Differential Immunohistochemical Expression of Syndecan-1 and Tumor Necrosis Factor Alpha in Colonic Mucosa of Patients with Crohn’s Disease

Tumor necrosis factor alpha (TNFα) in intestinal mucosa plays a key role in the inflammation characterizing Crohn’s disease (CD). Moreover, adhesion molecule syndecan-1 mediates the maintenance of mucosal integrity and supports tissue repair. Therefore, our aim in this study was to correlate simultaneous expression of TNFα and syndecan-1 in patients affected by CD. Biopsies from 10 patients with CD of large bowel and 10 subjects with irritable bowel syndrome (controls) were studied by immunohistochemical detection of both TNFα and syndecan-1 on successive serial sections. Overall labeling index (OLI) was indicated by the percentage of positive stromal (i.e., nonepithelial) cells/1000 counted in randomized fields, whereas selected labeling index (SLI) was represented by the simultaneous evaluation of both molecules in a same single selected field of each specimen. TNFα and syndecan-1 OLI were significantly higher in CD compared with controls, while SLI showed an inverse relationship between the molecules in CD which was not observed in controls. Epithelial syndecan-1 cytoplasmatic staining of superficial epithelium was associated with loss of basolateral staining in the crypts and high stromal TNFα in CD. In conclusion, TNFα and syndecan-1 expression is increased in the intestinal mucosa of patients with CD. However, the expression of the two molecules is inversely related when a single field is considered, these data supporting the possibility of a downregulation exerted by TNFα.     

川芎嗪逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用及机制研究

目的： 研究川芎嗪（Ligustrazine）逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用,以及对肿瘤细胞中耐药相关蛋白ABCB1、ABCC1和ABCG2表达的影响。方法： MTS法研究川芎嗪逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的IC₅₀值和逆转耐药系数;流式细胞实验研究川芎嗪对脂肪细胞介导的耐药卵巢癌细胞的凋亡水平的影响;划痕实验研究川芎嗪对脂肪细胞介导的耐药卵巢癌细胞的迁移能力的影响;Western Blot研究川芎嗪对肿瘤细胞中耐药相关蛋白ABCG1、ABCC1和ABCG2表达水平。结果： 川芎嗪能够逆转脂肪细胞介导的卵巢癌奥沙利铂耐药,其逆转耐药系数为2.8;川芎嗪能够增加脂肪细胞和肿瘤细胞共培养体系下肿瘤细胞的凋亡;川芎嗪能够抑制脂肪细胞和肿瘤细胞共培养体系下肿瘤细胞的迁移;川芎嗪能够减少肿瘤细胞中耐药相关蛋白ABCB1、ABCC1和ABCG2的表达。结论： 川芎嗪能够逆转脂肪细胞介导的卵巢癌奥沙利铂耐药的作用且其机制与减少耐药相关蛋白ABCB1、ABCC1和ABCG2的表达有关。     

Adipocyte dysfunction in rats with streptozotocin–nicotinamide‐induced diabetes

Administration of streptozotocin (STZ) and nicotinamide (NA) to adult rats allows for the induction of mild diabetes. However, this experimental model has not been fully characterized. This study was undertaken to determine the metabolic and secretory activity of adipose tissue in rats with STZ‐NA‐induced diabetes. Experiments were performed using epididymal adipocytes isolated from control and mildly diabetic rats. Lipogenesis, glucose transport as well as glucose and alanine oxidation, lipolysis, anti‐lipolysis, cAMP levels and adipokine secretion were compared in cells isolated from the control and diabetic rats. Lipogenesis, glucose transport and oxidation were diminished in the adipocytes of diabetic rats compared with the fat cells of control animals. However, alanine oxidation appeared to be similar in the cells of non‐diabetic and diabetic animals. Lipolytic response to low epinephrine concentrations was slightly increased in the adipocytes of diabetic rats; however, at higher concentrations of the hormone, lipolysis was similar in both groups of cells. The epinephrine‐induced rise in cAMP levels was higher in the adipocytes of STZ‐NA‐induced diabetic rats, even in the presence of insulin. Lipolysis stimulated by dibutyryl‐cAMP did not significantly differ, whereas anti‐lipolytic effects of insulin were mildly decreased in the cells of diabetic rats. Secretion of adiponectin and leptin was substantially diminished in the adipocytes of diabetic rats compared with the cells of control animals. Our studies demonstrated that the balance between lipogenesis and lipolysis in the adipose tissue of rats with mild diabetes induced by STZ and NA is slightly shifted towards reduced lipid accumulation. Simultaneously, adiponectin and leptin secretion is significantly impaired.     

Effect of humoral factors from hPDLSCs on the biologic activity of hABCs

Oral Diseases (2012) 18, 537–547 Objective: The human periodontal ligament stem cells (hPDLSCs) and human alveolar bone–derived stromal cells (hABCs) seem to be closely involved in the maintenance of alveolar bone in an anatomically indirect manner; however, there is little study on this matter. Therefore, the effect of hPDLSCs on the osteoclastogenic, osteogenic, and adipogenic differentiation of hABCs was evaluated, focusing on the humoral factors released by hPDLSCs. Materials and methods: Human periodontal ligament stem cells and hABCs were isolated and characterized. hPDLSCs were indirectly cocultured to observe the in vitro effect of humoral factors released from hPDLSCs on the osteoclastogenic, osteogenic, and adipogenic differentiation of hABCs. Human gingival fibroblasts (hGFs) were utilized as positive control. Results: Isolated cells demonstrated the presence of stem cells within. Indirect coculture of hPDLSCs greatly inhibited osteoclastogenesis by hABCs. Osteogenesis/adipogenesis of hABCs was also inhibited by indirect coculture with hPDLSC. The magnitude of regulatory effect from hPDLSCs was significantly greater than that of hGFs. Conclusions: Humoral factors released from hPDLSCs seemed to modulate the differentiation of hABCs, and the osteoclastogenic, osteogenic, and adipogenic differentiation of hABCs was all inhibited, suggesting the potential role of hPDLSCs in the maintenance of the alveolar bone.     

机械加载改善高脂饮食诱导的肥胖相关骨丢失

目的 探究脉冲式关节机械加载对高脂饮食诱导的肥胖小鼠骨丢失的改善作用。方法 将 45只雌性C57BL/6小鼠随机分为普通饮食对照组（Sham组）、高脂饮食模型组（HF组）和高脂加载治疗组（HF+L组）,每组 15只。HF组和 HF+L组高脂饮食喂养 4周后,HF+L组进行 4周的机械加载治疗（加载条件为 1 N,10 Hz,3 min/d,每周连续加载 5 d）。治疗结束后测量 3组小鼠体质量指数（BMI）、全身体脂含量和双侧股骨的骨密度。使用 HE染色和MacNeal’s染色分析观察股骨的组织病理改变,使用 Western blot检测成骨生成相关蛋白［碱性磷酸酶（ALP）、Runt相关转录因子 2（RUNX2）］和脂肪生成相关蛋白［过氧化物酶体增殖物激活受体 γ（PPARγ）、CCAAT/增强子结合蛋白 α（C/EBPα）］的表达。结果 与 Sham组相比,HF组小鼠的体脂含量和 BMI升高,骨密度变化率和骨量变化率显著下降,骨小梁面积明显减少,骨髓脂肪细胞增多。机械加载治疗后,HF+L组的骨密度、骨小梁面积比 HF组明显升高,脂肪细胞的数目和面积比 HF 组显著降低（P＜0.05）。Western blot 分析结果表明,HF+L 组与 HF 组相比,ALP 和RUNX2的表达显著升高,C/EBPα和 PPARγ的表达明显降低（均P＜0.05）。结论 机械加载能够有效缓解由肥胖引起的低骨密度和低骨量,其治疗作用可能通过促进成骨分化和抑制脂肪生成来改善骨丢失。     

Antilipolytic effects of 1,8‐naphthyridine derivatives β‐adrenoceptor antagonists in rat white adipocytes

The rat fat cell β‐adrenoceptors were investigated by studying the effects of new 1,8‐naphthyridine derivatives synthesized starting from 7‐amino‐2‐chloro‐3‐phenyl‐1,8‐naphthyridine on lipolysis induced by isoprenaline, and alprenolol. Lipolysis induced by isoprenaline agonist was competitively antagonized by the 1,8‐naphthyridine analogue with a 7‐hydroxy‐2‐(4′‐methoxybenzylamine)‐6‐nitro‐3‐phenyl substituent designated as 3 . In contrast, 10, 50, and 100 μm of 7‐methoxy and 7‐ethoxy derivatives did not modify the concentration–response curve of isoprenaline. A rightward shift of the curve was, however, observed with 50 μm of a 7‐methoxy‐2‐(4′‐methoxybenzylamine)‐6‐amino‐3‐phenyl substituent designated as 10 . The selective β₁‐AR antagonist, 7‐hydroxy‐4‐morpholinomethyl‐2‐piperazino‐1,8‐naphthyridine slightly reduced isoprenaline‐induced lipolysis only at high doses. Alprenolol‐mediated lipolytic effect was antagonized by derivative 3 , 10 and the selective β₃‐AR antagonist SR 59,230A, but resistant to the selective β₁‐AR antagonist 7‐hydroxy‐4‐morpholinomethyl‐2‐piperazino‐1,8‐naphthyridine. The results provide preliminary pharmacological evidence for the antilipolytic effect of the newly synthesized 1,8‐naphthyridine derivatives on rat fat cells. The analogues designated as 3 and 10 were the most potent antagonists of this series.     

EGCG改善油酸诱导的SW872脂肪细胞胰岛素抵抗作用及机制

目的观察植物化学物表没食子儿茶素没食子酸酯(EGCG)对胰岛素抵抗SW872脂肪细胞葡萄糖转运、胰岛素敏感性及炎症因子表达作用。方法利用油酸处理脂肪细胞诱导胰岛素抵抗模型,给予不同剂量EGCG(25、50、100μmol/L)处理24 h,利用激光共聚焦显微镜检测2–脱氧葡萄糖标记的葡萄糖摄取、Western–blot检测葡萄糖转运因子4(GLUT4)蛋白表达、实时荧光定量逆转录多聚酶联反应(RT–q PCR)检测肿瘤坏死因子α(TNF–α)、白细胞介素6(IL–6)、C反应蛋白(CRP)mRNA表达,酶标记免疫吸附测定法(ELISA)检测培养液中TNF–α、IL–6、CRP蛋白含量。结果与对照组比较,模型组脂肪细胞葡萄糖摄取和GLUT4蛋白表达明显降低(P<0.05),TNF–α、IL–6、CRP mRNA明显升高(P<0.01),TNF–α、IL–6、CRP蛋白分泌量[分别为(161.3±14.2)、(121.6±13.6)、(1.82±0.17)]明显升高(P<0.01);与模型组比较,EGCG组脂肪细胞葡萄糖摄取和GLUT4蛋白表达明显增加(P<0.05),TNF–α、IL–6、CRP mRNA明显下降(P<0.01),低、中、高剂量EGCG组脂肪细胞TNF–α、IL–6、CRP蛋白分泌量[分别为(148.8±13.3)、(93.3±10.4)、(1.74±0.12)pg/m L,(131.4±11.3)、(85.5±14.1)、(1.53±0.15)pg/m L和(119.5±12.1)、(73.9±11.3)、(1.36±0.12)pg/m L]明显降低(P<0.01),呈剂量效应关系。结论 EGCG可促进脂肪细胞葡萄糖摄取和增强胰岛素敏感性,进而改善胰岛素抵抗,其机制可能与降低脂肪细胞炎症因子表达有关。     

CXC趋化因子配体14对高糖环境中脂肪细胞焦亡的影响

目的探讨CXC趋化因子配体14(CXCL14)对高糖暴露环境中脂肪细胞焦亡的影响。方法利用“鸡尾酒法”诱导3T3-L1细胞分化为成熟脂肪细胞,用5.5 mmol/L低糖(NG)或25 mmol/L高糖(HG)葡萄糖培养基培养脂肪细胞24 h;HG环境下用不同浓度CXCL14处理3T3-L1细胞不同时间。Western blot检测消化道皮肤素(GSDMD)、核苷酸结合寡聚化结构样受体蛋白3(NLRP3)、天冬氨酸蛋白水解酶-1(Caspase-1)蛋白、白细胞介素-6(IL-6)蛋白表达水平。实时荧光定量PCR检测GSDMD、NLRP3、白细胞介素-1β(IL-1β) mRNA转录水平。LDH测定试剂盒检测脂肪细胞上清液中乳酸脱氢酶(LDH)活力;Annexin V-FITC荧光检测细胞死亡情况;CCK-8法检测各组细胞增殖活力。结果高糖环境下脂肪细胞焦亡发生率升高,CXCL14处理可提高脂肪细胞增殖活力,但脂肪细胞焦亡相关指标却受到CXCL14浓度梯度的不同影响。50 nmol/L CXCL14处理可降低高糖环境下脂肪细胞GSDMD、NLRP3、IL-1β mRNA以及NLRP3蛋白的表达,下调脂肪细胞LDH活力,减少Annexin V-FITC荧光染色细胞死亡率,但25、100、200 nmol/L CXCL14对其焦亡的指标却呈反向趋势。并且50 nmol/L CXCL14干预后脂肪细胞NLRP3、Caspase-1蛋白随干预时间的延长呈先下降再上升趋势。结论CXCL14对高糖环境中脂肪细胞焦亡的影响与其浓度存在相关性。     

Corticosteroids as long-term regulators of the insulin effectiveness in mouse 3T3 adipocytes

Summary Since corticosteroid treatment is often accompanied by insulin resistance, we explored the role of corticosteroids in the regulation of the insulin effectiveness in cultured 3T3 (mouse) adipocytes. Exposure of the fat cells to dexamethasone or corticosterone (0–5 days) induced a time-, concentration-, and protein synthesis-dependent and reversible decrease in insulin binding and in basal and insulin-stimulated 2-deoxyglucose uptake. The decrease in binding (50%) was primarily due to a decrease in receptor affinity i. e. to an increase in the rate of dissociation of insulin from its receptors, and was independent from the effects of pH and temperature on the affinity. The reduction in the 2-deoxyglucose uptake (30–50%) was due to a decrease in the hexose transport capacity rather than to a decrease in the phosphorylation component of the 2-deoxyglucose uptake process. Lineweaver-Burk analysis revealed the dexamethasone induced a decrease in the apparent V_max of the transport system i. e. in the number or activity of the hexose transporters. The effect of dexamethasone seemed to be superimposed on that of long-term insulin treatment, suggesting a different mechanism. It is concluded that corticosteroids act as long-term regulators of the insulin effectiveness by influencing the rate at which insulin dissociates from its receptors and by altering the number or activity of the hexose transporters by a common mechanism, which differs from that of the long-term regulatory effect of insulin.     

Mineralocorticoid-stimulating activity of adipose tissue

Obesity is strongly associated with arterial hypertension. A positive correlation between obesity and plasma aldosterone levels has been observed by different investigators, suggesting that an abnormal secretion of aldosterone in obesity contributes to the development of arterial hypertension in obese subjects. The mechanisms proposed to explain this abnormal aldosterone production mainly involve the adipose renin-angiotensin system, an indirect effect of increased fatty acids, and direct adrenal stimulation by adipocyte secretory products. Indeed, adipose mineralocorticoid-stimulating activity was recently observed in isolated human adipocytes, suggesting a hitherto unknown direct involvement of adipose tissue in the regulation of blood pressure in obesity.