Stanford Advisors


  • Yang Sun, Postdoctoral Faculty Sponsor

All Publications


  • Pathophysiology of intraoperative floppy iris syndrome: An unsettled debate. Survey of ophthalmology Shen, Y., Frauches, R., Zhao, J., Lo, C. H., Ning, K., Chen, S., Liu, Z., Zhang, F., Sun, Y. 2025

    Abstract

    Intraoperative floppy iris syndrome (IFIS)--characterized by iris blowing, prolapse, and progressive miosis during phacoemulsification surgery--poses significant challenges for eye surgeons. Despite being described almost 2 decades ago, its pathophysiology remains unclear. Initially, IFIS was thought to be a result of sympathetic signal blockage in the iris dilator muscle, since α-blockers such as tamsulosin were found to be a strong predisposing factor; however, many IFIS cases occur even in patients who discontinued α-blockers prior to cataract surgery. Several potential mechanisms through which α-blockers induces chronic changes in the iris - iris dilator atrophy, drug-melanin interaction, and loss of vascular tone - have been proposed as possible mechanisms. We address the prevailing theories on α-receptor-dependent mechanisms for IFIS and the current prophylactic measures undertaken to prevent IFIS-associated intraocular complications.

    View details for DOI 10.1016/j.survophthal.2025.06.002

    View details for PubMedID 40472999

  • SOX9 Induces Orbital Fibroblast Activation in Thyroid Eye Disease Via MAPK/ERK1/2 Pathway. Investigative ophthalmology & visual science Zhou, M., Lin, B., Wu, P., Ke, Y., Huang, S., Zhang, F., Hei, X., Mao, Z., Li, X., Wan, P., Chen, T., Yang, H., Huang, D. 2024; 65 (2): 25

    Abstract

    To evaluate the expression of sry-box transcription factor 9 (SOX9) in orbital fibroblasts (OFs) of thyroid eye disease (TED) and to find its potential role and underlying mechanism in orbital fibrosis.OFs were cultured from orbital connective tissues obtained from patients with TED (n = 10) and healthy controls (n = 6). SOX9 was depleted by small interfering RNA or overexpressed through lentivirus transduction in OFs. Fibroblast contractile activity was measured by collagen gel contraction assay and proliferation was examined by EdU assay. Transcriptomic changes were assessed by RNA sequencing.The mRNA and protein levels of SOX9 were significantly higher in OFs cultured from patients with TED than those from healthy controls. Extracellular matrix-related genes were down-regulated by SOX9 knockdown and up-regulated by SOX9 overexpression in TED-OFs. SOX9 knockdown significantly decrease the contraction and the antiapoptotic ability of OFs, whereas the overexpression of SOX9 increased the ability of transformation, migration, and proliferation of OFs. SOX9 knockdown suppressed the expression of phosphorylated ERK1/2, whereas its overexpression showed the opposite effect. Epidermal growth factor receptor (EGFR) is one of the notably down-regulated genes screened out by RNA sequencing. Chromatin immunoprecipitation-qPCR demonstrated SOX9 binding to the EGFR promoter.A high expression of SOX9 was found in TED-OFs. SOX9 can activate OFs via MAPK/ERK1/2 signaling pathway, which in turn promotes proliferation and differentiation of OFs. EGFR was a downstream target gene of SOX9. SOX9/EGFR can be considered as therapeutic targets for the treatment of orbital fibrosis in TED.

    View details for DOI 10.1167/iovs.65.2.25

    View details for PubMedID 38345552

    View details for PubMedCentralID PMC10866156

  • Lutein targeting orbital fibroblasts attenuates fibrotic and inflammatory effects in thyroid-associated ophthalmopathy. Experimental eye research Hei, X., Lin, B., Wu, P., Li, X., Mao, Z., Huang, S., Zhang, F., Zhou, M., Ke, Y., Yang, H., Huang, D. 2023; 232: 109515

    Abstract

    Lutein (LU) is a carotenoid that has recently been implicated in multiple roles in fibrosis, inflammation, and oxidative stress. Thyroid-associated ophthalmopathy (TAO) is particularly relevant to these pathological changes. We thus aim to probe the potential therapeutic effects of TAO in an in vitro model. We used LU pre-treating OFs derived from patients with TAO or not, then treated with TGF-β1(or IL-1β)to induce fibrosis (or inflammation). We analyzed the different expressions of related genes and proteins, and the molecular mechanism pathway on TAO OFs was screened by RNA sequencing, which is identified in vitro. We found that LU attenuates fibrotic and inflammatory effects in TAO. LU inhibited ACTA2, COL1A1, FN1, and CTGF mRNA expression and suppressed α-SMA, and FN1 protein expression induced by TGF-β1. Besides, LU suppressed OFs migration. Besides, it is shown that LU suppressed inflammation-related genes, such as IL-6, IL-8, CXCL1, and MCP-1. Moreover, LU inhibited oxidative stress induced by IL-1β, which is analyzed by DHE fluorescent probe staining. RNA sequencing suggested ERK/AP-1 pathway may be the molecular mechanism of LU protective effect on TAO, which is identified by RT-qPCR and western-blot. In summary, this study provides the first evidence that LU significantly attenuates the pathogenic manifestations of TAO by inhibiting the expression of fibrotic and inflammation-related genes and ROS produced by OFs. These data suggested that LU may be a potential medicine for TAO.

    View details for DOI 10.1016/j.exer.2023.109515

    View details for PubMedID 37207866

  • Melatonin Alleviates Retinal Ischemia-Reperfusion Injury by Inhibiting p53-Mediated Ferroptosis. Antioxidants (Basel, Switzerland) Zhang, F., Lin, B., Huang, S., Wu, P., Zhou, M., Zhao, J., Hei, X., Ke, Y., Zhang, Y., Huang, D. 2023; 12 (6)

    Abstract

    Retinal ischemia-reperfusion (RIR) injury caused by high intraocular pressure (IOP) is an important risk factor contributing to retinal ganglion cell (RGC) death, eventually causing blindness. A key progressive pathological process in the development of RIR is the death of RGCs. However, the detailed mechanisms underlying RGC death caused by RIR have not yet been clearly elucidated, and effective treatments are lacking. Ferroptosis is a recently defined form of programmed cell death that is closely related to organ injury. Melatonin (MT) is a promising neuroprotective agent, but its effects on RIR injury remain unclear. In this study, murine models of acute ocular hypertension and oxygen and glucose deprivation/reoxygenation (OGD/R) model were adopted to simulate retinal ischemia. MT alleviated retinal damage and RGC death in RIR mice, significantly attenuating RIR-induced ferroptosis. Furthermore, MT reduced the expression of p53, a master regulator of ferroptosis pathways, and the upregulation of p53 promoted ferroptosis and largely abolished the neuroprotective effects of MT. Mechanistically, the overexpression (OE) of p53 suppressed the expression of the solute carrier family 7 member 11 (Slc7a11), which was accompanied by increased 12-lipoxygenase (Alox12) expression, triggering retinal ferroptosis. Moreover, MT-ameliorated apoptosis, neuroinflammation and microglial activation were observed. In summary, MT conferred neuroprotection against RIR injury by inhibiting p53-mediated ferroptosis. These findings indicate that MT is a retina-specific ferroptosis inhibitor and a promising therapeutic agent for retinal neuroprotection.

    View details for DOI 10.3390/antiox12061173

    View details for PubMedID 37371903

    View details for PubMedCentralID PMC10295547

  • Intraorbital self-inflating hydrogel expander implantation with a modified technique in congenital microphthalmia. Journal of AAPOS : the official publication of the American Association for Pediatric Ophthalmology and Strabismus Wu, P., Lin, B., Sun, T., Li, X., Meng, J., Zhang, F., Huang, D. 2022; 26 (4): 193.e1-193.e7

    Abstract

    To investigate the long-term outcomes of intraorbital self-inflating hydrogel expander implantation with optic nerve transection in children with congenital microphthalmia.The medical records of unilaterally blind microphthalmic pediatric patients undergoing intraconal hydrogel expander implantation with optic nerve transection were reviewed retrospectively. For each patient, the microphthalmic eye was preserved. The orbital volume and globe volume were measured and analyzed based on computed tomography scans taken preoperatively and 36 months postoperatively. The palpebral length was measured between the medial and lateral canthus at every follow-up. Surgical complications were also recorded.Twelve patients were included (median age, 44.25 ± 17.5 months). At 36 months postoperatively, the microphthalmic and contralateral orbital volumes increased by 3.07 ± 0.77 ml and 2.03 ± 0.67 ml, respectively. The mean microphthalmic/contralateral ratio (MCR) of the orbital volume increased significantly from 76.60% ± 5.46% to 83.81% ± 5.41% (P < 0.001). The microphthalmic palpebral length increased by 6.17 ± 1.85 mm, whereas the contralateral palpebral length increased by 2.67 ± 1.44 mm. Significant changes were observed in the palpebral length MCR (68.00% ± 4.83% vs 85.07% ± 3.87%; P < 0.001). There was no significant change in the microphthalmic globe volume at 36 months postoperatively (P = 0.215). For the fellow eye, the globe volume increased significantly by 0.53 ± 0.34 ml (P < 0.001). During the follow-up period, 2 patients developed a sunken prosthesis. One patient had difficulty opening the eye after wearing the conformer. There were no cases of expander rejection or extrusion.In this small cohort of patients with congenital microphthalmia, intraorbital self-expanding hydrogel expander implantation with optic nerve transection led to excellent osseous and eyelid growth throughout the 36-month follow-up period.

    View details for DOI 10.1016/j.jaapos.2022.03.010

    View details for PubMedID 35835324

  • Melatonin exerts anti-angiogenic and anti-inflammatory effects in alkali-burned corneas. Annals of translational medicine Meng, J., Lin, B., Huang, S., Li, Y., Wu, P., Zhang, F., Ke, Y., Hei, X., Huang, D. 2022; 10 (8): 432

    Abstract

    Corneal neovascularization (CNV) caused by alkali burn injury is tightly associated with an inflammatory reaction and can lead to vision loss. Melatonin is involved in anti-inflammation and anti-angiogenesis, but its role in CNV has not yet been investigated.We induced CNV using sodium hydroxide (NaOH) and compared the reactions of vehicle control and melatonin-treated male C57BL/6 mice at 7 and 14 days following the corneal burn. The infiltration of inflammatory cells and the expression of proangiogenic factors, chemokines, and inflammation-related molecules were quantified via immunohistochemical (IHC) analysis and quantitative real-time reverse transcription-polymerase chain reaction (qRT-PCR), respectively. Murine peritoneal macrophages were used in vitro to further verify the effect of melatonin in inflammatory CNV.Compared with the vehicle control mice, the melatonin-treated mice showed significant inhibition of angiogenesis and reduction of corneal epithelial defects in alkali-burned corneas. Concomitantly, the infiltration of inflammatory cells and F4/80+ cells were dramatically reduced after melatonin treatment. The messenger RNA (mRNA) expression of proangiogenic factors [vascular endothelial growth factors (VEGF) and matrix metalloproteinase-9 (MMP-9)], monocyte chemotactic protein-1 (MCP-1), nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), and pro-inflammatory cytokines [tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) and IL-6] were down-regulated in the melatonin-treated mice. Moreover, melatonin inhibited the expression of these factors in murine peritoneal macrophages.Melatonin inhibits the neovascular and inflammatory responses in corneal alkali burn injury, suggesting that it may be a potential therapy for CNV.

    View details for DOI 10.21037/atm-21-4927

    View details for PubMedID 35571431

    View details for PubMedCentralID PMC9096387

  • IL-11 Is Elevated and Drives the Profibrotic Phenotype Transition of Orbital Fibroblasts in Thyroid-Associated Ophthalmopathy. Frontiers in endocrinology Wu, P., Lin, B., Huang, S., Meng, J., Zhang, F., Zhou, M., Hei, X., Ke, Y., Yang, H., Huang, D. 2022; 13: 846106

    Abstract

    Orbital fibrosis is a hallmark of tissue remodeling in thyroid-associated ophthalmopathy (TAO). Previous studies have shown that interleukin (IL)-11 plays a pivotal profibrotic role in various inflammatory and autoimmune diseases. However, the expression pattern of IL-11 in patients with TAO and whether IL-11 is mechanistically linked with pathological fibrosis remains unknown. In this study, we investigated IL-11 levels in the serum and orbital connective tissue of patients with TAO, and evaluated the correlation of these levels with the patient's clinical activity score. We also evaluated the expression pattern of IL-11Rα in orbital connective tissue. Furthermore, we elucidated the regulatory factors, profibrotic function, and downstream signaling pathways for IL-11 in TAO using in vitro studies. IL-11 levels in serum and orbital connective tissues were increased in patients with TAO, as compared with healthy controls. In addition, both levels were positively correlated with disease activity. Single-cell RNA sequencing of orbital connective tissue indicated that IL-11Rα was dominantly expressed in orbital fibroblasts (OFs). RNA sequencing of paired unstimulated and transforming growth factor (TGF)-β1-stimulated samples demonstrated that upregulation of IL-11 expression defined the dominant transcriptional response. IL-11 signaling was also confirmed to be downstream of TGF-β1 and IL-1β. Therefore, we deduced that IL-11 protein is secreted in an autocrine loop in TAO. We also indicated that IL-11 mediated the profibrotic phenotype switch by inducing the expression of myofibroblast differentiation markers, including α-smooth muscle actin and collagen type I α1, which could be abrogated by an anti-IL-11 neutralizing antibody. Furthermore, we revealed that extracellular regulated protein kinase may be a crucial factor in the pro-fibrotic, translationally specific signaling activity of IL-11. These data demonstrate that IL-11 plays a crucial role in orbital fibroblast phenotype switching and may be a potential therapeutic target candidate for the treatment of TAO.

    View details for DOI 10.3389/fendo.2022.846106

    View details for PubMedID 35273577

    View details for PubMedCentralID PMC8902078

  • A Novel Risk Model Based on Autophagy Pathway Related Genes for Survival Prediction in Lung Adenocarcinoma. Medical science monitor : international medical journal of experimental and clinical research Zhang, F., Xie, S., Zhang, Z., Zhao, H., Zhao, Z., Sun, H., Zheng, J. 2020; 26: e924710

    Abstract

    BACKGROUND Autophagy has a principal role in mediating tumor cell metabolism. However, the role of autophagy-pathway-related genes (APRGs) as prognostic markers remains obscure in lung adenocarcinoma (LUAD). More potential prognostic biomarkers are needed to deepen our understanding to explore the prognostic role of APRGs in LUAD. MATERIAL AND METHODS We used The Cancer Genome Atlas (TCGA) database to identify differentially expressed APRGs. Cox proportional hazard regression was used to identify prognostic APRGs, and then a risk model was constructed. The efficacy of the risk model was confirmed using a testing group. Lastly, we explored mutational signatures of prognostic of APRGs. T-tests were used to analyze all the expression patterns of genes by SPSS 19.0. RESULTS Using TCGA database, 5 differently expressed APRGs were identified in LUAD patients, and functional enrichment analyze of the genes that were closely associated with the survival status in LUAD patients. Cox proportional hazard regression was facilitated to identify 9 APRGs (CCR2, LAMP1, RELA, ATG12, ATG9A, NCKAP1, ATG10, DNAJB9, and MBTPS2). Multivariate Cox proportional hazards regression analyses further identified 5 key prognostic APRGs (CCR2, LAMP1, RELA, ATG12, and MBTPS2) that were closely related to the survival status in LUAD. Then the prognostic scores based on the 5 genes as independent prognostic indicators were constructed for overall survival (OS) of LUAD patients; area under the curve (AUC) values >0.70 (all P<0.05). The efficacy of prognostic scores was confirmed by data from the testing group and showed significant differences between the low-risk and the high-risk groups for OS (P<0.05). CONCLUSIONS The risk model based on the construction of 5 APRGs can predict the prognosis of patients with LUAD, which may potentially predict prognostic signatures for LUAD.

    View details for DOI 10.12659/MSM.924710

    View details for PubMedID 32873769

    View details for PubMedCentralID PMC7486793

  • Identification of candidate aberrantly methylated and differentially expressed genes in Esophageal squamous cell carcinoma. Scientific reports Han, B., Yang, X., Hosseini, D. K., Zhang, P., Zhang, Y., Yu, J., Chen, S., Zhang, F., Zhou, T., Sun, H. 2020; 10 (1): 9735

    Abstract

    Aberrant methylated genes (DMGs) play an important role in the etiology and pathogenesis of esophageal squamous cell carcinoma (ESCC). In this study, we aimed to integrate three cohorts profile datasets to ascertain aberrant methylated-differentially expressed genes and pathways associated with ESCC by comprehensive bioinformatics analysis. We downloaded data of gene expression microarrays (GSE20347, GSE38129) and gene methylation microarrays (GSE52826) from the Gene Expression Omnibus (GEO) database. Aberrantly differentially expressed genes (DEGs) were obtained by GEO2R tool. The David database was then used to perform Gene ontology (GO) analysis and Kyoto Encyclopedia of Gene and Genome pathway enrichment analyses on selected genes. STRING and Cytoscape software were used to construct a protein-protein interaction (PPI) network, then the modules in the PPI networks were analyzed with MCODE and the hub genes chose from the PPI networks were verified by Oncomine and TCGA database. In total, 291 hypomethylation-high expression genes and 168 hypermethylation-low expression genes were identified at the screening step, and finally found six mostly changed hub genes including KIF14, CDK1, AURKA, LCN2, TGM1, and DSG1. Pathway analysis indicated that aberrantly methylated DEGs mainly associated with the P13K-AKT signaling, cAMP signaling and cell cycle process. After validation in multiple databases, most hub genes remained significant. Patients with high expression of AURKA were associated with shorter overall survival. To summarize, we have identified six feasible aberrant methylated-differentially expressed genes and pathways in ESCC by bioinformatics analysis, potentially providing valuable information for the molecular mechanisms of ESCC. Our data combined the analysis of gene expression profiling microarrays and gene methylation profiling microarrays, simultaneously, and in this way, it can shed a light for screening and diagnosis of ESCC in future.

    View details for DOI 10.1038/s41598-020-66847-4

    View details for PubMedID 32546690

  • Involvement of Advanced Glycation End Products in the Pathogenesis of Diabetic Retinopathy. Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology Xu, J., Chen, L. J., Yu, J., Wang, H. J., Zhang, F., Liu, Q., Wu, J. 2018; 48 (2): 705-717

    Abstract

    Diabetic retinopathy (DR) is a common and devastating microvascular complication of diabetes and a major cause of acquired blindness in young adults. Advanced glycation end products (AGEs) accumulated under hyperglycemic conditions are thought to play an important role in the pathogenesis of DR. AGEs can exert their deleterious effects by acting directly to induce aberrant crosslinking of extracellular matrix proteins, to increase vascular stiffness, altering vascular structure and function. Moreover, AGEs binding to the receptor for AGEs (RAGE) evokes intensive intracellular signaling cascades that leading to endothelial dysfunction, elaboration of key proinflammatory cytokines and proangiogenic factors, mediating pericyte apoptosis, vascular inflammation and angiogenesis, as well as breakdown of the inner blood-retinal barrier (BRB), the end result of all these events is damage to the neural and vascular components of the retina. Elucidation of AGE-induced mechanisms will help in the understanding of the complex cellular and molecular pathogenesis associated with DR. Novel anti-AGEs agents or AGE crosslink "breakers" are being investigated, it is hoped that in next few years, some of these promising therapies will be successfully applied in clinical context, aiming to reduce the major economical and medical burden caused by DR.

    View details for DOI 10.1159/000491897

    View details for PubMedID 30025404