Long-Term Systemic Treatment With Methamphetamine Causes Retinal Damage in CD1 Mice
Authors: Liming Tao
Haojiang Yang
Lin Li
Journal: International journal of toxicology (0)
Discipline: PHARMACOLOGY & TOXICOLOGY
Keywords: CD1 mice; inflammatory response; methamphetamine; retina damage.
Affiliations: Department of Ophthalmology, The Second Hospital Affiliated to Anhui Medical University, Hefei, People's Republic of China., Department of Ophthalmology, Shenzhen Second People's Hospital, Shenzhen, People's Republic of China.

Abstract:  As a powerful psychostimulant with high potential for abuse, methamphetamine (Meth) could cause long-lasting abnormalities in retinas. The purpose of this study was to investigate the effects of systemic administration of Meth at low dose on retinal damage and understand the underlying mechanisms of pathology. CD1 mice were treated with 0.5 mg/kg or 1 mg/kg Meth by intraperitoneal injection daily for 2 months, mice treated with saline were used as negative control. Electroretinography (ERG) reflects the mass response of photoreceptor cells and was used to test the outer retinal function after Meth treatment. Toluidine blue staining was used to show the retinal morphology and evaluate the photoreceptor cell loss. Inflammatory factors were measured by enzyme-linked immunosorbent assay to show the inflammatory response. Terminal deoxynucleotidyl transferase dUTP Nick end labeling assay was used to detect the apoptosis-positive cells. Real-time polymerase chain reaction and Western blot were applied to measure the gene and protein change to explore the underlying mechanisms. Results demonstrated that retinal damage was caused by Meth treatment after 2 months, evidenced by loss of rod photoreceptor cells; decreased ERG amplitude; increased apoptotic photoreceptor cells, cytochrome-c release, caspase-3 activity, caspase-9 activity, and apoptosis-related protein expression; increased malondialdehyde level as well as nicotinamide adenine dinucleotide phosphate oxidase 4 protein expression; decreased anti-oxidative agents glutathione as well as superoxide dismutase levels; and increased production and gene expression of inflammatory factors. Our study indicated that systemic administration of Meth caused neurotoxic effects on CD1 mouse retinas, providing the potential mechanisms for the retina damage caused by Meth abuse. 

Retracted: No

PubPeer comments:
 Figure 2A (below) makes an appearance in another meth paper and also one about THC. ![file] Compare to Fig 2A of: Zhang et al. (2019) Systemic administration with tetrahydrocannabinol causes retinal damage in BALB c mice. Human Experimental Toxicology, https: doi.org 10.1177 0960327119886037 ![file] Also compare to Figure 2A of: Zhang et al. (2020) Methamphetamine causes acute toxicity in the retina of Balb c mice, Cutaneous and Ocular Toxicology, https: doi.org 10.1080 15569527.2020.1722153 ![file] , 
 Kudos to Sage Publishers for retracting this paper! They had a 2nd paper with the same images, see: https: pubpeer.com publications D1C94C1967ACD21989180D047610ED The retraction note reads as follows: At the request of the Journal Editor and SAGE Publishing, the following article has been retracted. J Jiang and H Xu. Long-term systemic treatment with lysergic acid diethylamide causes retinal damage in CD1 mice. Human and Experimental Toxicology 2019; 38(3): 347-355. DOI: 10.1177 0960327118814162 The above paper has substantial unreferenced overlap with the following paper: Haojiang Yang, Liming Tao, Lin Li. Long-Term Systemic Treatment With Methamphetamine Causes Retinal Damage in CD1 Mice. International Journal of Toxicology2018; 3(6): 448-456. DOI: 10.1177 1091581818809356 , 
 Unfortunately, there is a 5th paper with these images, the second for the journal Cutaneous and Ocular Toxicology. This one represents the retinas of CD1 mice given MDMA. Xiu-Fang Lv, Li-Ming Tao Hui Zhong (2019) Long-term systemic administration with low dose of 3,4-methylenedioxymethamphetamine causes photoreceptor cell damage in CD1 mice, Cutaneous and Ocular Toxicology, http: doi.org 10.1080 15569527.2018.1539007 Figure 2A: ![file] , 
 For reference, here is the second article from SAGE that has not been retracted: Figure 2B from: Y Ma et al (2020) 3,4-Methylenedioxymethamphetamine causes retinal damage in C57BL 6J mice. Human Experimental Toxicology, https: doi.org 10.1177 0960327120930253 ![file] , 
 #3 The [parallel paper on methylenedioxymethamphetamine] , in *Cutaneous and Ocular Toxicology*, has been retracted [30 March 2021] . -------------------------- We, the Editor and Publishers of *Cutaneous and Ocular Toxicology* have retracted the following article: Xiu-Fang Lv, Li-Ming Tao Hui Zhong (2019) Long-term systemic administration with low dose of 3,4-methylenedioxymethamphetamine causes photoreceptor cell damage in CD1 mice, Cutaneous and Ocular Toxicology, 38:1, 81-87, DOI: 10.1080 15569527.2018.1539007 An investigation was conducted and Figure 1d in the paper was found to be duplicated in another published article: Haojiang Yang, Liming Tao, Lin Li. (2015) Long-Term Systemic Treatment With Methamphetamine Causes Retinal Damage in CD1 Mice. International Journal of Toxicology, 37: 6, 448-456, DOI: 10.1177 1091581818809356 (see Figure 1F) When approached for an explanation, the authors did not provide their original data or any necessary supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. All authors listed in this publication have been informed. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as u201cRetractedu201d. , 
 #2 Fig 2A again: ![] Annotated to show the overlap with Fig 3a from  Long-term systemic treatment with lysergic acid diethylamide causes retinal damage in CD1 mice ([Jiang Xu 2019] ) *[retracted]*. ![file] ,