Curcumin attenuates osteogenic differentiation and calcification of rat vascular smooth muscle cells

Mir-195-5p targets Smad7 regulation of the Wnt/β-catenin pathway to promote osteogenic differentiation of vascular smooth muscle cells

In this study, we sought to investigate the mechanisms of action of miR-195-5p in the osteogenic differentiation of vascular smooth muscle cells (VSMCs), and thereby provide novel insights and a reference for the targeted therapy of arterial media calcification. VSMC differentiation was induced using sodium β-glycerophosphate, and we investigated the effects of transfecting cells with miR-195-5p mimics, vectors overexpressing Smad7, and the Wnt/β-catenin pathway inhibitor (KYA1797K) on VSMC differentiation by determining cell viability and apoptosis, and the mRNA and protein expression of factors associated with osteogenic differentiation and the Wnt/β-catenin pathway. The results revealed that miR-195-5p mimics enhanced the osteogenic differentiation of VSMCs induced by β-glycerophosphate, whereas the overexpression of Smad7 reversed this phenomenon. In addition, KYA1797K was found to promote the effects of Smad7 overexpression. In conclusion, by targeting, Smad7, miR-195-5p promotes the Wnt/β-catenin pathway. and thus the osteogenic differentiation of VSMCs. These findings will provide a reference for elucidating the mechanisms whereby miR-195-5p regulates osteogenic differentiation.

Wogonin inhibits oxidative stress and vascular calcification via modulation of heme oxygenase-1

Vascular calcification (VC) is highly prevalent and increases the morbidity and mortality of cardiovascular diseases. However, the underlying mechanism remains unclear and there is no effective treatment so far. Interestingly, using systems pharmacology approach, we have predicted that Wogonin (Wog) exhibited potential activity against VC. Then we validated the effect of Wog on VC using human and rat vascular smooth muscle cells (VSMCs), rat arterial rings and vitamin D3-overloaded mouse models. Our results showed that Wog dose-dependently inhibited calcification of VSMCs and rat arterial rings. Consistently, alizarin red staining and calcium content assay confirmed that Wog inhibited aortic calcification in vitamin D3-overloaded mice. Moreover, by constructing the protein regulating network of Wog in suppressing VC, we found heme oxygenase-1 (HMOX-1) was regulated by Wog. Additionally, pathway enrichment analysis revealed that inhibition of reactive oxygen species (ROS) pathway participated in the inhibitory role of Wog in VC and HMOX-1 was also involved in this process. Notably, our study revealed that Wog treatment promoted HMOX-1 expression, and reduced ROS levels in VSMCs. Interestingly, both inhibition of HMOX-1 by ZnPP9 and knockdown of HMOX-1 by siRNA independently eliminated the inhibitory effect of Wog on VC. Finally, administration of Wog suppressed aortic calcification in vitamin D3-overloaded mice and this effect was counteracted by ZnPP9,suggesting the crucial role of HMOX-1 in the inhibitory effect of Wog on VC. Collectively, this study combines systems pharmacology-based strategy and experiments to identify the therapeutic potential of Wog for VC via upregulating HMOX-1 and reducing oxidative stress.

Dialdehyde xanthan gum and curcumin synergistically crosslinked bioprosthetic valve leaflets with anti-thrombotic, anti-inflammatory and anti-calcification properties

Currently commercial glutaraldehyde (GA)-crosslinked bioprosthetic valve leaflets (BVLs) suffer from thromboembolic complications, calcification, and limited durability, which are the major stumbling block to wider clinical application of BVLs. Thus, developing new-style BVLs will be an urgent need to enhance the durability of BVLs and alleviate thromboembolic complications. In this study, a quick and effective collaborative strategy of the double crosslinking agents (oxidized polysaccharide and natural active crosslinking agent) was reported to realize enhanced mechanical, and structural stability, excellent hemocompatibility and anti-calcification properties of BVLs. Dialdehyde xanthan gum (AXG) exhibiting excellent stability to heat, acid-base, salt, and enzymatic hydrolysis was first introduced to crosslink decellularized porcine pericardium (D-PP) and then curcumin with good properties of anti-inflammatory, anti-coagulation, anti-liver fibrosis, and anti-atherosclerosis was used to synergistically crosslink and multi-functionalize D-PP to obtain AXG + Cur-PP. A comprehensive evaluation of structural characterization, hemocompatibility, endothelialization potential, mechanical properties and component stability showed that AXG + Cur-PP exhibited better anti-thrombotic properties and endothelialization potential, milder immune responses, excellent anti-calcification properties and enhanced mechanical properties compared with GA-crosslinked PP. Overall, this cooperative crosslinking strategy provides a novel solution to achieve BVLs with enhanced mechanical properties and excellent anti-coagulation, anti-inflammatory, anti-calcification, and the ability to promote endothelial cell proliferation.

Curcumin attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis

Vascular calcification (VC) is the most widespread pathological change in diseases of the vascular system. However, we do not have a good understanding of the molecular mechanisms and effective therapeutic approaches for VC. Curcumin (CUR) is a natural polyphenolic compound that has hypolipidemic, anti-inflammatory, and antioxidant effects on the cardiovascular system. Exosomes are known to have extensive miRNAs for intercellular regulation. This study investigated whether CUR attenuates VC by affecting the secretion of exosomal miRNAs. Calcification models were established in vivo and in vitro using vitamin D3 and β-glycerophosphate, respectively. Appropriate therapeutic concentrations of CUR were detected on vascular smooth muscle cells (VSMCs) using a cell counting kit 8. Exosomes were extracted by super speed centrifugation from the supernatant of cultured VSMCs and identified by transmission electron microscopy and particle size analysis. Functional and phenotypic experiments were performed in vitro to verify the effects of CUR and exosomes secreted by VSMCs treated with CUR on calcified VSMCs. Compared with the calcified control group, both CUR and exosomes secreted by VSMCs after CUR intervention attenuated calcification in VSMCs. Real-Time quantitative PCR (RT-qPCR) experiments showed that miR-92b-3p, which is important for alleviating VC, was expressed highly in both VSMCs and exosomes after CUR intervention. The mimic miR-92b-3p significantly decreased the expression of transcription factor KLF4 and osteogenic factor RUNX2 in VSMCs, while the inhibitor miR-92b-3p had the opposite effect. Based on bioinformatics databases and dual luciferase experiments, the prospective target of miR-92b-3p was determined to be KLF4. Both mRNA and protein of RUNX2 were decreased and increased in VSMCs by inhibiting and overexpressing of KLF4, respectively. In addition, in the rat calcification models, CUR attenuated vitamin D3-induced VC by increasing miR-92b-3p expression and decreasing KLF4 expression in the aorta. In conclusion, our study suggests that CUR attenuates vascular calcification via the exosomal miR-92b-3p/KLF4 axis.

Reactive Oxygen Species in Cardiovascular Calcification: Role of Medicinal Plants

Cardiovascular calcification, including vascular calcification and calcific aortic valve disease (CAVD), is a serious worldwide health problem, especially in older adults. The mechanisms underlying cardiovascular calcifications are complex and multifactorial. An increase in reactive oxygen species (ROS) and oxidative stress play important roles in the initiation and development of cardiovascular calcification. This mini-review summarizes the recent evidence that supports the association of ROS with vascular calcification and CAVD and discusses the role of medicinal plants for the prevention and treatment of cardiovascular calcification.

New Therapeutics Targeting Arterial Media Calcification: Friend or Foe for Bone Mineralization?

The presence of arterial media calcification, a highly complex and multifactorial disease, puts patients at high risk for developing serious cardiovascular consequences and mortality. Despite the numerous insights into the mechanisms underlying this pathological mineralization process, there is still a lack of effective treatment therapies interfering with the calcification process in the vessel wall. Current anti-calcifying therapeutics may induce detrimental side effects at the level of the bone, as arterial media calcification is regulated in a molecular and cellular similar way as physiological bone mineralization. This especially is a complication in patients with chronic kidney disease and diabetes, who are the prime targets of this pathology, as they already suffer from a disturbed mineral and bone metabolism. This review outlines recent treatment strategies tackling arterial calcification, underlining their potential to influence the bone mineralization process, including targeting vascular cell transdifferentiation, calcification inhibitors and stimulators, vascular smooth muscle cell (VSMC) death and oxidative stress: are they a friend or foe? Furthermore, this review highlights nutritional additives and a targeted, local approach as alternative strategies to combat arterial media calcification. Paving a way for the development of effective and more precise therapeutic approaches without inducing osseous side effects is crucial for this highly prevalent and mortal disease.

Dihydromyricetin ameliorates vascular calcification in chronic kidney disease by targeting AKT signaling

Vascular calcification is highly prevalent in chronic kidney disease (CKD), and is characterized by transdifferentiation from contractile vascular smooth muscle cells (VSMCs) into an osteogenic phenotype. However, no effective and therapeutic option to prevent vascular calcification is yet available. Dihydromyricetin (DMY), a bioactive flavonoid isolated from Ampelopsis grossedentata, has been found to inhibit VSMCs proliferation and the injury-induced neointimal formation. However, whether DMY has an effect on osteogenic differentiation of VSMCs and vascular calcification is still unclear. In the present study, we sought to investigate the effect of DMY on vascular calcification in CKD and the underlying mechanism. DMY treatment significantly attenuated calcium/phosphate-induced calcification of rat and human VSMCs in a dose-dependent manner, as shown by Alizarin Red S staining and calcium content assay, associated with down-regulation of osteogenic markers including type I collagen (COL I), Runt-related transcription factor 2 (RUNX2), bone morphogenetic protein 2 (BMP2) and osteocalcin (OCN). These results were further confirmed in aortic rings ex vivo. Moreover, DMY ameliorated vascular calcification in rats with CKD. Additionally, we found that AKT signaling was activated during vascular calcification, whereas significantly inhibited by DMY administration. DMY treatment significantly reversed AKT activator-induced vascular calcification. Furthermore, inhibition of AKT signaling efficiently attenuated calcification, which was similar to that after treatment with DMY alone, and DMY had a better inhibitory effect on calcification as compared with AKT inhibitor. The present study demonstrated that DMY has a potent inhibitory role in vascular calcification partially by inhibiting AKT activation, suggesting that DMY may act as a promising therapeutic candidate for patients suffering from vascular calcification.

N-acetylcysteine (NAC) differentially affects arterial medial calcification and bone formation: The role of l-cysteine and hydrogen sulphide

Arterial medial calcification (AMC) is the deposition of calcium phosphate in the arteries. AMC is widely thought to share similarities with physiological bone formation; however, emerging evidence suggests several key differences between these processes. N-acetylcysteine (NAC) displays antioxidant properties and can generate hydrogen sulphide (H₂ S) and glutathione (GSH) from its deacetylation to l-cysteine. This study found that NAC exerts divergent effects in vitro, increasing osteoblast differentiation and bone formation by up to 5.5-fold but reducing vascular smooth muscle cell (VSMC) calcification and cell death by up to 80%. In vivo, NAC reduced AMC in a site-specific manner by 25% but had no effect on the bone. The actions of l-cysteine and H₂ S mimicked those of NAC; however, the effects of H₂ S were much less efficacious than NAC and l-cysteine. Pharmacological inhibition of H₂ S-generating enzymes did not alter the actions of NAC or l-cysteine; endogenous production of H₂ S was also unaffected. In contrast, NAC and l-cysteine increased GSH levels in calcifying VSMCs and osteoblasts by up to 3-fold. This suggests that the beneficial actions of NAC are likely to be mediated via the breakdown of l-cysteine and the subsequent GSH generation. Together, these data show that while the molecular mechanisms driving the actions of NAC appear similar, the downstream effects on cell function differ significantly between osteoblasts and calcifying VSMCs. The ability of NAC to exert these differential actions further supports the notion that there are differences between the development of pathological AMC and physiological bone formation. NAC could represent a therapeutic option for treating AMC without exerting negative effects on bone.

Spermidine inhibits vascular calcification in chronic kidney disease through modulation of SIRT1 signaling pathway

Vascular calcification is a common pathologic condition in patients with chronic kidney disease (CKD) and aging individuals. It has been established that vascular calcification is a gene‐regulated biological process resembling osteogenesis involving osteogenic differentiation. However, there is no efficient treatment available for vascular calcification so far. The natural polyamine spermidine has been demonstrated to increase life span and protect against cardiovascular disease. It is unclear whether spermidine supplementation inhibits vascular calcification in CKD. Alizarin red staining and quantification of calcium content showed that spermidine treatment markedly reduced mineral deposition in both rat and human vascular smooth muscle cells (VSMCs) under osteogenic conditions. Additionally, western blot analysis revealed that spermidine treatment inhibited osteogenic differentiation of rat and human VSMCs. Moreover, spermidine treatment remarkably attenuated calcification of rat and human arterial rings ex vivo and aortic calcification in rats with CKD. Furthermore, treatment with spermidine induced the upregulation of Sirtuin 1 (SIRT1) in VSMCs and resulted in the downregulation of endoplasmic reticulum (ER) stress signaling components, such as activating transcription factor 4 (ATF4) and CCAAT/enhancer‐binding protein homologous protein (CHOP). Both pharmacological inhibition of SIRT1 by SIRT1 inhibitor EX527 and knockdown of SIRT1 by siRNA markedly blocked the inhibitory effect of spermidine on VSMC calcification. Consistently, EX527 abrogated the inhibitory effect of spermidine on aortic calcification in CKD rats. We for the first time demonstrate that spermidine alleviates vascular calcification in CKD by upregulating SIRT1 and inhibiting ER stress, and this may develop a promising therapeutic treatment to ameliorate vascular calcification in CKD.

Nano-Sized Hydroxyapatite Induces Apoptosis and Osteogenic Differentiation of Vascular Smooth Muscle Cells via JNK/c-JUN Pathway

Purpose

The deposition of hydroxyapatite (HAp) crystals plays an important role in the development of vascular calcification (VC). This study aimed to demonstrate the effects of nanosized HAp (nHAp) on vascular smooth muscle cells (VSMCs) and VC progression.

Methods

Transmission electron microscopy (TEM) was used to examine cellular uptake of nHAp. Cell viability was determined using CCK-8 assay kit. Mitochondrial impairment and reactive oxygen species were detected by TEM and fluorescence dye staining, respectively. Cell apoptosis was detected by Western blot analysis and Annexin V staining. Mouse model of VC was built via applying nHAp on the surface of abdominal aorta. Calcification was visualized by Alizarin red and von Kossa staining.

Results

We found that nHAp could promote osteogenic transformation of VSMCs by elevating expression of runt-related factor 2 (Runx2), osteopontin (OPN) and alkaline phosphatase (ALP), impairing function and morphology of mitochondria and inducing apoptosis of VSMCs. More phosphorylation of c-Jun N-terminal protein kinase/c-JUN (JNK/c-JUN) in VSMCs was detected after mixing nHAp with VSMCs. HAp-induced osteogenic transformation of VSMCs was blocked by JNK inhibitor SP600125, resulted in decreased ALP activity, less Runx2 and OPN expressions. SP600125 also inhibited apoptosis of VSMCs. Application of nHAp to outside of aorta induced osteogenic transformation and apoptosis of VSMCs, and significant deposition of calcium on the vessel walls of mice, which can be effectively attenuated by SP600125.

Conclusion

JNK/c-JUN signaling pathway is critical for nHAp-induced calcification, which could be a potential therapeutic target for controlling the progression of VC.

Histopathological study of JNK in venous wall of patients with chronic venous insufficiency related to osteogenesis process

Chronic venous insufficiency (CVI) is one of the most common vascular pathologies worldwide. One of the risk factors for the development of CVI is aging, which is why it is related to senile changes. The main trigger of the changes that occur in the venous walls in CVI is blood flow reflux, which produces increased hydrostatic pressure, leading to valve incompetence. The cellular response is one of the fundamental processes in vascular diseases, causing the activation of cell signalling pathways such as c-Jun N-terminal kinase (JNK). Metabolic changes and calcifications occur in vascular pathology as a result of pathophysiological processes. The aim of this study was to determine the expression of JNK in venous disease and its relationship with the role played by the molecules involved in the osteogenic processes in venous tissue calcification. This was a cross-sectional study that analyzed the greater saphenous vein wall in 110 patients with (R) and without venous reflux (NR), classified according to age. Histopathological techniques were used and protein expression was analysed using immunohistochemistry techniques for JNK and markers of osteogenesis (RUNX2, osteocalcin (OCN), osteopontin (OPN)). Significantly increased JNK, RUNX2, OCN, OPN and pigment epithelium-derived factor (PEDF) protein expression and the presence of osseous metaplasia and amorphous calcification were observed in younger patients (<50 years) with venous reflux. This study shows for the first time the existence of an osteogenesis process related to the expression of JNK in the venous wall.

Liver kinase B1 inhibits smooth muscle calcification via high mobility group box 1

Vascular calcification is a common pathological feature of atherosclerosis, chronic kidney disease, vascular injury, and aging. Liver kinase B1 (LKB1) plays pivotal roles in cellular processes such as apoptosis, metabolism, and cell cycle regulation. In addition, growing evidence has indicated that LKB1 functions as a tumor suppressor gene. However, its role in vascular calcification has not been reported. LKB1^flox/flox mice were hybridized with SM22-CreER^T2 transgenic mice and adult mice received tamoxifen to obtain smooth muscle-specific LKB1-knockout (LKB1^SMKO) mice. LKB1 expression was decreased under calcifying conditions, and LKB1 overexpression had a protective effect on vascular calcification. However, high mobility group box 1 (HMGB1) overexpression partially counteracted the promotion of vascular calcification induced by LKB1 overexpression. Mechanically, LKB1 could bind to HMGB1 to promote HMGB1 degradation. Furthermore, LKB1^SMKO mice showed intensified vascular calcification, which was alleviated by treatment with the HMGB1 inhibitor glycyrrhizic acid. Based on our results, LKB1 may inhibit vascular calcification via inhibiting HMGB1 expression.

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LKB1 expression was reduced under calcifying conditions.

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LKB1 overexpression had a protective effect on vascular calcification.

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Binding of LKB1 to HMGB1 promoted HMGB1 degradation.

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LKB1 may inhibit vascular calcification by inhibiting HMGB1 expression.

Apelin-13 attenuates high glucose-induced calcification of MOVAS cells by regulating MAPKs and PI3K/AKT pathways and ROS-mediated signals

Vascular calcification (VC) is an inducement of many cardiovascular diseases. Clinic evidences have confirmed that diabetes was the independent risk factor for VC, and the mechanism has not been well explored. Apelin as a ligand molecule is widely found in the cardiovascular system and showed potential in inhibiting VC, but the inhibitory effect and mechanism of apelin-13 against high glucose-induced VC have not been investigated yet. Herein, apelin-13 was employed to inhibit high glucose-induced VC in mouse aortic vascular smooth muscle cells (MOVAS), and the underlying mechanism was explored. The results showed that apelin-13 significantly inhibited high glucose-induced cells proliferation, migration and invasion of MOVAS cells. Apelin-13 also effectively attenuated high glucose-induced calcification by inhibiting alkaline phosphatase (ALP) activity and expression. Further investigation revealed that apelin-13 dramatically suppressed high glucose-induced DNA damage through inhibiting reactive oxide species (ROS) generation. Moreover, apelin-13 also effectively improved high glucose-induced dysfunction of MAPKs and PI3K/AKT. Inhibition of ERK by inhibitor (U0126) significantly blocked high glucose-induced calcification, which further confirmed the significance of MAPKs. Taken together, these results suggested that apelin-13 had the potential to attenuate high glucose-induced calcification of MOVAS cells by inhibiting ROS-mediated DNA damage and regulating MAPKs and PI3K/AKT pathways. Our findings validated the strategy of using apelin-13 maybe a novel way in treating high glucose-mediated VC.

Curcumin-crosslinked acellular bovine pericardium for the application of calcification inhibition heart valves

Glutaraldehyde (GA) crosslinked bovine or porcine pericardium tissues exhibit high cell toxicity and calcification in the construction of bioprosthetic valves, which accelerate the failure of valve leaflets and motivate the exploration for alternatives. Polyphenols, including curcumin, procyanidin and quercetin, etc, have showed great calcification inhibition potential in crosslinking collagen and elastin scaffolds. Herein, we developed an innovative phenolic fixing technique by using curcumin as the crosslinking reagent for valvular materials. X-ray photoelectron spectroscopy and Fourier transform infrared spectrometry assessments confirmed the hydrogen bond between curcumin and acellular bovine pericardium. Importantly, the calcification inhibition capability of the curcumin-crosslinked bovine pericardium was proved by the dramatically reduced Ca²⁺ content in the curcumin-fixed group in in vitro assay, a juvenile rat subcutaneous implants model, as well as an osteogenic differentiation model. In addition, the results showed that the curcumin-fixed bovine pericardium exhibited better performance in the areas of mechanical performance, hemocompatibility and cytocompatibility, in comparison with the GA group and the commercialized product. In summary, we demonstrated that curcumin was a feasible crosslinking reagent to fix acellular bovine pericardium, which showed great potential for biomedical applications, particularly in cardiovascular biomaterials with calcification inhibition capacity.

Inhibition of vascular calcification by microRNA-155-5p is accompanied by the inactivation of TGF-β1/Smad2/3 signaling pathway

Vascular calcification (VC) is a vital factor for cardiovascular morbidity and mortality. Accumulating data suggest that microRNA (miR) is implicated in the VC. The main purpose of this study is to study the influence of miR-155-5p overexpression on VC development in vitro and in vivo. Immunofluorescence staining, real-time PCR, alizarin red staining, alkaline phosphatase (ALP) activity assay, western blot, luciferase assay, hematoxylin-eosin (HE), Masson's trichrome staining, and calcium content assay were used in this research. The results showed that miR-155-5p was decreased in the rat vascular smooth muscle cells (rVSMCs) undergoing calcification in vitro. MiR-155-5p overexpression reversed the increase of calcification and ALP activity in calcified cells. Further, overexpression of miR-155-5p inhibited the transforming growth factor-β1 (TGF-β1)/Smad2/3 signaling pathway, as evidenced by decreased protein expression of TGF-β1, pSmad-2 and pSmad-3 in rVSMCs. MiR-155-5p was showed to target Smad2 directly. Moreover, miR-155-5p upregulation reduced vascular thickening, fibrosis and calcium content of aorta abdominalis in CaCl₂-mediated VC model. Collectively, our results suggest that miR-155-5p overexpression may inhibit VC development through suppressing TGF-β1/Smad2/3 signaling pathway in vivo and in vitro, indicating that miR-155-5p may act as a potential therapeutic target for VC-related disease.

Curcumin inhibits calcification of human aortic valve interstitial cells by interfering NF-κB, AKT, and ERK pathways

The osteogenic differentiation of human aortic valve interstitial cells (hVICs) is the key cellular mechanism of calcified aortic valve disease (CAVD). This study aimed to explore how curcumin (CCM) inhibits the osteogenic differentiation of hVICs and elucidate the molecular mechanisms involved. In this study, CCM inhibited the osteogenic differentiation of hVICs under osteogenic medium (OM) conditions by reversing the OM-induced increase in calcified nodule formation and osteogenesis-specific markers (ALP and Runx2). RNA sequencing identified 475 common differentially expressed genes with Venn diagrams of the different groups. Kyoto Encyclopedia of Genes and Genomes enrichment revealed that the CCM inhibition of hVIC osteogenic differentiation was enriched in the NF-κB, PI3K-AKT, TNF, Jak-STAT, and MAPK signaling pathways. In addition, CCM suppressed the phosphorylation of ERK, IκBα, AKT, and interfered with the translocation of P65 into the cell nucleus in hVICs under OM culture conditions. In conclusion, CCM inhibited the osteogenic differentiation of hVICs via interfering with the activation of NF-κB/AKT/ERK signaling pathways. Our findings provide novel insights into a critical role for CCM in CAVD progression and shed new light on CCM-directed therapeutics for CAVD.

Trimethylamine-N-Oxide Promotes Vascular Calcification Through Activation of NLRP3 (Nucleotide-Binding Domain, Leucine-Rich-Containing Family, Pyrin Domain-Containing-3) Inflammasome and NF-κB (Nuclear Factor κB) Signals

Objectives:

Vascular calcification is highly prevalent in patients with chronic kidney disease. Increased plasma trimethylamine N-oxide (TMAO), a gut microbiota-dependent product, concentrations are found in patients undergoing hemodialysis. However, a clear mechanistic link between TMAO and vascular calcification is not yet established. In this study, we investigate whether TMAO participates in the progression of vascular calcification using in vitro, ex vivo, and in vivo models.

Approach and Results:

Alizarin red staining revealed that TMAO promoted calcium/phosphate-induced calcification of rat and human vascular smooth muscle cells in a dose-dependent manner, and this was confirmed by calcium content assay. Similarly, TMAO upregulated the expression of bone-related molecules including Runx2 (Runt-related transcription factor 2) and BMP2 (bone morphogenetic protein-2), suggesting that TMAO promoted osteogenic differentiation of vascular smooth muscle cells. In addition, ex vivo study also showed the positive regulatory effect of TMAO on vascular calcification. Furthermore, we found that TMAO accelerated vascular calcification in rats with chronic kidney disease, as indicated by Mico-computed tomography analysis, alizarin red staining and calcium content assay. By contrast, reducing TMAO levels by antibiotics attenuated vascular calcification in chronic kidney disease rats. Interestingly, TMAO activated NLRP3 (nucleotide-binding domain, leucine-rich-containing family, pyrin domain-containing-3) inflammasome and NF-κB (nuclear factor κB) signals during vascular calcification. Inhibition of NLRP3 inflammasome and NF-κB signals attenuated TMAO-induced vascular smooth muscle cell calcification.

Conclusions:

This study for the first time demonstrates that TMAO promotes vascular calcification through activation of NLRP3 inflammasome and NF-κB signals, suggesting the potential link between gut microbial metabolism and vascular calcification. Reducing the levels of TMAO could become a potential treatment strategy for vascular calcification in chronic kidney disease.

The Effect of Curcumin on the Differentiation of Mesenchymal Stem Cells into Mesodermal Lineage

Curcumin has been placed at the forefront of the researcher's attention due to its pleiotropic pharmacological effects and health benefits. A considerable volume of articles has pointed out curcumin's effects on the fate of stem cell differentiation. In this review, a descriptive mechanism of how curcumin affects the outcome of the differentiation of mesenchymal stem cells (MSCs) into the mesodermal lineage-i.e., adipocyte, osteocyte, and chondrocyte differentiation-is compiled from the literature. The sections include the mechanism of inhibition or induction of MSCs differentiation to each lineage, their governing molecular mechanisms, and their signal transduction pathways. The effect of different curcumin doses and its structural modifications on the MSCs differentiation is also discussed.

CDC42 promotes vascular calcification in chronic kidney disease

Vascular calcification is prevalent in patients with chronic kidney disease (CKD) and a major risk factor of cardiovascular disease. Vascular calcification is now recognised as a biological process similar to bone formation involving osteogenic differentiation of vascular smooth muscle cells (VSMCs). Cell division cycle 42 (CDC42), a Rac1 family member GTPase, is essential for cartilage development during endochondral bone formation. However, whether CDC42 affects osteogenic differentiation of VSMCs and vascular calcification remains unknown. In the present study, we observed a significant increase in the expression of CDC42 both in rat VSMCs and in calcified arteries during vascular calcification. Alizarin red staining and calcium content assay revealed that adenovirus-mediated CDC42 overexpression led to an apparent VSMC calcification in the presence of calcifying medium, accompanied with up-regulation of bone-related molecules including RUNX2 and BMP2. By contrast, inhibition of CDC42 by ML141 significantly blocked calcification of VSMCs in vitro and aortic rings ex vivo. Moreover, ML141 markedly attenuated vascular calcification in rats with CKD. Furthermore, pharmacological inhibition of AKT signal was shown to block CDC42-induced VSMC calcification. These findings demonstrate for the first time that CDC42 contributes to vascular calcification through a mechanism involving AKT signalling; this uncovered a new function of CDC42 in regulating vascular calcification. This may provide a potential therapeutic target for the treatment of vascular calcification in the context of CKD. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Mechanics insights of curcumin in myocardial ischemia: Where are we standing?

Cardiovascular disorders are known as one of the main health problems which are associated with mortality worldwide. Myocardial ischemia (MI) is improper blood supply to myocardium which leads from serious complications to life-threatening problems like AMI, atherosclerosis, hypertension, cardiac-hypertrophy as well as diabetic associated complications as diabetic atherosclerosis/cardiomyopathy/hypertension. Despite several efforts, the current therapeutic platforms are not related with significant results. Hence, it seems, developing novel therapies are required. In this regard, increasing evidences indicated, curcumin (CRC) acts as cardioprotective agent. Given that CRC and its analogs exert their cardioprotective effects via affecting on a variety of cardiovascular diseases-related mechanisms (i.e., Inflammation, and oxidative stress). Herein, for first time, we have highlighted the protective impacts of CRC against MI. This review might be a steppingstone for further investigation into the clinical implications of the CRC against MI. Furthermore, it pulls in light of a legitimate concern for scientific community, seeking novel techniques and characteristic dynamic biopharmaceuticals for use against myocardial ischemia.

ACVR1-knockout promotes osteogenic differentiation by activating the Wnt signaling pathway in mice

Osteogenic differentiation refers to the process of bone formation and remodeling, which is controlled by complex molecular mechanisms. Activin A receptor type I (ACVR1) is reported to be associated with osteogenic differentiation. However, the underlying molecular mechanism remains elusive. Therefore, this study evaluates the function of ACVR1 in osteogenic differentiation through the Wnt signaling pathway. The expression of osteocalcin (Oc) and osterix together with osteogenic differentiation and mineralization was examined in ACVR1-knockout (KO) mouse. Furthermore, the Wnt signaling pathway was inhibited in bone marrow stromal cells (BMSCs) of mice to explore the role of the Wnt signaling pathway in osteogenic differentiation by means of alkaline phosphatase (ALP) activity detection and evaluation of mineralized nodules and calcium content. Subsequently, the effect of ACVR1 on the Wnt signaling pathway was assessed by determining the expression of ACVR1, β-catenin, glycogen synthase kinase 3 β (GSK3β), dickkopf-related protein 1 (DKK1), and frizzled class receptor 1 (FZD1). Both their effects on osteogenic differentiation were further evaluated by determination of Oc, osterix, and Runx2 expression. AVCR1 KO mice exhibited increased Oc and osterix expression and promoted bone resorption and formation. ACVR1-knockout was observed to activate the Wnt signaling pathway with an increase of β-catenin and reductions in GSK3β, DKK1, and FZD1. With the inhibited Wnt signaling pathway expression of Oc, osterix, and Runx2 was decreased, and ALP activity, mineralized nodule, and calcium content in cellular matrix were decreased as well, indicating that inactivation of the Wnt signaling pathway reduced the differentiation of BMSCs into osteoclasts. These findings indicate that ACVR1-knockout promotes osteogenic differentiation by activating the Wnt signaling pathway in mice.

Comparison between curcumin and all-trans retinoic acid in the osteogenic differentiation of mouse bone marrow mesenchymal stem cells

The use of bone marrow mesenchymal stem cells (BMSCs) has great potential in cell therapy, particularly in the orthopedic field. BMSCs represent a valuable renewable cell source that have been successfully utilized to treat damaged skeletal tissue and bone defects. BMSCs can be induced to differentiate into osteogenic lineages via the addition of inducers to the growth medium. The present study examined the effects of all-trans retinoic acid (ATRA) and curcumin on the osteogenic differentiation of mouse BMSCs. Morphological changes, the expression levels of the bone-associated gene markers bone morphogenetic protein 2, runt-related transcription factor and osterix during differentiation, an in vitro mineralization assay, and changes in osteocalcin expression revealed that curcumin supplementation promoted the osteogenic differentiation of BMSCs. By contrast, the application of ATRA increased osteogenic differentiation during the early stages, but during the later stages, it decreased the mineralization of differentiated cells. In addition, to the best of our knowledge, the present study is the first to examine the effect of curcumin on the osteogenic potency of mouse embryonic fibroblasts (MEFs) after reprogramming with human lim mineralization protein (hLMP-3), which is a positive osteogenic regulator. The results revealed that curcumin-supplemented culture medium increased hLMP-3 osteogenic potency compared with that of MEFs cultured in the non-supplemented medium. The present results demonstrate that enrichment of the osteogenic culture medium with curcumin, a natural osteogenic inducer, increased the osteogenic differentiation capacity of BMSCs as well as that of MEFs reprogrammed with hLMP-3.

Influences of Sex and Estrogen in Arterial and Valvular Calcification

Vascular and cardiac valvular calcification was once considered to be a degenerative and end stage product in aging cardiovascular tissues. Over the past two decades, however, a critical mass of data has shown that cardiovascular calcification can be an active and highly regulated process. While the incidence of calcification in the coronary arteries and cardiac valves is higher in men than in age-matched women, a high index of calcification associates with increased morbidity, and mortality in both sexes. Despite the ubiquitous portending of poor outcomes in both sexes, our understanding of mechanisms of calcification under the dramatically different biological contexts of sex and hormonal milieu remains rudimentary. Understanding how the critical context of these variables inform our understanding of mechanisms of calcification-as well as innovative strategies to target it therapeutically-is essential to advancing the fields of both cardiovascular disease and fundamental mechanisms of aging. This review will explore potential sex and sex-steroid differences in the basic biological pathways associated with vascular and cardiac valvular tissue calcification, and potential strategies of pharmacological therapy to reduce or slow these processes.

Hyaluronan negatively regulates vascular calcification involving BMP2 signaling

Vascular calcification is a highly regulated biological process similar to bone formation involving osteogenic differentiation of vascular smooth muscle cells (VSMCs). Hyaluronan (HA), a major structural component of the extracellular matrix in cartilage, has been shown to inhibit osteoblast differentiation. However, whether HA affects osteogenic differentiation and calcification of VSMCs remains unclear. In the present study, we used in vitro and ex vivo models of vascular calcification to investigate the role of HA in vascular calcification. Both high and low molecular weight HA treatment significantly reduced calcification of rat VSMCs in a dose-dependent manner, as detected by alizarin red staining and calcium content assay. Ex vivo study further confirmed the inhibitory effect of HA on vascular calcification. Similarly, HA treatment decreased ALP activity and expression of bone-related molecules including Runx2, BMP2 and Msx2. By contrast, inhibition of HA synthesis by 4-methylumbelliferone (4MU) promoted calcification of rat VSMCs. In addition, adenovirus-mediated overexpression of HA synthase 2 (HAS2), a major HA synthase in VSMCs, also inhibited calcification of VSMCs, whereas CRISPR/Cas9-mediated HAS2 knockout promoted calcification of rat A10 cells. Furthermore, we found that BMP2 signaling was inhibited in VSMCs after HA treatment. Recombinant BMP2 enhanced high calcium and phosphate-induced VSMC calcification, which can be blocked by HA treatment. Taken together, these findings suggest that HA inhibits vascular calcification involving BMP2 signaling.

Curcumin represses mouse 3T3-L1 cell adipogenic differentiation via inhibiting miR-17-5p and stimulating the Wnt signalling pathway effector Tcf7l2

Understanding mechanisms underlying adipogenic differentiation may lead to the discovery of novel therapeutic targets for obesity. Wnt signalling pathway activation leads to repressed adipogenic differentiation while certain microRNAs may regulate pre-adipocyte proliferation and differentiation. We show here that in mouse white adipose tissue, miR-17-5p level is elevated after high fat diet consumption. miR-17-5p upregulates adipogenic differentiation, as its over-expression increased while its inhibition repressed 3T3-L1 differentiation. The Tcf7l2 gene encodes a key Wnt signalling pathway effector, and its human homologue TCF7L2 is a highly regarded diabetes risk gene. We found that Tcf7l2 is an miR-17-5p target and confirmed the repressive effect of Tcf7l2 on 3T3-L1 adipogenic differentiation. The natural plant polyphenol compound curcumin possesses the body weight lowering effect. We observed that curcumin attenuated miR-17-5p expression and stimulated Tcf7l2 expression in 3T3-L1 cells. These, along with the elevation of miR-17-5p expression in mouse epididymal fat tissue in response to high fat diet consumption, allowed us to suggest that miR-17-5p is among central switches of adipogenic differentiation. It activates adipogenesis via repressing the Wnt signalling pathway effector Tcf7l2, and its own expression is likely nutritionally regulated in health and disease.