Abstract Inducing of dental pulp stem cells (DPSCs) into endothelial cells (ECs) to prevascularize pulp tissue constructs may offer a novel and viable approach for enhancing pulp regeneration. However, there are numerous challenges in current methods for the acquisition of sufficient translational ECs. It was known that Sema4D/PlexinB1 signaling exerts profound effects on enhancing vascular endothelial growth factor (VEGF) secretion and angiogenesis. Whether Sema4D/PlexinB1 could regulate endothelial differentiation of DPSCs is not yet investigated. In this study, when DPSCs were treated with Sema4D (2 μg/mL), ECs‐specific (VEGFR1, VEGFR2, CD31, and vWF), and angiogenic genes and proteins were significantly upregulated. The induced ECs exhibited similar endothelial vessel formation ability to that of human umbilical vein endothelial cells (HUVECs). Furthermore, phosphorylation of AKT increased dramatically within 5 minutes (from 0.93 to 21.8), while p ‐ERK1/2 was moderately elevated (from 0.94 to 2.65). In summary, our results demonstrated that Sema4D/PlexinB1 signaling induces endothelial differentiation of DPSCs. The interactions of Sema4D, VEGF, ANGPTL4, ANG1, and HIF‐1α may play a crucial role in mediating the differentiation process.
To investigate the effect of oxygen glucose deprivation (OGD) on the glutamate release and the role of connexin 43 (Cx43) hemichannels in the OGD-induced glutamate release in primary cultured astrocytes.The astrocytes were randomly divided into four groups: normal control, OGD group, Gap26 (Cx43 hemichannel blocker) plus OGD group, Cx43-specific antisense oligodeoxynucleotide (ASODN) plus OGD group. In the OGD group, the astrocytes were cultured in the oxygen- and glucose-free culture medium (950 mL/L N₂ and 50 mL/L CO₂) for different durations (0, 15, 30, 60, 90, 120 minutes) at 37 Degrees Celsius, while the astrocytes in the control group were cultured in the ordinary culture medium. In the Gap26 plus OGD group or Cx43-ASODN plus OGD group, the astrocytes were incubated with Gap26 or Cx43-ASODN before and during the OGD. The extracelluar glutamate level was measured by high performance liquid chromatography (HPLC).After OGD, the extracelluar glutamte level significantly increased, and reached the maximum (5.00±0.30) nmol/mL at 90 minutes of OGD, which was significantly higher than that of the normal control (2.36±0.15) nmol/mL(P<0.05). After treatment by Cx43-ASODN or Gap26, the increase was inhibited. At 90 minutes of OGD, the extracellular glutamate levels were respectively (4.02±0.18) nmol/mL and (3.93±0.32) nmol/mL. They were signficalty lower than that of the OGD group at the same time (P<0.05).OGD induced glutamate release through Cx43 hemichannel in primary cultured astrocytes.
Abstract The ability of cancer cells to produce large amounts of lactate through aerobic glycosis (Warburg effect) is coupled to high rates of glucose uptake. Enhanced glucose uptake and glycolysis are closely correlated to increased breast tumor aggressiveness and poor prognosis. However, despite the importance of glucose uptake in supplying energy and preventing apoptosis of cancer cells, the majority of current efforts in searching for therapeutic agents targeting glucose metabolism have been aimed at modulating activities of different metabolic enzymes that are involved in glycolysis. Very limited studies have been done in developing novel therapeutic agents against glucose uptake in breast cancer cells. Ataxia-telangiectasia (A-T) is a monogenic, autosomal recessive disorder characterized by cerebellar ataxia and oculocutaneous telangiectasias. The gene mutated in this disease, ATM (A-T, mutated), encodes a 370-kDa protein kinase. Although ATM is traditionally considered to be a nuclear protein that functions as a signal transducer in the cellular response to DNA damage, it is now known that ATM is also present in the cytoplasm and has important cytoplasmic functions. We previously discovered that ATM activates Akt, a main regulator of glucose uptake, by stimulating its phosphorylation at Ser473 following insulin treatment. We also found that ATM participates in insulin-mediated glucose uptake in muscle cells, and KU-55933, a specific inhibitor of ATM, strongly inhibits this process. Recently, we found that KU-55933 inhibits cell proliferation by inducing apoptosis in MDA-MB-231, a triple-negative breast cancer cell line. We have also found that KU-55933 inhibits migration of MDA-MB-231 by a cell invasion assay. Furthermore, we found that these cancer cells exhibit enhanced glucose uptake in response to insulin and the addition of KU-55933 leads to a dramatic reduction of insulin-mediated glucose uptake in these cells. To further test whether KU-55933's ability to induce apoptosis is linked to its inhibition of glucose uptake, we performed a cell death ELISA assay in MDA-MB-231 cells treated with KU-55933 and different concentrations of glucose. Our results show that KU-55933 induces apoptosis of MDA-MB-231 cells, resulting in a similar degree of cell death as glucose starvation, while cells treated with glucose in conjunction with KU-55933 have decreased apoptosis. Moreover, we performed a cell migration assay and found that KU-55933 strongly inhibits the migration of MDA-MB-231 cells (similar to that caused by glucose starvation), which is almost fully rescued by the extra glucose supplemented in the cell culture medium. We have also established a positional isotope labeling-based targeted metabolomics method that can directly measure the conversion from glucose to lactate through glycolysis in cancer cells. Our results show strong production of lactate from glucose in MDA-MB-231 cells even under normal aerobic growth conditions, and KU-55933 strongly inhibits this process. Our findings may lead to the development of KU-55933 and its analogs as a new generation of therapeutic agents against aggressive breast cancer. Citation Format: Yang D-Q, Harris B, Jiang S, Li Y, Freund D, Hegeman A, Cleary M. Inhibition of enhanced glucose uptake and glycolysis by KU-55933 as a novel strategy against aggressive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-05-05.
Abstract Background Prostate cancer (PCa) is the second most common cancer and the fifth leading cause of cancer deaths among men globally. However, the molecular mechanisms leading to the progression have not been fully elucidated. Methods The expression and location of AC245100.4 were examined by RT-qPCR and nuclear-cytoplasmic separation assay. RNA-seq analysis was performed to identify the downstream of AC245100.4. RNA immunoprecipitation was performed to identify the proteins those bind to AC245100.4. Western blotting was performed to quantify the expression of proteins. Finally, a series of gain- or loss-functional assays were done to prove the precise role of AC245100.4 and NR4A3 in PCa. Results We identify a critical lncRNA AC245100.4, which is significantly up-regulated in prostate cancer tissues and cells. Knockdown of AC21500.4 can significantly inhibit prostate cancer progression in vitro and in vivo. Further RNA-seq analysis shows that NR4A3 may be the potential target of AC245100.4. Mechanistically, AC245100.4 de-regulates NR4A3 transcriptionally via increasing p-STAT3, which is a transcriptional repressor of NR4A3. Conclusion Our results demonstrated that AC245100.4 was a critically oncogenic lncRNA in PCa via inhibiting NR4A3 and paved a promising avenue to combat PCa progression by targeting AC245100.4 or NR4A3.
This study compared dentinal and apical crack formation after instrumentation with different nickel-titanium systems at two different working lengths (WL) in large and small canals. Two hundred and eighty human teeth were randomly distributed into two control and 12 experimental groups (n=20 each). Large and small canals were instrumented by the WaveOne, Protaper Universal System (PTU), Twisted File (TF), or Twisted File Adaptive (TFA) at 1 mm shorter than canal length (CL−1 mm) or 1 mm beyond apical foreman (CL+1 mm). Horizontal sections were microscopically observed to evaluate the dentinal cracks (only large canals). Scanning electron microscopy images were taken before and after instrumentation to assess apical cracks. All file types caused more apical cracks in small canals than in large canals regardless of the WL. During over-instrumentation (WL=CL+1 mm), the WaveOne and PTU groups developed significantly more dentinal cracks at the 6 and 9 mm sections than the TF and TFA groups.
In recent years, there has been a strong association between transient receptor potential (TRP) channels and the development of various malignancies, drug resistance, and resistance to radiotherapy. Consequently, we have investigated the relationship between transient receptor potential channels and cervical cancer from multiple angles.
Among gynecological malignancies, ovarian cancer has the highest mortality rate and has sparked widespread interest in studying the mechanisms underlying ovarian cancer development. Based on TCGA and GEO databases, we investigated the highly expressed autophagy-related genes that determine patient prognosis using limma differential expression and Kaplan-Meier survival analyses. The biological processes associated with these genes were also predicted using GO/KEGG functional enrichment analysis. CCK-8, cell scratch, and transwell assays were used to investigate the effects of PXN on the proliferation, migration, and invasion abilities of ovarian cancer cells. Transmission electron microscopy was used to observe the autophagosomes. The expression of autophagy proteins and the PI3K/Akt/mTOR and p110β/Vps34/Beclin1 pathway proteins in ovarian cancer cells was detected using western blot; autophagy protein expression was further detected and localized using cellular immunofluorescence. A total of 724 autophagy-related genes were found to be overexpressed in ovarian -cancer tissues, with high expression of PEX3, PXN, and RB1 associated with poor prognosis in patients (p < .05). PXN activates and regulates signaling pathways related to cellular autophagy, ubiquitination, lysosomes, PI3K-Akt, and mTOR. Autophagosomes were observed in all cell groups. The increase in PXN gene expression promoted the proliferation, migration, and invasion of ovarian cancer cells, increased the expression of SQSTM1/p62 protein, decreased LC3II/LC3Ⅰ, inhibited the phosphorylation of Akt and mTOR proteins, and suppressed the expression of PI3K(p110β) and Beclin1 proteins. The decrease in PXN expression also confirmed these changes. Thus, PXN is highly expressed during ovarian cancer and is associated with poor patient prognosis. It may promote ovarian cancer cell proliferation, migration, and invasion by inhibiting cellular autophagy via suppression of the p110β/Vps34/Beclin1 pathway.