Differentiation Of Vascular Cells Research Articles

Free Fatty Acids and Free Fatty Acid Receptors: Role in Regulating Arterial Function.

The metabolic network's primary sources of free fatty acids (FFAs) are long- and medium-chain fatty acids of triglyceride origin and short-chain fatty acids produced by intestinal microorganisms through dietary fibre fermentation. Recent studies have demonstrated that FFAs not only serve as an energy source for the body's metabolism but also participate in regulating arterial function. Excess FFAs have been shown to lead to endothelial dysfunction, vascular hypertrophy, and vessel wall stiffness, which are important triggers of arterial hypertension and atherosclerosis. Nevertheless, free fatty acid receptors (FFARs) are involved in the regulation of arterial functions, including the proliferation, differentiation, migration, apoptosis, inflammation, and angiogenesis of vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs). They actively regulate hypertension, endothelial dysfunction, and atherosclerosis. The objective of this review is to examine the roles and heterogeneity of FFAs and FFARs in the regulation of arterial function, with a view to identifying the points of intersection between their actions and providing new insights into the prevention and treatment of diseases associated with arterial dysfunction, as well as the development of targeted drugs.

EVs-miR-17-5p attenuates the osteogenic differentiation of vascular smooth muscle cells potentially via inhibition of TGF-β signaling under high glucose conditions

Vascular calcification, which is a major complication of diabetes mellitus, is an independent risk factor for cardiovascular disease. Osteogenic differentiation of vascular smooth muscle cells (VSMCs) is one of the key mechanisms underlying vascular calcification. Emerging evidence suggests that macrophage-derived extracellular vesicles (EVs) may be involved in calcification within atherosclerotic plaques in patients with diabetes mellitus. However, the role of macrophage-derived EVs in the progression of vascular calcification is largely unknown. In this study, we investigated whether macrophage-derived EVs contribute to the osteogenic differentiation of VSMCs under high glucose conditions. We isolated EVs that were secreted by murine peritoneal macrophages under normal glucose (EVs-NG) or high glucose (EVs-HG) conditions. miRNA array analysis in EVs from murine macrophages showed that miR-17-5p was significantly increased in EVs-HG compared with EVs-NG. Prediction analysis with miRbase identified transforming growth factor β receptor type II (TGF-β RII) as a potential target of miR-17-5p. EVs-HG as well as miR-17-5p overexpression with lipid nanoparticles inhibited the gene expression of Runx2, and TGF-β RII. Furthermore, we demonstrated that VSMCs transfected with miR-17-5p mimic inhibited calcium deposition. Our findings reveal a novel role of macrophage-derived EVs in the negative regulation of osteogenic differentiation in VSMCs under high glucose conditions.

Myogenic Anti-Nucleolin Aptamer iSN04 Inhibits Proliferation and Promotes Differentiation of Vascular Smooth Muscle Cells.

De-differentiation and subsequent increased proliferation and inflammation of vascular smooth muscle cells (VSMCs) is one of the mechanisms of atherogenesis. Maintaining VSMCs in a contractile differentiated state is therefore a promising therapeutic strategy for atherosclerosis. We have reported the 18-base myogenetic oligodeoxynucleotide, iSN04, which serves as an anti-nucleolin aptamer and promotes skeletal and myocardial differentiation. The present study investigated the effect of iSN04 on VSMCs because nucleolin has been reported to contribute to VSMC de-differentiation under pathophysiological conditions. Nucleolin is localized in the nucleoplasm and nucleoli of both rat and human VSMCs. iSN04 without a carrier was spontaneously incorporated into VSMCs, indicating that iSN04 would serve as an anti-nucleolin aptamer. iSN04 treatment decreased the ratio of 5-ethynyl-2'-deoxyuridine (EdU)-positive proliferating VSMCs and increased the expression of α-smooth muscle actin, a contractile marker of VSMCs. iSN04 also suppressed angiogenesis of mouse aortic rings ex vivo, which is a model of pathological angiogenesis involved in plaque formation, growth, and rupture. These results demonstrate that antagonizing nucleolin with iSN04 preserves VSMC differentiation, providing a nucleic acid drug candidate for the treatment of vascular disease.

PagJAZ5 regulates cambium activity through coordinately modulating cytokinin concentration and signaling in poplar.

Wood is resulted from the radial growth paced by the division and differentiation of vascular cambium cells in woody plants, and phytohormones play important roles in cambium activity. Here, we identified that PagJAZ5, a key negative regulator of jasmonate (JA) signaling, plays important roles in enhancing cambium cell division and differentiation by mediating cytokinin signaling in poplar 84K (Populus alba × Populus glandulosa). PagJAZ5 is preferentially expressed in developing phloem and cambium, weakly in developing xylem cells. Overexpression (OE) of PagJAZ5m (insensitive to JA) increased cambium activity and xylem differentiation, while jaz mutants showed opposite results. Transcriptome analyses revealed that cytokinin oxidase/dehydrogenase (CKXs) and type-A response regulators (RRs) were downregulated in PagJAZ5m OE plants. The bioactive cytokinins were significantly increased in PagJAZ5m overexpressing plants and decreased in jaz5 mutants, compared with that in 84K plants. The PagJAZ5 directly interact with PagMYC2a/b and PagWOX4b. Further, we found that the PagRR5 is regulated by PagMYC2a and PagWOX4b and involved in the regulation of xylem development. Our results showed that PagJAZ5 can increase cambium activity and promote xylem differentiation through modulating cytokinin level and type-A RR during wood formation in poplar.

A CEBPB/miR-32–5p/GATA6 axis promotes vascular calcification in type 2 diabetes

Vascular calcification in diabetes patients is a major independent risk factor for developing diabetic cardiovascular complications. However, the mechanisms by which diabetes leads to vascular calcification are complex and not yet fully understood. Our previous study revealed that miR-32–5p is a potential new diagnostic marker for coronary artery calcification. In this study, we found that miR-32–5p levels were significantly greater in the plasma of type 2 diabetes patients with coronary artery calcification and were positively correlated with the coronary artery calcification score. In type 2 diabetic mice, miR-32–5p levels were also elevated in the aorta, and knockout of miR-32–5p inhibited the osteogenic differentiation of vascular smooth muscle cells in vivo. Furthermore, overexpression of miR-32–5p promoted vascular smooth muscle cell calcification, while antagonism of miR-32–5p inhibited vascular smooth muscle cell calcification under high-glucose conditions. GATA binding protein 6 (GATA6) was identified as the key target gene through which miR-32–5p promotes vascular smooth muscle cell calcification. Overexpression of GATA6 antagonized the effects of miR-32–5p on vascular calcification. Additionally, high glucose levels were shown to induce the upregulation of miR-32–5p by activating CCAAT/enhancer binding protein beta (CEBPB). These results suggest that miR-32–5p is an important procalcification factor in vascular calcification associated with type 2 diabetes and identify the CEBPB/miR-32–5p/GATA6 axis as a potential biomarker and therapeutic target for preventing and treating vascular calcification in type 2 diabetes.

Epigallocatechin-3-gallate inhibits osteogenic differentiation of vascular smooth muscle cells through the transcription factor JunB.

Medial arterial calcification (MAC) accompanying chronic kidney disease (CKD) leads to increased vessel wall stiffness, myocardial ischemia, heart failure, and increased cardiovascular morbidity and mortality. Unfortunately, there are currently no drugs available to treat MAC. The natural polyphenol epigallocatechin-3-gallate (EGCG) has been demonstrated to protect against cardiovascular disease; however, whether EGCG supplementation inhibits MAC in CKD remains unclear. In this study, we utilize a CKD-associated MAC model to investigate the effects of EGCG on vascular calcification and elucidate the underlying mechanisms involved. Our findings demonstrate that EGCG treatment significantly reduces calcium phosphate deposition and osteogenic differentiation of VSMCs in vivo and in vitro in a dose-dependent manner. In addition, through RNA sequencing (RNA-seq) analysis, we show a significant activation of the transcription factor JunB both in CKD mouse arteries and in osteoblast-like VSMCs. Notably, EGCG effectively suppresses CKD-associated MAC by inhibiting the activity of JunB. In addition, overexpression of JunB can abolish while knockdown of JunB can enhance the inhibitory effect of EGCG on the osteogenic differentiation of VSMCs. Furthermore, EGCG supplementation inhibits MAC in CKD via modulation of the JunB-dependent Ras/Raf/MEK/ERK signaling pathway. In conclusion, our study highlights the potential therapeutic value of EGCG for managing CKD-associated MAC, as it mitigates this pathological process through targeted inactivation of JunB.

#571 Vitamin D receptor from VSMCs regulates vascular calcification during CKD: a potential role for miR-145a

Abstract Background and Aims Vascular calcification (VC) is a highly prevalent complication of chronic kidney disease (CKD) and is associated with the higher morbidity-mortality of patients with CKD. Vitamin D receptor (VDR) has been proposed to play a role in the osteoblastic differentiation of vascular smooth muscle cells (VSMCs), but the involvement of vitamin D (1, 25D) in VC associated to CKD is controversial. Accumulating evidence points to microRNAs as important players in the process of VC and recent studies show that miR-145a expression decreases in VSMCs during VC. In addition, VDR has been considered as a potent regulator of these small molecules, while miR-145a was identified as a target for 1, 25D. Our aim was to determine the role of local vitamin D signalling in VSMCs during CKD-induced VC and the involvement of miR-145a in this process. Method We used epigastric arteries from CKD-affected patients and from individuals with normal renal function. In vivo, we employed an experimental model of CKD-induced VC in mice with conditional deletion of VDR in VSMC (Myh11-CreERT2+ VDRlox/lox), while in vitro, we used mouse VSMC with (VDRwt) or without VDR (VDRko) incubated in calcification media. Transfection experiments with mmu-miR-145a-5p mimic or mmu-miR-145a-5p inhibitor were carried out in mouse VDRwt VSMCs. Results CKD-affected patients showed an increase in VC, alongside an increased arterial expression of VDR compared with controls with normal renal function. Conditional gene silencing of VDR in arterial VSMCs led to a significant decrease of VC in the mouse model of CKD, despite similar levels of renal impairment and serum calcium and phosphate levels. This was accompanied by lower arterial expression of osteopontin (OPN) and lamin A, and a higher expression of sclerostin (SOST). Runx2 was increased in arteries of both CKD groups independently of the presence of VDR in VSMCs. Furthermore, CKD-affected mice showed a reduction of miR-145a expression in calcified arteries, which was significantly recovered in animals with deletion of VDR in VSMCs. In vitro, the absence of VDR prevented VC, inhibited the increase of OPN, and re-established the expression of miR-145a. Forced expression of miR-145a in vitro in VDRwt VSMCs blunted VC and decreased OPN levels. Mir-145a levels markedly decreased both in human and mouse VDRwt VSMCs incubated in calcification media and 1, 25D. Overexpression of miR-145a suppressed the levels of OPN induced by 1, 25D, while the inhibition of mir-145a led to a significant increase in OPN levels, even higher than in cells treated solely with 1, 25D. A predicted miR-145a-binding site was detected at the 3’UTR of OPN mRNA transcript, through the extended seed region of the miRNA, pointing to OPN as a possible target of mir-145a during VC in CKD. There were no significant differences in Runx2 levels in 1, 25D-treated cells after transfection with mir-145a mimic or inhibitor. Conclusion VDR is induced in calcified VSMCs during CKD where it can modulate the expression of promoters and inhibitors of VSMC transdifferentiation, as well as small noncoding RNA molecules such as mir-145a that modulate VC. The regulation of these pathways by VDR seems to be essential for the settings of CKD-induced VC, as deletion of VDR from VSMCs prevented it.

Prevotella copri promotes vascular calcification via lipopolysaccharide through activation of NF-κB signaling pathway

ABSTRACT Emerging evidence indicates that alteration of gut microbiota plays an important role in chronic kidney disease (CKD)-related vascular calcification (VC). We aimed to investigate the specific gut microbiota and the underlying mechanism involved in CKD-VC. We identified an increased abundance of Prevotella copri (P. copri) in the feces of CKD rats (induced by using 5/6 nephrectomy followed by a high calcium and phosphate diet) with aortic calcification via amplicon sequencing of 16S rRNA genes. In patients with CKD, we further confirmed a positive correlation between abundance of P. copri and aortic calcification scores. Moreover, oral administration of live P. copri aggravated CKD-related VC and osteogenic differentiation of vascular smooth muscle cells in vivo, accompanied by intestinal destruction, enhanced expression of Toll-like receptor-4 (TLR4), and elevated lipopolysaccharide (LPS) levels. In vitro and ex vivo experiments consistently demonstrated that P. copri-derived LPS (Pc-LPS) accelerated high phosphate-induced VC and VSMC osteogenic differentiation. Mechanistically, Pc-LPS bound to TLR4, then activated the nuclear factor κB (NF-κB) and nucleotide-binding domain, leucine-rich–containing family, pyrin domain–containing-3 (NLRP3) inflammasome signals during VC. Inhibition of NF-κB reduced NLRP3 inflammasome and attenuated Pc-LPS-induced VSMC calcification. Our study clarifies a novel role of P. copri in CKD-related VC, by the mechanisms involving increased inflammation-regulating metabolites including Pc-LPS, and activation of the NF-κB/NLRP3 signaling pathway. These findings highlight P. copri and its-derived LPS as potential therapeutic targets for VC in CKD.

USP10 alleviates Nε-carboxymethyl-lysine-induced vascular calcification and atherogenesis in diabetes mellitus by promoting AMPK activation

Vascular calcification (VC) is a characteristic feature in patients with diabetes mellitus (DM) and is closely associated with the osteogenic differentiation of vascular smooth muscle cells (VSMCs). Ubiquitin-Specific Protease 10 (USP10) has been shown to regulate multiple cellular processes; however, its relationship with diabetic VC remains unclear. This study aims to elucidate the role of USP10 in VC development and the underlying regulatory mechanisms. Nε-carboxymethyl lysine (CML) was significantly increased in calcified ateries from diabetic atherosclerosis ApoE−/− mice fed with high-fat diets. CML downregulated USP10 expression in VSMCs and calcified mice coronary arteries, as assessd by Western blotting, RT-qPCR,immunofluorescence and immunohistochemistry. Loss-and gain-of-function experiments were conducted both in vitro and in vivo to verify the biological functions of USP10. Ectopic expression of USP10 mitigated the severity of VC. With regard to the mechanism, the interaction between USP10 and AMPKα was investigated through double-label immunofluorescence and Co-immunoprecipitation. In vitro ubiquitination assay revealed that USP10 was capable of mediating AMPKα ubiquitination and caused increased AMPKα phosphorylation level at Thr172. Moreover, the anticalcification effect of USP10 was reversed by pharmacological inhibition of AMPK signaling pathway. The current fundings suggest an important role of USP10 in diabetic VC progression, at least in part, via mediating the ubiquitination and activation of AMPKα. USP10 may serve as a novel therapeutic target for the treatment of diabetic VC.

Concentration-Dependent Effects of Boric Acid on Osteogenic Differentiation of Vascular Smooth Muscle Cells.

Vascular calcification can be triggered by oxidative stress and inflammation. Although boron possesses antioxidant and anti-inflammatory properties, its effect on osteogenic differentiation of vascular smooth muscle cells (VSMCs) has yet to be examined. Therefore, we aimed to investigate the effect of boric acid (BA), the main form of boron in body fluids, on the osteogenic differentiation of VSMCs. Following the isolation of VSMCs, the effects of BA on cell proliferation were determined by MTT. The impact of various BA concentrations on the osteogenic differentiation of VSMCs was evaluated by Alizarin red S and alkaline phosphatase (ALP) stainings and the o-cresolphthalein complexone method. In addition, mRNA expressions of osteogenic-related (Runx2 and ALP) and antioxidant system-related genes (Nrf2 and Nqo1) were detected using qRT-PCR analysis. BA treatments did not alter the proliferation of VSMCs. Osteogenic differentiation of VSMCs treated with 100 and 500μM BA (moderate and high plasma concentrations) was no different from untreated cells. However, increased osteogenic differentiation was observed with the lowest blood level (2μM) and extremely high BA concentration (1000μM). Consistent with these results, mRNA expression of Runx2 increased with 2 and 1000μM BA treatments, while Nrf2 and Nqo1 expressions increased significantly with 100 and 500μM BA. BA has different effects on VSMCs at various concentrations. The low blood level and too high BA concentration appear detrimental as they increase the osteogenic differentiation of VSMCs in vitro. We propose to investigate BA's effects and mechanism of action on vascular calcification in vivo.

Abstract 3145: Inactivating The Adenosine 2A Receptor Reduces Vascular Calcification Through Modulating Osteogenic Differentiation Of Vascular Cells

Background and Aims: Vascular calcification (VC), a major contributor to cardiovascular morbidity and mortality particularly in patients with diabetes and chronic kidney disease (CKD), is an active cell-driven process involving osteogenic differentiation of vascular cells. Adenosine 2A receptor (ADORA2A) is highly expressed in vascular cells and associated with coronary artery disease; its role in VC remains unclear. This study aims to investigate the effects of ADORA2A on VC and evaluate whether ADORA2A is a potential therapeutic target for VC. Methods: Cultured vascular cells and mouse aortas were treated with osteogenic medium (OM) to establish in vitro and ex vivo models. VC in mice was induced by a combination of 5/6 th nephrectomy, a high phosphate diet, and a vitamin D supplement. The effects of ADORA2A on vascular calcification were evaluated by calcium deposition, alkaline phosphatase activity, and changes of osteogenic markers and vascular phenotypic markers. Results: ADORA2A expression was upregulated in OM-treated vascular cells and aortas, aortas of CKD mice, and calcified tibial arteries of patients. Mice with Adora2a global or vascular-specific deficiency or treatment with an ADORA2A pharmacological antagonist displayed attenuated calcium deposition and decreased expression of osteogenic markers in calcified aortas. The same findings were observed in in vitro and ex vivo assays. Mechanistically, ADORA2A-mediated osteogenic differentiation in vascular cells was mediated by hypoxia-inducible factor-1A (HIF1A). Conclusion: ADORA2A inactivation mitigates osteogenic differentiation of vascular cells and aortic calcification by downregulating HIF1A activation; therefore, blocking ADORA2A holds promise for treating VC.

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.

Oxidized phospholipid POVPC contributes to vascular calcification by triggering ferroptosis of vascular smooth muscle cells.

Vascular calcification is an actively regulated biological process resembling bone formation, and osteogenic differentiation of vascular smooth muscle cells (VSMCs) plays a crucial role in this process. 1-Palmitoyl-2-(5'-oxo-valeroyl)-sn-glycero-3-phosphocholine (POVPC), an oxidized phospholipid, is found in atherosclerotic plaques and has been shown to induce oxidative stress. However, the effects of POVPC on osteogenic differentiation and calcification of VSMCs have yet to be studied. In the present study, we investigated the role of POVPC in vascular calcification using invitro and exvivo models. POVPC increased mineralization of VSMCs and arterial rings, as shown by alizarin red staining. In addition, POVPC treatment increased expression of osteogenic markers Runx2 and BMP2, indicating that POVPC promotes osteogenic transition of VSMCs. Moreover, POVPC increased oxidative stress and impaired mitochondria function of VSMCs, as shown by increased ROS levels, impairment of mitochondrial membrane potential, and decreased ATP levels. Notably, ferroptosis triggered by POVPC was confirmed by increased levels of intracellular ROS, lipid ROS, and MDA, which were decreased by ferrostatin-1, a ferroptosis inhibitor. Furthermore, ferrostatin-1 attenuated POVPC-induced calcification of VSMCs. Taken together, our study for the first time demonstrates that POVPC promotes vascular calcification via activation of VSMC ferroptosis. Reducing the levels of POVPC or inhibiting ferroptosis might provide a novel strategy to treat vascular calcification.

Alternative Methods for the Detection of Superoxide Anion Generation in Platelets.

Reactive oxygen species (ROS) are highly unstable oxygen-containing molecules. Their chemical instability makes them extremely reactive and gives them the ability to react with important biological molecules such as proteins, nucleic acids, and lipids. Superoxide anions are important ROS generated by the reduction of molecular oxygen reduction (i.e., acquisition of one electron). Despite their initial implication exclusively in aging, degenerative, and pathogenic processes, their participation in important physiological responses has recently become apparent. In the vascular system, superoxide anions have been shown to modulate the differentiation and function of vascular smooth muscle cells, the proliferation and migration of vascular endothelial cells in angiogenesis, the immune response, and the activation of platelets in hemostasis. The role of superoxide anions is particularly important in the dysregulation of platelets and the cardiovascular complications associated with a plethora of conditions, including cancer, infection, inflammation, diabetes, and obesity. It has, therefore, become extremely relevant in cardiovascular research to be able to effectively measure the generation of superoxide anions byhuman platelets,understand the redox-dependent mechanisms regulating the balance between hemostasis and thrombosis and, eventually,identify novel pharmacological tools for the modulation of platelet responses leading to thrombosis and cardiovascular complications. This study presents three experimental protocols successfully adopted for the detection of superoxide anions in platelets and the study of the redox-dependent mechanisms regulating hemostasis and thrombosis: 1) dihydroethidium (DHE)-based superoxide anion detection by flow cytometry; 2) DHE-based superoxide anion visualization and analysis by single platelet imaging; and 3) spin probe-based quantification of superoxide anion output in platelets by electron paramagnetic resonance (EPR).

Heterogeneity and Differentiation of the Human Arterial Tree: Focus on microRNA Expression in Vascular Disease.

Human arteries show structural and functional peculiarities according to the nutrient and oxygen needs of a specific vascular district. This architectural heterogeneity is reflected in the pathological setting of cardiovascular diseases (CVDs). Indeed, the responsiveness to cardiovascular risk factors, and the morphological and molecular patterns are discriminating factors among CVDs affecting different vascular beds. MicroRNAs (miRNAs) are endogenous regulators of gene expression and fine-tuners of vascular cell differentiation; thus, these non-coding RNAs can modulate arterial heterogeneity. The identification of an artery-specific miRNA signature would be promising in the therapy of CVDs, especially in patients who are frail and elderly. In the present review, we will provide a concise description of the arterial tree heterogeneity on a structural and cellular basis, mainly in the pathological context. Secondly, we will address the miRNA potential as crucial mediators of arterial heterogeneity, focusing on the abdominal aorta and femoral artery, with the final goal of strengthening the search for more targeted therapies in CVDs and stratification approaches in patients who are frail and elderly.

Hypomethylation of the LncRNA H19 promoter accelerates osteogenic differentiation of vascular smooth muscle cells by activating the Erk1/2 pathways.

Vascular calcification is a common chronic kidney disease complication. This study aimed to investigate the function of long non-coding RNA (LncRNA) H19 in vascular calcification to explore new therapeutic strategies. We induced osteogenic differentiation and calcification of vascular smooth muscle cells (VSMCs) using β-glycerophosphate. Then, we detected the LncRNA H19 promoter methylation status and Erk1/2 pathways using methylation-specific polymerase chain reaction and western blotting, respectively. Compared with the control group, high phosphorus levels induced VSMC calcification, accompanied by increases in LncRNA H19 and the osteogenic marker Runx2 and reduction of the contractile phenotype marker SM22a. LncRNA H19 knockdown inhibited osteogenic differentiation and calcification of VSMCs. However, the suppressed role of VSMC calcification caused by shRNA H19 was partially reversed by simultaneous activation of the Erk1/2 pathways. Mechanically, we found that the methylation rate of CpG islands in the LncRNA H19 promoter region was significantly lower in the high-phosphorus group, and the hypomethylation state elevated LncRNA H19 levels, which in turn regulated phosphorylated Erk1/2 expression. LncRNA H19 promoted osteogenic differentiation and calcification of VSMCs by regulating the Erk1/2 pathways. Additionally, hypomethylation of LncRNA H19 promoter CpG islands upregulated LncRNA H19 levels and subsequently activated Erk1/2 phosphorylation.

Overexpression of miR-204-5p Alleviates Osteogenic Differentiation and Calcification of Human Aortic Vascular Smooth Muscle Cells by Targeting Calcium/Calmodulin-dependent Protein Kinase 1.

Vascular calcification (VC), a major complication in chronic kidney disease (CKD), is predominantly driven by osteoblastic differentiation. Recent studies have highlighted the crucial role of microRNAs in CKD's pathogenesis. Here, our research focused on the effects of miR-204-5p and its molecular mechanisms within VC. We initially found a notable decrease in miR-204-5p levels in human aortic vascular smooth muscle cells stimulated with inorganic phosphate, using this as a VC model in vitro. Following the overexpression of miR-204-5p, a decrease in VC was observed, as indicated by alizarin red S staining and measurements of calcium content. This decrease was accompanied by lower levels of the osteogenic marker, runt-related transcription factor 2, and higher levels of α-smooth muscle actin, a marker of contractility. Further investigation showed that calcium/calmodulin-dependent protein kinase 1 (CAMK1), which is a predicted target of miR-204-5p, promotes VC. Conversely, overexpressing miR-204-5p reduced VC by suppressing CAMK1 activity. Overexpressing miR-204-5p also effectively mitigated aortic calcification in an in vivo rat model. In summary, our research indicated that targeting the miR-204-5p/CAMK1 pathway could be a viable strategy for mitigating VC in CKD patients.

Knockdown of ANGPTL4 inhibits adipogenesis of preadipocyte via autophagy.

It has been demonstrated that angiopoietin-like protein 4 (ANGPTL4) plays an important regulatory role in lipid metabolism and backfat deposition appears to vary in different pig breeds. However, the correlation between ANGPTL4 and backfat deposition have not been well characterized and the role of ANGPTL4 in regulating adipogenesis remains unclear. Therefore, this study aimed to investigate correlation between ANGPTL4 and backfat deposition and to explore the effects of ANGPTL4 on preadipocyte differentiation and the underlying mechanism. Our results showed that the backfat thickness and the ANGPTL4 gene expression of Laiwu pigs were significantly higher than those in DLY pigs and the ANGPTL4 gene expression was positively correlated with backfat thickness both in DLY pigs and Laiwu pigs. Moreover, an increase in ANGPTL4 expression and activation of autophagy were observed during the differentiation of stromal vascular fraction cells. In addition, knockdown of ANGPTL4 inhibited the differentiation of 3T3-L1 cells with decreased expression of LC3-II and ATG5 and increased expression of SQSTM1, suggesting the involvement of autophagy in ANGPTL4-mediated adipogenesis. In conclusion, these results suggested that ANGPTL4 is positively correlated with backfat deposition in pigs and knockdown of ANGPTL4 inhibits adipogenesis of preadipocyte via autophagy, providing new insights into the regulation of fat deposition and to improve the carcass quality and meat quality of porcine.

Growth-regulating factor 15-mediated vascular cambium differentiation positively regulates wood formation in hybrid poplar (Populus alba × P. glandulosa).

Hybrid poplars are industrial trees in China. An understanding of the molecular mechanism underlying wood formation in hybrid poplars is necessary for molecular breeding. Although the division and differentiation of vascular cambial cells is important for secondary growth and wood formation, the regulation of this process is largely unclear. In this study, mPagGRF15 OE and PagGRF15-SRDX transgenic poplars were generated to investigate the function of PagGRF15. RNA-seq and qRT-PCR were conducted to analyze genome-wide gene expression, while ChIP‒seq and ChIP-PCR were used to identified the downstream genes regulated by PagGRF15. We report that PagGRF15 from hybrid poplar (Populus alba × P. glandulosa), a growth-regulating factor, plays a critical role in the regulation of vascular cambium activity. PagGRF15 was expressed predominantly in the cambial zone of vascular tissue. Overexpression of mPagGRF15 (themutated version of GRF15 in the miR396 target sequence) in Populus led to decreased plant height and internode number. Further stem cross sections showed that the mPagGRF15 OE plants exhibited significant changes in vascular pattern with an increase in xylem and a reduction in phloem. In addition, cambium cell files were decreased in the mPagGRF15 OE plants. However, dominant suppression of the downstream genes of PagGRF15 using PagGRF15-SRDX showed an opposite phenotype. Based on the RNA-seq and ChIP-seq results, combining qRT-PCR and ChIP-PCR analysis, candidate genes, such as WOX4b, PXY and GID1.3, were obtained and found to be mainly involved in cambial activity and xylem differentiation. Accordingly, we speculated that PagGRF15 functions as a positive regulator mediating xylem differentiation by repressing the expression of the WOX4a and PXY genes to set the pace of cambial activity. In contrast, PagGRF15 mediated the GA signaling pathway by upregulating GID1.3 expression to stimulate xylem differentiation. This study provides valuable information for further studies on vascular cambium differentiation mechanisms and genetic improvement of the specific gravity of wood in hybrid poplars.

Circulating miR-129-3p in combination with clinical factors predicts vascular calcification in hemodialysis patients.

Vascular calcification (VC) commonly occurs and seriously increases the risk of cardiovascular events and mortality in patients with hemodialysis. For optimizing individual management, we will develop a diagnostic multivariable prediction model for evaluating the probability of VC. The study was conducted in four steps. First, identification of miRNAs regulating osteogenic differentiation of vascular smooth muscle cells (VSMCs) in calcified condition. Second, observing the role of miR-129-3p on VC in vitro and the association between circulating miR-129-3p and VC in hemodialysis patients. Third, collecting all indicators related to VC as candidate variables, screening predictors from the candidate variables by Lasso regression, developing the prediction model by logistic regression and showing it as a nomogram in training cohort. Last, verifying predictive performance of the model in validation cohort. In cell experiments, miR-129-3p was found to attenuate vascular calcification, and in human, serum miR-129-3p exhibited a negative correlation with vascular calcification, suggesting that miR-129-3p could be one of the candidate predictor variables. Regression analysis demonstrated that miR-129-3p, age, dialysis duration and smoking were valid factors to establish the prediction model and nomogram for VC. The area under receiver operating characteristic curve of the model was 0.8698. The calibration curve showed that predicted probability of the model was in good agreement with actual probability and decision curve analysis indicated better net benefit of the model. Furthermore, internal validation through bootstrap process and external validation by another independent cohort confirmed the stability of the model. We build a diagnostic prediction model and present it as an intuitive tool based on miR-129-3p and clinical indicators to evaluate the probability of VC in hemodialysis patients, facilitating risk stratification and effective decision, which may be of great importance for reducing the risk of serious cardiovascular events.