Efficacy of RAGE Inhibitor TTP488 in Reducing Retinal Inflammation in Diabetic Retinopathy Mice Model

doi:10.3870/j.issn.1672-8009.2026.03.008

Abstract

Abstract: Objective To explore the efficacy and mechanisms of the receptor for advanced glycation end products inhibitor TTP488 in reducing retinal inflammation. Methods Thirty male C57BL/6J mice were randomly divided into 3 groups(n=10 each):control group,type I diabetes mellitus(T1DM) model group,and T1DM+TTP488 group.A T1DM mice model induced by streptozotocin(STZ)was established.Immunofluorescent staining targeting microglial cell markers(Iba1)was used to determine the activation degree of Iba1-positive cells in the retinal tissues of mice;and ELISA was used to measure the levels of inflammatory factors TNF-α,IL-1β and IL-6 in them.mRPE cells was divided into the following 5 groups for the further in vitro cell experiments:control group,LPS group,LPS+TTP488 group,LPS+shRNA-P65 group,LPS+shRNA-NT group.Lipopolysaccharide(LPS)was used to establish the primary mouse retinal pigment epithelial cells inflammatory model.Adenovirus vector was used to mediate the knockdown of P65.The expression level of VEGF-D mRNA in cells was determined by RT-qPCR.The expression levels of phosphorylated NF-κB P65(p-P65)/P65 and VEGF-D in the retinal tissues of mice as well as in in vitro cells were determined by Western blotting. Results Compared with those in the T1DM model group,the number of Iba1 positive cell branches and the number of Iba1 positive cell branch connection points(per field)in the T1DM+TTP488 group were decreased(P<0.05).The levels of TNF-α,IL-1β,and IL-6 were decreased(P<0.05).The relative expression levels of p-P65/P65 and VEGF-D were decreased(P<0.05).Compared with those in the LPS group,the relative expression level of VEGF-D mRNA in the LPS+TTP488 group and the LPS+shRNA-P65 group was decreased(P<0.05).The relative expression levels of p-P65 and VEGF-D were down-regulated(P<0.05). Conclusion TTP488 reduced the expression of VEGF-D by inhibiting the activation of NF-κB,thereby alleviating retinal inflammation and tissue structural abnormalities in the diabetic retinopathic mice model.

Key words: diabetic retinopathy, inflammation, advanced glycation end products, receptor for advanced glycation end products, TTP488, vascular endothelial growth factor

CLC Number:

WANG Lan, LU Yi, ZOU Yunchun. Efficacy of RAGE Inhibitor TTP488 in Reducing Retinal Inflammation in Diabetic Retinopathy Mice Model[J]. Journal of Medical Molecular Biology, 2026, 23(3): 294-301.

References

[1] KOUR V,SWAIN J,SINGH J,et al.A review on diabetic retinopathy[J].Curr Diabetes Rev,2024,20(6):e201023222418.
[2] TEO Z L,THAM Y C,YU M,et al.Global prevalence of diabetic retinopathy and projection of burden through 2045:Systematic review and meta-analysis[J].Ophthalmology,2021,128(11):1580-1591.
[3] TWARDA-CLAPA A,OLCZAK A,BIAŁKOWSKA A M,et al.Advanced glycation end-products(AGEs):Formation,chemistry,classification,receptors,and diseases related to AGEs[J].Cells,2022,11(8):1312.
[4] SALEH I,MARITSKA Z,PARISA N,et al.Inhibition of receptor for advanced glycation end products as new promising strategy treatment in diabetic retinopathy[J].Open Access Maced J Med Sci,2019,7(23):3921-3924.
[5] FURMAN B L.Streptozotocin-induced diabetic models in mice and rats[J].Curr Protoc,2021,1(4):e78.
[6] OLIVEIRA A L,MEDEIROS M L,CAMPOS A T P,et al.The RAGE inhibitor TTP488(azeliragon)improves diabetic bladder dysfunction in leptin-deficient obese mice[J].Antioxidants,2025,14(7):793.
[7] XUE J,JIA P,ZHANG D,et al.TTP488 ameliorates NLRP3-associated inflammation,viability,apoptosis,and ROS production in an Alzheimer’s disease cell model by mediating the JAK1/STAT3/NFκB/IRF3 pathway[J].Cell Biochem Funct,2021,39(4):555-561.
[8] CHONG D D,DAS N,SINGH R P.Diabetic retinopathy:Screening,prevention,and treatment[J].Cleve Clin J Med,2024,91(8):503-510.
[9] 欧阳芊芊,曾凤.铁死亡及其在糖尿病视网膜病变发病中的作用[J].国际眼科纵览,2025,49(3):197-202.
OUYANG Q Q,ZENG F.Ferroptosis and its role in the pathogenesis of diabetic retinopathy[J].Int Rev Oph,2025,49(3):197-202.
[10] 黄丹,邓芳祝,谢功泽,等.转录因子SP1调控MAP3 K1表达影响糖尿病视网膜病变细胞凋亡和炎症反应[J].中国免疫学杂志,2024,40(3):519-523.
HUANG D,DENG F Z,XIE G Z,et al.Transcription factor SP1 regulates expression of MAP3 K1 and affects apoptosis and inflammatory response of diabetic retinopathy cells[J].Chin J Immunol,2024,40(3):519-523.
[11] XIA Y,LUO Q,CHEN J,et al.Retinal astrocytes and microglia activation in diabetic retinopathyRhesusMonkey models[J].Curr Eye Res,2022,47(2):297-303.
[12] ZHONG H,YU H,SUN J,et al.Isolation of microglia from retinas of chronic ocular hypertensive rats[J].Open Life Sci,2021,16(1):992-1001.
[13] BRUERA M G,BENEDETTO M M,GUIDO M E,et al.Glial cell response to constant low light exposure in rat retina[J].Vis Neurosci,2022,39:E005.
[14] GONZÁLEZ IBANEZ F,PICARD K,BORDELEAU M,et al.Immunofluorescence staining using IBA1 and TMEM119 for microglial density,morphology and peripheral myeloid cell infiltration analysis in mouse brain[J].JoVE,2019(152).
[15] DIAS C G,VENKATASWAMY L,BALAKRISHNA S.Diabetic nephropathy patients show hyper-responsiveness to N6-carboxymethyllysine[J].Braz J Med Biol Res,2022,55:e11984.
[16] LI L,DAI Y,KE D,et al.Ferroptosis:new insight into the mechanisms of diabetic nephropathy and retinopathy[J].Front Endocrinol,2023,14:1215292.
[17] KONG H,ZHAO H,CHEN T,et al.Targeted P2 X7/NLRP3 signaling pathway against inflammation,apoptosis,and pyroptosis of retinal endothelial cells in diabetic retinopathy[J].Cell Death Dis,2022,13(4):336.
[18] SUN K,CHEN Y,ZHENG S,et al.Genipin ameliorates diabetic retinopathyviathe HIF-1α and AGEs-RAGE pathways[J].Phytomedicine,2024,129:155596.
[19] MIN F,LI Z,LI Y,et al.The contribution of adiponectin to diabetic retinopathy progression:Association with the AGEs-RAGE pathway[J].Heliyon,2024,10(17):e36111.
[20] HUDSON B I,LIPPMAN M E.Targeting RAGE signaling in inflammatory disease[J].Annu Rev Med,2018,69:349-364.
[21] SANAJOU D,GHORBANI HAGHJO A,ARGANI H,et al.Reduction of renal tubular injury with a RAGE inhibitor FPS-ZM1,valsartan and their combination in streptozotocin-induced diabetes in the rat[J].Eur J Pharmacol,2019,842:40-48.
[22] YUE T,SHI Y,LUO S,et al.The role of inflammation in immune system of diabetic retinopathy:Molecular mechanisms,pathogenetic role and therapeutic implications[J].Front Immunol,2022,13:1055087.
[23] O’LEARY F,CAMPBELL M.The blood-retina barrier in health and disease[J].FEBS J,2023,290(4):878-891.
[24] NIAN S,LO A C Y,MI Y,et al.Neurovascular unit in diabetic retinopathy:Pathophysiological roles and potential therapeutical targets[J].Eye Vis,2021,8(1):15.
[25] AMOAKU W M,GHANCHI F,BAILEY C,et al.Diabetic retinopathy and diabetic macular oedema pathways and management:UK Consensus Working Group[J].Eye,2020,34(Suppl 1):1-51.