Kun Liu,Can Hu,Wenjun Yin,Lingyun Zhou,Xurui Gu,Xiaocong Zuo
Contrast-induced nephropathy (CIN) is an acute kidney injury (AKI) observed after the administration of contrast media. Calcium channel blockers (CCBs) have been reported to exert a renal protective effect. This study aims to investigate the role of cilnidipine, a novel CCBs, on CIN by regulating the calcium/calmodulin-dependent protein kinase Ⅱ(CaMKⅡ)/mitochondrial permeability transition pore (mPTP) pathway. Here, iohexol, a representative contrast media, was used to establish CIN model. KN-93 (CaMKⅡ inhibitor) and atractyloside (mPTP opener) were administered in rats, and CaMKⅡ overexpression was used in Human proximal tubular epithelial cells. Markers of renal injury (serum creatinine, blood urea nitrogen, and urinary NAGL), hematoxylin-eosin stain, oxidative stress (ROS, superoxide dismutase [SOD], and malondialdehyde [MDA] levels), cell death (MTT and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling [TUNEL]), mitochondrial function (mPTP, mitochondrial membrane potential [MMP], and ATP) were assessed. Western blots were used to measure the expression levels of Bax/Bcl-2, caspase-3, CaMKⅡ/mPTP signaling pathways. Results showed that cilnidipine markedly improved kidney function, and alleviated tubular cell apoptosis, oxidative stress and mitochondrial damage induced by iohexol in vitro and in vivo. The underlying mechanism may be that cilnidipine relieved CaMKⅡ activation and mPTP opening induced by iohexol. All of these protective effects of cilnidipine were attenuated by CaMKⅡ overexpression and atractyloside (mPTP opener) pretreatment. Moreover, KN-93 (CaMKⅡ inhibitor) treatment showed a similar renal protective effect with cilnidipine, while the protective effect of cilnidipine on kidney in CIN rats was not further suppressed by KN-93 cotreatment. These in vitro and in vivo results point toward the fact that cilnidipine might be a novel therapeutic drug against contrast-induced nephrotoxicity in a CaMKⅡ-dependent manner.
The peptide Ser-Phe-Gly-Asp-Ile (SFGDI), derived from sea cucumber, has demonstrated neuroprotective effects in cell models; however, the in vivo neuroprotective efficacy of SFGDI remains unexplored. In this study, we utilized a cognitive disorder mouse model induced by scopolamine and observed that daily oral administration of SFGDI at a dosage of 40 mg/kg resulted in improved behavioral performance in the Passive avoidance test, the Channel-type water maze test, and the Novel object recognition test (P < 0.05). Furthermore, our investigation into the underlying neuroprotective mechanisms of SFGDI revealed that it reduced oxidative stress levels through the activation of the Sirt3/SOD/ROS pathway, thereby balancing hippocampal unsaturated lipids (P < 0.05) in the mouse hippocampus. Moreover, SFGDI significantly decreased hippocampal neuroinflammation by modulating the activation of microglia and hypertrophy of astrocytes. Additionally, SFGDI was found to enhance synaptic plasticity in the mouse hippocampus by activating the ChAT/p-CaMKⅡ/BDNF pathway and increasing spine density in neuron cells (P < 0.05), particularly mushroom spines (P < 0.05). These experiments demonstrate that SFGDI exhibits neuroprotective effects by regulating hippocampal oxidative stress through the Sirt3/SOD/ROS pathway and synaptic plasticity via the ChAT/p-CaMKⅡ/BDNF pathway in the mouse hippocampus, thus emerging as a potential neuro-nutraceutical agent for alleviating memory impairment.
Juan Li,Zhen Li,Yanbo Liu,Yijing Li,Yanqiong Wu,Anne Manyande,Zhixiao Li,Hongbing Xiang
Summary The pathogenesis of hyperalgesia is complex and can lead to poor clinical treatment. Our study revealed that epididymal white adipose tissue (eWAT) from spared nerve injury (SNI) mice is involved in the occurrence of hyperalgesia after adipose tissue transplantation. We also showed that lysophosphatidylcholine (LPC) is enriched in the eWAT of SNI mice using non-targeted metabolomic analysis and verified that the levels of LPC in plasma and the anterior cingulate cortex (ACC) region increased following eWAT transplantation. Based on the immunohistochemistry results, we observed that LPC in the ACC region activated microglia via the TRPV1/CamkⅡ pathway. Meanwhile, the disruption of perineuronal nets (PNNs) around PV + neurons in ACC promoted hyperalgesia, and the loss of PNNs and PV + interneurons might be due to microglial phagocytosis. These findings elucidate the mechanism underlying hyperalgesia from the perspective of lipid metabolite LPC and PNNs and provide potential strategies for the treatment of hyperalgesia.