小肠缺血再灌注损伤导致Cajal间质细胞凋亡的实验研究

目的探讨小肠缺血再灌注损伤对Cajal间质细胞（interstitial cells of Cajal,ICC）的影响。方法采用缺血60 min再灌注6 h（I60/R6h）、12 h（I60/R12h）和14 d（I60/R14d）的豚鼠小肠,通过免疫细胞化学和TUNEL法检测ICC的凋亡。结果I60/R6h豚鼠小肠可见少量TUNEL阳性ICC。I60/R12h可见较多的凋亡ICC,同时ICC细胞数量明显减少,细胞网络不完整。I60/R14d的ICC恢复正常数量和分布。不同时间点之间Kit/TUNEL双标阳性细胞数量存在显著差别（P〈0.05）。结论小肠缺血再灌注损伤导致ICC凋亡,一段时间后ICC能够恢复正常。     

小鼠垂体巢蛋白阳性细胞在体外具有集落生长能力

目的 研究小鼠垂体前叶中巢蛋白(Nestin)阳性细胞在体外培养环境中的自我增殖能力. 方法建立小鼠垂体Nestin阳性细胞克隆生长培养条件,观察次代细胞在其中的生长情况.应用野生型细胞和增强型绿色荧光蛋白(EGFP)细胞混合培养,以及BrdU渗核实验鉴定次代Nestin阳性细胞培养过程中新生细胞群的来源.结果次代Nestin阳性细胞在克隆生长培养基中能够自我增殖.野生型细胞和EGFP细胞混合培养实验表明,新生细胞群由纯野生型细胞或纯EGFP细胞构成.BrdU渗核实验显示,24h内新生细胞群中有13%的细胞由分裂产生(n=20). 结论 部分小鼠垂体前叶Nestin阳性细胞在体外培养环境中具有克隆生长能力.     

小鼠角膜的发生与细胞凋亡

目的 通过观察小鼠角膜的发生过程,探讨角膜细胞的增殖与凋亡对角膜结构修复与塑形的作用。方法 各日龄共计120只小鼠,用HE染色或4’,6-二脒基-2-苯基吲哚（DAPI）染色对小鼠角膜的一般结构进行观察;用5′-溴脱氧尿嘧啶核苷（BrdU）技术标记角膜增殖细胞和免疫荧光法标记干细胞和凋亡细胞。结果 胚胎发育及出生后早期,角膜以实质层的发育为主。出生14d（P14）左右,角膜上皮细胞层开始增殖分化为两层细胞,同时内皮细胞也开始分化。至P30时,我们可以辨别出角膜的6层结构。BrdU阳性细胞主要存在实质层中的成纤维细胞,出生以后也可见于角膜上皮细胞层和内皮细胞层。随着角膜发育,P10左右,其他层的BrdU阳性细胞都消失,仅存在于角膜上皮细胞层。增殖细胞核抗原（PCNA）阳性细胞在发育早期散在分布于角膜的各层,P14以后PCNA阳性细胞均匀的分布于角膜上皮细胞的基底层,并维持在稳定状态。在角膜发育早期,在各层可见许多细胞凋亡。结论 角膜的发育与其感光功能形成的过程相一致,角膜干细胞的增殖与其修复有关;有大量的凋亡细胞参与角膜结构的塑形。     

局灶性脑缺血大鼠皮质和尾壳核神经干细胞增殖分化与nNOS的表达

本研究旨在探讨局灶性脑缺血再灌注大鼠皮质和尾壳核神经干细胞的增殖分化与nNOS表达的关系。大脑中动脉线栓法制作大鼠局灶性脑缺血再灌注模型,5溴脱氧尿核苷(BrdU)标记分裂增殖细胞,免疫组化单标和双标记技术检测各组大鼠缺血侧皮质和尾壳核BrdU阳性细胞和nNOS的表达。模型组大鼠皮质和尾壳核BrdU阳性细胞再灌注后3d开始增多,14d达高峰,nNOS阳性细胞再灌注后7d表达增强,28d达高峰,BrdU/nNOS双标细胞在14d达高峰,占皮质BrdU阳性细胞数的42.95%,尾壳核内占42.56%。新生细胞分化组BrdU阳性细胞和BrdU/nNOS双标细胞显著多于模型组(P<0.05),皮质双标细胞占BrdU阳性细胞数的54.08%,尾壳核内占47.84%。提示局灶性脑缺血可增强大鼠皮质和尾壳核的增殖能力,部分增殖细胞分化为nNOS阳性神经元,参与神经网络的重建。     

表皮生长因子对小鼠肾小管发育中细胞增殖的影响

目的:观察小鼠肾小管发育中细胞增殖和表皮生长因子(EGF)的表达特征,探讨 EGF 对小鼠肾小管发育中细胞增殖的影响.方法:应用 5-溴-2-脱氧尿嘧啶(BrdU)标记增殖细胞.应用免疫组织化学、免疫荧光、免疫印迹技术并结合体视学方法检测生后 1、3、5、6、7、14、21、28、40 d 小鼠肾小管 BrdU 阳性细胞和 EGF 的表达.结果:EGF 于生后6 d表达在肾小管上皮细胞,之后随着日龄的增加表达渐增;BrdU 阳性细胞于生后1 d表达,14 d达高峰,之后随着日龄增加而逐渐减少;生后14 d之后 EGF 与细胞增殖表达趋势完全相反.结论:推测 EGF 在生后小鼠肾发育中对肾小管的分化和成熟起重要作用,但并不促进细胞增殖.     

小鼠脊髓发育与神经细胞凋亡

目的通过观察小鼠脊髓发育过程中神经元的增殖、分化与凋亡,探讨小鼠脊髓的发育过程及其调控机制。方法取妊娠第18天(E18)至生后第90天(P90)小鼠173只,用5’-溴脱氧尿嘧啶核苷(BrdU)技术标记增殖的神经干细胞,免疫荧光法(DCX,NeuN和Caspase8)标记脊髓中的新生神经元,成熟神经元和凋亡细胞。结果在胚胎与出生早期,BrdU阳性细胞均匀分布于小鼠脊髓各部位。随着小鼠日龄的增加,脊髓神经干细胞可以分化为神经胶质细胞与神经元。其后,位于神经管侧脑室的新生神经元向中间层(未来的灰质)迁移,逐渐分化为成熟神经元。最后,神经元向脊髓中央聚集,灰质呈现典型的"H"型。随着神经元的分化,一些凋亡神经细胞出现在新生神经元与成熟神经元中。荧光双标显示,大部分的凋亡神经细胞都是新生神经元,说明神经元凋亡常常发生在新生神经元中。统计学分析表明,DCX、NeuN、Caspase-8标记的阳性细胞数均随小鼠日龄的增加而减少,说明神经元的分化和凋亡在脊髓的发育过程中逐渐减少。结论在脊髓的发育过程中存在着神经元的增殖、分化与凋亡。三者相互协同,共同调节脊髓的形成与发育。     

成年肌萎缩脊髓侧索硬化症转基因鼠脊髓细胞增殖的研究

目的观察成年肌萎缩脊髓侧索硬化症(ALS)转基因模型鼠脊髓内源性细胞的增殖和存活情况。方法对ALS转基因鼠进行BrdU注射,分别于不同时间点取材,冷冻切片,应用免疫荧光染色技术检测脊髓内细胞的增殖、分布和存活情况。结果成年ALS鼠脊髓的中央管、灰质、白质均可检测到BrdU阳性细胞,经常可检测到形状相似、成对出现的细胞。在灰质内,BrdU阳性细胞主要分布于脊髓前角。在白质内,BrdU阳性细胞散在分布。前角ALS鼠脊髓内BrdU阳性细胞数量较野生型鼠多。BrdU末次注射后1d、14d均可检测到BrdU阳性细胞,但细胞数量逐渐减少,28d ALS鼠脊髓内仍可检测到少量BrdU阳性细胞,主要分布于中央管部位。增殖细胞核抗原(PCNA)阳性细胞的分布和变化规律与BrdU阳性细胞一致。在95d龄ALS鼠(BrdU末次注射1d后),脊髓中Nestin阳性细胞较野生型鼠多,多数Nestin阳性细胞分布于脊髓前角,某些细胞呈BrdU/Nestin双标阳性。在BrdU注射后14d、28d脊髓中,未检测到BrdU/Nestin双标阳性细胞。结论神经退行性病变可激活ALS转基因鼠脊髓的细胞增殖,且细胞存活可达28d。     

高原环境对小鼠成体神经发生的影响

目的:探索和研究我国青藏高原高海拔生存环境对于小鼠海马齿状回成体神经干细胞增殖和新生细胞分化的影响。方法:健康成年昆明小鼠分为两组,一组为1519 m海拔高度的兰州对照组,另一组为4547 m海拔高度的青藏高原沱沱河高原环境组。运用BrdU腹腔注射和免疫荧光组织化学相结合的方法研究和比较不同环境中齿状回内成体神经干细胞的增殖和新生细胞的分化。结果:高原环境组的BrdU免疫阳性细胞数与低海拔对照组相比减少了40%(P=0.001),而高原环境组小鼠齿状回中的BrdU/Prox-1标记的双阳性细胞在BrdU标记的阳性细胞中的百分比与对照组相比没有显著的差异(P=0.211),并且两组小鼠齿状回中90%以上的BrdU阳性细胞同时也被Prox-1标记。结论:在青藏高原的高海拔低氧环境中,小鼠海马内成体神经干细胞的增殖明显受抑制,然而新生的细胞向颗粒细胞的分化并没有受到明显的影响。     

局灶性脑缺血后侧脑室室下区神经发生及其与血管内皮生长因子关系的研究

为了研究成年大鼠局灶性脑缺血后侧脑室室下区(SVZ)神经发生的情况及其与血管内皮生长因子(VEGF)的关系,探讨脑缺血后神经发生及其调控机制,本研究通过大脑中动脉阻断法(MCAO)建立大鼠局灶性脑缺血模型,5-溴-2-脱氧尿核苷(BrdU)标记增殖的神经前体细胞,用免疫荧光双标记法动态检测BrdU、TuJ1、MAP-2、GFAP的表达,同时观察增殖细胞表达VEGF及其受体情况。结果显示:与对照组相比,大鼠SVZ的BrdU阳性细胞数在脑缺血后4 d组明显增加,14 d组达到高峰;Br-dU/TuJ1、BrdU/MAP-2阳性双标细胞数在脑缺血后14 d组开始增加,28 d组达到高峰;但BrdU/GFAP阳性双标细胞数则无明显变化;增殖的BrdU阳性细胞同时表达VEGF及其受体FLK-1。以上结果提示:大鼠局灶性脑缺血可激活SVZ自体神经前体细胞原位增殖、分化,且增殖的细胞同时表达VEGF及其受体可能是脑缺血后神经发生增强的调节机制之一。     

小鼠脊髓血管-神经干细胞龛与神经细胞的增殖和分化

目的探讨小鼠脊髓发育过程中血管-干细胞龛对神经干细胞分化、增殖和迁移的影响;探讨龛中的各种细胞、血管在发育中的变化及相互作用。方法发育过程中的胚胎鼠或生后小鼠150只,取脊髓腰膨大处的横断面切片。采用5-溴脱氧尿嘧啶核苷(BrdU)免疫荧光标记神经干细胞;用尼氏(Nissl)染色观察神经元的发育和形态变化;利用血管墨汁灌注结合免疫荧光三重标记的方法检测神经干细胞、神经元和神经胶质细胞在小鼠胚胎期及生后的形态分布变化;同时对脊髓内血管发育的动态变化进行形态学观察和体视学处理。结果妊娠14d(E14)小鼠脊髓内即有BrdU标记的阳性细胞,均匀分布。新生的神经元自神经管侧脑室下带迁移至中间层附近,逐渐分化为神经元,并集中于灰质呈现典型的"H"型。统计学分析表明,BrdU阳性细胞计数在发育中呈现抛物线,高峰值位于出生3d(P3)左右。此外,神经胶质细胞的祖细胞最早集中于边缘白质,随后又向中央的灰质回迁。血管发育经历了早期均匀分布,成年后集中在灰质分布的过程。血管、神经干细胞、神经元和神经胶质细胞构成了所谓的血管-干细胞龛。血管-干细胞龛主要位于侧脑室下带和灰质附近,其中的血管、神经干细胞、神经元和神经胶质细胞互相交织、紧密联系。结论血管-神经干细胞龛与脊髓发育紧密联系,同时影响神经元、神经胶质细胞和血管的相互作用。血管-神经干细胞龛为脊髓发育及神经元和神经胶质细胞分化提供了适宜的微环境。     

Late embryonic and postnatal development of interstitial cells of cajal in mouse esophagus: distribution, proliferation and kit dependence

This paper investigates alterations in interstitial cells of Cajal (ICC) in the esophagus of mice from embryonic day 13.5 (E13.5) to 36 days postpartum (P0-P36) using immunohistochemistry. At E13.5, Kit+ cells presented in clusters and differentiated into spindle-like cells with biopolar processes within the outer (longitudinal) and inner (circular) muscle layers at E17.5. These Kit+ ICC with long processes were also Ano1+ and prominent at birth. The density of ICC gradually decreased, and at P36 it became about one twentieth of that at birth. Kit ligand (stem cell factor) expression is lower in striated muscle cells than that in smooth muscle cells. The ICC number was higher in the distal (close to the cardia) than in the proximal esophagus (close to the pharynx). Some Kit+/Ki67+ and Kit+/bromodeoxyuridine+ cells were observed within the muscle layers, and proliferation persisted from birth through adulthood (P28) with a gradually decreasing cell number. At 24 h, Kit+ ICC were dramatically decreased and almost missing 48 h after administration of imatinib (a Kit inhibitor). Our results indicate that ICC proliferation is age dependent and persists throughout the postnatal period. There is a dramatic decrease in the ICC number from P0 to adult life. The Kit signal is essential for the postnatal development of ICC in the esophagus.     

脑缺血再灌注后小鼠海马神经前体细胞的增殖

目的:研究小鼠脑缺血再灌注后海马神经前体细胞的增殖。方法:采用无创微动脉夹夹闭小鼠双侧颈总动脉0·5h的方法制作脑缺血再灌注动物模型。分正常对照组、假手术组、实验组小鼠脑缺血再灌注后1、3、5、7、14、21、28d组,共7个时相点。各组小鼠于各时相点处死前注射5-溴脱氧尿苷嘧啶(BrdU)。处死后取出脑组织制备石蜡切片进行Nissl染色,BrdU免疫组织化学显色,观察脑组织缺血后的病理变化并比较缺血后不同时相点神经前体细胞增殖的差异。同时从小鼠心采血进行血气分析。结果:夹闭小鼠双侧颈总动脉的脑缺血再灌注模型可致PO2明显降低,PCO2明显升高,大脑皮质出现了缺血的形态学变化。小鼠海马BrdU 细胞在脑缺血再灌注后1d开始增加,7d达到高峰,28d恢复正常水平。结论:夹闭双侧颈总动脉是致小鼠脑缺血再灌注损伤的理想模型。小鼠脑缺血再灌注损伤能激活海马神经前体细胞的增殖,并在术后7d达峰值。     

Postnatal development of interstitial cells of Cajal in mouse colon in response to Kit signal blockade with Imatinib (Glivec)

This study investigated the response of interstitial cells of Cajal (ICC) in postnatal mouse colon to treatment with Imatinib (Glivec®, a potent inhibitor of Kit receptor). ICC were revealed by immunofluorescent staining on frozen cross-sections and whole-mount preparations by anti-Kit and DOG1 antibodies. Kit and p-Kit protein were also evaluated by Western blot. After administration of Imatinib for 4 days beginning at 8 days post-partum (P8), the mean density of Kit⁺ ICC, which were localized around the myenteric nerve plexus (ICC-MY), within smooth muscle layers (ICC-IM) and in the connective tissue beneath the serosa (ICC-SS), was dramatically decreased to about 50% when compared with controls, but those Kit⁺ cells located at the submucosal border of circular smooth muscle layer (ICC-SM) seemed to be unchanged in both cell number and morphology. A small number of DOG1⁺/Kit⁻ cells appeared during Imatinib administration. However, these Kit⁺ ICC were not changed in mice even after 12 days of Imatinib treatment from P24. When Imatinib was discontinued, the number of ICC recovered to normal within 4 days. Our results indicate that the postnatal development of ICC in the mouse colon is Kit dependent, but ICC-SM are unlikely, and the Kit dependence of ICC development is also age-dependent.     

孕期亚硝酸盐暴露对仔鼠海马损伤的影响

目的 探讨孕期亚硝酸盐暴露对海马损伤的作用。 方法 利用C57BL/6J小鼠建立孕期亚硝酸盐暴露模型,分为对照组（生理盐水）、低剂量亚硝酸盐组（60mg/kg）和高剂量亚硝酸盐组(120mg/kg)。收集出生当日（P0）、P7、P14及P30各年龄点仔鼠大脑,用于免疫荧光染色、彗星实验、Western blotting蛋白半定量分析,对海马损伤进行研究。 结果 不论是亚硝酸盐暴露组还是对照组,仔鼠齿状回增殖的神经干细胞数目均随着年龄的增长逐渐减少;在P0、P7、P14和P30年龄点,暴露组仔鼠增殖的神经干细胞的数量明显比对照组少,且具有剂量依赖性（P<0.05,n=96）。为了鉴别这种抑制作用是否具有选择性,我们对P0仔鼠室管膜下区神经干细胞的增殖情况进行了观察。结果发现,亚硝酸盐暴露组室管膜下区的神经干细胞增殖较对照组也减少,同样具有剂量依赖性（P<0.05）;亚硝酸盐暴露组仔鼠门区炎症损伤细胞和凋亡细胞的数目比对照组多,具有剂量依赖性（P<0.05）;彗星实验结果显示,亚硝酸盐暴露组P0仔鼠海马细胞的彗尾比对照组长,具有剂量依赖性(P<0.01);与对照组P0仔鼠相比,亚硝酸盐暴露组仔鼠海马组织内Caspase-8和核因子κB（NF-κB）蛋白的表达量较高（P<0.05）。
结论 孕期亚硝酸盐暴露可通过抑制神经干细胞增殖,促进细胞损伤和凋亡而对仔鼠海马造成损伤。     

Proliferation and differentiation of progenitor cells in the cortex and the subventricular zone in the adult rat after focal cerebral ischemia

Progenitor cells in the subventricular zone of the lateral ventricle and in the dentate gyrus of the hippocampus can proliferate throughout the life of the animal. To examine the proliferation and fate of progenitor cells in the subventricular zone and dentate gyrus after focal cerebral ischemia, we measured the temporal and spatial profiles of proliferation of cells and the phenotypic fate of proliferating cells in ischemic brain in a model of embolic middle cerebral artery occlusion in the adult rat. Proliferating cells were labeled by injection of bromodeoxyuridine (BrdU) in a pulse or a cumulative protocol. To determine the temporal profile of proliferating cells, ischemic rats were injected with BrdU every 4 h for 12 h on the day preceding death. Rats were killed 2-14 days after ischemia. We observed significant increases in numbers of proliferating cells in the ipsilateral cortex and subventricular zone 2-14 days with a peak at 7 days after ischemia compared with the control group. To maximize labeling of proliferating cells, a single daily injection of BrdU was administered over a 14-day period starting the day after ischemia. Rats were killed either 2 h or 28 days after the last injection of BrdU. A significant increase in numbers of BrdU immunoreactive cells in the subventricular zone was coincident with a significant increase in numbers of BrdU immunoreactive cells in the olfactory bulb 14 days after ischemia and numbers of BrdU immunoreactive cells did not significantly increase in the dentate gyrus. However, 28 days after the last labeling, the number of BrdU labeled cells decreased by 90% compared with number at 14 days. Clusters of BrdU labeled cells were present in the cortex distal to the infarction. Numerous cells immunostained for the polysialylated form of the neuronal cell adhesion molecule were detected in the ipsilateral subventricular zone. Only 6% of BrdU labeled cells exhibited glial fibrillary acidic protein immunoreactivity in the cortex and subcortex and no BrdU labeled cells expressed neuronal protein markers (neural nuclear protein and microtubule associated protein-2). From these data we suggest that focal cerebral ischemia induces transient and regional specific increases in cell proliferation in the ipsilateral hemisphere and that proliferating progenitor cells may exist in the adult cortex.     

Solitary chemoreceptor cell proliferation in adult nasal epithelium

Nasal trigeminal chemosensitivity in mice and rats is mediated in part by solitary chemoreceptor cells (SCCs) in the nasal epithelium (Finger et al., 2003). Many nasal SCCs express the G-protein α-gustducin as well as other elements of the bitter-taste signaling cascade including phospholipase Cβ2, TRPM5 and T2R bitter-taste receptors. While some populations of sensory cells are replaced throughout life (taste and olfaction), others are not (hair cells and carotid body chemoreceptors). These experiments were designed to test whether new SCCs are generated within the epithelium of adult mice. Wild type C57/B6 mice were injected with the thymidine analog 5-bromo-2'-deoxyuridine (BrdU) to label dividing cells. At various times after injection (1–40 days), the mice were perfused with 4% paraformaldehyde and prepared for dual-label immunocytochemistry. Double labeled cells were detected as early as 3 days post BrdU injection and remained for as long as 12 days post-injection suggesting that SCCs do undergo turnover like the surrounding nasal epithelium. No BrdU labeled cells were detected after 24 days suggesting relatively rapid replacement of the SCCs. This work is dedicated to Al Farbman, a pioneering figure in studies of both the gustatory and olfactory epithelia. He is the rarest of individuals, an esteemed academic, an enthusiastic scientist, and a true gentleman.     

局灶性脑缺血后老年大鼠室管膜下区和颗粒下层细胞增殖与分化的实验研究

目的观察老年大鼠局灶性脑缺血后室管膜下区（SVZ）和颗粒下层（SGZ）神经干细胞的增殖与分化.方法取老年大鼠制作大脑中动脉梗塞模型.用5-溴脱氧尿核苷（BrdU）脉冲标记结合免疫组织化学单标记技术,观察正常组、假手术组、脑缺血后3、7、14、21、28 d组SVZ和SGZ区BrdU阳性细胞的变化;用BrdU累积标记结合免疫组织化学双标技术,观察脑缺血14 d后SVZ和SGZ区BrdU/NeuN和BrdU/GFAP双标阳性细胞的数量.结果在正常组、假手术组及各脑缺血组大鼠的双侧SVZ和SGZ均可观察到BrdU阳性细胞.与正常组和假手术组相比,脑缺血后SVZ和SGZ区BrdU阳性细胞明显增加.缺血组SVZ区BrdU阳性细胞在脑缺血后7 d时达到高峰,28 d时仍高于正常水平;SGZ区BrdU阳性细胞在脑缺血后14 d时达到高峰,28 d时仍高于正常水平.通过BrdU累积标记和免疫组织化学双标发现：脑缺血14 d后,老年大鼠SVZ区有部分细胞显示BrdU/NeuN（0.98%）或BrdU/GFAP（12.56%）双标阳性,而SGZ区未见双标细胞.结论局灶性脑缺血可激活老年大鼠室管膜下区和颗粒下层的神经干细胞明显增殖,并且室管膜下区有部分增殖细胞可分化为神经元或神经胶质.     

Plasticity of Interstitial Cells of Cajal: A Study in the Small Intestine of Adult Guinea Pigs

Although it is well known that the reduction of interstitial cells of Cajal (ICCs) is associated with several gastrointestinal motility disorders in clinic, it is unknown whether the mature ICCs still have an active plasticity in adult mammals. This study focused on the issues of the reduction of ICCs during Imatinib administration and the recovery of ICCs following drug withdrawal in the small intestine of adult guinea pigs. ICCs were revealed by immunofluorescence on whole mount preparations with anti‐Kit, α‐smooth muscle actin, (α‐SMA), and 5‐bromo‐2′‐deoxyuridine (BrdU) antibodies. Moreover, the occurrence of apoptosis was also assayed. Imatinib treatment led to a gradual reduction of ICCs in number around the myenteric plexus and deep muscular plexus, which was dependent on the time but no apoptosis of ICCs was detected with the TUNEL method. During Imatinib treatment, some ICC‐like cells were double labeled for Kit and α‐SMA and a few ICC‐like cells were only stained with α‐SMA. When Imatinib was discontinued, the number of ICCs recovered to normal within 32 days. During this time, some proliferating ICCs were demonstrated by double labeling with Kit and BrdU antibodies. Our results indicated that Kit signaling was essential for the maintenance of survival and proliferation of the mature ICCs in the small intestine of adult guinea pigs. Moreover, ICCs might transdifferentiate to a type of α‐SMA⁺ cells, perhaps a phenotype of smooth muscle cells, when there is a loss‐of‐function of Kit. Anat Rec, 292:985–993, 2009. © 2009 Wiley‐Liss, Inc.     

Time-specific blockade of PDGFR with Imatinib (Glivec®) causes cataract and disruption of lens fiber cells in neonatal mice

This study aimed at investigating the response of lens epithelial cells in postnatal mice to Imatinib (Glivec?, a potent inhibitor of platelet-derived growth factor receptor (PDGFR)) treatment. Mouse eyes were sampled 10 days after administration of Imatinib (0.5 mg·g⁻¹·day⁻¹) for 3 days, at either 7, 14, or 21 days postpartum. Structural changes of lens were revealed by routine H.E. staining. Levels of proliferation and apoptosis were revealed by BrdU incorporation and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, respectively, and immunofluorescent staining with anti-PDGFRα antibody was carried out on the sections of eyeball. PDGFRα and p-PDGFRαprotein levels were evaluated by Western blot. Our results indicated that administration of Imatinib led to blockade of PDGFR signaling. Formation of cataracts was found only in those mice where treatment started from 7 days postpartum (P7), but was not observed in those samples from P14 nor P21. Fiber cells were disorganized in cataract lens core as observed histologically, and migration of epithelial cells was also inhibited. No apoptosis was detected with the TUNEL method. Our results indicated blockade of PDGFR at the neonatal stage (P7) would lead to cataracts and lens fiber cells disorganization, suggesting that PDGFR signaling plays a time-specific and crucial role in the postnatal development of lens in the mouse, and also may provide a new approach to produce a congenital cataract animal model.