Evaluation of cardiac histology and cell death markers during the progression of diabetes in a streptozotocin-induced diabetes rat model

Abstract

The simultaneous characterization of histological alterations and distinct cell death pathways associated with diabetic cardiomyopathy (DCM) has not been comprehensively explored and may differ depending on the experimental model. We evaluated cardiac histological changes and markers of apoptosis, cell death associated with mitochondrial permeability transition pore (mPTP) opening (necrosis), and autophagy in early and advanced stages of streptozotocin (STZ)-induced diabetes in rats receiving insulin daily to prevent mortality while maintaining hyperglycemia. Adult male Sprague–Dawley rats (n = 4–5) were randomly assigned to receive STZ (diabetic group) or saline (mock) and followed up for 4 or 12 weeks. Hearts were processed for histological examination and immunohistochemical detection of active caspase-3, beclin-1, and cyclophilin D. STZ significantly increased glycemia at both time points, whereas body weight reduction was observed only at 12 weeks. No evidence of cardiac hypertrophy, fibrosis, or structural injury was detected in diabetic rats at either stage. Expression of caspase-3, beclin-1, and cyclophilin D decreased at 12 weeks compared with 4 weeks, regardless of treatment; however, cyclophilin D was elevated in diabetic hearts at 4 weeks. These results suggest an early susceptibility to mPTP opening under persistent hyperglycemia, despite the absence of overt histological damage. They also underscore the critical importance of insulin dosing and study duration when interpreting data from STZ-based models. Further studies are warranted to determine how even minimal insulin administration may shape the temporal dynamics of cell death during the progression of DCM.

Keywords

cell death markers / diabetic cardiomyopathy / histology / insulin / streptozotocin-induced diabetic rats

References

[1] Ong KL, Stafford LK, McLaughlin SA, et al. Global, regional, and national burden of diabetes from 1990 to 2021, with projections of prevalence to 2050: a systematic analysis for the global burden of disease study 2021. Lancet. 2023; 402(10397): 203-234.

[2] Leiva AM, Martínez MA, Petermann F, et al. Risk factors associated with type 2 diabetes in Chile. Nutr Hosp [Online]. 2018; 35(2): 400-407.

[3] Einarson TR, Acs A, Ludwig C, Panton UH. Prevalence of cardiovascular disease in type 2 diabetes: a systematic literature review of scientific evidence from across the world in 2007–2017. Cardiovasc Diabetol. 2018; 17(1):83.

[4] Rubler S, Dlugash J, Yuceoglu YZ, Kumral T, Branwood AW, Grishman A. New type of cardiomyopathy associated with diabetic glomerulosclerosis. Am J Cardiol. 1972; 30(6): 595-602.

[5] Jia G, Hill MA, Sowers JR. Diabetic cardiomyopathy: an update of mechanisms contributing to this clinical entity. Circ Res. 2018; 122(4): 624-638.

[6] Kanamori H, Naruse G, Yoshida A, et al. Morphological characteristics in diabetic cardiomyopathy associated with autophagy. J Cardiol. 2021; 77(1): 30-40.

[7] Pop-Busi R, Januzzi JL, Bruemmer D, et al. Heart failure: an underappreciated complication of diabetes. A Consensus report of the American Diabetes Association Diabetes Care. Diabetes Care. 2022; 45(7): 1670-1690.

[8] Paolillo S, Marsico F, Prastaro M, et al. Diabetic cardiomyopathy: definition, diagnosis, and therapeutic implications. Heart Fail Clin. 2019; 15(3): 341-347.

[9] Gu X, Shi Y, Chen X, et al. Isoliquiritigenin attenuates diabetic cardiomyopathy via inhibition of hyperglycemia-induced inflammatory response and oxidative stress. Phytomedicine. 2020; 78:153319.

[10] Chen Y, Hua Y, Li X, Arslan IM, Zhang W, Meng G. Distinct types of cell death and the implication in diabetic cardiomyopathy. Front Pharmacol. 2020; 11:42.

[11] Bhattacharya D, Mukhopadhyay M, Bhattacharyya M, Karmakar P. Is autophagy associated with diabetes mellitus and its complications? A review. EXCLI J. 2018; 17: 709-720.

[12] Xu H, Yu Z, Zhu J, et al. Types of cell death in diabetic cardiomyopathy: insights from animal models. Acta Biochim Biophys Sin Shanghai. 2024; 57(5): 681-689.

[13] Lennikov A, ElZaridi F, Yang M. Modified streptozotocin-induced diabetic model in rodents. Animal Model Exp Med. 2024; 7(5): 777-780.

[14] Bugger H, Abel ED. Rodent models of diabetic cardiomyopathy. Dis Model Mech. 2009; 2(9–10): 454-466.

[15] Ghasemi A, Jeddi S. Streptozotocin as a tool for induction of rat models of diabetes: a practical guide. EXCLI J. 2023; 22: 274-294.

[16] Wang-Fischer Y, Garyantes T. Improving the reliability and utility of streptozotocin-induced rat diabetic model. J Diabetes Res. 2018; 2018:8054073.

[17] Tang SG, Liu XY, Ye JM, et al. Isosteviol ameliorates diabetic cardiomyopathy in rats by inhibiting ERK and NF-κB signaling pathways. J Endocrinol. 2018; 238(1): 47-60.

[18] Jasińska-Stroschein M. The current state of preclinical modeling of human diabetic cardiomyopathy using rodents. Biomed Pharmacother. 2023; 168:115843.

[19] Raish M, Ahmad A, Bin Jardan YA, et al. Sinapic acid ameliorates cardiac dysfunction and cardiomyopathy by modulating NF-κB and Nrf2/HO-1 signaling pathways in streptozocin-induced diabetic rats. Biomed Pharmacother. 2022; 145:112412.

[20] Mukai N, Nakayama Y, Abdali SA, Yoshioka J. Cardiomyocyte-specific Txnip C247S mutation improves left ventricular functional reserve in streptozotocin-induced diabetic mice. Am J Physiol Heart Circ Physiol. 2021; 321(2): H259-H274.

[21] Ti Y, Xie GL, Wang ZH, et al. TRB3 gene silencing alleviates diabetic cardiomyopathy in a type 2 diabetic rat model. Diabetes. 2011; 60(11): 2963-2974.

[22] Fang WJ, Wang CJ, He Y, Zhou YL, Peng XD, Liu SK. Resveratrol alleviates diabetic cardiomyopathy in rats by improving mitochondrial function through PGC-1α deacetylation. Acta Pharmacol Sin. 2018; 39(1): 59-73.

[23] Moore A, Shindikar A, Fomison-Nurse I, et al. Rapid onset of cardiomyopathy in STZ-induced female diabetic mice involves the downregulation of pro-survival Pim-1. Cardiovasc Diabetol. 2014; 13:68.

[24] Wu J, Yan LJ. Streptozotocin-induced type 1 diabetes in rodents as a model for studying mitochondrial mechanisms of diabetic β cell glucotoxicity. Diabetes Metab Syndr Obes. 2015; 8: 181-188.

[25] Wang Y, Sun H, Zhang J, Xia Z, Chen W. Streptozotocin-induced diabetic cardiomyopathy in rats: ameliorative effect of PIPERINE via Bcl2, Bax/Bcl2, and caspase-3 pathways. Biosci Biotechnol Biochem. 2020; 84(12): 2533-2544.

[26] Yu X, Tesiram YA, Towner RA, et al. Early myocardial dysfunction in streptozotocin-induced diabetic mice: a study using in vivo magnetic resonance imaging (MRI). Cardiovasc Diabetol. 2007; 19(6):6.

[27] Othman AI, El-Sawi MR, El-Missiry MA, Abukhalil MH. Epigallocatechin-3-gallate protects against diabetic cardiomyopathy through modulating the cardiometabolic risk factors, oxidative stress, inflammation, cell death and fibrosis in streptozotocin-nicotinamide- induced diabetic rats. Biomed Pharmacother. 2017; 94: 362-373.

[28] Xu X, Kobayashi S, Chen K, et al. Diminished autophagy limits cardiac injury in mouse models of type 1 diabetes. J Biol Chem. 2013; 288(25): 18077-18092.

[29] Xiao Y, Wu QQ, Duan MX, et al. TAX1BP1 overexpression attenuates cardiac dysfunction and remodeling in STZ-induced diabetic cardiomyopathy in mice by regulating autophagy. Biochim Biophys Acta Mol Basis Dis. 2018; 1864(5): 1728-1743.

Rights & permissions

2026 The Author(s). Animal Models and Experimental Medicine published by John Wiley & Sons Australia, Ltd on behalf of The Chinese Association for Laboratory Animal Sciences.