GPR124 induces NLRP3 inflammasome-mediated pyroptosis in endothelial cells during ischemic injury.

OBJECTIVE: G protein-coupled receptor 124 (GPR124) regulates central nervous system angiogenesis and blood-brain barrier (BBB) integrity, and its deficiency aggravates BBB breakdown and hemorrhagic transformation in ischemic mice. However, excessive GPR124 expression promotes inflammation in atherosclerotic mice. In this study, we aimed to elucidate the role of GPR124 in hypoxia/ischemia-induced cerebrovascular endothelial cell injury. METHODS: bEnd.3 cells were exposed to oxygen-glucose deprivation (OGD), and time-dependent changes in GPR124 mRNA and protein expression were evaluated using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting. The effects of GPR124 overexpression or knockdown on the expression of pyroptosis-related genes were assessed at the mRNA and protein levels. Tadehaginoside (TA) was screened as a potential small molecule targeting GPR124, and its effects on pyroptosis-related signaling pathways were investigated. Finally, the therapeutic efficacy of TA was evaluated using a rat model of transient middle cerebral artery occlusion/reperfusion (tMCAO/R). RESULTS: During OGD, the expression of GPR124 initially increased and then decreased over time, with the highest levels observed 1 h after OGD. The overexpression of GPR124 enhanced the OGD-induced expression of NLRP3, Caspase-1, and Gasdermin D (GSDMD) in bEnd.3 cells, whereas GPR124 knockdown reduced pyroptosis. Additionally, TA exhibited a high targeting ability to GPR124, significantly inhibiting its function and expression and suppressing the expression of pyroptosis-related proteins during OGD. Furthermore, TA treatment significantly reduced the cerebral infarct volume and pyroptotic signaling in tMCAO/R rats. CONCLUSIONS: Our findings suggest that GPR124 mediates pyroptotic signaling in endothelial cells during the early stages of hypoxia/ischemia, thereby exacerbating ischemic injury.

Effects of Stephania hainanensis alkaloids on MSU-induced acute gouty arthritis in mice.

BACKGROUND: Gout is initiated by the precipitation of monosodium urate (MSU) crystals within the joints and soft tissues, and it can eventually cause acute or chronic arthritis. MSU crystals trigger, amplify, and maintain a strong inflammatory response through promoting proinflammatory activity. In this study, the therapeutic effects of Stephania hainanensis (S. hainanensis) total alkaloid (SHA) were tested and evaluated on MSU-induced acute gouty arthritis in a mouse model. METHODS: After oral administration of SHA (10 or 20 mg/kg) or the antigout medicine colchicine (0.5 mg/kg) once daily for 3 consecutive days, MSU crystals suspended in saline (2.5 mg/50 µl) were intradermally injected into the right paw of the mice. Then, SHA and colchicine were administered for another 2 days. During this period, swelling of the ankle and clinical scores were measured at 12, 24, and 48 h postinjection. After the mice were euthanized, inflammatory cytokine expression and paw tissue inflammation-related gene and protein expression, and a histopathological analysis was performed. RESULTS: SHA had obvious therapeutic effects on MSU-induced acute gouty arthritis in mice. SHA alleviated ankle swelling and inhibited the production of cytokines, such as IL-1ß and TNF-α. In addition, NLRP3, Caspase-1 and IL-1ß, which are activated by MSU were also suppressed by SHA. The histological evaluation showed that SHA relieved the infiltration of inflammation around the ankle. CONCLUSIONS: These results suggest that SHA is capable of anti-inflammatory activities and may be useful for treating gouty arthritis.

Polysaccharide from Artocarpus heterophyllus Lam. (jackfruit) pulp modulates gut microbiota composition and improves short-chain fatty acids production.

This study aimed to investigate the effects of polysaccharide from Artocarpus heterophyllus Lam. pulp (JFP-Ps) on gut microbiota composition and short-chain fatty acids production in mice. The microbial communities of V3 and V4 region 16S rRNA gene was amplified by PCR, then sequenced on an Illumina MiSeq PE250 platform and analyzed by multivariate statistical methods. The concentrations of short-chain fatty acids (SCFAs) were measured using gas chromatography (GC) equipped with a flame ionization detector (FID). The results showed that JFP-Ps significantly affected the levels of intestinal bacteria, including Bacteroidetes, Firmicutes, Proteobacteria, Cyanobacteria, Actinobacteria, Tenericutes, Deferribacteres and TM7. The concentrations of acetic acid, propionic acid, n-butyric acid and total SCFAs in mouse feces were significantly increased by treatment with JFP-Ps for 2 weeks. These results indicate that JFP-Ps is beneficial to the gut health and can be developed as a functional ingredient in relation to gut health.

A sea cucumber (Holothuria leucospilota) polysaccharide improves the gut microbiome to alleviate the symptoms of type 2 diabetes mellitus in Goto-Kakizaki rats.

Diabetes mellitus has become a worldwide concern in recent years. In this study, the effect of Holothuria leucospilota polysaccharide (HLP) on type 2 diabetes mellitus (T2DM) was investigated in Goto-Kakizaki (GK) rats. The results showed that HLP significantly improved glucose intolerance and regulated blood lipid and hormone levels (p < 0.05). Pathological analysis showed that HLP repaired the impairments of the pancreas and colon in diabetic rats. In addition, a high dose of HLP (200 mg/kg) significantly upregulated the gene expression of peroxisome proliferator-activated receptor-α (PPAR-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), phosphoinositide 3-kinase (PI3K), protein kinase B (PKB/AKT), glucose transporter-4 (GLUT4) and anti-apoptotic (Bcl-2), and downregulated the mRNA levels of pro-apoptotic (Bax) and cluster of differentiation 36 (CD36) in diabetic rats (p < 0.05). Furthermore, HLP treatment increased the short-chain fatty acid-producing bacteria and decreased the opportunistic bacterial pathogen in the feces of diabetic rats. These results demonstrated that HLP has the potential to ameliorate T2DM in GK rats.

MicroRNA-9 overexpression suppresses vulnerable atherosclerotic plaque and enhances vascular remodeling through negative regulation of the p38MAPK pathway via OLR1 in acute coronary syndrome.

Acute coronary syndrome (ACS) is characterized by atherosclerotic plaque rupture with a high incidence of recurrent ischemic events. Several microRNAs are found to be aberrantly expressed in atherosclerotic plaques. This study aims to investigate the effects of microRNA-9 (miR-9) on vulnerable atherosclerotic plaque and vascular remodeling in ACS and underlying mechanisms. Microarray-based gene expression profiling was used to identify differentially expressed genes related to ACS and regulatory miRNAs. Oxidized low-density lipoprotein (lectin-like) receptor 1 (OLR1) was identified to be aberrantly activated in ACS and regulated by miR-9. OLR1 was verified as a target gene of miR-9 by bioinformatics prediction and dual luciferase reporter gene assay. The atherosclerotic models were induced in ApoE-/- mice, in which the agomir or antagomir of miR-9, or small interfering RNA (siRNA) against OLR1 were separately introduced. Serum lipid levels and expression of vascular remodeling and inflammatory response-related factors were determined, respectively. On the basis of the obtained results, in the atherosclerosis mice treated with the agomir of miR-9 and siRNA against OLR1, the p38-mitogen-activated protein kinase (p38MAPK) pathway was inhibited; levels of triglyceride, total cholesterol, low-density lipoprotein cholesterol, tumor necrosis factor-α, interleukin-6, and vascular endothelial growth factor were reduced, but the high-density lipoprotein cholesterol level was increased, along with decreased vulnerable atherosclerotic plaque area and enhanced vascular remodeling. Taken together, these findings suggested an inhibitory role miR-9 acts in the formation of vulnerable atherosclerotic plaques in ACS mice, along with a promoted vascular remodeling, via a negative feedback regulation of OLR1-mediated p38MAPK pathway.

Multimodal Rehabilitation Program Promotes Motor Function Recovery of Rats After Ischemic Stroke by Upregulating Expressions of GAP-43, SYN, HSP70, and C-MYC.

BACKGROUND: Despite the intense efforts devoted to preventing and treating cerebral ischemia, some individuals will continue to have completed infarctions. Failure of prevention or intervention does not, however, preclude therapeutic approaches to enhance recovery. Our study aims to explore the effect of multimodal rehabilitation program on the motor function recovery of rats with ischemic stroke. METHODS: Rat models of ischemic stroke were established using clean-grade adult male Sprague-Dawley rats. Motor function of rats was scored by the Bederson neurological function, balance beam test, and screen test. Nissl staining was conducted for morphological and structural changes of nerve cells in the arteriae cerebri anterior zone. Immunohistochemistry was applied to detect the expressions of growth-associated protein (GAP-43), synaptophysin (SYN) and Caspase-3, terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) staining was carried out in the corpus striatum 21 days after operation; reverse transcription quantitative polymerase chain reaction and Western blot analysis were conducted for testing messager RNA (mRNA) and protein expressions of heat shock protein 70 (Hsp70) and MYC proto-oncogene (c-Myc). RESULTS: Rats receiving multimodal rehabilitation program had lower Bederson neurological function, balance beam, and screen test scores on the 7th, 14th and 21st days after operation; more number of neurons surviving in the arteriae cerebri anterior zone at each time point after operation, higher GAP-43 expression on the 7th and 14th days after operation, and higher SYN expression on the 14th and 21st days after operation, on the 7th, 14th and 21st days after operation, higher mRNA and protein expressions of HSP70 and C-MYC, lower Caspase-3 positive expression and TUNEL positive stained cells. CONCLUSIONS: Multimodal rehabilitation program could promote motor function recovery of rats after ischemic stroke by upregulating GAP-43 and SYN expressions at arteriae cerebri anterior zone and upregulating HSP70 and C-MYC expressions in the brain tissues.

l-Homocarnosine attenuates inflammation in cerebral ischemia-reperfusion injury through inhibition of nod-like receptor protein 3 inflammasome.

We investigated the therapeutic effects of l-homocarnosine against inflammation in a rat model of cerebral ischemia-reperfusion injury. Rats were grouped into control, middle cerebral artery occlusion (MCAO), 0.5 mM l-homocarnosine + MCAO, and 1 mM l-homocarnosine + MCAO treatment groups. Superoxide dismutase (SOD), glutathione peroxidase (Gpx), catalase, lipid peroxidation, and reduced glutathione (GSH) levels were measured. Neurological scores were assessed, and histopathology, scanning electron microscopy (SEM), and fluorescence microscopy analyses were conducted. The mRNA expression levels of nod-like receptor protein 3 (NLRP3), tumor necrosis factor alpha (TNF-α), and interleukin-6 (IL-6) and protein expression levels of NLRP3 were assessed. l-Homocarnosine supplementation substantially increased SOD, catalase, Gpx, and GSH levels, whereas it reduced the levels of lipid peroxidation relative to MCAO rats. l-Homocarnosine significantly reduced the infarct area and neurological deficit score, as well as histopathological alteration, apoptosis, and necrosis in brain tissue. The mRNA expression levels of NLRP3, TNF-α, and IL-6 were increased in MCAO rats, whereas l-homocarnosine supplementation reduced mRNA expression by >40%, and NLRP3 protein expression was reduced by >30% in 1 mM l-homocarnosine-treated MCAO rats. We propose that l-homocarnosine exerts a protective effect in cerebral ischemia-reperfusion injury-induced rats by downregulating NLRP3 expression.