Heparin-binding epidermal growth factor-like growth factor gene disruption is associated with delayed intestinal restitution, impaired angiogenesis, and poor survival after intestinal ischemia in mice

Purpose

We have demonstrated that administration of heparin-binding epidermal growth factor-like growth factor (HB-EGF) protects the intestines from injury. The aim of the current study was to evaluate the effect of HB-EGF gene disruption on intestinal restitution, angiogenesis, and long-term survival after intestinal ischemia/reperfusion (I/R) injury.

Methods

HB-EGF (−/−) and wild-type HB-EGF (+/+) littermate mice were subjected to 45 minutes of superior mesenteric artery occlusion followed by reperfusion. Functional recovery of the gut permeability barrier was evaluated with Ussing chamber studies, and microvessel density was evaluated immunohistochemically. Animal survival was evaluated using the Kaplan-Meier method.

Results

Histologic damage after ischemia was significantly higher in HB-EGF (−/−) mice compared with HB-EGF (+/+) mice, associated with a significantly higher number of incompetent (nonhealed, nonresurfaced) villi indicative of delayed structural healing by restitution. HB-EGF (−/−) mice had increased intestinal permeability after intestinal I/R. HB-EGF (−/−) mice had significantly lower microvessel density at 3 and 7 days after I/R, indicating that HB-EGF gene deletion resulted in delayed onset of angiogenesis. Two-week mortality rates were significantly higher in HB-EGF (−/−) mice.

Conclusions

Endogenous HB-EGF significantly enhances healing by restitution, prolongs survival, and enhances angiogenesis in mice subjected to intestinal I/R injury. These findings support our hypothesis that HB-EGF administration may improve outcome in patients with intestinal I/R injury, including necrotizing enterocolitis.     

类肝素结合性表皮生长因子在人子宫内膜植入窗期的表达和意义

探讨类肝素结合性表皮生长因子 (HB-EGF)在人正常子宫内膜中的表达特点 ,评估其在子宫内膜的生长、分化及在植入窗期介导胚泡着床中的作用。采用免疫组织化学方法检测 5 6例正常子宫内膜 (1 6例增殖期 ,1 3例分泌早期 ,1 5例分泌晚期 ,1 2例植入窗期 )中 HB-EGF的表达及定位。结果 :HB-EGF在人各期子宫内膜均有表达 ,在植入窗期或分泌中期子宫内膜上皮细胞和间质细胞表达最强 ,并定位于腺上皮和腔上皮细胞表面 ,呈顶浆分泌状。结论 :HB-EGF存在于人各期子宫内膜 ,在植入窗期明显高表达可能参与介导胚泡着床 ,并与间质细胞的生长、分化有关 ,利于子宫内膜蜕膜化 ,为胚泡着床做准备。     

Bladder epithelial cells from patients with interstitial cystitis produce an inhibitor of heparin-binding epidermal growth factor-like growth factor production

PURPOSE: The etiology of interstitial cystitis is unknown. We previously identified an interstitial cystitis urine factor, antiproliferative factor, that inhibits proliferation of bladder epithelial cells in vitro and complex changes in epithelial growth factor levels, including profound decreases in heparin-binding epidermal growth factor-like growth factor (HB-EGF). Bladder and renal pelvic catheterization of patients with interstitial cystitis indicated that the antiproliferative factor is made and/or activated in the distal ureter or bladder. Therefore, we determined whether bladder epithelial cells from interstitial cystitis cases produced the antiproliferative factor and whether purified antiproliferative factor could alter production of growth factors known to be abnormal in interstitial cystitis. MATERIALS AND METHODS: Antiproliferative factor activity was determined by 3H-thymidine incorporation into primary bladder epithelial cells. The antiproliferative factor was purified by size fractionation followed by sequential chromatography involving ion exchange, hydrophobic interaction and high performance liquid chromatography. HB-EGF, epidermal growth factor, insulin-like growth factor and insulin-like growth factor binding protein 3 levels were determined by enzyme-linked immunosorbent assay. RESULTS: Bladder epithelial cells from patients with interstitial cystitis produced a single antiproliferative factor with the same purification profile as that purified from interstitial cystitis urine. Purified antiproliferative factor specifically inhibited HB-EGF production by bladder epithelial cells in vitro, and the effect of interstitial cystitis urine or purified antiproliferative factor on bladder cell proliferation was inhibited by recombinant human HB-EGF in a dose dependent manner. Similar to urine HB-EGF, serum HB-EGF was also significantly lower in interstitial cystitis cases than in controls. CONCLUSIONS: Bladder epithelial abnormalities in interstitial cystitis may be caused by a negative autocrine growth factor that inhibits cell proliferation by down-regulating HB-EGF production. Furthermore, decreased levels of urine and serum HB-EGF indicate that interstitial cystitis may be a urinary tract manifestation of a systemic disorder.     

肠缺血／再灌注损伤与防治措施

背景肠缺血／再灌（ischemia／reperfusion,I／R）损伤是外科实践中常见的组织器官损伤之一,在严重感染、创伤、休克、心肺功能不全等疾病的病理生理演变过程中起重要作用。目的就肠I／R损伤产生机制以及防治措施的研究进展进行综述,为今后临床工作提供指导。内容针对肠I／R损伤机制（氧自由基、能量缺乏、细胞内Ca^2＋超载、炎症反应、细胞异常凋亡）及其防御措施的研究进展展开论述。趋向肠I／R损伤是综合性原因引起,采取综合性防治措施可防治肠I／R损伤。     

肠缺血后处理对兔缺血再灌注损伤小肠上皮细胞线粒体形态和功能的影响

目的观察缺血后处理对小肠缺血再灌注损伤的保护作用。方法30只大白兔随机分为3组，每组8只：A组，假手术组；B组，肠缺血再灌注损伤模型组；C组，肠缺血再灌注损伤模型肠缺血后处理组，实验结束后取小肠标本进行小肠上皮细胞形态和呼吸功能指标测定。结果A、C两组线粒体的数目、周长均大于B组，A、C两组问比较，A组较大（P〈0．05）。A、C两组线粒体的面积、最大直径、最小直径、等效直径均小于B组（P〈0．05），A、C两组间比较差异无统计学意义（P〉0．05）。B组线粒体的体积密度小于A组，面积密度、比表面和粒子数密度均小于其余两组（P〈0．05）。A、C两组间三维平面形态计量学各参数比较差异无统计学意义（P〉0．05）；B、C组线粒体呼吸控制比率（RCR）低于A组差异有统计学意义（P〈0．05），与C组比较，B组下降更为明显（P〈0．05）。结论小肠缺血后处理对缺血再灌注损伤肠上皮细胞线粒体形态和功能均有保护作用。     

HB-EGF augments the ability of mesenchymal stem cells to attenuate intestinal injury

Background

We have previously demonstrated that heparin-binding EGF-like growth factor (HB-EGF) and mesenchymal stem cell (MSC) administration protect the intestines from ischemia/reperfusion (I/R) injury in vivo, with amniotic fluid-derived MSC (AF-MSC) being more efficacious than bone marrow-derived MSC (BM-MSC). The goal of the current study was to determine whether the protective effects of HB-EGF were from direct effects on MSC or via alternative mechanisms.

Methods

Murine MSC were transfected with an HB-EGF plasmid or control plasmid by electroporation. Mice were subjected to segmental intestinal I/R injury and received either BM-MSC or AF-MSC either with or without exogenous HB-EGF, or BM-MSC or AF-MSC that endogenously over-expressed HB-EGF. MSC engraftment, intestinal histologic injury, and intestinal permeability were quantified.

Results

There was increased MSC engraftment into injured compared to uninjured intestine. HB-EGF increased AF-MSC engraftment into injured intestine. Administration of HB-EGF and MSC improved intestinal histology and intestinal permeability after I/R injury, with AF-MSC being most efficacious. The effect of HB-EGF on MSC was similar when the growth factor was administered exogenously, or when it was overexpressed endogenously.

Conclusions

The effect of HB-EGF on AF-MSC was similar with both exogenous administration and endogenous overexpression of the growth factor, implying that HB-EGF has a direct effect on AF-MSC. This information may assist in guiding potential future AF-MSC-based therapies for patients at risk of intestinal ischemic injuries.     

缺血预处理在肠缺血/再灌注损伤中的研究进展

缺血预处理是近年来提出的一种新的肠缺血/再灌注损伤的保护方法,即使在小肠长时间缺血/再灌注之前,进行一次或多次短暂的缺血,再灌注过程.研究表明缺血预处理对小肠缺血/再灌注损伤具有保护作用,但机制复杂,尚未明确.现就缺血预处理在肠缺血,再灌注损伤中的研究进展作一综述.     

铁死亡在肝缺血—再灌注损伤大鼠肠损伤中的作用

目的 探究铁死亡在肝缺血-再灌注损伤(HIR)大鼠肠损伤中的作用。方法 选择健康清洁级雄性SD大鼠40只,周龄8～10周,体重220～260 g。采用随机数字表法将大鼠分成四组：假手术组(S组)、铁死亡抑制剂Ferrostatin-1+假手术组(SF组)、HIR模型组(IR组)和铁死亡抑制剂Ferrostatin-1+HIR模型组(IF组),每组10只。S组腹腔注射等容量0.02%DMSO,30 min后行假手术,仅进行开腹、分离第一肝门和关腹处理。SF组腹腔注射Ferrostatin-1(溶于0.02%DMSO)5 mg/kg, 30 min后行假手术。IR组腹腔注射等容量0.02%DMSO,30 min后制备HIR模型。IF组腹腔注射Ferrostatin-1(溶于0.02%DMSO)5 mg/kg, 30 min后制备HIR模型。于再灌注后8 h处死大鼠,取小肠组织,采用ELISA法检测肠组织丙二醛(MDA)、谷胱甘肽(GSH)和铁(Fe²⁺)浓度;采用速率法检测血清中ALT和AST活性;采用Western blot法检测谷胱甘肽过氧化物酶4(GPX4)、铁...     

Androgenic and antiandrogenic control on epidermal growth factor,epidermal growth factor receptor,and androgen receptor expression in human prostate cancer cell line LNCaP

Both androgen and antiandrogen treatments enhance the proliferation rate of the hormone-dependent prostate cancer cell line LNCaP, expressing a mutated androgen receptor (AR). We studied the modification of the expression of epidermal growth factor (EGF), of its receptor (EGF-R), and of androgen receptor (AR) in the LNCaP cell line, under basal conditions and during androgen (R1881) and antiandrogen hydroxy-flutamide (OH-FLU) treatment. After prolonged R1881 administration, a marked increase of EGF release was observed, completely blocked by the addition of OH-FLU. The Scatchard plot analysis of EGF-R binding revealed two classes of binding sites with high and low affinity. The administration of OH-FLU alone or combined with R1881 did not modify the affinity constants, while the low-affinity component disappeared after androgen administration. Both androgen and antiandrogen administration led to a significant increase of the EGF-R high-affinity component. AR mRNA and protein levels were downregulated by R1881 treatment. Following OH-FLU administration, AR mRNA was slightly downregulated, and there was not a strict parallelism between AR mRNA levels and AR binding capacity. When combined with R1881, OH-FLU partially counteracted the androgen-induced AR downregulation. Our data show that EGF-R binding capacity is the only parameter constantly raised in cell proliferation with respect to quiescent cells, and highlights the nonunivocal action of OH-FLU on androgen-induced effects.     

Bladder stretch alters urinary heparin-binding epidermal growth factor and antiproliferative factor in patients with interstitial cystitis

PURPOSE: The etiology of interstitial cystitis is unknown. Urine from patients with interstitial cystitis has been shown to inhibit urothelial proliferation through a putative antiproliferative factor and to contain decreased levels of heparin-binding epidermal growth factor-like growth factor (HB-EGF) compared to controls. Stretch of detrusor smooth muscle cells is known to stimulate HB-EGF production. Because bladder hydrodistention sometimes alleviates the symptoms of interstitial cystitis, we determined whether the stretch stimulus of hydrodistention alters antiproliferative factor activity and/or HB-EGF in interstitial cystitis urine specimens. MATERIALS AND METHODS: Urine was collected immediately before, and 2 to 4 hours and 2 weeks after hydrodistention from 15 patients with symptoms and cystoscopic findings compatible with interstitial cystitis and 13 controls. Hydrodistention was performed with the subject under general or regional anesthesia and bladders were distended to 80 cm. water 3 times. Urinary HB-EGF was measured by enzyme-linked immunosorbent assay and urinary antiproliferative factor activity was determined by measuring 3H-thymidine uptake by normal human bladder urothelial cells. RESULTS: Hydrodistention significantly increased urinary HB-EGF in patients with interstitial cystitis toward normal control values (before distention p = 0.003, 2 weeks after distention p = 0.67). Urine antiproliferative factor activity decreased significantly after hydrodistention in patients with interstitial cystitis. However, antiproliferative factor activity in interstitial cystitis and control specimens was still statistically different 2 weeks after distention (before distention p = 0.0000004, 2 weeks after distention p = 0.04). CONCLUSIONS: Bladder stretch increased HB-EGF and conversely reduced antiproliferative factor activity in urine from patients with interstitial cystitis but not controls up to 2 weeks after distention. These results provide additional evidence for the possible role of antiproliferative factor and decreased HB-EGF in the pathophysiology of interstitial cystitis. To our knowledge this is also the first human study to show that in vivo bladder stretch can alter urinary factors that regulate cell growth.     

七氟醚后处理对大鼠肠缺血再灌注损伤的影响

目的 评价七氟醚后处理对大鼠肠缺血再灌注损伤的影响.方法 成年雄性SD大鼠36只,体重200 ～ 220 g,采用随机数字表法,将其分为4组(n=9)∶假手术组(Sham组)、肠缺血再灌注组(I/R组)、缺血后处理组(Ipo组)和七氟醚后处理组(Sevo组).I/R组、Ipo组Sevo组采用结扎肠系膜上动脉60 min,再灌注120min的方法制备肠缺血再灌注模型.Ipo组于再灌注即刻恢复血流30 s后再阻断30 s,重复3次行后处理.Sevo组于再灌注即刻吸入1.15％七氟醚30 min行后处理.再灌注120 min时,处死大鼠,取小肠组织,采用Chui评分法行病理学损伤评分;采用TUNEL法计算凋亡细胞密度;采用比色法检测MDA含量和SOD活性;采用Western blot法检测caspase-3蛋白表达.结果 与Sham组相比,I/R组、Sevo组和Ipo组病理学损伤评分、凋亡细胞密度和MDA含量均升高,SOD活性降低,caspase-3蛋白表达上调(P＜0.05);与I/R组相比,Sevo组和Ipo组病理学损伤评分、凋亡细胞密度和MDA含量均降低,SOD活性升高,caspase-3蛋白表达下调(P＜0.05);Sevo组和Ipo组病理学损伤评分、凋亡细胞密度、MDA含量、SOD活性和caspase-3蛋白表达比较差异无统计学意义(P＞0.05).结论 七氟醚后处理可通过减轻脂质过氧化反应和减少细胞凋亡,减轻大鼠肠缺血再灌注损伤,其保护效应与缺血后处理相似.     

缺血后处理对兔小肠缺血再灌注损伤的影响

目的评价缺血后处理对兔小肠缺血再灌注损伤的影响。方法30只新西兰大白兔随机分为3组（n=10）,缺血再灌注组（I/R组）夹闭肠系膜上动脉（SMA）1h,再灌注3h,制备肠缺血再灌注模型;缺血预处理组（IPr组）夹闭SMA 5min,再灌注5min,重复3次后夹闭SMA 1h,再灌注3h;缺血后处理组（IPo组）夹闭SMA 1h,再灌注10s,缺血10s,重复3次后再灌注3h。再灌注3h后在回盲末端10cm处取0.5cm小肠段,电镜下观察肠上皮细胞线粒体结构,测定线粒体二维形态计量学参数和三维形态计量学参数;另取60cm相邻小肠段,测定肠上皮细胞线粒体呼吸控制率（RCR）和线粒体内细胞色素C含量。结果与I/R组比较,IPr组和IPo组线粒体的数目、周长、面积密度、粒子数密度及比表面增大,线粒体的面积、最大直径、最小直径及等效直径减小,线粒体RCR及细胞色素C含量升高,IPr组线粒体体积密度增加（P〈0.05）,3组间形状因子比较差异无统计学意义（P〉0.05）。电镜下IPr组和IPo组线粒体结构损伤较I/R组减轻。结论缺血后处理可减轻兔小肠缺血再灌注损伤。     

表皮生长因子在肥大乳房乳腺组织中表达的意义

目的：探讨表皮生长因子（EGF）在肥大乳房乳腺组织中的表达及意义。方法：采用免疫组织化学SP法,检测28例肥大乳房和12例正常体积乳房乳腺组织中表皮生长因子（EGF）的表达状况。结果：肥大乳房组28例患者中有19例表皮生长因子（EGF）呈阳性表达（阳性表达率为67．86％）,正常体积乳房组12例患者中EGF不表达或呈微弱表达。在本实验中EGF的表达与患者是否有哺乳史及肥大乳房的体积大小没有明显的关系。结论：EGF可能在乳房肥大的发生过程中起着重要作用。     

Effect of Shenfu Injection （ ginesenoside and aconite alkaloid） on the apoptosis of intestinal mucosal epithelial cells and its mechanism during ischemia-reperfusion in rats

hegutisnotonlyatargetorganfortraumaandshockbutalsoasatriggerforsystemicinflammationresponsesyndrome .Intestinalmucosalischemiaandreperfusioninjuryisanimportantandessentialetiologicalbasisleadingtomultipleorgandisfunctionsyndrome (MODS) .1Howtopreventandtreatshock ,trauma ,aswellastheischemiaandreperfusioninjuryofthegastrointestinaltracthasbecomethecruxtostudy .Ithasbeenprovedthatcellapoptosisisthemainpatternforthedeathofintestinalepithelialcellsduringischemiaandreperfusion .2 Ithasbeenincrea…     

The effect of gradually increased blood flow on ischemia-reperfusion injury in rat kidney

BACKGROUND: Gradually increased blood flow to the ischemic rat kidney was studied to assess the ability to diminish ischemia-reperfusion injury. METHODS: The left renal artery and vein were isolated in 25 rats. Microclamps were applied for 45 minutes and were released at once (group II) or gradually (group III). Renal arterial blood flow and K+ activity were measured. Bilateral kidneys were harvested for histopathology and for malonyldealdehyde and myeloperoxidase levels. RESULTS: Increased K+ activity returned to preischemic values faster in group III than in group II. No statistically significant difference existed in malonyldealdehyde and myeloperoxidase levels; histopathologic scoring showed less tissue damage in group III (P < .05). Contralateral kidney samples showed signs of ischemia in group II. CONCLUSIONS: Gradually increased blood flow to the ischemic kidney decreases ischemic changes. Ischemic insult to 1 kidney causes histopathologically detectable changes to the contralateral kidney, which can be diminished by gradual reperfusion.     

NF-κB激活在大鼠心肌细胞缺血-再灌注损伤中的意义

目的 从心肌核转录因子κB(nuclear factor kappa B,NF-κB)途径研究心肌缺血-再灌注损伤早期较多细胞因子表达的分子机制. 方法建立大鼠离体工作心脏模型,66只大鼠随机分为实验组和对照组.实验组于缺血5、15分钟和对照组于缺血0、5、15、30分钟、再灌注5、15、30、45和60分钟分别测定NF-κB的脱氧核糖核酸(DNA)结合活性变化、细胞质IκBα水平和肿瘤坏死因子α(TNF-α) mRNA的表达. 结果对照组短时间缺血即引起NF-κB的DNA结合活性增强,同时细胞质IκBα水平明显下降;再灌注后NF-κB的DNA结合活性明显增强,细胞质IκBα水平有所恢复.实验组NF-κB的DNA结合活性明显受抑制,TNF-α mRNA的表达亦受到抑制. 结论心肌缺血-再灌注过程中NF-κB由两种不同的途径激活,激活的心肌NF-κB有p65-p50和p50-p50两种形式,NF-κB的快速活化是心肌缺血-再灌注早期较多细胞因子表达的始动因素.     

静脉输注高氧液对家兔小肠缺血再灌注损伤的影响

目的 评价静脉输注高氧液对家兔小肠缺血再灌注损伤的影响.方法 健康成年家兔24只,雌雄不拘,体重2.5 ～ 3.2 kg,采用随机数字表法,将家兔随机分为3组(n=8):假手术组(S组)、小肠缺血再灌注组(I/R组)和静脉输注高氧液组(HOS组).S组仅开腹游离但不夹闭肠系膜上动脉,I/R组和HOS组采用夹闭肠系膜上动脉1h恢复灌注2h的方法制备家兔小肠缺血再灌注模型,于夹闭肠系膜上动脉即刻HOS组耳缘静脉输注高氧液20 ml·kg-1 ·h-1,I/R组静脉输注等容量生理盐水.于再灌注2h时采集下腔静脉血样,检测血清乳酸浓度,处死家兔取小肠组织,测定丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、谷胱甘肽过氧物酶(GSH-Px)的活性,光镜及电镜下观察肠上皮组织病理学结果,行肠黏膜损伤评分.取内脏组织,观察细菌移位情况.结果 与S组相比,I/R组和HOS组肠组织MDA含量、血清乳酸浓度和细菌移位率升高,SOD、CAT和GSH-Px活性降低(P＜0.05);与I/R组相比,HOS组肠组织MDA含量、血清乳酸浓度和细菌移位率降低,SOD、CAT和GSH-Px活性降低(P＜0.05).结论 静脉输注高氧液可减轻家兔小肠缺血再灌注损伤.