Protective effect of alizarin on vascular endothelial dysfunction via inhibiting the type 2 diabetes-induced synthesis of THBS1 and activating the AMPK signaling pathway.

BACKGROUND: In this study, we investigated the protective effects of alizarin (AZ) on endothelial dysfunction (ED). AZ has inhibition of the type 2 diabetes mellitus (T2DM)-induced synthesis of thrombospondin 1 (THBS1). Adenosine 5'-monophosphate- activated protein kinase (AMPK), particularly AMPKα2 isoform, plays a critical role in maintaining cardiac homeostasis. PURPOSE: The aim of this study was to investigate the ameliorative effect of AZ on vascular injury caused by T2DM and to reveal the potential mechanism of AZ in high glucose (HG)-stimulated human umbilical vein endothelial cells (HUVECs) and diabetic model rats. STUDY DESIGN: HUVECs, rats and AMPK-/- transgenic mice were used to investigate the mitigating effects of AZ on vascular endothelial dysfunction caused by T2DM and its in vitro and in vivo molecular mechanisms. METHODS: In type 2 diabetes mellitus rats and HUVECs, the inhibitory effect of alizarin on THBS1 synthesis was verified by immunohistochemistry (IHC), immunofluorescence (IF) and Western blot (WB) so that increase endothelial nitric oxide synthase (eNOS) content in vitro and in vivo. In addition, we verified protein interactions with immunoprecipitation (IP). To probe the mechanism, we also performed AMPKα2 transfection. AMPK's pivotal role in AZ-mediated prevention against T2DM-induced vascular endothelial dysfunction was tested using AMPKα2-/- mice. RESULTS: We first demonstrated that THBS1 and AMPK are targets of AZ. In T2DM, THBS1 was robustly induced by high glucose and inhibited by AZ. Furthermore, AZ activates the AMPK signaling pathway, and recoupled eNOS in stressed endothelial cells which plays a protective role in vascular endothelial dysfunction. CONCLUSIONS: The main finding of this study is that AZ can play a role in different pathways of vascular injury due to T2DM. Mechanistically, alizarin inhibits the increase in THBS1 protein synthesis after high glucose induction and activates AMPKα2, which increases NO release from eNOS, which is essential in the prevention of vascular endothelial dysfunction caused by T2DM.

Citronellal alleviate macro- and micro-vascular damage in high fat diet / streptozotocin - Induced diabetic rats via a S1P/S1P1 dependent signaling pathway.

Citronellal (CT) is an acyclic monoterpene aldehyde isolated from lemon citronella, which could ameliorate vascular endothelial dysfunction in atherosclerosis in our previous study, however, whether CT can alleviate vascular endothelial dysfunction related with type 2 diabetes (T2DM) is still unknown. So, we investigated the role of CT in vascular dysfunction related to T2DM and the mechanism involved. T2DM rat model was induced by a single intraperitoneal injection of low-dose streptozotocin (STZ) (60 mg/kg) to rats fed with high-fat diet (HFD) (4 weeks). After treated with CT (150 mg/kg/d), both the thoracic aorta injury and micro-vascular pathological injury in T2DM rats ex vivo were alleviated, and the oxidative stress in T2DM rats treated with CT were attenuated, manifested as increased content of endothelial nitric oxide synthase (eNOS) and superoxide dismutase (SOD), and decreased content of malondialdehyde (MDA). Furthermore, CT (15 µg/L) increased the migration capacity of human umbilical vein endothelial cells (HUVECs) under high glucose circumstance (30 mM), and increased the endothelial-dependent relaxation in thoracic aorta isolated from T2DM rats in vitro. Finally, all of these effects of CT were blocked by fingolimod (FTY720), a sphingosine-1-phosphate receptor agonist, and the expression of sphingosine-1-phosphate receptor 1 (S1P1) was increased by CT. In conclusion, CT improved vascular function through S1P/S1P1 signaling pathway.

Perillaldehyde improves cognitive function in vivo and in vitro by inhibiting neuronal damage via blocking TRPM2/NMDAR pathway.

BACKGROUND: Vascular cognitive dysfunction in patients with vascular dementia (VD) is a kind of severe cognitive dysfunction syndrome caused by cerebrovascular diseases. At present, effective drugs to improve the cognitive function of VD patients still need to be explored. Transient Receptor Potential Melastatin 2 (TRPM2) channel is a nonspecific cation channel that plays a key role in the toxic death of neurons. Perillaldehyde (PAE) has the protective effect of epilepsy and insomnia and other central nervous system diseases. The aim of this study is to explore whether PAE improves cognitive function in VD rats and to investigate the potential mechanisms in vivo and vitro. METHODS: VD rats were induced by bilateral common carotid arteries occlusion (2-vessel occlusion [2VO]) and treated with PAE for 4 weeks. The neuroprotective effects of PAE was subsequently assessed by the Morris water maze, hematoxylin-eosin (HE) staining, Golgi staining, electron microscopy, Neuron-specific nuclear protein (Neu N) staining, and TdT-mediated dUTP nick end labeling (TUNEL) staining. After primary hippocampal neurons were isolated, cell viability was detected by MTT assay and intracellular Ca2+ concentration was detected by calcium imaging assay. The content of Nitriteoxide (NO), Malondialdehyde (MDA) and Superoxide dismutase (SOD) activity in serum of rats were observed by Enzyme Linked Immunosorbent Assay (ELISA). Immunohistochemistry, Western blot, and Confocal laser scanning were used to detect the expression levels of N-methyl-D-asprtate receptor-2B (NR2B) and TRPM2. RESULTS: The results showed that PAE can improve the number and activity of neurons, increase the length and number of dendrites in hippocampus, decrease the Vv value and PE value of neuronal nucleus and mitochondrial structure significantly, increase the s value and L value in nucleus structure, decrease the s value and L value in mitochondrial structure, and improve the learning and memory ability of rats significantly. And PAE can strengthen the ability of antioxidant stress confirmed by increasing the activity of SOD and reducing the production of MDA. The results of western blot, immunohistochemistry and immunofluorescence showed that PAE could reduce the level of TRPM2 and increase the expression of NR2B. CONCLUSIONS: Taken together, our findings provide evidence that the neuroprotective effects of PAE in VD rats maybe through TRPM2 inhibition and subsequent activation of NMDAR signaling pathway.

Effect of initiation of renal replacement therapy on mortality in acute pancreatitis patients.

This study aims to explore effect of initiation of renal replacement therapy (RRT) on mortality in acute pancreatitis (AP) patients. In this study, a total of 92 patients from the surgical intensive care unit (SICU) of the Second Affiliated Hospital of Harbin Medical University who were diagnosed with AP and underwent RRT or not between January 2014 and December 2018 were included in this retrospective study. Demographic and clinical data were obtained on admission to SICU. Patients were divided into early initiation of RRT group (n = 44) and delayed initiation of RRT group (n = 48). Duration of mechanical ventilation (MV), intra-peritoneal pressure, vasopressors infusion, body temperature, procalcitonin, creatinine, platelet counts, length of hospital stay and prognosis were recorded during hospitalization, and then compared between groups. Patients with delayed initiation of RRT exhibited significantly higher APACHE II score, SOFA score and lower GCS score than those with early initiation of RRT (P < 0.001, <0.001,  = 0.04, respectively). No difference in the rest of the baseline data and vasopressors infusion was found. Dose of Norepinephrine, maximum and mean PCT, maximum and mean creatinine, maximum and mean intra-peritoneal pressure, length of hospital stay, prognosis of ICU and hospitalization showed significant difference between groups. Early initiation of RRT may be beneficial for AP patients, which can provide some insight and support for patients' treatment in clinic.