Upregulation of VEGF and FGF2 in normal rat brain after experimental intraoperative radiation therapy

The expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF)2 in the irradiated brain was examined to test how a single high dose radiation, similar to that used for intraoperative radiation therapy given to the normal cerebrum, can affect the vascular endothelium. After a burr hole trephination in the rat skull, the cerebral hemisphere was exposed to a single 10 Gy dose of gamma rays, and the radiation effect was assessed at 1, 2, 4, 6, and 8 weeks after irradiation. Histological changes, such as reactive gliosis, inflammation, vascular proliferation and necrosis, were correlated with the duration after irradiation. Significant VEGF and FGF2 expression in the 2- and 8-week were detected by enzyme-linked immunosorbent assay quantification in the radiation group. Immunohistochemical study for VEGF was done and the number of positive cells gradually increased over time, compared with the sham operation group. In conclusion, the radiation injuries consisted of radiation necrosis associated with the expression of VEGF and FGF2. These findings indicate that VEGF and FGF2 may play a role in the radiation injuries after intraoperative single high-dose irradiation.     

Manganese [correction of Magnesium] superoxide dismutase (MnSOD) plasmid/liposome pulmonary radioprotective gene therapy: modulation of irradiation-induced mRNA for IL-I, TNF-alpha, and TGF-beta correlates with delay of organizing alveolitis/fibrosis.

Radiation pneumonitis remains a critical dose-limiting toxicity of total body irradiation (TBI) for use in bone marrow transplantation. The acute and chronic phases of radiation damage in the mouse lung have been shown to correlate with mouse strain genotype and are dependent on fraction size, total dose, and total lung volume. Our prior studies demonstrated effective prevention of irradiation-induced lung damage and improved survival in C57BL/6J mice by MnSOD plasmid/liposome gene therapy. In the present studies, we investigated the kinetics of irradiation-induced upregulation of mRNA for acute phase cytokines interleukin (IL)-1 and tumor necrosis factor (TNF)-alpha, and fibrosis-associated transforming growth factor (TGF)-beta and isoforms (TGF-beta1, TGF-beta2 and TGF-beta3) in 2000 cGy whole-lung irradiated C57BL/6J mice, a strain known to develop dose and volume-dependent organizing alveolitis/fibrosis. The results demonstrate increase in mRNA for IL-1 between days 1 and 14 after irradiation with return to baseline levels out to 120 days. TNF-alpha mRNA levels were not initially elevated but increased between 80 and 100 days and then decreased by 120 days. The mRNA levels for TGF-beta1 demonstrated an initial increase within the first 14 days after total lung irradiation with a decrease to baseline levels out to 100 days. Then, in striking contrast to the other two cytokines, an increase in TGF-beta2 mRNA occurred at around 120 days and correlated with the detection of organizing alveolitis/radiation fibrosis and mortality. These results are consistent with a two-phase mechanism in the molecular pathology of irradiation lung injury, in which IL-1 cytokine mRNA levels correlated with the acute pneumonitis phase and delayed elevation of TNF-alpha (80-100 days), TGF-beta1 (100 days), and TGF-beta2 (120 days) were associated with the fibrosis phase. Insight into the cell-specific and tissue-specific molecular mechanisms of ionizing irradiation induction of mRNA for pulmonary cytokines may provide new strategies for treatment of radiation pneumonitis in TBI patients.     

Wistar大鼠的咬肌放射损伤模型

背景：构建稳定可靠的咬肌放射损伤模型对颌面部肿瘤放疗的相关研究有重要意义。 目的：以放射剂量40 Gy照射后Wistar大鼠咬肌构建大鼠咬肌放射损伤模型。 方法：成年Wistar大鼠20只,随机分成正常对照组和放射损伤组。放射损伤组采用直线加速器照射大鼠咬肌区累积40 Gy制造咬肌放射损伤。在28 d后,在光镜及电镜下观察咬肌放射区病理改变,RT-PCR检测转化生长因子β1的基因表达。 结果与结论：40 Gy照射后28 d大鼠咬肌区出现结构受损、血管密度减低(P < 0.01)等放射损伤表现,同时引起转化生长因子β1的基因表达升高(P < 0.001)等机体被动修复表现。结果证实Wistar大鼠咬肌区直线加速器40 Gy照射可以作为咬肌放射损伤模型。     

Expression of tumor necrosis factor-alpha and transforming growth factor-beta 1 in acute liver injury

Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta 1) have a number of in vitro functions that could be important in vivo in acute liver injury and repair. Therefore, we investigated these two cytokines in acute liver damage. Northern blots of RNA isolated from rats sacrificed at various time intervals after a single oral dose of CCl4 revealed that TNF-alpha mRNA levels were elevated within 6 hr of CCl4 administration and returned to control values by 24-32 hr. In contrast, TGF-beta 1 mRNA levels started to rise significantly at 24 hr, peaked at 48 hr, and approached baseline levels by 72 hr. Identical changes in TNF-alpha and TGF-beta 1 mRNA levels were also seen with D-galactosamine-induced hepatotoxicity. Immunohistochemical analysis using a TGF-beta 1 antibody demonstrated increased hepatic staining in CCl4-treated rats, at times corresponding to the increases in TGF-beta 1 gene expression. Therefore, there is a differential expression of these cytokines in acute CCl4 and galactosamine hepatotoxicity with an early rise in TNF-alpha, suggesting that this cytokine may affect inflammation and cell toxicity, while TGF-beta 1 peaks later, when it may regulate hepatocyte proliferation and extracellular matrix repair.     

放射性心脏损伤模型大鼠接受吡格列酮干预的心脏保护作用

背景：激活过氧化物酶体增殖物活化受体γ信号途径在心血管系统有许多正效应。血管紧张素Ⅱ与心肌的纤维化密切相关,然而却很少有研究关注激活过氧化物酶体增殖物活化受体γ途径能否通过减弱血管紧张素Ⅱ的表达从而改善放射性心肌损伤。 目的：探索激活过氧化物酶体增殖物活化受体γ后血管紧张素Ⅱ 1型受体对放射性心脏损伤模型大鼠的作用。 方法：60只大鼠随机等分为对照组、吡格列酮组、模型组及照射+低、高剂量吡格列酮组。模型组及照射+低、高剂量吡格列酮组大鼠采用前后对穿照射方法接受6 MV高能X射线照射野心前1.5 cm×1.5 cm,照射剂量300 cGy/min。照射完后6 h时,低、高剂量吡格列酮组大鼠分别接受10,20 mg/kg吡格列酮灌胃,此后每天灌胃1次,连续灌胃30 d;模型组大鼠灌胃2 mL蒸馏水。吡格列酮组大鼠在对应时间灌胃10 mg/kg吡格列酮。 结果与结论：给予吡格列酮干预后,受照射大鼠的心脏组织损伤减轻,心脏纤维化减轻,心脏组织中血管紧张素Ⅱ 1型受体蛋白及mRNA表达水平减少。提示吡格列酮干预可降低血管紧张素Ⅱ1型受体在大鼠放射性心脏损伤中的表达,提示激活过氧化物酶体增殖物活化受体γ途径可能对放射性心脏损伤有保护作用。 中国组织工程研究杂志出版内容重点：肾移植;肝移植;移植;心脏移植;组织移植;皮肤移植;皮瓣移植;血管移植;器官移植;组织工程全文链接：     

Mice lacking Smad3 are protected against cutaneous injury induced by ionizing radiation

Transforming growth factor-beta (TGF-beta) plays a central role in the pathogenesis of inflammatory and fibrotic diseases, including radiation-induced fibrosis. We previously reported that mice null for Smad3, a key downstream mediator of TGF-beta, show accelerated healing of cutaneous incisional wounds with reduced inflammation and accumulation of matrix. To determine if loss of Smad3 decreases radiation-induced injury, skin of Smad3+/+ [wild-type (WT)] and -/- [knockout (KO)] mice was exposed to a single dose of 30 to 50 Gy of gamma-irradiation. Six weeks later, skin from KO mice showed significantly less epidermal acanthosis and dermal influx of mast cells, macrophages, and neutrophils than skin from WT littermates. Skin from irradiated KO mice exhibited less immunoreactive TGF-beta and fewer myofibroblasts, suggesting that these mice will have a significantly reduced fibrotic response. Although irradiation induced no change in the immunohistochemical expression of the TGF-beta type I receptor, the epidermal expression of the type II receptor was lost after irradiation whereas its dermal expression remained high. Primary keratinocytes and dermal fibroblasts prepared from WT and KO mice showed similar survival when irradiated, as did mice exposed to whole-body irradiation. These results suggest that inhibition of Smad3 might decrease tissue damage and reduce fibrosis after exposure to ionizing irradiation.     

Regeneration of hyaline articular cartilage with irradiated transforming growth factor beta1-producing fibroblasts

The regeneration of hyaline articular cartilage by cell-mediated gene therapy using transforming growth factor beta(1) (TGF-beta(1))-producing fibroblasts (NIH 3T3-TGF-beta(1)) has been reported previously. In this study, we investigated whether TGF-beta(1)-producing fibroblasts irradiated with a lethal dose of radiation are still capable of inducing the regeneration of hyaline articular cartilage. NIH 3T3TGF-beta(1) fibroblasts were exposed to doses of 20, 40, or 80 Gy, using a irradiator, and then injected into artificially made partial defects on the femoral condyle of rabbit knee joints. The rabbits were killed 3 or 6 weeks postinjection and hyaline articular cartilage regeneration was evaluated by histological and immunohistochemical staining (n = 5 per each group). Irradiated NIH 3T3-TGFbeta(1) fibroblasts started to die rapidly 3 days after irradiation; moreover, the kinetics of their viability were similar regardless of the radiation intensity. TGF-beta1 expression, measured by ELISA, showed that the TGF-beta(1) protein produced from the irradiated cells peaked 5 days after irradiation and thereafter declined rapidly. Complete filling of the defect with reparative tissue occurred in all the groups, although variations were observed in terms of the nature of the repair tissue. Histological and immunohistochemical staining of the repair tissue showed that the tissue newly formed by irradiated NIH 3T3-TGF-beta(1) fibroblasts after exposure to 20 Gy had hyaline cartilage-like characteristics, as was observed in the nonirradiated controls. On the other hand, the repair tissue formed by NIH 3T3-TGF-beta(1) fibroblasts irradiated with 40 or 80 Gy showed more fibrous cartilage-like tissue. These results suggest that TGF-beta(1)-producing fibroblasts irradiated up to a certain level of lethal dose (i.e., 20 Gy) are able to induce normal-appearing articular cartilage in vivo. Therefore, irradiated heterologous cell-mediated TGF-beta(1) gene therapy may be clinically useful and an efficient method of regenerating hyaline articular cartilage.     

Low-dose radiation modifies the progression of chronic renal failure

Previous studies have indicated that the application of low dose radiation to an arterial ligation has the potential to subsequently reduce or eliminate restenosis caused by smooth muscle cell proliferation. Sufficient kidney irradiation causes a radiation nephropathy and often leads to renal failure. In order to evaluate the effect of low-dose irradiation on the kidney we hypothesized that this particular therapy modifies renal injury in rats with renal ablation and subsequently slows the rate of the progression. For further clarification of the effect of irradiation at low doses, we determined proliferating cell nuclear antigen (PCNA) and monocyte chemoattractant protein-1 (MCP-1) expression in remnant kidneys after low-dose radiation. Adult Wistar rats (n = 10) were studied during the two weeks after renal ablation. The left kidney was irradiated 24 hours after an operation in anaesthetised animals with 3 Grey in a single dose. Ablated rats without irradiation (n = 9) served as nephrectomized animals group. Rats without surgery and without radiation (n = 10) served as healthy controls. Renal damage was assessed using the following parameters: urine protein excretion rate (UprotV, mg/day), awake systolic blood pressure (SBP, mm Hg), serum creatinine (SCr, micromol/l). The indirect immunofluorescence method was used for the detection of PCNA and MCP-1 expression. Glomerular and tubular immunostaining was scored semiquantitatively. Numerous PCNA positive cells and MCP-1 expression were present in the glomerulus and tubulointerstitium in nephrectomized rat kidneys. Low-dose radiation application was associated with a significant reduction in PCNA and low MCP-1 expression. This study shows that the application of low-dose irradiation has the potential to modify the progression of chronic renal failure in rats.     

少突胶质前体细胞延长神经胶质母细胞瘤大鼠高剂量放疗后的生存期

背景：胶质母细胞瘤是成人常见的恶性脑肿瘤,目前尚缺乏有效的治疗方法,临床预后不良。目的：观察单次高剂量放疗对神经胶质母细胞瘤的疗效,以及少突胶质前体细胞修复放射性脑损伤的可行性。方法：通过质粒转染构建可表达荧光素酶(Luc)的人源性U-87 MG肿瘤细胞系。15只Fisher 344大鼠制备Luc-U-87 MG神经胶质母细胞瘤模型,随机分为肿瘤模型组(n=3)、放疗组(n=6)和放疗+细胞移植组(n=6),后两组放疗方式为单次80 Gy辐射;放疗后5周,放疗+细胞移植组大鼠联合少突胶质前体细胞移植治疗。利用活体成像的方法监测肿瘤细胞的生长;MRI观察放疗引起的脑组织影像学变化;采用KaplanMeier生存分析明确细胞移植对放疗大鼠生存率的影响;对移植细胞的存活及分化情况进行组织学观察。结果与结论：(1)体外生物成像示转染后的U-87 MG细胞与Luc底物产生反应发出生物信号,信号强度与转染细胞的数量呈线性正相关;(2)动物活体成像结果显示,肿瘤模型大鼠的颅内胶质母细胞瘤信号持续上升直至接种第5周(全部死亡);放疗大鼠在治疗后2周,肿瘤信号开始衰减,4周后未见肿瘤发光信号;(3)放疗...     

五味子醇甲通过调控自噬流减轻大鼠脑缺血再灌注损伤

目的:探究五味子醇甲(Sch A)减轻大鼠脑缺血再灌注损伤的作用及其潜在机制.方法:成年雄性SD大鼠随机分为假手术组(sham组)、模型组[大脑中动脉闭塞(MCAO)组]及Sch A低、中、高剂量治疗组,每组6只.制备大鼠左侧MCAO模型,90 min后再灌注,治疗组Sch A的剂量分别为40、80和160μg·kg?...     

Role of type II pneumocytes in pathogenesis of radiation pneumonitis: dose response of radiation-induced lung changes in the transient high vascular permeability period.

We studied the dose response of pulmonary changes at 3 weeks after 1-25 Gy irradiation and we investigated the effects of an anti-inflammatory drug. Wistar rats were given a single dose of 1-25Gy irradiation to the thorax. Group one was treated with saline only, while group two was administered subcutaneously a combination of pentoxifylline (35 mg/kg) and dexamethasone (1 mg/kg) twice per week. Lungs were examined histochemically and number of neutrophile granulocytes, alveolar septal thickness, air/tissue ratio, number of alveoli per field, number of type II pneumocytes per alveolus, and occludin 1 expression were measured. A significant dose-dependent depletion of type II pneumocytes was found after irradiation with a dose of 1 Gy and higher. Alveolar neutrophils increased after 1 Gy with a dose dependency noted after 10-25Gy and alveolar septa thickening followed 5-25 Gy. A lower occludin 1 expression was observed in animals irradiated with the doses of 5 20 Gy, indicating an effect on vascular permeability. Anti-inflammatory therapy partially inhibited the increase of neutrophils at all radiation doses and the depletion of type II pneumocytes after doses of 1, 10, and 15 Gy. Occludin 1 did not decrease in the lungs of rats treated with the anti-inflammatory drugs as it did in most rats treated only with saline. Our results suggest that pneumocytes depletion is a major factor responsible for radiation pneumonitis development and that these changes may be compensated for provided radiation doses are below the threshold.     

Enhancement of nestin protein-immunoreactivity induced by ionizing radiation in the forebrain ependymal regions of rats

Expression of nestin was immunohistochemically examined in the forebrains of rats receiving ionizing radiation. Nestin-immunoreactive cells were predominately distributed in ependymal regions. Nestin-immunoreactivity in ependymal regions of irradiated rats increased significantly from 1 to 4 weeks after ionizing radiation compared with that of controls. Double immunofluorescence confirmed that about 94% of nestin-positive cells exhibited glial fibrillary acidic protein-immunoreactivity and a minor population of them showed Ki-67-immunoreactivity in these regions. The results have provided evidence for up-regulation of nestin expression induced by ionizing radiation in ependymal cells, suggesting that these reactive ependymal cells may be involved in remodeling and repairing processes of brain irradiation injury.     

普罗布考通过TGF-β1/Smad 2/3通路减轻大鼠脑缺血再灌注损伤

目的:探讨普罗布考对大鼠脑缺血再灌注(I/R)的影响及其可能机制。方法:线栓法建立大鼠大脑中动脉栓塞(MCAO)模型,用1.5、3 mg/kg普罗布考进行干预,将200只大鼠分为假手术组、I/R组、溶剂组、小剂量组(1.5 mg/kg)及大剂量组(3mg/kg)。术后15 min腹腔注射药物,于1、3、5 d和7 d取材。观察普罗布考对脑缺血再灌注炎性损伤急性期及恢复早期神经功能评分、梗死灶体积、脑组织水含量的影响,并用ELISA检测脑组织匀浆环氧酶(COX-2)和5脂氧酶(5-LOX)活性变化,免疫印迹检测各组TGF-β1和p-Smad2/3蛋白表达量的变化。结果:与假手术组比较,MCAO术后小鼠出现严重的神经功能障碍、脑水肿和脑梗死,COX-2和5-LOX蛋白表达显著升高,而TGF-β1和p-Smad2/3蛋白表达明显降低;与手术组比较,经普罗布考干预后,小鼠神经功能评分、脑水肿和脑梗死情况明显改善,COX-2和5-LOX蛋白表达明显降低,而TGF-β1和p-Smad2/3蛋白表达明显升高,且大剂量组优于小剂量组。结论:普罗布考能缓解大鼠脑缺血再灌注炎性损伤,其机制可能与激活TGF-β1/Smad2/3信号通路,抑制脑内COX-2与5-LOX的活性有关。     

中等剂量(20Gy)辐照对大鼠脑内c-fos表达的早期影响

目的　探讨电离辐射对大鼠脑内Fos蛋白表达的早期影响。　方法　应用大鼠半脑 2 0Gy照射模型 ,免疫组织化学方法 ,观察Fos蛋白在脑内的表达及分布情况。　结果　受照射后 2 4h、1周大鼠脑内各部位Fos蛋白表达均明显减少 ,随着时间的延长 ,其Fos免疫反应性细胞数量逐渐增加 ,照射后 4周 ,延髓、脑桥内Fos免疫阳性细胞数量恢复并超过正常对照组水平 ,但中脑、间脑及端脑内未恢复到正常对照组水平。　结论　结果提示 :中等剂量辐射后早期 ,脑内许多核团的神经细胞功能活动可能受到抑制 ,并且越高级的中枢受到的抑制影响越明显     

Role of heat shock protein 47 on tubulointerstitium in experimental radiation nephropathy

The molecular mechanisms of fibrosis in radiation nephropathy have received scant attention. Heat shock protein 47 (HSP47), a collagen-binding stress protein, helps in the intracellular processing of procollagen molecules during collagen synthesis. We investigated the role of HSP47 in the progression of radiation nephropathy using experimental radiation nephropathy. Experimental rat groups were as follows: (i) group I, sham operated (n = 12); (ii) group II, single doses of irradiation, either 7, 15 or 25 Gy to left kidney (n = 60); and (iii) group III, a similar irradiation procedure as group II after right nephrectomy (n = 60). The rats were followed up until 9 months after renal exposure to radiation. Renal dysfunction (as determined by serum creatinine and blood urea nitrogen) and hypertension were noted in group III rats, along with inflammatory cell infiltration and interstitial fibrosis (as determined by increased deposition of collagens). Compared to control rat kidneys, an increased expression of HSP47 was noted in kidneys obtained from irradiated rats. By double immunostaining, HSP47-expressing cells were identified as alpha-smooth muscle actin-positive myofibroblasts and vimentin-positive tubular epithelial cells. Increased expression of HSP47 was closely associated with increased deposition of collagens in the widened interstitium of irradiated rats. Overexpression of HSP47 by phenotypically altered tubulointerstitial cells might play a role in excessive assembly/synthesis of collagens and could contribute to tubulointerstitial fibrosis in radiation nephropathy.     

^60Coγ射线照射对肺泡Ⅱ型细胞和肺泡隔间质细胞的生物效应

目的：探讨^60Coγ射线照射对肺泡Ⅱ型细胞和肺泡隔间质细胞的生物效应。方法：原代分离肺内Ⅱ型上皮细胞（AT-Ⅱ）和间质细胞包括巨噬细胞和成纤维细胞，分别进行0、3、5、7Gy的γ射线照射，用细胞核嗜银染色观察照射对AT-Ⅱ增殖的影响；用酶谱分析检测照射后AT-Ⅱ和间质细胞培养上清中基质金属蛋白酶-2、-9（MMP-2，-9）的活性；用ELISA检测间质细胞培养上清中TGF-β1和Ⅳ型胶原含量。结果：AT-Ⅱ的核仁数量随照射剂量增加而增多，其中7Gy组最高；AT-Ⅱ培养上清中MMP-2、-9活性随照射剂量增加呈先增高后降低趋势，间质细胞上清中MMP-2、-9活性和TGF-β1水平逐渐升高，Ⅳ型胶原分泌水平呈先降低后升高趋势。结论：放射性肺损伤早期，AT-Ⅱ、巨噬细胞和成纤维细胞均参与肺组织无效性重建过程，与晚期肺纤维化启动有一定的内在联系。     

Neuron-specific enolase reduction in irradiated salivary glands of the rat--an immunohistochemical study.

Neuron-specific enolase (NSE) in the salivary glands of normal and irradiated rats was studied by immunohistochemical methods. The normal salivary gland of Sprague-Dawley rats (465 g) showed positive staining for NSE in striated ducts and granular convoluted tubule (GCT) cells. A single radiation, TDF (time, dose, fractionation factor) 100 and 200 (18.82 Gy and 27.97 Gy, respectively) was done, and 4 groups (1, 2, 3 and 4 weeks after radiation) of 5 rats each were used. Irradiated salivary glands indicated a remarkable reduction of NSE staining in GCT cells and a reduction but to a lesser degree in the striated duct of the submandibular gland. Immunohistochemical deposition of NSE was not changed in the sublingual glands of irradiated rats. The reduction of NSE immunodeposition was irradiation dose dependent.     

Characterization and quantification of cerebral edema induced by synchrotron x-ray microbeam radiation therapy

Cerebral edema is one of the main acute complications arising after irradiation of brain tumors. Microbeam radiation therapy (MRT), an innovative experimental radiotherapy technique using spatially fractionated synchrotron x-rays, has been shown to spare radiosensitive tissues such as mammal brains. The aim of this study was to determine if cerebral edema occurs after MRT using diffusion-weighted MRI and microgravimetry. Prone Swiss nude mice's heads were positioned horizontally in the synchrotron x-ray beam and the upper part of the left hemisphere was irradiated in the antero-posterior direction by an array of 18 planar microbeams (25 mm wide, on-center spacing 211 mm, height 4 mm, entrance dose 312 Gy or 1000 Gy). An apparent diffusion coefficient (ADC) was measured at 7 T 1, 7, 14, 21 and 28 days after irradiation. Eventually, the cerebral water content (CWC) was determined by microgravimetry. The ADC and CWC in the irradiated (312 Gy or 1000 Gy) and in the contralateral non-irradiated hemispheres were not significantly different at all measurement times, with two exceptions: (1) a 9% ADC decrease (p < 0.05) was observed in the irradiated cortex 1 day after exposure to 312 Gy, (2) a 0.7% increase (p < 0.05) in the CWC was measured in the irradiated hemispheres 1 day after exposure to 1000 Gy. The results demonstrate the presence of a minor and transient cellular edema (ADC decrease) at 1 day after a 312 Gy exposure, without a significant CWC increase. One day after a 1000 Gy exposure, the CWC increased, while the ADC remained unchanged and may reflect the simultaneous presence of cellular and vasogenic edema. Both types of edema disappear within a week after microbeam exposure which may confirm the normal tissue sparing effect of MRT.