ABSTRACT
ObjectiveTo investigate the effects and mechanism of Zuogui Jiangtang Tongmai prescription （ZJTP） on human umbilical vein endothelial cells （HUVECs） damaged by high glucose combined with lipopolysaccharide （LPS）. MethodThe survival rate of cells was determined by cell counting kit-8 （CCK-8）， and the level of tumor necrosis factor-α （TNF-α） was determined by enzyme-linked immunosorbent assay （ELISA） to determine the optimal injury concentration and action time of LPS， as well as the optimal action concentration of ZJTP drug-containing serum. HUVECs were divided into a blank control group， a model group， a ZJTP drug-containing serum group， and an SCFA mixed liquid group. ELISA was used to detect the level of endothelin-1 （ET-1）， nitric oxide （NO）， interleukin-1β （IL-1β）， interleukin-6 （IL-6）， and TNF-α. Western blot was performed to detect the protein expression of G protein-coupled receptor43 （GPR43）， β-suppressor protein-2 （β-arrestin-2）， nuclear factor-κB suppressor α （IκBα）， and nuclear factor κB p65 （NF-κB p65）. The nucleation of NF-κB p65 was observed by immunofluorescence staining （IF）. The role of GPR43 in the regulation of inflammatory injury was observed by means of small interfering ribonucleic acid （siRNA）. The cells after intervention were divided into an empty carrier group， a ZJTP drug-containing serum group， a Si-GPR43 group， and a Si-GPR43 + ZJTP drug-containing serum group. The content of IL-1β， IL-6， and TNF-α was detected by ELISA. The protein expression of pathways was detected by Western blot. IF was used to observe the nucleation of NF-κB p65. ResultThe optimal molding condition was 1 mg·L-1 LPS for 24 h. The optimal drug intervention condition was 5% ZJTP drug-containing serum for 24 h. Compared with the blank control group， the content of ET-1 in the model group was significantly increased， and the content of NO was significantly decreased （P<0.01）. The levels of inflammatory factors were significantly increased （P<0.01）. The expressions of GPR43 and IκBα were significantly decreased， while the protein expressions of β-arrestin-2 and NF-κB p65 were significantly increased （P<0.01）. NF-κB p65 protein was transferred from the extranuclear to the intranuclear （P<0.01）. Compared with the model group， the content of ET-1 in the ZJTP drug-containing serum group was decreased， and the content of NO was increased （P<0.05）. The levels of inflammatory factors decreased （P<0.05）. The protein expressions of GPR43 and IκBα were increased， while the expressions of β-arrestin-2 and NF-κB p65 were decreased （P<0.05）. The amount of NF-κB p65 transferred from the intranuclear to the extranuclear decreased （P<0.01）. The mechanism study showed that compared with the Si-GPR43 group， the content of IL-1β， IL-6， and TNF-α were significantly decreased after treatment with ZJTP drug-containing serum （P<0.01）. The protein expressions of GPR43 and IκBα were significantly increased （P<0.01）， while the protein expressions of β-arrestin-2 and NF-κB p65 were significantly decreased （P<0.01）. The amount of NF-κB p65 transferred from the extranuclear to the intranuclear decreased （P<0.01）. ConclusionZJTP has a protective effect on HUVECs with high glucose and LPS-induced inflammatory injury， which may be related to the regulation of GPR43/β-arrestin-2/IκBα/NF-κB pathway.
ABSTRACT
ObjectiveTo explore the potential mechanism of Zuogui Jiangtang Tongmai prescription （ZJT） in the treatment of diabetes mellitus complicated with cerebral infarction （DM-CI） in rats based on the short-chain fatty acids （SCFAs）/G protein-coupled receptor 43 （GPR43）/glucagon-like peptide-1 （GLP-1）/GLP-1 receptor （GLP-1R） signaling pathway. MethodSixty SD rats were randomly divided into sham operation group， model group， low- and high-dose ZJT groups （12， 24 g·kg-1）， western medicine group （140 mg·kg-1 pioglitazone metformin tablets + 27 mg·kg-1 enteric-coated aspirin tablets）. Except for the sham operation group， all other groups were fed a high-sugar high-fat diet for 4 weeks and then subjected to intraperitoneal injection of 1% streptozotocin at 35 mg·kg-1 combined with middle cerebral artery occlusion （MCAO） to establish a DM-CI rat model. The corresponding interventions were performed with distilled water， low-dose ZJT， high-dose ZJT， pioglitazone metformin tablets， and enteric-coated aspirin tablets. After surgery， National Institutes of Health Stroke Scale （NIHSS） scoring and triphenyltetrazolium chloride （TTC） staining to measure the rat's cerebral infarct volume were carried out. Random blood glucose levels were measured， and hematoxylin-eosin （HE） staining was used to observe histopathological changes in rat brain tissues. Gas chromatography was employed to detect the content of SCFAs in the cecum contents. Enzyme-linked immunosorbent assay （ELISA） was adopted to measure serum GLP-1 level. Western blot was used to detect the protein expression of GPR43 in rat ileal tissues and GLP-1R in the ischemic brain tissues. ResultCompared with the sham operation group， the model group showed significantly increased NIHSS scores， random blood glucose levels， and cerebral infarct volumes （P<0.01）， and significantly decreased SCFAs content， GLP-1 levels， and GPR43 and GLP-1R protein expression （P<0.01）. Compared with the model group， the high-dose ZJT group and the western medicine group exhibited significantly reduced NIHSS scores， random blood glucose levels， and cerebral infarct volumes （P<0.05， P<0.01）， and significantly increased SCFAs content， GLP-1 levels， and GPR43 and GLP-1R protein expression （P<0.01）. ConclusionZJT can improve glucose metabolism disorder and reduce neurological damage in DM-CI rats， and its mechanism may be related to the increase in SCFAs content and the upregulation of the GPR43/GLP-1/GLP-1R signaling pathway.