Nitrate reduces copper toxicity by preventing oxidative stress and inhibiting copper translocation from roots to shoots in Liriodendron Chinense.

Nitrogen forms can affect metal accumulation in plants and tolerance to metals, but a few published studies on the effects on Cu toxicity and Cu accumulation in plants are scarce. Thus, the objective of this study was to evaluate the responses of Liriodendron chinense to different nitrogen forms, by the oxidative stress, antioxidant enzymes system, GSH-AsA cycle, Cu uptake, translocation, and accumulation under Cu stress. We found that Cu-induced growth inhibiting was alleviated by added exclusive NO3--N. Adding N as NH4+-N with or without NO3--N was aggravated as evidenced by significantly elevated malonaldehyde (MDA) and hydrogen peroxide (H2O2) compared to N-Null. Cu exposure and adding NH4+-N inhibited superoxide dismutase activity, but remarkably stimulated the activities of catalase and peroxidase, the efficiency of glutathione-ascorbate (GSH-AsA) cycle, and the activity of glutathione reductase and nitrate reductase, with respect to the control. However, adding exclusive NO3--N progressively restored the alteration of antioxidant to prevent Cu-induced oxidative stress. Additionally, adding exclusive NO3--N significantly promoted the Cu uptake and accumulation in roots, but reduced Cu concentration in leaves, accompanied by the inhibited Cu translocation factor from roots to shoots by 36.7%, when compared with N-Null. Overall, adding NO3--N alleviated its Cu toxicity by preventing Cu-induced oxidative stress and inhibiting Cu translocation from roots to shoots, which provides an effective strategy for phytostabilization in Cu-contaminated lands.

H2S alleviates renal ischemia and reperfusion injury by suppressing ERS-induced autophagy.

BACKGROUND: Ischemia/reperfusion injury (IRI) can lead to acute kidney injury and result in high disability and mortality rates. Cystathionine γ-lyase (CSE)-produced hydrogen sulfide (H2S) has been confirmed to play a protective role in renal IRI. While autophagy is involved in renal IRI, its role in the regulation by endoplasmic reticulum stress (ERS) has not been considered. Our study explored the role of CSE/H2S in protecting against renal IRI by regulating ERS-induced autophagy. METHODS: C57/BL6 mice were subjected to 30-min renal ischemia followed by .24-h reperfusion injury (IRI). The H2S donor sodium hydrosulfide hydrate (NaHS) or the CSE inhibitor D,L-propargylglycine (PAG) was injected intraperitoneally (i.p) into the mice. Serum creatinine and urea nitrogen levels were analyzed to evaluate renal function. Renal tubule epithelial cell damage was measured by HE and PAS staining. ERS and microtubule-associated protein light chain 3 (LC3) autophagy (LC3-I to LC3-II conversion) were analyzed by using western blotting. RESULTS: In a C57/BL6 mouse model of acute renal IRI, the application of IRI impaired the renal function, which was accompanied by elevated serum creatinine (P < 0.001) and urea nitrogen levels (P < 0.001). While NaHS pretreatment dramatically attenuated renal IRI, PAG administration exacerbated renal IRI (P < 0.001). Furthermore, NaHS treatment inhibited the ERS-induced increased LC3II/I protein ratio (P < 0.001); increased Beclin-1 protein expression (P < 0.001); PAG pretreatment exacerbated the effects of ERS on both the LC3II/I ratio (P < 0.001) and the Beclin-1 protein expression (P < 0.001). CONCLUSIONS: Our results suggest that the CSE/H2S system is an important therapeutic target for protecting against renal IRI, and it may protect renal tubule epithelial cells from IRI by suppressing ERS-induced autophagy.

Use of oxygen-loaded nanobubbles to improve tissue oxygenation: Bone-relevant mechanisms of action and effects on osteoclast differentiation.

Gas-loaded nanobubbles have potential as a method of oxygen delivery to increase tumour oxygenation and therapeutically alleviate tumour hypoxia. However, the mechanism(s) whereby oxygen-loaded nanobubbles increase tumour oxygenation are unknown; with their calculated oxygen-carrying capacity being insufficient to explain this effect. Intra-tumoural hypoxia is a prime therapeutic target, at least partly due to hypoxia-dependent stimulation of the formation and function of bone-resorbing osteoclasts which establish metastatic cells in bone. This study aims to investigate potential mechanism(s) of oxygen delivery and in particular the possible use of oxygen-loaded nanobubbles in preventing bone metastasis via effects on osteoclasts. Lecithin-based nanobubbles preferentially interacted with phagocytic cells (monocytes, osteoclasts) via a combination of lipid transfer, clathrin-dependent endocytosis and phagocytosis. This interaction caused general suppression of osteoclast differentiation via inhibition of cell fusion. Additionally, repeat exposure to oxygen-loaded nanobubbles inhibited osteoclast formation to a greater extent than nitrogen-loaded nanobubbles. This gas-dependent effect was driven by differential effects on the fusion of mononuclear precursor cells to form pre-osteoclasts, partly due to elevated potentiation of RANKL-induced ROS by nitrogen-loaded nanobubbles. Our findings suggest that oxygen-loaded nanobubbles could represent a promising therapeutic strategy for cancer therapy; reducing osteoclast formation and therefore bone metastasis via preferential interaction with monocytes/macrophages within the tumour and bone microenvironment, in addition to known effects of directly improving tumour oxygenation.

Effects of low nitrogen on seedling growth, photosynthetic characteristics and antioxidant system of rice varieties with different nitrogen efficiencies.

Nitrogen plays a significant role in influencing various physiological processes in plants, thereby impacting their ability to withstand abiotic stresses. This study used hydroponics to compare the effects of three nitrogen supply levels (1N, 1/2N and 1/4N) on the antioxidant capacity of rice varieties JJ88 (nitrogen efficient) and XN999 (nitrogen inefficient) with different nitrogen use efficiencies. The results show that compared with the XN999 variety, the JJ88 variety has stronger adaptability to low-nitrogen conditions, which is mainly reflected in the relatively small decrease in dry weight and net photosynthetic rate (Pn); In the early stage of low-nitrogen treatment (0-7 d), the [Formula: see text] production rate, hydrogen peroxide (H2O2) and malondialdehyde (MDA) content of JJ88 variety increased relatively slightly, but the superoxide dismutase (SOD), peroxide The activity of enzyme (POD) and catalase (CAT) increased significantly; After low-nitrogen treatment, the ASA-GSH cycle enzyme activity of JJ88 variety was relatively high, and the dehydroascorbate reductase (DHAR) activity after 14 days of low-nitrogen treatment was higher than that of 1N treatment; The content of reduced ascorbic acid (ASA) in non-enzymatic antioxidants was lower than that of 1N treatment after 14 days of low nitrogen treatment; The contents of oxidized dehydroascorbic acid (DHA) and carotenoids (Car) were higher than those of 1N treatment after 21d and 14d of low nitrogen treatment respectively; The contents of reduced glutathione (GSH), oxidized glutathione (GSSG) and proline (Pro) showed a larger upward trend during the entire low-nitrogen treatment period. In summary, the JJ88 rice variety has a strong ability to regulate oxidative stress and osmotic damage under low nitrogen conditions. It can slow down plant damage by regulating antioxidant enzyme activity and antioxidant content. This provides a basis for achieving nitrogen reduction and efficiency improvement in rice and the breeding of nitrogen-efficient varieties.

Synergistic mitigation of nickel toxicity in pepper (Capsicum annuum) by nitric oxide and thiourea via regulation of nitrogen metabolism and subcellular nickel distribution.

Nickel (Ni) contamination hinders plant growth and yield. Nitric oxide (NO) and thiourea (Thi) aid plant recovery from heavy metal damage, but their combined effects on pepper (Capsicum annuum ) plant tolerance to Ni stress need more study. Sodium nitroprusside (0.1mM, SNP) and 400mgL-1 Thi, alone and combined, were studied for their impact on pepper growth under Ni toxicity. Ni stress reduces chlorophyll, PSII efficiency and leaf water and sugar content. However, SNP and Thi alleviate these effects by increasing leaf water, proline and sugar content. It also increased the activities of superoxide dismutase, catalase, ascorbate peroxidase and peroxidase. Nickel stress lowered nitrogen assimilation enzymes (nitrate reductase, nitrite reductase, glutamine synthetase, glutamate synthase and glutamate dehydrogenase) and protein content, but increased nitrate, ammonium and amino acid content. SNP and Thi enhanced nitrogen assimilation, increased protein content and improved pepper plant growth and physiological functions during Ni stress. The combined treatment reduced Ni accumulation, increased Ni in leaf cell walls and potentially in root vacuoles, and decreased Ni concentration in cell organelles. It effectively mitigated Ni toxicity to vital organelles, surpassing the effects of SNP or Thi use alone. This study provides valuable insights for addressing heavy metal contamination in agricultural soils and offers potential strategies for sustainable and eco-friendly farming practices.

Nitrogen fertilization and arbuscular mycorrhizal fungi do not mitigate the adverse effects of soil contamination with polypropylene microfibers on maize growth.

Soil contamination with microplastics may adversely affect soil properties and functions and consequently crop productivity. In this study, we wanted to verify whether the adverse effects of microplastics in the soil on maize plants (Zea mays L.) are due to a reduction in nitrogen (N) availability and a reduced capacity to establish symbiotic relationships with arbuscular mycorrhizal (AM) fungi. To do this, we performed a pot experiment in which a clayey soil was exposed to two environmentally relevant concentrations of polypropylene (PP; one of the most used plastic materials) microfibers (0.4% and 0.8% w/w) with or without the addition of N fertilizer and with or without inoculation with AM fungi. The experiment began after the soil had been incubated at 23 °C for 5 months. Soil contamination with PP considerably reduced maize root and shoot biomass, leaf area, N uptake, and N content in tissue. The adverse effects increased with the concentration of PP in the soil. Adding N to the soil did not alleviate the detrimental effects of PP on plant growth, which suggests that other factors besides N availability played a major role. Similarly, although the presence of PP did not inhibit root colonization by AM fungi (no differences were observed for this trait between the uncontaminated and PP-contaminated soils), the addition of the fungal inoculum to the soil failed to mitigate the negative impact of PP on maize growth. Quite the opposite: mycorrhization further reduced maize root biomass accumulation. Undoubtedly, much research remains to be done to shed light on the mechanisms involved in determining plant behavior in microplastic-contaminated soils, which are most likely complex. This research is a priority given the magnitude of this contamination and its potential implications for human and environmental health.

Design, Synthesis, and Anti-Cervical Cancer and Reversal of Tumor Multidrug Resistance Activity of Novel Nitrogen-Containing Heterocyclic Chalcone Derivatives.

This study involved the design and synthesis of 21 new nitrogen-containing heterocyclic chalcone derivatives utilizing the active substructure splicing principle, with glycyrrhiza chalcone serving as the lead compound. The targets of these derivatives were VEGFR-2 and P-gp, and their efficacy against cervical cancer was evaluated. Following preliminary conformational analysis, compound 6f ((E)-1-(2-hydroxy-5-((4-hydroxypiperidin-1-yl)methyl)-4-methoxyphenyl)-3-(4-((4-methylpiperidin-1-yl)methyl)phenyl)prop-2-en-1-one) exhibited significant antiproliferative activity against human cervical cancer cells (HeLa and SiHa) with IC50 values of 6.52 ± 0.42 and 7.88 ± 0.52 µM, respectively, when compared to other compounds and positive control drugs. Additionally, this compound demonstrated lower toxicity towards human normal cervical epithelial cells (H8). Subsequent investigations have demonstrated that 6f exerts an inhibitory impact on VEGFR-2, as evidenced by its ability to impede the phosphorylation of p-VEGFR-2, p-PI3K, and p-Akt proteins in HeLa cells. This, in turn, results in the suppression of cell proliferation and the induction of both early and late apoptosis in a concentration-dependent manner. Furthermore, 6f significantly curtails the invasion and migration of HeLa cells. In addition, 6f had an IC50 of 7.74 ± 0.36 µM against human cervical cancer cisplatin-resistant HeLa/DDP cells and a resistance index (RI) of 1.19, compared to 7.36 for cisplatin HeLa cells. The combination of 6f and cisplatin resulted in a significant reduction in cisplatin resistance in HeLa/DDP cells. Molecular docking analyses revealed that 6f exhibited binding free energies of -9.074 and -9.823 kcal·mol-1 to VEGFR-2 and P-gp targets, respectively, and formed hydrogen bonding forces. These findings suggest that 6f has potential as an anti-cervical cancer agent and may reverse cisplatin-resistant activity in cervical cancer. The introduction of the 4-hydroxy piperidine and 4-methyl piperidine rings may contribute to its efficacy, and its mechanism of action may involve dual inhibition of VEGFR-2 and P-gp targets.

Cadmium accumulation responses in Hylotelephium spectabile: The role of photosynthetic characteristics under different nitrogen, moisture, and light conditions.

The influence of environmental factors on Cd accumulation by Hylotelephium spectabile and its physiological mechanisms are unclear. A field trial was conducted to investigate the effects of nitrogen, soil moisture, and light regulation on plant growth, Cd absorption and translocation, and the photosynthetic characteristics of two H. spectabile populations (LN with high Cd accumulation capacity and HB1 with relatively low Cd accumulation capacity). The results showed that Cd accumulation in LN was 59.6% higher than that in HB1 which may partly be explained by the inherent high transpiration rate of LN, especially at the terminal stage. In addition, the photosynthetic rate of LN responded more positively to nitrogen than HB1, which further amplified its advantages on plant growth and Cd accumulation. Moderate drought significantly stimulated root growth of LN, indicating that LN possesses stronger resistance to drought. Shade inhibited Cd distribution, rather than directly affecting Cd concentrations in H. spectabile. The combined stress of shade and drought had a synergistic effect on Cd translocation in H. spectabile. Moreover, LN achieved 17.3%∼444.5% higher transpiration levels than HB1 under environmental stress, which ensured a more efficient Cd transport capacity of LN. Therefore, the investigation of photosynthetic characteristics further revealed the physiological mechanism by which LN accumulated Cd superior to HB1 under environmental stress and responded more positively to nitrogen nutrition.

The effects of nitrogen and phosphorus nutrients on the bioremediation of oil-contaminated waters by Gracilariopsis persica in the coastal areas of Bandar Abbas.

This study investigated the influence of nitrogen and phosphorus on the bioremediation of crude oil by Gracilariopsis persica in littoral zone waters. In order to determine the role of nitrogen in bioremediation, urea, ammonium, and nitrate were used with and without phosphorus, with the result that nitrogen had no significant effect on the degradation of oil by Gracilariopsis persica in the littoral zone. Nearly 90 % of the crude oil used in this study was degraded by treatments with added phosphorus and nitrogen. A significant increase in the degradation of oil-contaminated water was observed after the application of phosphorus. Comparatively to the application of phosphorus alone, nitrogen and phosphorus together increased the rate of biodegradation by the algal species. Based on the results of the study, nitrogen and phosphorus have complementary effects on the bioremediation of oil by Gracilariopsis persica.

Copper-Nitrogen-Coordinated Carbon Dots: Transformable Phototheranostics from Precise PTT/PDT to Post-Treatment Imaging-Guided PDT for Residual Tumor Cells.

Phototheranostics has attracted considerable attention in the fields of cancer diagnosis and treatment. However, the complete eradication of solid tumors using traditional phototheranostics is difficult because of the limited depth and range of laser irradiation. New phototheranostics enabling precise phototherapy and post-treatment imaging-guided programmed therapy for residual tumors is urgently required. Accordingly, this study developed a novel transformable phototheranostics by assembling hyaluronic acid (HA) with copper-nitrogen-coordinated carbon dots (CDs). In this transformable nanoplatform, named copper-nitrogen-CDs@HA, the HA component enables the specific targeting of cluster determinant (CD) 44-overexpressing tumor cells. In the tumor cells, redox glutathione converts Cu(II) (cupric ions) into Cu(I) (cuprous ions), which confers the novel transformable functionality to phototheranostics. Both in vitro and in vivo results reveal that the near-infrared-light-photoactivated CuII-N-CDs@HA could target CD44-overexpressing tumor cells for precise synergistic photothermal therapy and photodynamic therapy. This study is the first to observe that CuII-N-CDs@HA could escape from lysosomes and be transformed in situ into CuI-N-CDs@HA in tumor cells, with the d9 electronic configuration of Cu(II) changing to the d10 electronic configuration of Cu(I), which turns on their fluorescence and turns off their photothermal properties. This transformable phototheranostics could be used for post-treatment imaging-guided photodynamic therapy on residual tumor cells. Thus, the rationally designed copper-nitrogen-coordinated CDs offer a simple in situ transformation strategy for using multiple-stimulus-responsive precise phototheranostics in post-treatment monitoring of residual tumor cells and imaging-guided programmed therapy.

Freezing nitrogen ethanol composite reduces periprosthetic infection caused by Staphylococcus aureus contaminated metal implants: An animal study.

BACKGROUND: Implant-associated infection remains a major complication of orthopedic surgery. The treatment of such infection is complicated by bacterial biofilm formation on the metal surfaces of implants. Biofilm surrounds and protects the bacteria against the organism's endogenous defense system and from external agents such as antibiotics and mechanical debridement. This study aims to evaluate whether freezing nitrogen ethanol composite (FNEC), the combination of liquid nitrogen and 95% ethanol in a 3 to 1 ratio, used frequently in bone tumor surgery, is capable of disinfecting Staphylococcus aureus contaminated implants. METHODS: The femurs of six New Zealand white rabbits were implanted with S. aureus-contaminated screws, half of which were treated with FNEC before implantation. The femurs were harvested 14 days after implantation. Histological analysis and TUNEL assay were conducted. The autoclaved screw, contaminated screw, and FNEC-treated contaminated screw were investigated using scanning electron microscopy to evaluate the biofilm structure. RESULTS: The FNEC-treated group had significantly lower relative C-reactive protein levels. An obvious periosteal reaction at the implant site was observed in all rabbits in the non-FNEC group but none was observed in the FNEC-treated group. The FNEC-treated group exhibited fewer empty lacunae, less inflammatory infiltration, and less bone necrosis. Immunohistochemical analysis showed no S. aureus in bone tissue from the FNEC-treated group. Scanning electron microscopy showed disruption of the biofilm on the contaminated screw treated with FNEC. CONCLUSION: FNEC showed potential in disinfecting S.aureus-contaminated implants. Further investigation is warranted, such as the effect on the implant-cement-bone interface, for FNEC to be used clinically in treating implant-associated infection.

Exogenous Hemin alleviates cadmium stress in maize by enhancing sucrose and nitrogen metabolism and regulating endogenous hormones.

Cadmium (Cd) stress restricts maize growth and productivity severely. We aimed to investigate the effects of Hemin on the metabolism of sucrose and nitrogen and endogenous hormones in maize under cadmium stress. Maize varieties 'Tiannong 9' (cadmium tolerant) and 'Fenghe 6' (cadmium sensitive) were grown in nutrient solutions to study the effects of Hemin on maize physiological and ecological mechanisms under cadmium stress. The results showed that Hemin mediated the increase of sucrose content and the activities of key enzymes sucrose phosphate synthase (SPS) and sucrose synthase (SS) in maize leaves under cadmium stress. Soluble acid invertase (SAInv) and basic/neutral invertase (A/N-Inv) enzyme activities in leaves were decreased significantly, and sucrose accumulation in leaves was increased. Hemin also mediated the increase of NO3- content in leaves, the decrease of NH4+ content and the increase of nitrate reductase (NR), glutamine synthetase (GS), glutamate synthase activity (GOGAT) and glutamate dehydrogenase (GDH) enzyme activities under cadmium stress. The contents of IAA, ZR, and GA in leaves and roots increased, ABA, MeJA, and SA decreased, and IAA/ABA, ZR/ABA, and GA/ABA increased under cadmium stress. Our study showed Hemin can alleviate cadmium stress in maize by enhancing sucrose and nitrogen metabolism and regulating endogenous hormones.

This work further investigates the effects of Hemin on the metabolism of sucrose and nitrogen and endogenous hormones in maize under cadmium stress, which, hopefully, is to guide Hemin application to maize field resilience production. It also explains that Hemin is beneficial for dry matter accumulation and transport, alleviated ammonia toxicity and nitrogen metabolism disorder, and induced the changes of endogenous hormone content and the adaptive hormone ratio balance under cadmium stress.

Effects of microplastics on nitrogen and phosphorus cycles and microbial communities in sediments.

Sediments are the long-term sinks of microplastics (MPs) and nutrients in freshwater ecosystems. Therefore, understanding the effect of MPs on sediment nutrients is crucial. However, few studies have discussed the effects of MPs on nitrogen and phosphorus cycles in freshwater sediments. Herein, 0.5% (w/w) polyvinyl chloride (PVC), polylactic acid (PLA), and polypropylene (PP) MPs were added to freshwater sediments to evaluate their effects on microbial communities and nitrogen and phosphorus release. The potential biochemical functions of the bacterial communities in the sediments were predicted and assessed via 16S rRNA gene sequencing. The results showed that MPs significantly affected the microbial community composition and nutrient cycling in the sediments. PVC and PP MPs can promote microbial nitrification and nitrite oxidation, while PP can significantly promote alkaline phosphatase (ALP) activity and the abundance of the phosphorus-regulation (phoR) gene. PLA MPs had the potential to promote the abundance of microbial phosphorus transporter (ugpB), nitrogen fixation (nifD, nifH, and nifX), and denitrification (nirS, napA, and norB) genes and inhibit nitrification, resulting in massive accumulation and release of ammonia nitrogen. Although PLA MPs inhibited the activity of ALP and the abundance of the organophosphorus mineralization (phoD) gene, it could enhance dissimilatory iron and sulfite reduction, which may promote the release of sedimentary phosphorus. Our findings may help understand the mechanisms of nitrogen and phosphorus cycles and microbial communities driven by MPs in sediments and provide a basis for future assessments of the environmental behavior of MPs in freshwater ecosystems.

Phosphate limitation intensifies negative effects of ocean acidification on globally important nitrogen fixing cyanobacterium.

Growth of the prominent nitrogen-fixing cyanobacterium Trichodesmium is often limited by phosphorus availability in the ocean. How nitrogen fixation by phosphorus-limited Trichodesmium may respond to ocean acidification remains poorly understood. Here, we use phosphate-limited chemostat experiments to show that acidification enhanced phosphorus demands and decreased phosphorus-specific nitrogen fixation rates in Trichodesmium. The increased phosphorus requirements were attributed primarily to elevated cellular polyphosphate contents, likely for maintaining cytosolic pH homeostasis in response to acidification. Alongside the accumulation of polyphosphate, decreased NADP(H):NAD(H) ratios and impaired chlorophyll synthesis and energy production were observed under acidified conditions. Consequently, the negative effects of acidification were amplified compared to those demonstrated previously under phosphorus sufficiency. Estimating the potential implications of this finding, using outputs from the Community Earth System Model, predicts that acidification and dissolved inorganic and organic phosphorus stress could synergistically cause an appreciable decrease in global Trichodesmium nitrogen fixation by 2100.

Design, Synthesis, and Biological Evaluation of Novel Dihydropyridine and Pyridine Analogs as Potent Human Tissue Nonspecific Alkaline Phosphatase Inhibitors with Anticancer Activity: ROS and DNA Damage-Induced Apoptosis.

Small molecules with nitrogen-containing scaffolds have gained much attention due to their biological importance in the development of new anticancer agents. The present paper reports the synthesis of a library of new dihydropyridine and pyridine analogs with diverse pharmacophores. All compounds were tested against the human tissue nonspecific alkaline phosphatase (h-TNAP) enzyme. Most of the compounds showed excellent enzyme inhibition against h-TNAP, having IC50 values ranging from 0.49 ± 0.025 to 8.8 ± 0.53 µM, which is multi-fold higher than that of the standard inhibitor (levamisole = 22.65 ± 1.60 µM) of the h-TNAP enzyme. Furthermore, an MTT assay was carried out to evaluate cytotoxicity against the HeLa and MCF-7 cancer cell lines. Among the analogs, the most potent dihydropyridine-based compound 4d was selected to investigate pro-apoptotic behavior. The further analysis demonstrated that compound 4d played a significant role in inducing apoptosis through multiple mechanisms, including overproduction of reactive oxygen species, mitochondrial dysfunction, DNA damaging, and arrest of the cell cycle at the G1 phase by inhibiting CDK4/6. The apoptosis-inducing effect of compound 4d was studied through staining agents, microscopic, and flow cytometry techniques. Detailed structure-activity relationship (SAR) and molecular docking studies were carried out to identify the core structural features responsible for inhibiting the enzymatic activity of the h-TNAP enzyme. Moreover, fluorescence emission studies corroborated the binding interaction of compound 4d with DNA through a fluorescence titration experiment.

Rosiglitazone Alleviates Contrast-Induced Acute Kidney Injury in Rats via the PPARγ/NLRP3 Signaling Pathway.

Background: This study investigated the effect and mechanism of rosiglitazone on a rat model with contrast-induced acute kidney injury (CI-AKI). Materials and Methods: The CI-AKI rat model was established from Sprague Dawley rats by furosemide injection (10 ml/kg) to the caudal vein followed by iohexol (11.7 ml/kg). The experimental grouping was randomly allocated into control, model, rosiglitazone, and T0070907 groups. Blood samples were collected from the abdominal aorta. Serum creatinine, urea nitrogen, MDA, and SOD contents were detected by biochemical analysis. TNF-α and IL-10 expression was detected by ELISA. Urine creatinine and urine protein were measured following 24-h urine biochemistry testing. Cell pathology and apoptosis were detected by H&E and TUNEL staining, respectively. PPARγ, NLRP3, eNOS, and caspase-3 mRNA expression were detected by qPCR. Caspase-3 and NLRP3 expression were detected by immunohistochemistry. Results: The CI-AKI rat model was successfully established because the results showed that compared with control, serum creatinine, urea nitrogen, MDA, SOD, TNF-α, and IL-10, urine creatinine and urine protein levels were significantly increased in the model group, indicating AKI, but was significantly decreased with rosiglitazone treatment, indicating recovery from injury, while opposite results were obtained with SOD. Apoptosis rate was significantly increased in the model group and significantly decreased with rosiglitazone treatment. NLRP3 and eNOS increased significantly in the model group and decreased significantly with rosiglitazone treatment, while opposite results were obtained with PPARγ. NLRP3 and caspase-3 protein expression was significantly increased in the model group and significantly decreased with rosiglitazone treatment. Conclusion: Rosiglitazone could alleviate acute renal injury in the CI-AKI rat model by regulating the PPARγ/NLRP3 signaling pathway and should be further investigated as a potential treatment in clinical studies.

Synthesis and anti-tumor activity of nitrogen-containing derivatives of the natural product diphyllin.

The natural product diphyllin has demonstrated great potential in the treatment of various human cancers, especially pancreatic cancer. However, its relative weak potency, low aqueous solubility, and poor metabolic stability limits its development ability. In this study, we designed and synthesized two series of novel nitrogen-containing diphyllin derivatives with the aim to improve both antitumor efficacy and drug-like properties. Among them, the amino derivative 15 showed an IC50 value of 3 nM against pancreatic cancer CFPAC-1 cells and is about 69-fold more potent than diphyllin. In addition, compound 15 possesses improved aqueous solubility and metabolic stability in liver microsomes. This compound not only significantly induced cell cycle arrest at G0/G1 phase with down-regulation of CDK4 and cyclinD1 in a dose-dependent manner, but also blocked the later stage of autophagy in CFPAC-1 cells. In pancreatic cancer xenograft model, treatment of 15 with 10 mg/kg exhibited much more potent efficacy in suppressing the growth of transplanted PANC02 tumors than diphyllin without obvious safety concern.

Effects of cysteamine supplementation on cryopreserved buffalo bull semen quality parameters.

This work aimed to determine the effect of cysteamine (25, 50, 100 and 200 µM) incorporated during dilution on frozen thawed buffalo semen quality. Semen was collected twice weekly for 7 consecutive weeks from three Egyptian buffalo bulls using an artificial vagina. Semen samples were pooled and extended with a Tris-based extender, cooled, equilibrated and finally frozen in liquid nitrogen. The diluted semen was evaluated for motility, viability, morphology, plasma membrane and DNA integrity, in addition to oxidative stress and in vitro fertilizing capability. The post thaw motility and velocity parameters noticeably increased with different concentrations of cysteamine (mainly 100 µM) during different incubation periods. The post thaw sperm viability and normality significantly (p < 0.05) improved with concentrations of 50 and 100 µM. Plasma membrane integrity substantially increased at all concentrations of cysteamine. Cysteamine reduced alanine aminotransferase (at all concentrations), aspartate aminotransferase (at 25-100 µM), and creatine kinase (at 100 and 200 µM). Cysteamine at a concentration of 100 µM noticeably enhanced the total antioxidant capacity and glutathione peroxidase and decreased nitric oxide production. Cysteamine, at concentrations of 100 and 200 µM, increased the DNA intensity in the comet head (%) and decreased the DNA % in the comet tail. The comet tail length and moment substantially decreased at concentrations of 50-200 µM. Cysteamine did not affect the in vitro fertilizing capability of sperm. In conclusion, cysteamine incorporation (mainly at a concentration of 100 µM) in buffalo semen extender showed varying protective effects on different sperm parameters against cryo-damage; however, it did not affect the in vitro fertilizing capacity of sperm.

Thymoquinone improves motility, plasma membrane integrity and DNA integrity of frozen-thawed ram semen.

The aim of this study was to determine the effects of thymoquinone (TQ), which is the most essential active compound of Nigella sativa, on the spermatological parameters of ram semen during cryopreservation. Ejaculates were collected from five Sonmez rams using an artificial vagina and extended with Tris-based extender not containing TQ (control, 0 µg/ml TQ) and containing 10, 25, 50 and 100 µg/ml TQ. The extended semen samples were equilibrated in a + 4°C cold cabinet for 2 h. After 2 h, the samples were loaded into 0.25 ml French straws. The straws were frozen by liquid nitrogen vapour and stored in a liquid nitrogen container (-196°C). The frozen straws were thawed in a water bath (37°C for 30 s) and evaluated in terms of motility characteristics, plasma membrane and acrosome integrity, mitochondrial reactive oxygen species levels, lipid peroxidation levels, DNA damage and biochemical alterations (oxidative stress index, malondialdehyde and glutathione). TQ100 had higher total motility (53.59 ± 3.01) and progressive motility (19.84 ± 1.44; not significantly different from TQ25 and TQ50) compared to the control and TQ10 (p Ë‚ 0.05). According to the results of the analyses on motility characteristics, there were significant differences between the groups in terms of curvilinear velocity (VCL), amplitude of lateral head displacement (ALH) and linearity (LIN; p Ë‚ 0.05). The highest DNA damage was detected in the control group (p Ë‚ 0.05). TQ50 had higher plasma membrane and acrosome integrity (59.56 ± 5.92) compared to the control and TQ25 (p < 0.05) but not significantly different from TQ10 and TQ100. The lowest mitochondrial reactive oxygen species levels were detected in TQ50 and TQ100 (p Ë‚ 0.05). There were no significant differences among the groups in terms of their oxidative stress index, lipid peroxidation, malondialdehyde and glutathione levels (p > 0.05). According to the results, it could be concluded that supplementing 50 or 100 µg/ml TQ to Tris extenders that were used for ram semen cryopreservation showed a positive effect on motility, plasma membrane integrity and acrosome integrity, and it reduced DNA damage and mitochondrial reactive oxygen species levels.

Effect of Astragalus polysaccharides on the cryopreservation of goat semen.

During cryopreservation, sperm encounters oxidative stress induced by excessive reactive oxygen species (ROS), destroying the sperm plasma membrane structure and reducing its physiological functions. The present study aimed to evaluate the effect of Astragalus polysaccharides (APS) on the cryopreservation of dairy goat semen. Semen was collected from six goats, and then qualified semen with movement >80% was selected after preliminary evaluation. The semen was divided into six aliquots, diluted with dairy goat semen extender (1:10) at 37 °C, containing 0 g/L (control), 0.1 g/L, 0.2 g/L, 0.3 g/L, 0.4 g/L and 0.5 g/L APS, cryopreserved, and stored in liquid nitrogen (-196 °C). Sperm quality was assessed after freeze-thawing. The highest sperm motility, motion performance, plasma membrane integrity, acrosome integrity, and antioxidant properties (total antioxidant capacity and levels of antioxidant enzymes) were recorded (P < 0.05) in the 0.2 g/L APS group after the semen was freeze-thawed. The control and the optimal group (0.2 g/L) were then selected to analyze the effects of APS on sperm energy metabolism (mitochondrial membrane potential [MMP] and adenosine triphosphate [ATP]), sperm apoptosis, and the expression of the AMPK signaling pathway. The results showed that treatment with 0.2 g/L APS increased sperm MMP and ATP content after freeze-thawing, reduced sperm apoptosis by regulating apoptosis-related proteins, and promoted AMPK phosphorylation by activating the AMPK signaling pathway. The cleavage rate of frozen goat sperm during in vitro fertilization (IVF) was also observed to increase. These findings suggest meaningful ways to improve cryopreservation of dairy goat semen and provide new insights into the mechanism by which APS protects sperm from oxidative damage via AMPK activation.