Regulation of Human NK Cell Activation by Expression of HLA Class I Molecules in Pig Endothelial Cells

Background: Pig-to-human xenotransplantation (XTx) is a promising solution to the organ shortage. Genetically engineered pigs lacking major xenoantigens have reduced hyperacute rejection and prolonged xenograft survival. Despite these advancements, acute xenograft rejection (AXR) remains a major barrier to clinical XTx. AXR is mediated by multiple immune cells, of which natural killer (NK) cells play a crucial role. Previous studies have shown that human HLA-E suppresses NK cell activation through the inhibitory receptor NKG2A. We seek to improve pig-to-human compatibility by expressing HLA-E in a genetically modified pig endothelial cell (pEC) line. This cell line 5GKO/ HLA-G+ has mutations in five genes encoding for xenoantigens and expresses HLA-G, an inhibitory ligand of the NK cell receptor KIR2DL4. In this study, the 5GKO/HLA-G+/HLA-E+ pEC line was established to examine whether co-expression of inhibitory ligands promotes NK cell tolerance. Methods: The HLA-Eα/pCDNA3.1 plasmid containing the HLA-E α-chain (HLA-Eα) cDNA driven by a CMV promoter was linearized and introduced into 106 cells of the 5GKO/HLA-G+ pEC line by electroporation. After 48 hours, HLA-E expression was analyzed by flow cytometry. HLA-E+ pECs were isolated by flow cytometry sort and co-cultured with human peripheral blood mononuclear cells (PBMCs) stimulated by IL-2. NK cell degranulation was compared between the 5GKO/HLA-G+ and 5GKO/HLA-G+/HLA-E+ pEC lines by measuring CD107a expression in the CD3- CD56+ cell population. Results: HLA-E molecules were successfully expressed on the pECs surface, indicating the HLA-E a chain can pair with the existing b2-microglobulin (B2M). The transfection efficiency was 38.2%. Three weeks later, the 5GKO/HLA-G+/HLA-E+ pEC was successfully established, confirming via flow cytometric analysis. The analysis of NK cell degranulation (CD107a) is underway. Conclusion: We established a 5GKO/HLA-G+/HLA-E+ pEC line, which is a valuable tool to study human-to-pig xenoreactive immune response in vitro, with the goal of improving pig-to-human xenograft immunotolerance.

Role of MicroRNA-134-5p in Metabolic Syndrome-Associated Pulmonary Hypertension in Heart Failure with Preserved Ejection Fraction

Background: Pulmonary hypertension in heart failure with preserved ejection fraction (PH-HFpEF) is the most common cause of PH worldwide. It is closely linked to risk factors for metabolic syndrome, including obesity and diabetes - factors known to increase proliferation and migration of pulmonary artery smooth muscle cells (PASMCs), leading to pulmonary vascular remodeling. Qualitative studies have shown that patients with progressive vascular abnormalities develop more severe symptoms and suffer frequent hospitalization. However, underlying mechanisms involved in the regulation of pulmonary vascular remodeling in metabolic syndrome-associated PH-HFpEF are still unclear. Aim: We have recently observed decreased levels of the tumor suppressor WW domain-containing oxidoreductase (WWOX), which plays a housekeeping role in repressing cellular proliferation, in PASMCs isolated from rats with experimental PH-HFpEF and human subjects with obesity and diabetes. As microRNAs (miRNAs) have been shown to regulate WWOX expression in cancers, here we aimed at examining the involvement of miRNAs in WWOX-associated pulmonary vasculature regulation in metabolic syndrome-associated PH-HFpEF. Methods and Results: Among miRNAs that have been associated with reduced WWOX expression, including miR -134-5p, -153-3p, -29a-3b, -29b-3p and -187-5p, we found that miR-134-5p was significantly increased in PASMCs of obese and diabetic subjects. To determine the role of miR-134-5p in the regulation of WWOX in the pulmonary vasculature, we applied exogenous miR-134-5p to human PASMCs. Treatment with miR-134-5p decreased WWOX expression, increased PCNA expression (a cell proliferation marker) and enhanced cellular proliferation. Additionally, human PASMCs challenged with high concentration of glucose, palmitic acid and insulin, which mimic hyperglycemic, hyperlipidemic and hyperinsulinemic conditions, exhibited increased miR-134-5p, accompanied by elevated cellular proliferation. Conclusions: These studies suggest that miR-134-5p may have a potential role in metabolic syndrome-associated PH-HFpEF through regulating WWOX in the pulmonary vasculature. These studies identify miR-134-5p as a potential therapeutic target for the treatment of metabolic syndrome-associated PH-HFpEF. This project was funded, in part, with support from the NIH NHLBI Short-Term Training Program in Biomedical Sciences Grant funded, in part by T35HL110854 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Novel Fracture Site Targeting Drug Improves Fracture Healing with Pain Relief: Preclinical Evaluation of MAK123

Non-union bone fracture occurs in 5-10% of fracture injuries. Interventions include surgery with local implantation of autograft, allograft, demineralized bone matrix, and/or bone morphogenetic proteins. These types of fracture injuries are also accompanied by acute and chronic pain states. In most instances, opioids are provided to injured patients during and after surgery. With the opioid crisis, identifying new analgesic therapies that could reduce or eliminate opioid use, while also improving bone healing is important. Here we show the ability of a novel compound, MAK123, to both enhance bone healing and reduce pain behavior in a surgically induced femoral fracture mouse model. Briefly, 20 male C57BL/6 mice underwent a surgically induced femoral fracture and then were treated with 0, 2, 6, or 20 mg/kg, 3X/week for the 3 week study duration. Weekly X-rays were used to examine healing progression. Prior to euthanasia, mice underwent behavioral testing to measure evoked pain behaviors. Upon euthanasia, ex vivo µCT imaging and analysis was completed to assess fracture callus size and composition. While all doses of MAK123 tested resulted in improved healing, the 6mg/kg dose resulted in accelerated bone healing and a significant increase in mineralized callus volume (p<0.05). Similarly, while all doses of MAK123 reduced evoked responses to tactile stimulus as demonstrated by increased paw withdrawal thresholds, 6 mg/kg of MAK123 resulted in a more robust and significant improvement (p<0.05). We postulate that optimization of the dosing schedule/concentration could further improve both bone healing and behavioral measures thought to represent pain in rodents. That said, these promising pre-clinical data warrant further evaluation as MAK123 may prove to be a unique tool for orthopaedic surgery usage whereby it could both improve bone healing and reduce clinical pain, improving overall patient outcomes.

Why Should I Take My Medicine? A Review Of ED Visits For Seizures.

Study hypothesis The costs of anti-epileptic medication (AED) and poor care coordination result in increased Emergency Department (ED) visits for seizure events and produce both direct and indirect economic burdens on patients with frequent seizures. Methods A retrospective chart review study of ED visits with chief concern of seizure from two hospitals over a two-year period was performed; resulting in 152 visits recorded in this study. Data collected included demographic information, relevant seizure or past medical history (PMH), diagnostics performed in the ED, and the admission status of the patient along with the total charges per encounter. Data was analyzed descriptively and with logistic regression analysis. Results The results yielded by this study were generally in-line with the results of similar studies, indicating a higher relative rate of ED seizure visits for males, people of Black race, and infant and toddler populations. A high proportion of Medicaid/Medicare coverage and indiscernible employment status for most patients were also noted. Observed differences in average cost among patients with and without epilepsy and male versus female patients were not shown to be statistically significant. However, the increased likelihood of admission with increasing age was shown to be significant with an average age difference between admitted and discharged populations of approximately 10 years (p= 0.003). Conclusions The data provided here is not sufficient to examine the complex relationship between seizures, epilepsy, and costs among various other patient factors. Further study is necessary to minimize direct and indirect costs of seizures. Acknowledgments This project was funded, in part, with support from the Indiana Clinical and Translational Sciences Institute funded, in part by UL1TR002529 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Are age-related biomarkers of dementia risk accelerated by low educational attainment?

Background: Low education significantly elevates dementia risk but it is not clear whether this is through chronic systemic inflammation, early-onset dementia pathology, or other factors. This project compares biomarkers of inflammation and dementia pathology in a young-old and older cohort. Due to significantly lower education in the young-old cohort, we hypothesized evidence of similar or higher biomarker levels in the young-old cohort compared to the older cohort. Methods: Blood samples were used to measure pro-inflammatory cytokines (C-reactive protein (CRP), tumor necrosis factor (TNF interleukin (IL)-6, and IL-1 anti-inflammatory cytokines (IL-10 and IL-1RA), and the brain biomarkers phosphorylated tau (p-tau) and neurofilament light (NfL). Inflammatory markers were measured at the Considine Lab at the Indiana University School of Medicine using ELISA assays while p-tau and NfL were measured with Simoa assays at the Quanterix lab in Massachusetts. We used the natural logarithm of all biomarker variables to address skewed data. Linear regression was used to investigate race- and gender-adjusted differences in the biomarkers. Results: The young-old cohort (N=42) has a mean age of 62.4, 69.1% are female, and 78.6% are non-Hispanic black (NHB), while the older cohort (N=60) has a mean age of 80.3, 60% are female, and 20% are NHB. Median education in the young-old cohort is 12 vs 16 in the older cohort. Adjusted models showed higher mean CRP (p=0.004) and lower mean IL-10 (p<0.001) in the young-old cohort. TNF- (p <0.001), IL-6 (p=0.021), and IL-1(p=0.017), P-tau (p=0.003), and NfL (p<0.001) were all higher in the older cohort. Conclusion: We found partial support of our hypothesis in that the younger, low education cohort had higher mean CRP and lower mean IL-10 (anti-inflammatory). However, brain biomarkers were higher in the older cohort. More research will be needed to determine if and how low education elevates ADRD risk through systemic inflammation.

AEBP1 is Upregulated in Diabetic Nephropathy Biopsies

Background: Worldwide, one in eleven adults have diabetes mellitus and 30% to 40% will develop diabetic kidney disease (DKD). A mechanistic understanding of DKD is crucial to develop treatment strategies. To unravel DKD’s pathogenesis, single cell (scRNA) sequencing has proven a powerful tool, but is limited by a lack of localization. Spatial transcriptomics allows the mapping of scRNA sequencing data back to histology. Methods: Frozen human nephrectomy and biopsy samples were processed according to Visium spatial gene expression protocols, stained with H&E, and imaged. Samples were permeabilized for RNA capture, reverse transcribed and sequenced on an Illumina NovaSeq 6000. Mapping and counting were completed in Space Ranger and data was processed in Seurat. Samples were laser microdissected, protein was isolated, and protein was quantified by HPLC-MS. Results: Clusters from scRNAseq were mapped upon reference and DKD spatial transcriptomic images (N=4 reference, 2 DKD). Differentially expressed genes were identified in diabetic kidneys, including the upregulation of Adipocyte Enhancer Binding Protein (AEBP1). Pathway analysis revealed enrichment of extracellular matrix organization and immune process pathways. To increase the confidence of these findings, glomeruli and the tubulointerstitium were laser microdissected (N=7 diseased, 4 reference) for proteomic analysis. AEBP1 was upregulated in the tubular interstitium of diseased kidneys and selectively upregulated in the glomeruli of Diabetic Nephropathy samples (N=2). AEBP1 localized to the interstitium by spatial transcriptomics and was expressed in highly fibrotic regions. Glomerular expression was not observed due to glomerulosclerosis. Conclusion: AEBP1 upregulation is a marker of interstitial fibrosis, with specific expression in the glomeruli of diabetic nephropathy specimens with glomerulosclerosis. Impact: This is the first study utilizing spatial transcriptomics to define and localize markers of human kidney disease. Confirmatory studies are required in larger sample sizes. AEBP1 is a previously unidentified marker of DKD previously associated with fibrosis in other organ-specific diseases.

SIRT1 Inhibition Impairs Ca2+ Buffering in Coronary Smooth Muscle Cells of Ossabaw Miniature Swine

Background: SIRT1 is a deacetylase that has diverse roles in intracellular Ca2+ signaling, metabolism, and cardiovascular disease. SIRT1 increases sarco-endoplasmic reticulum Ca2+ ATPase (SERCA) activity that is essential to buffer the increase in Ca2+ induced by release from the sarcoplasmic reticulum (SR). Our lab has shown that metabolic syndrome (MetS) impairs SERCA activity in coronary smooth muscle cells and causes coronary artery disease in Ossabaw miniature swine. We hypothesized that SIRT1 inhibition and MetS would impair Ca2+ buffering. Methods: CRISPR/Cas9 methods delivered a leucine to proline point mutation in SIRT1 (SIRT1L100P) into the Ossabaw swine genome to compare to wild type (WT) and mimic the naturally occurring mutation in humans and decrease SIRT1 activity. Four treatment groups of juvenile swine were based on genotype and diet: WT Lean, SIRT1 Lean, WT MetS, and SIRT1 MetS. Lean swine were fed normal chow and MetS were fed a hypercaloric, atherogenic diet for 7 months. The left anterior descending coronary artery was harvested and enzymatically digested to obtain cells. Fluorescence microscopy measured the Ca2+ indicator fura-2 in single cells. The cells were exposed to 5 mM caffeine to maximally release stores of Ca2+ from the SR. Ca2+ buffering capacity of each cell was analyzed after the caffeine-induced peak increase to assess Ca2+ efflux and SERCA activity. Results: MetS was confirmed by increased body weight, impaired glucose tolerance, hyperinsulinemia, and hypercholesterolemia. Coronary atherosclerosis was shown by angiography, intravascular ultrasound, and gross imaging. The rapid phase of Ca2+ buffering due to Ca2+ efflux was not affected by SIRT1 mutation or MetS. The slower phase of Ca2+ buffering due to SERCA activity was impaired only by SIRT1 mutation (p<0.0005), not by MetS. Conclusion: SIRT1 mutation alone inhibited SERCA buffering of Ca2+ in coronary smooth muscle. (Support: NIH T35HL110854, DK120240, DK09751.)

Fabrication of an Electrically Conductive Adhesive for Skin Mounted Bioelectronic Devices

Background: Skin mounted bioelectronics are difficult to integrate with the skin since biocompatible adhesives are not conductive or unsuitable for long-term use. Skin conformability is essential but strong adhesives can damage soft tissue in younger and frail individuals as well as the device during removal. Developing a noninvasive long-lasting biocompatible conductive adhesive for skin that can be used with bioelectronics allows for better treatment options and the improvement of patient outcomes. Methods: This study creates a soft hydrogel using graphene oxide flakes (GO) and polyvinyl alcohol. Networked GO is reduced in a solution of sodium dithionite and sodium hydroxide to form a conductive network within the hydrogel. Adhesive properties are achieved by incorporating a polyacrylic acid polymer into the hydrogel with the addition of N-hydroxysulfosuccinimide (NHS) groups to the polymer. NHS reacts with amine groups found on tissue to form covalent bonds that can be released with a biocompatible trigger solution of sodium bicarbonate and glutathione. Results: Hydration of the hydrogel at 65°C demonstrated that the hydrogel swelled anistropically with swelling ratios of 1.05/1.06/5.5 (length/width/thickness). This showed that the hydrogel can integrate into various surfaces without deformation. The hydrogel demonstrated an impedance of 106.1~164.6 Ω⋅m (20~500 Hz), which is comparable to conventional devices. The hydrogel was chemically bound to amine functionalized polydimethylsiloxane (PDMS) and glass. Peel test showed peak adhesion forces of 100.5 N⋅m-1(Force⋅Width-1) when bound to PDMS or glass. Signal quality of the hydrogel showed that the hydrogels demonstrated ECG and EMG signals comparable to commercially available materials. Conclusions: The importance of this study is to create a soft material that bonds between electrodes and skin. The results demonstrate that the hydrogel has electrical characteristics comparable to conventional electrodes for use in ECG and EMG. In addition, it can create adhesion via chemical bonds that can be released on demand.

Relationship between dementia severity in older women and family caregivers’ preferences for shared decision making about breast cancer screening

Background/Objective: Mammography is one of the most effective ways to diagnose breast cancer early; however, its perceived benefits are complicated by terminal conditions such as dementia. By undergoing mammography, women with dementia risk treatment complications and false-positive results, which can exacerbate psychological distress. The lack of a standard of care confounds the individual roles of the patient, family caregiver, and physician in the decision-making process. This study evaluates the relationship between dementia severity and family caregiver preferences for shared decision making. Methods: Data were gathered from the Decisions about Cancer screening in Alzheimer’s Disease trial, which uses the Dementia Severity Rating Scale (DSRS) and a revised version of the Control Preferences Scale (CPS) to assess family caregiver preferences for decision-making as a dyad (patient and caregiver) and triad (patient, caregiver, and physician). Two multinomial logistic regression models assessed the relationship between DSRS and CPS categories (active, passive, and collaborative), while controlling for the caregivers’ age, gender, education, relationship to patient, self-perceived income, and race. Both models used the “active” group as the baseline; however, Model 1 examined preferences as a dyad and Model 2 as a triad. Results: Model 1 found a statistically significant association between dementia severity and a collaborative approach (p<0.001), and between dementia severity and a passive approach (p=0.014). For every one-unit increase in DSRS score, the odds of being in the collaborative group decreased by 0.083 and the odds of being in the passive group decreased by 0.085. There was no statistically significant association between dementia severity and decision-making preferences in Model 2. Clinical Significance: The association between dementia severity and family caregiver decision-making preferences supports the need for a standard of care regarding breast cancer screening in women with dementia.

Instability in Patients with Lumbar Spine Disease or Fusion Undergoing Posterior Approach vs. Lateral Approach Primary Total Hip Arthroplasty

Background and Hypothesis: Dislocation rates after total hip arthroplasty (THA) in patients with fixed spinopelvic motion due to lumbar spine disease or fusion have been reported as high as 20%. Few studies exist that compare dislocation rates in patients with spine pathology undergoing THA via different surgical approaches. The purpose of this study was to compare postoperative dislocation rates in patients with lumbar spine disease or fusion between those undergoing a primary THA using a posterior versus direct lateral surgical approach. Experimental Design or Project Methods: With IRB approval, 1,205 primary THAs performed by two surgeons were retrospectively reviewed. One surgeon routinely performs THAs with a posterior approach while the other surgeon routinely uses a direct lateral approach. Chart review from the electronic medical record was conducted to identify patients who have lumbar spine disease or a lumbar spine fusion. Dislocations for patients with and without lumbar spine disease were compared by posterior approach and direct lateral approach. Results: 767 posterior approach and 431 direct lateral approach THAs were available for analysis. 43.6% of all THAs had lumbar spine pathology (337/767 posterior and 185/431 direct lateral). The overall dislocation rate was 1.26% (15/1195). The main predictors of dislocation in binary logistic regression were the presence of lumbar spine pathology (OR 5.24, 95% CI: 1.47–18.69, p=0.018) and posterior surgical approach (OR 7.93, 95% CI: 1.04–60.6, p=0.046). The dislocation rate for direct lateral approach THAs with lumbar spine pathology was significantly lower compared to posterior approach THAs with lumbar spine pathology (0.0% vs 3.6%, p=0.011). Conclusion and Potential Impact: Although there were few dislocations, the study results suggest a direct lateral approach for primary THA may be beneficial to reduce postoperative dislocation for patients with limited spinopelvic motion due to lumbar spine pathology.