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.

Non-linear relationship between age and subfoveal choroidal thickness in Chinese patients with proliferative diabetic retinopathy

BACKGROUND No study has investigated the change regularity between age and subfoveal choroidal thickness(SFCT)in proliferative diabetic retinopathy(PDR).AIM To investigate the relationship between the SFCT and age in Chinese patients with PDR.METHODS This was a cross-sectional retrospective study.The participants were hospitalized individuals with type 2 diabetes who underwent vitrectomy for PDR.Contralateral eyes that met the criteria were included in the study.All necessary laboratory tests were performed at the time of admission.Central macular thickness(CMT)and SFCT were two quantitative assessments made using enhanced depth imaging optical coherence tomography.CMT was measured automatically and SFCT was measured manually with digital calipers provided by the Heidelberg Eye Explorer software.RESULTS The final analysis included a total of 234 individuals with PDR.The average age was 55.60 years old±10.03 years old,and 57.69%of the population was male.Univariate analysis revealed a significant negative connection between age and SFCT in patients with PDR[β=-2.44,95%confidence interval(95%CI):-3.46 to-1.42;P<0.0001].In the fully adjusted model,the correlation between SFCT and age remained steady(β=-1.68,95%CI:-2.97 to-0.39;P=0.0117).Spline smoothing showed that the relationship between SFCT and age in patients with PDR was non-linear,with an inflection point at 54 years of age.CONCLUSION Our findings suggest that age is a key determinant of choroidal thickness.The non-linear link between SFCT and age in PDR patients should be taken into account.

Proliferative vitreoretinopathy and its relationship with inflammatory serum biomarkers

AIM:To analyze if a relationship between levels ofinflammatory serum biomarkers and severity of primaryproliferative vitreoretinopathy(PVR)exists.METHODS:A retrospective case-control study.Thehealthy adult patients with rhegmatogenous retinaldetachment and primary PVR were included in the PVRgroup.For the control group,healthy adults who underwentcataract surgery were included.The grade of PVR wasclassified according to the Retinal Society TerminologyCommittee.Blood samples were obtained before surgery,and processed in MYTHIC 18.Measures of interest wereneutrophil-to-lymphocyte ratio(NLR),platelet-to-lymphocyteratio(PLR),and lymphocyte-to-monocyte ratio(LMR),thetime between the decrease in visual acuity and surgery,PVRgrade,type of surgery,final best corrected visual acuity,andrate of re-detachment.RESULTS:Totally 240 patients were included,120 ineach group,79(65.8%)and 56(46.7%)were male in thePVR and control group,respectively.PVR A had greaterlevels of monocytes(0.28±0.18 vs 0.12±0.32,P=0.002),neutrophils(4.59±1.51 vs 3.92±1.27,P=0.006),and LMR(9.32±4.42 vs 7.43±3.90,P=0.01).PVR B had a greatermonocyte count(0.30±0.13 vs 0.12±0.32,P=0.001),andPVR C demonstrated higher levels in monocytes(0.27±0.12vs 0.12±0.32,P=0.004),neutrophils(4.39±1.13 vs3.92±1.27,P=0.004),and LMR(9.63±3.24 vs 7.43±3.90,P=0.002)compared to control,respectively.An LMR cut-offvalue of 9.38 predicted PVR with a sensibility of 54.2%andspecificity of 77.5%and NLR cut-off of 1.70 predicted PVRwith a sensibility of 62%and specificity of 54.2%.CONCLUSION:Patients with primary PVR demonstrategreater neutrophil,monocyte,and LMR levels than thecontrol group.Cut-off values obtained from ratios could beuseful in a clinical setting when no posterior view of thefundus is possible due to media opacity.

Differential distribution of fibrovascular proliferative membranes in 25-gauge vitrectomy for proliferative diabetic retinopathy

AIM:To analyze the distribution of fibrovascular proliferative membranes(FVPMs)in proliferative diabetic retinopathy(PDR)patients that treated with pars plana vitrectomy(PPV),and to evaluate the outcomes separately.METHODS:This was a retrospective and cross-sectional study.Consecutive 25-gauge(25-G)PPV cases operated for PDR from May 2018 to April 2020.According to the FVPMs images outlined after operations,subjects were assigned into three groups:arcade type group,juxtapapillary type group,and central type group.All patients were followed up for over one year.General characteristics,operation-related variables,postoperative parameters and complications were recorded.RESULTS:Among 103 eyes recruited,the FVPMs distribution of nasotemporal and inferiosuperioral was significantly different(both P<0.01),with 95(92.23%)FVPMs located in the nasal quadrants,and 74(71.84%)in the inferior.The eyes with a central FVPM required the longest operation time,with silicon oil used in most patients,generally combined with tractional retinal detachment(RD)and rhegmatogenous RD,the worst postoperative bestcorrected visual acuity(BCVA)and the highest rates of recurrent RD(all P<0.05).FVPM type,age of onset diabetes mellitus,preoperative BCVA,and combined with tractional RD and rhegmatogenous RD were significantly associated with BCVA improvement(all P<0.05).Compared with the central type group,the arcade type group had higher rates of BCVA improvement.CONCLUSION:FVPMs are more commonly found in the nasal and inferior mid-peripheral retina in addition to the area of arcade vessels.Performing 25-G PPV for treating PDR eyes with central FVPM have relatively worse prognosis.

Proteomic study of vitreous in proliferative diabetic retinopathy patients after treatment with aflibercept:a quantitative analysis based on 4D label-free technique

AIM:To identify different metabolites,proteins and related pathways to elucidate the causes of proliferative diabetic retinopathy(PDR)and resistance to anti-vascular endothelial growth factor(VEGF)drugs,and to provide biomarkers for the diagnosis and treatment of PDR.METHODS:Vitreous specimens from patients with diabetic retinopathy were collected and analyzed by Liquid Chromatography-Mass Spectrometry(LC-MS/MS)analyses based on 4D label-free technology.Statistically differentially expressed proteins(DEPs),Gene Ontology(GO),Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway representation and protein interactions were analyzed.RESULTS:A total of 12 samples were analyzed.The proteomics results showed that a total of 58 proteins were identified as DEPs,of which 47 proteins were up-regulated and 11 proteins were down-regulated.We found that C1q and tumor necrosis factor related protein 5(C1QTNF5),Clusterin(CLU),tissue inhibitor of metal protease 1(TIMP1)and signal regulatory protein alpha(SIRPα)can all be specifically regulated after aflibercept treatment.GO functional analysis showed that some DEPs are related to changes in inflammatory regulatory pathways caused by PDR.In addition,protein-protein interaction(PPI)network evaluation revealed that TIMP1 plays a central role in neural regulation.In addition,CD47/SIRPαmay become a key target to resolve anti-VEGF drug resistance in PDR.CONCLUSION:Proteomic analysis is an approach of choice to explore the molecular mechanisms of PDR.Our data show that multiple proteins are differentially changed in PDR patients after intravitreal injection of aflibercept,among which C1QTNF5,CLU,TIMP1 and SIRPαmay become targets for future treatment of PDR and resolution of anti-VEGF resistance.

Effectiveness and safety of early lens extraction during par plana vitrectomy for proliferative diabetes retinopathy with mild cataract:a randomized clinical trial

●AIM:To evaluate the effectiveness and safety of early lens extraction during pars plana vitrectomy(PPV)for proliferative diabetic retinopathy(PDR)compared to those of PPV with subsequent cataract surgery.●METHODS:This multicenter randomized controlled trial was conducted in three Chinese hospitals on patients with PDR,aged>45y,with mild cataracts.The participants were randomly assigned to the combined(PPV combined with simultaneously cataract surgery,i.e.,phacovitrectomy)or subsequent(PPV with subsequent cataract surgery 6mo later)group and followed up for 12mo.The primary outcome was the change in best-corrected visual acuity(BCVA)from baseline to 6mo,and the secondary outcomes included complication rates and medical expenses.●RESULTS:In total,129 patients with PDR were recruited and equally randomized(66 and 63 in the combined and subsequent groups respectively).The change in BCVA in the combined group[mean,36.90 letters;95%confidence interval(CI),30.35–43.45]was significantly better(adjusted difference,16.43;95%CI,8.77–24.08;P<0.001)than in the subsequent group(mean,22.40 letters;95%CI,15.55–29.24)6mo after the PPV,with no significant difference between the two groups at 12mo.The overall surgical risk of two sequential surgeries was significantly higher than that of the combined surgery for neovascular glaucoma(17.65%vs 3.77%,P=0.005).No significant differences were found in the photocoagulation spots,surgical time,and economic expenses between two groups.In the subsequent group,the duration of work incapacity(22.54±9.11d)was significantly longer(P<0.001)than that of the combined group(12.44±6.48d).●CONCLUSION:PDR patients aged over 45y with mild cataract can also benefit from early lens extraction during PPV with gratifying effectiveness,safety and convenience,compared to sequential surgeries.

Study on crustal thickness and the prediction of prolific depressions:the Bohai Basin as an example

The deep crustal structure is closely related to oil and gas reserves.Predicting the oil and gas enrichment of depressions based on the Moho depth and crustal thickness is a promising research topic with significant implications for guiding exploration in petroliferous basins.In this study,seismic data were used as a constraint on the use of satellite gravity anomaly inversion to obtain the distribution of Moho depth and crustal thickness in the Bohai Basin.Stretching factors were calculated to analyze the differential distribution of deep crustal structural activity.Four indicators,including the minimum Moho depth,minimum crustal thickness,sum of Moho stretching factors,and sum of crustal stretching factors,were selected.Principal component analysis was applied to reduce the dimensionality of the multi-indicator system and obtain an oil and gas enrichment score for quantitative prediction of favorable prolific depressions.The deviation between the inverted Moho depth and seismic constraints was small;thus,the data effectively reflect the variations in the characteristics of each depression.The analysis revealed significant statistical features related to the minimum Moho depth/crustal thickness and the sum of Moho/crustal stretching factors associated with prolific depressions.Based on the oil and gas enrichment score,the depressions were classified into four categories related to their different deep crustal structural characteristics.Highly active ClassⅠ,ClassⅡ,and ClassⅢdepressions are predicted to be favorable prolific depressions.This study expands the research on quantitatively predicting favorable prolific depressions in the Bohai Basin using the deep crustal structure and can contribute to reducing production costs and improving exploration efficiency in future explorations.

Intravitreal conbercept injection with panretinal photocoagulation for high-risk proliferative diabetic retinopathy with vitreous hemorrhage

AIM:To assess the clinical efficacy and safety of combining panretinal photocoagulation(PRP)with intravitreal conbercept(IVC)injections for patients with high-risk proliferative diabetic retinopathy(HR-PDR)complicated by mild or moderate vitreous hemorrhage(VH),with or without diabetic macular edema(DME).METHODS:Patients diagnosed with VH with/without DME secondary to HR-PDR and received PRP combined with IVC injections were recruited in this retrospective study.Upon establishing the patient’s diagnosis,an initial IVC was performed,followed by prompt administration of PRP.In cases who significant bleeding persisted and impeded the laser operation,IVC was sustained before supplementing with PRP.Following the completion of PRP,patients were meticulously monitored for a minimum of six months.Laser therapy and IVC injections were judiciously adjusted based on fundus fluorescein angiography(FFA)results.Therapeutic effect and the incidence of adverse events were observed.RESULTS:Out of 42 patients(74 eyes),29 were male and 13 were female,with a mean age of 59.17±12.74y(33-84y).The diabetic history was between 1wk and 26y,and the interval between the onset of visual symptoms and diagnosis of HR-PDR was 1wk-1y.The affected eye received 2.59±1.87(1-10)IVC injections and underwent 5.5±1.02(4-8)sessions of PRP.Of these,68 eyes received PRP following 1 IVC injection,5 eyes after 2 IVC injections,and 1 eye after 3 IVC injections.Complete absorption of VH was observed in all 74 eyes 5-50wk after initial treatment,with resolution of DME in 51 eyes 3-48wk after initial treatment.A newly developed epiretinal membrane was noted in one eye.Visual acuity significantly improved in 25 eyes.No complications such as glaucoma,retinal detachment,or endophthalmitis were reported.CONCLUSION:The study suggests that the combination of PRP with IVC injections is an effective and safe modality for treating diabetic VH in patients with HR-PDR.

Changes in renal function and morphological variations of kidney diseases in rheumatoid arthritis patients

Objective:Rheumatoid nephropathy is one of the most severe extra-articular manifestations of rheumatoid arthritis(RA)associated with a very unfavorable prognosis.This study aimed to identify changes in renal function and morphological variations of kidney diseases in RA patients.Methods:The study enrolled patients(126 patients)between 18 and 55 years of age with a confirmed active RA of more than 12 months.Each patient underwent the following range of laboratory and instrumental research methods:general clinical analysis of blood and urine,performing urinalysis according to Nechiporenko method;determining daily proteinuria;determining the blood content of glucose,urea,creatinine,uric acid,total bilirubin,liver transaminase level,ionogram,lipidogram,and coagulogram;determining the blood content of rheumatoid factor,anti-streptolysin O,and C-reactive protein;and X-ray of the joints of hands and feet.Renal function was examined by estimating glomerular filtration rate,tubular reabsorption index,and renal functional reserve.For studying the morphological changes in the kidneys under ultrasound examination,renal biopsy was performed in 31 patients with RA with urinary syndrome(proteinuria more than 0.3 g per day and hematuria).Results:Nephropathy in RA is characterized by impaired renal function and manifested by an increased blood creatinine and a decrease in glomerular filtration rate and renal functional reserve.Among morphological variations of nephropathy at RA,mesangial proliferative glomerulonephritis prevails,accounting for 48.4%of patients.Other disorders include the secondary amyloidosis(29.0%of patients),tubulointerstitial nephritis(16.1%),membranous glomerulonephritis(3.2%),and focal-segmental glomerulosclerosis(3.2%).Conclusion:Kidney damage is a common systemic manifestation of RA with a long and active course,a major nephropathy trigger.

Vascular endothelial growth factor/connective tissue growth factor and proteomic analysis of aqueous humor after intravitreal conbercept for proliferative diabetes retinopathy

AIM:To investigate the role of connective tissue growth factor(CTGF)and vascular endothelial growth factor(VEGF)in the protein profile of the aqueous humor in patients with proliferative diabetic retinopathy(PDR)following intravitreal injection of conbercept.METHODS:This study included 72 PDR patients and 8 cataract patients as controls.PDR patients were divided into 3 groups according to the intervals of 3,5,and 7d between intravitreal conbercept(IVC,0.5 mg/0.05 mL)injection and pars plana vitrectomy(PPV)performed.Aqueous humor samples were collected before and after IVC and PPV for VEGF and CTGF levels detected with enzyme-linked immunosorbent assay(ELISA).The differential proteomics of 10 patients who underwent PPV surgery 5d after IVC and 8 normal controls was studied,Gene Ontology(GO)and Kyoto Encyclopedia of Genes and Genomes(KEGG)analysis were performed on the data,and the protein interaction network of 23 differential proteins was studied.RESULTS:Post-IVC,VEGF levels decreased and CTGF levels increased significantly in aqueous humor,with the CTGF/VEGF ratio rising significantly at all intervals.Liquid chromatography tandem mass spectrometry(LC-MS/MS)identified differentially expressed proteins between preand post-IVC samples.GO and KEGG analyses revealed involvement in immune response,stress response,complement and coagulation cascades,ferroptosis,and PPAR signaling pathways.PPI analysis highlighted key proteins like APOA1,C3,and transferrin(TF).ELISA assay confirmed the differential expression of proteins such as HBA1,SERPINA1,COL1A1,and ACTB,with significant changes in the IVC groups.CONCLUSION:The study demonstrates that IVC effectively reduces VEGF levels while increasing CTGF levels,thereby modifying the CTGF/VEGF ratio,and IVC significantly alters the protein profile in the aqueous humor of patients with PDR.Proteomic analysis reveals that these changes are associated with critical biological pathways and protein interactions involved in immune response,stress response,and cellular metabolism.

Intravitreal therapy for the management of diabetic retinopathy:A concise review

Diabetic retinopathy(DR)is a serious microvascular complication of diabetes mellitus and may result in irreversible visual loss.Laser treatment has been the gold standard treatment for diabetic macular edema and proliferative diabetic retinopathy for many years.Of late,intravitreal therapy has emerged as a cornerstone in the management of DR.Among the diverse pharmacotherapeutic options,anti-vascular endothelial growth factor agents have demonstrated remarkable efficacy by attenuating neovascularization and reducing macular edema,thus preserving visual acuity in DR patients.

青岛近海浒苔暴发期大型底栖动物群落的生态研究

利用2008年7月3日至25日在青岛附近海域浒苔[Enteromorpha prolifera(Muell.)J.Ag]暴发期间进行的大型底栖动物定量分析资料,研究了该海域大型底栖动物群落在物种组成、生物量和丰度以及物种多样性方面的动态变化,以了解浒苔暴发对大型底栖动物的生态学影响。结果表明,本项目调查共采集到大型底栖动物152种,其中优势类群是环节动物多毛类78种,占51.32%。在调查期间,底栖动物的物种数量、平均栖息密度和生物量及物种多样性指数均发生较大的变化,其中环节动物多毛类的变化尤其明显。ABC曲线分析也表明,胶州湾口附近取样站的底栖动物群落在当时已受到中等程度干扰,其他某些站位在某次调查中也显示出一种大型底栖动物群落倾向于受到中等程度干扰的状况。

2型糖尿病患者血清铁蛋白水平与糖尿病视网膜病变的关系研究

糖尿病视网膜病变（diabetic retinopathy,DR）是2型糖尿病（type 2diabetes mellitus,T2DM）中最常见的微血管并发症,是致盲的主要因素之一,然而DR发生的具体机制还不清楚,但通常认为与氧化应激反应和炎症反应有关。

Effects of Geldanamycin on Expression of Bcl-2 in Human Cervical Cancer HeLa Cells

OBJECTIVE Geldanamycin,a natural product of Streptomyces geldanus,binds the heat shock protein 90(Hsp90),a cell chaperone protein that interacts with Bcl-2.In this study,we investigated whether geldanamycin(GA)inhibits proliferation of HeLa cells through induction of apoptosis by decreasing the level of Bcl-2 expression. METHODS HeLa cells,a human cervical cell line,were cultured in vitro and treated with different concentrations of GA(0,0.02,0.2, 2,10μmol/L)for 24 h.or were treated for different lengths of time at a GA concentration of 10μmol/L.Proliferation of the cells was analyzed by an MTT assay,and cell apoptosis was determined by staining the cells with annexin V.In addition,cellular mRNA levels for Bcl-2 and Hsp90 were determined by the semiquantitative polymerase chain reaction(PCR),and the levels of Bcl-2 and Hsp90 protein expression were determined by Western blots. RESULTS Treatment of cells with GA was found to inhibit HeLa cell proliferation in a concentration and time-dependent manner.The inhibition was a result of increased cellular apoptotic levels.Further analyses showed that while the mRNA and protein expression levels of Hsp90 were not affected,GA treatment significantly reduced the level of Bcl-2 mRNA and protein expression in a concentration-dependent manner that correlated with the observed inhibition of cell proliferation. CONCLUSION GA can inhibit proliferation and increase apoptosis of HeLa cells by decreasing the transcription and expression of an anti-apoptotic gene bcl-2,probably through interaction and functional inhibition of Hsp90.

Long-chain acyl-CoA synthetase in fatty acid metabolism involved in liver and other diseases:An update

Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-Co As, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or lossof-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolismassociated effects of ACSLs in diseases.

Increased proliferation activity measured by immunoreactive Ki67 is associated with survival improvement in rectal/recto sigmoid cancer

AIM: To assess the expression of Ki67 as prognosticator in rectal/recto sigmoid cancer.METHODS: Samples from 146 patients with rectal and recto sigmoid cancer were studied for expression of Ki67 and its prognostic significance in comparison with clinicopathological predictors of survival. Formalin-fixed, paraffin-embedded tissues from 6 (4.1%) patients with T1, 26 (17.8%) with T2, 94 (64.4%) with T3, and 20 (13.7%) with T4 tumors were studied. Ki67 expression was determined immunohistochemically. Samples were divided according to mean value into high (＞40%) and low (≤40%) expression. Areas of extensive proliferation (＞50%) were defined as 'hot spot' areas. RESULTS: Hot spot areas were present in samples regardless of histopathological grade. Lower TNM and Dukes stage and higher expression of Ki67 and presence of Ki67 hot spot areas in histopathological samples were associated with better survival, whereas no association was observed with histopathological grade (P = 0.78). In Cox multivariate regression analysis, significant prognostic factors were Dukes stage (P＜0.001), presence of lymph node metastases (P = 0.015), age (P = 0.035) andpresence of Ki67 hot spot areas (P = 0.044). CONCLUSION: Proliferative activity as measured by Ki67 in rectal cancer is associated with survival improvement compared with patients with low Ki67. Areas of prognostically significant increased proliferation were found independently of histopathological tumor grade.

Prevalence of diabetic retinopathy, proliferative diabetic retinopathy and non-proliferative diabetic retinopathy in Asian T2DM patients: a systematic review and Metaanalysis

AIM: To investigate the pooled prevalence of diabetic retinopathy(DR), proliferative DR(PDR) and nonproliferative DR(NPDR) in Asian type 2 diabetes mellitus(T2 DM) patients. METHODS: We performed a systematic search online search using PubMed, EMBASE, Web of Science, the Cochrane Library, and China WeiPu Library to identify eligible studies that reported the prevalence of DR, PDR and NPDR in Asian T2 DM patients. Effect size(ES) with 95% confidence interval(CI) was used to evaluate the prevalence of DR, PDR and NPDR in Asian T2 DM patients, respectively. RESULTS: There were 41 references and 48 995 T2 DM patients involved in this study. The prevalence of DR, PDR, and NPDR was 28%, 6%, and 27% in T2 DM patients, respectively; while the prevalence of PDR and NPDR in DR patients was 17% and 83%, respectively. Subgroup analysis showed that prevalence of DR in T2 DM patients from Singaporean, Indian, South Korean, Malaysian, Asian, and Chinese was 33%, 42%, 16%, 35%, 21% and 25%, respectively. In T2 DM patients with NPDR from Indian, South Korean, Malaysian, Asian, Chinese, higher prevalence was found than that in PDR patients(45% vs 17%, 13% vs 3%, 30% vs 5%, 23% vs 2% and 22% vs 3%), as well as in DR patients(74% vs 26%, 81% vs 19%, 86% vs 14%, 92% vs 8% and 85% vs 15%). The prevalence of PDR in T2 DM from India was higher than patients fromother locations of Asia, and the same results were also observed in NPDR patients. CONCLUSION: In either T2 DM Asian patients or DR patients, NPDR is more common than PDR. Based on our results, we should pay more attention to NPDR screening and management in T2 DM patients, and we also recommend suitable interventions to prevent its progression.

Changes in vitreous VEGF, bFGF and fibrosis in proliferative diabetic retinopathy after intravitreal bevacizumab

AIMTo evaluate the relationship between intravitreal bevacizumab (IVB) treatment and the levels of vitreous vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and vitreous-retina surface fibrosis in patients with proliferative diabetic retinopathy (PDR).METHODSThis study was a prospective, open-label, controlled, randomized clinical trial. Sixty-eight eyes of PDR patients (n=53) and macular hole patients (n=15) were enrolled in this study. Thirty-four eyes of the PDR patients received IVB before vitrectomy. Twenty-three of the 34 PDR patients received IVB treatment 5d before vitrectomy (subgroup a), and 11 of the 34 PDR patients received IVB treatment greater than 2wk prior to vitrectomy (subgroup b). Nineteen of the PDR patients did not receive IVB treatment at any time prior to vitrectomy. The levels of bFGF and VEGF in vitreous samples were measured using enzyme-linked immunosorbent assay (ELISA) and the degree of vitreoretinal fibrosis was characterized using clinical data and data obtained intra-operatively.RESULTSIn PDR patients, VEGF and bFGF levels were significantly increased compared to non-PDR (control) subject's eyes (P&#x0003c;0.01). In PDR patients, vitreous VEGF levels were significantly decreased following IVB treatment compared to PDR patients that did not receive IVB treatment (P&#x0003c;0.01). The degree of vitreoretinal fibrosis was significantly increased in subgroup b compared to subgroup a(P&#x0003c;0.05) and to patients that did not receive IVB (P&#x0003c;0.05). Vitreous bFGF levels were significantly greater in subgroup b than subgroup a (P&#x0003c;0.01) or in patients who did not receive IVB treatment (P&#x0003c;0.05). A Spearman's rank correlation test indicated that higher levels of vitreous bFGF, but not VEGF, correlated with the degree of vitreoretinal fibrosis.CONCLUSIONWe found that bFGF levels increase in PDR patient's vitreous after IVB treatment longer than two weeks prior to vitrectomy and correlated with the degree of fibrosis after IVB treatment. These findings suggest vitreous fibrosis is increased in PDR patients after IVB treatment may be due to increased levels of bFGF.

Treatment of diabetic retinopathy: Recent advances and unresolved challenges

Diabetic retinopathy(DR) is the leading cause of blindness in industrialized countries. Remarkable advances in the diagnosis and treatment of DR have been made during the past 30 years, but several important management questions and treatment deficiencies remain unanswered. The global diabetes epidemic threatens to overwhelm resources and increase the incidence of blindness, necessitating the development of innovative programs to diagnose and treat patients. The introduction and rapid adoption of intravitreal pharmacologic agents, particularly drugs that block the actions of vascular endothelial growth factor(VEGF) and corticosteroids, have changed the goal of DR treatment from stabilization of vision to improvement. Anti-VEGF injections improve visual acuity in patients with diabetic macular edema(DME) from 8-12 letters and improvements with corticosteroids are only slightly less. Unfortunately, a third of patients have an incomplete response to anti-VEGF therapy, but the best second-line therapy remains unknown. Current first-line therapy requires monthly visits and injections; longer acting therapies are needed to free up healthcare resources and improve patient compliance. VEGF suppression may be as effective as panretinal photocoagulation(PRP) for proliferative diabetic retinopathy, but more studies are needed before PRP is abandoned. For over 30 years laser was the mainstay for the treatment of DME, but recent studies question its role in the pharmacologic era. Aggressive treatment improves vision in most patients, but many still do not achieve reading and driving vision. New drugs are needed to add to gains achieved with available therapies.

Inhibition of RhoA/Rho-kinase pathway suppresses the expression of extracellular matrix induced by CTGF or TGF-β in ARPE-19

AIM:To investigate the role of Rho-associated protein kinase (ROCK) inhibitor, Y27632, in mediating the production of extracellular matrix (ECM) components including fibronectin, matrix metallo-proteinase-2 (MMP-2) and type I collagen as induced by connective tissue growth factor(CTGF) or transforming growth factor-β (TGF-β) in a human retinal pigment epithelial cell line, ARPE-19. METHODS:The effect of Y27632 on the CTGF or TGF-β induced phenotype in ARPE-19 cells was measured with immunocytochemistry as the change in F-actin. ARPE-19 cells were treated with CTGF (1, 10, 100ng/mL)and TGF-β (10ng/mL) in serum free media, and analyzed for fibronectin, laminin, and MMP-2 and type I collagen by RT-qPCR and immunocytochemistry. Cells were also pretreated with an ROCK inhibitor, Y27632, to analyze the signaling contributing to ECM production. ·RESULTS:Treatment of ARPE-19 cells in culture with TGF-β or CTGF induced an ECM change from a cobblestone morphology to a more elongated swirl pattern indicating a mesenchymal phenotype. RT-qPCR analysis and different gene expression analysis demonstrated an upregulation in expression of genes associated with cytoskeletal structure and motility. CTGFor TGF-β significantly increased expression of fibronectin mRNA (P =0.006, P =0.003 respectively), laminin mRNA (P =0.006, P =0.005), MMP-2 mRNA (P =0.006, P =0.001), COL1A1 mRNA (P =0.001, P =0.001), COL1A2 mRNA (P = 0.001, P =0.001). Preincubation of ARPE-19 with Y27632 (10mmol/L) significantly prevented CTGF or TGF-β induced fibronectin (P=0.005, P=0.003 respectively), MMP-2 (P = 0.003, P =0.002), COL1A1 (P =0.006, P =0.003), and COL1A2 (P =0.006, P =0.004) gene expression, but not laminin (P =0.375, P =0.516). CONCLUSION:Our study demonstrated that both TGF-β and CTGF upregulate the expression of ECM components including fibronectin, laminin, MMP-2 and type I collagen by activating the RhoA/ROCK signaling pathway. During this process, ARPE-19 cells were shown to change from an epithelial to a mesenchymal phenotype in vitro. Y27632, a ROCK inhibitor, inhibited the transcription of fibronectin, MMP-2 and type I collagen, but not laminin. The data from our work suggest a role for CTGF as a profibrotic mediator. Inhibiting the RhoA/ROCK pathway represents a potential target to prevent the fibrosis of retinal pigment epithelial (RPE) cells. This might lead to a novel therapeutic approach to preventing the onset of early proliferative vitreoretinopathy(PVR).