Spatial electron-spin splitting in single-layered semiconductor microstructure modulated by Dresselhaus spin-orbit coupling

Combining theory and computation,we explore the Goos–H¨anchen(GH)effect for electrons in a single-layered semiconductor microstructure(SLSM)modulated by Dresselhaus spin–orbit coupling(SOC).GH displacement depends on electron spins thanks to Dresselhaus SOC,therefore electron spins can be separated from the space domain and spinpolarized electrons in semiconductors can be realized.Both the magnitude and sign of the spin polarization ratio change with the electron energy,in-plane wave vector,strain engineering and semiconductor layer thickness.The spin polarization ratio approaches a maximum at resonance;however,no electron-spin polarization occurs in the SLSM for a zero in-plane wave vector.More importantly,the spin polarization ratio can be manipulated by strain engineering or semiconductor layer thickness,giving rise to a controllable spatial electron-spin splitter in the field of semiconductor spintronics.

Lycium barbarum glycopeptide(wolfberry extract)slows N-methyl-N-nitrosourea-induced degradation of photoreceptors

Photoreceptor cell degeneration leads to blindness, for which there is currently no effective treatment. Our previous studies have shown that Lycium barbarum(L. barbarum) polysaccharide(LBP) protects degenerated photoreceptors in rd1, a transgenic mouse model of retinitis pigmentosa. L. barbarum glycopeptide(Lb GP) is an immunoreactive glycoprotein extracted from LBP. In this study, we investigated the potential protective effect of Lb GP on a chemically induced photoreceptor-degenerative mouse model. Wild-type mice received the following: oral administration of Lb GP as a protective pre-treatment on days 1–7;intraperitoneal administration of 40 mg/kg N-methylN-nitrosourea to induce photoreceptor injury on day 7;and continuation of orally administered Lb GP on days 8–14. Treatment with Lb GP increased photoreceptor survival and improved the structure of photoreceptors, retinal photoresponse, and visual behaviors of mice with photoreceptor degeneration. Lb GP was also found to partially inhibit the activation of microglia in N-methyl-N-nitrosourea-injured retinas and significantly decreased the expression of two pro-inflammatory cytokines. In conclusion, Lb GP effectively slowed the rate of photoreceptor degeneration in N-methyl-N-nitrosourea-injured mice, possibly through an anti-inflammatory mechanism, and has potential as a candidate drug for the clinical treatment of photoreceptor degeneration.

Protective effects of CY-09 and astaxanthin on NaIO_(3)-induced photoreceptor inflammation via the NLRP3/autophagy pathway

AIM:To study the effect of the NLRP3/autophagy pathway on the photoreceptor inflammatory response and the protective mechanism of CY-09 and astaxanthin(AST).METHODS:ICR mice were intraperitoneally injected NaIO_(3),CY-09,AST successively and divided into 5 groups,including the control,NaIO_(3),NaIO_(3)+CY-09,NaIO_(3)+AST,and NaIO_(3)+CY-09+AST groups.Spectral domain optical coherence tomography and flash electroretinogram were examined and the retina tissues were harvested for immunohistochemistry,enzyme linked immunosorbent assay(ELISA),and Western blotting.Retinal pigment epithelium cell line(ARPE-19 cells)and mouse photoreceptor cells line(661W cells)were also treated with NaIO_(3),CY-09,and AST successively.Cell proliferation was assessed by cell counting kit-8(CCK-8)assay.Apoptosis was analyzed by flow cytometry.Changes in autophagosome morphology were observed by transmission electron microscopy.Quantitative polymerase chain reaction(qPCR)was used to detect NLRP3 and caspase-1.NLRP3,caspase-1,cleaved caspase-1,p62,Beclin-1,and LC3 protein levels were measured by Western blotting.IL-1βand IL-18 were measured by ELISA.RESULTS:Compared with the control group,the activity of NaIO_(3)-treated 661W cells decreased within 24 and 48h,apoptosis increased,NLRP3,caspase-1,IL-1βand IL-18 levels increased,and autophagy-related protein levels increased(P<0.05).Compared with NaIO_(3) group,CY-09 and AST inhibited apoptosis(P<0.05),reduced NLRP3,caspase-1,IL-1βand IL-18 expression(P<0.05),and inhibited autophagy.Compared with the other groups,CY-09 combined with AST significantly decreased NLRP3 expression and inhibited the expression of the autophagy-related proteins p62,Beclin-1,and LC3 in vitro and in vivo(P<0.05).CONCLUSION:CY-09 and AST inhibit NaIO_(3)-induced inflammatory damage through the NLRP3/autophagy pathway in vitro and in vivo.CY-09 and AST may protect retina from inflammatory injury.

Optimal transcorneal electrical stimulation parameters for preserving photoreceptors in a mouse model of retinitis pigmentosa

Retinitis pigmentosa is a hereditary retinal disease that affects rod and cone photoreceptors,leading to progressive photoreceptor loss.Previous research supports the beneficial effect of electrical stimulation on photoreceptor survival.This study aims to identify the most effective electrical stimulation parameters and functional advantages of transcorneal electrical stimulation(tcES)in mice affected by inherited retinal degeneration.Additionally,the study seeked to analyze the electric field that reaches the retina in both eyes in mice and post-mortem humans.In this study,we recorded waveforms and voltages directed to the retina during transcorneal electrical stimulation in C57BL/6J mice using an intraocular needle probe with rectangular,sine,and ramp waveforms.To investigate the functional effects of electrical stimulation on photoreceptors,we used human retinal explant cultures and rhodopsin knockout(Rho^(-/-))mice,demonstrating progressive photoreceptor degeneration with age.Human retinal explants isolated from the donors’eyes were then subjected to electrical stimulation and cultured for 48 hours to simulate the neurodegenerative environment in vitro.Photoreceptor density was evaluated by rhodopsin immunolabeling.In vivo Rho^(-/-)mice were subjected to two 5-day series of daily transcorneal electrical stimulation using rectangular and ramp waveforms.Retinal function and visual perception of mice were evaluated by electroretinography and optomotor response(OMR),respectively.Immunolabeling was used to assess the morphological and biochemical changes of the photoreceptor and bipolar cells in mouse retinas.Oscilloscope recordings indicated effective delivery of rectangular,sine,and ramp waveforms to the retina by transcorneal electrical stimulation,of which the ramp waveform required the lowest voltage.Evaluation of the total conductive resistance of the post-mortem human compared to the mouse eyes indicated higher cornea-to-retina resistance in human eyes.The temperature recordings during and after electrical stimulation indicated no significant temperature change in vivo and only a subtle temperature increase in vitro(~0.5-1.5°C).Electrical stimulation increased photoreceptor survival in human retinal explant cultures,particularly at the ramp waveform.Transcorneal electrical stimulation(rectangular+ramp)waveforms significantly improved the survival and function of S and M-cones and enhanced visual acuity based on the optomotor response results.Histology and immunolabeling demonstrated increased photoreceptor survival,improved outer nuclear layer thickness,and increased bipolar cell sprouting in Rho^(-/-)mice.These results indicate that transcorneal electrical stimulation effectively delivers the electrical field to the retina,improves photoreceptor survival in both human and mouse retinas,and increases visual function in Rho^(-/-)mice.Combined rectangular and ramp waveform stimulation can promote photoreceptor survival in a minimally invasive fashion.

Ultra-thin circularly polarized lens antenna based on single-layered transparent metasurface

Circularly polarized （CP） lens antenna has been applied to numerous wireless communication systems based on its unique advantages such as high antenna gain, low manufacturing cost, especially stable data transmission between the transmitter and the receiver. Unfortunately, current available CP lens antennas mostly suffer from high profile, low aperture efficiency as well as complex design. In this paper, we propose an ultra-thin CP lens antenna based on the designed single- layered Pancharatnam-Berry （PB） transparent metasurface with focusing property. The PB metasurface exhibits a high transmissivity, which ensures a high efficiency of the focusing property. Launched the metasurface with a CP patch antenna at its focal point, a low-profile lens antenna is simulated and measured. The experimental results show that our lens antenna exhibits a series of advantages including high radiation gain of 20.7 dB, aperture efficiency better than 41.3%, and also narrow half power beam width （HPBW） of 13°at about 14GHz. Our finding opens a door to realize ultra-thin transparent metasurface with other functionalities or at other working frequencies.

Preliminary analysis of mode truncation of single-layered reticulated domes under earthquakes

In anti-seismic calculation, the mode truncation is a significant problem to engineers if the mode-superposition response spectrum method is used, which has not been completely solved yet in some large and complex structures such as reticulated domes. In this case, some useful advices, concentrating on the problem above, are expected through a careful and comprehensive investigation of this paper. During the investigation, the authors first point out shortcomings of former researches. Then frequency-spectrum characteristics of single-layered reticulated domes were studied from the perspective of structural responses. During this process, some important results such as the existence of the main resonant section, and the fact that the relative sensitivity of these domes under horizontal and vertical impulse varies with the different R/S ratios were achieved. Furthermore, based on the study of frequency-spectrum characteristics, as well as that of earthquake input, reasonable numbers of mode truncation in single layered reticulated domes with different R/S ratio were presented. Results of case studies prove the mode truncation number proposed is valid.

Nanoscale mass sensing based on vibration of single-layered graphene sheet in thermal environments

Based on vibration analysis, single-layered graphene sheet （SLGS） with multiple attached nanoparticles is developed as nanoscale mass sensor in thermal environments. Graphene sensors are assumed to be in simplysupported configuration. Based on the nonlocal plate the- ory which incorporates size effects into the classical theory, closed-form expressions lot the frequencies and relative fre- quency shills of SLGS-based mass sensor are derived using the Galerkin method. The suggested model is justified by a good agreement between the results given by the present model and available data in literature. The effects of tem- perature difference, nonlocal parameter, the location of the nanoparticle and the number of nanoparticles on the relative frequency shift of the mass sensor are also elucidated. The obtained results show that the sensitivity of the SLGS- based mass sensor increases with increasing temperature difference.

Neural and Müller glial adaptation of the retina to photoreceptor degeneration

The majority of inherited retinal degenerative diseases and dry age-related macular degeneration are characterized by decay of the outer retina and photoreceptors,which leads to progressive loss of vision.The inner retina,including second-and third-order retinal neurons,also shows aberrant structural changes at all stages of degeneration.Müller glia,the major glial cells maintain retinal homeostasis,activating and rearranging immediately in response to photoreceptor stress.These phenomena are collectively known as retinal remodeling and are anatomically well described,but their impact on visual function is less well characterized.Retinal remodeling has traditionally been considered a detrimental chain of events that decreases visual function.However,emerging evidence from functional assays suggests that remodeling could also be a part of a survival mechanism wherein the inner retina responds plastically to outer retinal degeneration.The visual system’s first synapses between the photoreceptors and bipolar cells undergo rewiring and functionally compensate to maintain normal signal output to the brain.Distinct classes of retinal ganglion cells remain even after the massive loss of photoreceptors.Müller glia possess the regenerative potential for retinal recovery and possibly exert adaptive transcriptional changes in response to neuronal loss.These types of homeostatic changes could potentially explain the well-maintained visual function observed in patients with inherited retinal degenerative diseases who display prominent anatomic retinal pathology.This review will focus on our current understanding of retinal neuronal and Müller glial adaptation for the potential preservation of retinal activity during photoreceptor degeneration.Targeting retinal self-compensatory responses could help generate universal strategies to delay sensory disease progression.

Deposition mechanism of nano-structured single-layered C_(36) film on a diamond (100) crystal plane

The Brenner-LJ potential is adopted to describe the interaction between C36 clusters and diamond surface, and the deposition mechanism of multi-C36 clusters on the diamond surface is also studied by using the method of molecular dynamics simulation. The simulation results show that the competition effects of two interactions, i.e. the interaction between cluster and cluster and the interaction between cluster and crystal plane, are studied, and then the influence of these competition effects on C36 cluster deposition is analysed. The finding is that when an incident energy is appropriately chosen, C36 clusters can be chemically adsorbed and deposited steadily on the diamond surface in the form of single-layer, and in the deposition process the multi-C36 clusters present a phenomenon of energy transmission. The experimental result shows that at a temperature of 300K, in order to deposit C36 clusters into a steady nanostructured single-layered film, the optimal incident energy is between 10 and 18 eV, if the incident energy is larger than 18 eV, the C36 clusters will be deposited into an island nano-structured film.

Photoreceptor changes in Leber hereditary optic neuropathy with m.G11778A mutation

·AIM:To evaluate the functional and structural changes of photoreceptors in patients and asymptomatic carriers with Leber hereditary optic neuropathy(LHON)using fullfield electroretinography(FERG)and optical coherence tomography(OCT).·METHODS:Individuals diagnosed with LHON at the Renmin Hospital of Wuhan University and their family members were included in this cross-sectional observational study.The FERG a-wave amplitude of affected patients and asymptomatic carriers was analyzed.The thickness of the outer nuclear layer(ONL),inner and outer segment(IS/OS)and total photoreceptors in the macular fovea and parafovea were measured.·RESULTS:This study included 14 LHON patients(mean age:20.00±9.37y),12 asymptomatic carriers(mean age:39.83±6.48y),and 14 normal subjects(mean age:24.20±1.52y).The FERG results showed that the darkadapted 3.0 electroretinography and light-adapted 3.0 electroretinography a-wave amplitudes of patients and carriers were significantly decreased(P<0.001).The ONL and photoreceptors layers were slightly thicker in patients than in normal subjects(P<0.05),whereas they were thinner in carriers(P<0.05).There were no differences in IS/OS thickness among the groups(P>0.05).·CONCLUSION:Photoreceptors function is significantly impaired in LHON-affected patients and asymptomatic carriers.Meanwhile,photoreceptors morphology is slightly altered,mainly manifesting as a change in ONL thickness.

Lower Bounds of Decay Rates for Solution to the Single-Layer Quasi-Geostrophic Model

In this paper, we study the long-time behavior of solutions of the single-layer quasi-geostrophic model arising from geophysical fluid dynamics. We obtain the lower bound of the decay estimate of the solution. Utilizing the Fourier splitting method, under suitable assumptions on the initial data, for any multi-index α, we show that the solution Ψ satisfies .

提高移植光感受器功能性整合的策略

视网膜退行性疾病的最终结局是光感受器的大量丢失,造成视力不可逆的损害,目前基本上无有效治疗措施。光感受器移植为一种潜在的细胞治疗手段,旨在通过替换丢失的光感受器,重建视网膜回路,在一定程度上帮助恢复视网膜功能。然而,物质交换机制的发现揭示了既往研究结果中移植光感受器的整合比例低、外段形成不足及突触形成不够等问题,显示了该疗法临床转化的难度。本文通过多个维度综述了提高移植光感受器功能性整合的策略,探究相关内容的可行性,具体包括选择最佳发育时间窗的移植细胞群,增强与宿主视网膜间的相互作用;破坏宿主外界膜,减轻视网膜重塑,提高移植细胞的迁移及整合;利用免疫调节,减少小胶质细胞活化,改善宿主的移植微环境;通过视网膜片或生物支架的移植形式,提高移植光感受器的组织性;合理地开发及使用生物材料,优化移植细胞的生理微环境;充分评估手术参数,降低手术本身对移植细胞及宿主视网膜的影响。

BLUF蛋白TePixD Y8F突变体的结构

目的TePixD(Tll0078)是一种来自细长嗜热聚球藻(Thermosynechococcus elongatus BP-1)的blue light-using flavin(BLUF)感光蛋白。TePixD蛋白在FAD口袋周围有一个保守的Tyr8-Gln50-Met93三联体,以介导质子偶联电子转移(proton-coupled electron transfer,PCET)过程。但具体的光响应机制有待进一步研究。本文的目的是解析TePixD在光响应关键位点突变体的结构以及生化性质,以此分析TePixD的光响应过程。方法利用X射线衍射法解析TePixD Y8F突变体的晶体结构,Tyr8侧链在PCET过程中有重要作用,而突变体Phe8的侧链失去了羟基从而使分子无法介导PCET。本文比较了TePixD野生型和Y8F突变体之间的结构,并比较了同蛋白家族的SyPixD Y8F与TePixD Y8F的结构。此外,使用多角度光散射法分析几种TePixD在光响应关键位点突变体(Y8F、Q50L、W91F、Y8F/W91F和Q50L/W91F)在溶液中的生化特性。结果本文以2.54Å分辨率解析了TePixD Y8F突变体的晶体结构,发现其与TePixD野生型的整体结构相似,而与SyPixD Y8F存在显著差异。生化分析表明,对比黑暗和光照条件时,TePixD突变体与野生型的分子质量变化以及洗脱峰表现出差异,表明突变体对光诱导蛋白质构象变化产生干扰。结论本文的结构测定和生化分析为揭示BLUF蛋白的光响应机制提供了新信息。

Taurine: a promising nutraceutic in the prevention of retinal degeneration

Taurine is considered a non-essential amino acid because it is synthesized by most mammals.However,dietary intake of taurine may be necessary to achieve the physiological levels required for the development,maintenance,and function of certain tissues.Taurine may be especially important for the retina.The concentration of taurine in the retina is higher than that in any other tissue in the body and taurine deficiency causes retinal oxidative stress,apoptosis,and degeneration of photoreceptors and retinal ganglion cells.Low plasma taurine levels may also underlie retinal degeneration in humans and therefore,taurine administration could exert retinal neuroprotective effects.Taurine has antioxidant,anti-apoptotic,immunomodulatory,and calcium homeostasis-regulatory properties.This review summarizes the role of taurine in retinal health and disease,where it appears that taurine may be a promising nutraceutical.

视网膜中小胶质细胞对光感受器细胞的作用

小胶质细胞作为视网膜的固有免疫细胞,能够主动监测周围微环境的变化。光感受器细胞作为视网膜的一级神经元,能够将光信号转换为电信号。在视网膜的多种生理、病理环境中,小胶质细胞对光感受器细胞的功能或存活具有重要影响。在视网膜发育过程中,小胶质细胞吞噬细胞碎片、促进神经发生及突触塑形。在健康视网膜环境中,小胶质细胞能够维持内环境稳定、维持神经元突触结构和功能、分泌营养因子。关于视网膜疾病的研究,既往多关注小胶质细胞的损害作用。随着研究进展发现,在视网膜急性损伤和应激(视网膜脱离、朊病毒损伤、光损伤)中,小胶质细胞对光感受器细胞的保护作用大于损害作用。在视网膜慢性炎性疾病,如视网膜色素变性、年龄相关性黄斑变性、糖尿病视网膜病变中,免疫微环境失衡,小胶质细胞被过度激活,释放大量炎性因子,吞噬非凋亡光感受器细胞,其损害作用大于保护作用。如何发挥小胶质细胞的保护作用而抑制其损害作用,对视网膜疾病,尤其是慢性炎性疾病的治疗具有重要意义。本文就不同视网膜条件下小胶质细胞对光感受器细胞的作用进行综述。

光敏色素A调控光响应基因表达及其翻译后修饰研究进展

光是调节植物生长发育最重要的环境信号因子之一。植物通过光受体感受自然环境中光的强度、方向以及光周期等信号的变化,从而调控其生长发育过程。光敏色素A(phytochrome A,PHYA)是植物中唯一的远红光受体蛋白,具有在黑暗下在细胞质中合成,而在照光后快速入核和降解的特性,并通过多种途径精确调节了植物光响应基因的转录网络。同时,蛋白质翻译后修饰在调节PHYA稳定性和活性的过程中发挥了重要的作用。该文论述了PHYA调节光响应基因表达以及PHYA翻译后修饰方向的研究进展,并展望了PHYA在农作物分子设计育种中的应用前景。

内质网应激在视网膜色素变性中的作用

视网膜色素变性(RP)是以光感受器及色素上皮功能丧失为特征的退行性致盲疾病。内质网应激的激活是细胞的防御调节机制,旨在通过一系列分子信号通路进行自我调节以恢复内质网功能的稳定。视紫红质突变是RP的常见病因,内质网内视紫红质错误折叠和滞留,内质网应激诱发感光细胞和视网膜色素上皮细胞凋亡,均可导致RP的发生和发展。文章论述了内质网应激与其在RP发病机制中的作用,并对内质网应激抑制剂、中药和化学药物调控内质网应激在RP治疗中的作用进行总结,以期为内质网应激在RP的临床应用中提供理论依据,为RP的研究、预防和治疗提供新的思路。

磷酸戊糖途径抑制感光细胞凋亡及分子机制的研究进展

感光细胞是一种特殊的神经上皮细胞,在视觉信号的产生和传导中具有重要作用,其主要通过大量摄取葡萄糖进行糖代谢以满足生理需求。而感光细胞凋亡,则是视网膜疾病导致患者盲的共同原因,该过程伴有氧化应激和合成代谢的改变。近期研究发现,糖代谢的重要分支——磷酸戊糖途径,在上述病理发展中起重要作用。其产物烟酰胺腺嘌呤二核苷酸磷酸(NADPH)作为感光细胞中重要的供氢体,参与物质合成代谢,对抗氧化应激,进而抑制感光细胞的凋亡。本文将从代谢活动和分子通路的角度,针对磷酸戊糖途径抑制感光细胞凋亡的作用机制进行综述,以期为临床科研工作提供参考。

滋阴明目方通过Akt/FoxO1/FasL通路抑制感光细胞凋亡治疗视网膜色素变性的机制研究

目的观察滋阴明目方对视网膜色素变性(retinitis pigmentosa,RP)小鼠视网膜组织中磷酸化蛋白激酶B(phosphorylated protein kinase B,p-Akt)、叉头框蛋白1(forkhead box transcription factor O1,FoxO1)以及凋亡相关因子配体(Fas ligand,FasL)表达的影响,探讨滋阴明目方抑制感光细胞凋亡的机制。方法将60只rd10小鼠随机分为模型组、滋阴明目方低剂量组[10 g/(kg·d)]、滋阴明目方中剂量组[20 g/(kg·d)]、滋阴明目方高剂量组[40 g/(kg·d)]、维生素A组[5 g/(kg·d)],每组12只;选取12只C57小鼠作为空白对照组(等量生理盐水),每组连续干预28 d。通过眼底照相观察小鼠眼底形态改变;进行视网膜电图检查并记录A波和B波振幅;HE染色观察病理形态学变化并测定外核层厚度;Western blot法检测小鼠视网膜组织p-Akt、FoxO1、FasL、半胱氨酸天冬氨酸特异性蛋白(cysteine aspartate-specific protease,Caspase)-3和Caspase-8蛋白表达。结果与空白对照组比较,模型组小鼠视盘苍白、变形,血管萎缩,视网膜电图的A波与B波振幅均降低(P<0.01),视网膜结构模糊,各层界限不清,感光细胞大量丧失,外核层明显变薄(P<0.01),视网膜组织中p-Akt蛋白表达水平明显降低(P<0.01),FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。与模型组比较,滋阴明目方中、高剂量组及维生素A组小鼠眼底血管较清晰,无视盘苍白表现;视网膜各层结构清晰,细胞排列相对整齐。与模型组、滋阴明目方低剂量组比较,滋阴明目方中、高剂量组的A波与B波振幅、视网膜外核层厚度均明显升高(P<0.01),维生素A组的B波振幅、视网膜外核层厚度明显升高(P<0.01);与滋阴明目方中剂量组比较,滋阴明目方高剂量组的A波与B波振幅、视网膜外核层厚度均明显升高(P<0.01),维生素A组的A波与B波振幅均明显降低(P<0.01);与滋阴明目方高剂量组比较,维生素A组的A波与B波振幅、视网膜外核层厚度均明显降低(P<0.01)。与模型组比较,滋阴明目方低、中、高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),FoxO1、FasL和Caspase-3蛋白表达水平降低(P<0.05,P<0.01),滋阴明目方中、高剂量组Caspase-8蛋白表达水平明显降低(P<0.01)。与滋阴明目方低剂量组比较,滋阴明目方高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),滋阴明目方中、高剂量组FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显降低(P<0.01)。与滋阴明目方中剂量组比较,滋阴明目方高剂量组和维生素A组p-Akt蛋白表达水平明显升高(P<0.01),滋阴明目方高剂量组FoxO1、Caspase-3和Caspase-8蛋白表达水平明显降低(P<0.01),维生素A组FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。与滋阴明目方高剂量组比较,维生素A组p-Akt蛋白表达水平明显降低(P<0.01),FoxO1、FasL、Caspase-3和Caspase-8蛋白表达水平明显升高(P<0.01)。结论滋阴明目方可能通过调控Akt/FoxO1/FasL通路,增强p-Akt表达,抑制FoxO1及下游基因FasL、Caspase-3和Caspase-8的蛋白表达,从而减少rd10小鼠视网膜细胞的凋亡,保护视网膜结构和功能,延缓RP的进展。

Retinitis pigmentosa and stem cell therapy

Retinitis pigmentosa(RP)is a group of genetic disorders characterized by progressive degeneration of photoreceptors and retinal pigment epithelium(RPE)cells.Its main clinical manifestations include night blindness and progressive loss of peripheral vision,making it a prevalent debilitating eye disease that significantly impacts patients’quality of life.RP exhibits significant phenotypic and genetic heterogeneity.For instance,numerous abnormal genes are implicated in RP,resulting in varying clinical presentations,disease progression rates,and pathological characteristics among different patients.Consequently,gene therapy for RP poses challenges due to these complexities.However,stem cells have garnered considerable attention in the field of RPE therapy since both RPE cells and photoreceptors can be derived from stem cells.In recent years,a large number of animal experiments and clinical trials based on stem cell transplantation attempts,especially cord blood mesenchymal stem cell(MSC)transplantation and bone marrow-derived MSC transplantation,have confirmed that stem cell therapy can effectively and safely improve the outer retinal function of the RP-affected eye.However,stem cell therapy also has certain limitations,such as the fact that RP patients may involve multiple types of retinal cytopathia,which brings great challenges to stem cell transplantation therapy,and further research is needed to solve various problems faced by this approach in the clinic.Through comprehensive analysis of the etiology and histopathological changes associated with RP,this study substantiates the efficacy and safety of stem cell therapy based on rigorous animal experimentation and clinical trials,while also highlighting the existing limitations that warrant further investigation.