Despite the clinical utility of bevacizumab in advanced colorectal cancer, resistance remains a major challenge. In this study, we unveiled a lactate-mediated mechanism driving vasculogenic mimicry (VM) and bevacizumab resistance through PKM2 lactylation. PKM2 lactylation at K206 by AARS1 promoted PKM2 nuclear translocation and interaction with FOSL1. PKM2 binding facilitated FOSL1-dependent super-enhancer formation and target gene transcription, which contributed to colorectal cancer cell VM. Genetic or pharmacologic inhibition of PKM2 lactylation disrupted VM and synergized with bevacizumab in patient-derived preclinical models, significantly improving therapeutic efficacy. Together, this study reveals lactylation as a metabolic switch linking cancer glycolytic reprogramming to transcriptional rewiring and proposes targeting PKM2 lactylation to enhance the antitumor activity of bevacizumab in colorectal cancer. SIGNIFICANCE:PKM2 lactylation mediates vasculogenic mimicry by facilitating FOSL1-dependent super-enhancer formation and represents a potential target to improve the clinical efficacy of bevacizumab in colorectal cancer patients.
Purpose:To evaluate the predictive accuracy of eight traditional and contemporary intraocular lens (IOL) power calculation formulas in Chinese cataract patients with prior radial keratotomy (RK). Patients and Methods:RK patients who underwent phacoemulsification with IOL implantation were retrospectively recruited. Refractive prediction errors (RPE)were calculated for eight formulas: Haigis-L, Shammas, Barrett True-K, Camellin Calossi Camellin (CCC), Kane, EVO, Pearl-DGS, and Jin-AI. The study compared RPE, mean absolute error (MAE), median absolute error (MedAE), and percentages of eyes achieving prediction errors within ±0.25, ±0.50, ±0.75, ±1.0, and ±2.0 diopters. Results:This retrospective study analyzed 34 eyes from 21 patients with prior RK surgery. The superior performing IOL power calculation formulas were Jin-AI (MAE = 0.64 D, MedAE = 0.49 D), Barrett True-K (MAE = 0.58 D, MedAE = 0.535 D), and EVO (MAE=0.59 D, MedAE = 0.538 D). These three formulas demonstrated comparable accuracy, with 47.1%, 44.1%, and 44.1% of eyes achieving prediction errors within ±0.50 D, respectively. The Haigis-L and Pearl-DGS formulas exhibited significantly higher prediction errors in eyes with more than 12 RK incisions. Conclusion:The Jin-AI, Barrett True-K, and EVO formulas demonstrated superior accuracy for IOL power calculation in Chinese cataract patients with prior RK. The Jin-AI formula, a novel artificial intelligence-based formula derived from Chinese individuals, presents a promising option for post-RK IOL calculation, while external validation studies across diverse ethnic groups are essential.
Glutamate (Glu) accumulation-induced excitotoxicity is a major cause of retinal ganglion cell (RGC) death in glaucoma, and the role of ferroptosis, a novel form of cell death, is critical in this process. The aim of this study was to investigate the function and regulatory mechanisms of the lipid transport protein StarD7 in RGC ferroptosis. An N-methyl-D-aspartate (NMDA)-induced retinal excitotoxicity mouse model and a Glu-induced RGC cell model were constructed for experimental investigation. RT‒qPCR and Western blotting were used to assess the expression of related genes and proteins, HE staining was used to assess pathological retinal damage, and kits were used to evaluate ferroptosis-related indicators. Ferroptosis was involved in NMDA-induced RGC damage in glaucoma mice. StarD7 expression was upregulated in glaucoma, and overexpression of StarD7 decreased the levels of total iron, Fe2+, ROS, and MDA in vitro and in vivo while increasing the expression levels of GSH, GPX4, and xCT, thereby suppressing RGC ferroptosis. Mechanistically, Glu treatment significantly reduced the expression of the Wnt signaling pathway proteins Wnt1 and β-catenin. Activating the Wnt/β-catenin pathway promoted StarD7 expression, which in turn inhibited Glu-induced ferroptosis in mRGCs. The Wnt/β-catenin signaling pathway inhibits Glu-induced RGC ferroptosis by upregulating StarD7 expression, revealing the potential neuroprotective role of StarD7 in glaucoma treatment and providing a scientific basis for the development of new therapeutic strategies. Not applicable.
In retinopathy of prematurity (ROP), preventing avascular dysplasia may be more critical than inhibiting abnormal neovascularization. While hypoxia-inducible factors (HIFs) are implicated in angiogenesis, their role in preventing ROP remains unclear. Oxygen-induced retinopathy (OIR) model and hyperoxic cell model were used in this study. Immunofluorescence, western blot, ELISA, cell counting kit-8 (CCK-8), and flow cytometry were applied to assess the effects of hyperoxia on the astrocytes. Co-culture of astrocytes with retinal microvascular endothelial cells (RMECs) was used to observe the effects of astrocyte inactivation on the RMECs. Overexpression of HIFs in astrocytes was used to investigate the mechanism. The OIR model revealed a decreased number of retinal astrocytes and the expression of dystrophin and R-cadherin in hyperoxic environments (P12), which was reversed after room air rearing (P17-P21), with an upward trend in RMECs (P21). In vitro hyperoxia induced significant apoptosis in astrocytes at 24 h. Moreover, the expression of angiogenesis-related factors (VEGF and ANGPTL4), vascular stabilization, and development-related factors (Laminin-β2, Dystrophin, R-cadherin) was decreased. Co-culture of astrocytes and RMECs yielded similar conclusions, with astrocyte inactivation decreasing the tube-forming capacity of RMECs. Overexpression of HIFs in astrocytes promoted the expression of VEGF, ANGPTL4, and Laminin-β2 under hyperoxic conditions. Emphatically, HIF-1α was more effective than HIF-2α in promoting the expression of integrin β1, dystrophin, and R-cadherin. Overexpression of HIFs in astrocytes reverses hyperoxia-induced retinal astrocyte inactivation and retinal vascular structural disruption and dysplasia. Strikingly, HIF-1α is a more suitable therapeutic target for ROP prevention than HIF-2α.
Gyrate atrophy (GACR), a rare autosomal recessive chorioretinal dystrophy caused by OAT mutations, is genetically and clinically underexplored in multi-ethnic Chinese populations. Eight patients from five families all exhibited high myopia (mean − 8.28 D), early-onset vision loss, and elevated plasma ornithine. Parapapillary atrophy (PPA) was common (76.92
Mitochondrial dysfunction, induced by prolonged hyperglycemia, is widely regarded as a central factor in oxidative stress and retinal ganglion cell (RGC) degeneration in diabetic retinopathy (DR). DJ-1 (PARK7) acts as a crucial antioxidant defense mechanism, stabilizing mitochondrial structure and redox balance. However, its expression is dramatically suppressed under diabetic conditions, and the upstream regulatory mechanisms remain incompletely characterized. Growing evidence from epigenetic research implicates microRNAs (miRNAs) as important players in the molecular pathways underlying DR progression. Among these, miRNA-122-5p has drawn increasing attention due to its aberrant activity under diabetic stress and its putative interaction with PARK7. In this study, we employed a streptozotocin-induced type 1 diabetes mouse model and glucose-stimulated R28 cells to explore the contribution of miRNA-122-5p to mitochondrial damage, oxidative stress, and RGC injury. In diabetic mice, we observed significant oxidative imbalance, increased apoptotic activity, RGC loss, and diminished retinal function. MiRNA profiling identified miRNA-122-5p as the most upregulated among candidate miRNAs. Inhibition of miRNA-122-5p attenuated these pathological changes and preserved both cellular integrity and visual function. In vitro, high glucose triggered mitochondrial fragmentation, membrane potential collapse, and excessive reactive oxygen species generation in R28 cells. Suppressing miRNA-122-5p alleviated these injuries. Dual-luciferase assays confirmed that miRNA-122-5p directly targets PARK7, thereby post-transcriptionally repressing DJ-1 expression and compromising mitochondrial resilience. These findings establish miRNA-122-5p as a critical upstream regulator of DJ-1-mediated antioxidant defense. By aggravating mitochondrial oxidative stress, it contributes to RGC vulnerability in DR. Targeted modulation of miRNA-122-5p may offer a novel therapeutic approach to preserve retinal neurons and counteract neurodegeneration in DR.
PurposeTo investigate the role of the lamina cribrosa (LC) astrocytes in the autoregulatory capacity of optic nerve head (ONH) vessels and to explore the underlying molecular mechanisms.MethodsThe Oxygen-glucose deprivation/reperfusion model (OGD/R) in vitro was constructed to examine the changes in cell morphology and protein expression in LC astrocytes. LC astrocytes were co-cultured with vascular smooth muscle cells (VSMCs) to detect the role of LC astrocytes in the autoregulatory function of vessels.ResultsThe partial pressure of oxygen (PO2) in the supernatant of LC astrocytes was significantly lower following OGD, and this reduction was more pronounced with longer OGD durations. OGD inhibited proliferation and promoted apoptosis in LC astrocytes, with longer OGD durations correlating with decreased proliferation and increased apoptosis. Reoxygenation following 1 h of OGD led to upregulation of GFAP, mTOR, cPLA2 protein expression and supernatant PGE2 concentration in LC astrocytes, an effect that can be attenuated by the mTOR inhibitor. Co-culturing with LC astrocyte resulted in increased expression of MYPT1 protein in VSMCs, and the VSMCs exhibited a relaxed morphology.ConclusionUnder in vitro OGD/R conditions, LC astrocyte were activated through the mTOR pathway, leading to increased secretion of PGE2, which locally regulates the dilation of VSMCs. In conclusion, LC astrocytes may regulate local blood flow in the ONH.
Glaucoma is a degenerative disease characterized by retinal ganglion cell (RGC) death and visual impairment caused by elevated intraocular pressure (IOP). Elevated IOP can activate microglia, which participate in ganglion cell injury. Based on the study of caveolin-1 (Cav-1) in glaucoma, we aimed to explore the effect and mechanism of Cav-1 on RGC apoptosis in mice with acute ocular hypertension (AOH). AOH mice were established, and Cav-1 was intravitreally injected. Retinal microglia and RGCs were isolated from neonatal mice. TUNEL staining, hematoxylin-eosin staining, immunohistochemistry, flow cytometry, PCR and western blotting were used to observe the effect of Cav-1 on RGCs and mouse retinas. The thickness of the whole retina and the inner retinal sublayer decreased significantly, retinal cell apoptosis increased after AOH injury, and Cav-1 treatment reversed the effect of AOH injury. In addition, Cav-1 treatment promoted the conversion of proinflammatory M1 microglia to anti-inflammatory M2 microglia. Microglia and RGCs were isolated from neonatal mice. Cav-1 protects RGCs from OGD/R-induced injury by changing the polarization status of retinal microglia in vitro. Further studies revealed that Cav-1 activated the Akt/PTEN signaling pathway and inhibited TLR4. Our study provides evidence that Cav-1 may be a promising therapeutic target for glaucoma.
Retinal ischemic disease is a major type of retinal diseases causing vision loss. Identifying the molecular mechanisms mediating the retinal ischemia-reperfusion (RIR) is the key to targeted intervention. In this study, we performed RNA-seq analysis of the retinal tissues of a retinal ischemia-reperfusion model of Sprague-Dawley (SD) rats, followed by differential gene expression analysis, gene ontology (GO) enrichment analysis, and protein-protein interaction (PPI) analysis. After studying we found that: The major biological processes affected after RIR was the regulation of vascular development. PPI analysis unveiled a regulatory module in which Platelet Derived Growth Factor Receptor Beta (PDGFRB) was upregulated. In the RIR cell model of human retinal microvascular endothelial cells (HRCEC) induced by oxygen-glucose deprivation/reperfusion (OGD/R), silencing PDGFRB at least partially rescued the detrimental effect on cell proliferation and in vitro angiogenic ability. In the rat model of RIR, the administration of PDGFR inhibitor alleviated the damages in the retinal microvascular system. Besides, we further demonstrated the protective effect of procyanidin against RIR induced damages in both the cell and animal model by dampening the overexpression of PDGFRB. Together, our data indicate that the upregulation of PDGFRB contributes to RIR-induced damages in retinal microvascular system, which provides a targetable strategy for therapeutic intervention.
目的 探索磁性微珠前房注射诱导高眼压模型的可行性及特点,OCT在模型评估中的作用.方法 将C57BL/6小鼠分为正常组、对照组与实验组.实验组前房内注射磁性微珠诱导高眼压,对照组前房内注射等量生理盐水,正常组不做任何处理.术前及术后第1天开始隔天检测眼压波动;建模3周后行荧光金逆行标记,建模4周后使用OCT检测两组小鼠视盘旁神经纤维厚度,并行视网膜行铺片计数各组RGCs数量.结果 小鼠前房内注射磁性荧光微珠后,微珠可均匀分布于房角处堵塞房角.实验组小鼠眼压自注射术后1 d开始升高,平均眼压为(19.37±4.38)mmHg,3周开始眼压下降;荧光金逆行标记RGCs,建立微珠诱导小鼠高眼压模型后4周,行OCT检测RNFL厚度.实验组RNFL厚度为(27.67±6.15)μm,较对照组明显变薄,两组比较差异有统计学意义(P=0.0082).检测OCT后收集眼球计数RGCs,实验组RGCs为(203.83±26.35)个,与对照组比较明显减少,差异有统计学意义(P=0.0094).结论 小鼠前房注射磁性微珠可以诱导持续稳定的眼压升高并引起明显RGC数量减少,可通过OCT无创、快速、重复的检测神经纤维层厚度发现RGC损伤.
目的 建立急性高眼压(acute ocular hypertension,AOH)小鼠模型,探索视网膜中窖蛋白(Caveolin,Cav)-1表达变化,明确其是否参与青光眼视网膜损伤的病理生理过程.方法 C57小鼠75只,60只纳入实验组,15只纳入对照组.对照组不做任何处理,实验组随机选取一眼建立AOH小鼠模型.分别于造模后1d、2d、3d、7d取眼球或视网膜通过荧光定量PCR(Q-PCR)、Western blot、免疫荧光检测Cav-1 mRNA和蛋白表达变化,并与对照组比较.结果 Q-PCR检测结果显示,实验组小鼠造模后1 d、2 d、3 d、7 d时视网膜中Cav-1 mRNA表达均升高,与对照组比较差异均有统计学意义(均为P<0.05),其中造模后2 d表达最高.Western blot检测结果显示,Cav-1蛋白在造模后2 d、3 d、7 d的实验组小鼠视网膜中表达均升高,与对照组比较差异均有统计学意义(均为P<0.05),其中造模后3d表达最高.免疫荧光检测结果显示,Cav-1在造模后1d、2d、3d、7d均可检测到高荧光表达.结论 Cav-1参与了AOH的病理过程,并且其表达变化在早期较明显.
Abstract Increasing evidence has shown that microRNAs (miRNAs) play an important role in the pathogenesis of diabetic retinopathy (DR). However, the role and mechanism of miRNA in regulating high glucose (HG)-induced ARPE-19 cell injury are still not well understood. The present study aimed to investigate the effects of miR-200a-3p on DR progression and reveal the underlying mechanisms of their effects. In the present study, we observed that miR-200a-3p was significantly decreased, while transforming growth factor-β2 (TGF-β2) expression was up-regulated in ARPE-19 cells treated with HG and retina tissues of DR rats. Subsequently, overexpression of miR-200a-3p significantly promoted cell proliferation, reduced apoptosis, as well as inhibited the levels of inflammatory cytokines secreted, matrix metalloprotease 2/9 (MMP2/9), and vascular endothelial growth factor (VEGF) in HG-injured ARPE-19 cells. Moreover, miR-200a-3p was proved to target TGF-β2 mRNA by binding to its 3′ untranslated region (3′UTR) using a luciferase reporter assay. Mechanistically, overexpression of miR-200a-3p reduced HG-induced ARPE-19 cell injury and reduced inflammatory cytokines secreted, as well as down-regulated the expression of VEGF via inactivation of the TGF-β2/Smad pathway in vitro. In vivo experiments, up-regulation of miR-200a-3p ameliorated retinal neovascularization and inflammation of DR rats. In conclusion, our findings demonstrated that miR-200a-3p-elevated prevented DR progression by blocking the TGF-β2/Smad pathway, providing a new therapeutic biomarker for DR treatment in the clinic.
Multifocal choroiditis (MFC) is multi-inflammatory lesions that occur in the retinal pigment epithelium (RPE) and the choriocapillaris. Optical examinations are the major diagnostic methods to diagnose the disease. To examine patients with different types of MFC by multiple imageological methods. To summarize the imageology features of different types of MFC to make a medical examination guideline for clinician practices. All of the patients who included in the study received examinations of fundus color photography, infrared fundus photography, fundus auto fluorescence (FAF), fluorescein fundus angiography (FFA), and optical coherence tomography (OCT), respectively. Finally, imageology features of different types of multifocal choroiditis were summarized. A total of 51 eyes from 28 patients with diagnosed MFC were included in the study. These patients consisted of 10 males and 18 females aged from 31 to 49 (mean age: 41.5 ± 0.8). 23 patients had MFC on both eye whilst 5 had monocular disease. The MFC lesions were classified as active inflammatory lesions, inactive inflammatory lesions, inflammatory lesions secondary active choroidal neovascularization (CNV) and inflammatory lesions secondary inactive CNV according to literature reports and comprehensive fundus imaging examinations. Examinations via fundus color photography, infrared fundus photography, FAF, FFA and OCT indicate typical imageological signals of different types of MFC. These imageology tests can greatly assist the clinicians to identify the MFC and provide proper therapies.
Objective To study the structural changes of retinal microcirculation in mouse model of ischemia reperfusion injury(RIR).Methods Ninty healthy male C57BL/6 mice were devided into normal group and RIR group by using random number table method,45 mice for each group.The left eyes in both groups were used in this study.The mouse model of RIR was established by perfusion of saline solution in the anterior chamber.The damage of microcirculation was analyzed from different levels of vascular structure and function by retinal blood vessel staining,FITC angiography,histopathological examination,and ultrostructure of retinal vessels was observed with transmission electron microscope.The experimental animals and experimental conditions complied with the Regulations on the Management of Laboratory Animals of Kunming Medical University.Results There was no significant difference in retinal arterioles diameter in the RIR group compared to the normal control group (P=0.350).The small veins were obviously dilated in comparison with normal control group (P =0.03) and were in hyper-congestive state.The artery/vein value was 0.76±0.03 in the RIR group,and that in the normal control group was 0.97±0.01,with significant difference between them (P=0.000).The main changes were capillary occlusion,non-perfusion zone formation and other structural changes,accompaning by blood-retinal barrier damage;the destruction of capillary endothelial cells and pericytes and basement membrane thickening were seen under the transmission electron microscope.Conclusions RIR mainly results in capillary damage,including capillary barrier damage,capillary occlusion and non-perfusion area formation.
Recent study has showed that Ginsenoside Rg1, the mian active compound of Panax ginseng, could ameliorate oxidative stress and myocardial apoptosis in diabetes mellitus. However, the roles and mechanisms of Rg1 in proliferative diabetic retinopathy (PDR) are still unclear. In the present study, we aimed to investigate the effects of Rg1 on mesenchymal activation of high-glucose (HG) cultured müller cells. High glucose conditions up-regulate MMP-2, MMP-9 and down-regulate TIMP-2, and promote mesenchymal activation in Müller cells. And Rg1 inhibits the HG-induced mesenchymal activation and HG-increased MMP-2 and MMP-9 and HG-decreased TIMP-2 in Müller cells. HG up-regulates Zeb1 and lncRNA RP11-982M15.8, and down-regulates miR-2113, and Rg1 inhibits these effects of HG. Both inhibition of miR-2113 and over-expression of RP11-982M15.8 significantly restored the HG induced mesenchymal activasion. Taken together, our findings suggested that Rg1 inhibited HG-induced mesenchymal activation and fibrosis via regulating miR-2113/RP11-982M15.8/Zeb1 pathway.
Caveolin-1 (Cav1) is the principle structural protein of caveolae.It plays important roles in the vascular system under both physiological and pathological conditions.Although Cav1 has been shown to inhibit microvascular permeability and has been considered as a tumor-suppressor for years, the underlying cellular mechanism has yet to be discovered.Here, we systematically investigated Cav1 functions in the main types of vascular cells, including endothelial cells (ECs), pericytes (PCs) and smooth muscle cells (SMCs).We synthesized a cell-permeable peptide called cavtratin that is derived from the Cav1 scaffolding domain.We found that cavtratin inhibited ECs in all assays, including survival, proliferation, migration and permeability assays.It also inhibited the proliferation of PCs and SMCs but had no effect on their survival or migration.The inhibitory effect of cavtratin on the proliferation of all vascular cells suggests that Cav1 plays important roles in vascular development and angiogenesis.Under physiological condition, the main function of Cav1 is to inhibit EC permeability.
Glaucoma, a group of eye diseases, causes gradual loss of retinal ganglion cells (RGCs) and ultimately results in irreversible blindness. Studies of the underlying mechanisms of glaucoma and clinical trial are far from satisfactory. Results from a genome-wide association study have suggested that the CAV1/CAV2 locus is associated with glaucoma, but this association and its potential underlying mechanisms need to be confirmed and further explored. Here, we studied the function of caveolin-1 (Cav1) in an acute ocular hypertension glaucoma model. Cav1 deficiency caused an aggregated lesion in the retina. In addition, treatment with cavtratin, a membrane permeable Cav1 scaffolding domain peptide, enhanced RGC survival. After cavtratin treatment, microglial numbers decreased significantly, and the majority of them migrated from the inner retinal layer to the outer retinal layers. Furthermore, cavtratin promoted a change in the microglia phenotype from the neurotoxic pro-inflammatory M1 to the neuroprotective anti-inflammatory M2. In a molecular mechanism experiment, we found that cavtratin activated the phosphorylation of both AKT and PTEN in cultured N9 cells. Our data highlights the neuroprotective effect of Cav1 on acute ocular hypertension and suggests that Cav1 may serve as a novel therapeutic target for the treatment of glaucoma. We further propose that cavtratin is a therapeutic candidate for glaucoma clinical trials.