MicroRNAs (miRNAs) are small non-coding RNAs that contain 22 to 25 nucleotides and play important roles in post-transcriptional regulation of target genes. MiRNAs are involved in cell proliferation, differentiation, apoptosis, inflammation, and cancer development. Alveolar bone resorption is the main clinical manifestation of periodontitis. Osteoclasts are unique cells regulated by osteoblasts and inflammatory cytokines and are responsible for bone resorption in periodontitis. Recently, miRNAs have emerged as an important regulator of osteoclast differentiation and function. In this study, we review the recent research progress on the effects of miRNAs on osteoclast differentiation and function, particularly the mechanisms of miRNAs-mediated osteoclast formation and bone loss in periodontitis.
Bone Resorption ; Bone and Bones ; Cell Differentiation ; Cell Proliferation ; Humans ; MicroRNAs ; Osteoblasts ; Osteoclasts

Objective To observe the changes and its significance of the levels of serum cytokines——interleukin-(IL)1?,IL-6,tumor necrosis factor(TNF)-? and C-reactive protein(CRP) in patients with cerebral infarction(CI).Methods The serum IL-1?,IL-6 and TNF-? level were detected by radioimmunnoassay and serum CRP level by immunoturbidimetry in 30 CI patients with DM(DMCI group),30 CI patients without DM(NDMCI group),20 patients with DM(DM group) and 20 normol controls(NC group).The situation of CI patients were assessed by modified Edinburgh-Scandinavian stroke scale(ESSS).Results The serum levels of IL-1? [(0.60?0.04)ng/ml,(0.33?0.03)ng/ml,(0.30?0.02)ng/ml],IL-6 [(231.07?7.68)pg/ml,(141.34?6.50)pg/ml,(118.92?5.82) pg/ml],TNF-?[(2.70?0.11)ng/ml,(1.85?0.11)ng/ml,(1.21?0.13) ng/ml] and CRP [(7.44?0.26),g/L,(4.67?0.21)mg/L,(4.54?0.24)mg/L] in DMCI group,NDMCI group and DM group were significantly higher than those in NC group [(0.20?0.03)ng/ml,(60.99?5.98)pg/ml,(0.70?0.10) ng/ml,(3.83?0.14) mg/L](all P

OBJECTIVE: To investigate the effects of Radix notoginseng extracts drug-containing serum on the expressions of apoptosis-regulating proteins including Bax, bcl-2 and p21WAF1 in precancerous gastric cells. METHODS: The N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) transformed eternalized human gastric mucosa epithelium GES-1 cell line (MC cell) was used in vitro as a model of gastric precancerous lesion. The medicated canine serum was prepared by feeding to the adult Beagle dog with Radix notoginseng extracts and obtaining the serum after 2-hour medication. MC cells were cultured with medicated canine serum (medicated serum group) or non-medicated canine serum (normal control group) for 72 hours. Expressions of Bax, bcl-2 and p21WAF1 proteins were detected by immunocytochemical assay and the average optical density of the cells was determined by an image analysis system. RESULTS: Compared with those of the normal control group, Bax and p21WAF1 expressions in medicated serum group were significantly enhanced (P<0.01), while the expression of bcl-2 was significantly reduced (P<0.01). CONCLUSION: Radix notoginseng extracts may inhibit the proliferation and promote the apoptosis of precancerous gastric cells through altering expressions of the bcl-2, Bax and p21WAF1 genes.

OBJECTIVE: To study the apoptosis-promoting effect of the serum from Panax notoginseng extracts-fed dog on precancerous gastric cells by means of flow cytometry. METHODS: In the experiment, we adopted eternalized human gastric mucosa epithelium GES-1 cells transformed by N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) (MC cells) as the model of precancerous lesions for study in vitro. We took the serum of a dog before and at two different points of time (2 and 6 hours) after feeding the dog with Panax notoginseng extracts for experiment. The MC cells were cultured in mediums with different concentrations of the medicated serum at 2- or 6-hour point of time for 72 hours. By means of flow cytometry, we examined the apoptosis-promoting effects of the serums on the MC cells. RESULTS: The medicated serums at these 2 points of time had significant effects in promoting MC cell apoptosis. The proportions of apoptotic cells in culture mediums with medicated serums had a significant increase as compared with those in culture mediums with non-medicated serums (serum obtained before administration of extracts to the dog) under the same conditions (P<0.05). The number of MC cells in G(0)/G(1)phase was decreased (P<0.05) and that in G(2)/M phase increased (P<0.05), while no consistent changes were observed in S phase. CONCLUSION: The medicated serums obtained at the two different points of time have significant apoptosis-promoting effects on MC cells. They decrease the number of MC cells in G(0)/G(1) phase and increase the number of MC cells in G(2)/M phase. This is probably responsible for the effects of Panax notoginseng extracts in inhibiting the proliferation of MC cells and promoting its apoptosis.

OBJECTIVE: Through cell cultivation, we studied the inhibiting effects of the serum of the dog fed with Panax notoginseng extracts on precancerous gastric cells, trying to find the best time points or periods when the extracts' function was the strongest after administration of the extracts to the dog. METHODS: The experiments adopted eternalized human gastric mucosa epithelium GES-1 cells and MC cells gained from GES-1 cells transformed by N-methyl-N'-nitro-N-nitroso-guanidine (MNNG) as the model of precancerous lesions for study in vitro. We took the serum of a dog before and at different points of time after feeding the dog with Panax notoginseng extracts for experiment. By means of MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay, we examined the inhibiting effects of the serum after culturing the GES-1 and MC cells for 72 hours with different concentration (8%, 4%, 2%) of medicated serum obtained from the dog at different points of time, so as to find that, at which points of time the medicated serum obtained, it would be the most effective. RESULTS: The results showed that the GES-1 and MC cells inhibition rates of medicated serum from the points of 2-hour and 6-hour were the highest, and the culture medium containing 8% of medicated serum from these two points had prominent inhibiting effects on both kinds of cells. The GES-1 cells inhibition rate in culture medium containing 8% of medicated serum from the point of 2-hour was 70.8% (P<0.01) and that of the MC cells was 45.3% (P<0.01). The GES-1 cells inhibition rate in culture medium containing 8% of medicated serum from the point of 6-hour was 88.5%(P<0.01) and that of the MC cells was 42.4% (P<0.01). CONCLUSION: The points of time with the strongest inhibiting effects are 2 hours and 6 hours after being fed with Panax notoginseng extracts. At these two points, the serum is most effective in inhibiting the proliferation of GES-1 and MC cells.

Objective The goal of this study was to investigate the correlation between the level of serum vitamin D and bone metabolism and disease activity in ankylosing spondylitis(AS) patients,and thus to explore the role of vitamin D in bone metabolism in AS patients.Methods The serum levels of BALP,TRACP-5b,25-(OH)D3 and blood lymphocytes VDR of 80 AS patients were measured by enzyme-linked immunosorbent assay (ELISA) and compared with those of the control group.Bone mineral density (BMD)was measured by dual-energy X-ray absorptiometry (DEXA).The ESR and CRP level of AS patients were also measured.The correlation between those parameters was analyzed and evaluated.Patients were divided into normal,insufficient and deficient subgroups according to the serum 25-(OH)D3 levels for further comparison.Indepondent saimple t test,t'test andx2 test were used for statistical analysis.Results The 25-(OH)D3 of AS patients [(11.9±2.7) μg/L] was significantly lower than that of the control groups [(22.3±7.9) μg/L] (P＜0.05),while the serum levels of BALP [(3.9±2.7) μg/L] and TRACP-5b [(46±25) ng/L] of AS patients were significantly higher than those of the control group [(2.4±1.0) μg/L] (P＜0.05).According to linear correlation analysis,25-(OH)D3 was negatively correlated with CRP (r=0.324,P=0.003).The ESR,BALP,TRACP-5b in the deficient subgroup were higher than those in the normal and insufficient subgroups(P＜0.05).Conclusion The plasma 25-(OH)D3 may decrease in AS patients,and this may activate bone metabolism,results in increased morbidity of osteoporo-sis,and negatively affect disease activity.

Objective To investigate the role of RANKL/RANK/OPG system in bone metabolism of ankylosing spondylitis (AS) by detecting bone mineral density, bone metabolism factors such as osteoprotegerin (OPG), soluble receptor activator of nuclear factors-κB ligand (sRANKL) and the expression of membrane-bound (mb) RANKL in the peripheral blood T lymphocytes. Methods Bone mineral density of AS patients were measured by dual-energy X-ray absorptiometry (DEXA) and serum levels of OPG, sRANKL,tartrate resistant acid phosphatase 5b (TRACP-5b) and bone alkaline phosphatase (BALP) were determined by enzyme-linked immunosorbent assay (ELISA). The percentages of CD4+/RANKL+ and CD8+/RANKL+ in the peripheral blood were detected with flow cytometry. T-test, x2-test were used for statisical analysis. Results ① The incidence of osteopenia and osteoporosis in AS was 47% and 37% respectively. ② Serum RANKL,TRACP-5b levels and RANKL/OPG ratio were higher in AS patients than those in normal controls (P<0.05).But there was no significant difference in OPG and BALP between AS patients and normal controls. ③There were positive linear correlation between serum levels of RANKL and OPG, sRANKL and TRACP-5b, OPG and TRACP-5b in AS (P<0.01). ④ The prevalence of CD4+/RANKL+ cells in the peripheral blood of AS patients was significantly higher than that in the normal controls (P<0.05). Conclusion There is a high incidence of bone loss in AS patients. Increased bone resorbtion is the feature of bone metabolism in AS.RANKL/RANK/OPG system may play an important role. The imbalance of RANKL/RANK/OPG system may be one of the bone loss mechanisms of AS. CD4 + T lymphocyte may play an important role in osteoclasts differentiation and bone resorption in AS by up-regulating the expression of RANKL.

Objective To investigate the incidence of osteoporosis (OP) in patients with ankylosing spondylitis and the relationship between OP and the clinical data. Methods Serum levels of bone alkaline phosphatase (BALP) and tartrate resistant acid phosphatase 5b (TRACP5b) were detected by enzyme linked immunosorbent assay ( ELISA ) in 60 cases with ankylosing spondylitis, and it was compared with normal controls. Bone mineral density (BMD) was measured through dual-energy X-ray absorptiometry ( DXA), including lumbar ( L2 - L4), bilateral femoral neck and greater trochanter. Some clinical data was collected and analyzed at the same time. Results The incidence of OP in AS patients was 35%, and the incidence of OP in the femoral proximal end was higher than that in lumbar. Compared with normal controls[ ( 1.06 ±0. 18 )U/L ], the levels of serum TRACP5b in AS[ (1.31 ± 0. 82 )U/L] patients was significantly higher ( P <0. 05 ). The levels of serum BLAP in OP combined AS group[ ( 21.65 ± 5.41 ) U/L]were significantly lower than non-OP group[ (32. 37 ± 16. 5 ) U/L] ( P <0. 05 ). The disease duration was negatively correlated with the BMD of femoral neck ( P < 0. 01 ). Conclusions There was higher incidence of OP in AS patients, which were related with the abnormality of bone metabolism and the disease duration.Multiple factors participated in the regulation of bone metabolism of AS.

Objective To study the receptors signaling of prostaglandin E2 on the differentiation of regulatory T (Treg) cells and Th17 cells.Methods The expression of prostaglandin E2 receptors (EP1/EP2/EP3/EP4) on the MACS-purified CD4+CD62L+ T (Th0) cells was analyzed by flow cytometry and reverse transcription polymerase chain reaction (RT-PCR).The quantity of CD25+Foxp3+ cells was examined by flow cytometry,the expression of FoxP3 mRNA and RORγt mRNA were detected using real-time RT-PCR,the level of IL-17 in the culture supernatants was detected by enzyme-linked immunosorbent assay (ELISA).ANOVA,LSD-t,Dunnett T3 were used for statistical analysis.Results EP1,EP2,EP3,EP4 were expressed on Th0 cells at different levels,and EP2 [(89.7±9.1)％] had the strongest expression.PGE2 [(3.0± 2.2) ％],EP2 agonist [(4.5± 1.0) ％] and EP4 agonist [(8.8 ±2.5) ％] decreased the quantity of CD25 +Foxp3 + cells compared with the control group [(28.6±6.8)％] (t=7.156,P=0.021; t=6.958,P=0.032; t=5.359,P=0.044).PGE2(0.210±0.020),EP1 agonist (0.833±0.045),EP2 agonist (0.227±0.025) and EP4 agonist (0.450±0.060) decreased the expression of Foxp3 mRNA compared with the control group (1.000) (t=23.817,t=5.026,t=23.313,t=16.581; all P=0.000).PGE2 [(22±6)pg/ml],EP2 agonist [(24±5)pg/ml]and EP4 agonist [(207±19) pg/ml] decreased the secretion of IL-17 compared with the control group [(678±87) pg/ml] (t=14.925,P=0.004; t=14.873,P=0.004; t=10.480,P=0.008).PGE2 (0.141±0.027),EP1 agonist (0.869±0.033),EP2 agonist (0.176±0.029) and EP4 agonist(0.371±0.042) decreased the expression of RORγt mRNA compared with the control group (1.000) (t=34.046,t=5.184,t=32.673,t=24.962,all P=0.000).Conclusion EP1,EP2,EP3,EP4 receptors are expressed on CD4+CD62L+ T (Th0) cells at different levels.Prostaglandin E2 inhibits the differentiation of Treg cells and Th17 cells via the EP2 and EP4 receptors signaling.

Objective To study the effects of EP4 and EP2 antagonists on the differentiation of Treg/ Th17 cells and disease progression in mice of collagen-induced arthritis (CIA) model.Methods DBA/1 mice wereimmunized subcutaneously twice at the root of the tail with type Ⅱ collagen emulsified in Freund's complete adjuvant.EP2 and EP4 antagonist therapies were intraperitoneally administrated for 14 consecutive days after the second immunization.Clinical signs,histological manifestation,serum interleukin (IL)-17 and quantity of CD4+CD25+Foxp3+ Treg cells were determined.ANOVA and t-test were used for statistical analysis.Results Clinical signs of the disease appeared on day 27 and peaked on day 35 after the first immunization.The quantity of CD4+CD25+Foxp3+ Treg cells in spleens [(1.67±0.15)％] and draining inguinal lymph nodes [(3.30±0.36)％] isolated from CIA mice were significantly lower than those of normal DBA/1 mice [(2.77±0.45)％ and (4.73 ±0.45)％ respectively,P＜0.05].Serum IL-17 level of CIA mice [(27±7) pg/ml] was significantly higher than that of normal DBA/1 mice [(14±4) pg/ml,P＜0.05].Intra-peritoneal injection of EP4 but not EP2 antagonist to CIA mice decreased paw edema and swelling,and alleviated the histological manifestations (1.8±1.0 vs 3.5±0.6,P＜0.05) on day 35 after the first immunization.The percentages of CD4+CD25+Foxp3+ Treg cells in both inguinal lymph nodes [(4.20±0.32)％] and spleens [(2.63±0.40)％] were significantly higher in EP4 antagonist-treated but not EP2 antagonist-treated CIA mice compared with CIA mice group [(3.30±0.36)％ and (1.67±0.15)％ respectively,P＜0.05].The level of serum IL-17 was significantly lower in EP4 antagonist-treated [(15±7) pg/ml] but not EP2 antagonist-treated CIA mice compared with CIA mice group [(27±7) pg/ml,P＜0.05].Conclusion EP4 antagonist therapy alleviates clinical symptoms of CIA,improves the histological manifestations,decreases the serum IL-17 level and increases the percentages of CD4+CD25+Foxp3+ Treg cells in both spleens and draining inguinal lymph nodes,so targeting EP4 receptor may be a new possible therapeutic possibility in the prevention and treatment of rheumatoid arthritis.