Showing papers by "David Spiegel published in 2021"

Bifunctional small molecules that mediate the degradation of extracellular proteins.

Abstract: Targeted protein degradation (TPD) has emerged as a promising therapeutic strategy. Most TPD technologies use the ubiquitin-proteasome system, and are therefore limited to targeting intracellular proteins. To address this limitation, we developed a class of modular, bifunctional synthetic molecules called MoDE-As (molecular degraders of extracellular proteins through the asialoglycoprotein receptor (ASGPR)), which mediate the degradation of extracellular proteins. MoDE-A molecules mediate the formation of a ternary complex between a target protein and ASGPR on hepatocytes. The target protein is then endocytosed and degraded by lysosomal proteases. We demonstrated the modularity of the MoDE-A technology by synthesizing molecules that induce depletion of both antibody and proinflammatory cytokine proteins. These data show experimental evidence that nonproteinogenic, synthetic molecules can enable TPD of extracellular proteins in vitro and in vivo. We believe that TPD mediated by the MoDE-A technology will have widespread applications for disease treatment.

The risk of medically uncontrolled secondary hyperparathyroidism depends on parathyroid hormone levels at haemodialysis initiation.

Abstract: Background Optimal parathyroid hormone (PTH) control during non-dialysis chronic kidney disease (ND-CKD) might decrease the subsequent risk of parathyroid hyperplasia and uncontrolled secondary hyperparathyroidism (SHPT) on dialysis. However, the evidence for recommending PTH targets and therapeutic strategies is weak for ND-CKD. We evaluated the patient characteristics, treatment patterns and PTH control over the first year of haemodialysis (HD) by PTH prior to HD initiation. Methods We studied 5683 incident HD patients from 21 countries in Dialysis Outcomes and Practice Patterns Study Phases 4-6 (2009-18). We stratified by PTH measured immediately prior to HD initiation and reported the monthly prescription prevalence of active vitamin D and calcimimetics over the first year of HD and risk of PTH >600 pg/mL after 9-12 months on HD. Results The 16% of patients with PTH >600 pg/mL prior to HD initiation were more likely to be prescribed active vitamin D and calcimimetics during the first year of HD. The prevalence of PTH >600 pg/mL 9-12 months after start of HD was greater for patients who initiated HD with PTH >600 (29%) versus 150-300 (7%) pg/mL (adjusted risk difference: 19%; 95% confidence interval : 15%, 23%). The patients with sustained PTH >600 pg/mL after 9-12 months on HD were younger, more likely to be black, and had higher serum phosphorus and estimated glomerular filtration rates at HD initiation. Conclusions Increased PTH before HD start predicted a higher PTH level 9-12 months later, despite greater use of active vitamin D and calcimimetics. More targeted PTH control during ND-CKD may influence outcomes during HD, raising the need for PTH target guidelines in these patients.

Sirtuin 2 Regulates Protein LactoylLys Modifications.

Abstract: Post-translational modifications (PTMs) play roles in both physiological and pathophysiological processes through the regulation of enzyme structure and function. We recently identified a novel PTM, lactoylLys, derived through a nonenzymatic mechanism from the glycolytic by-product, lactoylglutathione. Under physiologic scenarios, glyoxalase 2 prevents the accumulation of lactoylglutathione and thus lactoylLys modifications. What dictates the site-specificity and abundance of lactoylLys PTMs, however, remains unknown. Here, we report sirtuin 2 as a lactoylLys eraser. Using chemical biology and CRISPR-Cas9, we show that SIRT2 controls the abundance of this PTM both globally and on chromatin. These results address a major gap in our understanding of how nonenzymatic PTMs are regulated and controlled.

Classically activated mouse macrophages produce methylglyoxal that induces a TLR4- and RAGE-independent proinflammatory response.

Abstract: The highly reactive compound methylglyoxal (MG) can cause direct damage to cells and tissues by reacting with cellular macromolecules. MG has been identified as a biomarker associated with increased sepsis-induced mortality. Patients undergoing septic shock have significantly elevated circulating MG levels compared to postoperative patients and healthy controls. Furthermore, MG has been implicated in the development of type II diabetes mellitus and Alzheimer's disease. Because MG is generated during glycolysis, we hypothesized that MG may be produced by classically activated (M1) macrophages, possibly contributing to the inflammatory response. LPS and IFN-γ-treated macrophages acquired an M1 phenotype (as evidenced by M1 markers and enhanced glycolysis) and formed MG adducts, MG-H1, MG-H2, and MG-H3, which were detected using antibodies specific for MG-modified proteins (methylglyoxal 5-hydro-5-methylimidazolones). MG adducts were also increased in the lungs of LPS-treated mice. Macrophages treated with LPS and IFN-γ also exhibited decreased expression of glyoxalase 1 (Glo1), an enzyme that metabolizes MG. Concentrations of exogenous, purified MG > 0.5 mM were toxic to macrophages; however, a nontoxic dose of 0.3 mM induced TNF-α and IL-1β, albeit to a lesser extent than LPS stimulation. Despite prior evidence that MG adducts may signal through "receptor for advanced glycation endproducts" (RAGE), MG-mediated cell death and cytokine induction by exogenous MG was RAGE-independent in primary macrophages. Finally, RAGE-deficient mice did not exhibit a significant survival advantage following lethal LPS injection. Overall, our evidence suggests that MG may be produced by M1 macrophages during sepsis, following IFN-γ-dependent down-regulation of Glo1, contributing to over-exuberant inflammation.

The Hypnotic Induction Profile (HIP) in Clinical Practice and Research.

Abstract: The Hypnotic Induction Profile (HIP) was developed as a brief, yet thorough, assessment of a person’s level of trait hypnotizability and their potential to experience a hypnotic state. The HIP quan...

Outcomes After Surgical Fixation of Posterior Sternoclavicular Physeal Fractures and Dislocations in Children.

Abstract: Background Acute sternoclavicular fractures and dislocations (SCFDs) are a rare but important injury in pediatric patients. SCFDs are either true dislocations, or more commonly, physeal fractures in children. The reduction is advised given the proximity to surrounding vascular structures, and some authors advocate for routine fixation given rates of redisplacement after closed reduction. The purpose of the current study was to provide validated long-term functional outcome data following open reduction and surgical fixation of pediatric SCFDs, as well as provide injury and demographic information. Methods This is a retrospective observational study with a subset of patients reporting functional outcomes. Patients under the age of 18 that had surgically managed acute posterior SCFD from 1990 to 2018 were included. A retrospective chart review was performed to obtain demographic, clinical, and surgical details. Patients with a minimum of 6-month follow-up were contacted to assess outcomes. Functional outcomes of interest included QuickDash, Visual Analog Scale pain rating, Single Assessment Numeric Evaluation of shoulder function, and PROMIS Upper Extremity questionnaire. Statistical analysis included descriptive statistics. Results A total of 37 patients that sustained an acute posterior SCFD during the study period were included. The average age at the time of injury was 15.2±2.1 years and 89% were male. Patient-reported outcomes were obtained for 14 patients with a mean follow-up of 4.5 years. The mean QuickDash score was 5.1/100 with 0 being normal, and the mean Visual Analog Scale pain rating was 0.7/10. The mean Single Assessment Numeric Evaluation score was 96% with 100% being completely normal. The mean PROMIS score was 55 with 50 being the mean of the relevant reference population. Approximately 29% (4/14 patients) stated that their injury negatively affected their ability to participate in sports. Conclusions There is a paucity of literature on functional outcomes after surgical management of pediatric acute posterior SCFD. Functional outcomes after surgery were satisfactory in this cohort with most patients being able to perform major activities of daily living. Additional future studies with larger cohorts and comparative groups are needed to better understand outcomes in this population. Level of evidence Level IV.

Testing Hypnotizability by Phone: Development and Validation of the Remote Hypnotic Induction Profile (rHIP)

Abstract: Standard hypnotizability scales require physical contact or direct observation by tester and participant. The authors addressed this limitation by developing and testing the remote Hypnotic Inducti...

When Physicians Engage in Practices That Threaten the Nation's Health.

Abstract: This Viewpoint proposes response options for specialty societies, medical licensing boards, academic leadership, and faculty and colleagues when physician public health leaders spread misinformation detrimental to patients' or the public's health, as happened in the first year of the COVID-19 pandemic

Shared cognitive mechanisms of hypnotizability with executive functioning and information salience.

Abstract: In recent years, evidence linked hypnotizability to the executive control and information salience networks, brain structures that play a role in cognitive conflict resolution and perseveration (insisting on applying a previously learned logical rule on a new set). Despite the growing body of neuroimaging evidence, the cognitive phenotype of hypnotizability is not well understood. We hypothesized that higher hypnotizability would correspond to lower perseveration and set-shifting. Seventy-two healthy adults were tested for hypnotizability and executive functions (perseveration and set-shifting). Multiple regression analyses were performed to test the relationship between hypnotizability and perseveration and set-shifting. Higher hypnotizability was associated with lower perseveration after accounting for age and education. Hypnotizability significantly predicted perseveration but not set-shifting. Our results indicate an inverse relationship between trait hypnotizability and perseveration, an executive function that utilizes regions of both the executive control and the salience systems. This suggests that hypnotizability may share a common cognitive mechanism with error evaluation and implementation of logical rules.

Real-Time Semi-Automated and Automated Voxel Placement for Repeated Acquisition Magnetic Resonance Spectroscopy

Abstract: Magnetic resonance spectroscopy (MRS) is heavily dependent on the investigative team to prescribe, or demarcate, the desired tissue volume-of-interest. Manual prescription, the current standard in the field, requires expertise in neuroanatomy to ensure spatial consistency within and across subjects. Spatial precision of MRS voxel placement thus presents challenges for cross-sectional studies, and even more so for repeated-measure and multi-acquisition designs. Furthermore, voxel prescriptions based-solely on anatomical landmarks may not be ideal in regions with substantial functional and cytoarchitectural variability or to examine individualized/targeted interventions. Here we propose and validate robust and real-time methods to automate MRS voxel placement using functionally defined coordinates within the left dorsolateral prefrontal cortex in clinical cohorts of chronic pain and depression. We hypothesized that increased automation would produce more consistent voxel placement across repeated acquisitions particularly in reference to standard manual prescription. Data were collected and analyzed using two independent prospective transcranial magnetic stimulation studies: 1) a single-day multi-session sandwich design and 2) a longitudinal design. Participants with fibromyalgia syndrome (N=50) and major depressive disorder (N=35) underwent MRI as part of ongoing clinical studies. MEGA-PRESS and Optimized-PRESS MRS acquisitions were acquired at 3-tesla. Evaluation of the reproducibility of spatial location and tissue segmentation was assessed for: 1) manual, 2) semi-automated, and 3) automated voxel prescription approaches. Variability of grey and white matter voxel tissue composition was reduced using automated placement protocols as confirmed by common MRS software processing pipelines (Gannet; SPM-based segmentation) and via Freesurfer-based segmentation. Spatially, post-to pre-voxel center-of-gravity distance was reduced and voxel overlap increased significantly across datasets using automated compared to manual procedures. These results demonstrate the within subject reliability and reproducibility of a method for reducing variability introduced by spatial inconsistencies during MRS acquisitions. The proposed method is a meaningful advance toward improved consistency of MRS data in neuroscience and can be leveraged for multi-session and longitudinal studies that target precisely defined regions-of-interest via a coordinate-based approach.

Posthypnotic Amnesia in Hypnotizability Assessment: Validation of a New Scoring System for the Hypnotic Induction Profile

Abstract: The Hypnotic Induction Profile (HIP) is a standardized assessment of hypnotizability featuring a validated 0–10 scoring system, that does not factor in posthypnotic amnesia. Using confirmatory fact...

Modulation of a Stable Neurobehavioral Trait Using Repetitive Transcranial Magnetic Stimulation: A Preregistered Randomized Controlled Trial

Abstract: Hypnotizability, one9s ability to experience cognitive, emotional, behavioral, and physical changes in response to suggestions in the context of hypnosis, is a highly stable trait associated with increased functional connectivity between the left dorsolateral prefrontal cortex (L-DLPFC) and dorsal anterior cingulate cortex (dACC). We conducted a preregistered, triple-blinded, randomized controlled trial to test the ability of continuous theta-burst stimulation (cTBS) over a personalized neuroimaging-based L-DLPFC target to temporarily enhance hypnotizability. We tested our hypothesis in 78 patients with fibromyalgia syndrome (FMS), a functional pain disorder for which hypnosis has consistently been shown to be beneficial as a nonpharmacological treatment option. Pre-to-post cTBS change in Hypnotic Induction Profile scores (HIP; a standardized measure of hypnotizability) was significantly greater in the Active versus Sham group. Our findings suggest a causal relationship between L-DLPFC and dACC function and hypnotizability. Dose-response optimization should be further examined to formalize guidelines for future clinical utilization.

Does nutrition consultation in the year leading up to neuromuscular scoliosis surgery result in significant weight gain, or just a larger magnitude curve?

Abstract: PURPOSE Patients with neuromuscular scoliosis undergoing posterior instrumented spinal fusion can be underweight, malnourished, and have higher complication rates. A nutrition consult is common in this population and it is unclear if weight gain occurs from the consult or surgery. The purpose of the study was to determine if nutrition consultation in the year prior to spinal fusion resulted in significant differences in weight gain or percentile on the CP growth chart. The secondary aim was to determine if there would be deformity progression during that time. METHODS Retrospective chart and radiograph review was performed for all patients with neuromuscular spinal deformity treated with posterior instrumented spinal fusion at one institution between January 1, 2009 and August 1, 2015. Inclusion criteria included < 20 years old, diagnosis of neuromuscular scoliosis, and 1-year pre-operative percentile on the CP growth chart < 50. Patient demographics, GMFCS level, weight, percentile on appropriate CP growth chart, major curve and pelvic obliquity at 1 year pre-operatively and at surgery were recorded. RESULTS Sixty-eight patients met inclusion criteria. Thirty-seven patients had a nutrition appointment within 1 year pre-operatively, 31 patients did not. There were no significant differences between the groups when comparing increase in weight (p = 0.9), percentile on CP growth charts (p = 0.3), major deformity (p = 0.1), and pelvic obliquity (p = 0.2). Overall, there was a mean 3.2 kg weight gain, 5.2% increase on CP growth charts, 40° increase in major curve, and 5° worsening of pelvic obliquity in the year before surgery. There was an average overall increase in the pre-operative albumin value, but this was not different between groups (p = 0.6). Children who were tube fed gained on average 10.8 percentiles on the CP growth chart, whereas children without gained only 0.5 percentiles (p = 0.002). CONCLUSIONS Nutrition consultations in the year preceding posterior instrumented spinal fusion do not lead to weight optimization prior to surgery in comparison to patients without nutrition consults. Gastrostomy tubes were found to be helpful for weight optimization and should be considered as an alternative nutrition option in pre-operative planning in underweight patients. LEVEL OF EVIDENCE III-therapeutic study: retrospective comparative study.

Impact of assessment frequency of patient-reported outcomes: an observational study using an eHealth platform in cancer patients

Abstract: The evaluation of patient-reported outcomes (PRO) in cancer has proven relevant positive clinical impact on patients’ communication with healthcare professionals, decision-making for management, well-being, and overall survival. However, the optimal frequency of PRO assessment has yet to be defined. Based on the assumption that more frequent sampling would enhance accuracy, we aimed at identifying the optimal sampling frequency that does not miss clinically relevant insight. We used pilot data from 31 advanced cancer patients who completed once daily the 19-item MD Anderson Symptom Inventory at home. The resulting dataset allowed us to compare different PRO assessment frequencies to daily sampling, i.e., alternate days (q2d), every third day (q3d), or once a week (q1w). We evaluated the sampling frequencies for two main outcomes: average symptom intensity and identification of severe symptoms. The majority of the differences between corresponding averages of daily data and those for q2d, q3d, and q1w datasets were close to 0, yet the extremes exceeded 5. Clinically meaningful differences, i.e., > 1, were observed in 0.76% of patient items for q2d, in 2.72% for q3d, and in 11.93% for q1w. Moreover, median values of missed instances of a severe symptom (i.e., > 6) were 14.6% for q2d, 27.8% for q3d, and 55.6% for q1w. Our analysis suggests that in patients receiving chemotherapy for advanced cancer, increasing the density of PRO collection enhances the accuracy of PRO assessment to a clinically meaningful extent. This is valid for both computations of averages symptom burden and for the recognition of episodes of severe symptom intensity.

RAGE antagonist peptide mitigates AGE-mediated endothelial hyperpermeability and accumulation of glycoxidation products in human ascending aortas and in a murine model of aortic aneurysm

Abstract: Background: Aortic dissection and aneurysm are the result of altered biomechanical forces associated with structural weakening of the aortic wall caused by genetic or acquired factors. Current guidelines recommend replacement of the ascending aorta when the diameter is >5.5 cm in tricuspid aortic valve patients. Aortopathies are associated with altered wall stress and stiffness as well as endothelial cell dysfunction and synthetic vascular smooth muscle cell (VSMC) phenotype. We reported that these mechanisms are mediated by glycoxidation products [Reactive oxygen species (ROS) and Advance Glycation End products (AGE)]. This study addresses the role of glycoxidation on endothelial function and AGE-mediated aortic stiffness. Hypothesis and aims: Here we investigate how circulating glycation products infiltrate the aortic wall via AGE-mediated endothelial hyperpermeability and contribute to both VSMC synthetic phenotype and extracellular matrix (ECM) remodeling in vivo and ex vivo. We also study how RAGE antagonist peptide (RAP) can rescue the effect of AGEs in vitro and in vivo in eNOS-/- vs WT mice. Methods and results: Human ascending aortas (n=30) were analyzed for AGE, ROS, and ECM markers. In vitro glycation was obtained by treating VSMC or human and murine aortas with glyoxal. Endothelial permeability was measured under glycation treatment. Vascular stiffness was measured by a pressure myograph comparing wild-type mice in the absence of presence of glyoxal. eNOS-/- mice, a model of increased endothelial permeability, were treated for 28 days with hyperlipidemic diet and Angiotensin II (1000ng/kg/min) with or without anti-glycation treatment (RAP 20mg/kg). Echo data of aortic diameter were collected. Murine vascular stiffness was measured by a pressure myograph (n=5/group). Glycoxidation products were detected in all human aortas independently of aortic diameter, with stronger accumulation on the lumen and the adventitia layer. AGEs increased endothelial permeability, induce synthetic phenotypic switch in human VSMCs, and inhibit cell migration. RAP pre-treatment rescue the effect of glyoxal on endothelial cells. Ex vivo glycation treatment of murine arteries impacted on ECM and increased stiffness. Aortic stiffness was higher in eNOS-/- vs WT mice. Ang II-mediated aortopathies results in aortic dilation, and AGE/ROS accumulation, which is rescued by RAGE antagonist peptide treatment of eNOS-/- mice. Conclusions: Glycoxidation reaction mediates EC permeability, VSMCs phenotype, and ECM remodeling leading to dysfunctional microstructure of the ascending aorta, altered vascular stiffness and increasing aortic susceptibility to dilation and rupture. Moreover, we show that RAP can mitigate AGE-mediated endothelial hyper-permeability in vitro and impact on ascending aneurysm in vivo

Altered Neurotransmitter Ratio in the Prefrontal Cortex is Associated with Pain in Fibromyalgia Syndrome

Abstract: The central mechanisms underlying fibromyalgia syndrome (FMS) remain undetermined. The dorsolateral prefrontal cortex (DLPFC) is particularly relevant to FMS because it is implicated in cognitive, affective, and top-down pain regulation. Imbalances in excitatory (Glutamate) and inhibitory (Gamma aminobutyric acid; GABA) neurochemicals may play a critical role in the pathophysiology of the condition and more generally in homeostatic function within cortical circuits. Although the balance of excitation and inhibition are intrinsically linked no investigations to date have investigated the E/I ratio in FMS. Thus, the primary objective of this study was to determine whether the E/I ratio in the DLPFC is altered in participants with FMS compared to healthy controls using magnetic resonance spectroscopy. Additionally, we examined the relationship between E/I ratio and pain metrics. We hypothesized that the E/I ratio within the DLPFC would be altered in participants with FMS compared to controls and, secondly, that E/I ratio would be associated with both clinical pain and thermal pain sensitivity. The Brief Pain Inventory (BPI) self-assessment was used to evaluate pain severity and impact on physical functioning and acute pain sensitivity was determined via quantitative sensory testing to define thermal (heat) pain threshold and tolerance. Our results revealed an elevation in the E/I ratio in FMS compared to controls. A positive relationship between E/I ratio and thermal pain sensitivity measures was identified in the FMS cohort. Collapsing across groups, there was a positive relationship between E/I ratio and BPI score. These findings suggest that dysfunction in the balance between excitation and inhibition within cognitive brain circuitry may play a role in pain processing in FMS.

Directed conjugation technologies

Abstract: Among other things, the present disclosure provides technologies for site-directed conjugation of various moieties of interest to target agents. In some embodiments, the present disclosure utilizes target binding moieties to provide high conjugation efficiency and selectivity. In some embodiments, provided technologies are useful for preparing antibody conjugates.