神经元-胶质细胞共生体系对神经营养因子活性影响的研究现状

视网膜色素变性的病理特点是感光细胞和视网膜色素上皮细胞结构和功能的进行性丧失。神经营养因子对其保护作用越来越受到关注。脑源性神经营养因子、睫状神经营养因子和胶质细胞源性神经营养因子可通过直接和间接保护通路影响感光细胞活性。而神经元-胶质细胞共生体系介导的对感光细胞活性的间接保护作用更为重要。胶质细胞介导的神经营养因子治疗相关眼病取得了部分进展，这将为延缓视网膜色素变性病情发展提供一种新的有效手段。     

神经营养因子治疗视网膜色素变性的研究进展

神经营养因子是能够促进神经元存活、生长、分化及维持其功能的多效性肽类因子的总称,可被作为有效的神经保护剂用于治疗多种神经变性类疾病.视网膜色素变性(RP)是以光感受器-视网膜色素上皮复合体损害为主的高度遗传异质性视网膜变性疾病,神经营养因子作为不针对致病基因的RP治疗策略,其疗效已在多种视网膜变性的动物模型中得到证实.以病毒为载体的转基因治疗和细胞包囊技术为神经营养因子提供了有效的给药途径,可使疗效明显提高.对神经营养因子在视网膜中的表达及其调节、受体分布特点、作用通路、疗效及副作用等方面的深入研究为神经营养因子的临床应用奠定了基础.     

神经营养因子治疗视网膜色素变性的研究进展

神经营养因子是能够促进神经元存活、生长、分化及维持其功能的多效性肽类因子的总称,可被作为有效的神经保护剂用于治疗多种神经变性类疾病.视网膜色素变性(RP)是以光感受器-视网膜色素上皮复合体损害为主的高度遗传异质性视网膜变性疾病,神经营养因子作为不针对致病基因的RP治疗策略,其疗效已在多种视网膜变性的动物模型中得到证实.以病毒为载体的转基因治疗和细胞包囊技术为神经营养因子提供了有效的给药途径,可使疗效明显提高.对神经营养因子在视网膜中的表达及其调节、受体分布特点、作用通路、疗效及副作用等方面的深入研究为神经营养因子的临床应用奠定了基础.     

视网膜色素变性的实验研究进展

视网膜色素变性是一种遗传性眼病,遗传方式包括常染色体显性遗传、常染色体隐性遗传及性连锁隐性遗传等,目前已知的突变位点超过3 000个,造成本病临床治疗困难。眼科学者致力于探索视网膜色素变性的治疗方式,进行了大量实验研究,主要有药物治疗、细胞移植、基因治疗等治疗方式。药物治疗包括中药、抗氧化剂、抗凋亡剂、神经营养因子等,与其它治疗方式相比,无侵入性,且方便价廉,但其作用机制尚需更深入的研究。细胞移植被认为是治疗视网膜色素变性的有效方法,但有可能引起视网膜前膜及黄斑皱褶。基因治疗虽然存在一定的局限性,但随着基因编辑技术和新型基因递送载体的发展,未来会成为视网膜色素变性最有希望的治疗方式之一。本文对近年来视网膜色素变性的实验研究进行了综述与展望。     

睫状神经营养因子对视网膜色素变性中感光细胞的作用

遗传性视网膜色素变性类疾病是人类的主要致盲眼病之一,目前尚无有效阻止病变进展和恢复视网膜功能的治疗方法.此类疾病的最后结果是感光细胞不可逆的凋亡.阻断感光细胞走向凋亡的进程是近年来研究的热点.在大量的体内外实验中发现,很多神经生长因子对遗传性视网膜色素变性类疾病有一定的治疗作用,其中睫状神经营养因子保护感光细胞、延缓感光细胞凋亡的作用颇受关注.本文就近年来睫状神经营养因子对视网膜色素变性疾病中感光细胞的作用研究作一综述.     

视网膜色素变性治疗研究进展

视网膜色素变性(retinitis pigmentosa,RP)是一组遗传性视网膜疾病,其特征是渐进性感光细胞和视网膜色素上皮(RPE)细胞功能障碍,是世界范围内常见的致盲性眼病,且缺乏有效的治疗方法。目前RP的治疗方法包括干细胞治疗、基因治疗、神经保护治疗、营养疗法、高压氧疗法、视网膜移植和中医治疗。本文综述了近年来国内外有关RP治疗的研究进展。     

原发性视网膜色素变性抗凋亡治疗研究进展

视网膜色素变性的病理学基础是色素上皮细胞和锥杆细胞的渐进性死亡。这些细胞的死亡是经过凋亡的形式完成的。bcl—2和睫状神经营养因子能抑制这种自然进程的的凋亡。本文从抗细胞凋亡的角度综述了视网膜色素变性的基因治疗。     

胶质细胞源性神经营养因子干预视网膜色素变性给药方式的研究进展

视网膜色素变性（retinitis pigmentosa，RP）的治疗目前仍处于探索阶段。胶质细胞源性神经营养因子（glial cell line-derived neurotrophic factor，GDNF）是目前研究中重要的神经营养因子，但其传统给药方式生物利用度相对较低。近年来GDNF安全有效的给药方式成为研究热点，包括经病毒载体或非病毒载体的基因工程法释药技术、经聚合物释放系统释药技术、经细胞移植释药技术、小分子触发器诱导产生GDNF等。本文就GDNF干预RP的给药方式进行综述。     

神经营养因子治疗视网膜色素变性的研究进展

目前为止发现了30余种视网膜色素变性(RP)的致病相关基因,发病机制研究提示凋亡可能是它们引起光感受器细胞萎缩的共同病理途径。神经营养因子是一类对神经系统的分化、发育,对神经元的存活,轴突再生均有重要作用的细胞因子。它们可能通过调控视网膜光感受器细胞的凋亡过程起到神经保护作用,有望成为治疗RP的有效药物。本文对近年来神经营养因子的光感受器保护作用、给药途径、治疗机制、副作用等方面的研究状况进行综述,其中基因工程改造的神经营养因子和基因修饰细胞半透膜埋植系统的研究取得了进展。     

虹膜色素上皮移植

自体虹膜色素上皮容易获得，能够吞噬光感受器外节盘膜，使得用它替代视网膜色素上皮细胞移植到视网膜下腔以治疗视网膜色素上皮变性疾病成为可能。对IPE和视网膜色素上皮(RPE)细胞的功能进行了比较，并对IPE细胞的培养方法，用IPE细胞移植治疗老年性黄斑变性和视网膜色素变性等技术进行了综述。     

视网膜色素变性研究新进展

视网膜色素变性(retinitis pigmentosa,RP)也称为色素性视网膜炎。RP是由于视网膜色素上皮细胞功能逐渐丧失及光感受器进行性凋亡从而导致不可逆的视力损伤的一组遗传性眼病。因其表型和遗传均具有异质性,发病机制复杂,目前尚无单一有效的治疗方法。本文报告近年来RP在诊疗方面的进展。     

Retinosis pigmentaria sine pigmento. Inicio con edema macular

Case reportA 25-year-old woman, with metamorphopsia in her left eye of one year onset. The examination revealed a bilateral cystoid macular oedema (CME) and vascular attenuation. We describe the diagnostic tests, as well as differential diagnosis and treatment response with carbonic anhydrase inhibitors.DiscussionThe retinitis pigmentosa sine pigment is a subtype of atypical retinitis pigmentosa characterised by the absence of pigment deposits. The night blindness is milder, and perimetric and electroretinographic impairment is lower. CME is an important cause of central vision loss, and responds to anhydrase carbonic inhibitors.     

Acuity recovery and cone pigment regeneration after a bleach in patients with retinitis pigmentosa and rhodopsin mutations.

PURPOSE: To assess visual acuity recovery times and cone photopigment regeneration kinetics after a bleach in the fovea of patients with dominant retinitis pigmentosa due to rhodopsin mutations. METHODS: The authors measured acuity recovery times by computerized photostress testing in 13 patients with dominant retinitis pigmentosa and one of eight rhodopsin mutations. The authors also measured their time constants of cone photopigment regeneration with a video imaging fundus reflectometer to determine whether acuity recovery time depended on pigment regeneration kinetics. These values were compared with those of normal subjects, by the Mann-Whitney U test. The relationship between acuity recovery time and the time constant of cone photopigment regeneration among the patients was quantified by the Spearman rank correlation. RESULTS: The visual acuity recovery times, which averaged 22.0 seconds for the patients with retinitis pigmentosa and 11.2 seconds for the normal subjects, were significantly slower for the patient group (P < 0.001). The time constants of cone pigment regeneration, which averaged 172 seconds for the patients with retinitis pigmentosa and 118 seconds for the normal subjects, also were significantly slower for the patient group (P = 0.043). The authors also found a significant, positive correlation between the visual acuity recovery time and the time constant of pigment regeneration for the patients with retinitis pigmentosa (r = 0.65, P = 0.017). CONCLUSIONS: A slowing of foveal visual acuity recovery and cone pigment regeneration, which are related to each other, can occur in patients with retinitis pigmentosa, due to a rod-specific gene defect.     

Prevalence of retinitis pigmentosa in urban and rural adult Chinese: The Beijing Eye Study

PURPOSE: To determine the prevalence of retinitis pigmentosa in the elderly Chinese population. METHODS: The Beijing Eye Study is a population-based, cross-sectional cohort study and included 4439 subjects out of 5324 subjects invited to participate (response rate 83.4%) with an age of 40+ years. Readable fundus photographs were available for 4027 (90.7%) subjects. Diagnostic criteria for retinitis pigmentosa were visual field defects on frequency doubling perimetry, typical ophthalmoscopic abnormalities such as retinal pigment deposits, retinal arteriole attenuation, and pigment epithelial atrophy, and no other reason for perimetric defects and fundus abnormalities. RESULTS: Retinitis pigmentosa was diagnosed in four subjects (all men). Its prevalence was 0.099+/-3.15% (95% CI: 0.00, 0.2). CONCLUSIONS: Retinitis pigmentosa with typical fundus appearance and functional loss may be present in about 1 out of 1000 elderly Chinese in Northern China. Calculated for the whole population in China, the figure would be 1.3 million patients with retinitis pigmentosa.     

Preserved para-arteriolar retinal pigment epithelium retinitis pigmentosa.

In two patients, we studied retinitis pigmentosa with preservation of the retinal pigment epithelium adjacent to and under the retinal arterioles (despite panretinal degeneration). Both patients with preserved para-arteriolar retinal pigment epithelium also exhibited a peculiarly strong hyperopia. In addition to previously reported features, these patients also had sheathing of the major vascular arcades, which suggested a vascular involvement in this uncommon form of retinitis pigmentosa.     

Early-onset autosomal dominant retinitis pigmentosa with severe hyperopia

We studied a four-generation family with early-onset autosomal dominant retinitis pigmentosa, severe hyperopia, and axial eye lengths of less than 20 mm. The affected members had decreased vision, night blindness, typical peripheral retinal pigmentary changes, and electroretinographic abnormalities characteristic of retinitis pigmentosa. This pedigree suggests there is another variant of retinitis pigmentosa associated with hyperopia besides Leber's congenital amaurosis and preserved para-arteriole retinal pigment epithelium.     

Normal interaction of plasma retinol-binding protein from retinitis pigmentosa with bovine pigment epithelium.

The interaction between retinol-binding protein and normal bovine pigment epithelium has been studied with the use of iodinated retinol-binding protein isolated from the plasma of patients with the recessive form of retinitis pigmentosa and of normal subjects. It is concluded that the capacity of the plasma carrier protein to interact with the retinol-binding protein receptor of bovine pigment epithelium is unimpaired in retinitis pigmentosa with autosomal recessive inheritance.     

Vitreous fluorophotometry studies in retinitis pigmentosa

Six patients with various genetic types of retinitis pigmentosa and ten carriers of the X-linked recessive type were studied by vitreous fluorophotometry. Kinetic vitreous fluorophotometry showed an alteration of the blood-retinal barrier (BRB) in patients with retinitis pigmentosa, even in those who had minimal fundoscopic abnormalities and only minor changes on the electroretinogram. Furthermore, an alteration of the BRB could be detected in the carriers of the X-linked recessive form of retinitis pigmentosa. In general, higher concentration of fluorescein in the vitreous correlated topographically with the extent of photoreceptor and retinal pigment epithelial disease, as well as with the presence of leakage from retinal capillaries.     

RRH, encoding the RPE-expressed opsin-like peropsin, is not mutated in retinitis pigmentosa and allied diseases

Many genes from retinoid metabolism cause retinitis pigmentosa. Peropsin, an opsin-like protein with unknown function, is specifically expressed in apical retinal pigment epithelium microvilli. Since rhodopsin and RGR, another opsin-like protein, cause retinitis pigmentosa, we used D-HPLC to screen for the peropsin gene RRH in 331 patients (288 with retinitis pigmentosa and 82 with other retinal dystrophies). We found 13 nonpathogenic variants only, among which a c.730_731delATinsG that truncates the last two transmembrane-spanning fragments and the Lys284 required for retinol binding, but does not segregate with the disease phenotype. We conclude that RRH is not a frequent gene in retinitis pigmentosa.