The effect of spinal cord injury on the expression of TGF-β and TNF-α in rat articular cartilage

Objective： To observe the expression of TGF-β and TNF-α in the spinal cord injured rat model and discuss the significance of the articular cartilage metabolism. Methods： 36 SD female rats were randomly divided into 2 groups： Rats models of spinal cord injury were implemented by Allen method. T10 laminectomy was performed in the control group. Both groups of rats were killed respectively in 1w, 3w and 6w. Hematoxylin-eosin stain was given to each slice in the model group and control group. Immunohistochemical stain was applied by using ABC method in the expression of TGF-β and TNF-α. Those expressed level were performed in image analysis and statistics process. Results： TGF-β and TNF-α were mainly distributed on the surface layer of the articular cartilage, with a weak expression in control group. The expression of TNF-α in the model group was more significant than that in the control group in the lw, and still remained an evident difference with that in control group until the 6w（P 〈 0.05）. TGF-β expression of the model group had no remarkable difference with the control group in the lw （P 〉 0.05） and prominently became stronger at 6w（P 〈 0.05）. Conclusion： The expression of TNF-α occurred early in the development of spinal cord injury, and the expression of TGF-β became stronger with the revival of spinal neural function. Both expressions were strengthened in articular cartilage in the 3rd week.     

Expression of miRNA-140 in Chondrocytes and Synovial Fluid of Knee Joints in Patients with Osteoarthritis

Objective To investigate the expression of miRNA-140 in chondrocytes and synovial fluid of osteoarthritis (OA) patients, and explore the relationship between the miRNA-140 expression and OA severity.
Methods This study enrolled 30 OA patients who underwent total knee arthroplasty for chondrocytes sampling and 30 OA patients who underwent intra-articular injection for synovial fluid sampling. All OA patients were grouped intomild [Kellgren and Lawrence (KL) grade 1-2], moderate (KL grade 3) and severe (KL grade 4), with 10 in each subgroups for each sampling purposes. 7 non-OA patients and 10 patients with knee injury were collected for cartilage and synovial fluid sampling respectively as control groups. Chondrocytes were isolated from the cartilage tissue and culturedin vitro. Quantitative real time PCR for miRNA-140 in chondrocytes and synovial fluid were performed, and the U6 snRNA was used as internal control. The expression difference of miRNA-140 among groups and correlation between the expression and the KL grade of OA were analysed using one-way ANOVA and Spearman test respectively.
Results The expression of miRNA-140 in chondrocytes of knees in OA patients was reduced than that in normal knees, and the between-group difference was statistically significant (F=305.464,P<0.001). miRNA-140 could be detected in synovial fluid of both normal knees and OA knees, its relative expression level was reduced in synovial fluid of OA group compared with normal group, and the between-group difference was statistically significant as well (F=314.245,P<0.001). The relative expression level of miRNA-140 in both chondrocytes and synovial fluid were negatively correlated with the KL grade of OA(r=-0.969,P<0.001;r=-0.970,P<0.001).
Conclusion miRNA-140 could be detected in chondrocytes and synovial fluid of OA patients, and its expression was negatively correlated with the severity of OA.     

Effects of cytokines, growth factors and drugs on matrix metalloproteinases activities of osteoarthritic chondrocytes and synoviocytes

Objective: To evaluate the effects of some cytokines, TGF-β1 and drugs on matrix metalloproteinases (MMPs) activities in culture medium of arthritic chondrocytes and synoviocytes. Methods: The chondrocyte and synoviocyte monolayers isolated from the cartilages and synovial fluids in 10 knee OA patients were treated with IL-1β TGF-β1, TNF-α, diclofenac acid, dexamethasone or doxycycline individually and together for 72 h. Zymography was used to determine the activities of MMP-2 and -9. Results: The chondrocyte monolayers produced MMP-2 and -9, while the synoviocytes only produced MMP-2. The MMP-9 activity was markedly enhanced by IL-1β TNF-α and diclofenac. IL-1β was the most effective stimulus, and had synergistic effect with TNF-α or diclifenac. MMP-2 activity was not affected. Doxcycline, TGF-β1 and dexamethasone could depress the activities of MMP-9 and MMP-2, and antagonize the enhancing effect of IL-1β TNF-α or diclofenac. Conclusion: IL-1β and TNF-α may play important roles degrading OA cartilage, while TGF-β1 and doxycycline may be protective factors.     

The effect of spinal cord injury on the expression of TGF-β and TNF-α in rat articular cartilage

Objective: To observe the expression of TGF-β and TNF-α in the spinal cord injured rat model and discuss the significance of the articular cartilage metabolism. Methods: 36 SD female rats were randomly divided into 2 groups: Rats models of spinal cord injury were implemented by Allen method. T10 laminectomy was performed in the control group. Both groups of rats were killed respectively in 1w, 3w and 6w. Hematoxylin-eosin stain was given to each slice in the model group and control group. Immunohistochemical stain was applied by using ABC method in the expression of TGF-β and TNF-α. Those expressed level were performed in image analysis and statistics process. Results: TGF-β and TNF-α were mainly distributed on the surface layer of the articular cartilage, with a weak expression in control group. The expression of TNF-α in the model group was more significant than that in the control group in the 1w, and still remained an evident difference with that in control group until the 6w(P ＜ 0.05). TGF-β expression of the model group had no remarkable difference with the control group in the lw (P ＞ 0.05) and prominently became stronger at 6w(P ＜ 0.05). Conclusion: The expression of TNF-o occurred early in the development of spinal cord injury, and the expression of TGF-β became stronger with the revival of spinal neural function. Both expressions were strengthened in articular cartilage in the 3rd week.     

Dynamic Expression of Tumor Necrosis Factor-α and Vascular Endothelial Growth Factor in Rat Model of Pulmonary Emphysema Induced by Smoke Exposure

In order to explore the roles of tumor necrosis factor-α(TNF-α) and vascular endothelial growth factor(VEGF) in the pathogenesis of pulmonary emphysema,male Wistar rats were randomized into group A1,group A2.5 and group A4,each with smoke exposure for 1 month,2.5 months or 4 months,respectively.Group B1,group B2.5 and group B4 were used as non smoking controls at corresponding time points.TNF-α in bronchoalveolar lavage fluid(BALF) and expression of VEGF in lung tissue was determined by ELISA or by SABC immunohistochemistry assay either.Lung slices were stained with hematoxylin and eosin(HE).Results showed that in animal with smoke exposure the mean linear interceptor(Lm),an index of pulmonary emphysema and the content of TNF-α in BALF increased gradually,on contrary,the expression of VEGF in lung tissue decreased(P<0.05).This phenomenon was not obvious in animals without smoke exposure.Lm was negatively correlated to the VEGF expression(γ=-0.81,P<0.01) and positively correlated to TNF-α concentration(γ = 0.52,P<0.004),which implies that smoke exposure decreased the expression of VEGF and increased the expression of TNF-α.It is plausible to speculate that the imbalance of TNF-α and VEGF may play an important role in the pathogenesis of smoke-induced pulmonary emphysema.     

Effect of Wumeiwan on Cytokines TNF-α, IL-6, IL-8, IL-10 and Expression of NF-κBp65 in Rats with Ulcerative Colitis

The effects of Wumeiwan （WMW） on TNF-α, IL-6, IL-8, IL-10 and NF-κBp65 in rats with ulcerative colitis （UC） were investigated, the curative effectiveness of WMW vs salicylazosulfapyridine （SASP） was compared, and the action mechanism was analyzed. Fifty-Six Sprague-Dawley （SD） rats were randomly divided into four groups （n=14 in each group, with equal ratio of male and female）： normal control group, model group, SASP group, and WMW group. Except normal control group, the rat UC models in the remaining three groups were established using the method of 2.4-dinitrochlorobenzene （DNCB） immunization and acetic acid local enema. The rats in model group, SASP group, and WMW group were treated with distilled water, SASP, and WMW respectively. The changes in the symptoms and signs were observed, and levels of IL-6, IL-8, TNF-α, IL-10 and the expression of NF-κBp65 in the colonic tissues were statistically analyzed. The results showed that the levels of IL-6, IL-8, and TNF-α were significantly increased （P〈0.01）, while those of IL-10 significantly reduced （P〈0.01） after establishment of rat UC models as compared with normal control group. The levels of IL-6, IL-8, and TNF-α were obviously lower, but the level of IL-10 was obviously higher in WMW and SASP groups than those in model group （P〈0.05）. The levels of IL-6, IL-8, and TNF-α were lower, while the level oflL-10 was higher in WMW group than in SASP group. NF-κBp65 was expressed negatively or weakly in normal colonic tissues. The positive expression rate of NF-κBp65 in WMW group and SASP group was obviously lower than in model group （P〈0.01）, and there was significant difference between WMW group and SASP group （P〈0.05）. It was concluded that rat UC model was established successfully. WMW could up-regulate the expression of IL-10, down-regulate the expression of TNF-α, IL-6, IL-8, and inhibit the NF-κBp65 activity to adjust immune function, indicating WMW had better curative effects on UC in rats.     

Effect of Electro-acupuncture on Rat Joint Pathomorpnology of Chronic Adjuvant Arthritis Model

Objective:To study the effect of electro-acupuncture (EA) on pathomorphological changes of joints in rat model of chronic adjuvant arthritis. Methods: The rat chronic adjuvant arthritis model was established by subcutaneous injection of 0.1 ml of complete Freund's adjuvant to the left hind sole. Forty Wistar rats were randomly divided into the model group, the low frequency (2 Hz) EA group, the high frequency EA (100 Hz) group and the body acupuncture group. After being modeled except the model group, the other three groups were treated with EA or body acupuncture in Yanglingquan points (bilateral) for 3 weeks, the left ankle joints and metatarsal joints of rats were taken for pathological examination by fixing with 10% formalin and embedding in paraffin, sectioning and staining with HE. Results: Obvious inflammatory cell infiltration, loosened synovial tissue, damage of articular cartilage and proliferation of synovial cells and granulation tissue were observed in the sections of joints in model rats.     

Effect of ARB on Expression of CD68 and MCP-1 in Adipose Tissue of Rats on Long-term High Fat Diet

In adipose tissue of rats on long-term high fat diet, the inflammatory changes the roles of angiotensin receptor blocker （ARB） in pimelitis and insulin resistance （IR） were observed. LR rat model was established by feeding high calorie and high fat diet. The change in insulin sensitivity was detected by euglycemic-hyperinsulinemic clamp technique 8 weeks after intervention by valsartan. The expression levels of CD68 and MCP-1 mRNA and proteins in adipose tissue were examined by RT-PCR and immunohistochemistry respectively. The parameters of blood glucose, insulin and blood lipid were analyzed. The results showed that in high fat diet group intra-abdominal obesity developed the content of visceral fat and the number of inflammatory cells in local adipose tissue were significantly increased （P〈0.01）, the levels of serum triglyceride, free fatty acids and fasting serum insulin were markedly increased, the insulin sensitivity was significantly lowered （P〈0.01）, and the expression of CD68 and MCP-1 was significantly increased as compared with control group （P〈0.01）. In ARB interventional group, the content of visceral fat, the number of inflammatory cells and the ex- pression of CD68 and MCP-1 in local adipose tissue were significantly reduced （all P〈0.01）, but the insulin sensitivity was significantly enhanced （P〈0.01） as compared with high fat diet group. There were pimelitis and IR in rats with obesity induced by long-term high calorie and high fat diet. The ARB can significantly inhibit the infiltration of macrophages and the expression of MCP-1 in adipose tissue, thereby attenuating the inflammation and improving LR in rats.     

Effects of aerosolized ketamine on the level of nitric oxide and nitric oxide synthetase in the lung tissue of rat with asthma

Objective： To explore the effects of aerosolized ketamine on the level of nitric oxide and nitric oxide synthetase in the lung tissue in rat asthma model. Methods： Forty SD rats were randomly assigned to five groups： control group （group N）, asthma model group （group A）, two pretreated groups of different concentrations of ketamine （group K1, K2） and dexamethasone group（group D） with eight rats in each group. The rats in group A were sensitized by injection of ovalbumin （OA） together with aluminum hydroxide and bordetella pertussis as adjuvants. Two weeks after the sensitization, aerosolized OA was used to cause asthma. The rats in group K1 and K2 were sensitized with OA as group A , and then exposed to aerosol of ketamine , with the concentration of 25 g/L and 50 g/L respectively. Before using aerosolized OA,the rats in group D were exposed to aerosol of 0.01% dexamethasone .The level of NO2^-/NO3^- in lung tissues, inducible nitric oxide synthetase（iNOS） and constitute nitric oxide synthetase（cNOS） was measured in all groups. Results： The level of NO2^-/NO3^- and the activity of iNOS in lung tissues in group A were signiticantly higher than those in the other groups. The iNOS activity and the level of NO2^-/NO3 ^- in lung tissues were highly positively correlated. Conclusion： NO can induce airway hyperreactivity that may worsen asthma. Aerosolized ketamine can decrease the iNOS expression and reduce the level of NO in the lung tissue in rat asthma model.     

Effects of Triptolide on the Expression and Activity of NF-κB in Synovium of Collagen-induced Arthritis Rats

Summary： The expression and activity of NF-kB in the synovium of collagen-induced arthritis （CIA） rats was detected in order to investigate the possible therapeutic effects of triptolide on rheumatoid arthritis （RA）. The experimental Wistar rat model of CIA was set up by intradermal injection of emulsion of bovine collagen 11 and the successful rate of setting-up models was evaluated by arthritis index （AI）. Rats were grouped randomly into three groups： normal, model and treatment group. The expression of TNF-α and IL-6 in synovial fluid was detected by ELISA, and the expression and activity of NF kB in synovium by immunohistochemistry method and by electrophoretic mobility shift assay （EMSA） respectively. As compared with normal group, the expression of TNF a and IL-6 in synovia （P〈0. 05）, and the expression and activity of NF-kB （P〈0.05） in synovium were increased in model group. There was statistical difference in above-mentioned indexes between model group and treatment group. Triptolide may play a protective role in IRA via downregulating the expression and activity of NF-kB in synovium.     

Role of Nuclear Transcription Factor-κB in Endotoxin-induced Shock in Rats

To investigate the role of NF-κB in endotoxic shock in rats. the model of endotoxinshock rats was induced by intravenous infusion of lipopolysaccharidc (LPS). 1 h. 2 h. 4 h and 6 h after LPS injection, the activation of NF-κB in blood mononuclear cells and the content of TNF-α and IL-6 in plasma was detected by enzyme-linked immunoadsordent assay (ELISA). The level of mean arterial pressure (MAP) and the histopathological changes of lung and liver were also observed. The activation of NF-κB in mononuclear cells increased 1 h after LPS injection and reached its peak 2 h after the injection, and its level was higher than that of normal group. The level of TNF-α was increased 1 h after the infusion and peaked 2 h after the injection, and its level was higher than that of normal group after LPS infusion. The content of IL-6 increased gradually with time. the IL-6 level was higher than that of normal group after LPS injection. MAP was decreased gradually with time and its level was lower than that of normal group after LPS injection. Pathological examination showed that endotoxic shock could cause pulmonary alveolar hemorrhage, edema and infiltration of inflammatory cell in lung tissue and congestion, edema, capillary dilation and inflammatory cell infiltration in liver tissue. It is concluded that NF-κB can up-regulate the expression of TNF-α and IL-6 in plasma and play an important role in endotoxin induced shock in rats.     

Effect of oleic acid-induced acute lung injury and conventional mechanical ventilation on renal function in piglets

Background Animal models that demonstrate changes of renal function in response to acute lung injury (ALI) and mechanical ventilation (MV) are few. The present study was performed to examine the effect of ALI induced by oleic acid (OA) in combination with conventional MV strategy on renal function in piglets.

Methods Twelve Chinese mini-piglets were randomly divided into two groups: the OA group (n=6), animals were ventilated with a conventional MV strategy of 12 ml/kg and suffered an ALI induced by administration of OA, and the control group (n=6), animals were ventilated with a protective MV strategy of 6 ml/kg and received the same amount of sterile saline.

Results Six hours after OA injection a severe lung injury and a mild-moderate degree of renal histopathological injury were seen, while no apparent histological abnormalities were observed in the control group. Although we observed an increase in the plasma concentrations of creatinine and urea after ALI, there was no significant difference compared with the control group. Plasma concentrations of neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C increased (5.6±1.3) and (7.4±1.5) times in the OA group compared to baseline values, and were significantly higher than the values in the control group. OA injection in combination with conventional MV strategy resulted in a dramatic aggravation of hemodynamic and blood gas exchange parameters, while these parameters remained stable during the experiment in the control group. The plasma expression of TNF-α and IL-6 in the OA group were significantly higher than that in the control group. Compared with high expression in the lung and renal tissue in the OA group, TNF-α and IL-6 were too low to be detected in the lung and renal tissue in the control group.

Conclusions OA injection in combination with conventional MV strategy not only resulted in a severe lung injury but also an apparent renal injury. The potential mechanisms involved a cytokine response of TNF-α and IL-6 in plasma, lung and renal tissues.

     

Expression of cyclooxygenase-2 and its pathogenic effects in nonalcoholic fatty liver disease

Objective:To investigate the expression of cyclooxygenase-2 and its pathological effect in the experimental nonalcoholic fatty liver of rats,and to explore its possible mechanism.Methods:The rat NAFLD model was established by giving a fat-enriched diet.The blood samples were obtained form abdominal aorta and the levels of serum ALT,AST and IL-1,changes in the hepatic tissue 6-k-PGF1α TXB2 were measured.The expression level of COX-2 in rats livers were assayed by immunohistochemistry,RT-PCR and Western-blot.Results:Light microscope analysis revealed that hepatocytes were injured in the model group and slightly in the treatment group.The levels of serum TXB2 and IL-1 in the fatty liver rats were increased.Compared with the model group,the IL-1 and TXB2 increased significantly(P < 0.05),on the contrary,compared with the normal group,the hepatic tissue 6-Keto-prostagland decreased significantly in the model group(P < 0.05),the treatment group also increased but P > 0.05.There was no positive expression of COX-2 in hepatic tissue of normal rats.In the model group,there was positive expression of COX-2 antigen and the number of COX positive cells progressively increased at 4,8,12 wks.The intensity of expression of COX-2 had significantly increased(P < 0.05)and the intensity of COX-2 expression in the treated group decreased remarkably compared with the model group(P < 0.05).The expression of COX-2 mRNA and the level of COX-2 protein were significantly stronger in the liver of model rats compared with normal rats,and significantly weaker in treated rats,than in 8W and 12W model rats(P < 0.05).Conclusion:The increase of COX-2 expression in NAFLD is closely associated with the severity of liver inflammation and damage.COX-2 may play an important role in the progression of rat NAFLD,and the expression of COX-2 mRNA is downregulated by cyclooxygenase-2 inhibitor,which can depress the oxidative stress and control inflammatory response efficiently.     

Upregulation of TNF-α mRNA in hepatic fibrosis rats induced by dimethylnitrosamine

Objective：To observe the expression level of TNF-α mRNA in rats with hepatic fibrosis induced by dimethylnitrosamine （DMN） and to explore its relationship with collagen metabolism and its diagnostic value for hepatic fibrosis.Methods： Twenty-five male Wistar rats were randomly divided into normal control group （n=10） and model group （n=15）. Model rats were induced by DMN for 4 weeks and at final stage were executed. TNF-α mRNA were detected by RT-PCR and the inflammatory necrosis and collagen deposition in hepatic tissue were observed by HE stain and Sirius red stain. The liver functions were determined by automatic biochemical analytic device. The serum marks of liver fibrosis, such as HA, LN and Ⅳ-C were measured with ELISA and RIA. Results： In this study, the rat model of liver fibrosis induced by DMN was successfully constructed. RT-PCR reveals that TNF-α mRNA expression in control group is lower than that of model group. The liver functions of model group were impaired compared with those of the control group （P〈0.01）. Semi-quantitive analysis revealed that TNF-α/β-actin of normal rats was 0.39±0.12, while 0.93±0.05 of model rats. The concentration of HA （434.44±98.81 vs 252.9±26.59 ng/ml, P〈0.01）, LN （70.67±6.32 vs 37.90±5.97 ng/ml, P〈0.01） and Ⅳ-C （79.39±10.52 vs 21.40±4.17 ng/ml, P〈0.01） were significantly increased in the model group as well. Changes of the indexes were similar to the pathological damage of the liver. Conclusion： The results suggested that activation of TNF-α in liver tissues may be the common pathogenic mechanism of liver fibrosis. TNF-α may be a useful index for the diagnosis of hepatic fibrosis which worthies further investigation.     

Experimental Study on Inhibitory Effect of Niacinamide on Tumor Necrosis Factor-alpha-induced Matrix Degradation of Annulus Fibrous Tissue in vitro

The inhibitory effect of niacinamide on tumor necrosis factor-α （TNF-α） induced annulus fibrous （AF） degradation was assessed, and the mechanism of the inhibition was investigated. Chiba＇s intervertebral disc （IVD） culture model was established. Forty-eight IVDs from 12 adult Japanese white rabbits were randomly divided into 4 groups （12 IVDs in each group）, and various concentrations of niacinamide and TNF-α were added to the medium for intervention： negative control group, niacinamide control group （0.5 mg/mL niacinamide）, degeneration group （10 ng/mL TNF-α）, and treatment group （0.5 mg/mL niacinamide and 10 ng/mL TNF-α）. After one week＇s culture, AFs were collected for glycosaminoglycan （GS） content measurement, safranin O-fast green staining, and immunohistochemical staining for type Ⅰ , Ⅱ collagen and cysteine containing aspartate specific prote- ase-3 （Caspase-3）. It was found that the GS content in treatment group was increased by about 48% as compared with degeneration group （t=16.93, P〈0.001）, and close to that in niacinamide control group （t=0.71, P=0.667）. Safranine O-fast green staining exhibited higher staining density and better histological structure of AF in the treatment group as compared with the degeneration group. Immunohistochemical staining for both TypeⅠ and Ⅱ collagen demonstrated that lamellar structure and continuity of collagen in treatment group were better reserved than in degeneration group. Positive staining rate of Caspase-3 in AFs of negative control group, niacinamide control group, degeneration group and treatment group was 3.4%, 4.3%, 17.9% and 10.3% respectively. The positive rate in treatment group was significantly lower than in degeneration group （P〈0.01）. It was concluded that niacinamide could effectively alleviate TNF-α induced destruction and synthesis inhibition of matrix ingredients in AFs. The inhibition may be related with reduction of expression of Caspase-3. Thus, niacinamide is of potential f     

Electroacupuncture Delays Cartilage Degeneration by Modulating Nuclear Factor-κB Signaling Pathway

Objective: To illustrate the molecular mechanisms underlying the therapeutic effects of electroacupuncture(EA) on knee osteoarthritis(OA). Methods: Twenty-seven six-month-old New Zealand white rabbits were allocated into three groups in accordance with a random number table: normal group(no surgery-induced OA; without treatment), model group(surgery-induced OA; without treatment) and EA group [surgery-induced OA; received treatment with EA at acupoints Dubi(ST 35) and Neixiyan(EX-LE 5), 30 min twice a day]. After eight consecutive weeks of treatment, the histopathological alterations in cartilage were observed using optical microscopy and transmission electron microscopy, cartilage degeneration was evaluated by modified Mankin's score principles, the synovial fluid concentration of interleukin-1β(IL-1β), interleukin-6(IL-6), tumor necrosis factor-α(TNF-α) and matrix metalloproteinase-3(MMP-3) were evaluated by enzyme-linked immunosorbent assay, and the protein expression levels of IL-1β, IL-6, TNF-α, MMP-3, IκB kinase-β(IKK-β), nuclear factor of α light polypeptide gene enhancer in B-cells inhibitor α(IκB-α) and nuclear factor-κB(NF-κB) p65 were quantified by Western blot analysis. Results: EA treatment significantly improved cartilage structure arrangement and reduced cellular degeneration. The IL-1β, IL-6, TNF-α and MMP-3 of synovial fluid in the EA-treated group were significantly decreased compared with the model group(all P0.01). Compared with the model group, the IL-1β, IL-6, TNF-α, MMP-3, IKK-β and NF-κB p65 protein expressions in cartilage of EA-treated group were significantly decreased(all P0.01), whereas IκB-α expression was significantly up-regulated(P0.01). Conclusion: EA treatment may delay cartilage degeneration by down-regulating inflammatory factors through NF-κB signaling pathway, which may, in part, explain its clinical efficacy in the treatment of knee OA.     

Effect of Combination Regimen of Low-dose Gossypol Acetic Acid with Steroid Hormones on Expression of Protein Kinase C alpha （PKC-tx） and Cyclin D1 in Rat Testes

Objective To investigate the contraceptive mechanism of combination regimen of low-dose gossypol acetic acid (GA) with steroid hormones [desogestre/ethinylestradiol/testosterone undecanote(DSG/EE/TU)]. Methods Adult male rats were randomly divided into four groups. Group GH: rats were fed orally with gossypol acetic acid (GA, 12.5mg/kg) and desogestrel (DSG, 0.125mg/kg)/ ethinylestradiol (EE, 0.025mg/kg)/testosterone undecanoate (TU, 100mg/kg per day, qd×4 weeks or 10 weeks); group G: a single dose of GA (12.5mg/kg per day, qd×4 weeks or 10 weeks); group H: the same dosage of DSG/EE/TU as in group GH; group C: rats were treated with vehicle (1% methyl cellulose) as the control. Expression of protein kinase C alpha (PKC-α) and cyclin D1 in rat testes were tested mainly by immunohistochemistry (IHC) and Western blotting. Results IHC results showed that protein PKC-α was expressed mainly in interstitial tissue of testis among seminiferous tubule. The expression of PKC-α in groups H and GH at week 10 was decreased greatly compared with that in group C. The protein cyclin D1 was expressed mainly in residual body of seminiferous tubule cavosurface and interstitial tissue among seminiferous tubule of testis. Western blotting results showed that the expression of PKC-α in groups H and GH at week 10 was decreased significantly compared with that in group C (P<0.05). The expression of cyclin D1 in groups G, H or GH at week 10 rose significantly compared with that in group C (P<0.05).Conclusion The administration of low-dose gossypol acetic acid with steroid hormones for 10 weeks can decrease the expression of PKC-α greatly.     

Age-related decrease in expression of peroxisome proliferator-activated receptor α and its effects on development of dyslipidemia

Background Ageing is associated with increased incidence of dyslipidemia. To investigate potential molecular mechanisms, the effects of age and fibrate administration on peroxisome proliferator-activated receptor α(PPARα) expression in livers of young and old rats were studied.Methods A total of 16 young (2-month-old) and 16 old rats (24-month-old) were randomly assigned to a control group and fenofibrate group (fenofibrate in a total therapeutic dosage of 0.5% in ratio to each treated rat weight in 14 days). RT-PCR was applied to evaluate hepatic mRNA expression of PPARα and its target genes. Western blotting was used to determine PPARα protein level in liver tissue. Results When compared with 2-month-old rats, the liver tissue from 24-month-old rats showed reduced expression of PPARα mRNA (52%, P&lt;0.05) and protein (109%, P&lt;0.01). Consequently, the mRNA levels of PPAR target genes, LPL, ACO, ACS and CPT-1 were markedly lowered by 19%, 8%, 13% and 9% respectively, and apoCIII increased by 24% in livers from 24-month-old rats, compared with values obtained from 2-month-old rats (P&lt;0.05). Fenofibrate therapy significantly lowered plasma triglyceride and total cholesterol levels in old rats, accompanied with improvement in hepatic expression of genes, including LPL, ACO, ACS, CPT-1 and apoCIII, but no change was found in PPARα expression in livers from either 24-month or 2-month-old rats. Conclusions The decrease in the hepatic PPARα expression is probably directly related to the lipid metabolic disturbances observed in old animals. The beneficial effects of fenofibrate administration in old rats suggests that fibrates may be useful for treating lipid disturbances in old people.