Selected Grantee Publications
Lipocalin-2 Is an Anorexigenic Signal in Primates
Petropoulou et al., eLife. 2020.
https://doi.org/10.7554/eLife.58949
The hormone lipocalin-2 (LCN2) suppresses food intake in mice. Researchers demonstrated that LCN2 increases after a meal and reduces hunger in people with normal weight or overweight, but not in obese individuals. The researchers also showed that LCN2 crosses the blood-brain barrier and binds to the hypothalamus in vervet monkeys. LCN2 was found to bind to the hypothalamus in human, baboon, and rhesus macaque brain sections. When injected into vervets, LCN2 suppressed food intake and lowered body weight without toxic effects in short-term experiments. These findings lay the groundwork to investigate whether LCN2 might be a useful treatment for obesity. Supported by ORIP (P40OD010965), NCATS, NIDDK, NIA, and NHLBI.
Estrogen Acts Through Estrogen Receptor 2b to Regulate Hepatobiliary Fate During Vertebrate Development
Chaturantabut et al., Hepatology. 2020.
https://aasldpubs.onlinelibrary.wiley.com/doi/full/10.1002/hep.31184
During liver development, bipotent progenitor cells differentiate into hepatocytes and biliary epithelial cells to ensure a functional liver. The developmental cues controlling the differentiation of committed progenitors into these cell types are not completely understood. These authors report an essential role for estrogenic regulation in vertebrate liver development to affect hepatobiliary fate decisions. The studies identify17β-estradiol (E2), nuclear estrogen receptor 2b (esr2b), and downstream bone morphogenetic protein (BMP) activity as important regulators of hepatobiliary fate decisions during vertebrate liver development. These results have significant implications for liver development in infants exposed to abnormal estrogen levels or estrogenic compounds during pregnancy. Supported by ORIP (R24OD017870) and NIDDK.
Fructose Stimulated De Novo Lipogenesis Is Promoted by Inflammation
Jelena et al., Nature Metabolism. 2020.
https://pubmed.ncbi.nlm.nih.gov/32839596
Non-alcoholic fatty liver disease (NAFD) affects 30% of adult Americans. While NAFD starts as simple steatosis with little liver damage, its severe manifestation as non-alcoholic steatohepatitis (NASH) is a leading cause of liver failure, cirrhosis, and cancer. Fructose consumption is proposed to increase the risk of hepatosteatosis and NASH. Excessive intake of fructose causes barrier deterioration and low-grade endotoxemia. Using a mouse model, the study examined the mechanism of how fructose triggers these alterations and their roles in hepatosteatosis and NASH pathogenesis. The results demonstrated that microbiota-derived Toll-like receptor (TLR) agonists promote hepatosteatosis without affecting fructose-1-phosphate (F1P) and cytosolic acetyl-CoA. Activation of mucosal-regenerative gp130 signaling, administration of the YAP-induced matricellular protein CCN1 or expression of the antimicrobial peptide Reg3b (beta) counteract fructose-induced barrier deterioration, which depends on endoplasmic-reticulum stress and subsequent endotoxemia. Endotoxin engages TLR4 to trigger TNF production by liver macrophages, thereby inducing lipogenic enzymes that convert F1P and acetyl-CoA to fatty acid in both mouse and human hepatocytes. The finding may be of relevance to several common liver diseases and metabolic disorders. Supported by ORIP (S10OD020025), NCI, NIEHS, NIDDK, NIAID, and NIAAA.
Antiretroviral Therapy Does Not Reduce Tuberculosis Reactivation in a Tuberculosis-HIV Coinfection Model
Ganatra et al., Journal of Clinical Investigation. 2020.
https://www.jci.org/articles/view/136502
Despite treatment of HIV with antiretroviral therapy (ART), the risk of tuberculosis (TB) reactivation is higher in HIV-infected than HIV-uninfected persons. Researchers used Mycobacterium tuberculosis/SIV-coinfected rhesus macaques to model the impact of ART on TB reactivation due to HIV-induced immunosuppression. ART significantly reduced viral loads and increased CD4+ T-cell counts in blood, spleen, and bronchoalveolar lavage samples, but it did not reduce the risk of SIV-induced TB reactivation during the early phase of treatment. This study offers a translational model for the investigation of TB/SIV coinfection and the evaluation of treatment regimens to prevent TB reactivation in HIV-infected individuals. Supported by ORIP (P51OD011133, P51OD011132) and NIAID.
Intra-Strain Genetic Variation of Platyfish (Xiphophorus maculatus) Strains Determines Tumorigenic Trajectory
Lu et al., Frontiers in Genetics . 2020.
https://www.frontiersin.org/articles/10.3389/fgene.2020.562594/full
Xiphophorus interspecies hybrids represent a valuable model system to study heritable tumorigenesis. Although the ancestors of the two X. maculatus parental lines, Jp163 A and Jp163 B, were siblings produced by the same mother, backcross interspecies hybrid progeny between X. hellerii and X. maculatus Jp163 A develop spontaneous melanoma initiating at the dorsal fin due to a regulator encoded by the X. maculatus genome; the backcross hybrid progeny with X. hellerii or X. couchianus and Jp163 B exhibit melanoma on their flanks. Comparative genomic analyses revealed genetic differences are associated with pathways highlighting fundamental cellular functions. Disruption of these baselines may give rise to spontaneous or inducible tumorigenesis. Supported by ORIP (R24OD011120), NCI, and NIGMS.
Induction and Characterization of Pancreatic Cancer in a Transgenic Pig Model
Boas et al., PLOS One. 2020.
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0239391
Preclinical testing of new therapies for pancreatic cancer has been challenging due to lack of a suitable large animal model. Pigs, however, have similar physiology and immune response to humans. Boas et al report the development of a porcine model for pancreatic cancer. H&E and immunohistochemical stains revealed undifferentiated carcinomas, like those of human pancreatobiliary systems. In several pigs, angiographies revealed that the artery supplying the pancreatic tumor could be catheterized using a 2.4 F microcatheter. In summary, pancreatic cancer can be induced in a transgenic pig, and intra-arterial procedures using catheters designed for human interventions were feasible in this model. Supported by ORIP (U42OD011140) and NCI.
Epidemiological and Molecular Characterization of a Novel Adenovirus of Squirrel Monkeys After Fatal Infection During Immunosuppression
Rogers et al., Microbial Genomics. 2020.
https://pubmed.ncbi.nlm.nih.gov/32614763/
Adenoviruses frequently cause upper respiratory tract infections, often causing disseminated disease in immunosuppressed patients. A novel adenovirus was identified, squirrel monkey adenovirus 1 (SqMAdV-1), as the cause of a fatal infection in an immunocompromised squirrel monkey (Saimiri boliviensis). A nucleotide polymorphism at the stop codon of the DNA polymerase gene results in a 126 amino acid extension at the carboxy terminus. A single adenovirus variant, SqMAdV-3, has similarity to tufted capuchin (Sapajus apella) adenoviruses. The largest group of adenovirus variants detected, SqMAdV-2.0-2.16, has high similarity (93-99%) to the TMAdV, suggesting that squirrel monkeys may be the natural host of the TMAdV. Supported by ORIP (P40OD010938, R24OD018553), and NIAID.
3-D Printed Customizable Vitrification Devices for Preservation of Genetic Resources of Aquatic Species
Tiersch et al., Aquacultural Engineering. 2020.
https://www.sciencedirect.com/science/article/pii/S0144860920300406
Sperm vitrification as an alternative approach to conventional cryopreservation allows quick and low-cost sample preservation and is suitable for small-bodied aquatic species with miniscule testis, fieldwork at remote locations, and small-scale freezing for research purposes. Tiersch et al. report the developing of operational prototypes of 3-dimensional (3-D) printed vitrification devices. This study demonstrated the feasibility of developing standardized low-cost devices fabricated by 3-D printing with functions including vitrification, volume control, labeling, protection, and storage. These prototypes can be further developed to assist development of germplasm repositories to protect the genetic resources of aquatic species by breeders, hatcheries, aquariums, and researchers. Supported by ORIP (R24OD010441).
Fluorescence-Based Sorting of Caenorhabditis elegans via Acoustofluidics
Zhang et al., Lab on a Chip. 2020.
The authors present an integrated acoustofluidic chip capable of identifying worms of interest based on expression of a fluorescent protein in a continuous flow and then separate them in a high-throughput manner. Utilizing planar fiber optics, their acoustofluidic device requires no temporary immobilization of worms for interrogation/detection, thereby improving the throughput. The device can sort worms of different developmental stages (L3 and L4 stage worms) at high throughput and accuracy. In their acoustofluidic chip, the time to complete the detection and sorting of one worm is only 50 ms, which outperforms nearly all existing microfluidics-based worm sorting devices. Supported by ORIP (R43OD024963), NIEHS, and NIDDK.