Acetyl-CoA synthetase 2 induces pyroptosis and inflammation of renal epithelial tubular cells in sepsis-induced acute kidney injury by upregulating the KLF5/NF-κB pathway.

BACKGROUND: Pyroptosis of the renal tubular epithelial cells (RTECs) and interstitial inflammation are central pathological characteristics of acute kidney injury (AKI). Pyroptosis acts as a pro-inflammatory form of programmed cell death and is mainly dependent on activation of the NLRP3 inflammasome. Previous studies revealed that acetyl-CoA synthetase 2 (ACSS2) promotes inflammation during metabolic stress suggesting that ACSS2 might regulate pyroptosis and inflammatory responses of RTECs in AKI. METHODS AND RESULTS: The expression of ACSS2 was found to be significantly increased in the renal epithelial cells of mice with lipopolysaccharide (LPS)-induced AKI. Pharmacological and genetic strategies demonstrated that ACSS2 regulated NLRP3-mediated caspase-1 activation and pyroptosis through the stimulation of the KLF5/NF-κB pathway in RTECs. The deletion of ACSS2 attenuated renal tubular pathological injury and inflammatory cell infiltration in an LPS-induced mouse model, and ACSS2-deficient mice displayed impaired NLRP3 activation-mediated pyroptosis and decreased IL-1ß production in response to the LPS challenge. In HK-2 cells, ACSS2 deficiency suppressed NLRP3-mediated caspase-1 activation and pyroptosis through the downregulation of the KLF5/NF-κB pathway. The KLF5 inhibitor ML264 suppressed NF-κB activity and NLRP3-mediated caspase-1 activation, thus protecting HK-2 cells from LPS-induced pyroptosis. CONCLUSION: Our results suggested that ACSS2 regulates activation of the NLRP3 inflammasome and pyroptosis by inducing the KLF5/NF-κB pathway in RTECs. These results identified ACSS2 as a potential therapeutic target in AKI.

METTL3 is essential for normal progesterone signaling during embryo implantation via m6A-mediated translation control of progesterone receptor.

Embryo implantation, a crucial step in human reproduction, is tightly controlled by estrogen and progesterone (P4) via estrogen receptor alpha and progesterone receptor (PGR), respectively. Here, we report that N6-methyladenosine (m6A), the most abundant mRNA modification in eukaryotes, plays an essential role in embryo implantation through the maintenance of P4 signaling. Conditional deletion of methyltransferase-like 3 (Mettl3), encoding the m6A writer METTL3, in the female reproductive tract using a Cre mouse line with Pgr promoter (Pgr-Cre) resulted in complete implantation failure due to pre-implantation embryo loss and defective uterine receptivity. Moreover, the uterus of Mettl3 null mice failed to respond to artificial decidualization. We further found that Mettl3 deletion was accompanied by a marked decrease in PGR protein expression. Mechanistically, we found that Pgr mRNA is a direct target for METTL3-mediated m6A modification. A luciferase assay revealed that the m6A modification in the 5' untranslated region (5'-UTR) of Pgr mRNA enhances PGR protein translation efficiency in a YTHDF1-dependent manner. Finally, we demonstrated that METTL3 is required for human endometrial stromal cell decidualization in vitro and that the METTL3-PGR axis is conserved between mice and humans. In summary, this study provides evidence that METTL3 is essential for normal P4 signaling during embryo implantation via m6A-mediated translation control of Pgr mRNA.

Angiotensin II type 2 receptor prevents extracellular matrix accumulation in human peritoneal mesothelial cell by ameliorating lipid disorder via LOX-1 suppression.

Evidence suggests that intracellular angiotensin II type 1 receptor (AT1) contributes to peritoneal fibrosis (PF) under high glucose (HG)-based dialysates. It is generally believed that AT2 antagonisticly affects AT1 function. The aim of this study was to explore whether AT2 activation is beneficial for attenuating human peritoneal mesothelial cell (HPMC) injury due to HG. We treated a HPMC line with HG to induce extracellular matrix (ECM) formation. AT2 was increased and blocked using CGP42112A and AT2 siRNA. Lipid deposition was detected, signaling molecules associated with lectin-like oxidized lipoprotein receptor-1 (LOX-1) and ECM proteins were evaluated by real-time PCR and western blot. The results showed that HG led to AT2 inhibition in HPMCs, inhibition of AT2 further aggravated the expression of ECM proteins, including α-smooth muscle actin, fibroblast specific protein-1 and collagen I, while AT2 decreased the expression of ECM proteins, even during HG stimulation. Interestingly, there was a parallel change in lipid accumulation and ECM formation when AT2 was increased or depressed. Moreover, AT2-mediated decreased ECM production was associated with reduced lipid accumulation in HPMCs and depended on the downregulation of LOX-1. Further analysis showed that HG increased oxidized low-density lipoprotein (ox-LDL) deposition in HPMCs concomitant with an enhanced expression of ECM components, whereas blocking LOX-1 reversed ox-LDL deposition even in the presence of HG. This effect was also accompanied by the remission of ECM accumulation. Our results suggested that AT2 prevented ECM formation in HG-stimulated HPMCs by ameliorating lipid via LOX-1 suppression.

Study of differential proteomics in granulosa cells of premature ovarian insufficiency (POI) and the roles and mechanism of RAC1 in granulosa cells.

In the present study, we focused on characterizing the proteome in granulosa cells in patients with biochemical premature ovarian insufficiency (bPOI) in order to identify differential proteins and investigate the fundamental mechanisms of POI. A total of 2688 proteins were identified based on the data-independent acquisition method, and 70 differentially expressed proteins were significant. Bioinformatic analyses, including gene expression pattern analysis, gene ontology enrichment analysis, Kyoto Encyclopedia of Genes and Genomes pathway analysis, and Search Tool for the Retrieval of Interacting Genes/Proteins analysis, revealed discrete modules and the underlying molecular mechanisms in bPOI. Importantly, we observed that Ras-related C3 botulinum toxin substrate 1 (RAC1) was downregulated in the granulosa cells of bPOI. Low expression of RAC1 may affect the development process of POI by affecting the proliferation, apoptosis, and hormone synthesis of granulosa cells. Downregulation of RAC1 expression in the KGN and COV434 cells inhibited cell proliferation, blocked cells in the G1/G0 phase, and promoted apoptosis. Western blot results showed that ß-catenin and cyclin D1 in the KGN and COV434 cells transfected with RAC1-siRNA were downregulated, while P21 and Bax were upregulated. Knocking down RAC1 in the KGN cells or adding the RAC1 enzyme inhibitor to the human luteinized granulosa cells (hLGC) inhibited the synthesis of E2, and the expression of aromatase and follicle-stimulating hormone receptor (FSHR) was reduced.

The Fusaric Acid Derivative qy17 Inhibits Staphylococcus haemolyticus by Disrupting Biofilm Formation and the Stress Response via Altered Gene Expression.

Staphylococcus haemolyticus (S. haemolyticus) is the second most commonly isolated coagulase-negative staphylococcus (CoNS) in patients with hospital-acquired infections. It can produce phenol-soluble modulin (PSM) toxins and form biofilms. Compared with the wealth of information on Staphylococcus aureus and Staphylococcus epidermidis, very little is known about S. haemolyticus. There is an urgent need to find an effective preparation to combat the harm caused by S. haemolyticus infection. Chinese herbs have been utilized to cure inflammation and infectious diseases and have a long history of anticancer function in China. Here, we modified fusaric acid characterized from the metabolites of Gibberella intermedia, an endophyte previously isolated from Polygonum capitatum. This study shows that fusaric acid analogs (qy17 and qy20) have strong antibacterial activity against S. haemolyticus. In addition, crystal violet analyses and scanning electron microscopy observations demonstrated that qy17 inhibited biofilm formation and disrupted mature biofilms of S. haemolyticus in a dose-dependent manner. Additionally, it reduced the number of live bacteria inside the biofilm. Furthermore, the antibiofilm function of qy17 was achieved by downregulating transcription factors (sigB), transpeptidase genes (srtA), and bacterial surface proteins (ebp, fbp) and upregulating biofilm-related genes and the density-sensing system (agrB). To further elucidate the bacteriostatic mechanism, transcriptomic analysis was carried out. The following antibacterial mechanisms were uncovered: (i) the inhibition of heat shock (clpB, groES, groL, grpE, dnaK, dnaJ)-, oxidative stress (aphC)- and biotin response (bioB)-related gene expression, which resulted in S. haemolyticus being unable to compensate for various stress conditions, thereby affecting bacterial growth; and (ii) a reduction in the expression of PSM-beta (PSMß1, PSMß2, PSMß3) toxin- and Clp protease (clpP, clpX)-related genes. These findings could have major implications for the treatment of diseases caused by S. haemolyticus infections. Our research reveals for the first time that fusaric acid derivatives inhibit the expression of biofilm formation-related effector and virulence genes of S. haemolyticus. These findings provide new potential drug candidates for hospital-acquired infections caused by S. haemolyticus.

Connexin 43 affects thoracic ossification of ligamentum flavum by regulating the p38 MAPK-RUNX2 signaling pathway.

This study aimed to investigate the role of connexin 43 (CX43) in thoracic ossification of ligamentum flavum (TOLF) based on the p38 mitogen-activated protein kinase (p38MAPK)-runt-related transcription factor 2 (RUNX2) pathway. Immunohistochemistry was used to detect CX43 expression in TOLF and non-TOLF patients, fibroblasts of TOLF were isolated and induced osteogenic differentiation, and CX43 expression was detected by western blot analysis (WB). In addition, si-CX43 was used to intervene CX43, and SB203580 was used to inhibit the p38MAPK. The expressions of bone differentiation marker protein were detected by WB, and the ossification ability was analyzed by alizarin red staining. The interaction between RUNX2 and CX43 was identified by dual-luciferase reporter assay. Results found that CX43 was highly expressed during TOLF, and si-CX43 could inhibit the expression of alkaline phosphatase (ALP) and osteopontin (OPN), as well as inhibit TOLF and the p38MAPK-RUNX2 pathway. In addition, SB203580 showed a synergistic effect with si-CX43 to further inhibit TOLF and the expression of RUNX2. The dual-luciferase reporter assay confirmed that RUNX2 could bind to the CX43 promoter. In conclusion, CX43 promotes TOLF, which may be mediated by p38MAPK-RUNX2, and RUNX2 binds to the CX43 promoter to form a positive feedback regulatory loop during TOLF.

Activation of the RAS contributes to peritoneal fibrosis via dysregulation of low-density lipoprotein receptor.

Peritoneal dialysis (PD)-related peritoneal fibrosis (PF) is characterized by progressive extracellular matrix (ECM) accumulation in peritoneal mesothelial cells (PMCs) during long-term use of high glucose (HG)-based dialysates. Activation of the renin-angiotensin system (RAS) has been shown to be associated with PF. The aim of this study was to explore the underlying mechanism of the RAS in HG-induced PF. We treated C57BL/6 mice and a human PMC line with HG to induce a PF model and to stimulate ECM accumulation, respectively. RAS activity was blocked using valsartan or angiotensin II (ANGII) type 1 receptor siRNA. The major findings were as follows. First, mice in the HG group exhibited increased collagen deposition and expression of ECM proteins, including α-smooth muscle actin (α-SMA) and collagen type I in the peritoneum. Consistent with the in vivo data, HG upregulated α-SMA expression in human peritoneal mesothelial cells (HPMCs) in a time- and dose-dependent manner. Second, HG stimulation led to RAS activation in HPMCs, and inactivation of RAS decreased the expression of ECM proteins in vivo and in vitro, even during HG stimulation. Finally, RAS-mediated ECM production was associated with lipid accumulation in HPMCs and depended on the dysregulation of the low-density lipoprotein receptor (LDLr) pathway. HG-stimulated HPMCs showed increased coexpression of LDLr and α-SMA, whereas blockade of RAS activity reversed the effect. Furthermore, inhibition of LDLr signaling decreased α-SMA and collagen type I expression in HPMCs when treated with HG and ANG II. In conclusion, increased intracellular RAS activity impaired lipid homeostasis and induced ECM accumulation in HPMCs by disrupting the LDLr pathway, which contributed to PF.

Long non-coding RNA TUG1 and its molecular mechanisms in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) causes anovulatory infertility in women of reproductive age, but etiopathogenesis of PCOS remains undetermined. Taurine up-regulated 1 (TUG1), an evolutionarily conserved long non-coding RNA, performs various biological functions; however, the role of TUG1 in PCOS remains unclear. Herein, TUG1 expression was assayed in granulosa cells (GCs) of 100 patients with PCOS and 100 control participants. Receiver operating characteristic (ROC) curve analysis was conducted to determine the diagnostic value of TUG1 in PCOS. TUG1 expression was also silenced in KGN cells to explore the role of TUG1 in cellular proliferation, apoptosis, cell-cycle progression, autophagy, and steroidogenesis. We found that TUG1 levels were dramatically increased in the PCOS group compared with those of the control group; this increased expression was related to a rising antral follicle count (R = 0.209, P < 0.001 versus control). The ROC curve indicated a significant separation between PCOS group and the control group (AUC: 0.702; 95% CI: 0.630-0.773; P < 0.001). TUG1 showed a predominantly nuclear localization in human GCs. TUG1 knockdown reduced cellular proliferation, and promoted MAPKs pathway-dependent apoptosis and P21-dependent autophagy, but may not affect cell-cycle progression. TUG1 knockdown increased aromatase expression and oestradiol biosynthesis. Our results indicate that increased TUG1 expression in PCOS GCs may contribute to excessive follicular activation and growth, and may disrupt the selection of dominant follicle. Our study shows that TUG1 can be used as a diagnostic biomarker for PCOS.

Valsartan ameliorates high glucose-induced peritoneal fibrosis by blocking mTORC1 signaling.

IMPACT STATEMENT: Our study provided new insight into the mechanism underlying the preservation of the peritoneum by valsartan. The results demonstrated that the mice receiving chronic high glucose (HG) peritoneal dialysis solution infusion showed a typical feature of peritoneal fibrosis (PF), as well as higher expression of α-smooth muscle actin (α-SMA) and collagen I. In vitro, HG increased the protein expression of α-SMA and collagen I in a dose-dependent manner, while valsartan significantly ameliorated these pathological changes. Interestingly, there was a parallel decrease in the activity of mammalian target of rapamycin complex 1 (mTORC1) and the protein expression levels of α-SMA and collagen I upon treatment with valsartan in vivo and in vitro. Moreover, the mTOR agonist MHY1485 reversed the downregulation of α-SMA and collagen I in vitro, even in the presence of valsartan. Altogether, our findings reported for the first time that valsartan exerts a protective effect against HG-induced PF by inhibiting the activity of the mTORC1 pathway.

Expression profiles of circular RNA in granulosa cells from women with biochemical premature ovarian insufficiency.

Aim: To identify the expression profiles and potential functions of circular RNAs (circRNAs) in granulosa cells (GCs) from women with biochemical premature ovarian insufficiency (bPOI). Patients & methods: CircRNAs microarray analysis was performed to GCs from 8 patients with bPOI and 8 control women, followed by qRT-PCR in 15 paired samples. CircRNA-miRNA networks and the prediction of their enriched signaling pathways were conducted by bioinformatics analysis. Results: A total of 133 upregulated and 424 downregulated circRNAs was identified in women with bPOI. We constructed circRNA-miRNA networks and found that the most predominantly enriched signaling pathways were the FoxO signaling pathway and cellular senescence. Conclusion: CircRNAs are differentially expressed in bPOI, which might contribute to the pathogenesis of bPOI.

MiR-29a regulates the proliferation, aromatase expression, and estradiol biosynthesis of human granulosa cells in polycystic ovary syndrome.

Polycystic ovary syndrome (PCOS) is the most common cause of anovulatory infertility in reproductive-aged women; however, its etiology remains poorly understood. This study aimed to reveal the role of miR-29a in PCOS. MiR-29a levels were measured in the granulosa cells (GCs) of forty-seven PCOS patients and forty-seven controls. A receiver operating characteristic (ROC) curve was drawn to evaluate the diagnostic value of miR-29a in non-hyperandrogenism PCOS. MiR-29a was overexpressed in KGN and COV434 cells to examine its roles in proliferation, cell-cycle progression, and steroidogenesis. MiR-29a was significantly down-regulated in PCOS patients, and associated with an increased antral follicle count. The ROC curve showed a major separation between PCOS patients and controls. MiR-29a overexpression in KGN and COV434 cells inhibited cell proliferation, arrested cell-cycle progression, and decreased aromatase expression and estradiol production. These findings suggest that miR-29a is involved in GC proliferation and steroidogenesis, providing insights into PCOS pathogenesis.

Rapamycin inhibits peritoneal fibrosis by modifying lipid homeostasis in the peritoneum.

Peritoneal fibrosis (PF) is characterized by progressive accumulation of extracellular matrix (ECM) components in the peritoneum under high glucose conditions. Rapamycin has previously been shown to inhibit ECM accumulation of peritoneal mesothelial cells (PMCs) and prevent PF. Here we explored the undefined mechanisms by which rapamycin inhibits ECM accumulation of PMCs. We used high-glucose peritoneal dialysis solution (PDS) in a mouse peritoneal dialysis model to induce in vivo PF and in human PMCs in vitro to stimulate ECM accumulation. The mice that received chronic PDS infusions showed typical features of PF, including markedly increased peritoneal thickness, excessive matrix deposition, increased peritoneal permeability, and higher expressions of α-smooth muscle actin and collagen I. Rapamycin significantly ameliorated these pathological changes. There was a parallel decrease in lipid accumulation in the peritoneum of rapamycin-treated mice. Rapamycin significantly inhibited high-glucose PDS-induced ECM accumulation and reduced the lipid droplet in human PMCs in the presence of PDS. The effects of rapamycin on intracellular lipid metabolism correlated with a series of steps in lipid homeostasis; namely, a decrease in low density lipoprotein receptor-mediated lipid influx, which was mediated through the downregulation of sterol regulatory element-binding protein-2 (SREBP-2) and SREBP cleavage-activating protein (SCAP), and an increase in adenosine triphosphate-binding cassette transporter A1-mediated lipid efflux, which was mediated through the upregulation of the liver X receptor α and peroxisome proliferator-activated receptor α. We conclude that rapamycin shows a clear protective effect on high-glucose PDS-induced PF by improving the disruption of intracellular lipid homeostasis.

Activation of the mTORC1 pathway by inflammation contributes to vascular calcification in patients with end-stage renal disease.

BACKGROUND: Chronic inflammation plays an important role in the progression of vascular calcification (VC). This study was designed to explore the effects and underlying mechanisms of inflammation on VC in the radial arteries of patients with end-stage renal disease (ESRD) with arteriovenostomy. METHODS: Forty-eight ESRD patients were divided into control (n = 25) and inflammation groups (n = 23) according to plasma C-reactive protein (CRP) level. Surgically removed tissues from the radial arteries of patients receiving arteriovenostomy were used in this study. Alizarin Red S staining was used to examine calcium deposition. The expression of inflammation markers, bone structure-associated proteins and mammalian target of rapamycin complex1 (mTORC1) pathway-related proteins was assessed by immunohistochemical staining. RESULTS: The expression of tumor necrosis factor-α (TNF-α) and monocyte chemotactic protein-1 (MCP-1) was increased in the radial arteries of the inflammation group. Additionally, Alizarin Red S staining revealed a marked increase in calcium deposition in the inflammation group compared to controls. Further analysis by immunohistochemical staining demonstrated that the deposition was correlated with the increased expression of bone-associated proteins such as bone morphogenetic proteins-2 (BMP-2) and osteocalcin and collagen I, which suggested that inflammation induces osteogenic differentiation in vascular tissues and that osteogenic cells are the main cellular components involved in VC. Interestingly, there was a parallel increase in the expression of phosphorylated mTOR (p-mTOR) and pribosomal protein S6 kinase 1 (p-S6K1) in the inflammation group. Furthermore, mTORC1 pathway-related proteins were significantly associated with the enhanced expression of bone formation biomarkers. CONCLUSIONS: Inflammation contributed to VC in the radial arteries of ESRD patients via the induction of osteogenic differentiation in vessel walls, which could be regulated by the activation of the mTORC1 pathway.

Mammalian Target of Rapamycin Complex 1 Activation Disrupts the Low-Density Lipoprotein Receptor Pathway: A Novel Mechanism for Extracellular Matrix Accumulation in Human Peritoneal Mesothelial Cells.

Peritoneal fibrosis (PF) is characterized by progressive extracellular matrix (ECM) accumulation. Increasing evidence has suggested that ECM synthesis was increased in human peritoneal mesothelial cells (HPMCs) under high-glucose conditions, but the effects of high-glucose peritoneal dialysis solution (PDS) on ECM synthesis have not been fully elucidated. The aim of this study was to explore the potential mechanisms of high-glucose PDS-induced production of ECM in HPMCs. HPMCs were stimulated by high-glucose PDS. The activity of mammalian target of rapamycin complex 1 (mTORC1) was inhibited by rapamycin or regulatory-associated protein of mTOR (raptor) siRNA. Morphological changes in the cells were observed under an inverted microscope. Oil red O, filipin staining and high-performance liquid chromatography were used to examine lipid accumulation. The expression of low-density lipoprotein receptor (LDLr) regulation, the mTORC1 pathway and ECM-associated markers were assessed by real-time polymerase chain reaction and western blot analysis. The results showed that after treatment with PDS, HPMCs showed notable elongation consistent with the morphology of myofibroblasts, and the expression of ECM proteins such as α-smooth muscle actin, fibroblast specific protein-1 and collagen I was increased. In addition, there was a parallel increase in the ECM and lipid accumulation. Moreover, the effect of intracellular lipid deposition was closely correlated with the dysregulation of LDLr, which was mediated through the upregulation of LDLr, sterol regulatory element-binding protein (SREBP) cleavage-activating protein (SCAP), and SREBP-2 and through the enhanced coexpression of the SCAP with the Golgin. Further analysis showed that PDS enhanced the protein phosphorylation of mTOR, eukaryotic initiation factor 4E-binding protein 1, and p70 S6 kinase. Interestingly, blocking mTORC1 activity reversed the dysregulation of LDLr, even in the presence of PDS. These effects were also accompanied by a decrease in the expression of ECM components. Our findings demonstrated that increased mTORC1 activity exacerbated ECM formation in HPMCs by disrupting LDLr regulation, which contributed to lipid disorder-mediated PF.

Upregulation of MiR-126 Delays the Senescence of Human Glomerular Mesangial Cells Induced by High Glucose via Telomere-p53-p21-Rb Signaling Pathway.

Diabetic kidney disease (DKD) is a microvascular complication of type 2 diabetes. The study of DKD mechanisms is the most important target for the prevention of DKD. Renal senescence is one of the important pathogeneses for DKD, but the mechanism of renal and cellular senescence is unclear. Decreased expression of circulating miR-126 is associated with the development of DKD and may be a promising blood-based biomarker for DKD. This study is to probe the effect and mechanism of miR-126 on the aging of human glomerular mesangial cells (HGMCs) induced by high glucose. HGMCs were cultured with Roswell Park Memorial Institute (RPMI-1640) in vitro. The effect of high glucose on morphology of HGMCs was observed 72 h after intervention. The cell cycle was examined by flow cytometry. The telomere length was measured by Southern blotting. The expression levels of p53, p21 and Rb proteins in p53-p21-Rb signaling pathway and p-stat1, p-stat3 in JAK/STAT signaling pathway were detected by Western blotting respectively. The expression of miR-126 was examined by qRT-PCR. MiR-126 mimics was transfected into HGMCs. The effects of miR-126 mimics transfection on cell morphology, cell cycle, telomere length, p53, p21, Rb, p-stat1 and p-stat3 were observed. The results showed that high glucose not only arrested the cell cycle in G1 phase but also shortened the telomere length. High glucose led to high expression of p53, p21, Rb, p-stat1 and p-stat3 and premature senescence of HGMCs by activating the telomere-p53-p21-Rb and JAK/STAT signaling pathways. Moreover, the miR-126 was decreased in HGMCs induced by high glucose. It was suggested that the transfection of miR-126 mimics could inhibit the telomere-p53-p21-Rb and JAK/STAT signaling pathway activity in vitro and delay the senescence of HGMCs. The results may serve as a new strategy for the treatment of DKD.

High expression of TMEM40 is associated with the malignant behavior and tumorigenesis in bladder cancer.

BACKGROUND: Bladder cancer (BCa) is one of the most common cancers in the urinary system among the world. Previous studies suggested that TMEM40 expression level was significantly associated with clinicopathological parameters including histological grade, clinical stage and pT status of bladder cancer. However, the molecular mechanism of TMEM40 in BCa remains poorly understood. METHODS: Real-time quantitative RT-PCR (qRT-PCR) and western blot (WB) were used to examine the expression levels of TMEM40 in BCa tissues, paired non-cancer tissues and cell lines. A series of experiments, including CCK-8, wound healing, flow cytometry, transwell and EdU assays were performed to assess the effects of TMEM40 on cell proliferation, cell cycle and apoptosis, migration and invasion. In addition, tumor growth was evaluated in vivo using a xenogenous subcutaneously implant model. All statistical analyses were executed by using the SPSS 20.0 software. All experimental data from three independent experiments were analyzed by Student's t test and results were expressed as mean ± standard deviation. RESULTS: In this study, we identified the role of TMEM40 in the tumorigenesis of bladder cancer and found that it was upregulated in bladder cancer tissues and cell lines, compared with their normal counterparts. The results demonstrated that effective silence of TMEM40 expression suppressed cell proliferation, blocked G1-to-S cell cycle transition, and inhibited cell migration and invasion in human bladder 5637 and EJ cell lines. Consistently, in vivo data showed that TMEM40 silencing could dramatically decreased tumor growth. Further study revealed that TMEM40 knockdown resulted in accumulation of p53 and p21 protein and decrease of c-MYC and cyclin D1 protein. CONCLUSION: These data suggest that TMEM40 represents a potential oncogene, which exert a crucial role in the proliferation and apoptosis via the p53 signaling pathway in BCa, thus probably serve as a novel candidate biomarker and a potential therapeutic target for patients with BCa.

Hepatoprotective natural triterpenoids.

Liver diseases are one of the leading causes of death in the world. In spite of tremendous advances in modern drug research, effective and safe hepatoprotective agents are still in urgent demand. Natural products are undoubtedly valuable sources for drug leads. A number of natural triterpenoids were reported to possess pronounced hepatoprotective effects, and triterpenoids have become one of the most important classes of natural products for hepatoprotective agents. However, the significance of natural triterpenoids has been underestimated in the hepatoprotective drug discovery, with only very limited triterpenoids being covered in the reviews of hepatoprotective natural products. In this paper, ca 350 natural triterpenoids with reported hepatoprotective effects in ca 120 references between 1975 and 2016 will be reviewed, and the structure-activity relationships of certain types of natural triterpenoids, if available, will be discussed. Patents are not included.

[Tea polyphenols delays human glomerular mesangial cells senescence induced by high glucose via regulating STAT3/miR-126/telomere signaling pathway activation].

The aim of this paper was to explore the effects and possible mechanisms in vitro of tea polyphenols (TP) delaying human glomerular mesangial cells (HGMCs) senescence induced by high glucose (HG). HGMCs were cultured in vitro and divided into the normal group (N, 5.5 mmol·L⁻¹ glucose), the mannitol group(MNT, 5.5 mmol·L⁻¹ glucose plus 24.5 mmol·L⁻¹ mannitol), the high dose of D-glucose group (HG, 30 mmol·L⁻¹ glucose), the low dose of TP group (L-TP, 30 mmol·L⁻¹ glucose plus 5 mg·L⁻¹ TP) and the high dose of TP group (H-TP, 30 mmol·L⁻¹ glucose plus 20 mg·L⁻¹ TP), which were cultured in 5% CO2 at 37 °C, respectively. Firstly, the effects of TP on the cell morphology of HGMCs were observed after 72 h-intervention. Secondly, the cell cycle, the positive rate of senescence-associated-ß-galactosidase (SA-ß-gal) staining and the telomere length were detected, respectively. Finally, the protein expressions of p53, p21 and Rb in the p53-p21-Rb signaling pathway were investigated, respectively. And the expressions of p-STAT3 and miR-126 were examined severally. The results indicated that HG not only arrested the cell cycle in G1 phase but also increased the positive rate of SA-ß-gal staining, and shortened the telomere length. HG led to the protein over-expressions of p53, p21 and Rb and HGMCs senescence by activating the p53-p21-Rb signaling pathway. In addition, L-TP delayed HGMCs senescence by improving the cell cycle G1 arrest, reducing SA-ß-gal staining positive rate and lengthening the telomere length. L-TP reduced the protein over-expressions of p53, P21 and Rb induced by HG and inhibited the telomere-p53-p21-Rb signaling pathway. Moreover, the expression of p-STAT3 was increased and the expression of miR-126 was decreased in HGMCs induced by HG. L-TP reduced the expression of p-STAT3 and increased the expression of miR-126 in HGMCs. In conclusion, HG could induce HGMCs senescence by activating the telomere-p53-p21-Rb signaling pathway in vitro. L-TP could delay HGMCs senescence through regulating STAT3/miR-126 expressions and inhibiting the telomere-p53-p21-Rb signaling pathway activation. These findings could provide the effective interventions in clinic for preventing and treating renal cell senescence in diabetic kidney disease.

Low expression of PinX1 is associated with malignant behavior in basal-like breast cancer.

Human Pinx1 protein, associated with shelterin proteins, is widely revealed as a haploinsufficient tumor suppressor. Growing evidence has manifested the deregulation of PinX1 in distinct cancers. Nonetheless, the loss status of PinX1 and its diagnostic, prognostic and clinicopathological significance in Basal-like breast cancer are still unclear. In the present study, the PinX1 expression levels of breast cancer tissues were investigated by qRT-PCR and immunoblotting assays. Then immunohistochemistry (IHC) was performed to detect PinX1 expression on a tissue microarray. The optimal threshold for PinX1 positivity was determined by receiver operating characteristic (ROC) curve analysis. To clarify the probable role of PinX1 in BLBC, the PinX1 knockout and stably over-expressed MDA-MB-231 cell lines were constructed by the CRISPR-Cas9 system and gene transfection. The association of PinX1 expression with cell proliferation, migration and apoptosis of MDA-MB-231 cells were observed by CCK-8 assay, wound healing assay, transwell assay, flow cytometric analysis and immunoblotting of the cleaved caspase-3 protein level. Our results showed that both PinX1 mRNA and protein expression were downregulated in breast cancer tissues (P<0.05). In IHC analysis, the optimal cut-off parameter for PinX1 positive expression was 62.5% (the AUC was 0.749, P<0.01). PinX1 positivity was 76.9% (10/14) in luminal subtypes, 50% (5/10) in Her2-enriched breast cancer and 27.3% (9/33) in basal-like subtypes. Besides, in 59 invasive ductal breast carcinomas, PinX1 expression was inversely related to histology grade (P<0.05) while it was positively associated with PR status (P<0.05) and ER status (P<0.05). These results indicated that low expression of PinX1 correlated with aggressive clinicopathological significance of breast cancer, especially in the basal-like subtype. Besides, we identified that overexpression of PinX1 inhibited the proliferation rates and migration ability and increased the apoptosis rates of BLBC. Our findings demonstrated that low expression of PinX1 was associated with malignant behaviors in basal-like subtype of breast cancer. PinX1 is likely a feasible biomarker and molecular target of BLBC.

Diosmetin exerts anti-oxidative, anti-inflammatory and anti-apoptotic effects to protect against endotoxin-induced acute hepatic failure in mice.

To investigate the effects and mechanism of diosmetin on acute hepatic failure (AHF), an AHF murine model was established through administration of lipopolysaccharides/D-galactosamine (LPS/D-GalN). In vitro, diosmetin scavenged free radicals. In vivo, diosmetin decreased mortality among mice, blocked the development of histopathological changes and hepatic damage, and suppressed levels of inflammatory mediators and cytokines. In addition, diosmetin prevented the expression of phosphorylated IKK, IκBα, and NF-κB p65 in the NF-κB signaling pathway, and JNK and p38 in the MAPK signaling pathway. Diosmetin also inhibited hepatocyte apoptosis. Thus, diosmetin exerts protective effects against endotoxin-induced acute hepatic failure in mice. The underlying mechanisms are antioxidation, NF-κB signaling inhibition, inflammatory mediator/cytokine attenuation, and hepatocyte apoptosis suppression. Diosmetin is thus a potential drug candidate for use in the treatment of acute hepatic failure.