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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 73 records · Page 4
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

MEX3A promotes development and progression of breast cancer through regulation of PIK3CA

Breast cancer has been identified as the most common malignant tumors among women and the morbidity of breast cancer is still increasing rapidly. MEX3A possesses important functions in the regulation of mRNAs and may be involved in a variety of human diseases including cancer, whose relationship with breast cancer is still not clear. In this study, MEX3A was identified as a potential promotor in breast cancer, whose expression was strongly higher in breast cancer tissues than normal tissues. The in vitro experiments showed that MEX3A is capable of promoting the development of breast cancer through stimulating cell proliferation, inhibiting cell apoptosis, arresting cell cycle and promoting cell migration. The functions of MEX3A were also verified in vivo. Furthermore, a combination of genechip analysis and Ingenuity pathway analysis (IPA) identified PIK3CA as a potential downstream target of MEX3A, knockdown of which executes similar inhibitory effects on breast cancer and could alleviate MEX3A-induced progression of breast cancer. In conclusion, our study unveiled, as the first time, MEX3A as a tumor promotor for breast cancer, whose function was carried out probably through the regulation of PIK3CA.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Transcription factor FOXC1 positively regulates SFRP1 expression in androgenetic alopecia

Androgenetic alopecia (AGA) is the most common type of hair loss dysfunction. Secreted frizzled related protein 1 (SFRP1) is found to be associated with hair loss, but its role in AGA and the regulation mechanism of its transcription level is unclear. The aim of our study is to explore the expression of SFRP1 in AGA samples and its transcriptional mechanism. Male frontal and occipital scalp hair follicles from AGA patients were collected, and human dermal papilla cells (DPCs) were isolated and cultured. SFRP1 gene was cloned and constructed into recombinant plasmids to perform dual-luciferase reporter assay. Transcription factor binding sites were predicted through the Jaspar website and further confirmed by the chromatin immunoprecipitation (ChIP) assay. Expression of genes in DPCs was determined by immunofluorescence (IF) staining, quantitative real-time PCR (qRT-PCR) and western blotting. Our findings showed that SFRP1 was highly expressed in DPCs of AGA patients. The core promoter region of SFRP1 was from −100 to +50 bp and was found to be positively regulated by forkhead box C1 (FOXC1), a transcription factor related to hair growth, both at mRNA and protein level in DPCs. Our study suggests that FOXC1 plays an important role in regulating SFRP1 transcription, which may provide new insights into the development of therapeutic strategies for the treatment of AGA.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Leptin modulates gene expression in the heart, cardiomyocytes and the adipose tissue thus mitigating LPS-induced damage

Highlights: • LPS enhanced expression of the leptin gene in mouse tissues and cardiomyocytes. • Leptin downregulated pro-inflammatory genes in vivo and in cardiomyocytes after LPS treatment. • Leptin upregulated expression of antioxidant genes in vivo and in cardiomyocytes after LPS treatment. • Leptin reduced ROS levels in cardiomyocytes after LPS treatment. • Leptin acts to counteract LPS-induced damage in the heart and cardiomyocytes by modulating gene expression. • Anti-inflammatory effects of leptin in transgenic aMUPA mice overexpressing leptin surpassed that of wild type mice. Leptin is an adipokine of pleiotropic effects linked to energy metabolism, satiety, the immune response, and cardioprotection. We have recently shown that leptin causally conferred resistance to myocardial infarction-induced damage in transgenic αMUPA mice overexpressing leptin compared to their wild type (WT) ancestral mice FVB/N. Prompted by these findings, we have investigated here if leptin can counteract the inflammatory response triggered after LPS administration in tissues in vivo and in cardiomyocytes in culture. The results have shown that LPS upregulated in vivo and in vitro all genes examined here, both pro-inflammatory and antioxidant, as well as the leptin gene. Pretreating mice with leptin neutralizing antibodies further upregulated the expression of TNFα and IL-1β in the adipose tissue of both mouse types, and in the αMUPA heart. The antibodies also increased the levels of serum markers for cell toxicity in both mouse types. These results indicate that under LPS, leptin actually reduced the levels of these inflammatory-related parameters. In addition, pretreatment with leptin antibodies reduced the levels of HIF-1α and VEGF mRNAs in the heart, indicating that under LPS leptin increased the levels of these mRNAs. In cardiomyocytes, pretreatment with exogenous leptin prior to LPS reduced the expression of both pro-inflammatory genes, enhanced the expression of the antioxidant genes HO-1, SOD2 and HIF-1α, and lowered ROS staining. In addition, results obtained with leptin antibodies and the SMLA leptin antagonist indicated that endogenous and exogenous leptin can inhibit leptin gene expression. Together, these findings have indicated that under LPS, leptin concomitantly downregulated pro-inflammatory genes, upregulated antioxidant genes, and lowered ROS levels. These results suggest that leptin can counteract inflammation in the heart and adipose tissue by modulating gene expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Necrosulfonamide reverses pyroptosis-induced inhibition of proliferation and differentiation of osteoblasts through the NLRP3/caspase-1/GSDMD pathway

The acute inflammatory stimulation occurring after a bone fracture regulates the repair and healing of local bone injury; however, under certain conditions, pyroptosis may occur in osteoblasts, which affects osteoblast proliferation and differentiation, thereby affecting the growth, development and morphological changes of bone tissue. The aim of the present study was to examine the effect of the pyroptosis inhibitor necrosulfonamide (NSA) on the proliferation and differentiation of osteoblasts and elucidate the underlying mechanism. The results revealed that NSA reversed the effects of ATP/lipopolysaccharide (LPS) on cell viability and pyroptosis, and on the mRNA and protein expression of pyroptosis-related genes. It also suppressed the secretion of IL-6, TNF-α and IL-1β and reversed the effects of ATP/LPS on the activity of ALP and the mRNA expression of differentiation-related genes in osteoblasts. The fact that overexpression of caspase-1, gasdermin D (GSDMD) and NLRP3 abolished the effects of NSA on the viability and pyroptosis of osteoblasts, as well as the mRNA expression of differentiation-related genes and the activity of ALP in osteoblasts, indicated that NSA promoted the proliferation and differentiation of osteoblasts by inhibiting the NLRP3/caspase-1/GSDMD pyroptosis pathway. The present study provides proof supporting the potential application of NSA for improving the function of osteoblasts in fracture repair and indicates the value of the NLRP3/caspase-1/GSDMD pyroptosis pathway as a pharmaceutical target.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

CD47 blockade enhances therapeutic efficacy of cisplatin against lung carcinoma in a murine model

Cisplatin (CDDP) is the first generation of platinum-based drug and is widely used to treat many cancers due to its potency. The present study aims to explore the effects of CDDP on lung carcinoma and its relationship with macrophage phagocytosis. In in vitro study, murine and human lung cancer cell lines were applied and treated with CDDP, CD47 antibody (aCD47), or CDDP plus aCD47. In in vivo study, a tumor xenograft animal model was treated with CDDP, aCD47, or CDDP plus aCD47. Real-time PCR was applied to determine the mRNA expressions. Enzyme-linked immunosorbent assay (ELISA), Western blotting, and Immunofluorescent staining were applied to determine the protein expressions. Flow cytometry was applied to analyze cell apoptosis, phagocytosis, and specific cell populations. CDDP enhanced the expressions of CD47 in lung cancer cells. Interestingly, the blockage of CD47 enhanced the macrophages' phagocytic activity on the CDDP-treated tumor cells. The treatment of CDDP and aCD47 exhibited anti-tumor effects and prolonged the LLC tumor-bearing mice survival time. Mechanistic studies revealed that the treatment of CDDP and aCD47 regulated the phagocytic activity of macrophage, percentage of CD8{sup +} T cells, and cytokines (tumor growth factor (TGF)-β, interleukin (IL)12p70, and interferon (IFN)-γ) in the tumor-bearing model. CD47 blockade enhanced therapeutic efficacy of cisplatin against lung carcinoma in vivo and in vitro.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

ANGPTL4 regulates CD163 expression and Kuppfer cell polarization induced cirrhosis via TLR4/NF-κB pathway

Angiopoietin like 4 (ANGPTL4) has been proved to play an important role in lipid and glucose metabolism disorders and related cardiovascular diseases, but its role in the formation of cirrhosis still needs to be further explored. Therefore, the aim of this study was to investigate the role of ANGPTL4 in the development of liver cirrhosis and its mechanism, as well as its effect on Kupffer cell polarization and hepatic stellate cell activation. The ELISA and RT-qPCR assay were used to detect the content of ANGPTL4 in serum and mRNA expression in cells and tissues respectively. The expression of ANGPTL4, Arg1 and Mrc2 in Kupffer cells was measured by Western blot. The percentage of CD163{sup +} and CD206{sup +} cells was measured by flow cytometry. Mice cirrhosis model was established, and the expression of ANGPTL4 was interfered by injecting sh-ANGPTL4 lentiviral vector into caudal vein. The results revealed that ANGPTL4 was significantly up-regulated in liver cirrhosis patients and HBV induced liver injury cell models. Further studies found that interference with ANGPTL4 regulated CD163 and inhibited the polarization and proinflammatory effects of KCsas well as inhibited the activation of hepatic stellate cells (HSCs) and fibrosis. More importantly, Interference with ANGPTL4 inhibits the progression of liver cirrhosis in mice. What's more, TLR4/NF-κB pathway was involved in the molecular mechanism of ANGPTL4 on Kupffer cells and hepatic stellate cells. It is suggested that the mechanism of sh-ANGPTL4 suppressing the polarization of KCs and the activation of hepatic stellate cells (HSCs) is to regulate the TLR4/NF-κB signaling pathways.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

ACBD3 is up-regulated in gastric cancer and promotes cell cycle G1-to-S transition in an AKT-dependent manner

Highlights: • ACBD3 is up-regulated in gastric cancer. • ACBD3 regulates cell-cycle of gastric cancer in an AKT-dependent manner. It has been reported that ACBD3 is closely related to the malignant process of cells, but its role in gastric cancer has not been elucidated. This study aims to investigate the expression and function of ACBD3 in human gastric cancer. The Cancer Genome Atlas (TCGA) database were selected to analyze mRNA levels of ACBD3 in gastric cancer tissues and normal gastric epithelial tissues. qPCR and Western blot were conducted to detect the expression of ACBD3 in two normal gastric epithelial cell lines and five gastric cancer cell lines which were cultured in our laboratory. To exclude differences in individual background between different patients, we further detected the expression of ACBD3 in 8 pairs of malignant/non-malignant clinical gastric tissues. Through the establishment of stable cells, in vitro cell experiments and in vivo xenotransplantation models in mice, the role of ACBD3 in the proliferation of gastric cancer cells has been further explored. AKT inhibitors were used to deeply explore the molecular regulation mechanism of ACBD3. The results showed that the elevated ACBD3 in gastric cancer tissue were positively correlated with the clinical grade and prognosis of gastric cancer. In terms of molecular function, we found that ACBD3 can enhance the production and growth of gastric cancer cells. At the same time, the activation of AKT kinase played an important role in ACBD3's promotion of G1-to-S transition. The experiments generally indicate that ACBD3 is expected to become a potential diagnostic molecule or therapeutic target for gastric cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

PPARα agonist exerts protective effects in podocyte injury via inhibition of the ANGPTL3 pathway

Peroxisome proliferator-activated receptor α (PPARα) activation has been reported to exert protective effects on podocytes, whereas angiopoietin-like 3 (ANGPTL3) has been shown to exert significant pathogenic effects on these cells. This study aimed to investigate the link between the protective effects of PPARα activation and the pathogenic effects of ANGPTL3 in podocytes. Both PPARα and ANGPTL3 were expressed in cultured podocytes. PPARα mRNA and protein levels decreased whereas ANGPTL3 mRNA and protein levels increased in a time-dependent manner in podocytes treated with puromycin aminonucleoside (PAN). Gemfibrozil, a pharmacological agonist of PPARα, increased PPARα levels and activity in podocytes. The drug also decreased ANGPTL3 levels by potentially weakening ANGPTL3 promoter activity in both normal and PAN-treated podocytes. Furthermore, gemfibrozil significantly decreased PAN-induced apoptosis and F-actin rearrangement. Primary podocytes from Angptl3-knockout mice were cultured. There was no significant difference between Angptl3{sup −/−} podocytes treated with or without gemfibrozil in the lamellipodia numbers after PAN treatment. The results suggested that the protective effects of gemfibrozil on podocytes were not exerted following knockout of the Angptl3 gene. This study identified a novel mechanism of the PPARα agonist gemfibrozil that exerts its protective effects by inhibiting PAN-induced apoptosis and cytoskeleton rearrangements through inhibition of ANGPTL3 expression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

MCL1 inhibition enhances the efficacy of docetaxel against airway-derived squamous cell carcinoma cells

Highlights: • Authentic squamous cell carcinoma (SqCC) cell lines of the lung are sparse. • HARA lung SqCC cells depend highly on MCL1 for survival in vitro and in vivo. • MCL1-silenced HARA cells decline in number upon docetaxel (DTX) exposure. • High MCL1 mRNA expression is linked with shorter survival in lung SqCC patients. • MCL1 depletion + DTX is highly effective against Detroit 562 pharyngeal SqCC cells. MCL1 is an anti-apoptotic BCL2 family member that is often overexpressed in various malignant tumors. However, few reports have described the role of MCL1 in squamous cell carcinoma (SqCC) derived from airways including the lung. In this study, we examined whether MCL1 could be a novel druggable target for airway-derived SqCC, for which effective molecular targeted drugs are unavailable. We searched the Kaplan–Meier Plotter database and found that high MCL1 mRNA expression was significantly associated with shorter survival in patients with lower airway (lung) or upper airway (head and neck) derived SqCC. We also explored the Expression Atlas database and learned that authentic lung SqCC cell lines expressing both TP63 and KRT5 mRNA were extremely sparse among the publicly available “lung SqCC cell lines”, with an exception being HARA cells. HARA cells were highly dependent on MCL1 for survival, and MCL1-depleted cells were not able to grow, and even declined in number, upon docetaxel (DTX) exposure in vitro and in vivo. Similar in vitro experimental findings, including those in a 3D culture model, were also obtained using Detroit 562 pharyngeal SqCC cells. These findings suggested that combined treatment with MCL1 silencing plus DTX appears highly effective against airway-derived SqCC.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Interleukin-35 inhibits lipopolysaccharide-induced endothelial cell activation by downregulating inflammation and apoptosis

Inflammation is an essential factor contributing to sepsis-induced endothelial cell (EC) activation. Interleukin-35 (IL-35) is an anti-inflammatory/immunosuppressive cytokine that exerts protective effects on many inflammatory diseases. In this study, we investigated the effects of IL-35 on lipopolysaccharide (LPS)-induced EC activation and the potential underlying mechanism. Human umbilical vein endothelial cells (HUVECs) were incubated with LPS (1 μg/ml) for 24 h and then cocultured with different concentrations (0, 1, 10, or 100 ng/ml) of recombinant human IL-35 (rhIL-35) for 12 h. Flow cytometry analysis revealed that IL-35 inhibited LPS-induced HUVEC apoptosis in a dose-dependent manner. RT-qPCR and Western blot analyses showed significantly higher mRNA and protein levels of the adhesion molecules intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1) and the inflammatory factors IL-6 and IL-8 in the LPS group than in the control group. These changes were alleviated by IL-35 treatment, suggesting that IL-35 protects ECs by downregulating inflammation. Furthermore, IL-35 induced signal transducer and activator of transcription 1 (STAT1) and STAT4 activation and promoted their interaction. Blocking STAT1 or STAT4 expression by fludarabine (STAT1 inhibitor) treatment or siRNA-STAT4-interfering fragment transfection inhibited the protective effect of IL-35 on ECs. Moreover, we observed a similar protective effect of IL-35 treatment on ECs in a mouse sepsis model induced by intraperitoneal LPS injection. This study indicated that IL-35 exerts anti-inflammatory and antiapoptotic effects on LPS-induced EC activation by activating the STAT1 and STAT4 signaling pathways.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

The oncogenic role of meiosis-specific Aurora kinase C in mitotic cells

Highlights: • AURKC is expressed in meiotic cells and some cancers. • AURKC expression increases cell migration and transformation of human mitotic cells. • Deletion of AURKC in U2OS cells decreases cell migration and soft agar growth. • Transcriptome analysis reveals that AURKC alters the extracellular matrix. Aberrant expression of meiosis-specific genes in cancer has recently emerged as a driver of some cancer formation. Aurora kinase C (AURKC) is a member of the Aurora kinase family of proteins known to regulate chromosome segregation during cell divisions. AURKC is normally expressed in meiotic cells; however, elevated levels of AURKC mRNA and protein are frequently measured in cancer cells. To understand the function of AURKC in cancer cells, expression was induced in noncancerous, human retina pigmented epithelial cells. While AURKC expression did not alter cell proliferation over 72 h, it did increase cell migration and anchorage independent growth in soft agar suggesting an oncogenic role in mitotically dividing cells. To evaluate AURKC as a potential therapeutic target, a frameshift mutation in the gene was introduced in U2OS osteosarcoma cells using CRISPR-Cas9 technology resulting in a premature stop codon. Cancer cells lacking AURKC displayed no change in cell proliferation over 72 h but did migrate less and formed fewer colonies in soft agar. Whole transcriptome sequencing analysis uncovered over 400 differentially expressed genes in U2OS cells with and without AURKC. GO analysis revealed alterations in proteinaceous extracellular matrix genes including COL1A1. These data indicate that therapeutics targeting AURKC could decrease cancer cell metastasis and disease progression. Because AURKC is transcriptionally silenced in normal mitotic cells, its disruption could specifically target cancer cells limiting the toxic side effects associated with current therapeutics.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Aberrant FBXW7-mediated ubiquitination and degradation of ZMYND8 enhances tumor progression and stemness in bladder cancer

ZMYND8, an epigenetic regulator, was identified as a common oncogene across various tumors. However, little was reported about the association between ZMYND8 and bladder cancer. Besides, aberrant mechanisms that contribute to abnormal ZMYND8 expressions still remain unclear. In the current study, we first found that ZMYND8 protein levels were significantly elevated in Bca samples versus normal tissues, but not the mRNA levels. We then utilized the Cell Counting Kit-8 (CCK-8) assay, clone formation assay and transwell analysis to confirm that ZMYND8 could remarkably promote the tumor progression in vitro, including growth capacity and migration. Bioinformatic predictive analysis revealed that E3 ubiquitin ligase FBXW7 interacts directly with ZMYND8 and degrades ZMYND8 in a polyubiquitination manner. Low FBXW7 was a hazard factor for promoting and depending on accumulated ZMYND8 proteins to promote Bca progression. Gene set enrichment analysis (GSEA) further indicated that ZMYND8 was notably associated with stemness process, which was well functionally validated. Lastly, ZMYND8 deficiency was observed to inhibit tumor growth of Bca in vivo, revealing a promising translational significance in Bca treatment. In conclusion, our study for the first time provided evidence for a novel mechanism of FBXW7/ZMYND8 axis in Bca, providing therapeutic vulnerability for individualized cancer treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Substrate stiffness modulates endothelial cell function via the YAP-Dll4-Notch1 pathway

Highlights: • Soft stiffness increases Dll4 expression in endothelial cells via YAP suppression. • Soft substrate-induced Dll4-Notch1 signaling is facilitated by VEGF stimulation. • Elevated Dll4-Notch1 signaling contributes to the regulation of VEGFRs expression. • Substrate stiffness modulates gene expression linked to endothelial cell function. Endothelial cells adapt their functions as a consequence of sensing extracellular substrate stiffness; these alterations allow them to maintain their vascular structure and function. Substrate stiffness-mediated yes-associated protein 1 (YAP) activation plays an important role in mechano-transduction and pro-angiogenic phenotype of endothelial cells, and Delta-like ligand 4 (Dll4)-Notch1 signaling is closely related to angiogenesis; however, the impact of substrate stiffness-mediated interrelation of these pathways on endothelial cell functions remains elusive. We confirmed that endothelial cells on softer substrates not only elongate cellular aspects but also attenuate YAP activation compared to cells on stiffer substrates. Endothelial cells on softer substrates also upregulate the vascular endothelial growth factor receptor 1 (VEGFR1) and VEGFR2 mRNA expression that is enhanced by VEGF stimulation. We determined that endothelial cells on softer substrates increased Dll4 expression, but not Notch1 expression, via YAP signaling. Moreover, endothelial cells on soft substrates induced not only VEGFRs upregulation but also suppression of pro-inflammatory interleukin-6 and plasminogen activator inhibitor-1 mRNA expression and the facilitation of anti-coagulant thrombomodulin and pro-coagulant tissue factor mRNA expression. Our results suggest that endothelial cells activate the YAP-Dll4-Notch signaling pathway in response to substrate stiffness and dictate cellular function.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

MiR-125b enhances autophagic flux to improve septic cardiomyopathy via targeting STAT3/HMGB1

We explore the role of miR-125b in septic cardiomyopathy, focusing on miR-125b/STAT3/HMGB1 axis. CLP mouse model and LPS-stimulated primary rat cardiomyocytes (CMs) and H9C2 cell were used as in vivo and in vitro models of septic cardiomyopathy, respectively. qRT-PCR and western blot were performed to measure expression levels of miR-125b, STAT3, HMGB1, and autophagy-related proteins. MTT assay was employed to examine LPS toxicity. Dual luciferase activity assay and CHIP were performed to validate interactions of miR-125b/STAT3 and STAT3/HMGB1 promoter. Immunostaining was used to assess the level of autophagic flux. ROS level was measured by fluorescence assay. Heart functions were examined via intracoronary Doppler ultrasound. miR-125b was diminished while STAT3 and HMGB1 were elevated in the heart tissue following CLP surgery and in LPS-treated H9C2 cells. LPS treatment up-regulated ROS generation and suppressed autophagic flux. Overexpression of miR-125b mimics or knockdown of STAT3 or HMGB1 alleviated LPS-induced hindrance of autophagic flux and ROS production. miR-125b directly targeted STAT3 mRNA and STAT3 bound with HMGB1 promoter. Overexpression of miR-125b mitigated myocardial dysfunction induced by CLP in vivo. Hyperactivation of STAT3/HMGB1 caused by reduced miR-125b contributes to ROS generation and the hindrance of autophagic flux during septic cardiomyopathy, leading to myocardial dysfunction.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Decellularized ECM derived from normal bone involved in the viability and chemo-sensitivity in multiple myeloma cells

Multiple myeloma (MM) is an incurable plasma cell malignancy. The progression of MM is closely related to the bone microenvironment. Bone matrix proteins are remodeled and manipulated to govern cancer growth during the process of MM. However the role of normal bone extracellular matrix in MM is still unclear. In this study the decellularized extracellular matrix derived from normal SD rats’ skulls (N-dECM) was prepared by decellularization technology. The CCK 8 assay and the dead-live cell kit assay were used to determine the viability of MM cells and the sensitivity to bortezomib. The Realtime PCR and Western blot assay were used to assay the mRNA and protein related to MM. Under the treatment of N-dECM, we found that the viability of MM cells was inhibited and the sensitivity of MM cells to bortezomib was increased. Additionally, the expression levels of APRIL and TACI, which participated in the progression of MM, were significantly decreased in MM cells. It suggested that N-dECM might inhibit the development of MM via APRIL-TACI axis, and our study may provide a novel and potential biomaterial for MM therapy.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

G protein nucleolar 3 promotes Non-Hodgkin lymphoma progression by activating the Wnt/β-catenin signaling pathway

G protein nucleolar 3 (GNL3), which acts as an oncoprotein in various carcinomas, is associated with tumor progression; however, little is known regarding GNL3 function in non-Hodgkin lymphoma (NHL). In this study, we first used in silico analysis to determine associations between GNL3 and diffuse large B-cell lymphoma (DLBCL). We then examined the effect of GNL3 on NHL progression, including cell proliferation, apoptosis, and cell cycle progression, and determined its underlying molecular mechanism using in vitro lymphoma cell lines and in vivo mouse xenograft models. We found that GNL3 mRNA levels were markedly higher in DLBCL tissues than in normal tissues, with these higher levels associated with poor prognosis. Additionally, GNL3 overexpression promoted NHL cell proliferation and cell cycle progression and reduced apoptosis in vitro, and enhanced tumorigenesis in an in vivo xenograft model. Moreover, we found that GNL3 upregulated the levels of Wnt/β-catenin signaling pathway-related factors and downstream target genes, whereas the opposite result was observed in GNL3-silenced cells. Furthermore, a rescue experiment using a Wnt/β-catenin inhibitor (XAV939) confirmed that GNL3 promotes NHL progression by activating the Wnt/β-catenin signaling pathway. These findings demonstrated that GNL3 functions as an oncogenic driver in NHL via the Wnt/β-catenin pathway.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2021

Mast1 mediates radiation-induced gastric injury via the P38 MAPK pathway

Radiation-induced gastric injury is a serious adverse effect and reduces the efficacy of radiotherapy treatment. However, the mechanisms underlying radiation-induced stomach injury remain unclear. Here, mouse stomach and gastric epithelial cells were irradiated with different doses of X-ray radiation. The results showed that radiation induced gastric injury in vivo and in vitro. Differentially expressed functional mRNAs in irradiation-induced gastric tissues were screened from the Gene Expression Omnibus (GEO) database. We found that the expression of microtubule-associated serine/threonine kinase 1 (Mast1) was downregulated in mouse gastric tissues and gastric epithelial cells after irradiation. Furthermore, functional assays showed that knockdown of Mast1 inhibited growth and promoted apoptosis in gastric epithelial cells, while overexpression of Mast1 protected gastric epithelial cells from radiation damage. Mechanistically, Mast1 negatively regulated radiation-induced injury in gastric epithelial cells by inhibiting the activation of P38. The apoptosis caused by knockdown of Mast1 in gastric epithelial cells could be partially reversed by the P38 inhibitor SB203580. Moreover, data from several gastric cancer cell lines and online databases revealed that Mast1 was not involved in the development of gastric cancer. Collectively, our findings demonstrated that Mast1 is essential for radiation-induced gastric injury, providing a promising prognostic and therapeutic target.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2023

Crystal structure of a cap-independent translation enhancer RNA

In eukaryotic messenger RNAs, the 5' cap structure binds to the translation initiation factor 4E to facilitate early stages of translation. Although many plant viruses lack the 5' cap structure, some contain cap-independent translation elements (CITEs) in their 3' untranslated region. The PTE (Panicum mosaic virus translation element) class of CITEs contains a G-rich asymmetric bulge and a C-rich helical junction that were proposed to interact via formation of a pseudoknot. SHAPE analysis of PTE homologs reveals a highly reactive guanosine residue within the G-rich region proposed to mediate eukaryotic initiation factor 4E (eIF4E) recognition. Here we have obtained the crystal structure of the PTE from Pea enation mosaic virus 2 (PEMV 2 ) RNA in complex with our structural chaperone, Fab BL3–6. The structure reveals that the G-rich and C-rich regions interact through a complex network of interactions distinct from those expected for a pseudoknot. The motif, which contains a short parallel duplex, provides a structural mechanism for how the guanosine is extruded from the core stack to enable eIF4E recognition. Homologous PTE elements harbor a G-rich bulge and a three-way junction and exhibit covariation at crucial positions, suggesting that the PEMV 2 tertiary architecture is conserved among these homologs.

59 BASIC BIOLOGICAL SCIENCES↗