Hypoxic conditioned medium derived from bone marrow mesenchymal stromal cells protects against ischemic stroke in rats

In recent years, studies have shown that the secretome of bone marrow mesenchymal stromal cells (BMSCs) contains many growth factors, cytokines, and antioxidants, which may provide novel approaches to treat ischemic diseases. Furthermore, the secretome may be modulated by hypoxic preconditioning. We hypothesized that conditioned medium (CM) derived from BMSCs plays a crucial role in reducing tissue damage and improving neurological recovery after ischemic stroke and that hypoxic preconditioning of BMSCs robustly improves these activities. Rats were subjected to ischemic stroke by middle cerebral artery occlusion and then intravenously administered hypoxic CM, normoxic CM, or Dulbecco modified Eagle medium (DMEM, control). Cytokine antibody arrays and label-free quantitative proteomics analysis were used to compare the differences between hypoxic CM and normoxic CM. Injection of normoxic CM significantly reduced the infarct area and improved neurological recovery after stroke compared with administering DMEM. These outcomes may be associated with the attenuation of apoptosis and promotion of angiogenesis. Hypoxic preconditioning significantly enhanced these therapeutic effects. Fourteen proteins were significantly increased in hypoxic CM compared with normoxic CM as measured by cytokine arrays. The label-free quantitative proteomics analysis revealed 163 proteins that were differentially expressed between the two groups, including 107 upregulated proteins and 56 downregulated proteins. Collectively, our results demonstrate that hypoxic CM protected brain tissue from ischemic injury and promoted functional recovery after stroke in rats and that hypoxic CM may be the basis of a potential therapy for stroke patients.     

BI1 alleviates cardiac microvascular ischemia-reperfusion injury via modifying mitochondrial fission and inhibiting XO/ROS/F-actin pathways

Pathogenesis of cardiac microvascular ischemia-reperfusion (IR) injury is associated with excessive mitochondrial fission. However, the upstream mediator of mitochondrial fission remains obscure. Bax inhibitor 1 (BI1) is linked to multiple mitochondrial functions, and there have been no studies investigating the contribution of BI1 on mitochondrial fission in the setting of cardiac microvascular IR injury. This study was undertaken to establish the action of BI1 on the cardiac microvascular reperfusion injury and figure out whether BI1 sustained endothelial viability via inhibiting mitochondrial fission. Our observation indicated that BI1 was downregulated in reperfused hearts and overexpression of BI1 attenuated microvascular IR injury. Mechanistically, reperfusion injury elevated the levels of xanthine oxidase (XO), an effect that was followed by increased reactive oxygen species (ROS) production. Subsequently, oxidative stress mediated F-actin depolymerization and the latter promoted mitochondrial fission. Aberrant fission caused mitochondrial dysfunction and ultimately activated mitochondrial apoptosis in cardiac microvascular endothelial cells. By comparison, BI1 overexpression repressed XO expression and thus neutralized ROS, interrupting F-actin-mediated mitochondrial fission. The inhibitory effect of BI1 on mitochondrial fission sustained endothelial viability, reversed endothelial barrier integrity, attenuated the microvascular inflammation response, and maintained microcirculation patency. Altogether, we conclude that BI1 is essential in maintaining mitochondrial homeostasis and alleviating cardiac microvascular IR injury. Deregulated BI1 via the XO/ROS/F-actin pathways plays a causative role in the development of cardiac microvascular reperfusion injury.     

Altering microtubule stability affects microtubule clearance and nuclear extrusion during erythropoiesis

Mammalian erythrocytes are highly specialized cells that have adapted to lose their nuclei and cellular components during maturation to ensure oxygen delivery. Nuclear extrusion, the most critical event during erythropoiesis, represents an extreme case of asymmetric partitioning that requires a dramatic reorganization of the cytoskeleton. However, the precise role of the microtubule cytoskeleton in the enucleation process remains controversial. In this study, we show that microtubule reorganization is critical for microtubule clearance and nuclear extrusion during erythropoiesis. Using a rodent anemia model, we found that microtubules were present in erythroblasts and reticulocytes but were undetectable in erythrocytes. Further analysis demonstrated that microtubules became disordered in reticulocytes and revealed that microtubule stabilization was critical for tubulin degradation. Disruption of microtubule dynamics using the microtubule-stabilizing agent paclitaxel or the microtubule-destabilizing agent nocodazole did not affect the efficiency of erythroblast enucleation. However, paclitaxel treatment resulted in the retention of tubulin in mature erythrocytes, and nocodazole treatment led to a defect in pyrenocyte morphology. Taken together, our data reveals a critical role for microtubules in erythrocyte development. Our findings also implicate the disruption of microtubule dynamics in the pathogenesis of anemia-associated diseases, providing new insight into the pathogenesis of the microtubule-targeted agent-associated anemia frequently observed during cancer chemotherapy.     

Long noncoding RNA CPS1-IT1 suppresses melanoma cell metastasis through inhibiting Cyr61 via competitively binding to BRG1

Long noncoding RNA CPS1-IT1 is recently recognized as a tumor suppressor in several cancers. Here, we investigate the role of CPS1-IT1 in human melanoma. Presently, our study reveals the low expression of CPS1-IT1 in human melanoma tissues and cell lines, which is significantly associated with metastasis and tumor stage. Besides, the potential of CPS1-IT1 as a prognosis-predictor is strongly indicated. Functionally, CPS1-IT1 overexpression inhibits cell migration, invasion, epithelial–mesenchymal transition, and angiogenesis in melanoma cells. CYR61, an angiogenic factor that participates in tumor metastasis as well as a recognized oncogene in melanoma, is shown to be confined under CPS1-IT1 overexpression in melanoma cells. Furthermore, enforced expression of Cyr61 in CPS1-IT1-silenced melanoma cells dramatically normalized the protein level of Cyr61 and that of its downstream targets vascular endothelial growth factor and matrix metalloproteinase-9, as well as the repressive effect of CPS1-IT1 overexpression on melanoma cell metastasis. BRG1, a core component of SWI/SNF complex, is implied to interact with both CPS1-IT1 and Cyr61 in melanoma cells. Moreover, CPS1-IT1 negatively regulates Cyr61 expression by blocking the binding of BRG1 to Cyr61 promoter. Jointly, CPS1-IT1 controls melanoma metastasis through impairing Cyr61 expression via competitively binding with BRG1, uncovering a novel potential therapeutic and prognostic biomarker for patients with melanoma.     

Retracted: Impaired Th17 cell proliferation and decreased pro-inflammatory cytokine production in CXCR3/CXCR4 double-deficient mice of vulvovaginal candidiasis

Vulvovaginal candidiasis (VVC) is a common observed infection, affecting approximately 75% of women of reproductive age. Drug resistance represents a troublesome stumbling block associated with VVC therapy. Thus the aim of the present study was to provide information regarding the selection of potential drug targets for VVC. CXCR3-, CXCR4-, or CXCR/CXCR4 double-deficient mouse models of VVC were subsequently established, with changes to the load of Candida Albicans evaluated accordingly. The biological behaviors of the vaginal epithelial cells were characterized in response to the CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout in vivo. Our initial observations revealed that in mice with VVC, CXCR3-, CXCR4-, or CXCR3 - CXCR4 double-knockout resulted in a decreased load of C. Albicans as well as reduced levels and proportion of Th17 cells. Proinflammatory cytokine production was found to be inhibited by CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout whereby the mRNA and protein expressions CXCR3, CXCR4, IL-17, IL-6, and TNF-α exhibited decreased levels. CXCR3-, CXCR4-, or CXCR3/CXCR4 double-knockout appeared to function as positive proliferation factors, while playing a negative role in the processes of apoptosis and the cell cycle of vaginal epithelial cells. Taken together, the key findings of the study suggested that CXCR3/CXCR4 double-knockout could act to hinder the progression of VVC, highlighting its promise as a novel therapeutic target in the treatment of VVC. CXCR3 and CXCR4 genes may regulate Th17/IL-17 immune inflammatory pathways to participate in antifungal immunity.     

Retracted: miR-150 might inhibit cell proliferation and promote cell apoptosis by targeting LMO4 in Burkitt lymphoma

This study aimed at investigating the effect of microRNA-150 (miR-150) on cell proliferation of Burkitt lymphoma and its molecular mechanism. Gene expression analysis was applied to identify target genes of miR-150 in Burkitt lymphoma cell line ST486 based on the dataset from the Gene Expression Omnibus (GEO) datasets GSE86432. miRNA mimics, inhibitor and small interfering RNA (siRNA) were fluorescently labeled by Cy3, whereas plasmid vector was labeled by EGFP. Cells were viewed by fluorescence microscope and transfection efficiency was evaluated through fluorescent cell percentage. Quantitative real-time polymerase chain reaction analysis (qRT-PCR) and western blot were applied to detect the expression level of miR-150 and LMO4. Cell proliferation, cell cycle, and apoptosis were explored by CCK-8, flow cytometry. Targeting relationship was validated by the Luciferase reporter assay. Tumor xenograft and immunohistochemical analysis were conducted in nude mice model. In Burkitt lymphoma cells, miR-150 expression was significantly lower than normal ones, whereas the expression of LMO4 was upregulated. miR-150 might inhibit cell proliferation and promoted apoptosis in Burkitt lymphoma deterioration by downregulating LMO4. The results of tumor xenograft further confirmed the role of miR-150 in Burkitt lymphoma. Targeting LMO4 is a significant mechanism by which miR-150 suppresses cell growth and promotes apoptosis in Burkitt lymphoma cells, thus may provide a novel target for Burkitt lymphoma therapy in the future.     

PVT1 (rs13281615) and miR-146a (rs2910164) polymorphisms affect the prognosis of colon cancer by regulating COX2 expression and cell apoptosis

In this study, we aimed to investigate the potential correlation between rs13281615/rs2910164 polymorphisms and the prognosis of colon cancer (CC). Taqman was utilized to genotype the rs13281615/rs2910164 polymorphisms in recruited subjects. Kaplan–Meier survival curves were calculated to study the prognostic values of different genotypes of rs13281615/rs2910164 polymorphisms. Real-time polymerase chain reaction, enzyme-linked immunosorbent assay, immunohistochemistry, and terminal deoxynucleotidyl transferase dUTP nick-end labeling assays were conducted to establish a potential signaling pathway underlying the role of rs13281615/rs2910164 polymorphisms, whereas bioinformatics analysis and luciferase reporter assays were performed to identify plasmacytoma variant translocation 1 (PVT1) and cyclooxygenase-2 (COX2) as targets of microRNA-146a (miR-146a). No significant difference was observed in respect to clinical characteristics among subjects with different genotypes. However, patients genotyped as GG/CC + GC showed the lowest chance of survival, whereas patients of GA + AA/GG genotype showed the highest chance of survival. Moreover, the relative expressions of PVT1, prostaglandin E2 (PGE2), and COX2 were the lowest and the relative expression of miR-146a was the highest in GA + AA/GG subjects, validating the roles of PVT1, miR-146a, and COX2 in CC. In addition, both PVT1 and COX2 were identified as virtual targets of miR-146a, and the luciferase activities of cells cotransfected with wild-type PVT1/COX2 and miR-146a mimics were significantly reduced. Moreover, the presence of PVT1 decreased the level of miR-146a whereas increasing the messenger RNA and protein levels of COX2, thus establishing a PVT1/miR-146a/COX2 signaling pathway underlying the pathogenesis of CC. The presence of rs13281615 G > A polymorphism on PVT1 and the rs2910164 C > G polymorphism on miR-146a contributes to a favorable prognosis in CC patients via modulating the activity of the PVT1/miR-146a/COX2 signaling pathway.     

Expression profile of circular RNA in rat intimal hyperplasia and target gene prediction

Intimal hyperplasia is an important cause of stenosis or occlusion after vascular injury. Circular RNAs (circRNAs) are known to be related to various cardiovascular diseases. However, the expression profile of circRNAs in the neointima has not been reported in detail. In this study, we established a rat common carotid artery (CCA) injury model. A microarray detection showed significant differences in circRNA expression between the normal and injured CCA. Real-time quantitative polymerase chain reaction verified the differences. We used bioinformatics to predict the microRNAs that possibly interact with the differentially expressed (DE) circRNAs and linked the potential functions of circRNAs to the target genes of the microRNAs. We believe that the DE circRNA in neointima may affect the differentiation, proliferation, and migration of vascular cells through a variety of target genes. The intervention or utilization of certain circRNAs should be a new method for preventing and treating intimal hyperplasia.     

Galangin ameliorates cardiac remodeling via the MEK1/2–ERK1/2 and PI3K–AKT pathways

Cardiac remodeling is associated with inflammation and apoptosis. Galangin, as a natural flavonol, has the potent function of regulating inflammation and apoptosis, which are factors related to cardiac remodeling. Beginning 3 days after aortic banding (AB) or Sham surgery, mice were treated with galangin for 4 weeks. Cardiac remodeling was assessed according to echocardiographic parameters, histological analyses, and hypertrophy and fibrosis markers. Our results showed that galangin administration attenuated cardiac hypertrophy, dysfunction, and fibrosis response in AB mice and angiotensin II-treated H9c2 cells. The inhibitory action of galangin in cardiac remodeling was mediated by MEK1/2–extracellular-regulated protein kinases 1/2 (ERK1/2)–GATA4 and phosphoinositide 3-kinase (PI3K)–protein kinase B (AKT)–glycogen synthase kinase 3β (GSK3β) activation. Furthermore, we found that galangin inhibited inflammatory response and apoptosis. Our findings suggest that galangin protects against cardiac remodeling through decreasing inflammatory responses and apoptosis, which are associated with inhibition of the MEK1/2–ERK1/2–GATA4 and PI3K–AKT–GSK3β signals.     

miR-548c-5p inhibits colorectal cancer cell proliferation by targeting PGK1

Accumulating studies have implicated that microRNAs (miRNAs) are involved in the pathogenesis of colorectal cancer (CRC). However, the role of miR-548c-5p, a novel identified miRNA in malignancies, in colorectal carcinogenesis remains largely unknown. The present study is aimed to investigate the effect and molecular mechanism of miR-548c-5p in CRC by a sequence of cellular experiments. miR-548c-5p was significantly downregulated, whereas phosphoglycerate kinase 1 (PGK1), a key enzyme for glycolysis, was obviously upregulated in peripheral blood mononuclear cells and cancer tissues from patients with CRC. Besides, miR-548c-5p and PGK1 were negatively associated with each other. The luciferase reporter assay revealed that PGK1 was a targeted gene of miR-548c-5p. Moreover, the proliferation and generation of inflammatory cytokines (TNF-α and IL-6) were significantly inhibited in miR-548c-5p-overexpressed SW480 CRC cells stimulated by lipopolysaccharide (LPS). Accordingly, miR-548c-5p may serve as a cancer suppressor in CRC by targeting PGK1.