Effects of drynaria total flavonoids on serum levels of leptin,interleukin 6, prostaglandin E2 and expression of bone β2-adrenergic receptor in ovariectomized osteoporosis rats

AIM: To investigate the effects of drynaria total flavonoids on serum levels of leptin (LEP), interleukin 6(IL-6), prostaglandin E₂(PGE₂) and the expression of bone β₂-adrenergic receptor (ADRB2) in a rat model of ovariectomized osteoporosis(OP). METHODS: The osteoporosis model was established by ovariectomy. Twelve weeks after modeling,bone mineral density (BMD) was determined by dual-energy X-ray absorptiometry to verify successful modeling.Enzyme-linked immunosorbent assay was applied to detect the concentrations of LEP, IL-6 and PGE₂ in serum. The expression of ADRB2 was determined by immunohistochemical technique. RESULTS: Compared with sham group,BMD of the rats in model group significantly decreased in multiple regions 12 weeks after modeling(P<0.01). The serum levels of LEP, IL-6 and PGE₂ in model group were significantly higher than those in sham group(P<0.05). The levels of LEP, IL-6 and PGE₂ in drynaria total flavonoids group were significantly lower than those in model group(P<0.01). No significant difference of PGE₂ between these 2 groups was observed. The ADRB2 expression in sham group and treatment group was significantly different from that in model group, and no significant difference between sham group and treatment group was found. CONCLUSION: The serum levels of LEP, IL-6 and PGE₂ and the expression of bone ADRB2 increased in OP rats.Drynaria total flavonoids reduce the production of LEP, IL-6 and the expression of ADRB2, and suppress the bone absorption, which may be one of the mechanisms in treating OP.     

Lipoxin A4 reduces lipopolysaccharide-induced expression of cyclooxygenase 2 and prostaglandin E2 in human bronchial epithelial cells

AIM: To explore the effects of lipoxin A₄ on the expression of cyclooxygenase 2 (COX-2) in human bronchial epithelial cells (HBECs). METHODS: HBECs were incubated with various concentrations (0.1, 1 and 10 mg/L) of lipopolysaccharide(LPS) for 9 h, or 1 mg/L LPS for different time (3 h, 6 h and 9 h). The levels of COX-2 mRNA in HBECs and prostaglandin E₂ (PGE₂) in the culture supernatant were measured. In addition, the HBECs were exposed to lipoxin A₄ at concentration of 0, 100 and 400 μmol/L after stimulated with LPS at concentration of 1 mg/L for 9 h, and the supernatant of the culture cells was collected for determining the content of PGE₂ by ELISA. The cells were also harvested, and the mRNA and protein levels of COX-2 were analyzed by RT-PCR and Western blotting, respectively. RESULTS: LPS increased the mRNA expression of COX-2 and production of PGE₂ in a dose and time dependent manners in HBECs. Induction of COX-2 mRNA and protein by LPS were inhibited by lipoxin A₄ in a dose-dependent manner. Lipoxin A₄ also significantly decreased LPS-induced production of PGE₂. CONCLUSION: Lipoxin A₄ down-regulates LPS-induced expression of COX-2 and consequently inhibits the production of PGE₂ in HBECs.     

Changes of PGE2, PGI2 and TXA2 concentration in rat traumatic pulpitis

AIM: To study the relationship between prostaglandins and acute pulpitis. METHODS: Rat traumatic pulpitis model was established by pulp exposure. The kinetic pathological changes in dental pulpal tissues and changes of PGE₂,6-Keto-PGF_1α and TXB₂ concentration in dental pulp were observed. RESULTS: After pulpal trauma, the dental pulp showed inflammatory changes and the concentrations of PGE₂,6-Keto-PGF_1α and TXB₂ were increased, which peaked at 6 hour post-trauma. CONCLUSION: Prostaglandins play a significant role in the pathogenesis of pulpitis.     

Effect of IL-10 on IL-1β-induced cyclooxygenase-2 expression and prostaglandin E2 release in human mesangial cells

AIM: To investigate the effect of IL-10 on IL-1β-induced prostaglandin E₂(PGE₂) release and cyclooxygenase-2(COX-2) expression in human mesangial cells and to examine whether IL-10 has effect on the biological function of IL-1β.METHODS: The PGE₂ concentration in supernatants of HMC was measured by radioimmunoassay. The COX-2 mRNA and protein were measured by RT-PCR and Western blot, respectively. RESULTS: PGE₂ and COX-2 were significantly increased after treatment with IL-1β(P＜0.01 for both) in cultured human mesangial cells. IL-10 had no effects on basical production of COX-2 and PGE₂(P＞0.05, respectively), while it inhibited IL-1β-elicited PGE₂ production, as well as COX-2 mRNA and protein expression in a concentration-dependent fashion. CONCLUSIONS: These results indicated that IL-10 depressed the IL-1β-induced release of PGE₂ and expression of COX-2. These data suggested that IL-10 could exert anti-inflammatory actions at several levels, not only by inhibiting the production of pro-inflammatory cytokines but also by suppressing their biological function.     

Changes of serum autoantibodies against β1 and M2 receptors in the patients of obstructive sleep apnea syndrome with chronic obstructive pulmonary disease

AIM: To study the changes of serum autoantibodies against β₁-adrenergic and M₂-muscarinic receptors in obstructive sleep apnea syndrome (OSAS) patients with chronic obstructive pulmonary disease (COPD), that is, overlap syndrome (OS). METHOD: Serum autoantibodies against β₁ and M₂ receptors in 26 cases with OS, 32 with OSAS, 30 with COPD and 28 normal subjects were determined by using enzyme-linked immunosorbent assay(ELISA). RESULTS: The positive rates and titer of β₁ and M₂ receptor autoantibodies are significantly increased in OS group (92.2％,57.7% and 1:98, 1:67), compared to OSAS (71.9%, 40.6% and 1:83, 1:30) or COPD group (70.0%, 36.7% and 1:79, 1:28) (P＜0.05), and they are higher in these groups than in the control (25.0%, 14.3% and 1:20, 1:20) (P＜0.01). CONCLUSION: Serum β₁-and M₂ receptor autoantibodies are significantly increased in the patients with COPD, OSAS or OS, compared to the control, and the highest is in OS.     

Effects of different doses of L-dopa on rotational behavior and amounts of cells expressing D2 receptors in hemiparkinsonian rats

AIM：To observe the effects of different doses of L-dopa on the rotational behavior and amounts of cells expressing D₂ receptors in striatum in hemiparkinsonian rats.METHODS：A hemiparkinsonian model was established in rats by pretreatment with 6-hydroxydopamine.The D₂ receptor expression were detected by immunohistochemical staining.The numbers of rotations induced by apomorphine was counted within 30 min before and after L-dopa (10 mg·kg^-1·d^-1,50 mg·kg^-1·d-^-1 or 100 mg·kg^-1·d^-1,ip) was introduced to Parkinson’s disease (PD) model rats for 15 days.RESULTS：In successful PD model rats,the increased percentage of D₂ receptor in lesioned side compared with intact side was associated linearly with the numbers of rotations within 30 min (r=0.927,P<0.01).After high dose of L-dopa intervention to PD model,the numbers of rotations decreased significantly (P<0.05),the amounts of cells expressing D₂ receptor at the lesioned side striatum decreased significantly (P<0.01).CONCLUSION：After high dose of L-dopa intervention,rotation behavior of PD rats improves,and D₂ receptor is down-regulated significantly.     

Effects of shading and NO3:NH4 ratio on the yield,quality and N metabolism in strawberry

The effect of 50% shading and NO₃:NH₄ ratio (0:100, 75:25, 50:50, and 25:75) in the nutrient solution on growth, yield, quality and N metabolism in hydroponically grown strawberry (Fragaria × ananassa var Camarosa) was evaluated. Both fresh and dry weights of leaves were significantly lower when a high concentration of either NO₃ (100%) or NH₄ (75%) was the sole N source in the nutrient solution. In unshaded plants, increasing of both NH₄ and NO₃ ratio in the nutrient solution reduced photosynthetic (Pn) rate, however in shaded plants the reduction of Pn became more pronounced at a higher ratio of NH₄ in the nutrient solution. The yield in terms of fresh and dry weight of fruit per plant was significantly increased at the 75:25 and 50:50 (NO₃:NH₄) treatments. Fruit size was significantly affected by the treatments, so that the biggest fruits in both shaded and unshaded plants were obtained under the 75:25 and 50:50 (NO₃:NH₄) treatments. Total soluble solid (TSS) in unshaded plants was increased with increasing NH₄ ratio in the nutrient solution, however in shaded plants it was reduced at high NH₄ ratio in the nutrient solution. In both shaded and unshaded plants, higher concentration of NH₄ significantly reduced the post-harvest life of the fruits. The increase of tissue N concentration was nearly proportional to the NH₄ concentration in the nutrient solution. The activity of nitrate reductase (NR) was increased by increasing NH₄ from 0 to 50% and then reduced at a higher ratio of NH₄ in the solution. Shading increased NH₄ concentration so that the shaded plant had nearly twice as high NH₄ concentration in the leaves. The increase of NH₄ concentration induced by shading could be partially the reduction of NH₄ assimilate because of the shortage of carbohydrate.     

Mouse early integral embryo induces expression of endometrial integrin β3 and leukaemia-inhibitory factor,and improves uterine receptivity in mice

AIM: To investigate the changes of endometrial receptivity under the effect of mouse embryo both in vitro and in vivo, and to figure out which part of the embryo induces the change. METHODS: Scanning electron microscope was applied to observe the pinpode formation on day 4 endometrium both in vitro and in vivo. The expression of integrin β₃ and leukaemia-inhibitory factor(LIF) on day 2 pregnant mouse endometrium , day 4 endometrium after co-culture for 2 d with day 2 embryo , blastomere and zona pellucida as well as control group in vitro were detected by the methods of fluorescent quantitative PCR, immunohistochemistry and Western blotting. The same tests were conducted in the in vivo part of the experiment with the integral embryo or different parts of the embryo being transferred to pseudopregnant mouse uterus. On day 4 of the pregnancy, the endometrium was extracted to carry out the tests. RESULTS: After co-cultured for 2 d with whole embryo, the experssion of integrin β₃ and LIF was higher than that in any other group in the in vitro part. The expression of integrin β₃ and LIF on day 4 of normal pregnancy was higher than that in any other group in the in vivo experiments. CONCLUSION: Mouse embryo as a whole is able to induce better endometrial receptivity, while any separated part of embryo, such as blastomere or zona pellucida, couldn't.     

Protein expression of cyclin D2 and p16 in proliferation and differentiation of cultured cardiac myocytes

AIM:To investigate the protein expression of cyclin D₂ and p16 in proliferation and differentiation of cultured cardiac myocytes.METHODS:One-day-old Sparague-Dawley rats were used. Cardiac myocytes(CM) were collected by a trypsin-dispersal method and cultured. Cell growth line and fluorescence activated cell sorting (FACS) were used to investigate the proliferation of CM. Ultra-thin sections were made to observe the ultrastructure of CM under transmission electron microscope. The expression of cyclin D₂ and p16 in CM were measured using immunocytochemistry and image analysis.RESULTS:①Results of cell growth line and FACS analysis showed that cultured CM could proliferate in the first 3 cultured days, but the ability decreased quickly, concomitant with differentiation. CM was obseved quiescent in cell cycle three days later. The ultrastructure of CM showed the large amount of myofilaments and mitochondrion. ②The protein expression of cyclin D₂ in 3,4,5 day CM group was 0.89 times(P＜0.05),0.80 times (P＜0.05) and 0.56 times (P＜0.01) of that in 1 day group, respectively. The expression of p16 in CM was increased during the culture process, 2,3,4,5 day group were 1.63 times, 1.72 times, 1.99 times and 2.84 times (P＜0.01) of that in 1 day group, respectively.CONCLUSION:Cultured neonatal rat cardiac myocytes could proliferate during the first 3 days after incubation, but the ability of proliferation decreased, from the fourth day, concomitant with differentiation. Cyclin D₂ and p16 play the key roles in CM postnatal development. Downregulation of cyclin D₂ and upregulation of p16 may induce CM differentiation.     

Effects of NH4:NO3:urea ratio on cut roses yield, leaf nutrients content and proton efflux by roots in closed hydroponic system

The effects of the NH₄:NO₃ ratio in replenishment solution on Rosa L. flower yield and the impact of NH₄ substitution by urea on plant performance and on solution EC and pH have not been studied previously in closed (no leaching) hydroponic systems. A greenhouse experiment with six NH₄:NO₃:urea ratios (0:100:0, 12:88:0, 25:75:0, 50:50:0, 100:0:0 and 0:50:50) and two harvest cycles (winter and spring) was carried out to investigate these relationships. In winter, total and >40 cm cut flower yields were maximal in treatment 25:75:0. At lower NH₄ percentages (12.5:87.5:0 and 0:100:0), growth container solution pH varied between 7.8 and 8.5, reducing P, Ca and Mn concentration in leaves and increasing dry matter allocated to them. At higher NH₄ percentages, Ca uptake was inhibited, solution pH reached 3, and %P in leaves increased. Consequently, reducing sugars concentration in leaves increased and sucrose and starch concentrations decreased. A stepwise regression analysis indicated that the optimal NH₄:NO₃ ratio in feed solution is 40:60, with resulting solution pH of 5.9 in the growth container. In spring the maximum yield was obtained in treatment 0:50:50 and it exceeded the winter yield despite a higher solution EC (4.3 dS m⁻¹ vs. 3.5 dS m⁻¹ at harvest). The beneficial effect of urea (0:50:50 vs. 50:50:0) stemmed from the relatively lower NH₄ concentration in solution, that alleviated the NH₄–Ca uptake competition, and higher pH. The slope of the straight line relating [H⁺ efflux rate] to [NH₄⁺ uptake rate] in treatments 25:75:0, 50:50:0 and 100:0:0 was 0.44 mol H⁺/mol NH₄. In all other treatments the proton efflux was negligible.     

Association among COX2, iNOS and p38MAPK in late phase of preconditioning in rat cardiomyocytes

AIM:To explore the association among COX₂ , iNOS and p38MAPK in late phase of preconditioning. METHODS: The expression of COX₂ , iNOS and p38MAPK activity were determined by western blotting and the injury of cardiomyocyte was assessed by LDH release and trypan blue exclusion in four groups: control group, group IPC (ischemic preconditioning), group SMT (iNOS inhibitor), group NS₃₉₈ (COX₂ inhibitor) and group SB (p38MAPK inhibitor).RESULTS:The expression of COX₂ in group IPC increased markedly in comparision with group SMT and group SB.The expression of iNOS in group SB was lower than that in group IPC and group NS₃₉₈.The difference of the amount of iNOS was not significant between group IPC and group NS₃₉₈.The difference of the amount of phospho-p38MAPK was not significant among group IPC, group SMT and group NS₃₉₈(P>0.05).The LDH was lower, and cell viability was higher in group IPC than those in control group.The LDH was higher, and cell viability was lower in group SMT, group NS₃₉₈ and group SB than those in group IPC. CONCLUSIONS:In late phase of preconditioning , the p38MAPK activity and expression of iNOS and COX₂ increase significantly in rat cardiomyocytes, activited p38MAPK mediates iNOS, then promotes COX₂ expression.     

IgA1 from patients with IgA nephropathy induced release of calcium,up-regulation of TGF-β mRNA expression and secretion of fibronectin in human glomerular mesangial cells

AIM: To study and compare the pathophysiological effects of serum IgA₁ from both the patients with IgA nephropathy (IgAN) and healthy controls on human mesangial cells (HMC). METHODS: Serum IgA₁ was isolated with Jacalin affinity chromatography and heated to form aggregates (aIgA₁). Primary HMC were cultured and passage 3 and passage 4 of the cells were used. Intracellular calcium release was assayed with confocal analysis. Expression of TGF-β mRNA and the content of supernatant fibronectin were tested by RT-PCR and indirect competitive ELISA, respectively. RESULTS: aIgA₁ from patients with IgAN was shown to induce release of intracellular calcium, up-regulation of expression of TGF-β mRNA and secretion of fibronectin in HMC in a similar time-dependent manner as aIgA₁ from healthy controls, but the effects of the former were much stronger and the durations was much longer (P<0.05, respectively). CONCLUSION: IgA₁ from patients with IgAN was shown to be able to stimulate HMC with a stronger biological effects than that from healthy controls. It is suggested that direct interaction between IgA₁ from patients with IgAN and HMC may be another mechanism in the pathogenesis of IgAN.     

Effect of tea-polyphenols on the activation of NF-κB and the expression of TGF-β1 mRNA in THP-1 cells incubated with VLDL,LDL or ox-LDL

AIM:To investigate the effect of tea-polyphenols (TP) on the activation of NF-κB and the expression of TGF-β₁ mRNA in THP-1 cells (a human acute monocytic leukemia cell line). METHODS:THP-1 cells were incubated with the different concentrations of TP, VLDL, LDL or ox-LDL. In the THP-1 cellls, the nuclear malposition rate of NF-κB was detected with immunohistochemistry technique, the positive index of the TGF-β₁ mRNA expression was detected by hybridization in situ, and accumulation of total cholesterol (TC) in cells incubated with 0.4-40 μg/L TP was determined with oxidase assay. RESULTS:The nuclear malposition rate of NF-κB, the positive index of the TGF-β₁ mRNA expression and TC in THP-1 cells incubated with 0.4-40 μg/L of TP were lower than those with 0 μg/L of TP in TP-V group, TP-L group and TP-O (P＜0.05). The differences of these markers in THP-1 cells incubated with more than 40 μg/L TP in TP-V group, TP-L group and TP-O were not statistically significant, compared with TP-C group (P＞0.05). CONCLUSION:TP inhibited the activation of NF-κB, the expression of TGF-β₁ mRNA and the foam cell formation in the mono-macrophage.     

Induction of lateral branches in tree fruit nursery stock with propyl 3-t-butylphenoxy acetate (MB 25, 105) and Promalin (GA4+7 + 6-benzyladenine)

Sprays with 250–2000 mg l^?1 propyl 3-t-butylphenoxy acetate (MB 25,105) and 250 and 500 mg l^?1 GA₄₊₇ + 6-benzyladenine (Promalin) were applied to scion growth of first nursery trees of ‘Bartlett’ pear (Pyrus communis L.), ‘Bing’ cherry (Prunus avium L.) and ‘Oregon Spur II Delicious’ apple (Malus domestica Borkh.) to stimulate lateral branching in the nursery. Most treatments significantly increased branching compared to untreated controls. Combination sprays of the two chemicals were usually better than either used alone. Chemical treatment usually produced greater branching and wider branch angles than mechanical heading. Both chemical and mechanical treatments reduced tree height and caliper, but the decrease was not always statistically significant.