RESUMEN
Background: This study aimed to investigate the effect and mechanism of gambogic acid (GA) on the apoptosis and inflammation of human retinal endothelial cells (HRECs) under high glucose conditions. Methods: HRECs were cultured in a high glucose medium to simulate retinal endothelial cell injury induced by diabetic retinopathy. Flow cytometry was used to analyze the apoptosis level of HRECs. Cell viability was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). Western blotting was applied to detect the intracellular apoptosis-related proteins and expression levels of NADPH oxidase 4 (NOX4), nucleotide-binding oligomerization domain-like receptor protein 3 (NLRP3), and interleukin (IL)-1ß. Enzyme linked immunosorbent assay (ELISA) was utilized to detect the expression of IL-6, IL-8, IL-10, and tumor necrosis factor-α (TNF-α) in the cell supernatants. The messenger RNA (mRNA) levels of IL-6, IL-8, IL-10, and TNF-α were detected by reverse transcription-polymerase chain reaction (RT-qPCR). Results: We observed that high glucose induced the apoptosis and inflammation of HRECs. In addition, the high glucose environment promoted NOX/NLRP3 pathway activation. The activity of HRECs was not significantly affected by the presence of 20 µM or less of GA, and 15 µM of GA could restore the diminished activity of HRECs induced by high glucose. The apoptosis of HRECs cultured under high glucose conditions was significantly inhibited (P<0.05), the levels of IL-6, IL-8, and TNF-α in the cell supernatant were significantly decreased (P<0.05), and the levels of IL-10 were significantly increased (P<0.05). Meanwhile, the relative mRNA expression levels of IL-6, IL-8, and TNF-α in HRECs were significantly decreased (P<0.05), while those of IL-10 were significantly increased (P<0.05). The activity of the high glucose-induced NOX4/NLRP3 pathway in HRECs was significantly inhibited after treatment with 15 µM of GA (P<0.05). Following activation of the NOX4/NLRP3 pathway in HRECs, the apoptosis level was significantly increased (P<0.05), and the inflammatory response was aggravated (P<0.05). Inhibiting the activity of the intracellular NOX4/NLRP3 pathway markedly inhibited cell apoptosis and the inflammatory response (P<0.05). Conclusions: GA can inhibit the apoptosis and inflammation of HRECs under high glucose conditions by inhibiting the activity of the NOX4/NLRP3 pathway. This has a significant inhibitory effect on diabetic retinopathy, which is worthy of further study.
RESUMEN
Objective: To investigate the protective effect of somatostatin (SS) on acute kidney injury (AKI) of paraquat (PQ) poisoned mice and its mechanism. Methods: From December 2017 to April 2018, a total of 48 SPF male BALB/C mice were selected and randomly divided into 4 groups, with 12 mice in each group: Control group, SS group (20 mg/kg SS was injected 1 hour before and 3 hours after gavage with normal saline) , PQ group (2% PQ 60 mg/kg by gavage) and PQ+SS group (Intragastric administration was performed with 2% PQ solution of 60 mg/kg, and 20 mg/kg SS was administered 1 h before and 3 h after intragastric administration) , 12 mice in each group were observed for the general situation and behavioral effects. After 24 hours of modeling, mice were sacrificed.Then blood was extracted after eyeball was removed, and both kidneys were removed by laparotomy. Serum IL-6, TNF-α and MPO levels were determined by ELISA. The characteristic pathological changes of toxic renal tubular injury were observed under light microscope and scored accordingly. The changes of NF-κB expression were detected by Western-Blot, SOD, Caspase-3 and malondialdehyde (MDA) were detected by chemical colorimetry. Results: Mice in Control group and SS group showed normal general conditions and behaviors; Mice in PQ group were significantly worse than those in Control group, showing decreased feeding and activity, dry fur, hair shedding and listless spirit; The above symptoms in the mice of PQ+SS group were alleviated compared with the PQ group. Under the light microscope, the renal tissue structure of PQ group was obviously disordered and severely damaged, and the nephropathy score was (6.14±0.72) . The performance of PQ+SS group under light microscope was improved compared with PQ group, and nephropathy score (4.36±0.42) decreased (P<0.05) . Compared with the Control group, serum TNF-α (39.89±3.32) pg/ml, IL-6 (77.29±4.77) pg/ml, renal NF-κB (2.29±0.097) , MPO (0.31±0.017) µg/ml, MDA (0.91±0.03) mmol/mg prot, and Caspase-3 (376.51±8.24) % levels were significantly increased in the PQ group, while the level of renal SOD (2.36±0.73) U/mg prot was significantly decreased (P<0.05) . Compared with the PQ group, serum TNF-α (33.82±1.57) pg/ml, IL-6 (58.49±5.89) pg/ml, renal NF-κB (0.84±0.05) , MPO (0.22±0.01) µg/ml, MDA (0.72±0.05) mmol/mg prot, Caspase-3 (327.32±21.93) % decreased significantly, and renal SOD (4.90±0.81) U/mg prot increased significantly in the PQ+SS group (P<0.05) . Conclusion: PQ poisoning can lead to AKI in mice, while SS can reduce AKI caused by PQ poisoning, improve the general survival state of PQ poisoned mice, and play a certain protective role in kidney injury caused by PQ poisoning, which may be achieved by inhibiting oxidative stress response, inflammatory response and apoptosis caused by poisoning.
Asunto(s)
Paraquat/toxicidad , Somatostatina/metabolismo , Animales , Riñón , Pulmón , Masculino , Ratones , Ratones Endogámicos BALB CRESUMEN
Aim To study the mechanism of DXM and NAC inhibiting the expression of IL-8 and ICAM-1 in A549 cells. Methods The expression of IL-8 and ICAM-1 was detected by ELISA and flow cytometry re-spectively; the expression of GR,HDAC,AP-1,NF-κB was detected by Western blot, while the activity of HDAC was detected by spectrophotometry. ResultsThe increasing expression of IL-8 and ICAM-1 induced by TNF-α could be inhibited by DXM and NAC in A549 cells. DXM could inhibit the transcribed activa-tion of AP-1,NF-κB, and the expression of HDAC and its activity induced by TNF-α and LPS; NAC only in-hibited the transcribed activation of NF-κB, while it had no affection on the transcribed activation of AP-1 and the expression of HDAC and its activity. Conclu-sions DXM and NAC both have the anti-inflammatory effect. DXM plays the role of anti-inflammation through increasing the expression and activation of HDAC, in-hibiting the transcribed activation of AP-1 and NF-κB, while NAC has no effect on the expression and activa-tion of HDAC, which shows that NAC does not exert anti-inflammatory effect through acetylation signal.