BACKGROUND: Epoxyeicosatrienoic acids (EETs), which are metabolites of arachidonic acid catalyzed by cytochrome P450 epoxygenase, are degraded into inactive dihydroxyeicosatrienoic acids by soluble epoxide hydrolase (sEH). Many studies have revealed that sEH gene deletion exerts protective effects against diabetes. Vascular calcification is a common complication of diabetes, but the potential effects of sEH on diabetic vascular calcification are still unknown. METHODS: The level of aortic calcification in wild-type and Ephx2-/- C57BL/6 diabetic mice induced with streptozotocin was evaluated by measuring the aortic calcium content through alizarin red staining, immunohistochemistry staining, and immunofluorescence staining. Mouse vascular smooth muscle cell lines (MOVAS cells) treated with β-glycerol phosphate (0.01 mol/L) plus advanced glycation end products (50 mg/L) were used to investigate the effects of sEH inhibitors or sEH knockdown and EETs on the calcification of vascular smooth muscle cells, which was detected by Western blotting, alizarin red staining, and Von Kossa staining. RESULTS: sEH gene deletion significantly inhibited diabetic vascular calcification by increasing levels of EETs in the aortas of mice. EETs (especially 11,12-EET and 14,15-EET) efficiently prevented the osteogenic transdifferentiation of MOVAS cells by decreasing nidogen-2 (NID2) expression. Interestingly, suppressing sEH activity by small interfering ribonucleic acid or specific inhibitors did not block osteogenic transdifferentiation of MOVAS cells induced by β-glycerol phosphate and advanced glycation end products. NID2 overexpression significantly abolished the inhibitory effect of sEH gene deletion on diabetic vascular calcification. Moreover, NID2 overexpression mediated by adeno-associated virus 9 vectors markedly increased insulin-like growth factor 2 (IGF2) and phospho-ERK1/2 expression in MOVAS cells. Overall, sEH gene knockout inhibited diabetic vascular calcification by decreasing aortic NID2 expression and, then, inactivating the downstream IGF2-ERK1/2 signaling pathway. CONCLUSIONS sEH gene deletion markedly inhibited diabetic vascular calcification through repressed osteogenic transdifferentiation of vascular smooth muscle cells mediated by increased aortic EET levels, which was associated with decreased NID2 expression and inactivation of the downstream IGF2-ERK1/2 signaling pathway.
Animals ; Mice ; Vascular Calcification/metabolism* ; Mice, Inbred C57BL ; Epoxide Hydrolases/metabolism* ; Diabetes Mellitus, Experimental/genetics* ; Male ; Gene Deletion ; MAP Kinase Signaling System/genetics* ; Cell Line ; Immunohistochemistry ; Muscle, Smooth, Vascular/metabolism* ; Signal Transduction/genetics* ; Mice, Knockout

Vascular calcification significantly increases the incidence of cardiovascular disease and all-cause mortality patients with chronic kidney disease(CKD), severely affecting their health and lifespan. However, the mechanisms underlying vascular calcification in CKD remain incompletely understood, and the available therapeutic agents are limited. Research has found that the transformation of vascular smooth muscle cells(VSMCs) from a contractile phenotype to an osteoblast-like phenotype is a key step in CKD-related vascular calcification. As research on the pathogenesis of calcification progresses, it has been demonstrated that bone morphogenetic protein(BMP) and silent information regulator(SIRT) signaling pathways can participate in the process of vascular calcification by regulating the osteogenic transdifferentiation of VSMCs. Traditional Chinese medicine(TCM) has accumulated a wealth of valuable experience in the prevention and treatment of kidney diseases over centuries. Modern research indicates that TCM, with its multi-pathway, multi-target, and low-toxicity properties, has shown certain advantages in the prevention and treatment of CKD-related vascular calcification and in improving patients' quality of life. Therefore, in this study, we will introduce the latest research progress of TCM in preventing and treating CKD-related vascular calcification, particularly focusing on the BMP and SIRT signaling pathways, with the aim of providing ideas for the clinical diagnosis and treatment of CKD-related vascular calcification with TCM and related basic research.
Humans ; Vascular Calcification/genetics* ; Renal Insufficiency, Chronic/genetics* ; Signal Transduction/drug effects* ; Bone Morphogenetic Proteins/genetics* ; Drugs, Chinese Herbal/therapeutic use* ; Animals ; Sirtuins/genetics* ; Medicine, Chinese Traditional

Osteoclast-like cells are known to inhibit arterial calcification. Receptor activator of NF-κB ligand (RANKL) is likely to act as an inducer of osteoclast-like cell differentiation. However, several studies have shown that RANKL promotes arterial calcification rather than inhibiting arterial calcification. The present study was conducted in order to investigate and elucidate this paradox. Firstly, RANKL was added into the media, and the monocyte precursor cells were cultured. Morphological observation and Tartrate resistant acid phosphatase (TRAP) staining were used to assess whether RANKL could induce the monocyte precursor cells to differentiate into osteoclast-like cells. During arterial calcification, in vivo and in vitro expression of RANKL and its inhibitor, osteoprotegerin (OPG), was detected by real-time PCR. The extent of osteoclast-like cell differentiation was also assessed. It was found RANKL could induce osteoclast-like cell differentiation. There was no in vivo or in vitro expression of osteoclast-like cells in the early stage of calcification. At that time, the ratio of RANKL to OPG was very low. In the late stage of calcification, a small amount of osteoclast-like cell expression coincided with a relatively high ratio of RANKL to OPG. According to the results, the ratio of RANKL to OPG was very low during most of the arterial calcification period. This made it possible for OPG to completely inhibit RANKL-induced osteoclast-like cell differentiation. This likely explains why RANKL had the ability to induce osteoclast-like cell differentiation but acted as a promoter of calcification instead.
Acid Phosphatase ; genetics ; metabolism ; Animals ; Aorta ; drug effects ; metabolism ; pathology ; Cell Differentiation ; Coculture Techniques ; Gene Expression Regulation ; Isoenzymes ; genetics ; metabolism ; Male ; Monocytes ; cytology ; drug effects ; metabolism ; Myocytes, Smooth Muscle ; drug effects ; metabolism ; pathology ; Osteoclasts ; drug effects ; metabolism ; pathology ; Osteoprotegerin ; genetics ; metabolism ; RANK Ligand ; genetics ; metabolism ; pharmacology ; Rats ; Rats, Sprague-Dawley ; Signal Transduction ; Tartrate-Resistant Acid Phosphatase ; Vascular Calcification ; genetics ; metabolism ; pathology

OBJECTIVETo observe the role of magnesium sulfate in vascular calcification, to explore the role and the mechanism of magnesium sulfate in vascular calcification.

METHODSThe vascular calcification model was established by administration of vitamin D3 plus nicotine (VDN) in SD rats. To estimate the extent of calcification by Von Kossa staining, calcium content and alkaline phosphatase activity, osteopontin (OPN) mRNA were determined by using semi-quantitative reverse-transcription polymerase chain reaction.The malondialdehyde (MDA) and nitric oxide (NO) content and activities of superoxide dismutase(SOD) were measured by biochemistry.

RESULTSA strong positive staining of black/brown areas among the elastic fibers of the medial layer in calcified aorta by Von Kossa staining, calcium content and ALP activity in calcified arteries increased by 3.9-and 3.4-fold as compared with the controls. The expression of OPN mRNA was up-regulated by 40% (P < 0.01). The lipid peroxidation products MDA in vascular were increased 2.0-fold (P < 0.01). The NO content and SOD activity were greatly decreased by 64% and 72% (P < 0.01), respectively, compared with controls. However, calcium content and ALP activity in VDN plus magnesium sulfate group were lower than those in VDN group. Low and high dosage magnesium sulfate obviously relieved degree of calcification in the cardiovascular tissues in a dosage-dependent manner (P < 0.01).

CONCLUSIONMagnesium sulfate plays a role in the pathogenesis of vascular calcification by reducing vascular calcification and decreasing vascular injury.

Animals ; Cholecalciferol ; adverse effects ; Magnesium ; pharmacology ; Male ; Nicotine ; adverse effects ; Osteopontin ; metabolism ; RNA, Messenger ; genetics ; Rats ; Vascular Calcification ; chemically induced ; pathology

OBJECTIVETo investigate the differentially expressed genes in rat in the process of regression of vascular calcification by using the suppression subtractive hybridization (SSH).

METHODS24 SD male rats which aged 6 weeks and specific pathogen free grade were selected and randomly divided into 3 groups (n = 8): control group, calcification group and regression group respectively. Vascular calcification model (vitamin D3 plus nicotine, VDN) were made from rats in calcification group and regression group, and rats in control group were intragastric administered with normal saline and lavaged with peanut oil. Rats were bred for 8 weeks in calcification group and control group, while rats in regression group were fed for 16 weeks. All rats were killed to measure concentration of calcium in the arterial tissue and examine the pathological lesion changes. Subtractive hybridization among vascular cDNA sequences from calcification group and regression group were established. The cDNA fragments which expressed higher or lower in regression group than those in calcification group were isolated. Differentially expressed genes with cDNA fragment were inserted into PMD18-T plasmid vector and transformed competent DH-5alpha, cDNA libraries of differentially expressed gene between calcification group and regression group were then constructed. Recombinant vectors were analyzed by colony PCR, positive genes were randomly selected for sequencing and analyzed by BLAST. 4 genes were randomly selected for RT-PCR certification combined with semi-quantitative analysis of DNA bands.

RESULTSVDN model of rats were successfully constructed. Concentration of tissue calcium in calcification group (15.34 mg/g +/- 2.51 mg/g) was significantly increased compared to that in control group (5.20 mg/g +/- 0.75 mg/g, P < 0.001), while in comparison with calcification group (15.34 mg/g +/- 2.51 mg/g), calcium in regression group was relatively lower (12.73 mg/g +/- 1.89 mg/g, P < 0.05). 28 up-regulated genes and 22 down-regulated genes were gained through sequencing and BLAST analysis among positive clones. RT-PCR validation indicated that 4 genes such as prdx3 and Ank2 had increasedly expressed in regression group than those in calcification group, the average fold change was 1.7.

CONCLUSIONRat vascular calcification tissue had characteristic of active regression. Genes in relation to pyrophosphoric acid synthesis, glutamate signal peptides, anti-oxidant and ant-apoptosis were up-regulated, at the same time many genes related to ossification and oxidation activity were down-regulated in the process of calcification regression. Increased expression of calcification suppressor genes accompanying decreased expression of calcification promoting genes might be the intrinsic mechanisms which initiated the active regression of calcified tissues.

Animals ; Aorta ; metabolism ; pathology ; Gene Expression Profiling ; Gene Expression Regulation ; Male ; Rats ; Rats, Sprague-Dawley ; Vascular Calcification ; genetics ; physiopathology

AIMThe process of vascular calcification involves various genetic alterations which may play a very important role in the vascular calcification. Vascular smooth muscle cells undoubtedly composed the main part of vascular cells, and are involved in vascular calcification. So bovine artery smooth muscle cell (BASMC) was used to investigate the gene changes during BASMC's calcification.

METHODSBovine artery smooth muscle cells cultured in vitro was induced calcified by beta-Glycerophosphate (beta-GP). Using DD-PCR technique to screening differentially expressed genes and those differentially expressed bands were reexamined by reverse Northern blot. All the ESTs were sequenced and BLAST with GenBank.

RESULTSTotal 65 cDNAs were isolated as differentially expressed genes and 40 of them were successfully reamplified. Using reverse-Northern blot, seven of these 40 cDNAs were reproducibly expressed differentially between the two cells. Three of them are new bands and have not been reported before.

CONCLUSIONThis is the first time using DD-PCR to screen differentially expressed genes of BASMC calcification. Seven related ESTs were identified relating to BASMC calcification.

Animals ; Arteriosclerosis ; genetics ; metabolism ; pathology ; Cattle ; Cells, Cultured ; Expressed Sequence Tags ; Genetic Variation ; Muscle, Smooth, Vascular ; cytology ; Myocytes, Smooth Muscle ; metabolism ; pathology ; Vascular Calcification ; genetics ; metabolism ; pathology