MicroRNA-137 Inhibited Hypoxia-Induced Proliferation of Pulmonary Artery Smooth Muscle Cells by Targeting Calpain-2.

The proliferation of pulmonary artery smooth muscle cells (PASMCs) is an important cause of pulmonary vascular remodeling in pulmonary hypertension (PH). It has been reported that miR-137 inhibits the proliferation of tumor cells. However, whether miR-137 is involved in PH remains unclear. In this study, male Sprague-Dawley rats were subjected to 10% O2 for 3 weeks to establish PH, and rat primary PASMCs were treated with hypoxia (3% O2) for 48 h to induce cell proliferation. The effect of miR-137 on PASMC proliferation and calpain-2 expression was assessed by transfecting miR-137 mimic and inhibitor. The effect of calpain-2 on PASMC proliferation was assessed by transfecting calpain-2 siRNA. The present study found for the first time that miR-137 was downregulated in pulmonary arteries of hypoxic PH rats and in hypoxia-treated PASMCs. miR-137 mimic inhibited hypoxia-induced PASMC proliferation and upregulation of calpain-2 expression in PASMCs. Furthermore, miR-137 inhibitor induced the proliferation of PASMCs under normoxia, and knockdown of calpain-2 mRNA by siRNA significantly inhibited hypoxia-induced proliferation of PASMCs. Our study demonstrated that hypoxia-induced downregulation of miR-137 expression promoted the proliferation of PASMCs by targeting calpain-2, thereby potentially resulting in pulmonary vascular remodeling in hypoxic PH.

MEIS1 regulated proliferation and migration of pulmonary artery smooth muscle cells in hypoxia-induced pulmonary hypertension.

AIM: Proliferation and migration of pulmonary artery smooth muscle cells (PASMCs) are regarded as the primary factors resulting in pulmonary arterial remodeling in pulmonary hypertension (PH). Myeloid ecotropic viral integration site 1 (MEIS1) has been positioned as a negative cardiomyocyte cell cycle regulator and regulates proliferation of multiple kinds of cancer cells. Whether MESI1 is involved in the proliferation and migration of PASMCs deserves to be identified. MAIN METHODS: Sprague Dawley rats were exposed to hypoxia condition (10% O2) for 4 weeks to induce PH and primary rat PASMCs were cultured in hypoxia condition (3% O2) for 48 h to induce proliferation and migration. Immunohistochemistry, immunofluorescence, reverse transcription PCR and Western blot analysis were performed to detect the expressions of target mRNAs and proteins. EDU, CCK8 and wound healing assays were conducted to measure the proliferation and migration of PASMCs. KEY FINDINGS: Hypoxia down-regulated the expression of MEIS1 (both mRNA and protein) in pulmonary arteries and PASMCs. Over-expression of MEIS1 inhibited the proliferation and migration of PASMCs afforded by hypoxia. In contrast, knockdown of MEIS1 under normoxia condition like hypoxia induced the proliferation and migration of PASMCs. MEIS1 mediated hypoxia-induced the proliferation and migration of PASMCs via METTL14/MEIS1/p21 signaling. SIGNIFICANCE: The present study revealed that MEIS1 regulated the proliferation and migration of PASMCs during hypoxia-induced PH. Thus, MEIS1 may be a potential target for PH therapy.

Up-regulation of cullin7 promotes proliferation and migration of pulmonary artery smooth muscle cells in hypoxia-induced pulmonary hypertension.

It has well been demonstrated that E3 ubiquitin ligase cullin7 plays important roles in cancer cell growth control via down-regulating p53 expression. The noncanonical function or the pathogenic role of p53 has more recently been implicated in pulmonary vascular remodeling. Therefore, whether cullin7 participates in hypoxia-induced pulmonary vascular remodeling deserves to be elucidated. The present study found that hypoxia up-regulated the expression of cullin7 mRNA and protein in pulmonary arteries and pulmonary artery smooth muscle cells, and knockdown of cullin7 inhibited hypoxia-induced proliferation and migration of pulmonary artery smooth muscle cells and reversed hypoxia-induced inhibition of p53 expression. Notably, administration of proteasome inhibitor MG132 significantly inhibited the expression of cullin7 and up-regulated the expression of p53 in pulmonary arteries concomitantly with improvement of hypoxia-induced pulmonary vascular remodeling. Our study demonstrated that hypoxia induced up-regulation of cullin7 expression resulting to the proliferation and migration of pulmonary artery smooth muscle cells via down-regulating p53 expression, which contributed to pulmonary vascular remodeling.

AG4, a compound isolated from Radix Ardisiae Gigantifoliae, induces apoptosis in human nasopharyngeal cancer CNE cells through intrinsic and extrinsic apoptosis pathways.

3ß-O-{α-L-Pyran rhamnose-(1→3)-[ß-D-xylopyranose-(1→2)]-ß-D-glucopyranose-(1→4)-[ß-D-lucopyranose-(1→2)]-α-L-pyran arabinose}-cyclamiretin A (AG4) is a saponin component obtained from the Giantleaf Ardisia Rhizome (Rhizoma Ardisiae Gigantifoliae). The present study aimed to investigate the antitumor potential of AG4 and its possible mechanisms in human nasopharyngeal carcinoma cells (CNE). We exposed tumor cells to AG4 to investigate which cell line was the most sensitive to AG4. Cell viability was assessed using the MTT reduction assay, and the effects of AG4 on apoptosis, reactive oxygen species (ROS) content, mitochondrial membrane potential (MMP), and cell cycle were detected using a flow cytometer; the glutathione, superoxide dismutase and malondialdehyde activities were measured using colorimetric methods. The relative expressions of Bax, Bad, Bid, Bcl-2, and Fas mRNA were calculated using the (Equation is included in full-text article.)comparative method by real-time PCR studies and protein was detected by western blotting. AG4 markedly inhibited the growth of CNE cells by decreasing cell proliferation, inducing apoptosis, and blocking the cell cycle in the S phase. The release of caspase-3, caspase-8, and caspase-9 was stimulated by AG4 in CNE, and the decreased proliferation induced by AG4 was blocked by the inhibitor of pan caspase (Z-VAD-FMK). Moreover, the MMP was decreased in AG4-treated cells, and AG4-induced cell apoptosis was accompanied by a rapid and lasting increase in ROS, which was abolished by N-acetyl-L-cysteine (NAC); glutathione, superoxide dismutase, and malondialdehyde were regulated by AG4. AG4 inhibited Bcl-2 mRNA and protein expression and stimulated Bax, Bad, Bid, Fas mRNA, and protein expression in CNE cultures, suggesting an effect at the transcriptional and protein level. In addition, both the FasL inhibitor (AF-016) and the Bcl-2 family inhibitor (GX15-070) could prevent the cell apoptosis induced by AG4. The findings suggested that AG4-induced apoptosis in CNE cells involved a death receptor pathway and a Bcl-2 family-mediated mitochondrial signaling pathway by decreasing the MMPs in an ROS-dependent manner and regulating genes and proteins relative to apoptosis; also, regulation of cell cycles may also play a role in the antitumor mechanism of AG4.

Effects of (20S*,24R*)-epoxy-9,19-cyclolanstane-3ß,12ß,16ß,25-pentaol-3-O-ß-D-xylopyranoside extracted from rhizoma Beesia on immunoregulation and anti-inflammation.

(20S*,24R*)-epoxy-9,19-cyclolanstane-3ß,12ß,16ß,25-pentaol-3-O-ß-D-xylopyranoside (BC1) is a kind of natural bioactive substance extracted from Beesia calthaefolia (Maxim.)Ulbr. This study was designed to evaluate the effects of BC1 on the proliferation of lymphocytes, phagocytosis of peritoneal macrophage, and cytokine secretion, such as tumor necrosis factor (TNF)-α and interleukin (IL)-1ß, and the foot pad thickness index, which is beneficial for understanding the mechanism of BC1 on immunoregulation and anti-inflammation and also will benefit our further research. The proliferation of splenic lymphocyte induced by mitogen (concanavalin A or lipopolysaccharide (LPS)) was detected using the cell counting kit assay. The neutral red phagocytic test of macrophages was determined by colorimetric method. The gene and protein expressions of TNF-α and IL-1ß were measured by real time RT-PCR and ELISA in serum, spleen, and lymphocytes, respectively. In vitro, our present study has shown that BC1 (31.25-250 µg/ml) could inhibit the proliferation of splenic lymphocyte and phagocytosis of macrophages, and inhibit the increased production of TNF-α and IL-1ß in protein and gene levels. In mice, LPS could increase the gene and protein expressions of TNF-α and IL-1ß, respectively, but BC1 (12.5-50 µg/kg) could recover the increased gene and protein expressions of TNF-α and IL-1ß induced by LPS in the spleen and serum of mice. Treatment of arthritic rats with BC1 (1.5 mg/kg body weight) resulted in a significant reduction in foot pad thickness index and serum TNF-α level comparable to the indomethacin-treated arthritic rats, proving its anti-inflammatory effect. Thus, the function of immunoregulation of BC1 may be accomplished through modulating the gene and protein expressions of TNF-α and IL-1ß.

Sanguinarine inhibits vascular endothelial growth factor release by generation of reactive oxygen species in MCF-7 human mammary adenocarcinoma cells.

The inhibitory action and the possible mechanism of anticancer compound Sanguinarine (SAN) on vascular endothelial growth factor (VEGF) in human mammary adenocarcinoma cells MCF-7 were evaluated in this study. We exposed MCF-7 to SAN for 24 h, then cell viability was assessed by using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay. Human VEGF was measured using a paired antibody quantitative ELISA kit, relative expression of VEGF mRNA was calculated using the real-time PCR studies, and the effect of SAN on the reactive oxygen species (ROS) level was detected by the flow cytometer. Treatment with SAN remarkably inhibited growth of MCF-7 cells and induced cell apoptosis. We found that VEGF release was stimulated by subtoxic concentrations of SAN and inhibited by high dose of SAN, SAN-evoked VEGF release was mimicked by low concentration of H2O2, and SAN-regulated VEGF inhibition was accompanied by increasing of ROS; these changes were abolished by antioxidant. High concentration of SAN inhibited VEGF mRNA expression in MCF-7 cultures, suggesting an effect at transcriptional level, and was also abolished by antioxidant. The present findings indicated that the regulation of VEGF expression and release from MCF-7 cells were possibly through reactive oxygen species evoked by SAN.