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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 OSTI2018

Glaucocalyxin A attenuates angiotensin II-induced cardiac fibrosis in cardiac fibroblasts

Highlights: • GLA inhibits Ang II-induced proliferation and migration of CFs. • GLA prevents the differentiation of CFs to myofibroblasts. • GLA inhibits the production of ECM and MMPs in Ang II-stimulated CFs. • GLA prevents TGF-β1/Smad3 pathway activation induced by Ang II in CFs. Glaucocalyxin A (GLA) is a natural ent-Kaurane diterpenoid that possesses cardioprotective effect. Recently, it has been reported that GLA inhibits liver and pulmonary fibrosis, whereas its role in cardiac fibrosis remains unknown. In the present study, we evaluated the effect of GLA on the pathogenesis of cardiac fibrosis in vitro. The results showed that GLA inhibited angiotensin II (Ang II)-induced proliferation and migration in cardiac fibroblasts (CFs). GLA reduced the expression of alpha-smooth muscle actin (α-SMA) in Ang II-induced CFs, suggesting that GLA prevented the differentiation of CFs to myofibroblasts. Furthermore, the production of extracellular matrix (ECM) components including type I collagen (Col-I) and fibronectin, as well as the matrix metalloproteinases (MMPs) including MMP-2 and MMP-9 were reduced by GLA in Ang II-induced CFs. In addition, GLA prevented the Ang II-induced activation of transforming growth factor beta 1 (TGF-β1)/Smad3 pathway in CFs. Collectively, our results demonstrated that GLA acted as an anti-fibrotic agent in cardiac fibrosis, which might be mediated by the regulation of TGF-β1/Smad3 pathway. GLA might be an attractive candidate for improving the prognosis of acute myocardial infarction (AMI) by controlling the cardiac fibrosis.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Effects of low-magnitude high-frequency vibration on osteoblasts are dependent on estrogen receptor α signaling and cytoskeletal remodeling

Clinical and experimental studies demonstrate the potential of low-magnitude high-frequency vibration (LMHFV) to enhance bone formation in the intact skeleton and during fracture healing. Moreover, it was shown that the effects of vibration therapy during fracture healing are highly dependent on the estrogen status of the vibrated individual and that estrogen receptor (ER) α signaling plays a major role in mechanotransduction of LMHFV. Because it is known that LMHFV can directly act on osteogenic cells, we hypothesize that the differential effects of LMHFV in the presence and absence of estrogen are mediated by ERα signaling in osteoblasts. To prove this hypothesis, we subjected preosteoblastic MC3T3-E1 cells and primary osteoblasts to LMHFV in vitro. We found increased Cox2 gene expression, cell metabolic activity and cell proliferation after LMHFV in the absence of estrogen, whereas the effects were contrary in the presence of estrogen. Blocking of ERα signaling by Esr1-siRNA knockdown or adding the selective ERα antagonist MPP dihydrochloride abolished the effects of LMHFV on osteoblast proliferation and Cox2 expression. Furthermore, primary osteoblasts isolated from ERα-knockout mice did not show a response towards LMHFV in the presence of estrogen. Additionally, blocking of actin cytoskeletal remodeling by adding the p160ROCK inhibitor Y-27632 abolished the effects of LMHFV. In contrast, expression of primary cilium was not necessary for mechanotransduction of LMHFV. These results suggest that direct effects of LMHFV on osteoblasts are dependent on ERα signaling and cytoskeletal remodeling.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Effects of Icaritin on the physiological activities of esophageal cancer stem cells

Highlights: • CSCs were used instead of using cancer cells. • The effect of Icaritin on the Hedgehog and Wnt signaling pathway was investigated. • Our study found that Icaritin down-regulated the level of Hedgehog, Smo and Gli in Hedgehog pathway, up-regulated GSK3β and down-regulated Wnt and β-catenin in Wnt pathway, indicating that Icaritin may inhibit the activity of esophageal CSCs through regulating the expression of proteins in important pathways related to esophageal cancer. Icaritin is a compound extracted from herb, recent study have found it is able to influence the activity of various types of cancer. Our aim was to investigate the effects of Icaritin on the physiological activities of esophageal cancer stem cells (CSCs). In this study, esophageal cancer cells were cultured and CD133 positive esophageal CSCs were sorted by flow cytometry. Changes in the physiological activity of esophageal CSCs following treatment with different concentrations of Icaritin (0, 12.5, 25, 50, and 100 μmol/L) were evaluated. The CCK-8 method and Transwell assay were used to determine the effects of Icaritin on the proliferation, migration, and invasion of esophageal CSCs. Flow cytometery was used to investigate its effect on the apoptosis of CSCs. The effect of Icaritin on the expression of proteins in Wnt and Hedgehog signaling pathways were determined using western blot test. Consequently, Icaritin inhibited the proliferation, migration, and invasion of esophageal CSCs in a dose-dependent manner. It promoted cell apoptosis, and influenced the levels of proteins in Wnt and Hedgehog signaling pathways. It may act as a promising drug in the therapy of esophageal cancer.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

The role of Zhx2 transcription factor in bipolar cell differentiation during mouse retinal development

Highlights: • Zhx2 is expressed in developing retina. • Zhx2 is essential for subsets of bipolar cell proper differentiation. • Overexpression of Zhx2 showed perturbation of bipolar differentiation. We found that the Zhx2 gene (whose product is known to act as a tumor suppressor in hepatocellular carcinoma) is expressed in embryonic retinal progenitors and in developing cone bipolar cells in the postnatal retina, as well as in Müller glia in the mature retina. To examine the functions of Zhx2 protein during retinal development, we performed loss- and gain-of-function analyses using a retinal explant culture system. We introduced a plasmid encoding Zhx2 shRNA into isolated mouse retinas at E17.5, and the retinas were cultured as explants. After 3 days of culture, proliferation was slightly enhanced, leading to retinas thicker than in the control, but this phenomenon was observed only transiently. After 14 days of the culture, the thickness and gross morphology of retinas expressing sh-Zhx2 were indistinguishable from those of the control. The numbers of rod cells, amacrine cells, and Müller glia were the same in both groups. However, although the total number of bipolar cells was the same, the experimental group saw an increased population of ON bipolar cells, and decreased numbers of a subset of OFF bipolar cells. We also examined the effects of overexpression of Zhx2. Although Zhx2 acts as a tumor suppressor, its overexpression in developing retinas did not lead to any discernible difference in retinal thickness, suggesting that proliferation activity was not affected. After 14 days of explant culture, the total number of bipolar cells decreased, and subset composition was altered. Taken together, these results suggest that Zhx2 plays roles in the regulation of bipolar cell subset fate determination during retinal development.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

In vitro large scale production of megakaryocytes to functional platelets from human hematopoietic stem cells

Highlights: • Human HSCs were isolated from donor, showed positive to CD34 and CD133 and negative to CD90 and CD73. • These HSCs were induced in novel PI-LC and PII-LC to MKs and platelets differentiation. • The PII-LC (contains andrographolide) showed high MKs production as evidence from flow cytometry and CFU-MK. • The DNA ploidy also showed up to 32 N polyploidy in PII-LC induced MKs compared to PI-LC. • Further, western blotting and qRT-PCR showed high expression of MKs specific genes in PII-LC induced MKs. Megakaryocytopoiesis results in the formation of platelets, which are essential for hemostasis. Decreased production or increased destruction of platelets can cause thrombocytopenia, in which platelet transfusion is the mode of treatment. The present study is aimed in generation of megakaryocytes (MKs) and platelet from human hematopoietic stem cells (HSCs). The purity of HSCs was assessed through Flow cytometry and immunocytochemistry (ICC) studies. These pure HSCs were induced with thrombopoietin (TPO), similarly with Andrographis paniculata extract (APE) for 21 days to generate MKs. The APE is mainly composed of andrographolide which stimulates TPO from the liver, and this binds to CD110 present on the surface of HSCs and triggers the proliferation of HSCs and initiate higher MKs population subsequently, a large number of platelets. The results of the present study showed increased proliferation of HSCs grown in the presence of APE and revealed a high population of CD41a and CD42b positive MKs as enumerated by Flow cytometry compared with TPO induced MKs. These results also concurred with qRT-PCR and western blot analysis. The scanning electron microscopy (SEM) revealed the morphology of differentiated MKs and platelets were similar to human blood platelets. The differentiated MKs in APE exhibited polyploidy up to 32 N while TPO induced MKs showed polyploidy of 8 N, these results corroborated with colony forming unit assay. On thrombin stimulation, high expression of P-selectin (CD62p) and fibrinogen binding were detected in APE induced platelets. Autologous transplantation of platelets generated from APE may be a useful option in thrombocytopenia condition.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Evaluation of collagen mixture on promoting skin wound healing in zebrafish caused by acetic acid administration

The aim of this study is to use zebrafish embryos as a quick platform for wound healing studies. At beginning, we optimized a protocol to induce skin lesion by acetic acid injection. The acetic acid injection induced regional inflammation wound hyperpigmentation by recruiting pigment cells to the wound area. Later, we applied established platform to evaluate the effect of tilapia's collagen peptide mixtures, including demonstration on promoting skin wound healing and eliminating inflammatory response. Results showed that after treating TY001, one of the above fish collagen peptide mixtures, not only repair and proliferation were induced, but also death and apoptosis cells were cleared within cutaneous lesion. Moreover, inflammatory response was suppressed along with collagen mixture treatment. Finally, the TY001-associated signaling was validated by real time-PCR, and numbers of gene associated with tissue repair and vessel proliferation were induced. To sum up, our findings provided a permissive model that may apply to generate a platform for further screening on repair and restoration technology. In addition, the tilapia fish collagen peptide mixture we applied on our model has great potential on developing clinical application on wound healing.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Von Hippel-Lindau (VHL) protein antagonist, VH298, promotes functional activities of tendon-derived stem cells and accelerates healing of entheses in rats by inhibiting ubiquitination of hydroxy-HIF-1α

Enthesis is the region where a tendon attaches to a bone. It is a relatively vulnerable position, and in most cases surgical treatment is required upon rupture. The reconstructed enthesis is usually weaker compared to the original, and is prone to rupture again. Hypoxia-inducible factor-1 α (HIF-1α) is known to be involved in extensive activities in cells. It is inhibited under normoxic conditions, and undergoes two essential processes, hydroxylation and ubiquitination, the latter of which has been largely unexplored. Herein, we measured the levels of HIF-1α and hydroxy-HIF-1α in VH298-treated rat tendon-derived stem cells (TDSCs) by immunoblotting. We also detected the proliferation of TDSCs using CCK-8 assay and the mRNA levels of related genes by quantitative RT-PCR. The TDSCs were observed to be induced and the chondrogenic differentiation related genes were found to be enhanced. We also simulated in-vitro wounding in a scratch test and reconstructed the enthesis in a rat model of Achilles tendon by classical surgery followed by administration of phosphate buffer saline (PBS) injection or VH298 injection. We observed that HIF-1α and hydroxy-HIF-1α levels were increased in VH298-treated TDSCs in a dose- and time-dependent manner. Thirty micromolar VH298 could significantly increase cell proliferation, migration, and expression of collagen-1α, collagen-3α, decorin, tenomodulin, tenascin C genes, and chondrogenic differentiation-related genes, collagen-2α, SRY-box9, aggrecan. VH298-treated enthesis could tolerate more load-to-failure, had a better healing pattern, and activation of HIF signaling pathway. VH298 can thus enhance the functional activities of TDSCs, enhance their chondrogenic differentiation potential, and accelerate enthesis healing by inhibiting the ubiquitination of hydroxy-HIF-1α.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Antibiotic anisomycin selectively targets leukemia cell lines and patient samples through suppressing Wnt/β-catenin signaling

Highlights: • Anisomycin effectively targets CML cell lines and CD34 stem/progenitor cells. • Anisomycin has little or no effect on normal bone marrow (NBM) CD34 cells. • Anisomycin acts on CML cells through inhibiting Wnt/β-catenin signaling pathway. • Anisomycin augments the effects of BCR-ABL TKI in CML. Chronic myeloid leukemia (CML) responds well to BCR-ABL tyrosine kinase inhibitors (TKI), such as imatinib and dasatinib. However, these inhibitors have been less effective as single agents in the blast phase-CML. In this work, we show that anisomycin, a clinically available drug, targets CML cells at all stages of development and enhances BCR-ABL TKIs’ efficacy. Anisomycin at nanomolar concentration inhibits proliferation and induces apoptosis in a panel of CML cell lines in a dose-dependent manner. It induces apoptosis CD34 stem/progenitor cells isolated from patients with blast phase CML. Using colony formation and serial replating assays, we further show that anisomycin inhibits CML CD34 cell differentiation, proliferation and self-renewal. Additionally, anisomycin is less effective in normal bone marrow (NBM) CD34 cells, suggesting the selective anti-leukemia activity of anisomycin. Combination of anisomycin with imatinib or dasatinib achieves significantly better efficacy than TKI alone in leukemia cell lines and patient samples while sparing normal counterparts. Mechanistically, we demonstrate that p38 MAPK/JNK activation is not required for anti-leukemia activities of anisomycin. Instead, anisomycin displays preferential inhibitory effects to Wnt/β-catenin-mediated signaling in CML. Our work provides the preclinical evidence on the potent efficacy of anisomycin in leukemia and its mechanisms of action. Our work suggests that anisomycin is a potential drug to overcome resistance to BCR-ABL TKI treatment in blast phase CML.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Quantification of glioblastoma progression in zebrafish xenografts: Adhesion to laminin alpha 5 promotes glioblastoma microtumor formation and inhibits cell invasion

Highlights: • Developed an embryo-larval zebrafish model to study GBM progression. • Quantitatively measured GBM BV association, invasion and microtumor formation. • Laminin alpha 5 decreases U251MG dispersal and increases microtumors. • Microenvironmental laminin alpha 5 slows U251MG cell invasion in vivo. Glioblastoma (GBM) is a deadly disease due to its ability to quickly invade and destroy brain tissue. Slowing or stopping GBM cell progression is crucial to help those inflicted with the disease. Our lab created an embryo-larval zebrafish xenograft model as a tool to study human GBM progression in an observable brain environment. The zebrafish brain is a dynamic and complex environment providing an optimal setting for studying GBM cell progression. Here we demonstrate the ability of our model to quantitate GBM proliferation, dispersal, blood vessel association, microtumor formation, and individual cell invasion by evaluating the importance of an extracellular matrix protein, laminin alpha 5 (lama5), on U251MG cell progression. Lama5 has been implicated in cancer cell survival, proliferation and invasion and is a known adhesion site for GBM cells. While lama5 is highly expressed in endothelial cells in the brain, it is unknown how lama5 affects GBM behavior. Using a lama5 morpholino, we discovered that lama5 decreased U251MG dispersal by 23% and doubles the formation of blood vessel dependent microtumors. Despite lama5 being a known attachment site for GBM, lama5 expression had no effect on U251MG association with blood vessels. Analysis of individual U251MG cells revealed lama5 significantly lowered invasion as mobile U251MG cells traveled 32.5 μm less, invaded 5.0 μm/hr slower and initiated invasion 60% few times per cell.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Retinoic acid co-treatment aggravates severity of dioxin-induced skin lesions in hairless mice via induction of inflammatory response

Highlights: • Treatment with retinoic acid (RA) is ineffective for dioxin-induced skin lesions in mice. • Co-treatment with dioxin and RA results in psoriasis-like phenotype not seen under treatment with either compound alone. • Strong inflammation is the most prominent effect induced by combined treatment with dioxin and RA. Exposure to toxic halogenated polyaromatic hydrocarbons, of which 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is the most potent, induces diverse skin pathologies in humans, including chloracne, hyperkeratosis, hamartomas, etc. While the toxic effects of TCDD have been extensively studied, effective approaches to their treatment are still lacking. Retinoids are commonly used in therapy of acneiform skin diseases. In vitro, retinoids elicit antagonistic effects on keratinocyte differentiation and proliferation, as compared to TCDD, suggesting their potential in treatment of TCDD-induced skin lesions. Nevertheless, the modulation of TCDD activity in skin by retinoids in vivo was never reported. We have used N-TERT keratinocyte cell line and hairless (hr) mice to determine if retinoic acid (RA) can lessen or reverse TCDD-induced effects in vitro and in vivo. RA co-treatment suppressed TCDD-induced changes in the expression of differentiation-associated genes and N-TERT keratinocyte viability in vitro. However, in hairless mice (in vivo), RA/TCDD co-treatment produced more severe effects, than treatment with either of the two compounds individually. RA/TCDD co-application to mouse skin strongly stimulated keratinocyte proliferation, resulting in dramatic epidermal hyperplasia. It has also led to massive immune cell infiltration into the dermis, and increased mRNA expression of inflammation markers, including IL1β, IL6 and S100A7. Thus, retinoids not only appeared ineffective in treatment of TCDD-induced skin lesions in hairless mice, but also resulted in their exaggeration. These in vivo results question previous cell culture-based claims that RA may reduce TCDD-induced skin effects and caution against the reliance on in vitro data in TCDD toxicology research.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Long noncoding RNA LINC00165-induced by STAT3 exerts oncogenic properties via interaction with Polycomb Repressive Complex 2 to promote EMT in gastric cancer

Long non-coding RNAs (lncRNAs) are a crucial member of the non-coding RNA family, and increasing evidence demonstrates that lncRNAs participate in the initiation and progression of cancers. Our study aimed to explore the role of the lncRNA LINC00165 in gastric cancer (GC) development. In the present study, our results showed that LINC00165 was upregulated in GC tissues and cell lines and high expression of LINC00165 was correlated with tumor-node-metastasis stage, invasion depth, and overall survival of GC patients. Functional assays showed that LINC00165 knockdown inhibited the proliferation, migration and invasion of GC cells and LINC00165 overexpression stimulated their proliferation, migration and invasion. Online transcription factor binding site prediction analysis showed that there were STAT3 binding sites in the LINC00165 promoter region. Furthermore, luciferase reporter and chromatin immunoprecipitation assays provided evidence that STAT3 could bind directly to the region between −547 bp to −537 bp (ATGTTGGGAAA) of LINC00165 promoter and activate its transcription. Then GC cells were partitioned into nuclear and cytoplasmic fractions and we found that LINC00165 was localized preferentially to the nucleus. Mechanistically, we revealed that LINC00165 functioned as a scaffold for interaction with Polycomb Repressive Complex 2 to promote the epithelial-mesenchymal transition in GC cells. Taken together, our study revealed that LINC00165 was involved in the progression and poor prognosis of GC as an oncogenic role. Therefore, LINC00165 might become a new potential target for GC chemotherapy and further predict prognosis of patients.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2018

Long noncoding RNA MAGI2-AS3 regulates CCDC19 expression by sponging miR-15b-5p and suppresses bladder cancer progression

Highlights: • Expression of MAGI2-AS3, miR-15b-5p and CCDC19 in BCa. • MAGI2-AS3 regulates miR-15b-5p/CCDC19 cascade expression in BCa. • CCDC19 knockdown partly reverses the effects caused by MAGI2-AS3 overexpression in vitro. • MAGI2-AS3 suppresses BCa growth in vivo. Bladder cancer (BCa) belongs to a popular urological malignancy and leads to large numbers of deaths worldwide. Recently, emerging evidences indicate that long noncoding RNAs (lncRNAs) are closely related with BC occurrence and progression. However, the function of lncRNA MAGI2-AS3 remains poorly understood in BC. In this present study, we screened out a novel lncRNA MAGI2-AS3 whose expression was downregulated in BCa tissues. We showed that MAGI2-AS3 downregulation in BCa patients indicated a poor prognosis. Functionally, we showed that MAGI2-AS3 overexpression inhibits proliferation, migration and invasion of BCa cells. Moreover, ectopic expression of MAGI2-AS3 suppresses BCa growth in vivo. Bioinformatics analysis revealed that MAGI2-AS3 could serve as a competing endogenous RNA (ceRNA) for miR-15b-5p. In the meantime, miR-15b-5p directly targeted CCDC19, a tumor suppressor in BCa. Rescue assays demonstrated that knockdown of CCDC19 restored the proliferation, migration and invasion of BCa cells suppressed by MAGI2-AS3 overexpression. In conclusion, this study identified a novel mechanism that MAGI2-AS3/miR-15b-5p/CCDC19 signaling pathway regulates BCa progression.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2015

A Designed Inhibitor of p53 Aggregation Rescues p53 Tumor Suppression in Ovarian Carcinomas

Half of all human cancers lose p53 function by missense mutations, with an unknown fraction of these containing p53 in a self-aggregated amyloid-like state. In this paper we show that a cell-penetrating peptide, ReACp53, designed to inhibit p53 amyloid formation, rescues p53 function in cancer cell lines and in organoids derived from high-grade serous ovarian carcinomas (HGSOC), an aggressive cancer characterized by ubiquitous p53 mutations. Rescued p53 behaves similarly to its wild-type counterpart in regulating target genes, reducing cell proliferation and increasing cell death. Intraperitoneal administration decreases tumor proliferation and shrinks xenografts in vivo. Our data show the effectiveness of targeting a specific aggregation defect of p53 and its potential applicability to HGSOCs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

BefA, a microbiota-secreted membrane disrupter, disseminates to the pancreas and increases β cell mass

Microbiome dysbiosis is a feature of diabetes, but how microbial products influence insulin production is poorly understood. Here, we report the mechanism of BefA, a microbiome-derived protein that increases proliferation of insulin-producing β cells during development in gnotobiotic zebrafish and mice. BefA disseminates systemically by multiple anatomic routes to act directly on pancreatic islets. We detail BefA’s atomic structure, containing a lipid-binding SYLF domain, and demonstrate that it permeabilizes synthetic liposomes and bacterial membranes. A BefA mutant impaired in membrane disruption fails to expand β cells, whereas the pore-forming host defense protein, Reg3, stimulates β cell proliferation. Our work demonstrates that membrane permeabilization by microbiome-derived and host defense proteins is necessary and sufficient for β cell expansion during pancreas development, potentially connecting microbiome composition with diabetes risk.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

In vitro functional screening as a means to identify new plasticizers devoid of reproductive toxicity

Plasticizers are indispensable additives providing flexibility and malleability to plastics. Among them, several phthalates, including di (2-ethylhexyl) phthalate (DEHP), have emerged as endocrine disruptors, leading to their restriction in consumer products and creating a need for new, safer plasticizers. The goal of this project was to use in vitro functional screening tools to select novel non-toxic plasticizers suitable for further in vivo evaluation. A panel of novel compounds with satisfactory plasticizer properties and biodegradability were tested, along with several commercial plasticizers, such as diisononyl-cyclohexane-1,2-dicarboxylate (DINCH®). MEHP, the monoester metabolite of DEHP was also included as reference compound. Because phthalates target mainly testicular function, including androgen production and spermatogenesis, we used the mouse MA-10 Leydig and C18-4 spermatogonial cell lines as surrogates to examine cell survival, proliferation, steroidogenesis and mitochondrial integrity. The most promising compounds were further assessed on organ cultures of rat fetal and neonatal testes, corresponding to sensitive developmental windows. Dose-response studies revealed the toxicity of most maleates and fumarates, while identifying several dibenzoate and succinate plasticizers as innocuous on Leydig and germ cells. Interestingly, DINCH®, a plasticizer marketed as a safe alternative to phthalates, exerted a biphasic effect on steroid production in MA-10 and fetal Leydig cells. MEHP was the only plasticizer inducing the formation of multinucleated germ cells (MNG) in organ culture. Overall, organ cultures corroborated the cell line data, identifying one dibenzoate and one succinate as the most promising candidates. The adoption of such collaborative approaches for developing new chemicals should help prevent the development of compounds potentially harmful to human health. - Highlights: • Phthalate plasticizers exert toxic effects on male reproduction. • Reproductive toxicity of new plasticizers was assessed by functional assays. • Mouse Leydig and germ cell lines, and rat perinatal testis cultures were used. • Survival, proliferation, steroidogenesis, abnormal germ cell formation were examined. • Reproductive toxic and innocuous plasticizer candidates were identified.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2017

Hydro-dam – A nature-based solution or an ecological problem: The fate of the Tonlé Sap Lake

Recent proliferation of hydro-dams was one of the nature-based solutions to meet the increasing demand for energy and food in the Lower Mekong River Basin (LMRB). While construction of these hydro-dams generated some hydropower and facilitated expansion of irrigated lands, it also significantly altered the basin-wide hydrology and subsequently impacted wetland ecosystems. Unintended adverse consequences of ecosystem services from lakes and wetlands offset the intended gains in hydroelectricity and irrigated agriculture. The trade-offs between gains in energy and food production and losses in aquatic ecosystem services were perceived to be significant but knowledge of the magnitude, spatial extent, and type of ecosystem services change is lacking and, therefore, the question whether the hydro-dam is an optimized solution or a potential ecological problem remains unanswered. In this study, as the first step to answer this question and using the Tonlé Sap Lake as an example, we quantified one of the impacts of hydro-dams on lake ecosystem's phenology in terms of open water area, a critical ecological characteristic that affects lake systems’ fish production, biodiversity, and livelihoods of the local communities. We used the MODIS-NDVI time series, forecast function and the Mann-Kendall trend test method to first quantify the open water area, analyzed its changes over time, and then performed correlation analysis with climate variables to disentangle dam impacts. The results showed reduced hydro-periods, diminishing lake seasonality and a declining trend in Tonlé Sap Lake open water area over the past 15 years. These changes were insignificantly related to climatic influence during the same period. It is concluded that basin-wide hydro-dam construction and associated agricultural irrigation were deemed to be the primary cause of these ecological changes. Further analyses of changes in the lake's ecosystem services, including provision and cultural services, need to be carried out in order to have a holistic understanding of the trade-offs brought by the hydro-dam proliferation as a solution to the emerging energy and food demand in the LMRB. - Highlights: • The open water area of the Tonlé Sap Lake has declined over the past 15 years. • Hydro-dam construction is a key factor responsible for such lake phenological loss. • Climate doesn’t contribute much. • Tradeoffs should be evaluated to help establish an optimized nature-based solution.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2021

In vitro effects of cannabidiol and its main metabolites in mouse and human Sertoli cells

Cannabidiol (CBD) is a major cannabinoid present in extracts of the plant Cannabis sativa (marijuana). While the therapeutic effects of CBD on epilepsy have been demonstrated, less is understood regarding its potential adverse effects. Recent studies revealed that CBD induced toxicity in the male reproductive system of animal models. In this study, we used TM4, an immortalized mouse Sertoli cell line, and primary human Sertoli cells to evaluate the toxicities of CBD and its main metabolites, 7-carboxy-CBD and 7-hydroxy-CBD. CBD induced concentration- and time-dependent cytotoxicity in mouse and human Sertoli cells, which mainly resulted from the inhibition of the G1/S-phase cell cycle transition. CBD also inhibited DNA synthesis and downregulated key cell cycle proteins. Moreover, CBD reduced the mRNA and protein levels of a functional marker, Wilms’ tumor 1. Similar to CBD, 7-carboxy-CBD and 7-hydroxy-CBD inhibited cellular proliferation and decreased DNA synthesis. 7-Carboxy-CBD was less cytotoxic than CBD, while 7-hydroxy-CBD showed comparable cytotoxicity to CBD in both mouse and human Sertoli cells. Compared to mouse Sertoli cells, CBD, 7-hydroxy-CBD, and 7-carboxy-CBD were more cytotoxic in human Sertoli cells. Finally, our results indicate that CBD and its main metabolites can inhibit cell proliferation in mouse and human Sertoli cells.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2015

Persistent DNA Damage in Spermatogonial Stem Cells After Fractionated Low-Dose Irradiation of Testicular Tissue

Purpose: Testicular spermatogenesis is extremely sensitive to radiation-induced damage, and even low scattered doses to testis from radiation therapy may pose reproductive risks with potential treatment-related infertility. Radiation-induced DNA double-strand breaks (DSBs) represent the greatest threat to the genomic integrity of spermatogonial stem cells (SSCs), which are essential to maintain spermatogenesis and prevent reproduction failure. Methods and Materials: During daily low-dose radiation with 100 mGy or 10 mGy, radiation-induced DSBs were monitored in mouse testis by quantifying 53 binding protein 1 (53BP-1) foci in SSCs within their stem cell niche. The accumulation of DSBs was correlated with proliferation, differentiation, and apoptosis of testicular germ cell populations. Results: Even very low doses of ionizing radiation arrested spermatogenesis, primarily by inducing apoptosis in spermatogonia. Eventual recovery of spermatogenesis depended on the survival of SSCs and their functional ability to proliferate and differentiate to provide adequate numbers of differentiating spermatogonia. Importantly, apoptosis-resistant SSCs resulted in increased 53BP-1 foci levels during, and even several months after, fractionated low-dose radiation, suggesting that surviving SSCs have accumulated an increased load of DNA damage. Conclusions: SSCs revealed elevated levels of DSBs for weeks after radiation, and if these DSBs persist through differentiation to spermatozoa, this may have severe consequences for the genomic integrity of the fertilizing sperm.

62 RADIOLOGY AND NUCLEAR MEDICINE↗