Mitochondria from cultured cells derived from normal and thiamine-responsive megaloblastic anemia individuals efficiently import thiamine diphosphate

BACKGROUND: Thiamine diphosphate (ThDP) is the active form of thiamine, and it serves as a cofactor for several enzymes, both cytosolic and mitochondrial. Isolated mitochondria have been shown to take up thiamine yet thiamine diphosphokinase is cytosolic and not present in mitochondria. Previous reports indicate that ThDP can also be taken up by rat mitochondria, but the kinetic constants associated with such uptake seemed not to be physiologically relevant. RESULTS: Here we examine ThDP uptake by mitochondria from several human cell types, including cells from patients with thiamine-responsive megaloblastic anemia (TRMA) that lack a functional thiamine transporter of the plasma membrane. Although mitochondria from normal lymphoblasts took up thiamine in the low micromolar range, surprisingly mitochondria from TRMA lymphoblasts lacked this uptake component. ThDP was taken up efficiently by mitochondria isolated from either normal or TRMA lymphoblasts. Uptake was saturable and biphasic with a high affinity component characterized by a K(m) of 0.4 to 0.6 μM. Mitochondria from other cell types possessed a similar high affinity uptake component with variation seen in uptake capacity as revealed by differences in V(max) values. CONCLUSIONS: The results suggest a shared thiamine transporter for mitochondria and the plasma membrane. Additionally, a high affinity component of ThDP uptake by mitochondria was identified with the apparent affinity constant less than the estimates of the cytosolic concentration of free ThDP. This finding indicates that the high affinity uptake is physiologically significant and may represent the main mechanism for supplying phosphorylated thiamine for mitochondrial enzymes

Dopamine and Serotonin Modulate Free Amino Acids Production and Na+/K+ Pump Activity in Chinese Mitten Crab Eriocheir sinensis Under Acute Salinity Stress

The Chinese mitten crab Eriocheir sinensis lives in saline or fresh water during different life stages and exhibits a complex life history, making it an ideal model to study the salinity adaptation of euryhaline animals. In this study, RNA-seq techniques, and determinations of free amino acids (FAAs), monoamine neurotransmitters, and Na+/K+ pump activity, were employed to understand the osmoregulatory mechanism in Chinese mitten crab. A total of 15,138 differentially expressed genes were obtained from 12 transcriptome libraries. GO enrichment analysis revealed that the mRNA expression profiles were completely remodeled from 12 to 24 h after salinity stress. The neuroendocrine system was activated under stimulation, and the monoamine neurotransmitters including dopamine (DA) and serotonin (5-HT) were released to modulate osmoregulation. Furthermore, the Na+/K+ pump in crab hemocytes was significantly inhibited post salinity stress, resulting in increased intracellular ion concentrations and osmotic pressure to sustain the osmotic balance. Moreover, six key FAAs, including alanine (Ala), proline (Pro), glycine (Gly), glutamate (Glu), arginine (Arg), and aspartate (Asp), were overexpressed to modulate the extracellular osmotic balance during salinity adaptation. Interestingly, the immune genes were not enriched in the GO analysis, implying that the immune system might not contribute fundamentally to the tolerance upon fluctuating ambient salinity in the Chinese mitten crab. These results collectively demonstrated that the Chinese mitten crab had evolved an efficient regulation mechanism by modulating the FAAs production and Na+/K+ pump activity to sustain the osmotic balance independent of the immune system, in which the neuroendocrine modulation, especially generated by the monoamine neurotransmitter, played an indispensable role

RNA-Seq Analyses of Midgut and Fat Body Tissues Reveal the Molecular Mechanism Underlying Spodoptera litura Resistance to Tomatine

Plants produce secondary metabolites to provide chemical defense against herbivorous insects, whereas insects can induce the expression of detoxification metabolism-related unigenes in counter defense to plant xenobiotics. Tomatine is an important secondary metabolite in tomato (Lycopersicon esculentum L.) that can protect the plant from bacteria and insects. However, the mechanism underlying the adaptation of Spodoptera litura, a major tomato pest, to tomatine in tomato is largely unclear. In this study, we first found that the levels of tomatine in tomatoes subjected to S. litura treatment were significantly increased. Second, we confirmed the inhibitory effect of tomatine on S. litura by adding moderate amounts of commercial tomatine to an artificial diet. Then, we utilized RNA-Seq to compare the differentially expressed genes (DEGs) in the midgut and fat body tissues of S. litura exposed to an artificial diet supplemented with tomatine. In total, upon exposure to tomatine, 134 and 666 genes were upregulated in the S. litura midgut and fat body, respectively. These DEGs comprise a significant number of detoxification-related genes, including 7 P450 family genes, 8 glutathione S-transferases (GSTs) genes, 6 ABC transport enzyme genes, 9 UDP-glucosyltransferases genes and 3 carboxylesterases genes. Moreover, KEGG analysis demonstrated that the upregulated genes were enriched in xenobiotic metabolism by cytochrome P450s, ABC transporters and drug metabolism by other enzymes. Furthermore, as numerous GSTs were induced by tomatine in S. litura, we chose one gene, namely GSTS1, to confirm the detoxification function on tomatine. Expression profiling revealed that GSTS1 transcripts were mainly expressed in larvae, and the levels were the highest in the midgut. Finally, when larvae were injected with double-stranded RNA specific to GSTS1, the transcript levels in the midgut and fat body decreased, and the negative effect of the plant xenobiotic tomatine on larval growth was magnified. These results preliminarily clarified the molecular mechanism underlying the resistance of S. litura to tomatine, establishing a foundation for subsequent pest control

Enrichment and characteristics of ammonia-oxidizing archaea in wastewater treatment process

High purity ammonia-oxidizing archaea (AOA) culture containing a single AOA strain was enriched from the filtering materials of biological aerated filter. The concentration of AOA reached 3.27\ua0×\ua010\ua0copies/mL, while its proportion was 91.40%. The AOA amoA gene sequence belonged to Nitrososphaera cluster. Ammonia concentration significantly influenced the growth of AOA in culture, while total organic carbon (TOC) concentration had no obvious effect. The optimum ammonia concentration, temperature, pH and DO concentration for growth of AOA were 1\ua0mM, 30\ua0°C, 7.5 and 2.65\ua0mg/L, respectively. Under the optimum growth conditions, the AOA abundance and ammonia oxidation rate were 3.53\ua0×\ua010\ua0copies/mL and 2.54\ua0×\ua010\ua0mg/(copies·d)

A heterozygous moth genome provides insights into herbivory and detoxification

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants1, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood2. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.Minsheng You … Simon W Baxter … et al

Positive solutions of fractional differential equations involving the Riemann–Stieltjes integral boundary condition

Abstract In this article, the following boundary value problem of fractional differential equation with Riemann–Stieltjes integral boundary condition {D0+αu(t)+λf(t,u(t),u(t))=0,00 $\lambda>0$, D0+α $D_{0+}^{\alpha}$ is the Riemann–Liouville fractional derivative, A is a function of bounded variation, ∫01u(s)dA(s) $\int_{0}^{1}u(s)\,dA(s)$ denotes the Riemann–Stieltjes integral of u with respect to A. By the use of fixed point theorem and the properties of mixed monotone operator theory, the existence and uniqueness of positive solutions for the problem are acquired. Some examples are presented to illustrate the main result

Real-Time Monitoring Method of Strawberry Fruit Growth State Based on YOLO Improved Model

A key challenge in automated orchard management robots is the fast and accurate identification of crop growth conditions and maturity for subsequent operations such as automatic pollination, fertilization and picking. In particular, strawberry fruits have a short ripening period and the fruits are heavily overlapped and shaded by each other, which is time-consuming and ineffective based on traditional detection methods. Therefore, we designed and developed a strawberry growth detection algorithm, SDNet (Strawberry Detect Net). The algorithm is based on the YOLOX model and replaces the original CSP block in the backbone network with a self-designed feature extraction module C3HB block to improve the spatial interaction capability and monitoring accuracy of the detection algorithm; Then, the normalized attention module (NAM) is embedded in the neck to improve the detection accuracy and attention weight of small target fruits; and we use the latest SIOU objective loss function to improve the prediction accuracy of the detection model, which finally achieves the monitoring of strawberry fruits under five growth states. The experimental results show that the precision, accuracy, and recall of SDNet are 94.26%, 93.15%, and 90.72%, respectively, and the monitoring speed is 30.5 ms. It is 4.08%, 3.64 and 2.04% higher than the precision, accuracy, and recall of YOLOX, respectively, and there is no significant change in the model size. The research results can effectively solve the problem of low accuracy of strawberry fruit growth state monitoring under complex environments, and provide important technical reference for realizing unmanned farm and precision agriculture

Improving Post-Anaerobic Digestion of Full-Scale Anaerobic Digestate Using Free Ammonia Treatment

Post-anaerobic digestion of full-scale anaerobic digestate (AD) is used in enhancing sludge reduction in some sewage treatment plants (STPs). However, the AD degradation is usually inhibited due to its slow hydrolysis rate and low degradability. This study presents an innovative pretreatment method by using free ammonia (FA, i.e., NH3) to improve post-anaerobic digestion full-scale AD degradation. The FA treatment at over 360 mg NH3-N/L for 24 h has improved AD degradation with the highest solubilization (0.1 mg chemical oxygen demand (COD)/mg volatile solids (VS), at 850 mg NH3-N/L), being 5.3 times that without pretreatment (0.019 mg COD/mg VS). After 8 days of post anaerobic digestion, non-pretreated AD has degraded 8.5%, while the FA pretreated AD at 360-850 mg NH3-N/L has degraded 9.9-10.9%, representing a relative increase of 14-22%. The mathematical model captured the tested data well with R-2 &gt; 0.994 in all cases, and the model revealed that AD degradation improvement was attributed to an increase in AD degradation percentage. Economic analysis shows that the FA pretreatment method could be economically favorable in enhancing full-scale AD post-anaerobic digestion.</p