This study was carried out to test the hypothesis that Tongxinluo (TXL) as a Chinese herbal medicine enhances stability of vulnerable plaque dose dependently via lipid-lowering and anti-inflammation effects, similar to a high-dose simvastatin therapy. After abdominal aortic balloon injury, 75 rabbits were fed a 1% cholesterol diet for 10 wk and were then divided into five groups for 8-wk treatment: control group, low-dose TXL group, moderate-dose TXL group, high-dose TXL group, and high-dose simvastatin group. At the end of week 16, an adenovirus containing p53 was injected into the abdominal aortic plaques. Two weeks later, plaque rupture was induced by pharmacological triggering. The incidence of plaque rupture in all treatment groups (14.3%, 7.1%, 7.7%, and 7.1%) was significantly lower than that in control group (73.3%; P>0.01). TXL dose-dependently lowered serum lipid levels and inhibited systemic inflammation. Corrected acoustic intensity and fibrous cap thickness of the aortic plaques were significantly increased, whereas plaque area, plaque burden, vulnerable index, and expression of oxidized low-density lipoprotein (ox-LDL) receptor 1, matrix metalloproteinase 1 (MMP-1), MMP-3, tissue inhibitor of MMP 1, and NF-kappaB in plaques were markedly reduced in all treatment groups when compared with the control group. Similar to high-dose simvastatin group, high-dose TXL group exhibited a low serum level of low-density lipoprotein cholesterol and ox-LDL, a low expression level of systemic and local inflammatory factors and a low plaque vulnerability index, with no differences in the incidence of plaque rupture among all treatment groups. TXL dose-dependently enhances the stability of vulnerable plaques and prevents plaques from rupture. Simvastatin and TXL offer similar protection in terms of lipid-lowering, anti-inflammation, and antioxidation effects.
The reduced expression of angiotensin-converting enzyme (ACE) 2 in the kidneys of animal models and patients with diabetes suggests ACE2 involvement in diabetic nephrology. To explore the renoprotective effects of ACE2 overexpression, ACE inhibition (ACEI) or both on diabetic nephropathy and the potential mechanisms involved, 50 Wistar rats were randomly divided into a normal group that received an injection of sodium citrate buffer and a diabetic model group that received an injection of 60 mg/kg streptozotocin. Eight wks after streptozotocin injection, the diabetic rats were divided into no treatment group, adenoviral (Ad)-ACE2 group, Ad-green flurescent protein (GFP) group, ACEI group receiving benazepril and Ad-ACE2 + ACEI group. Four wks after treatment, physical, biochemical, and renal functional and morphological parameters were measured. An experiment in cultured glomerular mesangial cells was performed to examine the effects of ACE2 on cellular proliferation, oxidative stress and collagen IV synthesis. In comparison with the Ad-GFP group, the Ad-ACE2 group exhibited reduced systolic blood pressure, urinary albumin excretion, creatinine clearance, glomeruli sclerosis index and renal malondialdehyde level; downregulated transforming growth factor (TGF)-β1, vascular endothelial growth factor (VEGF) and collagen IV protein expression; and increased renal superoxide dismutase activity. Ad-ACE2 and ACEI had similar effects, whereas combined use of Ad-ACE2 and ACEI offered no additional benefits. ACE2 transfection attenuated angiotensin (Ang) II-induced glomerular mesangial cell proliferation, oxidative stress and collagen IV protein synthesis. In conclusion, ACE2 exerts a renoprotective effect similar to that of ACEI treatment. Decreased renal Ang II, increased renal Ang-(1-7) levels, and inhibited oxidative stress were the possible mechanisms involved.
In nonobese spontaneously diabetic rats, IT is equivalent to MDJB in terms of glucose control and weight secondary to significant increases of GLP-1. IT is faster to perform and yields a shorter recovery period than does MDJB.
This study aimed to investigate the association of the aldehyde dehydrogenase 2 (ALDH2) Glu504Lys polymorphism, which exists in 30–50% of East Asians, and risk of acute coronary syndrome (ACS). We enrolled 1092 unrelated Han Chinese, including 546 with ACS and 546 age- and sex-matched controls. Subjects with ALDH2 mutant genotypes showed significantly higher ACS than did controls (46.7% versus 31.9%, P < 0.001). Logistic regression analysis revealed the ALDH2 mutant independently associated with ACS (odds ratio [OR] 1.95, 95% confidence interval [CI]: 1.31–2.92, P = 0.001), but the association was weaker on adjusting for alcohol consumption (OR 1.82, 95% CI: 1.23–2.70, P = 0.003). Similar results were found in a subgroup analysis of patients with primary ST-segment elevation myocardial infarction (STEMI). The ALDH2 mutant was significantly associated with level of high-sensitivity C-reactive protein (hs-CRP) in patients with ACS (P = 0.002) and in controls (P = 0.009) and number of circulating endothelial progenitor cells (EPCs) (P = 0.032); furthermore, inclusion of hs-CRP level and EPCs number as independent variables in regression analysis reduced the importance of ALDH2 polymorphism in ACS or primary STEMI. However, ALDH2 polymorphism was not associated with number of coronary arteries with significant stenosis, Gensini score or flow-mediated dilation of the brachial artery. Our results suggest that ALDH2 mutation is a genetic risk marker for ACS, which is explained in part by alcohol consumption, inflammation and number of circulating EPCs.
Background: Clinical trials and animal studies have shown that sodium-glucose co-transporter type 2 (SGLT2) inhibitors improve pancreatic beta cell function. Our study aimed to investigate the effect of dapagliflozin on islet morphology and cell phenotype, and explore the origin and possible reason of the regenerated beta cells. Methods: Two diabetic mouse models, db/db mice and pancreatic alpha cell lineage-tracing (glucagon-β-gal) mice whose diabetes was induced by high fat diet combined with streptozotocin, were used. Mice were treated by daily intragastric administration of dapagliflozin (1 mg/kg) or vehicle for 6 weeks. The plasma insulin, glucagon and glucagon-like peptide-1 (GLP-1) were determined by using ELISA. The evaluation of islet morphology and cell phenotype was performed with immunofluorescence. Primary rodent islets and αTC1.9, a mouse alpha cell line, were incubated with dapagliflozin (0.25-25 μmol/L) or vehicle in the presence or absence of GLP-1 receptor antagonist for 24 h in regular or high glucose medium. The expression of specific markers and hormone levels were determined. Results: Treatment with dapagliflozin significantly decreased blood glucose in the two diabetic models and upregulated plasma insulin and GLP-1 levels in db/db mice. The dapagliflozin treatment increased islet and beta cell numbers in the two diabetic mice. The beta cell proliferation as indicated by C-peptide and BrdU doublepositive cells was boosted by dapagliflozin. The alpha to beta cell conversion, as evaluated by glucagon and insulin double-positive cells and confirmed by using alpha cell lineage-tracing, was facilitated by dapagliflozin. After the dapagliflozin treatment, some insulin-positive cells were located in the duct compartment or even colocalized with duct cell markers, suggestive of duct-derived beta cell neogenesis. In cultured primary rodent islets and αTC1.9 cells, dapagliflozin upregulated the expression of pancreatic endocrine progenitor and beta cell specific markers (including Pdx1) under high glucose condition. Moreover, dapagliflozin upregulated the expression of Pcsk1 (which encodes prohormone convertase 1/3, an important enzyme for processing proglucagon to GLP-1), and increased GLP-1 content and secretion in αTC1.9 cells. Importantly, the dapagliflozin-induced upregulation of Pdx1 expression was attenuated by GLP-1 receptor antagonist. Conclusions: Except for glucose-lowering effect, dapagliflozin has extra protective effects on beta cells in type 2 diabetes. Dapagliflozin enhances beta cell self-replication, induces alpha to beta cell conversion, and promotes duct-derived beta cell neogenesis. The promoting effects of dapagliflozin on beta cell regeneration may be partially mediated via GLP-1 secreted from alpha cells.
Background:Quercetin has been shown to induce apoptosis in a number of cancer cell lines, but a quercetin-loaded nanoliposomal formulation with enhanced antitumor activity in C6 glioma cells and its effect on cancer cell death has not been well studied. The aim of this study was to examine if quercetin-loaded liposomes (QUE-NL) has enhanced cytotoxic effects and if such effects involve type III programmed cell death in C6 glioma cells. Methods: C6 glioma cells were treated with QUE-NL and assayed for cell survival, apoptosis, and necrosis. Levels of reactive oxygen species production and loss of mitochondrial membrane potential (∆Ψm) were also determined by flow cytometry assay to assess the effects of QUE-NL. ATP levels and lactate dehydrogenase activity were measured, and Western blotting was used to assay cytochrome C release and caspase expression. Results: QUE-NL induced type III (necrotic) programmed cell death in C6 glioma cells in a dose-dependent and time-dependent manner. High concentrations of QUE-NL induced cell necrosis, which is distinct from apoptosis and autophagy, whereas liposomes administered alone induced neither significant apoptosis nor necrosis in C6 glioma cells. QUE-NL-induced ∆Ψm loss and cytochrome C release had no effect on caspase activation, but decreased ATP levels and increased lactate dehydrogenase activity indicated that QUE-NL stimulated necrotic cell death. Conclusion: C6 glioma cells treated with QUE-NL showed a cellular pattern associated with necrosis without apoptosis and was independent of caspase activity. Nonapoptotic cell death induced by high concentrations of QUE-NL for controlling caspase-independent type III programmed cell death may provide the basis for novel therapeutic approaches to overcome avoidance of apoptosis by malignant cells.
Objective-We investigated whether Smad, mitogen-activated protein kinase (MAPK), and integrin signaling pathways cross-talk to enhance adventitial fibroblast (AF) bioactivity, which was activated by transforming growth factor (TGF)-1 and inhibited by Gax. Methods and Results-Cultured AFs were stimulated with Ad-Gax, TGF-1, and siRNA-Gax. Assays for AFs viabilities demonstrated that TGF-1 and siRNA-Gax enhanced AFs proliferative, migratory, and adherent abilities, whereas Gax counteracted TGF-1-activated actions. Flow cytometry revealed that TGF-1 and siRNA-Gax increased S phase cells; however, Gax decreased AFs in the S phase and increased those in the G0-G1 and apoptotic phases. RT-PCR, Western blotting, and immunocytochemistry showed that TGF-1 and siRNA-Gax upregulated the expression of cytokines in Smad, MAPK, and integrin signaling pathways, and downregulated that of p15, p16, and p21. Conversely, Gax induced downregulation of these cytokines and upregulation of p15, p16, and p21. Thus, these signaling pathways cross-talk to enhance AF bioactivity; Gax effectively counteracts TGF-1 effects, blocks the cross-talk of these pathways, inhibits AF functions, and increases AF apoptosis. Conclusions-Our findings indicate that cross-talk among Smad, MAPK, and integrin signaling pathways may account mainly for the mechanism of AF functions. Gax is a promising therapeutic gene for dissecting the signaling pathways controlling AF bioactivities. Key Words: adventitial fibroblast Ⅲ signaling pathway Ⅲ cell function Ⅲ TGF-1 Ⅲ Gax P reviously, vascular intima and media were emphasized in research into vascular proliferation such as vascular restenosis and atherosclerosis. Recent studies, however, have revealed that vascular intimal proliferation is not only caused by the intima injury but also produced by the intervention in vascular adventitia. AF, as the major cell component in vascular adventitia, can respond to diverse stimulation and result in vascular stenosis by proliferation, migration, phenotype transformation, adhesion, cytokine excretion, and epimatrix formation after activation. 1,2 Transforming growth factor (TGF)-1 is an important pleiotropic cytokine with powerful effects on fibroblast bioactivity and is closely associated with vascular adventitial remodeling. 3,4 TGF-1 can accelerate AF proliferation and induce transdifferentiation of AF into myofibroblast, which is involved in vascular restenotic lesions by modulating mesenchymal cells growth, augmenting extracellular matrix (ECM) proteins synthesis, and facilitating neointima formation. Conversely, anti-TGF-1 inhibited AF proliferation and harmful vascular remodeling. TGF-1 can activate the Smad pathway, as well as other signaling pathways such as MAPK and integrin pathways, and induce cross-talk between the Smad pathway and other signaling pathways in some kinds of cells. [5][6][7][8] However, the mechanism of TGF-1 regulating AF bioactivity remains unclear.Vascular remodeling occurs during normal angiogenesis and in various pathological st...
Background: Spinal degenerative diseases are a major health problem and social burden worldwide. Intervertebral disc degeneration (IDD) is the pathological basis of spinal degenerative diseases and is characterized by loss of nucleus pulposus cells due to excessive apoptosis caused by various factors. MicroRNAs (miRNAs) have been reported to be functionally involved in the control of apoptosis. Methods: computational analysis and luciferase assay were used to identify the target of miR-125a, and cell culture, transfection were used to confirm such relationship. Sequencing was used to determine the genotype of each participant. Results: We confirmed the previous report that the presence of the minor allele (T) of rs12976445 polymorphism significantly downregulated the expression level of miR-125a in nucleus pulposus cells, leading to less efficient inhibition of its target gene. We also validated TP53INP1 as a target of miR-125a in nucleus pulposus cells using a dual luciferase reporter system, and the transfection of miR-125a significantly reduced the expression of TP53INP1. The expression level of TP53INP1 was significantly lower in nucleus pulposus cells genotyped as CT or TT than in those genotyped as CC, and the apoptosis rate was consistently lower in the CC group than in the nucleus pulposus cells collected from individuals carrying at least one minor allele of rs12976445 polymorphism. To study the association between rs12976445 polymorphism and the risk of IDD, we enrolled 242 patients diagnosed with IDD and 278 normal controls, and significant differences were noted regarding the genotype distribution of rs12976445 between the IDD and the control groups (OR = 2.69, 95% C.I. = 1.88-3.83, p < 0.0001). In summary, rs12976445 polymorphism is significantly associated with the risk of IDD in the Chinese population. Conclusion: The present study indicated that miR-125a is a promising potential target for patients with IDD in clinical practice.
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