Selected Grantee Publications
Cannabinoid Control of Gingival Immune Activation in Chronically SIV-Infected Rhesus Macaques Involves Modulation of the Indoleamine-2,3-Dioxygenase-1 Pathway and Salivary Microbiome
McDew-White et al., EBioMedicine. 2021.
https://pubmed.ncbi.nlm.nih.gov/34954656/
HIV-associated periodontal disease (PD) affects people living with HIV (PLWH) on combination anti-retroviral therapy (cART). Researchers used a systems biology approach to investigate the molecular, metabolome, and microbiome changes underlying PD and its modulation by phytocannabinoids (Δ9-THC) in rhesus macaques. Δ9-THC reduced IDO1 protein expression. The findings suggest that phytocannabinoids may help reduce gingival/systemic inflammation, salivary dysbiosis, and potentially metabolic disease in PLWH on cART. Supported by ORIP (P51OD011104, P51OD011133, U42OD010442), NIAID, NIDA, NIDDK, NIDCR, and NIMH.
Deep Learning Is Widely Applicable to Phenotyping Embryonic Development and Disease
Naert et al., Development. 2021.
https://pubmed.ncbi.nlm.nih.gov/34739029/
Genome editing simplifies the generation of new animal models for congenital disorders. The authors illustrate how deep learning (U-Net) automates segmentation tasks in various imaging modalities. They demonstrate this approach in embryos with polycystic kidneys (pkd1 and pkd2) and craniofacial dysmorphia (six1). They provide a library of pre-trained networks and detailed instructions for applying deep learning to datasets and demonstrate the versatility, precision, and scalability of deep neural network phenotyping on embryonic disease models. Supported by ORIP (P40OD010997, R24OD030008), NICHD, NIDDK, and NIMH.
Negative Inotropic Mechanisms of β-cardiotoxin in Cardiomyocytes by Depression of Myofilament ATPase Activity without Activation of the Classical β-Adrenergic Pathway
Lertwanakarn et al., Scientific Reports. 2021.
https://www.nature.com/articles/s41598-021-00282-x
Beta-cardiotoxin (β-CTX) from the king cobra venom (Ophiophagus hannah) was previously proposed as a novel β-adrenergic blocker. However, the involvement of β-adrenergic signaling by this compound has never been elucidated. The objectives of this study were to investigate the underlying mechanisms of β-CTX as a β-blocker and its association with the β-adrenergic pathway. Healthy Sprague Dawley rats were used for cardiomyocytes isolation. In summary, the negative inotropic mechanism of β-CTX was discovered. β-CTX exhibits an atypical β-blocker mechanism. These properties of β-CTX may benefit in developing a novel agent aid to treat hypertrophic cardiomyopathy. Supported by ORIP (P40OD010960) and NHLBI.
MIC-Drop: A Platform for Large-scale In Vivo CRISPR Screens
Parvez et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/34413171/
CRISPR screens in animals are challenging because generating, validating, and keeping track of large numbers of mutant animals is prohibitive. These authors introduce Multiplexed Intermixed CRISPR Droplets (MIC-Drop), a platform combining droplet microfluidics, single-needle en masse CRISPR ribonucleoprotein injections, and DNA barcoding to enable large-scale functional genetic screens in zebrafish. In one application, they showed that MIC-Drop could identify small-molecule targets. Furthermore, in a MIC-Drop screen of 188 poorly characterized genes, they discovered several genes important for cardiac development and function. With the potential to scale to thousands of genes, MIC-Drop enables genome-scale reverse genetic screens in model organisms. Supported by ORIP (R24OD017870), NIGMS, and NHLBI.
Factor XII Plays a Pathogenic Role in Organ Failure and Death in Baboons Challenged with Staphylococcus aureus
Silasi et al., Blood. 2021.
https://pubmed.ncbi.nlm.nih.gov/33598692/
Activation of coagulation factor (F) XI promotes multiorgan failure in rodent models of sepsis and in a baboon model for lethal systemic inflammation induced by infusion of heat-inactivated Staphylococcus aureus. The authors used the anticoagulant FXII-neutralizing antibody 5C12 to verify the mechanistic role of FXII. Inhibition of FXII prevented fever, terminal hypotension, respiratory distress, and multiorgan failure. All animals receiving 5C12 had milder and transient clinical symptoms; untreated control animals suffered irreversible multiorgan failure. This study confirms their previous finding that at least two enzymes of FXIa and FXIIa play critical roles in the development of an acute and terminal inflammatory response. Supported by ORIP (P40OD024628), NIAID, NHLBI, and NIGMS.
Western-Style Diet Consumption Impairs Maternal Insulin Sensitivity and Glucose Metabolism During Pregnancy in a Japanese Macaque Model
Elsakr et al., Scientific Reports. 2021.
https://www.nature.com/articles/s41598-021-92464-w
Using a Japanese macaque model, investigators assessed the metabolic effects of obesity and a calorically dense, Western-style diet (WSD; 36.3% fat), either alone or together, on maternal glucose tolerance and insulin levels in dams during pregnancy (n = 95 females followed over multiple pregnancies [n = 273]). With prolonged WSD feeding, multiple diet switches, and/or increasing age and parity, WSD was associated with increasingly higher insulin levels during glucose tolerance testing, indicative of insulin resistance. The results suggest that prolonged or recurrent calorically dense WSD and/or increased parity, rather than obesity per se, drive excess insulin resistance and metabolic dysfunction. Supported by ORIP (P51OD011092), NIDDK and NIMH.
Mineralocorticoid Receptor Blockade Normalizes Coronary Resistance in Obese Swine Independent of Functional Alterations in Kv Channels
Goodwill et al., Basic Research in Cardiology. 2021.
https://pubmed.ncbi.nlm.nih.gov/34018061/
Impaired coronary microvascular function (e.g., reduced dilation and coronary flow reserve) predicts cardiac mortality in obesity. Mineralocorticoid receptor (MR) antagonism improves coronary microvascular function in obese humans and animals. Inhibition of Kv channels reduced coronary blood flow and augmented coronary resistance under baseline conditions in lean but not obese swine and had no impact on hypoxemic coronary vasodilation. MR blockade prevented obesity-associated coronary arteriolar stiffening independent of cardiac capillary density and changes in cardiac function. These data indicate that chronic MR inhibition prevents increased coronary resistance in obesity independent of Kv channel function and is associated with mitigation of obesity-mediated coronary arteriolar stiffening. Supported by ORIP (U42OD011140, S10OD023438), NHLBI, and NIBIB.
Cell-Specific Transcriptional Control of Mitochondrial Metabolism by TIF1γ Drives Erythropoiesis
Rossmann et al., Science. 2021.
https://pubmed.ncbi.nlm.nih.gov/33986176/
Transcription and metabolism both influence cell function but dedicated transcriptional control of metabolic pathways that regulate cell fate has rarely been defined. The authors discovered that inhibition of the pyrimidine biosynthesis enzyme dihydroorotate dehydrogenase (DHODH) rescues erythroid differentiation in bloodless zebrafish moonshine (mon) mutant embryos defective for transcriptional intermediary factor 1 gamma (tif1γ). Upon tif1γ loss, CoQ levels are reduced, and a high succinate/α-ketoglutarate ratio leads to increased histone methylation. A CoQ analog rescues mon's bloodless phenotype. These results demonstrate that mitochondrial metabolism is a key output of a lineage transcription factor that drives cell fate decisions in the early blood lineage. Supported by ORIP (R24OD017870), NIGMS, NHLBI, and NCI.
'Enhancing' Red Cell Fate Through Epigenetic Mechanisms
Rossmann and Zon et al., Current Opinion in Hematology. 2021.
https://pubmed.ncbi.nlm.nih.gov/33741760/
Transcription of erythroid-specific genes is regulated by the three-dimensional (3D) structure and composition of chromatin, which changes during erythroid differentiation. These authors address recent developments delineating the interface of chromatin regulation and erythroid-specific lineage transcription. They survey the erythroid chromatin landscape, erythroid enhancer-promotor interactions, super-enhancer functionality, the role of chromatin modifiers and epigenetic crosstalk, as well as the progress in mapping red blood cell (RBC) trait-associated genetic variants within cis-regulatory elements (CREs) identified in genome-wide association study (GWAS) efforts. New emerging technologies allow investigation of small cell numbers have advanced our understanding of chromatin dynamics during erythroid differentiation in vivo. Supported by ORIP (R24OD017870) and NHLBI.
Creb5 Establishes the Competence for Prg4 Expression in Articular Cartilage
Zhang et al., Communications Biology. 2021.
https://doi.org/10.1038/s42003-021-01857-0
Cells comprising the superficial zone of articular cartilage express lubricin, encoded by the Prg4 gene, that lubricates joints. Researchers identified Creb5 as a transcription factor that is required for TGF-β and EGFR signaling to induce Prg4 expression. Forced expression of Creb5 in deep-zone chondrocytes of articular cartilage confers competence for TGF-β and EGFR signals to induce Prg4 expression. The researchers showed that Creb5 directly binds to two Prg4 promoter-proximal regulatory elements, which work together with a more distal regulatory element to drive induction of Prg4 by TGF-β. Thus, Creb5 is a critical regulator of Prg4/lubricin expression in the articular cartilage. Supported by ORIP (U42OD11158), NIAMS, and NIDDK.