Long non-coding RNA X-Inactive Specific Transcript (XIST) interacting with USF2 promotes osteogenic differentiation of periodontal ligament stem cells through regulation of WDR72 transcription.

BACKGROUND: Periodontal ligament stem cells (PDLSCs) are the most potential cells in periodontal tissue regeneration and bone tissue regeneration. Our prior work had revealed that WD repeat-containing protein 72 (WDR72) was crucial for osteogenic differentiation of PDLSCs. Here, we further elucidated its underlying mechanism in PDLSC osteogenic differentiation. METHODS: Human PDLSCs, isolated and identified by flow cytometry, were prepared for osteogenic differentiation induction. Levels of WDR72, long non-coding RNA X-Inactive Specific Transcript (XIST), upstream stimulatory factor 2 (USF2), and osteogenic marker genes (Runx2, Osteocalcin, and Collagen I) in human PDLSCs and clinical specimens were detected by RT-qPCR. Protein expressions of WDR72, Runx2, Osteocalcin, and Colla1 were tested by Western blot. The interactions among the molecules were verified by RIP, RNA pull-down, ChIP, and luciferase reporter assays. Osteogenic differentiation was evaluated by alkaline phosphatase (ALP) and alizarin red staining (ARS). RESULTS: WDR72 was decreased in periodontal tissues of periodontitis patients, and overexpression reversed TNF-α-mediated suppressive effects on PDLSC osteogenic differentiation. Mechanically, XIST recruited the enrichment of USF2 to the WDR72 promoter region, thereby positively regulating WDR72. WDR72 silencing overturned XIST-mediated biological effects in PDLSCs. CONCLUSION: WDR72, regulated by the XIST/USF2 axis, enhances osteogenic differentiation of PDLSCs, implying a novel strategy for alleviating periodontitis.

Ghrelin attenuate cerebral microvascular leakage by regulating inflammation and apoptosis potentially via a p38 MAPK-JNK dependent pathway.

Ghrelin is a peptide hormone with strong anti-inflammatory properties. In fact, Ghrelin was reported to improve endothelial dysfunction caused by excessive fat. However, its role in preserving the integrity of brain microvascular, under conditions of lipid dysregulation and inflammation, is not known. The objective of this study is to characterize the role of Ghrelin in the protection of cerebral microvascular integrity, during atherosclerosis, and uncover its underlying molecular mechanism. Our results demonstrated that an atherosclerotic condition, brought on by a high fat diet (HFD), can produce massive increases in serum inflammatory factors, blood lipids, cerebral microvascular leakage, and activation of the p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) (p38 MAPK-JNK) pathway. It also produced significantly damaged pericytes morphology, resulting in pericyte decrease. Ghrelin treatment, on the other hand, protected against cerebral microvascular leakage and pericytes damage. Ghrelin effectively downregulated the expression of pro-inflammatory cytokines, and it also suppressed the p38 MAPK-JNK signaling pathway. Additionally, in isolated mouse cerebral microvascular pericytes, ox-LDL lead to increased apoptosis and secretion of inflammatory factors, along with an elevation in phosphorylated p38 MAPK-JNK proteins. Alternately, Ghrelin administration markedly lowered expression of inflammatory factors, suppressed the p38 MAPK-JNK signaling path, and halted cell apoptosis. However, pretreatment of Hesperetin, a p38 MAPK-JNK agonist, abrogated the Ghrelin-mediated suppression of inflammation and apoptosis in pericytes. Taken together, these results suggest that Ghrelin restored cerebral microvascular integrity and reduced vascular leakage in atherosclerosis mice, in part, by its regulation of inflammatory and apoptotic signaling pathways in pericytes.

Associations between exposure to perfluoroalkyl substances and birth outcomes: A meta-analysis.

Although previous meta-analyses have shown that prenatal PFASs exposure is associated with reduction in birth weight, effects of prenatal PFASs exposure on birth outcomes have not been fully explored. We conducted a meta-analysis of 23 eligible studies searched from Embase, PubMed, and Web of Science before March 21, 2021 to analyze the association between prenatal PFASs exposure and birth outcomes, including premature birth (PTB), low birth weight (LBW), small for gestational age (SGA) and miscarriage. Odds ratio (OR) and corresponding confidence intervals were extracted for analysis. According to the heterogeneity of the included studies, fixed-effects (I2 ≤ 50%) and random-effects (I2 > 50%) models were applied respectively. The significant associations between PFOS and PTB (pooled OR = 1.54, 95% CI: 1.20-1.98), PFOA and miscarriage (pooled OR = 1.40, 95% CI: 1.15-1.70), and PFOS and LBW (pooled OR = 1.52, 95% CI: 1.19-1.94) were obtained. There were differences between included studies with different study regions, sampling time, and samples type used for PFASs assessment. These findings may provide insight in risk assessment and decision-making in producing products that contain PFASs.

[Soil ecological stoichiometry characteristics under different types of biological soil crusts in the hilly Loess Plateau region, China]. / 黄土丘陵区不同类型生物结皮下的土壤生态化学计量特征.

Biological soil crusts (biocrusts) play an important role in soil nutrient accumulation and cycling. We examined the relationship between soil nutrient characters and biocrusts types, with six typical types of biocrusts in the hilly Loess Plateau region, including light cyanobacterial crust, dark cyanobacterial crust, cyanobacterial with moss crust (mixed crusts), moss crust, Diploschistes spp. crust, and Nostoc commune crust. The variations of soil carbon (C), nitrogen (N), phospho-rus (P) concentrations and stoichiometric ratios of biocrustal layer and the subsoil under different types of biocrusts were investigated. The results showed that there were significant differences in C, N, P concentrations and stoichiometric ratio among different biocrusts types. The concentrations and stoichiometric ratios of C, N, P in the biocrustal layer were significantly higher than those of 0-10 cm soil beneath biocrusts. The concentrations of C and N significantly decreased with the increases of soil depth across all the biocrusts types. P content showed no variation between soil layers. The concentrations and stoichiometric ratios of C, N, P of moss crust were significantly higher than those of other biocrusts,with C, N, and P content of 27.07, 2.42 and 0.67 g·kg-1. In soil layer of 0-2 cm, the concentrations and stoichiometric ratios of C, N, P under N. commune crust were significantly higher than those of other biocrusts.

[Effects of trampling disturbance on soil organic carbon fractions and mineralization potential of biological soil crusts in the Loess Plateau Region, China]. / 黄土丘陵区踩踏干扰对生物土壤结皮有机碳组分及碳矿化潜力的影响.

The experiment was conducted in the plots that had been enclosed for nearly 20 years in the hilly Loess Plateau region. The effects of trampling disturbance on the biological soil crust (biocrust) coverage, soil organic carbon (SOC), soil easily oxidizable carbon (SEOC), SOC mineralization amount and mineralization rate were investigated. The biocrust SOC mineralization potential after disturbance in different soil layers were simulated by a first-order kinetic equation. The results showed that the coverage of cyanobacteria biocrust and moss biocrust significantly decreased with the increases of disturbance intensity. Compared to no disturbance, the cyanobacteria coverage declined by 264%-339% and moss coverage declined by 46%-127%. Compared to no disturbance, SOC content in biocrust layer significantly decreased by 211%-300%. No significant difference was found among the five disturbance intensities. Disturbance increased SEOC content in biocrust layer, and the variation amounted to 1.5-3.4 g·kg-1, with 30%, 40% and 50% distur-bance differed significantly to no disturbance. Disturbance significantly increased biocrust SOC mineralization cumulative amount. However, SOC mineralization rate did not show any significant change. The SOC mineralization cumulative amount under 40% disturbance intensity increased by 77% compared to that under no disturbance. Disturbance significantly increased SOC mineralization potential in biocrust layer, but with no influence in 0-2 cm and 2-5 cm soil layers. The 40% disturbance intensity significantly increased SOC mineralization potential by 4.7 g·kg-1. The results of principal component analysis showed that SOC, SEOC, SMC and mineralization rate explained 76.7% of the variation of SOC mineralization potential in biocrust layer. Disturbance might be a main factor driving the increases of biocrust SOC mineralization potential in this area.

[Effect of trampling disturbance on soil infiltration of biological soil crusts]. / 踩踏干扰对生物结皮土壤渗透性的影响.

The effect of trampling disturbance on soil infiltration of biological soil crusts was investigated by using simulated rainfall. The results showed that the trampling disturbance significantly increased soil surface roughness. The increasing extent depended on the disturbance intensity. Soil surface roughness values at 50% disturbance increased by 91% compared with the undisturbed treatment. The runoff was delayed by trampling disturbance. A linear increase in the time of runoff yield was observed along with the increasing disturbance intensity within 20%-50%. The time of runoff yield at 50% disturbance increased by 169.7% compared with the undisturbed treatment. Trampling disturbance increased soil infiltration and consequently decreased the runoff coefficient. The cumulative infiltration amount at 50% disturbance increased by 12.6% compared with the undisturbed treatment. Soil infiltration significant decreased when biocrusts were removed. The cumulative infiltration of the treatment of biocrusts removal decreased by 30.2% compared with the undisturbed treatment. Trampling disturbance did not significantly increase the soil loss when the distur bance intensity was lower than 50%, while the biocrusts removal resulted in 10 times higher in soil erosion modulus. The trampling disturbance of lower than 50% on biocrusts might improve soil infiltration and reduce the risk of runoff, thus might improve the soil moisture without obviously increa sing the soil loss.

[Impact of short-term grazing disturbance on nitrogen accumulation of biological soil crusts in the hilly Loess Plateau region, China]. / çŸ­æœŸæ”¾ç‰§å¹²æ‰°å¯¹é»„åœŸä¸˜é™µåŒºç”Ÿç‰©ç»“çš®åœŸå£¤æ°®ç´ ç´¯ç§¯çš„å½±å“.

The variations of total nitrogen, available nitrogen and microbial biomass nitrogen caused by simulated grazing disturbance were investigated in the sixth and twelfth months by using field survey combined with laboratory analysis in order to reveal the sensitivity of nitrogen content in biocrustal soils to disturbance in the hilly Loess Plateau region. The results showed that nitrogen contents in biocrustal soil were sensitive to disturbance. Total nitrogen and available nitrogen in the biocrustal layers were decreased by 0.17-0.39 g·kg-1 and 1.78-5.65 mg·kg-1 during the first half-year compared to the undisturbed treatment, and they were found respectively decreased by 0.13-0.40 g·kg-1 and 11.45-32.68 mg·kg-1 one year later since disturbance. The content of microbial biomass nitrogen in the biocrustal layer was reduced by 69.99-330.97 mg·kg-1, whereas the content was increased by 25.51-352.17 mg·kg-1 in soil of 0-2 cm layer. The induction of nitrogen accumulation depended on the intensity of disturbance. Slight variation was observed in the nitrogen accumulation in biocrustal layer under 20% and 30% disturbance, while significant reduction was found in the 40% and 50% disturbance. Significant reduction was detected only in nitrogen accumulation in the biocrustal layers, whereas no significant influence was found in the top 5 cm soil layer.

Polychlorinated biphenyls and breast cancer: A congener-specific meta-analysis.

The incidence of breast cancer is related to various risk factors, especially that the environmental and lifestyle factors account for major contribution at the rate of 70% to 95% over all. However, there still remains some controversy over the epidemiological evidence regarding the effects of environmental carcinogens on the risk of breast cancer. We conducted a quantitative meta-analysis aiming at full evaluation of the effects of polychlorinated biphenyls (PCBs) on breast cancer in a congener-specific fashion. Four online literature databases were systematically searched before 1st January 2015, for studies stating correlation between PCB congeners and breast cancer. The Newcastle-Ottawa Scale was used to evaluate the quality of the studies that were included in our analysis. Sixteen studies were included in our final meta-analysis after screening based on the priori inclusion criteria. Nine PCB congeners were reported by more than two studies and they were presented in detail. The pooled Odds Ratios (ORs) showed a significant increase in the risk of breast cancer in individuals with higher plasma/fat levels of PCB 99 (OR: 1.36; 95% CI: 1.02 to 1.80), PCB 183 (OR: 1.56; 95% CI: 1.25 to 1.95) and PCB 187 (OR: 1.18; 95% CI: 1.01 to 1.39). Besides, the outcomes did not support a relationship between dioxin-like PCB congeners and the risk of breast cancer. The results of our meta-analysis imply that PCB 99, PCB 183 and PCB 187 would increase the risk of breast cancer. The mechanism of this increased risk may be by the induction of the CYP2B family in cytochrome P450 enzymes.