ABSTRACT
Objective To investigate the expression of vascular cell adhesion molecule-1 (VC.AM-1) in oxidative stress induced hypertrophic chondrocytes,in Kaschin-Beck disease (KBD) patients and in rat fed with T-2 toxin under selenium deficient conditions in order to analyze the relationship between VCAM-1 biological function and the dysregulation of chondrocyte differentiation in KBD.Methods The ATDC5 was cultured in 1％ ITS solution (10 mg/L insulin,5.5 mg/L transferrin,and 6.7 μg/L sodium selenite) for 21 days,and stimulated with 3-morpholino-sydnonimine (SIN-1,a nitric oxide [NO] donor) to obtain the oxidative stress induced hypertrophic chondrocytes.Real-time PCR was used to detect VCAM-1 mRNA in hypertrophic chondrocytes induced by different concentrations of SIN-1.The expressions of VCAM-I in articular cartilage of child and adult KBD patients and KBD animal model were determined via the immunohistochemical method,and KBD cartilage samples were obtained in KBD areas from KBD child who had died or from adults who had had surgery.Results After treatment of hypertrophic chondrocytes (ATCD5 cells) with SIN-1 (0,1,3,5 mmol/L),VCAM-1 mRNA levels (1.00 + 0.00,1.22 ± 0.20,0.71 ± 0.22,0.37 ± 0.16) were decreased in a dose-dependent manner when compared with the control group (F =27.788,P ＜ 0.05).The densities of VCAM-1 positive cells in superficial and middle zones of the articular cartilage of children KBD patients [(16.08 ± 5.20)％,(19.20 ± 9.71)％] were higher than those of control group [(0.00 ± 0.00)％,(0.00 ± 0.00)％],while that in the deep zone [(7.00 ± 4.40)％] in children KBD patients was significantly lower than that of control [(51.60 ± 20.58)％,tS/M/D=-10.972,-6.249,6.564,P ＜ 0.05].The positive cell density of VCAM-1 in the adult patients was significantly increased in the superficial zone [(7.92 ± 4.29)％ vs (3.12 ± 1.12)％] but significantly decreased in the middle zone [(17.54 ± 8.27)％ vs (31.75 ± 13.30)％] of articular cartilage when compared with that of control group (tS/D =-3.824,3.037,P ＜ 0.05).In articular cartilage of the four groups of KBD rats,the density of VCAM-1 positive cells in the superficial zone was significantly higher in low selenium diet group,T-2 toxin diet group and selenium deficient plus T-2 toxin diet group [(4.11 ± 1.90)％,(5.00 ±2.02)％,(2.78 ± 1.48)％ vs (1.89 ± 1.76)％,P ＜ 0.05].But the density of VCAM-1 positive cells in the deep zone was significantly lower in rat feed with selenium diet and selenium deficient plus T-2 toxin diet [(13.67 ± 2.45)％,(20.56 ± 7.42)％] than that of control group [(33.00 ± 12.57)％,P ＜ 0.05] in the epiphyseal cartilage of KBD rats.Conclusions The level of VCAM-1 is decreased both in the SIN-1 induced hypertrophic chondrocytes and in the deep zone of articular cartilage in KBD patients and in rat fed with T-2 toxin and selenium-deficient diets.VCAM-1 may be associated with the death of deep zone chondrocytes and differentiation disorder in cartilage.
ABSTRACT
Objective · To design and synthesize five new tropane compounds, and test their antagonistic activity against M3 receptor and inhibition activity to neutrophil elastase (NE), of which the structure-activity relationship were preliminarily investigated. Methods · The five compounds, A1-A3,B1 and C1, were prepared with 3α-hydroxy-tropane (A0) as the starting material by modifying the structure in C-3α position and N atom on the tropane skeleton. The antagonistic activity of the compounds to muscarinic M3 receptors on tracheal rings of guinea pigs was evaluated by functional assays in vitro. The hydrolysis of PGlu-Pro-Val-PNA as substrate was catalyzed by NE to get colorful nitroaniline (PNA). The NE inhibition activity of the tropane compounds was obtained by determining the absorbance [(D(405 nm)] of PNA. Results · The five new tropane compounds generated strong antagonistic activity against M3 receptors. Among them, A2 had the greatest activity [antagonistic parameter pA2(M3)=9.004], and elicited obvious inhibitory effect to NE (inhibition ratio YA2=20.29%). Conclusion · Introducing strong electron-attraction group, such as sulfuryl and hydrophobic group with large volume into C-3α position on the tropane skeleton can improve the M3 receptor antagonistic activity as well as the NE inhibition activity.
ABSTRACT
Objective To study the change of rats serum malondialdehyde (MDA) and the expression levels of 4-hydroxy acid nonene (4-HNE) and 8-hydroxy uridine (8-OHdG) of articular cartilage under low selenium (Se) and T-2 toxin poisoning,to explore oxidative damage of articular cartilage in rats.Methods Thirtytwo healthy male SD rats were divided into two groups by weight which were normal diet group and Se-deficiency group,16 rats in each group.Rats in normal diet group was fed with selenium 101.5 μg/kg diet,and rats in Sedeficiency group was fed with selenium 1.1 μg/kg diet for 30 d.Normal diet group was divided into control group and T-2 toxin group,and low selenium diet group was randomly divided into Se-deficiency group and Se-deficiency plus T-2 toxin group,8 rats in each group.After that,rats in T-2 toxin and Se-deficiency plus T-2 toxin groups were administrated intragastrically with T-2 toxin (100 mg/kg) everyday for 30 d.Rats were put to death,the left knee was taken and stained with hematoxylin-eosin and Safranin-Fast green,pathological changes of rat's knee joint cartilage were observed under light microscopy,expression levels of 8-OHdG and 4-HNE in rat's articular cartilage cells were determined by immunohistochemical method and rat's MDA content was determined by glucosinolates barbituric acid method.Results Chondronecrosis in deep zone of articular cartilage of knee joint stained with hematoxylin-eosin was seen in Se-deficient plus T-2 toxin diet group under light microscope.Significantly less Safranin-Fast green staining was observed in the cartilage of knee joints in the Se-deficient plus T-2 toxin diet group compared to the control group.Compared with control group [(3.41 ± 2.48)％,(2.28 ± 1.74)％],8-OHdG and 4-HNE in Se-deficient plus T-2 toxin group [(62.61 + 10.97)％,(75.03 ± 7.92) ％] positive expression rate increased significantly (F =16.24,18.61,all P ＜ 0.05).Comparison of serum MDA content in each group,the difference was statistically significant (F =4.32,P ＜ 0.05).The Se-deficiency group [(2.803 ± 0.163) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the contents of serum MDA were increased.The T-2 toxin group [(2.890 ± 0.453) μmol/L] was compared with control group [(1.873 ± 0.475) μmol/L] that the content of serum MDA was increased (P ＜ 0.05).The Se-deficiency plus T-2 toxin group [(3.521 ± 0.292) μmol/L] was compared with Sedeficiency group and control group that the contents of serum MDA were increased (all P ＜ 0.05).Conclusions The marker of peroxidation products are increased in articular cartilage of SD rats under the condition of Sedeficiency and T-2 toxin poisoning.The cartilage damage and chondronecrosis due to Se-deficiency and T-2 toxin poisoning are related to oxidative damage.