Single-Cell Transcriptome Analysis Identified Core Genes and Transcription Factors in Mesenchymal Cell Differentiation during Liver Cirrhosis.

BACKGROUND: Mesenchymal cells, including hepatic stellate cells (HSCs), fibroblasts (FBs), myofibroblasts (MFBs), and vascular smooth muscle cells (VSMCs), are the main cells that affect liver fibrosis and play crucial roles in maintaining tissue homeostasis. The dynamic evolution of mesenchymal cells is very important but remains to be explored for researching the reversible mechanism of hepatic fibrosis and its evolution mechanism of hepatic fibrosis to cirrhosis. METHODS: Here, we analysed the transcriptomes of more than 50,000 human single cells from three cirrhotic and three healthy liver tissue samples and the mouse hepatic mesenchymal cells of two healthy and two fibrotic livers to reconstruct the evolutionary trajectory of hepatic mesenchymal cells from a healthy to a cirrhotic state, and a subsequent integrative analysis of bulk RNA sequencing (RNA-seq) data of HSCs from quiescent to active (using transforming growth factor ß1 (TGF-ß1) to stimulate LX-2) to inactive states. RESULTS: We identified core genes and transcription factors (TFs) involved in mesenchymal cell differentiation. In healthy human and mouse livers, the expression of NR1H4 and members of the ZEB families (ZEB1 and ZEB2) changed significantly with the differentiation of FB into HSC and VSMC. In cirrhotic human livers, VSMCs transformed into HSCs with downregulation of MYH11, ACTA2, and JUNB and upregulation of PDGFRB, RGS5, IGFBP5, CD36, A2M, SOX5, and MEF2C. Following HSCs differentiation into MFBs with the upregulation of COL1A1, TIMP1, and NR1H4, a small number of MFBs reverted to inactivated HSCs (iHSCs). The differentiation trajectory of mouse hepatic mesenchymal cells was similar to that in humans; however, the evolution trajectory and proportion of cell subpopulations that reverted from MFBs to iHSCs suggest that the mouse model may not accurately reflect disease progression and outcome in humans. CONCLUSIONS: Our analysis elucidates primary genes and TFs involved in mesenchymal cell differentiation during liver fibrosis using scRNA-seq data, and demonstrated the core genes and TFs in process of HSC activation to MFB and MFB reversal to iHSC using bulk RNA-seq data of human fibrosis induced by TGF-ß1. Furthermore, our findings suggest promising targets for the treatment of liver fibrosis and provide valuable insights into the molecular mechanisms underlying its onset and progression.

Characterization of the microplastic photoaging under the action of typical salt ions of biological nitrogen removal processes.

Microplastics (MPs) are one of the most prevalent and diverse contaminants, and wastewater treatment plants are significant MP aggregators. Controlling the pollution caused by microplastics requires an understanding of how they age. The properties of the MPs photoaging process under the influence of salt ions typical of biological nitrogen elimination processes were disclosed in this work. The aging process of polyvinyl chloride microplastics (PVC-MPs) was greatly slowed down by greater HCO3- and NO2- concentrations, according to a comparison of the carbonyl index changes that occurred during photoaging. The carbonyl index had a negative correlation with the thermal stability of the photo-aged PVC-MPs, and aging accelerated the elimination of chlorine from the water. The samples were aged by UV radiation after 36 h at 40 °C, and the amount of chlorine eliminated was 10.13 times greater than that of the original MPs samples. It was discovered that the leachate concentration of aged MPs dramatically increased with decreasing particle size and was positively connected with the level of aging by comparing the concentration of leachate for two particle sizes (1 mm and 100 m). Photoaging caused MPs to become rougher, which in turn improved the NO3--N, NH4+-N, and NO2--N adsorption by PVC-MPs.

Development and preliminary validation of a self-rating anxiety inventory for maintenance haemodialysis patients.

This study aimed to develop a self-rating anxiety inventory for maintenance haemodialysis patients (AI-MHD) and perform preliminary validation to provide a simple, effective, and highly specific practical tool for effective anxiety disorder screening in haemodialysis patients. Based on existing general anxiety disorder screening scales and common symptoms of MHD patients as a reference and after expert discussions and preliminary validation at a single dialysis centre, a self-rating AI-MHD containing 12 items was developed. Subsequently, the AI-MHD was applied in 4 dialysis centres and compared with GAD-7 and HADS-A. Further multicentre validation showed that Cronbach's alpha for the scale was 0.918; the AI-MHD score not only significantly differed between the anxiety disorders group and the non-anxiety disorders group (p<0.001) but also correlated with GAD-7 and HADS-A scores (p<0.001). In addition, the Kaiser-Meyer-Olkin (KMO) score was 0.847, and Bartlett's test of sphericity was significant (x2=849.45, p<0.001). The anxiety disorder detection rate was 93%, and the specificity was 90%, which were significantly better than the screening results using the GAD-7 and HADS-A scales in the same groups. Although there were limitations, such as the sample size and regionality, the AI-MHD showed good efficacy and reliability in rating anxiety in MHD patients.

Compassion fatigue among haemodialysis nurses in public and private hospitals in China.

AIM: This study was conducted to identify and compare the levels of compassion fatigue and job satisfaction among haemodialysis nurses in public and private hospitals in China and explore explanatory factors based on sociodemographic and occupational characteristics. METHODS: A descriptive study was conducted using a self-designed demographic questionnaire, the Professional Quality of Life Scale and the Minnesota Satisfaction Questionnaire, with responses from 283 haemodialysis nurses working at six public and private hospitals in China between June and November 2018. RESULTS: The compassion fatigue score of public hospital nurses was significantly higher than that of private hospital nurses. Univariate analysis showed that there were significant differences in compassion fatigue among nurses based on the number of years worked, nature of employment, and education level. Correlational analysis showed a negative correlation between overall job satisfaction and compassion fatigue in both public and private hospitals. Multiple regression analysis showed that compassion fatigue among haemodialysis nurses in public hospitals was associated with years worked, type of employment, and intrinsic and extrinsic satisfaction, whereas in private hospitals, education level, years worked, and intrinsic and extrinsic satisfaction were significant. CONCLUSION: Haemodialysis nurses in public hospitals are more likely to develop compassion fatigue than those in private hospitals.

Transforming biorefinery designs with 'Plug-In Processes of Lignin' to enable economic waste valorization.

Biological lignin valorization has emerged as a major solution for sustainable and cost-effective biorefineries. However, current biorefineries yield lignin with inadequate fractionation for bioconversion, yet substantial changes of these biorefinery designs to focus on lignin could jeopardize carbohydrate efficiency and increase capital costs. We resolve the dilemma by designing 'plug-in processes of lignin' with the integration of leading pretreatment technologies. Substantial improvement of lignin bioconversion and synergistic enhancement of carbohydrate processing are achieved by solubilizing lignin via lowering molecular weight and increasing hydrophilic groups, addressing the dilemma of lignin- or carbohydrate-first scenarios. The plug-in processes of lignin could enable minimum polyhydroxyalkanoate selling price at as low as $6.18/kg. The results highlight the potential to achieve commercial production of polyhydroxyalkanoates as a co-product of cellulosic ethanol. Here, we show that the plug-in processes of lignin could transform biorefinery design toward sustainability by promoting carbon efficiency and optimizing the total capital cost.

Polyurethanes Based on Unmodified and Refined Technical Lignins: Correlation between Molecular Structure and Material Properties.

The structural complexity and robust intermolecular interactions have challenged the incorporation of technical lignin into value-added polymeric materials for decades. To study the correlation between lignin molecular structure and material properties of lignin-based polyurethanes, we applied co-solvent enhanced lignocellulosic fractionation pretreatment followed by sequential precipitation to produce three distinct lignin preparations with narrowly distributed (molecular weight dispersity <2) and comparatively low molecular weight (<1500 g/mol) from poplar biomass. Structural characterization indicated that these lignin preparations differed in average molecular chain length and stiffness as well as hydroxyl group distribution. Secondary hydroxyl group providers such as aliphatic diols and polyethers were incorporated as building blocks into the lignin-based polyurethanes to provide additional hydrogen capacity to improve the dispersion of lignin in the polyurethane network. The selected aliphatic diols and polyethers interacted with lignin molecules at different levels of strength depending on their molecular structure, and their impacts were ultimately reflected in the mechanical and thermal properties of the resulting lignin-based polyurethanes. The copolymerization of technical lignin with tailored structure and secondary hydroxyl providers could provide new strategies in formulating lignin-based/containing polyurethanes for various functional applications.

Xylan and xylose decomposition during hot water pre-extraction: A pH-regulated hydrolysis.

One of the key issues in the development of biofuels using lignocellulosic feedstocks is to increase the yield of fermented sugar, and simultaneously decrease the generation of fermentation inhibitors. Therefore, it is essential to understand the degradation mechanism of xylan during hot-water pretreatment. We analyzed the hydrothermal degradation products of xylan and xylose under different conditions. Results showed that furfural and formic acid formed from xylose reached a maximum value of 32.56 % and 35.14 %, respectively. By increasing the initial pH of the xylan solution, the furfural concentration can be reduced effectively to 2% and the formation of formic acid was preferred under alkaline conditions. On this basis, we proposed a new hydrothermal degradation pathway of xylan in alkaline solution. The in-depth understanding of xlyan degradation during hot water pre-treatment will be beneficial for improving the efficiency of biofuel production.

Recent Advances in the Application of Functionalized Lignin in Value-Added Polymeric Materials.

The quest for converting lignin into high-value products has been continuously pursued in the past few decades. In its native form, lignin is a group of heterogeneous polymers comprised of phenylpropanoids. The major commercial lignin streams, including Kraft lignin, lignosulfonates, soda lignin and organosolv lignin, are produced from industrial processes including the paper and pulping industry and emerging lignocellulosic biorefineries. Although lignin has been viewed as a low-cost and renewable feedstock to replace petroleum-based materials, its utilization in polymeric materials has been suppressed due to the low reactivity and inherent physicochemical properties of lignin. Hence, various lignin modification strategies have been developed to overcome these problems. Herein, we review recent progress made in the utilization of functionalized lignins in commodity polymers including thermoset resins, blends/composites, grafted functionalized copolymers and carbon fiber precursors. In the synthesis of thermoset resins such as polyurethane, phenol-formaldehyde and epoxy, they are covalently incorporated into the polymer matrix, and the discussion is focused on chemical modifications improving the reactivity of technical lignins. In blends/composites, functionalization of technical lignins is based upon tuning the intermolecular forces between polymer components. In addition, grafted functional polymers have expanded the utilization of lignin-based copolymers to biomedical materials and value-added additives. Different modification approaches have also been applied to facilitate the application of lignin as carbon fiber precursors, heavy metal adsorbents and nanoparticles. These emerging fields will create new opportunities in cost-effectively integrating the lignin valorization into lignocellulosic biorefineries.

Synthesis, Characterization, and Utilization of a Lignin-Based Adsorbent for Effective Removal of Azo Dye from Aqueous Solution.

How to effectively remove toxic dyes from the industrial wastewater using a green low-cost lignocellulose-based adsorbent, such as lignin, has become a topic of great interest but remains quite challenging. In this study, cosolvent-enhanced lignocellulosic fractionation (CELF) pretreatment and Mannich reaction were combined to generate an aminated CELF lignin which is subsequently applied for removal of methylene blue and direct blue (DB) 1 dye from aqueous solution. 31P NMR was used to track the degree of amination, and an orthogonal design was applied to determine the relationship between the extent of amination and reaction parameters. The physicochemical, morphological, and thermal properties of the aminated CELF lignin were characterized to confirm the successful grafting of diethylenetriamine onto the lignin. The aminated CELF lignin proved to be an effective azo dye-adsorbent, demonstrating considerably enhanced dye decolorization, especially toward DB 1 dye (>90%). It had a maximum adsorption capacity of DB 1 dye of 502.7 mg/g, and the kinetic study suggested the adsorption process conformed to a pseudo-second-order kinetic model. The isotherm results also showed that the modified lignin-based adsorbent exhibited monolayer adsorption. The adsorbent properties were mainly attributed to the incorporated amine functionalities as well as the increased specific surface area of the aminated CELF lignin.

Lignin-Only Polymeric Materials Based on Unmethylated Unfractionated Kraft and Ball-Milled Lignins Surpass Polyethylene and Polystyrene in Tensile Strength.

Functional polymeric materials composed solely of lignin preparations appeared only very recently. A gradual paradigm shift spanning 56 years has revealed how lignin-lignin blends can upgrade the performance of 100 wt% lignin-based plastics. The view, first espoused in 1960, that lignin macromolecules are crosslinked reduces the plausibility of creating functional polymeric materials that are composed only of lignin preparations. Lignin-based materials would be much weaker mechanically if interstices remain in significant numbers between adjoining macromolecular structures that consist of rigid crosslinked chains. In 1982, random-coil features in the hydrodynamic character of kraft lignin (KL) components were evident from ultracentrifugal sedimentation equilibrium studies of their SEC behavior. In 1997, it was recognized that the macromolecular species in plastics with 85 wt% levels of KL are associated complexes rather than individual components. Finally, in 2016, the first polymeric material composed entirely of ball-milled softwood lignin (BML) was found to support a tensile strength above polyethylene. Except in its molecular weight, the BML was similar in structure to the native biopolymer. It was composed of associated lignin complexes, each with aromatic rings arranged in two domains. The inner domain maintains structural integrity largely through noncovalent interactions between cofacially-offset aromatic rings; the peripheral domain contains a higher proportion of edge-on aromatic-ring arrangements. Interdigitation between peripheral domains in adjoining complexes creates material continuity during casting. By interacting at low concentrations with the peripheral domains, non-lignin blend components can improve the tensile strengths of BML-based plastics to values well beyond those seen in polystyrene. The KL-based plastics are weaker because the peripheral domains of adjoining complexes are less capable of interdigitation than those of BML. Blending with 5 wt% 1,8-dinitroanthraquinone results in a tensile strength above that of polyethylene. Analogous effects can be achieved with 10 wt% maple γ-valerolactone (GVL) lignin which, with a structure close to the native biopolymer, imparts some native character to the peripheral domains of the KL complexes. Comparable enhancements in the behavior of BML complexes upon blending with 10 wt% ball-milled corn-stover lignin (BMCSL) result in lignin-only polymeric materials with tensile strengths well beyond polystyrene.

Structural characterization of lignin in heartwood, sapwood, and bark of eucalyptus.

Understanding the distribution and structural features of lignin in heartwood, sapwood, and bark of terrestrial plants is important to optimize the industrial utilization of lignocellulose. In this work, the lignins in heartwood, sapwood, and bark of Eucalyptus urophylla × E. grandis were comparatively studied. Confocal Raman microscopy was used to probe the heterogeneity of lignin distribution in situ. The swollen residual enzyme lignin samples were isolated and systematically characterized to determine the structural differences. The results showed that the content and molecular weights of lignin gradually decreased in the order of heartwood, sapwood, and bark. The S/G ratios of heartwood lignin (3.45) and sapwood lignin (2.74) suggested the increase of deposited S-type lignin with the maturity of wood. The bark lignin exhibited a high frequency of ß-O-4' linkages and showed a unique substructural pattern with the absence of spirodienone substructures and p-hydroxycinnamyl alcohol end-groups.

Conditioned taste aversion memory extinction temporally induces insular cortical BDNF release and inhibits neuronal apoptosis.

BACKGROUND: Memory extinction has been reported to be related to psychiatric disorders, such as post-traumatic stress disorder (PTSD). Secretion and synthesis of brain-derived neurotrophic factor (BDNF) have been shown to temporally regulate various memory processes via activation of tropomyosin-related kinase B (TrkB) receptors. However, whether memory extinction induces the synthesis and secretion of BDNF on the basis of its localization is not understood. In this study, we aim to investigate activity-dependent BDNF secretion and synthesis in the insular cortex (IC) in the setting of conditioned taste aversion (CTA) memory extinction. MATERIALS AND METHODS: Rats were subjected to CTA memory extinction and BDNF antibody (or the equal volume of vehicle) was microinjected into the IC immediately after the extinction testing. Real-time polymerase chain reaction and in situ hybridization were used to detect the gene expression of BDNF, NGF and NT4. The protein levels of BDNF were determined through the enzyme-linked immunosorbent assay. In addition, the levels of phosphorylated TrkB normalized to total TrkB were evaluated using immunoprecipitation and immunoblotting. c-Fos, total extracellular signal-regulated kinase (Erk), phosphorylated Erk, and apoptosis-related protein (caspase-3), were detected by Western blotting. RESULTS: We found that blocking BDNF signaling within the IC disrupts CTA extinction, suggesting that BDNF signaling in the IC is necessary for CTA extinction. Increased expression levels of c-Fos indicate the induced neuronal activity in the IC during CTA extinction. In addition, temporal changes in the gene expression and protein levels of BDNF in the IC were noted during extinction. Moreover, we found that phosphorylation of TrkB increased prior to the enhanced BDNF expression, suggesting that CTA extinction induces rapid activity-dependent BDNF secretion in the IC. Finally, we found decreased expression of caspase-3 in the IC after CTA extinction. CONCLUSION: These results demonstrate that CTA memory extinction temporally induces the release and synthesis of BDNF in the IC and inhibits neuronal apoptosis.

Development and Preliminary Validation of a Depression Assessment Tool for Maintenance Hemodialysis Patients.

Patients undergoing maintenance hemodialysis (MHD) are subject to a higher-than-usual prevalence of depressive disorders. However, the lack of consensus regarding the best assessment method remains an important problem. Thus, there is a clear need for more effective screening tools and an easily administered, disease-specific self-report measure of depression in MHD patients. After we developed and administered an initial depression inventory for MHD patients (I-DI-MHD), we created the DI-MHD and administered the DI-MHD and the Beck Depression Inventory (BDI) to 354 patients from four hospitals. Reliability, construct validity and receiver operator characteristic curves were assessed. The 17-item DI-MHD instrument displayed good internal consistency (Cronbach's alpha =0.893), provided excellent convergent validity, and correlated with the BDI scale (kappa =0.785, P <0.001). A factor analysis pattern matrix analysis showed that a four-factor model provided the best account of the data. Finally, the DI-MHD cutoff yielded a sensitivity of 0.97 and a specificity of 0.86, which were slightly better than the corresponding values for the BDI. The DI-MHD scale shows reasonable validity and reliability for assessing depression in MHD patients.

Phosphoglycerate mutase 1 is highly expressed in C6 glioma cells and human astrocytoma.

The aim of the present study was to examine the expression of phosphoglycerate mutase 1 (PGAM1) in astrocytomas, and to investigate its role in the progression of astrocytomas. The expression of PGAM1 mRNA in rat C6 glioma cells and normal astrocytes was determined using the reverse transcription-semi-quantitative polymerase chain reaction, and immunohistochemistry was used to detect the expression of PGAM1 protein in human astrocytomas and adjacent brain tissue. These data suggested that the expression of PGAM1 in rat C6 glioma cells was significantly increased compared with that of normal astrocytes (P<0.05), and the expression of PGAM1 protein in human astrocytoma tissue was significantly increased compared with that of the brain tissue surrounding the tumor (P<0.05). In addition, PGAM1 protein was more frequently expressed in high-grade astrocytomas compared with low-grade astrocytomas. These data indicate that the expression of PGAM1 is increased in C6 cells and human astrocytomas, and PGAM1 is probably involved in the tumorigenesis and progression of glioma, which may be a potential target for glioma treatment.

Corrigendum to "Start-Up Characteristics of a Granule-Based Anammox UASB Reactor Seeded with Anaerobic Granular Sludge".

[This corrects the article DOI: 10.1155/2013/396487.].

Blend configuration in functional polymeric materials with a high lignin content.

Lignins upgrade the lignocellulosic cell-wall domains in all vascular plants; they embody 20-30% of terrestrial organic carbon. For 50 years, mistaken assumptions about the configuration of lignin have hindered the development of useful polymeric materials with a lignin content above 40 wt%. Now, polymeric materials composed only of methylated softwood lignin derivatives can exhibit better tensile behavior than polystyrene. Marked improvements may be achieved with small quantities (5-10 wt%) of miscible blend components as simple as poly(ethylene glycol). These observations contradict commonly held views about crosslinking or hyper-branching in lignin chains. The hydrodynamic compactness of the macromolecular lignin species arises from powerful noncovalent interactions between the lignin substructures. Individual lignin components undergo association to form macromolecular complexes that are preserved in plastics with a very high lignin content. Material continuity results from interpenetration between the peripheral components in adjoining lignin complexes. Through interactions with the peripheral domains, miscible blend components modulate the strength and ductility of these utterly original lignin-based plastics.

Effect of alkaline preswelling on the structure of lignins from Eucalyptus.

A clear elucidation of structural feature of whole lignin in plant cell wall is of great importance for understanding lignin biosynthesis mechanism and developing lignin based chemicals or materials under the current biorefinery scenario. Swollen residual enzyme lignin (SREL) has been identified as an ideal representative for native lignin in the plant walls. To investigate the influence of preswelling conditions on the structural features, the SREL obtained through preswelling the ball-milled Eucalyptus wood powder in 2, 4 and 8% NaOH solutions and subsequent in-situ enzymatic hydrolysis were thoroughly characterized. A cellulolytic enzyme lignin (CEL) was also prepared as a comparison. The quantitative NMR analyses indicated that the relative contents of ß-O-4' linkages in SRELs were higher than that in CEL. The lignin structure tended to undergo more destruction with the elevated NaOH concentration. A relatively low NaOH concentration (2% in this study), which could be applied to effectively remove hemicelluloses and transform cellulose structure from cellulose I to cellulose II, was competent to prepare SREL as an ideal representative for the protolignin. An optimization of SREL preparation was essential for a better understanding of the whole protolignin.

Valorization of lignin and cellulose in acid-steam-exploded corn stover by a moderate alkaline ethanol post-treatment based on an integrated biorefinery concept.

BACKGROUND: Due to the unsustainable consumption of fossil resources, great efforts have been made to convert lignocellulose into bioethanol and commodity organic compounds through biological methods. The conversion of cellulose is impeded by the compactness of plant cell wall matrix and crystalline structure of the native cellulose. Therefore, appropriate pretreatment and even post-treatment are indispensable to overcome this problem. Additionally, an adequate utilization of coproduct lignin will be important for improving the economic viability of modern biorefinery industries. RESULTS: The effectiveness of moderate alkaline ethanol post-treatment on the bioconversion efficiency of cellulose in the acid-steam-exploded corn stover was investigated in this study. Results showed that an increase of the alcoholic sodium hydroxide (NaOH) concentration from 0.05 to 4% led to a decrease in the lignin content in the post-treated samples from 32.8 to 10.7%, while the cellulose digestibility consequently increased. The cellulose conversion of the 4% alcoholic NaOH integrally treated corn stover reached up to 99.3% after 72 h, which was significantly higher than that of the acid steam exploded corn stover without post-treatment (57.3%). In addition to the decrease in lignin content, an expansion of cellulose I lattice induced by the 4% alcoholic NaOH post-treatment played a significant role in promoting the enzymatic hydrolysis of corn stover. More importantly, the lignin fraction (AL) released during the 4% alcoholic NaOH post-treatment and the lignin-rich residue (EHR) remained after the enzymatic hydrolysis of the 4% alcoholic NaOH post-treated acid-steam-exploded corn stover were employed to synthesize lignin-phenol-formaldehyde (LPF) resins. The plywoods prepared with the resins exhibit satisfactory performances. CONCLUSIONS: An alkaline ethanol system with an appropriate NaOH concentration could improve the removal of lignin and modification of the crystalline structure of cellulose in acid-steam-exploded corn stover, and consequently significantly improve the conversion of cellulose through enzymatic hydrolysis for biofuel production. The lignin fractions obtained as byproducts could be applied in high performance LPF resin preparation. The proposed model for the integral valorization of corn stover in this study is worth of popularization.

LINC00312 inhibits the migration and invasion of bladder cancer cells by targeting miR-197-3p.

To investigate the influence of the long non-coding RNA LINC00312 on bladder cancer (BC) cell invasion and metastasis by targeting miR-197-3p. BC and corresponding adjacent tissues were collected. LINC00312 and miR-197-3p were measured, and their correlation was detected through quantitative real-time PCR (qRT-PCR). BC cell line T24 was transfected and grouped (five groups) according to different transfection conditions. A scratch test was applied to analyze cell migration, and a Transwell assay was used to test cell invasion ability. Western blotting was to measure matrix metalloproteinase (MMP)-2, MMP-9, and the tissue inhibitor of metalloproteinase 2 (TIMP2) protein levels. qRT-PCR indicated that LINC00312 expression was lower but miR-197-3p expression was higher in BC tissues compared with adjacent tissues; LINC00312 was negatively correlated with miR-197-3p. The migration test revealed that the downregulation of miR-197-3p and overexpression of LINC00312 inhibited cell migration and invasion abilities, while the overexpression of miR-197-3p and the upregulation of LINC00312 promoted cell migration and invasion. BC cells with downregulated miR-197-3p or upregulated LINC00312 had low MMP-2 and MMP-9 levels but high TIMP2. LINC00312 inhibited BC cell invasion and metastasis through mediating miR-197-3p.

Secreted Protein Acidic and Rich in Cysteine Modulates Molecular Arterial Homeostasis of Human Arterial Smooth Muscle Cells In Vitro.

Secreted protein acidic and rich in cysteine (SPARC) is widely expressed in the vascular smooth muscle cells (VSMCs) of human intracranial aneurysms (IAs), but the effect and underlying mechanism of SPARC on VSMCs during the formation and progression of IAs needs to be probed. Human umbilical arterial smooth muscle cells (HUASMCs) were treated with a gradient concentrations of SPARC in vitro for different time. Cell counting kit-8 (CCK-8) assay, cell cycle, and cell apoptosis were used to investigate the effect of SPARC on HUASMCs. After exposure to 2 and 4 µg/ml SPARC, cell viability were 89.3 ± 2.00 %, and 87.57 ± 2.17 % (P < 0.05 vs. control), respectively. Induced by 2 µg/ml SPARC, the proportion of cells in G0/G1 phase was 74.77 ± 1.33 % (P < 0.05 vs. control), and the early and late apoptosis ratio were 7.38 ± 1.25 % and 4.86 ± 0.81 % (P < 0.01 vs. control), respectively. After exposure to 2 µg/ml SPARC for 2, 6, 12, 24, and 48 h, Western blot analysis showed that the protein level of p21 was upregulated significantly at 2-12 h (P < 0.05 vs. control), while the expression of p53 remained stable within 48 h. The expression of Bax protein increased markedly and peaked at 24 (P < 0.01 vs. control), while Bcl2 protein decreased significantly at 48 h (P < 0.01 vs. control). Cleaved caspase3 was also upregulated dramatically and peaked at 24 h (P < 0.05 vs. control). The protein level of MMP2 increased significantly and peaked at 24 h (P < 0.01 vs. control), while TIMP2 remained stable and even reduced at 48 h (P < 0.05 vs. control). Taken together, SPARC could arrest HUASMCs in G0/G1 phase by overexpression of p21 and induce mitochondria-mediated apoptosis in vitro, which could result in the decreased cell viability. Besides, SPARC might also lead to the activation of MMP2 instead of MMP9. These results indicated SPARC could reduce the self-repair capability and increase injury of media layer and internal elastic lamina of intracranial artery, which would disrupt the normal homeostatic mechanism controlling vascular repair, thus promoting the formation and progression of IAs.