bluuebunny/crossref_metadata_2025_split huggingface dataset:
OR26-6 | LBMON298 The Role Of Nuclear Receptor Coregulator Grip1 In Homeostatic Programming Of Macrophages
Authors: Dacic Marija , Deochand Dinesh , Deochand Yurii , Rogatsky Inez 
Published: November 2022

Abstract
Aberrant macrophage function is implicated in acute and chronic inflammatory settings, and central to diseases such as obesity, atherosclerosis and cancer. However, the transcriptional and epigenomic programs driving macrophage polarization toward distinct phenotypic states are not well understood. Macrophage phenotypes exist on a spectrum, with pro-inflammatory (M1-like) and homeostatic, tissue repair (M2-like) states viewed as polar opposites and relatively stable. The main driver of the M2-like program is a type-2 cytokine, IL4 which signals to STAT6 followed by the Krüppel-like factor 4 (KLF4), a master regulator for numerous M2-specific genes. Reportedly, glucocorticoid (GC) hormones also promote the M2-like state, although the extent to which the phenotypes elicited by such disparate signals overlap is unknown. Interestingly, we discovered that GRIP1, a well-known cofactor for nuclear receptors including GR, serves as a KLF4 coactivator, suggesting that GRIP1 could mediate transcriptional and phenotypic convergence of the IL4- and GC-driven pathways. Gene expression profiling on differentially polarized macrophages revealed a highly significant overlap between M2IL4 and M2GC transcriptomes which was mirrored by the H3K27ac de novo enhancer landscape. Notably, loss of GRIP1 blunted both up-regulation of M2- and downregulation of M1-associated genes irrespective of the signal driving M2 polarization. At the cellular level, polarization with either IL4 or GCs enhanced macrophage phagocytosis relative to non-polarized M0, and did so in a GRIP1-dependent manner. Finally, in the dextran sulphate sodium (DSS)-induced colitis model of intestinal inflammation and tissue damage, GRIP1-cKO mice lacking GRIP1 in myeloid cells, including macrophages, displayed more severe destruction of the colonic mucosa and greater immune cell infiltration into the mucosa and submucosa. Moreover, in total colon RNA, the abundance of many characteristic M2 transcripts was reduced in the cKO mice. Surprisingly, the expression of proinflammatory mediators such as TNF, IL1b and IL23 was unaffected by GRIP1 deletion, suggesting that the more severe disease in the cKO stems primarily from the failure of M2-like resolving macrophage to efficiently mitigate tissue destruction and repair the damage. Together, these findings point to GRIP1 as a crucial regulator of macrophage polarization to the homeostatic state in vitro and in vivo.
Presentation: Monday, June 13, 2022 12:15 p.m. - 12:30 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
PMON285 Hypokalemic Periodic Paralysis: A Rare Presentation of Primary Hyperaldosteronism
Authors: Elsheikh Marwa , Robertson Anna-Belle , Lavine Ross , Abdelhadi Mahmoud , Rastogi Natasha 
Published: November 2022

Abstract

Background
Primary hyperaldosteronism (PHA) is caused by excessive production of aldosterone from the adrenal glands. Aldosterone levels are usually independent of renin, angiotensin II or sodium status, and often result in hypertension (HTN), hypokalemia and metabolic alkalosis. The most common presentation of this condition is with asymptomatic mild to severe or refractory HTN. This case highlights a patient presenting with hypokalemic periodic paralysis as the first sign of PHA.

Clinical Case
A 35 year old previously healthy Chinese male, presented with sudden onset bilateral lower extremity weakness for 1 day. This was associated with mild transient lower back pain and fatigue. He had no history of trauma, recent travel, exposure to animal or tick bites. He reported no recent illness or vaccination. His family history was negative for hypertension and various endocrinopathies. The patient was not on any medications and did not consume licorice.
His exam was significant for a blood pressure (BP) of 217/136 mmHg, with lower limb evaluation revealing power of 3/5, normal reflexes and a positive heel to shin test. He demonstrated an unsteady gait but Romberg's sign was negative. Upper limb exam was normal. Laboratory findings were remarkable for potassium 1.9 mmol/L, bicarbonate (CO2) 37 mmol/L, normal magnesium (Mg), normal TSH and blood gas showing metabolic alkalosis. Subsequent testing showed renin 0.35 ng/ml/hr, aldosterone 23 ng/dl and aldosterone/pra ratio 66. Saline infusion test confirmed the diagnosis of PHA. Other endocrinologic tests were normal. Electrocardiogram showed prolonged QT interval and U waves. Renal ultrasound was negative for renal artery stenosis and CT abdomen/pelvis showed a 2.4 cm left adrenal adenoma.
The patient was admitted to the intensive care unit for 24 hours, where he received intravenous potassium replacement and was started on spironolactone and other antihypertensive medications, which he was discharged on, along with oral potassium. His symptoms resolved after potassium levels normalized and he subsequently had a left adrenalectomy.

Conclusion
With PHA being the most common endocrinological cause of HTN, clinicians should recognize indicators of underlying PHA even in rare presentations such as this.
Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
PMON295 Investigating the ileal FXR/SHP axis in regulating lipid absorption and enterohepatic recirculation of bile acids
Authors: Nguyen James , Anakk Sayeepriyadarshini 
Published: November 2022

Abstract
Lipids are biological macromolecules essential for energy storage, signaling pathways, and cell structure. Majority of these molecules come from our diet where they are digested in the small intestine through their interaction with bile acids. Lipids break down into small molecules and are brought to the intestinal brush border to be absorbed passively by diffusion or by lipid transporters. Interestingly, two essential nuclear receptors that regulate both bile acid and lipid absorption and transportation are farnesnoid X receptor (FXR) and small heterodimer partner (SHP). Many studies have shown that the linear FXR/SHP axis controls these lipid metabolic processes, however, there are evidence indicating FXR-dependent and -independent pathways of SHP. In order to ascertain the importance of FXR and SHP in intestinal lipid metabolism, we utilized the following three mice models, intestine-specific Fxr (IFxrKO), intestine-specific Shp (IShpKO), and intestine-specific Fxr and Shp (IDKO) knockout models and challenged them with high fat diet. We are assessing the intestinal absorption and transportation of triglycerides by measuring the concentration of triglyceride on circulation, liver, and intestine and the molecular level the protein expression of different transporters. Parallelly, we will examine the bile acid pool by measuring bile acid levels from the intestine, liver, gall bladder, and serum to test if changes in bile acid circulation observed in these knockout models show different contribution towards lipid/triglyceride absorption. In addition, we will inject poloxamer-407 in these mice groups to assess their chylomicron secretion rate. Finally, we will examine the histology of the small intestine by performing H&E staining to examine the morphology and perform PAS/Alcian blue staining to examine mucus production.
Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
RF03 | PMON286 Engineering Steroid Receptors to Respond to Chemicals of Choice
Authors: Claessens Frank , Eerlings Roy , Gupta Purvi , Lee Xiao Yin , Kharraz Sarah E , Jacquemyn Maarten , Vandewinkel Bram , Munter Sofie D , Nguyen Tien , Handle Florian , Smeets Elien , Moris Lisa , Devlies Wout , Voordeckers Karin , Gorkovskiy Anton , Henckaerts Els , Daelemans Dirk , Verstrepen Kevin J , Voet Arnout , Helsen Christine 
Published: November 2022

Abstract
In synthetic biology, small molecules are commonly used for altering gene expression through the (in)activation of gene switches. Current switches, however, have a narrow species range, are non-titratable, or use non-inert inducers which evoke important side effects. Universal gene switches (XRs) that have dynamic ranges without interference with the host cell physiology will overcome these limitations. Ideal starting points for developing such XRs are the steroid receptors (SRs). The SRs are frequently applied as regulator domain or gene switch in organisms in which they are not naturally expressed, like microbes and plants. Several SRs, such as the estrogen receptor alpha (ERα), have been redesigned to respond to synthetic effectors but these variants require inducer amounts that are detrimental to the host or affect endogenous SRs.
By combining in silico modelling with directed evolution in the yeast Saccharomyces cerevisiae, we developed a platform and strategy for evolving SRs towards a chemical of choice. Validation of this method was achieved by first evolving the ERα to employ tamoxifen as an agonist, yielding the preTERRA variant. Subsequently, activation by estradiol was removed, rendering a tamoxifen receptor (TERRA). We show that TERRA gets activated by subtoxic tamoxifen amounts while remaining insensitive for physiological estradiol levels. Further evaluation demonstrated TERRA to be transferable to mammalian cells. Ongoing research aims at converting the TERRA receptor into a regulatory domain for controlling nuclear translocation of Cre recombinases and Cas9 proteins in both cell lines and mouse models.
The same platform was employed for adapting ERα towards the plasticizer Bisphenol A. This yielded an ERα variant that is no longer inducible by estradiol but is responsive to lower concentrations of Bisphenol in yeast. The transferal to cell lines will provide us with an additional regulatory domain. The ability to engineer any SR towards a synthetic ligand of choice not only expands the synthetic biology toolbox but can find applications in landscaping SR-related drug resistance and ligand-inducibility.
Presentation: Saturday, June 11, 2022 1:48 p.m. - 1:53 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
RF03 | PMON287 Examining the role of Constitutive Androstane Receptor during Imidacloprid exposure
Authors: Sen Anushna , Goforth Madison , Cooper Kerry , Anakk Sayeepriyadarshini 
Published: November 2022

Abstract
Imidacloprid (IMI) is a neonicotinoid pesticide used for pest control and seed treatments. It mimics nicotine and selectively targets insect nicotinic acetylcholine receptors to induce paralysis and death. Popularly used worldwide, IMI residue is readily detectable in crops, the environment, and human samples. Gastrointestinal symptoms in patients as well as defective gut barrier and hepatoxicity in animal models have been reported subsequent to IMI exposure. However, the mechanism underlying IMI toxicity in mammals is unclear. Pesticide exposure frequently activates xenobiotic nuclear receptors, like constitutive androstane receptor (CAR), to induce detoxification phase I and phase II genes. We found that IMI exposure in wild-type (WT) mice induced hepatic expression of Cyp2b10, a bona fide target of CAR. This data led us to investigate the role of CAR in alleviating IMI toxicity. We dosed wild-type (WT) and Car-/- mice with 50mg/kg BW IMI, twice daily for 21 days and collected serum, liver, and intestine tissues. The absence of CAR resulted in a three-fold increased accumulation of IMI within the liver as well as a 6% increase in body weight. Intriguingly, IMI exposure resulted in hepatic inflammatory pockets in WT mice but did not induce serum liver injury markers (ALT and AST) in either WT or Car-/- mice. We quantified the expression of genes involved in detoxification and oxidative stress within the liver and ileum using qRT-PCR. We found Car-/-mice had significantly blunted expression of Cyp-P450 enzymes in the ileum. To compare gut function, we measured organ coefficient and examined ileal histology using Alcian Blue/PAS staining. We found the absence of CAR altered small intestine (SI) morphology independent of IMI exposure suggesting a basal role of CAR in maintaining overall SI morphology. Car-/-mice also exhibited increased SI weight and length and shorter villi height. AB-PAS staining showed IMI reduced ileal mucin production in WT mice but not Car-/- mice. To further examine CAR's role in the xenobiotic metabolism in the ileum, we will compare microbial diversity and bile acid pools with and without IMI exposure. Our results suggest IMI is not overtly toxic, but the absence of xenobiotic nuclear receptor CAR allows increased accumulation of IMI in the liver and disrupts the structure and Cyp gene expression in the intestine.
Presentation: Saturday, June 11, 2022 1:18 p.m. - 1:23 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
RF03 | PMON303 Serum 25-Hydroxyvitamin D Concentration Significantly Decreases in COVID-19 Patients With Pneumonia During the First 48 Hours After Hospital Admission
Authors: Smaha Juraj , KuÅma Martin , Nachtmann Samuel , Jackuliak Peter , Max Filip , Tibenskã Elena , Binkley Neil , Payer Juraj 
Published: November 2022

Abstract

Objectives
Although 25(OH)D is generally considered the best marker for assessing vitamin D body stores, its role as a marker during acute illness is less well established. Indeed, acute inflammatory insult may reduce circulating 25(OH)D. The objective was to examine serum 25(OH)D levels during the evolution of acute COVID-19 pneumonia.
Material and methods: This pilot study was undertaken as a prospective cohort study. Patients with severe COVID-19, defined as clinical signs of pneumonia and respiratory rate &gt; 30 breaths/minute or severe respiratory distress or oxygen saturation &lt; 90% on room air, were admitted to the internal medicine department between 1 November and 31 December. Blood samples were taken on admission (day 0) and every 24 hours for the subsequent four days (days 1-4). Patients were not supplemented with vitamin D preparations during the monitoring period. All patients received 6 milligrams of dexamethasone daily during the monitoring period.

Results
22 patients (6 females, 16 males; median age 60.6 years) were included. On admission, 59% of patients were 25(OH)D sufficient (&gt;30 ng/ml), and 41% of patients had 25(OH)D inadequacy (&lt;30 ng/ml) according to the existing guidelines. A significant fall in mean 25(OH)D concentration from admission to day 2 (first 48 h) was observed (30,7 ng/ml vs. 26,4 ng/ml; p&lt;0.0001). No subsequent significant fall in 25(OH)D concentration was observed between day 2 and 3 (26, 4 ng/ml vs. 25,9 ng/ml; p=0.2300) and day 3 and day 4 (25,8 ng/ml vs. 25,9 ng/ml; p=0.7026). The absolute 25(OH)D change between hospital admission and day 4 was 4.8 ng/mL (p&lt;0.0001) and was not associated with mortality or the need for high flow oxygen (p=0.2113 and p=0.6467, respectively). On day 4, the number of patients with 25(OH)D inadequacy (&lt;30 ng/ml) increased by 18% (p=0.0180).

Conclusions
Serum concentration of 25(OH)D decreases significantly during the first 48 hours after hospital admission in acutely ill COVID-19 patients and should be therefore interpreted with caution. Whether low 25(OH)D in COVID-19 reflects tissue level vitamin D deficiency or represents only a laboratory phenomenon remains to be elucidated in prospective randomized trials of vitamin D supplementation.
Presentation: Saturday, June 11, 2022 1:30 p.m. - 1:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
RF15 | PMON291 Crystal Structures of Androgen DNA Binding Domain Interacting with its Response Elements (C3(1) ARE and MMTV-GRE)
Authors: Claessens Frank , Yin Lee Xiao , Helsen Christine , Voet Arnout 
Published: November 2022

Abstract
Prostate cancer (PCa) is the second leading cancer in the world in men. The major therapeutic target in advanced PCa is the ligand-binding pocket (LBP) of the androgen receptor (AR). The anti-androgens used to treat cancer are binding to this domain and compete with the natural agonist. Over time the cancer grows resistant towards this therapy. Nevertheless, the cancer still typically depends on the AR, indicating other sites of the AR may still serve as drug targets. The DNA binding domain (DBD) is a likely good therapeutic target as it is involved in essential processes such AR dimerization, translocation to the nucleus and binding to the androgen response elements (AREs). However the structure and the DNA binding interactions with AREs are not fully explored yet. Only one crystal structure (pdb: 1R4I) is available. In this structure, the DBD is bound to an artificial direct repeat DNA sequences (ADR3), resulting in an unexpected dimeric head-to-head arrangement. A better understanding on how the AR recognizes and binds to different native DNA sequences which are mainly organized as semi inverted repeats is crucial for rational drug design. Here, we performed protein crystallography of the DBD in complex with various natural ARE sequences, including the mouse mammary tumour virus (MMTV-GRE) motif. Surprisingly, this latter element is still able to be activated by a dimerization deficient AR.
Our first crystal structures were hallmarked by a high degree of disorder and appeared to bind both in a head-to-head as a head-to-tail fashion. Rational engineering of the DNA duplexes used for crystallography yielded well diffracting crystals for two different complexes. These two structures were diffracted to a range of 2 to 2.7 Å. Both structures with natural sequences appeared to bind in the head-to-head arrangement including the MMTV-GRE which consist out of semi inverted repeat DNA, whereas the C3(1)ARE contains the canonical fully inverted repeats. The structure reveals a slightly bend arrangement from the previously reported structure. The displacement is most visible at the DNA recognition helix bound to the half site and the so-called lever arm, which positions this helix in this region with a RMSD difference of 1.3 A. This indicates that the structural conformation changes of the protein is driven towards improved DNA-base pair recognition. Indeed the protein is able to make an additional set of non-covalent interactions with the base pairs of MMTV-GRE, leading to higher affinity. Both these extra interactions and conformational change lead to a higher affinity binding of protein-DNA, which seems to overcome the barrier introduced by the dimerization breaking mutations. This interaction surface could be a druggable site for structure-based drug design in the future, targeting AR-DBD dimerization.
Presentation: Sunday, June 12, 2022 12:30 p.m. - 12:35 p.m., Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.
LBODP100 A Rare Case Of Pembrolizumab Induced Graves’ Disease
Authors: Alqaisi Sura , Rahman Ali 
Published: November 2022

Abstract
Cancer immunotherapies have recently changed the therapeutic armamentarium of anti-cancer treatments, particularly for melanoma and cancers of the kidneys, lungs, and colon. Immune checkpoint inhibitors (ICPis) act on various immune checkpoints. Of them, anti-PD-1 antibodies (such as pembrolizumab) are monoclonal antibodies that act against programmed cell death 1 protein. However, by counteracting the regulators of adaptive immunity, this class of drugs may cause immune-related adverse events that involve multiple organs and endocrine glands, such as the thyroid gland. The symptoms of thyroid dysfunction usually present during the first weeks of ICPis therapy. In the current report, we present a case of a 50-year-old male who presented to the emergency department complaining of fever, chills, nausea, and vomiting for one week. The patient had a history of colon cancer with lymph node metastasis status post tumor resection and colostomy. He began Keytruda® (pembrolizumab) treatment after tumor resection, and the presenting symptoms appeared after receiving the first immunotherapy infusion. His medical history was significant for psoriasis and rheumatoid arthritis. The patient's history was unremarkable for thyroid diseases, and he did not receive thyroid medications with no previous exposure to intravenous contrast media, over-the-counter iodine preparations, or biotin. At the emergency department, the patient had a temperature of 101.4°F, a heart rate of 110 bpm, and blood pressure of 130/70 mm Hg. On examination, tenderness was indicated upon palpating the anterior part of the neck. The patient was treated with intravenous fluids, steroids, beta-blockers, and broad-spectrum antibiotics. A workup for sepsis was requested, and it revealed negative blood culture and urine culture results. His laboratory indices demonstrated a suppressed level of TSH (0. 01 mIU/mL) and elevated Free T4 (3.16 ng/dl). Still, his TSH level reported at the Oncology clinic before Keytruda administration was (0.9 mIU/mL), and Free T4 was (1.7 ng/dl). Thyroid ultrasound revealed a heterogeneous thyroid gland consistent with thyroiditis. Antibody testing showed positive thyroid antithyroglobulin antibodies and elevated thyroid-stimulating antibodies (TSI). A radioactive iodine uptake test was ordered, revealing increased contrast uptake. These findings suggested that the cause of thyroid dysfunction was Graves’ disease. The patient was started on Methimazole 20mg per day and discharged home after scheduling an outpatient follow-up appointment with the endocrinologist. This case is one of the rare cases of thyrotoxicosis attributable to Graves’ disease related to pembrolizumab therapy. To the best of our knowledge, two studies in the literature reported three cases of ICPi-induced thyrotoxicosis with thyroid antibody positivity following anti-PD-1 antibody therapy.
Presentation: No date and time listed