Sphingosylphosphorylcholine alleviates pressure overload-induced myocardial remodeling in mice via inhibiting CaM-JNK/p38 signaling pathway.

Apoptosis plays a critical role in the development of heart failure, and sphingosylphosphorylcholine (SPC) is a bioactive sphingolipid naturally occurring in blood plasma. Some studies have shown that SPC inhibits hypoxia-induced apoptosis in myofibroblasts, the crucial non-muscle cells in the heart. Calmodulin (CaM) is a known SPC receptor. In this study we investigated the role of CaM in cardiomyocyte apoptosis in heart failure and the associated signaling pathways. Pressure overload was induced in mice by trans-aortic constriction (TAC) surgery. TAC mice were administered SPC (10 µM·kg-1·d-1) for 4 weeks post-surgery. We showed that SPC administration significantly improved survival rate and cardiac hypertrophy, and inhibited cardiac fibrosis in TAC mice. In neonatal mouse cardiomyocytes, treatment with SPC (10 µM) significantly inhibited Ang II-induced cardiomyocyte hypertrophy, fibroblast-to-myofibroblast transition and cell apoptosis accompanied by reduced Bax and phosphorylation levels of CaM, JNK and p38, as well as upregulated Bcl-2, a cardiomyocyte-protective protein. Thapsigargin (TG) could enhance CaM functions by increasing Ca2+ levels in cytoplasm. TG (3 µM) annulled the protective effect of SPC against Ang II-induced cardiomyocyte apoptosis. Furthermore, we demonstrated that SPC-mediated inhibition of cardiomyocyte apoptosis involved the regulation of p38 and JNK phosphorylation, which was downstream of CaM. These results offer new evidence for SPC regulation of cardiomyocyte apoptosis, potentially providing a new therapeutic target for cardiac remodeling following stress overload.

Role of the Hippo-YAP/NF-κB signaling pathway crosstalk in regulating biological behaviors of macrophages under titanium ion exposure.

The presence of metal ions, such as titanium (Ti) ions, is toxic to adjacent tissues of implants. Indeed, Ti ions may induce an inflammatory response through the NF-κB pathway, thus causing damage to soft and hard tissues. The involvement of Yes-associated protein (YAP), a key factor of the Hippo pathway, in an immuno-inflammatory response has been confirmed, whereas its role in Ti ion-mediated inflammation has not been elucidated. Therefore, this study aimed to investigate the role of signal crosstalk between the Hippo/YAP and NF-κB signaling pathways in the pro-inflammatory effect of Ti ions on macrophages. In our work, RAW264.7 cells were cocultured with Ti ions. The migration capacity of macrophages under Ti ion exposure was measured by transwell assay. Western blot analysis was used to detect the expressions of related proteins. Polymerase chain reaction was used to evaluate the expression of pro-inflammatory cytokines. The nucleus translocation of YAP and P65 was visualized and analyzed via immunofluorescence staining. The results showed that the migration of macrophages was promoted under Ti ion exposure. Ten parts per million Ti ions induced nuclear expression of YAP and activated the NF-κB pathway, which finally upregulated the expression of pro-inflammatory cytokines in macrophages. Moreover, the inhibition of the NF-κB pathway rescued the reduction of YAP expression under Ti ion exposure. Most importantly, the overexpression of YAP exacerbated the inflammatory response mediated by Ti ions through the NF-κB pathway. In summary, this study explored the mechanism of Hippo-YAP/NF-κB pathway crosstalk involved in the regulation of macrophage behaviors under Ti ion exposure.

Enhanced corrosion resistance of zinc-containing nanowires-modified titanium surface under exposure to oxidizing microenvironment.

Titanium (Ti) and its alloys as bio-implants have excellent biocompatibilities and osteogenic properties after modification of chemical composition and topography via various methods. The corrosion resistance of these modified materials is of great importance for changing oral system, while few researches have reported this point. Recently, oxidative corrosion induced by cellular metabolites has been well concerned. In this study, we explored the corrosion behaviors of four common materials (commercially pure Ti, cp-Ti; Sandblasting and acid etching-modified Ti, Ti-SLA; nanowires-modified Ti, Ti-NW; and zinc-containing nanowires-modified Ti, Ti-NW-Zn) with excellent biocompatibilities and osteogenic capacities under the macrophages induced-oxidizing microenvironment. The results showed that the materials immersed into a high oxidizing environment were more vulnerable to corrode. Meanwhile, different surfaces also showed various corrosion susceptibilities under oxidizing condition. Samples embed with zinc element exhibited more excellent corrosion resistance compared with other three surfaces exposure to excessive H2O2. Besides, we found that zinc-decorated Ti surfaces inhibited the adhesion and proliferation of macrophages on its surface and induced the M2 states of macrophages to better healing and tissue reconstruction. Most importantly, zinc-decorated Ti surfaces markedly increased the expressions of antioxidant enzyme relative genes in macrophages. It improved the oxidation microenvironment around the materials and further protected their properties. In summary, our results demonstrated that Ti-NW-Zn surfaces not only provided excellent corrosion resistance properties, but also inhibited the adhesion of macrophages. These aspects were necessary for maintaining osseointegration capacity and enhancing the corrosion resistance of Ti in numerous medical applications, particularly in dentistry.

Association between donor and recipient Interleukin-18 gene polymorphisms and the risk of infection after liver transplantation.

PURPOSE: The purpose of this study was to retrospectively evaluate the association between Interleukin-18 (IL-18) gene polymorphisms of the donor and recipient in liver transplant patients with bacterial infections. METHODS: Five single nucleotide polymorphisms (SNPs) (rs7106524, rs5744247, rs1946518, rs549908 and rs187238) of the IL-18 gene from the donors were genotyped and their association with post-operative bacterial infections was evaluated in liver transplant patients (N=113). A second independent group of liver transplant patients from a different organ transplant centre was also recruited for validation purposes (N=44). RESULTS: IL-18 mRNA mean expression levels and protein levels were significantly lower in liver transplant patients with bacterial infections. For the donor SNP rs1946518, more recipients carried the A allele in the bacterial-infected group than the uninfected group (61.4% vs 39.7%; P ≤0.002). The mean IL-18 mRNA expression and protein levels were significantly lower in the transplanted livers of recipients carrying the rs1946518 AA genotype compared with those from recipients with CC genotype (3.64, 3.33 vs. 2.75, P≤0.048). The A allele of rs1946518 also resulted in lower luciferase activity than the C allele in a reporter assay. The area under ROC curve indicated that the rs1946518 SNP genotype in the donor liver predicted an increased risk of bacterial infection after liver transplantation (AUROC>0.82). CONCLUSIONS: These findings indicate that the IL-18 rs1946518 SNP in the donor liver is a risk factor for developing bacterial infection after liver transplantation.

Self-surface assembly of cellulosomes with two miniscaffoldins on Saccharomyces cerevisiae for cellulosic ethanol production.

Yeast to directly convert cellulose and, especially, the microcrystalline cellulose into bioethanol, was engineered through display of minicellulosomes on the cell surface of Saccharomyces cerevisiae. The construction and cell surface attachment of cellulosomes were accomplished with two individual miniscaffoldins to increase the display level. All of the cellulases including a celCCA (endoglucanase), a celCCE (cellobiohydrolase), and a Ccel_2454 (ß-glucosidase) were cloned from Clostridium cellulolyticum, ensuring the thermal compatibility between cellulose hydrolysis and yeast fermentation. Cellulases and one of miniscaffoldins were secreted by α-factor; thus, the assembly and attachment to anchoring miniscaffoldin were accomplished extracellularly. Immunofluorescence microscopy, flow cytometric analysis (FACS), and cellulosic ethanol fermentation confirmed the successful display of such complex on the yeast surface. Enzyme-enzyme synergy, enzyme-proximity synergy, and cellulose-enzyme-cell synergy were analyzed, and the length of anchoring miniscaffoldin was optimized. The engineered S. cerevisiae was applied in fermentation of carboxymethyl cellulose (CMC), phosphoric acid-swollen cellulose (PASC), or Avicel. It showed a significant hydrolytic activity toward microcrystalline cellulose, with an ethanol titer of 1,412 mg/L. This indicates that simultaneous saccharification and fermentation of crystalline cellulose to ethanol can be accomplished by the yeast, engineered with minicellulosome.

Polyphenols as Potential Antioxidants for the Treatment of Intervertebral Disc Degeneration.

Intervertebral disc degeneration (IDD) is a common musculoskeletal system disease, which is one of the most important causes of low back pain. Despite the high prevalence of IDD, current treatments are limited to relieving symptoms, and there are no effective therapeutic agents that can block or reverse the progression of IDD. Oxidative stress, the result of an imbalance between the production of reactive oxygen species (ROS) and clearance by the antioxidant defense system, plays an important role in the progression of IDD. Polyphenols are antioxidant compounds that can inhibit ROS production, which can scavenge free radicals, reduce hydrogen peroxide production, and inhibit lipid oxidation in nucleus pulposus (NP) cells and IDD animal models. In this review, we discussed the antioxidant effects of polyphenols and their regulatory role in different molecular pathways associated with the pathogenesis of IDD, as well as the limitations and future prospects of polyphenols as a potential treatment of IDD.

Cardiac-Specific Overexpression of Caveolin-1 in Rats With Ischemic Cardiomyopathy Improves Arrhythmogenicity and Cardiac Remodelling.

BACKGROUND: Ischemic cardiomyopathy (ICM) is associated with electrical and structural remodelling, leading to arrhythmias. Caveolin-1 (Cav1) is a membrane protein involved in the pathogenesis of ischemic injury. Cav1 deficiency has been associated with arrhythmogenicity. The current study aimed to determine how Cav1 overexpression inhibits arrhythmias and cardiac remodelling in ICM. METHODS: ICM was modelled using left anterior descending (LAD) artery ligation for 4 weeks. Cardiac-specific Cav1 overexpression in ICM on arrhythmias, excitation-contraction coupling, and cardiac remodelling were investigated using the intramyocardial injection of an adeno-associated virus serotype 9 (AAV-9) system, carrying a specific sequence expressing Cav1 (AAVCav1) under the cardiac troponin T (cTnT) promoter. RESULTS: Cav1 overexpression decreased susceptibility to arrhythmias by upregulating gap junction connexin 43 (CX43) and reducing spontaneous irregular proarrhythmogenic Ca2+ waves in ventricular cardiomyocytes. It also alleviated ischemic injury-induced contractility weakness by improving Ca2+ cycling through normalizing Ca2+-handling protein levels and improving Ca2+ homeostasis. Masson stain and immunoblotting revealed that the deposition of excessive fibrosis was attenuated by Cav1 overexpression, inhibiting the transforming growth factor-ß (TGF-ß)/Smad2 signalling pathway. Coimmunoprecipitation assays demonstrated that the interaction between Cav1 and cSrc modulated CX43 expression and Ca2+-handling protein levels. CONCLUSIONS: Cardiac-specific overexpression of Cav1 attenuated ventricular arrhythmia, improved Ca2+ cycling, and attenuated cardiac remodelling. These effects were attributed to modulation of CX43, normalized Ca2+-handling protein levels, improved Ca2+ homeostasis, and attenuated cardiac fibrosis.

Loss of USP22 alleviates cardiac hypertrophy induced by pressure overload through HiF1-α-TAK1 signaling pathway.

Ubiquitin-specific protease 22 (USP22) is a member of the ubiquitin specific protease family (ubiquitin-specific protease, USPs), the largest subfamily of deubiquitinating enzymes, and plays an important role in the treatment of tumors. USP22 is also expressed in the heart. However, the role of USP22 in heart disease remains unclear. In this study, we found that USP22 was elevated in hypertrophic mouse hearts and in angiotensin II (Ang II)-induced cardiomyocytes. The inhibition of USP22 expression with adenovirus significantly rescued hypertrophic phenotype and cardiac dysfunction induced by pressure overloaded. Consistent with in vivo study, silencing by USP22 shRNA expression in vitro had similar results. Molecular analysis revealed that transforming growth factor-ß-activating protein 1 (TAK1)-(JNK1/2)/P38 signaling pathway and HIF-1α was activated in the Ang II-induced hypertrophic cardiomyocytes, whereas HIF-1α expression was decreased after the inhibition of USP22. Inhibition of HIF-1α expression reduces TAK1 expression. Co-immunoprecipitation and ubiquitination studies revealed the regulatory mechanism between USP22 and HIF1α.Under hypertrophic stress conditions, USP22 enhances the stability of HIF-1α through its deubiquitination activity, which further activates the TAK1-(JNK1/2)/P38 signaling pathway to lead to cardiac hypertrophy. Inhibition of HIF-1α expression further potentiates the in vivo pathological effects caused by USP22 deficiency. In summary, this study suggests that USP22, through HIF-1α-TAK1-(JNK1/2)/P38 signaling pathway, may be potential targets for inhibiting pathological cardiac hypertrophy induced by pressure overload.

Parkin-mediated mitophagy protects against TNF-α-induced stress in bone marrow mesenchymal stem cells.

Bone marrow mesenchymal stem cells (BMSCs) have been investigated as cellular therapeutics for intervertebral disc degeneration. However, transplanted BMSCs are prone to be damaged. TNF-α is reported to extensively promote degeneration process. Nevertheless, the relationship between BMSCs senescence and TNF-α-induced stress has not been elucidated. Previous studies showed that mitophagy is a crucial factor in maintaining cellular homeostasis. Hence, we sought to clarify the role and mechanism of mitophagy in TNF-α-induced biological changes of BMSCs. Here, we found that TNF-α caused transient senescent damage in the early stage. Meanwhile, Parkin-mediated mitophagy was initiated and weakened the damage through maintaining mitochondria homeostasis. After inhibiting mitophagy by knockdown of Parkin, TNF-α irreversibly caused cellular senescence. These results suggested that Parkin-mediated mitophagy played protective role in BMSCs in response to TNF-α, which could be a crucial therapeutic target in the future.

Long non-coding RNA HOXA-AS3 facilitates the malignancy in colorectal cancer by miR-4319/SPNS2 axis.

Growing evidence has shown the oncogenic role of long non-coding RNA HOXA-AS3 in the progression of several types of cancers, while the effect of HOXA-AS3 on colorectal cancer (CRC) remains unclear. In this study, HOXA-AS3 was significantly over-expressed in CRC clinical samples and human CRC cell lines (SW480, SW620, HCT116, COLO205, and LOVO). HOXA-AS3 knockdown was further achieved by specific siRNAs in COLO205 and LOVO cell lines. The depletion of HOXA-AS3 remarkably inhibited cell proliferation, induced cell cycle arrest, and promoted cell apoptosis in CRC cell lines. Additionally, HOXA-AS3 knockdown was determined to facilitate miR-4319 expression and reduce expression level of sphingolipid transporter 2 (SPNS2) in CRC cell lines. The dual luciferase reporter assay suggested that HOXA-AS3 acted as a sponge of miR-4319, and miR-4319 further directly targeted SPNS2 for expression regulation. Besides, HOXA-AS3 was determined to mediate CRC cell proliferation and apoptosis via miR-4319/SPNS2 axis. Moreover, tumorigenesis experiment validated that HOXA-AS3 promoted CRC progression in vivo by regulating miR-4319, SPNS2, and protein kinase B (AKT) signaling. In summary, this study reveals the novel role of HOXA-AS3 in pathogenesis of CRC and provides a candidate for CRC therapeutic target.

Multiparameter MRI Radiomics Model Predicts Preoperative Peritoneal Carcinomatosis in Ovarian Cancer.

OBJECTIVES: To evaluate the predictive value of radiomics features based on multiparameter magnetic resonance imaging (MP-MRI) for peritoneal carcinomatosis (PC) in patients with ovarian cancer (OC). METHODS: A total of 86 patients with epithelial OC were included in this retrospective study. All patients underwent FS-T2WI, DWI, and DCE-MRI scans, followed by total hysterectomy plus omentectomy. Quantitative imaging features were extracted from preoperative FS-T2WI, DWI, and DCE-MRI images, and feature screening was performed using a minimum redundancy maximum correlation (mRMR) and least absolute shrinkage selection operator (LASSO) methods. Four radiomics models were constructed based on three MRI sequences. Then, combined with radiomics characteristics and clinicopathological risk factors, a multi-factor Logistic regression method was used to construct a radiomics nomogram, and the performance of the radiomics nomogram was evaluated by receiver operating characteristic curve (ROC) curve, calibration curve, and decision curve analysis. RESULTS: The radiomics model from the MP-MRI combined sequence showed a higher area under the curve (AUC) than the model from FS-T2WI, DWI, and DCE-MRI alone (0.846 vs. 0.762, 0.830, 0.807, respectively). The radiomics nomogram (AUC=0.902) constructed by combining radiomics characteristics and clinicopathological risk factors showed a better diagnostic effect than the clinical model (AUC=0.858) and the radiomics model (AUC=0.846). The decision curve analysis shows that the radiomics nomogram has good clinical application value, and the calibration curve also proves that it has good stability. CONCLUSION: Radiomics nomogram based on MP-MRI combined sequence showed good predictive accuracy for PC in patients with OC. This tool can be used to identify peritoneal carcinomatosis in OC patients before surgery.

Osteoclast-mediated biocorrosion of pure titanium in an inflammatory microenvironment.

Titanium (Ti) and alloys thereof are commonly utilized in biomedical settings owing to their desirable mechanical properties and good biocompatibility. However, when exposed to biological systems for extended periods of time, Ti still undergoes corrosion. In the present study, we therefore explore the impact of osteoclasts (OC) on the surface characteristics and corrosion of commercially pure Titanium (cpTi) in the context of lipopolysaccharide (LPS)-induced inflammation. We utilized tartrate resistant acidic phosphatase (TRAP) and fluorescence staining to assess OC properties, while scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), optical profilometer, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization tests, and inductively coupled plasma atomic emission spectrometry (ICP-AES) were used to evaluate metal microstructure, surface composition and roughness, electrochemical corrosion properties, and metal ion release. SEM findings demonstrated that the surface of cpTi exhibited micro-pitting as well as the presence of viable OCs. Correspondingly, cpTi that had been exposed to OCs exhibited reduced levels of Ti, oxygen, and oxides within the corroded regions relative to smooth Ti as measured via EDS and XPS. OC exposure was also associated with significant changes in cpTi surface roughness, a significant decrease in corrosion resistance, and a significant increase in the release of Ti ions into the surrounding medium. In summary, these findings indicate that OC culture on the surface of cpTi can directly corrode titanium and lead to the release of Ti ions.

Biocorrosion of pure and SLA titanium surfaces in the presence of Porphyromonas gingivalis and its effects on osteoblast behavior.

Objective: The study aims to investigate the biocorrosion behavior of Porphyromonas gingivalis on pure and SLA titanium surfaces and its effects on surface characteristics and osteoblast behavior. Methods: Pure and SLA titanium specimens were immersed in culture medium with P. gingivalis and incubated for 7 days. P. gingivalis colonization on the pure and SLA titanium surfaces was observed by scanning electron microscopy (SEM). The pure and SLA titanium surface characteristics were analyzed via X-ray photoelectron spectroscopy (XPS), surface roughness and surface wettability. The corrosion behaviors of pure and SLA titanium specimens were evaluated by electrochemical corrosion test. The osteoblast behavior of MC3T3-E1 cells on the pure and SLA titanium surfaces after P. gingivalis colonization was investigated by cell adhesion and western blot assays. Results: P. gingivalis colonized on the pure and SLA titanium surfaces was observed by SEM. The XPS analysis demonstrated reductions in the relative levels of titanium and oxygen and obvious reductions of dominant titanium dioxide (TiO2) on both titanium surfaces after immersing the metal in P. gingivalis culture. In addition, their roughness and wettability were changed. Correspondingly, the electrochemical corrosion test results revealed significant decreases in the corrosion resistance and increases in the corrosion rate of the pure and SLA titanium specimens after immersion in P. gingivalis culture. The results of the in vitro study showed that the pre-corroded pure and SLA titanium surfaces by P. gingivalis exhibited lower osteocompatibility and down-regulated the adhesion, spreading and osteogenic differentiation abilities of MC3T3-E1 cells. Conclusions: P. gingivalis was able to colonize on the pure and SLA titanium surfaces and weaken their surface properties, especially a decrease in the protective TiO2 film, which induced the biocorrosion and further negatively affected the osteoblast behavior.

Mitophagy is a protective response against oxidative damage in bone marrow mesenchymal stem cells.

AIMS: Bone marrow mesenchymal stem cells (BMSCs) show great potential in clinical applications such as in intervertebral disc degeneration. Nevertheless, environmental stress during the BMSC transplant or in the injured tissues is a catastrophic factor that causes cell toxicity and poor survival of BMSCs. Mitophagy plays a vital role in maintaining cellular homeostasis and defending against oxidative stress because this process could control mitochondrial quality and quantity by eliminating dysfunctional or damaged mitochondria that can cause cell death. However, the accurate mechanisms of mitophagy in protecting BMSCs against the harshness of oxidative stress remain largely unknown. MAIN METHODS: BMSCs were treated with H2O2 for various time periods. Mitophagy response was evaluated through the expression levels of LC3-II, p62 and mitophagosomal formation by using Western blot and fluorescence analysis. Cell apoptosis was examined by flow cytometry and TUNEL assay. The interactions of mitophagy and apoptosis and the possible signalling pathways were investigated through the co-treatment of mitophagy inhibitor or mitophagy activator with H2O2. KEY FINDINGS: Oxidative stress rapidly facilitated mitophagy through JNK at an early stage but decreased mitophagy and increased apoptosis at a late stage. Furthermore, mitophagy inhibition significantly enhanced the apoptosis in the cells treated by H2O2. SIGNIFICANCE: Induced mitophagy may play pivotal roles in protecting cells against oxidative stress in BMSCs.

Streptococcus agalactiae Inhibits Candida albicans Hyphal Development and Diminishes Host Vaginal Mucosal TH17 Response.

Streptococcus agalactiae and Candida albicans often co-colonize the female genital tract, and under certain conditions induce mucosal inflammation. The role of the interaction between the two organisms in candidal vaginitis is not known. In this study, we found that co-infection with S. agalactiae significantly attenuated the hyphal development of C. albicans, and that EFG1-Hwp1 signal pathway of C. albicans was involved in this process. In a mouse model of vulvovaginal candidiasis (VVC), the fungal burden and the levels of pro-inflammatory cytokines, IL-1ß, IL-6 and TNF-α showed a increase on co-infection with S. agalactiae, while the level of TH17 T cells and IL-17 in the cervicovaginal lavage fluid were significantly decreased. Our results indicate that S. agalactiae inhibits C. albicans hyphal development by downregulating the expression of EFG1-Hwp1. The interaction between S. agalactiae and C. albicans may attenuate host vaginal mucosal TH17 immunity and contribute to mucosal colonization by C. albicans.

[Determination of trace Pb in whole blood by Zeeman-GFAAS].

The determination method for trace Pb in whole blood was studied, which was diluted by 0.5% HNO3. In the measurement, Zeeman-GFAAS was used and the relative condition was discussed. This method shows that the detection limit was 10.0 pg, the relative standard deviation of standards (RSD) was 0.36%-1.8%, the relative standard deviation of samples (RSD) was 1.4%-2.3%, and the recovery rate was 96.0%-101.7%. The concurrent interference was low. This method is simple and rapid. It is an ideal method to determine trace Pb in whole blood.

Decreased expression of follicular dendritic cell-secreted protein correlates with increased immunoglobulin A production in the tonsils of individuals with immunoglobulin A nephropathy.

Immunoglobulin A nephropathy (IgAN) is characterized by a qualitative abnormality of IgA in the circulation and IgA deposition in the renal mesangium. Recent research has indicated that pathogenic IgA may originate from affected tonsils. Follicular dendritic cell-secreted protein (FDC-SP), a small novel secretory protein that may regulate the induction of B-cell responses, has been suggested to control IgA production. Given this background, this study investigated the expression of FDC-SP and its correlation with IgA production in the tonsils of IgAN patients. Immunohistochemistry and reverse transcription-polymerase chain reaction were used to compare the expression of FDC-SP in the tonsils of IgAN patients with tonsillitis and of non-IgAN patients with chronic tonsillitis. The location of FDC-SP in tonsillar tissue was confirmed by double immunofluorescence. We found that FDC-SP expression significantly decreased and was correlated negatively with enhanced IgA production in the tonsils of IgAN patients. FDC-SP secreted by follicular dendritic cells may act on germinal center B cells and participate in the modulation of IgA generation in the tonsils. Our study demonstrated that FDC-SP may be involved in IgA production in the tonsils of IgAN patients, making this protein an attractive candidate immunomodulator, and highlighting a promising strategy for therapeutic intervention in IgAN.