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Osteoarthritis (OA) is a degenerative joint disease characterized by destruction of articular cartilage. The inflammatory response is the most important factor affecting the disease process. As interleukin‐1β (IL‐1β) stimulates several key mediators in the inflammatory response, it plays a major role in the pathogenesis of OA. Maslinic acid (MA) is a natural compound distributed in olive fruit. Previous studies have found that maslinic acid has an inhibitory effect on inflammation, but its specific role in the progression of OA disease has not been studied so far. In this study, we aim to assess the protective effect of MA on OA progression by in vitro and in vivo experiments. Our results indicate that, in IL‐1β‐induced inflammatory response, MA is effective in attenuating some major inflammatory mediators such as nitric oxide (NO) and prostaglandin E2, and inhibits the expression of IL‐6, inducible nitric oxide synthase, cyclooxygenase‐2, and tumor necrosis factor‐α (TNF‐α) in a concentration‐dependent manner. Also, MA downregulated the expression levels of thrombospondin motif 5 (ADAMTS5) and matrix metalloproteinase 13 in chondrocytes, resulting in reduced degradation of its extracellular matrix. Mechanistically, MA exhibits an anti‐inflammatory effect by inactivating the PI3K/AKT/NF‐κB pathway. In vivo, the protective effect of MA on OA development can be detected in a surgically induced mouse OA model. In summary, these findings suggest that MA can be used as a safe and effective potential OA therapeutic strategy. [ABSTRACT FROM AUTHOR]

Although it is generally accepted that diabetes is one of the most important risk factors for liver cancer, the underlying mechanism is still not well understood. The purpose of the current study is to further investigate how high concentrations of glucose (HG), a major symptom of diabetes, stimulate the development of liver malignancy. Using data mining, gap junction protein gamma 1 (GJC1) was identified as a critical proto‐oncoprotein that is essential for the HG stimulation of proliferative capacity in liver cancer cells. Furthermore, enhanced transcriptional expression of GJC1 might occur after stimulation by HG. A transcription factor zinc finger protein 410 (APA1)–binding motif was found to be located at the –82 to −77 nt region within the GJC1 promoter. Without APA1, HG was unable to increase GJC1 expression. Interestingly, APA1, but not GJC1, can be O‐GlcNAcylated in liver cancer cells. Moreover, O‐GlcNAcylation is essential for HG‐induced APA1 binding to the GJC1 promoter. Notably, global O‐GlcNAcylation and expression of APA1 and GJC1 were highly elevated in liver cancer patients with diabetes compared to those in patients without diabetes. The HG‐stimulated proliferative capacity was abolished upon decreasing O‐GlcNAcylation, which could be reversed gradually by the simultaneous overexpression of APA1 and GJC1. Therefore, GJC1 could be a potential target for preventing liver cancer in patients with diabetes. High glucose controls GJC1 to induce tumorigenesis. [ABSTRACT FROM AUTHOR]

High mobility group box 1 (HMGB1) is a nuclear protein that can be released from activated or dead cells. Extracellular HMGB1 can serve as a 'danger signal' and novel cytokine that mediates sterile inflammation. In addition to its soluble form, extracellular HMGB1 can also be carried by membrane microvesicles. However, the cellular mechanisms responsible for nuclear HMGB1 translocation to the plasma membrane and release onto membrane microvesicles have not been investigated. Tobacco smoking is a major cause of sterile inflammation in many diseases. Smoking also increases blood levels of HMGB1. In this study, we found that exposure of macrophages to tobacco smoke extract (TSE) stimulated HMGB1 expression, redistribution, and release into the extracellular milieu both as a soluble molecule and, surprisingly, as a microvesicle-associated form (TSE-MV). Inhibition of chromosome region maintenance-1 (CRM1), a nuclear exporter, attenuated TSE-induced HMGB1 redistribution from the nucleus to the cytoplasm, and then its release on TSE-MVs. Our study demonstrates a novel mechanism for the translocation of nuclear HMGB1 to the plasma membrane, and then its release in a microvesicle-associated form. J. Cell. Physiol. 231: 2319-2326, 2016. © 2016 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The latent TGF-β binding proteins (LTBP-1 -3, and -4) assist in the secretion and localization of latent TGF-β molecules. Ltbp3and Ltbp4S mice have distinct phenotypes and only in the lungs does deficiency of either Ltbp-3 or Ltbp-4 cause developmental abnormalities. To determine if these two LTBPs have additional common functions, we generated mice deficient for both Ltbp-3 and Ltbp-4S. The only novel defect in Ltbp3; Ltbp4S mice was an early lethality compared to mice with single mutations. In addition lung abnormalities were exacerbated and the terminal air sac septation defect was more severe in Ltbp3; Ltbp4S mice than in Ltbp4S mice. Decreased cellularity of Ltbp3; Ltbp4S lungs was correlated with higher rate of apoptosis in newborn lungs of Ltbp3; Ltbp4S animals compared to WT, Ltbp3, and Ltbp4S mice. No differences in the maturation of the major lung cell types were discerned between the single and double mutant mice. However, the distribution of type 2 cells and myofibroblasts was abnormal, and myofibroblast segregation in some areas might be an indication of early fibrosis. We also observed differences in ECM composition between Ltbp3; Ltbp4S and Ltbp4S lungs after birth, reflected in decreased incorporation of fibrillin-1 and -2 in Ltbp3; Ltbp4S matrix. The function of the lungs of Ltbp3; Ltbp4S mice after the first week of life was potentially further compromised by macrophage infiltration, as proteases secreted from macrophages might exacerbate developmental emphysema. Together these data indicate that LTBP-3 and -4 perform partially overlapping functions only in the lungs. J. Cell. Physiol. 226: 1499-1509, 2011. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Diabetes is associated with neurological complications, and accumulated evidence shows that biological pathways in diabetes are targeted by noncoding RNA transcripts. In this study, the role of long intergenic noncoding RNA (lincRNA) p21/microRNA‐221 (miR‐221)/fructooligosaccharide (FOS) axis was investigated in the mice with diabetes treatment. The streptozotocin‐induced diabetic mouse model was established. The learning ability and the pathological changes in mice were analyzed. After that, the interaction among miR‐221, lincRNA p21, and FOS was explored and verified. The subcellular location of lincRNA p21 was identified. Finally, the cell cycle and apoptosis of the hippocampus neurons were measured. In the diabetic mice, the levels of blood glucose were higher and the leaning abilities were inhibited. miR‐221 was highly expressed in the diabetic mice whereas lincRNA p21 and FOS were poorly expressed. miR‐221 could bind with both lincRNA p21 and FOS. miR‐221 silencing or lincRNA p21 overexpression in the diabetes mice reduced the cell apoptosis rate, and the expression of Bax and cleaved Caspase‐3, whereas increase the Bcl‐2 expression. Overexpression of lincRNA p21 promotes FOS expression by binding to miR‐221, thereby, inhibiting hippocampal neuron apoptosis in diabetic mice. This may offer potential targets for diabetes. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the most common malignancies in women worldwide. Triple‐negative breast cancer (TNBC) is a highly aggressive and metastatic subtype that has the characteristics of easy recurrence, poor prognosis as well as lack of targeted therapeutics. Snail1, a key factor regulating epithelial–mesenchymal transition (EMT) process, contributing to metastasis and chemoresistance in human cancers. However, the molecular mechanism of Snail1 stabilization in cancers is not fully understood. Here, we demonstrate that the deubiquitinating enzyme USP9X deubiquitinates and stabilizes Snail1, thereby promoting metastasis and chemoresistance. The depletion and pharmacological inhibition of USP9X by WP1130, an inhibitor of USP9X, downregulate endogenous Snail1 protein, inhibit cell migration, invasion, metastasis, and increase cellular sensitivity to cisplatin and paclitaxel both in vitro and in vivo, whereas the reconstitution of Snail1 in cells with USP9X depletion at least partially reverses these phenotypes. Overall, our study establishes the USP9X‐Snail1 axis as an important regulatory mechanism of breast cancer metastasis and chemoresistance and provides a rationale for potential therapeutic interventions in the treatment of TNBC. [ABSTRACT FROM AUTHOR]

Hypoxia‐inducible factor 2α (HIF2α) plays a pivotal role in breast tumor growth and metastasis. However, the regulatory mechanisms of HIF2α protein stability remain poorly understood. The precise role of the deubiquitinase (DUB) ubiquitin‐specific peptidase 5 (USP5) in breast cancer and the underlying mechanism remains largely unknown. Here, we identified USP5 as a novel DUB for HIF2α. Physically, USP5 interacts with HIF2α and protects HIF2α from ubiquitin‐proteasome degradation, thereby promoting the transcription of HIF2α target genes, such as SLC2A1, PLOD2, P4HA1, and VEGFA. USP5 ablation impairs breast cancer cells proliferation, colony formation, migration, and invasion. Moreover, USP5 is highly expressed in breast cancer, and the protein levels of USP5 are positively correlated with HIF2α protein levels in human breast cancer tissues. Importantly, high levels of USP5 leads to poor clinical outcome in patients with breast cancer. Collectively, USP5 stabilizes HIF2α through its DUB activity and provides a potential therapeutic target for breast cancer. [ABSTRACT FROM AUTHOR]

Cardiomyocyte apoptosis induced by hypoxia and ischemia plays important roles in heart dysfunction after acute myocardial infarction (AMI). However, the mechanism of apoptosis induction remains unclear. A previous study reported that Y‐box protein 1 (YB1) is upregulated after myocardial hypoxia/reoxygenation or ischemia/reperfusion (H/R or I/R, respectively) injury; however, whether YB1 is associated with H/R‐induced cardiomyocyte apoptosis is completely unknown. In the present study, we investigated the roles of YB1 in H/R‐induced cardiomyocyte apoptosis and the possible underlying molecular mechanisms. In vitro, H/R treatment upregulated the YB1 expression in H9C2 cells, whereas YB1 knockdown inhibited H/R‐induced cardiomyocyte apoptosis and induced H9C2 cell proliferation via Src homology region 2 domain‐containing phosphatase 1 (SHP‐1)‐mediated activation of signal transducer and activator of transcription 3 (STAT3). In vivo, YB1 knockdown ameliorated AMI, reducing infarct size, cardiomyocyte apoptosis, and oxidative stress, via SHP‐1‐mediated inactivation of STAT3. Additionally, YB1 knockdown inhibited H/R‐ or I/R‐induced oxidative stress in vitro and in vivo. H/R and I/R increase YB1 expression, and YB1 knockdown ameliorates AMI injury via SHP‐1‐dependent STAT3 inactivation. [ABSTRACT FROM AUTHOR]

Acute myocardial infarction (AMI), as a severe consequence of coronary atherosclerotic heart disease, always contributes to the loss of myocardial cells. Mounting evidence shows that annexin protects the myocardium from ischemic injury. In this study, we examine the inhibition of annexin A3 (ANXA3) on AMI through the phosphatidylinositide 3‐kinase/protein kinase B (PI3K/Akt) signaling pathway. We selected rats to build an AMI model which was then assigned into different groups. The hemodynamic parameters after transfection were detected by using enzyme‐linked immunosorbent assay. The effect of silencing of ANXA3 on inflammatory reaction and the PI3K/Akt signaling pathway was assessed. Rats transfected with ANXA3‐short hairpin RNA had alleviated hemodynamics, inflammatory reaction, decreased infarct size, α‐smooth muscle actin, Collagen I, and Collagen III as well as an increased vascular endothelial growth factor. Silencing ANAX3 would promote repair and healing of myocardial tissue by activation of the PI3K/Akt signaling pathway. Collectively, our study provides evidence that the downregulation of ANXA3 promotes the repair and healing of myocardial tissues by activating the PI3K/Akt signaling pathway. Collectively, our study provides evidence that the downregulation of ANXA3 promotes the repair and healing of myocardial tissues by activating the PI3K/Akt signaling pathway. [ABSTRACT FROM AUTHOR]

Dysfunction of the intestinal barrier function occurs in hepatic injury, but the specific mechanisms responsible are largely unknown. Recently, NOD‐like receptor 3 (NLRP3) inflammasome functions in impairing endothelial barrier function. In this study, we test the hypothesis that TXNIP–NLRP3 axis repression prevents against intestinal barrier function disruption in nonalcoholic steatohepatitis (NASH). First, lipopolysaccharide (LPS)‐induced alterations in expression of ZO‐1 and occludin, myeloperoxidase (MPO) activity, reactive oxygen species (ROS) level, and transepithelial electric resistance (TEER) in intestinal epithelial cells (IECs) isolated from C57BL/6 wild‐type (WT) and TXNIP−/− mice were evaluated. The underlying regulatory mechanisms of TXNIP knockout in vivo were investigated with the detection of expressions of TXNIP, NLRP3 and ZO‐1, and occludin, the interaction of TXNIP–NLRP3, MPO activity, ROS level, permeability of intestinal mucosa, levels of inflammatory factors in serum, and LPS concentration. We identified that TXNIP knockout promoted ZO‐1 and occludin expression, yet reduced MPO activity, ROS level, and cell permeability in IECs, indicating restored the intestinal barrier function. However, LPS upregulated TXNIP and NLRP3 expression, as well as contributed to the interaction between TXNIP and NLRP3 in vitro. Furthermore, TXNIP was significantly upregulated in the intestinal mucosa of NASH mice and its knockout repaired the intestinal barrier disrupt, inhibited expression of inflammatory factors, and reduced LPS concentration as well as hepatic injury in vivo. Taken together, our findings demonstrated that inhibited the activation of the TXNIP–NLRP3 axis reduced MPO activity and oxidative stress and thus restoring the intestinal barrier function in NASH. TXNIP–NLRP3 axis may be a promising therapeutic strategy for the NASH treatment. Taken together, our findings demonstrated that inhibited activation of the TXNIP–NLRP3 axis reduced myeloperoxidase (MPO) activity and oxidative stress and thus restored the intestinal barrier function in nonalcoholic steatohepatitis (NASH). TXNIP–NLRP3 axis may be a promising therapeutic strategy for the NASH treatment. [ABSTRACT FROM AUTHOR]

This study aims to evaluate the effects of PSMA7 silencing on cervical cancer (CC) cell proliferation and vascular endothelial growth factor (VEGF) expression through the ubiquitin‐proteasome pathway. CC tissues (n = 43) and normal tissues (n = 27) were first collected from patients. Human CC cell line (SiHa) and human normal cervical epithelial cells (H8) were obtained and classified into the normal, blank, negative control (NC), PSMA7‐shRNA1, and PSMA7‐shRNA2 groups, respectively. In situ hybridization was used to detect the expressions of wild‐type and mutant p53 proteins. Immunofluorescence assay was carried out to test the activity of 20S proteasomes. Reverse transcription quantitative polymerase chain reaction and Western blot analysis were both performed to determine the expressions of PSMA7, ubiquitin, P27, P53, and VEGF in sample tissues and cells. 3‐(4, 5‐dimethylthiazol‐2‐yl)‐2, 5‐diphenyltetrazolium bromide (MTT) assay was used to analyze cell proliferation rates, and flow cytometry was used to analyze the cell cycle and the apoptotic rate. Compared with normal tissues, CC tissues showed increased expression levels of PSMA7, ubiquitin, p53, VEGF as well as increased activity of 20S proteasomes but exhibited a decrease in p27 expression. Compared with the blank and NC groups, the PSMA7‐shRNA1 and PSMA7‐shRNA2 groups all had decreased expression levels of PSMA7, ubiquitin, p53, and VEGF as well as decreased cell proliferation, 20S proteasomes activity, and cell number in the S phase, increased p27 expression, cell apoptosis and cell number in the G0/G1 phase. Our study demonstrated that PSMA7 silencing can suppress CC cell proliferation and VEGF expression in addition to promoting cell apoptosis through inhibiting the UPP signaling pathway. [ABSTRACT FROM AUTHOR]

Ovarian cancer (OC) is a lethal gynecologic tumor, which brings its mortality to the head. CXCL12 and its receptor chemokine receptor 4 (CXCR4) have been found to be highly expressed in OC and contribute to the disease progression by affecting tumor cell proliferation and invasion. Here, in this study, we aim to explore whether the blockade of CXCL12–CXCR4 axis with AMD3100 (a selective CXCR4 antagonist) has effects on the progression of OC. On the basis of the gene expression omnibus database of OC gene expression chips, the OC differentially expressed genes were screened by microarray analysis. OC (nonmetastatic and metastatic) and normal ovarian tissues were collected to determine the expressions of CXCL12 and CXCR4. A series of AMD3100, shRNA against CXCR4, and pCNS‐CXCR4 were introduced to treat CAOV3 cells with the highest CXCR4 was assessed. Cell viability, apoptosis, migration, and invasion were all evaluated. The microarray analysis screened out the differential expression of CXCL12–CXCR4 in OC. CXCL12 and CXCR4 expressions were increased in OC tissues, particularly in the metastatic OC tissues. Downregulation of CXCR4 by AMD3100 or shRNA was observed to have a critical role in inhibiting cell proliferation, migration, and invasion of the CAOV3 OC cell line while promoting cell apoptosis. Overexpressed CXCR4 brought significantly promoting effects on the proliferation and invasiveness of OC cells. These results reinforce that the blockade of CXCL12–CXCR4 axis with AMD3100 inhibits the growth of OC cells. The antitumor role of the inhibition of CXCL12–CXCR4 axis offers a preclinical validation of CXCL12–CXCR4 axis as a therapeutic target in OC. The antitumor role of the inhibition of CXCL12–CXCR4 axis offers a preclinical validation of CXCL12–CXCR4 axis as a therapeutic target in OC. [ABSTRACT FROM AUTHOR]

Breast cancer is known as the most prevalent cancer in women worldwide, and has an undeniable negative impact on public health, both physically, and mentally. This study aims to investigate the effects of toll‐like receptor 4 (TLR4) gene silencing on proliferation and apoptosis of human breast cancer cells to explore for a new theoretical basis for its treatment. TLR4 small interference RNA (siRNA) fragment recombinant plasmids were constructed, including TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3. Human breast cancer MCF‐7 and MDA‐MB‐231 cells were assigned into blank, negative control (NC), TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups. MCF‐7 and MDA‐MB‐231 cell growth was detected by MTT assay. Apoptosis and cell cycle were determined by flow cytometry. Reverse transcription quantitative polymerase chain reaction (RT‐qPCR) and Western blot analysis were conducted to determine the expression of TLR4, CDK4, cyclin D1, Livin, Bcl‐2, p53, c‐FLIP, and caspase‐3. In comparison with the NC and blank groups, the TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups showed decreased the expression of TLR4, inhibited proliferation of MCF‐7 and MDA‐MB‐231 cells and promoted MCF‐7 and MDA‐MB‐231 cell apoptosis, and the cells were blocked in G1 phase. In comparison with the NC and blank groups, in the TLR4 siRNA‐1, TLR4 siRNA‐2, and TLR4 siRNA‐3 groups, siRNA‐TLR4 significantly increased expression of p53 and caspase‐3 in MCF‐7 and MDA‐MB‐231 cells, while it decreased the expressions of CDK4, cyclinD1, Livin, Bal‐2, and c‐FLIP. The study demonstrates that TLR4 gene silencing inhibits proliferation and induces apoptosis of MCF‐7 and MDA‐MB‐231 cells. TLR4 gene silencing inhibits proliferation and induces apoptosis of MCF‐7 and MDA‐MB‐231 cells. [ABSTRACT FROM AUTHOR]

We previously reported that both the ubiquitin E3 ligases βTrCP (beta-transducin repeat-containing E3 ubiquitin protein ligase) and Smurf1 (SMAD-specific E3 ubiquitin protein ligase 1) play similar antitumorigenic roles in liver cancer cells. However, whether and how they are reciprocally regulated remains elusive. Here, we show that βTrCP interacts with Smurf1 through the 7 × tryptophan (W) aspartic acid (D)(WD) 40 and the region homologous to the E6-AP carboxyl terminus (HECT) domains, which are the E3 ligase domains of βTrCP and Smurf1, respectively. The E3 ligase domains of βTrCP and Smurf1 are also critical for maintaining the protein expressions of Smurf1 and βTrCP. Moreover, a positive correlation between βTrCP and Smurf1 was also revealed by tissue microarray analysis, indicating that this relationship might be important in liver cancer. Further, we found that Smurf1 increases the protein stability of βTrCP, possibly by reducing autoubiquitination of βTrCP, and vice versa. Interestingly, such effects depended on the presence of E3 ligase domains. Importantly, depletion of Smurf1- or βTrCP-enhanced proliferative capacity of liver cancer cells could be partially reversed by overexpression of wild-type βTrCP or Smurf1 but not their E3 ligase-dead mutants. Collectively, a reciprocal post-translational regulation between βTrCP and Smurf1 has been uncovered in this study. Simultaneous enhancement of βTrCP and Smurf1 functions might be helpful in the treatment of liver cancer. [ABSTRACT FROM AUTHOR]

G-protein-coupled receptor (GPCR) kinase 2 interacting protein-1 (GIT1) is a scaffold protein expressed in various cell types including neurons, endothelial, and vascular smooth muscle cells. The GIT1 knockout (KO) mouse has a pulmonary phenotype due to impaired endothelial function. Because GIT1 is tyrosine phosphorylated by Src kinase, we anticipated that GIT1 KO should have a bone phenotype similar to Src KO. Microcomputed tomography of the long bones revealed that GIT1 KO mice have a 2.3-fold increase in bone mass compared to wild-type controls. Histomorphometry showed increased trabecular number and connectivity suggesting impaired bone remodeling. Immunoblot analysis of GIT1 expression showed that it was expressed in both osteoclasts and osteoblasts. Osteoblast activity and function assayed by alkaline phosphatase, mineral nodule formation, and in vivo calcein labeling were normal in GIT1 KO mice suggesting that the observed increase in bone mass was due to an osteoclast defect. GIT1 KO bone marrow cells differentiated into multinucleated osteoclasts, but had defective bone resorbing function on dentin slices. This defect was likely caused by loss of podosome belt based on immunofluorescence analysis and previous studies showing that GIT1 is required for podosome formation. Furthermore, we found that GIT1 was a regulator of receptor activator of NFκB (RANK) signaling since it was tyrosine phosphorylated in a Src-dependent manner and was required for phospholipase C-γ2 phosphorylation. These data show that GIT1 is a key regulator of bone mass in vivo by regulating osteoclast function and suggest GIT1 as a potential target for osteoporosis therapy. J. Cell. Physiol. 225: 777-785, 2010. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]