Patient-derived induced pluripotent stem cells with a MERTK mutation exhibit cell junction abnormalities and aberrant cellular differentiation potential

BACKGROUND Human induced pluripotent stem cell(hiPSC)technology is a valuable tool for generating patient-specific stem cells,facilitating disease modeling,and invest-igating disease mechanisms.However,iPSCs carrying specific mutations may limit their clinical applications due to certain inherent characteristics.AIM To investigate the impact of MERTK mutations on hiPSCs and determine whether hiPSC-derived extracellular vesicles(EVs)influence anomalous cell junction and differentiation potential.METHODS We employed a non-integrating reprogramming technique to generate peripheral blood-derived hiPSCs with and hiPSCs without a MERTK mutation.Chromo-somal karyotype analysis,flow cytometry,and immunofluorescent staining were utilized for hiPSC identification.Transcriptomics and proteomics were employed to elucidate the expression patterns associated with cell junction abnormalities and cellular differentiation potential.Additionally,EVs were isolated from the supernatant,and their RNA and protein cargos were examined to investigate the involvement of hiPSC-derived EVs in stem cell junction and differentiation.RESULTS The generated hiPSCs,both with and without a MERTK mutation,exhibited normal karyotype and expressed pluripotency markers;however,hiPSCs with a MERTK mutation demonstrated anomalous adhesion capability and differentiation potential,as confirmed by transcriptomic and proteomic profiling.Furthermore,hiPSC-derived EVs were involved in various biological processes,including cell junction and differentiation.CONCLUSION HiPSCs with a MERTK mutation displayed altered junction characteristics and aberrant differentiation potential.Furthermore,hiPSC-derived EVs played a regulatory role in various biological processes,including cell junction and differentiation.

空气填充联合内界膜翻转治疗伴有后巩膜葡萄肿的高度近视黄斑裂孔性视网膜脱离

目的:评估空气填充联合内界膜翻转及自体血治疗伴有后巩膜葡萄肿的高度近视黄斑裂孔性视网膜脱离(MHRD)的疗效。方法:回顾性非对照研究分析高度近视眼MHRD患者的治疗效果。玻璃体切割术中使用曲安奈德染色清除玻璃体后皮质,内界膜翻转后应用自体血固定翻转的内界膜后空气填充。记录术后黄斑裂孔闭合率、视网膜复位率及术后最佳矫正视力(BCVA)。结果:研究共纳入高度近视MHRD患者24例24眼。患者随访至少6mo,平均13.58±7.00mo。末次随访时21眼(88%)黄斑裂孔闭合,20眼(83%)视网膜复位。其中17眼(71%)黄斑裂孔闭合且视网膜复位,3眼(13%)黄斑裂孔未闭合但视网膜复位,4眼(17%)黄斑裂孔闭合但仍有视网膜下液。所有病例无需接受二次玻璃体切割手术。末次随访BCVA(LogMAR)较术前显著提高(0.65±0.34 vs 1.36±0.49,P<0.001)。12眼(50%)的BCVA提高大于等于2行。结论:玻璃体切割术联合内界膜翻转、自体血及空气填充是治疗高度近视眼MHRD的有效方法。

R102W mutation in the RS1 gene responsible for retinoschisis and recurrent glaucoma

AIM: To identify the mutations in RS1 gene associated with typical phenotype of X-linked juvenile retinoschisis(XLRS) and a rare condition of concomitant glaucoma. ·METHODS: Complete ophthalmic examinations were performed in the proband. The coding regions of the RS1 gene that encode retinoschisin were amplified by polymerase chain reaction and directly sequenced. ·RESULTS: The proband showed a typical phenotype of XLRS with large peripheral retinal schisis in both eyes,involving the macula and combined with foveal cystic change,reducing visual acuity. A typical phenotype of recurrent glaucoma with high intraocular pressure(IOP) and reduced visual field was also demonstrated with the patient. Mutation analysis of RS1 gene revealed R102W(c.304C】T) mutations in the affected male,and his mother was proved to be a carrier with the causative mutation and another synonymous polymorphism(c.576C】CT). ·CONCLUSION: We identified the genetic variations of a Chinese family with typical phenotype of XLRS and glaucoma. The severe XLRS phenotypes associated with R102W mutations reveal that the mutation determines a notable alteration in the function of the retinoschisin protein. Identification of the disease-causing mutation is beneficial for future clinical references.

Timp1 Deletion Induces Anxiety-like Behavior in Mice

The hippocampus is essential for learning and memory,but it also plays an important role in regulating emotional behavior,as hippocampal excitability and plasticity affect anxiety and fear.Brain synaptic plasticity may be regulated by tissue inhibitor of matrix metalloproteinase 1(TIMP1),a known protein inhibitor of extracellular matrix(ECM),and the expression of TIMP1 in the hippocampus can be induced by neuronal excitation and various stimuli.However,the involvement of Timp1 in fear learning,anxiety,and hippocampal synaptic function remains to be established.Our study of Timp1 function in vivo revealed that Timp1 knockout mice exhibit anxiety-like behavior but normal fear learning.Electrophysiological results suggested that Timp1 knockout mice showed hyperactivity in the ventral CA1 region,but the basic synaptic transmission and plasticity were normal in the Schaffer collateral pathway.Taken together,our results suggest that deletion of Timp1 in vivo leads to the occurrence of anxiety behaviors,but that Timp1 is not crucial for fear learning.

Turning point of organoid transplantation:first-in-human trial of iPSC-derived retinal organoid grafting in patients with retinitis pigmentosa

The discovery of induced pluripotent stem cells(iPSCs)has revolutionized the field of disease research,providing a promising platform for studying various conditions.Over the last decade,significant progress has been made in combining iPSCs with other cutting-edge technologies to investigate disease mechanisms and develop potential treatments.

A rational consideration of the genomic instability of human-induced pluripotent stem cells for clinical applications

Induced pluripotent stem cells (i PSCs) have gained popularity in regenerative medicine because of their ability to replicate and differentiate into multiple cell types, which has provided researchers with a powerful tool for modeling diseases and exploring treatments for human disorders. As i PSCs are obtained from the patient’s cells and possess the same potential as embryonic stem cells (ESCs).

Functional microglia derived from human pluripotent stem cells empower retinal organs

Microglia are known to play essential roles in the development,progression and treatment of diverse neurodegenerative diseases in the central nervous system,including the retina,brain and spinal cord.Recently,brain-induced microglia-like cells(iMGs)have been generated from human pluripotent stem cells(hPSCs);however,retinal microglia have yet to be developed in vitro.In this study,by mimicking in vivo microglial development,we established a simplified approach to differentiate hPSCs into high purity(>90%)iMGs.The iMGs express microglia-specific markers,release cytokines upon stimulation,and are capable of phagocytizing bacteria.When co-cultured with three-dimensional human retinal organoids(hROs),iMGs migrated into the hROs,tended to differentiate into resident retinal microglia,and simultaneously induced apoptosis in some neural cells.Notably,the resident i MGs in the hROs formed sparse web-like structures beneath the photoreceptor cell layer,resembling microglia's orientation in human retina.In conclusion,we developed a simplified and efficient method to generate microglia from human pluripotent stem cells,and we report the first derivation of retinaresident microglia in vitro,providing a new source of human retinal microglia for developmental and disease studies and regenerative therapeutics.

New loci for refractive errors and ocular biometric parameters in young Chinese Han adults

Myopia has become a major public health issue with an increasing prevalence.There are still individuals who experience similar environmental risk factors and,yet,remain non-myopic.Thus,there might be genetic factors protecting people from myopia.Considering the opposite ocular characteristics of primary angle closure glaucoma(PACG)to myopia and possible common pathway between them,we propose that certain risk genes for PACG might act as a protective factor for myopia.In this study,2,678 young adults were genotyped for 37 targeted single nucleotide polymorphisms.Compared with emmetropia,rs1401999(allele C:OR=0.795,P=0.03;genotype in dominant model:OR=0.759,P=0.02)and rs1258267(allele A:OR=0.824,P=0.03;genotype in dominant model:OR=0.603,P=0.01)were associated with low to moderate myopia and high myopia,respectively.Genotype under recessive model of rs11024102 was correlated with myopia(OR=1.456,P=0.01),low to moderate myopia(OR=1.443,P=0.02)and high myopia(OR=1.453,P=0.02).However,these associations did not survive Bonferroni correction.Moreover,rs1401999,rs1258267,and rs11024102 showed associations with certain ocular biometric parameters in different groups.Our study suggests that ABCC5,CHAT and PLEKHA7 might be associated with refractive errors by contributing to the regulation of ocular biometry,in terms of uncorrected results and their biological functions.

Retinal organoids as models for development and diseases

The evolution of pluripotent stem cell-derived retinal organoids(ROs)has brought remarkable opportunities for developmental studies while also presenting new therapeutic avenues for retinal diseases.With a clear understanding of how well these models mimic native retinas,such preclinical models may be crucial tools that are widely used for the more efficient translation of studies into novel treatment strategies for retinal diseases.Genetic modifications or patient-derived ROs can allow these models to simulate the physical microenvironments of the actual disease process.However,we are currently at the beginning of the three-dimensional(3D)RO era,and a general quantitative technology for analyzing ROs derived from numerous differentiation protocols is still missing.Continued efforts to improve the efficiency and stability of differentiation,as well as understanding the disparity between the artificial retina and the native retina and advancing the current treatment strategies,will be essential in ensuring that these scientific advances can benefit patients with retinal disease.Herein,we briefly discuss RO differentiation protocols,the current applications of RO as a disease model and the treatments for retinal diseases by using RO modeling,to have a clear view of the role of current ROs in retinal development and diseases.

Nonhuman Primate Model of Oculocutaneous Albinismwith TYR and OCA2 Mutations

Human visual acuity is anatomically determined by the retinal fovea.The ontogenetic development of the fovea can be seriously hindered by oculocutaneous albinism(OCA),which is characterized by a disorder of melanin synthesis.Although people of all ethnic backgrounds can be affected,no efficient treatments for OCA have been developed thus far,due partly to the lack of effective animal models.Rhesus macaques are genetically homologous to humans and,most importantly,exhibit structures of the macula and fovea that are similar to those of humans;thus,rhesus macaques present special advantages in the modeling and study of human macular and foveal diseases.In this study,we identified rhesus macaque models with clinical characteristics consistent with those of OCA patients according to observations of ocular behavior,fundus examination,and optical coherence tomography.Genomic sequencing revealed a biallelic p.L312I mutation in TYR and a homozygous p.S788L mutation in OCA2,both of which were further confirmed to affect melanin biosynthesis via in vitro assays.These rhesus macaque models of OCA will be useful animal resources for studying foveal development and for preclinical trials of new therapies for OCA.