Repeated febrile convulsions impair hippocampal neurons and cause synaptic damage in immature rats: neuroprotective effect of fructose-1,6-diphosphate

Fructose-1,6-diphosphate is a metabolic intermediate that promotes cell metabolism. We hypothesize that fructose-1,6-diphosphate can protect against neuronal damage induced by febrile convulsions. Hot-water bathing was used to establish a repetitive febrile convulsion model in rats aged 21 days, equivalent to 3–5 years in humans. Ninety minutes before each seizure induction, rats received an intraperitoneal injection of low- or high-dose fructose-1,6-diphosphate（500 or 1,000 mg/kg, respectively）. Low- and high-dose fructose-1,6-diphosphate prolonged the latency and shortened the duration of seizures. Furthermore, high-dose fructose-1,6-diphosphate effectively reduced seizure severity. Transmission electron microscopy revealed that 24 hours after the last seizure, high-dose fructose-1,6-diphosphate reduced mitochondrial swelling, rough endoplasmic reticulum degranulation, Golgi dilation and synaptic cleft size, and increased synaptic active zone length, postsynaptic density thickness, and synaptic interface curvature in the hippocampal CA1 area. The present findings suggest that fructose-1,6-diphosphate is a neuroprotectant against hippocampal neuron and synapse damage induced by repeated febrile convulsion in immature rats.

Overexpression of Brassica napus cytosolic fructose-1,6-bisphosphatase and sedoheptulose-1,7-bisphosphatase genes significantly enhanced tobacco growth and biomass

Elevated activities of cytosolic fructose-1,6-bisphosphatase(cyFBPase) and sedoheptulose-1,7-bisphosphatase(SBPase)are associated with higher yields in plants. In this study, the expression levels of the cyFBPase and SBPase genes were increased by overexpressing rape(Brassica napus) cDNA in tobacco(Nicotiana tabacum) plants. The transgenic plants coexpressing cy FBPase and SBPase(TpFS), or expressing single cy FBPase(TpF) or SBPase(TpS) had 1.77-, 1.55-, 1.23-fold cyFBPase and 1.45-, 1.12-, 1.36-fold SBPase activities as compared to the wild-type(WT), respectively. Photosynthesis rates of TpF, TpS and TpFS increased 4, 20 and 25% compared with WT plants. The SBPase and cyFBPase positively regulated each other and functioned synergistically in transgenic tobacco plants. In addition, the sucrose contents of the three transgenic plants were higher than that of WT plants. The starch accumulation of the TpFS and TpS plants was improved by 53 and 37%, but slightly decreased in TpF plants. Moreover, the transgenic tobacco plants harbouring SBPase and/or cyFBPase genes showed improvements in their growth, biomass, dry weight, plant height, stem diameter, leaf size,flower number, and pod weight. In conclusion, co-expression of SBPase and cyFBPase may pave a new way for improving crop yield in agricultural applications.

The Effect of Fructose-1,6-diphosphate and HTK Solution on Protecting Primary Cardiac Muscle Cells of Rat with Cold Preservation

In this study we tried to investigate the effect of fructose-1,6-diphosphate and HTK solution on protecting primary cardiac muscle cells of rat with cold preservation. The primary cardiac muscle cells of rat were cultured in vitro with four preservation solutions respectively: 0.9 % sodium chloride solution (group A), FDP (group B), HTK solution (group C) and a mixture of FDP and HTK solution (group D). The cells were preserved for 6, 8 and 10 h at 0-4 ℃. The values of AST and LDH-L and the Na+-K+ ATPase activity in cardiac muscle cells were detected, and the survival rate of cardiac muscle cells was detected with trypan blue staining. The values of AST and LDH-L in group C and group D were remarkable lower those in group A and group B (P<0.001), while the Na+-K+ ATPase activity and the survival rate of cells in group C and group D were much higher than those in group A and group B (P<0.001). The values of AST and LDH-L after 6 hours in group D decreased much more than those in group C (P<0.01), while the Na+-K+ ATPase activity and the survival rate of cells in group D improved more than those in group C (P<0.01). Both of the HTK solution and the mixture of HTK and FDP solution have an evident effect on protecting the primary cardiac muscle cells of rat in vitro with cold preservation, Compared with the HTK solution, the mixture solution has a better short-term protective effect.

Status epilepticus due to fructose-1,6-bisphosphatase deficiency caused by FBP1 gene mutation

Introduction:Fructose-1,6-bisphosphatase (FBPase) deficiency is a rare inherited disorder in gluconeogenesis,characterized by hypoglycemia,ketonuria,metabolic acidosis and convulsions.Case presentation:We describe two brothers with FBPase deficiency.The proband developed severe hypoglycemia and progressed to status epilepticus,and the brother showed slightly hypoglycemia with a good prognosis.Whole exome sequencing (WES) identified compound heterozygous variants [c.333+1333+2delinsTC and c.490G>A (p.Gly164Ser)] in fructose-1,6-bisphosphatase 1 gene in the two brothers,which were inherited from the father and the mother,respectively.Conclusion:Genetic analysis provided a solid basis for a definite diagnosis and the determination of precision therapies for the patient.

The effect of stunned myocardium on heart function and the protection of fructose－1，6－diphosphate on it

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Vacuole import and degradation pathway: Insights into a specialized autophagy pathway

Glucose deprivation induces the synthesis of pivotagluconeogenic enzymes such as fructose-1,6-bisphos-phatase, malate dehydrogenase, phosphoenolpyruvatecarboxykinase and isocitrate lyase in Saccharomycescerevisiae. However, following glucose replenishment,these gluconeogenic enzymes are inactivated and de-graded. Studies have characterized the mechanismsby which these enzymes are inactivated in response toglucose. The site of degradation of these proteins hasalso been ascertained to be dependent on the dura-tion of starvation. Glucose replenishment of short-termstarved cells results in these proteins being degradedin the proteasome. In contrast, addition of glucose tocells starved for a prolonged period results in theseproteins being degraded in the vacuole. In the vacuoledependent pathway, these proteins are sequestered inspecialized vesicles termed vacuole import and degra-dation (Vid). These vesicles converge with the endo-cytic pathway and deliver their cargo to the vacuolefor degradation. Recent studies have identified thatinternalization, as mediated by actin polymerization, isessential for delivery of cargo proteins to the vacuolefor degradation. In addition, components of the targetof rapamycin complex 1 interact with cargo proteins during glucose starvation. Furthermore, Tor1p dissoci-ates from cargo proteins following glucose replenish-ment. Future studies will be needed to elaborate on the importance of internalization at the plasma membrane and the subsequent import of cargo proteins into Vid vesicles in the vacuole dependent degradation pathway.