Search

In larviculture of marine finfish, Tisochrysis lutea cultured cells have a potential to be a sustainable enrichment diet for rotifers due to its de novo synthesis of docosahexaenoic acid (DHA). To improve its effectiveness in rotifer enrichment for later larviculture, we determined which growth phase of T. lutea can enhance DHA in polar lipids (PLs) in Brachionus plicatilis sp. complex rotifers without reducing their vigor. Tisochrysis lutea was harvested at logarithmic growth phase, deceleration growth phase, and stationary phase. The ambient concentrations of phosphorus (P) and nitrogen (N), and fatty acid composition of microalgae were measured. P was limited between logarithmic and deceleration growth phases, followed by N starvation in stationary phase. Total lipid DHA was lowest in logarithmic growth phase, whereas DHA levels increased in deceleration growth phase and maintained at high levels even in stationary phase. PL-DHA also increased during deceleration growth phase, although its abundance dropped during stationary phase. In a rotifer enrichment trial, T. lutea harvested in each phase were fed to B. plicatilis sp. complex rotifers for 12 h. The highest PL-DHA value for cells in deceleration growth phase reflected the concentrations of the rotifers. No significant differences were found in rotifer growth rate and egg ratio. Rotifers fed cells in deceleration growth phase exhibited higher swimming speeds than those fed the other cells, potentially linking to increased larval capture success. Therefore, we recommend the deceleration growth phase as an optimal timing for T. lutea harvest for the effective enrichment of B. plicatilis sp. complex rotifers.

Mitochondrial dysfunction and lysosomal dysfunction have been implicated in Parkinson’s disease (PD), but the links between these dysfunctions in PD pathogenesis are still largely unknown. Here we report that cytosolic dsDNA of mitochondrial origin escaping from lysosomal degradation was shown to induce cytotoxicity in cultured cells and PD phenotypes in vivo. The depletion of PINK1, GBA and/or ATP13A2 causes increases in cytosolic dsDNA of mitochondrial origin and induces type I interferon (IFN) responses and cell death in cultured cell lines. These phenotypes are rescued by the overexpression of DNase II, a lysosomal DNase that degrades discarded mitochondrial DNA, or the depletion of IFI16, which acts as a sensor for cytosolic dsDNA of mitochondrial origin. Reducing the abundance of cytosolic dsDNA by overexpressing human DNase II ameliorates movement disorders and dopaminergic cell loss in gba mutant PD model zebrafish. Furthermore, IFI16 and cytosolic dsDNA puncta of mitochondrial origin accumulate in the brain of patients with PD. These results support a common causative role for the cytosolic leakage of mitochondrial DNA in PD pathogenesis., Mitochondrial and lysosomal dysfunction are central to Parkinson’s disease (PD) pathogenesis. Here, the authors show mitochondrial dsDNA in the cytosol in cellular and Zebrafish models of PD induces cytotoxicity and neurodegeneration; knock-down of IFI16, a cytosolic dsDNA sensor, rescues cytotoxicity, as does overexpression of lysosomal DNAse II.

Efficient production of beneficial metabolites by microalgae using light-emitting diodes (LED) is attracting more interest. In batch cultures, metabolic changes that occur with nutrient deficiency over time must be monitored to estimate the metabolite content. Our previous study showed that nutrient deficiency in Nannochloropsis oculata can be briefly evaluated by measuring the absorption ratio at 490 and 680 nm (Abs490/Abs680). However, little is known about the relation with this ratio and metabolic change, particularly in LED light-conditioned cultures. In this study, we investigate if Abs490/Abs680 can be an indicator of the biochemical status of N. oculata cultured under various LED color regimes. Three LED treatments were used: Blue (B), Blue + Red (BR), and Red (R). In all LED treatments, the Abs490/Abs680 decreased for several days and then increased when phosphate was limited or non-existent. The trends in the C16:0 and C20:5ɷ3 proportions and chlorophyll a content commonly changed at the turning points of the Abs490/Abs680. Furthermore, significant correlations were found among the metabolic state and absorption ratio, except in treatment R. We suggest that spectrophotometry can be used for monitoring metabolic changes in N. oculata cultures under various LED irradiance, unless there is excessive 630 nm-red light exposure.

Two common live feeds, the Brachionus plicatilis species complex SS-type and L-type were used to assess whether there were any differences in protein hydrolysis and digestive trypsin activity in first feeding Japanese flounder. There were no significant differences in hydrolysis activity at 2, 3 and 7 days after hatching (DAH). At 5 DAH, hydrolysis activity was significantly higher in larvae fed SS-type (p

Parkinson's disease is a neurodegenerative disorder that involves movement discloses, degeneration of dopaminergic neurons, and presence of cytoplasmic inclusion bodies. Various animal models have been developed and small fish including zebrafish and medaka fish have recently been employed as a new model for Parkinson disease. In this review, we summarize fish models of Parkinson's disease mainly using our own findings and explain two major hypotheses of PD: lysosome dysfunction theory and mitochondrial dysfunction theory. Finally, we discuss the potential for future application of small fish model.

The pathophysiology of depression and anxiety in Parkinson’s disease remains obscure. We aimed to compare the fractional anisotropy (FA) values of Parkinson’s disease (PD) patients with and without depression to investigate the nature of depression in PD. Twenty-eight patients were divided into two groups: those with depression and those without. Diagnosis of depression was made using the DSM-IV criteria. Patients in the two groups were matched for Hoehn Yahr stage. There were significant reductions in FA values in the bilateral frontal ROIs possibly representing anterior cingulate bundles. The anterior cingulate bundles play an important role in depression in PD, and some aspects of depression in PD have pathological processes in common with de novo depression.

Background: Decreased cardiac metaiodobenzylguanidine (MIBG) uptake was reported in Parkinson’s disease and this contributes to the differential diagnosis between Parkinson’s disease and other forms of parkinsonism such as multiple system atrophy. However, decreased MIBG uptake of the thyroid has not been demonstrated. Objective: To compare MIBG uptake of the thyroid among Parkinson’s disease, multiple system atrophy and controls. Methods: Twenty-six patients with Parkinson’s disease, 11 patients with multiple system atrophy and 14 controls were examined in this study. Planar images were taken 15 minutes (early images) and 3 hours (late images) after intravenous injection of 111 MBq 123 I-MIBG. Results: MIBG uptake of the thyroid on early images decreased significantly in Parkinson’s disease compared to controls (p < 0.0001) and multiple system atrophy (p = 0.018). MIBG uptake of the thyroid on early images decreased significantly also in multiple system atrophy compared to controls (p = 0.027). On late images, thyroid uptake differed significantly only between Parkinson’s disease and controls (p = 0.010). Conclusions: Our study is the first to demonstrate decreased MIBG uptake of the thyroid in Parkinson’s disease. Sympathetic nervous denervation of Parkinson’s disease occurred not only in the heart but also in the thyroid.