Perioperative matrix metalloproteinase inhibition therapy does not impair wound or anastomotic healing

Matrix metalloproteinases (MMPs) catalyze the degradation of collagen and extracellular matrix. They play a role in pathologic states including malignancy, in which they facilitate invasion and metastasis. MMP inhibition has been shown to block neoplastic invasion and improve survival in animal models of malignancy. Concern about the effects of MMP inhibitors on wound and anastomotic healing may limit their potential use in the perioperative period to prevent local and systemic showering of cancer cells from surgical manipulation. We sought to assess the safety of perioperative administration of an MMP inhibitor (BB-94) with respect to skin and bowel healing in a rat model. Absorption of BB-94 was confirmed through high-pressure liquid chromatography and mass spectroscopy of sera from treated animals. Bowel bursting pressure in all animals increased almost 10-fold between 4 and 14 days. Two-way analysis of variance showed no significant difference in bowel bursting pressure between control and treatment animals over time. There was a significant increase in the collagen content of skin specimens of all animals combined between 4 and 28 days. Similarly, all animals showed an increase in bowel collagen between 4 and 28 days. There was no significant difference in skin or bowel collagen concentrations between control and treatment animals over time. Perioperative treatment with MMP inhibition does not impair wound or enteric healing in a rat model of laparotomy and small bowel resection. MMP inhibitors are safe for use as adjuvant therapy after resection for cancer. Presented at the Sixteenth Annual SSAT/Ross Residents and Fellows Research Conference, May 19, 2001; and at the Forty-Second Annual Meeting of The Society for Surgery of the Alimentary Tract, Atlanta, Georgia, May 20–23, 2001 (poster presentation). Supported by the Edward D. Churchill, M.D. Resident Research Fellowship, Harvard Medical School, Boston, Massachusetts.     

Attenuating tumor necrosis factor alpha does not ameliorate other cytokine and peroxidase products during sepsis

BACKGROUND: Recent trials utilizing single anticytokine agents have shown no consistent survival benefit in improving the outcome of sepsis. Since an entire cascade of mediators contributes to the underlying pathophysiology, it is not surprising that monotherapy has proven unsuccessful. The purpose of this study was to measure the effects of attenuating tumor necrosis factor (TNF)alpha early in sepsis. METHODS: Three groups of Sprague-Dawley rats were studied. All animals were infused with live Escherichia coli, with group I and group II rats additionally receiving a matrix metalloproteinase inhibitor. Serum levels of TNFalpha, interleukin (IL)-6, malondialdehyde (MDA), and lipid hydroperoxide (LOOH) were compared. RESULTS: TNFalpha showed a significant decrease, yet IL-6, MDA, and LOOH (markers of sepsis) levels remained abnormally elevated. CONCLUSION: Despite significantly attenuating TNFalpha, the septic response continued. This supports the concept that in sepsis, monotherapy directed at attenuating a single cytokine cannot overcome the tissue-damaging effects of an entire cascade of mediators.     

Effect of tumor necrosis factor alpha,interferon gamma,and interleukin-4 on bacteria-enterocyte interactions

BACKGROUND: Little is known about the mechanisms involved in bacterial translocation from the intestinal lumen to extraintestinal sites. Because the cytokine cascade associated with sepsis, inflammation, and trauma has been shown to affect intestinal epithelial permeability, experiments were designed to clarify the effects of selected cytokines on bacterial adherence to and internalization by cultured HT-29 and Caco-2 enterocytes. METHODS: Mature, confluent enterocytes were pretreated 48 to 72 h with tumor necrosis factor alpha (TNF-alpha), interferon gamma, (IFN-gamma), or interleukin-4 (IL-4). Adherence of Listeria monocytogenes, Salmonella typhimurium, Proteus mirabilis, and Escherichia coli was measured by enzyme-linked immunosorbent assay and bacterial internalization was quantified by the gentamicin protection assay. Enterocyte permeability was measured by transepithelial electrical resistance and by flux of 40-kDa fluorescent dextran. Bacterial transmigration across confluent enterocytes was measured using enterocytes cultivated on permeable supports. RESULTS: TNF-alpha, IFN-gamma, and IL-4 had variable effects on bacterial adherence to HT-29 and Caco-2 enterocytes, although the most consistent finding was increased bacterial adherence associated with INF-gamma. However, none of these cytokines had a noticeable effect on bacterial internalization by either Caco-2 or HT-29 enterocytes. In addition, none of these cytokines had a noticeable effect on the permeability of confluent enterocytes as measured by transepithelial electrical resistance or dextran flux. Bacterial transmigration across confluent HT-29 enterocytes was not altered by TNF-alpha, IFN-gamma, or IL-4; however, IL-4 consistently decreased bacterial transmigration across confluent Caco-2 enterocytes. CONCLUSIONS: IFN-gamma may augment the epithelial adherence of selected species of enteric bacteria, and IL-4 may act as a barrier-sustaining agent to decrease bacterial migration across the intestinal epithelium.     

Inhibitory effects of tumor necrosis factor alpha on fracture healing in rats

Fracture healing, which involves a cascade of biological tissue responses, may be affected by various biochemical substances. One of these substances is tumor necrosis factor alpha (TNF). Studies were made on the effects of TNF on healing of fractured ribs of rats. Fracture healing was inhibited by daily administration of recombinant human TNF (400 μg/kg body weight per day, intraperitoneally) after fracture. The rate of union on day 20 was significantly lower in the TNF-treated group (4/18, 22.2%) than in the control group (14/18, 77.8%) (p < 0.001 by Chi-square test). Histological examination showed that TNF inhibited cartilagenous callus formation. On day 10, cartilage was seen in the gap zone and under the periosteum in the control group, but no cartilage formation was observed in the gap zone in 9 of 12 specimens from the TNF-treated group. On day 20, the fracture ends were united by newly formed bone in the control group, but mature fibrous tissue was seen in the gap zone, and bony or cartilagenous union was not achieved in the TNF-treated group. These results show that TNF inhibits cartilage formation in the early phase of bone induction in fracture healing and suggest that this effect of TNF is due to its inhibition of differentiation of mesenchymal cells into chondroblasts.     

Roles of tumor necrosis factor alpha on sperm acrosin activity and acrosome reaction

Aim: To study the roles of tumor necrosis factor alpha (TNF-a)on the sperm acrosin activity and acrosome reaction. Methods:The sperm acrosin activity was tested by the method of BAEE/ADH Unity and the acrosome reaction by the Triple-stain technique. Results: TNF-a decreased the sperm acrosin activityand acrosome reaction (P＜0.01, P＜0.01, respectively);     

肿瘤坏死因子-α对人脐静脉血管内皮细胞结构和功能的影响

目的 观察人肿瘤坏死因子-α(TNF-α)对人脐静脉血管内皮细胞EA.hy926结构和功能的影响,并探讨其作用机制.方法 培养人脐静脉血管内皮细胞EA.hy926,分组加入1、10、100 μg/L TNF-α培养24 h,或加入100 μg/L TNF-α培养3、8、12、24 h,Western blot检测细胞中血管扩张刺激磷蛋白(VASP)的表达水平;实时定量聚合酶链反应(Real-time PCR)检测细胞中VASPmRNA的表达水平,流式细胞仪检测细胞凋亡,透射电子显微镜观察细胞超微结构的变化.结果 TNF-α干预24h不同浓度组VASP mRNA水平分别为0.993±0.045(对照组)、0.801±0.022(1 μg/L)、0.626 ±0.018(10 μg/L)、0.529±0.017(100 μg/L);蛋白水平分别为0.849±0.021(对照组)、0.788±0.028(1μg/L)、0.364 ±0.018(10 μg/L)、0.317±0.023(100 μg/L);细胞凋亡率分别为(2.5±1.0)％(对照组)、(14.0±1.1)％(1 μg/L)、(24.4±3.8)％(10 μg/L)、(36.0±2.5)％(100 μg/L).100 μg/L TNF-α干预不同时间组VASP mRNA表达分别为0.829 ±0.051(3 h)、0.741±0.029(8 h)、0.669 ±0.026(12 h)、0.528 ±0.017(24 h),蛋白水平分别为0.528±0.201(3 h)、0.470±0.016(8 h)、0.299±0.015(12 h)、0.298±0.016(24 h);细胞凋亡率分别为(5.4±0.9)％(3 h)、(11.4±1.2)％(8 h)、(21.2±1.4)％(12 h)、(36.3±2.1)％(24 h).VASPmRNA及蛋白水平均呈时间及剂量依赖表达降低(P＜0.05),细胞凋亡率呈时间及剂量依赖升高(P＜0.05).结论 TNF-α通过破坏血管内皮细胞结构和功能导致血管内皮细胞通透性增高,呈时间与剂量依赖性.     

Influence of uremia and hemodialysis on circulating interleukin-1 and tumor necrosis factor alpha

Interleukin-1 (IL-1) and tumor necrosis factor alpha (TNF alpha) were determined in the plasma of long-term hemodialysis (HD) patients and uremic (UR) patients undergoing their first dialysis session using either cellulosic (CUP) or synthetic (PAN-AN 69) membrane-equipped dialyzers. In long-term HD patients, plasma IL-1 and TNF alpha levels were significantly increased compared to their levels in normal subjects. During a single dialysis session, a significant increase in IL-1 but not in TNF alpha was observed. In not yet dialyzed UR patients, IL-1 plasma levels did not differ from those observed in normal subjects. By contrast, TNF alpha was found significantly increased although less than in long-term HD patients. During the first dialysis session, no significant increase was observed in the levels of either monokine. Lastly, regardless of the group of patients, no significant influence of the dialysis membrane could be detected, suggesting that the observed changes are not exclusively secondary to the activation of complement. Altogether, these results suggest that the passage of the blood through the extracorporeal dialysis circuit triggers the secretion of IL-1 and further exacerbates that of TNF alpha by monocytes. The presence of increased TNF alpha in the plasma of first-dialysis UR patients suggests that factors unrelated to dialysis contribute to the activation of monocytes in these patients. Lastly, the concomitant presence of IL-1 and TNF alpha in the plasma of long-term HD patients could be responsible for some of the clinical features observed in these patients, and provides strong evidence favoring the concept that HD can be assimilated to a recurrent acute-phase inflammatory response.     

Human mesangial cells synthesize interleukin 1 alpha but not interleukin 1 beta, interleukin 1 receptor antagonist, or tumour necrosis factor.

There is controversy over whether mesangial cells synthesize and release IL-1 and TNF, and many of the positive experiments were performed before specific reagents and molecular probes were available. Consequently we have stimulated human mesangial cells using protocols known to stimulate the synthesis of other cytokines. No mRNA for IL-1 beta or TNF could be detected in quiescent or proliferating mesangial cells irrespective of whether they had been exposed to cytokines or not. In contrast mRNA for IL-1 alpha was detected in cells stimulated with IL-1 beta 10 ng/ml or with TNF 500 ng/ml; IL-1 alpha was also detected in cell lysates from stimulated mesangial cells. We could not detect mRNA for IL-1 receptor antagonist in any of the cell preparations. These results suggest that mesangial cells are unlikely to be a major source of IL-1 beta or TNF.     

Protective effect of tumor necrosis factor alpha antibody on experimental necrotizing enterocolitis in the rat

Background

Necrotizing enterocolitis (NEC) is a common and devastating disorder of premature infants. Elevated proinflammatory cytokines, especially tumor necrosis factor α (TNF-α), have been implicated in the pathogenesis of NEC. The aim of this study was to evaluate the effects of TNF-α on the inflammatory response in NEC by immunoneutralizing TNF-α with a selective antibody.

Methods

Neonatal Sprague-Dawley rats were divided in 3 groups: group 1 (n = 20), a NEC-like enterocolitis was induced by formula feeding, asphyxia, and cold exposure; group 2 (n = 9), animals were treated like in group 1 and additionally received TNF-α antibody intraperitoneally; and group 3 (n = 17), animals were dam-fed (controls). Animals were killed in case of imminent death or after 96 hours. Specimens from small bowel were processed for blinded histologic (H&E) and immunhistologic (myeloperoxidase [MPO]) analysis.

Results

In group 1, animals developed severe NEC (mean NEC score, 3.28 ± 0.32; mean MPO, 65.85 ± 9.46). In group 2, animals developed mild NEC (mean NEC score, 1.72 ± 0.41; mean MPO, 34.33 ± 9.69; P < .05). In group 3, no NEC was induced (mean NEC score, 0.0 ± 0; mean MPO, 6 ± 1.32; P < .05).

Conclusion

Tumor necrosis factor α antibody may have an attenuating effect on experimental NEC in rats.     

Effects of tumor necrosis factor alpha on parathyroid hormone-induced increases in osteoblastic cell cyclic AMP

Summary Tumor necrosis factor α (10⁻¹⁰–10⁻⁸M) had no effects on cyclic AMP production by the osteoblastic osteosarcomal cells, Saos-2 and G292, or normal rat calvarial cells. The cytokine did, however, inhibit the parathyroid hormone (PTH)-induced effect on cyclic AMP in the Saos-2 and normal rat osteoblastic cells. This inhibitory effect did not occur on prostaglandin E₂-induced cyclic AMP increases in the osteoblastic cells. Interleukin-1 (10 U/ml −100 U/ml) did not produce any effect on basal levels or PTH-induced cyclic AMP increases in these cells.     

Streptococcal exotoxin B increases interleukin-6, tumor necrosis factor alpha,interleukin-8 and transforming growth factor beta-1 in leukocytes

Previous reports have shown the presence of streptococcal erythrogenic exotoxin type B (ETB), leukocyte infiltration, interleukin-8 (IL-8), transforming growth factor-beta (TGF-β) and glomerular proliferation in renal biopsies from patients with acute post-streptococcal glomerulonephritis (APSGN). In addition, increased levels of plasma interleukin-6 (IL-6) and tumor necrosis factor alpha (TNFα), and urinary IL-6, have also been reported in this disease. To determine the effect of streptococcal proteins on leukocyte proliferation and leukocyte production of IL-6, TNFα, IL-8 and TGF-β1, we cultured human mononuclear leukocytes with ETB or ETB precursor (ETBP). After 24 h, 48 h and 96 h, culture supernatants were assessed for cytokines by enzyme-linked immunosorbent assay (ELISA), and for leukocyte proliferation by a monoclonal antibody anti-proliferating cellular nuclear antigen (PCNA). A significant increase in all cytokines was found in ETB- or ETBP-treated cultures when compared with controls. A polyclonal anti-ETB antibody diminished the cytokine stimulatory effect of ETB. An increased number of PCNA-positive cells was observed in ETB or ETBP treated cultures at 48 h and 96 h. Cytokine production and proliferation were not correlated. The stimulatory effect of streptococcal exotoxin B on leukocyte cytokine production may be relevant in renal tissue during the course of APSGN.     

肿瘤坏死因子-α对血管内皮细胞通透性影响的实验研究

目的：观察人肿瘤坏死因子-α（TNF—α）对人血管内皮细胞（EA.hy926）单层通透性的影响并初步探讨其作用机制。方法：测定异硫氰酸荧光素（FITC）标记的葡聚糖透过Transwell小室的荧光强度,以表示EA．hy926细胞单细胞层的通透性大小;激光共聚焦显微镜观察细胞骨架肌动蛋白（F—actin）和血管内皮钙黏蛋白（VE—cadherin）的形态分布;蛋白免疫印迹检测钙黏蛋白的表达。结果：与对照组比较,TNF-α使EA.hy926内皮细胞的通透性明显增加（P〈0．05）,诱导肌动蛋白重新分布及应力纤维形成,并使钙黏蛋白排列紊乱、断裂、细胞问裂隙形成增多。免疫印迹检测表明TNF-α减少钙黏蛋白表达呈剂量和时间依赖性。结论：TNF-α诱导内皮细胞通透性增高,其机制可能与其破坏内皮细胞屏障功能的完整性有关。     

Perioperative response of leptin and the tumor necrosis factor alpha system in morbidly obese patients. Influence of cortisol inhibition by etomidate

BACKGROUND: Leptin, tumor necrosis factor alpha (TNFalpha) and soluble TNFalpha receptors are secreted by the adipose tissue. Surgery induces a complex cytokine and neurohormonal response. The aim of our study was to investigate the perioperative response of leptin and the TNFalpha system in morbidly obese patients submitted to gastroplasty, and the possible involvement of cortisol in their responses. METHODS: Serum cortisol, adrenocorticotropic hormone (ACTH), leptin, TNFalpha and soluble TNFalpha receptor I were measured in 22 morbidly obese women (11 anesthetized with thiopental and 11 with etomidate, a well known inhibitor of cortisol synthesis). Samples were collected before anesthesia induction, just before surgical incision, and 2, 4, 6, 12, 24 and 48 h after the start of surgery. RESULTS: Baseline serum leptin correlated with body mass index (r=0.567, P=0.007). Baseline serum leptin and TNFalpha were higher than normal. Cortisol release was inhibited in the etomidate group with a subsequent higher stimulation of ACTH release. A statistically significant decrease in serum leptin levels was observed in both groups at 2, 4, 6 and 48 h, compared with basal values. A similar decrease in serum TNFalpha levels was observed in both groups, but the decrease reached significance only in the etomidate group. Serum soluble TNFalpha receptor I did not decrease. No differences were found between the two groups in leptin, TNFalpha or soluble TNFalpha receptor I concentrations at any time. CONCLUSION: Serum leptin and TNFalpha levels decrease in obese patients during gastroplasty. Transitory inhibition of cortisol release does not alter this response.     

Association of circulating transforming growth factor beta, tumor necrosis factor alpha and basic fibroblast growth factor with restenosis after transluminal angioplasty.

OBJECTIVES: To assess prospectively the early time course of Transforming Growth Factor beta-1 (TGFbeta-1), basic Fibroblast Growth Factor (bFGF) and Tumor Necrosis Factor alpha (TNFalpha) as possible contributors to restenosis development after angioplasty. DESIGN: Prospective Study. METHODS: The levels of the soluble forms of these factors in the early response to Percutaneous Transluminal Angioplasty (PTA) in the arteries of the lower limb were prospectively assessed. 32 patients with peripheral arterial occlusive disease (PAOD), presenting with intermittent claudication (Fontaine stage IIb) were scheduled for angioplasty treatment. Serum levels of TGFbeta-1, TNFalpha and bFGF were assessed before intervention, 15 and 60 minutes after, 24 hours after as well as 2 and 4 weeks after intervention. We compared the distribution patterns between patients treated with balloon angioplasty and patients who required secondary stent implantation. Endpoint was the development of restenosis within 6 months after interventional treatment, defined as a lumen diameter reduction of more than 50% by ultrasound measurement compared to the result after PTA. RESULTS: The patients who later developed restenosis had significantly higher levels of TGFbeta-1 at 15 minutes, 24 hours and 2 weeks after PTA (p<0.05). TNFalpha and bFGF were only detected in a few patients and no significant change of serum levels was observed. CONCLUSION: The results demonstrate a possible role of TGFbeta-1 in the formation of restenosis after PTA.     

胰岛素抵抗、TNF-α、PAI-1与妊高征相关性的研究

目的:探讨胰岛素抵抗、肿瘤坏死因子(tumor necrosis factor-alpha,TNF-α)、纤溶酶原激活物抑制物-1(plasminogen activator inhibitor type 1,PAI-1)与妊高征发病的相关性。方法:选择天津市中心妇产科医院住院的先兆子痫患者15例,轻-中度妊高征患者12例,正常孕晚期妇女10例,抽取空腹静脉血测定葡萄糖、胰岛素、TNF-α和 PAI-1水平,计算胰岛素敏感性指数,比较3组患者的胰岛素敏感性、TNF-α和 PAI-1的差异。结果:先兆子痫组空腹血胰岛素值高于对照组(P<0.05),代表胰岛素抵抗的胰岛素敏感性指数亦明显高于轻-中度妊高征组和对照组(P<0.01);3组患者血清 TNF-α值无明显差异;先兆子痫组 PAI-1值明显高于轻-中度妊高征组和对照组(P<0.001和 P<0.01)。结论:胰岛素抵抗和 PAI-1在妊高征的发生、发展中具有重要意义。     

肿瘤坏死因子alpha上调人结肠癌细胞株突变型p53蛋白的表达

目的：研究TNF-alpha对人结肠癌细胞株HT-29及HCT116 p53表达的影响。方法：给予人结肠癌细胞株HT-29（表达突变型p53蛋白）及HCT116（表达野生型p53蛋白）不同浓度的TNF-alpha刺激后,应用细胞免疫荧光及实时荧光定量PCR检测突变型p53蛋白表达及p53 mRNA水平的改变。结果：免疫荧光显示TNF-alpha刺激后能显著提高HT-29细胞核突变型p53蛋白的表达（P〈0.05）,而对表达野生型p53的HCT116的p53水平无明显改变。实时荧光定量PCR结果表明TNF-alpha刺激对HT-29及HCT-116的p53 mRNA水平无明显改变。结论：TNF-alpha能显著上调HT-29突变型p53蛋白的表达,但是该上调作用并不是发生于转录水平。TNF-alpha刺激对表达野生型p53的HCT116细胞株p53水平无明显改变。