced by glucose required metabolism of the sugar and was mimicked by other metabolized secretagogues. It also required elevated levels of cytoplasmic CO', but was not due to further changes in CO'. It could not be ascribed to acceleration of phosphoinositide metabolism, or to activation of protein kinases A or C. Thus, glucose did not increase inositol phosphate levels and hardly affected cAMP levels. Moreover, increasing inositol phosphates by vasopressin or cAMP by forskolin, and activating protein kinase C by phorbol esters did not mimic the action of glucose on release, and down-regulation of protein kinase C did not prevent these effects. On the other hand, it correlated with an increase in the ATP/ADP ratio in islet cells. We suggest that the membrane potential-independent control of insulin release exerted by glucose involves changes in the energy state of B cells. (J. Clin. Invest. 1993.91:871-880.)
Despite worldwide promising clinical outcome of CD19 CART therapy, relapse after this therapy is associated with poor prognosis and has become an urgent problem to be solved. We conducted a CD22 CAR T-cell therapy in 34 relapsed or refractory (r/r) BALL pediatric and adult patients who failed from previous CD19 CAR T-cell therapy. Complete remission (CR) or CR with incomplete count recovery (CRi) was achieved in 24 of 30 patients (80%) that could be evaluated on day 30 after infusion, which accounted for 70.5% of all 34 enrolled patients. Most patients only experienced mild cytokine-release syndrome and neurotoxicity. Seven CR patients received no further treatment, and 3 of them remained in remission at 6, 6.6, and 14 months after infusion. Eleven CR patients were promptly bridged to transplantation, and 8 of them remained in remission at 4.6 to 13.3 months after transplantation, resulted in 1-year leukemia-free survival rate of 71.6% (95% CI, 44.2-99.0). CD22 antigen loss or mutation was not observed to be associated with relapsed patients. Our study demonstrated that our CD22 CAR T-cells was highly effective in inducing remission in r/r BALL patients, and also provided a precious window for subsequent transplantation to achieve durable remission.
A green route is developed to prepare hierarchical porous carbon sheets (HPCS) from biomass directly under air atmosphere without inert gas protection. The as-prepared HPCS with ultra-thin structure, rich O doping sites and large SSA demonstrate excellent specific capacitance and stability when used in supercapacitor.
Synaptotagmins (Syt) play important roles in Ca2؉ -induced neuroexocytosis. Insulin secretion of the pancreatic -cell is dependent on an increase in intracellular Ca 2؉ ; however, Syt involvement in insulin exocytosis is poorly understood. Reverse transcriptase-polymerase chain reaction studies showed the presence of Syt isoforms III, IV, V, and VII in rat pancreatic islets, whereas Syt isoforms I, II, III, IV, V, VII, and VIII were present in insulin-secreting TC3 cell. Syt III and VII proteins were identified in rat islets and TC3 and RINm5F -cells by immunoblotting. Confocal microscopy showed that Syt III and VII co-localized with insulin-containing secretory granules. Two-fold overexpression of Syt III in RINm5F -cell (Syt III cell) was achieved by stable transfection, which conferred greater Ca 2؉ sensitivity for exocytosis, and resulted in increased insulin secretion. Glyceraldehyde ؉ carbachol-induced insulin secretion in Syt III cells was 2.5-fold higher than control empty vector cells, whereas potassium-induced secretion was 6-fold higher. In permeabilized Syt III cells, Ca 2؉ -induced and mastoparan-induced insulin secretion was also increased. In Syt VII-overexpressing RINm5F -cells, there was amplification of carbachol-induced insulin secretion in intact cells and of Ca 2؉ -induced and mastoparan-induced insulin secretion in permeabilized cells. In conclusion, Syt III/VII are located in insulincontaining secretory granules, and we suggest that Syt III/VII may be the Ca 2؉ sensor or one of the Ca 2؉ sensors for insulin exocytosis of the -cell.Insulin exocytosis from the -cell of the islets of Langerhans is stimulated by various physiological secretagogues that include glucose, amino acids, and receptor-mediated agonists such as acetylcholine, cholecystokinin, and glucagon like-peptide 1 (1-7). A common mechanism of action for these secretagogues is to cause an increase in cytosolic Ca 2ϩ . Elevation of intracellular Ca 2ϩ is due to an influx of extracellular Ca 2ϩ through voltage-dependent L-type Ca 2ϩ channel and/or mobilization of intracellular Ca 2ϩ from the endoplasmic reticulum (8 -17). However, the mechanisms by which Ca 2ϩ induces insulin granule fusion with the plasma membrane of -cell remain unclear (1,16,18,20,21).1 is a family of membrane proteins initially found to be expressed in brain. At the present, 11 members of Syt have been identified (22,23). The Syt molecule has a single transmembrane domain and two Ca 2ϩ regulatory C 2 domains. The C 2 domains mediate Ca 2ϩ -dependent and Ca 2ϩ -independent interactions with target molecules that may regulate membrane fusion and membrane budding reactions (24,25). Literature concerning the expression and functions of Syt in pancreatic -cell is very limited and contradictory. In an earlier study (26), Syt was found in the non--cell of the islet mantle, but not in the -cell, using a non-isoform-specific antibody, and the mRNAs of Syt A and B were absent in mouse pancreatic -cell and RINm5F cells as demonstrated by in situ hybridization...
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