查看更多>>摘要：Background: Renal fibrosis has become one of the major diseases threatening global public health and harming human life and health. PTEN methylation plays an important role in fibrotic diseases of many organs. However, the relationship between PTEN methylation and renal fibrosis is still elusive. Methods: In the present study, we established a unilateral ureteral obstruction (UUO) mouse model in vivo and a transforming growth factor beta 1 (TGF-beta 1)-stimulated renal tubular epithelial cell (HK-2) model in vitro. The degree of renal interstitial fibrosis was detected by haematoxylin-eosin (HE) staining and Masson's trichrome staining. Western blot (WB), qRT-PCR, immunohistochemistry (IHC) and methylation-specific PCR (MSP) analyses were used to determine the mechanism by which PTEN methylation regulates renal fibrosis. The alpha-SMA fibrosis marker was detected by immunofluorescence (IF). Additionally, the relationship of PTEN and DNMT3a in UUO was determined by ChIP-qRT-PCR. Results: Our results showed that the promoter region of PTEN was methylated in UUO. Compared to the sham group, the expression of PTEN was significantly reduced in the UUO group. However, the demethylation reagent significantly inhibited epithelial-mesenchymal transition (EMT), which showed increased expression of E-cadherin and decreased expression of alpha-SMA and fibronectin. Moreover, treatment of HK-2 cells with 5-aza-dc reversed the activation of the TGF-beta 1-induced PI3K/AKT signalling pathway, which inhibited renal fibrosis. WB analysis demonstrated that TGF-beta 1 inhibited the PTEN protein expression level and DNMT3a knockdown reversed the inhibitory effect of TGF-beta 1 on PTEN expression. Furthermore, ChIP-qRT-PCR showed that DNMT3a interacted with PTEN. Finally, we found that DNMT3a negatively regulated PTEN to activate the PI3K/AKT signalling pathway and aggravate renal fibrosis in vitro and in vivo. Conclusion: In summary, these results indicated that renal fibrosis is related to the downregulation of PTEN. Additionally, DNMT3a negatively regulates PTEN to activate the PI3K/AKT signalling pathway and induce EMT in renal tubular epithelial cells, thereby aggravating renal fibrosis.
查看更多>>摘要：Background: Osteoporosis is a degenerative skeletal disease essentially caused by bone remodeling disorder. EphrinB2-EphB4 signaling play critical regulatory roles in bone remodeling via communication between osteoclasts and osteoblasts. Eldecalcitol (ED-71), a new vitamin D analog, is a high-potential drug for treating osteoporosis; however, its mechanism has yet to be determined. This study aims to investigate whether EphrinB2-EphB4 signal mediates the process of osteoporosis improved by ED-71. Materials and methods: An ovariectomized (OVX) rat model was constructed in vivo. ED-71 at 30 ng/kg was orally administered once daily for 8 weeks. Osteoclast activity and EphrinB2-EphB4 expression were evaluated by hematoxylin and eosin staining, tartrate-resistant acid phosphatase (TRAP) staining, and immunohistochemical staining. The mRNA levels of oxidation stress factors in the bone tissue were tested by reverse transcription polymerase chain reaction (RT-PCR). An H2O2-stimulated model in vitro was established to simulate the status of osteoporosis. Osteoclastogenesis and associated protein were detected by TRAP staining, F-actin ring formation assay, PCR, and Western blot analysis. EprhrinB2 and EphB4 levels were determined by immunofluorescence, PCR, and Western blot analysis. EprhrinB2 small-interfering RNA knocked down the EprhrinB2 in osteoclasts, and an EphB4 antibody blocked EphB4 in osteoblasts. Results: ED-71 prevented bone loss and decreased the number of osteoclasts in vivo relative to the OVX group. In addition, the bone tissue of OVX rat displayed as an increased level of oxidation stress, which could be inhibited by ED-71. In vitro, in the simulation of osteoporosis with H2O2, ED-71 reversed the increase H2O2-induced oxidative stress. ED-71 then inhibited osteoclastogenesis and osteoclast function, accompanied by increased EphrinB2 expression in osteoclasts. Notably, EphrinB2 knockdown reversed the inhibitory effect of ED-71 on osteoclasts. ED-71 also enhanced EphB4 expression in osteoblasts in vivo and in vitro. Further research showed that ED-71 inhibited osteoclastogenesis in co-culture systems, which was weakened by blocking EphB4 in osteoblasts. Conclusions: ED-71 inhibited osteoclastogenesis by enhancing EphrinB2-EphB4 signaling between osteoclasts and osteoblasts, preventing osteoporosis. This theory explains the role of ED-71 in the treatment of osteoporosis.
查看更多>>摘要：Esophageal cancer is commonly seen as either squamous cell carcinoma (ESCC) or adenocarcinoma (EAC), two very different cancers. CCN1 is a matricellular protein that induces apoptosis in EAC cells through upregulation of DR5, a death receptor, while its role in ESCC is unclear. DR6 is another death receptor, which has been re -ported to induce apoptosis, necroptosis, or pyroptosis in various cell systems with or without the engagement of its putative ligand amyloid precursor protein (APP). In this study, we found that CCN1 and DR6 were both highly expressed in ESCC but downregulated in EAC. Overexpression of CCN1 in ESCC cells inhibited cell proliferation through upregulation of APP and its association with p53 without DR6 involvement. Overexpression of APP stopped cell growth, but overexpression of DR6 did not affect cell growth or cell death whatsoever.
查看更多>>摘要：It has become clear that lipid rafts functions as signaling hotspots connecting cell surface receptors to intracellular signaling pathways. However, the exact involvement of lipid rafts in receptor tyrosine kinase signaling is still poorly understood. In this study, we have analyzed platelet-derived growth factor (PDGF) receptor beta (PDGFR-beta) signaling in two different cell lines depleted of cholesterol, and as a consequence, disruption of lipid rafts. Cholesterol depletion of BJ-hTERT fibroblasts using methyl-beta-cyclodextrin (M beta CD) did not affect PDGFR-beta activation as measured by its tyrosine phosphorylation. However, we did observe a small reduction in AKT phosphorylation and a more robust decrease of ERK1/2 activation. In contrast, in the osteosarcoma cell line U2OS, we noticed a deficient receptor activation. Interestingly, in U2OS cells, the ERK1/2 pathway was unaffected, but instead AKT and SRC signaling was reduced. These results suggest that cell type specific wiring of signaling pathways can lead to differential sensitivity to cholesterol depletion. Furthermore, M beta CD treatment had a much more pronounced morphological effect on U2OS compared to BJ-hTERT cells. This is consistent with a previous report claiming that cancer cells are more sensitive to cholesterol depletion than normal cells. Our data supports the possibility that cholesterol lowering drugs may impede tumor growth.
查看更多>>摘要：By improving the previous method of CUT&RUN, we developed D-CUT&RUN (DSP fixed CUT&RUN) for under expressed transcription factor. High-quality data could be obtained for low expressed transcription factors using chemical crosslinkers (DSP) and reducing agent (DTT). We applied our D-CUT&RUN to detection of Bcl11b and Mycn binding sites in mammary epithelial progenitor cells. Pathway enrichment analysis results of Bcl11b target genes showed that Bcl11b was a regulatory factor involved in breast cancer and it could negatively regulate Wnt signaling pathway. Furthermore, the role of Bcl11b in breast cancer was mediated by catabolic process and stress related pathway. Our research suggested that D-CUT&RUN could be used for low abundance transcription factor binding sites detection and Bcl11b could be a target for breast cancer treatment in the future.
查看更多>>摘要：With-no-lysine kinases (WNKs) are a novel family of serine/threonine protein kinases participating in ion homeostasis via the WNK-OSR1/SPAK-NKCC cascade. Recent studies of WNK1 have revealed that its related signaling pathways mediated tumor-induced angiogenesis and carcinogenesis and uncovered novel roles of WNK1 in endothelial cell migration and proliferation, tumor cell proliferation, and metastasis. Herein, we review the functions of WNK1 in cancer metastasis and angiogenesis and propose WNK1 targeting as an anti-cancer strategy.
查看更多>>摘要：Endoplasmic reticulum (ER) stress and mitochondrial dysfunction play a pivotal role in the pathological process of sepsis-induced acute lung injury (ALI). Quercetin has been proved to exert anti-inflammation in ALI. This study aimed to explore the protection mechanism of quercetin against sepsis-induced ALI via suppressing ER stress and mitochondrial dysfunction. Cecal ligation and puncture (CLP) mouse model was established to mimic sepsis, and LPS was used to stimulate murine lung epithelial (MLE-12) cells. We observed that quercetin ameliorated pulmonary pathological lesion and oxidative damage in sepsis-induced mice. In LPS-stimulated MLE-12 cells, quercetin could inhibit the level of ER stress as evidenced by decreased mRNA expression of PDI, CHOP, GRP78, ATF6, PERK, IRE1 alpha and improve mitochondrial function, as presented by increased MMP, SOD level and reduced production of ROS, MDA. Meanwhile, transcriptome analysis revealed that quercetin upregulated SIRT1/AMPK mRNA expression. Furthermore, we used siRNA to knockdown SIRT1 in MLE-12 cells, and we found that SIRT1 knockdown could abrogate the quercetin-elicited antioxidation in vitro. Therefore, quercetin could protect against sepsis-induced ALI by suppressing oxidative stress-mediated ER stress and mitochondrial dysfunction via induction of the SIRT1/AMPK pathways.
Bollen, Shelby E.Wilkinson, DanielHewison, MartinAtherton, Philip J....
8页
查看更多>>摘要：Muscle atrophy and sarcopenia (the term given to the age-related decline in muscle mass and function), influence an individuals risk of falls, frailty, functional decline, and, ultimately, impaired quality of life. Vitamin D deficiency (low serum levels of 25-hydroxyvitamin D (25(OH)D-3)) has been reported to impair muscle strength and increase risk of sarcopenia. The mechanisms that underpin the link between low 25(OH)D-3 and sarcopenia are yet to be fully understood but several lines of evidence have highlighted the importance of both genomic and non-genomic effects of active vitamin D (1,25-dihydroxyvitamin D (1,25(OH)(2)D-3)) and its nuclear vitamin D receptor (VDR), in skeletal muscle functioning. Studies in vitro have demonstrated a key role for the vitamin D/ VDR axis in regulating biological processes central to sarcopenic muscle atrophy, such as proteolysis, mitochondrial function, cellular senescence, and adiposity. The aim of this review is to provide a mechanistic overview of the proposed mechanisms for the vitamin D/VDR axis in sarcopenic muscle atrophy.
De Kay, Joanne T.Carver, JoshuaShevenell, BaileyKosta, Angela M....
10页
查看更多>>摘要：We investigated the cell surface expression of ErbB receptors on left ventricular (LV) epicardial endothelial cells and CD105+ cells obtained from cardiac biopsies of patients undergoing coronary artery bypass grafting surgery (CABG). Endothelial cells and CD105+ non-endothelial cells were freshly isolated from LV epicardial biopsies obtained from 15 subjects with diabetes mellitus (DM) and 8 controls. The expression of ErbB receptors was examined using flow cytometry. We found that diabetes mellitus (DM) and high levels of hemoglobin A1C are associated with reduced expression of ErbB2. To determine if the expression of ErbB2 receptors is regulated by glucose levels, we examined the effect of high Glucose in human microvascular endothelial cells (HMEC-1) and CD105+ non-endothelial cells, using a novel flow cytometric approach to simultaneously determine the total level, cell surface expression, and phosphorylation of ErbB2. Incubation of cells in the presence of 25 mM Dglucose resulted in decreased cell surface but not total levels of ErbB2. The level of ErbB2 at the cell surface is controlled by disintegrin and metalloproteinase domain-containing protein 10 (ADAM10) that is expressed on LV epicardial cells. Inhibition of ADAM10 prevented the high glucose-dependent decrease in the cell surface expression of ErbB2. We suggest that high Glucose depresses ErbB receptor signaling in endothelial cells and cardiac progenitor cells via the promotion of ADAM10-dependent cleavage of ErbB2 at the cell surface, thus contributing to vascular dysfunction and adverse remodeling seen in diabetic patients.
查看更多>>摘要：Background: Cervical cancer belongs to the most common gynecological malignant cancers. EZH2 has been found to be dysregulated in different kinds of tumors and acts as an oncogene to promote cancer development. However, its upstream regulators and downstream targets in cervical cancer remain unclear. PD-L1 is a surface marker of cancer cells, facilitating the immunosuppressive microenvironment for escape from immunity attack. The molecular mechanism of increased PD-L1 expression in cervical cancer is needed to be explored. Methods: The expression levels of USP7, EZH2 and TIMP2 in cervical cancer patients' samples and cell lines were detected by qRT-PCR and histopathology staining. The functions of USP7, EZH2 and TIMP2 were evaluated by MTT, cell migration and invasion assays after knocking down or overexpression of indicated genes. The tumor microenvironment was determined by testing of PD-L1 expression and cytotoxicity when co-cultured with NK-92 cells. Xenograft model was used to test the function of USP7 in vivo. Results: Our data demonstrated that USP7 and EZH2 were upregulated in cervical cancer, while TIMP2 was downregulated. Inhibition of USP7 and EZH2, or overexpression of TIMP2 suppressed proliferation, migration, invasion and immune escape ability of cervical cancer cells. USP7 could increase EZH2 level, which in turn inhibited TIMP2 expression via methylation in its promoter. TIMP2 was able to mediate PD-L1 expression via NF kappa B signaling pathway. Knocking down of USP7 could inhibit tumor development in vivo of cervical cancer. Conclusions: The study discovered the function and mechanism of USP7 and highlighted its oncogenic role in cervical cancer development. Our results indicated that targeting USP7 could be a therapeutic strategy the treatment of cervical cancer.
NSTL
Elsevier