An experimental study of multimodal MRI technology for evaluating the impact of tanshinone ⅡA on glymphatic system function in rats with Alzheimer's disease

doi:10.11958/20260440

Abstract

Abstract:

Objective To evaluate the effects of tanshinone ⅡA (Tan-ⅡA) on glymphatic system function in Alzheimer's disease (AD) rats using multimodal MRI techniques. Methods Twelve male SD rats were randomly divided into the control group (healthy controls), the AD model group, the AD+Tan-ⅡA group and the AD+Tgn-073 group, with 3 rats in each group. Except for the control group, all remaining three groups underwent stereotaxic injection of Aβ1-40 to establish the AD model. Following modeling, the AD+Tan-ⅡA group and the AD+Tgn-073 group received four weeks of intervention with Tan-ⅡA and the AQP4 agonist Tgn-073, respectively. Multi-b-value diffusion-weighted imaging (DWI) was used to analyze water molecule diffusion characteristics in rat brain tissue, with calculation of the apparent diffusion coefficient (ADC), distributed diffusion coefficient (DDC) and heterogeneity index α. Dynamic contrast-enhanced MRI (DCE-MRI) and immunofluorescence were employed to assess signal intensity changes and aquaporin-4 (AQP4) expression in the hippocampal, striatal and cortical regions. Results Compared with the control group, the ADC, DDC and heterogeneity index α values were significantly decreased in the AD group (all P<0.01). Compared with the AD group, there were no statistically significant differences in ADC, DDC or α values in the AD+Tan-ⅡA group after drug intervention. In contrast, all three parameters were elevated in the AD+Tgn-073 group (P<0.05). DCE-MRI revealed that in the hippocampal and cortical regions, the signal intensity ratio was higher in the AD+Tgn-073 group than that of the AD group in the early post-contrast phase (40 or 60 min, P<0.05), whereas the AD+Tan-ⅡA group showed elevated signal intensity in the cortical region during the mid-to-late phase (100, 120, and 150 min, P<0.05). Immunofluorescence demonstrated that compared with the control group, AQP4 expression was elevated exclusively in the hippocampus of AD rats. Compared with the AD group, AQP4 expression was downregulated in both hippocampal and striatal regions of the AD+Tgn-073 group and the AD+Tan-ⅡA group. Conclusion Tan-ⅡA can improve glymphatic transport function in brain of AD rats, and the underlying mechanism may involve pathways that are not directly dependent on AQP4.

Key words: Alzheimer's disease, rats, MRI, tanshinone-ⅡA, glymphatic system

CLC Number:

R445.2，R749.16

Figures/Tables 5

Tab.1 Comparison of diffusion parameters（ADC，DDC and α） in brain of rats between the four groups （n=3，$\stackrel{-}{x}\pm s$）

组别	ADC/（×10^-3mm²/s）	DDC/（×10^-3mm²/s）	异质性指数α
Control组	1.11±0.03	0.83±0.10	0.84±0.02
AD组	0.61±0.04^a	0.42±0.05^a	0.64±0.03^a
AD+Tgn-073组	0.91±0.08^b	0.69±0.03^b	0.73±0.10^b
AD+Tan-ⅡA组	0.76±0.20	0.55±0.13	0.67±0.05
F	11.030^＊＊	14.120^＊＊	28.250^＊＊

Fig.1 Temporal trends of signal intensity variations in hippocampus, striatum and cortex of each group

Fig.2 Representative T1-weighted MR plain scan combined with contrast-enhanced images between the four groups

Tab.2 Comparison of AQP4 in hippocampus，striatum and cortex of rats between the four groups （n=12，$\stackrel{-}{x}\pm s$）

组别	海马	纹状体	皮质
Control组	0.98±0.08	0.99±0.05	1.00±0.04
AD组	1.28±0.08^a	0.98±0.13	0.94±0.10
AD+Tgn-073组	1.11±0.12^b	0.81±0.07^b	0.84±0.06^b
AD+Tan-ⅡA组	1.09±0.14^b	0.88±0.04^b	0.91±0.05
F	14.790^＊＊	13.210^＊＊	10.670^＊＊

Fig.3 Expression of AQP4 in the hippocampus, striatum and caudal cortex of rats in four groups (immunofluorescence staining, ×200)

References 31

[1]	Rostagno A A. Pathogenesis of Alzheimer's disease[J]. Int J Mol Sci, 2022, 24(1):1070. doi:10.3390/ijms24010107.
[2]	Buccellato F R, D'Anca M, Serpente M, et al. The role of glymphatic system in Alzheimer's and Parkinson's Disease pathogenesis[J]. Biomedicines, 2022, 10(9):2261. doi:10.3390/biomedicines10092261.
[3]	Chong P, Garic D, Shen M D, et al. Sleep,cerebrospinal fluid,and the glymphatic system:a systematic review[J]. Sleep Med Rev, 2022, 61:101572. doi:10.1016/j.smrv.2021.101572.
[4]	Hablitz L M, Nedergaard M. The glymphatic system:a novel component of fundamental neurobiology[J]. J Neurosci, 2021, 41(37):7698-7711. doi:10.1523/JNEUROSCI.0619-21.2021.
[5]	Harrison I F, Ismail O, Machhada A, et al. Impaired glymphatic function and clearance of tau in an Alzheimer's disease model[J]. Brain, 2020, 143(8):2576-2593. doi:10.1093/brain/awaa179.
[6]	Yamada K, Iwatsubo T. Involvement of the glymphatic/meningeal lymphatic system in Alzheimer's disease:insights into proteostasis and future directions[J]. Cell Mol Life Sci, 2024, 81(1):192. doi:10.1007/s00018-024-05225-z.
[7]	翟书鹏, 贾航, 苗统, 等. 帕金森病患者血清Trx1、PDCD4、AQP4水平与认知功能的关系[J]. 天津医药, 2025, 53(2):146-150.
	Zhai S P, Jia H, Miao T, et al. The relationship between serum Trx1,PDCD4,AQP4 expression and cognitive function in patients with Parkinson's disease[J]. Tianjin Med J, 2025, 53(2):146-150. doi:10.11958/20241632.
[8]	Liu X Q, Hu T, Wu G L, et al. Tanshinone IIA,the key compound in Salvia miltiorrhiza,improves cognitive impairment by upregulating Aβ-degrading enzymes in APP/PS1 mice[J]. Int J Biol Macromol, 2024, 254(Pt 2):127923. doi:10.1016/j.ijbiomac.2023.127923.
[9]	Peng X, Chen L, Wang Z, et al. Tanshinone IIA regulates glycogen synthase kinase-3β-related signaling pathway and ameliorates memory impairment in APP/PS1 transgenic mice[J]. Eur J Pharmacol, 2022, 918:174772. doi:10.1016/j.ejphar.2022.174772.
[10]	Alghanimy A, Martin C, Gallagher L, et al. The effect of a novel AQP4 facilitator,TGN-073,on glymphatic transport captured by diffusion MRI and DCE-MRI[J]. PLoS One, 2023, 18(3):e0282955. doi:10.1371/journal.pone.0282955.
[11]	朱青春, 崔国红, 邵水金, 等. 阿尔茨海默病大鼠自噬相关蛋白Beclin-1和凋亡相关蛋白p53表达变化及电针的调控作用[J]. 中国中医药信息杂志, 2014(9):68-71.
	Zhu Q C, Cui G H, Shao S J, et al. Expression changes of autophagy associated protein Beclin-1 and apoptosis associated protein p53 in rats with Alzheimer's disease and regulatory effects of electroacupuncture[J]. Chinese Journal of Information on TCM, 2014(9):68-71. doi:10.3969/j.issn.1005-5304.2014.09.020.
[12]	Yang P, Wang Z, Zhang Z, et al. The extended application of the rat brain in stereotaxic coordinates in rats of various body weight[J]. J Neurosci Methods, 2018, 307:60-69. doi:10.1016/j.jneumeth.2018.06.026.
[13]	Lopes D M, Wells J A, Ma D, et al. Glymphatic inhibition exacerbates tau propagation in an Alzheimer's disease model[J]. Alzheimers Res Ther, 2024, 16(1):71. doi:10.1186/s13195-024-01439-2.
[14]	Xavier A L R, Hauglund N L, Von Holstein-Rathlou S, et al. Cannula implantation into the cisterna magna of rodents[J]. J Vis Exp, 2018, 135:57378. doi:10.3791/57378.
[15]	Guo R, Lu F, Lin J, et al. Multi-b-value DWI to evaluate the synergistic antiproliferation and anti-heterogeneity effects of bufalin plus sorafenib in an orthotopic HCC model[J]. Eur Radiol Exp, 2024, 8(1):43. doi:10.1186/s41747-024-00448-y.
[16]	Zhang G, Yan R, Liu W, et al. Use of biexponential and stretched exponential models of intravoxel incoherent motion and dynamic contrast-enhanced magnetic resonance imaging to assess the proliferation of endometrial carcinoma[J]. Quant Imaging Med Surg, 2023, 13(4):2568-2581. doi:10.21037/qims-22-688.
[17]	Yushkevich P A, Piven J, Hazlett H C, et al. User-guided 3D active contour segmentation of anatomical structures: significantly improved efficiency and reliability[J]. Neuroimage, 2006, 31(3):1116-1128. doi:10.1016/j.neuroimage.2006.01.015.
[18]	陈宗勤, 鲍奕仿, 李郁欣. 早期阿尔茨海默病Aβ单抗治疗中淀粉样蛋白相关影像异常的研究进展[J]. 国际医学放射学杂志, 2025, 48(1):59-63.
	Chen Z Q, Bao Y F, Li Y X. Research progress on amyloid-related imaging abnormalities in early Alzheimer’s disease treated with Aβ monoclonal antibody[J]. Int J Med Radiol, 2025, 48(1):59-63. doi:10.19300/j.2025.Z21811.
[19]	Zhang H, Wei W, Zhao M, et al. Interaction between Aβ and Tau in the pathogenesis of Alzheimer's disease[J]. Int J Biol Sci, 2021, 17(9):2181-2192. doi:10.7150/ijbs.57078.
[20]	Silva I, Silva J, Ferreira R, et al. Glymphatic system,AQP4,and their implications in Alzheimer's disease[J]. Neurol Res Pract, 2021, 3(1):5. doi:10.1186/s42466-021-00102-7.
[21]	Peng W, Achariyar T M, Li B, et al. Suppression of glymphatic fluid transport in a mouse model of Alzheimer's disease[J]. Neurobiol Dis, 2016, 93:215-225. doi:10.1016/j.nbd.2016.05.015.
[22]	Fang L, Cheng H, Chen W, et al. Therapeutic effects of tanshinone IIA and Tetramethylpyrazine nanoemulsions on cognitive impairment and neuronal damage in Alzheimer's disease rat models[J]. J Pharm Pharmacol, 2024, 76(9):1169-1177. doi:10.1093/jpp/rgae069.
[23]	Yang L X, Luo M, Li S Y. Tanshinone IIA improves Alzheimer's disease via RNA nuclear-enriched abundant transcript 1/microRNA-291a-3p/member RAS oncogene family Rab22a axis[J]. World J Psychiatry, 2024, 14(4):563-581. doi:10.5498/wjp.v14.i4.563.
[24]	Du L, Xu B, Zhao Z, et al. Identification and classification of Alzheimer's disease patients using novel fractional motion model[J]. Front Neurosci, 2020, 14:767. doi:10.3389/fnins.2020.00767.
[25]	Xue Y, Zhang Z, Wen C, et al. Characterization of Alzheimer's disease using ultra-high b-values apparent diffusion coefficient and diffusion kurtosis imaging[J]. Aging Dis, 2019, 10(5):1026-1036. doi:10.14336/AD.2018.1129.
[26]	Syková E, VoríSek I, Antonova T, et al. Changes in extracellular space size and geometry in APP23 transgenic mice:a model of Alzheimer's disease[J]. Proc Natl Acad Sci U S A, 2005, 102(2):479-484. doi:10.1073/pnas.0408235102.
[27]	Mueggler T, Meyer-Luehmann M, Rausch M, et al. Restricted diffusion in the brain of transgenic mice with cerebral amyloidosis[J]. Eur J Neurosci, 2004, 20(3):811-817. doi:10.1111/j.1460-9568.2004.03534.x.
[28]	Chahardehi A M, Arefnezhad R, Pourbafrani A, et al. MicroRNAs modulation by curcumin,catalpol,and other natural products in Alzheimer's disease: a review[J]. Mol Biol Rep, 2025, 52(1):445. doi:10.1007/s11033-025-10543-x.
[29]	Salman M M, Kitchen P, Halsey A, et al. Emerging roles for dynamic aquaporin-4 subcellular relocalization in CNS water homeostasis[J]. Brain, 2022, 145(1):64-75. doi:10.1093/brain/awab311.
[30]	Hablitz L M, Plá V, Giannetto M, et al. Circadian control of brain glymphatic and lymphatic fluid flow[J]. Nat Commun, 2020, 11(1):4411. doi:10.1038/s41467-020-18115-2.
[31]	Barichello De Quevedo J L, Leffa D T, Pascoal T A. Glymphatic system waste clearance and Alzheimer's disease[J]. Braz J Psychiatry, 2023, 45(5):385-386. doi:10.47626/1516-4446-2023-0049.