Effects of cyclooxygenase-2 inhibitors on gastric epithelial cell proliferating and gastric healing following hydrochloric acid-induced injury in rats

AIM: To clarify the effects of specific and non-specific cyclooxygenase-2 (COX-2) inhibitors on gastric epithelial cell proliferating and gastric healing following acid-induced damage. METHODS: Male Sprague-Dawley rats were given 1 mL of 0.6 mol/L hydrochloric acid (HCl) into the stomach. Ten minutes after the administration of the acid, the animals were given NS-398 (COX-2 inhibitor) or indomethacin. Levels of COX-1 and COX-2 in the gastric mucosa before and after HCl-administration were analyzed using western blotting and immunohistochemical staining. Proliferating cell nuclear antigen (PCNA) was detected using immunohistochemistry for epithelial cell proliferation. Gastric lesion index (LI) was assessed using planimetry. RESULTS: Expression of COX-2 was enhanced mainly in surface epithelial cells and neck cells following HCl-administration. At 24 h following acid administration, PCNA labeling index (PCNA-LI) was (22.72±4.33) % and (21.98±5.18) % in the groups treated with 40 mg/kg of NS-398 and indomethacin respectively, which was significantly lower than that in the control group [ (34.46±3.61) %, P< 0.05 ]; LI was (1.28±0.58) % and (1.16±0.56) % in the groups treated with 4 mg/kg and 40 mg/kg of NS-398, respectively, which was significantly higher than that in the control group [ (0.58±0.24) %, P< 0.05 ]. CONCLUSIONS: The present study demonstrated that cyclooxygenase-2 inhibitors delayed gastric mucosal healing by suppressing expansion of the mucosal proliferative zone. These results provide evidence that cyclooxygenase-2 plays an important role in gastric mucosal regeneration.     

Depressant effect and mechanism of atorvastatin on the chronic rejection of aortic allograft in rats

AIM: To investigate the depressant effect and mechanism of atorvastatin on the chronic rejection of aortic allograft in rats.METHODS: The models of abdominal aorta transplantation were made with micro-surgery in rats.The recipients were divided into three groups: allograft control group,atorvastatin-treated group and isograft control group.Vascular intimal thickness in all of the groups was observed by histological examination.The expression of proliferation cell nuclear antigenl(PCNA) and α-smooth muscle actin(α-SMA) were determined by immunohistochemistry.The content of nitric oxide was measured by nitrate reductase chromatometry.RESULTS: The vascular intimal thickness in atorvastatin-treated group (11.60%±2.40%) was lower than that in allograft control group (34.60%±6.40%,P<0.05) and higher than that in isograft control group (1.15%±0.65%,P<0.05).The expression level of PCNA was decreased in atorvastatin-treated group (4.80%±0.80%) than that in allograft control group (18.40%±1.80%,P<0.05) and higher than that in isograft group (1.20%±0.40%,P<0.05).CONCLUSION: The expression of PCNA in the transplanted aorta is suppressed by atorvastatin,which results in relief of chronic rejection of aortic allograft.     

Role of ERK on proliferation of airway smooth muscle cells in chronic asthmatic rats

AIM: To investigate the roles of extracellular signal-regulated kinase(ERK) signaling pathway on regulating proliferation of airway smooth muscle by observing the expression of ERK in airway smooth muscle(ASM) in chronic asthmatic rats.METHODS: Airway remodeling was detected in chronic asthmatic rats by using image analysis system. The expressions of ERK and proliferating cell nuclear antigen(PCNA) in lung tissue from chronic asthmatic rats were observed by immuocytochemistry staining. The expressions of ERK1/2, p ERK1/2 and PCNA were detected in airway smooth muscle (ASM) by immunofluorescence double staining with confocal microscopy, and the expressions of protein or mRNA of ERK and PCNA in ASM were also detected by immunoblotting and hybridization in situ,respectively.RESULTS: The thickening of smooth muscle and structural remodeling in airway were observed in chronic asthmatic rats by image analysis. The enhanced expressions of ERK and PCNA appeared obviously increased in same lung tissue and the expressions of protein or mRNA of ERK and PCNA were significantly increased in ASM.CONCLUSION: ERK signal pathway might be an important pathway on regulating cell proliferation of ASM resulting in asthmatic airway remodeling.     

Prevention of isinglass on the chronic atrophic gastritis in rats and its mechanism

AIM: To evaluate the effect of isinglass on chronic atrophic gastritis(CAG) in rats and its mechanism. METHODS: An animal model of CAG in accordance with the previous experience of combined administration of 60% ethanol, 20 mmol/L sodium deoxycholate and 0.1% ammonia water was established in SD rats. Isinglass was used as preventive therapy while we were establishing CAG rat model. Finally all the rats were executed and pathologic changes of the gastric mucosa were studied by gross appearance and microscopy and serum epidermal growth factor (EFG) and growth hormone(GH) contents were tested. RESULTS: In each isinglass prevention group, inflammation grade of gastric antrum was less than that in model group (P<0.01) while the mean ratio of the thickness of gastric mucosal gland and muscularis mucosa (L1/L2), the number of gastric glands in 1 mm lengths of mucosal layer in longitudinal sections were much better than those in model group (P<0.01).They were very close to normal control group (P>0.05). The expression of proliferating cell nuclear antigen (PCNA) in gastric mucosa and serum EFG level were higher than those in model group (P<0.01, P<0.05), but serum GH content showed no different between isinglass prevention group and model group. CONCLUSION: Isinglass preventes the gastric mucosal atrophy in the CAG model. Its mechanism may be related to the effects of decreasing the gastric mucosal damage， promoting the cell proliferation and increasing of internal EFG secretion.     

Effects of Yangxue decoction and Yangxue-Jiedu decoction on imiquimod-induced psoriasis-like mouse model

AIM: To investigate and compare the effects of Yangxue (YX) decoction and Yangxue-Jiedu (YXJD) decoction on psoriasis-like mouse skin lesions. METHODS: BALB/c mice (n=50) were randomly divided into control group, model group, methotrexate (MTX) group, YX group and YXJD group (10 mice in each group). The psoriasis-like mouse model was induced by topical application of imiquimod cream on the back. The skin water/oil test pen was used to detect the water/oil content of the skin in the back of the mice. The pathological changes of the lesions were observed by HE staining and the thickness of the epidermis was measured. The immunohistochemical staining was used to observe the skin lesions, and the mRNA expression levels of interleukin (IL)-17, IL-23 and IL-1β in skin lesions were detected by real-time PCR. RESULTS: The skin lesions in YX, YXJD and MTX group were better than those in model group, with lower psoriasis area and severity index (PASI) score and skin thickness. The skin water/oil content in YXJD group was higher than that in model group (P<0.05). The expression of proliferating cell nuclear antigen (PCNA) and the positive expression of CD3⁺ T cells in the skin of YXJD group were lower than those in YX group, and the skin thickness was lower than that in YX group (P<0.05). The results of real-time PCR showed that relative mRNA expression of IL-17, IL-23 and IL-1β in YX group and YXJD group was lower than that in model group (P<0.05), and the relative mRNA expression of IL-1β in YXJD group was lower than that in YX group. Administration of YXJD decoction showed better therapeutic effect than MTX. CONCLUSION: YX decoction and YXJD decoction relieve imiquimod-induced skin lesions by reducing immune response. Meanwhile, the effect of YXJD decoction is better than that of YX decoction.     

Influence of ginsenoside Re on vascular intima hyperplasia and NF-κB p65 signaling pathway in balloon-injured rats

AIM: To investigate the inhibitory effect of ginsenoside Re on intimal hyperplasia induced by balloon-injury and to explore the role of NF-κB p65 signaling pathway in the process. METHODS: SD rats(n=40) were divided into 5 groups randomly: sham operation group, model group, low-dose ginsenoside Re group, middle-dose ginsenoside Re group and high-dose ginsenoside Re group. The carotid artery intima injury model was established by 2F balloon catheters in all groups except the sham operation group. The day after modeling, the animals in model group and sham operation group were administered intragastrically with distilled water, and the rats in low-dose, middle-dose and high-dose ginsenoside Re groups were given ginsenoside Re at doses of 12.5 mg/kg, 25mg/kg and 50 mg/kg, respectively. After 14 continuous days, the morphological changes of the injured arteries were observed by HE staining and the lumen area, intima area and media area as well as the ratio of intimal area/media area were determined. The expression of tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β) were detected by real-time PCR. The proliferating cell nuclear antigen(PCNA) and nuclear factor-kappa B(NF-κB) p65 were examined by immunohistochemistry.RESULTS: Compared with sham operation group, the vessel cavity was narrowed(P<0.01), the mRNA levels of TNF-α and IL-1β, and the protein expression of PCNA and NF-κB p65 were increased in model group(P<0.05). Compared with model group, the vascular intimal hyperplasia was alleviated obviously(P<0.05), and the mRNA levels of TNF-α and IL-1β, and protein expression of PCNA and NF-κB p65 were decreased in medium and high-dose ginsenoside Re groups(P<0.05). CONCLUSION: Ginsenoside Re inhibits the vascular neointimal hyperplasia induced by balloon-injury in rats, and the molecular mechanism may be related to the inhibition of NF-κB p65 signaling pathway.     

Effects of different antioxidants on MMP-9 protein expression in fetal membrane tissue

AIM： To find out the influences of different antioxidants on the protein expression of matrix metalloproteinase 9 (MMP-9) in the membrane tissue of premature rupture cultured in vitro. METHODS：Eight pregnant women of premature rupture of membranes (PROM) who had delivered by cesarean section before labor were enrolled in the study and divided into 2 groups: term premature rupture of membranes (TPROM) and preterm premature rupture of membranes (PPROM). The fetal membrane tissues from each case was collected and divided into 3 sub-groups, which were cultured for 24 h with phosphate buffered saline (PBS, control group), 0.5 mmol/L alpha-lipoic acid (α-LA), or 28.8 g/L vitamin C+1.8 g/L vitamin E in vitro. The protein expression of MMP-9 was determined by immunohistochemistry and Western blotting. RESULTS：MMP-9 was located in the chorionic cells and neutrophils in TPROM tissues and there was no significant difference among samples of different treatments. In PPROM tissues, MMP-9 was found not only in the chorionic cells and neutrophils, but also in the amniotic epithelial cells. The integral absorbance values in antioxidant-treated samples were lower than that in PBS-treated samples, and the significant difference between α-LA-treated samples and vitamin C+vitamin E-treated samples was observed. The expression of pro-MMP-9 in TPROM tissues showed no significant difference after treated with different antioxidants, but the active MMP-9 expression was decreased after treated with antioxidants, and the influence of vitamin C+vitamin E was stronger than α-LA. The expression of pro-MMP-9/active MMP-9 in PPROM tissues was decreased after treated with antioxidants, and the influence of vitamin C+vitamin E was stronger than α-LA. CONCLUSION：Antioxidants result in the down-regulation of MMP-9 protein expression, and the influence of vitamin C+vitamin E is stronger than α-LA, indicating that these antioxidants can be used clinically to prevent premature rupture of membranes.     

Expression and significance of TLR4/NF-κB in pulmonary vascular remodeling in smoking rats

ATM: To observe the expression of Toll-like receptor 4 (TLR4), nuclear factor-κB subunit P65 protein (NF-κB P65) and proliferating cell nuclear antigen (PCNA) in the pulmonary vascular tissues of the rats exposed to smoke, and to explore the possible mechanism of TLR4/NF-κB signaling pathway in pulmonary vascular remodeling. METHODS: SPF male healthy rats (n=48) were randomly divided into control group, smoke exposure for 4 weeks group (S4 group), smoke exposure for 8 weeks group (S8 group) and smoke exposure for 12 weeks group (S12 group), with 12 rats in each group. HE staining was used to observe the morphological changes of pulmonary vessels, and then the pulmonary vascular wall area/total vascular area (WA%) and vascular wall thickness/vascular external diameter (WT%) were measured by the medical image analysis system. The expression of TLR4, NF-κB P65 and PCNA in the pulmonary vascular tissues was detected by immunohistochemical staining. The protein content was expressed by the average integral absorbance. The mRNA expression of TLR4 in the pulmonary vessels was detected by RT-qPCR. The relationships between WA%, WT%,TLR4 protein, TLR4 mRNA, P65 protein, PCNA protein and pulmonary vascular remodeling, and another relationships between WA%, WT%, P65 protein, PCNA protein and TLR4 protein were analyzed.RESULTS: The WA% and WT% in smoke exposure groups significantly increased compared with control group, and the ratio was proportional to the time of smoke exposure. The protein expression of TLR4, p65 and PCNA, and the mRNA expression of TLR4 in smoke exposure groups also increased significantly compared with control group. CONCLUSION: The extent of pulmonary vascular remodeling in the rats increases when the protein expression of TLR4 is up-regulated. There is a positive correlation between pulmonary vascular remodeling and the protein expression of TLR4 and NF-κB P65. Pulmonary vascular remodeling may be related to the activation of TLR4/NF-κB signaling pathway.     

Selenium-enriched Spirulina platensis promotes proliferation of hepatocytes in rat partial hepatectomy

AIM: To explore the effects of selenium-enriched Spirulina platensis (Se-SP) on proliferation of hepatocytes in rat hepatectomy. METHODS: Rat hepaectomy model was conducted using male Wistar rats. The rats were randomized into five groups: operation groups with 150 (H), 50 (M) and 15 (L) mg·kg^-1·d^-1 of Se-SP, placebo-control (P) and sham operation group (F). Activities of glutathione peroxidase (GPx) and thioredoxin reductases (TR) in hepatocytes were determined by chemical colorimetry. The expression index of proliferating cell nuclear antigen (PCNA) in hepatocytes was detected by immunohistochemistry, and the level of ［³H］-TDR incorporation in regenerative hepatocytes was analyzed by radio-immunity. RESULTS: Activity of GPx and TR, PCNA expression index as well as ［3H］-TDR insertion in hepatocytes (in vitro) were obviously higher (P<0.05) in L groups than those in P and F groups. All parameters were significant changed (P<0.05) after operation in H, M, L and P groups whereas some slightly change in F group. Furthermore, correlation analysis showed that the levels of GPx and TR in hepatocytes all showed positive correlation with PCNA expression (r²=0.77 and 0.87, respectively) and with ［³H］-TDR incorporation level (r² = 0.73 and 0.84, respectively) in hepatocytes. CONCLUSION: Se-SP enhances hepatocyte proliferation in rat hepatectomy, up-regulation of selenoenzymes might be responsible for this effect.     

Effect of hypoxia on the expression of proliferating cell nuclear antigen and phenotype of cardiac fibroblasts

AIM:To investigate effect of hypoxia on the expression of proliferating cell nuclear antigen(PCNA) and phenotype of cardiac fibroblasts(CFs). METHODS:The purified cardiac fibroblasts were cultured and divided randomly into there groups :control group, moderate hypoxia(MH) group and severe hypoxia(SH) group. After 72 h, MTT method was used to investigate the proliferation of CFs, and the ultrastructure of fibroblasts were observed with transmission electron microscopy. The expression of PCNA and α-actin in cardiac fibroblasts were measured by the means of immunohistochemistry and laser scanning confocal microscopy, respectively. RESULTS: MTT A_{490 nm}value of MH group was significantly higher than that of control group by (18.4±25.0)% (P＜0.05), whereas MTT A_{490 nm} value of MH group was significantly lower than that of control group by (15.8±25.0)% (P＜0.05).The immunohistochemistry experiment showed that there was basal PCNA expression in control CFs, and it was increased in MH CFs(P＜0.05 vs control group), but there was no significant difference between SH and control CFs. Observed with transmission electron microscopy, the control CFs had typical phenotype of fibroblasts: shuttle-shaped, abundant rough endoplasmic reticulums (RER) and golgi complexes, but few mitochondria or micromyofilaments in cytoplasm. After MH for 72 h, there appeared lots of micromyofilaments in cytoplasm, but there were little micromyofilaments in SH CFs. Observed with laser confocal scanning microscopy, there was lower expression of α-actin in CFs of control group, while many regular bundles of micromyofilaments and the expression of α-actin were signifiantly increased (P＜0.05 vs control group) in CFs treated with MH. The α-actin expression in severe hypoxia CFs was not significantly different from control group. CONCLUSION:MH made CFs have the characteristics of myofibroblasts phenotype and enhanced PCNA expression.     

Influence of hypoxia-inducible factor-1 alpha on lung cancer cell A549 growth in vitro and in vivo

AIM: To study the role of hypoxia-inducible factor-1alpha(HIF-1α) on lung cancer cells A549 growth in vitro and in vivo. METHODS: To observe the growth rate of A549 cells after HIF-1α transfected, A549 cells (1×10⁶/mouse) were inoculated subcutaneously into 20 nude mice, which were randomly divided into two groups: the control group (group A, n=10), the HIF-1α transfected group(group B, n=10). The weights of subcutaneous tumor were detected. The resected specimens were made into paraffin-embedded sections. The proliferating cell nuclear antigen (PCNA) was identified by immunohistochemistry(ISH). The expressions of HIF-1α、 apoptosis-related protein survivin and bcl-2 were analyzed by Western blot. RESULTS: The growth rates of the HIF-1α transfected lung cancer cells A549 were significantly increased, and more importantly, the HIF-1α transfected lung cancer cells A549 was able to enhance lung cancer growth in nude mice(P＜0.05). The PCNA were increased significantly in group B, compared with group A. The expressions of HIF-1α, survivin and bcl-2 in group B were increased significantly than that of group A. CONCLUSIONS: HIF-1α increases lung cancer cells A549 growth in vitro and in vivo and its mechanism may be due to promotion of proliferation and inhibition of apoptosis.     

Expression and histogenesis of matrix metalloproteinase-9 and transforming growth factor-beta 1 in acute cerebral ischemia model of rats

AIM:To observe the expression and tissue localization of matrix metalloproteinase 9 (MMP-9) and transforming growth factor beta 1 (TGF-β1) in the rat acute cerebral ischemia model. METHODS:Male Wistar rats were used to establish acute cerebral ischemia model by a suturing method. The rats were divided into normal control group, sham group and ischemia 6 h, 12 h, 1 d, 2 d, 6 d and 14 d groups. The rat cerebral cortex and hippocampus of the brain were collected at different time points.The mRNA and protein levels of MMP-9 and TGF-β1 in the brain tissues were detected by real-time PCR and in situhistochemistry staining, respectively. The levels of MMP-9 and TGF-β1 in the plasma were also measured by ELISA. RESULTS:The results of real-time PCR showed that the mRNA levels of MMP-9 began to increase 6 h after acute ischemia and reached to a peak 2 d after acute ischemia. Similarly, the mRNA level of TGF-β1began to rise 12 h after acute ischemia and reached to the highest level 6 d after acute ischemia. Compared with the sham rats, the mRNA levels of MMP-9 and TGF-β1 in the rat brains that collected at ischemic time of 12 h, 1 d, 2 d, 6 d and 14 d were significantly increased. Moreover, results of in situhistochemical staining showed that the expression of MMP-9 was detected at cerebral cortex and hippocampus 1 d after acute cerebral ischemia.Further studies showed that MMP-9 dyeing of the rat cerebral cortex was most obvious 2 d after the acute cerebral ischemia. Similarly, the rat cortex and hippocampus began to express TGF-β1 2 d after acute ischemia and TGF-β1 staining at rat cerebral cortex was most obvious 6 d after the acute cerebral ischemia. In addition, ELISA showed that the increase in MMP-9 and TGF-β1 was detected in the plasma 12 h after ischemia. Compared with the sham rats, the level of these 2 factors significantly upregulated since 1 d after ischemia. CONCLUSION: The brain tissue itself contributes to the upregulation of MMP-9 and TGF-β1 post acute cerebral ischemia, which shed light on the related research in the field.     

Effect of CHOP expression knock-down on apoptosis of renal tubular epithelial cells

AIM:To study the effect of C/EBP homologous protein (CHOP) on the apoptosis of renal tubular epithelial HK2 cells. METHODS:The serum mRNA levels of CHOP in the patients with acute kidney injury and healthy controls were detected by qPCR. In vitro, renal tubular epithelial HK2 cells were divided into control group, negative group (transfected with negative control siRNA), si-CHOP group (transfected with CHOP siRNA), and induced by transforming growth factor-β1 (TGF-β1). The viability of the cells was measured by MTT assay, and the apoptotic rate was analyzed by flow cytometry. The protein levels of nuclear antigen Ki-67, proliferating cell nuclear antigen (PCNA), caspase-3 and cleaved caspase-3 were determined by Western blot. RESULTS:Compared with the healthy controls, the serum mRNA levels of CHOP in the patients with acute kidney injury were increased significantly (P<0.05). Transfection with CHOP siRNA significantly decreased the expression of CHOP in the renal tubular epithelial HK2 cells (P<0.05). Knock-down of CHOP expression by siRNA significantly increased the viability of renal tubular epithelial HK2 cells (P<0.05), decreased the apoptotic rate (P<0.05), increased the expression of Ki-67 and PCNA (P<0.05), and down-regulated the protein level of cleaved caspase-3 (P<0.05). CONCLUSION:The serum mRNA levels of CHOP were increased in the patients with acute kidney injury. Knock-down of CHOP expression inhibits the apoptosis of renal tubular epithelial cells by regulating the expression of proliferation-and apoptosis-related proteins.     

Effect of idazoxan on permeability of blood-brain barrier and expression of MMP-9/TIMP-1 in mouse experimental autoimmune encephalomyelitis

AIM：To study the effect of idazoxan (IDA) on the permeability of blood-brain barrier (BBB) and the expression of matrix metalloproteinase 9 (MMP-9) and tissue inhibitor of metalloproteinase 1 (TIMP-1) in mouse experimental autoimmune encephalomyelitis (EAE).METHODS：Female C57BL/6 mice (n=36) were randomly divided into control group, EAE group and IDA group, with 12 mice in each group. EAE was induced by myelin oligodendrocyte glycoprotein 35-55 (MOG35-55). IDA (2 mg/kg, ip, bid) was administered for 15 d after immunization. The neurological defects of the mice were observed daily and scored. The pathological changes were observed under microscope with HE staining and LFB myelin staining. The BBB permeability was detected by Evans blue extravasation. The expression of MMP-9 and TIMP-1 in the brain of EAE mice was determined by Western blotting.RESULTS：Compared with EAE group, the score of neurological defects in IDA group was decreased, the inflammation was relieved, the BBB permeability was reduced, and the expression MMP-9 and the ratio of MMP-9/TIMP-1 were decreased (P<0.05).CONCLUSION：The neuroprotective effect of IDA on mouse EAE might be related to the down-regulation of MMP-9 and the ratio of MMP-9/TIMP-1, thus reducing the degradation of BBB and the permeability of BBB, and ameliorating the pathologic process of EAE.     

Effect of Shaofu-Zhuyu decoction on MAPK/ERK signaling pathway in rats with endometriosis

AIM: To observe the effects of Shaofu-Zhuyu decoction (SFZY) on mitogen-activated protein kinase (MAPK)/extracellular signal-regulated kinase (ERK) signaling pathway in the rats with endometriosis (EM), and to explore the mechanism of SFZY for treatment of EM.METHODS: Healthy female SD rats were used to establish the EM model. The rats were randomly divided into blank control group, model group, positive control group, and low dose, middle dose and high dose of SFZY groups. The pathological changes of the endometriotic tissue were observed by HE staining. The levels of tumor necrosis factor-α (TNF-α), interleukin-6(IL-6) and IL-8 in the uterine tissue were detected by ELISA. The mRNA expression of ERK, vascular endothelial growh factor (VEGF) and matrix metalloprotein-9 (MMP-9) was detected by RT-qPCR. The protein expression of nuclear factor-κB (NF-κB), MAPK and MAPK-ERK kinase (MEK) was determined by Western blot.RESULTS: Compared with model group, the levels of TNF-α, IL-6 and IL-8 in the uterine tissue of the rats in middle dose and high dose of SFZY groups were significantly decreased (P<0.05), the mRNA expression of ERK, VEGF and MMP-9 was significantly reduced, and the protein expression of NF-κB, MEK and MAPK was decreased significantly in the rat endometriotic tissues (P<0.05).CONCLUSION: SFZY may play a key role in the treatment of EM by regulating MAPK/ERK signaling pathway.     

Astrocyte proliferation in the rat hippocampus after middle cerebral artery occlusion

AIM: To study rat astrocyte proliferation in ipsilateral hippocampus following focal cerebral ischemia. METHODS: Ischemia was induced by temporary middle cerebral artery occlusion (MCAO). In hippocampus of rats at 3, 7 and 30 days after MCAO, the numbers and anatomic distribution of glial fibrillary acidic protein (GFAP) were detected by immunohistochemistry. The protein expression of GFAP and proliferating cell nuclear antigen (PCNA) in the ipsilateral hippocampus were analyzed by Western blot analysis. RESULTS: Astrocytes appeared hypertrophic, with increased process thickness and numbers at 7 days after MCAO, and the highest density of astrocytes were seen at 30 days in the CA1, CA2 regions of the ipsilateral hippocampus. Western blot analysis revealed that GFAP levels were normal at 3 days, but increased by 7 days and remained elevation at 30 days. Western blot analysis of PCNA protein also revealed identified upregulation PCNA at 3 days after MCAO and the expression peaked at 7 days. CONCLUSION: This study demonstrates that focal cerebral ischemia in the rat results in a rapid response, a process often referred to as reactive astrogliosis or glial scarring, from resident astrocytes of the ipsilateral hippocampus to the side of ischemia.     

Expression of MMP3 in subchondral bones in early experimental osteoarthritis

AIM: To demonstrate that matrix metalloproteinase 3(MMP3)plays MMP3 play an important role in the pathogenesis of osteoarthritis by studying the expression of MMP3 in subchondral bones in early experimental osteoarthritis at gene and protein levels. METHODS: The SD rats were randomly divided into 2 groups: experimental group and control group, each containing 30 rats with similar body weight. The right knee joints of the rats in experimental group underwent surgery, which involved in both medial collateral ligament (MCL) transection and medial meniscectomy, while the animals in control group were only carried out a sham operation. The rats were killed at the 1st, 2nd and 4th weeks post-surgery to obtain the right knee joints. Pathological analysis was performed to validate this early osteoarthritic rat model. The expression of MMP3 in subchondral bones at mRNA and protein levels was evaluated by real-time polymerase chain reaction and immunohistochemical staining, respectively. RESULTS: The expression of MMP3 in subchondral bones was significantly increased at both the 1st and 2nd weeks post-surgery in experimental group, with the fold changes of 8.34 (P<0.05) and 4.85 (P<0.05), respectively, as compared with control group. No differentially expression of MMP3 was observed at the 4th week post-surgery between these 2 groups. A lot of MMP3 positive cells, including small mononuclear cells and bigger polynuclear giant cells, were found in subchondral bones in experimental group at the 1st and 2nd weeks post-surgery,but not in control group. At the 4th week post-surgery, no MMP3 positive cells were found in subchondral bones of both groups. CONCLUSION: MMP3 plays an important role in the pathogenesis of early experimental osteoarthritis.     

Hypoxic tubulointerstitial fibrosis and swimming exercise change expression of urotensin II and its receptor GPR14 in rats

AIM: To observe the expression of urotensin II (UII) and its receptor GPR14 in rats with hypoxic tubulointerstitial fibrosis, and to explore the changes after swimming exercise. METHODS: The animal model of hypoxic renal interstitial fibrosis was established by exposing the rats to isobaric hypoxic chamber for 7 weeks (8 h/d, 7 d/week). Forty-five male SD rats were randomly divided into normal control group (control), hypoxic 7-week group (hypoxia) and hypoxic 3-week and swimming without loads 4-week group (swimming). Serum creatinine (Scr) and blood urea nitrogen (BUN) were measured by chemical colorimetry, and UII was detected by ELISA. The content of hydroxyproline (Hyp) in the renal homogenate was assayed. The mRNA expression of UII and GPR14 were detected by RT-PCR. The protein level of UII was determined by the method of immunohistochemistry. Meanwhile, the renal specimens were prepared to observe renal interstitial fibrosis by van Gieson(VG) staining. RESULTS: The content of Scr and BUN in hypoxia group was lower than that in control group by 18.5% and 14.1%,respectively, while there was no significant difference between swimming group and hypoxia group. The content of Hyp in hypoxia group was 42.9% higher than that in control group, while swimming group was 26.1% lower than that in hypoxia group. The plasma content of UII in hypoxia group was 380.8% higher than that in control group, while swimming group was 42.6% lower than that in hypoxia group. The mRNA expression of UII in the kidneys was obviously up-regulated by 104.5% in hypoxia group compared with control group, while it was markedly down-regulated by 33.2% in swimming group compared with hypoxia group. The mRNA expression of GPR14 in the kidneys was significantly up-regulated by 35.4% in hypoxia group compared with control group. However, no significant difference between hypoxia group and swimming group was observed. The UII protein level in the kidneys of hypoxia rats was distinctly higher than that in control group and lower in swimming group than that in hypoxia group. VG staining revealed that the renal interstitial fibrosis was found in hypoxia group, which was significantly alleviated by swimming exercise. CONCLUSION: The levels of UII and GPR14 increase in the kidneys of the rats with hypoxic tubulointerstitial fibrosis. Moderate swimming exercise alleviates the tubulointerstitial fibrosis induced by hypoxia and decreases the expression of UII.