Global trends in diabetic eye disease research from 2012 to 2021

Diabetic eye disease refers to a group of eye complications that occur in diabetic patients and include diabetic retinopathy, diabetic macular edema, diabetic cataracts, and diabetic glaucoma. However, the global epidemiology of these conditions has not been well characterized. In this study, we collected information on diabetic eye disease-related research grants from seven representative countries––the United States, China, Japan, the United Kingdom, Spain, Germany, and France––by searching for all global diabetic eye disease journal articles in the Web of Science and Pub Med databases, all global registered clinical trials in the Clinical Trials database, and new drugs approved by the United States, China, Japan, and EU agencies from 2012 to 2021. During this time period, diabetic retinopathy accounted for the vast majority(89.53%) of the 2288 government research grants that were funded to investigate diabetic eye disease, followed by diabetic macular edema(9.27%). The United States granted the most research funding for diabetic eye disease out of the seven countries assessed. The research objectives of grants focusing on diabetic retinopathy and diabetic macular edema differed by country. Additionally, the United States was dominant in terms of research output, publishing 17.53% of global papers about diabetic eye disease and receiving 22.58% of total citations. The United States and the United Kingdom led international collaborations in research into diabetic eye disease. Of the 415 clinical trials that we identified, diabetic macular edema was the major disease that was targeted for drug development(58.19%). Approximately half of the trials(49.13%) pertained to angiogenesis. However, few drugs were approved for ophthalmic(40 out of 1830;2.19%) and diabetic eye disease(3 out of 1830;0.02%) applications. Our findings show that basic and translational research related to diabetic eye disease in the past decade has not been highly active, and has yielded few new treatment methods and newly approved drugs.

Gut microbiota induced abnormal amino acids and their correlation with diabetic retinopathy

AIM:To explore the correlation of gut microbiota and the metabolites with the progression of diabetic retinopathy(DR)and provide a novel strategy to elucidate the pathological mechanism of DR.METHODS:The fecal samples from 32 type 2 diabetes patients with proliferative retinopathy(PDR),23 with nonproliferative retinopathy(NPDR),27 without retinopathy(DM),and 29 from the sex-,age-and BMI-matched healthy controls(29 HC)were analyzed by 16S rDNA gene sequencing.Sixty fecal samples from PDR,DM,and HC groups were assayed by untargeted metabolomics.Fecal metabolites were measured using liquid chromatographymass spectrometry(LC-MS)analysis.Associations between gut microbiota and fecal metabolites were analyzed.RESULTS:A cluster of 2 microbiome and 12 metabolites accompanied with the severity of DR,and the close correlation of the disease progression with PDR-related microbiome and metabolites were found.To be specific,the structure of gut microbiota differed in four groups.Diversity and richness of gut microbiota were significantly lower in PDR and NPDR groups,than those in DM and HC groups.A cluster of microbiome enriched in PDR group,including Pseudomonas,Ruminococcaceae-UCG-002,Ruminococcaceae-UCG-005,Christensenellaceae-R-7,was observed.Functional analysis showed that the glucose and nicotinate degradations were significantly higher in PDR group than those in HC group.Arginine,serine,ornithine,and arachidonic acid were significantly enriched in PDR group,while proline was enriched in HC group.Functional analysis illustrated that arginine biosynthesis,lysine degradation,histidine catabolism,central carbon catabolism in cancer,D-arginine and D-ornithine catabolism were elevated in PDR group.Correlation analysis revealed that Ruminococcaceae-UCG-002 and Christensenellaceae-R-7 were positively associated with L-arginine,ornithine levels in fecal samples.CONCLUSION:This study elaborates the different microbiota structure in the gut from four groups.The relative abundance of Ruminococcaceae-UCG-002 and Parabacteroides are associated with the severity of DR.Amino acid and fatty acid catabolism is especially disordered in PDR group.This may help provide a novel diagnostic parameter for DR,especially PDR.

Different approaches for treating myopic choroidal neovascularization:a network Meta-analysis

AIM:To evaluate the efficacy of intravitreal injection of anti-vascular endothelial growth factor(anti-VEGF),photodynamic therapy(PDT),and laser treatment(LT)for anatomical and functional improvement in myopic choroidal neovascularization(mCNV)patients.METHODS:Two researchers independently searched PubMed,Cochrane Library,Web of Science,and other databases to screen studies comparing best-corrected vision acuity(BCVA)and foveal center thickness(FCT)changes after mCNV treatment.Post-treatment chorioretinal atrophy(CRA)is a secondary outcome indicator.The retrieval time limit is from the database construction to January 30,2023.RESULTS:A total of 1072 eyes in 16 articles were included.In the RCTs,intravitreal bevacizumab(IVB)and intravitreal ranibizumab(IVR)were superior to PDT(MD=0.18,95%CI:0.02,0.40,MD=0.18,95%CI:0.01,0.42)in improving BCVA of mCNV patients(P<0.05).The relative effectiveness in improving BCVA,from high to low,appeared to be IVR,intravitreal aflibercept(IVA),IVB,LT,PDT,and sham first followed by IVA(Sham/IVA).While improving the FCT from high to low was IVA,IVR,IVB,PDT.In retrospective studies,the results of BCVA after long-term treatment showed that all the therapeutic effects from high to low was IVA,intravitreal conbercept(IVC),IVR,IVB,IVB/IVR,PDT with IVB/IVR,PDT.The effect of improving FCT was IVA,IVR,IVC,PDT,and IVB from high to low.And in the effects of improving CRA,the IVB appeared to be higher than IVR,while the PDT was the smallest,but none of the differences in the results were statistically significant.CONCLUSION:Anti-VEGF has the best effect on longterm vision improvement in mCNV patients,using IVB or IVR alone to treat mCNV may be better than IVB or IVR combined with PDT.There is no significant difference in the improvement of visual acuity,macular edema,and CRA in mCNV patients treated with any different anti-VEGF drugs.

Recent advances in RNA-targeting therapy for neurological diseases

Advances in sequencing and molecular technology now allow us to understand the genetic underpinnings of complex diseases such as neurological disorders.Genetic variations(or mutations) in the DNA sequence of single genes have been implicated in neurological diseases such as Huntington's disease and spinal muscular atrophy.As a result,the development of gene therapies for neurological diseases is now a feasible endeavor.

Differentiation of retinal ganglion cells from induced pluripotent stem cells: a review

Glaucoma is a common optic neuropathy that is characterized by the progressive degeneration of axons and the loss of retinal ganglion cells(RGCs). Glaucoma is one of the leading causes of irreversible blindness worldwide. Current glaucoma treatments only slow the progression of RGCs loss. Induced pluripotent stem cells(iPSCs) are capable of differentiating into all three germ layer cell lineages. iPSCs can be patient-specific,making iPSC-derived RGCs a promising candidate for cell replacement. In this review, we focus on discussing the detailed approaches used to differentiate iPSCs into RGCs.

Lycium barbarum polysaccharide-glycoprotein preventative treatment ameliorates aversive stimuli-induced depression

Previous studies have shown that Lycium barbarum polysaccharide,the main active component of Lycium barbarum,exhibits antiinflammatory and antioxidant effects in treating neurological diseases.However,the therapeutic action of Lycium barbarum polysaccharide on depression has not been studied.In this investigation,we established mouse models of depression using aversive stimuli including exposure to fox urine,air puff and foot shock and physical restraint.Concurrently,we administered 5 mg/kg per day Lycium barbarum polysaccharide-glycoprotein to each mouse intragastrically for the 28 days.Our results showed that long-term exposure to aversive stimuli significantly enhanced depressive-like behavior evaluated by the sucrose preference test and the forced swimming test and increased anxietylike behaviors evaluated using the open field test.In addition,aversive stimuli-induced depressed mice exhibited aberrant neuronal activity in the lateral habenula.Importantly,concurrent Lycium barbarum polysaccharide-glycoprotein treatment significantly reduced these changes.These findings suggest that Lycium barbarum polysaccharide-glycoprotein is a potential preventative intervention for depression and may act by preventing aberrant neuronal activity and microglial activation in the lateral habenula.The study was approved by the Jinan University Institutional Animal Care and Use Committee(approval No.20170301003)on March 1,2017.

Lutein delays photoreceptor degeneration in a mouse model of retinitis pigmentosa

Retinitis pigmentosa is a retinal disease characterized by photoreceptor degeneration.There is currently no effective treatment for retinitis pigmentosa.Although a mixture of lutein and other antioxidant agents has shown promising effects in protecting the retina from degeneration,the role of lutein alone remains unclear.In this study,we administered intragastric lutein to Pde6brd10 model mice,which display degeneration of retinal photoreceptors,on postnatal days 17(P17)to P25,when rod apoptosis reaches peak.Lutein at the optimal protective dose of 200 mg/kg promoted the survival of photoreceptors compared with vehicle control.Lutein increased rhodopsin expression in rod cells and opsin expression in cone cells,in line with an increased survival rate of photoreceptors.Functionally,lutein improved visual behavior,visual acuity,and retinal electroretinogram responses in Pde6brd10 mice.Mechanistically,lutein reduced the expression of glial fibrillary acidic protein in Müller glial cells.The results of this study confirm the ability of lutein to postpone photoreceptor degeneration by reducing reactive gliosis of Müller cells in the retina and exerting anti-inflammatory effects.This study was approved by the Laboratory Animal Ethics Committee of Jinan University(approval No.LACUC-20181217-02)on December 17,2018.

Characteristics of neural growth and cryopreservation of the dorsal root ganglion using three-dimensional collagen hydrogel culture versus conventional culture

In vertebrates, most somatosensory pathways begin with the activation of dorsal root ganglion(DRG) neurons. The development of an appropriate DRG culture method is a prerequisite for establishing in vitro peripheral nerve disease models and for screening therapeutic drugs. In this study, we compared the changes in morphology, molecular biology, and transcriptomics of chicken embryo DRG cultured on tissue culture plates(T-DRG) versus three-dimensional collagen hydrogels(C-DRG). Our results showed that after 7 days of culture, the transcriptomics of T-DRG and C-DRG were quite different. The upregulated genes in C-DRG were mainly related to neurogenesis, axon guidance, and synaptic plasticity, whereas the downregulated genes in C-DRG were mainly related to cell proliferation and cell division. In addition, the genes related to cycles/pathways such as the synaptic vesicle cycle, cyclic adenosine monophosphate signaling pathway, and calcium signaling pathway were activated, while those related to cell-cycle pathways were downregulated. Furthermore, neurogenesis-and myelination-related genes were highly expressed in C-DRG, while epithelial–mesenchymal transition-, apoptosis-, and cell division-related genes were suppressed. Morphological results indicated that the numbers of branches, junctions, and end-point voxels per C-DRG were significantly greater than those per T-DRG. Furthermore, cells were scattered in T-DRG and more concentrated in C-DRG, with a higher ratio of 5-ethynyl-2′-deoxyuridine(EdU)-positive cells in T-DRG compared with C-DRG. C-DRG also had higher S100 calcium-binding protein B(S100 B) and lower α-smooth muscle actin(α-SMA) expression than T-DRG, and contained fewer terminal deoxynucleotidyl transferase dUTP nick end labeling(TUNEL)-positive cells after 48 hours of serum starvation. After cryopreservation, C-DRG maintained more intact morphological characteristics, and had higher viability and less TUNEL-positive cells than T-DRG. Furthermore, newly formed nerve bundles were able to grow along the existing Schwann cells in C-DRG. These results suggest that C-DRG may be a promising in vitro culture model, with better nerve growth and anti-apoptotic ability, quiescent Schwann cells, and higher viability. Results from this study provide a reference for the construction, storage, and transportation of tissue-engineered nerves. The study was approved by the Ethics Committee of Aier School of Ophthalmology, Central South University, China(approval No. 2020-IRB16), on March 15, 2020.

Chinese ophthalmic school education:present and future

The Zhongshan Ophthalmic Center(ZOC),established by Professor Yaozhen Chen(Eugene Chan)and Professor Wenshu Mao(Winifred Mao)in October 1965,has enjoyed worldwide fame due the good performance and professional skills of the faculty.The past 55 years have witnessed huge successes for the ZOC from one generation to another,including individuals such as Prof.Shaozhen Li,Prof.Jiaqi Chen,Prof.Jian Ge,Prof.Minbin Yu and Prof.Yizhi Liu,etc.The Center was the first 3-A-Class ophthalmic hospital in China,the only State Key Laboratory for Ophthalmology in China and was ranked first for nine consecutive years in the ophthalmology category for the Specialized Department List for Chinese Hospitals.At present,it has become a“Whampoa military academy”training center for Chinese ophthalmologists,and numerous ophthalmologists are proud of being born in“ZOC”.