AP-1 and NF-κB transcriptionally regulate interleukin-8 in EA.Hy926 cells under shear stress.

Cardiovascular and cerebrovascular diseases remain the leading cause of death in the world. AS (atherosclerosis) is not only an inflammatory disease in which chemokines play the main role but also a disorder that is related to blood SS (shear stress). We have investigated the action of IL-8 (interleukin-8) mRNA expression in human endothelial cells line-EA.Hy926 under SS at different intensities and duration. Expression increases with time in an intensity dependent manner. With regard to the transcriptional mechanism involved, transient transfection of the human wild-type IL-8 promoter (-162/+44)/luciferase reporter plasmid, or site mutation of one of the binding sites [AP-1 (activator protein 1) or NF-κB (nuclear factor κB)] in the IL-8 promoter region was investigated. Both AP-1 and NF-κB were essential for SS-activated transcription, with the cells responding to NF-κB activation within minutes. After stimulated at low SS (4.20 dyne/cm2) for 30 min, the P65 subunit was translocated from the cytoplasm to nucleus for at least 60 min, while the cytoplasmic level of IκB (inhibitory κB) gradually decreased. The combined activation of NF-κB and AP-1 are the upstream regulators of low SS-induced IL-8 production in EA.Hy926 cells, which subsequently trigger an inflammatory reaction in endothelium.

Phylogeography of the endangered "eyed" turtles (genus Sacalia) and the discovery of a lineage derived from natural interspecific hybridization.

The herpetofauna of the Indomalayan bioregion of Asia suffers from severe habitat loss, unsustainable harvesting, and lack of research and conservation. Here, we investigated the range-wide phylogeography of the endangered "eyed" turtles (genus Sacalia, including the Beale's Eyed Turtle S. bealei and the Four-eyed Turtle S. quadriocellata) and discovered a natural interspecific hybrid turtle population in China. Based on phylogeny of the mitochondrial Cytochrome b gene of 101 samples in this study and public data, three major clades and six subclades were identified: S. bealei (SBE) in eastern-southern China, east S. quadriocellata in South China (northern east [SQUen] and southern east [SQUes] subclades), and west S. quadriocellata mainly in Vietnam (northern west [SQUwn], central west [SQUwc], and southern west [SQUws] subclades). We sequenced 16 nuclear DNA loci of 87 samples from SBE, SQUen, SQUes, and SQUwn subclades. Population genetic clustering analysis suggested a structure similar to the mitochondrial phylogeny, where most samples were classified into four genetic clusters corresponding to the four mtDNA subclades. However, a proportion of samples carrying SQUen mtDNA haplotypes formed an additional distinct cluster SHY. Those samples are found in the contact zone of the two species bearing mosaic and intermediate morphological characteristics. We detected an admixed ancestry in SHY from SBE and SQUen that conformed to an intrapopulation breeding scenario for at least hundreds of generations after the initial hybrid event, leading to a conclusion that SHY is a distinct and near-panmictic population derived from natural interspecific hybridization. In addition, SQUes (Hainan Island endemic) is of special concern due to significant isolation and low genetic diversity. We suggest that seven evolutionarily significant units should be recognized to facilitate appropriate conservation actions. These findings also highlight the urgent need for further herpetological research and conservation in this region.

CXCR1 and CXCR2 are novel mechano-sensors mediating laminar shear stress-induced endothelial cell migration.

The migration of endothelial cells (ECs) plays critical roles in vascular physiology and pathology. The receptors CXCR1 and CXCR2, known as G protein-coupled receptors which are essential for migratory response of ECs toward the shear stress-dependent CXCL8 (interleukin-8), are potential mechano-sensors for mechanotransduction of the hemodynamic forces. In present study, the mRNA and protein expression of CXCR1 and CXCR2 in EA.hy926 cells was detected by RT-PCR and Western blot analysis under three conditions of laminar shear stress (5.56, 10.02 and 15.27 dyn/cm(2)) respectively. Using a scratched-wound assay, the effects of CXCR1 and CXCR2 were assessed by the percentage of wound closure while CXCR1 and CXCR2 were functional blocked by the CXCL8 receptor antibodies. The results showed that the mRNA and protein expression of CXCR1 and CXCR2 was both upregulated by 5.56 dyn/cm(2) laminar shear stress, but was both downregulated by 15.27 dyn/cm(2). The wound closure was inhibited significantly while cells were treated with those antibodies in all the conditions. It was suggested that CXCR1 and CXCR2 are involved in mediating the laminar shear stress-induced EC migration. Taken together, these findings indicated that CXCR1 and CXCR2 are novel mechano-sensors mediating laminar shear stress-induced EC migration. Understanding this expanded mechanism of laminar shear stress-induced cell migration will provide novel molecular targets for therapeutic intervention in cancer and cardiovascular diseases.

A comparative study of fluctuating asymmetry in Chinese families with nonsyndromic cleft palate.

OBJECTIVE: To compare the asymmetry displayed by Chinese patients with nonsyndromic cleft palate (NSCP), their unaffected parents, and a control population. METHOD: With rigorous inclusion criteria, a total number of 675 individuals with NSCP, 675 parental pairs of these patients, and 650 control individuals were involved in this case-control study. Size-adjusted fluctuating asymmetry (FA) scores were calculated by data on 10 variables. Analysis of variance was used for a three-way comparison of patients/gender-matched parents/gender-matched controls. RESULTS: A significant increase in FA for ear length (p<.05) was noted in NSCP patients when compared with their gender-matched parents. A significant increase in FA for ear length and palpebral fissure width (p<.05) was observed in NSCP patients when compared with the gender-matched control population. A significant increase in FA for palpebral fissure width (p<.05) was detected in parents of NSCP patients when compared with a gender-matched control population. CONCLUSION: Our results indicated that, when compared with a gender-matched control population, patients with NSCP show significantly increased FA in both ear length and palpebral fissure width, but the parents of patients with NSCP show significantly increased FA only in palpebral fissure width. In general, these characteristics seem to be more distinct in male individuals.

Discovery of first active breeding den of Chinese mountain cat ( Felis bieti).

In mid-September 2018, during a field survey in Chiat'ung, Sanjiangyuan (Three-River-Source) Region, Tibetan Plateau, China, we discovered the first active breeding den of the Chinese mountain cat (Felis bieti), inhabited by one adult female and two kittens. Based on fieldwork over the following months, five breeding dens were discovered, and 33 sightings were recorded. In addition, at least five individuals were confirmed to inhabit this overlooked region, and much previously unknown information concerning this cat species and its ecology was revealed for the first time.

Osteogenic effects of D+beta-3,4-dihydroxyphenyl lactic acid (salvianic acid A, SAA) on osteoblasts and bone marrow stromal cells of intact and prednisone-treated rats.

AIM: Previous studies have shown that D(+)beta-3,4-dihydroxyphenyl lactic acid (salvianic acid A, SAA) has anabolic effects on prednisone (GC)-induced osteoporosis in rats. The current study aims to investigate the molecular mechanism of SAA's impact on osteogenesis and adipogenesis in bone marrow stromal cells in intact and GC-treated rats. METHODS: For in vitro study, newborn rat calvaria osteoblasts (rOBs) and rat bone marrow stromal cells (rMSCs) were isolated, identified and cultured with SAA at different concentrations to evaluate SAA's influence on osteogenesis and adipogenesis. In addition, 3-month-old Sprague-Dawley (SD) male rats were treated with distilled water, prednisone alone (3.0 mgxkg(-1)xd(-1)) or prednisone (3.0 mgxkg(-1)xd(-1)) and SAA (25 mgxkg(-1)xd(-1)) for 45 d. At the end point, the different groups of rMSCs were isolated by density-gradient centrifugation and cultured. RESULTS: (1) At 0.1-10.0 mg/L, SAA increased ALP activity, type I collagen (Coll-I) mRNA and OPG mRNA expression and stimulated nodule mineralization of rOBs. SAA (0.5 mg/L) also significantly increased the ALP activity of rMSCs without a need for osteogenesis-inducing medium. At 5.0 mg/L, SAA decreased the number of adipocytes with less lipid droplet formation from the rMSCs, which typically undergo adipocyte induction. (2) Coll-I expression was markedly decreased, whereas lipoprotein lipase (LPL) mRNA expression increased by 98% when compared with the first generation of rMSCs in GC-treated rats. The SAA-treated rats demonstrated an over 2-fold increase in Coll-I expression when compared with intact rats and further showed a significant decrease in LPL expression when compared with GC-treated rats. When rMSCs were co-cultured with SAA (0.5 mg/L) in vitro, SAA did not affect Coll-I and LPL gene expression in intact rats but significantly increased Coll-I and decreased LPL gene expression in GC-treated rats. CONCLUSION: SAA protected bone from GC-induced bone marrow impairment by stimulating osteogenesis and depressing adipogenesis in bone marrow stromal cells both in vivo and in vitro. The data indicated that aqueous extract of Salvia miltiorrhiza, which include SAA, may serve as an active anabolic agent and a useful therapeutic strategy for the treatment of GC-associated osteoporosis.

[1H-NMR-based metabonomics analysis of plasma from osteoporotic rats induced by ovariectomy].

OBJECTIVE: To investigate the application of metabonomics in research of osteoporosis, through detecting change of the endogenous metabolites in plasma from osteoporotic rats by ovariectomy. METHODS: Six old-months female SD rats were randomly divided into sham and OVX group. Fifth month after ovariectomy, plasma were collected from both groups, respectively. The metabolic profiles were investigated using 1H-NMR spectroscopy of plsama combined with pattern recognition techniques, including principal component analysis (PCA) and partial least squares-discriminant analysis (PLS-DA). RESULTS: The PCA PLS-DA plots of the plasma samples presented marked clustering between sham group and OVX group. Compared to sham group, the level of low molecular metabolites such as lactate, acetone and ethonal were higer, glucose, choline/phosphatidylcholine (Cho/PC), alanine (Ala), high density lipoprotein/low density lipoprotein (HDL/LDL), very low density lipoprotein/low density lipoprotein, fatty acid and glucose were lower. CONCLUSION: Obvious changes in metabonomics of plasma from osteoporotic rats were observed.

Cyclic stretching promotes collagen synthesis and affects F-actin distribution in rat mesenchymal stem cells.

Recent studies have shown effects of mechanical environment on bone marrow mesenchymal stem cells (BMSC). In order to examine how BMSC and their cytoskeleton respond to mechanical stimulation, we investigated their collagen synthesis and F-actin expression. Rat BMSC were harvested from adult rats and cultured to passage 4. Then the cells were seeded onto a silicone membrane loaded with an uniaxial cyclic stretching (10%, 1 Hz) during 3, 6, 12, 24 and 36 h. The levels of collagen type I and III before and after stretching were analyzed by immunocytochemistry, and the F-actin in cytoplasm was observed by confocal microscopy. Immunocytochemistry results showed that the stretching enhanced the synthesis of collagen types I and III in BMSC after 24 h stimulation. However, a decrease in fluorescence density of F-actin was observed after the stretching in a time dependent manner. In addition, the F-actin filaments seemed much thinner than those of static cells. These results indicated that the cyclic stretching favored the synthesis of collagen types I and III, but decreased the amount of F-actin in the BMSC.

[1,25 (OH), dihydroxyvitamin D3 induces the formation of osteoclasts from mononuclear cells of rat marrow].

OBJECTIVE: To investigate the effect of 1,25 (OH)2 dihydroxyvitamin D3 on the generation of osteoclasts from mononuclear cells of adult rats. METHODS: With density gradient centrifugation, the mononuclear cells were isolated from rat bone marrow and cultured in the alpha-MEM with 10(-8) mol/L 1,25 (OH)2 dihydroxyvitamin D3. The induced cells were fixed and stained with tartrate-resistant acid phosphatase (TRAP). The bone resorption pits were examined by scanning electron microscope, and the morphology of osteoclasts were examined with inverted phase contrast microscope. RESULTS: The TRAP+ multinucleated cells could be observed on the seventh culturing day of mononuclear cell group. The number of TRAP+ multinucleated cells went up to a peak on the fourteenth culturing day, and then began to decrease on the twenty-first culturing day. The number of osteoclasts induced from mononuclear cell group was more than that from bone marrow group (P < 0.05) when it was during the fourteenth culturing day to the twenty-third culturing day. The number of bone resorption pits in the mononuclear cell group was much more than that in the bone marrow group (P < 0.05) when it was in period from the tenth culturing day to the twenty-third culturing day. The number of osteoclasts induced from mononuclear cell group could keep the peak value of lasting 7 days, but that induced from bone marrow group could only last its peak value for 3 days. CONCLUSION: The method with 1,25(OH)2 dihydroxyvitamin D3 inducing the formation of osteoclasts from the marrow mononuclear cells is better than that from the whole bone marrow.

[Transcriptional activation of interleukin-8 gene induced by shear stress in human umbilical vein endothelial cells].

OBJECTIVE: To examine the transcriptional activation of IL-8 gene induced by 4.2 dyne/cm2 shear stress in human vascular endothelial cells. METHODS: The one-step RT-PCR was used for detection of IL-8 mRNAs expression in human umbilical vein endothelial cells (HUVECs) after shear stress for 0.5, 1, 2 hours. To construct IL-8 green fluorescent protein reporter gene plasmid pEGFP1-IL8USCS. The endothelial cells were transfected with the pEGFP1-IL8USCS, and stimulated with 4.2 dyne/cm2 shear stress for 3 hours. The green fluorescent protein expression was analyzed by flow cytometry. NF-kappaB nuclear translocation was observed by immunocytofluorescent staining in HUVECs stimulated by shear stress for 0.5, 1, 1.5, 2 hours. Western blotting was used to examine kappaB phosphorylation and degradation after shear stress for 10, 20, 30, 60 minutes respectively. RESULTS: The results of RT-PCR showed that low laminar shear stress could induce IL-8 mRNA expression in HUVECs, its increased effect was time-dependent. Flow cytometric analysis showed that when exposed to 4.2 dyne/cm2 shear stress for 3 hours, there was a marked increase in the green fluorescent protein expression in the pEGFP1-IL8USCS-transfected cells. NF-kappaB p65 immunocytofluorescent staining of HUVECs showed that flow shear stress could induce nuclear translocation of NF-kappaB. Flow shear stress could induce IkappaB phosphorylation and degradation in HUVECs detected by Western blotting. CONCLUSION: These experiments suggested that the NF-kappaB signaling pathway would probably be involved in flow shear stress-induced IL-8 gene transcriptional activation, It may be involved in the development of atherosclerosis.

[Characteristics of porcine thoracic arteries fixed with polyepoxy compound].

OBJECTIVE: To investigate the characteristics of porcine thoracic arteries fixed with ethylene glycol diglycidyl ether (EX-810) and to provide the proper scaffold materials for tissue-engineered blood vessel. METHODS: The porcine thoracic arteries were respectively treated with 40 ml/L EX-810 and 6.25 g/L glutaraldehyde, and then they were examined with naked-eye, light microscope and scanning electron microscope. The fixation index determination, the amino acid analysis and the biomechanics test were also performed. RESULTS: The antigenicity of vascular tissues can be diminished by EX-810 through getting rid of cell in the vascular tissues or reducing the level of free amino groups in the vascular tissues. The structural integrity of vascular tissues can be preserved after treatment with EX-810. It was also found that the EX-810-fixed porcine vascular tissues appeared more similar to the natural vascular tissues in color and mechanical properties, and were more pliable than the glutaraldehyde-fixed tissues. CONCLUSION: The EX-810-fixed porcine thoracic arteries with low cytotoxicity and low antigenicity showed favorable characteristic similar to those of natural vessel, and it should be a promising material for fabricating scaffold of tissue-engineered blood vessel.

Changes of cytosolic [Ca2+]i in neutrophils in pancreatic microcirculation of rats with caerulein-induced acute pancreatitis under fluid shear stress.

AIM: To investigate the fluid shear stress induced changes of (Ca(2+))i in neutrophils in pancreatic microcirculation of experimental acute pancreatitis (AP). METHODS: Wistar rats (n = 36) were randomized into three groups. A model of AP was established by subcutaneous injection of caerulein. Low-shear 30 viscometer was used to provide steady fluid shear stress on separated neutrophils. The mean fluorescent intensity tested by flow cytometry was used as the indication of [Ca(2+)]i quantity. RESULTS: Under steady shear, cytosolic [Ca(2+)]i showed biphasic changes. The shear rate changed from low to high, [(Ca(2+)]i in different groups decreased slightly and then increased gradually to a high level (P<0.05). A close correlation was observed between the cytosolic [Ca(2+)]i level and the alteration of fluid shear stress in regional microcirculation of AP. CONCLUSION: The increase of [Ca(2+)]i is highly related to the activation of neutrophils, which contributes to neutrophil adhesion to endothelium in the early phase of AP. The effect of fluid shear stress on [Ca(2+)]i may play a crucial role in pancreatic microcirculatory failure of AP.

Effect of steady and oscillatory shear stress on F-actin content and distribution in neutrophils.

We investigated neutrophil activation, specifically F-actin content and distribution, in situations mimicking the in vivo environment using steady and oscillatory shear. Under low steady shear (<150 s(-1)) F-actin levels were decreased for both treated (n-formyl-L-methioryl-L-leucyl-L-phenylalanine (fMLP)) and untreated neutrophils. The F-actin content increased with a change to higher steady shear levels. Neutrophils show the same behavior of decreased F-actin content for oscillatory shear (26.7 s(-1)) as they did for steady shear. In both situations, the low shear levels caused a decrease in F-actin content. However, as the magnitude of the shear rate increased, cells showed a reversal to increasing F-actin content. Shear caused a decrease in F-actin in the cell cortex for both control and fMLP treated cells. Ctyochalasin B (CB), a common F-actin assembly blocker, significantly decreased F-actin content. The results indicate that neutrophils regulate their actin network based on the level and type of shear stress they encounter in the bloodstream.

[Piperazinyl estrone prevents bone loss in ovariectomized rats].

AIM: To determine the effect of piperazinyl estrone, a new estrogen derivative, on bone turnover, bone mass and uteri in ovariectomized rats. METHODS: Female Sprague-Dawley rats were ovariectomized (OVX) or sham operated (sham) at the age of 3 months and treated with estrone (E) at 0.75 mg.kg-1.d-1, or with piperazinyl estrone (P-E) at 1 or 10 mg.kg-1.d-1, orally, for 3 months. At the time of death, the uterine weight was measured. Bone histomorphometric analysis of proximal tibial metaphyses (PTM) was performed in undecalcified sections. RESULTS: Bone histomorphometric data showed that the percent trabecular area (% Tb.Ar) of OVX rats with bone high turnover was significantly decreased. The uteri were atrophied. The percent trabecular area (% Tb.Ar) of estrone treated group was increased in decreasing bone turnover manner. But the size and weight of uteri in this group were increased vs OVX group. The bone loss induced by OVX was preserved by P-E treatment, but the mechanism of maintaining bone is different from that of E-treated rats. P-E treatment in low dose did not decrease any bone formation indices, such as percent labeling perimeter, bone formation rate per bone volume (BFR/BV), except bone mineral apposition rate (MAR) compared with E-treated group, and maintained them at OVX level. The uteri were found to be in atrophy compared with the match dose (0.75 mg) of E-treated OVX rats. But rats treated with high dose of P-E showed the same change like E-treated group. CONCLUSION: The finding of this study shows that lower dosage of piperazinyl estrone has effect on preventing the bone losses in OVX rats, while the bone formation and the uterus are not affected, thus supporting the hypothesis that piperazinyl estrone has the potential to prevent postmenopausal bone loss in women with less side effects.

[Bone histomorphometry study on lumbar vertebrae microstructure of ovariectomized goats].

OBJECTIVE: To demonstrate the histomorphometric changes of postmenopausal osteoporosis (PMO) goat model after bilateral ovariectomy (OVX). METHODS: Fifteen female goats were randomly enrolled into four groups: 3 goats without any treatment (group C), 3 goats sham-operated only (group S), 4 goats 6 months after OVX (group OVX6M), 5 goats 18 months after OVX (group OVX18M). On the 21st and 9th day prior to sacrifice, tetracycline was given to them in order to label the bone for dynamic study. The first lumbar vertebrae from each goat were reserved for bone histomorphometric study. RESULTS: As compared with group C and S, the trabecular bone volume (TBV)/total tissue volume, TBV/sponge bone volume, mean trabecular plate thickness (MTPT) and mean trabecular plate density in OVX6M and OVX18M groups were significantly lower (P < 0.01, but MTPT: P < 0.05), while the mean trabecular plate space, surface/volume ratio of the trabecular bone, single labelled surfaces [Sfaces(s)], double labelled surfaces [Sfaces(d)], Sfaces (d + 1/2s), mean osteoid seam width, mineralization lag time, speed of bone formation in the tissue levela and osteoid maturation period were significantly higher (P < 0.01). CONCLUSION: In OVX goats, bone loss accelerated, resulting in destroyed bone microstructure, fasten frequency of activation and high bone turnover. Therefore, the bone resorption process exceeds over the bone formation, successfully establishing a high turnover osteoporotic metabolic model.

[Effect of aging on the ability of growth and differentiation of rat bone marrow stromal cells].

OBJECTIVE: To measure the osteogenesis and adipogenesis potentiality of rat marrow stromal cells (MSCs) derived from 3, 6, 9, 12-month-old doner rats. METHODS: Rat MSCs were induced to osteoblast or adipocyte by osteogenic inducer or adipogenic inducer. In different times, 3 and 12-month-old rat MSCs were observed by histochemistry staining; the mRNA level of type I collagen and lipoprotein lipase of 3, 6, 9, 12-month-old rat MSCs were measured by RT-PCR. RESULTS: The expression of alkaline phosphatase (ALP) of the control group and induced group of 12-month old rat MSCs was less than that of 3-month old rat MSCs after 1-week osteogenic induction. 12 days later, calcification was observed in 3-month old group. Lipid droplets occurred in the cells of 12-month old group after 2-day adipogenic induction, while these droplets occurred after 3-day or 4-day induction in 3-month old group. The mRNA level of type I collagen decreased with the increase of age. The mRNA level of lipoprotein lipase of younger rats was lower than that of older rats. Both of the changes were more significantly with the increase of the induction time. CONCLUSIONS: With the increase of age, the ability of osteogenesis of rat MSCs decreased, but the ability of adipogenesis increased.

[Effects of electric stimulation on circadian rhythm of plasma cortisone in soldiers].

OBJECTIVE: To observe the effects of electric stimulation on the circadian rhythm of plasma cortisone in soldiers. METHODS: Electric stimulation or phototherapy was respectively performed in the popliteal region (behind the knee) of the soldiers at different time points and radio immunal assay was utilized to examine the plasma cortisone concentration. RESULTS: The plasma cortisone concentration exhibited obvious circadian rhythmicity. At the 3 time points before the lowest core temperature occurred, treatments with electric stimulation or phototherapy resulted in delayed phase of circadian cortisone rhythm, while the same treatments given at the 3 time points after the lowest core temperature caused earlier arrival of the phase. No changes in the rhythm phase in response to treatments at other time points. CONCLUSION: Both of electric stimulation and phototherapy can adjust the phase of the cortisol circadian rhythmicity, and the phase curve displayed photic response to the treatments.

[Effect of titanium particles loading on the viability of mesenchymal stem cells after osteoblastic induction].

OBJECTIVE: To assess the effect of titanium particles on the proliferation of rMSCs after osteoblastic induction. METHODS: MTT-assay and Confocal Laser Scanning Microscopy are utilized to detect rMSCs' proliferation rate and morphologic variety. RESULTS: It was found that Ti particles loading suppressed the proliferation of osteogenesis behavior of rMSCs, but the down-regulation effect varied in different circle diameter, different concentration and different loading duration of Ti particles. Especially, among three different particles, the submicron Ti particles (0.9 micron) had the most suppressive effect on rMSCs. Under the same diameter condition, the inhibitory effect induced by Ti particles loading showed a manner dependent on the particles concentration and exposure duration. The reductive response from 1 g/L Ti was the earliest and most intense one to come forth. And the lower the concentration was in use, the weaker would be the reductive response. Furthermore, with the elongation of exposure to Ti particles, proliferation was steadily decreasing and its lowest level was at 32 h of exposure. CONCLUSION: These findings demonstrated that Ti particles loading could suppress the viability of rMSCs' osteoblastic differentiation in a manner dependent on the circle diameter, particles concentration, and treatment time.

[Effects of 17 beta-estradiol on the gene expression of shear stressed endothelial cells].

OBJECTIVE: To determine the protective effect of 17 beta-estradiol on endothelial cells under shear stress. METHODS: cDNA microarray technology was adopted in the analysis of gene expression of cultured human umbilical vein endothelial cells (HUVECs) that had been incubated by 17 beta-estradiol for 48 h and then exposed to low fluid shear stress (4.20 dyne/cm2) for 2 h, Normal static cultured HUVECs were selected as control. Total RNA from normal static cultured HUVECs was labeled by Cy3-dCTP, and the total RNA of HUVECs incubated by 17 beta-estradiol (10(-7) mol/L) and then exposed to low shear stress was labeled by Cy5-dCTP. The expression ratios reported are the average from the two separate experiments. RESULTS: A total of 384 genes (approximately 0.094%) exhibited differential expression. 226 genes were up-regulated and 158 genes were down-regulated. The transcription protein of up-regulated genes related to synthesis of PGI2, macrophage phagocytosis, and so on. The transcription protein of down-regulated genes related to degradation of fibrinogen, and to production of protooncogene. CONCLUSION: Estrin at the physiological concentration could protect impaired endothelial cells. Its protective effect may be related with some genes.