EDU免疫荧光法检测整合素连接激酶（ILK）高表达对新生大鼠心肌细胞DNA合成的影响

目的：通过EDU免疫荧光法观察整合素连接激酶（Integrin-Linked Kinase,mK）在新生大鼠心肌细胞内高表达后对心肌细胞DNA合成的影响。方法：取新生（1-3天内）大鼠原代心肌细胞,培养72小时后随机分为正常对照组、ILK转染组。对照组转染重组腺病毒载体（adeno-GFP）,ILK纽转染重组腺病毒载体＋ILK基因（adeno-ILK）。转然成功后48小时将两组心肌细胞分别通过5-乙基-2-脱氧尿嘧啶核苷（EDU）免疫荧光法测定心肌细胞DNA合成。结果：ILK转染组心肌细胞内DNA合成较对照组明显增加（P〈O．05）。结论：ILK高袁达具有促进新生大鼠心肌细胞的DNA合成的能力。     

EDU 免疫荧光法检测整合素连接激酶（ILK）高表达 对新生大鼠心肌细胞DNA 合成的影响

目的:通过EDU免疫荧光法观察整合素连接激酶(Integrin-Linked Kinase,ILK)在新生大鼠心肌细胞内高表达后对心肌细胞DNA合成的影响。方法:取新生(1-3天内)大鼠原代心肌细胞,培养72小时后随机分为正常对照组、ILK转染组。对照组转染重组腺病毒载体(adeno-GFP),ILK组转染重组腺病毒载体+ILK基因(adeno-ILK)。转然成功后48小时将两组心肌细胞分别通过5-乙基-2’-脱氧尿嘧啶核苷(EDU)免疫荧光法测定心肌细胞DNA合成。结果:ILK转染组心肌细胞内DNA合成较对照组明显增加(P<0.05)。结论:ILK高表达具有促进新生大鼠心肌细胞的DNA合成的能力。     

Evaluating UV-B effects and EDU protection in cucumber leaves using fluorescence images and fluorescence emission spectra

A newly developed laboratory fluorescence imaging system was used to obtain fluorescence images (FImage) of freshly excised cucumber (Cucumis sativus L.) leaves in spectral bands centered in the blue (F450), green (F550), red (F680), and far-red (F730) spectral regions that resulted from a broad-band (300-400 nm) excitation source centered at 360 nm. Means of relative fluorescence intensities (RFI) from these spectral fluorescence images were compared with spectral fluorescence emission data obtained from excitation wavelengths at 280 nm (280EX, 300-550 nm) and 380 nm (380EX, 400-800 nm) of dimethyl sulfoxide (DMSO) extracts from these leaves. All three fluorescence data types (FImage, 280EX, 380EX) were used to assess ultraviolet-B (UV-B, 280-320 nm) induced physiological changes and the possible use of N-[2-(2-oxo-1-imidazolidinyl) ethyl]-N′-phenylurea (EDU or ethylenediurea) as a chemical protectant against UV-B damage. Plants exhibited well known foliar growth and pigment responses to UV-B exposure (e.g., increased UV-B absorbing compounds and decreased leaf area, chlorophyll a content; and and lower chlorophyll a/b and chlorophyll/carotenoid pigment ratios). Since EDU alone had no effect on foliar variables, there was no evidence that EDU afforded protection against UV-B. Instead, EDU augmented some UV-B effects when provided in conjunction with UV-B irradiation (e.g., reductions in the chlorophyll/carotenoid ratio, total photosynthetic pigments, and chlorophyll b content).Relative fluorescence intensities (RFI) in the longer visible wavelengths (green, red, and far-red) were uncorrelated for comparisons between the FImage and 380EX data sets. However, blue and green RFI were significantly correlated (0.8r0.6; P ≤0.002) for comparisons between FImage and 280EX data sets. UV-B treatment caused an increase in blue RFI (e.g., F450) in both images and 280EX measurements. One explanation is that the UV-B excitation of both 280EX and FImage stimulates processes that produce excess blue fluorescence. The molecules that produce the excess blue fluorescence in both the 280EX and the Fimage data are different electron transfer agents that operate in parallel. For FImage, the UV excitation penetrates leaf surface layers to stimulate fluorescence from compounds in mesophyll and epidermal tissues (as occurs for the extracts of leaf discs), whereas emissions captured at longer, less energetic wavelengths, were primarily from the epidermal layer. UV-B irradiated leaves showed much greater heteorgeneity of RFI in both the green (F550_FImag) and the red (F680_FImag) bands than unirradiated leaves; this was true irrespective of EDU treatment.Although qualitative responses in individual bands differed between FImage and 380EX data, similar results were obtained in the detection of UV-B induced effects when the red/green and blue/far-red fluorescence ratios of these data were compared. The red/green ratio (either F680/F550_FImage or F675/F525_380EX) was lower for UV-B exposed plants in both images and 380EX data. UV-B exposure also significantly enhanced the blue/far-red ratio of images (F450/F740_FImage) and the comparable 380EX ratio (F450/F730_380EX) for the combined UV-B/EDU group. The far-red/red ratios were not useful in separating treatment effects in images or 380EX. Although comparable ratios were not available in 280EX data, the UV/blue ratio (F315/F420_280EX) was substantially reduced by UV-B exposure and was inversely related to total photosynthetic pigment content. These findings suggest that the red/green ratio (FImage, 380EX) and the UV/blue ratio (280EX) may be as useful as the blue/far-red ratio (380EX) reported previously in detection of UV-B stress. Furthermore, the results support the validity of the imaging technique as a non-destructive diagnostic tool for assessing UV-B stress damage in plants.     

Studies on the mechanisms of ozone tolerance: Cytokinin-like activity of N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N'-phenylurea, a compound protecting against ozone injury

The cytokinin-like activity of the growth regulating chemical EDU, N-[2-(2-oxo-1-imidazolidinyl)ethyl]-N'-phenylurea, was determined and compared with the actitivity of kinetin using the tobacco callus bioassay. EDU has a pronounced stimulatory effect on callus growth at concentrations of 5 × 10⁻⁴ and 1 × 10⁻³ M but was 5 000 times less potent than the synthetic cytokinin, kinetin. Senescence regulation and oxidant resistance induced by EDU and kinetin were also studied. EDU retarded the breakdown of chlorophyll, protein and RNA in 0₃-sensitive tobacco leaf discs during senescence. EDU was much more effective in arresting senescence and in protecting against 0₃ injury than kinetin. Results indicate the EDU-induced plant tolerance to 0₃ phytotoxicity may be indirect through enzyme induction regulation.