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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 1,387 records · Page 77
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Development of a cosmic ray oriented trigger for the fluorescence telescope on EUSO-SPB2

The Extreme Universe Space Observatory on a Super Pressure Balloon 2 (EUSO-SPB2), in preparation, aims to make the first observations of Ultra-High Energy Cosmic Rays (UHECRs) from near space using optical techniques. EUSO-SPB2 will prototype instrumentation for future satellite-based missions, including the Probe of Extreme Multi-Messenger Astrophysics (POEMMA) and K-EUSO. The payload will consist of two telescopes. The first is a Cherenkov telescope (CT) being developed to quantify the background for future below-the-limb very high energy (E 10 PeV) astrophysical neutrino observations, and the second is a fluorescence telescope (FT) being developed for detection of UHECRs. The FT will consist of a Schmidt telescope, and a 6192 pixel ultraviolet camera with an integration time of 1.05 s. The first step in the data acquisition process for the FT is a hardware level trigger in order to decide which data to record. In order to maximize the number of UHECR induced extensive air showers (EASs) which can be detected, a novel trigger algorithm has been developed based on the intricacies and limitations of the detector. Finally, the expected performance of the trigger has been characterized by simulations and, pending hardware verification, shows that EUSO-SPB2 is well positioned to attempt the first near-space observation of UHECRs via optical techniques.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

Analysis of cardiomyocyte movement in the developing murine heart

The precise assemblage of several types of cardiac precursors controls heart organogenesis. The cardiac precursors show dynamic movement during early development and then form the complicated heart structure. However, cardiomyocyte movements inside the newly organized mammalian heart remain unclear. We previously established the method of ex vivo time-lapse imaging of the murine heart to study cardiomyocyte behavior by using the Fucci (fluorescent ubiquitination-based cell cycle indicator) system, which can effectively label individual G1, S/G2/M, and G1/S-transition phase nuclei in living cardiomyocytes as red, green, and yellow, respectively. Global analysis of gene expression in Fucci green positive ventricular cardiomyocytes confirmed that cell cycle regulatory genes expressed in G1/S, S, G2/M, and M phase transitions were upregulated. Interestingly, pathway analysis revealed that many genes related to the cell cycle were significantly upregulated in the Fucci green positive ventricular cardiomyocytes, while only a small number of genes related to cell motility were upregulated. Time-lapse imaging showed that murine proliferating cardiomyocytes did not exhibit dynamic movement inside the heart, but stayed on site after entering the cell cycle. - Highlights: • We directly visualized cardiomyocyte movement inside the developing murine heart. • Cell cycle related genes were upregulated in the proliferating cardiomyocytes. • Time-lapse imaging revealed that proliferating murine cardiomyocytes stayed in place. • Murine ventricular cardiomyocytes proliferate on site during development.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

Non-absorbable mesoporous silica for the development of protein sequestration therapies

While our understanding of the molecular events leading to disease onset and progression have increased exponentially, our capacity to therapeutically intervene in these events with new chemical diversity has clearly fallen short of that pace. In the quest to readdress this situation, the drug discovery sector is slowly but increasingly exploring sources of alternative chemical matter, such as the ones provided by material science and nanotechnology. While new functional nano-sized materials hold great promise for the future, our lack of understanding of the long term safety implications associated with systemic exposure as well as the unclear regulatory path ahead hamper their present impact in drug development. Paradoxically, the exploitation of novel, functionally active micron-sized, synthetic, non-absorbable chemical matter, for the treatment or prevention of a number of epidemiologically significant conditions remains clearly underexplored. A combination of pre-existing evidence and future potential indicates that micron-sized mesoporous silica materials could be an untapped source of new drug candidates. These are free from both the dreaded high attrition associated with small molecule drug discovery and the uncertainties of nano-size technologies. This, together with the coming of age of synthetic methodologies to control particle size and shape; pore size and geometry; surface chemistry, bioconjugation and formulation, open up exciting possibilities to exploit this novel chemistry-biology therapeutic interface. - Highlights: • The development of functionally active micron-sized particles in medicine is underexplored. • Mesoporous materials offer the advantage of nanostructured particles in the micron size. • Non-absorbable drugs based on such particles for enzyme inhibition are being developed. • Several conditions can be targeted such as obesity, sepsis or celiac disease.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

Rho GTPase protein Cdc42 is critical for postnatal cartilage development

Cdc42, a small Rho GTPase family member, has been shown to regulate multiple cellular functions in vitro, including actin cytoskeletal reorganization, cell migration, proliferation, and gene expression. However, its tissue-specific roles in vivo remain largely unknown, especially in postnatal cartilage development, as cartilage-specific Cdc42 inactivated mice die within a few days after birth. In this study, we investigated the physiological functions of Cdc42 during cartilage development after birth using tamoxifen-induced cartilage-specific inactivated Cdc42 conditional knockout (Cdc42 {sup fl/fl}; Col2-CreERT) mice, which were generated by crossing Cdc42 flox mice (Cdc42 {sup fl/fl}) with tamoxifen-induced type II collagen (Col2) Cre transgenic mice using a Cre/loxP system. The gross morphology of the Cdc42 cKO mice was shorter limbs and body, as well as reduced body weight as compared with the controls. In addition, severe defects were found in growth plate chondrocytes of the long bones, characterized by a shorter proliferating zone (PZ), wider hypertrophic zone (HZ), and loss of columnar organization of proliferating chondrocytes, resulting in delayed endochondral bone formation associated with abnormal bone growth. Our findings demonstrate the importance of Cdc42 for cartilage development during both embryonic and postnatal stages. - Highlights: • Tamoxifen-induced cartilage specific inactivated Cdc42 mutant mice were generated. • Cdc42 mutant mice were shorter limbs and body. • Severe defects were found in growth plate chondrocytes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2016

NSrp70 is significant for embryonic growth and development, being a crucial factor for gastrulation and mesoderm induction

NSrp70 (nuclear speckle-related protein 70), a recently discovered protein and it belongs to the serine/arginine (SR) rich related protein family. NSrp70 is recognized as an important splicing factor comprising RNA recognition motif (RRM) and arginine/serine (RS)-like regions at the N- and C-terminus respectively, along with two coiled coil domains at each terminus. However, other functions of NSrp70 remain unelucidated. In this study, we investigated the role of NSrp70 in Xenopus embryogenesis and found that its maternal expression plays a critical role in embryonic development. Knockdown of NSrp70 resulted in dramatic reduction in the length of developing tadpoles and mild to severe malformation in Xenopus embryos. In addition, knockdown of NSrp70 resulted in an extremely short axis by blocking gastrulation and convergent extension. Further, animal cap assays along with activin A treatment revealed that NSrp70 is an essential factor for dorsal mesoderm induction as knockdown of NSrp70 caused a dramatic down-regulation of dorsal mesoderm specific genes and its loss significantly shortened the elongation region of animal caps. In conclusion, NSrp70 is crucial for early embryonic development, influencing gastrulation and mesoderm induction. - Highlights: • NSrp70 is required for proper length and dorso-anterior structures. • NSrp70 is essential for gastrulation movement during embryogenesis. • NSrp70 is crucial component for dorsal mesoderm induction.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Histone methyltransferase Setdb1 is indispensable for Meckel's cartilage development

The histone methyltransferase Setdb1 represses gene expression by catalyzing lysine 9 of histone H3 trimethylation. Given that the conventional knockout of Setdb1 is embryo-lethal at the implantation stage, its role in craniofacial development is poorly understood. Here, we investigated the role of Setdb1, using conditional knockout mice—in which Setdb1 was deleted in the Meckel's cartilage (Setdb1 CKO)—and the mouse chondrogenic cell line ATDC5—in which Setdb1 was inhibited by siRNA. Deletion of Setdb1 in Meckel's cartilage, the supportive tissue in the embryonic mandible, led to its enlargement, instead of the degeneration that normally occurs. Chondrocytes from the Meckel's cartilage of Setdb1 CKO mice showed increased size. Furthermore, at embryonic days 16.5 and 18.5, part of the perichondrium was disrupted and mineralization was observed in the Meckel's cartilage. Proliferation analysis showed that inhibition of Setdb1 caused increased proliferation in chondrocytes in the Meckel's cartilage as well as in ATDC5 cells. Quantitative RT-PCR showed decreased expression of chondrogenic genes, such as Sox9, Mmp13, Collagen II, and Aggrecan, as a result of Setdb1 inhibition in ATDC5 cells. Along with these phenomenons, SMAD-dependent BMP signaling was significantly increased by the loss of Setdb1 in both the Meckel's cartilage of Setdb1 CKO mice and ATDC5 cells. Therefore, the abnormal development of Meckel's cartilage in Setdb1 CKO mice is partly due to the enhanced SMAD-dependent BMP signaling. Overall, to our knowledge, the present study is the first to show that epigenetic regulation by Setdb1 is indispensable for the embryonic development of Meckel's cartilage. - Highlights: • Deletion of Setdb1 led to enlarged Meckel's cartilage. • Chondrocytes from the Meckel's cartilage of Setdb1 mutant showed increased in size. • Part of the perichondrium was disrupted and mineralization was observed in the Meckel's cartilage of Setdb1 mutant. • Deletion of Setdb1 increases proliferation in vivo and in vitro. • Deletion of Setdb1 enhances SMAD-dependent BMP signaling in vivo and in vitro.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Development of an aptamer-ampicillin conjugate for treating biofilms

Biofilm formation involves the development of extracellular matrix and initially depends on adherence and tropism by flagellar movement. With the widespread development of antibiotic resistance and tolerance of biofilms, there is a growing need for novel anti-infective strategies. No currently approved medications specifically target biofilms. Aptamers are single-stranded nucleic acid molecules that may bind to their targets with high affinity and affect the target functions. We developed a bifunctional conjugate by linking an aptamer targeting bacterial flagella with ampicillin. We investigated its influence on biofilm prevention and dissolution by ultraviolet–visible spectrophotometry, inverted microscopy, and atomic force microscopy. This conjugate had distinctive antibacterial activity. Notably, the conjugate was more active than either component, and thus had a synergistic effect against biofilms.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Loss of PiT-2 results in abnormal bone development and decreased bone mineral density and length in mice

Highlights: • PiT-2 deficiency decreased mineral density in craniofacial and long bones in mice. • Bone length was reduced in long bones in PiT-2 deficient mice. • Trabecular and cortical bone mineral density were decreased in PiT-2 deficient mice. • Static bone morphometric parameters were altered in PiT-2 deficient mice. • PiT-2 deficiency altered craniofacial bone morphology. Normal bone mineralization requires phosphate oversaturation in bone matrix vesicles, as well as normal regulation of phosphate metabolism via the interplay among bone, intestine, and kidney. In turn, derangement of phosphate metabolism greatly affects bone function and structure. The type III sodium-dependent phosphate transporters, PiT-1 and PiT-2, are believed to be important in tissue phosphate metabolism and physiological bone formation, but their requirement and molecular roles in bone remain poorly investigated. In order to decipher the role of PiT-2 in bone, we examined normal bone development, growth, and mineralization in global PiT-2 homozygous knockout mice. PiT-2 deficiency resulted in reduced vertebral column, femur, and tibia length as well as mandibular dimensions. Micro-computed tomography analysis revealed that bone mineral density in the mandible, femur, and tibia were decreased, indicating that maintenance of bone function and structure is impaired in both craniofacial and long bones of PiT-2 deficient mice. Both cortical and trabecular thickness and mineral density were reduced in PiT-2 homozygous knockout mice compared with wild-type mice. These results suggest that PiT-2 is involved in normal bone development and growth and plays roles in cortical and trabecular bone metabolism feasibly by regulating local phosphate transport and mineralization processes in the bone. Further studies that evaluate bone cell-specific loss of PiT-2 are now warranted and may yield insight into complex mechanisms of bone development and growth, leading to identification of new therapeutic options for patients with bone diseases.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Development of a novel cellulase biosensor that detects crystalline cellulose hydrolysis using a transcriptional regulator

Highlights: • A novel biosensor for detecting cellulolytic activity is developed using cellobiose-dependent transcriptional regulator. • CBGESS shows quantitative response to cellobiose with hyper sensitivity and specificity. • Cellulase activity including hydrolysis of crystalline cellulose is measured by CBGESS via intracellular fluorescence. Successful utilization of cellulose as renewable biomass depends on the development of economically feasible technologies, which can aid in enzymatic hydrolysis. In this study, we developed a whole-cell biosensor for detecting cellulolytic activity that relies on the recognition of cellobiose using the transcriptional factor CelR from Thermobifida fusca and transcriptional activation of its downstream gfp reporter gene. The fluorescence intensity of whole-cell biosensor, which was named as cellobiose-detectible genetic enzyme screening system (CBGESS), was directly proportional to the concentration of cellobiose. The strong fluorescence intensity of CBGESS demonstrated the ability to detect cellulolytic activity with two cellulosic substrates, carboxymethyl cellulose and p-nitrophenyl β-D-cellobioside in cellulase-expressing Escherichia coli. In addition, CBGESS easily sensed crystalline cellulolytic activity when commercial Celluclast 1.5L was dropped on an Avicel plate. Therefore, CBGESS is a powerful tool for detecting cellulolytic activity with high sensitivity in the presence of soluble or insoluble cellulosic substrates. CBGESS may be further applied to excavate novel cellulases or microbes from both genetic libraries and various environments.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Distorted antibody repertoire developed in the absence of pre-B cell receptor formation

Highlights: • Leaky B cells in SLC-deficient mice circumvent the pre-BCR checkpoint. • Antibody repertoires differing in VDJ-usage exist in leaky B cells in λ5{sup −}/{sup −} mice. • Leaky B cells do not originate from B1 or particular B2 cells. • The CDR-H3 middle loop in λ5{sup −}/{sup −} bone marrow B cells is enriched in arginines. The pre-B cell receptor (pre-BCR), consisting of the μ heavy chain (μHC) and the surrogate light chain (SLC, Vpre-B and λ5), plays important roles during B cell development. The formation of the pre-BCR, which enables the nascent immunoglobulin HC to associate with the SLC, is considered a prerequisite for B cell development. However, a significant number of peripheral mature (leaky) B cells exist in SLC-deficient mice. These leaky B cells develop in the absence of pre-BCR and do not undergo the pre-BCR checkpoint. The antibody repertoires of leaky B cells thus reflect the absence of pre-BCR function. To investigate how the absence of the pre-BCR is circumvented by these leaky-B cells and examine the effect of the pre-BCR checkpoint on the antibody system, we analyzed the antibody repertoires of λ5-deficient (λ5{sup −/−}) mice using next-generation sequencing. In λ5{sup −/−} mice, spleen B cells displayed different patterns of VDJ-usage, relative to those in wild-type (WT) mice. Moreover, leaky B cells were neither derived from unusual B2 cells, characterized by particular LC gene rearrangements in the absence of pre-BCR signaling, nor from B1 cells, originating from different B cell progenitors. Analysis of the CDR-H3 amino acid sequences of μ-chain repertoires revealed that certain bone marrow B cells with particular CDR-H3 profiles undergo clonal expansion in λ5{sup −/−} mice. Part of these CDR-H3s contain arginine(s) in the middle of the CDR-H3 loop in λ5{sup −/−} mice, whereas few arginine(s) exist in this middle loop in WT CDR-H3s in the absence of clonal expansion. This CDR-H3 feature in λ5{sup −/−} mice presumably reflects the role of the pre-BCR in autoantibody regulation, since arginine(s) are often found in the antigen-binding site of autoantibodies. Here, we present a unique viewpoint on the role of pre-BCR, by assessing the whole antibody repertoire formed in SLC-deficient mice.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

EphA7 regulates claudin6 and pronephros development in Xenopus

Highlights: • EphA7 knockdown perturbs pronephros morphogenesis and differentiation in Xenopus. • Knockdown of EphA7 reduces membrane CLDN6 level in the pronephros tubule cells. • EphA7 phosphorylates and destabilizes membrane CLDN6 in cultured cells. • A soluble form of EphA7 stabilizes CLDN6 and antagonizes EphA7. Eph/ephrin molecules are widely expressed during embryonic development, and function in a variety of developmental processes. Here we studied the roles of the Eph receptor EphA7 and its soluble form in Xenopus pronephros development. EphA7 is specifically expressed in pronephric tubules at tadpole stages and knockdown of EphA7 by a translation blocking morpholino led to defects in tubule cell differentiation and morphogenesis. A soluble form of EphA7 (sEphA7) was also identified. Interestingly, the membrane level of claudin6 (CLDN6), a tetraspan transmembrane tight junction protein, was dramatically reduced in the translation blocking morpholino injected embryos, but not when a splicing morpholino was used, which blocks only the full length EphA7. In cultured cells, EphA7 binds and phosphorylates CLDN6, and reduces its distribution at the cell surface. Our work suggests a role of EphA7 in the regulation of cell adhesion during pronephros development, whereas sEphA7 works as an antagonist.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Tsc1 controls the development and function of alveolar macrophages

Highlights: • Deletion of Tsc1 leads to the impaired development and a great reduction of AMs. • Tsc1 suppresses the proliferation of AMs. • Tsc1-deficient AMs exhibits increased ROS production and phagocytosis. Alveolar macrophages (AMs) are pivotal for maintaining the lung homeostasis, but how the development and function of AMs regulated remains largely unknown. In the present study, we demonstrated that the number of AMs was controlled by the Tsc1 protein. Cd11c-specific deletion of Tsc1 caused inefficient transition from pre-AMs to AMs in lung, which led to a great reduction of AM population. Ablation of Tsc1 downregulated the expression of surface marker CD64 and SiglecF on AMs. We further showed that conditional knockout of Tsc1 led to enhanced proliferation and increased reactive oxygen species (ROS) production and phagocytosis in AMs. These results indicated that Tsc1 was a critical regulator of development, proliferation and function in AMs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

ST6GAL1 negatively regulates monocyte transendothelial migration and atherosclerosis development

Highlights: • ST6GAL1 expression is inversely related to atherosclerosis development. • Knockdown of ST6GAL1 in vascular endothelial cells directly promotes monocyte transendothelial migration. • ST6GAL1 overexpression inhibits TNFα-induced monocyte transendothelial migration. • β-catenin sialylation level is downregulated in inflammatory endothelial cells. Monocyte transendothelial migration is a critical step in the initial stage of atherosclerosis, in which the involvement of α-2,6 sialyltransferase 1 (ST6GAL1) has been confirmed by increasing evidence. But the direct relationship between ST6GAL1 and atherosclerosis remains incompletely uncertain. In this study, we demonstrated that the expression level of ST6GAL1 in vascular endothelium was significantly decreased in atherosclerosis development process, while obviously recovered after atherosclerosis regression. Further analysis showed that knockdown of ST6GAL1 by RNA interference in vascular endothelial cells EA. hy926 obviously promoted TNFα-triggered monocyte-transendothelial migration, whereas overexpression of ST6GAL1 strongly inhibited monocyte-transendothelial migration. Moreover, we firstly found β-catenin is a sialylated protein and its sialylation level is decreased in TNFα-treated EA. hy926 cells, suggesting that the function of ST6GAL1 in preventing both atherosclerosis development and monocyte transendothelial migration might result from the sialylation of β-catenin of endothelium. Our results suggested ST6GAL1 might be a potential target for atherosclerosis prevention and treatment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

A BTB-ZF protein, ZNF131, is required for early B cell development

Highlights: • ZNF131 is required for early B cell development. • Transition from pro-B to pre-B cell stage is blocked in the absence of ZNF131. • Proliferation of pro-B cells is severely impaired in ZNF131-deficinet mice. • DNA rearrangement of immunoglobulin heavy chain genes is partially impaired in ZNF131-deficinet mice. • ZNF131 suppresses some of the p53 target genes, including Cdk inhibitor p21{sup Cip1} and pro-apoptotic factors, Bax and Puma. Members of the BTB-ZF transcription factor family play important roles in lymphocyte development. During T cell development, ZNF131, a BTB-ZF protein, is critical for the double-negative (DN) to double-positive (DP) transition and is also involved in cell proliferation. Here, we report that knockout of Znf131 at the pre-pro-B cell stage in mb1-Cre knock-in mouse resulted in defect of pro-B to pre-B cell transition. ZNF131 was shown to be required for efficient pro-B cell proliferation as well as for immunoglobulin heavy chain gene rearrangement that occurs in the proliferating pro-B cells. We speculate that inefficient gene rearrangement may be due to loss of cell proliferation, since cell cycle progression and immunoglobulin gene rearrangement, which would occur in a mutually exclusive manner, may be interconnected or coupled to avoid occurrence of genomic instability. ZNF131 suppresses expression of Cdk inhibitor, p21{sup cip1}, and that of pro-apoptotic factors, Bax and Puma, targets of p53, to facilitate cell cycle progression and suppress unnecessary apoptosis, respectively, of pro-B cells. There results demonstrate the essential roles of ZNF131 in coordinating the B cell differentiation and proliferation.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

MagT1 is essential for Drosophila development through the shaping of Wingless and Decapentaplegic signaling pathways

Magnesium transporter subtype 1 (MagT1) is a magnesium membrane transporter with channel like properties. We have previously identified MagT1 (CG7830) in Drosophila genome and characterized its protein product by electrophysiological means. Here, we report the generation of fly MagT1 mutants and show that MagT1 is essential for early embryonic development. In wings and primordial wings, by clonal analysis and RNAi knock down of MagT1, we have found that loss of MagT1 results in enhanced/ectopic Wingless (Wg, a fly Wnt) signaling and disrupted Decapentaplegic (Dpp) signaling, indicating the crucial role of MagT1 for fly development at later stages. Finally, we demonstrate directly that magnesium transportations are proportional with the MagT1 expressional levels in Drosophila S2 cells. Taken together, these findings may suggest that MagT1 is a major magnesium transporter/channel profoundly involved in fly development by affecting developmental signaling pathways, such as Wg and Dpp signaling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

CTP synthase knockdown during early development distorts the nascent vertebral column and causes fluid retention in multiple tissues in zebrafish

Highlights: • Morpholino-based knockdown of ctps during early development produces zebrafish embryos with curved spines and tissue oedema. • Knockdown of ctps1a, and not ctps1b, induces more severe, longer-lasting defects. • Phenotypes are exacerbated when morpholinos against both gene variants are supplied together at uneven ratios. • The same phenotypes were recovered from embryos treated with DON, a CTPS activity-inhibiting drug. CTP Synthase (CTPS) is a metabolic enzyme that is recognized as a catalyst for nucleotide, phospholipid and sialoglycoprotein production. Though the structural characteristics and regulatory mechanisms of CTPS are well-understood, little is known regarding the extent of its involvement during the early developmental stages of vertebrates. Zebrafish carries two CTPS genes, annotated as ctps1a and ctps1b. Phylogenetic analyses show that both genes had diverged from homologues in the ancestral Actinopterygii, Oreochromis niloticus. Conservation of common CTPS-catalytic regions further establishes that both proteins are likely to be functionally similar to hsaCTPS. Here, we show that ctps1a is more critical throughout the initial period of embryonic development than ctps1b. The effects of concurrent partial knockdown are dependent on ctps1a vs ctps1b dosage ratios. When these are equally attenuated, abnormal phenotypes acquired prior to the pharyngula period disappear in hatchlings (48hpf); however, if either gene is more attenuated than the other, these only become more pronounced in advanced stages. Generally, disruption to normal ctps1a or ctps1b expression levels by morpholinos culminates in the distortion of the early spinal column as well as multiple-tissue oedema. Other effects include slower growth rates, increased mortality rates and impaired structural formation of the young fish's extremities. Embryos grown in DON, a glutamine-analogue drug and CTPS antagonist, also exhibit similar characteristics, thus strengthening the validity of the morpholino-induced phenotypes observed. Together, our results demonstrate the importance of CTPS for the development of zebrafish embryos, as well as a disparity in activity and overall importance amongst isozymes.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

NFAT5 promotes in vivo development of murine melanoma metastasis

Highlights: • First time to demonstrate a role of NFAT5 in the development of melanoma. • Depletion of NFAT5 suppresses cell proliferation and migration in vitro. • Depletion of NFAT5 suppresses tumor growth and metastasis in vivo. • NFAT5 as a novel therapeutic target in melanoma. Malignant melanoma is one of the most fatal and aggressive skin cancers, originating from pigment-containing melanocytes. Despite progress in clinical research, treatment options for malignant melanoma have been limited. The nuclear factor of activated T-cell 5 (NFAT5), originally identified as tonicity regulated transcription factor Ton/EBP, is now known as a carcinogenic gene in several types of cancer pathology. In this study, we knocked down NFAT5 to investigate its role in melanoma cancer. shRNA-mediated knockdown of NFAT5 led to a significant decrease in cell proliferation in vitro. Additionally, depletion of NFAT5 inhibited the cell migratory ability of B16BL6 melanoma cells and led to more accumulation at the G2/M phase of the cell cycle. Furthermore, NFAT5 was essential for the development of melanoma cancer pathophysiology in an in vivo mouse model. NFAT5 knockdown-induced tumor growth was slow and tumor volume was significantly reduced compared to mock controls. Moreover, NFAT5 knockdown was associated with a low number of metastatic nodules on the lung and liver. To our knowledge, our data demonstrate for the first time a role of NFAT5 in the development of melanoma. We provide evidence for NFAT5 as a marker of cell migration and metastasis, indicating that NFAT5 represents a novel therapeutic target in melanoma.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

The single-cell transcriptome program of nodule development cellular lineages in Medicago truncatula

Legumes establish a symbiotic relationship with nitrogen-fixing rhizobia by developing nodules. Nodules are modified lateral roots that undergo changes in their cellular development in response to bacteria, but the transcriptional reprogramming that occurs in these root cells remains largely uncharacterized. Here, we describe the cell-type-specific transcriptome response of Medicago truncatula roots to rhizobia during early nodule development in the wild-type genotype Jemalong A17, complemented with a hypernodulating mutant (sunn-4) to expand the cell population responding to infection and subsequent biological inferences. The analysis identifies epidermal root hair and stele sub-cell types associated with a symbiotic response to infection and regulation of nodule proliferation. Trajectory inference shows cortex-derived cell lineages differentiating to form the nodule primordia and, posteriorly, its meristem, while modulating the regulation of phytohormone-related genes. Gene regulatory analysis of the cell transcriptomes identifies new regulators of nodulation, including STYLISH 4, for which the function is validated.

Cell Biology↗