Nanoscale Modification of Titanium Implants Improves Behaviors of Bone Mesenchymal Stem Cells and Osteogenesis In Vivo

The surficial micro/nanotopography and physiochemical properties of titanium implants are essential for osteogenesis. However, these surface characters’ influence on stem cell behaviors and osteogenesis is still not fully understood. In this study, titanium implants with different surface roughness, nanostructure, and wettability were fabricated by further nanoscale modification of sandblasted and acid-etched titanium (SLA: sandblasted and acid-etched) by H2O2 treatment (hSLAs: H2O2 treated SLA). The rat bone mesenchymal stem cells (rBMSCs: rat bone mesenchymal stem cells) are cultured on SLA and hSLA surfaces, and the cell behaviors of attachment, spreading, proliferation, and osteogenic differentiation are further analyzed. Measurements of surface characteristics show hSLA surface is equipped with nanoscale pores on microcavities and appeared to be hydrophilic. In vitro cell studies demonstrated that the hSLA titanium significantly enhances cell response to attachment, spreading, and proliferation. The hSLAs with proper degree of H2O2 etching (h1SLA: treating SLA with H2O2 for 1 hour) harvest the best improvement of differentiation of rBMSCs. Finally, the osteogenesis in beagle dogs was tested, and the h1SLA implants perform much better bone formation than SLA implants. These results indicate that the nanoscale modification of SLA titanium surface endowing nanostructures, roughness, and wettability could significantly improve the behaviors of bone mesenchymal stem cells and osteogenesis on the scaffold surface. These nanoscale modified SLA titanium scaffolds, fabricated in our study with enhanced cell affinity and osteogenesis, had great potential for implant dentistry.

Mineral-associated soil organic matter: characteristics and behavior under diagenesis

The main part of soil organic matter (OM) is mineral-associated: 88 ± 11% of С and even more – 93 ± 9% of N. The aims of the given study were: 1 – to demonstrate experimentally the adsorption selectivity of organic compounds towards minerals with different physico-chemical properties (palygorskite vs montmorillonite); 2 – to characterize mineral-associated OM of buried Late Holocene palaeosols and estimate its diagenetic transformations; 3 – to investigate the OM of humin from modern soils of different genesis and Pleistocene and Holocene palaeosols and estimate its diagenetic transformations. The basic soil properties were determined using standard methods. Clay fractions (<2 um) – natural organo-mineral complexes (OMC) were obtained by sedimentation, their mineralogy was studied by XRD. The elemental composition of OM was studied with CNS-analyzer. The structural characteristics of organic matter were determined with the solid-state 13C-NMR-spectroscopy and FTIR-spectroscopy, isotopic composition of C and N – by mass-spectrometry. The obtained results show that the characteristics of mineral-associated OM depends on the properties of mineral “filter” as well as the fate of OM under diagenesis: how long, in what quantity and quality it will persist. It was shown that palygorskite adsorbed predominantly O-alkyls, which are chemically strongly bound. As a result, the age of fulvic type humus in palygoskite palaeosols can reach 300 My. From other side humus of smectitic paleosols of the same age is present by deeply transformed aromatic structures (“coal”). Mineral-associated OM of buried under kurgans Holocene palaeosols contains more alkyls and carboxylic groups, is less aromatic in a comparison with OM of the respective soils. The specific feature of mineral-associated OM is its enrichment in N-compounds. The later are present by both vegetal and microbial compounds, and demonstrate the large affinity towards the mineral surfaces. The formation of chemical bounds between them provides the persistence of OM in OMC. E.g. H2O2 treatment results in preferential destruction of C-rich compounds and oxidized OM demonstrates larger C/N values. Mineral-associated OM of buried Holocene soils keeps the decreased values of C/N (7–14 vs 14–21 for OM of whole soils). Additionally they are characterized by heavier isotopic composition of δ15N in a comparison with the respective soils (5–11‰ vs 6–9‰). It could be explained either by the accumulation of microbial N, or increasing of the humification degree – the loss of aliphatic C and increasing of aromaticity. Humin is the considerable part of soil humus. Experimentally shown that OM of humins both of soils and OMC is enriched in O-alkyls and C of acetal groups. OM of humins are not homogeneous, and consists from at least two groups: mineral-associated OM and partly mineralized plant fragments. As a consequence, the content of humin in OMC is smaller in a comparison with respective soils. It is concluded that mineral-associated OM and humin as well as soil humus represent dynamic soil systems.

In Vitro and In Vivo Protective Effects of Lentil (Lens culinaris) Extract against Oxidative Stress-Induced Hepatotoxicity

Excessive oxidative stress plays a role in hepatotoxicity and the pathogenesis of hepatic diseases. In our previous study, the phenolic extract of beluga lentil (BLE) showed the most potent in vitro antioxidant activity among extracts of four common varieties of lentils; thus, we hypothesized that BLE might protect liver cells against oxidative stress-induced cytotoxicity. BLE was evaluated for its protective effects against oxidative stress-induced hepatotoxicity in AML12 mouse hepatocytes and BALB/c mice. H2O2 treatment caused a marked decrease in cell viability; however, pretreatment with BLE (25–100 μg/mL) for 24 h significantly preserved the viability of H2O2-treated cells up to about 50% at 100 μg/mL. As expected, BLE dramatically reduced intracellular reactive oxygen species (ROS) levels in a dose-dependent manner in H2O2-treated cells. Further mechanistic studies demonstrated that BLE reduced cellular ROS levels, partly by increasing expression of antioxidant genes. Furthermore, pretreatment with BLE (400 mg/kg) for 2 weeks significantly reduced serum levels of alanine transaminase and triglyceride by about 49% and 40%, respectively, and increased the expression and activity of glutathione peroxidase in CCl4-treated BALB/c mice. These results suggest that BLE protects liver cells against oxidative stress, partly by inducing cellular antioxidant system; thus, it represents a potential source of nutraceuticals with hepatoprotective effects.

The Protective Effects of Carrageenan Oligosaccharides on Intestinal Oxidative Stress Damage of Female Drosophila melanogaster

Carrageenan oligosaccharides (COS) have been reported to possess excellent antioxidant activities, but the underlying mechanism remains poorly understood. In this study, H2O2 was applied to trigger oxidative stress. The results showed that the addition of COS could effectively extend the lifespan of female Drosophila, which was associated with improvements by COS on the antioxidant defense system, including a decrease in MDA, the enhanced activities of SOD and CAT, the reduction of ROS in intestinal epithelial cells, and the up-regulation of antioxidant-relevant genes (GCL, GSTs, Nrf2, SOD). Meanwhile, the axenic female Drosophila fed with COS showed almost no improvement in the above measurements after H2O2 treatment, which highlighted the antioxidant mechanism of COS was closely related to intestinal microorganisms. Then, 16S rDNA high-throughput sequencing was applied and the result showed that the addition of COS in diets contributed to the diversity and abundance of intestinal flora in H2O2 induced female Drosophila. Moreover, COS significantly inhibited the expression of gene mTOR, elevated its downstream gene 4E-BP, and further inhibited autophagy-relevant genes (AMPKα, Atg1, Atg5, Atg8a) in H2O2 induced female Drosophila. The inhibition of the mTOR pathway and the activation of autophagy was probably mediated by the antioxidant effects of COS. These results provide potential evidence for further understanding of COS as an intestinal antioxidant.

Oxyfertigation and Transplanting Conditions of Strawberries

Soilless growing systems can improve water-use efficiency, especially in closed soilless growing systems. The main purpose of this study was to evaluate the effects of different transplanting conditions, and determine how supplying H2O2 as an oxygen source to the rhizosphere of strawberry plants in a soilless growing system affects plant growth, fruit yield and fruit quality. Strawberry plants (Fragaria x ananassa Duch.) cv. ‘Fortuna’ were cultivated in 12 L pots filled with peat substrate, and maintained under conditions of natural light and temperature. Treated plants were supplied with hydrogen peroxide (H2O2) (H1) and control plants did not receive H2O2 (H0). In terms of the transplanting conditions, the plants were transplanted in October (T1), and either maintained in a culture chamber (T2), or refrigerated (T3), for one month, before being transplanted. A completely randomized block design with two treatment factors (transplanting conditions, and H2O2 treatment) and five replications was established. Then, we determined the fruit per plant, yield per plant (g plant−1), fruit weight (g fruit−1), fruit size (mm), SPAD values, crown number, crown diameter (mm), flower number, firmness (g cm−1), pH, total soluble solid (TSS), titratable acidity (TA) and TSS/TA. During the early crop cycle, there were not significant differences between treatment and the transplanting conditions that significantly affected the fruit weight and fruit size, although T3 produced the highest values. During the late crop cycle, the H2O2 treatment affected fruit per plant, yield per plant (g plant−1), and crown diameter, with H1 producing the highest values. Furthermore, the transplanting conditions affected yield per plant (g plant−1), old SPAD values, crown diameter, firmness, TSS, TA and TSS/TA.

Monovalent Ions and Stress-Induced Senescence in Human Mesenchymal Endometrial Stem Cells

Monovalent ions are involved in growth, proliferation, differentiation of cells as well as in their death. This work concerns the ion homeostasis during senescence induction in human mesenchymal endometrium stem cells (hMESC): hMESCs subjected to oxidative stress (pulse H2O2 treatment) enter the premature senescence accompanied by persistent DNA damage, irreversible cell cycle arrest, cell hypertrophy, lipofuscin accumulation, enhanced β-galactosidase activity. Using flame photometry to estimate K+, Na+ content and Rb+ (K+) fluxes we found that during the senescence development in stress-induced hMESCs, Na+/K+pump-mediated K+ fluxes are enhanced due to the increased Na+ content in senescent cells, while ouabain-resistant K+ fluxes remain unchanged. Senescence progression is accompanied by a peculiar decrease in the K+ content in cells from 800-900 µmol/g to 500-600 µmol/g. Since cardiac glycosides are offered as selective agents for eliminating senescent cells, we investigated the effect of ouabain on ion homeostasis and viability of hMESCs and found that in both proliferating and senescent hMESCs, ouabain (1 nM-1 µM, 24-48 h) inhibited pump-mediated K+ transport (ID50 5x10-8 M), decreased cell K+/Na+ ratio to 0,1-0,2, however did not induce apoptosis. Comparison of the effect of ouabain on hMESCs with the literature data on the selective cytotoxic effect of cardiac glycosides on senescent or cancer cells suggests the ion pump blockade and intracellular K+ depletion should be synergized with target apoptotic signal to induce the cell death.

Ferulic Acid Alleviates Oxidative Stress-Induced Cardiomyocyte Injury by the Regulation of miR-499-5p/p21 Signal Cascade

Objective. To investigate the protective effects and regulatory mechanisms of ferulic acid on oxidative stress-induced cardiomyocyte injury. Methods. We established a cardiomyocyte oxidative stress cell model by H2O2 treatment and a mouse heart injury model by isoprenaline infusion of male C57BL/6 mice. Ferulic acid was applied to treat oxidative stress-induced cardiomyocyte injury. DHE staining was used to detect ROS production. DNA fragmentation, TUNEL assay, and cleaved caspase-3 were used to analyze cell apoptosis. Real-time PCR and Western blotting were used to analyze miRNA and protein levels to investigate the regulatory mechanisms of ferulic acid on oxidative stress-induced cardiomyocyte injury. Results. Ferulic acid pretreatment significantly inhibited H2O2- and isoprenaline-induced oxidative stress and cell apoptosis by promoting miR-499-5p expression and inhibiting p21 expression. MiR-499-5p inhibition reversed the protective effects of ferulic acid. Further study found that ferulic acid could also attenuate isoprenaline-induced mouse heart fibrosis and cell apoptosis by reducing oxidative stress, inflammation, and apoptosis in vivo. Conclusions. We proved that ferulic acid protects cardiomyocytes from oxidative stress-induced injury by regulating the miR-499-5p/p21signaling pathway, which provides insight into the clinical application of ferulic acid in the treatment of cardiovascular diseases.

Preparation of a Highly Porous Clay-Based Absorbent for Hazard Spillage Mitigation via Two-Step Expansion of Vermiculite

Expanded vermiculite (eVMT) has been studied as a risk-free, general-purpose absorbent for liquid hazards due to its excellent thermal and chemical stability. Here, vermiculite was expanded by two steps: exfoliation by 30 wt% H2O2 treatment at 60 °C and subsequent expansion by microwave heating. This two-step expansion produced more homogenously separated concertina-like eVMTs with a higher total pore volume of 7.75 cm3 g−1 than the conventional thermal method. The two-step eVMT was found to be greatly superior to the thermal and commercial silver counterparts in hazardous liquid-uptake performance. The uptake was simply interpreted as a physical infilling process of a liquid into the eVMT pores, and the spontaneous hazard removal with a great capacity was discussed with the large pore volume of two-step eVMT and its suitable pore dimensions for capillary action. As a practical device, a prototype absorbent assembly made of these eVMTs demonstrated the successful mitigation of liquid hazards on an impermeable surface.

Depletion of the miR-34a “sponge” MALAT1 in aging skeletal muscle: Implications for age-related muscle loss

We have recently shown that increased levels of reactive oxygen species (ROS) in aging skeletal muscle are associated with increased expression of the senescence-associated microRNA miR-34a-5p (miR-34a). The histone deacetylase Sirt1 is a validated target of miR-34a, and miR-34a expression is induced by the tumor suppressor p53 which is itself stimulated by ROS. Long noncoding RNAs (lncRNAs) are known to function as “sponges” for microRNAs, but the role of such competing endogenous RNAs (ceRNA) in muscle aging is not well understood. We therefore examined in skeletal muscles of young (4-6 mos) and aged (22-24) male and female mice the expression of several lncRNAs that are predicted to bind miR-34a-5p in silico and whose predicted binding has been validated experimentally. Results indicate a significant decrease in lncRNA MALAT1 expression with aging. MALAT1 is known to be highly expressed during the later stages of myoblast differentiation and myotube maturation. We therefore treated C2C12 cells at 48 hrs with hydrogen peroxide (10 uM) and examined changes in MALAT1 expression. MALAT1 was significantly decreased with H2O2 treatment, whereas miR-34a is increased in C2C12 cells after hydrogen peroxide exposure. Age-related muscle atrophy mediated by ROS may therefore result in part from related mechanisms involving miR-34a activity: an increase in miR-34a targeting Sirt1 resulting from p53 activation and an increase in miR-34a bioavailability resulting from a decline in miR-34a “sponging” due to ceRNA MALAT1 depletion. These findings suggest that therapeutic interventions increasing MALAT1 expression in muscle may potentially enhance the preservation of muscle mass with aging.