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1.
INTRODUCTION: The aim of this study was to estimate the influence of corticosteroids on soluble MMP-2, MMP-9 and VCAM-1 in patients with Graves ophthalmopathy (GO) in order to assess their usefulness as a guideline in a therapeutic approach. MATERIAL AND METHODS: Serum gelatinases and VCAM-1 were detected in three groups of subjects: 20 patients with GO (CAS > or = 3, anamnesis of GO > or = 1 yr), 12 patients with no clinical symptoms of ophthalmopathy (Gd) and 10 healthy volunteers. Corticosteroid therapy consisted of intravenous infusions (2 series, 3 grams each time) of methylprednisolone (MP) and subsequent treatment with oral prednisone (60 mg per day) in a tapering schedule. The serum samples were collected 24 hours before MP, 24 hours after MP, after 14 days of treatment with prednisone and at the end of corticosteroid therapy. The levels of soluble MMP-2, MMP-9 and VCAM-1 were determined by the ELISA method. RESULTS: We have found no differences in serum MMP-2 between the groups studied and a significant reduction after MP only in corticosteroid-resistant GO patients. Soluble MMP-9 was highest in the GO group compared with both the Gd and control individuals. Moreover serum MMP-9 decreased in corticosteroid-responsive GO patients after MP and remained at the lower level at the end of the study. Positive correlations between MMP-2 and MMP-9 before and after MP administration were observed. Serum VCAM-1 was significantly elevated both in GO and Gd subjects and pre-treatment VCAM-1 levels were elevated in corticosteroid-responders compared with non-responders. CONCLUSIONS: Our results suggest that serum VCAM-1 may serve as a marker predicting the efficacy of corticosteroids and that soluble MMP-9 may be helpful in monitoring corticosteroid administration and in decision-making with regard to further GO treatment.  相似文献   

2.
Two hundred, one-day-old broiler chicks were divided into groups 1, 2 and 3 containing 60, 70 and 70 chicks, respectively. The groups were divided into subgroups of 10 chicks that were vaccinated according to the following scheme: group 1 unvaccinated control, group 2 vaccinated subcutaneously at 1 day old with inactivated oil adjuvant vaccine (IOAV) in combination with live B1 vaccine. Group 3 was vaccinated in the same mode as group 2 with IOAV and live Ulster 2C vaccine. All birds were challenged when they were 28 days old. Mortality rate, body weight gain and feed conversion ratio (FCR) were monitored before and after challenge. All the chickens in group 1 died, indicating that there was no disease resistance of this unvaccinated control group of chickens. Conversely, the monitored disease resistance of chickens in groups 2 and 3 was 68.57% ± 18.64 and 88.57% ± 9.00, respectively (P < 0.05). The morbidity of chickens in groups 2 and 3 was 37.89% ± 14.36 and 14.76% ± 12.40, respectively (P < 0.05). The body weight gain, feed intake and FCR of group 3 were significantly better than those of group 2 (P < 0.05) during 1–42 days old. The simultaneous vaccination with B1 or Ulster 2C and IOAV of 1-day-old chicks gave some protection of 28-day-old broilers without a booster vaccination.  相似文献   

3.
Vitamin E suppresses the hypercholesterolemia-induced cardiac oxidative stress. The objectives were to investigate: if vitamin E regresses the hypercholesterolemia-induced oxidative stress in hearts and if regression is associated with decreases in the antioxidant reserve. The rabbits were assigned to 4 groups: I, regular diet (2-months); II, 0.25 % cholesterol diet (2-months); III, 0.25 % cholesterol diet (2-months) followed by regular diet (2-months); and IV, 0.25 % cholesterol diet (2-months) followed by regular diet with vitamin E (2-months). Blood samples were collected before and at the end of protocol for the measurement of total cholesterol (TC). Hearts were removed at the end of the protocol under anesthesia for the assessment of oxidative stress parameters, malondialdehyde (MDA), and tissue chemiluminescent (CL) activity. High cholesterol diet increased the serum levels of TC, and regular diet with or without vitamin E reduced the TC levels to a similar extent. The MDA content of the heart in groups I, II, III, and IV were 0.074 ± 0.015, 0.234 ± 0.016, 0.183 ± 0.028 and 0.169 ± 0.016 nmol/mg protein, respectively. Regular diet following high cholesterol diet reduced the MDA levels (0.234 ± 0.016 vs. 0.183 ± 0.028 nmol/mg protein but vitamin E did not reduce the MDA levels. The cardiac-CL activities were similar in groups’ I, II, and III (30.11 ± 0.7 × 106, 32.9 ± 1.43, and 37.92 ± 8.35 × 106 RLU/mg protein). The activity decreased in group IV, suggesting that vitamin E increased the antioxidant reserve while lowering serum cholesterol did not increase antioxidant reserve. In conclusion, hypercholesterolemia increases cardiac oxidative stress and regular diet regresses hypercholesterolemia-induced oxidative stress but vitamin E does not further regress hypercholesterolemia-induced cardiac oxidative stress. Vitamin E reduces oxidative stress in the heart tissue in spite of a decrease in CL activity (increase in antioxidant reserve).  相似文献   

4.
Lysosomes in chick intestinal absorptive cells from rachitic (vitamin D-deficient) and vitamin D-replete animals were studied utilizing transmission electron microscopic histochemistry and ultrastructural morphometry. Absorptive cells from rachitic animals, serum calcium = 7.3±0.3 mg%, contained an average of 4.0±0.3 supranuclear lysosomes. In rachitic chicks sacrificed 9 hr post-injection of 1,25-dihydroxycholecalciferol, the active metabolite of vitamin D, the values for both serum calcium, 9.8 ± 0.2 mg%, and the number of apical absorptive cell lysosomes, 12.9±0.6, were increased over non-injected or vehicle-only injected animals. Lysosomes in vitamin D-replete absorptive cells were characterized by their intense staining with pyroantimonate, indicative of their high calcium content. The same organelles also produced a positive reaction for acid phosphatase. Rachitic lysosomes, also acid phosphatase positive, were only lightly stained with pyroantimonate. The lysosomal proliferation apparently induced by 1,25-dihydroxycholecalciferol may be a further indication that these organelles play a role in intestinal calcium transport and/or intracellular calcium homeostasis within the absorptive cell.  相似文献   

5.
目的:研究肺癌患者血清中血管内皮生长因子(VEGF)、组织金属蛋白酶抑制剂1(TIMP-1)、基质金属蛋白酶9(MMP-9)水平变化及临床意义。方法:选取2014年3月至2016年3月来我院治疗的91例肺癌患者为病例组,同期选取40例健康者为对照组,酶联免疫吸附测定法(ELISA)测定两组血清VEGF、TIMP-1、MMP-9水平,分析肺癌患者上述指标与病理特征的关系,并采用spearman检验分析相关性。结果:病例组血清VEGF、TIMP-1、MMP-9水平均高于对照组,差异均具有统计学意义(P0.05)。肺癌患者血清VEGF、TIMP-1、MMP-9水平均与肿瘤体积大小、TNM分期、淋巴结转移、远处转移有关(P0.05)。肺癌患者血清MMP-9与TIMP-1正相关(r=0.337,P0.05)、血清MMP-9与VEGF正相关(r=0.312,P0.05)、血清TIMP-1与VEGF正相关(r=0.316,P0.05)。结论:血清VEGF、TIMP-1、MMP-9相互作用、协同参与肺癌的发生及侵袭转移,可作为肺癌诊断及预后评估的生物学标志物。  相似文献   

6.
This study investigated effects of dietary supplementation with vitamin C, vitamin E on performance, biochemical parameters, and oxidative stress induced by copper toxicity in broilers. A total of 240, 1-day-old, broilers were assigned to eight groups with three replicates of 10 chicks each. The groups were fed on the following diets: control (basal diet), vitamin C (250 mg/kg diet), vitamin E (250 mg/kg diet), vitamin C + vitamin E (250 mg/kg?+?250 mg/kg diet), and copper (300 mg/kg diet) alone or in combination with the corresponding vitamins. At the 6th week, the body weights of broilers were decreased in copper, copper + vitamin E, and copper + vitamin C + vitamin E groups compared to control. The feed conversion ratio was poor in copper group. Plasma aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase activities, iron, copper concentrations, and erythrocyte malondialdehyde were increased; plasma vitamin A and C concentrations and erythrocyte superoxide dismutase were decreased in copper group compared to control. Glutathione peroxidase, vitamin C, and iron levels were increased; aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and copper levels were decreased in copper + vitamin C group, while superoxide dismutase, glutathione peroxidase, and vitamin E concentrations were increased; aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase were decreased in copper with vitamin E group compared to copper group. The vitamin C concentrations were increased; copper, uric acid, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and malondialdehyde were decreased in copper + vitamin C + vitamin E group compared to copper group. To conclude, copper caused oxidative stress in broilers. The combination of vitamin C and vitamin E addition might alleviate the harmful effects of copper as demonstrated by decreased lipid peroxidation and hepatic enzymes.  相似文献   

7.
目的:研究特布他林联合羧甲司坦片治疗慢性阻塞性肺疾病的疗效及对血清基质金属蛋白酶-9(MMP-9)、基质金属蛋白酶-12(MMP-12)、组织型金属蛋白酶抑制物(TIMP-1)水平的影响。方法:选取2015年3月至2018年2月我院收治的170例COPD患者,根据随机数字法分为观察组(87例)和对照组(83例)。对照组使用特布他林,观察组联合使用羧甲司坦。比较两组患者的临床疗效,治疗前后血清MMP-9、MMP-12、TIMP-1水平,肺功能指标,炎性因子水平的变化及不良反应的发生情况。结果:治疗后,观察组临床总有效率显著高于对照组(P<0.05),血清MMP-9、MMP-12、TIMP-1水平显著低于对照组(P<0.05),最大呼气流速(PEF)、1秒用力呼气容积(FEV1)、用力肺活量(FVC)及FEV1/FVC显著高于对照组(P<0.05),血清肿瘤坏死因子-α(TNF-α)、白细胞介素-8(IL-8)、中性粒细胞弹性蛋白酶(NE)水平均显著低于对照组(P<0.05)。观察组和对照组不良反应的发生率比较无显著差异(P>0.05)。结论:特布他林联合羧甲司坦片治疗COPD的临床疗效显著优于单用特布他林,且安全性更高,可能与其能有效降低血清MMP-9、MMP-12、TIMP-1水平有关。  相似文献   

8.
Biodegradable nanospheres or microspheres have been widely used as a sustained release system for the delivery of bioagents. In the present study, injectable sustained-release growth hormone-releasing factor (GRF) (1–32) microspheres were prepared by a double emulsion-in liquid evaporation process using biodegradable polylactic-co-glycolic acid (PLGA) as the carrier. The entrapment efficiency was 89.79% and the mean particle size was 4.41 μm. The microspheres were injected into mouse tibialis muscle. After 30 days, mice injected with GRF (1–32) microspheres (group I) gained significantly more weight than any other treatment group, including mice injected with the naked plasmid (group II) (10.26 ± 0.13 vs. 9.09 ± 0.56; P < 0.05), a mixture of microspheres and plasmid (group III) (10.26 ± 0.13 vs. 8.57 ± 0.02; P < 0.05), or saline (IV) (10.26 ± 0.13 vs. 6.47 ± 0.26; P < 0.05). In addition, mice treated with the GRF (1–32) microspheres exhibited the highest expression levels of GRF as detected by PCR, RT-PCR, and ELISA (mean 2.56 ± 0.40, P < 0.05, overall comparison of treatment with groups II, III, and IV). Additionally, rabbits were injected in the tibialis muscle with the same treatments described above. After 30 days, the group treated with GRF (1–32) microspheres gained the most weight. At day 30 postinjection, weight gain in group I was 63.93% higher than group II (plasmid) (877.10 ± 24.42 vs. 535.05 ± 26.38; P < 0.05), 108.59% higher than group III (blank MS) (877.10 ± 24.42 vs. 420.50 ± 19.39; P < 0.05), and 93.94% higher than group IV (saline) (877.10 ± 24.42 vs. 452.25 ± 27.38; P < 0.05). Furthermore, IGF-1 levels in the serum from GRF microsphere-treated group were elevated relative to all other groups. The present results suggest that encapsulation of GRF with PLGA increases GRF gene expression in muscle after local plasmid delivery, and stimulates significantly more weight gain than delivery of the naked plasmid alone.  相似文献   

9.
Receptors for luteinizing hormone/human chorionic gonadotropin (LH/hCG) have been identified in porcine, rabbit, rat, and human myometrium. To determine the estrous cycle and pregnancy related changes in the receptor capacity and affinity, radioreceptor assays were performed with membrane homogenates of porcine uterine tissues. Cycling gilts were divided into four experimental groups: I (n=6), day 1–2; II (n=5), day 6–7; III (n=5), day 11–12; and IV (n=6), day 18–20 of the estrous cycle. Pregnant pigs were divided into three experimental groups: I (n=5), day 35–40; II (n=5), day 65–70; and III (n=4), day 95–105 of pregnancy. The concentrations [femtomoles/mg protein (fmol/mg protein)] and affinities of unoccupied LH/hCG binding sites were characterized in all samples of myometrium. Receptor concentrations were highest (P<0.01) in groups II and III (19.3±2.5 and 35.8±2.1 fmol/mg protein, respectively), and was lowest in groups I and IV (5.3±1.4 and 7.5±0.7 fmol/mg protein, respectively). Receptor affinity constants (Ka) were consistent (P>0.05) throughout the estrous cycle [I, (5.1±1.5)×109; II, (3.0±0.8)×109; III, (3.2±0.9)×109; IV, 5.5±0.7×109 lm−1]. Plasma hormone concentrations of progesterone, estrogen and LH were typical of values noted at these times. During pregnancy, receptor concentrations were greatest (P<0.05) in group II (85.4±18.5 fmol/mg protein). In groups I and III receptor numbers were 10.8±2.3 and 26.7±6.6 fmol/mg protein, respectively. The Ka in group I was 10 times greater (P<0.05) than Ka in groups II and III, (I, 3.1±0.9×1010 lm−1; II, 3.4±0.3×109 lm−1; III, 3.3±1.1×109 lm−1). Plasma hormone concentrations typically found during pregnancy were noted. The function of these LH/hCG binding sites remains unknown; however, changes in receptor capacity during the estrous cycle and pregnancy support a role for modulation of the receptor by hormonal factors.  相似文献   

10.
目的:观察慢性肾小球肾炎血清基质金属蛋白酶9(matrix metalo protein-ase-9,MMP-9)、金属蛋白酶组织抑制剂1(tissue inhibitors of metalloproteinases,TIMP-1)的浓度与肾组织中MMP-9、TIMP-1表达的相关性,探讨慢性肾小球肾炎血清MMP-9、TIMP-1对肾脏纤维化的判断价值。方法:通过肾组织活检病理检查,将入选慢性肾炎的病例分增生组(A组)15例,纤维化组(B组)15例,另选10例志愿者作为健康对照组C组。应用免疫组化法观察A、B两组MMP-9、TIMP-1在肾组织中的表达情况,并且进行半定量分析,比较它们之间有无差别。应用ELISA双抗体夹心法检测A、B、C三组MMP-9、TIMP-1在血清中的浓度,比较它们之间有无差别。观察A、B两组MMP-9、TIMP-1在肾组织中的表达水平与在血清的浓度有无相关性。结果:A、B两组MMP-9在肾小球和肾间质少见表达,主要在肾小管上皮细胞浆中表达增高,两组之间表达的强度有显著差异性;A组TIMP-1在肾小球中少见表达,在肾小管上皮细胞增强。B组TIMP-1在肾小球中有少量表达,在肾小管上皮细胞较A组进一步增强,两组之间表达的强度有显著差异性(P0.05)。血清中MMP-9、TIMP-1浓度在A、B组显著高于C组,血清中MMP-9在A、B两组之间无显著差异性,血清中TIMP-1在A、B、C三组间两两比较有显著差别(P0.05)。结论:慢性肾炎患者血清中MMP-9、TIMP-1浓度与肾脏组织中MMP-9、TIMP-1的表达呈正相关。MMP-9、TIMP-1的相关性分析P值小于0.01。血清MMP-9、TIMP-1参与了肾脏纤维化的进展,慢性肾小球肾炎血清中MMP-9、TIMP-1的浓度可在一定程度上反映肾脏纤维化程度。  相似文献   

11.
This study investigated the effect of high‐dose vitamin C supplementation on growth, tissue ascorbic acid concentrations and physiological response to transportation stress in juvenile silver pomfret, Pampus argenteus (initial average weight 6.2 ± 0.2 g). Three practical diets were formulated to contain 100 (control), 450 and 800 mg ascorbic acid/kg diet, respectively, supplied as l‐ascorbyl‐2‐polyphosphate. Each diet was fed to triplicate groups of fish in circular tanks (3 m ø, 1.5 m depth) (60 fish/tank) for 9 weeks. Growth did not change significantly with dietary vitamin C levels, although an improvement tendency with an increase in vitamin C supplementation was observed. Ascorbic acid concentrations in the liver and muscle of fish fed diets containing graded levels of vitamin C were positively correlated with dietary levels of this vitamin. Tissue ascorbic acid concentrations significantly increased with increasing vitamin C supplementation. After 9 weeks, the fish were subjected to transportation stress for 4 h to determine the influence of high vitamin C supplementation on the physiological response to this stressor. Serum cortisol, glucose and lactate levels significantly increased in stressed fish. Serum cortisol and glucose concentrations after stress were significantly higher in fish fed the control diet (7.91 μg L?1 and 0.80 mm , respectively) than in the other groups. However, there were no significant differences in serum cortisol and glucose levels after stress between the 450 and 800 mg kg?1 diets. No significant change could be found in serum lactate levels after stress among the different treatments. In conclusion, the dietary administration of high doses of vitamin C could reduce stress in silver pomfret and increase the survival of fish under stress conditions.  相似文献   

12.
Deposition of islet amyloid polypeptide (IAPP) as amyloid is a pathological hallmark of the islet in type 2 diabetes, which is toxic to β-cells. We previously showed that the enzyme neprilysin reduces islet amyloid deposition and thereby reduces β-cell apoptosis, by inhibiting fibril formation. Two other enzymes, matrix metalloproteinase (MMP)-2 and MMP-9, are extracellular gelatinases capable of degrading another amyloidogenic peptide, Aβ, the constituent of amyloid deposits in Alzheimer disease. We therefore investigated whether MMP-2 and MMP-9 play a role in reducing islet amyloid deposition. MMP-2 and MMP-9 mRNA were present in mouse islets but only MMP-9 activity was detectable. In an islet culture model where human IAPP (hIAPP) transgenic mouse islets develop amyloid but nontransgenic islets do not, a broad spectrum MMP inhibitor (GM6001) and an MMP-2/9 inhibitor increased amyloid formation and the resultant β-cell apoptosis. In contrast, a specific MMP-2 inhibitor had no effect on either amyloid deposition or β-cell apoptosis. Mass spectrometry demonstrated that MMP-9 degraded amyloidogenic hIAPP but not nonamyloidogenic mouse IAPP. Thus, MMP-9 constitutes an endogenous islet protease that limits islet amyloid deposition and its toxic effects via degradation of hIAPP. Because islet MMP-9 mRNA levels are decreased in type 2 diabetic subjects, islet MMP-9 activity may also be decreased in human type 2 diabetes, thereby contributing to increased islet amyloid deposition and β-cell loss. Approaches to increase islet MMP-9 activity could reduce or prevent amyloid deposition and its toxic effects in type 2 diabetes.  相似文献   

13.
The present study evaluated the anticancer potential of celastrol through down-regulation of matrix metalloproteinase-2 (MMP-2) and MMP-9. HeLa cells were incubated with different concentrations of celastrol (1, 10 and 100 µM) for 48h. Doxorubicin was used as a reference drug. Cancer cell migration, apoptosis, cell viability and mitochondrial fragmentation were evaluated following celastrol treatment. In addition, the expression level of MMP-2, MMP-9 and caspase-3 was evaluated following celastrol treatment. HeLa cell viability was 94.1 ± 7, 53.4 ± 4 and 36.3 ± 2% at 1-100 µM of celastrol, respectively. Apoptotic cell numbers were increased, and inhibition of larger wounds in cancer cells was observed following celastrol treatment. Celastrol-treated cells showed condensed nuclei and clumped mitochondria. Reduced expression of MMP-2 and MMP-9 and increased expression of caspase-3 were observed following celastrol treatment. Based on the experimental results, we are concluding that the celastrol was effective against HeLa cervical cancer cells.  相似文献   

14.
Behçet disease (BD) is a chronic, inflammatory, and multisystemic condition with an uncertain pathogenesis. One of the major immunologic findings in BD pathogenesis is increase in activity of neutrophil. An increase in the cytosolic free Ca2+ [Ca2+]i concentration that induces Ca2+ signaling is an important step that participates in the neutrophil activation and reactive oxygen species production that leads to tissue damage in body cells. We aimed to investigate the effects of colchicine on oxidative stress and Ca2+ release in serum and neutrophil of BD patients with active and inactive periods. Twelve Behçet patients (6 active and 6 inactive) and 6 control subject were included in the study. Disease activity was considered by clinical findings. Serum and neutrophil samples were obtained from the patients and control subjects. Neutrophils from patients with active BD were divided into three subgroups and were incubated with colchicine, verapamil + diltiazem, and colchicine + verapamil + diltiazem, respectively. Erythrocyte sedimentation rate, leucocytes counts, serum C-reactive protein, neutrophil, and serum lipid peroxidation and intracellular Ca2+ release levels were higher in active and inactive groups than in the control group, although their levels were lower in active group than in inactive group. However, neutrophil Ca2+ release levels were decreased in colchicine, verapamil + diltiazem, and colchicine + verapamil + diltiazem groups group compared to active group. Serum glutathione, vitamin A, vitamin E, and β-carotene concentrations were lower in active and inactive groups than in the control group, although serum vitamin E and β-carotene concentrations were higher in the inactive group than in the active group. Neutrophil and serum glutathione peroxidase activity within the three groups did not change. In conclusion, we observed the importance of Ca2+ influx into the neutrophils and oxidative stress in the pathogenesis and activation of the patients with BD. Colchicine induced protective effects on oxidative stress by modulating Ca2+ influx in BD patients.  相似文献   

15.
To test whether the peripheral macrophage functions as an early index of oxygen free radical release in association with the development of IgA nephropathy (IgAN), we studied female Lewis rats. IgAN was produced by treatment over 8 weeks with 0.1% bovine gamma globulin (BGG) in drinking water, followed by three daily intravenous injections of BGG, 1 mg/dose. Fifteen rats were divided randomly into three groups: control, IgAN, and IgAN fed vitamin E 100 IU/kg chow. At the end of the treatment period, rats were placed in individual metabolic cages for 24-h urine collections and then anesthetized with Inactin (100 mg/kg BW) for aspiration of peritoneal macrophages. The results (means ± SD) extended our previous data in male rats, confirming that the elevated proteinuria of IgAN (3.62 ± 0.79 mg/day) was significantly reduced with vitamin E treatment (2.59 ± 0.28 mg/day) in female rats (P< 0.002) More importantly, we indicated for the first time that oxygen free radicals' production by peritoneal macrophages in IgAN was significantly reduced by vitamin E: 1.58 ± 0.91 nmol/106cells/15 min in the untreated group vs 3.28 ± 0.54 nmol/106cells/15 min in the vitamin E-treated group (P< 0.05).  相似文献   

16.
Hand‐reared grey‐faced petrel (Pterodroma macroptera gouldi) chicks (Order Procellariformes) that were subjected to a standardised blood sampling protocol immediately before they fledged showed a reduced corticosterone response compared to parent‐raised chicks. Serum corticosterone concentrations were lower in hand‐reared than parent‐reared birds 30 and 60 min after handling was initiated (21.5±6.7 vs. 105.4±7.4 ng/ml at 30 min, and 11.3±3.6 vs. 93.8±11.4 ng/ml at 60 min, respectively). The total integrated corticosterone response and the response corrected for initial corticosterone concentrations were similarly lower in hand‐reared than parent‐reared birds (927±489 vs. 4639±1924 ng/ml.min, and 529±352 vs. 4110±1896 ng/ml.min, respectively). Habituation to handling associated with hand‐rearing, which is expressed as a subdued corticostrone response, is likely to reduce the physiological stress associated with the translocation and reintroduction of these birds. However, the longer‐term consequences of this attenuated response remain unclear. Zoo Biol 0:1–8, 2005. © 2005 Wiley‐Liss, Inc.  相似文献   

17.
Deposition of human islet amyloid polypeptide (hIAPP, also known as amylin) as islet amyloid is a characteristic feature of the pancreas in type 2 diabetes, contributing to increased β-cell apoptosis and reduced β-cell mass. Matrix metalloproteinase-9 (MMP-9) is active in islets and cleaves hIAPP. We investigated whether hIAPP fragments arising from MMP-9 cleavage retain the potential to aggregate and cause toxicity, and whether overexpressing MMP-9 in amyloid-prone islets reduces amyloid burden and the resulting β-cell toxicity. Synthetic hIAPP was incubated with MMP-9 and the major hIAPP fragments observed by MS comprised residues 1–15, 1–25, 16–37, 16–25, and 26–37. The fragments 1–15, 1–25, and 26–37 did not form amyloid fibrils in vitro and they were not cytotoxic when incubated with β cells. Mixtures of these fragments with full-length hIAPP did not modulate the kinetics of fibril formation by full-length hIAPP. In contrast, the 16–37 fragment formed fibrils more rapidly than full-length hIAPP but was less cytotoxic. Co-incubation of MMP-9 and fragment 16–37 ablated amyloidogenicity, suggesting that MMP-9 cleaves hIAPP 16–37 into non-amyloidogenic fragments. Consistent with MMP-9 cleavage resulting in largely non-amyloidogenic degradation products, adenoviral overexpression of MMP-9 in amyloid-prone islets reduced amyloid deposition and β-cell apoptosis. These findings suggest that increasing islet MMP-9 activity might be a strategy to limit β-cell loss in type 2 diabetes.  相似文献   

18.
《Bone and mineral》1989,5(2):117-128
It is not known if the effects of vitamin D deficiency on chick bone are due to direct actions of the vitamin or if they are secondary to other changes, such as hypocalcemia. Day-old cockerels were fed either a rachitogenic diet containing no Ca (−D-Ca), 1.4% Ca (−D), or 3% Ca (−DHiCa) and given corn oil (−D groups) or vitamin D3 in corn oil (+D and + D-Ca) p.o. for up to 21 days. Radii were harvested and incubated for 6–8 h in a defined medium. Medium samples were taken every 2 h and analysed for Ca, P1 and lactate. Some bones were incubated in a respirometer to measure O2 consumption. Compared to +D, −D birds showed evidence of D deficiency by decreased plasma Ca concentration (33%), bone and body weight (43%) and Ca release from bone (70%) and by histological changes in bone characteristic of rickets. Increases were seen in total and bone alkaline phosphatase activity in plasma (270 and 706%, respectively), Pi release (23%), O2 consumption (23%) and lactate production (52%) by the −D radii. The marked hypocalcemia seen in the −D chicks did not occur in −DHiCa birds. Nevertheless, bone and body weights were decreased in this group and bone lactate production, O2 consumption and total and bone alkaline phosphatase in plasma were increased. Rachitic bone lesions were only partially corrected by the high-Ca diet. Release of Ca and Pi from the −DHiCa bone? was not different than from +D radii. Comparing +D-Ca and −D-Ca groups with +D chicks, both were hypocalcemic with decreased bone weight, body weight and bone Ca release, while showing elevated lactate production and Pi release. The only difference between the +D-Ca and −D-Ca groups was a 50% decrease in Ca release by −D-Ca bone. The results suggest that in chicks: (1) some, but not all, of the effects of vitamin D deficiency on bone can be corrected by normalizing plasma Ca and (2) evaluation of the effects of vitamin D deficiency on bone may require hypocalcemia, since some responses are masked by normocalcemia.  相似文献   

19.
目的:研究血清基质金属蛋白酶-9(MMP-9)水平与急性脑梗死(ACI)溶栓后出血转化(HT)的相关性及其预测意义。方法:选择2014年2月到2017年6月在承德医学院附属医院神经内科诊治的ACI患者130例作为研究对象。根据患者是否存在溶栓后HT将其分成HT组(65例)和NHT组(65例),两组均根据患者的实际病情给予个性化的治疗,对比两组患者实验室指标、血清MMP-9水平、美国国立卫生研究院卒中量表(NIHSS)评分,随访6个月后,记录死亡人数及Barthel指数,并分析患者血清MMP-9水平与其NIHSS评分、Barthel指数、低密度脂蛋白胆固醇(LDL-C)及总胆固醇(TC)水平的相关性。结果:HT组LDL-C及TC水平均低于NHT组(P0.05)。HT组患者在溶栓前、溶栓后3 d、溶栓后7 d的血清MMP-9水平、NIHSS评分均高于NHT组(P0.05)。随访6个月后,HT组的死亡率高于NHT组,而Barthel指数低于NHT组(P0.05)。根据Spearman法分析相关性发现,患者血清MMP-9水平与其NIHSS评分呈正相关,而与Barthel指数、LDL-C及TC水平呈负相关(P0.05)。结论:血清MMP-9水平与ACI溶栓后HT具有紧密的关联,有助于更好地预测患者的病情及预后,临床上可考虑在治疗ACI溶栓后HT时监测MMP-9水平,从而获得更加精准的辅助性数据参考。  相似文献   

20.
Chinese hamster cells in culture were synchronized, collected at metaphase, homogenized to release the chromosomes, and the chromosomes fractionated in a sucrose gradient using a zonal centrifuge with an A12 zonal rotor. Chromosomes in the separated fractions as well as in control metaphase spreads were quantitatively classified into five easily distinguished groups, according to individual measurements of length and centromeric index. For each zonal fraction, chemical determinations were made of the amount of DNA per average chromosome. Using the group compositional data for each fraction, the amount of DNA per average chromosome in each of the groups was then calculated to be: Group I (chromosomes 1, 2)= 1.00 ± 0.14 pgm/chromatid; Group II (chromosomes 4, X, 5) -0.39 ± 0.05 pgm/chromatid; Group III (chromosomes Y, 6, 7, 8)=0.24 ± 0.04 pgm/chromatid; Group IV (chromosomes 9, 10, 11)=0.13 ± 0.004 pgm/ chromatid; and Group V (a small marker in this cell line)=0.06 pgm/ chromatid. These values are in good agreement with the literature values for relative chromosomal DNA content derived from cytospectrophotometric measurements of fuelgen stained hamster metaphase spreads. They indicate that unlike the case for human chromatids the amount of DNA found in hamster chromatids is not directly proportional to the chromatid length.

The larger chromosomes contain more DNA per unit length than smaller chromosomes. The magnitude of this effect is considerably greater than that which may be ascribable to centromeric constriction.  相似文献   

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