Tetrahydrocurcumin Ameliorates Homocysteinylated Cytochrome-c Mediated Autophagy in Hyperhomocysteinemia Mice after Cerebral Ischemia

Abstract

High levels of homocysteine (Hcy) known as hyperhomocysteine-mia (HHcy), contribute to autophagy and ischemia/reperfusion injury (I/R). Previous studies have shown that I/R injury and HHcy cause increased cerebrovascular permeability; however, the associated mechanism remains obscure. Interestingly, during HHcy, cytochome-c becomes homocysteinylated (Hcy-cyto-c). Cytochrome-c (cyto-c) transports electrons and facilitates bioenergetics in the system. However, its role in autophagy during ischemia/reperfusion injury is unclear. Tetrahydrocurcumin (THC) is a major herbal antioxidant and anti-inflammatory agent. Therefore, the objective of this study was to determine whether THC ameliorates autophagy during ischemia/reperfusion injury by reducing homocysteinylation of cyto-c in hyperhomocysteinemia pathological condition. To test this hypothesis we employed 8–10 weeks old male cystathionine-beta-synthase heterozygote knockout (CBS+/−) mice (genetically hyperhomocystemic mice). Experimental group was: CBS+/−, CBS+/−+THC (25mg/kg in 0.1%DMSO dose); CBS (+/−)/I/R and CBS (+/−)/I/R+THC(25mg/kg in 0.1%DMSO dose). Ischemia was performed for 30 min and reperfusion for 72 hours. THC was injected intra-peritoneally (I.P.) once daily for a period of 3 days after 30 of ischemia. The infarct area was measured using 2,3,5-triphenyltetrazolium chloride staining. Permeability was determined by brain edema and Evans Blue extravasation. The brain tissues were analyzed for oxidative stress, matrix metalloproteinase-9 (MMP-9), damage-regulated autophagy modulator (DRAM), and microtubule-associated protein 1 light chain 3 (LC3) by Western blot. The mRNA levels of S-Adenosyl-L-homocysteine hydrolases (SAHH) and Methylenetetrahydrofolate reductase (MTHFR) genes were measured by Quantitative real-time polymerase chain reaction. Co-immunoprecipitation was used to determine the homocysteinylation of cyto-c. We found that brain edema and Evans Blue leakage were reduced in I/R+THC treated groups as compared to sham operated groups along with reduced brain infarct size. THC also decreased oxidativedamage and ameliorated the homocysteinylation of cyto-c in-part by MMP-9 activation which leads to autophagy in I/R groups as compared to sham operated groups. This study suggests a potential therapeutic role of dietary THC in cerebral ischemia.

Inhibition of MMP-9 attenuates hypertensive cerebrovascular dysfunction in Dahl salt-sensitive rats

“…Normalization of MMP-9 with GM6001 in Dahl-SS rats suggested alleviation of cerebral pathology. A large body of evidence suggest that MMPs are induced under oxidative stress [32, 33], and reduction in MMPs can prevent oxidative stress [34]. The ongoing research clearly indicates that the regulated activity of MMP-9 is critical for cerebral development and functions [35].…”

“…The induction of MMP-9 has been reported in many basic and clinical studies where MMP-9 was found to be associated in cerebral pathologies [15, 36–38]. Although several studies suggest that oxidative-nitrosative stress induces MMP-9 [15, 32, 33], some studies also indicate that MMPs are upstream of ROS generation [39], and a decrease in MMPs can decrease oxidative stress [34]. In a recent study, using double transgenic mouse model of Alzheimer’s disease, GM6001 treatment decreased the MMP activity and oxidative stress [40].…”

Epigenetic impact of curcumin on stroke prevention

“…The neuroprotective effect of curcumin is well documented over different neurotoxicants; such as Hcy (Kalani et al 2013a). These protective effects not only rescue the metabolite alterations but also improve brain edema, Evans Blue leakage and infarct size during ischemic brain injury (stroke) (Tyagi et al 2012). The beneficiary effect of curcumin is also reported to be executed by lowering lipid peroxidation, when administered orally or intraperitoneally (Ghoneim et al 2002; Thiyagarajan and Sharma, 2004).…”

“…In addition, curcumin appears to have potential to inhibit amyloid beta oligomers and fibrils formation in mice (Yang et al 2005). The therapeutic efficacy of curcumin in middle cerebral artery occlusion (MCAO) models of rat and mice has also been explored (Lapchak et al 2011; Shukla et al 2008; Tyagi et al 2012; Zhao et al 2010). Studies suggest that curcumin overcomes cerebral ischemia by its neuro-protective and anti-oxidative properties (Strimpakos and Sharma, 2008; Tyagi et al 2012).…”

“…The therapeutic efficacy of curcumin in middle cerebral artery occlusion (MCAO) models of rat and mice has also been explored (Lapchak et al 2011; Shukla et al 2008; Tyagi et al 2012; Zhao et al 2010). Studies suggest that curcumin overcomes cerebral ischemia by its neuro-protective and anti-oxidative properties (Strimpakos and Sharma, 2008; Tyagi et al 2012). Besides exhibiting anti-inflammtory, anti-lipidemic, and anti-oxidative properties, curcumin also induces signs of epigenetic changes (Chiu et al 2013; Hardy and Tollefsbol, 2011; Martin et al 2013; Teiten et al 2013); however the epigenetic influence of curcumin on stroke epigenetics is needed to be explored.…”