Expression Of ANGPT2 Research Articles

The Angiopoietin-Tie2 axis contributes to placental vascular disruption and adverse birth outcomes in malaria in pregnancy.

BackgroundMalaria during pregnancy is a major contributor to the global burden of adverse birth outcomes including fetal growth restriction, preterm birth, and fetal loss. Recent evidence supports a role for angiogenic dysregulation and perturbations to placental vascular development in the pathobiology of malaria in pregnancy. The Angiopoietin-Tie2 axis is critical for placental vascularization and remodeling. We hypothesized that disruption of this pathway would contribute to malaria-induced adverse birth outcomes.MethodsUsing samples from a previously conducted prospective cohort study of pregnant women in Malawi, we measured circulating levels of angiopoietin-1 (Angpt-1) and Angpt-2 by Luminex (n=1392). We used a preclinical model of malaria in pregnancy (Plasmodium berghei ANKA [PbA] in pregnant BALB/c mice), genetic disruption of Angpt-1 (Angpt1+/− mice), and micro-CT analysis of placental vasculature to test the hypothesis that disruptions to the Angpt-Tie2 axis by malaria during pregnancy would result in aberrant placental vasculature and adverse birth outcomes.FindingsDecreased circulating levels of Angpt-1 and an increased ratio of Angpt-2/Angpt-1 across pregnancy were associated with malaria in pregnancy. In the preclinical model, PbA infection recapitulated disruptions to the Angiopoietin-Tie2 axis resulting in reduced fetal growth and viability. Malaria decreased placental Angpt-1 and Tie2 expression and acted synergistically with reduced Angpt-1 in heterozygous dams (Angpt1+/−), to worsen birth outcomes by impeding vascular remodeling required for placental function.InterpretationCollectively, these data support a mechanistic role for the Angpt-Tie2 axis in malaria in pregnancy, including a potential protective role for Angpt-1 in mitigating infection-associated adverse birth outcomes.FundingThis work was supported by the Canadian Institutes of Health Research (CIHR), Canada Research Chair, and Toronto General Research Institute Postdoctoral Fellowship Award. The parent trial was supported by the European & Developing Countries Clinical Trials Partnership and the Malaria in Pregnancy Consortium, which was funded by the Bill & Melinda Gates Foundation. The funders had no role in design, analysis, or reporting of these studies.

Orphan nuclear receptors in angiogenesis and follicular development.

Orphan nuclear receptors (ONRs) are a subset of the nuclear receptor family that lacks known endogenous ligands. Among 48 nuclear receptors identified in humans, 25 are classified as ONRs. They function as transcription factors and control the expression of a wide range of genes to regulate metabolism, fertility, immunity, angiogenesis, and many other functions. Angiogenic factors are essential during ovarian follicle development, including follicle growth and ovulation. The correct development of blood vessels contributes to preantral and antral follicular development, selection of the dominant follicle or follicles, follicular atresia, and ovulation. Although progress has been made in understanding the molecular mechanisms that regulate follicular angiogenesis, the role of ONRs as regulators is not clear. Based on their functions in other tissues, the ONRs NR1D1 (REV-ERBβ), NR2C2 (TR4), NR2F2 (COUP-TF-II) and NR3B1, 2, and 3 (ERRα, ERRβ and ERRγ) may modulate angiogenesis during antral follicle development. We hypothesize that this is achieved by effects on the expression and function of VEGFA, ANGPT1, THBS1, and soluble VEGFR1. Further, angiogenesis during ovulation is expected to be influenced by ONRs. NR5A2 (LRH-1), which is required for ovulation, regulates angiogenic genes in the ovary, including VEGFA and the upstream regulator of angiogenesis, PGE2. These angiogenic molecules may also be regulated by NR5A1 (SF-1). Evidence from outside the reproductive tract suggests that NR2F2 and NR4A1(NUR77) promote VEGFC and PGF, respectively, and NR4As (NUR77, NOR1) seem to be necessary for the angiogenic effects of VEGFA and PGE2. Together, the data suggest that ONRs are important regulators of follicular angiogenesis.

Potential of thrombospondin-1 in treatment of polycystic ovary syndrome rat model: a preliminary study

Objective Polycystic ovary syndrome (PCOS) is a common gynecological endocrine disease in reproductive women, and the endocrine levels are also affected by diseases. The aim of this study was to determine the effect of thrombospondin-1 (TSP-1) on PCOS rat model. Methods We established the PCOS rat model, the serum hormones including TSP-1 expression were determined and morphological characteristics were investigated to evaluate the model. These above endocrine and morphological features were investigated again to evaluate the effect of TSP-1 treatment. Results In the PCOS model group, the serum hormones change (higher luteinizing hormone, testosterone and estrogen) and decreased TSP-1 expression levels were found compared with the control group. Besides, the morphological characteristics of PCOS were also observed in the model group. After TSP-1 treatment, the higher TSP-1, ANGPT2, PDGFB and PDGFD expression levels, the lower LH and T levels, decreased vessel density as well as VEGFA and ANGPT1 expression levels were found compared with the control group, and the ovary morphological changes were also observed in the TSP-1 experimental group. Conclusions TSP-1 delivery system might be an alternative therapy for PCOS treatment.

Mapping Angiopoietin1 Expression in the Developing and Adult Brain

Angiopoietin1 (Angpt1) is a secreted protein that activates the endothelial Tie2 receptor. Angpt1 plays a critical role in cardiac development and vascular remodeling in response to disease or injury and shows cell type-restricted expression in the lung, eye, and hematopoietic system. However, the expression of Angpt1 in the developing and adult brain is not known. Here, we employ Angpt1-GFP knock-in reporter mice and a systematic analysis of multiple single-cell RNA sequencing datasets to map the expression of Angpt1 during brain development and adulthood. In the developing brain, Angpt1 displays specific spatiotemporal patterns, with strong expression in cerebellar GABA interneuron progenitors and, to a lower level, in glial progenitor and astrocyte lineages. In the adult brain, on the other hand, we show that neurons are the main source of Angpt1 in the cerebrum, while in the cerebellum, expression is mostly restricted to astrocytes. Together, our data provide clarity on the cell types that express Angpt1 in the developing and adult brain and can be utilized to guide future studies, examining Angpt1 function in brain development, homeostasis, and pathological conditions.

Dual and opposing roles of the androgen receptor in VETC-dependent and invasion-dependent metastasis of hepatocellular carcinoma

Contradictory roles of the androgen receptor (AR) in hepatocellular carcinoma (HCC) metastasis have been reported. We have shown that VETC (vessels encapsulating tumor clusters) mediates invasion-independent metastasis, whereas VETC- HCCs metastasize in an invasion-dependent manner. Herein, we aimed to reveal the roles of AR in HCC metastasis. Mouse xenograft models, clinical samples, and cell models were used. AR expression was significantly lower in HCCs with a VETC pattern, portal vein tumor thrombus, endothelium-coated microemboli or high recurrence rates. Overexpressing AR in VETC+ hepatoma cells suppressed VETC formation and intrahepatic metastasis but promoted pulmonary metastasis of mouse xenografts. AR decreased the transcription of Angiopoietin-2 (Angpt2), a factor essential for VETC formation, by binding to the Angpt2 promoter. The roles of AR in inhibiting VETC formation and intrahepatic metastasis were attenuated by restoring Angpt2 expression, suggesting that AR may repress VETC-dependent intrahepatic metastasis by inhibiting Angpt2 expression and VETC formation. On the other hand, AR upregulated Rac1 expression, promoted lamellipodia formation and increased cell migration/invasion. A Rac1 inhibitor abrogated the AR-mediated promotion of migration/invasion and pulmonary metastasis of VETC+ hepatoma cells, but did not affect the AR-mediated inhibition of intrahepatic metastasis. Furthermore, an AR inhibitor decreased Rac1 expression and attenuated both intrahepatic and pulmonary metastasis of VETC- xenografts, an effect which was abrogated by restoring Rac1 expression. These data indicate that AR may facilitate the lung metastasis of VETC+ HCCs and both the liver/lung metastases of VETC- HCCs by upregulating Rac1 expression and then promoting migration/invasion. AR plays dual and opposing roles in VETC-dependent and invasion-dependent metastasis, which highlights the complex functions of AR and the importance of individualized cancer therapy. In this study, we uncovered the dual and opposing roles of the androgen receptor in VETC (vessels encapsulating tumor clusters)-dependent and invasion-dependent metastasis of hepatocellular carcinoma (HCC). We elucidated the underlying mechanisms of these processes, which provided novel insights into the complex regulatory network of the androgen receptor in HCC metastasis and may have important implications for precision medicine.

Activated mesangial cells induce glomerular endothelial cells proliferation in rat anti-Thy-1 nephritis through VEGFA/VEGFR2 and Angpt2/Tie2 pathway.

ObjectivesWe aimed to investigate the underlying mechanism of endothelial cells (ECs) proliferation in anti‐Thy‐1 nephritis.Materials and methodsWe established anti‐Thy‐1 nephritis and co‐culture system to explore the underlying mechanism of ECs proliferation in vivo and in vitro. EdU assay kit was used for measuring cell proliferation. Immunohistochemical staining and immunofluorescence staining were used to detect protein expression. ELISA was used to measure the concentration of protein in serum and medium. RT‐qPCR and Western blot were used to qualify the mRNA and protein expression. siRNA was used to knock down specific protein expression.ResultsIn anti‐Thy‐1 nephritis, ECs proliferation was associated with mesangial cells (MCs)‐derived vascular endothelial growth factor A (VEGFA) and ECs‐derived angiopoietin2 (Angpt2). In vitro co‐culture system activated MCs‐expressed VEGFA to promote vascular endothelial growth factor receptor2 (VEGFR2) activation, Angpt2 expression and ECs proliferation, but inhibit TEK tyrosine kinase (Tie2) phosphorylation. MCs‐derived VEGFA stimulated Angpt2 expression in ECs, which inhibited Tie2 phosphorylation and promoted ECs proliferation. And decline of Tie2 phosphorylation induced ECs proliferation. In anti‐Thy‐1 nephritis, promoting Tie2 phosphorylation could alleviate ECs proliferation.ConclusionsOur study showed that activated MCs promoted ECs proliferation through VEGFA/VEGFR2 and Angpt2/Tie2 pathway in experimental mesangial proliferative glomerulonephritis (MPGN) and in vitro co‐culture system. And enhancing Tie2 phosphorylation could alleviate ECs proliferation, which will provide a new idea for MPGN treatment.

Decidualization modulates the mesenchymal stromal/stem cell and pericyte characteristics of human decidual stromal cells. Effects on antigen expression, chemotactic activity on monocytes and antitumoral activity

Decidual stromal cells (DSCs) are the most abundant cellular component of human decidua and play a central role in maternal–fetal immune tolerance. Antigen phenotyping and functional studies recently confirmed the relationship of DSCs with mesenchymal stem/stromal cells (MSCs) and pericytes, the latter two cell types being closely related or identical. The present study investigated the effect of decidualization, a process of cell differentiation driven by progesterone (P4) and other pregnancy hormones, on the MSC/pericyte characteristics of DSCs. To this end we isolated undifferentiated DSC (preDSC) lines that were decidualized in vitro (dDSC) by the effect of P4 and cAMP. Using flow cytometry, we found significant downmodulation of the expression of the MSC/pericyte markers α-smooth muscle actin, nestin, CD140b, CD146 and SUSD2 in dDSCs. The dDSCs did not differ, compared to preDSCs, in the expression of angiogenic factors (characteristic of pericytes) HGF, FGF2, ANGPT1 or VEGF according to RT-PCR results, but had significantly increased PGF expression. In migration assays, preDSC-conditioned media had a chemotactic effect on the THP-1 monocytic line (characteristic of pericytes), and this effect was significantly greater in dDSC-conditioned media. Media conditioned with dDSC, but not with preDSC, induced apoptosis in 4 out of 6 different tumor cell lines (characteristic of MSCs) according to propidium iodide staining and flow cytometry results. Our findings show that decidualization induces phenotypic and functional changes in the MSC/pericyte properties of DSCs that may have a role in the normal development of pregnancy.

Dysregulation of circulating miRNAs promotes the pathogenesis of diabetes-induced cardiomyopathy.

Diabetic Cardiomyopathy (DCM) is characterized by myocardial dysfunction caused by diabetes mellitus. After-effects of diabetic cardiomyopathy are far more lethal than non-diabetic cardiomyopathy. More than 300 million people suffer from diabetes and cardiovascular disorder which is expected to be elevated to an alarming figure of 450 million by 2030. Recent studies suggested that miRNA plays important role in the onset of diabetic cardiomyopathy. This study was designed to identify the miRNA that is responsible for the onset of diabetic cardiomyopathy using in silico and in vitro approaches. In this study, to identify the miRNA responsible for the onset of diabetic cardiomyopathy, in silico analysis was done to predict the role of these circulating miRNAs in type 2 diabetic cardiomyopathy. Shared miRNAs that are present in both diseases were selected for further analysis. Total RNA and miRNA were extracted from blood samples taken from type 2 diabetic patients as well as healthy controls to analyze the expression of important genes like AKT, VEGF, IGF, FGF1, ANGPT2 using Real-time PCR. The expression of ANGPT2 was up-regulated and AKT, VEGF, IGF, FGF1 were down-regulated in DCM patients as compared to healthy controls. The miRNA expression of miR-17 was up-regulated and miR-24, miR-150, miR-199a, miR-214, and miR-320a were down-regulated in the DCM patients as compared to healthy controls. This shows that dysregulation of target genes and miRNA may contribute towards the pathogenesis of DCM and more studies should be conducted to elucidate the role of circulating miRNAs to use them as therapeutic and diagnostic options.

Optimization of Spheroid Colony Culture and Cryopreservation of Nucleus Pulposus Cells for the Development of Intervertebral Disc Regenerative Therapeutics

After the discovery of functionally superior Tie2-positive nucleus pulposus (NP) progenitor cells, new methods were needed to enable mass culture and cryopreservation to maintain these cells in an undifferentiated state with high cell yield. We used six types of EZSPHERE® dishes, which support spheroid-forming colony culture, and examined NP cell spheroid-formation ability, number, proliferation, and mRNA expression of ACAN, COL1A2, COL2A1, and ANGPT1. Six different types of cryopreservation solutions were examined for potential use in clinical cryopreservation by comparing the effects of exposure time during cryopreservation on cell viability, Tie2-positivity, and cell proliferation rates. The spheroid formation rate was 45.1% and the cell proliferation rate was 7.75 times using EZSPHERE® dishes. The mRNA levels for COL2A1 and ANGPT1 were also high. In cryopreservation, CryoStor10 (CS10) produced ≥90% cell viability and a high proliferation rate after thawing. CS10 had a high Tie2-positive rate of 12.6% after culturing for 5 days after thawing. These results suggest that EZSPHERE enabled colony formation in cell culture without the use of hydrogel products and that CS10 is the best cryopreservation medium for retaining the NP progenitor cell phenotype and viability. Together, these data provide useful information of NP cell-based therapeutics to the clinic.

Effects of diet, BMP-2 treatment, and femoral skeletal injury on endothelial cells derived from the ipsilateral and contralateral limbs.

Type 2 diabetes (T2D) results in physiological and structural changes in bone, contributing to poor fracture healing. T2D compromises microvascular performance, which can negatively impact bone regeneration as angiogenesis is required for new bone formation. We examined the effects of bone morphogenetic protein-2 (BMP-2) administered locally at the time of femoral segmental bone defect (SBD) surgery, and its angiogenic impacts on endothelial cells (ECs) isolated from the ipsilateral or contralateral tibia in T2D mice. Male C57BL/6 mice were fed either a low-fat diet (LFD) or high-fat diet (HFD) starting at 8 weeks. After 12 weeks, the T2D phenotype in HFD mice was confirmed via glucose and insulin tolerance testing and echoMRI, and all mice underwent SBD surgery. Mice were treated with BMP-2 (5 µg) or saline at the time of surgery. Three weeks postsurgery, bone marrow ECs were isolated from ipsilateral and contralateral tibias, and proliferation, angiogenic potential, and gene expression of the cells was analyzed. BMP-2 treatment increased EC proliferation by two fold compared with saline in LFD contralateral tibia ECs, but no changes were seen in surgical tibia EC proliferation. BMP-2 treatment enhanced vessel-like structure formation in HFD mice whereas, the opposite was observed in LFD mice. Still, in BMP-2 treated LFD mice, ipsilateral tibia ECs increased expression of CD31, FLT-1, ANGPT1, and ANGPT2. These data suggest that the modulating effects of T2D and BMP-2 on the microenvironment of bone marrow ECs may differentially influence angiogenic properties at the fractured limb versus the contralateral limb.

Effect of electroacupuncture on angiopoietin-1 in spinal cord of rats with neuropathic pain

To observe the effect of electroacupuncture (EA) on the behavior, histomorphology and the expression of angiopoietin-1 (Angpt-1) in rats with spinal nerve injury, so as to explore its mechanism on neuropathic pain. Forty-five male SD rats were randomly divided into sham, model and EA groups (n=15 rats in each group). Spinal nerve ligation (SNL) of the L5 lumbar vertebra was performed to establish a rat model of neuropathic pain. The rats in the EA group were given EA at "Zusanli" (ST36) and "Kunlun" (BL60) of the operation side with continuous wave at a frequency of 2 Hz and an intensity of 1.5 mA once a day, 30 minutes each time for 7 days. The sham group only exposed L5 spinal nerves without ligation. Mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) were observed and recorded before modeling and on days 3,5,7,10,12 and 14 after modeling. L4-L6 segments of spinal cord were taken and the morphological changes of spinal dorsal horn were observed by HE staining. The changes of spinal dorsal horn nerve fiber structure were observed by silver plating staining. Angpt-1 expression was detected by Western blot and immunohistochemistry. Compared with the sham group, the model group had significant reductions in MWT and TWL at each time point (P<0.01); compared with the model group, the EA group had significant increases in MWT and TWL on days 10,12 and 14 after intervention (P<0.05, P<0.01). HE staining showed that in the model group, the spinal dorsal horn showed degeneration and necrosis of neurons, nuclear fixation and shrinkage, and loose surrounding tissues. The degree of tissue damage of the EA group was milder than that of the model group. The silver staining results showed the model group had obvious neuronal fibrillary tangles, while there were fewer neuronal fibrillary tangles in the EA group. Compared with the sham group, the Angpt-1 expression in the model group was significantly decreased (P<0.01), and compared with the model group, the EA group had a significant increase in the expression of Angpt-1 (P<0.01). EA can promote the recovery of nerve function in SNL rats by up-regulating Angpt-1 expression.

Targeting choroidal vascular dysfunction via inhibition of circRNA-FoxO1 for prevention and management of myopic pathology

Myopia has become a global public health problem due to high prevalence. Although the etiological factors of myopia have been gradually recognized, the underlying mechanism remains largely elusive. Choroidal vascular dysfunction is recognized as a critical vision-threatening complication in myopia. Circular RNAs (circRNAs) are shown as the critical regulators in many biological processes and human diseases. In this study, we investigated the role of circRNAs in choroidal vascular dysfunction in myopia. The level of circFoxO1 was significantly upregulated in myopic choroid. circFoxO1 silencing suppressed choroidal endothelial cell viability, proliferation, migration, and tube formation invitro and alleviated choroidal vascular dysfunction invivo and exvivo. circFoxO1 silencing retarded the progression of myopia as shown by reduced extracellular matrix remodeling and improved refractive error and axial elongation. Mechanistically, circFoxO1 acted as the sponge of miR-145 to sequester and inhibit miR-145 activity, thereby inducing VEGFA or ANGPT2 expression. miR-145 could mimic the effects of circFoxO1 silencing on choroidal endothelial phenotypes. Collectively, intervention of choroidal vascular dysfunction via regulating circFoxO1 level is a potential strategy for the prevention and management of myopia.

The effects of high fat diet, bone healing, and BMP-2 treatment on endothelial cell growth and function.

Angiogenesis is a vital process during the regeneration of bone tissue. The aim of this study was to investigate angiogenesis at the fracture site as well as at distal locations from obesity-induced type 2 diabetic mice that were treated with bone morphogenetic protein-2 (BMP-2, local administration at the time of surgery) to heal a femoral critical sized defect (CSD) or saline as a control. Mice were fed a high fat diet (HFD) to induce a type 2 diabetic-like phenotype while low fat diet (LFD) animals served as controls. Endothelial cells (ECs) were isolated from the lungs (LECs) and bone marrow (BMECs) 3weeks post-surgery, and the fractured femurs were also examined. Our studies demonstrate that local administration of BMP-2 at the fracture site in a CSD model results in complete bone healing within 3weeks for all HFD mice and 66.7% of LFD mice, whereas those treated with saline remain unhealed. At the fracture site, vessel parameters and adipocyte numbers were significantly increased in BMP-2 treated femurs, irrespective of diet. At distal sites, LEC and BMEC proliferation was not altered by diet or BMP-2 treatment. HFD increased the tube formation ability of both LECs and BMECs. Interestingly, BMP-2 treatment at the time of surgery reduced tube formation in LECs and humeri BMECs. However, migration of BMECs from HFD mice treated with BMP-2 was increased compared to BMECs from HFD mice treated with saline. BMP-2 treatment significantly increased the expression of CD31, FLT-1, and ANGPT2 in LECs and BMECs in LFD mice, but reduced the expression of these same genes in HFD mice. To date, this is the first study that depicts the systemic influence of fracture surgery and local BMP-2 treatment on the proliferation and angiogenic potential of ECs derived from the bone marrow and lungs.

High expression of pro-inflammatory cytokine genes IL-1β and IL-1R2 upon TLR4 activation in Takayasu arteritis.

Toll-like receptors (TLR) 4 and its endogenous ligands are highly expressed in aorta. In thepresent study, we haveexplored the effect of TLR-4 activation by pro-inflammatory and angiogenic factors in PBMCs of patients with Takayasu Arteritis (TA). In thescreening cohort, PBMCs of TA (n = 6) and healthy controls (n = 6) were stimulated with LPS and cultured. mRNA expression of 84 genes were quantitated by RT2 Profiler™ PCR Array kit in PBMCs. Validation set of additional PBMCs from TA (n = 7) and healthy controls [HC) (n = 7) were then stimulated with LPS to study expression of selected genes with delta Ct > 0.1 in the screening cohort. Significant gene expressions were correlated with Indian Takayasu arteritis activity scores (ITAS 2010). Increased expression of CCL2 was observed only in unstimulated PBMCs of patients with TA [median relative difference (RD) of 2.37] as compared to HC (RD 1.37, p < 0.03) in validation cohort, while stimulation with TLR4 ligand led to increased mRNA expression of IL-1β (RD 7.9, p < 0.028) and IL-1R2 (RD 0.08 p < 0.013) genes as compared to that ofHC [RD of 5.32for IL-1β and 0.01for IL-1R2, respectively] in validation cohort. TLR4 activation also led to significantly higher expression of HPSE, TIMP1 and low expression of VEGFB, S1PR1, SERPINF1, ANGPLT4, ANGPT2, TIE1 and NOS3 genes in the screening cohort. But expression of VEGFB was not significant in validation cohort. The significant gene expressions, however, did not correlate with ITAS [ITAS2010 and ITAS-A (CRP)]. TLR4 activation leads to increased expression of IL-1β and IL-1R2 genes in PBMCs of patients with TA.

Angiopoietin-2 silence alleviates lipopolysaccharide-induced inflammation, barrier dysfunction and endoplasmic reticulum stress of intestinal epithelial cells by blocking Notch signaling pathway

ABSTRACT Necrotizing enterocolitis, a devastating gastrointestinal disease with high mortality, poses great threats to global health. Therefore, we conducted this study to explore the role of ANGPT2, as well as the potential mechanism, in necrotizing enterocolitis. IEC-6 cells were stimulated with lipopolysaccharide (LPS) to induce necrotizing enterocolitis model in vitro. The expression of ANGPT2 was measured by RT-qPCR. The cell viability was detected using CCK-8. Besides, the expressions of endoplasmic reticulum (ER) stress-related proteins, Notch signaling pathway-related proteins and tight junction proteins were checked by western blot. The apoptosis and inflammatory response were detected by TUNEL and ELISA, respectively. Moreover, with the adoption of TEER, the cell monolayer permeability was detected. The results showed that ANGPT2 expression was greatly increased after LPS induction. In addition, ANGPT2 knockdown significantly decreased the apoptosis, inflammatory response, barrier dysfunction and endoplasmic reticulum stress of LPS-induced IEC-6 cells. What is more, ANGPT2 knockdown could block Notch signaling pathway. Additionally, with the treatment of Jagged-1, the protective effect of ANGPT2 knockdown on LPS-induced intestinal injury was partly abolished. To sum up, silencing ANGPT2 could improve LPS-induced inflammation, barrier dysfunction and ER stress of intestinal epithelial cells via blocking Notch signaling pathway.

All-trans retinoic acid regulating angiopoietins-1 and alleviating extracellular matrix accumulation in interstitial fibrosis rats

All-trans retinoic acid (ATRA) is one of essentially active metabolite of vitamin A, and plays an important role in diverse physiological processes, such as cellular growth and function. Renal interstitial fibrosis (RIF) is a common pathological characteristic of chronic renal disease causing end-stage renal disease currently lacking effective treatment. Low level of Angiopoietins-1 (Angpt-1) is associated with extracellular matrix accumulation and fibrosis diseases. This study was performed to assess the association of ATRA with Angpt-1 in RIF disease. Rats were divided into three groups: group of sham (SHO group), group of unilateral ureteral obstruction group (UUO group), UUO mice administrated daily at the dose of ATRA (ATRA group). Masson-staining was used to detect the histologic lesion. Immunohistochemistry and Western-blot were applied to determine the targeted proteins. RIF score was significantly increased in UUO rats when compared with that of SHO group, and the fibrosis score was notably reduced in ATRA group. Transforming growth factor-β1 (TGF-β1), collagen IV (Col-IV) and fibronectin (FN) expressions in UUO group were significantly up-regulated, whereas Angpt-1 expression was significantly down-regulated compared with the SHO group. ATRA treatment reduced TGF-β1, Col-IV and FN expressions and improved Angpt-1 expression compared with the UUO group. The protein expression of Angpt-1 in kidney tissue of UUO group was negatively correlated with RIF index and protein expressions of Col-IV, FN and TGF-β1. In conclusion, low expression of Angpt-1 was associated with the RIF disease and ATRA treatment can increase the Angpt-1 and alleviate the RIF lesion in UUO rats.

FOXO1 and ANGPT2 relative gene expression in non-ST-segment elevation myocardial infarction among patients with or without type 2 diabetes.

IntroductionIt is well known that chronic hyperglycemia or chronic inflammation leads to both FOXO1 and Ang-2 gene (ANGPT2) expression induction in endothelial cells. ANGPT2 and FOXO1 relative gene expression in peripheral blood cells in diabetes and myocardial ischemia were not researched extensively.AimOur objective was to evaluate ANGPT2 and FOXO1 gene expression in peripheral blood cells in patients with non-ST elevation myocardial infarction (NSTEMI), both with and without type 2 diabetes mellitus (T2DM), and compare them to the results obtained from T2DM and control subjects.Material and methodsThis was a multi-center, prospective study of 138 NSTEMI patients with/without T2DM, T2DM and a control group. FOXO1, ANGPT2, TBP (TATA box binding protein – as a reference gene) gene expression levels in peripheral blood cells were measured in each patient. Electrocardiography and echocardiography with assessment of ejection fraction (EF) were performed. Patients with NSTEMI underwent urgent (< 24 h) coronarography and the SYNTAX score and GRACE 2.0 score were calculated.ResultsThe ANGPT2 gene relative expression in buffy coat in the analyzed samples was very low and detectable only in 11 patients from all groups (8.66% of all patients). The level of FOXO1 gene relative expression was significantly higher in patients with NSTEMI (median relative expression = 1.39) than in non-NSTEMI patients (median = 1.09) (W = 1578, p < 0.05) regardless of the presence of T2DM. The FOXO1 gene relative expression was not correlated with GRACE 2.0 score or SYNTAX score of NSTEMI patients. We did not observe any significant change in FOXO1 gene expression after successful angioplasty.ConclusionsOn the basis of our results we can conclude that analyzing the ANGPT2 gene relative expression in peripheral blood cells has no role in assessment of CAD complexity among patients with and without T2DM. FOXO1 gene relative expression in blood peripheral cells is elevated in patients with NSTEMI regardless of the presence of T2DM. FOXO1 expression does not decrease after successful percutaneous coronary intervention and is not correlated with the severity of CAD in patients with NSTEMI.

MiR145 Regulates the Proliferation and Apoptosis of Rat Vascular Endothelial Cells under Hyperglycemia by Targeting the ANGPT2 Gene and Involving the NFκB Signaling Pathway.

PurposeA majority of diabetes mellitus patients with disturbances of glucose metabolism present with vascular complications. This study aimed to explore regulatory mechanisms of miR145 and its potential target gene ANGPT2 on diabetic vasculopathy under hyperglycemia.MethodsBased on the fact that miR145 is detected in rat aortic endothelial cells (RAECs) under hyperglycemia, RAECs were transfected with miR145 mimics/inhibitor for further confirmation. RAEC proliferation was detected with CCK8 assays, and cell apoptosis and CD34+-cell population with annexinV–PI staining and anti-CD34FITC on flow cytometry, respectively. Then, qPCR and Western blot were applied to detect mRNA and protein expression of ANGPT2 and involved pathway factor NFκB p65. Subsequently, dual luciferase–reporter gene analysis was utilized to verify whether miR145 acted directly upon the 3ʹUTR of ANGPT2 mRNA.ResultsThe ANGPT2 gene was confirmed to be a direct target of miR145. miR145 mimics markedly downregulated the expression of ANGPT2 and NFκB p65, boosted the percentage of the CD34+ phenotype, and promoted proliferation and suppressed apoptosis of RAECs under hyperglycemia.ConclusionmiR145 might regulate the viability of RAECs via targeting ANGPT2 and involving NFκB signaling to exert a protective effect on diabetic vasculature.

MiR-145-5p suppresses the proliferation, migration and invasion of gastric cancer epithelial cells via the ANGPT2/NOD_LIKE_RECEPTOR axis

ObjectiveThis study aimed to investigate the relationship among miR-145-5p, ANGPT2 and the NOD_LIKE_RECEPTOR pathway, thereby revealing the molecular mechanism of these three factors underlying the proliferation, migration and invasion of gastric cancer (GC) epithelial cells.MethodsqRT-PCR was carried out to detect the expression of miR-145-5p and ANGPT2 mRNA. Western blot was performed to test the protein levels of ANGPT2 as well as NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway. The targeting relationship between miR-145-5p and ANGPT2 was verified via a dual-luciferase reporter gene assay. The proliferation, migration and invasion of GC cells were detected through MTT and Transwell assays, respectively.ResultsThe expression of miR-145-5p was significantly down-regulated in GC cells, while that of ANGPT2 was notably up-regulated. MiR-145-5p directly bound with the 3′-UTR of ANGPT2 mRNA, thereby targeting ANGPT2 after transcription. Overexpression of miR-145-5p inhibited the proliferation, migration and invasion of GC cells by suppressing ANGPT2. Moreover, low expression of ANGPT2 affected the protein levels of NOD1, NOD2 and NF-κB in the NOD_LIKE_RECEPTOR pathway, thus weakening the abilities of cell proliferation, migration and invasion.ConclusionsMiR-145-5p plays an important role in GC epithelial cells, and it can affect cell proliferation, migration and invasion of GC cells by targeting ANGPT2 and regulating the NOD_LIKE_RECEPTOR pathway. Overall, our study further elucidates the molecular mechanism underlying the malignant progression of GC.

Molecular Determinants of Thyroid Nodules with Indeterminate Cytology and RAS Mutations.

Background:RAS gene family mutations are the most prevalent in thyroid nodules with indeterminate cytology and are present in a wide spectrum of histological diagnoses. We evaluated differentially expressed genes and signaling pathways across the histological/clinical spectrum of RAS-mutant nodules to determine key molecular determinants associated with a high risk of malignancy. Methods: Sixty-one thyroid nodules with RAS mutations were identified. Based on the histological diagnosis and biological behavior, the nodules were grouped into five categories indicating their degree of malignancy: non-neoplastic appearance, benign neoplasm, indeterminate malignant potential, low-risk cancer, or high-risk cancer. Gene expression profiles of these nodules were determined using the NanoString PanCancer Pathways and IO 360 Panels, and Angiopoietin-2 level was determined by immunohistochemical staining. Results: The analysis of differentially expressed genes using the five categories as supervising parameters unearthed a significant correlation between the degree of malignancy and genes involved in cell cycle and apoptosis (BAX, CCNE2, CDKN2A, CDKN2B, CHEK1, E2F1, GSK3B, NFKB1, and PRKAR2A), PI3K pathway (CCNE2, CSF3, GSKB3, NFKB1, PPP2R2C, and SGK2), and stromal factors (ANGPT2 and DLL4). The expression of Angiopoietin-2 by immunohistochemistry also showed the same trend of increasing expression from non-neoplastic appearance to high-risk cancer (p < 0.0001). Conclusions: The gene expression analysis of RAS-mutant thyroid nodules suggests increasing upregulation of key oncogenic pathways depending on their degree of malignancy and supports the concept of a stepwise progression. The utility of ANGPT2 expression as a potential diagnostic biomarker warrants further evaluation.