Effects of Gestational Arsenic Exposures on Placental and Fetal Development in Mice: The Role of Cyr61 m6A.

BACKGROUND: Several epidemiological investigations demonstrated that maternal arsenic (As) exposure elevated risk of fetal growth restriction (FGR), but the mechanism remains unclear. OBJECTIVES: This study aimed to investigate the effects of gestational As exposure on placental and fetal development and its underlying mechanism. METHODS: Dams were exposed to 0.15, 1.5, and 15mg/L NaAsO2 throughout pregnancy via drinking water. Sizes of fetuses and placentas, placental histopathology, and glycogen content were measured. Placental RNA sequencing was conducted. Human trophoblasts were exposed to NaAsO2 (2µM) to establish an in vitro model of As exposure. The mRNA stability and protein level of genes identified through RNA sequencing were measured. N6-Methyladenosine (m6A) modification was detected by methylated RNA immunoprecipitation-quantitative real-time polymerase chain reason (qPCR). The binding ability of insulin-like growth factor 2 binding protein 2 to the gene of interest was detected by RNA-binding protein immunoprecipitation-qPCR. Intracellular S-adenosylmethionine (SAM) and methyltransferase activity were determined by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and colorimetry, respectively. In vitro As+3 methyltransferase (As3MT) knockdown or SAM supplementation and in vivo folic acid (FA) supplementation were used to evaluate the protective effect. A case-control study verified the findings. RESULTS: Sizes of fetuses (exposed to 1.5 and 15mg/L NaAsO2) and placentas (exposed to 15mg/L NaAsO2) were lower in As-exposed mice. More glycogen+ trophoblasts accumulated and the expression of markers of interstitial invasion was lower in the 15mg/L NaAsO2-exposed mouse group in comparison with control. Placental RNA sequencing identified cysteine-rich angiogenic inducer 61 (Cyr61) as a candidate gene of interest. Mechanistically, mice and cells exposed to As had lower protein expression of CYR61, and this was attributed to a lower incidence of Cyr61 m6A. Furthermore, cells exposed to As had lower methyltransferase activity, suggesting that this could be the mechanism by which Cyr61 m6A was affected. Depletion of intracellular SAM, a cofactor for m6A methyltransferase catalytic domain, partially contributed to As-induced methyltransferase activity reduction. Either As3MT knockdown or SAM supplementation attenuated As-induced Cyr61 m6A down-regulation. In mice, FA supplementation rescued As-induced defective trophoblastic invasion and FGR. In humans, a negative correlation between maternal urinary As and plasma CYR61 was observed in infants who were small for gestational age. DISCUSSION: Using in vitro and in vivo models, we found that intracellular SAM depletion-mediated Cyr61 m6A down-regulation partially contributed to As-induced defective trophoblastic invasion and FGR. https://doi.org/10.1289/EHP12207.

Developmental toxicity of perfluorohexane sulfonate at human relevant dose during pregnancy via disruption in placental lipid homeostasis.

Perfluorohexyl sulfonate (PFHxS) is the third most abundant per- and polyfluoroalkyl substances and its developmental toxicity remains very poorly understood. Here, pregnant mice exposed to PFHxS at human relevant dose showed increased fetal death incidence in the high-dose PFHxS-H group (P < 0.01). Body distribution analyses suggested that PFHxS crossed the placental barrier reaching the fetus in a dose-dependent manner. Histopathological data demonstrated impairment in the placenta with reduced blood sinus volume, placental labyrinth area as well as thickness of labyrinthine layer. Further lipidomic and transcriptomic data together showed that PFHxS exposure caused significant disruption in placental lipid homeostasis, including total lipid accumulation in the placenta, and dysregulation in phospholipid and glycerol lipid metabolism. Gene expression analyses uncovered elevation in key placental fatty acid transporters including fabp2, whereas protein expression showed transporter specific disruptions following exposure. Together, gestational exposure to human relevant level of PFHxS may increase the incidence of fetal deaths and caused placental dysplasia via disruption in lipid metabolism homeostasis. These findings raise the concern regarding the highly prevalent and persistent chemical towards early sensitive developing stages and provide basis for further understanding of its effects on lipid metabolism and underlying mechanisms.

Transcriptional and Physiological Analysis Reveal New Insights into the Regulation of Fertilization (N, P, K) on the Growth and Synthesis of Medicinal Components of Dendrobium denneanum.

Dendrobium denneanum is an important medicinal and ornamental plant. Its ornamental and medicinal values are affected by its vegetative growth conditions and chemical composition accumulation. This study adopted an orthogonal experimental design to treat D. denneanum with nine different levels of nitrogen (N), potassium (K), and phosphorus (P). The morphological indicators of the plant were positively correlated with the nitrogen concentration. The polysaccharide content was the highest at 1500 mg·L-1 nitrogen and 3000 mg·L-1 phosphorous and was 26.84% greater than the control. The flavonoid content increased by 36.2% at 500 mg·L-1 nitrogen, 2000 mg·L-1 phosphorous, and 300 mg·L-1 potassium. Principal component score analysis showed that nitrogen had the most significant impact on the various indicators of D. denneanum, followed by phosphorus and potassium. The comprehensive score showed that the T9 treatment (N: 1500 mg·L-1, P: 3000 mg·L-1, K: 500 mg·L-1) had the strongest effect on D. denneanum. Transcriptional analysis showed that compared with the control, the T9 treatment led to 2277 differentially expressed genes (1230 upregulated and 1047 downregulated). This includes fifteen genes enriched in the MAPK signaling pathway, five genes in phenylpropanoid biosynthesis, and two genes in flavonoid biosynthesis. These genes may be involved in regulating plant growth and the biosynthesis of polysaccharides and flavonoids. This study provides guidance for the optimal use of N, P, and K in the cultivation of D. denneanum.

Cerium improves the physiology and medicinal components of Dendrobium nobile Lindl. under copper stress.

Heavy metal stress affects the quality of medicinal plants, and rare earth elements can effectively alleviate heavy metal stress. In this paper, we investigated the effects of rare earth element cerium (0, 5, 10, 20, 40, 80, and 160 mg/L) on the physiological and medicinal components of Dendrobium nobile Lindl. under copper (200 mg/L) stress. The results revealed that cerium (Ce) had a good alleviating effect on copper (Cu) stress, low concentrations of Ce (10-20 mg/L) significantly improved the resistance and medicinal qualities of the plant such as polysaccharide, polyphenol and flavonoid, it also increased the content of photosynthetic pigment, proline, soluble sugar and soluble protein of D. nobile Lindl., effectively balance the osmotic pressure and the generation and removal of reactive oxygen species in the plant, thereby the toxic effect of copper on D. nobile Lindl. is alleviated. From the point of view of the treatment time when the optimal relieving concentration appeared, the optimal concentration for relieving antioxidant enzyme activity all appeared at the treatment time of 10 d, the optimum concentrations of other indicators all appeared at the treatment time of 15 d. Overall, this study suggests that the optimum level of Ce (10-20 mg/L) might be promising for alleviating the adverse impacts of copper stress and promoting the accumulation of medicinal components in D. nobile Lindl.

Characterization and antihyperglycemic activity of a polysaccharide from Dioscorea opposita Thunb roots.

A polysaccharide DOTP-80 from Dioscorea opposita Thunb was obtained by using the method of acid water-extraction and ethanol-precipitation. After being purified by chromatography, the structure characteristics of DOTP-80 were established. Based on the calibration curve obtained with standard dextrans, the molecular weight of the polysaccharide fraction DOTP-80 was calculated to be 123 kDa. The results of Infrared spectrum (FT-IR) indicated that the polysaccharide contained the α-configuration of sugar units. GC-MS analysis revealed that DOTP-80 was mainly composed of mannose and glucose. Alloxan-induced diabetic rats and mice models were developed to evaluate the in vivo hypoglycemic activity of the polysaccharide. The results indicated that a high dose DOTP-80 (400 mg/kg) had strong hypoglycemic activity. Moreover, DOTP-80 could increase the level of antioxidant enzymes (SOD) activity in alloxan-induced diabetic mice and stimulate an increase in glucose disposal in diabetic rats. Therefore, the polysaccharide DOTP-80 should be evaluated as a candidate for future studies on diabetes mellitus.

[Correlation Between Functional Groups and Radical Scavenging Activities of Acidic Polysaccharides from Dendrobium].

OBJECTIVE: To compare the radical scavenging activity of five different acidic polysaccharides, and to find the correlation with the functional groups. METHODS: Alkali extraction method and Stepwise ethanol precipitation method were used to extract and concentrate the five Dendrobium polysaccharides, and to determine the contents of sulfuric acid and uronic acid of each kind of acidic polysaccharides, and the scavenging activity to ABTS+ radical and hydroxyl radical. Functional group structures were examined by FTIR Spectrometer. RESULTS: Five kinds of Dendrobium polysaccharides had different ability of scavenging ABTS+ free radical and hydroxyl free radical. Moreover, the study had shown that five kinds of antioxidant activity of acidic polysaccharides had obvious correlation withuronic acid and sulfuric acid. The antioxidant activity of each sample was positively correlated with the content of uronic acid, and negatively correlated with the content of sulfuric acid. CONCLUSION: Sulfuric acid can inhibit the antioxidant activity of acidic polysaccharide but uronic acid can enhance the free radical scavenging activity. By analyzing the structure characteristics of five acidic polysaccharides, all samples have similar structures, however, Dendrobium denneanum, Dendrobium devonianum and Dendrobium officinale which had ß configuration have higher antioxidant activity than Dendrobium nobile and Dendrobium fimbriatum which had a configuration.

Characterization and antitumor activity of a polysaccharide from Sarcodia ceylonensis.

A water-soluble polysaccharide from Sarcodia ceylonensis was obtained by using the method of water-extraction and ethanol-precipitation. The polysaccharide was further purified by chromatography on AB-8 and ADS-7 columns, yielding a pure polysaccharide termed SCP-60. The molecular weight (Mw) of SCP-60 was calculated to be 50.0 kDa, based on the calibration curve obtained with a series of Dextran T standards. The results of FT-IR indicated that the polysaccharide contains the α-configuration of sugar units. GC-MS analysis revealed that SCP-60 was mainly composed of galactose and glucose. NMR spectroscopy revealed SCP-60 had the backbone consisting of → 6)-α-Manp-(1 →, α-D-Glcp-(1 →, → 6)-α-D-Glcp-(1 → and → 6)-α-Galp-(1 →. In order to evaluate the antitumor activity in vivo of the polysaccharide, a sarcoma 180 model was used. The results showed SCP-60 had strong antitumor ability, meanwhile, SCP-60 at a high dose (100 mg/kg) could significantly increase the thymic and splenic indices of S180 mice, and strongly promote the secretion of IL-2, TNF-α and IFN-γ, increase the SOD activities and reduce the concentrations of MDA in blood. Therefore the polysaccharide SCP-60 should be explored as a novel potential antitumor drug.

Juvenile cannabinoid treatment induces frontostriatal gliogenesis in Lewis rats.

Cannabis abuse in adolescence is associated with a broad array of phenotypical consequences, including a higher risk for schizophrenia and other mental disturbances related to dopamine (DA) imbalances. The great variability of these sequelae likely depends on the key influence of diverse genetic vulnerability factors. Inbred rodent strains afford a highly informative tool to study the contribution of genetic determinants to the long-term effects of juvenile cannabinoid exposure. In this study, we analyzed the phenotypical impact of the synthetic cannabinoid agonist WIN 55,212-2 (WIN; 2mg/kg/day from postnatal day 35-48) in adolescent Lewis rats, an inbred strain exhibiting resistance to psychotomimetic effects of environmental manipulations. At the end of this treatment, WIN-injected animals displayed increased survival of new cells (mainly oligodendroglia precursors) in the striatum and prefrontal cortex (PFC), two key terminal fields of DAergic pathways. To test whether these changes may be associated with enduring behavioral alterations, we examined the consequences of adolescent WIN treatment in adulthood (postnatal days 60-70), with respect to DA levels and metabolism as well as multiple behavioral paradigms. Rats injected with WIN exhibited increased turnover, but not levels, of striatal DA. In addition, cannabinoid-treated animals displayed increases in acoustic startle latency and novel-object exploration; however, WIN treatment failed to induce overt deficits of sensorimotor gating and social interaction. These results indicate that, in Lewis rats, juvenile cannabinoid exposure leads to alterations in frontostriatal gliogenesis, as well as select behavioral alterations time-locked to high DAergic metabolism, but not overt schizophrenia-related deficits.

In vitro and in vivo antioxidant activity of a water-soluble polysaccharide from Dendrobium denneanum.

The water-soluble crude polysaccharide (DDP) obtained from the aqueous extracts of the stem of Dendrobium denneanum through hot water extraction followed by ethanol precipitation, was found to have an average molecular weight (Mw) of about 484.7 kDa. Monosaccharide analysis revealed that DDP was composed of arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.66:8.92:34.20:10.16. The investigation of antioxidant activity both in vitro and in vivo showed that DDP is a potential antioxidant.

In vitro antioxidant activities of a water-soluble polysaccharide derived from Dendrobium nobile Lindl. extracts.

A water-soluble polysaccharide (DNP), isolated from the aqueous extracts of the stem of Dendrobium nobile Lindl., was found to have an average molecular weight (Mw) of about 8.76 x 10(4)Da. Monosaccharides analysis revealed that DNP was composed of rhamnose, arabinose, xylose, mannose, glucose and galactose in a molar ratio of 1.00:2.80:2.20:30.76:117.96:31.76. The evaluation of antioxidant activity in vitro revealed that DNP is a novel potential antioxidant. The NMR spectra suggested that the main structure of DNP was possible as the predicted main structure of DNP from Dendrobium nobile, (fig. 5).

[Research progress of the drug screening technology in type 2 diabetes mellitus].

With the incidence of type 2 diabetes mellitus increasing year after year, the technology of drug screening of type 2 diabetes mellitus progress rapidly, from the level of animal screening to cellular and molecular screening model, from the traditional drug screening technology to high efficient and throughput screening. This paper will summarize the technology of drug screening in the therapy of type 2 diabetes mellitus.