Ginsenoside Rg_2(GRg2) is a triterpenoid compound found in Panax notoginseng. This study explored its effects and mechanisms on diabetic retinopathy and angiogenesis. The study employed endothelial cell models induced by glucose or vascular endothelial growth factor(VEGF), the chorioallantoic membrane(CAM) model, the oxygen-induced retinopathy(OIR) mouse model, and the db/db mouse model to evaluate the therapeutic effects of GRg2 on diabetic retinopathy and angiogenesis. Transwell assays and endothelial tube formation experiments were conducted to assess cell migration and tube formation, while vascular area measurements were applied to detect angiogenesis. The impact of GRg2 on the retinal structure and function of db/db mice was evaluated through retinal thickness and electroretinogram(ERG) analyses. The study investigated the mechanisms of GRg2 by analyzing the activation of Yes-associated protein(YAP) and Toll-like receptors(TLRs) pathways. The results indicated that GRg2 significantly reduced cell migration numbers and tube formation lengths in vitro. In the CAM model, GRg2 exhibited a dose-dependent decrease in the vascular area ratio. In the OIR model, GRg2 notably decreased the avascular and neovascular areas, ameliorating retinal structural disarray. In the db/db mouse model, GRg2 increased the total retinal thickness and enhanced the amplitudes of the a-wave, b-wave, and oscillatory potentials(OPs) in the ERG, improving retinal structural disarray. Transcriptomic analysis revealed that the TLR signaling pathway was significantly down-regulated following YAP knockdown, with PCR results consistent with the transcriptome sequencing findings. Concurrently, GRg2 downregulated the expression of Toll-like receptor 4(TLR4), TNF receptor-associated factor 6(TRAF6), and nuclear factor-kappaB(NF-κB) proteins in high-glucose-induced endothelial cells. Collectively, GRg2 inhibits cell migration and tube formation and significantly reduces angiogenesis in CAM and OIR models, improving retinal structure and function in db/db mice, with its pharmacological mechanism likely involving the down-regulation of YAP expression.
Animals ; Ginsenosides/pharmacology* ; Diabetic Retinopathy/physiopathology* ; Mice ; YAP-Signaling Proteins ; Humans ; Male ; Signal Transduction/drug effects* ; Cell Movement/drug effects* ; Adaptor Proteins, Signal Transducing/genetics* ; Mice, Inbred C57BL ; Neovascularization, Pathologic/metabolism* ; Drugs, Chinese Herbal/administration & dosage* ; Panax notoginseng/chemistry* ; Endothelial Cells/metabolism* ; Transcription Factors/genetics* ; Angiogenesis

OBJECTIVES: Long noncoding RNAs (lncRNA) play important roles in the pathological processes of angiogenesis-related diseases such as cancer and diabetic retinopathy. This study aims to identify global research trends and hotspots in the field of lncRNAs in angiogenesis-related diseases and to explore future research directions. METHODS: Relevant literature published between 2012 and 2022 was retrieved from the Web of Science Core Collection (WoSCC). A total of 1 516 articles on lncRNAs and angiogenesis-related diseases were included for bibliometric analysis. CiteSpace and VOSviewer were used to analyze publication countries, institutions, journals, authors, co-cited references, and key words. RESULTS: The number of publications in this field has shown a steadily increasing trend from 2012 to 2022, peaking in 2021. China has the highest number of publications, while the United States ranked highest in centrality. Nanjing Medical University was the most prolific institution. Liu Y was the most productive author, while Wang Y ranked first in co-citation frequency. Cell was the most frequently cited journal. The latest terms of burst key words were vascular remodeling, dysfunction, heart, target, suppress, and pulmonary arterial hypertension. CONCLUSIONS From 2012 to 2022, research on lncRNAs in angiogenesis-related diseases has grown significantly. China leads in publication volume, while the United States holds the most academic influence. Emerging research hotspots such as vascular remodeling and dysfunction point to key directions for future research.
Bibliometrics ; RNA, Long Noncoding/genetics* ; Humans ; Neovascularization, Pathologic/genetics* ; Neoplasms/genetics* ; Diabetic Retinopathy/genetics* ; Biomedical Research/trends* ; China ; Angiogenesis

Ginsenoside Rg_1, one of the main active components of precious traditional Chinese medicine Ginseng Radix et Rhizoma, has the anti-oxidative stress, anti-inflammation, anti-aging, neuroprotection, and other pharmacological effects. Diabetic retinopathy(DR), the most common complication of diabetes, is also the main cause of impaired vision and blindness in the middle-aged and the elderly. The latest research shows that ginsenoside Rg_1 can protect patients against DR, but the protection and the mechanism are rarely studied. This study mainly explored the protective effect of ginsenoside Rg_1 against DR in type 2 diabetic mice and the mechanism. High fat diet(HFD) and streptozotocin(STZ) were used to induce type 2 diabetes in mice, and hematoxylin-eosin(HE) staining was employed to observe pathological changes in the retina of mice. The immunohistochemistry was applied to study the localization and expression of nucleotide-binding oligomerization domain-like receptors 3(NLRP3) and vascular endothelial growth factor(VEGF) in retina, and Western blot was used to detect the expression of nuclear factor-kappa B(NF-κB), p-NF-κB, NLRP3, caspase-1, interleukin-1β(IL-1β), transient receptor potential channel protein 6(TRPC6), nuclear factor of activated T-cell 2(NFAT2), and VEGF in retina. The results showed that ginsenoside Rg_1 significantly alleviated the pathological injury of retina in type 2 diabetic mice. Immunohistochemistry results demonstrated that ginsenoside Rg_1 significantly decreased the expression of NLRP3 and VEGF in retinal ganglion cells, middle plexiform layer, and outer plexiform layer in type 2 diabetic mice. According to the Western blot results, ginsenoside Rg_1 significantly lowered the expression of p-NF-κB, NLRP3, caspase-1, IL-1β, TRPC6, NFAT2, and VEGF in retina of type 2 diabetic mice. These findings suggest that ginsenoside Rg_1 can significantly alleviate DR in type 2 diabetic mice, which may be related to inhibition of NLRP3 inflammasome and VEGF. This study provides experimental evidence for the clinical application of ginsenoside Rg_1 in the treatment of DR.
Aged ; Animals ; Diabetes Mellitus, Experimental/metabolism* ; Diabetes Mellitus, Type 2/genetics* ; Diabetic Retinopathy/genetics* ; Ginsenosides/pharmacology* ; Humans ; Inflammasomes/metabolism* ; Mice ; Middle Aged ; NF-kappa B/metabolism* ; NLR Family, Pyrin Domain-Containing 3 Protein/metabolism* ; Signal Transduction ; Vascular Endothelial Growth Factor A/genetics*

Objective To investigate the association between the methylenetetrahydrofolate reductase gene C677T (MTHFR C677T) polymorphism and diabetic retinopathy (DR). Methods A total of 6971 subjects including 2707 DR patients and 4264 controls from 23 studies were enrolled in the study. A random-effects model was applied to estimate the overall effects and the stratified effects of the MTHFR C677T polymorphism on the risk of DR, and study quality was also assessed. Results Strong associations were observed between the MTHFR C677T polymorphism and DR. The carries of MTHFR C677T were more likely to be found in the DR group in relative to the healthy control group with odds ratio 1.68, 2.55, and 2.31 respectively in allele contrast model (T vs. C, 95%CI: 1.29-2.18, P<0.001, I ²=78.4%), homozygous model (TT vs. CC, 95%CI: 1.70-3.83, P=0.008, I ²=54.4%) and dominant model (TT+CT vs. CC, 95%CI: 1.62-3.29, P<0.001, I ²=74.7%). This association can also be found in contrast to the Ncd (non-complicated diabetic mellitus) group (allele contrast, OR=1.50, 95%CI: 1.07-2.11, P=0.032, I ²=62.1%; homozygous, OR=2.39, 95%CI: 1.06-5.38, P=0.017, I ²=66.7%; dominant, OR=1.59, 95%CI: 0.97-2.62, P=0.056, I ²=56.5%). For the heterozygous model (CT vs. CC), the association was significant in contrast to the healthy control group (OR=1.46, 95%CI: 1.64-3.69, P=0, I ²=77.3%), while in contrast to the Ncd control group the association was not statistically meaningful (OR=1.38, 95%CI: 0.87-2.18, P=0.131, I ²=43.7%). For the recessive model, 1.92-fold increased risk was found only in contrast to the Ncd control group (95%CI: 1.07-3.43, P=0.064, I ²=55.0%). There was no significant association found in the models in contrast to the DM control group. Conclusion In this meta-analysis, we found an association between the MTHFR C677T polymorphism and DR, especially in contrast to the Ncd control group. Further studies are required to establish more definite relationship.
Alleles ; Diabetic Retinopathy/genetics* ; Female ; Gene Frequency ; Genetic Predisposition to Disease/genetics* ; Genotype ; Humans ; Male ; Methylenetetrahydrofolate Reductase (NADPH2)/genetics* ; Polymorphism, Single Nucleotide

Diabetes is a common metabolic disorder with a worldwide prevalence of 8.3% and is the leading cause of visual loss, end-stage renal disease and amputation. Recently, genome-wide association studies (GWASs) have identified genetic risk factors for diabetic microvascular complications of retinopathy, nephropathy, and neuropathy. We summarized the recent findings of GWASs on diabetic microvascular complications and highlighted the challenges and our opinion on future directives. Five GWASs were conducted on diabetic retinopathy, nine on nephropathy, and one on neuropathic pain. The majority of recent GWASs were underpowered and heterogeneous in terms of study design, inclusion criteria and phenotype definition. Therefore, few reached the genome-wide significance threshold and the findings were inconsistent across the studies. Recent GWASs provided novel information on genetic risk factors and the possible pathophysiology of diabetic microvascular complications. However, further collaborative efforts to standardize phenotype definition and increase sample size are necessary for successful genetic studies on diabetic microvascular complications.
Amputation ; Diabetic Retinopathy ; Genetics ; Genome-Wide Association Study* ; Kidney Failure, Chronic ; Neuralgia ; Phenotype ; Prevalence ; Risk Factors ; Sample Size

BACKGROUNDVascular endothelial growth factor (VEGF) is a major mediator of angiogenesis, and plays a key role in the pathogenesis of diabetic retinopathy (DR). This study was designed to identify the possible role of VEGF gene polymorphisms in the development of DR in type 2 diabetic patients in Chinese and clarify the relationship between VEGF serum levels and the risk of DR.

METHODSThis cross-sectional study included 1 040 Chinese subjects with type 2 diabetes mellitus. There were 372 patients diagnosed with DR in the case group and 668 patients without DR in the control group. DNA from each patient was analyzed for VEGF polymorphisms of -2578A/C (rs699947), -1154G/A (rs1570360), -460C/T (rs833061), +405C/G (rs2010963), and +936C/T (rs3025039) using MassARRAY compact analyzer. The VEGF serum levels were quantified by enzyme-linked immunosorbent assay (ELISA).

RESULTSNo evidence of association was observed between -2578 A/C (rs699947), +405C/G (rs2010963), +936C/T (rs3025039), and DR risk under stringent Bonferroni's correction. However, VEGF serum levels were significantly higher in DR patients than those of control group. The genetic variation of VEGF polymorphisms influenced VEGF serum levels; subjects carrying the VEGF -2578 C/C (rs699947) genotype had greater VEGF serum levels than those carrying the C/A genotype and VEGF serum levels were significantly higher in CC genotype of the +405C/G (rs2010963) compared with those of the other genotypes.

CONCLUSIONSThe data did not suggest significant association between the VEGF polymorphisms and DR risk under stringent Bonferroni's correction. However, our study indicated that DR patients have higher VEGF levels than diabetic patients without retinopathy, and -2578A/C (rs699947) and +405C/G (rs2010963) may be important factors in determining serum VEGF levels.

Aged ; Asian Continental Ancestry Group ; genetics ; Cross-Sectional Studies ; Diabetes Mellitus, Type 2 ; complications ; Diabetic Retinopathy ; blood ; genetics ; Female ; Humans ; Male ; Polymorphism, Genetic ; Vascular Endothelial Growth Factor A ; blood ; genetics

OBJECTIVETo identify the possible association between C(-106)T polymorphism of the aldose reductase (ALR) gene and diabetic retinopathy (DR) in a cohort of Chinese patients with type 2 diabetes mellitus (T2DM).

METHODSFrom November 2009 to September 2010, patients with T2DM were recruited and assigned to DR group or diabetic without retinopathy (DWR) group according to the duration of diabetes and the grading of 7-field fundus color photographs of both eyes. Genotypes of the C(-106)T polymorphism (rs759853) in ALR gene were analyzed using the MassARRAY genotyping system and an association study was performed.

RESULTSA total of 268 T2DM patients (129 in the DR group and 139 in the DWR group) were included in this study. No statistically significant differences were observed between the 2 groups in the age of diabetes onset (P=0.10) and gender (P=0.78). The success rate of genotyping for the study subjects was 99.6% (267/268), with one case of failure in the DR group. The frequencies of the T allele in the C(-106)T polymorphism were 16.0% (41/256) in the DR group and 19.4% (54/278) in the DWR group (P=0.36). There was no significant difference in the C(-106)T genotypes between the 2 groups (P=0.40). Compared with the wild-type genotype, odds ratio (OR) for the risk of DR was 0.7 (95% CI, 0.38-1.3) for the heterozygous CT genotype and 0.76 (95% CI, 0.18-3.25) for the homozygous TT genotype. The risk of DR was positively associated with microalbuminuria (OR=4.61; 95% CI, 2.34-9.05) and insulin therapy (OR=3.43; 95% CI, 1.94-6.09).

CONCLUSIONSMicroalbuminuria and insulin therapy are associated with the risk of DR in Chinese patients with T2DM. C(-106)T polymorphism of the ALR gene may not be significantly associated with DR in Chinese patients with T2DM.

Albuminuria ; epidemiology ; urine ; Aldehyde Reductase ; genetics ; Asian Continental Ancestry Group ; China ; Cohort Studies ; Diabetes Mellitus, Type 2 ; complications ; drug therapy ; ethnology ; genetics ; Diabetic Retinopathy ; drug therapy ; ethnology ; etiology ; genetics ; Female ; Gene Frequency ; Humans ; Hypoglycemic Agents ; administration & dosage ; adverse effects ; therapeutic use ; Insulin ; administration & dosage ; adverse effects ; therapeutic use ; Logistic Models ; Male ; Multivariate Analysis ; Polymorphism, Single Nucleotide ; Risk

BACKGROUNDDiabetes-related pathogenic factors can cause retinal ganglion cell (RGC) apoptosis, but the specific mechanism is not very clear. The aim of this study is to investigate the correlation between glycogen synthase kinase-3 (GSK-3) activation and retinal neuron apoptosis.

METHODSIn an in vitro experiment, the number of apoptotic RGC-5 cells differentiated by staurosporine was evaluated via flow cytometry and nuclei staining using Hoechst 33258. GSK-3 phosphorylation and caspase-3 activation in RGC-5 cells after serum deprivation were determined using Western blotting. Mitochondrial membrane potential was detected using the dye 5, 5', 6, 6'tetrachloro-1, 1', 3, 3'-tetrethyl benzimidalyl carbocyanine iodide, and reactive oxygen species (ROS) levels were measured with dihydroethidium. In an in vivo experiment, the number of apoptotic retinal neurons was evaluated via terminal transferase dUTP nick-end labeling (TUNEL), and GSK-3 phosphorylation was determined using Western blotting, in the retinal nerve epithelial tissue of rats in which diabetes was induced by intravenous tail-vein injection of streptozotocin for 4 weeks.

RESULTSThe levels of phosphorylated Ser21/9 in GSK-3α/β and p-T308/S473-AKT were lower and the cleaved caspase-3 levels were higher in the serum-deprived model (P < 0.05). Lithium chloride treatment was associated with a slower rate of apoptosis, increased mitochondrial membrane potential, and decreased ROS levels in differentiated RGC-5 cells (P < 0.05). The level of blood glucose and the number of TUNEL-positive cells in the whole-mounted retinas were higher (P < 0.01), and the levels of phosphorylated Ser21/9 in GSK-3α/β and body weight were lower (P < 0.05). However, the thickness of the retinal nerve epithelial layer was not significantly less in diabetic rats compared with control group. Lithium chloride intravitreal injection increased the levels of phosphorylated Ser21/9 in GSK-3α/β and decreased TUNEL-positive cells in the whole-mounted retinas.

CONCLUSIONGSK-3 kinase is closely related to retinal neuron apoptosis, and the application of the GSK-3 inhibitor lithium chloride can reduce retinal neuron apoptosis in early diabetic retinopathy.

Animals ; Apoptosis ; genetics ; physiology ; Cell Line ; Cell Survival ; physiology ; Diabetic Retinopathy ; enzymology ; genetics ; metabolism ; Flow Cytometry ; Glycogen Synthase Kinase 3 ; genetics ; metabolism ; Male ; Neurons ; cytology ; metabolism ; Rats ; Rats, Sprague-Dawley ; Retina ; cytology ; enzymology

PURPOSE: Monocyte chemoattractant protein-1 (MCP-1) is a chemokine that can increase adhesion molecule expression on monocytes and produce superoxide anions. Hyperglycemia induces MCP-1 production in vascular endothelial cells and retinal pigmented epithelial cells, and has been implicated as a causal factor in the facilitation of vascular complications in diabetes. In the present study, we evaluated the association of a single nucleotide polymorphism (SNP) in the MCP-1 gene with proliferative diabetic retinopathy (PDR) in a Korean population with type 2 diabetes. MATERIALS AND METHODS: We conducted a case-control study, which enrolled 590 subjects with type 2 diabetes, and SNP genotyping of c.2518A/G in the MCP-1 gene was performed using polymerase chain reaction followed by digestion with PvuII restriction enzyme. RESULTS: The prevalence of c.2518A/G polymorphism in diabetic patients was 13.2% (A/A), 47.1% (A/G) and 39.7% (G/G). In patients with diabetic retinopathy, the prevalence of PDR was significantly higher (p=0.009) in diabetic subjects with the c.2518A/A genotype (35.9%; n=78) compared to those with either the A/G or G/G genotype (22.3%, n=512). The prevalence of any other micro and macro-complications, including nephropathy and cerebrovascular events, were not different according to the c.2518A/G genotype. CONCLUSION: Our new genetic findings suggest that the c.2518A/A genotype in MCP-1 could be used as a susceptibility gene to predispose Koreans exhibiting type 2 diabetes for the development of PDR.
Aged ; Case-Control Studies ; Chemokine CCL2/*genetics ; Diabetes Mellitus, Type 2/*complications ; Diabetic Retinopathy/etiology/*genetics ; Female ; Genetic Association Studies ; Genetic Predisposition to Disease ; Genotype ; Humans ; Male ; Middle Aged ; *Polymorphism, Single Nucleotide ; Republic of Korea

BACKGROUNDPoly(ADP-ribose) polymerase (PARP) plays an important role in the death of retinal capillary cells in diabetic retinopathy (DR) partly via its regulation of nuclear factor kappa B (NF-κB). The current study investigated the effect of the regimen of Gaoshan Hongjingtian (RG) on the mechanism of PARP regulation of NF-κB, and demonstrated the possible impact of the RG and Gaoshan Hongjingtian (Rhodiola sachalinensis, RS) on diabetic retinopathy.

METHODSWistar rats were made diabetic by administering streptozotocin. They were then assigned to three groups at random. After 2 months, the three groups of these diabetic rats were treated with RS or RG, or untreated. Analyses of expression levels of PARP, NF-κB, and intercellular adhesion molecule-1 (ICAM-1) in the retinas of rats in different groups were performed by Western blotting and immunohistochemical assays, and mRNA levels of NF-κB and ICAM-1 were determined by real-time polymerase chain reaction (PCR). In addition, the basement membranes of capillaries in the rats' retinas were observed using electron microscopy, and diabetes-induced capillary degeneration (ghost pericytes and acellular capillaries) were quantitated.

RESULTSFrom the third month after the injection of streptozotocin, the diabetic rats were given daily RG, RS or tap water separately. The diabetic rats failed to gain weight compared with normal age-matched rats, whereas their glycated hemoglobin levels were significantly increased. After 5 months, the mRNA levels of NF-κB and ICAM-1 and the protein expression of PARP, NF-κB, and ICAM-1 were significantly increased in the retinas of diabetic rats in the untreated group compared with the nondiabetic controls. After 8 months, the number of degenerated retinal capillaries (ghost pericytes and acellular capillaries) was significantly increased in the diabetic rats in the untreated group compared with normal age-matched rats. RG and RS inhibited diabetes-induced over-expression of PARP, NF-κB, and ICAM-1 in the retinas of diabetic rats at the end of 5-month diabetic duration. Treatment using RG and RS significantly inhibited increases in the number of acellular capillaries and pericyte ghosts and suppressed the basement membrane thickening in the retinas of rats with diabetes for 8 months compared with the control diabetic rats.

CONCLUSIONSThese results indicate that PARP plays an important role in the pathogenesis of diabetic retinopathy. RS and RG may have acted on the mechanism of PARP regulation of NF-κB, which suppressed the expression of NF-κB and ICAM-1, and led to the inhibition of retinal capillary degeneration.

Animals ; Basement Membrane ; drug effects ; pathology ; Diabetes Mellitus, Experimental ; drug therapy ; pathology ; Diabetic Retinopathy ; drug therapy ; pathology ; Intercellular Adhesion Molecule-1 ; genetics ; Male ; Medicine, Chinese Traditional ; NF-kappa B ; genetics ; physiology ; Poly(ADP-ribose) Polymerases ; physiology ; Rats ; Rats, Wistar ; Rhodiola ; Streptozocin