MiR-4262 regulates differentiation and osteogenesis of humanperiodontal stem cells by targeting suppressor of cytokinesignaling 4

Periodontitis,as a chronic inflammatory disease,remains unsolved,and the pathogenesis of this disease has not been fully elucidated.In this study,the effect of miR-4262 was investigated in tumor necrosis factor-α(TNF-α)induced human periodontal stem cells(hPDLSCs)for the first time.The gene expression involved in this study was determined using polymerase chain reaction(PCR),the expressions of relevant proteins were determined by western blot analysis,and the levels of IL-1β,IL-6,and MCP-1 were estimated by enzyme-linked immunosorbent assay(ELISA)assay.The luciferase reporter assay was performed for verification of the target gene,alkaline phosphatase(ALP)activity detection was used for differentiation capacity,and alizarin red staining assay was used for mineralization capacity.The inhibition of miRNA-4262,which resulted in the upregulation of suppressor of cytokine signaling 4(SOCS4),showed protective effects,including anti-inflammation and promotional effects on osteogenesis as well as differentiation in TNF-αinduced hPDLSCs.These results provided insights into the roles of miRNAs in regulating the inflammatory response,differentiation,and osteogenesis in hPDLSCs,which may promote the understanding of the mechanisms of periodontitis and find out a better therapeutic application.

EVAPORATION AND WATER BALANCE IN ARID LAND——AN EXAMPIE IN TURPAN,XINJIANG,CHINA

This paper discussed some observation and calculation methods of evaporation and itscharacteristics in arid land taken an example in Turpan, Xinjiang, China by using the dataobtained from July 1, 1991 to June 30, 1992 in the observation station which was settled forthe Japan-China cooperation study in the marginal area of an oasis in Turpan, Xinjiang,China. It is pointed out that due to very low water content in arid land, real evaporation de-

干旱区蒸发与水分平衡的研究——以新疆吐鲁番为例

1.引言了解蒸发和水分平衡特征对干旱区农业的持续发展十分重要。根据气象资料,中国干旱区蒸发皿测得的蒸发量是降水量的10到150倍(Du,1993)。以新疆吐鲁番(40°56′N,89°12′E,34.5m)为例,图1给出了温度,皿蒸发量和降水量的年度变化(日平均,最高和最低)。吐鲁番年降水量只有16mm,而皿蒸发量却达2838mm。

Altitudinal variation of ecosystem CO_(2) fluxes in an alpine grassland from 3600 to 4200 m

Aims Recent studies have recognized the alpine grasslands on the Qinghai-Tibetan plateau as a significant sink for atmospheric CO_(2).The carbon-sink strength may differ among grassland ecosystems at various altitudes because of contrasting biotic and physical environments.This study aims(i)to clarify the altitudinal pattern of ecosystem CO_(2) fluxes,including gross primary production(GPP),daytime ecosystem respiration(Redaytime)and net ecosystem production(NEP),during the period with peak above-ground biomass;and(ii)to elucidate the effects of biotic and abiotic factors on the altitudinal variation of ecosystem CO_(2) fluxes.Methods Ecosystem CO_(2) fluxes and abiotic and biotic environmental factors were measured in an alpine grassland at four altitudes from 3600 to 4200 m along a slope of the Qilian Mountains on the northwestern Qinghai-Tibetan Plateau during the growing season of 2007.We used a closed-chamber method combined with shade screens and an opaque cloth to measure several carbon fluxes,GPP,Redaytime and NEP,and factors,light-response curve for GPP and temperature sensitivity of Redaytime.Above-and below-ground biomasses and soil C and N contents at each measurement point were also measured.Important Findings(i)Altitudinal pattern of ecosystem CO_(2) fluxes:The maximum net ecosystem CO_(2) flux(NEPmax),i.e.the potential ecosystem CO_(2) sink strength,was markedly different among the four altitudes.NEPmax was higher at the highest and lowest sites,ap proximately
7.460.9 and
6.760.6 lmol CO_(2) m^(-2)s^(-1)(mean 6 standard error),respectively,but smaller at the intermediate altitude sites(3800 and 4000 m).The altitudinal pattern of maximum gross primary production was similar to that of NEPmax.The Redaytime,however,was significantly higher at the lowest altitude(3.460.3 lmol CO_(2) m^(-2)s^(-1))than at the other three altitudes.(ii)Altitudinal variation of vegetation biomass:The aboveground biomass was higher at the highest altitude(154627 g DW m
2)than at the other altitudes,which we attribute mainly to the large biomass in cushion plants at the highest altitude.The small above-ground biomass at the lower altitudes was probably due to heavy grazing during the growing season.(iii)Features of ecosystem CO_(2) fluxes:Redaytime and GPP were positively correlated with above-ground biomass.The low ratio of Redaytime to GPP at either the measurement point or the site level suggests that CO_(2) uptake efficiency tends to be higher at higher altitudes,which indicates a high potential sink strength for atmospheric CO_(2) despite the low temperature at high altitudes.The results suggest that the effect of grazing intensity on ecosystem carbon dynamics,partly by decreasing vegetation biomass,should be clarified further.

Species richness and species composition of fungal communities associated with cellulose decomposition at different altitudes on the Tibetan Plateau

Aims The aims of this study were to compare the fungal communities developing on cotton strips at three different altitudes on the Tibetan Plateau and to assess the environmental variables influencing them.Methods Cotton strips that had been buried in soil for a year were sampled at three sites at different altitudes(4500,4950 and 5200 m)located on a southeast-facing slope on the Nyainqentanglha Mountains near Damxung.The fungi on the cotton strips were isolated using a modified washing method.The decomposition abilities and colony growth properties of the major species cultured in pure-culture conditions were investigated and compared.Canonical correspondence analysis(CCA)was used to evaluate the relationships between fungal community composition and environmental variables(altitude,soil depth,soil water content[SWC],plant root mass and gravel content).Important Findings A total of 24 species were isolated from the cotton strips,and 12 species occurred frequently and were regarded as major species.The number of fungal species was lower at the 4950-m altitude site than at the other two sites,indicating that not only altitude but also other factors affected the number of species present.All of the major species were able to decompose the cotton strips.In the CCA ordination,automatic forward selection revealed that altitude,SWC and plant root mass significantly affected fungal species composition.Our results suggest thatspecies numberandthecomposition ofcellulolytic fungal communities are highly correlated with environmental variables as well as altitude in the alpine meadow on the Tibetan Plateau.