Potential impact of polyethylene microplastics on the growth of water spinach (Ipomoea aquatica F.): Endophyte and rhizosphere effects.

Microplastic contamination has received much attention, especially in agroecosystems. However, since edible crops with different genetic backgrounds may present different responses to microplastics, more research should be conducted and focused on more edible crops. In the current study, pot experiments were conducted to investigate the potential impact of polyethylene microplastic (PE) (particle sizes: 0.5 µm and 1.0 µm, addition levels: 0 (control), 0.5% and 1.0% (w/w)) addition on the physiological and biochemical variations of I. aquatica F.. The results indicated that PE addition caused an increase in the soil pH and NH4+-N and soil organic matter contents, which increased by 10.1%, 29.9% and 50.1% when PE addition at A10P0.5 level (10 g (PE) kg-1 soil, particle size: 0.5 µm). While, PE exposure resulted in a decrease in soil available phosphorus and total phosphorus contents, which decreased by 53.9% and 10.5% when PE addition at A10P0.5 level. In addition, PE addition altered the soil enzyme activities. Two-way ANOVA indicated that particle size had a greater impact on the variations in soil properties and enzyme activities than the addition level. PE addition had a strong impact on the rhizosphere microbial and root endophyte community diversity and structure of I. aquatica F.. Two-way ANOVA results indicated that the particle size and addition level significantly altered the α-diversity indices of both rhizosphere microbial and root endophyte (P < 0.05, P < 0.01 or P < 0.001). Moreover, PE was adsorbed by I. aquatica F., which was clearly observed in the transverse roots and significantly increased the H2O2, ·O2-, malondialdehyde and ascorbic acid contents in both the roots and aerial parts of I. aquatica F., leading to a decrease in I. aquatica F. biomass. Overall, the current study enriches the understanding of the effect of microplastics on edible crops.

Melatonin Attenuates Vascular Smooth Muscle Contraction Through the γ-Secretase/Notch Intracellular Domain/Myocardin Pathway.

ABSTRACT: Inositol 1, 4, 5-trisphosphate (IP3) signaling-mediated calcium release drives the contraction of vascular smooth muscles and hence regulates blood vessel volume and blood pressure. Melatonin supplementation has been suggested to be beneficial for hypertension. To determine whether the blood pressure-lowering effect of melatonin was accounted for by IP3 signaling, we evaluated the vasoconstriction response and IP3 signaling in isolated mouse thoracic aortic rings during melatonin incubation. C57BL/6 mice were given intraperitoneal injections daily with melatonin, and the systolic blood pressure and contractility of aortic rings from melatonin-treated mice were decreased, and the contraction suppression effect of melatonin was attributed to the impaired expression of contractile proteins in vascular smooth muscle cells rather than IP3 signaling. Our results further showed that melatonin increased the expression of γ-secretase, which could cleave and release the notch intracellular domain, and the notch intracellular domain prevented the transcription of contractile genes by interfering with the interaction between serum response factor and myocardin, the master regulator of contractile protein. In this article, we report a novel mechanism by which melatonin regulates smooth muscle contractility that does not depend on IP3 signaling.

Mechanism of Action of Acupotomy in Inhibiting Chondrocyte Apoptosis in Rabbits with KOA through the PI3K/Akt Signaling Pathway.

OBJECTIVE: We examined the effects of acupotomy on the PI3K/Akt signaling pathway to elucidate the mechanism of action of acupotomy on articular chondrocyte apoptosis among rabbits with knee osteoarthritis (KOA). METHODS: New Zealand rabbits were randomly assigned to a healthy control group, placebo group, acupotomy group, and drug group, with 10 rabbits in each group. Changes in chondrocytes were examined by hematoxylin and eosin staining, and articular chondrocyte apoptosis was measured by electron microscopy and immunofluorescence. The mRNA and protein expression levels of PI3K and Akt were measured by real-time quantitative PCR and Western blot. RESULTS: In contrast, less chromatin margination and clear and smooth nuclear envelope boundary were visible in the acupotomy group and drug group. The number of apoptotic chondrocytes in the knee joint of rabbits was significantly higher in the placebo group than that in the acupotomy group and drug group (P < 0.05). The acupotomy group had a nonsignificantly lower number of apoptotic chondrocytes than the drug group (P > 0.05). Furthermore, the mRNA and protein expression levels of PI3K and Akt were significantly higher in the acupotomy group and drug group than those in the placebo group (P < 0.05) and were closer to normal levels in the acupotomy group than those in the drug group (P < 0.05). PI3K and Akt expression levels were negatively correlated with chondrocyte apoptosis in the knee joint of rabbits in all groups. CONCLUSION: Inhibiting chondrocyte apoptosis in the knee joint of KOA rabbits by upregulating the PI3K/Akt signaling pathway may be a possible mechanism of acupotomy in treating KOA.

A Review of Functional Electrical Stimulation Treatment in Spinal Cord Injury.

Functional electrical stimulation (FES) has been widely adopted to elicit muscle contraction in rehabilitation training after spinal cord injury (SCI). Conventional FES modalities include stimulations coupled with rowing, cycling, assisted walking and other derivatives. In this review, we studied thirteen clinical reports from the past 5 years and evaluated the effects of various FES aided rehabilitation plans on the functional recovery after SCI, highlighting upper and lower extremity strength, cardiopulmonary function, and balder control. We further explored potential mechanisms of FES using the Hebbian theory and lumbar locomotor central pattern generators. Overall, FES can be used to improve respiration, circulation, hand strength, mobility, and metabolism after SCI.

Effects of oral monosodium glutamate administration on serum metabolomics of suckling piglets.

This study was conducted to determine the effects of oral administration with glutamate on metabolism of suckling piglets based on 1 H-Nuclear magnetic resonance (1 H NMR) spectroscopy through the level of metabolism. Forty-eight healthy [(Yorkshire × Landrace) × Duroc] piglets born on the same day with a similar birth bodyweight (1.55 ± 0.20 kg) were obtained from six sows (8 piglets per sow). The piglets from each sow were randomly assigned into four treatments (2 piglets per treatment). The piglets were given 0.09 g/kg body weight (BW) of sodium chloride (CN group), 0.03 g/kg BW monosodium glutamate (LMG group), 0.25 g/kg BW monosodium glutamate (MMG group) and 0.50 g/kg BW monosodium glutamate (HMG group) twice a day respectively. An 1 H NMR-based metabolomics' study found that the addition of monosodium glutamate (MSG) significantly reduced serum citrate content in 7-day-old piglets, while HMG significantly increased serum trimethylamine content and significantly reduced unsaturated fat content in 7-day-old piglets (p < .05). The content of glutamine, trimethylamine, albumin, choline and urea nitrogen was significantly increased and the creatinine content decreased significantly in the 21-day-old HMG (p < .05). Analysis of serum hormones revealed that glucagon-like peptide-1 (GLP-1) content in the 21-day-old HMG was highest (p < .05). The cholecystokinin (CCK) content in the HMG of 7-day-old piglets was lower than that in the LMG (p < .05), and the CCK content in the serum of the 21-day-old MMG was highest (p < .05). The serum leptin levels in the 21-day-old HMG were the lowest (p < .05). The serum insulin content in the 7-day-old MMG was highest (p < .05). This study suggests that MSG plays an important role in the metabolism of sugar, fat and protein (amino acids). These results provide a theoretical basis for designing piglet feed formulations.

An Injectable, Bifunctional Hydrogel with Photothermal Effects for Tumor Therapy and Bone Regeneration.

Significant attention has been focused on bone tumor therapy recently. At present, the treatment in clinic typically requires surgical intervention. However, a few tumor cells remain around bone defects after surgery and subsequently proliferate within several days. Thus, fabrication of biomaterials with dual functions of tumor therapy and bone regeneration is significant. Herein, the injectable hydrogel containing cisplatin (DDP) and polydopamine-decorated nano-hydroxyapatite is prepared via Schiff base reaction between the aldehyde groups on oxidized sodium alginate and amino groups on chitosan. The hydrogel exhibits sustained release properties for DDP due to the immobilization of DDP via abundant functional groups on polydopamine (PDA). Additionally, given the intense absorption of PDA in the near-infrared region, the hydrogel exhibits excellent photothermal effects when exposed to the NIR laser (808 nm). Based on the properties, the hydrogel effectively ablates tumor cells (4T1 cells) in vitro and suppresses tumor growth in vivo. Furthermore, the hydrogel promotes the adhesion and proliferation of bone mesenchymal stem cells in vitro due to the abundant functional groups on PDA and further induces bone regeneration in vivo. Therefore, the study extends research on novel biomaterials with dual functions of tumor therapy and bone regeneration.