Influence of endogenous ciliary neurotrophic factor on neural differentiation of adult rat hippocampal progenitors

Ciliary neurotrophic factor is the only known neurotrophic factor that can promote differentiation of hippocampal neural progenitor cells to glial cells and neurons in adult rats. This process is similar to spontaneous differentiation. Therefore, ciliary neurotrophic factor may be involved in spontaneous differentiation of neural stem cells. To verify this hypothesis, the present study isolated neural progenitor cells from adult male rats and cultured them in vitro. Results showed that when neural progenitor cells were cultured in the absence of mitogen fibroblast growth factor-2 or epidermal growth factor, they underwent spontaneous differentiation into neurons and glial cells. Western blot and immunocytochemical staining showed that exogenous ciliary neurotrophic factor strongly induced adult hippocampal progenitor cells to differentiate into neurons and glial cells. Moreover, passage 4 adult hippocampal progenitor cells expressed high levels of endogenous ciliary neurotrophic factor, and a neutralizing antibody against ciliary neurotrophic factor prevented the spontaneous neuronal and glial differentiation of adult hippocampal progenitor cells. These results suggest that the spontaneous differentiation of adult hippocampal progenitor cells is mediated partially by endogenous ciliary neurotrophic factor.

The effect of endogenous transforming growth factor β_1 on the growth of bladder cancer cells in vitro

Objective To investigate the influence of endogenous transforming growth factor β1(TGFβ1) on the cell cycle regulation and proliferation of bladder cancer. Methods A constructed replication defective retroviral vector pRevTβ-AS, which carried antisense RNA of TGFβ1.was transfected to a bladder cancer cell line EJ. The proliferation and clone-formation of transferred cells were observed in vitro,and the alteration of cell cycle was also detected by flow cytometric analysis. Results TGFβ1 antisense RNA was transferred into EJ cell and expressed efficiently. After the inhibition of target gene expression in EJ cells, the reduced growth and clone-formation rates were demonstrated, and the proliferative indexes were decreased by 12 % . The ratios of GO and G1 stage cells to June 2003 Vol12 No2 the antisense RNA-transfected EJ cells were increased, simultaneously,the ratio of S stage cells to the antisense RNA-transfected EJ cells ratios were decreased, compared with the control group. Conclusion The

Tree mortality and biomass loss in drought-aff ected forests of East Texas,USA

Changes in tree mortality due to severe drought can alter forest structure,composition,dynamics,ecosystem services,carbon fl uxes,and energy interactions between the atmosphere and land surfaces.We utilized long-term(2000‒2017,3 full inventory cycles)Forest Inventory and Analysis(FIA)data to examine tree mortality and biomass loss in drought-aff ected forests for East Texas,USA.Plots that experienced six or more years of droughts during those censuses were selected based on 12-month moderate drought severity[Standardized Precipitation Evaporation Index(SPEI)-1.0].Plots that experienced other disturbances and inconsistent records were excluded from the analysis.In total,222 plots were retained from nearly 4000 plots.Generalized nonlinear mixed models(GNMMs)were used to examine the changes in tree mortality and recruitment rates for selected plots.The results showed that tree mortality rates and biomass loss to mortality increased overall,and across tree sizes,dominant genera,height classes,and ecoregions.An average mortality rate of 5.89%year−1 during the study period could be incited by water stress created by the regional prolonged and episodic drought events.The overall plot and species-group level recruitment rates decreased during the study period.Forest mortality showed mixed results regarding basal area and forest density using all plots together and when analyzed the plots by stand origin and ecoregion.Higher mortality rates of smaller trees were detected and were likely compounded by densitydependent factors.Comparative analysis of drought-induced tree mortality using hydro-meteorological data along with drought severity and length gradient is suggested to better understand the eff ects of drought on tree mortality and biomass loss around and beyond East Texas in the southeastern United States.

The F-measure for Research Priority

Purpose： In this contribution we continue our investigations related to the activity index （A/） and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach： We point out that fluctuations in the value of the AI for a given country and domain are never the result of that country＇s policy with respect to that domain alone because there are exogenous factors at play. For this reason we introduce the F-measure. This F-measure is nothing but the harmonic mean of the country＇s share in the world＇s publication output in the given domain and the given domain＇s share in the country＇s publication output.Findings： The F-measure does not suffer from the problems the AI does Research limitations： The indicator is not yet fully tested in real cases R＆D policy management： In policy considerations, the AI should better be replaced by the F-measure as this measure can better show the results of science policy measures （which the AI cannot as it depends on exogenous factors）. Originality/value： We provide an original solution for a problem that is not fully realized by policy makers.

Activation of angiotensin Ⅱ type 1 receptors in the median preoptic nucleus induces a diuretic and natriuretic response in rats

Objective： To investigate the effect of activation of angiotensin Ⅱ（AngⅡ） type 1 （AT1） receptors in the median preoptic nucleus （MnPO） of rats on renal sodium excretion. Methods： After anesthesia, the rats were injected into the MnPO via an implanted cannula. Urine samples were collected via a bladder cannula, and the urine sodium concentration was assayed with flame spectrophotometry. The serum level of endogenous digitalis-like factor （EDLF） and Na^＋,K^＋-ATPase activity in the renal cortex tissue were assayed respectively with a radioimmunoassay and with an ammonium molybdophosphate-based kit. Results： Both the urinary volume and the sodium excretion peaked 60 min after AngⅡ was administered into the MnPO. The responses were accompanied by an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex. The responses of diuresis and natriuresis, as well as an increase in serum EDLF and a decrease in Na^＋,K^＋-ATPase activity in the renal cortex induced by MnPO adminstration with AngⅡ were inhibited by pior treatment with the AngⅡ receptor blocking agent losartan into the MnPO. Conclusion： These results suggest that activation of AT1 receptors in the MnPO of rat induces diuretic and natriuretic responses. The responses are associated with an increase release of EDLF and with the inhibition of Na^＋,K^＋-ATPase activity in renal cortex tissue.

Multiple hemodynamic effects of endogenous hydrogen sulfide on central nervous system in rats

Background Endogenous hydrogen sulfide is a new neuromodulator which takes part in the regulation of central nervous system physiology and diseases. Whether endogenous hydrogen sulfide in the central nervous system regulates cardiovascular activity is not known. In the present study, we observed the hemodynamic changes of hydrogen sulfide or its precursor by intracerebroventricular injection, and investigate the possible roles of endogenous digitalis like factors and sympathetic activity in the regulation. Methods Ninety-four Sprague-Dawley rats underwent a right cerebroventricular puncture, then the hydrogen sulfide saturation buffer or its precursor injected by intrcerebroventricular catheter. A heperin-filled catheter was inserted into the right femoral artery or into the left ventricle, and changes of blood pressure or cardiac function recorded by a Powerlab/4S instrument. Phentolamine or metoprolol were pre-injected to observe the possible role in autonomic nerve activity. After rats were sacrificed, plasma was collected and endogenous digitalis-like factors were measured with a commercial radioimmunoassay kit. The aortic, cardiac sarcolemmal vesicles were isolated and the activity of Na＋-K＋-ATPase was measured as ouabain-sensitive ATP hydrolysis under maximal velocity conditions by measuring the release of inorganic phosphate from ATP. Unpaired Student＇s ttest for two groups or analysis of variances （ANOVA） for multiple groups were used to compare the differences of the changes. Results Intracerebroventricular injection of hydrogen sulfide induced a transient hypotension, then dramatic hypertenive effects in a dose-dependent manner. Bolus injection of L-cysteine or beta-mercaptopyruvate also increased mean arterial pressure （P 〈0.01）, whereas hydroxylamine-a cystathionine beta synthase inhibitor decreased the arterial pressure （P 〈0.01）. Hydrogen sulfide and L-cysteine increased mean arterial pressure, left ventricular develop pressure and left-ventricle maximal rate of systolic and diastolic pressure; these functions were decreased by hydroxylamine （P 〈0.01）. Glibenclamide （a KATP channel blocker） blocked the transient hypotensive effect, phentolamine （an alpha-adrenergic receptor blocker） blocked the hypertensive effect, and metoprolol （a selective beta 1 receptor blocker） blocked the positive inoptropic effect of central nervous system hydrogen sulfide. The endogenous digitalis-like factors in plasma were elevated （P 〈0.01） after treatment with L-cysteine, association with decreasing Na＋-K＋-ATPase activity in cardiac or aortic sarcolemmal vesicles （P 〈0.01）. Hydroxylamine injection reduced the endogenous digitalis-like factors level in plasma association with increasing Na＋-K＋-ATPase activity in cardiac and aortic sarcolemmal vesicles. Conclusion Central nervous system endogenous hydrogen sulfide upregulated mean arterial pressure and cardiac systolic function by activation of sympathetic nerves or release of endogenous digitalis-like factors.

Synthetic Study on Polyhydroxyestrogens Modeled for Inagami-Tamura Endogenous Digitalis-like Factor and Their Activity

1 Results Mammalian possess receptors for digitalis,cardiac glycosides,derived from plants.As one of the results from studies on a real endogenous ligand for the receptors,so called an endogenous digitalis-like factor (EDF) or substance (EDS),Inagami and Tamura isolated a promising candidate possessing a molecular weight,336.We elucidated several possible structures (Fig.1) for the factor and synthesized several modeled compounds,some of which exhibited remarkable constriction at higher concentrations t...

Sensitive skin syndrome: Research progress on mechanisms and applications

Sensitive skin is a clinical syndrome characterized by a hyper-reactive state of the skin,primarily on the face.It is accompanied by subjective symptoms such as burning,stinging,itching,and tightness when exposed to physical,chemical,or psychological stimuli.Objective signs,such as erythema,scales,and dilated blood vessels,may or may not be present.The discomfort associated with sensitive skin can be triggered by various endogenous and exogenous factors,which usually have no significant effect on the individual and do not induce irritant reactions.Sensitive skin often presents as a subjective state without clinical signs and exhibits diversity,posing challenges in sensitive skin research and care.This review summarizes the prevalence,key factors,pathophysiological mechanisms,diagnosis,and progress in daily care for sensitive skin.The aim is to provide a clearer and more systematic understanding of sensitive skin and offer guidance for sensitive skin care.

Recapitulation of growth factor-enriched microenvironment via BMP receptor activating hydrogel

Exposure to a growth factor abundant milieu has remarkable regenerative and rejuvenating effects on organ diseases,tissue damage,and regeneration,including skeletal system defects and bone regeneration.Although the introduction of candidate growth factors into relevant fields has been reported,their regenerative effects remain unsatisfactory,mainly because of the experimental challenges with limited types of growth factors,elusive dosage adjustment,and asynchronous stem cell activation with cytokine secretion.Here,an innovative hydrogel recapitulating a growth factor-enriched microenvironment(GEM)for regenerative advantage,is reported.This sulfated hydrogel includes bone morphogenetic protein-2(BMP-2),an essential growth factor in osteogenesis,to direct mesenchymal stem cell(MSC)differentiation,stimulate cell proliferation,and improve bone formation.The semi-synthetic hydrogel,sulfonated gelatin(S-Gelatin),can amplify BMP-2 signaling in mouse MSCs by enhancing the binding between BMP-2 and BMP-2 type II receptors(BMPR2),which are located on MSC nuclei and activated by the hydrogel.Importantly,the dramatically improved cytokine secretion of MSCs throughout regeneration confirms the growth factor-acquiring potential of S-Gelatin/rhBMP-2 hydrogel,leading to the vascularization enhancement.These findings provide a new strategy to achieve an in situ GEM and accelerated bone regeneration by amplifying the regenerative capacity of rhBMP-2 and capturing endogenous growth factors.