ß­aminoisobutyric acid ameliorates hypertensive vascular remodeling via activating the AMPK/SIRT1 pathway in VSMCs.

Excessive proliferation and migration of vascular smooth muscle cells (VSMCs) play a fundamental role in the pathogenesis of hypertension-related vascular remodeling. ß-aminoisobutyric acid (BAIBA) is a nonprotein ß-amino acid with multiple pharmacological actions. Recently, BAIBA has been shown to attenuate salt­sensitive hypertension, but the role of BAIBA in hypertension-related vascular remodeling has yet to be fully clarified. This study examined the potential roles and underlying mechanisms of BAIBA in VSMC proliferation and migration induced by hypertension. Primary VSMCs were cultured from the aortas of Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHR). Our results showed that BAIBA pretreatment obviously alleviated the phenotypic transformation, proliferation, and migration of SHR-derived VSMCs. Exogenous BAIBA significantly inhibited the release of inflammatory cytokines by diminishing phosphorylation and nuclear translocation of p65 NFκB, retarding IκBα phosphorylation and degradation, as well as erasing STAT3 phosphorylation in VSMCs. Supplementation of BAIBA triggered Nrf2 dissociation from Keap1 and inhibited oxidative stress in VSMCs from SHR. Mechanistically, activation of the AMPK/sirtuin 1 (SIRT1) axis was required for BAIBA to cube hypertension-induced VSMC proliferation, migration, oxidative damage and inflammatory response. Most importantly, exogenous BAIBA alleviated hypertension, ameliorated vascular remodeling and fibrosis, abated vascular oxidative burst and inflammation in SHR, an effect that was abolished by deficiency of AMPKα1 and SIRT1. BAIBA might serve as a novel therapeutic agent to prevent vascular remodeling in the context of hypertension.

Ginsenoside Rg1 attenuates mechanical stress-induced cardiac injury via calcium sensing receptor-related pathway.

BACKGROUND: Ginsenoside Rg1 (Rg1) has been well documented to be effective against various cardiovascular disease. The aim of this study is to evaluate the effect of Rg1 on mechanical stress-induced cardiac injury and its possible mechanism with a focus on the calcium sensing receptor (CaSR) signaling pathway. METHODS: Mechanical stress was implemented on rats through abdominal aortic constriction (AAC) procedure and on cardiomyocytes and cardiac fibroblasts by mechanical stretching with Bioflex Collagen I plates. The effects of Rg1 on cell hypertrophy, fibrosis, cardiac function, [Ca2+]i, and the expression of CaSR and calcineurin (CaN) were assayed both on rat and cellular level. RESULTS: Rg1 alleviated cardiac hypertrophy and fibrosis, and improved cardiac decompensation induced by AAC in rat myocardial tissue and cultured cardiomyocytes and cardiac fibroblasts. Importantly, Rg1 treatment inhibited CaSR expression and increase of [Ca2+]i, which similar to the CaSR inhibitor NPS2143. In addition, Rg1 treatment inhibited CaN and TGF-ß1 pathways activation. Mechanistic analysis showed that the CaSR agonist GdCl3 could not further increase the [Ca2+]i and CaN pathway related protein expression induced by mechanical stretching in cultured cardiomyocytes. CsA, an inhibitor of CaN, inhibited cardiac hypertrophy, cardiac fibrosis, [Ca2+]i and CaN signaling but had no effect on CaSR expression. CONCLUSION: The activation of CaN pathway and the increase of [Ca2+]i mediated by CaSR are involved in cardiac hypertrophy and fibrosis, that may be the target of cardioprotection of Rg1 against myocardial injury.

Astragaloside IV attenuates myocardial ischemia/reperfusion injury in rats via inhibition of calcium-sensing receptor-mediated apoptotic signaling pathways.

Astragaloside IV (AsIV) is an active saponin extracted from Astragalus membranaceus, which has shown cardioprotective effects in a number of experimental animals. In this study we investigated the molecular mechanisms by which AsIV attenuated the myocardial ischemia reperfusion (MI/R)-induced injury in vitro and in vivo by focusing on calcium-sensing receptor (CaSR) and extracellular signal-regulated kinase 1/2 (ERK1/2). Rat neonatal cardiac myocytes were subjected to a hypoxia/reoxygenation (H/R) procedure in vitro, which significantly decreased the cell viability, increased lactate dehydrogenase (LDH) release, induced cardiomyocyte apoptosis, and increased [Ca2+]i. H/R also increased the expression of CaSR and decreased ERK1/2 phosphorylation levels in H/R-exposed myocytes. Pretreatment with AsIV (60 µmol/L) significantly improved the cell viability and decreased LDH release, attenuated myocyte apoptosis, decreased [Ca2+]i and CaSR expression, and increased the ERK1/2 phosphorylation levels. The protective effects of AsIV against H/R injury were partially inhibited by co-treatment with a CaSR agonist, gadolinium chloride (GdCl3) or with a specific ERK1/2 inhibitor U0126. For in vivo studies, a rat MI/R model was established. Pre-administration of AsIV (80 mg/kg every day, ig) significantly decreased the myocardium infarct size, creatine kinase-MB (CK-MB) production, serum cardiac troponin (cTnI) levels, and cardiomyocyte apoptosis in the rats with MI/R injury. The therapeutic effects of AsIV were associated with the downregulation of CaSR expression and upregulation of ERK1/2 phosphorylation in myocardial tissues. In summary, astragaloside IV attenuates myocardial I/R injury via inhibition of CaSR/ERK1/2 and the related apoptotic signaling pathways.

Vibration exercise decreases insulin resistance and modulates the insulin signaling pathway in a type 2 diabetic rat model.

Vibration exercise (VE) is a new type of physical training, but little is known about its effects on insulin resistance at the molecular level. A Sprague-Dawley rat model of type 2 diabetes with insulin resistance was induced with a high-fat diet and low-dose streptozotocin. Animals were then subjected to 8 wk of VE consisting of placing the rats on a vibration stand bracket (8 cm × 8 cm × 20 cm) with a maximum vertical vibration displacement of 52 mm for 15 min twice a day, 6 d each week. Various metabolic markers and the phosphorylation and expression of proteins within the PI3K/AKT insulin signaling pathway were assessed. The high-fat diet and low-dose streptozotocin increased food intake, body weight, and levels of blood glucose, triglycerides, total cholesterol, and free fatty acids, while Kitt rate, 2-deoxyglucose uptake, and glycogen levels were decreased. These effects were ameliorated in animals receiving VE. VE treatment activated the PI3K/AKT insulin-signaling pathway, and also increased the expression of GLUT4. In conclusion, VE improved the metabolic issues associated with the diabetic state by suppressing the reduction of IRS1, AKT2, and GLUT4 in the diabetic condition, indicating that VE could be used as a therapeutic intervention for insulin resistance and type 2 diabetes.

HIF-1α polymorphism in the susceptibility of cervical spondylotic myelopathy and its outcome after anterior cervical corpectomy and fusion treatment.

BACKGROUND: To investigate the association between the single nucleotide polymorphism (SNP) of hypoxia-inducible factor1 α (HIF-1α) and the susceptibility to cervical spondylotic myelopathy (CSM) and its outcome after surgical treatment. METHOD: A total of 230 CSM patients and 284 healthy controls were recruited. All patients received anterior cervical corpectomy and fusion (ACF) and were followed for 12 months. The genotypes for two HIF-1α variants (1772C>T and 1790G>A) were determined. RESULTS: In the present study, we found that the HIF-1α polymorphism at 1790G>A significantly affects the susceptibility to CSM and its clinical features, including severity and onset age. In addition, the 1790A>G polymorphism also determines the prognosis of CSM patients after ACF treatment. The GG genotype of 1790G>A polymorphism is associated with a higher risk to develop CSM, higher severity and earlier onset age. More importantly, we found that the 1790G>A polymorphism determines the clinical outcome in CSM patients who underwent ACF treatment. CONCLUSION: Our findings suggest that the HIF-1α 1790G>A polymorphism is associated with the susceptibility to CSM and can be used as predictor for the clinical outcome in CSM patients receiving ACF treatment.

Association between transforming growth factor beta1 polymorphisms and left ventricle hypertrophy in essential hypertensive subjects.

Left ventricular hypertrophy (LVH) increases the risk of cardiovascular morbid events in hypertension. TGF-beta1 is involved in pathologic states such as cardiac hypertrophy and cardiac fibrosis; we thus postulate that the TGF-beta1 polymorphism is related to LVH in hypertensives. Six hundred and eighty essential hypertensive patients were recruited. Biochemical variables and clinical data were obtained and the determination of LVH was performed by echocardiography. According to the presence of LVH, all subjects were divided into the LVH+ and LVH- group. DNA was obtained, and two coding region polymorphisms of the TGF-beta1 gene (+869 Leu-->Proat codon 10 and +915 ARG-->Pro at codon 25) were analyzed by the polymerase chain reaction. The product was cleaved with the restriction endonucleases. For the polymorphisms of the +869 Leu-->Pro at codon 10, there was no marked difference in the distributions of genotypes and the allele frequencies between the LVH+ and LVH- subjects. For +915 Arg-->Pro at codon 25, a significant difference in the distributions of genotypes of TGF-beta1 was observed. The left ventricular mass index (LVMI) in Arg-Pro genotype carriers was significantly higher than those in the Arg-Arg and Pro-Pro carriers. Multivariate analysis showed that the Arg-Pro genotype was an independent risk factor for LVH (OR 3.23, 95% CI [1.48-5.63, P = 0.002]). The codon 10 genotypes did not show a significant association to LVH. Our data revealed a genetic association of TGF-beta1+915 Arg-->Pro at codon 25 polymorphism with LVH in a Chinese hypertensive population.

Protective role of granulocyte colony-stimulating factor against adriamycin induced cardiac, renal and hepatic toxicities.

Adriamycin (ADR) causes dose-dependant toxicities in heart, liver and kidneys via inducing the peroxidative alterations in organ tissues. Recent studies showed that the granulocyte colony-stimulating factor (G-CSF) exerts beneficial effects on heart, liver and kidney injuries induced by different pathological conditions. We hypothesize that G-CSF have a protective effect on ADR induced cardiac, renal and hepatic toxicities by inhibiting the peroxidative alterations in organ tissues. Wistar rats were randomly divided into control, ADR, ADR+phosphate buffered saline (PBS) and ADR+G-CSF group (n=16 in each group). ADR was administered intraperitoneally every other day at the dose of 2.5 microg/kg each time per rat (total six times of injection during 2 weeks). Rats in the ADR+G-CSF group were injected subcutaneously with G-CSF at the dose of 50 microg/(kg day) (for 8 consecutive days). After 8 weeks, the serum and urine biochemistry variables were determined. The malondialdehyde (MDA) level and the glutathione (GSH) content in the heart, the liver and the kidney tissues were measured. ADR caused significant cardiac, renal and hepatic toxicities indicated by the serum and urine biochemistry variables. The tissue MDA level in the heart, kidney and liver in rats treated with ADR were markedly elevated, while the GSH content in these tissues were significantly reduced. G-CSF administration palliated the cardiac, renal and hepatic toxicities. Notably, G-CSF induced significant reduction of MDA level and increase of GSH content in the heart, kidney and liver tissues. This study suggests that G-CSF play an overall protective effect on ADR-induced toxicities in heart, liver and kidneys and the inhibition of tissue peroxidative alterations might contribute to this beneficial effect.

The G501C polymorphism of oxidized LDL receptor gene [OLR-1] is associated with susceptibility and serum C-reactive protein concentration in Chinese essential hypertensives.

BACKGROUND: Oxidized LDL receptor gene 1 (OLR-1) polymorphism is reportedly associated with several cardiovascular conditions. However, its relationship with essential hypertension remains unknown. The aim of this study is to explore the association of OLR-1 polymorphism at position 501 in the open reading frame (G501C), with the susceptibility of essential hypertension. METHODS: 2-hundred eighty Chinese essential hypertensive and 284 control subjects were enrolled and genetic study was performed. The clinical data, i.e., sex, age, blood pressure, body mass index, smoking history, lipid profile and serum C-reactive protein concentration in both hypertensives and controls were obtained. RESULTS: A significant difference in OLR-1 genotype distributions was noted between the hypertensives and the controls (GG: 67.9% vs. 70.8%; GC: 20.0% vs. 23.6%; CC: 12.1% vs. 5.6%, P=0.021). For G and C allele frequencies, the difference between these 2 groups was significant as well (G: 67.5% vs. 23.5%, C: 82.6% vs. 17.4%, P=0.011). Logistic regression analysis revealed that the CC genotype is an independent risk factor for hypertension (OR=3.036, 95% CI: 1.572-6.174, P=0.016). Furthermore, when the serum C-reactive protein concentration in the hypertensive group was studied according to OLR-1 genotypes, the serum CRP concentration in CC homozygous carriers were found significantly higher than that in GC and GG carriers (1.53+/-0.32, 1.31+/-0.32 and 2.94+/-1.29 respectively, P=0.002). CONCLUSIONS: The CC genotype of OLR-1 G501C polymorphism is associated with susceptibility and serum C-reactive protein concentration in Chinese essential hypertensive population.

[Application of the burned bone morphology and DNA technology in human identification].

Burned bones have their unique characteristics in investigation of fire disaster/crimes, airplane disaster, explosion and other accidents. To study the morphological changes of skeletal tissue and DNA changes at different incinerating temperature might provide precise standard means to determine genera, sex, and age. Genetic locus was also applied in the above fields. The techniques to extract and detect of DNA in burning bones have been improved in recent years. In this article investigation advancement of analysis of burned bones with the morphology, histology, and molecular biology as well as the latest methods and techniques were reviewed. These results provide a new approach for further research and practice in forensic medicine.

Granulocyte colony-stimulating factor reduces cardiomyocyte apoptosis and improves cardiac function in adriamycin-induced cardiomyopathy in rats.

BACKGROUND: Cardiomyocyte apoptosis reportedly participates in the occurrence and progression of dilated cardiomyopathy (DCM). Recent studies have shown that granulocyte colony-stimulating factor (G-CSF) enhances bone marrow cells migration to the damaged heart in the DCM model and improves the ultrastructure of the cardiomyocyte in adriamycin (ADR) induced DCM. However, its influence on cardiac pump function and cardiomyocyte apoptosis has not been studied. METHODS AND MATERIALS: Wistar Rats were randomly grouped into control, ADR, ADR+PBS, ADR+G-CSF group (n = 10). ADR (2.5 mg/kg, 6 times for 2 weeks) was administered intraperitoneally in all rats except the control group. After 2 weeks, the rats in ADR+G-CSF group were injected with G-CSF (50 microg/kg/day for 8 days) subcutaneously. Cardiac function was evaluated by echocardiogram and cardiac catheterization after 4 weeks. Cardiomyocytes apoptosis and apoptosis-related protein Fas were detected by in situ terminal deoxynucleotidyl transferase assay (TUNEL method) and Western blot, respectively. RESULTS: The ADR and ADR+PBS groups showed significant deteriorations of left ventricular functions and high cardiomyocyte apoptosis index, as well as high Fas expressions. Meanwhile, the ADR+G-CSF group showed significant improvement in LV function, inhibition of cardiomyocyte apoptosis compared with the ADR and ADR+Phosphate-Buffered Saline PBS group. The Fas protein expression was remarkably attenuated as well. CONCLUSION: Our results suggest that administration of G-CSF inhibited cardiomyocyte apoptosis and Fas protein expression and contributes to improving cardiac pump function in vivo in ADR induced DCM rat model.