Dickkopf-1 promotes vascular smooth muscle cell foam cell formation and atherosclerosis development through CYP4A11/SREBP2/ABCA1.

Vascular smooth muscle cells (VSMCs) are considered to be a crucial source of foam cells in atherosclerosis due to their low expression level of cholesterol exporter ATP-binding cassette transporter A1 (ABCA1) intrinsically. While the definite regulatory mechanisms are complicated and have not yet been fully elucidated, we previously reported that Dickkopf-1 (DKK1) mediates endothelial cell (EC) dysfunction, thereby aggravating atherosclerosis. However, the role of smooth muscle cell (SMC) DKK1 in atherosclerosis and foam cell formation remains unknown. In this study, we established SMC-specific DKK1-knockout (DKK1SMKO ) mice by crossbreeding DKK1flox/flox mice with TAGLN-Cre mice. Then, DKK1SMKO mice were crossed with APOE-/- mice to generate DKK1SMKO /APOE-/- mice, which exhibited milder atherosclerotic burden and fewer SMC foam cells. In vitro loss- and gain-of-function studies of DKK1 in primary human aortic smooth muscle cells (HASMCs) have proven that DKK1 prevented oxidized lipid-induced ABCA1 upregulation and cholesterol efflux and promoted SMC foam cell formation. Mechanistically, RNA-sequencing (RNA-seq) analysis of HASMCs as well as chromatin immunoprecipitation (ChIP) experiments showed that DKK1 mediates the binding of transcription factor CCAAT/enhancer-binding protein delta (C/EBPδ) to the promoter of cytochrome P450 epoxygenase 4A11 (CYP4A11) to regulate its expression. In addition, CYP4A11 as well as its metabolite 20-HETE-promoted activation of transcription factor sterol regulatory element-binding protein 2 (SREBP2) mediated the DKK1 regulation of ABCA1 in SMC. Furthermore, HET0016, the antagonist of CYP4A11, has also shown an alleviating effect on atherosclerosis. In conclusion, our results demonstrate that DKK1 promotes SMC foam cell formation during atherosclerosis via a reduction in CYP4A11-20-HETE/SREBP2-mediated ABCA1 expression.

Comparisons between needle puncture and chondroitinase ABC to induce intervertebral disc degeneration in rabbits.

PURPOSE: This study aimed to compare the effect of needle puncture and chondroitinase ABC (ChABC) injection on inducing intervertebral disc (IVD) degeneration (IVDD) in rabbits. METHODS: Sixteen New Zealand white rabbits were used in this study. Briefly, the rabbits were divided into four groups. In the annulus fibrosis (AF) needle puncture group, a 16-G needle was used to puncture the L5-6 and L6-7 IVDs, while in the sham group, these IVDs were not punctured. In the ChABC group, 30 µL 0.5 Unit/mL ChABC was injected into L5-6 and L6-7 IVDs using a 26-G needle, while in the vehicle group, these IVDs were injected with 30 µL phosphate-buffered saline (PBS). X-ray and MRI scans were performed at the 4th, 12th and 16th weeks postoperatively. Histological, immunohistochemical and biochemical analyses were performed at the 16th week postoperatively. RESULTS: Both needle puncture and ChABC successfully established IVDD in rabbits at 4th, 12th and 16th weeks, confirmed by X-ray and MRI scan. The progression of IVDD went in a time-dependent manner. The IVDD in the ChABC group was less severe than in the needle puncture group throughout the study. Aggrecan and type II collagen significantly decreased, while tumor necrosis factor-α and superoxide dismutase 2 increased in the needle puncture and ChABC groups, compared with the sham and PBS groups. CONCLUSIONS: Both AF needle puncture and ChABC injection can successfully induce IVDD in rabbits. Compared with ChABC injection, AF needle puncture can induce more severe IVDD.

Locking stand-alone cage versus anterior plate construct in anterior cervical discectomy and fusion: a systematic review and meta-analysis based on randomized controlled trials.

PURPOSE: To evaluate the efficacy of locking stand-alone cage (LSC) compared with anterior plate construct (APC) in anterior cervical discectomy and fusion (ACDF). METHODS: A comprehensive literature search was carried out in PubMed, Embase, Web of Science, and Cochrane Library to screen randomized controlled trials (RCTs) that directly compared LSC with APC in ACDF. The Cochrane Collaboration's tool was used for assessment of study quality. Data were analyzed with the Review Manager 5.3 software. RESULTS: A total of seven RCTs were included. The results revealed no significant differences between LSC and APC in ACDF regarding the fusion rate, Japanese Orthopaedic Association score, visual analogue scale score, neck disability index score, hospital stay, subsidence rate, cervical lordosis, segmental Cobb angle, and disc height. However, LSC was associated with a significantly shorter operation time, less blood loss, lower overall incidence of dysphagia, and lower adjacent-level ossification (ALO) rate compared with APC. CONCLUSION: In summary, LSC is not only a safe and effective device for ACDF but also has the advantages of significantly reduced operation time, blood loss, overall incidence of dysphagia, and ALO rate over APC. Therefore, LSC is a better alternative than APC for the patients undergoing ACDF procedures.

The inflammatory cytokine TNF-α regulates the biological behavior of rat nucleus pulposus mesenchymal stem cells through the NF-κB signaling pathway in vitro.

Nucleus pulposus (NP) mesenchymal stem cells (NPMSCs) are a potential cell source for intervertebral disc (IVD) regeneration; however, little is known about their response to tumor necrosis factor-α (TNF-α), a critical inflammation factor contributing to accelerating IVD degeneration. Accordingly, the aim of this study was to investigate the regulatory effects of TNF-α at high and low concentrations on the biological behaviors of healthy rat NPMSCs, including proliferation, migration, and NP differentiation. In this study, NPMSCs were treated with different concentration of TNF-α (0-200 ng/mL). Then we used annexin V/propidium iodide flow cytometry analysis to detect the apoptosis rate of NPMSCs. Cell Counting Kit-8, Edu assay, and cell cycle test were used to examine the proliferation of NPMSCs. Migration ability of NPMSCs was detected by wound healing assay and transwell migration assay. Pellets method was used to induce NP differentiation of NPMSCs, and immunohistochemical staining, real-time polymerase chain reaction, and Western blot analysis were used to examine the NPC phenotypic genes and proteins. The cells were further treated with the nuclear factor-κB (NF-κB) pathway inhibitor Bay 11-7082 to determine the role of the NF-κB pathway in the mechanism underlying the differentiation process. Results showed that treatment with a high concentration of TNF-α (50-200 ng/mL) could induce apoptosis of NPMSCs, whereas a relatively low TNF-α concentration (0.1-10 ng/mL) promoted the proliferation and migration of NPMSCs, but inhibited their differentiation toward NP cells. Moreover, we identified that the NF-κB signaling pathway is activated during the TNF-α-inhibited differentiation of NPMSCs, and the NF-κB signal inhibitor Bay 11-7082 could partially eliminate the adverse effect of TNF-α on the differentiation of NPMSCs. Therefore, our findings provide important insight into the dynamic biological behavior reactivity of NPMSCs to TNF-α during IVD degeneration process, thus may help us understanding the underlying mechanism of IVD degeneration.

Successful catheter ablation of atrial fibrillation improves but not reverses the abnormalities of left atrial mechanics and energy loss.

BACKGROUND: Dissipative energy loss (EL), a new index to quantify the inefficient blood flow, has not been explored within left atrium (LA) in patients with atrial fibrillation (AF). We aimed to study the intra-atrial flow and mechanics in patients with AF before and after successful catheter ablation by evaluating EL and LA global longitudinal strain (LAS). METHODS: In our study, there were 53 patients undergoing catheter ablation for AF at baseline (AF group) and 33 age- and sex-matched controls. They were both assessed of LA EL using vector flow mapping (VFM) and of LAS using two-dimensional tracking (2DTT) during systole (sys), early diastole (ed), and atrial contraction phase (ac). Out of 53 patients, 37 patients who sustained sinus rhythm and carried out the echocardiographic examination at 3 and 6 months follow-up were evaluated of change in EL and LAS. The independent predictors of EL during three phases in AF group were performed using stepwise multivariate linear regression analyses. RESULTS: Left atrium EL and LAS among all phases in AF group were significantly lower than controls (all P < 0.01). During follow-up, LASsys and LASac both significantly improved at 3 and 6 months (both P < 0.01), and ELac significantly increased after 6 months (P < 0.05); ELsys, ELed and LASed were no significant change; EL and LAS among all phases were no normalized during follow-up. The independent predictors of EL were: for ELsys, BSA (P = 0.004) and LASac (P = 0.025); for ELed, E (P = 0.001) and A (P = 0.014); for ELac, E/A (P < 0.001). CONCLUSION: Vector flow mapping and 2DTT revealed impaired intra-atrial flow and mechanics. Successful catheter ablation for AF slightly improves but not reverses the aforementioned impairment, indicating the continuous LA dysfunction.

TWEAK/Fn14 mediates atrial-derived HL-1 myocytes hypertrophy via JAK2/STAT3 signalling pathway.

Atrial myocyte hypertrophy is one of the most important substrates in the development of atrial fibrillation (AF). The TWEAK/Fn14 axis is a positive regulator of cardiac hypertrophy in cardiomyopathy. This study therefore investigated the effects of Fn14 on atrial hypertrophy and underlying cellular mechanisms using HL-1 atrial myocytes. In patients with AF, Fn14 protein levels were higher in atrial myocytes from atrial appendages, and expression of TWEAK was increased in peripheral blood mononuclear cells, while TWEAK serum levels were decreased. In vitro, Fn14 expression was up-regulated in response to TWEAK treatment in HL-1 atrial myocytes. TWEAK increased the expression of ANP and Troponin T, and Fn14 knockdown counteracted the effect. Inhibition of JAK2, STAT3 by specific siRNA attenuated TWEAK-induced HL-1 atrial myocytes hypertrophy. In conclusion, TWEAK/Fn14 axis mediates HL-1 atrial myocytes hypertrophy partly through activation of the JAK2/STAT3 pathway.

Functional Self-Assembled Peptide Nanofibers for Bone Marrow Mesenchymal Stem Cell Encapsulation and Regeneration in Nucleus Pulposus.

Low back pain (LBP) is mainly caused by intervertebral disc degeneration (IDD). Recent studies have demonstrated that the transplantation of mesenchymal stem cells (MSCs) can regenerate regions that have undergone degeneration, and the regenerative effect can be enhanced by using a hydrogel carrier. This article describes an injectable functional hydrogel system manufactured by combining RADA16-I and RADA-KPSS (RADA-KPSS was manufactured by conjugating a bioactive motif derived from BMP-7 [KPSS] onto the C terminal of RADA16-I) at a volume ratio of 1:1. This hydrogel system can enhance the proliferation, differentiation, and chemotactic migration of BMSCs. In addition, the encapsulation of BMSCs with this system maintains cell viability for a long period after transplantation into an ex vivo cultured disc model. In conclusion, KPSS-conjugated RADKPS is an ideal encapsulation system for BMSCs in intervertebral disc (IVD) regeneration.

Systematic Review of Treatment for Unruptured Intracranial Aneurysms: Clipping Versus Coiling.

AIM: To compare endovascular coiling and surgical clipping for the evaluation of clinical outcomes in patients with unruptured intracranial aneurysms. MATERIAL AND METHODS: We searched MEDLINE, EMBASE, the Cochrane Library and three Chinese domestic electronic databases, namely, Wanfang, CNKI and VIP for studies published between January 1990 and January 2018. We included controlled clinical studies comparing clinical outcomes between surgical clipping and endovascular coiling treatments. Two researchers extracted the data and assessed the quality of the studies, and a meta-analysis was performed using RevMan 5 software. RESULTS: We analysed a total of 23 controlled clinical studies including 117,796 cases. Meta-analysis demonstrated similar ischaemia rates between clipping and coiling with an odds ratio [OR] of 1.36 (95% CI: 0.77?2.40). The occlusion rate and bleeding risk were higher with clipping than coiling; the pooled ORs were 5.31 (95% CI: 3.07?9.19) and 2.39 (95% CI: 1.82?3.13), respectively. In addition, clipping resulted in a longer hospital stay (OR = 2.90, 95% CI: 2.14?3.65) than coiling did. Patients who underwent clipping had a higher short-term mortality (OR = 1.99, 95% CI: 1.70?2.33) and neurological deficit rate (OR = 2.05, 95% CI: 1.73? 2.44) compared with those who underwent coiling. However, 1 year mortality and deficit rate were similar for both clipping and coiling, with pooled ORs of 0.75 (95% CI: 0.41?1.38) and 0.94 (95% CI: 0.53?1.67), respectively. Funnel plots did not demonstrate a publication bias, with the exception of ischaemic outcome, and sensitivity analysis showed consistent results. CONCLUSION: Our study demonstrates that coiling is associated with a lower rate of occlusion, shorter hospital stay, lower bleeding risk and lower short-term mortality and morbidity compared with clipping. In terms of ischaemic risk, 1 year mortality and morbidity, coiling and clipping bear a similar risk. In addition, we speculate that surgical clipping may have a better outcome than endovascular coiling in the long term especially in young patients. Further research is needed to confirm our conclusion.

Value of carotid intima thickness in assessing advanced carotid plaque vulnerability: a study based on carotid artery ultrasonography and carotid plaque histology.

Background: Research has shown that carotid intima-media thickness (CIMT) could help to predict carotid plaque (CP) progression in patients with mild carotid stenosis. However, the debate continues as to the value of carotid intima thickness (CIT) in monitoring the development of CP in patients with severe carotid stenosis. This study sought to evaluate the relationships between CIT and the ultrasonic characteristics of CP and to analyze the value of CIT and the ultrasonic parameters of CP in assessing plaque vulnerability in advanced human carotid atherosclerosis. Methods: A total of 55 individuals who underwent carotid endarterectomy (CEA) were included in the study (mean age: 65±7 years; female: 9.1%). CIMT and CIT were examined at the common carotid artery (CCA). Plaque textural features, such as the gray-scale median (GSM), superb microvascular imaging (SMI) level, and total plaque area (TPA), were also identified. A Spearman correlation coefficient analysis was performed to examine the relationship between CIT and the ultrasonic parameters of CP. The CIT of various plaque types was compared. Receiver operating characteristic (ROC) curves were used to analyze the diagnostic values of the ultrasound characteristics to evaluate CP vulnerability. Results: The mean CIT of all the participants was 0.382±0.095 mm, the mean CIT of the participants with stable plaques was 0.328±0.031 mm, and the mean CIT of participants with vulnerable plaques was 0.424±0.106 mm (P<0.001). CIT was associated with the SMI level (Spearman's correlation coefficient: r=0.392, P=0.005), TPA (Spearman's correlation coefficient: r=0.337, P=0.012). Patients with thicker CIT had larger lipid cores, higher levels of plaque vulnerability, and more intraplaque hemorrhages (IPHs). The areas under the ROCs (AUCs) with 95% confidence interval (CI) for CIMT, CIT, the SMI level, the GSM, the TPA, and the combined model for identifying vulnerable plaques were 0.673 (0.533-0.793), 0.849 (0.727-0.932), 0.771 (0.629-0.879), 0.669 (0.529-0.790), 0.858 (0.738-0.938), and 0.949 (0.854-0.990), respectively. Conclusions: CIT was associated with both the histology and ultrasonic features of CP. CIT may be helpful in the detection of severe CP development.

Dapagliflozin alleviates right heart failure by promoting collagen degradation by reducing ROS levels.

BACKGROUND: Right ventricular (RV) fibrosis is an important pathological change that occurs during the development of right heart failure (RHF) induced by pulmonary hypertension (PH). Dapagliflozin (DAPA), a sodium-glucose cotransporter 2 (SGLT2) inhibitor, has been shown to play a major role in left heart failure, but it is unclear whether it has a positive effect on RHF. This study aimed to clarify the effect of DAPA on PH-induced RHF and investigate the underlying mechanisms. METHODS: We conducted experiments on two rat models with PH-induced RHF and cardiac fibroblasts (CFs) exposed to pathological mechanical stretch or transforming growth factor-beta (TGF-ß) to investigate the effect of DAPA. RESULTS: In vivo, DAPA could improve pulmonary hemodynamics and RV function. It also attenuated right heart hypertrophy and RV fibrosis. In vitro, DAPA reduced collagen expression by increasing the production of matrix metalloproteinase 2 (MMP2) and matrix metalloproteinase 9 (MMP9). Additionally, DAPA was found to reduce reactive oxygen species (ROS) levels in CFs and the right heart in rats. Similar to DAPA, the ROS scavenger N-acetylcysteine (NAC) exerted antifibrotic effects on CFs. Therefore, we further investigated the mechanism by which DAPA promoted collagen degradation by reducing ROS levels. CONCLUSIONS: In summary, we concluded that DAPA ameliorated PH-induced structural and functional changes in the right heart by increasing collagen degradation. Our study provides new ideas for the possibility of using DAPA to treat RHF.

Photoregulatory protein kinases fine-tune plant photomorphogenesis by directing a bifunctional phospho-code on HY5 in Arabidopsis.

Photomorphogenesis is a light-dependent plant growth and development program. As the core regulator of photomorphogenesis, ELONGATED HYPOCOTYL 5 (HY5) is affected by dynamic changes in its transcriptional activity and protein stability; however, little is known about the mediators of these processes. Here, we identified PHOTOREGULATORY PROTEIN KINASE 1 (PPK1), which interacts with and phosphorylates HY5 in Arabidopsis, as one such mediator. The phosphorylation of HY5 by PPK1 is essential to establish high-affinity binding with B-BOX PROTEIN 24 (BBX24) and CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), which inhibit the transcriptional activity and promote the degradation of HY5, respectively. As such, PPKs regulate not only the binding of HY5 to its target genes under light conditions but also HY5 degradation when plants are transferred from light to dark. Our data identify a PPK-mediated phospho-code on HY5 that integrates the molecular mechanisms underlying the regulation of HY5 to precisely control plant photomorphogenesis.

Endothelial Dickkopf-1 Promotes Smooth Muscle Cell-derived Foam Cell Formation via USP53-mediated Deubiquitination of SR-A During Atherosclerosis.

Background: Shear stress-induced Dickkopf-1 (DKK1) secretion by endothelial cells (ECs) promotes EC dysfunction and accelerates atherosclerosis (AS). However, the paracrine role of endothelial DKK1 in modulating adjacent smooth muscle cells (SMCs) in atherosclerosis remains unclear. This study investigated the role of EC-secreted DKK1 in SMC-derived foam cell formation under shear stress, in vitro and in vivo. Methods: Parallel-plate co-culture flow system was used to explore the cellular communication between ECs and SMCs under shear stress in vitro. Endothelium-specific knockout of DKK1 (DKK1ECKO/APOE-/-) and endothelium-specific overexpression of DKK1 (DKK1ECTg) mice were constructed to investigate the role of endothelial DKK1 in atherosclerosis and SMC-derived foam cell formation in vivo. RNA sequencing (RNA-seq) was used to identify the downstream targets of DKK1. Reverse transcription quantitative polymerase chain reaction (RT-qPCR), western blot, coimmunoprecipitation (Co-IP) assays and chromatin immunoprecipitation (ChIP) experiments were conducted to explore the underlying regulatory mechanisms. Results: DKK1 is transcriptionally upregulated in ECs under conditions of low shear stress, but not in co-cultured SMCs. However, DKK1 protein in co-cultured SMCs is increased via uptake of low shear stress-induced endothelial DKK1, thereby promoting lipid uptake and foam cell formation in co-cultured SMCs via the post-translational upregulation of scavenger receptor-A (SR-A) verified in parallel-plate co-culture flow system, DKK1ECKO and DKK1ECTg mice. RNA sequencing revealed that DKK1-induced SR-A upregulation in SMCs is dependent on Ubiquitin-specific Protease 53 (USP53), which bound to SR-A via its USP domain and cysteine at position 41, exerting deubiquitination to maintain the stability of the SR-A protein by removing the K48 ubiquitin chain and preventing proteasomal pathway degradation, thereby mediating the effect of DKK1 on lipid uptake in SMCs. Moreover, DKK1 regulates the transcription of USP53 by facilitating the binding of transcription factor CREB to the USP53 promoter. SMC-specific overexpression of USP53 via adeno-associated virus serotype 2 vectors in DKK1ECKO/APOE-/- mice reversed the alleviation of atherosclerotic plaque burden, SR-A expression and lipid accumulation in SMCs within plaques resulting from DKK1 deficiency. Conclusions: Our findings demonstrate that, endothelial DKK1, induced by pathological low shear stress, acts as an intercellular mediator, promoted the foam cell formation of SMCs. These results suggest that targeted intervention with endothelial DKK1 may confer beneficial effects on atherosclerosis.

Proposal of optically tunable and reconfigurable multi-channel bandstop filter using sum-frequency generation in a PPLN waveguide.

A multi-wavelength bandstop filter is proposed and numerically demonstrated using the sum-frequency generation (SFG) process in a waveguide of periodically poled lithium niobate (PPLN). This proposed device achieves channels number reconfigurable, central filtering wavelength of each filtering channel independently tunable and extinction ratios (ERs) equalized via all-optical methods.

[Retracted] MicroRNA­202 inhibits cell proliferation, migration and invasion of glioma by directly targeting metadherin.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the panels shown for the cell invasion assays in Figs. 2C and 6C were strikingly similar to data appearing in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had were already under consideration for publication prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. The authors were asked for an explanation to account for these concerns, but the Editorial Office did not receive a reply. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 18: 1670­1678, 2017; DOI: 10.3892/or.2017.5815].

Dickkopf1 (Dkk1) Alleviates Vascular Calcification by Regulating the Degradation of Phospholipase D1 (PLD1).

Vascular calcification (VC) is a significant risk factor for cardiovascular mortality and morbidity in patients with atherosclerosis (AS), chronic kidney disease, and diabetes. Dickkopf1 (Dkk1) is a multifunctional secreted glycoprotein that has been explored as a novel potential antitumor target. Recently, Dkk1 was shown to be closely associated with AS development. However, the role of Dkk1 in VC remains elusive. In this study, we explored the role and molecular mechanisms of Dkk1 in VC based on a smooth muscle-specific Dkk1-knockout (Dkk1SMKO) mouse model. Our data indicated that Dkk1 expression was decreased under calcifying conditions and that Dkk1 overexpression alleviated high phosphate-induced vascular calcification. In vivo, smooth muscle Dkk1-specific knockout aggravated vascular calcification in mice. However, phospholipase D1 (PLD1) overexpression partially weakened the protective effect of Dkk1 against vascular calcification. Mechanistically, Dkk1 slowed vascular calcification by promoting the degradation of PLD1 via the regulating autophagosome formation and maturation. In conclusion, we found that Dkk1 could alleviate vascular calcification by regulating the degradation of PLD1.

Mechanical stretch aggravates vascular smooth muscle cell apoptosis and vascular remodeling by downregulating EZH2.

BACKGROUND: Enhancer of zeste homolog 2 (EZH2) was recently found to play an important role in cardiovascular disease. However, the role of EZH2 in vascular remodeling induced by mechanical stretch is poorly understood. The aim of the present work was to investigate the role of EZH2 in regulating smooth muscle cell function through mechanical stretch assays and to explore the underlying mechanisms. METHODS: WT C57BL/6 J mice underwent sham surgery or abdominal aortic constriction. The level of EZH2 expression was determined by Western blotting and immunohistochemical staining. We demonstrated the thickness of vascular remodeling by HE staining. JASPAR was used to predict transcription factors that could affect EZH2. Chromatin immunoprecipitation was used to substantiate the DNAprotein interactions. Promoter luciferase assays were performed to demonstrate the activity of the transcription factors. RESULTS: We found that in vivo, AAC significantly reduced EZH2 protein levels in the thoracic aorta. Smooth muscle-specific overexpression of EZH2 was sufficient to attenuate the AAC-induced reduction in trimethylation of Lys-27 in histone 3 and thickening of the arterial media. Administration of GSK-J4 (an inhibitor of H3K27me3 demethylase) induced the same effects. In addition, we found that mechanical stretch regulated the expression of EZH2 through the Yes-associated protein (YAP)- transcriptional factor TEA domain 1 (TEAD) pathway. TEAD1 bound directly to the promoter of EZH2, and blocking the YAP-TEAD1 interaction inhibited EZH2 downregulation due to mechanical stretch. CONCLUSION: This study reveals that mechanical stretch downregulates EZH2 through the YAP-TEAD1 pathway, thereby aggravating smooth muscle cell apoptosis and vascular remodeling.

Upregulation of Endothelial DKK1 (Dickkopf 1) Promotes the Development of Pulmonary Hypertension Through the Sp1 (Specificity Protein 1)/SHMT2 (Serine Hydroxymethyltransferase 2) Pathway.

BACKGROUND: Pulmonary hypertension (PH) is a cancer-like proliferative disease, which has no curative treatment options. The dysfunction of pulmonary artery endothelial cells plays a key role in PH. DKK1 (Dickkopf 1) is a secretory glycoprotein that exerts proproliferative effects on tumor cells. In the present study, we aimed to identify the role and underlying mechanism of DKK1 in the development of PH, which still remain unclear. METHODS AND RESULTS: We found endothelial DKK1 expression was upregulated in serum and lung tissues obtained from patients with PH, mice with hypoxia-induced PH, and human pulmonary artery endothelial cells cultured under hypoxic conditions. Endothelium-specific DKK1-knockout (DKK1ECKO) mice significantly ameliorated hypoxia+Sugen5416 and hypoxia-induced PH. More importantly, neutralizing anti-DKK1 antibody treatment significantly attenuated established hypoxia+Sugen5416 PH. Results of proteome analysis of control and DKK1-knockdown human pulmonary artery endothelial cells identified a significantly differentially expressed protein, SHMT2 (serine hydroxymethyltransferase 2), a key metabolic enzyme in one-carbon metabolism, as a novel DKK1 target. DKK1 knockdown in human pulmonary artery endothelial cells cultured under hypoxic conditions decreased the cellular NADPH/NADP+ ratio, increased reactive oxygen species levels and the extent of mitochondrial DNA damage, and inhibited mitochondrial membrane hyperpolarization. In the context of this altered redox defense and mitochondrial disorder, DKK1 induced a proproliferative and antiapoptotic phenotype in endothelial cells. Furthermore, we confirmed that DKK1 regulated SHMT2 transcription through the AKT-Sp1 (specificity protein 1) signaling axis. CONCLUSIONS: Our data provide robust evidence and molecular explanations for the associations between DKK1, redox defense, mitochondrial disorders, and PH and reveal a novel target for PH treatment.

Glycyrrhizin treatment is associated with attenuation of lipopolysaccharide-induced acute lung injury by inhibiting cyclooxygenase-2 and inducible nitric oxide synthase expression.

Glycyrrhizin (GL), a major active constituent of licorice root, has been attributed numerous pharmacologic effects, including anti-inflammatory, anti-viral, anti-tumor, and hepatoprotective activities. In this study, we investigated the anti-inflammatory effect of GL on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in mice. ALI was induced in Balb/c mice by intratracheal instillation of LPS (1 mg/kg). Before 1 h of LPS administration, the mice received intraperitoneal injection of GL at varied doses (10, 25, and 50 mg/kg). The severity of pulmonary injury was evaluated 12 h after LPS administration. GL pretreatment led to significant attenuation of LPS induced evident lung histopathologic changes, alveolar hemorrhage, and neutrophil infiltration with evidence of reduced myeloperoxidase (MPO) activity. The lung wet/dry weight ratios, as an index of lung edema, were markedly reduced by GL pretreatment. The concentrations of pro-inflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor (TNF)-α were elevated in bronchoalveolar lavage fluid (BALF) after LPS administration, which were significantly inhibited by GL pretreatment. GL pretreatment also reduced the concentrations of nitric oxide (NO) in lung tissues. Furthermore, the expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) was suppressed by GL pretreatment. In conclusion, GL potently protected against LPS-induced ALI, and the protective effects of GL may attribute partly to the suppression of COX-2 and iNOS expression.

Integrating LINCS Data to Evaluate Cancer Transcriptome Modifying Potential of Small-molecule Compounds for Drug Repositioning.

BACKGROUND: Conventional high-throughput chemical screens in conjunction with genome-wide gene expression profiling proves to be successful in novel anti-cancer agent discovery and provides comprehensive insights into the mechanisms of action and off-target effects of single small-molecule compound. However, systematic evaluation on heterogeneous transcriptional responses of different cancer cell types to thousands of independent perturbations in a bioinformatics way is still limited. METHOD: Here, we introduce cancer transcriptome modifying potential (CTMP) which uses "Connectivity Score" to quantify and compare the effects of approved antineoplastic drugs on transcriptionally restoring dysregulated (both up- and down-) gene expressions at cancer state towards normal state. As a proof-of-concept, we applied this CTMP computational evaluation on > 10,000 small-molecule compounds using >200,000 Library of Integrated Network-based Cellular Signatures (LINCS) expression profiles generated upon 4 different cancer cell lines. We screened and proposed a candidate list of cancer transcriptome modifying therapeutics (CTMTs), among which the approved on-market drugs are further validated using GDSC drug sensitivity data, highlighting their potential to facilitate direct antineoplastic repositioning. RESULTS: In total, we calculated CTMPs of 85 on-market antineoplastic drugs and ~15,000 smallmolecule compounds using 253,813 transcriptomes across four cancer cell lines of lung, melanoma, prostate, and colon. Our results reveal that regardless of the chemical structure and targeted proteins majority of approved antineoplastic drugs present significant bilateral CTMPs across all 4 cancer cell lines. Bilateral CTMP-based systematic screen further indicates that candidate CTMTs are limited and most notably cancer-type specific. In particular, for each cancer cell type we proposed 3~5 CTMTs that are approved drugs with potent sensitivity data to support development in antineoplastic indications. CONCLUSION: Our work establishes CTMP to evaluate the antineoplastic property of small-molecule compounds and suggests CTMP-based systematic screen of cancer type-specific CTMTs as a feasible strategy in drug repositioning for precise anti-cancer purposes.

Lumbar Disk Degeneration in Female Patients with and without Ovariectomy: A Case-Control Study.

OBJECTIVE: We sought to provide clinical evidence of the potential influence of ovariectomy (OVX) on intervertebral disk degeneration. METHODS: We retrospectively reviewed patients with a history of OVX who visited our hospital for lower back pain. In addition, 60 age-matched patients without OVX were randomly selected as control subjects. Next, the following demographic data were recorded and compared among groups: age, body mass index, duration of OVX, history of smoking, alcohol use, hypertension, diabetes, cardiocerebrovascular disease, hyperlipemia, osteoporosis, and degenerative spondylolisthesis. Next, the severity of lumbar disk degeneration, evaluated by the modified Pfirrmann grading system, was compared between groups. Data analyses were performed with SPSS 20.0. software. RESULTS: A total of 15 OVX (unilateral, n = 10; bilateral, n = 5) patients were included with a mean age of 62.40 ± 10.64. The average durations of OVX were 21.33 ± 9.24 years. There existed no remarkable intergroup differences in the demographic data (P > 0.05). Overall, the average Pfirrmann grading scores from L1/2 to L5/S1 presented as L1/2 < L2/3 < L3/4 ≤ L5/S1 ≤ L4/5, with no marked differences between groups (P > 0.05). Nevertheless, OVX groups displayed a relatively higher score at each level than non-OVX group. Moreover, the scores from L3/4 to L5/S1 were higher in the bilateral OVX group relative to the unilateral OVX group while they were equal at L1/2 and L2/3. CONCLUSIONS: Our findings demonstrated that OVX contributed to the progression of lumbar disk degeneration to some extent, but it appeared to be a long-term event.